Silencing of LINC00467 inhibits cell proliferation in testicular germ cell tumors cells

Abstract

A significant decrease in LINC00467 expression in testicular germ cell tumors (TGCTs) was found in our previous study in comparison to adjacent tissue. Furthermore, it was found that LINC00467 expression was upregulated in TGCTs at stages II/III in contrast to the stage I of TGCT. Additionally, a negative correlation between LINC00467 expression and both the 5-year overall survival and the 5-year disease-free survival was observed. Despite these findings, the exact role of LINC00467 in the development of TGCTs requires further investigation.  LINC00467 expression was downregulated in the NCCIT and TCam-2 cell lines via small interfering RNA (siRNA) silencing. The levels of genes expression were validated using quantitative real-time polymerase chain reaction (qRT-PCR) analyses. Cell proliferation was evaluated by the MTT and Cell Counting Kit-8 (CCK8) assays, whereas flow cytometry was used to assess the effects on the cell cycle. Western blotting analysis was used to detect expression levels of protein. Additionally, RNA-sequencing and bioinformatics methods were used to investigate the mechanism of action of LINC00467 in TGCTs. The suppression of LINC00467 expression resulted in decreased cell proliferation and induced S-phase arrest. Furthermore, that suppression of LINC00467 downregulated proliferating cell nuclear antigen (PCNA), a protein related to cell cycle regulation, while it upregulated p21 expression. In other studies involving dihydrotestosterone (DHT) stimulation, it was observed that DHT could upregulate LINC00467 expression. In addition, silencing of the LINC00467 reversed the effect of testosterone on cell proliferation. The Gene Set Enrichment Analysis (GSEA) revealed that LINC00467 regulated the p53 pathway by modulating the expression of CCNG1. Our study found that LINC00467 regulates cell proliferation by inducing S-phase arrest through the cell cycle-related proteins PCNA and p21. These findings contribute to our understanding of non-coding RNAs mechanisms involved in the development of TGCTs.