Thromboxane biosynthesis in cancer patients and its inhibition by aspirin: a sub-study of the Add-Aspirin trial.

BACKGROUND: Pre-clinical models demonstrate that platelet activation is involved in the spread of malignancy. Ongoing clinical trials are assessing whether aspirin, which inhibits platelet activation, can prevent or delay metastases. METHODS: Urinary 11-dehydro-thromboxane B2 (U-TXM), a biomarker of in vivo platelet activation, was measured after radical cancer therapy and correlated with patient demographics, tumour type, recent treatment, and aspirin use (100 mg, 300 mg or placebo daily) using multivariable linear regression models with log-transformed values. RESULTS: In total, 716 patients (breast 260, colorectal 192, gastro-oesophageal 53, prostate 211) median age 61 years, 50% male were studied. Baseline median U-TXM were breast 782; colorectal 1060; gastro-oesophageal 1675 and prostate 826 pg/mg creatinine; higher than healthy individuals (~500 pg/mg creatinine). Higher levels were associated with raised body mass index, inflammatory markers, and in the colorectal and gastro-oesophageal participants compared to breast participants (P < 0.001) independent of other baseline characteristics. Aspirin 100 mg daily decreased U-TXM similarly across all tumour types (median reductions: 77-82%). Aspirin 300 mg daily provided no additional suppression of U-TXM compared with 100 mg. CONCLUSIONS: Persistently increased thromboxane biosynthesis was detected after radical cancer therapy, particularly in colorectal and gastro-oesophageal patients. Thromboxane biosynthesis should be explored further as a biomarker of active malignancy and may identify patients likely to benefit from aspirin.

Type 2 Diabetes Mellitus and Efficacy Outcomes from Immune Checkpoint Blockade in Patients with Cancer.

PURPOSE: No evidence exists as to whether type 2 diabetes mellitus (T2DM) impairs clinical outcome from immune checkpoint inhibitors (ICI) in patients with solid tumors. EXPERIMENTAL DESIGN: In a large cohort of ICI recipients treated at 21 institutions from June 2014 to June 2020, we studied whether patients on glucose-lowering medications (GLM) for T2DM had shorter overall survival (OS) and progression-free survival (PFS). We used targeted transcriptomics in a subset of patients to explore differences in the tumor microenvironment (TME) of patients with or without diabetes. RESULTS: A total of 1,395 patients were included. Primary tumors included non-small cell lung cancer (NSCLC; 54.7%), melanoma (24.7%), renal cell (15.0%), and other carcinomas (5.6%). After multivariable analysis, patients on GLM (n = 226, 16.2%) displayed an increased risk of death [HR, 1.29; 95% confidence interval (CI),1.07-1.56] and disease progression/death (HR, 1.21; 95% CI, 1.03-1.43) independent of number of GLM received. We matched 92 metformin-exposed patients with 363 controls and 78 patients on other oral GLM or insulin with 299 control patients. Exposure to metformin, but not other GLM, was associated with an increased risk of death (HR, 1.53; 95% CI, 1.16-2.03) and disease progression/death (HR, 1.34; 95% CI, 1.04-1.72). Patients with T2DM with higher pretreatment glycemia had higher neutrophil-to-lymphocyte ratio (P = 0.04), while exploratory tumoral transcriptomic profiling in a subset of patients (n = 22) revealed differential regulation of innate and adaptive immune pathways in patients with T2DM. CONCLUSIONS: In this study, patients on GLM experienced worse outcomes from immunotherapy, independent of baseline features. Prospective studies are warranted to clarify the relative impact of metformin over a preexisting diagnosis of T2DM in influencing poorer outcomes in this population.

No evidence that HLA genotype influences the driver mutations that occur in cancer patients.

