RESUMO
The ability of glioblastoma to disperse through the brain contributes to its lethality, and blocking this behavior has been an appealing therapeutic approach. Although a number of proinvasive signaling pathways are active in glioblastoma, many are redundant, so targeting one can be overcome by activating another. However, these pathways converge on nonredundant components of the cytoskeleton, and we have shown that inhibiting one of these-the myosin II family of cytoskeletal motors-blocks glioblastoma invasion even with simultaneous activation of multiple upstream promigratory pathways. Myosin IIA and IIB are the most prevalent isoforms of myosin II in glioblastoma, and we now show that codeleting these myosins markedly impairs tumorigenesis and significantly prolongs survival in a rodent model of this disease. However, while targeting just myosin IIA also impairs tumor invasion, it surprisingly increases tumor proliferation in a manner that depends on environmental mechanics. On soft surfaces myosin IIA deletion enhances ERK1/2 activity, while on stiff surfaces it enhances the activity of NFκB, not only in glioblastoma but in triple-negative breast carcinoma and normal keratinocytes as well. We conclude myosin IIA suppresses tumorigenesis in at least two ways that are modulated by the mechanics of the tumor and its stroma. Our results also suggest that inhibiting tumor invasion can enhance tumor proliferation and that effective therapy requires targeting cellular components that drive both proliferation and invasion simultaneously.
Assuntos
Carcinogênese/metabolismo , Citoesqueleto/metabolismo , Glioblastoma/metabolismo , Sistema de Sinalização das MAP Quinases , Proteínas de Neoplasias/metabolismo , Miosina não Muscular Tipo IIA/metabolismo , Animais , Carcinogênese/genética , Carcinogênese/patologia , Linhagem Celular Tumoral , Citoesqueleto/genética , Citoesqueleto/patologia , Glioblastoma/genética , Glioblastoma/patologia , Camundongos , Proteínas de Neoplasias/genética , Miosina não Muscular Tipo IIA/genéticaRESUMO
Mutations in the galactosidase ß 1 (GLB1) gene cause lysosomal ß-galactosidase (ß-Gal) deficiency and clinical onset of the neurodegenerative lysosomal storage disease, GM1 gangliosidosis. ß-Gal and neuraminidase 1 (NEU1) form a multienzyme complex in lysosomes along with the molecular chaperone, protective protein cathepsin A (PPCA). NEU1 is deficient in the neurodegenerative lysosomal storage disease sialidosis, and its targeting to and stability in lysosomes strictly depend on PPCA. In contrast, ß-Gal only partially depends on PPCA, prompting us to investigate the role that ß-Gal plays in the multienzyme complex. Here, we demonstrate that ß-Gal negatively regulates NEU1 levels in lysosomes by competitively displacing this labile sialidase from PPCA. Chronic cellular uptake of purified recombinant human ß-Gal (rhß-Gal) or chronic lentiviral-mediated GLB1 overexpression in GM1 gangliosidosis patient fibroblasts coincides with profound secondary NEU1 deficiency. A regimen of intermittent enzyme replacement therapy dosing with rhß-Gal, followed by enzyme withdrawal, is sufficient to augment ß-Gal activity levels in GM1 gangliosidosis patient fibroblasts without promoting NEU1 deficiency. In the absence of ß-Gal, NEU1 levels are elevated in the GM1 gangliosidosis mouse brain, which are restored to normal levels following weekly intracerebroventricular dosing with rhß-Gal. Collectively, our results highlight the need to carefully titrate the dose and dosing frequency of ß-Gal augmentation therapy for GM1 gangliosidosis. They further suggest that intermittent intracerebroventricular enzyme replacement therapy dosing with rhß-Gal is a tunable approach that can safely augment ß-Gal levels while maintaining NEU1 at physiological levels in the GM1 gangliosidosis brain.
