Promotes Cancer Cell Proliferation Research Articles

Low expression of lysosome-related genes KCNE1, NPC2, and SFTPD promote cancer cell proliferation and tumor associated M2 macrophage polarization in lung adenocarcinoma

BackgroundRecent research has shown that lysosomes play a critical role in the onset and progression of malignancy by regulating tumor cell death through several mechanisms. Nevertheless, the involvement of lysosome-associated genes (LSAGs) in lung adenocarcinoma (LUAD) is still not well understood. MethodsLSAGs were identified in malignant lung epithelial cells, as well as biologically and functionally annotated by the comprehensive integration of single-cell and bulk RNA-sequencing data. Prognostic characterization of LSAGs was established, of which the accuracy and reliability were assessed by one-way Cox and LASSO regression. Correlations between LSAG properties and immune cell infiltration, chemotherapy, and immunotherapy were analyzed by integrated omics data. Finally, we characterized the expression of three LSAGs (KCNE1, NPC2, and SFTPD) in malignant lung epithelium and assessed their impact on tumor malignancy related phenotypes. ResultsWe identified 18 LSAGs associated with prognosis, of which 3 LSAGs were used to construct prognostic models. High-risk patients had worse survival and the model predicted it better than other clinical indicators. Based on the functional enrichment analyses, LSAGs were associated with binding and molecular activity functions, inhibition of DNA damage repair and tumor growth, IL7 signaling pathway, and glycolysis. M0 macrophages and M1 macrophages were substantially enriched in high-risk patients. Conversely, there was a considerable enrichment of resting dendritic cells and M2 macrophages in patients at low risk. We also found that risk scores predicted the outcome of immunotherapy. In vitro, we found that KCNE1, NPC2, and SFTPD were lowly expressed in malignant epithelial cells and patients with low expression of KCNE1, NPC2, and SFTPD had a higher percentage of M2 macrophage infiltration. Overexpression of KCNE1, NPC2, and SFTPD suppressed the proliferation and invasion of malignant cells, and M0 macrophages remarkably reduced M2 macrophage polarization and cellular secretion of pro-tumor cytokines. ConclusionsWe used three LASGs—KCNE1, NPC2, and SFTPD—to develop and validate a predictive signature for LUAD patients. Furthermore, we found that low expression of KCNE1, NPC2, and SFTPD promotes lung cancer cell proliferation and invasion and M2 macrophage polarization. Our study may provide fresh perspectives for customized immunotherapy.

Long non-coding RNAs in cancer: multifaceted roles and potential targets for immunotherapy.

Cancer remains a major global health concern with high mortality rates mainly due to late diagnosis and poor prognosis. Long non-coding RNAs (lncRNAs) are emerging as key regulators of gene expression in human cancer, functioning through various mechanisms including as competing endogenous RNAs (ceRNAs) and indirectly regulating miRNA expression. LncRNAs have been found to have both oncogenic and tumor-suppressive roles in cancer, with the former promoting cancer cell proliferation, migration, invasion, and poor prognosis. Recent research has shown that lncRNAs are expressed in various immune cells and are involved in cancer cell immune escape and the modulation of the tumor microenvironment, thus highlighting their potential as targets for cancer immunotherapy. Targeting lncRNAs in cancer or immune cells could enhance the anti-tumor immune response and improve cancer immunotherapy outcomes. However, further research is required to fully understand the functional roles of lncRNAs in cancer and the immune system and their potential as targets for cancer immunotherapy. This review offers a comprehensive examination of the multifaceted roles of lncRNAs in human cancers, with a focus on their potential as targets for cancer immunotherapy. By exploring the intricate mechanisms underlying lncRNA-mediated regulation of cancer cell proliferation, invasion, and immune evasion, we provide insights into the diverse therapeutic applications of these molecules.

Disruption of PABPN1 phase separation by SNRPD2 drives colorectal cancer cell proliferation and migration through promoting alternative polyadenylation of CTNNBIP1.

