The Role of Sphingosine Kinase 2 in Cell Growth and Apoptosis

Two isoforms of sphingosine kinase (SphK) catalyze the formation of sphingosine-1-phosphate (SIP). Whereas, SphKl stimulates cell growth and survival, it was found that when overexpressed in mouse NIH 3T3 fibroblasts SphK2 enhances caspase-dependent apoptosis in response to serum deprivation, independently of S1P receptors. Sequence analysis revealed that SphK2 contains a 9 amino acid motif similar to that present in BH3-only proteins. Studies showed that the BH3-only domain, catalytic activity, endoplasmic reticulum (ER) stress, and uptake of calcium by the mitochondria may all contribute to the apoptotic effects of overexpressed SphK2 in NIH 3T3 cells. Further studies in human carcinoma cells showed that overexpression of SphK2 increased the expression of the cyclin dependent kinase (cdk) inhibitor p21, but interestingly had no effect on p53 or its phosphorylation. Correspondingly, downregulation of endogenous SphK2 with small interfering RNA (siRNA) targeted to unique mRNA sequences decreased basal and doxorubicin-induced expression of p21 without affecting p53. In addition, downregulation of SphK2 decreased G2/M arrest in response to doxorubicin. Surprisingly however, siSphK2 markedly enhanced apoptosis induced by doxorubicin in MCF7 and HCT-116 cells. This result raises the question of how overexpression of SphK2 decreases cell growth and enhances apoptosis while its downregulation sensitizes cells to apoptosis. A partial answer may come from the possibility that when SphK2 is overexpressed it does not always have the same subcellular distribution as the endogenous protein. It may also be possible that proteolysis of overexpressed SphK2 might induce apoptosis due to liberation of its BH3 peptide domain, which does not occur at the levels at which endogenous SphK2 is expressed. Collectively, these results demonstrate that endogenous SphK2 is important for p53-independent induction of p21 expression by doxorubicin and suggest that SphK2 expression may influence the balance between cytostasis and apoptosis

A Phase II Trial of AZD6244 (Selumetinib, ARRY-142886), an Oral MEK1/2 Inhibitor, in Relapsed/Refractory Multiple Myeloma

AZD6244 is a MEK1/2 inhibitor with significant preclinical activity in multiple myeloma (MM) cells. This phase 2 study used a two-stage Simon design to determine the AZD6244 response rate in patients with relapsed or refractory MM

ENSIHOITAJAN (AMK) OSAAMISVAATIMUKSET TULEVAISUUDESSA : Ensihoitajien (AMK) osaamisvaatimuksia sairaalan ulkopuolisessa ympäristössä Pohjois-Pohjanmaan sairaanhoitopiirin alueella vuonna 2025

