Sabrina T. Reis

Change in expression of miR-let7c, miR-100, and miR-218 from high grade localized prostate cancer to metastasis

OBJECTIVE MicroRNAs (miRNAs) are small noncoding regulatory RNAs (19-25 nucleotides) that play a major role in regulation of gene expression. They are responsible for the control of fundamental cellular processes that has been reported to be involved in human tumorigenesis. The characterization of miRNA profiles in human tumors is crucial for the understanding of carcinogenesis processes, finding of new tumor markers, and discovering of specific targets for the development of innovative therapies. The aim of this study is to find miRNAs involved in prostate cancer progression comparing the profile of miRNA expressed by localized high grade carcinoma and bone metastasis. MATERIAL AND METHODS Two groups of tumors where submitted to analyses. The first is characterized by 18 patients who underwent radical prostatectomy for treatment of localized high grade prostate carcinoma (PC) with mean Gleason score 8.6, all staged pT3. The second group is composed of 4 patients with metastatic, androgen-independent prostate carcinoma, and 2 PC cell lines. LNCaP derived from a metastatic PC to a lymph node, and another derived from an obstructive, androgen-independent PC (PcBRA1). Expression analysis of 14 miRNAs was carried out using quantitative RT-PCR. RESULTS miR-let7c, miR-100, and miR-218 were significantly overexpressed by all localized high GS, pT3 PC in comparison with metastatic carcinoma. (35.065 vs. 0.996 P<0.001), (55.550 vs. 8.314, P=0.010), and (33.549 vs. 2.748, P=0.001), respectively. CONCLUSION We hypothesize that miR-let7c, miR-100, and miR-218 may be involved in the process of metastasization of PC, and their role as controllers of the expression of RAS, c-myc, Laminin 5 β3, THAP2, SMARCA5, and BAZ2A should be matter of additional studies.

MicroRNA expression profiles in the progression of prostate cancer—from high-grade prostate intraepithelial neoplasia to metastasis⁎

INTRODUCTION Models of the multistep process related to cancer progression have been designed for many cancers including prostate. The aim of this study is to propose a new model including a possible role for recently described micro RNAs in prostate cancer (CaP) progression. METHODS Sixty-three patients underwent radical prostatectomy to treat localized prostate carcinoma. The specimens of 15 patients were representative of high grade prostate intraepithelial neoplasia (HGPIN). Fourteen specimens represented localized favorable CaP, and 34 unfavorable, mostly non-organ-confined disease. Representing the advanced disease we studied 4 metastatic androgen-independent CaP and 2 cell lines. Micro RNAs were isolated using the mirVana miRNA Isolation kit and cDNA was obtained using the TaqMan miRNA Reverse Transcription kit to the miRNAs: hsa-miR-let7c, hsa-miR-15a, hsa-miR-16, hsa-miR-21, hsa-miR-25, hsa-miR-32, hsa-miR-100, hsa-miR-143, hsa-miR-145, hsa-miR-146a, hsa-miR-191, hsa-miR-199a, hsa-miR-206, and hsa-miR-218. Quantitative RT-PCR was carried out using the ABI 7500 Fast Real-Time PCR System and the TaqMan Universal PCR Master Mix. miRNA expression levels were measured by relative quantification, and fold expression changes were determined by the 2(-ΔΔCT) method. The small nucleolar RNA RNU43 was used as an endogenous control. RESULTS Except for miR-21 and miR-206, the expression levels of all miRNAs significantly changed during the progression of CaP. Interestingly, there was a significant global loss of miRNA expression between HGPIN and metastasis at 2 important steps. The first was related to the transition from HGPIN to invasive adenocarcinoma, and the second was related to the transition from localized to metastatic adenocarcinomas. CONCLUSION Through the analysis of 14 miRNAs in 4 groups of prostate lesions, which reproduced the progression of CaP, we showed that there is a global loss of miRNA expression at 2 distinct steps. The first related to the transition between HGPIN and localized invasive carcinoma, and the second associated with the transition from localized to metastatic CaP. The importance of our study is in the identification of possible miRNAs and miRNA-targeted genes involved in the progression of prostate carcinogenesis that may help the development of potential diagnostic or prognostic markers as well as the design of new target therapies.

