Sugar is not always sweet: exploring the relationship between hyperglycemia and COVID-19 in a predominantly African American population

INTRODUCTION

The purpose of this study is to examine the effect of admission glucose in patients hospitalized with COVID-19 with and without diabetes mellitus in a largely African American cohort.

DESIGN AND METHODS

This study included 708 adults (89% non-Hispanic Black) admitted with COVID-19 to an urban hospital between 1 March and 15 May 2020. Patients with diabetes were compared with those without and were stratified based on admission glucose of 140 and 180 mg/dL. Adjusted ORs were calculated for outcomes of mortality, intubation, intensive care unit (ICU) admission, acute kidney injury (AKI), and length of stay based on admission glucose levels.

RESULTS

Patients with diabetes with admission glucose >140 mg/dL (vs <140 g/dL) had 2.4-fold increased odds of intubation (95% CI 1.2 to 4.6) and 2.1-fold increased odds of ICU admission (95% CI 1.0 to 4.3). Patients with diabetes with admission glucose >180 mg/dL (vs <180 g/dL) had a 1.9-fold increased mortality (95% CI 1.2 to 3.1). Patients without diabetes with admission glucose >140 mg/dL had a 2.3-fold increased mortality (95% CI 1.3 to 4.3), 2.7-fold increased odds of ICU admission (95% CI 1.3 to 5.4), 1.9-fold increased odds of intubation (95% CI 1.0 to 3.7) and 2.2-fold odds of AKI (95% CI 1.1 to 3.8). Patients without diabetes with glucose >180 mg/dL had 4.4-fold increased odds of mortality (95% CI 1.9 to 10.4), 2.7-fold increased odds of intubation (95% CI 1.2 to 5.8) and 3-fold increased odds of ICU admission (95% CI 1.3 to 6.6).

CONCLUSION

Our results show hyperglycemia portends worse outcomes in patients with COVID-19 with and without diabetes. While our study was limited by its retrospective design, our findings suggest that patients presenting with hyperglycemia require closer observation and more aggressive therapies.

Sugar Is Not Always Sweet: Exploring the Relationship Between Hyperglycemia and COVID-19 in a Predominantly African American Population

Introduction: A relationship between hyperglycemia and outcomes in patients with COVID-19 has been proposed, however there is a paucity of literature on this. In this study, we examined the effect of admission glucose in diabetics and non-diabetics on outcomes in patients hospitalized with COVID-19. Our study uniquely examines this association in a largely African American cohort, a population disproportionately affected by COVID-19.

Methods: In this retrospective cohort study, we analyzed all adults admitted with COVID-19 to a designated COVID hospital in Brooklyn, NY from March 1 to May 15, 2020. Diabetics were compared to non-diabetics, and were further stratified based on admission glucoses of 140 and 180 mg/dL. Diagnosis of diabetes was based on history and/or Hba1c > 6.5%. Univariate, multiple and logistic regressions were used for analyses, examining outcomes of mortality, intubation, ICU admission, acute kidney injury (AKI), and length of stay based on admission glucose levels, while controlling for age, gender, lab values (serum creatinine and WBC), and comorbidities including hypertension, cardiovascular disease, and obesity. Outcomes are presented as an adjusted odds ratio (OR) with 95% confidence interval (95% CI).

Results: 708 patients were analyzed; 54% diabetics, 83.5% non-Hispanic Blacks, 51% male with a mean age of 68, BMI of 29 kg/m² and crude mortality rate of 40%. The length of hospital stay was greater in diabetics than non-diabetics, (13±26 days vs 9.5±18.5 days, p<0.05). Diabetics with an admission glucose > 140 mg/dL (vs<140 g/dL) had a 2.4-fold increased odds of both intubation and ICU admission (95% CI: 1.2, 4.5; 1.3, 4.6). Diabetics with admission glucoses > 180 mg/dL (vs <180 g/dL) had a 1.8-fold increased mortality (95% CI: 1.2, 2.9). Non-diabetics with admission glucoses >140 mg/dL (vs<140 g/dL) had a two-fold increased mortality (95% CI: 1.2, 3.5), 3.5-fold increased odds of ICU admission (95% CI: 1.8,6.6) and a 2.3-fold increased odds of both intubation and AKI (95% CI: 1.3, 4.2; 1.3,4.2). Non-diabetics with a glucose >180 mg/dL (vs <180 g/dL) had a four-fold increased mortality (95% CI: 1.8, 8.8), 2.7-fold increased odds of intubation (95% CI: 1.3, 5.6) and 2.9-fold increased odds of ICU admission (95% CI: 1.3, 6.2).

