Primary and acquired resistance to PD-1/PD-L1 blockade in cancer treatment

Discovery of Pyridine-2-Carboxamides Derivatives as Potent and Selective HPK1 Inhibitors for the Treatment of Cancer

Hematopoietic progenitor kinase 1 (HPK1) has emerged as an attractive target for immunotherapy due to its critical role in T cell activation and proliferation. The major challenge in developing HPK1 inhibitors lies in balancing kinase selectivity, pharmacokinetic (PK) properties, and therapeutic efficacy. In this study, we report a series of pyridine-2-carboxamide analogues demonstrating strong HPK1 inhibitory activity in enzymatic and cellular assays, along with good kinase selectivity. Among these analogues, compound 19 showed good in vitro HPK1 inhibitory activity, excellent kinase selectivity (>637-fold vs GCK-like kinase and >1022-fold vs LCK), and robust in vivo efficacy in the CT26 (tumor growth inhibition (TGI) = 94.3%, 2/6 CRs) and MC38 murine colorectal cancer models (TGI = 83.3%, 1/6 complete response) when administered in combination with anti-PD-1. Compound 19 also demonstrated adequate in vitro ADME and in vivo PK properties, displaying good oral bioavailability across multiple species (F % = 35-63). These findings summarize our compound's favorable safety and efficacy profiles, justifying its testing in future translational studies.

The progress on the relationship between gut microbiota and immune checkpoint blockade in tumors

Immune checkpoint blockade (ICB) has emerged as a promising immunotherapeutic approach for the treatment of various tumors. However, the efficacy of this therapy is limited in a subset of patients, and it is important to develop strategies to enhance immune responses. Studies have demonstrated a critical role of gut microbiota in regulating the therapeutic response to ICB. Gut microbiota composition, diversity, and function are mediated by metabolites, such as short-chain fatty acids and secondary bile acids, that interact with host immune cells through specific receptors. In addition, gut bacteria may translocate to the tumor site and stimulate antitumor immune responses. Therefore, maintaining a healthy gut microbiota composition, for instance through avoiding the use of antibiotics or probiotic interventions, can be an effective approach to optimize ICB therapy. This review summarizes the current understanding of the microbiota-immunity interactions in the context of ICB therapy, and discusses potential clinical implications of these findings.

Contactin-4 suppresses antitumor T cell responses by engaging amyloid precursor protein

Immune checkpoint inhibitors have substantial advanced tumor treatment, but their limited benefits and strong responses in only a subset of patients remain challenging. In this study, we explored the immunomodulatory function of contactin-4 (CNTN4). CNTN4 was highly expressed in tumor tissues, and expression impaired the antitumor function of T cells. CNTN4 bound to amyloid precursor protein (APP) on T cells, which attenuated conjugation between cancer cells and T cells, and diminished T cell receptor signaling cascades. We developed an anti-CNTN4 antibody (GENA-104A16) and an anti-APP antibody (5A7) that blocked the binding between CNTN4 and APP. Administration of either GENA-104A16 or 5A7 promoted antitumor T cell responses in a syngeneic mouse model and increased tumor-infiltrating lymphocytes in vivo. Furthermore, elevated CNTN4 levels were associated with poor prognosis and negatively correlated with various cytotoxic immune-related markers. These results suggest that CNTN4-APP is an inhibitory checkpoint in T cells and represents a promising therapeutic strategy for cancer immunotherapy.

Characterization of a ferroptosis-related gene signature predicting survival and immunotherapeutic response in lung adenocarcinoma

Lung cancer remains the leading cause of cancer-related death worldwide, and drug resistance represents the main obstacle responsible for the poor mortality and prognosis. Here, to identify a novel gene signature for predicting survival and drug response, we jointly investigated RNA sequencing data of lung adenocarcinoma patients from TCGA and GEO databases, and identified a ferroptosis-related gene signature. The signature was validated in the validation set and two external cohorts. The high-risk group had a reduced survival than the low-risk group (P < 0.05). Moreover, the established gene signature was associated with tumor mutation burden, microsatellite instability, and response to immune checkpoint blockade. In addition, four candidate oncogenes (RRM2, SLC2A1, DDIT4, and VDAC2) were identified to be candidate oncogenes using in silico and wet experiments, which could serve as potential therapeutic targets. Collectively, this study developed a novel ferroptosis-related gene signature for predicting prognosis and drug response, and identified four candidate oncogenes for lung adenocarcinoma.

Tumor antigen presentation and the associated signal transduction during carcinogenesis

Numerous developments have been achieved in the study and treatment of cancer throughout the decades that it has been common. After decades of research, about 100 different kinds of cancer have been found, each with unique subgroups within certain organs. This has significantly expanded our understanding of the illness. A mix of genetic, environmental, and behavioral variables contribute to the complicated and diverse process of cancer formation. Mutations, or changes in the DNA sequence, are crucial to the development of cancer. These mutations have the ability to downregulate the expression and function of Major Histocompatibility Complex class I (MHC I) and MHCII receptors, as well as activate oncogenes and inactivate tumor suppressor genes. Cancer cells use this tactic to avoid being recognized by cytotoxic CD8+T lymphocytes, which causes issues with antigen presentation and processing. This review goes into great length into the PI3K pathway, changes to MHC I, and positive impacts of tsMHC-II on disease-free survival and overall survival and the involvement of dendritic cells (DCs) in different tumor microenvironments. The vital functions that the PI3K pathway and its link to the mTOR pathway are highlighted and difficulties in developing effective cancer targeted therapies and feedback systems has also been mentioned, where resistance mechanisms include RAS-mediated oncogenic changes and active PI3K signalling.

Homologous recombination deficiency status predicts response to immunotherapy-based treatment in non-small cell lung cancer patients

BACKGROUND

Homologous recombination deficiency (HRD) is a biomarker that predicts response to ovarian cancer treatment with poly (ADP-ribose) polymerase (PARP) inhibitors or breast cancer treatment with first-line platinum-based chemotherapy. However, there are few studies on the prognosis of lung cancer patients treated with immune checkpoint inhibitor (ICI) therapy using HRD as a biomarker.

METHODS

We studied the relationship between HRD status and the effectiveness of first-line ICI-based therapy in EGFR/ALK wild-type metastatic non-small cell lung cancer patients (NSCLC) patients.

RESULTS

This study included 22 treatment naïve NSCLC patients. The HRD score ranged from -26.37 to 92.34, with an average of 24.57. Based on analysis of the progression-free survival (PFS) data from the included NSCLC patients, threshold traversal was carried out. HRD (+) was defined as an HRD score of 31 or higher. Kaplan-Meier PFS survival analysis showed prolonged median PFS (mPFS) in NSCLC patients with HRD (+) versus HRD (-) (N/A vs. 7.0 ms, log-rank p = 0.029; HR 0.20, 95% CI: 0.04-0.96, likelihood-ratio p = 0.03). In patients with PD-L1 TPS ≥50% and HRD score ≥31 (co-status high), the mPFS was temporarily not reached during the follow-up period. In patients with PD-L1 TPS <1% and HRD score <31, the mPFS was 3 ms. Cox regression analysis showed that the hazard ratio of the co-status was 0.14 (95% CI: 0.04-0.54), which was a good prognostic factor, and the prognostic effect of co-status was better than that of HRD score alone.

CONCLUSION

The HRD status can be identified as an independent significance in NSCLC patients treated with first-line ICI-based therapy.

A phase I trial of LHC165 single agent and in combination with spartalizumab in patients with advanced solid malignancies

BACKGROUND

LHC165 is a Toll-like receptor (TLR)-7 agonist that generates an effective tumor antigen-specific T-cell adaptive immune response as well as durable antitumor responses. We aimed to evaluate the safety, tolerability, efficacy, dose-limiting toxicities, and pharmacokinetics (PK) of LHC165 single agent (SA) ± spartalizumab [PDR001; anti-programmed cell death protein 1 (PD-1)] in adult patients with advanced solid tumors.

