Cell Death Receptor Research Articles

Pilot Study of the Performance of 19-G Needle in Endobronchial Ultrasound-guided Transbronchial Aspiration for the Diagnosis and Testing of Molecular Markers in Lung Cancer.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has become the standard for diagnosis and staging of lung cancer. Historically, 21- and 22-G needles have been paired with EBUS. We evaluated the performance of EBUS-TBNA using a larger 19-G needle in the assessment of tumor tissue obtained and success of testing for molecular markers. We prospectively enrolled adult patients with lymphadenopathy concerning for metastatic lung cancer. Patients underwent diagnostic EBUS-TBNA utilizing 19-G needles. Cases of non-small cell lung cancer (NSCLC) were evaluated for programmed cell death receptor ligand (PD-L1) expression. Cases of adenocarcinoma or undifferentiated NSCLC were further evaluated for 3 molecular markers for driver mutations: epidermal growth factor receptor (EGFR), c-ros oncogene 1 (ROS-1), and anaplastic lymphoma kinase (ALK). Fifty patients were enrolled and underwent EBUS-TBNA using 19-G needles. PD-L1 assay was successfully performed in 90% of NSCLC cases. In adenocarcinoma or undifferentiated NSCLC cases, the success rate in testing was 90% for EGFR and 86% for ALK. ROS-1 testing had a success rate of 67%; 24% of these specimens had adequate tumor cells but there was technical difficulty with the assay. Block quality was judged by total number of tumor cells per hematoxylin and eosin-stained slide of each cell block (58% of specimens had >500 cells and 22% had 200 to 500 cells). There were no adverse events. EBUS-TBNA using 19-G needles can obtain a high number of tumor cells and has a high rate of success in performing assays for PD-L1, EGFR, and ALK in NSCLC patients without an increase in adverse events. The success rate of ROS-1 testing was lower.

The Effect of Swimming Endurance Exercise on Cell Death and Nicotinic Acetylcholine Receptor Gene Expression in Brain of Rat: An Experimental Study of Alzheimer's Disease Model

The Effect of Swimming Endurance Exercise on Cell Death and Nicotinic Acetylcholine Receptor Gene Expression in Brain of Rat: An Experimental Study of Alzheimer's Disease Model

Prognostic Role of Inflammasome Components in Human Colorectal Cancer.

Simple SummaryInflammasomes are critically involved in gut epithelial homeostasis, immunosurveillance and in controlling tumorigenesis mechanisms. Data on the role of inflammasomes in tumorigenesis are mostly provided by transcriptomic analyses of bulk tumors, eluding a potential specific role of intrinsic epithelial inflammasomes. Therefore, we investigated the expression of inflammasome components in intestinal epithelial cells, at the protein level in patient tissues and assessed the correlation with clinicopathological parameters. We found that downregulation of the epithelial expression of NOD-like receptor family pyrin domain containing 6 (NLRP6) and IL-18 was associated with more advanced disease and worse patients’ outcome. Furthermore, the loss of both epithelial and stromal IL-18 was also associated with worse disease outcome. Finally, we identified an epithelial innate immune protein profile combining NLRP6 and IL-18 that stratified patients for better clinical prognosis. Together, analysis of epithelial inflammasomes may help clinical decisions for better prognostic assessment and may identify new therapeutic targets in colorectal cancer.(1) We wanted to assess the prognostic impact of inflammasomes involved in gut epithelial homeostasis and the development of human colorectal cancer (CRC). (2) We investigated the expression of inflammasome components in colonic epithelial cells at the protein level in patient tissues, through an immunofluorescence assay. (3) In a cohort of 104 patients, we found that all inflammasome components were downregulated in CRC. Loss of epithelial (but not stromal) expression of NLRP6, caspase-1 and IL-18 was associated with an increased mortality of 72%, 58% and 68% respectively and to disease progression into metastasis. The loss of epithelial and stromal IL-18 but not NLRP6, was associated to lower tumor immune infiltrates in the lymphoid compartment and higher Programmed cell Death receptor 1 (PD-1) expression. Finally, we found that combined downregulation of IL-18 and NLRP6 was associated with a worse outcome. Indeed, 5-year survival rates were 26% for the NLRP6low/IL-18low tumors, compared to 64.4% for the entire cohort. This downregulation was associated with a more advanced disease (p < 0.0001) and a trend to lower lymphoid cell infiltration. (4) We identified critical inflammasome markers that may help in better stratifying patients for prognosis in CRC and could help clinicians to determine which patients may benefit from immunotherapies.

