Poor Overall Survival In Patients Research Articles

Psoas mass index at the level of the third lumbar vertebra on computed tomography is a prognostic predictor for metastatic castration-sensitive prostate cancer.

Computed tomography-defined low skeletal muscle mass is associated with oncological outcomes in patients with prostate cancer. However, its association with the outcomes of hormone-treated metastatic castration-sensitive prostate cancer remains unclear. We aimed to determine the association between metastatic castration-sensitive prostate cancer and psoas muscle parameters. We retrospectively reviewed 121 patients with N1 and/or M1 metastatic castration-sensitive prostate cancer who underwent primary androgen deprivation therapy between 2005 and 2021, either by administration of luteinizing hormone-releasing hormone agonist/antagonist or by surgical castration accompanied by bicalutamide, a first-generation antiandrogen. Before treatment administration, the psoas muscle index at the level of the third lumbar vertebra (psoas muscle area [cm2]/height2 [m2]) and the mean Hounsfield units of the psoas muscle were evaluated using non-contrast computed tomography and in relation to oncological outcomes. The median follow-up was 56.9months. Furthermore, during follow-up, 82 (67.7%) and 53 (43.8%) patients progressed to castration-resistant prostate cancer and died, respectively. Multivariate analysis of castration-resistant prostate cancer-free survival and overall survival showed significant differences in the Gleason score, clinical N-stage, and psoas muscle index (median cutoff: 3.044 cm2/m2). Pretreatment psoas muscle index is an independent predictor of poor castration-resistant prostate cancer-free survival and overall survival in patients with N1 and/or M1 metastatic castration-sensitive prostate cancer.

Prognostic and clinicopathological value of systemic inflammation response index (SIRI) in patients with breast cancer: a meta-analysis

Background Many studies have explored the value of the systemic inflammation response index (SIRI) in predicting the prognosis of patients with breast cancer (BC); however, their findings remain controversial. Consequently, we performed the present meta-analysis to accurately identify the role of SIRI in predicting BC prognosis. Methods PubMed, Embase, Cochrane Library, and Web of Science databases were comprehensively searched between their inception and February 10, 2024. The significance of SIRI in predicting overall survival (OS) and disease-free survival (DFS) in BC patients was analyzed by calculating pooled hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). Results Eight articles involving 2,997 patients with BC were enrolled in the present study. According to our combined analysis, a higher SIRI was markedly associated with dismal OS (HR = 2.43, 95%CI = 1.42–4.15, p < 0.001) but not poor DFS (HR = 2.59, 95%CI = 0.81–8.24, p = 0.107) in patients with BC. Moreover, based on the pooled results, a high SIRI was significantly related to T3–T4 stage (OR = 1.73, 95%CI = 1.40–2.14, p < 0.001), N1–N3 stage (OR = 1.61, 95%CI = 1.37–1.91, p < 0.001), TNM stage III (OR = 1.63, 95%CI = 1.34–1.98, p < 0.001), and poor differentiation (OR = 1.25, 95%CI = 1.02–1.52, p = 0.028). Conclusion According to our results, a high SIRI significantly predicted poor OS in patients with BC. Furthermore, elevated SIRI was also remarkably related to increased tumor size and later BC tumor stage. The SIRI can serve as a novel prognostic biomarker for patients with BC.

LncRNA RGMB-AS1 inhibits HMOX1 ubiquitination and NAA10 activation to induce ferroptosis in non-small cell lung cancer

Ferroptosis, an iron-dependent regulated cell death caused by excessive lipid peroxide accumulation, has emerged as a promising therapeutic target in various cancers, including non-small cell lung cancer (NSCLC). In this study, we identified the long non-coding RNA RGMB-AS1 as a key regulator of ferroptosis in NSCLC. Mechanistically, RGMB-AS1 interacted with heme oxygenase 1 (HMOX1) and prevented its ubiquitination by the E3 ligase TRC8, leading to increased HMOX1 stability and enhanced ferroptosis. Additionally, RGMB-AS1 bound to the 82–87 amino acid region of N-alpha-acetyltransferase 10 (NAA10), stimulating its acetyltransferase activity and promoting the conversion of acetyl-CoA to HMG-CoA, further contributing to ferroptosis. The RGMB-AS1-HMOX1 and RGMB-AS1-NAA10 axes synergistically inhibited NSCLC growth both in vitro and in vivo. Clinically, low RGMB-AS1 expression was associated with advanced tumor stage and poor overall survival in NSCLC patients. Furthermore, adeno-associated virus-mediated RGMB-AS1 overexpression significantly suppressed tumor growth in mouse xenograft models. Our findings uncover a novel lncRNA-mediated regulatory mechanism of ferroptosis and highlight the potential of RGMB-AS1 as a prognostic biomarker and therapeutic target in NSCLC.

