| Background Pancreatic neuroendocrine tumors (pNET) are rare tumors, however the incidence of pNET is increasing nowadays. As the overall survival of advanced pNET patients are heterogeneous, which ranges from 10 months to more than 10 years, new therapeutic molecular targets are required to predict the prognosis and improve survival outcomes. Thus, researches on exploring specific biomarkers for prognosis and clinical treatment are hotspots. Our previous Protein spectrometry study showed that pNET tumor tissue had a high level of Versican expression; Versican is a ubiquitous component of the extracellular matrix and has a role in tumor progression. The aim of this study is to identify Versican expression in pNET tissue with expended sample size, and retrospectively investigate the prognostic significance of Versican expression in pNET patientsMethods Clinicopathological factors and follow-up data of 127 pNET patients were collected retrospectively during 2005-2010. All patients had the paraffin-embedded samples of tumor tissues; part of them had corresponding paratumorous tissues. Local Versican protein expression was assessed by immunohistochemical (IHC) staining. And the relation among Versican expression with prognosis and clinicopathological factors were planned to be discussed.Results In 127 pNET patients, IHC showed that the positive expression rate of Versican protein in tumor tissues was 75 (59.1%),52(40.9%) negative, and in 46 paratumorous tissues except islet positive expression, all other pancreatic tissue were negative. Versican expression was associated with tumor stage, tumor size and insulinoma type. Univariable analysis revealed that Versican expression level in tumor tissues was associated with disease-free survival (DFS), the higher expression of Versican in pNET tumor tissue was tend to associated with favorable DFS prognosis (log rank, p=0.08). In subgroup analysis, the higher expression of Versican in NO subgroup, G2 or F-pNET subgroup tumor tissue was tend to associated with favorable DFS prognosis (log rank, p=0.072, p=0.056, p=0.061, respectively).And multivariable analysis showed tumor stage and tumor grade were the prognostic factors of pNET patients’survival.Conclusion Our data indicate that Versican expression was significantly associated with tumor stage, tumor size and insulinoma type. Increased level of Versican expression in cancer tissues was correlated with longer DFS of pNET patients. Tumor stage and tumor grade are main prognostic factors of pNET patients survival.Background The extracellular matrix (ECM) has long been recognized, it provides a microenvironment that regulates tumor cell behavior and play an active role in cancer progression and prognosis. Various studies have revealed the impact of individual matrix molecules on tumor progression. Versican (VCAN), a large ECM chondroitin sulfate proteoglycan, regulates cell proliferation, migration and invasion. Versican is also related with the growth of various cancer cells, including cell proliferation, adhesion, migration and angiogenesis. We had previously demonstrated that the expression of Versican was higher in pNET tumor tissue than in the normal pancreatic tissue. And pNET patients with Veriscan positive expression had relative longer disease-free survival. However, the underlying mechanism of Versican-mediated pNET tumor development remains unclear. The aim of this part was to evaluate the molecular mechanism of versican in pNET cells.Methods siRNA method was used to confirm the function of Versican in cells. Human pNET cell line (BON-1) were transfected with synthesized Versican siRNA and siRNA control respectively using lipotransfectine reagent. The transfection efficiency was confirmed by Flow Cytometry and quantitative real-time PCR (qRT-PCR). RT-PCR and Western blot was used to detect the expression level of Versican isoforms in pNET tissue and pNET cells. Cell proliferation was detected through MTS assay. Cell cycle distribution and apoptosis were assessed by flow cytometry. Cell migration was analyzed by Transwell assays. qRT-PCR and Western blot were used to reveal the target genes in Versican associated signal pathway.Results the expression level of Versican VO isoform is highest in pNET tissue as well as in NET cells. Inhibition of Versican by siRNA could significantly enhance the cell proliferation of pNET cell lines compared to siRNA control group(p<0.05), and it also increased G2/M proportion in cell cycle(p<0.05). While no statistical significant difference was found in cell migration between Versican down-regulation and control group(P>0.05). Furthermore, the expression level of p27 was down-regulated in si-Versican group compared to siRNA control groups using western blot, while the CDK2 expression level was increased in si-Versican groups.Conclusion our results indicate Versican VO isoforms is the major constituent in pNET cells and tissues. And Versican de-expression promoted NET cell proliferation and activate cell cycle by p27/CDK2 signal pathway.Background the prognosis of pancreatic neuroendocrine tumors (pNET) is diverse dramatically, and the treatments of advanced pNET are various, too. The data of best strategy are limited. We retrospectively study the medical treatments and clinical outcomes of advanced pNET patients after disease progression, in a single clinical center in China.Methods Data examined included clinicopathological characteristics, medical therapies and outcomes. The system treatments include somatostatin analogs (SSA), chemotherapy (mainly alkylating agents-based regimens), and target therapy (sunitinib, everolimus). Fifty-five advanced pNET patients who accepted medical treatment after disease progression were collected from April 2009 to May 2015.Results The 5-and 10-year overall survival rates were 75%, and 62.5%, respectively. In the first-line therapy, there were 29 patients with advanced pNET received SSA,8 patients received chemotherapy, and 15 patients received targeted therapy. The PFS of SSA and targeted therapy showed no statistic difference (7and 12 months, respectively). In the second line therapy,11 patients used chemotherapy,10 patients used combination therapy, and 12 patients used targeted therapy, the PFS of combination therapy did not show significant difference compared with targeted therapy (10 and 7 months, respectively). The SSA treated PFS of patients with Ki-67 10-20% and patients with Ki-67<10% were 5 and 9 months, respectively (P=0.2). In the subgroup of patients with Ki-67 10-20%, the mPFS of treating chemotherapy(12 months)was slightly longer than that inpatients treating with SSA (5 months), with no statistic difference (P=0.16). and in 18 patients who used sunitinib, In the first-line therapy, the 1 y-PFS%, ORR and DCR are 44.4%,22.2% and 88.9%, respectively, mPFS is 12m; in the post-second line therapy, the 1y-PFS%, ORR and DCR are 43.7%,33.3% and 77.8%, respectively, mPFS is 12m; The outcomes show no difference between first-line therapy and post-second line therapy. Commonly reported any grade adverse events included bone marrow surpression (14/17, 82.4%), diarrhea (9/17,52.9%), proteinuria (8/17,47.1%), hypertension (6/17, 35.3%) and rash(6/17,35.3%). Four dead due to disease progression and the mOS was not reached.Conclusion In advanced progressive pNET patients who received systemic treatment, there is no PFS difference between treatment with SSA and targeted therapy in first line therapy. And second-line combination therapy did not show significant difference compared to other single therapy in PFS. Ki-67 index may influence the selection of SSA in advanced pNET. The efficiency and commonly reported adverse events of Sunitinib were consistent with the known western data. We still need to expand patients’ number to determine the influence of Ki-67 in selecting efficient medical regimens. |
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