Beckwith-Wiedemann Syndrome (BWS) is an imprinting disorder characterized by overgrowth, stemming from various genetic and epigenetic changes. This study delves into the role of
upregulation in BWS, ...focusing on insulin-like growth factor pathways, which are poorly known in this syndrome. We examined the IGF2R, the primary receptor of IGF2, WNT, and autophagy/lysosomal pathways in BWS patient-derived lymphoblastoid cell lines, showing different genetic and epigenetic defects. The findings reveal a decreased expression and mislocalization of IGF2R protein, suggesting receptor dysfunction. Additionally, our results point to a dysregulation in the AKT/GSK-3/mTOR pathway, along with imbalances in autophagy and the WNT pathway. In conclusion, BWS cells, regardless of the genetic/epigenetic profiles, are characterized by alteration of the IGF2R pathway that is associated with the perturbation of the autophagy and lysosome processes. These alterations seem to be a key point of the molecular pathogenesis of BWS and potentially contribute to BWS's characteristic overgrowth and cancer susceptibility. Our study also uncovers alterations in the WNT pathway across all BWS cell lines, consistent with its role in growth regulation and cancer development.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Cutaneous lesions are one of the hallmarks of tuberous sclerosis complex (TSC), a genetic disease in which mTOR is hyperactivated due to the lack of hamartin or tuberin. To date, novel ...pharmacological treatments for TSC cutaneous lesions that are benign but still have an impact on a patient's life are needed, because neither surgery nor rapamycin administration prevents their recurrence. Here, we demonstrated that primary TSC2
cells that do not express tuberin for an epigenetic event caused cutaneous lesions and follicular neogenesis when they were subcutaneously injected in nude mice. Tuberin-null cells localized in the hair bulbs and alongside mature hairs, where high phosphorylation of S6 and Erk indicated mTOR hyperactivation. Interestingly, 5-azacytidine treatment reduced hair follicles, indicating that chromatin remodeling agents might be effective on TSC lesions in which cells lack tuberin for an epigenetic event. Moreover, we demonstrated that the primary TSC2
cells had metastatic capability: when subcutaneously injected, they reached the bloodstream and lymphatics and invaded the lungs, causing the enlargement of the alveolar walls. The capability of TSC2
cells to survive and migrate in vivo makes our mouse model ideal to follow the progression of the disease and test potential pharmacological treatments in a time-dependent manner.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Recent advancements in reproductive medicine have guided novel strategies for addressing male infertility, particularly in cases of non-obstructive azoospermia (NOA). Two prominent invasive ...interventions, namely testicular sperm extraction (TESE) and microdissection TESE (micro-TESE), have emerged as key techniques to retrieve gametes for assisted reproduction technologies (ART). Both heterogeneity and complexity of NOA pose a multifaceted challenge to clinicians, as the invasiveness of these procedures and their unpredictable success underscore the need for more precise guidance. Seminal plasma can be aptly regarded as a liquid biopsy of the male reproductive tract, encompassing secretions from the testes, epididymides, seminal vesicles, bulbourethral glands, and prostate. This fluid harbors a variety of cell-free nucleic acids, microvesicles, proteins, and metabolites intricately linked to gonadal activity. However, despite numerous investigations exploring potential biomarkers from seminal fluid, their widespread inclusion into the clinical practice remains limited. This could be partially due to the complex interplay of diverse clinical and genetic factors inherent to NOA that likely contributes to the absence of definitive biomarkers for residual spermatogenesis. It is conceivable that the integration of clinical data with biomarkers could increase the potential in predicting surgical procedure outcomes and their choice in NOA cases. This comprehensive review addresses the challenge of sperm retrieval in NOA through non-invasive biomarkers. Moreover, we delve into promising perspectives, elucidating innovative approaches grounded in multi-omics methodologies, including genomics, transcriptomics and proteomics. These cutting-edge techniques, combined with the clinical and genetics features of patients, could improve the use of biomarkers in personalized medical approaches, patient counseling, and the decision-making continuum. Finally, Artificial intelligence (AI) holds significant potential in the realm of combining biomarkers and clinical data, also in the context of identifying non-invasive biomarkers for sperm retrieval.
