Publications by authors named "Michiko Nishigaki"
Although hypomethylation was the originally identified epigenetic change in cancer, it was overlooked for many years in preference to hypermethylation. Recently, gene activation by cancer-linked hypomethylation has been rediscovered. However, in gastric cancer, genome-wide screening of the activated genes has not been found.
View Article and Find Full Text PDFAlternative mechanisms of gene amplification in human cancers.
Genes Chromosomes Cancer
October 2004
Article Synopsis
- * Research on the 17q21 locus revealed a different type of amplification, where sequences are arranged in a head-to-tail manner instead of the head-to-head configuration typically associated with BFB cycles.
- * The discovery of consistent junctions between amplicon repeats in cancer cells suggests that there are alternative mechanisms driving oncogene amplification beyond the BFB model.
We developed a DNA microarray to evaluate the estrogen activity of natural estrogens and industrial chemicals. Using MCF-7 cells, we conducted a comprehensive analysis of estrogen-responsive genes among approximately 20,000 human genes. On the basis of reproducible and reliable responses of the genes to estrogen, we selected 172 genes to be used for developing a customized DNA microarray.
View Article and Find Full Text PDFIntroduction: Reporter gene assays are useful means for monitoring cellular responses. We report here a reporter gene assay for evaluating and monitoring estrogen activities by estrogen-like compounds and xenoestrogens, which is based on the promoters from the human estrogen receptor alpha (ERalpha) gene.
Methods: The reporter gene constructs contained a proximal promoter region (containing promoters A and B: ProAB) or either of promoters C to F (ProC, ProD, ProE, and ProF) or fused minor promoters (ProCDEF).
Article Synopsis
- The study focuses on analyzing mRNAs from a small number of cells, which is vital for understanding gene expression in health and disease.
- Researchers developed a new method called TALPAT that amplifies mRNA from as few as 100 cells using T7 RNA polymerase and other techniques, allowing for detailed gene expression profiling.
- TALPAT showed high reproducibility in identifying significant gene changes in gastric cancer cells and helped analyze cell interactions in their microenvironment.
Article Synopsis
- Researchers found that the CAB1 and c-ERBB-2 genes are part of a frequently amplified area on chromosome 17q12, which is linked to various cancers.
- They cloned a gene called CAB2, similar to a yeast gene that helps fix DNA damage.
- The study shows that CAB2 may reduce intercellular manganese (Mn2+) levels by moving it into cellular vesicles, marking the first comprehensive identification of genes in this amplified region associated with breast and gastric cancers.