MicroRNAs (miRNAs) are noncoding RNAs that regulate expression of target mRNAs and are controlled by tumor suppressors and oncogenes. Altered expression of specific miRNAs in several tumor types and its association with poor prognosis parameters have been reported. Fewer data are available on its impact on patients' survival. We studied the impact of the expression of miR-17-5p, miR-106a, and miR-126 on survival and its correlation with the levels of their target mRNAs and host gene and TP53 alterations. We assessed in 110 colon cancer patients the levels of miR-17-5p, miR-106a, miR-126, E2F1, and EGFL7 by quantitative real-time RT-PCR and loss of heterozygosity (LOH) in the TP53 region. Tumor characteristics, disease-free survival (DFS), and overall survival (OS) were examined in each patient. Altered expression of miR-17-5p, miR-106a, and EGFL7 was associated with pathological tumor features of poor prognosis. Downregulation of miR-106a predicted shortened DFS (P = 0.03) and OS (P = 0.04). miR-17-5p correlated with DFS only at early stages (P = 0.07). Inverse correlations were found between miR-17-5p and miR-106a levels and their target expression, E2F1 (P = 0.04 and P = 0.03, respectively). No correlation was found between miR-126 expression and its host gene levels, EGFL7. miR-106a deregulation was revealed as a marker of DFS and OS independent of tumor stage. The lack of association between expression of miR-126 and its host gene EGFL7 suggests their regulation by independent stimuli. Inverse correlation between miR-17-5p and miR-106a and E2F1 levels supports E2F1 as a target mRNA for the two miRNAs.
e13119 Background: Male breast cancer corresponds to 1% of breast cancer diagnoses. Given this low incidence, the tumors detected have a worse prognosis and lethality. Formalin fixation and paraffin-embedding (FFPE) methods are the most common to maintain biopsied samples. It is a low-cost procedure and is a valuable resource for the study of pathological molecular mechanisms and research of potential biomarkers and therapeutic target molecules. However, in this technique cross-links are formed compromising protein extraction, resulting in low yield and quality for mass spectrometry analysis. Objective: To present an optimized method of protein extraction from male breast FFPE samples for proteomic analysis. Methods: Four protein extraction protocols were optimized and tested in female breast cancer FFPE samples from Haroldo Juaçaba Hospital/Cancer Institute of Ceará to preserve the male sample. Each protocol was performed using a total of eight 5uM tumor slides. Different deparaffinization processes were tested followed by distinct extraction buffers and variable incubation time. The characteristics of each of the protocols and optimizations are presented in the table. The quantification of the protein profile was carried out in nanodrop 2000. The protocol with the highest yield was used in the male breast cancer sample FFPE. Analysis of the protein profile in polyacrylamide gel (SDS PAGE) was performed. Results: Protocol IV presented the highest yield of protein (16.9 mg/mL) and protocols I, II, and III presented, 0.46 mg/mL and 0.28 mg/ml, and 2.3 mg/mL, respectively. Protocol IV was selected to be used in the male breast cancer sample and the yield was 14.26 mg/mL, similar to the female sample. Protein bands from male and female samples using protocol IV were detected on the SDS-PAGE gel. Conclusions: Protocol IV performed a satisfactory protein yield in breast cancer samples FFPE. [Table: see text]
Background Inflammatory Bowel Disease (IBD) with colonic involvement increases colorectal cancer risk. However, the distinction between IBD related and sporadic dysplasia in IBD patients is difficult. Some data favours the importance of abnormal DNA methylation in IBD-related carcinogenesis. Our study aimed to define methylation patterns in patients with a colonic cancer or dysplasia diagnosis following an IBD diagnosis. Methods Multicentric cross-sectional study- 91 samples from colonic mucosa with/without dysplasia from 9 patients with IBD-related dysplasia/cancer and 26 patients with IBD and sporadic dysplasia/cancer were included. Methylation patterns of CpG islands in the promoter regions of 67 genes were studied by Methylation-specific Multiplex Ligation-dependent Probe Amplification. Results Mean age at IBD diagnosis: 42±16 years; at dysplasia diagnosis: 56± ± 14 years. Twenty-nine patients had ulcerative colitis. Twenty-five patients had at least 1 lesion endoscopically described as adenoma-like, 4 at least 1 non-adenoma like, 3 had cancer and 3 had dysplasia in flat mucosa. No patient had both adenoma-like and non-adenoma-like lesions. Patients with an IBD-related lesion were significantly younger at IBD diagnosis (p = 0.003) and at dysplasia/cancer diagnosis (p = 0.039). Promoter methylation of IGF2, RARB, ESR1, CHFR, CDH13, WT1, GATA5, WIF1 genes was significantly associated to dysplasia/cancer; methylation of MSH6, TIMP3 was significantly associated to IBD-related dysplasia/cancer. Promoter methylation of MSH6, MSH3, RUNX3, CRABP1, TP73, RARB, CDH13, PAX5, WT1, THBS1, TP53, SFRP1, WIF1, APAF1, BCL2 genes was significantly associated to active IBD. Conclusion Methylation analysis, namely of MSH6, may contribute to the classification of dysplastic lesions in IBD– to be further tested in prospective studies.
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