Imaging in gynecological disease (27): clinical and ultrasound characteristics of recurrent ovarian stromal cell tumors

OBJECTIVE

To describe the clinical and ultrasound characteristics of recurrent granulosa cell and Sertoli-Leydig cell tumors.

METHODS

This was a retrospective observational study performed at Fondazione Policlinico Universitario A. Gemelli, Istituto di Ricovero e Cura a Carattere Scientifico, IRCCS, Rome (Gemelli center), Italy. Patients with a histological diagnosis of recurrent granulosa cell tumor or Sertoli-Leydig cell tumor were identified from the database of the Department of Gynecological Oncology. Those who had undergone a preoperative ultrasound examination at the Gemelli center between 2012 and 2020 were included, and the data retrieved from the original ultrasound reports. In all of these reports, the recurrent tumors were described using International Ovarian Tumor Analysis (IOTA) terminology. If a patient had more than one episode of relapse, information from all episodes was collected. If there was more than one recurrent tumor at the same ultrasound examination, all tumors were included. One expert sonographer also reviewed all available ultrasound images to identify typical ultrasound patterns using pattern recognition.

RESULTS

We identified 30 patients with a histological diagnosis of recurrent granulosa cell tumor (25 patients, 55 tumors) or Sertoli-Leydig cell tumor (five patients, seven tumors). All 30 had undergone at least one preoperative ultrasound examination at the Gemelli center and were included. These women had a total of 66 episodes of relapse, of which a preoperative ultrasound examination had been performed at the Gemelli center in 34, revealing 62 recurrent lesions: one in 22/34 (64.7%) episodes of relapse, two in 4/34 (11.8%) episodes and three or more in 8/34 (23.5%) episodes. Most recurrent granulosa cell tumors (38/55, 69.1%) and recurrent Sertoli-Leydig tumors (6/7, 85.7%) were classified as solid or multilocular-solid tumors, while 8/55 (14.5%) recurrent granulosa cell tumors and 1/7 (14.3%) recurrent Sertoli-Leydig cell tumors were unilocular cysts and 9/55 (16.4%) recurrent granulosa cell tumors were multilocular cysts. The nine unilocular cysts had contents that were anechoic (n = 2) or had low-level echogenicity (n = 7), had either smooth (n = 4) or irregular (n = 5) internal cyst walls, and ranged in largest diameter from 8 to 38 mm, with three being < 20 mm and five being 20-30 mm. On retrospective review of the images, two typical ultrasound patterns were described: small solid tumor measuring < 2 cm (15/62, 24.2%) and tumor with vascularized echogenic ground-glass-like content (12/62, 19.4%).

CONCLUSIONS

Some granulosa cell and Sertoli-Leydig cell recurrences manifest one of two typical ultrasound patterns, while some appear as unilocular cysts. These are usually classified as benign, but in patients being followed up for a granulosa cell tumor or Sertoli-Leydig cell tumor, a unilocular cyst should be considered suspicious of recurrence. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

A cost-effectiveness analysis of an integrated clinical-radiogenomic screening program for the identification of BRCA 1/2 carriers (e-PROBE study)

Current approach to identify BRCA 1/2 carriers in the general population is ineffective as most of the carriers remain undiagnosed. Radiomics is an emerging tool for large scale quantitative analysis of features from standard diagnostic imaging and has been applied also to identify gene mutational status. The objective of this study was to evaluate the clinical and economic impact of integrating a radiogenomics model with clinical and family history data in identifying BRCA mutation carriers in the general population. This cost-effective analysis compares three different approaches to women selection for BRCA testing: established clinical criteria/family history (model 1); established clinical criteria/family history and the currently available radiogenomic model (49% sensitivity and 87% specificity) based on ultrasound images (model 2); same approach used in model 2 but simulating an improvement of the performances of the radiogenomic model (80% sensitivity and 95% specificity) (model 3). All models were trained with literature data. Direct costs were calculated according to the rates currently used in Italy. The analysis was performed simulating different scenarios on the generation of 18-year-old girls in Italy (274,000 people). The main outcome was to identify the most effective model comparing the number of years of BRCA-cancer healthy life expectancy (HLYs). An incremental cost-effectiveness ratio (ICER) was also derived to determine the cost in order to increase BRCA carriers-healthy life span by 1 year. Compared to model 1, model 2 increases the detection rate of BRCA carriers by 41.8%, reduces the rate of BRCA-related cancers by 23.7%, generating over a 62-year observation period a cost increase by 2.51 €/Year/Person. Moreover, model 3 further increases BRCA carriers detection (+ 68.3%) and decrease in BRCA-related cancers (- 38.4%) is observed compared to model 1. Model 3 increases costs by 0.7 €/Year/Person. After one generation, the estimated ICER in the general population amounts to about 3800€ and 653€ in model 2 and model 3 respectively. Model 2 has a massive effect after only one generation in detecting carriers in the general population with only a small cost increment. The clinical impact is limited mainly due to the current low acceptance rate of risk-reducing surgeries. Further multicentric studies are required before implementing the integrated clinical-radiogenomic model in clinical practice.

