Impact of Pretreatment Weight Loss on Radiotherapy Utilization and Clinical Outcomes in Non-Small Cell Lung Cancer.

BACKGROUND: Cancer cachexia is a syndrome of unintentional weight loss resulting in progressive functional impairment. Knowledge of radiation therapy utilization in patients with cancer cachexia is limited. We evaluated the use of curative and palliative-intent radiation for the management of patients with non-small cell lung cancer (NSCLC) with cachexia to determine whether tumor-directed therapy affected cachexia-associated outcomes. METHODS: Using an Institutional Tumor Registry, we evaluated all patients with stages of NSCLC treated at a tertiary care system from 2006 to 2013. We adopted the international consensus definition for cachexia, with staging designated by the registry and positron emission tomography. Radiotherapy delivery and intent were retrospectively assessed. RESULTS: In total, 1330 patients with NSCLC were analyzed. Curative-intent radiotherapy was utilized equally between patients with cachexia and non-cachexia with stages I to III NSCLC. Conversely, significantly more patients with stage IV disease and cachexia received palliative radiotherapy versus those without (74% vs 63%, P = 0.006). Cachexia-associated survival was unchanged irrespective of tumor-directed radiation therapy with curative or palliative intent. In fact, pretreatment cachexia was associated with reduced survival for patients with stage III NSCLC receiving curative-intent radiotherapy (median survival = 23.9 vs 15.0 mo, P = 0.009). Finally, multivariate analysis identified pretreatment cachexia as an independent variable associated with worsened survival (hazard ratio = 1.31, CI: 1.14,1.52). CONCLUSION: Patients with advanced NSCLC with cachexia received more palliative-intent radiation than those without weight loss. Tumor-directed therapy in either a curative or palliative approach failed to alter cachexia patient survival across all stages of the disease. These findings offer critical information on the appropriate utilization of radiation in the management of patients with NSCLC with cachexia.

Tumor loss-of-function mutations in STK11/LKB1 induce cachexia.

Cancer cachexia (CC), a wasting syndrome of muscle and adipose tissue resulting in weight loss, is observed in 50% of patients with solid tumors. Management of CC is limited by the absence of biomarkers and knowledge of molecules that drive its phenotype. To identify such molecules, we injected 54 human non-small cell lung cancer (NSCLC) lines into immunodeficient mice, 17 of which produced an unambiguous phenotype of cachexia or non-cachexia. Whole-exome sequencing revealed that 8 of 10 cachexia lines, but none of the non-cachexia lines, possessed mutations in serine/threonine kinase 11 (STK11/LKB1), a regulator of nutrient sensor AMPK. Silencing of STK11/LKB1 in human NSCLC and murine colorectal carcinoma lines conferred a cachexia phenotype after cell transplantation into immunodeficient (human NSCLC) and immunocompetent (murine colorectal carcinoma) models. This host wasting was associated with an alteration in the immune cell repertoire of the tumor microenvironments that led to increases in local mRNA expression and serum levels of CC-associated cytokines. Mutational analysis of circulating tumor DNA from patients with NSCLC identified 89% concordance between STK11/LKB1 mutations and weight loss at cancer diagnosis. The current data provide evidence that tumor STK11/LKB1 loss of function is a driver of CC, simultaneously serving as a genetic biomarker for this wasting syndrome.

Race, Ethnicity, and Socioeconomic Factors as Determinants of Cachexia Incidence and Outcomes in a Retrospective Cohort of Patients With Gastrointestinal Tract Cancer.

