Pharmacological Characterization of SDX-7320/Evexomostat: A Novel Methionine Aminopeptidase Type 2 Inhibitor with Anti-tumor and Anti-metastatic Activity

Methionine aminopeptidase type 2 (METAP2) is a ubiquitous, evolutionarily conserved metalloprotease fundamental to protein biosynthesis which catalyzes removal of the N-terminal methionine residue from nascent polypeptides. METAP2 is an attractive target for cancer therapeutics based upon its over-expression in multiple human cancers, the importance of METAP2-specific substrates whose biological activity may be altered following METAP2 inhibition, and additionally, that METAP2 was identified as the target for the anti-angiogenic natural product, fumagillin. Irreversible inhibition of METAP2 using fumagillin analogues has established the anti-angiogenic and anti-tumor characteristics of these derivatives; however, their full clinical potential has not been realized due to a combination of poor drug-like properties and dose-limiting central nervous system (CNS) toxicity. This report describes the physicochemical and pharmacological characterization of SDX-7320 (evexomostat), a polymer-drug conjugate of the novel METAP2 inhibitor (METAP2i) SDX-7539. In vitro binding, enzyme, and cell-based assays demonstrated that SDX-7539 is a potent and selective METAP2 inhibitor. In utilizing a high molecular weight, water-soluble polymer to conjugate the novel fumagillol-derived, cathepsin-released, METAP2i SDX-7539, limitations observed with prior generation, small molecule fumagillol derivatives were ameliorated including reduced CNS exposure of the METAP2i, and prolonged half-life enabling convenient administration. Multiple xenograft and syngeneic cancer models were utilized to demonstrate the anti-tumor and anti-metastatic profile of SDX-7320. Unlike polymer-drug conjugates in general, reductions in small molecule-equivalent efficacious doses following polymer conjugation were observed. SDX-7320 has completed a phase I clinical safety study in patients with late-stage cancer and is currently being evaluated in multiple phase Ib/II clinical studies in patients with advanced solid tumors.

Associations of Lifestyle and Genetic Risks with Obesity and Related Chronic Diseases in the UK Biobank: A Prospective Cohort Study

BACKGROUND

Interplay between lifestyle risk scores (LRSs) and genetic risk scores (GRSs) on obesity and related chronic diseases are underinvestigated and necessary for understanding obesity causes and developing prevention strategies.

OBJECTIVES

This study aimed to investigate independent and joint associations and interactions of LRS and GRS with obesity prevalence and risks of diabetes, cardiovascular disease (CVD), and obesity-related cancer.

METHODS

In this cohort study of 444,957 UK Biobank participants [age: 56.5 ± 8.1 y; BMI (in kg/m2): 27.4 ± 4.7], LRS included physical activity, dietary score, sedentary behavior, sleep duration, and smoking (range: 0-20, each factor had 5 levels). GRS was calculated based on 941 genetic variants related to BMI. Both scores were categorized into quintiles. Obesity (n = 106,301) was defined as baseline BMI ≥30. Incident diabetes (n = 16,311), CVD (n = 18,076), and obesity-related cancer (n = 17,325) were ascertained through linkage to registries over a median of 12-y follow-up.

RESULTS

The LRS and GRS were independently positively associated with all outcomes. Additive interactions of LRS and GRS were observed for all outcomes (P < 0.021). Comparing the top with bottom LRS quintile, prevalence differences (95% CIs) for obesity were 17.8% (15.9%, 19.7%) in the top GRS quintile and 10.7% (8.3%, 13.1%) in the bottom GRS quintile; for diabetes, CVD, and obesity-related cancer, incidence rate differences associated with per SD increase in LRS were greater in the top than that in the bottom GRS quintile. Participants from top quintiles of both LRS and GRS had 6.16-fold, 3.81-fold, 1.56-fold, and 1.44-fold higher odds/risks of obesity, diabetes, CVD, and obesity-related cancer, respectively, than those from bottom quintiles of both scores.

CONCLUSIONS

Higher LRS was associated with higher obesity prevalence and risks of related chronic diseases regardless of GRS, highlighting the broad benefits of healthy lifestyles. Additive gene-lifestyle interactions emphasize the public health importance of lifestyle interventions among people with high genetic risks.

A randomized, double-blind, placebo-controlled phase 2 study to assess safety, tolerability, and efficacy of RT001 in patients with amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

RT001 is a deuterated synthetic homologue of linoleic acid, which makes membrane polyunsaturated fatty acids resistant to lipid peroxidation, a process involved in motor neuron degeneration in amyotrophic lateral sclerosis (ALS).

METHODS

We conducted a randomized, multicenter, placebo-controlled clinical trial. Patients with ALS were randomly allocated to receive either RT001 or placebo for 24 weeks. After the double-blind period, all patients received RT001 during an open-label phase for 24 weeks. The primary outcome measures were safety and tolerability. Key efficacy outcomes included the ALS Functional Rating Scale (ALSFRS-R), percent predicted slow vital capacity, and plasma neurofilament light chain concentration.

RESULTS

In total, 43 patients (RT001 = 21; placebo = 22) were randomized. RT001 was well tolerated; one patient required dose reduction due to adverse events (AEs). Numerically, there were more AEs in the RT001 group compared to the placebo group (71% versus 55%, p = 0.35), with gastrointestinal symptoms being the most common (43% in RT001, 27% in placebo, p = 0.35). Two patients in the RT001 group experienced a serious AE, though unrelated to treatment. The least-squares mean difference in ALSFRS-R total score at week 24 of treatment was 1.90 (95% confidence interval = -1.39 to 5.19) in favor of RT001 (p = 0.25). The directions of other efficacy outcomes favored RT001 compared to placebo, although no inferential statistics were performed.

CONCLUSIONS

Initial data indicate that RT001 is safe and well tolerated. Given the exploratory nature of the study, a larger clinical trial is required to evaluate its efficacy.

Obesity alters monocyte developmental trajectories to enhance metastasis

Obesity is characterized by chronic systemic inflammation and enhances cancer metastasis and mortality. Obesity promotes breast cancer metastasis to lung in a neutrophil-dependent manner; however, the upstream regulatory mechanisms of this process remain unknown. Here, we show that obesity-induced monocytes underlie neutrophil activation and breast cancer lung metastasis. Using mass cytometry, obesity favors the expansion of myeloid lineages while restricting lymphoid cells within the peripheral blood. RNA sequencing and flow cytometry revealed that obesity-associated monocytes resemble professional antigen-presenting cells due to a shift in their development and exhibit enhanced MHCII expression and CXCL2 production. Monocyte induction of the CXCL2-CXCR2 axis underlies neutrophil activation and release of neutrophil extracellular traps to promote metastasis, and enhancement of this signaling axis is observed in lung metastases from obese cancer patients. Our findings provide mechanistic insight into the relationship between obesity and cancer by broadening our understanding of the interactive role that myeloid cells play in this process.

