Programmed cell death protein-1/programmed cell death ligand-1 pathway inhibition and predictive biomarkers: understanding transforming growth factor-beta role

Harnessing Spatiotemporal-Specific Tumorous Exosome Dynamics: Ultra-Sensitive Lanthanide Luminescence Detection Strategy Enabled by Exosomal Membrane Engineering for Melanoma Immunotherapy Monitoring

Focused on the newly secreted tumorous exosomes during melanoma immunotherapy, this work has pioneered an ultra-sensitive spatiotemporal-specific exosome detection strategy, leveraging advanced exosomal membrane engineering techniques. The proposed strategy harnesses the power of amplified lanthanide luminescence signals on these exosomes, enabling precise and real-time monitoring of the efficacy of melanoma immunotherapy. The methodology comprises two pivotal steps. Initially, Ac4ManNAz-associated metabolic labeling is employed to evolve azide groups onto the membranes of newly secreted exosomes with remarkable selectivity. These azide groups serve as versatile clickable artificial tags, enabling the precise identification of melanoma exosomes emerging during immunotherapy. Subsequently, lanthanide-nanoparticle-functionalized polymer chains are controllably grafted onto the exosome surfaces through click chemistry and in situ Fenton-RAFT polymerization, serving as robust signal amplifiers. When integrated with time-resolved fluorescence detection, this strategy yields detection signals with an exceptionally high signal-to-noise ratio, enabling ultra-sensitive detection of PD-L1 antigen expression levels on the spatiotemporal-specific exosomes. The detection strategy boasts a wide linear concentration range spanning from 1.7 × 104 to 1.7 × 109 particles/mL, with a remarkable theoretical detection limit of 1.28 × 103 particles/mL. The remarkable enhancements in detection sensitivity and accuracy facilitate the evaluation of the efficacy of immunotherapeutic interventions in the mouse B16 melanoma model, notably revealing a substantial disparity in PD-L1 levels between immunotherapy-treated and untreated groups (P < 0.01) and further emphasizing the cumulative therapeutic effect that intensifies with repeated treatments (P < 0.001).

Radiotherapy and immunology

The majority of cancer patients receive radiotherapy during the course of treatment, delivered with curative intent for local tumor control or as part of a multimodality regimen aimed at eliminating distant metastasis. A major focus of research has been DNA damage; however, in the past two decades, emphasis has shifted to the important role the immune system plays in radiotherapy-induced anti-tumor effects. Radiotherapy reprograms the tumor microenvironment, triggering DNA and RNA sensing cascades that activate innate immunity and ultimately enhance adaptive immunity. In opposition, radiotherapy also induces suppression of anti-tumor immunity, including recruitment of regulatory T cells, myeloid-derived suppressor cells, and suppressive macrophages. The balance of pro- and anti-tumor immunity is regulated in part by radiotherapy-induced chemokines and cytokines. Microbiota can also influence radiotherapy outcomes and is under clinical investigation. Blockade of the PD-1/PD-L1 axis and CTLA-4 has been extensively investigated in combination with radiotherapy; we include a review of clinical trials involving inhibition of these immune checkpoints and radiotherapy.

Tumor-associated macrophages in anti-PD-1/PD-L1 immunotherapy for hepatocellular carcinoma: recent research progress

Hepatocellular carcinoma (HCC) is one of the cancers that seriously threaten human health. Immunotherapy serves as the mainstay of treatment for HCC patients by targeting the programmed cell death protein 1/programmed cell death 1 ligand 1 (PD-1/PD-L1) axis. However, the effectiveness of anti-PD-1/PD-L1 treatment is limited when HCC becomes drug-resistant. Tumor-associated macrophages (TAMs) are an important factor in the negative regulation of PD-1 antibody targeted therapy in the tumor microenvironment (TME). Therefore, as an emerging direction in cancer immunotherapy research for the treatment of HCC, it is crucial to elucidate the correlations and mechanisms between TAMs and PD-1/PD-L1-mediated immune tolerance. This paper summarizes the effects of TAMs on the pathogenesis and progression of HCC and their impact on HCC anti-PD-1/PD-L1 immunotherapy, and further explores current potential therapeutic strategies that target TAMs in HCC, including eliminating TAMs in the TME, inhibiting TAMs recruitment to tumors and functionally repolarizing M2-TAMs (tumor-supportive) to M1-TAMs (antitumor type).

Roles of tumor-associated macrophages in anti-PD-1/PD-L1 immunotherapy for solid cancers

In recent years, tumor immunotherapy has made significant progress. However, tumor immunotherapy, particularly immune checkpoint inhibitors (e.g., PD-1/PD-L1 inhibitors), benefits only a tiny proportion of patients in solid cancers. The tumor microenvironment (TME) acts a significant role in tumor immunotherapy. Studies reported that tumor-associated macrophages (TAMs), as one of the main components of TME, seriously affected the therapeutic effect of PD-1/PD-L1 inhibitors. In this review, we analyzed TAMs from epigenetic and single-cell perspectives and introduced the role and mechanisms of TAMs in anti-programmed death protein 1(anti-PD-1) therapy. In addition, we summarized combination regimens that enhance the efficacy of tumor PD-1/PD-L1 inhibitors and elaborated on the role of the TAMs in different solid cancers. Eventually, the clinical value of TAMs by influencing the therapeutic effect of tumor PD-1/PD-L1 inhibitors was discussed. These above are beneficial to elucidate poor therapeutic effect of PD-1/PD-L1 inhibitors in solid tumors from the point of view of TAMs and explore the strategies to improve its objective remission rate of solid cancers.

