Studies on Focal Adhesion Kinase in human breast cancer cell MDA-MB-231

AIM: 1) To study the participation of Focal Adhesion Kinase (FAK) in regulation of Breast Cancer cell migration in relation with MMP-9 and other signaling proteins. 2) To study the effect of some natural products on FAK. METHODS: Cell culture, Western Blot, Immunoprecipitation, Immunocytochemistry, Zymography, SiRNA transfection, RT-PCR, Real-Time PCR. RESULTS: For our study on FAK, we selected invasive Breast Cancer cell line MDA-MB-231 and treated the cells with Fibronectin (FN). Treatment of FN was found to increase FAK expression, phosphorylation (Tyr 397). FAK was found to be involved in re- gulation of breast cancer cell migration and MMP-9 expression, activity. Fi-bronectin increases association of FAK with integrin α5β1, Paxillin, Actin, ERK, PI3K and localization at Focal Adhesion sites. FAK was found to be involved in modulation of ERK and PI3K phosphorylation. Moreover, FAK signal was found to be transduced through ERK and PI3K, which modulate MMP-9 and thereby cell migration. CONCLUSION: FAK expression, phosphorylation and processing are induced in response to Cell-ECM interactions. Integrin α5β1 is involved in FN induced FAK phosphorylation. FAK is a potent regulator of MMP-9 expression and activity. FAK is involved in regulation of ERK and PI3K phosphorylation. ERK and PI3K are involved in FAK regulated MMP-9 expression & activity. FAK regulates MMP-9 expression and activity and thereby migration of human breast cancer cell. By the regulation of FAK, cell attachment and migration may be regulated by Curcumin, ATRA or EGCG treatment. It may be concluded that invasive potential of breast cancer cells may be modulated by regulation of FAK.

Studies on Focal Adhesion Kinase in Human Breast Cancer Tissue

Aim: To study Expression and Phosphorylation status of Focal Adhesion Kinase (FAK) in Human Breast Cancer tissue. To study the relation of FAK with standard clinicopathological parameters of Human Breast Cancer. Methods: Tissue collection, Protein extraction, RNA isolation, Western Blot, Immunohistochemistry, RT-PCR, ELISA, Statistical analysis. Results: All the four techniques showed upregulated expression, phosphorylation (Tyr-397) and processing of FAK in human breast cancer tissue compared to the adjacent non-tumor tissue of the same patient. Upregulation of FAK was found to be increased parallely with the advancement of cancer. Localisation of FAK was found to be membrano-cytoplasmic. FAK is upregulated both in protein and mRNA level. Expression and phosphorylation of FAK is increased specifically in the tumor regions compared to the surrounding non-tumor region. Upregulation of FAK was frequently found in ER-positive and PR-positive but Her2/neunegative breast cancer cases. Conclusion: FAK has crucial role in development and progression of human breast cancer. FAK may be considered as an indicator of human breast cancer progression. FAK processing may be considered as an indicator of invasive potential of breast cancer. FAK may be considered as a clinical indicator of human breast cancer development and progression.