Breast Cancer Research Articles

Synthesis of targeted doxorubicin-loaded gold nanorod −mesoporous manganese dioxide core–shell nanostructure for ferroptosis, chemo-photothermal therapy in vitro and in vivo

In the current study, a core–shell inorganic nanostructure comprising a gold nanorod core and −mesoporous manganese dioxide shell was synthesized. Then, the mesoporous manganese dioxide shell was loaded with doxorubicin (DOX) and then coated with pluronic F127 and pluronic F127-folic acid conjugate (1.5:1 wt ratio of pluronic F127: pluronic F127-folic acid conjugate) to prepare targeted final platform. In this design, mesoporous manganese dioxide acted as a reservoir for DOX loading, anti-hypoxia, and MRI contrast agent, while the gold nanorod core acted as a photothermal and CT scan imaging agent. DOX was encapsulated in the mesoporous manganese dioxide shell with a loading capacity and loading efficiency of 19.8 % ± 0.2 and 99.0 % ± 0.9, respectively. The in vitro release experiment showed the impact of glutathione (GSH), mildly acidic pH, and laser irradiating toward accelerated stimuli-responsive DOX release. The ·OH production of the prepared platform was verified by methylene blue (MB) decomposition reaction. Furthermore, thermal imaging exhibited the ability of the prepared platform to convert the NIR irradiation to heat. In vitro cytotoxicity tests on the folate receptor-positive 4 T1 cell line revealed the remarkable cytotoxicity of the targeted formulation compared to the nontargeted formulation (statistically significant). The MTT experiment demonstrated that exposure to laser 808 irradiation enhanced cytotoxicity of the targeted formulation (p < 0.0001). The production of ROS in 4 T1 cells following treatment with the targeted formulation was demonstrated by the dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay. Furthermore, in vivo investigations by implementing subcutaneous 4 T1 tumorized female BABL/c mice indicated that the prepared platform was an effective system in suppressing tumor growth by combining chemotherapy with PTT (photothermal therapy). Additionally, simultanous PTT and anti-hypoxic activity of this system showed potent tumor growth suppression impact. The percent of tumor size reduction in mice treated with FA-F127-DOX@Au-MnO2 + 808 nm laser compared to the control group was 99.7 %. The results of the biodistribution investigation showed tumor accumulation and modified pharmacokinetics of the targeted system. Lastly, 6 and 24 h post-intravenous injection, CT-scan and MR imagings capability of the prepared platform was verified in preclinical stage. The prepared multipurpose system introduces great opportunity to provide multiple treatment strategy along with multimodal imaging capability in a single platform for breast cancer treatment.

Assembly of Dye Molecules in Covalent Organic Frameworks for Enhanced Colorimetric Biosensing.

Colorimetric assays have been extensively investigated for biosensing applications due to their advantages of visual recognizability, ease of use, and low cost. However, advancing their development is a great challenge due to the inherent limitations of colorimetric dyes. Herein, we report a strategy to assemble dyes in covalent organic frameworks (COFs) to effectively reinforce the applicability of pH-responsive dyes in colorimetric bioassays. Experimental results reveal that three-dimensional COFs can promote the assembly of dyes through hydrogen bonding, resulting in the formation of a dye-supermolecule@COF assembly. Consequently, when sensitized at increased pH levels (e.g., hydroxyl ions), disruption of hydrogen bonds may trigger a rapid transition from their insoluble fixed state within the COFs into soluble, visibly detectable dye anions. This process can also be facilitated by increased hydrophilicity and elevated electrostatic repulsion between the dye anions and COFs, leading to the substantial release of chromogenic dye anions from the COF pores into the solution, thereby amplifying the colorimetric signal output. Therefore, by employing various synthesized dye-supermolecule@COFs as signal tags, we developed a colorimetric bioassay capable of accurately identifying breast cancer cell subtypes. This study not only highlights the effectiveness of dye-supermolecule@COFs in enhancing colorimetric biosensing but also underscores the potential of employing the COF-mediated dye assembly strategy for colorimetric assays.

Changes in peripheral NK cells during metastatic triple-negative breast cancer progression

Changes in peripheral NK cells during metastatic triple-negative breast cancer progression

Current approaches to the pharmacological management of metastatic breast cancer in older women.

