OBJECTIVE: Embryonic Stem Cell (ES) are characterized by totipotency and normal karyotype and provide the theoretical base in the following fields: embryonic developmeut of mammalian, cell differentiation, expres sion of exogenous genes and utilization of Ess to develop animal model for human inherited diseases. The identification of ES therefore is very important to research and utilize ES.DATA SOURCES: The relevant articles to embryonic stem cell between January 1980 and December 2003 were computer searched for in Medline with the key words "embryonic stem cell, embryo, Alkaline phosphatase,Oct-4"in English. Similarly, the relevant articles to embryonic stem cell between January 1980 and December 2003 were computer searched for in China Journal Full-text Database (CJFD) with the key word "embryonic stem cell" in Chinese.STUDY SELECTION: The articles were browsed firstly. The inclusion criteria were for those articles about the identification of embryonic stem cells. The exclusion criteria were for those about repetitive studies, reviews and other similar articles.DATA EXTRACTION: 16 articles about the identification of embryonic stem cells were collected. Then, the full-texts of the articles were looked through.DATA SYNTHESIS: The selected data were summarized in the following order: ①Preliminary identification of Ess based on morphology and growth;②Immunological valuation; ③Chromosome related identification; ④Identi fication of totipotency and pluripotency.CONCLUSION: The identification of embryonic stem cells is not the result of only one identifying method, but a process of identification. During this process of comprehensive identification, it is recommend to conduct AKP test firstly, karyotype analysis secondly, then examination of surface markers and finally identification of Ess totipotency when Ess are sufficient, takingcare to repeat every identification.

Objective To investigate the expressions of cell phenotypes CD_8 and CD_(28) of peripheral blood lymphocytes in patients with colorectal cancer. Method CD_8 and CD_(28) of cell phenotypes were measured by flow cytometry in 50 patients with colorectal cancer (cancer group) and 30 nontumorous patients (control group). Results The expression of CD_8 in cancer group was significantly higher than that in control group [(32.24±8.38)% vs (22.18±7.55)%](P < 0.01). CD_(28) and CD_8~+/CD_(28)~+ were much lower than those in control group [(52.03±10.94)% vs (60.60±7.98)%,12.18±4.28 vs 16.38±4.94](P<0.01). CD_8~+/CD_(28)~+ in Dukes D stage patients were significantly lower than that in Dukes B stage patients (P<0.05). CD_(28) and CD_8~+/CD_(28)~+ in lymph node metastasis patients were much lower than those in lymph node negative patients (P < 0.01). CD_(28) and CD_8~+/CD_(28)~+ in serosa involved patients were lower than those in no serosa involved patients (P < 0.01). Conclusions The expressions of cell phenotypes CD_8 and CD_(28) of peripheral blood lymphocytes in patients with colorectal cancer are closely related to biological characteristics of the tumor. The assays of cell phenotypes CD_8 and CD_(28) might be useful for evaluating the immunal statement and prognosis of patients with colorectal cancer.

Objective To investigate the expressions of homeobox gene 10 (HOXD10) and analyze its clinical significance. Methods Expressions of HOXD10 protein was detected by immunohistochemistry SP method in 53 cases of colorectal carcinoma tissues and corresponding normal tissues which was fixed by 4% formalin and embedded by paraffin.It was analyzed that the relationship between the expression of HOXD10 protein and clinico-pathological features. Results The positive staining rate of HOXD10 protein in normal colorectal mucosal tissue (5.7%)was significantly lower than that incolorectal carcinoma tissue(64.2%),the difference was statistically sig-nificant(P<0.05). In colorectal cancer tissue,the positive rate of HOXD10 protein in high differentiation(53.8%), T1+T2(38.5%),Ⅰ+Ⅱ(54.3%)and no lymph node metastasis(55.3%)was lower than that in low differentiation (73.0%),T3+T4(72.5%),Ⅲ+Ⅳ(83.3%)and lymph node metastasis,the difference was statistically significant (P < 0.05). However,it was not statistically significant between the positive rate of HOXD10 protein and the gender,age,primary site and tumor size in colorectal cancer patients(P>0.05). Conclusion The expression of HOXD10 protein is closely related to the invasion and metastasis of colorectal cancer.

Objective: To investigate the expression level of miR-9 in esophageal cancer and its effect on the biological function of esophageal cancer cells. Methods: The expression levels of miR-9 and Golgi phosphoprotein 3 (GOLPH3) in esophageal cancer and its adjacent tissues were detected by real-time fluorescence quantitative PCR (qRT-PCR). The miR-9 mimics was transfected into esophageal cancer EC109 cells, and the expression level of miR-9 was detected by qRT-PCR. The effects of overexpression of miR-9 on the biological function of EC109 cells were determined by the MTT assay, plate colony formation assay, Transwell migration assay and flow cytometry. The wild and mutant GOLPH3 double luciferase reporter gene vectors were constructed, and luciferase activity was detected. The effects of overexpression of miR-9 on the expression levels of GOLPH3 mRNA and protein were detected by qRT-PCR and Western blot. Results: Compared with the adjacent tissues, the expression level of miR-9 in esophageal cancer tissues decreased significantly (P＜0.01), while that of GOLPH3 increased significantly (P＜0.01). Compared with the negative control group, the expression level of miR-9 in EC109 cells transfected with miR-9 mimics increased significantly (P＜0.01), and the proliferation and migration ability of the EC109 cells decreased obviously (P＜0.01). The cell cycle of the EC109 cells was blocked in G2/M phase (P＜0.01). The dual luciferase reporter assay, qRT-PCR and Western blot confirmed that miR-9 could bind with GOLPH3 specifically (P＜0.01), and mediate the degradation of GOLPH3 mRNA (P＜0.01), which led to the decrease of GOLPH3 protein expression level (P＜0.05). Conclusion MiR-9 is low expression in esophageal cancer, and may participate in the occurrence and development of esophageal cancer by regulating GOLPH3.