RESUMEN
BACKGROUND: Colorectal cancer (CRC) is the third leading cause of cancer-related deaths. 5-Fluorouracil (5-FU)-based chemotherapy has always been the first-line treatment. However, development of 5-FU resistance seriously affects its curative effect. The aim of this study was to elucidate the molecular mechanisms of 5-FU resistance through miR-106a-5p in CRC. METHODS: Colorectal cancer tissues were collected to analyze miR-106a-5p and TGFßR2 expressions by qPCR. Functional experiments for evaluating cell survival and metastasis were conducted to observe the biological effects of miR-106a-5p and TGFßR2. The cell survival rate was calculated using an MTT assay; the metastasis was confirmed with a Transwell invasion assay and Western blotting, which we used to measure the expression levels of the epithelial-mesenchymal transition (EMT) markers E-cadherin and vimentin. The combination of miR-106a to TGFßR2 was predicted using Targetscan, and confirmed through the construction of the luciferase reporter plasmid pGL3-basic. The interplay between miR-106a-5p and TGFßR2 was tested with qPCR and Western blotting. A Spearman rank analysis was employed to verify the correlation of miR-106a-5p and TGFßR2 expressions. RESULTS: MiR-106a-5p was up-regulated and TGFßR2 was down-regulated in 5-FU resistant CRC tissues and HT-29 cells. MiR-106a-5p promoted cell survival and suppressed the apoptosis rate and caspase 3 activity. Additionally, cell invasion was promoted by miR-106a-5p overexpression in the HT-29 cells and was inhibited by miR-106a-5p knockdown in the 5-FU resistant HT-29 cells; miR-106a-5p overexpression contributed to migration by increasing vimentin expression and by decreasing E-cadherin expression in the HT-29 cells; miR-106a-5p functioned by directly binding to TGFßR2. The TGFßR2 knockdown conferred chemoresistance of 5-FU and metastasis in 5-FU resistant HT-29 cells, and TGFßR2 overexpression reduced cell survival, invasion numbers, vimentin expression, and increased the cell apoptosis rate and caspase 3 activity in 5-FU resistant HT-29 cells. Also, miR-106a-5p negatively regulated TGFßR2 in a linear correlation way in the CRC tissues. CONCLUSION: The up-regulation of miR-106a-5p contributes to the pathomechanism of colorectal cancer by promoting 5-FU resistance and metastasis via inhibiting target TGFßR2. Our findings provide new promising ways for the clinical application of the TGFßR2-miR-106a axis in clinical chemotherapy for 5-FU resistant colorectal cancer.
RESUMEN
OBJECTIVE: To evaluate the effect of microecologic treatment combined enteral nutrition on serum endotoxin, tumor necrosis factor-α (TNF-α), interleukin-18 (IL-18), blood ammonia levels and nutritional status in patients with hepatic encephalopathy. METHODS: 60 patients with hepatic encephalopathy were allocted randomly into 3 groups, on the basis of conventional liver protective therapy and uragogue with one group given probiotics plus enteral nutrition, one given probiotics only, and the 3rd group given intravenous nutrition. The whole course of treatment was four weeks. Serum levels of endotoxin, TNF-α, IL-18, ammonia and albumin were determined before and on the 7th and 14th day after treatment. RESULTS: The levels of serum endotoxin, TNF-α, IL-18 and blood ammonia in the combined treatment group decreased remarkably after treatment, while the level of serum albumin elevated markedly. The difference was significant at statistics as compared with the only probiotics group and intravenous nutrition group (P < 0.05). CONCLUSION: Microecologic treatment combined enteral nutrition could effectively reduce blood ammonia and serum endotoxin levels, protect intestinal mucosal barrier, as well as improve nutritional status of patients with hepatic encephalopathy, which was considered as a safe and efficient therapy.
