Cancer cachexia and anabolic interventions: a case report

The roles of P-selectin in cancer cachexia

P-selectin, a cell adhesion molecule of the selectin family, is expressed on the surface of activated endothelial cells (ECs) and platelets. Binding of P-selectin to P-selectin glycoprotein ligand-1 (PSGL-1) supports the leukocytes capture and rolling on stimulated ECs and increases the aggregation of leukocytes and activated platelets. Cancer cachexia is a systemic inflammation disorder characterized by metabolic disturbances, reduced body weight, loss of appetite, fat depletion, and progressive muscle atrophy. Cachexia status is associated with increased pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), which activates ECs to release P-selectin. Single-nucleotide polymorphisms (SNPs) loci of P-selectin encoding gene SELP are associated with higher level of plasma P-selectin and increase the susceptibility to cachexia in cancer patients. Elevated P-selectin expression has been observed in the hypothalamus, liver, and gastrocnemius muscle in animal models with cancer cachexia. Increased P-selectin may cause excessive inflammatory processes, muscle atrophy, and blood hypercoagulation, thus facilitating the development of cancer cachexia. In this review, physiological functions of P-selectin and its potential roles in cancer cachexia have been summarized. We also discuss the therapeutic potential of P-selectin inhibitors for the treatment of cancer cachexia.

[Whey protein and caseinate supplementation in oncological patients undergoing elective surgery for the modification of functional capacity]

INTRODUCTION

the nutritional intervention has become a critical point to achieve the reduction of perioperative morbidity and mortality in cancer patients. There are different factors that will play a fundamental role in the evolution and prognosis of this pathology, being the state of nutrition and diet a cornerstone in these aspects.

OBJECTIVE

to evaluate the perioperative effect of whey protein isolate (WPI) and calcium caseinate (CaCNT) in cancer patients undergoing elective surgery.

METHODS

randomized controlled clinical trial with three groups: the control group (n = 15), consisting in conventional management by the oncology surgery services, and two intervention groups, one with calcium caseinate supplementation (n = 15) and another one with whey protein isolate supplementation (n = 15) for six weeks perioperatively. Handgrip strength, six-minute walk, and body composition were assessed pre and postoperatively.

RESULTS

those who were supplemented with WPI maintained their handgrip strength and showed less extracellular water (p < 0.02); also an increase in visceral mass was shown (p < 0.02). Finally, a correlation was found with variables associated with body composition and patient evolution when compared to the control group.

CONCLUSIONS

nutritional supplementation needs to be approached from the functional and metabolic point of view to identify factors that have a favorable impact, as well as the distinction between carcinoma and the type of supplementation to be implemented.

The effectiveness of whey proteins in prevention and treatment of cancer: a review

Cancer prevalence is rising rapidly around the globe, contributing immensely to the burden on health systems, hence the search for more effective and selective treatments still remains enticing. Whey, as a natural source, has received extensive focus in recent years because of its intriguing applications to health benefits. Growing consumer appreciation of the nutraceutical effects of whey components makes them an attractive field within cancer research. Whey is a valuable source of superior-quality proteins, lactose, vitamins, and minerals that contribute to proper nutrition as well as help hamper illness and even complement certain disease-related therapy prognosis. As a result, industry leaders and dairy producers are devising new ways to valorize it. Great emphasis on cancer prevention and treatment has been given to whey protein (WP) by the scientific community. WP intake has been proven to induce anti-cancer effects in various in vitro and in vivo studies. Nutritionists and dietitians are now enormously endorsing the role of WP in the therapeutic field, notably for cancer cachexia management. However, human intervention studies with WP are in their infancy and remain to be established with different tumor entities to provide valid proof of its ability to act as a coadjuvant in cancer treatment.

