Abstract
Introduction Osteosarcoma (OS) is one of the most common bone neoplasms in
adolescents. Notable short- and long-term toxic effects of OS chemotherapy
regimens have been reported. Hence, new chemotherapeutic agents with the ability
to potentiate OS chemotherapy drugs and protect non-tumorous tissues are
required.
Methods Saos-2 cells were treated with Methotrexate (MTX) and Quercetin
(Que) (a polyphenolic flavonoid with anti-tumor effects) alone and in
combination. MTT assay was performed to investigate the cytotoxicity of the
drugs. Moreover, apoptosis-involved genes, including miR-223, p53,
BCL-2, CBX7, and CYLD expression were analyzed via qRT-PCR. Annexin
V-FITC/PI kit was employed to assess the apoptosis rate.
Results The MTT results showed that Que increases MTX cytotoxicity on OS
cells. The measured IC50s are 142.3 µM for QUE and
13.7 ng/ml for MTX. A decline in MTX IC50 value was observed
from 13.7 ng/ml to 8.45 ng/ml in the presence of
Que. Moreover, the mRNA expression outcomes indicated that the combination
therapy significantly up-regulates the tumor suppressor genes, such as p53,
CBX7, and CYLD, and declines anti-apoptotic genes BCL-2 and miR-223, which can
lead to proliferation inhibition and apoptosis inducement. Furthermore, the
apoptosis rate increased significantly from 6.03% in the control group
to 38.35% in Saos-2 cells that were treated with the combination of MTX
and Que.
Conclusion Que, with the potential to boost the anticancer activity of MTX
on Saos-2 cancer cells through proliferation inhibition and apoptosis induction,
is a good candidate for combination therapy.
Key words
Osteosarcoma - combination therapy - Methotrexate - Quercetin - miR-223 - apoptosis