miR-21 may acts as an oncomir by targeting RECK, a matrix metalloproteinase regulator, in prostate cancer

BackgroundPrognosis of prostate cancer (PCa) is based mainly in histological aspects together with PSA serum levels that not always reflect the real aggressive potential of the neoplasia. The micro RNA (miRNA) mir-21 has been shown to regulate invasiveness in cancer through translational repression of the Metaloproteinase (MMP) inhibitor RECK. Our aim is to investigate the levels of expression of RECK and miR-21 in PCa comparing with classical prognostic factors and disease outcome and also test if RECK is a target of miR-21 in in vitro study using PCa cell line.Materials and methodsTo determine if RECK is a target of miR-21 in prostate cancer we performed an in vitro assay with PCa cell line DU-145 transfected with pre-miR-21 and anti-miR-21. To determine miR-21 and RECK expression levels in PCa samples we performed quantitative real-time polymerase chain reaction (qRT-PCR).ResultsThe in vitro assays showed a decrease in expression levels of RECK after transfection with pre-miR-21, and an increase of MMP9 that is regulated by RECK compared to PCa cells treated with anti-miR-21. We defined three profiles to compare the prognostic factors. The first was characterized by miR-21 and RECK underexpression (N = 25) the second was characterized by miR-21 overexpression and RECK underexpression (N = 12), and the third was characterized by miR-21 underexpression and RECK overexpression (N = 16). From men who presented the second profile (miR-21 overexpression and RECK underexpression) 91.7% were staged pT3. For the other two groups 48.0%, and 46.7% of patients were staged pT3 (p = 0.025).ConclusionsOur results demonstrate RECK as a target of miR-21. We believe that miR-21 may be important in PCa progression through its regulation of RECK, a known regulator of tumor cell invasion.

MicroRNA-100 Expression is Independently Related to Biochemical Recurrence of Prostate Cancer

PURPOSE Abnormal miRNA expression has emerged as crucial factors in carcinogenesis and is important in the comprehension of prostate cancer behavior. We determined the correlation of miRNA expression profiles with prostate cancer progression. MATERIALS AND METHODS We studied frozen specimens from 49 patients treated for prostate cancer with radical prostatectomy. We intentionally chose 28 men without and 21 with biochemical recurrence, defined as prostate specific antigen greater than 0.2 ng/ml. The expression of 14 miRNAs was determined by quantitative reverse transcriptase-polymerase chain reaction. All radical prostatectomy specimens were studied in toto to determine tumor volume, Gleason score and 2002 TNM pathological stage. Benign prostate tissue from benign prostatic hyperplasia served as a control. RESULTS Four miRNAs were related to tumor recurrence. Using the Cox regression test the risk of recurrence was 3.0, 3.3, 2.7 and 3.4 for high levels of miR-100, miR-145, miR-191 and miR-let7c, respectively. When considering statistically significant clinical variables on univariate analysis of biochemical-free survival, prostate specific antigen and tumor volume, results revealed that miR-100 and tumor volume were independently related to tumor recurrence. CONCLUSIONS A high level of miR-100 is related to biochemical recurrence of localized prostate cancer in patients treated with radical prostatectomy. The role of miR-100 during carcinogenesis must be resolved in future studies to better understand the molecular pathways in which miR-100 is involved. This may open the possibility of using it as a prognostic marker and inspire the development of a target drug.