Ensihoito on jatkuvassa muutoksessa. Ensihoitopalvelut kehittyvät, päivystyspisteet keskittyvät, potilaat ovat monisairaampia ja väestö ikääntyy. Myös hoito- ja viestintäteknologia kehittyvät ja monikulttuurisuus ja kansainvälistyminen vaikuttavat enenevissä määrin ensihoitajan työhön. Ensihoidossa tarvittavan osaamisen vaatimukset kasvavat jatkuvasti ja kentällä vaaditaan tulevaisuudessa yhä korkeatasoisempaa osaamista. Tästä syystä myös ensihoitajien (AMK) koulutusta on kehitettävä jatkuvasti. Opinnäytetyön tarkoituksena oli selvittää ensihoitajien (AMK) osaamisvaatimuksia sairaalan ulkopuolisessa ympäristössä vuonna 2025. Tavoitteena oli saada sellaista tietoa, jonka avulla koulutusta voidaan kehittää odotusten mukaisesti vastaamaan tulevaisuuden vaatimuksiin. Tutkimus suoritettiin delfi-tutkimusmenetelmällä. Tutkimuksen toteutimme Pohjois-Pohjanmaan sairaanhoitopiirin alueella ja siihen osallistui yhteensä 14 alueen ensihoidossa työskentelevää ensihoitajaa (AMK). Tutkimuksella saimme esille ensihoitajien (AMK) oletuksia ja odotuksia tulevaisuuden osaamisvaatimuksista ja haasteista. Tutkimustulosten perusteella voidaan sanoa, että tulevaisuudessa ensihoitajan osaamisvaatimukset laajentuvat entisestään. Tulevaisuuden ensihoitaja (AMK) on jatkuvasti kouluttautuva asiakaspalvelija. Hän on valmis kohtaamaan muitakin kuin hätätilapotilaita ja hallitsee potilaan kokonaisvaltaisen hoidon enenevissä määrin myös potilaan kotona. Ensihoitaja (AMK) kykenee myös vastaamaan kehittyvän teknologian ja lääkehoidon haasteisiin. Tutkimustulosten mukaan ensihoitaja (AMK) -koulutuksen tulee pitää sisällään edelleen sekä ensihoidollisia että sairaanhoidollisia opintoja. Tulevaisuudessa ensihoidon opettajien tulee edelleen olla mukana käytännön ensihoitotyössä voidakseen tarjota opiskelijoille mahdollisimman työelämälähtöistä opetusta. Lähi- ja simulaatio-opetuksen määrää ei tule vähentää ensihoitaja (AMK) -koulutuksen laadun ylläpitämiseksi. Tutkimuksen tuloksia voidaan käyttää Oulun ammattikorkeakoulun ensihoitaja (AMK) -koulutuksen ja ensihoidon täydennyskoulutusten kehittämiseen. Lisäksi ensihoitopalveluiden järjestäjät voivat halutessaan käyttää tuloksia esimerkiksi henkilökunnan koulutuksia suunnitellessaan.Emergency care is changing continuously. Emergency care systems are developing, emergency care services are centralized, patients are more diverse and the population is aging. The technology in nursing equipment as well as in communication is developing and the increase of multiculturalism and internationality has impact to the work of a paramedic. The required competence of a paramedic is expanding and still higher quality of competence is required in the working life. Thus the education of the degree programme in emergency care (BSc) is to be adjusted continuously. The purpose of this study was to find out the required competences of a paramedic at pre-hospital emergency care in 2025. As a result of this study assumptions and expectations of paramedics were found out considering future requirements of competence and challenges. The study aims to discover information that can be used to develop the education of the degree programme in emergency care (BSc) by Oulu University of Applied Sciences to cover the future challenges. The study was carried out by using the Delphi method. There were altogether 14 paramedics that participated in this study from the Emergency medical services in the Northern Ostrobothnia Hospital District. As a result of this study it can be said that the requirements of the competences of a paramedic are expanding in the future. In 2025 a paramedic is a continuously studying customer oriented servant who is ready to help also other patients than those who need emergency care. A paramedic is able to meet the challenges of advancing technology and medical treatment as well as manage the holistic care of patients also more often at non-urgent situations. The education of a paramedic should include emergency care lectures as well as health care education. In the future the emergency care teachers should simultaneously work in the field of emergency care to provide practically and professionally competent education. Contact teaching and simulations should not be reduced in order to hold the quality of paramedic education as high as possible. The results can also be used for example in order to plan further education for the staff by the Emergency medical services in the Northern Ostrobothnia Hospital District

Pleiotropic actions of sphingosine-1-phosphate

Sphingosine-1-phosphate (SIP) is a bioactive sphingolipid metabolite that regulates diverse cellular responses including, growth, survival, cytoskeleton rearrangements and movement. SIP plays an important role during development, particularly in vascular maturation and has been implicated in pathophysiology of cancer, wound healing, and atherosclerosis. This review summarizes the evidence showing that signaling induced by SIP is complex and involves both intracellular and extracellular actions. The intracellular effects of SIP remain speculative awaiting the identification of specific targets whereas the extracellular effects of SIP are clearly mediated through the activation of five specific G protein coupled receptors, called S1P1-5. Recent studies demonstrate that intracellular generated SIP can act in a paracrine or autocrine manner to activate its cell surface receptors

Expression of SphK1 impairs degranulation and motility of RBL-2H3 mast cells by desensitizing S1P receptors