A substantial majority of patients diagnosed with metastatic breast cancer consists of individuals 65-year-old or above. Emerging treatment approaches, which utilize genomics-guided therapy and innovative biomarkers, are currently in development. Given the numerous choices in the metastatic context, it is necessary to adopt a personalized approach to decision-making for these patients. The authors provide a comprehensive analysis of the existing literature on the use of systemic anticancer treatments in older women, specifically those aged 65 and above, who have metastatic breast cancer, focusing on the reported effectiveness and adverse effects of these treatments in this population. The evidence to treat older patients with metastatic breast cancer primarily relies on subgroup analyses, whose interpretation should be approached with caution. In several clinical trials subgroup analysis, it has been observed that this population seem to have comparable benefits and toxicities to younger patients, but real-world data have showed older women exhibit worse rates of survival compared to younger women. Multiple factors are likely involved in this, but we postulate this is related to lower rates of guideline concordant, and factors such as comorbidity, lack of social supports, malnutrition, and geriatric factors like frailty and/or vulnerability. This underscores the importance of a broader assessment for patients with a geriatric perspective and involvement of multi-disciplinary team.

Ligation-driven hyperbranched DNA assembly for label-free and sequence-specific measurement of RNA N6-methyladenosine in human breast tissues

N6-methyladenosine (m6A) is a critical post-transcriptional regulator, and it is linked to various biological functions (e.g., degradation, export, and translation) and multiple human diseases (e.g., cancers, immune disorders, and neurodegenerative diseases). The current methods for sequence-specific detection of m6A usually suffer from radioactive risk, large sample consumption, washing/separation steps, and false-positive signal. Herein, we develop a ligation-driven hyperbranched DNA assembly-based fluorescent biosensor for label-free and sequence-specific detection of m6A. In this assay, the unmethylated RNA can be identified and cleaved by m6A-sensitive endoribonuclease MazF. The retained intact m6A-RNA is complementary to the padlock probe to form a circular DNA, subsequently initiating ligation-driven hyperbranched rolling circle amplification (HRCA). The obtained HRCA products can be simply quantified with SYBR Gold as a fluorescent indicator. This method can be homogeneously carried out in an isothermal, label-free and antibody-free manner. The limit of detection can reach 0.079 pM. Moreover, this method can differentiate even 0.01 % m6A level in excess coexisting interferences, monitor cellular m6A RNA level with single-cell sensitivity, and differentiate m6A level in breast tumor tissues and normal adjacent tissues, with promising applications in m6A-releated epigenetic research and clinical diagnosis.

Physical Activity and Its Effects on Cancer Prevention, Survival Rates, and Recovery

Introduction and Objective: Physical activity is any movement using skeletal muscles. It can be classified into four main categories: occupational, household, transport and recreational. These activities can also vary in intensity. This article aims to describe how physical activity affects cancer prevention, survival rates and recovery. Review and Methods: Review and summary of studies and meta-analysis of studies available in open-source format on Google Scholar and PubMed. State of Knowledge: Extensive research shows that regular physical activity reduces the risk of several cancers, particularly breast, colon, and endometrial cancers. Epidemiological studies consistently find that more active individuals have a lower incidence of certain cancers. Physical activity is also a useful adjunct to treatment, alleviating its negative effects. The protective effect of physical activity is believed to be dose-dependent, with greater benefits from higher frequencies, durations, and intensities. Recent studies suggest that physical activity may also improve survival rates in cancer patients, particularly for prostate, colorectal, and breast cancers. Conclusions: The current data strongly supports the inclusion of regular physical activity as a key component of cancer prevention strategies. It may also be beneficial for cancer patients to enhance their chances of survival. Public health guidelines stress the importance of exercise to lower cancer risk and improve overall health.

TRF-Leu reverse breast cancer cells chemoresistance by regulation of BIRC5

ObjectiveAccumulating studies reported the crucial roles of tRFs in tumorigenesis. However, their further mechanisms and clinical values remains unclear. This study aimed at the further investigation of tRF-Leu in breast cancer chemotherapy resistance.MethodsThe high-throughput sequencing was performed and identified the downregulation of tRF-Leu in MCF7/ADR cells. The function of tRF-Leu in breast cancer cells and breast cancer chemotherapy resistance was investigated in vitro and in vivo, including colony formation assay, CCK-8 assay, transwell assay and apoptosis assay. The binding site of tRF-Leu on BIRC5 was verified by dual-luciferase assay.ResultstRF-Leu was downregulated in MCF7/ADR cells. Overexpression of tRF-Leu inhibited the migration of breast cancer cells. Furthermore, tRF-Leu could reverse the resistance of MCF7/ADR cells to Adriamycin both in vitro and in vivo. BIRC5 was a target of tRF-Leu, which might be involved in the chemotherapy resistance regulation.ConclusionWe demonstrated that tRF-Leu could inhibit the chemotherapy resistance of breast cancer by targeting BIRC5. These findings might identify new biomarkers of breast cancer therapy and bring new strategies to reverse chemotherapy resistance.