Increased expression of MMP-9 and IL-8 are correlated with poor prognosis of Bladder Cancer

BackgroundExtracellular matrix homeostasis is strictly maintained by a coordinated balance between the expression of metalloproteinases (MMPs) and their inhibitors. The purpose of this study was to investigate whether the expression of MMP-9, MMP-2 and its specific inhibitors, are expressed in a reproducible, specific pattern and if the profiles are related to prognosis in Bladder Cancer (BC).MethodsMMP-9, MMP-2 and its specific inhibitors expression levels were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) in fresh-frozen malignant tissue collected from 40 patients with BC submitted to transurethral resection of bladder. The control group consisted of normal bladder tissue from five patients who had undergone retropubic prostatectomy to treat benign prostatic hyperplasia.ResultsMMP-9 was overexpressed in 59.0 % of patients, and MMP-2, TIMP-1, TIMP-2, MMP-14, RECK and IL-8 was underexpressed in most of the patients. Regarding prognostic parameters we observed that high-grade tumors exhibited significantly higher levels of MMP-9 and IL-8 (p = 0.012, p = 0.003). Invasive tumors (pT1-pT2) had higher expression levels of MMP-9 than superficial tumors (pTa) (p = 0.026). The same was noted for IL-8 that was more expressed by invasive tumors (p = 0.015, p = 0.048). Most importantly tumor recurrence was related with higher levels of both MMP-9 (p = 0.003) and IL-8 (p = 0.005).ConclusionWe have demonstrated that the overexpression of MMP-9 and higher expression of IL-8 are related to unfavorable prognostic factors of urothelial bladder cancer and tumor recurrence and may be useful in the follow up of the patients.

miRNA analysis of prostate cancer by quantitative real time PCR: Comparison between formalin-fixed paraffin embedded and fresh-frozen tissue

OBJECTIVE Micro RNA (miRNA) is a class of small noncoding RNA that plays a major role in the regulation of gene expression, which has been related to cancer behavior. The possibility of analyzing miRNA from the archives of pathology laboratories is exciting, as it allows for large retrospective studies. Formalin is the most common fixative used in the surgical pathology routine, and its promotion of nucleic acid degradation is well known. Our aim is to compare miRNA profiles from formalin-fixed paraffin embedded (FFPE) tissues with fresh-frozen prostate cancer tissues. METHODS The expression of 14 miRNAs was determined by quantitative real time polymerase chain reaction (qRT-PCR) in 5 paired fresh-frozen and FFPE tissues, which were representative of prostate carcinoma. RESULTS There was a very good correlation of the miRNA expression of miR-let7c and miR-32 between the fresh-frozen and FFPE tissues, with Pearsons correlation coefficients of 0.927 (P = 0.023) and 0.960 (P = 0.010), respectively. For the remaining miRNAs, the correlation was good with Spearman correlation coefficient of 0.638 (P < 0.001). CONCLUSION Analysis of miRNAs from routinely processed and stored FFPE prostate tissue is feasible for some miRNAs using qRT-PCR. Further studies should be conducted to confirm the reliability of using stock tissues for miRNA expression determination.

Genetic polymorphisms of matrix metalloproteinases: susceptibility and prognostic implications for prostate cancer.

PURPOSE Prostate cancer is the most common tumor in males in Brazil. Single nucleotide polymorphisms have been demonstrated to exist in the promoter regions of matrix metalloproteinase genes and they are associated with the development and progression of some cancers. We investigated the correlation between MMP1, 2, 7 and 9 polymorphisms with susceptibility to prostate cancer, and classic prognostic parameters of prostate cancer. MATERIALS AND METHODS Genomic DNA was extracted using conventional protocols. The DNA sequence containing the polymorphic site was amplified by real-time polymerase chain reaction using TaqMan(R) fluorescent probes. RESULTS For the MMP1 gene the polymorphic allele was more common in the control group than in the prostate cancer group (p <0.001). For the MMP9 gene the incidence of the polymorphic homozygote genotype was higher in the prostate cancer group (p <0.001). For higher stage tumors (pT3) a polymorphic allele in the MMP2 gene was more common (p = 0.026). When considering Gleason score, the polymorphic homozygote genotype of MMP9 was more common in Gleason 6 or less tumors (p = 0.003), while a polymorphic allele in the MMP2 gene was more common in Gleason 7 or greater tumors (p = 0.042). CONCLUSIONS MMP1 and MMP2 may protect against prostate cancer development and MMP9 may be related to higher risk. In contrast, MMP9 polymorphism was associated with a lower Gleason score and MMP2 polymorphism was associated with nonorgan confined disease.

