OBJECTIVETo investigate the changes of miR-155 and its target genes in colitis-associated carcinogenesis.

METHODSColitis-associated colon cancer was induced by azoxymethane (AOM) and dextran sulfate sodium (DSS) in C57BL/6 mice. Mice of three different stages during the development of colon cancer were obtained, named AD1, AD2 and AD3, respectively. A control group of mice without any treatment and a DSS only group representing chronic inflammation without cancer were set up as well. Colon tissue was collected and expression of miR-155 in the colon tissues was measured by real-time fluorescent quantitative PCR. TargetScan and PicTar were used to predict potential target genes of miR-155, which were then preliminarily screened with our gene expression microarray database of AOM-DSS mouse model. Regular PCR was used to confirm the changes of the expression of these potential target genes in AOM-DSS mouse model.

RESULTSColitis-associated colon cancer was effectively induced by azoxymethane and dextran sulfate sodium in C57BL/6 mice. Histological examination revealed that the evolution process was sequentially from normal, mild dysplasia, moderate dysplasia, and severe dysplasia to adenocarcinoma in the AOM-DSS mouse model. The level of miR-155 was gradually elevated with the formation of colitis-associated colon cancer. There was no significant difference between the levels of miR-155 expression in the DSS group (0.005 6 ± 0.003 7) and control group (0.012 0 ± 0.005 1) (P > 0.05), but the level of miR-155 in the AD3 group (0.054 4 ± 0.027 0) was significantly higher than that of the DSS group (0.005 6 ± 0.003 7)(P < 0.01). No significant change of miR-155 expression was found in the DSS only group. The relative expression levels of miR-155 in the control group, DSS only group and AD3 group were 0.012 0 ± 0.005 1, 0.005 6 ± 0.003 7, 0.054 4 ± 0.027 0, respectively. Data analysis with the gene expression microarray showed that Tle4, Kcna1, Itk, Bcorl1, Cacna1c, Rspo2 and Foxo3 were potential target genes of miR-155 in the AOM-DSS mouse model. Changes of Kcna1 and Cacna1c in the AOM-DSS mouse model were validated to be consistent with the changes obtained with the gene expression microarray.

CONCLUSIONThe up-regulation of miR-155 is related to colitis-associated carcinogenesis, but is irrelevant to chronic inflammation in the mouse model.

Adenocarcinoma ; chemically induced ; genetics ; metabolism ; Animals ; Azoxymethane ; toxicity ; Carcinogens ; toxicity ; Cocarcinogenesis ; Colitis ; chemically induced ; genetics ; metabolism ; Colon ; metabolism ; Colonic Neoplasms ; chemically induced ; genetics ; metabolism ; Dextran Sulfate ; toxicity ; Gene Expression Profiling ; Male ; Mice ; Mice, Inbred C57BL ; MicroRNAs ; metabolism ; Precancerous Conditions ; chemically induced ; genetics ; metabolism ; Up-Regulation

Deregulation of G1 cyclins has been reported in several human and rodent tumors including colon cancer. To investigate the expression pattern of G1 cyclins in 1,2- dimethyl-hydrazine dihydrochloride (DMH)-induced rat colon carcinogenesis, we studied the expression of cyclin D1 and cyclin E by quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis and immunohistochemistry (IHC). The mRNA level of cyclin D1 was increased 1.2-fold in adenocarcinomas but not significantly in adenomas, when compared with normal rat colonic mucosa (p<0.05). The cyclin E mRNA level was increased 2.7-fold in adenomas and 3.3-fold in adenocarcinomas (p<0.05). The PCNA mRNA level was also increased 1.9-fold in adenomas and 1.8-fold in adenocarcinomas (p<0.05). Immunohistochemical staining revealed exclusive nuclear staining of the neoplastic cells for cyclin D1, cyclin E and PCNA. Cyclin D1 expression was detected in 56.3% of the adenomas and in 61.5% of the adenocarcinomas examined, whereas cyclin E expression was detected in 87.5% of the adenomas and in 92.3% of the adenocarcinomas. Overall, cyclin D1, cyclin E and PCNA expression was significantly increased at both the mRNA and protein levels in normal colonic mucosa, adenomas and adenocarcinomas, but there was no significant difference in the degree of expression of these genes in adenomas and adenocarcinomas. Our results indicate that the overexpression of cyclin D1 and cyclin E may play an important role during the multistage process of rat colon carcinogenesis, at a relatively early stage, and may disturb cell-cycle control in benign adenomas, and thereafter, participate in tumor progression.
1,2-Dimethylhydrazine/toxicity ; Adenocarcinoma/*chemically induced/metabolism ; Adenoma/*chemically induced/metabolism ; Animals ; Carcinogens/toxicity ; Cell Cycle/drug effects/physiology ; Colon/metabolism ; Colonic Neoplasms/*chemically induced/metabolism ; Cyclin D1/*biosynthesis/genetics ; Cyclin E/*biosynthesis/genetics ; Gene Expression Regulation, Neoplastic ; Immunohistochemistry ; Male ; Proliferating Cell Nuclear Antigen/biosynthesis/genetics ; RNA, Messenger/metabolism ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction

