Therapy For Treatment Of Cancer Research Articles

New approaches and prospects of immunotherapy and gene therapy for prostate cancer

Prostate cancer stands as the most prevalent cancer globally, constituting 21% of all cancer diagnoses in male patients. Urgent optimization of prostate cancer care is essential, given that this disease claims 345,000 lives every year. These innovative approaches hold substantial promise for both researchers and patients, representing a beacon of hope in the inhibitory act against prostate cancer. Prostate cancer's gradual advancement deems it suitable for immune therapy, but trials in metastatic cases show limited effectiveness, likely due to compromised immunity. Hindered by defective cellular responses, an immune-suppressive microenvironment, emerging evidence and breakthroughs, such as CAR-T therapy, inspire cautious optimism for advanced prostate cancer immunotherapy. Tumors utilize tactics to escape immune recognition, promoting the proliferation of MDSCs, Treg cells, and TAMs. Immunotherapy targets prostate cancer by mostly expressed target proteins and overexpressed target proteins. Immune cells play a role in tumor development and metastasis in advanced prostate cancer. Modulating the tumor microenvironment presents therapeutic possibilities. Certain prostate cancer types exhibit potential responses to immune checkpoint inhibitors, yet obstacles remain, necessitating additional research for enhanced efficacy. Immunotherapy faces hurdles in prostate cancer—limited inflammation, scarce antigens, and a resistant microenvironment. Grasping resistance intricacies is pivotal. The identification of DNA's helical structure propelled global progress in disease treatment through gene therapy. Choosing gene therapy vectors is critical; viruses are potent but toxic, while nonviral options, though less toxic, encounter barriers affecting transfection. In the realm of prostate cancer treatment, immunotherapy and gene therapy are emerging as increasingly viable options.

Dioon rzedowskii: An antioxidant, antibacterial and anticancer plant extract with multi-faceted effects on cell growth and molecular signaling

This study investigated the antioxidant, anticancer, antibacterial properties of Dioon rzedowskii extract, which had not been previously explored. We aimed to determine the extract's effect on liver and breast cancer cell lines and on solid Ehrlich carcinoma (SEC) mouse model to investigate the underlying molecular mechanisms. Three female albino mice groups were established: a tumor control group, a group treated with 100 mg/kg of the extract (D100), and a group treated with 200 mg/kg of the extract (D200) for 16 days after tumor development. Results showed that the D. rzedowskii extract inhibited cell growth in both MCF-7 and HepG2 cells in a concentration-dependent manner. This was achieved by suppressing the cell proliferation and inducing apoptosis. The extract also improved liver, heart, and kidney functions compared to the tumor control. Furthermore, oral administration of the extract reduced tumor volume and alleviated oxidative stress in tumor tissue. The anticancer effects were associated with overexpression of p53 and Bax and downregulation of cyclin D1 expression, which was attributed to decreased phosphorylated MAPK kinases. Additionally, D. rzedowskii exhibited antibacterial activity against K. pneumoniae isolated from cancer patients. The extract inhibited bacterial growth and reduced the membrane integrity. The study suggests that D. rzedowskii has promising potential as an adjunctive therapy for cancer treatment. Further investigations are needed to explore its combined anticancer efficacy. These results emphasize the value of natural products in developing compounds with potential anticancer activity and support a paradigm shift in cancer management to improve patients' quality of life.

New insights into the role of macrophages in cancer immunotherapy.

Macrophages are the main component of the tumor microenvironment, which are differentiated from monocytes in the blood and play an important role in cancer development. Tumor-associated macrophages (TAMs) can promote tumor growth, invasion, metastasis, and resistance to anti-programmed death receptor 1 therapy by regulating programmed cell death ligand 1 expression and interacting with other immune cells in the tumor microenvironment. However, when activated properly, macrophages can also play an anti-tumor role by enhancing the phagocytosis and cytotoxicity of tumor cells. TAM is associated with poor prognosis and drug resistance in patients treated with immunotherapy, indicating that macrophages are attractive targets for combined therapy in cancer treatment. Combination of targeting TAMs and immunotherapy overcomes the drug resistance and achieved excellent results in some cancers, which may be a promising strategy for cancer treatment in the future. Herein, we review the recent findings on the role of macrophages in tumor development, metastasis, and immunotherapy. We focus mainly on macrophage≥centered therapy, including strategies to deplete and reprogram TAMs, which represent the potential targets for improving tumor immunotherapy efficacy.

Tumor targeted nanohybrid for dual stimuli responsive and NIR amplified photothermal/photo-induced thermodynamic/chemodynamic combination therapy

The combination of photodynamic (PDT) and chemodynamic therapy (CDT) for cancer treatment has gathered a lot of attention in recent years. However, its efficacy is severely limited by elevated levels of hypoxia and glutathione (GSH) in the tumor microenvironment (TME). Multifunctional nanoparticles that can help remodel the TME while facilitating PDT/CDT combination therapy are the need of the hour. To this effect, we have developed O2 self-supplying, free radical generating nanohybrids that exhibit near infra-red (NIR) triggered photothermal (PTT)/photo-induced thermodynamic (P-TDT) and CDT for efficient breast cancer treatment. The surface of nanohybrids has been further modified by biointerfacing with cancer cell membrane. The biomimetic nanohybrids have been comprehensively characterized and found to exhibit high 2,2′-azobis-[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIPH) loading, GSH depletion, oxygen self-supply with TME responsive AIPH release. Biological activity assays demonstrate efficient cellular uptake with homotypic targeting, excellent hemo- and cytocompatibility as well as high intracellular reactive oxygen species generation with synergistic cytotoxicity against tumor cells. The multifunctional nanohybrid proposed in the present study provides an attractive strategy for achieving NIR responsive, tumor targeted PTT/P-TDT/CDT combination therapy for breast cancer treatment.

