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Oncogenic forms of KRAS proteins are known to be drivers of pancreatic, colorectal, and lung cancers. The goal of this study is to identify chemical leads that inhibit oncogenic KRAS signaling. We first developed an isogenic panel of mouse embryonic fibroblast (MEF) cell lines that carry wild-type RAS, oncogenic KRAS, and oncogenic BRAF. We validated these cell lines by screening against a tool compound library of 1402 annotated inhibitors in an adenosine triphosphate (ATP)-based cell viability assay. Subsequently, this MEF panel was used to conduct a high-throughput phenotypic screen in a cell viability assay with a proprietary compound library. All 126 compounds that exhibited a selective activity against mutant KRAS were selected and prioritized based on their activities in secondary assays. Finally, five chemical clusters were chosen. They had specific activity against SW620 and LS513 over Colo320 colorectal cancer cell lines. In addition, they had no effects on BRAFV600E, MEK1, extracellular signal-regulated kinase 2 (ERK2), phosphoinositide 3-kinase alpha (PI3Kα), AKT1, or mammalian target of rapamycin (mTOR) as tested in in vitro enzymatic activity assays. Biophysical assays demonstrated that these compounds did not bind directly to KRAS. We further identified the mechanism of action and showed that three of them have CDK9 inhibitory activity. In conclusion, we have developed and validated an isogenic MEF panel that was used successfully to identify RAS oncogenic or wild-type allele-specific vulnerabilities. Furthermore, we identified sensitivity of oncogenic KRAS-expressing cells to CDK9 inhibitors, which warrants future studies of treating KRAS-driven cancers with CDK9 inhibitors.

Huntington's disease (HD) is the most common monogenic neurodegenerative disease and is fatal. CAG repeat expansions in mutant Huntingtin (mHTT) exon 1 encode for polyglutamine (polyQ) stretches and influence age of onset and disease severity, depending on their length. mHTT is more structured compared to wild-type (wt) HTT, resulting in a decreased N-terminal conformational flexibility. mHTT inflexibility may contribute to both gain of function toxicity, due to increased mHTT aggregation propensity, but also to loss of function phenotypes, due to decreased interactions with binding partners. High-throughput-screening techniques to identify mHTT flexibility states and potential flexibility modifying small molecules are currently lacking. Here, we propose a novel approach for identifying small molecules that restore mHTT's conformational flexibility in human patient fibroblasts. We have applied a well-established antibody-based time-resolved Förster resonance energy transfer (TR-FRET) immunoassay, which measures endogenous HTT flexibility using two validated HTT-specific antibodies, to a high-throughput screening platform. By performing a small-scale compound screen, we identified several small molecules that can partially rescue mHTT inflexibility, presumably by altering HTT post-translational modifications. Thus, we demonstrated that the HTT TR-FRET immunoassay can be miniaturized and applied to a compound screening workflow in patient cells. This automated assay can now be used in large screening campaigns to identify previously unknown HD drugs and drug targets.

ANS Collaboration is a growing Italian network of small and medium size telescopes performing spectroscopy (low and medium resolution single dispersion, and Echelle high resolution modes) and UBV RCIC CCD photometry of symbiotic stars and novae mainly, but with interest also on other types of objects like optical transients, eclipsing binaries, X-ray source counterparts and on-call follow-up observations of selected targets from some surveys like IPHAS or RAVE. In the present form ANS started operations in 2005, and at the time of writing has logged on symbiotic stars 14602 photometric runs and a rich ensemble of low and high resolution, absolutely fluxed spectra. the paper describes the internal organization, operation modes and procedures, and presents sample data and performance statistics.

