Objective To explore the expressions of caudal-related homeodomain transcription factor-2 （CDX-2）and tumor suppressor gene KAI-1 in colon carcinoma tissues and to analyze their clinical significances. Methods Immu-nohistochemical SP method was used to detect the expressions of CDX-2 and KAI-1 in 50 cases of colon carcinoma tissues and corresponding adjacent tissues （from cancer tissue ≤2cm） and 25 cases of normal colon mucosa tissues. The relation-ships of the expressions of CDX-2 and KAI-1 to the clinicopathologic features were analyzed. Results ①The positive rates of CDX-2 expression and KAI-1 expression in the colon carcinoma tissues were significantly lower than those in the normal colon mucosa tissues 〔CDX-2：34% （17/50） versus 88% （22/25）， P＜0.05；KAI-1：30% （15/50） versus 92% （23/25）， P＜0.05〕 and adjacent tissues of colon carcinoma 〔CDX-2：34% （17/50） versus 54% （27/50）， P＜0.05；KAI-1：30% （15/50） versus 58% （29/50）， P＜0.05〕， which in the adjacent tissues of colon carcinoma were significantly lower than those in the normal colon mucosa tissues （P＜0.05）. ②The positive expressions of CDX-2 and KAI-1 were related to lymph node metastasis， depth of invasion， and degree of tumor differentiation （P＜0.05）. ③Spearman rank correl-ation analysis showed that the CDX-2 expression was positively correlated with KAI-1 expression （rs=0.544， P＜0.01）. Conclusions CDX-2 and KAI-1 may be closely related to the development， invasion， metastasis， and prognosis of colon carcinoma， the combination of CDX-2 and KAI-1 in evaluation of their function has a certain guiding significance in the treatment for colon carcinoma.
ObjectiveTo summarize the role of survivin gene in tumor. MethodsThe research status on biological characteristics the role of survivin gene in tumor for gene therapy and clinical application was retrospectively analyzed after related domestic and foreign literatures were reviewed. ResultsSurvivin gene was by far found to be the best powerful apoptosis inhibition gene, which played antiapoptosis role mainly through inhibiting directly the activity of caspase-3 and caspase-7 in the downstream of cascade reaction. Survivin gene promoted tumor cell proliferation and differentiation through speeding up tumor cells transition of G1→S phase and eluding the recognition of tumor cells to the apoptosis in G2/M phase. Survivin gene played important role in the intermediate links of vasiformation through angiogenic factor (VEGF, bFGF, Ang-1, and COX-2). ConclusionSurvivin gene may inhibit the apoptosis, promote the proliferation and differentiation of tumor cells and tumor angiogenesis, suggested that survivin gene has potential to act as a novel tumor marker and become an indicator of malignant tumor.
【Abstract】 Objective To investigate the relationship between methylation of tumor suppressor gene and gastric cancer. Methods The literatures in recent years about the concept of methylation, its biological significance and the relationship between DNA methylation/demethylation and gastric cancer were reviewed. The effects of methylation of different tumor suppressor genes on gastric cancer were also analyzed. Results The effect of aberrant methylation on the development and the progression of gastric cancer was still unclear but it was supposed that the inactivation of genes related with cell cycle regulation, mitotic checkpoint, apoptosis, DNA mismatch repair, metastasis suppression and so on might be attributable to the aberrant methylation in gastric cancer. Conclusion Aberrant methylation of tumor suppressor genes plays an important role in the development and progression of gastric cancer. The status of methylation of tumor suppressor genes may be used as a useful molecule marker for diagnosis, assessing metastasis and evaluating prognosis, and demethylation could possibly be a new therapy for gastric cancer.
【Abstract】ObjectiveTo investigate the relationship between tumor suppressor gene DPC4 and the development and prognosis of pancreatic carcinoma. MethodsRelevant literatures of recent years were reviewed. ResultsDPC4 was located on chromosome 18. Its product was Smad 4 protein. Smad 4 protein was the central component of the transforming growth factor-beta signaling pathway, and all the biological effect was the results of interaction of Smad 4 and different Smads. The gene was deleted or inactive in about 50% of pancreatic carcinomas. The deletion of DPC4 had a great relation to the development and prognosis of pancreatic carcinoma. ConclusionThe alteration of tumor suppressor gene DPC4 is connected with the development and prognosis of pancreatic carcinoma. However, this research should be further studied.
Objective To investigate the effect of tumor suppressor gene on tumourigenesis in multiple primary malignant neoplasm (MPMN).Methods The retrospective analysis was used to summarize several common tumor suppressor genes correlation to MPMN. Results At current study of the tumor suppressor genes, the common genes studied in MPMN were p53, APC, p16, BRCA1, BRCA2 and PTEN/MMAC1, etc. The same mutation of tumor suppressor genes could be detected from PMNNs. Conclusion There are significant relations between MPMN and inactivation of tumor suppressor gene. By the study of tumor suppressor gene, it can reveal some common rules of tumourigenesis of MPMN.
ObjectiveTo summarize and analyze the relevant studies about the tumor suppressor phosphatase and tensin homolog deleted on chromosome ten (PTEN) and thyroid tumor then further elucidate?the possible mechanism of thyroid tumor formation and progression. Mothods Domestic and international literatures investigating the correlation between PTEN and thyroid tumor were retrieved and reviewed. ResultsThe abnormal expression of PTEN protein resulted by the mutation or methylation of PTEN gene may up-regulate the expression of its downstream effectors such as PI3K, mTOR, FAK, etc. This probably correlate with thyroid neoplasia and progression. Conciusions Abnormalites of PTEN and its downstream signal ways may correlate with the initiation and development of thyroid tumors. However, the specific mechanism still remains unclear and need more further researches