Beckwith-Wiedemann syndrome (BWS) and Silver-Russell syndrome (SRS) are imprinting-related disorders associated with genetic/epigenetic alterations of the 11p15.5 region, which harbours two clusters ...of imprinted genes (IGs). 11p15.5 IGs are regulated by the methylation status of imprinting control regions ICR1 and ICR2. 3D chromatin structure is thought to play a pivotal role in gene expression control; however, chromatin architecture models are still poorly defined in most cases, particularly for IGs. Our study aimed at elucidating 11p15.5 3D structure, via 3C and 3D FISH analyses of cell lines derived from healthy, BWS or SRS children. We found that, in healthy cells, IGF2/H19 and CDKN1C/KCNQ1OT1 domains fold in complex chromatin conformations, that facilitate the control of IGs mediated by distant enhancers. In patient-derived cell lines, we observed a profound impairment of such a chromatin architecture. Specifically, we identified a cross-talk between IGF2/H19 and CDKN1C/KCNQ1OT1 domains, consisting in in cis, monoallelic interactions, that are present in healthy cells but lost in patient cell lines: an inter-domain association that sees ICR2 move close to IGF2 on one allele, and to H19 on the other. Moreover, an intra-domain association within the CDKN1C/KCNQ1OT1 locus seems to be crucial for maintaining the 3D organization of the region.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
DNA methylation in the human genome is largely programmed and shaped by transcription factor binding and interaction between DNA methyltransferases and histone marks during gamete and embryo ...development. Normal methylation profiles can be modified at single or multiple loci, more frequently as consequences of genetic variants acting in cis or in trans, or in some cases stochastically or through interaction with environmental factors. For many developmental disorders, specific methylation patterns or signatures can be detected in blood DNA. The recent use of high-throughput assays investigating the whole genome has largely increased the number of diseases for which DNA methylation analysis provides information for their diagnosis. Here, we review the methylation abnormalities that have been associated with mono/oligogenic diseases, their relationship with genotype and phenotype and relevance for diagnosis, as well as the limitations in their use and interpretation of results.
The role of epigenetics in the modulation of longevity has not been studied in humans. To this aim, (1) we evaluated the DNA methylation from peripheral leukocytes of 21 female centenarians, their 21 ...female offspring, 21 offspring of both non-long-lived parents, and 21 young women through ELISA assay, pyrosequencing analysis of Alu sequences, and quantification of methylation in CpG repeats outside CpG islands; (2) we compared the DNA methylation profiles of these populations through Infinium array for genome-wide CpG methylation analysis. We observed an age-related decrease in global DNA methylation and a delay of this process in centenarians’ offspring. Interestingly, literature data suggest a link between the loss of DNA methylation observed during aging and the development of age-associated diseases. Genome-wide methylation analysis evidenced DNA methylation profiles specific for aging and longevity: (1) aging-associated DNA hypermethylation occurs predominantly in genes involved in the development of anatomical structures, organs, and multicellular organisms and in the regulation of transcription; (2) genes involved in nucleotide biosynthesis, metabolism, and control of signal transmission are differently methylated between centenarians’ offspring and offspring of both non-long-lived parents, hypothesizing a role for these genes in human longevity. Our results suggest that a better preservation of DNA methylation status, a slower cell growing/metabolism, and a better control in signal transmission through epigenetic mechanisms may be involved in the process of human longevity. These data fit well with the observations related to the beneficial effects of mild hypothyroidism and insulin-like growth factor I system impairment on the modulation of human lifespan.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK, VSZLJ
A role of X chromosome inactivation process in the development of breast cancer have been suggested. In particular, the relationship between the breast cancer predisposing gene BRCA1 and XIST, the ...main mediator of X chromosome inactivation, has been intensely investigated, but still remains controversial. We investigated this topic by assessing XIST behaviour in different groups of breast carcinomas and in a panel of breast cancer cell lines both BRCA1 mutant and wild type. In addition, we evaluated the occurrence of broader defects of heterochromatin in relation to BRCA1 status in breast cancer cells. We provide evidence that in breast cancer cells BRCA1 is involved in XIST regulation on the active X chromosome, but not in its localization as previously suggested, and that XIST can be unusually expressed by an active X and can decorate it. This indicates that the detection of XIST cloud in cancer cell is not synonymous of the presence of an inactive X chromosome. Moreover, we show that global heterochromatin defects observed in breast tumor cells are independent of BRCA1 status. Our observations sheds light on a possible previously uncharacterized mechanism of breast carcinogenesis mediated by XIST misbehaviour, particularly in BRCA1-related cancers. Moreover, the significant higher levels of XIST-RNA detected in BRCA1-associated respect to sporadic basal-like cancers, opens the possibility to use XIST expression as a marker to discriminate between the two groups of tumors.