GB1a Activates SIRT6 to Regulate Lipid Metabolism in Mouse Primary Hepatocytes.

Lipid accumulation, oxidative stress, and inflammation in hepatocytes are features of nonalcoholic fatty liver disease (NAFLD). Garcinia biflavonoid 1a (GB1a) is a natural product capable of hepatic protection. In this study, the effect of GB1a on anti-inflammatory, antioxidant, and regulation of the accumulation in HepG2 cells and mouse primary hepatocytes (MPHs) was investigated, and its regulatory mechanism was further explored. The result showed that GB1a reduced triglyceride (TG) content and lipid accumulation by regulating the expression of SREBP-1c and PPARα; GB1a reduced reactive oxygen species (ROS) and improved cellular oxidative stress to protect mitochondrial morphology by regulating genes Nrf2, HO-1, NQO1, and Keap1; and GB1a reduced the damage of hepatocytes by inhibiting the expression of inflammatory cytokines interleukin-6 (IL-6), interleukin-1ß (IL-1ß), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa B (NF-κB) p65. The activities of GB1a were lost in liver SIRT6-specific knockout mouse primary hepatocytes (SIRT6-LKO MPHs). This indicated that activating SIRT6 was critical for GB1a to perform its activity, and GB1a acted as an agonist of SIRT6. It was speculated that GB1a may be a potential drug for NAFLD treatment.

Reproductive and endocrine effects of artemisinin, piperaquine, and artemisinin-piperaquine combination in rats.

BACKGROUND: The WHO recommends artemisinin-based combination regimens for uncomplicated Plasmodium falciparum malaria. One such combination is artemisinin-piperaquine tablets (ATQ). ATQ has outstanding advantages in anti-malarial, such as good efficacy, fewer side effects, easy promotion and application in deprived regions. However, the data about the reproductive and endocrine toxicity of ATQ remains insufficient. Thus, we assessed the potential effects of ATQ and its individual components artemisinin (ART) and piperaquine (PQ) on the reproductive and endocrine systems in Wistar rats. METHODS: The unfertilized female rats were intragastric administrated with ATQ (20, 40, and 80 mg/kg), PQ (15, 30, and 60 mg/kg), ART (2.5, 5, and 10 mg/kg), or water (control) for 14 days, respectively. The estrous cycle and serum levels of estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), prostaglandin (PG), and adrenocorticotropic hormone (ACTH) were determined. The weights of the kidney, adrenal gland, uterus, and ovaries were measured. The histopathological examinations of the adrenal gland, ovary, uterus, and mammary gland were performed. RESULTS: Compared with the control group, there were no significant differences in the examined items of female rats in the ART groups, including general observation, estrous cycle, hormonal level, organ weight, and histopathological examination. The estrous cycle of female rats was disrupted within 4-7 days after ATQ or PQ administration, and then in a persistent dioestrus phase. At the end of administration, ATQ and PQ at three doses induced decreased PG, increased ACTH, increased adrenal weight and size, and pathological lesions in the adrenal gland and ovary, including vasodilation and hyperemia in the adrenal cortex and medulla as well as hyperplasia and vacuolar degeneration, ovarian corpus luteum surface hyperemia, numerous but small corpus luteum, and disordered follicle development. But the serum levels of E2, FSH, LH, and PRL did not change obviously. These adverse effects in ATQ or PQ treated rats could not completely disappear after 21 days of recovery. CONCLUSION: Based on the results of this study, ART had no obvious reproductive and endocrine effects on female rats, while ATQ and PQ caused adrenal hyperplasia, increased ACTH, decreased PG, blocked estrus, corpus luteum surface hyperemia, and disrupted follicle development in female rats. These events suggest that ATQ and PQ may interfere with the female reproductive and endocrine systems, potentially reducing fertility.

RNA-seq-based transcriptome analysis of the anti-inflammatory effect of artesunate in the early treatment of the mouse cerebral malaria model.

