PD-L1 Expression Research Articles

Preclinical evaluation and preliminary clinical study of 68Ga-NODAGA-NM-01 for PET imaging of PD-L1 expression

BackgroundProgrammed cell death 1/programmed death ligand-1 (PD-L1)-based immune checkpoint blockade is an effective treatment approach for non-small-cell lung cancer (NSCLC). However, immunohistochemistry does not accurately or dynamically reflect PD-L1 expression owing to its spatiotemporal heterogeneity. Herein, we assessed the feasibility of using a 68Ga-labeled anti-PD-L1 nanobody, 68Ga-NODAGA-NM-01, for PET imaging of PD-L1.MethodsMicro-PET/CT and biodistribution studies were performed on PD-L1-positive and -negative tumor-bearing mice. Additionally, a preliminary clinical study was performed on two patients with NSCLC. NM-01 was radiolabeled with 68Ga without further purification under mild conditions.Results68Ga-NODAGA-NM-01 exhibited radiochemical purity (> 98%), high stability in vitro, and rapid blood clearance in vivo. Specific accumulation of 68Ga-NODAGA-NM-01 was observed in PD-L1-positive tumor-bearing mice, with a good tumor-to-background ratio 0.5h post-injection. Furthermore, 68Ga-NODAGA-NM-01 PET/CT imaging was found to be safe with no adverse events and distinct uptake in primary and metastatic lesions of the PD-L1-positive patient, with a higher maximal standardized uptake value than that in lesions of the PD-L1-negative patient 1h post-injection.Conclusions68Ga-NODAGA-NM-01 can be prepared using a simple method under mild conditions and reflect PD-L1 expression in primary and metastatic lesions. However, our findings need to be confirmed in a large cohort.Trial registrationNCT02978196. Registered February 15, 2018.

Botensilimab (Fc-enhanced anti-cytotoxic lymphocyte-association protein-4 antibody) Plus Balstilimab (anti-PD-1 antibody) in Patients With Relapsed/Refractory Metastatic Sarcomas.

Outcomes for patients with advanced sarcomas are poor and there is a high unmet need to develop novel therapies. The purpose of this phase I study was to define the safety and efficacy of botensilimab (BOT), an Fc-enhanced anti-cytotoxic lymphocyte-association protein-4 antibody, plus balstilimab (BAL), an anti-PD-1 antibody, in advanced sarcomas. BOT was administered intravenously (IV) at 1 mg/kg or 2 mg/kg once every 6 weeks in combination with BAL IV at 3 mg/kg once every 2 weeks for up to 2 years. The primary end point was to determine dose-limiting toxicities during the dose-escalation period. Secondary end points include objective response rate (ORR), duration of response (DOR), disease control rate, and progression-free survival (PFS) by RECIST 1.1. Exploratory end points include assessing patient biomarkers including tumor mutational burden, cytokines, and PD-L1 expression. Overall, 64 patients with sarcoma were treated; all were evaluable for safety and 52 for efficacy. The most common treatment-related adverse event (TRAE) was diarrhea/colitis occurring in 35.9% of patients, with grade 3 in 6.3% of patients. No grade 4 or 5 TRAEs were reported. For all evaluable patients, ORR was 19.2% (95% CI, 9.6 to 32.5), and 27.8% (95% CI, 9.7 to 53.5) for evaluable patients with angiosarcoma (n = 18); 33.3% in visceral and 22.2% in cutaneous subtypes. Median PFS for evaluable patients was 4.4 months (95% CI, 2.8 to 6.1), with a 6-month PFS rate of 36% (95% CI, 22 to 50) and a median DOR of 21.7 months (95% CI, 1.9 to not reached). The combination of BOT/BAL demonstrated promising efficacy and safety in a large cohort of heavily pretreated sarcoma patients. This encouraging activity warrants further investigation (ClinicalTrials.gov identifier: NCT03860272).

Verticillin A-Loaded Surgical Buttresses Prevent Local Pancreatic Cancer Recurrence in a Murine Model.

