Study On The Expression And Function Of Long Non-Coding Rna UCA1 In Colorectal Cancer

Part I Study on the expression of long non-coding RNA UCA1 in colorectal cancerAim:To verify the effect of UCA1 on cell proliferation, cell cycle, apoptosis and drug resistance of colorectal cancer cells in vitro and the effect of UCA1 on tumor formation in vivo.Methods: Real-time RT-PCR was used to detect the expression of UCA in CRC tissues and their paired adjacent noncancerous tissues(NCTs).The clinicopathological information and prognosis of these 90 cases were collected. Logistic regression analysis was performed to analyse the relationship between the UCA1 expression and the clinicopathological characteristics.Survival rate were calculated by the Kaplan-Meier method with the log-rank test applied for comparison. Survival data were evaluated using univariate and multivariate Cox proportional hazards model.Results:We found that the expression of UCA1 in CRC tissues was conspicuously higher than that observed in their NCTs(P< 0.01), and about 59% of CRC tissues showed more than twice expression of UCA1.Clinicopathological analysis showed that UCA1 was significantly correlated with a larger tumor size(P = 0.010), greater tumor depth(P = 0.041) and lymphatic invasion(P = 0.035). high UCA1 expression was significantly associated with a poor overall survival rate in CRC patiens(P= 0.0026). UCA1(HR=2.395, 95% CI=1.044-5.495, P=0.039), and distant metastasis(HR=3.004, 95% CI=1.310-6.899, P=0.009)were identified to be independent prognostic factors for survival of CRC.Conclusion:UCA1 was highly expressed in CRC tissues and correlated with the pathological factors and prognosis of the patients. UCA1 is an independent prognostic factor for the survival of patients with CRC. Part?Study on the function of long non-coding RNA UCA1 in colorectal cancerAim:To analyze the expression level of UCA1 in colorectal cancer(CRC) tissues and its relationship with clinical pathological factors and patien prognosis.Methods:CCK-8 assay was used to detect the effect of UCA1 knockdown and overexpression on the proliferation of CRC cells and 5-FU resistance.The effects of UCA1 on cell cycle and apoptosis were determined by flow cytometry.The role of UCA1 on proliferation in vivo was evaluated in xenograft models.Results:The proliferation ability of the cells was significantly decreased after UCA1 konckdown, but the ability was significantly increased after UCA1 overexpression.Clone formation assay also showed that UCA1 could increase the ability of clone formation of CRC cells.Tumor formation in nude mice proved that UCA1 konckdown inhibited the proliferation of CRC cells in vivo, and overexpression of UCA1 promoted the proliferation of CRC cells in vivo.Cells with UCA1 konckdown and overexpression were treated with different concentrations of 5-FU(0.5?1.0?2.0?4.0?10.0 and 50.0?g/m L). The cell activity was measured after 48 hours by CCK-8, the data showed that knockdown of UCA1 in HCT116 cells significantly increased the drug sensitivity of 5-FU, and overexpression of UCA1 in SW480 cells significantly reduced the drug sensitivity of 5-FU.Knockdown UCA1 could significantly increase the proportion of apoptotic cells, and overexpression of UCA1 could significantly decrease the proportion of apoptotic cells.Conclusion:Functional assays revealed the in vitro and in vivo growth-promoting function of UCA1 and revealed that UCA1 can decrease the sensitivity of CRC cells to 5-FU by attenuating apoptosis.Part?Study on the mechanism of UCA1 in colorectal cancerAim: To investigate the mechanism of UCA1 promoting tumor cell proliferation and resistance to 5-FU in colorectal cancer tissues.Methods: Luciferase assay was used to verify whether mi R-204-5p and UCA1 are combined by MRE.RNA immunoprecipitation(RIP) was performed to capture the Ago2 protein and the RNA binding with it by Ago2 anbibody, then the expression of UCA1 and mi R-204-5p was detected by real-time RT-PCR.Luciferase assay was used to verify whether CREB1 is the target gene of mi R-204-5p.RNA immunoprecipitation and Western blot were used to demonstrate the potential regulatory relationship among UCA1, mi R-204-5p and mi R-204-5p target genes.Finally, the expression of CREB1 in CRC tissue was detected by immunohistochemistry.Results:Mechanistic studies revealed that UCA1 could sponge endogenous mi R-204-5p and inhibit its activity. We also identified CREB1 as a new target of mi R-204-5p. The protein levels of CREB1 were significantly up-regulated in CRCs and were associated with poor prognoses. UCA1 levels were positively correlated with the expression of mi R-204-5p target genes(CREB1, BCL2 and RAB22A)in CRC tissues.Conclusion:UCA1 up-regulated the target genes of mi R-204-5p(BCL2, RAB22 A and CREB1) by competitively sponging mi R-204-5p, and thus promoted the proliferation and chemoresistance of CRC cells.