AIM:To study the function of N-myc downstream-regulatedgene 1(NDRG1)in colorectal cardnogenesis and its correlationwith tumor lymph node metastasis.METHODS:NDRG1 was detected at its protein level byimmunohistochemistry(IHC)and image analysis(IA),andNDRG1 mRNA was detected by in situ hybridization(ISH)in formalin-fixed and paraffin-embedded sections with atotal of 190 specimens including 38 normal colorectalmucosae,31 colorectal adenomas,45 non-metastaticcolorectal carcinomas(CRCs),38 metastatic primary CRCand subsequently regional lymph nodes respectively.Atthe same time,the correlations of NDRG1 with sex,ageof patients and histological types of colorectal carcinomaswere observed.RESULTS:NDRG1 proteins were gradually increased incolorectal carcinogenesis(P<0.05 or P<0.01).There was asignificant difference in the expression of NDRG1 betweennon-metastatic and metastatic CRCs(P<0.05),and thecorrelation was positive(P<0.01,r_5=0.329).However,therewas no obvious difference in the expression of NDRG1between the primary sites of CRCs and that in the metastaticsites of corresponding regional lymph nodes,nor was therean apparent difference in sex,age,and histological types.The expression of NDRG1 mRNA was generally in concordancewith that of NDRG1 protein.CONCLUSION:NDRG1 gene may play an important role incolorectal carcinogenesis.In addition,NDRG1 may be aputative tumor metastasis promoter gene and is regardedas one of the molecular biological markers that can forecastearly metastasis of CRCs.NDRG1 gene in the metastaticsites of regional lymph nodes may preserve its expressioncharacteristics in the primary sites of CRCs to some extent.The expression of NDRG1 is not affected by sex,age andhistological types.The role of NDRG1 in tumor metastaticprocess can be demonstrated by in vivo and in vitro. AIM: To study the function of N-myc downstream-regulatedgene 1 (NDRG1) in colorectal cardnogenesis and its correlation with tumor lymph node metastasis. METHODS: NDRG1 was detected at its protein level by immunohistochemistry (IHC) and image analysis (IA), and NDRG1 mRNA was detected by in situ hybridization (ISH) in formalin-fixed and paraffin-embedded sections with atotal of 190 specimens including 38 normal colorectal mucosae, 31 colorectal adenomas, 45 non-metastatic colorectal carcinomas (CRCs), 38 metastatic primary CRC and subsequently regional lymph nodes .Atthe same time, the correlations of NDRG1 with sex, ageof patients and histological types of colorectal carcinomaswere observed .RESULTS: NDRG1 proteins were gradually increased incolorectal carcinogenesis (P <0.05 or P <0.01) .There was asificificant difference in the expression of NDRG1 betweennon-metastatic and metastatic CRCs (P <0.05), and thecorrelation was positive (P <0.01, r_5 = 0.329) .Where, therewas no obvious difference in the expression of NDRG1between the primary sites of CRCs and that in the metastaticsites of corresponding regional lymph nodes, nor was therean apparent difference in sex, age, and histological types. The expression of NDRG1 mRNA was generally in concordance with that of NDRG1 protein. CONCLUSION: NDRG1 gene may play an important role in the development of incolorectal carcinogenesis. In addition, NDRG1 may be a putative tumor metastasis promoter gene and is considered as one of the molecular biological markers that can forecastely metastasis of CRCs.NDRG1 gene in the metastaticsites of regional lymph nodes may preserve its expression characteristics in the primary sites of CRCs to some extent. The expression of NDRG1 is not affected by sex, age and histological types. The role of NDRG1 in tumor metastatic process can be demonstrated by in vivo and in vitro.