Healthy Lifestyle Index and Risk of Cardiovascular Disease Among Postmenopausal Women With Normal Body Mass Index

Background A lifestyle comprising a healthy diet, light alcohol consumption, no smoking, and moderate or intense physical activity has been associated with reduced risk of cardiovascular disease (CVD). We examined the association of a healthy lifestyle index (HLI), derived from scores for each of these components plus waist circumference, with the risk of incident CVD and CVD subtypes in postmenopausal women with normal body mass index (18.5-<25.0 kg/m²). Methods and Results We studied 40 118 participants in the Women's Health Initiative, aged 50 to 79 years at enrollment, with a normal body mass index and no history of CVD. The HLI score was categorized into quintiles. We estimated multivariable adjusted hazard ratios (HR) and 95% CIs for the association of HLI with risk of CVD and CVD subtypes using Cox regression models. A total of 3821 cases of incident CVD were ascertained during a median follow-up of 20.1 years. Compared with the lowest quintile (unhealthiest lifestyle), higher HLI quintiles showed inverse associations with the risk of CVD (HR_quintile-2=0.74 [95% CI, 0.67-0.81]; HR_quintile-3=0.66 [95% CI, 0.60-0.72]; HR_quintile-4=0.57 [95% CI, 0.51-0.63]; and HR_quintile-5=0.48 [95% CI, 0.43-0.54], P-trend=<0.001). HLI was also inversely associated with risks of stroke, coronary heart disease, myocardial infarction, angina, and coronary revascularization. Subgroup analyses, stratified by age (≤63 years vs >63 years), body mass index (</≥ 22.0 kg/m²), and general health status (absence/presence of hypertension, diabetes, or lipid-lowering drug use) also showed inverse associations between HLI and risk of CVD. Conclusions Among postmenopausal women with a normal body mass index, adherence to a healthy lifestyle is associated with a reduced risk of clinical CVD and CVD subtypes, underscoring the cardiovascular benefits of maintaining a healthy lifestyle, even for women with a healthy weight.

Submitochondrial Protein Translocation Upon Stress Inhibits Thermogenic Energy Expenditure

Mitochondria-rich brown adipocytes dissipate cellular fuel as heat by thermogenic energy expenditure (TEE). Prolonged nutrient excess or cold exposure impair TEE and contribute to the pathogenesis of obesity, but the mechanisms remain incompletely understood. Here we report that stress-induced proton leak into the matrix interface of mitochondrial innermembrane (IM) mobilizes a group of proteins from IM into matrix, which in turn alter mitochondrial bioenergetics. We further determine a smaller subset that correlates with obesity in human subcutaneous adipose tissue. We go on to show that the top factor on this short list, acyl-CoA thioesterase 9 (ACOT9), migrates from the IM into the matrix upon stress where it enzymatically deactivates and prevents the utilization of acetyl-CoA in TEE. The loss of ACOT9 protects mice against the complications of obesity by maintaining unobstructed TEE. Overall, our results introduce aberrant protein translocation as a strategy to identify pathogenic factors.

One-Sentence Summary

Thermogenic stress impairs mitochondrial energy utilization by forcing translocation of IM-bound proteins into the matrix.

Translating energy balance research from the bench to the clinic to the community: Parallel animal-human studies in cancer

Advances in energy balance and cancer research to date have largely occurred in siloed work in rodents or patients. However, substantial benefit can be derived from parallel studies in which animal models inform the design of clinical and population studies or in which clinical observations become the basis for animal studies. The conference Translating Energy Balance from Bench to Communities: Application of Parallel Animal-Human Studies in Cancer, held in July 2021, convened investigators from basic, translational/clinical, and population science research to share knowledge, examples of successful parallel studies, and strong research to move the field of energy balance and cancer toward practice changes. This review summarizes key topics discussed to advance research on the role of energy balance, including physical activity, body composition, and dietary intake, on cancer development, cancer outcomes, and healthy survivorship.

Microbes Contribute to Chemopreventive Efficacy, Intestinal Tumorigenesis, and the Metabolome

Bacteria are believed to play an important role in intestinal tumorigenesis and contribute to both gut luminal and circulating metabolites. Celecoxib, a selective cyclooxygenase-2 inhibitor, alters gut bacteria and metabolites in association with suppressing the development of intestinal polyps in mice. The current study sought to evaluate whether celecoxib exerts its chemopreventive effects, in part, through intestinal bacteria and metabolomic alterations. Using ApcMin/+ mice, we demonstrated that treatment with broad-spectrum antibiotics (ABx) reduced abundance of gut bacteria and attenuated the ability of celecoxib to suppress intestinal tumorigenesis. Use of ABx also impaired celecoxib's ability to shift microbial populations and gut luminal and circulating metabolites. Treatment with ABx alone markedly reduced tumor number and size in ApcMin/+ mice, in conjunction with profoundly altering the metabolite profiles of the intestinal lumen and blood. Many of the metabolite changes in the gut and circulation overlapped and included shifts in microbially derived metabolites. To complement these findings in mice, we evaluated the effects of ABx on circulating metabolites in patients with colon cancer. This showed that ABx treatment led to a shift in blood metabolites, including several that were of bacterial origin. Importantly, changes in metabolites in patients given ABx overlapped with alterations found in mice that also received ABx. Taken together, these findings suggest a potential role for bacterial metabolites in mediating both the chemopreventive effects of celecoxib and intestinal tumor growth.

PREVENTION RELEVANCE

This study demonstrates novel mechanisms by which chemopreventive agents exert their effects and gut microbiota impact intestinal tumor development. These findings have the potential to lead to improved cancer prevention strategies by modulating microbes and their metabolites.

Weight Loss and/or Sulindac Mitigate Obesity-associated Transcriptome, Microbiome, and Protumor Effects in a Murine Model of Colon Cancer

Obesity is associated with an increased risk of colon cancer. Our current study examines whether weight loss and/or treatment with the NSAID sulindac suppresses the protumor effects of obesity in a mouse model of colon cancer. Azoxymethane-treated male FVB/N mice were fed a low-fat diet (LFD) or high-fat diet (HFD) for 15 weeks, then HFD mice were randomized to remain on HFD (obese) or switch to LFD [formerly obese (FOb-LFD)]. Within the control (LFD), obese, and FOb-LFD groups, half the mice started sulindac treatment (140 ppm in the diet). All mice were euthanized 7 weeks later. FOb-LFD mice had intermediate body weight levels, lower than obese but higher than control (P < 0.05). Sulindac did not affect body weight. Obese mice had greater tumor multiplicity and burden than all other groups (P < 0.05). Transcriptomic profiling indicated that weight loss and sulindac each modulate the expression of tumor genes related to invasion and may promote a more antitumor immune landscape. Furthermore, the fecal microbes Coprobacillus, Prevotella, and Akkermansia muciniphila were positively correlated with tumor multiplicity and reduced by sulindac in obese mice. Coprobacillus abundance was also decreased in FOb-LFD mice. In sum, weight loss and sulindac treatment, alone and in combination, reversed the effects of chronic obesity on colon tumor multiplicity and burden. Our findings suggest that an investigation regarding the effects of NSAID treatment on colon cancer risk and/or progression in obese individuals is warranted, particularly for those unable to achieve moderate weight loss.

PREVENTION RELEVANCE

Obesity is a colon cancer risk and/or progression factor, but the underlying mechanisms are incompletely understood. Herein we demonstrate that obesity enhances murine colon carcinogenesis and expression of numerous tumoral procancer and immunosuppressive pathways. Moreover, we establish that weight loss via LFD and/or the NSAID sulindac mitigate procancer effects of obesity.

High-Fat Diet-Induced Obesity Alters Dendritic Cell Homeostasis by Enhancing Mitochondrial Fatty Acid Oxidation

Obesity is associated with increased cancer risk and weak responses to vaccination and sepsis treatment. Although dendritic cells (DCs) are fundamental for the initiation and maintenance of competent immune responses against pathogens and tumors, how obesity alters the normal physiology of these myeloid cells remains largely unexplored. In this study, we report that obesity caused by prolonged high-fat diet feeding disrupts the metabolic and functional status of mouse splenic DCs (SpDCs). High-fat diet-induced obesity drastically altered the global transcriptional profile of SpDCs, causing severe changes in the expression of gene programs implicated in lipid metabolism and mitochondrial function. SpDCs isolated from obese mice demonstrated enhanced mitochondrial respiration provoked by increased fatty acid oxidation (FAO), which drove the intracellular accumulation of reactive oxygen species that impaired Ag presentation to T cells. Accordingly, treatment with the FAO inhibitor etomoxir, or antioxidants such as vitamin E or N-acetyl-l-cysteine, restored the Ag-presenting capacity of SpDCs isolated from obese mice. Our findings reveal a major detrimental effect of obesity in DC physiology and suggest that controlling mitochondrial FAO or reactive oxygen species overproduction may help improve DC function in obese individuals.

