Programmed Cell Death Ligand 1 Expression Levels Research Articles

Immunohistochemical factors of prognosis of immunotherapy for metastatic melanoma: А prospective and retrospective study

Introduction. Anti-PD-1 immunotherapy (IT) is becoming the standard treatment for patients with metastatic melanoma. However, immune checkpoint inhibitors are only effective in a fraction of patients, and studies examining biological markers and their correlation with clinical efficacy are insufficient to draw unambiguous conclusions. Aim. To improve the outcomes of the first-line therapy for disseminated melanoma based on identifying clinical and immunohistochemical predictors of IT efficacy. Materials and methods. Data from 130 patients who were treated with immune checkpoint inhibitors (nivolumab or prolgolimab) in the first-line therapy for disseminated melanoma between 2017 and 2024 were analyzed. Results. Improvement was observed in 24 patients (18.4%): complete response in 18 patients (13.8%), partial response in 6 (4.6%), and stabilization in 71 (54.6%) patients. Progression was reported in 31 (24%) patients. Death occurred in 4 (3%) cases during IT with prolgolimab due to disease progression. The two-year disease-free survival (DFS) during IT was 53% (95% confidence interval [CI] 42–67), p=0.63; the median 2-year overall survival was not reached. In the immunohistochemical study, 47 (63.5%) patients had a predominance of tumor infiltration with CD8 lymphocytes over CD4, regardless of the IT type: 2-year DFS 82% (95% CI 70–96) vs 13% (95% CI 2.7–64) in the absence of CD8 predominance over CD4, p=0.0001; the median DFS was not reached in patients with the predominance of CD8 lymphocytes tumor infiltration over CD4 compared to the other group – 7.6 months in the absence of this feature (95% CI 5.8–0), p=0.001. The peritumoral location of the immune lymphoid infiltrate was observed in all 74 (100%) patients, and the intratumoral location was less common (52 patients, 70%). In the presence of both periand intratumoral location of the immune infiltrate, the 2-year DFS was 83% (95% CI 70–98) compared to the group of patients in whom no intratumoral location was detected – 5.5% (95% CI 0.8–36), p0.0001. The expression of programmed cell death ligand 1 (PD-L1) level 10% was observed in 47 (63.5%) patients. With this level of PD-L1 expression, the one-year DFS was 91% (95% CI 83–100) compared to 29% (95% CI 15–57) with a lower level of PD-L1 expression, p0.0001; the median DFS is reached, and in the group 2, DFS was only 6.6 months. In the case of PD-L110%, the 2-year DFS was high at 78% (95% CI 63–100), p0.0001. Conclusion. Based on the study's results, it can be assumed that immunohistochemical characteristics such as a PD-L1 expression level 10%, the simultaneous presence of periand intratumoral lymphoid tumor infiltration, and the predominance of CD8 over CD4 can be considered predictors of IT efficacy with nivolumab and prolgolimab.

Programmed Cell Death Ligand 1 (PD-L1) Immunohistochemical Expression in Advanced Urothelial Bladder Carcinoma: An Updated Review with Clinical and Pathological Implications.

The management of advanced bladder carcinoma involves a multidisciplinary approach, but the prognosis remains poor for many patients. The immune system plays a crucial role in this disease, influencing both tumor development and response to treatment, and exploiting the immune system against the tumor can be a valuable strategy to destroy neoplastic cells. This is the biological principle underlying Bacillus Calmette-Guérin (BCG) use and, more recently, immune checkpoint inhibitors (ICIs), like PD-1 (programmed death-1)/PD-L1 (programmed death-ligand 1) inhibitors. In fact, one of the best studied immune checkpoints is represented by the PD-1/PD-L1 axis, which is a well-known immune escape system adopted by neoplastic bladder cells. PD-L1 expression has been associated with a higher pathologic stage and has shown prognostic value in bladder carcinoma. Interestingly, high-grade bladder cancers tend to express higher levels of PD-1 and PD-L1, suggesting a potential role of such an axis in mediating disease progression. Immunotherapy with PD-1 and PD-L1 inhibitors has therefore emerged as a valuable treatment option and has shown efficacy in advanced bladder cancer patients, with high PD-L1 expression levels associated with better treatment responses. Our review aims to provide a comprehensive overview of the role of PD-L1 in advanced bladder cancer, focusing on its implications for treatment decisions and the prediction of treatment response. Overall, our work aims to contribute to the understanding of PD-L1 as a predictive biomarker and highlight its role in shaping therapeutic approaches for advanced bladder cancer.

Synergistic upregulation of PD‑L1 in tumor cells and CD39 in tumor‑infiltrating CD8+ T cells leads to poor prognosis in patients with hepatocellular carcinoma.

The immune escape of tumor cells and functional status of tumor-infiltrating T cells may serve pivotal roles in the tumor immune microenvironment and progression of hepatocellular carcinoma (HCC). The present study enrolled 91 patients with HCC and examined programmed cell death ligand 1 (PD-L1) expression in tumor cells and CD39 expression in tumor-infiltrating CD8+ T cells in patient samples using multiplex immunofluorescence assays. The impact of PD-L1 and CD39 expression levels on the prognosis of patients with HCC was investigated utilizing Kaplan-Meier analyses. The individual upregulation of PD-L1 in tumor cells, as well as the individual upregulation of CD39 expression in tumor-infiltrating CD8+ T cells did not significantly affect the prognosis of patients with HCC. However, the simultaneous upregulation of both PD-L1 in tumor cells and CD39 in tumor-infiltrating CD8+ T cells was associated with reduced overall survival in patients with HCC. Therefore, the results of the present study suggested that the interplay between tumor cell immune escape and tumor-infiltrating immune cell functional status within the tumor immune microenvironment may have had a substantial impact on the prognosis of patients with HCC. Mechanistically, increased expression levels of PD-L1 in tumor cells may improve the immune escape capacity of tumors, whilst upregulation of CD39 in tumor-infiltrating T cells may be associated with T cell exhaustion. Therefore, the upregulation of PD-L1 expression in tumor cells, in conjunction with the exhaustion of tumor-infiltrating CD8+ T cells, could serve as a future potential prognostic indicator of patients with HCC.