Generally shortened 3' UTR due to alternative polyadenylation (APA) is widely observed in cancer, but its regulation mechanisms for cancer are not well characterized. Here, with profiling of APA in colorectal cancer tissues and poly(A) signal editing, we firstly identified that the shortened 3' UTR of CTNNIBP1 in colorectal cancer promotes cell proliferation and migration. We found that liquid-liquid phase separation (LLPS) of PABPN1 is reduced albeit with higher expression in cancer, and the reduction of LLPS leads to the shortened 3' UTR of CTNNBIP1 and promotes cell proliferation and migration. Notably, the splicing factor SNRPD2 upregulated in colorectal cancer, can interact with glutamic-proline (EP) domain of PABPN1, and then disrupt LLPS of PABPN1, which attenuates the repression effect of PABPN1 on the proximal poly(A) sites. Our results firstly reveal a new regulation mechanism of APA by disruption of LLPS of PABPN1, suggesting that regulation of APA by interfering LLPS of 3' end processing factor may have the potential as a new way for the treatment of cancer.

Enhanced Expression of Glycolytic Enzymes and Succinate Dehydrogenase Complex Flavoprotein Subunit A by Mesothelin Promotes Glycolysis and Mitochondrial Respiration in Myeloblasts of Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is an aggressive malignancy characterized by rapid growth and uncontrolled proliferation of undifferentiated myeloid cells. Metabolic reprogramming is commonly observed in the bone marrow of AML patients, as leukemia cells require increased ATP supply to support disease progression. In this study, we examined the potential role of mesothelin as a metabolic modulator in myeloid cells in AML. Mesothelin is a well-known marker of solid tumors that promotes cancer cell proliferation and survival. We initially analyzed alterations in mesothelin expression in the myeloblast subpopulations, defined as SSC-Alow/CD45dim, obtained from the bone marrow of AML patients using flow cytometry. Our results showed overexpression of mesothelin in 34.8% of AML patients. Subsequently, metabolic changes in leukemia cells were evaluated by comparing the oxygen consumption rates (OCR) of bone marrow samples derived from adult AML patients. Notably, a higher OCR was observed in the mesothelin-positive compared to the mesothelin-low and non-expressing groups. Treatment with recombinant human mesothelin protein enhanced OCR and increased the mRNA expression of glycolytic enzymes and mitochondrial complex II in KG1α AML cells. Notably, siRNA targeting mesothelin in KG1α cells led to the reduction of glycolysis-related gene expression but had no effect on the mitochondrial complex gene. The collective results demonstrate that mesothelin induces metabolic changes in leukemia cells, facilitating the acquisition of a rapid supply of ATP for proliferation in AML. Therefore, the targeting of mesothelin presents a potentially promising approach to mitigating the progression of AML through the inhibition of glycolysis and mitochondrial respiration in myeloid cells.

Stomatin-like protein 2 promotes cell proliferation and survival under 5-Fluorouracil stress in hepatocellular carcinoma.

The crucial role of STOML2 in tumor progression has been documented recently in various cancers. Previous studies have shown that STOML2 promoted cancer cell proliferation, but the underlying mechanism is not fully illustrated. The expression and clinical relevance of STOML2 in pan-cancer was analyzed by TIMER2 web platform in pan-cancer. The prognostic significance of STOML2 in HCC was evaluated utilizing KM curve and a nomogram model. Signaling pathways associated with STOML2 expression were discovered by GSEA. CCK-8 assay was performed to evaluate the proliferative capacity of HCC cells after manipulating STOML2 expression. Flow cytometry was utilized to analyze cell cycle progression. Results indicated that increased STOML2 expression in HCC linked to unfavorable clinical outcomes. Cell cycle and cell division related terms were enriched under conditions of elevated STOML2 expression via GSEA analysis. A notable decrease in cell proliferation was observed in MHCC97H with STOML2 knocked-down, accompanied by G1-phase arrest, up-regulation of p21, down-regulation of CyclinD1 and its regulatory factor MYC, while STOML2 overexpression in Huh7 showed the opposite results. These results indicated that STOML2 was responsible for HCC proliferation by regulating the expression level of MYC/cyclin D1 and p21. Furthermore, an inverse correlation was found between STOML2 expression and 5-FU sensitivity. STOML2 promotes cell cycle progression in HCC which is associated with activation of MYC/CyclinD1/p21 pathway, and modulates the response of HCC to 5-FU.

