Head and neck cancer patient journey's health literacy: a multidisciplinary team perspective. VOICE study.

PURPOSE: Health literacy is a current Public Health priority in Portugal. The participation of well-informed patients in their care and shared decision making are essential, especially in chronic aggressive and debilitating pathologies such as recurrent or metastatic (R/M) Head and Neck Squamous Cell Carcinoma (HNSCC). AIMS: This study aimed to characterize R/M HNSCC patients' and caregivers' information needs identified by healthcare professionals (HCPs). METHODS: Two online Focus Groups, one with only medical doctors and the other with other HCPs involved in the treatment of R/M HNSCC patients, were conducted, using a modified Metaplan, Lean or adapted PDCA methodology. The discussions were audio recorded in full and content analysis was performed using ATLAS.ti qualitative data analysis software. RESULTS: Topics addressed were diagnosis, treatment, quality of life, and global evaluation. In general, all experts agreed that only essential information should be cautiously given, according to patients' and caregivers' wishes. It was consensual that patients are given the necessary information to adhere to treatment. Two main barriers were identified: one barrier was associated with verbal communication due to the lack of health literacy of these patients, and the other barrier regarded healthcare access. It was also considered important to remind patients of the daily and social activities that they could and should maintain, as well as providing sufficient social resources and problem-solving training to caregivers. CONCLUSIONS: This qualitative study highlights the complexity of R/M HNSCC patients' care. Immediate availability of psychologists and psychiatrists should be implemented in all centers that treat HNSCC patients. The differences found between the physicians' Focus Group and other HCPs' Focus Group in some of the addressed topics emphasize the importance of a multidisciplinary and holistic approach, in a biomedical model integrated with a biopsychosocial model.

MiR-200c-based metabolic modulation in glioblastoma cells as a strategy to overcome tumor chemoresistance.

Glioblastoma (GB) is the most aggressive and common form of primary brain tumor characterized by fast proliferation, high invasion and resistance to current standard treatment. The average survival rate post-diagnosis is 14.6 months, despite the aggressive standard post-surgery radiotherapy concomitant with chemotherapy with temozolomide (TMZ). Currently, efforts are being endowed to develop new and more efficient therapeutic approaches capable to overcome chemoresistance, inhibit tumor progression and improve overall patient survival rate. Abnormal microRNA (miRNA) expression has been correlated with chemoresistance, proliferation and resistance to apoptosis, which result from their master regulatory role of gene expression. Altered cell metabolism, favoring glycolysis, was identified as an emerging cancer hallmark and has been described in GB, thus offering a new target for innovative GB therapies. In this work, we hypothesized that a gene therapy-based strategy consisting of the overexpression of a miRNA downregulated in GB and predicted to target crucial metabolic enzymes might promote a shift of GB cell metabolism, decreasing the glycolytic dependence of tumor cells and contributing to their sensitization to chemotherapy with TMZ. The increase of miR-200c levels in DBTRG cells resulted in downregulation of messenger RNA of enzymes involved in bioenergetics pathways and impaired cell metabolism and mobility. In addition, miR-200c overexpression prior to DBTRG cell exposure to TMZ resulted in cell cycle arrest. Overall, our results show that miR-200c overexpression could offer a way to overcome chemoresistance developed by GB cells in response to current standard chemotherapy, providing an improvement to current GB standard treatment, with benefit for patient outcome.

Differentiation of glioblastoma stem cells promoted by miR-128 or miR-302a overexpression enhances senescence-associated cytotoxicity of axitinib.