The fungal metabolite verticillin A is a potent and selective histone methyltransferase inhibitor. It regulates apoptosis, the cell cycle, and stress response, and displays potent activity in the suppression of tumor cell growth in several different in vivo models. Verticillin A sensitizes pancreatic cancer cells to anti-PD-1 immunotherapy by regulating PD-L1 expression. However, as with many natural products, delivery and systemic toxicity are challenges that must be overcome to advance their use as a chemotherapeutic. To both reduce systemic toxicity and improve delivery, we report a verticillin A-loaded surgical buttress, which is well-tolerated at a dose as high as 40 mg/kg. In contrast, free verticillin A administered systemically results in toxicity at a dose of 3 mg/kg. The verticillin A-loaded buttress suppresses tumor recurrence in vivo in a safe and dose-dependent manner against a highly aggressive and metastatic model of pancreatic cancer.

A panel of cancer testis antigens in squamous cell carcinoma of the lung, head and neck, and esophagus: implication for biomarkers and therapeutic targets

This study aims to investigate the expression of seven cancer testis antigens (MAGE-A1, MAGE-A4, MAGE-A10, MAGE-A11, PRAME, NY-ESO-1 and KK-LC-1) in pan squamous cell carcinoma and their prognostic value, thus assessing the potential of these CTAs as immunotherapeutic targets. The protein expression of these CTAs was evaluated by immunohistochemistry in 60 lung squamous cell carcinoma (LUSC), 62 esophageal squamous cell carcinoma (ESCA) and 62 head and neck squamous cell carcinoma (HNSC). The relationship between CTAs expression and progression-free survival (PFS) was assessed. PD-L1 expression and tumor-infiltrating lymphocytes were also collected and correlated with CTAs expression. The prognostic impact of CTAs gene expression was evaluated using the Kaplan–Meier Plotter website. CTAs expression was 0–48% in ESCA, 3%-77% in LUSC, and 3%-71% in HNSC. Analysis of PFS showed that MAGE-A1 expression in HNSC (**p < 0.01), PRAME in LUSC (p = 0.008, **p < 0.01), MAGE-A10 (p = 0.012, *p < 0.05) and PRAME (p = 0.021, *p < 0.05) in ESCA were significantly correlated with PFS. In all three cancers, coexpression of three CTAs was used as a cutoff value for grouping, and the results showed a significant difference in PFS between these two groups. Moreover, CTAs expression was significantly correlated with PD-L1 expression and T cell infiltration. These findings indicate a high incidence of CTA expression in HNSC, LUSC and ESCA, which was correlated with PD-L1 expression, T cell infiltration, and tumor progression. The results suggest that cancer testis antigens could be feasible vaccine targets in squamous cell carcinoma.

Abstract P001: Discovery and validation of mTOR as an immune mediator of the FLASH effect

Abstract An area of particular interest in FLASH is the potential influence of the immune microenvironment in the sparing of normal tissue. After finding loss of the FLASH effect via survival studies in immunocompromised SCID mice, we examined proteomic analyses performed upon the skin of BALB/c mice for classifiers of FLASH that may be involved in the immune response. Intriguingly, one of our top hits was a known immune regulator, mTOR (mammalian target of rapamycin). Here we have validated and further explored the role of mTOR in FLASH. For these studies we exposed the pelvic region of 6-7-week-old female BALB/c mice to proton radiation at two different dose rates: FLASH (∼80Gy/s) and conventional (∼0.5Gy/s), with doses of either 0, 12, or 14 Gy, and mice were irradiated in the entrance region of a 50 MeV proton beam. After 27 days, surviving animals were euthanized, and their pelts and colons were collected for analysis. Protein extracts from skin were prepared for Data Independent Acquisition-Mass Spectrometry (DIA-MS) with protein aggregation capture. Peptide and protein levels were quantified using the Skyline software platform, with normalization performed using the limma batch correction. Through recursive feature elimination using a support vector machine, we identified tryptic peptides whose abundance distinguished between FLASH and conventional radiation treatments. Our analysis revealed significant upregulation of mTOR and Raptor (the regulatory associated protein of mTOR) in response to FLASH radiation, suggesting a pivotal role for mTOR signaling in mediating the differential effects of FLASH versus conventional radiation. mTOR is known to promote PD-L1 expression on cancer cells and enhance the infiltration of immune-suppressive lymphocytes into tumors through increased signaling of interferon and TGF-β. Based on these results, we sought to explore whether combining FLASH radiation with immune checkpoint inhibitors could enhance therapeutic efficacy in melanoma treatment. We conducted experiments treating melanoma cell lines and mice with the combination of conventional or FLASH radiation, with and without anti-PD-1, and noted an increase in overall survival of mice treated with FLASH + anti-PD-1 suggesting a potential therapeutic benefit from this combination. In addition, lysates from in vitro and in vivo studies displayed increased levels of phospho-mTOR (Ser2448), as well as downstream phosphorylated substrates signifying the role of mTOR in mediation of this response. Furthermore, immunofluorescent analyses of the normal colons harvested from the MS cohort demonstrate increased mTOR signaling in FLASH via elevated downstream phospho-S6 ribosomal protein. mTOR is a known regulator of the immune response in cancer therapies; interestingly, it may also be a regulator of FLASH radiation in normal tissue. We have validated our MS hit by western blot and IF, but further studies are aimed at the elucidation of this mechanism. Citation Format: Danielle P. Johnson Erickson, Gennie L. Parkman, Alec Morimoto, Benjamin A. Shaver, Zacharias Seitz, Ava Delonais-Dick, Sunan Cui, Ning Cao, Jing Zeng, Justin Sanders, William S. Noble, Christine C. Wu, Ramesh Rengan, Michael J. MacCoss. Discovery and validation of mTOR as an immune mediator of the FLASH effect. [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Targeted Therapies in Combination with Radiotherapy; 2025 Jan 26-29; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(2_Suppl):Abstract nr P001