To study the chemo-preventive effect of the supercritical extracts from Angelica sinensis (SFE-AS) on induced colorectal carcinoma in mice by using the AOM/DSS-induced male mice colorectal carcinoma model, and discuss its possible action mechanism. Male Balb/c mice were subcutaneously injected with single dose of azoxymethane (AOM, 10 mg x kg(-1) body weight). One week later, they were given 2% dextran sodium sulfate (DSS) in drinking water for 7 days to induce colorectal carcinoma. Each drug group was orally administered with supercritical extracts from Angelica sinensis at 15, 30, 60 mg x kg(-1) until the 17th week. The tumor incidence rate of the SFE-AS group, mice tumor-bearing quantity and tumor-bearing volume of the SFE-AS group were lower than that of the AOM/DSS model control group, which may be related with the significant reduction of PCNA, COX-2, iNOS in the AOM/DSS-induced mouse colorectal carcinoma model associated with inflammation by SFE-AS. According to the results of this study, SFE-AS showed an intervention effect in the incidence and development of AOM/DSS-induced mouse colorectal carcinoma associated with inflammation, and could be further used in chemo-preventive studies on human colorectal carcinoma.
Angelica sinensis ; chemistry ; Animals ; Azoxymethane ; adverse effects ; Colonic Neoplasms ; chemically induced ; genetics ; immunology ; prevention & control ; Colorectal Neoplasms ; chemically induced ; genetics ; immunology ; prevention & control ; Cyclooxygenase 2 ; genetics ; metabolism ; Dextran Sulfate ; adverse effects ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Proliferating Cell Nuclear Antigen ; genetics ; immunology

OBJECTIVETo study the efficacy and safety of cetuximab combined with chemotherapy for patients with advanced colorectal cancer (ACRC) and unclear K-ras status.

METHODSClinical data of 102 ACRC patients, treated by cetuximab combined with chemotherapy in Sun Yat-sen Cancer Center from March 2005 to December 2008, were collected. The cumulative survival rate, objective response rate (ORR), disease control rate (DCR), progression free survival (PFS) of the cases were calculated. The difference in ORR, DCR, PFS and oval survival (OS) between the regimens used as first-line and non-first-line treatment, and between the regimens including oxaliplatin and irinotecan were compared.

RESULTSThe overall ORR of cetuximab plus chemotherapy was 43.1%, DCR 73.5%, median PFS 4.0 months, OS 28.5 months, and the 1-year, 3-year, and 5-year survival rate was 89.2%, 50.9% and 27.5%, respectively. The differences in ORR (50.0% vs. 40.0%, P = 0.344), DCR (78.1% vs. 72.9%, P = 0.571) and OS (51.0 months vs. 35.0 months, P = 0.396) between the regimens as first line and as non-first line treatment were not statistically significant. However, the PFS of the regimen as first-line was longer than that as non-first-line treatment (PFS 5.5 months vs. 3.0 months, P = 0.001). The differences in ORR (54.2% vs. 40.0%, P = 0.223), DCR (79.2% vs. 74.7%, P = 0.654), PFS (5.0 months vs. 3.0 months, P = 0.726) and OS (36.0 months vs. 40.0 months, P = 0.759) between cetuximab plus oxliplatin and irinotecan were not statistically significant. The most common side effects of cetuximab plus chemotherapy were acneiform eruption (80.4%, grade 3-4 in 9.8%), neutropenia (66.7%, grade 3-4 in 18.6%), and diarrhea (19.6%, grade 3-4 in 5.9%). No treatment-related death was recorded.

CONCLUSIONPatients with advanced colorectal cancer and unclear K-ras treated by cetuximab combined with chemotherapy have good ORR and OS, and the regimen is safe with less adverse events for them. There is no significant difference between the efficacies of regimens as first line and as non-first line treatment, and between cetuximab plus oxliplatin and cetuximab plus irinotecan regimens.