Despite the intense global efforts towards an effective treatment of glioblastoma (GB), current therapeutic options are unsatisfactory with a median survival time of 12-15 months after diagnosis, which has not improved significantly over more than a decade. The high tumoral heterogeneity confers resistance to therapies, which has hindered a successful clinical outcome, GB remaining among the deadliest cancers. A hallmark of GB is its high recurrence rate, which has been attributed to the presence of a small subpopulation of tumor cells called GB stem-like cells (GSC). In the present work, the efficacy of a multimodal strategy combining microRNA (miRNA) modulation with new generation multitargeted tyrosine kinase inhibitors (imatinib and axitinib) was investigated aiming at tackling this subpopulation of GB cells. MiR-128 and miR-302a were selected as attractive therapeutic candidates on the basis of previous findings reporting that reestablishment of their decreased expression levels in GSC resulted in cell differentiation, which could represent a possible strategy to sensitize GSC to chemotherapy. Our results show that overexpression of miR-128 or miR-302a induced GSC differentiation, which enhanced senescence mediated by axitinib treatment, thus further impairing GSC proliferation. We also provided evidence for the capacity of GSC to efficiently internalize functionalized stable nucleic acid lipid particles, previously developed and successfully applied in our laboratory to target GB. Taken together, our findings will be important in the future design of a GB-targeted multimodal miRNA-based gene therapy, combining overexpression of miR-128 or miR-302a with axitinib treatment, endowed with the ability to overcome drug resistance.

Downregulation of long non-protein coding RNA MVIH impairs glioblastoma cell proliferation and invasion through an miR-302a-dependent mechanism.

Glioblastoma (GB) is the most frequent and malignant type of brain tumor, for which no effective therapy exists. The high proliferative and invasive nature of GB, as well as its acquired resistance to chemotherapy, makes this type of cancer extremely lethal shortly after diagnosis. Long non-protein coding RNAs (lncRNA) are a class of regulatory RNAs whose levels can be dysregulated in the context of diseases, unbalancing several physiological processes. The lncRNA associated with microvascular invasion in hepatocellular carcinoma (lncRNA-MVIH), overexpressed in several cancers, was described to co-precipitate with phosphoglycerate kinase 1 (PGK1), preventing secretion of this enzyme to the extracellular environment and promoting cell migration and invasion. We hypothesized that, by silencing the expression of lncRNA-MVIH, the secretion of PGK1 would increase, reducing GB cell migration and invasion capabilities. We observed that lncRNA-MVIH silencing in human GB cells significantly decreased glycolysis, cell growth, migration, and invasion and sensitized GB cells to cediranib. However, no increase in extracellular PGK1 was observed as a consequence of lncRNA-MVIH silencing, and therefore, we investigated the possibility of a mechanism of miRNA sponge of lncRNA-MVIH being in place. We found that the levels of miR-302a loaded onto RISC increased in GB cells after lncRNA-MVIH silencing, with the consequent downregulation of several miR-302a molecular targets. Our findings suggest a new mechanism of action of lncRNA-MVIH as a sponge of miR-302a. We suggest that lncRNA-MVIH knockdown may be a promising strategy to address GB invasiveness and chemoresistance, holding potential towards its future application in a clinical context.

Multifocal Infantile Hepatic Hemangiomas Complicated by Consumptive Hypothyroidism: The Benefits of Early Diagnosis and Treatment.

Infantile hepatic hemangiomas (IHH) account for 12% of all childhood hepatic tumors. Most IHH are diagnosed within the first 6 months of life and involute spontaneously; however, some require medical treatment. The present report describes a case of multifocal IHH associated with subcutaneous and lingual hemangiomas, complicated by consumptive hypothyroidism and successfully managed with oral propranolol and thyroid replacement therapy, without documented adverse effects. Consumptive hypothyroidism is a rare complication of IHH, but suggestive of multifocal/diffuse subtypes. The authors intend to reinforce the importance of early referral to a Vascular Anomalies Center and treatment with propranolol in selected patients.

Neuroimaging of central nervous system tuberculosis.