E2F-mediated POLA2 upregulation is correlated with macrophage infiltration and poor prognosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the major histological type of primary liver cancer with a relatively poor prognosis, because most HCC cases are usually diagnosed at an advanced stage. Thus, it is essential to explore novel candidate biomarkers for early diagnosis and prognosis predication of HCC. HCC transcription sequencing data were downloaded and analyzed. POLA2 expression pattern was characterized in tumor development process. POLA2 expression was evaluated by western blotting. Kaplan-Meier plot was utilized to evaluate POLA2's ability for prognosis predication. Correlation analysis and enrichment analysis were performed to explore the functional role of POLA2 in HCC development. Knockdown of E2F1 or E2F4 was used to evaluate their ability in regulating POLA2 expression. CYBERSORT (https://cibersortx.stanford.edu/) was used to estimate the infiltration levels of immune cells. POLA2 was overexpressed in HCC. Moreover, western blotting results showed that POLA2 was upregulated by transcription factors E2F1 rather than E2F4 in HCC. POLA2 facilitated cell cycle progression, DNA replication and DNA repair. High POLA2 expression was correlated with poor overall survival in HCC patients. POLA2 induced macrophage infiltration in the tumor microenvironment by upregulating the expression CSF1 and VEGFA expression. POLA2 is a novel diagnostic and prognostic biomarker of HCC with potential clinical value.

MIR145 Core Promoter Methylation in Pretreatment Cell-Free DNA: A Liquid Biopsy Tool for Muscle-Invasive Bladder Cancer Treatment Outcome.

The lack of personalized management of bladder cancer (BlCa) results in patients' lifelong post-treatment monitoring with invasive interventions, underlying the urgent need for tailored and minimally invasive health care services. On the basis of our previous findings on miR-143/145 cluster methylation in bladder tumors, we evaluated its clinical significance in pretreatment cell-free DNA (cfDNA) of patients with BlCa. Methylation analysis was performed in our screening cohort (120 patients with BlCa; 20 age-matched healthy donors) by bisulfite-based pyrosequencing. Tumor recurrence/progression for patients with non-muscle-invasive bladder cancer, and progression and mortality for patients with muscle-invasive bladder cancer (MIBC) were used as clinical end point events in survival analysis. Bootstrap analysis was applied for internal validation of Cox regression models and decision curve analysis for assessment of clinical benefit on disease prognosis. Decreased methylation of MIR145 core promoter in pretreatment cfDNA was associated with short-term disease progression (multivariate Cox: hazard ratio [HR], 2.027 [95% CI, 1.157 to 3.551]; P = .010) and poor overall survival (multivariate Cox: HR, 2.098 [95% CI, 1.154 to 3.817]; P = .009) of patients with MIBC after radical cystectomy (RC). Multivariate models incorporating MIR145 promoter methylation in cfDNA with tumor stage clearly ameliorated patients' risk stratification, highlighting superior clinical benefit in MIBC prognostication. Reduced pretreatment cfDNA methylation of MIR145 core promoter was markedly correlated with increased risk for short-term progression and worse survival of patients with MIBC after RC and adjuvant therapy, supporting modern personalized and minimally invasive prognosis. Methylation profiling of MIR145 core promoter in pretreatment cfDNA could serve as a minimally invasive and independent predictor of MIBC treatment outcome and emerge as a promising marker for blood-based test in BlCa.

RBM39 is a potential prognostic biomarker with functional significance in hepatocellular carcinoma.

RNA-binding motif protein 39 (RBM39) is a well-known RNA-binding protein involved in tumorigenesis; however, its role in hepatocellular carcinoma (HCC) remains unclear. The aim of this study was to investigate the role of RBM39 in HCC. The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were used to analyze the differential expression of RBM39 in HCC and normal tissues. The prognostic and diagnostic value of RBM39 in HCC was accessed by Kaplan-Meier analysis, Cox regression, and receiver operating characteristic (ROC) curve analyses. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry were used to validate the mRNA and protein expression of RBM39 in HCC. Moreover, gene set enrichment analysis (GSEA) was performed to identify key pathways related to RBM39. The correlation between RBM39 expression and immune cell infiltration was evaluated using a single-sample gene set enrichment analysis (ssGSEA). CCK8 and wound healing assays were performed to investigate the proliferation and migration abilities of HCC cells with RBM39 knockdown. RBM39 expression was upregulated in the HCC tissues. High RBM39 expression was significantly associated with advanced T stage, histological grade, and pathological stage and predicted poor overall survival (OS), disease-specific survival (DSS), and progress-free interval (PFI) in HCC patients. The upregulation of RBM39 expression was an independent prognostic factor for OS. Moreover, GSEA enrichment analysis indicated that RBM39 was functionally involved in pathways associated with the cell cycle, DNA replication, the p53 signaling pathway, and primary immunodeficiency. RBM39 expression was associated with infiltration of Th2 cells and dendritic cells (DC). RBM39 knockdown significantly inhibited the proliferation and migration of HCC cells. These findings suggest that high RBM39 expression is associated with poor prognosis and promotes HCC cell proliferation and migration. Based on these results, RBM39 is a promising prognostic biomarker with functional significance for HCC.

Targeting the KAT8/YEATS4 Axis Represses Tumor Growth and Increases Cisplatin Sensitivity in Bladder Cancer.

Bladder cancer (BC) is one of the most common tumors characterized by a high rate of relapse and a lack of targeted therapy. Here, YEATS domain-containing protein 4 (YEATS4) is an essential gene for BC cell viability using CRISPR-Cas9 library screening is reported, and that HUWE1 is an E3 ligase responsible for YEATS4 ubiquitination and proteasomal degradation by the Protein Stability Regulators Screening Assay. KAT8-mediated acetylation of YEATS4 impaired its interaction with HUWE1 and consequently prevented its ubiquitination and degradation. The protein levels of YEATS4 and KAT8 are positively correlated and high levels of these two proteins are associated with poor overall survival in BC patients. Importantly, suppression of YEATS4 acetylation with the KAT8 inhibitor MG149 decreased YEATS4 acetylation, reduced cell viability, and sensitized BC cells to cisplatin treatment. The findings reveal a critical role of the KAT8/YEATS4 axis in both tumor growth and cisplatin sensitivity in BC cells, potentially generating a novel therapeutic strategy for BC patients.