N-Acetylaspartate Drives Oligodendroglial Differentiation via Histone Deacetylase Activation

An unmet clinical goal in demyelinating pathologies is to restore the myelin sheath prior to neural degeneration. N-acetylaspartate (NAA) is an acetylated derivative form of aspartate, abundant in the healthy brain but severely reduced during traumatic brain injury and in patients with neurodegenerative pathologies. How extracellular NAA variations impact the remyelination process and, thereby, the ability of oligodendrocytes to remyelinate axons remains unexplored. Here, we evaluated the remyelination properties of the oligodendroglial (OL) mouse cell line Oli-neuM under different concentrations of NAA using a combination of biochemical, qPCR, immunofluorescence assays, and in vitro engagement tests, at NAA doses compatible with those observed in healthy brains and during brain injury. We observed that oligodendroglia cells respond to decreasing levels of NAA by stimulating differentiation and promoting gene expression of myelin proteins in a temporally regulated manner. Low doses of NAA potently stimulate Oli-neuM to engage with synthetic axons. Furthermore, we show a concentration-dependent expression of specific histone deacetylases essential for MBP gene expression under NAA or Clobetasol treatment. These data are consistent with the idea that oligodendrocytes respond to lowering the NAA concentration by activating the remyelination process via deacetylase activation.

Use of oral GnRH antagonists combined therapy in the management of symptomatic uterine fibroids

Uterine fibroids have an impact on women’s lives due to their high prevalence, physical symptoms, their consequences on patients’ emotional and psychological well-being and loss of work productivity. The choice of therapeutical approaches varies depending on several factors, and therefore should be applied individually. Currently, there is an unmet need for good, reliable, uterine-sparing options. The oral GnRH antagonists (Elagolix, Relugolix, Linzagolix) represent a new alternative for the medical management of hormone-dependent gynaecological diseases such as uterine fibroids or endometriosis. They rapidly bind to the GnRH receptor, block endogenous GnRH activity and directly suppress LH and FSH production, avoiding unwanted flare-up effects. Some GnRH antagonists are marketed in combination with hormone replacement therapy add-back to counteract hypo-oestrogenic side effects. According to the registration trials, once-daily GhRH antagonist combination therapy results in a significant reduction in menstrual bleeding, as compared with placebo, and preserves bone mineral density, for up to 104 weeks. Further studies in the long term are needed to evaluate the whole impact of medical treatment of uterine fibroids on the management of this common women’s disease.

Adaptive antioxidant response to mitochondrial fatty acid oxidation determines the proliferative outcome of cancer cells

Alterations in lipid catabolism have been broadly described in cancer cells and show tumor-type specific effects on proliferation and cell survival. The factor(s) responsible for this heterogeneity is currently unknown and represents the main limitation in the development of therapeutic interventions that impair lipid metabolism. In this study, we focused on hexanoic acid, a medium-chain fatty acid, that can quickly boost oxidative metabolism by passively crossing mitochondrial membranes. We demonstrated that the antioxidant adaptation of cancer cells to increased fatty acid oxidation is predictive of the proliferative outcome. By interfering with SOD1 expression and glutathione homeostasis, we verified that mitochondrial fatty acid oxidation has antitumor effects in cancer cells that efficiently buffer ROS. In contrast, increased ROS levels promote proliferation in cells with an imbalanced antioxidant response. In addition, an increase in mitochondrial mass and mitophagy activation were observed, respectively. Overall, these data demonstrate that the capacity to manage ROS from mitochondrial oxidative metabolism determines whether lipid catabolism is advantageous or detrimental for cancer cells.

Influenza virus replication is affected by glutaredoxin1-mediated protein deglutathionylation

Several redox modifications have been described during viral infection, including influenza virus infection, but little is known about glutathionylation and this respiratory virus. Glutathionylation is a reversible, post-translational modification, in which protein cysteine forms transient disulfides with glutathione (GSH), catalyzed by cellular oxidoreductases and in particular by glutaredoxin (Grx). We show here that (i) influenza virus infection induces protein glutathionylation, including that of viral proteins such as hemagglutinin (HA); (ii) Grx1-mediated deglutathionylation is important for the viral life cycle, as its inhibition, either with an inhibitor of its enzymatic activity or by siRNA, decreases viral replication. Overall these data contribute to the characterization of the complex picture of redox regulation of the influenza virus replication cycle and could help to identify new targets to control respiratory viral infection.