A 20-month-old female, not immunized with Bacillus Calmette-Guérin (BCG) vaccine, was admitted due to a four-day history of fever and cough. In the past three months, she presented respiratory infections, weight loss and enlarged cervical lymph nodes. On day two of admission, she displayed drowsiness and positive Romberg's sign; cerebrospinal fluid (CSF) workout revealed 107/ul cells, low glucose and high protein levels. Ceftriaxone and acyclovir were initiated, and she was transferred to our tertiary hospital. Brain magnetic resonance imaging showed punctiform focal areas of restricted diffusion in left capsular lenticular region suggestive of vasculitis secondary to infection. Tuberculin skin test and interferon-gamma release assay were positive. She started tuberculostatic therapy, but two days later she presented tonic-clonic seizures and impaired consciousness. Cerebral computed tomography (CT) revealed tetrahydrocephalus (Figure 1), needing external ventricular derivation. She had a slow clinical improvement, requiring several neurosurgical interventions and developing a syndrome of inappropriate antidiuretic secretion alternating with cerebral salt wasting. Positive results for Mycobacterium tuberculosis were obtained by CSF culture and by polymerase chain reaction in CSF, bronchoalveolar lavage and gastric aspirate specimens. Repeated brain CT showed a large-vessel vasculitis with basal meningeal enhancement, typical of central nervous system (CNS) tuberculosis (Figure 2). She completed one month of corticosteroids and maintained antituberculosis treatment. At two years of age, she has spastic paraparesis and no language skills. Portugal had 1836 cases of tuberculosis (17.8 per 100000) in 2016 and was considered a low-incidence country; consequently, BCG vaccination is not universal (1). We present a severe case of CNS tuberculosis with intracranial hypertension, vasculitis and hyponatremia, associated with poorer outcomes (2). A high index of suspicion allowed prompt start of antituberculosis treatment. Diagnosis was corroborated by microbiological positivity and a typical triad in neuroimaging (hydrocephalus, vasculitis and basal meningeal enhancement) (3), which we wish to emphasize.

Stearoyl CoA Desaturase-1 Silencing in Glioblastoma Cells: Phospholipid Remodeling and Cytotoxicity Enhanced upon Autophagy Inhibition.

Modulation of lipid metabolism is a well-established cancer hallmark, and SCD1 has been recognized as a key enzyme in promoting cancer cell growth, including in glioblastoma (GBM), the deadliest brain tumor and a paradigm of cancer resistance. The central goal of this work was to identify, by MS, the phospholipidome alterations resulting from the silencing of SCD1 in human GBM cells, in order to implement an innovative therapy to fight GBM cell resistance. With this purpose, RNAi technology was employed, and low serum-containing medium was used to mimic nutrient deficiency conditions, at which SCD1 is overexpressed. Besides the expected increase in the saturated to unsaturated fatty acid ratio in SCD1 silenced-GBM cells, a striking increase in polyunsaturated chains, particularly in phosphatidylethanolamine and cardiolipin species, was noticed and tentatively correlated with an increase in autophagy (evidenced by the increase in LC3BII/I ratio). The contribution of autophagy to mitigate the impact of SCD1 silencing on GBM cell viability and growth, whose modest inhibition could be correlated with the maintenance of energetically associated mitochondria, was evidenced by using autophagy inhibitors. In conclusion, SCD1 silencing could constitute an important tool to halt GBM resistance to the available treatments, especially when coupled with a mitochondria disrupter chemotherapeutic.

MiR-144 overexpression as a promising therapeutic strategy to overcome glioblastoma cell invasiveness and resistance to chemotherapy.

Glioblastoma (GB) is the most aggressive and common form of primary brain tumor, characterized by fast proliferation, high invasion, and resistance to current standard treatment. The average survival rate post-diagnosis is only of 14.6 months, despite the aggressive standard post-surgery treatment approaches of radiotherapy concomitant with chemotherapy with temozolomide. Altered cell metabolism has been identified as an emerging cancer hallmark, including in GB, thus offering a new target for cancer therapies. On the other hand, abnormal expression levels of miRNAs, key regulators of multiple molecular pathways, have been correlated with pathological manifestations of cancer, such as chemoresistance, proliferation, and resistance to apoptosis. In this work, we hypothesized that gene therapy based on modulation of a miRNA with aberrant expression in GB and predicted to target crucial metabolic enzymes might impair tumor cell metabolism. We found that the increase of miR-144 levels, shown to be downregulated in U87 and DBTRG human GB cell lines, as well as in GB tumor samples, promoted the downregulation of mRNA of enzymes involved in bioenergetic pathways, with consequent alterations in cell metabolism, impairment of migratory capacity, and sensitization of DBTRG cells to a chemotherapeutic drug, the dichloroacetate (DCA). Taken together, our findings provide evidence that the miR-144 plus DCA combined therapy holds promise to overcome GB-acquired chemoresistance, therefore deserving to be explored toward its potential application as a complementary therapeutic approach to the current treatment options for this type of brain tumor.

