Increased Programmed Cell Death Ligand 1 Expression Research Articles

Patterns and prognostic values of programmed cell death-ligand 1 expression and CD8 + T-cell infiltration in small cell carcinoma of the esophagus: a retrospective analysis of 34 years of National Cancer Center data in China.

Small cell carcinoma of the esophagus (SCCE) is an extremely rare and highly aggressive neuroendocrine malignancy with a strikingly poor prognosis. Given the great clinical successes of checkpoint immunotherapies, we explored the expression profile and clinical significance of programmed cell death-ligand 1 (PD-L1) and CD8 + T cell in SCCE for the first time. Tumor-infiltrating immune cells (TIICs) and tumor cells in postoperative, whole tumor sections from 147 SCCE patients were stained for PD-LI expression. We also evaluated each patient's Combined Positive Score (CPS). Multiplex immunofluorescence staining (CD3, CD20, CD68, and PD-L1) was introduced to clarify the location of PD-L1. CD8 density was analyzed by digital imaging and analysis of entire slides. Clinical outcomes were tested for correlations with both PD-L1 expression and CD8 density. No patients had PD-L1 expressed in their tumor cells. PD-L1 + expression in TIICs was detected in 65 patients (44.2%) and 42 (28.6%) exhibited CPS positivity. Multiplex immunofluorescence staining demonstrated that most of the PD-L1 was expressed on the CD68 + monocytes/macrophages. PD-L1 expression in the TIICs and CPS was found to be correlated with paraffin block age, tumor length, macroscopic type, T stage, and increased overall survival (OS). Expression of PD-L1 in TIICs showed significantly prolonged relapse-free survival (RFS). Increasing CD8 densities were associated with increased PD-L1 expression ( Ptrend <0.0001). Multivariate regression confirmed that PD-L1 in TIICs and CD8 states were independent predictors of OS, and CD8 status were found to be independently predictive of RFS. A stratification based on PD-L1 and CD8 status was also significantly associated with both OS and RFS. Expression of PD-L1 was only detected in TIICs from approximately half of the patients with SCCEs. In SCCEs, PD-L1 and CD8 status are novel prognostic biomarkers and may inform the implementation of risk-related therapeutic strategies. SCCEs with higher CD8 infiltration also had higher expression of PD-L1, suggesting the development of resistance against adaptive immunity. These findings support the assertion that PD-L1/programmed cell death 1 inhibitors should be investigated in this rare malignancy.

Redetermination of PD-L1 expression after chemio-radiation in locally advanced PDL1 negative NSCLC patients: retrospective multicentric analysis.

Chemoradiation therapy (CRT) is the treatment of choice for locally advanced non-small cell lung cancer (LA-NSCLC). Several clinical trials that combine programmed cell death 1 (PD1) axis inhibitors with radiotherapy are in development for patients with LA-NSCLC. However, the effect of CRT on tumor cells programmed cell death ligand-1 (PD-L1) expression is unknown. In this multicentric retrospective study, we analyzed paired NSCLC specimens that had been obtained pre- and post-CRT. PD-L1 expression on tumor cells was studied by immunohistochemistry. The purpose of this study was to evaluate the feasibility, risk of complications, and clinical relevance of performing re-biopsy after CRT in patients with PD-L1 negative LA-NSCLC. Overall, 31 patients from 6 centers with PD-L1 negative LA-NSCLC were analyzed. The percentage of tumor cells with PD-L1 expression significantly increased between pre- and post-CRT specimens in 14 patients (45%). Nine patients had unchanged PD-L1 expression after CRT, in five patients the rebiopsy material was insufficient for PD-L1 analysis and in two patients no tumor cells at rebiopsy were found. The post-rebiopsy complication rate was very low (6%). All patients with positive PD-L1 re-biopsy received Durvalumab maintenance after CRT, except one patient who had a long hospitalization for tuberculosis reactivation. Median PFS of patients with unchanged or increased PD-L1 expression was 10 and 16.9 months, respectively. CRT administration can induce PD-L1 expression in a considerable fraction of PD-L1 negative patients at baseline, allowing them receiving the maintenance Durvalumab in Europe. Hence, after a definitive CRT, PD-L1 redetermination should be considered in patients with LA-NSCLC PD-L1 negative, to have a better selection of maintenance Durvalumab candidates.

