IL-9 stimulates an anti-tumor immune response and facilitates immune checkpoint blockade in the CMT167 mouse model.

OBJECTIVES: There is mounting evidence that interleukin-9 (IL-9) is associated with various cancers although its function in lung cancer remains elusive. This study aimed to elucidate the role(s) of IL-9 in lung cancer and the mechanisms involved. MATERIALS AND METHODS: Expression of IL-9 receptor (IL-9R) in two murine lung cancer cell lines: CMT167 and Lewis lung carcinoma (LLC) were assessed and syngeneic murine lung cancer models were established. Tumor growth, intratumoral immune responses and downstream signaling pathways in tumor-bearing mice were analyzed upon IL-9 treatment. Human lung cancer cell lines A549 and H1975 were included for in vitro validation. Synergistic effects and immune responses of IL-9 in combination with anti-PD-1 were studied. RESULTS: IL-9R expression was only detected in CMT167 but not LLC cells. IL-9 suppressed CMT167 tumor growth and enhanced anti-tumor T cell responses, both of which were absent in IL-9R-deficient LLC model and lost upon IL-9R knockdown in CMT167 model. In CMT167 tumors, while IL-9 increased CD4+ and CD8+ T cells and dendritic cells, the cytotoxic T subset was the key driver of IL-9-induced tumor suppression. Consistently, in CMT167 and A549 cells, IL-9/IL-9R signaling promoted MHC class I upregulation. Inhibition of ERK signaling abolished IL-9-mediated MHC class I upregulation in CMT167 cells. IL-9 induced expression of PD-1 and PD-L1 on CD8+ T lymphocytes and CMT167 cells respectively. Combined IL-9 treatment with PD-1 blockade further upregulated tumor-infiltrating CD8+ T cell frequencies and synergistically suppressed tumor growth in CMT167 model. CONCLUSION: IL-9 suppresses tumor growth by promoting tumor-derived MHC class I presentation and enhancing cytotoxic T cell immunity. Expression of IL-9R might be used as a biomarker for identification of potential target population susceptible to IL-9 treatment. Our study proposes IL-9 as a promising therapeutic immunomodulatory agent that can be used in combination with PD-1 blockade in lung cancer.

Disturbance of the Warburg effect by dichloroacetate and niclosamide suppresses the growth of different sub-types of malignant pleural mesothelioma in vitro and in vivo.

Background: Inhalation of asbestos fibers is the most common cause of malignant pleural mesothelioma (MPM). In 2004, the United States Food and Drug Administration approved a combination of cisplatin with pemetrexed to treat unresectable MPM. Nonetheless novel treatment is urgently needed. The objective of this study is to report the combination effect of dichloroacetate (DCA) or niclosamide (Nic) Nic in MPM. Materials and methods: The effect of a combination of DCA and Nic was studied using a panel of MPM cell lines (H28, MSTO-211H, H226, H2052, and H2452). Cell viability was monitored by MTT assay. Glycolysis, oxidative phosphorylation, glucose, glycogen, pyruvate, lactate, citrate, succinate and ATP levels were determined by corresponding ELISA. Apoptosis, mitochondrial transmembrane potential, cell cycle analysis, hydrogen peroxide and superoxide were investigated by flow cytometry. Cell migration and colony formation were investigated by transwell migration and colony formation assays respectively. The in vivo effect was confirmed using 211H and H226 nude mice xenograft models. Results and conclusion: Cell viability was reduced. Disturbance of glycolysis and/or oxidative phosphorylation resulted in downregulation of glycogen, citrate and succinate. DCA and/or Nic increased apoptosis, mitochondrial transmembrane depolarization, G2/M arrest and reactive oxygen species. Moreover, DCA and/or Nic suppressed cell migration and colony formation. Furthermore, a better initial tumor suppressive effect was induced by the DCA/Nic combination compared with either drug alone in both 211H and H226 xenograft models. In H226 xenografts, DCA/Nic increased median survival of mice compared with single treatment. Single drug and/or a combination disturbed the Warburg effect and activated apoptosis, and inhibition of migration and proliferation in vivo. In conclusion, dichloroacetate and/or niclosamide showed a tumor suppressive effect in MPM in vitro and in vivo, partially mediated by disturbance of glycolysis/oxidative phosphorylation, apoptosis, ROS production, G2/M arrest, and suppression of migration and proliferation.

Active lymphangiogenesis is a major risk factor for anastomotic leakage following sphincter-sparing resection of rectal cancer.

OBJECTIVE: Anastomotic leakage is a major complication of rectal surgery and controversy about its risk factors still exists. The aim of present study was to identify risk factors for anastomotic leakage following sphincter-sparing resection of rectal cancer, focusing on the role of tissular lymphatic vessel density (LVD) in tumorous margin and distal clearance margin. METHODS: In a 9-year period, from September 1999 to September 2009, 750 consecutive patients who underwent anterior resection with restoration of the bowel continuity were included. Univariate and multivariate analysis were applied to identify risk factors for anastomotic leakage. RESULTS: The rate of anastomotic leakage was 7.6% (57 of 750 patients). In a multivariate analysis, high LVD in tumorous margin [P=0.0017; odds ratio (OR)=5.93; 95% confidence interval (CI)=2.61-8.514], high LVD in distal clearance margin (P=0.0011; OR=6.05; 95% CI=2.72-10.108) and lower tumor location (P=0.006; OR=4.620; 95% CI=1.76-6.97) were identified as independent factors for anastomotic leakage. A significant LVD correlation was shown by Spearman's rank test between the tumorous and distal clearance margin (r=0.796). CONCLUSIONS: Tissular LVD in tumorous or distal clearance margin and lower tumor location are important risk factors for anastomotic leakage.