Project description:Indole-3-carbinol (I3C) is a natural anti-carcinogenic compound found at high concentrations in Brassica vegetables. ER-positive cell lines demonstrated the greatest sensitivity to the anti-tumor effects of I3C compared to ER-negative breast cancer cell lines. Gene expression analysis was performed to identify genes and pathways that accounted for sensitivity to I3C. Microarray analysis performed using Illumina HT-12 v4 expression arrays A total of 36 samples were analyzed with six breast cancer cell lines treated with either the vehicle control or the drug Indole-3-carbinol in triplicate. The cell lines were: MCF-7, T47D, ZR751(sensitive to the drug, apoptosis/growth arrest) and MDA-MB-231, MDA-MB-157, and MDA-MB-436 (insensitive to the drug). Sensitive cell lines are of the luminal subtype and insensitive cell lines are of the basal subtype.
Project description:Indole-3-carbinol is used as a dietary supplement and has potential use as a therapeutic agent for the prevention of various types of cancer. While substantial evidence exists that indole-3-carbinol can reduce the risk of cancers induced by several known carcinogens when administered to animals, indole-3-carbinol can also function as an initiator and tumor promoter in certain models. The carcinogenic potential of indole-3-carbinol has not been studied in a 2-year bioassay. The objective of the microarray study was to evaluate the transcriptional changes in liver from rats exposed to 0 or 300 mg/kg indole-3-carbinol. At 3 months, livers were analyzed from female Harlan Sprague Dawley rats in the 2-year gavage study of indole-3-carbinol. Female rats were administered 300 mg indole-3-carbinol/kg body weight in corn oil by gavage, 5 days per week in a 2 year toxicology study of indole-3-carbinol. Gene expression studies were performed on rat liver with samples hybridized to whole rat genome RG230_2.0 rat GeneChip arrays (Affymetrix, CA).
Project description:Indole-3-carbinol is used as a dietary supplement and has potential use as a therapeutic agent for the prevention of various types of cancer. While substantial evidence exists that indole-3-carbinol can reduce the risk of cancers induced by several known carcinogens when administered to animals, indole-3-carbinol can also function as an initiator and tumor promoter in certain models. The carcinogenic potential of indole-3-carbinol has not been studied in a 2-year bioassay. The objective of the microarray study was to evaluate the transcriptional changes in liver from rats exposed to 0 or 300 mg/kg indole-3-carbinol. At 3 months, livers were analyzed from female Harlan Sprague Dawley rats in the 2-year gavage study of indole-3-carbinol.
Project description:Indole-3-carbinol (I3C) is a natural anti-carcinogenic compound found at high concentrations in Brassica vegetables. ER-positive cell lines demonstrated the greatest sensitivity to the anti-tumor effects of I3C compared to ER-negative breast cancer cell lines. Gene expression analysis was performed to identify genes and pathways that accounted for sensitivity to I3C. Microarray analysis performed using Illumina HT-12 v4 expression arrays
Project description:Dysregulated estrogen and estrogen receptor (ER)-induced gene transcription is tightly associated with estrogen receptor alpha (ERα)-positive breast carcinogenesis. ERα-occupied enhancers, particularly super enhancers, have been suggested to play a vital role in such transcriptional events. However, the landscape of ERα-occupied super enhancers (ERSEs) as well as key super enhancer-associated genes remain to be fully characterized. Here, we defined the landscape of ERSEs in MCF7, a ERα-positive breast cancer cell line, and demonstrated that bromodomain protein BRD4 is a master regulator of the transcriptional activation of ERSE and cognate ERα-target genes. Furthermore, RET, a member of the tyrosine protein kinase family of proteins, was identified to be a key target gene of BRD4-regulated ERSEs, which is vital for estrogen/ ERα-induced gene transcriptional activation and malignant phenotypes through activating the Ras-Raf-MEK-ERK-p90RSK-ERα phosphorylation cascade. Accordingly, combination therapy with BRD4 and RET inhibitors exhibited synergistic effects on suppressing ERα-positive breast cancer both in vitro and in vivo. Taken together, our data uncovered the critical role of a super enhancer-associated BRD4/ERα-RET-ERα positive feedback loop in ERα-positive breast cancer, and targeting components in this loop will provide new therapeutic avenue for treating ERα-positive breast cancer in the clinic.
