PD-1/PD-L1 pathway in non-small-cell lung cancer and its relation with EGFR mutation

Assessing the Clinical Relevance of Soluble PD-1 and PD-L1: A Multi-Cohort Study Across Diverse Tumor Types and Prognostic Implications

Background/Objectives: Immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway have revolutionized cancer immunotherapy, however the clinical relevance of their soluble forms (sPD-1 and sPD-L1) remains less studied. Soluble PD-1 and PD-L1 have been implicated in tumor progression, prognosis, and treatment response across various malignancies. This study aims to provide a comprehensive analysis of sPD-1 and sPD-L1 levels in serum across diverse tumor types, including rare malignancies, and to evaluate their associations with clinicopathological characteristics and prognostic significance. Methods: In this study we analyzed sPD-1 and sPD-L1 levels in serum samples from 675 cancer patients representing a range of malignancies, including ovarian cancer, breast cancer, gastric cancer, colorectal cancer, renal cell carcinoma, and bone tumors. sPD-1 and sPD-L1 concentrations were measured using ELISA. Statistical analyses were performed to evaluate associations between soluble marker concentrations and clinicopathological factors, including tumor stage, size, histological subtype, and survival outcomes. Results: Elevated sPD-L1 levels were observed in several tumor types, including ovarian cancer, renal cell carcinoma, and gastric cancer, where they were associated with features of advanced disease, such as tumor size, stage, and metastases. In contrast, sPD-1 levels showed limited associations, with significant findings solely in gastric cancer and bone tumors, where levels correlated with histological subtype and differentiation. Prognostic analyses identified sPD-L1 as a marker of poor survival outcomes in ovarian cancer and bone tumors, while sPD-1 displayed no consistent prognostic significance. Conclusions: This study identifies the potential of sPD-L1 as a biomarker for tumor progression and prognosis across multiple malignancies. In contrast, sPD-1 showed limited clinical relevance, suggesting the importance of further investigation. These findings contribute to our understanding of soluble immune checkpoint proteins and their integration into personalized oncology strategies.

Advancements in immunotherapy for colorectal cancer treatment: a comprehensive review of strategies, challenges, and future prospective

PURPOSE

Colorectal cancer (CRC) remains one of the leading causes of cancer-related mortality worldwide. Metastatic colorectal cancer (mCRC) continues to present significant challenges, particularly in patients with proficient mismatch repair/microsatellite stable (pMMR/MSS) tumors. This narrative review aims to provide recent developments in immunotherapy for CRC treatment, focusing on its efficacy and challenges.

METHODS

This review discussed the various immunotherapeutic strategies for CRC treatment, including immune checkpoint inhibitors (ICIs) targeting PD-1 and PD-L1, combination therapies involving ICIs with other modalities, chimeric antigen receptor T-cell (CAR-T) cell therapy, and cancer vaccines. The role of the tumor microenvironment and immune evasion mechanisms was also explored to understand their impact on the effectiveness of these therapies.

RESULTS

This review provides a comprehensive update of recent advancements in immunotherapy for CRC, highlighting the potential of various immunotherapeutic approaches, including immune checkpoint inhibitors, combination therapies, CAR-T therapy, and vaccination strategies. The results of checkpoint inhibitors, particularly in patients with MSI-H/dMMR tumors, which have significant improvements in survival rates have been observed. Furthermore, this review also addresses the challenges faced in treating pMMR/MSS CRC, which remains resistant to immunotherapy.

CONCLUSION

Immunotherapy plays a significant role in the treatment of CRC, particularly in patients with MSI-H/dMMR tumors. However, many challenges remain, especially in treating pMMR/MSS CRC. This review discussed the need for further research into combination therapies, biomarker development, CAR-T cell therapy, and a deeper understanding of immune evasion mechanisms for CRC treatment.

Role of PD-1/PD-L1 signaling axis in oncogenesis and its targeting by bioactive natural compounds for cancer immunotherapy

Cancer is a global health problem and one of the leading causes of mortality. Immune checkpoint inhibitors have revolutionized the field of oncology, emerging as a powerful treatment strategy. A key pathway that has garnered considerable attention is programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1). The interaction between PD-L1 expressed on tumor cells and PD-1 reduces the innate immune response and thus compromises the capability of the body's immune system. Furthermore, it controls the phenotype and functionality of innate and adaptive immune components. A range of monoclonal antibodies, including avelumab, atezolizumab, camrelizumab, dostarlimab, durvalumab, sinitilimab, toripalimab, and zimberelimab, have been developed for targeting the interaction between PD-1 and PD-L1. These agents can induce a broad spectrum of autoimmune-like complications that may affect any organ system. Recent studies have focused on the effect of various natural compounds that inhibit immune checkpoints. This could contribute to the existing arsenal of anticancer drugs. Several bioactive natural agents have been shown to affect the PD-1/PD-L1 signaling axis, promoting tumor cell apoptosis, influencing cell proliferation, and eventually leading to tumor cell death and inhibiting cancer progression. However, there is a substantial knowledge gap regarding the role of different natural compounds targeting PD-1 in the context of cancer. Hence, this review aims to provide a common connection between PD-1/PD-L1 blockade and the anticancer effects of distinct natural molecules. Moreover, the primary focus will be on the underlying mechanism of action as well as the clinical efficacy of bioactive molecules. Current challenges along with the scope of future research directions targeting PD-1/PD-L1 interactions through natural substances are also discussed.

New expression of PD-L1 on activated CD4+ T cells opens up new opportunities for cell interactions and signaling

Surface expression of programmed death-ligand 1 (PD-L1) is mainly observed on antigen presenting cells (APC) such as monocytes or dendritic cells (DCs). Our results showing a high expression of PD-L1 on human naïve CD4+ effector T-cells (TEFFs) and CD4+ regulatory T cells (TREGs) after activation with human DCs, allow us to propose a new role for PD-L1 and its ligands and their potential impact on new signaling pathways. Indeed, expression of PD-L1 on activated CD4+T cells could allow cis interaction with its ligands such as PD-1 and CD80, thus disrupting interactions with other signaling receptors, such as cytotoxic T-lymphocyte antigen-4 (CTLA-4) or CD28, which interact with CD80. The ability to compete with hypothetical configuration modifications that may cause a change in affinity/avidity for the trans and cis interactions between these proteins expressed on T cells and/or DCs is discussed. As the study of cancer is strongly influenced by the role of the PD-L1/PD-1 pathway and CD4+T cells, new interactions, cis and/or trans, between TEFFs, TREGs and tumor cells are also proposed. The presence of PD-L1 on activated CD4+ T cells could influence the quality of the cytotoxic T lymphocyte response during priming to provide other help signals.

GSG2 promotes progression of human endometrial cancer by regulating PD-1/PD-L1 expression via PI3K-AKT pathway

Cell cycle dysregulation leading to uncontrolled growth is a primary characteristic of malignancy. GSG2, a mitosis-related kinase, affects the normal cell cycle by interfering with the normal dissociation of centromere cohesion, and its overexpression has been shown to play an important role in cancer cells. Here, we investigated the function of GSG2 as a tumor promoter in endometrial carcinoma and its relationship with the immunological microenvironment. We used immunohistochemistry to identify a correlation between the development and prognosis of GSG2 and endometrial cancer. Cell and animal experiments confirmed that GSG2 has a protumorigenic phenotype in endometrial cancer cell lines. Furthermore, using GeneChip analysis and a tumor-immune coculture model, we observed a link between GSG2 expression and the composition of the immune microenvironment. Therefore, we concluded that the activation of the PI3K/AKT pathway by GSG2 may impact DNA repair, disrupt the cell cycle, and regulate the immune response, all of which could increase the ability of EC cells to proliferate malignantly. Consequently, it is anticipated that GSG2 will be a viable therapeutic target in endometrial carcinoma.

The viral etiology of EBV-associated gastric cancers contributes to their unique pathology, clinical outcomes, treatment responses and immune landscape

Epstein-Barr virus (EBV) is a pathogen known to cause a number of malignancies, often taking years for them to develop after primary infection. EBV-associated gastric cancer (EBVaGC) is one such malignancy, and is an immunologically, molecularly and pathologically distinct entity from EBV-negative gastric cancer (EBVnGC). In comparison with EBVnGCs, EBVaGCs overexpress a number of immune regulatory genes to help form an immunosuppressive tumor microenvironment (TME), have improved prognosis, and overall have an "immune-hot" phenotype. This review provides an overview of the histopathology, clinical features and clinical outcomes of EBVaGCs. We also summarize the differences between the TMEs of EBVaGCs and EBVnGCs, which includes significant differences in cell composition and immune infiltration. A list of available EBVaGC and EBVnGC gene expression datasets and computational tools are also provided within this review. Finally, an overview is provided of the various chemo- and immuno-therapeutics available in treating gastric cancers (GCs), with a focus on EBVaGCs.

