Expression, Colocalization And Signifcance Of Heat Shock Protein70, Glucose-regulated Protein 94 And Immunoglobulin G In Human Placenta Tumors

HSP is a group of highly conserved proteins synthesized after heat induction. In mammalian cells, this system is divided into Hsps and Grps, which appear to be structurally and functionally related. During the growth and development of normal cells, HSP70 and GRP94 are constitutively expressed at low levels but the expression is dramatically enhanced in stressful condition . Studies suggested that HSP70 and GRP94 continuously expressed at high level in tumor cells without any stimulation, and there is the correlation between expression of HSP70, GRP94 and growth and progression of tumor cells. Human IgG is the most common and most important protein of human immunity. Immunoglobulins were thought to be secreted only by differentiated B lymphocytes. The latest studies confirmed, through immunohistochemistry, RT-PCR and hybridization that many human cancers of epithelial origin also produce IgG. As regard to the expression of HSP70 in hydatidiform mole and the coloclization of HSP70 and IgG in hepatocellular carcinoma have been reported.But the expression and relationship of HSP70, GRP94 and IgG have not been reported.in human placenta tumorsObjective: To investigate the expression, colocalization and signifcance of HSP70,GRP94 and IgG in human placenta tumors. Methods: The expression and colocalization of HSP70, GRP94 and IgG in human placenta tumors and its adjacent tissueswere were studied by immunohistochemistry,Indirect doublelabeling immunofluorescence, reverse transcription polymerase chain reaction (RT-PC )and analyzed by integrated optical density (IOD)with analysis software for immunohistochemisry Results: Both placenta tumors and their adjacent normal tissues could express HSP70, GRP94 and IgG. Of the 39 cases human hydatidiform mole,79.4% (31/39)showed positive HSP70, stained in nuclei and cytoplasma, mainly in nuclei ,while Grp94 and IgG was stained in cytoplasma, and the positive rate were 87.1% (34/39)and 89% (35/39) respectively. Of the 20 cases choriocarcinoma, 75% (15/20) showed positive HSP70, stained in nuclei and cytoplasma, mainly in nuclei, while Grp94 and IgG were stained in cytoplasma, and the positive rate were 80% (16/20) and 90% (18/20) respectively. Imunohistochemistry study showed that the expression of HSP70 and GRP94 were higher in choriocarcinoma than in hydatidiform mole (P = 0.03, P= 0.04, respectively) ,and also showed that Hsp70 expression was higher in cytotrophoblast than in syncytiotrophoblast (P < 0.01),while GRP94 and IgG expression were higher in syncytiotrophoblast cytoplasm than in cytotrophoblast cytoplasm (P< 0.01) in 39 hydatidiform mole. In 20 choriocarcinoma, compared to adjacent normal tissue, the levels of HSP70, GRP94, IgG were significant higher (P < 0.01). So the expression of HSP70 and GRP94 were correlated with tumor cell differentiation in placenta tumors.Moreover, 42/59 placenta tumors expressed Hsp70 also expressed IgG. 48/59 placenta tumors expressed GRP94 also expressed IgG. We also found colocalization of Hsp70, GRP94 and IgG in partial human placenta tumor and choriocarcinoma cell line. Conslusion:We found that HSP70 and GRP94, IgG expressed differently in tumor cell nuclei and plasma, the intensity of HSP70 ,GRP94 and IgG expression was related to the differentiation of placenta tumors.Colocalization of the heat shock protein and human immunoglobulin G may be relationship with the growth and survival of tumour。...