Identification and cloning of human G-protein γ 7, down-regulated in pancreatic cancer
Identification and cloning of human G-protein γ 7, down-regulated in pancreatic cancer
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DOI：
10.1006/bbrc.1998.8581
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发表时间：
1998-05-08
影响因子：
3.1
通讯作者：
Akiyoshi, T
中科院分区：
文献类型：
--
作者：
Shibata, K;Mori, M;Akiyoshi, T
应用差异显示技术研究胰腺癌组织和正常胰腺组织中差异表达的基因。因此，我们鉴定了在正常组织中表达但在癌组织中很少表达的cDNA片段。从正常胰腺组织制备的cDNA文库中，通过快速扩增cDNA末端（5'RACE）筛选该cDNA，克隆并测序了859bp的cDNA，发现推断的氨基酸序列编码一个G蛋白γ亚基，与牛G蛋白γ 7具有98%的同源性，与人G蛋白γ 7完全同源。用北方印迹法证实了G蛋白γ 7在12例胰腺恶性肿瘤中的表达降低，其中包括9例导管细胞癌、2例囊腺癌和1例母细胞瘤。逆转录聚合酶链反应（RT PCR）检测结果显示，6个胰腺癌细胞系中有5个和2个胰腺癌组织中G蛋白γ 7均不表达。免疫组化分析也显示正常组织中的阳性染色，而癌组织中无染色。结果表明，人G蛋白γ 7的表达减少或抑制可能在胰腺癌的发生中起重要作用。(C)北京：科学出版社.
Differentially expressed genes between normal and cancer tissues of the pancreas were investigated using differential display. Consequently, we identified a fragment cDNA that was expressed in the normal tissue but was rarely expressed in the cancer tissue. This cDNA was screened in cDNA library prepared from the normal pancreatic tissue by rapid amplification of cDNA ends (5'RACE), 859 bp of cDNA was cloned and sequenced, and the inferred amino acid sequence was found to encode a G protein gamma subunit with 98% homology to cow G protein gamma 7 and complete homology to human G protein gamma 7. The decreased expression of the G protein gamma 7 was confirmed by Northern blot assay in twelve pancreatic malignancies which included nine duct cell carcinomas, two cystoadenocarcinomas and one blastoma. Reverse transcriptase (RT) polymerase chain reaction (PCR) assay showed no expression of G protein gamma 7 in five of six pancreatic carcinoma cell lines and two pancreatic cancer tissues. Immunohistochemistry analysis also displayed positive staining in the normal tissue but no staining in the cancer tissue. The findings demonstrated that the reduced or suppressed expression of human G-protein gamma 7 may play an important role in pancreatic carcinogenesis. (C) 1998 Academic Press.