Oncogenic Properties Research Articles

Investigating the Genetic Diversity of Hepatitis Delta Virus in Hepatocellular Carcinoma (HCC): Impact on Viral Evolution and Oncogenesis in HCC.

Hepatitis delta virus (HDV), an RNA virus with two forms of the delta antigen (HDAg), relies on hepatitis B virus (HBV) for envelope proteins essential for hepatocyte entry. Hepatocellular carcinoma (HCC) ranks third in global cancer deaths, yet HDV's involvement remains uncertain. Among 300 HBV-associated HCC serum samples from Taiwan's National Health Research Institutes, 2.7% (8/300) tested anti-HDV positive, with 62.7% (5/8) of these also HDV RNA positive. Genotyping revealed HDV-2 in one sample, HDV-4 in two, and two samples showed mixed HDV-2/HDV-4 infection with RNA recombination. A mixed-genotype infection revealed novel mutations at the polyadenylation signal, coinciding with the ochre termination codon for the L-HDAg. To delve deeper into the possible oncogenic properties of HDV-2, the predominant genotype in Taiwan, which was previously thought to be less associated with severe disease outcomes, an HDV-2 cDNA clone was isolated from HCC for study. It demonstrated a replication level reaching up to 74% of that observed for a widely used HDV-1 strain in transfected cultured cells. Surprisingly, both forms of HDV-2 HDAg promoted cell migration and invasion, affecting the rearrangement of actin cytoskeleton and the expression of epithelial-mesenchymal transition markers. In summary, this study underscores the prevalence of HDV-2, HDV-4, and their mixed infections in HCC, highlighting the genetic diversity in HCC as well as the potential role of both forms of the HDAg in HCC oncogenesis.

The Reduction of PSMB4 in T24 and J82 Bladder Cancer Cells Inhibits the Angiogenesis and Migration of Endothelial Cells.

Bladder cancer (BC) is a malignant tumor of the urinary system with high mortality and recurrence rates. Proteasome subunit type 4 (PSMB4) is highly expressed and has been identified as having oncogenic properties in a variety of cancer types. This study aimed to explore the effect of PSMB4 knockdown on the survival, migration, and angiogenesis of human bladder cancer cells with different degrees of malignancy. We analyzed the effects of PSMB4 knockdown in bladder cancer cells and endothelial cells in the tumor microenvironment. PSMB4 was highly expressed in patients with low- and high-grade urothelial carcinoma. Inhibition of PSMB4 reduced protein expression of focal adhesion kinase (FAK) and myosin light chain (MLC), leading to reduced migration. Furthermore, the suppression of PSMB4 decreased the levels of vascular endothelial factor B (VEGF-B), resulting in lower angiogenic abilities in human bladder cancer cells. PSMB4 inhibition affected the migratory ability of HUVECs and reduced VEGFR2 expression, consequently downregulating angiogenesis. In the metastatic animal model, PSMB4 knockdown reduced the relative volumes of lung tumors. Our findings suggest the role of PSMB4 as a potential target for therapeutic strategies against human bladder cancer.

NEMO/NF-κB signaling functions as a double-edged sword in PanIN formation versus progression to pancreatic cancer

BackgroundPancreatic ductal adenocarcinoma (PDAC) is marked by a dismal survival rate, lacking effective therapeutics due to its aggressive growth, late-stage diagnosis, and chemotherapy resistance. Despite debates on NF-κB targeting for PDAC treatment, no successful approach has emerged.MethodsTo elucidate the role of NF-κB, we ablated NF-κB essential modulator (NEMO), critical for conventional NF-κB signaling, in the pancreata of mice that develop precancerous lesions (KC mouse model). Secretagogue-induced pancreatitis by cerulein injections was utilized to promote inflammation and accelerate PDAC development.ResultsNEMO deletion reduced fibrosis and inflammation in young KC mice, resulting in fewer pancreatic intraepithelial neoplasias (PanINs) at later stages. Paradoxically, however, NEMO deletion accelerated the progression of these fewer PanINs to PDAC and reduced median lifespan. Further, analysis of tissue microarrays from human PDAC sections highlighted the correlation between reduced NEMO expression in neoplastic cells and poorer prognosis, supporting our observation in mice. Mechanistically, NEMO deletion impeded oncogene-induced senescence (OIS), which is normally active in low-grade PanINs. This blockage resulted in fewer senescence-associated secretory phenotype (SASP) factors, reducing inflammation. However, blocked OIS fostered replication stress and DNA damage accumulation which accelerated PanIN progression to PDAC. Finally, treatment with the DNA damage-inducing reagent etoposide resulted in elevated cell death in NEMO-ablated PDAC cells compared to their NEMO-competent counterparts, indicative of a synthetic lethality paradigm.ConclusionsNEMO exhibited both oncogenic and tumor-suppressive properties during PDAC development. Caution is suggested in therapeutic interventions targeting NF-κB, which may be detrimental during PanIN progression but beneficial post-PDAC development.Graphical

SPG21, a potential oncogene targeted by miR-128-3p, amplifies HBx-induced carcinogenesis and chemoresistance via activation of TRPM7-mediated JNK pathway in hepatocellular carcinoma.