Assuntos
Terapia de Reposição de Enzimas , Fibroblastos/enzimologia , Lisossomos/enzimologia , Mucolipidoses , beta-Galactosidase/uso terapêutico , Animais , Células CHO , Cricetulus , Humanos , Lisossomos/genética , Camundongos , Camundongos Mutantes , Mucolipidoses/tratamento farmacológico , Mucolipidoses/enzimologia , Mucolipidoses/genética , Neuraminidase/genética , Neuraminidase/metabolismoRESUMO
Autosomal recessive mutations in the galactosidase ß1 (GLB1) gene cause lysosomal ß-gal deficiency, resulting in accumulation of galactose-containing substrates and onset of the progressive and fatal neurodegenerative lysosomal storage disease, GM1 gangliosidosis. Here, an enzyme replacement therapy (ERT) approach in fibroblasts from GM1 gangliosidosis patients with recombinant human ß-gal (rhß-gal) produced in Chinese hamster ovary cells enabled direct and precise rhß-gal delivery to acidified lysosomes. A single, low dose (3 nm) of rhß-gal was sufficient for normalizing ß-gal activity and mediating substrate clearance for several weeks. We found that rhß-gal uptake by the fibroblasts is dose-dependent and saturable and can be competitively inhibited by mannose 6-phosphate, suggesting cation-independent, mannose 6-phosphate receptor-mediated endocytosis from the cell surface. A single intracerebroventricularly (ICV) administered dose of rhß-gal (100 µg) resulted in broad bilateral biodistribution of rhß-gal to critical regions of pathology in a mouse model of GM1 gangliosidosis. Weekly ICV dosing of rhß-gal for 8 weeks substantially reduced brain levels of ganglioside and oligosaccharide substrates and reversed well-established secondary neuropathology. Of note, unlike with the ERT approach, chronic lentivirus-mediated GLB1 overexpression in the GM1 gangliosidosis patient fibroblasts caused accumulation of a prelysosomal pool of ß-gal, resulting in activation of the unfolded protein response and endoplasmic reticulum stress. This outcome was unsurprising in light of our in vitro biophysical findings for rhß-gal, which include pH-dependent and concentration-dependent stability and dynamic self-association. Collectively, our results highlight that ICV-ERT is an effective therapeutic intervention for managing GM1 gangliosidosis potentially more safely than with gene therapy approaches.
Assuntos
Terapia de Reposição de Enzimas , Gangliosidose GM1/terapia , beta-Galactosidase/metabolismo , Animais , Gangliosidose GM1/metabolismo , Gangliosidose GM1/patologia , CamundongosRESUMO
Chronic knee pain is one of the most common complaints in primary care offices. Osteopathic family physicians Leonid Tafler and Samira Ovshaev have worked tirelessly for over 10 years to develop a revolutionary and unique technique for treating chronic knee pain. This technique is easy to learn and can be performed at any outpatient practice. This unique technique involves knee traction, which can be performed under anesthesia with one or two consecutive days of treatment, or it can be performed with the assistance of a supportive device in more than two therapy sessions without anesthesia. This new technique has the potential to become a first-line noninvasive technique for chronic knee pain that can go a long way in reducing the burden of debilitating knee pain for patients and their loved ones. This case report aims to describe a few cases of chronic knee pain successfully treated in the office-based surgical center by osteopathic physicians using this innovative technique. Throughout the last 10 years, patients have reported remarkable improvement in their knee pain following treatment with this technique, which has, in turn, significantly increased their quality of life.
RESUMO
Vertebral artery dissection (VAD) is a cause of brain stem stroke in the younger population and is commonly associated with trauma, sudden neck movement, or chiropractic manipulations. In this case, a 28-year-old male with a non-significant past medical history who recently started a CrossFit boot camp presented to the emergency department with right-sided neck pain, dysarthria, mild right gaze paresis, right dysmetria, and right facial droop with symptoms of Horner's syndrome. Imaging results revealed an age-indeterminate left lateral cerebellar infarct with right VAD. The goal of management is to prevent stroke, which is done with anticoagulation and potentially thrombolytic therapy if there are no contraindications. The patient received thrombolytic therapy and was treated with conservative management. The prognosis is good for patients who survive the initial dissection and are treated in this manner. It is important to obtain a thorough history of young and healthy patients who present with concerning neurologic symptoms so that precipitating activities are not missed.
