The efficacy and exceptionally good tolerance of estrogen blockade in the treatment of breast cancer is well recognized but novel agents are required, especially to take advantage of the multiple consecutive responses obtained in breast cancer progressing following previous hormone therapy, thus delaying the use of cytotoxic chemotherapy with its usually serious side effects. Acolbifene (ACOL) is a novel and unique antiestrogen completely free of estrogen-like activity in both the mammary gland and uterus while preventing bone loss. From the preclinical and clinical data so-far available, this new antiestrogen represents a unique opportunity for a highly potent and specific blockade of estrogen action in the mammary gland and uterus while exerting estrogen-like beneficial effects in other tissues (selective estrogen receptor modulator or SERM activity). In order to better understand the specificity of action of acolbifene, we have used Affymetrix GeneChips containing 45,000 probe sets to analyze 34,000 genes to determine the specificity of this compound compared to the pure antiestrogen fulvestrant, as well as the mixed antagonists/agonists tamoxifen and raloxifene to block the effect of estradiol (E2) and to induce effects of their own on gene expression in the mouse mammary gland. The genes modulated by E2 were those identified in two separate experiments and validated by quantitative real-time PCR (Q_RT-PCR). Three hours after the single subcutaneous injection of E2 (0.05 ug), the simultaneous administration of acolbifene, fulvestrant, tamoxifen and raloxifene blocked by 98%, 62%, 43% and 92% the number of E2-upregulated genes, respectively. On the other hand, 70%, 10%, 25% and 55% of the genes down-regulated by E2 were blocked by the same compounds. Acolbifene was also the compound which, when used alone, modulated the smallest number of genes also influenced by E2, namely 4%, thus possibly explaining the potent tumoricidal action of this compound in human breast cancer xenografts where 61% of tumors disappeared, thus bringing a new paradigm in the hormonal therapy of breast cancer.
Specific transcriptional response of four blockers of estrogen receptors on estradiol-modulated genes in the mouse mammary gland.
Specimen part, Treatment
View SamplesAim of present study was to describe the changes induced deletion of the Wfs1 gene in the temporal lobe of mice. Mutant mice were backcrossed to two different genomic backgrounds in order to exclude confounding foreign genomic background influence. Samples from temporal lobes were analyzed by using Affymetrix Genechips, expression profiles were functionally annotated by using GSEA and Ingenuity Pathway Analysis. We found that Wfs1 mutant mice are significantly smaller (20.9 1.6 g) than their wild-type counterparts (31.0 0.6g, p < 0.0001). Interestingly, genechip analysis identified growth hormone transcripts up-regulated and functional analysis found appropriate pathways activated. Moreover, we found significant increase in the level of IGF1 in the plasma of wfs1 mutant mice. Taken together, wfs1 mutation induces growth retardation whereas the growth hormone pathway is activated. Further studies are needed to describe biochemical and molecular details of the growth hormone axis in the wfs1 mutant mice.
Wfs1 gene deletion causes growth retardation in mice and interferes with the growth hormone pathway.
Specimen part
View SamplesAffymetrix Human Gene 1.1 ST Array profiling of 285 primary medulloblastoma samples.
Subgroup-specific structural variation across 1,000 medulloblastoma genomes.
Sex, Age
View Samples