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As shown by genomic studies, colorectal cancer (CRC) is a highly heterogeneous disease, where copy number alterations (CNAs) may greatly vary among different patients. To explore whether CNAs may be present also in histologically normal tissues from patients affected by CRC, we performed CGH + SNP Microarray on 15 paired tumoral and normal samples. Here, we report for the first time the occurrence of CNAs as a common feature of the histologically normal tissue from CRC patients, particularly CNAs affecting different oncogenes and tumor-suppressor genes, including some not previously reported in CRC and others known as being involved in tumor progression. Moreover, from the comparison of normal vs paired tumoral tissue, we were able to identify three groups: samples with an increased number of CNAs in tumoral vs normal tissue, samples with a similar number of CNAs in both tissues, and samples with a decrease of CNAs in tumoral vs normal tissue, which may be likely due to a selection of the cell population within the tumor. In conclusion, our approach allowed us to uncover for the first time an unexpected frequency of genetic alteration in normal tissue, suggesting that tumorigenic genetic lesions are already present in histologically normal colonic tissue and that the use in array comparative genomic hybridization (CGH) studies of normal samples as reference for the paired tumors can lead to misrepresented genomic data, which may be incomplete or limited, especially if used for the research of target molecules for personalized therapy and for the possible correlation with clinical outcome., Competing Interests: Compliance with ethical standards Conflicts of interest None

Several studies have shown that there is a paucity of immune cells within the stroma of pancreatic adenocarcinoma, a very aggressive cancer with a median survival of about 18 months. A 65-year-old man presented with jaundice. Abdominal ultrasound revealed intra- and extrahepatic bile duct dilatation and a 45-mm diameter hypoechoic solid mass within the pancreatic head; a computed tomography scan excluded vascular infiltration and metastatic lesions. The patient received immunotherapy consisting of 6,000,000 IU human recombinant interleukin-2 administered subcutaneously twice a day for 3 consecutive days. Thirty-six hours after the last dose, he underwent a pylorus-preserving pancreatoduodenectomy. Because of the presence of high-grade dysplasia detected by intraoperative histological examination of a distal section, a spleen preserving total pancreatectomy was performed. The postoperative course was uneventful. The patient died 32 months after surgery because of local recurrence. Histopathology showed G3 pancreatic ductal adenocarcinoma infiltrating the anterior and posterior peripancreatic tissue, duodenal wall and intrapancreatic common bile duct, with sarcoma-like foci and a component of intraductal tumor involving the common bile duct. In the distal pancreas, widespread foci of pancreatic intraepithelial neoplasia (PanI2-3) were found. The Ki-67 proliferation index was 16%. TNM staging was pT3 pN1 R1. Sections were immunostained for the T-lymphocyte marker CD3 and for the dendritic cell marker CD1a. Intratumoral infiltration was high for CD1a+ cells and mild for CD3+ cells. Preoperative immunotherapy with interleukin-2 may contribute to massive stromal infiltration of immune cells in pancreatic adenocarcinoma. This may prolong the survival even in the presence of negative prognostic factors (age >65 years, tumor diameter >20 mm, R1, tumor grade G3).

In this study, we have evaluated 11 pancreatic tumor cell lines and tumor cells from surgical samples of patients with pancreatic adenocarcinoma for expression of the chemokine receptor CXCR4. Six of 11 cell lines expressed detectable mRNA of CXCR4, with three cell lines (AsPC1, Capan1, and Hs766T) having substantial amounts of transcripts. Expression was higher in lines derived from metastatic lesions compared with those derived from primary tumors. Different inflammatory cytokines did not modify expression, whereas IFN-gamma down-regulated and hypoxia up-regulated CXCR4 transcripts. Transcript expression was associated with surface expression in pancreatic carcinoma cell lines. All surgical carcinoma samples tested expressed higher levels of CXCR4 than normal pancreatic ducts, which were used as reference tissue. The chemokine CXCL12 induced chemotaxis in CXCR4-positive pancreatic carcinoma cell lines, which was inhibited by anti-CXCR4 monoclonal antibody and by the antagonist AMD3100. Transendothelial migration, Matrigel invasion, and activation of matrix metalloproteases were also enhanced by CXCL12. In CXCR4-positive cell lines, CXCL12 stimulated cell proliferation. The cell line Hs766T produces high levels of CXCL12, and addition of the CXCR4 antagonist AMD3100 partially inhibited proliferation, indicating an autocrine loop. Moreover, the addition of exogenous CXCL12 inhibited apoptosis induced by serum starvation. These results indicate that the CXCR4 receptor is frequently expressed in metastatic pancreatic tumor cells. CXCR4 not only stimulates cell motility and invasion but also promotes survival and proliferation. Strategies to target CXCR4 expressed on tumor cells may be of benefit in patients with pancreatic cancer.

The GNA15 gene is ectopically expressed in human pancreatic ductal adenocarcinoma cancer cells. The encoded Gα15 protein can promiscuously redirect GPCR signaling toward pathways with oncogenic potential. We sought to describe the distribution of GNA15 in adenocarcinoma from human pancreatic specimens and to analyze the mechanism driving abnormal expression and the consequences on signaling and clinical follow-up. We detected GNA15 expression in pre-neoplastic pancreatic lesions and throughout progression. The analysis of biological data sets, primary and xenografted human tumor samples, and clinical follow-up shows that elevated expression is associated with poor prognosis for GNA15, but not any other GNA gene. Demethylation of the 5′ GNA15 promoter region was associated with ectopic expression of Gα15 in pancreatic neoplastic cells, but not in adjacent dysplastic or non-transformed tissue. Down-modulation of Gα15 by shRNA or CRISPR/Cas9 affected oncogenic signaling, and reduced adenocarcimoma cell motility and invasiveness. We conclude that de novo expression of wild-type GNA15 characterizes transformed pancreatic cells. The methylation pattern of GNA15 changes in preneoplastic lesions coincident with the release a transcriptional blockade that allows ectopic expression to persist throughout PDAC progression. Elevated GNA15 mRNA correlates with poor prognosis. In addition, ectopic Gα15 signaling provides an unprecedented mechanism in the early steps of pancreas carcinogenesis distinct from classical G protein oncogenic mutations described previously in GNAS and GNAQ/GNA11. [ABSTRACT FROM AUTHOR]