MMP-2 regulates Src activation via repression of the CHK/MATK tumor
suppressor in Osteosarcoma
Abstract
Doxorubicin, a first-line anticancer drug for osteosarcoma treatment,
has been the subject of recent research exploring the mechanisms behind
its chemoresistance and its ability to enhance cell migration at
sublethal concentrations. Matrix metalloproteinase-2 (MMP-2), a type IV
collagenase and zinc-dependent endopeptidase, is well-known for
degrading the extracellular matrix and promoting cancer metastasis. Our
previous work demonstrated that nuclear MMP-2 regulates ribosomal RNA
transcription via histone clipping, thereby controlling gene expression.
Additionally, MMP-2 activity is regulated by the non-receptor tyrosine
kinase and oncogene, Src, which plays a crucial role in cell adhesion,
invasion, and metastasis. Src kinase is primarily regulated by two
endogenous inhibitors: C-terminal Src kinase (Csk) and Csk homologous
kinase (CHK/MATK). In this study, we reveal that the MMP-2 gene acts as
an upstream regulator of Src kinase activity by suppressing its
endogenous inhibitor, CHK/MATK, in osteosarcoma cells. We also show that
enhanced osteosarcoma cell migration which is induced by sublethal
concentrations of doxorubicin can be overcome by inactivating the MMP-2
gene or overexpressing CHK/MATK. Our findings highlight the MMP-2 gene
as a promising additional target for combating cancer cell migration and
metastasis. This is due to its impact on the gene and protein expression
of the tumor suppressor CHK/MATK in osteosarcoma. By targeting the MMP-2
gene, we can potentially enhance the effectiveness of doxorubicin
treatment and reduce chemoresistance in osteosarcoma.