Dissecting the molecular and cellular basis of melanoma susceptibility

Several factors strongly influence an individual’s chance of developing melanoma.  Paramount amongst these are the number of moles (nevi) present on the skin, cumulative levels of UV exposure and skin pigmentation phenotype.  Numerous Genome Wide Association Studies (GWAS) we have identified gene variants at a number of loci that are strongly associated with cutaneous nevi (mole) counts, UV damage response and accordingly susceptibility of individuals to develop melanoma.  Currently the functional impact of genetic variants in the genes IRF4, PLA2G6 and MTAP and their relationship with nevi/melanoma formation remains to be determined.   This project will use a powerful tool in the form a cell bank of primary human melanocytes of defined genetic variance and melanoma cell models to explore the functional role of novel genes and their respective genetic variance in melanoma susceptibility.

Hypothesis

We hypothesise that variance at these loci will impact on important cellular functions such as proliferation, UV or oncogene induced senescence and autophagy.  Disruption of these processes through genetic changes at these gene loci will directly influence the propensity of individuals carrying susceptibility variants to acquire higher numbers of nevi with aging and/or display impaired DNA repair responses and hence development of melanoma.

Aims

We will use a range of molecular and cell biology techniques to manipulate melanocyte/melanoma cell gene expression to dissect the functional role of melanoma susceptibility genes.  We have a large cell bank of primary melanocytes that have been identified to carry melanoma susceptibility variants with which to explore the biological role of these proteins and pathways.

Chhabra Y, et al., 2018. ; Genetic variation in IRF4 expression modulates growth characteristics, tyrosinase expression and interferon-gamma response in melanocytic cells. Pigment Cell and Melanoma Research. 31: 51-60.

Praetorius C, et al., 2013. A polymorphism in IRF4 affects human pigmentation through a tyrosinase-dependent MITF/TFAP2A pathway. Cell 155: 1022-1033.

Approaches/skills and techniques

Experimental approaches in this project may include melanocyte/melanoma cell transfection, lentiviral production and transduction, proliferation and invasion assays, cloning, DNA repair assays, proteomic analysis, immunofluorescence and immunohistochemistry.