Downregulation of Programmed Death-1 Pathway Promoting CD8 + T Cell Cytotoxicity in Primary Biliary Cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is an autoimmune disease. CD8 + T cell (CTLs) cytotoxicity played a crucial rule in of PBC with unclear detailed pathogenesis.

AIMS

The role of the programmed death-1 (PD-1) pathway in CD8 + T cell cytotoxicity in patients with PBC was determined.

METHODS

We recruited 69 patients with PBC and 57 healthy controls (HCs). PD-1 pathway in peripheral CD8 + T cells and related cytokines were detected, and gene expression levels were detected. Immunofluorescence staining of PD-1/PD-L1 was performed on liver tissue. PD-1 ± CTLs were cocultured with human intrahepatic biliary epithelial cells (HiBECs) to measure CTL cytotoxicity, proliferation and cytokine levels and HiBEC apoptosis. The upstream signaling pathway of PD-1 was detected.

RESULTS

PBC patients exhibited Tbet gene upregulation and PD-1 downregulation in CTLs, with PD-1 expression reduced in CTLs and PD-L1 reduced in the liver portal region relative to HCs. Higher plasma IL-10, interferon-γ and transforming growth factor-β concentrations were observed in the PBC group than the HC group. In CTL and HiBEC coculture experiment, compared with PD-1- CTLs, PD-1 + CTLs exhibited weaker cytotoxicity, less proliferation and lower cytokine production. When the system was blocked by anti-PD-1 antibodies, these effects were antagonized.

CONCLUSIONS

PD-1 expression in CD8 + T cells decreased, and PD-1 pathway-related cytokines changed in patients with PBC. PD-1/PD-L1 pathway silencing increased CD8 + T cell proliferation, related cytokine production and CTL cytotoxic effects on HiBECs in coculture experiment. The PD-1/PD-L1 pathway might represent an important pathway in the immunological mechanism underlying PBC.

Integrated Analysis of Transcriptomic and Genomic Data Reveals Blood Biomarkers With Diagnostic and Prognostic Potential in Non-small Cell Lung Cancer

Background: Lung cancer is the second most common cancer and the main leading cause of cancer-associated death worldwide. Non-small cell lung cancer (NSCLC) accounts for about 85% of lung cancer diagnoses and more than 50% of all lung cancer cases are diagnosed at an advanced stage; hence have poor prognosis. Therefore, it is important to diagnose NSCLC patients reliably and as early as possible in order to reduce the risk of mortality.

Methods: We identified blood-based gene markers for early NSCLC by performing a multi-omics approach utilizing integrated analysis of global gene expression and copy number alterations of NSCLC patients using array-based techniques. We also validated the diagnostic and the prognostic potential of the gene signature using independent datasets with detailed clinical information.

Results: We identified 12 genes that are significantly expressed in NSCLC patients’ blood, at the earliest stages of the disease, and associated with a poor disease outcome. We then validated 12-gene signature’s diagnostic and prognostic value using independent datasets of gene expression profiling of over 1000 NSCLC patients. Indeed, 12-gene signature predicted disease outcome independently of other clinical factors in multivariate regression analysis (HR = 2.64, 95% CI = 1.72–4.07; p = 1.3 × 10−8). Significantly altered functions, pathways, and gene networks revealed alterations in several key genes and cancer-related pathways that may have importance for NSCLC transformation, including FAM83A, ZNF696, UBE2C, RECK, TIMM50, GEMIN7, and XPO5.

Conclusion: Our findings suggest that integrated genomic and network analyses may provide a reliable approach to identify genes that are associated with NSCLC, and lead to improved diagnosis detecting the disease in early stages in patients’ blood instead of using invasive techniques and also have prognostic potential for discriminating high-risk patients from the low-risk ones.

AMPK promotes antitumor immunity by downregulating PD-1 in regulatory T cells via the HMGCR/p38 signaling pathway

Background

AMP-activated protein kinase (AMPK) is a metabolic sensor that maintains energy homeostasis. AMPK functions as a tumor suppressor in different cancers; however, its role in regulating antitumor immunity, particularly the function of regulatory T cells (Tregs), is poorly defined.

Methods

AMPKα1^fl/flFoxp3^YFP-Cre, Foxp3^YFP-Cre, Rag1^−/−, and C57BL/6 J mice were used for our research. Flow cytometry and cell sorting, western blotting, immuno-precipitation, immuno-fluorescence, glycolysis assay, and qRT-PCR were used to investigate the role of AMPK in suppressing programmed cell death 1 (PD-1) expression and for mechanistic investigation.

Results

The deletion of the AMPKα1 subunit in Tregs accelerates tumor growth by increasing the expression of PD-1. Metabolically, loss of AMPK in Tregs promotes glycolysis and the expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), a key enzyme of the mevalonate pathway. Mechanistically, AMPK activates the p38 mitogen-activated protein kinase (MAPK) that phosphorylates glycogen synthase kinase-3β (GSK-3β), inhibiting the expression of PD-1 in Tregs.

