Suppression of colorectal cancer metastasis by nigericin through inhibition of epithelial-mesenchymal transition

AIM: To evaluate the effect of nigericin on colorectal cancer and to explore its possible mechanism.METHODS: The human colorectal cancer (CRC) cell lines HT29 and SW480 were treated with nigericin or oxaliplatin under the conditions specified. Cell viability assay and invasion and metastasis assay were performed to evaluate the effect of nigericin on CRC cells. Sphere-forming assay and soft agar colony-forming assay were implemented to assess the action of nigericin on the cancer stem cell properties of CRC cells undergone epithelial-mesenchymal transition (EMT).RESULTS: Compared with oxaliplatin, nigericin showed more toxicity for the HT29 cell line (IC50, 12.92 ± 0.25 μmol vs 37.68 ± 0.34 μmol). A similar result was also obtained with the SW116 cell line (IC50, 15.86 ± 0.18 μmol vs 41.02 ± 0.23 μmol). A Boyden chamber assay indicated that a significant decrease in the number of HT29 cells migrating through polyvinylidene fluoride membrane was observed in the nigericin-treated group, relative to the vehicle-treated group [11 ± 2 cells per high-power field (HPF) vs 19.33 ± 1.52 cells per HPF, P < 0.05]. Compared to the control group, the numbers of HT29 cells invading through the Matrigel-coated membrane also decreased in the nigericin-treated group (6.66 ± 1.52 cells per HPF vs 14.66 ± 1.52 cells per HPF, P < 0.05). Nigericin also reduced the proportion of CD133⁺ cells from 83.57% to 63.93%, relative to the control group (P < 0.05). Nigericin decreased the number of spheres relative to the control group (0.14 ± 0.01 vs 0.35 ± 0.01, P < 0.05), while oxaliplatin increased the number of spheres relative to the control group (0.75 ± 0.02 vs 0.35 ± 0.01; P < 0.05). Nigericin also showed a decreased ability to form colonies under anchorage-independent conditions in a standard soft agar assay after 14 d in culture, relative to the control group (1.66 ± 0.57 vs 7 ± 1.15, P < 0.05), whereas the colony numbers were higher in the oxaliplatin group relative to the vehicle-treated controls (14.33 ± 0.57 vs 7 ± 1.15, P < 0.05). We further detected the expression of E-cadherin and vimentin in cells treated with nigericin and oxaliplatin. The results showed that HT29 cells treated with nigericin induced an increase in E-cadherin expression and a decrease in the vimentin expression relative to vehicle controls. In contrast, oxaliplatin downregulated the expression of E-cadherin and upregulated the expression of vimentin in HT29 cells relative to vehicle controls.CONCLUSION: This study demonstrated that nigericin could partly reverse the EMT process during cell invasion and metastasis.     

Immunohistochemical expression of SP-NK-1R-EGFR pathway and VDR in colonic inflammation and neoplasia

AIM:To determine the expression of neurokinin-1receptor(NK-1R),phosphorylated epidermal growth factor receptor(p EGFR),cyclooxygenase-2(Cox-2),and vitamin D receptor(VDR)in normal,inflammatory bowel disease(IBD),and colorectal neoplasia tissues from Puerto Ricans.METHODS:Tissues from patients with IBD,colitisassociated colorectal cancer(CAC),sporadic dysplasia,and sporadic colorectal cancer(CRC),as well as normal controls,were identified at several centers in Puerto Rico.Archival formalin-fixed,paraffin-embedded tissues were de-identified and processed by immunohistochemistry for NK-1R,p EGFR,Cox-2,and VDR.Pictures of representative areas of each tissues diagnosis were taken and scored by three observers using a4-point scale that assessed intensity of staining.Tissues with CAC were further analyzed by photographing representative areas of IBD and the different grades of dysplasia,in addition to the areas of cancer,within each tissue.Differences in the average age between the five patient groups were assessed with one-way analysis of variance and Tukey-Kramer multiple comparisons test.The mean scores for normal tissues and tissues with IBD,dysplasia,CRC,and CAC were calculatedand statistically compared using one-way analysis of variance and Dunnett’s multiple comparisons test.Correlations between protein expression patterns were analyzed with the Pearson’s product-moment correlation coefficient.Data are presented as mean±SE.RESULTS:On average,patients with IBD were younger(34.60±5.81)than normal(63.20±6.13,P0.01),sporadic dysplasia(68.80±4.42,P0.01),sporadic cancer(74.80±4.91,P0.001),and CAC(57.50±5.11,P0.05)patients.NK-1R in cancer tissue(sporadic CRC,1.73±0.34;CAC,1.57±0.53)and sporadic dysplasia(2.00±0.45)were higher than in normal tissues(0.73±0.19).p EGFR was significantly increased in sporadic CRC(1.53±0.43)and CAC(2.25±0.47)when compared to normal tissue(0.07±0.25,P0.05,P0.001,respectively).Cox-2 was significantly increased in sporadic colorectal cancer(2.20±0.23 vs 0.80±0.37 for normal tissues,P0.05).In comparison to normal(2.80±0.13)and CAC(2.50±0.33)tissues,VDR was significantly decreased in sporadic dysplasia(0.00±0.00,P0.001 vs normal,P0.001 vs CAC)and sporadic CRC(0.47±0.23,P0.001 vs normal,P0.001 vs CAC).VDR levels negatively correlated with NK-1R(r=-0.48)and p EGFR(r=-0.56)in normal,IBD,sporadic dysplasia and sporadic CRC tissue,but not in CAC.CONCLUSION:Immunohistochemical NK-1R and p EGFR positivity with VDR negativity can be used to identify areas of sporadic colorectal neoplasia.VDR immunoreactivity can distinguish CAC from sporadic cancer.     

