Modulation of PKM alternative splicing by PTBP1 promotes gemcitabine resistance in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and incurable disease. Poor prognosis is due to multiple reasons, including acquisition of resistance to gemcitabine, the first-line chemotherapeutic approach. Thus, there is a strong need for novel therapies, targeting more directly the molecular aberrations of this disease. We found that chronic exposure of PDAC cells to gemcitabine selected a subpopulation of cells that are drug-resistant (DR-PDAC cells). Importantly, alternative splicing (AS) of the pyruvate kinase gene (PKM) was differentially modulated in DR-PDAC cells, resulting in promotion of the cancer-related PKM2 isoform, whose high expression also correlated with shorter recurrence-free survival in PDAC patients. Switching PKM splicing by antisense oligonucleotides to favor the alternative PKM1 variant rescued sensitivity of DR-PDAC cells to gemcitabine and cisplatin, suggesting that PKM2 expression is required to withstand drug-induced genotoxic stress. Mechanistically, upregulation of the polypyrimidine-tract binding protein (PTBP1), a key modulator of PKM splicing, correlated with PKM2 expression in DR-PDAC cell lines. PTBP1 was recruited more efficiently to PKM pre-mRNA in DR- than in parental PDAC cells. Accordingly, knockdown of PTBP1 in DR-PDAC cells reduced its recruitment to the PKM pre-mRNA, promoted splicing of the PKM1 variant and abolished drug resistance. Thus, chronic exposure to gemcitabine leads to upregulation of PTBP1 and modulation of PKM AS in PDAC cells, conferring resistance to the drug. These findings point to PKM2 and PTBP1 as new potential therapeutic targets to improve response of PDAC to chemotherapy.Oncogene advance online publication, 3 August 2015; doi:10.1038/onc.2015.270

Innovation in practice: mobile phone technology in patient care

Mobile phones are becoming increasingly important in everyday life and now in healthcare. There has been a steady growth of information and communication technologies in health communication and technology is used progressively in telemedicine, wireless monitoring of health outcomes in disease and in the delivery of health interventions. Mobile phones are becoming an important method of encouraging better nurse-patient communication and will undoubtedly increase in application over coming years. This article presents recent developments and applications of mobile technology for health promotion and patient-monitoring in chronic disease

Sempervirine inhibits RNA polymerase I transcription independently from p53 in tumor cells

In the search of small molecules that can target MDM2/p53 pathway in testicular germ cell tumors (TGCTs), we identified sempervirine (2,3,4,13-tetrahydro-1H-benz[g]indolo[2,3-a]quinolizin-6-ium), an alkaloid of Gelsemium sempervirens, that has been previously proposed as an inhibitor of MDM2 that targets p53-wildtype (wt) tumor cells. We found that sempervirine not only affects cell growth of p53-wt cancer cells, but it is also active in p53-mutated and p53-null cells by triggering p53-dependent and independent pathways without affecting non-transformed cells. To understand which mechanism/s could be activated both in p53-wt and -null cells, we found that sempervirine induced nucleolar remodeling and nucleolar stress by reducing protein stability of RPA194, the catalytic subunit of RNA polymerase I, that led to rRNA synthesis inhibition and to MDM2 block. As shown for other cancer cell models, MDM2 inhibition by nucleolar stress downregulated E2F1 protein levels both in p53-wt and p53-null TGCT cells with the concomitant upregulation of unphosphorylated pRb. Finally, we show that sempervirine is able to enter the nucleus and accumulates within the nucleolus where it binds rRNA without causing DNA damage. Our results identify semperivirine as a novel rRNA synthesis inhibitor and indicate this drug as a non-genotoxic anticancer small molecule

Epidemiology and outcome of Clostridium difficile infections in patients hospitalized in Internal Medicine: findings from the nationwide FADOI-PRACTICE study.

