Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aquaporins represent a family of transmembrane water channel proteins that play a major role in trans-cellular and transepithelial water movement. Most tumors have been shown to exhibit high vascular permeability and interstitial fluid pressure, but the transport pathways for water within tumors remain unknown. Here, we tested 10 non-small cell lung cancer cell lines of various origins by reverse transcriptase-polymerase chain reaction and Western blot analysis and identified clear expression of aquaporin 1 (AQP1) in seven cell lines. We next examined the distribution of the AQP1 protein in several types of primary lung tumors (16 squamous cell carcinomas, 21 adenocarcinomas, and 7 bronchoalveolar carcinomas) by immunohistochemical staining. AQP1 was overexpressed in 62% (13 of 21) and 75% (6 of 8) of adenocarcinoma and bronchoalveolar carcinoma, respectively, whereas all cases of squamous cell carcinoma and normal lung tissue were negative. Forced expression of full-length AQP1 cDNA in NIH-3T3 cells induced many phenotypic changes characteristic of transformation, including cell proliferation-enhancing activity by the MTT assay and anchorage-independent growth in soft agar. Although further details on the molecular function of AQP1 related to tumorigenesis remain to be elucidated, our results suggest a potential role of AQP1 as a novel therapeutic target for the management of lung cancer.
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PMID:Aquaporin 1 is overexpressed in lung cancer and stimulates NIH-3T3 cell proliferation and anchorage-independent growth. 2290 56

Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring cancer in sheep, with clinical, radiologic, and histopathologic features similar to that of human pneumonic-type bronchioloalveolar carcinoma. JSRV (Jaagsiekte Sheep RetroVirus) is the etiologic agent of this contagious lung cancer in sheep. Cells involved in the tumor derive from alveolar type II cells and Clara cells, epithelial cells of the distal respiratory tract. These cells are the major site for viral expression in JSRV-infected animals. Recent studies clearly described the oncogenic properties of the JSRV envelope protein both in vitro and in vivo. Interestingly, the cellular pathways involved in the transformation process seem to be dependent of the origin and type of the cell used. In order to investigate the specific interactions between JSRV and alveolar type II cells, we developed an in vitro experimental model in which lung epithelial cells were isolated from OPA and control lungs. Cells in culture expressed alveolar type II cell specific markers such as surfactant protein (SP)-A, SP-C, and a high alkaline phosphatase activity. Alveolar Type II cells derived from tumoral lungs showed a proliferative advantage and expressed the JSRV virus. The reverse transcriptase activity decreased over passages in monolayer culture conditions, but was efficiently maintained in three-dimensional culture conditions. We thus report on the first in vitro system whereby alveolar type II cells from OPA were efficiently maintained in culture and stably expressed JSRV. This novel experimental model will set up the stage for elucidating lung epithelial transformation in the JSRV-induced tumor.
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PMID:Alveolar type II cells isolated from pulmonary adenocarcinoma: a model for JSRV expression in vitro. 1715 59