Structure-Guided Discovery of PD-1/PD-L1 Interaction Inhibitors: Peptide Design, Screening, and Optimization via Computation-Aided Phage Display Engineering

Cancer immunotherapy harnesses the immune system to combat tumors and has emerged as a major cancer treatment modality. The PD-1/PD-L1 immune checkpoint modulates interactions between tumor cells and T cells and has been extensively targeted in cancer immunotherapy. However, the monoclonal antibodies known to target this immune checkpoint have considerable side effects, and novel PD-1/PD-L1 inhibitors are therefore required. Herein, a peptide inhibitor to disrupt PD-1/PD-L1 interactions was designed through structure-driven phage display engineering coupled to computational modification and optimization. BetaPb, a novel peptide library constructed by using the known structure of PD-1/PD-L, was used to develop inhibitors against the immune checkpoint, and specific peptides with high affinity toward PD-1 were screened through enzyme-linked immunosorbent assays, homogeneous time-resolved fluorescence, and biolayer interferometry. A potential inhibitor, B8, was preliminarily screened through biopanning. The binding affinity of B8 toward PD-1 was confirmed through computation-aided optimization. Assessment of B8 variants (B8.1, B8.2, B8.3, B8.4, and B8.5) demonstrated their attenuation of PD-1/PD-L1 interactions. B8.4 exhibited the strongest attenuation efficiency at a half-maximal effective concentration of 0.1 μM and the strongest binding affinity to PD-1 (equilibrium dissociation constant = 0.1 μM). B8.4 outperformed the known PD-1/PD-L1 interaction inhibitor PL120131 in disrupting PD-1/PD-L1 interactions, revealing that B8.4 has remarkable potential for modification to yield an antitumor agent. This study provides valuable information for the future development of peptide-based drugs, therapeutics, and immunotherapies for cancer.

MicroRNAs as regulators of immune checkpoints in cancer immunotherapy: targeting PD-1/PD-L1 and CTLA-4 pathways

Immunotherapy has revolutionized cancer treatment by harnessing the power of the immune system to eliminate tumors. Immune checkpoint inhibitors (ICIs) block negative regulatory signals that prevent T cells from attacking cancer cells. Two key ICIs target the PD-1/PD-L1 pathway, which includes programmed death-ligand 1 (PD-L1) and its receptor programmed death 1 (PD-1). Another ICI targets cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). While ICIs have demonstrated remarkable efficacy in various malignancies, only a subset of patients respond favorably. MicroRNAs (miRNAs), small non-coding RNAs that regulate gene expression, play a crucial role in modulating immune checkpoints, including PD-1/PD-L1 and CTLA-4. This review summarizes the latest advancements in immunotherapy, highlighting the therapeutic potential of targeting PD-1/PD-L1 and CTLA-4 immune checkpoints and the regulatory role of miRNAs in modulating these pathways. Consequently, understanding the complex interplay between miRNAs and immune checkpoints is essential for developing more effective and personalized immunotherapy strategies for cancer treatment.

NSCLC: from tumorigenesis, immune checkpoint misuse to current and future targeted therapy

Non-small cell lung cancer (NSCLC) is largely promoted by a multistep tumorigenesis process involving various genetic and epigenetic alterations, which essentially contribute to the high incidence of mortality among patients with NSCLC. Clinical observations revealed that NSCLC also co-opts a multifaceted immune checkpoint dysregulation as an important driving factor in NSCLC progression and development. For example, a deregulated PI3K/AKT/mTOR pathway has been noticed in 50-70% of NSCLC cases, primarily modulated by mutations in key oncogenes such as ALK, EGFR, KRAS, and others. Additionally, genetic association studies containing patient-specific factors and local reimbursement criteria expose/reveal mutations in EGFR/ALK/ROS/BRAF/KRAS/PD-L1 proteins to determine the suitability of available immunotherapy or tyrosine kinase inhibitor therapy. Thus, the expression of such checkpoints on tumors and immune cells is pivotal in understanding the therapeutic efficacy and has been extensively studied for NSCLC treatments. Therefore, this review summarizes current knowledge in NSCLC tumorigenesis, focusing on its genetic and epigenetic intricacies, immune checkpoint dysregulation, and the evolving landscape of targeted therapies. In the context of current and future therapies, we emphasize the significance of antibodies targeting PD-1/PD-L1 and CTLA-4 interactions as the primary therapeutic strategy for immune system reactivation in NSCLC. Other approaches involving the promising potential of nanobodies, probodies, affibodies, and DARPINs targeting immune checkpoints are also described; these are under active research or clinical trials to mediate immune regulation and reduce cancer progression. This comprehensive review underscores the multifaceted nature, current state and future directions of NSCLC research and treatment.

Immune checkpoint expression patterns on T cell subsets in light-chain amyloidosis: VISTA, PD-1, and TIGIT as potential therapeutic targets

Amyloid light chain (AL) amyloidosis is a rare plasma cell dyscrasia with dismal prognosis. This study aims to investigate the T-cell immune checkpoint expression patterns in systemic AL amyloidosis and its relationship with clinicobiological traits. We examined the frequencies of V-domain immunoglobulin suppressor of T cell activation+ (VISTA+), programmed cell death 1+ (PD-1+), T cell immunoglobulin and mucin-domain-containing-3+ (Tim-3+), T cell immunoreceptor with Ig and ITIM domains+ (TIGIT+) T cells in peripheral blood (PB) and bone marrow (BM) from 19 patients with newly diagnosed AL amyloidosis. Patients with AL amyloidosis had significantly higher percentages of VISTA+ and PD-1+ T cells in PB than healthy individuals (HIs), with no statistical differences in BM. The percentages of some double-positive T cells in PB were also considerably higher in AL amyloidosis than those in HIs. Additionally, the patients with renal involvement had more PD-1+ and TIGIT+ T cells than the patients without, and PD-1+CD3+%, PD-1+CD4+%, PD-1+Treg% were positively correlated with 24-hour proteinuria levels. Furthermore, the AL amyloidosis patients had higher counts of PD-1+ Treg in PB than multiple myeloma (MM) patients, while the MM patients had higher counts of TIGIT+ T cells than AL amyloidosis patients. Collectively, this is the first report of elevated proportions of VISTA+ and PD-1+ T cells in PB of AL amyloidosis patients, indicating an immunosuppressive milieu, and the increased PD-1+ and TIGIT+ T cells were associated with renal damage. VISTA, PD-1, and TIGIT may be potential targets for reversing T-cell exhaustion in AL amyloidosis.

Tackling the immunotherapy conundrum: advances and challenges for operable non-small-cell lung cancer treatment

Lung cancer is the most common cause of cancer-related deaths worldwide. Non-small-cell lung cancer (NSCLC) represents the majority of lung cancer cases, and its standard treatment is primarily surgery. Nonetheless, this type of cancer exhibits an important rate of tumor recurrence. Immune checkpoint inhibitors (ICIs) have demonstrated significant survival benefits in many cancers, especially in early-stage NSCLC. This review considers the latest CheckMate816, IMpower010 and KEYNOTE-091 trials that led to US FDA approvals. The new wave of resectable NSCLC trial results are also summarized. Finally, the latest challenges for these treatment modalities, such as the choice between neoadjuvant and adjuvant use, the accurate identification of biomarkers and the presence of driver mutations such as EGFR, are discussed.

Expression of PD-1 and PD-L1 in Endometrial Cancer: Molecular and Clinical Significance

The landscape of diagnosing and treating endometrial cancer is undergoing a profound transformation due to the integration of molecular analysis and innovative therapeutic approaches. For several decades, the cornerstone treatments for endometrial cancer have included surgical resection, cytotoxic chemotherapy, hormonal therapy, and radiation therapy. However, in recent years, the concept of personalised medicine has gained momentum, reshaping the way clinicians approach cancer treatment. Tailoring treatments based on specific biomarkers has evolved into a standard practice in both initial and recurrent therapy protocols. This review aims to provide an in-depth exploration of the current state of molecular analysis and treatment strategies in the context of endometrial cancer, focusing on the immunological aspect of the PD-1/PD-L1 axis. Furthermore, it seeks to shed light on emerging and innovative approaches that hold promise for the future modulation of endometrial cancer treatments. In essence, as researchers delve into the complex molecular landscape of endometrial cancer and harness the understanding of the PD-1/PD-L1 axis, we are paving the way for more targeted, effective, and personalised therapies that have the potential to significantly improve the outcomes and quality of life for patients with this challenging disease.