Glucosylceramide synthase silencing combined with the receptor tyrosine kinase inhibitor axitinib as a new multimodal strategy for glioblastoma.

A great deal of evidence revealing that lipid metabolism is drastically altered during tumorigenesis has been accumulated. In this work, glucosylceramide synthase (GCS) was targeted, using RNA interference technology (siRNAs), in U87 and DBTRG human glioblastoma (GBM) cells, as in both cell types GCS showed to be overexpressed with respect to normal human astrocytes. The efficacy of a combined therapy to tackle GBM, allying GCS silencing to the new generation chemotherapeutics sunitinib and axitinib, or to the alkylating drugs etoposide and temozolomide, is evaluated here for the first time. With this purpose, studies addressing GBM cell viability and proliferation, cell cycle and apoptosis were performed, which revealed that combination of GCS silencing with axitinib treatment represents a promising therapeutic approach. The reduction of cell viability induced by this combined therapy is proposed to be mediated by excessive production of reactive oxygen species. This work, identifying GCS as a key molecular target to increase GBM susceptibility to a new generation chemotherapeutic, opens windows to the development of innovative strategies to halt GBM recurrence after surgical resection.

Lauroylated Histidine-Enriched S413-PV Peptide as an Efficient Gene Silencing Mediator in Cancer Cells.

PURPOSE: This study aimed to endow the cell-penetrating peptide (CPP) S413-PV with adequate features towards a safe and effective application in cancer gene therapy. METHODS: Peptide/siRNA complexes were prepared with two new derivatives of the CPP S413-PV, which combine a lauroyl group attached to the N- or C-terminus with a histidine-enrichment in the N-terminus of the S413-PV peptide, being named C12-H5-S413-PV and H5-S413-PV-C12, respectively. Physicochemical characterization of siRNA complexes was performed and their cytotoxicity and efficiency to mediate siRNA delivery and gene silencing in cancer cells were assessed in the absence and presence of serum. RESULTS: Peptide/siRNA complexes prepared with the C12-H5-S413-PV derivative showed a nanoscale (ca. 100 nm) particle size, as revealed by TEM, and efficiently mediated gene silencing (37%) in human U87 glioblastoma cells in the presence of 30% serum. In addition, the new C12-H5-S413-PV-based siRNA delivery system efficiently downregulated stearoyl-CoA desaturase-1, a key-enzyme of lipid metabolism overexpressed in cancer, which resulted in a significant decrease in the viability of U87 cells. Importantly, these complexes were able to spare healthy human astrocytes. CONCLUSIONS: These encouraging results pave the way for a potential application of the C12-H5-S413-PV peptide as a promising tool in cancer gene therapy.

High-throughput screening uncovers miRNAs enhancing glioblastoma cell susceptibility to tyrosine kinase inhibitors.

Glioblastoma (GBM) is a deadly and therapy resistant malignant brain tumour, characterized by an aggressive and diffuse growth pattern, which prevents complete surgical resection. Despite advances in the identification of genomic and molecular alterations that fuel the tumour, average patient survival post-diagnosis remains very low (∼14.6-months). In addition to being highly heterogeneous, GBM tumour cells exhibit high adaptive capacity to targeted molecular therapies owing to an established network of signalling cascades with functional redundancy, which provides them with robust compensatory survival mechanisms. Here, we investigated whether a multimodal strategy combining multitargeted tyrosine kinase inhibitors (MTKIs) and microRNA (miRNA) modulation could overcome the signalling pathway redundancy in GBM and, hence, promote tumour cell death. By performing a high-throughput screening, we identified a myriad of miRNAs, including those belonging to the miR-302-3p/372-3p/373-3p/520-3p family, which coordinately act with the MTKI sunitinib to decrease GBM cell viability. Two members of this family, hsa-miRNA-302a-3p and hsa-miRNA-520 b, were found to modulate the expression of receptor tyrosine kinase mediators (including AKT1, PIK3CA and SOS1) in U87 and DBTRG human GBM cells. Importantly, administration of mimics of these miRNAs with sunitinib or axitinib resulted in decreased tumour cell proliferation and enhanced cell death, whereas no significant effect was observed when coupling miRNA modulation with temozolomide, the first-line drug for GBM therapy. Overall, our results provide evidence that combining the 'horizontal' inhibition of signalling pathways promoted by MTKIs with the 'vertical' inhibition of the downstream signalling cascade promoted by hsa-miR-302a-3p and hsa-miR-520 b constitutes a promising approach towards GBM treatment.