Whey Proteins and Its Derivatives: Bioactivity, Functionality, and Current Applications

With the increased consumer demand for nutritional foods, it is important to develop value-added products, which will not only catch the attention of a wider consumer group but also provide greater benefits in terms of enhanced nutrition and functionality. Milk whey proteins are one of the most valued constituents due to their nutritional and techno-functional attributes. Whey proteins are rich in bioactive peptides, possessing bioactive properties such as being antioxidant and antihypertensive as well as having antimicrobial activities, which, when ingested, confers several health benefits. These peptides have the potential to be used as an active food ingredient in the production of functional foods. In addition to their bioactivities, whey proteins are known to possess enhanced functional attributes that allow them to be utilized in broad applications, such as an encapsulating agent or carrier materials to entrap bioactive compounds, emulsification, and in edible and active packaging. Hence, over the recent years, several whey protein-based ingredients have been developed and utilized in making formulations for a wide range of foods to harness their beneficial properties. This review highlights the bioactive properties, functional characteristics, associated processing limitations, and applications of different whey protein fractions and derivatives in the field of food formulations, encapsulation, and packaging.

A Phase I Randomized Clinical Trial of Evidence-Based, Pragmatic Interventions to Improve Functional Recovery After Hospitalization in Geriatric Patients

BACKGROUND

Physical function declines during hospitalization in geriatric patients, increasing the risk of loss of independence. There is a need for evidence-based, pragmatic interventions to improve functional recovery of older adults following acute hospitalization. Here, we report the results of a Phase I randomized clinical trial designed to determine safety and effect size of protein supplementation, exercise, and testosterone interventions on 30-day post-discharge functional recovery and readmissions in geriatric patients.

METHODS

A total of 100 patients admitted to the University of Texas Medical Branch hospital for an acute medical illness were randomized to one of five intervention groups: isocaloric placebo, whey protein supplement, in-home rehabilitation + placebo, in-home rehabilitation + whey protein, or testosterone. Primary outcome measure was the change from baseline in short physical performance battery score at 1 and 4 weeks post-discharge. Secondary outcomes were changes in body composition, activities of daily living, and 30-day readmissions. Comparisons were made across study groups and between placebo and all active intervention groups.

RESULTS

Four weeks post-discharge, the short physical performance battery total score and balance score increased more in active intervention groups than placebo group (p < .05). There were no significant differences in change in body composition or activities of daily living across groups or between active intervention groups and placebo group. Readmission rates were highest in placebo (28%), followed by rehabilitation + placebo (15%), whey protein (12%), rehabilitation + whey protein (11%), and testosterone (5%). There was a trend for lower readmission rates in all active intervention groups (11%) versus placebo group (28%).

CONCLUSIONS

Findings from this Phase I clinical trial suggest that pragmatic, evidence-based interventions may accelerate recovery from acute hospitalization in geriatric patients. These data provide essential information to design larger randomized controlled trials to test the effectiveness of these interventions.

The Influence of Omega-3 Fatty Acids on Skeletal Muscle Protein Turnover in Health, Disuse, and Disease

Ingestion of omega-3 fatty acids is known to exert favorable health effects on a number of biological processes such as improved immune profile, enhanced cognition, and optimized neuromuscular function. Recently, data have emerged demonstrating a positive influence of omega-3 fatty acid intake on skeletal muscle. For instance, there are reports of clinically-relevant gains in muscle size and strength in healthy older persons with omega-3 fatty acid intake as well as evidence that omega-3 fatty acid ingestion alleviates the loss of muscle mass and prevents decrements in mitochondrial respiration during periods of muscle-disuse. Cancer cachexia that is characterized by a rapid involuntary loss of lean mass may also be attenuated by omega-3 fatty acid provision. The primary means by which omega-3 fatty acids positively impact skeletal muscle mass is via incorporation of eicosapentaenoic acid (EPA; 20:5n−3) and docosahexaenoic acid (DHA; 22:6n−3) into membrane phospholipids of the sarcolemma and intracellular organelles. Enrichment of EPA and DHA in these membrane phospholipids is linked to enhanced rates of muscle protein synthesis, decreased expression of factors that regulate muscle protein breakdown, and improved mitochondrial respiration kinetics. However, exactly how incorporation of EPA and DHA into phospholipid membranes alters these processes remains unknown. In this review, we discuss the interaction between omega-3 fatty acid ingestion and skeletal muscle protein turnover in response to nutrient provision in younger and older adults. Additionally, we examine the role of omega-3 fatty acid supplementation in protecting muscle loss during muscle-disuse and in cancer cachexia, and critically evaluate the molecular mechanisms that underpin the phenotypic changes observed in skeletal muscle with omega-3 fatty acid intake.

