SLC6A1-miR133a-CDX2 loop regulates SK-OV-3 ovarian cancer cell proliferation, migration and invasion

Structural Studies of the Taurine Transporter: A Potential Biological Target from the GABA Transporter Subfamily in Cancer Therapy

The taurine transporter (TauT, SLC6A6) is a member of the solute carrier 6 (SLC6) family, which plays multiple physiological roles. The SLC6 family is divided into four subfamilies: GABA (γ-aminobutyric acid), monoamine, glycine and neutral amino acid transporters. Proteins from the GABA group, including the taurine transporter, are primarily considered therapeutic targets for treating central nervous system disorders. However, recent studies have suggested that inhibitors of SLC6A6 could also serve as anticancer agents. Overexpression of TauT has been associated with the progression of colon and gastric cancer. The pool of known ligands of this transporter is limited and the exact spatial structure of taurine transporter remains unsolved. Understanding its structure could aid in the development of novel inhibitors. Therefore, we utilized homology modelling techniques to create models of TauT. Docking studies and molecular dynamics simulations were conducted to describe protein-ligand interactions. We compared the obtained information for TauT with literature data on other members of the GABA transporter group. Our in silico analysis allowed us to characterize the transporter structure and point out amino acids crucial for ligand binding: Glu406, Gly62 and Tyr138. The significance of selected residues was confirmed through structural studies of mutants. These results will aid in the development of novel taurine transporter inhibitors, which can be explored as anticancer agents.

Integrated Analysis of DNA Repair Genes Identifies SLC6A1 as a New Marker for the Clinical Outcome of Patients with Colorectal Cancer

Colorectal cancer (CRC) remains an important malignancy worldwide with poor prognosis. It has been known that DNA repair genes are involved in the development and progression of various tumors. Therefore, the purpose of this study was to explore DNA repair gene-based prognostic biomarkers for CRC. In this study, the expressing pattern and prognostic values of DNA repair genes in CRC patients were analyzed using TCGA database. GO and KEGG enrichment analyses were conducted to clarify the functional roles of dysregulated genes. We observed 358 differentially expressed DNA repair genes in CRC specimens, including 84 downregulated genes and 275 upregulated genes. 36 survival-related DNA repair genes were correlated with CRC patients' five-year survival, including 6 low-risk genes and 30 high-risk genes. Among the 10 overlapping genes, we focused on SLC6A1 which was highly expressed in CRC, and multivariate analysis confirmed that SLC6A1 expression as well as age and clinical stage could be regarded as an independent predicting factor for CRC prognosis. KEGG assays revealed that SLC6A1 may influence the clinical progression via regulating TGF-beta and PI3K-Akt signaling pathways. In addition, we observed that SLC6A1 was negatively regulated by SLC6A1 methylation, leading to its low expression in CRC specimens. Overall, SLC6A1 is upexpressed in CRC and can be used as a marker of poor prognosis in CRC patients.

A miR-212-3p/SLC6A1 Regulatory Sub-Network for the Prognosis of Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) is a liver cancer with a poor prognosis. Owing to the complexity and limited pathogenic mechanism research on HCC, the molecular targeted therapy has been hindered.

Methods

In this study, we categorized transcriptome data into low-Myc and high-Myc expression groups in 365 HCC samples, screened the differentially expressed RNAs, including 441 DE-lncRNAs, 99 DE-miRNAs and 612 DE-mRNAs, constructed a lncRNA-miRNA-mRNA regulatory network, and selected a hub triple regulatory network through cytoHubba analysis. Through Gene ontology and KEGG pathway, a hub regulatory network was particularly enriched in the “Wnt signaling pathway” and “Cytochrome P450-arranged by substrate type” by Metascape. The prognostic genes in the hub regulatory network were evaluated by the RNA expression analysis, Kaplan–Meier (KM) survival analysis, and correlation analysis.

Results

The results showed that miR-212-3p/SLC6A1 axis was a potential prognostic model for HCC. Furthermore, IHC analysis showed down-regulated expression of SLC6A1 in HCC tissues and Alb-Cre;Myc mouse liver cancer tissues. The genetics and epigenetic analysis indicated that SLC6A1 expression was negatively correlated with DNA methylation. Immune infiltration analysis showed a negative relation between SLC6A1 and T cell exhaustion/monocyte in liver cancer tissues.

Conclusion

In summary, the study revealed that miR-212-3p/SLC6A1 axis could serve as a crucial therapeutic target for HCC.

SLC7A2 serves as a potential biomarker and therapeutic target for ovarian cancer

The solute carrier (SLC) family is the largest group of membrane transporters, but their functions in ovarian cancer (OV) remain unclear. We analyzed SLC family members with amino acids-transporting functions in OV. The mRNA expression levels and prognostic values of SLCs in OV were analyzed in the Gene Expression Profiling Interactive Analysis and Kaplan–Meier Plotter database. Solute carrier family 7 member 2 (SLC7A2), which showed differential expression and the most significant prognostic value, was selected for further analyses. The cBioPortal database, Gene Set Enrichment Analysis and Weighted Correlation Network Analysis were used to explore the potential functions and molecular mechanisms of SLC7A2 in OV. Validations in our own samples and in Gene Expression Omnibus datasets were conducted. Functional validation in OV cell lines was carried out. In total, 73 SLC family members were analyzed. Seven members were upregulated while 11 members were downregulated in OV and 15 members were protective factors for prognosis while 12 members were risk factors. SLC7A2 was downregulated in OV, and it was positively associated with prognosis. Knockdown of SLC7A2 promoted viability, invasion and migration of OV cells. These SLC family members and in particular SLC7A2 represented novel biomarkers for diagnosis and treatment for OV.