EGFR-TKI resistance promotes immune escape in lung cancer via increased PD-L1 expression

Immune regulation and the tumor microenvironment in anti-PD-1/PDL-1 and anti-CTLA-4 therapies for cancer immune evasion: A bibliometric analysis

This study aims to conduct a bibliometric analysis, employing visualization tools to examine literature pertaining to tumor immune evasion related to anti-CTLA-4 and anti-PD-1/PD-L1 therapy from 1999 to 2022. A special emphasis is placed on the interplay between tumor microenvironment, signaling pathways, immune cells and immune evasion, with data sourced from the Web of Science core collection (WoSCC). Advanced tools, including VOSviewer, Citespace, and Scimago Graphica, were utilized to analyze various parameters, such as co-authorship/co-citation patterns, regional contributions, journal preferences, keyword co-occurrences, and significant citation bursts. Out of 4778 publications reviewed, there was a marked increase in research focusing on immune evasion, with bladder cancer being notably prominent. Geographically, China, the USA, and Japan were the leading contributors. Prestigious institutions like MD Anderson Cancer Center, Harvard Medical School, Fudan University, and Sun Yat Sen University emerged as major players. Renowned journals in this domain included Frontiers in Immunology, Cancers, and Frontiers in Oncology. Ehen LP and Wang W were identified as prolific authors on this topic, while Topalian SL stood out as one of the most cited. Research current situation is notably pivoting toward challenges like immunotherapy resistance and the intricate signaling pathways driving drug resistance. This bibliometric study seeks to provide a comprehensive overview of past and current research trends, emphasizing the potential role of tumor microenvironment, signaling pathways and immune cells in the context of immune checkpoint inhibitors (ICIs) and tumor immune evasion.

Brain Metastasis from EGFR-Mutated Non-Small Cell Lung Cancer: Secretion of IL11 from Astrocytes Up-Regulates PDL1 and Promotes Immune Escape

Patients who have non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations are more prone to brain metastasis (BM) and poor prognosis. Previous studies showed that the tumor microenvironment of BM in these patients is immunosuppressed, as indicated by reduced T-cell abundance and activity, although the mechanism of this immunosuppression requires further study. This study shows that reactive astrocytes play a critical role in promoting the immune escape of BM from EGFR-mutated NSCLC by increasing the apoptosis of CD8+ T lymphocytes. The increased secretion of interleukin 11(IL11) by astrocytes promotes the expression of PDL1 in BM, and this is responsible for the increased apoptosis of T lymphocytes. IL11 functions as a ligand of EGFR, and this binding activates EGFR and downstream signaling to increase the expression of PDL1, culminating in the immune escape of tumor cells. IL11 also promotes immune escape by binding to its intrinsic receptor (IL11Rα/glycoprotein 130 [gp130]). Additional in vivo studies show that the targeted inhibition of gp130 and EGFR suppresses the growth of BM and prolongs the survival time of mice. These results suggest a novel therapeutic strategy for treatment of NSCLC patients with EGFR mutations.

Microbial metabolites affect tumor progression, immunity and therapy prediction by reshaping the tumor microenvironment (Review)

Several studies have indicated that the gut microbiome and tumor microbiota may affect tumors. Emerging metabolomics research illustrates the need to examine the variations in microbial metabolite composition between patients with cancer and healthy individuals. Microbial metabolites can impact the progression of tumors and the immune response by influencing a number of mechanisms, including modulation of the immune system, cancer or immune‑related signaling pathways, epigenetic modification of proteins and DNA damage. Microbial metabolites can also alleviate side effects and drug resistance during chemotherapy and immunotherapy, while effectively activating the immune system to exert tumor immunotherapy. Nevertheless, the impact of microbial metabolites on tumor immunity can be both beneficial and harmful, potentially influenced by the concentration of the metabolites or the specific cancer type. The present review summarizes the roles of various microbial metabolites in different solid tumors, alongside their influence on tumor immunity and treatment. Additionally, clinical trials evaluating the therapeutic effects of microbial metabolites or related microbes on patients with cancer have been listed. In summary, studying microbial metabolites, which play a crucial role in the interaction between the microbiota and tumors, could lead to the identification of new supplementary treatments for cancer. This has the potential to improve the effectiveness of cancer treatment and enhance patient prognosis.

Understanding the dynamics of TKI-induced changes in the tumor immune microenvironment for improved therapeutic effect

BACKGROUND

The dynamic interplay between tyrosine kinase inhibitors (TKIs) and the tumor immune microenvironment (TME) plays a crucial role in the therapeutic trajectory of non-small cell lung cancer (NSCLC). Understanding the functional dynamics and resistance mechanisms of TKIs is essential for advancing the treatment of NSCLC.

METHODS

This study assessed the effects of short-term and long-term TKI treatments on the TME in NSCLC, particularly targeting epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) mutations. We analyzed changes in immune cell composition, cytokine profiles, and key proteins involved in immune evasion, such as laminin subunit γ-2 (LAMC2). We also explored the use of aspirin as an adjunct therapy to modulate the TME and counteract TKI resistance.

RESULTS

Short-term TKI treatment enhanced T cell-mediated tumor clearance, reduced immunosuppressive M2 macrophage infiltration, and downregulated LAMC2 expression. Conversely, long-term TKI treatment fostered an immunosuppressive TME, contributing to drug resistance and promoting immune escape. Differential responses were observed among various oncogenic mutations, with ALK-targeted therapies eliciting a stronger antitumor immune response compared with EGFR-targeted therapies. Notably, we found that aspirin has potential in overcoming TKI resistance by modulating the TME and enhancing T cell-mediated tumor clearance.

CONCLUSIONS

These findings offer new insights into the dynamics of TKI-induced changes in the TME, improving our understanding of NSCLC challenges. The study underscores the critical role of the TME in TKI resistance and suggests that adjunct therapies, like aspirin, may provide new strategies to enhance TKI efficacy and overcome resistance.

Mechanisms, combination therapy, and biomarkers in cancer immunotherapy resistance

Anti-programmed death 1/programmed death ligand 1 (anti-PD-1/PD-L1) antibodies exert significant antitumor effects by overcoming tumor cell immune evasion and reversing T-cell exhaustion. However, the emergence of drug resistance causes most patients to respond poorly to these immune checkpoint inhibitors (ICIs). Studies have shown that insufficient T-cell infiltration, lack of PD-1 expression, deficient interferon signaling, loss of tumor antigen presentation, and abnormal lipid metabolism are all considered to be closely associated with immunotherapy resistance. To address drug resistance in tumor immunotherapy, a lot of research has concentrated on developing combination therapy strategies. Currently, ICIs such as anti-PD-1 /PD-L1 antibody combined with chemotherapy and targeted therapy have been approved for clinical treatment. In this review, we analyze the mechanisms of resistance to anti-PD-1/PD-L1 therapy in terms of the tumor microenvironment, gut microbiota, epigenetic regulation, and co-inhibitory immune checkpoint receptors. We also discuss various promising combination therapeutic strategies to address resistance to anti-PD-1/PD-L1 drugs, including combining these therapies with traditional Chinese medicine, non-coding RNAs, targeted therapy, other ICIs, and personalized cancer vaccines. Moreover, we focus on biomarkers that predict resistance to anti-PD-1/PD-L1 therapy as well as combination therapy efficacy. Finally, we suggest ways to further expand the application of immunotherapy through personalized combination strategies using biomarker systems.

Mutational variant allele frequency profile as a biomarker of response to immune checkpoint blockade in non-small cell lung Cancer

INTRODUCTION

Identifying new biomarkers for predicting immune checkpoint inhibitors (ICIs) response in non-small cell lung cancer (NSCLC) is crucial. We aimed to assess the variant allele frequency (VAF)-related profile as a novel biomarker for NSCLC personalized therapy.

METHODS

We utilized genomic data of 915 NSCLC patients via cBioPortal and a local cohort of 23 patients for model construction and mutational analysis. Genomic, transcriptomic data from 952 TCGA NSCLC patients, and immunofluorescence (IF) assessment with the local cohort supported mechanism analysis.

RESULTS

Utilizing the random forest algorithm, a 15-gene VAF-related model was established, differentiating patients with durable clinical benefit (DCB) from no durable benefit (NDB). The model demonstrated robust performance, with ROC-AUC values of 0.905, 0.737, and 0.711 across training (n = 313), internal validation (n = 133), and external validation (n = 157) cohorts. Stratification by the model into high- and low-score groups correlated significantly with both progression-free survival (PFS) (training: P < 0.0001, internal validation: P < 0.0001, external validation: P = 0.0066) and overall survival (OS) (n = 341) (P < 0.0001). Notably, the stratification system was independent of PD-L1 (P < 0.0001) and TMB (P < 0.0001). High-score patients exhibited an increased DCB ratio and longer PFS across both PD-L1 and TMB subgroups. Additionally, the high-score group appeared influenced by tobacco exposure, with activated DNA damage response pathways. Whereas, immune/inflammation-related pathways were enriched in the low-score group. Tumor immune microenvironment analyses revealed higher proportions of exhausted/effector memory CD8 + T cells in the high-score group.

CONCLUSIONS

The mutational VAF profile is a promising biomarker for ICI therapy in NSCLC, with enhanced therapeutic stratification and management as a supplement to PD-L1 or TMB.

Case report: Sustained remission after combined sintilimab, anti-VEGF therapy, and chemotherapy in a patient with non-small cell lung cancer harboring acquired EGFR 19Del/T790M/cis-C797S mutation resistance

Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are highly effective against tumors harboring the T790M mutation. However, patients treated with these inhibitors ultimately develop resistance, and the most common mechanism is the emergence of the EGFR C797S mutation. Few treatment regimens have been reported for this condition. In this report, we present a successful combination treatment with the programmed cell death 1 (PD-1) inhibitor sintilimab, anti-vascular endothelial growth factor (VEGF) therapy, and chemotherapy with pemetrexed and cisplatin in a patient with non-small cell lung cancer (NSCLC) who developed acquired resistance with EGFR 19 exon deletion (19Del)/T790M/cis-C797S mutation following progression with ametinib therapy. This regimen was well tolerated, and the patient has remained progression-free for 15 months. Our case provides clinical evidence that the combination of PD-1 inhibitor, anti-VEGF therapy, and chemotherapy may be an efficacious therapeutic strategy for NSCLC patients with acquired EGFR 19Del/T790M/cis-C797S mutation resistance following progression with EGFR TKI therapy.

