RESUMO
Forced expression of the cytokine-induced large GTPase, human Guanylate-Binding Protein-1 (hGBP-1), in ovarian cancer cell lines increases resistance to paclitaxel. Elevated hGBP-1 RNA in ovarian tumors correlates with shorter recurrence-free survival. In contract, hGBP-1 is part of a gene signature predicting improved prognosis in all subtypes of breast cancers. hGBP-1 does not confer paclitaxel resistance on MCF-7 and TMX2-28 breast cancer cells. Expression of the isotype of the hGBP-1-interacting protein, PIM1, which may contribute to paclitaxel resistance when associated with hGBP-1, is different in breast and ovarian cancer cell lines. Breast cancer cell lines express the 44 kDa isoform of PIM-1, and ovarian cancer cell lines express the 33 kDa isoform.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Citoproteção , Proteínas de Ligação ao GTP/metabolismo , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Paclitaxel/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Citoproteção/efeitos dos fármacos , Intervalo Livre de Doença , Feminino , Humanos , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Tubulina (Proteína)/metabolismoRESUMO
Ovarian cancer is the gynecological cancer with the poorest prognosis. One significant reason is the development of resistance to the chemotherapeutic drugs used in its treatment. The large GTPase, hGBP-1, has been implicated in paclitaxel resistance in ovarian cell lines. Forced expression of hGBP-1 in SKOV3 ovarian cancer cells protects them from paclitaxel-induced cell death. However, prior to this study, nothing was known about whether hGBP-1 was expressed in ovarian tumors and whether its expression correlated with paclitaxel resistance. hGBP-1 is expressed in 17% of ovarian tumors from patients that have not yet received treatment. However, at least 80% of the ovarian tumors that recurred after therapies that included a tax-ane, either paclitaxel or docetaxel, were positive for hGBP-1. In addition, hGBP-1 expression predicts a significantly shorter progression-free survival in ovarian cancers. Based on these studies, hGBP-1 could prove to be a potential biomarker for paclitaxel resistance in ovarian cancer.