Reduction In Tumor Size Research Articles

Abstract 4538: Brigatinib induces synergy with PARP inhibitors through dual inhibition of FAK and EphA2 in high-grade serous ovarian carcinoma

Abstract PARP inhibitors (PARPis) have now become a standard of care for high-grade serous ovarian cancer (HGSOC), especially for those with defects in homologous recombination (HR) DNA repair. However, the innate and acquired PARPi resistance in HGSOC poses a significant concern, necessitating the exploration of novel treatment options and strategies. Here we investigated the potential of combining brigatinib—a second-generation anaplastic lymphoma kinase (ALK) inhibitor approved for treating lung cancer—with PARPis as way to enhance PARPi activity in HGSOC. Clonogenic cell survival assays revealed that brigatinib synergizes with PARPis in HR-proficient and -deficient HGSOC cell lines. In subsequent proteomics approaches and cell-based confirmatory studies, we found that brigatnib suppressed tyrosine kinases FAK and EphA2 with reduction in downstream signaling. Follow-up pharmacologic and gene-silencing techniques demonstrated that dual FAK and EphA2 inhibition additively reduces PI3K/Akt and MAPK/ERK cell survival signaling to levels conferring PARPi sensitivity. Additionally, the efficacy of this therapeutic approach on tumor size reduction was assessed in HGSOC patient-derived xenograft (PDX) models, with combination treatment inducing tumor regression more effectively than either agent alone. Overall, our studies unveil a beneficial ALK-independent effect of brigatinib that may offer new avenues for considering its repurposing as a HGSOC therapy. Citation Format: Julie R. Duffield, Xiaonan Hou, Iman K. McKeon-Makki, Amelia M. Huehls, Benjamin W. Wilson, Anjali Prasad, Xinyan Wu, Scott H. Kaufmann, Larry M. Karnitz, John J. Weroha, Arun Kanakkanthara. Brigatinib induces synergy with PARP inhibitors through dual inhibition of FAK and EphA2 in high-grade serous ovarian carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4538.

Abstract 5786: Epstein-Barr virus nuclear antigen 1 (EBNA1)-targeting probes stimulate interferon-β production by nasopharyngeal carcinoma (NPC) cells to enhance the natural killer cell-mediated cytotoxicity against NPC

Abstract Introduction: The prevailing histologic subtype of nasopharyngeal carcinoma (NPC) in the endemic regions is non-keratinizing carcinoma which shows almost consistent association with latent infection by Epstein-Barr virus (EBV). Previously our group developed a series of Epstein-Barr virus nuclear antigen 1 (EBNA1)-targeting probes, which can disrupt the EBV latency maintained by EBNA1, and such lytic induction could alert the immune cells. Methods: Natural killer (NK) cells of the innate immunity play a significant role in controlling EBV infection. In this study, we investigated whether our EBNA1 probes (ZRL5P4 & L2P4) could activate NK cells to eliminate NPC. Results: Studies of clinical specimens indicated that tumor infiltration of the cytotoxic NK cell subset is a favorable prognostic marker for NPC patients. Furthermore, the cytotoxicity of circulating NK cells derived from NPC patients is equally well the cells from healthy individuals. If those patients’ NK cells can be attracted to infiltrate into the tumors, the tumor burden should be relieved. Indeed, the NPC xenograft with the ZRL5P4 treatment showed heavy mouse NK cell infiltration and tumor size reduction. The essential role of those mouse NK cells was demonstrated. Next, we showed that ZRL5P4 could induce the production of a soluble factor by NPC cells to stimulate the NK cell cytotoxicity. Such NK cell activity was verified in a metastasis NPC model. Mechanistically, the EBNA1 probe treatment could induce the expression of EBV early lytic gene Rta and EBNA1 itself. Both Rta and EBNA1 are known transcription factors to drive the expression of LMP1, the NF-κB signaling was then activated, which turned on the production of the well-known NK cell activation cytokine IFN-β. Conclusion: Taken together, our results demonstrated that our EBNA1 probes can mobilize NK cells to the tumor sites and activate their anti-tumor activity via the EBV reactivation and stimulation of IFN-β production. Citation Format: Luo Chen, Xiao Han Liu, Hei Tung Yuen, William C. Cho, Ka-Leung Wong, Hong Lok Lung. Epstein-Barr virus nuclear antigen 1 (EBNA1)-targeting probes stimulate interferon-β production by nasopharyngeal carcinoma (NPC) cells to enhance the natural killer cell-mediated cytotoxicity against NPC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5786.

Abstract 6360: A novel CAR-NK cell therapy to target lung adenocarcinoma cells

Abstract Cell Adhesion Molecule (CADM1) is a Bonafede tumor suppressor with 40% of NSCLC tumors lose CADM1 expression either by loss of heterozygosity or promoter hypermethylation. The tumor suppressive ability of CADM1 is attributed to its cell adhesion function. However, we previously demonstrated that CADM1 also mediates its tumor suppression through regulation of NK-mediated immunosurveillance. In tumors that do not lose CADM1, it is expressed on cell surface and up regulated during TGF-β-induced EMT making it a biomarker for potential therapeutic targeting. Here we report the design and development of T and NK specific CAR that would specifically target lung cancer cells in CADM1 dependent manner. Anti-CADM1 single chain variable fragment (CADM1-scFv) was fused to NK or T cell specific transmembrane and co-stimulatory domains. The resulting CAR constructs were cloned into a retroviral vector, from which viral stocks were generated to transduce human and mouse cells. Next, we introduced anti-CADM1-CAR-NK construct into NK92 cell line and tested it in a cytotoxicity assay using A549-GFP-ffluc cell line as a target. We observed a significant increase in the killing of target cells with anti-CADM1-CAR-NK cells compared with non-transduced NK92 cells. This effect was significantly reduced when A549- GFP-ffluc-CADM1 KO cells were used as target. Next, we generated anti-CADM1-CAR-T cells by transducing human CD3+ T-cells purified from human PBMCs. Similar to anti -CADM1-CAR-NK, anti-CADM1-CAR-T cells showed increased T-cell specific cytotoxicity in a CADM1-dependent manner. Next, we evaluated the efficacy of anti-CADM1-CAR-T cells through adoptive transfer into NSG mice xenografted with human lung adenocarcinoma cells into mouse lungs. The administration of anti-CADM1-CAR-T cells markedly reduced tumor size and enhanced the survival rate of the mice. Importantly this effect was dependent on CADM1 expression, as mice xenografted with human CADM1 KO cells showed neither tumor size reduction nor increased survival. Finally, using IHC staining, we demonstrated that anti-CADM1-CAR-T cells directly target xenografted tumors in the mouse lungs. In conclusion, our findings indicate that CAR-NK and CAR-T cells targeting CADM1-expressing lung tumors have a significant therapeutic potential for the treatment of NSCLC. Citation Format: Sergey Zolov, Sergei Chuikov, Shiva Krishna Katkam, Delaney Shield, Venkateshwar G. Keshamouni. A novel CAR-NK cell therapy to target lung adenocarcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6360.

