«Short generation times and
high mutation rates associated with short lifespan and fast growth enable new species to appear at a faster rate in the tropics,» he says.
Yet despite all the fanfare about them, these drugs rarely cure anyone, because cancer cells»
high mutation rate allows them to dodge the pathway concerned.
The investigators systematically ruled out mundane explanations, such as cross-pollination of a mutant plant by a normal one, an
extremely high mutation rate or the presence of another, hidden copy of hothead.
The variation suggests that in some species, genes that
cause high mutation rates — for instance, by interfering with DNA repair — go unchecked.
The mtDNA has a
much higher mutation rate than nuclear DNA, which by itself might imperil species survival, because most DNA mutations are deleterious.
The high mutation rate led to fears at the time that if the virus rapidly altered, it could also quickly become more virulent.
This may help explain
the high mutation rate that allows the virus to escape from immune responses, says Mr. Law.
RNA viruses pose a significant public health problem worldwide because
their high mutation rate allows them to escape the immune response.
The high mutation rate in mtDNA plus ovarian selection thus provide a powerful tool for humans (and animals) to adapt to an environmental change, without endangering a population's overall survival.
This rapid, malignant metastatic formation of melanoma, was previously put down to
the high mutation rate that is characteristic of melanoma, i.e. genetic changes that stimulate the growth of cancer cells.
However, the enzyme isn't something that acts once — it is chronically elevated along with HPV infection, leading to years or decades of
higher mutation rates.
«Rats have
a higher mutation rate [than humans], so you get these different [families] developing in Polynesia,» he says.
What we did not know was that BCC is also the cancer with
the highest mutation rates.
CLL was an appealing model for this study because
its high mutation rate in the short stretch of DNA that encodes the IG heavy chain (IGH).
The hypermutated microsatellite instability group exhibited
a high mutation rate, as well as few copy number alterations, but did not carry mutations in the POLE gene.
«Cancer cells by definition have
high mutation rates and genomic instability even at the very earliest stages, so you could imagine building a virus that could destroy even the earliest lesions and be used as a prophylactic,» says O'Shea.
Although clinical trials have collectively shown a disease control rate of approximately 45 percent using this approach in ovarian cancer, they have yet to establish selective benefit in BRCA1 / 2 - deficient cancers, which should generate stronger anti-tumor immune responses given
their higher mutation rate.
Yet, this is unlikely to succeed because of
the high mutation rate of this virus.