Programmed Death-ligand 1 Expression Research Articles

The efficacy and safety of neoadjuvant immunochemotherapy in resectable stage I-III non-small cell lung cancer: a systematic review and network meta-analysis.

Neoadjuvant immunochemotherapy (NICT) is a new treatment method for resectable non-small-cell lung cancer (NSCLC). Network meta-analysis assessed efficacy, safety, and optimal treatment. We searched for randomized controlled trials (RCTs) comparing NICT with neoadjuvant chemotherapy (NCT) in PubMed, Embase, Web of Science, Cochrane Library, and international conferences. Outcomes were surgical resection rate, pathological complete response(pCR),event-free survival (EFS), and Grade 3-5 treatment-related adverse events (TRAEs). RCTs of 3,387 patients, six treatment combinations, and two modalities were included. Meta-analysis showed that NICT yielded higher pCR and EFS rates than NCT. The toripalimab-chemotherapy combination had the highest surgical resection rate (OR = 1.68, 95% CI: 1.05-2.73), pCR (OR = 38.84, 95% CI: 11.05-268.19) and EFS (HR = 0.40, 95% CI: 0.28-0.58).This regimen worked well for patients with low programmed death-ligand 1 (PD-L1) expression or squamous cell pathology. For high PD-L1 expression and patients with NSCLC, neoadjuvant nivolumab with chemotherapy had the most efficacy. The incidence of treatment-related adverse events increased with longer treatment cycles, with perioperative nivolumab combined with chemotherapy showing the worst safety profile (RR = 1.32, 95% CI: 1.00-1.76), while neoadjuvant nivolumab combined with chemotherapy alone had the best safety profile (RR = 0.91, 95% CI: 0.68-1.21). Indirect comparison showed no survival benefit for neoadjuvant-adjuvant immunotherapy (HR = 0.93, 95% CI: 0.65-1.35). In the indirect comparison between the two immune checkpoint inhibitors(ICIs), although there was no significant difference in EFS (HR = 0.81, 95% CI: 0.61-1.08), PD-1 inhibitors may still be the most effective treatment option. NICT effectively and safely treats resectable NSCLC. The optimal treatment combination is typically toripalimab and chemotherapy. Treatment based on PD-L1 expression and pathological type is recommended.

Zosuquidar Promotes Antitumor Immunity by Inducing Autophagic Degradation of PD-L1.

The intracellular distribution and transportation process are essential for maintaining PD-L1 (programmed death-ligand 1) expression, and intervening in this cellular process may provide promising therapeutic strategies. Here, through a cell-based high content screening, it is found that the ABCB1 (ATP binding cassette subfamily B member 1) modulator zosuquidar dramatically suppresses PD-L1 expression by triggering its autophagic degradation. Mechanistically, ABCB1 interacts with PD-L1 and impairs COP II-mediated PD-L1 transport from ER (endoplasmic reticulum) to Golgi apparatus. The treatment of zosuquidar enhances ABCB1-PD-L1 interaction and leads the ER retention of PD-L1, which is subsequently degraded in the SQSTM1-dependent selective autophagy pathway. In CT26 mouse model and a humanized xenograft mouse model, zosuquidar significantly suppresses tumor growth and accompanies by increased infiltration of cytotoxic T cells. In summary, this study indicates that ABCB1 serves as a negative regulator of PD-L1, and zosuquidar may act as a potential immunotherapy agent by triggering PD-L1 degradation in the early secretory pathway.

Cannabidiol enhances Atezolizumab efficacy by upregulating PD-L1 expression via the cGAS-STING pathway in triple-negative breast cancer cells.

The treatment of patients with triple negative breast cancer (TNBC) relies on cytotoxic therapy. Currently, atezolizumab and chemotherapy can be combined in patients with TNBC. However, this approach is not effective for all patients with low reactivity to atezolizumab. As there is a lack of alternative treatment options, new anti-cancer drugs are urgently needed to enhance atezolizumab reactivity against TNBC. Recent strategies have focused on regulating the expression of programmed death-ligand 1 (PD-L1) or enhancing immune response activation by combining anti-cancer drugs with immune checkpoint inhibitors (ICIs). Cannabidiol (CBD), a cannabinoid component derived from the cannabis plant, has been reported to have anti-cancer therapeutic potential because of its capacity to induce apoptotic cell death in tumor cells while avoiding cytotoxicity in normal cells. Previous studies have demonstrated the effects of CBD on apoptosis in various cancer cell types. However, the potential role of CBD as an immune modulator in the regulation of PD-L1 expression and anti-cancer immune responses remains to be explored. In this study, we found that CBD stimulated PD-L1 expression in TNBC cells, which significantly induced the CBD-mediated cGAS-STING pathway activation. Taken together, we demonstrated that the combination of CBD and anti-PD-L1 antibody enhances the anti-cancer immune response in vitro and in vivo experiments. Our findings identified the mechanism of PD-L1 regulation by CBD in TNBC cells and suggested that CBD could be a potential candidate for the development of new combinatorial strategies with ICIs in TNBC patients.