Tumorspheres as In Vitro Model for Identifying Predictive Chemoresistance and Tumor Aggressiveness Biomarkers in Breast and Colorectal Cancer

Chemoresistance remains a major challenge in the treatment of breast and colorectal cancer. For this reason, finding reliable predictive biomarkers of response to chemotherapy has become a significant research focus in recent years. However, validating in vitro results may be problematic due to the outcome heterogeneity. In this study, we evaluate the use of tumorspheres as an in vitro model for validating biomarkers of chemoresistance in breast and colorectal cancer. Our investigation highlights the crucial role of inflammation-related pathways in modulating the response to chemotherapy. Using in silico approaches, we identified specific markers elevated in responders versus non-responders patients. These markers were consistently higher in three-dimensional (3D) tumorsphere models compared to traditional adherent cell culture models. Furthermore, the number of tumorspheres from breast and colorectal cancer cells increased in response to cisplatin and oxaliplatin treatment, respectively, whereas cell viability decreased in adherent cell culture. This differential response underscores the importance of the 3D tumorsphere model in mimicking the tumor microenvironment more accurately than adherent cell culture. The enhanced chemoresistance observed in the 3D tumorspheres model and their correlation of data with the in silico study suggest that 3D culture models are a better option to approach the in vivo model and also to validate in silico data. Our findings indicate that tumorspheres are an ideal model for validating chemoresistance biomarkers and exploring the interplay between inflammation and chemoresistance in breast and colon cancer.

Differential prognostic value of residual nodal burden in breast cancer subtypes.

Residual cancer burden (RCB) index after neoadjuvant chemotherapy (NAC) is highly prognostic in patients with breast cancer (BC) but does not account for subtype or the precise impact of residual nodal burden (RNB). We aimed to precisely define the effect of RNB on survival by subtypes. Adult women with non-metastatic BC diagnosed from 2006 to 2021 in the National Cancer Database (NCDB) who received NAC followed by surgery within 8months were included. RNB was also evaluated as a predictor of mortality with multivariable logistic regression. Kaplan-Meier analyses were performed to compare overall survival. 51,917 patients were included. After adjustment, ypN stage was the strongest predictor of mortality, with an odds ratio (OR) of 2.24 (95% CI 2.08-2.41) for ypN1 vs ypN0 and increased with increasing nodal burden-ypN2 vs ypN0 OR 5.03, 95% CI 4.60-5.51 and ypN3 vs ypN0 OR 8.85, 95% CI 7.88-9.93. Stratification of survival curves with higher RNB is most pronounced for triple-negative breast cancer (TNBC) with an absolute difference of 64% in 5-year overall survival between ypN0 and ypN3 patients, and lowest for the ER+/HER2- subtype with a 25% absolute difference in 5-year OS between ypN0 and ypN3 patients. On interaction analysis, ypN status was a stronger predictor of mortality for the TNBC subtype compared to other subtypes. RNB has a significantly different impact on survival by BC subtypes. Future study of optimal therapeutic strategies for patients with residual nodal disease after NAC should account for subtype-specific differences in prognosis.