Abstract 3860: Characterizing peripheral immune correlates of tumor response in breast cancer patients immunized with the P10s-PADRE vaccine

Abstract Introduction: We demonstrated that vaccination of HR+/HER2− breast cancer subjects with P10s-PADRE cancer vaccine in combination with standard-of-care chemotherapy led to generation of antibodies (Ab), activation of Natural Killer (NK) and T cells, increases in IFNγ and TNFα, and increases in TILs and stromal CD3+ T cells. The current study was conducted to assess the vaccine's efficacy, particularly focusing on tumor shrinkage and pathologic Complete Response (pCR). Additionally, it aims to explore the association of specific peripheral-blood immune responses, such as antibody levels and NK and T-cell activation, with pCR and objective reduction in primary tumor size. Methods: Blood samples collected at baseline and after treatment of at least 25 subjects were used in characterization of immune responses. Serum and plasma samples were used in ELISA, cytokine, and glycan-array assays to measure anti-peptide and anti-glycan antibodies and blood-cytokine levels. Peripheral blood mononuclear cells (PBMCs) were interrogated by RNA-seq, flow cytometry, and ELISpot assays. Results: We observed that high levels of anti-peptide and anti-GD2 antibody responses correlated with pCR. Ab response was positively correlated with differential expression of CD56, GZMA, IFNγ, NKp46, and CD8b, among which GZMA and NKp46 showed a statistically significant association. Vaccine-induced functional cellular immune responses (measured by differential expression of IFNγ, GZMA, CD8, CD69, NKp46, CD56, and PRF1) correlated with reduction of primary tumor size. We also observed substantial differences among immune responders vs non-responders in immune gene expression and in cytokine production in post-immune PBMCs after specific and polyclonal stimulation. Conclusions: The data suggest that immunization of HR+/HER2− breast cancer patients with P10s-PADRE in combination with chemotherapy leads to both humoral and cellular immune responses. While induction of a robust antibody response is a good marker for potential clinical efficacy, vaccine-associated increases of the ratio of CD8+ cells and the expression of CD69, CD8b, GZMA, IFNγ, NKp46, and PRF1 seem to serve as additional efficacy indicators. Future studies are underway to validate these findings and establish reliable prognostic biomarkers. Citation Format: Fariba Jousheghany, John P. Lee, Bernice Nounamo, Vinay Raj, Jennifer L. Faulkner, Eric Siegel, Issam Makhoul, Thomas Kieber-Emmons, Behjatolah Monzavi-Karbassi. Characterizing peripheral immune correlates of tumor response in breast cancer patients immunized with the P10s-PADRE vaccine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3860.

Abstract 4126: The inhibitory effect of statins on distant metastasis and recurrence of endometrial cancer

Abstract Endometrial cancer (EC) is the most common gynecologic malignancy. The most common histological type is endometrioid endometrial cancer (EEC). While the majority of patients present with early-stage and low-grade EEC and have an excellent prognosis, a subset develops distant recurrence derived from EEC after initial treatment of the primary. However, the exact mechanism of distant metastasis and recurrence from EEC is still unclear. In addition, the lack of suitable pre-clinical models is a significant barrier to research for distant metastasis and recurrent cancer derived from EEC. Our preclinical EEC model, the ablation of both Mig-6 and Pten in the uterus (Pgrcre/+Mig-6f/fPtenf/f; Mig-6d/dPtend/d), dramatically accelerates the development of EEC compared to single ablation of either gene. The ablation of both Mig-6 and Pten in the uterus (Pgrcre/+Mig-6f/f Ptenf/f; Mig-6d/dPtend/d mice) displayed distant metastases into the ovary, diaphragmatic skeletal muscle, lymph node, and lung. However, the Ptend/d mice exhibited endometrial cancer without distant metastases. After hysterectomy of EEC confined to uterus, Mig-6d/dPtend/d mice exhibited recurrent EEC in abdomen and lung. To identify prognostic factors for distant metastatic and recurrent EEC, we performed transcriptomic analysis in endometrial hyperplasia, a precancerous condition, from Ptend/d and Mig-6d/dPtend/d mice. Our transcriptomic analysis identified that cholesterol biosynthesis was the most significantly activated pathway in Mig-6d/dPtend/d mice compared to Ptend/d mice. Statins, also known as HMG-CoA reductase inhibitors, are the most common cholesterol-lowering drugs. We evaluated the effect of atorvastatin on tumorigenesis and recurrence of EEC. Mig-6d/dPtend/d mice treated with atorvastatin displayed significant reduction of tumor size compared to vehicle treated group. For vehicle-treated group, our pathological analysis revealed EEC outside the uterus, therefore EEC had disseminated to involve the ovary, diaphragmatic skeletal muscle, lymph node, and lung. However, EEC was confined to the uterus in the atorvastatin treated group. Furthermore, atorvastatin treatment reduced the rate of recurrent EEC development. This data demonstrated that atorvastatin has a remarkable inhibitory effect on metastasis and recurrence of EEC in Mig-6d/d Ptend/d mice. Our results suggest that statins suppress development of distant metastasis and recurrence in mouse models of EEC with Pten and Mig-6 deficiency by inhibiting cholesterol biosynthesis. Citation Format: Keun Cheon Kim, Jung Yoon Yoo, Russell R Broaddus, Eunhee M Jeong, Mark I Hunter, Tae Hoon Kim, Jae-Wook Jeong. The inhibitory effect of statins on distant metastasis and recurrence of endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4126.

