Dual-responsive supramolecular photodynamic nanomedicine with activatable immunomodulation for enhanced antitumor therapy

A major challenge facing photodynamic therapy (PDT) is that the activity of the immune-induced infiltrating CD8+ T cells is subject to the regulatory T lymphocytes (Tregs), leaving the tumor at risk of recurrence and metastasis after the initial ablation. To augment the antitumor response and reprogram the immunosuppressive tumor microenvironment (TME), a supramolecular photodynamic nanoparticle (DACss) is constructed by the host-guest interaction between demethylcantharidin-conjugated β-cyclodextrin (DMC-CD) and amantadine-terminated disulfide-conjugated FFVLGGGC peptide with chlorin e6 decoration (Ad-ss-pep-Ce6) to achieve intelligent delivery of photosensitizer and immunomodulator for breast cancer treatment. The acid-labile β-carboxamide bond of DMC-CD is hydrolyzed in response to the acidic TME, resulting in the localized release of DMC and subsequent inhibition of Tregs. The guest molecule Ad-ss-pep-Ce6 can be cleaved by a high level of intracellular GSH, reducing photosensitizer toxicity and increasing photosensitizer retention in the tumor. With a significant increase in the CTL/Treg ratio, the combination of Ce6-based PDT and DMC-mediated immunomodulation adequately achieved spatiotemporal regulation and remodeling of the TME, as well as improved primary tumor and in situ lung metastasis suppression with the aid of PD-1 antibody.

Improving cancer immunotherapy via co-delivering checkpoint blockade and thrombospondin-1 downregulator

The use of checkpoint-blockade antibodies is still restricted in several malignancies due to the modest efficacy, despite considerable success in anti-tumor immunotherapy. The poor response of cancer cells to immune destruction is an essential contributor to the failure of checkpoint therapy. We hypothesized that combining checkpoint therapy with natural-product chemosensitizer could enhance immune response. Herein, a targeted diterpenoid derivative was integrated with the checkpoint blockade (anti-CTLA-4) to improve immunotherapy using thermosensitive liposomes as carriers. In vivo, the liposomes enabled the co-delivery of the two drug payloads into the tumor. Consequently, the regulatory T cell proliferation was restrained, the cytotoxic T cell infiltration was enhanced, and the profound immunotherapeutic effect was achieved. In addition, the immunotherapeutic effect of another clinically used checkpoint antibody, anti-PD-1, also benefited from the diterpenoid derivative. Of note, our mechanism study revealed that the targeted diterpenoid derivative increased the sensitivity of cancer cells to immune attack via THBS1 downregulation and the resultant destruction of THBS1-CD47 interaction. Collectively, co-delivering THBS1 inhibitor and checkpoint blockade is promising to boost cancer immunotherapy. We first time discovered that THBS1 suppression could strengthen checkpoint therapy.

Metabolic interventions combined with CTLA-4 and PD-1/PD-L1 blockade for the treatment of tumors: mechanisms and strategies / 医学前沿

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

Liver-directed treatment is associated with improved survival and increased response to immune checkpoint blockade in metastatic uveal melanoma: results from a retrospective multicenter trial / 医学前沿

Metastases of uveal melanoma (UM) spread predominantly to the liver. Due to low response rates to systemic therapies, liver-directed therapies (LDT) are commonly used for tumor control. The impact of LDT on the response to systemic treatment is unknown. A total of 182 patients with metastatic UM treated with immune checkpoint blockade (ICB) were included in this analysis. Patients were recruited from prospective skin cancer centers and the German national skin cancer registry (ADOReg) of the German Dermatologic Cooperative Oncology Group (DeCOG). Two cohorts were compared: patients with LDT (cohort A, n = 78) versus those without LDT (cohort B, n = 104). Data were analyzed for response to treatment, progression-free survival (PFS), and overall survival (OS). The median OS was significantly longer in cohort A than in cohort B (20.1 vs. 13.8 months; P = 0.0016) and a trend towards improved PFS was observed for cohort A (3.0 vs. 2.5 months; P = 0.054). The objective response rate to any ICB (16.7% vs. 3.8%, P = 0.0073) and combined ICB (14.1% vs. 4.5%, P = 0.017) was more favorable in cohort A. Our data suggest that the combination of LDT with ICB may be associated with a survival benefit and higher treatment response to ICB in patients with metastatic UM.