Clinical difference between solitary and multiple pulmonary adenocarcinoma nodules.

we compared and analyzed the imaging features, tumor markers, pathological immunohistochemistry, and lymph node metastasis rates of solitary and multiple lung adenocarcinoma to provide a valuable reference for clinical diagnosis and treatment. A retrospective analysis of 212 patients who underwent thoracic surgery in our hospital from 2022 to 2023, including 149 patients with a solitary lung adenocarcinoma nodule and 63 patients with multiple primary nodules. Via propensity score matching, the imaging features, tumor serological markers, pathological immunohistochemistry, and lymph node metastasis rates of the two groups were compared, and the differences in lymph node metastasis rates between solitary and multiple nodules were explored by binary logistic regression. After propensity score matching, there were significant differences in the mean CT value (P = 0.001), Ki-67 expression (P < 0.001), PD-L1 expression (P = 0.002), and the lymph node metastasis rate (P = 0.030) between the two groups, but there were no significant differences in nodule type, imaging features, tumor serological marker levels, and the ALK-positive and SYN-positive rates. With lymph node metastasis as the dependent variable, solitary or multiple nodules as the categorical covariate, and the three variables were included as independent variables for binary logistic regression analysis. The probability of lymph node metastasis was 80.8% lower in patients with multiple primary lung adenocarcinoma nodules than in those with a solitary one (P = 0.042). Multiple primary adenocarcinoma nodules exhibit milder biological behavior than solitary adenocarcinoma nodules and carry a lower risk of lymph node metastasis.

Timing Anti-PD-L1 Checkpoint Blockade Immunotherapy to Enhance Tumor Irradiation

Background: The ability of radiotherapy (RT) to drive anti-tumor immunity is limited by adaptive resistance. While RT induces inflammation and recruits activated tumor-infiltrating lymphocytes (TILs), including cytotoxic T lymphocytes (CTLs), the resulting radiation- and IFNγ-dependent PD-L1 expression restores an immunosuppressed tumor microenvironment. Unleashing an effective anti-tumor response may require the precise sequencing of RT and checkpoint blockade immunotherapy (CBI) to block PD-L1 signaling before it can mediate its suppressive effects. Methods: Flank tumors formed in BALB/c mice with syngeneic CT26 colon or 4T1 mammary carcinoma cells were treated with otherwise ineffective doses of ionizing radiation (10 Gy) followed by CBI (0.2 mg anti-PD-L1, i.v.) after 0, 1, 3, 5, or 7 days, comparing tumor response. Anti-PD-L1 delivery was measured by fluorescence, TILs by flow cytometry and immunofluorescence, PD-L1 expression by immunohistochemistry, and tumor size by calipers. Results: In both CT26 and 4T1 tumors, 10 Gy alone resulted in a transient growth delay associated with infiltrating CTLs peaking at 3 days and PD-L1 at 5 days. CTLs returned to baseline after 7 days, consistent with adaptive resistance. Anti-PD-L1 failed to potentiate radiation except when injected 5 days after 10 Gy, which prevented CTL depletion and led to tumor elimination. Potentially contributing to compound effects, anti-PD-L1 penetrated tumors and bound PD-L1 more efficiently after irradiation. Conclusions: Optimal timing to exploit radiation-induced permeability to enhance CBI delivery and interrupt adaptive resistance by blocking PD-L1 as it peaks may offer a general strategy to enhance external beam radiotherapy by protecting activated TILs and potentiating anti-tumor immune response.

