Immunotherapies based on immune checkpoint blockade (ICB) have significantly improved patient outcomes and offered new approaches to cancer therapy over the past decade. To date, immune checkpoint inhibitors (ICIs) of CTLA-4 and PD-1/PD-L1 represent the main class of immunotherapy. Blockade of CTLA-4 and PD-1/PD-L1 has shown remarkable efficacy in several specific types of cancers, however, a large subset of refractory patients presents poor responsiveness to ICB therapy; and the underlying mechanism remains elusive. Recently, numerous studies have revealed that metabolic reprogramming of tumor cells restrains immune responses by remodeling the tumor microenvironment (TME) with various products of metabolism, and combination therapies involving metabolic inhibitors and ICIs provide new approaches to cancer therapy. Nevertheless, a systematic summary is lacking regarding the manner by which different targetable metabolic pathways regulate immune checkpoints to overcome ICI resistance. Here, we demonstrate the generalized mechanism of targeting cancer metabolism at three crucial immune checkpoints (CTLA-4, PD-1, and PD-L1) to influence ICB therapy and propose potential combined immunotherapeutic strategies co-targeting tumor metabolic pathways and immune checkpoints.
Humans ; Antibodies, Monoclonal/pharmacology* ; B7-H1 Antigen/antagonists & inhibitors* ; CTLA-4 Antigen/antagonists & inhibitors* ; Immune Checkpoint Inhibitors/pharmacology* ; Neoplasms/drug therapy* ; Programmed Cell Death 1 Receptor ; Tumor Microenvironment

Prostate cancer (PCa) has become one of the common malignant diseases in elderly men, and its incidence is increasing year by year. Apart from surgery, radiotherapy and chemotherapy, immunotherapy, as with the programmed death receptor-1 (PD-1) or the programmed death ligand-1 (PD-L1) inhibitor, is a most promising new strategy for the treatment of PCa. PD-1 and PD-L1 inhibitors restore the activity of T cells by blocking the PD-1/PD-L1 signaling pathway in tumor cells, reverse the mechanism of tumor immune escape, recover the immune system and directly kill tumor cells. This review focuses on the current progress in the studies of PD-1 and PD-L1 inhibitors in the treatment of PCa.
B7-H1 Antigen/antagonists & inhibitors* ; Humans ; Immune Checkpoint Inhibitors/therapeutic use* ; Immunotherapy ; Male ; Programmed Cell Death 1 Receptor/antagonists & inhibitors* ; Prostatic Neoplasms/drug therapy* ; Signal Transduction

BACKGROUND: As the efficacy of programmed cell death-1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors combined with chemotherapy in curing breast cancer is still controversial, this meta-analysis compares the efficacy and safety of PD-1/PD-L1 inhibitors combined with chemotherapy and chemotherapy alone in the treatment of breast cancer, which provides guidance for the clinical treatment. METHODS: Relevant studies published as of April 2022 in the various databases including EMBASE, PubMed, and Cochrane Library were selected. Randomized controlled trials (RCTs) in which control patients underwent chemotherapy alone and experimental group patients underwent combination chemotherapy and PD-1/PD-L1 inhibitor treatment were included in this investigation. Investigations without complete information, researches from which information could not be extracted, duplicate articles, animal studies, review articles, and systematic reviews were excluded. STATA 15.1 was employed for all statistical analyses. RESULTS: In total, eight eligible studies were identified, revealing that combination chemotherapy and PD-1/PD-L1 inhibitor treatment was linked to significant increases in progression-free survival (PFS) relative to chemotherapy alone (hazard ratio [HR] = 0.83, 95% confidence interval [CI]: 0.70-0.99, P = 0.032) but not overall survival (HR = 0.92, 95% CI: 0.80-1.06, P = 0.273). Pooled adverse event rates were also increased within the group of combination treatment relative to the chemotherapy group (risk ratio [RR] = 1.08, 95% CI: 1.03-1.14, P = 0.002). Specifically, nausea rates were lesser within the group of combination treatment relative to the group of chemotherapy (RR = 0.48, 95% CI: 0.25-0.92, P = 0.026). Subgroup analyses indicated that the PFS of patients who underwent combination atezolizumab or pembrolizumab and chemotherapy treatment were substantially longer than those of patients who underwent chemotherapy alone (HR = 0.79, 95% CI: 0.69-0.89, P ≤0.001; HR = 0.79, 95% CI: 0.67-0.92, P = 0.002). CONCLUSIONS The pooled results suggest that combination chemotherapy and PD-1/PD-L1 inhibitor treatment approaches help prolong PFS in breast cancer patients, but have no statistically significant effect on overall survival (OS). Additionally, combination therapy can significantly improve complete response rate (CRR) compared with chemotherapy alone. However, combination therapy was associated with greater rates of adverse events.
Humans ; B7-H1 Antigen/antagonists & inhibitors* ; Drug Therapy, Combination ; Immune Checkpoint Inhibitors/therapeutic use* ; Programmed Cell Death 1 Receptor/antagonists & inhibitors* ; Breast Neoplasms/drug therapy*

