ABSTRACT
@#[Abstract] Objective ： ：To investigate the long-chain noncoding RNA (Lnc RNA) PCGEM1 regulating the lung cancer (LC) cell invasion and metastasis through the TGF-β/Smad signaling pathways. Methods： ：From March 2016 to May 2018, total 62 cases of LC patients receiving surgical treatment in our hospital were collected, including cancer tissues and normal tissues more than 2 cm away from the cancer tissues. qRT-PCR was used to detect the expression of lncRNA PCGEM1 and miR-148a in LC, corresponding para-cancer tissues and different LC cell strains. LncRNA PCGEM1 silenced cell line A549-siPCGEM1 and negative control A549-NC were constructed, and A549 was used as blank control. MTT and plate cloning assay were used to detect the effect of PCGEM1 on the proliferation of A549 cells. Transwell and scratch assay were used to detect the effect of PCGEM1 on the invasion and migration of A549 cells. The bioinformatics website StarBase was used to predict the complementary binding miRNAof PCGEM1. Furthermore, according to the website Targetscan, the genes that the corresponding miRNAs could target and bind were predicted. Results： ：qRT-PCR results showed that the expression of PCGEM1 in LC tissues and lung cancer cell lines was higher than that in normal tissues, and the expression level of miR-148a was lower than that in normal tissues (all P<0.05). The expression level of PCGEM1 in A549 cells was the highest, and the difference was statistically significant compared with other cell lines (P<0.05). After successful construction of PCGEM1 silenced cells, compared with the blank control group and A549-NC group, the cell OD492nm value of A549-siPCGEM1 group was significantly decreased, the number of cell clones and the number of matrigel matrix gels was significantly reduced, the cell migration rate was significantly reduced, the differences were statistically significant (P<0.05). According to the prediction results of StarBase website, PCGEM1 could be complementary to miR-148a, and the prediction analysis on microRNA.org website shows that miR-148a had a targeted binding site with TGF-β2. qRT-PCR and Western blotting results showed that the expression of miR-148a was significantly increased in the A549-siPCGEM1 group compared with the blank control group and A549-NC group, and the expression of TGF-β2 and p-Smad 2 was significantly decreased (P<0.05), while the expression of the above indicators in the blank control group and A549-NC group was not statistically significant (P>0.05). Conclusion： ：Lnc RNA PCGEM1 is highly expressed in lung cancer. High expression of PCGEM1 may enhance the TGF-β2/Smad2 signaling pathway by downregulation of miR-148a, thus promoting the development of LC and the malignant biological behavior.