Interplay of Immunosuppression and Immunotherapy Among Patients With Cancer and COVID-19

Importance

Cytokine storm due to COVID-19 can cause high morbidity and mortality and may be more common in patients with cancer treated with immunotherapy (IO) due to immune system activation.

Objective

To determine the association of baseline immunosuppression and/or IO-based therapies with COVID-19 severity and cytokine storm in patients with cancer.

Design, Setting, and Participants

This registry-based retrospective cohort study included 12 046 patients reported to the COVID-19 and Cancer Consortium (CCC19) registry from March 2020 to May 2022. The CCC19 registry is a centralized international multi-institutional registry of patients with COVID-19 with a current or past diagnosis of cancer. Records analyzed included patients with active or previous cancer who had a laboratory-confirmed infection with SARS-CoV-2 by polymerase chain reaction and/or serologic findings.

Exposures

Immunosuppression due to therapy; systemic anticancer therapy (IO or non-IO).

Main Outcomes and Measures

The primary outcome was a 5-level ordinal scale of COVID-19 severity: no complications; hospitalized without requiring oxygen; hospitalized and required oxygen; intensive care unit admission and/or mechanical ventilation; death. The secondary outcome was the occurrence of cytokine storm.

Results

The median age of the entire cohort was 65 years (interquartile range [IQR], 54-74) years and 6359 patients were female (52.8%) and 6598 (54.8%) were non-Hispanic White. A total of 599 (5.0%) patients received IO, whereas 4327 (35.9%) received non-IO systemic anticancer therapies, and 7120 (59.1%) did not receive any antineoplastic regimen within 3 months prior to COVID-19 diagnosis. Although no difference in COVID-19 severity and cytokine storm was found in the IO group compared with the untreated group in the total cohort (adjusted odds ratio [aOR], 0.80; 95% CI, 0.56-1.13, and aOR, 0.89; 95% CI, 0.41-1.93, respectively), patients with baseline immunosuppression treated with IO (vs untreated) had worse COVID-19 severity and cytokine storm (aOR, 3.33; 95% CI, 1.38-8.01, and aOR, 4.41; 95% CI, 1.71-11.38, respectively). Patients with immunosuppression receiving non-IO therapies (vs untreated) also had worse COVID-19 severity (aOR, 1.79; 95% CI, 1.36-2.35) and cytokine storm (aOR, 2.32; 95% CI, 1.42-3.79).

Conclusions and Relevance

This cohort study found that in patients with cancer and COVID-19, administration of systemic anticancer therapies, especially IO, in the context of baseline immunosuppression was associated with severe clinical outcomes and the development of cytokine storm.

Trial Registration

ClinicalTrials.gov Identifier: NCT04354701.

A Framework for Promoting Diversity, Equity, and Inclusion in Genetics and Genomics Research

IMPORTANCE

Research into the genetic and genomic ("genomics") foundations of disease is central to our understanding of disease prevention, early detection, diagnostic accuracy, and therapeutic intervention. Inequitable participation in genomics research by historically excluded populations limits the ability to translate genomic knowledge to achieve health equity and ensure that findings are generalizable to diverse populations.

OBSERVATIONS

We propose a novel framework for promoting diversity, equity, and inclusion in genomics research. Building on principles of community-based participatory research and collective impact frameworks, the framework can guide our understanding of the social, cultural, health system, policy, community, and individual contexts in which engagement and genomics research are being done. Our framework highlights the involvement of a multistakeholder team, including the participants and communities to be engaged, to ensure robust methods for recruitment, retention, return of genomic results, quality of engagement, follow-up, and monitoring of participants.

CONCLUSIONS AND RELEVANCE

The proposed engagement framework will guide investigators in optimizing equitable representation in research and enhancing the rigor of genomics investigation.

The Rise of the Expert Patient in Cancer: From Backseat Passenger to Co-navigator

PURPOSE

Patients who have cancer have leveraged the Internet to gain a better understanding of their disease and connect across geographic boundaries with others facing the same challenges. Online cancer communities have developed into resources that highlight new research and evolving care pathways. Combined with increasing health literacy and social media, they have enabled some patients to become experts in their cancer. This combination of empowerment and expertise describes the new "e-patients."

METHODS

We reviewed the literature to identify key areas where expert e-patients have directly participated in advancing cancer medicine, as well as opportunities available to those who wish to become more involved in research advocacy.

RESULTS

E-patients are widely acknowledged as key stakeholders in oncology by clinicians, researchers, cancer centers, government agencies, and nonprofits. Their input is vital for informing cancer care delivery, developing and launching research initiatives, creating care guidelines and pathways, and formulating policy.

CONCLUSION

Expert e-patients play an expanded role in their own care and in larger conversations regarding practice, research, and policy. Clinicians can engage e-patients as partners in cancer care as we work together towards improving health care access and outcomes for people with cancer.

Racial Disparities in COVID-19 Outcomes Among Black and White Patients With Cancer

IMPORTANCE

Non-Hispanic Black individuals experience a higher burden of COVID-19 than the general population; hence, there is an urgent need to characterize the unique clinical course and outcomes of COVID-19 in Black patients with cancer.

OBJECTIVE

To investigate racial disparities in severity of COVID-19 presentation, clinical complications, and outcomes between Black patients and non-Hispanic White patients with cancer and COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used data from the COVID-19 and Cancer Consortium registry from March 17, 2020, to November 18, 2020, to examine the clinical characteristics and outcomes of COVID-19 in Black patients with cancer. Data analysis was performed from December 2020 to February 2021.

EXPOSURES

Black and White race recorded in patient's electronic health record.

MAIN OUTCOMES AND MEASURES

An a priori 5-level ordinal scale including hospitalization intensive care unit admission, mechanical ventilation, and all-cause death.

RESULTS

Among 3506 included patients (1768 women [50%]; median [IQR] age, 67 [58-77] years), 1068 (30%) were Black and 2438 (70%) were White. Black patients had higher rates of preexisting comorbidities compared with White patients, including obesity (480 Black patients [45%] vs 925 White patients [38%]), diabetes (411 Black patients [38%] vs 574 White patients [24%]), and kidney disease (248 Black patients [23%] vs 392 White patients [16%]). Despite the similar distribution of cancer type, cancer status, and anticancer therapy at the time of COVID-19 diagnosis, Black patients presented with worse illness and had significantly worse COVID-19 severity (unweighted odds ratio, 1.34 [95% CI, 1.15-1.58]; weighted odds ratio, 1.21 [95% CI, 1.11-1.33]).

CONCLUSIONS AND RELEVANCE

These findings suggest that Black patients with cancer experience worse COVID-19 outcomes compared with White patients. Understanding and addressing racial inequities within the causal framework of structural racism is essential to reduce the disproportionate burden of diseases, such as COVID-19 and cancer, in Black patients.

