ABSTRACT
PURPOSE: Colorectal cancer (CRC) is the third most common cancer in China and poses high morbidity and mortality. In recent years, increasing evidence has indicated that microRNAs played important functions in the occurrence and development of tumors. The purpose of this study was to identify the biological mechanisms of miR-362 in CRC. MATERIALS AND METHODS: Quantitative real-time PCR was carried out to assess the expression of miR-362 and SIX1. The Kaplan-Meier method was employed to evaluate the 5-year overall survival of CRC patients. The proliferative and invasive abilities of CRC cells were assessed by MTT and transwell assays. RESULTS: miR-362 was significantly decreased in CRC tissues and cell lines, compared to the normal tissues and normal cells. A significant connection was confirmed between the overall survival of 53 CRC patients and low expression of miR-362. Downregulation of miR-362 inhibited the proliferation and invasion through binding to the 3′-UTR of SIX1 mRNA in CRC. Additionally, we discovered that SIX1 was a direct target gene of miR-362 and that the expression of miR-362 had a negative connection with SIX1 expression in CRC. SIX1 could reverse partial functions in the proliferation and invasion in CRC cells. CONCLUSION: miR-362 may be a prognostic marker in CRC and suppress CRC cell proliferation and invasion in part through targeting the 3′-UTR of SIX1 mRNA. The newly identified miR-362/SIX1 axis provides insight into the progression of CRC.
Subject(s)
Humans , Cell Line , Cell Proliferation , China , Colorectal Neoplasms , Down-Regulation , Methods , MicroRNAs , Mortality , Real-Time Polymerase Chain Reaction , RNA, MessengerABSTRACT
Objective To evaluate the effects of hyperbaric oxygen on the expressions of hypoxia-inducible factor 1α (HIF-1α) and insulin-like growth factor-1 receptor (IGF-1R) in the formation of hyperplastic scar in rabbit ears.Methods The ears of 20 New Zealand rabbits were used to construct an animal model for hyperplastic scar by operation.After the establishment of scar models,the rabbits were randomly divided into 4 experimental groups and one control group with 4 mice (48 wound surfaces) in each group.The mice in the 4 experimental groups were treated with hyperbaric oxygen for 7,14,21 and 28 days,respectively,and those in the control group remained in normoxic environment after operation.Scar tissues were resected from all the rabbit ears on day 29 after operation.Hematoxylin and eosin (HE) staining was conducted for the observation of morphological changes and calculation of scar elevation index,and immunohistochemistry to measure the expressions of HIF-1α and IGF-1R.Statistical analysis was carried out by one-way analysis of variance followed by least significant difference t-test.Results HE staining showed that both the number of fibroblasts and amount of collagen fibers were significantly reduced in the experimental groups compared with the control group.Scar elevation index was 4.28 ± 0.22 in the control group,3.64 ± 0.29,3.46 ± 0.21,3.29 ± 0.21,3.16 ± 0.15 in the 7-,14-,21-and 28-day experimental groups respectively,with significant differences among these groups (F =77.70,P ＜ 0.05).The expressions of HIF-1α and IGF-1R were significantly lower in these experimental groups than in the control group (all P ＜ 0.01),lower in the 14-day group than in the 7-day group (P ＜ 0.05),and lower in the 21-day group than in the 14-day group (P ＜ 0.05),with no significant differences between the 28-day group and 21-day group (both P ＞ 0.05).Conclusion Hyperbaric oxygen can effectively down-regulate the expressions of HIF-1α and IGF-1R in scar tissue,and significantly inhibit the formation of hyperplastic scar in rabbit ears.
ABSTRACT
Background Retinopathy of prematurity is mainly due to retinal neovascularization.Objective This laboratory work was to evaluate the efficacy of different dosage of avastin for inhibiting retinal neovascularization.Methods Ninety 7-day-old clean C57BL/J6 mice were randomized into six groups as follows:air control group,hyperxia control group,hyperxia BSS group and avastin groups.C57BL/J6 mice in air control group were raised in regular air environments.The fifty mice were fed under the environment with 75％ ±2％ oxygen for 5 days to establish the retinal neovascularization models.The 1.25,2.50 and 5.00 g/L avastin (0.5 μl) were injected inteavtreally in forty-five mice models as low,moderate and high dosage avastin groups respectively,and 0.5 μl BSS was used at the same way in fifteen models as hyperxia BSS group.The mice were sacrificed in the 17-day-old age using excessive anesthesia method and the retina sections were prepared for the calculation of the numbers of vascular endothelial cell nuclei broken retinal inner membrane after hemotoxylin and eosin staining.The expression of CD34 in the retina was detected by immunochemistry.The morphology and distribution of retinal neovascular vessel in various groups were observed using retinal flat.The use of the animals followed the Regulations for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results The numbers of cell nuclei broken the inner limiting membrane was significant increased in the hyperxia group compared with the air control group( P＜0.01 ),and those in difference doses of avastin were considerably reduced in comparison with hyperxia BSS group (P＜0.01) and hyperxia group (P＜0.01 ).The decrease of numbers of cell nuclei broken the inner limiting membrane was obvious in low dose of high dose of avastin compared with low dose of avastin (P＜0.05 ).CD34 was positively expressed in retina internal membrane of hyperxia group.Retinal flat revealed the regular distribution and normal structure of retinal vessels in air control group and avastin groups.However,retinal and vitreous cavity neovascularization,leakage and enlarged non-perfusion regions in the perimeter of the retina were seen in hyperxia group and hyperxia BSS group. Conclusions Intravitreal injection of avastin can arrest retinal angiogenesis in oxygen-induced retinal neovascularization models in a dose-dependent manner.