Conclusion

Our study identified an AMPK regulatory mechanism of PD-1 expression via the HMGCR/p38 MAPK/GSK3β signaling pathway. We propose that the AMPK activator can display synergic antitumor effect in murine tumor models, supporting their potential clinical use when combined with anti-PD-1 antibody, anti-CTLA-4 antibody, or a HMGCR inhibitor.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01420-9.

CU06-1004-Induced Vascular Normalization Improves Immunotherapy by Modulating Tumor Microenvironment via Cytotoxic T Cells

Blocking the immune evasion mechanism of tumor cells has become an attractive means for treating cancers. However, the usage of a drug such as nivolumab (αPD-1), which blocks programmed cell death protein 1 (PD-1), turned out to be only effective against certain types of cancer. Especially, vascular abnormal structures of which deter delivery route by leakage and cause the poor perfusion were considered to be environment unfavorable to T cells and immune checkpoint blockade (ICB) delivery within the tumor microenvironment (TME). Herein, we report stabilization of tumor blood vessels by endothelial dysfunctional blocker CU06-1004, which modified the TME and showed synergistic effects with immunotherapy anti-PD-1 antibody. CU06-1004 combination therapy consistently prolonged the survival of tumor-bearing mice by decreasing tumor growth. T-cell infiltration increased in the tumors of the combination group, with cytotoxic CD8+ T cell activity within the tumor parenchyma upregulated compared with anti-PD-1 monotherapy. Tumor inhibition was associated with reduced hypoxia and reduced vessel density in the central region of the tumor. These effects correlated significantly with enhanced expression of IFN gamma and PD-L1 in tumors. Taken together, our findings suggest that CU06-1004 is a potential candidate drug capable of improving therapeutic efficacy of anti-PD-1 through beneficial changes in the TME.

Recent Advances in the Development of TGF-β Signaling Inhibitors for Anticancer Therapy

TGF-β is a multifunctional cytokine that plays an important role in both physiologic and pathologic processes, including cancer. Importantly, TGF-β has a dual role in tumorigenesis, acting as a tumor suppressor or a tumor promoter, depending on the stage of tumor development. The aberrantly upregulated production of TGF-β has been strongly implicated in tumor progression, angiogenesis, and metastasis, as well as immune evasion. Therefore, hyperactivated TGF-β signaling is considered a potential therapeutic target for cancer therapy. Numerous inhibitors of overactivated TGF-β signaling have been developed, and some of them are currently in clinical trials. This review focuses on the TGF-β signaling that contributes to tumor progression and immune evasion in the tumor microenvironment and presents recent achievements on TGF-β signaling inhibition as a single or combined therapeutic approach in cancer therapy.

Repositioning of Immunomodulators: A Ray of Hope for Alzheimer's Disease?

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder characterized by cognitive decline and by the presence of amyloid β plaques and neurofibrillary tangles in the brain. Despite recent advances in understanding its pathophysiological mechanisms, to date, there are no disease-modifying therapeutic options, to slow or halt the evolution of neurodegenerative processes in AD. Current pharmacological treatments only transiently mitigate the severity of symptoms, with modest or null overall improvement. Emerging evidence supports the concept that AD is affected by the impaired ability of the immune system to restrain the brain's pathology. Deep understanding of the relationship between the nervous and the immune system may provide a novel arena to develop effective and safe drugs for AD treatment. Considering the crucial role of inflammatory/immune pathways in AD, here we discuss the current status of the immuno-oncological, immunomodulatory and anti-TNF-α drugs which are being used in preclinical studies or in ongoing clinical trials by means of the drug-repositioning approach.

Metastatic sites as predictors in advanced NSCLC treated with PD-1 inhibitors: a systematic review and meta-analysis

BACKGROUND

Programmed cell death protein 1 (PD-1) inhibitors are the first-line treatment for advanced non-small-cell lung cancer (NSCLC) patients. However, their efficacy in metastatic NSCLC patients remains controversial.

AIM OF THE STUDY

The aim of our study was to evaluate the prognosis of advanced metastatic NSCLC patients treated with PD-1 inhibitors, and discuss the predictive effect of metastatic site on the long-term outcome.

METHODS

The Embase, Ovid Medline, Cochrane Central Register of Controlled Trials, and PubMed databases were systematically screened up to February 10, 2020. Twenty-five eligible studies, involving 8,067 patients that assessed the impact of metastatic sites on survival outcome were incorporated in our study. Overall survival (OS) and progression-free survival (PFS) were described as hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

Among the advanced NSCLC patients, the median proportion of brain, liver, bone, and adrenal gland metastases were 21%, 17%, 35%, and 21%, respectively. Patients with metastases to the brain, liver, and bone had worse OS compared to patients without these metastases when treated with PD-1 inhibitors. Similarly, patients with metastasis to the brain and liver were more likely to progress when treated with PD-1 inhibitors. Besides, patients with multiple metastatic sites had worse PFS compared to patients with one metastatic site, while no significant difference was found in terms of OS.

