Abstract LB-137: Tissue-specific conditional PKCε knockout mice: a model to precisely reveal PKCε functional role in initiation, promotion and progression of cancer

Evidence from our laboratory and others indicate that PKCe is a transforming oncogene and a predictive biomarker of various human cancers including prostate, breast, head and neck, lungs, brain, bladder and cutaneous squamous cell carcinoma (SCC). However, a precise in vivo link of PKCe and its downstream signaling components to cancer induction, progression and metastasis remain undefined. To achieve these goals, we generated tissue specific conditional PKCe knockout mice using cre-lox technology. To do so, we generated a targeting vector in which Exon 4 of the PKCe gene was flanked by LoxP sites. This vector was used to generate mice carrying two floxed alleles of PKCe (PKCeLoxP/LoxP mice) by standard gene knockout methodology. Homozygous PKCeLoxP/LoxP mice have normal body weight and phenotype. To determine what effect loss of PKCe would have on the prostrate, the PKCeLoxP/LoxP mice were bred to prostate specific cre (PB-Cre4+). Western blot and immunohistochemical analyses showed inhibition of PKCe protein level in the prostate of PKCe-KO mice. However, no change in the PKCe protein level was observed in the spleen, liver and lungs of PKCe-KO mice. Also, PKCe deletion in prostate did not affect the levels of other PKC isoforms (PKCα, PKCβII, and PKCς). No significant difference was observed in the prostate weight of PKCeLoxP/LoxP and PKCe-KO mice. Histopathological analyses of prostate from both PKCeLoxP/LoxP and prostate PKCe-KO mice showed normal pathology in the PKCe-KO prostate. To determine the functional impact of prostate specific deletion of PKCe on prostate tumor growth, we performed an orthotopic xenograft study. In this experiment, TRAMP mouse tumor cells (TRAMPC1, 2×106) were implanted in the prostate. Mice were sacrificed at 6 weeks post-implantation. Results demonstrated a significant (P Citation Format: Bilal B. Hafeez, Louise Meske, Anupama Singh, Ashok Singh, Weixiong Zhong, Patricia Powers, Manorama John, Anne Griep, Ajit Verma. Tissue-specific conditional PKCe knockout mice: a model to precisely reveal PKCe functional role in initiation, promotion and progression of cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-137. doi:10.1158/1538-7445.AM2015-LB-137