Pancreatic ductal adenocarcinoma (PDAC) remains a lethal disease with a 5-year survival of 4%. A key hallmark of PDAC is extensive stromal involvement, which makes capturing precise tumor-specific molecular information difficult. Here, we have overcome this problem by applying blind source separation to a diverse collection of PDAC gene expression microarray data, which includes primary, metastatic, and normal samples. By digitally separating tumor, stroma, and normal gene expression, we have identified and validated two tumor-specific subtypes including a “basal-like” subtype which has worse outcome, and is molecularly similar to basal tumors in bladder and breast cancer. Furthermore, we define “normal” and “activated” stromal subtypes which are independently prognostic. Our results provide new insight into the molecular composition of PDAC which may be used to tailor therapies or provide decision support in a clinical setting where the choice and timing of therapies is critical.

Jen Jen Yeh and colleagues developed and validated a six-gene signature in patients with pancreatic ductal adenocarcinoma that may be used to better stage the disease in these patients and assist in treatment decisions.

IntroductionMultiple myeloma results from the clonal outgrowth of malignant plasma cells and is primarily confined to the bone marrow (BM). In addition to the direct effect of plasma cells on normal hematopoietic function, myeloma-induced lytic bone disease affects the majority of patients and represents a major comorbidity. [1][2][3] The interaction of malignant plasma cells with the surrounding stromal microenvironment mediated by increased receptor activator of nuclear factor-kappa B ligand (RANKL) production and reduced osteoprotegrin secretion plays a critical role in accelerating osteoclast (OC)-mediated bone resorption and destruction. 4,5 However, the putative role of additional factors of the bone destructive process is currently unknown.Immunologically, the BM possesses several unique properties. It is a reservoir of memory T cells with heightened antigen specificity 6,7 and is capable of effectively priming naive T-cell responses. 8 The non-tumor-bearing marrow also serves as a reservoir of regulatory T cells (Tregs). 9 In multiple myeloma, we have previously shown that marrow infiltrating lymphocytes (MILs) are more effectively activated and expanded, possess greater antitumor activity than peripheral blood lymphocytes (PBLs) from the same patients, and thus represent more suitable T cells for adoptive immunotherapy in this disease. 10,11 Considering these unique features of MILs, we hypothesized that factors must be present within the tumor microenvironment and absent in the non-tumor-bearing host that are critical in facilitating T-cell activation.Beyond the classic Th1 and Th2 subsets of helper T cells, Th17 T cells have recently been identified as important in the response to pulmonary and colonic bacterial infections as well as key mediators of pathology in numerous autoimmune conditions, including rheumatoid arthritis, systemic lupus erythematosis, and inflammatory bowel diseases. 12 These cells represent a newly defined lineage of T lymphocytes capable of producing interleukin-17 (IL-17) but not interferon-␥ (IFN-␥) or IL-4. As such, they are distinct from the canonical Th1 or Th2 lineages. 13 Th17 differentiation is mediated by transforming growth factor-␤ (TGF-␤) and IL-6. 14 In contrast, increased levels of IL-6 suppress Treg formation. 15 The critical role of IL-6 in the suppression of Treg differentiation and promotion of Th17 differentiation 15 raises the possibility that myeloma, known to produce significant amounts of IL-6, could alter the Th17/Treg balance. Considering the role of Th17 cells in autoimmune diseases and their recent implication in the bone destruction observed in rheumatoid arthritis, 16 we sought to determine whether MILs from myeloma patients produced IL-17 and whether this T-cell population contributed to the osteolytic bone disease in multiple myeloma. Methods SamplesBM and PBL samples were obtained from both myeloma patients (N ϭ 68) and normal donors (N ϭ 6) under informed consent in accordance with the Declaration of Helsinki with approval from the Institutional ...

MUC16 (CA125) belongs to a family of high-molecular weight O-glycosylated proteins known as mucins. While MUC16 is well known as a biomarker in ovarian cancer, its expression pattern in pancreatic cancer (PC), the fourth leading cause of cancer related deaths in the United States, remains unknown. The aim of our study was to analyze the expression of MUC16 during the initiation, progression and metastasis of PC for possible implication in PC diagnosis, prognosis and therapy. In this study, a microarray containing tissues from healthy and PC patients was used to investigate the differential protein expression of MUC16 in PC. MUC16 mRNA levels were also measured by RT-PCR in the normal human pancreatic, pancreatitis, and PC tissues. To investigate its expression pattern during PC metastasis, tissue samples from the primary pancreatic tumor and metastases (from the same patient) in the lymph nodes, liver, lung and omentum from Stage IV PC patients were analyzed. To determine its association in the initiation of PC, tissues from PC patients containing pre-neoplastic lesions of varying grades were stained for MUC16. Finally, MUC16 expression was analyzed in 18 human PC cell lines. MUC16 is not expressed in the normal pancreatic ducts and is strongly upregulated in PC and detected in pancreatitis tissue. It is first detected in the high-grade pre-neoplastic lesions preceding invasive adenocarcinoma, suggesting that its upregulation is a late event during the initiation of this disease. MUC16 expression appears to be stronger in metastatic lesions when compared to the primary tumor, suggesting a role in PC metastasis. We have also identified PC cell lines that express MUC16, which can be used in future studies to elucidate its functional role in PC. Altogether, our results reveal that MUC16 expression is significantly increased in PC and could play a potential role in the progression of this disease.

Purpose Mucin expression is a common feature of most adenocarcinomas and features prominently in current attempts to improve diagnosis and therapy of pancreatic cancer and other adenocarcinomas. We investigated the expression of a number of mucin core proteins and associated O-linked glycans expressed in pancreatic adenocarcinoma (PA) – sialyl Tn (STn), Tn, T antigen, sialyl Lewis A (CA19-9), sialyl Lewis C (SLeC), Lewis X (LeX) and sialyl Lewis X (SLeX) – during the progression of pancreatic cancer from early stages to metastatic disease. Experimental Design Immunohistochemical analyses of mucin and associated glycan expression on primary tumor and liver metastatic tumor samples were performed with matched sets of tissues from 40 autopsy patients diagnosed with PA, 14 surgically resected tissue samples, and 8 normal pancreata. Results There were significant changes in mucin expression patterns throughout disease progression. MUC1 and MUC4 were differentially glycosylated as the disease progressed from early PanINs to metastatic disease. De novo expression of several mucins correlated with increased metastasis indicating a potentially more invasive phenotype, and we demonstrate the expression of MUC6 in acinar cells undergoing acinar to ductal metaplasia. A “cancer field-effect” that included changes in mucin protein expression and glycosylation in the adjacent normal pancreas was also seen. Conclusions There are significant alterations in mucin expression and post-translational processing during progression of pancreatic cancer from early lesions to metastasis. The results are presented in the context of how mucins influence the biology of tumor cells and their microenvironment during progression of pancreatic cancer.