Cancer and cardiovascular-related perceived risk in a diverse cancer center catchment area

Purpose

Despite cancer and cardiovascular disease (CVD) sharing several modifiable risk factors, few unified prevention efforts exist. We sought to determine the association between risk perception for cancer and CVD and engagement in healthy behaviors.

Methods

Between May 2019 and August 2020, we conducted a cross-sectional survey of adults ≥ 40 years residing in Brooklyn neighborhoods with high cancer mortality. We considered one’s perceived risk of cancer and CVD compared to age counterparts as the primary exposures. The primary study outcome was a weighted health behavior score (wHBS) composed of 5 domains: physical activity, no obesity, no smoking, low alcohol intake, and healthy diet. Modified Poisson regression models with robust error variance were used to assess associations between perceived risk for cancer and CVD and the wHBS, separately.

Results

We surveyed 2448 adults (mean [SD] age, 61.4 [12.9] years); 61% female, 30% Non-Hispanic White, and 70% racial/ethnic minorities. Compared to their age counterparts nearly one-third of participants perceived themselves to be at higher CVD or cancer risk. Perceiving higher CVD risk was associated with an 8% lower likelihood of engaging in healthy behaviors (RR 0.92; 95% CI 0.86–0.99). Perceiving greater cancer risk was associated with a 14% lower likelihood of engaging in healthy behaviors (RR 0.86; 95% CI 0.79–0.95). The association between cancer risk and wHBS attenuated but remained significant (aRR 0.90; 95% CI 0.82–0.98) after adjustment.

Conclusion

Identifying high-risk subgroups and intervening on shared risk behaviors could have the greatest long-term impact on reducing CVD and cancer morbidity and mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10552-022-01560-3.

Abstract P2-08-05: Plasma lipidomics analysis to identify potential non-invasive biomarkers for breast white adipose inflammation and aromatase expression levels

Background: The presence of white adipose tissue inflammation (WATi) in the breast has been associated with increased breast cancer risk and a worse clinical course. Elevated body mass index (BMI) and the post-menopausal state are both associated with breast WATi. Breast WATi has also been associated with increased expression of aromatase, the rate-limiting enzyme for estrogen biosynthesis. Currently, WATi is diagnosed in surgical samples of breast tissue by the identification of crown-like structures (CLS), which are comprised of a dead or dying adipocyte enveloped by macrophages. In contrast to surgical specimens, core biopsies have been shown to be inadequate for assessing WATi. Hence, there is an unmet need for strategies to non-invasively diagnose WATi. Here we used a novel lipidomics platform to identify potential non-invasive blood signatures of breast WATi. Methods: We conducted a cross-sectional study which included 100 patients who underwent mastectomy for breast cancer treatment or risk reduction. WATi was detected by CD68 immunohistochemistry to identify CLS. Breast aromatase expression levels were measured by qPCR. Clinicopathologic data were abstracted from electronic medical records. Lipidomic data were measured from blood plasma in collaboration with Waters Technologies Corporation. Lipid levels in association with breast WATi (presence/absence) and levels of aromatase expression (high/low) in non-tumorous breast tissue were examined using Welch’s t-test. P-values were adjusted for multiple comparisons by controlling the false discovery rate (FDR) using the Benjamini-Hochberg method. A logistic regression model was used to develop predictive models that evaluated potential lipid biomarkers of the presence of breast WATi and high breast aromatase expression levels. Stepwise regression was used for variable selection. AUC of the ROC curves was used to evaluate the performance of the predictive models. Results: Among 140 lipids analyzed, 13 were identified to be associated with breast WATi (P&lt;0.05, |log2FC|&gt;0.3). Specifically, 8 lipids had lower levels, and 6 lipids had higher levels in patients with breast WATi compared to those without. Levels of 7 lipids were significantly higher in patients with an increased level of aromatase (P&lt;0.05, |log2FC|&gt;0.3). After variable selection, LPE(22:6) (P=0.018), LPE(20:3) ES-(P=0.006), along with menopausal status and BMI provided an 86.0% (95% CI, 77.6%-94.5%) accuracy in predicting higher breast aromatase levels. Combining the effect of two lipids improved the accuracy by 10.4%(P=0.030) compared to the model only using menopausal status and BMI. A model with 5 lipids and menopausal status provided an 88.8%(95% CI, 81.9%-95.8%) accuracy for predicting breast WATi. The model performance improved by 9.2% (P=0.026) compared to the model only using menopausal status and BMI. Conclusions: Our study identified several lipid species that showed significant changes in association with breast WATi and levels of aromatase expression. Further validation of these blood signatures could provide non-invasive assessment of WATi and aromatase levels. The availability of such a diagnostic algorithm could help, in turn, to both identify women at elevated risk for breast cancer and for monitoring the efficacy of interventions aimed at reducing inflammation and aromatase levels.

Citation Format: Xiao Cai, Siqi Wei, Zizhuo Xu, Xi K Zhou, Andrew Peck, Steven Lai, Giorgis Isaac, Hernando Olivos, Nayasha Munjoma, Suraj Dhungana, Rob Plumb, Andrew J Dannenberg, Neil M Iyengar. Plasma lipidomics analysis to identify potential non-invasive biomarkers for breast white adipose inflammation and aromatase expression levels [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 P2-08-05.

Gut microbiota-derived metabolites confer protection against SARS-CoV-2 infection

The gut microbiome is intricately coupled with immune regulation and metabolism, but its role in Coronavirus Disease 2019 (COVID-19) is not fully understood. Severe and fatal COVID-19 is characterized by poor anti-viral immunity and hypercoagulation, particularly in males. Here, we define multiple pathways by which the gut microbiome protects mammalian hosts from SARS-CoV-2 intranasal infection, both locally and systemically, via production of short-chain fatty acids (SCFAs). SCFAs reduced viral burdens in the airways and intestines by downregulating the SARS-CoV-2 entry receptor, angiotensin-converting enzyme 2 (ACE2), and enhancing adaptive immunity via GPR41 and 43 in male animals. We further identify a novel role for the gut microbiome in regulating systemic coagulation response by limiting megakaryocyte proliferation and platelet turnover via the Sh2b3-Mpl axis. Taken together, our findings have unraveled novel functions of SCFAs and fiber-fermenting gut bacteria to dampen viral entry and hypercoagulation and promote adaptive antiviral immunity.

Body Fat Distribution, Cardiometabolic Traits, and Risk of Major Lower-Extremity Arterial Disease in Postmenopausal Women

OBJECTIVE

To assess the relationship between body fat distribution and incident lower-extremity arterial disease (LEAD).

RESEARCH DESIGN AND METHODS

We included 155,925 postmenopausal women with anthropometric measures from the Women's Health Initiative who had no known LEAD at recruitment. A subset of 10,894 participants had body composition data quantified by DXA. Incident cases of symptomatic LEAD were ascertained and adjudicated through medical record review.

RESULTS

We identified 1,152 incident cases of LEAD during a median 18.8 years follow-up. After multivariable adjustment and mutual adjustment, waist and hip circumferences were positively and inversely associated with risk of LEAD, respectively (both P-trend < 0.0001). In a subset (n = 22,561) where various cardiometabolic biomarkers were quantified, a similar positive association of waist circumference with risk of LEAD was eliminated after adjustment for diabetes and HOMA of insulin resistance (P-trend = 0.89), whereas hip circumference remained inversely associated with the risk after adjustment for major cardiometabolic traits (P-trend = 0.0031). In the DXA subset, higher trunk fat (P-trend = 0.0081) and higher leg fat (P-trend < 0.0001) were associated with higher and lower risk of LEAD, respectively. Further adjustment for diabetes, dyslipidemia, and blood pressure diminished the association for trunk fat (P-trend = 0.49), yet the inverse association for leg fat persisted (P-trend = 0.0082).

