Biomedical subjects

B Youngson

Publications and source records attributed to B Youngson.

3 recordsLinked to original sources

PubMed1999

Examination of POU homeobox gene expression in human breast cancer cells.

Abnormal expression of homeobox genes may lead to the development of leukemias, lymphomas, and solid tumors. Expression of homeobox genes in mammary glands, however, has not been studied actively until recently. We have examined the expression of POU homeobox genes in human breast cancer cell lines and human breast tissue samples. Using a pair of degenerate primers for reverse transcription-polymerase chain reaction (RT-PCR) followed by DNA sequencing, we found that the human breast cancer cell line, MCF7, expresses at least 4 POU gene products: OCT1, OCT2, OCT3 and OCT11 (Skn-1a/i, Epoc-1). The expression of OCT1 and OCT2 in other human breast epithelial cell lines was further determined by Western blot analyses and electrophoretic mobility shift assay. We were unable to detect OCT11 in human breast cancer cell lines using the anti rat Skn-1a/i antibody, although the expression of this gene in both human breast cancer cell lines and human primary breast tumors was detected by RT-PCR. OCT3 is an embryonic transcription factor. We found that this gene is also expressed in human breast cancer cell lines and all human primary breast carcinomas examined, but not in normal human breast tissue. Taken together, we have shown that several POU genes are expressed in human breast epithelial cells. As OCT3 expression was detected only in the breast cancerous cells, this embryonic transcription factor could play an important role in mammary gland carcinogenesis.

Amino Acid Sequence↗

PubMed1995

Mutations of the p53 gene in male breast cancer.

BACKGROUND: Cancer of the male breast (MBC) is rare, accounting for less than 1% of cancer in males and representing less than 1% of all breast cancers. Reports of abnormalities in the expression of the tumor suppressor gene p53 in MBC have been few. METHODS: To assess the expression and mutations of the p53 gene, 35 patients with 36 MBC (one patient with bilateral breast carcinoma) were examined using immunohistochemical methods, polymerase chain reaction (PCR)-single strand conformation polymorphism and DNA sequencing. RESULTS: Thirty-one of the 36 carcinomas were studied by immunohistochemistry and by the PCR-based approach. Five patients were studied by immunohistochemistry only. Twelve patients (41.4%) of the 29 studied by molecular analysis presented an altered pattern in the single strand conformation polymorphism gel and point mutations were confirmed in all by direct DNA sequencing. Thirty-six tumors were studied by immunohistochemistry and 2 (5.5%) patients showed overexpression of the p53 protein. There were no statistically significant differences in p53 status with respect to: age, stage, estrogen receptors, progesterone receptors, tumor type. Patients with normal p53 showed a predisposition, although not statistically significant, for a longer disease free survival (5.6 years versus 4.2 years) and overall survival (5.9 years versus 4.8 years) than did patients with genetically altered p53. CONCLUSIONS: The incidence of male patients detected with p53 mutations (41.4%) in this series is concordant with the incidence of p53 mutations in female breast cancer, supporting the idea that cancer of the male breast is similar to the female counterpart.

Age Factors↗

PubMed1989

Calcification in bronchopulmonary sequestration.

We report an unusual complication in a patient with intralobar bronchopulmonary sequestration. Chest tomography, computed tomography, and specimen radiography showed a mass containing numerous round calcifications in the posterior basal segment of the left lower lobe. Pathologic examination disclosed an Exophiala fungus infection and broncholiths within bronchiectatic cavities in the sequestered segment.

Adult↗