MATERIALS AND METHODS

In this phase I/Ib, open-label, dose-escalation/expansion study, patients received LHC165 SA 100-600 μg biweekly through intratumoral (IT) injection and LHC165 600 μg biweekly + spartalizumab 400 mg Q4W through intravenous (IV) infusion.

RESULTS

Forty-five patients were enrolled: 21 patients received LHC165 SA, and 24 patients received LHC165 + spartalizumab. The median duration of exposure was 8 weeks (range 2-129 weeks). No maximum tolerated dose was reached. Recommended dose expansion was established as LHC165 600 μg biweekly as SA and in combination with spartalizumab 400 mg Q4W. The most common drug-related adverse events (AEs) were pyrexia (22.2%), pruritus (13.3%), chills (11.1%), and asthenia (4.4%). The only serious AE (SAE) suspected to be related to the study drug was grade 3 pancreatitis (n = 1). Across all tumor types, overall response rate and disease control were 6.7% and 17.8%, respectively. Overall median progression-free survival (PFS) and immune-related PFS was 1.7 months. LHC165 serum PK demonstrated an initial rapid release followed by a slower release due to continued release of LHC165 from the injection site.

CONCLUSIONS

LHC165 demonstrated acceptable safety and tolerability both as SA and in combination with spartalizumab, and evidence of limited antitumor activity was seen in adult patients with relapsed/refractory or metastatic solid tumors.

Spon1+ inflammatory monocytes promote collagen remodeling and lung cancer metastasis through lipoprotein receptor 8 signaling

Lung cancer is the leading cause of cancer-related deaths in the world, and non-small cell lung cancer (NSCLC) is the most common subset. We previously found that infiltration of tumor inflammatory monocytes (TIMs) into lung squamous carcinoma (LUSC) tumors is associated with increased metastases and poor survival. To further understand how TIMs promote metastases, we compared RNA-Seq profiles of TIMs from several LUSC metastatic models with inflammatory monocytes (IMs) of non-tumor-bearing controls. We identified Spon1 as upregulated in TIMs and found that Spon1 expression in LUSC tumors corresponded with poor survival and enrichment of collagen extracellular matrix signatures. We observed SPON1+ TIMs mediate their effects directly through LRP8 on NSCLC cells, which resulted in TGF-β1 activation and robust production of fibrillar collagens. Using several orthogonal approaches, we demonstrated that SPON1+ TIMs were sufficient to promote NSCLC metastases. Additionally, we found that Spon1 loss in the host, or Lrp8 loss in cancer cells, resulted in a significant decrease of both high-density collagen matrices and metastases. Finally, we confirmed the relevance of the SPON1/LRP8/TGF-β1 axis with collagen production and survival in patients with NSCLC. Taken together, our study describes how SPON1+ TIMs promote collagen remodeling and NSCLC metastases through an LRP8/TGF-β1 signaling axis.

The Immune Suppressor IGSF1 as a Potential Target for Cancer Immunotherapy

The development of first-generation immune-checkpoint inhibitors targeting PD-1/PD-L1 and CTLA-4 ushered in a new era in anticancer therapy. Although immune-checkpoint blockade therapies have shown clinical success, a substantial number of patients yet fail to benefit. Many studies are under way to discover next-generation immunotherapeutic targets. Immunoglobulin superfamily member 1 (IGSF1) is a membrane glycoprotein proposed to regulate thyroid function. Despite containing 12 immunoglobin domains, a possible role for IGSF1, in immune response, remains unknown. Here, our studies revealed that IGSF1 is predominantly expressed in tumors but not normal tissues, and increased expression is observed in PD-L1low non-small cell lung cancer (NSCLC) cells as compared with PD-L1high cells. Subsequently, we developed and characterized an IGSF1-specific human monoclonal antibody, WM-A1, that effectively promoted antitumor immunity and overcame the limitations of first-generation immune-checkpoint inhibitors, likely via a distinct mechanism of action. We further demonstrated high WM-A1 efficacy in humanized peripheral blood mononuclear cells (PBMC), and syngeneic mouse models, finding additive efficacy in combination with an anti-PD-1 (a well-characterized checkpoint inhibitor). These findings support IGSF1 as an immune target that might complement existing cancer immunotherapeutics.

PRMT1 Inhibition Activates the Interferon Pathway to Potentiate Antitumor Immunity and Enhance Checkpoint Blockade Efficacy in Melanoma

Despite the immense success of immune checkpoint blockade (ICB) in cancer treatment, many tumors, including melanoma, exhibit innate or adaptive resistance. Tumor-intrinsic T-cell deficiency and T-cell dysfunction have been identified as essential factors in the emergence of ICB resistance. Here, we found that protein arginine methyltransferase 1 (PRMT1) expression was inversely correlated with the number and activity of CD8+ T cells within melanoma specimen. PRMT1 deficiency or inhibition with DCPT1061 significantly restrained refractory melanoma growth and increased intratumoral CD8+ T cells in vivo. Moreover, PRMT1 deletion in melanoma cells facilitated formation of double-stranded RNA derived from endogenous retroviral elements (ERV) and stimulated an intracellular interferon response. Mechanistically, PRMT1 deficiency repressed the expression of DNA methyltransferase 1 (DNMT1) by attenuating modification of H4R3me2a and H3K27ac at enhancer regions of Dnmt1, and DNMT1 downregulation consequently activated ERV transcription and the interferon signaling. Importantly, PRMT1 inhibition with DCPT1061 synergized with PD-1 blockade to suppress tumor progression and increase the proportion of CD8+ T cells as well as IFNγ+CD8+ T cells in vivo. Together, these results reveal an unrecognized role and mechanism of PRMT1 in regulating antitumor T-cell immunity, suggesting PRMT1 inhibition as a potent strategy to increase the efficacy of ICB.

SIGNIFICANCE

Targeting PRMT1 stimulates interferon signaling by increasing expression of endogenous retroviral elements and double-stranded RNA through repression of DNMT1, which induces antitumor immunity and synergizes with immunotherapy to suppress tumor progression.

Understanding immune checkpoints and PD-1/PD-L1-mediated immune resistance towards tumour immunotherapy

Immunotherapy has emerged as a transformative approach in the treatment of various cancers, offering new hope for patients previously faced with limited treatment options. A cornerstone of cancer immunotherapy lies in targeting immune checkpoints, particularly the programmed cell death protein-1 (PD-1) and programmed death-ligand 1 (PD-L1) pathway. Immune checkpoints serve as crucial regulators of the immune response, preventing excessive immune activity and maintaining self-tolerance. PD-1, expressed on the surface of T cells, and its ligand PD-L1, expressed on various cell types, including cancer cells and immune cells, play a central role in this regulatory process. Although the success rate associated with these immunotherapies is very promising, most patients still show intrinsic or acquired resistance. Since the mechanisms related to PD-1/PD-L1 resistance are not well understood, an in-depth analysis is necessary to improve the success rate of anti-PD-1/PD-L1 therapy. Hence, here we provide an overview of PD-1, its ligand PD-L1, and the resistance mechanism towards PD-1/PD-L1. Furthermore, we have discussed the plausible solution to increase efficacy and clinical response. For the following research, joint endeavours of clinicians and basic scientists are essential to address the limitation of resistance towards immunotherapy.

Effectiveness and Safety of the PD-1 Inhibitor Lenvatinib Plus Radiotherapy in Patients with HCC with Main PVTT: Real-World Data from a Tertiary Centre

Background

Patients with hepatocellular carcinoma (HCC) with portal vein tumour thrombus (PVTT), especially type Vp-4, usually have a poor prognosis. However, the vast majority of Phase III clinical trials exclude this population based on the inclusion criteria. Lenvatinib plus a PD-1 inhibitor has shown promising antitumour activity and tolerable safety in patients with unresectable HCC in Asian populations. Radiotherapy has also demonstrated high response rates and favourable survival for HCC patients with PVTT. This study aimed to explore the preliminary clinical efficacy and safety of lenvatinib plus the PD-1 inhibitor combined with radiotherapy for HCC patients with main portal vein tumour thrombus.