CONCLUSIONS

Among U.S. postmenopausal women, a positive association of upper-body fat with risk of LEAD appeared to be attributable to traditional risk factors, especially insulin resistance. Lower-body fat was inversely associated with risk of LEAD beyond known risk factors.

Association of a healthy lifestyle index with risk of breast cancer among women with normal body mass index in the UK Biobank

BACKGROUND

A high healthy lifestyle index (HLI), a composite score based on good diet quality, low alcohol consumption, no smoking, moderate to high physical activity, and waist circumference <80cm, has been consistently associated with a reduced risk of breast cancer (BC). Recently, high levels of body fat were found to be associated with an elevated risk of BC in postmenopausal women with a normal body mass index (BMI) (18.5-<25 kg/m2). Whether the HLI is associated with BC risk in women with normal BMI is unknown.

METHODS

We studied 102,572 women aged 40-69 years with a normal BMI at enrollment into the UK Biobank cohort study. The HLI was created by assigning to each component higher scores for healthier behaviors and then summing the scores. The HLI was categorized by tertiles and age- and multivariable-adjusted hazard ratios (HRs) for the association of the HLI with BC risk by menopausal status were estimated using Cox proportional hazards models.

RESULTS

In postmenopausal women, compared to a low HLI, higher scores were associated with a reduced risk of BC (HRHLI-3rd tertile 0.76; 95% CI, 0.64-0.91). Findings were similar for premenopausal women, although they did not reach statistical significance, except when smoking status was excluded from the HLI score (HLIwithout smoking: HR3rd tertile, 0.71; 95% CI, 0.56-0.90).

CONCLUSIONS

In normal BMI postmenopausal women, a high HLI score was associated with a reduced risk of BC.

IMPACT

Following a healthy lifestyle may reduce the risk of BC among normal weight postmenopausal women.

Blood biomarkers reflect the effects of obesity and inflammation on the human breast transcriptome

Obesity is a risk factor for the development of post-menopausal breast cancer. Breast white adipose tissue (WAT) inflammation, which is commonly found in women with excess body fat, is also associated with increased breast cancer risk. Both local and systemic effects are probably important for explaining the link between excess body fat, adipose inflammation and breast cancer. The first goal of this cross-sectional study of 196 women was to carry out transcriptome profiling to define the molecular changes that occur in the breast related to excess body fat and WAT inflammation. A second objective was to determine if commonly measured blood biomarkers of risk and prognosis reflect molecular changes in the breast. Breast WAT inflammation was assessed by immunohistochemistry. Bulk RNA-sequencing was carried out to assess gene expression in non-tumorous breast. Obesity and WAT inflammation were associated with a large number of differentially expressed genes and changes in multiple pathways linked to the development and progression of breast cancer. Altered pathways included inflammatory response, complement, KRAS signaling, tumor necrosis factor α signaling via NFkB, interleukin (IL)6-JAK-STAT3 signaling, epithelial mesenchymal transition, angiogenesis, interferon γ response and transforming growth factor (TGF)-β signaling. Increased expression of several drug targets such as aromatase, TGF-β1, IDO-1 and PD-1 were observed. Levels of various blood biomarkers including high sensitivity C-reactive protein, IL6, leptin, adiponectin, triglycerides, high-density lipoprotein cholesterol and insulin were altered and correlated with molecular changes in the breast. Collectively, this study helps to explain both the link between obesity and breast cancer and the utility of blood biomarkers for determining risk and prognosis.

Dietary fructose improves intestinal cell survival and nutrient absorption

Fructose consumption is linked to the rising incidence of obesity and cancer, which are two of the leading causes of morbidity and mortality globally1,2. Dietary fructose metabolism begins at the epithelium of the small intestine, where fructose is transported by glucose transporter type 5 (GLUT5; encoded by SLC2A5) and phosphorylated by ketohexokinase to form fructose 1-phosphate, which accumulates to high levels in the cell3,4. Although this pathway has been implicated in obesity and tumour promotion, the exact mechanism that drives these pathologies in the intestine remains unclear. Here we show that dietary fructose improves the survival of intestinal cells and increases intestinal villus length in several mouse models. The increase in villus length expands the surface area of the gut and increases nutrient absorption and adiposity in mice that are fed a high-fat diet. In hypoxic intestinal cells, fructose 1-phosphate inhibits the M2 isoform of pyruvate kinase to promote cell survival5-7. Genetic ablation of ketohexokinase or stimulation of pyruvate kinase prevents villus elongation and abolishes the nutrient absorption and tumour growth that are induced by feeding mice with high-fructose corn syrup. The ability of fructose to promote cell survival through an allosteric metabolite thus provides additional insights into the excess adiposity generated by a Western diet, and a compelling explanation for the promotion of tumour growth by high-fructose corn syrup.

GLUT5 is a determinant of dietary fructose-mediated exacerbation of experimental colitis

The Western diet has been suggested to contribute to the rising incidence of inflammatory bowel diseases. This has led to the hypothesis that fructose, a component of the Western diet, could play a role in the pathogenesis of inflammatory bowel diseases. A high-fructose diet is known to exacerbate experimental colitis. This study tested whether the expression of GLUT5, the fructose transporter, is a determinant of the severity of experimental colitis during elevated fructose consumption and whether ileal inflammation is associated with altered GLUT5 expression in Crohn's disease. Studies in genetically engineered mice showed that in comparison to Glut5^+/+ mice, feeding a 15 kcal% fructose diet to Glut5^-/- mice led to worse dextran sodium sulfate (DSS)-induced colitis. This effect was associated with elevated levels of colonic fructose and a shift in the fecal microbiota in Glut5^-/- mice. Importantly, treatment with broad-spectrum antibiotics protected against the worsening of colitis mediated by dietary fructose in Glut5^-/- mice. Gene expression analysis revealed that GLUT5 levels are reduced in the intestines of patients with ileal Crohn's disease. Moreover, levels of GLUT5 negatively correlated with expression of proinflammatory mediators in these samples. Collectively, these results demonstrate that dietary constituent (fructose)-host gene (GLUT5) interactions can shape the colonic microbiota, thereby impacting the severity of colitis.NEW & NOTEWORTHY This study provides the first evidence that reduced levels of GLUT5, the fructose transporter, worsen experimental colitis upon fructose feeding, an effect mediated by changes in the gut microbiota. Moreover, GLUT5 expression is reduced in Crohn's ileitis. Overall, these findings demonstrate the importance of interactions between dietary fructose and host GLUT5 as determinants of both the composition of colonic microbiota and severity of experimental colitis.

Anti-tumor effects of an ID antagonist with no observed acquired resistance

ID proteins are helix-loop-helix (HLH) transcriptional regulators frequently overexpressed in cancer. ID proteins inhibit basic-HLH transcription factors often blocking differentiation and sustaining proliferation. A small-molecule, AGX51, targets ID proteins for degradation and impairs ocular neovascularization in mouse models. Here we show that AGX51 treatment of cancer cell lines impairs cell growth and viability that results from an increase in reactive oxygen species (ROS) production upon ID degradation. In mouse models, AGX51 treatment suppresses breast cancer colonization in the lung, regresses the growth of paclitaxel-resistant breast tumors when combined with paclitaxel and reduces tumor burden in sporadic colorectal neoplasia. Furthermore, in cells and mice, we fail to observe acquired resistance to AGX51 likely the result of the inability to mutate the binding pocket without loss of ID function and efficient degradation of the ID proteins. Thus, AGX51 is a first-in-class compound that antagonizes ID proteins, shows strong anti-tumor effects and may be further developed for the management of multiple cancers.

Five-Year Outcomes of Endoscopic Sleeve Gastroplasty for the Treatment of Obesity

BACKGROUND AND AIMS

The growing burden of obesity as a chronic disease necessitates a multifaceted approach to management. There has been an increase in the number of available endoscopic therapies for weight management with endoscopic sleeve gastroplasty (ESG) proving to be one of the best options. The long-term efficacy of ESG for management of obesity is not known. This study sought to assess the long-term safety and efficacy of ESG for treatment of obesity.