Different PD-L1 Assays Reveal Distinct Immunobiology and Clinical Outcomes in Urothelial Cancer.

Testing for PD-L1 expression by immunohistochemistry (IHC) is used to predict immune checkpoint blockade (ICB) benefit but has performed inconsistently in urothelial cancer (UC) clinical trials. Different approaches are used for PD-L1 IHC. We analyzed paired PD-L1 IHC data on UC samples using the SP142 and 22C3 assays from the phase 3 IMvigor130 trial and found discordant findings summarized by four phenotypes: PD-L1 positive by both assays (PD-L1 double positive; PD-L1DP), PD-L1 positive by the SP142 assay only (SP142 single positive; SP142SP), PD-L1 positive by the 22C3 assay only (22C3 single positive; 22C3SP), and PD-L1 negative by both assays double negative (PD-L1 double negative; PD-L1DN). PD-L1DP and SP142SP UCs were associated with more favorable ICB outcomes and increased dendritic-cell (DC) infiltration. SP142 PD-L1 staining co-localized with DC-LAMP, a DC marker, while 22C3 staining was more diffuse. 22C3SP UCs, associated with worse outcomes, were enriched in tumor cell-dominant PD-L1 expression. Multiplex IHC in an independent ICB-treated cohort confirmed that tumor cell-dominant PD-L1 expression was associated with shorter survival. Using different PD-L1 assays, we uncovered that SP142 may preferentially stain PD-L1-expressing DCs, key to orchestrating antitumor immunity, while tumor cell-dominant PD-L1 expression, which underlies a subset of "PD-L1 positive" specimens, is associated with poor ICB outcomes.

Accumulation of CD38 in Hybrid Epithelial/Mesenchymal Cells Promotes Immune Remodeling and Metastasis in Breast Cancer.

Triple-negative breast cancer (TNBC) is a highly metastatic subtype of breast cancer. The epithelial-to-mesenchymal transition is a nonbinary process in the metastatic cascade that generates tumor cells with both epithelial and mesenchymal traits known as hybrid EM cells. Recent studies have elucidated the enhanced metastatic potential of cancers featuring the hybrid EM phenotype, highlighting the need to uncover molecular drivers and targetable vulnerabilities of the hybrid EM state. Here, we discovered that hybrid EM breast tumors are enriched in CD38, an immunosuppressive molecule associated with worse clinical outcomes in liquid malignancies. Altering CD38 expression in tumor cell impacted migratory, invasive, and metastatic capabilities of hybrid EM cells. Abrogation of CD38 expression stimulated an antitumor immune response, thereby preventing the generation of an immunosuppressive microenvironment in hybrid EM tumors. CD38 levels positively correlated with PD-L1 expression in samples from patients with TNBC. Moreover, targeting CD38 potentiated the activity of anti-PD-L1, eliciting strong antitumor immunity, with reduced tumor growth in hybrid EM models. Overall, this research exposes upregulation of CD38 as a specific survival strategy utilized by hybrid EM breast tumors to suppress immune cell activity and sustain metastasis, with strong implications in other carcinomas that have hybrid EM properties. Significance: Hybrid cells co-featuring epithelial and mesenchymal traits in triple-negative breast cancer express elevated levels of CD38 to induce immunosuppression and metastasis, indicating CD38 inhibition as potential strategy for treating breast cancer.