PIM3 Kinase: A Promising Novel Target in Solid Cancers

PIM3 (provirus-integrating Moloney site 3) is a serine/threonine kinase and belongs to the PIM family (PIM1, PIM2, and PIM3). PIM3 is a proto-oncogene that is frequently overexpressed in cancers originating from endoderm-derived tissues, such as the liver, pancreas, colon, stomach, prostate, and breast cancer. PIM3 plays a critical role in activating multiple oncogenic signaling pathways promoting cancer cell proliferation, survival, invasion, tumor growth, metastasis, and progression, as well as chemo- and radiation therapy resistance and immunosuppressive microenvironment. Genetic inhibition of PIM3 expression suppresses in vitro cell proliferation and in vivo tumor growth and metastasis in mice with solid cancers, indicating that PIM3 is a potential therapeutic target. Although several pan-PIM inhibitors entered phase I clinical trials in hematological cancers, there are currently no FDA-approved inhibitors for the treatment of patients. This review provides an overview of recent developments and insights into the role of PIM3 in various cancers and its potential as a novel molecular target for cancer therapy. We also discuss the current status of PIM-targeted therapies in clinical trials.

NUSAP1 promotes pancreatic ductal adenocarcinoma progression by drives the epithelial-mesenchymal transition and reduces AMPK phosphorylation

BackgroundPancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, and its molecular mechanisms are unclear. Nucleolar and spindle-associated protein 1 (NUSAP1), an indispensable mitotic regulator, has been reported to be involved in the development of several types of tumors. The biological function and molecular mechanism of NUSAP1 in PDAC remain controversial. This study explored the effects and mechanism of NUSAP1 in PDAC.MethodsDifferentially expressed genes (DEGs) were screened. A protein‒protein interaction (PPI) network was constructed to identify hub genes. Experimental studies and tissue microarray (TMA) analysis were performed to investigate the effects of NUSAP1 in PDAC and explore its mechanism.ResultsNetwork analysis revealed that NUSAP1 is an essential hub gene in the PDAC transcriptome. Genome heterogeneity analysis revealed that NUSAP1 is related to tumor mutation burden (TMB), loss of heterozygosity (LOH) and homologous recombination deficiency (HRD) in PDAC. NUSAP1 is correlated with the levels of infiltrating immune cells, such as B cells and CD8 T cells. High NUSAP1 expression was found in PDAC tissues and was associated with a poor patient prognosis. NUSAP1 promoted cancer cell proliferation, migration and invasion, drives the epithelial-mesenchymal transition and reduces AMPK phosphorylation.ConclusionsNUSAP1 is an essential hub gene that promotes PDAC progression and leads to a dismal prognosis by drives the epithelial-mesenchymal transition and reduces AMPK phosphorylation.

BRCC36 Deubiquitinates HMGCR to Regulate the Interplay Between Ferroptosis and Pyroptosis.

Various forms of programmed cell death (PCD) exhibit distinct characteristics depending on their specific molecular mechanisms, and there are interactions among these different forms. Ferroptosis, which is related to autophagy and apoptosis, has an unknown potential interaction with pyroptosis. This study revealed a mutually antagonistic relationship between ferroptosis and pyroptosis, with 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) playing a key role in their interaction. It is found that HMGCR predominantly localized to mitochondria during ferroptosis but shifted to the endoplasmic reticulum following treatment with a pyroptosis inducer. Furthermore, this study demonstrated that BRCC36 (BRCA1/BRCA2-containing complex subunit 36) deubiquitinated HMGCR in a manner dependent on deubiquitinating enzyme (DUB) activity, and inhibited ferroptosis and promoted pyroptosis. Moreover, as an oncogene in hepatocellular carcinoma (HCC), BRCC36 promoted cancer cell proliferation, migration, invasion, and tumor growth. Thiolutin, an inhibitor of BRCC36, effectively suppressed the interaction between BRCC36 and HMGCR, leading to the inhibition of HCC growth. Therefore, targeting BRCC36 can offer a novel and promising therapeutic strategy for HCC treatment. In conclusion, these findings provide new theoretical evidence for further characterizing tumor heterogeneity and offer new molecular targets for the diagnosis and treatment of HCC.