CONCLUSIONS

Based on the findings of our systematic review and meta-analysis, metastatic sites were independent predictors of the survival outcome for advanced NSCLC patients treated with PD-1 inhibitors.

Oxaliplatin induces immunogenic cell death in hepatocellular carcinoma cells and synergizes with immune checkpoint blockade therapy

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common and devastating malignancies. Oxaliplatin, a platinum-based chemotherapeutic agent, is approved for the treatment of several malignancies, including HCC. However, its role in HCC is not well established. This study was designed to investigate the potential of oxaliplatin as an immunogenic cell death (ICD) inducer and to explore its regulatory effects on the response of HCC to immune checkpoint blockade therapy.

METHODS

Murine and human HCC cells were treated with oxaliplatin, followed by evaluation of the expression of ICD-related biomarkers. Murine HCC cells (H22) were subcutaneously inoculated into mice to establish a syngeneic tumor graft model, after which tumor sizes and in vivo immune cell activation were evaluated. To assess putative synergistic effects of oxaliplatin with anti-PD-1 antibodies on H22 tumors, tumor parameters and secreted cytokines were quantified.

RESULTS

ICD-related biomarkers were found to be enhanced after treatment of human and murine HCC cells with oxaliplatin. Additionally, we found that the number of mature dendritic cells (DCs) was increased after immature DCs were cocultured with oxaliplatin-treated H22 cells. The numbers of CD8⁺ T cells and mature DCs were found to be increased in vivo whereas, in contrast, the number of Treg cells was decreased. The tumor sizes were smaller in the oxaliplatin group than in the control group. In the syngeneic tumor graft model, we found that combination therapy with oxaliplatin and anti-PD-1 antibodies could achieve better outcomes than monotherapy, as indicated by (i) inhibition of tumor growth and TGF-β secretion and (ii) augmentation of inflammatory cytokine secretion.

CONCLUSIONS

Our data indicate that oxaliplatin can be used as an inducer of ICD and as a modulator of the tumor immune microenvironment. Combination therapies composed of oxaliplatin and immune checkpoint inhibitors may open up novel avenues for the treatment of HCC.

Silence of Hippo Pathway Associates with Pro-Tumoral Immunosuppression: Potential Therapeutic Target of Glioblastomas

The critical role of the Hippo pathway has been recently investigated in various cancers, but little is known about its role in glioblastoma (GBM). In order to evaluate the clinical relevance of the Hippo pathway in GBM, we generated a core gene expression signature from four different previously-established silence of Hippo pathway (SOH) signatures. Based on a newly generated core SOH signature, a SOH and active Hippo pathway (AH) was predicted in GBM samples from The Cancer Genome Atlas (TCGA) and validated in a separate cohort. A comparative analysis was performed on multi-panel genomic datasets from TCGA and the possible association of SOH with immune activity and epithelial mesenchymal transition was also evaluated. The SOH signature was associated with poor prognosis in GBM in both cohorts. Expression levels of CTGF and CYR61, the most reliable and well-known downstream targets of YAP1, were markedly increased in the SOH subgroup of GBM patients. SOH signature was strongly associated with a high immune signature score and mesenchymal features. Genes differentially expressed between SOH and AH groups revealed many markers for inhibitory immune checkpoints and M2-polarized macrophages were upregulated in the SOH subgroup, suggesting that SOH may induce the resistance of cancer cells to host immune response in GBM. In summary, SOH is significantly associated with the poor prognosis of GBM patients and is possibly mediated by pro-tumoral immunosuppression.

Correction of immunosuppression in aged septic rats by human ghrelin and growth hormone through the vagus nerve-dependent inhibition of TGF-β production

BACKGROUND

Co-administration of human ghrelin and growth hormone (GH) reverse immunosuppression in septic aged animals, but the mechanism remains elusive. Here, we hypothesize that ghrelin and GH co-treatment restores the immune response in aged septic rats by inhibiting the production of transforming growth factor-β (TGF-β), an immunoregulatory cytokine, through the vagus nerve.

METHODS

Male aged Fischer rats (22-23-month-old) were made septic by cecal ligation and puncture (CLP) with or without dissecting the vagus nerve (vagotomy). Human ghrelin and GH or vehicle (PBS) were administrated subcutaneously at 5 h post CLP. After 20 h of CLP, serum and spleens were harvested.

RESULTS

Serum TGF-β levels were increased in septic aged rats, while ghrelin and GH treatment significantly reduced its levels. Expression of TGF-β in the spleen was upregulated after sepsis, while ghrelin and GH treatment significantly inhibited its expression. TNF-α and IL-6 levels were significantly reduced after ex vivo LPS stimulation of splenocytes from rats that underwent CLP compared to sham rats; while these levels were significantly higher in splenocytes from ghrelin and GH-treated CLP rats compared to vehicle-treated CLP rats. Ghrelin and GH treatment reduced program death receptor-1 (PD-1) expression, increased human leukocyte antigen-DR (HLA-DR) expression, attenuated lymphopenia, and cleaved caspase-3 levels in the spleen of septic aged rats. Vagotomy diminished the beneficial effects of ghrelin and GH treatment in septic rats. In vitro, the addition of ghrelin, GH, or ghrelin and GH together had no effect on restoring immune response in splenocytes from CLP rats following LPS stimulation, indicating the requirement of the vagus nerve for ghrelin and GH's effect.