Methods

Between 1 March 2018 and 31 October 2020, HCC patients with main PVTT who received lenvatinib plus a PD-1 inhibitor (pembrolizumab, nivolumab or sintilimab) combined with radiotherapy from Beijing Tsinghua Changgung Hospital in China were reviewed for eligibility. The efficacy was evaluated by the survival and PVTT response rate, and the safety was evaluated by the frequency of key adverse events (AEs).

Results

In total, 39 eligible HCC patients with type Vp-4 PVTT who received triple therapy were included in this study. The 2-year OS rate was 15.4%, which was the primary end-point of our study. The median overall survival (OS) and progression-free survival (PFS) were 9.4 months (range 2.3 to 57.1) and 4.9 months (range 1.4 to 36.1), respectively. The objective response rate (ORR) of PVTT based on mRECIST was 61.5%. AFP dropped to normal 3 months after radiotherapy and was an independent risk factor associated with OS. All AEs were controlled, and no treatment-related deaths occurred.

Conclusion

Lenvatinib plus PD-1 inhibitor combined with radiotherapy had a significant therapeutic effect and manageable AEs in HCC patients with type Vp-4 PVTT and may be a potential treatment option for advanced HCC.

In vitro CRISPR screening uncovers CRTC3 as a regulator of IFN-γ-induced ferroptosis of hepatocellular carcinoma

Interferon-gamma (IFN-γ) exerts anti-tumor effects by inducing ferroptosis. Based on CRISPR/Cas9 knockout screening targeting genome-wide protein encoding genes in HepG2 and SK-Hep-1 cell lines, we found that cAMP response element-binding protein (CREB) regulated transcription coactivator 3 (CRTC3) protects tumor cells from drug-induced ferroptosis and significantly inhibits the efficacy of IFN-γ treatment in hepatocellular carcinoma (HCC). Mechanistically, CRTC3 knockout altered tumor cell lipid patterns and increased the abundance of polyunsaturated fatty acids (PUFAs), which enables lipid peroxidation and enhances the susceptibility of HCC cells to ferroptosis inducers. To scavenge for accumulated lipid peroxides (LPO) and maintain redox equilibrium, HCC cells up-regulate SLC7A11 and glutathione peroxidase 4 (GPx4) expressions to enhance the activities of glutamate-cystine antiporter (system xc-) and LPO clearance. As IFN-γ inhibiting system xc-, simultaneous treatment with IFN-γ disrupts the compensatory mechanism, and generates a synergistic effect with CRTC3 knockout to facilitate ferroptosis. Sensitizing effects of CRTC3 depletion were confirmed using typical ferroptosis inducers, including RSL3 and erastin. Sorafeinib, a commonly used target drug in HCC, was repeatedly reported as a ferroptosis inducer. We then conducted both in vitro and vivo experiments and demonstrated that CRTC3 depletion sensitized HCC cells to sorafenib treatment. In conclusion, CRTC3 is involved in the regulation of PUFAs metabolism and ferroptosis. Targeting CRTC3 signaling in combination with ferroptosis inducers present a viable approach for HCC treatment and overcoming drug resistance.

A target map of clinical combination therapies in oncology: an analysis of clinicaltrials.gov

Combination therapies have taken center stage for cancer treatment, however, there is a lack of a comprehensive portrait to quantitatively map the current clinical combination progress. This study aims to capture clinical combination therapies of the validated FDA-approved new oncology drugs by a macro data analysis and to summarize combination mechanisms and strategies in the context of the existing literature. A total of 72 new molecular entities or new therapeutic biological products for cancer treatment approved by the FDA from 2017 to 2021 were identified, and the data on their related 3334 trials were retrieved from the database of ClinicalTrials.gov. Moreover, these sampled clinical trials were refined by activity status and combination relevance and labeled with the relevant clinical arms and drug combinations, as well as drug targets and target pairs. Combination therapies are increasingly prevalent in clinical trials of new oncology drugs. From retrospective work, existing clinical combination therapies in oncology are driven by different patterns (i.e., rational design and industry trends). The former can be represented by mechanism-based or structure-based combinations, such as targeting different domains of HER2 protein or in-series co-targeting in RAF plus MEK inhibitors. The latter is an empirically driven strategy, including redundant combinations in hot targets, such as PD-1/PD-L1, PI3K, CDK4/6, and PARP. Because of an explosion in the number of clinical trials and the resultant shortage of available patients, it is essential to rationally design drug combinations.

Combined radiotherapy and immune checkpoint inhibition for the treatment of advanced hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is one of the most common cancers and a leading cause of cancer related death worldwide. Until recently, systemic therapy for advanced HCC, defined as Barcelona Clinic Liver Cancer (BCLC) stage B or C, was limited and ineffective in terms of long-term survival. However, over the past decade, immune check point inhibitors (ICI) combinations have emerged as a potential therapeutic option for patients with nonresectable disease. ICI modulate the tumor microenvironment to prevent progression of the tumor. Radiotherapy is a crucial tool in treating unresectable HCC and may enhance the efficacy of ICI by manipulating the tumor microenvironment and decreasing tumor resistance to certain therapies. We herein review developments in the field of ICI combined with radiotherapy for the treatment of HCC, as well as look at challenges associated with these treatment modalities, and review future directions of combination therapy.

Overcoming acquired resistance to cancer immune checkpoint therapy: potential strategies based on molecular mechanisms

Immune checkpoint inhibitors (ICIs) targeting CTLA-4 and PD-1/PD-L1 to boost tumor-specific T lymphocyte immunity have opened up new avenues for the treatment of various histological types of malignancies, with the possibility of durable responses and improved survival. However, the development of acquired resistance to ICI therapy over time after an initial response remains a major obstacle in cancer therapeutics. The potential mechanisms of acquired resistance to ICI therapy are still ambiguous. In this review, we focused on the current understanding of the mechanisms of acquired resistance to ICIs, including the lack of neoantigens and effective antigen presentation, mutations of IFN-γ/JAK signaling, and activation of alternate inhibitory immune checkpoints, immunosuppressive tumor microenvironment, epigenetic modification, and dysbiosis of the gut microbiome. Further, based on these mechanisms, potential therapeutic strategies to reverse the resistance to ICIs, which could provide clinical benefits to cancer patients, are also briefly discussed.

Intracellular Adhesion Molecule-1 Improves Responsiveness to Immune Checkpoint Inhibitor by Activating CD8+ T Cells

Immune checkpoint inhibitor (ICI) clinically benefits cancer treatment. However, the ICI responses are only achieved in a subset of patients, and the underlying mechanisms of the limited response remain unclear. 160 patients with non-small cell lung cancer treated with anti-programmed cell death protein-1 (anti-PD-1) or anti-programmed death ligand-1 (anti-PD-L1) are analyzed to understand the early determinants of response to ICI. It is observed that high levels of intracellular adhesion molecule-1 (ICAM-1) in tumors and plasma of patients are associated with prolonged survival. Further reverse translational studies using murine syngeneic tumor models reveal that soluble ICAM-1 (sICAM-1) is a key molecule that increases the efficacy of anti-PD-1 via activation of cytotoxic T cells. Moreover, chemokine (CXC motif) ligand 13 (CXCL13) in tumors and plasma is correlated with the level of ICAM-1 and ICI efficacy, suggesting that CXCL13 might be involved in the ICAM-1-mediated anti-tumor pathway. Using sICAM-1 alone and in combination with anti-PD-1 enhances anti-tumor efficacy in anti-PD-1-responsive tumors in murine models. Notably, combinatorial therapy with sICAM-1 and anti-PD-1 converts anti-PD-1-resistant tumors to responsive ones in a preclinical study. These findings provide a new immunotherapeutic strategy for treating cancers using ICAM-1.

Association between CD8+ tumor-infiltrating lymphocytes and prognosis of non-small cell lung cancer patients treated with PD-1/PD-L1 inhibitors: a systematic review and meta-analysis

BACKGROUND

A meta-analysis method was used to investigate the prognostic value of CD8+ tumor-infiltrating lymphocytes (TILs) in non-small cell lung cancer (NSCLC) patients treated with PD-1/PD-L1 inhibitors.