Lung Cancer Immunotherapy in Transplant Patients and in Patients With Autoimmune Diseases.

The use of immune checkpoint inhibitors (ICIs) delivered great and new possibilities in modern treatment of many types of cancers. This therapy based on blockade of such molecules as CTLA-4 (cytotoxic T lymphocyte-associated antigen), PD-1 (programmed cell death receptor type 1), or PD-1 ligand (PD-L1) brings a new hope for patients with non-small cell lung cancer (NSCLC), melanoma, or head and neck squamous carcinoma. Efficacy of immunotherapy was proven in many clinical trials. Unfortunately, ICIs treatment was not addressed to the patients with preexisting allogeneic transplants or autoimmune diseases mainly due to high risk of transplant rejection, exacerbation of autoimmune diseases, and risk of serious toxicity. However, it is possible to receive anti-tumor response to ICIs treatment avoiding graft rejection by adjusting the immunosuppression. Obviously, it depends on the type of transplants: the use of immunotherapy is usually possible in kidney or corneal recipients, but it could be difficult in patients with liver and heart transplant. Therefore, the development of biomarkers for tumor response and transplant rejection in ICIs treated patients is essential. Data coming from published literature support the possibilities of using ICIs in patients with preexisting autoimmune diseases who undergoing proper management of side effects of immunotherapy or when the potential benefits of such treatment outweigh the potential risks. This depends on the type of autoimmune disease and may be difficult or not feasible in patients with systemic lupus erythematosus or systemic sclerosis. Therefore, it may be appropriate to include cancer patients with preexisting autoimmune disease or with allogeneic transplants in clinical trials using immunotherapy when no other effective cancer treatment options exist.

Meta-Analysis of PD-L1 Expression As a Predictor of Survival After Checkpoint Blockade.

Programmed cell death receptor ligand 1 (PD-L1) expression is the most studied biomarker to predict the efficacy of immune checkpoint inhibitors (ICIs), but its clinical significance is controversial. We estimated the distribution of PD-L1 expression scores (ie, tumor proportion score or combined proportion score) and the relationship between PD-L1 levels and ICIs' impact on overall survival (OS). We reconstructed, pooled, and analyzed individual-level data on 7,617 patients with cancer from 14 randomized clinical trials. The effects of ICIs were quantified using differences in 24-month restricted mean survival times (ΔRMSTs; ie, the increase in life expectancy truncated at 2 years associated with ICI therapy). In a simulation study, we compared standard randomized clinical trial designs with a trial design that leverages meta-analytic results like ours. Approximately 93% of patients had a PD-L1 expression ≤ 5% (66% of patients) or > 50% (27% of patients). OS improves with ICIs regardless of PD-L1 expression level, which predicts the benefits' magnitude. For patients with non-small-cell lung cancer (NSCLC), ΔRMSTs ranged from 1.4 months (95% probability interval [PI], 0.7 to 2.2 months) for PD-L1 expression ≤ 1% to 4.1 months (95% PI, 3.2 to 5.2 months) for PD-L1 expression > 80%. For patients with non-NSCLC tumors, ΔRMSTs ranged from 0.8 months (95% PI, -0.1 to 1.7 months) to 2.3 months (95% PI, 1.3 to 4.4 months), again for PD-L1 expression levels of ≤ 1% and > 80%, respectively. Simulations suggested that designs tailored to meta-analytic results can detect the effects of ICIs in PD-L1 subgroups with higher probability (> 15%) than standard designs. The practice of dichotomizing the range of PD-L1 expression scores is inadequate for patient stratification. Meta-analytic estimates of the distribution of PD-L1 scores and subgroup-specific treatment effects can improve the designs of future trials of ICIs.