Chronic hepatitis B virus (HBV) infection is the primary risk factor for the malignant progression of hepatocellular carcinoma (HCC). It has been reported that HBV X protein (HBx) possesses oncogenic properties, promoting hepatocarcinogenesis and chemoresistance. However, the detailed molecular mechanisms are not fully understood. Here, we aim to investigate the effects of miR-128-3p/SPG21 axis on HBx-induced hepatocarcinogenesis and chemoresistance. The expression of SPG21 in HCC was determined using bioinformatics analysis, quantitative real-time PCR (qRT-PCR), western blotting, and immunohistochemistry (IHC). The roles of SPG21 in HCC were elucidated through a series of in vitro and in vivo experiments, including real-time cellular analysis (RTCA), matrigel invasion assay, and xenograft mouse model. Pharmacologic treatment and flow cytometry were performed to demonstrate the potential mechanism of SPG21 in HCC. SPG21 expression was elevated in HCC tissues compared to adjacent non-tumor tissues (NTs). Moreover, higher SPG21 expression correlated with poor overall survival. Functional assays revealed that SPG21 fostered HCC tumorigenesis and invasion. MiR-128-3p, which targeted SPG21, was downregulated in HCC tissues. Subsequent analyses showed that HBx amplified TRPM7-mediated calcium influx via miR-128-3p/SPG21, thereby activating the c-Jun N-terminal kinase (JNK) pathway. Furthermore, HBx inhibited doxorubicin-induced apoptosis by engaging the JNK pathway through miR-128-3p/SPG21. The study suggested that SPG21, targeted by miR-128-3p, might be involved in enhancing HBx-induced carcinogenesis and doxorubicin resistance in HCC via the TRPM7/Ca2+/JNK signaling pathway. This insight suggested that SPG21 could be recognized as a potential oncogene, offering a novel perspective on its role as a prognostic factor and a therapeutic target in the context of HCC.

Human pan-cancer analysis of the predictive biomarker for the CDKN3

BackgroundCell cycle protein-dependent kinase inhibitor protein 3 (CDKN3), as a member of the protein kinase family, has been demonstrated to exhibit oncogenic properties in several tumors. However, there are no pan-carcinogenic analyses for CDKN3.MethodsUsing bioinformatics tools such as The Cancer Genome Atlas (TCGA) and the UCSC Xena database, a comprehensive pan-cancer analysis of CDKN3 was conducted. The inverstigation encompassed the examination of CDKN3 function actoss 33 different kinds of tumors, as well as the exploration of gene expressions, survival prognosis status, clinical significance, DNA methylation, immune infiltration, and associated signal pathways.ResultsCDKN3 was significantly upregulated in most of tumors and correlated with overall survival (OS) of patients. Methylation levels of CDKN3 differed significantly between tumors and normal tissues. In addition, infiltration of CD4 + T cells, cancer-associated fibroblasts, macrophages, and endothelial cells were associated with CDKN3 expression in various tumors. Mechanistically, CDKN3 was associated with P53, PI3K-AKT, cell cycle checkpoints, mitotic spindle checkpoint, and chromosome maintenance.ConclusionOur pan-cancer analysis conducted in the study provides a comprehensive understanding of the involvement of CDKN3 gene in tumorigenesis. The findings suggest that targeting CDKN3 may potentially lead to novel therapeutic strategies for the treatment of tumors.

Predictive value of FCGBP expression for treatment response and survival in rectal cancer patients undergoing chemoradiotherapy.