Abstract PD6-02: The metastatic breast cancer project - Expanding the clinical, genomic, and transcriptomic landscape of metastatic breast cancer through patient-partnered research

Background: The Metastatic Breast Cancer Project (MBCproject) is an ongoing research study that directly engages patients (pts) through social media and advocacy groups, and empowers them to share their biospecimens, clinical history, and experiences. The goal is to create a publicly available dataset of linked clinicogenomic and pt-reported data to enable research. From 2015-10-20 to 2020-3-31, 3,245 MBC pts who received treatment at >1,700 institutions, consented to share medical records, pt-reported data, and tumor/saliva/blood samples and to have genomic analysis performed. Here, we describe an analysis of the clinical and genomic features in this initial MBCproject cohort. Methods: We performed whole exome sequencing (WES) on 379 tumors (with matched germline) from 301 pts, 377 germline samples and RNA sequencing (RNA-seq) from 200 tumors from 141 pts. In 14 pts, we characterized 2 or more serial tumor biopsies. WES data was analyzed for mutations and copy number variants. RNA-seq data was used to call fusions, research-grade PAM50, and gene set enrichment scores. Medical records and pt-reported data were abstracted to create detailed clinical record for each pt. Results: WES of 249 metastatic tumors identified 34 cancer genes (e.g., TP53, PIK3CA, CDH1, PTEN, AKT1, NF1, ESR1) that were significantly recurrently altered. Potential clinically actionable alterations were identified in 39% of metastatic tumors. 45 tumors (22.5%) had fusions with known functional effects and 24 (12%) had in-frame fusions in key cancer genes like FANCD2 (3), FGFR3 (2), ESR1 (1), BRAF (1), and NCOR1 (1). PAM50 classification suggested depletion of Luminal A subtype in this cohort compared to TCGA breast cancer cohort (p-value <0.05). Of 29 pts with paired RNA-seq biopsies, 10 pts showed a PAM50 subtype switch [LumB to Basal = 1, Her2 to Basal =1, Basal to LumA = 1, Her2 to LumA = 2, LumA/B to Her2 = 3, LumA to LumB = 2]. Germline analysis showed that 30.2% (114/377) of pts had at least one pathogenic variant in a cancer predisposition gene, including BRCA1/BRCA2 (5%), NF1 (5.8%), ATM (1.06%) and PALB2 (1.59%). In 10.9% pts (33/301), pathogenic variants in a cancer predisposition gene was accompanied by an apparent somatic loss of function event in the same gene. There was ~ 90% concordance between abstracted features (e.g., receptor status, histology, diagnosis dates, metastatic sites) and pt-reported data, enabling the use of both data types for integrated analyses. The utility of integrated analyses is illustrated by a case study of a pt who had an initial diagnosis of ductal carcinoma in situ and developed metastatic disease 5.5 yrs later. Analysis of 3 metastatic tumors (WES and RNA-seq) and a circulating tumor DNA sample (WES only) from this pt collected over the course of therapy revealed evidence of tumor evolution and multiple mechanisms of resistance to endocrine therapies and CDK4/6 inhibitors, including 2 distinct acquired ESR1 mutations, an activating BRAF fusion, and estrogen receptor (ER) loss by immunohistochemistry with concomitant development of ESR1-PLEKHG1 in-frame fusion. RNA-seq data also showed a PAM50 luminal phenotype and a persistent ER. signature throughout despite the apparent ER loss, suggesting compensation by the ESR1 fusion. Analyses of 13 additional pts with serial biopsies will be presented. Integrated analyses of several additional cohorts of interest, such as de novo MBC (91 pts), resistance to CDK4/6 inhibitors (39 pts), and pts diagnosed with breast cancer <40 yrs, will also be presented. Conclusion: This clinicogenomic dataset generated by partnering directly with pts was uniquely built with pt-reported data, medical record data, and multi-omic characterization, and serves as a powerful tool for researchers to harness to accelerate discoveries in MBC.

Citation Format: Esha Jain, Dewey Kim, Jorge Gomez Tejeda Zanudo, Sara Balch, Mary McGillicuddy, Brett N. Tomson, Tania G. Hernandez, Beena S. Thomas, Daniel L. Abravanel, Shahrayz Shah, Rafael Ramos, Delia Sosa, Ilan Small, Lauren Sterlin, Sarah Winnicki, Colleen Nguyen, Micheal Dunphy, Elana Anastasio, Todd R. Golub, Corrie A. Painter, Nikhil Wagle. The metastatic breast cancer project - Expanding the clinical, genomic, and transcriptomic landscape of metastatic breast cancer through patient-partnered research [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD6-02.

The CoVID-TE risk assessment model for venous thromboembolism in hospitalized patients with cancer and COVID-19

BACKGROUND

Hospitalized patients with COVID-19 have increased risks of venous (VTE) and arterial thromboembolism (ATE). Active cancer diagnosis and treatment are well-known risk factors; however, a risk assessment model (RAM) for VTE in patients with both cancer and COVID-19 is lacking.

OBJECTIVES

To assess the incidence of and risk factors for thrombosis in hospitalized patients with cancer and COVID-19.

METHODS

Among patients with cancer in the COVID-19 and Cancer Consortium registry (CCC19) cohort study, we assessed the incidence of VTE and ATE within 90 days of COVID-19-associated hospitalization. A multivariable logistic regression model specifically for VTE was built using a priori determined clinical risk factors. A simplified RAM was derived and internally validated using bootstrap.

RESULTS

From March 17, 2020 to November 30, 2020, 2804 hospitalized patients were analyzed. The incidence of VTE and ATE was 7.6% and 3.9%, respectively. The incidence of VTE, but not ATE, was higher in patients receiving recent anti-cancer therapy. A simplified RAM for VTE was derived and named CoVID-TE (Cancer subtype high to very-high risk by original Khorana score +1, VTE history +2, ICU admission +2, D-dimer elevation +1, recent systemic anti-cancer Therapy +1, and non-Hispanic Ethnicity +1). The RAM stratified patients into two cohorts (low-risk, 0-2 points, n = 1423 vs. high-risk, 3+ points, n = 1034) where VTE occurred in 4.1% low-risk and 11.3% high-risk patients (c statistic 0.67, 95% confidence interval 0.63-0.71). The RAM performed similarly well in subgroups of patients not on anticoagulant prior to admission and moderately ill patients not requiring direct ICU admission.

CONCLUSIONS

Hospitalized patients with cancer and COVID-19 have elevated thrombotic risks. The CoVID-TE RAM for VTE prediction may help real-time data-driven decisions in this vulnerable population.

Association of clinical factors and recent anticancer therapy with COVID-19 severity among patients with cancer: a report from the COVID-19 and Cancer Consortium

BACKGROUND

Patients with cancer may be at high risk of adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We analyzed a cohort of patients with cancer and coronavirus 2019 (COVID-19) reported to the COVID-19 and Cancer Consortium (CCC19) to identify prognostic clinical factors, including laboratory measurements and anticancer therapies.

PATIENTS AND METHODS

Patients with active or historical cancer and a laboratory-confirmed SARS-CoV-2 diagnosis recorded between 17 March and 18 November 2020 were included. The primary outcome was COVID-19 severity measured on an ordinal scale (uncomplicated, hospitalized, admitted to intensive care unit, mechanically ventilated, died within 30 days). Multivariable regression models included demographics, cancer status, anticancer therapy and timing, COVID-19-directed therapies, and laboratory measurements (among hospitalized patients).

RESULTS

A total of 4966 patients were included (median age 66 years, 51% female, 50% non-Hispanic white); 2872 (58%) were hospitalized and 695 (14%) died; 61% had cancer that was present, diagnosed, or treated within the year prior to COVID-19 diagnosis. Older age, male sex, obesity, cardiovascular and pulmonary comorbidities, renal disease, diabetes mellitus, non-Hispanic black race, Hispanic ethnicity, worse Eastern Cooperative Oncology Group performance status, recent cytotoxic chemotherapy, and hematologic malignancy were associated with higher COVID-19 severity. Among hospitalized patients, low or high absolute lymphocyte count; high absolute neutrophil count; low platelet count; abnormal creatinine; troponin; lactate dehydrogenase; and C-reactive protein were associated with higher COVID-19 severity. Patients diagnosed early in the COVID-19 pandemic (January-April 2020) had worse outcomes than those diagnosed later. Specific anticancer therapies (e.g. R-CHOP, platinum combined with etoposide, and DNA methyltransferase inhibitors) were associated with high 30-day all-cause mortality.