Dipeptidyl-peptidase 9 regulates the dynamics of tumorigenesis and metastasis in breast cancer

The cytosolic dipeptidyl-aminopeptidase 9 (DPP9) cleaves protein N-termini post-proline or -alanine. Our analysis of DPP9 mRNA expression from the TCGA ‘breast cancer’ data set revealed that low/intermediate DPP9 levels are associated with poor overall survival of breast cancer patients. To unravel the impact of DPP9 on breast cancer development and progression, the transgenic MMTV-PyMT mouse model of metastasizing breast cancer was used. In addition, tissue- and time-controlled genetic deletion of DPP9 by the Cre-loxP recombination system was done. Despite a delay of tumor onset, a higher number of lung metastases were measured in DPP9-deficient mice compared to controls. In human mammary epithelial cells with oncogenic RAS pathway activation, DPP9 deficiency delayed tumorigenic transformation and accelerated TGF-β1 induced epithelial-to-mesenchymal transition (EMT) of spheroids. For further analysis of the mechanism, primary breast tumor cells were isolated from the MMTV-PyMT model. DPP9 deficiency in these cells caused cancer cell migration and invasion accompanied by EMT. In absence of DPP9, the EMT transcription factor ZEB1 was stabilized due to insufficient degradation by the proteasome. In summary, low expression of DPP9 appears to decelerate mammary tumorigenesis but favors EMT and metastasis, which establishes DPP9 as a novel dynamic regulator of breast cancer initiation and progression.

Abstract 2027: Serological assessment of cancer associated myo-fibroblast (myCAF) activity by collagen pro-peptide biomarkers provides high prognostic power

Abstract Background: Myofibroblast Cancer Associated Fibroblasts (myCAFs) are the main tumor fibrosis drivers and hence different from inflammatory CAFs (iCAFs). MyCAFs are emerging as an important tool for understanding tumor biology. CAFs produce type III, V, VI and XI collagen that are the essential components of tumor fibrosis. Pro-peptides of these collagens can be quantified both in serum with the PRO-C3, PRO-C5, PRO-C6 and PRO-C11 biomarkers where they are prognostic for poor overall survival in patients with various solid tumor types and may be applied in vitro. Here we investigated the association and difference between myCAFs and iCAFs and their collagen expression profile and related that to data available data on serological assessments of PRO-C3, PRO-C5, PRO-C6 and PRO-C11, and cultured CAFs. Methods: The collagen expression in CAF subtypes were established from publicly available single-cell RNA-Seq dataset from pancreas cancer (PMID: 31273297) and non-small cell lung cancer (PMID: 36973297). In addition, we generated a biomarker profile using PRO-C3, PRO-C5, PRO-C6 and PRO-C11 ELISA to measure in serum of 220 patients with various solid tumor types and 33 healthy controls. We cultured CAFs in vitro and measured the same biomarkers in conditioned medium. We compared the result to historical PRO-C3, PRO-C6 and PRO-C11 prognostic data for pancreas cancer patient data. Results: Based on the single-cell RNA-Seq dataset, while type III and type VI collagen were found expressed in fibroblasts both from normal tissues and tumor tissues whereas type V collagen and XI collagen were found almost exclusively expressed in CAFs (tumor tissue). When further examining the CAF subtypes, type III collagen and VI collagen were found expressed in both myCAFs and iCAFs whereas type V collagen and XI collagen were found almost exclusively expressed in myCAFs and not iCAFs. Moreover, in the 220 patients, PRO-C3 and PRO-C6 was elevated in elevated in a few cancer types (p&amp;lt;0.05-0.01) with an inter-patient variation ~2-fold whereas PRO-C5 and PRO-C11 were elevated in all cancer types (p&amp;lt;0.0001) with a ~5-fold inter-patient variation. These four biomarkers identified different pancreas cancer patients endotypes all with poor overall survival, P&amp;lt;0.001. In direct alignment, collagen pro-peptides we highly upregulated in cultures of CAFs. Conclusions: Profiling collagen expression in fibroblast from PDAC and NSCLC reveals that type V collagen and type XI collagen are exclusively found in myCAF not iCAF. Biomarkers of these collagens can be measured in serum from cancer patients and are prognostic for poor overall survival. Thus, these data suggest that cancer associated myo-fibroblast (myCAF) activity can be assessed non-invasively by specific collagen pro-peptide biomarkers. Citation Format: Nicholas Willumsen, Neel I. Nissen, Morten A. Karsdal. Serological assessment of cancer associated myo-fibroblast (myCAF) activity by collagen pro-peptide biomarkers provides high prognostic power [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 2027.

