TY - JOUR
T1 - MAD2γ, a novel MAD2 isoform, reduces mitotic arrest and is associated with resistance in testicular germ cell tumors
AU - López-Saavedra, Alejandro
AU - Ramírez-Otero, Miguel
AU - Diaz-Chavez, Jose
AU - Cáceres-Gutiérrez, Rodrigo
AU - Justo-Garrido, Monserrat
AU - Andonegui, Marco A.
AU - Mendoza, Julia
AU - Downie-Ruíz, Ángela
AU - Cortés, Carlo César G.
AU - Reynoso, Nancy
AU - Castro-Hernández, Clementina
AU - Domínguez-Gómez, Guadalupe
AU - Santibáñez, Miguel
AU - Fabián-Morales, Eunice
AU - Pruefer, Franz
AU - Luna-Maldonado, Fernando
AU - González-Barrios, Rodrigo
AU - Herrera, Luis A.
N1 - Publisher Copyright:
© 2016 The Author(s). Published with license by Taylor & Francis Group, LLC.
PY - 2016/8/2
Y1 - 2016/8/2
N2 - ABSTRACT: Background: Prolonged mitotic arrest in response to anti-cancer chemotherapeutics, such as DNA-damaging agents, induces apoptosis, mitotic catastrophe, and senescence. Disruptions in mitotic checkpoints contribute resistance to DNA-damaging agents in cancer. MAD2 has been associated with checkpoint failure and chemotherapy response. In this study, a novel splice variant of MAD2, designated MAD2γ, was identified, and its association with the DNA damage response was investigated. Methods: Endogenous expression of MAD2γ and full-length MAD2 (MAD2α) was measured using RT-PCR in cancer cell lines, normal foreskin fibroblasts, and tumor samples collected from patients with testicular germ cell tumors (TGCTs). A plasmid expressing MAD2γ was transfected into HCT116 cells, and its intracellular localization and checkpoint function were evaluated according to immunofluorescence and mitotic index. Results: MAD2γ was expressed in several cancer cell lines and non-cancerous fibroblasts. Ectopically expressed MAD2γ localized to the nucleus and reduced the mitotic index, suggesting checkpoint impairment. In patients with TGCTs, the overexpression of endogenous MAD2γ, but not MAD2α, was associated with resistance to cisplatin-based chemotherapy. Likewise, cisplatin induced the overexpression of endogenous MAD2γ, but not MAD2α, in HCT116 cells. Conclusions: Overexpression of MAD2γ may play a role in checkpoint disruption and is associated with resistance to cisplatin-based chemotherapy in TGCTs.
AB - ABSTRACT: Background: Prolonged mitotic arrest in response to anti-cancer chemotherapeutics, such as DNA-damaging agents, induces apoptosis, mitotic catastrophe, and senescence. Disruptions in mitotic checkpoints contribute resistance to DNA-damaging agents in cancer. MAD2 has been associated with checkpoint failure and chemotherapy response. In this study, a novel splice variant of MAD2, designated MAD2γ, was identified, and its association with the DNA damage response was investigated. Methods: Endogenous expression of MAD2γ and full-length MAD2 (MAD2α) was measured using RT-PCR in cancer cell lines, normal foreskin fibroblasts, and tumor samples collected from patients with testicular germ cell tumors (TGCTs). A plasmid expressing MAD2γ was transfected into HCT116 cells, and its intracellular localization and checkpoint function were evaluated according to immunofluorescence and mitotic index. Results: MAD2γ was expressed in several cancer cell lines and non-cancerous fibroblasts. Ectopically expressed MAD2γ localized to the nucleus and reduced the mitotic index, suggesting checkpoint impairment. In patients with TGCTs, the overexpression of endogenous MAD2γ, but not MAD2α, was associated with resistance to cisplatin-based chemotherapy. Likewise, cisplatin induced the overexpression of endogenous MAD2γ, but not MAD2α, in HCT116 cells. Conclusions: Overexpression of MAD2γ may play a role in checkpoint disruption and is associated with resistance to cisplatin-based chemotherapy in TGCTs.
KW - DNA damage
KW - M phase cell cycle checkpoints
KW - alternative splicing
KW - cisplatin
KW - mitotic index
KW - protein isoforms
KW - testicular germ cell tumor
UR - http://www.scopus.com/inward/record.url?scp=84979021077&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84979021077&partnerID=8YFLogxK
U2 - 10.1080/15384101.2016.1198863
DO - 10.1080/15384101.2016.1198863
M3 - Article
C2 - 27315568
AN - SCOPUS:84979021077
SN - 1538-4101
VL - 15
SP - 2066
EP - 2076
JO - Cell Cycle
JF - Cell Cycle
IS - 15
ER -