Project description:Reactivation of transposable elements (TEs) in somatic tissues, particularly of LINE-1, is associated with disease by causing gene mutations and DNA damage. Previous work has shown that the PIWI pathway is crucial for TE suppression in the germline. However, the status and function of this pathway is not well characterized in differentiated somatic cells and there is lack of consensus on the role of the pathway in somatic tumorigenesis. To shed light on this conundrum, we examined the PIWI pathway in colon cancer through combining bioinformatic analyses and cell-based assays. Shifted Weighted Annotation Network (SWAN) analysis revealed that the pathway experiences significant allelic losses in colon cancer and that PIWIL2, the main catalytic component of the pathway responsible for TE silencing, experiences the highest percent deletions. PIWIL2 is downregulated in colon tumors of advanced stage, nodal metastasis, and in certain subtypes, correlating with poor survival, while it is also downregulated in ulcerative colitis, an inflammatory bowel disease that predisposes to colon cancer. PIWIL2 depletion in colon epithelial Caco2 cells leads to increased anchorage-independent growth, loss of transposon-targeting - non-canonical - piRNAs, increased LINE-1 levels and activity, and in DNA damage, altogether highlighting a tumor-suppressing role of PIWIL2 in the colon.

2025-07-31 | GSE303118 | GEO

Transcription factor ZIC2 regulates tumorigenic phenotypes in epithelial ovarian cancer in a context-dependent manner

Project description:Transcription factor ZIC2 plays a pro-tumorigenic role in several human cancers. Herein, we demonstrate that elevated ZIC2 expression was associated with lower overall and post-progression survival of epithelial ovarian cancer (EOC) patients. Knockout of ZIC2 in EOC cells attenuated tumorigenic phenotypes in vitro and in vivo, indicating a pro-tumorigenic role for ZIC2 in EOC. On the other hand, however, overexpression of ZIC2 in EOC cells that do not express endogenous ZIC2 promoted cell migration and sphere formation, but inhibited cell growth and colony formation in vitro and tumor growth in vivo, indicating a context-dependent function for ZIC2 in EOC. Transcriptomic study showed that ZIC2-regulated genes were involved in multiple biological processes and signaling pathways associated with tumor progression and that ZIC2 regulated common or distinct genes in ZIC2 knockout and overexpression models, which explains the consistency and discrepancy in ZIC2 functions observed in the two models. In conclusion, our findings reveal a context-dependent role for ZIC2 in regulating tumorigenic phenotypes in EOC, providing evidence that ZIC2 can be a potential therapeutic target for EOCs that express a high level of ZIC2.

2024-05-01 | GSE227395 | GEO

Convergence of oncogenic and hormone receptor pathways promotes pro-metastatic phenotypes.

Project description:Cyclin D1b is a splice variant of the cell cycle regulator Cyclin D1 and is known to harbor divergent and highly oncogenic functions in human disease. While Cyclin D1b is induced during disease progression in many cancer types, the mechanisms underlying Cyclin D1b function remain poorly understood. Herein, models of human disease were utilized to resolve the downstream pathways requisite for the pro-tumorigenic functions of Cyclin D1b. Specifically, it was shown that Cyclin D1b modulates the expression of a large transcriptional network that cooperates with AR signaling to enhance tumor cell growth and invasive potential. Notably, Cyclin D1b promoted AR-dependent activation of genes associated with metastatic phenotypes. Further exploration determined that transcriptional induction of SNAI2 (Slug) was essential for Cyclin D1b- mediated proliferative and invasive properties, implicating Slug as a critical driver of disease progression. Importantly, Cyclin D1b expression highly correlated with that of Slug in clinical samples of advanced disease. Further, in vivo analyses provided strong evidence that Slug enhances both tumor growth and homing to distal soft tissues. Collectively, these findings reveal the underpinning mechanisms behind the pro-tumorigenic functions of Cyclin D1b, and demonstrate that the convergence of the Cyclin D1b-AR and Slug pathways results in the activation of processes critical for the promotion of lethal tumor phenotypes. Analysis of transcriptomes under the control of individual D-type cyclin isoforms in the hormone dependent prostate cancer cell line LNCaP in the presence and absence of androgen. LNCaP cells cultured in charcoal dextran treated media were transduced with virus encoding Cyclin D1a, Cyclin D1b, or control GFP for 24 hours in biological triplicate. Cells were then stimulated with either 1nM DHT or 0.01% EtOH (vehicle control) for 16 hours and harvested for RNA

2013-03-31 | E-GEOD-40794 | biostudies-arrayexpress

Mast cells act as pro-angiogenic and pro-tumorigenic players in pituitary gonadotroph tumors

Project description:Mast cells act as pro-angiogenic and pro-tumorigenic players in pituitary gonadotroph tumors

| PRJNA1000990 | ENA

Pro-tumorigenic effects of HLA-G in Renal Cell Carcinoma

Project description:Pro-tumorigenic effects of HLA-G in Renal Cell Carcinoma

| PRJEB105427 | ENA