Da-Feng Ye

Proportion of CD4+CD25+ Regulatory T Cell is Increased in the Patients with Ovarian Carcinoma

Objective: To study the frequency of the CD4+CD25+ regulatory T cells (Tregs) in the patients with ovarian carcinoma and its possible mechanism. Methods: The percentages of CD4+CD25+ Tregs in the peripheral blood lymphocytes (PBLs), tumor infiltrating lymphocytes (TILs) and tumor associated lymphocytes (TALs) from 13 patients with ovarian carcinoma and in the PBLs from 14 healthy women were determined by flow cytometry. The expression of CD69 on CD4+PBLs from the patients was detected. PBLs from healthy women were cultured in complete RPMI 1640 containing the supernatant from SKOV3 cell line with or without PHA (phytohemagglutinin) stimulation for 72 hours, then the percentage of CD4+CD25+ T cells was detected. Results: CD4+CD25+ Tregs in the PBLs from patients with ovarian carcinoma were significantly increased compared with those from the control. The percentage of CD4+CD25+ Tregs in TILs was higher than that in PBLs and TALs from the patients, but not significantly. The expression of CD69 on CD4+PBLs from the patients was negative. The percentages of CD4+CD25+ T cells in PBLs cultured with SKOV3 supernatant elevated significantly compared with those without supernatant whether PHA was added or not (P = 0.001 and 0.001, respectively). Conclusion: There is an increasing of the proportion of CD4+CD25+ Tregs in PBLs, TILs and TALs of the patients with ovarian carcinoma, which probably results from up-regulation of soluble factor secreted by ovarian carcinoma cells.

Lack of mutation in tumour-suppressor gene p53 in gestational trophoblastic tumours.

The objectives of this study were to better our understanding of the carcinogenesis of gestational trophoblastic tumours and to investigate the possible presence of mutational alteration of the p53 tumour-suppressor gene in these tumours. Amplification-based direct DNA sequencing was performed on 14 hydatidiform moles, six invasive moles, eight choriocarcinomas and ten normal early placental tissues. No mutation in exons 5-8 was detected in any of these 38 tissue specimens. These results suggest that a mutation in p53 tumour suppressor either does not exist or is a very rare event in gestational trophoblastic tumours. The gestational trophoblastic tumours probably involve a tumour-suppressor gene other than p53 gene or may follow a completely different pathway to their malignant phenotype.

PTEN promoter methylation and protein expression in normal early placentas and hydatidiform moles.

Objective: To investigate the relationship between PTEN promoter methylation and protein expression, and the possible involvement of the PTEN gene in development of gestational trophoblasts and the pathogenesis of hydatidjform moles. Methods: DNA was extracted from choria of normal early placentas, partial hydatidtform moles, complete hydatidiform moles, and invasive moles, and overdigested by methylation-sensitive endonuclease HpaII. The PTEN promoter was amplifcated by polymerase chain reaction. PTEN protein expression was detected by immunohistochemistry. Results: In partial and complete hydatidiform moles, the PTEN promoter methylation rate was significantly higher than in early placentas (72%, 59.4%, 14.3%; P = .000, .002, respectively), and the PTEN protein expression rate was significantly lower than in early placentas (9.1%, 4.5%, 90.5%; P = .000, .000, respectively). However, partial hydatidiform moles, complete hydatidiform moles, and invasive moles were not significant different in terms of PTEN promoter methylation and protein expression. Conclusions: These findings suggest that the regulation of PTEN expression may play an important role in the development of the early gestational trophoblast and in the pathogenesis of hydatidiform mole, but not in its malignant transformation.

Protein expression levels of excision repair cross-complementation group 1 and xeroderma pigmentosum D correlate with response to platinum-based chemotherapy in the patients with advanced epithelial ovarian cancer

This study was undertaken to examine whether there is an association between excision repair cross-complementation group 1 (ERCC1) and xeroderma pigmentosum D (XPD) protein expression levels and response to platinum-based chemotherapy in epithelial ovarian cancer (EOC). The study cohort consisted of 91 consecutive patients suffering from stage III or IV disease of primary EOC from 1999 to 2004 at the Womens Hospital, School of Medicine, Zhejiang University. There were 36 sensitive cases of serous ovarian cancer, 27 resistant cases of serous ovarian cancer, 15 cases of clear cell cancer, and 13 cases with serous ovarian cancer receiving neoadjuvant chemotherapy. The ovarian tissue microsections were stained by standard immunohistochemical techniques to show ERCC1 and XPD protein expression levels. In resistance group of serous ovarian cancer, ERCC1 and XPD protein expression levels were significantly higher than those of sensitivity group, and after receiving neoadjuvant chemotherapy, they showed 23% and 32% higher than before. Meanwhile, their levels of clear cell cancer group were significantly higher than serous ovarian cancer groups. Upregulation of ERCC1 and XPD protein expression was associated with resistance process to platinum-based chemotherapy in advanced EOC. This study provided evidence that differences of nucleotide excision repair–related genes expression may have an effect on the observed differences in clinical behavior of EOC