Abstract 7207: Targeting hippo signaling pathway to overcome chemoresistance in glioblastoma

Abstract The study aims to investigate whether the Hippo signaling pathway contributes to temozolomide chemoresistance in glioblastoma, and to validate whether the combinational treatment of temozolomide and YAP inhibitor is effective against glioblastoma. Temozolomide-sensitive and temozolomide-resistant U87 and U251 GBM human cell lines were previously established. Temozolomide-resistant cells were maintained in low-dose temozolomide. Here, we investigate whether Hippo signaling contributes to temozolomide chemoresistance. By modulating the Hippo signaling pathway through YAP gene knockdown, the outcome on cell proliferation was studied by cell viability assay (in vitro) and mouse orthotopic xenograft (in vivo). Finally, the therapeutic effect of YAP inhibitor is studied in vitro and in vivo respectively. Our data showed that YAP is overexpressed in temozolomide-resistant glioblastoma cells. Nuclear translocation of YAP (which becomes its active state) is increased in temozolomide-resistant cells. In fact, YAP inhibition show decreased cell viability and higher susceptibility to temozolomide. In addition, mice with tumor injection of the YAP knockdown cells reduced tumor size with temozolomide treatment. Similarly, YAP inhibitor resensitizes temozolomide-resistant cells to temozolomide. Combinational treatment of YAP inhibitor and temozolomide is effective in shrinking tumor size in mouse xenograft models. In conclusion, our data suggest dysregulated Hippo signaling pathway contributes to temozolomide chemoresistance, thus targeting the Hippo signaling pathway resensitizes GBM cells to temozolomide. This research provides pre-clinical evidence on using YAP inhibitor for combinational therapy with temozolomide for the treatment of glioblastoma. Citation Format: Cheuk Lun Ethan Wong, Mei Yee Karrie Kiang, Ka Kit Gilberto Leung. Targeting hippo signaling pathway to overcome chemoresistance in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7207.

Abstract 4747: Novel targets for BRAFV600E and BRAFV600ERAC1P29S drug resistant melanoma

Abstract The most common mutational drivers in malignant melanoma are the oncogene BRAFV600E/K (60%), NRASQ61L/R (30%) and the RHO GTPase RAC1P29S/L (9%). BRAFV600E/K melanoma standard of care comprises the use of checkpoint inhibitors (CPIs) such as anti-PD1 or anti-CTLA-4 in combination with targeted therapies against BRAF and MEK kinases. BRAF mutant melanomas develop intrinsic, acquired, or after treatment resistance to BRAF and MEK inhibitors : around half of targeted therapy combination treatments with anti-PD1 and 70% with anti-CTLA-4 will be unsuccessful due to melanoma intrinsic resistance. Among other causes, intrinsic drug resistance can be associated with additional genome mutations, such as the activating Rac1P29S mutation present in 6% of patients with BRAF positive melanoma. A deeper understanding on the biology, progression, and tumor microenvironment of drug resistant melanomas is needed to aid in the search of novel targets and to increase the effectivity of proposed treatments. We generated 3 sets of isogenic BRAFV600E and BRAFV600E/RAC1P29S cell lines by transfecting 501mel, 451Lu and YUMM1.7 cell lines with Rac1P29S. We then exposed them for 3 months to increasing concentrations of PLX4720 to generate drug resistant cell lines (DR). Rac1 P29S -transfected and PLX4720 resistant cell lines had an increase in the Mek/Erk signaling pathway. A differential analysis using a kinome and an epigenome drug screening library in the 501mel cell lines (501mel, 501mel Rac1P29S, 501mel-DR, 501mel Rac1P29S -DR) showed that BRAFV600E/RAC1P29S and the DR melanoma cell lines growth can be inhibited with mTor, PI3K, cdk9 and BRD4 inhibitors. BRD4 is an epigenetic regulator that recruits P-TEFb to stimulate RNA polymerase II elongation. BRD4 also interacts with SMAD3 and CDK9 to regulate transcription through eIF4G increasing oncogenic c-Myc and increasing Mek/Erk signaling pathways. We tested 501mel, 451Lu and YUMM1.7 isogenic cell line series against Rapamycin to confirm mTORC1 as an effective target. Drugs that target different subunits of the eIF4F complex (CR-1-31-B, Ribavirin and Briciclib) also decrease BRAFV600E/RAC1P29S and the DR melanoma cell lines growth specifically. Furthermore, silencing of eIF4A1 and Raptor genes reduces cell growth in the BRAFV600E/RAC1P29S, and the DR cells when compared to the parental cell lines. Silencing Rictor had no effect on cell growth on any cells. When tested in a syngraft model, CR-1-31-B and rapamycin reduced tumor size when using YUMM1.7, YUMM1.7- RAC1P29S and YUMM1.7 RAC1P29S-DR cell lines. Next, we sought to investigate the effect of inhibiting mTOR and eiF4F in the PD-1/PD-L1 axis in tumor cells and tumor associated dendritic cells and macrophages, and how targeting these modifies the tumor microenvironment. Citation Format: Cristina Uribe-Alvarez, Daniela Araiza-Olivera, Alexa Cannon, Jonathan Chernoff. Novel targets for BRAFV600E and BRAFV600ERAC1P29S drug resistant melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4747.

