Juliana M. Sousa-Canavez

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.

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.

Genome Sequence and Assembly of Bos indicus

Cattle are divided into 2 groups referred to as taurine and indicine, both of which have been under strong artificial selection due to their importance for human nutrition. A side effect of this domestication includes a loss of genetic diversity within each specialized breed. Recently, the first taurine genome was sequenced and assembled, allowing for a better understanding of this ruminant species. However, genetic information from indicine breeds has been limited. Here, we present the first genome sequence of an indicine breed (Nellore) generated with 52X coverage by SOLiD sequencing platform. As expected, both genomes share high similarity at the nucleotide level for all autosomes and the X chromosome. Regarding the Y chromosome, the homology was considerably lower, most likely due to uncompleted assembly of the taurine Y chromosome. We were also able to cover 97% of the annotated taurine protein-coding genes.

Tgf-β1 expression as a biomarker of poor prognosis in prostate cancer

OBJECTIVE: To evaluate the correlation between transforming growth factor beta (TGF-β1) expression and prognosis in prostate cancer. PATIENTS AND METHODS: TGF-β1 expression levels were analyzed using the quantitative real-time polymerase chain reaction to amplify RNA that had been isolated from fresh-frozen malignant and benign tissue specimens collected from 89 patients who had clinically localized prostate cancer and had been treated with radical prostatectomy. The control group consisted of 11 patients with benign prostate hyperplasia. The expression levels of TGF-β1 were compared between the groups in terms of Gleason scores, pathological staging, and prostate-specific antigen serum levels. RESULTS: In the majority of the tumor samples, TGF-β1 was underexpressed 67.0% of PCa patients. The same expression pattern was identified in benign tissues of patients with prostate cancer. Although most cases exhibited underexpression of TGF-β1, a higher expression level was found in patients with Gleason scores ≥7 when compared to patients with Gleason scores <7 (p = 0.002). Among the 26 cases of TGF-β1 overexpression, 92.3% had poor prognostic features. CONCLUSIONS: TGF-β1 was underexpressed in prostate cancers; however, higher expression was observed in tumors with higher Gleason scores, which suggests that TGF-β1 expression may be a useful prognostic marker for prostate cancer. Further studies of clinical specimens are needed to clarify the role of TGF-β1 in prostate carcinogenesis.

MMP-9 overexpression due to TIMP-1 and RECK underexpression is associated with prognosis in prostate cancer

Background Extracellular 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 and its specific inhibitors, TIMP-1 and RECK, are expressed in a reproducible, specific pattern and if the profiles are related to prognosis and clinical outcome in prostate cancer (PC). Methods MMP-9, TIMP-1, and RECK expression levels were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) in fresh-frozen malignant tissue specimens collected from 79 patients with clinically localized PC submitted to radical prostatectomy (RP). Frozen benign prostatic tissue from another 10 men with prostate cancer, also submitted to RP, was analyzed to determine if the profile of gene expression was maintained. The control group consisted of 11 patients with benign prostate hyperplasia (BPH). Results In the tumor samples, MMP-9 was overexpressed by 9.2 times, and TIMP-1 and RECK were underexpressed (0.75 and 0.80 times, respectively). Overexpression of MMP-9 was significantly related to PSA levels above 10 ng/mL (p=0.033). In addition, MMP-9 overexpression was related to biochemical recurrence, with a marginal statistical significance (p=0.089). MMP-9 was also overexpressed in benign tissues of patients with PC, as were TIMP-1 and RECK, in contrast to their underexpression in tumor samples. Conclusion Our results show that MMP-9 is overexpressed and its negative regulators are underexpressed in PC tissue, emphasizing a possible role of MMP-9 in the carcinogenesis process. Additionally, we noticed a relationship between MMP-9 overexpression and increased levels of PSA, an important prognostic factor. In benign tissue adjacent to tumors, the MMP-9 equilibrium is likely maintained because the expression of its negative regulators is preserved.

FN1, GALE, MET, and QPCT overexpression in papillary thyroid carcinoma: Molecular analysis using frozen tissue and routine fine-needle aspiration biopsy samples

Thyroid nodules are a common clinical problem, and fine‐needle aspiration biopsy (FNAB) is widely used for its evaluation. Only 5% are malignant, being papillary carcinoma (PC) the most frequent neoplasia. Approximately 20% are classified as indeterminate or suspicious for malignancy. Gene‐expression pattern may be useful for diagnosing PC in difficult or ambiguous cases. In our prior study, we were able to apply RT‐PCR method in a series of routinely performed FNAB of thyroid nodules using individual, residual samples. In this study, a total of 70 thyroid samples were evaluated for the expression of MPPED2, H/HBA2, MET, FN1, GALE, and QPCT genes, including 24 cases of frozen thyroid tissue, 12 nodular hyperplasia and 12 PC, and the 46 consecutive thyroid FNAB samples, previously analyzed (3 positive, 10 indeterminate and 32 negative for malignancy, and 1 insufficient). FN1, GALE, MET, and QPCT mRNA expression were significantly different in benign and malignant samples, with similar pattern of overexpression in aspirates compared to frozen tissue. H/HBA2 and MPPED2 expression varied. Histological correlation was possible in five indeterminate cases, revealing one PC and four benign lesions. In conclusion, FN1, GALE, MET, and QPCT were significantly overexpressed in thyroid PC. RT‐PCR method could be applied to routine FNAB, showing a similar pattern of overexpression. Despite the small number of cases evaluated, our results suggest that molecular analysis may be of assistance in patients with indeterminate/suspicious cytology, adding elements for preoperative diagnosis and better management of these patients. Diagn. Cytopathol. 2011.