EGFR-mutant NSCLC may remodel TME from non-inflamed to inflamed through acquiring resistance to EGFR-TKI treatment

BACKGROUND

EGFR-TKI represent the standard first-line therapy for advanced NSCLC harboring EGFR mutations. However, resistance to EGFR-TKI inevitably develops in nearly all patients. Previous clinical study have demonstrated that, some patients that failed EGFR-TKI therapy show a benefit outcome from immunotherapy. Our objective is to explore the immune microenviroment remodeling induced by EGFR-TKI treatment in EGFR mutant lung cancer patients and to investigate the immune cell types and potential molecular signatures involved.

METHODS

A cohort of 37 EGFR mutant advanced-stage NSCLC patients, who are resistant to at least one type of TKI treatment, was retrospectively established. Both pre-treatment and TKI resistance tumor FFPE samples of each pairs were collected. Transcriptional profiling and bioinformatics analysis were employed to evaluate the change of immune associated hallmarks before and after EGFR-TKI therapy.

RESULTS

Tumor samples after EGFR-TKI treatment displayed enrichment of proinflammatory signaling like interferon-γ, allograft rejection and inflammatory response. Of note, cytotoxic factor granzyme A as well as PD-L1 were found to be more expressed in EGFR-TKI resistance samples. Approximately 33.3 % (11/33) of EGFR-TKI treated samples were classified as "hot" tumor, especially for EGFR L858R mutated NSCLC patients (46.7 %,7/15). Effector cells were significantly overexpressed in 'hot' tumors feature following TKI resistance. In addition, we found that four effector genes (CD8A, CDB8, GZMB, GZMK) showed higher expression in 'hot' tumors post-TKI resistance, and its 4-gene effector cell signature was found to have a good correlation with survival benefit in external immunotherapy database.

CONCLUSIONS

TKI treatment may initiate immune activation in EGFR mutant NSCLC, leading to changes in immune cell infiltration following TKI resistance. We mechanistically explored that this might be due to an increased immune response caused by the rise in effector cells post-TKI resistance.

Trimethyl chitosan-cysteine-based nanoparticles as an effective delivery system for portulacerebroside A in the management of hepatocellular carcinoma cells in vitro and in vivo

Portulacerebroside A (PCA), a cerebroside compound extracted from Portulaca oleracea L., has been shown to suppress hepatocellular carcinoma (HCC) cells. This study aims to investigate the effectiveness of trimethyl chitosan-cysteine (TMC-Cys) nanocarrier in delivering PCA for HCC management and to elucidate the molecular mechanisms behind PCA's function. TMC-Cys nanocarriers notably augmented PCA's function, diminishing the proliferation, migration, and invasiveness of HCC cells in vitro, reducing hepatocellular tumorigenesis in immunocompetent mice, and impeding metastasis of xenograft tumours in nude mice. Comprehensive bioinformatics analyses, incorporating Super-PRED systems alongside pathway enrichment analysis, pinpointed toll-like receptor 4 (TLR4) and epidermal growth factor receptor (EGFR) as two promising targets of PCA, enriched in immune checkpoint pathway. PCA/nanocarrier (PCA) reduced levels of TLR4 and EGFR and their downstream proteins, including programmed cell death ligand 1, thereby increasing populations and activity of T cells co-cultured with HCC cells in vitro or in primary HCC tumours in mice. However, these effects were counteracted by additional artificial activation of TLR4 and EGFR. In conclusion, this study provides novel evidence of PCA's function in immunomodulation in addition to its direct tumour suppressive effect. TMC-Cys nanocarriers significantly enhance PCA efficacy, indicating promising application as a drug delivery system.

A computational pipeline for identifying gene targets and signalling pathways in cancer cells to improve lymphocyte infiltration and immune checkpoint therapy efficacy

BACKGROUND

Tumour-infiltrating lymphocytes (TILs) are crucial for effective immune checkpoint blockade (ICB) therapy in solid tumours. However, ∼70% of these tumours exhibit poor lymphocyte infiltration, rendering ICB therapies less effective.

METHODS

We developed a bioinformatics pipeline integrating multiple previously unconsidered factors or datasets, including tumour cell immune-related pathways, copy number variation (CNV), and single tumour cell sequencing data, as well as tumour mRNA-seq data and patient survival data, to identify targets that can potentially improve T cell infiltration and enhance ICB efficacy. Furthermore, we conducted wet-lab experiments and successfully validated one of the top-identified genes.

FINDINGS

We applied this pipeline in solid tumours of the Cancer Genome Atlas (TCGA) and identified a set of genes in 18 cancer types that might potentially improve lymphocyte infiltration and ICB efficacy, providing a valuable drug target resource to be further explored. Importantly, we experimentally validated SUN1, which had not been linked to T cell infiltration and ICB therapy previously, but was one of the top-identified gene targets among 3 cancer types based on the pipeline, in a mouse colon cancer syngeneic model. We showed that Sun1 KO could significantly enhance antigen presentation, increase T-cell infiltration, and improve anti-PD1 treatment efficacy. Moreover, with a single-cell multiome analysis, we identified subgene regulatory networks (sub-GRNs) showing Stat proteins play important roles in enhancing the immune-related pathways in Sun1-KO cancer cells.

INTERPRETATION

This study not only established a computational pipeline for discovering new gene targets and signalling pathways in cancer cells that block T-cell infiltration, but also provided a gene target pool for further exploration in improving lymphocyte infiltration and ICB efficacy in solid tumours.

FUNDING

A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.

PD-L2 drives resistance to EGFR-TKIs: dynamic changes of the tumor immune environment and targeted therapy

There is a lack of effective treatments to overcome resistance to EGFR-TKIs in EGFR mutant tumors. A deeper understanding of resistance mechanisms can provide insights into reducing or eliminating resistance, and can potentially deliver targeted treatment measures to overcome resistance. Here, we identified that the dynamic changes of the tumor immune environment were important extrinsic factors driving tumor resistance to EGFR-TKIs in EGFR mutant cell lines and syngeneic tumor-bearing mice. Our results demonstrate that the acquired resistance to EGFR-TKIs is accompanied by aberrant expression of PD-L2, leading a dynamic shift from an initially favorable tumor immune environment to an immunosuppressive phenotype. PD-L2 expression significantly affected EGFR mutant cell apoptosis that depended on the proportion and function of CD8+ T cells in the tumor immune environment. Combined with single-cell sequencing and experimental results, we demonstrated that PD-L2 specifically inhibited the proliferation of CD8+ T cells and the secretion of granzyme B and perforin, leading to reduced apoptosis mediated by CD8+ T cells and enhanced immune escape of tumor cells, which drives EGFR-TKIs resistance. Importantly, we have identified a potent natural small-molecule inhibitor of PD-L2, zinc undecylenate. In vitro, it selectively and potently blocks the PD-L2/PD-1 interaction. In vivo, it abolishes the suppressive effect of the PD-L2-overexpressing tumor immune microenvironment by blocking PD-L2/PD-1 signaling. Moreover, the combination of zinc undecylenate and EGFR-TKIs can synergistically reverse tumor resistance, which is dependent on CD8+ T cells mediating apoptosis. Our study uncovers the PD-L2/PD-1 signaling pathway as a driving factor to mediate EGFR-TKIs resistance, and identifies a new naturally-derived agent to reverse EGFR-TKIs resistance.

The later-line efficacy and safety of immune checkpoint inhibitors plus anlotinib in EGFR-mutant patients with EGFR-TKI-resistant NSCLC: a single-center retrospective study

BACKGROUND

Effective treatment after EGFR-TKI resistance is of great clinical concern. We aimed to investigate the efficacy and safety of anlotinib in combination with an anti-PD-1/PD-L1 antibody in later-line therapy for EGFR-mutant NSCLC patients after TKI treatment failure and to explore the independent predictive factors of therapeutic efficacy.

METHODS

A total of 71 patients with confirmed advanced EGFR-mutated NSCLC who progressed after previous standard EGFR-TKI therapy but still failed after multiline treatments were included retrospectively in this study. Most of the patients had previously received at least three lines of treatment. All were treated with anlotinib combined with anti-PD-1 or anti-PD-L1 therapy. The safety of this combined treatment was assessed by the incidence of adverse events. The efficacy of the regimens was evaluated by survival analysis (OS, PFS, ORR, DCR).

RESULTS

The median follow-up period was 28.6 months (range: 2.3-54.0 months), and the median number of treatment lines was 4. The overall response rate (ORR) and disease control rate (DCR) were 19.7% and 77.5%, respectively. The median PFS was 5.8 months (95% CI 4.2-7.4 months), and the median OS was 17.1 months (95% CI 12.0-22.3 months). Patients who received immune checkpoint inhibitors plus anlotinib had an encouraging intracranial ORR of 38.5% and a DCR of 80.8%. ECOG performance status < 2 at baseline was independent protective factors of PFS. Metastatic organs and ECOG performance status were independent parameters in predicting OS. Treatment-related adverse events occurred in 66 (93.0%) patients; most of the adverse events were Grade 1-2, and no increase in adverse events was observed compared to monotherapy.

CONCLUSION

Anlotinib combined with an anti-PD-1/PD-L1-based regimen exhibited promising efficacy and tolerance in NSCLC patients with EGFR mutations after previous TKI failure. The efficacy of this combined regimen in patients with EGFR mutations should be further evaluated.

METTL14 regulates CD8+T-cell activation and immune responses to anti-PD-1 therapy in lung cancer

BACKGROUND

N6-methyladenosine (m6A) modification plays an important role in lung cancer. However, methyltransferase-like 14 (METTL14), which serves as the main component of the m6A complex, has been less reported to be involved in the immune microenvironment of lung cancer. This study aimed to analyze the relationship between METTL14 and the immune checkpoint inhibitor programmed death receptor 1 (PD-1) in lung cancer.

METHODS

CCK-8, colony formation, transwell, wound healing, and flow cytometry assays were performed to explore the role of METTL14 in lung cancer progression in vitro. Furthermore, syngeneic model mice were treated with sh-METTL14 andan anti-PD-1 antibody to observe the effect of METTL14 on immunotherapy. Flow cytometry and immunohistochemical (IHC) staining were used to detect CD8 expression. RIP and MeRIP were performed to assess the relationship between METTL14 and HSD17B6. LLC cells and activated mouse PBMCs were cocultured in vitro to mimic immune cell infiltration in the tumor microenvironment. ELISA was used to detect IFN-γ and TNF-α levels.

