Project description:7,12-Dimethylbenz[a]anthracene (DMBA)-induced rat mammary carcinoma is a well-recognized model, however, the genetic alterations during its carcinogenesis have yet to be determined. We used laser capture microdissection to specifically isolate cells from terminal end buds (TEBs), the origin of carcinoma, at 2 weeks after sesame oil- treatment (control) or DMBA-treatment (DMBA-TEBs), ductal carcinoma in situ (DCIS) and invasive mammary carcinoma (MC). Using an oligonucleotide microarray representing 20600 rat probe sequences, we analyzed gene expression profiles and validated mRNA and protein levels of genes of interest by real-time quantitative PCR, immunohistochemistry and immunofluorescence. The number of differentially expressed genes was smallest in DMBA-TEBs (63), followed by DCIS (798) and MC (981). Only the expression of PEP-19, an anti-apoptic gene, showed significant increases in DMBA-TEBs (4-fold), DCIS (10-fold) and MC (16-fold). MMP-13 expression was increased markedly in DCIS (19-fold) and MC (61-fold) while OPN expression was increased 6-fold in DCIS and 8-fold in MC. MMP-7 expression was increased 4-fold in MC. Nidogen-1; a participant in the assembly of basement membranes, TSP-2; an inhibitor of angiogenesis and COUP-TFI; a transcription repressor showed significant decreases in DCIS (4-, 9-, and 17-fold, respectively) and MC (10-, 37-, and 100-fold). Network analyses with IPA software revealed that the most significant network was centered on Akt groups in DCIS and ERK groups in MC. The present findings provide insights into the molecular changes and suggest the importance of PEP-19 overexpression very early on during mammary carcinogenesis. Keywords: Comparative experiments of sesame oil treatment(control)and 7,12-Dimethylbenz[a]anthracene(DMBA)treatment group. Or comparative experiments of tissue type
Project description:Whole transcriptome assay of whole lung of rat from 3 genetic strains (Lewis, Fisher, Brown Norway) at 3 postnatal time points (postnatal days 1, 7, 14).
Project description:Whole transcriptome assay of whole lung of rat from 3 genetic strains (Lewis, Fisher, Brown Norway) at 3 postnatal time points (postnatal days 1, 7, 14). Total RNA obtained from whole lung of rat from 3 genetic strains and 3 postnatal time points in (mainly) quadruplicate measurements per strain and time point.
Project description:7,12-Dimethylbenz[a]anthracene (DMBA)-induced rat mammary carcinoma is a well-recognized model, however, the genetic alterations during its carcinogenesis have yet to be determined. We used laser capture microdissection to specifically isolate cells from terminal end buds (TEBs), the origin of carcinoma, at 2 weeks after sesame oil- treatment (control) or DMBA-treatment (DMBA-TEBs), ductal carcinoma in situ (DCIS) and invasive mammary carcinoma (MC). Using an oligonucleotide microarray representing 20600 rat probe sequences, we analyzed gene expression profiles and validated mRNA and protein levels of genes of interest by real-time quantitative PCR, immunohistochemistry and immunofluorescence. The number of differentially expressed genes was smallest in DMBA-TEBs (63), followed by DCIS (798) and MC (981). Only the expression of PEP-19, an anti-apoptic gene, showed significant increases in DMBA-TEBs (4-fold), DCIS (10-fold) and MC (16-fold). MMP-13 expression was increased markedly in DCIS (19-fold) and MC (61-fold) while OPN expression was increased 6-fold in DCIS and 8-fold in MC. MMP-7 expression was increased 4-fold in MC. Nidogen-1; a participant in the assembly of basement membranes, TSP-2; an inhibitor of angiogenesis and COUP-TFI; a transcription repressor showed significant decreases in DCIS (4-, 9-, and 17-fold, respectively) and MC (10-, 37-, and 100-fold). Network analyses with IPA software revealed that the most significant network was centered on Akt groups in DCIS and ERK groups in MC. The present findings provide insights into the molecular changes and suggest the importance of PEP-19 overexpression very early on during mammary carcinogenesis. Keywords: Comparative experiments of sesame oil treatmentM-oM-<M-^HcontrolM-oM-<M-^Iand 7,12-Dimethylbenz[a]anthraceneM-oM-<M-^HDMBAM-oM-<M-^Itreatment group. Or comparative experiments of tissue type ExperimentM-oM-<M-^Z7,12-Dimethylbenz[a]anthracene (DMBA)-induced rat mammary carcinoma is a well-recognized model, however, the genetic alterations during carcinogenesis have yet to be determined. We used laser capture microdissection to specifically isolate the cells from terminal end buds (TEBs), the origin of MC, at 2 weeks after sesame oil-(control) or DMBA-treatment (DMBA-TEBs), ductal carcinoma in situ (DCIS) and invasive mammary carcinoma (MC). At 50 days after birth, inbred Sprague-Dawley female rats were given 1ml sesame oil (control) or 20 mg DMBA (Nacalai tesque, Inc. Kyoto Japan) dissolved in 1ml sesame oil, by gastric intubations. Animals in control group were euthanized after 2 weeks (W) and DMBA-treated group were euthanized after 2 weeks (W), 6W and 8W, respectively. From for 4 sample(control, DMBA-TEBs, DCIS, MC), we performed a hybridization repeatedly, respectively.
