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Updated: May 2, 2026
A Melanoma Patient-Derived Xenograft Model
Published on: May 20, 2019
Modeling tandem AAG8-MEK inhibition in melanoma cells
Bing Sun1, Masahiro Kawahara, Teruyuki Nagamune
1Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Tokyo, Japan.
Abstract:
Drug resistance presents a challenge to the treatment of cancer patients, especially for melanomas, most of which are caused by the hyperactivation of MAPK signaling pathway. Innate or acquired drug-resistant relapse calls for the investigation of the resistant mechanisms and new anti-cancer drugs to provide implications for the ultimate goal of curative therapy. Aging-associated gene 8 (AAG8, encoded by the SIGMAR1 gene) is a chaperone protein profoundly elaborated in neurology. However, roles of AAG8 in carcinogenesis remain unclear. Herein, we discover AAG8 antagonists as new MEK inhibitors in melanoma cells and propose a novel drug combination strategy for melanoma therapy by presenting the experimental evidences. We report that specific antagonism of AAG8, efficiently suppresses melanoma cell growth and migration through, at least in part, the inactivation of the RAS-CRAF-MEK signaling pathway. We further demonstrate that melanoma cells that are resistant to AAG8 antagonist harbor refractory CRAF-MEK activity. MEK acts as a central mediator for anti-cancer effects and also for the resistance mechanism, leading to our proposal of tandem AAG8-MEK inhibition in melanoma cells. Combination of AAG8 antagonist and very low concentration of a MEK inhibitor synergistically restricts the growth of drug-resistant cells. These data collectively pinpoint AAG8 as a potential target and delineate a promising drug combination strategy for melanoma therapy.
Insights
New research identifies Aging-associated gene 8 (AAG8) antagonists as potential MEK inhibitors for melanoma. Combining AAG8 antagonism with MEK inhibition offers a promising strategy to overcome drug resistance in melanoma treatment.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Drug resistance in melanoma, often driven by MAPK pathway hyperactivation, necessitates novel therapeutic strategies.
- Aging-associated gene 8 (AAG8), a neurological chaperone, has unclear roles in cancer.
- Understanding resistance mechanisms is crucial for developing effective melanoma treatments.
Purpose of the Study:
- To investigate the role of AAG8 in melanoma and identify AAG8 antagonists as potential MEK inhibitors.
- To propose and validate a novel drug combination strategy for melanoma therapy, focusing on overcoming drug resistance.
Main Methods:
- Screening for AAG8 antagonists with MEK inhibitory activity in melanoma cells.
- Evaluating the effects of AAG8 antagonism on melanoma cell growth and migration.
- Investigating the underlying mechanisms involving the RAS-CRAF-MEK signaling pathway.
- Assessing the efficacy of combination therapy with AAG8 antagonists and MEK inhibitors in drug-resistant melanoma cells.
Main Results:
- Specific AAG8 antagonism suppressed melanoma cell growth and migration, partly via RAS-CRAF-MEK pathway inactivation.
- Melanoma cells resistant to AAG8 antagonists exhibited refractory CRAF-MEK activity.
- MEK was identified as a central mediator of both anti-cancer effects and resistance mechanisms.
- Combination of an AAG8 antagonist and a low-dose MEK inhibitor synergistically inhibited the growth of drug-resistant melanoma cells.
Conclusions:
- AAG8 is a potential therapeutic target in melanoma.
- Tandem AAG8 and MEK inhibition presents a promising combination strategy for melanoma therapy, particularly for overcoming drug resistance.