Matrix metalloproteinase-2 polymorphism is associated with prognosis in prostate cancer

OBJECTIVE Prostate cancer (PCa) is the most frequent tumor in males in Brazil. Single nucleotide polymorphisms (SNP) have been demonstrated in the promoter region of matrix metalloproteinases (MMPs) genes and have been associated with development and progression of some cancers. In this study, our aim was to investigate a possible relation between polymorphism of the promoter region of the MMP2 gene and classical prognostic parameters in 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 fluorescent probes (TaqMan). RESULTS In patients with tumors of a higher stage (pT3), a polymorphic allele in the MMP2 gene was more frequent (P = 0.026) than in patients with lower tumor stage. A polymorphic allele in the MMP2 gene was more frequent in Gleason ≥ 7 than in Gleason ≤ 6 (P = 0.042). CONCLUSIONS We conclude that MMP2 polymorphism can be used together with pathological stage and Gleason score to identify patients with worse prognosis. Our results illustrate the potential use of MMP2 SNP as a molecular marker for prostate cancer.

The Role of Prostate Specific Membrane Antigen and Pepsinogen C Tissue Expression as an Adjunctive Method to Prostate Cancer Diagnosis

PURPOSE The diagnosis of prostate cancer in men with persistently increased prostate specific antigen after a negative prostate biopsy has become a great challenge for urologists and pathologists. We analyzed the diagnostic value of 6 genes in the tissue of patients with prostate cancer. MATERIALS AND METHODS The study was comprised of 50 patients with localized disease who underwent radical prostatectomy. Gene selection was based on a previous microarray analysis. Among 4,147 genes with different expressions between 2 pools of patients 6 genes (PSMA, TMEFF2, GREB1, TH1L, IgH3 and PGC) were selected. These genes were tested for diagnostic value using the quantitative reverse transcription polymerase chain reaction method. Initially malignant tissue samples from 33 patients were analyzed and in the second part of the study we analyzed benign tissue samples from the other 17 patients with prostate cancer. The control group was comprised of tissue samples of patients with benign prostatic hyperplasia. RESULTS Analysis of malignant prostatic tissue demonstrated that prostate specific membrane antigen was over expressed (mean 9 times) and pepsinogen C was under expressed (mean 1.3 x 10(-4) times) in all cases compared to benign prostatic hyperplasia. The other 4 tested genes showed a variable expression pattern not allowing for differentiation between benign and malignant cases. When we tested these results in the benign prostate tissues from patients with cancer, pepsinogen C maintained the expression pattern. In terms of prostate specific membrane antigen, despite over expression in most cases (mean 12 times), 2 cases (12%) presented with under expression. CONCLUSIONS Pepsinogen C tissue expression may constitute a powerful adjunctive method to prostate biopsy in the diagnosis of prostate cancer cases.

Underexpression of MMP-2 and its regulators, TIMP2, MT1-MMP and IL-8, is associated with prostate cancer.

OBJECTIVE Extracellular matrix homeostasis is strictly maintained by a coordinated balance between the expression of metalloproteinases (MMPs) and their regulators. The purpose of this study was to investigate whether MMP-2 and its specifi c regulators, TIMP-2, MT1-MMP and IL-8, are expressed in a reproducible, specific pattern and if the profiles are related to prognosis and clinical outcome of prostate cancer (PCa). MATERIALS AND METHODS MMP-2, TIMP-2, MT1-MMP and IL-8 expression levels were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) in freshly frozen malignant and benign tissue specimens collected from 79 patients with clinically localized PCa who underwent radical prostatectomies. The control group consisted of 11 patients with benign prostate hyperplasia (BPH). The expression profile of the MMP-2 and its regulators were compared using Gleason scores, pathological stage, pre-operative PSA levels and the fi nal outcome of the PCa. RESULTS The analysis of 79 specimens of PCa revealed that MMP-2, TIMP-2, MT1-MMP and IL-8 were underexpressed at 60.0%, 72.2%, 62.0% and 65.8%, respectively, in malignant prostatic tissue in relation to BPH samples. Considering the prognostic parameters, we demonstrated that high Gleason score tumors (≥ 7) overexpressed MMP-2 (p = 0.048) and TIMP-2 (p = 0.021), compared to low Gleason score tumors (< 7). CONCLUSION We have demonstrated that MMP-2 and its regulators are underexpressed in PCa. Alternatively, overexpression of MMP-2 and TIMP-2 was related to higher Gleason score tumors. We postulate that alterations in metalloproteinase expression may be important in the control of tissue homeostasis related to prostate carcinogenesis and tumor behavior.