RESUMO
PURPOSE: To study the nature of crowdfunding campaigns for common ophthalmologic procedures. METHODS: Cross sectional, retrospective study of campaigns on GoFundMe.com from January 1st, 2021 to July 31st, 2021. All domestic and international campaigns referring to cataract and intraocular lens placement or LASIK procedures, excluding those with non-ophthalmologic conditions or campaigns for multiple conditions. Descriptive analysis of campaigns including condition, country of origin of patient, total and median value raised, total and median value sought, age of the patient, funding goal met, insurance status when possible. Total and median funds raised and sought, international versus domestic campaigns, success rate for campaigns, percent of campaigns involving children, percent of campaigns mentioning insurance. RESULTS: 137 campaigns were identified, 67.9% (93/137) were for cataract and 32.1% (44/137) were for LASIK. 13.1% (18/137) of campaigns were international. 7.3% (10/137) campaigns were successful at reaching fing goals. Of successful campaigns, 70.0% (7/10) were for cataract and 30.0% (3/10) were for LASIK. Total value raised (in USD) was $131,763, where $106,593 was for cataract and $25,170 was for LASIK. The median value sought overall was $5,000, where the median sought for cataract procedures was $5,000 and the median for LASIK was $4,000. The median value raised was $395. 5.8% (8/137) of campaigns mentioned minors. 12.5% (1/8) of campaigns for children or minors successfully met funding goals compared to 7.0% (9/129) adult campaigns. The total funds raised for children or minors was $9,224 with a goal of $41,050. The total funds raised for adults was $122,539 out of a goal of $775,617. 14.6% (20/137) campaigns mentioned insurance coverage, of which 85% (17/20) were for cataract and 15.0% (3/20) were for LASIK. Premium lenses (toric, multifocal, etc.) were mentioned in 1.1% of cataract campaigns (1/93) as being cost prohibitive. CONCLUSIONS: Crowdfunding is ineffective as a means for patients to raise funds for ophthalmic procedures. The broad range of financial requests within campaigns indicates a large patient knowledge gap in cost for procedures.
Assuntos
Catarata , Ceratomileuse Assistida por Excimer Laser In Situ , Adulto , Criança , Estudos Transversais , Humanos , Estudos RetrospectivosRESUMO
Prioritizing genes for translation to therapeutics for common diseases has been challenging. Here, we propose an approach to identify drug targets with high probability of success by focusing on genes with both gain of function (GoF) and loss of function (LoF) mutations associated with opposing effects on phenotype (Bidirectional Effect Selected Targets, BEST). We find 98 BEST genes for a variety of indications. Drugs targeting those genes are 3.8-fold more likely to be approved than non-BEST genes. We focus on five genes (IGF1R, NPPC, NPR2, FGFR3, and SHOX) with evidence for bidirectional effects on stature. Rare protein-altering variants in those genes result in significantly increased risk for idiopathic short stature (ISS) (OR = 2.75, p = 3.99 × 10-8). Finally, using functional experiments, we demonstrate that adding an exogenous CNP analog (encoded by NPPC) rescues the phenotype, thus validating its potential as a therapeutic treatment for ISS. Our results show the value of looking for bidirectional effects to identify and validate drug targets.
Assuntos
Genes , Preparações Farmacêuticas , Descoberta de Drogas , Nanismo/genética , Estudos de Associação Genética , Humanos , Peptídeo Natriurético Tipo C/genética , Fenótipo , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Receptor IGF Tipo 1/genética , Receptores do Fator Natriurético Atrial/genética , Proteína de Homoeobox de Baixa Estatura/genéticaRESUMO
We report that atypical protein kinase Cι (PKCι) is an oncogenic driver of glioblastoma (GBM). Deletion or inhibition of PKCι significantly impairs tumor growth and prolongs survival in murine GBM models. GBM cells expressing elevated PKCι signaling are sensitive to PKCι inhibitors, whereas those expressing low PKCι signaling exhibit active SRC signaling and sensitivity to SRC inhibitors. Resistance to the PKCι inhibitor auranofin is associated with activated SRC signaling and response to a SRC inhibitor, whereas resistance to a SRC inhibitor is associated with activated PKCι signaling and sensitivity to auranofin. Interestingly, PKCι- and SRC-dependent cells often co-exist in individual GBM tumors, and treatment of GBM-bearing mice with combined auranofin and SRC inhibitor prolongs survival beyond either drug alone. Thus, we identify PKCι and SRC signaling as distinct therapeutic vulnerabilities that are directly translatable into an improved treatment for GBM.