PD-L1 expression in patients with non-small-cell lung cancer is associated with sex and genetic alterations: A retrospective study within the Caucasian population.

Programmed cell death-ligand 1 (PD-L1) expression is a well-established biomarker for predicting responses to immune checkpoint inhibitors and certain targeted therapies. As a result, treatment strategies for patients vary based on their PD-L1 expression status. Understanding the clinical features of patients with distinct PD-L1 levels is crucial for personalized treatment approaches. Demographic and clinicopathological characteristics of 227 patients (54% male, mean age 67 ± 9.9 years) newly diagnosed with non-small-cell lung cancer (NSCLC) between April 2020 and December 2022 were retrospectively compared among three groups based on the PD-L1 expression: PD-L1 Tumor Proportion Score (TPS) negative, 1-50%, and ≥50%. Logistic regression analysis was performed to evaluate predictors for high PD-L1 expression ≥50%. PD-L1 expression levels were distributed as follows: negative in 29% of patients, between 1% and 50% in 41%, and greater than 50% (high) in 29%. In comparison to negative PD-L1 expression, low and high PD-L1 expression was associated with female sex (32.9% vs. 52.7% vs. 50.7%, p = 0.031), with the absence of epidermal growth factor receptor (EGFR) mutations (83.6% vs. 91.1% vs. 98.1% p = 0.029), and with the absence of ERBB2 (HER2) tyrosine kinase mutations (90.9% vs. 100% vs. 98.1% p = 0.007), respectively. Age, smoking status, histological subtype, and disease stage showed no significant differences among the three patient groups. In the univariate logistic regression, EGFR mutation appeared to be the only predictor for PD-L1 expression, although it did not reach statistical significance (p = 0.06). Although sex and genomic alterations are associated with PD-L1 expression in patients with NSCLC, no clinical characteristics seem to predict PD-L1 expression significantly.

Effect of strong programmed cell death ligand-1 (PD-L1) expressions on clinical outcomes in advanced non-small cell lung cancer treated with third-generation epidermal growth factor receptor-tyrosine kinase inhibitors.

e20500 Background: Third-generation tyrosine kinase inhibitors (TKIs) are the standard treatment for advanced epidermal growth factor receptor (EGFR) mutation-positive lung adenocarcinoma. In first/second generation EGFR-TKIs, strong programmed death ligand 1 (PD-L1) expression contributes to primary resistance, significantly affecting patient prognosis. Despite this, the relationship between PD-L1 expression levels and third-generation TKIs remains unclear. Methods: This retrospective cohort study reviewed patients with advanced NSCLC who received third-generation EGFR-TKIs as first-line systemic therapy at the Shandong Cancer Hospital between March 2019 and June 2022. The EGFR status of the patients was assessed using amplification refractory mutation system fluorescence quantitative polymerase chain reaction, and the PD-L1 expression level was evaluated using Dako 22 C3 immunohistochemical staining. The Kaplan–Meier method was used for survival analysis. The log-rank test was used to compare differences in survival curves between the two groups. Results: Overall, 150 patients were included in this study. PD-L1 expression was negative (PD-L1 tumor proportion score < 1%) in 89 cases, weak (1–49%) in 42 cases, and strong (≥50%) in 19 cases. The median follow-up period for the entire cohort was 22.12 months (median progression-free survival [mPFS]: 24.33 months); the median overall survival was not reached. mPFS for patients with negative, weak, and strong PD-L1 expressions was 23.60, 26.12, and 16.60 months, respectively. The mPFS for strong PD-L1 expression was significantly shorter than that for with weak PD-L1 expression but was not associated with negativity, particularly in the 19DEL and 21L858R subgroups. PFS was significantly shorter in patients with strong PD-L1 expression in both subgroups (19DEL and 21L858R) than in those with weak PD-L1 expression. Conclusions: Strong PD-L1 expression in tumor cells influenced the clinical outcomes of patients with advanced NSCLC treated with third-generation EGFR-TKIs. Stronger PD-L1 expression in TKI-treated patients with advanced first-line EGFR-mutated NSCLC was associated with worse PFS.

The clinical application of circulating tumor cells (CTCs) for immunotherapy in advanced pancreatic cancer.

