金刚藄胶乳中的三萜类成分及其对爱-巴病毒活性的抑制

大戟科植物金刚(艹綦)Euphorbia antiquo-rum L.生长于印度和斯里兰卡,具有多种药用价值。作者从该植物胶乳中分离鉴定了-新的三萜醇 antiquol C(2)和6个已知的三萜醇:大戟二烯醇(1)、antiquol B(3)、大戟醇(4)、lemmaphylla-7,21-dien-3β-ol(5)、isohelianol(6)和 camelliol(7)。

非鼻咽部T细胞淋巴瘤与EB病毒的相关性

目的：探讨EB病毒（EBV）感染与非鼻咽部T细胞淋巴瘤的关系。方法：用单克隆抗体UCHL-1、L26及EB病毒编码的潜在膜蛋白-1（LMP-1），免疫组化染色确定肿瘤的免疫表型及EB病毒转化蛋白的表达。采用原位杂交方法检测EBV编码的EBERs。结果：21例非鼻咽部T细胞淋巴瘤EBERs5例阳性的（23．8％），其中给内淋巴瘤3例，肺和胃肠淋巴瘤各1例。阳性细胞约占肿瘤细胞的10％～70％。5例EBERs阳性病例中仅1例表达LMP-1，为结内淋巴瘤。结论：非鼻咽部T细胞淋巴瘤可能与EBV的感染有关，LMP-1的阳性率较EBERs低。

Epigenetic changes in virus-associated human cancers

Epigenetics of human cancer becomes an area of emerging research direction due to a growing understanding ofspecific epigenetic pathways and rapid development of detection technologies. Aberrant promoter hypermethylation is aprevalent phenonmena in human cancers. Tumor suppressor genes are often hypermethylated due to the increasedactivity or deregulation of DNMTs. Increasing evidence also reveals that viral genes are one of the key players inregulating DNA methylation. In this review, we will focus on hypermethylation and tumor suppressor gene silencing andthe signal pathways that are involved, particularly in cancers closely associated with the hepatitis B virus, simian virus40 (SV40), and Epstein-Barr virus. In addition, we will discuss current technologies for genome-wide detection ofepigenetically regulated targets, which allow for systematic DNA hypermethylation analysis. The study of epigeneticchanges should provide a global view of gene profile in cancer, and epigenetic markers could be used for early detection,prognosis, and therapy of cancer.

E-cadherin and beta-catenin expression in Epstein-Barr virus-associated gastric carcinoma and their prognostic significance

AIM： To examine the role of E-cadherin and betacatenin in carcinogenesis and to assess their prognostic implication in Epstein-Barr virus-associated gastric carcinomas （EBV-GCs）. METHODS： We compared the frequency of E-cadherin and beta-catenin expression in 59 EBV-GCs and 120 non-EBV-GCs, and examined the association between patients＇ prognosis and the expressions of these proteins. RESULTS： Neither the cellular-membranous nor the cytoplasmic E-cadherin expression showed any difference between EBV-GCs and non-EBV-GCs. On the other hand, loss of membranous expression of beta- catenin occurred more frequently in non-EBV-GCs than EBV-GCs [odds ratio = 0.41; 950 confidence interval （CI）, 0.19-0.90]. Furthermore, the nuclear and/or cytoplosmic expression of beta-catenin was seen more frequently in EBV-GCs than non-EBV-GCs （odds ratio = 2.23; 95% CI, 0.97-5.09）, and was observed in a larger proportion of carcinoma cells of EBV-GCs than non-EBV-GCs （P = 0.024）. Survival analysis for non-EBV-GC revealed that lymph node metastasis was significantly associated with poor prognosis （P 〈 0.001）. Among EBV- GCs, the depth of invasion （P = 0.005）, lymph node metastasis （P = 0.004） and an intestinal type by Lauren classification （hazard ratio = 9.47; 95% CI, 2.67-33.6） were significantly associated with poor prognosis. On the other hand, nuclear and/or cytoplasmic expression of beta-catenin was associated with a better prognosis in patients with EBV-GC （hazard ratio = 0.32; 95% CI, 0.11-0.93）. CONCLUSION： We observed more frequent preservation of beta-catenin in cell membrane and accumulation in nuclei and/or cytoplasm in EBV-GCs than in non-EBV- GCs. Factors involved in the prognosis of EBV-GCs and non-EBV-GCs are different in the two conditions.