IL-17A promotes tumorigenesis and upregulates PD-L1 expression in non-small cell lung cancer

BackgroundThe tumor microenvironment plays a key role in non-small cell lung cancer (NSCLC) development and also influences the effective response to immunotherapy. The pro-inflammatory factor interleukin-17A mediates important immune responses in the tumor microenvironment. In this study, the potential role and mechanisms of IL-17A in NSCLC were investigated.MethodsWe detected IL-17A by immunohistochemistry (IHC) in 39 NSCLC patients. Its expression was correlated with the programmed cell death-ligand1 (PD-L1). IL-17A knockdown and overexpression in A549 and SPC-A-1 cell models were constructed. The function of IL-17A was examined in vitro by wound healing, migration, invasion, plate colony formation and T cell killing assay. Western blot analysis, immunofluorescence assay and IHC were performed to investigate the regulation effects of IL-17A on autophagy in A549 and SPC-A-1. The effect of IL-17A on ROS/Nrf2/p62 signaling pathway was detected. Subcutaneous tumor models were established to examine the tumor-promoting effect of IL-17A in vivo and its effect on immunotherapy.ResultsWe found a prevalent expression of IL-17A in NSCLC tumor tissues and it was positively correlated with PD-L1 expression (r = 0.6121, p < 0.0001). In vitro, IL-17A promotes lung cancer cell migration, invasion and colony formation ability. Moreover, IL-17A upregulated N-cadherin, Twist, and Snail, and downregulated E-cadherin in NSCLC cells. IL-17A enhanced cell survival in the T cell killing assay. Mechanistically, IL-17A induced ROS production and increased Nrf2 and p62 expression, thereby inhibiting autophagy and reducing PD-L1 degradation. In vivo experiments, anti-IL-17A monoclonal antibody alone slowed the growth of subcutaneous tumors in mice. When combined with anti-PD-L1 monoclonal antibody, tumor tissue expression of PD-L1 was reduced and the therapeutic effect was diminished.ConclusionWe found that IL-17A promoted NSCLC progression and inhibited autophagy through the ROS/Nrf2/p62 pathway leading to increased PD-L1 expression in cancer cells. Modulation of IL-17A may affect the therapeutic efficacy of immunotherapy.

The predictive implication of programmed cell death ligand 1 expression in extranodal natural killer/T-Cell lymphoma and its correlation with clinicopathological features: a systematic review and meta-analysis.

Although programmed cell death ligand 1 (PD-L1) expression and function in hematologic malignancies have aroused extensive attention, its prognostic value for extranodal natural killer/T-cell lymphoma (ENKTL) is still unknown. Therefore, we conducted this meta-analysis to explore the predictive value of neoplastic PD-L1 expression for ENKTL. The PubMed, Embase, Web of Science, and CNKI databases were searched to identify eligible observational studies reporting PD-L1 expression and survival outcomes of ENKTL patients. The search was conducted in accordance with the Meta-analyses Of Observative Studies in Epidemiology (MOOSE) guidelines. The pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were adopted to analyze survival outcomes, and the odds ratios (ORs) and 95% CIs were adopted for clinicopathological parameters. Review Manager 5.3 and STATA 17.0 were used for statistical analysis. Potential publication bias was evaluated by funnel plot and Egger's test. A total of 433 patients with ENKTL were included across seven studies. The pooled results showed no significant relationship between neoplastic PD-L1 expression and overall survival (OS) (HR =1.35, 95% CI: 0.49-3.75, P=0.559). We also performed subgroup analyses. However, increased PD-L1 expression was associated with a low international prognostic index (IPI) score of 0-1 (OR =2.46; 95% CI: 1.11-5.45, P=0.03), good performance status (OR =1.97; 95% CI: 1.11-3.51, P=0.02), and a good treatment effect (OR =2.61; 95% CI: 1.01-6.70, P=0.05). PD-L1-positive expression in patients with ENKTL was correlated with favorable clinical features. Thus, PD-L1-positive expression appears to be a potential predictor of treatment benefits. Additional large-scale, high-quality studies are needed to further explore its predictive value.

Study on the Biological Function of Abemecilib in Inhibiting the Proliferation, Invasion and Migration of Small Cell Lung Cancer with High c-Myc Expression

Small cell lung cancer (SCLC) with high c-Myc expression is prone to relapse and metastasis, leading to extremely low survival rate. Cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor Abemaciclib plays a key role in the treatment of tumors, but the effects and mechanisms on SCLC remain unclear. This study was to analyze the effect and molecular mechanism of Abemaciclib in inhibiting proliferation, migration and invasion of SCLC with high c-Myc expression, with a view to expanding a new direction for reducing the recurrence and metastasis. Proteins interacting with CDK4/6 were predicted using the STRING database. The expressions of CDK4/6 and c-Myc in 31 cases of SCLC cancer tissues and paired adjacent normal tissues were analyzed by immunohistochemistry. The effects of Abemaciclib on the proliferation, invasion and migration of SCLC were detected by CCK-8, colony formation assay, Transwell and migration assay. Western blot was used to detect the expressions of CDK4/6 and related transcription factors. Flow cytometry was used to analyze the effects of Abemaciclib on the cell cycle and checkpoint of SCLC. The expression of CDK4/6 was associated with c-Myc by STRING protein interaction network. c-Myc can directly modalize achaete-scute complex homolog 1 (ASCL1), neuronal differentiation 1 (NEUROD1) and Yes-associated protein 1 (YAP1). Moreover, CDK4 and c-Myc regulate the expression of programmed cell death ligand 1 (PD-L1). Immunohistochemistry showed that the expressions of CDK4/6 and c-Myc in cancer tissues were higher than those in adjacent tissues(P<0.0001). CCK-8, colony formation assay, Transwell and migration assay verified that Abemaciclib could effectively inhibit the proliferation, invasion and migration of SBC-2 and H446OE(P<0.0001). Western blot analysis further showed that Abemaciclib not only inhibited CDK4 (P<0.05) and CDK6 (P<0.05), but also affected c-Myc (P<0.05), ASCL1 (P<0.05), NEUROD1 (P<0.05) and YAP1 (P<0.05), which are related to SCLC invasion and metastasis. Flow cytometry showed that Abemaciclib not only inhibited the cell cycle progression of SCLC cells (P<0.0001), but also significantly increased PD-L1 expression on SBC-2 (P<0.01) and H446OE (P<0.001). Abemaciclib significantly inhibits the proliferation, invasion, migration and cell cycle progression of SCLC by inhibiting the expressions of CDK4/6, c-Myc, ASCL1, YAP1 and NEUROD1. Abemaciclib can also increase the expression of PD-L1 in SCLC.