e14541 Background: Circulating tumor cell (CTCs) has the potential utility for screening, prognostic and predictive assessment, and offers the potential for personalized management. This trial aimed to evaluate the prognostic and predictive impact of programmed cell death ligand 1 (PD-L1) positive CTCs in patients with pancreatic ductal adenocarcinoma (PDAC). Methods: Twenty-three heavily treated advanced PDAC patients were randomized to receive camrelizumab combined with apatinib or capecitabine, or placebo plus capecitabine until disease progression or unacceptable toxicity, and peripheral blood CTCs samples were collected at baseline and after treatment. Forty-nine CTCs samples from 23 recruited advanced PDAC patients were detected by subtraction enrichment and immunostaining-FISH (SE-iFISH). PD-L1 expression level also was evaluated in tumor tissue samples by Immunohistochemistry (IHC). Investigator-assessed 6-month overall survival (OS) rate and 3-month progression-free survival (PFS) rate was evaluated. Results: The positive detection rate of CTCs in 23 PDAC patients was 95.7%. The cell sub-types of sizes of CTC analysis showed that 58.6% CTCs was the small CTCs (Diameter < 5μm). CTCs karyotypes analysis exhibited that triploid small CTCs were the main karyotype (41.2%) in small CTC, and pentaploid large CTCs was the major karyotype (74.7%) in large CTCs. PD-L1+ CTCs were detected in 43.5% of PDAC patients. Tissue PD-L1 positive detection rate was 50% (CPS > 1%) in available tissue samples(n=10). The presence of PD-L1+ CTCs cohort exhibited a significant increase in 6-month OS rate (80% versus 38.5%, P < 0.05) and 3-month PFS rate (70% versus 23.1%, P < 0.05) compared to PD-L1- CTCs cohort. Compared with the PD-L1- CTCs patients, the combination therapy camrelizumab markedly improved the 6-month OS rates (75% versus 50%) and 3-month PFS rate (62.5% versus 25%) in PD-L1+ CTC patients. Conclusions: PD-L1+ CTCs could be considered as a favorable prognostic marker in advanced PDAC. These results suggest that PD-L1+ CTCs might be used as a predictor of the efficacy of cancer immunotherapy in advanced PDAC, and provide a new monitoring method for the precise treatment of advanced PDAC. The expanding sample size test is now ongoing. Clinical trial information: ChiCTR1900024095 .

A phase 2/3 study of fianlimab, cemiplimab, plus chemotherapy versus cemiplimab plus chemotherapy in first-line treatment of advanced non-small cell lung cancer.

TPS8660 Background: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Anti–programmed cell death-1 (PD-1) therapies have improved outcomes in patients with NSCLC; however, most patients do not respond or only respond for a limited time. The combination of cemiplimab (anti–PD-1) and chemotherapy has been studied for the first-line treatment of advanced NSCLC (aNSCLC), regardless of programmed cell death-ligand 1 (PD-L1) status. While the standard of care continues to evolve for NSCLC, one approach to potentially improve outcomes is the combination of checkpoint inhibitors (IO) with chemotherapy. Fianlimab (anti–lymphocyte activation gene 3 [LAG-3]) and cemiplimab are both high-affinity, fully human IgG4 monoclonal antibody IO therapies that have shown promising clinical activity when combined in patients with aNSCLC in a Phase 1 study (NCT03005782). This ongoing study will further investigate the combination of fianlimab + cemiplimab + chemotherapy. Methods: This is a randomized, multicenter, Phase 2/3 study of fianlimab + cemiplimab + platinum-doublet chemotherapy (chemo) versus cemiplimab + chemo in patients with unresectable stage IIIB/IIIC or stage IV NSCLC irrespective of PD-L1 expression levels (NCT05800015). This study will be conducted globally at approximately 210 sites. Patient eligibility criteria: ≥18 years old; squamous or non-squamous histology with stage IIIB, IIIC, or IV disease; valid PD-L1 result; ≥1 radiographically measurable lesion by computed tomography/magnetic resonance imaging; Eastern Cooperative Oncology Group performance status ≤1; adequate organ and bone marrow function. The Phase 2 portion will be used to determine the fianlimab dose selected for the Phase 3 portion: patients will be randomized 1:1:1 to receive fianlimab high dose + cemiplimab 350 mg + chemo (Arm A), fianlimab low dose + cemiplimab 350 mg + chemo (Arm B), or cemiplimab 350 mg + chemo + placebo (Arm C), Q3W IV. In Phase 3, patients will be randomized 1:1 into one of two treatment arms (either Arm A or Arm B, and Arm C) based on findings from Phase 2. The primary endpoint of Phase 2 is objective response rate (ORR) per blinded independent central review. The primary endpoint of Phase 3 is overall survival. The secondary endpoints include efficacy (ORR, disease control rate, time to tumor response, duration of response, progression-free survival, and overall survival), safety and tolerability, immunogenicity (anti-drug antibodies and neutralizing antibodies against fianlimab or cemiplimab in serum), patient-reported outcomes, and pharmacokinetics. This study and a parallel study of fianlimab + cemiplimab in patients with aNSCLC with tumors expressing PD-L1 ≥50% (NCT05785767) are currently open for enrollment. Clinical trial information: NCT05800015 .

Distribution characteristics and prognosis of tumor-infiltrating lymphocytes in the brain metastases of small cell lung cancer: a retrospective cohort study.

