Low sodium and tolvaptan have opposite effects in human small cell lung cancer cells.

Abstract Purpose Hyponatraemia is frequently observed in cancer patients and can be due to the syndrome of inappropriate anti-diuresis (SIAD), related to ectopic vasopressin secretion, particularly in small cell lung cancer (SCLC). Hyponatraemia is associated with a worse outcome in cancer patients. The vasopressin receptor antagonist tolvaptan effectively corrects hyponatraemia secondary to SIAD and there is in vitro evidence that it has also an antiproliferative effect in cancer cells. The purpose of this study was i) to analyse the effect of low serum sodium concentrations ([Na+]) in SCLC cells and ii) to determine whether tolvaptan counteracts tumor progression. Methods We evaluated cell proliferation, cell cycle, apoptosis, oxidative stress, invasivity in low [Na+] as well as after exposure to tolvaptan. We also analysed the intracellular signalling pathways involved. Results In reduced [Na+] cell proliferation was significantly increased compared to normal [Na+] and cells were mostly distributed in the G2/M phase. Apoptosis appeared reduced. In addition, the ability to cross matrigel-coated membranes markedly increased. As observed in other cancer cell models, the expression of the heme-oxigenase-1 gene was increased. Finally, we found that in cells cultured in low [Na+] the RhoA/ROCK1/2 pathway, which is involved in the regulation of actin cytoskeleton, was activated. On the other hand, we found that tolvaptan effectively inhibited cell proliferation, anchorage-independent growth, invasivity and promoted apoptosis. Accordingly, the RhoA/ROCK-1/2 pathway was inhibited. Conclusions These findings demonstrate for the first time that low [Na+] favours tumor progression in SCLC cells, whereas tolvaptan effectively inhibits cell proliferation, survival and invasivity

The V2 receptor antagonist tolvaptan counteracts proliferation and invasivity in human cancer cells

PURPOSE: Hyponatremia, the most frequent electrolyte alteration in clinical practice, has been associated with a worse prognosis in cancer patients. On the other hand, a better outcome has been related to serum sodium normalization. In vitro studies have shown that low extracellular sodium promotes cancer cells proliferation and invasiveness. Tolvaptan, a selective vasopressin receptor type 2 (V(2)) antagonist, has been effectively used in the last decade for the treatment of hyponatremia secondary to the Syndrome of Inappropriate Antidiuresis. A few in vitro data suggested a direct role of tolvaptan in counteracting cancer progression, so far. The aim of this study was to evaluate the effect and the mechanism of action of tolvaptan in cell lines from different tumours [i.e. colon cancer (HCT-8), hepatocarcinoma (HepG2), neuroblastoma (SK-N-AS)]. METHODS AND RESULTS: First, we showed that these cell lines express the V(2) receptor. Tolvaptan significantly reduced cell proliferation with an IC(50) in the micromolar range. Accordingly, reduced levels of cAMP, of the catalytic α subunit of PKA, and a reduced pAKT/AKT ratio were observed. Tolvaptan effectively inhibited cell cycle progression, whereas it induced apoptotis. Furthermore, it reduced cell invasiveness. In particular, anchorage-independent growth and the activity of collagenases type IV were blunted in the three cell lines. Accordingly, tolvaptan counteracted the RhoA/ROCK1–2 pathway, which has a pivotal role in regulating cell movement. CONCLUSIONS: Overall, these findings indicate that tolvaptan effectively inhibits tumour progression in vitro. Further studies should clarify whether the V(2) receptor might be considered a possible target in anti-cancer strategies in the future

Liver haploinsufficiency of RuvBL1 causes hepatic insulin resistance and enhances hepatocellular carcinoma progression

RuvBL1 is an AAA+ ATPase whose expression in hepatocellular carcinoma (HCC) correlates with a poor prognosis. In vitro models suggest that targeting RuvBL1 could be an effective strategy against HCC. However, the role of RuvBL1 in the onset and progression of HCC remains unknown. To address this question, we developed a RuvBL1hep+/− mouse model and evaluated the outcome of DEN‐induced liver carcinogenesis up to 12 months of progression. We found that RuvBL1 haploinsufficiency initially delayed the onset of liver cancer, due to a reduced hepatocyte turnover in RuvBL1hep+/− mice. However, RuvBL1hep+/−mice eventually developed HCC nodules that, with aging, grew larger than in the control mice. Moreover, RuvBL1hep+/− mice developed hepatic insulin resistance and impaired glucose homeostasis. We could determine that RuvBL1 regulates insulin signaling through the Akt/mTOR pathway in liver physiology in vivo as well as in normal hepatocytic and HCC cells in vitro. Whole transcriptome analysis of mice livers confirmed the major role of RuvBL1 in the regulation of hepatic glucose metabolism. Finally, RuvBL1 expression was found significantly correlated to glucose metabolism and mTOR signaling by bioinformatic analysis of human HCC sample from the publicly available TGCA database. These data uncover a role of RuvBL1 at the intersection of liver metabolism, hepatocyte proliferation and HCC development, providing a molecular rationale for its overexpression in liver cancer

Aquaculture of Atlantic Bluefin Tuna (Thunnus thynnus L. 1758): increasing morphological knowledge on larvae and juveniles

