Related Experiment Video
Updated: Apr 26, 2026
Cytotoxic Efficacy of Photodynamic Therapy in Osteosarcoma Cells In Vitro
Published on: March 18, 2014
Isoalantolactone inhibits constitutive NF-κB activation and induces reactive oxygen species-mediated apoptosis in
Weihua Di1, Muhammad Khan2, Azhar Rasul3
1Central Research Laboratory, Jilin University Bethune Second Hospital, Changchun, Jilin, P.R. China.
Abstract:
Human osteosarcoma is an aggressive tumor which frequently resists chemotherapy; therefore, the search for new agents for its treatment is of great importance. Isoalantolactone, isolated from Inula spp., has been reported to inhibit the growth of several types of cancer cells. However, no prior research has been conducted to demonstrate the antiproliferative potential of isoalantolactone on osteosarcoma. The present study is the first to investigate the effects of isoalantolactone on cell viability in human osteosarcoma U2OS, MG-63 and Saos-2 cells, and its mechanism of action in U2OS cells. Our results demonstrated that isoalantolactone triggered S and mainly G2/M cell cycle phase arrest, accompanied by the downregulation of the expression of cyclin B1 at the protein and mRNA levels. Moreover, isoalantolactone induced apoptosis that was associated with reactive oxygen species (ROS) generation and the dissipation of mitochondrial membrane potential (MMP). Furthermore, our results indicated that this compound upregulated DR5, FADD and cleaved caspase-8, increased the interation between DR5 and FADD, and inhibited the expression of nuclear NF-κBp65. We also found that isoalantolactone-induced apoptosis was associated with the downregulation of Bcl-2 and upregulation of Bax, which finally led to the activation of caspase-3 and its downstream substrate, PARP, in osteosarcoma U2OS cells. Isoalantolactone-induced apoptosis was markedly abrogated when the cells were pretreated with N-acetylcysteine (NAC), a specific ROS inhibitor, suggesting that the apoptosis-inducing effect of isoalantolactone in osteosarcoma cells was mediated by reactive oxygen species. Taken together, our data demonstrated that isoalantolactone induces ROS-dependent apoptosis in U2OS cells via a novel mechanism involving inhibition of NF-κBp65 and provide the rationale for further in vivo and preclinical investigation of isoalantolactone against osteosarcoma.
Insights
Isoalantolactone effectively inhibits osteosarcoma cell growth by inducing apoptosis through reactive oxygen species (ROS) generation and cell cycle arrest. This natural compound shows promise as a novel therapeutic agent for osteosarcoma treatment.
Area of Science:
- Oncology
- Pharmacology
- Biochemistry
Background:
- Human osteosarcoma is an aggressive cancer with limited treatment options.
- Isoalantolactone, derived from Inula spp., exhibits anticancer properties against various cell types.
- Previous research has not explored isoalantolactone's effects on osteosarcoma.
Purpose of the Study:
- To investigate the antiproliferative effects of isoalantolactone on human osteosarcoma cells.
- To elucidate the mechanism of action of isoalantolactone in osteosarcoma U2OS cells.
Main Methods:
- Cell viability assays were performed on U2OS, MG-63, and Saos-2 osteosarcoma cell lines.
- Cell cycle analysis, western blotting, and quantitative real-time PCR were used to determine the mechanism of action.
- Apoptosis-related markers, including reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) dissipation, and caspase activation, were assessed.
- The role of ROS in isoalantolactone-induced apoptosis was confirmed using N-acetylcysteine (NAC).
Main Results:
- Isoalantolactone induced S and G2/M cell cycle arrest, downregulating cyclin B1 expression.
- The compound triggered apoptosis via ROS generation and MMP dissipation.
- Isoalantolactone modulated apoptosis-related proteins, including upregulation of DR5, FADD, cleaved caspase-8, Bax, and activation of caspase-3 and PARP.
- Inhibition of NF-κBp65 and downregulation of Bcl-2 were observed.
- Apoptosis induction was dependent on ROS, as evidenced by NAC treatment.
Conclusions:
- Isoalantolactone exhibits significant antiproliferative activity against human osteosarcoma cells.
- The compound induces ROS-dependent apoptosis through a novel mechanism involving cell cycle arrest and modulation of key apoptotic pathways.
- Isoalantolactone presents a potential therapeutic candidate for osteosarcoma, warranting further preclinical investigation.
Related Concept Videos
01:31The Intrinsic Apoptotic Pathway
01:17The Extrinsic Apoptotic Pathway
02:26NF-κB-dependent Signaling Pathway
NF-κB-dependent Signaling Mechanism
The...