Stage, Grade and Behavior of Bladder Urothelial Carcinoma Defined by the MicroRNA Expression Profile

PURPOSE We identified miRNA expression profiles in urothelial carcinoma that are associated with grade, stage, and recurrence-free and disease specific survival. MATERIALS AND METHODS The expression of 14 miRNAs was evaluated by quantitative reverse transcriptase-polymerase chain reaction in surgical specimens from 30 patients with low grade, noninvasive (pTa) and 30 with high grade, invasive (pT2-3) urothelial carcinoma. Controls were normal bladder tissue from 5 patients who underwent surgical treatment for benign prostatic hyperplasia. Endogenous controls were RNU-43 and RNU-48. miRNA profiles were compared and Kaplan-Meier curves were constructed to analyze disease-free and disease specific survival. RESULTS miR-100 was under expressed in 100% of low grade pTa specimens (p <0.001) and miR-10a was over expressed in 73.3% (p <0.001). miR-21 and miR-205 were over expressed in high grade pT2-3 disease (p = 0.02 and <0.001, respectively). The other miRNAs were present at levels similar to those of normal bladder tissue or under expressed in each tumor group. miR-21 over expression (greater than 1.08) was related to shorter disease-free survival in patients with low grade pTa urothelial carcinoma. Higher miR-10a levels (greater than 2.30) were associated with shorter disease-free and disease specific survival in patients with high grade pT2-3 urothelial carcinoma. CONCLUSIONS Four miRNAs were differentially expressed in the 2 urothelial carcinoma groups. miR-100 and miR-10a showed under expression and over expression, respectively, in low grade pTa tumors. miR-21 and miR-205 were over expressed in pT2-3 disease. In addition, miR-10a and miR-21 over expression was associated with shorter disease-free and disease specific survival. miRNAs could be incorporated into the urothelial carcinoma molecular pathway. These miRNAs could also serve as new diagnostic or prognostic markers and new target drugs.

Association between integrin expression and prognosis in localized prostate cancer

Integrins and other adhesion molecules are essential for maintaining the epithelial phenotype. Some studies have reported correlations between abnormalities in their expression and carcinogenesis, but their role in prostate cancer is unclear. Our aim was to study the expression profile of integrins in surgical specimens of prostate cancer and associate their expression patterns with patient outcomes.

Does Training Laparoscopic Skills in a Virtual Reality Simulator Improve Surgical Performance

BACKGROUND AND PURPOSE Several different methods of teaching laparoscopic skills have been advocated, with virtual reality surgical simulation (VRSS) being the most popular. Its effectiveness in improving surgical performance is not a consensus yet, however. The purpose of this study was to determine whether practicing surgical skills in a virtual reality simulator results in improved surgical performance. MATERIALS AND METHODS Fifteen medical students recruited for the study were divided into three groups. Group I (control) did not receive any VRSS training. For 10 weeks, group II trained basic laparoscopic skills (camera handling, cutting skill, peg transfer skill, and clipping skill) in a VRSS laparoscopic skills simulator. Group III practiced the same skills and, in addition, performed a simulated cholecystectomy. All students then performed a cholecystectomy in a swine model. Their performance was reviewed by two experienced surgeons. The following parameters were evaluated: Gallbladder pedicle dissection time, clipping time, time for cutting the pedicle, gallbladder removal time, total procedure time, and blood loss. RESULTS With practice, there was improvement in most of the evaluated parameters by each of the individuals. There were no statistical differences in any of evaluated parameters between those who did and did not undergo VRSS training, however. CONCLUSION VRSS training is assumed to be an effective tool for learning and practicing laparoscopic skills. In this study, we could not demonstrate that VRSS training resulted in improved surgical performance. It may be useful, however, in familiarizing surgeons with laparoscopic surgery. More effective methods of teaching laparoscopic skills should be evaluated to help in improving surgical performance.