Publications

Treatments for high-grade serous ovarian cancer (HGSOC) are initially effective but most invariably fail. Although they can successfully suppress the bulk of the tumour cell population, residual cancer cells can enter alternative therapy-resistant cell fates highlighted by proliferative arrest. Understanding the nature of these fates and how cells may resume uncontrolled proliferation will lead to the development of new treatments for HGSOC. In this study, we examine the response of HGSOC cells to standard of care cisplatin chemotherapy and to the RNA Polymerase I transcription inhibitor CX-5461/Pidnarulex, two drugs that elicit a potent DNA damage response and growth arrest. Here, we identify that HGSOC cells exposed to these therapies show multiple hallmarks of therapy-induced senescence (TIS) and derive a core TIS gene expression signature irrespective of genetic background or senescence trigger. Given that TIS is a potentially escapable state, we have performed a focussed drug screen to identify drugs that eradicate senescent HGSOC cells. We identify that therapy-induced senescent HGSOC cells, including those with decreased sensitivity to senolytic drugs that inhibit the pro-survival protein BCL-XL, can be eliminated using drugs that induce ferroptosis, an iron-dependent form of cell death. Mechanistically, we demonstrate that senescent HGSOC cells have altered expression of regulators of iron metabolism leading to intracellular iron overload that underpins this targetable vulnerability. Together, we highlight elevated levels of iron as a TIS biomarker in HGSOC and the potential of inducing ferroptosis to eradicate residual HGSOC cells following initial therapy.

In a phase I study of autologous chimeric antigen receptor (CAR) anti-LeY T-cell therapy of acute myeloid leukemia (AML), we examined the safety and postinfusion persistence of adoptively transferred T cells. Following fludarabine-containing preconditioning, four patients received up to 1.3 × 109 total T cells, of which 14–38% expressed the CAR. Grade 3 or 4 toxicity was not observed. One patient achieved a cytogenetic remission whereas another with active leukemia had a reduction in peripheral blood (PB) blasts and a third showed a protracted remission. Using an aliquot of In111-labeled CAR T cells, we demonstrated trafficking to the bone marrow (BM) in those patients with the greatest clinical benefit. Furthermore, in a patient with leukemia cutis, CAR T cells infiltrated proven sites of disease. Serial PCR of PB and BM for the LeY transgene demonstrated that infused CAR T cells persisted for up to 10 months. Our study supports the feasibility and safety of CAR–T-cell therapy in high-risk AML, and demonstrates durable in vivo ­persistence. In a phase I study of autologous chimeric antigen receptor (CAR) anti-LeY T-cell therapy of acute myeloid leukemia (AML), we examined the safety and postinfusion persistence of adoptively transferred T cells. Following fludarabine-containing preconditioning, four patients received up to 1.3 × 109 total T cells, of which 14–38% expressed the CAR. Grade 3 or 4 toxicity was not observed. One patient achieved a cytogenetic remission whereas another with active leukemia had a reduction in peripheral blood (PB) blasts and a third showed a protracted remission. Using an aliquot of In111-labeled CAR T cells, we demonstrated trafficking to the bone marrow (BM) in those patients with the greatest clinical benefit. Furthermore, in a patient with leukemia cutis, CAR T cells infiltrated proven sites of disease. Serial PCR of PB and BM for the LeY transgene demonstrated that infused CAR T cells persisted for up to 10 months. Our study supports the feasibility and safety of CAR–T-cell therapy in high-risk AML, and demonstrates durable in vivo ­persistence.

Abstract Exquisite regulation of PI3K/AKT/mTORC1 signaling is essential for homeostatic control of cell growth, proliferation, and survival. Aberrant activation of this signaling network is an early driver of many sporadic human cancers. Paradoxically, sustained hyperactivation of the PI3K/AKT/mTORC1 pathway in nontransformed cells results in cellular senescence, which is a tumor-suppressive mechanism that must be overcome to promote malignant transformation. While oncogene-induced senescence (OIS) driven by excessive RAS/ERK signaling has been well studied, little is known about the mechanisms underpinning the AKT-induced senescence (AIS) response. Here, we utilize a combination of transcriptome and metabolic profiling to identify key signatures required to maintain AIS. We also employ a whole protein-coding genome RNAi screen for AIS escape, validating a subset of novel mediators and demonstrating their preferential specificity for AIS as compared with OIS. As proof of concept of the potential to exploit the AIS network, we show that neurofibromin 1 (NF1) is upregulated during AIS and its ability to suppress RAS/ERK signaling facilitates AIS maintenance. Furthermore, depletion of NF1 enhances transformation of p53-mutant epithelial cells expressing activated AKT, while its overexpression blocks transformation by inducing a senescent-like phenotype. Together, our findings reveal novel mechanistic insights into the control of AIS and identify putative senescence regulators that can potentially be targeted, with implications for new therapeutic options to treat PI3K/AKT/mTORC1-driven cancers.

