Related Experiment Video
Updated: Nov 12, 2025
Intratibial Osteosarcoma Cell Injection to Generate Orthotopic Osteosarcoma and Lung Metastasis Mouse Models
Published on: October 28, 2021
Expression of canonical transient receptor potential channels in U-2 OS and MNNG-HOS osteosarcoma cell lines
Florian Lässig1, Anja Klann2, Sander Bekeschus3
1Institute of Medical Biochemistry and Molecular Biology, University Medicine Greifswald, D-17475 Greifswald, Germany.
Abstract:
In U-2 OS and MNNG-HOS osteosarcoma cells, small interfering RNA-mediated knockdown of the angiotensin-(1-7) receptor, Mas, increases cell proliferation. Whether alterations in canonical transient receptor potential channels (TRPC) expression contribute to this effect is not clear. In the present study, a basic description of TRPC subtype expression in osteosarcoma cell lines was provided. The pharmacological modulators of the angiotensin-(1-7) receptor, Mas, AVE0991 (agonist), or D-Ala7-Ang-(1-7) (antagonist) were applied to elucidate a possible role of Mas in the regulation of TRPC mRNA levels. The contribution of other G-protein coupled receptors (GPCR) or receptor tyrosine kinases to TRCP expression was studied by applying the selective pharmacological blockers of either PI3 kinase or MEK/Erk1/2 signaling, Ly294002 and PD98059. AVE0991 and D-Ala7-Ang-(1-7) exhibited no or marginal effects on TRPC mRNA expression. Ly294002 provoked a 9.6- and 5.9-fold increase in the amounts of TRPC5 mRNA in MNNG-HOS and U-2 OS cells, respectively. Additionally, Ly294002 increased TRPC6 mRNA levels; however, it had no effect on TRPCs 1, 3 and 4. Administration of PD98059 increased the amounts of TRPC6 and TRPC4 ~2-fold. In conclusion, the present study demonstrated that Mas-dependent alterations in osteosarcoma cell line proliferation were not mediated by any changes in TRPC subtype gene expression. The data shows in principle, and consistent with the literature, that the signaling pathways examined can regulate the expression of TRPCs at the mRNA level. Therefore, direct and signaling pathway-specific pharmacological targeting of TRPC subtypes may represent an option for improving the treatment of osteosarcoma.
Insights
Mas receptor knockdown in osteosarcoma cells increases proliferation, but not via TRPC channels. Signaling pathways PI3K and MEK/Erk regulate TRPC expression at the mRNA level, suggesting potential therapeutic targets.
Area of Science:
- Molecular Biology
- Oncology
- Pharmacology
Background:
- Knockdown of the angiotensin-(1-7) receptor, Mas, in osteosarcoma cells enhances proliferation.
- The role of canonical transient receptor potential (TRPC) channels in this process is unknown.
- Osteosarcoma is a primary bone cancer with significant unmet therapeutic needs.
Purpose of the Study:
- To investigate whether Mas receptor-mediated effects on osteosarcoma cell proliferation involve alterations in TRPC subtype expression.
- To explore the role of Mas receptor signaling and associated pathways (PI3K, MEK/Erk) in regulating TRPC mRNA levels in osteosarcoma cells.
Main Methods:
- Osteosarcoma cell lines (U-2 OS, MNNG-HOS) were treated with Mas receptor modulators (AVE0991, D-Ala7-Ang-(1-7)).
- The impact of PI3K (Ly294002) and MEK/Erk1/2 (PD98059) inhibitors on TRPC mRNA expression was assessed.
- Quantitative analysis of TRPC subtype mRNA levels was performed using RT-qPCR.
Main Results:
- Mas receptor modulators had no significant effect on TRPC mRNA expression.
- PI3K inhibition significantly increased TRPC5 and TRPC6 mRNA levels in both cell lines.
- MEK/Erk1/2 inhibition increased TRPC6 and TRPC4 mRNA levels.
Conclusions:
- Mas receptor-dependent regulation of osteosarcoma cell proliferation is not mediated by changes in TRPC subtype gene expression.
- Signaling pathways, including PI3K and MEK/Erk, can modulate TRPC expression at the mRNA level in osteosarcoma cells.
- Targeting TRPC subtypes via specific signaling pathways may offer a novel therapeutic strategy for osteosarcoma.