Predicting Clinical Outcomes of Patients with Stage III Non-Small-Cell Lung Cancer Treated with Concurrent Chemoradiation with and without PD-1/PD-L1 Inhibitors Using Cone Beam Computed Tomography

Currently, there are no standardized biomarkers that predict response to consolidative therapy with Programmed cell Death receptor -1(PD-1) or Programmed cell Death receptor -Ligand 1 (PD-L1) inhibitors used after concurrent chemoradiation therapy (CCRT) for patients with stage III unresectable locally advanced non-small-cell lung cancer (LA-NSCLC).We hypothesized that tumor volume reduction during CCRT may be predictive of response to consolidative PD-1/PDL-1 inhibitors. We retrospectively reviewed the medical records of patients treated with definitive CCRT, both with and without consolidative PD-1/PD-L1 inhibitors. CCRT consisted of 60Gy in 30 fractions with platinum-based chemotherapy doublet. Primary gross tumor volumes (GTV) of all patients were contoured on set-up cone-beam computed tomography (CBCT) scans acquired on day 1, 15, 29, and 43 of CCRT, as well as on follow-up CT at 1 month. GTV reduction was quantified as the percent difference in volume on each CBCT and follow-up CT, relative to CBCT Day 1. Mid-treatment shrinkage (MTS) and End of Treatment Tumor Shrinkage (ETTS) were defined at day 29 and 43, respectively. Progression-free survival (PFS) was calculated using Kaplan-Meier curves and the log-rank test was used for statistical evaluation. 93 LA-NSCLC patients completed definitive CCRT, of which 24 received consolidative PD-1/PD-L1 inhibitors. For the entire cohort, the median age was 66.5 years (range: 51-84 years) and 54% were males. Adenocarcinoma represented 51%, squamous cell carcinoma 40% and undifferentiated histology 9%. 32% had stage IIIA and 68% had stage IIIB (AJCC 7th edition). Median follow-up was 43 months (range: 36-53 months). Patients who received PD-1/PD-L1 inhibitors achieved significantly longer PFS than CCRT-only group (22.5 vs. 9.5 months, p = 0.014). For the 93 patients, median ETTS was 40.6% (range: 39.3-50.3). Median ETTS was comparable between PD-1/PD-L1 inhibitors and CCRT-only group (41.2% vs. 40%). Patients who received PD-1/PD-L1 inhibitors and achieved ETTS > 35% demonstrated a trend toward improved PFS compared to those who had ETTS ≤ 35% (median PFS was not reached vs. 11.03 months, p = 0.059). Similarly, patients who received PD-1/PD-L1 inhibitors and achieved MTS of > 35% were associated with numerically better PFS compared to patients who did not achieve the same cut off (median PFS was not reached vs. 13.15 months, p = 0.059). Patients who achieved a significant reduction in their tumor volume during CCRT are more likely to benefit from consolidative PD-1/PD-L1 inhibitors. Measuring tumor volume dynamics using the readily available CBCT images acquired during CCRT may serve as a potential biomarker to predict response to PD-1/PD-L1 inhibition therapy.

Impact of hypoxia-ischemia and dopamine treatment on dopamine receptor binding density in the preterm fetal sheep brain.

Dopamine is often used to treat hypotension in preterm infants who are at risk of hypoxic-ischemic (HI) brain injury due to cerebral hypoperfusion and impaired autoregulation. There is evidence that systemically administered dopamine crosses the preterm blood-brain barrier. However, the effects of exogenous dopamine and cerebral HI on dopaminergic signaling in the immature brain are unknown. We determined the effect of HI and dopamine on D1 and D2 receptor binding and expressions of dopamine transporter (DAT) and tyrosine hydroxylase (TH) in the striatum of the preterm fetal sheep. Fetal sheep (99 days of gestation, term = 147days) were unoperated controls (n = 6) or exposed to severe HI using umbilical cord occlusion and saline infusion (UCO + saline, n = 8) or to HI with dopamine infusion (UCO + dopamine, 10 µg/kg/min, n = 7) for 74 h. D1 and D2 receptor densities were measured by autoradiography in vitro. DAT, TH, and cell death were measured using immunohistochemistry. HI resulted in cell death in the caudate nucleus and putamen, and dopamine infusion started before HI did not exacerbate or ameliorate these effects. HI led to reduced D1 and D2 receptor densities in the caudate nucleus and reduction in DAT protein expression in the caudate and putamen. Fetal brains exposed to dopamine in addition to HI were not different from those exposed to HI alone in these changes in dopaminergic parameters. We conclude that dopamine infusion does not alter the striatal cell death or the reductions in D1 and D2 receptor densities and DAT protein expression induced by HI in the preterm brain.NEW & NOTEWORTHY This is the first study on the effects of hypoxia-ischemia and dopamine treatment on the dopaminergic pathway in the preterm brain. In the striatum of fetal sheep (equivalent to ∼26-28 wk of human gestation), we demonstrate that hypoxia-ischemia leads to cell death, reduces D1 and D2 receptors, and reduces dopamine transporter. Intravenous dopamine infusion at clinical dosage used in preterm human infants does not alter the striatal cell death, D1 and D2 receptor density levels, and DAT protein expressions after hypoxia-ischemia in the preterm brain.