CONCLUSIONS

Ghrelin and GH attenuate immunosuppression in aged septic rats through the vagus nerve-dependent inhibition of TGF-β production.

MiRNAs and LncRNAs: Dual Roles in TGF-β Signaling-Regulated Metastasis in Lung Cancer

Lung cancer is one of the most malignant cancers around the world, with high morbidity and mortality. Metastasis is the leading cause of lung cancer deaths and treatment failure. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs), two groups of small non-coding RNAs (nc-RNAs), are confirmed to be lung cancer oncogenes or suppressors. Transforming growth factor-β (TGF-β) critically regulates lung cancer metastasis. In this review, we summarize the dual roles of miRNAs and lncRNAs in TGF-β signaling-regulated lung cancer epithelial-mesenchymal transition (EMT), invasion, migration, stemness, and metastasis. In addition, lncRNAs, competing endogenous RNAs (ceRNAs), and circular RNAs (circRNAs) can act as miRNA sponges to suppress miRNAs, thereby mediating TGF-β signaling-regulated lung cancer invasion, migration, and metastasis. Through this review, we hope to cast light on the regulatory mechanisms of miRNAs and lncRNAs in TGF-β signaling-regulated lung cancer metastasis and provide new insights for lung cancer treatment.

The Complex Interaction between the Tumor Micro-Environment and Immune Checkpoints in Breast Cancer

The progression of breast cancer and its association with clinical outcome and treatment remain largely unexplored. Accumulating data has highlighted the interaction between cells of the immune system and the tumor microenvironment in cancer progression, and although studies have identified multiple facets of cancer progression within the development of the tumor microenvironment (TME) and its constituents, there is lack of research into the associations between breast cancer subtype and staging. Current literature has provided insight into the cells and pathways associated with breast cancer progression through expression analysis. However, there is lack of co-expression studies between immune pathways and cells of the TME that form pro-tumorigenic relationships contributing to immune-evasion. We focus on the immune checkpoint and TME elements that influence cancer progression, particularly studies in molecular subtypes of breast cancer.

In Vitro Assessment of Putative PD-1/PD-L1 Inhibitors: Suggestions of an Alternative Mode of Action

The programmed cell death protein 1 (PD-1) signaling axis is among the most important therapeutic targets in modern oncology. Aurigene Discovery Technologies Ltd. (Aurigene) has patented a series of peptidomimetic small molecules derived from the PD-1 protein sequence for use in targeting the interaction between PD-1 and its ligand, PD-L1. We evaluated three of Aurigene's most potent compounds in SPR binding assays. Our results showed that these compounds-each of which is known to be potently effective in a splenocyte recovery assay-do not directly inhibit the PD-1/PD-L1 interaction nor do they appear to bind to either of the constituent proteins, indicating that another mechanism is at play. As a result of these studies and upon consideration of structural features within the PD-1/PD-L1 complex, we hypothesize that the Aurigene molecules may interact with a currently unknown protein capable of regulating the PD-1 axis.

Multiplex assay for multiomics advances in personalized-precision medicine

Building the future of precision medicine is the main focus in cancer domain. Clinical trials are moving toward an array of studies that are more adapted to precision medicine. In this domain, there is an enhanced need for biomarkers, monitoring devices, and data-analysis methods. Omics profiling using whole genome, epigenome, transcriptome, proteome, and metabolome can offer detailed information of the human body in an integrative manner. Omes profiles reflect more accurately real-time physiological status. Personalized omics analyses both disease as a whole and the main disease processes, for a better understanding of the individualized health. Through this, multi-omic approaches for health monitoring, preventative medicine, and personalized treatment can be targeted simultaneously and can lead clinicians to have a comprehensive view on the diseasome.

Membrane PD-L1 expression and soluble PD-L1 plasma levels in idiopathic pulmonary fibrosis-a pilot study

Background

Idiopathic pulmonary fibrosis (IPF) has common risk factors with cancer and significant similarities in the pathobiology process, both diseases having poor outcomes. Immune checkpoint PD-L1 has become the target of checkpoint inhibitory therapy that unleashes antitumor T cells and has revolutionized cancer treatment. This is a pilot study exploring membrane immune checkpoint PD-L1 expression in human IPF lung tissue samples and its soluble form, soluble PD-L1 (sPD-L1) plasma concentrations in IPF patients, in order to investigate potential role of PD-L1 as an IPF biomarker.

Methods

Twelve human IPF lung tissue samples (formalin-fixed, paraffin-embedded) obtained by surgical biopsy, have been tested for PD-L1 expression by PD-L1 IHC 22C3 pharmDx assay, while plasma samples for examination of sPD-L1 forms, PD-L1 (B7-H1/CD274) blood concentration, originated from 23 patients with IPF who did not undergo surgical biopsy.