Programmed cell death ligand 1 measurement study in granulocyte colony-stimulating factor-producing lung cancer: an observational study

BackgroundGranulocyte colony-stimulating factor (G-CSF)-producing lung cancer induces severe inflammation and a high white blood cell (WBC) count and is associated with poor prognosis. A recent case of G-CSF-producing lung adenocarcinoma showed high expression of programmed cell death ligand 1 (PD-L1) and was treated with pembrolizumab as first-line therapy, which was extremely effective. We hypothesized that G-CSF-producing lung cancers are associated with high PD-L1 expression.MethodsThis retrospective study included patients diagnosed with lung cancer at Yokohama Municipal Citizen’s Hospital (Kanagawa, Japan) between 2009 and 2019. The PD-L1 status of 13 patients with high plasma G-CSF levels (≥40 pg/mL) was assessed by conducting immunohistochemical analysis of tissue samples.ResultsOf the total patients, 11 were men and 2 were women, with a median age of 74 years (70–85 years). Four, five, and three patients had adenocarcinoma, squamous cell carcinoma, and others, respectively. The median G-CSF level and WBC count were 85.5 pg/mL (range, 40.8–484 pg/mL) and 15,550/μL (range, 6,190–56,800/μL), respectively. The PD-L1 tumor proportion scores (TPSs) were ≥50%, 1%–49%, and <1% in 9, 1, and 3 patients, respectively. The median overall survival time was 7.3 months. Pembrolizumab was administered in six patients as first-line treatment, with two patients showing partial response, one patient with stable disease, and three patients with progressive disease. All six patients had a PD-L1 TPS of ≥50%.ConclusionG-CSF-producing lung cancers may be associated with increased PD-L1 expression. Although immune checkpoint inhibitors are an important treatment option for G-CSF-producing tumors, their effects are limited.

HSP90α induces immunosuppressive myeloid cells in melanoma via TLR4 signaling

BackgroundTumor cells modulate host immunity by secreting extracellular vesicles (EV) and soluble factors. Their interactions with myeloid cells lead to the generation of myeloid-derived suppressor cells (MDSC), which inhibit the...

HGF/c-MET pathway contributes to cisplatin-mediated PD-L1 expression in hepatocellular carcinoma.

Cisplatin has been reported to promote the expression of programmed cell death ligand-1 (PD-L1) in some cancer cells. However, the underlying mechanism through which PD-L1 is transcriptionally regulated by cisplatin in hepatocellular carcinoma (HCC) cells remains largely unknown. In the present study, we found that the expression of hepatocyte growth factor (HGF), p-Akt, p-ERK, and PD-L1 was increased in cisplatin-treated SNU-368 and SNU-739 cells. HGF stimulation also increased PD-L1 expression in these cells. Moreover, Inhibition of HGF/c-MET, PI3K/Akt, and MEK/ERK signaling pathways can dramatically block cisplatin or HGF-induced PD-L1 expression in SNU-368 and SNU-739 cells. In vivo, combination PHA665752 with cisplatin significantly reduced tumor weight with increased infiltration of CD8+ T cells in the tumor. Taken together, our study suggested that HGF/c-Met axis-induced the activation of PI3K/Akt and MEK/ERK pathways contributes to cisplatin-mediated PD-L1 expression. These findings may provide an alternative avenue for the treatment of HCC.

Escherichia coli K12 Upregulates Programmed Cell Death Ligand 1 (PD-L1) Expression in Gamma Interferon-Sensitized Intestinal Epithelial Cells via the NF-κB Pathway.