Handgrip Dynamometry and Patient-Generated Subjective Global Assessment in Patients with Nonresectable Lung Cancer.

INTRODUCTION: Undernutrition is frequently associated with advanced lung cancer. Accurate nutritional assessment tools are important to provide the proper nutritional therapy. Handgrip dynamometry has already been used in these patients, and the findings suggest that it is a good indicator of nutritional status. AIMS: The aim of this study was to evaluate the association between nutritional status and handgrip strength (HGS) in patients with nonresectable lung cancer. METHODS: Cross-sectional study involving thirty-seven subjects with nonresectable lung cancer. Nutritional status was obtained using Patient Generated Subjective Global Assessment (PG-SGA), and muscle function was evaluated by HGS using a Jamar® handgrip dynamometer on the nondominant hand. The results of both methods were compared and correlated. RESULTS: According to PG-SGA, 73% (n = 27) of the patients were moderately undernourished, and 8% (n = 3) were severely undernourished. In total, 81% (n = 30) were undernourished. HGS was below the 50th percentile in 57% of the patients (n = 21). We found a significant association between nutritional status according to PG-SGA and HGS (P = 0.026, CI = 95%). CONCLUSIONS: Handgrip dynamometry can be a useful tool to evaluate the functional and nutritional status. It can be included in lung cancer patients evaluation, along with other nutritional assessment tools.

Gemini surfactants mediate efficient mitochondrial gene delivery and expression.

Gene delivery targeting mitochondria has the potential to transform the therapeutic landscape of mitochondrial genetic diseases. Taking advantage of the nonuniversal genetic code used by mitochondria, a plasmid DNA construct able to be specifically expressed in these organelles was designed by including a codon, which codes for an amino acid only if read by the mitochondrial ribosomes. In the present work, gemini surfactants were shown to successfully deliver plasmid DNA to mitochondria. Gemini surfactant-based DNA complexes were taken up by cells through a variety of routes, including endocytic pathways, and showed propensity for inducing membrane destabilization under acidic conditions, thus facilitating cytoplasmic release of DNA. Furthermore, the complexes interacted extensively with lipid membrane models mimicking the composition of the mitochondrial membrane, which predicts a favored interaction of the complexes with mitochondria in the intracellular environment. This work unravels new possibilities for gene therapy toward mitochondrial diseases.

A biophysical approach to menadione membrane interactions: relevance for menadione-induced mitochondria dysfunction and related deleterious/therapeutic effects.

Menadione (MEN), a polycyclic aromatic ketone, was shown to promote cell injury by imposing massive oxidative stress and has been proposed as a promising chemotherapeutic agent for the treatment of cancer diseases. The mechanisms underlying MEN-induced mitochondrial dysfunction and cell death are not yet fully understood. In this work, a systematic study was performed to unveil the effects of MEN on membrane lipid organization, using models mimicking mitochondrial membranes and native mitochondrial membranes. MEN was found to readily incorporate in membrane systems composed of a single phospholipid (phosphatidylcholine) or the lipids dioleoylphosphatidylcholine, dioleoylphosphatidylethanolamine and tetraoleoylcardiolipin at 1:1:1 molar ratio, as well as in mitochondrial membranes. Increased permeability in both membrane models, monitored by calcein release, seemed to correlate with the extent of MEN incorporation into membranes. MEN perturbed the physical properties of vesicles composed of dipalmitoylphosphatidylcholine or dipalmitoylphosphatidylethanolamine plus tetraoleoylcardiolipin (at 7:3 molar ratio), as reflected by the downshift of the lipid phase transition temperature and the emergence of a new transition peak in the mixed lipid system, detected by DSC. (31)P NMR studies revealed that MEN favored the formation of non-lamellar structures. Also, quenching studies with the fluorescent probes DPH and TMA-DPH showed that MEN distributed across the bilayer thickness in both model and native mitochondrial membranes. MEN's ability to promote alterations of membrane lipid organization was related with its reported mitochondrial toxicity and promotion of apoptosis, predictably involved in its anti-carcinogenic activity.