Interleukin-7 and suppression of local peritoneal immunity in ovarian carcinoma

Objectives: To investigate the epithelial ovarian carcinoma (EOC) secretion of interleukin‐7 (IL‐7). Methods: Levels of IL‐7 were assayed by enzyme‐linked immunoadsorbent assay and IL‐7 mRNA, and protein expression in tissues and cell lines were detected by RT‐PCR and immunohistochemistry. Results: The median serum IL‐7 level in patients with EOC (32 cases; 32.49 pg/ml) was significantly higher than that of patients with benign tumors (16 cases; 7.59 pg/ml) and healthy women (16 cases; 10.64 pg/ml) (P<0.05). The median peritoneal fluid IL‐7 level in patients with EOC (17.39 pg/ml) was slightly higher than that of patients with benign tumors (14.09 pg/ml), but not significantly so (P>0.05). There were positive correlations between the serum and peritoneal fluid IL‐7 levels in both ovarian cancer and benign group (P<0.05, both). Only two EOC specimens expressed IL‐7 mRNA, and no IL‐7 protein positive was found in any specimens. Conclusions: Epithelial ovarian carcinoma cells rarely express IL‐7, and IL‐7 levels are decreased in the ascitic fluid of patients with EOC.

Ovarian Carcinoma Cells Effectively Inhibit Differentiation and Maturation of Dendritic Cells Derived from Hematopoietic Progenitor Cells In Vitro

Loco-regional dissemination of ovarian carcinoma is associated with immunosuppression of the peritoneal cavity. One marked characteristic of the peritoneal immunity in this disease is the defective function of dendritic cells (DCs). In this study, the affect of ovarian carcinoma cells on DCs derived from hematopoetic progenitor cells was observed. The study demonstrated that the expansion, phenotype, and function of DCs generated from CD34+ precursors were significantly altered by the supernatant secreted by ovarian carcinoma cells, and this effect could be partly explained by tumoral overproduction of Vascular Endothelial Growth Factor (VEGF). The results indicated that a role of ovarian carcinoma cells in the differentiation and function of DCs could be associated with the immunosuppression and development of ovarian carcinoma.

Mismatch repair gene promoter methylation and expression in hydatidiform moles

MethodsIn this study, to investigate the significance of mismatch repair genes (MMR) promoter methylation and expression in the pathogenesis and malignant transformation of hydatidiform moles, we assayed promoter methylation and protein expression of the MMR genes hMLH1 and hMSH2 in gestational trophoblastic diseases (GTDs). DNA was extracted from normal placentas, partial hydatidiform moles, complete hydatidiform moles, and invasive moles, over-digested by methylation-sensitive endonuclease Hpa II, and then the promoters were amplificated by polymerase chain reaction. The protein expression was detected by immunohistochemistry.Results In the normal placentas, neither hMLH1 nor hMSH2 promoter methylation was detected. Expression of hMLH1 and hMSH2 in cytotrophoblasts was strongly positive. In partial hydatidiform moles and complete hydatidiform moles, hMLH1 and hMSH2 promoter methylation rates were significantly higher than that of normal placentas (P=0.000), and the protein expression in cytotrophoblasts was significantly lower (P=0.000). In the invasive moles, hMLH1 and hMSH2 promoter methylation was not significantly different compared with the partial hydatidiform moles and complete hydatidiform moles (P>0.05). Expression of hMLH1 in the invasive moles (54.5%, 6 out of 11) was not significantly different compared with the partial hydatidiform moles and complete hydatidiform moles (P>0.05). But hMSH2 expression in the invasive moles (36.5%, 4 out of 11) was weaker than that in complete hydatidiform moles (P=0.044). Promoter methylation and less expression of hMSH2 were correlated in complete hydatidiform moles (P=0.001) and invasive moles (P=0.039).Conclusions These results indicated that strong expression of hMLH1 and hMSH2 in the cytotrophoblasts of normal placentas may maintain genome stability. Promoter methylation and down-regulation of the expression of hMLH1 and hMSH2 are probably involved in the pathogenesis of hydatidiform moles.