BACKGROUND: cerebral malaria (CM) is an important complication of malaria with a high mortality rate. Artesunate is recommended as the first-line artemisinin compound treatment for severe malaria. Due to the difficulty of obtaining brain tissue samples clinically, the use of animals to research host responses to CM parasite infections is necessary. Rodent malaria models allow for detailed time series studies of host responses in multiple organs. To date, studies on the transcriptome of severe malaria are only limited to the parasites in the peripheral blood of patients, and there is little data on the transcriptional changes in brain tissue in mice with CM treated with artesunate. METHOD AND RESULT: in this study, fresh tissue samples (three biological replicates per mouse) from the same area of the brain in each animal were collected from the uninfected, Plasmodium berghei ANKA-infected and artesunate-treated C57BL/6 mice, and then transcriptome research was performed by the RNA-seq technique. Differentially expressed genes (DEGs) included Il-21, Tnf, Il-6, Il-1ß, Il-10, Ifng, and Icam-1. Among which, Il-6, Il-10, Tnf-α and Il-1ß were further verified and validated via qRT-PCR and ELISA. This revealed that Il-1ß (p < 0.0001), Il-10 (p < 0.05) and Tnf-α (p < 0.05) were significantly up-regulated in the Pb ANKA-infected versus uninfected group, while Il-1ß (p < 0.0001) and Tnf-α (p < 0.05) were significantly down-regulated after artesunate treatment. All DEGs were closely related to the top 3 artesunate treatment pathways, including the JAK-STAT signaling pathway, apoptosis, and Toll-like receptor signaling pathway. CONCLUSION: the mechanism of improving the prognosis of cerebral malaria by artesunate may not only involve the killing of plasmodium but also the inhibition of a cytokine storm in the host. This study provides new insights into the molecular mechanism by which artesunate improves the prognosis of cerebral malaria.

Electrocardiographic effect of artemisinin-piperaquine, dihydroartemisinin-piperaquine, and artemether-lumefantrine treatment in falciparum malaria patients

Abstract INTRODUCTION: Artemisinin-based combination therapy (ACT), such as artemisinin-piperaquine (AP), dihydroartemisinin-piperaquine (DP), and artemether-lumefantrine (AL), is the first-line treatment for malaria in many malaria-endemic areas. However, we lack a detailed evaluation of the cardiotoxicity of these ACTs. This study aimed to analyze the electrocardiographic effects of these three ACTs in malaria patients. METHODS: We analyzed the clinical data of 89 hospitalized patients with falciparum malaria who had received oral doses of three different ACTs. According to the ACTs administered, these patients were divided into three treatment groups: 27 treated with AP (Artequick), 31 with DP (Artekin), and 31 with AL (Coartem). Electrocardiograms and other indicators were recorded before and after the treatment. The QT interval was calculated using Fridericia's formula (QTcF) and Bazett's formula (QTcB). RESULTS: Both QTcF and QTcB interval prolongation occurred in all three groups. The incidence of such prolongation between the three groups was not significantly different. The incidence of both moderate and severe prolongation was not significantly different between the three groups. The ΔQTcF and ΔQTcB of the three groups were not significantly different. The intra-group comparison showed significant prolongation of QTcF after AL treatment. CONCLUSIONS: Clinically recommended doses of DP, AL, and AP may cause QT prolongation in some malaria patients but do not cause torsades de pointes ventricular tachycardia or other arrhythmias.

Effect of artemisinin-piperaquine treatment on the electrocardiogram of malaria patients

Abstract INTRODUCTION: Concern regarding the cardiotoxicity of antimalarials has been renewed because of their potential to cause QT/QTc interval prolongation related to torsade de pointes (TdP). Artemisinin-piperaquine (AP) is considered an effective artemisinin-based combination therapy (ACT) for malaria. METHODS: This study involved a retrospective analysis of clinical data of 93 hospitalized malaria patients who had received AP orally. Electrocardiograms (ECGs) were obtained at specific time points in the original study. RESULTS: Some cases of QT prolongation were observed. However, no TdP was found. CONCLUSIONS: AP may cause QT interval prolongation in some malaria patients but may not lead to TdP.

Evaluation of anti-inflammatory activity of compounds isolated from the rhizome of Ophiopogon japonicas.

