Expression analysis of selected miR-206 targets from the transforming growth factor-beta signaling pathway in breast cancer
JOURNAL OF CELLULAR BIOCHEMISTRY
Authors: Seifi-Alan, Mahnaz; Dianatpour, Ali; Geranpayeh, Lobat; Mirfakhraie, Reza; Omrani, Mir D.; Ghafouri-Fard, Soudeh
Abstract
Breast cancer as a molecularly heterogeneous malignancy is associated with dysregulation of several signaling pathways, including transforming growth factor-beta (TGF-beta) signaling. On the other hand, several recent studies have demonstrated the role of microRNAs (miRNAs) in breast cancer pathogenesis. In the current study, we performed a computerized search to find miR-206 target genes that are functionally linked to the TGF-beta signaling pathway. We selected LEF1, Smad2, and Snail2 genes to assess their expression in 65 breast cancer samples and their adjacent noncancerous tissues (ANCTs) in correlation with expression levels of miR-206 as well as clinicopathological characteristics of patients. miR-206 was significantly downregulated in (Estrogen receptor) ER-positive breast cancer samples compared with their corresponding ANCTs. Association analysis between expression levels of genes and demographic features of patients showed significant association between expressions of SMAD2 and LEF1 genes and body mass index (P values of 0.03 and 0.02, respectively). miR-206 low-expression levels were associated with TNM stage, mitotic rate, and lymph node involvement (P values of 0.02, 0.01, and 0.01 respectively). In addition, SMAD2 high-expression levels were associated with HER2 status (P = 0.02). Consequently, our data highlight the role of TGF-beta signaling dysregulation in the pathogenesis of breast cancer and warrant further evaluation of miRNAs and messenger RNA coding genes in this pathway to facilitate detection of cancer biomarkers and therapeutic targets.
Homeobox protein MSX-1 inhibits expression of bone morphogenetic protein 2, bone morphogenetic protein 4, and lymphoid enhancer-binding factor 1 via Wnt/-catenin signaling to prevent differentiation of dental mesenchymal cells during the late bell stage
EUROPEAN JOURNAL OF ORAL SCIENCES
Authors: Feng, Xiao-Yu; Wu, Xiao-Shan; Wang, Jin-Song; Zhang, Chun-Mei; Wang, Song-Lin
Abstract
Homeobox protein MSX-1 (hereafter referred to as MSX-1) is essential for early tooth-germ development. Tooth-germ development is arrested at bud stage in Msx1 knockout mice, which prompted us to study the functions of MSX-1 beyond this stage. Here, we investigated the roles of MSX-1 during late bell stage. Mesenchymal cells of the mandibular first molar were isolated from mice at embryonic day (E)17.5 and cultured invitro. We determined the expression levels of -catenin, bone morphogenetic protein 2 (Bmp2), Bmp4, and lymphoid enhancer-binding factor 1 (Lef1) after knockdown or overexpression of Msx1. Our findings suggest that knockdown of Msx1 promoted expression of Bmp2, Bmp4, and Lef1, resulting in elevated differentiation of odontoblasts, which was rescued by blocking the expression of these genes. In contrast, overexpression of Msx1 decreased the expression of Bmp2, Bmp4, and Lef1, leading to a reduction in odontoblast differentiation. The regulation of Bmp2, Bmp4, and Lef1 by Msx1 was mediated by the Wnt/-catenin signaling pathway. Additionally, knockdown of Msx1 impaired cell proliferation and slowed S-phase progression, while overexpression of Msx1 also impaired cell proliferation and prolonged G1-phase progression. We therefore conclude that MSX-1 maintains cell proliferation by regulating transition of cells from G1-phase to S-phase and prevents odontoblast differentiation by inhibiting expression of Bmp2, Bmp4, and Lef1 at the late bell stage via the Wnt/-catenin signaling pathway.