Conclusion: Our results show hyperglycemia portends worse outcomes in diabetics and non-diabetics with COVID-19. Elevated admitting glucoses >180 mg/dL increased odds of mortality four-fold in non-diabetics and 1.8- fold in diabetics. In COVID-19, diabetic patients had a 37% greater length of hospital stay than non-diabetics. Whether hyperglycemia is a marker or a cause of more severe COVID-19 is unknown. These findings suggest that patients presenting with hyperglycemia require closer observation and more aggressive therapies. This raises the testable hypothesis that intensive glucose control may improve outcomes in patients with COVID-19.

The glycan CA19-9 promotes pancreatitis and pancreatic cancer in mice

Glycosylation alterations are indicative of tissue inflammation and neoplasia, but whether these alterations contribute to disease pathogenesis is largely unknown. To study the role of glycan changes in pancreatic disease, we inducibly expressed human fucosyltransferase 3 and β1,3-galactosyltransferase 5 in mice, reconstituting the glycan sialyl-Lewis^a, also known as carbohydrate antigen 19-9 (CA19-9). Notably, CA19-9 expression in mice resulted in rapid and severe pancreatitis with hyperactivation of epidermal growth factor receptor (EGFR) signaling. Mechanistically, CA19-9 modification of the matricellular protein fibulin-3 increased its interaction with EGFR, and blockade of fibulin-3, EGFR ligands, or CA19-9 prevented EGFR hyperactivation in organoids. CA19-9-mediated pancreatitis was reversible and could be suppressed with CA19-9 antibodies. CA19-9 also cooperated with the Kras^G12D oncogene to produce aggressive pancreatic cancer. These findings implicate CA19-9 in the etiology of pancreatitis and pancreatic cancer and nominate CA19-9 as a therapeutic target.

eIF4A supports an oncogenic translation program in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy with limited treatment options. Although metabolic reprogramming is a hallmark of many cancers, including PDA, previous attempts to target metabolic changes therapeutically have been stymied by drug toxicity and tumour cell plasticity. Here, we show that PDA cells engage an eIF4F-dependent translation program that supports redox and central carbon metabolism. Inhibition of the eIF4F subunit, eIF4A, using the synthetic rocaglate CR-1-31-B (CR-31) reduced the viability of PDA organoids relative to their normal counterparts. In vivo, CR-31 suppresses tumour growth and extends survival of genetically-engineered murine models of PDA. Surprisingly, inhibition of eIF4A also induces glutamine reductive carboxylation. As a consequence, combined targeting of eIF4A and glutaminase activity more effectively inhibits PDA cell growth both in vitro and in vivo. Overall, our work demonstrates the importance of eIF4A in translational control of pancreatic tumour metabolism and as a therapeutic target against PDA.

Abstract A27: Exploring the role of glycosylation in pancreatic disease

Pancreatic ductal adenocarcinoma (PDA) is almost uniformly lethal and surgical intervention is the only cure. Unfortunately, most patients are ineligible for resection because of the advanced stage of disease by the time of diagnosis. This is due in part to the lack of diagnostic tools, especially for families with elevated risk. The PDA biomarker, CA19-9, is measured in the blood to follow tumor burden longitudinally, but is neither sensitive nor specific enough to be used for diagnosis. The use of CA19-9 in PDA diagnosis is problematic given the elevation of CA19-9 in benign pancreatic disease, such as pancreatitis.