Programmed cell death ligand-1 (PD-L1) is an immune checkpoint protein which is used by tumor cells for immune evasion. PD-L1 is upregulated in inflamed intestinal tissues. The intestinal tract is colonized by millions of bacteria, most of which are commensal bacterial species. We hypothesized that under inflammatory conditions, some commensal bacterial species contribute to increased PD-L1 expression in intestinal epithelium and examined this hypothesis. Human intestinal epithelial HT-29 cells with and without interferon (IFN)-γ sensitization were incubated with six strains of four enteric bacterial species. The mRNA and protein levels of PD-L1 in HT-29 cells were examined using quantitative real-time PCR and flow cytometry, respectively. The levels of interleukin (IL)-1β, IL-18, IL-6, IL-8, and tumor necrosis factor (TNF)-α secreted by HT-29 cells were measured using enzyme-linked immunosorbent assay. Apoptosis of HT-29 cells was measured using a caspase 3/7 assay. We found that Escherichia coli K12 significantly upregulated both PD-L1 mRNA and protein in IFN-γ-sensitized HT-29 cells. E. coli K12 induced the production of IL-8 in HT-29 cells, however, IL-8 did not affect HT-29 PD-L1 expression. Inhibition of the nuclear factor-kappa B pathway significantly reduced E. coli K12-induced PD-L1 expression in HT-29 cells. The other two E. coli strains and two enteric bacterial species did not significantly affect PD-L1 expression in HT-29 cells. Enterococcus faecalis significantly inhibited PD-L1 expression due to induction of cell death. Data from this study suggest that some gut bacterial species have the potential to affect immune function under inflammatory conditions via upregulating epithelial PD-L1 expression.

Safety and efficacy of AMG 820, an anti-colony-stimulating factor 1 receptor antibody, in combination with pembrolizumab in adults with advanced solid tumors

BackgroundTo determine the safety and efficacy of the anti-colony-stimulating factor 1 receptor (anti-CSF1R) monoclonal antibody AMG 820 in combination with pembrolizumab in patients with select solid tumors.Patients and methodsPatients had...

Inhibition of NF-κB is required for oleanolic acid to downregulate PD-L1 by promoting DNA demethylation in gastric cancer cells.

Gastric cancer is one of the most common causes of cancer-related death worldwide. Immunotherapy via programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) blockade has shown benefits for gastric cancer. Epigenetic DNA methylation critically regulates cancer immune checkpoints. We investigated how the natural compound oleanolic acid (OA) affected PD-L1 expression in gastric cancer cells. Interleukin-1β (IL-1β) at 20 ng/mL was used to stimulate human gastric cancer MKN-45 cells. IL-1β significantly increased PD-L1 expression, which was abolished by OA. Next, OA-treated MKN-45 cells were co-cultured with activated and PD-1-overexpressing Jurkat T cells. OA restored IL-2 levels in the co-culture system and increased T cell killing toward MKN-45 cells. Overexpression of PD-L1 eliminated OA-enhanced T cell killing capacity; however, PD-1 blocking antibody abrogated the cytotoxicity of T cells. Moreover, OA abolished IL-1β-increased DNA demethylase activity in MKN-45 cells. DNA methyltransferase inhibitor 5-azacytidine rescued OA-reduced PD-L1 expression; whereas DNA demethylation inhibitor gemcitabine inhibited PD-L1 expression, and, in combination with OA, provided more potent inhibitory effects. Furthermore, OA selectively reduced the expression of DNA demethylase TET3 in IL-1β-treated MKN-45 cells, and overexpression of TET3 restored OA-reduced PD-L1 expression. Finally, OA disrupted nuclear factor κB (NF-κB) signaling IL-1β-treated MKN-45 cells, and overexpression of NF-κB restored OA downregulation of TET3 and PD-L1. The cytotoxicity of T cells toward MKN-45 cells was also weakened by NF-κB overexpression. Altogether, OA blocked the IL-1β/NF-κB/TET3 axis in gastric cancer cells, leading to DNA hypomethylation and downregulation of PD-L1. Our discoveries suggested OA as an epigenetic modulator for immunotherapy or an adjuvant therapy against gastric cancer.

Integration of tumour infiltrating lymphocytes, programmed cell-death ligand-1, CD8 and FOXP3 in prognostic models for triple-negative breast cancer: Analysis of 244 stage I–III patients treated with standard therapy

