Long non-coding RNA ZNF674-AS1 antagonizes oxaliplatin resistance of gastric cancer via regulating EZH2-mediated methylation of CHST7

Chemoresistance leads the cause of poor outcome of patients with gastric cancer (GC). Long non-coding RNAs (LncRNAs) is intimately involved in the regulation of tumorigenesis and progression. Here, we demonstrated ZNF674-AS1 was down-regulated in oxaliplatin (OXA)-resistant tissues and cell lines, lower level of ZNF674-AS1 predicted poor prognosis of GC patients. Besides, forced expression of ZNF674-AS1 not only reduced cell viability, colony formation, expression of drug-resistant markers but also promoted cell apoptosis of OXA-resistant GC cells, exposed to oxaliplatin. Silence of ZNF674-AS1 exhibited an opposite effects on OXA resistance of GC cells. Further mechanistic research showed that ZNF674-AS1 interacted with EZH2, led to higher methylation level of target gene CHST7. In addition, functional experiments verified that depletion of CHST7 re-sensitized OXA-resistant GC cells to OXA. Thus, our results indicated that ZNF674-AS1 suppressed OXA resistance of GC through EZH2-mediated inhibition of CHST7, providing potential theoretic basis and therapeutic strategy for chemoresistant GC.

Long non-coding RNA ZNF674-AS1 regulates miR-23a/E-cadherin axis to suppress the migration and invasion of non-small cell lung cancer cells

BACKGROUND

Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors. The prognosis of patients with advanced NSCLC is poor due to metastasis. In recent years, the role of long non-coding RNAs (lncRNAs), a class of non-coding RNA molecules, in NSCLC has become an increasingly popular focus of studies. This study aimed to investigate the effects of ZNF674-AS1 and microRNA (miR)-23a on the migration and invasion abilities of NSCLC cells in vitro and explore the underpinning molecular mechanisms.

METHODS

The expression levels of ZNF674-AS1 and miR-23a in NSCLC tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Scratch test and transwell test were used to detect the effects of ZNF674-AS1 and miR-23a on the migration and invasion of NSCLC cells. The luciferase reporter gene experiment was used to verify miRNA targets. Western blot experiments were used to analyze protein expression.

RESULTS

ZNF674-AS1 was downregulated in NSCLC tissues and cells, and inhibited the migration and invasion of NSCLC cells in vitro. In contrast, the expression of miR-23a, a downstream target of ZNF674-AS1, was increased in NSCLC tissues and cells. We found that miR-23a could antagonize the role of ZNF674-AS1 in NSCLC. E-cadherin was identified as a downstream target gene of miR-23a, and miR-23a could directly inhibit its expression.

CONCLUSIONS

ZNF674-AS1 inhibits the migration and invasion of NSCLC cells by regulating a miR-23a/E-cadherin axis. ZNF674-AS1 and miR-23a could become potential therapeutic targets for NSCLC.

ZNF674-AS1 antagonizes miR-423-3p to induce G0/G1 cell cycle arrest in non-small cell lung cancer cells

BACKGROUND

ZNF674-AS1, a recently characterized long noncoding RNA, shows prognostic significance in hepatocellular carcinoma and glioma. However, the expression and function of ZNF674-AS1 in non-small cell lung cancer (NSCLC) are unclear.

METHODS

In this work, we investigated the expression of ZNF674-AS1 in 83 pairs of NSCLC specimens and adjacent noncancerous lung tissues. The clinical significance of ZNF674-AS1 in NSCLC was analyzed. The role of ZNF674-AS1 in NSCLC growth and cell cycle progression was explored.

RESULTS

Our data show that ZNF674-AS1 expression is decreased in NSCLC compared to normal tissues. ZNF674-AS1 downregulation is significantly correlated with advanced TNM stage and decreased overall survival of NSCLC patients. Overexpression of ZNF674-AS1 inhibits NSCLC cell proliferation, colony formation, and tumorigenesis, which is accompanied by a G0/G1 cell cycle arrest. Conversely, knockdown of ZNF674-AS1 enhances the proliferation and colony formation of NSCLC cells. Biochemically, ZNF674-AS1 overexpression increases the expression of p21 through downregulation of miR-423-3p. Knockdown of p21 or overexpression of miR-423-3p blocks ZNF674-AS1-mediated growth suppression and G0/G1 cell cycle arrest. In addition, ZNF674-AS1 expression is negatively correlated with miR-423-3p in NSCLC specimens.

CONCLUSIONS

ZNF674-AS1 suppresses NSCLC growth by downregulating miR-423-3p and inducing p21. This work suggests the therapeutic potential of ZNF674-AS1 in the treatment of NSCLC.