Results

Membrane PD-L1 expression in IPF lung tissue samples was positive to overexpression of PD-L1 in 9 samples out of 12. Only very few cells in the interstitium have shown a discrete PD-L1 expression, but not of a membrane type. As for sPD-L1 forms, we have found elevated concentrations of sPD-L1 in the serum of IPF patients 314.3 ng/L (117.7-483.1 ng/L), significantly higher compared with healthy control group 91.0 ng/L (52.4-119.7 ng/L), P<0.01.

Conclusions

For IPF with PD-L1 expression on alveolar macrophages, further studies are necessary to elucidate this phenomenon. Serum sPD-1/PD-L1 is easily detected in clinical practice and should be further evaluated as a potential prognostic or/and predictive biomarker in IPF.

Immunotherapy combined with epidermal growth factor receptor-tyrosine kinase inhibitors in non-small-cell lung cancer treatment

In recent years, targeted therapy and immunotherapy have played important roles in the treatment of patients with non-small-cell lung cancer (NSCLC). Drugs that target epidermal growth factor receptor (EGFR) mutations (eg, gefitinib, erlotinib, icotinib, and osimertinib) are among the most commonly used targeted therapies. Afatinib is an irreversible second-generation EGFR-tyrosine kinase inhibitor (EGFR-TKI), and the LUX-Lung 3 trial demonstrated the superiority of afatinib to cisplatin and pemetrexed in the frontline treatment of treatment-naïve patients with advanced EGFR mutation adenocarcinoma of the lung. Although these drugs show significant therapeutic efficacy, most patients invariably experience disease progression resulting in death. Immunotherapy targeting programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) has now been approved for the first-line treatment of patients with advanced NSCLC. These can produce sustained clinical responses by reversing negative regulators of T-cell function; however, immunotherapy response rates remain low, and only a few patients ultimately benefit from this approach. Here, we discuss the potential of EGFR-TKIs for inducing antitumor immunity and the feasibility of their combination with immunotherapy (including PD-1/PD-L1 inhibitors) in NSCLC patients and the associated challenges for clinical application.

Are ovarian cancer stem cells the target for innovative immunotherapy?

Cancer stem cells (CSCs), a subpopulation of cancer cells with the ability of self-renewal and differentiation, are believed to be responsible for tumor generation, progression, metastasis, and relapse. Ovarian cancer, the most malignant gynecological cancer, has consistent pathology behavior with CSC model, which suggests that therapies based on ovarian cancer stem cells (OCSCs) can gain a more successful prognosis. Much evidence has proved that epigenetic mechanism played an important role in tumor formation and sustainment. Since CSCs are generally resistant to conventional therapies (chemotherapy and radiotherapy), immunotherapy is a more effective method that has been implemented in the clinic. Chimeric antigen receptor (CAR)-T cell, an adoptive cellular immunotherapy, which results in apparent elimination of tumor in both hematologic and solid cancers, could be used for ovarian cancer. This review covers the basic conception of CSCs and OCSCs, the implication of epigenetic mechanism underlying cancer evolution considering CSC model, the immunotherapies reported for ovarian cancer targeting OCSCs currently, and the relationship between immune system and hierarchy cancer organized by CSCs. Particularly, the promising prospects and potential pitfalls of targeting OCSC surface markers to design CAR-T cellular immunotherapy are discussed here.

PD-1/PD-L1 immune checkpoint inhibitors in advanced cervical cancer

Programmed cell death-1 and programmed cell death ligand-1 (PD-1/PD-L1) blockage has become an important treatment modality after approval of pembrolizumab and nivolumab by Food and Drug Administration in advanced cancers. Patients with metastatic and recurrent cervical cancer have limited treatment options and usually receive palliative platinum-based chemotherapy without significant survival benefit. Recent studies provided support for usage of immune checkpoint inhibitors in advanced cervical cancer. Around 35% of cervical squamous cell carcinoma (C-SCC) and 17% of adenocarcinomas expressed PD-L1. Human Papilloma Virus status was also correlated with PD-L1 expression. PD-1/PD-L1 expression in tumor infiltrating inflammatory cells was higher in cervical cancer in comparison to endometrial and ovarian adenocarcinomas. In C-SCC diffuse PD-L1 expression as compared to marginal PD-L1 expression on the interface between tumor and stroma was a risk factor for poor disease-free and disease-specific survival rates. Higher numbers of infiltrating regulatory T cells in PD-L1 positive tumors was associated with better prognosis. The studies performed on other cancer types revealed PD-L1 tumor heterogeneity and transient marker expression. Drug-resistance to immune checkpoint inhibitors is also a potential problem. Currently Phase I/II clinical trials evaluating effects of PD-1 therapy are in progress for cervical carcinoma. Additional studies are required to develop novel biomarkers and for standard evaluation of PD-L1 testing in order to predict response to immune checkpoint inhibitors in all cancer types including cervical carcinoma.

