Browsing by Subject "gene expression"

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  • Untiveros, Milton; Olspert, Allan; Artola, Katrin; Firth, Andrew E.; Kreuze, Jan F.; Valkonen, Jari P. T. (2016)
    The single-stranded, positive-sense RNA genome of viruses in the genus Potyvirus encodes a large polyprotein that is cleaved to yield 10 mature proteins. The first three cleavage products are P1, HCpro and P3. An additional short open reading frame (ORF), called pipo, overlaps the P3 region of the polyprotein ORF. Four related potyviruses infecting sweet potato (Ipomoea batatas) are predicted to contain a third ORF, called pispo, which overlaps the 3 third of the P1 region. Recently, pipo has been shown to be expressed via polymerase slippage at a conserved GA(6) sequence. Here, we show that pispo is also expressed via polymerase slippage at a GA(6) sequence, with higher slippage efficiency (approximate to 5%) than at the pipo site (approximate to 1%). Transient expression of recombinant P1 or the transframe' product, P1N-PISPO, in Nicotiana benthamiana suppressed local RNA silencing (RNAi), but only P1N-PISPO inhibited short-distance movement of the silencing signal. These results reveal that polymerase slippage in potyviruses is not limited to pipo expression, but can be co-opted for the evolution and expression of further novel gene products.
  • Einarsdottir, Elisabet; Pekkinen, Minna; Krjutskov, Kaarel; Katayama, Shintaro; Kere, Juha; Mäkitie, Outi; Viljakainen, Heli (2019)
    Objective: The effect of vitamin D at the transcriptome level is poorly understood, and furthermore, it is unclear if it differs between obese and normal-weight subjects. The objective of the study was to explore the transcriptome effects of vitamin D supplementation. Design and methods: We analysed peripheral blood gene expression using GlobinLock oligonucleotides followed by RNA sequencing in individuals participating in a 12-week randomised double-blinded placebo-controlled vitamin D intervention study. The study involved 18 obese and 18 normal-weight subjects (of which 20 males) with mean (+/- s.D.) age 20.4 (+/- 2.5) years and BMIs 36 (+/- 10) and 23 (+/- 4) kg/m(2), respectively. The supplemental daily vitamin D dose was 50 mu g (2000 IU). Data were available at baseline, 6- and 12-week time points and comparisons were performed between the vitamin D and placebo groups separately in obese and normal-weight subjects. Results: Significant transcriptomic changes were observed at 6 weeks, and only in the obese subjects: 1724 genes were significantly upregulated and 186 genes were downregulated in the vitamin D group compared with placebo. Further analyses showed several enriched gene categories connected to mitochondrial function and metabolism, and the most significantly enriched pathway was related to oxidative phosphorylation (adjusted P value 3.08 x 10(-14)). Taken together, our data suggest an effect of vitamin D supplementation on mitochondrial function in obese subjects. Conclusions: Vitamin D supplementation affects gene expression in obese, but not in normal-weight subjects. The altered genes are enriched in pathways related to mitochondrial function. The present study increases the understanding of the effects of vitamin D at the transcriptome level.
  • Jäppinen, Sanni (Helsingfors universitet, 2013)
    Filamentous cyanobacteria taxa Nostocales and Stigonematales cells can differentiate into heterocysts nitrogen fixing cells when nitrogen is limiting the growth and into resting cells akinetes when nutrients decrease or the growth conditions become unfavorable for growth. Akinetes overwinter in the water sediments during the unfavorable growth time. When the growing condition improves akinetes germinate and can start a new cyanobacterial bloom. Akinete differentiation remains unclear. It is known from the literature that only a few akinete specific genes exist. First described akinete specific gene was avak. The morphological changes of akinete differentiation are known but the changes at molecular genetics level in regulation and differentiation remains unclear. The aim of this study was to design a method for akinete differentiation-related genes, avak, hepA and hap, for an Anabaena 1TU33s10 strain and to monitor the gene expression changes in a seven-week growth experiment. Primers for the differentiation related genes were designed based on the known whole genome sequence of the Anabaena 1TU3310 strain. In this study it was managed to design a quantitative reverse transcriptase polymerase chain reaction, qRT-PCR method, based on the genes involved in the akinete differentiation process. It was observed that gene expression changed when akinetes began to differentiate into the filaments. In the growth experiment II avaK-gene expression was increased 2-fold between the 14. and 30. days, and hap-gene showed 1.5 fold growth between 14. and 30. days. The number of akinetes was also increasing at the same time. In the growth experiment I heap-gene showed 1-8 fold growth between the days 21. and 27. –30. days when the number of heterocysts were also increasing. The number of akinetes was relatively low compared to number of vegetative cells which also explains the small expression fold-differences in the cultures during the experiment time when compared to expression fold-differences described in the literature. Designed method can thus also detect minor changes in gene expression. The designed and built qRT-PCR method can be used in the future for monitoring gene expression changes also for new akinete specific genes, and the method can be further optimized for screening natural water samples.
