RESUMO
The RE-1 silencing transcription factor (REST) is a repressor factor related to neuroendocrine prostate cancer (PCa) (NEPC), a poor prognostic stage mainly associated with castration-resistant PCa (CRPC). NEPC is associated with cell transdifferentiation and the epithelial-mesenchymal transition (EMT) in cells undergoing androgen deprivation therapy (ADT) and enzalutamide (ENZ). The effect of REST overexpression in the 22rv1 cell line (xenograft-derived prostate cancer) on EMT, migration, invasion, and the viability for ENZ was evaluated. EMT genes, Twist and Zeb1, and the androgen receptor (AR) were evaluated through an RT-qPCR and Western blot in nuclear and cytosolic fractions of REST-overexpressing 22rv1 cells (22rv1-REST). The migratory and invasive capacities of 22rv1-REST cells were evaluated via Transwell® assays with and without Matrigel, respectively, and their viability for enzalutamide via MTT assays. The 22rv1-REST cells showed decreased nuclear levels of Twist, Zeb1, and AR, and a decreased migration and invasion and a lower viability for ENZ compared to the control. Results were expressed as the mean + SD of three independent experiments (Mann-Whitney U test, Kruskal-Wallis, Tukey test). REST behaves like a tumor suppressor, decreasing the aggressiveness of 22rv1 cells, probably through the repression of EMT and the neuroendocrine phenotype. Furthermore, REST could represent a response marker to ENZ in PCa patients.
Assuntos
Benzamidas , Nitrilas , Feniltioidantoína , Neoplasias de Próstata Resistentes à Castração , Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/metabolismo , Antagonistas de Androgênios , Fatores de Transcrição , Linhagem Celular Tumoral , Receptores Androgênicos/metabolismo , Transição Epitelial-Mesenquimal/genética , Neoplasias de Próstata Resistentes à Castração/patologiaRESUMO
ABSTRACT Background: Decreased levels of repressor element-1 silencing transcription (REST) factor in the brain, plasma, and neuron-derived exosomes are associated with Alzheimers disease (AD). Objective: The objective of the study was to test the viability of serum REST as a possible blood-based biomarker for AD, comparing serum REST levels in AD patients from a National Institute of Health in Mexico City (with different levels of severity and comorbidities), with elderly controls (EC) and young controls (YC). Methods: We used an enzyme-linked immunosorbent assay to determine serum REST levels in AD patients (n = 28), EC (n = 19), and YC (n = 24); the AD patients were classified by dementia severity and comorbidities (depression and microangiopathy) using clinimetric tests and magnetic resonance imaging. Results: Mean serum REST levels did not differ between AD patients, EC, and YC. The severity of AD and the presence of depression or microangiopathy were not associated with serum REST levels. Conclusion: Our results differ from previously published patterns found for plasma and cerebral REST levels. Free serum REST levels may not be a viable AD blood-based biomarker. (REV INVEST CLIN. 2021;73(1):17-22)
Assuntos
Humanos , Masculino , Feminino , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Proteínas Repressoras/sangue , Doença de Alzheimer/sangue , Biomarcadores/sangue , Estudos de Casos e Controles , Fatores Etários , MéxicoRESUMO
Late-onset Alzheimer disease (LOAD) is the most frequent cause of dementia in elderly adults. However, the factors determining disease onset remain unclear. In the elderly, the activation and expression of the gene encoding RE-1 silencing transcription factor (REST) may be a determinant of neuroprotective mechanisms and good amyloidogenic pathway management. In the present study, the minimal promoter region of REST1 was genetically and epigenetically analyzed in blood samples from 21 subjects with LOAD and 20 cognitively healthy elderly subjects. Genomic DNA was isolated, treated with bisulfite and pyrosequenced, and gene expression was determined using real-time PCR. Notably, subjects with LOAD exhibited hypermethylation and significantly diminished expression of REST1 compared with healthy subjects (p = 0.001). In the LOAD group, the gene expression of CAT, SOD2 and GPX also showed a significant decrease and an increase in malondialdehyde. A docking analysis revealed that the first zinc finger protein Sp1 recognized and bound the methylated sequence in subjects with LOAD differently than the binding observed in control subjects. These results reveal that in patients with LOAD the methylation of specific sites in the promoter sequence of REST suppresses its expression and this could be regulating the decreased expression of CAT, SOD and GPX, besides interfering with the action of transcription factors as Sp1.