Pericyte signaling via soluble guanylate cyclase shapes the vascular niche and microenvironment of tumors

Pericytes and endothelial cells (ECs) constitute the fundamental components of blood vessels. While the role of ECs in tumor angiogenesis and the tumor microenvironment is well appreciated, pericyte function in tumors remains underexplored. In this study, we used pericyte-specific deletion of the nitric oxide (NO) receptor, soluble guanylate cyclase (sGC), to investigate via single-cell RNA sequencing how pericytes influence the vascular niche and the tumor microenvironment. Our findings demonstrate that pericyte sGC deletion disrupts EC–pericyte interactions, impairing Notch-mediated intercellular communication and triggering extensive transcriptomic reprogramming in both pericytes and ECs. These changes further extended their influence to neighboring cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) through paracrine signaling, collectively suppressing tumor growth. Inhibition of pericyte sGC has minimal impact on quiescent vessels but significantly increases the vulnerability of angiogenic tumor vessels to conventional anti-angiogenic therapy. In conclusion, our findings elucidate the role of pericytes in shaping the tumor vascular niche and tumor microenvironment and support pericyte sGC targeting as a promising strategy for improving anti-angiogenic therapy for cancer treatment.

Abstract 1689: CRISPR functional genetic screening for immune enhancers of inhibitor receptors in human primary CD8 T cells

Abstract The restrained efficacy of T cell therapies in cancer treatment is associated with T cell exhaustion (TEX), an impaired effector function state that is marked by distinct epigenetic landscape. These unique epigenetic features promoted the progression of TEX, hindered reinvigoration of TEX state and controlled the abnormal expression of inhibitor receptors (IRs), which could serve as target sites in cancer treatment. Thus, deciphering the regulatory elements in primary human T cells will deeply reveal the mechanism controlling TEX and provide novel therapeutic strategies to promote clinical response. However, how enhancers can be effectively applied in anti-cancer treatment is still poorly understood because high throughput identifying the functional enhancers of inhibitor receptors at scale is technically limited in human T cells. Here, we first developed a pooled screening platform that employs a compact CRISPRi system and enabled efficient one-step delivery of pooled screening libraries to primary human T cells. Leveraging this platform, we screened large genomic regions (~300kb) at saturation around key TEX genes, two IRs—PDCD1, HAVCR2 and one transcription factor (TF)—TBX21 to interrogate functional enhancers in human primary CD8 T cells. We identified two enhancers for PDCD1, three enhancers for HAVCR2 and three enhancers for TBX21, all of which are located over 12kb away from each gene’s transcription start sites. Then, to parse the essential sequences that fulfill enhancer function, we employed Cas9-based in-situ saturation mutagenesis screening to the identified enhancers of PDCD1 and HAVCR2. We found disrupt essential sequences impaired the entire enhancer function, quantitatively phenocopied the effect of targeting the entire enhancer with CRISPRi. Transcription factor motifs analyses of these sequences revealed potential regulation of ZFX for controlling PDCD1 expression and STAT for HAVCR2 expression. Finally, we explored the functional consequences of applying enhancers to anti-cancer treatment. Indeed, targeting the identified enhancers of PDCD1 and HAVCR2 in CAR T cells lead to enhanced cancer cell killing efficiency in vitro. Together, our study provides a platform and paradigm to interrogate functional enhancers in human T cells, illuminated the great potential of manipulating enhancers in T cell therapies. Citation Format: Ping Wang, Josephine R. Giles, Hua Huang, Junwei Shi, E.John Wherry. CRISPR functional genetic screening for immune enhancers of inhibitor receptors in human primary CD8 T 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 1689.

Abstract 66: A new mechanism of tumor immune escape: TCF19 promotes the development of novel terminally exhausted T cells through E2F and MYC transcription family