Recent advances in non-small cell lung cancer targeted therapy; an update review

Lung cancer continues to be the leading cause of cancer-related death worldwide. In the last decade, significant advancements in the diagnosis and treatment of lung cancer, particularly NSCLC, have been achieved with the help of molecular translational research. Among the hopeful breakthroughs in therapeutic approaches, advances in targeted therapy have brought the most successful outcomes in NSCLC treatment. In targeted therapy, antagonists target the specific genes, proteins, or the microenvironment of tumors supporting cancer growth and survival. Indeed, cancer can be managed by blocking the target genes related to tumor cell progression without causing noticeable damage to normal cells. Currently, efforts have been focused on improving the targeted therapy aspects regarding the encouraging outcomes in cancer treatment and the quality of life of patients. Treatment with targeted therapy for NSCLC is changing rapidly due to the pace of scientific research. Accordingly, this updated study aimed to discuss the tumor target antigens comprehensively and targeted therapy-related agents in NSCLC. The current study also summarized the available clinical trial studies for NSCLC patients.

Development of a Functional Nanobody Targeting Programmed Cell Death Protein-1 as Immune Checkpoint Inhibitor

BACKGROUND

Programmed cell death protein 1 (PD-1) is a membrane receptor that is expressed on the surface of various immune cells, such as T cells, B cells, monocytes, natural killer T cells, and dendritic cells. In cancer, the interaction between PD-1 and its ligand PD-L1 suppresses the activation and function of T lymphocytes, leading to the impairment and apoptosis of tumor-specific T cells. This mechanism allows cancer cells to evade the immune response and promotes tumor progression.

METHODS

Recombinant PD-1 protein was produced and used to immunize a camel. A nanobody library was generated from the camel's peripheral blood lymphocytes and screened for PD-1 binding. A specific nanobody (3PD9) was selected and characterized by affinity measurement, western blotting, and flow cytometry analysis. The ability of the selected nanobody to block the inhibitory signal of PD-1 in peripheral blood mononuclear cells (PBMCs) was evaluated by measuring the level of interleukin-2 (IL-2).

RESULTS

The selected nanobody showed high specificity and affinity for human PD-1. Western blot and flow cytometry analysis confirmed that 3PD9 could recognize and bind to human PD-1 on the cell surface. It was demonstrated that the level of IL-2 was significantly increased in PBMCs treated with 3PD9 compared to the control group, indicating that the nanobody could enhance the T cell response by disrupting the PD-1/PD-L1 interaction.

CONCLUSION

The results suggested that the anti-PD-1 nanobody could be a promising candidate for cancer immunotherapy.

Dostarlimab an Inhibitor of PD-1/PD-L1: A New Paradigm for the Treatment of Cancer

Immunomodulation checkpoints usually adopted by healthy cells by tumors might cause an imbalance between host surveillance and tumor progression. Several tumors are incredibly resistant to standard treatment. The dynamic and long-lasting tumor regressions caused by antibodies targeting the PD-1/PD-L1 checkpoint have suggested a rebalancing of the host-tumor relationship. Checkpoint antibody inhibitors, like anti-PD-1/PD-L1, are unique inhibitors that reduce tumor growth by modulating the interaction between immune cells and tumor cells. These checkpoint inhibitors are swiftly emerging as a highly promising strategy for treating cancer because they produce impressive antitumor responses while having a limited number of adverse effects. Over the past several years, numerous checkpoint antibody inhibitors pointing to PD-1, PDL-1, and CTLA-4 have been available on the market. Despite its enormous success and usefulness, the anti-PD treatment response is restricted to certain kinds of cancer. This restriction can be attributed to the inadequate and diverse PD-1 expression in the tumor (MET) micro-environment. Dostarlimab (TSR-042), a drug that interferes with the PD-1/PD-L1 pathway, eliminates a crucial inhibitory response of an immune system and, as a result, has the potential to cause severe or deadly immune-mediated adverse effects. As cancer immunotherapy, dostarlimab enhances the antitumor immune response of the body.

Aqueous extract of Taxus chinensis var. mairei targeting CD47 enhanced antitumor effects in non-small cell lung cancer

Immunoglobulin protein CD47 is overexpressed in malignant tumor cells, allowing them to evade host immunity mainly by inhibiting macrophage-mediated phagocytosis. Taxus chinensis var. mairei (TC) exhibits high antitumor efficacy with low toxicity and notable cost-effectiveness. However, it is unknown whether aqueous extract of TC (AETC) is an immunomodulator that mediates antitumor efficacy. In this study, we aimed to elucidate the critical role of CD47 degradation in the treatment of AETC in non-small cell lung cancer (NSCLC) cells. A mouse Lewis lung carcinoma model was developed to determine whether the administration of AETC, as an anti-CD47 antibody, in combination with anti-PD-1 could synergistically inhibit tumor growth and promote a peripheral immune response. AETC treatment downregulated CD47 levels in NSCLC cells and Lewis tumor xenograft mice. Furthermore, treatment enhanced immunity against NSCLC by triggering CD47 ubiquitination and degradation, promoting macrophage-mediated tumor cell phagocytosis, and activating CD8⁺ T cells. The present study empirically demonstrated, for the first time, that AETC exerts antitumor properties as an immunomodulator. Our findings present AETC as a promising alternative or adjuvant treatment in lung cancer therapy.

Crosstalk between the B7/CD28 and EGFR pathways: Mechanisms and therapeutic opportunities

Somatic activating mutations in the epidermal growth factor receptor (EGFR) are one of the most common oncogenic drivers in cancers such as non-small-cell lung cancer (NSCLC), metastatic colorectal cancer, glioblastoma, head and neck cancer, pancreatic cancer, and breast cancer. Molecular-targeted agents against EGFR signaling pathways have shown robust clinical efficacy, but patients inevitably experience acquired resistance. Although immune checkpoint inhibitors (ICIs) targeting PD-1/PD-L1 have exhibited durable anti-tumor responses in a subset of patients across multiple cancer types, their efficacy is limited in cancers harboring activating gene alterations of EGFR. Increasing studies have demonstrated that upregulation of new B7/CD28 family members such as B7-H3, B7x and HHLA2, is associated with EGFR signaling and may contribute to resistance to EGFR-targeted therapies by creating an immunosuppressive tumor microenvironment (TME). In this review, we discuss the regulatory effect of EGFR signaling on the PD-1/PD-L1 pathway and new B7/CD28 family member pathways. Understanding these interactions may inform combination therapeutic strategies and potentially overcome the current challenge of resistance to EGFR-targeted therapies. We also summarize clinical data of anti-PD-1/PD-L1 therapies in EGFR-mutated cancers, as well as ongoing clinical trials of combination of EGFR-targeted therapies and anti-PD-1/PD-L1 immunotherapies.

Understanding the functional inflammatory factors involved in therapeutic response to immune checkpoint inhibitors for pan-cancer

Immune checkpoint inhibitors (ICIs) fight tumor progression by activating immune conditions. The inflammatory factors are playing a functional role in programmed death-1 (PD-1) or other immune checkpoints. They are involved in regulating the expression of programmed death ligand-1 (PD-L1), the only predictor recognized by the guidelines in response to ICIs. In addition, abundant components of the tumor microenvironment (TME) all interact with various immune factors contributing to the response to ICIs, including infiltration of various immune cells, extracellular matrix, and fibroblasts. Notably, the occurrence of immune-related adverse events (irAEs) in patients receiving ICIs is increasingly observed in sundry organs. IrAEs are often regarded as an inflammatory factor-mediated positive feedback loop associated with better response to ICIs. It deserves attention because inflammatory factors were observed to be different when targeting different immune checkpoints or in the presence of different irAEs. In the present review, we address the research progresses on regulating inflammatory factors for an intentional controlling anti-cancer response with immune checkpoint inhibitors.

A comprehensive review about the utilization of immune checkpoint inhibitors and combination therapy in hepatocellular carcinoma: an updated review

A pharmacological class known as immune checkpoint inhibitors (ICIs) has been developed as a potential treatment option for various malignancies, including HCC. In HCC, ICIs have demonstrated clinically significant advantages as monotherapy or combination therapy. ICIs that target programmed cell death protein 1 (PD-1) and programmed cell death protein ligand 1 (PD-L1), as well as cytotoxic T lymphocyte antigen 4 (CTLA-4), have made significant advances in cancer treatment. In hepatocellular carcinoma (HCC), several ICIs are being tested in clinical trials, and the area is quickly developing. As immunotherapy-related adverse events (irAEs) linked with ICI therapy expands and gain worldwide access, up-to-date management guidelines become crucial to the safety profile of ICIs. This review aims to describe the evidence for ICIs in treating HCC, emphasizing the use of combination ICIs.

