Antitumor effects of lactate transport inhibition on esophageal adenocarcinoma cells

As a consequence of altered glucose metabolism, cancer cell intake is increased, producing large amounts of lactate which is pumped out the cytosol by monocarboxylate transporters (MCTs). MCT 1 and MCT4 are frequently overexpressed in tumors, and recently, MCT inhibition has been reported to exert antineoplastic effects. In the present study, MCT1 and MCT4 levels were assessed in esophageal adenocarcinoma (EAC) cells and the effects of the MCT-1 selective inhibitor AZD3965, hypoxia, and a glucose overload were evaluated in vitro. Two EAC cell lines (OE33 and OACM5.1C) were treated with AZD3965 (10–100 nM) under different conditions (normoxia/hypoxia) and also different glucose concentrations, and parameters of cytotoxicity, oxidative stress, intracellular pH (pHi), and lactate levels were evaluated. MCT1 was present in both cell lines whereas MCT4 was expressed in OE33 cells and only in a small proportion of OACM5.1C cells. Glucose addition did not have any effect on apoptosis nor cell proliferation. AZD3965 increased apoptosis and reduced proliferation of OACM5.1C cells, effects which were abrogated when cells were growing in hypoxia. MCT1 inhibition increased intracellular lactate levels in all the cells evaluated, but this increase was higher in cells expressing only MCT1 and did not affect oxidative stress. AZD3965 induced a decrease in pHi of cells displaying low levels of MCT4 and also increased the sodium/hydrogen exchanger 1 (NHE-1) expression on these cells. These data provide in vitro evidence supporting the potential of MCT inhibitors as novel antineoplastic drugs for EAC and highlight the importance of achieving a complete MCT inhibition. (AU)

Mechanisms of regulating NIS transport to the cell membrane and redifferentiation therapy in thyroid cancer

Iodine is an essential constituent of thyroid hormone. Active iodide accumulation in the thyroid is mediated by the sodium iodide symporter (NIS), comprising the first step in thyroid hormone biosynthesis, which relies on the functional expression of NIS on the cell membrane. The retention of NIS expressed in differentiated thyroid cancer (DTC) cells allows further treatment with post-operative radioactive iodine (RAI) therapy. However, compared with normal thyroid tissue, differentiated thyroid tumors usually show a decrease in the active iodide conveyance and NIS is generally retained within the cells, indicating that posttranslational protein transfer to the plasma membrane is abnormal. In recent years, through in vitro studies and studies of patients with DTC, various methods have been tested to increase the transport rate of NIS to the cell membrane and increase the absorption of iodine. An in-depth understanding of the mechanism of NIS transport to the plasma membrane could lead to improvements in RAI therapy. Therefore, in this review, we discuss the current knowledge concerning the post-translational mechanisms that regulate NIS transport to the cell membrane and the current status of redifferentiation therapy for patients with RAI-refractory (RAIR)-DTC (AU)

Obesidad y diabetes mellitus tipo 2: también unidas en opciones terapéuticas / Obesity and type 2 diabetes: Also linked in therapeutic options

La prevalencia de la obesidad se ha incrementado mundialmente en las últimas décadas. La obesidad se asocia a múltiples comorbilidades, como la diabetes tipo 2, que generan un gran impacto en la salud y en la economía. La pérdida de peso en este colectivo favorece el control glucémico, por lo que es uno objetivo a lograr. Los cambios en el estilo de vida son poco efectivos por sí solos, y en los últimos años se han desarrollado otras opciones terapéuticas como la cirugía bariátrica/metabólica, así como fármacos para la diabetes tipo 2 y fármacos para reducir peso en la obesidad. El objetivo de la revisión es la comparación de los resultados en reducción de peso y control glucémico de los distintos tipos de fármacos con los resultados de la cirugía bariátrica/metabólica en diabetes tipo 2

The prevalence of obesity has increased worldwide over the past decades. Obesity is associated with multiple comorbidities, such as type 2 diabetes, that generates a great impact on health and economy. Weight loss in these patients leads to glycemic control so it is a target to achieve. Lifestyle changes are not effective enough and recently other treatments have been developed such as bariatric/metabolic surgery, as well as drugs for type 2 diabetes and antiobesity drugs. The aim of this review is to compare the results in weight reduction and glycemic control of the different kinds of drugs with bariatric / metabolic surgery's results in type 2 diabetes

SLC14A1: a novel target for human urothelial cancer

Urinary bladder cancer is the second commonly diagnosed genitourinary malignancy. Previously, bio-molecular alterations have been observed within certain locations such as chromosome 9, retinoblastoma gene and fibroblast growth factor receptor-3. Solute carrier family 14 member 1 (SLC14A1) gene encodes the type-B urea transporter (UT-B) which facilitates the passive movement of urea across cell membrane, and has recently been related with human malignancies, especially for bladder cancer. Herein, we discussed the SLC14A1 gene and UT-B protein properties, aiming to elucidate the expression behavior of SLC14A1 in human bladder cancer. Furthermore, by reviewing some well-established theories regarding the carcinogenesis of bladder cancer, including several genome wide association researches, we have bridged the mechanisms of cancer development with the aberrant expression of SLC14A1. In conclusion, the altered expression of SLC14A1 gene in human urothelial cancer may implicate its significance as a novel target for research (AU)

