The Expression And Significance Of Bc1-2 And Bag-1 Protein In Renal Cell Carcinoma

Apoptosis is a distinct mode of cell death that has been shown to differ from necrosis by morphological and biochemical features that include cytoplasmic and nuclear condensation, subsequent formation of membrane-bound apoptotic bodies and oligonucleosomal DNA degradation. Unlike necrosis, apoptosis is characteristically not associated with an inflammatory cell infiltrate. Apoptosis results in physiological cell deletion during development in a variety of tissues and organisms, it also occurrs spontaneously in malignant tumors and is increased in tumors responding to irradiation, cytotoxic chemotherapy, heating, hormone ablation and other anti-cancer therapies. Apoptosis increasingly has been attracting oncologists' attention for the discovery that apoptosis can be regulated by certain proto-oncongenes and tumor suppressor gene P53,Among these apoptosis regulator proto-oncogenes, Bcl-2 inhibits apoptosis rather than stimulating cell division.In investigating the genes' structures of bcl-2-associated proteins , Takayama S etc(1995) identified an associated 274 amino acids protein parter, bag-1. Bag-1 protein encoded bybag-1 gene which called bcl-2-associated athanogene 1, has no amino acid homology with bcl-2 protein. So, bag-1 is a novel bcl-2-binding protein. The protein functions are inhibiting apoptosis with binding to bcl-2 and restraining cell death independently.Besides apoptosis regulator activity, bcl-2 and bag-1 are related to a variety of malignant tumors such as breast cancer, lung cancer etc, by showing different effects on their development, progression, therapy and outcom.Although apoptosis, bcl-2 and bag-1 have been observed in a variety of normal tissues and malignant tumors, there were few reports about them on kidney and renal cell carcinoma(RCC). It has been reported recently that parietal layer cells of Bowman's capsule and the epithelial cells of tubules in adult kidney and cells of RCC exhibited immunohistochemically detectable levels of bcl-2 protein, and that bcl-2 protein was inversely correlated with apoptosis in the neogenic zone of the developing kidney.In our study, to investigate the implications of apoptosis, bcl-2 and bag-1 expression in RCCs'development and progression, Using immunohistochemical techniques, we observed the expressions of bcl-2 and bag-1 in RCCs and nomal renal tissues, We observed apoptosis in the same samples of RCCs, analysis of our observations suggested following conclusions (1)RCC has the same histologic original with the epithelial cells of renal tubules. 〦levation of bcl-2 and bag-1 expression is an important component in the development and progression of RCC, and Deregulation of bag-1 protein expression is also related to RCC metastasis, which is an5important predictive factor of malignant tumors. (3) In RCC, apoptosis is mediated by more than one genes, compare to bcl-2, the apoptosis regulator activity of bag-1 is more dominant.?Decrease of apoptosis plays a role in the over-growth of RCC and affects the clinic pathology, therapy and outcome of RCC.