The expression of programmed cell death ligand 1 (PD-L1) involves in the clinicopathologic characteristics and prognostic implications of testicular germ cell tumor (TGCT): a systematic review and meta-analysis.

Testicular germ cell tumor (TGCT) is a type of tumor with relatively lower incidence but being more prevalent in young men. The expression of programmed cell death ligand 1 (PD-L1) serves as a potential biomarker for predicting the survival outcomes of other tumors. Some studies discovered higher prevalence of PD-L1 in TGCT patients who achieved favorable treatment outcomes, while other studies showed lower or absent expression of PD-L1 in TGCT with the better prognosis as well. Therefore, in order to address this controversy and clarify the association between the expression of PD-L1 and pathological features and prognosis of TGCT, this meta-analysis was conducted. A comprehensive literature search was performed using following search terms: "testis", "testicle", "testicular", "cancer", "carcinoma", "tumor", "neoplasm", "programmed cell death ligand 1", "programmed death ligand 1", "PD-L1", "PDL1", "B7 homolog 1", "B7-H1", "B7H1" and "CD274". Relevant studies were retrieved according to the inclusion criteria from reputable databases including PubMed, Embase, Web of Science, Cochrane Library and China National Knowledge Infrastructure (CNKI). These studies investigated the expression of PD-L1 in both tumor cells and tumor infiltrating immune cells (TIICs) in TGCT. The overall proportion of PD-L1 positivity was assessed using R programming. Pooled hazard ratio (HR) and odds ratio (OR) with corresponding 95% confidence interval (CI) were calculated using Revman software to evaluate the involvement of PD-L1 expression in TGCT. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality assessment of included studies. Sensitivity analysis and publication bias evaluation were subsequently performed. A total of eight eligible studies compromising 1,589 patients diagnosed with TGCT were finally included in this study. PD-L1 positivity was detected in 31% and 41% of TGCT patients' tumor cells and TIICs, respectively. The pooled data demonstrated a significant association between elevated PD-L1 expression levels in TIICs and a favorable prognosis characterized by the reduced disease progression and relapse events (HR =0.21, 95% CI: 0.13-0.33). Furthermore, PD-L1+ TIICs exhibited higher prevalence rates in seminoma (OR =2.11, 95% CI: 1.57-2.84) and embryonal carcinoma (OR =6.23, 95% CI: 2.42-16.02) patients. Notably, PD-L1 expression in TIICs displayed a tendency to increase in TGCT patients with lower stages or without lymph node metastasis. PD-L1 expression was observed in choriocarcinoma tumor cells, while yolk sac tumor and teratoma tumor cells exhibited lower or absent expression of PD-L1. Conversely, PD-L1 expression in TIICs was associated with seminoma and embryonal carcinoma, which was more commonly observed in TGCT patients with lower stages and better prognosis, thereby providing a theoretical foundation for the application of immunotherapy in relapsed/refractory TGCT patients.

Efficacy and safety of immune checkpoint inhibitors plus platinum-etoposide vs. platinum-etoposide in the first-line treatment of extensive-stage small cell lung cancer: a systematic review and a meta-analysis.

Currently, immune checkpoint inhibitors (ICIs) combined with platinum-etoposide (EP) are gradually becoming the first-line standard treatment for extensive-stage small cell lung cancer (ES-SCLC). This meta-analysis aims to compare the efficacy and safety of ICIs combined with EP vs. EP alone in the first-line treatment of ES-SCLC. We searched PubMed, Embase, and Cochrane Library databases for phase II/III randomized controlled trials (RCTs) that met inclusion criteria from January 2016 to November 2023. Outcome measures included progression-free survival (PFS), overall survival (OS), objective response rate (ORR), treatment-related adverse events (TRAEs), treatment-related serious adverse events (TRSAEs), and immune-related adverse events (IRAEs). The effect analysis statistics of the outcome indicators were expressed with hazard ratio (HR) and odds ratio (OR) and their 95% confidence interval (CI). This study included nine RCTs with a total of 4,711 patients. Compared to EP, ICIs plus EP improved patients' PFS (HR =0.71; 95% CI: 0.64-0.79; P<0.001), OS (HR =0.79; 95% CI: 0.74-0.84; P<0.001), and ORR (OR =1.27; 95% CI: 1.12-1.44; P=0.001), but increased the incidence of adverse events (AEs): TRAEs (OR =1.45; 95% CI: 1.20-1.76; P<0.001), IRAEs (OR =3.97; 95% CI: 2.49-6.32; P<0.001), and grade 3-4 IRAEs (OR =6.17; 95% CI: 2.36-16.15; P<0.001). However, there was no significant difference in the incidence of grade 3-4 TRAEs (OR =1.05; P=0.54), TRSAEs (OR =1.40; P=0.13), and grade 3-4 TRSAEs (OR =1.17; P=0.72). Subgroup analysis found that patients with brain metastasis did not benefit from ICIs combined with EP therapy, and patients with programmed cell death ligand 1 (PD-L1) expression ≥1% had poorer survival benefits compared to patients with PD-L1 expression <1%. In the first-line treatment of ES-SCLC, compared to EP chemotherapy, ICIs with EP can benefit patients in terms of PFS, OS, and ORR, but it will increase the occurrence of AEs.