Unveiling the therapeutic potential of thymol from Nigella sativa L. seed: selective anticancer action against human breast cancer cells (MCF-7) through down-regulation of Cyclin D1 and proliferative cell nuclear antigen (PCNA) expressions.

Breast adenocarcinoma cells (MCF-7) are characterized by the overexpression of apoptotic marker genes and proliferative cell nuclear antigen (PCNA), which promote cancer cell proliferation. Thymol, derived from Nigella sativa (NS), has been investigated for its potential anti-proliferative and anticancer properties, especially its ability to suppress Cyclin D1 and PCNA expression, which are crucial in the proliferation of cancer cells. The cytotoxicity of thymol on MCF-7 cells was assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release methods. Thymol was tested at increasing concentrations (0-1000 µM) to evaluate its impact on MCF-7 cell growth. Additionally, Cyclin D1 and PCNA gene expression in thymol-treated and vehicle control groups of MCF-7 were quantified using real-time Polymerase Chain Reaction (RT-qPCR). Protein-ligand interactions were also investigated using the CB-Dock2 server. Thymol significantly inhibited MCF-7 cell growth, with a 50% inhibition observed at 200 µM. The gene expression of Cyclin D1 and PCNA was down-regulated in the thymol-treated group relative to the vehicle control. The experimental results were verified through protein-ligand interaction investigations. Thymol, extracted from NS, demonstrated specific cytotoxic effects on MCF-7 cells by suppressing the expression of Cyclin D1 and PCNA, suggesting its potential as an effective drug for MCF-7. However, additional in vivo research is required to ascertain its efficacy and safety in medical applications.

KIF2C as a potential therapeutic target: insights from lung adenocarcinoma subtype classification and functional experiments.

Objective: this study evaluates the prognostic relevance of gene subtypes and the role of kinesin family member 2C (KIF2C) in lung cancer progression. Methods: high-expression genes linked to overall survival (OS) and progression-free interval (PFI) were selected from the TCGA-LUAD dataset. Consensus clustering analysis categorized lung adenocarcinoma (LUAD) patients into two subtypes, C1 and C2, which were compared using clinical, drug sensitivity, and immunotherapy analyses. A random forest algorithm pinpointed KIF2C as a prognostic hub gene, and its functional impact was assessed through various assays and in vivo experiments. Results: The study identified 163 key genes and distinguished two LUAD subtypes with differing OS, PFI, pathological stages, drug sensitivity, and immunotherapy response. KIF2C, highly expressed in the C2 subtype, was associated with poor prognosis, promoting cancer cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT), with knockdown reducing tumor growth in mice. Conclusion: The research delineates distinct LUAD subtypes with significant clinical implications and highlights KIF2C as a potential therapeutic target for personalized treatment in LUAD.

Genome-wide analysis reveals the MORC3-mediated repression of PD-L1 expression in head and neck cancer.

