A switch in RND3-RHOA signaling is critical for melanoma cell invasion following mutant-BRAF inhibition

Autor: Paul J. Higgins, R. Matthew Klein
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Proto-Oncogene Proteins B-raf
rho GTP-Binding Proteins
Cancer Research
RHOA
Indoles
Cell Survival
Short Communication
Recombinant Fusion Proteins
Mutant
Biology
lcsh:RC254-282
03 medical and health sciences
0302 clinical medicine
RNA interference
Cell Movement
Cell Line
Tumor

Spheroids
Cellular

medicine
Humans
Neoplasm Invasiveness
neoplasms
Melanoma
030304 developmental biology
0303 health sciences
Sulfonamides
Rnd3
Imidazoles
lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens
medicine.disease
3. Good health
Clinical trial
Oncology
Amino Acid Substitution
Drug Resistance
Neoplasm

030220 oncology & carcinogenesis
Gene Knockdown Techniques
Cancer research
biology.protein
Molecular Medicine
Mutant Proteins
RNA Interference
Signal transduction
rhoA GTP-Binding Protein
Signal Transduction
Zdroj: Molecular Cancer
Molecular Cancer, Vol 10, Iss 1, p 114 (2011)
ISSN: 1476-4598
Popis: Background The initial use of BRAF targeted therapeutics in clinical trials has demonstrated encouraging responses in melanoma patients, although a rise in drug-resistant cells capable of advancing malignant disease has been described. The current study uses BRAFV600E expressing WM793 melanoma cells to derive data aimed at investigating the molecular determinant of cell invasion following treatment with clinical BRAF inhibitors. Findings Small-molecule inhibitors targeting BRAF reduced MEK1/2-ERK1/2 pathway activation and cell survival; yet, viable cell subpopulations persisted. The residual cells exhibited an elongated cell shape, prominent actin stress fibers and retained the ability to invade 3-D dermal-like microenvironments. BRAF inhibitor treatments were associated with reduced expression of RND3, an antagonist of RHOA activation, and elevated RHOA-dependent signaling. Restoration of RND3 expression or RHOA knockdown attenuated the migratory ability of residual cells without affecting overall cell survival. The invasive ability of BRAF inhibitor treated cells embedded in collagen gels was diminished following RND3 re-expression or RHOA depletion. Conversely, melanoma cell movement in the absence of BRAF inhibition was unaffected by RND3 expression or RHOA depletion. Conclusion These data reveal a novel switch in the requirement for RND3 and RHOA in coordinating the movement of residual WM793 cells that are initially refractive to BRAF inhibitor therapy. These results have important clinical implications because they suggest that combining BRAF inhibitors with therapies that target the invasion of drug-resistant cells could aid in controlling disease relapse.
Databáze: OpenAIRE