While CA19-9 has been traditionally used as a diagnostic, retrospective studies reported that PDA patients who maintain a CA19-9 negative/low status have a significantly longer survival relative to those with higher CA19-9 levels in multivariate analyses. The functional significance of CA19-9 to PDA initiation, maintenance, and progression remains unclear due in part to the absence of this carbohydrate modification in mice. We found that expression of CA19-9 in the mouse pancreas is sufficient to induce pancreatitis, a benign proliferative condition that often confounds the diagnosis of PDA. Specifically, CA19-9 elevation resulted in rapid elevation of pancreatic enzymes in the blood, pancreatic infiltration of immune cells, acinar-to-ductal metaplasia and atrophy, as well as increased proliferation. Furthermore, we explored the utility of CA19-9 as a therapeutic target for both acute and chronic pancreatitis. This avenue of treatment strategy exhibits potential given that a pilot study demonstrated that turning off CA19-9 expression results in the normalization of pancreatic enzyme levels within four days following an acute episode of pancreatitis.

Future work will focus on how elevation of this glycosylation modification mediates the development of pancreatitis by identifying the signaling pathways that are altered upon CA19-9 expression. In addition, we will explore the efficacy of therapeutically targeting CA19-9 in both pancreatitis and PDA with a larger goal of delineating the role of CA19-9 in pancreatic disease.

Citation Format: Dannielle Engle, Hervé Tiriac, Arnaud Pommier, Christina Schoepfer, Brandon Da Silva, Melissa Yao, Youngkyu Park, Michael A. Hollingsworth, David Tuveson. Exploring the role of glycosylation in pancreatic disease [abstract]. In: Proceedings of the AACR Special Conference: Advances in Modeling Cancer in Mice: Technology, Biology, and Beyond; 2017 Sep 24-27; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(10 Suppl):Abstract nr A27.

Enhancer Reprogramming Promotes Pancreatic Cancer Metastasis

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal human malignancies, owing in part to its propensity for metastasis. Here, we used an organoid culture system to investigate how transcription and the enhancer landscape become altered during discrete stages of disease progression in a PDA mouse model. This approach revealed that the metastatic transition is accompanied by massive and recurrent alterations in enhancer activity. We implicate the pioneer factor FOXA1 as a driver of enhancer activation in this system, a mechanism that renders PDA cells more invasive and less anchorage-dependent for growth in vitro, as well as more metastatic in vivo. In this context, FOXA1-dependent enhancer reprogramming activates a transcriptional program of embryonic foregut endoderm. Collectively, our study implicates enhancer reprogramming, FOXA1 upregulation, and a retrograde developmental transition in PDA metastasis.

Abstract 1027: Development of orthotopically grafted organoid models to study pancreatic cancer progression

Pancreatic ductal adenocarcinoma (PDA) is one of the most difficult human malignancies to treat. The 5-year survival rate of PDA patients is 7% and PDA is predicted to become the second leading cancer-related cause of death in the USA. A subset of potential tumor suppressor genes was identified by genome-wide analysis of human PDA and insertional mutagenesis in genetically engineered mouse models (GEMMs). Since the functional validation of these genes in GEMMs is time-consuming and labor-intensive, we have developed a rapid and efficient ‘orthotopically grafted organoid’ (OGO) models in conjunction with RNAi and CRISPR/Cas9 technology to study PDA progression. Previously, we showed that OGO model represents the full spectrum of PDA progression in vivo upon orthotopic engraftment. Here, as a proof-of-concept experiment, we demonstrate that ablation of Trp53 by viral introduction of shRNA or gRNA in PanIN-derived organoids accelerates PDA progression upon transplantation. In addition, we engineered tetracyclin-inducible shRNA against Trp53 in ColA1 locus by Flpe recombinase-mediated cassette exchange in organoids derived from Kras +/G12D ; Rosa26-rtTA ; ColA1-homing cassette mouse. Orthotopic transplantation followed by doxycycline administration resulted in rapid PDA progression with metastases. Isolated tumor organoids were re-transplanted to evaluate the effect of p53 restoration in PDA progression. Restoration of p53 by doxycycline withdrawal led to reduced liver metastases, although there was no difference in survival and primary tumor growth. This will provide a new insight how p53 regulates PDA metastasis. Therefore, OGO models should provide an excellent platform to study the functional role of genes in PDA progression in vivo.