Programmed death-ligand 1 (PD-L1) plays essential roles in the negative regulation of anti-tumor immunity. However, the regulatory mechanisms of PD-L1 expression need further exploration. MORC family CW-type zinc finger 3 (MORC3) is a transcriptional factor that regulates innate immune responses, but the expression and roles of MORC3 in cancers remain largely unknown. The present study explored the expression of MORC3 in cancers at both transcriptional and translational levels. The target genes and pathways were analyzed using RNA interference (RNAi), RNA sequencing (RNA-seq), and quantitative real-time polymerase chain reaction (qRT-PCR) technology in head and neck cancer cells. The expression of MORC3 and its target genes were also analyzed in single cancer cells. MORC3 was significantly downregulated in multiple cancers, including head and neck cancer, and low expression of MORC3 was associated with poor overall survival. MORC3 knockdown significantly increased the expression of many immune-related genes, including interferon (IFN)-associated genes [MX dynamin like GTPase 2 (MX2), interferon induced protein with tetratricopeptide repeats 1 (IFIT1), interferon induced protein with tetratricopeptide repeats 2 (IFIT2), interferon regulatory factor 7 (IRF7), interferon regulatory factor 9 (IRF9), interferon induced protein 44 like (IFI44L), interferon induced transmembrane protein 1 (IFITM1), interferon induced transmembrane protein 3 (IFITM3), interferon induced protein 44 (IFI44), and interferon induced with helicase C domain 1 (IFIH1)]. MORC3 knockdown significantly upregulated PD-L1 and signal transducer and activator of transcription 1 (STAT1) expression. Moreover, the LINC00880 immune-related long non-coding RNA (lnc-RNA) was upregulated by MORC3 knockdown. Silencing LINC00880 attenuated PD-L1 expression. MORC3 knockdown also increased the expression of cellular proliferation-related genes and promoted cancer cell proliferation. The present study demonstrated that MORC3 regulates IFN-associated pathways and is a novel repressor of PD-L1 expression and cancer cell proliferation.

Role of YAP Signaling in Regulation of Programmed Cell Death and Drug Resistance in Cancer.

Although recent advances in cancer treatment significantly improved the prognosis of patients, drug resistance remains a major challenge. Targeting programmed cell death is a major approach of antitumor drug development. Deregulation of programmed cell death (PCD) contributes to resistance to a variety of cancer therapeutics. Yes-associated protein (YAP) and its paralog TAZ, the main downstream effectors of the Hippo pathway, are aberrantly activated in a variety of human malignancies. The Hippo-YAP pathway, which was originally identified in Drosophila, is well conserved in humans and plays a defining role in regulation of cell fate, tissue growth and regeneration. Activation of YAP signaling has emerged as a key mechanism involved in promoting cancer cell proliferation, metastasis, and drug resistance. Understanding the role of YAP/TAZ signaling network in PCD and drug resistance could facilitate the development of effective strategies for cancer therapeutics.

Comparative analysis of silver-nanoparticles and whey-encapsulated particles from olive leaf water extracts: Characteristics and biological activity.

Nanotechnology applications have been employed to improve the stability of bioactive components and drug delivery. Natural-based extracts, especially olive leaf extracts, have been associated with the green economy not only as recycled agri-waste but also in the prevention and treatment of various non-communicable diseases (NCDs). The aim of this work was to provide a comparison between the characteristics, biological activity, and gene expression of water extract of olive leaves (OLE), green synthesized OLE silver nanoparticles (OL/Ag-NPs), and OLE whey protein capsules (OL/WPNs) of the two olive varieties, Tofahy and Shemlali. The particles were characterized by dynamic light scattering, scanning electron microscope (SEM), and Fourier transform infrared. The bioactive compounds of the preparations were evaluated for their antioxidant activity and anticancer effect on HCT-116 colorectal cells as well as for their regulatory effects on cytochrome C oxidase (Cox1) and tumor necrosis factor α (TNF-α) genes. (OL/Ag-NPs) were found to be smaller than (OL/WPNs) with sizes of (37.46±1.85 and 44.86±1.62 nm) and (227.20±2.43 and 553.02±3.60 nm) for Tofahy and Shemlali, respectively. SEM showed that Shemlali (OL/Ag-NPs) had the least aggregation due to their highest Ƹ-potential (-31.76 ± 0.87 mV). The preparations were relatively nontoxic to Vero cells (IC50 = 151.94-789.25 μg/mL), while they were cytotoxic to HCT-116 colorectal cells (IC50 = 77.54-320.64 μg/mL). Shemlali and Tofahy OLE and Tofahy OL/Ag-NPs had a higher selectivity index (2.97-7.08 μg/mL) than doxorubicin (2.36 μg/mL), indicating promising anticancer activity. Moreover, Shemlali preparations regulated the expression of Cox1 (up-regulation) and TNF-α (down-regulation) on HCT-116 cells, revealing their efficiency in suppressing the expression of genes that promote cancer cell proliferation. (OL/Ag-NPs) from Tofahy and Shemlali were found to be more stable, effective, and safe than (OL/WPNs). Consequently, OL/Ag-NPs, especially Tofahy, are the best and safest nanoscale particles that can be safely used in food and pharmaceutical applications.

