scholarly journals ITGBL1 Is a Runx2 Transcriptional Target and Promotes Breast Cancer Bone Metastasis by Activating the TGFβ Signaling Pathway

2015 ◽  
Vol 75 (16) ◽  
pp. 3302-3313 ◽  
Author(s):  
Xiao-Qing Li ◽  
Xin Du ◽  
Dong-Mei Li ◽  
Peng-Zhou Kong ◽  
Yan Sun ◽  
...  
2020 ◽  
Vol 21 (3) ◽  
pp. 805 ◽  
Author(s):  
Shaolan Li ◽  
Yang Fan ◽  
Asako Kumagai ◽  
Emi Kawakita ◽  
Munehiro Kitada ◽  
...  

Dipeptidyl peptidase (DPP)-4, a molecular target of DPP-4 inhibitors, which are type 2 diabetes drugs, is expressed in a variety of cell types, tissues and organs. DPP-4 has been shown to be involved in cancer biology, and we have recently shown that a DPP-4 inhibitor promoted the epithelial mesenchymal transition (EMT) in breast cancer cells. The EMT is known to associate with chemotherapy resistance via the induction of ATP-binding cassette (ABC) transporters in cancer cells. Here, we demonstrated that deficiency in DPP-4 promoted chemotherapy resistance via the CXCL12/CXCR4/mTOR axis, activating the TGFβ signaling pathway via the expression of ABC transporters. DPP-4 inhibition enhanced ABC transporters in vivo and in vitro. Doxorubicin (DOX) further induced ABC transporters in DPP-4-deficient 4T1 cells, and the induction of ABC transporters was suppressed by either the CXCR4 inhibitor AMD3100, the mTOR inhibitor rapamycin or a neutralizing TGFβ (1, 2 and 3) antibody(N-TGFβ). Knockdown of snail, an EMT-inducible transcription factor, suppressed ABC transporter levels in DOX-treated DPP-4-deficient 4T1 cells. In an allograft mouse model, however, the effects of DOX in either primary tumor or metastasis were not statistically different between control and DPP-4-kd 4T1. Taken together, our findings suggest that DPP-4 inhibitors potentiate chemotherapy resistance via the induction of ABC transporters by the CXCL12/CXCR4/mTOR/TGFβ signaling pathway in breast cancer cells.


2021 ◽  
Author(s):  
Lin Zhang ◽  
Jingkun Qu ◽  
Yutao Qi ◽  
Yu-Wen Huang ◽  
Zhifen Zhou ◽  
...  

ABSTRACTBone metastasis is a frequent complication of breast cancer, occurring in about 50-70% of breast cancer patients with late-stage disease. The lack of effective therapy suggests that the precise molecular mechanisms underlying bone metastasis are still unclear. Enhancer of zeste homolog 2 (EZH2) is considered a breast cancer oncogene and its expression is correlated with metastasis of breast cancer, but its function in bone metastasis has not been well explored. Herein we report that EZH2 promotes osteolytic metastasis of breast cancer through regulating transforming growth factor beta (TGFβ) signaling, a key pathway in bone metastasis. Knocking down EZH2 decreases bone metastasis incidence and outgrowth in vivo. EZH2 induces cancer cell proliferation and osteoclast maturation, when breast cancer cells are co-cultured with osteoblasts and osteoclasts together in vitro. Mechanistically, EZH2 increases transcription of ITGB1, which encodes for integrin β1. Integrin β1 activates focal adhesion kinase (FAK), which phosphorylates TGFβ receptor type I (TGFβRI) at tyrosine 182, thus enhances the binding of TGFβRI to TGFβ receptor type II (TGFβRII), therefore activates Smad2 and increases parathyroid hormone-like hormone (PTHLH) expression. Clinically applicable FAK inhibitors but not EZH2 methyltransferase inhibitor effectively inhibits breast cancer bone metastasis in vivo. Overall, our data signify integrin β1-FAK as a new downstream effector of EZH2 in breast cancer cells, and EZH2-integrin β1-FAK axis cooperates with TGFβ signaling pathway to promote bone metastasis of breast cancer.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Ruixian Wu ◽  
Qian Li ◽  
Xiaohua Pei ◽  
Kefei Hu

The present study examined the effects of brucine on the OPG/RANKL/RANK signaling pathway for exploring the mechanism of brucine suppression of bone metastasis in breast cancer. MDA-MB-231 breast cancer cells and mouse osteoblast MC3T3-E1 cells were cocultured to mimic the breast cancer bone metastasis microenvironmentin vitro. qRT-PCR and Western blotting were used to detect the expressions of OPG and RANKL at the mRNA and protein levels, respectively, in brucine-treated cultures and they were compared to those in untreated cultures. We aimed to understand the effect of brucine on the entire OPG/RANKL/RANK signaling pathway after analyzing these effects. Results showed that brucine treatment significantly increased both the OPG mRNA/RANKL mRNA expression ratio and the OPG protein/RANKL protein ratio in cocultures compared to those in untreated cocultures (P<0.01). Brucine, therefore, plays a regulatory role in the OPG/RANKL/RANK signaling pathway, suggesting that it can indirectly control osteoclasts by regulating the expression and secretion of OPG and RANKL in osteoblast cells, thereby inhibiting the differentiation and bone resorption function of osteoclasts.


2008 ◽  
Vol 68 (S 01) ◽  
Author(s):  
C Schem ◽  
DO Bauerschlag ◽  
J Weimer ◽  
M Zhang ◽  
W Jonat ◽  
...  

2019 ◽  
Vol 19 (5) ◽  
pp. 667-676
Author(s):  
José R. Santin ◽  
Gislaine F. da Silva ◽  
Maria V.D. Pastor ◽  
Milena F. Broering ◽  
Roberta Nunes ◽  
...  

Background: It was recently demonstrated that the phthalimide N-(4-methyl-phenyl)-4- methylphthalimide (MPMPH-1) has important effects against acute and chronic pain in mice, with a mechanism of action correlated to adenylyl cyclase inhibition. Furthermore, it was also demonstrated that phthalimide derivatives presented antiproliferative and anti-tumor effects. Considering the literature data, the present study evaluated the effects of MPMPH-1 on breast cancer bone metastasis and correlated painful symptom, and provided additional toxicological information about the compound and its possible metabolites. Methods: In silico toxicological analysis was supported by in vitro and in vivo experiments to demonstrate the anti-tumor and anti-hypersensitivity effects of the compound. Results: The data obtained with the in silico toxicological analysis demonstrated that MPMPH-1 has mutagenic potential, with a low to moderate level of confidence. The mutagenicity potential was in vivo confirmed by micronucleus assay. MPMPH-1 treatments in the breast cancer bone metastasis model were able to prevent the osteoclastic resorption of bone matrix. Regarding cartilage, degradation was considerably reduced within the zoledronic acid group, while in MPMPH-1, chondrocyte multiplication was observed in random areas, suggesting bone regeneration. Additionally, the repeated treatment of mice with MPMPH-1 (10 mg/kg, i.p.), once a day for up to 36 days, significantly reduces the hypersensitivity in animals with breast cancer bone metastasis. Conclusion: Together, the data herein obtained show that MPMPH-1 is relatively safe, and significantly control the cancer growth, allied to the reduction in bone reabsorption and stimulation of bone and cartilage regeneration. MPMPH-1 effects may be linked, at least in part, to the ability of the compound to interfere with adenylylcyclase pathway activation.


Sign in / Sign up

Export Citation Format

Share Document