The major histocompatibility (MHC) molecules are capable of presenting neoantigens resulting from somatic mutations on cell surfaces, potentially directing immune responses against cancer. This led to the hypothesis that cancer driver mutations may occur in gaps in the capacity to present neoantigens that are dependent on MHC genotype. If this is correct, it has important implications for understanding oncogenesis and may help to predict driver mutations based on genotype data. In support of this hypothesis, it has been reported that driver mutations that occur frequently tend to be poorly presented by common MHC alleles and that the capacity of a patient's MHC alleles to present the resulting neoantigens is predictive of the driver mutations that are observed in their tumor. Here we show that these reports of a strong relationship between driver mutation occurrence and patient MHC alleles are a consequence of unjustified statistical assumptions. Our reanalysis of the data provides no evidence of an effect of MHC genotype on the oncogenic mutation landscape.

Selective expansion of chimeric antigen receptor-targeted T-cells with potent effector function using interleukin-4.

Polyclonal T-cells can be directed against cancer using transmembrane fusion molecules known as chimeric antigen receptors (CARs). Although preclinical studies have provided encouragement, pioneering clinical trials using CAR-based immunotherapy have been disappointing. Key obstacles are the need for robust expansion ex vivo followed by sustained survival of infused T-cells in patients. To address this, we have developed a system to achieve selective proliferation of CAR(+) T-cells using IL-4, a cytokine with several pathophysiologic and therapeutic links to cancer. A chimeric cytokine receptor (4alphabeta) was engineered by fusion of the IL-4 receptor alpha (IL-4Ralpha) ectodomain to the beta(c) subunit, used by IL-2 and IL-15. Addition of IL-4 to T-cells that express 4alphabeta resulted in STAT3/STAT5/ERK phosphorylation and exponential proliferation, mimicking the actions of IL-2. Using receptor-selective IL-4 muteins, partnering of 4alphabeta with gamma(c) was implicated in signal delivery. Next, human T-cells were engineered to co-express 4alphabeta with a CAR specific for tumor-associated MUC1. These T-cells exhibited an unprecedented capacity to elicit repeated destruction of MUC1-expressing tumor cultures and expanded through several logs in vitro. Despite prolonged culture in IL-4, T-cells retained specificity for target antigen, type 1 polarity, and cytokine dependence. Similar findings were observed using CARs directed against two additional tumor-associated targets, demonstrating generality of application. Furthermore, this system allows rapid ex vivo expansion and enrichment of engineered T-cells from small blood volumes, under GMP-compliant conditions. Together, these findings provide proof of principle for the development of IL-4-enhanced T-cell immunotherapy of cancer.

The breast proto-oncogene, HRGalpha regulates epithelial proliferation and lobuloalveolar development in the mouse mammary gland.

Members of the EGF family of growth factors play critical roles during normal and neoplastic breast development. EGF family member HRGalpha is the only HRG1 isoform expressed in the mouse mammary gland and our previous experiments suggest that HRG1 has a unique role in mammary development. To determine the function of HRGalpha activity during mouse mammary gland development, we generated a HRGalpha-deficient mouse strain. Unlike mice with HRG1 or isoform specific HRGbeta gene deletions, HRGalpha-null mice survive to adulthood. HRGalpha-deficient mice display pronounced defects in mammary gland lobuloalveolar development at 17 days of pregnancy and 3 days post-partum. Terminal and lateral ductal alveoli were condensed and alveolar outgrowth during pregnancy was severely impaired. A dramatic reduction in beta-casein expression accompanied defective alveolar development in the HRGalpha-null mice, as determined by in situ hybridization and Northern blot analysis of HRGalpha-deficient mammary glands at 3 days post-partum. Expression of the milk-protein genes WAP and alpha-lactalbumin was not adversely affected. In situ incorporation of BrdU demonstrated that epithelial proliferation was significantly curtailed in mammary glands of HRGalpha-deficient mice at 17 days post-coitus and 3 days post-partum. These results demonstrate that HRGalpha is an important mammary gland mitogen regulating alveolar development and lactogenesis.