Development of a Genetically Engineered Mouse Model Recapitulating LKB1 and PTEN Deficiency in Gastric Cancer Pathogenesis.

The LKB1 and PTEN genes are critical in gastric cancer (G.C.) development. LKB1, a robust tumor suppressor gene, encodes a serine/threonine kinase that directly triggers the activation of AMPK-an integral cellular metabolic kinase. The role of the LKB1 pathway extends to maintaining the stability of epithelial junctions by regulating E-cadherin expression. Conversely, PTEN, a frequently mutated tumor suppressor gene in various human cancers, emerges as a pivotal negative regulator of the phosphoinositide 3-kinase (PI3K) signaling pathway. This study is set to leverage the H+/K+ ATPase Cre transgene strain to precisely target Cre recombinase expression at parietal cells within the stomach. This strategic maneuver seeks to selectively nullify the functions of both LKB1 and PTEN in a manner specific to the stomach, thereby instigating the development of G.C. in a fashion akin to human gastric adenocarcinoma. Moreover, this study endeavors to dissect the intricate ways in which these alterations contribute to the histopathologic advancement of gastric tumors, their potential for invasiveness and metastasis, their angiogenesis, and the evolving tumor stromal microenvironment. Our results show that conditional deletion of PTEN and LKB1 provides an ideal cancer microenvironment for G.C. tumorigenesis by promoting cancer cell proliferation, angiogenesis, and metastasis.

Pan-cancer analysis of the tumorigenic role of Fanconi anemia complementation group D2 (FANCD2) in human tumors

Monoubiquitination of FANCD2 is a central step in the activation of the Fanconi anemia (FA) pathway after DNA damage. Defects in the FA pathway centered around FANCD2 not only lead to genomic instability but also induce tumorigenesis. At present, few studies have investigated FANCD2 in tumors, and no pan-cancer research on FANCD2 has been conducted. We conducted a comprehensive analysis of the role of FANCD2 in cancer using public databases and other published studies. Moreover, we evaluated the role of FANCD2 in the proliferation, migration and invasion of lung adenocarcinoma cells through in vitro and in vivo experiments, and explored the role of FANCD2 in cisplatin chemoresistance. We investigated the regulatory effect of FANCD2 on the cell cycle of lung adenocarcinoma cells by flow cytometry, and verified this effect by western blotting. FANCD2 expression is elevated in most TCGA tumors and shows a strong positive correlation with poor prognosis in tumor patients. In addition, FANCD2 expression shows strong correlations with immune infiltration, immune checkpoints, the tumor mutation burden (TMB), and microsatellite instability (MSI), which are immune-related features, suggesting that it may be a potential target of tumor immunotherapy. We further found that FANCD2 significantly promotes the proliferation, invasion, and migration abilities of lung adenocarcinoma cells and that its ability to promote cancer cell proliferation may be achieved by modulating the cell cycle. The findings indicate that FANCD2 is a potential biomarker and therapeutic target in cancer treatment by analyzing the oncogenic role of FANCD2 in different tumors.

The Targeted Degradation of BRAF V600E Reveals the Mechanisms of Resistance to BRAF-Targeted Treatments in Colorectal Cancer Cells.