BACKGROUND: Ophiopogon japonicas (L.f) Ker-Gawl has been used as a traditional Chinese medicine to cure acute and chronic inflammation and cardiovascular diseases including thrombotic diseases for thousands of years. Previous phytochemical studies showed that O. japonicus contained compounds with anti-inflammatory activity. The aim of this study was to identify and isolate compounds with anti-inflammatory activity from the rhizome of O. japonicas. METHODS: Compounds were isolated by various column chromatography and their structures were identified in terms of nuclear magnetic resonance spectrum (NMR) and mass spectrum (MS). To measure the anti-inflammatory effects of thirteen compounds in LPS-induced RAW 264.7 macrophage cells, we used the following methods: cell viability assay, nitric oxide assay, enzyme-linked immunosorbent assay, quantitative real-time PCR analysis and western blotting analysis. RESULTS: One new and twelve known compounds (mainly homoisoflavonoids) were extracted from O. japonicas, in which 4'-O-Demethylophiopogonanone E (10) was considered as a new compound, additionally, compounds 4-O-(2-Hydroxy-1- hydroxymethylethyl)-dihydroconiferyl alcohol (2) and 5,7-dihydroxy-6-methyl-3-(2', 4'-dihydroxybenzyl) chroman-4-one (12) were isolated from the rhizome of O. japonicas for the first time. The isolated compounds Oleic acid (3), Palmitic acid (4), desmethylisoophiopogonone B [5,7-dihydroxy-3-(4'-hydroxybenzyl)-8- methyl- chromone] (5), 5,7-dihydroxy-6-methyl-3-(4'-hydroxybenzyl) chromone (7) and 10 significantly suppressed the production of NO in LPS-induced RAW 264.7 cells. Especially compound 10 showed the strongest effect against the production of the pro-inflammatory cytokine IL-1ß and IL-6 with the IC50 value of 32.5 ± 3.5 µg/mL and 13.4 ± 2.3 µg/mL, respectively. Further analysis elucidated that the anti-inflammatory activity of compound 10 might be exerted through inhibiting the phosphorylation of ERK1/2 and JNK in MAPK signaling pathways to decrease NO and pro-inflammatory cytokines production. CONCLUSIONS: Our results indicated that 4'-O-Demethylophiopogonanone E can be considered as a potential source of therapeutic medicine for inflammatory diseases.

China-Africa cooperation initiatives in malaria control and elimination.

Malaria has affected human health globally with a significant burden of disease, and also has impeded social and economic development in the areas where it is present. In Africa, many countries have faced serious challenges in controlling malaria, in part due to major limitations in public health systems and primary health care infrastructure. Although China is a developing country, a set of control strategies and measures in different local settings have been implemented successfully by the National Malaria Control Programme over the last 60 years, with a low cost of investment. It is expected that Chinese experience may benefit malaria control in Africa. This review will address the importance and possibility of China-Africa collaboration in control of malaria in targeted African countries, as well as how to proceed toward the goal of elimination where this is technically feasible.

[The clinical, endoscopic and pathologic features of Crohn's disease in the differentiation from intestinal tuberculosis].