RESULTS

The online database GEPIA showed that high METTL14 expression indicated a poor prognosis in patients with lung cancer. In vitro assays suggested that METTL14 knockdown suppressed lung cancer progression. In vivo assays revealed that METTL14 knockdown inhibited tumor growth and enhanced the response to PD-1 immunotherapy. Furthermore, METTL14 knockdown enhanced CD8+T-cell activation and infiltration. More importantly, METTL14 knockdown increased the stability of HSD17B6 mRNA by reducing its m6A methylation. In addition, HSD17B6 overexpression promoted the activation of CD8+ T cells.

CONCLUSION

The disruption of METTL14 contributed to CD8+T-cell activation and the immunotherapy response to PD-1 via m6A modification of HSD17B6, thereby suppressing lung cancer progression.

Specific lineage transition of tumor-associated macrophages elicits immune evasion of ascitic tumor cells in gastric cancer with peritoneal metastasis

BACKGROUND

Gastric cancer with peritoneal metastasis (PM-GC), recognized as one of the deadliest cancers. However, whether and how the tumor cell-extrinsic tumor microenvironment (TME) is involved in the therapeutic failure remains unknown. Thus, this study systematically assessed the immunosuppressive tumor microenvironment in ascites from patients with PM-GC, and its contribution to dissemination and immune evasion of ascites-disseminated tumor cells (aDTCs).

METHODS

Sixty-three ascites and 43 peripheral blood (PB) samples from 51 patients with PM-GC were included in this study. aDTCs in ascites and circulating tumor cells (CTCs) in paired PB were immunophenotypically profiled. Using single-cell RNA transcriptional sequencing (scRNA-seq), crosstalk between aDTCs and the TME features of ascites was inspected. Further studies on the mechanism underlying aDTCs-immune cells crosstalk were performed on in vitro cultured aDTCs.

RESULTS

Immune cells in ascites interact with aDTCs, prompting their immune evasion. Specifically, we found that the tumor-associated macrophages (TAMs) in ascites underwent a continuum lineage transition from cathepsinhigh (CTShigh) to complement 1qhigh (C1Qhigh) TAM. CTShigh TAM initially attracted the metastatic tumor cells to ascites, thereafter, transitioning terminally to C1Qhigh TAM to trigger overproliferation and immune escape of aDTCs. Mechanistically, we demonstrated that C1Qhigh TAMs significantly enhanced the expression of PD-L1 and NECTIN2 on aDTCs, which was driven by the activation of the C1q-mediated complement pathway.

CONCLUSIONS

For the first time, we identified an immunosuppressive macrophage transition from CTShigh to C1Qhigh TAM in ascites from patients with PM-GC. This may contribute to developing potential TAM-targeted immunotherapies for PM-GC.

The detection of PD-L1 expression on liquid-based cytology in pleural effusion of lung adenocarcinoma and its prognostic evaluation: Between paired liquid-based cytology and cell block samples

BACKGROUND

Programmed death-ligand 1 (PD-L1) expression levels measured by immunohistochemistry have been proven to predict the outcome of immunotherapy in lung adenocarcinoma (LUAD). However, data on PD-L1 expression on liquid-based cytology (LBC) in malignant pleural effusion (MPE) is scarce.

METHODS

This study cohort included 60 cases with MPE suffering from LUAD. PD-L1 SP263 assay was used for immunocytochemistry (ICC) on LBC and matched cell block (CB) to validate ICC protocols on LBC slides. Clinical outcomes were analyzed based on immunotherapy and PD-L1 tumor proportion scores (TPS) on LBC slides and CBs.

RESULTS

PD-L1 expression with TPS ≥1% was lower in LBCs than in CBs (33 of 60 [55.0%] vs. 35 of 60 [58.3%]; p = .687). Even with the TPS ≥50% threshold, PD-L1 expression was lower in LBCs (10 of 60 [16.7%] vs. 15 of 60 [25%]; p = .125). Epidermal growth factor receptor (EGFR) exon 20 mutation, tumor cell proportion, and pleural fluid neutrophil-to-lymphocyte ratio were related to PD-L1 expression on CBs (p = .013, p = 0.022, and p = .011), respectively. Patients with subsequent immune checkpoint inhibitor therapy remained a better prognostic in subgroups of PD-L1 positive expression on LBC slides (TPS ≥1%, p = .041).

CONCLUSIONS

LBC specimens had comparable performance to CBs in PD-L1 assessment and predicting treatment response to PD-L1-defined therapy.

Chidamide improves gefitinib treatment outcomes in NSCLC by attenuating recruitment and immunosuppressive function of myeloid-derived suppressor cells

Clinical resistance to EGFR tyrosine kinase inhibitors in non-small-cell lung cancer (NSCLC) remains a significant challenge. Recent studies have indicated that the number of myeloid-derived suppressor cells (MDSCs) increases following gefitinib treatment, correlating with a poor patient response in NSCLC. Our study revealed that gefitinib treatment stimulates the production of CCL2, which subsequently enhances monocyte (M)-MDSC migration to tumor sites. Chidamide, a selective inhibitor of the histone deacetylase subtype, counteracted the gefitinib-induced increase in CCL2 levels in tumor cells. Additionally, chidamide down-regulated the expression of CCR2 in M-MDSCs, inhibiting their migration. Furthermore, chidamide attenuated the immunosuppressive function of M-MDSCs both alone and in combination with gefitinib. Chidamide also alleviated tumor immunosuppression by reducing the number of M-MDSCs in LLC-bearing mice, thereby enhancing the antitumor efficacy of gefitinib. In conclusion, our findings suggest that chidamide can improve gefitinib treatment outcomes, indicating that MDSCs are promising targets in NSCLC.

NEAT1_1 confers gefitinib resistance in lung adenocarcinoma through promoting AKR1C1-mediated ferroptosis defence

Gefitinib is one of the most extensively utilized epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) for treating advanced lung adenocarcinoma (LUAD) patients harboring EGFR mutation. However, the emergence of drug resistance significantly compromised the clinical efficacy of EGFR-TKIs. Gaining further insights into the molecular mechanisms underlying gefitinib resistance holds promise for developing novel strategies to overcome the resistance and improve the prognosis in LUAD patients. Here, we identified that the inhibitory efficacy of gefitinib on EGFR-mutated LUAD cells was partially dependent on the induction of ferroptosis, and ferroptosis protection resulted in gefitinib resistance. Among the ferroptosis suppressors, aldo-keto reductase family 1 member C1 (AKR1C1) exhibited significant upregulation in gefitinib-resistant strains of LUAD cells and predicted poor progression-free survival (PFS) and overall survival (OS) of LUAD patients who received first-generation EGFR-TKI treatment. Knockdown of AKR1C1 partially reversed drug resistance by re-sensitizing the LUAD cells to gefitinib-mediated ferroptosis. The decreased expression of miR-338-3p contributed to the aberrant upregulation of AKR1C1 in gefitinib-resistant LUAD cells. Furthermore, upregulated long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1_1 (NEAT1_1) sponged miR-338-3p to neutralize its suppression on AKR1C1. Dual-luciferase reporter assay and miRNA rescue experiment confirmed the NEAT1_1/miR-338-3p/AKR1C1 axis in EGFR-mutated LUAD cells. Gain- and loss-of-function assays demonstrated that the NEAT1_1/miR-338-3p/AKR1C1 axis promoted gefitinib resistance, proliferation, migration, and invasion in LUAD cells. This study reveals the effects of NEAT1_1/miR-338-3p/AKR1C1 axis-mediated ferroptosis defence in gefitinib resistance in LUAD. Thus, targeting NEAT1_1/miR-338-3p/AKR1C1 axis might be a novel strategy for overcoming gefitinib resistance in LUAD harboring EGFR mutation.

Blockade of PD-1 and CTLA-4: A potent immunotherapeutic approach for hepatocellular carcinoma

Immune checkpoints (ICPs) can promote tumor growth and prevent immunity-induced cancer cell apoptosis. Fortunately, targeting ICPs, such as programmed cell death 1 (PD-1) or cytotoxic T lymphocyte associated protein 4 (CTLA-4), has achieved great success in the past few years and has gradually become an effective treatment for cancers, including hepatocellular carcinoma (HCC). However, many patients do not respond to ICP therapy due to acquired resistance and recurrence. Therefore, clarifying the specific mechanisms of ICP in the development of HCC is very important for enhancing the efficacy of anti-PD-1 and anti-CTLA-4 therapy. In particular, antigen presentation and interferon-γ (IFN-γ) signaling were reported to be involved in the development of resistance. In this review, we have explained the role and regulatory mechanisms of ICP therapy in HCC pathology. Moreover, we have also elaborated on combinations of ICP inhibitors and other treatments to enhance the antitumor effect. Collectively, recent advances in the pharmacological targeting of ICPs provide insights for the development of a novel alternative treatment for HCC.

Prognosis value of circulating tumor cell PD‑L1 and baseline characteristics in patients with NSCLC treated with immune checkpoint inhibitors plus platinum‑containing drugs

Immune checkpoint inhibitors (ICIs) combined with platinum-containing chemotherapy are recommended as the standard first-line treatment for non-small cell lung cancer (NSCLC). However, specific prognostic markers for this combination therapy are yet to be identified. Evaluation of circulating tumor cells (CTCs) and cell surface programmed death-ligand 1 (PD-L1) exhibits potential in predicting the efficacy of the aforementioned combination therapy. Thus, the present study aimed to evaluate the prognostic value of CTC PD-L1 testing and other clinical characteristics in patients with NSCLC treated with combination therapy as first-line treatment. In total, 40 patients with advanced NSCLC were included in the present study, and all patients underwent CTC PD-L1 testing at initial diagnosis to determine the association between CTC PD-L1 and tissue PD-L1. The prognostic value of CTC PD-L1 and the baseline characteristics of 26 patients with NSCLC were analyzed, and the prognostic values of changes in CTC PD-L1 and baseline characteristics during 6 months of treatment were further explored. Results of the present study demonstrated that there was no association between CTC PD-L1 and tissue PD-L1 levels. After 6 months of combination therapy, tumor shrinkage, CYFA19 levels and treatment maintenance were associated with progression-free survival (PFS) of patients. Notably, CTC PD-L1 and tissue PD-L1 levels, TNM stage, nutritional score, inflammation score and other blood indicators were not associated with PFS. In conclusion, the evaluation of CTCs and CTC PD-L1 suggested that undetectable CTCs at 6 months of NSCLC treatment are associated with a good prognosis. In addition, negative CTC PD-L1 expression may change to positive CTC PD-L1 expression in line with disease progression, and this may be indicative of poor prognosis.

