Anti-angiogenesis therapy overcomes the innate resistance to PD-1/PD-L1 blockade in VEGFA-overexpressed mouse tumor models.

The effectual clinical benefits of immune checkpoint inhibitor (ICI) are hampered by a high rate of innate resistance, and VEGFA may contribute to ICI treatment resistance. In this study, we endeavored to assess the tumor microenvironment (TME) in VEGFA-overexpressed human tumors and mouse tumor models, and to explore whether anti-angiogenesis therapy can overcome the innate resistance to ICI in hyperangiogenesis mouse tumor models and the underlying mechanism. Effect of VEGFA on clinical prognosis and TME was analyzed using TCGA data. The VEGFA-overexpressed mouse breast and colon subcutaneous models were established. PD-1 mAb or apatinib alone and combination therapy were used. Immunohistochemistry and immunofluorescence were used to assess angiogenesis and hypoxia. Flow cytometry, RNA sequencing and MCP-counter were applied to detect tumor immunomicroenvironment. High level of VEGFA mRNA in human tumors is related to poor prognosis and hypoxic, angiogenic and immunosuppressive TME. Upregulation of VEGFA increased the degree of malignancy of tumor cells in vitro and in vivo. VEGFA-overexpressed models were characterized by hypoxic, hyperangiogenic and immunosuppressive TME and indicated innate resistance to ICI. In tumor-bearing mice without VEGFA overexpression, the combination therapy had no synergistic anti-tumor effect compared to monotherapy. However, apatinib alleviated hyperangiogenesis and hypoxia in TME and converted the immunosuppressive TME into an immunostimulatory one in VEGFA-overexpressed tumors. Thus, anti-angiogenesis therapy could improve the efficiency of ICI in VEGFA-overexpressed tumors. Revealing whether there is hypervascularization in tumor tissues may help to clarify the adoption of anti-angiogenesis and ICI combination therapy or ICI monotherapy in cancer treatment.

AlloFinder: a strategy for allosteric modulator discovery and allosterome analyses.

Allostery tweaks innumerable biological processes and plays a fundamental role in human disease and drug discovery. Exploration of allostery has thus been regarded as a crucial requirement for research on biological mechanisms and the development of novel therapeutics. Here, based on our previously developed allosteric data and methods, we present an interactive platform called AlloFinder that identifies potential endogenous or exogenous allosteric modulators and their involvement in human allosterome. AlloFinder automatically amalgamates allosteric site identification, allosteric screening and allosteric scoring evaluation of modulator-protein complexes to identify allosteric modulators, followed by allosterome mapping analyses of predicted allosteric sites and modulators in human proteome. This web server exhibits prominent performance in the reemergence of allosteric metabolites and exogenous allosteric modulators in known allosteric proteins. Specifically, AlloFinder enables identification of allosteric metabolites for metabolic enzymes and screening of potential allosteric compounds for disease-related targets. Significantly, the feasibility of AlloFinder to discover allosteric modulators was tested in a real case of signal transduction and activation of transcription 3 (STAT3) and validated by mutagenesis and functional experiments. Collectively, AlloFinder is expected to contribute to exploration of the mechanisms of allosteric regulation between metabolites and metabolic enzymes, and to accelerate allosteric drug discovery. The AlloFinder web server is freely available to all users at http://mdl.shsmu.edu.cn/ALF/.

Pseudoprogression and hyperprogression after checkpoint blockade.

Immune checkpoint inhibitors appear to be one of the most promising immunotherapies with significant clinical benefits and durable responses in multiple tumor types. A heterogeneity of responses appears in patients receiving checkpoint blockade, including pseudoprogression where the tumor burden or number of tumor lesions increases initially before decreasing. Another special response observed after checkpoint blockade is hyperprogression, a phenomenon reflecting a very rapid tumor progression following immunotherapy, suggesting that checkpoint blockade could impact detrimentally on a small subset of patients. As immunotherapeutics, especially anti-PD-1/PD-L1 agents, become more widely available, evaluating the efficacy of these novel drugs poses a major challenge to clinicians, who aim to avoid either premature withdrawal of the treatment or prolonging ineffective treatment. Although the mechanism and recognition of pseudoprogression have gradually come to light, the incidence, basis, identification and predictive biomarkers of hyperprogression have been largely unknown, and this review documents the existing research findings and points out the areas where further studies are badly needed.