The efficacy of immunotherapy for brain metastases from small cell lung cancer (SCLC) is relatively low, and the tumor microenvironment of SCLC brain metastases is still unknown. Therefore, we investigated the distribution of tumor-infiltrating lymphocytes (TILs) and the expression of programmed cell death-ligand 1 (PD-L1) in patients with brain metastases from SCLC to explore the tumor microenvironment of SCLC brain metastases. A retrospective analysis was performed on 12 surgical specimens of brain metastases from patients with SCLC treated in the Department of Neurosurgery of The First Affiliated Hospital of Anhui Medical University from June 2017 to June 2022. The inclusion criteria for this study were the following: (I) a pathologically confirmed diagnosis of SCLC brain metastases; (II) surgical resection of brain metastases; (III) age >18 years; (IV) and complete clinical data. Patient-related data were retrieved from the inpatient medical record system, telephone follow-up of patients date of death, and overall survival (OS). The immunofluorescence-based tissue microenvironment analysis panel (MAP) was utilized for the detection of TILs, including CD3, CD8, programmed cell death 1 (PD-1), and PD-L1, in formalin-fixed and paraffin-embedded archival specimens of brain metastases. The expression levels of PD-L1 in tumor cells were detected by immunohistochemistry. The correlation between the OS and the above-mentioned markers was analyzed in the 12 patients. Twelve patients were included in the study. The patients' ages ranged from 51-78 years with a median of 68 years, with 1 female and 11 males. Among 12 patients with SCLC brain metastases: positive rates of CD3+ TILs in the tumor parenchyma vs. tumor stroma were 0.60%±0.94% vs. 1.76%±2.72% (P=0.01), respectively; positive rates of CD8+ TILs in the tumor parenchyma vs. tumor stroma were 0.80%±0.78% vs. 2.46%±3.72% (P=0.02), respectively. There was no co-expression of CD8+ and PD-1+ TILs in the tumor parenchyma of 11 cases, and the infiltration density of coexpressed CD3+ and PD-1+ TILs was more than 10/mm2 in only 1 case. There was no coexpression of CD3+ and PD-1+ TIL in the stroma of 10 cases, and the infiltration density of CD8+ and PD-1+ TILs was more than 10/mm2 in 2 cases. Immunohistochemistry was used to detect the expression of PD-L1 in 12 cases of SCLC metastatic lesions, and 3 cases (25%) were positive. Survival analysis showed that patients with positive intraepithelial CD3+ TILs had significantly longer OS [hazard ratio 3.383, 95% confidence interval (CI): 0.959-11.940; P=0.04]. Our study further demonstrated the immune microenvironment of SCLC brain metastases. The distribution of TILs in SCLC brain metastases is low and mainly distributed in the stroma, with the expression of PD-L1 in these tumor tissues being low. Further exploration of the immune microenvironment of SCLC brain metastases is of great significance for potential treatment.

Reducing PD-L1 Expression by Degraders and Downregulators as a Novel Strategy to Target the PD-1/PD-L1 Pathway.

Targeting the programmed cell death protein-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) pathway has evolved into one of the most promising strategies for tumor immunotherapy. Thus far, multiple monoclonal antibody drugs have been approved for treating a variety of tumors, while the development of small-molecule PD-1/PD-L1 inhibitors has lagged far behind, with only a few small-molecule inhibitors entering clinical trials. In addition to antibody drugs and small-molecule inhibitors, reducing the expression levels of PD-L1 has attracted extensive research interest as another promising strategy to target the PD-1/PD-L1 pathway. Herein, we analyze the structures and mechanisms of molecules that reduce PD-L1 expression and classify them as degraders and downregulators according to whether they directly bind to PD-L1. Moreover, we discuss the potential prospects for developing PD-L1-targeting drugs based on these molecules. It is hoped that this perspective will provide profound insights into the discovery of potent antitumor immunity drugs.

Camptothecin enhances the anti-tumor effect of low-dose apatinib combined with PD-1 inhibitor on hepatocellular carcinoma

Apatinib has been shown to apply to a variety of solid tumors, including advanced hepatocellular carcinoma. Preclinical and preliminary clinical results confirmed the synergistic antitumor effects of apatinib in combination with anti-programmed death-1 (PD-1) inhibitors. In this study, we investigated camptothecin (CPT) enhances the anti-tumor effect of low-dose apatinib combined with PD-1 inhibitor on hepatocellular carcinoma. CPT combined with a PD-1 inhibitor enhances the anti-tumor effects of low-dose apatinib in hepatocellular carcinoma which was evaluated in making use of the H22 mouse model (n = 32), which was divided into four groups. Immunohistochemical staining and western blotting were used to detect nuclear factor erythroid 2-related factor 2 (Nrf2) as well as sequestosome 1 (p62), vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor 2 (VEGFR2), PD-1, and programmed cell death ligand 1 (PD-L1). The results showed that the average size of the tumor of the combination group (Group D) was significantly less than that of the apatinib + PD-1 inhibitor group (Group C). The expression levels of Nrf2, p62, VEGFA, VEGFR2, PD-1, and PD-L1 in the apatinib + PD-1 inhibitor group(Group C) were lower than those in the control group (Group A) (P < 0.05). The expression levels of these genes in the apatinib + PD-1 inhibitor group (Group C) were significantly lower in the combination group (Group D) (P < 0.05). There was no obvious difference in body weight and liver and kidney functions between the four groups of mice. In conclusion, CPT improves the anti-tumor effect of low-dose apatinib combined with PD-1 inhibitor on hepatocellular carcinoma

1,8-Cineol Attenuates Checkpoint Molecule PDL-1 and Adhesion Molecule CX3CR1 in Circulating Monocytes in Otitis Media Patients.