Efficacy of Testosterone plus NASA Exercise Countermeasures during Head-Down Bed Rest

INTRODUCTION

Prolonged confinement to head-down bed rest (HDBR) results in musculoskeletal losses similar to those observed during long-duration space flight. Exercise countermeasures by themselves have not completely prevented the deleterious losses in muscle mass or function in HDBR or space flight.

PURPOSE

The objective was to investigate the safety and efficacy of intermittent, low-dose testosterone treatment in conjunction with NASA exercise (SPRINT) countermeasures during 70 d of 6° HDBR.

METHODS

Healthy men (35 ± 8 yr) were randomized into one of three groups that remained inactive (CON) or performed exercise 6 d·wk in addition to receiving either placebo (PEX) or testosterone treatment (TEX, 100 mg·wk). Testosterone/placebo injections were administered once a week for 2 wk, followed by 2 wk off and so on, during HDBR.

RESULTS

Total, leg, and trunk lean body mass (LBM) consistently decreased in CON, increased in TEX, and had little or no changes in PEX. Total, leg, and trunk fat mass consistently increased in CON and PEX and decreased in TEX. Leg strength decreased in CON, whereas PEX and TEX were protected against loss in strength. Changes in leg LBM correlated positively with changes in leg muscle strength.

CONCLUSIONS

Addition of a testosterone countermeasure enhanced the preventative actions of exercise against body composition changes during long-term HDBR in healthy eugonadal men. This is the first report to demonstrate that cycled, low-dose testosterone treatment increases LBM under conditions of strict exercise control. These results are clinically relevant to the development of safe and effective therapies against muscle atrophy during long-term bed rest, aging, and disease where loss of muscle mass and strength is a risk. The potential space flight applications of such countermeasure combinations deserve further investigations.

Whey protein in cancer therapy: A narrative review

Cancer remains a public health challenge in the identification and development of ideal pharmacological therapies and dietary strategies. The use of whey protein as a dietary strategy is widespread in the field of oncology. The two types of whey protein, sweet or acid, result from several processing techniques and possess distinct protein subfraction compositions. Mechanistically, whey protein subfractions have specific anti-cancer effects. Alpha-lactalbumin, human α-lactalbumin made lethal to tumor cell, bovine α-lactalbumin made lethal to tumor cell, bovine serum albumin, and lactoferrin are whey protein subfractions with potential to hinder tumor pathways. Such effects, however, are principally supported by studies performed in vitro and/or in vivo. In clinical practice, whey protein intake-induced anti-cancer effects are indiscernible. However, whey protein supplementation represents a practical, feasible, and cost-effective approach to mitigate cancer cachexia syndrome. The usefulness of whey protein is evidenced by a greater leucine content and the potential to modulate IGF-1 concentrations, representing important factors towards musculoskeletal hypertrophy. Further clinical trials are warranted and needed to establish the effects of whey protein supplementation as an adjuvant to cancer therapy.

A Randomized Controlled Pilot Trial of Interventions to Improve Functional Recovery After Hospitalization in Older Adults: Feasibility and Adherence

Background

Hospitalization is a major risk factor for functional decline, disability, loss of independence, and mortality in older adults. Evidence-based interventions to improve functional recovery from hospitalization are difficult to evaluate and implement in geriatric patients. The goal of this pilot study was to test the feasibility of recruiting geriatric inpatients and implementing pragmatic interventions to improve physical function following hospitalization.

Methods

Enrolled subjects were randomized to one of five 30-day posthospitalization interventions: isocaloric placebo (P), whey protein supplement (W), in-home rehabilitation+placebo (R+P), rehabilitation+whey protein (R+W), or testosterone (T). Data were collected from a single-site university hospital to determine: (i) institution-based feasibility (nonmodifiable factors including number of patients screened, eligible, contacted) and (ii) patient-based feasibility (modifiable factors including number of patients refusing, enrolled, randomized, intervention adherence, and withdrawal).

