Nutritional Mechanisms of Cancer Cachexia.

Cancer cachexia is a complex systemic wasting syndrome. Nutritional mechanisms that span energy intake, nutrient metabolism, body composition, and energy balance may be impacted by, and may contribute to, the development of cachexia. To date, clinical management of cachexia remains elusive. Leaning on discoveries and novel methodologies from other fields of research may bolster new breakthroughs that improve nutritional management and clinical outcomes. Characteristics that compare and contrast cachexia and obesity may reveal opportunities for cachexia research to adopt methodology from the well-established field of obesity research. This review outlines the known nutritional mechanisms and gaps in the knowledge surrounding cancer cachexia. In parallel, we present how obesity may be a different side of the same coin and how obesity research has tackled similar research questions. We present insights into how cachexia research may utilize nutritional methodology to expand our understanding of cachexia to improve definitions and clinical care in future directions for the field.

Dietary quality and chemotherapy-induced peripheral neuropathy in colon cancer.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common and dose-limiting chemotoxicity caused by oxaliplatin. This study investigated the relationship between dietary quality and the development of moderate and/or severe CIPN in colon cancer survivors using data from the Focus on Reducing Dose-Limiting Toxicities in Colon Cancer with Resistance Exercise trial (ClinicalTrials.gov identifier NCT03291951). METHODS: Diet quality was collected using a 127-item food-frequency questionnaire and was scored using the Alternative Healthy Eating Index-2010 (AHEI-2010). CIPN was assessed with the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events at each chemotherapy cycle. The association of dietary quality with time to the first moderate-to-severe (moderate-severe) or severe event of CIPN was estimated using Cox proportional hazards models. Only participants who received oxaliplatin were included in this analysis (n = 132). RESULTS: Seventy-four participants (56.1%) reported moderate-severe CIPN. Higher dietary quality was associated with a significantly decreased risk of moderate-severe CIPN (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.93-0.99) and severe CIPN (HR, 0.91; 95% CI, 0.85-0.98). Consumption of red and processed meat (HR, 1.78; 95% CI, 1.07-2.83) and sugar-sweetened beverages (HR, 1.33; 95% CI, 1.10-1.59) was associated with an increased risk of moderate-severe CIPN. Consumption of sugar-sweetened beverages also was associated with an increased risk of severe CIPN (HR, 1.57; 95% CI, 1.14-2.18), whereas vegetable consumption was associated with a reduced risk of severe CIPN (HR, 0.29; 95% CI, 0.09-0.73). CONCLUSIONS: Among patients with colon cancer who received oxaliplatin-based chemotherapy, higher baseline dietary quality was associated with a reduced risk of moderate-severe CIPN.

Genetic and Functional Modifications Associated with Ovarian Cancer Cell Aggregation and Limited Culture Conditions.

The aggregation of cancer cells provides a survival signal for disseminating cancer cells; however, the underlying molecular mechanisms have yet to be elucidated. Using qPCR gene arrays, this study investigated the changes in cancer-specific genes as well as genes regulating mitochondrial quality control, metabolism, and oxidative stress in response to aggregation and hypoxia in our progressive ovarian cancer models representing slow- and fast-developing ovarian cancer. Aggregation increased the expression of anti-apoptotic, stemness, epithelial-mesenchymal transition (EMT), angiogenic, mitophagic, and reactive oxygen species (ROS) scavenging genes and functions, and decreased proliferation, apoptosis, metabolism, and mitochondrial content genes and functions. The incorporation of stromal vascular cells (SVF) from obese mice into the spheroids increased DNA repair and telomere regulatory genes that may represent a link between obesity and ovarian cancer risk. While glucose had no effect, glutamine was essential for aggregation and supported proliferation of the spheroid. In contrast, low glucose and hypoxic culture conditions delayed adhesion and outgrowth capacity of the spheroids independent of their phenotype, decreased mitochondrial mass and polarity, and induced a shift of mitochondrial dynamics towards mitophagy. However, these conditions did not reduce the appearance of polarized mitochondria at adhesion sites, suggesting that adhesion signals that either reversed mitochondrial fragmentation or induced mitobiogenesis can override the impact of low glucose and oxygen levels. Thus, the plasticity of the spheroids' phenotype supports viability during dissemination, allows for the adaptation to changing conditions such as oxygen and nutrient availability. This may be critical for the development of an aggressive cancer phenotype and, therefore, could represent druggable targets for clinical interventions.

Adaptation of metabolism to multicellular aggregation, hypoxia and obese stromal cell incorporation as potential measure of survival of ovarian metastases.