Synergistic effects of nab-PTX and anti-PD-1 antibody combination against lung cancer by regulating the Pi3K/AKT pathway through the Serpinc1 gene

Lung cancer is a type of cancer with higher morbidity and mortality. In spite of the impressive response rates of nab-paclitaxel (nab-PTX) or programmed cell death-1 (PD-1) and its ligand inhibitors, the effective treatment remains limited. Currently, alternative strategies aim at drug combination of nab-PTX and PD-1/PD-L1 inhibitors. Even as the clinical impact of the combined agents continues to increase, basic research studies are still limited and the mechanisms underlying this synergy are not well studied. In this study, we evaluated the antitumor efficacy and the molecular mechanisms of action of nab-PTX in combination with anti-PD-1 antibody, using Lewis lung carcinoma (LLC) cell and subcutaneously transplanted tumor models. The combination of nab-PTX and anti-PD-1 antibody displayed stronger antitumor effects, manifested at tumor volume, proliferation and apoptosis through Ki67 and TUNEL staining. In-vivo experiments showed significant increases in CD4+ T cells, CD8+ T cells, IFN-γ, TNF-α, IL-2, PF, and Gzms-B, exerting antitumor effects with reductions in MDSCs and IL-10 after the treatments. Furthermore, transcriptomic analysis indicated 20 overlapped differentially expressed genes, and Serpin peptidase inhibitor clade C Member 1 (Serpinc1) was downregulated during treatment in vivo, whose expression level was markedly related to metastasis and overall survival of lung cancer patients. Functional enrichment analysis of the target gene revealed primary GO terms related to tumor, which warrants further investigation. We also found that Serpinc1 overexpression promoted cell proliferation, migration, and invasion and inhibited cell apoptosis of LLC cells in vitro, possibly regulating the associated factors via the Pi3K/AKT pathway. In summary, our results reveal the synergistic antitumor responses of nab-PTX combined with anti-PD-1 antibody, in which Serpinc1 may play an important role, providing a target gene for combination treatment strategy.

The association study of chemical compositions and their pharmacological effects of Cyperi Rhizoma (Xiangfu), a potential traditional Chinese medicine for treating depression

ETHNOPHARMACOLOGICAL RELEVANCE

Cyperi Rhizoma (CR) derives from the rhizome or tuber of Cyperus rotundus L. of Cyperaceae. It is an herbal medicine which has been widely used in different healthcare systems like in China, India, Iran, and Japan. In Chinese medicine, CR could promote the flow of Qi in the Liver and Sanjiao channels, regulate menstruation and alleviate pain. Clinically, CR is used for depression, flatulence, hypochondriac pain, and dysmenorrhea. Thus, it has a long history and significant curative effect for the treatment of various Qi stagnation symptoms.

AIM OF THIS REVIEW

This review focuses on explaining the major antidepressant mechanisms of CR, and assessing the shortcomings of existing work. Besides, clinical applications, pharmacological effects and their corresponding chemical compositions and quality control of CR have been researched.

MATERIALS AND METHODS

The search terms "Cyperus rotundus L." was used to obtain the literatures from electronic databases such as Web of Science, ScienceDirect, PubMed, and China National Knowledge Infrastructure (CNKI). The information provided in this review to illustrate material basis of CR were only limited to papers which reported on the chemical compositions and pharmacological effects simultaneously.

RESULT

The study showed that CR has significant application in Qi stagnation, like depressed liver, stomach, and bowel disorders, etc. in different countries or districts. Aqueous extract, EtOH extract, essential oil, total oligomeric flavonoids and five other extracts were effective constituents displaying pharmacological activities such as antibacterial, antioxidant, neuroprotective, antihemolytic, and anti-inflammatory effect. 41 kinds of specific components like α-cyperone, nootkatone exhibited corresponding pharmacological activities mentioned above. Different concentrations of ethanol extract, essential oil, decoction of CR and monomer composition like α-cyperone, rotunduside G had anti-depressant effects.

CONCLUSIONS

In the present study, we have provided scientific information and research developments on traditional uses, phytochemical compositions and corresponding pharmacological activities, and quality control status on CR. The antidepression effect and its corresponding chemical compositions were generalized separately. The pharmacological activities studies should be more focused on the reflection of traditional clinical values. CR could be a significant potential herbal medicine to develop antidepressant drugs with lower side effects.

The evolutionary legacy of immune checkpoint inhibitors

Immune check point inhibitors (ICIs) have marked their existence in the field of cancer immunotherapy. Their existence dates to 2011 when the first anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) got its FDA approval for the management of metastatic melanoma. The class of ICIs now also include antibodies against programmed cell death-1 (PD-1) and its ligand (PD-L1) which immediately gained FDA approval for use against multiple cancer types because of their effect on patient survival. These discoveries were followed by a significant rise in the identification of novel ICIs with potential anti-tumor response. Researchers have identified various novel checkpoint inhibitors which are currently under clinical trials. Despite the success of ICIs, only a small subset of patients with specific tumor types achieves a promising response. Not only efficient therapeutic response but also development of resistance, recurrence and other immune-related adverse effects limit the applicability of immune checkpoint inhibitors. These challenges can only be addressed when a directed approach is implemented at both basic and translational level. In this review, we have briefly discussed the history of ICIs, the next generation of inhibitors which are currently under clinical trial and mechanisms of resistance that can lead to treatment failure. Ultimately, by combining these insights researchers might be able to achieve a more durable and effective response in cancer patients.

A Review of Emerging Biomarkers for Immune Checkpoint Inhibitors in Tumors of the Gastrointestinal Tract

In recent years, immune checkpoint inhibition (ICI) therapy has made a tremendous improvement in the treatment of malignant tumors of gastrointestinal tract, especially for those with metastatic or recurrent lesions. However, while some patients benefit from ICI, others do not. In fact, predictive biomarkers can play a crucial role in screening patients who may benefit from a selected or targeted treatment, including immunotherapies such as programmed death-1/programmed death-1 ligand 1 (PD-1/PD-L1) inhibitors. A variety of techniques can be used to detect and quantify tumor biomarkers, each of which has a specific clinical application scenario and limitations. Cancer biomarkers in the gastrointestinal system involve an extremely complex network that requires careful interpretation and analysis. Different prognostic or predictive biomarkers are playing important roles in various tumor types, stages, and pathology/molecular subgroups, sometimes overlapping. Expression levels of biomarkers vary between different tumor types and even between the different lesions in the same tumor, depending on the heterogeneity of the patient, the tumor types, and the techniques of detection. The present systematic review comprehensively summarizes the potential biomarkers of immunotherapy, such as PD-1/PD-L1, total mutation burden (TMB), and tumor-infiltrating lymphocytes (TILs) in various gastrointestinal tumors, including tumors of the colon, stomach, esophagus, liver, and pancreas, to assist future application of immunotherapy and patient selection in clinical practice.

Integrated genomic and DNA methylation analysis of patients with advanced non-small cell lung cancer with brain metastases

BACKGROUND

Brain metastasis is a common and lethal complication of non-small cell lung cancer (NSCLC). It is mostly diagnosed only after symptoms develop, at which point very few treatment options are available. Therefore, patients who have an increased risk of developing brain metastasis need to be identified early. Our study aimed to identify genomic and epigenomic biomarkers for predicting brain metastasis risk in NSCLC patients.

METHODS

Paired primary lung tumor tissues and either brain metastatic tissues or cerebrospinal fluid (CSF) samples were collected from 29 patients with treatment-naïve advanced NSCLC with central nervous system (CNS) metastases. A control group comprising 31 patients with advanced NSCLC who died without ever developing CNS metastasis was also included. Somatic mutations and DNA methylation levels were examined through capture-based targeted sequencing with a 520-gene panel and targeted bisulfite sequencing with an 80,672 CpG panel.

RESULTS

Compared to primary lung lesions, brain metastatic tissues harbored numerous unique copy number variations. The tumor mutational burden was comparable between brain metastatic tissue (P = 0.168)/CSF (P = 0.445) and their paired primary lung tumor samples. Kelch-like ECH-associated protein (KEAP1) mutations were detected in primary lung tumor and brain metastatic tissue samples of patients with brain metastasis. KEAP1 mutation rate was significantly higher in patients with brain metastasis than those without (P = 0.031). DNA methylation analysis revealed 15 differentially methylated blocks between primary lung tumors of patients with and without CNS metastasis. A brain metastasis risk prediction model based on these 15 differentially methylated blocks had an area under the curve of 0.94, with 87.1% sensitivity and 82.8% specificity.

CONCLUSIONS

Our analyses revealed 15 differentially methylated blocks in primary lung tumor tissues, which can differentiate patients with and without CNS metastasis. These differentially methylated blocks may serve as predictive biomarkers for the risk of developing CNS metastasis in NSCLC. Additional larger studies are needed to validate the predictive value of these markers.

Emerging Role of PD-1/PD-L1 Inhibitors in Chronic Liver Diseases

Programmed cell death protein 1 (PD-1)/PD-ligand (L)1, the immune checkpoint inhibitors have emerged as a promising strategy for the treatment of various diseases including chronic liver diseases (CLDs) such as hepatitis, liver injury and hepatocellular carcinoma (HCC). The role of PD-1/PD-L1 has been widely inspected in the treatment of viral hepatitis and HCC. PD-1 is known to play a crucial role in inhibiting immunological responses and stimulates self-tolerance by regulating the T-cell activity. Further, it promotes apoptosis of antigen-specific T-cells while preventing apoptosis of Treg cells. PD-L1 is a trans-membrane protein which is recognized as a co-inhibitory factor of immunological responses. Both, PD-1 and PD-L1 function together to downregulate the proliferation of PD-1 positive cells, suppress the expression of cytokines and stimulate apoptosis. Owing to the importance of PD-1/PD-L1 signaling, this review aims to summarize the potential of PD-1/PD-L1 inhibitors in CLDs along with toxicities associated with them. We have enlisted some of the important roles of PD-1/PD-L1 in CLDs, the clinically approved products and the pipelines of drugs under clinical evaluation.