Despite neoadjuvant chemoradiotherapy (CRT) being the established standard for treating advanced rectal cancer, clinical outcomes remain suboptimal, necessitating the identification of predictive biomarkers for improved treatment decisions. Previous studies have hinted at the oncogenic properties of the Fc fragment of IgG binding protein (FCGBP) in various cancers; however, its clinical significance in rectal cancer remains unclear. In this study, we first conducted an analysis of a public transcriptome comprising 46 rectal cancer patients. Focusing on cell adhesion during data mining, we identified FCGBP as the most upregulated gene associated with CRT resistance. Subsequently, we assessed FCGBP immunointensity using immunohistochemical staining on 343 rectal cancer tissue blocks. Elevated FCGBP immunointensity correlated with lymph node involvement before treatment (p = 0.001), tumor invasion, and lymph node involvement after treatment (both p < 0.001), vascular invasion (p = 0.001), perineural invasion (p = 0.041), and reduced tumor regression (p < 0.001). Univariate analysis revealed a significant association between high FCGBP immunoexpression and inferior disease-specific survival, local recurrence-free survival, and metastasis-free survival (all p ≤ 0.0002). Furthermore, high FCGBP immunoexpression independently emerged as an unfavorable prognostic factor for all three survival outcomes in the multivariate analysis (all p ≤ 0.025). Enriched pathway analysis substantiated the role of FCGBP in conferring resistance to radiation. In summary, our findings suggest that elevated FCGBP immunoexpression in rectal cancer significantly correlates with a poor response to CRT and diminished patient survival. FCGBP holds promise as a valuable prognostic biomarker for rectal cancer patients undergoing CRT.

Abstract PO5-08-06: Metabolic shift to serine pathway induced by lipids confers oncogenic properties in non-transformed breast cells

Abstract Introduction. Oncogenic factors that are local/in-breast are of great interest as they may be more specifically targetable for breast cancer prevention than systemic factors. We have identified a lipid metabolism gene signature that is enriched in breast tissue at risk for estrogen negative breast cancer (ER- BC). Utilizing the medium chain fatty acid Octanoic acid (OA) to probe lipid metabolism in non-transformed breast epithelial cells, we observed increased flux through several metabolic reactions and altered histone methylation with consequent changes in gene expression (e.g. neural genes). Neuronal signaling and regulatory circuits are observed in cancer cells of multiple origins, not just ones with ontological relationships to neurons. We hypothesize that the first and rate limiting step in the de novo serine pathway, which is catalyzed by Phosphoglycerate Dehydrogenase (PHGDH) is key to these observations. In the forward direction, PHGDH participates in the serine, one-carbon, glycine (SOG) and methionine pathways that produce the methyl donor S-adenosylmethionine (SAM) and in the reverse direction produces the oncometabolite 2-Hydroxyglycerate (2-HG). Methods. Non-transformed MCF-10A cells exposed to OA were utilized for U13C-glucose tracing. SAM and 2-HG concentrations following treatment with OA ± PHGDH inhibitor were measured by liquid chromatography. CUT&amp;RUN for H3K4me3 was performed and genes affected by OA (PMID: 28263391) were compared with OA-responsive peaks. Single cell RNA-sequencing was carried out using breast microstructures derived from reduction mammoplasty tissue exposed to vehicle or OA. Microstructures were dissociated into single cells and sequenced using the 10x Genomics platform. The digital expression matrix file containing UMIs were analyzed with Seurat. Alkaline comet assay was performed to detect DNA breaks. Results. U13C-glucose tracing in presence of OA revealed that one-carbon-THF was redirected to the methionine cycle increasing flux to methylation. Concentrations of SAM and 2-HG increased after 15- and 30-min OA exposure, respectively; PHGDH inhibitor blocked these increases. H3K4me3 CUT&amp;RUN revealed 661 differential peaks (FDR &amp;lt; 0.05) comparing OA to control. 73% of H3K4me3 OA-associated peaks were in regulatory regions of OA-induced genes (FDR &amp;lt; 0.01), these genes are involved in neural pathways, EMT and ER- BC. Motif analysis revealed an overrepresentation of binding sites for transcription factors ATF3/4 (p &amp;lt; 0.05), which are regulators of the serine pathway. Single cell RNA-sequencing revealed OA not only affected the distribution of cell subpopulations but also modulated the expression of many genes within each subcluster. The percentage of luminal progenitor subcluster 3 increased upon OA from less than 1% to about 13%. Within basal subcluster 3, OA drives the expression of ATF3, along with two of the enzymes in the de novo serine pathway: PHGDH and PSAT1. Alkaline comet assay showed DNA breaks in OA- and control 2-HG- treated cells. Conclusions. Metabolism of OA in preference to glucose and glutamine results in a metabolic shift toward the serine pathway increasing the production of SAM and 2-HG, with implications for oncogenesis: 1. SAM production results in epigenetic fostered plasticity leading to reprogramming/selecting cells that express genes consistent with a neural/neural crest-like state. These co-opted neuronal regulatory mechanisms can make critical contributions to the acquired functional capabilities that drive cancer development. 2. 2-HG exposure results in appearance of DNA breaks, which are likely consequent to the inhibition of the alpha-ketoglutarate-dependent dioxygenases KDM 4A/B by 2-HG. Their catalytic activity is required for homologous recombination repair; inhibition results in metabolic “BRCAness”. Citation Format: Mariana Bustamante Eduardo, Gannon Cottone, Shiyu Liu, Maria Paula Zappia, Elizaveta V. Benevolenskaya, Abul Bashar Mir Md. Khademul Islam, Maxim V. Frolov, Seema Khan, Susan Clare. Metabolic shift to serine pathway induced by lipids confers oncogenic properties in non-transformed breast cells [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-08-06.