Introduction In the last decade, different European research Institutes and private operators have collaborated in order to close the biological cycle of Atlantic bluefin tuna (ABFT) in captivity. Since 2002, two National projects (MIPAF 6C82 and 6C138) allowed the creation of a ABFT broodstock in cage in Italy, in order i) to improve the knowledge on anatomy (Martini et al., 2007), reproductive biology (Caprioli et al., 2007a; 2007b), and stress response in captivity (Ferrante et al, 2003; 2007; 2008), ii) to develop a method for estimating numbers and weights of tuna in cages by means of image analysis (Costa et al., 2009), and iii) to train qualified personnel for tuna farming needs. In 2007, the regional research project ALLOTUNA was carried out in the same facility and the first ABFT induced spawning in captivity was recorded in 2008 (De Metrio et al., 2010) at first, and then in 2009 and 2010. The availability of ABFT viable and fertilized eggs from induced spawning in captivity moved the research efforts to the next step (larval rearing), and the enlargement of knowledge on ABFT larvae and juveniles, which represents an essential step in order to establish a reliable production of farmed BFT fingerlings. Material and Methods The sampled larvae and juveniles outcame from eggs obtained from hormonal induction of broodstock (De Metrio et al., 2010) maintained in a floating cage at the ABFT fattening facility Mare Nostro (Lat: 38°43'36.65" N; Lon: 16° 4'39.79" E, Calabria, Italy), during the spawning seasons 2008-2010. Eggs were split and larval rearing carried out in three different private Italian hatcheries: Panittica Pugliese (Apulia), Aquacoltura Lampedusa S.r.l (Sicily) and Civita Ittica S.r.l. (Latium). Some wild ABFT juveniles were also collected at maximum 4 miles far from the fattening facility. The following analyses were performed on 1-90 days post hatch (dph) larvae and juveniles from controlled spawning: 1) morphometric analysis, in order to describe the ontogenetic changes in shape and the pattern of morphological integration between body regions (head, trunk and tail) during growth; 2) histological observations on in toto 1-48 dph fish, in order to investigate on larval and juveniles ontogenesis; 3) scanning electronic microscopy (SEM) observations, in order to investigate on ontogenesis and equipment of sense organs; 4) observations on in toto stained individuals, in order to investigate on skeleton ontogenesis and anomalies. Each analysis was performed also on available wild samples. Results Some ontogenetic pattern in reared individuals vary accordingly with age (dph) (i.e., number of mucous cells in esophagus; gastric gland number in the stomach), other with size (teeth eruption; number and developmental stage of taste buds), other from individual to individual, independently from age or size (skeletogenesis). The shape trajectory evidences saturation plateau starting from 35-38 dph, where shape remains quite constant. In some lot, the 100% of reared larvae show abortive swim bladder and a very high frequency of individuals with skeletal deformities was observed. The main ontogenetic processes seem to be similar to those reported in literature on other tuna species

Aquaculture of Atlantic Bluefin Tuna (Thunnus thynnus L. 1758): increasing morphological knowledge on larvae and juveniles

Introduction In the last decade, different European research Institutes and private operators have collaborated in order to close the biological cycle of Atlantic bluefin tuna (ABFT) in captivity. Since 2002, two National projects (MIPAF 6C82 and 6C138) allowed the creation of a ABFT broodstock in cage in Italy, in order i) to improve the knowledge on anatomy (Martini et al., 2007), reproductive biology (Caprioli et al., 2007a; 2007b), and stress response in captivity (Ferrante et al, 2003; 2007; 2008), ii) to develop a method for estimating numbers and weights of tuna in cages by means of image analysis (Costa et al., 2009), and iii) to train qualified personnel for tuna farming needs. In 2007, the regional research project ALLOTUNA was carried out in the same facility and the first ABFT induced spawning in captivity was recorded in 2008 (De Metrio et al., 2010) at first, and then in 2009 and 2010. The availability of ABFT viable and fertilized eggs from induced spawning in captivity moved the research efforts to the next step (larval rearing), and the enlargement of knowledge on ABFT larvae and juveniles, which represents an essential step in order to establish a reliable production of farmed BFT fingerlings. Material and Methods The sampled larvae and juveniles outcame from eggs obtained from hormonal induction of broodstock (De Metrio et al., 2010) maintained in a floating cage at the ABFT fattening facility Mare Nostro (Lat: 38°43'36.65" N; Lon: 16° 4'39.79" E, Calabria, Italy), during the spawning seasons 2008-2010. Eggs were split and larval rearing carried out in three different private Italian hatcheries: Panittica Pugliese (Apulia), Aquacoltura Lampedusa S.r.l (Sicily) and Civita Ittica S.r.l. (Latium). Some wild ABFT juveniles were also collected at maximum 4 miles far from the fattening facility. The following analyses were performed on 1-90 days post hatch (dph) larvae and juveniles from controlled spawning: 1) morphometric analysis, in order to describe the ontogenetic changes in shape and the pattern of morphological integration between body regions (head, trunk and tail) during growth; 2) histological observations on in toto 1-48 dph fish, in order to investigate on larval and juveniles ontogenesis; 3) scanning electronic microscopy (SEM) observations, in order to investigate on ontogenesis and equipment of sense organs; 4) observations on in toto stained individuals, in order to investigate on skeleton ontogenesis and anomalies. Each analysis was performed also on available wild samples. Results Some ontogenetic pattern in reared individuals vary accordingly with age (dph) (i.e., number of mucous cells in esophagus; gastric gland number in the stomach), other with size (teeth eruption; number and developmental stage of taste buds), other from individual to individual, independently from age or size (skeletogenesis). The shape trajectory evidences saturation plateau starting from 35-38 dph, where shape remains quite constant. In some lot, the 100% of reared larvae show abortive swim bladder and a very high frequency of individuals with skeletal deformities was observed. The main ontogenetic processes seem to be similar to those reported in literature on other tuna species