Ovarian metastases exfoliate from the primary tumor and it is thought that aggregation supports their survival in the peritoneal cavity during dissemination but the underlying mechanisms are not clearly identified. We have previously shown that ovarian cancer cells acquire an increasingly glycolytic and metabolic flexible phenotype during progression. In the present study, we investigated how hypoxia, aggregation, and the incorporation of the obese stromal vascular fraction (SVF) affect cellular metabolism and the response to common anti-cancer and anti-diabetic drugs. Our results show a reduction of glucose uptake, lactate secretion, cellular respiration and ATP synthesis in response to hypoxia and aggregation, suggesting that the observed reduced proliferation of cells aggregated into spheroids is the result of a down-regulation of respiration. Recruitment of SVF to spheroids increased the spheroids invasive capacity but reduced respiration only in the most aggressive cells. Further, aggregation and hypoxia reduced the response to the metabolic drugs AICAR and metformin, and the chemotherapeutic agents cisplatin and paclitaxel. Our results suggest that the adaptation of cellular metabolism may contribute to enhanced survival under non-permissive conditions, and that these metabolic alterations may provide targets for future interventions that aim to enhance the survival of women with metastatic ovarian cancer.

Effects of exercise or metformin on myokine concentrations in patients with breast and colorectal cancer: A phase II multi-centre factorial randomized trial.

BACKGROUND: Physical activity and metformin pharmacotherapy are associated with improved clinical outcomes in breast and colorectal cancer survivors. Myokines are cytokines secreted from skeletal muscle that may mediate these associations. METHODS: This hypothesis-generating analysis used biospecimens collected from a multi-centre 2 × 2 factorial randomized design of 116 patients with stage I-III breast and colorectal cancer who were randomized to 12 weeks of (1) aerobic exercise (moderate intensity titrated to 220 min/week); (2) metformin (850 mg daily for 2 weeks and then titrated to 850 mg twice per day); (3) aerobic exercise and metformin; or (4) control. Fourteen myokines were quantified using a multiplex panel. Myokine concentrations were log-transformed, and main effects analyses were conducted using linear mixed-effects regression models. The type I error rate was controlled with the Holm sequential testing procedure. RESULTS: Randomization to exercise increased leukaemia inhibitory factor (1.26 pg/mL, 95% confidence interval [CI]: 0.69, 1.84; adjusted P = 0.001) and interleukin-15 (2.23 pg/mL, 95% CI: 0.87, 3.60; adjusted P = 0.013) compared with randomization to no exercise. Randomization to metformin decreased apelin (-2.69 pg/mL, 95% CI: -4.31, -1.07; adjusted P = 0.014) and interleukin-15 (-1.74 pg/mL, 95% CI: -2.79, -0.69; adjusted P = 0.013) compared with randomization to no metformin. Metformin decreased myostatin, irisin, oncostatin M, fibroblast growth factor 21 and osteocrin; however, these changes were not statistically significant after correction for multiple comparisons. CONCLUSIONS: This pilot study demonstrates that randomization to exercise and metformin elicit unique effects on myokine concentrations in cancer patients. This hypothesis-generating observation warrants further basic, translational and clinical investigation and replication.

Effect of resistance training on physical function during chemotherapy in colon cancer.

BACKGROUND: The decline of physical function during chemotherapy predicts poor quality of life and premature death. It is unknown if resistance training prevents physical function decline during chemotherapy in colon cancer survivors. METHODS: This multicenter trial randomly assigned 181 colon cancer survivors receiving postoperative chemotherapy to home-based resistance training or usual care control. Physical function outcomes included the short physical performance battery, isometric handgrip strength, and the physical function subscale of the Medical Outcomes Short-Form 36-item questionnaire. Mixed models for repeated measures quantified estimated treatment differences. RESULTS: At baseline, participants had a mean (SD) age of 55.2 (12.8) years; 67 (37%) were 60 years or older, and 29 (16%) had a composite short physical performance battery score of no more than 9. Compared with usual care control, resistance training did not improve the composite short physical performance battery score (estimated treatment difference = -0.01, 95% confidence interval [CI] = -0.32 to 0.31; P = .98) or the short physical performance battery scores for balance (estimated treatment difference = 0.01, 95% CI = -0.10 to 0.11; P = .93), gait speed (estimated treatment difference = 0.08, 95% CI = -0.06 to 0.22; P = .28), and sit-to-stand (estimated treatment difference = -0.08, 95% CI = -0.29 to 0.13; P = .46). Compared with usual care control, resistance training did not improve isometric handgrip strength (estimated treatment difference = 1.50 kg, 95% CI = -1.06 to 4.05; P = .25) or self-reported physical function (estimated treatment difference = -3.55, 95% CI = -10.03 to 2.94); P = .28). The baseline short physical performance battery balance score (r = 0.21, 95% CI = 0.07 to 0.35) and handgrip strength (r = 0.23, 95% CI = 0.09 to 0.36) correlated with chemotherapy relative dose intensity. CONCLUSION: Among colon cancer survivors with relatively high physical functioning, random assignment to home-based resistance training did not prevent physical function decline during chemotherapy. CLINICAL TRIAL REGISTRATION: NCT03291951.

