Oral Presentation 6th Australian Health and Medical Research Congress 2012

Development of an in vitro assay to screen new gene aberrations identified through genomic analysis of pancreatic tumours as possible drivers of early carcinogenesis (#132)

Andreia V. Pinho 1 , APGI Australian Pancreatic Cancer Genome Initiative 1 , Andrew V. Biankin 1 , Ilse Rooman 1
  1. Garvan Institute of Medical Research, Darlinghurst, NSW, Australia

Background: Pancreatic Ductal Adenocarcinoma (PDAC) is a deadly tumour, presenting a median survival of 6 months. A window of opportunity for early detection exists in the preneoplastic lesion stages, which are taught to evolve from acinar to ductal metaplasia (ADM)1.

Our group is a member of the International Cancer Genome Consortium (ICGC), being responsible for generating the world’s largest catalogue of human PDAC genomic abnormalities. The analysis of the first 100 tumour samples has been completed and a list of novel candidate genes has emerged which requires further biological testing2.

Our aim is to develop an in vitro screening assay using mouse pancreatic cells that can evaluate whether these new candidate genomic aberrations identified through the ICGC project are involved in the early stages of pancreatic carcinogenesis.

Methods: To establish our assay, we used previously described PDAC mouse models in which oncogenic KRas is expressed specifically in pancreatic cells, alone (KC) or in combination with mutant p53 (KPC)3. The exocrine tissue of young, pre-diseased animals was isolated and cultured4 and several endpoints were examined.

Results: Histological analysis of pancreata from young KC and KPC mice revealed only the presence of small preneoplastic lesions. Nevertheless, after isolation and within a 5-day culture period, the exocrine cells derived from KC and KPC mice presented a progressively increased ability for plate adherence and proliferation. Moreover, the cultures derived from cancer-prone mice displayed upregulated markers for ADM, stem cell and cell cycle markers.

Conclusions: We have established a fast and simple in vitro assay that allows to determine whether a genetic aberration predisposes the mouse pancreas to develop cancer, overcoming long observational studies to assess tumour initiation in vivo. This method is being used as an initial screen of multiple ICGC candidate genes for a role in early pancreatic carcinogenesis.

  1. Rooman I, Real FX. Pancreatic ductal adenocarcinoma and acinar cells: a matter of differentiation and development? Gut 2012;61:449-58.
  2. Biankin AV et al. Pancreatic Cancer Genomes Reveal Aberrations in Axon Guidance Pathway Genes. Under review
  3. Hingorani SR, Wang L, Multani AS, et al. Trp53R172H and KrasG12D cooperate to promote chromosomal instability and widely metastatic pancreatic ductal adenocarcinoma in mice. Cancer Cell 2005;7:469-83
  4. Pinho AV, Rooman I, Reichert M, et al. Adult pancreatic acinar cells dedifferentiate to an embryonic progenitor phenotype with concomitant activation of a senescence programme that is present in chronic pancreatitis. Gut 2011;60:958-66