Abstract Introduction: ICB (immune checkpoint blocking) has been a promising therapy in cancer treatment, but there are still some patients do not response to this therapy. And it is well known that the majority cells reactivated to ICB are TCF1+ precursor exhausted T cells. Thus, studying the formation and heterogeneity of exhausted T cells are very necessary for improving the efficacy of ICB therapy. In this research, we identified a new population as TCF19+PD1+TIM3+ exhausted CD8+ T cells, which blocked the responds to ICB therapy. Methods: We collected single cell sequencing data, including colorectal cancer, gastric cancer, melanoma, and lung cancer, and drew tumor immune cells map through cluster analysis. Then using bioinformatics tools CytoTRACE. T and CCAT. A to calculate the differentiation of exhausted T cell populations, which discovered a new subset of highly proliferative and poorly differentiated terminal exhausted T cells. Subsequently, the existence of this group of cells was verified through in vitro experiments, and their formation mechanism and correlation with immunotherapy were further studied. Results: We utilized CytoTRACE.T and CCAT.A to predict differentiation states of terminally exhausted T cells. Then GEO and KEGG pathway gene set enrichment analysis were used. After analyzing, we found out that there was a subset of cells in terminally exhausted T cells defined as TCF19+PD1+TIM3+ Tex cells, which presented low differentiated and high proliferative potential.Then we performed multiple immunofluorescence staining and flow cytometry to verified the existence of TCF19+PD1+TIM3+ Tex cells in vitro. Clarifing the generation of these cell subset through regulating the expression of E2F and MYC transcription factor families.By collecting pathological sections of patients with immunotherapy information, we found that the amount of TCF19+PD1+TIM3+ Tex cells was inversely proportional to the efficacy of ICB, through immunofluorescence staining and immunohistochemical analysis as well as organoid models cocultured with T cells. Conclusion: In this research, we found a new subpopulation of terminal Tex cells, which showed high proliferation and low differentiation. For cells, TCF19 mediated the generation of stemness terminal Tex cells may through regulating the expression of E2F and MYC. Finally, we discovered that the existence of TCF19+PD1+TIM3+ Tex cells can predict the efficacy of ICB, that the more TCF19+PD1+TIM3+ Tex cells contained, the less efficacy of ICB in patients.This finding may provide a new research direction for immunotherapy. Thus, more attention should be paid to this new cell subset. Citation Format: Fuhui Wang, Nan Dong, Changhua Zhang. A new mechanism of tumor immune escape: TCF19 promotes the development of novel terminally exhausted T cells through E2F and MYC transcription family [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 66.

Abstract 94: Interrogation of STING induced cytokines in the tumor microenvironment using an Integrated MultiOmyx-RNAscope panel for spatial and quantitative profiling

Abstract The STING (Stimulator of Interferon Genes) pathway is a pivotal player in the innate immune response, responsible for detecting cytosolic accumulation of endogenous DNA and initiating a cascade of events leading to the production of pro-inflammatory type I interferons, which promote an antitumor environment through activation of T cells, dendritic cells, and natural killer cells. Therefore, STING agonists are currently being explored as a potential therapeutic for cancer treatment, often in combination with immune checkpoint inhibitors. While the STING pathway can be stimulated in multiple cell types, activation in antigen presenting cells, such as dendritic cells (DC), is crucial for antitumor activity in the tumor microenvironment (TME). Additionally, the type 1 interferon family consists of multiple subtypes, including IFNb and IFNa, which can produce differential biological responses. Although the STING pathway is known to induce expression of multiple cytokines, combined spatial characterization of STING and type I interferons in the TME has not been performed. To characterize STING-interferon expression in the TME, we use the Integrated MultiOmyx-RNAscope platform. MultiOmyxTM (NeoGenomics Laboratories, Inc) is a proprietary multiplex immunofluorescence (mIF) platform for the visualization and characterization of up to 60 protein biomarkers in a single formalin-fixed paraffin-embedded (FFPE) section and offers high-resolution spatial and quantitative analysis of protein expression in tissue samples. RNAscopeTM (Bio-Techne) Multiplex is a highly sensitive fluorescent in-situ hybridization (ISH) assay that can detect up to 3 RNA markers in a single FFPE section. The Integrated MultiOmyx-RNAscope assay allows for simultaneous detection of both protein and RNA markers in a single sample. Herein we report the design and use of a novel panel of commercially-available antibodies and ISH probes broad enough to characterize various immune subpopulations and cytokine expressing cells, including DCs and interferons, in the TME of a variety of tumor indications including melanoma and head and neck squamous cell carcinoma. Quantification and analysis will be performed using NeoLYTXTM, the proprietary MultiOmyx Analytics pipeline, to examine the spatial distribution and expression levels of key STING pathway induced cytokines to elucidate the dynamic communication of signaling molecules and their localization within specific cell populations. Understanding of the variety and phenotype of STING/cytokine expressing cells in the TME is crucial to define the populations being targeted by therapies for cancer treatment. Citation Format: Sandra Lam, Courtney Todorov, Jiong Fei, Harry Nunns, Eric Leones, Marianne Thio, Flora Sahafi, Erinn Parnell, Qingyan Au. Interrogation of STING induced cytokines in the tumor microenvironment using an Integrated MultiOmyx-RNAscope panel for spatial and quantitative profiling [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 94.

Abstract 2029: Investigation of anti-tumor activity of porcine myeloperoxidase for urothelial carcinoma of the bladder