Peripheral blood monocytes can be subdivided into different subsets based on the CD14/CD16 surface characteristics. Monocytes are a major source of cytokine secretion of pro-inflammatory immune responses, whereas CD16+ monocyte subsets can also contribute to persistent inflammation in the context of chronic diseases. However, the regulation and cellular characteristics of circulating monocyte subsets in patients with chronic otitis media (COM), one of the largest public health burdens, remains largely unknown. In this study, we analyzed individual distributions of circulating monocyte subsets and associated protein expression levels of adhesion protein and chemokine receptors CD11a (integrin-α L; LFA-1), CD11b (integrin-α M; Mac-1), and CD11c (integrin-α X), CX3CR1 (CX3CL1 receptor), as well as checkpoint molecule PD-L1 (programmed cell death ligand-1), in a gender-balanced cohort of 14 patients with chronic otitis media using flow cytometry, especially in view of the therapeutic impact of the natural plant-derived monoterpene oxide 1,8-Cineol. Furthermore, using the human monocyte cell line THP-1 as a model, we investigated the influence of anti-inflammatory 1,8-Cineol on monocytic cytokine secretion patterns using human cytokine arrays and ELISA measurements. The data revealed significantly elevated expression levels of all analyzed adhesion molecules in certain monocyte subsets in COM patients; CX3CR1 was especially significantly down-regulated in response to 1,8-Cineol administration. Moreover, the data revealed significantly increased monocytic PD-L1 expression levels in circulating classical and intermediate monocyte subsets from COM patients compared to healthy donors, but also a significant decrease in PD-L1 in intermediate monocytes upon 1,8-Cineol therapy compared to the pre-treatment situation. Furthermore, the increased secretion of cytokine CXCL10 by THP-1 monocytes in response to LPS was found to be strongly attenuated by 1,8-Cineol. Plasma levels of CXCL10 were also significantly increased in COM patients, but no significant differences between the pre and post 1,8-Cineol situation were observed. The present study revealed new insights into the bioactive anti-inflammatory effects of 1,8-Cineol in terms of monocyte adhesion and immune regulation. Our data suggest the potential role of cytokine CXCL10 in COM development and maintenance, which is also involved in the activity of its concomitant disease, rheumatoid arthritis.

Association of Androgen Receptor and PD-L1 Expression in Upper Urinary Tract Urothelial Carcinoma.

The response to immune checkpoint inhibitors (ICIs) or enfortumab vedotin is limited in patients with upper urinary tract urothelial carcinoma (UTUC), and the development of new targeted therapy for UTUC is eagerly needed. Several biomarkers, including programmed cell death-ligand 1 (PD-L1), have already been reported as predictors of response to ICIs therapy for UTUC. Recently, several studies have shown that steroid hormone receptors, including the androgen receptor (AR), are associated with progression of urothelial carcinoma. We prepared tissue microarrays (TMA) from paraffin blocks of UTUC specimens in 99 non-metastatic UTUC patients who underwent radical nephroureterectomy. With these TMA sections, we performed immunohistochemical staining for PD-L1 and AR and examined PD-L1 and AR expression levels in tumor cells. In addition, we analyzed the correlation between these markers and clinical prognosis in UTUC cases. PD-L1 was positive in 24 (24%) of the 99 samples, whereas AR was positive in 20 (20%) patients. AR-negative samples had significantly higher PD-L1 expression level than that the AR-positive samples (mean value 4.70% versus 2.55%, p=0.0324). Among AR-positive cases, patients with absence of PD-L1 expression had significantly lower cancer-specific survival (CSS) than that in PD-L1 expression-positive cases (p=0.049), although PD-L1 expression had no significant impact on CSS in AR-negative cases (p=0.920). Our findings suggest that AR is the promising target for UTUC treatment, especially in PD-L1-negative cases.

The prognostic significance of PD-1 and its ligands in non-small cell lung cancer.

In this study, we aimed to investigate the prognostic value of programmed cell death protein 1 (PD-1), programmed cell death ligand 1 (PD-L1), and programmed cell death ligand 2 (PD-L2) expressions on immune and cancer cells in terms of survival in patients with lung adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Between January 2000 and December 2012, a total of 191 patients (172 males, 19 females; mean age: 60.3±8.4 years; range, 38 to 78 years) who were diagnosed with non-small cell lung cancer and underwent anatomic resection and mediastinal lymph node dissection were retrospectively analyzed. The patients were evaluated in three groups including lung squamous cell carcinoma (n=61), adenocarcinoma (n=66), and large-cell carcinoma (n=64). The survival rates of all three groups were compared in terms of immunohistochemical expression levels of PD-1, PD-L1, and PD-L2. The mean follow-up was 71.8±47.9 months. In all histological subtypes, PD-1 expressions on tumor and immune cells were observed in 33% (61/191) and in 53.1% (102/191) of the patients, respectively. Higher expression levels of PD-L1 and PD-L2 at any intensity on tumor and immune cells were defined only in lung adenocarcinomas, and PD-L1 and PD-L2 values were detected in 36.4% (22/64) of these patients. The PD-L1 expressions on tumor and immune cells were observed in 41.7% (10/24) and 25% (6/24) of the patients, respectively. The PD-L2 expressions on tumor and immune cells were detected in 16.7% (4/24) and 8.4% (2/24) of the patients, respectively. Univariate and multivariate analyses revealed that PD-1 expression in tumor cells was an independent prognostic factor in all histological subtypes. Our study results suggest that PD-1 expression is a poor prognostic factor for overall survival in patients with completely resected adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.

Molecular and immunological characteristics of patients with CMTM6 low expression colorectal cancer.

CKLF-like MARVEL transmembrane domain-containing 6 (CMTM6), a regulator of programmed cell death ligand 1 (PD-L1), has attracted extensive attention due to its role in tumors. However, research on the expression of CMTM6 in colorectal cancer (CRC) and its relationship with PD-L1 expression and immune cell infiltration is limited. We used The Cancer Genome Atlas database to mine and analyze data from patients with CRC using bioinformatics methods. We investigated the expression of CMTM6 in CRC and its relationship with PD-L1 expression and immune cell infiltration. Immunohistochemistry and PCR were performed to detect CMTM6 and PD-L1 expression in CRC tissues. Differential gene expression analysis was performed using the edgeR package in R and immune cell infiltration analysis was performed using the ssGSEA algorithm. Additionally, GO and KEGG enrichment analyses were conducted to identify the biological processes and pathways associated with low CMTM6 expression. Our study found that CMTM6 expression was significantly upregulated in CRC tissues compared to that in adjacent normal tissues. Patients with high CMTM6 expression exhibited significantly increased levels of PD-L1 expression and higher levels of tumor-infiltrating immune cells compared to patients with low CMTM6 expression. GO and KEGG analyses suggested that CMTM6 may be involved in multiple immune regulatory pathways in CRC.

