FBXO38 is dispensable for PD-1 regulation.

SKP1-CUL1-F-box protein (SCF) ubiquitin ligases are versatile protein complexes that mediate the ubiquitination of protein substrates. The direct substrate recognition relies on a large family of F-box-domain-containing subunits. One of these substrate receptors is FBXO38, which is encoded by a gene found mutated in families with early-onset distal motor neuronopathy. SCFFBXO38 ubiquitin ligase controls the stability of ZXDB, a nuclear factor associated with the centromeric chromatin protein CENP-B. Loss of FBXO38 in mice results in growth retardation and defects in spermatogenesis characterized by deregulation of the Sertoli cell transcription program and compromised centromere integrity. Moreover, it was reported that SCFFBXO38 mediates the degradation of PD-1, a key immune-checkpoint inhibitor in T cells. Here, we have re-addressed the link between SCFFBXO38 and PD-1 proteolysis. Our data do not support the notion that SCFFBXO38 directly or indirectly controls the abundance and stability of PD-1 in T cells.

Gut microbiome influences efficacy of Endostatin combined with PD-1 blockade against colorectal cancer.

The combination of anti-angiogenic drugs and immune checkpoint inhibitors (ICIs) in the treatment of tumors is emerging as a way to improve ICIs-resistant tumor therapy. In addition, gut microbes (GMs) are involved in angiogenesis in the tumor microenvironment and are also associated with the antitumor function of immune checkpoint inhibitors. However, it is unclear whether gut microbes have a role in anti-tumor function in the combination of anti-angiogenic drugs and immune checkpoint inhibitors for cancer treatment. Endostatin, an angiogenesis inhibitor, has been widely used as an antiangiogenic therapy for cancer. We showed that combined therapy with an adenovirus encoding human endostatin, named Ad-E, and PD-1 blockade dramatically abrogated MC38 tumor growth. The structure of intestinal microbes in mice was changed after combination treatment. We found that the antitumor function of combination therapy was inhibited after the elimination of intestinal microbes. In mice with depleted microbiota, oral gavage of Bacteroides fragilis salvaged the antitumor effects of combination Ad-E and αPD-1 monoclonal antibody (mAb) to a certain extent. Further, Bacteroides fragilis could improve CD3+T cells, NK cells, and IFNγ+CD8+ T cells in the tumor microenvironment to inhibit tumor growth. Besides, Bacteroides fragilis might restore antitumor function by down-regulating isobutyric acid (IBA). Our results suggested that GMs may be involved in the combination of Ad-E and αPD-1 mAb for cancer treatment, which has oncological implications for tumor growth dynamics and cancer immune surveillance.

Programmed death receptor (PD-)1/PD-ligand (L)1 in urological cancers : the "all-around warrior" in immunotherapy.

Programmed death receptor-1 (PD-1) and its ligand, programmed death ligand-1 (PD-L1) are essential molecules that are key in modulating immune responses. PD-L1 is constitutively expressed on various immune cells, epithelial cells, and cancer cells, where it functions as a co-stimulatory molecule capable of impairing T-cell mediated immune responses. Upon binding to PD-1 on activated T-cells, the PD-1/PD-L1 interaction triggers signaling pathways that can induce T-cell apoptosis or anergy, thereby facilitating the immune escape of tumors. In urological cancers, including bladder cancer (BCa), renal cell carcinoma (RCC), and prostate cancer (PCa), the upregulation of PD-L1 has been demonstrated. It is linked to poor prognosis and enhanced tumor immune evasion. Recent studies have highlighted the significant role of the PD-1/PD-L1 axis in the immune escape mechanisms of urological cancers. The interaction between PD-L1 and PD-1 on T-cells further contributes to immunosuppression by inhibiting T-cell activation and proliferation. Clinical applications of PD-1/PD-L1 checkpoint inhibitors have shown promising efficacy in treating advanced urological cancers, significantly improving patient outcomes. However, resistance to these therapies, either intrinsic or acquired, remains a significant challenge. This review aims to provide a comprehensive overview of the role of the PD-1/PD-L1 signaling pathway in urological cancers. We summarize the regulatory mechanism underlying PD-1 and PD-L1 expression and activity, including genetic, epigenetic, post-transcriptional, and post-translational modifications. Additionally, we discuss current clinical research on PD-1/PD-L1 inhibitors, their therapeutic potential, and the challenges associated with resistance. Understanding these mechanisms is crucial for developing new strategies to overcome therapeutic limitations and enhance the efficacy of cancer immunotherapy.

