An IRAK1-PIN1 signalling axis drives intrinsic tumour resistance to radiation therapy

Drug-based strategies to overcome tumour resistance to radiotherapy (R-RT) remain limited by the single-agent toxicity of traditional radiosensitizers (for example, platinums) and a lack of targeted alternatives. In a screen for compounds that restore radiosensitivity in p53 mutant zebrafish while tolerated in non-irradiated wild-type animals, we identified the benzimidazole anthelmintic oxfendazole. Surprisingly, oxfendazole acts via the inhibition of IRAK1, a kinase thus far implicated in interleukin-1 receptor (IL-1R) and Toll-like receptor (TLR) immune responses. IRAK1 drives R-RT in a pathway involving IRAK4 and TRAF6 but not the IL-1R/TLR-IRAK adaptor MyD88. Rather than stimulating nuclear factor-κB, radiation-activated IRAK1 prevented apoptosis mediated by the PIDDosome complex (comprising PIDD, RAIDD and caspase-2). Countering this pathway with IRAK1 inhibitors suppressed R-RT in tumour models derived from cancers in which TP53 mutations predict R-RT. Moreover, IRAK1 inhibitors synergized with inhibitors of PIN1, a prolyl isomerase essential for IRAK1 activation in response to pathogens and, as shown here, in response to ionizing radiation. These data identify an IRAK1 radiation-response pathway as a rational chemoradiation therapy target

ULK1 inhibition overcomes compromised antigen presentation and restores antitumor immunity in LKB1-mutant lung cancer

Inactivating mutations in LKB1/STK11 are present in roughly 20% of nonsmall cell lung cancers (NSCLC) and portend poor response to anti-PD-1 immunotherapy. Unexpectedly, we found that LKB1 deficiency correlated with elevated tumor mutational burden (TMB) in NSCLCs from nonsmokers and genetically engineered mouse models, despite the frequent association between high-TMB and anti-PD-1 treatment efficacy. However, LKB1 deficiency also suppressed antigen processing and presentation, which are associated with compromised immunoproteasome activity and increased autophagic flux. Immunoproteasome activity and antigen presentation were restored by inhibiting autophagy through targeting the ATG1/ULK1 pathway. Accordingly, ULK1 inhibition synergized with PD-1 antibody blockade, provoking effector T-cell expansion and tumor regression in Lkb1-mutant tumor models. This study reveals an interplay between the immunoproteasome and autophagic catabolism in antigen processing and immune recognition, and proposes the therapeutic potential of dual ULK1 and PD-1 inhibition in LKB1-mutant NSCLC as a strategy to enhance antigen presentation and to promote antitumor immunity

Major Pathologic Response and Prognostic Score Predict Survival in Patients With Lung Cancer Receiving Neoadjuvant Chemotherapy.

Complete pathologic response (CPR) is an acceptable surrogate for survival in clinical trials but it occurs infrequently in patients with NSCLC receiving neoadjuvant chemotherapy (NCT). Therefore, we studied the impact of major pathologic response (MPR) for predicting survival of patients with NSCLC receiving NCT. We also tested a newly reported scoring system-the prognostic score (PRSC)-which combines T category, lymph node status, and MPR status. We analyzed CPR and MPR, defined as 0% and less than or equal to 10% viable tumor cells, respectively, in 339 patients with NSCLC with various histologic types who had been treated with NCT followed by complete surgical resection. We evaluated the relationships between CPR, MPR, or PRSC and overall survival using the Kaplan-Meier method and Cox regression multivariate models, accounting for known prognostic factors, such as age, gender, histologic subtype, and pathologic stage. Among all 339 patients, the Kaplan-Meier method revealed that patients with CPR and MPR had better survival. MPR identified a favorable group of patients who experienced survival similar to patients with CPR. Nevertheless, patients with no MPR had a significantly reduced probability of survival. Furthermore, univariate and multivariate Cox proportional hazards regression analysis revealed that MPR and PRSC were significantly associated with overall survival. Our data suggest that MPR can be used as an end point for overall survival in different histologic types for evaluation of therapeutic agents in clinical trials exploring NCT. We also confirmed that PRSC had a prognostic impact, differentiating patients into three prognostic groups, but not superior compared with MPR alone or the TNM8 systems

Validation of a standardized method for enumerating circulating endothelial cells and progenitors: flow cytometry and molecular and ultrastructural analyses

Purpose: Antigenic overlap among circulating endothelial cells (CEC) and progenitors (CEP), platelets, and other blood cells led to the need to develop a reliable standardized method for CEC and CEP quantification. These cells are emerging as promising preclinical/clinical tools to define optimal biological doses of antiangiogenic therapies and to help stratify patients in clinical trials. Experimental Design: We report the experimental validation of a novel flow cytometry method that precisely dissects CEC/CEP from platelets and other cell populations and provides information about CEC/CEP viability. Results: Sorted DNA/Syto16 +CD45 -CD31 +CD146 + CECs, investigated by electron microscopy, were found to be bona fide endothelial cells by the presence of Weibel-Palade bodies. More than 75% of the circulating mRNAs of the endothelial-specific gene, VE-cadherin, found in the blood were present in the sorted population. CECs were 140 \ub1 171/mL in healthy subjects (n = 37) and 951 \ub1 1,876/mL in cancer patients (n - 78; P \uab 0.0001). The fraction of apoptotic/necrotic CECs was 77 \ub1 14% in healthy subjects and 43 \ub1 23% in cancer patients (P \uab 0.0001). CEPs were 181 \ub1 167/mL in healthy donors and 429 \ub1 507/mL in patients (P = 0.00019). Coefficients of variation were 4 \ub1 4% (intrareader), 17 \ub1 4% (interreader), and 17 \ub1 7% (variability over 0-72 h), respectively. Parallel samples were frozen by a standardized protocol. After thawing, coefficients of variation were 12 \ub1 8% (intrareader), 16 \ub1 10% (interreader), and 26 \ub1 16% (variability over 0-14 days of frozen storage), respectively. Conclusions: This procedure enumerates a truly endothelial cell population with limited intrareader and interreader variability. It appears possible to freeze samples for large-scale CEC enumeration during clinical trials. This approach could be enlarged to investigate other angiogenic cell populations as well

Intratumor heterogeneity in localized lung adenocarcinomas delineated by multiregion sequencing

Cancers are composed of populations of cells with distinct molecular and phenotypic features, a phenomenon termed intra-tumor heterogeneity (ITH). ITH in lung cancers has not been well studied. We applied multi-region whole exome sequencing (WES) on 11 localized lung adenocarcinomas. All tumors showed clear evidence of ITH. On average, 76% of all mutations and 20/21 known cancer gene mutations were identified in all regions of individual tumors suggesting single-region sequencing may be adequate to identify the majority of known cancer gene mutations in localized lung adenocarcinomas. With a median follow-up of 21 months post-surgery, 3 patients have relapsed and all 3 patients had significantly larger fractions of subclonal mutations in their primary tumors than patients without relapse. These data indicate larger subclonal mutation fraction may be associated with increased likelihood of postsurgical relapse in patients with localized lung adenocarcinomas