Quantitative Determination of Cholesterol Hydroxylase Specificities by GC-MS/MS in Living Mammalian Cells.

Cholesterol is oxygenated by a variety of cholesterol hydroxylases; oxysterols play diverse important roles in physiological and pathophysiological conditions by regulating several transcription factors and cell-surface receptors. Each oxysterol has distinct and overlapping functions. The expression of cholesterol hydroxylases is highly regulated, but their physiological and pathophysiological roles are not fully understood. Although the activity of cholesterol hydroxylases has been characterized biochemically using radiolabeled cholesterol as the substrate, their specificities remain to be comprehensively determined quantitatively. To better understand their roles, a highly sensitive method to measure the amount of various oxysterols synthesized by cholesterol hydroxylases in living mammalian cells is required. Our method described here, with gas chromatography coupled with tandem mass spectrometry (GC-MS/MS), can quantitatively determine a series of oxysterols endogenously synthesized by forced expression of one of the four major cholesterol hydroxylases-CH25H, CYP7A1, CYP27A1, and CYP46A1-or induction of CH25H expression by a physiological stimulus. This protocol can also simultaneously measure the amount of intermediate sterols, which serve as markers for cellular cholesterol synthesis activity. Key features • Allows measuring the amount of a variety of oxysterols synthesized endogenously by cholesterol hydroxylases using GC-MS/MS. • Comprehensive and quantitative analysis of cholesterol hydroxylase specificities in living mammalian cells. • Simultaneous quantification of intermediate sterols to assess cholesterol synthesis activity.

Establishment of a cell culture platform for human liver organoids and its application for lipid metabolism research.

Human liver organoids (HLOs) are reliable tools to represent physiological human liver biology. However, their use is limited especially in basic sciences. One of the reasons for this would be the insufficient systematic methodology to handle HLOs, including culture system, functional assessment, and gene transduction. Here, we generated and characterized mouse L cells stably and simultaneously overexpressing R-spondin1, hepatocyte growth factor, fibroblast growth factor (FGF) 7, and FGF10 via lentiviral transduction. The conditioned medium of the cells contributed to HLO growth as a replacement of commercially available recombinant proteins, which leads to a significant reduction of their culture cost. Proliferative and maturation phases of the cells were controlled by switching the medium to facilitate the evaluation of hepatocyte function, including insulin responsiveness and intracellular lipid accumulation. Gene expression analysis revealed that HLOs highly expressed genes involved in lipid metabolism. Importantly, HLOs secreted physiologically matured very low-density lipoprotein, which is rarely observed in mice and in established cell lines. Efficient gene transduction into HLOs was achieved via a transient 2-dimensional culture during viral infection. This study provides an invaluable platform for utilizing HLOs in various research fields, such as molecular biology, pharmacology, toxicology, and regenerative medicine.

Prognostic significance of Ishii's sarcopenia screening score for patients undergoing curative surgery for obstructive colorectal cancer after intraluminal decompression.

PURPOSE: Sarcopenia influences the short- and long-term outcomes of various medical conditions including malignancy. Ishii's screening test estimates the probability of sarcopenia based on a score calculated by three simple variables: age, grip strength, and calf circumference. We investigated the clinical significance of Ishii's score for patients with non-metastatic obstructive colorectal cancer (OCRC) who underwent curative surgery after intraluminal decompression. METHODS: Ishii's score was calculated in 79 patients with OCRC. Muscle volume loss and decreased muscle quality were evaluated by computed tomography (CT) images as skeletal muscle index (SMI) and intramuscular adipose tissue content (IMAC), respectively. RESULTS: There were 46 men and 33 women, with a median age of 70 years old. The cutoff value for Ishii's score was 155.1 and 15 patients were in the high-score group. The high-score group was significantly associated with worse time to recurrence (TTR) and overall survival (OS), and a high Ishii's score was an independent negative prognostic factor for TTR (hazard ratio = 2.93, P = 0.015). A high Ishii's score was significantly associated with a low SMI value but not with the IMAC value. CONCLUSION: A high Ishii's score was independently associated with poorer TTR in patients with non-metastatic OCRC.