Polymeric PD1/PDL1 bispecific antibody enhances immune checkpoint blockade therapy.

Immune checkpoint blockade (ICB) therapy, particularly PD1/PDL1 inhibition, has demonstrated success in bolstering durable responses in patients. However, the response rate remains below 30 %. In this study, we developed a polymeric bispecific antibody (BsAb) targeting PD1/PDL1 to enhance ICB therapy. Specifically, poly(L-glutamic acid) (PGLU) was conjugated with a double cyclic Fc binding peptide, Fc-III-4C, through condensation reactions between the -COOH group of PGLU and the -NH2 group of Fc-III-4C. This conjugate was then mixed with αPD1 and αPDL1 monoclonal antibodies (mAbs) in an aqueous solution. Mechanistically, the PD1/PDL1 BsAb (BsAbαPD1+αPDL1) acts as a bridge between tumor cells and CD8+ T cells, continuously activating CD8+ T cells to a greater extent. This leads to significantly suppressed tumor growth and prolonged survival in a mouse model of colon cancer compared to treatment with either a single mAb or a mixture of free mAbs. The tumor suppression rate achieved by the BsAbαPD1+αPDL1 was 90.1 %, with a corresponding survival rate of 83.3 % after 48 days. Thus, this study underscores the effectiveness of the BsAbαPD1+αPDL1 as a synchronizing T cell engager and dual ICBs, offering theoretical guidance for clinical ICB therapy.

An overview of immune checkpoint inhibitor toxicities in bladder cancer.

Bladder cancer is the tenth most prevalent malignancy worldwide, with a significant mortality burden. Urothelial carcinoma (UC) is the most common histological subtype, and treatment options are guided by whether the disease is muscle-invasive (MIBC) or non-muscle-invasive (NMIBC), with subsequent risk group stratification. The growing popularity of immune checkpoint inhibitors (ICIs) to treat MIBC and NMIBC as either monotherapy or combined with intravesical agents, may radically change the treatment paradigm of UC. Current treatments for NMBIC includes intravesical chemotherapy after trans-urethral resection of the bladder tumour, intravesical bacillus Calmette-Guerin (BCG) or radical cystectomy. Cisplatin-based chemotherapy is widely regarded as the first-line treatment for metastatic UC due to its beneficial response and survival rates when compared to alternative therapies. However, up to 70 % of metastatic UC patients are ineligible, and the prognosis of these patients remains poor, with a median survival of 13-16 months. For NMIBC and MIBC, ICIs provide a promising alternative for cisplatin-ineligible patients. In UC, ICIs including atezolizumab, nivolumab, avelumab, and pembrolizumab are Food and Drug Administration (FDA)-approved for monotherapy, and have demonstrated promising results, particularly in those who cannot receive cisplatin-based chemotherapy, and as a second-line treatment option for recurrent UC following platinum-based chemotherapy. It is important to consider that some patients may experience adverse events (AEs) with limited clinical benefit. Infusion-related reactions and immune-mediated AEs (imAEs) such as colitis, endocrinopathies, hepatitis, pneumonitis, interstitial lung disease, renal dysfunction, nephritis, cutaneous and neurological toxicities must be monitored for. Currently, there is no clear consensus on the role of a 'two-year stopping rule' in reducing the risk of imAEs, with further research on the optimal treatment duration of ICIs required. With increased ICI use, vigilance regarding their side effects is imperative. This review aims to provide an updated overview of ICI toxicities in bladder cancer, to assist clinicians in their therapeutic decision-making, with consideration of patient characteristics and the clinical context.

Esterase responsive release of anti-cancer agents from conjugated lipid nanocarrier and the regulatory considerations.

