| Colorectal cancer(CRC)is one of the most common malignant tumors in the world.It has the third highest incidence and the second highest mortality.In China,colorectal cancer is also one of the leading causes of death from malignant tumors.Therefore,it is of great research value to explore the development mechanism of colorectal cancer and to find potential therapeutic targets for colorectal cancer.Long non-coding RNA(lncRNA)is a kind of RNA with a length of>200 nucleotides and no protein-coding potential,abnormal expression of lncRNA is closely related to many diseases,and numerous lncRNAs have been found to be involved in regulating the occurrence and development of colorectal cancer.Studies have confirmed that lncRNA SNHG4(later referred to as SNHG4)plays an important regulatory role in the progression of various malignancies.Our previous bioinformatics analysis found that SNHG4 expression was up-regulated in colorectal cancer,but the relationship between SNHG4 and colorectal cancer progression remains to be further clarified.Therefore,the main purpose of this study is to explore the role of SNHG4 in the development of colorectal cancer and to preliminarily explore its possible molecular mechanism.Methods1.The expression of SNHG4 in colorectal tissues1)The expression of SNHG4 in colorectal cancer tissues was analyzed by ENCORI database and oncomine database.2)qRT-PCR assay was used to detect the expression of SNHG4 in 86 pairs of colorectal cancer tissues and their paired adjacent normal tissues.2.The effect of SNHG4 on malignant biological behavior of colorectal cancer cells in vitro1)qRT-PCR assay was used to detect the expression of SNHG4 in colorectal cancer cells,and select Cell lines for gene editing2)The effects of SNHG4 on proliferation,migration,invasion,apoptosis and chemotherapy resistance of colorectal cancer cells were verified by CCK8 assay,plate clone formation assay,transwell assay and cell apoptosis assay.3)subcutaneous tumor formation experiments in nude mice verified the effect of SNHG4 on tumor formation in colorectal cancer cells.3.Bioinformatics analysis and preliminary identification of SNHG4 target geneCombined with the results of overexpressed SNHG4 sequencing and predicted target gene database,candidate target genes were screened and verified by qRT-PCR.Results1.SNHG4 is highly expressed in colorectal cancer tissues Data mining in ENCORI and oncomine database found that SNHG4 was highly expressed in colorectal cancer tissues.The qRT-PCR results demonstrated the same thing.2.SNHG4 promotes the malignant biological behavior of colorectal cancerCCK8 cell proliferation experiment and plate cloning experiment showed the cell growth rate and the number of clones increased in the SNHG4 overexpression group.Transwell cell migration and invasion experiments indicated the number of migrated and invaded cells increased in the SNHG4 overexpression group.Cell apoptosis experiment reveled the apoptosis rate of the SNHG4 overexpression group decreased,and the resistance to 5-fu chemotherapy increased.While the SNHG4 interference group was the opposite.After interfering with SNHG4,the subcutaneous tumorigenesis of colorectal cancer cells decreased significantly.3.SNHG4 may regulate MYC through competitive binding of mir-510-5pFirst,miRNA binding to SNHG4 was predicted by ENCORI database,and 6 significantly down-regulated miRNA were further screened by qRT-PCR as candidate target genes.Then,the sequencing results of overexpressed SNHG4 were enriched by the pathway,and the path-related mrnas were verified by qRT-PCR.The results showed that MYC up-regulation was the most obvious.Bioinformatics analysis found that among the six candidate target genes,miR-510-5p had binding sites with SNHG4 and MYC at the same time,and preliminarily confirmed the possible interaction among the three.ConclusionSNHG4 is highly expressed in colorectal cancer tissues.SNHG4 may play a regulatory role by acting as ceRNA,that is,competitively binding mir-510-5p to regulate MYC to promote the malignant biological behavior of colorectal cancer cells. |