BackgroundTumour infiltrating lymphocytes (TILs) are an established prognostic biomarker for triple-negative breast cancer (TNBC). We evaluated the role of programmed cell-death ligand-1 (PD-L1), CD8 and FOXP3 expression in refining a prognostic model for non-metastatic TNBC beyond classic factors and TILs. MethodsPrimary tumour samples from 244 early patients with TNBC, all treated with surgery and chemotherapy, were collected. Stromal TILs were evaluated on haematoxylin–eosin slides according to guidelines. PD-L1, CD8 and FOXP3 were assessed by immunohistochemistry and evaluated by digital pathology. ResultsTILs, PD-L1, CD8 and FOXP3 were positively correlated with each other (P < 0.001). TILs were confirmed as an independent prognostic factor. When PD-L1, CD8 and FOXP3 were added to multivariable models including classic factors (age, stage, histologic grade) and TILs, PD-L1 provided the largest amount of additional prognostic information: likelihood ratio χ2 4.60, P = 0.032 (in a model including classic factors and TILs 10% increments) and likelihood ratio χ2 6.50, P = 0.011 (in a model including classic factors and TILs >30% versus <30%). In the subset of patients treated with neoadjuvant chemotherapy, FOXP3 provided further prognostic information beyond classic factors, TILs and pathological complete response (pCR) (likelihood ratio χ2 5.01, P = 0.025). For patients who did not achieve a pCR, the expression of CD8 and PD-L1 was significantly increased from baseline to residual disease. ConclusionsBeyond clinicopathological factors and TILs, other immune biomarkers may add prognostic information for early TNBC. The increased PD-L1 expression on residual disease after neoadjuvant chemotherapy strengthens the rationale of testing immune checkpoint inhibitors in the post-neoadjuvant setting.

Molecular Imaging of PD-L1 Expression and Dynamics with the Adnectin-Based PET Tracer 18F-BMS-986192.

18F-BMS-986192, an adnectin-based human programmed cell death ligand 1 (PD-L1) tracer, was developed to noninvasively determine whole-body PD-L1 expression by PET. We evaluated the usability of 18F-BMS-986192 PET to detect different PD-L1 expression levels and therapy-induced changes in PD-L1 expression in tumors. Methods: In vitro binding assays with 18F-BMS-986192 were performed on human tumor cell lines with different total cellular and membrane PD-L1 protein expression levels. Subsequently, PET imaging was performed on immunodeficient mice xenografted with these cell lines. The mice were treated with interferon γ (IFNγ) intraperitoneally for 3 d or with the mitogen-activated protein kinase kinase inhibitor selumetinib by oral gavage for 24 h. Afterward, 18F-BMS-986192 was administered intravenously, followed by a 60-min dynamic PET scan. Tracer uptake was expressed as percentage injected dose per gram of tissue. Tissues were collected to evaluate ex vivo tracer biodistribution and to perform flow cytometric, Western blot, and immunohistochemical tumor analyses. Results:18F-BMS-986192 uptake reflected PD-L1 membrane levels in tumor cell lines, and tumor tracer uptake in mice was associated with PD-L1 expression measured immunohistochemically. In vitro IFNγ treatment increased PD-L1 expression in the tumor cell lines and caused up to a 12-fold increase in tracer binding. In vivo, IFNγ affected neither PD-L1 tumor expression measured immunohistochemically nor 18F-BMS-986192 tumor uptake. In vitro, selumetinib downregulated cellular and membrane levels of PD-L1 in tumor cells by 50% as measured by Western blotting and flow cytometry. In mice, selumetinib lowered cellular, but not membrane, PD-L1 levels of tumors, and consequently, no treatment-induced change in 18F-BMS-986192 tumor uptake was observed. Conclusion:18F-BMS-986192 PET imaging allows detection of membrane-expressed PD-L1 as soon as 60 min after tracer injection. The tracer can discriminate a range of tumor cell PD-L1 membrane expression levels.

Abstract OT1-08-01: A phase Ib trial of sequential combinations of BN-brachyury, entinostat, ado-trastuzumab emtansine (T-DM1) and bintrafusp alfa (M7824) in advanced stage breast cancer (BrEAsT)