OBJECTIVE: To investigate the clinical, endoscopic and pathologic features in the differential diagnosis between Crohn's disease(CD) and intestinal tuberculosis (ITB). METHODS: The complete clinical data of 107 patients with CD and 69 patients with ITB in our hospital from January 2011 to January 2012 were retrospectively analyzed. The diagnostic value of the clinical and endoscopic scoring system was evaluated. RESULTS: CD occurred mainly in male. The salient features of CD included long duration of disease high incidence of colectomy. Comparing with patients with ITB, patients with CD have more cases of diarrhea, hematochezia, abdominal mass, intestinal obstruction, intestinal hemorrhage, perianal lesions, and extraintestinal manifestations (all P < 0.05).It's more frequent to have positive results of anti-Saccharomyces cerevisiae antibody (ASCA), perinuclear antineutrophil cytoplasmic antibody (pANCA) and fecal occult blood in CD patients, as well as low albumin, high C-reactive protein ( CRP), elevated platelet count and hematocrit (P < 0.05 or P < 0.01). The salient features of ITB included low fever, night sweats, active parenteral tuberculosis, increased erythrocyte sedimentation rate (ESR), chest X-ray abnormalities, the positive PPD (purified protein derivatives tuberculin) and T-SPOT (P < 0.05 or P < 0.01). Based on the imaging, CD often involved the small intestine, such as the intestinal stricture and abdominal abscess (P < 0.05), while mesenteric lymphadenopathy was more common in ITB (P < 0.05). The endoscopic examination showed that some patterns of disease involvement such as fissure-shape ulcer [41.12% (44/107) vs 5.80% (4/69)], cobblestone sign[15.89% (17/107) vs 4.35% (3/69)], lesions over four segment [24.30% (26/107) vs 7.25% (5/69)], rectum involvement [17.76% (19/107) vs 5.80% (4/69)], ileocecal valve stenosis [21.50% (23/107) vs 8.70% (6/69)] and mucosal bridge[5.61% (6/107) vs 0(0/69)] were more frequent in CD patients than those in ITB patients(P < 0.01 or P < 0.05). However circular ulcers[37.68% (26/69) vs 9.35% (10/107)], rat-bite-like ulcers[24.64% (17/69) vs 12.15% (13/107)], persistent open ileocecal valves [39.13% (27/69) vs 19.63% (21/107)], tuberous and polypoid lesions[36.23% (25/69) vs 20.56% (22/107), 37.68% (26/69) vs 22.43% (24/107)] were more common in ITB (P < 0.01 or P < 0.05). In terms of pathological findings, certain characteristic features such as transmural inflammation [5.61% (6/107) vs 0(0/69)], fissure-liked ulcers [14.02% (15/107) vs 4.35% (3/69)], non-caseous granulomas [5.61% (6/107) vs 0(0/69)], lymphoid hyperplasia [16.82% (18/107) vs 5.80% (4/69)] and crypt abscess [9.35% (10/107) vs 1.45% (1/69)] were more common in CD than those in ITB(P < 0.05). According to the clinical and endoscopic scoring system, the positive diagnostic rate of CD was 50.47% (54/107) and of ITB was 66.67% (46/69) (P < 0.05) . CONCLUSIONS: The differential diagnosis between CD and ITB should be considered carefully based on clinical, endoscopic, pathological characteristics. The clinical and endoscopic scoring system may contribute to distinguish CD and ITB.

Neuroprotective effect of granulocyte colony-stimulating factor in a focal cerebral ischemic rat model with hyperlipidemia.

Granulocyte colony-stimulating factor (G-CSF) has been demonstrated to have neuroprotective effects in rat model with focal cerebral ischemia through anti-apoptotic pathways and by promoting proliferation of neural stem cells. In the present study, we examined the neuroprotective effect of G-CSF in an acute focal cerebral ischemia rat model with lipid metabolism disorder. Eighty male SD rats were randomly divided into normal diet control group (NC group) and high-fat diet group (HFD group) (n = 40 in each). In HFD group, rats were fed on high fat diet to induce atherosclerosis. After 29 days, 4 rats from each group were sacrificed to evaluate the effects of different diets, and the middle cerebral artery occlusion (MCAO) was performed in the rest of the rats. MCAO rats received either G-CSF (50 µg·kg(-1)·mL(-1)) or phosphate buffered saline (PBS) injection through the external jugular vein for 5 days, which was followed by 5-bromo-deoxy uridine (BrdU, i.p., 50 mg/kg) injection for another 7 days. To evaluate the effects of G-CSF treatment on neurological function, the modified neurological severity score (mNSS) was calculated. The vascular distribution, ischemic cells proliferation, cell apoptosis and the expression of vascular endothelial growth factor (VEGF) were measured to determine the effects of G-CSF treatment. Our results showed that G-CSF-treated rats had a lower mNSS than PBS-treated rats in both NC group and HFD group. G-CSF injection promoted endothelial cell proliferation and vascular regeneration, and inhibited cell apoptosis. The serum and tissue levels of VEGF were significantly increased after G-CSF treatment. It is concluded that G-CSF exerts its neuroprotective effect in focal cerebral ischemia rats with hyperlipidemia by enhancing angiogenesis, promoting cells proliferation, decreasing cell apoptosis, and increasing local VEGF expression.

Interleukin-18 and -12 synergistically enhance cytotoxic functions of tumor-infiltrating lymphocytes.