Uncovering the Anti-Lung-Cancer Mechanisms of the Herbal Drug FDY2004 by Network Pharmacology

With growing evidence on the therapeutic efficacy and safety of herbal drugs, there has been a substantial increase in their application in the lung cancer treatment. Meanwhile, their action mechanisms at the system level have not been comprehensively uncovered. To this end, we employed a network pharmacology methodology to elucidate the systematic action mechanisms of FDY2004, an anticancer herbal drug composed of Moutan Radicis Cortex, Persicae Semen, and Rhei Radix et Rhizoma, in lung cancer treatment. By evaluating the pharmacokinetic properties of the chemical compounds present in FDY2004 using herbal medicine-associated databases, we identified its 29 active chemical components interacting with 141 lung cancer-associated therapeutic targets in humans. The functional enrichment analysis of the lung cancer-related targets of FDY2004 revealed the enriched Gene Ontology terms, involving the regulation of cell proliferation and growth, cell survival and death, and oxidative stress responses. Moreover, we identified key FDY2004-targeted oncogenic and tumor-suppressive pathways associated with lung cancer, including the phosphatidylinositol 3-kinase-Akt, mitogen-activated protein kinase, tumor necrosis factor, Ras, focal adhesion, and hypoxia-inducible factor-1 signaling pathways. Overall, our study provides novel evidence and basis for research on the comprehensive anticancer mechanisms of herbal medicines in lung cancer treatment.

Immune checkpoint: The novel target for antitumor therapy

Inhibitory checkpoint molecules include programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), cytotoxic T lymphocyte antigen-4 (CTLA-4), human endogenous retrovirus-H Long terminal repeat-associating 2 (HHLA2), B7 homolog 4 protein (B7-H4), T cell membrane protein-3 (TIM-3) and Lymphocyte-activation gene 3 (LAG-3), which are up-regulated during tumorigenesis. These pathways are essential to down-regulate the immune system by blocking the activation of T cells. In recent years, immune checkpoint blockers (ICBs) against PD-1, PD-L1, CTLA-4 or TIM-3 has made remarkable progress in the clinical application, revolutionizing the treatment of malignant tumors and improving patients' overall survival. However, the efficacy of ICBs in some patients does not seem to be good enough, and more immune-related adverse events (irAEs) will inevitably occur. Therefore, biomarkers research provides practical guidance for clinicians to identify patients who are most likely to benefit from or exhibit resistance to particular types of immune checkpoint therapy. There are two points in general. On the one hand, given the spatial and temporal differential expression of immune checkpoint molecules during immunosuppression process, it is essential to understand their mechanisms to design the most effective individualized therapy. On the other hand, due to the lack of potent immune checkpoints, it is necessary to combine them with novel biomarkers (such as exosomes and ctDNA) and other anticancer modalities (such as chemotherapy and radiotherapy).

Anti-EGFR Fibronectin Bispecific Chemically Self-Assembling Nanorings (CSANs) Induce Potent T Cell-Mediated Antitumor Responses and Downregulation of EGFR Signaling and PD-1/PD-L1 Expression

Overexpression of the epidermal growth factor receptor (EGFR) on various cancers makes it an important target for cancer immunotherapy. We recently demonstrated that single-chain variable fragment-based bispecific chemically self-assembled nanorings (CSANs) can successfully modify T cell surfaces and function as prosthetic antigen receptors (PARs) allowing selective targeting of tumor antigens while incorporating a dissociation mechanism of the rings. Here, we report the generation of anti-EGFR fibronectin (FN3)-based PARs with high yield, rapid protein production, predicted low immunogenicity, and increased protein stability. We demonstrated the cytotoxicity of FN3-PARs successfully while evaluating FN3 affinities, CSAN valencies, and antigen expression levels. Using an orthotopic breast cancer model, we showed that FN3-PARs can suppress tumor growth with no adverse effects and FN3-PARs reduced immunosuppressive programmed cell death ligand-1 (PD-L1) expression by downregulating EGFR signaling. These results demonstrate the potential of FN3-PARs to direct selective T cell-targeted tumor killing and to enhance antitumor T cell efficacy by modulating the tumor microenvironment.

EGFR: An essential receptor tyrosine kinase-regulator of cancer stem cells

The Epidermal Growth Factor Receptor (EGFR) is frequently expressed at elevated levels in different forms of cancer and expression often correlates positively with cancer progression and poor prognosis. Different mutant forms of this protein also contribute to cancer heterogeneity. A constitutively active form of EGFR, EGFRvIII is one of the most important variants. EGFR is responsible for the maintenance and functions of cancer stem cells (CSCs), including stemness, metabolism, immunomodulatory-activity, dormancy and therapy-resistance. EGFR regulates these pathways through several signaling cascades, and often cooperates with other RTKs to exert further control. Inhibitors of EGFR have been extensively studied and display some anticancer efficacy. However, CSCs can also acquire resistance to EGFR inhibitors making effective therapy even more difficult. To ameliorate this limitation of EGFR inhibitors when used as single agents, it may be of value to simultaneously combine multiple EGFR inhibitors or use EGFR inhibitors with regulators of other important cancer phenotype regulating molecules, such as STAT3, or involved in important processes such as DNA repair. These combinatorial approaches require further experimental confirmation, but if successful would expand and improve therapeutic outcomes employing EGFR inhibitors as one arm of the therapy.

Uptake of positron emission tomography tracers reflects the tumor immune status in esophageal squamous cell carcinoma

The relationship between the local immune status and cancer metabolism regarding ¹⁸F‐FDG and ¹⁸F‐FAMT uptake in esophageal squamous cell carcinoma (ESCC) remains unknown. The present study examined the correlations between tumor immune status, clinicopathological factors, and positron emission tomography (PET) tracer uptake in ESCC. Forty‐one ESCC patients who underwent ¹⁸F‐FDG PET and ¹⁸F‐FAMT PET before surgery were enrolled in the study. Immunohistochemistry was conducted for programmed death 1 (PD‐1), CD8, Ki‐67, CD34, GLUT1 (¹⁸F‐FDG transporter) and LAT1 (¹⁸F‐FAMT transporter). ESCC specimens with high tumoral PD‐L1 and high CD8‐positive lymphocytes were considered to have “hot tumor immune status.” High PD‐L1 expression (53.7%) was significantly associated with tumor/lymphatic/venous invasion (P = 0.028, 0.032 and 0.018), stage (P = 0.041), CD8‐positive lymphocytes (P < 0.001), GLUT1 (P < 0.001), LAT1 expression (P = 0.006), Ki‐67 labelling index (P = 0.009) and CD34‐positive vessel counts (P < 0.001). SUVmax of ¹⁸F‐FDG was significantly higher in high PD‐L1 cases than in low PD‐L1 cases (P = 0.009). SUVmax of ¹⁸F‐FAMT was significantly higher in high PD‐L1 (P < 0.001), high CD8 (P = 0.012) and hot tumor groups (P = 0.028) than in other groups. High SUVmax of ¹⁸F‐FAMT (≥4.15) was identified as the only predictor of hot tumor immune status. High PET tracer uptake was significantly associated with cancer aggressiveness and hot tumor immune status in ESCC. PET imaging may be an effective tool to predict tumor immune status in ESCC with respect to immune checkpoint inhibitor sensitivity.

PD-1/PD-L1 pathway: current researches in cancer

Cancer immunotherapy has been accompanied by promising results over the past few years. Programmed Cell Death Protein 1 (PD-1) plays a vital role in inhibiting immune responses and promoting self-tolerance through modulating the activity of T-cells, activating apoptosis of antigen-specific T cells and inhibiting apoptosis of regulatory T cells. Programmed Cell Death Ligand 1 (PD-L1) is a trans-membrane protein that is considered to be a co-inhibitory factor of the immune response, it can combine with PD-1 to reduce the proliferation of PD-1 positive cells, inhibit their cytokine secretion and induce apoptosis. PD-L1 also plays an important role in various malignancies where it can attenuate the host immune response to tumor cells. Based on these perspectives, PD-1/PD-L1 axis is responsible for cancer immune escape and makes a huge effect on cancer therapy. This review is aimed to summarize the role of PD-1 and PD-L1 in cancer, looking forward to improve the therapy of cancer.