Cancer-Associated Fibroblasts-Derived Exosomes Suppress Immune Cell Function in Breast Cancer via the miR-92/PD-L1 Pathway.

Cancer-associated fibroblasts (CAFs) are an essential component in the tumor microenvironment and have been reported to contribute to tumor progression through many mechanisms; however, the detailed mechanism underlying the immune-suppression effect of CAFs is not clearly defined. In this study, human breast cancer-derived CAFs were cultured, and CAF-derived exosomes in a culture medium were isolated. Using a miRNA profiles assay, we identify a significantly higher level of microRNA-92 isolated in CAFs exosomes. After treatment by CAF-derived exosomes, breast cancer cells express higher programmed cell death receptor ligand 1 (PD-L1), accompanied with increased miR-92 expression. Increased PD-L1 expression, which was induced by CAF-derived exosomes, significantly promotes apoptosis and impaired proliferation of T cells. The underlying mechanism of this effect was studied, proliferation and migration of breast cancer cells were increased after the transfection of miR-92, LATS2 was recognized as a target gene of miR-92, and further confirmed by a luciferase assay. Immunoprecipitation showed that LATS2 can interact with YAP1, chromatin immunoprecipitation confirmed that after nuclear translocation YAP1 could bind to the enhancer region of PD-L1 to promotes transcription activity. Furthermore, the animal study confirmed that CAFs significantly promoted tumor progression and impaired the function of tumor-infiltrated immune cells in vivo. Our data revealed a novel mechanism that can induce immune suppression in the tumor microenvironment.

A Diamine-PEGylated Oleanolic Acid Derivative Induced Efficient Apoptosis through a Death Receptor and Mitochondrial Apoptotic Pathway in HepG2 Human Hepatoma Cells.

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Our recent studies have shown that the diamine-(PEG)ylated oleanolic acid (OADP) has strong anti-tumor effects in HCCs. In this study, we evaluated the anti-tumor mechanisms of OADP in the HepG2 HCC cell line. The cytotoxicity results showed that HepG2 cell viability was markedly reduced, with a very low 50% of cell growth inhibitory concentration (IC50, 0.14 µg/mL). We then investigated the anti-tumor mechanisms of OADP in HepG2 cells. The flow-cytometry analysis was used to evaluate cell apoptosis, indicating that 74–95% of cells were apoptotic. OADP caused cell cycle arrest in the G0/G1 phase and the loss of the mitochondrial membrane potential (MMP). Western blot analysis was performed to assess the expression levels of key proteins associated with the underlying molecular mechanism. The results showed the clear upregulation of caspase-8, caspase-9, caspase-3, Bak, p21, and p53, accompanied by the downregulation of Bcl-2. Similar results were obtained by the cotreatment with OADP and the c-Jun N-terminal kinase (JNK) inhibitor SP600125. Agents such as OADP, which are capable of activating extrinsic and intrinsic apoptotic pathways, may represent potential HCC cancer therapies.

