Exoenzyme C3 transferase lowers actin cytoskeleton dynamics, genomic stability and survival of malignant melanoma cells under UV-light stress

Autor(es)

Magalhaes, Yuli T. ^[1] ; Cardella, Giovanna D. ^[1] ; Forti, Fabio L. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Chem, Dept Biochem, Biomol Syst Signaling Lab, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY; v. 209, AUG 2020.
• Citações Web of Science: 0

Resumo

Actin cytoskeleton remodeling is the major motor of cytoskeleton dynamics driving tumor cell adhesion, migration and invasion. The typical RhoA, RhoB and RhoC GTPases are the main regulators of actin cytoskeleton dynamics. The C3 exoenzyme transferase from Clostridium botulinum is a toxin that causes the specific ADP-ribosylation of Rho-like proteins, leading to its inactivation. Here, we examine what effects the Rho GTPase inhibition and the consequent actin cytoskeleton instability would have on the emergence of DNA damage and on the recovery of genomic stability of malignant melanoma cells, as well as on their survival. Therefore, the MeWo cell line, here assumed as a melanoma cell line model for the expression of genes involved in the regulation of the actin cytoskeleton, was transiently transfected with the C3 toxin and subsequently exposed to UV-radiation. Phalloidin staining of the stress fibers revealed that actin cytoskeleton integrity was strongly disrupted by the C3 toxin in association with reduced melanoma cells survival, and further enhanced the deleterious effects of UV light. MeWo cells with actin cytoskeleton previously perturbed by the C3 toxin still showed higher levels and accumulation of UV-damaged DNA (strand breaks and cyclobutane pyrimidine dimers, CPDs). The interplay between reduced cell survival and impaired DNA repair upon actin cytoskeleton disruption can be explained by constitutive ERK1/2 activation and an inefficient phosphorylation of DDR proteins (gamma H2AX, CHK1 and p53) caused by C3 toxin treatment. Altogether, these results support the general idea that actin network help to protect the genome of human cells from damage caused by UV light through unknown molecular mechanisms that tie the cytoskeleton to processes of genomic stability maintenance. (AU)

• Processo FAPESP: 17/01451-7 - Estudos da via de sinalização da GTPase Rho nas respostas de gliomas frente a estresse genotóxico
• Beneficiário: Yuli Thamires Magalhães
• Linha de fomento: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 19/05736-1 - Estudo da participação do citoesqueleto de actina e tubulina no reparo de danos no DNA de gliomas após tratamentos com radiação gama
• Beneficiário: Giovanna Duo Cardella
• Linha de fomento: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 15/03983-0 - Investigação molecular e funcional da interação de DUSP3 com proteínas nucleares: implicações em mecanismos de reparo de DNA
• Beneficiário: Fábio Luis Forti
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/01753-6 - Identificação e investigação funcional de proteínas que interagem com as enzimas Cdc42 e DUSP12 em células humanas sob condições de instabilidade genômica: uma abordagem proteômica
• Beneficiário: Deborah Schechtman
• Linha de fomento: Auxílio à Pesquisa - Regular