The release of active agents in tumors rather than normal tissues, limits systemic exposure and toxicities. Targeting over-expressed esterase enzyme in the tumor microenvironment can selectively release immune-active agents like Programmed Death-1 (PD-1) and PD-1 ligand inhibitors from ester-sensitive lipid nanocarriers, offering a novel approach compared with conventional therapies. PD-1 and PD-L1 association cause T-cell inactivation, whereas blocking their association improves their cytotoxic mechanism. The patent application US2022/0080051-A1 discloses a novel immune-active agent conjugated with lipid to form a nanocarrier for esterase-sensitive release. These nanocarriers selectively enter leaky vasculature of tumors through enhanced permeability and retention effect, undergo ester cleavage to release agents, and are reported to increase bioavailability by 24 times. Further, with other agents or alone it achieves targeted synergistic cancer therapy. Also, the current patent spotlight delves into the crucial formulation considerations necessary for obtaining successful approval of lipidic nano products from relevant regulatory authorities.

[Box: see text].

Evaluation of PD-1 and interleukin-10-receptor expression by T lymphocytes in malignant and benign pleural effusions.

PD-1 (programmed cell death protein-1)/PD-L1 (programmed cell death ligand 1) as well as IL-10 (interleukin-10)/IL-10R (interleukin-10 receptor) interactions play a major role in tumor immune evasion in various malignancies. Several studies investigated the expression of PD-1 on T lymphocytes in pleural effusions (PE) in patients with malignant diseases. However, results in malignant pleural effusions (MPE) compared to benign PE (BPE) are underreported. In this prospective study, 51 patients (median age 66 years, IQR 54-78, 47% male) with PE of malignant or benign origin at the Medical University of Vienna between March 2021 and November 2022 were enrolled and divided into three groups according to the cytological results (group 1: MPE [n = 24, 47%]; group 2: BPE in malignant disease [n = 22, 43%]; group 3: BPE in benign disease [n = 5, 10%]). In the cytological samples, T cells were analyzed for the expression of PD-1 and IL-10R via flow cytometry. In MPE, the proportion of PD-1+ T lymphocytes on CD4+ cells was significantly lower than in BPE (40.1 vs. 56.3 in group 1 vs. 3, p = 0.019). Moreover, a significantly lower expression of PD-1+ IL-10R+ CD8+ (9.6 vs. 35.2 in group 1 vs. 2, p = 0.016; 9.6 vs. 25.0 in group 1 vs. 3, p = 0.032) and a significantly higher expression of PD-1-IL-10R-CD8+ T lymphocytes (43.7 vs. 14.0 in group1 vs. 2, p = 0.045; 43.7 vs. 23.3 in group 1 vs. 3, p = 0.032) were observed in MPE when compared to BPE. The frequency of T cells expressing PD-1 and IL-10R on CD8+ T cells is significantly lower in MPE compared to BPE regardless of the underlying disease indicating a different microenvironment in PE driven by the presence of tumor cells. Our observation spotlights the possible involvement of PD-1 and IL-10R in MPE.

Unraveling Th subsets: insights into their role in immune checkpoint inhibitor therapy.

T helper (Th) cell subsets play pivotal roles in regulating immune responses within the tumor microenvironment, influencing both tumor progression and anti-tumor immunity. Among these subsets, Th1 cells promote cytotoxic responses through the production of IFN-γ, while Th2 cells and regulatory T cells (Tregs) exert immunosuppressive effects that support tumor growth. Th9 and Th17 cells have context-dependent roles, contributing to both pro-inflammatory and regulatory processes in tumor immunity. Tumor antigen-specific T cells within the tumor microenvironment often exhibit a dysfunctional phenotype due to increased expression of inhibitory receptors such as CTLA-4 and PD-1, leading to reduced antitumor activity. Monoclonal antibodies that block these inhibitory signals-collectively known as immune checkpoint inhibitors (ICIs)-can reactivate these T cells, enhancing their ability to target and destroy cancer cells. Recent advancements have highlighted the critical role of T helper subsets in modulating responses to ICIs, with their interactions remaining a focus of ongoing research. Both positive and negative effects of ICIs have been reported in relation to Th cell subsets, with some effects depending on the type of tumor microenvironment. This review summarizes the crucial roles of different T helper cell subsets in tumor immunity and their complex relationship with immune checkpoint inhibitor therapy.