Abstract Immune checkpoint blockade (ICB) monotherapy has produced limited benefit in breast cancer (BC) with response rates (RR) ranging from 5 to 23%. Combination ICB improved RR and progression free survival (PFS) resulting in atezolizumab + nab-paclitaxel receiving FDA accelerated approval for programmed cell death ligand 1 (PD-L1) positive, triple negative breast cancers (TNBC). BC has historically been considered immunologically quiet with most having a low mutational burden, low PD-L1 expression, defective antigen presentation machinery, and immuosuppressive signals in the tumor microenvironment (TME). An approach using a combination of immuno-oncology (IO) agents including ICB, immunomodulators and vaccines may shift the TME to allow for improved antigen presentation, the release of immunostimulatory cytokines, more immunogenic cell death and increased PD-L1 expression. The transcription factor brachyury plays an important role in breast tumor plasticity. High brachyury expression is associated with treatment resistance and a worse prognosis. Entinostat is a histone deacetylase inhibitor that has activity in multiple breast cancer subtypes. Preclinical data demonstrates entinostat upregulates MHC, enhances immune-mediated lysis and upregulates PD-L1 expression through epigenetic modification. Bintrafusp alfa is a bifunctional protein composed of the extracellular domain of the TGF-βRII receptor (TGF-β“trap”) fused to a human IgG1. Preclinical data shows bintrafusp alpha treatment increases T-cell trafficking, antigen-specific CD8+ T-cell lysis and NK cell activation. Monotherapy clinical studies with these agents have produced modest results in solid tumors, including BC. Preclinical data evaluating combinations of these agents shows a reduction in in tumor size, improved antigen-specific T-cell responses, reduced regulatory T cells, increased CD8+T-cells, and increased PD-L1 expression. We propose the stepwise addition of BN-Brachyury, Bintrafusp alfa, T-DM1 and Entinostat in advanced BC. This phase Ib study will assess efficacy and safety of the regimen and has three cohorts: Cohort 1(TNBC) will receive BN-Brachyury + Bintrafusp alfa. Cohort 2 (HER2+) will receive T-DM1 + BN-Brachyury + Bintrafusp alfa +/- entinostat. After safety is established in Cohort 2, patients in Cohort 3 (HER2+) will be assigned to receive T-DM1 + BN-Brachyury + Bintrafusp alfa +/- entinostat. Responses are evaluated every 2 cycles (6 weeks). Patients in Cohorts 2 and 3 will undergo research biopsies -baseline and after 2 cycles to evaluate changes within TME. Peripheral immune responses will be evaluated at selected time points. All patients must have measurable disease and HER2+ patients must have biopsiable disease. &amp;gt;1 prior treatment is required. Asymptomatic or brain metastases treated &amp;gt; 6 weeks are allowed. Well controlled HIV, HBV or treated HCV is allowed. Exclusion criteria include symptomatic brain metastases or clinically significant bleeding (&amp;lt;3 months from study entry). Co-primary objectives are RR and safety. Secondary objectives include PFS and changes in tumor infiltrating lymphocytes (Cohorts 2 and 3). Exploratory analyses include changes in immune cells and cytokines in the peripheral blood. Analyses performed will be descriptive, reporting the outcome measure for each treatment arm indicated along with two-tailed 80% and 95% confidence intervals. All cohorts employ a safety assessment in the initial 6 patients and a Simon minimax 2-stage design for clinical efficacy. We plan to recruit 51 patients: 13 patients with TNBC, 38 patients with HER2+BC. This trial will open Fall 2019 at the National Institutes of Health (Bethesda, MD). For more information contact the PI, Margaret.gatti-mays@nih.gov. Citation Format: Margaret E Gatti-Mays, Claudia Palena, Sofia R Gameiro, Renee N Donahue, Caroline Jochems, Seth Steinberg, Stan Lipkowitz, Alexandra Zimmer, Deneise Francis, Julius Strauss, Houssein Abdul Sater, Lisa Cordes, Jason Redman, Fatima Karzai, Marijo Bilusic, Ravi A Madan, James L Gulley, Jeffrey Schlom. A phase Ib trial of sequential combinations of BN-brachyury, entinostat, ado-trastuzumab emtansine (T-DM1) and bintrafusp alfa (M7824) in advanced stage breast cancer (BrEAsT) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT1-08-01.

Cisplatin-mediated down-regulation of miR-145 contributes to up-regulation of PD-L1 via the c-Myc transcription factor in cisplatin-resistant ovarian carcinoma cells.

Immune tolerance is one of the leading causes of chemotherapy resistance in carcinoma cases. Studies have shown that programmed cell death ligand-1 (PD-L1), an inhibitory molecule expressed by cancer cells, plays a significant role in immune tolerance through the induction of T cell dysfunction. The results of our RNA sequencing in previous studies revealed that microRNA-145 (miR-145), which is known to be down-regulated by cisplatin in cisplatin-resistant ovarian cancer cells, also represses gene PD-L1 expression. However, the mechanism by which miR-145 contributes to regulate PD-L1 expression in cisplatin resistance of ovarian cancer is yet to be fully understood. Here, we show that cisplatin-mediated miR-145 down-regulation increased PD-L1 expression via targeting the c-Myc transcription factor, thereby inducing T cell apoptosis in vitro. We also report that expression of miR-145 is negatively correlated with PD-L1 expression in human ovarian cancer tissues, malignant grades and the recurrent risks of ovarian cancer after chemotherapy. In summary, our findings suggest that the miR-145/c-Myc/PD-L1 axis contributes to cisplatin resistance in ovarian cancer and support that miR-145 might act as an adjuvant therapeutic target in chemotherapy of ovarian cancer.

