RESUMO
Despite increasing amounts of experimental evidence depicting the involvement of non-coding RNAs in cancer, the study of BRAFV600E-regulated genes has thus far focused mainly on protein-coding ones. Here, we identify and study the microRNAs that BRAFV600E regulates through the ERK pathway.By performing small RNA sequencing on A375 melanoma cells and a vemurafenib-resistant clone that was taken as negative control, we discover miR-204 and miR-211 as the miRNAs most induced by vemurafenib. We also demonstrate that, although belonging to the same family, these two miRNAs have distinctive features. miR-204 is under the control of STAT3 and its expression is induced in amelanotic melanoma cells, where it acts as an effector of vemurafenib's anti-motility activity by targeting AP1S2. Conversely, miR-211, a known transcriptional target of MITF, is induced in melanotic melanoma cells, where it targets EDEM1 and consequently impairs the degradation of TYROSINASE (TYR) through the ER-associated degradation (ERAD) pathway. In doing so, miR-211 serves as an effector of vemurafenib's pro-pigmentation activity. We also show that such an increase in pigmentation in turn represents an adaptive response that needs to be overcome using appropriate inhibitors in order to increase the efficacy of vemurafenib.In summary, we unveil the distinct and context-dependent activities exerted by miR-204 family members in melanoma cells. Our work challenges the widely accepted "same miRNA family = same function" rule and provides a rationale for a novel treatment strategy for melanotic melanomas that is based on the combination of ERK pathway inhibitors with pigmentation inhibitors.
Assuntos
Melanoma Amelanótico/genética , Melanoma/genética , MicroRNAs/genética , Neoplasias Cutâneas/genética , Subunidades sigma do Complexo de Proteínas Adaptadoras/genética , Subunidades sigma do Complexo de Proteínas Adaptadoras/metabolismo , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Humanos , Indóis/farmacologia , Sistema de Sinalização das MAP Quinases , Melanoma/metabolismo , Melanoma/patologia , Melanoma Amelanótico/tratamento farmacológico , Melanoma Amelanótico/metabolismo , Melanoma Amelanótico/patologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Sulfonamidas/farmacologia , Transfecção , VemurafenibRESUMO
A 47-year old, Caucasian man underwent extracorporeal shock wave lithotripsy (ESWL) of a 14mm calcium stone in the right renal pelvis, without urinary tract obstruction or sepsis. 24 hours after ESWL septic shock occurred and the patient was admitted to the Intensive Care Unit (ICU). Escherichia coli emerged from the blood and urine culture. The patient developed acute renal failure and it was necessary to start a continuous renal replacement therapy (CRRT). Infection was successfully treated, patient recovered renal function and an improvement of general condition occurred. The patient was then discharged but three day later the patient returned to the hospital to seek treatment for left facial hemiparesis and hypotonia of his left arm. The brain computed tomography showed a wide abscesso (55x75mm) in the frontal right parietal region. A neurosurgical intervention was then performed and the culture of the drained material resulted positive for Escherichia coli. The guidelines of European and American Associations of Urology do not suggest a prophylactic antibiotic therapy for pre-ESWL (except in the presence of risk factors). The serious complication that occurred in the described low risk patient raises the question of whether routine culture and/or antibiotic prophylaxis, is appropriate.
