The aberrant over expression and concomitant activation of members of the ErbB family of growth factor receptor tyrosine kinases plays key roles in promoting the growth and progression of a variety of solid tumor types. The long term objective of the proposed studies is to understand the role of a novel protein degradation pathway in regulating ErbB3-induced mammary tumor initiation and progression. The central component of the pathway is a RING finger E3 ubiquitin ligase called Nrdp1 that mediates the ubiquitination of the ErbB3 receptor, thereby promoting its trafficking to degradative cellular compartments. Nrdp1 protein is invariably post-transcription ally suppressed in ErbB2-induced mammary tumors from transgenic mice that over express endogenous ErbB3, and Nrdp1 protein is lost in tumors from almost 60% of breast cancer patients, consistent with a model whereby Nrdp1 loss facilitates ErbB3 protein over expression in tumors. However, recent evidence points to a broader role for Nrdp1 and its associated pathway components in cellular regulation. The hypothesis guiding the proposed studies is that Nrdp1 acts through multiple pathways to maintain mammary epithelial cell integrity, and that the post-transcriptional loss of Nrdp1 protein removes a barrier to mammary tumor initiation. Three critical issues concerning Nrdp1 involvement in mammary epithelial integrity will be addressed. 1) The role of the Nrdp1 pathway-associated deubiquitinating enzyme Otub1 in mediating Nrdp1 post-transcriptional loss in tumor cells will be assessed by viral-mediated over expression and knockdown in cultured cells. In addition, inducible transgenic over expression of Otub1 in the mammary gland will be used to assess its involvement in mammary gland development and ErbB2-induced tumorigenesis. 2) The role of Nrdp1 pathway components in establishing and maintaining the polarity and architecture of cultured epithelial cells will be explored using viral-mediated over expression and knockdown approaches coupled with biochemical assays and immunofluoresecence-based cell structure assays. 3) The role of the Nrdp1 gene in suppressing the onset of ErbB2-induced tumors will be examined using conditional knockout and transplantation approaches. Together, the proposed studies could uncover novel activities for this pathway in mammary tumor development, and underscore its role in mammary tumor suppression.
The proposed studies are aimed at understanding molecular and cellular mechanisms underlying breast cancer initiation and progression. The successful completion of the work could shed light on the biochemical pathways engaged by normal or pre-malignant breast epithelial cells during their transition to a malignant state. Ultimately, the studies could identify novel targets for therapeutic intervention.
|Printsev, Ignat; Curiel, Daniel; Carraway 3rd, Kermit L (2016) Membrane Protein Quantity Control at the Endoplasmic Reticulum. J Membr Biol :|
|Savoy, Rosalinda M; Chen, Liqun; Siddiqui, Salma et al. (2015) Transcription of Nrdp1 by the androgen receptor is regulated by nuclear filamin A in prostate cancer. Endocr Relat Cancer 22:369-86|
|Hatakeyama, Jason; Wald, Jessica H; Printsev, Ignat et al. (2014) Vangl1 and Vangl2: planar cell polarity components with a developing role in cancer. Endocr Relat Cancer 21:R345-56|
|Printsev, Ignat; Yen, Lily; Sweeney, Colleen et al. (2014) Oligomerization of the Nrdp1 E3 ubiquitin ligase is necessary for efficient autoubiquitination but not ErbB3 ubiquitination. J Biol Chem 289:8570-8|
|Rafidi, Hanine; Mercado 3rd, Francisco; Astudillo, Michael et al. (2013) Leucine-rich repeat and immunoglobulin domain-containing protein-1 (Lrig1) negative regulatory action toward ErbB receptor tyrosine kinases is opposed by leucine-rich repeat and immunoglobulin domain-containing protein 3 (Lrig3). J Biol Chem 288:21593-605|
|Hong, Shiao-Ya; Shih, Yi-Ping; Li, Tianhong et al. (2013) CTEN prolongs signaling by EGFR through reducing its ligand-induced degradation. Cancer Res 73:5266-76|
|Liu, Wei; Hsu, Daniel K; Chen, Huan-Yuan et al. (2012) Galectin-3 regulates intracellular trafficking of EGFR through Alix and promotes keratinocyte migration. J Invest Dermatol 132:2828-37|
|Tili, Esmerina; Michaille, Jean-Jacques; Wernicke, Dorothee et al. (2011) Mutator activity induced by microRNA-155 (miR-155) links inflammation and cancer. Proc Natl Acad Sci U S A 108:4908-13|
|Fry, William H D; Simion, Catalina; Sweeney, Colleen et al. (2011) Quantity control of the ErbB3 receptor tyrosine kinase at the endoplasmic reticulum. Mol Cell Biol 31:3009-18|
|Albrecht, Huguette; Carraway 3rd, Kermit L (2011) MUC1 and MUC4: switching the emphasis from large to small. Cancer Biother Radiopharm 26:261-71|
Showing the most recent 10 out of 19 publications