ID 113048
Author
Amachi, Ryota Tokushima University
Oda, Asuka Tokushima University
Hanson, Derek Tokushima University
Iwasa, Masami Tokushima University
Kuroda, Yoshiaki Hiroshima University
Horikawa, Hideaki The University of Tokushima
Keywords
multiple myeloma
acidic microenvironment
HDAC
Sp1
DR4
Content Type
Journal Article
Description
Myeloma (MM) cells and osteoclasts are mutually interacted to enhance MM growth while creating acidic bone lesions. Here, we explored acid sensing of MM cells and its role in MM cell response to acidic conditions. Acidic conditions activated the PI3K-Akt signaling in MM cells while upregulating the pH sensor transient receptor potential cation channel subfamily V member 1 (TRPV1) in a manner inhibitable by PI3K inhibition. The acid-activated PI3K-Akt signaling facilitated the nuclear localization of the transcription factor Sp1 to trigger the expression of its target genes, including TRPV1 and HDAC1. Consistently, histone deacetylation was enhanced in MM cells in acidic conditions, while repressing a wide variety of genes, including DR4. Indeed, acidic conditions deacetylated histone H3K9 in a DR4 gene promoter and curtailed DR4 expression in MM cells. However, inhibition of HDAC as well as either Sp1 or PI3K was able to restore DR4 expression in MM cells suppressed in acidic conditions. These results collectively demonstrate that acid activates the TRPV1-PI3K-Akt-Sp1 signaling in MM cells while inducing HDAC-mediated gene repression, and suggest that a positive feedback loop between acid sensing and the PI3K-Akt signaling is formed in MM cells, leading to MM cell response to acidic bone lesions.
Journal Title
Oncotarget
ISSN
19492553
Publisher
Impact Journals, LLC
Volume
7
Issue
43
Start Page
70447
End Page
70461
Published Date
2016-09-10
Remark
This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC BY 3.0)(https://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
EDB ID
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Publisher
departments
Oral Sciences
University Hospital
Medical Sciences
Institute of Advanced Medical Sciences