OBJECTIVETo explore the chemopreventive effect of curcumin on DMH induced colorectal carcinogenesis and the underlining mechanism.

METHODSTotally 40 Wistar rats were divided into the model group and the curcumin group by random digit table, 20 in each group. Meanwhile, a normal control group was set up (n =10). A colorectal cancer model was induced by subcutaneously injecting 20 mg/kg DMH. The tumor incidence and the inhibition rate were calculated. The effect of curcumin on the expression of peroxisome proliferator-activated receptor gamma (PPARγ) in rat colon mucosal tissues was observed using immunohistochemistry and Western blot. HT 29 cell line were cultured and divided into a control group, the curcumin + GW9662 (2-chloro-5-nitro-N-4-phenylbenzamide) intervention group, and the curcumin group. The inhibition of different concentrations curcumin on HT29 cell line was detected using MTT. The expression of curcumin on PPARy was also detected using Western blot.

RESULTSThe tumor incidence was 80. 00% (12/15 cases) in the model group, obviously higher than that of the curcumin group (58. 82%, 10/17 cases, P <0. 05). The inhibition rate of curcumin on DMH induced colorected carcinoma reached 26. 46%. Compared with the normal control group, the expression of PPARγ protein was significantly increased in the curcumin group and the model group (P <0. 01). Compared with the model group at the same time point, the expression of PPARy protein was significantly enhanced in the curcumin group (P <0. 05). MTT analysis showed that curcumin could inhibit the proliferation of in vitro HT 29 cells in dose and time dependent manners. The expression of PPARy protein was significantly increased in the GW9662 group and the curcumin group, showing statistical difference when compared with the normal control group (P <0. 01). Compared with the GW9662 group, the expression of PPARγ protein was significantly increased in the curcumin group (P <0. 01).

CONCLUSIONCurcumin could inhibit DMH-induced rat colorectal carcinogenesis and the growth of in vitro cultured HT 29 cell line, which might be achieved by activating PPARy signal transduction pathway.

Anilides ; Animals ; Carcinogenesis ; Colorectal Neoplasms ; drug therapy ; metabolism ; Curcumin ; pharmacology ; therapeutic use ; PPAR gamma ; metabolism ; Rats ; Rats, Wistar ; Signal Transduction

Antineoplastic Agents ; therapeutic use ; Colorectal Neoplasms ; drug therapy ; genetics ; metabolism ; Genes, ras ; genetics ; Humans ; Lung Neoplasms ; drug therapy ; genetics ; metabolism ; Molecular Targeted Therapy ; methods ; Mutation ; Neoplasms ; drug therapy ; genetics ; metabolism ; Pancreatic Neoplasms ; drug therapy ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins p21(ras) ; Receptor, Epidermal Growth Factor ; drug effects ; metabolism ; Signal Transduction ; ras Proteins ; genetics ; metabolism

In recent years, the clinical treatment of colorectal cancer(CRC) has made great progress, but chemoresistance is still one of the main reasons for reducing the survival rate of patients with colorectal cancer. Therefore, ameliorating chemotherapy resis-tance is an urgent problem to be solved. The purpose of this study was to investigate the regulatory role and related molecular mechanisms of hydroxysafflor yellow A(HSYA) in colorectal cancer cell proliferation, migration, and 5-fluorouracil(5-FU) chemoresistance. In this study, HCT116 and HT-29 cells were used as research subjects. Firstly, methyl thiazolyl tetrazolium(MTT) assay and colony formation assay were used to detect and analyze the effect of HSYA on the proliferation of CRC cells. Secondly, the effect of HSYA on the cell cycle in CRC cells was analyzed by cell cycle assay. Furthermore, the effect of HSYA on the migration of CRC cells was analyzed by wound-healing assay and Transwell assay. Based on the above, the influences of HSYA on 5-FU chemoresistance of CRC cells and related molecular mechanisms were explored and analyzed. The results showed that HSYA significantly inhibited the proliferation and migration of CRC cells, and arrested the cell cycle in G_0/G_1 phase. In addition, HSYA significantly ameliorated the chemoresistance of CRC cells to 5-FU. The results of acridine orange staining and Western blot showed that the autophagy activity of CRC cells in the HSYA and 5-FU combined treatment group was significantly higher than that in the 5-FU single drug treatment group. As compared with the 5-FU single drug treatment group, the phosphorylation levels of protein kinase B(Akt) and mammalian target of rapamycin(mTOR) in the HSYA and 5-FU combined treatment group were significantly reduced, indicating that the Akt/mTOR signaling pathway in the combined treatment group was down-regulated in CRC cells. In conclusion, HSYA may upregulate autophagy activity through the Akt/mTOR signaling pathway, thereby inhibiting the proliferation and migration of CRC cells and ameliorating the chemoresistance to 5-FU.
Humans ; Proto-Oncogene Proteins c-akt/metabolism* ; Drug Resistance, Neoplasm ; Cell Line, Tumor ; TOR Serine-Threonine Kinases/metabolism* ; Fluorouracil/pharmacology* ; Cell Proliferation ; Autophagy ; Colorectal Neoplasms/drug therapy*

OBJECTIVETo investigate the association between expressions of HSP70, HSP90 and efficacy of chemotherapy in colorectal cancer patients with unresectable liver metastasis.