Results

From January 2014 to July 2016, 4,533 patients were chart screened; 594 (13.1%) were eligible to participate; 384 eligible subjects were contacted; 113 were enrolled; and 100 were randomized. Supplement adherence was 75% and was not different by age, education, level of independence, depression, supplement type, or dual intervention, but was significantly higher in subjects who completed the intervention (p < .01). Rehabilitation session adherence was 77% and did not vary significantly by age, education, level of independence, depression, or supplement type, but was significantly higher for sessions directly supervised (p < .01). Adherence was 100% in the testosterone arm with 94.7% of injections given within 24 hours of discharge.

Conclusions

Findings from this clinical trial indicate that posthospitalization interventions in geriatric patients are feasible at both the institution and patient level.

Understanding the Role of Exercise in Cancer Cachexia Therapy

Cachexia, the unintentional loss of body weight, is prevalent in many cancer types, and the associated skeletal muscle mass depletion increases patient morbidity and mortality. While anorexia can be present, cachexia is not reversible with nutritional therapies alone. Pharmacological agents have been proposed to treat this condition, but there are currently no approved treatments. Nonetheless, the hallmark characteristics associated with cancer cachexia remain viable foundations for future therapies. Regular physical activity holds a promising future as a nonpharmacological alternative to improve patient survival through cachexia prevention. Evidence suggests exercise training is beneficial during cancer treatment and survival. However, the mechanistic examination of cachectic skeletal muscle's response to exercise is both needed and justified. The primary objective of this review is to discuss the role of exercise for the prevention and treatment of cancer-associated muscle wasting. Initially, we provide an overview of systemic alterations induced by cancer and their role in the regulation of wasting processes during cachexia progression. We then discuss how exercise could alter disrupted regulatory pathways related to growth and metabolism during cancer-induced muscle atrophy. Last, we outline current exercise prescription guidelines and how exercise could be a potential behavioral therapy to curtail cachexia development in cancer patients.

Resistance Exercise's Ability to Reverse Cancer-Induced Anabolic Resistance

Skeletal muscle has the dynamic capability to modulate protein turnover in response to anabolic stimuli, such as feeding and contraction. We propose that anabolic resistance, the suppressed ability to induce protein synthesis, is central to cancer-induced muscle wasting. Furthermore, we propose that resistance exercise training has the potential to attenuate or treat cancer-induced anabolic resistance through improvements in oxidative metabolism.

A randomized trial of adjunct testosterone for cancer-related muscle loss in men and women

BACKGROUND

Cancer cachexia negatively impacts cancer-related treatment options, quality of life, morbidity, and mortality, yet no established therapies exist. We investigated the anabolic properties of testosterone to limit the loss of body mass in late stage cancer patients undergoing standard of care cancer treatment.

METHODS

A randomized, double-blind, placebo-controlled phase II clinical trial was undertaken to assess the potential therapeutic role of adjunct testosterone to limit loss of body mass in patients with squamous cell carcinoma of the cervix or head and neck undergoing standard of care treatment including chemotherapy and chemoradiation. Patients were randomly assigned in blocks to receive weekly injections of either 100 mg testosterone enanthate or placebo for 7 weeks. The primary outcome was per cent change in lean body mass, and secondary outcomes included assessment of quality of life, tests of physical performance, muscle strength, daily activity levels, resting energy expenditure, nutritional intake, and overall survival.

RESULTS

A total of 28 patients were enrolled, 22 patients were studied to completion, and 21 patients were included in the final analysis (12 placebo, nine testosterone). Adjunct testosterone increased lean body mass by 3.2% (95% confidence interval [CI], 0-7%) whereas those receiving placebo lost 3.3% (95% CI, -7% to 1%, P = 0.015). Although testosterone patients maintained more favourable body condition, sustained daily activity levels, and showed meaningful improvements in quality of life and physical performance, overall survival was similar in both treatment groups.

CONCLUSIONS

In patients with advanced cancer undergoing the early phase of standard of care therapy, adjunct testosterone improved lean body mass and was also associated with increased quality of life, and physical activity compared with placebo.