CONCLUSIONS

Clinical factors (e.g. older age, hematological malignancy, recent chemotherapy) and laboratory measurements were associated with poor outcomes among patients with cancer and COVID-19. Although further studies are needed, caution may be required in utilizing particular anticancer therapies.

CLINICAL TRIAL IDENTIFIER

NCT04354701.

Abstract PS7-01: Characteristics and outcomes of SARS-CoV-2 infection in patients with invasive breast cancer (BC) from the COVID-19 and cancer consortium (CCC19) cohort study

Background: Overall, patients with cancer experience a greater risk of adverse outcomes following SARS-CoV-2 infection; however, little is known for those with BC.

Methods: CCC19 (NCT04354701) is an international cohort study aimed at investigating the impact of COVID-19 in patients with a history of or active cancer using de-identified data on patient demographics, cancer history, clinical course and outcomes of COVID-19. The current analysis includes patients from U.S. and Canada with invasive BC and laboratory-confirmed SARS-CoV-2 entered between March 17, 2020 and July 2, 2020. Co-primary outcomes were hospitalization during COVID-19 illness and 30-day all-cause mortality. Frequencies for categorical variables and medians (range) for continuous variables were estimated. Final presentation will include bivariable and multivariable Cox proportional hazards regression analysis to identify risk factors (including BC subtypes and therapies, for which data collection is ongoing) associated with 30-day all-cause mortality and severe COVID-19 illness (composite of any hospitalization requiring supplemental oxygen, admission to an intensive care unit [ICU], use of mechanical ventilation, or death).

Results: During the study period, a total of 2683 patients with cancer and COVID-19 were accrued in the CCC19 registry including 529 (20%) with invasive BC. Among patients with BC, 352 (67%) were 60 years or older; 518 (98%) were women; 275 (52%) non-Hispanic White, 116 (22%) non-Hispanic Black, 70 (13%) Hispanic, 56 (11%) in other categorizations; 178 (34%) had a smoking history; 75 (14%) ECOG performance status ≥2; 191 (36%) with >2 active comorbidities; 64 (12%) with AJCC stage IV disease at BC diagnosis; and 267 (50%) were on anti-cancer treatment including systemic therapy, radiation, or surgery within 3 months of COVID-19 diagnosis. At least 323 (61%) patients with BC had 30-day follow-up after COVID-19 diagnosis, and 35 (7%) had 90-day follow-up. COVID-19 illness at initial diagnosis required outpatient care in 288 (54%), inpatient care in 193 (36%), and ICU care in 40 (8%). Overall, 247 (47%) were hospitalized and 30-day all-cause mortality was 9%. 30-day all-cause mortality rates by receipt of major BC treatment modalities (within past 3 months) were: 10% for those on cytotoxic systemic therapy vs 5% and 12% for noncytotoxic systemic therapy and local therapy, respectively. The table shows hospitalization and mortality outcomes by major demographic and BC treatment strata. The final presentation will incorporate the latest patient accrual and evaluate independent clinical risk factors associated with serious COVID-19 outcomes in patients with BC.

Conclusions: This represents the largest study to date of COVID-19 outcomes in patients with invasive BC. Nearly half of the patients with BC required hospitalization during their COVID-19 disease course and we observed a 9% 30-day all-cause mortality.

Submitted on behalf of the COVID-19 and Cancer Consortium (ccc19us.org)

Table 1. COVID-19 related hospitalization and 30-day all-cause mortality for all patients with invasive BCNAny Hospitalization30-day all-cause MortalityN% [95% CI]N% [95% CI]Total population52924747 [42-51]499 [7-12]Age<601774425 [19-32]21 [0-4]60-691155144 [35-54]87 [3-13]70-791206655 [46-64]1714 [8-22]80+1178674 [65-81]2219 [12-27]ECOG PS0-132212238 [33-43]165 [3-8]2+756181 [71-89]1621 [13-32]Active Comorbidities0741014 [7-23]00 [0-5]1-22239442 [36-49]178 [5-12]>219112968 [60-74]2915 [10-21]Treatment IntentCurative1866434 [28-42]95 [2-9]Palliative743953 [41-64]1216 [9-27]Cancer StatusRemission/NED33115447 [41-52]247 [5-11]Active disease, stable or responding to treatment1194840 [31-50]76 [2-12]Active disease, progressing372773 [56-86]1130 [16-47]Treatment Modality (within 3 months)Cytotoxic chemotherapy833542 [31-54]810 [4-18]Noncytotoxic therapy1856435 [28-42]105 [3-10]Local therapy (surgery or radiation)341750 [32-68]412 [3-27]

Citation Format: Ali Raza Khaki, Dimpy P Shah, Maryam B Lustberg, Melissa K Accordino, Daniel G Stover, Gayathri Nagaraj, Donna R Rivera, Edith A Perez, Sara M Tolaney, Jeffrey Peppercorn, Petros Grivas, Jeremy L Warner, Corrie A Painter, Gilberto de Lima Lopes, Jr, Solange Peters, Michael A Thompson, Toni K Choueiri, Brian I Rini, Gary H Lyman, Nicole M Kuderer, Shaveta Vinayak. Characteristics and outcomes of SARS-CoV-2 infection in patients with invasive breast cancer (BC) from the COVID-19 and cancer consortium (CCC19) cohort study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-01.

COVID-19 and Cancer: Current Challenges and Perspectives

Patients with cancer have been disproportionately affected by the COVID-19 pandemic. This effect has included the adverse outcomes in patients with cancer who develop COVID-19, the impact of the COVID-19 pandemic on the delivery of cancer care, and the severe disruption to cancer research. However, patients with cancer are a heterogeneous population, and recent studies have now documented factors that allow risk stratification of patients with cancer in order to optimize care. In this review, we highlight data at the intersection of COVID-19 and cancer, including the biological interplay between the two diseases and practical recommendations for the treatment of patients with cancer during the pandemic. We additionally discuss the potential long-lasting impact of the pandemic on cancer care due to its deleterious effect on cancer research, as well as biological insights from the cancer research community that could help develop novel therapies for all patients with COVID-19.

Utilization of COVID-19 Treatments and Clinical Outcomes among Patients with Cancer: A COVID-19 and Cancer Consortium (CCC19) Cohort Study

Among 2,186 U.S. adults with invasive cancer and laboratory-confirmed SARS-CoV-2 infection, we examined the association of COVID-19 treatments with 30-day all-cause mortality and factors associated with treatment. Logistic regression with multiple adjustments (e.g., comorbidities, cancer status, baseline COVID-19 severity) was performed. Hydroxychloroquine with any other drug was associated with increased mortality versus treatment with any COVID-19 treatment other than hydroxychloroquine or untreated controls; this association was not present with hydroxychloroquine alone. Remdesivir had numerically reduced mortality versus untreated controls that did not reach statistical significance. Baseline COVID-19 severity was strongly associated with receipt of any treatment. Black patients were approximately half as likely to receive remdesivir as white patients. Although observational studies can be limited by potential unmeasured confounding, our findings add to the emerging understanding of patterns of care for patients with cancer and COVID-19 and support evaluation of emerging treatments through inclusive prospective controlled trials. SIGNIFICANCE: Evaluating the potential role of COVID-19 treatments in patients with cancer in a large observational study, there was no statistically significant 30-day all-cause mortality benefit with hydroxychloroquine or high-dose corticosteroids alone or in combination; remdesivir showed potential benefit. Treatment receipt reflects clinical decision-making and suggests disparities in medication access.This article is highlighted in the In This Issue feature, p. 1426.