METHODSData of 52 colorectal cancer cases, whose primary colorectal focuses were resected but hepatic metastatic tumors were unresectable, were reviewed retrospectively. All the patients underwent FOLFOX4 regimen well. Immunohistochemistry assay was applied to determine the expressions of HSP70 and HSP90 in primary focus tissues. The number and size of hepatic metastatic tumors pre- and post-chemotherapy were compared by CT scanning.

RESULTSPartial remission(PR) rate was 33.3% in cases with up-regulated expression of HSP70, while 64.5% in cases with down-regulated expression of HSP70, whose difference was significant. PR rate was 50% in cases with up-regulated expression of HSP90, and 53.1% in the others with down-regulated expression of HSP90, whose difference was not significant.

CONCLUSIONSFOLFOX4 regimen has advantages in cases with lower HSP70 expression over those with higher HSP70 expression. HSP90 expression level is not associated with the efficacy of FOLFOX4 regimen.

Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Colorectal Neoplasms ; drug therapy ; metabolism ; pathology ; Female ; HSP70 Heat-Shock Proteins ; metabolism ; HSP90 Heat-Shock Proteins ; metabolism ; Humans ; Liver Neoplasms ; drug therapy ; metabolism ; secondary ; Male ; Middle Aged ; Prognosis ; Treatment Outcome

INTRODUCTIONColorectal cancer is the most common form of malignancy in Taiwan and the third leading cause of death from cancer, preceded only by lung and hepatic cancers. Colorectal cancer is typically treated by surgical intervention and/or chemotherapy and radiotherapy, if necessary. To date, 5-fluorouracil (5-FU) is the most commonly used anti-cancer chemotherapy drug. However, patients commonly experience resistance to the drug therefore limiting its efficiency. In this study, we measured the expression of rTSbeta in human colon cancer as a novel 5-FU resistance marker.

MATERIALS AND METHODSWe collected 172 colon cancer samples from 4 different hospitals (including 21 pairs of colon cancer biopsies and 151 pathologic slides of colon cancer). In vitro, we measured the cytotoxicity of 5-FU and 5-FU plus leucovorin in H630 and H630-1 colon cancer cell lines.

RESULTSThe results revealed that rTSbeta was expressed in 115 (66.9 %) pathology samples and that tumour expression was higher than in corresponding normal tissue. Survival rates of up to 5 years following treatment was significantly higher for patients without rTSbeta expression than for those with rTSbeta expression (P = 0.0023). In vitro, H630-1 (with rTSbeta overexpression) had significantly higher IC50 of 5-FU than did H630. IC50 of 5-FU decreased when leucovorin was added.

CONCLUSIONSResults indicate a close relationship between rTSbeta expression and resistance to the drug 5-FU in human colorectal cancer. These results provide further evidence for rTSbeta expression as a novel 5-FU resistance marker of colorectal cancer.

Biomarkers ; Cell Line, Tumor ; drug effects ; Colorectal Neoplasms ; drug therapy ; Cytological Techniques ; Drug Resistance, Neoplasm ; physiology ; Fluorouracil ; pharmacology ; therapeutic use ; Humans ; In Vitro Techniques ; Taiwan ; Thymidylate Synthase ; genetics ; metabolism

Abnormal glycosylation due to dysregulated glycosyltransferases and glycosidases is a key phenomenon of many malignancies, including colorectal cancer (CRC). In particular, increased ST6 Gal I (beta-galactoside alpha 2, 6 sialyltransferase) and subsequently elevated levels of cell-surface alpha 2, 6-linked sialic acids have been associated with metastasis and therapeutic failure in CRC. As many CRC patients experience metastasis to the liver or lung and fail to respond to curative therapies, intensive research efforts have sought to identify the molecular changes underlying CRC metastasis. ST6 Gal I has been shown to facilitate CRC metastasis, and we believe that additional investigations into the involvement of ST6 Gal I in CRC could facilitate the development of new diagnostic and therapeutic targets. This review summarizes how ST6 Gal I has been implicated in the altered expression of sialylated glycoproteins, which have been linked to CRC metastasis, radioresistance, and chemoresistance.
Antigens, CD/*metabolism ; Colorectal Neoplasms/*metabolism/pathology/*therapy ; Drug Resistance, Neoplasm ; Glycoproteins/*metabolism ; Humans ; Liver Neoplasms/secondary ; Lung Neoplasms/secondary ; Radiation Tolerance ; Receptor, Epidermal Growth Factor/metabolism ; Sialic Acids/*metabolism ; Sialyltransferases/*metabolism