Rhomboid protease RHBDL4/RHBDD1 cleaves SREBP-1c at endoplasmic reticulum monitoring and regulating fatty acids.

The endoplasmic reticulum (ER)-embedded transcription factors, sterol regulatory element-binding proteins (SREBPs), master regulators of lipid biosynthesis, are transported to the Golgi for proteolytic activation to tune cellular cholesterol levels and regulate lipogenesis. However, mechanisms by which the cell responds to the levels of saturated or unsaturated fatty acids remain underexplored. Here, we show that RHBDL4/RHBDD1, a rhomboid family protease, directly cleaves SREBP-1c at the ER. The p97/VCP, AAA-ATPase complex then acts as an auxiliary segregase to extract the remaining ER-embedded fragment of SREBP-1c. Importantly, the enzymatic activity of RHBDL4 is enhanced by saturated fatty acids (SFAs) but inhibited by polyunsaturated fatty acids (PUFAs). Genetic deletion of RHBDL4 in mice fed on a Western diet enriched in SFAs and cholesterol prevented SREBP-1c from inducing genes for lipogenesis, particularly for synthesis and incorporation of PUFAs, and secretion of lipoproteins. The RHBDL4-SREBP-1c pathway reveals a regulatory system for monitoring fatty acid composition and maintaining cellular lipid homeostasis.

Low Geriatric Nutritional Risk Index (GNRI) Predicts Poorer Survival in Patients with Obstructive Colorectal Cancer Who Had a Self-Expandable Metallic Stent (SEMS) Inserted as a Bridge to Curative Surgery.

Objectives: The geriatric nutritional risk index (GNRI) is a nutrition-related risk index calculated easily from serum albumin and the ratio of body weight to ideal body weight. We investigated the prognostic values of the GNRI in elderly patients with obstructive colorectal cancer (OCRC) who had a self-expandable metallic stent inserted as a bridge to curative surgery. Methods: We retrospectively evaluated 61 patients aged ≥65 years with pathological stage I to III OCRC. Associations of preoperative GNRI and pre-stenting GNRI (ps-GNRI) with short- and long-term outcomes were examined. Results: Multivariate analyses revealed GNRI of <85.3 and ps-GNRI of <92.9 were independently associated with worse cancer-specific survival (CSS; P = 0.016, and P = 0.041, respectively), and overall survival (OS; P = 0.020, and P = 0.024, respectively). A ps-GNRI of <92.9 was correlated with poorer relapse-free survival (RFS) only in the univariate analysis (P = 0.034). For the OCRC cohort without age restriction (n = 86), GNRI of <85.3 and ps-GNRI of <92.9 were independently associated with worse CSS (P = 0.021), and OS (P = 0.023), respectively. In univariate analysis, ps-GNRI of <92.9 was significantly correlated with poorer RFS (P = 0.006). Moreover, ps-GNRI of <92.9 was significantly associated with Clavien-Dindo grade of ≥III postoperative complications (P = 0.037), anastomotic leak (P = 0.032), infectious complications (P = 0.002), and longer postoperative hospital stay (17 days vs. 15 days; P = 0.048). Conclusions: In OCRC patients, decreased preoperative and pre-stenting GNRI were significantly correlated with poorer survival, and decreased pre-stenting GNRI was significantly associated with worse short- and long-term outcomes.

Drug cytotoxicity screening using human intestinal organoids propagated with extensive cost-reduction strategies.