METHODS

A database search of PubMed, Embase, Web of Science and Cochrane Library up until February 7th, 2023. A clinical study on the relationship between CD8+ TILs and PD-1/PD-L1 inhibitors in the therapeutics of NSCLC. RevMan 5.3 and StataMP 17.0 software were used for meta-analysis. The outcome indicators incorporated overall survival (OS), progression-free survival (PFS) and objective response rate (ORR).

RESULTS

Nineteen articles with 1488 patients were included. The analysis results showed that high CD8+ TILs were associated with better OS (HR=0.60, 95% CI: 0.46-0.77; P<0.0001), PFS (HR=0.68, 95% CI: 0.53-0.88; P=0.003) and ORR (OR=2.26, 95% CI: 1.52-3.36; P<0.0001) in NSCLC patients treated with PD-1/PD-L1 inhibitors. Subgroup analysis indicated that patients with high CD8+ TILs had good clinical prognostic benefits whether the location of CD8+ TILs was intratumoral or stromal, and compared with East Asian, high CD8+ TILs in Caucasians showed a better prognosis. High CD8+ TILs in peripheral blood did not improve OS (HR=0.83, 95% CI: 0.69-1.01; P=0.06) and PFS (HR=0.93, 95% CI: 0.61-1.14; P=0.76) in NSCLC patients receiving PD-1/PD-L1 inhibitors.

CONCLUSION

In spite of the location of CD8+ TILs, high densities of CD8+ TILs were predictive of treatment outcomes in NSCLC patients treated with PD-1/PD-L1 inhibitors. However, high CD8+ TILs in peripheral blood had no predictive effect.

Cancer immunotherapy with immune checkpoint inhibitors (ICIs): potential, mechanisms of resistance, and strategies for reinvigorating T cell responsiveness when resistance is acquired

Cancer is still the leading cause of death globally. The approval of the therapeutic use of monoclonal antibodies against immune checkpoint molecules, notably those that target the proteins PD-1 and PD-L1, has changed the landscape of cancer treatment. In particular, first-line PD-1/PD-L1 inhibitor drugs are increasingly common for the treatment of metastatic cancer, significantly prolonging patient survival. Despite the benefits brought by immune checkpoint inhibitors (ICIs)-based therapy, the majority of patients had their diseases worsen following a promising initial response. To increase the effectiveness of ICIs and advance our understanding of the mechanisms causing cancer resistance, it is crucial to find new, effective, and tolerable combination treatments. In this article, we addressed the potential of ICIs for the treatment of solid tumors and offer some insight into the molecular pathways behind therapeutic resistance to ICIs. We also discuss cutting-edge therapeutic methods for reactivating T-cell responsiveness after resistance has been established.

DSP-0509, a systemically available TLR7 agonist, exhibits combination effect with immune checkpoint blockade by activating anti-tumor immune effects

TLR7 is an innate immune receptor that recognizes single-stranded RNAs, and its activation leads to anti-tumor immune effects. Although it is the only approved TLR7 agonist in cancer therapy, imiquimod is allowed to be administered with topical formulation. Thus, systemic administrative TLR7 agonist is expected in terms of expanding applicable cancer types. Here, we demonstrated the identification and characterization of DSP-0509 as a novel small-molecule TLR7 agonist. DSP-0509 is designed to have unique physicochemical features that could be administered systemically with a short half-life. DSP-0509 activated bone marrow-derived dendritic cells (BMDCs) and induced inflammatory cytokines including type I interferons. In the LM8 tumor-bearing mouse model, DSP-0509 reduced tumor growth not only in subcutaneous primary lesions but also in lung metastatic lesions. DSP-0509 inhibited tumor growth in several syngeneic tumor-bearing mouse models. We found that the CD8⁺ T cell infiltration of tumor before treatment tended to be positively correlated with anti-tumor efficacy in several mouse tumor models. The combination of DSP-0509 with anti-PD-1 antibody significantly enhanced the tumor growth inhibition compared to each monotherapy in CT26 model mice. In addition, the effector memory T cells were expanded in both the peripheral blood and tumor, and rejection of tumor re-challenge occurred in the combination group. Moreover, synergistic anti-tumor efficacy and effector memory T cell upregulation were also observed for the combination with anti-CTLA-4 antibody. The analysis of the tumor-immune microenvironment by using the nCounter assay revealed that the combination of DSP-0509 with anti-PD-1 antibody enhanced infiltration by multiple immune cells including cytotoxic T cells. In addition, the T cell function pathway and antigen presentation pathway were activated in the combination group. We confirmed that DSP-0509 enhanced the anti-tumor immune effects of anti-PD-1 antibody by inducing type I interferons via activation of dendritic cells and even CTLs. In conclusion, we expect that DSP-0509, a new TLR7 agonist that synergistically induces anti-tumor effector memory T cells with immune checkpoint blockers (ICBs) and can be administered systemically, will be used in the treatment of multiple cancers.

Combining of Oncolytic Virotherapy and Other Immunotherapeutic Approaches in Cancer: A Powerful Functionalization Tactic

Oncolytic viruses have found a good place in the treatment of cancer. Administering oncolytic viruses directly or by applying genetic changes can be effective in cancer treatment through the lysis of tumor cells and, in some cases, by inducing immune system responses. Moreover, oncolytic viruses induce antitumor immune responses via releasing tumor antigens in the tumor microenvironment (TME) and affect tumor cell growth and metabolism. Despite the success of virotherapy in cancer therapies, there are several challenges and limitations, such as immunosuppressive TME, lack of effective penetration into tumor tissue, low efficiency in hypoxia, antiviral immune responses, and off-targeting. Evidence suggests that oncolytic viruses combined with cancer immunotherapy-based methods such as immune checkpoint inhibitors and adoptive cell therapies can effectively overcome these challenges. This review summarizes the latest data on the use of oncolytic viruses for the treatment of cancer and the challenges of this method. Additionally, the effectiveness of mono, dual, and triple therapies using oncolytic viruses and other anticancer agents has been discussed based on the latest findings.

Research progress of therapeutic effects and drug resistance of immunotherapy based on PD-1/PD-L1 blockade

The binding of programmed death-1 (PD-1) on the surface of T cells and PD-1 ligand 1 (PD-L1) on tumor cells can prevent the immune-killing effect of T cells on tumor cells and promote the immune escape of tumor cells. Therefore, immune checkpoint blockade targeting PD-1/PD-L1 is a reliable tumor therapy with remarkable efficacy. However, the main challenges of this therapy are low response rate and acquired resistance, so that the outcomes of this therapy are usually unsatisfactory. This review begins with the description of biological structure of the PD-1/PD-L1 immune checkpoint and its role in a variety of cells. Subsequently, the therapeutic effects of immune checkpoint blockers (PD-1 / PD-L1 inhibitors) in various tumors were introduced and analyzed, and the reasons affecting the function of PD-1/PD-L1 were systematically analyzed. Then, we focused on analyzing, sorting out and introducing the possible underlying mechanisms of primary and acquired resistance to PD-1/PD-L1 blockade including abnormal expression of PD-1/PD-L1 and some factors, immune-related pathways, tumor immune microenvironment, and T cell dysfunction and others. Finally, promising therapeutic strategies to sensitize the resistant patients with PD-1/PD-L1 blockade treatment were described. This review is aimed at providing guidance for the treatment of various tumors, and highlighting the drug resistance mechanisms to offer directions for future tumor treatment and improvement of patient prognosis.