Development of novel peptide-based radiotracers for detecting PD-L1 expression and guiding cancer immunotherapy.

Due to tumor heterogeneity, immunohistochemistry (IHC) showed poor accuracy in detecting the expression of programmed cell death ligand-1 (PD-L1) in patients. Positron emission tomography (PET) imaging is considered as a non-invasive technique to detect PD-L1 expression at the molecular level visually, real-timely and quantitatively. This study aimed to develop novel peptide-based radiotracers [68Ga]/[18F]AlF-NOTA-IMB for accurately detecting the PD-L1 expression and guiding the cancer immunotherapy. NOTA-IMB was prepared by connecting 2,2'-(7-(2-((2,5-dioxopyrrolidin-1-yl)oxy)- 2-oxoethyl)-1,4,7-triazonane-1,4-diyl) diacetic acid (NOTA-NHS) with PD-L1-targeted peptide IMB, and further radiolabeled with 68Ga or 18F-AlF. In vitro binding assay was conducted to confirm the ability of [68Ga]/[18F]AlF-NOTA-IMB to detect the expression of PD-L1. In vivo PET imaging of [68Ga]NOTA-IMB and [18F]AlF-NOTA-IMB in different tumor-bearing mice was performed, and dynamic changes of PD-L1 expression level induced by immunotherapy were monitored. Radioautography, western blotting, immunofluorescence staining and biodistribution analysis were carried out to further evaluate the specificity of radiotracers and efficacy of PD-L1 antibody immunotherapy. [68Ga]NOTA-IMB and [18F]AlF-NOTA-IMB were both successfully prepared with high radiochemical yield (> 95% and > 60%, n = 5) and radiochemical purity (> 95% and > 98%, n = 5). Both tracers showed high affinity to human and murine PD-L1 with the dissociation constant (Kd) of 1.00 ± 0.16/1.09 ± 0.21nM (A375-hPD-L1, n = 3) and 1.56 ± 0.58/1.21 ± 0.39nM (MC38, n = 3), respectively. In vitro cell uptake assay revealed that both tracers can specifically bind to PD-L1 positive cancer cells A375-hPD-L1 and MC38 (5.45 ± 0.33/3.65 ± 0.15%AD and 5.87 ± 0.27/2.78 ± 0.08%AD at 120min, n = 3). In vivo PET imaging and biodistribution analysis showed that the tracer [68Ga]NOTA-IMB and [18F]AlF-NOTA-IMB had high accumulation in A375-hPD-L1 and MC38 tumors, but low uptake in A375 tumor. Treatment of Atezolizumab induced dynamic changes of PD-L1 expression in MC38 tumor-bearing mice, and the tumor uptake of [68Ga]NOTA-IMB decreased from 3.30 ± 0.29%ID/mL to 1.58 ± 0.29%ID/mL (n = 3, P = 0.026) after five treatments. Similarly, the tumor uptake of [18F]AlF-NOTA-IMB decreased from 3.27 ± 0.63%ID/mL to 0.89 ± 0.18%ID/mL (n = 3, P = 0.0004) after five treatments. However, no significant difference was observed in the tumor uptake before and after PBS treatment. Biodistribution, radioautography, western blotting and immunofluorescence staining analysis further demonstrated that the expression level of PD-L1 in tumor-bearing mice treated with Atezolizumab significantly reduced about 3 times and correlated well with the PET imaging results. [68Ga]NOTA-IMB and [18F]AlF-NOTA-IMB were successfully prepared for PET imaging the PD-L1 expression noninvasively and quantitatively. Dynamic changes of PD-L1 expression caused by immunotherapy can be sensitively detected by both tracers. Hence, the peptide-based radiotracers [68Ga]NOTA-IMB and [18F]AlF-NOTA-IMB can be applied for accurately detecting the PD-L1 expression in different tumors and monitoring the efficacy of immunotherapy.

The prognostic value of expressions of STAT3, PD-L1, and PD-L2 in Ta/T1 urothelial carcinoma before and after BCG treatment