Study on the mechanism of liver cancer immune escape mediated by MINDY1 through regulation of PD-L1 ubiquitination level.

The novel deubiquitinase enzyme, motif interacting with ubiquitin-containing novel DUB family-1 (MINDY1), is highly expressed in liver cancer tissues and plays a crucial role in maintaining the stemness of liver cancer cells. Programmed death ligand-1 (PD-L1) is an immunosuppressive molecule overexpressed by tumour cells. The potential role of MINDY1 in inhibiting the stemness of liver cancer cells by deubiquitinating PD-L1 has not yet been reported. To investigate the mechanism by which MINDY1 mediates immune escape in liver cancer through the regulation of PD-L1 ubiquitination, we examined the expression levels of MINDY1 and PD-L1 in liver cancer and adjacent tissues from 50 hepatocellular carcinoma (HCC) patients using protein imprinting and immunohistochemistry. We analyzed the relationship between the expression levels of MINDY1 and PD-L1 in liver cancer tissues and their correlation with the 5-year tumor-free survival rates of patients. Subsequently, MINDY1 expression was knocked down in Huh7 cells using small interfering RNA (siRNA) interference or upregulated through transfection with a MINDY1 overexpression plasmid. The effects of MINDY1 knockdown or overexpression on the proliferation, apoptosis, migration, and invasion of HCC cells, as well as the regulation of PD-L1 binding and ubiquitination, were assessed. The 5-year tumor-free survival rates were significantly lower in both the high MINDY1 expression group and the high PD-L1 expression group (χ2 = 4.919 and 13.158, respectively).A significant difference in survival was observed between the high and low MINDY1 expression groups (χ2= 27.415). MINDY1 was found to directly interact with PD-L1, with MINDY1 gene knockdown promoting PD-L1 ubiquitination and MINDY1 overexpression inhibiting PD-L1 ubiquitination. All comparisons yielded statistically significant results (P < 0.05). In conclusion, MINDY1 inhibits the malignant progression of liver cancer by inhibiting PD-L1 ubiquitination and mediating immune escape.

Preliminary Research of Radiolabeled Atezolizumab for the Noninvasive Evaluation of TNBC PD-L1 Expression InVivo.

Programmed death-ligand 1 (PD-L1) expression is related to the efficacy and prognosis in triple-negative breast cancer. This study employed an indirect labeling method to synthesize [125I]PI-Atezolizumab. The invitro stability of [125I]PI-Atezolizumab was assessed through incubation in phosphate buffered saline and fetal bovine serum, revealing sustained stability. Specific binding of [125I]PI-Atezolizumab to MDA-MB-231 cells expressing humanized PD-L1 was assessed through invitro incubation, yielding a Kd value comparable to that of Atezolizumab. This suggests that the labeling process did not compromise the affinity of the Atezolizumab to PD-L1. Subsequently, pharmacokinetic studies were conducted in normal mice and biodistribution experiments in tumor-bearing mice. A comparison of the biodistribution results between [125I]PI-Atezolizumab and 125I-labeled Atezolizumab indicated better invivo stability for the former. Single photon emission computed tomography (SPECT)/CT imaging further confirmed the targeted specificity of [125I]PI-Atezolizumab for PD-L1 in MDA-MB-231 xenografts, which were validated by immunohistochemistry staining. This research underscores the utility of [125I]PI-Atezolizumab, prepared via indirect labeling, for monitoring PD-L1 in triple-negative breast cancer models.

Activatable near-infrared fluorescence probe for real-time imaging of PD-L1 expression in tumors.

