%0 Journal Article %T MiRNA-26b inhibits proliferation by targeting PTGS2 in breast cancer %A Jia Li %A Xiangjie Kong %A Junfeng Zhang %A Qifeng Luo %A Xiaoyu Li %A Lin Fang %J Cancer Cell International %D 2013 %I BioMed Central %R 10.1186/1475-2867-13-7 %X Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to determine the expression level of miR-26b in 38 breast cancer specimens and adjacent normal breast tissues. MTT assays were conducted to explore the impact of miR-26b overexpression on the proliferation of human MDA-MB-231 breast cancer cells. Luciferase reporter assays were employed to validate regulation of a putative target of miR-26b. The effect of modulating miR-26b on endogenous levels of this target were subsequently confirmed via qRT-PCR and Western blot.MiR-26b expression was relatively decreased in breast cancer specimens compared with adjacent normal tissues (P<0.01). Overexpression of miR-26b suppressed MDA-MB-231 cell growth. Luciferase assays using a reporter carrying a putative miR-26b target site in the 3[prime] untranslated region of PTGS2 revealed that miR-26b directly targets PTGS2. Overexpression of miR-26b led to downregulation of PTGS2 at the mRNA and protein level, as assessed by qRT-PCR and Western blot. Targeted knockdown of PTGS2 by siRNA significantly inhibited the proliferation of MDA-MB-231 breast cancer cells.MiR-26b may act as a tumor suppressor in breast cancer. The overexpression of miR-26b inhibits cellular growth by targeting PTGS2, suggesting its use as a potential therapeutic target for breast cancer. %U http://www.cancerci.com/content/13/1/7/abstract