Yang Kun, Chen Xin-Zu, Zhang Bo, Yang Chen, Chen Hai-Ning, Chen Zhi-Xin, Zhou Zong-Guang, Chen Jia-Ping, Hu Jian-Kun
Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan Province - P.R. China.
Int J Biol Markers. 2011 Jul-Sep;26(3):173-80. doi: 10.5301/JBM.2011.8551. Epub 2011 Jul 22.
CD133 has been used to identify normal and cancer stem cells from several different tissues. Nowadays some researchers have reported that CD133 expression was not restricted to cancer stem cells (CSCs) of colorectal cancer and brain tumors, and CD133-negative subsets could also initiate tumors. We therefore performed a meta-analysis to assess the value of CD133 as a biomarker of CSCs for colorectal cancer and brain tumors.
A Medline search was performed to identify relevant studies for the analysis. The meta-analysis was done using RevMan 5.0 software. Outcome measures were colony formation rate and xenotransplanted tumor formation rate.
Fifteen identified studies were available for analysis. For in vitro tests, there were no significant differences in the colony formation rates between CD133-positive and CD133-negative cells for colorectal cancer and brain tumors. For in vivo tests, the xenotransplanted tumor formation rate showed a significant difference between CD133-positive cells and CD133-negative cells in colorectal cancer only, corresponding to a risk difference of 0.40 (95%CI: 0.07, 0.73). Samples (cell lines versus tissues), applied biomarkers (combined versus single), and injection site were included as factors in sensitivity analyses, but the results were very inconsistent.
CD133 may not be suitable as a universe biomarker in identifying CSCs of colorectal cancer and brain tumors. Additional studies are necessary to further delineate its role.
CD133已被用于从多种不同组织中识别正常干细胞和癌症干细胞。如今，一些研究人员报告称，CD133的表达并不局限于结直肠癌和脑肿瘤的癌症干细胞（CSCs），CD133阴性亚群也可引发肿瘤。因此，我们进行了一项荟萃分析，以评估CD133作为结直肠癌和脑肿瘤CSCs生物标志物的价值。
进行Medline检索以识别相关研究用于分析。使用RevMan 5.0软件进行荟萃分析。观察指标为集落形成率和异种移植肿瘤形成率。
共纳入15项已识别的研究进行分析。对于体外试验，结直肠癌和脑肿瘤的CD133阳性细胞与CD133阴性细胞之间的集落形成率无显著差异。对于体内试验，仅在结直肠癌中，CD133阳性细胞与CD133阴性细胞之间的异种移植肿瘤形成率存在显著差异，风险差为0.40（95%CI：0.07，0.73）。样本（细胞系与组织）、应用的生物标志物（联合与单一）和注射部位作为敏感性分析的因素，但结果非常不一致。
CD133可能不适宜作为识别结直肠癌和脑肿瘤CSCs的通用生物标志物。需要进一步的研究来进一步阐明其作用。
