scholarly journals Wnt signaling and Loxl2 promote aggressive osteosarcoma

Cell Research ◽  
2020 ◽  
Vol 30 (10) ◽  
pp. 885-901
Author(s):  
Kazuhiko Matsuoka ◽  
Latifa Bakiri ◽  
Lena I. Wolff ◽  
Markus Linder ◽  
Amanda Mikels-Vigdal ◽  
...  

Abstract Osteosarcoma (OS) is the most frequent primary malignant bone tumor in urgent need of better therapies. Using genetically modified mouse models (GEMMs), we demonstrate that Wnt signaling promotes c-Fos-induced OS formation via the actions of the collagen-modifying enzyme Loxl2. c-Fos/AP-1 directly regulates the expression of the Wnt ligands Wnt7b and Wnt9a in OS cells through promoter binding, and Wnt7b and Wnt9a in turn promote Loxl2 expression in murine and human OS cells through the transcription factors Zeb1 and Zeb2. Concordantly, inhibition of Wnt ligand secretion by inactivating the Wnt-less (Wls) gene in osteoblasts in c-Fos GEMMs either early or in a therapeutic setting reduces Loxl2 expression and progression of OS. Wls-deficient osteosarcomas proliferate less, are less mineralized and are enriched in fibroblastic cells surrounded by collagen fibers. Importantly, Loxl2 inhibition using either the pan-Lox inhibitor BAPN or a specific inducible shRNA reduces OS cell proliferation in vitro and decreases tumor growth and lung colonization in murine and human orthotopic OS transplantation models. Finally, OS development is delayed in c-Fos GEMMs treated with BAPN or with specific Loxl2 blocking antibodies. Congruently, a strong correlation between c-FOS, LOXL2 and WNT7B/WNT9A expression is observed in human OS samples, and c-FOS/LOXL2 co-expression correlates with OS aggressiveness and decreased patient survival. Therefore, therapeutic targeting of Wnt and/or Loxl2 should be considered to potentiate the inadequate current treatments for pediatric, recurrent, and metastatic OS.

2019 ◽  
Vol 139 (3) ◽  
pp. 503-526 ◽  
Author(s):  
Grant T. Corbett ◽  
Zemin Wang ◽  
Wei Hong ◽  
Marti Colom-Cadena ◽  
Jamie Rose ◽  
...  

AbstractNeurodegenerative diseases are an enormous public health problem, affecting tens of millions of people worldwide. Nearly all of these diseases are characterized by oligomerization and fibrillization of neuronal proteins, and there is great interest in therapeutic targeting of these aggregates. Here, we show that soluble aggregates of α-synuclein and tau bind to plate-immobilized PrP in vitro and on mouse cortical neurons, and that this binding requires at least one of the same N-terminal sites at which soluble Aβ aggregates bind. Moreover, soluble aggregates of tau, α-synuclein and Aβ cause both functional (impairment of LTP) and structural (neuritic dystrophy) compromise and these deficits are absent when PrP is ablated, knocked-down, or when neurons are pre-treated with anti-PrP blocking antibodies. Using an all-human experimental paradigm involving: (1) isogenic iPSC-derived neurons expressing or lacking PRNP, and (2) aqueous extracts from brains of individuals who died with Alzheimer’s disease, dementia with Lewy bodies, and Pick’s disease, we demonstrate that Aβ, α-synuclein and tau are toxic to neurons in a manner that requires PrPC. These results indicate that PrP is likely to play an important role in a variety of late-life neurodegenerative diseases and that therapeutic targeting of PrP, rather than individual disease proteins, may have more benefit for conditions which involve the aggregation of more than one protein.


Oncogene ◽  
2012 ◽  
Vol 32 (7) ◽  
pp. 883-893 ◽  
Author(s):  
T Jardé ◽  
R J Evans ◽  
K L McQuillan ◽  
L Parry ◽  
G J Feng ◽  
...  

2019 ◽  
Vol 5 (10) ◽  
pp. eaaw3896 ◽  
Author(s):  
Rui Li ◽  
Sien Lin ◽  
Meiling Zhu ◽  
Yingrui Deng ◽  
Xiaoyu Chen ◽  
...  

Noncanonical Wnt signaling in stem cells is essential to numerous developmental events. However, no prior studies have capitalized on the osteoinductive potential of noncanonical Wnt ligands to functionalize biomaterials in enhancing the osteogenesis and associated skeleton formation. Here, we investigated the efficacy of the functionalization of biomaterials with a synthetic Wnt5a mimetic ligand (Foxy5 peptide) to promote the mechanosensing and osteogenesis of human mesenchymal stem cells by activating noncanonical Wnt signaling. Our findings showed that the immobilized Wnt5a mimetic ligand activated noncanonical Wnt signaling via the up-regulation of Disheveled 2 and downstream RhoA-ROCK signaling, leading to enhanced intracellular calcium level, F-actin stability, actomyosin contractility, and cell adhesion structure development. This enhanced mechanotransduction in stem cells promoted the in vitro osteogenic lineage commitment and the in vivo healing of rat calvarial defects. Our work provides valuable guidance for the developmentally inspired design of biomaterials for a wide array of therapeutic applications.


2016 ◽  
Author(s):  
Annika Jacobsen ◽  
Nika Heijmans ◽  
Folkert Verkaar ◽  
Martine J. Smit ◽  
Jaap Heringa ◽  
...  

