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Biomedical subjects

G C Chamness

Publications and source records attributed to G C Chamness.

80 records · Page 5Linked to original sources
PubMed1972

Mammary carcinoma: a specific biochemical defect in autonomous tumors.

Rat mammary carcinoma (R3230AC) which does not regress after ovariectomy has a markedly reduced amount of cytoplasmic estradiol binding protein. Cytoplasm from the tumor fails to interact with estradiol sufficiently to permit estradiol binding to tumor chromatin. This defect can be corrected in vitro by substituting cytoplasm, containing the binding protein, from rat uterus, thus permitting estradiol binding to tumor chromatin. The results indicate that the hormonal autonomy of this carcinoma is due to a lack of estradiol binding protein and not to the inability of estradiol to interact with the cell genome.

Animals↗
PubMedDate not supplied

Expression of HER-2/neu oncoprotein in human breast cancer: a comparison of immunohistochemical and western blot techniques.

Three hundred and one primary breast cancers from patients with tumor infiltrated lymph nodes were analyzed for the presence of HER-2/neu oncoprotein by two procedures: Western blot (WB) and immunohistochemistry (IHC). Overexpression of this protein was found by WB in 16.6% of the tumors, and by IHC in 16.3%. Concordance between the two methods was found in 95% of tumors (286/301). In 7 cases we found HER-2/neu by IHC but not by WB, while the opposite was found in the remaining 8 patients. This discrepancy was found mainly in samples with HER-2/neu values just above the cut points and were therefore close to the sensitivity limits of the procedures used here. This study helps to define the parameters that should be considered to evaluate the immunostaining for HER-2/neu as positive (i.e., membrane staining, IHC score of 2 or more). The results obtained by both techniques were correlated with several currently used prognostic factors. Higher HER-2/neu protein expression was found in tumors lacking estrogen or progesterone receptors, in tumors with high S-phase fraction and in patients with more than 3 positive lymph nodes. In contrast, no relationship was found between overexpression of this protein and tumor size, ploidy, or age of the patient. Patients with elevated HER-2/neu expression showed a significantly worse overall survival by both methods, IHC (p = 0.05) and WB (p = 0.001). In conclusion, there is very high agreement between IHC and WB when measuring expression of HER-2/neu and both techniques showed prognostic significance.

Biomarkers, Tumor↗