Abstract Introduction: Porcine myeloperoxidase (pMPO) is a cationic enzyme secreted by granulocytic leukocytes capable of selectively binding cancer cells due to their negative surface charge. In the presence of hydrogen peroxide (H2O2) and sodium chloride (NaCl), MPO catalyzes the production of electronically excited singlet molecular oxygen, which exerts focused cytotoxic activity against cancer cells. Methods: Human bladder non-cancer (SV-HUC1) and cancer cells (T24 and 5637) were used to assess differential cytotoxic activity of pMPO. pMPO was combined with associated reagents, including H2O2, NaCl, and L-proline and glycine for 45 minutes to support the generation of singlet oxygen. MTS assay was used to assessed cell viability at day 3 post-treatment. Non-cancer and cancer cells were labeled with GFP and mCherry, respectively, via infection with lentivirus and cultured in tandem to allow for simultaneous treatment of both cell types. After the treatment, flow cytometry and microscopy were used to monitor the growth of the cells. Results: No cytotoxicity was noted when SV-HUC1 cells were cultured with individual reagents pMPO, NaCl, L-Proline, or Glycine, and limited cytotoxicity was observed with H2O2. Notably, cell viability was nearly maximally preserved for SV-HUC1 cells. The combination of pMPO with associated reagents resulted in killing of 5637 and T24 cells, with tumoricidal activity maintained across increasing tumor cell density, with cell viability preserved for SV-HUC1 cells. Within the cell co-culture system, simultaneous treatment of both cell types with the pMPO treatment resulted in selective killing of tumor cells and preservation of SV-HUC1 cells. Mechanistic studies confirm specificity of pMPO binding to tumor cells, and further, high levels of expression of gammaH2AX and phospho-ATM in 5637 and T24 cells following treatment. Conclusion: pMPO demonstrates selective and efficient killing of bladder cancer cells with minimal cytotoxicity against non-cancer urothelial cells. Given its reliance on direct surface contact with tumor cells for activity, pMPO may be developed as an intravesical therapy for treatment of non-muscle invasive bladder cancers. Acknowledgements: This work was partially supported by Mayo funds provided to Dr. Haojie Huang. Citation Format: Junnan Liu, Robert C. Allen, Jackson T. Stephens, Paras Shah, Haojie Huang. Investigation of anti-tumor activity of porcine myeloperoxidase for urothelial carcinoma of the bladder [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 2029.

Abstract 3979: PD-1 signals regulate NKG7 that is required for CD8+ T cells to sustain cytotoxicity and durable antitumor memory responses

Abstract Cytotoxic CD8+ T cells play a key role in response to anti-PD-1/PD-L1 immune checkpoint inhibitors (ICI) therapy. However, the exact effector molecules that are regulated by PD-1 signals in cytotoxic CD8+ T cells have not been completely defined. Lack of this knowledge is a crucial problem in addressing how to overcome the low clinical response rate to ICI therapy. When exploring why certain patients not responding to ICI therapy, we found non-responders did not have an elevated NKG7 expression in CD8+ T cells as responders to ICI therapy. The difference in NKG7 expression in CD8+ T cells between non-responders and responders to anti-PD-1 therapy prompted us to investigate the potential role of PD-1 signaling in regulating NKG7 expression. To that end, we generated a CD8+ T cell-specific Pdcd1 conditional knockout mice (CD8 E8ICre-Pdcd1fl/fl, also known as CD8-PD-1 cKO) where Pdcd1 is deleted after thymic selection of single positive CD8+ T cells. We observed a delayed tumor growth and prolonged survival in CD8-PD-1 cKO mice compared to control mice after B16-OVA melanoma tumor challenge. On Day 12, when the CD8-PD-1 cKO mice demonstrated their ability to control tumor growth, we conducted single cell RNA sequencing on isolated tumor infiltrating CD8+ T cells, revealing a significant increase of Nkg7 expression in effector CD8+ T cells in the Pdcd1 deficient CD8+ T cells compared to the control wild type T cells. Pdcd1-deficient effector CD8+ T cells also had increased expression of genes linked to NFAT/Calcineurin signaling pathway including Nfatc1, S100a4, Tbet and Tox, suggesting Nkg7 could be regulated by Pdcd1 via the NFAT pathway. To determine the impact of increased NKG7 expression in CD8+ T cells, we used OVA protein as a surrogate tumor antigen in vaccination. We found a complete B16-OVA tumor rejection in CD8-PD-1 cKO mice compared to control mice when tumor cells were injected on day 7 after vaccination with OVA protein and poly (I:C) (as an adjuvant), but only a partial rejection on day 21. The CD8-PD-1 cKO mice that were tumor-free for 30-40 days rejected 2nd tumor challenge with B16-OVA tumors. This long-term protection is tumor antigen (OVA) specific because these mice did not reject B16F10 tumor cells that do not express OVA antigen. We also found effector memory CD8+ T cells with high cytotoxicity increased in the spleen of CD8-PD-1 cKO mice after OVA antigen immunization compared to control. In conclusion, we found NKG7 is one of the effector molecules in cytotoxic CD8+ T cells, which can be regulated by PD-1 signals through NFAT signaling. Targeting the PD-1-NFAT pathway may be a new option to overcome low responses of T cells to ICI therapy in treatment of refractory cancer. Citation Format: Zhiming Mao, Joanina Gicobi, Jacob Hirdler, Xin Liu, Michelle Hsu, Emilia Dellacecca, Wenjing Zhang, Fabrice Lucien-Matteoni, Hai dong. PD-1 signals regulate NKG7 that is required for CD8+ T cells to sustain cytotoxicity and durable antitumor memory responses [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 3979.