Abstract 4318: CD24 enhances cisplatin resistance in ovarian cancer by suppressing autophagy

Abstract Ovarian cancer is one of the most common gynecological cancers with the highest mortality rate. Most patients are diagnosed with advanced disease and will relapse due to chemoresistance. CD24, a highly glycosylated GPI-anchored membrane protein. Recent studies have shown that CD24 expression is significantly up-regulated in ovarian cancer and is associated with chemotherapy resistance, and CD24 also plays an inhibitory role in tumor immunity by binding to Siglec-10 on macrophages. However, the molecular mechanisms of how CD24 affects chemotherapy resistance in ovarian cancer remain unclear. In this study, we used shRNAs to knockdown CD24 and explore the impact and mechanism of CD24 on the chemotherapy resistance of ovarian cancer cells. The results showed that knockdown of CD24 in ovarian cancer cells SKOV3 and TOV21G significantly reduced cell proliferation and arrested the cell cycle in S phase. Knockdown of CD24 also significantly increased the sensitivity of ovarian cancer cells to cisplatin but had no effect on paclitaxol treatment. Further experiments showed that knockdown of CD24 increased cisplatin sensitivity by promoting autophagy-induced cell death. In addition, Gene Set Enrichment Analysis (GSEA) was used to analyze the correlation between the expression of CD24 and its biological functions in the TCGA ovarian cancer dataset. The results showed that CD24 is mostly correlated to cell proliferation and autophagy-related pathways in ovarian cancers. Further mouse xenograft tumor transplantation experiments also confirmed that knockdown of CD24 reduced tumor size and increased sensitivity to cisplatin treatment by increasing cell autophagy. Taken together, these results indicate that CD24 regulates cell growth and chemoresistance in ovarian cancer cells and that inhibition of CD24 may be helpful in the treatment of ovarian cancer. Citation Format: Yuh-Ling Chen, Tse-Ming Hong, Yu-Yi Wen. CD24 enhances cisplatin resistance in ovarian cancer by suppressing autophagy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4318.

Impact of RRP1B Variants on the Phenotype, Progression, and Metastasis of Cervical Cancer.

Metastasis is a key determinant of cancer progression, influenced significantly by genetic mechanisms. RRP1B, primarily a nucleolar protein, emerges as a suppressor of metastasis, forming alliances with various cellular components and modulating gene expression. This study investigates the involvement of the ribosomal RNA processing 1 homolog B (RRP1B) gene in metastasis regulation in cervical cancer. Through a comprehensive analysis of 172 cervical cancer patients, we evaluated five RRP1B single nucleotide polymorphisms (SNPs) (rs2838342, rs7276633, rs2051407, rs9306160, and rs762400) for their associations with clinicopathological features and survival outcomes. Significant associations were observed between specific genetic variants and clinicopathological parameters. Notably, the A allele of rs2838342 was associated with reduced odds of advanced tumor size, worse prognosis, and, preliminarily, distant metastasis, while the T allele of rs7276633 correlated with a decreased risk of higher tumor size and worse prognosis. Additionally, the C allele of rs2051407 demonstrated protective effects against larger tumors, metastasis, and adverse prognosis. The rs9306160 C allele exhibited a protective effect against metastasis. The rs762400 G allele was significant for reduced tumor size and metastasis risk. Furthermore, the rs2838342 A allele, rs7276633 T allele, rs2051407 C allele, and rs762400 G allele were associated with improved overall survival, demonstrating their potential significance in predicting prognoses in cervical cancer. Linkage disequilibrium and haplotypes analysis enabled us to evaluate the collective effect of the analyzed SNPs, which was in line with the results of allelic models. Our findings underscore the clinical relevance of RRP1B SNPs as prognostic markers in cervical cancer, shedding light on the intricate interplay between genetic factors and disease-progression dynamics. This research provides critical insights for future investigations and underscores the importance of incorporating RRP1B SNP detection into prognostic-assessment tools for accurate prediction of disease outcomes in cervical cancer.

Abstract 4028: Inhibition of IL25 IL17RA improves immune related adverse events of checkpoint inhibitors and reveals antitumor activity

Abstract Immune checkpoint inhibitors (ICI) have improved outcomes and extended patient survival in several tumor types. However, ICI often induces immune-related adverse events (irAEs) that warrant therapy cessation, thereby limiting the overall effectiveness of this class of therapeutic agents. Currently, available therapies used to treat irAEs might also blunt the antitumor activity of the ICI themselves. Therefore, there is an urgent need to identify treatments that have the potential to be administered alongside ICI to optimize their use. Using a translationally relevant murine model of anti-PD-1 and anti-CTLA-4 antibodies-induced irAEs, we compared the safety and efficacy of prednisolone, anti-IL-6, anti-TNFɑ, anti-IL-25 (IL-17E), and anti-IL-17RA (the receptor for IL-25) administration to prevent irAEs and to reduce tumor size. While all interventions were adequate to inhibit the onset of irAEs pneumonitis and hepatitis, treatment with anti-IL-25 or anti-IL-17RA antibodies also exerted significant additional antitumor activity. Mechanistically, IL-25/IL-17RA blockade reduced the number of organ-infiltrating lymphocytes. These findings suggest that IL-25/IL-17RA may serve as an additional target when treating ICI-responsive tumors, allowing for better tumor control while suppressing immune-related toxicities. Citation Format: Xizi Hu, Shoiab Bukhari, Carly Tymm, Kieran Adam, Shalom Lerrer, Brian Henick, Robert Winchester, Adam Mor. Inhibition of IL25 IL17RA improves immune related adverse events of checkpoint inhibitors and reveals antitumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4028.