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Genomic imprinting, resulting in parent-of-origin-dependent gene expression, is mainly achieved by DNA methylation. IGF2 and H19, belonging to the same cluster of imprinted genes and regulated by ...ICR1, DMR2 and H19 promoter elements, play a major role in fetal/placental growth. Using quantitative approaches, we explored the epigenetic modulation of IGF2/H19 during human development in 60 normal and 66 idiopathic IUGR (Intrauterine Growth Restriction) pregnancies, studying embryonic (cord blood) and extraembryonic (placenta and umbilical cord) tissues. We found ICR1 normal methylation levels (~50%) and H19 promoter/DMR2 hypomethylation in extra-embryonic tissues. In contrast, in embryonic samples the three loci displayed normal methylation values comparable to those in postnatal blood. This feature is stably maintained throughout gestation and does not vary in IUGR cases. We reported asymmetric allelic expression of H19 and IGF2 as a common feature in pre- and post-natal tissues, independent of H19 promoter and DMR2 methylation levels. In addition, we excluded in IUGR posttranscriptional IGF2 interference possibly related to miRNA 483-3p (IGF2, intron 2) expression defects. Through LINE1 methylation analysis, we observed a methylation gradient with increasing methylation from pre- to post-natal life. The involvement of UPD (Uniparental Disomy) in IUGR aetiology was excluded. Our data indicate that: i) ICR1 3 methylation status is a necessary and sufficient condition to drive the imprinting of IGF2 and H19 present in embryonic as well as in extra-embryonic tissues; ii) hypomethylation of H19 promoter and DMR2 does not influence the expression pattern of IGF2 and H19; iii) there is a gradient of global methylation, increasing from extra-embryonic to embryonic and adult tissues. Finally, because of placental hypomethylation, cautions should be exercised in diagnosis of imprinting diseases using chorionic villi.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
X‐linked intellectual disability (XLID) refers to a clinically and genetically heterogeneous neurodevelopmental disorder, in which males are more heavily affected than females. Among the syndromic ...forms of XLID, identified by additional clinical signs as part of the disease spectrum, the association between XLID and severe myopia has been poorly characterized. We used whole exome sequencing (WES) to study two Italian male twins presenting impaired intellectual function and adaptive behavior, in association with severe myopia and mild facial dysmorphisms. WES analysis detected the novel, maternally inherited, mutation c.916G > C (G306R) in the X‐linked heparan sulfate 6‐O‐sulfotransferase 2 (HS6ST2) gene. HS6ST2 transfers sulfate from adenosine 3′‐phosphate, 5′‐phosphosulfate to the sixth position of the N‐sulphoglucosamine residue in heparan sulfate (HS) proteoglycans. Low HS sulfation levels are associated with defective optic disc and stalk morphogenesis during mammalian visual system development. The c.916G>C variant affects the HS6ST2 substrate binding site, and its effect was considered “deleterious” by in‐silico tools. An in‐vitro enzymatic assay showed that the HS6ST2 mutant isoform had significantly reduced sulphotransferase activity. Taken together, the results suggest that mutant HS6ST2 is possibly involved in the development of myopia and cognitive impairment, characteristics of the probands reported here.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
STUDY QUESTION
Is the presence of ESX1 mRNA in seminal fluid (SF) an indicator of residual spermatogenesis in men with non-obstructive azoospermic (NOA)?
SUMMARY ANSWER
ESX1 mRNA in SF is a suitable ...molecular marker for predicting the presence of residual spermatogenesis in testis.
WHAT IS KNOWN ALREADY
ESX1 is an X-linked homeobox gene whose expression in testis is restricted to germ cells. We previously reported, in the testicular biopsies from azoospermic men, a positive correlation between the presence of ESX1 mRNA and residual spermatogenesis.
STUDY DESIGN, SIZE, DURATION
We investigated ESX1 mRNA expression in 70 testicular fragments (TF) and 56 (SF) of 70 NOA men. As controls, we analyzed 8 TF from men with obstructive azoospermic (OA) and 9 SF from normozoospermic men. For all patients we considered the histological classification of testis biopsies and the recovery of spermatozoa by surgical procedures.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Relative ESX1 mRNA expression was evaluated by quantitative RT–PCR using the ΔΔCt method. The results were compared with the recovery of spermatozoa at surgery.
MAIN RESULTS AND THE ROLE OF CHANCE
In TF from NOA patients we found that: (i) ESX1 mRNA level was significantly decreased as the severity of spermatogenic defects increased (P < 0.0001, one-way analysis of variance); (ii) the presence of ESX1 mRNA can predict the success of sperm retrieval (sensitivity: 80%). In SF from NOA patients we found that: (i) ESX1 mRNA was present in 78.5% of NOA men; (ii) the presence of ESX1 mRNA could predict the success of sperm retrieval (sensitivity: 84%).
LIMITATIONS, REASONS FOR CAUTION
Spermatozoa were recovered at surgery in 5 out of 12 patients whose SF was negative for ESX1 mRNA expression. We think that discrepancies between molecular and clinical results could be reduced by analyzing more than one ejaculate from each man.
WIDER IMPLICATIONS OF THE FINDINGS
The data confirm that the ESX1 transcript in the semen of men with NOA is a suitable molecular marker for predicting the presence of residual foci of spermatogenesis in the testis. The implication of these results is that some patients ‘with azoospermia’, although having a severe impairment of spermatogenesis, could still maintain residual foci of spermatogenesis in limited areas of the testes, not always recovered by surgery.
STUDY FUNDING/COMPETING INTEREST(S)
This work was supported by the Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico: Ricerca Corrente grant number RC2014/519-02 to M.M. and from ASM onlus 2010–2011 to M.M. The authors declare that they have no conflict of interest.
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