MED12 mutations and metabolomic changes in uterine leiomyomas

Uterine leiomyomas are benign smooth muscle tumors that affect nearly 70% of Caucasian women and over 80% of African American women by age 50. As leiomyomas impair the quality of life in a large proportion of women, these tumors pose a significant health and economic impact. Leiomyomas are heterogeneous in their number, size, location, growth rate, histological features, and clinical presentation, as well as in their molecular characteristics. Multiple distinct genetic alterations lead to the development of these tumors, including chromosomal rearrangements affecting high mobility group AT-hook 2 (HMGA2), biallelic inactivation of fumarate hydratase (FH), and mutations in mediator complex subunit 12 (MED12). This thesis aimed to study the occurrence and characteristics of MED12-mutation-positive and -negative uterine leiomyomas, and to elucidate the metabolomic profiles of leiomyomas harboring distinct genetic drivers. This work validated the occurrence of MED12 mutations in uterine leiomyomas derived from South African women, and demonstrated that these mutations are the main genetic driver of leiomyomas regardless of ethnicity. Our results showed that when small leiomyomas are also examined, the mutation frequency is as high as 86%, and in the largest leiomyoma series thus far with carefully controlled size bias, the mutation frequency was 79%. We discovered that MED12 mutations are associated with smaller size, subserosal location, conventional histology, and larger number of leiomyomas. In addition, the number of mutation-positive leiomyomas was inversely associated with parity, and the number of mutation-negative leiomyomas was associated with a history of pelvic inflammatory disease. These findings demonstrate the extremely high MED12-mutation frequency and their contribution to the observed heterogeneity of uterine leiomyomas. Global metabolomic profiling of uterine leiomyoma and corresponding myometrium samples revealed that the three main genetic drivers result in differences in metabolic profiles; in particular, FH-deficient leiomyomas were distinguishable based on their unique profile. We observed shared metabolic changes for all leiomyomas and distinctive alterations for FH-deficient and MED12-mutation-positive leiomyomas. The dysregulated metabolites identified may prove to be useful biomarkers or targets for prevention and treatment of leiomyomas. This thesis highlights the role of MED12 mutations and metabolomic alterations in leiomyomas, further emphasizing the importance of molecular classification of leiomyomas in research, and possibly in clinical practice as well when targeted treatment options emerge.Kohdun myoomat ovat hyvin yleisiä hyvänlaatuisia sileälihaskasvaimia, jotka aiheuttavat terveydellistä haittaa suurelle osalle naisista johtaen huomattaviin taloudellisiin kustannuksiin. Myoomien lukumäärä, koko, sijainti, kasvutaipumus, niiden aiheuttamat oireet ja histologiset sekä molekulaariset piirteet vaihtelevat merkittävästi eri potilaiden välillä. Usean eri geenin toiminnan häriintyminen, kuten HMGA2-geenin yli-ilmentyminen ja FH-geenin toiminnan puute, voi johtaa myoomien syntyyn. Lisäksi äskettäin todettiin, että valtaosa myoomista kehittyy MED12-geenin mutaatioiden myötä. Tämän väitöskirjatyön tarkoituksena oli tutkia MED12-geenin mutaatioiden myötä syntyneiden myoomien yleisyyttä ja erityispiirteitä sekä tutkia aineenvaihdunnan muutoksia myoomissa, jotka ovat syntyneet eri geenivirheiden aiheuttamina. Tässä tutkimuskokonaisuudessa osoitimme MED12-geenin mutaatioiden olevan yleisiä myös eteläafrikkalaisten naisten myoomissa, mikä vahvistaa ajatusta siitä, että nämä mutaatiot aiheuttavat valtaosan myoomista potilaiden etnisestä alkuperästä riippumatta. Tulokset havainnollistivat MED12-geenin mutaatioita olevan jopa 86 %:ssa myoomista, kun myös pienikokoiset myoomat sisällytetään analyyseihin, ja lisäksi tähän mennessä suurimmassa myoomanäytesarjassa mutaatioita havaittiin 79 %:ssa myoomista. Lisäksi osoitimme MED12-geenin mutaatioiden olevan yhteydessä myoomien kokoon, lukumäärään, sijaintiin, ja histologisiin piirteisiin sekä potilaiden synnytysten lukumäärään. MED12-mutaationegatiivisisten myoomien lukumäärä oli sen sijaan sidoksissa potilaiden aiempaan kohtutulehdukseen. Nämä tulokset vahvistavat MED12-geenin mutaatioiden yleisyyden sekä mutaatioiden myötävaikutuksen myoomien piirteiden vaihtelussa. Myoomien ja kohdun terveen sileälihaskudoksen aineenvaihduntatutkimus osoitti eri geenivirheiden johtavan eroihin kasvainten aineenvaihdunnassa. Havaitsimme eritoten FH-geenin muutosten aiheuttavan kasvaimiin hyvinkin erilaisen aineenvaihduntaprofiilin verrattuna muihin tutkittuihin näytteisiin. Tunnistimme useita aineenvaihdunnallisia muutoksia, jotka olivat yhteisiä kaikille myoomille, sekä muutoksia, jotka erottivat FH- ja MED12-geenivirheiset myoomat toisistaan. Tässä työssä tunnistettuja aineenvaihduntareittejä sekä –tuotteita voidaan hyödyntää myoomien seulonta-, ehkäisy- ja hoitomenetelmien kehittämisessä. Tämä työ korostaa MED12-geenin geenivirheiden sekä aineenvaihduntamuutosten merkitystä myoomien synnyssä ja painottaa myoomien molekyyligeneettisen luokittelun tärkeyttä myoomatutkimuksessa sekä mahdollisesti tulevaisuudessa yksilöityjen hoitomuotojen kehittyessä myös potilaiden hoidossa