Abstract 1155: Spatial colocalization and molecular crosstalk of myofibroblastic CAFs and tumor cells shape lymph node metastasis in oral squamous cell carcinoma

Abstract Lymph node metastasis (LNM) is a critical prognostic factor for patients with oral squamous cell carcinoma (OSCC). While previous research has implicated partial epithelial-to-mesenchymal transition (p-EMT) of tumor cells and cancer-associated fibroblasts (CAFs), specifically myofibroblastic CAFs (myCAFs), in LNM, the underlying molecular mechanisms remain poorly understood. Furthermore, the lack of diagnostic and prognostic biomarkers related to LNM has impeded the improvement in clinical outcomes for patients with OSCC. Here, we conducted a comprehensive molecular analysis integrating original and publicly available OSCC data of the bulk genome and transcriptome analyses, single-cell transcriptome profiling, and spatial transcriptome analyses. We found that myCAFs were both quantitatively and functionally activated in LNM-positive samples and spatially colocalized with OSCC cells within the invasive tumor front (ITF), providing a niche that may facilitate LNM. We validated spatial colocalization of myCAFs and OSCC cells using 50 additional Immunohistochemistry (IHC) samples. Mechanistically, myCAFs provided increased extracellular matrix (ECM) signals, such as COLLAGEN, Fibronectin1(FN1), and LAMININ to OSCC cells. Consequently, OSCC cells upregulate ECM receptors such as αβ integrins (ITGA-B), syndecans (SDC), and CD44, leading to upregulating stemness-related genes in OSCC cells. Further analysis using CRISPRGeneEffect data from DepMap found that ITGB1, ITGA3, and CD44 are among the most essential genes for the survival and growth of OSCC cells. By analyzing the spatial transcriptomic data of matched primary tumor sites (HUH001-P1 and HUH001-P2) and metastatic site (HUH001-met) from the same patient, we identified the origins of metastatic cells in the primary tumor site. We further extracted a 23-gene signature from the metastatic origin in ITF, where OSCC and myCAFs colocalize. This spatially-resolved 23-gene signature predicted LNM status and poor overall survival (OS) in clinical OSCC patients. The prognostic significance of the 23-gene signature we extracted from the spatial analysis was also validated in separate clinical cohorts from TCGA study and two other microarray datasets. Our findings provide novel insight into the molecular crosstalk between myCAFs and OSCC cells that facilitates LNM and identifies clinically valuable biomarkers for better prognostication in patients with OSCC. Citation Format: Ken Furudate, Shuya Kasai, Tadashi Yoshizawa, Yuya Sasaki, Kohei Fujikura, Shintaro Goto, Ryohei Ito, Tomoyuki Tanaka, Hiroshi Kijima, Kosei Kubota, Ken Itoh, Wataru Kobayashi, Koichi Takahashi. Spatial colocalization and molecular crosstalk of myofibroblastic CAFs and tumor cells shape lymph node metastasis in oral squamous cell 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 1155.

Abstract 5978: Therapeutic targeting of MELK using a drug repurposing approach to combat TNBC cells

Abstract Background: Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer linked to high chemo-resistant metastatic cases and limited therapeutic options due to the absence of conventional bioreceptors. Therefore, to treat TNBC, it is imperative to identify promising druggable biological targets. Experimental Procedures: An integrated bioinformatic analysis of microarray datasets was performed to identify significantly differentially expressed genes (DEGs) in TNBC. For selecting a potent therapeutic target, the function and significance of the upregulated DEGs in TNBC was investigated by an in silico study employing the UALCAN portal, String database, KM plotter, and Enrichr tools. This analysis included gene expression validation, insights into protein-protein interactions, survival analysis, and pathway mapping of the genes. To obtain potent drugs binding to the selected target MELK (maternal embryonic leucine zipper kinase), a drug repurposing approach was employed starting with virtual screening followed by molecular dynamic simulation (MDS) using GROMACS. Further, the anti-cancer activity of the top two drugs was validated by live-dead imaging, gene expression analyses, MTT-based cell viability and ROS detection assays. Results: Based on a stringent criterion for significant DEG identification (log2|FC|&amp;gt;1 &amp; adjust P-value &amp;lt; 0.05), 25 overlapping upregulated genes were obtained from three selected datasets. Further, in silico analysis revealed that MELK is significantly upregulated across the four stages and subtypes of breast cancer, including TNBC. Higher MELK expression and its oncogenic interactions correlated with poor overall survival of TNBC patients. Evidence suggests that the existing inhibitor for MELK (OTSSP167) has shown poor specificity. Therefore, to block its activity, a library of 1293 FDA-approved drugs was screened against the kinase domain of MELK. MDS study and analysis using parameters like RMSD, RMSF and pair distance revealed that the top 10 drugs were strongly stabilized by H-bonds in the binding pocket of MELK, with minimal deviation and reduced fluctuations of MELK upon drug binding. Binding free energy calculation of drug-MELK interaction using the MM-PBSA method revealed that nine drugs possessed higher binding energy than the inhibitor. The top two drugs obtained from the study (originally kinase and reductase inhibitors respectively) were further validated for their in vitro anti-cancer efficacy in MDA-MB-231 and MDA-MB-468 cells. Treatment with these drugs exhibited (a) a dose-dependent decrease in proliferation, (b) significant cell death, (c) a marked increase in the cellular ROS levels, and (d) a decrease in the expression of MELK and its downstream targets in TNBC cell lines. Conclusion: The present study opens the avenue for using repurposed drugs as potential therapeutic molecules against MELK activity to combat TNBC progression. Citation Format: Arisha Arora, Shilpi Sarkar, Siddhartha S. Ghosh. Therapeutic targeting of MELK using a drug repurposing approach to combat TNBC 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 5978.

