| Background and ObjectivePancreatic neuroendocrine tumors(PNETs)are the most common types of neuroendocrine tumors in China.The incidence of PNETs is not high,but because of its early symptoms hidden,there are not many patients who can detect and receive early surgical treatment.And later often accompanied by liver and other parts metastases,surgical treatment is difficult to achieve patient expectations.Traditional radiotherapy and chemotherapy are inefficiently treated with PNETs and are difficult to meet clinical needs.PNETs is a vascular-rich tumor,and angiogenesis plays a very important role in its development.Anti-angiogenesis has gradually become one of its main therapeutic strategies.Molecular targeted drug sunitinib has been approved for the treatment of PNETs.However,clinical observation showed that patients with sunitinib,after obtaining a short benefit,the tumor invasion ability but increased,more prone to metastasis.Suggesting that it is necessary to find new anti-angiogenic targets.Neuropilin2(NRP2)is expressed in tumor cells such as melanoma,neuroblastoma and glioblastoma.At present,it has been reported that the expression of NRP2 in ischemic tissue is increased.NRP2 may participate in the repair of physiological blood vessels.NRP2 overexpression is also found in diseases such as rheumatoid arthritis and other features characterized by enhanced angiogenesis.Suggesting that it may participate in pathological angiogenesis possible.However,the expression of NRP2 in pancreatic neuroendocrine tumors and its effect on angiogenesis have not been reported.This study was to explore the expression of NRP2 in PNETs and the angiogenesis of PNETs,which is expected to provide a new idea for the anti-vascular therapy of PNETs.Methods1.Immunohistochemistry was used to detect the expression of NRP2 and CD31 in human pancreatic neuroendocrine tumors.2.Establish BON-1 cell NRP2 deficient cell lines,detect the expression of NRP2 in control and intervention cells by Western blot.3.CCK-8 was used to assay the proliferation of endothelial cells co-cultured with control and intervention cells.4.Cell migration assay was used to assay the migration of endothelial cells co-cultured with control and intervention cells.5.Tube formation assay was used to assay the tube formation ability of endothelial cells co-cultured with control and intervention cells.Results1.Immunohistochemical staining showed that NRP2 was highly expressed in human pancreatic neuroendocrine tumors and was low in adjacent tissues.The expression of NRP2 was positively correlated with CD31.2.CCK-8 showed no significant difference in HUVEC cell proliferation between the control group and the intervention group(p> 0.05): the control group is 0.35±0.04,while the intervention group is 0.32±0.04.3.Transwell assay showed that the invasion of HUVEC treated with NRP2 silenced group medium was significantly lower:the control group is 203±13,while the silenced group is 100±10(P<0.01).Scratch test results: the healing distance of the control group was 654 ± 29,the interference group was 367 ± 24(P <0.01).4.Tubule formation assay showed that NRP2 silenced group medium treated HUVEC form less tubule:the control group is 40±5,while the silenced group is 24±3(P<0.01).Conclusion1.The results showed that the expression of NRP2 in pancreatic neuroendocrine tumors was significantly higher than that in adjacent pancreatic tissues,and its expression was positively correlated with vascular density,suggesting that the growth of PNETs was closely related to angiogenesis;2.Further studies have shown that deletion of NRP2 in PNETs has no effect on the proliferation of tumor-associated vascular endothelial cells,but can inhibit its migration and tubing ability and inhibit the angiogenesis of PNETs.Its mechanism of action to be more experimental evidence confirmed.To sum up,we believe that NRP2 can be used as a new diagnostic target.By inhibiting the expression of NRP2 in PNETs,inhibiting angiogenesis,and thus inhibiting tumor growth. |
PDF Full Text Request