Genetic polymorphisms are thought to be associated with the individual difference in the esophageal cancer treatment.A large number of evidences show that 5-FU and cisplatin metabolism,apoptosis and angiogenesis related gene SNPs are associated with the therapeutic sensitivity of esophageal cancer.

miRNAs are endogenous short RNA molecules widely distributed in eukaryotic organisms.They are closely related to tumor development. One good example is miR-21. It is overexpressed in a variety of tumor tissues, suggesting that miR-21 may have significant carcinogenic activities and act as a oncogene.Many studies confirm that overexpression of miR-21 has great indication in the development, diagnosis, biological treatment and prognosis of gastrointestinal cancer.

hMSH6 is one of the most important members in the mismatch repair family. Its polymorphism is closely related to the pathogenesis and development of neoplasm, particularly in colorectal cancer and endometrial cancer. Moreover, it has been suggested to play a more important role in endometrial cancer compared with hMLH1 and hMSH2.

Variants of gene loci on susceptibility genes are the major individual susceptibility factors of esophageal squamous cell carcinoma (ESCC) in China.Some of the gene loci participate in the DNA damage and repair,and some are related with cancer suppressor genes,metabolism enzymes,trace elements and smoking.The single nucleotide polymorphisms of these susceptibility genes are closely correlated with the genesis of ESCC.

In recent years,a large number of researches show that the tumor related gene promoter hypermethylation is an important reason of esophageal adenocarcinoma and closely associated with the differentiation,invasion,metastasis,staging and prognosis of tumors.It might be used as a neww target for the clinical detection and therapy of esophageal adenocarcinoma.

With depth understanding of the mechanism of human leukocyte antigen G (HLA-G) protein,more and more studies have found that HLA-G is closely related with tumor immune escape.Numerous studies have shown that the expression of HLA-G protein and mRNA could be detected in patients with cancer.

AIM　To establish an allele specific PCR amplification (ASA-PCR) for determination of the genotype of CYP2D6*10B polymorphism in Chinese subjects. METHODS　CYP2D6*10B alleles of 65 healthy Chinese subjects were analyzed by a two-step PCR assay and the correlation of genotype and phenotype was studied. RESULTS　There were 20 CYP2D6*10B heterozygous genotypes subjects (wt/m) in 35 very extensive metabolizers (VEMs), which consisted the major part of VEM subjects (57%). Meanwhile, 20 subjects consisting 69% of 29 intermediate metabolizers were CYP2D6*10B homozygous mutant genotypes (m/m). The poor metabolizer was also m/m. The metabolic ratio of CYP2D6*10B m/m subjects were larger than wt/m and wild type, the values were -1.49±0.54, -2.20±0.49 and -2.47±0.61 (P<0.01). CONCLUSION　PCR-ASA was shown to be a rapid and specific method. It can be used to study the genetic polymorphism, especially CYP2D6 intermediate metabolism.

Objective To detect the expressions of microRNA-126 (miR-126) and microRNA-7 (miR-7) in esophageal squamous cell carcinoma (ESCC) and to analyze their correlations with clinicopathologic features and prognosis of ESCC.Methods The expressions of miR-126 and miR-7 in 116 ESCC samples and matched normal tissue samples were detected by real-time PCR.Statistical analysis was used to find the relationships among the expressions of miR-126 and miR-7,pathological characteristics and prognosis.Results Low expression,normal expression and high expression of miR-126 were found in 73 (62.9％),35 (30.2％) and 8 (6.9％) carcinoma samples respectively.Low expression,normal expression and high expression of miR-7 were found in 52 (44.8％),35 (30.2％) and 29 (25.0％) carcinoma samples respectively.The disease-free survival in patients with low expression of miR-126 and miR-7 was shorter than that in patients with non-low expression (x2 =4.268,P ＜0.05 ; x2 =4.993,P ＜0.05).The low expression of miR-126 was correlated with tumor location,family history and drinking (x2 =14.564,P ＜ 0.05 ; x2 =5.691,P ＜ 0.05 ; x2 =4.971,P ＜ 0.05),but was uncorrelated with gender,age,diferentiation,infiltration,lymphatic metastasis and smoking (all P ＞ 0.05).The low expression of miR-7 was uncorrelated with pathological characteristics of ESCC (all P ＞ 0.05).Conclusion The low expressions of miR-126 and miR-7 may be related to the prognosis of patients with ESCC,and have a certain clinical detection significance.

Objective To use the antisense of Platelet-derived growth factor ? chain (PDGF-?) gene to inhibit the proliferation of rabbit vascular smooth muscle cells(VSMCs) in order to provide in situ basis on prevention and treatment of human restenosis. Methods A rabbit restenotic vascular model was constrcted and an antisense designed according to PDGF-? cDNA sequence as a drug was used to observe its effects on the expression of proliferating cell nuclear antigen and in situ expression of platele-derived growth factor ? chain by the VSMCs and the formation of neointima after injury. Results The antisense could significantly inhibit the expression of proliferating cell nuclear antigen and downregulate in situ expression of PDGF-? mRNA by intimal VSMCs one week after injury with inhibitory rates of 93.44% and 88.40%, respectively. Conclusion The antisense designed could inhibit the formation of neointima after injury through downregulating the expression of PDGF-? mRNA by local VSMCs, which provides the experimental basis of the antisense for the prevention and treatment the human restenosis.

Researches find that microRNAs(miRNAs) participate in cell proliferation,differentiation and apoptosis.Dysregulation of miRNA exist in almost all kinds of tumors,including esophageal cancer.MiRNAs bind to mRNA of oncogene or tumor suppressor gene by perfectly or partly base-pair complementarity,and then,promote mRNA degradation or inhibit translation of target mRNA.Recently studies have comfirmed that miRNA functions as a significant regulator in esophageal cancer and it is involved in tumorigenesis,development and prognosis.MiR-21 binds to programmed cell death 4(PDCD4) mRNA and inhibits the translation of PDCD4,then promotes tumorigenesis of esophageal cancer.MiR-106-25 polycistron is activated by genomic amplification,and then suppresses the expressions of P21 and Rim,and subsequently promotes the occurrence and progress of esophageal cancer.