Hindering NAT8L expression in hepatocellular carcinoma increases cytosolic aspartate delivery that fosters pentose phosphate pathway and purine biosynthesis promoting cell proliferation

N-acetylaspartate (NAA) is synthesized by the mitochondrial enzyme NAT8L, which uses acetyl-CoA and aspartate as substrates. These metabolites are fundamental for bioenergetics and anabolic requirements of highly proliferating cells, thus, NAT8L modulation may impinge on the metabolic reprogramming of cancer cells. Specifically, aspartate represents a limiting amino acid for nucleotide synthesis in cancer. Here, the expression of the NAT8L enzyme was modulated to verify how it impacts the metabolic adaptations and proliferative capacity of hepatocellular carcinoma. We demonstrated that NAT8L downregulation is associated with increased proliferation of hepatocellular carcinoma cells and immortalized hepatocytes. The overexpression of NAT8L instead decreased cell growth. The pro-tumoral effect of NAT8L silencing depended on glutamine oxidation and the rewiring of glucose metabolism. Mechanistically, NAT8L downregulation triggers aspartate outflow from mitochondria via the exporter SLC25A13 to promote glucose flux into the pentose phosphate pathway, boosting purine biosynthesis. These results were corroborated by the analyses of human and mouse hepatocellular carcinoma samples revealing a decrease in NAT8L expression compared to adjacent non-tumoral tissues. Overall, this work demonstrates that NAT8L expression in liver cells limits the cytosolic availability of aspartate necessary for enhancing the pentose phosphate pathway and purine biosynthesis, counteracting cell proliferation.

The telomeric protein TERF2/TRF2 impairs HMGB1-driven autophagy

TERF2/TRF2 is a pleiotropic telomeric protein that plays a crucial role in tumor formation and progression through several telomere-dependent and -independent mechanisms. Here, we uncovered a novel function for this protein in regulating the macroautophagic/autophagic process upon different stimuli. By using both biochemical and cell biology approaches, we found that TERF2 binds to the non-histone chromatin-associated protein HMGB1, and this interaction is functional to the nuclear/cytoplasmic protein localization. Specifically, silencing of TERF2 alters the redox status of the cells, further exacerbated upon EBSS nutrient starvation, promoting the cytosolic translocation and the autophagic activity of HMGB1. Conversely, overexpression of wild-type TERF2, but not the mutant unable to bind HMGB1, negatively affects the cytosolic translocation of HMGB1, counteracting the stimulatory effect of EBSS starvation. Moreover, genetic depletion of HMGB1 or treatment with inflachromene, a specific inhibitor of its cytosolic translocation, completely abolished the pro-autophagic activity of TERF2 silencing. In conclusion, our data highlighted a novel mechanism through which TERF2 modulates the autophagic process, thus demonstrating the key role of the telomeric protein in regulating a process that is fundamental, under both physiological and pathological conditions, in defining the fate of the cells.Abbreviations: ALs: autolysosomes; ALT: alternative lengthening of telomeres; ATG: autophagy related; ATM: ATM serine/threonine kinase; CQ: Chloroquine; DCFDA: 2',7'-dichlorofluorescein diacetate; DDR: DNA damage response; DHE: dihydroethidium; EBSS: Earle's balanced salt solution; FACS: fluorescence-activated cell sorting; GFP: green fluorescent protein; EGFP: enhanced green fluorescent protein; GSH: reduced glutathione; GSSG: oxidized glutathione; HMGB1: high mobility group box 1; ICM: inflachromene; IF: immunofluorescence; IP: immunoprecipitation; NAC: N-acetyl-L-cysteine; NHEJ: non-homologous end joining; PLA: proximity ligation assay; RFP: red fluorescent protein; ROS: reactive oxygen species; TIF: telomere-induced foci; TERF2/TRF2: telomeric repeat binding factor 2.

DNA Methylation Analysis of Ribosomal DNA in Adults With Down Syndrome

Control of ribosome biogenesis is a critical aspect of the regulation of cell metabolism. As ribosomal genes (rDNA) are organized in repeated clusters on chromosomes 13, 14, 15, 21, and 22, trisomy of chromosome 21 confers an excess of rDNA copies to persons with Down syndrome (DS). Previous studies showed an alteration of ribosome biogenesis in children with DS, but the epigenetic regulation of rDNA genes has not been investigated in adults with DS so far. In this study, we used a targeted deep-sequencing approach to measure DNA methylation (DNAm) of rDNA units in whole blood from 69 adults with DS and 95 euploid controls. We further evaluated the expression of the precursor of ribosomal RNAs (RNA45S) in peripheral blood mononuclear cells (PBMCs) from the same subjects. We found that the rDNA promoter tends to be hypermethylated in DS concerning the control group. The analysis of epihaplotypes (the combination of methylated and unmethylated CpG sites along the same DNA molecule) showed a significantly lower intra-individual diversity in the DS group, which at the same time was characterized by a higher interindividual variability. Finally, we showed that RNA45S expression is lower in adults with DS. Collectively, our results suggest a rearrangement of the epigenetic profile of rDNA in DS, possibly to compensate for the extranumerary rDNA copies. Future studies should assess whether the regulation of ribosome biogenesis can contribute to the pathogenesis of DS and explain the clinical heterogeneity characteristic of the syndrome.

Imaging in gynecological disease (23): clinical and ultrasound characteristics of ovarian carcinosarcoma

OBJECTIVE

To describe the clinical and ultrasound characteristics of ovarian carcinosarcoma.

METHODS

This was a retrospective multicenter study. Patients with a histological diagnosis of ovarian carcinosarcoma, who had undergone preoperative ultrasound examination between 2010 and 2019, were identified from the International Ovarian Tumor Analysis (IOTA) database. Additional patients who were examined outside of the IOTA study were identified from the databases of the participating centers. The masses were described using the terms and definitions of the IOTA group. Additionally, two experienced ultrasound examiners reviewed all available images to identify typical ultrasound features using pattern recognition.

