IFNg is conventionally recognized as an inflammatory cytokine that plays a central role in antitumor immunity. Although it has been used clinically to treat a variety of malignancies, low levels of IFNg in the tumor microenvironment (TME) increase the risk of tumor metastasis during immunotherapy. Accumulating evidence suggests that IFNg can induce cancer progression, yet the mechanisms underlying the controversial role of IFNg in tumor development remain unclear. Here, we reveal a dose-dependent effect of IFNg in inducing tumor stemness to accelerate cancer progression in patients with a variety of cancer types. Low levels of IFNg endowed cancer stem-like properties via the intercellular adhesion molecule-1 (ICAM1)-PI3K-Akt-Notch1 axis, whereas high levels of IFNg activated the JAK1-STAT1-caspase pathway to induce apoptosis in non-small cell lung cancer (NSCLC). Inhibition of ICAM1 abrogated the stemlike properties of NSCLC cells induced by the low dose of IFNg both in vitro and in vivo. This study unveils the role of low levels of IFNg in conferring tumor stemness and elucidates the distinct signaling pathways activated by IFNg in a dose-dependent manner, thus providing new insights into cancer treatment, particularly for patients with low expression of IFNg in the TME. Significance: These findings reveal the dose-dependent effect of IFNg in inducing tumor stemness and elucidate the distinct molecular mechanisms activated by IFNg in a dosedependent manner.

PurposeTo systematically evaluate the overall efficacy and safety of current anti-PD-1/PD-L1 antibodies for treatment of patients with advanced or refractory cancer.ResultsFifty-one trials including 6,800 patients were included. The overall response rates for melanoma, non-small cell lung cancer (NSCLC), and renal cell carcinoma (RCC) were 29% (95% CI: 1.53−2.41), 21% (95% CI: 17%−25%) and 21% (95% CI: 16%−27%) respectively. While the overall adverse effects rate for melanoma, NSCLC, RCC were 16% (95% CI: 6%−28%), 11% (95% CI: 8%−14%) and 20% (95% CI: 11%−32%) respectively. Tumor PD-L1 expression and patient smoking status might serve as biomarkers to predict response of anti-PD-1/PD-L1 antibody treatment. Compared to tumors with negative PD-L1 expression, tumors with positive PD-L1 expression had a significantly higher clinical response rate (41.4% versus 26.5%) with RR = 1.92 (95% CI: 1.53−2.41, P < 0.001). Smoker patients also showed a significantly higher response rate (33.7%) than patients who never smoked (4.2%) with RR = 6.02 (95% CI: 1.22−29.75, P = 0.028). Nivolumab and Pembrolizumab were associated with significantly increased response rate (RR = 2.89, 95% CI: 2.46−3.40, P < 0.001), reduced death risk (HR= 0.53; 95% CI: 0.48−0.57; P < 0.001), and decreased adverse effect rate (RR = 0.49, 95% CI: 0.30−0.80, P = 0.004) compared with other therapies.Experimental DesignClinical trials reporting response or safety of anti-PD-1/PD-L1 antibodies for advanced or refractory cancer patients published before January 31th 2016 were searched in PubMed and EMBASE database. Meta-analyses using random effects models were used to calculate the overall estimate.ConclusionsAnti-PD-1/PD-L1 antibodies have high response rates and low adverse effect rates for advanced or refractory cancers.

Genetically modified mice with spontaneous development of mammary carcinoma provide a powerful tool to study the efficacy of tumor vaccines, since they mimic breast cancer development in humans. We used a transgenic murine model expressing polyomavirus middle T oncogene and mucin 1 tumor-associated Ag to determine the preventive effect of a dendritic/tumor fusion cell vaccine. The MMT (a transgenic murine model) mice developed mammary carcinoma between the ages of 65–108 days with 100% penetrance. No spontaneous CTL were detected. However, prophylactic vaccination of MMT mice with dendritic/tumor fusion cells induced polyclonal CTL activity against spontaneous mammary carcinoma cells and rendered 57–61% of the mice free of the disease at the end of experiment (180 days). Furthermore, the level of CTL activity was maintained with multiple vaccinations. The antitumor immunity induced by vaccination with dendritic/tumor fusion cells reacted differently to injected tumor cells and autochthonous tumor. Whereas the injected tumor cells were rejected, the autochthonous tumor evaded the attack and was allowed to grow. Collectively these results indicate that prophylactic vaccination with dendritic/tumor fusion cells confers sufficient antitumor immunity to counter the tumorigenesis of potent oncogenic products. The findings in the present study are highly relevant to cancers in humans.