  • Holster, Savanne; Hooiveld, Guido J.; Repsilber, Dirk; de Vos, Willem M.; Brummer, Robert J.; König, Julia (2019)
    Faecal microbiota transfer (FMT) consists of the introduction of new microbial communities into the intestine of a patient, with the aim of restoring a disturbed gut microbiota. Even though it is used as a potential treatment for various diseases, it is unknown how the host mucosa responds to FMT. This study aims to investigate the colonic mucosa gene expression response to allogenic (from a donor) or autologous (own) FMT in patients with irritable bowel syndrome (IBS). In a recently conducted randomised, double-blinded, controlled clinical study, 17 IBS patients were treated with FMT by colonoscopy. RNA was isolated from colonic biopsies collected by sigmoidoscopy at baseline, as well as two weeks and eight weeks after FMT. In patients treated with allogenic FMT, predominantly immune response-related gene sets were induced, with the strongest response two weeks after the FMT. In patients treated with autologous FMT, predominantly metabolism-related gene sets were affected. Furthermore, several microbiota genera showed correlations with immune-related gene sets, with different correlations found after allogenic compared to autologous FMT. This study shows that the microbe-host response is influenced by FMT on the mucosal gene expression level, and that there are clear differences in response to allogenic compared to autologous FMT.
  • Miettinen, Juho; Kumari, Romika; Traustadottir, Gunnhildur Asta; Huppunen, Maiju-Emilia Anniina; Sergeev, Philipp; Majumder, Muntasir M.; Schepsky, Alexander; Gudjonsson, Thorarinn; Lievonen, Juha; Bazou, Despina; Dowling, Paul; O'Gorman, Peter; Slipicevic, Ana; Anttila, Pekka; Silvennoinen, Raija; Nupponen, Nina N.; Lehmann, Fredrik; Heckman, Caroline (2021)
    Multiple myeloma (MM) is characterized by extensive immunoglobulin production leading to an excessive load on protein homeostasis in tumor cells. Aminopeptidases contribute to proteolysis by catalyzing the hydrolysis of amino acids from proteins or peptides and function downstream of the ubiquitin–proteasome pathway. Notably, aminopeptidases can be utilized in the delivery of antibody and peptide-conjugated drugs, such as melflufen, currently in clinical trials. We analyzed the expression of 39 aminopeptidase genes in MM samples from 122 patients treated at Finnish cancer centers and 892 patients from the CoMMpass database. Based on ranked abundance, LAP3, ERAP2, METAP2, TTP2, and DPP7 were highly expressed in MM. ERAP2, XPNPEP1, DPP3, RNPEP, and CTSV were differentially expressed between relapsed/refractory and newly diagnosed MM samples (p < 0.05). Sensitivity to melflufen was detected ex vivo in 11/15 MM patient samples, and high sensitivity was observed, especially in relapsed/refractory samples. Survival analysis revealed that high expression of XPNPEP1, RNPEP, DPP3, and BLMH (p < 0.05) was associated with shorter overall survival. Hydrolysis analysis demonstrated that melflufen is a substrate for aminopeptidases LAP3, LTA4H, RNPEP, and ANPEP. The sensitivity of MM cell lines to melflufen was reduced by aminopeptidase inhibitors. These results indicate critical roles of aminopeptidases in disease progression and the activity of melflufen in MM.