Organoids are regarded as physiologically relevant cell models and useful for compound screening for drug development; however, their applications are currently limited because of the high cost of their culture. We previously succeeded in reducing the cost of human intestinal organoid culture using conditioned medium (CM) of L cells co-expressing Wnt3a, R-spondin1, and Noggin. Here, we further reduced the cost by replacing recombinant hepatocyte growth factor with CM. Moreover, we showed that embedding organoids in collagen gel, a more inexpensive matrix than Matrigel, maintains organoid proliferation and marker gene expression similarly when using Matrigel. The combination of these replacements also enabled the organoid-oriented monolayer cell culture. Furthermore, screening thousands of compounds using organoids expanded with the refined method identified several compounds with more selective cytotoxicity against organoid-derived cells than Caco-2 cells. The mechanism of action of one of these compounds, YC-1, was further elucidated. We showed that YC-1 induces apoptosis through the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway, the mechanism of which was distinct from cell death caused by other hit compounds. Our cost-cutting methodology enables large-scale intestinal organoid culture and subsequent compound screening, which could expand the application of intestinal organoids in various research fields.

Identification of α-ionone, nootkatone, and their derivatives as TGR5 agonists.

TGR5 is a G-protein-coupled receptor that is activated by bile acids. The activation of TGR5 in brown adipose tissue (BAT) increases energy expenditure by increasing the expression level of thermogenesis-related genes, such as peroxisome proliferator-activated receptor-gamma coactivator 1-alpha, uncoupling protein 1, and type II iodothyronine deiodinase. Therefore, TGR5 is a potential drug target in treating obesity and associated metabolic disorders. In this study, we identified the aroma compounds α-ionone and nootkatone as well as their derivatives as TGR5 agonists by using the luciferase reporter assay system. These compounds had little effect on the activity of the farnesoid X receptor, a nuclear receptor activated by bile acids. Mice fed 0.2% α-ionone containing high-fat diet (HFD) increased the thermogenesis-related gene expression level in BAT and suppressed weight gain compared with mice fed a normal HFD. These findings indicate that aromatic compounds with TGR5 agonist activity are promising chemicals to prevent obesity.

Hydroxylation site-specific and production-dependent effects of endogenous oxysterols on cholesterol homeostasis: Implications for SREBP-2 and LXR.

The cholesterol metabolites, oxysterols, play central roles in cholesterol feedback control. They modulate the activity of two master transcription factors that control cholesterol homeostatic responses, sterol regulatory element-binding protein-2 (SREBP-2) and liver X receptor (LXR). Although the role of exogenous oxysterols in regulating these transcription factors has been well established, whether endogenously synthesized oxysterols similarly control both SREBP-2 and LXR remains poorly explored. Here, we carefully validate the role of oxysterols enzymatically synthesized within cells in cholesterol homeostatic responses. We first show that SREBP-2 responds more sensitively to exogenous oxysterols than LXR in Chinese hamster ovary cells and rat primary hepatocytes. We then show that 25-hydroxycholesterol (25-HC), 27-hydroxycholesterol, and 24S-hydroxycholesterol endogenously synthesized by CH25H, CYP27A1, and CYP46A1, respectively, suppress SREBP-2 activity at different degrees by stabilizing Insig (insulin-induced gene) proteins, whereas 7α-hydroxycholesterol has little impact on SREBP-2. These results demonstrate the role of site-specific hydroxylation of endogenous oxysterols. In contrast, the expression of CH25H, CYP46A1, CYP27A1, or CYP7A1 fails to induce LXR target gene expression. We also show the 25-HC production-dependent suppression of SREBP-2 using a tetracycline-inducible CH25H expression system. To induce 25-HC production physiologically, murine macrophages are stimulated with a Toll-like receptor 4 ligand, and its effect on SREBP-2 and LXR is examined. The results also suggest that de novo synthesis of 25-HC preferentially regulates SREBP-2 activity. Finally, we quantitatively determine the specificity of the four cholesterol hydroxylases in living cells. Based on our current findings, we conclude that endogenous side-chain oxysterols primarily regulate the activity of SREBP-2, not LXR.

A decreased preoperative platelet-to-lymphocyte ratio, systemic immune-inflammation index, and pan-immune-inflammation value are associated with the poorer survival of patients with a stent inserted as a bridge to curative surgery for obstructive colorectal cancer.