PURPOSE: Cachexia is a paraneoplastic syndrome of unintentional adipose and muscle tissue wasting with severe impacts to functionality and quality of life. Although health inequities across minority and socioeconomically disadvantaged groups are known, the role of these factors in cachexia progression is poorly characterized. This study aims to evaluate the relationship between these determinants and cachexia incidence and survival in patients with gastrointestinal tract cancer. METHODS: Through retrospective chart review from a prospective tumor registry, we established a cohort of 882 patients with gastroesophageal or colorectal cancer diagnosed between 2006 and 2013. Patient race, ethnicity, private insurance coverage, and baseline characteristics were evaluated through multivariate, Kaplan-Meier, and Cox regression analyses to determine associations with cachexia incidence and survival outcomes. RESULTS: When controlling for potentially confounding covariates (age, sex, alcohol and tobacco history, comorbidity score, tumor site, histology, and stage), Black (odds ratio [OR], 2.447; P < .0001) and Hispanic (OR, 3.039; P < .0001) patients are at an approximately 150% and 200%, respectively, greater risk of presenting with cachexia than non-Hispanic White patients. Absence of private insurance coverage was associated with elevated cachexia risk (OR, 1.439; P = .0427) compared to privately insured patients. Cox regression analyses with previously described covariates and treatment factors found Black race (hazard ratio [HR], 1.304; P = .0354) to predict survival detriments, while cachexia status did not reach significance (P = .6996). CONCLUSION: Our findings suggest that race, ethnicity, and insurance play significant roles in cachexia progression and related outcomes that are not accounted for by conventional predictors of health. Disproportionate financial burdens, chronic stress, and limitations of transportation and health literacy represent targetable factors for mitigating these health inequities.

Racial, Ethnic, and Socioeconomic Characteristics Independently Predict for Cachexia Risk and Associated Survival Outcomes in Stage IV NSCLC: A Brief Report.

Introduction: Cancer cachexia, found in more than a third of patients with NSCLC, directly leads to functional and survival detriments. As screening and interventions for cachexia and NSCLC improve, deficits in health care access and quality among patients disadvantaged by racial-ethnic and socioeconomic factors must be addressed. Methods: We retrospectively evaluated 957 patients diagnosed with having stage IV NSCLC between 2014 and 2020 in Dallas, Texas. Cachexia was retrospectively assessed by applying criteria for substantial unintentional weight loss in the time leading up to cancer diagnosis. Nonparametric, parametric, multivariate logistic regression, and Kaplan-Meier analyses were conducted to evaluate for variables potentially associated with cachexia incidence and survival. Results: In multivariate analysis including age, sex, comorbidities, body mass index, risk behaviors, and tumor characteristics, Black race and Hispanic ethnicity were independently associated with more than a 70% increased risk of presenting with cachexia at the time of NSCLC diagnosis (p < 0.05). When private insurance status was included as a covariate, this association was diminished for Hispanic patients only. Black patients presented with stage IV disease at an average of approximately 3 years younger than White patients (Kruskal-Wallis p = 0.0012; t test p = 0.0002). Cachexia status at diagnosis consistently predicted for survival detriments, further highlighting the importance of addressing differential cachexia risk across racial-ethnic groups. Conclusions: Fundamentally, our findings reveal elevated cachexia risk in Black and Hispanic patients with stage IV NSCLC with associated survival detriments. These differences are not fully accounted for by traditional determinants of health and suggest novel avenues for addressing oncologic health inequities.

A preponderance of gastrointestinal cancer patients transition into cachexia syndrome.