Broad host range of SARS-CoV-2 predicted by comparative and structural analysis of ACE2 in vertebrates

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of COVID-19. The main receptor of SARS-CoV-2, angiotensin I converting enzyme 2 (ACE2), is now undergoing extensive scrutiny to understand the routes of transmission and sensitivity in different species. Here, we utilized a unique dataset of ACE2 sequences from 410 vertebrate species, including 252 mammals, to study the conservation of ACE2 and its potential to be used as a receptor by SARS-CoV-2. We designed a five-category binding score based on the conservation properties of 25 amino acids important for the binding between ACE2 and the SARS-CoV-2 spike protein. Only mammals fell into the medium to very high categories and only catarrhine primates into the very high category, suggesting that they are at high risk for SARS-CoV-2 infection. We employed a protein structural analysis to qualitatively assess whether amino acid changes at variable residues would be likely to disrupt ACE2/SARS-CoV-2 spike protein binding and found the number of predicted unfavorable changes significantly correlated with the binding score. Extending this analysis to human population data, we found only rare (frequency <0.001) variants in 10/25 binding sites. In addition, we found significant signals of selection and accelerated evolution in the ACE2 coding sequence across all mammals, and specific to the bat lineage. Our results, if confirmed by additional experimental data, may lead to the identification of intermediate host species for SARS-CoV-2, guide the selection of animal models of COVID-19, and assist the conservation of animals both in native habitats and in human care.

Clinical impact of COVID-19 on patients with cancer (CCC19): a cohort study

BACKGROUND

Data on patients with COVID-19 who have cancer are lacking. Here we characterise the outcomes of a cohort of patients with cancer and COVID-19 and identify potential prognostic factors for mortality and severe illness.

METHODS

In this cohort study, we collected de-identified data on patients with active or previous malignancy, aged 18 years and older, with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection from the USA, Canada, and Spain from the COVID-19 and Cancer Consortium (CCC19) database for whom baseline data were added between March 17 and April 16, 2020. We collected data on baseline clinical conditions, medications, cancer diagnosis and treatment, and COVID-19 disease course. The primary endpoint was all-cause mortality within 30 days of diagnosis of COVID-19. We assessed the association between the outcome and potential prognostic variables using logistic regression analyses, partially adjusted for age, sex, smoking status, and obesity. This study is registered with ClinicalTrials.gov, NCT04354701, and is ongoing.

FINDINGS

Of 1035 records entered into the CCC19 database during the study period, 928 patients met inclusion criteria for our analysis. Median age was 66 years (IQR 57-76), 279 (30%) were aged 75 years or older, and 468 (50%) patients were male. The most prevalent malignancies were breast (191 [21%]) and prostate (152 [16%]). 366 (39%) patients were on active anticancer treatment, and 396 (43%) had active (measurable) cancer. At analysis (May 7, 2020), 121 (13%) patients had died. In logistic regression analysis, independent factors associated with increased 30-day mortality, after partial adjustment, were: increased age (per 10 years; partially adjusted odds ratio 1·84, 95% CI 1·53-2·21), male sex (1·63, 1·07-2·48), smoking status (former smoker vs never smoked: 1·60, 1·03-2·47), number of comorbidities (two vs none: 4·50, 1·33-15·28), Eastern Cooperative Oncology Group performance status of 2 or higher (status of 2 vs 0 or 1: 3·89, 2·11-7·18), active cancer (progressing vs remission: 5·20, 2·77-9·77), and receipt of azithromycin plus hydroxychloroquine (vs treatment with neither: 2·93, 1·79-4·79; confounding by indication cannot be excluded). Compared with residence in the US-Northeast, residence in Canada (0·24, 0·07-0·84) or the US-Midwest (0·50, 0·28-0·90) were associated with decreased 30-day all-cause mortality. Race and ethnicity, obesity status, cancer type, type of anticancer therapy, and recent surgery were not associated with mortality.

INTERPRETATION

Among patients with cancer and COVID-19, 30-day all-cause mortality was high and associated with general risk factors and risk factors unique to patients with cancer. Longer follow-up is needed to better understand the effect of COVID-19 on outcomes in patients with cancer, including the ability to continue specific cancer treatments.

FUNDING

American Cancer Society, National Institutes of Health, and Hope Foundation for Cancer Research.

Broad Host Range of SARS-CoV-2 Predicted by Comparative and Structural Analysis of ACE2 in Vertebrates

The novel coronavirus SARS-CoV-2 is the cause of Coronavirus Disease-2019 (COVID-19). The main receptor of SARS-CoV-2, angiotensin I converting enzyme 2 (ACE2), is now undergoing extensive scrutiny to understand the routes of transmission and sensitivity in different species. Here, we utilized a unique dataset of 410 vertebrates, including 252 mammals, to study cross-species conservation of ACE2 and its likelihood to function as a SARS-CoV-2 receptor. We designed a five-category ranking score based on the conservation properties of 25 amino acids important for the binding between receptor and virus, classifying all species from very high to very low. Only mammals fell into the medium to very high categories, and only catarrhine primates in the very high category, suggesting that they are at high risk for SARS-CoV-2 infection. We employed a protein structural analysis to qualitatively assess whether amino acid changes at variable residues would be likely to disrupt ACE2/SARS-CoV-2 binding, and found the number of predicted unfavorable changes significantly correlated with the binding score. Extending this analysis to human population data, we found only rare (<0.1%) variants in 10/25 binding sites. In addition, we observed evidence of positive selection in ACE2 in multiple species, including bats. Utilized appropriately, our results may lead to the identification of intermediate host species for SARS-CoV-2, justify the selection of animal models of COVID-19, and assist the conservation of animals both in native habitats and in human care.

Identification and characterization of T reg-like cells in zebrafish

Kasheta et al. report the identification of T reg–like cells in zebrafish, a means to track and live-image these cells, and foxp3a-deficient mutants that display lymphoproliferation, severe inflammation, and other hallmarks of T reg deficiency syndromes.

Regulatory T (T reg) cells are a specialized sublineage of T lymphocytes that suppress autoreactive T cells. Functional studies of T reg cells in vitro have defined multiple suppression mechanisms, and studies of T reg–deficient humans and mice have made clear the important role that these cells play in preventing autoimmunity. However, many questions remain about how T reg cells act in vivo. Specifically, it is not clear which suppression mechanisms are most important, where T reg cells act, and how they get there. To begin to address these issues, we sought to identify T reg cells in zebrafish, a model system that provides unparalleled advantages in live-cell imaging and high-throughput genetic analyses. Using a FOXP3 orthologue as a marker, we identified CD4-enriched, mature T lymphocytes with properties of T reg cells. Zebrafish mutant for foxp3a displayed excess T lymphocytes, splenomegaly, and a profound inflammatory phenotype that was suppressed by genetic ablation of lymphocytes. This study identifies T reg–like cells in zebrafish, providing both a model to study the normal functions of these cells in vivo and mutants to explore the consequences of their loss.

Emerging Opportunities for Target Discovery in Rare Cancers

Rare cancers pose unique challenges to research due to their low incidence. Barriers include a scarcity of tissue and experimental models to enable basic research and insufficient patient accrual for clinical studies. Consequently, an understanding of the genetic and cellular features of many rare cancer types and their associated vulnerabilities has been lacking. However, new opportunities are emerging to facilitate discovery of therapeutic targets in rare cancers. Online platforms are allowing patients with rare cancers to organize on an unprecedented scale, tumor genome sequencing is now routinely performed in research and clinical settings, and the efficiency of patient-derived model generation has improved. New CRISPR/Cas9 and small-molecule libraries permit cancer dependency discovery in a rapid and systematic fashion. In parallel, large-scale studies of common cancers now provide reference datasets to help interpret rare cancer profiling data. Together, these advances motivate consideration of new research frameworks to accelerate rare cancer target discovery.

