Department of Human and Molecular Genetics, VCU Institute of Molecular Medicine, VCU Massey Cancer Center, Virginia Commonwealth University, School of Medicine, Richmond, VA, USA.
J Mol Med (Berl). 2013 Mar;91(3):381-93. doi: 10.1007/s00109-012-0955-3. Epub 2012 Sep 12.
The purpose of this study was to identify key genetic pathways involved in non-small cell lung cancer (NSCLC) and understand their role in tumor progression. We performed a genome wide scanning using paired tumors and corresponding 16 mucosal biopsies from four follow-up lung cancer patients on Affymetrix 250K-NSpI array platform. We found that a single gene SH3GL2 located on human chromosome 9p22 was most frequently deleted in all the tumors and corresponding mucosal biopsies. We further validated the alteration pattern of SH3GL2 in a substantial number of primary NSCLC tumors at DNA and protein level. We also overexpressed wild-type SH3GL2 in three NSCLC cell lines to understand its role in NSCLC progression. Validation in 116 primary NSCLC tumors confirmed frequent loss of heterozygosity of SH3GL2 in overall 51 % (49/97) of the informative cases. We found significantly low (p = 0.0015) SH3GL2 protein expression in 71 % (43/60) primary tumors. Forced overexpression of wild-type (wt) SH3GL2 in three NSCLC cell lines resulted in a marked reduction of active epidermal growth factor receptor (EGFR) expression and an increase in EGFR internalization and degradation. Significantly decreased in vitro (p = 0.0015-0.030) and in vivo (p = 0.016) cellular growth, invasion (p = 0.029-0.049), and colony formation (p = 0.023-0.039) were also evident in the wt-SH3GL2-transfected cells accompanied by markedly low expression of activated AKT(Ser(473)), STAT3 (Tyr(705)), and PI3K. Downregulation of SH3GL2 interactor USP9X and activated ß-catenin was also evident in the SH3GL2-transfected cells. Our results indicate that SH3GL2 is frequently deleted in NSCLC and regulates cellular growth and invasion by modulating EGFR function.
本研究旨在鉴定非小细胞肺癌（NSCLC）中涉及的关键基因途径，并了解其在肿瘤进展中的作用。我们使用 Affymetrix 250K-NSpI 阵列平台对来自四名随访肺癌患者的配对肿瘤和相应的 16 个黏膜活检进行了全基因组扫描。我们发现，位于人类染色体 9p22 上的单个基因 SH3GL2 在所有肿瘤和相应的黏膜活检中最常缺失。我们进一步在大量原发性 NSCLC 肿瘤的 DNA 和蛋白质水平上验证了 SH3GL2 的改变模式。我们还在三个 NSCLC 细胞系中过表达野生型 SH3GL2，以了解其在 NSCLC 进展中的作用。在 116 例原发性 NSCLC 肿瘤中的验证证实，在总共有 51%（49/97）的信息病例中 SH3GL2 存在频繁的杂合性缺失。我们发现 71%（43/60）的原发性肿瘤中 SH3GL2 蛋白表达显著降低（p=0.0015）。在三个 NSCLC 细胞系中过表达野生型（wt）SH3GL2 导致活性表皮生长因子受体（EGFR）表达显著降低，EGFR 内化和降解增加。在 wt-SH3GL2 转染细胞中，体外（p=0.0015-0.030）和体内（p=0.016）细胞生长、侵袭（p=0.029-0.049）和集落形成（p=0.023-0.039）均显著降低，同时 AKT（Ser（473））、STAT3（Tyr（705））和 PI3K 的激活也明显降低。在 SH3GL2 转染细胞中，SH3GL2 相互作用物 USP9X 和激活的 ß-catenin 的下调也很明显。我们的结果表明，SH3GL2 在 NSCLC 中经常缺失，并通过调节 EGFR 功能来调节细胞生长和侵袭。