Abstract 2745: Sequential tracking of PD-L1 expression on circulating epithelial tumor cells (CETCs) in men with primary non-metastatic prostate cancer

Abstract Background: Radiotherapy (RT) is an essential component of multimodality therapy in the primary or postoperative treatment of prostate cancer with curative intent by preventing local recurrence and distant metastases, indicating its impact on residual occult tumor, such as circulating tumor cells. Immunogenic changes in cancer cells induced by RT can lead to adaptive up-regulation of PD-L1 expression. As immune checkpoint inhibition plays an increasingly important role in prostate cancer, radiogenic PD-L1 upregulation may be of therapeutic importance. The aim of this study was to determine PD-L1 status on CETCs before and during RT. Methods: Peripheral blood samples were collected from 52 primary non-metastatic prostate cancer patients. CETCs were enumerated and analyzed for PDL-L1 expression prior to (baseline), 3 and 6 weeks after the start of RT using fluorescence scanning microscopy. Results: PD-L1 expression was detectable in CETCs and localized in the membrane and/or cytoplasm. We found a correlation between PD-L1 status in CETCs and aggressiveness of cancer disease prior to RT. The frequency of PD-L1 positive CETCs depended on the grading and Gleason score of the primary tumor. Patients with a high Gleason score and G3 tumors had significantly more PD-L1 positive CETCs compared to patients with a low Gleason Score and G1 tumors. Moreover, patients in stage I/II had significantly less PD-L1 positive CETCs compared to patients in stage III/IV (mean 54.25 vs. mean 69.65; p<0.05). A higher number of PD-L1 positive CETCs were detected in patients who had radical prostatectomy before start of RT than in those who had no surgical intervention (mean 66.24 vs. mean 47.46; p<0.01). Interestingly, the fraction of PD-L1 positive CETCs decreased significantly during RT only in patients with G3 tumors and a high Gleason Score. Conclusion: Our results indicated that PD-L1 in CETCs is closely related to the aggressiveness of the primary tumor and may be a co-factor associated with the progression of prostate cancer. PD-1/PD-L1 blockade combined with RT represents a novel and promising treatment strategy that could contribute to improve the treatment efficacy of prostate cancer. Citation Format: Dorothea Schott, Monika Pizon, Ulrich Pachmann, Katharina Pachmann, Matthias Mäurer. Sequential tracking of PD-L1 expression on circulating epithelial tumor cells (CETCs) in men with primary non-metastatic prostate 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 2745.

Abstract 640: In vivo rescue of p53 tumor suppressor function with ADGN-531 across Pan-p53 alterations

Abstract p53 tumor suppressor mutations result in loss of function of p53 in approximately 50% of all human cancers.TP53 missense, nonsense mutations and p53 deletion are present in about 50%, 12% and 5% of all p53 driven cancers, respectively. To date there is no effective treatment for rescuing p53 function in cancers using a pan-p53 approach. The use of ADGN-531 is a new potent strategy combining mRNA with a tumor selective peptide nanocarrier to rescue of p53 tumor suppressor function. ADGN-531 contains proprietary p53-mRNA complexed with proprietary short amphipathic peptides in the form of nanoparticles. ADGN-531 was evaluated on 20 different cancer cell lines harboring various p53 mutations. In-vivo efficacy of IV-administered ADGN-531 nanoparticles was evaluated on colorectal SW403 (p53 nonsense/KRASG12V), osteosarcoma SaOs2 (p53 null) and NSCLC NCI-H358 (p53 null/KRASG12C) mouse xenografts at a dose of 0.25-1.0 mg/kg weekly. ADGN-531/sotorasib synergy was evaluated in vitro on NCI-H358 (p53 null/KRASG12C) and Mia-PACA (p53R48W/KRASG12C) cells and in vivo on NCI-H358 mouse xenograft. ADGN-531 markedly inhibits the growth of a large panel of cancer cells harboring p53-missense or nonsense mutations or p53-deletion, by rescuing p53 transcriptional activity and subsequent expression of its target proteins. ADGN-531 induces cell cycle arrest in G1 due to p21 upregulation and apoptosis following BAX and PUMA activation. IV-administration of ADGN-531 resulted in dose responsive tumor growth inhibition in SaOs2, SW403 and H358 xenografts independent of KRAS status. We demonstrated a strong synergy in a NSCLC H358 xenograft (tumor regression 80%) when restoring P53 function with ADGN-531 (0.5mg/kg, weekly) along with inhibition of KRASG12C mutant using sotorasib (10mg/kg, daily). ADGN-531 potentiated the effect of sotorasib on sotorasib resistant cells harboring high level of KRASG12C in permanent active state. ADGN-531 treatments are well tolerated, no sign of clinical toxicity was detected after single or repeated administrations. ADGN-531 is effective in rescuing p53 function both in vitro and in vivo across a wide range of p53 alterations. Our study provides a proof-of-concept that restoration of tumor suppressor function by ADGN-531 could be used as a single agent therapy in P53 altered tumors independent of other driver mutations e.g., KRAS, or with other therapies for potent combinatorial cancer treatment. Citation Format: Gilles Divita, Audrey Grunenberger, Elodie Czuba, Veronique Josserand, Melanie Guidetti, Neil Desai. In vivo rescue of p53 tumor suppressor function with ADGN-531 across Pan-p53 alterations [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 640.

