Annalisa Tancredi

The combined immunodetection of AP-2α and YY1 transcription factors is associated with ERBB2 gene overexpression in primary breast tumors

IntroductionOverexpression of the ERBB2 oncogene is observed in about 20% of human breast tumors and is the consequence of increased transcription rates frequently associated with gene amplification. Several studies have shown a link between activator protein 2 (AP-2) transcription factors and ERBB2 gene expression in breast cancer cell lines. Moreover, the Yin Yang 1 (YY1) transcription factor has been shown to stimulate AP-2 transcriptional activity on the ERBB2 promoter in vitro. In this report, we examined the relationships between ERBB2, AP-2α, and YY1 both in breast cancer tissue specimens and in a mammary cancer cell line.MethodsERBB2, AP-2α, and YY1 protein levels were analyzed by immunohistochemistry in a panel of 55 primary breast tumors. ERBB2 gene amplification status was determined by fluorescent in situ hybridization. Correlations were evaluated by a χ2 test at a p value of less than 0.05. The functional role of AP-2α and YY1 on ERBB2 gene expression was analyzed by small interfering RNA (siRNA) transfection in the BT-474 mammary cancer cell line followed by real-time reverse transcription-polymerase chain reaction and Western blotting.ResultsWe observed a statistically significant correlation between ERBB2 and AP-2α levels in the tumors (p < 0.01). Moreover, associations were found between ERBB2 protein level and the combined high expression of AP-2α and YY1 (p < 0.02) as well as between the expression of AP-2α and YY1 (p < 0.001). Furthermore, the levels of both AP-2α and YY1 proteins were inversely correlated to ERBB2 gene amplification status in the tumors (p < 0.01). Transfection of siRNAs targeting AP-2α and AP-2γ mRNAs in the BT-474 breast cancer cell line repressed the expression of the endogenous ERBB2 gene at both the mRNA and protein levels. Moreover, the additional transfection of an siRNA directed against the YY1 transcript further reduced the ERBB2 protein level, suggesting that AP-2 and YY1 transcription factors cooperate to stimulate the transcription of the ERBB2 gene.ConclusionThis study highlights the role of both AP-2α and YY1 transcription factors in ERBB2 oncogene overexpression in breast tumors. Our results also suggest that high ERBB2 expression may result either from gene amplification or from increased transcription factor levels.

Comprehensive Therapy in Osteoporosis Using a Single Drug: From ADFR to Strontium Ranelate

In vitro, strontium ranelate increases collagen and non-collagenic proteins synthesis by mature osteoblast enriched cells. The effects of strontium ranelate on bone formation were confirmed as the drug enhanced preosteoblastic cell replication. In the isolated rat osteoclast, a preincubation of bone slices with strontium ranelate induced a dose-dependent inhibition of the bone resorbing activity of treated rat osteoclast. Strontium ranelate dose-dependently inhibited preosteoclast differentiation. In a phase II dose ranging trial Strontium ranelate (500 mg, 1000 mg, 2000 mg/day) or placebo were given to 353 postmenopausal women with prevalent vertebral osteoporosis. At the conclusion of this 2-year study, the annual increase in lumbar BMD of the group receiving 2000 mg of strontium ranelate was + 7.3%, a significant increase in bone alkaline phosphatase, over a 6-month period and a significant decrease in N-telopeptide crosslinks throughout the 2-year period were seen. During the second year of treatment, the dose of 2000 mg was associated with a 44% reduction in the number of patients experiencing a new vertebral deformity. The primary analysis of the SOTI study, evaluating the effect of strontium ranelate 2000 mg on vertebral fracture rates, revealed a 41% reduction in the relative risk of patient experiencing a first new vertebral fracture with strontium ranelate throughout the 3-year study. The TROPOS study showed a significant reduction in the risk of experiencing a first non-vertebral fracture by 16% in the group treated with strontium ranelate throughout the 3-year study. A reduction in the risk of experiencing a hip fracture by 36% was also demonstrated in the patients at high risk of hip fracture (age > or =74 years and Femoral Neck T score < or = -2.4 according to NHANES normative value). All these results suggest that strontium ranelate is a new, effective and safe treatment of vertebral and non-vertebral osteoporosis, with a unique mode of action.

Analysis of the discriminant ability of shorter versions of the French ADAM questionnaire

Objective. To investigate whether shorter versions of the ADAM test, a screening questionnaire for andropause, provide better diagnostic value than the original tool. Methods. Five thousand and twenty-eight volunteer men aged 50–70 years attending a screening campaign for andropause, provided a fasting blood sample and completed the French ADAM test. Logistic regression analysis identified items that best predict andropause defined as serum free testosterone level below 70 ng/l. ROC curves assessed the diagnostic value of modified versions of the ADAM test, obtained by elimination of the less relevant predictors of andropause. Results. Only four items of the ADAM questionnaire may account for the diagnosis of andropause. These items concerned loss of height, decrease in libido and in enjoyment of life and deterioration in work performance. Item 9 was borderline significant. The area under the ROC curve for the short versions varied slightly from 0.555 to 0.560. As expected, model 6 has a greater specificity (56.02%) than the original tool while the efficiency increased slightly (54.85%). Conclusion. The modified versions of the ADAM test do not provide better diagnostic value than the original tool.