E-Poster Presentation ESA-SRB-ANZBMS 2021

Differential gene expression analysis after PPARγ activation and XIAP inhibition identifies upregulation of metabolic processes in KGN cells (#311)

Trang Tran 1 , Trang Nguyen 1 , Dilys Leung 2 , Maria Alexiadis 1 , Ashleigh Carolan 1 3 , Orlen Mulia 1 4 , Peter J Fuller 1 , Simon Chu 1
  1. Hudson Institute of Medical Research, Clayton, VIC, Australia
  2. Cabrini Monash University, Department of Medical Oncology, Cabrini Health, Malvern, VIC, Australia
  3. Medicine, Monash University, Clayton, VIC, Australia
  4. Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia

Ovarian granulosa cell tumours (GCT) are hormonally active cancers characterised by indolent growth and late, invasive relapse. Aside from surgery the therapeutic options are very limited. We have previously reported a combination of activating the nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARγ) and inhibiting the X-linked inhibitor of apoptosis protein (XIAP) as a potential specific therapeutic approach for GCT1. PPARγ, which impedes proliferation and promotes terminal differentiation in granulosa cells, is highly expressed in GCT. XIAP is also highly expressed in GCT. As a potent inhibitor of apoptosis, XIAP is an attractive therapeutic target. Combined XIAP inhibition and PPARγ activation results in regulation of several proteins involved in metabolic processes2. The GCT cells eventually undergo apoptosis1. We performed RNA-seq analysis on GCT-derived KGN cells after combined PPARγ activation (rosiglitazone) and XIAP inhibition (Smac-mimetics). Generated RNA-seq libraries were sequenced (average of 50 million reads/sample). Data analysis utilised the RNASik pipeline (Monash Bioinformatics Platform), followed by DEGUST analysis to establish transcriptomic profiles. Preliminary analysis identified 165 differentially expressed genes in PPARγ-activated/XIAP inhibited KGN cells, 70% of which were upregulated (FDR 0.05, fold change>2). Gene Set Enrichment Analysis identified functionally related sets of genes involved in metabolic processes and cytokine-mediated signalling. We further validated the expression of two of the upregulated genes using RT-PCR.  We found that PPARγ activation/XIAP inhibition caused a 12-fold upregulation of CC motif chemokine 20 (CCL20), a cytokine implicated in ovarian follicular cell differentiation. A 9-fold upregulation of Ras related glycolysis inhibitor and calcium channel regulator (RRAD) was also observed. RRAD is a GTP-binding protein and is associated with type II diabetes. Further work is being conducted to understand the basis of this upregulation. This study improves our understanding of the molecular mechanisms in GCT pathophysiology as well as enabling identification of new therapeutic targets.

  1. Leung DTH, Nguyen T, Oliver EM, Matti J, Alexiadis M, Silke J, Jobling TW, Fuller PJ and Chu S. (2019) Molecular Cancer Therapeutics 18(2):364-375.
  2. Leung DTH, Rainczuk A, Nguyen T, Stephens A, Silke J, Fuller PJ, & Chu S. (2019) Journal of Proteome Research. doi: 10.1021/acs.jproteome.8b00917.