Inhibitory role of focal adhesion kinase on anoikis in the lung cancer cell A549.
Resistance to anoikis is a characteristic of malignant cells with increased tumorigenesis and metastasis. Altered FAK activity has been strongly implicated in the development, growth, progression, and metastasis of human cancers, but the mechanism of FAK in regulating anoikis is unknown. In this study, the resistance anoikis role of FAK and its downstream mediators was evaluated in the human lung cancer cell line A549. It has been shown that down regulation of FAK stimulates the apoptosis of cells and the down-regulation of p-ERK, p-PI3K, p-Src, and p-p38. Furthermore, in detached A549 cells, increased FAK phosphorylations (Tyr397, Tyr861, Tyr925) were detected in a time-dependent manner, and the specific inhibitors of MEK1, PI3K, and Src (PD98059, LY294002, and PP2) partly abolished the resistance to the anoikis characteristic of cancer cells. Altogether, our data suggested that Src is involved in the progress of detachment-induced FAK activation in lung tumor cells. PI3K/AKT, MAPK-ERK, and perhaps MAPK-p38 but not MAPK-JNK, appear to be the key downstream effectors of FAK in mediating cell survival. The increased FAK activity upon cell detachment may contribute to the metastasis potential of malignant tumors.
Liu
Gaiyun
G
Laboratory of Medical Genetics, Harbin Medical University, Harbin 150081, PR China.
Meng
Xiangning
X
Jin
Yan
Y
Bai
Jing
J
Zhao
Yunzhen
Y
Cui
Xiaobo
X
Chen
Feng
F
Fu
Songbin
S
D023102:Anoikis; D045744:Cell Line, Tumor; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology* / Q000473:pathology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism; D034622:RNA Interference; D015398:Signal Transduction
D019869:Phosphatidylinositol 3-Kinases; D051416:Focal Adhesion Protein-Tyrosine Kinases; D016392:Proto-Oncogene Proteins pp60(c-src); D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D020928:Mitogen-Activated Protein Kinases