2 research outputs found
An Optimized RAD51 Inhibitor That Disrupts Homologous Recombination without Requiring Michael Acceptor Reactivity
Homologous recombination (HR) is an essential process
in cells
that provides repair of DNA double-strand breaks and lesions that
block DNA replication. RAD51 is an evolutionarily conserved protein
that is central to HR. Overexpression of RAD51 protein is common in
cancer cells and represents a potential therapeutic target in oncology.
We previously described a chemical inhibitor of RAD51, called RI-1
(referred to as compound <b>1</b> in this report). The chloromaleimide
group of this compound is thought to act as a Michael acceptor and
react with the thiol group on C319 of RAD51, using a conjugate addition–elimination
mechanism. In order to reduce the likelihood of off-target effects
and to improve compound stability in biological systems, we developed
an analogue of compound <b>1</b> that lacks maleimide-based
reactivity but retains RAD51 inhibitory activity. This compound, 1-(3,4-dichlorophenyl)-3-(4-methoxyphenyl)-4-morpholino-1<i>H</i>-pyrrole-2,5-dione, named RI-2 (referred to as compound <b>7a</b> in this report), appears to bind reversibly to the same
site on the RAD51 protein as does compound <b>1</b>. Like compound <b>1</b>, compound <b>7a</b> specifically inhibits HR repair
in human cells
Metabolic Lipids in Melanoma Enable Rapid Determination of Actionable BRAF-V600E Mutation with Picosecond Infrared Laser Mass Spectrometry in 10 s
Rapid molecular profiling of biological
tissues with picosecond
infrared laser mass spectrometry (PIRL-MS) has enabled the detection
of clinically important histologic types and molecular subtypes of
human cancers in as little as 10 s of data collection and analysis
time. Utilizing an engineered cell line model of actionable BRAF-V600E
mutation, we observed statistically significant differences in 10
s PIRL-MS molecular profiles between BRAF-V600E and BRAF-wt cells.
Multivariate statistical analyses revealed a list of mass-to-charge
(m/z) values most significantly
responsible for the identification of BRAF-V600E mutation status in
this engineered cell line that provided a highly controlled testbed
for this observation. These metabolites predicted BRAF-V600E expression
in human melanoma cell lines with greater than 98% accuracy. Through
chromatography and tandem mass spectrometry analysis of cell line
extracts, a 30-member “metabolite array” was characterized
for determination of BRAF-V600E expression levels in subcutaneous
melanoma xenografts with an average sensitivity and specificity of
95.6% with 10 s PIRL-MS analysis. This proof-of-principle work warrants
a future large-scale study to identify a metabolite array for 10 s
determination of actionable BRAF-V600E mutation in human tissue to
guide patient care