Abstract 3281: Silencing of necroptosis related genes in endocrine-resistant breast cancer cells causes PFKFB3 induced arrest of necroptosis and contributes to resistance

Abstract Approximately 70% of newly diagnosed breast cancer patients are estrogen receptor positive. Patients treated with approved treatment strategies may develop resistance to these therapies. Because of this problem in treatment, new treatment regimens need to emerge. Altered reprogramming of metabolism and an intense dependence on glycolysis are hallmarks of cancer, which is necessary to support the high energy demand of rapidly proliferating cancer cells. Rapidly dividing cancer cells are known to have increased energy requirements and altered reprogramming of glucose metabolism, leading to an increased reliance on glycolysis. The conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, a critical rate-limiting step in the glycolysis pathway, is greatly influenced by an allosteric activator produced by the enzyme PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3), thus making PFKFB3 an important regulator of glycolytic flux. Furthermore, PFKFB3 has been shown to be overexpressed in many human cancers, including breast cancer, and upregulated by estrogen. In our previous studies, we have shown that endocrine-resistant BC cells growth is strongly reduced by PFKFB3 targeting using PFKFB3 inhibitors, glucose uptake is reduced, triggered to necroptosis by RIPK1 and MLKL phosphorylation, and PFKFB3 inhibition reduces tumor size in mouse xenografts. In this study, we showed that silencing of RIPK1 and MLKL, genes involved in necroptosis, by siRNAs followed by inhibition of PFKFB3 by PFK158 did not induce necroptosis in endocrine-resistant BC cells. Furthermore, we further confirmed that phosphorylation of MLKL and RIPK occurs with PFKFB3 inhibition. In summary, this study reveals that necroptosis induced by PFKFB3 inhibition contributes to resistance by arresting necroptosis in endocrine-resistant BC cells after silencing of necroptosis-related genes. Citation Format: Brandon C. Jones, Tuna Onal, Surojeet Sengupta, Catherine M. Sevigny, Lu Jin, Paula R. Pohlmann, Ayesha Shajahan-Haq, Robert Clarke. Silencing of necroptosis related genes in endocrine-resistant breast cancer cells causes PFKFB3 induced arrest of necroptosis and contributes to resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3281.

Abstract 4466: Omega-3 fatty acid-induced ferroptosis in 4T1 breast cancer through CD36/FABP5 axis

Abstract Mammalian cells utilize energy from many different sources, and fatty acids are one of these sources. Dietary fats contain various structures of fatty acids, each impacting cell lipid metabolism in unique ways. Omega-3 fatty acids are known to induce breast cancer cell death through ferroptosis. However, the specific molecular mechanisms by which omega-3 fatty acids trigger ferroptosis have yet to be fully elucidated. Fatty acid binding proteins (FABPs) constitute a family of evolutionarily conserved lipid chaperones, facilitating the transport and utilization of fatty acids within cells. Notably, FABP5 is highly expressed in breast cancer, especially in the most aggressive form, triple-negative breast cancer. We hypothesized that FABP5 acts as a lipid sensor, mediating the ferroptosis induced by omega-3 fatty acids in triple-negative breast cancer cells. To test this, we created Fabp5 stable knockout cell lines in 4T1 and MDA-MB-231, two commonly used triple-negative breast cancer cell lines, using CRISPR/Cas9 technology. When treated with docosapentaenoic acid (DPA), these Fabp5-knockout cells exhibited reduced ferroptosis compared to their wild-type counterparts. Interestingly, blocking the surface protein CD36, either with inhibitors or antibodies, also reduced DPA-induced ferroptosis. Furthermore, mutations in Fabp5 decreased maximal mitochondrial respiration in both 4T1 and MDA-MB-231 cells, suggesting a crucial role for FABP5 in mediating oxygen consumption and reactive oxygen species (ROS) production during DPA-induced ferroptosis. Additionally, mice fed a high-fat diet rich in omega-3 fatty acids showed reduced tumor size and lung metastasis. Collectively, our data indicate that FABP5 is a key molecular sensor mediating oxygen consumption and ROS production, thus contributing to ferroptosis induced by omega-3 fatty acids in triple-negative breast cancer. Citation Format: Anthony Avellino, Jiaqing Hao, Matthew Yorek, Jian yu, Bing Li. Omega-3 fatty acid-induced ferroptosis in 4T1 breast cancer through CD36/FABP5 axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4466.

Abstract 172: Targeting the poliovirus receptor to activate T cells and induce myeloid-derived suppressor cells to differentiate to M1-like macrophages via the IFNγ-pSTAT1-IRF8 axis in cancer therapy