Linking Cancer Cachexia-Induced Anabolic Resistance to Skeletal Muscle Oxidative Metabolism

Cancer cachexia, a wasting syndrome characterized by skeletal muscle depletion, contributes to increased patient morbidity and mortality. While the intricate balance between protein synthesis and breakdown regulates skeletal muscle mass, the suppression of basal protein synthesis may not account for the severe wasting induced by cancer. Therefore, recent research has shifted to the regulation of “anabolic resistance,” which is the impaired ability of nutrition and exercise to stimulate protein synthesis. Emerging evidence suggests that oxidative metabolism can regulate both basal and induced muscle protein synthesis. While disrupted protein turnover and oxidative metabolism in cachectic muscle have been examined independently, evidence suggests a linkage between these processes for the regulation of cancer-induced wasting. The primary objective of this review is to highlight the connection between dysfunctional oxidative metabolism and cancer-induced anabolic resistance in skeletal muscle. First, we review oxidative metabolism regulation of muscle protein synthesis. Second, we describe cancer-induced alterations in the response to an anabolic stimulus. Finally, we review a role for exercise to inhibit cancer-induced anabolic suppression and mitochondrial dysfunction.

Amelioration of sexual behavior and motor activity deficits in a castrated rodent model with a selective androgen receptor modulator SARM-2f

Sarcopenia and cachexia present characteristic features of a decrease in skeletal muscle mass and strength, anorexia, and lack of motivation. Treatments for these diseases have not yet been established, although selective androgen receptor modulators (SARMs) are considered as therapeutic targets. We previously reported that a novel SARM compound, SARM-2f, exhibits anabolic effect on muscles, with less stimulatory effect on prostate weight compared with testosterone, in rat Hershberger assays and cancer cachexia models. In this study, we studied the mechanism of action for SARM-2f selectivity and also assessed whether the muscle increase by this compound might lead to improvement of muscle function and physical activity. First, we examined the tissue distribution of SARM-2f. Tissue concentration was 1.2-, 1.6-, and 1.9-fold as high as the plasma concentration in the levator ani muscle, brain, and prostate, respectively. This result showed that the tissue-selective pharmacological effect did not depend on SARM-2f concentration in the tissues. The ability of SARM-2f to influence androgen receptor (AR)-mediated transcriptional activation was examined by reporter assays using human normal prostate epithelial cells (PrEC) and skeletal muscle cells (SKMC). SARM-2f exerted higher activity against AR in SKMC than in PrEC. Mammalian two hybrid assays showed different co-factor recruitment patterns between SARM-2f and dihydrotestosterone. Next, we studied the effect of SARM-2f on motivation and physical functions such as sexual behavior and motor activities in castrated rat or mouse models. SARM-2f restored the sexual behavior that was lost by castration in male rats. SARM-2f also increased voluntary running distance and locomotor activities. These results suggest that tissue-specific AR regulation by SARM-2f, but not tissue distribution, might account for its tissue specific androgenic effect, and that the muscle mass increase by SARM-2f leads to improvement of physical function. Together, these findings suggest that SARM-2f might represent an effective treatment for sarcopenia and cachexia.

Prevention of body weight loss and sarcopenia by a novel selective androgen receptor modulator in cancer cachexia models

Cancer cachexia is a syndrome that impairs the quality of life and overall survival of patients, and thus the effectiveness of anticancer agents. There are no effective therapies for cancer cachexia due to the complexity of the syndrome, and insufficient knowledge of its pathogenesis results in difficulty establishing appropriate animal models. Previously, promising results have been obtained in clinical trials using novel agents including the ghrelin receptor agonist anamorelin, and the selective androgen receptor modulator (SARM) enobosarm to treat cachexia in patients with cancer. The present study examined the pharmacological effects of SARM-2f, a novel non-steroidal small molecule SARM, in animal models. SARM-2f increased body and skeletal muscle weight without significantly increasing the weight of the seminal vesicles or prostates of the castrated male rats. In the mice with tumor necrosis factor α-induced cachexia, SARM-2f and TP restored body weight, carcass weight, and food consumption rate. In the C26 and G361 cancer cachexia animal models, body and carcass weight, lean body mass, and the weight of the levator ani muscle were increased by SARM-2f and TP treatments. Tissue selectivity of SARM-2f was also observed in these animal models. The results demonstrate the anabolic effects of SARM-2f in a cytokine-induced cachexia model and other cancer cachexia models, and suggest that SARM-2f may be a novel therapeutic option for cachexia in patients with cancer.