SIN3B Loss Heats up Cold Tumor Microenvironment to Boost Immunotherapy in Pancreatic Cancer.

Despite progress significant advances in immunotherapy for some solid tumors, pancreatic ductal adenocarcinoma (PDAC) remains unresponsive poorly responsive to such interventions, largely due to its highly immunosuppressive tumor microenvironment (TME) with limited CD8+ T cell infiltration. This study explores the role of the epigenetic factor Sin3B in the PDAC TME. Using murine PDAC models, we found that tumor cell-intrinsic Sin3B loss reshapes the TME, increasing CD8+ T cell infiltration and cytotoxicity, thus impeding tumor progression and enhancing sensitivity to anti-PD1 treatment. Sin3B-deficient tumor cells exhibited amplified CXCL9/10 secretion in response to Interferon-gamma (IFNγ), creating a positive feedback loop via the CXCL9/10-CXCR3 axis, thereby intensifying the anti-tumor immune response against PDAC. Mechanistically, extensive epigenetic regulation is uncovered by Sin3B loss, particularly enhanced H3K27Ac distribution on genes related to immune responses in PDAC cells. Consistent with the murine model findings, analysis of human PDAC samples revealed a significant inverse correlation between SIN3B levels and both CD8+ T cell infiltration and CXCL9/10 expression. Notebly, PDAC patients with lower SIN3B expression showed a more favorable response to anti-PD1 therapy. The findings suggest that targeting SIN3B can enhance cytotoxic T cell infiltration into the tumor site and improve immunotherapy efficacy in PDAC, offering potential avenues for therapeutic biomarker or target in this challenging disease.

Chemotherapy combined with lenvatinib and PD-1 may be a potential better alternative option for advanced unresectable intrahepatic cholangiocarcinoma: a retrospective real-world study.

Background: Currently, the prognosis of advanced intrahepatic cholangiocarcinoma (ICC) is poor, and the current treatment methods are not effective. Objective: The aim of this study was to evaluate the anticancer efficacy of chemotherapy combined with PD-1 inhibitors and tyrosine kinase inhibitors (TKIs) in patients with ICC. Methods: We retrospectively screened patients with advanced intrahepatic cholangiocarcinoma (ICC) who received chemotherapy combined with lenvatinib and PD-1. We evaluated overall survival (OS), progression-free survival (PFS), the objective response rate (ORR), the disease control rate (DCR), the tumor shrinkage rate, and safety. Results: We enrolled 95 patients with ICC and divided them into three groups with a median follow-up duration of 15.1 months. The chemotherapy group (chemo-regimen group), chemotherapy combined with immune checkpoint inhibitors (dual-regimen group), and chemotherapy combined with lenvatinib (triple-regimen group) had median OS times of 13.1 months, 20.8 months, and 39.6 months, respectively. Notably, the triple-regimen group had a significantly longer OS than did the chemo-regimen and dual-regimen groups. The chemo-regimen group, dual-regimen group, and triple-regimen group reported median PFS durations of 4.8 months, 11.9 months, and 23.4 months, respectively. Both combination groups exhibited significantly longer PFS than the chemotherapy-only group (P<0.05). The ORRs of the chemo-regimen, dual-regimen, and triple-regimen groups were 18.2%, 55.5%, and 54.7%, respectively. The DCRs were 72.7%, 90%, and 96.2%, respectively, indicating significantly better outcomes in the combination therapy groups. Conclusion: The combination of chemotherapy with PD-1 inhibitors and lenvatinib demonstrates considerable efficacy and tolerability as a treatment strategy for patients with advanced ICC.

Spatial heterogeneity of PD-1/PD-L1 defined osteosarcoma microenvironments at single-cell spatial resolution.