Mevalonate improves anti-PD-1/PD-L1 efficacy by stabilizing CD274 mRNA

Mevalonate metabolism plays an important role in regulating tumor growth and progression; however, its role in immune evasion and immune checkpoint modulation remains unclear. Here, we found that non-small cell lung cancer (NSCLC) patients with higher plasma mevalonate response better to anti-PD-(L)1 therapy, as indicated by prolonged progression-free survival and overall survival. Plasma mevalonate levels were positively correlated with programmed death ligand-1 (PD-L1) expression in tumor tissues. In NSCLC cell lines and patient-derived cells, supplementation of mevalonate significantly up-regulated the expression of PD-L1, whereas deprivation of mevalonate reduced PD-L1 expression. Mevalonate increased CD274 mRNA level but did not affect CD274 transcription. Further, we confirmed that mevalonate improved CD274 mRNA stability. Mevalonate promoted the affinity of the AU-rich element-binding protein HuR to the 3'-UTR regions of CD274 mRNA and thereby stabilized CD274 mRNA. By in vivo study, we further confirmed that mevalonate addition enhanced the anti-tumor effect of anti-PD-L1, increased the infiltration of CD8+ T cells, and improved cytotoxic function of T cells. Collectively, our findings discovered plasma mevalonate levels positively correlated with the therapeutic efficacy of anti-PD-(L)1 antibody, and provided the evidence that mevalonate supplementation could be an immunosensitizer in NSCLC.

Research progress of a new immune checkpoint inhibitor T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain in anti-tumor immunotherapy / 中国热带医学

@#The T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is an inhibitory receptor mainly expressed on active T-cells, or natural killer cells (NK cells) that activate negative stimulus signals in immune cells by combining with multiple ligands on the surface of target cells including tumor cells and infected cells. TIGIT plays an important regulatory role in the immune pathogenesis of tumors, viral infections and various autoimmune diseases by inhibiting the over activation of cells and the over secretion of proinflammatory cytokines. Recent researches show that TIGIT is highly expressed in T cells and NK cells of cancer patients, and is related to disease progression and poor clinical prognosis. Researchers try to enhance the activity of T cells or NK cells by blocking the binding of TIGIT and its ligand for therapeutic intervention. At present, there have been many reports about the use of anti-TIGIT monoclonal antibody treatment in different mouse tumor models leading to tumor regression, TIGIT has received extensive attention in cancer immunotherapy as a promising target for next generation cancer immunotherapy. Several clinical trials are currently evaluating the efficacy of anti-TIGIT monoclonal antibodies (mAbs) in patients with several cancers. The most advanced candidate, tiragolumab, has exhibited remarkable efficacy in programmed cell death ligand 1 (PD-L1)-positive non-small cell lung carcinoma (NSCLC) patients in phase Ⅱ clinical trials, in combination with PD-L1 blockade. However, the specific mechanism of TIGIT blockade remains to be fully elucidated.

Cancer-cell-intrinsic mechanisms shaping the immunosuppressive landscape of prostate cancer / 亚洲男科学杂志(英文版)

Although immunotherapy has revolutionized cancer treatment and achieved remarkable success across many different cancer types, only a subset of patients shows meaningful clinical responses. In particular, advanced prostate cancer exhibits overwhelming de novo resistance to immune checkpoint blockade therapy. This is primarily due to the immunosuppressive tumor microenvironment of prostate cancer. Therefore, it is paramount to understand how prostate cancer cell-intrinsic mechanisms promote immune evasion and foster an immunosuppressive microenvironment. Here, we review recent findings that reveal the roles of the genetic alterations, androgen receptor signaling, cancer cell plasticity, and oncogenic pathways in shaping the immunosuppressive microenvironment and thereby driving immunotherapy resistance. Based on preclinical and clinical observations, a variety of therapeutic strategies are being developed that may illuminate new paths to enhance immunotherapy efficacy in prostate cancer.