Intestinal dendritic cells change in number in fulminant hepatic failure

AIM:To investigate the change in intestinal dendritic cell(DC)number in fulminant hepatic failure(FHF).METHODS:An animal model of FHF was created.Intestinal CD11b/c was detected by immunohistochemistry and Western blot.Quantitative real-time polymerase chain reaction(PCR)was used to detect intestinal integrin-αm RNA expression.Intestinal CD83,CD86,CD74,CD3 and AKT were detected by immunohistochemistry,Western blot and PCR.Phosphorylated-AKT(p-AKT)was detected by immunohistochemistry and Western blot.RESULTS:In the FHF group[D-galactosamine(D-Galn)+lipopolysaccharide(LPS)group],the mice began to die after 6 h;conversely,in the D-Galn and LPS groups,the activity of mice was poor,but there were no deaths.Immunohistochemistry results showed that in FHF,the expression of CD11b/c(7988400±385941vs 1102400±132273,P0.05),CD83(13875000±467493 vs 9257600±400364,P0.05),CD86(7988400±385941 vs 1102400±13227,P0.05)and CD74(11056000±431427 vs 4633400±267903,P0.05)was significantly increased compared with the normal saline(NS)group.Compared with the NS group,the protein expression of CD11b/c(5.4817±0.77 vs 1.4073±0.37,P0.05)and CD86(4.2673±0.69 vs 1.1379±0.42,P0.05)was significantly increased.Itg-α(1.1224±0.3 vs 0.4907±0.19,P0.05),CD83(3.6986±0.40 vs 1.0762±0.22,P0.05)and CD86(1.5801±0.32 vs 0.8846±0.10,P0.05)m RNA expression was increased significantly in the FHF group.At the protein level,expression of CD74in the FHF group(2.3513±0.52)was significantly increased compared with the NS group(1.1298±0.33),whereas in the LPS group(2.3891±0.47),the level of CD74 was the highest(P0.05).At the gene level,the relative expression of CD74 m RNA in the FHF group(1.5383±0.26)was also significantly increased in comparison to the NS group(0.7648±0.22;P0.05).CD3 expression was the highest in the FHF group(P0.05).In the FHF,LPS and D-Galn groups,the expression of AKT at the protein and m RNA levels was elevated compared with the NS group,but there wasno statistical significance(P0.05).The p-AKT protein expression in the FHF(1.54±0.06),LPS(1.56±0.05)and D-Galn(1.29±0.03)groups was higher than that in the NS group(1.07±0.03)(P0.05).CONCLUSION:In FHF,a large number of DCs mature,express CD86,and activate MHC classⅡmolecular pathways to induce a T cell response,and the AKT pathway is activated.     

High dose glargine alters the expression profiles of microRNAs in pancreatic cancer cells

AIM: To investigate the effect of high dose glargine on the expression profiles of microRNAs in human pancreatic cancer cells.METHODS: Real-time polymerase chain reaction array (RT-PCR) was applied to investigate miRNAs differentially expressed in Sw1990 cells treated with or without 100 IU/L glargine. Stem-loop RT-PCR was used to confirm the results of the array assay in Sw1990 and Panc-1 cells. The effects of miR-95 on cell growth, apoptosis, invasion and migration abilities were respectively examined by CCK8 assay, apoptosis assay, Matrigel invasion and migration assay in Sw1990 and Panc-1 cells. Nude mice xenograft models with Sw1990 cells were built to investigate pancreatic cancer growth in vivo after transfection by the lentivirus pGLV3-GFP- miR-95.RESULTS: Ten miRNAs were significantly up-regulated and 2 miRNAs down-regulated in glargine treated Sw1990 cells when compared with non-treated cells (2.48-fold changes on average, P < 0.01). miR-95, miR-134 and miR-34c-3p are the top three miRNAs regulated by glargine (3.65-fold, 2.67-fold and 2.60-fold changes respectively, P < 0.01) in Sw1990 cells. Stem-loop RT-PCR confirmed that high dose glargine up-regulated the expression of miR-95 and miR-134 in both Sw1990 and Panc-1 cells. The most obvious change is the apparent increase of miR-95. Forced expression of miR-95 significantly increased cell proliferation (Sw1990: 2.510 ± 0.129 vs 2.305 ± 0.187, P < 0.05; Panc-1: 2.439 ± 0.211 vs 2.264 ± 0.117, P < 0.05), invasion (Sw1990: 67.90 ± 12.33 vs 47.30 ± 5.89, P < 0.01; Panc-1: 37.80 ± 8.93 vs 30.20 ± 5.14, P < 0.01), migration (Sw1990: 101 ± 6.00 vs 51.20 ± 8.34, P < 0.01; Panc-1: 91.80 ± 9.22 vs 81.50 ± 7.47, P < 0.01) and inhibited cell apoptosis (Sw1990: 22.05% ± 1.92% vs 40.32% ± 1.93%, P < 0.05; Panc-1: 20.17% ± 0.85% vs 45.60% ± 1.43%, P < 0.05) when compared with paired negative controls, whereas knockdown of miR-95 obtained the opposite effect. Nude mice xenograft models confirmed that miR-95 promoted the growth of pancreatic cancer in vivo when compared with negative control (tumor volume: 373.82 ± 23.67 mL vs 219.69 ± 17.82 mL, P < 0.05).CONCLUSION: These observations suggested that modulation of miRNA expression may be an important mechanism underlying the biological effects of glargine.     

