Regulatory role of rpL3 in cell response to nucleolar stress induced by Act D in tumor cells lacking functional p53

Many chemotherapeutic drugs cause nucleolar stress and p53-independent pathways mediating the nucleolar stress response are emerging. Here, we demonstrate that ribosomal stress induced by Actinomycin D (Act D) is associated to the up-regulation of ribosomal protein L3 (rpL3) and its accumulation as ribosome-free form in lung and colon cancer cell lines devoid of p53. Free rpL3 regulates p21 expression at transcriptional and post-translational levels through a molecular mechanism involving extracellular-signal-regulated kinases1/2 (ERK1/2) and mouse double minute-2 homolog (MDM2). Our data reveal that rpL3 participates to cell response acting as a critical regulator of apoptosis and cell migration. It is noteworthy that silencing of rpL3 abolishes the cytotoxic effects of Act D suggesting that the loss of rpL3 makes chemotherapy drugs ineffective while rpL3 overexpression was associated to a strong increase of Act D-mediated inhibition of cell migration. Taking together our results show that the efficacy of Act D chemotherapy depends on rpL3 status revealing new specific targets involved in the molecular pathways activated by Act D in cancers lacking of p53. Hence, the development of treatments aimed at upregulating rpL3 may be beneficial for the treatment of these cancers

Circadian rhythms, physical activity and longevity

Human health implies complex mechanisms and involves diseases prevention aimed at ensuring a psycho-physical wellbeing homoeostasis. The search for longevity can be related to the slowdown in aging, and psycho-physical wellbeing is often related to the lifestyle, mainly to the human physical activity and nutrition. Circadian rhythms are processes that affect the behaviour, physiology and metabolism of mammals across cyclic periods of 24 hours. These rhythms are regulated by multiple physiological systems, whose key elements are the alternation between light and dark and between food consumption and periods of fasting. Therefore, during evolution, a constant adaptation to natural rhythms by humans has been established towards the surrounding environment determining periods of food consumption and periods of fasting coinciding with rest. Recent sociological surveys have shown that there is a slight increase in the number of people who devote themselves to a constant physical/sport activity, but this is an ephemeral percentage compared to the dramatic increase in the incidence of diseases related to aging such as obesity and diabetes, easily preventable with healthy lifestyles. Therefore, the connection between circadian rhythms, physical activity and lifestyles represents an important feature involved in human longevity. Here, a survive of the biological mechanisms, implied in this behaviour, is presented

Myostatin and plasticity of skeletal muscle tissue

Skeletal muscle is an extremely plastic tissue for its ability to respond to different stimuli such as physiological variation and external stress. Muscle hypertrophy involves an increase in muscle mass, changes in myofibril composition and adaptation of metabolic pathways. Plasticity of skeletal muscle in response to exercise training is also caused by proliferation and differentiation of the satellite muscle stem cells in response to various growth and differentiation factors. This process is mainly mediated by myokines secreted during skeletal muscle contraction. Myokines are proteins that act as hormones both locally in the muscle and/or in an endocrine manner in other organs, mainly liver, brain and adipose tissue. Myostatin, known as growth differentiation factor-8, a myokine member of transforming growth factor-b (TGF-b) superfamily, can act on muscle cells in an autocrine manner leading to inhibition of muscle myogenesis. Muscle myostatin expression and its plasma concentration are downregulated after acute and long-term physical exercise thus allowing muscle hypertrophy. In addition, myostatin is correlated to obesity and insulin resistance for its ability to affect energy metabolism and insulin-sensitivity in muscle cells, respectively. These findings reveal that myostatin may have potential therapeutic applications to treat muscle atrophy diseases in humans. Even in sports, drugs able to inhibit myostatin expression can lead athletes to increase their sport performance. Here, we present a brief overview of myostatin and its role in biological mechanisms involved in exercise-induced plasticity of skeletal muscle

Enhancement of 5-FU sensitivity by the proapoptotic rpL3 gene in p53 null colon cancer cells through combined polymer nanoparticles