The Wnt/β-catenin signaling pathway is important for multiple developmental processes and tissue maintenance in adults. Consequently, deregulated signaling is involved in a range of human diseases including cancer and developmental defects. A better understanding of the intricate regulatory mechanism and effect of physiological (active) and pathophysiological (hyperactive) WNT signaling is important for predicting treatment response and developing novel therapies. The constitutively expressed CTNNB1 (commonly and hereafter referred to as β-catenin) is degraded by a destruction complex, composed of amongst other AXIN1 and GSK3. The destruction complex is inhibited during active signaling leading to β-catenin stabilization and induction of β-catenin/TCF target genes. In this study we investigated the mechanism and effect of β-catenin stabilization during active and hyperactive WNT signaling in a combined in silico and in vitro approach. We constructed a Petri net model of Wnt/β-catenin signaling including main players from the plasma membrane (WNT ligands and receptors), cytoplasmic effectors and the downstream negative feedback target gene AXIN2. We simulated the model with active (i.e. WNT stimulation) and hyperactive (i.e. GSK3 inhibition) signaling, which led to the following observations: 1) A dose- and time-dependent response was observed for both WNT stimulation and GSK3 inhibition. 2) The Wnt-pathway activity was 2-fold higher for GSK3 inhibition compared to WNT stimulation. Both of these observations were corroborated by TCF/LEF luciferase reporter assays. Using this experimentally validated model we simulated the effect of the negative feedback regulator AXIN2 upon WNT stimulation and observed an attenuated β-catenin stabilization. We furthermore simulated the effect of APC inactivating mutations, yielding a stabilization of β-catenin levels comparable to the Wnt-pathway activities observed in colorectal and breast cancer. Our model can be used for further investigation and viable predictions of the role of Wnt/β-catenin signaling in oncogenesis and development.


2006 ◽  
Vol 175 (4S) ◽  
pp. 466-466
Author(s):  
Jill A. Macoska ◽  
Lesa Begley ◽  
Christine Monteleon ◽  
James W. MacDonald ◽  
Rajal B. Shah

1982 ◽  
Vol 54 (4) ◽  
pp. 763-768 ◽  
Author(s):  
Ronald E. Allen ◽  
Gail Robinson ◽  
Matthew J. Parsons ◽  
Robert A. Merkel ◽  
William T. Magee

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhengchuan Zhang ◽  
Ruogu Xu ◽  
Yang Yang ◽  
Chaoan Liang ◽  
Xiaolin Yu ◽  
...  

Abstract Background Micro/nano-textured hierarchical titanium topography is more bioactive and biomimetic than smooth, micro-textured or nano-textured titanium topographies. Bone marrow mesenchymal stem cells (BMSCs) and exosomes derived from BMSCs play important roles in the osseointegration of titanium implants, but the effects and mechanisms of titanium topography on BMSCs-derived exosome secretion are still unclear. This study determined whether the secretion behavior of exosomes derived from BMSCs is differently affected by different titanium topographies both in vitro and in vivo. Results We found that both micro/nanonet-textured hierarchical titanium topography and micro/nanotube-textured hierarchical titanium topography showed favorable roughness and hydrophilicity. These two micro/nano-textured hierarchical titanium topographies enhanced the spreading areas of BMSCs on the titanium surface with stronger promotion of BMSCs proliferation in vitro. Compared to micro-textured titanium topography, micro/nano-textured hierarchical titanium topography significantly enhanced osseointegration in vivo and promoted BMSCs to synthesize and transport exosomes and then release these exosomes into the extracellular environment both in vitro and in vivo. Moreover, micro/nanonet-textured hierarchical titanium topography promoted exosome secretion by upregulating RAB27B and SMPD3 gene expression and micro/nanotube-textured hierarchical titanium topography promoted exosome secretion due to the strongest enhancement in cell proliferation. Conclusions These findings provide evidence that micro/nano-textured hierarchical titanium topography promotes exosome biogenesis and extracellular secretion for enhanced osseointegration. Our findings also highlight that the optimized titanium topography can increase exosome secretion from BMSCs, which may promote osseointegration of titanium implants.


2002 ◽  
Vol 266 (4) ◽  
pp. 223-228 ◽  
Author(s):  
Seung Yup Ku ◽  
Y. M. Choi ◽  
Chang Suk Suh ◽  
Seok Hyun Kim ◽  
Jung Gu Kim ◽  
...  

Oncogene ◽  
2021 ◽  
Author(s):  
Jian Chen ◽  
Risi Na ◽  
Chao Xiao ◽  
Xiao Wang ◽  
Yupeng Wang ◽  
...  

Abstract5-Fluorouracil (5-FU)-based chemotherapy is the first-line treatment for colorectal cancer (CRC) but is hampered by chemoresistance. Despite its impact on patient survival, the mechanism underlying chemoresistance against 5-FU remains poorly understood. Here, we identified serine hydroxymethyltransferase-2 (SHMT2) as a critical regulator of 5-FU chemoresistance in CRC. SHMT2 inhibits autophagy by binding cytosolic p53 instead of metabolism. SHMT2 prevents cytosolic p53 degradation by inhibiting the binding of p53 and HDM2. Under 5-FU treatment, SHMT2 depletion promotes autophagy and inhibits apoptosis. Autophagy inhibitors decrease low SHMT2-induced 5-FU resistance in vitro and in vivo. Finally, the lethality of 5-FU treatment to CRC cells was enhanced by treatment with the autophagy inhibitor chloroquine in patient-derived and CRC cell xenograft models. Taken together, our findings indicate that autophagy induced by low SHMT2 levels mediates 5-FU resistance in CRC. These results reveal the SHMT2–p53 interaction as a novel therapeutic target and provide a potential opportunity to reduce chemoresistance.


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