title: Association of PKCζ expression with clinicopathological characteristics of breast cancer.
abstract: The protein kinase C (PKC) family has been functionally linked to cancer. It has been suggested that atypical PKCs contribute to cell proliferation and cancer progression. With respect to breast cancer, PKCζ has been found to play a key role in intracellular transduction of mitogenic and apoptotic signals using mammary cell lines. However, little is known about its function in vivo. Here we examined the correlation between PKCζ protein levels and important clinicopathologic factors in breast cancer using patient samples. To conduct the study, 30 invasive ductal carcinoma cases and their paired normal tissues were used for tissue microarray analysis (TMA) and 16 were used for western blot analysis. In addition, the correlation between PKCζ expression levels and clinicopathologic characteristics was determined in 176 cases with relevant clinical data. Finally, the correlation between PKCζ and epithelial growth factor receptor 2 (HER2) expressions was determined using three breast cancer cell lines by western blot analysis. Both TMA and western blot results showed that PKCζ protein was highly expressed in primary tumors but not in paired normal tissue. The correlation study indicated that high PKCζ levels were associated with premenopausal patients (p = 0.019) and worse prognostic factors, such as advanced clinical stage, more lymph node involvement and larger tumor size. Both disease-free survival and overall survival rates were lower in the high PKCζ group than those in the low PKCζ group. No correlation was observed between PKCζ levels and age, histological grade, or estrogen or progesterone receptor expression status. A positive correlation between PKCζ and HER2 levels was observed in both tumor samples and cell lines. Our observations link PKCζ expression with factors pointing to worse prognosis, higher HER2 levels and a lower survival rate. This suggests that PKCζ protein levels may serve as a prognostic marker of breast cancer.
authors.affiliation: Department of Breast Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Tianjin, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yin
authors.affiliation: Production and R&D Center, Tianjin Binhai Union Gene Technology Co. LTD, Tianjin, China; Gene Bank, Union Stem Cell & Gene Engineering Co. LTD, Tianjin, China.
authors.forename: Zhipei
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Tumor Tissue Banking Facility, Department of Epidemiology and Biostatistics, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China.
authors.forename: Haixin
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Breast Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Tianjin, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China.
authors.forename: Jingyan
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Breast Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Tianjin, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China.
authors.forename: Xinzhong
authors.initials: X
authors.lastname: Chang
authors.affiliation: Department of Breast Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Tianjin, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Breast Surgery, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Tianjin, China; Key Laboratory of Cancer Prevention and Therapy, Tianjin, China; Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: He
authors.affiliation: Laboratory of Cancer Cell Biology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China.
authors.forename: Binghui
authors.initials: B
authors.lastname: Li
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000201:enzymology* / Q000401:mortality / Q000556:secondary; D045744:Cell Line, Tumor; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008875:Middle Aged; D011493:Protein Kinase C / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D000099293:Protein Kinase C-lambda
chemical_list: D007527:Isoenzymes; D011493:Protein Kinase C; D018719:Erb-b2 Receptor Tyrosine Kinases; D000099293:Protein Kinase C-lambda; C508053:ERBB2 protein, human