IntroductionNonmuscle invasive bladder cancers (NMIBC) are common tumors diagnosed in older individuals and men (median age: 69 years). Immunotherapy is a treatment option in cases resistant to Bacillus-Calmette-Guerin (BCG) therapy. We aimed to evaluate the prognostic role of programmed-cell-death ligand (PD-L)-1 (PD-L1), PD-L2, and signal transducer and activator of transcription 3 (STAT3) expressions, which are closely related to immune mechanisms, in the response to BCG treatment of NMIBC. MethodsThe data of patients at the Ta and T1 stages of the cancer without muscularis propria invasion, who were treated with intravesical BCG therapy between 2017 and 2022 were retrospectively analyzed. Immunohistochemical staining for PD-L1, PD-L2, and STAT3 was performed on transurethral resection materials. ResultsThe mean age of 59 patients was 66.5 ±7.7 and 83.9% were male. The percentage of patients with complete response to BCG treatment was 66.1% and that of BCG refractory patients was 33.9%. Demographic and clinical data did not differ significantly according to BCG treatment response (P> 0.05). The proportion of patients with tumor-infiltrating lymphocytes (TILs) ≥20% were 9.7% among those with Ta-stage tumors and 46.4% among those with T1-stage tumors (P = 0.0014). The percentages of tumor cell scoring (TCS), immune cell scoring (ICS), combined scoring (CS), and expression levels of PD-L1, PD-L2, and H-score of STAT3 did not differ significantly according to tumor stage and treatment response (P > 0.05). However, the median ICS and CS for PD-L1 and median H-score for STAT3 were significantly higher among patients in T1 stage compared to those in Ta stage (P = 0.0487, 0.0462, 0.0112, respectively). Among BCG refractory patients, median STAT3 of patients in T1 stage was significantly higher than those at stage Ta (P = 0.0356) and the rate of TILs was ≥20% in only 3 patients in T1 stage (P = 0.031). Among all patients, significant positive correlation was found between TCS for PD-L1 and H-score for STAT3 (P = 0.0302); and between ICS for PD-L1 and TCS for PD-L2 (P = 0.0053) and TILs ratio (P < 0.0001). Among BCG-refractory cases, pretreatment and post-treatment TCS for PD-L2 and H-scores for STAT3 were significantly correlated (P = 0.0361 and 0.0021, respectively). ConclusionsThe success of BCG treatment in NMIBC was not related to PD-L1, PD-L2, and STAT3 expression status, but PD-L1 expression was correlated with both PD-L2 and STAT3 as well as TILs rate, but this correlation was lost after BCG treatment.

Radiomics for the non-invasive prediction of PD-L1 expression in patients with brain metastases secondary to non-small cell lung cancer

BackgroundThe expression level of the programmed cell death ligand 1 (PD-L1) appears to be a predictor for response to immunotherapy using checkpoint inhibitors in patients with non-small cell lung cancer (NSCLC). As differences in terms of PD-L1 expression levels in the extracranial primary tumor and the brain metastases may occur, a reliable method for the non-invasive assessment of the intracranial PD-L1 expression is, therefore of clinical value. Here, we evaluated the potential of radiomics for a non-invasive prediction of PD-L1 expression in patients with brain metastases secondary to NSCLC.Patients and methodsFifty-three NSCLC patients with brain metastases from two academic neuro-oncological centers (group 1, n = 36 patients; group 2, n = 17 patients) underwent tumor resection with a subsequent immunohistochemical evaluation of the PD-L1 expression. Brain metastases were manually segmented on preoperative T1-weighted contrast-enhanced MRI. Group 1 was used for model training and validation, group 2 for model testing. After image pre-processing and radiomics feature extraction, a test-retest analysis was performed to identify robust features prior to feature selection. The radiomics model was trained and validated using random stratified cross-validation. Finally, the best-performing radiomics model was applied to the test data. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analyses.ResultsAn intracranial PD-L1 expression (i.e., staining of at least 1% or more of tumor cells) was present in 18 of 36 patients (50%) in group 1, and 7 of 17 patients (41%) in group 2. Univariate analysis identified the contrast-enhancing tumor volume as a significant predictor for PD-L1 expression (area under the ROC curve (AUC), 0.77). A random forest classifier using a four-parameter radiomics signature, including tumor volume, yielded an AUC of 0.83 ± 0.18 in the training data (group 1), and an AUC of 0.84 in the external test data (group 2).ConclusionThe developed radiomics classifiers allows for a non-invasive assessment of the intracranial PD-L1 expression in patients with brain metastases secondary to NSCLC with high accuracy.

Expression of tumor-associated macrophages and PD-L1 in patients with hepatocellular carcinoma and construction of a prognostic model.

Hepatocellular carcinoma (HCC) is an inflammation-associated tumor involved in immune tolerance and evasion in the immune microenvironment. Immunotherapy can enhance the immune response of the body, break immune tolerance, and then recognize and kill tumor cells. The polarization homeostasis of M1 and M2 macrophages in tumor microenvironment (TME) is involved in the occurrence and development of tumors and has been considered a hot topic in tumor research. Programmed cell death ligand 1 (PD-L1) plays an important role in the polarity of TAM and affects the prognosis of HCC patients as a target of immunotherapy. To this end, efforts were hereby made to further explore the application value of PD-L1, M1 macrophages (CD86), and M2 macrophages (CD206) in the prognosis assessment of HCC, their correlation with immune cell infiltration in HCC tissues, and their bioenrichment function. The gene expression omnibus (GEO) and the Cancer Genome Atlas (TCGA) database were used to analyze the expression of PD-L1, CD86, and CD206 in different tumor tissues. The correlation between the expression of PD-L1, CD86, and CD206 and the infiltration of immune cells was analyzed using the Tumor Immune Estimation Resource (TIMER). The tissue specimens and clinicopathological data of hepatocellular carcinoma patients having undergone surgical treatment in our hospital were collected. Immunohistochemistry was used to verify the expression of PD-L1, CD86, and CD206, and analyze the relationship with clinicopathological features and prognosis of patients. Besides, nomogram was constructed to predict the overall survival (OS) of patients at 3 and 5years. Finally, the protein-protein interaction network information was analyzed using STRING database, and GO analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis were performed to study the biological functions of PD-L1, CD86, and CD206. Bioinformatics analysis found that PD-L1, CD86, and CD206 were underexpressed in various tumor tissues including liver cancer, while the present immunohistochemical detection found that PD-L1, CD86, and CD206 were overexpressed in liver cancer tissues. Expressions of PD-L1, CD86, and CD206 were positively correlated with the infiltration level of immune cells in liver cancer, while the expression of PD-L1 was positively correlated with the degree of tumor differentiation. Meanwhile, the expression level of CD206 was positively correlated with gender and preoperative hepatitis, and patients with high expression of PD-L1 or low expression of CD86 had poor prognosis. AJCC stage, preoperative hepatitis, and the expression levels of PD-L1 and CD86 in cancer tissues were independent risk factors affecting survival of patients after radical hepatoma surgery. KEGG pathway enrichment analysis showed that PD-L1 was significantly enriched in T cell aggregation and lymphocyte aggregation, and might be involved in the formation of T cell antigen receptor CD3 complex and cell membrane. Besides, CD86 was significantly enriched in positive regulation of cell adhesion, regulation of mononuclear cell proliferation, regulation of leukocyte proliferation, and transduction of T cell receptor signaling pathway, while CD206 was significantly enriched in type 2 immune response, cellular response to LPS, cellular response to LPS, and involvement in cellular response to LPS. In conclusion, these results suggest that PD-L1, CD86, and CD206 may be involved not only in the occurrence and development of HCC, but also in immune regulation, indicating the potential role of PD-L1 and CD86 as potential biomarkers and new therapeutic targets for prognosis assessment of liver cancer.

