Utility of a Telephone Triage Hotline in Response to the COVID-19 Pandemic: Longitudinal Observational Study.

BACKGROUND: During the initial months of the COVID-19 pandemic, rapidly rising disease prevalence in the United States created a demand for patient-facing information exchanges that addressed questions and concerns about the disease. One approach to managing increased patient volumes during a pandemic involves the implementation of telephone-based triage systems. During a pandemic, telephone triage hotlines can be employed in innovative ways to conserve medical resources and offer useful population-level data about disease symptomatology and risk factor profiles. OBJECTIVE: The aim of this study is to describe and evaluate the COVID-19 telephone triage hotline used by a large academic medical center in the midwestern United States. METHODS: Michigan Medicine established a telephone hotline to triage inbound patient calls related to COVID-19. For calls received between March 24, 2020, and May 5, 2020, we described total call volume, data reported by callers including COVID-19 risk factors and symptomatology, and distribution of callers to triage algorithm endpoints. We also described symptomatology reported by callers who were directed to the institutional patient portal (online medical visit questionnaire). RESULTS: A total of 3929 calls (average 91 calls per day) were received by the call center during the study period. The maximum total number of daily calls peaked at 211 on March 24, 2020. Call volumes were the highest from 6 AM to 11 AM and during evening hours. Callers were most often directed to the online patient portal (1654/3929, 42%), nursing hotlines (1338/3929, 34%), or employee health services (709/3929, 18%). Cough (126/370 of callers, 34%), shortness of breath (101/370, 27%), upper respiratory infection (28/111, 25%), and fever (89/370, 24%) were the most commonly reported symptoms. Immunocompromised state (23/370, 6%) and age >65 years (18/370, 5%) were the most commonly reported risk factors. CONCLUSIONS: The triage algorithm successfully diverted low-risk patients to suitable algorithm endpoints, while directing high-risk patients onward for immediate assessment. Data collected from hotline calls also enhanced knowledge of symptoms and risk factors that typified community members, demonstrating that pandemic hotlines can aid in the clinical characterization of novel diseases.

Combinatorial Efficacy of Olaparib with Radiation and ATR Inhibitor Requires PARP1 Protein in Homologous Recombination-Proficient Pancreatic Cancer.

PARP inhibitor monotherapy (olaparib) was recently FDA approved for the treatment of BRCA1/2-mutant, homologous recombination (HR) repair-deficient pancreatic cancer. Most pancreatic cancers, however, are HR proficient and thus resistant to PARP inhibitor monotherapy. We tested the hypothesis that combined therapy with radiation and ataxia telangiectasia and Rad3-related (ATR) inhibitor (AZD6738) would extend the therapeutic indication of olaparib to HR-proficient pancreatic cancers. We show that olaparib combined with AZD6738 significantly reduced radiation survival relative to either agent alone, regardless of HR status. Whereas catalytic inhibition of PARP with low concentrations of olaparib radiosensitized HR-deficient models, maximal sensitization in HR-proficient models required concentrations of olaparib that induce formation of PARP1-DNA complexes. Furthermore, CRISPR-Cas9-mediated PARP1 deletion failed to recapitulate the effects of olaparib on radiosensitivity and negated the combinatorial efficacy of olaparib and AZD6738 on radiosensitization, suggesting that PARP1-DNA complexes, rather than PARP catalytic inhibition, were responsible for radiosensitization. Mechanistically, therapeutic concentrations of olaparib in combination with radiation and AZD6738 increased DNA double-strand breaks. DNA fiber combing revealed that high concentrations of olaparib did not stall replication forks but instead accelerated replication fork progression in association with an ATR-mediated replication stress response that was antagonized by AZD6738. Finally, in HR-proficient tumor xenografts, the combination of olaparib, radiation, and AZD6738 significantly delayed tumor growth compared with all other treatments. These findings suggest that PARP1-DNA complexes are required for the therapeutic activity of olaparib combined with radiation and ATR inhibitor in HR-proficient pancreatic cancer and support the clinical development of this combination for tumors intrinsically resistant to PARP inhibitors.

UAE1 inhibition mediates the unfolded protein response, DNA damage and caspase-dependent cell death in pancreatic cancer.

