食管鳞癌分泌素-3A1基因启动子甲基化异常

Secretoglobin-3A1 Gene Promoter Hypermethylation Relevant to Esophageal Squamous Cell Carcinoma

目的研究具有抗癌活性的细胞因子分泌素-3A1基因启动子超甲基化所致该基因表达抑制在我国食管鳞癌发生中的作用。方法用RT-PCR方法检测分泌素-3A1基因在12个食管鳞癌细胞系的表达,并用甲基化特异PCR技术(methylation specific PCR,MSP)检测上述细胞系及37例来自我国河南的原发性食管鳞癌标本分泌素-3A1基因启动子甲基化状态,通过5-aza-dc处理使培养细胞去甲基化,RT-PCR技术检测处理后该基因在Kyse30的重新表达。结果该基因仅在Kyse410、Kyse520和TE8等3个细胞系有表达,5-aza-dc处理可使Kyse30重新表达分泌素-3A1。此外,在18/37(48.6%)例原发性食管鳞癌细胞有分泌素-3A1基因启动子区域的超甲基化。结论启动子超甲基化造成分泌素-3A1基因在上述食管鳞癌细胞系表达抑制,原发性食管鳞癌细胞分泌素-3A1基因启动子超甲基化提示该基因表达抑制可能与食管鳞癌发生有关。

Objective To study the involvement of promoter region hypermethylation related loss of gene expression of Secretoglobin-3A1 （SCGB3A1）, a cytokine with tumor suppressing activity, in the tumorigenesis of oesophageal squmous cell carcinoma （ESCC）. Methods RT-PCR was used to detect SCGB3A1 expression in 12 cell lines derived from human ESCC; methylation specific PCR （MSP） was used to test the methylation statue of SCGB3A1 gene＇s.promoter region CpG island in those ESCC cell lines and 37 primary ESCC specimen from Henan China. DNA de-methylation regent 5-aza-dc was also used to treat the SCGB3A1 silencing cell line in vitro. Results Only Kyse410, Kyse520 and TE8 from 12 tested cell lines had detectable SCGB3A1 gene expression. As revealed by using MSP, SCGB3A1 gene silencing was associated with the hypermethylation state throughout its promoter region, which was further confirmed by the detection of SCGB3A1 gene re-expression in Kyse30, after in vitro de-methylation treat- ment with 5-aza-dc. Moreover, we found that 18/37 （48.6%） of primary ESCC specimens tested had a high density of methylated CpG in SCGB3A1 promoter region. Conclusion Data here suggest promoter-hypermethylation related loss of SCGB3A1 gene expression is relevant to ESCC.