  • Salmela, Heli; Stark, Taina; Stucki, Dimitri; Fuchs, Siiri; Freitak, Dalial; Dey, Alivia; Kent, Clement F.; Zayed, Amro; Dhaygude, Kishor; Hokkanen, Heikki; Sundstrom, Liselotte (2016)
    Protection against inflammation and oxidative stress is key in slowing down aging processes. The honey bee (Apis mellifera) shows flexible aging patterns linked to the social role of individual bees. One molecular factor associated with honey bee aging regulation is vitellogenin, a lipoglycophosphoprotein with anti-inflammatory and antioxidant properties. Recently, we identified three genes in Hymenopteran genomes arisen from ancient insect vitellogenin duplications, named vg-like-A, -B, and -C. The function of these vitellogenin homologs is unclear. We hypothesize that some of them might share gene-and protein-level similarities and a longevity-supporting role with vitellogenin. Here, we show how the structure and modifications of the vg-like genes and proteins have diverged from vitellogenin. Furthermore, all three vg-like genes show signs of positive selection, but the spatial location of the selected protein sites differ from those found in vitellogenin. We show that all these genes are expressed in both long-lived winter worker bees and in summer nurse bees with intermediate life expectancy, yet only vg-like-A shows elevated expression in winter bees as found in vitellogenin. Finally, we show that vg-like-A responds more strongly than vitellogenin to inflammatory and oxidative conditions in summer nurse bees, and that also vg-like-B responds to oxidative stress. We associate vg-like-A and, to lesser extent, vg-like-B to the antiaging roles of vitellogenin, but that vg-like-C probably is involved in some other function. Our analysis indicates that an ancient duplication event facilitated the adaptive and functional divergence of vitellogenin and its paralogs in the honey bee.
  • Jia, S.; Zhou, J.; Wee, Y.; Mikkola, M. L.; Schneider, P.; D'Souza, R. N. (2017)
    To date, surgical interventions are the only means by which craniofacial anomalies can be corrected so that function, esthetics, and the sense of well-being are restored in affected individuals. Unfortunately, for patients with cleft palate-one of the most common of congenital birth defects-treatment following surgery is prolonged over a lifetime and often involves multidisciplinary regimens. Hence, there is a need to understand the molecular pathways that control palatogenesis and to translate such information for the development of noninvasive therapies that can either prevent or correct cleft palates in humans. Here, we use the well-characterized model of the Pax9(-/-) mouse, which displays a consistent phenotype of a secondary cleft palate, to test a novel therapeutic. Specifically, we demonstrate that the controlled intravenous delivery of a novel mouse monoclonal antibody replacement therapy, which acts as an agonist for the ectodysplasin (Eda) pathway, can resolve cleft palate defects in Pax9(-/-) embryos in utero. Such pharmacological interventions did not reverse the arrest in tooth, thymus, and parathyroid gland development, suggesting that the relationship of Pax9 to the Eda/Edar pathway is both unique and essential for palatogenesis. Expression analyses and unbiased gene expression profiling studies offer a molecular explanation for the resolution of palatal defects, showing that Eda and Edar-related genes are expressed in normal palatal tissues and that the Eda/Edar signaling pathway is downstream of Pax9 in palatogenesis. Taken together, our data uncover a unique relationship between Pax9 and the Eda/Edar signaling pathway that can be further exploited for the development of noninvasive, safe, and effective therapies for the treatment of cleft palate conditions and other single-gene disorders affecting the craniofacial complex.
  • Nykänen, Sonja (Helsingin yliopisto, 2019)
    Colorectal cancer (CRC) kills more than half a million people a year worldwide. Usually the disease develops over several years via multiple steps which involve both genetic and epigenetic alterations. CRC is often diagnosed at late stage, when the cancer has already metastasized, and the prognosis is relatively poor. Several studies suggest that the first changes towards colorectal cancer occur and can be detected in histologically normal tissue before the appearance of any detectable lesion. The precancerous cells harbouring those changes may form a field of tissue, which is predisposed to malignant transformation. The study of pre-cancerous tissue might reveal the earliest changes in CRC development, which can be used as biomarkers for early detection and prevention of CRC. The aim of this thesis was to revise and investigate whether the aberrant expression of the six chromosomal segregation genes, Bub1, Mis18a, Pms2, Rad9a, Tpx2, and Mlh1, would signal carcinogenesis in mouse colon mucosa. Altogether fourteen mice, of which six had a proximal colon carcinoma, were selected for the study. The expression analysis was performed to histologically normal colon mucosa collected from the proximal and distal colon of each mice in order to investigate whether the possible pre-cancerous changes are found exclusively in the close proximity to the carcinoma. The expression was quantified with reverse transcription quantitative polymerase chain reaction (RTqPCR). No statistically significant gene expression differences were found between the carcinoma and control mice, indicating that the studied mice did not display cancer-preceding expression changes of the six studied genes in the carcinoma adjacent histologically normal colon mucosa. The results differed from the previously reported results, where the expressions of the six genes were found to be downregulated in the carcinoma adjacent mucosa. Here, the sample size was presumably not large enough to reveal statistically significant clustering of the expression patterns. However, Bub1 seemed to have a downregulated trend in the carcinoma adjacent mucosa, which supports the previously suggested role of Bub1 alterations in CRC initiation.