The BRAF V600E mutation is frequently found in cancer. It activates the MAPK pathway and promotes cancer cell proliferation, making BRAF an excellent target for anti-cancer therapy. While BRAF-targeted therapy is highly effective for melanoma, it is often ineffective against other cancers harboring the BRAF mutation. In this study, we evaluate the effectiveness of a proteolysis targeting chimera (PROTAC), SJF-0628, in directing the degradation of mutated BRAF across a diverse panel of cancer cells and determine how these cells respond to the degradation. SJF-0628 treatment results in the degradation of BRAF V600E and a decrease in Mek activation in all cell lines tested, but the effects of the treatment on cell signaling and cell proliferation are cell-line-specific. First, BRAF degradation killed DU-4475 and Colo-205 cells via apoptosis but only partially inhibited the proliferation of other cancer cell lines. Second, SJF-0628 treatment resulted in co-degradation of MEK in Colo-205 cells but did not have the same effect in other cell lines. Finally, cell lines partially inhibited by BRAF degradation also contain other oncogenic drivers, making them multi-driver cancer cells. These results demonstrate the utility of a PROTAC to direct BRAF degradation and reveal that multi-driver oncogenesis renders some colorectal cancer cells resistant to BRAF-targeted treatment.

Abstract LB_C22: Dynamic interactions of disordered N-terminal domain of p53 in cancer

Abstract TP53 is mutated in over half of all human cancers, making it the most important tumor suppressor. p53 sequence includes an N-terminal domain (NTD), a DNA binding domain (DBD), and others. NTD is intrinsically disordered and interacts with many proteins, acting as a hub for cellular signaling. Using a combination of computational and experimental approaches, we show NTD have dynamic interactions with cyclophilin D (CypD), a mitochondria proline isomerase with key roles in cellular necrosis and mitochondrial energy metabolism. We show that a subset of p53 truncation mutations can promote cancer cell proliferation and mitochondrial metabolism in a CypD-dependent manner. Although dynamic interfaces are often considered “undruggable”, we have demonstrated that EGCG, the active ingredient of green tea, can bind to NTD and disrupt NTD-CypD interaction, inhibiting the effects of p53 truncation mutants. Our studies point to a novel mechanism for p53 gain-of-function (GOF) mutations through NTD interaction with mitochondrial CypD. Our data also provide novel insights into dynamic interactions of intrinscially disordered proteins and small molecule engagement of such challenging drug targets, with important implications for cancer treatment. Citation Format: Chunyu Wang, Baines Christopher, Jianhan Chen, Stewart Loh. Dynamic interactions of disordered N-terminal domain of p53 in cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_C22.

Abstract LB_B09: Loss of folate enzyme ALDH1L1 promotes cancer cell proliferation and xenograft tumor growth

Abstract Background: ALDH1L1 (aldehyde dehydrogenase 1 family member L1, or cytosolic 10-formyltetrahydrofolate dehydrogenase), an enzyme in folate metabolism, is abundantly expressed in several tissues. This enzyme converts 10-formyltetrahydrofolate to tetrahydrofolate (THF) and CO2 while reducing NADP+ to NADPH. ALDH1L1 is ubiquitously downregulated human cancers through DNA promoter methylation, while one cancer cell line, RT4 (derived from papillary bladder cancer), maintains high expression of ALDH1L1. Aims: We tested the hypothesis that loss of ALDH1L1 expression could provide a proliferative and survival advantage for cancer cells and tumor growth. Methods: The ALDH1L1 gene in RT4 cells was knocked down using the shRNA technique. Proliferation was evaluated using MTT assays and xCELLigence real-time cellular analysis (RTCA). Cell migration was assessed by wound healing assays. NADP+/NADPH levels and reduced folate pools were measured by ELISA and the ternary complex assays, respectively. RT4 tumors were generated in nude mice from RT4 lines by subcutaneous injections into both flanks of athymic nude mice. Tumor growth was monitored every week for 12-weeks, after which the tumors were harvested. ALDH1L1 levels in tumors were measured by Western Blot assays, while tumor proliferation was assessed by the Ki-67/H&E staining of the tumor tissue sections. Results: We found that doubling time did not differ between the wild-type (RT4) and shControl (shC) cell lines. Doubling time for the sh506 and sh572 clones was shorter than the controls by 68% and 79%, respectively. Proliferation and migration were significantly increased in sh506 and sh572 cells compared to the control lines. NADP+/NADPH levels were significantly increased for only the sh572 clone. Interestingly, tumor volume and weight were increased in both sh506 and sh572 derived tumors compared to shC tumors. The sh506 and sh572 tumors also showed a slightly increased Ki-67 proliferation index. The ALDH1L1 protein expression was completely lost in sh572 tumors but only partially decreased in sh506 tumors. Conclusions: Our study indicates that RT4 clones lacking ALDH1L1 have increased cell proliferation and tumor growth compared to wild-type RT4 cells, supporting the role of ALDH1L1 as a metabolic regulator of proliferation. Citation Format: Halle M Fogle, Mikyoung You, Jaspreet Sharma, Jonathan McCormac, Natalia I Krupenko, Sergey A Krupenko. Loss of folate enzyme ALDH1L1 promotes cancer cell proliferation and xenograft tumor growth [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_B09.