RESULTS

Ninety-one patients with ovarian carcinosarcoma who had undergone ultrasound examination were identified, of whom 24 were examined within the IOTA studies and 67 were examined outside of the IOTA studies. Median age at diagnosis was 66 (range, 33-91) years and 84/91 (92.3%) patients were postmenopausal. Most patients (67/91, 73.6%) were symptomatic, with the most common complaint being pain (51/91, 56.0%). Most tumors (67/91, 73.6%) were International Federation of Gynecology and Obstetrics (FIGO) Stage III or IV. Bilateral lesions were observed on ultrasound in 46/91 (50.5%) patients. Ascites was present in 38/91 (41.8%) patients. The median largest tumor diameter was 100 (range, 18-260) mm. All ovarian carcinosarcomas contained solid components, and most were described as solid (66/91, 72.5%) or multilocular-solid (22/91, 24.2%). The median diameter of the largest solid component was 77.5 (range, 11-238) mm. Moderate or rich vascularization was found in 78/91 (85.7%) cases. Retrospective analysis of ultrasound images and videoclips using pattern recognition in 73 cases revealed that all tumors had irregular margins and inhomogeneous echogenicity of the solid components. Forty-seven of 73 (64.4%) masses appeared as a solid tumor with cystic areas. Cooked appearance of the solid tissue was identified in 28/73 (38.4%) tumors. No pathognomonic ultrasound sign of ovarian carcinosarcoma was found.

CONCLUSIONS

Ovarian carcinosarcomas are usually diagnosed in postmenopausal women and at an advanced stage. The most common ultrasound appearance is a large solid tumor with irregular margins, inhomogeneous echogenicity of the solid tissue and cystic areas. The second most common pattern is a large multilocular-solid mass with inhomogeneous echogenicity of the solid tissue. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Lipid Catabolism and ROS in Cancer: A Bidirectional Liaison

Although cancer cell metabolism was mainly considered to rely on glycolysis, with the concomitant impairment of mitochondrial metabolism, it has recently been demonstrated that several tumor types are sustained by oxidative phosphorylation (OXPHOS). In this context, endogenous fatty acids (FAs) deriving from lipolysis or lipophagy are oxidised into the mitochondrion, and are used as a source of energy through OXPHOS. Because the electron transport chain is the main source of ROS, cancer cells relying on fatty acid oxidation (FAO) need to be equipped with antioxidant systems that maintain the ROS levels under the death threshold. In those conditions, ROS can act as second messengers, favouring proliferation and survival. Herein, we highlight the different responses that tumor cells adopt when lipid catabolism is augmented, taking into account the different ROS fates. Many papers have demonstrated that the pro- or anti-tumoral roles of endogenous FA usage are hugely dependent on the tumor type, and on the capacity of cancer cells to maintain redox homeostasis. In light of this, clinical studies have taken advantage of the boosting of lipid catabolism to increase the efficacy of tumor therapy, whereas, in other contexts, antioxidant compounds are useful to reduce the pro-survival effects of ROS deriving from FAO.

Extracellular vesicles in endothelial cells: from mediators of cell-to-cell communication to cargo delivery tools

Extracellular vesicles (EVs) are nanosized vesicles released from most cell types that play a key role in cell-to-cell communication by carrying DNA, non-coding RNAs, proteins and lipids out of cells. The composition of EVs depends on the cell or tissue of origin and changes according to their pathophysiological conditions, making EVs a potential circulating biomarker of disease. Additionally, the natural tropism of EVs for specific organs and cells has raised the interest in their use as delivery vehicles. In this review, we provide an overview of EV biogenesis, isolation and characterization. We also discuss EVs in the context of endothelial pathophysiology, summarizing the current knowledge about their role in cell communication in quiescent and activated endothelial cells. In the last part, we describe the potential use of EVs as delivery vehicles of bioactive compounds and the current strategies to load exogenous cargo and to functionalize EVs to drive them to a specific tissue.

Poly(ADP-Ribose) Polymerase Inhibitors for Arsenic Trioxide-Resistant Acute Promyelocytic Leukemia: Synergistic In Vitro Antitumor Effects with Hypomethylating Agents or High-Dose Vitamin C