In clinical practice, determining programmed death-ligand 1 (PD-L1) expression is crucial for selecting patients and monitoring immune checkpoint blockade therapies. Currently, PD-L1 expression is quantified using immunohistochemistry (IHC). However, IHC-based methods do not capture the heterogeneous and dynamic nature of PD-L1 expression. Thus, there is a pressing need for a rapid and efficient method for monitoring PD-L1 expression both in vitro and in vivo, which would considerably aid in prognosis and treatment selection. In this study, we present for the first time an activatable near-infrared (NIR) fluorescence imaging probe (Q-Atezol) for the real-time monitoring of PD-L1 expression in vitro and in vivo. The ability of Q-Atezol to detect PD-L1 expression quickly and in real-time was evaluated in both tumor spheroid and lung cancer xenograft models. An always-on optical probe (ON-Atezol) was synthesized and tested for comparison. In vivo NIR fluorescence imaging studies were conducted on A549 and H1975 tumor-bearing mice, and their tumor-to-background ratios (TBRs) were analyzed. The quenched NIR fluorescence of Q-Atezol is activated upon binding to PD-L1 proteins on the surface of cancer cells, thereby enabling PD-L1 detection in the three-dimensional (3D) tumor spheroids without a washing step. Notably, PD-L1-positive H1975 tumors were clearly visualized with a high TBR 6 hours after Q-Atezol injection, whereas ON-Atezol treatment could not detect H1975 tumors even 24 hours post-injection. The activatable fluorescence probe Q-Atezol demonstrated great potential as an exceptional sensor for assessing PD-L1 expression in 3D cell structures and for in vivo applications.

PD-L1 expression as a predictive biomarker in patients with recurrent or metastatic salivary gland carcinoma treated with pembrolizumab

Although immune checkpoint inhibitors (ICIs) are effective in some patients with salivary gland carcinoma (SGC), biomarkers which predict the efficacy and prognosis of SGC patients treated with pembrolizumab have not been identified. We conducted a multi-institutional retrospective cohort study to evaluate the efficacy and safety of pembrolizumab monotherapy in patients with recurrent and/or metastatic SGC and to determine optimal cut-off values of the combined positive score (CPS) and tumor proportion score (TPS) as numerical expression levels of programmed death-ligand 1 (PD-L1), which predict the efficacy of pembrolizumab. Furthermore, we investigated the association of patient characteristics and hematological markers with clinical outcomes, including overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). From 2016 to 2021, 27 patients were included in the analysis. ORR of SGC was 25.9%. Optimal cut-off values of CPS and TPS were 15 and 25%, respectively. ORRs of CPS-high and TPS-high were 55.6 and 75.0%, respectively, and significantly higher than those of CPS-low and TPS-low. Furthermore, patients with a low platelet-lymphocyte ratio (PLR) had a significantly longer PFS. No grade 4 or greater adverse events were observed. This study demonstrated the efficacy and safety of pembrolizumab monotherapy and identified optimal cut-off values of CPS and TPS.

ROS-sensitive PD-L1 siRNA cationic selenide nanogels for self-inhibition of autophagy and prevention of immune escape

In the field of cancer therapy, inhibiting autophagy has emerged as a promising strategy. However, pharmacological disruption of autophagy can lead to the upregulation of programmed death-ligand 1 (PD-L1), enabling tumor immune evasion. To address this issue, we developed innovative ROS-responsive cationic poly(ethylene imine) (PEI) nanogels using selenol chemistry-mediated multicomponent reaction (MCR) technology. This procedure involved simple mixing of low-molecular-weight PEI (LMW PEI), γ-selenobutylacetone (γ-SBL), and poly(ethylene glycol) methacrylate (PEGMA). Through high-throughput screening, we constructed a library of AxSeyOz nanogels and identified the optimized A1.8Se3O0.5/siPD-L1 nanogels, which exhibited a size of approximately 200 nm, excellent colloidal stability, and the most effective PD-L1 silencing efficacy. These nanogels demonstrated enhanced uptake by tumor cells, excellent oxidative degradation ability, and inhibited autophagy by alkalinizing lysosomes. The A1.8Se3O0.5/siPD-L1 nanogels significantly downregulated PD-L1 expression and increased the expression of major histocompatibility complex class I (MHC-I), resulting in robust proliferation of specific CD8+ T cells and a decrease in MC38 tumor growth. As a result, the A1.8Se3O0.5/siPD-L1 nanogels inhibited tumor growth through self-inhibition of autophagy, upregulation of MHC-I, and downregulation of PD-L1. Designed with dynamic diselenide bonds, the A1.8Se3O0.5/siPD-L1 nanogels showed synergistic antitumor efficacy through self-inhibition of autophagy and prevention of immune escape.

No Correlation between PD-L1 and NIS Expression in Lymph Node Metastatic Papillary Thyroid Carcinoma.