From immune checkpoints to therapies: understanding immune checkpoint regulation and the influence of natural products and traditional medicine on immune checkpoint and immunotherapy in lung cancer

Lung cancer is a disease of global concern, and immunotherapy has brought lung cancer therapy to a new era. Besides promising effects in the clinical use of immune checkpoint inhibitors, immune-related adverse events (irAEs) and low response rates are problems unsolved. Natural products and traditional medicine with an immune-modulating nature have the property to influence immune checkpoint expression and can improve immunotherapy's effect with relatively low toxicity. This review summarizes currently approved immunotherapy and the current mechanisms known to regulate immune checkpoint expression in lung cancer. It lists natural products and traditional medicine capable of influencing immune checkpoints or synergizing with immunotherapy in lung cancer, exploring both their effects and underlying mechanisms. Future research on immune checkpoint modulation and immunotherapy combination applying natural products and traditional medicine will be based on a deeper understanding of their mechanisms regulating immune checkpoints. Continued exploration of natural products and traditional medicine holds the potential to enhance the efficacy and reduce the adverse reactions of immunotherapy.

IGFBP3 induces PD-L1 expression to promote glioblastoma immune evasion

BACKGROUND

Glioblastoma (GBM) characterized by immune escape is the most malignant primary brain tumors, which has strong immunosuppressive effect. Programmed death ligand-1 (PD-L1) is a recognized immunosuppressive member on the surface of tumor cells, and plays a crucial role in immune evasion of tumors. Actually, little is known about the regulation of PD-L1 expression in GBM. Insulin-like growth factor binding protein 3 (IGFBP3) is upregulated in GBM and is related to poor patient prognosis. However, it remains unclear whether IGFBP3 plays a role in the regulation of PD-L1 expression in GBM.

METHODS

The role of IGFBP3 in the glioma immune microenvironment was investigated using the CIBERSORT algorithm. The correlation between IGFBP3 and PD-L1 expression was analyzed using TCGA and CGGA databases. QRT-PCR, immunoblotting and RNA-seq were used to examine the regulatory effect of IGFBP3 on PD-L1 expression. Co-culture assay, cell counting kit (CCK-8), qRT-PCR, ELISA and flow cytometry were performed to explore the function of IGFBP3 in inducing immunosuppression. The biological role of IGFBP3 was verified using immunohistochemical, immunofluorescence and mice orthotopic tumor model.

RESULTS

In this study, we analyzed immune cells infiltration in gliomas and found that IGFBP3 may be associated with an immunosuppressive microenvironment. Then, by analyzing TCGA and CGGA databases, our results showed that IGFBP3 and PD-L1 expression were positively correlated in GBM patients, but not in LGG patients. In vitro experiments conducted on different GBM cell lines revealed that the overexpression of IGFBP3 led to an increase in PD-L1 expression, which was reversible upon knockdown IGFBP3. Mechanistically, IGFBP3 activated the JAK2/STAT3 signaling pathway, leading to an increase in PD-L1 expression. Additionally, co-culture experiments results showed IGFBP3 overexpression induced upregulation of PD-L1 expression promoted apoptosis in Jurkat cells, and this effect was blocked by IGFBP3 antibody and PDL-1 inhibitors. Importantly, in vivo experiments targeting IGFBP3 suppressed tumor growth and significantly prolonged the survival of mice.

CONCLUSIONS

This research demonstrated IGFBP3 is a novel regulator for PD-L1 expression in GBM, and identified a new mechanism by which IGFBP3 regulates immune evasion through PD-L1, suggesting that IGFBP3 may be a potential novel target for GBM therapy.

MET exon 14 skipping mutation drives cancer progression and recurrence via activation of SMAD2 signalling

BACKGROUND

c-Met encoded by the proto-oncogene MET, also known as hepatocyte growth factor (HGF) receptor, plays a crucial role in cellular processes. MET exon 14 skipping alteration (METΔ14EX) is a newly discovered MET mutation. SMAD2 is an important downstream transcription factor in TGF-β pathway. Unfortunately, the mechanisms by which METΔ14EX leads to oncogenic transformation are scarcely understood. The relationship between METΔ14EX and SMAD2 has not been studied yet.

METHODS

We generate METΔ14EX models by CRISPR-Cas9. In vitro transwell, wound-healing, soft-agar assay, in vivo metastasis and subcutaneous recurrence assay were used to study the role of METΔ14EX in tumour progression. RNA-seq, Western blotting, co-immunoprecipitation (CO-IP) and immunofluorescent were performed to explore the interaction between c-Met and SMAD2.

RESULTS

Our results demonstrated that METΔ14EX, independent of HGF, can prolong the constitutive activation of c-Met downstream signalling pathways by impeding c-Met degradation and facilitating tumour metastasis and recurrence. Meanwhile, METΔ14EX strengthens the interaction between c-Met and SMAD2, promoting SMAD2 phosphorylation. Therapeutically, MET inhibitor crizotinib impedes METΔ14EX-mediated tumour metastasis by decreasing SMAD2 phosphorylation.

CONCLUSIONS

These data elucidated the previously unrecognised role of METΔ14EX in cancer progression via activation of SMAD2 independent of TGF-β, which helps to develop more effective therapies for such patients. METΔ14EX alteration significantly triggers tumour progression via activation of SMAD2 signalling that are involved in activating tumour invasion, metastasis and recurrence. On the left, in the MET wild-type (METWT), the juxtamembrane (JM) domain is involved in the regulation of tyrosine kinase activity, receptor degradation, and caspase cleavage. On the right, the METΔ14EX mutation leads to the loss of the juxtamembrane domain, resulting in an abnormal MET protein lacking a CBL-binding site. This causes the accumulation of truncated MET receptors followed by constitutive activation of the MET signalling pathway. Thus, the METΔ14EX-mutated protein has strong binding and phosphorylation to SMAD2, which results in the phosphorylation of a large number of SMAD2/3 proteins that combine with SMAD4 to form a complex in the nucleus, activating downstream signalling pathways, such as EMT and ECM remodelling, resulting in tumour progression and recurrence. TF transcription factor.

[Progress of Immunotherapy in EGFR-mutated Advanced Non-small Cell Lung Cancer]

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are currently the first-line standard of care for patients with non-small cell lung cancer (NSCLC) that harbor EGFR mutations. Nevertheless, resistance to EGFR-TKIs is inevitable. In recent years, although immune checkpoint inhibitors (ICIs) have significantly shifted the treatment paradigm in advanced NSCLC without driver mutation, clinical benefits of these agents are limited in patients with EGFR-mutated NSCLC. Compared with wild-type tumors, tumors with EGFR mutations show more heterogeneity in the expression level of programmed cell death ligand 1 (PD-L1), tumor mutational burden (TMB), and other tumor microenvironment (TME) characteristics. Whether ICIs are suitable for NSCLC patients with EGFR mutations is still worth exploring. In this review, we summarized the clinical data with regard to the efficacy of ICIs in patients with EGFR-mutated NSCLC and deciphered the unique TME in EGFR-mutated NSCLC.
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Advances and challenges in the treatment of lung cancer

Lung cancer accounts for a relatively high proportion of malignant tumors. As the most prevalent type of lung cancer, non-small cell lung cancer (NSCLC) is characterized by high morbidity and mortality. Presently, the arsenal of treatment strategies encompasses surgical resection, chemotherapy, targeted therapy and radiotherapy. However, despite these options, the prognosis remains distressingly poor with a low 5-year survival rate. Therefore, it is urgent to pursue a paradigm shift in treatment methodologies. In recent years, the advent of sophisticated biotechnologies and interdisciplinary integration has provided innovative approaches for the treatment of lung cancer. This article reviews the cutting-edge developments in the nano drug delivery system, molecular targeted treatment system, photothermal treatment strategy, and immunotherapy for lung cancer. Overall, by systematically summarizing and critically analyzing the latest progress and current challenges in these treatment strategies of lung cancer, we aim to provide a theoretical basis for the development of novel drugs for lung cancer treatment, and thus improve the therapeutic outcomes for lung cancer patients.

Nanomaterials-based precision sonodynamic therapy enhancing immune checkpoint blockade: A promising strategy targeting solid tumor

Burgeoning is an evolution from conventional photodynamic therapy (PDT). Thus, sonodynamic therapy (SDT) regulated by nanoparticles (NPs) possesses multiple advantages, including stronger penetration ability, better biological safety, and not reactive oxygen species (ROS)-dependent tumor-killing effect. However, the limitation to tumor inhibition instead of shrinkage and the incapability of eliminating metastatic tumors hinder the clinical potential for SDT. Fortunately, immune checkpoint blockade (ICB) can revive immunological function and induce a long-term immune memory against tumor rechallenges. Hence, synergizing NPs-based SDT with ICB can provide a promising therapeutic outcome for solid tumors. Herein, we briefly reviewed the progress in NPs-based SDT and ICB therapy. We highlighted the synergistic anti-tumor mechanisms and summarized the representative preclinical trials on SDT-assisted immunotherapy. Compared to other reviews, we provided comprehensive and unique perspectives on the innovative sonosensitizers in each trial. Moreover, we also discussed the current challenges and future corresponding solutions.

Hsa-LINC02418/mmu-4930573I07Rik regulated by METTL3 dictates anti-PD-L1 immunotherapeutic efficacy via enhancement of Trim21-mediated PD-L1 ubiquitination

BACKGROUND

Limited response to programmed death ligand-1 (PD-L1)/programmed death 1 (PD-1) immunotherapy is a major hindrance of checkpoint immunotherapy in non-small cell lung cancer (NSCLC). The abundance of PD-L1 on the tumor cell surface is crucial for the responsiveness of PD-1/PD-L1 immunotherapy. However, the negative control of PD-L1 expression and the physiological significance of the PD-L1 inhibition in NSCLC immunotherapy remain obscure.

