Jarid1b Inhibits Cell Proliferation And Facilitates Differentiation In KYSE-150

Objective: Histone methylation is one of the most important modification methods after chromatin translation.The changes of histone methylation state are involved in a variety of pathological and physiological processes.KDM5B(histone lysine demethylase 5B gene is also named Jarid1 b or PLU-1)encoding the specific demethylase of the fourth lysine of Histone H3(H3K4)act out strong transcriptional inhibition activity.KDM5 B plays an important role in cell differentiation,self-renewal of stem cells and other biological processes.Recent studies have shown that expression of KDM5 B is significantly increased in breast cancer,cholangiocarcinoma,lung cancer,prostate cancer,and many other malignancies,and it can strongly promote the occurrence,development,invasion and metastasis of tumor.However,some studies suggest that the expression of Jarid1 b in certain tumors has decreased,suggesting that it may play a role in tumor suppressor genes.So Jarid1b’s role in cancer remains controversial.The study of the effect of methylase Jarid1 b on the proliferation and differentiation of esophageal squamous cell may provide a new target for the transformation therapy of esophageal squamous cell carcinoma.Methods: RT-PCR and Western-blot(The method of protein immunoimprinting)were used to detect the expression of demethylation enzyme Jarid1 b and cytokeratin(KRT10 and KRT13)in poorly differentiated esophageal squamous cell carcinoma cell lines(KYSE-150)and highly differentiated esophageal squamous cell carcinoma cell lines(TE-1).Lentiviral infection and specific drugs(puromycin)were used to obtain the low-differentiated esophageal squamous cell carcinoma KYSE-150 cell lines which can stably express Jarid1b(The cell line cannot express Jarid1 b in normal cell culture conditions,and only when the cumate reagent is used it can recover the activity).The expression of Jarid1 b in kyse-150 cells was induced by cumate reagent with appropriate concentration.Then the effect of Jarid1 b on proliferation of the cell line was detected by CCK8 cytotoxicity test.And RT-PCR and Western-blot was performed to detect the expression of cytokeratin(KRT10 and KRT13)in this cell line.Results: RT-PCR and Western-blot data showed that Jarid1 b,KRT10 and KRT13 were highly expressed in highly differentiated TE-1 cells compared with poorly differentiated KYSE-150 cells(P<0.05).KYSE-150 cell lines which can stably express Jarid1 b when reduced by cumate was obtained via Lentiviral infection and screening of specific drugs.The results of CCK8 showed that compared with the control group,the proliferation of KYSE-150 cells decreased significantly when the expression of Jarid1 b was up-regulated(P<0.01).The results of RT-PCR and Western-blot showed that the expression of cytokeratin KRT10 and KRT13 was significantly higher than that of the control group after overexpression of Jarid1 b in KYSE-150 cells(P<0.05).Conclusion: 1.There were significant differences in the expression levels of Jarid1 b,cytokeratin KRT10 and KRT13 in low-differentiated esophageal squamous cell carcinoma(KYSE-150)and highly differentiated esophageal squamous cell lines(TE-1).2.overexpression of Histone H3K4 specific demethylase Jarid1 b can inhibit the proliferation of poorly differentiated esophageal squamous carcinoma cell(KYSE-150)and promote its differentiation.