Immune Dysregulation in Cancer Patients Undergoing Immune Checkpoint Inhibitor Treatment and Potential Predictive Strategies for Future Clinical Practice

Realization of the full potential of immune checkpoint inhibitor-targeted onco-immunotherapy is largely dependent on overcoming the obstacles presented by the resistance of some cancers, as well as on reducing the high frequency of immune-related adverse events (IRAEs) associated with this type of immunotherapy. With the exception of combining therapeutic monoclonal antibodies, which target different types of immune checkpoint inhibitory molecules, progress in respect of improving therapeutic efficacy has been somewhat limited to date. Likewise, the identification of strategies to predict and monitor the development of IRAEs has also met with limited success due, at least in part, to lack of insight into mechanisms of immunopathogenesis. Accordingly, considerable effort is currently being devoted to the identification and evaluation of strategies which address both of these concerns and it is these issues which represent the major focus of the current review, particularly those which may be predictive of development of IRAEs. Following an introductory section, this review briefly covers those immune checkpoint inhibitors currently approved for clinical application, as well as more recently identified immune checkpoint inhibitory molecules, which may serve as future therapeutic targets. The remaining and more extensive sections represent overviews of: (i) putative strategies which may improve the therapeutic efficacy of immune checkpoint inhibitors; (ii) recent insights into the immunopathogenesis of IRAEs, most prominently enterocolitis; and (iii) strategies, mostly unexplored, which may be predictive of development of IRAEs.

Combination of immunotherapy with targeted therapies in advanced non-small cell lung cancer (NSCLC)

Treatment for advanced non-small cell lung cancer (NSCLC) has been significantly improved in recent years with the incorporation of drugs targeting antiangiogenesis and more specifically genomic alterations such as the EGFR mutations and ALK translocations. However, most patients invariably progress and die. The emergence of immune checkpoint inhibitors targeting the pathways involved in tumor-induced immunosuppression have redefined the management of the disease, achieving significant long-lasting responses with manageable safety profiles, regardless of histology. Still, response rates with immunotherapy are deemed suboptimal. Current efforts are focusing on new potential combination strategies with synergistic antitumor activity, using immune checkpoint blockade as a partner for targeted agents. Herein we discuss the available data on the combined use of immunotherapy, including PD-1/PD-L1 and CTLA-4 inhibitors, with EGFR and ALK inhibitors and comment on the current status of immunotherapy plus antiangiogenic drugs for molecularly unselected advanced NSCLC.

Predictive factors of response to immunotherapy-a review from the Spanish Melanoma Group (GEM)

Immunotherapy has become a key element in the treatment of several tumors, such as lung carcinoma and melanoma. Immunotherapy, unlike classical chemotherapy and targeted drugs, may yield long-term survival, even in patients who stop treatment due to toxicity. This fact has generated considerable excitement and a real shift in the paradigm of cancer treatment. However, only a small subset of patients benefit from immunotherapy. Survival curves show that most patients have progression of the disease in the first months after starting immunotherapy, followed by a slower decrease over the first 3 years, until curves reach a plateau. This early progression suggests the presence of mechanisms for primary resistance. In addition, some patients have tumor relapse after years of response, suggesting that there is also acquired resistance in a small subset of patients. Resistance mechanisms are now being elucidated. PD-L1 expression in tumor and immune cells correlates with higher chances of response, but melanoma patients with PD-L1 negative tumors can also respond. Several studies have demonstrated an increased probability of clinical benefit when tumors are infiltrated by CD8 T cells, have a high mutation burden or have an interferon gamma signature. But none of these factors has been implemented in the clinical practice, since more studies confirming their value are needed, as well as the development of standardized techniques.

Integrated analysis of differential expression and alternative splicing of non-small cell lung cancer based on RNA sequencing

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, with high morbidity and mortality rates. Numerous diagnosis and treatment methods have been proposed, and the prognosis of NSCLC has improved to a certain extent. However, the mechanisms of NSCLC remain largely unknown, and additional studies are required. In the present study, the RNA sequencing dataset of NSCLC was downloaded from the Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/). The clean reads obtained from the raw data were mapped to the University of California Santa Cruz human genome (hg19), based on TopHat, and were assembled into transcripts via Cufflink. The differential expression (DE) and differential alternative splicing (DAS) genes were screened out through Cuffdiff and rMATS, respectively. The significantly enriched gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes pathways were obtained through the Database of Annotation, Visualization and Integrated Discovery (DAVID). Different numbers of DE and DAS genes were identified in different types of NSCLC samples, but a number of common functions and pathways were obtained, including biological processes associated with abnormal immune and cell activity. GO terms and pathways associated with substance metabolism, including the insulin signaling pathway and oxidative phosphorylation, were enriched in DAS genes rather than DE genes. Integrated analysis of differential expression and alternative splicing may be helpful in understanding the mechanisms of NSCLC, in addition to its early diagnosis and treatment.

Therapeutic effect of human ghrelin and growth hormone: Attenuation of immunosuppression in septic aged rats

