Metabolic enzymes: key modulators of functionality in cancer stem-like cells.

Cancer Stem-like Cells (CSCs) are a subpopulation of cancer cells with self-renewal capacity and are important for the initiation, progression and recurrence of cancer diseases. The metabolic profile of CSCs is consistent with their stem-like properties. Studies have indicated that enzymes, the main regulators of cellular metabolism, dictate functionalities of CSCs in both catalysis-dependent and catalysis-independent manners. This paper reviews diverse studies of metabolic enzymes, and describes the effects of these enzymes on metabolic adaptation, gene transcription and signal transduction, in CSCs.

The virus-induced protein APOBEC3G inhibits anoikis by activation of Akt kinase in pancreatic cancer cells.

Pancreatic cancer is one of the more common cancers with a poor prognosis. Some varieties of cancer are related to virus infection. As a virus-induced protein, APOBEC3G (A3G) presents extensive anti-virus ability, but the role of A3G in pancreatic cancer was previously unknown. The expression of A3G in pancreatic cancer was examined using TaqMan real-time qPCR, immunohistochemical and immunofluorescent staining. Subsequently, the role of A3G in pancreatic cancer was evaluated in vivo using the tumor xenograft model. Anoikis was detected by colony formation assay and flow cytometry in vitro. The Akt kinase activity and target protein PTEN were examined by co-immunoprecipitation and immunoblot. The virus-induced protein A3G was significantly up-regulated in pancreatic cancer, and the up-regulation of A3G promoted xenograft tumor formation. A3G inactivated PTEN by binding to the C2 tensin-type and PDZ domains, thereby inducing anoikis resistance through Akt activation. Our results demonstrate that the up-regulation of A3G in pancreatic cancer cells induces anoikis resistance, and they provide novel insight into the mechanism by which A3G affects the malignant behavior of pancreatic cancer cells.

Biochemical metabolic changes assessed by 31P magnetic resonance spectroscopy after radiation-induced hepatic injury in rabbits.

AIM: To compare the features of biochemical metabolic changes detected by hepatic phosphorus-31 magnetic resonance spectroscopy ((31)P MRS) with the liver damage score (LDS) and pathologic changes in rabbits and to investigate the diagnostic value of (31)P MRS in acute hepatic radiation injury. METHODS: A total of 30 rabbits received different radiation doses (ranging 5-20 Gy) to establish acute hepatic injury models. Blood biochemical tests, (31)P MRS and pathological examinations were carried out 24 h after irradiation. The degree of injury was evaluated according to LDS and pathology. Ten healthy rabbits served as controls. The MR examination was performed on a 1.5 T imager using a (1)H/(31)P surface coil by the 2D chemical shift imaging technique. The relative quantities of phosphomonoesters (PME), phosphodiesters (PDE), inorganic phosphate (Pi) and adenosine triphosphate (ATP) were measured. The data were statistically analyzed. RESULTS: (1) Relative quantification of phosphorus metabolites: (a) ATP: there were significant differences (P < 0.05) (LDS-groups: control group vs mild group vs moderate group vs severe group, 1.83 +/- 0.33 vs 1.55 +/- 0.24 vs 1.27 +/- 0.09 vs 0.98 +/- 0.18; pathological groups: control group vs mild group vs moderate group vs severe group, 1.83 +/- 0.33 vs 1.58 +/- 0.25 vs 1.32 +/- 0.07 vs 1.02 +/- 0.18) of ATP relative quantification among control group, mild injured group, moderate injured group, and severe injured group according to both LDS grading and pathological grading, respectively, and it decreased progressively with the increased degree of injury (r = -0.723, P = 0.000). (b) PME and Pi; the relative quantification of PME and Pi decreased significantly in the severe injured group, and the difference between the control group and severe injured group was significant (P < 0.05) (PME: LDS-control group vs LDS-severe group, 0.86 +/- 0.23 vs 0.58 +/- 0.22, P = 0.031; pathological control group vs pathological severe group, 0.86 +/- 0.23 vs 0.60 +/- 0.21, P = 0.037; Pi: LDS-control group vs LDS-severe group, 0.74 +/- 0.18 vs 0.43 +/- 0.14, P = 0.013; pathological control group vs pathological severe group, 0.74 +/- 0.18 vs 0.43 +/- 0.14, P = 0.005) according to LDS grading and pathological grading, respectively. (c) PDE; there were no significant differences among groups according to LDS grading, and no significant differences between the control group and experimental groups according to pathological grading. (2) The ratio of relative quantification of phosphorus metabolites: significant differences (P < 0.05) (LDS-moderate group and LDS-severe group vs LDS-control group and LDS-mild group, 1.94 +/- 0.50 and 1.96 +/- 0.72 vs 1.43 +/- 0.31 and 1.40 +/- 0.38) were only found in PDE/ATP between the moderate injured group, the severe injured group and the control group, the mild injured group. No significant difference was found in other ratios of relative quantification of phosphorus metabolites. CONCLUSION: (31)P MRS is a useful method to evaluate early acute hepatic radiation injury. The relative quantification of hepatic ATP levels, which can reflect the pathological severity of acute hepatic radiation injury, is correlated with LDS.

