9 research outputs found
Maintenance of cell type-specific connectivity and circuit function requires Tao kinase
Sensory circuits are typically established during early development, yet how circuit specificity and function are maintained during organismal growth has not been elucidated. To gain insight we quantitatively investigated synaptic growth and connectivity in the Drosophila nociceptive network during larval development. We show that connectivity between primary nociceptors and their downstream neurons scales with animal size. We further identified the conserved Ste20-like kinase Tao as a negative regulator of synaptic growth required for maintenance of circuit specificity and connectivity. Loss of Tao kinase resulted in exuberant postsynaptic specializations and aberrant connectivity during larval growth. Using functional imaging and behavioral analysis we show that loss of Tao-induced ectopic synapses with inappropriate partner neurons are functional and alter behavioral responses in a connection-specific manner. Our data show that fine-tuning of synaptic growth by Tao kinase is required for maintaining specificity and behavioral output of the neuronal network during animal growth
STRATEGIES TO PREDICT TREATMENT RESPONSE AND SELECT THERAPIES IN METASTATIC BREAST CANCER PATIENTS USING A NEXT GENERATION SEQUENCING (NGS) MULTI-GENE PANEL
The standard of care for many
patients with advanced breast
cancer (BC )is gradually
evolving from empirical
treatment based on clinicalpathological
characteristics to
the use of targeted approaches
based on the molecular profile
of the tumor.
In the last decade, an
increasing number of
molecularly targeted drugs
have been developed for the
treatment of metastatic BC.
These drugs target specific
molecular abnormalities that
confer to cancer cells a survival
advantage [1]. Interestingly,
the ability to perform multigene
testing for a range of
molecular alterations may
provide an opportunity to
clarify the mechanisms of
treatment response, to find the
strategies to overcome
treatment resistance and thus,
to identify patients who are
more likely to develop relapse
and who may be candidates for
matched targeted therapies
[2-3].
The main aim of this study is to
find prognostic and predictive
molecular biomarkers for the
management of metastatic BC
patients in clinical practice. MATERIALS AND
METHODS
The amplicon-sequencing
analyses took advantage of the Ion
AmpliSeq™ technology (Thermo
Fisher, Waltham, MA, USA). A
custom panel was designed with
the help of the Designer online
tool (www.ampliseq.com),
which was employed to generate
optimized primers encompassing
the coding DNA sequences (with
100bp of exon padding and the
UTRs regions) of 25 genes in the
Human Reference Genome
(hg19); these genes were selected
searching and screening scientific
literature for treatments
resistance in BC and are reported
in Table 1. Primer pairs were
divided into two pools to
optimize multiplex PCR
conditions and the coverage, that
assessed to 89.02%. The
customized Ion AmpliSeq panel
was employed on samples from 7
primary BC samples and matched
metastatic sites (3 skin, 3 lymph
node and 1 lung metastases).
They were all processed using the
Ion AmpliSeq Library Kit 2.0,
starting from 15 nanograms of
FFPE extracted DNA/pool.
Samples were barcoded with the
Ion Express Kit to optimize
matched patients pooling on the
same 318 Chip v2 sequencing
chip. The template-positive Ion
Sphere Particles were sequenced
on a Personal Genome Machine
(Thermo Fisher, Waltham, MA,
USA). RESULTS The mutation profiles of paired primary and
secondary tumors of the seven patients enrolled in
this study are presented in Table 2. Ten different
genes (PTEN, PIK3CA, mTOR, ERBB2, ERBB3,
MET, INPP4B, MAP2K1, CDK6, KRAS) in 6
different patients showed possible damaging
variants as shown in Table 2.
• Four patients (number 1, 3, 5 and 6) showed no
additional or different mutations in secondary
tumors if compared to primary samples.
• In patient number 2, the metastatic site
presented new mutations if compared to the
primary tumor.
• Finally in patient number 4 and 7 we did not
detect in metastases some of the mutations
found in the primary tumor. DISCUSSION
In 5 patients (71,4%) the mutational status of primary tumor could explain treatment resistance and thus
predict relapse, in one patient the mutational status of the new subclones could be relevant for guiding
differently the subsequent treatment choices.
In 2 patients (28,5%) we were not able to detect in metastases some of the mutations found in the primary
tumor. This could be explained by considering the clonal evolution of metastases.