Study of microvascular density in carcinoma of breast

Study of microvascular density in carcinoma of breast

Abstract A077: The role of RhoV in basal-like pancreatic cancer

Abstract Background Pancreatic ductal adenocarcinoma is a devastating disease lacking targeted therapy. Basal-like pancreatic cancer is a tumor subtype with a worse clinical outcome than other subtypes. These cancers are characterized by the expression of basal keratins and mesenchymal markers. However, the genes that drive the basal-like phenotype are poorly understood. Ras homolog family member V (RhoV) is one of the Rho GTPases, and it has been demonstrated to drive the progression of lung and breast cancers. The current study aims to reveal the role of RhoV in basal-like pancreatic cancer. Design RhoV, p63, and CK5/6 were stained in sequential sections by immunohistochemistry. Expression of RhoV in pancreatic cancer and cell lines was reanalyzed based on the data from ProteinAtlas and Broad Insitute DepMap Portal. Basal cell line, BxPC3, and non-basal cell line, Panc1 were selected for functional evaluation based on their differentiated RhoV expression. RhoV gene was overexpressed and knocked down using the CRISPR/gRNA-based Lentiviral system, followed by sphere formation, colony formation, migration, and invasion assays. Results RhoV, p63, and CK5/6 were expressed in the same histologic location of basal pancreatic cancer. The gene expression level of RhoV was co-expressed with p63 (a classic basal marker) in four pancreatic cancer cell lines (broadinstitute.org). Knockout of RhoV by three runs of gRNAs in BxPC3 cells all significantly attenuated tumor sphere formation with less colony formation as compared to mock knockout. Overexpression of RhoV in non-basal-like cells, Panc 1, significantly increased the size of sphere formation, numbers of colony formation, and p38 activation compared to EV control. Cell migration and invasion assays showed the same RhoV-dependent migration and invasion in corresponding cells. Panc1 cells with RhoV knockout significantly generated smaller tumor xenografts in immunodeficient mice and RhoV overexpression led to larger tumor sizes. Conclusion Finding the driver of the basal-like phenotype helps to reveal the pathophysiology of the basal-like subtype of pancreatic cancer and facilitates the identification of new targets for therapeutic purposes. Our preliminary results indicated that RhoV, a small G protein from the Rho family of GTPases, played essential roles in tumor proliferation and progression, by activating the p38 signaling pathway. Further study will be focused on revealing Rhov's downstream pathways and exploring the role of RhoV in apoptosis/cell cycle, cell metabolism, autophagy, etc. in basel-like pancreatic cancer. Citation Format: Shang Wu, Jia Feng, Selina Gao, Ting Wang, Zebang Li, Yifei Liu, Chiung-Kuei Huang, Shaolei Lu. The role of RhoV in basal-like pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A077.

Integrative analysis of pan-cancer single-cell data reveals a tumor ecosystem subtype predicting immunotherapy response

Tumor ecosystem shapes cancer biology and potentially influence the response to immunotherapy, but there is a lack of direct clinical evidence. In this study, we utilized EcoTyper and publicly available scRNA-Seq cohorts from ICI-treated patients. We found a ecosystem subtype (ecotype) was linked to improved responses to immunotherapy. Then, a novel immunotherapy-responsive ecotype signature (IRE.Sig) was established and validated through the analysis of pan-cancer data. Utilizing IRE.Sig, machine learning models successfully predicted ICI responses in both validation and testing cohorts, achieving area under the curve (AUC) values of 0.72 and 0.71, respectively. Furthermore, using 5 CRISPR screening cohorts, we identified several potential drugs that may augment the efficacy of ICI. We also elucidated the candidate cellular biomarkers of response to the combined treatment of pembrolizumab plus eribulin in breast cancer. This signature has the potential to serve as a valuable tool for patients in selecting appropriate immunotherapy treatments.

Patient-reported outcome and survival in premenopausal hormone receptor-positive breast cancer patients at moderate to high risk: comparing toremifene with aromatase inhibitor in a real-world study.

Toremifene, a selective estrogen receptor modulator, is commonly used in China for premenopausal breast cancer patients. This real-world study aimed to compare patient-reported outcome (PRO) and survival between toremifene and aromatase inhibitor (AI) plus ovarian function suppression (OFS) in patients with moderate-/high-risk premenopausal hormone receptor (HR)-positive breast cancer. The primary endpoint was PROs, assessed using SF-36 and EQ-5D-5L questionnaires between January and March 2023. A total of 392 patients were included, with 171 receiving toremifene and 221 receiving AI. The toremifene group showed significantly higher scores in the role physical (p=0.034) and mental health (p=0.009) dimensions of SF-36 and lower anxiety/depression (AD) scores (p=0.038) in EQ-5D-5L compared to AI group. The estimated 5- and 8-year disease-free survival (DFS) rates were similar in toremifene and AI groups: 96.5% versus 91.9%, and 87.4% versus 87.8% (p=0.39), respectively. Adverse event rates were similar in two groups, except for a greater risk of endometrial thickening (p<0.001) and a lower occurrence of morning stiffness (p<0.001) in the toremifene compared to the AI group. Premenopausal HR-positive breast cancer patients receiving toremifene plus OFS had better role physical and mental health outcomes and lower AD dimensions than those receiving AI plus OFS. Both treatments had comparable DFS and favorable tolerability profiles.

