FIRE-3 compared first-line therapy with FOLFIRI plus either cetuximab or bevacizumab in 592 KRAS exon 2 wild-type metastatic colorectal cancer (mCRC) patients. The consensus molecular subgroups (CMS) ...are grouping CRC samples according to their gene-signature in four different subtypes. Relevance of CMS for the treatment of mCRC has yet to be defined.
In this exploratory analysis, patients were grouped according to the previously published tumor CRC-CMSs. Objective response rates (ORR) were compared using chi-square test. Overall survival (OS) and progression-free survival (PFS) times were compared using Kaplan–Meier estimation, log-rank tests. Hazard ratios (HR) were estimated according to the Cox proportional hazard method.
CMS classification could be determined in 438 out of 514 specimens available from the intent-to-treat (ITT) population (n-=-592). Frequencies for the remaining 438 samples were as follows: CMS1 (14%), CMS2 (37%), CMS3 (15%), CMS4 (34%). For the 315 RAS wild-type tumors, frequencies were as follows: CMS1 (12%), CMS2 (41%), CMS3 (11%), CMS4 (34%). CMS distribution in right- versus (vs) left-sided primary tumors was as follows: CMS1 (27% versus 11%), CMS2 (28% versus 45%), CMS3 (10% versus 12%), CMS4 (35% versus 32%). Independent of the treatment, CMS was a strong prognostic factor for ORR (P-=-0.051), PFS (P-<-0.001), and OS (P-<-0.001). Within the RAS wild-type population, OS observed in CMS4 significantly favored FOLFIRI cetuximab over FOLFIRI bevacizumab. In CMS3, OS showed a trend in favor of the cetuximab arm, while OS was comparable in CMS1 and CMS2, independent of targeted therapy.
CMS classification is prognostic for mCRC. Prolonged OS induced by FOLFIRI plus cetuximab versus FOLFIRI plus bevacizumab in the FIRE-3 study appears to be driven by CMS3 and CMS4. CMS classification provides deeper insights into the biology to CRC, but at present time has no direct impact on clinical decision-making.
The FIRE-3 (AIO KRK-0306) study had been registered at ClinicalTrials.gov: NCT00433927.
Neocortical epilepsy is frequently drug-resistant. Surgery to remove the epileptogenic zone is only feasible in a minority of cases, leaving many patients without an effective treatment. We report ...the potential efficacy of gene therapy in focal neocortical epilepsy using a rodent model in which epilepsy is induced by tetanus toxin injection in the motor cortex. By applying several complementary methods that use continuous wireless electroencephalographic monitoring to quantify epileptic activity, we observed increases in high frequency activity and in the occurrence of epileptiform events. Pyramidal neurons in the epileptic focus showed enhanced intrinsic excitability consistent with seizure generation. Optogenetic inhibition of a subset of principal neurons transduced with halorhodopsin targeted to the epileptic focus by lentiviral delivery was sufficient to attenuate electroencephalographic seizures. Local lentiviral overexpression of the potassium channel Kv1.1 reduced the intrinsic excitability of transduced pyramidal neurons. Coinjection of this Kv1.1 lentivirus with tetanus toxin fully prevented the occurrence of electroencephalographic seizures. Finally, administration of the Kv1.1 lentivirus to an established epileptic focus progressively suppressed epileptic activity over several weeks without detectable behavioral side effects. Thus, gene therapy in a rodent model can be used to suppress seizures acutely, prevent their occurrence after an epileptogenic stimulus, and successfully treat established focal epilepsy.
Cortical information processing requires a delicate balance of excitatory and inhibitory signaling. How is this balance preserved during hippocampal memory encoding, which involves NMDA ...receptor-dependent long term potentiation (LTP)? This form of LTP occurs at synapses between pyramidal neurons but has not been detected in feed-forward inhibitory interneurons. We show that paired pre- and postsynaptic activity evokes pathway-specific LTP in half of rat stratum radiatum interneurons if cytoplasmic integrity is preserved. LTP occurs in aspiny feed-forward interneurons and propagates to pyramidal neurons as an enhancement of disynaptic inhibition. We also show that when LTP is restricted to synapses on pyramidal neurons, the temporal fidelity of synaptic integration and action potential generation in pyramidal cells is compromised. However, when LTP also occurs at synapses on feed-forward interneurons, temporal fidelity is preserved. We propose that Hebbian LTP at synapses driving disynaptic inhibition is necessary to maintain information processing without degradation during memory encoding.