METHODS

Bioinformatics analysis was performed to profile and investigate the long non-coding RNAs that negatively correlated with PD-L1 expression and positively correlated with CD8+T cell infiltration in NSCLC. Immunofluorescence, in vitro PD-1 binding assay, T cell-induced apoptosis assays and in vivo syngeneic mouse models were used to investigate the functional roles of LINC02418 and mmu-4930573I07Rik in regulating anti-PD-L1 therapeutic efficacy in NSCLC. The molecular mechanism of LINC02418-enhanced PD-L1 downregulation was explored by immunoprecipitation, RNA immunoprecipitation (RIP), and ubiquitination assays. RIP, luciferase reporter, and messenger RNA degradation assays were used to investigate the m6A modification of LINC02418 or mmu-4930573I07Rik expression. Bioinformatics analysis and immunohistochemistry (IHC) verification were performed to determine the significance of LINC02418, PD-L1 expression and CD8+T cell infiltration.

RESULTS

LINC02418 is a negative regulator of PD-L1 expression that positively correlated with CD8+T cell infiltration, predicting favorable clinical outcomes for patients with NSCLC. LINC02418 downregulates PD-L1 expression by enhancing PD-L1 ubiquitination mediated by E3 ligase Trim21. Both hsa-LINC02418 and mmu-4930573I07Rik (its homologous RNA in mice) regulate PD-L1 therapeutic efficacy in NSCLC via Trim21, inducing T cell-induced apoptosis in vitro and in vivo. Furthermore, METTL3 inhibition via N6-methyladenosine (m6A) modification mediated by YTHDF2 reader upregulates hsa-LINC02418 and mmu-4930573I07Rik. In patients with NSCLC, LINC02418 expression is inversely correlated with PD-L1 expression and positively correlated with CD8+T infiltration.

CONCLUSION

LINC02418 functions as a negative regulator of PD-L1 expression in NSCLC cells by promoting the degradation of PD-L1 through the ubiquitin-proteasome pathway. The expression of LINC02418 is regulated by METTL3/YTHDF2-mediated m6A modification. This study illuminates the underlying mechanisms of PD-L1 negative regulation and presents a promising target for improving the effectiveness of anti-PD-L1 therapy in NSCLC.

Immunotherapy strategies for EGFR-mutated advanced NSCLC after EGFR tyrosine-kinase inhibitors failure

Background

This study aimed to investigate the efficacy of immunotherapy, as monotherapy or in combination, comparing to chemotherapy with or without anti-angiogenesis for advanced non-small cell lung cancer (NSCLC) patients progressing to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs).

Methods

We retrospectively analyzed patients with advanced NSCLC harboring EGFR mutations who received immune checkpoint inhibitors (ICI) and/or chemotherapy after EGFR-TKIs failure at Shanghai Chest Hospital between Aug 2016 and Oct 2022. According to the subsequent immunotherapy regimen, the patients were assigned to ICI monotherapy (IM), IO plus anti-angiogenesis (IA), ICI plus chemotherapy (IC), ICI plus chemotherapy plus anti-angiogenesis (ICA). Eligible patients undergoing standard chemotherapy were assigned to chemotherapy plus anti-angiogenesis (CA) and chemotherapy alone (CM). Efficacy was evaluated according to the RECIST 1.1version, and calculated the objective response rate (ORR) and disease control rate (DCR). Survival curves were plotted using the Kaplan-Meier method, and the median progression-free survival (PFS) was calculated. Differences among survival curves of the six groups were assessed using the log-rank test.

Results

A total of 237 advanced NSCLC patients with EGFR mutations were included in this study. Of the 160 patients who received immunotherapy, 57 received ICI monotherapy, 27 received ICI plus anti-angiogenesis therapy, 43 received ICI plus chemotherapy, and 33 received ICI plus anti-angiogenesis plus chemotherapy. 77 patients received standard chemotherapy, of which 30 received chemotherapy plus anti-angiogenesis and 47 received chemotherapy alone. Patients in ICA group showed significant longer PFS than IM (7.2 vs 1.9 months, P=0.011), IA (7.2 vs 4.8 months, P=0.009) and CM group (7.2 vs 4.4 months, P=0.005). There was no significant difference in PFS between the ICA and IC (7.2 vs 5.6 months, P=0.104) or CA (7.2 vs 6.7 months, P=0.959) group. Meanwhile, the ICA group showed the highest ORR and DCR (36.4% and 90.9%) compared to the other five groups. The IC group had a higher ORR than the IA and CA group (32.6% vs 7.4% vs 10.0%, respectively), but the DCR was comparable (79.1% vs 74.1% vs 76.7%, respectively). The ORR of the CM group was 6.4% and the DCR was 66.0%. IM group showed the lowest ORR and DCR (1.8% and 36.8%). Treatment-related adverse events (TRAEs) of grade 3 or worse occurred in 9 (27.3%) patients in the ICA group, 6 (20.0%) in the CA group, 7 (14.9%) in the CM group, 5 (11.6%) in the IC group, 5 (8.8%) in the IM group, and 2 (7.4%) in the IA group.

Conclusion

NSCLC patients with positive EGFR mutations after EGFR-TKIs failure received subsequent immunotherapy plus anti-angiogenesis and chemotherapy are likely to have more benefits in ORR, DCR and mPFS.

SYVN1 ubiquitinates FoxO1 to induce β-catenin nuclear translocation, PD-L1-mediated metastasis, and immune evasion of hepatocellular carcinoma

BACKGROUND

A high incidence of hepatocellular carcinoma (HCC), the most frequently diagnosed form of liver cancer, is observed in Africa and Asia. SYVN1 is upregulated in HCC; however, the biological roles of SYVN1 in immune evasion remain unclear.

METHODS

RT-qPCR and western blot were employed to detect the expression levels of SYVN1 and the key molecules in HCC cells and tissues. Flow cytometry was used to determine the proportion of T cells, and an ELISA assay was used to determine the amount of IFN-γ secreted. Cell viability was monitored by CCK-8 and colony formation assays. The metastatic properties of HCC cells were detected by Transwell assays. Bioinformatics analysis, ChIP, and luciferase assays were used to study the transcriptional regulation of PD-L1. Co-IP was used to detect direct interaction between SYVN1 and FoxO1, as well as the ubiquitination of FoxO1. The in vitro findings were validated in xenograft and lung metastasis models.

RESULTS

In HCC cells and tissues, SYVN1 was upregulated while FoxO1 was downregulated. SYVN1 knockdown or FoxO1 overexpression reduced PD-L1 expression, and inhibited immune evasion, cell growth, and metastasis in HCC cells. Mechanistically, FoxO1 regulated PD-L1 transcription in a β-catenin-independent or -dependent manner. Functional studies further showed that SYVN1 promoted immune evasion, cell proliferation, migration and invasion via facilitating ubiquitin-proteasome-dependent degradation of FoxO1. In vivo investigations showed that silencing of SYVN1 inhibited immune evasion and metastasis of HCC cells, possible via the FoxO1/PD-L1 axis.

CONCLUSION

SYVN1 regulates FoxO1 ubiquitination to stimulate β-catenin nuclear translocation and promotes PD-L1-mediated metastasis and immune evasion in HCC.

Accurate and Convenient Lung Cancer Diagnosis through Detection of Extracellular Vesicle Membrane Proteins via Förster Resonance Energy Transfer

Tumor-derived extracellular vesicles (EVs) are promising to monitor early stage cancer. Unfortunately, isolating and analyzing EVs from a patient's liquid biopsy are challenging. For this, we devised an EV membrane proteins detection system (EV-MPDS) based on Förster resonance energy transfer (FRET) signals between aptamer quantum dots and AIEgen dye, which eliminated the EV extraction and purification to conveniently diagnose lung cancer. In a cohort of 80 clinical samples, this system showed enhanced accuracy (100% versus 65%) and sensitivity (100% versus 55%) in cancer diagnosis as compared to the ELISA detection method. Improved accuracy of early screening (from 96.4% to 100%) was achieved by comprehensively profiling five biomarkers using a machine learning analysis system. FRET-based tumor EV-MPDS is thus an isolation-free, low-volume (1 μL), and highly accurate approach, providing the potential to aid lung cancer diagnosis and early screening.

The efficacy and safety of immune checkpoint inhibitors for patients with EGFR-mutated non-small cell lung cancer who progressed on EGFR tyrosine-kinase inhibitor therapy: A systematic review and network meta-analysis

BACKGROUND

Non-small cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR)-mutated who progressed on EGFR tyrosine-kinase inhibitor (EGFR-TKI) therapy have limited therapeutic options. There is still no consensus on the role of immune checkpoint inhibitors (ICIs) in NSCLC with EGFR mutations.

METHODS

We did a network meta-analysis (NMA) with a systematic literature search on PubMed, Embase, Web of Science, and The Cochrane Library. We included all phase II and III randomized controlled trials (RCTs), non-randomized controlled trials (Non-RCTs), and retrospective studies. Progression-free survival (PFS) and overall survival (OS) were assessed through hazard ratios (HR). Objective response rate (ORR) and adverse events (AEs) were assessed through odds ratio (OR) and relative risk (RR), respectively. R software was used to compare the outcomes of different treatments by Bayesian NMA.

FINDINGS

We identified 1835 published results and 17 studies were included ultimately. A total of 2085 patients were included and accepted the following six treatments: ICIs plus chemotherapy (ICIs+Chemo), chemotherapy (Chemo), ICIs monotherapy (ICIs), ICIs plus chemotherapy and antiangiogenic therapy (ICIs+Chemo+Antiangio), antiangiogenic therapy plus chemotherapy (Antiangio+Chemo), ICIs plus antiangiogenic therapy (ICIs+Antiangio). ICIs+Chemo+Antiangio was associated with longer PFS and OS, as well as higher ORR (surface under the cumulative ranking curve [SUCRA], 96%, 90%, 91%). ICIs conferred the safety profile in terms of any-grade AEs, grade greater than or equal to 3 AEs and any grade leading to treatment discontinuation occurred AEs (SUCRA, 99%, 68%, 94%).

INTERPRETATION

ICIs+Chemo+Antiangio brings the greatest survival benefit in NSCLC patients with EGFR mutations who progressed on EGFR-TKI therapy, even for whom with baseline brain metastases. Compared with chemotherapy, ICIs has a low incidence of AEs and a benefit in OS.