Abstract 2701: EREG reprograms M2-tumor-associated macrophage and suppresses colorectal cancer cell proliferation and migration

Abstract Colorectal cancer (CRC) represents a common malignancy within the digestive system, linked to significant morbidity and mortality rates. Tumors exert diverse effects on immune modulation, facilitating progression and metastasis. Amid the abundant immune cell populace within the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play a pivotal role. M2-type TAMs actively foster tumor growth and engage in immune suppression by fostering angiogenesis and tissue restructuring. In a previous study, we analyzed single-cell RNA-sequencing (scRNA-seq) data derived from colorectal cancer patients. We observed an enrichment of the secreted phosphoprotein 1 (SPP1)+ macrophage fraction in both the tumor core and border when compared to normal tissues. Additionally, epiregulin (EREG), an epidermal growth factor receptor (EGFR) ligand, was found to be upregulated in SPP1+ macrophages, correlating with tumor growth and metastatic tendencies. Research on EREG is important because it has been found to play a significant role in cancer progression, including colorectal cancer. Understanding the mechanisms by which EREG contributes to tumor growth and metastasis can provide valuable insights into the development of targeted therapies for cancer treatment. Our hypothesis centered around the impact of EREG from TAMs on tumor progression. To identify TAM-specific EREG and its functional significance, we isolated tumor-associated macrophages from CT26 (mouse colorectal carcinoma)-bearing tumors and cultured them with conditioned and normal mediums. Subsequently, we examined EREG expression at the gene level using quantitative PCR. Our findings indicated significantly higher levels of EREG in the conditioned medium compared to the normal medium, suggesting an association between EREG and cancer cells. Remarkably, our investigation also confirmed that EREG has the capacity to reshape macrophage signatures. Notably, the surface marker CD206, characteristic of M2 macrophages, exhibited a significant decrease, while iNOS, a marker for M1 macrophages, showed an increase upon EREG depletion. We evaluated the interaction between CT26 cancer cells and TAMs using indirect co-culture methods. EREG-depleted TAMs were plated in the top chamber, while CT26 colorectal cancer cells were seeded at the bottom. Our results validated that knocking down EREG in TAMs not only hindered the proliferation of cancer cells but also affected the behavior of TAMs. Additionally, the reduced EREG expression in TAMs hindered the migration of cancer cells. These findings strongly suggest that targeting EREG could effectively restrain the growth and metastasis of colorectal cancer cells by reprogramming macrophage polarization in the TME. Consequently, this indicates its potential as a promising therapeutic target in colorectal cancer. Citation Format: Ah-Ran Yu, Seijong Kim, Yelin Jeong, Hye Kyung Hong, Yong Jae Shin, Yong Beom Cho. EREG reprograms M2-tumor-associated macrophage and suppresses colorectal cancer cell proliferation and migration [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 2701.

Abstract 7128: Novel Ku-DNA binding inhibitors impact on the cellular and in vivo DNA damage response to radio- and radiomimetic-therapy

Abstract DNA-PK, the DNA-dependent protein kinase, is a validated target for cancer therapeutics that plays a central role in the non-homologous end joining (NHEJ) DNA repair pathway and the DNA damage response (DDR). NHEJ is a key mechanism of DNA double-strand breaks (DSB) repair, especially those induced by ionizing radiation (IR). Ku 70/80 heterodimer is required as initiator in this process, acting as an essential DNA-binding component of DNA-PK that senses DNA damage. Blocking the DNA-PK kinase activity in combination with DSB inducing agents has been widely used as a therapeutic strategy to drive clinical efficacy of radiation therapy for cancer treatment. We have reported a unique approach of DNA-PK inhibition by developing Ku-DNA binding inhibitors (Ku-DBi’s), small molecule inhibitors that target the interaction between Ku70/80 and DNA. Ku-DBi’s demonstrated a direct interaction with Ku70/80, a potent inhibition of Ku-DNA binding and DNA-PK catalytic activity, and in vitro and cellular NHEJ inhibitory activity. This results in the potentiation of non-small cell lung cancer (NSCLC) cellular sensitivity to DSB generating therapies, as a function of inhibiting DNA-PKcs autophosphorylation and dysregulation of signaling to the DDR. In this study, we have expanded our structure activity relationship analyses to focus on optimizing selectivity, cellular uptake and Ku inhibitory activity. The new series of Ku-DBi’s include oxindole derivatives of the X80 core structure that achieve these goals. These novel compounds display increased cellular uptake while retaining potent Ku inhibitory activity and enhanced cellular inhibition on DNA-DSB repair. Ku-DBi’s optimization has enabled in vivo analyses of Ku-DBi - ionizing radiation combination therapy in human xenograft models of non-small cell lung cancer. The impact of Ku-DBi treatment on therapeutic efficacy, toxicity, Ku/DNA-PK inhibition, and DDR signaling will be presented. These data represent a significant advance in the development of Ku-DNA binding inhibitors and their therapeutic intervention for cancer treatment. Citation Format: Pamela L. Mendoza-Munoz, Dineshsinha Chauhan, Navnath S. Gavande, Joseph R. Dynlacht, Joy E. Garrett, John J. Turchi. Novel Ku-DNA binding inhibitors impact on the cellular and in vivo DNA damage response to radio- and radiomimetic-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 7128.