PURPOSE: Inflammation is one of the hallmarks of cancer, and inflammation-based markers that are calculated easily from laboratory results have shown predictive abilities. We investigated the prognostic values of the preoperative platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and pan-immune-inflammation value (PIV) in patients with non-metastatic obstructive colorectal cancer (OCRC) and a self-expandable metallic stent inserted as a bridge to curative surgery. METHODS: The subjects of this retrospective study were 86 patients with pathological stage I to III OCRC. We examined the associations of these biomarkers with short- and long-term outcomes. RESULTS: Multivariate analyses revealed that a preoperative PLR < 149, SII < 597, and PIV < 209 were independently associated with poorer relapse-free survival (RFS) (P = 0.007, P < 0.001, and P = 0.002, respectively) and that a PIV < 209 was independently associated with poorer cancer-specific survival (P = 0.030). A platelet count < 240 was significantly associated with worse RFS, whereas the lymphocyte count was not. Pre-stenting PLR < 221 was an independent poor prognostic factor for RFS (P = 0.045). CONCLUSION: This study showed that decreased preoperative PLR, SII, PIV, and pre-stenting PLR were associated with poorer RFS, contrary to the findings of most previous studies. Our results suggest that platelets and obstruction contributed primarily to the opposite relationships, which might provide new insight into the possible pathophysiology of platelet-tumor interactions generated in the OCRC environment.

Pathophysiological levels of GDF11 activate Smad2/Smad3 signaling and induce muscle atrophy in human iPSC-derived myocytes.

Skeletal muscle mass is negatively regulated by several TGF-ß superfamily members. Myostatin (MSTN) is the most prominent negative regulator of muscle mass. Recent studies show that in addition to MSTN, GDF11, which shares a high sequence identity with MSTN, induces muscle atrophy in vitro and in vivo at supraphysiological levels, whereas controversy regarding its roles exists. Furthermore, higher circulating GDF11 levels associate with frailty in humans. On the other hand, little is known about the effect of pathophysiological levels of GDF11 on muscle atrophy. Here we seek to determine whether pathophysiological levels of GDF11 are sufficient to activate Smad2/Smad3 signaling and induce muscle atrophy using human iPSC-derived myocytes (hiPSC myocytes). We first show that incubating hiPSC myocytes with pathophysiological concentrations of GDF11 significantly reduces myocyte diameters. We next demonstrate that pathophysiological levels of GDF11 are sufficient to activate Smad2/3 signaling. Finally, we show that pathophysiological levels of GDF11 are capable of inducing the expression of Atrogin-1, an atrophy-promoting E3 ubiquitin ligase and that FOXO1 blockage reverses the GDF11-induced Atrogin-1 expression and atrophic phenotype. Collectively, our results suggest that GDF11 induces skeletal muscle atrophy at the pathophysiological levels through the GDF11-FOXO1 axis.

Lactic acid bacteria-derived γ-linolenic acid metabolites are PPARδ ligands that reduce lipid accumulation in human intestinal organoids.

Gut microbiota regulate physiological functions in various hosts, such as energy metabolism and immunity. Lactic acid bacteria, including Lactobacillus plantarum, have a specific polyunsaturated fatty acid saturation metabolism that generates multiple fatty acid species, such as hydroxy fatty acids, oxo fatty acids, conjugated fatty acids, and trans-fatty acids. How these bacterial metabolites impact host physiology is not fully understood. Here, we investigated the ligand activity of lactic acid bacteria-produced fatty acids in relation to nuclear hormone receptors expressed in the small intestine. Our reporter assays revealed two bacterial metabolites of γ-linolenic acid (GLA), 13-hydroxy-cis-6,cis-9-octadecadienoic acid (γHYD), and 13-oxo-cis-6,cis-9-octadecadienoic acid (γKetoD) activated peroxisome proliferator-activated receptor delta (PPARδ) more potently than GLA. We demonstrate that both γHYD and γKetoD bound directly to the ligand-binding domain of human PPARδ. A docking simulation indicated that four polar residues (T289, H323, H449, and Y473) of PPARδ donate hydrogen bonds to these fatty acids. Interestingly, T289 does not donate a hydrogen bond to GLA, suggesting that bacterial modification of GLA introducing hydroxy and oxo group determines ligand selectivity. In human intestinal organoids, we determined γHYD and γKetoD increased the expression of PPARδ target genes, enhanced fatty acid ß-oxidation, and reduced intracellular triglyceride accumulation. These findings suggest that γHYD and γKetoD, which gut lactic acid bacteria could generate, are naturally occurring PPARδ ligands in the intestinal tract and may improve lipid metabolism in the human intestine.