Non-alcoholic Fatty Liver Disease Affect Efficacy of Immune Checkpoint Inhibitors for Patients with Hepatocellular Carcinoma: Manifestations and Mechanisms / 肿瘤防治研究

The number of patients with the combination of non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC) is gradually increasing. In recent years, the immunotherapy has become a new effective way to treat unresectable HCC. The clinical research revealed that the NAFLD could affect the efficacy of immunotherapy treating the HCC. But the mechanism is complicated. The major routes are CD8+PD-1+T cells increasing in NAFLD cause the deficiency in cell proliferation ability; Zn64 activates the anti-tumor immune response of the CSF1; PCSK9 downregulates the LDLR level to suppress the immune response of the CD8+T cells in tumor microenvironment; loss of the immune response induces the liver damage. Researches had indicated that the combination of lenvatinib, PKCa inhibitor, PCSK9 protein inhibition, ferroptosis inducer, and HIF2a small molecule inhibitor can improve the efficacy of immune checkpoint inhibitors for NAFLD-associated hepatocellular carcinoma. This review focuses on the impact of NAFLD on tumor microenvironment and how the NAFLD affect the immune check-point inhibitor effect and to discover the exact mechanism.

Evaluation of Response to Immune Checkpoint Inhibitor Monotherapy or Combination with Chemotherapy for Patients with Advanced Non-small Cell Lung Cancer and High PD-L1 Expression / 中国肺癌杂志

BACKGROUND@#Immunotherapy represented by immune checkpoint inhibitors (ICIs) has been widely used in the treatment of lung cancer. There are controversies in clinical practice for patients with advanced non-small cell lung cancer (NSCLC) and high programmed cell death-ligand 1 (PD-L1) expression receiving ICIs monotherapy or combination chemotherapy.@*METHODS@#This study retrospectively analyzed the clinical data of 49 patients with advanced NSCLC and high PD-L1 expression. Immunohistochemistry was performed with 22C3 antibody, and the expression level of PD-L1 was evaluated according to tumor proportion score (TPS). Objective response rate (ORR) and progression free survival (PFS) were compared by groups of different clinical characteristics.@*RESULTS@#ORR of monotherapy and combination therapy group was 47.1% (8/17) and 43.8% (14/32), respectively, without statistical difference (P=0.825). The median PFS of monotherapy and combination therapy group was 8.0 months and 6.8 months, respectively, without statistical difference (P=0.502). Statistical analysis of predictors of immunotherapy for the patients showed first-line immunotherapy had better ORR than subsequent immunotherapy (12/19, 63.2% vs 10/30, 33.3%, P=0.041), however no difference in PFS. And there were no differences in ORR or PFS among groups of age, gender, smoking status, performance status (PS), pathological type, tumor size and tumor-node-metastasis (TNM) stage.@*CONCLUSIONS@#The therapeutic effect is similar between ICIs monotherapy and combination chemotherapy for patients with advanced NSCLC and high PD-L1 expression. ORR of first-line immunotherapy was better in patients with advanced NSCLC and high PD-L1 expression. The optimal treatment for this population remains further prospective clinical studies.

Immunotherapy for Lung Cancer: Mechanisms of Resistance and Response Strategy / 中国肺癌杂志

Inhibition of immune checkpoints is at the forefront of immunotherapy for lung cancer. However, a high percentage of lung cancer patients do not respond to these immunotherpy or their responses are transient, indicating the existence of immune resistance. Emerging evidence suggested that the interactions between cancer cells and immune system were continuous and dynamic. Here, we review how a range of cancer-cell-autonomous characteristics, tumor-microenvironment factors, and host-related influences account for heterogenous responses. Furthermore, with the identification of new targets of immunotherapy and development of immune-based combination therapy, we elucidate the methods might useful to overcome resistance.

