Project description:We have found that thyroid hormones (THs), acting as soluble integrin αvβ3 ligands, activate growth-related signaling pathways in T-cell lymphomas (TCL). Specifically, TH-activated αvβ3 integrin signaling promotes TCL proliferation and angiogenesis, in part, via the up-regulation of VEGF.
Project description:We have found that thyroid hormones (THs), acting as soluble integrin αvβ3 ligands, activate growth-related signaling pathways in T-cell lymphomas (TCL). Specifically, TH-activated αvβ3 integrin signaling promotes TCL proliferation and angiogenesis, in part, via the up-regulation of VEGF. CUTLL1 cells were treated with T3- and T4-bound agarose or agarose alone for 24hrs. Total RNA was harvested from cells and used for expression profiling via RNA-seq.
Project description:Microarray analysis was carried out on Glioblastoma (GBM 10181360, GBM 021913 and U87 cells), Bladder cancer (JBV253), skin cancer (A375) and Acute Myelod Leukemia (AML) (KG1A and K562 cells) exposed to fb-PMT at 30 µM concentration. Our genome-wide microarray screens demonstrated that fb-PMT appears to exert its potent anticancer actions on human cancer cells through the molecular interference mechanism with multiple signaling pathways supporting growth and survival of leukemic cells. Notably, fb-PMT had a significant effect on different molecular pathways that contribute to the anticancer activity such as cell cycle control (MYC), survival and maintenance of stem cells (HIF1A; TFAP2C), essential features of the malignant phenotype (TWIST1; SNAI). Furthermore, the fb-PMT-induced significant transcriptional pathway’s activation includes RB1; IRF9; MAML1; RAP1A; and GATA4 pathways, which known to play an important role in anticancer activity. Finally, Consistent with our previous reports on the crosstalk between integrin αvβ3 and ERα which contributes to the induced proliferation of cancer cells, we found that fb-PMT interference with estrogen signaling. The αvβ3 agonist (thyroid hormone) was associated with increased phosphorylation and nuclear enrichment of estrogen receptor α (ERα).
Project description:Fibronectin (FN)-binding integrins control a variety of cellular responses through Rho GTPases. The FN-binding integrins, αvβ3 and α5β1, are known to induce different effects on cell morphology and motility. Here we report that FN-bound αvβ3 integrin, but not FN-bound α5β1 integrin, triggers the dissociation of the RhoA GEF Lfc (GEF-H1 in humans) from microtubules (MT), leading to the activation of RhoA, formation of stress fibres and maturation of focal adhesions (FAs). Conversely, loss of Lfc expression decreases RhoA activity, stress fibre formation and FA size, suggesting that Lfc is the major GEF downstream of FN-bound αvβ3 that controls RhoA activity. Mechanistically, FN-engaged αvβ3 integrin activates a kinase cascade involving MARK2/3, which in turn leads to phosphorylation of several phospho-sites on Lfc. In particular, S151 was identified as the main site involved in the regulation of Lfc localization and activity. Our findings indicate that activation of Lfc/RhoA is orchestrated in FN-adherent cells in an integrin-specific manner.
Project description:Fibronectin (FN)-binding integrins control a variety of cellular responses through Rho GTPases. The FN-binding integrins, αvβ3 and α5β1, are known to induce different effects on cell morphology and motility. Here we report that FN-bound αvβ3 integrin, but not FN-bound α5β1 integrin, triggers the dissociation of the RhoA GEF Lfc (GEF-H1 in humans) from microtubules (MT), leading to the activation of RhoA, formation of stress fibres and maturation of focal adhesions (FAs). Conversely, loss of Lfc expression decreases RhoA activity, stress fibre formation and FA size, suggesting that Lfc is the major GEF downstream of FN-bound αvβ3 that controls RhoA activity. Mechanistically, FN-engaged αvβ3 integrin activates a kinase cascade involving MARK2/3, which in turn leads to phosphorylation of several phospho-sites on Lfc. In particular, S151 was identified as the main site involved in the regulation of Lfc localization and activity. Our findings indicate that activation of Lfc/RhoA is orchestrated in FN-adherent cells in an integrin-specific manner
