一个新的抑癌基因 ECRG4 与 TMPRSS11A（ECRG1）直接相互作用，抑制食管癌中的癌细胞生长。

BACKGROUND

The esophageal carcinoma related gene 4 (ECRG4) was initially identified and cloned from human normal esophageal epithelium in our laboratory (GenBank accession no.AF325503). ECRG4 has been described as a novel tumor suppressor gene associated with prognosis in esophageal squamous cell carcinoma (ESCC).

METHODS

In this study, binding affinity assay in vitro and co-immunoprecipitation experiment in vivo were utilized to verify the physical interaction between ECRG4 and transmembrane protease, serine 11A (TMPRSS11A, also known as ECRG1, GenBank accession no. AF 071882). Then, p21 protein expression, cell cycle and cell proliferation regulations were examined after ECRG4 and ECRG1 co-transfection in ESCC cells.

RESULTS

We revealed for the first time that ECRG4 interacted directly with ECRG1 to inhibit cancer cell proliferation and induce cell cycle G1 phase block in ESCC. Binding affinity and co-immunoprecipitation assays demonstrated that ECRG4 interacted directly with ECRG1 in ESCC cells. Furthermore, the ECRG4 and ECRG1 co-expression remarkably upregulatd p21 protein level by Western blot (P < 0.001), induced cell cycle G1 phase block by flow cytometric analysis (P < 0.001) and suppressed cell proliferation by MTT and BrdU assay (both P < 0.01) in ESCC cells.

CONCLUSIONS

ECRG4 interacts directly with ECRG1 to upregulate p21 protein expression, induce cell cycle G1 phase block and inhibit cancer cells proliferation in ESCC.

背景

食管癌细胞相关基因 4（ECRG4）最初是在我们实验室从人正常食管上皮中鉴定和克隆出来的（GenBank 登录号：AF325503）。ECRG4 被描述为与食管鳞状细胞癌（ESCC）预后相关的新型肿瘤抑制基因。

方法

在这项研究中，我们利用体外结合亲和力测定和体内共免疫沉淀实验验证了 ECRG4 与跨膜蛋白酶丝氨酸 11A（TMPRSS11A，也称为 ECRG1，GenBank 登录号：AF071882）之间的物理相互作用。然后，在 ESCC 细胞中转染 ECRG4 和 ECRG1 后，检测了 p21 蛋白表达、细胞周期和细胞增殖的调节。

结果

我们首次揭示了 ECRG4 与 ECRG1 直接相互作用，抑制 ESCC 中癌细胞的增殖并诱导细胞周期 G1 期阻滞。结合亲和力和共免疫沉淀实验表明，ECRG4 与 ESCC 细胞中的 ECRG1 直接相互作用。此外，Western blot 检测结果显示，ECRG4 和 ECRG1 的共表达显著上调了 p21 蛋白水平（P<0.001），通过流式细胞术分析诱导细胞周期 G1 期阻滞（P<0.001），并通过 MTT 和 BrdU 检测抑制 ESCC 细胞增殖（均 P<0.01）。