CONSTRUCTION OF HU-PBL/SCID CHIMERAS AND DEVELOPMENTOF EBV-RELATED LYMPHOMAS

Objective To construct hu-PBL/SCID chimeras and to investigate the development of lymphoma and oncogenicity of the Epstein-Barr virus (EBV). Methods Human peripheral blood lymphocytes (PBLs) were isolated from healthy adult donors and transplanted intraperitoneally into severe combined immunodeficient(SCID) mice. Mice with hu-PBL engraftment from healthy EBV seronegative donors were injected intraperitoneally with EBV-containing supernatant from suspension culture of B95-8 cell line (active infection), whereas mice receiving lymphocytes from healthy EBV seropositive donors were not re-infected with B95-8 derived EBV (latent infection). Pathological examination and molecular analysis were performed on experime-ntal animals and induced neoplasms. Results In the early stage of this experiment, 12 mice died of acute graft-versus-host disease, mortality was 34.3% (12/35 mice) with an average life span of 17.5 days. In 19 survival hu-PBL/SCID chimeric recipients from 12 healthy donors, tumor incidence was 84.2% (16/19 mice). The average survival time of tumor-bearing mice was 65.5 days. EBV-related neoplasms in SCID mice were nodular tumors with aggressive and fatal features. Histological morphology of tumors exhibited diffuse large cell lymphomas. Immunohistochemistry revealed that LCA (CD45) and L26 (CD20) were positive, but both PS1 (CD3) and UCHL-1 (CD45RO) were negative, and EBV products ZEBRA, LMP1, and EBNA2 were expressed in a small number of tumor cells. EB virus particles were seen in the nuclei of some tumor cells by electron microscopy, and EBV DNA could be amplified in the tumor tissues by PCR. In situ hybridization indicated that the nuclei of tumor cells contained human-specific Alu sequence. Conclusions EBV-induced tumors were human B-cell malignant lymphomas. We obtained direct causative evidence dealing with EBV-associated tumor deriving from normal human cells.

Epstein-Barr virus-associated gastric carcinoma in Kazakhstan

AIM: To investigate the incidence of Epstein-Barr virus-associated gastric cancer (EBV-GC) in Kazakhstan and to compare it with that in Russia, Western and Asian countries in order to evaluate the significance of epidemiopathologic and ethnic factors. METHODS: In situ hybridization (ISH) of EBV-encoded small RNA-1 (EBER-1) was used to identify the presence of EBER-1 signal in 139 formalin-fixed and paraffin-embedded GC tissues from Kazakhstan. RESULTS: EBER-1 expression was observed in the nuclei of 10% of the cases of GC (14/139), but not in the surrounding normal mucosa. The incidence of the diffuse type of EBV-GC was significantly higher in Kazakhstan (14%, 13/91) than that of the intestinal type (2%, 1/48). Furthermore, the incidence was significantly higher in males (14%, 12/89) than in females (3.7%, 2/53) from all countries. The overall incidence of EBV-GC increased from 6.7% in Asian countries to 8.7% in Russia, 10.1% in Kazakhstan and 16% in Western countries. CONCLUSION: Geographical differences in the incidence of EBV-GC may reflect the epidemiologic factors and/or dietary habits independent of histological type and sex.

CD21-independent Infection of Epstein-Barr Virus in Human Signet Ring Gastric Carcinoma Cell Line

To study the mechanism of infection of Epstein-Barr virus (EBV) in gastric carcinoma cells, the Akata and P3HR-1 strains of EBV were used as the test strains of viruses, and the signet ring cell line HSC-39 of gastric carcinoma cells was used as the target cells of infection. The virus-infected cell clones were isolated by limited dilution method. It was found that the EBV-encoded small RNA (EBER) could be detected in the infected cells. The Akata and P3HR-1 EBV infected parental cells and most of clones expressed EBNA1, but not EBNA2. Latent membrane protein (LMP-1) and LMP-2, and the Q promoter (p), but not the Cp/Wp for EBNA gene transcription was active in the infected parental cells as well as all the clones. Uninfected HSC-39 cells did not express CD21, however, Akata but not P3HR-1 EBV-infected clones expressed low level of CD21 mRNA. These results demonstrate that HSC-39 cells are susceptible to both EBV strains and EBV infects HSC-39 cells through the CD21-independent pathway. This study defines a signet ring type of gastric carcinoma cells line as a unique target cells for the study of EBV infection mechanism.