Abstract T cell immunoglobulin and ITIM domain (TIGIT) is one of the most important immune checkpoints expressed on lymphocytes, and poliovirus receptor (PVR, also CD155) serves as the most crucial ligand for TIGIT, harboring an important function in cancer cells and influencing the tumor microenvironment (TME). While it's well-established that TIGIT blockade could reverse immunosuppression, the question of whether direct inhibition of PVR yields comparable results remains to be fully elucidated. In this study, we generated a mouse gene Pvr knock out (KO) Lewis lung cancer (LLC) cell line and found that the Pvr-KO tumors tended to develop a pro-inflammatory TME, as reflected by a downregulation of monocytic-myeloid derived suppressor cells (M-MDSCs) and an upregulation of CD8+ central memory T cells. Through bulk RNA-seq and multi-cytokines measurement, we quantified the transcription and protein levels of immunostimulatory cytokines and chemokines and found they were significantly upregulated in Pvr-KO TME, including GM-CSF, IFN-γ, TNF-α, IL-2/4/6/10, CCLs (including CCL2/3/4/5) and CXCLs (including CXCL1/2/5). We further employed single-cell RNA sequencing (scRNA-seq) on 20,026 intra-tumoral CD45+ immune cells. Using a conserved MDSCs gene set and the 'AddModuleScore' function of Seurat package, we identified the clusters of MDSCs and found the differentiation ability of M-MDSCs in Pvr-KO TME was enhanced. Through pseudo-temporal ordering, we found the M-MDSCs in the Pvr-KO TME have a trend to differentiate towards M1-like macrophages, which could play an essential positive role in anti-tumor immunity. We further focused on the scRNA-seq of T cell subsets and found the enhanced function of cytotoxic CD8+ T cells, leading to increased production of IFN-γ. In the intercellular communications analysis, a significant upregulation of the IFNG-IFNR signal between T cells: MDSCs in the Pvr-KO group was observed. Moreover, we found that Irf8, a key factor in myeloid cell differentiation, was significantly upregulated in the M-MDSCs of Pvr-KO tumor. We then employed CUT & Tag sequencing and confirmed that IFN-γ induces phosphate Stat1, which then binds on the promoter of Irf8. These findings suggest that the IFN-γ-Stat1-Irf8 axis plays a crucial role in MDSCs differentiation and may be a potential target for therapeutic intervention in cancer. Next, an anti-PVR nanobody was synthesized and its efficacy was evaluated in the context of LLC and 4T1 tumor grafts. When in combination with anti-PD-1 therapy, anti-PVR exhibited a remarkable capacity to reduce tumor size in both tumor models with no notable indications of toxicity observed. Our findings provide new insights into the role of PVR in modulating the TME and offer potential strategies for enhancing the effectiveness of immunotherapy. Citation Format: Mingyang Feng, Sirui Tan, Qizhi Ma, Benxia Zhang, Yue Chen, Qiu Li, Yongsheng Wang. Targeting the poliovirus receptor to activate T cells and induce myeloid-derived suppressor cells to differentiate to M1-like macrophages via the IFNγ-pSTAT1-IRF8 axis in cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 172.

Abstract 7180: Tumor growth modeling to support dose justification of Dato-DXd in hormone receptor positive, HER2 negative breast cancer (HR+HER2-BC) subjects

Abstract BACKGROUND: Dato-DXd, a TROP2-directed antibody-drug conjugate, has demonstrated efficacy and a manageable safety profile in multiple tumor types. A dosing regimen of 6 mg/kg every three weeks (Q3W) has been proposed as the optimal schedule based on phase I data in patients with non-small cell lung cancer (NSCLC)1. Dato-DXd demonstrated statistically significant and clinically meaningful improvement in PFS compared with ICC in patients with HR+HER2-BC in TROPION-Breast012. A tumor growth inhibition (TGI) model was developed to support dose justification at 6 mg/kg in HR+HER2-BC subjects. METHODS: A tumor growth inhibition (TGI) model was developed based on tumor size data from HR+HER2-BC patients received 6 mg/kg Dato-DXd Q3W in a Phase I study (N = 39, Data cutoff July 2022). The TGI model described the tumor size as the result of an exponential tumor growth, a tumor shrinkage that was driven by Dato-DXd cycle-specific AUC, and a resistance term suggesting that the shrinkage effect by Dato-DXd decreases over time. Cycle-specific Dato-DXd AUC was derived based on the AUC and time at each cycle for each individual. Simulations were conducted using the TGI model to compare tumor size change from baseline at 4, 6, and 8 mg/kg in HR+HER2-BC patients, with consideration of dropouts. RESULTS: The TGI model well-described tumor size data with reasonable parameter estimations. Simulated time-courses of tumor sizes at Dato-DXd 4, 6, and 8 mg/kg suggested that Dato-DXd at 6 mg/kg may lead to greater tumor shrinkage effect than that at 4 mg/kg in HR+/HER2-BC patients. At approximately 180 days post first treatment, tumor shrinkage at 6 mg/kg was almost 2-times greater than at 4 mg/kg (-51% vs. -25%, respectively). CONCLUSION: Simulations based on the TGI model suggested greater tumor size reduction at Dato-DXd 6 mg/kg compared to 4 mg/kg in HR+HER2-BC patient population. Reference: 1 ACoP13 2022 2 ESMO 2023. Citation Format: Zoey Tang, Yu Jiang, Haitao Yang, David Dai, Chang Gong, Linda Irons, Yuzhuo Pan, Ying Hong, Shuang Liang, Song Ren, Alex Phipps, Diansong Zhou. Tumor growth modeling to support dose justification of Dato-DXd in hormone receptor positive, HER2 negative breast cancer (HR+HER2-BC) subjects [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7180.

Abstract 3600: Reversal of iNKT cell dysfunction in cholangiocarcinoma

Abstract Invariant natural killer T (iNKT) cells are CD1d-restricted unconventional T cells possessing innate and adaptive immunity with high anti-tumor activities. Yet, the effectiveness of iNKT cell therapy in clinical trials is limited due to iNKT cell dysfunction after exposure to the tumor microenvironment. Aggressive cholangiocarcinoma (CCA) cell lines were used to study iNKT cell reactivity. These CCA cell lines lacked CD1d molecules and responded poorly to iNKT cells. The iNKT cells became dysfunctional after the exposure to CCA by 48 h. In this study, we overcame iNKT cell dysfunction by searching for a small molecule to prevent or reverse the gene sets regulating iNKT cell dysfunction, thus prolonging anti-tumor activity. It was found that P53 and estrogen early response pathway gene sets were enriched in dysfunctional iNKT cells which were reversed by vorinostat, an HDAC inhibitor. Anti-CCA activity of iNKT cells was regained with a subtherapeutic dose of vorinostat as protection. Interestingly, vorinostat could not totally recover the anti-tumor effect of iNKT cells that have already developed into the dysfunctional stage. Significant tumor size reduction was seen in the humanized mouse model after iNKT cell adoptive therapy was given in combination with vorinostat compared to monotherapy with either iNKT cell or vorinostat alone. This study demonstrated that inhibiting the gene sets regulating iNKT cell dysfunction by vorinostat could prevent iNKT cell dysfunction, and prolong its anti-tumor activities. This combination could be a novel treatment option for CD1d-negative CCA patients resistant to standard chemotherapy. Citation Format: Khin Su Su Htwe, Kitipong Soontrapa, Siwanon Jirawatnotai, Sunisa Prasopporn, Pimkanya More-Krong, Somponnat Sampattavanich, Adisak Wongkajornsilp. Reversal of iNKT cell dysfunction in cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3600.

