Abstract:Objective To detect the expression of lysosome-associated membrane protein 1(LAMP1) in colorectal cancer (CRC) and study the relationship between LAMP1 expression and important clinical and pathological indicators of CRC, especially disease prognosis. Methods The expression and prognostic characteristics of LAMP1 in CRC were retrieved through bioinformatics analysis at the big data level. qPCR and immunohistochemical (IHC) detection were performed on 10 clinical CRC tumor tissues and tissue chips containing 60 CRC samples. Univariate and multivariate Cox regression and Kaplan-Meier survival analysis were used to analyze the prognostic factors of CRC. Results Big data showed that LAMP1 protein was mainly located in lysosomes and had varying degrees of high expression in CRC cell lines, and was significantly higher in CRC tumor tissues than in normal control tissues. The recurrence free survival (RFS) and overall survival (OS) of CRC patients with high LAMP1 expression were lower than those with low LAMP1 expression. Both qPCR and IHC results of 10 clinical cases showed that the expression of LAMP1 in CRC was significantly higher than that in adjacent control tissues (P＜0.05). In the analysis of 60 cases of cohort, univariate Cox model analysis showed that LAMP1 expression (P=0.030), tumor differentiation (P=0.041), CEA level (P=0.028) and distant metastasis (P=0.002) were significantly correlated with the prognosis of CRC. Multivariate analysis showed that tumor differentiation (P=0.006) and distant metastasis (P=0.041) were independent prognostic factors; Survival analysis showed that the overall survival was shorter in patients with high expression of LAMP1, poor tumor differentiation, CEA level≥15 ng/mL and positive distant metastasis. Conclusion LAMP1 is abnormal highly expressed in CRC. LAMP1 expression is significantly correlated with CRC malignant phenotype, which may serve as a predictive indicator of CRC prognosis.