BACKGROUND: The role of tumor-infiltrating lymphocytes (TILs) in the immunopathogenesis of individual cancer is not clear and is a challenge for anti-tumor immunotherapy. This study aimed to investigate the effects of interleukin (IL)-18 and -12 on cytotoxic functions of TILs. METHODS: TILs from postoperative gastric cancer patients were costimulated with IL-18 and IL-12. SGC-7901 tumor cells were pre-incubated with TILs and subcutaneously injected into BALB/C SCID mice. The function of TILs was evaluated by measuring tumor sizes in tumor-bearing mice, T helper (Th)1 (tumor necrosis factor (TNF)-α, interferon (IFN)-γ) and Th2 cytokine levels (IL-10 and IL-4) in serum and cytotoxicity of mouse natural killer (NK) and CD8(+) T cells. RESULTS: IL-18 and IL-12 synergistically inhibited the growth of SGC-7901 cells in vivo and significantly extended the survival rate of SGC-7901-bearing mice (66.7% vs. 13.7%, P < 0.01). Moreover, TILs could promote the secretion of TNF-α and IFN-γ ((130.34 ± 7.65) vs. (210.63 ± 12.31) pg/ml, P < 0.01; (14.23 ± 1.97) vs. (30.52 ± 2.12) pg/ml, P < 0.01), and downregulate IL-10 and IL-4 secretion ((103.72 ± 11.21) vs. (61.36 ± 5.41) pg/ml, P = 0.021; (49.36 ± 4.67) vs. (28.48 ± 3.86) pg/ml, P = 0.024). CONCLUSION: IL-18 and IL-12 can synergistically enhance cytotoxic functions of TILs from human gastric cancer.

Knockdown of Bmi-1 impairs growth and invasiveness of human gastric carcinoma cells.

The effect of B cell-specific MLV integration site-1 (Bmi-1) RNA interference (RNAi)-mediated inhibition of Bmi-1 expression on the proliferation, apoptosis, and invasiveness of human gastric carcinoma AGS cells was investigated. RT-PCR and Western blot analyses demonstrated that Bmi-1 expression and the Bmi-1 protein level were significantly decreased in Bmi-1 shRNA transfected AGS cells compared to untransfected and nonspecific shRNA transfected AGS cells. Bmi-1 RNAi-mediated inhibition of Bmi-1 expression significantly affected cell growth and invasiveness, and resulted in increased AGS cell apoptosis. This was not observed in untransfected and nonspecific shRNA transfected AGS cells. Inhibition of Bmi-1 expression in human gastric carcinoma cells affects cell proliferation and invasiveness.

Flow-dependent regulation of vascular function and gene expression in rat superior mesenteric artery.

BACKGROUND: Mesenteric artery thrombosis is prone to occur at specific arterial regions with different fluid flow patterns, yet mechanistic links between blood flow and vascular function remain unclear. This study aimd to investigate the role of blood flow in regulation of vascular function and gene expression in rats. METHODS: Isometric tension was recorded in wire myograph to examine vascular function of specific regions (trunk parts and proximal parts from the origin) with different blood flow in superior mesenteric artery (SMA). Endothelial nitric oxide syntheses (eNOS), phosphorylated-eNOS (p-eNOS), serine-threonine kinase Akt and phosphorylated-Akt (p-Akt) protein expressions in SMA were examined by Western blotting. Significance was analyzed using a Student's t test or analysis of variance (ANOVA) followed by a Dunnett's multiple-comparison post hoc test. RESULTS: Compared with trunks, proximal parts exhibited severely impaired relaxant responses to acetylcholine (Ach) (1 nmol/L to 10 micromol/L) (P < 0.01). p-eNOS and p-Akt protein levels were significantly reduced in proximal parts of SMA (0.37 +/- 0.03, 0.42 +/- 0.03 respectively) versus trunk parts (0.82 +/- 0.03, 0.72 +/- 0.03 respectively, both P < 0.05) while total eNOS and Akt expressions remain comparable in both regions by Western blotting analysis (0.70 +/- 0.03 vs 0.82 +/- 0.03; 0.70 +/- 0.03 vs 0.77 +/- 0.03 respectively, both P > 0.05). CONCLUSION: Critical components that drive the vascular function and influence the localization of mesenteric artery thrombosis are flow-responsive elements within the vascular endothelium.