Project description:Dysregulated estrogen and estrogen receptor (ER)-induced gene transcription is tightly associated with estrogen receptor alpha (ERα)-positive breast carcinogenesis. ERα-occupied enhancers, particularly super enhancers, have been suggested to play a vital role in such transcriptional events. However, the landscape of ERα-occupied super enhancers (ERSEs) as well as key super enhancer-associated genes remain to be fully characterized. Here, we defined the landscape of ERSEs in MCF7, a ERα-positive breast cancer cell line, and demonstrated that bromodomain protein BRD4 is a master regulator of the transcriptional activation of ERSE and cognate ERα-target genes. Furthermore, RET, a member of the tyrosine protein kinase family of proteins, was identified to be a key target gene of BRD4-regulated ERSEs, which is vital for estrogen/ ERα-induced gene transcriptional activation and malignant phenotypes through activating the Ras-Raf-MEK-ERK-p90RSK-ERα phosphorylation cascade. Accordingly, combination therapy with BRD4 and RET inhibitors exhibited synergistic effects on suppressing ERα-positive breast cancer both in vitro and in vivo. Taken together, our data uncovered the critical role of a super enhancer-associated BRD4/ERα-RET-ERα positive feedback loop in ERα-positive breast cancer, and targeting components in this loop will provide new therapeutic avenue for treating ERα-positive breast cancer in the clinic.
Project description:Dysregulated estrogen and estrogen receptor (ER)-induced gene transcription is tightly associated with estrogen receptor alpha (ERα)-positive breast carcinogenesis. ERα-occupied enhancers, particularly super enhancers, have been suggested to play a vital role in such transcriptional events. However, the landscape of ERα-occupied super enhancers (ERSEs) as well as key super enhancer-associated genes remain to be fully characterized. Here, we defined the landscape of ERSEs in MCF7, a ERα-positive breast cancer cell line, and demonstrated that bromodomain protein BRD4 is a master regulator of the transcriptional activation of ERSE and cognate ERα-target genes. Furthermore, RET, a member of the tyrosine protein kinase family of proteins, was identified to be a key target gene of BRD4-regulated ERSEs, which is vital for estrogen/ ERα-induced gene transcriptional activation and malignant phenotypes through activating the Ras-Raf-MEK-ERK-p90RSK-ERα phosphorylation cascade. Accordingly, combination therapy with BRD4 and RET inhibitors exhibited synergistic effects on suppressing ERα-positive breast cancer both in vitro and in vivo. Taken together, our data uncovered the critical role of a super enhancer-associated BRD4/ERα-RET-ERα positive feedback loop in ERα-positive breast cancer, and targeting components in this loop will provide new therapeutic avenue for treating ERα-positive breast cancer in the clinic.
Project description:PI3K/AKT pathway plays one of pivotal roles in breast cancer development and maintenance. PIK3CA, coding PIK3 catalytic subunit, is the oncogene which shows the high frequency of gain-of-function mutations leading to the PI3K/AKT pathway activation in breast cancer. In particular in the ERα-positive breast tumors PIK3CA mutations have been observed in 30% to 40%. However, genes expressed in connection to the pathway activation in breast tumorigenesis remain largely unknown. To identify downstream relevant target genes (and signaling pathways) turned on by the aberrant PI3K/AKT signal in breast tumors, we analyzed gene expression by pangenomic oligonucleotide microarray in a series of 43 ERα-positive tumors with and without PIK3CA mutations. 43 ERα-positive breast tumors including 14 tumors with PIK3CA mutations and 29 tumors without PIK3CA mutattions were used as screening set for microarray.