Abstract 4034: Lag3 blockade enhances the anti-tumor effect of dual GITR agonism and PD-1 blockade in a preclinical melanoma model

Abstract Immune checkpoint blockade (ICB) therapies, specifically anti PD-1 and anti CTLA-4, have resulted in tremendous success in the clinic. However, a substantial number of patients still relapse due to either inherent or acquired resistance to ICB therapies. In this scenario, activation of T cell co-stimulation pathways along with ICB emerges as a promising strategy to improve anti-tumor responses. Engagement of Glucocorticoid induced TNFR Related protein (GITR) costimulatory molecule, leads to enhanced activation of cytotoxic T cells while destabilizing suppressive T regulatory cells in the tumor microenvironment. Additionally, combining GITR agonism with PD-1 blockade improves the anti-tumor response in a murine model of advanced melanoma resistant to ICB, positioning GITR as an attractive immunotherapeutic target. In this study, we evaluated the therapeutic efficacy of combining blockade of the immune checkpoint LAG3 with GITR agonism for treating ICB-resistant advanced melanoma, using the B16 model. The combination of LAG3 blockade with GITR agonism was well tolerated, leading to better tumor control and improved survival. Our data revealed increased B cell infiltration and activation within tumors and draining lymph nodes (LNs) of treated mice. B cell depletion diminished the anti-tumor effect of the combination therapy, suggesting that B cells play an active role in controlling tumor growth. Spleens from treated mice exhibited increased lymphocytic hyperplasia, along with more and larger germinal centers. B cell receptor sequencing revealed an increased clonality and reduced entropy. Treating B cells with GITR agonism and LAG3 blockade in vitro led to increased activation and proliferation, suggesting a direct effect of these therapies on B cells. Furthermore, adding LAG3 blockade to the dual combination of GITR agonism and PD-1 blockade resulted in superior tumor control and increased B cell activity in the draining LNs. Collectively, our findings suggest that the humoral response significantly contributes to the anti-tumor responses elicited by ICB when combined with GITR agonism. This triple combination therapy (LAG3 blockade + PD1 blockade + GITR agonism) holds promise as a safe and potent therapeutic strategy to overcome ICB resistance. Further investigation into the mechanism of action by which GITR agonism leads to enhanced B cell responses when combined with ICB is warranted in order to design more effective therapies for cancer treatment. Citation Format: Rachana R. Maniyar, Yuval Elhanati, Levi Mangarin, Yacine Marouf, Ashley Ahmed, Benjamin Greenbaum, Jedd Wolchok, Taha Merghoub. Lag3 blockade enhances the anti-tumor effect of dual GITR agonism and PD-1 blockade in a preclinical melanoma model [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 4034.

Effectiveness of the total neo-adjuvant therapy in rectal cancer treatment. Results of the randomized trial

To ASSESS effectiveness of total neoadjuvant therapy (TNT) for patients with rectal carcinoma.Patients and methods: patients with histologically proven rectal carcinoma were randomly assigned in two groups: in the TNT group after the neoadjuvant CRT 50-54 Gy with capecitabine 3 consolidation courses of XELOX were done, in the CTR group - conventional neoadjuvant CRT 50-54 Gy with capecitabine. At the end of the treatment, effect was assessed by MRI using the mrTRG scale. For patients with a full clinical response, who have refused surgery, «watch&wait» approach was used. For other patients effect of neoadjuvant therapy was evaluated by pathomorphological study using the Ryan scale. The primary endpoint of study was the complete response rate (clinical and pathomorphological). Secondary endpoints of study: frequency and structure of intraoperative and postoperative complications, the rate of grade 3–4 toxicity of radiotherapy and chemotherapy, R0-resection rates. The study was registered on the ClinicalTrials.gov (NCT04747951)RESULTS: between October 2020 and October 2023, 183 patients were enrolled in the randomized study: 91 patients in the TNT group and 92 patients in the CRT group. At median (Q1, Q3) follow-up period 24 (14; 28) months, complete clinical response observed in 23% (14/60) of TNT patients and in 7% (5/71) of THL patients (p=0.008). The pCR rate was 20% (9/45) in the TNT group and 8% (5/66) in the CRT group (p=0.05). The frequency of development of toxic reactions of degree 3-4, the frequency and structure of intra- and postoperative complications, as well as the frequency of R0 resection of the group did not differ statistically significantly. The total rate of Grade 3–4 toxicity, rate of intra- and postoperative complications, R0-resections rate did not differ between two groups.CONCLUSION: preliminary results of a randomized study demonstrated the effectiveness and safety of total neo-adjuvant therapy in rectal cancer treatment.

The Survival Benefit of Pegylated Liposomal Doxorubicin-Based Neoadjuvant Chemotherapy in the Management of Breast Cancer.

Purpose: This study aims to evaluate the short-term outcomes and prognosis and the cardiac safety of pegylated liposomal doxorubicin (PLD)-based neoadjuvant chemotherapy (NAC) compared with epirubicin-based therapy in breast cancer treatment. Methods: In total, 304 patients diagnosed with stages II and III breast cancer were enrolled that included 97 cases treated with PLD and 207 controls treated with epirubicin in NAC. The effectiveness of the antibreast cancer treatment was evaluated using overall survival (OS) and disease-free survival (DFS) metrics, whereas cardiac toxicity was measured through the left ventricular ejection fraction (LVEF) and electrocardiogram (ECG) assessments. Results: The 5-year DFS and OS rates in the PLD group were 84.5% and 88.7% (with 15 recurrences and 11 deaths), respectively, whereas in the control group, these rates were 72.9% and 79.2% (with 56 recurrences and 43 deaths). Regarding cardiac toxicity, there was no significant difference in ECG abnormalities or LVEF decline between the two groups. Conclusions: The study suggests that PLD-based NAC may provide substantial benefits in terms of DFS and OS, along with a safe cardiac toxicity profile, in patients with stage II-III breast cancer.