Abstract C092: PRMT1 promotes pancreatic cancer development and resistance to chemotherapy

Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of cancer due to the lack of early diagnostic markers and effective therapeutic options. While epigenetic gene regulation is critically involved in the development of various types of cancer, its role in development of PDAC and the potential of therapeutically targeting epigenetic regulators remains underexplored. To identify a targetable epigenetic regulator, we utilized public datasets of pancreatic cancer and show that protein arginine methyl transferase 1 (PRMT1) is highly expressed in pancreatic cancer cells and that high expression of PRMT1 is a poor prognosis factor. Using loss of function studies in vitro and in vivo, we show that PRMT1 is essential for promoting cancer cell proliferation and tumorigenesis. We also demonstrate that the loss of PRMT1 relates to global changes in chromatin accessibility and gene expression pattern. Notably, we revealed that high PRMT1 negatively correlates with gemcitabine sensitivity and exhibit that pharmacological inhibition of PRMT1 in combination with gemcitabine had a greater anticancer effect on pancreatic cancer cells. Collectively, we suggest PRMT1 as a key factor of pancreatic cancer development and a potential candidate of chemotherapy. Citation Format: Bomin Ku, David Eisenbarth, Dae-Sik Lim. PRMT1 promotes pancreatic cancer development and resistance to chemotherapy [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C092.

Darolutamide Added to Docetaxel Augments Antitumor Effect in Models of Prostate Cancer through Cell Cycle Arrest at the G1-S Transition.

Resistance to taxane chemotherapy is frequently observed in metastatic prostate cancer. The androgen receptor (AR) is a major driver of prostate cancer and a key regulator of the G1-S cell-cycle checkpoint, promoting cancer cell proliferation by irreversible passage to the S-phase. We hypothesized that AR signaling inhibitor (ARSi) darolutamide in combination with docetaxel could augment antitumor effect by impeding the proliferation of taxane-resistant cancer cells. We monitored cell viability in organoids, tumor volume, and PSA secretion in patient-derived xenografts (PDX) and analyzed cell cycle and signaling pathway alterations. Combination treatment increased antitumor effect in androgen-sensitive, AR-positive prostate cancer organoids and PDXs. Equally beneficial effects of darolutamide added to docetaxel were observed in a castration-resistant model, progressive on docetaxel, enzalutamide, and cabazitaxel. In vitro studies showed that docetaxel treatment with simultaneous darolutamide resulted in a reduction of cells entering the S-phase in contrast to only docetaxel. Molecular analysis in the prostate cancer cell line LNCaP revealed an upregulation of cyclin-dependent kinase inhibitor p21, supporting blockade of S-phase entry and cell proliferation. Our results provide a preclinical support for combining taxanes and darolutamide as a multimodal treatment strategy in patients with metastatic prostate cancer progressive on ARSi and taxane chemotherapy.