IN SITU IMAGING OF BREAST CANCER CELLS USING GREEN SEMICONDUCTOR QUANTUM DOTS

The breast cancer is the most common cause of cancer death in women. To establish an early stage in situ imaging of breast cancer cells, green quantum dots （QDs） are used as a fluorescent signal generator. The QDs based imaging of breast cancer cells involves anti-HER2/neu antibody for labeling the over expressed HER2 on the surface of breast cancer cells. The complete assay involves breast cancer cells, biotin labeled antibody and streptavidin conjugated QDs. The breast cancer cells are grown in culture plates and exposed to the biotin labeled antibodies, and then exposed to streptavidin labeled QDs to utilize the strong and stable biotin-streptavidin interaction. Fluorescent images of the complete assay for breast cancer cells are evaluated on a microscope with a UV light source. Results show that the breast cancer cells in the complete assay are used as fluorescent cells with brighter signals compared with those labeled by the organic dye using similar parameters and the same number of cells.

Characterization of hepatic progenitors from human fetal liver using CD34 as a hepatic progenitor marker

AIM: To enrich putative hepatic progenitors from the developing human fetal liver using CD34 as a marker. METHODS: Aborted fetuses of 13-20 wk were used for the isolation of liver cells. The cells were labeled with anti CD34; a marker used for isolating progenitor population and the cells were sorted using magnetic cell sorting. The positive fractions of cells were assessed for specific hepatic markers. Further, these cells were cultured in vitro for long term investigation. RESULTS: Flow cytometric and immunocytochemical analysis for alphafetoprotein (AFP) showed that the majority of the enriched CD34 positive cells were positive for AFP. Furthermore, these enriched cells proliferated in the long term and maintained hepatic characteristics in in vitro culture. CONCLUSION: The study shows that aborted human fetal liver is a potential source for isolation of hepatic progenitors for clinical applications. The study also demonstrates that CD34 can be a good marker for the enrichment of progenitor populations.

Preparation of monoclonal antibody to P53 and its clinical application

Objective：The aim of this study was to prepare monoclonal antibody against P53, a kind of tumor suppressor protein,and use the antibody initial y in clinical immunoassay. Methods：Monoclonal antibody was prepared and identified via the classic protocol of monoclonal antibody preparation. Identified monoclonal antibodies were purified by af inity chro-matography. Antibody titer was determined by enzyme linked immunosorbent assay （ELISA）. The specific binding activity of antibody was detected by Western blotting and immunohistochemistry. Results：Three strains of monoclonal antibodies named 1P15, 2P37 and 3P40 were obtained and purified by af inity chromatography. The purity of antibodies was higher than 90%. The titers of antibodies were more than 1：6000. Western blot and immunohistochemistry assay showed that the specific antibody can combine with endogenous P53 protein in the tumor celllines and determine the expression of P53 in tumor tis-sue. Conclusion：Three strains of monoclonal antibodies with high af inity to P53 were successful y established, which can be used for detecting the expression of P53 in tumor cells or tissue.

The significance of cyclin B1 expression in colorectal cancers

Objective: To study the relationship between the expression of human cyclin B1 in colorectal carcinomas and the pathological characters. Methods: The Expression of cyclin B1 in 66 cases of colorectal carcinomas were detected by flow cytometry and immunohistochemistry. Then the relationship between the expression of cyclin B1 in colorectal carcinomas and pathological characters was analyzed with statistics. Results: The expression of cyclin B1 in colorectal carcinomas had associa- tivity with the cancer cell differentiation (P<0.05); However, the expression of cyclin B1 in colorectal carcinomas had no obvious associativity with cancer cell infiltrate depth and lymph nodes metastasis (P>0.05). Conclusion: In the colorectal cancers with high expression of cyclin B1, the cancer cells would present high differentiation; with low expression of cyclin B1 the cancer cells would present low differentiation. Along with the expression of cyclin B1 from high to low, the cancer cells differentiation has the tendency from high to low too.

Immunohistochemical characterization of β-catenin in gynecologic tumor and its diagnostic value

β-catenin is a very unusual protein with multiple functions depending on its cellular localization. The β-catenin gene (CTNNB1) encodes for β-catenin and apart from its well-defined role in cellular adhesion,it is also a component of the Wnt signalling pathway. The Wnt/β-catenin pathway is involved in various normal cellular activities,including determination,proliferation,migration and differentiation in embryonic development and adult homeostasis. Deregulation or constitutive activation of the Wnt/β-catenin pathway may lead to cancer formation. Immunohistochemical expression of β-catenin in gynecologic tumor have been reported recently. In normal epithelia,immunoreactivity was strongly observed at the membrane,partially at cytoplasm,nuclear staining of β-catenin was rarely seen in normal cases; In ovarian carcinomas,β-catenin nuclear expression was found more commonly in endometrioid carcinomas,nuclear β-catenin staining seemed to be of prognostic importance; In endometrium carcinomas,β-catenin nuclear expression were more common in pure endometrioid tumors than in unendometrioid tumors,associated with favorable prognosis,the staining pattern was independent of the menopausal status; In synchronous primary cancers of the endometrium and ovary,activating mutations in β-catenin seemed to distinguish synchronous primary tumors from metastatic tumors.