In recent years, research on immunotherapy has made great progress. Currently, immunotherapy has made significant breakthrough, especially programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) checkpoint inhibitors (e.g, Nivolumab, Pembrolizumab, Atezolizumab, Durvalumab and Avelumab, etc.) have brought clinical benefits to patients with various pathological types of lung cancer, including squamous cell carcinoma, adenocarcinoma and small cell lung cancer. In this paper, the application value and current status of PD-1/PD-L1 checkpoint inhibitors in lung cancer were comprehensively analyzed by reviewing and interpreting representative clinical studies. Based on the results of various large-scale clinical trials results, the indications of immunotherapy in lung cancer have been continuously broadened, and the details of immunotherapy have also been constantly optimized. However, immunotherapy still faces many challenges, such as the selection of immune combination strategies, the exploration of biomarkers, the management of adverse events, the feasibility of application of driver gene mutation population and so on. In this article, we made a systematic review about the latest progress of PD-1/PD-L1 checkpoint inhibitors in lung cancer, in order to provide cutting-edge reference for the clinical workers.
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Animals ; Antineoplastic Agents, Immunological ; therapeutic use ; B7-H1 Antigen ; antagonists & inhibitors ; genetics ; immunology ; Humans ; Immunotherapy ; Lung Neoplasms ; drug therapy ; genetics ; immunology ; Programmed Cell Death 1 Receptor ; antagonists & inhibitors ; genetics ; metabolism

Antibody-based PD-1/PD-L1 blockade therapies have taken center stage in immunotherapies for cancer, with multiple clinical successes. PD-1 signaling plays pivotal roles in tumor-driven T-cell dysfunction. In contrast to prior approaches to generate or boost tumor-specific T-cell responses, antibody-based PD-1/PD-L1 blockade targets tumor-induced T-cell defects and restores pre-existing T-cell function to modulate antitumor immunity. In this review, the fundamental knowledge on the expression regulations and inhibitory functions of PD-1 and the present understanding of antibody-based PD-1/PD-L1 blockade therapies are briefly summarized. We then focus on the recent breakthrough work concerning the structural basis of the PD-1/PD-Ls interaction and how therapeutic antibodies, pembrolizumab targeting PD-1 and avelumab targeting PD-L1, compete with the binding of PD-1/PD-L1 to interrupt the PD-1/PD-L1 interaction. We believe that this structural information will benefit the design and improvement of therapeutic antibodies targeting PD-1 signaling.
Antibodies, Monoclonal ; immunology ; therapeutic use ; Antibodies, Monoclonal, Humanized ; immunology ; therapeutic use ; B7-H1 Antigen ; antagonists & inhibitors ; immunology ; Humans ; Neoplasms ; drug therapy ; immunology ; pathology ; Programmed Cell Death 1 Receptor ; antagonists & inhibitors ; immunology ; Signal Transduction ; drug effects ; immunology ; T-Lymphocytes ; immunology

Programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) checkpoint blockades have dramatically changed the treatment of non-small cell lung cancer (NSCLC). But we still have no definite biomarkers that may predict the efficacy of treatment by PD-1/PD-L1 inhibitors. In the 18th World Conference on Lung Cancer, the biomarkers that may predict the efficacy of treatment by PD-1/PD-L1 inhibitors in patients with lung cancer has been a popular topic, and it has huge potential in the future. In order to enable more patients to get more benefits from treatment, researchers are looking forward to finding the optimum biomarkers. By organizing and summarizing the information about the biomarkers predicting PD-1/PD-L1 in patients with lung cancer, this review mainly focused on the following six aspects to introduce: expression of PD-L1; tumor mutational burden and the ability of mutation repair, malignant tumor driver mutation, biomarker of immunological effect, blood cell account, comprehensive analysis model. We are hoping to help doctors to find the best biomarker, then much more lung cancer patients could obtain antitumor effects in PD-1/PD-L1 inhibitors treatment.
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Antineoplastic Agents ; pharmacology ; therapeutic use ; B7-H1 Antigen ; antagonists & inhibitors ; Biomarkers, Tumor ; metabolism ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; genetics ; metabolism ; Humans ; Lung Neoplasms ; drug therapy ; genetics ; metabolism ; Programmed Cell Death 1 Receptor ; antagonists & inhibitors

Despite impressive survival benefits with immunotherapy in patients with various solid tumors, the full potential of these agents in prostate cancer has yet to be realized. Sipuleucel-T demonstrated a survival benefit in this population, indicating that prostate cancer is an immunoresponsive disease; however, these results have not been matched by other agents. A large trial with ipilimumab in prostate cancer failed to meet its primary objective, and small trials with PD-1/PD-L1 inhibitors did not yield a significant improvement in overall response. However, several late-stage clinical trials are underway with other vaccines in prostate cancer. Reports of clinical benefit with immunotherapies, particularly when used in combination or a select population, have provided the framework to develop sound clinical trials. Understanding immunogenic modulation, antigen spread, biomarkers, and DNA-repair defects will also help mold future strategies. Through rational patient selection and evidence-based combination approaches, patients with prostate cancer may soon derive durable survival benefits with immunotherapies.
Animals ; Antineoplastic Agents, Immunological/therapeutic use* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; B7-H1 Antigen/antagonists & inhibitors* ; Benzamides ; CTLA-4 Antigen/antagonists & inhibitors* ; Cancer Vaccines/therapeutic use* ; Humans ; Immunotherapy ; Ipilimumab/therapeutic use* ; Male ; Nitriles ; Phenylthiohydantoin/analogs & derivatives* ; Programmed Cell Death 1 Receptor/antagonists & inhibitors* ; Prostatic Neoplasms/drug therapy* ; Tissue Extracts/administration & dosage*

The thioredoxin system plays a role in a variety of physiological functions, including cell growth, differentiation, apoptosis, tumorigenesis, and immunity. We previously confirmed that butaselen (BS), a novel thioredoxin reductase inhibitor, can inhibit the growth of various human cancer cell lines, yet the underlying mechanism remains elusive. In this study, we investigated the anti-tumor effect of BS in vivo through regulating the immune system of KM mice. We found that BS inhibits tumor proliferation by promoting the activation of splenic lymphocytes in mice. BS can elevate the percentage of CD₄^-CD₈⁺ T lymphocytes and the secretion of downstream cytokines in mice via down-regulating the expression of programmed death-ligand 1 (PD-L1) on the tumor cells' surface in vivo. Further study in HepG2 and BEL-7402 cells showed that decrease of PD-L1 level after BS treatment was achieved by inhibiting signal transducer and activator of transcription 3 (STAT3) phosphorylation. Taken together, our results suggest that BS has a role in promoting the immune response by reducing PD-L1 expression via the STAT3 pathway, and subsequently suppresses tumorigenesis.
Animals ; Antineoplastic Agents/pharmacology* ; B7-H1 Antigen/antagonists & inhibitors* ; Benzene Derivatives/therapeutic use* ; CD8-Positive T-Lymphocytes/drug effects* ; Hep G2 Cells ; Humans ; Liver Neoplasms/pathology* ; Male ; Mice ; Organoselenium Compounds/therapeutic use* ; STAT3 Transcription Factor/physiology* ; Thioredoxin-Disulfide Reductase/antagonists & inhibitors* ; Tumor Burden/drug effects*