Activated 4E-BP1 represses tumourigenesis and IGF-I-mediated activation of the eIF4F complex in mesothelioma.

BACKGROUND: Insulin-like growth factor (IGF)-I signalling stimulates proliferation, survival, and invasion in malignant mesothelioma and other tumour types. Studies have found that tumourigenesis is linked to dysregulation of cap-dependent protein translation. METHODS: The effect of IGF stimulation on cap-mediated translation activation in mesothelioma cell lines was studied using binding assays to a synthetic 7-methyl GTP-cap analogue. In addition, cap-mediated translation was genetically repressed in these cells with a dominant active motive of 4E-BP1. RESULTS: In most mesothelioma cell lines, IGF-I stimulation resulted in a hyperphosphorylation-mediated inactivation of 4E-BP1 compared with that in normal mesothelial cells. An inhibitor of Akt diminished IGF-I-mediated phosphorylation of 4E-BP1, whereas inhibiting MAPK signalling had no such effect. IGF-I stimulation resulted in the activation of the cap-mediated translation complex as indicated by an increased eIF4G/eIF4E ratio in cap-affinity assays. Akt inhibition reversed the eIF4G/eIF4E ratio. Mesothelioma cells transfected with an activated 4E-BP1 protein (4E-BP1(A37/A46)) were resistant to IGF-I-mediated growth, motility, and colony formation. In a murine xenograft model, mesothelioma cells expressing the dominant active 4E-BP1(A37/A46) repressor protein showed abrogated tumourigenicity compared with control tumours. CONCLUSION: IGF-I signalling in mesothelioma cells drives cell proliferation, motility, and tumourigenesis through its ability to activate cap-mediated protein translation complex through PI3K/Akt/mTOR signalling.

Assessment of CPR Knowledge among Clinical Radiography Students at a Tertiary Institution in Nigeria

Background: Current state of practice of medical imaging now encompasses advancesupportive care to patient, in addition to the supportive care offered for the stabilization of patient before radiologic procedures. Advance supportive care, such as Cardiopulmonary Resuscitation (CPR) is offered to patient who may have cardiopulmonary arrests.Objective: To assess the knowledge of cardiopulmonary resuscitation (CPR) among clinical radiography students of a tertiary institution in Sokoto. Methods:A cross section study employing a semi-structured and self-administered questionnaire, consisting of two section, designed with the aim of the study were distributed among 82 clinical radiography students (300 –500 level), in the 2017/2018 academy session of the tertiary institution (Usmanu Danfodiyo University) in Sokoto. The data were extracted using SPSS version 20 and analysed using descriptive and inferential statistics.Results: A total of 75 questionnaire were returned, yielding a response rate of 91.5%. Respondents comprised 53 male and 22 female aged 20 to 34 years with mean age of 27 years. It was observed that 68% of the students had never had a CPR training and about 4% of the respondents knew the recommended compression to ventilation ratio during a CPR. While 1.3% knew the recommended chest compression to be performed each minute when giving CPR. Majority of the respondents (94.7%) were of the opinion, that CPR training should be made mandatory for all clinical radiography students.Conclusion:Base on the evidence presented within this study, there is knowledge gap in the practice of cardiopulmonary resuscitation (CPR) among clinical radiography students, as majority of the students do not have adequate knowledge on the practice of CPR.