General physiology and biophysics

Hsa_circ_0007905 as a modulator of miR-330-5p and VDAC1: Enhancing stemness and reducing apoptosis in cervical cancer stem cells

Circular RNAs (circRNAs) are covalently closed RNA structures that play a pivotal role in the initiation and progression of cervical cancer (CC). However, it is unclear how these RNAs influence cancer stem cell (CSC)-like properties in CC. Here, we performed circRNA microarray analysis and identified an intergenic circRNA, hsa_circ_0007905, that was significantly upregulated in patients with CC. Moreover, hsa_circ_0007905 was found to be highly expressed in CSC-enriched subsets of cervical cancer cell lines. Functionally, knocking down hsa_circ_0007905 suppressed proliferative, migratory invasive and self-renewal abilities, as well as stimulated apoptosis of CSCs in CC. Mechanistically, hsa_circ_0007905 functions as a "sponge" to inversely control miR-330-5p expression, which directly targets VDAC1. Overexpressing VDAC1 or inhibiting miR-330-5p blocked the roles of silencing hsa_circ_0007905 on CSCs. Thus, we revealed the mechanism by which hsa_circ_0007905 competitively adsorbs miR-330-5p to mediate VDAC1 expression to promote stemness and inhibit apoptosis of CSCs in CC, offering an therapeutic target for treating CC.

The possible regulatory effect of the PD-1/PD-L1 signaling pathway on Tregs in ovarian cancer

Aim of this study was to investigate the possible regulatory effect of the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) signaling pathway on Tregs in ovarian cancer. Immunohistochemistry was used to detect the expression of PD-L1 and PD-1 and the presence of FOXP3+ Tregs in ovarian cancer. Then, ovarian cancer HO8910 cells were subjected to transfection with PD-L1 siRNA in vitro. CCK-8, Transwell and wound healing assays were performed to detect the biological behaviors of ovarian cancer cells. Human T-cells isolated from human peripheral blood were cocultured with HO8910 cells, which were divided into the Control, TGF-β, and TGF-β+ anti-PD-L1 groups. The proportion of differentiated Tregs was detected by flow cytometry. Mouse models of ovarian cancer were established, and PD-L1 antibody therapy was administered. Tumor growth and Treg recruitment were observed. PD-L1, PD-1 and FOXP3+ Tregs were found in ovarian cancer tissue. Patients with tumors with an advanced stage and low differentiation and lymph node metastasis had significantly higher levels of PD-1, PD-L1 and FOXP3+ Tregs. After transfection with PD-L1 siRNA, HO8910 cells showed a significant reduction in PD-L1 expression, proliferation, migration and invasion. After T-cells were cocultured with ovarian cancer cells, the TGF-β+ anti-PD-L1 group showed a substantial decline in the differentiation of T-cells into Tregs compared with the TGF-β group. Moreover, mice in the anti-PD-L1 group had significantly reduced tumor growth rates, Treg proportions in the tumor microenvironment, and FOXP3 expression.

LncRNA SOX9-AS1 promotes the development of endometrial cancer by sponging miR-497-5p and upregulating E2F transcription factor 3

Endometrial cancer (EC) is one of the most prevalent gynecologic malignancies, and long non-coding RNA (lncRNA) SOX9-AS1 has been identified as being upregulated in various cancers, indicating its potential role in driving carcinogenesis. However, the involvement and mechanism of SOX9-AS1 in EC have not been thoroughly investigated. The expression of SOX9-AS1 was assessed using qRT-PCR. The impact of molecular intervention on EC cells was evaluated through cell viability, migration, and invasion assays. Survival probability was analyzed using the Kaplan-Meier method. Bioinformatics predictions, dual-luciferase reporter assays, and rescue experiments were conducted to elucidate the specific competitive endogenous RNA (ceRNA) mechanism of the SOX9-AS1/miR-497-5p/E2F3 axis. SOX9-AS1 expression was significantly upregulated in EC tissues and cells, correlating with poor prognosis in EC patients. Knockdown of SOX9-AS1 inhibited the proliferation, migration, invasion, and glycolysis of EC cells. Mechanistically, miR-497-5p suppressed the proliferation, migration, invasion, and glycolysis of EC by targeting E2F3. Molecular interaction analysis indicate that SOX9-AS1 functions as a molecular sponge for miR-497-5p, thereby increasing E2F3 expression. Our work unveiled a novel mechanism by which SOX9-AS1 promotes EC development, suggesting that targeting the SOX9-AS1/miR-497-5p/E2F3 axis may represent a potential therapeutic strategy for EC.

Tripartite motif containing 28 (TRIM28) promotes the growth and migration of endometrial carcinoma cells by regulating the  AKT/mTOR signaling pathway

Although the medical science has been developed for decades, the molecular mechanism of endometrial cancer (EC) is not yet completely clear. Previous studies have shown that the tripartite motif containing 28 (TRIM28) plays a crucial role in tumor development. However, TRIM28 is rarely studied in EC, and its role and mechanism need to be further determined. This study was aimed to delve into the related molecular mechanism underling the role of TRIM28 in EC cell growth and migration. qPCR assays and Western blot assays revealed that the expression level of TRIM28 was higher in EC tissues or cell lines (HEC1B, AN3CA, and Ishikawa) than normal tissue or human endometrial epithelial cells (hEEC), respectively. Then, CCK-8 cell viability assay and clone formation assay were performed in HEC1B and AN3CA cell lines after overexpression or knockdown of TRIM28. The results verified that suppression of TRIM28 expression inhibited the proliferation of EC cells. The wound scratch healing assay and transwell assay were performed in HEC1B and AN3CA cell lines after overexpression or knockdown of TRIM28. The results showed that suppression of TRIM28 expression inhibited the invasion and migration of EC cells. Finally, the Western blot assays hinted that overexpression or knockdown of TRIM28 in HEC1B and AN3CA cell lines would promote or inhibit the phosphorylation of AKT and mTOR protein. These findings indicated that TRIM28 promoted the growth and migration of EC cells via regulating the AKT/mTOR pathway.