Relationship between PD-L1 expression and molecular aberrances in lung adenocarcinoma with solid components.

Previous studies have evaluated the expression of programmed cell death ligand 1 (PD-L1) in terms of genetic mutation in lung adenocarcinoma (LUAD). However, there are no corresponding large-sample studies in Chinese patients with LUAD with solid components (LUAD-SC). Furthermore, it remains unknown whether the relationship that exists between PD-L1 expression levels and clinicopathological and molecular profiles in small biopsy specimens is consistent with that in surgically-resected specimens. The present study explored the clinicopathological features and genetic correlation of PD-L1 expression in LUAD-SC. We collected 1,186 LUAD-SC specimens from Fudan University, Zhongshan Hospital. The tumors were divided into PD-L1 negative, low, and high groups according to the tumor proportion score (TPS)-assessed expression of PD-L1. The mutational information of all specimens was assessed. Each group's clinicopathological features were also assessed. The relationship between PD-L1 expression levels and clinicopathological features, the overlap with driver genes and the prognostic value were analyzed. In 1,090 resected specimens, a high PD-L1 expression level was more prevalent in the group with predominant SCs, which was remarkably correlated with lymphovascular invasion and a more advanced clinical stage. In addition, the PD-L1 expression level was significantly related to EGFR, KRAS, and BRAF mutations and ROS1 fusions. Meanwhile, in 96 biopsy specimens, the solid-dominant type and EGFR showed a significant difference in PD-L1 expression. Furthermore, compared with their resected counterparts, the biopsy specimens were significantly associated with solid predominant, advanced tumor-node-metastasis (TNM) stage, and high PD-L1 expression. Finally, high PD-L1 expression can be considered a poor prognostic factor for overall survival (OS). LUAD-SC with high PD-L1 expression levels is linked to unique clinicopathologic characteristics as well as driver mutations. It is important to evaluate the percentage of solid components in both punctured and excised specimens, which may help identify cases of high PD-L1 expression.

Programmed Cell Death Ligand 1 Expression on Immune Cells and Survival in Patients With Nonmetastatic Head and Neck Cancer

The failure or success of radical treatment in patients with head and neck squamous cell carcinoma (HNSCC) is associated with many known and unknown factors; hence, there is a search for further prognostic markers to help optimize therapeutic strategy and improve treatment outcomes. To assess the association of programmed cell death ligand 1 (PD-L1) expression on immune or tumor cells, including its composite expression on both cell types, with overall survival (OS) or specific survival. MEDLINE, Embase, PQSciTech, and HCAPlus databases were systematically searched for cohort studies focused on the prognostic role of PD-L1 expression in patients with HNSCC in curative stages of the disease. Search results generated publications from January 1, 2010, to January 6, 2023. Of 3825 publications identified, a total of 17 cohort studies in the English language met inclusion criteria of this systematic review and meta-analysis. Eligible studies reported adjusted hazard ratios (aHRs) with 95% CIs for the association of PD-L1 expression levels with OS and arbitrary specific survival. Data from studies were extracted independently by 2 researchers strictly adhering to the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guidelines and recommendations. The risk of bias was assessed using the Quality in Prognosis Studies tool and Newcastle-Ottawa Scale. Pooled effect estimates were obtained using a random-effect or fixed-effect model based on homogeneity of studies. The primary outcome was to investigate whether there was an association between PD-L1 expression on immune or tumor cells and OS. In 17 cohort studies of the association of PD-L1 expression with survival in 3190 patients with HNSCC, high PD-L1 expression on immune cells was associated with a favorable OS (pooled aHR, 0.39; 95% CI, 0.25-0.59). There was no association between composite PD-L1 expression on immune and tumor cells and OS (pooled aHR, 0.79; 95% CI, 0.55-1.14) or between PD-L1 expressed only on tumor cells and OS (pooled aHR, 1.22; 95% CI, 0.87-1.70). A high level of PD-L1 expression on immune cells was associated with favorable specific survival (pooled aHR, 0.52; 95% CI, 0.38-0.72). There were no interactions between tumor location or type of primary treatment (ie, surgery vs radiotherapy or radiochemotherapy) and the association between PD-L1 expression and OS. This study's findings suggest that PD-L1 expression on immune cells may serve as a new prognostic biomarker in patients with HNSCC. However, future studies may be warranted to verify this potential role given the limited number of studies on this topic conducted and published to date.