Acneiform Eruptions ; chemically induced ; Adenocarcinoma ; drug therapy ; metabolism ; pathology ; secondary ; surgery ; Adult ; Antibodies, Monoclonal ; adverse effects ; therapeutic use ; Antibodies, Monoclonal, Humanized ; Antineoplastic Agents ; adverse effects ; therapeutic use ; Antineoplastic Combined Chemotherapy Protocols ; adverse effects ; therapeutic use ; Camptothecin ; administration & dosage ; analogs & derivatives ; Cetuximab ; Colonic Neoplasms ; drug therapy ; metabolism ; pathology ; surgery ; Diarrhea ; chemically induced ; Disease-Free Survival ; Female ; Follow-Up Studies ; Humans ; Liver Neoplasms ; drug therapy ; secondary ; Lung Neoplasms ; drug therapy ; secondary ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Neutropenia ; chemically induced ; Organoplatinum Compounds ; administration & dosage ; Rectal Neoplasms ; drug therapy ; metabolism ; pathology ; surgery ; Remission Induction ; Survival Rate ; ras Proteins ; metabolism

Prebiotics modulate microbial composition and ensure a healthy gastrointestinal tract environment that can prevent colon cancer development. These natural dietary compounds are therefore potential chemopreventive agents. Thirty Sprague-Dawley rats (4 months old) were experimentally treated with procarcinogen dimethylhydrazine to induce colon cancer development. The rats were randomly assigned to three groups: a control group (CG), a group treated with dimethylhydrazine (DMH), and a group given DMH and inulin, a prebiotic (DMH+PRE). The effects of inulin on the activities of bacterial glycolytic enzymes, short-chain fatty acids, coliform and lactobacilli counts, cytokine levels, and cyclooxygenase-2 (COX-2) and transcription nuclear factor kappa beta (NFkappaB) immunoreactivity were measured. Inulin significantly decreased coliform counts (p < 0.01), increased lactobacilli counts (p < 0.001), and decreased the activity of beta-glucuronidase (p < 0.01). Butyric and propionic concentrations were decreased in the DMH group. Inulin increased its concentration that had been reduced by DMH. Inulin decreased the numbers of COX-2- and NFkappaB-positive cells in the tunica mucosae and tela submucosae of the colon. The expression of IL-2, TNFalpha, and IL-10 was also diminished. This 28-week study showed that dietary intake of inulin prevents preneoplastic changes and inflammation that promote colon cancer development.
Animals ; Bacterial Proteins/genetics/metabolism ; Colon/enzymology ; Colonic Neoplasms/chemically induced/*drug therapy/metabolism ; Colony Count, Microbial ; Cyclooxygenase 2/genetics/metabolism ; Cytokines/blood/genetics ; Diet ; Dietary Supplements/analysis ; Dimethylhydrazines/toxicity ; Enterobacteriaceae/drug effects/physiology ; Fatty Acids, Volatile/genetics/metabolism ; Female ; Gene Expression Regulation/drug effects ; Inulin/administration & dosage/*metabolism ; Lactobacillaceae/drug effects/physiology ; Male ; NF-kappa B/genetics/metabolism ; Prebiotics/*analysis ; Rats ; Rats, Sprague-Dawley

Triptolide, a diterpenoid triepoxide from the traditional Chinese medicinal herb Tripterygium wilfordii Hook. f., is a potential treatment for autoimmune diseases as well a possible anti-tumor agent. It inhibits proliferation of coloretal cancer cells in vitro and in vivo. In this study, its ability to block progress of colitis to colon cancer, and its molecular mechanism of action are investigated. A mouse model for colitis-induced colorectal cancer was used to test the effect of triptolide on cancer progression. Treatment of mice with triptolide decreased the incidence of colon cancer formation, and increased survival rate. Moreover, triptolide decreased the incidence of tumors in nude mice inoculated with cultured colon cancer cells dose-dependently. In vitro, triptolide inhibited the proliferation, migration and colony formation of colon cancer cells. Secretion of IL6 and levels of JAK1, IL6R and phosphorylated STAT3 were all reduced by triptolide treatment. Triptolide prohibited Rac1 activity and blocked cyclin D1 and CDK4 expression, leading to G1 arrest. Triptolide interrupted the IL6R-JAK/STAT pathway that is crucial for cell proliferation, survival, and inflammation. This suggests that triptolide might be a candidate for prevention of colitis induced colon cancer because it reduces inflammation and prevents tumor formation and development.
Animals ; Cell Transformation, Neoplastic/*drug effects ; Colitis/complications ; Colonic Neoplasms/chemically induced/*drug therapy/metabolism/pathology ; Dextran Sulfate/toxicity ; Dimethylhydrazines/toxicity ; Diterpenes/*administration & dosage ; Epoxy Compounds/administration & dosage ; Humans ; Interleukin-6/biosynthesis ; Janus Kinases/metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred ICR ; Mice, Nude ; Neoplasm Transplantation ; Phenanthrenes/*administration & dosage ; STAT3 Transcription Factor/metabolism ; Signal Transduction/*drug effects ; Tumor Burden/drug effects ; rac1 GTP-Binding Protein/*biosynthesis