The role of sex steroid hormones in the pathophysiology and treatment of sarcopenia

Sex steroids influence the maintenance and growth of muscles. Decline in androgens, estrogens and progesterone by aging leads to the loss of muscular function and mass, sarcopenia. These steroid hormones can interact with different signaling pathways through their receptors. To date, sex steroid hormone receptors and their exact roles are not completely defined in skeletal and smooth muscles. Although numerous studies focused on the effects of sex steroid hormones on different types of cells, still many unexplained molecular mechanisms in both skeletal and smooth muscle cells remain to be investigated. In this paper, many different molecular mechanisms that are activated or inhibited by sex steroids and those that influence the growth, proliferation, and differentiation of skeletal and smooth muscle cells are reviewed. Also, the similarities of cellular and molecular pathways of androgens, estrogens and progesterone in both skeletal and smooth muscle cells are highlighted. The reviewed signaling pathways and participating molecules can be targeted in the future development of novel therapeutics.

Is Cancer Cachexia Attributed to Impairments in Basal or Postprandial Muscle Protein Metabolism?

Cachexia is a significant clinical problem associated with very poor quality of life, reduced treatment tolerance and outcomes, and a high mortality rate. Mechanistically, any sizeable loss of skeletal muscle mass must be underpinned by a structural imbalance between muscle protein synthesis and breakdown rates. Recent data indicate that the loss of muscle mass with aging is, at least partly, attributed to a blunted muscle protein synthetic response to protein feeding. Whether such anabolic resistance is also evident in conditions where cachexia is present remains to be addressed. Only few data are available on muscle protein synthesis and breakdown rates in vivo in cachectic cancer patients. When calculating the theoretical changes in basal or postprandial fractional muscle protein synthesis and breakdown rates that would be required to lose 5% of body weight within a six-month period, we can define the changes that would need to occur to explain the muscle mass loss observed in cachectic patients. If changes in both post-absorptive and postprandial muscle protein synthesis and breakdown rates contribute to the loss of muscle mass, it would take alterations as small as 1%–2% to induce a more than 5% decline in body weight. Therefore, when trying to define impairments in basal and/or postprandial muscle protein synthesis or breakdown rates using contemporary stable isotope methodology in cancer cachexia, we need to select large homogenous groups of cancer patients (>40 patients) to allow us to measure physiological and clinically relevant differences in muscle protein synthesis and/or breakdown rates. Insight into impairments in basal or postprandial muscle protein synthesis and breakdown rates in cancer cachexia is needed to design more targeted nutritional, pharmaceutical and/or physical activity interventions to preserve skeletal muscle mass and, as such, to reduce the risk of complications, improve quality of life, and lower mortality rates during the various stages of the disease.

Identifying effective and feasible interventions to accelerate functional recovery from hospitalization in older adults: A randomized controlled pilot trial

Hospitalization induces functional decline in older adults. Many geriatric patients fail to fully recover physical function after hospitalization, which increases the risk of frailty, disability, dependence, re-hospitalization, and mortality. There is a lack of evidence-based therapies that can be implemented following hospitalization to accelerate functional improvements. The aims of this Phase I clinical trial are to determine 1) the effect size and variability of targeted interventions in accelerating functional recovery from hospitalization and 2) the feasibility of implementing such interventions in community-dwelling older adults. Older patients (≥65years, n=100) will be recruited from a single site during hospitalization for an acute medical condition. Subjects will be randomized to one of five interventions initiated immediately upon discharge: 1. protein supplementation, 2. in-home rehabilitation plus placebo supplementation, 3. in-home rehabilitation plus protein supplementation, 4. single testosterone injection, or 5. isocaloric placebo supplementation. Testing will occur during hospitalization (baseline) and at 1 and 4weeks post-discharge. Each testing session will include measures of muscle strength, physical function/performance, body composition, and psychological function. Physical activity levels will be continuously monitored throughout study participation. Feasibility will be determined through collection of the number of eligible, contacted, and enrolled patients; intervention adherence and compliance; and reasons for declining enrollment and study withdrawal. This research will determine the feasibility of post-hospitalization strategies to improve physical function in older adults. These results will also provide a foundation for performing larger, multi-site clinical trials to improve physical function and reduce readmissions in geriatric patents.

