Identification of a small-molecule Tim-3 inhibitor to potentiate T cell-mediated antitumor immunotherapy in preclinical mouse models.

T cell immunoglobulin and mucin-containing molecule 3 (Tim-3), expressed in dysfunctional and exhausted T cells, has been widely acknowledged as a promising immune checkpoint target for tumor immunotherapy. Here, using a strategy combining virtual and functional screening, we identified a compound named ML-T7 that targets the FG-CC' cleft of Tim-3, a highly conserved binding site of phosphatidylserine (PtdSer) and carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). ML-T7 enhanced the survival and antitumor activity of primary CD8+ cytotoxic T lymphocytes (CTLs) and human chimeric antigen receptor (CAR) T cells and reduced their exhaustion in vitro and in vivo. In addition, ML-T7 promoted NK cells' killing activity and DC antigen-presenting capacity, consistent with the reported activity of Tim-3. ML-T7 strengthened DCs' functions through both Tim-3 and Tim-4, which is consistent with the fact that Tim-4 contains a similar FG-CC' loop. Intraperitoneal dosing of ML-T7 showed comparable tumor inhibitory effects to the Tim-3 blocking antibody. ML-T7 reduced syngeneic tumor progression in both wild-type and Tim-3 humanized mice and alleviated the immunosuppressive microenvironment. Furthermore, combined ML-T7 and anti-PD-1 therapy had greater therapeutic efficacy than monotherapy in mice, supporting further development of ML-T7 for tumor immunotherapy. Our study demonstrates a potential small molecule for selectively blocking Tim-3 and warrants further study.

Dysbiotic tumor microbiota associates with head and neck squamous cell carcinoma outcomes.

BACKGROUND: The need for an effective tool to predict prognosis of head and neck squamous cell carcinoma (HNSCC) patients is critical and unmet. Microbiota has recently been found involved in tumor progression and response to immunotherapy. However, the association of microbiota with the prognosis of HNSCC patients remains obscure. This study aims to investigate the association between tumor microbiota and outcomes of HNSCC patients. METHODS: A retrospective study including 129 primary tumors of HNSCC was conducted. Using 16S rRNA sequencing, the profile and the composition of tumor microbiota were measured and their associations with overall survival (OS) and disease free survival (DFS) were examined. RESULTS: We observed a reduced richness and enriched abundances of genera Schlegelella and Methyloversatilis in tumor microbiota of HNSCC patients with poor prognosis. However, a richer tumor microbiota with greater abundances of genera Bacillus, and Lactobacillus and Sphingomonas was characterized in the patients with favorable prognosis.The ratio of these differentially abundant taxa, microbial dysbiosis index (MDI), was significantly associated with OS (hazard ratio [HR], 4.67, 95% confidence interval [CI], 2.51 to 8.69,P < 0.001) and DFS (HR, 2.89; 95% CI, 1.74 to 4.80, P < 0.001) independently of age, tumor size, lymph node metastasis, differentiation and p16 status. The risk score of multivariate Cox regression exhibited an excellent performance for estimating three-year OS (AUC of 0.826). We also found a richer tumor microbiota was correlated with moderate peritumoral inflammatory infiltration. CONCLUSION: These results indicate that tumor microbiota associates with outcomes of HNSCC patients.

Identification and validation of a prognostic signature of autophagy, apoptosis and pyroptosis-related genes for head and neck squamous cell carcinoma: to imply therapeutic choices of HPV negative patients.

Introduction: An effective tool is needed to predict the prognosis of head and neck squamous cell carcinoma (HNSCC). Human papillomavirus (HPV) positive HNSCC patients generally have a favorable survival and a promising responsiveness to radiotherapy, chemoradiotherapy and checkpoint blockades. However, HPV negative patients, the majority of HNSCC patients, have been largely overlooked. Cell death has been involved in the therapeutic resistance of cancers. To this end, we aimed to identify the association of autophagy, apoptosis and pyroptosis-related genes with the prognosis of HNSCC, and construct a prognostic signature to predict the prognosis for HNSCC, especially for HPV negative HNSCC. Methods: Autophagy and apoptosis-related genes were obtained from Gene Set Enrichment Analysis (GSEA) website, and pyroptosis-related genes were obtained from GSEA and Gene Ontology (GO) database. We established the cell death index (CDI) based on RNA sequencing (RNA-seq) data and clinicopathological information from The Cancer Genome Atlas (TCGA) dataset. The prognostic value of CDI was verified by Kaplan-Meier, receiver operating characteristic (ROC) and univariate and multivariate Cox regression analyses in TCGA dataset, and validated with the datasets from Gene Expression Omnibus (GEO) and Qilu Hospital of Shandong University. We further assessed the immune microenvironment of patients with high and low CDI scores. Moreover, the expression of the signature genes in HNSCC cell lines were explored. Results: We found that CDI was an independent prognostic indicator for overall survival (hazard ratio 3.80, 95% confidential interval: 2.70-5.40, P < 0.001). Furthermore, HNSCC patients with high CDI scores obtained increased overall survival post radiation indicating benefits from radiotherapy of this subgroup. On the other hand, HPV negative HNSCC patients with low CDI exhibited increased checkpoint gene expressions, an inflamed tumor microenvironment and an enriched immune response-related functions, suggesting the potential benefits from checkpoint immunotherapies of this subgroup. Moreover, we validated the baseline and induced expressions of above 16 genes in two HPV negative HNSCC cell lines, CAL27 and SCC-15. Discussion: We established a prognostic signature and emphasized its implements in the therapeutic choices of HPV negative HNSCC patients, the majority and the poor outcome population of HNSCC.