BACKGROUND: Cancer cachexia is frequently documented by self-reported, single time-point weight histories. This approach lacks the granularity needed to fully elucidate the progression of cachexia syndrome. This study aimed to longitudinally assess body weight changes pre- and post-cancer diagnosis in gastrointestinal (GI) cancer patients. METHODS: Body weights and relevant clinical data recorded in the electronic health record 12 months pre- and post-GI cancer (colorectal, gastroesophageal, hepatobiliary and pancreatic) diagnosis were extracted. Weight loss was categorized by the International Consensus Definition for cachexia. RESULTS: A total of 879 patients were included in the final cohort including patients diagnosed with colorectal (n = 317), hepatocellular (n = 185), biliary (n = 72), pancreatic (n = 186) or gastroesophageal (n = 119) cancer. Stage of disease was equally distributed. Patients without cachexia at diagnosis (n = 608) remained weight stable during the 12 months pre-diagnosis (+0.5 ± 0.5% body weight; P = 0.99). Patients with cachexia at diagnosis (n = 271) remained weight stable 6 to 12 months prior to diagnosis (+0.4 ± 0.8%; P > 0.9999) and lost 8.7 ± 0.6% (P < 0.0001) within the 6 months pre-diagnosis. Patients without cachexia at diagnosis lost more weight post-diagnosis (6.3 ± 0.6%) than patients with cachexia at diagnosis (4.7 ± 1.0%; P = 0.01). Pre-diagnosis weight trajectories did not differ between primary malignancies or stage of disease in patients without or with cachexia at diagnosis (all P ≥ 0.05). Post-diagnosis weight trajectories did differ by primary malignancy (P ≤ 0.0002) and stage (P < 0.0001). In both patients without and with cachexia at diagnosis, colorectal patients lost the least amount of weight post-diagnosis and gastroesophageal patients lost the most amount of weight post-diagnosis. Stage 4 patients without or with cachexia at diagnosis lost the most weight post-diagnosis (P ≤ 0.0003). Regardless of cachexia status at diagnosis, patients lost more weight when treated with systemic therapy (7.1 ± 0.7%; P < 0.0001; n = 419) or radiation therapy (8.4 ± 1.4%; P = 0.02; n = 116) compared to those who did not. Patients who did not have surgery lost more weight post-diagnosis (7.6 ± 1.1%; P < 0.0001; n = 355) compared to those who did have surgery. By 12 months post-diagnosis, 83% of the surviving GI cancer patients in this cohort had transitioned into cachexia syndrome. CONCLUSIONS: Significant weight loss in patients with GI cancer cachexia at diagnosis initiates at least 6 months prior to diagnosis, and most patients will transition into cachexia syndrome post-diagnosis, regardless of pre-diagnosis weight change and stage of disease. These findings punctuate the importance of weight surveillance in cancer detection and earlier palliative interventions post-diagnosis in the GI cancer patient population.

Cytokine-Mediated STAT3 Transcription Supports ATGL/CGI-58-Dependent Adipocyte Lipolysis in Cancer Cachexia.

Adipose tissue inflammation is observed in multiple metabolically-altered states including cancer-associated cachexia and obesity. Although cachexia is a syndrome of adipose loss and obesity is a disease of adipose excess, both pathologies demonstrate increases in circulating levels of IL-6 family cytokines, ß-adrenergic signaling, and adipocyte lipolysis. While ß-adrenergic-stimulated adipocyte lipolysis is well described, there is limited mechanistic insight into how cancer cachexia-associated inflammatory cytokines contribute to adipocyte lipolysis under pathologic conditions. Here, we set out to compare adipocyte lipolysis signaling by cancer cachexia-associated IL-6 family cytokines (IL-6 and LIF) to that of the ß-adrenergic agonist isoproterenol. Unlike isoproterenol, the IL-6 family of cytokines required JAK/STAT3-dependent transcriptional changes to induce adipocyte lipolysis. Furthermore, cachexia-associated cytokines that used STAT3 to induce lipolysis were primarily dependent on the lipase ATGL and its cofactor CGI-58 rather than lipases HSL and MAGL. Finally, administration of JAK but not ß-adrenergic inhibitors suppressed adipose STAT3 phosphorylation and associated adipose wasting in a murine model of cancer cachexia characterized by increased systemic IL-6 family cytokine levels. Combined, our results demonstrate how the IL-6 family of cytokines diverge from ß-adrenergic signals by employing JAK/STAT3-driven transcriptional changes to promote adipocyte ATGL/CGI-58-dependent lipolysis contributing to adipose wasting in cancer cachexia.

Primary Tumor Fluorine-18 Fluorodeoxydglucose (18F-FDG) Is Associated With Cancer-Associated Weight Loss in Non-Small Cell Lung Cancer (NSCLC) and Portends Worse Survival.