BACKGROUND: Clostridium difficile (CD) is a leading cause of diarrhoea among hospitalized patients. The objective of this study was to evaluate the rate, the optimal diagnostic work-up, and outcome of CD infections (CDI) in Internal Medicine (IM) wards in Italy. METHODS: PRACTICE is an observational prospective study, involving 40 IM Units and evaluating all consecutive patients hospitalized during a 4-month period. CDI were defined in case of diarrhoea when both enzyme immunoassay for GDH, and test for A/B toxin were positive. Patients with CDI were followed-up for recurrences for 4 weeks after the end of therapy. RESULTS: Among the 10,780 patients observed, 103 (0.96 %) showed CDI, at admission or during hospitalization. A positive history for CD, antibiotics in the previous 4 weeks, recent hospitalization, female gender and age were significantly associated with CDI (multivariable analysis). In-hospital mortality was 16.5 % in CD group vs 6.7 % in No-CD group (p\u2009<\u20090.001), whereas median length of hospital stay was 16 (IQR\u2009=\u200913) vs 8 (IQR\u2009=\u20098) days (p\u2009<\u20090.001) among patients with or without CDI, respectively. Rate of CD recurrences was 14.6 %. As a post-hoc evaluation, 23 out of 34 GDH+/Tox- samples were toxin positive, when analysed by molecular method (a real-time PCR assay). The overall CD incidence rate was 5.3/10,000 patient-days. CONCLUSIONS: Our results confirm the severity of CDI in medical wards, showing high in-hospital mortality, prolonged hospitalization and frequent short-term recurrences. Further, our survey supports a 2-3 step algorithm for CD diagnosis: EIA for detecting GDH, A and B toxin, followed by a molecular method in case of toxin-negative samples

Monitoring symptoms at home: What methods would cancer patients be comfortable using?

PURPOSE: This study aimed to determine which methods of remote symptom assessment cancer outpatients would be comfortable using, including those involving information technology, and whether this varied with age and gender. METHODS: A questionnaire survey of 477 outpatients attending the Edinburgh Cancer Centre in Edinburgh, UK. RESULTS: Most patients reported that they would not feel comfortable using methods involving technology such as a secure website, email, mobile phone text message, or a computer voice on the telephone but that they would be more comfortable using more traditional methods such as a paper questionnaire, speaking to a nurse on the telephone, or giving information in person. CONCLUSIONS: The uptake of new, potentially cost-effective technology-based methods of monitoring patients' symptoms at home might be limited by patients' initial discomfort with the idea of using them. It will be important to develop methods of addressing this potential barrier (such as detailed explanation and supervised practice) if these methods are to be successfully implemented

Multibudded tubules formed by COPII on artificial liposomes

COPII-coated vesicles form at the endoplasmic reticulum for cargo transport to the Golgi apparatus. We used in vitro reconstitution to examine the roles of the COPII scaffold in remodeling the shape of a lipid bilayer. Giant Unilamellar Vesicles were examined using fast confocal fluorescence and cryo-electron microscopy in order to avoid separation steps and minimize mechanical manipulation. COPII showed a preference for high curvature structures, but also sufficient flexibility for binding to low curvatures. The COPII proteins induced beads-on-a-string-like constricted tubules, similar to those previously observed in cells. We speculate about a mechanical pathway for vesicle fission from these multibudded COPII-coated tubules, considering the possibility that withdrawal of the Sar1 amphipathic helix upon GTP hydrolysis leads to lipid bilayer destabilization resulting in fission

The RNA Binding Protein SAM68 Transiently Localizes in the Chromatoid Body of Male Germ Cells and Influences Expression of Select MicroRNAs