Decoding long non‑coding RNAs: Friends and foes in cancer development (Review).

Cancer remains a formidable adversary, challenging medical advancements with its dismal prognosis, low cure rates and high mortality rates. Within this intricate landscape, long non‑coding RNAs (lncRNAs) emerge as pivotal players, orchestrating proliferation and migration of cancer cells. Harnessing the potential of lncRNAs as therapeutic targets and prognostic markers holds immense promise. The present comprehensive review delved into the molecular mechanisms underlying the involvement of lncRNAs in the onset and progression of the top five types of cancer. By meticulously examining lncRNAs across diverse types of cancer, it also uncovered their distinctive roles, highlighting their exclusive oncogenic effects or tumor suppressor properties. Notably, certain lncRNAs demonstrate diverse functions across different cancers, confounding the conventional understanding of their roles. Furthermore, the present study identified lncRNAs exhibiting aberrant expression patterns in numerous types of cancer, presenting them as potential indicators for cancer screening and diagnosis. Conversely, a subset of lncRNAs manifests tissue‑specific expression, hinting at their specialized nature and untapped significance in diagnosing and treating specific types of cancer. The present comprehensive review not only shed light on the intricate network of lncRNAs but also paved the way for further research and clinical applications. The unraveled molecular mechanisms offer a promising avenue for targeted therapeutics and personalized medicine, combating cancer proliferation, invasion and metastasis.

Betaglycan sustains HGF/Met signaling in lung cancer and endothelial cells promoting cell migration and tumor growth

Persistent HGF/Met signaling drives tumor growth and dissemination. Proteoglycans within the tumor microenvironment might control HGF availability and signaling by affecting its accessibility to Met (HGF receptor), likely defining whether acute or sustained HGF/Met signaling cues take place. Given that betaglycan (BG, also known as type III TGFβ receptor or TGFBR3), a multi-faceted proteoglycan TGFβ co-receptor, can be found within the tumor microenvironment, we addressed its hypothetical role in oncogenic HGF signaling. We found that HGF/Met promotes lung cancer and endothelial cells migration via PI3K and mTOR. This effect was enhanced by recombinant soluble betaglycan (solBG) via a mechanism attributable to its glycosaminoglycan chains, as a mutant without them did not modulate HGF effects. Moreover, soluble betaglycan extended the effect of HGF-induced phosphorylation of Met, Akt, and Erk, and membrane recruitment of the RhoGEF P-Rex1. Data-mining analysis of lung cancer patient datasets revealed a significant correlation between high MET receptor, HGF, and PREX1 expression and reduced patient survival. Soluble betaglycan showed biochemical interaction with HGF and, together, they increased tumor growth in immunocompetent mice. In conclusion, the oncogenic properties of the HGF/Met pathway are enhanced and sustained by GAG-containing soluble betaglycan.

NUCB2 inhibition antagonizes osteosarcoma progression and promotes anti-tumor immunity through inactivating NUCKS1/CXCL8 axis

The oncogenic properties of Nucleobindin2 (NUCB2) have been observed in various cancer types. Nevertheless, the precise understanding of the biological functions and regulatory mechanisms of NUCB2 in osteosarcoma remains limited. This investigation reported that NUCB2 was significantly increased upon glucose deprivation-induced metabolic stress. Elevated NUCB2 suppressed glucose deprivation-induced cell death and reactive oxygen species (ROS) increase. Depletion of NUCB2 resulted in a reduction in osteosarcoma cell proliferation as well as metastatic potential in vitro and in vivo. Mechanically, NUCB2 ablation suppressed C-X-C Motif Chemokine Ligand 8 (CXCL8) expression which then reduced programmed cell death 1 ligand 1 (PD-L1) expression and stimulated anti-tumor immunity mediated through cytotoxic T cells. Importantly, a combination of NUCB2 depletion with anti-PD-L1 treatment improved anti-tumor T-cell immunity in vivo. Moreover, we further demonstrated that NUCB2 interacted with NUCKS1 to inhibit its degradation, which is responsible for the transcriptional regulation of CXCL8 expression. Altogether, the outcome emphasizes the function of NUCB2 in osteosarcoma and indicates that NUCB2 elevates osteosarcoma progression and immunosuppressive microenvironment through the NUCKS1/CXCL8 pathway.