A novel cyclic peptide targeting LAG-3 for cancer immunotherapy by activating antigen-specific CD8 T cell responses

PD-1 and CTLA-4 antibodies offer great hope for cancer immunotherapy. However, many patients are incapable of responding to PD-1 and CTLA-4 blockade and show low response rates due to insufficient immune activation. The combination of checkpoint blockers has been proposed to increase the response rates. Besides, antibody drugs have disadvantages such as inclined to cause immune-related adverse events and infiltration problems. In this study, we developed a cyclic peptide C25 by using Ph.D.-C7C phage display technology targeting LAG-3. As a result, C25 showed a relative high affinity with human LAG-3 protein and could effectively interfere the binding between LAG-3 and HLA-DR (MHC-II). Additionally, C25 could significantly stimulate CD8 T cell activation in human PBMCs. The results also demonstrated that C25 could inhibit tumor growth of CT26, B16 and B16-OVA bearing mice, and the infiltration of CD8 T cells was significantly increased while FOXP3 Tregs significantly decreased in the tumor site. Furthermore, the secretion of IFN- by CD8 T cells in spleen, draining lymph nodes and especially in the tumors was promoted. Simultaneously, we exploited T cells depletion models to study the anti-tumor mechanisms for C25 peptide, and the results combined with MTT assay confirmed that C25 exerted anti-tumor effects CD8 T cells but not direct killing. In conclusion, cyclic peptide C25 provides a rationale for targeting the immune checkpoint, by blockade of LAG-3/HLA-DR interaction in order to enhance anti-tumor immunity, and C25 may provide an alternative for cancer immunotherapy besides antibody drugs.

Research progress on application of the combination of radiotherapy and immune-checkpoint blockade in treatment of stage Ⅲ unresectable non-small cell lung cancer / 中华放射肿瘤学杂志

Chemoradiation has been the standard treatment of stage Ⅲ unresectable non-small cell lung cancer (NSCLC) for a long period of time. However, the clinical efficacy of chemoradiation has not been significantly improved in recent two decades. In the past 2-3 years, the role of immune-checkpoint inhibitors in metastatic NSCLC has been persistently strengthened. Moreover, the synergistic effect between radiotherapy and immune-checkpoint blockade has been conformed in pre-clinical and clinical studies. Recent clinical trials have demonstrated that the combination of radiotherapy and immune-checkpoint blockade has been proven to be more effective in the treatment of stage Ⅲ unresectable NSCLC. In this article, the latest clinical studies since 2017 regarding the application value of this combined treatment of stage Ⅲ unresectable NSCLC were summarized.

Screening responsive or resistant biomarkers of immune checkpoint inhibitors based on online databases / 医学前沿

Immune checkpoint inhibitors are a promising strategy in the treatment of cancer, especially advanced types. However, not all patients are responsive to immune checkpoint inhibitors. The response rate depends on the immune microenvironment, tumor mutational burden (TMB), expression level of immune checkpoint proteins, and molecular subtypes of cancers. Along with the Cancer Genome Project, various open access databases, including The Cancer Genome Atlas and Gene Expression Omnibus, provide large volumes of data, which allow researchers to explore responsive or resistant biomarkers of immune checkpoint inhibitors. In this review, we introduced some methodologies on database selection, biomarker screening, current progress of immune checkpoint blockade in solid tumor treatment, possible mechanisms of drug resistance, strategies of overcoming resistance, and indications for immune checkpoint inhibitor therapy.