Expression profile of polyunsaturated fatty acids in colorectal cancer

AIM:To investigate the relationship between the metabolism of polyunsaturated fatty acids(PUFAs)andtumor-associated factors for predicting the outcome of colorectal carcinoma(CRC)in Chinese patients.METHODS:Fresh-frozen malignant and normal tissues from 82 Chinese patients with CRC were analyzed for PUFA composition using gas-liquid chromatography.The levels of vascular endothelial growth factor(VEGF),cyclooxygenase-2(COX-2),prostaglandin E2 and platelet-derived growth factor(PDGF)were measured by enzyme-linked immunosorbent assay,and the levels of VEGF,p53 and Ki-67 were measured by immunohistochemistry.RESULTS:In malignant tissue,compared with normal tissue,the levels of totalω-6 PUFAs(24.64%±3.41%vs 26.77%±3.37%,P=0.00)and linoleic acid(LA)(15.46%±3.51%vs 18.30%±2.83%,P0.01)were lower,whereas the levels of totalω-3 PUFAs(1.58%±0.74%vs 1.35%±0.60%,P0.01)and dihomo-gamma-linolenic acid(DGLA)(1.32%±0.69%vs 0.85%±0.29%,P0.01)were significantly higher.The ratios of arachidonic acid(AA)/LA(0.53±0.22 vs0.42±0.19,P0.01)and AA/totalω-6 PUFAs(0.31±0.09 vs 0.27±0.10,P0.01)were also significantly higher in malignant tissue.The levels of PDGF(353.10±148.85 pg/m L vs 286.09±104.91 pg/m L,P0.01),COX-2(125.21±70.29 ng/m L vs 67.06±42.22 ng/m L,P0.01)and VEGF(357.11±128.76 pg/m L vs211.38±99.47 pg/m L,P0.01)were also higher in malignant tissue compared to normal tissue.COX-2was inversely correlated with LA(R=-0.3244,P0.05)and positively correlated with AA/totalω-6 PUFAs(R=0.3083,P0.05)and AA/LA(R=0.3001,P0.05).The tissue level of LA was highest in poorly differentiated tumors(19.9%±6.3%,P0.05),while the ratio of AA/ω-3 PUFAs was lowest in these tumors(10.8±2.6,P0.05).In VEGF-positive tumors,the level of LA was higher(16.2%±3.7%vs 13.9%±2.7%,P0.01),while the AA/ω-3PUFA,AA/ω-6 PUFA,and AA/LA ratios were lower than in VEGF-negativetumors(5.0±1.8 vs 6.7±3.3,0.30±0.09 vs 0.34±0.09,0.50±0.21 vs 0.61±0.21,P0.01).CONCLUSION:The metabolism of PUFAs may playan important role in the evolution of inflammationdriven tumorigenesis in CRC and may be considered apotential marker for prognosis.     

Helicobacter pylori and serum kynurenine-tryptophan ratio in patients with colorectal cancer