Phase I, first-in-human trial of programmed cell death receptor-1 (PD-1) inhibitor, JTX-4014, in adult patients with advanced, refractory, solid tumors

BackgroundInhibition of programmed cell death receptor protein-1 (PD-1) has proven to be a highly effective strategy for immunotherapy of cancer. Approvals of both PD-1 and PD-L1 inhibitors [PD-(L)1i] in multiple tumor types are evidence of the durable benefits they provide to patients with cancer. In this first-in-human trial, we assessed the safety and tolerability of JTX-4014, a fully human antibody targeting PD-1.MethodsJTX-4014 was administered to 18 patients with multiple solid tumor types who had not previously received a PD-(L)1i. The primary objectives were to evaluate the safety and tolerability of JTX-4014 and determine the maximum tolerated dose (MTD) and recommended phase II dose (RP2D). Secondary objectives included evaluation of the pharmacokinetics (PK) of JTX-4014, anti-drug antibodies (ADA) against JTX-4014, and clinical activity.ResultsJTX-4014 was well tolerated and no new safety signals were identified as compared with other PD-1is. The MTD was not reached and the RP2D was selected, based on PK modelling and supportive safety data, to be 500 mg every 3 weeks or 1000 mg every 6 weeks. Clinical activity, based on RECIST v1.1 criteria, demonstrated an overall response rate of 16.7% (n = 3) with one complete and two partial responses and a disease control rate of 44.4% (n = 8). The responses occurred at different doses in patients with PD-L1 positive tumors and in tumor types that are not typically PD-1i responsive.ConclusionsFurther development of JTX-4014 is warranted as a monotherapy or in combination with other innovative cancer therapies.Trial registration numberNCT03790488, December 31 2018.

Integrated genomic analysis identifies a genetic mutation model predicting response to immune checkpoint inhibitors in melanoma.

Several biomarkers such as tumor mutation burden (TMB), neoantigen load (NAL), programmed cell‐death receptor 1 ligand (PD‐L1) expression, and lactate dehydrogenase (LDH) have been developed for predicting response to immune checkpoint inhibitors (ICIs) in melanoma. However, some limitations including the undefined cut‐off value, poor uniformity of test platform, and weak reliability of prediction have restricted the broad application in clinical practice. In order to identify a clinically actionable biomarker and explore an effective strategy for prediction, we developed a genetic mutation model named as immunotherapy score (ITS) for predicting response to ICIs therapy in melanoma, based on whole‐exome sequencing data from previous studies. We observed that patients with high ITS had better durable clinical benefit and survival outcomes than patients with low ITS in three independent cohorts, as well as in the meta‐cohort. Notably, the prediction capability of ITS was more robust than that of TMB. Remarkably, ITS was not only an independent predictor of ICIs therapy, but also combined with TMB or LDH to better predict response to ICIs than any single biomarker. Moreover, patients with high ITS harbored the immunotherapy‐sensitive characteristics including high TMB and NAL, ultraviolet light damage, impaired DNA damage repair pathway, arrested cell cycle signaling, and frequent mutations in NF1 and SERPINB3/4. Overall, these findings deserve prospective investigation in the future and may help guide clinical decisions on ICIs therapy for patients with melanoma.

Alopecia areata as an immune-related adverse event of immune checkpoint inhibitors: A review.

Immune checkpoint inhibitors (ICI) improve the ability of the immune system to target cancer cells by blocking signaling through either the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death (PD-1) receptor, or its ligand (PD-L1). They have been found to cause a variety of immune-related adverse events (irAEs) including a form of nonscarring alopecia that resembles alopecia areata (AA) in presentation and histology. Clinical features of ICI-induced AA are poorly described. We queried the Pubmed database for cases of AA secondary to ICI use reporting on extent of hair loss, treatments attempted, alopecia outcome, and time of follow-up with 13 cases identified. Although most patients had localized hair loss with subsequent regrowth, four of them experienced extensive and persistent AA, lasting up to a year. All but one patient continued ICI after the onset of hair loss. Many used topical corticosteroids with varying outcomes. Possible prognostic factors for severe and persistent disease may include young age and male sex. However, the low number of reported cases limits the generalizability of these findings. Tumor response was positive in every case of immune-induced AA where it was reported. Further investigation will be needed to better characterize clinical features of this irAE, risk factors for persistent disease, and determine its optimal management.

Steroid-responsive pancreatitides.