Arsenic trioxide (ATO) is an anticancer agent used for the treatment ofacute promyelocytic leukemia (APL). However, 5%-10% of patients fail to respond or experience disease relapse. Based on poly(ADP-ribose) polymerase (PARP) 1 involvement in the processing of DNA demethylation, here we have tested the in vitro susceptibility of ATO-resistant clones (derived from the human APL cell line NB4) to PARP inhibitors (PARPi) in combination with hypomethylating agents (azacitidine and decitabine) or high-dose vitamin C (ascorbate), which induces 5-hydroxymethylcytosine (5hmC)-mediated DNA demethylation. ATO-sensitive and -resistant APL cell clones were generated and initially analyzed for their susceptibility to five clinically used PARPi (olaparib, niraparib, rucaparib, veliparib, and talazoparib). The obtained PARPi IC₅₀ values were far below (olaparib and niraparib), within the range (talazoparib), or above (rucaparib and veliparib) the C _max reported in patients, likely as a result of differences in the mechanisms of their cytotoxic activity. ATO-resistant APL cells were also susceptible to clinically relevant concentrations of azacitidine and decitabine and to high-dose ascorbate. Interestingly, the combination of these agents with olaparib, niraparib, or talazoparib resulted in synergistic antitumor activity. In combination with ascorbate, PARPi increased the ascorbate-mediated induction of 5hmC, which likely resulted in stalled DNA repair and cytotoxicity. Talazoparib was the most effective PARPi in synergizing with ascorbate, in accordance with its marked ability to trap PARP1 at damaged DNA. These findings suggest that ATO and PARPi have nonoverlapping resistance mechanisms and support further investigation on PARPi combination with hypomethylating agents or high-dose ascorbate for relapsed/ATO-refractory APL, especially in frail patients. SIGNIFICANCE STATEMENT: This study found that poly(ADP-ribose) inhibitors (PARPi) show activity as single agents against human acute promyelocytic leukemia cells resistant to arsenic trioxide at clinically relevant concentrations. Furthermore, PARPi enhance the in vitro efficacy of azacitidine, decitabine, and high-dose vitamin C, all agents that alter DNA methylation. In combination with vitamin C, PARPi increase the levels of 5-hydroxymethylcytosine, likely as a result of altered processing of the oxidized intermediates associated with DNA demethylation.

Label-free metabolic clustering through unsupervised pixel classification of multiparametric fluorescent images

Autofluorescence microscopy is a promising label-free approach to characterize NADH and FAD metabolites in live cells, with potential applications in clinical practice. Although spectrally resolved lifetime imaging techniques can acquire multiparametric information about the biophysical and biochemical state of the metabolites, these data are evaluated at the whole-cell level, thus providing only limited insights in the activation of metabolic networks at the microscale. To overcome this issue, here we introduce an artificial intelligence-based analysis that, leveraging the multiparametric content of spectrally resolved lifetime images, allows to detect and classify, through an unsupervised learning approach, metabolic clusters, which are regions having almost uniform metabolic properties. This method contextually detects the cellular mitochondrial turnover and the metabolic activation state of intracellular compartments at the pixel level, described by two functions: the cytosolic activation state (CAF) and the mitochondrial activation state (MAF). This method was applied to investigate metabolic changes elicited in the breast cancer cell line MCF-7 by specific inhibitors of glycolysis and electron transport chain, and by the deregulation of a specific mitochondrial enzyme (ACO2) leading to defective aerobic metabolism associated with tumor growth. In this model, mitochondrial fraction undergoes to a 13% increase upon ACO2 overexpression and the MAF function changes abruptly by altering the metabolic state of about the 25% of the mitochondrial pixels.

Elective Treatment of Large-Bowel Obstruction in Asymptomatic Sigmoid Volvulus

BACKGROUND

Sigmoid volvulus is an uncommon cause of intestinal obstruction representing the 5% of all Western cases, associated with old age and a history of neurological and psychiatric condition. Generally, its diagnosis is established by clinical and radiologic findings. It often represents an emergency and it is commonly associated with pain, vomit and abdominal tenderness.

CASE PRESENTATION

We present a case of a 59 years old man, admitted to our emergency department, showing an abdominal X-Ray reporting a distention of large bowel,which was required due to presence of multiple diarrhea episodes during the previous 7 days. He had no significant past medical history and did not report constipation or subocclusive episode.

CONCLUSIONS

Volvulus should be considered in the differential diagnosis in adult and healthy patients with bowel obstructions. Surgery is, in all cases, the radical and definitive treatment since there is a higher mortality in case of recurrent volvulus. Despite the massive bowel distention, our choice was the elective open surgery. Primary anastomosis is feasible and safe and did not lead to any complications. In case of unsuccessful colonic decompression, evidence to support or refute the safety and effectiveness of laparoscopic surgical resection for treatment of patients with sigmoid volvulus disease is not yet proven.

Aconitase 2 sensitizes MCF-7 cells to cisplatin eliciting p53-mediated apoptosis in a ROS-dependent manner

Aconitase 2 (ACO2) belongs to the tricarboxylic acid (TCA) cycle, which represents a key metabolic hub for cellular metabolism that is frequently altered in cancer for satisfying bioenergetic and biosynthetic requirements of proliferating cells. The promotion of ACO2 activity in breast cancer cell lines was shown to slow down proliferation imposing a switch from aerobic glycolysis to oxidative metabolism. The alteration of metabolic pathways in cancer also impinges on the sensitivity to chemotherapeutic interventions. In this work, we evidence that the presence of ACO2 sensitizes cells to the treatment with the genotoxic agents cisplatin (CDDP) and doxorubicin activating the apoptotic cell death mechanism. This response was driven by the accumulation of reactive oxygen species (ROS) following both ACO2 overexpression and CDDP exposure that permit the stabilization/activation of p53 in nuclear and mitochondrial compartments. Collectively, our results highlight that in ACO2 overexpressing cells the promotion of mitochondrial metabolism accounts for increased ROS production that was buffered by p53 mitochondrial recruitment and autophagy induction. However, these systems are not able to counteract the CDDP-mediated oxidative stress that becomes the Achilles heel for increasing susceptibility to apoptotic cell death.

