Effects of bone marrow on the microenvironment of the human pancreatic islet: A Protein Profile Approach.

Stem cells are a new therapeutic modality that may support the viability and function of human organs and tissue. Our previous studies have revealed that human allogeneic bone marrow (BM) sustains pancreatic ß cell function and survival. This paper examines whether BM creates a microenvironment that supports human pancreatic islets in vitro by evaluating 107 proteins in culture media from BM, islet, and islet/bone marrow (IB) with mass spectrometry. Proteins were considered up- or down-regulated if p-values < 0.05 and fold change was greater than 2 fold I VS. IB. In addition, proteins identified that were uniquely found in islets co-cultured with bone marrow, but not in islets or bone marrow. A 95% protein probability was used as a threshold. Twenty three proteins were upregulated, and sixteen proteins were downregulated. The function of each protein is listed based on the protein database, which include structural proteins (9 upregulated, 4 downregulated); anti-protease and anti-endopeptidase enzymes (8 upregulated); cation binding proteins (6 up-regulated). Six proteins were uniquely identified in islet co-cultured with bone marrow. Three are anti-proteases or anti-endopeptidases, and 1 is a structural protein. These findings suggest that BM, by changing culture media proteins, may be one of mechanisms to maintain human islet function and survival.

Prognostic microRNA expression signature from examination of colorectal primary and metastatic tumors.

While previous studies have described associations between specific microRNAs and colorectal cancer (CRC) metastasis, our understanding of microRNA regulation of metastatic spread remains largely unexplored. To identify microRNAs critical for disease progression, we measured microRNA expression in primary CRC tumors and synchronous liver metastases in 19 cases using quantitative polymerase chain reaction (qPCR) arrays. We identified 16 microRNAs significantly differentially expressed between primary tumors and liver metastases that distinguish primary tumors and liver metastases by hierarchical clustering. Combinations of microRNAs expressed in the primary tumor and in the metastatic tumor are associated with survival, but these signatures have no microRNAs in common. We found that increased expression of miR-210 and miR-133b in liver metastases compared to primary tumors is associated with lower survival. We propose that evaluating the change in expression between primary and metastatic tumors in each patient may lead to improved biomarker development.

Expression profiling of primary and metastatic ovarian tumors reveals differences indicative of aggressive disease.

The behavior and genetics of serous epithelial ovarian cancer (EOC) metastasis, the form of the disease lethal to patients, is poorly understood. The unique properties of metastases are critical to understand to improve treatments of the disease that remains in patients after debulking surgery. We sought to identify the genetic and phenotypic landscape of metastatic progression of EOC to understand how metastases compare to primary tumors. DNA copy number and mRNA expression differences between matched primary human tumors and omental metastases, collected at the same time during debulking surgery before chemotherapy, were measured using microarrays. qPCR and immunohistochemistry validated findings. Pathway analysis of mRNA expression revealed metastatic cancer cells are more proliferative and less apoptotic than primary tumors, perhaps explaining the aggressive nature of these lesions. Most cases had copy number aberrations (CNAs) that differed between primary and metastatic tumors, but we did not detect CNAs that are recurrent across cases. A six gene expression signature distinguishes primary from metastatic tumors and predicts overall survival in independent datasets. The genetic differences between primary and metastatic tumors, yet common expression changes, suggest that the major clone in metastases is not the same as in primary tumors, but the cancer cells adapt to the omentum similarly. Together, these data highlight how ovarian tumors develop into a distinct, more aggressive metastatic state that should be considered for therapy development.

Identification of ovarian cancer metastatic miRNAs.

Serous epithelial ovarian cancer (EOC) patients often succumb to aggressive metastatic disease, yet little is known about the behavior and genetics of ovarian cancer metastasis. Here, we aim to understand how omental metastases differ from primary tumors and how these differences may influence chemotherapy. We analyzed the miRNA expression profiles of primary EOC tumors and their respective omental metastases from 9 patients using miRNA Taqman qPCR arrays. We find 17 miRNAs with differential expression in omental lesions compared to primary tumors. miR-21, miR-150, and miR-146a have low expression in most primary tumors with significantly increased expression in omental lesions, with concomitant decreased expression of predicted mRNA targets based on mRNA expression. We find that miR-150 and miR-146a mediate spheroid size. Both miR-146a and miR-150 increase the number of residual surviving cells by 2-4 fold when challenged with lethal cisplatin concentrations. These observations suggest that at least two of the miRNAs, miR-146a and miR-150, up-regulated in omental lesions, stimulate survival and increase drug tolerance. Our observations suggest that cancer cells in omental tumors express key miRNAs differently than primary tumors, and that at least some of these microRNAs may be critical regulators of the emergence of drug resistant disease.

UV radiation suppresses experimental autoimmune encephalomyelitis independent of vitamin D production.

Although the exact cause of multiple sclerosis (MS) is unknown, a number of genetic and environmental factors are thought to influence MS susceptibility. One potential environmental factor is sunlight and the subsequent production of vitamin D. A number of studies have correlated decreased exposure to UV radiation (UVR) and low serum 25-hydroxyvitamin D(3) [25(OH)D(3)] levels with an increased risk for developing MS. Furthermore, both UVR and the active form of vitamin D, 1alpha,25-dihydroxyvitamin D(3), suppress disease in the experimental autoimmune encephalomyelitis (EAE) animal model of MS. These observations led to the hypothesis that UVR likely suppresses disease through the increased production of vitamin D. However, UVR can suppress the immune system independent of vitamin D. Therefore, it is unclear whether UVR, vitamin D, or both are necessary for the putative decrease in MS susceptibility. We have probed the ability of UVR to suppress disease in the EAE model of MS and assessed the effect of UVR on serum 25(OH)D(3) and calcium levels. Our results indicate that continuous treatment with UVR dramatically suppresses clinical signs of EAE. Interestingly, disease suppression occurs with only a modest, transient increase in serum 25(OH)D(3) levels. Further analysis demonstrated that the levels of 25(OH)D(3) obtained upon UVR treatment were insufficient to suppress EAE independent of UVR treatment. These results suggest that UVR is likely suppressing disease independent of vitamin D production, and that vitamin D supplementation alone may not replace the ability of sunlight to reduce MS susceptibility.