Breast cancer is the most prevalent non-cutaneous malignancy, afflicting greater than one in ten women in the United States. Aberrant proliferation is a hallmark of cancer, and extensive study has demonstrated that specific cell cycle regulatory pathways are involved in the etiology, progression and treatment of breast cancer. Cyclin D1 is a proto-oncogene that is strongly implicated in breast cancer development and disease progression. Amplification of the cyclin D1 locus occurs in 10-15% of invasive breast cancer, and over expression of cyclin D1 protein is observed in approximately 50% of breast carcinomas. Cyclin D1 plays an important function in mammary tumor genesis, as mice deficient in cyclin D1 are resistant to tumor formation driven by specific oncogenes, while enforced expression of cyclin D1 can lead to mammary carcinoma. In spite of these findings, a number of important questions remain regarding the involvement of cyclin D1 in breast cancer;particularly with reference to disease severity, response to therapy and overall patient survival. It is now apparent that cyclin D1 actually exists in two isoforms, conventional cyclin D1 which has been the subject of all prior investigation in breast cancer and cyclin D1b. Cyclin D1b is produced as an alternative splicing product of the cyclin D1 gene and results in the loss of critical regulatory motifs in the C-terminus. The production of cyclin D1b is believed to be related to a common polymorphism that has been associated with enhanced cancer risk and poor clinical outcome. Importantly, we and others have found that cyclin D1b is distinct from cyclin D1 in nuclear localization, catalytic function, and oncogenic potential. These studies suggested that cyclin D1 isoforms hold unique functions that are of high- relevance to cancer. New preliminary data demonstrate that like cyclin D1, cyclin D1b protein is aberrantly expressed in a significant fraction of breast cancer cell lines and primary tumors. Cyclin D1b protein levels are controlled in a manner distinct from cyclin D1, and evade negative regulation elicited by multiple anti- proliferative signals. Critically, the pathological overproduction of specifically cyclin D1b bypasses estrogen receptor antagonists in models for ER-positive breast cancer. Furthermore, elevated cyclin D1b protein levels in primary breast cancer is associated with increased risk for distant metastasis, disease recurrence, and poor survival. In total, these finding support the hypothesis that the two cyclin D1 isoforms provide distinct activities relevant to breast cancer tumor genesis and therapeutic bypass. The following three aims are designed to test this hypothesis:

Public Health Relevance

Breast cancer is a leading cause of female cancer death in this country. It is known that the cyclin D1 gene plays a large role in breast cancer formation and progression. Overexpression of this gene occurs in over 50% of breast cancers, and stimulates progression of the disease. Strikingly, it is know that the single cyclin D1 gene can result in the production of two different protein products, cyclin D1a and cyclin D1b. While these two protein products have some similarities, only cyclin D1a has been studied with regard to function in breast cancer. While very little is known about cyclin D1b, we have found that cyclin D1b is actually a much more potent tumor-promoting agent, can compromise therapeutic response in model systems, and is associated with poor prognosis. Given this information, it is essential to decipher the impact of cyclin D1b on breast cancer development, progression and response to therapy.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA137494-01A2
Application #
8015349
Study Section
Special Emphasis Panel (ZRG1-OBT-N (02))
Program Officer
Hildesheim, Jeffrey
Project Start
2010-08-01
Project End
2015-01-31
Budget Start
2010-08-01
Budget End
2011-01-31
Support Year
1
Fiscal Year
2010
Total Cost
$160,501
Indirect Cost
Name
Thomas Jefferson University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
053284659
City
Philadelphia
State
PA
Country
United States
Zip Code
19107
Casimiro, Mathew C; Di Sante, Gabriele; Di Rocco, Agnese et al. (2017) Cyclin D1 Restrains Oncogene-Induced Autophagy by Regulating the AMPK-LKB1 Signaling Axis. Cancer Res 77:3391-3405
Kong, Deguang; Liu, Yu; Liu, Qian et al. (2016) The retinal determination gene network: from developmental regulator to cancer therapeutic target. Oncotarget 7:50755-50765
Di Sante, Gabriele; Casimiro, Mathew C; Pestell, Timothy G et al. (2016) Time-Lapse Video Microscopy for Assessment of EYFP-Parkin Aggregation as a Marker for Cellular Mitophagy. J Vis Exp :
Casimiro, Mathew C; Di Sante, Gabriele; Ju, Xiaoming et al. (2016) Cyclin D1 Promotes Androgen-Dependent DNA Damage Repair in Prostate Cancer Cells. Cancer Res 76:329-38
Knudsen, Erik S; McClendon, A Kathleen; Franco, Jorge et al. (2015) RB loss contributes to aggressive tumor phenotypes in MYC-driven triple negative breast cancer. Cell Cycle 14:109-22
Chen, Ke; Wu, Kongming; Jiao, Xuanmao et al. (2015) The endogenous cell-fate factor dachshund restrains prostate epithelial cell migration via repression of cytokine secretion via a cxcl signaling module. Cancer Res 75:1992-2004
Casimiro, Mathew C; Velasco-Velázquez, Marco; Aguirre-Alvarado, Charmina et al. (2014) Overview of cyclins D1 function in cancer and the CDK inhibitor landscape: past and present. Expert Opin Investig Drugs 23:295-304
Ju, Xiaoming; Casimiro, Mathew C; Gormley, Michael et al. (2014) Identification of a cyclin D1 network in prostate cancer that antagonizes epithelial-mesenchymal restraint. Cancer Res 74:508-19
Sun, X; Jiao, X; Pestell, T G et al. (2014) MicroRNAs and cancer stem cells: the sword and the shield. Oncogene 33:4967-77
Witkiewicz, A K; Cox, D W; Rivadeneira, D et al. (2014) The retinoblastoma tumor suppressor pathway modulates the invasiveness of ErbB2-positive breast cancer. Oncogene 33:3980-91

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