Testosterone enables growth and hypertrophy in fusion impaired myoblasts that display myotube atrophy: deciphering the role of androgen and IGF-I receptors

We have previously highlighted the ability of testosterone (T) to improve differentiation and myotube hypertrophy in fusion impaired myoblasts that display reduced myotube hypertrophy via multiple population doublings (PD) versus their parental controls (CON); an observation which is abrogated via PI3K/Akt inhibition (Deane et al. 2013). However, whether the most predominant molecular mechanism responsible for T induced hypertrophy occurs directly via androgen receptor or indirectly via IGF-IR/PI3K/Akt pathway is currently debated. PD and CON C₂C₁₂ muscle cells were exposed to low serum conditions in the presence or absence of T (100 nM) ± inhibitors of AR (flutamide/F, 40 μm) and IGF-IR (picropodophyllin/PPP, 150 nM) for 72 h and 7 days (early/late muscle differentiation respectively). T increased AR and Akt abundance, myogenin gene expression, and myotube hypertrophy, but not ERK1/2 activity in both CON and PD cell types. Akt activity was not increased significantly in either cell type with T. Testosterone was also unable to promote early differentiation in the presence of IGF-IR inhibitor (PPP) yet still able to promote appropriate later increases in myotube hypertrophy and AR abundance despite IGF-IR inhibition. The addition of the AR inhibitor powerfully attenuated all T induced increases in differentiation and myotube hypertrophy with corresponding reductions in AR abundance, phosphorylated Akt, ERK1/2 and gene expression of IGF-IR, myoD and myogenin with increases in myostatin mRNA in both cell types. Interestingly, despite basally reduced differentiation and myotube hypertrophy, PD cells showed larger T induced increases in AR abundance vs. CON cells, a response abrogated in the presence of AR but not IGF-IR inhibitors. Furthermore, T induced increases in Akt abundance were sustained despite the presence of IGF-IR inhibition in PD cells only. Importantly, flutamide alone reduced IGF-IR mRNA in both cell types across time points, with an observed reduction in activity of ERK and Akt, suggesting that IGF-IR was transcriptionally regulated by AR. However, where testosterone increased AR protein content there was no increases observed in IGF-IR gene expression. This suggested that sufficient AR was important to enable normal IGF-IR expression and downstream signalling, yet elevated levels of AR due to testosterone had no further effect on IGF-IR mRNA, despite testosterone increasing Akt abundance in the presence of IGF-IR inhibitor. In conclusion, testosterones ability to improve differentiation and myotube hypertrophy occurred predominately via increases in AR and Akt abundance in both CON and PD cells, with fusion impaired cells (PD) showing an increased responsiveness to T induced AR levels. Finally, T induced increases in myotube hypertrophy (but not early differentiation) occurred independently of upstream IGF-IR input, however it was apparent  that normal AR function in basal conditions was required for adequate IGF-IR gene expression and downstream ERK/Akt activity.

Emerging trends in nutraceutical applications of whey protein and its derivatives

The looming food insecurity demands the utilization of nutrient-rich residues from food industries as value-added products. Whey, a dairy industry waste has been characterized to be excellent nourishment with an array of bioactive components. Whey protein comprises 20 % of total milk protein and it is rich in branched and essential amino acids, functional peptides, antioxidants and immunoglobulins. It confers benefits against a wide range of metabolic diseases such as cardiovascular complications, hypertension, obesity, diabetes, cancer and phenylketonuria. The protein has been validated to boost recovery from resistance exercise-injuries, stimulate gut physiology and protect skin against detrimental radiations. Apart from health invigoration, whey protein has proved its suitability as fat replacer and emulsifier. Further, its edible and antimicrobial packaging potential renders its highly desirable in food as well as pharmaceutical sectors. Considering the enormous nutraceutical worth of whey protein, this review emphasizes on its established and emerging biological roles. Present and future scopes in food processing and dietary supplement formulation are discussed. Associated hurdles are identified and how technical advancement might augment its applications are explored. This review is expected to provide valuable insight on whey protein-fortified functional foods, associated technical hurdles and scopes of improvement.