Assuntos
Glioblastoma/genética , Glioblastoma/metabolismo , Isoenzimas/metabolismo , Proteína Quinase C/metabolismo , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Modelos Animais de Doenças , Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/genética , Glioblastoma/classificação , Humanos , Isoenzimas/genética , Camundongos , Oncogenes/genética , Proteína Quinase C/genética , Proteína Quinase C/fisiologia , Transdução de Sinais/fisiologiaRESUMO
Glioblastoma, the most lethal primary brain cancer, is extremely proliferative and invasive. Tumor cells at tumor/brain-interface often exist behind a functionally intact blood-brain barrier (BBB), and so are shielded from exposure to therapeutic drug concentrations. An ideal glioblastoma treatment needs to engage targets that drive proliferation as well as invasion, with brain penetrant therapies. One such target is the mitotic kinesin KIF11, which can be inhibited with ispinesib, a potent molecularly-targeted drug. Although, achieving durable brain exposures of ispinesib is critical for adequate tumor cell engagement during mitosis, when tumor cells are vulnerable, for efficacy. Our results demonstrate that the delivery of ispinesib is restricted by P-gp and Bcrp efflux at BBB. Thereby, ispinesib distribution is heterogeneous with concentrations substantially lower in invasive tumor rim (intact BBB) compared to glioblastoma core (disrupted BBB). We further find that elacridar-a P-gp and Bcrp inhibitor-improves brain accumulation of ispinesib, resulting in remarkably reduced tumor growth and extended survival in a rodent model of glioblastoma. Such observations show the benefits and feasibility of pairing a potentially ideal treatment with a compound that improves its brain accumulation, and supports use of this strategy in clinical exploration of cell cycle-targeting therapies in brain cancers.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Benzamidas/farmacologia , Proliferação de Células/efeitos dos fármacos , Cinesinas/antagonistas & inibidores , Proteínas de Neoplasias/genética , Quinazolinas/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Acridinas/química , Acridinas/farmacologia , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Cinesinas/genética , Camundongos , Terapia de Alvo Molecular , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Proteínas de Neoplasias/antagonistas & inibidores , Tetra-Hidroisoquinolinas/química , Tetra-Hidroisoquinolinas/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Invasion and proliferation are defining phenotypes of cancer, and in glioblastoma blocking one stimulates the other, implying that effective therapy must inhibit both, ideally through a single target that is also dispensable for normal tissue function. The molecular motor myosin 10 meets these criteria. Myosin 10 knockout mice can survive to adulthood, implying that normal cells can compensate for its loss; its deletion impairs invasion, slows proliferation, and prolongs survival in murine models of glioblastoma. Myosin 10 deletion also enhances tumor dependency on the DNA damage and the metabolic stress responses and induces synthetic lethality when combined with inhibitors of these processes. Our results thus demonstrate that targeting myosin 10 is active against glioblastoma by itself, synergizes with other clinically available therapeutics, may have acceptable side effects in normal tissues, and has potential as a heretofore unexplored therapeutic approach for this disease.
