Purpose: Ovarian cancer is one of the leading causes of cancer-related death among women. CSGALNACT2 is a vital Golgi transferase and is related to a variety of human diseases. However, its expression pattern and function in ovarian cancer remain uncertain. Methods: The Cancer Genome Atlas and GEPIA databases were used to assess the expression of CSGALNACT2 in ovarian cancer patients. RNA-seq, qRT-PCR, and IHC were used to verify the expression of CSGALNACT2 in ovarian cancer tissues. Then, in vivo and in vitro experiments were conducted to evaluate the role of CSGALNACT2 in the progression of ovarian cancer. RNA-seq and GSEA were used to reveal the potential biological function and oncogenic pathways of CSGALNACT2. Results: We demonstrated that the mRNA expression and protein level of CSGALNACT2 were significantly downregulated in ovarian cancer and ovarian cancer metastatic tissues. CSGALNACT2 can significantly inhibit the migration, invasion, and clonogenic growth of ovarian cancer in vitro and is progressively lost during ovarian cancer progression in vivo. CSGALNACT2 suppresses ovarian cancer migration and invasion via DUSP1 modulation of the MAPK/ERK pathway through RNA-seq, KEGG analysis, and Western blotting. Moreover, CSGALNACT2 expression was correlated with immune cell infiltration and had prognostic value in different immune cell-enriched or decreased ovarian cancer. In addition, patients with CSGALNACT2 downregulation are less likely to benefit from immunotherapy. Conclusion: As an ovarian cancer suppressor gene, CSGALNACT2 inhibits the development of ovarian cancer, and it might be used as a prognostic biomarker in patients with ovarian cancer.

Background: Ovarian cancer (OV) is associated with high mortality and poses challenges in diagnosis and prognosis prediction. Ubiquitin-related genes (UbRGs) are involved in the initiation and progression of cancers, but have still not been utilized for diagnosis and prognosis of OV. Methods: K48-linked ubiquitination in ovarian tissues from our OV and control cohort was assessed using immunohistochemistry. UbRGs, including ubiquitin and ubiquitin-like regulators, were screened based on the TCGA-OV and GTEx database. Univariate Cox regression analysis identified survival-associated UbRGs. A risk model was established using the LASSO regression and multivariate Cox regression analysis. The relationship between UbRGs and immune cell infiltration, tumor mutational burden, drug sensitivity, and immune checkpoint was determined using the CIBERSORT, ESTIMATE, and Maftools algorithms, based on the Genomics of Drug Sensitivity in Cancer and TCGA-OV databases. GEPIA2.0 was used to analyze the correlation between FBXO9/UBD and DNA damage repair-related genes. Finally, FBXO9 and UBD were accessed in tissues or cells using immunohistochemistry, qPCR, and Western blot. Results: We confirmed the crucial role for ubiquitination in OV as a significant decrease of K48-linked ubiquitination was observed in primary OV lesions. We identified a prognostic signature utilizing two specific UbRGs, FBXO9 and UBD. The risk score obtained from this signature accurately predicted the overall survival of TCGA-OV training dataset and GSE32062 validation dataset. Furthermore, this risk score also showed association with immunocyte infiltration and drug sensitivity, revealing potential mechanisms for ubiquitination mediated OV risk. In addition, FBXO9, but not UBD, was found to be downregulated in OV and positively correlated with DNA damage repair pathways, suggesting FBXO9 as a potential cancer suppressor, likely via facilitating DNA damage repair. Conclusions: We identified and validated a signature of UbRGs that accurately predicts the prognosis, offers valuable guidance for optimizing chemotherapy and targeted therapies, and suggests a potential role for FBXO9 in OV.