Abstract 894: Radiomics at baseline MRI are associated with tumor shrinkage in patients with unresectable renal cell carcinoma treated with neo-adjuvant Cabozantinib

Abstract Background: Neoadjuvant Cabozantinib targeted therapy (nCabo) has been shown to facilitate tumor size reduction in patients with renal cell carcinoma (RCC). However, there is unmet clinical need to identify pre-treatment markers predictive of response to nCabo to limit financial, dose-related toxicity. We investigated computationally derived radiomic signatures from baseline magnetic resonance imaging (MRI) for their association with response to tumor shrinkage following nCabo.Methods Seventeen patients with non-metastatic, clinical stage ≥T3, biopsy-confirmed clear cell RCC were enrolled in a phase II clinical trial (NCT04022343) examining primary tumor response to nCabo. Patients underwent 3 Tesla MRI at baseline, 6 and 12 weeks. Partial response (PR) or stable disease (SD) was determined per Response Evaluation Criteria in Solid Tumors at 12 weeks. Tumor regions of interest (ROI) were delineated on axial, arterial phase T1-weighted (T1W) series under the guidance of expert radiologist. T1W were normalized with respect to enhancement in cortex region of kidney. 75 radiomic features quantifying texture heterogeneity were derived from tumor ROI on a per-voxel basis at baseline. Wilcoxon ranksum test was used to evaluate significant differences in radiomics between patient groups PR and SD. Results: Following nCabo, 6/17 patients experienced PR. 22 radiomic features from T1W quantifying intensity based heterogeneity showed significant differences between patients with SD and PR after nCabo (p<0.05; top 3 in Table). None of the clinical variables showed significant differences between SD and PR. Conclusion: In this proof-of-concept preliminary study, we observed that radiomics at baseline MRI may allow for identifying RCC patients who would favorably respond to nCabo in terms of tumor shrinkage. Future studies will include analysis on longitudinal data, correlation against survival on large-scale datasets. Association between tumor shrinkage following nCabo and radiomic features, clinical variables Stable Disease (N=6) Partial Response (N=11) Category Feature P-value median IQR median IQR Radiomic Haralick 0.01 1.50 0.51 2.31 0.51 Gradient Filter 0.02 88.06 107.28 289.58 107.28 CoLlAGe 0.03 224.28 10.73 210.50 10.73 Clinical Age 0.12 56.00 14.00 52.50 14.00 BMI 0.48 29.90 8.50 27.30 8.50 modified Glasgow Prognostic Score 0.21 1.00 1.00 0.00 1.00 Baseline Tumor Size (cm) 0.48 9.50 5.15 9.50 5.15 ECOG PS at presentation 0.23 0.00 1.00 0.00 1.00 Charlson Comorbidity Index 0.72 6.00 6.00 4.00 6.00 Citation Format: Liping LI, Edouard Nicaise, Benjamin Schmeusser, Abhishek Midya, Amir Davarpanahfakhr, Anant Madabhushi, Mehmet Asim Bilen, Viraj A. Master, Rakesh Shiradkar. Radiomics at baseline MRI are associated with tumor shrinkage in patients with unresectable renal cell carcinoma treated with neo-adjuvant Cabozantinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 894.

Abstract 6500: Dependence of EGFR-mutant NSCLC on MET as demonstrated by vebreltinib, a novel and selective brain-penetrating MET kinase inhibitor

Abstract Background: Although EGFR inhibitors (EGFRi), preferably osimertinib, have offered substantial benefit for the classical plus T790M EGFR-mutant NSCLC patients, drug resistance develops and poses a critical challenge for long-term survival. The resistance is rooted to either on-target secondary EGFR mutations or compensatory oncogenic pathways bypassing EGFRi intervention, one of which appears to be treatment-acquired MET amplification (METamp). In this study we set out to understand the conditions when the tumor cells become dependent on MET. Methods: NSCLC patient-derived tumor models (PDX) carrying classical and T790M EGFR driver mutations were selected based on EGFRi history and concurrent MET gene copy numbers or RNA expression levels: Type 1) resistant to osimertinib with METamp; Type 2) partially resistant to osimertinib with METamp; and Type 3) sensitive to osimertinib with low MET expression, no METamp. These PDX xenograft mice were treated with vebreltinib (APL-101) at clinically relevant doses as single agent or in combination with osimertinib. The pharmacodynamic effects on EGFR and MET phosphor (P)- and total proteins were analyzed from tumor samples harvested during and at the end of treatments. Results: Vebreltinib single agent inhibited tumor growth of the type-1 PDX. One such PDX was resistant to chemotherapies, BRAF inhibitor and EGFRi including osimertinib, was inhibited by vebreltinib with ED50 of 3 mg/kg (p.o/q.d.). Another such PDX tumor appeared to be eradicated by vebreltinib treatment at 10 mg/kg (p.o/q.d.) and the mice became tumor-free on Day 18 and remained so after dosing stop on day 21 with last observation at study end (Day 70). In comparison, reference METi savolitinib showed only partial tumor size reduction against the same PDX tumor, not as durable as vebreltinib, and did not eradicate tumor growth at the same dose as vebreltinib or in combo with Osimertinib. Re-grown tumor after savolitinib osimertinib combo dosing stop was inhibited completely by vebreltinib follow-on treatment. In the type-2 PDX, tumor growth was partially inhibited by vebreltinib but was completely inhibited by combo of vebreltinib and osimertinib. The anti-tumor activity of vebreltinib in type-1 and type-2 PDX was associated with pharmacodynamic inhibition of P-MET and P-EGFR and MET protein degradation. In the type-3 PDX, tumor growth appeared to be eradicated by osimertinib and not inhibited by vebreltinib. However, addition of vebreltinib suppressed tumor re-growth after osimertinib dosing stop. Conclusion: EGFR-mutant NSCLC resistance to EGFRi may be dependent on MET pathway regardless of acquired METamp, whereas METamp may dictate the degree of MET dependence. Our data supports the hypothesis that adding vebreltinib to EGFRi overcome MET dependent resistance with durable effect or preventing MET dependent resistance to maximize therapeutic benefits. Citation Format: Xiaoling Zhang, Elaine Liu, Yan Song, Peony Yu, Sanjeev Redkar, Guo-Liang Yu. Dependence of EGFR-mutant NSCLC on MET as demonstrated by vebreltinib, a novel and selective brain-penetrating MET kinase inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6500.