Protective effect of salvianolic acid B on chronic pancreatitis induced by trinitrobenzene sulfonic acid solution in rats.

OBJECTIVES: To investigate the effects of salvianolic acid B (Sal-B) on pancreatic damage in experimental chronic pancreatitis. METHODS: Chronic pancreatitis was induced by infusion of trinitrobenzene sulfonic acid into the pancreatic duct in male Sprague-Dawley rats. From the beginning of 5 weeks, the rats in group 2 were treated with Sal-B by gavage for 8 weeks. Salvianolic acid B was given at a daily dose of 10 mg/kg body weight. At the end of 12 weeks, the levels of serum biochemical indexes were measured on an automatic biochemical analyzer; serum hyaluronic acid and laminin levels were determined by radioimmunoassay; pancreatic tissue malondialdehyde (MDA) was analyzed, and the degree of pancreatic damage was determined. RESULTS: The level of serum biochemical indexes were similar in all groups (P > 0.05 for all). Salvianolic acid B treatment did not obviously reduce hyaluronic acid and laminin concentration in blood (P > 0.05). Salvianolic acid B treatment decreased MDA concentration in pancreatic tissue (P < 0.01). Salvianolic acid B clearly improved pancreatic histological findings and prevented the activation of pancreatic stellate cells. CONCLUSIONS: Sal-B treatment decreased MDA concentration in pancreatic tissue, attenuated morphological pancreatic damage, and prevented the activation of pancreatic stellate cells in experimental chronic pancreatitis.

[Antitumor effects of novel triterpene from Celastrus hypoleucus on human colorectal cancer cell line RKO in vitro].

OBJECTIVE: To investigate the effects of novel triterpene (12-oleanene-3beta, 6alpha-diol) from Celastrus hypoleucus on the proliferation and apoptosis of human colorectal cancer cell line RKO. METHOD: The inhibitory effect of the novel triterpene on RKO cell proliferation was assayed by MTT dye reduction. The morphology of apoptotic cells was observed with AO/EB double fluorescence staining and HE staining, DNA fragment with electrophoresis on agarose gels, sub-diploid peak and cell cycle with flow cytometer (FCM). RESULT: Novel triterpene (12-oleanene-3beta, 6alpha-diol) from C. hypoleucus significantly inhibited proliferation of RKO cells in dose-dependent and time-dependent manner, the IC50 was (12.20 +/- 0.79) microg x mL(-1) at 48 h. Typical apoptotic changes were observed in RKO cells under the fluorescence microscope and the light microscope. DNA ladder was detected on agarose gels at concentrations from 10 microg x mL(-1) to 20 microg x mL(-1) at 48 h. With FCM methods, dose-dependent apoptosis-induced effect was observed in RKO cell line after treatment of triterpene for 48 h, and the apoptotic rates were increased from(2.93 +/- 0.84) % to (50.79 +/- 6.61) % at concentrations from 2.5 microg x mL(-1) to 20 microg x mL(-1). DNA histograms data from FCM analysis showed that the number of cells was obviously reduced during G0-G1 phase and G2-M phase, but not during S phase for RKO cell line after treatment with various concentrations of the triterpene for 48 hours. CONCLUSION: Novel triterpene (12-oleanene-3beta, 6alpha-diol) from C. hypoleucus can induce apoptosis and has inhibition effect on the proliferation in RKO cell line.

Novel skeleton terpenes from Celastrus hypoleucus with anti-tumor activities.

Celahypodiol 1, an unusual 17-membered carbon diterpenoid with a novel skeleton, and a new triterpenoid 12-oleanene-3beta,6alpha-diol 2, together with four known compounds furreginol 3, suigol 4, 20(30)-lupene-3beta, 29-diol 5, and 20(29)-lupene-1beta,3beta-diol 6, were isolated from the stalks of Celastrus hypoleucus (Oliv.) Warb. Their structures were established by means of spectroscopic analysis, including 2D NMR. The new compounds exhibited anti-tumor activities against a panel of human tumor cell lines.