Perineal trauma with anal avulsion: case report

Anorectal avulsion is an exceptional rectal trauma. In this kind of lesions, the anus and the sphincter no longer join the perineum and are pulled upward. We present a case of 34-years-old patient who was admitted because of a pelvic-perineal trauma, presenting a partial anorectal avulsion, exposed femoral fracture with thigh's lacerated-contused wound. Our treatment included primary plastic of the internal anal sphincter with replanting of the rectum on the anal canal and a diverting loop sigmoid colostomy (SCS), so as to prevent sepsis. Closure of the protective SCS was performed four months after the trauma.

Aconitase 2 inhibits the proliferation of MCF-7 cells promoting mitochondrial oxidative metabolism and ROS/FoxO1-mediated autophagic response

Background

Deregulation of the tricarboxylic acid cycle (TCA) due to mutations in specific enzymes or defective aerobic metabolism is associated with tumour growth. Aconitase 2 (ACO2) participates in the TCA cycle by converting citrate to isocitrate, but no evident demonstrations of its involvement in cancer metabolism have been provided so far.

Methods

Biochemical assays coupled with molecular biology, in silico, and cellular tools were applied to circumstantiate the impact of ACO2 in the breast cancer cell line MCF-7 metabolism. Fluorescence lifetime imaging microscopy (FLIM) of NADH was used to corroborate the changes in bioenergetics.

Results

We showed that ACO2 levels are decreased in breast cancer cell lines and human tumour biopsies. We generated ACO2- overexpressing MCF-7 cells and employed comparative analyses to identify metabolic adaptations. We found that increased ACO2 expression impairs cell proliferation and commits cells to redirect pyruvate to mitochondria, which weakens Warburg-like bioenergetic features. We also demonstrated that the enhancement of oxidative metabolism was supported by mitochondrial biogenesis and FoxO1-mediated autophagy/mitophagy that sustains the increased ROS burst.

Conclusions

This work identifies ACO2 as a relevant gene in cancer metabolic rewiring of MCF-7 cells, promoting a different utilisation of pyruvate and revealing the potential metabolic vulnerability of ACO2-associated malignancies.

Imaging in gynecological disease (16): clinical and ultrasound characteristics of serous cystadenofibromas in adnexa

OBJECTIVE

To describe the clinical and ultrasound characteristics of serous cystadenofibromas in the adnexa.

METHODS

This was a retrospective study of patients identified in the International Ovarian Tumor Analysis (IOTA) database, who had a histological diagnosis of serous cystadenofibroma and had undergone preoperative ultrasound examination by an experienced ultrasound examiner, between 1999 and 2012. In the IOTA database, which contains data collected prospectively, the tumors were described using the terms and definitions of the IOTA group. In addition, three authors reviewed, first independently and then together, ultrasound images of serous cystadenofibromas and described them using pattern recognition.

RESULTS

We identified 233 women with a histological diagnosis of serous cystadenofibroma. In the IOTA database, most cystadenofibromas (67.4%; 157/233) were described as containing solid components but 19.3% (45/233) were described as multilocular cysts and 13.3% (31/233) as unilocular cysts. Papillary projections were described in 52.4% (122/233) of the cystadenofibromas. In 79.5% (97/122) of the cysts with papillary projections, color Doppler signals were absent in the papillary projections. Most cystadenofibromas (83.7%; 195/233) manifested no or minimal color Doppler signals. On retrospective analysis of 201 ultrasound images of serous cystadenofibromas, using pattern recognition, 10 major types of ultrasound appearance were identified. The most common pattern was a unilocular solid cyst with one or more papillary projections, but no other solid components (25.9%; 52/201). The second most common pattern was a multilocular solid mass with small solid component(s), but no papillary projections (19.4%; 39/201). The third and fourth most common patterns were multi- or bilocular cyst (16.9%; 34/201) and unilocular cyst (11.9%; 24/201). Using pattern recognition, shadowing was identified in 39.8% (80/201) of the tumors, and microcystic appearance of the papillary projections was observed in 34 (38.6%) of the 88 tumors containing papillary projections.

CONCLUSIONS

The ultrasound features of serous cystadenofibromas vary. The most common pattern is a unilocular solid cyst with one or more papillary projections but no other solid components, with absent color Doppler signals. Most serous cystadenofibromas were poorly vascularized on color Doppler examination and many manifested acoustic shadowing. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Paternal activation of CB2 cannabinoid receptor impairs placental and embryonic growth via an epigenetic mechanism

The cannabinoid receptor type 2 (CB₂) is the peripheral receptor for cannabinoids, involved in the homeostatic control of several physiological functions. Male mitotic germ cells express a high level of CB₂, whose activation promotes their differentiation in both in vitro and in vivo experiments, controlling the correct progression of spermatogenesis. However, it remains elusive if CB₂ activation in spermatogonia could affect reproductive success in terms of fertility and healthy pregnancy outcomes. In this study, we explored the effects of male CB₂ activation on sperm number and quality and its influence on next generation health. We show that exposure of male mice to JWH-133, a selective CB₂ agonist, decreased sperm count, impaired placental development and reduced offspring growth. These defects were associated with altered DNA methylation/hydroxymethylation levels at imprinted genes in sperm and conserved in placenta. Our findings reveal that paternal selective activation of CB₂ alters the sperm epigenome and compromises offspring growth. This study demonstrates, for the first time, a new role of CB₂ signaling in male gametes in causing epigenetic alterations that can be transmitted to the next generation by sperm, highlighting potential risks induced by recreational cannabinoid exposure.