A randomized trial of aerobic exercise in colorectal cancer: Rationale, design, recruitment, and exercise adherence results.

BACKGROUND: Physical activity is associated with improved disease-free survival in colorectal cancer survivors. This report describes the purpose, design, recruitment, and exercise adherence results of the National Cancer Institute (NCI)-sponsored Exercise and Colorectal Cancer Treatment (EXACT) trial. METHODS: The primary objective of the EXACT trial is to determine if randomization to 150 min per week of moderate-intensity aerobic exercise reduces systemic inflammation among stage I-III colorectal cancer survivors compared with a waitlist control group over 12 weeks. Participants were provided with an in-home treadmill and heart rate monitor. Characteristics associated with randomization were identified using χ2 or Fisher's exact test for categorical variables and t-tests or analysis of covariance (ANCOVA). Exercise adherence was calculated as the total minutes exercised by total minutes prescribed. RESULTS: Between August 2019 and February 2023, 3082 colorectal cancer survivors were invited to participate, 89 were screened, and 60 were randomized to the study protocol. Younger age (P = 0.02), female sex (P = 0.002), white race (P = 0.01), proximal time since tumor resection (P = 0.02), and regional tumor stage (P < 0.001) were associated with study participation. Average exercise adherence was 92.2 % (95 % CI: 85.5, 98.8) and all study participants achieved ≥80 % exercise adherence. Endpoint data collection was completed for all participants in May 2023. CONCLUSION: The results from the EXACT trial will characterize the changes that occur from exercise to advance our understanding of the biological mechanisms by which exercise may prevent tumor recurrence and death in colorectal cancer survivors.

The dose-response effect of aerobic exercise on inflammation in colon cancer survivors.

Background: Physical activity after surgical resection for colon cancer is associated with significantly longer disease-free survival. Inflammation is hypothesized to mediate the association between physical activity and disease-free survival in colon cancer. Methods: In this exploratory analysis of a randomized dose-response trial, 39 colon cancer survivors who completed standard therapy were stratified by cancer stage and randomized in a 1:1:1 ratio to one of three treatment groups for 24 weeks of usual-care control, 150 min/wk of moderate-intensity aerobic exercise (low-dose), or 300 min/wk of moderate-intensity aerobic exercise (high-dose). Inflammation outcomes included high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL6), and soluble tumor necrosis factor-alpha receptor 2 (sTNFαR2). Mixed models for repeated measures were used to test the hypothesis that exercise was associated with dose-response reductions in inflammation; exploratory analyses examined treatment effects by cancer stage. Results: In the overall population, aerobic exercise was not associated with dose-response reductions in hs-CRP, IL6, or sTNFαR2. Cancer stage modified the association between randomized group and hs-CRP (P=0.022) and IL6 (P<0.001) but not sTNFαR2 (P=0.39). In stage I-II disease, compared to control, exercise was not associated with inflammation outcomes. In stage III disease, compared to control, low-dose exercise reduced hs-CRP: -35.4% (95% CI: -70.1, -0.7) and IL6: -29.6% (95% CI: -58.4, -0.8) but not sTNFαR2: 2.7% (95% CI: sTNFαR2: -15.7, 21.1); high-dose exercise was not associated with inflammation outcomes in stage III disease. Conclusion: This exploratory analysis offers preliminary data to support the hypothesis that inflammation may mediate the association between physical activity and disease-free survival in colon cancer. Clinical trial registration: clinicaltrials.gov, identifier NCT02250053.

Mitochondrial plasticity supports proliferative outgrowth and invasion of ovarian cancer spheroids during adhesion.