Osteosarcoma, predominantly affecting children and adolescents, is a highly aggressive bone cancer with a 5-year survival rate of 65-70%. The spatial dynamics between TAM and other cellular subtypes, including T cells, osteoblasts and osteoclasts, are critical for understanding the complexities of the osteosarcoma tumor microenvironment (TME) and can provide insights into potential immunotherapeutic strategies. Our study employs a pioneering approach that combines deep learning-based digital image analysis with multiplex fluorescence immunohistochemistry (mfIHC) to accurately implement cell detection, segmentation, and fluorescence intensity measurements for in-depth study of the TME. We introduce a novel algorithm for TAM/osteoclast differentiation, crucial for accurate characterization of cellular composition. Our findings reveal distinct heterogeneity in cell composition and spatial orchestration between PD-1 (-/+) and PD-L1 (-/+) patients, highlighting the role of T-cell functionality in this context. Furthermore, our analysis demonstrates the efficacy of nivolumab in suppressing tumor growth and enhancing lymphocyte infiltration without altering the M1/M2 TAM ratio. This study provides critical insights into the spatial orchestration of cellular subtypes within the PD-1/PD-L1 defined osteosarcoma TME. By leveraging advanced mfIHC and artificial intelligence, we underscore the critical role of TAMs and T-cell interactions, proposing new therapeutic avenues focusing on TAM repolarization and targeted immunotherapies, thus underscoring the study's potential impact on improving osteosarcoma treatment.

Immune checkpoint inhibitor-induced diarrhea and colitis: an overview.

Immune checkpoint inhibitors (ICIs) have emerged as an integral component of the management of various cancers and have contributed to significant improvements in overall survival. Most available ICIs target anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA4), and anti-programmed cell death 1/programmed cell death ligand 1 (anti-PD1/PDL1). Gastrointestinal immune-related adverse events remain a common complication of ICIs. The predominant manifestations include diarrhea and colitis, which often manifest concurrently as immune-mediated diarrhea and colitis (IMDC). Risk factors for developing these side effects include baseline gut microbiota, preexisting autoimmune disorders, such as inflammatory bowel disease, and type of neoplasm. The hallmark symptom of colitis is diarrhea which may be accompanied by mucus or blood in stools. Patients may also experience abdominal pain, fever, vomiting, and nausea. If not treated rapidly, ICI-induced colitis can lead to serious life-threatening complications. Current management is based on corticosteroids as first-line, and immunosuppressants like infliximab or vedolizumab for refractory cases. Microbiota transplantation and specific cytokines and lymphocyte replication inhibitors are being investigated. Optimal patient care requires maintaining a balance between treatment toxicity and efficacy, hence the aim of this review is to enhance readers' comprehension of the gastrointestinal adverse events associated with ICIs, particularly IMDC. In addition to identifying the risk factors, we discuss the incidence, clinical presentation, workup, and management options of IMDC.

Outcomes of adjuvant immune checkpoint inhibitor therapy in melanoma: a retrospective study.

BACKGROUND: Adjuvant treatment of malignant melanoma has improved the outcomes for patients. However, real-world data on efficacy and safety are limited. We investigated outcomes of melanoma patients treated with adjuvant immune checkpoint inhibitors (ICI) in the Ghent University Hospital. METHODS: Patients with melanoma (stage III-IV), who received at least one cycle of ICI as adjuvant treatment between 2018 and 2021 were included in this retrospective cohort study. Primary outcomes were recurrence-free (RFS) and overall survival (OS). Other outcomes of interest were relapse patterns and safety. RESULTS: 59 patients were included, with a median follow-up of 36 months. Disease recurrence or death of any cause was observed in 25/59 (42.4%) of the patients. The median RFS was 56.0 months (95%CI 36.1-75.9 months). At 48 months, RFS and OS were 55.9% and 84%, respectively. 9/23 (39%) recurrences were locoregional and 14/23 (60.9%) patients developed distant metastasis as first recurrence, including 2 (3.4%) with brain metastasis. Median time to recurrence was 9 months (range 2-56 months). 35/59 (59.3%) completed one year of adjuvant treatment, 12/59 (20.3%) stopped because of recurrence and 10/59 (16.9% because of toxicity. Immune-related adverse events wereseen in 29/59 (49.4%) patients, 10/59 (16.9%) developed grade 3-4 toxicity. CONCLUSION: This study confirms the real-world efficacy and safety of adjuvant ICI for melanoma, achieving RFS and OS comparableto the pivotal clinical trials. About 40% of patients develop arelapse, mainly during the adjuvant treatment. The outcomes ofpatients progressing during adjuvant ICI are poor, emphasizing the need of prospective and real-world studies on optimal management after progression on (neo)adjuvant treatment.