AIM: To evaluate how Helicobacter pylori(H. pylori) is able to evade the immune response and whether it enhances systemic immune tolerance against colorectal cancer.METHODS: This prospective randomized study involved 97 consecutive colorectal cancer patients and 108 cancer-free patients with extra-digestive diseases. Colorectal cancer and cancer-free patients were assigned into subgroups according to H. pylori Ig G seropositivity. Exposure to H. pylori was determined by Ig G seropositivity which was detected by enzyme linked immunoassay(ELISA). Serum neopterin levels were measured by ELISA. Serum tryptophan, kynurenine, and urinary biopterin concentrations were measured by high performance liquid chromatography. Serum nitrite levels were detected spectrophotometrically. Serum indoleamine 2,3-dioxygenase activity was estimated by the kynurenine to tryptophan ratio and by assessing the correlation between serum neopterin concentrations and the kynurenine to tryptophan ratio. The frequencies of increased serum kynurenine to tryptophan ratio of H. pylori seronegative and seropositive colorectal cancer subgroups were estimated by comparing them with the average kynurenine to tryptophan ratio of H. pylori seronegative tumor-free patients.RESULTS: Compared with respective controls, in both H. pylori seronegative and seropositive colorectal cancer patients, while serum tryptophan levels were decreased(controls vs patients; seronegative: 20.37 ± 0.89 μmol/L vs 15.71 ± 1.16 μmol/L, P < 0.05; seropositive: 20.71 ± 0.81 μmol/L vs 14.97 ± 0.79 μmol/L, P < 0.01) the kynurenine to tryptophan ratio was significantly increased(controls vs patients; seronegative: 52.85± 11.85 μmol/mmol vs 78.91 ± 8.68 μmol/mmol, P < 0.01, seropositive: 47.31 ± 5.93 μmol/mmol vs 109.65 ± 11.50 μmol/mmol, P < 0.01). Neopterin concentrations in cancer patients were significantly elevated compared with controls(P < 0.05). There was a significant correlation between serum neopterin levels and kynurenine/tryptophan in control and colorectal cancer patients groups(r s = 0.494, P = 0.0001 and r s= 0.293, P = 0.004, respectively). Serum nitrite levels of H. pylori seropositive cancer cases were significantly decreased compared with seropositive controls(controls vs patients; 26.04 ± 2.39 μmol/L vs 20.41 ± 1.48 μmol/L, P < 0.05) The decrease in the nitrite levels of H. pylori seropositive cancer patients may be attributed to excessive formation of peroxynitrite and other reactive nitrogen species.CONCLUSION: A significantly high kynurenine/tryptophan suggested that H. pylori may support the immune tolerance leading to cancer development, even without an apparent upper gastrointestinal tract disease.     

CD74 and macrophage migration inhibitory factor as therapeutic targets in gastric cancer

AIM: To investigate the relationship and molecular features of CD74/macrophage migration inhibitory factor (MIF)/Toll-like receptor 4 (TLR4) in gastric cancer.METHODS: CD74, MIF and TLR4 expression in the paraffin-embedded sections of gastric cancer from 120 patients were detected by immunohistochemical staining. Knock down of CD74 expression in gastric cancer cell line MKN-45 was performed by lentivirus transduction and detected by Western blotting. MKN-45 cell proliferation assay under the stimulants was measured by the cell counting kit 8 (CCK8) assay and MIF concentration in the culture medium was detected by enzyme-linked immunosorbent assay. Surface staining of CD74 in the MKN-45 cell line under the stimulation of lipopolysaccharide (LPS) was measured by flow cytometry. MIF, CD74 and TLR4 co-localization in the MKN-45 cell line was performed by the immunoprecipitation.RESULTS: CD74, MIF and TLR4 were found to be expressed in gastric cancer and increased significantly in the advanced stage, and were also associated with lymph node metastasis. Correlation analysis revealed that CD74 was positively correlated with MIF (r = 0.2367, P < 0.01) and both proteins were also associated with TLR4 (r = 0.4414, r = 0.5001, respectively, P < 0.01). LPS can significantly promote MKN-45 cell proliferation (3.027 ± 0.388 vs 4.201 ± 0.092, P < 0.05), induce MIF production (54.333 ± 2.906 pg/mL vs 29.667 ± 3.180 pg/mL, P < 0.01) and cell surface expression of CD74 (75.6% ± 4.046% vs 9.4% ± 0.964%, P < 0.01) at LPS concentration of 1 μg/mL compared to medium control. Knockdown of CD74 or using anti-CD74 and MIF antagonist ISO-1 significantly reduced LPS-induced MKN-45 cell proliferation (4.201 ± 0.092 vs 3.337 ± 0.087, 4.534 ± 0.222 vs 3.368 ± 0.290, 4.058 ± 0.292 vs 2.934 ± 0.197, respectively, P < 0.01). MIF, CD74 and TLR4 could co-localize in the MKN-45 cell line.CONCLUSION: Upregulation of MIF, CD74 and TLR4 are associated with increasing clinical stage and provide an opportunity as novel gastric cancer chemoprevention and/or treatment strategy.     

I_κB kinase-beta inhibitor attenuates hepatic fibrosis in mice

AIM: To investigate the anti-fibrosis effect of IκB kinase-beta inhibitor (IKK2 inhibitor IMD0354) in liver fibrosis. METHODS: Twenty male C57BL6 mice were divided into four groups. Five high-fat fed mice were injected with lipopolysaccharide (LPS, 10 mg/kg) intraperitoneally and five high-fat fed mice were without LPS injection to build models of liver injury, and the intervention group (five mice) was injected intraperitoneally with IKK2 inhibitor (IMD 30 mg/kg for 14 d), while the remaining five mice rec...     

