Purpose To carry out an integrative profile of human pancreatic ductal adenocarcinoma (PDAC) to identify prognosis-significant genes and their related pathways. Experimental Design A concordant survival-based whole genome in silico array analysis of DNA copy number, and mRNA and miRNA expression in 25 early-stage PDAC was carried out. A novel composite score simultaneously integrated gene expression with regulatory mechanisms to identify the signature genes with the most levels of prognosis-significant evidence. The predominant signaling pathways were determined via a pathway-based approach. Independent patient cohorts (n = 148 and 42) were then used as in vitro validation of the array findings. Results The composite score identified 171 genes in which expressions were able to define two prognosis subgroups (P = 3.8e-5). Eighty-eight percent (151 of 171) of the genes were regulated by prognosis-significant miRNAs. The phosphoinositide 3-kinase/AKT pathway and SRC signaling were densely populated by prognosis-significant genes and driven by genomic amplification of SRC and miRNA regulation of p85α and CBL. On tissue microarray validation (n = 148), p85α protein expression was associated with improved survival for all patients (P = 0.02), and activated P-SRC (Y418) was associated shorter survival for patients with low-grade histology tumors (P = 0.04). Interacting P-SRC and p85α revealed that they define two distinct PDAC patient subgroups (P = 0.0066). Furthering the importance of these pathways, CBL protein expression was associated with improved survival (P = 0.03) on a separate cohort (n = 42). Conclusions These pathways and related genes may represent putative clinical biomarkers and possible targets of individualized therapy in the distinct patient subgroups they define.

A major challenge in stem-cell mediated regenerative medicine is the development of defined culture systems for the maintenance of clinical-grade human embryonic stem (hES) cells. Using a feedback system control scheme, we identified a unique combination of three small molecule inhibitors that enables the maintenance of hES cells on a fibronectin-coated surface through single cell passaging. After 20 passages, the undifferentiated state of the hES cells was confirmed by OCT4, SSEA4 and NANOG expressions, while their pluripotent potential and genetic integrity were demonstrated by teratoma formation and normal karyotype, respectively. Our study attests to the power of feedback system control scheme in quickly pinpointing optimal conditions for desired biological activities and provides a chemically defined, scalable and single cell passaging culture system for hES cells.

New therapies for late stage and castration resistant prostate cancer (CRPC) depend on defining unique properties and pathways of cell sub-populations capable of sustaining the net growth of the cancer. One of the best enrichment schemes for isolating the putative stem/progenitor cell from the murine prostate gland is Lin-;Sca1+;CD49fhi (LSChi), which results in a more than 10-fold enrichment for in vitro sphere-forming activity. We have shown previously that the LSChi subpopulation is both necessary and sufficient for cancer initiation in the Pten-null prostate cancer model. To further improve this enrichment scheme, we searched for cell surface molecules upregulated upon castration of murine prostate and identified CD166 as a candidate gene. CD166 encodes a cell surface molecule that can further enrich sphere-forming activity of WT LSChi and Pten null LSChi. Importantly, CD166 could enrich sphere-forming ability of benign primary human prostate cells in vitro and induce the formation of tubule-like structures in vivo. CD166 expression is upregulated in human prostate cancers, especially CRPC samples. Although genetic deletion of murine CD166 in the Pten null prostate cancer model does not interfere with sphere formation or block prostate cancer progression and CRPC development, the presence of CD166 on prostate stem/progenitors and castration resistant sub-populations suggest that it is a cell surface molecule with the potential for targeted delivery of human prostate cancer therapeutics.