Expression of tumor suppressors miR-195 and let-7a as potential biomarkers of invasive breast cancer

OBJECTIVE: MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the posttranscriptional level. Some miRNAs, including let-7a and miR-195, have been described as tumor suppressors. However, the roles of these microRNAs in breast cancer progression remain controversial. The aim of this study is to evaluate miR-195 and let-7a expression as potential biomarkers of invasive breast cancer. METHODS: In the present study, 200 individuals were separated into three groups: (i) 72 women constituting the control group who were selected according to rigorous and well-established criteria; (ii) 56 patients with benign breast tumors; and (iii) 72 patients with malignant breast cancers of different clinical stages. The miR-195 and let-7a expression levels in serum were evaluated by real-time PCR. The results were assessed alone and in combination, and the analysis included an estimation of sensitivity and specificity in ROC curves. RESULTS: Compared with the benign and control groups, both microRNAs were downregulated in the malignant breast cancer patient group. Compared with the malignant group, the combination of both biomarkers in the control and benign groups showed good sensitivity and specificity in the serum with AUCs of 0.75 and 0.72, respectively. The biomarker combination for the control group versus the malignant group exhibited a better sensitivity and specificity than for the benign group versus the malignant group. CONCLUSION: These findings support the evidence that the analysis of miR-195 and let-7a can be used as a non-invasive biomarker for breast cancer detection.

Odontoameloblastoma: Report of two cases.

Odontoameloblastoma (OA) is a very rare mixed odontogenic neoplasm, characterized by the simultaneous occurrence of an ameloblastoma and a compound or complex odontoma in the same tumor mass. To date, less than 50 cases of OA and/or ameloblastic odontoma have been reported in the English dental literature. This neoplasm was called ameloblastic odontoma. The term OA was included in the 1971 WHO classification. In this study, we present two cases of OA, which we hope will contribute to the awareness and knowledge of surgeons regarding the existence of this odontogenic tumor so that patients having it may be treated and followed-up properly.

The influence of water temperature during toothbrushing on root dentine: An in vitro study.

Background/Aims: The use of cold water during toothbrushing can cause dentine sensitivity and, to avoid this painful stimulus, some patients used to rinse their mouths with warm water when brushing. Thus, the objective of this study was to determine the effect of water temperature on the dental root surface during toothbrushing. Materials and Methods : Fragments of bovine dental roots were submitted to 15,000 strokes in a toothbrushing machine using a slurry of toothpaste/water, medium brushes, and a 200-g load. They were randomly divided into two groups: toothbrushing with cold water or with hot water. Tooth wear was measured by loss of weight and by tissue height. Statistical Analysis: The weight and height data obtained in 17 and 10 replicas respectively are presented as mean ± standard error of mean. The data were compared using the Kolgomorov-Smirnof (Lilliefors) test followed by one-way ANOVA. The level of significance was 5% (P < 0.05). Results: There were no significant differences between the two experimental groups. The mean percentages of weight losses were 5.61 ± 1.66 for cold water and 6.25 ± 1.98 for hot water. The mean dentine height losses were 51.02 ± 15.92 µm for cold water and 63.54 ± 17.75 µm for hot water. Conclusion: The use of warm water during toothbrushing promoted root dentine wear similar to that produced by the use of cold water. The results suggest that warm or cold water may be used during toothbrushing without any additional damage to the patients' dental hard tissues.