Long non-coding RNA PCAT-1 over-expression promotes proliferation and metastasis in gastric cancer cells through regulating CDKN1A.

Prostate cancer-associated transcript1 (PCAT-1) is a novel lncRNA that involved in cell apoptosis and proliferation of prostate cancer. However, the role of PCAT-1 on gastric cancer remains unclear. In the present study, we found that PCAT-1 was increased in gastric cancer tissues and cell lines. Over-expression of PCAT-1 was correlated with poor overall survival in gastric cancer patients. PCAT-1 knockdown through shRNA in AGS and MGC-803 cells inhibited cell proliferation, migration and invasion by regulating CDKN1A. Our data suggested that PCAT-1 could play an oncogenic role in gastric cancer progression. Silencing PCAT-1 is a potential novel therapeutic approach for gastric cancer.

miR-543 is up-regulated in gefitinib-resistant non-small cell lung cancer and promotes cell proliferation and invasion via phosphatase and tensin homolog.

MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. Here, we identified that miR-543 is up-regulated in gefitinib-resistant non-small cell lung cancer (NSCLC) patients comparing gefitinib-sensitive ones. It promotes NSCLC cell proliferation by negatively regulates its target gene PTEN. In NSCLC cell lines, CCK-8 proliferation assay indicated that the cell proliferation is promoted by miR-543 mimics. Transwell assay showed that miR-543 mimics promotes the invasion and migration of NSCLC cells. Luciferase assays confirmed that miR-543 directly binds to the 3'untranslated region of PTEN, and western blotting showed that miR-543 suppresses the expression of PTEN at the protein level. This study indicates that miR-543 promotes proliferation and invasion of NSCLC cell lines by PTEN. The miR-543 may represent a potential therapeutic target for gefitinib-resistant NSCLC intervention.