Nobiletin enhances plasma Interleukin-6 and C-X-C motif chemokine ligand 1 levels that are increased by treadmill running.

Exercise increases the muscular secretion of Interleukin-6 (IL-6), which is partially regulated by ß2-adrenergic receptor signaling. Nobiletin is a polymethoxyflavone (PMF) found in citrus fruits that induces the secretion of IL-6 from C2C12 myotubes, but it remains unclear whether nobiletin promotes IL-6 secretion during exercise. The aim of this study was to clarify the effects of nobiletin on IL-6 secretion during exercise. Nobiletin and epinephrine were found to synergistically increase IL-6 secretion from differentiated C2C12 cells, which was suppressed by the inhibition of adenylyl cyclase (AC) or protein kinase A (PKA). Treadmill running for 60 min increased plasma levels of IL-6, epinephrine, and norepinephrine in rats. Nobiletin (5 mg/kg) orally administered 30 min before running increased plasma IL-6 levels further, although it did not increase plasma epinephrine and norepinephrine. In a similar manner to IL-6, nobiletin and epinephrine synergistically increased the secretion of C-X-C motif chemokine ligand 1 (CXCL-1) from C2C12 cells, or the increase in plasma CXCL-1 was enhanced by nobiletin after treadmill running of rats. Our results suggest that nobiletin promotes IL-6 and CXCL-1 secretion from skeletal muscle by synergistic enhancement of the PKA pathway in ß2-adrenergic receptor signaling.

[An autopsy case report of a patient with frontotemporal dementia with motor neuron disease in totally locked-in state showing hyperosmolar hyperosmotic state].

A 57-year-old man with no family history of amyotrophic lateral sclerosis (ALS) or diabetes was diagnosed with ALS, and placed in long-term care where an artificial respirator with tracheotomy was used. He was fed through a gastric fistula tube. He gradually lost the ability to communicate, and computed tomography revealed advanced atrophy of the frontotemporal lobe. He was abruptly suffered from polyuria 11 years after the onset of ALS, and was diagnosed with hyperosmolar hyperglycemic state (HHS). It recurred six years later with severe ascites and worsening of pleural effusion. He passed away 18 years after the onset of ALS. Pathological examination revealed a reduced numbers of Betz cells in the motor cortex, anterior horn cells in the spinal cord, and hypoglossal neurons. The remaining lower motor neurons and cells in the hippocampal dentate gyrus were positive for phosphorylated TDP-43. These corresponded to Type B on harmonized classification system for frontotemporal lobar degeneration (FTLD)-TDP pathology (Mackenzie, et al. 2011). Furthermore, the lateral, anterior, and anterolateral funiculi of the spinal cord, globus pallidus, thalamus, and brainstem tegmentum showed atrophy. The findings were compatible with ALS pathology in totally locked-in state (TLS). Hyalinized islets of Langerhans were observed scattered throughout the pancreas. The patient's muscles were nearly completely replaced by white, firm fat tissue. We considered that the patient's diabetic conditions contributed to the accumulation of excess fat in internal and external fat tissue as a result of the long-term dependence on enteral nutrition. Moreover, a disturbance in glucose metabolism in skeletal muscles that resulted from severe atrophy could have been another cause.

