| Backgroud:Cervical cancer is the most common genital tract malignancy in women,and its mortality rate ranks the second among female malignancy.At present,persistent infection with human papillomavirus(HPV)is considered to be the most important risk factor for cervical cancer.Secondly,the occurrence of cervical cancer is also related to genetic,immune and environmental factors.The main cause of death in patients with cervical cancer is intrauterine invasion and metastasis.Therefore,it is of great significance to study the mechanism of occurrence and development of susceptible cervical cancer,find effective therapeutic targets,make early diagnosis of cervical cancer,and prevent invasion and metastasis of tumor to improve the prognosis of patients.Long non-coding RNA(lncRNAs)is a kind of non-coding RNA with transcript length greater than 200 nt.Lnc RNA is dysregulated in a variety of tumors and is involved in cell proliferation,migration,apoptosis,invasion,cell cycle,and metastasis,etc.It plays a role in promoting or inhibiting cancer to regulate the occurrence and development of tumors.Human maternally expressed gene 3(MEG3)is an imprinted gene on dlk1-meg3 located on human chromosome 14q32.3.At present,lncRNA MEG3 gene has been found to be underexpressed in a variety of cancer tissues,which is a potential tumor suppressor.Objectives:The purpose of this study was to investigate the expression of MEG3 in cervical cancer tissues and analyze its relationship with clinicopathology and prognosis.The effects of MEG3 on the proliferation,migration and invasion of cervical cancer cells were studied after MEG3 was overexpressed in vitro.Finally,the potential targets of mutual regulation are further studied.Methods:1.A total of 68 patients with cervical cancer who underwent surgical treatment in the gynecology department of the people’s hospital of guangxi zhuang autonomous region from July 2012 to December 2018 were collected,and another 30 patients with normal cervical tissue were selected as the control group.Quantitative real time polymerase chain reaction(qrt-pcr)technology was used to detect the expression of MEG3 mRNA in cervical tissue,and the relationship between the expression of MEG3 and the clinicopathological parameters and prognosis of cervical cancer patients was analyzed.2.The proliferation of cells was detected by cck-8 assay using MEG3-overexpressed cervical cancer cell lines and cell lines interfering with MEG3 expression.The Trans Well cell migration assay was used to detect the migration ability of cells,and the Trans Well cell invasion assay was used to detect the invasion ability of cervical cancer cells.3.Bioinformatics was used to predict the potential binding sites of MEG3 to mir-9.The expression of mir-9 mRNA in the cervical tissue samples was detected by qRT-PCR,and the relationship between mir-9 expression and prognosis was analyzed during follow-up.The expression of MEG3 and mir-9 in cervical cancer tissues was statistically correlated.The effect of overexpression of MEG3 on the expression of mir-9 in cervical cancer cell lines was detected in vitro.Results:1.The relative expression of MEG3 in cervical cancer tissues detected by qRT-PCR was lower than that in normal cervical tissues,and the difference between the two groups was statistically significant(P<0.001).In cervical cancer tissues,low expression of MEG3 was associated with low tumor differentiation,late FIGO stage,> 1/2 of invasion depth,and lymphatic metastasis(all P < 0.05).In addition,the median survival time of those with low expression of MEG3 and high expression in cervical cancer tissues was shorter.2.In the cell function experiment,the cell proliferation,invasion and migration capacity of Hela and Siha cells after overexpression of MEG3 was significantly lower than that of the negative control group and the blank control group.On the contrary,the cell proliferation,invasion and migration capacity of Hela and Siha cells after interfering with MEG3 expression was significantly higher than that of the negative control group and the blank control group.The differences were statistically significant(P<0.05).3.Bioinformatics analysis showed that MEG3 had potential binding sites with miR-9,and it was predicted that miR-9 might be the target gene of MEG3.4.The relative expression of miR-9 in cervical cancer tissues detected by qRT-PCR was higher than that in normal cervical tissues,and the difference was statistically significant(P<0.001).Moreover,the median survival time of patients with high expression of miR-9 and low expression of mir-9 was shortened,and the difference was statistically significant(P<0.05).The correlation between MEG3 and miR-9 mRNA expression in cervical cancer tissues was analyzed by Spearman method,and the correlation coefficient was-0.753,P<0.001,a statistically significant difference.5.There was a negative correlation between MEG3 and miR-9 expression in cervical cancer tissues,with a correlation coefficient of-0.753 and a statistical difference of P<0.001.MEG3 was overexpressed in HeLa and SiHa cells,and the expression of mir-9 in the cells decreased.Conclusions:1.The expression of MEG3 mRNA in cervical cancer tissues is down-regulated,which is related to the degree of tumor differentiation,depth of invasion,lymph node metastasis and prognosis.2.MEG3 can inhibit the proliferation,invasion and migration of HeLa and SiHa cells of cervical cancer,and may play a role as a tumor suppressor gene in cervical cancer.3.Bioinformatics predicts that MEG3 has potential binding sites with miR-9.The expressions of MEG3 and miR-9 in cervical cancer tissues were negatively correlated and correlated with the prognosis of the patients.Overexpression of MEG3 in vitro can down-regulate the expression of miR-9 in cervical cancer cells.MiR-9 may be a target of MEG3,and MEG3 may play a role in the occurrence and development of cervical cancer through the regulation of downstream gene expression through competitive combination with miR-9,but its specific mechanism still needs further study. |
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