Aim: To investigate the diagnostic potential of and associations between tumor 18F-FDG uptake on PET imaging and cancer-associated weight loss. Methods: 774 non-small cell lung cancer (NSCLC) patients with pre-treatment PET evaluated between 2006 and 2014 were identified. Using the international validated definition of cachexia, the presence of clinically significant pretreatment cancer-associated weight loss (WL) was retrospectively determined. Maximum Standardized Uptake Value (SUVMax) of 18F-FDG was recorded and dichotomized based on 3 experimental cutpoints for survival analyses. Each SUVMax cutpoint prioritized either survival differences, total cohort comparison sample sizes, or sample size by stage. Patient outcomes and associations between SUVMax and cancer-associated weight loss were assessed by multivariate, categorical, and survival analyses. Results: Patients were found to have an increased likelihood of having WL at diagnosis associated with increasing primary tumor SUVMax after controlling for potentially confounding patient and tumor characteristics on multivariate logistic regression (OR 1.038; 95% CI: 1.012, 1.064; P=0.0037). After stratifying the cohort by WL and dichotomized SUVMax, both factors were found to be relevant in predicting survival outcomes when the alternative variable was constant. Of note, the most striking survival differences contributed by WL status occurred in high SUVMax groups, where the presence of WL predicted a median survival time detriment of up to 10 months, significant regardless of cutpoint determination method applied to categorize high SUVMax patients. SUVMax classification was found to be most consistently relevant in both WL and no WL groups. Conclusions: The significant positive association between significant pretreatment cancer-associated weight loss and primary tumor SUVMax underscores increased glucose uptake as a component of catabolic tumor phenotypes. This substantiates 18F-FDG PET analysis as a prospective tool for assessment of cancer-associated weight loss and corresponding survival outcomes. Furthermore, the survival differences observed between WL groups across multiple SUVMax classifications supports the importance of weight loss monitoring in oncologic workups. Weight loss in the setting of NSCLCs with higher metabolic activity as determined by 18F-FDG PET signal should encourage more aggressive and earlier palliative care interventions.

Associations of Prior Chronic Use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and Glucocorticoids With Cachexia Incidence and Survival.

Background: Cachexia is an inflammatory and metabolic syndrome of unintentional weight loss through depletion of muscle and adipose tissue. There is limited knowledge of how chronic use of non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids affect cachexia development. The purpose of this study was to investigate associations between prior long-term use of NSAIDs or glucocorticoids with cachexia incidence and post-diagnosis weight loss progression in a retrospective cancer patient cohort. Methods: Of 3,802 lung or gastrointestinal cancer patient records, 3,180 comprised our final cohort. Patient demographic information, tumor qualities, medication histories, and comorbidities were assessed. Cachexia was defined as having developed prior to oncologic treatment. Statistical evaluations included categorical, multivariate logistic regression, and log-rank survival analyses. Development of substantial post-diagnosis weight loss was calculated and interpreted for patients without cachexia at diagnosis. Results: Chronic prior use of any NSAID or glucocorticoid medication was associated with approximate absolute and relative reductions in cachexia incidence at diagnosis of 10 and 25 percent (P<0.0001). In multivariate analyses, NSAID medications demonstrated a 23 percent reduction in cachexia incidence likelihood (OR=0.770; 95% CI=0.594, 0.998; P=0.0481). Patients without cachexia at diagnosis were significantly more likely to develop substantial post-diagnosis weight loss from pre-diagnosis use groups of glucocorticoids (OR= 1.452; 95% CI=1.065, 1.979; P=0.0183) or NSAIDs (OR=1.411; 95% CI=1.082, 1.840; P=0.011). Conclusions: Our findings suggest a protective effect of prior anti-inflammatory medications, primarily NSAIDs, against manifestations of the cachexia phenotype at cancer diagnosis. These observations support further exploration of potential therapeutic benefits from anti-inflammatory medications early in cancer management.

Cachexia is Prevalent in Patients With Hepatocellular Carcinoma and Associated With Worse Prognosis.

BACKGROUND & AIMS: Cancer cachexia is a wasting syndrome associated with functional impairment and reduced survival that impacts up to 50% of patients with gastrointestinal cancers. However, data are limited on the prevalence and clinical significance of cachexia in patients with hepatocellular carcinoma (HCC). METHODS: We performed a retrospective cohort study of patients diagnosed with HCC at 2 United States health systems between 2008 and 2018. Patient weights were recorded 6 months prior to and at time of HCC diagnosis. Cachexia was defined as >5% weight loss (or >2% weight loss if body mass index <20 kg/m2), and precachexia was defined as 2% to 5% weight loss. We used multivariable logistic regression models to identify correlates of cachexia and multivariable Cox proportional hazard models to identify factors associated with overall survival. RESULTS: Of 604 patients with HCC, 201 (33.3%) had precachexia and 143 (23.7%) had cachexia at diagnosis, including 19.0%, 23.5%, 34.7%, and 34.0% of patients with Barcelona Clinic Liver Cancer stages 0/A, B, C, and D, respectively. Patients with cachexia were less likely to receive HCC treatment (odds ratio, 0.38; 95% confidence interval, 0.21-0.71) and had worse survival than those with precachexia or stable weight (11.3 vs 20.4 vs 23.5 months, respectively; P < .001). Cachexia remained independently associated with worse survival (hazard ratio, 1.43; 95% confidence interval, 1.11-1.84) after adjusting for age, sex, race, ethnicity, Child Pugh class, alpha-fetoprotein, Barcelona Clinic Liver Cancer stage, and HCC treatment. CONCLUSIONS: Nearly 1 in 4 patients with HCC present with cachexia, including many with compensated cirrhosis or early stage tumors. The presence of cancer-associated weight loss appears to be an early and independent predictor of worse outcomes in patients with HCC.