  • Piran, Mehran; Karbalaei, Reza; Piran, Mehrdad; Aldahdooh, Jehad; Mirzaie, Mehdi; Ansari-Pour, Naser; Tang, Jing; Jafari, Mohieddin (2020)
    Studying relationships among gene products by expression profile analysis is a common approach in systems biology. Many studies have generalized the outcomes to the different levels of central dogma information flow and assumed a correlation of transcript and protein expression levels. However, the relation between the various types of interaction (i.e., activation and inhibition) of gene products to their expression profiles has not been widely studied. In fact, looking for any perturbation according to differentially expressed genes is the common approach, while analyzing the effects of altered expression on the activity of signaling pathways is often ignored. In this study, we examine whether significant changes in gene expression necessarily lead to dysregulated signaling pathways. Using four commonly used and comprehensive databases, we extracted all relevant gene expression data and all relationships among directly linked gene pairs. We aimed to evaluate the ratio of coherency or sign consistency between the expression level as well as the causal relationships among the gene pairs. Through a comparison with random unconnected gene pairs, we illustrate that the signaling network is incoherent, and inconsistent with the recorded expression profile. Finally, we demonstrate that, to infer perturbed signaling pathways, we need to consider the type of relationships in addition to gene-product expression data, especially at the transcript level. We assert that identifying enriched biological processes via differentially expressed genes is limited when attempting to infer dysregulated pathways.
  • Jalanka, Jonna; Cheng, Jing; Hiippala, Kaisa; Ritari, Jarmo; Salojärvi, Jarkko; Ruuska, Tarja; Kalliomaki, Marko; Satokari, Reetta (2020)
    Inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn's disease (CD), are chronic debilitating disorders of unknown etiology. Over 200 genetic risk loci are associated with IBD, highlighting a key role for immunological and epithelial barrier functions. Environmental factors account for the growing incidence of IBD, and microbiota are considered as an important contributor. Microbiota dysbiosis can lead to a loss of tolerogenic immune effects and initiate or exacerbate inflammation. We aimed to study colonic mucosal microbiota and the expression of selected host genes in pediatric UC. We used high-throughput 16S rDNA sequencing to profile microbiota in colonic biopsies of pediatric UC patients (n= 26) and non-IBD controls (n= 27). The expression of 13 genes, including five for antimicrobial peptides, in parallel biopsies was assessed with qRT-PCR. The composition of microbiota between UC and non-IBD differed significantly (PCoA,p= 0.001). UC children had a decrease in Bacteroidetes and an increase in several family-level taxa including Peptostreptococcaceae and Enterobacteriaceae, which correlated negatively with the expression of antimicrobial peptides REG3G and DEFB1, respectively. Enterobacteriaceae correlated positively with the expression siderophore binding protein LCN2 and Betaproteobacteria negatively with DEFB4A expression. The results indicate that reciprocal interaction of epithelial microbiota and defense mechanisms play a role in UC.
