The activities of Ca+2-PL dependent protein Kinase (PKC) and independent protein kinase(RKM) were measured in human stomach and breast tumors and in the respective counterparts of normal tissue. Expression of c-fos and c-myc of the tissues were also measured. RNAs of c-fos and c-myc were unexpectedly high in the tissue from normal stomach and breast as well as in all cancer tissue. On the other hand, cytosolic and particulate PKC activities were higher in the tumors as compared to those of normal controls. Notably, some cases exhibited. altered activities of PKC i.e. increased RKM activities as high as RKC, which might be related to the autocrine control of growth in the tumor mass.
Adenocarcinoma/enzymology* ; Breast Neoplasms/enzymology* ; Carcinoma, Intraductal, Noninfiltrating/enzymology* ; Human ; Protein Kinase C/metabolism* ; Stomach Neoplasms/enzymology*

OBJECTIVETo investigate the relationship of telomerase genes and the malignant transformation of atypical mammary ductal hyperplasia.

METHODSTelomerase genes hTR and hTRT in 50 cases of mammary hyperplasia (the cases included 6 benign hyperplasia, 9 mild atypical hyperplasia, 12 medium atypical hyperplasia, 23 severe atypical hyperplasia) and 26 cases of breast carcinoma were detected by in situ hybridization.

RESULTSThe expression of hTR and hTRT mRNA were weak or negative in benign hyperplasia (1/6, 0), weaker in mild-moderate atypical hyperplasia (2/9, 1/9, 4/12, and 3/12), strong in severe atypical hyperplasia (14/23, 60.9% and 12/23, 52.1%), while very strong expression (23/26, 88.5% and 21/25, 80.8%) in carcinoma of the breast. The difference between mild-moderate atypical hyperplasia, invasive ductal carcinoma and severe atypical hyperplasia was significant (P < 0.05) and the difference between severe atypital hyperplasia and intraductal carcinoma was not significant (P > 0.05).

CONCLUSIONSTelmerase genes (hTR, hTRT) expression is closely related to the malignant transformation of atypical hyperplasia. The reactivated telomerase may play a crucial role in the development of breast cancer.

Breast Neoplasms ; enzymology ; pathology ; Carcinoma, Intraductal, Noninfiltrating ; enzymology ; pathology ; DNA-Binding Proteins ; Female ; Gene Expression ; Humans ; RNA, Messenger ; Telomerase ; genetics