Knockdown of RNA binding protein musashi-1 leads to tumor regression in vivo
Knockdown of RNA binding protein musashi-1 leads to tumor regression in vivo
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DOI：
10.1053/j.gastro.2008.02.057
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发表时间：
2008-05-01
期刊：
影响因子：
29.4
通讯作者：
Houchen, Courtney W.
中科院分区：
文献类型：
--
作者：
Sureban, Sripathi M.;May, Randal;Houchen, Courtney W.
背景与目的：在肠道中，肿瘤的发生被认为是由位于肠和结肠隐窝底部附近的干细胞群引起的。RNA结合蛋白Musashi-1(MSI-1)是一种可能的肠道和祖细胞/干细胞标记物。在大鼠脑发育和APC(min/+)小鼠肿瘤中，MSI-1的表达增加。这项研究考察了MSI-1在肿瘤发生中的潜在作用。方法：将MSI-1小干扰RNA(SiRNA)作为脂质体应用于裸鼠HCT116结肠癌移植瘤中，测量肿瘤体积。用氨基己糖苷酶和3-(4，5-二甲基噻唑-2-基)-2，5-二苯基四氮唑溴化法检测细胞增殖。转染siRNA的细胞接受12Gy伽玛射线照射。免疫活性半胱氨酸天冬氨酸氨基转移酶3检测细胞凋亡，组蛋白H3磷酸化检测细胞分裂。移植瘤同样染色为磷酸化组蛋白H3、活化的caspase-3、末端脱氧核苷酸转移酶介导的脱氧尿嘧啶核苷缺口末端标记、Notch-1和p21(WAF1)。细胞周期分析和Western印迹分析Notch-1和p21(WAF1)的表达。结果：MSI-1基因敲除可使移植瘤生长停滞，抑制肿瘤细胞增殖，增加肿瘤细胞凋亡率。SiRNA介导的MSI-1降低导致肿瘤细胞有丝分裂灾难。此外，MSI-1基因被敲除后，Notch-1表达受到抑制，p21(WAF1)表达上调。结论：我们的结果表明MSI-1参与了癌细胞的增殖、抑制凋亡和有丝分裂灾难，提示了它在肿瘤发生中作用的一个重要的潜在机制。
Background & Aims: in the gut, tumorigenesis is thought to arise from the stem cell population located near the base of intestinal and colonic crypts. The RNA binding protein musashi-1 (Msi-1) is a putative intestinal and progenitor/stem cell marker. Msi-1 expression is increased during rat brain development and in APC(min/+) mice tumors. This study examined a potential role of Msi-1 in tumorigenesis. Methods: Msi-1 small interfering RNA (siRNA) was administered as a liposomal preparation to HCT116 colon adenocarcinoma xenografts in athymic nude mice and tumor volume was measured. Cell proliferation was assessed by hexosaminidase and 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium bromide MTT assays. siRNA-transfected cells were subjected to 12 Gy gamma-irradiation. Apoptosis was assessed by immunoreactive activated caspase-3 and mitosis was assessed by phosphorylated histone H3 staining. The tumor xenografts were stained similarly for phosphorylated histone H3, activated caspase-3, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling, Notch-1, and p21(WAF1). Furthermore, siRNA-transfected cells were subjected to cell-cycle analysis and Western blot analyses for Notch-1 and p21(WAF1). Results: Knockdown of Msi-1 resulted in tumor growth arrest in xenografts, reduced cancer cell proliferation, and increased apoptosis alone and in combination with radiation injury. siRNA-mediated reduction of Msi-1 lead to mitotic catastrophe in tumor cells. Moreover, there was inhibition of Notch-1 and up-regulation of p21(WAF1) after knockdown of Msi-1. Conclusions: Our results show the involvement of Msi-1 in cancer cell proliferation, inhibition of apoptosis, and mitotic catastrophe, suggesting an important potential mechanism for its role in tumorigenesis.