HMGB1 assists the predictive value of tumor PD-L1 expression for the efficacy of anti-PD-1/PD-L1 antibody in NSCLC

BackgroundThe expression of anti-programmed cell death ligand-1 (PD-L1) in tumors is widely used as a biomarker to predict the therapeutic efficacy of anti-programmed cell death-1(PD-1)/PD-L1 antibodies. However, the predictive accuracy of this method is limited. High-mobility group box 1 (HMGB1) is known to modulate cancer immunity. Therefore, we investigated the potential of circulatory HMGB1 in combination with PD-L1 expression to predict the efficacy of anti-PD-1/PD-L1 antibody monotherapy.Patients and methodsThis multicenter retrospective study analyzed blood samples collected from 114 patients with non-small cell lung cancer (NSCLC) prior to anti-PD-1/PD-L1 antibody monotherapy at two university hospitals (Hiroshima University Hospital and Kawasaki Medical School Hospital) between December 2015 and October 2020. We evaluated the association of serum HMGB1 levels with tumor response and progression-free survival (PFS).ResultsSerum HMGB1 levels were significantly higher in patients with complete or partial response than in those with stable or progressive disease. Using receiver operating characteristic analysis, the cut-off level of serum HMGB1 to predict tumor response was determined to be 3.83 ng/mL. PFS was significantly longer in the HMGB1high group than that in the HMGB1low group in the entire cohort (4.3 months vs. 2.3 months) and in patients with NSCLC with PD-L1 tumor proportion score (TPS) ≥ 50% (12.4 months vs. 4.4 months), but not in those with PD-L1 TPS < 50% or unknown.ConclusionHMGB1 may serve as a predictive biomarker for the efficacy of anti-PD-1/PD-L1 antibody therapy in the patients with NSCLC, especially in those with PD-L1 TPS ≥ 50%.

Analysis of Pleiotropic Effects of Nivolumab in Patients with Relapsed Pleural Mesothelioma: A Single-Center Retrospective Study.

In August 2018, the Japanese PMDA approved nivolumab, an immune checkpoint inhibitor, for previously treated, unresectable, advanced, or recurrent pleural mesothelioma (PM) based on the MERIT trial, a phase II study of 34 cases. However, concerns regarding limited evidence persist. We retrospectively analyzed 83 patients with previously treated, unresectable, advanced, or recurrent malignant PM treated with nivolumab from August 2018 to May 2022. Efficacy was evaluated using overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) per modified RECIST criteria. Safety was assessed by treatment-related adverse events (TRAEs) according to CTCAE v5.0. PD-L1 expression was analyzed with the anti-PD-1 antibody (22C3). The median age was 73 years. Histological subtypes included epithelioid (60), sarcomatoid (15), biphasic (6), and unknown (2). Lines of treatment were 2nd (62), 3rd (13), and 4th or later (8). Partial response was seen in 16 patients, stable disease in 30, progressive disease in 29, and not evaluable in 8, with an ORR of 19.3% and a disease control rate of 55.4%. Median PFS and OS were 5.1 and 12.4 months, respectively. TRAEs occurred in 45 patients (54.2%), with grade ≥3 in 6 (7.2%) and one treatment-related death. PFS correlated with male gender, TRAEs, and good performance status (PS: 0-1), while OS correlated with PS. Nivolumab demonstrated efficacy and safety in clinical practice, supporting its use in patients with good PS, even in later lines.

Decreased PD-L1 contributes to preeclampsia by suppressing GM-CSF via the JAK2/STAT5 signal pathway

Programmed cell death protein 1 (PD-1) and its ligand PD-L1 have been detected at the materno-embryonic interface in both human and murine pregnancy models. However, research regarding the PD-1/PD-L1 signal in preeclampsia (PE) is limited. In the present investigation, 30 normal pregnant females and 30 PE patients were enrolled. Cellular functional experiments were performed in two trophoblast cell lines by transfection with lentiviral vectors for overexpression and down-regulation of PD-L1. The placental expressions of PD-1, PD-L1, and granulocyte macrophage colony-stimulating factor (GM-CSF) exhibited a notable reduction in PE cases compared with healthy pregnancies. Cellular functional experiments indicated that excessive PD-L1 expression significantly enhanced trophoblast migratory, invasive, and proliferative capabilities while inhibiting cell apoptosis. Additionally, the administration of lentivirus-mediated PD-L1 overexpression could alleviate clinical symptoms (hypertension, proteinuria) of PE-like rats. Therefore, decreased PD-L1 may contribute to PE by inhibiting GM-CSF via activating the JAK2/STAT5 pathway. Our study provides a novel pathway that can be targeted for the therapy of this disease.

