TY - JOUR T1 - Late-breaking abstract: Relationship of aquaporin 1, 3 and 5 expression in lung cancer cells to cellular differentiation, invasive growth and metastasis potential JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - 384 AU - Miyako Shimasaki AU - Yuichiro Machida AU - Yutaka Takahara AU - Hirohisa Toga AU - Yoshimichi Ueda Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/384.abstract N2 - An oncogenic capacity of aquaporins (AQPs), transmembrane channels for water, was recently proposed. This study seeks to elucidate the involvement of AQP1, 3 and 5 in the development and progression of lung cancer. Expression analyses of AQP1, 3 and 5 by immunohistochemistry, western blot and real time RT-PCR in 160 lung cancers showed that AQP1, 3 and 5 were expressed in tumor cells of 71, 40 and 56%, of lung cancers, respectively. AQPs expressions were frequent in adenocarcinomas (ADCs), while AQP1 and 5 were negative in squamous cell carcinomas. Bronchioloalveolar carcinoma (BAC) cells exhibited an apicolateral AQP1 and apicolateral or basolateral AQP3 localization in non-mucinous type, and apical AQP1 and 5 and basolateral AQP3 expression in mucinous type, which corresponded to AQPs expression of non-neoplastic lung tissue. Basolateral AQP5 expression was acquired during tumorigenesis of non-mucinous BAC. In contrast, invasive ADC tumor cells, either with fibroblastic reaction or papillary growth in the alveolar space, overexpressed AQP1 and 5 with loss of subcellular polarization and with an intracytoplasmic distribution. Overexpression of AQP1 correlated with high postoperative ADC metastasis ratios and unfavorable disease-free survival rates (p=0.031). We conclude that expression patterns of AQP1, 3 and 5 in lung cancer cells are mostly associated with cellular differentiation. However, the expression of AQP1 and 5 is up-regulated in invading lung cancer cells, particularly in ADCs, and the overexpression of AQP1 with loss of subcellular polarization is suggested to be involved in their invasive and metastatic potential. ER -