Approved KRAS inhibitors have shown limited therapeutic benefit over standard chemotherapy in PDAC and often encounter acquired resistance due to additional genetic alterations. RAS and RB1 functionally antagonize each other, which explains why RB1 is rarely mutated in KRAS-driven tumors. In PDAC cells, CDK4/6 inhibition induced cellular senescence accompanied by partial apoptosis. However, additional treatment with a senolytic agent or an ERK inhibitor promoted more efficient tumor cell elimination. While CDK4/6 inhibition downregulated KRAS activity, it concurrently upregulated EGFR signaling in a SASP and JNK-dependent manner. Deprivation of EGFR signaling after CDK4/6 inhibition triggered apoptosis in senescent cells in a manner similar to the treatment with a senolytic agent. In contrast, specific inhibition of KRAS induced modest enhancement of EGFR activity and SASP in a JNK-independent manner. Collectively, our study proposes that the CDK4/6 inhibitor may achieve greater therapeutic efficacy when combined with the EGFR inhibitor than KRAS inhibitor monotherapy.

Ovarian cancer represents the most lethal gynecologic malignancy, with tumor metastasis being the primary contributor to patient mortality. EZH2, frequently overexpressed in various cancers, has been implicated in promoting metastatic progression through metabolic dysregulation. However, the mechanistic basis by which EZH2 reprograms cholesterol metabolism to facilitate ovarian cancer metastasis remains poorly defined. In this study, we demonstrated that EZH2 is highly expressed in both primary and metastatic ovarian cancer tissues, correlating positively with poor clinical prognosis. Genetic silencing of EZH2 significantly suppressed tumor proliferation and metastatic dissemination. Mechanistically, EZH2 overexpression activated the NF-κB-Rap1A signaling axis and orchestrated cholesterol metabolic reprogramming by activating SREBP2, while repressing TMED10, to promote ovarian cancer metastasis. Furthermore, we identified Napabucasin as a potent suppressor of EZH2/Rap1A axis and cholesterol metabolism. Notably, Napabucasin effectively inhibited ovarian cancer metastasis in vivo. Collectively, our findings elucidate a previously unrecognized mechanism by which EZH2 governs metastatic progression through cholesterol metabolic rewiring and propose Napabucasin as a promising therapeutic strategy for ovarian cancer, particularly in tumors with EZH2 hyperactivation.

Background: Ovarian cancer (OC) remains the most common cause of gynecological cancer-related death, and about 70% of these deaths are from advanced high-grade serous ovarian cancer (HGSOC). Cysteine-rich secretory protein 3 (CRISP3) is related to various human diseases; however, the roles and mechanisms of CRISP3 in HGSOC remain unclear. Methods: The clinical significance of CRISP3 in patients with OC was analyzed using the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus databases. CRISP3 expression in OC tissues was validated by RNA-sequencing (RNA-seq), quantitative PCR, and immunohistochemistry. Furthermore, we explored the effect of CRISP3 expression modulation on the biological behavior of HGSOC through CCK-8, EdU, and Transwell assays in vitro, and the differences in CRISP3 during the progression of HGSOC in vivo. We utilized RNA-seq, GSEA and Western blotting to detect CRISP3’s regulatory mechanisms. Finally, we employed data from the IMvigor210 cohort and TCGA to assess the correlation of CRISP3 with clinical response to immunotherapy, and the landscape of immune cell infiltration. Results: CRISP3 expression was markedly reduced in HGSOC. In vitro studies demonstrated that CRISP3 knockdown significantly enhanced proliferation, migration, and invasion of HGSOC cells, whereas its overexpression suppressed these malignant phenotypes. Moreover, CRISP3 expression was found to be downregulated during OC progression in vivo. Mechanistically, CRISP3 acted as a tumor suppressor through the PI3K/AKT signaling pathway to inhibit the progression and metastasis of HGSOC. Additionally, we observed an association between CRISP3 expression and CD8⁺ T cell, macrophage, neutrophil and Th1 cell infiltration. Conclusions: We demonstrate that CRISP3 suppresses tumorigenesis in HGSOC by regulating the PI3K/AKT pathway, and that alterations in its expression correlate with disease progression, supporting its utility as a biomarker.