SUMMARYThe tumour-associated antigen mucin 1 (MUC1) is a multifunctional protein involved in protection of mucous membranes, signal transduction, and modulation of the immune system. More than 70% of cancers overexpress MUC1, making MUC1 a potential target for immunotherapy. In the present study, MUC1 transgenic mice were crossed with syngeneic strains that express the polyomavirus middle-T oncogene (PyMT) driven by the mouse mammary tumour virus promoter long-terminal repeat (MMTV-LTR). The resultant breed (MMT mice) developed spontaneous MUC1-expressing mammary carcinomas with 100% penetrance at 8±15 weeks of age. As found in human breast cancer, the mammary carcinoma in MMT mice arose in multiple stages. Immunization with fusions of dendritic cells and MUC1-positive tumour cells (FC/MUC1) induced MUC1-speci®c immune responses that blocked or delayed the development of spontaneous breast carcinomas. In contrast, there was no delay of tumour development in MMT mice immunized with irradiated MC38/MUC1 tumour cells. The ef®cacy of fusion cells was closely correlated with the timing of initial immunization. Immunization with FC/MUC1 initiated in MMT mice at <1, 1±2 and 2±3 months of age rendered 33, 5 and 0% of mice free of tumour, respectively, up to 6 months. Whereas mice immunized in the later stage of tumour development succumbed to their disease, immunization resulted in control of tumour progression and prolongation of life. These results indicate that immunization with FC/MUC1 can generate an anti-MUC1 response that is suf®cient to delay the development of spontaneous mammary carcinomas and control tumour progression in MMT mice.

Folate receptor alpha (αFR) is overexpressed in 90% of ovarian cancers, one of the most lethal gynecologic cancers. Recent studies have suggested that natural killer (NK) cells may be better chimeric antigen receptor (CAR) drivers because of their favorable innate characteristics, such as directly recognizing and killing tumor cells. However, the therapeutic effects of CAR-engineered NK cells targeting αFR in ovarian cancer have not been reported. In this research, 3 generations of anti-αFR CAR were constructed, namely αFR-ζ (first generation), αFR-28ζ (second generation), and αFR-28BBζ (third generation), and were highly expressed on the surface of NK-92 cells by lentivirus gene transfection. Three anti-αFR CAR-engineered NK-92 cells can specifically kill αFR-positive tumor cells in vitro, especially ovarian cancer cells with high αFR expression. Compared with NK-92 cells expressing αFR-ζ or αFR-28ζ, NK-92 cells expressing αFR-28BBζ showed not only higher antigen-specific cytotoxicity and proliferation but also lower antigen-induced apoptosis. Moreover, stronger degranulation and cytokine secretion were detected in NK-92 cells expressing αFR-28BBζ cocultured with αFR-positive tumor cells. Real-time cell analysis and live cell imaging recorded the process of NK-92 cells expressing αFR-28BBζ killing ovarian cancer cells in vitro. Furthermore, NK-92 cells expressing αFR-28BBζ can effectively eliminate cancer cells in a mouse xenograft model of ovarian cancer and significantly prolong the survival of tumor-bearing mice. These results demonstrate that the anti-αFR CARs redirect NK-92 cells with specific antitumor activity, and the third-generation anti-αFR CAR-engineered NK-92 cells display more potent cytotoxicity against αFR-positive ovarian cancer, laying the foundation for future clinical research.