Risk Coping Strategies among Chinese Breast Cancer Survivors: A Qualitative Study

Breast cancer (BC) is intricately linked with emotions, underscoring the importance of BC survivors adopting effective coping strategies. This study utilized qualitative research methods and semi-structured interviews to explore the evolving coping strategies of 15 Chinese BC survivors throughout their recovery journey. Through the process of coding and organizing the interview data, it was found that individuals frequently shifted from employing negative coping strategies to employing active coping strategies when faced with risk. The transformation approaches include from ineffective emotional venting to positive reappraisal; from focused on thought/rumination to avoidance; from putting into perspective to positive focusing; from other blame to positive refocusing; identifying and cleaning up irrational emotions; self-awareness growth. Furthermore, three coping strategies emerged: emotion-focused coping; problem-focused coping; and meaning-focused coping. Each coping strategy offers unique strengths and appropriate situations. The findings underscore the importance of fostering a positive outlook on risks among BC survivors and continuously enhancing their coping skills to navigate the challenges they encounter.

Latent Profiles of Fear of Cancer Recurrence in Breast Cancer Patients of Reproductive Age and Associations With Reproductive Concerns.

To identify distinct profiles of fear of cancer recurrence (FCR) among breast cancer patients of reproductive age, investigate the relationship between these profiles and reproductive concerns and explore potential risk factors encompassing sociodemographic, clinical and reproductive characteristics. A cross-sectional study was conducted from January 2022 to September 2022. A convenience sample of 210 reproductive-aged breast cancer patients completed a questionnaire that included a general information section, the Fear of Progression Questionnaire-Short Form (FoP-Q-SF) and the Reproductive Concerns After Cancer Scale (RCAC). Latent profile analysis was conducted using the scores of the 12 items from the FoP-Q-SF as explicit variables, while univariate and multiple logistic regression analyses were employed for statistical analysis. Three latent variables were identified: low FCR-stable group (27.6%), moderate FCR-uneasy group (17.2%) and high FCR-intense group (55.2%). This study found that FCR was predicted by age, education level, cancer stage, chemotherapy and fertility intention. Furthermore, patients with heightened reproductive concerns exhibited a higher likelihood of belonging to the high FCR-intense group. These findings indicate that FCR varies among breast cancer patients of reproductive age and demonstrates individual differences. Early identification of FCR patterns in patients is crucial for medical professionals, with particular attention given to those in the high-intensity FCR group. Tailored prevention and care strategies should be implemented based on the unique characteristics and influencing factors associated with different potential categories of FCR among patients of childbearing age with breast cancer. No patient or public contribution.

Abstract A031: Identification of therapeutic vulnerabilities in the subset of pancreatic ductal adenocarcinoma (PDAC) with homologous recombination deficiency

Abstract The genetic landscape of pancreatic ductal adenocarcinoma (PDAC) is characterized by mutations in the KRAS, TP53, CDKN2A and SMAD4 genes alongside multiple low-frequency mutations, which may offer opportunities for precision medicine. The success of poly-ADP-ribose polymerase (PARP) inhibitors in metastatic PDAC characterized by germline mutations in the Breast Cancer (BRCA) genes has led to the hypothesis that mutations in other BRCAness genes may sensitize PDAC to PARP inhibitors. To test this hypothesis, we used KPC mice as a backbone (Pdx1-Cre; LSL-KrasG12D/+; LSL-Trp53R172H/+) to generate models of PDAC driven by the loss of Ataxia Telangiectasia mutated (Atm, KPCA) or Brca1 (KPCB). Loss of Atm or Brca1 resulted in homologous recombination deficiency and genomic instability in vivo. In vitro cultures of KPCA and KPCB PDAC cells had higher numbers of micronuclei and were more radiosensitive than KPC cells. Next, we performed bulk and single-cell RNA sequencing to identify therapeutic vulnerabilities associated with Atm or Brca1 loss. We found that loss of Atm upregulated ATR signaling, suggesting ATR as a therapeutic target in KPCA mice. In agreement, ATR inhibition improved the survival of KPCA mice, with evidence of tumor growth delay. However, though PARP inhibition significantly improved the survival of KPCB mice, with delayed tumor growth, it was ineffective in KPCA mice. In addition, transcriptomic analysis showed an enrichment of immune cells in KPCB PDAC compared to KPC and KPCA PDAC. Notably, we found greater levels of STING signaling, a more diverse and abundant cytokine profile and more CD8 T cells in KPCB PDAC, suggesting sensitivity to immune checkpoint blockade (ICB). However, ICB was ineffective in KPCB mice as a single agent or in combination with PARP inhibition. Based on our transcriptomic data, we hypothesized that boosting antigen priming using a CD40 agonist (CD40a) in combination with FLT3-L may improve ICB efficacy in our mouse models of BRCAness. Immunotherapy consisting of combined ICB, CD40a and FLT-3L had little efficacy in either KPCA or KPCB mice. However, ATR inhibition improved the efficacy of combined ICB, CD40a and FLT-3L in KPCA mice, as indicated by increased CD8 T cell infiltration in the tumor, delayed tumor growth and longer survival. In contrast, we found that PARP inhibition combined with ICB, CD40a and FLT-3L was ineffective in KPCB mice. In summary, we present evidence to suggest that PDAC characterized by BRCAness is not a homogeneous group with respect to sensitivity to PARP inhibition, composition of the tumor microenvironment and response to immunotherapy. We highlight ATM loss as a potential predictive biomarker of ATR inhibitor efficacy and immunotherapy in PDAC. Future directions include the evaluation of inflammation as a therapeutic vulnerability in murine PDAC with loss of Brca1. Ultimately, we aim to inform clinical trials to refine precision medicine of PDAC characterized by BRCAness. Citation Format: Mathias Tesson, Kay Kong, Peter Repsicak, Aldo Bader, Ya-Ching Hsieh, Craig Nourse, Kristina Kirschner, Crispin Miller, Ed Roberts, David Chang, Jen Morton. Identification of therapeutic vulnerabilities in the subset of pancreatic ductal adenocarcinoma (PDAC) with homologous recombination deficiency [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A031.

