Targeted MYCN suppression and its effect on miRNA in neuroblastoma

Neuroblastoma is the most common extra-cranial tumour disease in children, and accounts for 15% of all childhood cancer deaths. MYCN is a transcription factor and a proto-oncogene that most often initiates transcription of target genes involved in increased proliferation and inhibition of differentiation. MYCN amplified neuroblastoma represents the most aggressive form of this disease. Silencing of MYCN is an attractive approach for understanding the role of this gene in development and disease. MYCN is involved in development, proliferation and differentiation. In order to explore its functions in detail, it is a great advantage to be able to silence its expressions in all cells present for an indefinite period of time, and at any suitable time-point. In paper I we describe a novel design of an inducible H1 promoter capable of delivering shRNA in a conditional manner. This versatile system allows inducible expression of any desired shRNA. In paper II this promoter is used to control the conditional expression of anti-MYCN shRNAs from cassettes stably integrated in two MYCN-amplified cell lines. Here MYCN is silenced when the inducer doxycycline is added to the media, resulting in increased differentiation and reduced proliferation of the MYCN amplified cell lines. MiRNAs are small non-coding RNA shown to regulate the expression of a vast amount of proteins in humans. In paper III we investigate the effect of MYCN suppression on the global miRNA expression in MYCN-amplified neuroblastoma. We find that reduced MYCN expression leads to both increased and reduced expression of several miRNAs. The function of mir-21 is investigated further, and no effect on neither proliferation nor differentiation is found. Other miRNAs demonstrated to be regulated by MYCN, is mir-92a and mir-92b. In paper IV we demonstrate how these miRNAs suppresses the expression of DKK3, a tumour suppressor gene often found to be down-regulated in MYCN-amplified neuroblastoma

Trade, Manufacture, Dismantling and Reassembling? Metal Processing and Eastern Ornaments at Brodtkorbneset and Steintjørna

This article takes as its starting point artefacts recovered from excavations at Brodtkorbneset and Steintjørna, or rather a focus on selected categories of artefacts retrieved from these sites. These categories are artefacts related to iron processing, imported iron tools and cut pieces of copper alloy implements and ornaments. The artefacts are discussed in the light of the North Fennoscandian context. As all categories were brought to the sites over long distances, and the likely routes of traded iron, copper alloy vessels, cauldrons and kettles seem to have been through the interior of Finland, these objects were most likely part of Trans-Bothnian trade networks. The eastern ornaments seem to be connected with a mainly Novgorodian fur-trade network, with Karelian traders acting as intermediaries. The involvement of Karelians could have meant an extension of the inland trade routes, possibly including the western White Sea area and alternative routes of a south-eastern – south-western direction. It is argued that the advantage of the Gulf of Bothnia was its central position as a transit area for long-distance trade and the distribution of objects to the upper Pasvik area in theearly Iron Age/Early Middle Ages. The discussion therefore ends with a comparison of the models of trading networks and communities proposed for the area, and the context ofhearth-row sites excavated in upper Pasvik (Fig 1)

Faglig program 2020 - 2025. Arkeologiske undersøkelser. Norges arktiske universitetsmuseum

Source at https://uit.no/Content/665361/cache=20200302150033/Faglig%20program_endelig%20240120.pdf. Home page for Tromsø Museums Rapportserie: https://uit.no/tmu/art?p_document_id=546084.Dette er det andre Faglige programmet utarbeidet av Norges arktiske universitetsmuseum. Et av de viktigste formålene med programmet er å oppsummere kunnskapsstatus for derigjennom å identifisere kunnskapshull. Dette er avgjørende for å kunne skape et grunnlag for å kunne gjøre prioriteringer og å utforme faglige strategier for forvaltningsarkeologien. Dette programmet skiller seg nokså mye fra det første (Faglig program for Tromsø Museum – Universitetsmuseet 2010 – 2012), og den viktigste endringen er en forskyvning fra geografisk og kronologisk avgrensede satsinger til et fokus på tematiske satsinger. Hva og hvor i forvaltningsarkeologien styres hovedsak av samfunnsutviklingen og vi kan i liten grad velge hvor vi vil gjennomføre utgravninger. Det er vår tro at en slik endring vil gjøre dette andre faglige programmet til et bedre arbeidsredskap

Maternal pre-pregnancy obesity and timing of puberty in sons and daughters: a population-based cohort study.