Abstract 3130: In vitro characterization of a novel TROP2-targeting antibody-drug conjugate OBI-992

Abstract BACKGROUND TROP2, a transmembrane glycoprotein widely expressed on epithelial cancers, has emerged as an attractive target for antibody-drug conjugate (ADC) development. Sacituzumab govitecan, a TROP2 ADC conjugated to topoisomerase inhibitor (TOP1) SN-38, has been approved for patients with triple-negative breast cancer. This study aims to investigate the characteristics of a novel TROP2 antibody (R4702) and its ADC OBI-992, which is derived from the conjugation of R4702 with a TOP1 inhibitor exatecan. METHODS Clinical study: Prognostic roles of TROP2 and TOP1 in patients were accessed through the “Kaplan-Meier plotter” database from more than 1055 colon cancer patients. In vitro study: An ELISA study was conducted to investigate the binding epitope of R4702. Cell binding assay and Surface Plasmon Resonance were carried out to measure non-specific binding activity and binding affinity, respectively. DNA damage activity, cytotoxicity, and immunogenic cell death (ICD) effects of three TOP1 inhibitors exatecan, deruxtecan (Dxd), and SN-38, were evaluated. Cytotoxicity of OBI-992 along with other ADC was measured in both 2D and 3D spheroids cancer cells (gastric cancer NCI-N87, pancreatic cancer Capan1, and prostate cancer DU145). TROP2 and BCRP expression as well as potential mutations in TOP1 were investigated in TROP2 ADCs-induced resistant colon cancer cells. The synergistic effects of the combination of OBI-992 with PARP inhibitors were evaluated. RESULTS Clinical study: Positive correlations between high mRNA expressions of both TROP2 (p=0.0075) and TOP1 (p=0.043) with poor overall survival for colon cancer patients were found. In vitro: The R4702 antibody displayed different binding epitopes from sacituzumab and datopotamab. In addition, R4702 showed lower non-specific binding and better binding affinity to TROP2 antigen than datopotamab. The payload exatecan demonstrated excellent ICD effects. Relatively higher cytotoxicity was observed by exatecan when compared to that of Dxd and SN-38. OBI-992 exhibited excellent activities on cell growth inhibition in 2D cell cultures and 3D cell spheroids. TROP2 down-regulation and BCRP upregulation were not found in OBI-992-induced resistant cells. A mutation R364H was identified in TOP1 in the resistance study with OBI-992, which is critical for the binding to TOP1 inhibitors camptothecin analogs. Finally, a synergistic effect of OBI-992 and PARP inhibitors (talazoparib, rucaparib, niraparib, and olaparib) on the enhancement of cancer cell killing and DNA damage was observed. CONCLUSION High expression of both TROP2 and TOP1 is associated with poor survival in patients with colon cancer. R4702 is a novel TROP2 antibody with a unique binding epitope and low non-specific binding. Exatecan and exatecan-conjugated ADC OBI-992 showed high cytotoxic activities. Combination of OBI-992 with PARP inhibitors have potential in TROP2-expressing malignancies. Citation Format: Tzer-Min Kuo, Ting-Yu Chang, Jye-Yu Huang, Wei-Chien Tang, Chun-Jung Lin, Yi-Chen Wu, Chi-Huan Lu, Hao-Cheng Weng, Yu-Jung Chen, Yu-Hsuan Tsao, Cheng-Yen Wei, Lifen Shen, Wan-Fen Li, Ming-Tain Lai. In vitro characterization of a novel TROP2-targeting antibody-drug conjugate OBI-992 [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 3130.

Abstract 2998: Regulation of epidermal growth factor receptor signaling by BRCA1-microRNA 146a network

Abstract Inherited defects in the breast cancer susceptibility gene, BRCA1 are associated with an increased risk for hereditary breast, ovarian, and other cancers. BRCA1-associated basal like breast cancers (BLBCs) are high-grade ductal carcinomas that do not express ER, PR or HER2, but frequently overexpress epidermal growth factor receptor (EGFR/ErbB1/HER1). The EGFR-driven signaling network plays a pivotal role in BLBC pathogenesis. EGFR overexpression is associated with tumor progression and metastasis, resistance to radiation and chemotherapy, and poor prognosis. Growth factor receptors are regulated by multiple miRNAs, each having many targets, coordinately controlling the complex pathways of downstream signaling. We have previously reported a post-transcriptional mechanism by which BRCA1 regulates EGFR expression through the induction of miR-146a and provided a rationale for the development of miR-146a based therapeutic strategies. In addition, we have shown that BRCA1 also exerts regulatory control over dozens of important miRNAs that appear to play a critical role in breast neoplasia. From TCGA analysis, we show that low expression of these miRNAs is associated with distinctively poor overall survival of TNBC patients. Using miR-146a loss or gain of function experiments in vitro, we show that BRCA1 and miR-146a regulate EGFR signaling, stemness, epithelial-to-mesenchymal transition (EMT), extracellular matrix (ECM) remodeling and chemoresistance. Using in vivo mouse models, we demonstrate that miR-146a overexpression delays tumor formation leading to better overall survival. BLBC unlike the other subtypes, lacks targeted therapy approaches making cytotoxic chemotherapy essentially the only option for treatment. Though EGFR inhibitors have been used to treat other cancers, clinical trials for breast cancer have so far been unsuccessful due to poor response rates. Since one miRNA can target multiple genes and regulate multiple signaling pathways, our study provides evidence to suggest that restoring miR-146a could suppress EGFR-RAS-MEK signaling and the other compensatory pathways, providing a targeted therapeutic option for BRCA1 associated BLBC. Citation Format: Easwari Kumaraswamy, Raeann M. Koren Shimak, Sumedha Gunewardena, Karen L. Wendt, Dani Alexander, Stacey L. Hembruff, Roy A. Jensen. Regulation of epidermal growth factor receptor signaling by BRCA1-microRNA 146a network [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 2998.

