However, the impact of the two methylation - regulating enzymes was still seen at 10 to 15 months, when scientists found decreased expression of hundreds of genes — many of which are key tumor
suppressor genes such as BMP3, SFRP2 and GATA4 — in the smoke - exposed cells and a five - or - more-fold increase in the signaling of the KRAS oncogene that is known to be mutated in smoking - related lung cancers.
Not exact matches
«Our data strongly suggest that KIF1Bβ, which is localized on chromosome 1p36, might be
such a neuroblastoma tumor
suppressor gene,» says principal investigator Susanne Schlisio at the Department of Microbiology, Tumor and Cell Biology at Karolinska Institutet and Assistant Member at the Ludwig Institute for Cancer Research in Stockholm, Sweden.
In this research, the group looked at two variants of miR - 21, a microRNA «oncomiR» known to target tumor
suppressor genes and which is highly expressed in a number of cancers as well as other proliferative diseases
such as psoriasis.
Rather than target a tumor -
suppressor gene directly, Ideker and team took the approach of identifying genetic interactions between a tumor
suppressor gene and another
gene,
such that simultaneous disruption of both
genes selectively kills cancer cells.
Inhibition of transcription (blockade of water) on tumor
suppressor genes,
such as p21, leads to cell transformation (growth of the cactus - like eremophytes instead of normal plants from the drought).
This phenomenon could result in breakage in the human genome, and when a breakage impacts important
genes,
such as tumor
suppressors, it could lead to cancer development.
In some cases, a
gene can act as a growth promoter in cancer, and in other cases,
such as head and neck cancer, the same
gene behaves as a growth
suppressor,» said Kinzler.
Because DDX3 exhibits tumor
suppressor functions,
such as a growth - suppressive property and transcriptional activation of the p21waf1 / cip1 promoter, and is inactivated through down - regulation of
gene expression or alteration of subcellular localization in tumor cells, all these features together suggest that DDX3 might be a candidate tumor
suppressor.
During his 11 years of extensive work experience in the fields of cell and cancer biology (including work on the famous tumor
suppressor gene BRCA1), and biochemistry he has successfully published in peer - reviewed journals
such as Molecular and Cell Biology and Cancer Research.
In response to cellular stress
such as DNA damage, oncogene activation, transcriptional inhibition, and hypoxia, tumor
suppressor p53 is activated and expressed, and acts as a transcription factor to induce its target
genes [1], thereby playing a central role in the regulation of DNA repair, cell cycle, apoptosis, senescence, and angiogenesis [2 - 4].
Genetic mutations that alter tumor
suppressors such as the p53
gene are known to help tumors grow, and epigenetic modifications, too, can deactivate
genes like this one.
These
suppressor genes are inactivated in tumors, and since cancer drugs work by reducing the activity of enzymes, they won't work on
such suppressors because a drug can't inhibit a
gene that is already inactivated.»