FRA1 contributes to MEK-ERK pathway-dependent PD-L1 upregulation by KRAS mutation in premalignant human bronchial epithelial cells

Oncogenic KRAS mutations are frequently found in non-small cell lung carcinoma (NSCLC) and cause constitutive activation of the MEK-ERK pathway. Many cancer types have been shown to overexpress PD-L1 to escape immune surveillance. FRA1 is a MEK/ERK-dependent oncogenic transcription factor and a member of the AP-1 transcriptional factor superfamily. This study assesses the hypothesis that KRAS mutation directly regulates PD-L1 expression through the MEK-ERK pathway mediated by FRA1. Premalignant human bronchial epithelial cell (HBEC) lines harboring the KRAS mutation^V12, EGFR mutation, p53 knock-down, or both KRAS mutation and p53 knock-down were tested for levels of PD-L1, FRA1, and ERK activation (pERK). Our results showed that KRAS mutation alone, but not other genetic alterations, induced significantly higher expression of PD-L1 compared to its vector counterparts. The increased PD-L1 expression in the KRAS mutated cells was dramatically reduced by inhibition of ERK activation. Furthermore, the MEK-ERK pathway-dependent PD-L1 expression was markedly reduced by FRA1 silencing. Interestingly, FRA1 silencing led to inhibition of ERK activation, indicating that FRA1 plays a role in PD-L1 regulation via positive feedback of ERK activation. Correlation of PD-L1 and FRA1 mRNA expression was validated using human lung cancer specimens from The Cancer Genome Atlas (TCGA) and established NSCLC cell lines from Cancer Cell Line Encyclopedia (CCLE). FRA1 expression was significantly associated with PD-L1 expression, and high FRA1 expression was correlated with poor overall survival. Our findings suggest that oncogenic KRAS-driven PD-L1 expression is dependent on MEK-ERK and FRA1 in high risk, premalignant HBEC.

Stromal PD-1+ tumor-associated macrophages predict poor prognosis in lung adenocarcinoma

Immunotherapies targeting programmed cell death protein 1 (PD-1)/PD-1 ligand (PD-L1) axis have been emerging as a promising therapeutic strategy to treat lung cancer. PD-1 is preferentially expressed by activated T lymphocytes; but whether/how its expression by tumor-associated macrophages (TAMs) in lung adenocarcinoma remains elusive. Herein, we investigate the frequency of PD-1 expression on TAMs in mouse allografts by flow cytometry analysis and evaluate the spatial distribution and clinicopathological significance of PD-1⁺ TAMs in 213 cases of human lung adenocarcinoma specimens by immunohistochemical staining. We find the expression of PD-1 by both mouse and human TAMs. Mouse PD-1⁺ TAMs possess unique transcriptional profile as compared to PD-1^- TAMs. Furthermore, PD-1 is preferentially expressed by CD163⁺ TAMs in the tumor stroma than those in the tumor islets of lung adenocarcinoma. Stromal PD-1⁺ TAM infiltration is an independent predictor of reduced survival as determined by univariate (P < .001) and multivariate (P = .023) analysis. Moreover, patients with high stromal PD-1⁺ TAMs but low tumor cell PD-L1 expression have the shortest survival (P = .0001). Our study demonstrates that PD-1⁺ TAMs have unique gene expression characteristics and PD-1⁺ TAMs in the tumor stroma is a potential prognostic factor in lung adenocarcinoma, suggesting that a better understanding of PD-1⁺ TAMs will be beneficial for immunotherapy of lung adenocarcinoma patients.

Correlation of programmed death-ligand 1 expression with gene expression and clinicopathological parameters in Indian patients with non-small cell lung cancer

Objectives:

The aim of this study is to evaluate the incidence of programmed cell death-ligand 1 (PD-L1) expression in non-small cell lung cancer (NSCLC) cases and its correlation with gene mutation and clinicopathological parameters.

Methods:

Samples from NSCLCs patients were studied for PD-L1 expression through immunohistochemistry (IHC) using Rabbit anti-human PDL-1/CD274 Monoclonal Antibody. Genetic mutations were studied using IHC/fluorescence in situ hybridization (FISH) methods (for anaplastic lymphoma kinase [ALK]) or polymerase chain reaction/gene sequencing analysis (for epidermal growth factor receptor [EGFR]). Pearson's correlation coefficient (r) was used for correlation analysis. PD-L1 expression was analyzed for association with clinicopathological features.

Results:

Of the 101 NSCLC cases, PD-L1 expression was observed in 33.66% (34/101) cases; tumor proportion score of <50%: 67.65% (23/34) and ≥50%: 32.35% (11/34) cases. PD-L1 positivity was seen in; males: 35.5%, females: 28%, smokers: 37.7%, cases with brain metastasis: 20%, cases with pleural effusion: 20.8%, and histopathological evaluation (well-differentiated: 21.42%, moderately-differentiated: 13.79%, poorly-differentiated: 36.11%, and adenosquamous disease: 40.9%). Genetic mutation studies revealed PD-L1 positivity in 18.1% cases with EGFR mutation, 50% of ALK-IHC positive cases, and 33.3% ALK-FISH positive cases. No or very weak correlation (r < 0.3) in PD-L1 expression with gene mutations or clinicopathological parameters was observed.

Conclusions:

The study demonstrated PD-L1 expression in ~ 1/3^rd cases of NSCLC patients. No or very weak correlation was observed for PD-L1 expression with genetic mutations and other parameters studied. The presence of gene mutations in PD-L1 expressed samples suggests further investigation on PD-L1 inhibitors in such patients for decisive treatments.

Ectonucleotidase CD39 and Checkpoint Signalling Receptor Programmed Death 1 are Highly Elevated in Intratumoral Immune Cells in Non-small-cell Lung Cancer

Lung cancer is the leading cause of cancer death in both sexes worldwide and has a predicted 5-year survival rate of <20%. Immunotherapy targeting immune checkpoints such as the programmed death 1 (PD-1) signaling pathway has led to a shift of paradigm in the treatment of advanced non-small-cell lung cancer (NSCLC) but remains without effect in ∼80% of patients. Accumulating evidence suggests that several immunosuppressive mechanisms may work together in NSCLC. The contribution and cooperation between different immunosuppressive mechanisms in NSCLC remain unknown. Recently, the CD39-adenosine pathway has gained increasing attention as a crucial immunosuppressive mechanism and possible target for immunotherapy. Immune cells were extracted from lung and tumor tissue after lung resection in 12 patients by combined enzymatic and mechanical tissue disaggregation. A multiparameter flow cytometry panel was established to investigate the expression and coexpression of CD39 and PD-1 on key lymphocyte subtypes. Frequencies of CD39+, PD-1+, and CD39+/PD-1+cells were higher among both CD4+ and CD8+ T cells isolated from NSCLC tumor tissue than in T cells from normal lung tissue. Similarly, the frequency of FoxP3+ CD4+ T cells (Tregs) was highly significantly elevated in tumor tissue compared to adjacent lung tissue. The consistent upregulation of CD39 on immune cells in tumor microenvironment indicates that the CD39 signaling pathway may, in addition to the PD-1 pathway, represent another important mechanism for tumor-induced immunosuppression in NSCLC. In addition, the present study indicates that a comprehensive immune response profiling with flow cytometry may be both feasible and clinically relevant.

Epidermal Growth Factor Receptor Mutations in Resectable Non-Small Cell Lung Cancer Patients and their Potential Role in the Immune Landscape

BACKGROUND The epidermal growth factor receptor (EGFR) is a therapeutic target for non-small cell lung cancer (NSCLC), but knowledge on gene mutations that contribute to NSCLC development and persistence is lacking. In this study, we investigated genetic variations in EGFR and their association with the clinical and pathological factors of NSCLC. MATERIAL AND METHODS Clinical cases (331 patients) and The Cancer Genome Atlas (TCGA) cases (1040 patients) were selected and analyzed using the refractory mutation systems cBioPortal and the Tumor Immune Estimation Resource (TIMER). RESULTS EGFR mutation frequencies were 54.4% (180 of 331 patients) and 8.0% (83 of 1040 patients) in the clinical and TCGA cohorts, respectively. EGFR mutations were strongly associated with smoking and pathology (P≤0.05) in the clinical cohort, and with gender, smoking, and pathology (P=0.001, P<0.001, and P<0.001, respectively) in TCGA cohort. In cases of lung squamous carcinoma (LUSC), EGFR was overexpressed as a result of DNA amplification, but this amplified expression showed no association with the overall survival (OS) or progression-free survival of LUSC patients. EGFR gene alterations were, however, associated with worse OS in lung adenocarcinoma (LUAD) patients. Immune cell infiltrates from LUAD and LUSC tumors differed according to EGFR expression. EGFR mutations resulted in a decline of immune infiltration or a lack of infiltrating immune cells in the NSCLC microenvironment. CONCLUSIONS Mutational profiles of the EGFR in NSCLC patients provide useful information for the use of tyrosine kinase inhibitors for adjuvant or neoadjuvant therapy and immunotherapy.