The Role of Hepatitis Viruses as Drivers of Hepatocancerogenesis.

Recently, metabolic associated steatotic liver disease (MASLD) became the leading cause of chronic liver disease worldwide and one of the most frequent causes of hepatocellular carcinoma (HCC). Nonetheless, in this epidemiological trend, viral hepatitis remains the major driver in hepatic carcinogenesis. Globally, hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma, with an overall attributable risk of approximately 40%, followed by hepatitis C virus (HCV), which accounts for 28-30% of cases, with significant geographic variations between the Eastern and Western world. Considering all the etiologies, HCC risk increases proportionally with the progression of liver disease, but the risk is consistently higher in patients with viral triggers. This evidence indicates that both direct (due to the oncogenic properties of the viruses) and indirect (through the mechanisms of chronic inflammation that lead to cirrhosis) mechanisms are involved, alongside the presence of co-factors contributing to liver damage (smoking, alcohol, and metabolic factors) that synergistically enhance the oncogenic process. The aim of this review is to analyze the oncogenic role of hepatitis viruses in the liver, evaluating epidemiological changes and direct and indirect viral mechanisms that lead to liver cancer.

Pleckstrin Homology Domain Leucine-rich Repeat Protein Phosphatase Acts as a Tumor Suppressor in Oral Squamous Cell Carcinoma.

The pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) family has been found to have both tumor-suppressor and oncogenic properties across various types and locations of cancer. Given that PHLPP has not been previously studied in oral squamous cell carcinoma (SCC), we conducted an assessment of the expression of both its isoforms in oral SCC tissues and cell lines and compared these findings to their corresponding normal counterparts. In addition, we assessed the relationship between PHLPP and clinicopathological factors and patient survival. Quantitative real-time polymerase chain reaction was used to detect the mRNA levels of PHLPP1 and PHLPP2 in cancerous and normal cell lines in addition to 124 oral SCC and noncancerous adjacent epithelia (N = 62, each). Correlations between their expression rate and clinicopathological parameters were further evaluated in 57 patients. Data were statistically analyzed with t test and paired t test, analysis of variance, Mann-Whitney U , and Cox Regression tests ( P < 0.05). We found significantly lower levels of both PHLPP isoforms in oral SCC tissues compared with noncancerous epithelia ( P < 0.001, for both). However, in the cell lines, this difference was significant only for PHLPP1 ( P = 0.027). The correlation between the two isoforms was significant only in cancerous tissues ( P < 0.001). None of the clinicopathologic factors showed significant associations with either of the isoforms and there was no correlation with survival. We showed for the first time that PHLPP1 and PHLPP2 act as tumor suppressors in oral SCC at the mRNA level. The regulation of their mRNA appears to be different between normal and cancerous tissues.

Genome-wide CRISPR screens identify novel regulators of wild-type and mutant p53 stability

Tumor suppressor p53 (TP53) is frequently mutated in cancer, often resulting not only in loss of its tumor-suppressive function but also acquisition of dominant-negative and even oncogenic gain-of-function traits. While wild-type p53 levels are tightly regulated, mutants are typically stabilized in tumors, which is crucial for their oncogenic properties. Here, we systematically profiled the factors that regulate protein stability of wild-type and mutant p53 using marker-based genome-wide CRISPR screens. Most regulators of wild-type p53 also regulate p53 mutants, except for p53 R337H regulators, which are largely private to this mutant. Mechanistically, FBXO42 emerged as a positive regulator for a subset of p53 mutants, working with CCDC6 to control USP28-mediated mutant p53 stabilization. Additionally, C16orf72/HAPSTR1 negatively regulates both wild-type p53 and all tested mutants. C16orf72/HAPSTR1 is commonly amplified in breast cancer, and its overexpression reduces p53 levels in mouse mammary epithelium leading to accelerated breast cancer. This study offers a network perspective on p53 stability regulation, potentially guiding strategies to reinforce wild-type p53 or target mutant p53 in cancer.

