AIM:To investigate the pathogenic mechanism of coloncancer at the molecular level and to elucidate the relationshipbetween intercellular adhesion molecule-1(ICAM-1)andnm23H_1 genes and Chinese patients with colon cancer.METHODS:DNA was extracted from paraffin-embeddedmaterials.Polymerase chain reaction-single strand conformationpolymorphism(PCR-SSCP)was used to analyze MSI andLOH.Expression of ICAM-1 was detected by Envision immuno-histochemistry.Experimental results were analyzed withLeica-Qwin computer imaging techniques and SPSSsoftware of statistics.RESULTS:ICAM-1 expression of lymphatic endothelium wasnegative in normal colon and positive in colon cancer respectively.The number of lymphatics positive for ICAM-1 was graduallyincreased with degree of cancer invasion(P<0.01).In thegroup with metastasis of colon cancer,the number of lymphaticspositive for ICAM-1 in lymph nodes was more than that inthe group with no metastasis(P<0.01).The frequency ofMSI,LOH and nm23H_1 protein was 26.67%,20.00% and53.33% in colon cancer,respectively.In TNM staging,MSI(43.75%) and nm23H_1 protein(81.25%)in stages Ⅰ+Ⅱ weredetected more easily than the corresponding indexes(MSI:7.14%,P<0.05 and nm23H_1:21.43%,P<0.01)in stagesⅢ+Ⅳ.By comparison,the frequency of LOH(35.71%)instages Ⅲ+Ⅳ was more than that of LOH(6.25%,P<0.05)in stages Ⅰ+Ⅱ.LOH exhibited a rising trend along with theDuke’s staging,nm23H_1 protein in the group of tubularadenocarcinoma(60.00%)was higher expressed than thatin the group of mucoid adenocarcinoma(20.00%)(P<0.01),and exhibited a rising trend with the differentiation degreesof tubular adenocarcinoma,nm23H_1 protein in MSI positivegroup was higher expressed(75%)than that in MSI negativegroup(45.45%,P<0.05).CONCLUSION:The expression of ICAM-1 in lymphatic vesselsis beneficial to the judgement of the invasion and metastasisability of colon cancer and the anti-tumor immunity function,and shows an important clinical significance in predictinglymphatic metastasis of colon cancer.MSI and LOH mayseparately control the development of sporadic colon cancerwith different pathways.LOH mostly arises in the late periodof sporadic colon cancer and endows a high aggressive andpoor prognostic phenotype.By compassion,MSI may be anearly period molecule marker for sporadic colon cancer, enhanced expression of nm23H_1 protein can effectivelyinhibit colon cancer metastasis and improve prognosis ofsporadic colon cancer patients. AIM: To investigate the pathogenic mechanism of coloncancer at the molecular level and to elucidate the relationship between intercellular adhesion molecule-1 (ICAM-1) and nm23H_1 genes and Chinese patients with colon cancer. METHODS: DNA was extracted from paraffin-embedded materials. - single strand conformation polymorphism (PCR-SSCP) was used to analyze MSI and LOH. Expression of ICAM-1 was detected by Envision immuno-histochemistry. Experimental results were analyzed with Leica-Qwin computer imaging techniques and SPS Softwares statistics .RESULTS: ICAM- 1 expression of lymphatic endothelium wasnegative in normal colon and positive in colon cancer respectively. The number of lymphatics positive for ICAM-1 was gradually created with degree of cancer invasion (P <0.01) .In thegroup with metastasis of colon cancer, the number of lymphaticspositive for ICAM -1 in lymph nodes was more than that inthe group with no metastasis (P <0.01). The frequency of MSI, LOH and nm23H_1 protein was 26. 67%, 20.00% and53.33% in colon cancer, respectively.In TNM staging, MSI (43.75%) and nm23H_1 protein (81.25%) in stages Ⅰ + Ⅱ weredetected more easily than the corresponding indexes (MSI: 7.14%, P The frequency of LOH (35.71%) instages Ⅲ + Ⅳ was more than that of LOH (6.25%, P <0.05) in stages Ⅰ + LOH exhibited a rising trend along with theDuke’s staging, nm23H_1 protein in the group of tubularadenocarcinoma (60.00%) was higher than that of the in the group of mucoid adenocarcinoma (20.00%) (P <0.01), and exhibited a rising trend with the The differentiation of of tubular adenocarcinoma, nm23H_1 protein in MSI positivegroup was higher expressed (75%) than that in MSI negativegroup (45.45%, P <0.05) .CONCLUSION: The expression of ICAM-1 in lymphatic vesselsis to the judgment of the invasion and metastasisability of colon cancer and the anti-tumor immunity function, and shows an important clinical significance in predictinglymphatic me tastasis of colon cancer. MSI and LOH mayseparately control the development of sporadic colon cancer with different pathways. LOH mostly arises in the late period of sporadic colon cancer and endows a high aggressive andpoor ​​prognostic phenotype. BY compassion, MSI may be anearly period molecule marker for sporadic colon cancer , enhanced expression of nm23H_1 protein can effectively inhibit colon cancer metastasis and improve prognosis of sporadic colon cancer patients.