Project description:Osteoporosis is a multifactorial disease with genetic and strong epigenetic component. In spite of enormous candidate gene association studies, the etiology and molecular mechanism of disease is not fully known. This study is undertaken to identify new markers of osteoporosis which could be vital in diagnosis and prognosis of disease, genome-wide microarray expression approach was employed on post menopausal Indian females living in same geographical area with almost similar life-style. To validate microarray gene expression pattern, qRT-PCR was performed on top 5 genes on osteoporotic (n =32) and non-osteoporotic (n=15) post menopausal females
Project description:Comparison of circulating monocytes from pre- and postmenopausal females with low or high bone mineral density (BMD). Circulating monocytes are progenitors of osteoclasts, and produce factors important to bone metabolism. Results provide insight into the role of monocytes in osteoporosis. We identify osteoporosis genes by microarray analyses of monocytes in high vs. low hip BMD (bone mineral density) subjects. Microarray analyses of monocytes were performed using Affymetrix 1.0 ST arrays in 73 Caucasian females (age: 47-56) with extremely high (mean ZBMD =1.38, n=42, 16 pre- and 26 postmenopausal subjects) or low hip BMD (mean ZBMD=-1.05, n=31, 15 pre- and 16 postmenopausal subjects). Differential gene expression analysis in high vs. low BMD subjects was conducted in the total cohort as well as pre- and post-menopausal subjects.
Project description:Gene expression profiling was carried out on peripheral blood mononuclear cells from 45 adult females. The primary research question is whether leukocyte gene expression differs in individuals with varying levels of estrogen signaling. Experiment Overall Design: Study includes adult females, 11 of whom were pre-menopausal, 12 of whom were post-menopausal, 10 of whom were post-menopausal and receiving aromatase inhibitors, and 12 of whom were receiving tamoxifen.
Project description:Background: Breast cancer patients present lower 1,25(OH)2D3 or 25(OH)D3 serum levels than unaffected women. Although 1,25(OH)2D3 pharmacological concentrations of 1,25(OH)2D3 may exert antiproliferative effects in breast cancer cell lines, much uncertainty remains about the effects of calcitriol supplementation in tumor specimens in vivo. We have evaluated tumor dimension (ultrassonography), proliferative index (Ki67 expression), 25(OH)D3 serum concentration and gene expression profile, before and after a short term calcitriol supplementation (dose to prevent osteoporosis) to post-menopausal patients. Results: Thirty three patients with operable disease had tumor samples evaluated. Most of them (87.5%) presented 25(OH)D3 insufficiency (<30 ng/mL). Median period of calcitriol supplementation was 30 days. Although tumor dimension did not vary, Ki67 immunoexpression decreased after supplementation. Transcriptional analysis of 15 matched pre/post-supplementation samples using U133 Plus 2.0 GeneChip (Affymetrix) revealed 18 genes over-expressed in post-supplementation tumors. As a technical validation procedure, expression of four genes was also determined by RT-qPCR and a direct correlation was observed between both methods (microarray vs PCR). To further explore the effects of near physiological concentrations of calcitriol on breast cancer samples, an ex vivo model of fresh tumor slices was utilized. Tumor samples from another 12 post-menopausal patients were sliced and treated in vitro with slightly high concentrations of calcitriol (0.5nM), that can be attained in vivo, for 24 hours In this model, expression of PBEF1, EGR1, ATF3, FOS and RGS1 was not induced after a short exposure to calcitriol. Conclusions: In our work, most post-menopausal breast cancer patients presented at least 25(OH)D3 insufficiency. In these patients, a short period of calcitriol supplementation may prevent tumor growth and reduce Ki67 expression, probably associated with discrete transcriptional changes. This observation deserves further investigation to better clarify calcitriol effects in tumor behavior under physiological conditions. Post-menopausal patients with early stage breast cancer, in the absence of distant metastasis, were invited to take part in the study. This protocol was approved by the Institutional Ethics Committee, and a written informed consent was signed by all participants. Patients had blood and tumor samples collected during biopsy, and were prescribed calcitriol supplementation, (Rocaltrol)TM 0.50 g/day PO, as recommended for osteoporosis prevention. Tumor specimens obtained during biopsy (pre-supplementation) or breast surgery (post-supplementation) were hand dissected and samples with at least 70% tumor cells were further processed. Breast surgery followed in about one month
Project description:Estrogen signaling is critical for the development and maintenance of healthy bone and age-related declines in estrogen levels leads to the development of post-menopausal osteoporosis. The large majority of bones consist of a dense outer cortical shell and an internal mesh-like network of trabecular bone which respond differently to external cues such as hormonal signaling. To date, no study has assessed the transcriptomic differences that occur specifically in cortical and trabecular bone compartments in response to hormonal changes. To investigate this, we employed a mouse model of post-menopausal osteoporosis (ovariectomy (OVX)) and estrogen replacement therapy (ERT). mRNA and miR sequencing revealed highly distinct transcriptomic profiles between cortical and trabecular bone in the setting of OVX and ERT. Through extensive bioinformatic analyses, 7 miRs were identified as most likely to contribute to the observed estrogen-mediated gene expression changes. Of these, 4 miRNAs were prioritized for further study and were shown to be capable of decreasing the expression of predicted target genes in bone cells, to be estrogen regulated, to be able to enhance the expression of osteoblast differentiation genes, and to confer alterations to the mineralization capacity of primary calvarial osteoblasts. As such, candidate miRs, and miR mimics, may have the capacity to mimic the bone beneficial responses of ERT without the unwanted side effects and therefore represent a novel class of therapeutic approaches to combat diseases related to bone loss.
