Expression of Proliferating Cell Nuclear Antigen and p53 Protein in Ovarian Epithelial Tumors

p53 gene mutation is commonly accepted to be associated with loss of negative cell cycle control and progression of tumors. The proliferative activity of tumor cells is considered to be a valuable indicator of tumor aggressiveness. This study is intended to compare p53 protein expression with cell proliferation rates in the ovarian epithelial tumors according to the various clinicopathological parameters. Immunohistochemistry using monoclonal p53 antibody (DO-1) and PCNA antibody (PC10) was applied to 56 cases of ovarian epithelial tumors including 17 cases of borderline tumor. The results were as follows. Both immunohistochemical staining of PCNA and p53 protein showed positive reactions confined to the nuclei of tumor cells. There were significant differences of p53 protein expression rates between borderline malignancies (11.8%) and cystadenocarcinomas (56.4%) of ovary. The expression rate of p53 protein was not significantly different according to the differentiation and the stage, but the cases of strong positive reaction to p53 protein were more frequently noted in the poorly differentiated and advanced staged tumors. The PCNA indices of p53 strong positive cases were higher than those of p53 weak positive cases. In summary, p53 protein and PCNA expression may be used as an adjuvant in differentiating borderline lesions from carcinomas of ovary and predicting their biological behaviors.

The Expression of ras Oncogene in Benign and Malignant Lesions of Breast

To evaluate correlation between the amount of oncogene products in tumor cell extracts and malignant potentiality in breast tumor, immunohistochemical staining for the ras Oncogene products was performed in the sections of benign and malignant lesions of the breast. The results obtained were as follows: 1) The positive reaction to ras Oncogene products was usually observed in the cytoplasm and cell membrane. 2) The ratio of positive reaction was 30.4% in epithelial hyperplasia of fibrocystic disease, 26.5% in fibroadenoma. 49.5% in intraductal carcinoma 71.6% in infiltrating ductal carcinoma, 85.2% in metastatic infiltrating ductal carcinoma, and 89.7% in relatively preserved neighboring lobules of infiltrating ductal carcinoma. In conclusion, the ras oncogene products are found by a significantly higher ratio in the more aggressive lesions, and the infiltrating ductal carcinoma might represent its potential of malignant transformation. 3) The expression of ras oncogene was heterogeneous in primary as well as metastatic mammary carcinomas.

A Study on the Cell Kinetics of the Dysplastic Epithelium in the Stomach

This study was designed to evaluate the biological behavior of the dysplastic lesion of the stomach by applying immunohistochemical method for bromodeoxyuridine (BrdUrd). The results obtained were as follows. 1) In most hyperplastic and dysplastic lesions, the proliferative cell zones, loci of BrdUrd-labelled cells, were found in the upper later of the mucosa, whereas they were confined to the neck zone in the normal gastric mucosa. 2) The labelling indices (LIs), percentages of BrdUrd-labelled cells, were 11.0% to 13.6% in the normal gastric mucosa, and were 14.3% to 17.9%, 16.4% to 19.2% and 17.4% to 20.7% in the simple hyperplasia, in the atypical hyperplasia and in the dysplasia, respectively. These findings suggested that proliferative potential in hyperplasia and dysplasia were greater than that in normal gastric mucosa, the higher the grade of dysplasia being, the greater the proliferative potentials.