Colon cancer is one of the leading causes of cancer-related death worldwide and the therapy with 5-fluorouracil (5-FU) is mainly limited due to resistance. Recently, we have demonstrated that nucleolar stress upon 5-FU treatment leads to the activation of ribosome-free rpL3 (L3) as proapoptotic factor. In this study, we analyzed L3 expression profile in colon cancer tissues and demonstrated that L3 mRNA amount decreased with malignant progression and the intensity of its expression was inversely related to tumor grade and Bcl-2/Bax ratio. With the aim to develop a combined therapy of 5-FU plus plasmid encoding L3 (pL3), we firstly assessed the potentiation of the cytotoxic effect of 5-FU on colon cancer cells by L3. Next, 10 μM 5-FU and 2 μg of pL3 were encapsulated in biocompatible nanoparticles (NPs) chemically conjugated with HA to achieve active tumor-targeting ability in CD44 overexpressing cancer cells. We showed the specific intracellular accumulation of NPs in cells and a sustained release for 5-FU and L3. Analysis of cytotoxicity and apoptotic induction potential of combined NPs clearly showed that the 5-FU plus L3 were more effective in inducing apoptosis than 5-FU or L3 alone. Furthermore, we show that the cancer-specific chemosensitizer effect of combined NPs may be dependent on L3 ability to affect 5-FU efflux by controlling P-gp (P-glycoprotein) expression. These results led us to propose a novel combined therapy with the use of 5-FU plus L3 in order to establish individualized therapy by examining L3 profiles in tumors to yield a better clinical outcomes

Detection of a coherent excitonic state in the layered semiconductor BiI3_{3}

The measurement and manipulation of the coherent dynamics of excitonic states constitute a forefront research challenge in semiconductor optics and in quantum coherence-based protocols for optoelectronic technologies. Layered semiconductors have emerged as an ideal platform for the study of exciton dynamics with accessible and technologically relevant energy and time scales. Here, we investigate the sub-picosecond exciton dynamics in a van-der-Waals semiconductor upon quasi-resonant excitation, and achieve to single out an incipient coherent excitonic state. Combining broadband transient reflectance spectroscopy and simulations based on many-body perturbation theory, we reveal a transient enhancement of the excitonic line intensity that originates from the photoinduced coherent polarization that is phase-locked with the interacting electromagnetic field. This finding allows us to define the spectral signature of a coherent excitonic state and to experimentally track the dynamical crossover from coherent to incoherent exciton, unlocking the prospective optical control of an exciton population on the intrinsic quantum-coherence timescale

Biotin-targeted Pluronic® P123/F127 mixed micelles delivering niclosamide: A repositioning strategy to treat drug-resistant lung cancer cells

With the aim to develop alternative therapeutic tools for the treatment of resistant cancers, here we propose targeted Pluronic1 P123/F127 mixed micelles (PMM) delivering niclosamide (NCL) as a repositioning strategy to treat multidrug resistant non-small lung cancer cell lines. To build multifunctional PMM for targeting and imaging, Pluronic1 F127 was conjugated with biotin, while Pluronic1 P123 was fluorescently tagged with rhodamine B, in both cases at one of the two hydroxyl end groups. This design intended to avoid any interference of rhodamine B on biotin exposition on PMM surface, which is a key fundamental for cell trafficking studies. Biotin-decorated PMM were internalized more efficiently than non-targeted PMM in A549 lung cancer cells, while very low internalization was found in NHI3T3 normal fibroblasts. Biotin-decorated PMM entrapped NCL with good efficiency, displayed sustained drug release in protein-rich media and improved cytotoxicity in A549 cells as compared to free NCL (P < 0.01). To go in depth into the actual therapeutic potential of NCL-loaded PMM, a cisplatin-resistant A549 lung cancer cell line (CPr-A549) was developed and its multidrug resistance tested against common chemotherapeutics. Free NCL was able to overcome chemoresistance showing cytotoxic effects in this cell line ascribable to nucleolar stress, which was associated to a significant increase of the ribosomal protein rpL3 and consequent up-regulation of p21. It is noteworthy that biotin- decorated PMM carrying NCL at low doses demonstrated a significantly higher cytotoxicity than free NCL in CPr-A549. These results point at NCL-based regimen with targeted PMM as a possible second-line chemotherapy for lung cancer showing cisplatin or multidrug resistance

