MDA-9/syntenin is essential for factor VIIa-induced signaling, migration, and metastasis in melanoma cells.

Melanoma differentiation associated gene-9 (MDA-9), also known as syntenin, is a novel gene that positively regulates cancer cell motility, invasion, and metastasis through distinct biochemical and signaling pathways, but how MDA-9/syntenin is regulated in response to signals with the extracellular environment and promotes tumor progression is unclear. We now demonstrate that MDA-9/syntenin is dramatically up-regulated by a combination of rFVIIa and factor F(X) in malignant melanoma. Induction of MDA-9/syntenin in melanoma was found to occur in a thrombin-independent signaling pathway and involves the PAR-1/c-Src/Rho GTPases Rac1 and Cdc42/c-Jun N-terminal kinase axis resulting in the activation of paxillin, NF-κB, and matrix metalloproteinase-2 (MMP-2). MDA-9/syntenin physically interacts with c-Src through its PDZ binding motif following stimulation of melanoma cells with rFVIIa and FX. We also document that induction of this signaling pathway is required for TF·FVIIa·Xa-induced cell migration, invasion, and metastasis by melanoma cells. The present finding uncovers a novel role of MDA-9/syntenin as an important TF·FVIIa·Xa/PAR-1-regulated gene that initiates a signaling circuit essential for cell motility and invasion of metastatic melanoma. In these contexts, targeting TF·FVIIa·Xa and its relevant downstream targets such as MDA-9/syntenin, may represent a novel therapeutic strategy to control the evolution of neoplastic cells.

Bone marrow-derived and synovium-derived mesenchymal cells promote Th17 cell expansion and activation through caspase 1 activation: contribution to the chronicity of rheumatoid arthritis.

OBJECTIVE: Th17 cells have been implicated in rheumatoid arthritis (RA). We hypothesized that the interaction of T cells with bone marrow-derived mesenchymal stem cells (BM-MSCs) or with fibroblast- like synoviocytes (FLS) might, with the help of T cell-secreted inflammatory cytokines (i.e., interleukin-17A [IL-17A], tumor necrosis factor α [TNFα], and/or interferon-γ [IFNγ]), promote Th17 cell expansion and activation. METHODS: Peripheral blood mononuclear cells (PBMCs) from healthy blood donors were cocultured with BM-MSCs or FLS from RA patients or osteoarthritis (OA) patients. Cocultures were exposed to phytohemagglutinin with or without IL-17A, TNFα, or IFNγ. Quantitative reverse transcription-polymerase chain reaction analysis, enzyme-linked immunosorbent assay, and cytofluorometry were used to measure IL-17A production. RESULTS: Interaction of PBMCs with BM-MSCs inhibited Th1 and Th2 responses, but promoted Th17 cell expansion, as early as 24 hours, as demonstrated by increases in retinoic acid receptor-related orphan nuclear receptor γ or IL-17A messenger RNA (mRNA) levels, IL-17A secretion levels, and IL-17A-secreting cell frequency, as well as by T cell switching to the Th17 pathway after 2 rounds of stimulation with MSCs. IL-17A production was also increased in PBMCs stimulated with anti-CD3 plus anti-CD28 or in isolated CD3+ or CD45RO+ T cells, thus demonstrating the role of T cell activation. Levels of mRNA for IL-6, IL-8, and IL-1ß were further amplified when T cell-secreted inflammatory cytokines were added. Interestingly, OA FLS or RA FLS also enhanced IL-17A and IL-6 production, but only RA FLS enhanced IFNγ and IL-1ß production. We further demonstrated that MSC-mediated Th17 promotion requires caspase 1 activation by using an inhibitory peptide and measuring its activity. CONCLUSION: We found that the interaction of MSCs or FLS with T cells promotes the activation and expansion of Th17 cells through caspase 1 activation. Since proinflammatory and T cell-secreted inflammatory cytokines are also amplified, this mechanism may participate in the chronicity of RA.

Improving Mutation Screening in Patients with Colorectal Cancer Predisposition Using Next-Generation Sequencing.

Identification of genetic alterations is important for family risk assessment in colorectal cancers. Next-generation sequencing (NGS) technologies provide useful tools for single-nucleotide and copy number variation (CNV) identification in many genes and samples simultaneously. Herein, we present the validation of current Multiplicom MASTR designs of mismatch repair combined to familial adenomatous polyposis genes in a single PCR reamplification test for eight DNA samples simultaneously on a MiSeq apparatus. Blood samples obtained from 224 patients were analyzed. We correctly identified the 97 mutations selected among 48 samples tested in a validation cohort. PMS2 NGS analysis of the eight positive controls identified single-nucleotide variations not detected with targeted referent methods. As NGS method could not discriminate if some of them were assigned to PMS2 or pseudogenes, only CNV analysis with multiplex ligand probe-dependent amplification confirmation was retained for clinical use. Twenty-seven new variants of unknown significance, 21 disease-causing variants, and two CNVs were detected among the 176 patient samples analyzed in diagnosis routine. MUTYH disease-causing mutations were identified in two patient samples assessed for mismatch repair testing, confirming that this method facilitates accurate and rapid individual risk assessments. In one sample, the MUTYH mutation was associated with a MSH6 disease-causing mutation, suggesting that this method is helpful to identify additional cancer risk modifiers and provides a useful tool to optimize clinical issues.

Development of multidisciplinary committees for decision making and care management in hereditary colon cancer: the French state of the art.

Multidisciplinary Committees (MDC) in France were established by the Institut National du Cancer for the management of therapeutic cancer treatment. We wanted to know if this approach is being utilized in Cancer Genetics, in particular for patients with a digestive cancer predisposition. A questionnaire was sent to the 33 French oncogenetic centers. Responses were received from all clinics. We found that 76 % of centers regularly use MDCs for the management of hereditary digestive cancers. Familial colon cancer cases were the most common situation, in which MDCs were utilized. Participation of various medical specialists was reported as follows: geneticists (100 %), gastroenterologists (76 %), genetic counselors (84 %), surgeons (32 %), and biologists (36 %). Twenty percent of centers consult MDCs for every patient compared to 80 % of centers that use MDCs only for select cases. MDCs represent a multidisciplinary approach for patients affected by inherited cancers and may optimize follow-up for genetic screening and further care management.