Mast cells play a central role in inflammatory and immediate-type allergic reactions by secreting a variety of biologically active substances, including sphingosine-1 phosphate (S1P). Sphingosine kinase 1 (SphK1) and formation of S1P, which leads to transactivation of S1P receptors and their downstream signaling pathways, regulates mast-cell functions initiated by cross-linking of the high-affinity immunoglobulin E (IgE) receptor FcεRI. Surprisingly, overexpression of SphK1 in rat basophilic leukemia (RBL)-2H3 mast cells impaired degranulation as well as migration toward antigen. These effects were reversed by serum withdrawal, yet the increased formation and secretion of S1P were the same as in the presence of serum. Nonetheless, serum increased localization of SphK1 at the plasma membrane. This restricted formation of S1P induced internalization and desensitization of S1P receptors on the surface of mast cells as determined by confocal immunofluorescence microscopy, aberrant S1P receptor signaling, and lack of S1P receptor coupling to G proteins. Serum starvation, which significantly reduced membrane-associated SphK1 activity, restored S1P receptor functions. Our results have important implications for mast-cell migration and degranulation as well as for the biologic functions of the S1P receptors on cells that are circulating in the bloodstream. (Blood. 2005;105:4736-4742

A Phase II Study of the MEK 1/2 Inhibitor AZD6244 (Selumetinib, ARRY-142866) in Relapsed or Refractory Multiple Myeloma

Abstract Abstract 2931 AZD6244 is a potent, selective, oral, non-ATP competitive small molecule inhibitor of the mitogen-activated protein kinase, MEK 1/2 that has shown significant pre-clinical activity in multiple myeloma (MM) cells, both in vitro and in vivo, as well as a favorable clinical profile. The present phase II study was designed to determine the response rate for AZD6244 in patients with relapsed or refractory MM. The study utilized a two-stage Simon design to allow for early termination if there was strong evidence of regimen inactivity. Eligible patients were restricted to those with MM who have had at least 2 prior regimens. AZD6244 capsules (75 mg) were administered orally twice daily continuously for 28 day cycles. Response was evaluated after 3 cycles. To date, 37 patients have been enrolled (13 in the 1st stage and 24 in the 2nd stage). One subject enrolled in the 1st stage was not treated. Gender enrollment was balanced (male/female 18/19). The median age of treated patients was 65 years [range 43–81]. ECOG performance scores ranged from 0–2. The median number of prior therapies was 5 [range 2–11]. The most common treatment-related adverse events (occurring in 10–50% of patients) were leukopenia, acneiform rash and other skin/subcutaneous tissue manifestations, fatigue, limb edema, increased aspartate aminotransferase (AST), neutropenia, nausea, facial edema, vomiting, thrombocytopenia, increased creatine phosphokinase, and diarrhea. The most common grade 3 and 4 toxicities (CTCAE v4) included fatigue, peripheral sensory neuropathy, increased AST, neutropenia, nausea, hypotension, thrombocytopenia, increased alanine aminotransferase, and diarrhea. Five deaths have occurred: 2 associated with sepsis, 1 associated with acute kidney injury, all deemed possibly related to AZD6244; and 2 due to disease progression after discontinuation of study treatment. Two objective partial responses have been reported, the first of which justified expansion of the study to the 2nd stage. Twelve patients have had a best response of stable disease, 11 patients have had progressive disease, 1 patient withdrew after cycle 1 (unrelated to toxicity) and did not have response assessed, 3 patients died before response was assessed, and 7 patients are too early to evaluate. Accrual is ongoing to determine if the response threshold in the 2nd stage can be met. Correlative studies are ongoing and are designed to identify potential mechanisms of response/resistance to AZD6244, and to determine the effect of AZD6244 on the bone marrow microenvironment. These include, among others, assessment of pre- and post-treatment expression of phospho-MEK 1/2 and -ERK 1/2, and total levels of Bim. Fifteen patients consented to correlative sampling of bone marrow, blood and/or urine. Results and sample analysis are pending. It is concluded that AZD6244 has modest activity as a single agent in relapsed or refractory MM. This trial also provides a foundation for successor studies employing the MEK 1/2 inhibitor AZD6244 in combination with other agents in patients with MM. Disclosures: Voorhees: Pfizer: Research Funding; Centocor Ortho Biotech: Research Funding; Celgene: Research Funding; MedImmune: Consultancy; Merck: Research Funding