Project description:Analysis of genome variants for HRDP rat strains. Data integration and dissemination through RGD tools. This work is supported by R24 OD024617.
Project description:Gene expression profiles in mammary glands of different rat strains are genetically defined. Keywords: Different rat strains and Timecourse
Project description:We are using the ACI rat model of 17beta-estradiol induced mammary cancer to define the mechanisms through which estrogens contribute to breast cancer development; identify and functionally characterize the genetic variants that determine susceptibility; and define the hormone-gene-environment interactions that influence development of mammary cancer in this physiologically relevant rat model. Female ACI rats are uniquely susceptible to development of mammary cancer when treated continuously with physiologic levels of 17beta-estradiol. Induction of mammary cancer in female ACI rats occurs through a mechanism that is largely dependent upon estrogen receptor-alpha. Interval mapping analyses of progeny generated in intercrosses between susceptible ACI rats and resistant Brown Norway (BN) rats revealed seven quantitative trait loci (QTL), designated Emca3 (Estrogen-induced mammary cancer) through Emca9, each of which harbors one or more genetic determinants of mammary cancer susceptibility. Genes that reside within Emca8 on RNO5 and were differentially expressed between 17beta-estradiol treated ACI and ACI.BN-Emca8 congenic rats were identified as Emca8 candidates. Two groups of 17beta-estradiol treated female rats were compared. Five ACI and five BN.ACI-Emca8 rats were treated with 17beta-estradiol for 12 weeks. Total RNA was isolated from the mammary glands of these animals, labeled, and hybridized to Affymetrix Rat Genome 230 2.0 Arrays (Affymetrix Inc.). Significantly differentially expressed genes were found between these groups.
Project description:Selenium is an essential micronutrient in the diet of humans and other mammals. Based largely on animal studies and epidemiological evidence, selenium is purported to be a promising cancer chemopreventive agent. However, the biological mechanisms by which chemopreventive activity takes place are poorly understood. It remains unclear whether selenium acts in its elemental form, through incorporation into organic compounds, through selenoproteins or any combination of these. The purpose of this study was to determine whether selenoproteins mitigate the risk of developing chemically induced mammary cancer. Selenoprotein expression was ablated in mouse mammary epithelial cells through genetic deletion of the selenocysteine (Sec) tRNA gene (Trsp), whose product, designated selenocysteine tRNA, is required for selenoprotein translation. Trsp floxed and mouse mammary tumor virus (MMTV)-cre mice were crossed to achieve tissue-specific excision of Trsp in targeted mammary glands. Eight- to twelve-week-old second generation Trsp(fl/+);wt, Trsp(fl/+);MMTV-cre, Trsp(fl/fl);wt and Trsp(fl/fl);MMTV-cre female mice were administered standard doses of the carcinogen, 7,12-dimethylbenzylbenz[a]antracene. Our results revealed that heterozygous, Trsp(fl/+);MMTV-cre mice showed no difference in tumor incidence, tumor rate and survival compared with the Trsp(fl/+);wt mice. However, 54.8% of homozygous Trsp(fl/f)(l);MMTV-cre mice developed mammary tumors and exhibited significantly shorter survival than the corresponding Trsp(fl/fl);wt mice, where only 36.4% developed tumors. Loss of the homozygous Trsp alleles was associated with the reduction of selenoprotein expression. The results suggest that mice with reduced selenoprotein expression have increased susceptibility to developing carcinogen-induced mammary tumors and that a major protective mechanism against carcinogen-induced mammary cancer requires the expression of these selenoproteins.
Project description:We are using the ACI rat model of 17beta-estradiol induced mammary cancer to define the mechanisms through which estrogens contribute to breast cancer development; identify and functionally characterize the genetic variants that determine susceptibility; and define the hormone-gene-environment interactions that influence development of mammary cancer in this physiologically relevant rat model. Female ACI rats are uniquely susceptible to development of mammary cancer when treated continuously with physiologic levels of 17beta-estradiol. Induction of mammary cancer in female ACI rats occurs through a mechanism that is largely dependent upon estrogen receptor-alpha. Interval mapping analyses of progeny generated in intercrosses between susceptible ACI rats and resistant Brown Norway (BN) rats revealed seven quantitative trait loci (QTL), designated Emca3 (Estrogen-induced mammary cancer) through Emca9, each of which harbors one or more genetic determinants of mammary cancer susceptibility. Genes that reside within Emca8 on RNO5 and were differentially expressed between 17beta-estradiol treated ACI and ACI.BN-Emca8 congenic rats were identified as Emca8 candidates.