LIFR-α-dependent adipocyte signaling in obesity limits adipose expansion contributing to fatty liver disease.

The role of chronic adipose inflammation in diet-induced obesity (DIO) and its sequelae including fatty liver disease remains unclear. Leukemia inhibitory factor (LIF) induces JAK-dependent adipocyte lipolysis and altered adipo/cytokine expression, suppressing in vivo adipose expansion in normal and obese mouse models. To characterize LIF receptor (LIFR-α)-dependent cytokine signaling in DIO, we created an adipocyte-specific LIFR knockout mouse model (Adipoq-Cre;LIFR fl/fl ). Differentiated adipocytes derived from this model blocked LIF-induced triacylglycerol lipolysis. Adipoq-Cre;LIFR fl/fl mice on a high-fat diet (HFD) displayed reduced adipose STAT3 activation, 50% expansion in adipose, 20% body weight increase, and a 75% reduction in total hepatic triacylglycerides compared with controls. To demonstrate that LIFR-α signals adipocytes through STAT3, we also created an Adipoq-Cre;STAT3 fl/fl model that showed similar findings when fed a HFD as Adipoq-Cre;LIFR fl/fl mice. These findings establish the importance of obesity-associated LIFR-α/JAK/STAT3 inflammatory signaling in adipocytes, blocking further adipose expansion in DIO contributing to ectopic liver triacylglyceride accumulation.

The influence of tumour fluorodeoxyglucose avidity and cachexia development on patient survival in oesophageal or gastroesophageal junction cancer.

Background and Aims: Cancer cachexia is manifested by loss in muscle, adipose, weight, and appetite. PET 18F-FDG uptake identifies tumor metabolic and inflammatory changes, potentially associated with cachexia development. We examined if primary gastroesophageal tumor 18F-FDG uptake correlates with cachexia development and survival in cancer patients. Methods: One hundred twenty-six esophageal (n=87) and gastroesophageal junction (n=39) cancer patients, with a median age at diagnosis of 63 years (IQR 54-71), evaluated between 2006-2014 with pre-treatment PET imaging and cachexia determination at diagnosis were included in the study cohort (22.1% female; 6.7%, 24.4%, 50.4%, and 18.5% with tumor stage I, II, III, and IV respectively). Maximum primary tumor standardized uptake values (SUVMax) were obtained and dichotomized based off the calculated cut-point SUVMax of 8.5 (P=.0018). Associations between survival, cachexia development and primary tumor 18F-FDG uptake were evaluated using univariate and multivariate analyses. Results: Cancer-associated weight loss (cachexia) and primary tumor SUVMax at or above the statistically determined cut-point of 8.5 were present in 54% and 57% of patients, respectively. Primary tumor SUVMax above the cut-point was significantly associated with pre-treatment cancer-associated weight loss (P=.0033) and, in multivariate analysis, correlated with a 2.3-fold increased risk of death (95% CI 1.4, 3.7; P=.0010). When divided into cohorts defined by their combined cachexia and high versus low SUVMax tumor status, positive cachexia status or/and high SUVMax tumors were associated with similar significant decrements in survival. Conclusion: A positive association was present between cancer-associated weight loss and SUVMax of the primary tumor, suggesting greater glycolytic metabolism in gastroesophageal tumors that induce cachexia. This interpretation of routinely administered PET scans could lead to earlier categorization of patients with cachexia-inducing tumors. Both cachexia and high SUVMax status were independently associated with worsened survival outcomes, further supporting their prognostic relevance in patients with gastroesophageal cancer.