  • Kondelin, J.; Salokas, K.; Saarinen, L.; Ovaska, K.; Rauanheimo, H.; Plaketti, R.-M.; Hamberg, J.; Liu, X.; Yadav, L.; Gylfe, A.E.; Cajuso, T.; Hänninen, U.A.; Palin, K.; Ristolainen, H.; Katainen, R.; Kaasinen, E.; Tanskanen, T.; Aavikko, M.; Taipale, M.; Taipale, J.; Renkonen-Sinisalo, L.; Lepistö, A.; Koskensalo, S.; Böhm, J.; Mecklin, J.-P.; Ongen, H.; Dermitzakis, E.T.; Kilpivaara, O.; Vahteristo, P.; Turunen, M.; Hautaniemi, S.; Tuupanen, S.; Karhu, A.; Välimäki, N.; Varjosalo, M.; Pitkänen, E.; Aaltonen, L.A. (2018)
    Microsatellite instability (MSI) leads to accumulation of an excessive number of mutations in the genome, mostly small insertions and deletions. MSI colorectal cancers (CRCs), however, also contain more point mutations than microsatellite-stable (MSS) tumors, yet they have not been as comprehensively studied. To identify candidate driver genes affected by point mutations in MSI CRC, we ranked genes based on mutation significance while correcting for replication timing and gene expression utilizing an algorithm, MutSigCV. Somatic point mutation data from the exome kit-targeted area from 24 exome-sequenced sporadic MSI CRCs and respective normals, and 12 whole-genome-sequenced sporadic MSI CRCs and respective normals were utilized. The top 73 genes were validated in 93 additional MSI CRCs. The MutSigCV ranking identified several well-established MSI CRC driver genes and provided additional evidence for previously proposed CRC candidate genes as well as shortlisted genes that have to our knowledge not been linked to CRC before. Two genes, SMARCB1 and STK38L, were also functionally scrutinized, providing evidence of a tumorigenic role, for SMARCB1 mutations in particular. © 2018 The Authors. Published under the terms of the CC BY 4.0 license
  • Qin, Nanbing; Bayat, Ali-Reza; Trevisi, Erminio; Minuti, Andrea; Kairenius, Piia; Viitala, Sirja; Mutikainen, Mervi; Leskinen, Heidi; Elo, Kari Tapani; Kokkonen, Tuomo Juhani; Vilkki, Johanna (2018)
    To investigate the metabolic (.11, !I:2.es in the adipose tissue (AT) of dairy cows under milk fat depression (MFD), 30 cows were randomly allocated to a control diet, a conjugated linoleic acid (CLA)-supplemented diet, or a high-starch diet supplemented with a mixture of sunflower and fish oil (2:1; as HSO diet) from 1 to 112 d in milk. Performance of animals, milk yield, milk composition, energy balance, and blood metabolites were measured during lactation. Quantitative PCR analyses were conducted on the AT samples collected at wk 3 and 15 of lactation. The CLA and HSO diets considerably depressed milk fat yield and milk fat content at both wk 3 and 15 in the absence of significant changes in milk protein and lactose contents. In addition, the HSO diet lowered milk yield at wk 15 and decreased dry matter intake of cows from wk 3 to 15. Compared with the control, both CLA and HSO groups showed reduced body weight loss, improved energy balance, and decreased plasma concentrations of nonesterified fatty acids and beta-hydroxybutyrate at early lactation. The gene expression analyses reflected suppressed lipolysis in AT of the CLA and HSO groups compared with the control at wk 3, as suggested by the downregulation of hormone-sensitive lipase and fatty acid binding protein 4 and the upregulation of perilipin 2. In addition, the HSO diet promoted lipogenesis in AT at wk 15 through the upregulation of 1-acylglycerol-3-phosphate O-acyltransferase 2, mitochondria' glycerol-3-phosphate acyltransferase, perilipin 2, and peroxisome proliferator-activated receptor gamma. The CLA diet likely regulated insulin sensitivity in AT as it upregulated the transcription of various genes involved in insulin signaling, inflammatory responses, and ceramide metabolism, including protein kinase B2, nuclear factor kappa B1, toll-like receptor 4, caveolin 1, serine palmitoyltransferase long chain base subunit 1, and N-acylsphingosine amidohydrolase 1. In contrast, the HSO diet resulted in little or no change in the pathways relevant to insulin sensitivity. In conclusion, the CLA and HSO diets induced a shift in energy partitioning toward AT instead of mammary gland during lactation through the regulation of different pathways.
  • Salgado, Ana L.; Suchan, Tomasz; Pellissier, Loic; Rasmann, Sergio; Ducrest, Anne-Lyse; Alvarez, Nadir (2016)
    Elevation gradients impose large differences in abiotic and biotic conditions over short distances, in turn, likely driving differences in gene expression more than would genetic variation per se, as natural selection and drift are less likely to fix alleles at such a narrow spatial scale. As elevation increases, the pressure exerted on plants by herbivores and on arthropod herbivores by predators decreases, and organisms spanning the elevation gradient are thus expected to show lower levels of defence at high elevation. The alternative hypothesis, based on the optimal defence theory, is that defence allocation should be higher in low-resource habitats such as those at high elevation, due to higher costs associated with tissue replacement. In this study, we analyse variation with elevation in (i) defence compound content in the plant Lotus corniculatus and (ii) gene expression associated with defence against predators in the specific phytophagous moth, Zygaena filipendulae. Both species produce cyanogenic glycosides (CNglcs) such as lotaustralin and linamarin as defence mechanisms, with the moth, in addition, being able to sequester CNglcs from its host plant. Specifically, we tested the assumption that the defence-associated phenotype in plants and the gene expression in the insect herbivore should covary between low-and high-elevation environments. We found that L. corniculatus accumulated more CNglcs at high elevation, a result in agreement with the optimal defence theory. By contrast, we found that the levels of expression in the defence genes of Z. filipendulae larvae were not related to the CNglc content of their host plant. Overall, expression levels were not correlated with elevation either, with the exception of the UGT33A1 gene, which showed a marginally significant trend towards higher expression at high elevation when using a simple statistical framework. These results suggest that the defence phenotype of plants against herbivores, and subsequent herbivore sequestration machineries and de novo production, are based on a complex network of interactions.