Inactivation of kindlin-3 increases human melanoma aggressiveness through the collagen-activated tyrosine kinase receptor DDR1.

The role of the focal adhesion protein kindlin-3 as a tumor suppressor and its interaction mechanisms with extracellular matrix constitute a major field of investigation to better decipher tumor progression. Besides the well-described role of kindlin-3 in integrin activation, evidence regarding modulatory functions between melanoma cells and tumor microenvironment are lacking and data are needed to understand mechanisms driven by kindlin-3 inactivation. Here, we show that kindlin-3 inactivation through knockdown or somatic mutations increases BRAFV600mut melanoma cells oncogenic properties via collagen-related signaling by decreasing cell adhesion and enhancing proliferation and migration in vitro, and by promoting tumor growth in mice. Mechanistic analysis reveals that kindlin-3 interacts with the collagen-activated tyrosine kinase receptor DDR1 (Discoidin domain receptor 1) modulating its expression and its interaction with β1-integrin. Kindlin-3 knockdown or mutational inactivation disrupt DDR1/β1-integrin complex in vitro and in vivo and its loss improves the anti-proliferative effect of DDR1 inhibition. In agreement, kindlin-3 downregulation is associated with DDR1 over-expression in situ and linked to worse melanoma prognosis. Our study reveals a unique mechanism of action of kindlin-3 in the regulation of tumorigenesis mediated by the collagen-activated tyrosine kinase receptor DDR1 thus paving the way for innovative therapeutic targeting approaches in melanoma.

FOXP3 promote the progression of glioblastoma via inhibiting ferroptosis mediated by linc00857/miR-1290/GPX4 axis

The oncogenic properties of members belonging to the forkhead box (FOX) family have been extensively documented in different types of cancers. In this study, our objective was to investigate the impact of FOXP3 on glioblastoma multiforme (GBM) cells. By conducting a screen using a small hairpin RNA (shRNA) library, we discovered a significant association between FOXP3 and ferroptosis in GBM cells. Furthermore, we observed elevated levels of FOXP3 in both GBM tissues and cell lines, which correlated with a poorer prognosis. FOXP3 was found to promote the proliferation of GBM cells by inhibiting cell ferroptosis in vitro and in vivo. Mechanistically, FOXP3 not only directly upregulated the transcription of GPX4, but also attenuated the degradation of GPX4 mRNA through the linc00857/miR-1290 axis, thereby suppressing ferroptosis and promoting proliferation. Additionally, the FOXP3 inhibitor epirubicin exhibited the ability to impede proliferation and induce ferroptosis in GBM cells both in vitro and in vivo. In summary, our study provided evidences that FOXP3 facilitates the progression of glioblastoma by inhibiting ferroptosis via the linc00857/miR-1290/GPX4 axis, highlighting FOXP3 as a potential therapeutic target for GBM.

Abstract 2851: Characterization of neogenes in desmoplastic small round cell tumors

Abstract Desmoplastic Small Round Cell Tumor (DSRCT) is a rare, soft tissue sarcoma caused by the EWS::WT1 fusion protein (FP). The FP acts as an aberrant transcription factor with oncogenic properties. Recently, oncogenic chimeric transcription factors (OCTF), such as EWS::WT1, were discovered to induce the expression of novel transcripts in otherwise silent genomic regions. These neogenes (NGs) are highly specific to each OCTF and not detected in normal tissue. 37 NGs were found to be associated with the EWS::WT1 FP.We explored the NGs to characterize their expression and regulation in a cohort of MD Anderson Cancer Center patients. We annotated and counted the NGs from the bulk RNA-seq data of 37 specimens. After fusion detection, only 22/37 specimens harbored the EWS::WT1 FP. We found that only the same 22 specimens robustly expressed DSRCT-specific NGs. Interestingly the NGs were heterogeneously expressed, suggesting that there may be patient-specific differences. Single-nucleus RNA-sequencing (snRNA-seq) of Ewing sarcoma (ES), CIC::DUX4 sarcoma (CDS), DSRCT, and osteosarcoma revealed that only the three sarcomas driven by an OCTF robustly expressed NGs. Notably, the DSRCT-specific NGs were only expressed in DSRCT. Similarly, ES and CDS only expressed their subtype-specific NGs. Given the robust expression of the DSRCT-specific NGs in DSRCT, we asked if the EWS::WT1 FP regulated the expression of the NGs. Knockdown (KD) of the EWS::WT1 FP in four DSRCT cell lines showed a consistent reduction in DSRCT-specific NGs. While there was variability in NG expression and EWS::WT1 FP KD sensitivity, we identified seven NGs decreased by at least 75% in all four cell lines and an additional eight NGs with 75% reduction across three cell lines. BOD-DSRCT and SK-DSRCT2 had the largest number of NGs reduced after KD, with 25/37 and 20/37 NGs with 75% expression reduction, respectively. EWS::WT1 FP has two known isoforms generated by alternative splicing in the WT1 domain that includes or excludes three amino acids, lysine, threonine, and serine (KTS) between zinc fingers 3 and 4, producing E+KTS and E-KTS isoforms. By transducing one or both isoforms into the mesothelial cell line LP9, we found 3/37 NGs were induced by the E+KTS isoform and 17/37 were induced by the E-KTS isoform, suggesting that the E-KTS isoform is primarily responsible for NG expression. Current work is underway investigating the relationship between EWS::WT1 FP binding and NG expression and the potential for NG to produce novel peptides that could serve as DSRCT immunotherapy targets. Citation Format: Danh Truong, Justin Magrath, Sean Lee, Joseph Ludwig. Characterization of neogenes in desmoplastic small round cell tumors [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 2851.