Approximately 90% of thyroid cancers are differentiated thyroid cancers (DTCs), originating from follicular epithelial cells. Out of these, 90% are papillary thyroid cancer (PTC), and 10% are follicular thyroid cancer (FTC). The standard care procedure for PTC includes surgery, followed by radioiodine (RAI) ablation and thyroid-stimulating hormone (TSH) suppressive therapy. Globally, treating radioiodine-refractory DTC poses a challenge. During malignant transformation, thyroid epithelial cells often lose their ability to absorb radioiodine due to impaired membrane targeting or lack of NIS (sodium/iodide symporter) expression. Recent reports show an increase in PD-L1 (programmed death ligand 1) expression in thyroid cancer cells during dedifferentiation. However, no research exists wherein NIS and PD-L1 expression are analyzed together in thyroid cancer. Therefore, we aimed to investigate and correlate PD-L1 and NIS expression within primary tumor samples of lymph node metastatic PTC. We analyzed the expression of hNIS (human sodium/iodide symporter) and PD-L1 in primary tumor samples from metastatic PTC patients using immunohistochemistry. Immunohistochemistry analysis of PD-L1 and NIS was conducted in 89 and 86 PTC cases, respectively. Any subcellular NIS localization was counted as a positive result. PD-L1 expression was absent in 25 tumors, while 58 tumors displayed PD-L1 expression in 1-50% of their cells; in 6 tumors, over 50% of the cells tested positive for PD-L1. NIS immunohistochemistry was performed for 86 primary papillary carcinomas, with 51 out of 86 tumors showcasing NIS expression. Only in seven cases was NIS localized in the plasma membrane; in most tumors, NIS was primarily found in the intracytoplasmic membrane compartments. In the case of PD-L1 staining, cells showing linear membrane positivity of any intensity were counted as positive. The evaluation of NIS immunostaining was simpler: cells showing staining of any intensity of cytoplasmic or membranous fashion were counted as positive. The number of NIS positive cells can be further divided into cytoplasmic and membrane positive compartments. There was no observed correlation between PD-L1 and NIS expression. We can speculate that the manipulation of the PD-1/PD-L1 axis using anti-PD-L1 or anti-PD-1 antibodies could reinstate the functional expression of NIS. However, based on our study, the only conclusion that can be drawn is that there is no correlation between the percentage of NIS- or PD-L1-expressing tumor cells in the primary tumor of lymph node metastatic PTC.

The prognostic value of programmed death-ligand 1 (PD-L1) expression in resected colorectal cancer without neoadjuvant therapy - differences between antibody clones and cell types

BackgroundProgrammed death-ligand 1 (PD-L1) expression on tumor cells is associated with poor prognosis in several malignancies, while partly contradictory and inconclusive results have been presented for colorectal cancer (CRC). This study aimed to evaluate PD-L1 as a prognostic biomarker in CRC by comparing three different antibody clones.MethodsPatients surgically treated for CRC between January 1st, 2007, and December 31st, 2015, in Kalmar County, Sweden, were retrospectively included. Tissue microarrays from 862 primary tumors without neoadjuvant treatment were assessed for immunohistochemical expression of PD-L1 in tumor cells (TC) and immune cells (IC) using clones 73-10, SP263, and 22C3. Cox regression proportional hazard models were used to estimate hazard ratios for overall survival (OS) and disease-free interval (DFI) in univariable and multivariable analyses, with 1% and 5% set as cut-offs for positive expression in TC and IC respectively.ResultsPD-L1 expression in TC was found in 89 (10%) cases for clone 73-10, 76 (9%) for clone SP263, and 38 (4%) for clone 22C3, while the numbers for IC were 317 (37%) cases for clone 73-10, 264 (31%) for clone SP263, and 89 (10%) for clone 22C3. PD-L1 expression in IC was associated with prolonged OS and DFI in univariable analysis for all three clones. The link to prolonged DFI remained in multivariable analysis for 73-10 and SP263, but only for 73-10 regarding OS. PD-L1 expression in TC was not prognostic of OS in any analysis, while it was associated with prolonged DFI for SP263, and a trend was seen for 73-10. The link to prolonged DFI remained for SP263 and was strengthened for 73-10 in multivariable analysis.ConclusionsThe prognostic value of PD-L1 expression in both IC and TC differs between antibody clones, with 73-10 and SP263 being more reliable for prognostic information than 22C3 in resected CRC.