  • Wu, Chen; Twort, Victoria G; Newcomb, Richard D; Buckley, Thomas R (2021)
    Some animal groups, such as stick insects (Phasmatodea), have repeatedly evolved alternative reproductive strategies, including parthenogenesis. Genomic studies have found modification of the genes underlying meiosis exists in some of these animals. Here we examine the evolution of copy number, evolutionary rate, and gene expression in candidate meiotic genes of the New Zealand geographic parthenogenetic stick insect Clitarchus hookeri. We characterized 101 genes from a de novo transcriptome assembly from female and male gonads that have homology with meiotic genes from other arthropods. For each gene we determined copy number, the pattern of gene duplication relative to other arthropod orthologs, and the potential for meiosis-specific expression. There are five genes duplicated in C hookers; including one also duplicated in the stick insect Timema cristinae, that are not or are uncommonly duplicated in other arthropods. These included two sister chromatid cohesion associated genes (SA2 and SCC2), a recombination gene (HOPI), an RNA-silencing gene (AGO2) and a cell-cycle regulation gene (WEE1). Interestingly, WEE1 and SA2 are also duplicated in the cyclical parthenogenetic aphid Acyrthosiphon pisum and Daphnia duplex, respectively, indicating possible roles in the evolution of reproductive mode. Three of these genes (SA2, SCC2, and WEE1) have one copy displaying gonad-specific expression. All genes, with the exception of WEE1, have significantly different nonsynonymous/synonymous ratios between the gene duplicates, indicative of a shift in evolutionary constraints following duplication. These results suggest that stick insects may have evolved genes with novel functions in gamete production by gene duplication.
  • Jernström, Sandra; Hongisto, Vesa; Leivonen, Suvi-Katri; Due, Eldri Undlien; Tadele, Dagim Shiferaw; Edgren, Henrik; Kallioniemi, Olli; Perälä, Merja; Mlandsmo, Gunhild Mari; Sahlberg, Kristine Kleivi (2017)
    Background: Approximately 15%-20% of all diagnosed breast cancers are characterized by amplified and overexpressed HER2 (= ErbB2). These breast cancers are aggressive and have a poor prognosis. Although improvements in treatment have been achieved after the introduction of trastuzumab and lapatinib, many patients do not benefit from these drugs. Therefore, in-depth understanding of the mechanisms behind the treatment responses is essential to find alternative therapeutic strategies. Materials and methods: Thirteen HER2 positive breast cancer cell lines were screened with 22 commercially available compounds, mainly targeting proteins in the ErbB2-signaling pathway, and molecular mechanisms related to treatment sensitivity were sought. Cell viability was measured, and treatment responses between the cell lines were compared. To search for response predictors and genomic and transcriptomic profiling, PIK3CA mutations and PTEN status were explored and molecular features associated with drug sensitivity sought. Results: The cell lines were divided into three groups according to the growth-retarding effect induced by trastuzumab and lapatinib. Interestingly, two cell lines insensitive to trastuzumab (KPL4 and SUM190PT) showed sensitivity to an Akt1/2 kinase inhibitor. These cell lines had mutation in PIK3CA and loss of PTEN, suggesting an activated and druggable Akt-signaling pathway. Expression levels of five genes (CDC42, MAPK8, PLCG1, PTK6, and PAK6) were suggested as predictors for the Akt1/2 kinase-inhibitor response. Conclusion: Targeting the Akt-signaling pathway shows promise in cell lines that do not respond to trastuzumab. In addition, our results indicate that several molecular features determine the growth-retarding effects induced by the drugs, suggesting that parameters other than HER2 amplification/expression should be included as markers for therapy decisions.