Imaging in gynecological disease (15): clinical and ultrasound characteristics of uterine sarcoma

OBJECTIVE

To describe the clinical and ultrasound characteristics of uterine sarcomas.

METHODS

This was a retrospective multicenter study. From the databases of 13 ultrasound centers, we identified patients with a histological diagnosis of uterine sarcoma with available ultrasound reports and ultrasound images who had undergone preoperative ultrasound examination between 1996 and 2016. As the first step, each author collected information from the original ultrasound reports from his/her own center on predefined ultrasound features of the tumors and by reviewing the ultrasound images to identify information on variables not described in the original report. As the second step, 16 ultrasound examiners reviewed the images electronically in a consensus meeting and described them using predetermined terminology.

RESULTS

We identified 116 patients with leiomyosarcoma, 48 with endometrial stromal sarcoma and 31 with undifferentiated endometrial sarcoma. Median age of the patients was 56 years (range, 26-86 years). Most patients were symptomatic at diagnosis (164/183 (89.6%)), the most frequent presenting symptom being abnormal vaginal bleeding (91/183 (49.7%)). Patients with endometrial stromal sarcoma were younger than those with leiomyosarcoma and undifferentiated endometrial sarcoma (median age, 46 years vs 57 and 60 years, respectively). According to the assessment by the original ultrasound examiners, the median diameter of the largest tumor was 91 mm (range, 7-321 mm). Visible normal myometrium was reported in 149/195 (76.4%) cases, and 80.0% (156/195) of lesions were solitary. Most sarcomas (155/195 (79.5%)) were solid masses (> 80% solid tissue), and most manifested inhomogeneous echogenicity of the solid tissue (151/195 (77.4%)); one sarcoma was multilocular without solid components. Cystic areas were described in 87/195 (44.6%) tumors and most cyst cavities had irregular walls (67/87 (77.0%)). Internal shadowing was observed in 42/192 (21.9%) sarcomas and fan-shaped shadowing in 4/192 (2.1%). Moderate or rich vascularization was found on color-Doppler examination in 127/187 (67.9%) cases. In 153/195 (78.5%) sarcomas, the original ultrasound examiner suspected malignancy. Though there were some differences, the results of the first and second steps of the analysis were broadly similar.

CONCLUSIONS

Uterine sarcomas typically appear as solid masses with inhomogeneous echogenicity, sometimes with irregular cystic areas but only very occasionally with fan-shaped shadowing. Most are moderately or very well vascularized. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Synchronous primary cancers of endometrium and ovary vs endometrial cancer with ovarian metastasis: an observational study

OBJECTIVE

To compare the ultrasound characteristics of patients with synchronous primary cancers of the endometrium and ovary vs those of patients with endometrial cancer with ovarian metastasis.

METHODS

This was a single-institution retrospective observational study of patients with a histological diagnosis of endometrial cancer and an ovarian malignant mass, who had undergone preoperative ultrasound examination at our unit. Based on the histological diagnosis, patients were classified into two groups: those with synchronous primary cancers of the endometrium and ovary (synchronous group) and patients with endometrial cancer with ovarian metastasis (metastasis group). We compared the ultrasound features of ovarian malignant masses and of endometrial cancers between the two groups. Student's t-test, Mann-Whitney U-test, χ² test or Fisher's exact test were used for comparisons of variables between the two histological groups, as appropriate.

RESULTS

We identified 131 patients, of whom 51 had synchronous primary cancers of the endometrium and ovary (synchronous group) and 80 had endometrial cancer with ovarian metastasis (metastasis group). On ultrasound examination, ovarian masses in the synchronous group were more often multilocular-solid and less often bilateral than those in the metastasis group. With respect to the ultrasound features of the endometrial lesions, the median largest diameter was 29 (range, 11-118) mm in the synchronous group in comparison with 51.5 (range, 6-150) mm in the metastasis group (P < 0.0001). Endometrial lesions in the synchronous group presented more often with no myometrial infiltration and less often with a multiple-vessel pattern on color Doppler compared with the endometrial lesions in the metastasis group.

