Aquaporin expression in breast cancer and their involvement in bleb formation, cell motility and invasion in endocrine resistant variant cells
Aquaporin expression in breast cancer and their involvement in bleb formation, cell motility and invasion in endocrine resistant variant cells
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DOI：
10.3892/ijo.2020.4976
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发表时间：
2020-04-01
影响因子：
5.2
通讯作者：
Luqmani, Yunus A.
中科院分区：
文献类型：
--
作者：
Ahmad, Ayah E.;Khajah, Maitham A.;Luqmani, Yunus A.
雌激素受体（ER）沉默的乳腺癌细胞系表现出内分泌抵抗和从上皮细胞到间充质细胞表型的形态学变化。这些细胞还显示出增加的运动性和侵入性，其通过暴露于碱性pH进一步加重，表现出动态质膜起泡和细胞质流动。这些后一种形态学变化被假设为涉及大量的水穿过质膜的运动，有助于水泡的形成;这可能涉及水通道蛋白（AQP）。AQP 1，3，4和5的表达/定位通过逆转录定量PCR，蛋白质印迹和共聚焦显微镜检查内分泌敏感（YS 1.2）和耐药（pII和MDA-MB-231）乳腺癌细胞，以及正常乳腺上皮细胞（MCF 10A）。通过活细胞成像检查渗透压变化对滤过泡形成的影响。用小干扰RNA（siRNA）转染法下调AQP 3蛋白表达，免疫荧光法、划痕法和Cultrex法检测AQP 3蛋白表达下调对滤过泡形成、细胞运动和侵袭的影响。四种AQPs在不同细胞系中的表达不同，并表现出核、胞质和膜定位。渗透压的改变影响了滤过泡的形成。在pII细胞暴露于碱性pH值，AQP 3被观察到重新分配到新形成的水泡从核。siRNA介导的pII细胞中AQP 3的敲低显著减少了碱性pH诱导的细胞起泡，以及运动性和侵袭性。这些数据表明，AQP 3和潜在的其他水通道蛋白可能参与导致内分泌抗性细胞起泡的过程，这被认为是驱动肿瘤转移的机制。
Estrogen receptor (ER)-silenced breast cancer cell lines exhibit endocrine resistance and morphological changes from an epithelial to a mesenchymal phenotype. These cells also display increased motility and invasive properties that are further accentuated by exposure to an alkaline pH, exhibiting dynamic plasma membrane blebbing and cytoplasmic streaming. These latter morphological changes are hypothesized to involve substantial water movement across the plasma membrane, contributing to bleb formation; this may involve aquaporin channel proteins (AQPs). AQP 1, 3, 4 and 5 expression/localization was examined via reverse transcription-quantitative PCR, western blotting and confocal microscopy in endocrine-sensitive (YS1.2) and -resistant (pII and MDA-MB-231) breast cancer cells, as well as normal breast epithelial cells (MCF10A). The effects of osmotic changes on bleb formation were examined via live cell imaging. AQP3 protein expression was knocked down by small interfering RNA (siRNA) transfection, and the effect of its reduced expression on bleb formation, cell motility and invasion were determined via immunofluorescence, scratch and Cultrex assays, respectively. Expression of the four AQPs varied across the different cell lines, and exhibited nuclear, cytoplasmic and membranous localization. Osmotic changes affected the formation of blebs. In pII cells exposed to alkaline pH, AQP3 was observed to be redistributed from the nucleus into the newly formed blebs. siRNA-mediated knockdown of AQP3 in pII cells significantly reduced cellular blebbing induced by alkaline pH, as well as motility and invasion. These data suggested that AQP3, and potentially other aquaporins, may participate in the processes leading to blebbing of endocrine-resistant cells which is proposed to be a mechanism that drives tumor metastasis.