Vitamin E succinate exerts anti-tumour effects on human cervical cancer cells via the CD47-SIRPɑ pathway both in vivo and in vitro.

Vitamin E succinate (RRR-a-tocopheryl succinate, VES) acts as a potent agent for cancer therapy and has no toxic and side effects on normal tissue cells. However, the mechanism by which VES mediates the effects are not yet fully understood. Here, we hypothesised that VES mediates antitumour activity on human cervical cancer cells via the CD47-SIRPɑ pathway in vivo and in vitro. Results indicated that the human cervical cancer HeLa cells treated with VES were more efficiently engulfed by THP-1-derived macrophages. In response to VES, the protein expression of CD47 on cell membranes and the mRNA level of CD47 in different human cervical cancer cells significantly decreased. And the level of calreticulin (CRT) mRNA in the VES-treated cells increased. By contrast, CRT protein expression was not altered. miRNA-155, miRNA-133 and miRNA-326 were up-regulated in the VES-treated HeLa cells. Knocking down miRNA-155 and miRNA-133 by RNA interference increased CD47 protein expression in the VES-treated cells. In vivo efficacy was determined in BALB/C nude mice with HeLa xenografts. Results showed that VES reduced tumour growth, increased overall survival and inhibited CD47 in the tumour transcriptionally and translationally. Furthermore, inflammatory factors (TNF-α, IL-12, IFN-γ, IL-2 and IL-10) in the spleen were altered because of VES treatment. Our results suggest that VES-induced antitumour activity is coupled to the CD47-SIRPɑ pathway in human cervical HeLa cancer cells.

Efficient lead ion removal from water by a novel chitosan gel-based sorbent modified with glutamic acid ionic liquid.

Three novel and highly effective AAIL-modified Chitosan (CS) adsorbents are presented. These three new CS-gels were prepared by an innovative synthetic method that uses amino acid ionic liquids (AA-ILs) to cross-link CS with, separately, glutamic acid, aspartic acid and alanine to give novel adsorbents Glu-AA-IL-CS (1), Asp-AA-IL-CS (2) and Ala-AA-IL-CS (3) respectively. The effectively incarcerating host-structures (1) - (3) were characterized by a whole range of techniques including FT-IR, SEM, EDS and XRD. The differences amongst novel adsorbents (1) - (3) with regard to their rate and efficiency of removal of Pb2+ from aqueous solutions are explained in terms of the different electronic, structural and steric features of the three amino acids. The glutamic acid variant (1) is clearly shown to be the best-performing adsorbent by experimental tests and data in combination with infrared spectroscopy. The behaviour of adsorbents (1) follows pseudo-second-order kinetics,and accord best with the Freundlich adsorption isotherm.

Aberrant expression of chemokine receptor CCR4 in human gastric cancer contributes to tumor-induced immunosuppression.

The chemokine receptor CCR4 is preferentially expressed on certain immune cells and some hematological tumor cells, which play pivotal roles in suppression of host immune response. However, the reasons for the upmodulation of CCR4 and its immune functions in solid tumors remain unclear. Herein, we aimed to determine the expression profiles of CCR4 in gastric cancer cells and its role in regulating antitumor immunity. CCR4 expression was assessed in 63 cases of gastric carcinomas by immunohistochemistry. We found cancer cells in lymphocyte-rich carcinomas more frequently showed moderate to strong positive staining for CCR4 than those in conventional carcinomas (P = 0.041), and also found a positive relationship between expression of CCR4 and tumor necrosis factor-α (P = 0.012). Stimulation of gastric cell lines with various cytokines showed that tumor necrosis factor-α uniquely upmodulated CCR4 expression through activation of nuclear factor-κB. Additional coculture experiments showed the forced expression of CCR4 in SGC-7901 cells caused a significant reduction of γ-interferon and elevation of interleukin-10 secretion in the supernatants from cocultured SGC-7901 cells and PBMCs. In addition, granzyme A production in cancer cell-cocultured CD56(+) natural killer cells was significantly downregulated. Inhibition of the overexpressed CCR4 in cancer cells by an inhibitor of CCR4, compound 39, proved to partly restore the antitumor immunity in respect of the inverse changes in those factors. Our studies suggest that the aberrant expression of CCR4 in human gastric cancer could contribute to tumor-induced immunosuppression. Conceivably, downmodulation of CCR4 expression could be a promising immunotherapy for human gastric cancer.