Radiotherapy combined with immunotherapy: the dawn of cancer treatment

Radiotherapy (RT) is delivered for purposes of local control, but can also exert systemic effect on remote and non-irradiated tumor deposits, which is called abscopal effect. The view of RT as a simple local treatment has dramatically changed in recent years, and it is now widely accepted that RT can provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). Nevertheless, several points remain to be addressed such as the interaction of RT and immune system, the identification of the best schedules for combination with immunotherapy (IO), the expansion of abscopal effect and the mechanism to amplify iRT. To answer these crucial questions, we roundly summarize underlying rationale showing the whole immune landscape in RT and clinical trials to attempt to identify the best schedules of iRT. In consideration of the rarity of abscopal effect, we propose that the occurrence of abscopal effect induced by radiation can be promoted to 100% in view of molecular and genetic level. Furthermore, the “radscopal effect” which refers to using low-dose radiation to reprogram the tumor microenvironment may amplify the occurrence of abscopal effect and overcome the resistance of iRT. Taken together, RT could be regarded as a trigger of systemic antitumor immune response, and with the help of IO can be used as a radical and systemic treatment and be added into current standard regimen of patients with metastatic cancer.

Signal pathways and precision therapy of small-cell lung cancer

Small-cell lung cancer (SCLC) encounters up 15% of all lung cancers, and is characterized by a high rate of proliferation, a tendency for early metastasis and generally poor prognosis. Most of the patients present with distant metastatic disease at the time of clinical diagnosis, and only one-third are eligible for potentially curative treatment. Recently, investigations into the genomic make-up of SCLC show extensive chromosomal rearrangements, high mutational burden and loss-of-function mutations of several tumor suppressor genes. Although the clinical development of new treatments for SCLC has been limited in recent years, a better understanding of oncogenic driver alterations has found potential novel targets that might be suitable for therapeutic approaches. Currently, there are six types of potential treatable signaling pathways in SCLC, including signaling pathways targeting the cell cycle and DNA repair, tumor development, cell metabolism, epigenetic regulation, tumor immunity and angiogenesis. At this point, however, there is still a lack of understanding of their role in SCLC tumor biology and the promotion of cancer growth. Importantly optimizing drug targets, improving drug pharmacology, and identifying potential biomarkers are the main focus and further efforts are required to recognize patients who benefit most from novel therapies in development. This review will focus on the current learning on the signaling pathways, the status of immunotherapy, and targeted therapy in SCLC.

Poorly differentiated thyroid carcinoma: a clinician's perspective

Poorly differentiated thyroid carcinoma (PDTC) is a rare thyroid carcinoma originating from follicular epithelial cells. No explicit consensus can be achieved to date due to sparse clinical data, potentially compromising the outcomes of patients. In this comprehensive review from a clinician's perspective, the epidemiology and prognosis are described, diagnosis based on manifestations, pathology, and medical imaging are discussed, and both traditional and emerging therapeutics are addressed as well. Turin consensus remains the mainstay diagnostic criteria for PDTC, and individualized assessments are decisive for treatment option. The prognosis is optimal if complete resection is performed at early stage but dismal in nearly half of patients with locally advanced and/or distant metastatic diseases, in which adjuvant therapies such as 131I therapy, external beam radiation therapy, and chemotherapy should be incorporated. Emerging therapeutics including molecular targeted therapy, differentiation therapy, and immunotherapy deserve further investigations to improve the prognosis of PDTC patients with advanced disease.

CMTM6 as a master regulator of PD-L1

Immune checkpoint proteins, such as programmed cell death receptor 1 (PD-1) and its ligand (PD-L1), play critical roles in the pathology of chronic inflammatory pathological conditions, particularly cancer. In addition, the activation of PD-1/PD-L1 pathway is involved in mediating resistance to certain anti-cancer chemo- and immuno-therapeutics. Unfortunately, targeting the PD-1/PD-L1 pathway by the available anti-PD-1/PD-L1 drugs can benefit only a small proportion of cancer patients. Thus, studying the factors that regulate the expression of these immune checkpoint proteins is of central importance in this context. Recent investigations have identified CMTM6 and, to a lesser extent, CMTM4, as master regulators of PD-L1 expression in various cancer cells. Understanding the mechanisms by which such proteins upregulate the expression of PD-L1 in tumor cells, and determining the potential regulators of CMTM6 expression in different types of cancers will accelerate the development of new therapeutic targets and/or lead to the enhancement of the currently available PD-1/PD-L1 blockade therapies.

LINC00244 suppresses cell growth and metastasis in hepatocellular carcinoma by downregulating programmed cell death ligand 1

The role of programmed cell death ligand 1 (PD-L1) in suppressing antitumor immune responses has been widely reported, and recent studies showed that PD-L1 also plays an important role in epithelial-mesenchymal transition (EMT), determination of tumor cell phenotypes, metastasis, and drug resistance. Long non-coding RNAs (lncRNAs) are involved in a variety of epigenetic regulatory processes. The tumorigenesis and development of most cancers cannot be studied separately from their regulation by lncRNAs. To explore the epigenetic regulation of PD-L1, we identified an lncRNA, LINC00244, which reduced PD-L1 expression and predicted good clinical outcomes in hepatocellular carcinoma (HCC). LINC00244 inhibited the proliferation, invasion, and metastasis of HCC by downregulating PD-L1 expression. In addition, low LINC00244 expression activated epithelial-mesenchymal transition (EMT) pathways and facilitated the rapid growth and metastasis of HCC cells. Thus, LINC00244 is a potential therapeutic target for HCC.

Functions of non-coding RNAs in regulating cancer drug targets

With the development of precision medicine, the efficiency of tumor treatment has been significantly improved. More attention has been paid to targeted therapy and immunotherapy as the key to precision treatment of cancer. Targeting epidermal growth factor receptor (EGFR) has become one of the most important targeted treatments for various cancers. Comparing with traditional chemotherapy drugs, targeting EGFR is highly selective in killing tumor cells with better safety, tolerability and less side effect. In addition, tumor immunotherapy has become the fourth largest tumor therapy after surgery, radiotherapy and chemotherapy, especially immune checkpoint inhibitors. However, these treatments still produce a certain degree of drug resistance. Non-coding RNAs (ncRNAs) were found to play a key role in carcinogenesis, treatment and regulation of the efficacy of anticancer drugs in the past few years. Therefore, in this review, we aim to summarize the targeted treatment of cancers and the functions of ncRNAs in cancer treatment.

APLNR regulates IFN-γ signaling via β-arrestin 1 mediated JAK-STAT1 pathway in melanoma cells

The apelin receptor (APLNR) regulates many biological processes including metabolism, angiogenesis, circulating blood volume and cardiovascular function. Additionally, APLNR is overexpressed in various types of cancer and influences cancer progression. APLNR is reported to regulate tumor recognition during immune surveillance by modulating the IFN-γ response. However, the mechanism of APLNR crosstalk with intratumoral IFN-γ signaling remains unknown. Here, we show that activation of APLNR upregulates IFN-γ signaling in melanoma cells through APLNR mediated β-arrestin 1 but not β-arrestin 2 recruitment. Our data suggests that β-arrestin 1 directly interacts with STAT1 to inhibit STAT1 phosphorylation to attenuate IFN-γ signaling. The APLNR mutant receptor, I109A, which is deficient in β-arrestins recruitment, is unable to enhance intratumoral IFN-γ signaling. While APLNR N112G, a constitutively active mutant receptor, increases intratumoral sensitivity to IFN-γ signaling by enhancing STAT1 phosphorylation upon IFN-γ exposure. We also demonstrate in a co-culture system that APLNR regulates tumor survival rate. Taken together, our findings reveal that APLNR modulates IFN-γ signaling in melanoma cells and suggests that APLNR may be a potential target to enhance the efficacy of immunotherapy.

A strategy for the efficient construction of anti-PD1-based bispecific antibodies with desired IgG-like properties

Targeting PD1/PDL1 with blocking antibodies for cancer therapy has shown promising benefits in the clinic, but only approximately 20-30% of patients develop durable clinical responses to the treatment. Bispecific antibodies (BsAbs) that combine PD1/PDL1 blockade with the modulation of another immune checkpoint target may have greater potential to enhance immune checkpoint blockade therapy. In this study, we identified an anti-PD1 monoclonal antibody, 609A, whose heavy chain can pair with a variety of light chains from different antibodies while maintaining its PD1 binding/blocking activity. Taking advantage of this property and using a linear F(ab')₂ format, we successfully produced a series of tetravalent IgG-like BsAbs that simultaneously target PD1 and other immune checkpoint targets, including PDL1 and CTLA4. The BsAbs exhibited superior bioactivities in vitro and in vivo compared to their respective parental mAbs. Importantly, the BsAbs demonstrated the desired IgG-like physicochemical properties in terms of high-level expression, ease of purification to homogeneity, good stability and in vivo pharmacokinetics. In summary, we describe a novel and flexible plug-and-play platform to engineer IgG-like BsAbs with excellent development potential for clinical applications.

