Expression of MAD2L1 in Lung Adenocarcinoma and Its Effect on Immune Microenvironment / 肿瘤防治研究

Objective To investigate the expression of MAD2L1 in lung adenocarcinoma and its effect on the prognosis and immune microenvironment of patients. Methods The difference of MAD2L1 expression in lung adenocarcinoma tissue and normal lung tissue was analyzed by TCGA and GEO database. Survival analysis was carried out to evaluate the prognostic significance of MAD2L1 gene expression in lung adenocarcinoma patients. StarBase database was used to construct miRNA-MAD2L1 regulatory network of lung adenocarcinoma. The relation between the expression of MAD2L1 and immune cell infiltration in lung adenocarcinoma was analyzed by TIMER database. Results The expression of MAD2L1 was up-regulated in lung adenocarcinoma, and the high expression of MAD2L1 was significantly correlated with pathological stage and lymph node metastasis of lung adenocarcinoma. The patients with high expression of MAD2L1 had a poor prognosis. miR-101-3p/MAD2L1 axis was identified as the most potential upstream regulation pathway of MAD2L1 in lung adenocarcinoma. The expression level of MAD2L1 was significantly correlated with tumor immune cell infiltration and immune checkpoint expression. Conclusions MAD2L1 is highly expressed in lung adenocarcinoma, which is related to poor prognosis and tumor immune infiltration. MAD2L1 can be used as a potential target for the treatment of lung adenocarcinoma.

Effects of SP600125 on Proliferation and Invasion of Human Cervical Cancer HeLa Cells / 肿瘤防治研究

Objective To investigate the effect of SP600125 on the proliferation, cell cycle, apoptosis and invasion of human cervical cancer HeLa cells. Methods CCK-8 method was used to detect the proliferation of HeLa cells treated with different concentrations of SP600125 at different time points. The 20 μmol/L of SP600125 was determined for subsequent experiments. Cell proliferation ability was detected using plate clone formation assay; nuclear morphology was observed by DAPI staining; cell cycle and apoptosis were measured by flow cytometry; cell migration and invasion were detected by cell scratch and Transwell methods; the mRNA and protein levels of p53, Mad2L1 and CDC20 were measured by qRT-PCR and Western blot after SP600125 treatment at different time points. Results Compared with control group (0.1%DMSO), cells proliferative activity were reduced by 10, 20, 30, 40 and 50 μmol/L SP600125 treatment for 24h. Compared with control group, the rate of apoptosis was significantly increased in SP600125 treatment groups, and the cell proportion in G2/M phase increased (P < 0.001), while the cell proportion in G0/G1 phases cells was reduced after SP600125 treatment for 24h and 48h (P < 0.001), and the clonal number, migration and invasion ability of HeLa cells also decreased significantly (P < 0.001). qRT-PCR and Western blot results showed a significant decrease in Mad2L1 mRNA and protein expression (P < 0.05) and a significant increase in p53 and CDC20 mRNA and protein expression (P < 0.01). Conclusion SP600125 can induce cell cycle arrest of cervical cancer HeLa cells in G2/M phase by upregulating p53 and CDC20 and downregulating Mad2L1 expression, and promote cell apoptosis to inhibit cell proliferation, migration and invasion.

Mouse MAD2L1 gene editing by CRISPR/Cas9 and analysis of its off-target effect / 中国实验动物学报

Objective To establish a method for specific gene editing of the second exon of mouse MAD2L1 gene by CRISPR/Cas9, and analyze its off-target effect. Methods The gene editing site for MAD2L1 gene was designed by CHOP?CHOP, and the Cas9?MAD2L1 vector was constructed based on the designed editing site. Cas9?MAD2L1 was then transfected into NIH/3T3 cells and screened with puromycin, followed by observing GFP expression using fluorescence microscopy. The genomic DNA from transfected cells was extracted and a partial fragment of MAD2L1 gene was amplified by PCR. T7E1 analy?sis and Sangger sequencing were used for gene editing and off?target analysis. Results After Cas9?MAD2L1 transfection and puromycin screening, a large number of GFP?expressing cells were observed under the fluorescence microscope. Combined the PCR result with TE71 analysis, the amplified 228 bp PCR products can be digested into 166 bp and 62 bp fragments. The se?quencing result showed that the second exon of MAD2L1 gene was successfully edited, and the off?target effect was undetected in our system. Conclusions The method for specific gene editing of the second exon of mouse MAD2L1 gene by CRISPR/Cas9 is successfully established, and off?target effect of MAD2L1 gene is not detected.

MAD2 Expression in Ovarian Carcinoma: Different Expression Patterns and Levels among Various Types of Ovarian Carcinoma and Its Prognostic Significance in High-Grade Serous Carcinoma

BACKGROUND: Mitotic arrest deficiency protein 2 (MAD2) is a key component of spindle assembly checkpoint function, which mediates cell apoptosis through microtubule kinetics. Aberrant expression of MAD2 is believed to be associated with the development of chromosome instability. MAD2 also has a signihicant role in cellular drug resistance to taxane chemotherapeutic agents. METHODS: Expression of MAD2 and p53 was investigated using immunohistochemistry in 85 cases of ovarian carcinomas. Clinicopathological data including progression-free survival were analyzed. RESULTS: A significant (p=.035) association was observed between the grade of serous carcinoma and the expression level of MAD2. While low-grade serous carcinoma showed a low-level expression of MAD2, high-grade serous carcinoma showed a high-level expression of MAD2. We also determined that low-level expression of MAD2 was associated with reduced progression-free survival (PFS) (p=.016) in high-grade serous carcinoma. CONCLUSIONS: MAD2 expression in ovarian carcinoma is related to the grade of serous carcinoma and PFS of high-grade serous carcinoma. Expression level of MAD2 detected by immunohistochemistry may serve as an indicator in predicting the response of microtubule-interfering chemotherapeutic agents.

Mutation analysis of p31(comet) gene, a negative regulator of Mad2, in human hepatocellular carcinoma

Failure of mitotic checkpoint machinery leads to the chromosomal missegregation and nuclear endoreduplication, thereby driving the emergence of aneuploidy and tetraploidy population. Although abnormal nuclear ploidy and the resulting impairment of mitotic checkpoint function are typical physiological event leading to human hepatocellular carcinoma, any mutational change of mitotic checkpoint regulators has not yet been discovered. Therefore, we investigated the mutation of p31(comet), a recently identified mitotic checkpoint regulator, in human hepatocellular carcinoma. Of 51 human hepatocellular carcinoma tissue and 6 cell lines tested, five samples exhibited nucleotide sequence variations dispersed on four sites within the entire coding sequence. Among these sites with sequence substitutions, three were found to be missense mutation accompanied with amino acid change but one was a silent mutation. Of these sequence substitutions, two were present in both tumor and non-tumor liver tissues, suggesting the possibility of polymorphism. The present findings indicate that p31(comet) does not have an impact on the formation of aneuploidy and tetraploidy found in human hepatocellular carcinoma.