Immunogenicity and effectiveness of an mRNA therapeutic vaccine for HPV-related malignancies.

Human papillomavirus (HPV) infections account for several human cancers. There is an urgent need to develop therapeutic vaccines for targeting preexisting high-risk HPV (such as HPV 16 and 18) infections and lesions, which are insensitive to preventative vaccines. In this study, we developed a lipid nanoparticle-formulated mRNA-based HPV therapeutic vaccine (mHTV), mHTV-02, targeting the E6/E7 of HPV16 and HPV-18. mHTV-02 dramatically induced antigen-specific cellular immune response and robust memory T-cell immunity in mice, besides significant CD8+ T-cell infiltration and cytotoxicity in TC-1 tumors expressing HPV E6/E7, resulting in tumor regression and prolonged survival in mice. Moreover, evaluation of routes of administration found that intramuscular or intratumoral injection of mHTV-02 displayed significant therapeutic effects. In contrast, intravenous delivery of the vaccine barely showed any benefit in reducing tumor size or improving animal survival. These data together support mHTV-02 as a candidate therapeutic mRNA vaccine via specific administration routes for treating malignancies caused by HPV16 or HPV18 infections.

Assessment of Anticancer Activity of Crude Ethanolic Extracts of Moringa Oleifera Pod and Leaves on 7,12 - Dimethylbenz Anthracene Induced Skin Cancer in Mice.

Background and Objective: Carcinoma of the skin is the commonest cancer in the world. This study aims to assess the anti-cancer effect of the ethanolic pod and leaf extracts of Moringa Oleifera on 7,12 - dimethylbenz anthracene (DMBA) induced skin carcinoma in mice. Methodology: Animals were divided into 6 groups of 5 each. 7,12 - dimethylbenz anthracene (DMBA) was used topically for four weeks to induce tumour. Group 1 received placebo, Group 2 - standard drug 5- Fluorouracil, Groups 3, 4 received pod extract and Groups 5,6 received leaf extract of Moringa Oleifera of concentration 500 and 1000mg/kg respectively for 3 weeks. Hematological and biochemical parameters such as Hemoglobin, RBC, WBC and platelet counts, SGOT and SGPT, blood urea nitrogen and serum creatinine were done before cancer induction and at the end of 7 weeks. Histopathological examination of the skin, liver and kidney were done at the end of 7 weeks. Results: There was reduction in tumor size in the Moringa Oleifera pod and leaf extract treated groups. Histopathology revealed infiltration of the cells with scarring of epidermis in the extract treated groups indicating the healing of tissues more pronounced at higher concentration. Control group showed atypical squamous cells whereas the standard drug treated group showed infiltration and scarring. Conclusion: This study exhibits a dose dependent anticancer effect of Moringa oleifera pod and leaf extracts in mice which was comparable with the standard drug 5-Fluorouracil.

Comprehensive evaluation of the relationship between biomarker profiles and neoadjuvant chemotherapy outcomes for breast cancer patients

BackgroundAccurately predicting the response to neoadjuvant chemotherapy (NAC) in breast cancer patients is crucial for guiding treatment strategies and enhancing clinical outcomes. Current studies have primarily focused on a limited set of biomarkers. More importantly, the results of many studies are in conflict. To address this, we conducted a comprehensive evaluation of the predictive value of a diverse range of clinically available molecular biomarkers in breast cancer, including HER2, ER, PR, TOPO II, EGFR, Ki67, CK5/6, AR, and p53. Additionally, we assessed changes in these biomarkers after NAC administration.MethodsOur study involved 189 patients with invasive breast cancer who underwent NAC at our institute. We examined biomarker profiles in core-needle biopsies taken before NAC and in surgical specimens obtained after NAC. We examined the association between these biomarkers and NAC outcomes, focusing on two main aspects: the rate of pathological complete response (pCR) and the reduction in tumor size. We used Chi-square and Mann-Whitney U tests to compare biomarker status changes between pCR and non-pCR patients. Linear regression analysis was employed to evaluate the relationship between biomarker status and tumor shrinkage rate. Additionally, we compared the expression status of these biomarkers before and after NAC using Chi-square and Wilcoxon signed-rank tests.Results and conclusionsOur results demonstrated significant differences in the expression levels of HER2, ER, PR, TOPO II, EGFR, and Ki67 between pCR and non-pCR patients, underscoring their potential as predictive markers for NAC outcomes. Importantly, our results have shed light on the contentious issue surrounding TOPO II in NAC outcome prediction. We have provided evidence that establishes a significantly positive association between TOPO II expression level and the pCR rate. Notably, tumor size was identified as a relevant predictive factor for achieving pCR. Regarding biomarker profiles, only Ki67 levels and TOPO II status exhibited changes following NAC, resolving previous controversies. While the ER and PR status remained unchanged, their expression values exhibited a slight but significant decrease post-NAC. Our results provide clarity and insights into the value and potential of using these biomarkers to predict NAC responses and prognosis in breast cancer patients.