| Breast cancer is one of the common malignant tumors for female patient, it badly threaten the health of female. The most common type of breast cancer o-riginates from the duct - lobule unit of mammary gland, there is a series of change before the appearance of breast cancer, for example, hyperplasia of mammary gland progresses to atypical hyperplasia, carcinoma in situ progresses to infiltrating carcinoma. During the occurrence and progression of breast cancer, some molecular mechanisms regulating apoptosis were changed. With the development of molecular biology, some people probe into the occurrence and progression of breast cancer gradually by study apoptosis.The Hsp70 ( heat shock protein 70) family of proteins are ubiquitous chaperon , which have a highly conserved attribute. The thermoprotective effect of the inducible Hsp70 protein is well established, furthermore it has been demonstrated to be a potent inhibitor of apoptosis induced by a wide range of stimuli.The Fas protein ( CD95 ) is a member of the receptor of tumor necrosis factor super - family proteins, and it belongs to a signal transduction system. Acti-vation of Fas — mediated apoptosis is induced by binding of its physiological lig-and, FasL (Fas ligand) or by anti - Fas antibodies.We evaluate the altered expression of Hsp70,Fas and FasL in breast caner and the surrounding non - cancerous tissue by immunohistochemistry and Western blot, and then analyze the role of Hsp70,Fas and FasL in occurrence and progression of breast cancer binding clinical and pathological data ( such as: tumor diameter, LN metastasis, PCNA, ER and PR etc).Materials and MethodsThere are 15 operative specimen of breast carcinoma with self — contained clinical and pathological data to research in our experiment. Every specimen was shared to 2 parts, one was fixed by marinating in 10% formalin, then it would be stained by HE and S - P immunohistochemistry (IHC ) , results from IHC were evaluated by Meta Morph/DP10/BX41 micro - image analyzing system; the other one was kept in liquid nitrogen, then it would be made into histo - ho-mogenate, the expression of Hsp70,Fas and FasL protein in breast carcinoma would be evaluated by Western blot, results from Western blot were analyzed by Glyko BandScan version 4. 50 image analyzing system. All data was tested by SPSS11.5 for Windows, when P less than 0.05, the difference is significant.ResultsThe rate of expression of Hsp70NFas and FasL in breast carcinoma tissue and the surrounding non - cancerous tissue is respectively 93. 33% , 60% ,x -4.658, P =0.031; 53.33%, 93.33%,x2 =6.136, P =0.013; 93.33%, 53. 33% ,x =6.136, P =0.013. The difference between the control group and the cancer group is significant. The rate of expression of Hsp70 and FasL is more than that of Fas in breast carcinoma tissue, the difference is statistically significant. Moreover, Hsp70 and FasL in breast carcinoma tissue is super - expression , Fas is hypo - expression. On the contrary, the rate of expression of Hsp70 and FasL is less than that of Fas in the surrounding non - cancerous tissue; Fas in the surrounding non - cancerous tissue is super - expression, Hsp70 and FasL is hypo - expression. When we tested the result from Western blot, we found that Hsp70 and FasL were observed in all breast carcinoma tissue (n = 15) , the level of expression of them is higher than that of them in the surrounding non -cancerous tissue, P <0.01; Fas was observed in all the surrounding non - cancerous tissue (n = 15) , and the level of expression of Fas is higher than that of Fas in breast carcinoma tissue, P<0.01.DiscussionBreast cancer cells in bodies can survive and develop continually, which is a complex pathological course with many factors and pathways. Cancer cells up- regulate the level of expression of many anti - apoptotic factors, and down -regulate the level of expression of many factors inducing apoptosis at the same time. So the rate of apoptosis of cancer cells is less than that of normal cells, and then cancer cells can propagate persistently.Hsp70 mediated protection from apoptosis may be based on interference with several proapoptotic signal transduction pathways. Hsp70 can inhibit the cascade reaction of apoptotic signal transduction pathways by blocking the activation of caspase - 3 in cells. After Hsp70 shock response is activated, the up- regulate of Hsp70 protein synthesis which inhibits the activation of Fas signal system to result in protecting from Fas - mediated apoptosis, which might serve as an explanation for reinforced cancer cell anti - apoptosis in the presence of Hsp70.Fas/FasL signal transduction pathway is not only one important pathway of apoptosis, but also one important pathway of cytotoxic T lymphocyte(CTL)killing target cells. CTL kills target cells, which based on Fas/FasL system. CTL takes mostly responsibility for immune surveillance and clears tumor cells. Tumor cells resist Fas - mediated apoptosis by expressing disabled Fas or decreasing Fas protein synthesis themselves, to escape to immune surveillance and attack; tumor cells can also counterattack the immune system of bodies by increasing FasL protein synthesis and inducing apoptosis of T cells expressing Fas protein, then they would survive and develop continually.Fas and FasL can express in the same tumor tissue section, but they may not induce apoptosis of tumor cells, the reason for that may be that tumor cells have many mechanisms resisting apoptosis mediated by Fas. For example; the expression of Fas protein down - regulate, Fas protein is disabled, there is something wrong on the apoptosis signal transduction pathways, there are some anti - apoptosis factors in tumor cells. All these factors protect tumor cells from...
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