RESUMO
Objective@#To investigate the single nucleotide polymorphisms (SNPs) of rs600231A/G and rs4102217 G/C in the promoter region of MALAT1 (metastasis associated in lung adenocarcinoma transcript 1) gene in the healthy population of Guangxi district and analyze the differences in the population among different regions. @*Methods@#The genotypes of rs600231A/G and rs4102217G/C of 207 healthy individuals in Guangxi were detected by SNPscan high-throughput technique. The genotype and allele frequency distributions were analyzed statistically with the data of HapMap-CEU (European population), HapMap-HCB (Beijing Han population), HapMap-JPT (Japanese population) and HapMap-YRI (African population) published by Human genome Haplotype Map (HapMap). @*Results@#There were three genotypes of AA (38.2%), AG (46.4%) and GG (15.4%) in rs600231A/G, and the differences were significantly different compared with the polymorphism of Japan and Africa population (HapMap-JPT and HapMap-YRI) (P＜0.05). Compared with HapMap-CEU, the genotype difference was not statistically significant (P＞0.05), but the allele distribution was statistically different (P＜0.05). The rs4102217 G/C polymorphism contained GG(75.4%), CG(23.2%) and CC(1.4%), and the polymorphisms were significantly different from those in European and Japanese populations (P＜0.05). There was no significant difference between gender in the polymorphisms of the two loci (P＞0.05). @*Conclusion@#The polymorphisms of rs600231A/G and rs4102217G/C in the MALAT1 promoter region were found in Guangxi healthy population, and the distribution of polymorphisms may be different in the population of various regions. @*@#
RESUMO
Objective@#To test the effect of metastasis associated in lung adenocarcinoma transcript 1 (MALAT1) and/or osimertinib on the proliferation and apoptosis of HCC827 cells, and explore the potential mechanism of MALAT1 induced resistance to osimertinib.@*Methods@#We transfected HCC827 cells with LV-vector or LV-over/MALAT1. Stable transfected cells (HCC827/Vector, HCC827/MALAT1) were selected by adding puromycin. HCC827/MALAT1 cells were further transfected with the shRNA-negative control (NC) or shRNA-human epidermal growth factor receptor 3 (ERBB3) plasmid. The effects of overexpression of MALAT1, knockdown of ERBB3 and/or osimertinib on the proliferation of HCC827 cells were evaluated by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay. Cell apoptosis induced by MALAT1 overexpression, knockdown of ERBB3 and/or osimertinib treatment were analyzed by flow cytometry analysis. The expressions of EGFR and ERBB3 signal pathway related proteins in HCC827 cells treated with overexpression of MALAT1, knockdown of ERBB3 and/or osimertinib treatment were detected by western blot.@*Results@#The MTT assay showed that sensitivity to osimertinib of HCC827/MALAT1 cells were significantly repressed. The 50% inhibitive concentration (IC50) of osimertinib >4 000 nmol/L in HCC827/MALAT1 cells. However, knockdown of ERBB3 facilitated the anti-proliferation effect of osimertinib, and the IC50 of osimertinib in shRNA-ERBB3 cells was (17.27±3.21) nmol/L. The results of flow cytometry analysis showed that the apoptotic rate of HCC827/MALAT1 cells induced by 10 nmol/L osimertinib was (8.38±0.92)%, significantly lower than (27.17±5.83)% of knockdown of ERBB3 (P<0.01). Western blotting showed that the expression of p-ERBB3, p-AKT and p-extracellular regulated protein kinases (ERK) in HCC827/MALAT1 cells was markedly up-regulated, while the expression of p-epithelial growth factor receptor (EGFR) was inhibited. The expressions of p-ERBB3, p-AKT and p-ERK were marginally affected by osimertinb. However, osimertinib downregulated the expressions of p-EGFR, p-ERBB3, p-AKT and p-ERK in ERBB3 deleted cells.@*Conclusions@#MALAT1 confers resistance to osimertinb in HCC827 cells by activating of the ERBB3/PI3K/AKT and ERBB3/MAPK/ERK signaling pathways.