Autoimmune pancreatitis has received considerable attention, especially due to the marked effect of corticosteroid therapy on its clinical course. Knowledge, especially regarding type 1 autoimmune pancreatitis, has significantly increased over the last decades, and despite significant differences in pathophysiology and outcomes, both type 1 and 2 autoimmune pancreatitis are still considered different types of the same disease. Some have proposed a different nomenclature reflecting these differences. Although the term steroid-responsive pancreatitides may be interpreted as synonymous to type 1 and 2 autoimmune pancreatitis, these are not the only pancreatic conditions that show a response to steroid therapy. Acute pancreatitis caused by vasculitis and connective tissue diseases and acute pancreatitis secondary to checkpoint inhibitors or programmed cell death receptor antibody-mediated blockage cancer therapy may also benefit from steroid treatment. This review presents current concepts on these disorders, aiming to increase awareness, analyze similarities and differences, and propose a new nomenclature that reflects their specific particularities, clustering them under the term “steroid-responsive pancreatitides”.

Abstract 6325: CXCR4 intracellular protein regulates chemotherapy resistance by modulating the expression of death receptor 5

Abstract Chemotherapy resistance is one of the pivotal reasons for cancer-associated huge mortality and morbidity. Cancer cells become therapy resistant by smartly evading the execution of apoptosis. Death Receptors (DR) are critical pro-apoptotic factors that regulate cell death, and paucity of death receptors in cancer cells promotes therapy resistance. High expression of CXCR4 is strongly correlated with poor prognosis and adverse clinical outcomes. Inhibitors of the CXCL12-CXCR4 axis, such as FDA approved drug plerixafor (AMD3100), and Nox-A12 have shown limited clinical success in cancer treatment. Alternately, CXCR7, another CXCL12 binding receptor, could be the reason for the limited success of the CXCR4 blockade in clinics. However, recent preclinical data for blocking both the chemokine receptors failed to explain the pro-tumorigenic functions of these axes. Therefore, CXCR4-CXCL12 signaling may not be the exclusive contributor to its pro-tumorigenic functions. In our continuous effort to understand the chemokine receptor signaling inhibition as cancer therapy, here we unexpectedly discovered that instead of CXCR4-CXCL12 signaling, CXCR4 intracellular protein augments therapy resistance and pro-tumorigenic functions. By utilizing stable gain and loss of function approaches, we observed that CXCR4 selectively resists and sensitizes cancer cells against paclitaxel therapy. Our unbiased apoptosis array followed by immunoblot, FACS, real-time PCR, and ChIP analysis clearly demonstrate that CXCR4 promotes downregulation of pro-apoptotic protein DR5 via modulating differential recruitment of transcription factors p53 and YY1 to the promoter of DR5 gene. Inhibiting CXCR4 mediated signals failed to block the above phenotype. Irrespective of CXCR4 surface expression, three different colon cancer xenograft models evidently exhibited loss of CXCR4 protein results in compromised colon tumor growth in vivo. Finally, performing TCGA data mining, real-time PCR, immunofluorescence microscopy of human cancer patient samples and cell lines, we observed that expression of CXCR4 and DR5 are inversely correlated in human cancer. Together, we showed for the first time that targeting intracellular CXCR4 protein may be critical to dampen the pro-tumorigenic functions of CXCR4. Citation Format: Mushtaq Ahmad Nengroo, Shrankhla Maheshwari, Akhilesh Singh, Anup Kumar Singh, Priyank Chaturvedi, Ayushi Verma, Rakesh Kumar Arya, Krishan Kumar Saini, Annapurna Gupta, Anjali Mishra, Dipak Datta. CXCR4 intracellular protein regulates chemotherapy resistance by modulating the expression of death receptor 5 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6325.

Abstract CT138: Molecular markers in a phase I dose expansion study of PF-06801591 in locally advanced or metastatic non-small-cell lung cancer and urothelial carcinoma