Abstract 7192: Teriflunomide overcomes gemcitabine resistance by inhibiting the GSK3β/mTOR pathway in pancreatic cancer

Abstract Background: Pancreatic cancer (PC) is a lethal malignancy that is partly attributable to the acquisition of chemoresistance to conventional chemotherapies. Hence, developing strategies to overcome such chemoresistance is essential. Teriflunomide, an active metabolite of leflunomide, has been widely utilized in managing autoimmune disorders, and emerging evidence suggests that it can augment the efficacy of chemotherapy in cancer. We investigated the therapeutic effect of teriflunomide in overcoming resistance to Gemcitabine-based therapy in PC. Methods: We performed docking and genomewide transcriptomic profiling analyses to identify therapeutic targets of Teriflunomide associated with Gemcitabine resistance (Gem-R) in PC. Subsequently, we analyzed the TCGA dataset to determine the prognostic significance of candidate genes in PC patients. A series of experiments were performed in PC cells, and the key findings were validated in patient-derived 3D organoids and a Gem-R Mia-PaCa2 xenograft model. Results: Docking and transcriptomic profiling studies identified GSK3β, MAPK8, and MAPK9 as potential targets of Teriflunomide, which were significantly upregulated in Gem-R cell lines (P &amp;lt; 0.05). GSK3β was independently associated with poor overall and disease-free survival in PC patients. Combined Teriflunomide and Gemcitabine treatment exhibited superior synergistic anti-tumor potential, as evidenced by reducing PC cell proliferation, clonogenicity, invasion, and migration. The combined treatment with Teriflunomide and Gemcitabine primarily inhibited GSK3β phosphorylation, resulting in the silencing of the downstream AKT/mTOR pathway. Lentiviral-based silencing of GSK3β inhibited the AKT/mTOR pathway and reduced the IC50s of Gemcitabine in PC cells. Furthermore, co-administrating both drugs to Gem-R Mia-PaCa-2 xenograft mice significantly reduced tumor growth rates and volumes. These findings were recapitulated in patient-derived 3D-organoids, where the combined treatment resulted in fewer and smaller organoids vs. each drug individually (P &amp;lt; 0.05). Conclusions: We provide novel evidence that Teriflunomide helps overcome resistance to Gemcitabine by inhibiting the GSK3β/AKT/mTOR pathway, which could improve treatment outcomes in PC. Citation Format: Caiming Xu, Yuan Li, Silei Sui, Meiling Chen, Laleh Melstorm, Haiyong Han, Steven T. Rosen, Ajay Goel. Teriflunomide overcomes gemcitabine resistance by inhibiting the GSK3β/mTOR pathway in pancreatic 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 7192.

Abstract 3345: PP1 phosphatase complex at the hub of the integrated stress response: A potential therapeutic target in multiple myeloma

Abstract Protein phosphatase-1 (PP1) is a class of eukaryotic enzyme that catalyzes more than half of the phosphoserine/threonine dephosphorylation reactions, and plays essential roles in cell division, glycogen metabolism and protein synthesis. The substrate specificity of PP1 holoenzyme complex is mediated by PP1-interacting proteins and its catalytic subunits. Of note, PPP1R15B/CReP and PPP1R15A/GADD34 are regulatory subunits of PP1 complex that regulates global protein synthesis and mRNA translation through eIF2α dephosphorylation. Notably, PPP1R15B is constitutively expressed, whereas the expression of PPP1R15A is stress-inducible. Previous studies showed that multiple myeloma (MM), a hematological malignancy arising from immunoglobulin-secreting plasma cells, is characterized by continual ER stress and high dependency on the unfolded protein response (UPR). The integrated stress response (ISR) activated by eIF2α phosphorylation is the fastest reaction pathway of the UPR; however, its functional role and therapeutic potential in MM remains largely unknown. In this study, we performed gene expression analysis and super-enhancer (SE) profiling in MM cell lines, primary patient samples, normal CD138+ plasma cells and memory B cells. we found that PPP1R15B is highly expressed in MM cells as compared to healthy controls, but did not observe significant upregulation of PPP1R15A in MM cells. In addition, higher expression of PPP1R15B predicted poor overall survival of MM patients, suggesting its clinical relevance in MM pathogenesis. Depletion of PPP1R15B significantly reduced cell viability, proliferation and induced G2/M phase cell cycle arrest. Gene Ontology analysis of downregulated genes in response to PPP1R15B knockdown indicates significant association with the UPR pathway. Immunoblot analysis showed activation of ER stress pro-apoptotic executors PUMA, NOXA, and cleavage of caspase-12 in PPP1R15B knockdown cells. Furthermore, we examined the therapeutic effects of eIF2α dephosphorylation inhibitors, Salubrinal and Raphin1, on MM cells. Raphin1 is a selective inhibitor of PPP1R15B that binds strongly to the PPP1R15B-PP1c complex, whereas Salubrinal inhibits both PPP1R15A-PP1c and PPP1R15B-PP1c complex. Our data showed that both Salubrinal and Raphin1 inhibited MM cell proliferation in a dose-dependent manner, while sparing normal plasma cells. MM cell lines with elevated PPP1R15B expression level were more sensitive to Salubrinal or Raphin1 than those with lower PPP1R15B level. Similar changes in the expression patterns of ISR-related genes were observed in response to eIF2α dephosphorylation inhibitors. Taken together, our study suggests that targeting PPP1R15B-PP1c complex or maintaining eIF2α hyperphosphorylation may serve as a new therapeutic approach in MM, which warrants further investigation. Citation Format: Sinan Xiong, Jianbiao Zhou, Tze King Tan, Sabrina Hui-Min Toh, Tae-Hoon Chung, Takaomi Sanda, Wee Joo Chng. PP1 phosphatase complex at the hub of the integrated stress response: A potential therapeutic target in multiple myeloma [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 3345.