The landscape of immune microenvironment in lung adenocarcinoma and squamous cell carcinoma based on PD-L1 expression and tumor-infiltrating lymphocytes

AIMS

The aim of this study was to investigate the tumor microenvironment immune types (TMIT) based on tumor cell programmed cell death ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs) distribution and whether distinct TMIT subtypes (TMIT I, PD-L1^high /TIL^high ; TMIT II, PD-L1^low /TIL^low ; TMIT III, PD-L1^high /TIL^low ; and TMIT IV, PD-L1^low /TIL^high ) differentially affect clinical outcomes of patients with lung adenocarcinoma (LAC) and squamous cell carcinoma (SCC).

METHODS AND RESULTS

Immunohistochemistry (IHC) was applied to evaluate the expression of PD-L1 and the spatial distribution of programmed cell death 1 (PD-1) and CD8 TILs on the surgically resected specimens from 205 cases of LAC and 149 cases of SCC. PD-1 and CD8 TILs were more frequently distributed in SCC than those in LAC, regardless of their infiltrating in the tumor islets or stroma. The density of TILs was a poor prognostic factor in LAC but a favorable one in SCC. PD-L1 levels and its clinical prognostic significance differed in LAC vs SCC. LAC patients with TMIT III and SCC patients with TMIT I had the longest survival, respectively (P = .0197 and .0049). Moreover, TMIT stratification based on tumor cell PD-L1 expression and stromal CD8⁺ TILs could be considered as an independent prognostic factor of SCC patients' survival as determined by both univariate and multivariate analysis.

CONCLUSION

Our study indicates that different type of TMIT provides its specific microenvironment with diverse impact on survival of LAC and SCC patients and highlights the importance of the integrative assessment of PD-L1 status and TILs' spatial distribution to predict patients' prognosis.

PD-L1 Induction by Cancer-Associated Fibroblast-Derived Factors in Lung Adenocarcinoma Cells

Cancer-associated fibroblasts (CAFs) exert various effects upon biological behaviours of cancer. In this study, we examined the correlation of CAFs with the intra-tumoural immune system in the lung adenocarcinoma microenvironment. We studied 27 and 113 cases of lung adenocarcinoma tentatively as Cohorts 1 and 2, respectively. The patients in Cohort 1 received epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) for recurrent lung adenocarcinoma. α-smooth muscle actin (α-SMA), a surrogate marker for CAFs, was examined by immunohistochemistry. We then examined the effects of CAFs isolated from lung cancer tissues on programmed death ligand 1 (PD-L1) expression in lung adenocarcinoma cell lines. No significant associations were detected between α-SMA status and the ratios of CD8/CD4 and Foxp3/CD8 in Cohort 1. However, α-SMA status was significantly associated with PD-L1 status in both Cohorts 1 and 2. Conditioned medium of CAFs significantly induced PD-L1 expression in lung adenocarcinoma cell lines, A549, PC-9, and H1975. Among the cytokines examined by antibody array, C-X-C motif chemokine ligand 2 (CXCL2) increased PD-L1 mRNA expression in these cell lines. CXCL2 is therefore considered to have a potential to induce PD-L1 expression in lung adenocarcinoma cells as a result of an interaction between carcinoma cells and CAFs. These findings did firstly demonstrate that CAFs indirectly influenced tumour immunity through increasing PD-L1 expression in lung adenocarcinoma cells.

Tumor necrosis correlates with PD-L1 and PD-1 expression in lung adenocarcinoma

Background: Predictive biomarkers for immunotherapy in lung cancer are intensively investigated; however, correlations between PD-L1/PD-1 expressions and clinical features or histopathological tumor characteristics determined on hematoxylin and eosin stained sections have not extensively been studied. Material and methods: We determined PD-L1 expression of tumor cells (TC) and immune cells (IC), and PD-1 expression of IC by immunohistochemistry in 268 lung adenocarcinoma (LADC) patients, and correlated the data with smoking, COPD, tumor grade, necrosis, lepidic growth pattern, vascular invasion, density of stromal IC, and EGFR/KRAS status of the tumors. Results: There was a positive correlation between PD-L1 expression of TC and IC, as well as PD-L1 and PD-1 expression of IC. Tumor necrosis was associated with higher PD-L1 expression of TC and PD-1 expression of IC. A negative correlation was observed between lepidic growth pattern and PD-L1 expression of TC and PD-L1/PD-1 expression of IC. EGFR mutation seemed to negatively correlate with PD-1 expression of IC, but this tendency could not be verified when applying corrections for multiple comparisons. No significant effect of the KRAS mutation on any of the studied variables could be established. Conclusion: Here we first demonstrate that the presence of necrosis correlates with higher PD-L1 expression of TC and PD-1 expression of IC in LADC. Further studies are required to determine the predictive value of this observation in LADC patients receiving immunotherapy.

Mechanisms of Resistance to Immune Checkpoint Antibodies

Immunotherapy using checkpoint inhibitors has changed the way we treat several aggressive cancers such as melanoma, non-small cell lung and head & neck cancers, among others, with durable responses achieved in the metastatic setting. However, unfortunately, the vast majority of patients do not respond to checkpoint inhibition therapy and a minority of patients, who do respond to treatment, develop secondary resistance and experience relapse by mechanisms still inadequately understood. Emerging evidence shows that alterations in multiple signaling pathways are involved in primary and/or secondary resistance to checkpoint inhibition. In this review we discuss how selected cancer-cell autonomous cues may influence the outcome of cancer immunotherapy, particularly immune checkpoint inhibition.

Effectiveness of first-line treatments in metastatic squamous non-small-cell lung cancer

Background

Commonly used first-line (1L) chemotherapies for patients with advanced squamous-cell lung cancer (scc) include gemcitabine-platinum (gp), nab-paclitaxel-carboplatin (nabpc), and sb-paclitaxel-carboplatin (sbpc) regimens. However, no head-to-head trials have compared those treatments. In the present study, we compared the efficacy of 1L gp, nabpc, and sbpc in patients with scc and in patients with scc who subsequently received second-line (2L) immunotherapy.

Methods

Medical records of patients who initiated the 1L treatments of interest between June 2014 and October 2015 were reviewed by 132 participating physicians. Kaplan-Meier curves were used to evaluate overall survival (os), progression-free survival (pfs), and treatment discontinuation (td), and then Cox proportional hazards regression was used to compare the results between the cohorts.

Results

Medical records of 458 patients with scc receiving gp (n = 139), nabpc (n = 159), or sbpc (n = 160) as 1L therapy were reviewed. Median os was longer with nabpc (23.9 months) than with gp (16.9 months; adjusted hazard ratio vs. nabpc: 1.55; p < 0.05) and with sbpc (18.3 months; adjusted hazard ratio: 1.42; p = 0.10). No differences were observed in pfs (median pfs: 8.8, 8.0, and 7.6 months for gp, nabpc, and sbpc respectively; log-rank p = 0.76) or in td (median td: 5.5, 5.7, and 4.6 months respectively; p = 0.65). For patients who subsequently received 2L immunotherapy, no differences in os were observed (median os: 27.3, 25.0, and 23.0 months respectively; p = 0.59).

Conclusions

In a nationwide sample of scc patients, longer median os was associated with 1L nabpc than with gp and sbpc. Median os for all 1L agents considered was similar in the subgroup of patients who sequenced to a 2L immunotherapy.

PD-1/PD-L1 pathway: Basic biology and role in cancer immunotherapy

Over the course of past few years, cancer immunotherapy has been accompanied with promising results. However, preliminary investigations with respect to immunotherapy concentrated mostly on targeting the immune checkpoints, nowadays, emerge as the most efficient strategy to raise beneficial antitumor immune responses. Programmed cell death protein 1 (PD-1) plays an important role in subsiding immune responses and promoting self-tolerance through suppressing the activity of T cells and promoting differentiation of regulatory T cells. PD-1 is considered as an immune checkpoint and protects against autoimmune responses through both induction of apoptosis in antigen-specific T cells and inhibiting apoptosis in regulatory T cells. Several clinical trials exerting PD-1 monoclonal antibodies as well as other immune-checkpoint blockades have had prosperous outcomes and opened new horizons in tumor immunotherapy. Nonetheless, a bulk of patients have failed to respond to these newly emerging immune-based approach and the survival rate was not satisfying. Additional strategies, especially combination therapies, has been initiated and been further promising. Attempts to identify novel and well-suited predictive biomarkers are also sensed. In this review, the promotion of cancer immunotherapy targeting PD-1 immunoinhibitory pathway is discussed.

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration Use for Subclassification and Genotyping of Lung Non-Small-Cell Carcinoma

OBJECTIVES

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the primary method for the diagnosis and staging of lung cancer. The purpose of this study was to assess the yield of EBUS-TBNA in the subtyping and genotyping of lung adenocarcinoma.

METHODS

Sixty-nine patients at Indiana University Hospital and Sidney and Lois Eskenazi Hospital with possible or confirmed lung adenocarcinoma underwent EBUS-TBNA using a 21-gauge Olympus needle without suction. Samples were sent for molecular testing after rapid onsite specimen evaluation. A total of 6 to 10 passes were placed in a cell block.