Clinical Outcome after Adoptive Infusion of BPX-501 Cells (donor T cells transduced with iC9 suicide gene) in Children with Thalassemia Major (TM) Given Alfa/Beta T-Cell Depleted HLA-Haploidentical Stem Cell Transplantation (HSCT)

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Urothelium muscarinic activation phosphorylates CBS Ser227 via cGMP/PKG pathway causing human bladder relaxation through H 2 S production

The urothelium modulates detrusor activity through releasing factors whose nature has not been clearly defined. Here we have investigated the involvement of H2S as possible mediator released downstream following muscarinic (M) activation, by using human bladder and urothelial T24 cell line. Carbachol stimulation enhances H2S production and in turn cGMP in human urothelium or in T24 cells. This effect is reversed by cysthationine-β-synthase (CBS) inhibition. The blockade of M1 and M3 receptors reverses the increase in H2S production in human urothelium. In T24 cells, the blockade of M1 receptor significantly reduces carbachol-induced H2S production. In the functional studies, the urothelium removal from human bladder strips leads to an increase in carbachol-induced contraction that is mimicked by CBS inhibition. Instead, the CSE blockade does not significantly affect carbachol-induced contraction. The increase in H2S production and in turn of cGMP is driven by CBS-cGMP/PKG-dependent phosphorylation at Ser(227) following carbachol stimulation. The finding of the presence of this crosstalk between the cGMP/PKG and H2S pathway downstream to the M1/M3 receptor in the human urothelium further implies a key role for H2S in bladder physiopathology. Thus, the modulation of the H2S pathway can represent a feasible therapeutic target to develop drugs for bladder disorders

Identification and Functional Characterization of a Novel Mutation in theNKX2-1Gene: Comparison with the Data in the Literature

Background: NKX2-1 mutations have been described in several patients with primary congenital hypothyroidism, respiratory distress, and benign hereditary chorea, which are classical manifestations of the brain-thyroid-lung syndrome (BTLS). Methods: The NKX2-1 gene was sequenced in the members of a Brazilian family with clinical features of BTLS, and a novel monoallelic mutation was identified in the affected patients. We introduced the mutation in an expression vector for the functional characterization by transfection experiments using both thyroidal and lung-specific promoters. Results: The mutation is a deletion of a cytosine at position 834 (ref. sequence NM-003317) (c.493delC) that causes a frameshift with formation of an abnormal protein from amino acid 165 and a premature stop at position 196. The last amino acid of the nuclear localization signal, the whole homeodomain, and the carboxy-terminus of NKX2-1 are all missing in the mutant protein, which has a premature stop codon at position 196 (p.Arg165Glyfs*32). The p.Arg165Glyfs*32 mutant does not bind DNA, and it is unable to transactivate the thyroglobulin (Tg) and the surfactant protein-C (SP-C) promoters. Interestingly, a dose-dependent dominant negative effect of the p.Arg165Glyfs*32 was demonstrated only on the Tg promoter, but not on the SP-C promoter. This effect was also noticed when the mutation was tested in presence of PAX8 or cofactors that synergize with NKX2-1 (P300 and TAZ). The functional effect was also compared with the data present in the literature and demonstrated that, so far, it is very difficult to establish a specific correlation among NKX2-1 mutations, their functional consequence, and the clinical phenotype of affected patients, thus suggesting that the detailed mechanisms of transcriptional regulation still remain unclear. Conclusions: We describe a novel NKX2-1 mutation and demonstrate that haploinsufficiency may not be the only explanation for BTLS. Our results indicate that NKX2-1 activity is also finely regulated in a tissue-specific manner, and additional studies are required to better understand the complexities of genotype-phenotype correlations in the NKX2-1 deficiency syndrome