Neuroblastoma Research Group
Lab head: Loretta Lau
Location: The Children's Hospital at Westmead
Lab members: L Lau (head)
N-MYC/c-MYC-mediated regulation of the telomerase complex in neuroblastoma
Primary supervisor: Loretta Lau
This laboratory-based project aims to study how the MYC family oncogenes controls the activity of the telomerase enzyme in a childhood cancer called neuroblastoma. The project will take place at the Children’s Cancer Research Unit at The Children’s Hospital at Westmead. Telomerase activity is undesirable in cancer as it prevents telomeres (end of chromosomes) from shortening with each cell division and therefore enables cancer cells to grow indefinitely. The telomerase complex is made up of 3 main components that can affect its enzymatic activity. N-myc and c-myc are members of the MYC family oncogene. Both high telomerase activity and N-myc amplification are associated with poor outcome in neuroblastoma patients.
In this project, we hypothesize that in the presence of N-myc amplification, N-myc increases telomerase activity by affecting the components of telomerase, and in the absence of N-myc amplification, this role is played by c-myc. In this project, 10 neuroblastoma cell lines (5 with N-myc amplification and 5 without N-myc amplification) will be used to elucidate the effects of N-myc and c-myc on telomerase. First, quantitative PCR will be used to measure the expression levels of the different components of the telomerase complex in these cell lines and telomerase activity will be evaluated using the TRAP activity assay. This will allow the relationship between the expression levels of the different components of telomerase, its activity, and N-myc/c-myc levels to be studied. Second, chromatin immunoprecipitation (ChIP) will be utilized to demonstrate the binding of N-myc and c-myc to the promoters of the telomerase components and that this binding correlates with the expression levels of these components. Third, short interfering RNA (siRNA) and overexpression experiments will be used to manipulate N-myc and c-myc levels and to validate that N-myc and c-myc regulate telomerase activity by regulating its components. This project will dissect the complex interactions between the MYC oncogenes and the different telomerase components, which then control the growth of cancer cells. Knowledge from this research will enhance our understanding of neuroblastoma, one of the hardest to cure childhood cancers, and potentially improve the cure rate. This knowledge can also be extended to other cancers where telomerase and MYC have important functions.
Keywords: Cancer, Telomerase, Cell & Molecular Biology