Eravacycline improves the efficacy of anti-PD1 immunotherapy via AP1/CCL5 mediated M1 macrophage polarization in melanoma.

Screening approved library is a promising and safe strategy to overcome the limitation of low response rate and drug resistance in immunotherapy. Accumulating evidence showed that the application of antibiotics has been considered to reduce the effectiveness of anti-PD1 immunotherapy in tumor treatment, however, in this study, an antibiotic drug (Eravacycline, ERV) was identified to improve the efficacy of anti-PD1 immunotherapy in melanoma through screening approved library. Administration of ERV significantly attenuated melanoma cells growth as well as directly or indirectly benefited M1 macrophage polarization. Meanwhile, ERV treatment significantly induced cellular autophagy via damage of mitochondria, leading to up-regulation of ROS production, subsequently, raised CCL5 secretion through elevation AP1 binding to CCL5 promoter via p38 or JNK1/2 activation. Knockdown of Ccl5 expression attenuated ERV triggered M1 macrophage polarization in melanoma cells. Clinical analysis revealed a positive association between high expression of CCL5 and improved prognosis as well as a favorable anti-PD1 therapy in melanoma patients. As expected, application of ERV improved the efficacy of anti-PD1. Overall, our results approved that ERV enhances the efficacy of anti-PD1 immunotherapy in melanoma by promoting the polarization of M1 macrophages, which provided novel therapeutic strategy for improving the effectiveness of melanoma anti-PD1 immunotherapy.

Seven-year analysis of adjuvant pembrolizumab versus placebo in stage III melanoma in the EORTC1325 / KEYNOTE-054 trial.

In the previously reported primary analyses of this phase 3 trial, 12 months of adjuvant pembrolizumab resulted in significantly longer recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) than placebo in patients with resected high risk stage III melanoma. Stability of these benefits when the median follow-up was 3.5 and 5 years was published. Here we report results with a longer follow-up. METHODS: We randomized 1019 patients to receive pembrolizumab 200 mg or placebo, intravenously every 3 weeks for a total of 18 doses. RFS in the overall population and in the subgroup of patients with melanoma positive for the PD-1 ligand (PD-L1) were co-primary endpoints. DMFS in these two populations was a secondary and progression/recurrence-free survival 2 (PRFS2) an exploratory endpoint. RESULTS: The median follow-up was 6.9 years. In the overall intention-to-treat population, RFS was longer in the pembrolizumab group than in the placebo group (HR 0.63, 95 % CI 0.53 to 0.74). RFS at 7 years was 50 % (95 % CI 46 % to 55 %) in the pembrolizumab and 36 % (95 % CI 32 % to 41 %) in the placebo group. Positive effects were present both for loco-regional recurrences and distant metastases, and across substages IIIA-IIIB-IIIC, and PD-L1 positive and PD-L1 negative as well as for BRAF mutant and BRAF wild type populations. DMFS was longer in the pembrolizumab group than in the placebo group (HR 0.64, 95 % CI 0.54 to 0.76). DMFS at 7 years was 54 % (95 % CI 50 % to 59 %) in the pembrolizumab and 42 % (95 % CI 37 % to 46 %) in the placebo group. PRFS2 was longer in the pembrolizumab group than in the placebo group (HR 0.69, 95 % CI 0.57 to 0.84). PRFS2 at 7 years was 61 % (95 % CI 57 % to 66 %) in the pembrolizumab and 53 % (95 % CI 49 % to 57 %) in the placebo group. CONCLUSIONS: The 7-year analysis of adjuvant therapy with pembrolizumab demonstrated a sustained improvement in the long-term RFS, DMFS and PRFS2 compared with placebo in patients with resected stage III melanoma.