Protective effects of 5-methoxypsoralen against acetaminophen-induced hepatotoxicity in mice

AIM: To investigate the hepatic protective effects of 5-methoxypsoralen (5-MOP) and to learn if 5-MOP causes hepatotoxicity at protective doses.METHODS: C57BL/6J mice were administrated orally with 5-MOP at doses of 12.5, 25 and 50 mg/kg body weight respectively every morning for 4 d before given acetaminophen (APAP) subcutaneously at a dose of 500 mg/kg. The 5-MOP alone group was treated with 5-MOP orally at a dose of 50 mg/kg body weight for 4 d without APAP. Twenty-four hours after APAP administration, blood samples of mice were analyzed for serum enzyme alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH) levels, and malondialdehyde (MDA), reduced glutathione (GSH) and oxidized glutathione (GSSG) of liver tissues were measured and histopathologic changes of the liver were observed.RESULTS: Compared with the vehicle control group, the serum levels (IU/L) of ALT, AST and LDH were all increased significantly in APAP group (8355 ± 3940 vs 30 ± 21, P < 0.05; 6482 ± 4018 vs 146 ± 58, P < 0.05; 24627 ± 10975 vs 1504 ± 410, P < 0.05). Compared with APAP group, the serum ALT levels (IU/L) (1674 ± 1810 vs 8355 ± 3940, P < 0.05; 54 ± 39 vs 8355 ± 3940, P < 0.05; 19 ± 9 vs 8355 ± 3940, P < 0.05), AST levels (IU/L) (729 ± 685 vs 6482 ± 4108, P < 0.05; 187 ± 149 vs 6482 ± 4108, P < 0.05; 141 ± 12 vs 6482 ± 4108, P < 0.05) and LDH levels (IU/L) (7220 ± 6317 vs 24 627 ± 10 975, P < 0.05; 1618 ± 719 vs 24 627 ± 10 975, P < 0.05; 1394 ± 469 vs 24 627 ± 10 975, P < 0.05) were all decreased drastically in the three-dosage 5-MOP pretreatment groups. Pretreatment of 5-MOP could attenuate histopathologic changes induced by APAP, including hepatocellular necrosis and infiltration of inflammatory cells, and the effect was dose-dependent. MDA levels (nmol/mg) were decreased by 5-MOP in a dose-dependent manner (0.98 ± 0.45 vs 2.15 ± 1.07, P > 0.05; 0.59 ± 0.07 vs 2.15 ± 1.07, P < 0.05; 0.47 ± 0.06 vs 2.15 ± 1.07, P < 0.05). The pretreatment of 5-MOP could also increase the GSH/GSSG ratio (3.834 ± 0.340 vs 3.306 ± 0.282, P > 0.05; 5.330 ± 0.421 vs 3.306 ± 0.282, P < 0.05; 6.180 ± 0.212 vs 3.306 ± 0.282, P < 0.05). In the group treated with 5-MOP but without APAP, the serum enzyme levels, the liver histopathologic manifestation, and the values of MDA and GSH/GSSG ratio were all normal.CONCLUSION: 5-MOP can effectively protect C57BL/6J mice from APAP-induced hepatotoxicity and possesses an antioxidative activity, and does not cause liver injury at the protective doses.     

Protective role of hydrogen-rich water on aspirin-induced gastric mucosal damage in rats

AIM: To investigate the role of the hydrogen-rich water(HRW) in the prevention of aspirin-induced gastric mucosal injury in rats. METHODS: Forty male rats were allocated into four groups: normal control group, HRW group, aspirin group, and HRW plus aspirin group. The protective efficacy was tested by determining the gastric mucosal damage score. Malondialdehyde(MDA), superoxide dismutase(SOD), myeloperoxidase(MPO), interleukin(IL)-06 and tumor necrosis factor(TNF)-α in gastric tissues were evaluated. The serum levels of IL-1β and TNF-α were also detected. Histopathology of gastric tissues and localization of Cyclooxygenase 2(COX-2) were detected using hematoxylin and eosin staining and immunohistochemistry, respectively. RESULTS: Pretreatment with HRW obviously reduced aspirin-induced gastric damage scores(4.04 ± 0.492 vs 2.10 ± 0.437, P < 0.05). The oxidative stress levels of MDA and MPO in the gastric tissues increased significantly in the aspirin-treated group compared with the HRW group(2.43 ± 0.145 vs 1.79 ± 0.116 nmol/mg prot, P < 0.05 and 2.53 ± 0.238 vs 1.40 ± 0.208 U/g tissue, P < 0.05, respectively). HRW could obviously elevated the SOD levels in the gastric tissues(37.94 ± 8.44 vs 59.55 ± 9.02 nmol/mg prot, P < 0.05). Pretreatment with HRW significantly reduced IL-06 and TNF-α in the gastric tissues(46.65 ± 5.50 vs 32.15 ± 4.83 pg/mg, P < 0.05 and 1305.08 ± 101.23 vs 855.96 ± 93.22 pg/mg, P < 0.05), and IL-1β and TNF-α in the serum(505.38 ± 32.97 vs 343.37 ± 25.09 pg/mL, P < 0.05 and 264.53 ± 28.63 vs 114.96 ± 21.79 pg/mL, P < 0.05) compared to treatment with aspirin alone. HRW could significantly decrease the COX-2 expression in the gastric tissues(staining score: 8.4 ± 2.1 vs 2.9 ± 1.5, P < 0.05). CONCLUSION: HRW pretreatment alleviated the aspirin-induced gastric lesions by inhibiting the oxidative stress, inflammatory reaction and reducing the COX-2 in the gastric tissues.     