Prognostic and clinical heterogeneity of PD1 and PD-L1- immunohistochemical scores in endometrial cancers.

PD1/PD-L1 inhibition (ICi) has recently become a new standard of care for patients with advanced MMR-deficient (MMRd) endometrial cancers. Nevertheless, response to immunotherapy is more complex than the presence of a single biomarker and therefore it remains challenging to predict patients response to ICi beyond MMRd tumors. Elevated PD-L1 expression (CPS ≥ 1) is often used as a prognostic marker as well as a predictive biomarker of response to ICi in different tumor types. In a retrospective, patient derived study, we analyzed PD1- and PD-L1 staining and correlated the results of different scores to clinical data to evaluate the prognostic impact of these scores. Immunohistochemical analysis of the receptor PD1 and the receptor ligand PD-L1 were performed on TMAs of primary paraffin‑embedded tumor samples. All patients were treated for primary endometrial cancer in the Department of Gynecology and Obstetrics, University Medical Center Schleswig-Holstein, Campus-Lübeck, Germany between the years 2006-2018. The evaluation and determination of the tumor proportion scoring (TPS), the combined positive score (CPS) and the immune cell scoring (IC) was automatically assessed semi-quantitatively, and results were correlated with clinicopathological characteristics and survival. 130 samples were evaluable and 64% showed a positivity (IC > 0) for the receptor PD1 and 56% for the receptor ligand PD-L1. Patients with a PD1 IC Score ≥ 1 showed a significant longer disease-free survival of 140months (95% confidence interval (CI): 124-158) compared to patients with a lower IC < 1 for PD1 of 89months (95% confidence interval (CI): 69-110); p = 0.017). Furthermore, the disease-free survival for patients with a CPS ≥ 5 for PD1 was longer (153.7months (95% confidence interval (CI): 134-173.6) vs. 98.6months (95% confidence interval (CI): 83-114); p = 0.036). Additionally, a PD1 CPS ≥ 5 showed a better overall survival but the result was not statistically significant. No difference in survival was found between patients with PD-L1 higher or lower than CPS 5. In this study we pointed out that there are significant clinical differences among several immunohistochemical scoring systems. In our trial, a PD1-positivity with CPS ≥ 5 and IC ≥ 1 were significantly associated to a better disease-free survival while there was no association with TPS. The PD1-IC scoring was associated with MMRd while the TPS scoring was not. Therefore, PD1-IC could be more appropriate for endometrial carcinomas compared to TPS and could also add prognostic information beside the more established PD-L1-staining. Further prospective studies are needed for a validation of these scores in combination with other biomarkers.

Pathological complete response after neoadjuvant immunochemotherapy in gastric cancer with microsatellite instability without PD-L1 expression (CPS = 0). A case report

Despite the use of modern treatment methods for gastric cancer (GC), survival rates in locally advanced stages remain unsatisfactory. This necessitates the search for new therapeutic options and potential predictive factors for tailoring treatment approaches. The emergence of new molecular classifications like The Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG), leading to the identification of a distinct subset — gastric cancer with high microsatellite instability (MSI-H) caused by mismatch repair deficiency (dMMR), has paved the way for a novel treatment direction: immunotherapy. MSI status and PD-L1 expression are regarded as predictors of immunotherapy efficacy in GC. However, the question of which marker is more accurate or if they should be considered together remains unanswered. Furthermore, the efficacy of checkpoint inhibitor therapy is often attributed to increased PD-L1 expression in microsatellite unstable tumors compared to microsatellite stable ones. The article discusses a case demonstrating the high efficacy of immunochemotherapy, resulting in complete pathomorphological regression of the tumor in a patient with locally advanced gastric cancer and MSI-H status after neoadjuvant immunochemotherapy, despite the absence of PD-L1 expression (CPS-0). The patient has been monitored for 1.5 years post-treatment at the N. N. Blokhin National Medical Research Center of Oncology without signs of progression.

Discovery of Novel Hydrazide-Based HDAC3 Inhibitors as Epigenetic Immunomodulators for Cancer Immunotherapy.