IntroductionHereditary hemochromatosis (HH) is an autosomal recessive disorder caused by mutations in the HFE gene, which increase intestinal iron absorption. The prevalence of C282Y homozygosity, which causes the disorder, is 0.5% in Caucasian populations. The clinical manifestations are related to excess iron in the tissues, especially the liver, heart, pancreas, pituitary, and skin. They include fatigue, loss of libido or impotence in males, liver disease, skin pigmentation, diabetes mellitus, cardiac enlargement—with or without heart failure, and conduction defects. The classic triad of cirrhosis, diabetes mellitus, and skin pigmentation (“bronze diabetes”) results from a combination of iron deposits and melanin. It occurs late in the disease, when the total body iron content is more than five times the normal value, about 20 grams. Left untreated, approximately half of all patients with HH eventually develop arthralgia or arthropathy. Chondrocalcinosis, chronic pseudo-osteoarthritis, and osteoporosis are the major rheumatic manifestations of HH. The cause of the arthropathy is still unknown. Iron deposits within joints may trigger a number of pathologic events, such as free radical generation and crystal deposition, which stimulate immune complex formation and inflammation.Materials and methodsWe describe the case of a 48-year-old male suffering from chronic bilateral ankle pain.ResultsThe work-up revealed osteonecrosis of ankle. The patient also presented high plasma ferritin levels and homozygosity for the C282Y mutation. Other than HH, which was confirmed by liver biopsy, the patient had no other risk factors for osteonecrosis.DiscussionHH represents a rare cause of osteonecrosis, and there are no prior reports of aseptic osteonecrosis of the ankle in a patient with this disease. The pathogenetic mechanism remains unknown.

Background: Chronic dry cough is a debilitating symptom often refractory to standard antitussive therapy. It may result from increased sensitivity of the cough reflex. Baclofen, an agonist of gamma-aminobutyric acid (GABA), has been shown, in animals, to have antitussive activity via a central mechanism. In normal subjects baclofen has been revealed ability to inhibit capsaicininduced cough and cough due to angiotensin-converting enzyme (ACE) inhibitors. In addition, chronic therapy with baclofen has been shown to reduce cough reflex sensitivity in subjects with cervical spinal cord injury. Clinical cases: We describe two patients with chronic refractory cough who obtained symptomatic improvement after oral baclofen administration. The antitussive effect of baclofen, usually used for treatment of spasticity associated with multiple sclerosis and spinal cord lesions, can be explained by central inhibition, but may also involve peripheral inhibitory mechanisms.

Background and Objectives Bone lesions in multiple myeloma (MM) have been traditionally detected by whole body X-ray (WBXR) survey although magnetic resonance imaging (MRI) has become the gold standard for detecting MM involvement of the spine and pelvis. The aim of this study was to compare a new technique, positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) integrated with computed tomography (18F-FDG PET-CT), with MRI and WBXR for baseline assessment of bone disease in MM.Design and Methods We prospectively compared 18F-FDG PET-CT, MRI of the spine-pelvis and WBXR for baseline assessment of bone disease in a series of 46 patients with newly diagnosed MM. In 23 patients who received up front autologous transplantation, we also compared post-treatment PET-CT scans with MR images of the spine and pelvis.Results Overall, PET-CT was superior to planar radiographs in 46% of patients, including 19% with negative WBXR. In 30% of patients, PET-CT scans of the spine and pelvis failed to show abnormal findings in areas in which MRI revealed an abnormal pattern of bone marrow involvement, more frequently of diffuse type. In contrast, in 35% of patients PET-CT enabled the detection of myelomatous lesions in areas which were out of the field of view of MRI. By combining MRI of the spine-pelvis and 18F-FDG PET-CT, the ability to detect sites of active MM, both medullary and extramedullary, was as high as 92%. Following transplantation, 15 patients had negative PET-CT scans (including 13 with a very good partial response or at least near complete response), but only 8 had normal MRI.Interpretation and Conclusions MRI of the spine and pelvis still remains the gold standard imaging technique for the detection of bone marrow involvement in MM. 18F-FDG PET-CT provides additional and valuable information for the assessment of myeloma bone disease in areas not covered by MRI.