<p>Fig S1: Generation and characterisation of an androgen-dependent Hi-MYC epithelial line from 5-month Hi-MYC lateral prostate adenocarcinoma. Fig S2: CX-6258 does not inhibit Ribosomal RNA transcription. Fig S3: CX-6258 does not induce p53, but does induce low level p21 expression Fig S4: CX-5461 co-operates with Everolimus (RAD001) in vitro, but this does not suppress Hi-MYC tumorigenesis Fig S5: 5 month old Hi-MYC mouse prostate and body weight Fig S6: Influence of the androgen receptor on growth inhibition sensitivity</p>

Abstract Purpose: Figitumumab is a human IgG2 monoclonal antibody targeting insulin-like growth factor 1 receptor (IGF-1R), with antitumor activity in prostate cancer. This phase II trial randomized chemotherapy-naïve men with progressing castration-resistant prostate cancer to receive figitumumab every 3 weeks with docetaxel/prednisone (Arm A) or docetaxel/prednisone alone (Arm B1). At progression on Arm B1, patients could cross over to the combination (Arm B2). Experimental Design: Prostate-specific antigen (PSA) response was the primary endpoint; response assessment on the two arms was noncomparative and tested separately; H0 = 0.45 versus HA = 0.60 (α = 0.05; β = 0.09) for Arm A; H0 = 0.05 versus HA = 0.20 (α = 0.05, β = 0.10) for Arm B2. A comparison of progression-free survival (PFS) on Arms A and B1 was planned. Results: A total of 204 patients were randomized and 199 treated (Arm A: 97; Arm B1: 102); 37 patients crossed over to Arm B2 (median number of cycles started: Arm A = 8; B1 = 8; B2 = 4). PSA responses occurred in 52% and 60% of Arms A and B1, respectively; the primary PSA response objective in Arm A was not met. Median PFS was 4.9 and 7.9 months, respectively (HR = 1.44; 95% confidence interval, 1.06–1.96). PSA response rate was 28% in Arm B2. The figitumumab combination appeared more toxic, with more treatment-related grade 3/4 adverse events (75% vs. 56%), particularly hyperglycemia, diarrhea, and asthenia, as well as treatment-related serious adverse events (41% vs. 15%), and all-causality grade 5 adverse events (18% vs. 8%). Conclusion: IGF-1R targeting may merit further evaluation in this disease in selected populations, but combination with docetaxel is not recommended. Clin Cancer Res; 20(7); 1925–34. ©2014 AACR.

<p>Supplementary Figure 8. Proposed mechanisms and clinical application for the ACTIV+Pano treatment.</p>

Objective The prevalence of drug-resistant Mycobacterium tuberculosis (Mtb) strains is exacerbating the global burden of tuberculosis (TB), highlighting the urgent need for new treatment strategies for TB. Methods The recombinant adenovirus vaccine expressing cyclic di-adenosine monophosphate (c-di-AMP) phosphodiesterase B (CnpB) (rAd-CnpB), was administered to normal mice via mucosal immunization, either alone or in combination with drug therapy, to treat Mtb respiratory infections in mice.Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of antibodies in serum and bronchoalveolar lavage fluid (BALF). Real-time quantitative PCR was performed to assess the transcription levels of cytokines interferon γ(IFN-γ) and interleukin 10(IL-10) in mouse lungs. Flow cytometry was used to determine the proportions of CD4

Immune checkpoint inhibitors (ICIs) have transformed cancer treatment, but ICI myocarditis (ICI-M) remains a potentially fatal complication. The clinical implications and predictors of left ventricular ejection fraction (LVEF) <50% in ICI-M are not well understood. The aim of this study was to identify factors associated with LVEF <50% vs ≥50% at the time of hospitalization for ICI-M. A secondary objective was to evaluate the relationship between LVEF and 30-day all-cause mortality. The International ICI-Myocarditis Registry, a retrospective, international, multicenter database, included 757 patients hospitalized with ICI-M. Patients were stratified by LVEF as reduced LVEF (<50%) or preserved LVEF (≥50%) on admission. Cox proportional hazards models were used to assess the associations between LVEF and clinical events, and multivariable logistic regression was conducted to examine factors linked to LVEF. Of 757 patients, 707 had documented LVEFs on admission: 244 (35%) with LVEF <50% and 463 (65%) with LVEF ≥50%. Compared with patients with LVEF ≥50%, those with LVEF <50% were younger (<70 years), had a body mass index of <25 kg/m2, and were more likely to have received chest radiation (24.2% vs 13.5%; P < 0.001). Multivariable analysis identified predictors of LVEF <50%, including exposure to v-raf murine sarcoma viral oncogene homolog B1/mitogen-activated protein kinase inhibitors, pre-existing heart failure, dyspnea at presentation, and at least 40 days from ICI initiation to ICI-M onset. Conversely, myositis symptoms were associated with LVEF ≥50%. LVEF <50% was marginally associated with 30-day all-cause mortality (unadjusted log-rank P = 0.062; adjusted for age, cancer types, and ICI therapy, HR: 1.50; 95% CI: 1.02-2.20). Dyspnea, time from ICI initiation, a history of heart failure, and prior cardiotoxic therapy may be predictors of an initial LVEF <50% in patients with ICI-M.