As a newly discovered cytokine, interleukin 9 was initially considered a T-lymphocyte growth factor. Interleukin 9 affects target cells by binding to a member of the γc-family of receptors and is involved in inflammation, autoimmune diseases, and other ailments. In recent years, mounting evidence reveals that interleukin 9 exerts antitumor effects, which has attracted considerable attention. Many previous studies were performed in vivo by establishing a mouse model of melanoma. Here, interleukin 9 protein and messenger RNA expression levels were both low in colon carcinoma tissue specimens, as assessed by immunohistochemistry and quantitative real-time polymerase chain reaction. In addition, interleukin 9 expression in these samples was correlated with TNM staging, Dukes staging, lymph node metastasis, and good prognosis, but not with gender, age, tumor size, tumor differentiation, and hepatic metastasis. In vivo, by establishing a mouse subcutaneous allograft model, we found that interleukin 9 overexpression inhibited tumor growth and resulted in longer survival time. Then, antitumor immune responses were increased by interleukin 9 as demonstrated by flow cytometry. Furthermore, interleukin 9 was shown to exert antitumor effects by regulating T-cell function and killing tumor cells in the tumor microenvironment. Overall, this study revealed that interleukin 9 exerts robust antitumor effects in colon cancer and transforms the tumor microenvironment in vivo.

BackgroudMiR-29a belongs to one of the subtypes of miRNAs known as non-coding single-stranded RNAs, and is preferentially expressed in normal tissues. B7-H3, a member of the B7/CD28 immunoglobulin superfamily, was shown to be overexpressed in several solid malignant tumors, including colon cancer. In

Programmed death receptor ligand 1 (PD-L1), which belongs to the B7 family, is overexpressed in a variety of human cancer types and serves a crucial role in immune escape by malignant cells. Programmed death receptor 1 (PD-1) is a specific PD-L1 receptor. PD-1/PD-L1 signaling inhibits the antitumor effects of dendritic cell (DC) immunization for tumor treatment. The aim of the present study was to determine whether inhibiting PD-L1 may increase the immunologic anti-tumor effect of dendritic cells against pancreatic cancer. In the present study, PD-L1 levels in non-cancerous and malignant tissue samples were compared, and the impact of PD-L1 downregulation on human pancreatic cancer PaTu8988 cells was determined by lentivirus-based RNA interference and DC immunotherapy. PD-L1 expression in pancreatic specimens was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. PaTu8988 cells expressing reduced levels of PD-L1 were generated by lentivirus-based knockdown to assess the mechanism by which the inhibition of PD-L1 signaling in DC immunization affects therapeutic outcomes in pancreatic cancer-bearing SCID-hu mice. PD-L1 levels were markedly elevated in pancreatic adenocarcinoma samples compared with in non-cancerous tissue. PD-L1 silencing in pancreatic adenocarcinoma cells resulted in improved treatment outcomes of DC immunization in vitro and in vivo compared with traditional DC immunization. PD-L1 silencing enhances the antitumor response of cytotoxic T cells by increasing interferon γ production in vitro . In vivo , this method prevented tumor growth and lung metastasis, and prolonged survival in the SCID-hu model. In conclusion, the results of the present study suggested that suppressing PD-L1 in malignant cells during DC immunization may be a useful tool for immunotherapy in pancreatic adenocarcinoma.

Background: The anti-tumor effect of IL-36β mediated activation of CD8+ T cells has been reported, but the molecular mechanism is largely undefined.Methods: IL-36β amounts in pancreatic cancer were examined by qRT-PCR and immunohistochemical staining. Cytology and animal experiments were performed to study the effects of IL-36β on the growth of pancreatic cancer cells. Then we examined the changes of CD8+ T cells and NK cells in the tumor flow-cytometrically. MicroRNA expression profiles were determined by microarray analysis.Results: The results revealed decreased IL-36β amounts in pancreatic cancer tissues. In addition, IL-36β inhibited tumor growth and promoted CD8+ T and NK cell proliferation in the tumor microenvironment. Moreover, IL-36β stimulated CD8+ T cells to synthesize high amounts of IFN-γ and IL-2. Microarray analysis showed that IL-36β administration to human and mouse CD8+ T cells consistently downregulated the miRNA let-7c-5p. Downregulation of let-7c-5p resulted in IFN-γ and IL-2 upregulation in CD8+ T Cells, whereas its upregulation had the opposite effects. Further experiments demonstrated that IL-36β downregulated IFN-γ in let-7c-5p+ CD8+ T cells. Conclusion: These findings suggest IL-36β promotes IFN-γ and IL-2 production in CD8+ T cells, and IL-36β promotes anti-tumor effects in CD8+ T cells by downregulating micro-RNA let-7c-5p.

BackgroudMiR-29a belongs to one of the subtypes of miRNAs known as non-coding single-stranded RNAs, and is preferentially expressed in normal tissues. B7-H3, a member of the B7/CD28 immunoglobulin superfamily, was shown to be overexpressed in several solid malignant tumors, including colon cancer. In addition, it is associated with tumor progression and poor prognosis.MethodsWe used immunohistochemical and western blotting to assess B7-H3 protein expression levels in colon cancer and adjacent normal tissues, and then compared their relationships with clinicopathological factors. Quantitative real time reverse transcription PCR was used to assess B7-H3 and miRNA-29a mRNA expression levels, and then their relationship and clinical significance were evaluated. In addition, colon cancer Caco-2 cells, which constitutively overexpress B7-H3, were transfected with lentivirus particles for miR-29a upregulation. Invasion and migration assays were carried out in vitro along with the establishment of a subcutaneous xenograft model in vivo to determine the role of miRNA-29a in colon cancer progression.ResultsThe B7-H3 protein showed elevated expression in colon carcinoma, and was relevant to TNM staging, lymph node metastasis and reduced survival. Meanwhile, miR-29a was preferentially expressed in normal colon tissues while B7-H3 transcript levels had no marked differences between tumor and normal tissue specimens. In vitro, miR-29a upregulation resulted in reduced B7-H3 expression. Furthermore, miR-29a upregulation reduced the invasive and migratory abilities of colon carcinoma cells. In animal models, upregulation of miR-29a slowed down the growth of subcutaneous xenotransplanted tumors, and resulted in prolonged survival time.ConclusionMiR-29a downregulates B7-H3 expression and accordingly inhibits colon cancer progression, invasion and migration, indicating miR-29a and B7-H3 might represent novel molecular targets for advanced immunotherapy in colon cancer.