Project description:SNAI1 is a key transcription factor in the EMT process, that is considered as the initial step of metastasis. The microRNAs(miRNAs) invovled in SNAI1-induced EMT may play important roles in regulating the process of metastasis. We used microarrays to establish the miRNAs both upregulated and downregulated in SNAI1-induced EMT process.
Project description:SNAI1 is a key transcription factor in the EMT process, that is considered as the initial step of metastasis. A lot of genes invovled in SNAI1-induced EMT may play important roles in regulating the process of metastasis. We used microarrays to establish the gene expression in SNAI1-induced EMT process.
Project description:Our data demonstrate that overexpression of the polarity protein Crb3 elicits changes in MCF-10A cells that culminate in an increase in the release of amphiregulin (AR) and the subsequent activation of EGFR signaling to drive proliferation. Microarray analysis was performed to define global changes in the transcriptional landscape induced by Crb3. Results provide insight into a FERM domain protein (EBP41L4B) required for Crb3 mediated induction of proliferation.
Project description:This study investigated the use of DNA amplification fingerprinting (DAF) to identify biomarkers useful in the elucidating genetic factors that lead to carcinogenesis. The DNA amplification fingerprinting (DAF) technique was used to generate fingerprint profiles of a normal human mammary epithelial cell line (MCF-10A) and a human breast cancer cell line (MCF-7). When compared with one another, a polymorphic biomarker gene (262 base pairs (bps)) was identified in MCF-10A but was not present in MCF-7. This gene was cloned from the genomic DNA of the MCF-10A cell line, and subjected to Genbank database analysis. The analysis of the nucleotide sequence polymorphic marker (Genbank account: AC079630) shows that this biomarker has 100% homology with the nucleotide sequence of human chromosome 12 BAC RP11-476D10 (bps 19612-19353). The nucleotide sequence was used for possible protein translation product and the result obtained indicated that the gene codes for hypothetical protein XF2620. In order to evaluate the effects that the 262 bps biomarker would have on the morphology of MCF-7 cells, it was transfected into MCF-7 cells. There were observable changes in the morphology of the transfected cells. These changes included an increase in cell elongation and a decrease in cell aggregation.
Project description:p63 is critical for epithelial development yet little is known about the transcriptional programmes it regulates. The p63 transactivating (TA) isoforms contain an amino-terminal exon that encodes a p53-like transactivation domain, whereas ΔN-isoforms lack this domain but contain the common DNA binding domain (DBD), suggesting that TAp63 and ΔNp63 isoforms may have opposing functions. By characterising transcriptional changes and cellular effects following modulation of p63 expression, we have defined a vital role for p63 in cellular adhesion. Knockdown of p63 expression caused downregulation of cell adhesion-associated genes, cell detachment and anoikis in mammary epithelial cells and keratinocytes. Conversely, overexpression of the TAp63γ or ΔNp63α isoforms of p63 upregulated cell adhesion molecules, increased cellular adhesion and conferred resistance to anoikis.
Project description:p63 is critical for epithelial development yet little is known about the transcriptional programmes it regulates. The p63 transactivating (TA) isoforms contain an amino-terminal exon that encodes a p53-like transactivation domain, whereas ÎN-isoforms lack this domain but contain the common DNA binding domain (DBD), suggesting that TAp63 and ÎNp63 isoforms may have opposing functions. By characterising transcriptional changes and cellular effects following modulation of p63 expression, we have defined a vital role for p63 in cellular adhesion. Knockdown of p63 expression caused downregulation of cell adhesion-associated genes, cell detachment and anoikis in mammary epithelial cells and keratinocytes. Conversely, overexpression of the TAp63γ or ÎNp63α isoforms of p63 upregulated cell adhesion molecules, increased cellular adhesion and conferred resistance to anoikis. Total RNA was isolated 48 h after retroviral or adenoviral infection and was subjected to reverse transcription, labelling and hybridization. The knockdown samples were performed in duplicate with shRNA vector control, shRNA targetting all isoforms of p63 (shDBD) and shRNA targetting p63 isoforms containing the transactivating (TA) domains. The overexpression samples were performed in triplicate with vector control, overexpression of the ÎNp63α isoform, and overexpression of the TAp63γ isoforms.
Project description:Long-term exposure to estrogens including those in traditional hormone replacement therapy (HRT) increases the risk of developing hormone-dependent cancers. As a result, women are turning to over-the-counter (OTC) botanical dietary supplements, such as black cohosh (Cimicifuga racemosa) and hops (Humulus lupulus), as natural alternatives to HRT. The two major mechanisms which likely contribute to estrogen and/or HRT cancer risk are: the estrogen receptor-mediated hormonal pathway; and the chemical carcinogenesis pathway involving formation of estrogen quinones that damage DNA and proteins, hence initiating and promoting carcinogenesis. Because, OTC botanical HRT alternatives are in widespread use, they may have the potential for chemopreventive effects on estrogen carcinogenic pathways in vivo. Therefore, the effect of OTC botanicals on estrogen-induced malignant transformation of MCF-10A cells was studied. Cytochrome P450 catalyzed hydroxylation of estradiol at the 4-position leads to an o-quinone believed to act as the proximal carcinogen. Liquid chromatography/tandem mass spectrometry analysis of estradiol metabolites showed that 4-hydroxylation was inhibited by hops, whereas black cohosh was without effect. Estrogen-induced expression of CYP450 1B1 and CYP450 1A1 was attenuated by the hops extract. Two phenolic constituents of hops (xanthohumol, XH; 8-prenylnaringenin, 8-PN) were tested: 8-PN was a potent inhibitor, whereas XH had no effect. Finally, estrogen-induced malignant transformation of MCF-10A cells was observed to be significantly inhibited by hops (5 μg/mL) and 8-PN (50 nmol/L). These data suggest that hops extracts possess cancer chemopreventive activity through attenuation of estrogen metabolism mediated by 8-PN.
Project description:MicroRNA-7 (miR-7) is a non-coding RNA of 23-nucleotides that has been shown to act as a tumor suppressor in various cancers including breast cancer. Although there have been copious studies on the action mechanisms of miR-7, little is known about how the miR is controlled in the mammary cell. In this study, we performed a genome-wide expression analysis in miR-7-transfected MCF-10A breast cell line to explore the upstream regulators of miR-7. Analysis of the dysregulated target gene pool predicted hepatocyte growth factor (HGF) as the most plausible upstream regulator of miR-7. MiR-7 was upregulated in MCF-10A cells by HGF, and subsequently downregulated upon treatment with siRNA against HGF. However, the expression of HGF did not significantly change through either an upregulation or downregulation of miR-7 expression, suggesting that HGF acts upstream of miR-7. In addition, the target genes of miR-7, such as EGFR, KLF4, FAK, PAK1 and SET8, which are all known oncogenes, were downregulated in HGF-treated MCF-10A; in contrast, knocking down HGF recovered their expression. These results indicate that miR-7 mediates the activity of HGF to suppress oncogenic proteins, which inhibits the development of normal cells, at least MCF-10A, into cancerous cells.