METHODS

This was a prospective cohort study. Participants underwent ESG in a single academic center, and were prospectively enrolled. All procedures were performed by the same therapeutic endoscopist. Patients with a body mass index of >30 kg/m2 (or >27 with comorbidities), who underwent ESG from August 2013 to August 2019 for treatment of obesity were enrolled. Patients were followed for up to 5 years after their procedure. The primary outcome was weight loss at 5 years after the procedure (% total body weight loss, TBWL) RESULTS: 216 patients (68% female) with a mean age of 46±13 years, and mean BMI of 39±6 kg/m² underwent ESG. Out of 216 patients, 203, 96, and 68 patients were eligible for a 1-, 3-, and 5-year follow up, with complete follow-up rates of 70%, 71%, and 82%, respectively. At 5 years, mean TBWL was 15.9% (95% CI, 11.7-20.5, p < .001) and 90 and 61% of patients maintained 5 and 10% TBWL, respectively. There was an overall rate of 1.3% moderate adverse events (AEs), without any severe or fatal AEs.

CONCLUSIONS

Our results suggest that ESG is safe and effective for treatment of obesity, with durable long-term results for at least up to 5 years after the procedure. This procedure should be considered as a reliable option for treatment of obesity.

Cancer Risk in Normal Weight Individuals with Metabolic Obesity: A Narrative Review

Obesity represents one of the most significant public health challenges worldwide. Current clinical practice relies on body mass index (BMI) to define the obesity status of an individual, even though the index has long been recognized for its limitations as a measure of body fat. In normal BMI individuals, increased central adiposity has been associated with worse health outcomes, including increased risks of cardiovascular disease and metabolic disorders. The condition leading to these outcomes has been described as metabolic obesity in the normal weight (MONW). More recent evidence suggests that MONW is associated with increased risk of several obesity-related malignancies, including postmenopausal breast, endometrial, colorectal, and liver cancers. In MONW patients, the false reassurance of a normal range BMI can lead to lost opportunities for implementing preventive interventions that may benefit a substantial number of people. A growing body of literature has documented the increased risk profile of MONW individuals and demonstrated practical uses for body composition and biochemical analyses to identify this at-risk population. In this review, we survey the current literature on MONW and cancer, summarize pathophysiology and oncogenic mechanisms, highlight potential strategies for diagnosis and treatment, and suggest directions for future research.

Improvement in insulin resistance and estimated hepatic steatosis and fibrosis after endoscopic sleeve gastroplasty

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the United States and is closely associated with obesity and insulin resistance (IR). Weight loss is the best treatment for NAFLD. Endoscopic sleeve gastroplasty (ESG) is a promising endoscopic procedure for treatment of obesity. Our aim is to evaluate the change in IR and estimated hepatic steatosis and fibrosis after ESG.

METHODS

One hundred eighteen patients with obesity and NAFLD underwent ESG and were followed for 2 years. Weight loss was evaluated as % total body weight loss. IR was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR). The previously validated hepatic steatosis index and NAFLD fibrosis score were used to estimate hepatic steatosis and risk of fibrosis.

RESULTS

Patients' mean body mass index was 40 ± 7 kg/m² at baseline. Eighty-four percent of patients completed 2 years of follow-up. At 2 years, the mean total body weight loss was 15.5% (95% confidence interval, 13.3%-17.8%). Patients' HOMA-IR improved significantly from 6.7 ± 11 to 3.0 ± 1.6 after only 1 week from ESG (P = .019) with continued improvement up to 2 years (P = .03). Patients' hepatic steatosis index score improved significantly, decreasing by 4 points per year (P for trend, <.001). Patients' NAFLD fibrosis score improved significantly, decreasing by 0.3 point per year (P for trend, .034). Twenty-four patients (20%) improved their risk of hepatic fibrosis from F3-F4 or indeterminate to F0-F2, whereas only 1 patient (1%) experienced an increase in the estimated risk of fibrosis (P = .02).

CONCLUSIONS

Our results suggest a significant and sustained improvement in estimated hepatic steatosis and fibrosis after ESG in patients with NAFLD. Importantly, we showed an early and weight-independent improvement in insulin resistance, which lasted for 2 years after the procedure.

The association of body fat composition with risk of breast, endometrial, ovarian and colorectal cancers among normal weight participants in the UK Biobank

BACKGROUND

The association between body fat composition and risk of cancer in normal weight individuals (body mass index (BMI) 18.5-24.9 kg/m2) is unclear.

METHODS

We examined the association of measures of adiposity with risk of incident cancers of the breast (postmenopausal), endometrium, ovary and colon/rectum among 149,928 normal weight individuals (40-70 years) who were enrolled in the UK Biobank cohort between 2006 and 2010.

RESULTS

All of the body fat measures were positively associated with invasive postmenopausal breast cancer risk (hazard ratios (HR) for the uppermost quintile (Q5) versus the lowest quintile (Q1) ranged from 1.32 (95% CI: 1.09-1.60) for waist circumference (WC) to 1.56 (1.28-1.90) for BMI). Trunk fat mass index (HRQ5 vs Q1: 1.72, 95% CI: 1.02-2.89) and WC (HRQ5 vs Q1: 1.65, 95% CI: 1.01-2.70)) were positively associated with risk of endometrial cancer. Among males, trunk fat:trunk fat free mass ratio, trunk fat:leg fat mass ratio and (HRQ5 vs Q1: 1.63, 95% CI: 1.02-2.60; 1.92, 1.20-3.07 and 1.68, 1.05-2.66, respectively) were positively associated with colon cancer risk. None of the body fat measures was associated with risk of ovarian cancer or colorectal cancer in women.

CONCLUSION

The findings of this study suggest that the current normal weight category based on BMI includes individuals who are at increased risk of some obesity-related cancers.

Dietary interventions to prevent high-fructose diet-associated worsening of colitis and colitis-associated tumorigenesis in mice

Diet is believed to be an important factor in the pathogenesis of inflammatory bowel disease. High consumption of dietary fructose has been shown to exacerbate experimental colitis, an effect mediated through the gut microbiota. This study evaluated whether dietary alterations could attenuate the detrimental effects of a high-fructose diet (HFrD) in experimental colitis. First, we determined whether the procolitic effects of a HFrD could be reversed by switching mice from a HFrD to a control diet. This diet change completely prevented HFrD-induced worsening of acute colitis, in association with a rapid normalization of the microbiota. Second, we tested the effects of dietary fiber, which demonstrated that psyllium was the most effective type of fiber for protecting against HFrD-induced worsening of acute colitis, compared with pectin, inulin, or cellulose. In fact, supplemental psyllium nearly completely prevented the detrimental effects of the HFrD, an effect associated with a shift in the gut microbiota. We next determined whether the protective effects of these interventions could be extended to chronic colitis and colitis-associated tumorigenesis. Using the azoxymethane/dextran sodium sulfate model, we first demonstrated that HFrD feeding exacerbated chronic colitis and increased colitis-associated tumorigenesis. Using the same dietary changes tested in the acute colitis setting, we also showed that mice were protected from HFrD-mediated enhanced chronic colitis and tumorigenesis, upon either diet switching or psyllium supplementation. Taken together, these findings suggest that high consumption of fructose may enhance colon tumorigenesis associated with long-standing colitis, an effect that could be reduced by dietary alterations.