Abstract C006: LODESTAR: A Single Arm Phase II Study of Rucaparib in Solid Tumors with Pathogenic Germline or Somatic Variants in Homologous Recombination Repair (HRR) Genes

Abstract Purpose: Poly (ADP-ribose) polymerase inhibitors (PARPi) have proven clinical utility in platinum-sensitive breast, ovary, pancreas, and prostate cancers with homologous recombination deficiency (HRD). We explored whether PARPi might be efficacious in other solid tumors and for a broader range of genomic variants. Patients and Methods: This single-arm phase II study assessed rucaparib monotherapy in patients with advanced, platinum-sensitive or -resistant solid tumors and pathogenic variants (PVs) in BRCA1, BRCA2, PALB2, RAD51C, RAD51D (Cohort A) or BARD1, BRIP1, FANCA, NBN, RAD51B (Cohort B). The primary endpoint was overall response rate (ORR) in cohort A. Secondary endpoints included disease control rate (DCR), progression free survival (PFS), overall survival (OS) and safety[SS3] [SA4] in the entire study population. Available tumors were analyzed for pre-specified exploratory objective of allele specific loss of heterozygosity (LOH). [SA7] HRD signature (HRDsig) and platinum sensitivity status were explored as biomarkers for rucaparib activity in post hoc exploratory analyses. The study was terminated early by the sponsor due to feasibility concerns. Results: Eighty-three patients were enrolled (Cohort A: 63; Cohort B: 20). Fifty-seven patients in Cohort A and 16 in Cohort B were evaluable for efficacy analysis. The[LM8] [SA9] ORR of cohort A was 16% (95% CI 9-27%) and DCR was 61% (95% CI 48-73%). LOH and HRDsig were available for 48% of Cohort A and 71% of Cohort B. Of 11 patients who had a response to treatment, 6 tumors were HRDsig+, 1 HRDsig-and 4 were unknown. The ORR and DCR were significantly greater in patients with HRDsig+ vs HRDsig-tumors (ORR: HRDsig+ 32% [95% CI 15-54%] vs HRDsig-3% [95% CI 0-15%], p &amp;lt; 0.01; DCR: HRDsig+ 74% [95% CI 51-88%] vs HRDsig-38% [95% CI 24-55%], p = 0.02). mPFS was numerically longer for HRDsig+ vs HRDsig-: 7.0 mos (95% CI, 4.3 – inf), vs. 3.0 mos (95% CI 2.3-5.6), HR 0.57, p = 0.14. mPFS was greater for platinum sensitive vs resistant tumors (7.82 mos [95% CI 5.5-inf] vs. 2.9 mos [95% CI 1.8-inf], HR 0.28, p = 0.02); Neither tumor tissue of origin nor specific mutation was independently predictive of outcome. The HR for progression in tumors that were both HRDsig+ and platinum sensitive versus those that were HRDsig-and platinum resistant was 0.09 (95% CI 0.01-0.55, p = 0.047). The Rucaparib safety profile was consistent with prior studies. Conclusion: Rucaparib has activity across solid tumors with PVs in HRR genes, regardless of tissue of origin. Patients with platinum resistant or HRDsig-tumors had limited clinical benefit from rucaparib. The combined use of HRDsig and platinum sensitivity to predict sensitivity to PARPi is encouraging as a biomarker strategy and warrants prospective study. Citation Format: Sriram Anbil, Nicholas J Seewald, Kevin Lin, Marcia Craib, Christy Connor, Heidi Giordano, Karen McLachlan, Tanya Kwan, Lara Maloney, Hanna Tukachinsky, Alexa Schrock, Shuoguo Wang, Ethan Sokol, Brennan Decker, Katherine Nathanson, Susan Domchek, Kim Reiss. LODESTAR: A Single Arm Phase II Study of Rucaparib in Solid Tumors with Pathogenic Germline or Somatic Variants in Homologous Recombination Repair (HRR) Genes [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C006.