Abstract P1-05-13: The metastatic breast cancer project: Translational genomics through direct patient engagement

Background: The Metastatic Breast Cancer Project is a nationwide research initiative that directly engages patients through social media and advocacy groups and seeks to empower them to share their samples and clinical information to accelerate research. Because the vast majority of patients are treated in the community setting, we sought to determine the feasibility of remotely obtaining tumor and saliva samples as well as medical records from a large cohort of metastatic breast cancer (MBC) patients who receive their care in diverse settings around the country.

Methods: In collaboration with patients and advocacy groups, we developed a website to allow MBC patients across the U.S. to participate. Enrolled patients are sent a saliva kit and asked to mail back a saliva sample, which is used to extract germline DNA. We contact participants' medical providers and obtain medical records and part of their tumor biopsy. Whole exome and transcriptome sequencing is performed on tumor and germline samples. Clinically annotated genomic data are used to identify mechanisms of response and resistance to therapies. The database will be shared widely with researchers. Study updates and discoveries are shared with participants regularly.

Results: In the first 8 months, 2285 MBC patients from all 50 states enrolled. 2163 (95%) completed the 16-question survey about their cancer, treatments, and demographic information. 1232 completed the online consent form permitting acquisition and analysis of medical records, tumor tissue, and saliva samples. 556 saliva samples have been received. Initial medical record and tumor sample requests have been made for patients who have provided saliva samples. To date, we have obtained medical records from 102 patients (93% success rate) and tumor samples from 32 patients (77% success rate). Whole exome and transcriptome sequencing has been successfully completed on initial samples received and is ongoing for additional samples.

Conclusions: Partnering directly with patients through social media and advocacy groups enables rapid identification of thousands of patients willing to share tumors, saliva, and medical records to accelerate research. This approach allows for rapid identification of patients with rare phenotypes such as extraordinary responders, who have been challenging to identify with traditional approaches. Remote acquisition of medical records, saliva samples, and tumor tissue for patients located throughout the U.S. is feasible. Genomic analysis and medical record abstraction for these patients is underway. As data is generated, a clinically annotated database will be shared widely with the research community.

Citation Format: Painter CA, Anastasio E, Krevalin M, Kim D, Larken K, Lennon N, Frank E, Winer EP, Lander ES, Golub T. The metastatic breast cancer project: Translational genomics through direct patient engagement [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-13.

Abstract OT2-05-03: The metastatic breast cancer project: A national direct-to-patient research initiative to accelerate genomics research

Over the past decade, genomic characterization of tumors has shed enormous light on the molecular underpinnings of cancer. These discoveries have led to the development of novel therapies and preventive measures that have already revolutionized cancer care. Despite this progress, the genomics of metastatic breast cancer (MBC), one of the leading causes of cancer death in the U.S., remains poorly understood.

The challenge in studying tumor samples from patients with MBC has been that the tumors from most patients are not available for research, largely because the vast majority of patients are cared for in community settings where genomics studies are not typically conducted. To address this, we have launched a nationwide study, The Metastatic Breast Cancer Project, which seeks to empower patients to accelerate cancer research through sharing their samples and clinical information. We have developed an outreach program in collaboration with MBC advocacy organizations to connect MBC patients around the country with genomics research performed at the Broad Institute, allowing them to participate regardless of where they live.

Working with MBC patients and advocates, we designed a website (www.mbcproject.org) with an online questionnaire that allows patients with MBC to provide information about themselves and their cancer. Based on their answers, patients are offered an electronic consent form that explains the risks and benefits of the study and asks for permission to obtain a portion of their stored tumor tissue, a saliva sample, and copies of their medical records. For patients who consent, our clinical research team contacts their physicians and obtains copies of their medical records, which are reviewed to confirm eligibility. Enrolled patients are sent a saliva kit and asked to mail back a saliva sample, which is used to extract germline DNA. The clinical research team also contacts the patient's pathology department and requests a portion of the tumor to be sent to the Broad Institute for genomic analysis. Whole exome and transcriptome sequencing is performed on tumor and germline DNA. Sequencing data are linked to de-identified clinical information, and the resulting data are used to identify drivers of tumorigenesis, mechanisms of response and resistance to therapies, and diagnostic, prognostic, and therapeutic biomarkers. The database of clinically annotated genomic information will be shared with the NIH and the cancer research community. Study updates and discoveries are shared at regular intervals with all patients who complete the initial questionnaire.

This direct-to-patient approach should be particularly enabling for the identification of patients with rare phenotypes or clinical behavior. For this reason, the first cohorts being studied are patients with extraordinary responses to therapies and patients who present with de novo MBC. Additional cohorts will be added in the future, including young women with MBC and patients with drug-resistant MBC. This project seeks to establish a patient-researcher partnership to accelerate genomic discoveries and improve outcomes in MBC, and may ultimately serve as a means to build a new clinical and translational research model for all patients with cancer.

Citation Format: Wagle N, Painter CA, Ilzarbe M, Van Allen EM, Frank E, Oh C, Krevalin M, Lloyd M, Anderka K, Kryukov G, Boehm JS, Winer E, Lander ES, Golub TR. The metastatic breast cancer project: A national direct-to-patient research initiative to accelerate genomics research. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT2-05-03.

Zebrafish as a platform to study tumor progression

The zebrafish has emerged as a powerful model system to study human diseases, including a variety of neoplasms. Principal components that have contributed to the rise in use of this vertebrate model system are its high fecundity, ease of genetic manipulation, and low cost of maintenance. Vital imaging of the zebrafish is possible from the transparent embryonic stage through adulthood, the latter enabled by a number of mutant lines that ablate pigmentation. As a result, high-resolution analyses of tumor progression can be accomplished in vivo. Straightforward transgenesis of zebrafish has been employed to develop numerous tumor models that recapitulate many aspects of human neoplastic disease, both in terms of pathologic and molecular conservation. The small size of zebrafish embryos has enabled screens for novel chemotherapeutic agents. Its facile genetics have been exploited in studies that extend beyond modeling cancer to investigations that define new cancer genes and mechanisms of cancer progression. Together, these attributes have established the zebrafish as a robust and versatile model system for investigating cancer. In this chapter we describe methods that are used to study a gene's impact on melanoma progression. We detail methods for making transgenic animals and screening for tumor onset as well as methods to investigate tumor invasion and propagation.

Abstract 1273: Adaptive immunity in a zebrafish model of melanoma

The recent success of the anti-CLTA-4 antibody, ipilimumab, for late stage metastatic melanoma, provides proof of principle that stimulating the immune system can have profound effects on patient outcome. However, a detailed understanding of the role of immune-modulating cells within the tumor microenvironment has been confounded by the lack of a suitable model system that would allow for direct visualization of cells within the intact tumor microenvironment. Previous work has demonstrated that the zebrafish, Danio Rerio, can be genetically manipulated to produce melanomas that recapitulate BRAFV600E;P53-/- human tumors. Due to its translucency, ease of genetic manipulation and high fecundity, the zebrafish is an attractive model system that allows for in vivo characterization of cells within intact tissue. Using this model system, we have begun investigating the adaptive immune response to melanoma in zebrafish. We have focused our initial investigations on determining whether transcript expression of key adaptive immune-modulatory proteins are present in the zebrafish and to what extent they are expressed intratumorally . Our studies have found that orthologs of CLTA-4, FOXP3, and CD8 are all expressed in wild-type zebrafish, but not in rag-/- zebrafish. Furthermore, transcript levels of CTLA-4 were greatest in the melanoma tumor relative to other regions of the zebrafish, which is consistent with the constitutive expression of CTLA-4 in human melanomas. Additionally, we have cloned the promoters for zebrafish FOXP3 and CD8 and are developing fluorescent reporter lines that will enable us to visualize and ablate subpopulations of T cells within the tumor. These lines, along with previously described reporter lines for MHC II and lck, will enable us to determine the role of adaptive immune cells during melanoma onset and progression in the zebrafish. Our research supports the notion that there is conservation between the human and zebrafish adaptive immune systems, and that similar immune evasion mechanisms may be contributing to melanoma growth in zebrafish. These data position the zebrafsh as a powerful model system for immunological investigations that focus on the adaptive immune response to melanoma.