Abstract 1572: POU5F1B is a human-restricted ROCK inhibitor-sensitive oncoprotein that restructures membrane nanodomains to increase cell adhesion

Abstract Evolution confers new species with distinctive biological features, which can translate in purely mechanistic speciation or in novel phenotypic traits. POU5F1B arose by retrotransposition of POU5F1 (OCT4) in the last common ancestor of modern Hominoidae. Its human product is endowed with oncogenic properties, notably promoting gastrointestinal cancer growth and metastasis. Here, we reveal that the oncogenic action of POU5F1B requires ubiquitination of lysine residues found only in the human protein. This post-translational modification is essential for POU5F1B to localize to the cytoplasm and become acylated by the DHHC17 palmitoyltransferase. This leads to POU5F1B association with detergent-resistant membrane subdomains, where it triggers the accumulation of integrins and signaling molecules, and to a stimulation of cell focal adhesion. Finally, we determined that POU5F1B stability is critically dependent on ROCK, a crucial regulator of cytoskeletal dynamics and cell motility. Citation Format: Laia Simó-Riudalbas, Sandra Offner, Laurence Abrami, Eduard M. Unterauer, Julien Duc, Evarist Planet, Ralf Jungmann, Gisou van der Goot, Didier Trono. POU5F1B is a human-restricted ROCK inhibitor-sensitive oncoprotein that restructures membrane nanodomains to increase cell adhesion [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 1572.

Abstract 4468: Elucidating the phosphoinositide-modulatory function of INPP5B in regulating cancer stemness and tumorigenesis in liver cancer

Abstract Hepatocellular carcinoma (HCC) represents a major global health challenge, characterized by its heterogeneity and aggressive nature. Solid evidence has now suggested that tumor growth is driven by subpopulations of tumor cells with less differentiated cell states, called cancer stem cells (CSCs), which govern therapeutic resistance and tumor recurrence. Therefore, characterization of CSCs and their associated oncogenic signaling pathways is crucial to the development of more specific and sensitive HCC prognostic markers and to the design of novel targeted therapies against CSCs for HCC treatment. In search of the altered genes and pathways that are tightly associated with cancer stemness trait in HCC, we exploited the stemness and oncogenic dedifferentiation signature to mine the HCC dataset of the Cancer Genome Atlas. Phosphoinositide signaling was identified to be enriched and downregulated in the transcriptomes of HCC patients with strong stemness and dedifferentiated signature. Subsequent clinical correlation analysis found inositol polyphosphate-5-phosphatase B (INPP5B) to be the top downregulated gene in phosphoinositide signaling with its expression correlated with poor survival in HCC patients. Functional studies showed that INPP5B overexpression reversed the oncogenic and stemness properties while INPP5B knockout promoted tumor growth in immunocompetent mice. Subsequent RNA sequencing and molecular assays revealed INPP5B deregulation to be associated with lipid metabolism remodeling. Collectively, our results suggest an intricate relationship between phosphoinositide signaling and lipid metabolism through the regulation of INPP5B in HCC. The findings may open new avenue for future research aimed at devising targeted therapies to interfere with liver CSCs and enhance the prognosis of HCC patients. Citation Format: Linglin Liu, Yifei Wang, Yunong Xie, Man Tong. Elucidating the phosphoinositide-modulatory function of INPP5B in regulating cancer stemness and tumorigenesis in liver 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 4468.