Background: Ovarian cancer cells aggregate during or after exfoliation from the primary tumor to form threedimensional spheroids. Spheroid formation provides a survival advantage during peritoneal dissemination in nutrient and oxygen-depleted conditions which is accompanied by a suppressed metabolic phenotype and fragmented mitochondria. Upon arrival to their metastatic sites, spheroids adhere to peritoneal organs and transition to a more epithelial phenotype to support outgrowth and invasion. In this study, we investigated the plasticity of mitochondrial morphology, dynamics, and function upon adhesion. Methods: Using our slow-developing (MOSE-L) and fast-developing (MOSE-LTICv) ovarian cancer models, we mimicked adhesion and reoxygenation conditions by plating the spheroids onto tissue culture dishes and changing culture conditions from hypoxia and low glucose to normoxia with high glucose levels after adhesion. We used Western Blot, microscopy and Seahorse analyses to determine the plasticity of mitochondrial morphology and functions upon adhesion, and the impact on proliferation and invasion capacities. Results: Independent of culture conditions, all spheroids adhered to and began to grow onto the culture plates. While the bulk of the spheroid was unresponsive, the mitochondrial morphology in the outgrowing cells was indistinguishable from cells growing in monolayers, indicating that mitochondrial fragmentation in spheroids was indeed reversible. This was accompanied by an increase in regulators of mitobiogenesis, PGC1a, mitochondrial mass, and respiration. Reoxygenation increased migration and invasion in both cell types but only the MOSE-L responded with increased proliferation to reoxygenation. The highly aggressive phenotype of the MOSE-LTICv was characterized by a relative independence of oxygen and the preservation of higher levels of proliferation, migration and invasion even in limiting culture conditions but a higher reliance on mitophagy. Further, the outgrowth in these aggressive cells relies mostly on proliferation while the MOSE-L cells both utilize proliferation and migration to achieve outgrowth. Suppression of proliferation with cycloheximide impeded aggregation, reduced outgrowth and invasion via repression of MMP2 expression and the flattening of the spheroids. Discussion: Our studies indicate that the fragmentation of the mitochondria is reversible upon adhesion. The identification of regulatory signaling molecules and pathways of these key phenotypic alterations that occur during primary adhesion and invasion is critical for the identification of druggable targets for therapeutic intervention to prevent aggressive metastatic disease.

Metabolic Reprogramming of Ovarian Cancer Spheroids during Adhesion.

Ovarian cancer remains a deadly disease and its recurrence disease is due in part to the presence of disseminating ovarian cancer aggregates not removed by debulking surgery. During dissemination in a dynamic ascitic environment, the spheroid cells' metabolism is characterized by low respiration and fragmented mitochondria, a metabolic phenotype that may not support secondary outgrowth after adhesion. Here, we investigated how adhesion affects cellular respiration and substrate utilization of spheroids mimicking early stages of secondary metastasis. Using different glucose and oxygen levels, we investigated cellular metabolism at early time points of adherence (24 h and less) comparing slow and fast-developing disease models. We found that adhesion over time showed changes in cellular energy metabolism and substrate utilization, with a switch in the utilization of mostly glutamine to glucose but no changes in fatty acid oxidation. Interestingly, low glucose levels had less of an impact on cellular metabolism than hypoxia. A resilience to culture conditions and the capacity to utilize a broader spectrum of substrates more efficiently distinguished the highly aggressive cells from the cells representing slow-developing disease, suggesting a flexible metabolism contributes to the stem-like properties. These results indicate that adhesion to secondary sites initiates a metabolic switch in the oxidation of substrates that could support outgrowth and successful metastasis.

Progression-Mediated Changes in Mitochondrial Morphology Promotes Adaptation to Hypoxic Peritoneal Conditions in Serous Ovarian Cancer.

Ovarian cancer is the deadliest gynecological cancer in women, with a survival rate of less than 30% when the cancer has spread throughout the peritoneal cavity. Aggregation of cancer cells increases their viability and metastatic potential; however, there are limited studies that correlate these functional changes to specific phenotypic alterations. In this study, we investigated changes in mitochondrial morphology and dynamics during malignant transition using our MOSE cell model for progressive serous ovarian cancer. Mitochondrial morphology was changed with increasing malignancy from a filamentous network to single, enlarged organelles due to an imbalance of mitochondrial dynamic proteins (fusion: MFN1/OPA1, fission: DRP1/FIS1). These phenotypic alterations aided the adaptation to hypoxia through the promotion of autophagy and were accompanied by changes in the mitochondrial ultrastructure, mitochondrial membrane potential, and the regulation of reactive oxygen species (ROS) levels. The tumor-initiating cells increased mitochondrial fragmentation after aggregation and exposure to hypoxia that correlated well with our previously observed reduced growth and respiration in spheroids, suggesting that these alterations promote viability in non-permissive conditions. Our identification of such mitochondrial phenotypic changes in malignancy provides a model in which to identify targets for interventions aimed at suppressing metastases.