MON-LB008 PD-L1 Expression in Normal Endocrine Tissues

Introduction: Immune checkpoint inhibitor (ICI) therapy, including cytotoxic T-lymphocyte-associated protein 4 (CLTA-4) and programmed cell death 1 (PD-1) inhibitors, is revolutionizing cancer treatment. However, these agents are associated with immune-related adverse events (irAEs), most commonly endocrine-related. Hypophysitis, thyroid dysfunction, insulin-deficient diabetes mellitus and primary adrenal insufficiency have been reported as irAEs due ICI therapy. The precise mechanisms underlying these endocrine irAEs remain to be elucidated. Aim: In this study, we evaluated patterns of programmed cell death ligand 1 (PD-L1) expression in normal endocrine tissues to determine whether increased expression may explain the predilection of endocrinopathies in patients treated with PD-1 inhibitors. Methods: Immunohistochemical (IHC) analysis using the Ventana 22C3 PD-L1 IHC platform was performed on normal FFPE endocrine tissue samples stored in our hospital pathology tissue archive. Results: Five samples from each organ including pituitary, thyroid, parathyroid, adrenal and pancreas were examined. Focal membranous PD-L1 positivity was noted in the normal pituitary tissues, but was negative in normal thyroid, parathyroid, adrenal and pancreatic tissues. Conclusions: Majority of normal endocrine tissues do not demonstrate increased PD-L1 expression. Our limited data so far does not support the hypothesis that increased PD-L1 expression in endocrine tissues is associated with the endocrine irAEs following anti PD-1 therapy. The increased predilection of endocrinopathies in patients treated with anti PD-1 inhibitors seems to be via alternate pathways. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Effect of anthracycline and taxane on the expression of programmed cell death ligand-1 and galectin-9 in triple-negative breast cancer

This study identified chemotherapeutic agents that up-regulate programmed cell death ligand-1 (PD-L1) and galectin-9 (Gal-9) in breast cancer cells. Immunohistochemical (IHC) staining was used to evaluate changes in PD-L1 and Gal-9 expression in the tumor tissue of triple-negative breast cancer (TNBC) patients who received anthracycline- and taxane-based neoadjuvant chemotherapy. To determine whether PD-L1 and Gal-9 expression changes were attributable directly to chemotherapeutics, MDA-MB-231 cells and HS578T cells were treated with different concentrations of anthracycline and taxane. Expression levels of PD-L1 and Gal-9 were evaluated and the activation status of NFκB in MDA-MB-231 and HS578T cells was determined to identify the PD-L1 and Gal-9 up-regulation mechanism. Three cases of increased PD-L1 expression and two of increased Gal-9 expression were observed among the TNBC patients. PD-L1 and Gal-9 expression were up-regulated by anthracycline and taxane in MDA-MB-231 cells, but not in HS578T cells. Increased nuclear levels of NFκB were observed in MDA-MB-231 cells treated with 0.5 μM epirubicin. Anthracycline and taxane up-regulated PD-L1 and Gal-9 expression in some subtypes of TNBC. This study provides useful reference data for clinical trials investigating combination treatments with immune checkpoint inhibitors and chemotherapy.

Osteoclast Immunosuppressive Effects in Multiple Myeloma: Role of Programmed Cell Death Ligand 1.

Immunomodulatory drugs and monoclonal antibody-based immunotherapies have significantly improved the prognosis of the patients with multiple myeloma (MM) in the recent years. These new classes of reagents target malignant plasma cells (PCs) and further modulate the immune microenvironment, which prolongs anti-MM responses and may prevent tumor occurrence. Since MM remains an incurable cancer for most patients, there continues to be a need to identify new tumor target molecules and investigate alternative cellular approaches using gene therapeutic strategies and novel treatment mechanisms. Osteoclasts (OCs), as critical multi-nucleated large cells responsible for bone destruction in >80% MM patients, have become an attractive cellular target for the development of novel MM immunotherapies. In MM, OCs are induced and activated by malignant PCs in a reciprocal manner, leading to osteolytic bone disease commonly associated with this malignancy. Significantly, bidirectional interactions between OCs and MM cells create a positive feedback loop to promote MM cell progression, increase angiogenesis, and inhibit immune surveillance via both cell–cell contact and abnormal production of multiple cytokines/chemokines. Most recently, hyper-activated OCs have been associated with activation of programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway, which impairs T cell proliferation and cytotoxicity against MM cells. Importantly, therapeutic anti-CD38 monoclonal antibodies and checkpoint inhibitors can alleviate OC-induced immune suppression. Furthermore, a proliferation-inducing ligand, abundantly secreted by OCs and OC precursors, significantly upregulates PD-L1 expression on MM cells, in addition to directly promoting MM cell proliferation and survival. Coupled with increased PD-L1 expression in other immune-suppressive cells, i.e., myeloid-derived suppressor cells and tumor-associated macrophages, these results strongly suggest that OCs contribute to the immunosuppressive MM BM microenvironment. Based on these findings and ongoing osteoimmunology studies, therapeutic interventions targeting OC number and function are under development to diminish both MM bone disease and related immune suppression. In this review, we discuss the classical and novel roles of OCs in the patho-immunology of MM. We also describe novel therapeutic strategies simultaneously targeting OCs and MM interactions, including PD-1/PD-L1 axis, to overcome the immune-suppressive microenvironment and improve patient outcome.