RESUMO
Sanfilippo syndrome type B (Sanfilippo B; Mucopolysaccharidosis type IIIB) occurs due to genetic deficiency of lysosomal alpha-N-acetylglucosaminidase (NAGLU) and subsequent lysosomal accumulation of heparan sulfate (HS), which coincides with devastating neurodegenerative disease. Because NAGLU expressed in Chinese hamster ovary cells is not mannose-6-phosphorylated, we developed an insulin-like growth factor 2 (IGF2)-tagged NAGLU molecule (BMN 250; tralesinidase alfa) that binds avidly to the IGF2 / cation-independent mannose 6-phosphate receptor (CI-MPR) for glycosylation independent lysosomal targeting. BMN 250 is currently being developed as an investigational enzyme replacement therapy for Sanfilippo B. Here we distinguish two cellular uptake mechanisms by which BMN 250 is targeted to lysosomes. In normal rodent-derived neurons and astrocytes, the majority of BMN250 uptake over 24 hours reaches saturation, which can be competitively inhibited with IGF2, suggestive of CI-MPR-mediated uptake. Kuptake, defined as the concentration of enzyme at half-maximal uptake, is 5 nM and 3 nM in neurons and astrocytes, with a maximal uptake capacity (Vmax) corresponding to 764 nmol/hr/mg and 5380 nmol/hr/mg, respectively. Similar to neurons and astrocytes, BMN 250 uptake in Sanfilippo B patient fibroblasts is predominantly CI-MPR-mediated, resulting in augmentation of NAGLU activity with doses of enzyme that fall well below the Kuptake (5 nM), which are sufficient to prevent HS accumulation. In contrast, uptake of the untagged recombinant human NAGLU (rhNAGLU) enzyme in neurons, astrocytes and fibroblasts is negligible at the same doses tested. In microglia, receptor-independent uptake, defined as enzyme uptake resistant to competition with excess IGF2, results in appreciable lysosomal delivery of BMN 250 and rhNAGLU (Vmax = 12,336 nmol/hr/mg and 5469 nmol/hr/mg, respectively). These results suggest that while receptor-independent mechanisms exist for lysosomal targeting of rhNAGLU in microglia, BMN 250, by its IGF2 tag moiety, confers increased CI-MPR-mediated lysosomal targeting to neurons and astrocytes, two additional critical cell types of Sanfilippo B disease pathogenesis.
Assuntos
Acetilglucosaminidase/metabolismo , Endocitose , Fator de Crescimento Insulin-Like II/uso terapêutico , Mucopolissacaridose III/tratamento farmacológico , Mucopolissacaridose III/patologia , Proteínas Recombinantes de Fusão/uso terapêutico , Acetilglucosaminidase/farmacocinética , Acetilglucosaminidase/uso terapêutico , Animais , Astrócitos/metabolismo , Axônios/metabolismo , Cátions , Fibroblastos/metabolismo , Heparitina Sulfato/metabolismo , Hipocampo/patologia , Humanos , Fator de Crescimento Insulin-Like II/farmacocinética , Lisossomos/enzimologia , Microglia/metabolismo , Ratos , Receptor IGF Tipo 2/metabolismo , Proteínas Recombinantes de Fusão/farmacocinéticaRESUMO
Sanfilippo syndrome type B, or mucopolysaccharidosis IIIB (MPS IIIB), is a rare autosomal recessive lysosomal storage disease caused by a deficiency of α-N-acetylglucosaminidase (NAGLU). Deficiency in NAGLU disrupts the lysosomal turnover of heparan sulfate (HS), which results in the abnormal accumulation of partially degraded HS in cells and tissues. BMN 250 (NAGLU-insulin-like growth factor 2 [IGF2]) is a recombinant fusion protein developed as an investigational enzyme replacement therapy for MPS IIIB. The IGF2 peptide on BMN 250 promotes enhanced targeting of the enzyme to lysosomes through its interaction with the mannose 6-phosphate receptor. The focus of these studies was to further characterize the ability of NAGLU-IGF2 to clear accumulated HS compared to unmodified NAGLU in primary cellular models of MPS IIIB. Here, we establish distinct primary cell models of MPS IIIB with HS accumulation. These cellular models revealed distinct NAGLU uptake characteristics that depend on the duration of exposure. We found that with sustained exposure, NAGLU uptake and HS clearance occurred independent of known lysosomal targeting signals. In contrast, under conditions of limited exposure duration, NAGLU-IGF2 was taken up more rapidly than the unmodified NAGLU into MPS IIIB primary fibroblasts, astrocytes, and cortical neurons, where it efficiently degraded accumulated HS. These studies illustrate the importance of using physiologically relevant conditions in the evaluation of enzyme replacement therapies in cellular models.