Multispectral fluorescence imaging of EGFR and PD-L1 for precision detection of oral squamous cell carcinoma: a preclinical and clinical study

BackgroundEarly detection and treatment are effective methods for the management of oral squamous cell carcinoma (OSCC), which can be facilitated by the detection of tumor-specific OSCC biomarkers. The epidermal growth factor receptor (EGFR) and programmed death-ligand 1 (PD-L1) are important therapeutic targets for OSCC. Multispectral fluorescence molecular imaging (FMI) can facilitate the detection of tumor multitarget expression with high sensitivity and safety. Hence, we developed Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes, in combination with multispectral FMI, to sensitively and noninvasively identify EGFR and PD-L1 expression for the detection and comprehensive treatment of OSCC.MethodsThe expression of EGFR and PD-L1 was analyzed using bioinformatics data sources and specimens. Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes were developed and tested on preclinical OSCC cell line and orthotopic OSCC mouse model, fresh OSCC patients’ biopsied samples, and further clinical mouthwash trials were conducted in OSCC patients.ResultsEGFR and PD-L1 were specifically expressed in human OSCC cell lines and tumor xenografts. Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes can specifically target to the tumor sites in an in situ human OSCC mouse model with good safety. The detection sensitivity and specificity of Nimotuzumab-ICG in patients were 96.4% and 100%, and 95.2% and 88.9% for Atezolizumab-Cy5.5.ConclusionsEGFR and PD-L1 are highly expressed in OSCC, the combination of which is important for a precise prognosis of OSCC. EGFR and PD-L1 expression can be sensitively detected using the newly synthesized multispectral fluorescence imaging probes Nimotuzumab-ICG and Atezolizumab-Cy5.5, which can facilitate the sensitive and specific detection of OSCC and improve treatment outcomes.Trial registrationChinese Clinical Trial Registry, ChiCTR2100045738. Registered 23 April 2021, https://www.chictr.org.cn/bin/project/edit?pid=125220

PD-L1 expression and tumor-infiltrating lymphocytes: Correlations and prognostic values in Chinese triple-negative breast cancer patients with different molecular subtyping

ObjectiveTo investigate the correlation between programmed death ligand-1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs) and evaluate the prognostic value of PD-L1 and TILs in Chinese triple-negative breast cancer (TNBC) patients with different molecular subtype MethodsThis retrospective study was conducted at 2020. Specifically, the pre-chemotherapy clinical data and non-stained tissue blocks of 465 TNBC patients visited the Fudan University Shanghai Cancer Center (FUSCC) between 2008 and 2014 were collected, with their blocks sliced and stained using PD-L1(SP142), and the outcome of subsequent chemotherapy obtained in 2020. The relapse-free survival (RFS) of the study population was calculated. The baseline PD-L1 expression status correlations with TILs and molecular subtypes were assessed using Spearman’s rank correlation analysis and the Kruskal-Wallis test. Kaplan-Meier survival analyses were undertaken to evaluate the prognosis value of TILs and PD-L1 expression. ResultsPD-L1 expression status on IC was moderately and positively correlated with stromal tumor-infiltrating lymphocytes (sTILs) (rs = 0.502, P <0.001) and iTILs (rs = 0.410, P < 0.001), respectively. PD-L1 expression status and TILs showed significant differences among molecular subtypes (P < 0.001), with the highest proportion of PD-L1+ and high TILs patients observed in the immunomodulatory (IM) subtype. TILs were significantly associated with RFS. Moreover, sTILs could act as an independent predictor of RFS (RR 0.953, 95 % CI 0.920 ∼ 0.987, P = 0.007), while PD-L1 expression status did not show the same prognostic significance. ConclusionsThe incorporation of pre-treatment TILs and PD-L1 expression status as valuable tools for optimizing patient selection for immunotherapy and managing the risks associated with chemotherapy in Chinese TNBC patients. Data availabilityThe data sets generated and analyzed during the current study are available from the corresponding author.

Hexokinase HK3-mediated O-GlcNAcylation of EP300: a key regulator of PD-L1 expression and immune evasion in ccRCC

Clear cell renal cell carcinoma (ccRCC) demonstrates enhanced glycolysis, critically contributing to tumor development. Programmed death-ligand 1 (PD-L1) aids tumor cells in evading T-cell-mediated immune surveillance. Yet, the specific mechanism by which glycolysis influences PD-L1 expression in ccRCC is not fully understood. Our research identified that the glycolysis-related gene (GRG) HK3 has a unique correlation with PD-L1 expression. HK3 has been identified as a key regulator of O-GlcNAcylation in ccRCC. O-GlcNAcylation exists on the serine 900 (Ser900) site of EP300 and can enhance its stability and oncogenic activity by preventing ubiquitination. Stably expressed EP300 works together with TFAP2A as a co-transcription factor to promote PD-L1 transcription and as an acetyltransferase to stabilize PD-L1 protein. Furthermore, ccRCC exhibits interactive dynamics with tumor-associated macrophages (TAMs). The uridine 5′-diphospho-N-acetylglucosamine (UDP-GlcNAc), which serves as a critical substrate for the O-GlcNAcylation process, facilitates TAMs polarization. In ccRCC cells, HK3 expression is influenced by IL-10 secreted by M2 TAMs. Our study elucidates that HK3-mediated O-GlcNAcylation of EP300 is involved in tumor immune evasion. This finding suggests potential strategies to enhance the efficacy of immune checkpoint blockade therapy.

