RESUMO
Colorectal cancer (CRC) is a common digestive system malignancy with high morbidity and mortality. Accumulating studies have shown that miRNAs play a critical role in the progression of CRC. Here, we explored the effect of miR-329 and its target gene on the sensitivity of 5-fluorouracil (5-FU) in the chemotherapy of CRC. RT-qPCR was utilized to determine the expression of miR-329 in cancer tissues, adjacent tissues and cells. CCK-8 and Transwell assays were introduced to detect the role of miR-329 overexpression in cell viability and invasion. Luciferase reporter assay was performed to verify that E2F1 was a direct target of miR-329. Protein expression of E2F1 was accessed by western blot analysis. The expression level of miR-329 was decreased in CRC tissues and tumor tissues at stage III+IV with lymph node metastasis, and the patients' total survival time was positively associated with the expression of miR-329. Overexpression of miR-329 significantly attenuated the viability and invasiveness of tumor cells. The viability of drug-resistant cells was markedly higher than that of non-resistant cells under the same dose of 5-FU treatment. The expression of miR-329 in tumor cells was negatively associated with drug sensitivity. Luciferase reporter assay showed that E2F1 was the direct target of miR-329. Besides, the expression of E2F1 protein in drug-resistant cells was remarkably higher than that in the non-resistant cells, while the overexpression of miR-329 significantly decreased the expression of E2F1 protein. E2F1 overexpression increased cell viability, but overexpression of both E2F1 and miR-329 in turn decreased cell viability. miR-329 expression is reduced in CRC, and overexpression of miR-329 promotes the sensitivity of 5-FU in the chemotherapy of CRC by degrading the target gene E2F1.
RESUMO
OBJECTIVE: To observe the effects of electroacupuncture (EA) on cochlea morphology and expression of aquaporin 1 (AQP1) in guinea pigs with endolymphatic hydrops, so as to explore the possible mechanism of EA on endolymphatic hydrops. METHODS: Forty guinea pigs were randomly divided into a blank group, a model group, a medication group and an EA group, 10 guinea pigs in each one. Model of endolymphatic hydrops was established by using intraperitoneal injection of aldosterone. Guinea pigs in the blank group and model group were treated with identical immobilization as EA group but no treatment was given; guinea pigs in the medication group were treated with intragastric administration of hydrochlorothiazide at a dose of 5 mg/kg, once a day for consecutive 10 days; guinea pigs in the EA group were treated with' EA at "Baihui" (GV 20) and "Tinggong"(SI 19), once a day for consecutive 10 days. The serum ionic concentration in each group was tested by turbidimetric method; hematoxylin-eosin staining was used to measure the severity of cochlea hydrops; immunohistochemical method was used to observe the expression of AQP1 in the cochlea. RESULTS: (1) There was no endolymphatic hydrops in the blank group, moderate-severe endolymphatic hydrops in the model group and slight endolymphatic hydrops in the EA group and medication group. (2) The concentration of K+ and Ca2+ in the EA group was higher than that in the model group and medication group (all P<0. 01); the concentration of Na+ was lower than that in the model group (P< 0. 01) but higher than that in the medication group (P<0. 01); the concentration of Cl- was higher than that in the medication group (P<0. 01), but not significantly different from the model group (P>0. 05). (3) The ratio of expression area of AQP1 in the model group was lower than that in the blank group (P<0. 01); the ratio of expression area of AQP1 in the EA group was higher than that in the model group (P<0. 01), and lower than that in the medication group without significant difference (P>0. 05). CONCLUSION: EA could relieve the endolymphatic hydrops in guinea pigs; the mechanism is likely to be related with up-regulating the expression of AQP1 in cochlea and ion concentration might be an important factor involved.
