The Effect And Mechanism Of Small Nucleolar RNA Host Gene 6regulating Esophageal Squamous Cell Carcinoma Cell Proliferation And Apoptosis

Background:During the past decades,esophageal cancer has been one of the leading causes of death in patients with malignancies.It is urgent to explore the undergoing molecular mechanism to improve the prognosis of patients.Recently,non-coding RNAs,especially long-chain non-coding RNAs(Long non-coding non-coding RNA-SNHG6(small nucleolar RNA host gene 6)have been found to play important roles in the occurrence,development and metastasis of malignant tumors.The small nucleolar RNA host gene 6 has been identified as a potential oncogene,while there is little information about the function and mechanism of SNHG6 in esophagus cancer.Objective:This study aims to demonstrate the correlation between the expression level of SNHG6 with the occurrence,development and prognosis of esophageal squamous cell carcinoma(ESCC),and clarify the role and molecular mechanism of SNHG6 in esophageal squamous cell carcinoma,also provide necessary basic data for clinical improvement of the prognosis of esophageal squamous cell carcinoma patients.Methods:(1)To collect the expression levels of SNHG6 in esophageal cancer in Ualcan database,and analyze the correlation between the expression level of SNHG6 and the occurrence of esophageal squamous cell carcinoma.(2)To detect the expression levels of SNHG6 in 70 paired tumor-adjacent tissues by q PCR,and confirm the correlation between the expression level of SNHG6 and the occurrence of esophageal squamous cell carcinoma,also analyze the correlation between SNHG6 expression and clinical parameters.(3)To detect the expression levels of SNHG6 in ECA-109,TE-1,and HEEC esophageal squamous cell lines by q PCR;To analyze the expression and location of SNHG6 in cytosol and nucleus by isolating subcellular organisms.(4)To confirm the expression level of SNHG6 with si-SNHG6(vs.si-vector)in ECA-109,and TE-1 cells;To detect the effect of SNHG6 knockdown on cell proliferation via MTT and colony formation assay,and that on apoptosis by flow cytometry.(5)To confirm the expression level of SNHG6 with SNHG6 expressing plasmid(vs.vector)in ECA-109,and TE-1 cells;To detect the effect of SNHG6 overexpression on cell proliferation via MTT and colony formation assay,and that on apoptosis by flow cytometry.(6)To identify the effect of SNHG6 on P21 expression by q PCR and western blot.(7)To identify the role of P21 in SNHG6 regulated esophageal squamous cell proliferation and apoptosis in rescue experiments.(8)To assess the effect of SNHG6 on esophageal squamous cell tumorigenesis and P21 expression level in vivo.Results:(1)The expression of SNHG6 in esophageal squamous cell carcinoma tissues was significantly higher than that in normal tissues by analyzing the data in Ualcan database(p < 0.05).(2)The results of q PCR showed that upregulated expression of SNHG6 in ESCC tissues,compared to paired adjacent tissues,which is consistent with that in database,indicating that high expression of SNHG6 might play potential roles in ESCC development.(3)We explore the role of SNHG6 in determining the clinical significance of ESCC patients by analyzing the correlation between SNHG6 expression and clinical features.Figures showed that SNHG6 expression was correlated with tumor size(p=0.040)and TNM stage(p<0.01),whereas it was not associated with other parameters,including age(p=0.449),sex(p=0.451),smoking(p=0.880),or drinking(p=0.508).(4)SNHG6 locates both in cytosol and nucleus,and the expression of SNHG6 in cytosol is much higher than that in nucleus in ECA-109 and TE-1 cell lines,indicating that majority of SNHG6 locates in cytosol.(5)MTT results demonstrated that the proliferation of ECA-109/TE-1 cells was dominantly inhibited by knockdown of SNHG6,while increased with SNHG6 overexpression.The results of colony formation were consistent with MTT results.(6)The results of flow cytometry appeared that SNHG6 knockdown induced ESCC cells apoptosis,while SNHG6 overexpression reduced ESCC cells apoptosis,indicating that SNHG6 play multi roles not only in regulating ESCC cell proliferation,but also apoptosis.(7)P21 could eliminate the effect of SNHG6 on ESCC proliferation and apoptosis,which indicated that SNHG6 might regulate ESCC proliferation and apoptosis through P21.(8)SNHG6 overexpression increased ESCC tumorigenesis and blocked P21 expression dominantly in vivo.Conclusion:SNHG6 is increased in esophageal squamous cell carcinoma,and related to tumor size and TNM staging,indicating that SNHG6 is a poor prognosis biomarker in ESCC.SNHG6 could regulate ESCC formation and proliferation both in vivo and in vitro.This reminded us of the critical role of SNHG6 in tumorigenesis and progression of ESCC,and P21 may be involved in the proliferation and apoptosis of esophageal carcinoma by SNHG6.This critical lnc RNA may have a profound impact on the occurrence and development of esophageal cancer,which will bring us a new diagnostic and therapeutic target for esophageal cancer.