Mammalian diaphanous-related formin 1 is required for motility and invadopodia formation in human U87 glioblastoma cells

Abstract

Abstract. Characterized by invasive growth and infiltrative dissemination, glioma is poorly diagnosed and prognosed at present. The mammalian diaphanous-related formin 1 (mDRF1), which is involved in a number of actin-related biological processes, has been found to participate in the process of invasion and metastasis in human breast cancer cells and to show abnormal expression under pathological conditions. However, the role of mDRF1 in glioma is not clear. In this study, we carried out a comprehensive analysis of the effects of mDRF1 on human glioma. We used siRNA to knock down mDRF1 expression in highly invasive U87 malignant glioma (MG) cells and examined the changes in cell proliferation, apoptosis, invasion and migration. Atomic force microscopy was used to examine invadopodia formation. Immunohistochemical and immunocytochemical assays were used to analyze the cellular localization and the expression levels of mDRF1 in human glioma tissue and in the U87 MG cells. Following the transfection of U87 MG cells with siRNA-mDRF1, their in vitro proliferation was significantly decreased, apoptosis was markedly increased, and invasion and metastasis were significantly inhibited. The results from atomic force microscopy revealed that invadopodia were formed at leading the edge of the U87 MG cells. However, following the silencing of mDRF1 by siRNA, the edge of the cells became smooth and the invadopodia disappeared. For in vivo experiments, nude mice were transplanted with tumor cells and then treated with siRNA-mDRF1. The results revealed that treatment with siRNA-mDRF1 significantly inhibited tumor growth and led to a decrease in the weight of the transplanted tumor. In conclusion, our data demonstrate that mDRF1 is highly expressed in human glioma tissue. The knockdown of mDRF1 in U87 MG cells led to a sharp decline in their invasive and metastatic ability, which effectively reduced the spread of glioma cells into the surrounding areas. To our knowledge, this is the first report showing that mDRF1 is a promising target for the treatment of malignant gliomas.

Invasive Cell Fate Requires G1 Cell-Cycle Arrest and Histone Deacetylase-Mediated Changes in Gene Expression

“…We also found that two additional MMPs expressed in the AC, zmp-3 and zmp-6 , were dependent on nhr-67 (Figure 4A and 4B). Finally, we examined the expression of actin regulators that promote invasive cellular behavior (Li et al, 2014; Wang et al, 2014). We found that AC expression of the actin regulators exc-6 (formin) and unc-34 (Ena/VASP) was dependent on NHR-67 activity, as RNAi depletion of nhr-67 resulted in reduced expression of exc-6 and unc-34 GFP transcriptional reporters (Figure 4A and 4B).…”

RTVP-1 regulates glioma cell migration and invasion via interaction with N-WASP and hnRNPK

“…In parallel to the induction of cell invasion and ECM degradation by RTVP-1 we also found that RTVP-1 induced the formation of podosomes and invadopodia in glioma cells. In recent years it has become clear that invadopodia have an important role in the invasion of glioma [ 30 ], and several proteins which are involved in the formation of invadopodia in glioma cells have been further explored as potential therapeutic targets such as synaptojanin [ 42 ], diaphanous-related formin 1 [ 43 ], the small GTPase RhoG [ 44 ] and CRN2 [ 45 ].…”

Matrix metalloproteinase-2 regulates MDA-MB-231 breast cancer cell invasion induced by active mammalian diaphanous-related formin 1

“…It has been reported that an actin-binding protein, cortactin, modulates the secretion and membrane expression of invadopodium-associated MMPs, including MMP-2 and MMP-9 in various cell types, such as vascular smooth muscle cells, head and neck squamous cell carcinomas, and breast cancer cells (22). As knockdown of mDia1 expression also reduces cortactin expression in malignant glioma cells (23), it is possible that mDia1 modulates MMP-2 and MMP-9 secretion via regulation of cortactin expression. In addition, results from the present study demonstrate that expression of MMP-2 is associated with breast cancer cell invasion induced by mDia1-CA (Fig.…”