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Dapagliflozina, novedoso antidiabético oral de futuro incierto / Dapagliflozin, a novel oral antidiabetic with an uncertain future

Objetivo: La diabetes mellitus tipo 2 (DM2) es uno de los principales problemas sociosanitarios a nivel mundial, para la que existen multitud de tratamientos. Recientemente, se ha aprobado el primer fármaco de una nueva familia de antidiabéticos orales (ADO): la dapagliflozina. Nuestro objetivo es revisar la evidencia científica disponible sobre la dapagliflozina, con el fin de analizar su eficacia, seguridad y coste y poder estimar su papel en la farmacoterapia actual de la DM2.Métodos: La eficacia y seguridad de la dapagliflozina se analizaron mediante una evaluación de la evidencia científica. El coste de los diferentes ADO se calculó en base a sus dosis diarias definidas (DDD) y al precio de venta del laboratorio. Resultados: Se identificaron 7 ensayos clínicos aleatorizados:2 en monoterapia (840 pacientes) y 5 en terapia combinada con otros antidiabéticos (3184 pacientes). En los 7 ensayos, la dapagliflozina redujo la concentración de HbA1c; en todos se comparó con placebo, salvo en un estudio en terapia combinada que se comparó frente a fármaco activo (glipizida). Entre los efectos adversos más frecuentes se detectaron infecciones genitourinarias e hipotensión, aunque se debe prestar especial atención al incremento del cancer vejiga. Junto con los inhibidores de la DPP-4, la dapagliflozina es uno de los ADO de mayor coste (coste anual de DDD=729,3 euros). Conclusiones: La dapagliflozina no aporta ventajas respecto a la farmacoterapia de la DM2 ya existente. Su falta de experiencia de uso, la ausencia de importantes beneficios clínicos y su elevado coste hacen necesario restringir su utilización

Objective: Diabetes mellitus type 2 (DM2) is one of the main sociosanitary problems; there are many treatments for it. Recently, it has been approved the first drug of a new family of oral hypoglycemic agents (OHA): dapagliflozin. We aimed to review the available scientific evidence on dapagliflozin, in order to analyze its effectiveness, safety and cost and to estimate its role in the current pharmacotherapy of DM2.Methods: Effectiveness and safety of dapagliflozin were analyzed by an evaluation of the scientific evidence. The cost of different OHA was calculated based on the defined dailydose (DDD) and their ex-factory prices. Results: Seven randomized clinical trials were identified: 2monotherapy (840 patients) and 5 in combination with other hypoglycemic agents (3184 patients). In the seven trials, dapagliflozin reduced HbA1c; all were compared with placebo, unless in a trial of combination therapy in which was compared with an active drug (glipizide). The most common side effects were genitourinary infections and hypotension, although it should be taken into consideration the increase of the bladder cancer. Besides the DPP-4 inhibitors, dapagliflozin is one of the OHA more expensive (annual cost of DDD= 729.3 euros). Conclusions: Dapagliflozin does not provide advantages over pharmacotherapy for DM2. Its lack of experience of use, the absence of significant clinical benefits and its high cost make it necessary to restrict its use

Vitamin C transporters

Vitamin C is a wide spectrum antioxidant essential for humans, which are unableto synthesize the vitamin and must obtain it from dietary sources. There are two biologicallyimportant forms of vitamin C, the reduced form, ascorbic acid, and the oxidizedform, dehydroascorbic acid. Vitamin C exerts most of its biological functionsintracellularly and is acquired by cells with the participation of specific membranetransporters. This is a central issue because even in those species capable of synthesizingvitamin C, synthesis is restricted to the liver (and pancreas) from which is distributedto the organism. Most cells express two different transporter systems for vitaminC; a transporter system with absolute specificity for ascorbic acid and a secondsystem that shows absolute specificity for dehydroascorbic acid. The dehydroascorbicacid transporters are members of the GLUT family of facilitative glucose transporters,of which at least three isoforms, GLUT1, GLUT3 and GLUT4, are dehydroascorbicacid transporters. Ascorbic acid is transported by the SVCT family ofsodium-coupled transporters, with two isoforms molecularly cloned, the transportersSVCT1 y SVCT2, that show different functional properties and differentialcell and tissue expression. In humans, the maintenance of a low daily requirement ofvitamin C is attained through an efficient system for the recycling of the vitamininvolving the two families of vitamin C transporters (AU)