Exosomal miR-142-3p from M1-polarized macrophages suppresses cell growth and immune escape in glioblastoma through regulating HMGB1-mediated PD-1/PD-L1 checkpoint.

Glioblastoma (GBM) is one of the most prevalent cancerous brain tumors. Former studies have reported that exosomes derived from M1-polarized macrophages (M1 exosomes) inhibit tumor occurrence and development through delivery of tumor suppressor genes. Also, microRNA-142-3p (miR-142-3p) has been verified to function as a tumor suppressor. GBM cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8), colony formation assay and 5-ethynyl-2'-deoxyuridine (EdU) assay; cell apoptosis was determined by flow cytometry analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Mechanism investigations were conducted for analyzing the molecular mechanism by which miR-142-3p and M1 exosomes affect GBM progression. Upregulation of miR-142-3p expression was detected in M1-polarized macrophages and M1 exosomes. M1 exosomes inhibit GBM cell proliferation and trigger cell apoptosis. Functionally, miR-142-3p silencing promotes the proliferation and inhibits the apoptosis of GBM cells treated with M1 exosomes. As for molecular mechanism, miR-142-3p inhibits GBM cell growth via targeting high-mobility group box 1 (HMGB1). In addition, miR-142-3p/HMGB1 axis affects GBM cell immune escape through modulation of programmed death-1/programmed death ligand-1 (PD-1/PD-L1) checkpoint. Our study demonstrated that exosomal miR-142-3p from M1-polarized macrophages suppresses cell growth and immune escape in GBM through regulating HMGB1-mediated PD-1/PD-L1 checkpoint.

Successful treatment of trichilemmal carcinoma with distant metastasis using pembrolizumab: a case report and review.

Trichilemmal carcinoma (TC) is a rare, malignant cutaneous adnexal tumor. TC often has nonspecific clinical manifestations and its aggressive nature is frequently overlooked. Metastasis of TC is rarely reported and there is no standard treatment for recurrent or metastatic TC. We report a complicated case of TC arising from the parotid gland with metastasis to cervical lymph nodes. The tumor progressed after multiple surgeries, radiation and chemotherapy. Finally, the patient achieved good response and disease control with pembrolizumab, an immune checkpoint inhibitor targeting programmed cell death protein-1. Currently, the patient has received 19 cycles of pembrolizumab and the disease remains well controlled. This represents the first reported use of immune checkpoint blockade to treat TC.

This paper discusses a rare form of skin cancer called trichilemmal carcinoma (TC) and presents a distant metastasis TC case. The patient was treated with an immunotherapy called pembrolizumab and after 19 courses of treatment, the tumor was significantly reduced and the symptoms were relieved. This case report is the first recorded case study of pembrolizumab for the treatment of TC and provides a new approach to the treatment of challenging malignancies.

Predictive value of near-term prediction models for severe immune-related adverse events in malignant tumor PD-1 inhibitor therapy.

Immune-related adverse events (irAEs) impact outcomes, with most research focusing on early prediction (baseline data), rather than near-term prediction (one cycle before the occurrence of irAEs and the current cycle). We aimed to explore the near-term predictive value of neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), absolute eosinophil count (AEC) for severe irAEs induced by PD-1 inhibitors. Data were collected from tumor patients treated with PD-1 inhibitors. NLR, PLR, and AEC data were obtained from both the previous and the current cycles of irAEs occurrence. A predictive model was developed using elastic net logistic regression Cutoff values were determined using Youden's Index. The predicted results were compared with actual data using Bayesian survival analysis. A total of 138 patients were included, of whom 47 experienced grade 1-2 irAEs and 18 experienced grade 3-5 irAEs. The predictive model identified optimal α and λ through 10-fold cross-validation. The Shapiro-Wilk test, Kruskal-Wallis test and logistic regression showed that only current cycle data were meaningful. The NLR was statistically significant in predicting irAEs in the previous cycle. Both NLR and AEC were significant predictors of irAEs in the current cycle. The model achieved an area under the ROC curve (AUC) of 0.783, with a sensitivity of 77.8% and a specificity of 80.8%. A probability ≥ 0.1345 predicted severe irAEs. The model comprising NLR, AEC, and sex may predict the irAEs classification in the current cycle, offering a near-term predictive advantage over baseline models and potentially extending the duration of immunotherapy for patients.

