Expression And Significance Of Aquaporin-1 And Microvessel Density In Non-small Cell Lung Cancer

Objectice: Angiogenesis and ability of cell migration play an important role in the growth progression and metastasis of non-small cell lung caner (NSCLC) . Several recent studies have shown strong expression of Aquaporin-1 (AQP1) in tumor cells and microvessels of different origins such as lung, breast, brain, ovary and so on. Migration is a key component of tumor spread, including local tumor cell infiltration into surrounding tissue as well as distant metastases. The objectives of the study was to investigate AQP1 distribution and expression in NSCLC, correlating with clinicopathologic variables and microvessel density.Methods: The AQP1 expression and MVD in 50 patients who had undergone curative operation for NSCLC in Fujian Province Cancer Hospital from December 2005 to May 2007 were measured by semiquantitative immunohistochemical technique. We also examined the distribution of the AQP1 in those cases by immunohistochemical staining. In vitro, we analyzed cell migration by transwell assay. A human lung cancer cell line (SPC-A1) was used in this study.Results: AQP1 was located in small vessels in all 50 NSCLC tissues and part of tumor cells, and it mainly located on the membrane of the cells. The expression of AQP1 and MVD were closely related to the histological type and pathologic grade, distant emetastasis. The expression of AQP1 had no relation with the TNM stage, while The MVD in TNM stage I～II was higher than that in stage III～IV (P<0.01).Conclusions: AQP1 is present in NSCLC tissues, and it is localized on the membrane of all microvessel endothelial cells and part of the cancer cells. There is a positively correlated relationship between expression of AQP1 and clinicopathologic variables. AQP1-dependent cell migration may involve in tumor angiogenesis and metastasis. AQP1 expression in tumor cells and tumor vessels may facilitate tumor growth and spread. Although further details on the molecular function remain to be elucidated, our results suggest a potential role of AQP1 as a novel target for the management of NSCLC.