Optimal subsequent treatments for patients with hepatocellular carcinoma resistant to anti-PD-1 treatment

Aim: The subsequent treatments for patients with hepatocellular carcinoma (HCC) resistant to immunotherapy remain unclear. This study aimed to identify optimal treatments for HCC patients with progression after anti-PD-1 therapy. Methods: The authors retrospectively analyzed 197 HCC patients with progressive disease after anti-PD-1 treatment. These patients were classified into initial resistant and secondary resistant groups. Results: In the initial resistant group, subsequent treatment with PD-1 antibody plus locoregional therapy prolonged post-progression survival and overall survival (p = 0.025 and 0.029, respectively). In the secondary resistant group, subsequent treatment did not improve the prognosis of patients. Conclusion: Subsequent PD-1 antibody plus locoregional therapy could achieve survival benefits in HCC patients initially resistant to anti-PD-1 immunotherapy.

Fibrinogen-like protein 1 (FGL1): the next immune checkpoint target

Immune checkpoint therapy has achieved significant efficacy by blocking inhibitory pathways to release the function of T lymphocytes. In the clinic, anti-programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) monoclonal antibodies (mAbs) have progressed to first-line monotherapies in certain tumor types. However, the efficacy of anti-PD-1/PD-L1 mAbs is still limited due to toxic side effects and de novo or adaptive resistance. Moreover, other immune checkpoint target and biomarkers for therapeutic response prediction are still lacking; as a biomarker, the PD-L1 (CD274, B7-H1) expression level is not as accurate as required. Hence, it is necessary to seek more representative predictive molecules and potential target molecules for immune checkpoint therapy. Fibrinogen-like protein 1 (FGL1) is a proliferation- and metabolism-related protein secreted by the liver. Multiple studies have confirmed that FGL1 is a newly emerging checkpoint ligand of lymphocyte activation gene 3 (LAG3), emphasizing the potential of targeting FGL1/LAG3 as the next generation of immune checkpoint therapy. In this review, we summarize the substantial regulation mechanisms of FGL1 in physiological and pathological conditions, especially tumor epithelial to mesenchymal transition, immune escape and immune checkpoint blockade resistance, to provide insights for targeting FGL1 in cancer treatment.

Anti-Angiogenic Treatments Interact with Steroid Secretion in Inflammatory Breast Cancer Triple Negative Cell Lines

Human inflammatory breast cancer (IBC) is a highly angiogenic disease for which antiangiogenic therapy has demonstrated only a modest response, and the reason for this remains unknown. Thus, the purpose of this study was to determine the influence of different antiangiogenic therapies on in vitro and in vivo steroid hormone and angiogenic growth factor production using canine and human inflammatory breast carcinoma cell lines as well as the possible involvement of sex steroid hormones in angiogenesis. IPC-366 and SUM149 cell lines and xenotransplanted mice were treated with different concentrations of VEGF, SU5416, bevacizumab and celecoxib. Steroid hormone (progesterone, dehydroepiandrostenedione, androstenedione, testosterone, dihydrotestosterone, estrone sulphate and 17β-oestradiol), angiogenic growth factors (VEGF-A, VEGF-C and VEGF-D) and IL-8 determinations in culture media, tumour homogenate and serum samples were assayed by EIA. In vitro, progesterone- and 17β-oestradiol-induced VEGF production promoting cell proliferation and androgens are involved in the formation of vascular-like structures. In vivo, intratumoural testosterone concentrations were augmented and possibly associated with decreased metastatic rates, whereas elevated E1SO4 concentrations could promote tumour progression after antiangiogenic therapies. In conclusion, sex steroid hormones could regulate the production of angiogenic factors. The intratumoural measurement of sex steroids and growth factors may be useful to develop preventive and individualized therapeutic strategies.

Mechanisms of primary and acquired resistance to PD-1/PD-L1 blockade and the emerging role of gut microbiome

As a very promising immunotherapy, PD-1/PD-L1 blockade has revolutionized the treatment of a variety of tumor types, resulting in significant clinical efficacy and lasting responses. However, these therapies do not work for a large proportion of patients initially, which is called primary resistance. And more frustrating is that most patients eventually develop acquired resistance after an initial response to PD-1/PD-L1 blockade. The mechanisms that lead to primary and acquired resistance to PD-1/PD-L1 inhibition have remained largely unclear. Recently, the gut microbiome has emerged as a potential regulator for PD-1/PD-L1 blockade. This review elaborates on the current understanding of the mechanisms in terms of PD-1 related signaling pathways and necessary factors. Moreover, this review discusses new strategies to increase the efficacy of immunotherapy from the perspectives of immune markers and gut microbiome.

Mechanisms of PD-L1 Regulation in Malignant and Virus-Infected Cells

Programmed cell death protein 1 (PD-1), a receptor on T cells, and its ligand, PD-L1, have been a topic of much interest in cancer research. Both tumour and virus-infected cells can upregulate PD-L1 to suppress cytotoxic T-cell killing. Research on the PD-1/PD-L1 axis has led to the development of anti-PD-1/PD-L1 immune checkpoint blockades (ICBs) as promising cancer therapies. Although effective in some cancer patients, for many, this form of treatment is ineffective due to a lack of immunogenicity in the tumour microenvironment (TME). Despite the development of therapies targeting the PD-1/PD-L1 axis, the mechanisms and pathways through which these proteins are regulated are not completely understood. In this review, we discuss the latest research on molecules of inflammation and innate immunity that regulate PD-L1 expression, how its expression is regulated during viral infection, and how it is modulated by different cancer therapies. We also highlight existing research on the development of different combination therapies with anti-PD-1/PD-L1 antibodies. This information can be used to develop better cancer immunotherapies that take into consideration the pathways involved in the PD-1/PD-L1 axis, so these molecules do not reduce their efficacy, which is currently seen with some cancer therapies. This review will also assist in understanding how the TME changes during treatment, which will provide further rationale for combination therapies.

Decreased expression of ARID1A invasively downregulates the expression of ribosomal proteins in hepatocellular carcinoma

Background: There was increasing evidence showing that ARID1A alterations correlated with higher tumor mutational burden, but there were limited studies focusing on the adaptive mechanisms for tumor cells to survive under excessive genomic alterations. Materials & methods: To further explore the adaptive mechanisms under ARID1A alterations, we performed RNA sequencing in ARID1A knockdown hepatocellular carcinoma cell lines, and demonstrated that decreased expression of ARID1A controlled global ribosomal proteins synthesis. The results were further confirmed by quantitative reverse transcription-PCR and bioinformatic analysis in The Cancer Genome Atlas Liver Hepatocellular Carcinoma database. Conclusion: The present study was the first to demonstrate that ARID1A might be involved in the translation pathway and served as an adaptive mechanism for tumor cells to survive under stress.

