DETECTION OF CELL-PROLIFERATION IN TISSUE-SECTIONS

1. Cell proliferation is of interest since abnormal cell proliferation appears to be a precursor of tumorigenesis and also because the quant itative description of cell proliferation in tumors can be used to pre dict the biological behavior of a particular neoplasia. 2. Them am sev eral reliable methods of studying cell proliferation in tissues. One o f the most important is the detection of the Ki67 defined antigen in f rozen sections. The number of cells expressing Ki67 correlates with hi stological grades of tumors and can also be predictive of clinical out come. The Ki67 can be localized in tissue sections using monoclonal an tibodies in association with the immunoperoxidase technique. 3. Prolif erating cell nuclear antigen (PCNA) is a component of DNA polymerase-d elta and is another important cell proliferation marker manifesting a striking increase in concentration during the S phase of the cell cycl e. 19A2 and PC10 are two different monoclonal antibodies which can be employed to detect PCNA in paraffin-embedded tissues. 4. Molecular bio logy has also been making a great contribution to the study of cell pr oliferation. The most recent innovation in tissue identification of pr oliferating cells is the use of in situ hybridization for the localiza tion of histone H3 and/or H4 mRNA. H3 mRNA-positive cells appear to be present in basal cells of the skin and in crypt cells of the intestin e which are sites with high proliferation rate.