Cisplatin induces HepG2 cell cycle arrest through targeting specific long noncoding RNAs and the p53 signaling pathway

Abstract

Cisplatin has been used effectively in the treatment of hepatocellular carcinoma (HCC). Long noncoding RNAs (lncRNAs) were recently reported to contribute to the pathogenesis and progression of HCC. Their molecular mechanism related to cisplatin treatment remains unclear. The purpose of this study is to identify specific lncRNAs and to clarify their functions in HCC after cisplatin exposure. Reannotation and identification of differentially expressed lncRNAs were performed using the microarray data set GSE38122 in the Gene Expression Omnibus database. Four significantly differentially expressed lncRNAs (RP11-134G8.8, RP11-612B6.2, RP11-363E7.4 and RP1-193H18.2) were identified in HepG2 cells exposed to cisplatin by bioinformatics methods. The upregulated RP11-134G8.8 and RP11-363E7.4 and the downregulated RP1-193H18.2 were confirmed by reverse transcription-quantitative polymerase chain reaction. Furthermore, 57 significant co-expressing genes and their corresponding pathways were annotated and identified. The p53 signaling pathway showed the most significant difference among all pathways. Based on these results, the cell cycle and three key genes, cyclin-dependent kinase inhibitor 1A (CDKN1A, also known as p21), tumor protein p53 inducible protein 3 (TP53I3) and wild-type p53-induced phosphatase 1 (Wip1, also known as PPM1D), were examined. CDKN1A, TP53I3 and PPM1D were all downregulated by RP1-193H18.2 but upregulated by RP11-134G8.8 and RP11-363E7.4. And obvious S phase arrest was induced by cisplatin treatment for 24 h in HepG2 cells. Finally, the immunofluorescence results showed upregulation of TP53I3 and Wip1 and downregulation of p21 at the protein level. The results suggested that the lncRNAs RP11-134G8.8, RP11-363E7.4 and RP1-193H18.2, and their co-expression genes, which annotated into the p53 signaling pathway, could be potential targets for cisplatin treatment.

A Novel LncRNA-miRNA-mRNA Triple Network Identifies LncRNA RP11-363E7.4 as An Important Regulator of miRNA and Gene Expression in Gastric Cancer

“…Wang et al reported that the expression level of lncRNA RP11-363E7.4 was elevated in cisplatin-treated HepG2 cells as assessed by microarray analyses, and finally confirmed with qPCR. Further experiments showed that lncRNA RP11-363E7.4 positively regulated CDKN1A, TP53I3 and PPM1D at the gene level [52]. In our study, we confirmed with qPCR that lncRNA RP-11363E7.4 had decreased expression in five GC tissues.…”

Overexpression of long non‐coding RNA RP11‐363E7.4 inhibits proliferation and invasion in gastric cancer

“…It has been reported to be dysregulated in papillary thyroid carcinoma, in hepatocellular carcinoma after cisplatin exposure, and in patients with atrial fibrillation and myocardial infarction. [17][18][19][20] As previously reported, it was downregulated in GC tissues according to the tissue microarrays results, while high expression of lncRNA RP11-363E7. 4 was associated with better overall survival in GC patients.…”

Potential biomarkers of HCC based on gene expression and DNA methylation profiles

“…It was demonstrated that the most frequently identified mutations in HCC led to inactivation of p53. Cisplatin has been effectively used in the treatment of HCC, and p53 signaling is a potential target of cisplatin treatment (27). Paired box 5 (PAX5) has been suggested to be a functional tumor suppressor involved in HCC through direct regulation of the p53 signaling pathway, and Ras association domain family member 10 has been demonstrated to suppress human HCC growth by activating p53 signaling (28,29).…”