Organoid-derived intestinal epithelial cells are a suitable model for preclinical toxicology and pharmacokinetic studies.

Intestinal organoids are physiologically relevant tools used for cellular models. However, the suitability of organoids to examine biological functions over existing established cell lines lacks sufficient evidence. Cytochrome P450 3A4 (CYP3A4) induction by pregnane X receptor ligands, glucose uptake via sodium/glucose cotransporter 1, and microsomal triglyceride transfer protein-dependent ApoB-48 secretion, which are critical for human intestinal metabolism, were observed in organoid-derived two-dimensional cells but little in Caco-2 cells. CYP3A4 induction evaluation involved a simplified method of establishing organoids that constitutively expressed a reporter gene. Compound screening identified several anticancer drugs with selective activities toward Caco-2 cells, highlighting their characteristics as cancer cells. Another compound screening revealed a decline in N-(4-hydroxyphenyl)retinamide cytotoxicity upon rifampicin treatment in organoid-derived cells, under CYP3A4-induced conditions. This study shows that organoid-derived intestinal epithelial cells (IECs) possess similar physiological properties as intestinal epithelium and can serve as tools for enhancing the prediction of biological activity in humans.

Sulforaphane suppresses the activity of sterol regulatory element-binding proteins (SREBPs) by promoting SREBP precursor degradation.

Sterol regulatory element-binding proteins (SREBPs) are transcription factors that regulate various genes involved in cholesterol and fatty acid synthesis. In this study, we describe that naturally occurring isothiocyanate sulforaphane (SFaN) impairs fatty acid synthase promoter activity and reduces SREBP target gene (e.g., fatty acid synthase and acetyl-CoA carboxylase 1) expression in human hepatoma Huh-7 cells. SFaN reduced SREBP proteins by promoting the degradation of the SREBP precursor. Amino acids 595-784 of SREBP-1a were essential for SFaN-mediated SREBP-1a degradation. We also found that such SREBP-1 degradation occurs independently of the SREBP cleavage-activating protein and the Keap1-Nrf2 pathway. This study identifies SFaN as an SREBP inhibitor and provides evidence that SFaN could have major potential as a pharmaceutical preparation against hepatic steatosis and obesity.

Prognostic significance of the mean corpuscular volume (MCV) and red cell distribution width (RDW) in obstructive colorectal cancer patients with a stent inserted as a bridge to curative surgery.

PURPOSE: The prognostic significance of the mean corpuscular volume (MCV) and red cell distribution width (RDW) in patients with malignancy have not been intensely investigated and are largely overlooked. We, therefore, investigated the clinical significance of MCV and RDW in non-metastatic obstructive colorectal cancer (OCRC) patients with a self-expandable metallic stent inserted as a bridge to curative surgery. METHODS: Eighty-five pathological stage II and III OCRC patients were retrospectively evaluated. The associations of the preoperative MCV and RDW values with short- and long-term outcomes were examined. RESULTS: There were 50 males and 35 females, and the median age was 71 years old. The median interval between stenting and surgery was 17 days, and the median postoperative hospital stay was 16 days. Fifty-six patients were in the MCV ≥ 87 group, and 47 were in the RDW ≥ 13.8 group. Multivariate analyses revealed the MCV ≥ 87 status to be independently associated with a poor relapse-free survival (hazard ratio [HR] = 4.70, 95% confidence interval [CI] 1.52-14.58, P = 0.007). The RDW ≥ 13.8% was an independent predictor of postoperative infectious complications (HR = 7.28, 95% CI 1.24-42.70, P = 0.028). CONCLUSION: The MCV and RDW are simple but strong predictors of postoperative outcomes in OCRC patients.

Sesamin and Hepatic Metabolites Derived from Sesamin and Episesamin Antagonize Farnesoid X Receptor and Reduce the Expression of Gluconeogenesis-Related Genes.