BackgroundPlatinum resistance is a major challenge in the clinical treatment of advanced ovarian cancer (OC). Accumulating evidence shows that the tumor-promotive M2 macrophage is linked to the limiting chemotherapy efficacy of multiple malignancies including OC. Circular RNAs (circRNAs) are a novel class of non-coding RNAs which function as the critical regulator in biological process of cancer. However, their impact on macrophage polarization and chemoresistance of OC remain unclear.MethodsPlatinum-resistant circRNAs were screened using circRNA deep sequencing and validated using in situ hybridization in OC tissues with or without platinum resistance. The role of circITGB6 in inducing cisplatin (CDDP) resistance was evaluated by clone formation, immunofluorescence and annexin V assays in vitro, and by intraperitoneal tumor model in vivo. The mechanism underlying circITGB6-mediated tumor-associated macrophage (TAM) polarization into M2 phenotype was investigated using RNA pull-down, luciferase reporter, electrophoretic mobility shift, RNA binding protein immunoprecipitation (RIP), ELISA and immunofluorescence assays.ResultsWe identified that a novel circRNA, circITGB6, robustly elevated in tumor tissues and serums from patients with OC with platinum resistance, was correlated with poor prognosis. circITGB6 overexpression promoted an M2 macrophage-dependent CDDP resistance in both vivo and vitro. Mechanistic research determined that circITGB6 directly interacted with IGF2BP2 and FGF9 mRNA to form a circITGB6/IGF2BP2/FGF9 RNA–protein ternary complex in the cytoplasm, thereby stabilizing FGF9 mRNA and inducing polarization of TAMs toward M2 phenotype. Importantly, blocking M2 macrophage polarization with an antisense oligonucleotide targeting circITGB6 markedly reversed the circITGB6-induced CDDP resistance of OC in vivo.ConclusionsThis study reveals a novel mechanism for platinum resistance in OC and demonstrates that circITGB6 may serve as a potential prognostic marker and a therapeutic target for patients with OC.

Background High probability of metastasis limited the long-term survival of patients with hepatocellular carcinoma (HCC). Our previous study revealed that Galectin-3 was closely associated with poor prognosis in HCC patients. Methods The effects of Galectin-3 on tumour metastasis were investigated in vitro and in vivo, and the underlying biological and molecular mechanisms involved in this process were evaluated. Results Galectin-3 showed a close correlation with vascular invasion and poor survival in a large-scale study in HCC patients from multiple sets. Galectin-3 was significantly involved in diverse metastasis-related processes in HCC cells, such as angiogenesis and epithelial-to-mesenchymal transition (EMT). Mechanistically, Galectin-3 activated the PI3K-Akt-GSK-3β-β-catenin signalling cascade; the β-catenin/TCF4 transcriptional complex directly targeted IGFBP3 and vimentin to regulate angiogenesis and EMT, respectively. In animal models, Galectin-3 enhanced the tumorigenesis and metastasis of HCC cells via β-catenin signalling. Moreover, molecular deletion of Galectin-3-β-catenin signalling synergistically improved the antitumour effect of sorafenib. Conclusions The Galectin-3-β-catenin-IGFBP3/vimentin signalling cascade was determined as a central mechanism controlling HCC metastasis, providing possible biomarkers for predicating vascular metastasis and sorafenib resistance, as well as potential therapeutic targets for the treatment of HCC patients.

Adjuvant chemotherapy after surgery is the standard treatment modality for stage III and part of stage II or stage IV colorectal cancer (CRC) patients. However, the 5-year overall survival (OS) rate remains unsatisfactory. Thus, developing combination therapies is essential to improve the prognosis of patients with CRC. The present study aimed to determine the effect of a sequential combination of cytokine-induced killer cell (CIK) infusion and chemotherapy for patients with CRC. 122 patients with CRC treated with postoperative adjuvant chemotherapy were retrospectively included in this study. Among them, 62 patients received adjuvant chemotherapy only (control group), while the other 60 patients, with similar demographic and clinical characteristics, received adjuvant chemotherapy and sequential CIK cell immunotherapy (CIK group). Survival analysis showed significantly improved disease free survival (DFS) and OS rates in the CIK group compared with the control group (log-rank test, P = .0024; P = .008, respectively). Univariate and multivariate analyses indicated that sequential CIK cell treatment was an independent prognostic factor for patients' DFS and OS. Subgroup analyses showed that sequential CIK cell treatment significantly improved the DFS and OS of patients with high-risk T4 stage and insufficient chemotherapy duration. In conclusion, these data indicate that sequential adjuvant CIK cell treatment combined with chemotherapy is an effective therapeutic strategy to prevent disease recurrence and prolong survival of patients with CRC, particularly for patients with highrisk T4 stage and insufficient chemotherapy duration.