Abstract 2090: The GNAQ T96S mutation enhances the oncogenic properties of breast cancer

Abstract Breast cancer (BC) is the most commonly diagnosed cancer in the world, and metastatic breast cancer (mBC) remains responsible for the majority of breast cancer deaths. In this study, we collected 615 cases of Taiwanese BC patient's tumor samples and used whole exome sequencing (WES) to clarify the genetic mutation landscape of this population. We have compared with various BC genomic databases such as TCGA, COSMIC, and MSKCC to identify 29 novel variants in 18 genes that were predicted to have a pathogenic effect. In these pathogenic variants, we found that the GNAQ T96S mutation (threonine 96 to serine alteration of the Gαq protein) was presented in 116 out of 615 BC patients (18.9%). To examine the effect of the GNAQ T96S mutation on BC, we transfected the MCF-7 and MDA-MB-231 cell lines with the wild-type or the mutant GNAQ T96S expression vector. Transfection with the GNAQ T96S expression vector enhanced cell proliferation, colony formation, migration, and activation of the MAPK pathways compared to wild-type GNAQ expression MCF-7 cells. We also found that the tumorigenicity, and tumor growth were significantly increased in the GNAQ T96S expressed MCF-7 xenograft model, and exhibited higher rates of lung metastasis in GNAQ T96S expressed MDA-MB-231 cells. Our data suggest that the GNAQ T96S mutation may play an oncogenic role in BC by potentiating the GNAQ signaling pathway. In this study, we also found several compounds that can inhibit in vitro cell proliferation and in vivo tumor growth of GNAQ T96S expressed MCF-7 cells. These compounds showed the potential to treat the mBC patients who have GNAQ T96S mutation. Citation Format: Ming-Hsi Wu, Hsiang-Ching Wang, Wei-Hsin Wang, Yen-Ju Lin, Wan-Ru Chen, Shih-Ta Chen, Chih-Wei Fu, Eric Chuang. The GNAQ T96S mutation enhances the oncogenic properties of breast 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 2090.

Abstract 883: Genetic characteristics between males and females with urothelial bladder cancer

Abstract Urothelial bladder cancer (UBC) affects the epithelial cells of the urinary tract and is the most common type of bladder cancer worldwide. Statistically, males are four times more likely to develop UBC than females. It is known that decreased expression of the KDM6A gene, coded on the X chromosome, corresponds with a higher incidence of UBC. KDM6A mutations are known to be more prevalent in females with non-muscle-invasive UBC. These mutations are targetable by inhibiting EZH2, an enzyme coded by its namesake gene. On the environmental side, males are at a higher risk of developing carcinogenic complications due to smoking and environmental toxins. However, this discrepancy fails to exist when comparing males and females who smoke similar levels. Though environmental factors may play a role in influencing behavior and altering levels of risk to develop UBC, research suggests that they do not single-handedly explain sex-based disparities in UBC. In this study, we characterize the molecular mechanisms associated with altered overall survival by uncovering previously unreported data on the expression of KDM6A and FGFR3, a commonly altered oncogene, in UBC patients. Our in silico approach consisted of broad survival data analysis through cBioPortal (n=1486), sequencing-based gene expression data through ICGC Portal (n=295), and single nucleotide polymorphism identification with the PLCO Atlas (n=69,429). The 5-year overall survival (OS) curves of 13 therapeutic and/or significantly altered genes between males and females were analyzed. BRCA2 was the only gene associated with worse survival for females with alterations. Interestingly, males with alterations to the following genes had significantly better OS outcomes: ERCC2, KDM6A, BRCA2, FGFR3. However, there was no gene whose alterations were associated with significantly better OS outcomes for females. KDM6A and FGFR3, two genes whose alterations are typically associated with worse OS outcomes in males, exhibit the opposite effect. Additionally, males exhibited significantly worse OS outcomes when presenting with CDKN2A and CDKN2B alterations, while females exhibited significantly worse OS outcomes when presenting with CDKN2A and NTRK1. A majority of European males had SNPs on the following genes: CDKN2B, ERBB2, CREBBP, while a majority of European females had SNPs on BRCA2. Differential expression also revealed 714 genes that were significantly expressed in one sex when compared to the other. Therefore, we suggest that there are unique molecular differences between sex that conflict with previous analyses; further research should be conducted to explore the effect of sex via the tumor-suppressive characteristics of KDM6A as well as oncogenic properties of FGFR3. Citation Format: Rishi Nair, Roy Khalife, Anthony Magliocco. Genetic characteristics between males and females with urothelial bladder 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 883.