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Novel anticancer treatments target the pH regulating system that plays a major role in tumor progression by creating an acidic microenvironment, although few studies have addressed their effect on tumor acidosis. In this study, we investigated in vivo several proton pump inhibitors (PPIs) targeting NHE-1 (Amiloride and Cariporide) and V-ATPase (Esomeprazole and Lansoprazole) proton transporters in the DU145 androgen-insensitive human prostate cancer model. In cellulo results showed that DU145 are sensitive, with decreasing efficacy, to Amiloride, Esomeprazole and Lansoprazole, with marked cell toxicity both in normoxia and in hypoxia, with almost any change in pH. In vivo studies were performed upon administration of Esomeprazole to assess both the acute and chronic effects, and Iopamidol-based tumor pH imaging was performed to evaluate tumor acidosis. Although statistically significant tumor pH changes were observed a few hours after Esomeprazole administration in both the acute study and up to one week of treatment in the chronic study, longer treatment resulted in a lack of changes in tumor acidosis, which was associated to similar tumor growth curves between treated and control groups in both the subcutaneous and orthotopic models. Overall, this study highlights MRI-CEST tumor pH imaging as a valid approach to monitoring treatment response to PPIs. [ABSTRACT FROM AUTHOR]

Lymphomas are heterogeneous diseases, and the term includes a number of histological subtypes that are characterized by different clinical behavior and molecular phenotypes. Valuable information on the presence of lymphoma cell-derived extracellular vesicles (LCEVs) in the bloodstream of patients suffering from this hematological cancer has recently been provided. In particular, it has been reported that the number and phenotype of LCEVs can both change as the disease progresses, as well as after treatment. Moreover, the role that LCEVs play in driving tumor immune escape has been reported. This makes LCEVs potential novel clinical tools for diagnosis, disease progression, and chemoresistance. LCEVs express surface markers and convey specific molecules in accordance with their cell of origin, which can be used as targets and thus lead to the development of specific therapeutics. This may be particularly relevant since circulating LCEVs are known to save lymphoma cells from anti-cluster of differentiation (CD)20-induced complement-dependent cytotoxicity. Therefore, effort should be directed toward investigating the feasibility of using LCEVs as predictive biomarkers of disease progression and/or response to treatment that can be translated to clinical use. The use of liquid biopsies in combination with serum EV quantification and cargo analysis have been also considered as potential approaches that can be pursued in the future. Upcoming research will also focus on the identification of specific molecular targets in order to generate vaccines and/or antibodies against LCEVs. Finally, the removal of circulating LCEVs has been proposed as a simple and non-invasive treatment approach. We herein provide an overview of the role of LCEVs in lymphoma diagnosis, immune tolerance, and drug resistance. In addition, alternative protocols that utilize LCEVs as therapeutic targets are discussed. [ABSTRACT FROM AUTHOR]

According to the neurotrophic hypothesis, the development of pancreatic innervation by the nervous system would be dependent on the supply of trophic factors produced by the neuronal targets. Nerve growth factor (NGF) is important in the development and survival of sympathetic neurons. It has been demonstrated that in the absence of this neurotrophin, the extent of sympathetic pancreatic innervation is greatly reduced. We have demonstrated that adult pancreatic beta cells synthesize and secrete NGF and it has been shown that NGF mRNA is expressed in the gland during pancreatic development, however the cell source of the factor was not identified. To explore the possible participation of NGF in sympathetic innervation of pancreatic islets, we analyzed tirosine hydroxilase (TH) immunostaining and NGF mRNA by RT-PCR in different developmental stages (fetal F19, posnatal PO and P20) in rat islets. As previously observed, adult rodent islets are rounded, with alpha cells located in the periphery and beta cells in the core; however, this morphology is seldom observed in F19 pancreases, at P0 only some typical islets are observed, whereas at P20 most of the islets are similar to the adult. In F19, TH+ fibers are located close to the immature islets, at P0 in the surface of the islets, whereas at P20 fibers are located in the islets, mainly in the periphery, in the alpha cells neighborhood. In the adults, TH+ fibers were observed distributed inside the islets, mostly in the beta cell area. Interestingly, the relative area occupied by TH+ fibers increased in the islet along the different stages, reaching a peak in P20 and decreasing in the adult by 20%. NGF mRNA transcripts, as well as NGF immunofluorescence were found in the islet cells at all stages examined. NGF immunostaining was observed in 90% of isolated cells in F19, indicating that some non insulin-producing cells also express NGF.` Accordingly to this observation, beta, alpha cells and blood vessels were positive to pro-NGF in pancreatic tissue sections. These observations suggest that sympathetic innervation, as well as adult-like morphology increase from the fetal stage to P20 and from this stage to adulthood innervation is modeled. Fetal and posnatal islets synthesize NGF that could play an important role in the growth, guidance and survival of sympathetic fibers in the islets. This work was supported by DGAPA, UNAM. [ABSTRACT FROM AUTHOR]

Insulin secretion in mature beta-cells increases vigorously when extracellular glucose concentration rises. Glucose-stimulated insulin secretion depends on Ca(2+) influx through voltage-gated Ca(2+) channels. During fetal development, this structured response is not well established, and it is after birth that beta-cells acquire glucose sensitivity and a robust secretion. We compared some elements of glucose-induced insulin secretion coupling in beta-cells obtained from neonatal and adult rats and found that neonatal cells are functionally immature compared with adult cells. We observed that neonatal cells secrete less insulin and cannot sense changes in extracellular glucose concentrations. This could be partially explained because in neonates Ca(2+) current density and synthesis of mRNA alpha1 subunit Ca(2+) channel are lower than in adult cells. Interestingly, immunostaining for alpha1B, alpha1C, and alpha1D subunits in neonatal cells is similar in cytoplasm and plasma membrane, whereas it occurs predominantly in the plasma membrane in adult cells. We also observed that GLUT2 expression in adult beta-cells is mostly located in the membrane, whereas in neonatal cells glucose transporters are predominantly in the cytoplasm. This could explain, in part, the insensitivity to extracellular glucose in neonatal beta-cells. Understanding neonatal beta-cell physiology and maturation contributes toward a better comprehension of type 2 diabetes physiopathology, where alterations in beta-cells include diminished L-type Ca(2+) channels and GLUT2 expression that results in an insufficient insulin secretion.