Abstract Introduction: PF-06801591 is a humanized IgG4 monoclonal antibody that binds to the programmed cell death (PD-1) receptor and blocks its interaction with PD-1/2 ligands (PD-L1/2). In a phase 1 dose expansion study (NCT02573259), 106 patients with locally advanced or metastatic non-small cell lung cancer (NSCLC; n=68) or urothelial carcinoma (UC; n=38) were treated with PF-06891591 300 mg subcutaneously monthly. 12 patients with NSCLC (17.9%) and 7 with UC (18.4%) had a best overall response of partial response (PR). Response rates were higher in patients with high (≥1%) vs low (&amp;lt;1%) tumor cell membrane PD-L1 staining. In UC, progression-free survival (PFS) was longer in patients with high PD-L1 expression. In NSCLC, higher baseline tumor mutational burden (TMB) was associated with longer overall survival (OS). Here, further analyses were conducted to evaluate possible additional predictive biomarkers. Methods: Baseline biopsies were required from all enrolled patients. Archival samples were collected from 95 patients (58 NSCLC; 37 UC); and fresh de novo samples from 11 patients (10 NSCLC; 1 UC). PD-L1 (clone SP-263) and panCK/CD8 expression were evaluated in formalin-fixed, paraffin-embedded tumor biopsies by immunohistochemistry (IHC) and pathologist scoring and/or digital image analysis. Whole-exome sequencing and RNA sequencing were profiled on tumor tissue to generate TMB and gene expression measurements. Cox Proportional Hazards model or logistic regression were used to identify baseline TMB, genes, and pathways potentially associated with outcomes. Results: In NSCLC, high baseline CD8 protein expression in certain tumor compartments was associated with better objective response rate (ORR), PFS and OS. High TMB was associated with prior smoking status and better ORR. Furthermore, RNA sequencing showed that gene expression signatures of CD8+ T cells and cell cycle activity were associated with better clinical response, whereas neutrophil signatures were associated with poor response. In UC, certain high baseline CD8 levels by IHC were associated with better ORR, PFS and OS. Additionally, enrichment of several immune gene signatures was associated with improved ORR. Effector memory CD8+ T cells by RNA sequencing deconvolution were associated with PFS. In a Hallmark pathway analysis, pathways associated with immune activation comprised the majority of those significantly upregulated in responders vs non-responders. Conclusion: Despite a relatively small sample size and a range of biopsy collection dates prior to PF-06801591 treatment, several baseline tumor tissue biomarkers, beyond PD-L1 expression, were associated with clinical benefit in patients with NSCLC and UC. Higher TMB, immune signatures and CD8 cells at baseline may facilitate the immunomodulatory activity of anti-PD1 therapy resulting in an enhanced anti-tumor immune response. Citation Format: Byoung Chul Cho, Konstantin Penkov, Igor Bondarenko, Joanna Pikiel, Hee Kyung Ahn, Alison Forgie, Ira Jacobs, Vinicius Bonato, Xinmeng Jasmine Mu, Keith Ching, Jeffrey Chou, Melissa L. Johnson. Molecular markers in a phase I dose expansion study of PF-06801591 in locally advanced or metastatic non-small-cell lung cancer and urothelial carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT138.

Potential and unsolved problems of anti-PD-1/PD-L1 therapy combined with radiotherapy.

Tumor immunotherapy has become one of the main treatments for tumors. Inhibition of the pathways involving programmed cell death receptor 1 (PD-1) and its ligand (PD-L1) has gained favor in anticancer therapy, and can effectively prolong the survival of patients with cancer; however, numerous patients have PD-1/PD-L1 inhibitor primary resistance. The efficacy of anti-PD-1/PD-L1 therapy is related to the host tumor microenvironment. Radiation therapy can promote the body's antitumor immunity, change the tumor microenvironment, and synergize with anti-PD-1/PD-L1 treatment. Preclinical and clinical trials have shown that PD-1/PD-L1 inhibitor combined with radiotherapy has a significant effect. We review the synergistic antitumor mechanism and clinical trials of radiotherapy combined with anti-PD-1/PD-L1 therapy.

O-glycans on death receptors in cells modulate their sensitivity to TRAIL-induced apoptosis through affecting on their stability and oligomerization.

The TNF-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in cells by signaling through the O-glycosylated death receptors (DR4 and DR5), but the sensitivity to TRAIL-induced apoptosis of cells varies, and the attributes of this phenomenon are complex. Human carcinoma cells often express truncated O-glycans, Tn (GalNAcα1-Ser/Thr), and Sialyl-Tn (Siaα2-6GalNAcα1-Ser/Thr, STn) on their surface glycoproteins, yet molecular mechanisms in terms of advantages for tumor cells to have these truncated O-glycans remain elusive. Normal extended O-glycan biosynthesis is regulated by a specific molecular chaperone Cosmc through assisting of the correct folding of Core 1 β3 Galactosyltransferase (T-synthase). Here, we use tumor cell lines harboring mutations in Cosmc, and therefore expressing Tn and STn antigens to study the role of O-glycans in TRAIL-induced apoptosis. Expression of Tn and STn in tumor cells attenuates their sensitivity to TRAIL treatment; when transfected with wild-type Cosmc, these tumor cells thus express normal extended O-glycans and become more sensitive to TRAIL treatment. Mechanistically, Tn/STn antigens impair homo-oligomerization and stability of DR4 and DR5. These results represent the first mechanistic insight into how O-glycan structures on cell surface modulate their sensitivity to apoptotic stimuli, suggesting expression of Tn/STn may offer tumor cell survival advantages through altering DR4 and/or DR5 activity.