Effect of p27mt gene on apoptosis of the colorectal cancer cell line Lovo.

AIM: To construct p27mt recombinant adenovirus, transfect the colorectal cell line Lovo and observe the effects of p27mt on Lovo cell apoptosis and cell cycle inhibition. METHODS: We constructed recombinant adenovirus containing p27mt by homologous recombination in bacteria. The colorectal cancer cell line Lovo was infected with recombinant replication-defective adenovirus Ad-p27mt, and expression of p27mt was determined by Western blotting; the inhibitory effect of p27mt on Lovo cells was detected by cytometry. Cell cycle was determined by flow cytometry. DNA fragment analysis identified the occurrence of apoptosis. RESULTS: The recombinant adenovirus which already contained p27mt target gene was successfully constructed. When multiplicity of infection was >or= 50, the infection efficiency was 100%. After transfection of Lovo cells with Ad-p27mt the cells had high p27 expression which was identified by immunoblotting assay. PI staining and flow cytometry showed that 77.96% of colorectal cancer cells were inhibited in phase G(0)/G(1), while in the Ad-LacZ group and blank control group, 27.57% and 25.29% cells were inhibited in the same phase, respectively. DNA fragment analysis, flow cytometry and TUNEL assay demonstrated that p27mt is able to induce apoptosis in colorectal cancer cells. CONCLUSION: p27mt has an obvious blocking effect on colorectal cancer cell cycle, and most cells were inhibited in phase G(0)/G(1). Therefore, p27mt can induce apoptosis in colorectal cells.

Antitumor bioactivity of adenovirus-mediated p27mt in colorectal cancer cell line SW480.

AIM: To explore the antitumor bioactivity of adenovirus-mediated mutant type p27(kip1) gene in a colorectal cancer cell line SW480. METHODS: We constructed recombinant adenovirus vector expressing a mutant type p27(kip1) gene (ad-p27mt), with mutation of Thr-187/Pro-188 (ACGCCC) to Met-187/Ile-188 (ATGATC), and transduced into SW480 cells. Then we detected expression of p27, Bcl-2 and Bax protein in the transductants by Western blotting, cell cycle of transductants by a digital flow cytometric system, migrating potential with Boyden Chamber and SW480 tumor cell growth inhibition in vitro and in vivo. RESULTS: We found that a recombinant adenovirus vector of expressing ad-p27mt, with mutation of Thr-187/Pro-188 (ACGCCC) to Met-187/Ile-188 (ATGATC) has potent inhibition of SW480 tumor cell growth in vitro and in vivo. Furthermore, ad-p27mt induced cell apoptosis via regulating bax and bcl-2 expressions, and G(1)/S arrest in SW480 cells and inhibited cell migration. CONCLUSION: ad-p27mt has a strong anti-tumor bioactivity and has the potential to develop into new therapeutic agents for colorectal cancer.

Inhibitory effect of siRNA targeting survivin in gastric cancer MGC-803 cells.

Gastric cancer is the fourth most common cancer in the world and the leading cause of cancer death in China. It is necessary to find a safe and effective way to treat this disease. A sustained overexpression of survivin is a characteristic feature of gastric cancer as it gives cancer cells a survival and growth advantage. RNA interference (RNAi), which has been proven to be a powerful tool for suppressing gene expression, may provide a promising way forward in gastric cancer therapy. Few studies have been conducted on the inhibitory effects of small interfering RNA (siRNA) against survivin in gastric cancer. In this study, we constructed the recombinant Psilencer 2.1-survivin siRNA plasmids and transfected them into gastric cancer MGC-803 cells in vitro, and also injected MGC-803/Silence (+) cells into nude mice to observe the inhibitory effects in vivo. The transfection of Psilencer 2.1-survivin (+) plasmid led to remarkable inhibition of survivin mRNA expression, the intensity of survivin mRNA was lower (P<0.05), the expression of survivin protein was strongly suppressed, the amount of survivin protein was also lower (P<0.05) and the percentage of apoptotic cells was much higher (P<0.05). The tumor size and growth ratio were lower in nude mice injected with MGC-803/Silence (+) cells and the inhibition ratio of survivin expression was higher (P<0.05). In summary, siRNA targeting of survivin can effectively inhibit the growth of gastric cancer cells and may be used as a potent therapy.

