BAP1 and YY1 regulate expression of death receptors in malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a rare, aggressive, and incurable cancer arising from the mesothelial lining of the pleura, with few available treatment options. We recently reported that loss of function of the nuclear deubiquitinase BRCA1-associated protein 1 (BAP1), a frequent event in MPM, is associated with sensitivity to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. As a potential underlying mechanism, here we report that BAP1 negatively regulates the expression of TRAIL receptors: death receptor 4 (DR4) and death receptor 5 (DR5). Using tissue microarrays of tumor samples from MPM patients, we found a strong inverse correlation between BAP1 and TRAIL receptor expression. BAP1 knockdown increased DR4 and DR5 expression, whereas overexpression of BAP1 had the opposite effect. Reporter assays confirmed wt-BAP1, but not catalytically inactive BAP1 mutant, reduced promoter activities of DR4 and DR5, suggesting deubiquitinase activity is required for the regulation of gene expression. Co-immunoprecipitation studies demonstrated direct binding of BAP1 to the transcription factor Ying Yang 1 (YY1), and chromatin immunoprecipitation assays revealed BAP1 and YY1 to be enriched in the promoter regions of DR4 and DR5. Knockdown of YY1 also increased DR4 and DR5 expression and sensitivity to TRAIL. These results suggest that BAP1 and YY1 cooperatively repress transcription of TRAIL receptors. Our finding that BAP1 directly regulates the extrinsic apoptotic pathway will provide new insights into the role of BAP1 in the development of MPM and other cancers with frequent BAP1 mutations.

Acute Immune Signatures and Their Legacies in Severe Acute Respiratory Syndrome Coronavirus-2 Infected Cancer Patients.

Given the immune system's importance for cancer surveillance and treatment, we have investigated how it may be affected by SARS-CoV-2 infection of cancer patients. Across some heterogeneity in tumor type, stage, and treatment, virus-exposed solid cancer patients display a dominant impact of SARS-CoV-2, apparent from the resemblance of their immune signatures to those for COVID-19+ non-cancer patients. This is not the case for hematological malignancies, with virus-exposed patients collectively displaying heterogeneous humoral responses, an exhausted T cell phenotype and a high prevalence of prolonged virus shedding. Furthermore, while recovered solid cancer patients' immunophenotypes resemble those of non-virus-exposed cancer patients, recovered hematological cancer patients display distinct, lingering immunological legacies. Thus, while solid cancer patients, including those with advanced disease, seem no more at risk of SARS-CoV-2-associated immune dysregulation than the general population, hematological cancer patients show complex immunological consequences of SARS-CoV-2 exposure that might usefully inform their care.

Beyond chemoradiotherapy: improving treatment outcomes for patients with stage III unresectable non-small-cell lung cancer through immuno-oncology and durvalumab (Imfinzi®â–¼, AstraZeneca UK Limited).

The treatment paradigm of non-small-cell lung cancer (NSCLC) has rapidly changed in recent years following the introduction of immune-checkpoint inhibition (ICI). Pre-clinically, both chemotherapy and radiotherapy modulate the tumour microenvironment, providing the rationale for clinical trials evaluating their role in combination with immunotherapy. Standard-of-care treatment for patients with unresectable stage III disease is concurrent chemoradiotherapy (cCRT); however, only recently, the combination with ICI has been explored. The Phase 3 PACIFIC study randomised 713 patients with confirmed locally advanced, unresectable, stage III NSCLC, whose disease has not progressed following cCRT, to either the anti-programmed death-ligand 1 (PD-L1) agent durvalumab (Imfinzi®â–¼, AstraZeneca UK Limited) or placebo. Patients with a PD-L1 status ≥1% treated with durvalumab had a significantly longer median progression-free survival compared with placebo (17.2 vs. 5.6 months, respectively; HR: 0.51; 95% CI: 0.41-0.63), prolonged median overall survival (OS) (NR vs. 28.7 months, respectively; HR: 0.68; 99.73% CI: 0.47-0.997; P = 0.0025) and long-term clinical benefit (3-year OS HR: 0.69; 95% CI: 0.55-0.86). Grade 3 or 4 toxicity was marginally greater in the durvalumab cohort versus placebo (30.5% vs. 26.1%). Based on these results, durvalumab has been licensed in this setting, and further clinical trials are exploring the use of ICI in unresectable stage III NSCLC.

Retrospective response analysis of BAP1 expression to predict the clinical activity of systemic cytotoxic chemotherapy in mesothelioma.

Introduction BRCA1 associated protein-1 (BAP1) is a key tumor driver in mesothelioma and a potential biomarker predicting response to several targeted therapies in clinical testing. Whether it also modulates response to cytotoxic chemotherapy is undetermined. This study used retrospective response analysis of BAP1 expression in archival tumor biopsies taken from patients in the MS01 trial (NCT00075699). We aimed to determine if BAP1 expression correlated with overall survival within the three treatment arms in this trial, namely active symptom control (ASC); ASC plus mitomycin, vinblastine and cisplatin (MVP); and ASC plus vinorelbine. Materials and methods We used immunohistochemical analysis of tumor samples from the MS01 trial to identify subgroups with and without nuclear BAP1 expression. We performed correlative analysis of clinical characteristics (age at diagnosis, sex and histological subtype) and overall survival within treatment arms with nuclear BAP1 expression. Results 89 tumor samples from the 409 patients originally in the trial were available for analysis. Of these, 60 samples harbored a positive internal control, in the form of positive staining of inflammatory cells for BAP1, and were carried forward for analysis. Correlative analysis suggested no significant association between loss of nuclear BAP1 expression and age at diagnosis, sex and histological subtype. Kaplan Meier survival analysis revealed a small, though non-significant, overall survival disadvantage associated with BAP1 expression in tumors from patients treated with vinorelbine. Discussion This exploratory analysis suggests BAP1 expression may modify response to vinorelbine in MPM, possibly due to prevention of mitotic microtubule formation. We suggest ongoing and planned clinical studies of vinorelbine in MPM assess BAP1 expression as a predictive biomarker of response.