Creatine-mediated crosstalk between adipocytes and cancer cells regulates obesity-driven breast cancer

Obesity is a major risk factor for adverse outcomes in breast cancer; however, the underlying molecular mechanisms have not been elucidated. To investigate the role of crosstalk between mammary adipocytes and neoplastic cells in the tumor microenvironment (TME), we performed transcriptomic analysis of cancer cells and adjacent adipose tissue in a murine model of obesity-accelerated breast cancer and identified glycine amidinotransferase (Gatm) in adipocytes and Acsbg1 in cancer cells as required for obesity-driven tumor progression. Gatm is the rate-limiting enzyme in creatine biosynthesis, and deletion in adipocytes attenuated obesity-driven tumor growth. Similarly, genetic inhibition of creatine import into cancer cells reduced tumor growth in obesity. In parallel, breast cancer cells in obese animals upregulated the fatty acyl-CoA synthetase Acsbg1 to promote creatine-dependent tumor progression. These findings reveal key nodes in the crosstalk between adipocytes and cancer cells in the TME necessary for obesity-driven breast cancer progression.

Effects of Adiposity and Exercise on Breast Tissue and Systemic Metabo-Inflammatory Factors in Women at High Risk or Diagnosed with Breast Cancer

Excess body fat and sedentary behavior are associated with increased breast cancer risk and mortality, including in normal weight women. To investigate underlying mechanisms, we examined whether adiposity and exercise impact the breast microenvironment (e.g., inflammation and aromatase expression) and circulating metabo-inflammatory factors. In a cross-sectional cohort study, breast white adipose tissue (WAT) and blood were collected from 100 women undergoing mastectomy for breast cancer risk reduction or treatment. Self-reported exercise behavior, body composition measured by dual-energy x-ray absorptiometry (DXA), and waist:hip ratio were obtained prior to surgery. Breast WAT inflammation (B-WATi) was assessed by IHC and aromatase expression was assessed by quantitative PCR. Metabolic and inflammatory blood biomarkers that are predictive of breast cancer risk and progression were measured. B-WATi was present in 56 of 100 patients and was associated with older age, elevated BMI, postmenopausal status, decreased exercise, hypertension and dyslipidemia (Ps < 0.001). Total body fat and trunk fat correlated with B-WATi and breast aromatase levels (Ps < 0.001). Circulating C-reactive protein, IL6, insulin, and leptin positively correlated with body fat and breast aromatase levels, while negative correlations were observed for adiponectin and sex hormone binding globulin (P < 0.001). Inverse relationships were observed with exercise (Ps < 0.05). In a subgroup of 39 women with normal BMI, body fat levels positively correlated with B-WATi and aromatase expression (Ps < 0.05). In conclusion, elevated body fat levels and decreased exercise are associated with protumorigenic micro- and host environments in normal, overweight, and obese individuals. These findings support the development of BMI-agnostic lifestyle interventions that target adiposity. PREVENTION RELEVANCE: We report that individuals with high body fat and low exercise levels have breast inflammation, higher breast aromatase expression, and levels of circulating metabo-inflammatory factors that have been associated with increased breast cancer risk. These findings support interventions to lower adiposity, even among normal weight individuals, to prevent tumor growth.

Effects of obesity on breast aromatase expression and systemic metabo-inflammation in women with BRCA1 or BRCA2 mutations

Obesity is associated with an increased risk of breast cancer in post-menopausal women and decreased risk in pre-menopausal women. Conversely, in BRCA1/2 mutation carriers, pre-menopausal obesity is associated with early-onset breast cancer. Here we show that obese, pre-menopausal BRCA1/2 mutation carriers have increased levels of aromatase and inflammation in the breast, as occurs in post-menopausal women. In a prospective cohort study of 141 women with germline BRCA1 (n = 74) or BRCA2 (n = 67) mutations, leptin, and aromatase expression were higher in the breast tissue of obese versus lean individuals (P < 0.05). Obesity was associated with breast white adipose tissue inflammation, which correlated with breast aromatase levels (P < 0.01). Circulating C-reactive protein, interleukin-6, and leptin positively correlated with body mass index and breast aromatase levels, whereas negative correlations were observed for adiponectin and sex hormone-binding globulin (P < 0.05). These findings could help explain the increased risk of early-onset breast cancer in obese BRCA1/2 mutation carriers.

The association of prediagnostic circulating levels of cardiometabolic markers, testosterone and sex hormone-binding globulin with risk of breast cancer among normal weight postmenopausal women in the UK Biobank

Emerging evidence suggests that normal weight postmenopausal women with a relative excess of body fat are at increased breast cancer risk. However, little is known about the associations between obesity-related blood markers and risk of breast cancer among these individuals. In this prospective study comprising 58 629 normal weight postmenopausal women (body mass index between 18.5 kg/m² and 24.9 kg/m² ) who were enrolled in the UK Biobank cohort between 2006 and 2010, we examined the associations of glycated hemoglobin, triglycerides, high-density lipoprotein cholesterol, C-reactive protein (CRP), testosterone and sex hormone-binding globulin (SHBG) with risk of breast cancer. A total of 1268 postmenopausal breast cancer cases were ascertained during a median follow-up period of 7 years. Women with CRP, total testosterone and free testosterone (FT) levels in the highest quintile had increased risk of breast cancer compared to those in the lowest quintile (HR_{Q5 vs Q1} : 1.35, 95% confidence interval [CI]: 1.12-1.63, HR _{Q5 vs Q1} : 1.47, 95% CI: 1.20-1.80 and HR _{Q5 vs Q1} : 1.53, 95% CI: 1.23-1.90, respectively), whereas those with SHBG in the highest quintile had reduced risk (HR _{Q5 vs Q1} : 0.70, 95% CI: 0.56-0.88). These associations were attenuated but persisted after additional adjustment for BMI, fat mass index (whole body fat mass [kg]/height [m² ]) or waist circumference and after mutual adjustment for testosterone, CRP and/or SHBG. Our study suggests that the risk of postmenopausal breast cancer among normal weight women is increased in association with relatively high levels of CRP and testosterone and with relatively low levels of SHBG.

Performing Colonoscopic-Guided Pinch Biopsies in Mice and Evaluating Subsequent Tissue Changes

Understanding the tissue and cellular changes that occur in the acute injury response as well as during the wound healing process is of paramount importance when studying diseases of the gastrointestinal (GI) tract. The murine colonic pinch biopsy model is a useful tool to define these processes. Additionally, the interplay between gut luminal content (e.g., microbes) and the colon can be studied. However, wound induction and the ability to track wound closure over time in a reliable manner can be challenging. Moreover, tissue preparation and orientation must be carried out in a standardized way to optimally interrogate histologic and molecular changes. Here, we present a detailed method describing biopsy-induced injury and the monitoring of wound closure through repeat colonoscopies. An approach is described that ensures consistent and reproducible measurements of wound size, the ability to collect the wound bed for molecular analyses as well as visualize the wound bed upon sectioning of tissues. The ability to successfully carry out these techniques allows for studies of the acute injury response, wound healing and luminal-host interactions within the colon.

Exogenous and Endogenous Sources of Serine Contribute to Colon Cancer Metabolism, Growth, and Resistance to 5-Fluorouracil

Serine is a nonessential amino acid generated by the sequential actions of phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase (PSAT1), and phosphoserine phosphatase (PSPH). Increased serine biosynthesis occurs in several cancers and supports tumor growth. In addition, cancer cells can harness exogenous serine to enhance their metabolism and proliferation. Here we tested the relative contributions of exogenous and endogenous sources of serine on the biology of colorectal cancer. In murine tumors, Apc status was identified as a determinant of the expression of genes controlling serine synthesis. In patient samples, PSAT1 was overexpressed in both colorectal adenomas and adenocarcinomas. Combining genetic deletion of PSAT1 with exogenous serine deprivation maximally suppressed the proliferation of colorectal cancer cells and induced profound metabolic defects including diminished nucleotide production. Inhibition of serine synthesis enhanced the transcriptional changes following exogenous serine removal as well as alterations associated with DNA damage. Both loss of PSAT1 and removal of serine from the diet were necessary to suppress colorectal cancer xenograft growth and enhance the antitumor activity of 5-fluorouracil (5-FU). Restricting endogenous and exogenous serine in vitro augmented 5-FU-induced cell death, DNA damage, and metabolic perturbations, likely accounting for the observed antitumor effect. Collectively, our results suggest that both endogenous and exogenous sources of serine contribute to colorectal cancer growth and resistance to 5-FU. SIGNIFICANCE: These findings provide insights into the metabolic requirements of colorectal cancer and reveal a novel approach for its treatment. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/9/2275/F1.large.jpg.