BackgroundIn many countries, an increased prevalence of obesity in pregnancy has coincided with a declining pubertal age. We aimed to explore the potential effect of maternal pre-pregnancy overweight and obesity on timing of puberty in sons and daughters.MethodsBetween 2012 and 2018, 15 819 of 22 439 invited children from the Danish National Birth Cohort, born 2000-03, provided half-yearly information from the age of 11 years on the pubertal milestones: Tanner stages, voice break, first ejaculation, menarche, acne and axillary hair. We estimated adjusted mean monthly differences (with 95% confidence intervals) in age at attaining the pubertal milestones for children exposed to maternal pre-pregnancy obesity [body mass index (BMI) ≥30.0 kg/m2] or overweight (BMI 25.0 to 29.9 kg/m2) with normal weight (BMI 18.5 to 24.9 kg/m2) as reference. In mediation analysis, we explored whether childhood BMI at age 7 years mediated the associations.ResultsMaternal pre-pregnancy obesity was associated with earlier age at attaining most pubertal milestones in sons, and pre-pregnancy overweight and obesity were associated with earlier age at attaining all pubertal milestones in daughters. When combining all pubertal milestones, pre-pregnancy obesity [sons: -1.5 (-2.5, -0.4) months; daughters: -3.2 (-4.2, -2.1) months] and overweight [daughters only: -2.6 (-3.3, -1.8) months] were associated with earlier timing of puberty. The associations in sons were completely mediated by higher childhood BMI and partly so in daughters.ConclusionsMaternal pre-pregnancy obesity appears to lower timing of puberty through childhood obesity in sons and mainly through other mechanisms in daughters

Risk of selection bias due to non-participation in a cohort study on pubertal timing.

BackgroundNon-participation in aetiologic studies of pubertal timing is frequent. However, little effort has been given to explore the risk and potential impact of selection bias in studies of pubertal timing.ObjectiveWe aimed to explore the risk of selection bias due to non-participation in a newly established puberty cohort.MethodsWe evaluated whether three maternal exposures chosen a priori (pre-pregnancy obesity, smoking, and alcohol drinking during pregnancy) were associated with participation, whether pubertal timing was associated with participation, and whether selection bias influenced the associations between these exposures and pubertal timing. In total, 22 439 children from the Danish National Birth Cohort born 2000-2003 were invited to the Puberty Cohort and 15 819 (70%) participated. Exposures were self-reported during pregnancy. Pubertal timing was measured using a previously validated marker, "the height difference in standard deviations" (HD:SDS), which is the difference between pubertal height and adult height, both in standard deviations. For this study, pubertal height at around 13 years in sons and around 11 years in daughters was obtained from an external database, and adult height was predicted based on parental height reported by mothers.ResultsParticipation was associated with most exposures but not with pubertal timing, measured by HD:SDS. The associations between exposures and HD:SDS were comparable for participants only and all invited for participation.ConclusionIn conclusion, the risk of selection bias in aetiologic studies on pubertal timing in the Puberty Cohort appears minimal

Selective serotonin reuptake inhibitors in pregnancy and congenital malformations: population based cohort study

Objective To investigate any association between selective serotonin reuptake inhibitors (SSRIs) taken during pregnancy and congenital major malformations

Comparison of RNAi efficiency mediated by tetracycline-responsive H1 and U6 promoter variants in mammalian cell lines

Conditional expression of short hairpin RNAs (shRNAs) to knock down target genes is a powerful tool to study gene function. The most common inducible expression systems are based on tetracycline-regulated RNA polymerase III promoters. During the last years, several tetracycline-inducible U6 and H1 promoter variants have been reported in different experimental settings showing variable efficiencies. In this study, we compare the most common variants of these promoters in several mammalian cell lines. For all cell lines tested, we find that several inducible U6 and H1 promoters containing single tetracycline operator (tetO) sequences show high-transcriptional background in the non-induced state. Promoter variants containing two tetO sequences show tight suppression of transcription in the non-induced state, and high tet responsiveness and high gene knockdown efficiency upon induction in all cell lines tested. We report a variant of the H1 promoter containing two O2-type tetO sequences flanking the TATA box that shows little transcriptional background in the non-induced state and up to 90% target knockdown when the inducer molecule (dox–doxycycline) is added. This inducible system for RNAi-based gene silencing is a good candidate for use both in basic research on gene function and for potential therapeutic applications