Elevated NOX4 promotes tumorigenesis and acquired EGFR-TKIs resistance via enhancing IL-8/PD-L1 signaling in NSCLC

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been widely used for human non-small-cell lung cancer (NSCLC) treatment. However, acquired resistance to EGFR-TKIs is the major barrier of treatment success, and new resistance mechanism remains to be elucidated. In this study, we found that elevated NADPH oxidase 4 (NOX4) expression was associated with acquired EGFR-TKIs resistance. Gefitinib is the first-generation FDA-approved EGFR-TKI, and osimertinib is the third-generation FDA-approved EGFR-TKI. We demonstrated that NOX4 knockdown in the EGFR-TKI resistant cells enabled the cells to become sensitive to gefitinib and osimertinib treatment, while forced expression of NOX4 in the sensitive parental cells was sufficient to induce resistance to gefitinib and osimertinib in the cells. To elucidate the mechanism of NOX4 upregulation in increasing TKIs resistance, we found that knockdown of NOX4 significantly down-regulated the expression of transcription factor YY1. YY1 bound directly to the promoter region of IL-8 to transcriptionally activate IL-8 expression. Interestingly, knockdown of NOX4 and IL-8 decreased programmed death ligand 1 (PD-L1) expression, which provide new insight on TKIs resistance and immune escape. We found that patients with higher NOX4 and IL-8 expression levels showed a shorter survival time compared to those with lower NOX4 and IL-8 expression levels in response to the anti-PD-L1 therapy. Knockdown of NOX4, YY1 or IL-8 alone inhibited angiogenesis and tumor growth. Furthermore, the combination of NOX4 inhibitor GKT137831 and gefitinib had synergistic effect to inhibit cell proliferation and tumor growth and to increase cellular apoptosis. These findings demonstrated that NOX4 and YY1 were essential for mediating the acquired EGFR-TKIs resistance. IL-8 and PD-L1 are two downstream targets of NOX4 to regulate TKIs resistance and immunotherapy. These molecules may be used as potential new biomarkers and therapeutic targets for overcoming TKIs resistance in the future.

Tumor-associated macrophages mediate resistance of EGFR-TKIs in non-small cell lung cancer: mechanisms and prospects

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the first-line standard treatment for advanced non-small cell lung cancer (NSCLC) with EGFR mutation. However, resistance to EGFR-TKIs is inevitable. Currently, most studies on the mechanism of EGFR-TKIs resistance mainly focus on the spontaneous resistance phenotype of NSCLC cells. Studies have shown that the tumor microenvironment (TME) also mediates EGFR-TKIs resistance in NSCLC. Tumor-associated macrophages (TAMs), one of the central immune cells in the TME of NSCLC, play an essential role in mediating EGFR-TKIs resistance. This study aims to comprehensively review the current mechanisms underlying TAM-mediated resistance to EGFR-TKIs and discuss the potential efficacy of combining EGFR-TKIs with targeted TAMs therapy. Combining EGFR-TKIs with TAMs targeting may improve the prognosis of NSCLC with EGFR mutation to some extent.

Influence of PD-L1 expression on the efficacy of EGFR-TKIs in EGFR-mutant non-small cell lung cancer

BACKGROUND

Evidence on the influence of programmed death-ligand 1 (PD-L1) expression on the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC) patients is at variance.

METHODS

A single-center retrospective study was conducted to evaluate the influence of PD-L1 expression on the efficacy of EGFR-TKIs for NSCLC patients with EGFR mutation. Clinical information was retrieved from electronic medical records. The patients were divided into three subgroups according to PD-L1 expression level: PD-L1 < 1% (negative), PD-L1 1%-49% and PD-L1 ≥ 50%. The clinicopathological features, overall response rate (ORR), progression-free survival (PFS) and comutation information were collected and compared between the three subgroups.

RESULTS

A total of 117 patients were included. For PD-L1 < 1%, PD-L1 1%-49% and PD-L1 ≥ 50% group, there were 39 (33.3%), 51 (43.5%) and 27 (23.0%) patients respectively, and the ORR was 43.2%, 64.0%, and 51.9%, respectively (p = 0.162), and the median progression-free survival (mPFS) was 22.0 months (95% CI: 14.0-29.9 months), 15.4 months (95% CI: 8.9-21.8 months) and 13.0 months (95% CI: 10.6-15.3 months), respectively (log-rank, p = 0.01). The mPFS was negatively correlated with PD-L1 expression level (r = -0.264, p = 0.041) and PD-L1 expression was an independent risk factor for worse PFS of EGFR-TKIs in multivariate Cox regression. Patients with concurrent TP53 mutation had shorter PFS (p = 0.039) and the patients harboring both mutant TP53 and positive PD-L1 had the shortest PFS (p = 0.006).

CONCLUSIONS

The efficacy of EGFR-TKIs was influenced by the baseline PD-L1 expression. Higher PD-L1 expression was associated with shorter PFS. The combined indicators of TP53 and PD-L1 identified subgroups showing divergent benefits from EGFR-TKIs.

Rechallenge with EGFR-TKI after failure of immunotherapy is considered an effective treatment for advanced lung adenocarcinoma patients with EGFR exon 19 deletion: a case report

In advanced lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutation, epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have an excellent and long-lasting therapeutic response; however, virtually all patients eventually develop drug resistance and experience disease progression. The use of immunotherapy after EGFR-TKIs may be a successful therapeutic option for individuals who are resistant to them. It is still unclear if EGFR-TKIs can be administered again after immunotherapy has failed. We describe a case of a 37-year-old woman who was found to have T4N3M1a stage IVa lung adenocarcinoma. Amplification refractory mutation system PCR (ARMS-PCR) genetic testing suggested EGFR exon 19 deletion. The patient was initially treated with a regimen of icotinib (125  mg tid) combined with anlotinib (8  mg qd d1-d14) with an optimal efficacy rating of partial response (PR) and was granted a PFS of 7  months. In second-line treatment, the patient received three cycles of a KN046 (KN046 is a bispecific antibody inhibitor of PD-L1 and CTLA-4) 295  mg d1, pemetrexed 800 mg d1, plus carboplatin 750  mg d1 regimen, with an optimal efficacy rating of stable disease (SD) on CT. The third-line therapy was chosen to be afatinib with docetaxel, and the patient was evaluated for PR on CT. Up to 15 August 2022, the patient had a progression free survival (PFS) of 14 months. The successful treatment of this patient is a reminder that EGFR-TKI rechallenge in EGFR exon 19 deletion patients with EGFR-TKI resistance, in which immunotherapy has failed, may be effective.

Stratification of non-small cell lung adenocarcinoma patients with EGFR actionable mutations based on drug-resistant stem cell genes

EGFR-TKIs were used in NSCLC patients with actionable EGFR mutations and prolong prognosis. However, most patients treated with EGFR-TKIs developed resistance within around one year. This suggests that residual EGFR-TKIs resistant cells may eventually lead to relapse. Predicting resistance risk in patients will facilitate individualized management. Herein, we built an EGFR-TKIs resistance prediction (R-index) model and validate in cell line, mice, and cohort. We found significantly higher R-index value in resistant cell lines, mice models and relapsed patients. Patients with an elevated R-index had significantly shorter relapse time. We also found that the glycolysis pathway and the KRAS upregulation pathway were related to EGFR-TKIs resistance. MDSC is a significant immunosuppression factor in the resistant microenvironment. Our model provides an executable method for assessing patient resistance status based on transcriptional reprogramming and may contribute to the clinical translation of patient individual management and the study of unclear resistance mechanisms.

Modulation of tumor immune microenvironment by TAS-115, a multi-receptor tyrosine kinase inhibitor, promotes antitumor immunity and contributes anti-PD-1 antibody therapy

TAS-115 is an oral multi-receptor tyrosine kinase inhibitor that strongly inhibits kinases implicated in antitumor immunity, such as colony stimulating factor 1 receptor and vascular endothelial growth factor receptor. Because these kinases are associated with the modulation of immune pathways, we investigated the immunomodulatory activity of TAS-115. An in vitro cytokine assay revealed that TAS-115 upregulated interferon γ (IFNγ) and interleukin-2 secretion by T cells, suggesting that TAS-115 activated T cells. Gene expression analysis suggested that TAS-115 promoted M1 macrophage differentiation. In in vivo experiments, although TAS-115 exerted a moderate antitumor effect in the MC38 mouse colorectal cancer model under immunodeficient conditions, this effect was enhanced under immunocompetent conditions. Furthermore, combination of TAS-115 and anti-PD-1 antibody exhibited greater antitumor activity than either treatment alone. Flow cytometry analysis showed the increase in IFNγ- and granzyme B (Gzmb)-secreting tumor-infiltrating T cells by TAS-115 treatment. The combination treatment further increased the percentage of Gzmb+CD8+ T cells and decreased the percentage of macrophages compared with either treatment alone. These results highlight the potential therapeutic effect of TAS-115 in combination with PD-1 blockade, mediated via activation of antitumor immunity by TAS-115.

The Immunosuppressive Roles of PD-L1 during Influenza A Virus Infection

The clinical benefits of targeting programmed death-ligand 1 (PD-L1) in various cancers represent a strategy for the treatment of immunosuppressive diseases. Here, it was demonstrated that the expression levels of PD-L1 in cells were greatly upregulated in response to H1N1 influenza A virus (IAV) infection. Overexpression of PD-L1 promoted viral replication and downregulated type-I and type-III interferons and interferon-stimulated genes. Moreover, the association between PD-L1 and Src homology region-2, containing protein tyrosine phosphatase (SHP2), during IAV/H1N1 infection was analyzed by employing the SHP2 inhibitor (SHP099), siSHP2, and pNL-SHP2. The results showed that the expressions of PD-L1 mRNA and protein were decreased under SHP099 or siSHP2 treatment, whereas the cells overexpressing SHP2 exhibited the opposite effects. Additionally, the effects of PD-L1 on the expression of p-ERK and p-SHP2 were investigated in PD-L1-overexpressed cells following WSN or PR8 infection, determining that the PD-L1 overexpression led to the decreased expression of p-SHP2 and p-ERK induced by WSN or PR8 infection. Taken together, these data reveal that PD-L1 could play an important role in immunosuppression during IAV/H1N1 infection; thus, it may serve as a promising therapeutic target for development of novel anti-IAV drugs.

Silencing of RAB42 down-regulated PD-L1 expression to inhibit the immune escape of hepatocellular carcinoma cells through inhibiting the E2F signaling pathway

OBJECTIVE

To investigate the mechanistic role of RAB42 and corresponding regulatory path in hepatocellular carcinoma (HCC).