Association between regional body fat and cardiovascular disease risk among postmenopausal women with normal body mass index

AIMS

Central adiposity is associated with increased cardiovascular disease (CVD) risk, even among people with normal body mass index (BMI). We tested the hypothesis that regional body fat deposits (trunk or leg fat) are associated with altered risk of CVD among postmenopausal women with normal BMI.

METHODS AND RESULTS

We included 2683 postmenopausal women with normal BMI (18.5 to <25 kg/m2) who participated in the Women's Health Initiative and had no known CVD at baseline. Body composition was determined by dual energy X-ray absorptiometry. Incident CVD events including coronary heart disease and stroke were ascertained through February 2017. During a median 17.9 years of follow-up, 291 incident CVD cases occurred. After adjustment for demographic, lifestyle, and clinical risk factors, neither whole-body fat mass nor fat percentage was associated with CVD risk. Higher percent trunk fat was associated with increased risk of CVD [highest vs. lowest quartile hazard ratio (HR) = 1.91, 95% confidence interval (CI) 1.33-2.74; P-trend <0.001], whereas higher percent leg fat was associated with decreased risk of CVD (highest vs. lowest quartile HR = 0.62, 95% CI 0.43-0.89; P-trend = 0.008). The association for trunk fat was attenuated yet remained significant after further adjustment for waist circumference or waist-to-hip ratio. Higher percent trunk fat combined with lower percent leg fat was associated with particularly high risk of CVD (HR comparing extreme groups = 3.33, 95% CI 1.46-7.62).

CONCLUSION

Among postmenopausal women with normal BMI, both elevated trunk fat and reduced leg fat are associated with increased risk of CVD.

Induction of colitis-associated neoplasia in mice using azoxymethane and dextran sodium sulfate

Long-standing inflammatory bowel diseases (IBD) increase the risk for the development of colorectal cancer (CRC). This increase is due in large part to chronic intestinal inflammation which exposes the epithelium to pro-carcinogenic factors. Moreover, enhanced mucosal proliferation associated with repetitive wound healing events following an inflammatory episode, further enhance this pro-tumorigenic environment. Although multiple factors involved in IBD pathogenesis and its associated neoplasia have been identified, more work is needed to develop and improve therapies to ameliorate disease and thus reduce CRC risk. Murine models have served as useful tools to identify factors involved in the pathogenesis of colitis-associated neoplasia and test therapies. These include both chemically-induced and genetic engineering approaches, resulting in chronic inflammation and tumor development. Here, we present a step-by-step method of inducing inflammation-associated colon neoplasia by combining administration of azoxymethane and dextran sodium sulfate in mice. A detailed description of this methodology will facilitate its use in the scientific community with the goals of further elucidating the mechanisms underlying colitis-associated tumorigenesis and developing risk reducing interventions.

Docked severe acute respiratory syndrome coronavirus 2 proteins within the cutaneous and subcutaneous microvasculature and their role in the pathogenesis of severe coronavirus disease 2019

The purpose of this study was to examine the deltoid skin biopsy in twenty-three patients with coronavirus disease 2019 (COVID-19), most severely ill, for vascular complement deposition and correlate this with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA and protein localization and ACE2 expression. Deltoid skin microvascular complement screening has been applied to patients with various systemic complement-mediated microvascular syndromes, best exemplified by atypical hemolytic uremic syndrome. In 21 of 23 cases, substantial microvascular deposition of complement components was identified. The two patients without significant complement deposition included one patient with moderate disease and a severely ill patient who although on a ventilator for a day was discharged after 3 days. The dominant microvascular complement immunoreactant identified was the terminal membranolytic attack complex C5b-9. Microvascular complement deposition strongly colocalized in situ with the SARS-CoV-2 viral proteins including spike glycoproteins in the endothelial cells as well as the viral receptor ACE2 in lesional and nonlesional skin; viral RNA was not evident. Microvascular SARS-CoV-2 viral protein, complement, and ACE2 expression was most conspicuous in the subcutaneous fat. Although the samples from severely ill patients with COVID-19 were from grossly normal skin, light microscopically focal microvascular abnormalities were evident that included endothelial cell denudement, basement membrane zone reduplication, and small thrombi. It is concluded that complement activation is common in grossly normal skin, especially in the subcutaneous fat which may provide a link between severe disease and obesity, in people with severe COVID-19, and the strong colocalization with the ACE2 receptor and viral capsid proteins without viral RNA suggests that circulating viral proteins (ie, pseudovirions) may dock onto the endothelial of these microvessels and induce complement activation.

Dietary Fructose Alters the Composition, Localization, and Metabolism of Gut Microbiota in Association With Worsening Colitis

BACKGROUND & AIMS

The incidence of inflammatory bowel diseases has increased over the last half century, suggesting a role for dietary factors. Fructose consumption has increased in recent years. Recently, a high fructose diet (HFrD) was shown to enhance dextran sodium sulfate (DSS)-induced colitis in mice. The primary objectives of the current study were to elucidate the mechanism(s) underlying the pro-colitic effects of dietary fructose and to determine whether this effect occurs in both microbially driven and genetic models of colitis.

METHODS

Antibiotics and germ-free mice were used to determine the relevance of microbes for HFrD-induced worsening of colitis. Mucus thickness and quality were determined by histologic analyses. 16S rRNA profiling, in situ hybridization, metatranscriptomic analyses, and fecal metabolomics were used to determine microbial composition, spatial distribution, and metabolism. The significance of HFrD on pathogen and genetic-driven models of colitis was determined by using Citrobacter rodentium infection and Il10^-/- mice, respectively.

RESULTS

Reducing or eliminating bacteria attenuated HFrD-mediated worsening of DSS-induced colitis. HFrD feeding enhanced access of gut luminal microbes to the colonic mucosa by reducing thickness and altering the quality of colonic mucus. Feeding a HFrD also altered gut microbial populations and metabolism including reduced protective commensal and bile salt hydrolase-expressing microbes and increased luminal conjugated bile acids. Administration of conjugated bile acids to mice worsened DSS-induced colitis. The HFrD also worsened colitis in Il10^-/- mice and mice infected with C rodentium.

CONCLUSIONS

Excess dietary fructose consumption has a pro-colitic effect that can be explained by changes in the composition, distribution, and metabolic function of resident enteric microbiota.

Obesity is Associated with Worse Outcomes in COVID-19: Analysis of Early Data from New York City

OBJECTIVE

The 2019 novel coronavirus disease (COVID-19) has triggered a rapidly expanding global pandemic in which patients exhibit a wide spectrum of disease severity. Given the high prevalence of obesity in the United States, we hypothesized that the presence of obesity may play a role in the clinical course of patients with COVID-19.

METHODS

This is a retrospective review of adult patients admitted with confirmed severe acute respiratory syndrome coronavirus 2. Demographics, clinical characteristics, laboratory data, and clinical outcomes were abstracted. BMI (kilograms per meter squared) was analyzed with regard to a composite outcome of intensive care unit (ICU) admission or death and intubation rate.

RESULTS

About 770 patients were included (61% male, mean age 63.5 years). Patients with obesity were more likely to present with fever, cough, and shortness of breath. Obesity was also associated with a significantly higher rate of ICU admission or death (RR = 1.58, P = 0.002) even after adjusting for age, race, and troponin level.