PD-1/PD-L1 blockade in cervical cancer: current studies and perspectives / 医学前沿

Cervical cancer (CC) is the fourth most commonly diagnosed female malignancy and a leading cause of cancer-related mortality worldwide, especially in developing countries. Despite the use of advanced screening and preventive vaccines, more than half of all CC cases are diagnosed at advanced stages, when therapeutic options are extremely limited and side effects are severe. Given these circumstances, new and effective treatments are needed. In recent years, exciting progress has been made in immunotherapies, including the rapid development of immune checkpoint inhibitors. Checkpoint blockades targeting the PD-1/PD-L1 axis have achieved effective clinical responses with acceptable toxicity by suppressing tumor progression and improving survival in several tumor types. In this review, we summarize recent advances in our understanding of the PD-1/PD-L1 signaling pathway, including the expression patterns of PD-1/PD-L1 and potential PD-1/PD-L1-related therapeutic strategies for CC.

The application progress of tumor radiotherapy in combination with immune checkpoint blockade / 医学研究生学报

Nowadays, it has been widely reported that radiotherapy can synergize with immune checkpoint blockade to improve antitumor efficacy, which shows significant advantages in clinical practice. The value of radiotherapy combined with immune checkpoint blockade therapy mainly lies in three aspects: improved local tumor control, stimulation of systemic immune response to induce abscopal effect and the elimination of acquired immunological tolerance to fractionated radiotherapy. Further research shows that radiotherapy combined with multiple checkpoint blockade, costimulatory molecules agonist, checkpoint gene knockout will contribute to the improved antitumor effect of the combined treatment model. Thus, this article reviewed the immunoregulation characteristics of tumor radiotherapy as well as the application status and research progress of tumor radiotherapy in combination with immune checkpoint blockade.

Multifunctional polymeric micelle-based chemo-immunotherapy with immune checkpoint blockade for efficient treatment of orthotopic and metastatic breast cancer

Immunotherapy has become a highly promising paradigm for cancer treatment. Herein, a chemo-immunotherapy was developed by encapsulating chemotherapeutic drug doxorubicin (DOX) and Toll-like receptor 7 agonist imiquimod (IMQ) in low molecular weight heparin (LMWH)-d--tocopheryl succinate (TOS) micelles (LT). In this process, LMWH and TOS were conjugated by ester bond and they were not only served as the hydrophilic and hydrophobic segments of the carrier, but also exhibited strong anti-metastasis effect. The direct killing of tumor cells mediated by DOX-loaded micelles (LT-DOX) generated tumor-associated antigens, initiating tumor-specific immune responses in combination with IMQ-loaded micelles (LT-IMQ). Furthermore, the blockade of immune checkpoint with programmed cell death ligand 1 (PD-L1) antibody further elevated the immune responses by up-regulating the maturation of DCs as well as the ratios of CD8 CTLs/T and CD4 T/T. Therefore, such a multifunctional strategy exhibited great potential for inhibiting the growth of orthotopic and metastatic breast cancer.

Evaluation of Nivolumab Use and Factors related to Treatment Outcomes in a Cancer Center of a Top Tier General Hospital

BACKGROUND: We strived to evaluate the status of nivolumab use and associated factors on the clinical efficacy of the drug. METHODS: The study was retrospectively conducted in patients who had been administered nivolumab at least once at the cancer center of Seoul National University Hospital from June 2015 to April 2017. Data were collected from electronic medical records. A medication-use evaluation was performed based on the American Society of Health-System Pharmacists mediation-use guidelines. RESULTS: Sixty-six of the 74 patients (89.2%) showed indications approved for nivolumab use by the Korean Ministry of Food and Drug Safety (MFDS; n=55) or the US Food and Drug Administration (FDA; n=11). Approximately 73.0% of the patients were administered the approved dose of 3 mg/kg but 25.7% were administered an unapproved fixed dose of 100 mg. The overall response rate was 21.7%, and the response rate of non-small cell lung cancer patients, who accounted for the largest number of indications, was 18.8%. Adverse reactions were found in 90.1% of the patients and were mostly mild (86%). The expression of programmed death-ligand 1 (PD-L1) was analyzed as a factor affecting treatment response (p=0.028, odds ratio [OR]=11.331). CONCLUSION: PD-L1 expression was found to affect treatment response. However, caution is required while using an unapproved dosage and in the absence of monitoring for effectiveness and safety. Therefore, an effective protocol or instruction manual for the proper use of nivolumab should be considered.