Expression of angiopoietin-2 is correlated with vascularization and tumor size in human colorectal adenocarcinoma.

Angiopoietins are endothelial growth factors, which play crucial roles in normal vascular development and tumor angiogenesis. We examined the expression profiles of angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), vascular endothelial growth factor (VEGF), and Tie-2, a receptor for Ang-1 and Ang-2, in both colorectal adenocarcinoma and adjacent normal tissues, as judged by histology, in order to elucidate their relationships with microvascular density (MVD) and clinicopathologic properties. Higher MVD was associated with a lower degree of differentiation of colorectal adenocarcinoma. Immunohistochemical analysis revealed that the expression of Ang-2 and VEGF was significantly increased in colorectal adenocarcinoma compared to adjacent normal tissues (p < 0.01), and the expression of Ang-2 positively correlated with that of VEGF (r = 0.997, p < 0.01). In contrast, the expression of Ang-1 was lower in adenocarcinoma tissues than in adjacent normal tissues (p < 0.01), while there was no significant difference in Tie-2 expression in both tissues. Moreover, MVD was increased in Ang-2- and VEGF-expressing adenocarcinoma tissues compared to the Ang-2- and VEGF-negative tissues, respectively (p < 0.01). Importantly, MVD was lower in Ang-1-expressing adenocarcinoma tissues relative to Ang-1-negative tissues (p < 0.01). Furthermore, expression of Ang-2 as well as VEGF was significantly up-regulated in colorectal adenocarcinoma with diameters > or = 5 cm or with lymph-node metastases (p < 0.01). In conclusion, the increased expression of Ang-2 and the decreased expression of Ang-1 may be responsible for blood vessel formation and rapid growth of the colorectal adenocarcinoma.

Peroxisome proliferator-activated receptor gamma agonists inhibit the proliferation and invasion of human colon cancer cells.

BACKGROUND AND AIMS: Data regarding the effect of peroxisome proliferator-activated receptor gamma (PPAR-gamma) ligands on the invasive ability of colon cancer cells are currently limited. This study was designed to examine the effects of PPAR-gamma agonists on the proliferation and invasion of two colon cancer cells to identify the role of PPAR-gamma in colon cancer growth and metastasis. METHODS: SW480 and LS174T cells were treated with PPAR-gamma ligands, pioglitazone and 15-deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2), as well as their combinations with the PPAR-gamma antagonist GW9662. MTT assay was used to determine the antiproliferative effects. Cell cycle analysis was conducted by flow cytometry. The mRNA and protein expression were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and western blot, respectively. The invasive ability of cells was determined by the BD BioCoat Matrige invasion chamber. RESULTS: Pioglitazone and 15d-PGJ2 inhibited the proliferation of both colon cancer cell lines in a dose-dependent manner. This growth inhibitory effect was reversed by GW9662. Results from flow cytometry demonstrated G1 arrest following treatment with pioglitazone and 15d-PGJ2. The expression of matrix metalloproteinase-7 (MMP-7) was only detected in LS174T cells, while its tissue inhibitor-1 (TIMP-1) was expressed in both colon cancer cells. 15d-PGJ2 and pioglitazone downregulated MMP-7 expression and upregulated TIMP-1 expression. PPAR-gamma agonists can only inhibit invasive activity of LS174T cells. CONCLUSIONS: PPAR-gamma agonists have inhibitory effects on the proliferation of colon cancer cell lines associated with G1 cell cycle arrest and invasive activity. The latter effect is demonstrated in certain cell lines through the down-regulation of MMP-7 synthesis.

[Effects of anti-angiopoietin-2 antibody on vascularization of an implanted model of human colonic carcinoma on chick embryo].