Effects of metoclopramide on gastrointestinal myoelectric activity in rats

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Melittin induces human gastric cancer cell apoptosis via activation of mitochondrial pathway

AIM: To investigate the apoptotic effects of melittin on SGC-7901 cells via activation of the mitochondrial signaling pathway in vitro.METHODS: SGC-7901 cells were stimulated by melittin, and its effect on proliferation and apoptosis of was investigated by methyl thiazolyl tetrazolium assay, morphologic structure with transmission electron microscopy, annexin-V/propidium iodide double-staining assay, measuring mitochondrial membrane potential(MMP) levels, and analyzing reactive oxygen species(ROS) concentrations were analyzed by flow cytometry. Cytochrome C(Cyt C), apoptosis-inducing factor(AIF), endonuclease G(Endo G), second mitochondria-derived activator of caspases(Smac)/direct IAP binding protein with low isoelectric point(Diablo), and FAS were analyzed by western blot. The expression of caspase-3 and caspase-8 was measured using activity assay kits.RESULTS: Melittin was incubated at 1.0, 2.0, 4.0, or 6.0 μg/m L for 1, 2, 4, 6, or 8 h and showed a timeand concentration-dependent inhibition of SGC-7901 cell growth. Melittin induced SGC-7901 cell apoptosis, which was confirmed by typical morphological changes. Treatment with 4 μg/m L melittin induced early apoptosis of SGC-7901 cells, and the early apoptosis rates were 39.97% ± 3.19%, 59.27% ± 3.94%, and 71.50% ± 2.87% vs 32.63% ± 2.75% for 1, 2, and 4 h vs 0 h(n = 3, P 0.05); the ROS levels were 616.53% ± 79.78%, 974.81% ± 102.40%, and 1330.94% ± 93.09% vs 603.74% ± 71.99%(n = 3, P 0.05); the MMP values were 2.07 ± 0.05, 1.78 ± 0.29, and 1.16 ± 0.25 vs 2.55 ± 0.42(n = 3, P 0.05); caspase-3 activity was significantly higher compared to the control(5492.3 ± 321.1, 6562.0 ± 381.3, and 8695.7 ± 449.1 vs 2330.0 ± 121.9), but the caspase activity of the non-tumor cell line L-O2 was not different from that of the control. With the addition of the caspase-3 inhibitor(Ac-DEVD-CHO), caspase-3 activity was significantly decreased compared to the control group(1067.0 ± 132.5 U/g vs 8695.7 ± 449.1 U/g). The expression of the Cyt C, Endo G, and AIF proteins in SGC-7901 cells was significantly higher than those in the control(P 0.05), while the expression of the Smac/Diablo protein was significantly lower than the control group after melittin exposure(P 0.01). Ac-DEVD-CHO did not, however, have any effect on the expression of caspase-8 and FAS in the SGC-7901 cells.CONCLUSION: Melittin can induce apoptosis of human gastric cancer(GC) cells through the mitochondria pathways, and it may be a potent agent in the treatment of human GC.     

Changes in the colon microbiota and intestinal cytokine gene expression following minimal intestinal surgery