Multiple clinical characteristics separate MED12-mutation-positive and -negative uterine leiomyomas

Up to 86% of uterine leiomyomas harbour somatic mutations in mediator complex subunit 12 (MED12). These mutations have been associated with conventional histology, smaller tumour size, and larger number of tumours within the uterus. Prior studies, with limited sample sizes, have failed to detect associations between other clinical features and MED12 mutations. Here, we prospectively collected 763 uterine leiomyomas and the corresponding normal myometrial tissue from 244 hysterectomy patients, recorded tumour characteristics, collected clinical data from medical records, and screened the tissue samples for MED12 mutations to assess potential associations between clinical variables and mutation status. Out of 763 leiomyomas, 599 (79%) harboured a MED12 mutation. In the analysis of tumour characteristics, positive MED12-mutation status was significantly associated with smaller tumour size, conventional histology, and subserous location, relative to intramural. In the analysis of clinical variables, the number of MED12-mutation-positive tumours showed an inverse association with parity, and the number of mutation-negative tumours showed a positive association with a history of pelvic inflammatory disease. This study confirmed the previously reported differences and discovered novel differentiating features for MED12-mutation-positive and -negative leiomyomas. These findings emphasise the relevance of specific driver mutations in genesis and presentation of uterine leiomyomas.Peer reviewe