Based on our previous work, a series of imidazole-based small molecules were designed and synthesized as HDAC3 inhibitors. Among them, compound SC26 showed selective HDAC3 inhibition activity with an IC50 of 53 nM (SI = 75 for HDAC3 over HDAC1). Further studies revealed that SC26 could dose-dependently induce the expression of PD-L1 in MC38 cells by activating the PD-L1 transcription. SC26 also showed high in vivo antitumor efficacy in a colorectal cancer model (50 mg/kg po, TGI = 63%). Importantly, the combination of SC26 with the PD-L1 inhibitor NP19 activated the immune system in tumor-bearing mice, enhancing the antitumor immune response (TGI = 80%, 50 + 50 mg/kg, p.o.). Collectively, we report for the first time that an HDAC3 inhibitor could upregulate PD-L1 expression in vitro and in vivo, specifically in MC38 cells and MC38-bearing tumors, and SC26 represents a novel epigenetic immunomodulator with potential applications in tumor immunotherapy.

Evaluation of EGFR-TKIs and ICIs treatment stratification in non-small cell lung cancer using an encrypted multidimensional radiomics approach

BackgroundRadiomics holds great potential for the noninvasive evaluation of EGFR-TKIs and ICIs responses, but data privacy and model robustness challenges limit its current efficacy and safety. This study aims to develop and validate an encrypted multidimensional radiomics approach to enhance the stratification and analysis of therapeutic responses.Materials and methodsThis multicenter study incorporated various data types from 506 NSCLC patients, which underwent preprocessing through anonymization methods and were securely encrypted using the AES-CBC algorithm. We developed one clinical model and three radiomics models based on clinical factors and radiomics scores (RadScore) of three distinct regions to evaluate treatment response. Additionally, an integrated radiomics-clinical model was created by combining clinical factors with RadScore. The study also explored the association between different EGFR mutations and PD-1/PD-L1 expression in radiomics biomarkers.FindingsThe radiomics-clinical model demonstrated high performance, with AUC values as follows: EGFR (0.884), 19Del (0.894), L858R (0.881), T790M (0.900), and PD-1/PD-L1 expression (0.893) in the test set. This model outperformed both clinical and single radiomics models. Decision curve analysis further supported its superior clinical utility. Additionally, our findings suggest that the efficacy of EGFR-TKIs and ICIs therapy may not depend on detecting a singular tumor feature or cell type.ConclusionThe proposed method effectively balances the level of evidence with privacy protection, enhancing the study’s validity and security. Therefore, radiomics biomarkers are expected to complement molecular biology analyses and guide therapeutic strategies for EGFR-TKIs, ICIs, and their combinations.

Pulsatilla saponin D inhibits invasion and metastasis of triple-negative breast cancer cells through multiple targets and pathways.

To explore the mechanism by which Pulsatilla saponin D (PSD) inhibits invasion and metastasis of triple-negative breast cancer (TNBC). The public databases were used to identify the potential targets of PSD and the invasion and metastasis targets of TNBC to obtain the intersection targets between PSD and TNBC. The "PSD-target-disease" interaction network was constructed and protein-protein interaction (PPI) analysis was performed to obtain the core targets, which were analyzed for KEGG pathway and GO functional enrichment. Molecular docking study of the core targets and PSD was performed, and the therapeutic effect and mechanism of PSD were verified using Transwell assay and Western blotting in cultured TNBC cells. Network pharmacology analysis identified a total of 285 potential PSD targets and 26 drug-disease intersection core targets. GO analysis yielded 175 entries related to the binding of biomolecules (protein, DNA and RNA), enzyme activities, and regulation of gene transcription. KEGG analysis yielded 46 entries involving pathways in cancer, chemical carcinogenesis-receptor activation, microRNAs in cancer, chemical carcinogenesis-reactive oxygen species, PD-L1 expression and PD-1 checkpoint pathway in cancer. Molecular docking showed high binding affinities of PSD to MTOR, HDAC2, ABL1, CDK1, TLR4, TERT, PIK3R1, NFE2L2 and PTPN1. In cultured TNBC cells, treatment with PSD significantly inhibited cell invasion and migration and lowered the expressions of MMP2, MMP9, N-cadherin and the core proteins p-mTOR, ABL1, TERT, PTPN1, HDAC2, PIK3R1, CDK1, TLR4 as well as NFE2L2 expressionin the cell nuclei. The inhibitory effects of PSD on TNBC invasion and metastasis are mediated by multiple targets and pathways.