Abstract 3625: MET signaling upregulates PD-L1 expression in human lung and gastric cancer

Abstract Background: Tyrosine kinase receptor, MET, plays an important role for the progression of tumor through diverse mechanisms. Cancer immunotherapy targeting PD-1/PD-L1 pathway shows clinical benefit in patient with PD-L1 expressing solid tumor. In our previous study on non-small cell lung cancer (NSCLC) using immunohistochemistry, MET overexpression was significantly associated with programmed cell death-ligand 1 (PD-L1) overexpression. Thus, we investigated if MET signaling pathway is involved in PD-L1 expression in tumor cells. Method and Result: Lung adenocarcinoma cell lines including H596 (harboring MET exon 14 skipping mutation), H1993 (harboring MET gene amplification), H23 and H522 (MET wild-type), and a gastric carcinoma cell line, Hs746T (harboring MET exon 14 skipping mutation and gene amplification) were used. Hs746T cells were treated with MET inhibitor or transfected with MET siRNA and subject to microarray analysis. MET inhibition or knockdown led to changes in expression level of variable immune-related molecules, of which PD-L1 was one of the most down-regulated molecules. Stimulation of H596, H23 and H522 cells with HGF, a MET ligand, increased PD-L1 expression at the mRNA and protein level. Treatment of H1993 and Hs746T cells with MET inhibitor or MET knockdown using siRNA resulted in down-regulation of PD-L1 at the mRNA, total protein, and surface expression levels. PI3K/Akt and MAPK/Erk signaling pathways were involved in MET-mediated PD-L1 up-regulation in H1993 and Hs746T cells. Finally, the Cancer Genome Atlas (TCGA) analysis showed that MET and PD-L1 expression are significantly positively correlates with each other in patients with lung cancer (in NSCLC, rho=0.219 [p&amp;lt;0.001]; in adenocarcinoma, r=0.401 [p&amp;lt;0.001]; in squamous cell carcinoma, r=0.144 [p=0.001]) and in patients with gastric cancer (r=0.137 [p=0.005]). Conclusion: This study demonstrates that MET signaling increases PD-L1 transcription and protein overexpression in lung and gastric cancer cells, which might contribute to immune escape of tumor via PD-1/PD-L1 pathway. MET-targeted therapy may be considered as combination therapy with PD-1/PD-L1 blockades. Citation Format: Hyunkyung Ahn, Sehui Kim, Ji Young Jang, Dohee Kwon, Jaemoon Koh, Young A Kim, Doo Hyung Chung, Yoon Kyung Jeon. MET signaling upregulates PD-L1 expression in human lung and gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3625.

Abstract 2366: The tyrosine phosphatase, SHP-2, participates in regulating PD-L1 expression in non-small cell lung cancer

Abstract Immune checkpoint inhibitors, specifically those which target T cell surface receptor Programmed Cell Death-1 (PD-1) and its ligand, Programmed cell death ligand-1 (PD-L1), have demonstrated clinical benefit in patients with non-small cell lung cancer (NSCLC). Currently, tumor expression of PD-L1 serves as the FDA-approved companion diagnostic for response to anti-PD-1/PD-L1 therapy. However, a fraction of patients who express PD-L1 exhibit a response to treatment, and in some cases, patient tumors that do not express PD-L1 demonstrate response to therapy, making this a poor predictive biomarker. Further, the mechanism by which PD-L1 expression is controlled remains under-studied. In this study, we seek to determine the impact of the protein tyrosine phosphatase, SHP-2, on PD-L1 expression through Jak/STAT- mediated signaling in NSCLC cell lines. SHP-2 can harbor activating mutations which prevent auto-inhibition of the catalytic phosphatase domain, and that may be pro-tumorigenic in some tumors. To understand the impact of SHP-2 activity on PD-L1 expression, we first assessed activation of STAT3 in NSCLC tumor cells after treatment with IFNγ and other mitogens. We then transfected NSCLC cells with wildtype and hyperactive SHP-2 mutants or ablated SHP-2 with siRNA specific for SHP-2 and measured both STAT3 and PD-L1 expression. Cell lines A549 and H661 exhibit low endogenous expression of both SHP-2 and PD-L1, and thus were chosen for transfection with hyperactive SHP-2 mutants (E76K and G503V), which also altered PD-L1 expression by western blot analysis. Quantitative real-time PCR (qPCR) and western blot analysis revealed that siRNA ablation of SHP-2 led to increased PD-L1 expression in the H460 cell line. Cells transfected with the SHP-2 activating mutants will also be assessed alteration of cell proliferation. Finally, using data obtained from The Cancer Genome Atlas project, STAT3 and PD-L1 expression levels are being evaluated in NSCLC tumor samples in which SHP-2 is mutated (E76K or G503V). With these data, we expect to gain a more complete understanding of the role of SHP-2 within the tumor microenvironment and the extent to which it controls PD-L1 expression, leading to new drug targets or combinations of drugs and better predictive biomarkers of response to PD-1 and PD-L1 inhibitors. Citation Format: Keller Toral, Brent Harris, Jarrod Creameans, Penni Black. The tyrosine phosphatase, SHP-2, participates in regulating PD-L1 expression in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2366.