The Unfolded Protein Response (UPR) plays a key role in the adaptive response to loss of protein homeostasis within the endoplasmic reticulum (ER). The UPR has an adaptive function in protein homeostasis, however, sustained activation of the UPR due to hypoxia, nutrient deprivation, and increased demand for protein synthesis, alters the UPR program such that additional perturbation of ER homeostasis activates a pro-apoptotic program. Since ubiquitination followed by proteasomal degradation of misfolded proteins within the ER is a central mechanism for restoration of ER homeostasis, inhibitors of this pathway have proven to be valuable anti-cancer therapeutics. Ubiquitin activating enzyme 1(UAE1), activates ubiquitin for transfer to target proteins for proteasomal degradation in conjunction with E2 and E3 enzymes. Inhibition of UAE1 activity in response to TAK-243, leads to an accumulation of misfolded proteins within the ER, thereby aggravating ER stress, leading to DNA damage and arrest of cells in the G2/M phase of the cell cycle. Persistent drug treatment mediates a robust induction of apoptosis following a transient cell cycle arrest. These biological effects of TAK-243 were recapitulated in mouse models of PDAC demonstrating antitumor activity at a dose and schedule that did not exhibit obvious normal tissue toxicity. In vitro as well as studies in mouse models failed to show enhanced efficacy when TAK-243 was combined with ionizing radiation or gemcitabine, providing an impetus for future studies to identify agents that synergize with this class of agents for improved tumor control in PDAC. SIGNIFICANCE: The UAE1 inhibitor TAK-243, mediates activation of the unfolded protein response, accumulation of DNA breaks and apoptosis, providing a rationale for the use as a safe and efficacious anti-cancer therapeutic for PDAC.

The Landscape of Circular RNA in Cancer.

Circular RNAs (circRNAs) are an intriguing class of RNA due to their covalently closed structure, high stability, and implicated roles in gene regulation. Here, we used an exome capture RNA sequencing protocol to detect and characterize circRNAs across >2,000 cancer samples. When compared against Ribo-Zero and RNase R, capture sequencing significantly enhanced the enrichment of circRNAs and preserved accurate circular-to-linear ratios. Using capture sequencing, we built the most comprehensive catalog of circRNA species to date: MiOncoCirc, the first database to be composed primarily of circRNAs directly detected in tumor tissues. Using MiOncoCirc, we identified candidate circRNAs to serve as biomarkers for prostate cancer and were able to detect circRNAs in urine. We further detected a novel class of circular transcripts, termed read-through circRNAs, that involved exons originating from different genes. MiOncoCirc will serve as a valuable resource for the development of circRNAs as diagnostic or therapeutic targets across cancer types.

EWS/ETS-Driven Ewing Sarcoma Requires BET Bromodomain Proteins.

The EWS/ETS fusion transcription factors drive Ewing sarcoma (EWS) by orchestrating an oncogenic transcription program. Therapeutic targeting of EWS/ETS has been unsuccessful; however, identifying mediators of the EWS/ETS function could offer new therapeutic options. Here, we describe the dependency of EWS/ETS-driven transcription upon chromatin reader BET bromdomain proteins and investigate the potential of BET inhibitors in treating EWS. EWS/FLI1 and EWS/ERG were found in a transcriptional complex with BRD4, and knockdown of BRD2/3/4 significantly impaired the oncogenic phenotype of EWS cells. RNA-seq analysis following BRD4 knockdown or inhibition with JQ1 revealed an attenuated EWS/ETS transcriptional signature. In contrast to previous reports, JQ1 reduced proliferation and induced apoptosis through MYC-independent mechanisms without affecting EWS/ETS protein levels; this was confirmed by depleting BET proteins using PROTAC-BET degrader (BETd). Polycomb repressive complex 2 (PRC2)-associated factor PHF19 was downregulated by JQ1/BETd or BRD4 knockdown in multiple EWS lines. EWS/FLI1 bound a distal regulatory element of PHF19, and EWS/FLI1 knockdown resulted in downregulation of PHF19 expression. Deletion of PHF19 via CRISPR-Cas9 resulted in a decreased tumorigenic phenotype, a transcriptional signature that overlapped with JQ1 treatment, and increased sensitivity to JQ1. PHF19 expression was also associated with worse prognosis in patients with EWS. In vivo, JQ1 demonstrated antitumor efficacy in multiple mouse xenograft models of EWS. Together these results indicate that EWS/ETS requires BET epigenetic reader proteins for its transcriptional program and can be mitigated by BET inhibitors. This study provides a clear rationale for the clinical utility of BET inhibitors in treating EWS.Significance: These findings reveal the dependency of EWS/ETS transcription factors on BET epigenetic reader proteins and demonstrate the potential of BET inhibitors for the treatment of EWS. Cancer Res; 78(16); 4760-73. ©2018 AACR.

aBETting therapeutic resistance by Wnt signaling.

BET inhibition has emerged as a promising epigenetic therapy for malignancies in the last five years, but little consensus has developed regarding what may mediate the axis between sensitivity and resistance. Two recent papers published in Nature attempt to address this question in acute myeloid leukemia (AML) and independently identify the Wnt signaling pathway as a driver and biomarker of therapeutic resistance.

Combined inhibition of Wee1 and PARP1/2 for radiosensitization in pancreatic cancer.

