Relationship between nm23H1 genetic instability and clinical pathological characteristics in Chinese digestive system cancer patients.

AIM: To study the relationship between nm23H1 gene genetic instability and its clinical pathological characteristics in Chinese digestive system cancer patients. METHODS: Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to analyze the microsatellite instability (MSI) and loss of heterozygosity (LOH). Immunohistochemistry was employed to detect the expression of nm23H1. RESULTS: The MSI was higher in TNM stage I + II than in stage III + IV of gastric, colonic and gallbladder carcinomas. The LOH was higher in TNM stage III + IV than in stage I + II of gastric, colonic and hepatocellular carcinomas. Lymphatic metastasis was also observed. The expression of nm23H1 protein was lower in TNM stage III + IV than in stage I + II of these tumors and in patients with lymphatic metastasis.The nm23H1 protein expression was higher in the LOH negative group than in the LOH positive group. CONCLUSION: MSI and LOH may independently control the biological behaviors of digestive system cancers. MSI could serve as an early biological marker of digestive system cancers. Enhanced expression of nm23H1 protein could efficiently inhibit cancer metastasis and improve its prognosis. LOH mostly appears in late digestive system cancer.

Lymphatic metastasis and nm23H1 genetic instability in Chinese colon cancer patients.

AIM: To investigate the pathogenic mechanism of colon cancer 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. Polymerase chain reaction-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 SPSS software of statistics. RESULTS: ICAM-1 expression of lymphatic endothelium was negative in normal colon and positive in colon cancer respectively. The number of lymphatics positive for ICAM-1 was gradually increased with degree of cancer invasion (P<0.01). In the group with metastasis of colon cancer, the number of lymphatics positive for ICAM-1 in lymph nodes was more than that in the group with no metastasis (P<0.01). The frequency of MSI, LOH and nm23H(1) protein was 26.67%, 20.00% and 53.33% in colon cancer, respectively. In TNM staging, MSI (43.75%) and nm23H(1) protein (81.25%) in stages I+II were detected more easily than the corresponding indexes (MSI: 7.14%, P<0.05 and nm23H(1): 21.43%, P<0.01) in stages III+IV. By comparison, the frequency of LOH (35.71%) in stages III+IV was more than that of LOH (6.25%, P<0.05) in stages I+II. LOH exhibited a rising trend along with the Duke's staging. nm23H(1) protein in the group of tubular adenocarcinoma (60.00%) was higher expressed than that in the group of mucoid adenocarcinoma (20.00%) (P<0.01), and exhibited a rising trend with the differentiation degrees of tubular adenocarcinoma. nm23H(1) protein in MSI positive group was higher expressed (75%) than that in MSI negative group (45.45%, P<0.05). CONCLUSION: The expression of ICAM-1 in lymphatic vessels is beneficial to the judgement of the invasion and metastasis ability of colon cancer and the anti-tumor immunity function, and shows an important clinical significance in predicting lymphatic metastasis of colon cancer. MSI and LOH may separately 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 and poor prognostic phenotype. By compassion, MSI may be an early 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.

[Genetic instability of gene nm23H1 in colon cancer of Chinese patient].

Techniques such as DNA extraction from paraffin-embedded tissues, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), ordinary silver stain, Envision immunohistochemistry and Leica-Qwin computer imaging techniques were used to study microsatellite instability (MSI) and loss of heterozygosity (LOH) of locus D17S396 at the 17th chromosome of Chinese patients and their influence on the expression of gene nm23H1, and to clarify the relationship between the genetic instability of gene nm23H1 and the development of colon cancer, which may provide experimental basis for clinical treatment. In our experiments, the frequency of MSI, LOH and nm23H1 protein reacted positive of 30 cases of colon cancer were 26.67%, 20.00% and 53.33% respectively. In tumor node metastasis (TNM) staging, the positive frequency of MSI (43.75%) and nm23H1 protein (81.25%) in stage I + II were more than those (MSI 7.14%, p < 0.05 and nm23H1 21.43%, p < 0.01) in stage III + IV, while the frequency of LOH (35.71%), which had a rising trend along with the Duke's staging increasing, was higher than that of LOH (6.25%, p < 0.05) in stage I + II. The positive frequency of nm23H1 protein in the group of tubular adenocarcinoma (60.00%) was distinctively higher than that in the group of mucoid adenocarcinoma (20.00%, p < 0.01), showing a rising trend along with the increase of the differentiation degree of tubular adenocarcinoma. Furthermore, the positive frequency of nm23H1 protein in MSI positive group was also higher than MSI negative group (p < 0.05). And there was no difference in nm23H1 protein expression analyzed by computer imaging techniques. The results of experiments indicated that both MSI and LOH controlled the development of sporadic colon cancer independently in different paths. LOH occurred mostly in the late period of sporadic colon cancer and endowed with it a high aggressive and poor prognosis. In contrast, MSI was an early period molecule marker of sporadic colon cancer. Increasing the amount of nm23H1 protein expression could effectively restrain colon cancer metastasis and improved prognosis of sporadic colon cancer patients.