Date: Friday, 22 February 2019

Venue: Seminar Room 4, G/F
Laboratory Block, Faculty of Medicine Building
21 Sassoon Road, Hong Kong

Time: 5:00 p.m.

Title: The role of p85β in oncogenesis and drug sensitivity
Speaker: Miss RAO Ling (PhD candidate)

Summary:
The class IA phosphoinositide-3 kinases (PI3Ks), composed of a p110 catalytic subunit and a p85 regulatory subunit, are crucial lipid kinases involved in multiple pathways. Abnormal PI3K signalling cascades caused by genomic alterations of p85 regulatory isoforms have been discovered across cancers. Here, we showed that PIK3R2 (encoding p85β) was frequently amplified in high-grade serous ovarian cancer (OC) patients. These patients with high PIK3R2 levels had decreased survival probabilities. Tumorigenic capabilities of OC cells were attenuated by p85β knockdown but boosted by overexpression, indicating p85β as an oncoprotein. Importantly, the receptor tyrosine kinase AXL was upregulated in OC patients with PIK3R2 amplification. Further studies have revealed the regulatory mechanism and the sensitivity of p85β-overexpressing OC cells to inhibitors of the signalling axis. We propose that p85β level or PIK3R2 status may help to guide molecular stratification of OC patients for anti-cancer therapy.

Title: CRISPR deletion-based screen identifies potential genetic perturbations facilitating EBV genome maintenance in human immortalized epithelial cells
Speaker: Mr. LIU Tengfei (PhD candidate)

Summary:
Epstein-Barr Virus (EBV) infection is highly associated with nasopharyngeal carcinoma (NPC), a common cancer in Southern China and Southeast Asia. EBV infection has been valued as an important etiological factor in the pathogenesis of NPC. Unlike the situation in B cells, EBV infection in human epithelial cells is very inefficient. In our lab, we have established the cell-free EBV infection method, which enables to achieve highly efficient infection in immortalized nasopharyngeal epithelial cells (NPEs). Through this method, we have characterized early events of EBV infection in NPE cells, which was unachievable before. EBV is presented in almost all tumor cells in NPC specimen. However, we found EBV cannot be maintained in NPE cells in culture persistently. We introduced genome-wide CRISPR deletion-based screening to target potential genetic perturbations that favor EBV genome persistent maintenance in NPE cells.

ALL ARE WELCOME