PURPOSE: While the addition of radiation to chemotherapy improves survival in patients with locally advanced pancreatic cancer, more effective therapies are urgently needed. Thus, we investigated the radiosensitizing efficacy of the novel drug combination of Wee1 and PARP1/2 inhibitors (AZD1775 and olaparib, respectively) in pancreatic cancer. EXPERIMENTAL DESIGN: Radiosensitization of AsPC-1 or MiaPaCa-2 human pancreatic cancer cells was assessed by clonogenic survival and tumor growth assays. Mechanistically, the effects of AZD1775, olaparib, and radiation on cell cycle, DNA damage (γH2AX), and homologous recombination repair (HRR) were determined. RESULTS: Treatment of AsPC-1 and MiaPaCa-2 cells with either AZD1775 or olaparib caused modest radiosensitization, whereas treatment with the combination significantly increased radiosensitization. Radiosensitization by the combination of AZD1775 and olaparib was associated with G2 checkpoint abrogation and persistent DNA damage. In addition, AZD1775 inhibited HRR activity and prevented radiation-induced Rad51 focus formation. Finally, in vivo, in MiaPaCa-2-derived xenografts, olaparib did not radiosensitize, whereas AZD1775 produced moderate, yet significant, radiosensitization (P < 0.05). Importantly, the combination of AZD1775 and olaparib produced highly significant radiosensitization (P < 0.0001) evidenced by a 13-day delay in tumor volume doubling (vs. radiation alone) and complete eradication of 20% of tumors. CONCLUSIONS: Taken together, these results demonstrate the efficacy of combined inhibition of Wee1 and PARP inhibitors for radiosensitizing pancreatic cancers and support the model that Wee1 inhibition sensitizes cells to PARP inhibitor-mediated radiosensitization through inhibition of HRR and abrogation of the G2 checkpoint, ultimately resulting in unrepaired, lethal DNA damage and radiosensitization. Clin Cancer Res; 20(19); 5085-96. ©2014 AACR.

Therapeutic targeting of BET bromodomain proteins in castration-resistant prostate cancer.

Men who develop metastatic castration-resistant prostate cancer (CRPC) invariably succumb to the disease. Progression to CRPC after androgen ablation therapy is predominantly driven by deregulated androgen receptor (AR) signalling. Despite the success of recently approved therapies targeting AR signalling, such as abiraterone and second-generation anti-androgens including MDV3100 (also known as enzalutamide), durable responses are limited, presumably owing to acquired resistance. Recently, JQ1 and I-BET762 two selective small-molecule inhibitors that target the amino-terminal bromodomains of BRD4, have been shown to exhibit anti-proliferative effects in a range of malignancies. Here we show that AR-signalling-competent human CRPC cell lines are preferentially sensitive to bromodomain and extraterminal (BET) inhibition. BRD4 physically interacts with the N-terminal domain of AR and can be disrupted by JQ1 (refs 11, 13). Like the direct AR antagonist MDV3100, JQ1 disrupted AR recruitment to target gene loci. By contrast with MDV3100, JQ1 functions downstream of AR, and more potently abrogated BRD4 localization to AR target loci and AR-mediated gene transcription, including induction of the TMPRSS2-ERG gene fusion and its oncogenic activity. In vivo, BET bromodomain inhibition was more efficacious than direct AR antagonism in CRPC xenograft mouse models. Taken together, these studies provide a novel epigenetic approach for the concerted blockade of oncogenic drivers in advanced prostate cancer.

Sensitization of pancreatic cancer to chemoradiation by the Chk1 inhibitor MK8776.

PURPOSE: The combination of radiation with chemotherapy is the most effective therapy for unresectable pancreatic cancer. To improve upon this regimen, we combined the selective Checkpoint kinase 1 (Chk1) inhibitor MK8776 with gemcitabine-based chemoradiation in preclinical pancreatic cancer models. EXPERIMENTAL DESIGN: We tested the ability of MK8776 to sensitize to gemcitabine-radiation in homologous recombination repair (HRR)-proficient and -deficient pancreatic cancer cells and assessed Rad51 focus formation. In vivo, we investigated the efficacy, tumor cell selectivity, and pharmacodynamic biomarkers of sensitization by MK8776. RESULTS: We found that MK8776 significantly sensitized HRR-proficient (AsPC-1, MiaPaCa-2, BxPC-3) but not -deficient (Capan-1) pancreatic cancer cells to gemcitabine-radiation and inhibited Rad51 focus formation in HRR-proficient cells. In vivo, MiaPaCa-2 xenografts were significantly sensitized to gemcitabine-radiation by MK8776 without significant weight loss or observable toxicity in the small intestine, the dose-limiting organ for chemoradiation therapy in pancreatic cancer. We also assessed pChk1 (S345), a pharmacodynamic biomarker of DNA damage in response to Chk1 inhibition in both tumor and small intestine and found that MK8776 combined with gemcitabine or gemcitabine-radiation produced a significantly greater increase in pChk1 (S345) in tumor relative to small intestine, suggesting greater DNA damage in tumor than in normal tissue. Furthermore, we demonstrated the utility of an ex vivo platform for assessment of pharmacodynamic biomarkers of Chk1 inhibition in pancreatic cancer. CONCLUSIONS: Together, our results suggest that MK8776 selectively sensitizes HRR-proficient pancreatic cancer cells and xenografts to gemcitabine-radiation and support the clinical investigation of MK8776 in combination with gemcitabine-radiation in locally advanced pancreatic cancer.