Citation Format: Chang-Il Hwang, Eunjung Lee, Brandon Da Silva, Kevin Wright, Youngkyu Park, David A. Tuveson. Development of orthotopically grafted organoid models to study pancreatic cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1027. doi:10.1158/1538-7445.AM2017-1027

NRF2 Promotes Tumor Maintenance by Modulating mRNA Translation in Pancreatic Cancer

Pancreatic cancer is a deadly malignancy that lacks effective therapeutics. We previously reported that oncogenic Kras induced the redox master regulator Nfe2l2/Nrf2 to stimulate pancreatic and lung cancer initiation. Here, we show that NRF2 is necessary to maintain pancreatic cancer proliferation by regulating mRNA translation. Specifically, loss of NRF2 led to defects in autocrine epidermal growth factor receptor (EGFR) signaling and oxidation of specific translational regulatory proteins, resulting in impaired cap-dependent and cap-independent mRNA translation in pancreatic cancer cells. Combined targeting of the EGFR effector AKT and the glutathione antioxidant pathway mimicked Nrf2 ablation to potently inhibit pancreatic cancer ex vivo and in vivo, representing a promising synthetic lethal strategy for treating the disease.

Abstract 2733: Development of novel monoclonal antibodies for a cyclic DNA adduct derived from oxidation of ω-6 polyunsaturated fatty acids

Dietary polyunsaturated fatty acids (ω-3 and ω-6 PUFAs) play a role in certain human cancers. The oxidation of PUFAs produces reactive α,β-unsaturated aldehydes (enals) that can modify DNA producing mutagenic lesions. Of particular interest, 7-(1′,2′-dihydroxyheptyl)-1,N6- ethenodeoxyadenosine (DHHϵdA) is a novel DNA adduct in vitro and in vivo derived from lipid peroxidation of ω-6 PUFAs. Despite its recent identification in vivo, the role of DHHϵdA in tumorigenesis is not yet known. Previously, the endogenously formed DHHϵdA was detected by liquid chromatography tandem mass spectrometry (LC-MS/MS). Due to its low levels in vivo (1-30 adducts/109 DNA bases), a relatively high quantity of DNA is needed for its detection and quantification. In this study we developed a monoclonal antibody against DHHϵdA in order to detect and quantify this adduct in cells and tissues. Two antigens were synthesized by conjugating activated hapten: 5′-carboxy-7-(1′,2′-dihydroxyheptyl) adenosine (5′-carboxy DHHϵA) to BSA and KLH carrier proteins. KLH-conjugated hapten was used for mice immunization, whereas BSA-based hapten was used to test for an immune response. After immunization and several screenings, 6 monoclonal cell lines were chosen for further tests. Normal and competitive ELISA was performed to characterize the antibodies from all cell lines. Competitive ELISA revealed no cross-reactivity towards normal nucleosides and α- and γ-OHPdG, the cyclic 1,N2-propano adduct derived from acrolein, and 8-oxo-dG for all of the tested antibodies. However, we observed a weak (&lt; 1:100) specificity for HNE-dG, an adduct derived from (E)-4-hydroxy-2-nonenal produced from oxidized ω-6 PUFAs. Because of the relatively low level of endogenous HNE-dG compared to DHHϵdA, this weak cross-reactivity should not affect the specificity of the developed antibody to detect DHHϵdA. Two cell lines were discarded after antibodies from them showed moderate competitive effects against 1,N6-etheno-2′-deoxyadenosine (ϵdA). From the remaining 4 cell lines the best one was chosen to produce purified antibody. We believe that this antibody will be a useful tool in the studies of the role of DHHϵdA as an endogenous DNA lesion in cancer development associated with ω-6 PUFAs. This work was supported by the NCI grant CA134892.

Citation Format: Marcin Dyba, Brandon Da Silva, Jishen Pan, Fung-Lung Chung. Development of novel monoclonal antibodies for a cyclic DNA adduct derived from oxidation of ω-6 polyunsaturated fatty acids. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2733. doi:10.1158/1538-7445.AM2015-2733