SYT7 regulates the progression of chronic lymphocytic leukemia through interacting and regulating KNTC1

SYT7 as a Potential Prognostic Marker Promotes the Metastasis of Epithelial Ovarian Cancer Cells by Activating the STAT3 Pathway

The study aimed to investigate the impact of synaptotagmin 7 (SYT7) on the metastasis of epithelial ovarian cancer (EOC) and its potential mechanisms. This was achieved through the analysis of SYT7 expression levels and clinical relevance in EOC using bioinformatics analysis from TCGA. Additionally, the study examined the influence of SYT7 on the migration and invasion of EOC cells, as well as explored its molecular mechanisms using in vitro EOC cell lines and in vivo mouse xenograft models. Our research revealed that human EOC tissues exhibit significantly elevated levels of SYT7 compared to normal ovarian tissues, and that SYT7 expression is inversely correlated with overall survival. Suppression of SYT7 effectively impeded the migratory and invasive capabilities of CAOV3 cells, whereas overexpression of SYT7 notably accelerated tumor progression in A2780 cells. Mechanistic investigations demonstrated that SYT7 upregulates p-STAT3 and MMP2 in EOC cells. Importantly, treatment with the STAT3 inhibitor niclosamide effectively counteracted the oncogenic effects of SYT7 in EOC. The inhibition of SYT7 was found to significantly reduce in vivo tumor metastasis in a nude mouse xenograft model. Our findings suggest that the upregulation of SYT7 in EOC is associated with a negative prognosis, as it enhances tumor migration and invasion by activating the STAT3 signaling pathway. Thus, SYT7 might be utilized as a EOC prognostic marker and treatment target.

G-Quadruplex-Mediated Transcriptional Regulation of SYT7: Implications for Tumor Progression and Therapeutic Strategies

Synaptotagmin 7 (SYT7), a member of the synaptotagmin family, exhibits high expression in various tumors and is closely associated with patient prognosis. The tight regulation of SYT7 expression assumes paramount significance in the progression of tumorigenesis. In this study, we detected a high GC content in the first 1000 bp of the promoter region of SYT7, suggesting a potential role of the G-quadruplex in its transcriptional regulation. Circular dichroism spectroscopy results showed that -187 to -172 bp sequence can form a typical parallel G-quadruplex structure, and site mutation revealed the critical role of the ninth guanine in its formation. Then, treatment of two ligands of G-quadruplex (TMPyP4 and Pyridostatin) reduced both the expression of SYT7 and subsequent tumor proliferation, demonstrating the potential of the G-quadruplex as a targeted therapy for tumors. By shedding light on the pivotal role of the G-quadruplex in regulating SYT7 transcription, our study not only advances our comprehension of this intricate regulatory mechanism but also emphasizes the significance of SYT7 in tumor proliferation. These findings collectively contribute to a more comprehensive understanding of the interplay between G-quadruplex regulation and SYT7 function in tumor development.

Investigation on the molecular mechanism of SPA interference with osteogenic differentiation of bone marrow mesenchymal stem cells

Binding of Staphylococcus aureus protein A (SPA) to osteoblasts induces apoptosis and inhibits bone formation. Bone marrow-derived mesenchymal stem cells (BMSCs) have the ability to differentiate into bone, fat and cartilage. Therefore, it was important to analyze the molecular mechanism of SPA on osteogenic differentiation. We introduced transcript sequence data to screen out differentially expressed genes (DEGs) related to SPA-interfered BMSC. Protein-protein interaction (PPI) network of DEGs was established to screen biomarkers associated with SPA-interfered BMSC. Receiver operating characteristic (ROC) curve was plotted to evaluate the ability of biomarkers to discriminate between two groups of samples. Finally, we performed GSEA and regulatory analysis based on biomarkers. We identified 321 DEGs. Subsequently, 6 biomarkers (Cenpf, Kntc1, Nek2, Asf1b, Troap and Kif14) were identified by hubba algorithm in PPI. ROC analysis showed that six biomarkers could clearly discriminate between normal differentiated and SPA-interfered BMSC. Moreover, we found that these biomarkers were mainly enriched in the pyrimidine metabolism pathway. We also constructed '71 circRNAs-14 miRNAs-5 mRNAs' and '10 lncRNAs-5 miRNAs-2 mRNAs' networks. Kntc1 and Asf1b genes were associated with rno-miR-3571. Nek2 and Asf1b genes were associated with rno-miR-497-5p. Finally, we found significantly lower expression of six biomarkers in the SPA-interfered group compared to the normal group by RT-qPCR. Overall, we obtained 6 biomarkers (Cenpf, Kntc1, Nek2, Asf1b, Troap, and Kif14) related to SPA-interfered BMSC, which provided a theoretical basis to explore the key factors of SPA affecting osteogenic differentiation.