JAK Inhibitors Suppress Cancer Cachexia-Associated Anorexia and Adipose Wasting in Mice.

BACKGROUND: Cachexia, a syndrome of muscle atrophy, adipose loss, and anorexia, is associated with reduced survival in cancer patients. The colon adenocarcinoma C26c20 cell line secretes the cytokine leukemia inhibitory factor (LIF) which induces cachexia. We characterized how LIF promotes cachexia-associated weight loss and anorexia in mice through JAK-dependent changes in adipose and hypothalamic tissues. METHODS: Cachexia was induced in vivo with the heterotopic allotransplanted administration of C26c20 colon adenocarcinoma cells or the intraperitoneal administration of recombinant LIF in the absence or presence of JAK inhibitors. Blood, adipose, and hypothalamic tissues were collected and processed for cyto/adipokine ELISAs, immunoblot analysis, and quantitative RT-PCR. Cachexia-associated lipolysis was induced in vitro by stimulating differentiated adipocytes with recombinant LIF or IL-6 in the absence or presence of lipase or JAK inhibitors. These adipocytes were processed for glycerol release into the media, immunoblot analysis, and RT-PCR. RESULTS: Tumor-secreted LIF induced changes in adipose tissue expression and serum levels of IL-6 and leptin in a JAK-dependent manner influencing cachexia-associated adipose wasting and anorexia. We identified two JAK inhibitors that block IL-6 family-mediated adipocyte lipolysis and IL-6 induction using an in vitro cachexia lipolysis assay. JAK inhibitors administered to the in vivo C26c20 cancer cachexia mouse models led to 1) a decrease in STAT3 phosphorylation in hypothalamic and adipose tissues, 2) a reverse in the cachexia serum cyto/adipokine signature, 3) a delay in cancer cachexia-associated anorexia and adipose loss, and 4) an improvement in overall survival. CONCLUSIONS: JAK inhibitors suppress LIF-associated adipose loss and anorexia in both in vitro and in vivo models of cancer cachexia.

Cholesterol Stabilizes TAZ in Hepatocytes to Promote Experimental Non-alcoholic Steatohepatitis.

Incomplete understanding of how hepatosteatosis transitions to fibrotic non-alcoholic steatohepatitis (NASH) has limited therapeutic options. Two molecules that are elevated in hepatocytes in human NASH liver are cholesterol, whose mechanistic link to NASH remains incompletely understood, and TAZ, a transcriptional regulator that promotes fibrosis but whose mechanism of increase in NASH is unknown. We now show that increased hepatocyte cholesterol upregulates TAZ and promotes fibrotic NASH. ASTER-B/C-mediated internalization of plasma membrane cholesterol activates soluble adenylyl cyclase (sAC; ADCY10), triggering a calcium-RhoA-mediated pathway that suppresses ß-TrCP/proteasome-mediated TAZ degradation. In mice fed with a cholesterol-rich NASH-inducing diet, hepatocyte-specific silencing of ASTER-B/C, sAC, or RhoA decreased TAZ and ameliorated fibrotic NASH. The cholesterol-TAZ pathway is present in primary human hepatocytes, and associations among liver cholesterol, TAZ, and RhoA in human NASH liver are consistent with the pathway. Thus, hepatocyte cholesterol contributes to fibrotic NASH by increasing TAZ, suggesting new targets for therapeutic intervention.

Ostreolysin A and anthrolysin O use different mechanisms to control movement of cholesterol from the plasma membrane to the endoplasmic reticulum.

