Assuntos
Neoplasias Renais , Tumor de Wilms , Adulto , Humanos , Neoplasias Renais/cirurgia , Tumor de Wilms/cirurgiaRESUMO
OBJECTIVE: Long noncoding RNA (lncRNA) plays a vital role in the progression of various cancers. However, the potential mechanisms of NR2F1-AS1 in the tumorigenesis of neuroblastoma (NB) have not been determined. PATIENTS AND METHODS: The expression levels of NR2F1-AS1, miR-493 and TRIM2 were detected by RT-qPCR. The downstream target genes of NR2F1-AS1 or miR-493 were predicted by bioinformatics analysis (http://starbase.sysu.edu.cn/), which was further indicated by Luciferase reporter and RNA immunoprecipitation (RIP) assays. CCK-8, transwell, and TUNEL assays were performed to determine the viability, migration, invasion and apoptosis of NB cells. RESULTS: NR2F1-AS1 was highly expressed and miR-493 was lowly expressed in NB tissues and cell lines. The high expression of NR2F1-AS1 was associated with poor prognosis in NB. NR2F1-AS1 knockdown inhibited proliferation, migration, and invasion, and accelerated apoptosis of NB cells. MiR-493 was a downstream target of NR2F1-AS1, and the silencing of miR-493 reversed NR2F1-AS1 knockdown-attenuated progression of NB. Moreover, TRIM2 was demonstrated to be directly targeted by miR-493, and the upregulation of TRIM2 could abolish the inhibitory effect of miR-493 overexpression on the progression of NB. Finally, it was found that NR2F1-AS1 regulated TRIM2 expression by sponging miR-493. CONCLUSIONS: The present study demonstrated that NR2F1-AS1 promoted the progression of NB through the miR-493/TRIM2 axis. This finding may provide new insight into the treatment of NB.
Assuntos
MicroRNAs/metabolismo , Neuroblastoma/metabolismo , RNA Longo não Codificante/metabolismo , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Células Cultivadas , Humanos , MicroRNAs/genética , Neuroblastoma/patologia , RNA Longo não Codificante/genética , Proteínas com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
BACKGROUND: Prostate cancer is an extremely heterogeneous disease. Despite being clinically similar, some tumours are more likely to recur after surgery compared to others. Distinguishing those that need adjuvant or salvage radiotherapy will improve patient outcomes. The goal of this study was to identify circulating microRNA that could independently predict prostate cancer patient risk stratification after radical prostatectomy. METHODS: Seventy-eight prostate cancer patients were recruited at the Odette Cancer Centre in Sunnybrook Health Sciences Centre. All patients had previously undergone radical prostatectomy. Blood samples were collected simultaneously for PSA testing and miRNA analysis using NanoString nCounter technology. Of the 78 samples, 75 had acceptable miRNA quantity and quality. Patients were stratified into high- and low-risk categories based on Gleason score, pathological T stage, surgical margin status, and diagnostic PSA: patients with Gleason ≥ 8; pT3a and positive margin; pT3b and any margin; or diagnostic PSA > 20 µg/mL were classified as high-risk (n = 44) and all other patients were classified as low-risk (n = 31). RESULTS: Using our patient dataset, we identified a four-miRNA signature (miR-17, miR-20a, miR-20b, miR-106a) that can distinguish high- and low-risk patients, in addition to their pathological tumour stage. High expression of these miRNAs is associated with shorter time to biochemical recurrence in the TCGA dataset. These miRNAs confer an aggressive phenotype upon overexpression in vitro. CONCLUSIONS: This proof-of-principle report highlights the potential of circulating miRNAs to independently predict risk stratification of prostate cancer patients after radical prostatectomy.
Assuntos
Biomarcadores Tumorais/sangue , MicroRNA Circulante/sangue , Prostatectomia , Neoplasias da Próstata/sangue , Neoplasias da Próstata/cirurgia , Idoso , Linhagem Celular Tumoral , MicroRNA Circulante/genética , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/genéticaRESUMO
Androgen receptor (AR) is a transcriptional activator that, in prostate cells, stimulates gene expression required for various cellular functions, including metabolisms and proliferation. AR signaling is also essential for the development of hormone-dependent prostate cancer (PCa) and its activity can be blocked by androgen-deprivation therapies (ADTs). Although PCa patients initially respond well to ADTs, the cancer inevitably relapses and progresses to lethal castration-resistant prostate cancer (CRPC). Although AR activity is generally restored in CRPC despite the castrate level of androgens, it is unclear whether AR signaling is significantly reprogrammed. In this study, we examined the AR cistrome in a PCa cell line-derived CRPC model using integrated bioinformatical analyses. Significantly, we found that the AR cistrome is largely retained in the CRPC stage. In particular, AR-mediated lipid biosynthesis is highly conserved and reactivated during the progression to CRPC, and increased level of lipid synthesis is associated with poor prognosis. The restoration of lipid biosynthetic pathways is partially due to the increased expression of AR splice variants. Blocking lipid/cholesterol synthesis in AR variants-expressing CRPC cell line and xenograft models markedly reduces tumor growth through inhibition of mTOR pathway. Silencing the expression of a fatty acid elongase, ELOVL7, also leads to the regression of CRPC xenograft tumors. These results demonstrate the importance of reactivation of AR-regulated lipid biosynthetic pathways in driving CRPC progression, and suggest that ADTs may be therapeutically enhanced by blocking lipid biosynthetic pathways.
Assuntos
Acetiltransferases/metabolismo , Biomarcadores Tumorais/metabolismo , Lipogênese , Neoplasias de Próstata Resistentes à Castração/patologia , Receptores Androgênicos/metabolismo , Acetiltransferases/genética , Animais , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Elongases de Ácidos Graxos , Humanos , Masculino , Camundongos , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores Androgênicos/genética , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Hormone-sensitive prostate cancer typically progresses to castration resistant prostate cancer (CRPC) after the androgen deprivation therapy. We investigated the impact of microRNAs (miRs) in the transition of prostate cancer to CRPC. MiR-221/-222 was highly expressed in bone metastatic CRPC tumor specimens. We previously demonstrated that transient overexpression of miR-221/-222 in LNCaP promoted the development of the CRPC phenotype. In current study, we show that stably overexpressing miR-221 confers androgen independent (AI) cell growth in LNCaP by rescuing LNCaP cells from growth arrest at G1 phase due to the lack of androgen. Overexpressing of miR-221 in LNCaP reduced the transcription of a subgroup of androgen-responsive genes without affecting the androgen receptor (AR) or AR-androgen integrity. By performing systematic biochemical and bioinformatical analyses, we identified two miR-221 targets, HECTD2 and RAB1A, which could mediate the development of CRPC phenotype in multiple prostate cancer cell lines. Downregulation of HECTD2 significantly affected the androgen-induced and AR-mediated transcription, and downregulation of HECTD2 or RAB1A enhances AI cell growth. As a result of the elevated expression of miR-221, expression of many cell cycle genes was altered and pathways promoting epithelial to mesenchymal transition/tumor metastasis were activated. We hypothesize that a major biological consequence of upregulation of miR-221 is reprogramming of AR signaling, which in turn may mediate the transition to the CRPC phenotype.