Project description:Estrogen signaling is critical for the development and maintenance of healthy bone and age-related declines in estrogen levels leads to the development of post-menopausal osteoporosis. The large majority of bones consist of a dense outer cortical shell and an internal mesh-like network of trabecular bone which respond differently to external cues such as hormonal signaling. To date, no study has assessed the transcriptomic differences that occur specifically in cortical and trabecular bone compartments in response to hormonal changes. To investigate this, we employed a mouse model of post-menopausal osteoporosis (ovariectomy (OVX)) and estrogen replacement therapy (ERT). mRNA and miR sequencing revealed highly distinct transcriptomic profiles between cortical and trabecular bone in the setting of OVX and ERT. Through extensive bioinformatic analyses, 7 miRs were identified as most likely to contribute to the observed estrogen-mediated gene expression changes. Of these, 4 miRNAs were prioritized for further study and were shown to be capable of decreasing the expression of predicted target genes in bone cells, to be estrogen regulated, to be able to enhance the expression of osteoblast differentiation genes, and to confer alterations to the mineralization capacity of primary calvarial osteoblasts. As such, candidate miRs, and miR mimics, may have the capacity to mimic the bone beneficial responses of ERT without the unwanted side effects and therefore represent a novel class of therapeutic approaches to combat diseases related to bone loss.
Project description:Background: Breast cancer patients present lower 1,25(OH)2D3 or 25(OH)D3 serum levels than unaffected women. Although 1,25(OH)2D3 pharmacological concentrations of 1,25(OH)2D3 may exert antiproliferative effects in breast cancer cell lines, much uncertainty remains about the effects of calcitriol supplementation in tumor specimens in vivo. We have evaluated tumor dimension (ultrassonography), proliferative index (Ki67 expression), 25(OH)D3 serum concentration and gene expression profile, before and after a short term calcitriol supplementation (dose to prevent osteoporosis) to post-menopausal patients. Results: Thirty three patients with operable disease had tumor samples evaluated. Most of them (87.5%) presented 25(OH)D3 insufficiency (<30 ng/mL). Median period of calcitriol supplementation was 30 days. Although tumor dimension did not vary, Ki67 immunoexpression decreased after supplementation. Transcriptional analysis of 15 matched pre/post-supplementation samples using U133 Plus 2.0 GeneChip (Affymetrix) revealed 18 genes over-expressed in post-supplementation tumors. As a technical validation procedure, expression of four genes was also determined by RT-qPCR and a direct correlation was observed between both methods (microarray vs PCR). To further explore the effects of near physiological concentrations of calcitriol on breast cancer samples, an ex vivo model of fresh tumor slices was utilized. Tumor samples from another 12 post-menopausal patients were sliced and treated in vitro with slightly high concentrations of calcitriol (0.5nM), that can be attained in vivo, for 24 hours In this model, expression of PBEF1, EGR1, ATF3, FOS and RGS1 was not induced after a short exposure to calcitriol. Conclusions: In our work, most post-menopausal breast cancer patients presented at least 25(OH)D3 insufficiency. In these patients, a short period of calcitriol supplementation may prevent tumor growth and reduce Ki67 expression, probably associated with discrete transcriptional changes. This observation deserves further investigation to better clarify calcitriol effects in tumor behavior under physiological conditions.
Project description:Osteoporosis is caused by imbalanced bone remodelling homeostasis and is highly prevalent in post-menopausal women. The impact of osteoporosis on mesenchymal stromal cells (MSCs) is a key area of research as they are the progenitors of osteoblasts and are therefore critical to bone homeostasis. TBioinformatic analysis of transcriptional profiling data revealed specific misregulation of genes involved in the processing and trafficking of cellular components, as well as downregulation of Neo1 which has an important role in controlling cell fate choice. These data indicate that the therapeutic targeting of bone marrow MSCs to increase their numbers, to support the appropriate processing of cellular contents, or to redirect cell fate choice may provide new methods for the treatment of osteoporosis, thereby reducing fracture-associated morbidity and improving quality of life for the 200 million people living with osteoporosis globally.
Project description:Comparison of circulating monocytes from pre- and postmenopausal females with low or high bone mineral density (BMD). Circulating monocytes are progenitors of osteoclasts, and produce factors important to bone metabolism. Results provide insight into the role of monocytes in osteoporosis. We identify osteoporosis genes by microarray analyses of monocytes in high vs. low hip BMD (bone mineral density) subjects.