Sepsis is a leading cause of mortality in intensive care units, and is more common in the geriatric population. The control of hyperinflammation has been suggested as a therapeutic approach in sepsis, but to date clinical trials utilizing this strategy have not lead to an effective treatment. In addition to hyperinflammation, patients with sepsis often experience a state of immunosuppression, which serves as an important determinant for increased morbidity and mortality. We previously used aged animals to demonstrate the effectiveness of combined treatment with human ghrelin (Ghr) and human growth hormone (GH) in improving organ injury and survival in septic animals. Here, we hypothesized that combined treatment with Ghr and GH could improve immune function in septic aged animals. Male 24-month-old rats were subjected to cecal ligation and puncture (CLP) for sepsis induction. Human Ghr (80nmol/kg BW) plus GH (50μg/kg BW) or vehicle (normal saline) was administrated subcutaneously at 5h after CLP. The ex vivo production of TNF-α, IL-6 and IL-10 to LPS-stimulation, as well as TNF-α, IL-6, IL-10 and IFN-γ production to anti-CD3/anti-CD28 antibody-stimulation, in splenocytes isolated 20h after CLP, was significantly decreased compared to production of these cytokines in splenocytes from sham animals. The production of cytokines from splenocytes isolated from septic animals that received the combined treatment, however, was significantly higher than from those isolated from vehicle-treated septic animals. Combined treatment prevented the loss of splenic CD4⁺ and CD8⁺ T cells in septic aged rats, and reduced lymphocyte apoptosis. Combined treatment also inhibited an increase in the regulatory T cell (T_reg) population and expression of the immune co-inhibitory molecule PD-1 in the spleens of septic aged rats. In contrast, expression of HLA-DR was increased after combined treatment with Ghr and GH. Based on these findings, we conclude that co-administration of Ghr and GH is a promising therapeutic tool for reversing immunosuppression caused by sepsis in the geriatric population. This article is part of a Special Issue entitled: Immune and Metabolic Alterations in Trauma and Sepsis edited by Dr. Raghavan Raju.

Immune checkpoint and inflammation as therapeutic targets in pancreatic carcinoma

Pancreatic adenocarcinoma (PAC) is one of the most deadly malignant neoplasms, and the efficacy of conventional cytotoxic chemotherapy is far from satisfactory. Recent research studies have revealed that immunosuppression and inflammation are associated with oncogenesis, as well as tumor development, invasion, and metastasis in PAC. Thus, immunosuppression-related signaling, especially that involving immune checkpoint and inflammation, has emerged as novel treatment targets for PAC. However, PAC is an immune-resistant tumor, and it is still unclear whether immune checkpoint or anti-inflammation therapies would be an ideal strategy. In this article, we will review immune checkpoint and inflammation as potential targets, as well as clinical trials and the prospects for immunotherapy in PAC.

Shikonin induces apoptosis of lung cancer cells via activation of FOXO3a/EGR1/SIRT1 signaling antagonized by p300

Shikonin derivatives exert powerful cytotoxic effects including induction of apoptosis. Here, we demonstrate the cytotoxic efficacy of shikonin in vivo in xenograft models, which did not affect body weight as well as its reduction of cell viability in vitro using several non-small cell lung cancer (NSCLC) cell lines. We found that inhibition of AKT by shikonin activated the forkhead box (FOX)O3a/early growth response protein (EGR)1 signaling cascade and enhanced the expression of the target gene Bim, leading to apoptosis in lung cancer cells. Overexpression of wild-type or a constitutively active mutant of FOXO3a enhanced shikonin-induced Bim expression. The NAD⁺-dependent histone deacetylase sirtuin (SIRT)1 amplified the pro-apoptotic effect by deacetylating FOXO3a, which induced EGR1 binding to the Bim promoter and activated Bim expression. Meanwhile, PI3K/AKT activity was enhanced, whereas that of FOXO3a was reduced and p300 was upregulated by treatment with a sublethal dose of shikonin. FOXO3a acetylation was enhanced by p300 overexpression, while shikonin-induced Bim expression was suppressed by p300 overexpression, which promoted cell survival. FOXO3a acetylation was increased by p300 overexpression and treatment with SIRT1 inhibitor, improving cell survival. In addition, shikonin-induced FOXO3a nuclear localization was blocked by AKT activation and SIRT1 inhibition, which blocked Bim expression and conferred resistance to the cytotoxic effects of shikonin. The EGR1 increase induced by shikonin was restored by pretreatment with SIRT1 inhibitor. These results suggest that shikonin induces apoptosis in some lung cancer cells via activation of FOXO3a/EGR1/SIRT1 signaling, and that AKT and p300 negatively regulate this process via Bim upregulation.

Targeted drugs in small-cell lung cancer

In contrast to non-small-cell lung cancer (NSCLC), few advances have been made in systemic treatment of small-cell lung cancer (SCLC) in recent years. Most patients are diagnosed with extensive stage disease and are commonly treated with platinum-based chemotherapy which, although attaining high initial objective responses, has a limited impact on survival. Due to the dismal prognosis of SCLC, novel and more effective treatment strategies are urgently needed. A deeper characterization of the genomic landscape of SCLC has led to the development of rational and promising targeted agents. However, despite a large number of clinical trials, results have been disappointing and there are still no approved targeted drugs for SCLC. Recent comprehensive genomic studies suggest SCLC is a heterogeneous disease, characterized by genomic alterations targeting a broad variety of genes, including those involved in transcription regulation and chromatin modification which seem to be a hallmark of this specific lung cancer subtype. Current research efforts are focusing on further understanding of the cellular and molecular abnormalities underlying SCLC development, progression and resistance to chemotherapy. Unraveling the genomic complexity of SCLC could be the key to optimize existing treatments, including chemotherapy and radiotherapy, and for identifying those patients most likely to benefit from selected targeted therapeutic approaches.