MALAT1 silencing suppresses prostate cancer progression by upregulating miR-1 and downregulating KRAS.
MALAT1 silencing suppresses prostate cancer progression by upregulating miR-1 and downregulating KRAS.
复制标题
DOI：
10.2147/ott.s164131
复制
发表时间：
2018
影响因子：
4
通讯作者：
Hou J
中科院分区：
文献类型：
--
作者：
Chang J;Xu W;Du X;Hou J
前列腺癌（PC）是男性癌症相关死亡的第二大原因。长链非编码RNA转移相关肺腺癌转录物1（MALAT 1）在包括PC在内的多种癌症中作为癌基因发挥作用。然而，MALAT 1参与PC进展的分子机制尚未得到彻底阐述。采用逆转录-定量聚合酶链反应（RT-PCR）方法检测MALAT 1和microRNA-1（miR-1）的表达。使用蛋白质印迹法测定裂解的聚（ADP-核糖）聚合酶、裂解的半胱天冬酶-3、BAX、bcl-2和KRAS的蛋白质水平。通过集落形成和MTS测定评估细胞增殖。通过transwell迁移测定（Corning Incorporated，Corning，NY，USA）检查细胞迁移能力。Annexin V-FITC和碘化丙啶双染流式细胞仪检测细胞凋亡率。采用荧光素酶和RNA免疫沉淀法探讨miR-1、MALAT 1和KRAS之间的关系。在PC组织和细胞系中，MALAT 1表达上调，miR-1表达下调。MALAT 1基因敲低可抑制雄激素受体阴性的DU 145和PC 3细胞的增殖和迁移，并促进细胞凋亡。分子机制的探讨揭示MALAT 1在DU 145细胞中充当miR-1的分子海绵。此外，miR-1下调部分废除MALAT 1沉默介导的抗增殖，抗迁移，并在DU 145和PC 3细胞凋亡的影响。进一步的研究表明，KRAS是DU 145细胞中miR-1的靶点。MALAT 1作为miR-1的竞争性内源性RNA，导致DU 145和PC 3细胞中KRAS表达增加。此外，miR-1过表达阻碍了DU 145和PC 3细胞的增殖和迁移，并促进了细胞凋亡，而这些作用在KRAS上调后明显减弱。MALAT 1敲低通过上调miR-1和下调雄激素受体阴性PCa细胞中的KRAS抑制增殖和迁移并促进凋亡，为MALAT 1的分子基础和抑制去势抵抗性PC的潜在生物标志物或治疗靶点提供了新的见解。
Prostate cancer (PC) is the second leading cause of cancer-related deaths among men. Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) performed as an oncogene in multiple cancers including PC. However, the molecular mechanisms of MALAT1 implicated in PC progression have not been thoroughly elaborated. Reverse transcription-quantitative polymerase chain reaction assay was used to detect the expressions of MALAT1 and microRNA-1 (miR-1). Protein levels of cleaved poly (ADP-ribose) polymerase, cleaved caspase-3, BAX, bcl-2, and KRAS were determined using a western blot assay. Cell proliferation was assessed by colony formation and MTS assays. Cell migration capacity was examined by transwell migration assay (Corning Incorporated, Corning, NY, USA). Apoptosis rate was measured by flow cytometry via double staining of annexin V-FITC and propidium iodide. Luciferase and RNA immunoprecipitation assays were employed to explore the relationship among miR-1, MALAT1, and KRAS. MALAT1 expression was upregulated and miR-1 expression was downregulated in PC tissues and cell lines. MALAT1 knockdown inhibited cell proliferation and migration, and promoted cell apoptosis in androgen receptor-negative DU145 and PC3 cells. Molecular mechanism explorations disclosed that MALAT1 acted as a molecular sponge of miR-1 in DU145 cells. Moreover, miR-1 downregulation partly abrogated MALAT1 silencing-mediated anti-proliferative, antimigratory, and proapoptotic effects in DU145 and PC3 cells. Further investigation revealed that KRAS was a target of miR-1 in DU145 cells. MALAT1 acted as a competing endogenous RNA of miR-1, resulting in the increase of KRAS expression in DU145 and PC3 cells. Furthermore, miR-1 overexpression hampered proliferation and migration and promoted apoptosis in DU145 and PC3 cells, while these effects were markedly weakened following KRAS upregulation. MALAT1 knockdown inhibited proliferation and migration and facilitated apoptosis by upregulating miR-1 and downregulating KRAS in androgen receptor-negative PCa cells, providing a new insight into the molecular basis of MALAT1 and a potential biomarker or therapeutic target for suppressing castration-resistant PC.