Mitofusin-2 prevents skeletal muscle wasting in cancer cachexia.

Cancer cachexia remains a leading cause of morbidity and mortality worldwide, despite extensive research and clinical trials. The prominent clinical feature of cancer cachexia is the continuous loss of skeletal muscle that cannot be fully reversed by conventional nutritional support, and that leads to progressive functional impairment. The mechanism underlying muscle loss in patients with cachexia is poorly understood. The present study analyzed 21 cancer patients with or without cachexia, and demonstrated that mitofusin-2 (Mfn2) was downregulated in the rectus abdominis of patients with cachexia, which was associated with body weight loss. In vitro cell experiments indicated that loss of Mfn2 was associated with atrophy of the C2C12 mouse myoblast cell line. Furthermore, in vivo animal experiments demonstrated that cachexia decreased gastrocnemius muscle mass and Mfn2 expression, and overexpression of Mfn2 in gastrocnemius muscle was able to partially attenuate cachexia-induced gastrocnemius muscle loss. The results of the present study suggested that Mfn2 is involved in cachexia-induced muscle loss and may serve as a potential target for therapy of cachexia.

The Effect of Silencing HIF-1α Gene in BxPC-3 Cell Line on Glycolysis-Related Gene Expression, Cell Growth, Invasion, and Apoptosis.

Hypoxia has been proved to be a typical character of solid tumors. Tumor cells prefer to use glucose through the glycolysis pathway instead of aerobic respiration. However, the precise molecular mechanism underlying this so-called Warburg effect remains elusive. In the current study, siRNA was synthesized and transfected into BxPC-3 cell line to silence the expression of HIF-1α gene. It was found that hypoxia induced hypoxia-inducible factor 1α (HIF-1α) overexpression in BxPC-3 cells, enhanced the expression of pyruvate dehydrogenase kinase 1 and lactate dehydrogenase A, thus facilitating glycolysis and making tumor cells more tolerant to hypoxic stress. The silencing of HIF-1α gene significantly attenuated glycolysis under hypoxic conditions, inhibited the growth and invasion ability of BxPC-3 cells, and enhanced hypoxia-induced cell apoptosis.

Cost and effectiveness of omega-3 fatty acid supplementation in Chinese ICU patients receiving parenteral nutrition.

BACKGROUND AND OBJECTIVES: Clinical evidence supports the use of omega-3 polyunsaturated fatty acid (PUFA)-enriched lipid emulsions in place of standard lipid emulsions in parenteral nutrition (PN) for intensive care unit (ICU) patients, but uptake may be limited by higher costs. We compared clinical and economic outcomes for these two types of lipid emulsion in the Chinese ICU setting. METHODS: We developed a pharmacoeconomic discrete event simulation model, based on efficacy data from an international meta-analysis and patient characteristics, resource consumption, and unit costs from a Chinese institutional setting. Probabilistic sensitivity analyses were undertaken to assess the effects of uncertainty around input parameters. Model predictive validity was assessed by comparing results with data observed in a patient subset not used in the modeling. RESULTS: The model predicted that omega-3 PUFA-enriched emulsion (Omegaven(®) 10% fish oil emulsion) would dominate standard lipid emulsions, with better clinical outcomes and lower overall health care costs (mean savings ~10,000 RMB), mainly as a result of faster recovery and shorter hospital stay (by ~6.5 days). The external validation process confirmed the reliability of the model predictions. CONCLUSION: Omega-3 PUFA-enriched lipid emulsions improved clinical outcome and decreased overall costs in Chinese ICU patients requiring PN.

Lack of effects of HER-2/neu on prognosis in colorectal cancer: a meta-analysis.

BACKGROUND: The prognostic value of human epidermal growth factor receptor-2 (HER-2/neu) for survival of patients with colorectal cancer (CRC) is still ambiguous. We therefore performed a meta-analysis to evaluate its prognostic significance. MATERIALS AND METHODS: We searched the MEDLINE and EMBASE databases for published literature investigating associations between HER-2/neu status and overall survival of patients with CRC. A meta-analysis was performed using a DerSimonian-Laird model and publication bias was investigated by Begg's and Egger's tests. Subgroup analysis was also conducted according to the study design type, study quality score, cut-off value for HER-2/neu overexpression, publication region, patient number and publication year. RESULTS: A total of 17 eligible studies involving 2,347 patients were identified for this meta-analysis. The combined hazard ratio (HR) was 1.31 (95% confidence interval (CI): 0.96-1.79), suggesting that HER-2/neu overexpression was not significantly associated with overall survival of patients with CRC. However, subgroup analysis revealed that HER-2/neu overexpression had an unfavorable impact on survival when the analysis was restricted to subgroups of study quality score ≤ 5 (HR=1.56, 95%CI: 1.17-2.10), Asian patients (HR=1.74, 95%CI: 1.22-2.49), patient number ≤ 106 (HR=1.57, 95%CI: 1.01-2.44), publication year before 2003 (HR=1.59, 95%CI: 1.02-2.49), and prospectively designed study (HR=3.62, 95%CI: 1.42-9.24). The effect disappeared in subgroups of study quality scores > 5 (HR=0.69, 95%CI: 0.33-1.44), non Asian patients (HR=1.14, 95%CI: 0.77-1.70), patients' number > 106 (HR=1.07, 95%CI: 0.67-1.72), publication year after 2003 (HR=1.13, 95%CI: 0.76-1.69), and retrospectively designed study (HR=1.22, 95%CI: 0.89-1.67). CONCLUSIONS: Our meta-analysis suggests that HER-2/neu overexpression might not be a significantly prognostic indicator for patients with CRC. Further studies are required to confirm these results.