SYT7 (synaptotagmin 7) promotes cervical squamous cell carcinoma

Cervical squamous cell carcinoma (CESC) ranks among the primary contributors to global cancer-associated mortality. However, the role mediated by synaptotagmin 7 (SYT7) in CESC remains unclear. Our study employed immunohistochemistry to assess the level of SYT7 expression in the tissue microarray. Furthermore, lentiviral shRNA transduction was utilized to establish SYT7 knockdown cell line models based on HeLa and SiHa cell lines. The functional impacts of silencing SYT7 expression in vitro were evaluated. A subcutaneous xenograft model was employed to examine the tumorigenic potential of cells with or without SYT7. The content of SYT7 in CESC tissues was significantly elevated compared to adjacent normal tissues. Functionally, silencing SYT7 in HeLa and SiHa cells suppressed cell proliferation, colony formation ability, and apoptosis enhancement. Additionally, cells with suppressed SYT7 also exhibited inhibited cell migration and invasion. In vivo experiments demonstrated the loss of tumorigenic ability in SYT7 knockdown cells and suppressed tumor growth. Quantitative PCR PrimeView PathArray and apoptosis antibody array analyses revealed that upon elimination of SYT7, there was a significant upregulation observed in Caspase 8, TNF-R1 (TNF receptor superfamily member 1A), and HSPA5 (heat shock protein family A [Hsp70] member 5), while TGFBI (transforming growth factor beta-induced), RPL31 (ribosomal protein L31), LUM (lumican), HSDL2 (hydroxysteroid dehydrogenase-like 2), ITGB5 (integrin subunit beta 5), and Smad2 (SMAD family member2) were downregulated. Overall, we have demonstrated the tumor-promoting functions of SYT7 in CESC.

OTUD3 suppresses the mTORC1 signaling by deubiquitinating KPTN

Background: Ubiquitination and deubiquitination modifications play pivotal roles in eukaryotic life processes, regulating protein dynamics via the ubiquitin-proteasome pathway. Dysregulation can impact disease development, including cancer and neurodegenerative disorders. Increasing evidence highlights their role in tumorigenesis, modulating key proteins. OTUD3, a deubiquitinase, stabilizes PTEN, suppressing tumor growth by inhibiting PI3K-AKT signaling. Yet, further OTUD3 substrates remain underexplored. Methods: We employed the In vivo ubiquitination assay to investigate the ubiquitination role of OTUD3 on KPTN within the cellular context. Additionally, CRISPR/Cas9 editing and Immunofluorescence were utilized to study the impact of OTUD3 on the mTOR signaling pathway in cells. Furthermore, Cell proliferation assay and NMR were employed to explore the effects of OTUD3 on cellular growth and proliferation. Results: OTUD3 serves as a deubiquitinase for KPTN. OTUD3 interacts with KPTN, facilitated by the OTU domain within OTUD3. Further investigations confirmed KPTN's ubiquitination modification, primarily at lysine residue 49. Ubiquitination experiments demonstrated OTUD3's ability to mediate KPTN's deubiquitination without affecting its protein levels. This suggests KPTN's ubiquitination is a function-regulated, non-degradable modification. Under various amino acid starvation or stimulation conditions, overexpressing OTUD3 reduces mTORC1 signaling activation, while knocking out OTUD3 further enhances it. Notably, OTUD3's regulation of mTORC1 signaling relies on its deubiquitinase activity, and this effect is observed even in PTEN KO cells, confirming its independence from PTEN, a reported substrate. OTUD3 also promotes GATOR1's lysosomal localization, a process requiring KPTN's involvement. Ultimately, OTUD3 affects cellular metabolic pool products by downregulating the mTORC1 pathway, significantly inhibiting tumor cell growth and proliferation. Discussion: Our experiments shed light on an alternative perspective regarding the intrinsic functions of OTUD3 in inhibiting tumor development. We propose a novel mechanism involving KPTN-mediated regulation of the mTORC1 signaling pathway, offering fresh insights into the occurrence and progression of tumor diseases driven by related genes. This may inspire new approaches for drug screening and cancer treatment, potentially guiding future therapies for relevant tumors.