Cancer Treatment Disparities in People With HIV in the United States, 2001-2019.

People with HIV (PWH) have worse cancer outcomes, partially because of inequities in cancer treatment. We evaluated cancer treatment disparities among PWH, including an assessment of changes in disparities over time. We used data from the HIV/AIDS Cancer Match Study, a population-based HIV and cancer registry linkage to examine diffuse large B-cell lymphoma (DLBCL), Hodgkin lymphoma (HL), and cancers of the cervix, lung, anus, prostate, colon, and female breast. Outcomes included receipt of (1) any cancer treatment and (2) standard therapy among patients with local-stage cancer. We assessed associations between HIV and each outcome by estimating adjusted prevalence odds ratios (aORs) with 95% CI and trends over time. We identified predictors of nonreceipt of cancer treatment in PWH. From 2001 to 2019, compared with people with cancer without HIV (n = 2,880,955), PWH (n = 16,334) were more likely to not receive cancer treatment for cervical cancer (aOR, 2.03 [95% CI, 1.52 to 2.70]), DLBCL (aOR, 1.53 [95% CI, 1.38 to 1.70]), HL (aOR, 1.39 [95% CI, 1.19 to 1.63]), lung cancer (aOR, 1.79 [95% CI, 1.65 to 1.93]), prostate cancer (aOR, 1.32 [95% CI, 1.21 to 1.44]), colon cancer (aOR, 1.73 [95% CI, 1.43 to 2.08]), and breast cancer (aOR, 1.38 [95% CI, 1.07 to 1.77]). Similar associations were observed in PWH with local-stage cancers although no difference was observed for anal cancers. The association between HIV and nonreceipt of cancer treatment significantly decreased over time for breast, colon, and prostate cancers (all P trend <.0001), but PWH remained less likely to receive treatment in 2014-2019 for DLBCL, cervix, and lung cancers. Among PWH, Black individuals, people who inject drugs, and those 65 years and older were less likely to receive cancer treatment. Disparities in receipt of cancer treatment persist for PWH in the United States in contemporary time periods. Solutions to address inequitable receipt of cancer treatment among PWH are urgently needed.

Future directions on Antibody-Drug Conjugates in HER-2 negative Breast Cancer: a Comprehensive Review of New Agents

&#x0D; &#x0D; &#x0D; &#x0D; Background: Breast Cancer is the most frequent malignancy in women with a rising incidence. Antibody-drug conjugates targeting HER2 and TROP-2 are new tools already effective against breast cancer but ADCs targeting new transmembrane receptors are necessary to overcome the dependence on HER-2 pathway. New trials are emerging fast as new ADCs are under investigation. Methods: We reviewed ClinicalTrials.gov and Pubmed for early clinical trials on new ADCs in clinical development for HER-2 negative breast cancer. Results: Trials testing 12 new molecules were found. Pre-clinical studies, safety and results in phase I/II trials published of each new molecule were reviewed and described briefly. Side effects regarding ADCs with maytansine derivatives (DM1/4) or auristatins (MMAE/MMAF) payloads were described. Conclusion: ADCs represent a practice-changing therapy for cancer treatment. New compounds against several new targets are expected to become part of clinical practice in the near future.&#x0D; &#x0D; &#x0D; &#x0D;

A Genome-Wide Association Study of Endoxifen Serum Concentrations and Adjuvant Tamoxifen Efficacy in Early-Stage Breast Cancer Patients.

Tamoxifen is part of the standard of care of endocrine therapy for adjuvant treatment of breast cancer. However, survival outcomes with tamoxifen are highly variable. The concentration of endoxifen, the 30-100 times more potent metabolite of tamoxifen and bioactivated by the CYP2D6 enzyme, has been described as the most relevant metabolite of tamoxifen metabolism. A genome-wide association study (GWAS) was performed with the objective to identify genetic polymorphisms associated with endoxifen serum concentration levels and clinical outcome in early-stage breast cancer patients receiving tamoxifen. A GWAS was conducted in 608 women of the CYPTAM study (NTR1509/PMID: 30120701). Germline DNA and clinical and survival characteristics were readily available. Genotyping was performed on Infinium Global Screening Array (686,082 markers) and single nucleotide polymorphism (SNP) imputation by using 1000 Genomes. Relapse-free survival during tamoxifen (RFSt) was defined the primary clinical outcome. Endoxifen serum concentration was analyzed as a continuous variable. Several genetic variants reached genome-wide significance (P value: ≤5 × 10-8). Endoxifen concentrations analysis identified 430 variants, located in TCF20 and WBP2NL genes (chromosome 22), which are in strong linkage disequilibrium with CYP2D6 variants. In the RFSt analysis, several SNP were identified (LPP gene: rs77693286, HR 18.3, 95% CI: 15.2-21.1; rs6790761, OR 18.2, 95% CI: 15.5-21.1). Endoxifen concentrations have a strong association with the chromosome 22, which contains the CYP2D6 gene.