Tamura Kenji, Furihata Mutsuo, Satake Hirofumi, Hashida Hatsune, Kawada Chiaki, Osakabe Hiroto, Fukuhara Hideo, Kumagai Naoko, Iiyama Tatsuo, Shuin Taro, Inoue Keiji
Department of Urology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan.
Department of Pathology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan.
Oncol Lett. 2017 Dec;14(6):6650-6658. doi: 10.3892/ol.2017.7099. Epub 2017 Sep 28.
The present study aimed at identifying novel molecular cancer drug targets and biomarkers by analyzing the gene expression profiles of high-grade prostate cancer (PC), using a cDNA microarray combined with laser microbeam microdissection. A number of genes were identified that were transactivated in high-grade PC. First, a novel molecular target and diagnostic biomarker, shisa family member 2 (), was identified as an overexpressed gene in high-grade PC cells. The reverse transcription-semi-quantitative polymerase chain reaction and immunohistochemical analysis validated the overexpression of SHISA2 (295 amino acids in length), specifically in high-grade PC cells with Gleason scores of between 8 and 10, relative to normal prostate epithelium. Knockdown of expression by short interfering RNA resulted in the marked suppression of PC cell viability. By contrast, exogenous expression in transfected cells promoted PC cell proliferation, indicating its oncogenic effects. Notably, as a result of cDNA microarray analysis, protein Wnt-5a (WNT5A) was focused upon and the expression of WNT5A was identified to be downregulated in SHISA2-knockdown. Western blot analysis validated significant downregulation of WNT5A by SHISA2-knockdown and upregulation of WNT5A by SHISA2 overexpression. The results of the present study indicated that SHISA2 may affect WNT5A synthesis. Furthermore, the secreted SHISA2 protein was determined in the culture medium of PC cells. We hypothesize that SHISA2 is involved in the regulation of WNT5A and in the aggressiveness of PC via the Wnt signaling pathway through WNT5A. Furthermore, SHISA2 may be a molecular target for cancer drugs, and a useful diagnostic biomarker for the prognosis and therapeutic effect in cancer.
本研究旨在通过使用cDNA微阵列结合激光微束显微切割技术分析高级别前列腺癌（PC）的基因表达谱，以鉴定新的分子癌症药物靶点和生物标志物。鉴定出了一些在高级别PC中被反式激活的基因。首先，一种新的分子靶点和诊断生物标志物，即希萨家族成员2（SHISA2），被鉴定为在高级别PC细胞中过表达的基因。逆转录-半定量聚合酶链反应和免疫组织化学分析证实了SHISA2（长度为295个氨基酸）的过表达，特别是相对于正常前列腺上皮，在Gleason评分为8至10的高级别PC细胞中。通过短干扰RNA敲低SHISA2的表达导致PC细胞活力的显著抑制。相比之下，转染细胞中外源SHISA2的表达促进了PC细胞增殖，表明其致癌作用。值得注意的是，作为cDNA微阵列分析的结果，蛋白Wnt-5a（WNT5A）受到关注，并且WNT5A的表达在SHISA2敲低时被鉴定为下调。蛋白质印迹分析证实了通过敲低SHISA2导致WNT5A显著下调，以及通过过表达SHISA2导致WNT5A上调。本研究结果表明，SHISA2可能影响WNT5A的合成。此外，在PC细胞的培养基中检测到了分泌的SHISA2蛋白。我们假设SHISA2通过WNT5A参与Wnt信号通路对WNT5A的调节以及PC的侵袭性。此外，SHISA2可能是癌症药物的分子靶点，以及癌症预后和治疗效果的有用诊断生物标志物。