Bioorthogonal Diels-Alder Click Chemistry-Based Pretargeted PET Imaging Strategy for Monitoring Programmed Death-Ligand 1 Expression.

The development of antibody tracers for positron emission tomography (PET) imaging enables real-time monitoring of tumor expression of programmed cell death ligand 1 (PD-L1) in vivo, aiming to facilitate the selection of immunotherapy responders. However, the slow pharmacokinetics of the antibodies in vivo limits their applications in PET imaging with commonly used radionuclides with short half-lives. In this study, we developed a pretargeted PET imaging strategy based on Diels-Alder (IEDDA) click chemistry to overcome these limitations. Atezolizumab and durvalumab, the most commonly used PD-L1 antibodies in cancer immunotherapy, were selected and compared in the development of the pretargeted PET imaging strategy. Fluorine-18-labeled derivatives of methyl tetrazine ([18F]Tz, [18F]PEG6-Tz, and [18F]PEG12-Tz) were tested in biodistribution and PET imaging of A549-PDL1 xenografts (PD-L1 positive) pretargeted with the trans-cyclooctene (TCO)-functionalized atezolizumab/durvalumab. The biodistribution and imaging results indicated that atezolizumab-TCO/[18F]PEG12-Tz was more suitable for pretargeted PET imaging strategy, and the optimal interval time was 48 h after atezolizumab-TCO administration, where the atezolizumab-TCO/[18F]PEG12-Tz pretargeted approach clearly delineated the A549-PDL1 tumor with a tumor-to-muscle ratio of 5.33, while the ratios are 3.39 and 2.39 for durvalumab/[18F]PEG12-Tz and mock-pretargeting controls, respectively. In conclusion, a pretargeted 18F-immuno-PET imaging technology was successfully established on atezolizumab. The high-contrast PET images of the A549-PDL1 tumor models demonstrate that the pretargeting strategy incorporating short-lived fluorine-18 is viable in identifying tumors with high PD-L1 expression, marking this strategy as a potential candidate for further clinical translation.

PD-L1 expression associates with favorable survival of patients with cancer of unknown primary (CUP) not treated with checkpoint inhibitors

PurposeCancer of unknown primary (CUP) is a heterogeneous entity with limited overall survival (OS) in most patients. Prognostic biomarkers are needed, particularly for treatment stratification. We investigated the impact of programmed death-ligand 1 (PD-L1) expression as prognostic marker in immunotherapy-naïve CUP patients. MethodsClinical data from patients with confirmed CUP diagnosis according to ESMO guidelines, treated at the West German Cancer Center, Essen from 2015 to 2021, were analyzed. Patients treated with checkpoint inhibitors were excluded. PD-L1 expression was assessed in tumor tissues following established guidelines. ResultsOf a cohort of 132 patients, 62 patients, including 30 patients with prognostically unfavorable CUP, met inclusion criteria and were evaluable for PD-L1 expression. Comparing PD-L1 Tumor Proportional Score (TPS) and Combined Positive Score (CPS) revealed almost complete concordance (96.2 %). Patients with PD-L1-positive CUP (TPS ≥1 %; n = 36; 58 %) had superior overall survival (median not reached) as compared to patients with PD-L1-negative CUP (median 14 months, 95 %CI 10.0–18.0; HR 0.3, p < 0.001). The benefit of PD-L1 positivity (n = 12; 40 %) was maintained in the unfavorable CUP subgroup (median 20 months, 95 %CI 3.0–37.0 versus 10 months, 95 %CI 3.1–16.9; HR 0.4, p = 0.032). In PD-L1-positive CUP there was a positive correlation between the level of PD-L1 expression and survival (TPS ≥50 %: median survival not reached, HR 0.1; TPS 1 to 49 %: OS: 77 months, HR 0.4). ConclusionPD-L1 expression associates with favorable survival in checkpoint inhibitor-naïve CUP patients. This implies a role of cancer immunity in CUP biology and may nominate PD-L1 for patient stratification in further studies and clinical care.