Integrated multi-omics analyses of oral squamous cell carcinoma reveal precision patient stratification and personalized treatment strategies.

Oral cavity squamous cell carcinoma (OSCC), a leading subtype of head and neck cancer, exhibits high global incidence and mortality rates. Despite advancements in surgery and radiochemotherapy, approximately one-third of patients experience relapse. To improve current targeted and immunotherapy strategies for recurrent OSCC, we conducted multi-omics analyses on pretreatment OSCC samples (cohorts 1 and 2, n=137) and identified A3A and EGFR, both at the RNA and protein levels, as inversely expressed markers for patient stratification and response prediction. Survival analysis demonstrated that elevated A3A or PD-L1 expression levels correlated to improved responses to anti-PD-1 therapy in patients (cohort 3a, n=50, IHC). In contrast, high RRAS expression (cohort 4, n=252, qRT-PCR) was significantly associated with OSCC recurrence. Cell-based experiments revealed that RRAS was involved in radiotherapy and cisplatin resistance through the EGFR/RRAS/AKT/ERK signaling pathway. In OSCC patient-derived xenograft (PDX) mouse models, treatments with cisplatin and cetuximab (anti-EGFR) effectively reduced tumor size in EGFR-high-derived (#34) but not A3A-high-derived (#22) PDX tumors. Our study demonstrated that A3A-high tumors were immune-hot and responsive to anti-PD-1 therapy, whereas EGFR-high tumors exhibited chr.7p11.2 gains and DNA repair alterations. Additionally, RRAS-high tumors were associated with OSCC recurrence via AKT and ERK phosphorylation and demonstrate improved clinical outcomes with cetuximab therapy (cohort 3b, n=49, IHC). This study emphasizes the significance of A3A and EGFR expression levels in OSCC patient stratification and precision therapy, suggesting the use of anti-PD-1 or anti-EGFR treatments, respectively based on these biomarkers. Furthermore, RRAS emerges as a novel prognostic marker for local recurrence.

Effect of perioperative analgesia on immunity in lung cancer.

COX inhibitors are frequently used for pain management during the perioperative period and may influence tumor progression and the tumor microenvironment by modulating inflammation and immune responses. This study investigates the effects of COX inhibitors on tumor growth and the immune microenvironment. In vivo experiments demonstrate that COX inhibitors can reduce tumor cell growth, elevate PD-L1 expression on tumor cells, and enhance the proportion of myeloid cells within the tumor immune microenvironment. Furthermore, COX inhibitors are found to improve the efficacy of the immune checkpoint inhibitor anti-PD-L1. These results underscore the influence of perioperative COX inhibitors on tumor immunity and suggest potential new strategies for optimizing tumor immunotherapy.

FAP upregulates PD-L1 expression in cancer-associated fibroblasts to exacerbate T cells dysfunction and suppress anti-tumor immunity.

FAP-positive cancer-associated fibroblasts (CAFs), recognized as a critical subset of CAFs, have been implicated in fostering an immunosuppressive tumor microenvironment in various cancers. However, their potential mechanisms of immunosuppression, particularly in modulating T cells, remain elusive. In this study, multiple internal cohorts consisting of 328 patients as well as 5 external cohorts were integrated to delineate the association between unfavorable prognosis or therapeutic resistance and FAP+ CAFs in gastric cancer patients. Subsequently, using in vivo mice models and in vitro co-culture system, we found that elevated infiltration levels of FAP+ CAF exacerbated immunosuppression in the tumor microenvironment by facilitating CD8+ T cells dysfunction. Mechanistically, FAP impeded the degradation of STAT1 protein in CAFs, thereby sustaining PD-L1 transcription and fostering T cell exhaustion. Treatment with PD-L1 neutralizing antibodies effectively attenuated FAP-mediated immunosuppression, restoring anti-tumor immunity of T cells. Overall, our findings underscore the vital role of FAP+ CAFs in directly suppressing T cell-mediated anti-tumor immunity via PD-L1 upregulation, paving the way for the development of FAP-targeted therapies in clinical settings.