METHODS

The expression of RAB42 in HCC tissue was checked by RT-qPCR and immunohistochemical staining assay. Cell proliferation was checked by colony formation and CCK-8 assay. Cell apoptosis and cycle distribution were analyzed with flow cytometry. The relevance of RAB42 and PD-L1 was analyzed from TCGA database. The binding of E2F1 to PD-L1 was detected by JASPAR database, luciferase and ChIP assay. The expression of PD-L1, cell apoptosis- and E2F pathway-related proteins were checked by western blotting.

RESULTS

RAB42 was highly expressed in HCC tissue. RAB42 silencing could inhibit proliferation and induce G1 phase arrest and apoptosis of HCC cells. TCGA database disclosed that PD-L1 was highly associated with RAB42 expression. Silencing of RAB42 could retard PD-L1 expression in HCC cells. GSEA analysis showed RAB42 could activate E2F signaling pathway. Silencing of RAB42 could observably weaken the expression of E2F1, CDK1 and CDC20 in HCC cells. JASPAR database predicted the binding site between E2F1 and PD-L1, and E2F1 overexpression could promote PD-L1 expression. Overexpression of E2F1 could reverse the biological function of RAB42 silencing in HCC cells.

CONCLUSION

Silencing of RAB42 could down-regulate PD-L1 expression to inhibit immune escape through inhibiting E2F signaling pathway in HCC cells. RAB42 may become a novel clinical diagnostic and therapy marker for HCC.

Challenges of EGFR-TKIs in NSCLC and the potential role of herbs and active compounds: From mechanism to clinical practice

Epidermal growth factor receptor (EGFR) mutations are the most common oncogenic driver in non-small cell lung cancer (NSCLC). Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are widely used in the treatment of lung cancer, especially in the first-line treatment of advanced NSCLC, and EGFR-TKIs monotherapy has achieved better efficacy and tolerability compared with standard chemotherapy. However, acquired resistance to EGFR-TKIs and associated adverse events pose a significant obstacle to targeted lung cancer therapy. Therefore, there is an urgent need to seek effective interventions to overcome these limitations. Natural medicines have shown potential therapeutic advantages in reversing acquired resistance to EGFR-TKIs and reducing adverse events, bringing new options and directions for EGFR-TKIs combination therapy. In this paper, we systematically demonstrated the resistance mechanism of EGFR-TKIs, the clinical strategy of each generation of EGFR-TKIs in the synergistic treatment of NSCLC, the treatment-related adverse events of EGFR-TKIs, and the potential role of traditional Chinese medicine in overcoming the resistance and adverse reactions of EGFR-TKIs. Herbs and active compounds have the potential to act synergistically through multiple pathways and multiple mechanisms of overall regulation, combined with targeted therapy, and are expected to be an innovative model for NSCLC treatment.

Safety and clinical activity of atezolizumab plus erlotinib in patients with non-small-cell lung cancer

BACKGROUND

Acquired resistance limits long-term epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) efficacy in patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC) in whom anti-programmed death-ligand 1 (PD-L1) efficacy is also limited. We hypothesized that combining atezolizumab with erlotinib could enhance antitumor immunity and extend efficacy in these patients.

PATIENTS AND METHODS

This open-label phase Ib trial was conducted in adults aged ≥18 years who had advanced, unresectable NSCLC. Stage 1 (safety evaluation) enrolled EGFR TKI-naive patients regardless of EGFR status. Stage 2 (expansion) enrolled patients with EGFR-mutant NSCLC treated with ≤1 prior non-EGFR TKI therapy. Patients received 150 mg erlotinib orally once daily. After a 7-day erlotinib run-in, atezolizumab 1200 mg was administered intravenously every 3 weeks. The primary endpoint was the safety and tolerability of the combination in all patients; secondary endpoints included antitumor activity per RECIST 1.1 in stage 2 patients.

RESULTS

At the data cut-off on 7 May 2020, 28 patients (8 in stage 1, 20 in stage 2) were assessable for safety. No dose-limiting toxicities or grade 4 or 5 treatment-related adverse events occurred. Grade 3 treatment-related adverse events occurred in 46% of patients; the most common were increased alanine aminotransferase, diarrhea, pyrexia, and rash (each in 7% of patients). Serious adverse events occurred in 50% of patients. Pneumonitis (grade 1) was reported in a single patient (4%). The objective response rate was 75% [95% confidence interval (CI) 50.9% to 91.3%]), median response duration was 18.9 months (95% CI 9.5-40.5 months), median progression-free survival was 15.4 months (95% CI 8.4-39.0 months), and median overall survival was not estimable (NE) (95% CI 34.6-NE).

CONCLUSIONS

Atezolizumab combined with erlotinib demonstrated a tolerable safety profile and encouraging, durable clinical activity in patients with advanced EGFR mutation-positive NSCLC.

Targeting the Epidermal Growth Factor Receptor with Molecular Degraders: State-of-the-Art and Future Opportunities

Epidermal growth factor receptor (EGFR) is an oncogenic drug target and plays a critical role in several cellular functions including cancer cell growth, survival, proliferation, differentiation, and motility. Several small-molecule tyrosine kinase inhibitors (TKIs) and monoclonal antibodies (mAbs) have been approved for targeting intracellular and extracellular domains of EGFR, respectively. However, cancer heterogeneity, mutations in the catalytic domain of EGFR, and persistent drug resistance limited their use. Different novel modalities are gaining a position in the limelight of anti-EGFR therapeutics to overcome such limitations. The current perspective reflects upon newer modalities, importantly the molecular degraders such as PROTACs, LYTACs, AUTECs, and ATTECs, etc., beginning with a snapshot of traditional and existing anti-EGFR therapies including small molecule inhibitors, mAbs, and antibody drug conjugates (ADCs). Further, a special emphasis has been made on the design, synthesis, successful applications, state-of-the-art, and emerging future opportunities of each discussed modality.

Changes of tumor microenvironment in non-small cell lung cancer after TKI treatments

Non-small cell lung cancer (NSCLC) is the most common lung cancer diagnosis, among which epidermal growth factor receptor (EGFR), Kirsten rat sarcoma (KRAS), and anaplastic lymphoma kinase (ALK) mutations are the common genetic drivers. Their relative tyrosine kinase inhibitors (TKIs) have shown a better response for oncogene-driven NSCLC than chemotherapy. However, the development of resistance is inevitable following the treatments, which need a new strategy urgently. Although immunotherapy, a hot topic for cancer therapy, has shown an excellent response for other cancers, few responses for oncogene-driven NSCLC have been presented from the existing evidence, including clinical studies. Recently, the tumor microenvironment (TME) is increasingly thought to be a key parameter for the efficacy of cancer treatment such as targeted therapy or immunotherapy, while evidence has also shown that the TME could be affected by multi-factors, such as TKIs. Here, we discuss changes in the TME in NSCLC after TKI treatments, especially for EGFR-TKIs, to offer information for a new therapy of oncogene-driven NSCLC.

IL-33/ST2 signaling promotes constitutive and inductive PD-L1 expression and immune escape in oral squamous cell carcinoma

BACKGROUND

Loss-of-function of PD-L1 induces therapy resistance of anti-PD-1/L1 therapy, and the complex regulatory mechanisms are not completely understood. We previously reported that stroma-derived interleukin-33 (IL-33) promoted the progression of oral squamous cell carcinoma (OSCC). We here focused on the immune-regulation role of IL-33 and its receptor ST2 signaling in PD-L1-positive OSCC patients.

METHODS

Activated T cells in in situ and peripheral blood were analyzed by IL-33/ST3 expression. Knockdown or overexpression of ST2 combined with IL-33/IFN-γ stimulation were performed to determine PD-L1 expression and PD-L1-dependent immune escape in OSCC/human T cells co-culture system, and OSCC orthotopic model based on humanized mouse with immune reconstitution and C57BL/6 mice models.

RESULTS

High IL-33/ST2 correlated with less activated T cells infiltration in situ and peripheral blood. Knockdown of ST2 down-regulated constitutive PD-L1 expression, whereas ST2 also promoted IL-33-induced PD-L1 Mechanistically, IL-33/ST2 activated JAK2/STAT3 pathway to directly promoted PD-L1 expression, and also activated MyD88/NF-κB signaling to up-regulate IFN-γ receptor (IFN-γR), which indirectly strengthen IFN-γ-induced PD-L1. Furthermore, ST2 is required for PD-L1-mediated immune tolerance in vitro and in vivo. ST2high OSCC patients have more PD-L1 and IFN-γR level in situ.

CONCLUSIONS

IL-33/ST2 signaling enhanced PD-L1-mediated immune escape, ST2high OSCC patients might benefit from anti-PD-1/L1 therapy.

The efficacy and safety of PD-1 inhibitors for EGFR-mutant non-small cell lung cancer after tyrosine kinase inhibitor failure: a retrospective real-world cohort study

Background

Acquired drug resistance to various tyrosine kinase inhibitor (TKI) inevitably develops in almost all epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). The present study aimed to evaluate the efficacy and safety of programmed cell death protein 1 (PD-1) inhibitors for such patients after TKI failure and further explore the subpopulation that exhibited the most benefit.

Methods

A total of 102 EGFR-mutant NSCLC patients who received PD-1 inhibitors after developing resistance to EGFR-TKIs were included in the study. The primary endpoints were progression-free survival (PFS) and grade 3-5 adverse events (AEs), while the secondary endpoints were overall survival (OS), disease control rate (DCR) and subgroup analyses.

Results

All the 102 patients received 2 or more lines of immunotherapy. The overall median PFS was 4.95 months [95% confidence interval (CI): 3.91-5.89 months]. The EGFR^L858R group showed a significant PFS benefit compared with the EGFR^D19 group (6.4 vs. 3.5 months, P=0.002), and likewise for the DCR between the 2 groups (EGFR^L858R vs. EGFR^D19 group: 84.3% vs. 66.7%, P=0.049). In addition, median PFS in the EGFR^T790M-negative group (6.47 months) was significantly longer than the EGFR^T790M-positive group (3.20 months) (P=0.003). The overall OS was 10.70 months (95% CI: 8.92-12.48 months), without a prognostic factor. There was a trend towards improved PFS and OS with combination therapy. The incidence of grade 3-5 treatment-related AEs was 19.6%, while the incidence of grade 3-5 immune-related AEs (irAEs) was 6.9%. Treatment-related AEs were similar in different mutation subtypes. The incidence of grade 3-5 irAEs was higher in the EGFR^D19 group (10.3%) compared with the EGFR^L858R group (5.9%), and likewise in the EGFR^T790M-negative group (10%) compared with the EGFR^T790M-positive group (2.6%).