Steroid receptors activate and repress genes. An important class of genes that they repress is controlled by the transcription factor AP‐1. The activity of AP‐1 is inhibited by the receptor, a ...mechanism exploited for the therapy of various forms of pathological hyperproliferation in humans. We show here by point mutations in the DNA binding domain and by the choice of steroid ligands that repression of AP‐1 activity and transactivation functions of the glucocorticoid receptor (GR) are separable entities. While DNA binding and activation of glucocorticoid‐regulated promoters require GR dimerization, we present data that suggest that repression is a function of GR monomers.
The presence of peritoneal carcinomatosis arising from colorectal cancer is associated with a poor prognosis. It was the purpose of this study to analyze morbidity, mortality, and survival after ...major cytoreductive surgery and intraperitoneal chemotherapy.
Thirty-two patients with peritoneal carcinomatosis were operated between April 2004 and June 2006 with the aim of complete macroscopical cytoreduction. All had a primary colorectal carcinoma. Surgery in these patients was followed by hyperthermic intraperitoneal chemotherapy (HIPEC) consisting of mitomycin C and doxorubicin. Data were analyzed retrospectively.
Of all patients, 16 had appendix and 16 non-appendiceal colorectal carcinoma. A macroscopically complete cytoreduction was achieved in 24 patients by parietal and visceral peritonectomy procedures. All resections were combined with HIPEC. Overall morbidity was 34%. Most frequent surgical complications were intestinal obstruction (4/32), enteric fistula (2/32), pancreatitis (2/32), and bile leakage (2/32). One patient presented grade 4 renal toxicity. There was no hospital mortality. The median follow-up was 12 months. The 1-year overall survival rate is 96%. All patients after complete cytoreduction are still alive.
Cytoreductive surgery combined with HIPEC is associated with an acceptable morbidity and low mortality. Complete cytoreduction may improve survival, particularly in well-selected patients having a low tumor volume and no extra-abdominal metastases.
The potassium-chloride co-transporter KCC2, encoded by SLC12A5, plays a fundamental role in fast synaptic inhibition by maintaining a hyperpolarizing gradient for chloride ions. KCC2 dysfunction has ...been implicated in human epilepsy, but to date, no monogenic KCC2-related epilepsy disorders have been described. Here we show recessive loss-of-function SLC12A5 mutations in patients with a severe infantile-onset pharmacoresistant epilepsy syndrome, epilepsy of infancy with migrating focal seizures (EIMFS). Decreased KCC2 surface expression, reduced protein glycosylation and impaired chloride extrusion contribute to loss of KCC2 activity, thereby impairing normal synaptic inhibition and promoting neuronal excitability in this early-onset epileptic encephalopathy.
Motor neurons (MNs) and astrocytes (ACs) are implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS), but their interaction and the sequence of molecular events leading to MN death ...remain unresolved. Here, we optimized directed differentiation of induced pluripotent stem cells (iPSCs) into highly enriched (> 85%) functional populations of spinal cord MNs and ACs. We identify significantly increased cytoplasmic TDP-43 and ER stress as primary pathogenic events in patient-specific valosin-containing protein (VCP)-mutant MNs, with secondary mitochondrial dysfunction and oxidative stress. Cumulatively, these cellular stresses result in synaptic pathology and cell death in VCP-mutant MNs. We additionally identify a cell-autonomous VCP-mutant AC survival phenotype, which is not attributable to the same molecular pathology occurring in VCP-mutant MNs. Finally, through iterative co-culture experiments, we uncover non-cell-autonomous effects of VCP-mutant ACs on both control and mutant MNs. This work elucidates molecular events and cellular interplay that could guide future therapeutic strategies in ALS.
Display omitted
•Robust and enriched motor neurogenesis and astrogliogenesis from human iPSCs•VCP-mutant motor neurons show TDP-43 mislocalization and ER stress as early pathogenic events•VCP-mutant astrocytes exhibit a cell-autonomous survival phenotype•VCP-mutations perturb the ability of astrocytes to support motor neuron survival
Hall et al. use iPSCs to examine the sequence of events by which motor neurons degenerate in a genetic form of ALS. They find that astrocytes, a type of supportive cell, also degenerate under these conditions. The ALS-causing mutation disrupts the ability of astrocytes to promote survival of motor neurons.
PDF