Abstract 2690: The role of PCNA tyrosine phosphorylation in evading innate immune surveillance

Abstract Cancer cells are continually exposed to intrinsic and extrinsic proliferative stresses that can send the genome stability awry. The aberrant DNA metabolism, evolving through deregulated replicative growth in cancer cells, is increasingly recognized as a major mechanism bridging the crosstalk between the immune microenvironment and tumor tissue, thereby either promoting or suppressing tumor progression. However, the triggering and regulation of these mechanisms remain largely unknown. Proliferating cell nuclear antigen (PCNA) and its homologs are the evolutionarily conserved central components of the DNA replication machinery. In eukaryotic cells, PCNA forms homotrimeric rings encircling the DNA double helix to coordinate the complex processes of DNA replication and damage repair, directed at least in part by differential post-translational modifications of the PCNA protein. In cancer cells, growth signal-stimulated phosphorylation at tyrosine 211 of PCNA (pY211-PCNA) is known to play an important function for active proliferation. Here, we demonstrate that inhibition of pY211 disrupts the processivity of replication forks. This disruption triggers single-stranded DNA (ssDNA) production catalyzed by the MRE11 nuclease, activating the cGAS-STING axis to launch an anti-tumor immune response by natural killer (NK) cells. We further show that the pY211 regulates site-specific post-translational modifications of MRE11, and loss of pY211 promotes the endonuclease mode of MRE11. This causes ssDNA generation in the cytosol, subsequently inducing type I interferon-activated cytotoxicity by NK cells and fostering an anti-tumor immunity that abrogates distant metastasis. Mechanistically, the pY211 determines the recruitment of the writer or eraser of the modification on MRE11, thus tuning the nucleolytic modes of MRE11 and, consequently, ssDNA generation. Therapeutic measures promoting MRE11-dependent ssDNA enhance the response of triple-negative breast cancer to cytotoxic killing mediated by endogenous or allogenic NK cells in mice. In breast cancer patients, the level of cytosolic ssDNA is inversely correlated with the expression of the eraser and pY211-PCNA, which is associated with poor overall survival in cancer patients. Our studies shed new light on the shaping of the tumor immune microenvironment and demonstrate the potential to develop therapeutic approaches that proactively leverage genomic instability and immune activation to target malignant tumors. Citation Format: Chuan-Chun Lee, Wan-Rong Wu, Yi-Chun Shen, Feng-Chi Chung, Yuan-Liang Wang, You-Zhe Lin, Chih-Hao Lu, Wei-Chung Cheng, Han Chang, Liang-Chih Liu, Ji-An Liang, Chang- Fang Chiu, Mien-Chie Hung, Shao-Chun Wang. The role of PCNA tyrosine phosphorylation in evading innate immune surveillance [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 2690.

Exploring the Diagnostic and Prognostic Predictive Values of Ferroptosis- Related Markers in Lung Adenocarcinoma.

Lung Adenocarcinoma (LUAD), a common and aggressive form of lung cancer, poses significant treatment challenges due to its low survival rates. To better understand the role of ferroptosis driver genes in LUAD, this study aimed to explore their diagnostic and prognostic significance, as well as their impact on treatment approaches and tumor immune function in LUAD. To accomplish the defined goals, a comprehensive methodology incorporating both in silico and wet lab experiments was employed. A comprehensive analysis was conducted on a total of 233 ferroptosis driver genes obtained from the FerrDB database. Utilizing various TCGA databases and the RT-qPCR technique, the expression profiles of 233 genes were examined. Among them, TP53, KRAS, PTEN, and HRAS were identified as hub genes with significant differential expression. Notably, TP53, KRAS, and HRAS exhibited substantial up-regulation, while PTEN demonstrated significant down-regulation at both the mRNA and protein levels in LUAD samples. The dysregulation of hub genes was further associated with poor overall survival in LUAD patients. Additionally, targeted bisulfite-sequencing (bisulfite-seq) analysis revealed aberrant promoter methylation patterns linked to the dysregulation of hub genes. Furthermore, hub genes were found to participate in diverse oncogenic pathways, highlighting their involvement in LUAD tumorigenesis. By leveraging the diagnostic and prognostic potential of ferroptosis driver hub genes (TP53, KRAS, PTEN, and HRAS), significant advancements can be made in the understanding and management of LUAD pathogenesis. Therapeutic targeting of these genes using specific drugs holds great promise for revolutionizing drug discovery and improving the overall survival of LUAD patients.