  • Veltsos, Paris; Ridout, Kate E.; Toups, Melissa A.; Gonzalez-Martinez, Santiago C.; Muyle, Aline; Emery, Olivier; Rastas, Pasi; Hudzieczek, Vojtech; Hobza, Roman; Vyskot, Boris; Marais, Gabriel A. B.; Filatov, Dmitry A.; Pannell, John R. (2019)
    Suppressed recombination allows divergence between homologous sex chromosomes and the functionality of their genes. Here, we reveal patterns of the earliest stages of sex-chromosome evolution in the diploid dioecious herb Mercurialis annua on the basis of cytological analysis, de novo genome assembly and annotation, genetic mapping, exome resequencing of natural populations, and transcriptome analysis. The genome assembly contained 34,105 expressed genes, of which 10,076 were assigned to linkage groups. Genetic mapping and exome resequencing of individuals across the species range both identified the largest linkage group, LG1, as the sex chromosome. Although the sex chromosomes of M. annua are karyotypically homomorphic, we estimate that about one-third of the Y chromosome, containing 568 transcripts and spanning 22.3 cM in the corresponding female map, has ceased recombining. Nevertheless, we found limited evidence for Y-chromosome degeneration in terms of gene loss and pseudogenization, and most X- and Y-linked genes appear to have diverged in the period subsequent to speciation between M. annua and its sister species M. huetii, which shares the same sex-determining region. Taken together, our results suggest that the M. annua Y chromosome has at least two evolutionary strata: a small old stratum shared with M. huetii, and a more recent larger stratum that is probably unique to M. annua and that stopped recombining similar to 1 MYA. Patterns of gene expression within the nonrecombining region are consistent with the idea that sexually antagonistic selection may have played a role in favoring suppressed recombination.
  • Gao, Jianguo (Helsingfors universitet, 2017)
    Obesity and insulin resistance (IR) are key factors lead to equine metabolic syndrome and laminitis. Diet may play an important role in eliciting obesity by affecting insulin dynamics. Insulin-pathway signaling and mTORC1 genes may contribute to incred IR. The first objective of this study was to find and validate internal control genes for quantitative PCR method for adipose tissues in Finnhorse mares. The second aim was to quantitate the expression of mTORC1 and insulin-pathway associated genes after pasture season in two different treatment groups of Finnhorse mares and compare gene expression differences between treatment groups. In addition, gene expression differences were compared between two different adipose tissues. Twenty-two mares were equally divided into eleven equal pairs, the two mares of each group were randomly grazed either on cultivated high-yielding pasture (CG) or on semi-natural grassland (NG) from the end of May to the beginning of September. Eight pairs of Finnhorse mares were selected for gene expression profiling. Subcutaneous adipose tissue (SAT) samples were collected from two groups of Finnhorse mares after pasture season. Gene expression of neck and tailhead SAT were determined with quantitative Real-Time PCR method (qPCR). The selected internal control genes were actin beta (ACTB), glucuronidase beta (GUSB) and mitochondrial ribosomal protein L39 (MRPL39). Candidate genes were mechanistic target of rapamycin (MTOR), sterol regulatory element binding transcription factor 1 (SREBF1), sterol regulatory element binding transcription factor 2 (SREBF2), TBC1 domain family member 7 (TBC1D7), leptin (LEP), glucose transporter type 4 (GLUT4), monocyte chemoattractant protein-1 (MCP-1), retinol binding protein 4 (RBP4), tuberous sclerosis 1 (TSC1), tuberous sclerosis 2 (TSC2). There were no distinct gene expression differences between NG and CG groups in both neck and tailhead SAT. However, RBP4 had significantly (P=0.035) higher and GLUT4 had a trend (P=0.064) to higher mRNA expression in CG group in neck SAT. TSC1 had a trend (P=0.071) of higher expression in CG group in tailhead SAT. Gene expression differences were observed between tailhead and neck SAT. SREBF1 and GLUT4 had significantly (P=0.007 and P=0.026, respectively) higher expression levels in tailhead SAT compared to neck SAT. RBP4 had a trend (P=0.066) to higher expression in neck SAT compared to tailhead SAT. Minor differences in gene expression between NG and CG groups indicate that pasture-associated fat depositionmaynotconsiderably affect expressionof insulin-pathway and mTORC1 genes associated to obesity and IR in studied subcutaneous adipose tissues. These results also provide additional evidence to our hypothesis that fattening resulting on unrestricted grazing on cultivated high-yielding pasture does not increase the risk of metabolic diseases in Finnhorse mares when they have normal body condition at the beginning of the grazing season.