Clinic-Pathological Characteristics and Prognostic Value of PD-L1 and HER2 in Gastric Cancer

The aim of this study is to study the relationship between programmed cell death-1 ligand (PD-L1) and human epidermal growth receptor 2 (HER2) and the clinical-pathological features of gastric cancer (GC) and its predictive effect on the prognosis of gastric cancer (GC) patients. A retrospective analysis was performed on 113 patients undergoing GC surgery. The expression of PD-L1 and HER2 in GC and paired adjacent nontumor tissues was detected by immunohistochemistry or fluorescence in situ hybridization, and the relationships between PD-L1 and HER2 expression and clinical-pathological features and survival were analyzed by chi-square analysis, Pearson analysis, logistic regression analysis, Kaplan-Meier analysis, and Cox regression model. PD-L1 and HER2 were expressed in tumor tissues, but not in adjacent nontumor tissues. There was no correlation between the expression of PD-L1 and HER2. The expression of PD-L1 in GC was closely related to gender (p = 0.019), regional lymph node (p = 0.006), metastasis (p = 0.033), and survival status (p = 0.033), while HER2 was closely related to tumor differentiation (p = 0.033), regional lymph node (p = 0.016), and tumor-node-metastasis (TNM) stage (p = 0.036). The survival time of PD-L1-positive patients was longer than that of PD-L1-negative patients (p = 0.020). The expression of HER2 showed no difference in overall survival (p = 0.125). Multivariate analysis suggested that the TNM stage (p = 0.001) and PD-L1 expression (p = 0.047) were independent prognostic factors for survival time of GC. The expression of PD-L1 has biological significance in GC, which is closely related to the clinical-pathological characteristics and prognosis of GC patients.

From Conventional to Precision Therapy in Canine Mammary Cancer: A Comprehensive Review

Canine mammary tumors (CMTs) are the most common neoplasm in intact female dogs. Canine mammary cancer (CMC) represents 50% of CMTs, and besides surgery, which is the elective treatment, additional targeted and non-targeted therapies could offer benefits in terms of survival to these patients. Also, CMC is considered a good spontaneous intermediate animal model for the research of human breast cancer (HBC), and therefore, the study of new treatments for CMC is a promising field in comparative oncology. Dogs with CMC have a comparable disease, an intact immune system, and a much shorter life span, which allows the achievement of results in a relatively short time. Besides conventional chemotherapy, innovative therapies have a large niche of opportunities. In this article, a comprehensive review of the current research in adjuvant therapies for CMC is conducted to gather available information and evaluate the perspectives. Firstly, updates are provided on the clinical-pathological approach and the use of conventional therapies, to delve later into precision therapies against therapeutic targets such as hormone receptors, tyrosine kinase receptors, p53 tumor suppressor gene, cyclooxygenases, the signaling pathways involved in epithelial-mesenchymal transition, and immunotherapy in different approaches. A comparison of the different investigations on targeted therapies in HBC is also carried out. In the last years, the increasing number of basic research studies of new promising therapeutic agents on CMC cell lines and CMC mouse xenografts is outstanding. As the main conclusion of this review, the lack of effort to bring the in vitro studies into the field of applied clinical research emerges. There is a great need for well-planned large prospective randomized clinical trials in dogs with CMC to obtain valid results for both species, humans and dogs, on the use of new therapies. Following the One Health concept, human and veterinary oncology will have to join forces to take advantage of both the economic and technological resources that are invested in HBC research, together with the innumerable advantages of dogs with CMC as a spontaneous animal model.

TIGIT/PVR and LncRNA ANRIL dual-targetable PAMAM polymeric nanoparticles efficiently inhibited the hepatoma carcinoma by combination of immunotherapy and gene therapy

Herein, a novel polymeric nanoparticle was designed to inhibit hepatoma carcinoma by simultaneously targeting the T cell immunoreceptor with Ig and ITIM domains (TIGIT)/poliovirus receptor (PVR) and long noncoding RNAs antisense noncoding RNA in the INK4 locus (LncRNA ANRIL). Firstly, the siANRIL-loaded nanoparticles (NP-siANRIL) was developed by methoxy-poly (ethylene glycol)-polyamidoamine (mPEG-PAMAM) and polyamidoamine-poly (ethylene glycol)-disulphide bond-carboxyl (PAMAM-PEG-S₂-COOH) using the self-assembly method. Then the ^DTBP-3 peptide, a newly developed identified peptide which could occupy the binding interface and effectively block the interaction of TIGIT with its ligand PVR, was further conjugated on the surface of NP-siANRIL via the glutathione (GSH)-sensitive disulphide linkage. In this way, the binding ability of ^DTBP-3 to TIGIT was remained once they were entrapped into the tumour tissues which were abundant of GSH. The present study demonstrated that ^DTBP-3NP-siANRIL exhibited an excellent anti-tumour effect on hepatoma carcinoma in vivo by simultaneously inhibited the expression of miR-203a and its downstream genes and increased the percentages of NK cells and T cells. In a word, the present study has presented a novel strategy for treatment of hepatoma carcinoma by simultaneously targeting of TIGIT/PVR and LncRNA ANRIL.

An integrative pan-cancer analysis of COPB1 based on data mining

BACKGROUND

Cancer will become the leading cause of death worldwide in the 21st century, meanwhile, immunotherapy is the most popular cancer treatment method in recent years. COPI Coat Complex Subunit Beta 1 (COPB1) relates to human innate immunity. However, the role of COPB1 in pan-cancer remains unclear.

OBJECTIVE

The purpose of this study was to explore the relationship between COPB1 mRNA expression and tumor infiltrating lymphocytes and immune examination sites in pan-cancer.

METHODS

Data from multiple online databases were collected. The BioGPS, UALCAN Database, COSMIC, cBioPortal, Cancer Regulome tools, Kaplan-Meier Plotter and TIMER website were utilized to perform the analysis.

RESULTS

Upregulation of COPB1 has been widely observed in tumor tissues compared with normal tissues. Although COPB1 has poor prognosis in pan-cancer, COPB1 high expression was beneficial to the survival of ESCA patients. Unlike ESCA, COPB1 expression in STAD was positively correlated with tumor infiltrating lymphocytes, including B cells, CD8+ T cells, neutrophils, macrophages, and dendritic cells. Finally, we also found that the expression of COPB1 in STAD was positively correlated with PD-L1 and CTLA4.

CONCLUSIONS

COPB1 may be a prognostic biomarker for pan-carcinoma, and also provide an immune anti-tumor strategy for STAD based on the expression of COPB1.

Clinical Proteomics of Metastatic Melanoma Reveals Profiles of Organ Specificity and Treatment Resistance

PURPOSE

Treatment of metastatic melanoma has dramatically improved in recent years, thanks to the development of immunotherapy and BRAF-MEK-targeted therapies. However, these developments revealed marked heterogeneity in patient response, which is yet to be fully understood. In this work, we aimed to associate the proteomic profiles of metastatic melanoma with the patient clinical information, to identify protein correlates with metastatic location and prior treatments.

EXPERIMENTAL DESIGN

We performed mass spectrometry-based proteomic analysis of 185 metastatic melanoma samples and followed with bioinformatics analysis to examine the association of metastatic location, BRAF status, survival, and immunotherapy response with the tumor molecular profiles.

RESULTS

Bioinformatics analysis showed a high degree of functional heterogeneity associated with the site of metastasis. Lung metastases presented higher immune-related proteins, and higher mitochondrial-related processes, which were shown previously to be associated with better immunotherapy response. In agreement, epidemiological analysis of data from the National Cancer Database showed improved response to anti-programmed death 1, mainly in patients with lung metastasis. Focus on lung metastases revealed prognostic and molecular heterogeneity and highlighted potential tissue-specific biomarkers. Analysis of the BRAF mutation status and prior treatments with MAPK inhibitors proposed the molecular basis of the effect on immunotherapy response and suggested coordinated combination of immunotherapy and targeted therapy may increase treatment efficacy.

CONCLUSIONS

Altogether, the proteomic data provided novel molecular determinants of critical clinical features, including the effects of sequential treatments and metastatic locations. These results can be the basis for development of site-specific treatments toward treatment personalization.

Effect of radiotherapy on T cell and PD-1 / PD-L1 blocking therapy in tumor microenvironment

Cancer is a worldwide problem that threatens human health. Radiotherapy plays an important role in a variety of cancer treatment methods. The administration of radiotherapy can alter the differentiation pathways and functions of T cells, which in turn improves the immune response of T cells. Radiotherapy can also induce up-regulation of PD-L1 expression, which means that it has great potential for enhancing the therapeutic effect of anti-PD-1/PD-L1 inhibitors and reducing the risk of drug resistance toward them. At present, the combination of radiotherapy and anti-PD-1/PD-L1 inhibitors has shown significant therapeutic effects in clinical tumor research. This review focuses on the mechanism of radiotherapy on T cells reported in recent years, as well as related research progress in the application of PD-1/PD-L1 blockers. It will provide a theoretical basis for the rational clinical application of radiotherapy combined with PD-1/PD-L1 inhibitors.