Abstract A085: Engineered novel bioactive Nectin-4 dimer protein significantly enhances the binding of TIGIT

Abstract The goals of this study are to: (a) create a novel soluble bioactive Nectin-4 dimer molecule mimicking its native dimer quaternary structure on the cell surface and (b) evaluate the recombinant Nectin-4 dimer binding potency to its receptor vs the monomer form, so that the dimer can be used as an immunogen and an antigen to increase the potential of cancer therapeutic antibody and vaccine discovery when targeting quaternary structural epitopes. Nectin-4 is a cell adhesion molecule belonging to the nectin family. It's involved in cell-cell junctions and plays a role in cancer progression by influencing cell adhesion, migration, and proliferation. Nectin-4 is overexpressed on various types of tumor cells including breast, lung, ovarian and pancreatic cancers. Nectin-4 has been recently identified as a novel ligand of T cell immunoglobulin and ITIM domain (TIGIT) and interaction between Nectin-4 and TIGIT inhibits NK cell cytotoxicity thus suppressing immune responses, allowing cancer cells to evade immune surveillance. Nectin-4 and Nectin-1 interact in a heterophilic manner, however in the context of cancer, altered expression of Nectin-4 and Nectin-1 can contribute to tumor progression. Nectin-4 is a type 1 single transmembrane protein, and can form homodimers on the cell surface. While therapeutics such as Enfortumab Vedotin, an antibody-drug conjugate, binds Nectin-4 on the surface of cancer cells, mimicking the Nectin-4 dimer quaternary structure can present many more critical opportunities for therapeutic antibody and vaccine discovery. To better mimic the native dimer conformation and quaternary structure, we designed a novel soluble Nectin-4 dimer with 3 extracellular domains fused to a dimer motif at the C-terminus. The Nectin-4 dimer protein was expressed and purified from HEK293 cells and confirmed by SDS-PAGE and Western blot analyses. We characterized the Nectin-4 dimer protein binding potency to TIGIT and Nectin-1 by ELISA. Very interestingly, the results demonstrated that the Nectin-4 dimer binding potency to TIGIT increased dramatically as measured by ELISA, compared to the Nectin-4 monomer protein. Conversely, the Nectin-4 dimer binding to Nectin-1 monomer was significantly decreased, compared to Nectin-4 monomer, as expected. We also studied Nectin-4 dimer immunogenicity using a Nectin-4 dimer DNA immunization to induce potent antibody responses in mice. In summary, these findings imply that the Nectin-4 dimer protein is bioactive and in the desirable conformation, resulting in an increased binding potency to its receptor TIGIT, reduced binding to Nectin-1 (as expected), and eliciting strong antibody responses in mice. This novel Nectin-4 dimer protein can be a very useful molecule for cancer research, therapeutic antibody and vaccine discovery. The Nectin-4 dimer protein can be used to: (i) elicit antibody responses against the dimer quaternary structure, (ii) screen antibodies targeting more conformational epitopes, and (iii) study the Nectin-4 and TIGIT ligand/receptor interactions. Citation Format: Christofer Walsh, Timothy Smith, Mikhail Rashkovskii, Richard Parent, Jean Qiu, Shixia Wang. Engineered novel bioactive Nectin-4 dimer protein significantly enhances the binding of TIGIT [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A085.