Nutrition after preterm birth and adult neurocognitive outcomes

Background Preterm birth ( Methods In 86 participants of the Helsinki Study of Very Low Birth Weight Adults (birthweight <1500g), we examined if higher intakes of energy, macronutrients, and human milk during the first nine weeks after preterm birth predict performance in tests of cognitive ability at 25.1 years of age (SD = 2.1). Results 10 kcal/kg/day higher total energy intake at 3 to 6 weeks of age was associated with 0.21 SD higher adult IQ (95% Confidence Interval [CI] 0.07-0.35). Higher carbohydrate and fat intake at 3-6 weeks, and higher energy intake from human milk at 3-6 and at 6-9 weeks were also associated with higher adult IQ: these effect sizes ranged from 0.09 SD (95% CI 0.01-0.18) to 0.34 SD (0.14-0.54) higher IQ, per one gram/kg/day more carbohydrate and fat, and per 10 kcal/kg/day more energy from human milk. Adjustment for neonatal complications attenuated the associations: intraventricular hemorrhage, in particular, was associated with both poorer nutrition and poorer IQ. Conclusion In preterm neonates with very low birth weight, higher energy and human milk intake predict better neurocognitive abilities in adulthood. To understand the determinants of these infants' neurocognitive outcome, it seems important to take into account the role of postnatal nutrition, not just as an isolated exposure, but as a potential mediator between neonatal illness and long-term neurodevelopment.Peer reviewe

Genetic predisposition to uterine leiomyoma is determined by loci for genitourinary development and genome stability

Uterine leiomyomas (ULs) are benign tumors that are a major burden to women's health. A genome-wide association study on 15,453 UL cases and 392,628 controls was performed, followed by replication of the genomic risk in six cohorts. Effects of the risk alleles were evaluated in view of molecular and clinical characteristics. 22 loci displayed a genome-wide significant association. The likely predisposition genes could be grouped to two biological processes. Genes involved in genome stability were represented by TERT, TERC, OBFC1 - highlighting the role of telomere maintenance - TP53 and ATM. Genes involved in genitourinary development, WNT4, WT1, SALL1, MED12, ESR1, GREB1, FOXO1, DMRT1 and uterine stem cell marker antigen CD44, formed another strong subgroup. The combined risk contributed by the 22 loci was associated with MED12 mutation-positive tumors. The findings link genes for uterine development and genetic stability to leiomyomagenesis, and in part explain the more frequent occurrence of UL in women of African origin.Peer reviewe

Early life origins cognitive decline: findings in elderly men in the helsinki birth cohort study.

OBJECTIVES: To examine whether the adverse effects of slow prenatal and postnatal growth on cognitive function persist to old age and predict age related cognitive decline. DESIGN AND SETTING: A longitudinal birth cohort study of men born in Helsinki, Finland 1934-44. PARTICIPANTS: Nine-hundred-thirty-one men of the Helsinki Birth Cohort Study, with detailed data on growth from birth to adulthood, aged 20.1 (SD = 1.4) at the first and 67.9 (SD = 2.5) years at the second cognitive testing. MAIN OUTCOME MEASURES: The Finnish Defense Forces Basic Intellectual Ability Test assessed twice over nearly five decades apart. RESULTS: Lower weight, length and head circumference at birth were associated with lower cognitive ability at 67.9 years (1.04-1.55 points lower ability per each standard deviation [SD] unit decrease in body size, 95% Confidence Interval [95%CI]: 0.05 to 2.72) and with cognitive decline after 20.1 years (0.07-0.11 SD decline over time per each SD decrease in body size, 95%CI:0.00 to 0.19). Men who were born larger were more likely to perform better in the cognitive ability test over time (1.22-1.43 increase in odds to remain in the top relative to the lower two thirds in ability over time per each SD increase in body size, 95%CI:1.04 to 1.79) and were more resilient to cognitive decline after 20.1 years (0.69 to 0.76 decrease in odds to decline from than remain in the top third of ability over time per each SD increase in body size, 95%CI:0.49 to 0.99). Slower growth between birth and two years in weight, height and body mass index was associated with lower cognitive ability at 67.9 years, but not with cognitive decline. CONCLUSIONS: Poorer lifetime cognitive ability is predicted by slower growth before and after birth. In predicting resilience to age related cognitive decline, the period before birth seems to be more critical.Peer reviewe