Loss of functional BAP1 augments sensitivity to TRAIL in cancer cells.

Malignant mesothelioma (MM) is poorly responsive to systemic cytotoxic chemotherapy and invariably fatal. Here we describe a screen of 94 drugs in 15 exome-sequenced MM lines and the discovery of a subset defined by loss of function of the nuclear deubiquitinase BRCA associated protein-1 (BAP1) that demonstrate heightened sensitivity to TRAIL (tumour necrosis factor-related apoptosis-inducing ligand). This association is observed across human early passage MM cultures, mouse xenografts and human tumour explants. We demonstrate that BAP1 deubiquitinase activity and its association with ASXL1 to form the Polycomb repressive deubiquitinase complex (PR-DUB) impacts TRAIL sensitivity implicating transcriptional modulation as an underlying mechanism. Death receptor agonists are well-tolerated anti-cancer agents demonstrating limited therapeutic benefit in trials without a targeting biomarker. We identify BAP1 loss-of-function mutations, which are frequent in MM, as a potential genomic stratification tool for TRAIL sensitivity with immediate and actionable therapeutic implications.

Ki-67 index and response to chemotherapy in patients with neuroendocrine tumours.

Chemotherapy (CT) is widely used for neuroendocrine tumours (NETs), but there are no validated biomarkers to predict response. The Ki-67 proliferation index has been proposed as a means of selecting patients for CT, but robust data are lacking. The aim of this study was to investigate the relationship between response to chemotherapy and Ki-67 in NET. We reviewed data from 222 NET patients treated with CT. Tumours were graded according to Ki-67 index: G1 ≤2%, G2 3-20% and G3 >20%. Response was assessed according to RECIST and survival calculated from start of chemotherapy to death. To explore Ki-67 as a marker of response, we calculated the likelihood ratio and performed receiver operating characteristic analysis. Overall, 193 patients had a documented Ki-67 index, of which 173 were also evaluable for radiological response: 10% were G1, 46% G2 and 43% G3; 46% were pancreatic NET (PNET). Median overall survival was 22.1 months. Overall response rate was 30% (39% in PNET vs 22% in non-PNET) and 43% of patients had stable disease. Response rate increased with grade: 6% in G1 tumours, 24% in G2 and 43% in G3. However, maximum likelihood ratio was 2.3 at Ki-67=35%, and the area under the ROC curve was 0.60. As reported previously, a high Ki-67 was an adverse prognostic factor for overall survival. In conclusion, response to CT increases with Ki-67 index, but Ki-67 alone is an unreliable means to select patients for CT. Improved methods to stratify patients for systemic therapy are required.

Prospects for adoptive immunotherapy of pancreatic cancer using chimeric antigen receptor-engineered T-cells.

Adoptive immunotherapy using chimeric antigen receptor (CAR) engineered T-cells is emerging as a powerful new approach to cancer immunotherapy. CARs are fusion molecules that couple the antibody-like binding of a native cell surface target to the delivery of a bespoke T-cell activating signal. Recent studies undertaken by several centers have demonstrated highly compelling efficacy in patients with acute and chronic B-cell malignancies. However, comparable therapeutic activity has not been achieved in solid tumors. Modern management of pancreatic ductal adenocarcinoma (PDAC) remains ineffective, reflected in the virtual equivalence of annual incidence and mortality statistics for this tumor type. Increasing evidence indicates that these tumors are recognized by the immune system, but deploy powerful evasion strategies that limit natural immune surveillance and render efforts at immunotherapy challenging. Here, we review preclinical and clinical studies that have been initiated or completed in an effort to develop CAR-based immunotherapy for PDAC. We also consider the hurdles to the effective clinical development of this exciting new therapeutic modality.

MLN8237 ( alisertib ) and its role in peripheral T-cell lymphoma.

INTRODUCTION: Peripheral T-cell lymphomas (PTCL) are a diverse group of rare non-Hodgkin lymphomas (NHL) that carry a poor prognosis and are in need of effective therapies. A greater understanding of how these tumours proliferate as well as how best to exploit these processes should lead to more durable tumour regression and better clinical outcomes for patients. New approaches include the histone deacetylase inhibitors, antifolates, fusion proteins, nucleoside analogues and agents targeting the immune system, which are being investigated either as single agents or as a combination. AREAS COVERED: The authors review the evidence for the orally administered aurora A kinase inhibitor MLN8237 ( alisertib ) in T-cell lymphoma. No significant association between clinical response and AAK expression has been observed but inhibition of this enzyme in a Phase II study has demonstrated tumour regression in 27% of heavily pretreated B- and T-cell NHL, with 50% of PTCL patients responding and 3 of 4 patients achieving durable responses. EXPERT OPINION: A Phase III trial in relapsed PTCL is recruiting patients comparing MLN8237 against single agent comparators. With regards to the data; the response rate of MLN8237 in refractory NHL is promising. The authors believe that further preclinical work identifying the best combinations to take through into clinical trials is important, particularly as this agent is used in earlier lines of therapy.

A rare case of squamous cell carcinoma of the lung harbouring ALK and BRAF activating mutations.

The management of non-small cell lung cancer has significantly changed over the past few years through greater understanding of tumour biology. The identification of activating mutations has led to the development of targeted agents. Coexisting mutations in non-small cell lung cancer is uncommon, particularly in squamous cell carcinoma. Our case represents a late gentleman with squamous cell carcinoma of the lung with both a BRAF mutation and ALK rearrangement prior to treatment.