Prognostic determinants in cancer survival: a multidimensional evaluation of clinical and genetic factors across 10 cancer types in the participants of Genomics England’s 100,000 Genomes Project

BackgroundCancer is a complex disease, caused and impacted by a combination of genetic, demographic, clinical, environmental and lifestyle factors. Analysis of cancer characteristics, risk factors, treatment options and the heterogeneity across cancer types has been the focus of medical research for years. The aim of this study is to describe and summarise genetic, clinicopathological, behavioural and demographic characteristics and their differences across ten common cancer types and evaluate their impact on overall survival outcomes.MethodsThis study included data from 9977 patients with bladder, breast, colorectal, endometrial, glioma, leukaemia, lung, ovarian, prostate, and renal cancers. Genetic data collected through the 100,000 Genomes Project was linked with clinical and demographic data provided by the National Cancer Registration and Analysis Service (NCRAS), Hospital Episode Statistics (HES) and Office for National Statistics (ONS). Descriptive and Kaplan Meier survival analyses were performed to visualise similarities and differences across cancer types. Cox proportional hazards regression models were applied to identify statistically significant prognostic factor associations with overall survival.Results161 clinical and 124 genetic factors were evaluated for prognostic association with overall survival. Of these, 116 unique factors were found to have significant prognostic effect for overall survival across ten cancer types when adjusted for age, sex and stage. The findings confirmed prognostic associations with overall survival identified in previous studies in factors such as multimorbidity, tumour mutational burden, and mutations in genes BRAF, CDH1, NF1, NRAS, PIK3CA, PTEN, TP53. The results also identified new prognostic associations with overall survival in factors such as mental health conditions, female health-related conditions, previous hospital encounters and mutations in genes FANCE, FBXW7, GATA3, MSH6, PTPN11, RB1, RNF43.ConclusionThis study provides a comprehensive view of clinicopathological and genetic prognostic factors across different cancer types and draws attention to less commonly known factors which might help produce more precise prognosis and survival estimates. The results from this study contribute to the understanding of cancer disease and could be used by researchers to develop complex prognostic models, which in turn could help predict cancer prognosis more accurately and improve patient outcomes.

Protein tyrosine phosphatase non-receptor II: A possible biomarker of poor prognosis and mediator of immune evasion in hepatocellular carcinoma

BACKGROUND The incidence of primary liver cancer is increasing year by year. In 2022 alone, more than 900000 people were diagnosed with liver cancer worldwide, with hepatocellular carcinoma (HCC) accounting for 75%-85% of cases. HCC is the most common primary liver cancer. China has the highest incidence and mortality rate of HCC in the world, and it is one of the malignant tumors that seriously threaten the health of Chinese people. The onset of liver cancer is occult, the early cases lack typical clinical symptoms, and most of the patients are already in the middle and late stage when diagnosed. Therefore, it is very important to find new markers for the early detection and diagnosis of liver cancer, improve the therapeutic effect, and improve the prognosis of patients. Protein tyrosine phosphatase non-receptor 2 (PTPN2) has been shown to be associated with colorectal cancer, triple-negative breast cancer, non-small cell lung cancer, and prostate cancer, but its biological role and function in tumors remain to be further studied. AIM To combine the results of relevant data obtained from The Cancer Genome Atlas (TCGA) to provide the first in-depth analysis of the biological role of PTPN2 in HCC. METHODS The expression of PTPN2 in HCC was first analyzed based on the TCGA database, and the findings were then verified by immunohistochemical staining, quantitative real-time polymerase chain reaction (qRT-PCR), and immunoblotting. The value of PTPN2 in predicting the survival of patients with HCC was assessed by analyzing the relationship between PTPN2 expression in HCC tissues and clinicopathological features. Finally, the potential of PTPN2 affecting immune escape of liver cancer was evaluated by tumor immune dysfunction and exclusion and immunohistochemical staining. RESULTS The results of immunohistochemical staining, qRT-PCR, and immunoblotting in combination with TCGA database analysis showed that PTPN2 was highly expressed and associated with a poor prognosis in HCC patients. Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that PTPN2 was associated with various pathways, including cancer-related pathways, the Notch signaling pathway, and the MAPK signaling pathway. Gene Set Enrichment Analysis showed that PTPN2 was highly expressed in various immune-related pathways, such as the epithelial mesenchymal transition process. A risk model score based on PTPN2 showed that immune escape was significantly enhanced in the high-risk group compared with the low-risk group. CONCLUSION This study investigated PTPN2 from multiple biological perspectives, revealing that PTPN2 can function as a biomarker of poor prognosis and mediate immune evasion in HCC.