Amplification in tumors and benign tissue of breast cancer patients

Serum and tissue c-erb B2, bcl-2, and mutant p53 oncoprotein levels in nasopharyngeal cancer

To date there are no prognostic factors that can account for the biology and disease behavior in nasopharyngeal cancer. Therefore, identification of new factors that can help in predicting the behavior of the disease and characterizing the subgroup with more aggressive tumors more likely to benefitfrom chemotherapy is important. In this study, c-erb B2, bcl-2, and mutant p53 protein levels were investigated in sera and tumor tissue of patients with nasopharyngeal cancer. Serum c-erb B2 levels were significantly higher in the patients than in the healthy subjects. No meaningful difference was observed between the serum and tissue levels of the mutant p53 protein. Tissue bcl-2 concentrations were considerably high. Our results suggest that serum c-erb B2 levels may aid in identifying a subgroup of patients with a poorer response rate to first-line treatment.

c-erbB-2 gene amplification in nasopharyngeal carcinoma

Amplification of the c-erbB-2 gene has been associated with poor prognosis in different types of cancer. However, there are no data on the c-erbB-2 expression levels in nasopharyngeal cancer. In this study, amplification of the gene has been investigated in the tumor tissue of patients with nasopharyngeal cancer by competitive polymerase chain reaction c-erbB-2 amplification was observed in 43.3% of the patients. The increase in the gene copy number correlated with the T stage. No correlation was found with lymph node involvement, histologic grade, differentiation, presence of metastases, or age and sex. We conclude that c-erbB-2 amplification may contribute to the pathogenesis of nasopharyngeal cancer. Our report is the first study investigating the expression of the c-erbB-2 gene in nasopharyngeal cancer at the DNA level.

Utility of c-erbB-2 expression in tissue and sera of ovarian cancer patients

In this study, expression of the c-erbB-2 gene in tumors and healthy tissue of patients with ovarian cancer was investigated. Serum c-erbB-2 protein levels were also determined. Elevated serum values were observed in 45% of patients. c-erbB-2 protein levels in the tumors were significantly higher than in healthy tissue. Overexpression of the protein was observed in 60% of patients. However, no association was found between the clinical variables and tumor c-erbB-2 expression. This is the first study in the literature investigating the c-erbB-2 oncoprotein levels in the normal and tumor tissue. We conclude that the role of the c-erbB-2 gene in ovarian cancer warrants further studies.

Bcl-2 gene rearrangements and apoptosis rates in patients with non-Hodgkin's lymphoma during chemotherapy

OBJECTIVES

Overexpression of the bcl-2 gene as a result of the t(14,18) translocation leads to neoplastic transformation by suppressing apoptosis. However, apoptotic cell death in response to chemotherapy has not been investigated. This study was planned with the aim to investigate the association between bcl-2 gene rearrangements and apoptotic changes during chemotherapy in patients with non-Hodgkin's lymphoma.

DESIGN AND METHODS

Lymphocytes from 33 patients were collected before and during chemotherapy. Bcl-2 gene rearrangements were investigated by PCR. Apoptotic cell death was analyzed by enzyme immunoassay.

RESULTS

In 24 cases, mbr gene rearrangements were detected. Apoptosis was successfully induced by chemotherapy in 48% of patients. Two characteristic, clearly distinguishable apoptotic response patterns with transient peaks either following the first or the third course were observed. It was found that apoptosis rates measured after the first course exactly reflect the final response. No correlation was found between bcl-2 gene rearrangements and apoptosis.

CONCLUSIONS

Apoptotic cell death rates show transient changes during chemotherapy. Because the midterm response can be misleading, the apoptotic response should be evaluated following the first course of chemotherapy.