Citation Format: Corrie A. Painter, Craig Ceol. Adaptive immunity in a zebrafish model of melanoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1273. doi:10.1158/1538-7445.AM2013-1273

Conformational variation in structures of classical and non-classical MHCII proteins and functional implications

Recent structural characterizations of classical and non-classical major histocompatibility complex class II (MHCII) proteins have provided a view into the dynamic nature of the MHCII-peptide binding groove and the role that structural changes play in peptide loading processes. Although there have been numerous reports of crystal structures for MHCII-peptide complexes, a detailed analysis comparing all the structures has not been reported, and subtle conformational variations present in these structures may not have been fully appreciated. We compared the 91 MHCII crystal structures reported in the PDB to date, including an HLA-DR mutant particularly susceptible to DM-mediated peptide exchange, and reviewed experimental and computational studies of the effect of peptide binding on MHCII structure. These studies provide evidence for conformational lability in and around the α-subunit 3-10 helix at residues α48-51, a region known to be critical for HLA-DM-mediated peptide exchange. A biophysical study of MHC-peptide hydrogen bond strengths and a recent structure of the non-classical MHCII protein HLA-DO reveal changes in the same region. Conformational variability was observed also in the vicinity of a kink in the β-subunit helical region near residue β66 and in the orientation and loop conformation in the β2 Ig domain. Here, we provide an overview of the regions within classical and non-classical MHCII proteins that display conformational changes and the potential role that these changes may have in the peptide loading/exchange process.

Structural Insights Into HLA-DM Mediated MHC II Peptide Exchange

Antigen presentation by class II MHC proteins (MHC-II) is a critical component of the adaptive immune response to foreign pathogens. Our understanding of how antigens are presented has been greatly enhanced by crystallographic studies of MHC-II-peptide complexes, which have shown a canonical extended conformation of peptide antigens within the peptide-binding domain of MHC-II. However, a detailed understanding of the peptide loading process, which is mediated by the accessory molecule HLA-DM (DM), remains unresolved. MHC-II proteins appear to undergo conformational changes during the peptide loading/exchange process that have not been clearly described in a structural context. In the absence of a crystal structure for the DM-MHC-II complex, mutational studies have provided a low resolution understanding as to how these molecules interact. This review will focus on structural and biochemical studies of the MHC-II-peptide interaction, and on studies of the DM-MHC-II interaction, with an emphasis on identifying structural features important for the mechanism of DM mediated peptide catalysis.

Indications of proton-dominated cosmic-ray composition above 1.6 EeV

We report studies of ultrahigh-energy cosmic-ray composition via analysis of depth of air shower maximum (X(max)), for air shower events collected by the High-Resolution Fly's Eye (HiRes) observatory. The HiRes data are consistent with a constant elongation rate d<X(max)>/d[log(E)] of 47.9+/-6.0(stat)+/-3.2(syst) g/cm2/decade for energies between 1.6 and 63 EeV, and are consistent with a predominantly protonic composition of cosmic rays when interpreted via the QGSJET01 and QGSJET-II high-energy hadronic interaction models. These measurements constrain models in which the galactic-to-extragalactic transition is the cause of the energy spectrum ankle at 4x10(18) eV.

Model for the peptide-free conformation of class II MHC proteins

BACKGROUND

Major histocompatibility complex proteins are believed to undergo significant conformational changes concomitant with peptide binding, but structural characterization of these changes has remained elusive.

METHODOLOGY/PRINCIPAL FINDINGS

Here we use molecular dynamics simulations and experimental probes of protein conformation to investigate the peptide-free state of class II MHC proteins. Upon computational removal of the bound peptide from HLA-DR1-peptide complex, the alpha50-59 region folded into the P1-P4 region of the peptide binding site, adopting the same conformation as a bound peptide. Strikingly, the structure of the hydrophobic P1 pocket is maintained by engagement of the side chain of Phe alpha54. In addition, conserved hydrogen bonds observed in crystal structures between the peptide backbone and numerous MHC side chains are maintained between the alpha51-55 region and the rest of the molecule. The model for the peptide-free conformation was evaluated using conformationally-sensitive antibody and superantigen probes predicted to show no change, moderate change, or dramatic changes in their interaction with peptide-free DR1 and peptide-loaded DR1. The binding observed for these probes is in agreement with the movements predicted by the model.

CONCLUSION/SIGNIFICANCE

This work presents a molecular model for peptide-free class II MHC proteins that can help to interpret the conformational changes known to occur within the protein during peptide binding and release, and can provide insight into possible mechanisms for DM action.

First observation of the Greisen-Zatsepin-Kuzmin suppression

The High Resolution Fly's Eye (HiRes) experiment has observed the Greisen-Zatsepin-Kuzmin suppression (called the GZK cutoff) with a statistical significance of five standard deviations. HiRes' measurement of the flux of ultrahigh energy cosmic rays shows a sharp suppression at an energy of 6 x 10(19) eV, consistent with the expected cutoff energy. We observe the ankle of the cosmic-ray energy spectrum as well, at an energy of 4 x 10(18) eV. We describe the experiment, data collection, and analysis and estimate the systematic uncertainties. The results are presented and the calculation of the statistical significance of our observation is described.

Acute tissue-type plasminogen activator release in human microvascular endothelial cells: the roles of Galphaq, PLC-beta, IP3 and 5,6-epoxyeicosatrienoic acid

The acute physiologic release of tissue-type plasminogen activator (t-PA) from the endothelium is critical for vascular homeostasis. This process is prostacyclin- and nitric oxide (NO)-independent in humans. It has been suggested that calcium signaling and endothelial-derived hyperpolarizing factors (EDHF) may play a role in t-PA release. G-protein-coupled receptor-dependent calcium signaling is typically Galphaq-dependent. EDHFs have been functionally defined and in various tissues are believed to be various regioisomers of the epoxyeicosatrienoic acids (EETs). We tested the hypothesis in vitro that thrombin-stimulated t-PA release from human microvascular endothelial cells (HMECs) is both Galphaq- and EDHF-dependent. Conditioned media was harvested following thrombin stimulation, and t-PA antigen was measured by ELISA. Thrombin-induced t-PA release was limited by a membrane-permeable Galphaq inhibitory peptide, the PLC-beta antagonist U73122, and the IP3 receptor antagonist 2-aminoethoxyphenylborane, while the Galphaq agonist Pasteurella toxin modestly induced t-PA release. The cytochrome P450 (CYP450) inhibitor, miconazole, and the arachidonic acid epoxygenase inhibitor MS-PPOH inhibited thrombin-stimulated t-PA release, while 5,6-EET-methyl ester stimulated t-PA release. The 5,6- and 14,15-EET antagonist, 14,15-epoxyeicosa-5(Z)-enoic acid, inhibited t-PA release at the 100 microM concentration. However, thrombin-stimulated t-PA release was unaffected by the prostacyclin and NO inhibitors ASA and L-NAME, as well as the potassium channel inhibitors TEA, apamin and charybdotoxin. These studies suggest that thrombin-stimulated t-PA release is Galphaq-, PLC-beta-, IP3-, and 5,6-EET-dependent while being prostacyclin-, NO- and K+ channel-independent in HMECs.