PD-1/PD-L1 checkpoint blockade in immune-antitumortherapy:advances and perspectives / 中国药理学与毒理学杂志

During the past three decades, studies have shown that tumor cells could ″manipulate″host immunity to escape the immune defenses in the tumor microenvironment. One of the most important underlying mechanisms is immune-suppression regulated by programmed cell death-1 or its ligand 1 (PD- 1/ PD- L1), which makes PD- 1/PD- L1 blockadea promising target of cancer immune- therapy. Tumors could suppress immuno- response of T cells by activating PD- 1/PD- L1 signaling pathway. Therefore, inhibiting the interaction between PD-1 and PD-L1 could reconstitute the enduring antitumor immunity in the tumor microenvironment via enhancing the T-cell response, there after augmenting the endogenous antitumor force of the immune system. Along these lines, inhibitors of PD-1/PD-L1 has been applied in multiple clinical trials against various types of tumors. Recent studies indicated that PD-1/PD- L1 blockade have demonstrated high efficacy and safety against melanoma, lung, kidney and several other solid tumors, as well as hematological malignancies. Nevertheless, the efficacy of this checkpoint blockade approach is not universal. Some investigation suggested that lack of responses to anti-PD-1/PD-L1 therapy of patients without PD-1/PD-L1 over-expression was expected. In this review, we summarize the history and current understanding of multiple intrinsic and extrinsic mechanisms via which PD-1/PD-L1 is regulated and research advances in preclinical/clinical aspects of PD-1/PD-L1, as well as significance and perspectives regarding the PD-1/PD-L1 blockade in immune-antitumor therapy.

Mechanisms of cancer treatment by radiotherapy combined with immune checkpoint blockade / 国际肿瘤学杂志

With the further researches on the immune mechanisms in tumor,more and more scholars notice the phenomenon that radiation activates the immunity,and find that radiotherapy causes immunity suppression is one-sided.Although body's anti-tumor immunity can be enhanced by radiotherapy,in clinical,we observe that patients who receive radiotherapy cannot avoid tumor recurrence and metastasis.Researches show that tumor microenvironment makes the immune checkpoint pathway abnormally activated.Therefore,the combination of radiotherapy and immune checkpoint inhibitor can change the tumor microenvironment,and can improve the therapeutic effect.

Immunotherapy for Non-small-cell Lung Cancer: Current Status and Future Obstacles

Lung cancer is one of the leading causes of death worldwide. There are 2 major subtypes of lung cancer, non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). Studies show that NSCLC is the more prevalent type of lung cancer that accounts for approximately 80%–85% of cases. Although, various treatment methods, such as chemotherapy, surgery, and radiation therapy have been used to treat lung cancer patients, there is an emergent need to develop more effective approaches to deal with advanced stages of tumors. Recently, immunotherapy has emerged as a new approach to combat with such tumors. The development and success of programmed cell death 1 (PD-1)/program death-ligand 1 (PD-L1) inhibitors and cytotoxic T-lymphocyte antigen 4 (CTLA-4) blockades in treating metastatic cancers opens a new pavement for the future research. The current mini review discusses the significance of immune checkpoint inhibitors in promoting the death of tumor cells. Additionally, this review also addresses the importance of tumor-specific antigens (neoantigens) in the development of cancer vaccines and major challenges associated with this therapy. Immunotherapy can be a promising approach to treat NSCLC because it stimulates host's own immune system to recognize cancer cells. Therefore, future research should focus on the development of new methodologies to identify novel checkpoint inhibitors and potential neoantigens.