Global metabolomic profiling of uterine leiomyomas

Background: Uterine leiomyomas can be classified into molecularly distinct subtypes according to their genetic triggers: MED12 mutations, HMGA2 upregulation, or inactivation of FH. The aim of this study was to identify metabolites and metabolic pathways that are dysregulated in different subtypes of leiomyomas. Methods: We performed global metabolomic profiling of 25 uterine leiomyomas and 17 corresponding myometrium specimens using liquid chromatography-tandem mass spectroscopy. Results: A total of 641 metabolites were detected. All leiomyomas displayed reduced homocarnosine and haeme metabolite levels. We identified a clearly distinct metabolomic profile for leiomyomas of the FH subtype, characterised by metabolic alterations in the tricarboxylic acid cycle and pentose phosphate pathways, and increased levels of multiple lipids and amino acids. Several metabolites were uniquely elevated in leiomyomas of the FH subtype, including N6-succinyladenosine and argininosuccinate, serving as potential biomarkers for FH deficiency. In contrast, leiomyomas of the MED12 subtype displayed reduced levels of vitamin A, multiple membrane lipids and amino acids, and dysregulation of vitamin C metabolism, a finding which was also compatible with gene expression data. Conclusions: The study reveals the metabolomic heterogeneity of leiomyomas and provides the requisite framework for strategies designed to target metabolic alterations promoting the growth of these prevalent tumours.Peer reviewe

Common Inflammation-Related Candidate Gene Variants and Acute Kidney Injury in 2647 Critically Ill Finnish Patients

Acute kidney injury (AKI) is a syndrome with high incidence among the critically ill. Because the clinical variables and currently used biomarkers have failed to predict the individual susceptibility to AKI, candidate gene variants for the trait have been studied. Studies about genetic predisposition to AKI have been mainly underpowered and of moderate quality. We report the association study of 27 genetic variants in a cohort of Finnish critically ill patients, focusing on the replication of associations detected with variants in genes related to inflammation, cell survival, or circulation. In this prospective, observational Finnish Acute Kidney Injury (FINNAKI) study, 2647 patients without chronic kidney disease were genotyped. We defined AKI according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria. We compared severe AKI (Stages 2 and 3, n = 625) to controls (Stage 0, n = 1582). For genotyping we used iPLEX(TM) Assay (Agena Bioscience). We performed the association analyses with PLINK software, using an additive genetic model in logistic regression. Despite the numerous, although contradictory, studies about association between polymorphisms rs1800629 in TNFA and rs1800896 in IL10 and AKI, we found no association (odds ratios 1.06 (95% CI 0.89-1.28, p = 0.51) and 0.92 (95% CI 0.80-1.05, p = 0.20), respectively). Adjusting for confounders did not change the results. To conclude, we could not confirm the associations reported in previous studies in a cohort of critically ill patients.Peer reviewe

Heme oxygenase-1 repeat polymorphism in septic acute kidney injury

Acute kidney injury (AKI) is a syndrome that frequently affects the critically ill. Recently, an increased number of dinucleotide repeats in the HMOX1 gene were reported to associate with development of AKI in cardiac surgery. We aimed to test the replicability of this finding in a Finnish cohort of critically ill septic patients. This multicenter study was part of the national FINNAKI study. We genotyped 300 patients with severe AKI (KDIGO 2 or 3) and 353 controls without AKI (KDIGO 0) for the guanine-thymine (GTn) repeat in the promoter region of the HMOX1 gene. The allele calling was based on the number of repeats, the cut off being 27 repeats in the S-L (short to long) classification, and 27 and 34 repeats for the S-M-L2 (short to medium to very long) classification. The plasma concentrations of heme oxygenase-1 (HO-1) enzyme were measured on admission. The allele distribution in our patients was similar to that published previously, with peaks at 23 and 30 repeats. The S-allele increases AKI risk. An adjusted OR was 1.30 for each S-allele in an additive genetic model (95% CI 1.01-1.66; p = 0.041). Alleles with a repeat number greater than 34 were significantly associated with lower HO-1 concentration (p<0.001). In septic patients, we report an association between a short repeat in HMOX1 and AKI risk