ABSTRACT
ABSTRACT Introduction: specialists have an urge for biomarkers that can discriminate indolent prostate cancer from aggressive tumors. Ki67 is a proliferation marker, and its expression is associated with the aggressiveness of several cancers. Objective: analyze the expression of Ki67 in prostate cancer samples correlating with the aggressiveness of the disease. Methods: Ki67 mRNA levels were determined utilizing data from a TCGA cohort (Tumor(n)=492 and control(n)=52). The protein expression was determined on 94 biopsies from patients by immunohistochemical assay. Results: in mRNA, the Ki67 upregulation is associated with cancer tissue (p<0.0001) and worst disease-free survival (p=0.035). The protein upregulation is associated with increase of the ISUP score (p<0.0001), cancer stage (p=0.05), biochemical recurrence (p=0.0006) and metastasis (p<0.0001). We also show a positive correlation between Ki67 expression and ISUP score (r=0.5112, p<0.0001) and disease risk stratification (r=0.3388, p=0.0009). Ki67 expression is a factor independently associated with biochemical recurrence (p=0.002) and metastasis (p<0.0001). Finally, the patients with high Ki67expression shows better survival regarding biochemical recurrence (p=0.008) and metastasis (p=0.056). Patients with high Ki67 expression are 2.62 times more likely to develop biochemical recurrence (p=0.036). Conclusion: Ki67 upregulation is associated with prostate cancer aggressiveness.
RESUMO Introdução: especialistas precisam biomarcadores que podem discriminar o câncer de próstata indolente de tumores agressivos. Ki67 é um marcador de proliferação, e sua expressão está associada à agressividade de vários tumores. Objetivo: analisar a expressão do Ki67 em amostras de câncer de próstata correlacionando com a agressividade da doença. Métodos: os níveis de mRNA de Ki67 foram determinados utilizando dados de uma coorte de TCGA (Tumor(n)=492 e controle(n)=52). A expressão da proteína foi determinada em 94 biópsias de pacientes por ensaio imuno-histoquímica. Resultados: no mRNA, a superexpressão Ki67 está associada ao tecido canceroso (p<0,0001) e à pior sobrevida livre de doença (p=0,035). A superexpressão proteica está associada ao aumento do escore ISUP (p<0,0001), estágio de câncer (p=0,05), recorrência bioquímica (p=0,0006) e metástase (p<0,0001). Também mostramos uma correlação positiva entre a expressão Ki67 e o escore ISUP (r=0,5112, p<0,0001) e a estratificação de risco de doença (r=0,3388, p=0,0009). A expressão Ki67 é um fator independentemente associado à recorrência bioquímica (p=0,002) e metástase (p<0,0001). Finalmente, os pacientes com alta expressão de Ki67 expression mostram melhor sobrevivência em relação à recorrência bioquímica (p=0,008) e metástase (p=0,056). Os pacientes com alta expressão de Ki67 são 2,62 vezes mais propensos a desenvolver recorrência bioquímica (p=0,036). Conclusão: a superexpressão Ki67 está associada à agressividade do câncer de próstata.
ABSTRACT
Purpose To analyze a possible correlation between a miRNA expression profile and important prognostic factors for pTa urothelial carcinomas (UC), including tumor size, multiplicity and episodes of recurrence. Materials and Methods Thirty low-grade non-invasive pTa bladder UC from patients submitted to transurethral resection were studied, in a mean follow-up of 17.7 months. As controls, we used normal bladder tissue from five patients submitted to retropubic prostatectomy to treat benign prostatic hyperplasia. Extraction, cDNA and amplification were performed for 14 miRNAs (miR-100, -10a, -21, -205, -let7c, -143, -145, -221, -223, -15a, -16, -199a and -452) using specific kits, and RNU-43 and -48 were used as endogenous controls. Statistical tests were used to compare tumor size, multiplicity and episodes of recurrence with miRNAs expression profiles. Results There was a marginal correlation between multiplicity and miR-let7c over-expression. For all others miRNA no correlation between their expression and prognostic factors was found. Conclusion We did not find differences for miRNAs expression profiles associated with prognostic factors in tumor group studied. The majority of miRNAs are down-regulated, except miR-10a, over-expressed in most of cases, seeming to have increased levels in tumor with more unfavorable prognostic factors. More studies are needed in order to find a miRNA profile able to provide prognosis in pTa UC to be used in clinical practice. .
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Carcinoma/genetics , MicroRNAs/analysis , Ureteral Neoplasms/genetics , Urinary Bladder Neoplasms/genetics , Analysis of Variance , Case-Control Studies , Carcinoma/pathology , Down-Regulation , Gene Expression , Gene Expression Profiling , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/pathology , Prognosis , Reference Values , Statistics, Nonparametric , Tumor Burden/genetics , Biomarkers, Tumor/analysis , Ureteral Neoplasms/pathology , Urinary Bladder Neoplasms/pathologyABSTRACT
OBJECTIVES: Bladder cancer represents 3% of all carcinomas in the Brazilian population and ranks second in incidence among urological tumors, after prostate cancer. The loss of p53 function is the main genetic alteration related to the development of high-grade muscle-invasive disease. Prima-1 is a small molecule that restores tumor suppressor function to mutant p53 and induces cancer cell death in various cancer types. Our aim was to investigate the ability of Prima-1 to induce apoptosis after DNA damage in bladder cancer cell lines. METHOD: The therapeutic effect of Prima-1 was studied in two bladder cancer cell lines: T24, which is characterized by a p53 mutation, and RT4, which is the wild-type for the p53 gene. Morphological features of apoptosis induced by p53, including mitochondrial membrane potential changes and the expression of thirteen genes involved in apoptosis, were assessed by microscopic observation and quantitative real-time PCR (qRT-PCR). RESULTS: Prima-1 was able to reactivate p53 function in the T24 (p53 mt) bladder cancer cell line and promote apoptosis via the induction of Bax and Puma expression, activation of the caspase cascade and disruption of the mitochondrial membrane in a BAK-independent manner. CONCLUSION: Prima-1 is able to restore the transcriptional activity of p53. Experimental studies in vivo may be conducted to test this molecule as a new therapeutic agent for urothelial carcinomas of the bladder, which characteristically harbor p53 mutations.