Recent studies using two cholesterol-binding bacterial toxin proteins, perfringolysin O (PFO) and domain 4 of anthrolysin O (ALOD4), have shown that cholesterol in the plasma membranes (PMs) of animal cells resides in three distinct pools. The first pool comprises mobile cholesterol, accessible to both PFO and ALOD4, that is rapidly transported to the endoplasmic reticulum (ER) to signal cholesterol excess and maintain cholesterol homeostasis. The second is a sphingomyelin (SM)-sequestered pool inaccessible to PFO and ALOD4 but that becomes accessible by treatment with SM-degrading sphingomyelinase (SMase). The third is an essential pool also inaccessible to PFO and ALOD4 that cannot be liberated by SMase treatment. The accessible cholesterol pool can be trapped on PMs of live cells by nonlytic ALOD4, blocking its transport to the ER. However, studies of the two other pools have been hampered by a lack of available tools. Here, we used ostreolysin A (OlyA), which specifically binds SM/cholesterol complexes in membranes, to study the SM-sequestered cholesterol pool. Binding of nonlytic OlyA to SM/cholesterol complexes in PMs of live cells depleted the accessible PM cholesterol pool detectable by ALOD4. Consequently, transport of accessible cholesterol from PM to ER ceased, thereby activating SREBP transcription factors and increasing cholesterol synthesis. Thus, OlyA and ALOD4 both control movement of PM cholesterol, but through different lipid-binding mechanisms. We also found that PM-bound OlyA was rapidly internalized into cells, whereas PM-bound ALOD4 remained on the cell surface. Our findings establish OlyA and ALOD4 as complementary tools to investigate cellular cholesterol transport.

Monitoring and Modulating Intracellular Cholesterol Trafficking Using ALOD4, a Cholesterol-Binding Protein.

Mammalian cells carefully control their cholesterol levels by employing multiple feedback mechanisms to regulate synthesis of cholesterol and uptake of cholesterol from circulating lipoproteins. Most of a cell's cholesterol (~80% of total) is in the plasma membrane (PM), but the protein machinery that regulates cellular cholesterol resides in the endoplasmic reticulum (ER) membrane, which contains a very small fraction (~1% of total) of a cell's cholesterol. How does the ER communicate with PM to monitor cholesterol levels in that membrane? Here, we describe a tool, ALOD4, that helps us answer this question. ALOD4 traps cholesterol at the PM, leading to depletion of ER cholesterol without altering total cell cholesterol. The effects of ALOD4 are reversible. This tool has been used to show that the ER is able to continuously sample cholesterol from PM, providing ER with information about levels of PM cholesterol.

Cachexia-associated adipose loss induced by tumor-secreted leukemia inhibitory factor is counterbalanced by decreased leptin.

Cachexia syndrome consists of adipose and muscle loss, often despite normal food intake. We hypothesized that cachexia-associated adipose wasting is driven in part by tumor humoral factors that induce adipocyte lipolysis. We developed an assay to purify secreted factors from a cachexia-inducing colon cancer line that increases lipolysis in adipocytes and identified leukemia inhibitory factor (LIF) by mass spectrometry. Recombinant LIF induced lipolysis in vitro. Peripheral LIF administered to mice caused >50% loss of adipose tissue and >10% reduction in body weight despite only transient hypophagia due to decreasing leptin. LIF-injected mice lacking leptin (ob/ob) resulted in persistent hypophagia and loss of adipose tissue and body weight. LIF's peripheral role of initiating lipolysis in adipose loss was confirmed in pair-fed ob/ob mouse studies. Our studies demonstrate that (a) LIF is a tumor-secreted factor that promotes cachexia-like adipose loss when administered peripherally, (b) LIF directly induces adipocyte lipolysis, (c) LIF has the ability to sustain adipose and body weight loss through an equal combination of peripheral and central contributions, and (d) LIF's central effect is counterbalanced by decreased leptin signaling, providing insight into cachexia's wasting, despite normophagia.

Impact of Socioeconomic Status on Pretreatment Weight Loss and Survival in Non-Small-Cell Lung Cancer.