The aim of the present study was to accurately evaluate the association of Sox2 expression with the survival of patients with digestive tract cancers. Relevant literatures were identified by comprehensively searching databases including the Pubmed, Embase, CBMdisc, and Wanfang (up to October 2014). A meta-analysis was performed to clarify the association between Sox2 expression and overall survival or clinicopathological parameters of patients with digestive tract cancers (esophageal, gastric, and colorectal cancers). The results showed a significant association between high Sox2 expression and poor overall survival in patients with digestive tract carcinomas (HR=1.55, 95% CI=1.04-2.31), especially for patients with esophageal cancer (HR=2.04, 95%CI=1.30-3.22), colorectal cancer (HR=1.40, 95% CI=1.04-1.89), and digestive tract adenocarcinoma (HR=1.80, 95% CI=1.12-2.89), for Europeans (HR=1.98, 95% CI=1.44-2.71) or patients who did not receive neoadjuvant treatment (HR=1.73, 95% CI=1.10-2.72). Furthermore, Sox2 over-expression was highly correlated with vascular invasion (OR=1.86, 95% CI=1.25-2.77) and poor differentiation (OR=1.88, 95% CI=1.14-3.08), especially in esophageal and colorectal cancers. In conclusion, Sox2 expression may serve as a novel prognostic factor for patients with digestive tract cancers. Over-expression of Sox2 that is correlated with vascular invasion and poor differentiation suggests poor outcomes of patients with digestive tract cancers.
Antineoplastic Agents ; therapeutic use ; Biomarkers, Tumor ; genetics ; metabolism ; Colorectal Neoplasms ; diagnosis ; drug therapy ; mortality ; pathology ; Esophageal Neoplasms ; diagnosis ; drug therapy ; mortality ; pathology ; Gastrointestinal Tract ; metabolism ; pathology ; Gene Expression ; Humans ; Neoadjuvant Therapy ; methods ; Neoplasm Grading ; Neoplasms, Vascular Tissue ; diagnosis ; drug therapy ; mortality ; secondary ; Prognosis ; SOXB1 Transcription Factors ; genetics ; metabolism ; Stomach Neoplasms ; diagnosis ; drug therapy ; mortality ; pathology ; Survival Analysis

OBJECTIVETo investigate the effects of lentivirus-mediated RNA interference (RNAi) targeting a proliferation-inducing ligand (APRIL) on the chemosensitivity to 5-FU of colorectal cancer cell line LoVo.

METHODSThe lentiviral vector siRNA-APRIL was constructed and verified by PCR and DNA sequencing. LoVo cells were transfected with siRNA-APRIL plasmid, non-targeting siRNA plasmid, or empty plasmid. Forty-eight hours after the transfection, the cells were examined for APRIL expression using Western blot. Seventy-two hours after treatment with 10 µg/ml 5-FU, flow cytometry was used to detect the cell apoptosis and cell cycle changes. The cell growth inhibition rate following 5-FU exposure was detected by MTT assay.

RESULTSPCR analysis and DNA sequencing demonstrated that the RNAi sequence targeting APRIL gene was successfully inserted into the lentiviral vector. siRNA-APRIL transfection resulted in obviously reduced expression of APRIL in LoVo cells. After 5-FU exposure, the apoptosis rate of siRNA-APRIL-transfected cells were increased to (21.12∓3.35)%, significantly higher than that in cells transfected with the non-targeting plasmid or the empty plasmid [(13.06∓1.92)% and (12.28∓1.79)%, respectively, P<0.01]; the cell number in G0/G1 phase increased while that in G2/M phase decreased in siRNA-APRIL-transfected cells. The growth inhibition rate in siRNA-APRIL group was (59.67∓5.03)%, significantly higher than that in the other two groups [(42.33∓4.16)% and (39.67∓4.73)%, respectively, P<0.01].

CONCLUSIONLentivirus-mediated RNAi targeting APRIL can effectively suppress the expression of APRIL in LoVo cells and enhance the chemosensitivity of the cells to 5-FU.

Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Colorectal Neoplasms ; drug therapy ; metabolism ; pathology ; Drug Resistance, Neoplasm ; Fluorouracil ; pharmacology ; Humans ; Lentivirus ; genetics ; RNA Interference ; Tumor Necrosis Factor Ligand Superfamily Member 13 ; genetics ; metabolism

BRAF is one of the most important pro-oncogenes, which is mutated in approximately 8% of human tumors. The most common BRAF mutation is a valine-to-glutamate transition (V600E) that is expressed primarily in melanoma, colorectal cancer and thyroid carcinoma. MEK/ERK is constitutively activated in the cells expressing BRAFV600E, leading to tumor development, invasion, and metastasis. Therefore, BRAFV600E is a therapeutic target for melanoma and some other BRAFV600E tumors. Vemurafenib, a BRAFV600E inhibitor, which was approved by FDA for the treatment of late-stage melanoma in 2011, produces improved rates of overall and progression-free survival in patients with the BRAFV600E mutation, making a dramatic breakthrough in melanoma treatment. Vemurafenib is also an individual target drug based on genetic diagnosis. However, its therapeutic success is limited by the emergence of drug resistance. Therefore, it is important to explore the mechanisms underlying the resistance for developing new inhibitor drugs and for preventing or delaying the resistance evolution to BRAF inhibitor drugs. In this review, we described the role of BRAFV600E as an anti-tumor drug target and the development of BRAF inhibitors. We also discussed the mechanisms leading to resistance of BRAFV600E inhibitors. Furthermore, therapeutic strategies that might be employed to overcome acquired resistance were proposed.
Animals ; Antineoplastic Agents ; therapeutic use ; Colorectal Neoplasms ; drug therapy ; genetics ; metabolism ; Drug Delivery Systems ; Drug Resistance, Neoplasm ; Humans ; Imidazoles ; therapeutic use ; Indoles ; therapeutic use ; Melanoma ; drug therapy ; genetics ; metabolism ; Mitogen-Activated Protein Kinase Kinases ; metabolism ; Mutation ; Oximes ; therapeutic use ; Proto-Oncogene Proteins B-raf ; antagonists & inhibitors ; genetics ; metabolism ; Sulfonamides ; therapeutic use ; Thyroid Neoplasms ; drug therapy ; genetics ; metabolism

PURPOSE: Dihydropyrimidine dehydrogenase (DPD) is a rate-limiting enzyme in 5-FU catabolism, so the enzymatic activity of DPD reflects the 5-FU response. Moreover, recent studies have revealed that microsatellite instability (MSI) status correlates well with the prognosis and the 5-FU chemosensitivity in colorectal cancer (CRC). This study aimed to determine whether DPD mRNA expression is related with the MSI status of primary CRC as a prognostic predictor. METHODS: Tumor samples and adjacent normal colonic mucosal tissues were collected from 59 patients. DPD mRNA expression was calculated by using the real-time RT-PCR method. The MSI status was examined by using multiplex fluorescent PCR with five reference markers. The results of DPD mRNA expression and MSI status were compared with the clinicopathologic variables and with each other. RESULTS: The mean age of the 59 patients was 59 (range: 36~81) years. In 55 patients (93.2%), the colorectal cancers were histologically well or moderately differentiated. Forty-nine of the tumors (49, 83.1%) were located distal to the splenic flexure, and 46 patients (78%) had TNM stage II (n=17) or stage III (n=29) cancer. The DPD mRNA expression level was informative in all 59 cases. The median expression level was 2.5 (range: 0~67.33). There was no correlation between the DPD mRNA expression level and age, gender, location, or TNM stage. MSI status was informative in 43 cases (72.9%). Thirty-six cases (36, 83.7%) were microsatellite-stable (MSS), 4 cases (9.3%) showed low-level microsatellite instability (MSI-L), and 3 cases (7.0%) showed high-level microsatellite instability (MSI-H). Proximal CRC showed a higher proportion of MSI-H than distal CRC (25% vs. 2.9%, P=0.03). We could not find any correlation between the DPD mRNA expression level and the MSI status in tumor tissues (r=0.29, P=0.09). CONCLUSIONS: The expression level of DPD mRNA raried among the tumors studied. The relatively low frequency of MSI in distal CRC prohibits the use of MSI status as a predictor of 5-FU chemosensitivity. We suggest that a well-designed large-scale study would be helpful to confirm the relation between DPD mRNA expression and MSI status as a predictor of 5-FU chemosensitivity in CRC patients.
Colon ; Colon, Transverse ; Colorectal Neoplasms* ; Dihydrouracil Dehydrogenase (NADP)* ; Drug Therapy* ; Fluorouracil* ; Humans ; Metabolism ; Microsatellite Instability* ; Microsatellite Repeats* ; Mucous Membrane ; Polymerase Chain Reaction ; Prognosis ; RNA, Messenger