AIM: To investigate the impact of minor abdominal surgery on the caecal microbial population and on markers of gut inflammation.METHODS: Four week old piglets were randomly allocated to a no-surgery "control" group(n = 6) or a "transection surgery" group(n = 5).During the transection surgery procedure, a conventional midline incision of the lower abdominal wall was made and the small intestine was transected at a site 225 cm proximal to the ileocaecal valve, a 2 cm segment was removed and the intestine was re-anastomosed.Piglets received a polymeric infant formula diet throughout the study period and were sacrificed at two weeks post-surgery.Clinical outcomes including weight, stool consistency and presence of stool fat globules were monitored.High throughput DNA sequencing of colonic content was used to detect surgery-relateddisturbances in microbial composition at phylum, family and genus level.Diversity and richness estimates were calculated for the control and minor surgery groups.As disturbances in the gut microbial community are linked to inflammation we compared the gene expression of key inflammatory cytokines(TNF, IL1 B, IL18, IL12, IL8, IL6 and IL10) in ileum, terminal ileum and colon mucosal extracts obtained from control and abdominal surgery groups at two weeks post-surgery.RESULTS: Changes in the relative abundance of bacterial species at family and genus level were confined to bacterial members of the Proteobacteria and Bacteroidetes phyla.Family level compositional shifts included a reduction in the relative abundance of Enterobacteriaceae(22.95 ± 5.27 vs 2.07 ± 0.72, P 0.01), Bacteroidaceae(2.54 ± 0.56 vs 0.86 ± 0.43, P 0.05) and Rhodospirillaceae(0.40 ± 0.14 vs 0.00 ± 0.00, P 0.05) following transection surgery.Similarly, at the genus level, changes associated with transection surgery were restricted to members of the Proteobacteria and Bacteroidetes phyla and included decreased relative abundance of Enterobacteriaceae(29.20 ± 6.74 vs 2.88 ± 1.08, P 0.01), Alistipes(4.82 ± 1.73 vs 0.18 ± 0.13, P 0.05) and Thalassospira(0.53 ± 0.19 vs 0.00 ± 0.00, P 0.05).Surgeryassociated microbial dysbiosis was accompanied by increased gene expression of markers of inflammation.Within the ileum IL6 expression was decreased(4.46 ± 1.60 vs 0.24 ± 0.06, P 0.05) following transection surgery.In the terminal ileum, gene expression of TNF was decreased(1.51 ± 0.13 vs 0.80 ± 0.16, P 0.01) and IL18(1.21 ± 0.18 vs 2.13 ± 0.24, P 0.01), IL12(1.04 ± 0.16 vs 1.82 ± 0.32, P 0.05) and IL10(1.04 ± 0.06 vs 1.43 ± 0.09, P 0.01) gene expression increased following transection surgery.Within the colon, IL12(0.72 ± 0.13 vs 1.78 ± 0.28, P 0.01) and IL10(0.98 ± 0.02 vs 1.95 ± 0.14, P 0.01) gene expression were increased following transection surgery.CONCLUSION: This study suggests that minor abdominal surgery in infants, results in long-term alteration of the colonic microbial composition and persistent gastrointestinal inflammation.     

Xiaotan Tongfu granules contribute to the prevention of stress ulcers

AIM:To investigate the efficacy and potential mechanism of Xiaotan Tongfu granules(XTTF)in stress ulcers.METHODS:One hundred sixty rats were randomly divided into 4 groups(n=10)as follows:the model group(MP group),the control group(CP group),the ranitidine group(RP group)and the XTTF granule group(XP group).Rats in the MP group received no drugs,rats in the CP group received 0.2 mL of a 0.9%sodium chloride solution via oral gavage,and rats in the RP and XP groups received the same volume of ranitidine(50 mg/kg)or XTTF granule(4.9 g/kg).The cold-restraint stress model was applied to induce stress ulcers after 7 consecutive days of drug administration.Afterwards,rats were sacrificed at 0,3,6 and24 h.Gastric pH was measured by a precise pH meter;gastric emptying rate(GER)was measured by using a methylcellulose test meal;myeloperoxidase activity(MPO),macrophage migration inhibitory factor(MIF),proliferating cell nuclear antigen(PCNA),and heat shock protein 70(HSP70)were measured by immunohistochemical staining;and mucosal cell apoptosis was measured by transferase dUTP nick end labeling.RESULTS:In the cold-restraint stress model,the development of stress ulcers peaked at 3 h and basically regressed after 24 h.Gastric lesions were significantly different in the RP and XP groups at each time point.Interestingly,although this index was much lower in the RP group than in the XP group immediately following stress induction(7.00±1.10 vs 10.00±1.79,P<0.05.Concerning gastric pH,between the RP and XP groups,we detected a statistically significant difference immediately after stress induction(0 h:4.56±0.47 vs 3.34±0.28,P<0.05)but not at any of the subsequent time points.For GER,compared to the RP group,GER was remarkably elevated in the XP group because a statistically significant difference was detected(3 h:46.84±2.70 vs 61.16±5.12,P<0.05;6 h:60.96±6.71 vs 73.41±6.16,P<0.05;24 h:77.47±3.17 vs 91.31±4.34,P<0.05).With respect to MPO and MIF,comparisons between the RP and XP groups revealed statisticall     

Effects of hexahydrocurcumin in combination with 5-fluorouracil on dimethylhydrazine-induced colon cancer in rats

