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The aims of this study were to assess the role of p53 overexpression in colorectal tumorigenesis and the association with clinicopathological features. The immunohistochemical results were semiquantitatively assessed. Expression of aberrant p53, tumor-suppressor gene product, was studied immunohistochemically using a monoclonal antibody in 11 nonneoplastic polyps, 19 tubular adenomas, 9 villous adenomas, and 48 colorectal carcinomas. Five out of 11 nonneoplastic polyps, 14 out of 19 tubular adenomas and one out of 9 villous adenomas expressed p53 protein. Seven out of 24 colorectal carcinomas without lymph node metastasis and 14 out of 24 colorectal carcinomas with lymph node metastsis expressed p53 protein. The case of more than 75% positivity of p53 in colorectal carcinoma with lymph node metastasis was seven out of 24, but that in lymph node negative group was two out of 24. In the colorectal carcinoma with lymph node metastasis group; metastatic intranodal neoplastic cells were expressed positively for p53 in 10 out of 14 cases and zero out of 10 cases in group of positive and negative expression of primary lesions, respectively. p53 protein expression was not significantly correlated with variable clinicopathologic features such as age, sex, tumor location, tumor size, differentiation and Dukes' stage. It is suggested that p53 protein overexpression could be a early event in pathogenesis of colon cancer but is not involved in progression of villous adenoma to adenocarcinoma. p53 overexpression seems to be involved in metastatic ability of colorectal carcinomas.
Adenoma ; Neoplasm Metastasis ; Cell Transformation, Neoplastic

6.p53 Expression in the Head and Neck Tumor.

Chae Hong SUH ; Mi Sook LEE ; Sin Eui YOON

Korean Journal of Pathology 1996;30(7):576-586

Mutations in the p53 gene seem to be the most common genetic changes in human malignancies. Mutation or altered p53 expression is a common occurrence in many solid neoplasms, including head and neck carcinomas. Recent studies have also shown p53 alterations in several premalignant conditions of the colon, esophagus, lung, and brain. Preliminary data have suggested that p53 mutations may be involved in tumor progression. This study was performed to determine the incidence of p53 mutations in histologically 27 squamous cell carcinomas, 19 basal cell carcinomas, 18 Schneiderian papillomas, 3 Schneiderian papillomas with malignant transformation, and 15 pleomorphic adenomas of the head and neck region. The degree of p53 gene overexpression was also evaluated according to differentiation, histologic type of tumor, and tumor progression in the head and neck carcinomas. The results were as follows; 1) Eighteen of 27 squamous cell carcinomas, and 4 of 27 dysplasias adjacent to the squamous cell carcinoma of the head and neck expressed p53 protein, but none of the normal control specimens expressed detectable p53 protein. There was no relationship between differentiation of squamous cell carcinoma and p53 protein expression. 2) Twelve of 19 basal cell carcinomas expressed p53 protein; the adenoid type especially overexpressed p53 protein. 3) Nine of 15 pleomorphic adenomas expressed p53 protein especially in the epithelial components. 4) Thirteen of 18 Schneiderian papillomas and all Schneiderian papillomas with malignant transformation expressed p53 protein. The above results indicate that the p53 protein expression is a useful tool for the prediction of tumor progression in the head and neck tumor, but there was no relationship between the differentiation of the tumor and p53 protein expression.
Humans ; Incidence ; Adenoma ; Genes, p53

7.Clinical Application of Polymerase Chain Reaction for the Diagnosis of Extrapulmonary Tuberculosis.

Sang Sin PARK ; Mi Ae LEE ; Ki Sook HONG

Korean Journal of Clinical Pathology 1997;17(1):79-88

BACKGROUND: There are many reports showing the efficacy of polymerase chain reaction(PCR) for the diagnosis of Mycobacterium tuberculosis in sputum. but only few reports in extrapulmonary specimens. Because of the difficulty in establishing a diagnosis of tuberculosis in the extrapulmonary specimens there have been considerable interest in the development of a rapid sensitive diagnostic test that might be useful. Therefore we used PCR for detection of M. tuberculosis DNA in extrapulmonary specimens and compared the results of conventional acid-fast stain, culture methods and PCR assay. METHODS: Total of 63 clinical samples(10 cerebrospinal fluids, 12 pleural fluids, 1 pericardial fluid, 3 bone marrow aspirates, 1 ascitic fluid, 25 fine needle aspirates of lymph nodes, 7 urine, 1 stool and 3 tissue biopsies) in Ewha Womans University Tongdaemun hospital were analysed by the PCR. We performed the PCR using a species-specific M. tuberculosis DNA fragment(mtp 40 gene) as primers that was cloned and sequenced at recent and a 396-bp fragment was specifically amplified. We analyzed sensitivity and specificity of AFB culture and PCR for the diagnosis of extrapulomonary tuberculosis. RESULTS: The positivity of AFB smear, culture and PCR were 2(10%), 4(20%), 13(65%) out of total 20 cases diagnosed as clinically active extrapulmonary tuberculosis. respectively. All of 2 smear-positive samples and 2 of 4 culture-positive and smear-negative samples were PCR-positive. And 9 of 14 smear and culture negative specimens also gave detectable DNA products in PCR The specificity of PCR(95.4%) is compared with those of smear and culture(100.0%). CONCLUSIONS: This results suggest that the PCR assay is a sensitive and rapid diagnostic alternative to classical procedures for the diagnosis of extrapulmonary tuberculosis.
Ascitic Fluid ; Bone Marrow ; Cerebrospinal Fluid ; Clone Cells ; Diagnosis* ; Diagnostic Tests, Routine ; DNA ; Female ; Humans ; Lymph Nodes ; Mycobacterium tuberculosis ; Needles ; Polymerase Chain Reaction* ; Sensitivity and Specificity ; Sputum ; Tuberculosis*