OBJECTIVE: To establish an implanted model of human colonic carcinoma on chick embryo, and to study the effects of anti-angiopoietin-2 antibody on its vascularization. METHODS: The human colonic adenocarcinoma cell line HT-29 was transplanted on the chick embryo's chorioallantoic membrane(CAM), and the angiogenesis characteristics were observed by stero-microscope, light microscope and immunohistochemistry. Furthermore, the effects of anti-angiopoietin-2 antibody on angiogenesis and tumor growth were also investigated. RESULTS: Three to seven days after HT-29 cell line was implanted into CAM, tumors grew rapidly and new blood vessels grew toward tumors. Five days after anti-angiopoietin-2 antibody was given, the number of blood vessels in anti-angiopoietin-2 antibody group was significantly down-regulated than that in tumor control group observed by stero-microscope (37.2+/-4.6 vs 56.8+/-7.4, P<0.01), but was up-regulated than that in normal control group (37.2+/-4.6 vs 9.6+/-2.4, P<0.01). Microvessel density(MVD) in anti-angiopoietin-2 antibody group was much lower than that in tumor control group by histological examination (9.6+/-2.4 vs 20.2+/-5.8, P<0.01). CONCLUSION: Angiopoietin-2 antibody is able to inhibit the angiogenesis induced by colorectal cancer cell line HT-29 obviously. The anti-angiopoietin-2 antibody may be potentially useful for clinical treatment of colonic carcinoma.

Risk factors for ulcerative colitis in a Chinese population: an age-matched and sex-matched case-control study.

BACKGROUND AND AIMS: Cigarette smoking, alcohol use, appendectomy, and family history of inflammatory bowel disease (IBD) have all been shown to be associated with IBD, but there were no reports of risk factors for IBD in a Chinese population in which the incidence of IBD is increasing during the past decade. We conducted a case-control study to examine associations between previously reported environmental risk factors and development of ulcerative colitis (UC) in Wuhan city, central China. METHODS: A total of 177 patients with UC and 177 age-matched and sex-matched controls were prospectively studied in Wuhan city from January 2004 to December 2004. An age-matched and sex-matched case-control study was conducted to assess the role of smoking, alcohol use, appendectomy, and other potential risk factors in the development of UC by a detailed questionnaire. RESULTS: Smoking was a protective factor and exsmoking is a risk factor for UC [compared with nonsmokers, smokers: odds ratios (OR)=0.28, 95% confidence intervals (CI): 0.16-0.48, P=0.0001; exsmokers: OR=4.36, 95%CI: 1.46-13.04, P=0.008]. Positive family history of IBD was a risk factor (OR=4.35, 95%CI: 1.21-15.71, P=0.025) whereas appendectomy was a protective factor (OR=0.24, 95%CI: 0.07-0.86, P=0.028) for UC. There were no significant associations between UC and other factors examined. CONCLUSIONS: Although the incidence of UC in Chinese is relatively lower than that in white, the same risk factors for UC that were reported in white populations were associated with Chinese UC patients. Specifically, smoking was a protective factor for UC and exsmoking was associated with an increase risk of UC in a Chinese population. Family history of IBD was shown to be a risk for UC, whereas appendectomy was associated with a low risk for UC.

Mitochondria-dependent apoptosis induced by nanoscale hydroxyapatite in human gastric cancer SGC-7901 cells.

Nanoscale hydroxyapatite (nano-HAP) has been reported to exhibit anti-cancer effect on several human cancers, but the molecular mechanism of which remains unclear. The aim of this study was to explore the mechanisms by investigating the effects of nano-HAP on human gastric cancer SGC-7901 cells. Our results showed that nano-HAP significantly reduced cell viability, and induced apoptosis in SGC-7901 cells characterized by hypodiploid DNA contents, morphological changes and DNA fragmentation. The increase in apoptosis was accompanied with the increased expression of Bax, a pro-apoptotic protein, and decreased expression of Bcl-2, an anti-apoptotic protein, the decrease of mitochondrial membrane potential and the release of cytochrome c from mitochondria into cytosol. Furthermore, the activation of caspases-3, and -9, but not activation of caspases-8 was induced by nano-HAP. Z-VAD-fmk, a universal caspase inhibitor, dose-dependently inhibited nano-HAP-induced apoptosis. This study demonstrates that nano-HAP inhibits the proliferation of SGC-7901 cells by inducing apoptosis, and the apoptotic pathway of nano-HAP-induced apoptosis is mediated through the mitochondrial-dependent and caspase-dependent pathway.