A Case of Bullous Pemphigoid with Significant Infiltration of CD4-Positive T Cells during Treatment with Pembrolizumab, Accompanied by Pembrolizumab-Induced Multi-Organ Dysfunction.

Immune checkpoint inhibitors (ICIs) activate T cells, causing immune-related adverse events (irAEs). Skin manifestations are common among irAEs, but ICI-associated bullous pemphigoid (BP) is rare. Inhibiting programmed death (PD)-1 signaling, in addition to causing epitope spreading, may disrupt B and T cell balance, causing excessive autoantibody production against the skin's basement membrane, leading to BP. A 70-year-old woman developed late-onset multi-organ irAEs, including diarrhea, thyroid dysfunction, and BP, while receiving pembrolizumab, a PD-1 inhibitor. This highlights the long-term risk of irAEs, which can occur 2-3 years after starting ICIs. In cases of multi-organ irAE, C-reactive protein levels and neutrophil/lymphocyte ratio are often low. These characteristics were observed in our case. Few papers address multiple organ involvement, highlighting the need to consider irAEs in a multi-organ context. While it is known that drug-induced skin reactions worsen as blood eosinophil counts increase, in our case, the eosinophil count remained normal, suggesting that ICI-associated BP might have been controlled without discontinuing the ICI and through tapering of low-dose oral prednisone treatment. Additionally, in this case, significant CD4-positive T cell infiltration was observed in the immunostaining examination of the blisters, indicating that severe CD4-positive T cell infiltration induced by the ICI might have led to multi-organ involvement, including severe diarrhea. Few reports focus on blood eosinophil counts in BP cases or discuss CD4 and CD8 immunostaining in BP cases. Therefore, future research should explore the relationship between blood eosinophil counts, immunostaining results, and the prognosis of irAEs, including BP, in treatment courses.

Therapeutical Usefulness of PD-1/PD-L1 Inhibitors in Aggressive or Metastatic Pituitary Tumours.

Therapeutic options for pituitary neuroendocrine tumours (PitNETs) refractory to temozolomide are scarce. Immune checkpoint inhibitors (ICIs), particularly inhibitors of the programmed cell death-1 (PD-1) pathway and its ligand (PD-L1), have been experimentally used in aggressive or metastatic PitNETs. We aimed to study the therapeutic usefulness of anti-PD-1 drugs in patients with aggressive or metastatic PitNETs. Published cases and case series involving patients with PitNETs treated with PD-1/PD-L1 inhibitors were reviewed. Demographic data, clinical-pathological features, previous therapies, drug dosage and posology, and the best radiological and biochemical responses, as well as survival data, were evaluated. We identified 29 cases of aggressive (n = 13) or metastatic (n = 16) PitNETs treated with PD-1/PD-L1 inhibitors. The hypersecretion of adrenocorticotropic hormone (ACTH) was documented in eighteen cases (62.1%), seven were prolactinomas (24.1%), and four were non-functioning PitNETs. All patients underwent various therapies prior to using ICIs. Overall, a positive radiological response (i.e., partial/complete radiological response and stable disease) was observed in eighteen of twenty-nine cases (62.1%), of which ten and four were ACTH- and prolactin-secreting PitNETs, respectively. Hormonal levels reduced or stabilised after using ICIs in 11 of the 17 functioning PitNET cases with available data (64.7%). The median survival of patients treated with ICIs was 13 months, with a maximum of 42 months in two ACTH-secreting tumours. Among 29 patients with PitNETs treated with PD-1/PD-L1 inhibitors, the positive radiological and biochemical response rates were 62.1% and 64.7%, respectively. Altogether, these data suggest a promising role of ICIs in patients with aggressive or metastatic PitNETs refractory to other treatment modalities.