[Retracted] Downregulation of matrix metalloproteinase 9 by small interfering RNA inhibits the tumor growth of ovarian epithelial carcinoma in vitro and in vivo.

Following the publication of this paper, the authors contacted the Editorial Office to request that the article be retracted on account of an inability to obtain consistent results after having repeated the experiments portrayed in Figs. 1B and 3B. Independently, it was drawn to the Editor's attention that certain of the western blotting data shown in these figures were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that these other articles were under consideration for publication at the same time as the above article was submitted for publication to Molecular Medicine Reports, the Editor has agreed to the authors' request that this article should be retracted from the Journal. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in Molecular Medicine Reports 12: 753­759, 2015; DOI: 10.3892/mmr.2015.3425].

Downregulation of matrix metalloproteinase 9 by small interfering RNA inhibits the tumor growth of ovarian epithelial carcinoma in vitro and in vivo.

Matrix metalloproteinase 9 (MMP-9) is upregulated in various types of malignancy, including human ovarian carcinomas. It promotes invasion, metastasis, growth and the survival of malignant cells. However, relatively little is known about the role of MMP9 in epithelial ovarian carcinoma. Therefore, the aim of the present study was to determine the effects of targeting this molecule on ovarian carcinoma progression. A plasmid, psi-MMP-9, carrying a short hairpin RNA against MMP-9 gene expression was constructed and transfected into the human ovarian cancer cell line SKOV3 using a human U6 promoter-driven DNA template approach to determine the effect of MMP-9 gene RNA interference (RNAi) on the proliferation, apoptosis, migration, invasion and tumorigenicity of the human ovarian carcinoma cells. The results demonstrated that siRNA-mediated knockdown of MMP-9 in the human ovarian cancer cell line SKOV3 inhibited cell proliferation, migration and invasion in vitro. The results also demonstrated that downregulation of MMP-9 led to cell apoptosis in SKOV3 cells, inhibited the expression of anti-apoptotic molecules, including B cell lymphoma-2, survivin and X-linked inhibitor of apoptosis protein, and enhanced the activity of capsase-3 and caspase-8. In addition, knockdown of MMP-9 inhibited tumorigenicity in nude mice. Taken together, MMP-9 gene RNAi in ovarian carcinoma cells inhibited proliferation, migration and invasion, induced cell apoptosis in vitro and suppressed tumor growth in nude mice. These results suggest that MMP-9 is an ovarian cancer-associated gene and is a potential target for therapeutic anti-cancer drugs.