Identifying Intestine Specific Homeobox gene ISX as a biomarker and therapeutic target for metastatic pancreatic cancer: developing spontaneous progression models displaying stage-specific genomic changes

Purpose: Majority of pancreatic cancer (PDAC) patient deaths are associated to the metastatic progression of disease. To identify novel targeted-therapies, a complete understanding of transformation in genetic landscape in tumors during disease progression is needed. Widely in use, the artificially immortalized PDAC cell lines do not rightly represent the progression because of multiple donors and disparate genetic characteristics. To identify key genes underlying the progression of PDAC from localized disease to a metastatic form, we performed whole transcriptome RNA-Sequencing analysis of cell models representing localised to metaststic stage through paired-end deep sequencing Method: Mouse expressing a Cre-activated KrasG12D allele inserted into the endogenous Kras locus, and these mice were crossed with mice expressing Cre recombinase in pancreatic tissue by virtue of a PDX-1 promoter-driven transgene. Next a cross between K-rasG12D Pdx-Cre and p16-/- mice, transgenic K-rasG12D Pdx-Cre p16-/- mice were generated harboring tissue specific mutant Kras and p16 deletion resulting in an earlier appearance of PanIN lesions followed by rapid progression into highly invasive and metastatic pancreatic cancers. Results: Transgenic K-rasG12D Pdx-Cre p16-/- mice developed spontaneous- localized, invasive and metastatic pancreatic tumors and transcriptome of these cell models representing localized, invasive and metastatic pancreatic tumors were sequenced. Conclusions: Based on genetic analysis of a same-lineage genetic background cell models, this study identifies a novel molecular pathway underlying the progression of pancreatic cancer disease. This study shows that Intestine Specific Homeobox (ISX) gene is a novel biomarker unique to pancreatic cancer progression. Overall design: By using tumors from K-rasG12D/p16-/- transgenic mice, we generated a spectrum of spontaneous (without immortalization) murine cell models representing localized (HI-Panc-L), invaise (HI-Panc-I) and metastatic (HI-Panc-M) stages. HI-Panc progression model is a valuable tool and by studying gene expression during progression of pancaretic cancer from localised to metaststic stage in a genetically same linaege wll be beneificail for pancartic cancer reaserch.

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Ganaie AA, Parray A, Hussain T, Shabaneh A, Jamroze A, Ferrari MG, Wang L, Liao DJ, Koochekpour S, Nanda S, Wang J, Deng Y, Gradilone SA, Hinchcliffe EH, Konety BR, Saleem M