Application of thermoresponsive PNIPAAM-b-PAMPTMA diblock copolymers in siRNA delivery.

Gene knockdown has emerged as an important tool for cancer gene therapy as well as for viral infections and dominantly inherited genetic disorders. The generation of suitable siRNA delivery systems poses some challenges, namely, to avoid nuclease degradation, to surpass the cytoplasmic membrane, and to release the nucleic acids into the cytosol. Aiming at evaluating the ability of thermoresponsive block copolymers formed by units of N-isopropylacrylamide and of (3-acrylamidopropyl)trimethylammonium chloride to efficiently deliver siRNAs, an extensive study was performed with four different copolymers using a human fibrosarcoma cell line as cell model. The silencing ability and cytotoxicity of the generated copolymer-based siRNA delivery systems were found to be dependent on the cloud point of the polymer, which corresponds to the transition temperature at which the aggregation or precipitation of the polymer molecules becomes thermodynamically more favorable than their solubilization. In the present study, a system capable of delivering siRNAs efficiently, specifically and without presenting relevant cytotoxicity, even in the presence of serum, was developed. Confocal fluorescence experiments showed that the ability of the generated systems to silence the target gene is related to some extent to nucleic acid internalization, being also dependent on polymer/siRNA dissociation at 37 °C. Thus, a delicate balance between nucleic acid internalization and intracellular release must be met in order to reach an ideal knockdown efficiency. The special features and potential for manipulation of the N-isopropylacrylamide-based copolymers make them suitable materials for the design and synthesis of new and promising siRNA delivery systems.

The Role of Steroids in the Preservation of Hearing and Vestibular Function in Cochlear Implantation.

OBJECTIVE: Cochlear implant surgery is guided by principles of atraumatic insertion as to protect the inner ear. Previous studies suggest the potential benefit of steroids in patients undergoing cochlear implantation (CI), although the optimal route of administration has yet to be determined. We aim to systematically review the human studies of hearing and vestibular function preservation in patients undergoing CI receiving perioperative steroids and to discuss their role. DATA SOURCES: Search performed in PubMed, EMBASE, and CENTRAL databases in December 2023. REVIEW METHODS: Studies comparing several methods of steroid delivery and conventional management for patients undergoing CI were identified. Primary outcomes included hearing and vestibular function preservation. Secondary outcomes included reported adverse events, routes of steroid administration, and the presence of a control group without steroid administration. RESULTS: A total of 15 studies (N = 659) met inclusion criteria. Methodology, doses, route of steroid administration, and follow-up duration differed between most studies. Audiometric, vestibular, and hearing preservation (HP) results were inconsistent. In 12 studies, perioperative steroids were associated with either increased HP or vestibular function preservation. Only two studies reported adverse events related to oral corticosteroid therapy. CONCLUSIONS: There is a tendency for perioperative steroids to have a positive impact, at least in the short term, on hearing and vestibular function preservation in CI. Topical corticosteroid therapy appears to have a superior risk-benefit profile. There is a need for future carefully designed randomized controlled trials to determine the ideal route of steroid administration and its real impact in the long term. Laryngoscope, 134:3458-3465, 2024.

Real-World Healthcare Resource Use Associated with Recurrent or Metastatic Head and Neck Cancer Patients Care in Portugal-TRACE Study.

Recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) is a challenging disease, requiring personalized management by a multidisciplinary team. The aim of this retrospective multicentric study was to characterize real-world healthcare resource use and patient care for R/M HNSCC in Portugal during the first year after diagnosis. A total of 377 patients ineligible for curative treatment were included, mostly male (92.8%), aged 50-69 years (74.5%), with heavy alcohol (72.7%) or smoking habits (89.3%). Oropharynx (33.2%) and oral cavity (28.7%) were primary tumor locations, with lung metastases being the most common (61.4%). Eligible patients for systemic treatment with palliative intent (80.6%) received up to four treatment lines, with varied regimens. Platinum-based combination chemotherapy dominated first-line treatment (>70%), while single-agent chemotherapy and anti-PD1 immunotherapy were prevalent in later lines. Treatment approaches were uniform across disease stages and primary tumor locations but varied geographically. Treated patients received more multidisciplinary support than those who were ineligible. This study provides the first Portuguese real-world description of R/M HNSCC patient characteristics, treatment patterns, and supportive care during the year after diagnosis, highlighting population heterogeneity and aiming to improve patient management.