PURPOSE: Socioeconomic status (SES) influences health care outcomes, but the influence of primary payer on cancer-associated wasting is unknown. We hypothesized that primary payer as an indicator of SES would influence pretreatment cancer-associated weight loss and treatment outcomes. MATERIALS AND METHODS: Retrospective review of medical records identified 1,366 patients with non-small-cell lung cancer (NSCLC) consecutively treated at a tertiary care health system between January 1, 2006 and December 31, 2013. Insurance status was obtained from an institutional tumor registry. Cancer-associated weight loss was based on the validated international consensus definition of cachexia. Multivariable regression analyses were used to identify prognostic factors of pretreatment cancer-associated weight loss and survival. RESULTS: The cohort included a representative group of patients with a median age at diagnosis of 64 years, 47% females, and 33% patients of nonwhite race. Pretreatment cancer-associated weight loss was present at the time of NSCLC diagnosis in 17%, 14%, 32%, and 38% of patients with stage I, II, III, and IV disease, respectively. Pretreatment cancer-associated weight loss was associated with increasing age at diagnosis, black race, single marital status, tobacco use, and disease stage. Compared with private insurance, Medicaid insurance (odds ratio, 2.17; 95% CI, 1.42 to 3.30) and lack of insurance (odds ratio, 2.32; 95% CI, 1.50 to 3.58) were associated with pretreatment cancer-associated weight loss. Among cachectic patients, comorbidity, histology, tumor grade, and disease stage were prognostic of survival on multivariable analysis; however, primary payer was not. CONCLUSION: Pretreatment cancer-associated weight loss is common in patients with NSCLC, and its presence is significantly associated with lower SES. However, among patients with pretreatment cancer-associated weight loss, SES was not predictive of survival. Early use of cancer cachexia-directed therapies may improve outcomes, and further study on the biologic mechanisms of cancer cachexia will provide novel therapeutic avenues.

Prevalence and Survival Impact of Pretreatment Cancer-Associated Weight Loss: A Tool for Guiding Early Palliative Care.

PURPOSE: Cancer-associated weight loss is associated with poor prognosis in advanced malignancy; however, its pretreatment prevalence and survival impact are inadequately described in large cohorts. Such data, stratified by tumor type and stage, may facilitate the optimal and timely allocation of complementary care, leading to improvements in patient survival and quality of life. METHODS: We performed a retrospective cohort study of 3,180 consecutively treated adult patients with lung or GI (including colorectal, liver, and pancreatic) cancer. Pretreatment cancer-associated weight loss was based on the international consensus definition of cachexia. Prevalence and survival impact of pretreatment cancer-associated weight loss were evaluated using the Kaplan-Meier method and compared using log-rank test. RESULTS: Cancer-associated weight loss was observed at the time of cancer diagnosis in 34.1% of patients. Pretreatment weight loss was documented in 17.6%, 25.8%, 36.6%, and 43.3% of stage I, II, III, and IV cancers, respectively. Wasting was common regardless of tumor type, with prevalence at diagnosis ranging from 27.3% in patients with colorectal cancer to 53.4% in patients with gastroesophageal cancer. Pretreatment weight loss was associated with reduced overall survival after adjusting for stage, size, grade, comorbidity, age, sex, and tobacco history (hazard ratio, 1.26; 95% CI, 1.13 to 1.39). CONCLUSION: Pretreatment cancer-associated weight loss is common, even in early-stage disease, and is independently associated with reduced survival. Minimal weight loss represents a clinically distinct entity with an associated overall survival intermediate to that of no weight loss and overt wasting. Early diagnosis and treatment of cancer-associated wasting offers a novel therapeutic avenue for reducing cancer mortality.

Continuous transport of a small fraction of plasma membrane cholesterol to endoplasmic reticulum regulates total cellular cholesterol.

Cells employ regulated transport mechanisms to ensure that their plasma membranes (PMs) are optimally supplied with cholesterol derived from uptake of low-density lipoproteins (LDL) and synthesis. To date, all inhibitors of cholesterol transport block steps in lysosomes, limiting our understanding of post-lysosomal transport steps. Here, we establish the cholesterol-binding domain 4 of anthrolysin O (ALOD4) as a reversible inhibitor of cholesterol transport from PM to endoplasmic reticulum (ER). Using ALOD4, we: (1) deplete ER cholesterol without altering PM or overall cellular cholesterol levels; (2) demonstrate that LDL-derived cholesterol travels from lysosomes first to PM to meet cholesterol needs, and subsequently from PM to regulatory domains of ER to suppress activation of SREBPs, halting cholesterol uptake and synthesis; and (3) determine that continuous PM-to-ER cholesterol transport allows ER to constantly monitor PM cholesterol levels, and respond rapidly to small declines in cellular cholesterol by activating SREBPs, increasing cholesterol uptake and synthesis.