The chromatoid body (CB) is a unique structure of male germ cells composed of thin filaments that condense into a perinuclear organelle after meiosis. Due to the presence of proteins involved in different steps of RNA metabolism and of different classes of RNAs, including microRNAs (miRNAs), the CB has been recently suggested to function as an RNA processing centre. Herein, we show that the RNA binding protein SAM68 transiently localizes in the CB, in concomitance with the meiotic divisions of mouse spermatocytes. Precise staging of the seminiferous tubules and co-localization studies with MVH and MILI, two well recognized CB markers, documented that SAM68 transiently associates with the CB in secondary spermatocytes and early round spermatids. Furthermore, although SAM68 co-immunoprecipitated with MVH in secondary spermatocytes, its ablation did not affect the proper localization of MVH in the CB. On the other hand, ablation of the CB constitutive component MIWI did not impair association of SAM68 with the CB. Isolation of CBs from Sam68 wild type and knockout mouse testes and comparison of their protein content by mass spectrometry indicated that Sam68 ablation did not cause overall alterations in the CB proteome. Lastly, we found that SAM68 interacts with DROSHA and DICER in secondary spermatocytes and early round spermatids and that a subset of miRNAs were altered in Sam68−/−germ cells. These results suggest a novel role for SAM68 in the miRNA pathway during spermatogenesis

A Wireless Health Outcomes Monitoring System (WHOMS): development and field testing with cancer patients using mobile phones

BACKGROUND: Health-Related Quality of Life assessment is widely used in clinical research, but rarely in clinical practice. Barriers including practical difficulties administering printed questionnaires have limited their use. Telehealth technology could reduce these barriers and encourage better doctor-patient interaction regarding patient symptoms and quality-of-life monitoring. The aim of this study was to develop a new system for transmitting patients' self-reported outcomes using mobile phones or the internet, and to test whether patients can and will use the system via a mobile phone. METHODS: We have developed a prototype of a Wireless Health Outcomes Monitoring System, which allows structured questionnaires to be sent to the patient by their medical management team. The patients' answers are directly sent to an authorised website immediately accessible by the medical team, and are displayed in a graphic format that highlights the patient's state of health. In the present study, 97 cancer inpatients were asked to complete a ten-item questionnaire. The questionnaire was delivered by display on a mobile phone, and was answered by the patients using the mobile phone keypad. RESULTS: Of the 97 patients, 56 (58%) attempted the questionnaire, and all of these 56 completed it. Only 6% of the total number of questions were left unanswered by patients. Forty-one (42%) patients refused to participate, mostly due to their lack of familiarity with mobile phone use. Compared with those who completed the questionnaire, patients who refused to participate were older, had fewer years of education and were less familiar with new communications technology (mobile phone calls, mobile phone SMS, internet, email). CONCLUSION: More than half of the patients self-completed the questionnaire using the mobile phone. This proportion may increase with the use of multichannel communications which can be incorporated into the system. The proportion may also increase if the patient's partner and/or family were able to assist the patient with using the technology. These preliminary results encourage further studies to identify specific diseases or circumstances where this system could be useful in patients' distance monitoring. Such a system is likely to detect patient suffering earlier, and to activate a well-timed intervention

Peri-conception and first trimester diet modifies reproductive development in bulls

Nutritional perturbation during gestation alters male reproductive development in rodents and sheep. In cattle both the developmental trajectory of the feto–placental unit and its response to dietary perturbations is dissimilar to that of these species. This study examined the effects of dietary protein perturbation during the peri-conception and first trimester periods upon reproductive development in bulls. Nulliparous heifers (n = 360) were individually fed a high- or low-protein diet (HPeri and LPeri) from 60 days before conception. From 24 until 98 days post conception, half of each treatment group changed to the alternative post-conception high- or low-protein diet (HPost and LPost) yielding four treatment groups in a 2 × 2 factorial design. A subset of male fetuses (n = 25) was excised at 98 days post conception and fetal testis development was assessed. Reproductive development of singleton male progeny (n = 40) was assessed until slaughter at 598 days of age, when adult testicular cytology was evaluated. Low peri-conception diet delayed reproductive development: sperm quality was lowered during pubertal development with a concomitant delay in reaching puberty. These effects were subsequent to lower FSH concentrations at 330 and 438 days of age. In the fetus, the low peri-conception diet increased the proportion of seminiferous tubules and decreased blood vessel area in the testis, whereas low first trimester diet increased blood vessel number in the adult testis. We conclude that maternal dietary protein perturbation during conception and early gestation may alter male testis development and delay puberty in bulls