Incidence and Clinical Features of Immune-Related Acute Kidney Injury in Patients Receiving Programmed Cell Death Ligand-1 Inhibitors

BackgroundProgrammed cell death receptor ligand 1 (PD-L1) inhibitors are immune checkpoint inhibitors (ICIs) with a side effect profile that may differ from other classes of ICIs such as those directed against cytotoxic T-lymphocyte−associated protein 4 (CTLA-4) and programmed cell death 1 receptor (PD-1). Being the more recently approved class of checkpoint inhibitors, there are no studies investigating the frequency, etiology and predictors of acute kidney injury (AKI) in patients receiving PD-L1 inhibitors.MethodsThis was a retrospective cohort study of patients who received PD-L1 inhibitors during 2017 to 2018 in our healthcare system. AKI was defined by a ≥1.5-fold rise in serum creatinine from baseline. The etiology of all cases of sustained AKI (lasting >48 hours) and clinical course were determined by review of electronic health records.ResultsThe final analysis included 599 patients. Within 12 months of ICI initiation, 104 patients (17%) experienced AKI, and 36 (6%) experienced sustained AKI; however, only 5 (<1%) experienced suspected PD-L1–related AKI. The PD-L1–related AKI occurred a median of 99 days after starting therapy. All patients concurrently received another medication known to cause acute interstitial nephritis (proton pump inhibitors, nonsteroidal anti-inflammatory drugs, or antibiotics) at the time of the suspected PDL1-related AKI.ConclusionAlthough AKI is common in patients receiving PD-L1 therapy, the incidence of suspected PD-L1–related AKI is low (<1%) and may be less common when compared to other classes of ICIs. This cohort provides further validation that other drugs associated with acute interstitial nephritis may be involved in the pathogenesis of ICI-related AKI.

PD-L1 expression is an unfavourable prognostic indicator in Asian renal cell carcinomas

Background/aimsThe programmed cell death receptor 1 (PD-1) checkpoint inhibitor, nivolumab, has been approved for the treatment of metastatic renal cell carcinoma (RCC). However, the understanding of the expression and distribution...

Applying CRISPR/Cas13 to Construct Exosomal PD‐L1 Ultrasensitive Biosensors for Dynamic Monitoring of Tumor Progression in Immunotherapy

AbstractProgrammed cell death receptor 1 (PD‐L1) protein on exosomes (exosomal PD‐L1) is one of the most promising biomarkers for cancer immunotherapy monitoring. However, current approaches for exosomal PD‐L1 detection are poorly sensitive, laborious, and time‐consuming. Here, a new method, named Aptamer‐RPA‐TMA‐Cas13a Assay (ARTCA) is established, which enables exosomal PD‐L1 to be detected directly in serum with a lower limit of 10 particles mL−1. Mechanistically, using DNA aptamer specifically binding to exosomal PD‐L1, the aptamer is amplified twice by recombinase polymerase amplification (RPA) coupled with transcription‐mediated amplification (TMA) and simultaneously the TMA products are detected in real‐time with CRISPR/Cas13a system. Utilizing ARTCA, PD‐L1 levels in circulating exosomes seem to be a reliable marker of PD‐L1 expression in tumor tissue. The level of circulating exosomal PD‐L1 increases significantly in patients with tumor progression. Ultra‐trace detection of serum exosomal PD‐L1 by ARTCA provides a potentially convenient way for dynamic monitoring of tumor progression for patients undergoing immunotherapy. These results demonstrate the use of CRISPR‐Cas13a for protein detection, and circulating exosomal PD‐L1 levels seem to be a reliable marker as well as PD‐L1 expression in tumor tissue, opening up new avenues for monitoring tumor progression.