These preliminary data suggest that the multi-gene panel analysis of primary and secondary tumors may help
clinicians:
• in discriminating BC patients HR+ and/or HER2+ with mutations predicting an increased risk of adjuvant
treatment resistance and thus relapse
• in guiding treatment selection strategies in the metastatic setting.
The study is still open and we are currently recruiting other patients.The main aim of this study is to find prognostic and predictive molecular biomarkers for the management of metastatic BC patients in clinical practice. The preliminary data suggest that the multi-gene panel analysis of primary and secondary tumors may help clinicians: • in discriminating BC patients HR+ and/or HER2+ with mutations predicting an increased risk of adjuvant treatment resistance and thus relapse • in guiding treatment selection strategies in the metastatic setting. The study is still open and we are currently recruiting other patients
STRATEGIES TO PREDICT TREATMENT RESPONSE AND SELECT THERAPIES IN METASTATIC BREAST CANCER PATIENTS USING A NEXT GENERATION SEQUENCING MULTI-GENE PANEL
The standard of care for many
patients with advanced breast
cancer (BC )is gradually
evolving from empirical
treatment based on clinicalpathological
characteristics to
the use of targeted approaches
based on the molecular profile
of the tumor.
In the last decade, an
increasing number of
molecularly targeted drugs
have been developed for the
treatment of metastatic BC.
These drugs target specific
molecular abnormalities that
confer to cancer cells a survival
advantage. Interestingly,
the ability to perform multigene
testing for a range of
molecular alterations may
provide an opportunity to
clarify the mechanisms of
treatment response, to find the
strategies to overcome
treatment resistance and thus,
to identify patients who are
more likely to develop relapse
and who may be candidates for
matched targeted therapies.
The main aim of this study is to
find prognostic and predictive
molecular biomarkers for the
management of metastatic BC
patients in clinical practice
Cell-Autonomous Control of Neuronal Dendrite Expansion via the Fatty Acid Synthesis Regulator SREBP
Summary: During differentiation, neurons require a high lipid supply for membrane formation as they elaborate complex dendritic morphologies. While glia-derived lipids support neuronal growth during development, the importance of cell-autonomous lipid production for dendrite formation has been unclear. Using Drosophila larva dendritic arborization (da) neurons, we show that dendrite expansion relies on cell-autonomous fatty acid production. The nociceptive class four (CIV) da neurons form particularly large space-filling dendrites. We show that dendrite formation in these CIVda neurons additionally requires functional sterol regulatory element binding protein (SREBP), a crucial regulator of fatty acid production. The dendrite simplification in srebp mutant CIVda neurons is accompanied by hypersensitivity of srebp mutant larvae to noxious stimuli. Taken together, our work reveals that cell-autonomous fatty acid production is required for proper dendritic development and establishes the role of SREBP in complex neurons for dendrite elaboration and function. : Ziegler et al. highlight the endogenous role of fatty acid synthesis for proper neuronal dendrite growth during development. Using Drosophila da neurons, they show that large CIVda neurons cell-autonomously rely on fatty acid synthesis through the lipid synthesis master regulator SREBP. Keywords: Drosophila, dendrite differentiation, fatty acids, lipids, SREBP, metabolism, brain, nociceptio
BiPOLES is an optogenetic tool developed for bidirectional dual-color control of neurons
International audienceOptogenetic manipulation of neuronal activity through excitatory and inhibitory opsins has become an indispensable experimental strategy in neuroscience research. For many applications bidirectional control of neuronal activity allowing both excitation and inhibition of the same neurons in a single experiment is desired. This requires low spectral overlap between the excitatory and inhibitory opsin, matched photocurrent amplitudes and a fixed expression ratio. Moreover, independent activation of two distinct neuronal populations with different optogenetic actuators is still challenging due to blue-light sensitivity of all opsins. Here we report BiPOLES, an optogenetic tool for potent neuronal excitation and inhibition with light of two different wavelengths. BiPOLES enables sensitive, reliable dual-color neuronal spiking and silencing with single- or two-photon excitation, optical tuning of the membrane voltage, and independent optogenetic control of two neuronal populations using a second, blue-light sensitive opsin. The utility of BiPOLES is demonstrated in worms, flies, mice and ferrets