Measurement of the flux of ultrahigh energy cosmic rays from monocular observations by the High Resolution Fly's Eye experiment

We have measured the cosmic ray spectrum above 10(17.2) eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode. We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors. We fit the spectrum to a model consisting of galactic and extragalactic sources.

Tumor Necrosis Factor α Activates the Human Plasminogen Activator Inhibitor-1 Gene through a Distal Nuclear Factor κB Site

Plasminogen activator inhibitor-1 (PAI-1) is the major inhibitor of plasminogen activation and likely plays important roles in coronary thrombosis and arteriosclerosis. Tumor necrosis factor-alpha (TNFalpha) is one of many recognized physiological regulators of PAI-1 expression and may contribute to elevated plasma PAI-1 levels in sepsis and obesity. Although TNFalpha is a potent inducer of PAI-1 expression in vitro and in vivo, the precise location of the TNFalpha response site in the PAI-1 promoter has yet to be determined. Transient transfection studies using luciferase reporter constructs containing PAI-1 promoter sequence up to 6.4 kb failed to detect a response to TNFalpha. Moreover, TNFalpha failed to induce expression of enhanced green fluorescent protein under the control of a 2.9-kb human PAI-1 promoter in transgenic mice, although endogenous murine PAI-1 was strongly induced. These data suggested that the TNFalpha response element in the PAI-1 gene is remote from the proximal promoter region. In this study, seven candidate regulatory regions were identified using cross-species sequence homology analysis as well as DNase I-hypersensitive site analysis. We identified a 5' distal TNFalpha-responsive enhancer of the PAI-1 gene located 15 kb upstream of the transcription start site containing a conserved NFkappaB-binding site that mediates the response to TNFalpha. This newly recognized site is fully capable of binding NFkappaB subunits p50 and p65, whereas overexpression of the NFkappaB inhibitor IkappaB prevents TNFalpha-induced activation of this enhancer element.

Tissue- and agonist-specific regulation of human and murine plasminogen activator inhibitor-1 promoters in transgenic mice

Numerous studies have described regulatory factors and sequences that control transcriptional responses in vitro. However, there is a paucity of information on the qualitative and quantitative regulation of heterologous promoters using transgenic strategies. In order to investigate the physiological regulation of human plasminogen activator inhibitor type-1 (hPAI-1) expression in vivo compared to murine PAI-1 (mPAI-1) and to test the physiological relevance of regulatory mechanisms described in vitro, we generated transgenic mice expressing enhanced green fluorescent protein (EGFP) driven by the proximal -2.9 kb of the hPAI-1 promoter. Transgenic animals were treated with Ang II, TGF-beta1 and lipopolysaccharide (LPS) to compare the relative activation of the human and murine PAI-1 promoters. Ang II increased EGFP expression most effectively in brain, kidney and spleen, while mPAI-1 expression was quantitatively enhanced most prominently in heart and spleen. TGF-beta1 failed to induce activation of the hPAI-1 promoter but potently stimulated mPAI-1 in kidney and spleen. LPS administration triggered robust expression of mPAI-1 in liver, kidney, pancreas, spleen and lung, while EGFP was induced only modestly in heart and kidney. These results indicate that the transcriptional response of the endogenous mPAI-1 promoter varies widely in terms of location and magnitude of response to specific stimuli. Moreover, the physiological regulation of PAI-1 expression likely involves a complex interaction of transcription factors and DNA sequences that are not adequately replicated by in vitro functional studies focused on the proximal -2.9 kb promoter.

Regulation of the PAI-1 promoter by circadian clock components: differential activation by BMAL1 and BMAL2

Circadian variation in plasminogen activator inhibitor-1 (PAI-1) production likely contributes to increased risk of myocardial infarction and decreased efficacy of thrombolytic therapy during the morning. In this study, we characterize the abilities of fundamental molecular components of intrinsic circadian clocks to regulate the human PAI-1 promoter in transfected endothelial cells. Both CLOCK:BMAL1 and CLOCK:BMAL2 heterodimers activate the PAI-1 promoter through requisite proximal (-565 to -560 bp) and distal (-680 to -675 bp) E-box enhancers. Although the distal E-box overlaps the 4G/5G polymorphism of the PAI-1 promoter, allelic variation at this site does not influence CLOCK:BMAL1-and CLOCK:BMAL2-mediated transactivation. Together, CLOCK:BMAL1 and CLOCK:BMAL2 make additive contributions to PAI-1 gene transcription. While the abilities of these heterodimers to activate gene expression differ by twofold, the susceptibilities of these circadian activators to inhibition by period and cryptochrome proteins are equivalent and redox independent. Given that BMAL1 and BMAL2 differ in their spatiotemporal distributions, such distinctions may allow intrinsic circadian clocks to modulate the amplitudes of their oscillators, while maintaining circadian periodicity. In this way, fundamental circadian clock components may drive circadian variation in PAI-1, which in turn influences the pathogenesis, timing, and treatment of acute atherothrombotic events.

ACE inhibition versus angiotensin type 1 receptor antagonism: differential effects on PAI-1 over time

ACE inhibition reduces plasminogen activator inhibitor-1 (PAI-1), a risk factor for myocardial infarction, whereas the effect of angiotensin receptor antagonism on PAI-1 is uncertain. The present study compares the time course of effects of ACE inhibition and angiotensin type 1 (AT1) receptor antagonism on morning plasma PAI-1 antigen. Blood pressure and endocrine, metabolic, and fibrinolytic variables were measured in 20 insulin-resistant (defined by fasting glucose >8.3 mmol/L, body mass index >28 kg/m2, or fasting serum triglyceride > or =2.8 mmol/L) hypertensive subjects (mean age, 47.9+/-2.1 years) (1) before and after 1 week of hydrochlorothiazide 12.5 mg/d, and (2) before and 1, 3, 4, and 6 weeks after addition of ramipril (escalated to 10 mg/d) or losartan (escalated to 100 mg/d). Hydrochlorothiazide decreased systolic (P=0.011) and diastolic (P=0.019) pressure. Ramipril (from 133.6+/-5.1/94.5+/-2.4 to 127.0+/-3.1/91.4+/-3.3 mm Hg) or losartan (from 137.0+/-3.9/93.1+/-2.9 to 123.7+/-2.6/86.4+/-2.1 mm Hg) further reduced systolic (P=0.009) and diastolic (P=0.037) pressure. The pressure effects of the 2 drugs were similar. Hydrochlorothiazide increased plasma PAI-1 (P=0.013) but not tissue-type plasminogen activator (tPA) (P=0.431) antigen. Addition of either ramipril or losartan significantly decreased plasma PAI-1 antigen (P=0.046). However, the effect of losartan on PAI-1 antigen was not sustained throughout the 6-week treatment period, such that there was a significant drugxtime interaction (P=0.043). tPA antigen decreased during either ramipril or losartan (P=0.032), but tPA activity decreased only during losartan (P=0.018). Short-term interruption of the renin-angiotensin-aldosterone system by either ACE inhibition or AT1 receptor antagonism decreases PAI-1 antigen, but the duration of this effect is greater for ACE inhibition than for AT1 receptor antagonism.

