The Essentiality of Spy1 in Cooperation with Hepatocellular Carcinoma Drivers to Promote Tumour Formation

Liver cancer is the fourth leading cause of cancer-related deaths worldwide, standing at an estimation of 800,000 deaths annually. Among the various subtypes, hepatocellular carcinoma (HCC) is the most common primary liver malignancy. HCC is known to develop through a series of genetic and epigenetic alterations of proto-oncogenes and tumour suppressor genes in the liver environment. These changes ultimately lead to the malignant transformation of hepatocytes, the primary cells of the liver. Various HCC drivers are known to cause disruption of cellular pathways and promote tumour formation. Importantly, several cell cycle mediators cause misregulation, thereby stimulating tumour formation and progression. The cyclin-like protein Spy1, promotes cell cycle progression and overrides apoptosis. Recent reports have detected increased levels of Spy1 in human HCC, which directly correlates to severity of the disease and poor prognosis. We hypothesize that Spy1 plays a critical role along with hepatocellular carcinoma drivers to advance tumour development.  We will test the essentiality of Spy1 on HCC development by first investigating potential gRNAs to use for Spy1 knockout in vivo in the liver, for hydrodynamic tail vein injections in wildtype mice. Simultaneously, in vitro testing of HCC cells (HepG2) will study the importance of Spy1 in HCC cell characteristics in combination with HCC drivers such as c-myc, p53, and ð�›½-catenin. This project will assist in understanding the essentiality of Spy1 in HCC, which may reveal insight into the molecular mechanism of the tumour suppressors and proto-oncogenes connected with this subset of liver cancer.   â€

The Role of Cell Cycle Mediators in the Progression of Non-alcoholic Steatohepatitis in Male and Female Murine Models

Hepatocellular carcinoma (HCC) is the most prevalent primary cancer of the liver and one of the leading causes of cancer-related deaths worldwide. There are a multitude of risk factors that contribute to the development of HCC including viral infection, obesity, alcoholism, as well as non-alcoholic steatohepatitis (NASH). In the case of these chronic diseases and repeated injury, the liver continuously repairs itself to maintain its structural integrity, resulting in fibrosis, and in more serious cases, cirrhosis– major risk factors in the development of HCC. Men are 3-5x more likely to develop liver cancer than women; however, the exact mechanism for this remains undetermined. Previous work in our lab using a transgenic mouse model overexpressing the cyclin-like protein Spy1 showed an increased incidence of HCC and decrease in rates of fibrosis, suggesting a link between cell cycle regulation and progression to HCC. Spy1 binds and activates CDKs at the G1-S and G2-M checkpoints, leading to cell cycle progression independent of cyclin-based regulation. Using a methionine-choline deficient diet to induce NASH, the role of various cell cycle mediators will be investigated to uncover the link between cell cycle regulation and NASH disease progression. In addition, differences between female and male mouse responses to the diet with respect to cell cycle regulation will be analyzed. A better understanding of the relationship between cell cycle regulation and NASH disease progression in both female and male mouse models will help identify novel diagnostic markers and pathways of therapeutic importance in HCC

Spy1 and the Long-Term Effects of Childbearing on the Mammary Gland

N/AThe Role of Spy1 in Exacerbating the Long-Term Effects of Parity on the Mammary Gland Khan, A.1, Fifield, B.1, Porter L.A.1. 1. University of Windsor, Windsor, Ontario. N9B 3P4. Porter Lab, Department of Biomedical Sciences Age is a significant variable in cancer development, and approximately 1/3 of breast cancer cases occur in patients older than 70. Another emerging risk factor is parity, or childbearing, which may be linked to cellular changes that affect a woman’s risk of developing breast cancer over the course of her lifetime. These changes are thought to result from the mammary gland not reverting to normal after lactation and involution - a developmental remodeling process where the milk secreting cells are cleared and replaced with adipocytes after weaning. Aberrant expression of the cyclin-like protein Spy1 has been shown to stimulate precocious development, resulting in disrupted morphology and oncogenesis within the mammary gland. Preliminary data suggests that the mammary glands of mice overexpressing Spy1 do not fully regress following lactation and involution, which may predispose them to breast cancer. We hypothesize that the overexpression of Spy1 exacerbates the long-term effects of parity on mammary gland morphology. To investigate this, we performed hematoxylin and eosin (H&E) staining as well as immunohistochemistry (IHC) on paraffin embedded sections, and whole mount staining of MMTV-Spy1 mice, a transgenic mouse model that overexpresses Spy1 within the mammary gland. We then compared the mammary gland morphology of parous MMTV-Spy1 mice to nulliparous MMTV-Spy1 mice, parous control FVB mice, and nulliparous control FVB mice. This research begins to improve our understanding of Spy1’s role in regulating proliferation and apoptosis, contributes to our overall knowledge of breast cancer dynamics, and further solidifies Spy1 as an important target for treatment