Emerging role of SWI/SNF complex deficiency as a target of immune checkpoint blockade in human cancers

Mammalian SWI/SNF complex is a key chromatin remodeler that reshapes nucleosomes and regulates DNA accessibility. Mutations in SWI/SNF subunits are found in a broad spectrum of human cancers; however, the mechanisms of how these aberrations of SWI/SNF complex would impact tumorigenesis and cancer therapeutics remain to be elucidated. Studies have demonstrated that immune checkpoint blockade (ICB) therapy is promising in cancer treatment. Nevertheless, suitable biomarkers that reliably predict the clinical response to ICB are still lacking. Emerging evidence has suggested that SWI/SNF components play novel roles in the regulation of anti-tumor immunity, and SWI/SNF deficiency can be therapeutically targeted by ICB. These findings manifest the prominence of the SWI/SNF complex as a stratification biomarker that predicts treatment (therapeutic) response to ICB. In this review, we summarize the recent advances in ICB therapy by harnessing the cancer-specific vulnerability elicited by SWI/SNF deficiency. We provide novel insights into a comprehensive understanding of the underlying mechanisms by which SWI/SNF functions as a modulator of anti-tumor immunity.

Prognostic role of stromal tumor-infiltrating lymphocytes in locally advanced upper tract urothelial carcinoma: A retrospective multicenter study (TSU-02 study)

Locally advanced upper urinary tract urothelial carcinoma (UTUC) exhibits high recurrence and metastasis rates even after radical nephroureterectomy. Adjuvant immunotherapy can be a reasonable option, and a simple, low-cost, and effective biomarker is further needed. Stromal tumor-infiltrating lymphocytes (sTILs) has been demonstrated as a prognostic and predictive biomarker in various tumor types, but not yet in locally advanced UTUC. In this multicenter, real-world and retrospective study, we tried to investigate the prognostic role of sTIL and its correlation with the PD-L1/PD-1/CD8 axis by reviewing the clinicopathologic variables of 398 locally advanced UTUC patients at four high-volume Chinese medical centers. sTIL density was evaluated with standardized methodology on H&E sections, and patients were stratified by the cutoff of sTIL (50%). Results showed that high sTIL indicated improved survival (CSS, p = .022; RFS, p = .015; DFS, p = .004), and was an independent predictor of better CSS (HR, 0.577; 95% CI, 0.391–0.851; p = .006), RFS (HR, 0.613; 95% CI 0.406–0.925; p = .020) and DFS (HR, 0.609; 95% CI, 0.447–0.829; p = .002). A strongly positive correlation between sTIL density and the expression level of PD-1/PD-L1/CD8 axis was observed. We also found that aristolochic acid (AA) exposure was associated with increased sTIL and elevated PD-L1 expression, indicating that AA-related UTUC might be a distinct subgroup with unique tumor microenvironment characteristics. Our results show that sTIL can be an easily acquired biomarker for prognostic stratification in locally advanced UTUC.

Cancer Immunotherapy and Application of Nanoparticles in Cancers Immunotherapy as the Delivery of Immunotherapeutic Agents and as the Immunomodulators

Simple Summary

Cancer becomes one of the major public health problems globally and the burden is expected to be increasing. Currently, both the medical and research communities have attempted an approach to nonconventional cancer therapies that can limit damage or loss of healthy tissues and be able to fully eradicate the cancer cells. In the last few decades, cancer immunotherapy becomes an important tactic for cancer treatment. Immunotherapy of cancer must activate the host’s anti-tumor response by enhancing the innate immune system and the effector cell number, while, minimizing the host’s suppressor mechanisms. However, many immunotherapies are still limited by poor therapeutic targeting and unwanted side effects. Hence, a deeper understanding of tumor immunology and antitumor immune responses is essential for further improvement of cancer immunotherapy. In addition, effective delivery systems are required to deliver immunotherapeutic agents to the site of interest (such as: to Tumor microenvironments, to Antigen-Presenting Cells, and to the other immune systems) to enhance their efficacy by minimizing off-targeted and unwanted cytotoxicity.

Abstract

In the last few decades, cancer immunotherapy becomes an important tactic for cancer treatment. However, some immunotherapy shows certain limitations including poor therapeutic targeting and unwanted side effects that hinder its use in clinics. Recently, several researchers are exploring an alternative methodology to overcome the above limitations. One of the emerging tracks in this field area is nano-immunotherapy which has gone through rapid progress and revealed considerable potentials to solve limitations related to immunotherapy. Targeted and stimuli-sensitive biocompatible nanoparticles (NPs) can be synthesized to deliver immunotherapeutic agents in their native conformations to the site of interest to enhance their antitumor activity and to enhance the survival rate of cancer patients. In this review, we have discussed cancer immunotherapy and the application of NPs in cancer immunotherapy, as a carrier of immunotherapeutic agents and as a direct immunomodulator.

Anti-PD1 therapy induces lymphocyte-derived exosomal miRNA-4315 release inhibiting Bim-mediated apoptosis of tumor cells

Anti-PD1 immunotherapy, as a single agent or in combination with standard chemotherapies, has significantly improved the outcome of many patients with cancers. However, resistance to anti-PD1 antibodies often decreases the long-term therapeutic benefits. Despite this observation in clinical practice, the molecular mechanisms associated with resistance to anti-PD1 antibody therapy have not yet been elucidated. To identify the mechanisms of resistance associated with anti-PD1 antibody therapy, we developed cellular models including purified T cells and different cancer cell lines from glioblastoma, lung adenocarcinoma, breast cancer and ovarian carcinoma. A murine model of lung cancer was also used. Longitudinal blood samples of patients treated with anti-PD1 therapy were also used to perform a proof-of-concept study of our findings. We found that anti-PD1 exposure of T-cell promotes an enrichment of exosomal miRNA-4315. We also noted that exosomal miRNA-4315 induced a phenomenon of apopto-resistance to conventional chemotherapies in cancer cells receiving exosomal miRNA-4315. At molecular level, we discern that the apopto-resistance phenomenon was associated with the miRNA-4315-mediated downregulation of Bim, a proapoptotic protein. In cellular and mice models, we observed that the BH3 mimetic agent ABT263 circumvented this resistance. A longitudinal study using patient blood showed that miRNA-4315 and cytochrome c can be used to define the time period during which the addition of ABT263 therapy may effectively increase cancer cell death and bypass anti-PD1 resistance.This work provides a blood biomarker (exosomal miRNA-4315) for patient stratification developing a phenomenon of resistance to anti-PD1 antibody therapy and also identifies a therapeutic alternative (the use of a BH3 mimetic drug) to limit this resistance phenomenon.

Primary and Acquired Resistance to Immunotherapy in Lung Cancer: Unveiling the Mechanisms Underlying of Immune Checkpoint Blockade Therapy

After several decades without maintained responses or long-term survival of patients with lung cancer, novel therapies have emerged as a hopeful milestone in this research field. The appearance of immunotherapy, especially immune checkpoint inhibitors, has improved both the overall survival and quality of life of patients, many of whom are diagnosed late when classical treatments are ineffective. Despite these unprecedented results, a high percentage of patients do not respond initially to treatment or relapse after a period of response. This is due to resistance mechanisms, which require understanding in order to prevent them and develop strategies to overcome them and increase the number of patients who can benefit from immunotherapy. This review highlights the current knowledge of the mechanisms and their involvement in resistance to immunotherapy in lung cancer, such as aberrations in tumor neoantigen burden, effector T-cell infiltration in the tumor microenvironment (TME), epigenetic modulation, the transcriptional signature, signaling pathways, T-cell exhaustion, and the microbiome. Further research dissecting intratumor and host heterogeneity is necessary to provide answers regarding the immunotherapy response and develop more effective treatments for lung cancer.