RESULTS

Sixty-nine samples from patients with non-small-cell lung cancer were sent for molecular testing for epidermal growth factor receptor. Results were obtained in all of the patients. Mutations were found in three patients (4.3%). Fifty-eight samples were sent for V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (100% yield), 10 of which had mutations (17.2%). Fifty-one samples were sent for proto-oncogene tyrosine-protein kinase ROS testing (1 [7.8%] mutant). Tissue samples were inadequate in three patients (94.1% yield). Sixty-three samples were sent for anaplastic lymphoma receptor tyrosine kinase testing (3 [4.8%] mutant, 6 [9.5%] inadequate, 90.5% yield).

CONCLUSIONS

EBUS-TBNA with a 21-gauge needle is appropriate for the analysis of multiple mutations and the genotyping of lung adenocarcinoma.

[First-line Combination Immunotherapy in Advanced Non-small Cell Lung Cancer]

Programmed death 1/programmed death ligand 1 (PD-1/PD-L1) inhibitor has become one of the important treatment options for patients with advanced non-small cell lung cancer (NSCLC). However, only a small subset of patients with NSCLC can currently receive single-agent PD-1 inhibitors as first-line therapy, for the limitations of population selection exclude most patients from immuno-oncology (IO) monotherapy. In order to expand the candidate population for IO first-line treatment and make more newly diagnosed patients benefit from IO treatment, a series of studies are focusing on the combination of IO and other drugs in NSCLC. We reviewed the latest clinical data of IO first-line combination therapy in recent years, suggesting that on the basis of PD-1/PD-L1 inhibitors, combined with other IO, chemotherapy, anti-angiogenic drugs, targeted therapy or radiotherapy may produce synergistic anti-tumor effects. It is expected to benefit more newly diagnosed patients.
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CD147-mediated glucose metabolic regulation contributes to the predictive role of 18 F-FDG PET/CT imaging for EGFR-TKI treatment sensitivity in NSCLC

The aim of this study is to investigate the role of CD147 in glucose metabolic regulation and its association with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment sensitivity prediction using ¹⁸ F-fluorodeoxyglucose (¹⁸ F-FDG) PET/CT imaging in non-small cell lung cancer (NSCLC). In this study, four human NSCLC cell lines with different EGFR-TKI responses were used to detect p-EGFR/EGFR and CD147 expression via Western blotting and flow cytometric analyses. Radioactive uptake of ¹⁸ F-FDG by established stable NSCLC cell lines (HCC827, H1975) with different levels of CD147 expression and the corresponding xenografts was assessed through γ-radioimmunoassays in vitro and micro-PET/CT imaging in vivo to study the role of CD147 in glucose metabolic reprogramming. Correlation analyses were performed to investigate the association between CD147 expression and PD-L1 expression in stable NSCLC cell lines. Higher CD147 expression was found in EGFR-TKI-sensitive NSCLC cell lines than in relatively resistant NSCLC cell lines (HCC827>PC9>A549>H1975). CD147 could promote ¹⁸ F-FDG uptake by HCC827 and H1975 cells in vitro and in vivo through an EGFR-initiated Akt/mTOR-dependent signaling pathway. Programmed cell death-ligand 1 (PD-L1) expression was positively correlated with CD147 expression in human NSCLC cell lines. EGFR-TKI treatment sensitivity prediction in NSCLC using ¹⁸ F-FDG PET/CT imaging significantly correlated with CD147-mediated glucose metabolic regulation via the Akt/mTOR-dependent pathway. Moreover, PD-L1 expression in NSCLC cell lines could be regulated by CD147, suggesting a potential immunosuppression induced by the upregulation of tumor glucose metabolism.

Programmed cell death ligand-1 (PD-L1) expression combined with CD8 tumor infiltrating lymphocytes density in non-small cell lung cancer patients

Cancer immunotherapy targeting programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) pathway has shown promising results in treatment of non-small cell lung cancer (NSCLC) patients. T cells play a major role in tumor-associated immune response. This study aimed to investigate PD-L1 expression alone and combined with CD8 tumor infiltrating lymphocytes (TILs) density in relation to clinicopathologic parameters and survival in NSCLC patients. Immunohistochemical analysis was used to evaluate PD-L1 expression and CD8 TILs density in 55 NSCLC patients. PD-L1 immunopositivity was detected in 36 (65.5%) of NSCLC cases. PD-L1 expression was significantly related to high tumor grade (p value = 0.038) and low CD8 TILs density (p value = 0.004), whereas no significant relations were detected between PD-L1 expression and tumor stage (p value = 0.121), overall survival (OS) (p value = 0.428) and progression-free survival (PFS) (p value = 0.439). Among PD-L1/CD8 TILs density groups, PD-L1⁺/CD8^Low group was significantly associated with high tumor grade compared to PD-L1^-/CD8^high group (pairwise p = 0.016). PD-L1⁺/CD8^Low group was significantly related to advanced tumor stage compared to PD-L1⁺/CD8^high and PD-L1^-/CD8^Low groups (pairwise p = 0.001 and 0.013 respectively). PD-L1^-/CD8^high group exhibited the best OS and PFS whereas PD-L1⁺/CD8^low group had the poorest OS and PFS (p value = 0.032 and 0.001 respectively). Assessment of PD-L1 combined with CD8 TILs density, instead of PD-L1 alone, suggested important prognostic relevance in NSCLC patients.

Comparative analysis of immune checkpoint inhibitors and chemotherapy in the treatment of advanced non-small cell lung cancer: A meta-analysis of randomized controlled trials

BACKGROUND

Recently, immune checkpoint inhibitors have shown survival advantage over chemotherapy in the treatment of advanced non-small cell lung cancer (NSCLC). This meta-analysis was conducted to gather and analyze the available evidence (Evidence level I; Randomized Controlled Trials) comparing efficacy and safety of anti-programmed cell death-1 (PD1)/programmed cell death ligand 1 (PD-L1) therapies and chemotherapy in the treatment of advanced NSCLC.

METHODS

A search strategy was devised to identify the randomized controlled trials (RCTs) using electronic databases of PubMed, Cochrane Library, and Web of Science. Hazard ratios or odds ratios obtained for overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and treatment related adverse events (TRAEs) were analyzed using fixed effect model or random effects model. Additionally, subgroup analysis was also performed.

RESULTS

A total of seven RCTs (n = 3867) were identified and selected for inclusion in this meta-analysis. Anti-PD1/PD-L1 therapies (nivolumab, pembrolizumab, atezolizumab) resulted in better OS (HR 0.72 [95% confidence interval [CI] 0.63, 0.82; P < .00001]), PFS (HR 0.84 [95% CI 0.72, 0.97; P < .02]), and ORR (odds ratio [OR] 1.52 [95% CI 1.08, 2.14; P < .02]) in comparison to chemotherapy in advanced NSCLC. Improved safety was observed with anti-PD1/PD-L1 therapies (OR 0.31 [95%CI 0.26, 0.38; P < .00001]). Subgroups analysis revealed Eastern Cooperative Oncology Group Performance Status (ECOG PS) 1 (HR 0.76 [95%CI 0.62, 0.93; P = .007]), squamous cell type (HR 0.76 [95% CI 0.63, 0.92; P = .005]), current/former smoker (HR 0.76 [95% CI 0.63, 0.92; P = .005]), epidermal growth factor receptor (EGFR) wild type (HR 0.67 [95% CI 0.60, 0.76; P < .00001]), Kirsten rat sarcoma oncogene mutation (KRAS) mutant (HR 0.60 [95% CI 0.39, 0.93; P < .02]), and absence of central nervous system (CNS) metastases (HR 0.71 [95% CI 0.63, 0.80; P < .00001]) were associated with better overall survival.

CONCLUSIONS

Anti-PD1/PD-L1 therapies are safe and effective treatment option in advanced non-small cell lung cancer and can be recommended selectively.

Potential Molecular Signatures Predictive of Lung Cancer Brain Metastasis

Brain metastases are the most common tumors of the central nervous system (CNS). Incidence rates vary according to primary tumor origin, whereas the majority of the cerebral metastases arise from primary tumors in the lung (40-50%). Brain metastases from lung cancer can occur concurrently or within months after lung cancer diagnosis. Survival rates after lung cancer brain metastasis diagnosis remain poor, to an utmost of 10 months. Therefore, prevention of brain metastasis is a critical concern in order to improve survival among cancer patients. Although several studies have been made in order to disclose the genetic and molecular mechanisms associated with CNS metastasis, the precise mechanisms that govern the CNS metastasis from lung cancer are yet to be clarified. The ability to forecast, which patients have a higher risk of brain metastasis occurrence, would aid cancer management approaches to diminish or prevent the development of brain metastasis and improve the clinical outcome for such patients. In this work, we revise genetic and molecular targets suitable for prediction of lung cancer CNS disease.