Sesamin and episesamin are the main lignans found in refined sesame oil and have been reported to exert various health benefits. However, the health benefits of these lignans and their molecular mechanisms have not been fully understood. This study evaluated the effects of sesamin, episesamin, and their metabolites on the nuclear bile acid receptor, farnesoid X receptor (FXR, NR1H4), which regulate gene expression involved in bile acid metabolism and gluconeogenesis. By using two different cell-based luciferase reporter assay systems, we found that sesamin, sesamin metabolites, and some episesamin metabolites inhibited FXR activation driven by a bile acid and a synthesized agonist, and it is suggested that these compounds exert their antagonist activity by competing with the FXR agonists on the ligand-binding domain. Sesamin and its major metabolite SC-1 suppressed the expression of several gluconeogenesis-related genes governed by FXR in HepG2 cells but did not affect the expression level of CYP7A1, the rate-limiting enzyme for bile acid synthesis. Dietary sesamin supplementation (AIN-93G supplemented with 0.5% sesamin) led to the decreased hepatic expression of several gluconeogenesis-related genes and reduced blood glucose levels in mice, without adverse effects on bile acid metabolism. These results shed light on the health benefits of taking sesamin and episesamin.

Endocrine Fibroblast Growth Factors in Relation to Stress Signaling.

Fibroblast growth factors (FGFs) play important roles in various growth signaling processes, including proliferation, development, and differentiation. Endocrine FGFs, i.e., atypical FGFs, including FGF15/19, FGF21, and FGF23, function as endocrine hormones that regulate energy metabolism. Nutritional status is known to regulate the expression of endocrine FGFs through nuclear hormone receptors. The increased expression of endocrine FGFs regulates energy metabolism processes, such as fatty acid metabolism and glucose metabolism. Recently, a relationship was found between the FGF19 subfamily and stress signaling during stresses such as endoplasmic reticulum stress and oxidative stress. This review focuses on endocrine FGFs and the recent progress in FGF studies in relation to stress signaling. In addition, the relevance of the stress-FGF pathway to disease and human health is discussed.

Impact of Sarcopenia on Postoperative Complications in Obstructive Colorectal Cancer Patients Who Received Stenting as a Bridge to Curative Surgery.

OBJECTIVES: Understanding the relationship between sarcopenia and malignancy is increasingly important since they inevitably affect the aging population. We investigated the clinical significance of sarcopenia in nonmetastatic obstructive colorectal cancer (OCRC) patients who were inserted self-expandable metallic stent and underwent curative surgery. METHODS: Plain cross-sectional CT images obtained before stenting were retrospectively analyzed in 92 patients. Muscle volume loss (myopenia) and decreased muscle quality (myosteatosis) were evaluated as skeletal muscle index (SMI) and intramuscular adipose tissue content (IMAC), respectively. RESULTS: This study included 54 men and 38 women, with a median age of 70.5 years. The median interval between SEMS placement and the surgery was 17 days (range, 5-47). There were 35 postoperative complications. The median postoperative hospital stay was 15.5 days (range, 8-77). Twenty-eight patients (41.3%) were classified as SMI-low, and 31 (34.1%) patients were classified as IMAC-high. In multivariate analysis, IMAC-high [hazard ratio (HR) = 7.68, 95% confidence interval (CI) 2.22-26.5, P = 0.001] and right-sided tumor (HR = 5.79, 95% CI 1.36-24.7, P = 0.018) were independent predictors of postoperative complications. IMAC-high (HR = 23.2, 95% CI 4.11-131, P < 0.001) and elevated modified Glasgow prognostic score (mGPS) (HR = 5.85, 95% CI 1.22-28.1, P = 0.027) were independent predictors of infectious complications. Relapse-free survival and overall survival were not significantly different regardless of the SMI or IMAC status. CONCLUSIONS: IMAC was associated with postoperative complications and infectious complications. Myosteatosis might be a stronger predictor of postoperative complications than myopenia.