Accurate location describe and management of lymph node recurrence after esophagectomy for thoracic esophageal squamous cell carcinoma：a retrospective cohort study.

Describe the accurate locations of lymph node recurrence LNR of Chinese patients with postoperative thoracic esophageal squamous cell carcinoma (ESCC) is essential for determining the need for further surveillance protocols and treatments. We aimed to evaluate the patterns of postoperative ESCC and its current risk stratification with LNR. This population-based cohort study included a retrospective review of the medical records and image material of patients with ESCC who underwent LNR after radical surgery between January 2013 and September 2022, with a median follow-up time of 5.71 years. Clinical features were extracted from these records, and survival analysis was performed. The primary endpoint was the accurate location and range of LNR according to the nomenclature of the Japanese Society for Esophageal Diseases. The second endpoints was to explore the related factors of recurrence range (RR) and overall survival (OS) . A total of 3268 lymph node regions were recurrence from 1129 patients, with a mean of 2.89 regions per patient. No.104, 106 and 107 was the most common recurrence of thoracic ESCC with an LNR rate higher than 15%. In upper thoracic ESCC, No.105 was a common recurrence site and abdominal lymph node recurrence was rare. In lower thoracic ESCC, retroperitoneal lymph node was a unique regions (15.4%). Anastomotic recurrence is an important recurrence pattern in patients with postoperative esophageal cancer, with an incidence of 24.5%. Rates of lymph node recurrence in range of lymph node dissection was low (13.9%). The median time of LRT was 20.0 (1.5-184.0) months. High range of recurrence was associated with significantly poorer OS in patients. Multiple linear regression analysis identified demonstrated N stage, tumor differentiation, adjuvant radiotherapy and total lymph nodes removed were association with recurrence range for patients. Supraclavicular and upper mediastinums lymph nodes were common recurrence site for ESCC patients , and careful initial staging and surveillance are needed. Thorough lymph node dissection may reduce the range of regional recurrence.

The m6A modification mediated-lncRNA POU6F2-AS1 reprograms fatty acid metabolism and facilitates the growth of colorectal cancer via upregulation of FASN.

Long noncoding RNAs (lncRNAs) have emerged as key players in tumorigenesis and tumour progression. However, the biological functions and potential mechanisms of lncRNAs in colorectal cancer (CRC) are unclear. The novel lncRNA POU6F2-AS1 was identified through bioinformatics analysis, and its expression in CRC patients was verified via qRT-PCR and FISH. In vitro and in vivo experiments, such as BODIPY staining, Oil Red O staining, triglyceride (TAG) assays, and liquid chromatography mass spectrometry (LC-MS) were subsequently performed with CRC specimens and cells to determine the clinical significance, and functional roles of POU6F2-AS1. Biotinylated RNA pull-down, RIP, Me-RIP, ChIP, and patient-derived organoid (PDO) culture assays were performed to confirm the underlying mechanism of POU6F2-AS1. The lncRNA POU6F2-AS1 is markedly upregulated in CRC and associated with adverse clinicopathological features and poor overall survival in CRC patients. Functionally, POU6F2-AS1 promotes the growth and lipogenesis of CRC cells both in vitro and in vivo. Mechanistically, METTL3-induced m6A modification is involved in the upregulation of POU6F2-AS1. Furthermore, upregulated POU6F2-AS1 could tether YBX1 to the FASN promoter to induce transcriptional activation, thus facilitating the growth and lipogenesis of CRC cells. Our data revealed that the upregulation of POU6F2-AS1 plays a critical role in CRC fatty acid metabolism and might provide a novel promising biomarker and therapeutic target for CRC.

GALNT2 targeted by miR-139-5p promotes proliferation of clear cell renal cell carcinoma via inhibition of LATS2 activation

Polypeptide N-Acetylgalactosaminyltransferase (GALNTs) are critical enzymes that initiate mucin type-O glycosylation, and are closely associated with the occurrence and development of multiple cancers. However, the significance of GALNT2 in clear cell renal cell carcinoma (ccRCC) progression remains largely undetermined. Based on public multi-omics analysis, GALNT2 was strongly elevated in ccRCC versus adjoining nontumor tissues, and it displayed a relationship with poor overall survival (OS) of ccRCC patients. In addition, GALNT2 over-expression accelerated proliferation of renal cancer cell (RCC) lines. In contrast, GALNT2 knockdown using shRNAs suppressed cell proliferation, and this was rescued by LATS2 knockdown. Similarly, GALNT2 deficiency enhanced p-LATS2/LATS2 expression. LATS2 is activated by phosphorylation (p-LATS2) and, in turn, phosphorylate the downstream substrate protein YAP. Phosphorylated YAP (p-YAP) stimulated its degradation and cytoplasmic retention, as it was unable to translocate to the nucleus. This resulted in reduced cell proliferation. Subsequently, we explored the upstream miRNAs of GALNT2. Using dual luciferase reporter assay, we revealed that miR-139-5p interacted with the 3ʹ UTR of GALNT2. Low miR-139-5p expression was associated with worse ccRCC patient outcome. Based on our experiments, miR-139-5p overexpression inhibited RCC proliferation, and this phenotype was rescued by GALNT2 overexpression. Given these evidences, the miR-139-5p-GALNT2-LATS2 axis is critical for RCC proliferation, and it is an excellent candidate for a new therapeutic target in ccRCC.