AIM: To investigate the effects of hexahydrocurcumin (HHC), and its combination with 5-fluorouracil (5-FU) on dimethylhydrazine (DMH)-induced colon cancer in rats.METHODS: Male Wistar rats weighing 100-120 g were used as subject models. Aberrant crypt foci (ACF), early preneoplastic lesions of colon cancer, were induced by subcutaneous injection of DHM (40 mg/kg) twice a week for two weeks. After the first DMH injection, rats were treated daily with vehicle (n = 12), curcumin (CUR) (50 mg/kg) (n = 12), HHC (50 mg/kg) orally (n = 12), and treated weekly with an intraperitoneal injection of 5-FU (50 mg/kg) (n = 12), or a combination of 5-FU plus CUR (n = 12) and HHC (n = 12) at the same dosage(s) for 16 wk. The total number of ACF and large ACF were assessed. Cyclooxygenase (COX)-1 and COX-2 expression were detected by immunohistochemistry in colon tissues. The quantitative data of both COX-1 and COX-2 expression were presented as the percentage of number of positive-stained cells to the total number of cells counted. Apoptotic cells in colon tissues were also visualized using the dUTP-biotin nick end labeling method. Apoptotic index (AI) was determined as the percentage of labeled nuclei with respect to the total number of nuclei counted.RESULTS: The total number of ACF was highest in the DMH-vehicle group (1558.20 ± 17.37), however, the number of ACF was significantly reduced by all treatments, 5-FU (1231.20 ± 25.62 vs 1558.20 ± 17.37, P < 0.001), CUR (1284.20 ± 25.47 vs 1558.20 ± 17.37, P < 0.001), HHC (1086.80 ± 53.47 vs 1558.20 ± 17.37, P < 0.001), DMH-5-FU + CUR (880.20 ± 13.67 vs 1558.20 ± 17.37, P < 0.001) and DMH-5-FU + HHC (665.80 ± 16.64 vs 1558.20 ± 17.37, P < 0.001). Interestingly, the total number of ACF in the combined treatment groups, the DMH-5-FU + CUR group (880.20 ± 13.67 vs 1231.20 ± 25.62, P < 0.001; 880.20 ± 13.67 vs 1284.20 ± 25.47, P < 0.001) and the DMH-5-FU + HHC group (665.80 ± 16.64 vs 1231.20 ± 25.62, P < 0.001; 665.80 ± 16.64 vs 1086.80 ± 53.47, P < 0.001) were significantly reduced as compared to 5-FU or each treatment alone. Large ACF were also significantly reduced in all treatment groups, 5-FU (111.00 ± 7.88 vs 262.20 ± 10.18, P < 0.001), CUR (178.00 ± 7.33 vs 262.20 ± 10.18, P < 0.001), HHC (186.60 ± 21.51 vs 262.20 ± 10.18, P < 0.001), DMH-5-FU + CUR (122.00 ± 5.94 vs 262.20 ± 10.18, P < 0.001) and DMH-5-FU + HHC (119.00 ± 17.92 vs 262.20 ± 10.18, P < 0.001) when compared to the vehicle group. Furthermore, in the DMH-5-FU + CUR and DMH-5-FU + HHC groups the formation of large ACF was significantly reduced when compared to CUR (122.00 ± 5.94 vs 178.00 ± 7.33, P < 0.005) or HHC treatment alone (119.00 ± 17.92 vs 186.60 ± 21.51, P < 0.001), however, this reduction was not statistically different to 5-FU monotherapy (122.00 ± 5.94 vs 111.00 ± 7.88, P = 0.217; 119.00 ± 17.92 vs 111.00 ± 7.88, P = 0.619, respectively). The levels of COX-1 protein after all treatments were not different from normal rats. A marked increase in the expression of COX-2 protein was observed in the DMH-vehicle group. Over-expression of COX-2 was not significantly decreased by 5-FU treatment alone (95.79 ± 1.60 vs 100 ± 0.00, P = 0.198). However, over-expression of COX-2 was significantly suppressed by CUR (77.52 ± 1.68 vs 100 ± 0.00, P < 0.001), HHC (71.33 ± 3.01 vs 100 ± 0.00, P < 0.001), 5-FU + CUR (76.25 ± 3.32 vs 100 ± 0.00, P < 0.001) and 5-FU + HHC (68.48 ± 2.24 vs 100 ± 0.00, P < 0.001) in the treated groups compared to the vehicle group. Moreover, CUR (77.52 ± 1.68 vs 95.79 ± 1.60, P < 0.001), HHC (71.33 ± 3.01 vs 95.79 ± 1.60, P < 0.001), 5-FU + CUR treatments (76.25 ± 3.32 vs 95.79 ± 1.60, P < 0.001) and 5-FU + HHC (68.48 ± 2.24 vs 95.79 ± 1.60, P < 0.001) markedly decreased COX-2 protein expression more than 5-FU alone. Furthermore, the AI in all treated groups, 5-FU (38.86 ± 4.73 vs 23.56 ± 2.12, P = 0.038), CUR (41.78 ± 6.92 vs 23.56 ± 2.12, P < 0.001), HHC (41.06 ± 4.81 vs 23.56 ± 2.12, P < 0.001), 5-FU + CUR (49.05 ± 6.75 vs 23.56 ± 2.12, P < 0.001) and 5-FU + HHC (53.69 ± 8.59 vs 23.56 ± 2.12, P < 0.001) significantly increased when compared to the DMH-vehicle group. However, the AI in the combination treatments, 5-FU + CUR (49.05 ± 6.75 vs 41.78 ± 6.92, P = 0.192; 49.05 ± 6.75 vs 38.86 ± 4.73, P = 0.771) and 5-FU + HHC (53.69 ± 8.59 vs 41.06 ± 4.81, P = 0.379; 53.69 ± 8.59 vs 38.86 ± 4.73, P = 0.245) did not reach significant levels as compared with each treatment alone and 5-FU monotherapy, respectively.CONCLUSION: The combined effects of HHC with 5-FU exhibit a synergistic inhibition by decreasing ACF formation mediated by down-regulation of COX-2 expression.