CONCLUSIONS

Patients with obesity had an increased risk for critical illness leading to ICU admission or death compared with normal weight individuals. This study confirms that obesity is a major risk factor for COVID-19 disease severity, significantly impacting disease presentation and critical care requirements.

Abstract 3745: Exogenous and endogenous sources of serine contribute to colon cancer metabolism and growth

Serine is a non-essential amino acid that is generated by the sequential actions of phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase (PSAT1) and phosphoserine phosphatase (PSPH). Increased serine biosynthesis occurs in several cancers and supports tumor growth. In addition to serine synthesis, exogenous serine is taken up by cells and can also fuel tumor growth. Interestingly, colon cancer cells increase expression of serine biosynthesis enzymes in the absence of exogenous serine, suggesting a compensatory adaptive response to reduced availability of serine. This study explored the relative contributions of exogenous and synthesized serine to colon cancer cell growth, metabolism and response to anti-cancer therapy. We found that PSAT1 expression was markedly increased in human colonic adenomas and colorectal cancer (CRC) compared to normal adjacent tissue. Additionally, high levels of PSAT1 in CRC were associated with reduced patient survival. Deletion of PSAT1 only modestly reduced colon cancer cell proliferation in vitro. Removal of serine from the medium strongly suppressed cell proliferation whereas the combination of removing exogenous serine and deleting PSAT1 caused even greater inhibition of cell proliferation. Metabolite profiling revealed altered nucleotide levels upon exogenous serine depletion, an effect that was enhanced when PSAT1 was deleted. Global gene expression profiling showed approximately 3,000 differentially expressed genes when only exogenous serine was removed, with an additional ~800 changes in PSAT1 knockout (KO) cells grown in serine deficient medium. A marked DNA damage response was induced selectively in PSAT1KO cells in serine deficient medium, which was prevented by the addition of formate. Xenografts derived from PSAT1 sufficient and PSAT1KO cells showed that neither PSAT1 deletion alone nor removal of dietary serine alone affected tumor growth, but the combination resulted in profound growth suppression. Additionally, treatment with 5-fluorouracil (5-FU) in the xenograft model induced a strong regression of established tumors derived from mice carrying PSAT1KO cells fed a serine deficient diet. Complementary in vitro studies showed enhanced sensitivity of PSAT1KO cells grown in serine deficient medium to 5-FU induced death, which was preceded by specific metabolite changes including markedly reduced levels of TMP and TTP. Taken together, our results suggest that both exogenous and endogenous sources of serine are important contributors to colon cancer cell proliferation and metabolism. Limiting exogenously available and synthesized serine may be an effective strategy to limit colon cancer growth and enhance the efficacy of treatment.

Citation Format: David C. Montrose, Miguel Foronda, Suchandrima Saha, Erin M. McNally, Xi Kathy Zhou, Jan Krumsiek, Akanksha Verma, Olivier Elemento, Rhonda K. Yantiss, Qiuying Chen, Steven S. Gross, Lorenzo Galluzzi, Lukas E. Dow, Andrew J. Dannenberg. Exogenous and endogenous sources of serine contribute to colon cancer metabolism and growth [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3745.

Abstract 3966: The procancer effects of obesity can be reversed by moderate weight loss or an anti-inflammatory drug in a mouse model of colon cancer

Purpose: Obesity is associated with an increased risk of colon cancer. Our current study examines whether moderate weight loss or treatment with the non-steroidal anti-inflammatory drug sulindac suppresses the tumor-promoting effects of obesity in a mouse model of colon cancer.

Methods: Male FVB mice were treated with azoxymethane (10 mg/kg i.p.) for 5 weeks, then randomized to a control (10% kcal from fat) or diet-induced obesity (DIO, 60% kcal from fat) diet. After 15 weeks, there was an interim sacrifice of 5 mice/group. The DIO mice were then further randomized to remain on DIO or switch to control diet to induce weight loss and become formerly obese mice (FOB), and within each diet group (control, DIO, and FOB), half the mice were randomized to start sulindac treatment (140 ppm in the diet). Eight weeks later, all mice were euthanized.

Results: The DIO mice, compared to controls, had significantly greater body weight and body fat (P&lt;0.05), while FOB mice had intermediate levels of adiposity. Sulindac did not affect adiposity in any diet group. At the interim timepoint, DIO mice had 10-fold greater tumor multiplicity relative to control mice (P=0.07). At study endpoint, DIO mice had greater tumor multiplicity compared to both control (P&lt;0.05) and FOB (P&lt;0.01) mice, which did not significantly differ from each other. Sulindac reduced tumor multiplicity in both control (P&lt;0.05) and DIO (P&lt;0.0001) mice, but not FOB mice. Serum levels of several inflammation-related proteins, including interleukin 6, chemokine (C-X-C motif) ligand 1, monocyte chemoattractant protein 1, and vascular endothelial growth factor, were elevated in DIO mice versus control (P&lt;0.05) and DIO+sulindac (P&lt;0.01) mice, but not in comparison to FOB mice. Gene expression in paired colon tumor and mesenteric adipose tissue samples was assessed by microarray. Ingenuity pathway analysis (IPA) of the significant (P&lt;0.05) differentially expressed tumor genes indicated that both weight loss and sulindac reduced signaling related to matrix metalloproteinases (MMPs) and inflammation. In the visceral adipose tissue, IPA demonstrated that weight loss reduced signaling related to B cell receptors and glucose/fatty acid metabolism while sulindac decreased MMP, prostaglandin, and PPAR signaling. Additional analyses to explore the potential role of cross-talk between these two tissues are being performed, and key findings will be validated in the tissues at the protein level and via mechanistic cell culture experiments.

Conclusions: Both moderate weight loss and sulindac treatment completely reverse the effects of chronic obesity on colon tumorigenesis, the latter independent of any change in adiposity. Our findings suggest that an investigation regarding the effects of NSAID treatment on colon cancer risk and/or progression in obese patients is warranted, particularly for those unable to achieve moderate weight loss.

Citation Format: Laura W. Bowers, Arunima Punjala, Alison Q. Jeffries, Stephanie A. Montgomery, Andrew J. Dannenberg, Stephen D. Hursting. The procancer effects of obesity can be reversed by moderate weight loss or an anti-inflammatory drug in a mouse model of colon cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3966.

Supplemental estrogen and caloric restriction reduce obesity-induced periprostatic white adipose inflammation in mice

Obesity is associated with an increased incidence of high-grade prostate cancer (PC) and worse prognosis for PC patients. Recently, we showed in men that obesity-related periprostatic white adipose tissue (WAT) inflammation, characterized by macrophages surrounding dead or dying adipocytes forming crown-like structures, was associated with high-grade PC. Possibly, interventions that suppress periprostatic WAT inflammation will improve outcomes for men with PC. Here, we tested the hypothesis that supplemental 17β-estradiol (E2) could decrease periprostatic WAT inflammation in obese male mice. Mice were fed a high-fat diet to induce periprostatic WAT inflammation before being treated with supplemental E2. E2 supplementation suppressed caloric intake, induced weight loss, decreased periprostatic WAT inflammation and downregulated the expression of genes linked to inflammation including Cd68, Mcp1 and Tnf. Similar to the effects of E2 supplementation, treatment with diethylstilbestrol, a synthetic estrogen, also suppressed caloric intake and reduced periprostatic WAT inflammation. To determine whether the observed effects of supplemental estrogen could be reproduced by caloric restriction (CR) alone, obese mice were put on a 30% CR diet. Like estrogen treatment, CR was effective in reducing body weight, periprostatic WAT inflammation and the expression of pro-inflammatory genes. Transcriptomic analyses of periprostatic fat showed that obesity was associated with enrichment in inflammatory response pathways, which were normalized by both supplemental E2 and CR. Taken together, these findings strengthen the rationale for future efforts to determine whether either CR or supplemental estrogen will decrease periprostatic WAT inflammation and thereby improve outcomes for men with PC.