Age-dependent spontaneous coronary arterial thrombosis in transgenic mice that express a stable form of human plasminogen activator inhibitor-1

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) regulates fibrinolysis and has been reported to be an independent risk factor for ischemic cardiovascular events. This study describes the age-dependent development of spontaneous coronary arterial thrombi that are associated with evidence of subendocardial myocardial infarction in mice transgenic for human PAI-1.

METHODS AND RESULTS

We generated two independent transgenic mice founder lines that express a stable variant of active human PAI-1 under control of the murine preproendothelin-1 (mPPET-1) promoter. Backcrossed homozygous transgenic animals from founder line I had plasma PAI-1 levels of 23+/-12 ng/mL. PAI-1 transgenic animals younger than 4 months do not exhibit any evidence of arterial or venous thrombosis. Ninety percent of transgenic animals (n=10) older than 6 months developed spontaneous occlusions of typically multiple, penetrating coronary arteries, with histological evidence of subendocardial infarction identified in 50% of animals.

CONCLUSIONS

This study shows that chronically elevated levels of PAI-1 are associated with age-dependent coronary arterial thrombosis in mice transgenic for human PAI-1. This is the first study of a murine model of coronary thrombosis that occurs in the absence of severe hypercholesterolemia or multiple genetic manipulations. These findings provide new evidence to support the hypothesis that PAI-1 excess contributes to the development of coronary arterial thrombosis.

Potential roles of plasminogen activator system in coronary vascular remodeling induced by long-term nitric oxide synthase inhibition

Recent studies have indicated that a number of factors contribute to the pathophysiology in response to nitric oxide synthase (NOS) inhibition. We previously demonstrated that plasminogen activator inhibitor-1 deficient (PAI-1-/-) mice are protected against hypertension and perivascular fibrosis induced by relatively short-term NOS inhibition. In this study, we compared the temporal changes in systolic blood pressure and coronary perivascular fibrosis induced by long-term treatment with N(omega)-nitro- L -arginine methyl ester (L -NAME) in wild type (WT), PAI-1(-/-) and tissue-type plasminogen activator deficient (t-PA-/-) mice. After initiating L -NAME, systolic blood pressure increased in all groups at 2 weeks. Over a 16 week study period, systolic blood pressure increased to 143+/-3 mmHg (mean+/-SEM) in WT animals, 139+/-2 in t-PA-/- mice vs 129+/-2 in PAI-1-/- mice (P < 0.01). Coronary perivascular fibrosis increased in L -NAME-treated WT and t-PA(-/-) mice compared to each control group (P<0.01 in WT, P<0.05 in t-PA-/-), while PAI-1-/- mice were protected against fibrosis induced by L -NAME. t-PA deficiency did not accentuate the vascular pathology or the changes in blood pressure. In situ zymography demonstrated augmented gelatinolytic activity in PAI-1-/- mice at baseline, suggesting that PAI-1 deficiency prevents the increase of collagen deposition by promoting matrix degradation. Plasma TGF-beta1 levels increased in L -NAME-treated WT and PAI-1-/- mice (P < 0.01), but not in L -NAME-treated t-PA-/- mice. These findings support the hypothesis that the plasminogen activator system protects against the structural vascular changes induced by long-term NOS inhibition. While PAI-1 deficiency protects against L -NAME-induced hypertension and perivascular fibrosis, t-PA deficiency does not exacerbate the vascular pathology or hypertension.

Ethnicity affects vasodilation, but not endothelial tissue plasminogen activator release, in response to bradykinin

Previous studies indicate that the vasodilator response to bradykinin (BK) and other endothelium-dependent and -independent agonists is decreased in black Americans compared with white Americans. The purpose of the present study was to determine the effect of ethnicity on fibrinolytic function in humans. Graded doses of BK (100, 200, and 400 ng/min), acetylcholine (15, 30, and 60 microg/min; N=20), or methacholine (3.2, 6.4, 12.8 microg/min; N=20), and sodium nitroprusside (0.8, 1.6, and 3.2 microg/min) were infused via brachial artery in 19 white and 21 black age-matched normotensive subjects. Forearm blood flow (FBF) was measured by plethysmography, and venous and arterial samples were collected for tissue plasminogen activator (tPA) antigen. Compared with whites (increase in FBF from 3.7+/-0.5 to 23.9+/-2.5 mL x min(-1) x 100 mL(-1)), blacks (increase in FBF from 2.8+/-0.3 to 15.2+/-1.9 mL x 100 mL(-1) x min(-1)) exhibited a blunted FBF response to BK (P=0.035). Responses to sodium nitroprusside and methacholine or acetylcholine were similarly decreased. In contrast, there was no effect of ethnicity on net tPA antigen release in response to BK (increase from -0.2+/-0.4 to 67.3+/-15.2 ng x min(-1) x 100 mL(-1) in blacks; from 0.04+/-0.9 to 65.9+/-13.6 ng x min(-1) x 100 mL(-1) in whites). Thus, ethnicity significantly influenced the relationship between the flow and tPA release responses to BK (P=0.037). These data suggest that the BK-dependent alterations in vascular fibrinolytic function are preserved in black Americans compared with white Americans.

EXP3174, the AII antagonist human metabolite of losartan, but not losartan nor the angiotensin-converting enzyme inhibitor captopril, prevents the development of lethal ischemic ventricular arrhythmias in a canine model of recent myocardial infarction

OBJECTIVES

The antiarrhythmic efficacies of the competitive angiotensin II (AII) antagonist losartan, losartan's more potent noncompetitive AII antagonist human metabolite EXP3174 and the angiotensin-converting enzyme inhibitor captopril were assessed in a canine model of recent myocardial infarction.

BACKGROUND

Multiple hemodynamic and electrophysiologic effects of AII may contribute to cardiac electrical instability. In the recent Losartan Heart Failure Study, Evaluation of Losartan in the Elderly (ELITE), a 722-patient trial primarily designed to assess effects on renal function, an unexpected survival benefit was observed with losartan compared with captopril, with the lower mortality using losartan primarily confined to a reduction in sudden cardiac death.

METHODS

Intravenous losartan (1 mg/kg + 0.03 mg/kg/min), EXP3174 (0.1 mg/kg + 0.01 mg/kg/min), captopril (1 mg/kg + 0.5 mg/kg/h) or vehicle were infused in anesthetized dogs with recent (8.1 +/- 0.4 days) anterior myocardial infarction. Electrolytic injury of the left circumflex coronary artery to induce thrombotic occlusion and posterolateral ischemia was initiated 1 h after the start of treatment.

RESULTS

Losartan, EXP3174 and captopril elevated plasma renin activities and comparably and significantly reduced mean arterial pressure. No significant electrocardiographic or cardiac electrophysiologic effects were noted with any treatment. Incidences of acute posterolateral ischemia-induced lethal arrhythmias were: vehicle, 7/9 (77%); losartan, 6/8 (75%); EXP3174, 2/8 (25%; p < 0.05 vs. vehicle control); captopril, 7/10 (70%). There were no among-group differences in time to onset of acute posterolateral ischemia or underlying anterior infarct size.

CONCLUSIONS

EXP3174, but not losartan nor captopril, reduced the incidence of lethal ischemic ventricular arrhythmia in this preparation. The antiarrhythmic efficacy of EXP3174 may be due to an attenuation of deleterious effects of local cardiac AII formed during acute myocardial ischemia or, alternatively, a non-AII-related activity specific to EXP3174. These findings suggest that in humans, metabolic conversion of losartan to EXP3174 may afford antiarrhythmic protection.