Conclusions

After EGFR-TKI failure, PD-1 inhibitors provided better survival in advanced NSCLC for the EGFR^L858R subgroup and EGFR^T790M-negative subgroup, and there was a trend towards improved outcomes with combination therapy. In addition, toxicity was well tolerated. Our real-world study increased the population size and obtained a similar survival outcome compared from clinical trials.

Pharmacological tumor PDL1 depletion with chlorambucil treats ovarian cancer and melanoma: improves antitumor immunity and renders anti-PDL1-resistant tumors anti-PDL1-sensitive through NK cell effects

BACKGROUND

Tumor intracellular programmed cell death ligand-1 (PDL1) mediates pathologic signals that regulate clinical treatment responses distinctly from surface-expressed PDL1 targeted by αPDL1 immune checkpoint blockade antibodies.

METHODS

We performed a drug screen for tumor cell PDL1 depleting drugs that identified Food and Drug Administration (FDA)-approved chlorambucil and also 9-[2-(phosphonomethoxy)ethyl] guanine. We used in vitro and in vivo assays to evaluate treatment and signaling effects of pharmacological tumor PDL1 depletion focused on chlorambucil as FDA approved, alone or plus αPDL1.

RESULTS

PDL1-expressing mouse and human ovarian cancer lines and mouse melanoma were more sensitive to chlorambucil-mediated proliferation inhibition in vitro versus corresponding genetically PDL1-depleted lines. Orthotopic peritoneal PDL1-expressing ID8agg ovarian cancer and subcutaneous B16 melanoma tumors were more chlorambucil-sensitive in vivo versus corresponding genetically PDL1-depleted tumors. Chlorambucil enhanced αPDL1 efficacy in tumors otherwise αPDL1-refractory, and improved antitumor immunity and treatment efficacy in a natural killer cell-dependent manner alone and plus αPDL1. Chlorambucil-mediated PDL1 depletion was relatively tumor-cell selective in vivo, and treatment efficacy was preserved in PDL1KO hosts, demonstrating tumor PDL1-specific treatment effects. Chlorambucil induced PDL1-dependent immunogenic tumor cell death which could help explain immune contributions. Chlorambucil-mediated PDL1 reduction mechanisms were tumor cell-type-specific and involved transcriptional or post-translational mechanisms, including promoting PDL1 ubiquitination through the GSK3β/β-TRCP pathway. Chlorambucil-mediated tumor cell PDL1 depletion also phenocopied genetic PDL1 depletion in reducing tumor cell mTORC1 activation and tumor initiating cell content, and in augmenting autophagy, suggesting additional treatment potential.

CONCLUSIONS

Pharmacological tumor PDL1 depletion with chlorambucil targets tumor-intrinsic PDL1 signaling that mediates treatment resistance, especially in αPDL1-resistant tumors, generates PDL1-dependent tumor immunogenicity and inhibits tumor growth in immune-dependent and independent manners. It could improve treatment efficacy of selected agents in otherwise treatment-refractory, including αPDL1-refractory cancers, and is rapidly clinically translatable.

Immunotherapy-based therapy as a promising treatment for EGFR-mutant advanced non-small cell lung cancer patients after EGFR-TKI resistance

INTRODUCTION

Traditionally, epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) has been regarded as a cold tumor based on the immunosuppressive tumor immune microenvironment (TIME). However, recent studies have found that EGFR-tyrosine kinase inhibitor (EGFR-TKI) treatment could shift host immunity from immunosuppressive to immunosupportive TIME, which has renewed hopes of immunotherapy.

AREAS COVERED

In this review, we highlight five main immunotherapy-based therapies for patients after EGFR-TKI failure, including safety and efficacy data from prospective and retrospective clinical studies.

EXPERT OPINION

The efficacy of immunotherapy alone is extremely limited. Immunotherapy plus chemotherapy show an ORR of 29.5%-59.3% and an mPFS of about 7 months. There is still scarce evidence for immunotherapy plus antiangiogenesis therapy. A combination of immunotherapy with EGFR-TKIs exhibits higher treatment-related adverse events and lower clinical outcomes compared to EGFR-TKI alone. Importantly, immunotherapy plus antiangiogenesis and chemotherapy achieves an mPFS of 6.9-10.2 months. In general, the strategy of combining immunotherapy with chemotherapy and/or an antiangiogenic drug is a novel and promising method for treating advanced NSCLC after EGFR-TKI failure. Therefore, the dominant population of EGFR-TKI resistant patients were characterized by EGFR uncommon mutation, EGFR L858R mutation, PD-L1 ≥ 50%, prior antiangiogenic drugs, and negative T790 M mutation for immunotherapy-based therapy.

Non-invasive plasma testing for CD274 UTR structural variations by next-generation sequencing in cancer

Immunotherapy is now the main choice of systemic therapy for many cancer patients, while current biomarkers for tumor immunotherapy may be limited by the accessibility of patient tumor tissue or tumor neoplastic content. Rare mutation in the 5' and 3'-untranslated region (UTR) of CD274 gene (Protein name: PD-L1) has been recently reported in hematologic and solid tumors as a potential biomarker for assessing efficacy during immunotherapy. However, multi-omics analysis for CD274 UTR region, especially circulating tumor DNA (ctDNA), have been little explored in the pan-cancer perspective. We developed a cSMART2.0 technology featured with higher capture efficiency and homogeneity to detect this rare structural variant in 2249 Chinese patients' cohort with multiple cancers. An incidence of 0.36% was detected in this cohort, consistent with TCGA (The Cancer Genome Atlas), while the prevalence of SV in CD274 UTR region in liver and breast cancer were significantly higher than TCGA. The liquid biopsy result from ctDNA was 100% concordance with gDNA result getting from tumor tissue detection, and further validated by immunohistochemistry (IHC) and multiplex immunofluorescence (mIF) experiments. Patients carrying this SV in CD274 UTR region without driver gene mutation responded to immune checkpoint inhibitors (ICIs). This study proves that rare structural variants in CD274 UTR region exist in various cancer in Chinese population for the first time, which can induce immune escape and be used for prediction of response to ICIs. Liquid biopsy based cSMART 2.0 technology could offer more sensitive and accurate detection to navigate potential ICIs patients and to benefit patients with advanced disease when tissue samples are not available.

MMP11 is associated with the immune response and immune microenvironment in EGFR-mutant lung adenocarcinoma

Background

High expression of matrix metalloproteinase-11 (MMP11) is associated with various tumors and immune microenvironments. Conversely, poor response to immunotherapy in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma (LUAD) patients is closely related to the characteristics of immune microenvironment.

Methods

The Cancer Genome Atlas (TCGA)-LUAD database and our gathered clinical LUAD samples were used to examine the relationship between MMP11 expression and EGFR mutation. Then the correlation between MMP11 and immune response and the difference of immune cell infiltration in different groups were analyzed. Compared the differences in the immune microenvironment between the MMP11-positive and MMP11-negative expression groups using immunohistochemistry (IHC) and multiplex immunohistochemistry.

Results

The expression of MMP11 in samples with exon 19 deletions, exon 21 L858R or de novo exon 20 T790M mutations was higher than wild type, but there was no difference between the samples with uncommon mutation and the wild-type. The high MMP11 expression group had a higher Tumor Immune Dysfunction and Exclusion (TIDE) score. Pathways associated with enrichment in the extracellular matrix (ECM) were the main biological functions of differential genes between the high and low MMP11 groups. The IHC score of MMP11 in the EGFR-mutant group was higher than in the EGFR-wild group. In TCGA-LUAD, the high MMP11 group had a lower proportion of T cell CD8+ and NK cells activated. In the clinical samples, the infiltration levels of T cell CD8+ and NK cells in the tumor parenchyma of EGFR-mutant LUAD was lower in the MMP11-positive than in the MMP11-negative group. The expression levels of tumor cell PD-L1 were higher in the MMP11-positive expression group than in the MMP11-negative expression group, and the proportion of PD1+CD8+ T cells infiltrated was reduced in the MMP11-positive group compared to the MMP11-negative group.

Conclusions

High expression of MMP11 was associated with EGFR mutations. Patients with EGFR-mutant LUAD with high expression of MMP11 responded poorly to immunotherapy, and the percentage of T cell CD8+ and NK cells in immune cell infiltration was lower in MMP11. Consequently, MMP11 is related to the immunological microenvironment of EGFR-mutant lung adenocarcinoma, which may be a predictor of possible immunotherapeutic response.

Research progress of abnormal lactate metabolism and lactate modification in immunotherapy of hepatocellular carcinoma

Tumors meet their energy, biosynthesis, and redox demands through metabolic reprogramming. This metabolic abnormality results in elevated levels of metabolites, particularly lactate, in the tumor microenvironment. Immune cell reprogramming and cellular plasticity mediated by lactate and lactylation increase immunosuppression in the tumor microenvironment and are emerging as key factors in regulating tumor development, metastasis, and the effectiveness of immunotherapies such as immune checkpoint inhibitors. Reprogramming of glucose metabolism and the "Warburg effect" in hepatocellular carcinoma (HCC) lead to the massive production and accumulation of lactate, so lactate modification in tumor tissue is likely to be abnormal as well. This article reviews the immune regulation of abnormal lactate metabolism and lactate modification in hepatocellular carcinoma and the therapeutic strategy of targeting lactate-immunotherapy, which will help to better guide the medication and treatment of patients with hepatocellular carcinoma.

Immunotherapy resistance in non-small-cell lung cancer: From mechanism to clinical strategies

The high primary resistance incidence and unavoidable secondary resistance are the major clinical obstacle to lasting long-term benefits in Non-small-cell lung cancer (NSCLC) patients treated with immunotherapy. The mechanisms of immunotherapy resistance in NSCLC are complex, mainly involving tumor cells and tumor microenvironment (TME) infiltrating immune cells, including TAMs, B cells, NK cells, and T cells. The selection of clinical strategies for NSCLC progression after immunotherapy resistance should depend on the progressive mode. The progression pattern of NSCLC patients after immunotherapy resistance can be divided into oligo-progression and systemic/multiple progression, which should be considered for further treatment selection. In the future, it needs to explore how to optimize the combined therapy and explore strategies to reprogram infiltrating immune cells under various genetic backgrounds of tumor cells and timely reshape TME during antitumor treatments.