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Condrocalcinosis e hipomagnesemia en un paciente portador de una nueva mutación en el gen del cotransportador de ClNa sensible a tiazidas / Chondrocalcinosis and hypomagnesaemia in a patient with a new mutation in the gene of the thiazide-sensitive NA-Cl cotransporter

Se comunica la historia clínica de un paciente adulto que debutó en la adolescencia con episodios agudos de inflamación, monoarticulares, con afectación de grandes articulaciones de miembros superiores e inferiores, en ausencia de síntomas renales. El estudio radiológico mostró calcificaciones de los meniscos de ambas rodillas, de la sínfisis del pubis y de otras articulaciones. Al demostrarse la existencia de hipomagnesemia, se observó que tenía, además, hipopotasemia, hipocalciuria, incremento de la eliminación urinaria de magnesio, niveles de renina ligeramente elevados, defecto de dilución y una reducción moderada de la reabsorción de ClNa tubular distal renal, todo ello compatible con el diagnóstico de síndrome de Gitelman. La secuenciación de los exones y de las regiones intrónicas flanqueantes del gen SLC12A3, que codifica el cotransportador de ClNa sensible a tizaidas, mostró que el paciente es portador homocigótico de una nueva mutación en el intrón 7. La mutación consiste en el cambio de una G a una A en el sitio donador del "splicing" del RNA (AU)

Actualización de la cistinuria: aspectos clínicos, bioquímicos y genéticos / Cystinuria updating: clinical, biochemical and genetic aspects

La cistinuria es una enfermedad autosómica recesiva, con una incidencia estimada de un caso por cada 7000 nacidos vivos, que ocasiona una elevada excreción urinaria de cistina, lisina, arginina, y ornitina. Descrito ya en 1908, por sir Archibald Edward Garrod, como uno de los cuatro primeros errores del metabolismo conocidos, se caracteriza por un defecto en el transporte de cistina y de los aminoácidos dibásicos que afecta a su reabsorción en el túbulo renal y tracto gastrointestinal. Hasta la fecha, según hallazgos moleculares recientes, se han identificado dos genes como responsables de esta enfermedad: SLC3A1 y SLC7A9. Una correcta identificación fenotípica y/o genotípica de los pacientes cistinúricos permitirá una mejor profilaxis y terapia para esta patología. La cistinuria ocasiona urolitiasis recurrente (aproximadamente el 1-2 por ciento de los cálculos renales del adulto) debida a una deficiente solubilidad de la cistina a pH bajo. La calcinogénesis y sus complicaciones asociadas son las únicas manifestaciones clínicas de esta enfermedad. Las medidas profilácticas, basadas en una alta ingesta hídrica y la alcalinización de la orina con citrato potásico, en primera línea; y la utilización del arsenal farmacológico de derivados tiólicos, en segunda línea, se deberá extremar en aquellos pacientes (como los homocigotos tipo I) de alto riesgo litógeno. No obstante, para aproximadamente un 50 por ciento de los pacientes sometidos a control preventivo y que, a pesar de ello, desarrollarán litiasis recidivante, los procedimientos urológicos y quirúrgicos serán la única alternativa posible. En este artículo revisamos y actualizamos el conocimiento sobre los aspectos bioquímicos, genéticos, clínicos, diagnósticos, de prevención, tratamiento y pronósticos de esta, relativamente rara, enfermedad (AU)

Cystinuria is an autosomal recessive disorder with an estimated incidence of 1 case in 7000 live births that results in elevated urinary excretion of cystine and dibasic aminoacids: ornithine, lysine and arginine. Discussed by Sir Archibald Edward Garrod, in 1908, as one of the four first known inborn errors of metabolism, it is characterized by a defect in transport of cystine and dibasic aminoacids, that affects their reabsortion in both renal tubule and gastrointestinal tract. To date, according to the recent molecular findings, two genes have been identified as responsible for this disease: SLC3A1 and SLC7A9. A more accurate pheno/genotyping identification of cystinuric patients will allow to improve prophilaxis and therapy for this illness. Cystinuria only causes recurrent urolithiasis (about 1-2 % of renal calculi in adults) and its associated complications as clinical feature because of poor cystine solubility at low pH. An accurate control over prohylaxis (based on high water intake and potassium citrate treatment, on first line, and tiol-derivatives treatment, on second line) must be taken in patients -like homozygous type I- with high lithiasis risk. However, approximately one half of patients under prophylaxis control will develop recurrent lithiasis; in this case, only urology or surgical approaches would be possible. Updated knowledge about biochemical, genetic, clinical, diagnosis, prevention, treatment and prognosis aspects of this, relatively unusual, disease has been reviewed in this article (AU)

Alteraciones identificadas en la genética molecular de los trastornos tubulares que afectan al transporte de agua y electrolitos / Molecular basis of inherited tubular disorders affecting electrolytes and water transport

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