Allelic loss at 19q12 and Xq11-12 predict an adverse clinical outcome in patients with mucinous ovarian tumours of low malignant potential

High Ki-67 expression is significantly associated with poor prognosis of ovarian cancer patients: evidence from a meta-analysis

OBJECTIVE

The prognostic significance of Ki-67 expression in patients with ovarian cancer was controversial in various studies. Therefore, we carried out a meta-analysis to determine the prognostic significance of Ki-67 in ovarian cancer patients.

METHODS

We searched PubMed, Cochrane Library, EMBASE, Web of Knowledge, China National Knowledge Infrastructure database and WanFang digital database for eligible studies from January 1, 1990 to June 1, 2017. The pooled hazard ratios and 95% confidence intervals were calculated to assess the prognostic significance of Ki-67 expression for overall survival in ovarian cancer patients.

RESULTS

Finally, 38 eligible studies and 5004 ovarian cancer patients were included in the current study. The pooled hazard ratio was 1.35 (95% confidence interval 1.24-1.46, P = 0.001) for overall survival in ovarian cancer patients. The funnel plot bias was obviously asymmetrical and Egger's test also detected significant publication bias (P = 0.001). The Contour-enhanced funnel plot with trim-and-fill method supplemented 11 dummy studies to balance the funnel plot and nine new supplementary studies were in area with statistical significance. Sensitivity analysis and cumulative meta-analysis further demonstrated that the association between high Ki-67 expression and poor overall survival of ovarian cancer patients was stable and reliable.

CONCLUSIONS

High Ki-67 expression is significantly related to poor overall survival and may serve as a prognostic biomarker for ovarian cancer patients.

Human endogenous retroviral K element encodes fusogenic activity in melanoma cells

INTRODUCTION AND HYPOTHESIS

Nuclear atypia with features of multi nuclei have been detected in human melanoma specimens. We found that the K type human endogenous retroviral element (HERV K) is expressed in such cells. Since cellular syncytia can form when cells are infected with retroviruses, we hypothesized that HERV K expressed in melanoma cells may contribute to the formation of multinuclear atypia cells in melanoma.

EXPERIMENTS AND RESULTS

We specifically inhibited HERV K expression using RNA interference (RNAi) and monoclonal antibodies and observed dramatic reduction of intercellular fusion of cultured melanoma cells. Importantly, we identified loss of heterozygosity (LOH)of D19S433 in a cell clone that survived and proliferated after cell fusion.

CONCLUSION

Our results support the notion that proteins encoded by HERV K can mediate intercellular fusion of melanoma cells, which may generate multinuclear cells and drive the evolution of genetic changes that provide growth and survival advantages.

Ovarian epithelial tumors of low malignant potential: Are they precursors of ovarian carcinoma?

Ovarian tumors of low malignant potential (LMP) are intermediate between benign adenoma and frank ovarian carcinoma, and are characterized by the absence of destructive stromal invasion, or microinvasion. If LMP did not develop into invasive carcinoma, then a minimally invasive simple treatment could be chosen. However, histological diagnosis cannot completely predict the prognosis of patients with ovarian tumors. It was found that mucinous LMP is most frequent in Japan, whereas serous LMP is the most common in Western countries. Mucinous LMP with loss of heterozygosity (LOH) at chromosomes 5q14-21 and 17q11.2, and serous LMP were suggested to be precursor lesions of ovarian carcinomas. Follow-up study revealed that patients with mucinous LMP who had LOH at 19q12 and/or Xq11-12 were at the greatest risk of progression. It is concluded that molecular genetic analysis such as LOH study could predict prognosis and aid in treatment decision-making. The present review describes molecular genetic changes of LMP and presents problems on LMP that remain to be elucidated.