[Proteolysis induce factor in the digestive systematic cancer cachexia patients: its expression and role in cancer cachexia].

OBJECTIVE: To demonstrate the expression of proteolysis induce factor(PIF) in the gastrointestinal(GI) cancer cachexia patients and evaluate its role in cancer cachexia. METHODS: Examination of PIF was performed in urine samples from 28 GI cancer cachexia patients, 13 GI cancer patients without cachexia, and 12 weight loss patients with benign disease. PIF was added to the mice cultured C2C12 muscle cells, then the protein kinase B(Akt) phosphorylation and morphological change were measured. RESULTS: The positive rate of PIF in urine of 28 cancer cachexia patients was 53.6%(15/28). In the other two groups, no positive result was detected. PIF could successfully induce Akt phosphorylation, cell atrophy, metamorphosis, and death. The peak of this phosphorylation could be detected after half an hour of the initiation of PIF at a concentration of 4 nmol/L. CONCLUSIONS: PIF is specifically and highly expressed in GI cancer cachexia patients' urine. PIF can induce cancer cachexia possibly by activating Akt phosphorylation and inducing downstream proteolysis.

Pyruvate kinase type M2 is upregulated in colorectal cancer and promotes proliferation and migration of colon cancer cells.

Pyruvate kinase type M2 (PKM2) has been reported to be involved in aerobic glycolysis and cell growth in various tumors. However, the expression pattern of PKM2 in colorectal cancer (CRC) and the correlation between PKM2 expression and CRC remains unclear. The aim of this study is to investigate PKM2 expression and its possible role in CRC. We found that expression of PKM2 was increased in CRC and the increased PKM2 expression was associated with later stage and lymph metastasis of the tumors. Knockdown of PKM2 suppressed the aerobic glycolysis and decreased lactate production of colon cancer RKO cells. Knockdown of PKM2 repressed proliferation and migration of the cells. Inhibition of PKM2 suppressed xenograft tumor growth of RKO cells in vivo. These results suggest that the expression of PKM2 plays a critical role in development of CRC, and it may provide a growth advantage for colon cancer cells. Thus, PKM2 might be a potential therapeutic target for CRC.

Role of beta1-adrenoceptor in increased lipolysis in cancer cachexia.

Increased production of hormone-sensitive lipase (HSL) protein has been demonstrated to be the major cause behind enhanced lipolysis in cancer cachexia. The mechanism governing this alteration is unknown and was presently investigated. This study was conducted to detect the expression of relevant receptors in the adipocytes of cancer cachexia patients, and to elucidate their implication in the increased lipolysis. Gene expressions of beta1-adrenoceptor (ADRB1), beta2-adrenoceptor (ADRB2), beta3-adrenoceptor (ADRB3), alpha2C-adrenoceptor (ADRA2C), natriuretic peptide receptor A (NPRA), insulin receptor (INSR), and HSL were determined in adipose tissues of 34 patients by real-time PCR. Protein levels of ADRB1 and HSL were determined by western blot analysis. beta1-Adrenoceptor (ADRB1) was also detected by immunofluorescence staining. mRNA expressions of both ADRB1 and HSL were approximately 50% elevated selectively in the cachexia group, whereas mRNA levels of the other receptors were unchanged. beta1-Adrenoceptor (ADRB1) protein expression was 1.5-fold increased in cachexia as compared with the cancer controls, and 3-fold increased as compared with nonmalignant controls, and was confirmed as a membrane protein in adipocytes by immunofluorescence. Hormone-sensitive lipase (HSL) protein expression was 2-2.5-fold increased selectively in cachectic patients. There was a positive correlation between the protein expressions of ADRB1 and HSL. As much as approximately 50% of the variations in HSL protein expression could be explained by variations in ADRB1 protein expression. There was a link between ADRB1 protein level and lipolytic rate. Increased ADRB1 expression may account for some of the functional changes of HSL in patients with cancer cachexia.