When and when not to use testosterone for palliation in cancer care

Hypogonadism is common throughout the illness trajectory of patients with cancer. About two thirds of male patients with advanced cancer have hypothalamic-pituitary-gonadal dysfunction and low testosterone levels. Chronic inflammation, comorbidities, cachexia, chemotherapy, and medications such as opioids, megestrol acetate, and corticosteroids contribute to primary and secondary hypogonadism. Studies have reported increased symptom burden, diminished quality of life, and poor prognosis associated with low testosterone levels in males with cancer. The Endocrine Society has published clinical practice guidelines for replacing testosterone in symptomatic patients with chronic illness and in patients receiving opioids; however, the role of testosterone therapy specifically in patients with cancer is not addressed. This review explores the potential benefits and limitations of testosterone replacement on the basis of current evidence.

Translational studies in older men using testosterone to treat sarcopenia

Sarcopenia is the loss of skeletal muscle mass and strength that occurs with aging. Our research group has found an efficacious administration paradigm using testosterone to combat sarcopenia in humans. In addition, our research has uncovered an important regulatory enzyme of inflammation, nuclear factor-κB-inducing kinase that may regulate human skeletal muscle catabolism, and that appears to be counter-regulated by administration of standard doses of testosterone. This is important because a number of age-related clinical circumstances trigger acute and chronic muscle loss including cancer, chronic obstructive pulmonary disease, hospitalization, acute and chronic illness, and diseases in which systemic inflammation occurs. Moreover, it is often the treatment itself that can induce muscle loss. For example, glucocorticoids are tremendously effective at reducing inflammation and are a frontline therapy for many inflammatory-based diseases, yet paradoxically trigger muscle loss. We will discuss our research findings and the clinical significance of our human clinical translational research with testosterone.

Impaired hypertrophy in myoblasts is improved with testosterone administration

We investigated the ability of testosterone (T) to restore differentiation in multiple population doubled (PD) murine myoblasts, previously shown to have a reduced differentiation in monolayer and bioengineered skeletal muscle cultures vs. their parental controls (CON) (Sharples et al., 2011, 2012 [7,26]). Cells were exposed to low serum conditions in the presence or absence of T (100nM)±PI3K inhibitor (LY294002) for 72h and 7 days (early and late muscle differentiation respectively). Morphological analyses were performed to determine myotube number, diameter (μm) and myonuclear accretion as indices of differentiation and myotube hypertrophy. Changes in gene expression for myogenin, mTOR and myostatin were also performed. Myotube diameter in CON and PD cells increased from 17.32±2.56μm to 21.02±1.89μm and 14.58±2.66μm to 18.29±3.08μm (P≤0.05) respectively after 72h of T exposure. The increase was comparable in both PD (+25%) and CON cells (+21%) suggesting a similar intrinsic ability to respond to exogenous T administration. T treatment also significantly increased myonuclear accretion (% of myotubes expressing 5+ nuclei) in both cell types after 7 days exposure (P≤0.05). Addition of PI3K inhibitor (LY294002) in the presence of T attenuated these effects in myotube morphology (in both cell types) suggesting a role for the PI3K pathway in T stimulated hypertrophy. Finally, PD myoblasts showed reduced responsiveness to T stimulated mRNA expression of mTOR vs. CON cells and T also reduced myostatin expression in PD myoblasts only. The present study demonstrates testosterone administration improves hypertrophy in myoblasts that basally display impaired differentiation and hypertrophic capacity vs. their parental controls, the action of testosterone in this model was mediated by PI3K/Akt pathway.