Abstract: Objective To screen K-RAS mutation related key intergenic non-coding RNAs (lincRNA) in carcinoma of colon and rectum (CRC). Methods RNA-Seq and clinical data from the Cancer Genome Atlas (TCGA) were used to identify K-RAS mutation related lincRNA in CRC. The receiver operating characteristic (ROC) curves were used to analyze the relationship between differentially expressed lincRNA and the 5-year and 10-year survival rates of K-RAS wild-type or mutant patients. The key lincRNA was select. Kaplan-Meier survival curve was used to analyze the impact of the key lincRNA expression on the 5-year and 10-year survival rates of patients. The relationship between the key lincRNA and clinical characteristics was also analyzed. Results A total of 585 cancer tissue samples and 51 normal tissue samples were analyzed for RNA-Seq data. From the data, 6 452 lincRNAs were obtained, of which 85 were up-regulated and 40 were down-regulated. Twelve lincRNAs differentially expressed genes in K-RAS mutants were selected, among which AL390719.2 was the key prognosis lincRNA with K-RAS mutations. Survival analysis results showed that the expression of lincRNA AL390719.2 in the K-RAS mutant was related to the 10-year survival rate (Log-rank χ2 =10.740, HR=3.255, P= 0.002) and 5-year survival rate (Log-rank χ2 =11.720, HR=3.142, P=0.001) of patients. The expression of lincRNA AL390719.2 in the K-RAS wild type was not related to the prognosis (10-year: Log-rank χ2 =1.400, HR=0.822, P=0.221; 5- year: Log-rank χ2 =1.997, HR=0.774, P = 0.086). Patients with high expression of AL390719.2 showed a late clinical stage, and prone to lymph node metastasis and distant metastasis. Conclusion The high expression of lincRNA AL390719.2 is related to the poor prognosis and survival of K-RAS mutant CRC, which may be a new prognostic marker and therapeutic target of CRC.

Key words: colorectal neoplasms, prognosis, genes,ras;long intergenic non-coding RNA, K-RAS mutation, lincRNA AL390719.2