S4(13)-PV cell-penetrating peptide induces physical and morphological changes in membrane-mimetic lipid systems and cell membranes: implications for cell internalization.

The present work aims to gain insights into the role of peptide-lipid interactions in the mechanisms of cellular internalization and endosomal escape of the S4(13)-PV cell-penetrating peptide, which has been successfully used in our laboratory as a nucleic acid delivery system. A S4(13)-PV analogue, S4(13)-PVscr, displaying a scrambled amino acid sequence, deficient cell internalization and drug delivery inability, was used in this study for comparative purposes. Differential scanning calorimetry, fluorescence polarization and X-ray diffraction at small and wide angles techniques showed that both peptides interacted with anionic membranes composed of phosphatidylglycerol or a mixture of this lipid with phosphatidylethanolamine, increasing the lipid order, shifting the phase transition to higher temperatures and raising the correlation length between the bilayers. However, S4(13)-PVscr, in contrast to the wild-type peptide, did not promote lipid domain segregation and induced the formation of an inverted hexagonal lipid phase instead of a cubic phase in the lipid systems assayed. Electron microscopy showed that, as opposed to S4(13)-PVscr, the wild-type peptide induced the formation of a non-lamellar organization in membranes of HeLa cells. We concluded that lateral phase separation and destabilization of membrane lamellar structure without compromising membrane integrity are on the basis of the lipid-driven and receptor-independent mechanism of cell entry of S4(13)-PV peptide. Overall, our results can contribute to a better understanding of the role of peptide-lipid interactions in the mechanisms of cell-penetrating peptide membrane translocation, helping in the future design of more efficient cell-penetrating peptide-based drug delivery systems.

Leadership cycles, styles, and antecedent factors: the perspective of coaches and young soccer athletes from national Slovak leagues.

Introduction: Building positive relationships and interactions between coaches and athletes is critical to an athlete's success. The current study aimed to overview how coaches and their young athletes perceive three elements of the Leadership Efficacy Model (philosophy, practice, and criteria). The aim was examined with four goals of analysis: the perceptions of coaches and athletes about coaches' leadership philosophy, practice, and criteria (1); the differences between athletes' and coaches' perceptions of leadership cycles (2); the differences between athletes' and coaches' perceptions of leadership styles (3); and the differences between athletes' and coaches' perceptions of leadership antecedent factors (4). Methods: The study involved 304 athletes and 20 coaches competing in the youth national leagues U15, U16, U17, and U19. Two-source data collection was applied: coaches completed the questionnaires from their point of view, and so did athletes. The coaches were paired then with their athletes to compare the answers. Coaches fulfilled Leadership Cycles Questionnaire (LEQ), Multidimensional Scale of Leadership in Sport (MSLS), and Leadership Antecedent Factors Questionnaire (LAFQ). Athletes completed the same questionnaires as the coaches did and also fulfilled the Sport Performance Perception Questionnaire (SPPQ). Athletes' age and SPPQ served as control variables. Results: Both athletes (37.5%) and coaches (40%) perceived that the philosophy of the leadership efficacy model should be increased. Coaches evaluated their philosophy (F = 4.43; p = 0.036; η2 = 0.014), support in MSLS (F = 5.05; p = 0.025; η2 = 0.016) and active management in MSLS (F = 4.08; p = 0.044; η2 = 0.013) higher than their athletes. The athletes assessed the maturity of the team members (LAFQ dimension) (F = 13.98; p <0.001; η2 = 0.044), negative feedback in MSLS (F = 6.02; p = 0.015; η2 = 0.020), and passive management in MSLS (F = 4.95; p = 0.027; η2 = 0.016) higher than their coaches. Discussion: The tendency of coaches to have a more positive perception of their leadership behavior compared to their athletes represents the coach-athlete perception gap of leadership. Future research can examine the efficacy of congruent perceptions of leadership between athletes and coaches during the sports season and the impact produced by objective performance indicators.