Three-dimensional iodine mapping quantified by dual-energy CT for predicting programmed death-ligand 1 expression in invasive pulmonary adenocarcinoma

We examined the association between texture features using three-dimensional (3D) io-dine density histogram on delayed phase of dual-energy CT (DECT) and expression of programmed death-ligand 1 (PD-L1) using immunostaining methods in non-small cell lung cancer. Consecutive 37 patients were scanned by DECT. Unenhanced and enhanced (3 min delay) images were obtained. 3D texture analysis was performed for each nodule to obtain 7 features (max, min, median, mean, standard deviation, skewness, and kurtosis) from iodine density mapping and extracellular volume (ECV). A pathologist evaluated a tumor proportion score (TPS, %) using PD-L1 immunostaining: PD-L1 high (TPS ≥ 50%) and low or negative expression (TPS < 50%). Associations between PD-L1 expression and each 8 parameter were evaluated using logistic regression analysis. The multivariate logistic regression analysis revealed that skewness and ECV were independent indicators associated with high PD-L1 expression (skewness: odds ratio [OR] 7.1 [95% CI 1.1, 45.6], p = 0.039; ECV: OR 6.6 [95% CI 1.1, 38.4], p = 0.037). In the receiver-operating characteristic analysis, the area under the curve of the combination of skewness and ECV was 0.83 (95% CI 0.67, 0.93) with sensitivity of 64% and specificity of 96%. Skewness from 3D iodine density histogram and ECV on dual energy CT were significant factors for predicting PD-L1 expression.

The expression of PD-L1 on tumor-derived exosomes enhances infiltration and anti-tumor activity of αCD3 × αPD-L1 bispecific antibody-armed T cells

Anti-cluster of differentiation (CD) 3 × α programmed death-ligand 1 (PD-L1) bispecific T-cell engager (BsTE)-bound T-cells (BsTE:T) are a promising new cancer treatment agent. However, the mechanisms of action of bispecific antibody-armed activated T-cells are poorly understood. Therefore, this study aimed to investigate the anti-tumor mechanism and efficacy of BsTE:T. The BsTE:T migration was assessed in vivo and in vitro using syngeneic and xenogeneic tumor models, flow cytometry, immunofluorescence staining, transwell migration assays, microfluidic chips, Exo View R100, western blotting, and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 technology. In murine B16 melanoma, MC38 colon cancer, and human multiple myeloma cells, BsTE:T exhibited superior tumor elimination relative to that of T-cells or BsTE alone. Moreover, BsTE:T migration into tumors was significantly enhanced owing to the presence of PD-L1 in tumor cells and secretion of PD-L1-containing exosomes. Furthermore, increased infiltration of CD44highCD62Llow effector memory CD8+ T-cells into tumors was closely associated with the anti-tumor effect of BsTE:T. Therefore, BsTE:T is an innovative potential anti-tumor therapy, and exosomal PD-L1 plays a crucial role both in vitro and in vivo in the anti-tumor activity of BsTE:T.Graphical abstract

Transarterial Embolization Enhances Programmed Cell Death Ligand 1 Expression and Influences CD8+T Lymphocytes Cytotoxicity in an Orthotopic Hepatocellular Carcinoma Rat Model.

To investigate the influence of transarterial embolization (TAE) on programmed cell death-ligand 1(PD-L1) expression and CD8+T tumour infiltrative lymphocyte cytotoxicity in the Sprague-Dawley (SD) rat model of hepatocellular carcinoma (HCC). An orthotopic HCC model was established in twenty SD rats treated with TAE (lipiodol, n = 10) or sham (normal saline, n = 10) using homologous N1S1 hepatoma cells. Rats were euthanized 1week after embolization. Flow cytometry was used to assess the proportion of CD4+T, CD8+T and programmed cell death-1+(PD-1+) CD8+T lymphocytes in the spleens and tumours. Distribution of CD8+T, granzyme-B+CD8+T lymphocytes and PD-L1+ cells was assessed by immunohistochemistry (IHC) or multiplex IHC. p value < 0.05 was considered statistically significant. The CD4/CD8 ratio and PD-1+CD8+ T lymphocytes exhibited higher values in TAE-treated tumours compared to sham-treated tumours (p = 0.021 and p = 0.071, respectively). Conversely, the number of CD8+T lymphocytes was decreased in TAE-treated tumours (p = 0.043), especially in the central region (p = 0.045). However, more CD8+T lymphocytes were found infiltrating the marginal region than central region in TAE-treated tumours (p = 0.046). The proportion of granzyme-B+CD8+T lymphocytes and the PD-L1 positive areas was elevated in tumours that treated with TAE (p all < 0.05). There was a negative correlation between PD-L1 expression and the number of infiltration of CD8+ T lymphocytes (p = 0.036). Immune cells are distributed unevenly in the tumours after TAE. The intrinsic induction state of the tumour after embolization may be insufficient to elicit a maximal response to PD-1/PD-L1 inhibitors.