Invasion of ovarian cancer cells is induced byPITX2-mediated activation of TGF-β and Activin-A.
Invasion of ovarian cancer cells is induced byPITX2-mediated activation of TGF-β and Activin-A.
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DOI：
10.1186/s12943-015-0433-y
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发表时间：
2015-08-23
期刊：
影响因子：
37.3
通讯作者：
Roy SS
中科院分区：
文献类型：
--
作者：
Basu M;Bhattacharya R;Ray U;Mukhopadhyay S;Chatterjee U;Roy SS
大多数卵巢癌具有高度侵袭性，转移性疾病的高负担使其成为所有妇科恶性肿瘤中导致死亡的主要原因。同源结构域转录因子PITX2在不同组织中与癌症相关。我们之前的研究表明，PITX2在人类卵巢肿瘤中的表达增加。越来越多的证据表明TGF-β通路通过同质结构域蛋白激活，这促使我们寻找该信号通路在pitx2介导的卵巢癌进展中的可能参与。免疫组化法检测TGF-β信号在人卵巢组织中的表达状况。用克隆/试剂转染/处理正常/癌细胞后，采用定量pcr （Q-PCR）和Western Blot检测TGFB/INHBA等侵袭相关基因的表达水平。采用matrigel侵袭和创面愈合实验检测PITX2对侵袭/运动的生理影响。采用Q-PCR和细胞共聚焦/相衬成像技术评价PITX2和激活素诱导的上皮-间质转化（EMT）。人卵巢肿瘤显示TGF-β信号增强。我们的研究揭示了pitx2诱导TGFB1/2/3和INHBA基因的表达（p < 0.01），随后是smad2 /3依赖性TGF-β信号通路。pitx2诱导的TGF-β通路调节侵袭相关基因SNAI1、CDH1和MMP9的表达（p < 0.01），这些基因与卵巢癌的运动/侵袭增强有关。Snail和MMP9是pitx2诱导卵巢癌细胞侵袭的重要介质。PITX2过表达导致上皮标记物的缺失（p < 0.01）和间充质标记物的增加（p < 0.01），这些标记物与卵巢肿瘤的发生有显著关系。pitx2诱导的INHBA表达（p < 0.01）促进了正常和卵巢癌细胞的EMT。总之，我们的研究结果表明PITX2通过上调TGFB/INHBA在促进卵巢癌细胞侵袭行为中起着重要的促进作用。我们还发现了激活素- a在促进EMT中先前未知的参与。我们的工作为卵巢癌细胞的侵袭行为提供了新的机制见解。本研究的扩展在未来具有治疗应用的潜力。本文的在线版本（doi:10.1186/s12943-015-0433-y）包含补充材料，仅供授权用户使用。
Most ovarian cancers are highly invasive in nature and the high burden of metastatic disease make them a leading cause of mortality among all gynaecological malignancies. The homeodomain transcription factor, PITX2 is associated with cancer in different tissues. Our previous studies demonstrated increased PITX2 expression in human ovarian tumours. Growing evidence linking activation of TGF-β pathway by homeodomain proteins prompted us to look for the possible involvement of this signalling pathway in PITX2-mediated progression of ovarian cancer. The status of TGF-β signalling in human ovarian tissues was assessed by immunohistochemistry. The expression level of TGFB/INHBA and other invasion-associated genes was measured by quantitative-PCR (Q-PCR) and Western Blot after transfection/treatments with clones/reagents in normal/cancer cells. The physiological effect of PITX2 on invasion/motility was checked by matrigel invasion and wound healing assay. The PITX2- and activin-induced epithelial-mesenchymal transition (EMT) was evaluated by Q-PCR of respective markers and confocal/phase-contrast imaging of cells. Human ovarian tumours showed enhanced TGF-β signalling. Our study uncovers the PITX2-induced expression of TGFB1/2/3 as well as INHBA genes (p < 0.01) followed by SMAD2/3-dependent TGF-β signalling pathway. PITX2-induced TGF-β pathway regulated the expression of invasion-associated genes, SNAI1, CDH1 and MMP9 (p < 0.01) that accounted for enhanced motility/invasion of ovarian cancers. Snail and MMP9 acted as important mediators of PITX2-induced invasiveness of ovarian cancer cells. PITX2 over-expression resulted in loss of epithelial markers (p < 0.01) and gain of mesenchymal markers (p < 0.01) that contributed significantly to ovarian oncogenesis. PITX2-induced INHBA expression (p < 0.01) contributed to EMT in both normal and ovarian cancer cells. Overall, our findings suggest a significant contributory role of PITX2 in promoting invasive behaviour of ovarian cancer cells through up-regulation of TGFB/INHBA. We have also identified the previously unknown involvement of activin-A in promoting EMT. Our work provides novel mechanistic insights into the invasive behavior of ovarian cancer cells. The extension of this study have the potential for therapeutic applications in future. The online version of this article (doi:10.1186/s12943-015-0433-y) contains supplementary material, which is available to authorized users.