  • Fagerstedt, K.W.; Salonen, T.; Zhao, F.; Kytölä, S.; Böhling, T.; Andersson, L.C. (2018)
    Myxoinflammatory fibroblastic sarcoma is a soft-tissue neoplasm most frequently found in the distal extremities of middle-aged adults. Most myxoinflammatory fibroblastic sarcoma are low-grade tumors with propensity for local recurrence after incomplete removal. We report a myxoinflammatory fibroblastic sarcoma which developed in the foot of a 41-year-old male and showed an exceptionally aggressive course with metastatic spread and fatal outcome within 16 months. We managed to establish a spontaneously transformed continuous cell line, called JU-PI, from a metastatic lesion. The JU-PI cells have a sub-tetraploid karyotype including the 1;10 chromosomal translocation and amplification of the proximal end of 3p; these features are considered genetic signatures of myxoinflammatory fibroblastic sarcoma. Both the primary tumor and the JU-PI cells showed nuclear expression of the TFE3 transcription factor but TFE3-activating chromosomal rearrangements were not found. To our knowledge, JU-PI is the first established myxoinflammatory fibroblastic sarcoma cell line. JU-PI cells offer a tool for investigating the molecular oncology of myxoinflammatory fibroblastic sarcoma. © 2018, © The Author(s) 2018.
  • Baral, Bikash (Helsingin yliopisto, 2015)
    Phytopathogens, notably Heterobasidion annosum, evolved several strategical combinations to infect and subsequently colonize their host even under different stress conditions. Fungal ABC transporters are well-known defenses that can confer resistance against host-secreted secondary metabolites by transporting them outside of the fungal cells and thus keeping their intracellular concentration low. Here, we aim to unveil the evolutionary trajectories of total ABC transporters-encoding genes in Heterobasidion annosum. The gene expression pattern was monitored with the fungus subjected to different chemical stressors and during fungal growth on wood. We identified 32 putative ABC protein-encoding genes in the Heterobasidion genome. Altogether 20 putative ABC transporter-encoding genes of H. annosum were further analyzed and it was revealed that several genes were either up or downregulated, while some were not differentially expressed under the experimental conditions. The results obtained from the gene expression analysis revealed that an ABC gene (annotated as Ha.ABC-G1 or Hetan_66124), was highly up-regulated in most conditions. This particular transporter-encoding gene (Hetan_66124) with induction level of up to 47 –fold (in heartwood and similar levels in other conditions) was traced, PCR amplified, cloned in Escherichia coli and expression of recombinant protein performed using Saccharomyces cerevisiae as platform. Several experiments aiming to dissect functional roles of this hypothetical protein were performed. The growth of the yeast transformant over expressing the recombinant ABC protein in different terpenoids and weak organic acids were monitored. The growth rate of clones with and without transporters were not significantly different when cultured in plates (SC·gal-ura-) that were exposed to the volatile compounds (limonene, carene and ?-pinene). Based on our findings, we concluded that the yeast transformants carrying the H. annosum ABC-G1 transporter encoding gene do not show increased resistance or tolerance against the monoterpenes. The results of the transcript profiling have further contributed to our understanding about gene expression during fungal colonization upon exposure to chemical stressors. However, further studies are needed in order to specifically unveil the functional roles of these efflux pumps that underlie their transport mechanism with response to the host secreted secondary metabolites.
  • Woestmann, Luisa; Kvist, Jouni Antero; Saastamoinen, Marjo Anna Kaarina (2017)
    Flight represents a key trait in most insects, being energetically extremely demanding, yet often necessary for foraging and reproduction. Additionally, dispersal via flight is especially important for species living in fragmented landscapes. Even though, based on life-history theory, a negative relationship may be expected between flight and immunity, a number of previous studies have indicated flight to induce an increased immune response. In this study, we assessed whether induced immunity (i.e. immune gene expression) in response to 15-min forced flight treatment impacts individual survival of bacterial infection in the Glanville fritillary butterfly (Melitaea cinxia). We were able to confirm previous findings of flight-induced immune gene expression, but still observed substantially stronger effects on both gene expression levels and life span due to bacterial infection compared to flight treatment. Even though gene expression levels of some immunity-related genes were elevated due to flight, these individuals did not show increased survival of bacterial infection, indicating that flight-induced immune activation does not completely protect them from the negative effects of bacterial infection. Finally, an interaction between flight and immune treatment indicated a potential trade-off: flight treatment increased immune gene expression in naive individuals only, whereas in infected individuals no increase in immune gene expression was induced by flight. Our results suggest that the up-regulation of immune genes upon flight is based on a general stress response rather than reflecting an adaptive response to cope with potential infections during flight or in new habitats.