UROP Proceedings 2020-21

School of Science Division of Life Science 32 Targeting Mitotic Regulators in Cancer Cells for Potential Treatment Supervisor: POON Randy Yat Choi / LIFS Student: CHING Chi Yin / SSCI Course: UROP1100, Summer It has been found by our laboratory that Programmed death-ligand 1 (PD-L1) express a second band (other than the normal band show in interphase) in Western blot during mitosis. We suspect that PD-L1 may possess a certain function in the mitotic state. We would like to investigate the identity of the second band by transfecting various modified clones of the PD-L1 gene. Prior to this, we have to confirm that the transfected PD-L1 shows a similar pattern as the endogenous one. This study mainly focuses on evaluating the potential of HeLa being the model for future experiments. Unfortunately, the result indicates that transfected HeLa shows a different PD-L1 expression pattern than the normal cell line. Therefore, it is not a suitable option for the future experiments. Targeting Mitotic Regulators in Cancer Cells for Potential Treatment Supervisor: POON Randy Yat Choi / LIFS Student: LIAO Man Kit / CHEM Course: UROP2100, Summer The Spindle Assembly Checkpoint (SAC) and Mitotic Checkpoint Complex (MCC) are important components during mitotic arrest. In the absence of microtubule attachment to kinetochore, a cascade of signal leads to activation of SAC and then the MCC. Inhibition of the Anaphase-Promoting Complex (APC/C) by MCC enables the cells to stay in mitosis. Previous studies suggested that MAD1 and BUB1 are key components of the SAC and plays a crucial role in this activation of the MCC. Using a conditional system to deplete MAD1 and BUB1 respectively, however, indicated that MCC complex can still form and cells can still be arrested in mitosis for a shorter period of time in the absence of MAD1 or BUB1. These results suggested that both MAD1 and BUB1 may not be as crucial for the SAC as once thought. Cloning and Characterization of Novel Cytoskeletal Regulators Supervisor: QI Robert Zhong / LIFS Student: PARK Joo Hyoung / BIOT Course: UROP1100, Fall Microtubules are a type of cytoskeletal network which plays an important role in the transportation of cellular materials and structural support of the cell. These microtubules are generated at sites known as the microtubule organizing centers (MTOCs), with its nucleation beginning at the γ-tubulin ring complexes (γTuRC). The γ-TuRC is a built with γ-tubulin proteins and various γ-tubulin complex proteins (GCP). This report covers the cloning of C-terminal EGFP tagged GCPs into pEGFP-N3 vectors and transformation into bacteria, with the final goal being to compare C-terminal tagged GCPs to N-terminal tagged GCPs in order to determine if it is the GCPs or tagged EGFPs cause interference with regular γ-TuRC function.