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Objective:To detect the expression of MYBL2 gene in gastric adenocarcinoma tissue and its effects on cell proliferation and invasion. Methods:A total of 100 cases of gastric adenocarcinoma tissue and 100 cases of paracancerous tissue were selected from patients who received surgery in The People's Hospital of Yuhuan between January 2017 and December 2020. Gastric adenocarcinoma cell lines MGC-803 were transfected with MYBL2 siRNA and siRNA control. The cells not transfected were used as controls. MYBL2 gene expression in gastric adenocarcinoma tissue and paracancerous tissue as well as MGC-803 were determined by quantitative real time-polymerase chain reaction. MGC-803 cell proliferation was determined by MTT. The invasive ability of MGC-803 cells was determined by Transwell assay. The migration ability of MGC-803 cells was determined by Scratch testing. MYBL2 protein expression in gastric adenocarcinoma tissue and paracancerous tissue as well as MGC-803 cells was determined by western blotting. Results:The relative mRNA expression of MYBL2 in gastric adenocarcinoma tissue was significantly higher than that in paracancerous tissue [(0.65 ± 0.17) vs. (0.18 ± 0.05), t = 26.52, P < 0.05). The relative mRNA expression of MYBL2 in the MYBL2 siRNA group (0.29 ± 0.07) was significantly lower than that in the control group (0.73 ± 0.12) and siRNA group (0.71 ± 0.16, t = 5.48, 4.16, both P < 0.05). MTT assay showed that after 24 and 48 hours of culture, MGC-803 cell proliferation rate in the MYBL2 siRNA group [(40.95 ± 5.46)%, (52.12 ± 12.27)%] was significantly lower than that in the control group [(67.84 ± 6.45)%, (87.83 ± 9.96)%] and siRNA group [(66.98 ± 7.85)%, (85.98 ± 10.24)%, t = 5.51, 3.91, 4.71, 3.67, all P < 0.05]. MGC-803 cell invasion rate in the MYBL2 siRNA group [ (62.12 ± 6.43)%] was significantly lower than that in the control group [(89.74 ± 6.56)%] and siRNA group [(88.83 ± 7.85)%, t = 5.20, 4.55, both P < 0.05]. The number of MGC-803 cells migrated in the MYBL2 siRNA group [(4.32 ± 0.84) × 10 3] was significantly lower than that in the control group [(8.95 ± 1.64) × 10 3] and siRNA group [(8.83 ± 1.78) × 10 3, t = 4.35, 3.96, both P < 0.05]. The gray value of MYBL2 protein in the gastric adenocarcinoma tissue was (0.56 ± 0.15), which was significantly higher than that in the paracancerous tissue [(0.23 ± 0.07), t = 19.93, P < 0.001]. The gray value of MYBL2 protein in the MYBL2 siRNA group was (0.21 ± 0.03), which was significantly lower than that in the control group (0.67 ± 0.15) and siRNA group (0.65 ± 0.19) ( t = 5.20, 3.96, both P < 0.05). Conclusion:MYBL2 gene is highly expressed in gastric adenocarcinoma tissue. siRNA silencing MYBL2 can decrease the ability of MGC-803 cells to proliferate, invade and migrate and downregulate MYBL2 expression. This study is highly innovative and scientific.
RESUMO
Objective To investigate the frequency of micresatellite instability (MSI) and loss of heterozygosity (LOH) and select sensitive loci for studying microsatellite DNA imbalance in thymic squamous cell carcinoma. Methods 5 microsat-ellitc polymorphism markers and extrated DNA were selected from 9 specmiens of paired thymie squamous cell carcinoma/nor-real tissues. MSI and LOH in the specmiens of thymic carcinoma and relevant pericancerou tissues were detected by polymerase chain reaction (PCR) followed by 6% polyacrylamide gel electrophoresis(PAGE) with silver staining. Results MSI or LOH was detected in 9 thymic carcinoma tissues. The frequency of MSI or LOH was 66.7% (6/9) at loci of D6S1708, 33.3% (3/9) at TP53, 33.3% (3/9)at DM, 33.3% (3/9)at D11S988 and 0% (0/9)at D8S136, LOH at D6S1708 (5/6) was a common genetic alteration. DI1S988 had only LOH alteration. Conclusion D6S1708, TP53, DM, and D11S988 are sensi-tive loci for studying microsatellite DNA imbalance in thymic squamous cell carcinoma. Microsatellite DNA imbalance may play a certain role in occurrence and development of thymic squamous cell carcinoma, and the relationship between MSi or LOH.The linicopathological features of thymic squamous cell carcinoma needs further investigation.