CONCLUSIONS

Synchronous primary cancers of the endometrium and ovary have significantly different sonomorphological patterns compared with endometrial cancer with ovarian metastasis. Ovarian masses in women with synchronous primary cancers of the endometrium and ovary appeared as unilateral multilocular-solid or solid masses, whereas ovarian masses in women with endometrial cancer with ovarian metastasis were mostly bilateral solid masses. The different sonomorphology of these two cancers may facilitate their preoperative identification, helping the surgeon to determine optimum management for the patient. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

FoxO1 localizes to mitochondria of adipose tissue and is affected by nutrient stress

OBJECTIVE

Mitochondria play pivotal roles in orchestrating signaling pathways in order to guarantee metabolic homeostasis under different stimuli. It has been demonstrated that the mito-nuclear communication is fundamental for facing physiological and/or stress-mediated cellular response through the activation of nuclear transcription factors. Here, we focused on the Forkhead box protein O1 (FoxO1) transcription factor that belongs to the FoxOs family proteins and is considered a "nutrients sensor" modulating the expression of nutrient-stress response genes.

METHODS

In vitro and in vivo experimental systems, including 3T3-L1 white, X-9 beige and T37i brown adipocytes and different fat depots from C57BL/6 mice were used. The mitochondrial localization of FoxO1 was demonstrated by western blot analysis, confocal microscopy and chromatin immunoprecipitation assay, after sub-cellular compartment isolation. RT-qPCR analysis was used to evaluate the expression of antioxidant and mitochondrial genes after modulation of FoxO1 activity/localization. Treatment with diverse reactive oxygen species (ROS) species/sources were performed and assessed by cytofluorimetric analysis.

RESULTS

We demonstrated that FoxO1 not exclusively localizes to cytosol and nucleus of adipocytes but also to mitochondria where it binds to mitochondrial DNA. We also proved that mitochondrial FoxO1 is phosphorylated upon normal feeding condition. Mitochondrial FoxO1 responds to starvation leaving mitochondrial compartment by ROS-mediated activation of the mitochondrial phosphatase PTPMT1. Indeed, FoxO1 de-phosphorylation and mito-to-nucleus shuttling was observed under starvation. Moreover, we provided evidence that ROS species/sources are able to differently modulate the mitochondrial localization of FoxO1.

CONCLUSION

The ability to localize at different cell compartments, including mitochondria, highlights a different layer of regulation of FoxO1 necessary for assuring a fast and efficient nutrient-stress response in white/beige adipose tissue. FoxO1 could be thus endorsed in the list of transcription factors involved in the mito-nuclear communication where ROS can act as upstream signals.

High Dietary Fat Intake Affects DNA Methylation/Hydroxymethylation in Mouse Heart: Epigenetic Hints for Obesity-Related Cardiac Dysfunction

SCOPE

Epigenetic aberrations caused by environmental factors and lifestyle choices have been associated with the development of a number of pathologies, including cardiovascular disorders. However, whether obesity-related heart dysfunction can occur via epigenetic mechanisms is largely undisclosed. The manifested role of DNA hydroxymethylation in heart pathophysiology prompts an investigation of its levels/machinery in heart of mice fed with high-fat diet (HFD) and its possible relation with genes linked to obesity-associated cardiac remodeling.

METHODS AND RESULTS

Alterations in levels of DNA methylation/hydroxymethylation modifications and in expression of Tet family of DNA hydroxylases are observed in hearts of mice treated with HFD for 8 and 16 weeks. Decreased levels of the Tet co-substrate α-ketoglutarate are also observed and associate with mitochondrial mass reduction and augmented oxidative stress. Finally, expression markers of cardiac remodeling are monitored by RT-qPCR analysis and associate with DNA hydroxymethylation signature by DNA immunoprecipitation and correlation analyses.

CONCLUSION

Global changes of DNA hydroxymethylation in hearts of HFD-fed mice are associated with upregulation of the dioxygenase Tet3 and decreased content of α-ketoglutarate. A relation between Tet genes and markers of cardiac hypertrophic response is observed and, if further validated, it will provide insights concerning epigenetics and obesity-related cardiac complications.

Imaging in gynecological disease (14): clinical and ultrasound characteristics of ovarian clear cell carcinoma

OBJECTIVE

To describe the clinical and ultrasound characteristics of ovarian pure clear cell carcinoma.

METHODS

This was a retrospective study involving data from 11 ultrasound centers. From the International Ovarian Tumor Analysis (IOTA) database, 105 patients who had undergone preoperative ultrasound examination by an experienced ultrasound examiner between 1999 and 2016 were identified with a histologically confirmed pure clear cell carcinoma of the ovary. An additional 47 patients diagnosed with pure clear cell carcinoma between 1999 and 2016 and with available complete preoperative ultrasound reports were identified retrospectively from the databases of the departments of gynecological oncology in the participating centers. The ultrasound images of all tumors were described using IOTA terminology. Clinical and ultrasound characteristics were analyzed for the whole group, and separately, for patients with and those without histologically confirmed endometriosis, and for patients with evidence of tumor developing from endometriosis.

RESULTS

Median age of the 152 patients was 53.5 (range, 28-92) years and 92/152 (60.5%) tumors were FIGO Stage I. Most tumors (128/152, 84.2%) were unilateral. On ultrasound examination, all tumors contained solid components and 36/152 (23.7%) were completely solid masses. The median largest diameter of the lesion was 117 (range, 25-310) mm. Papillary projections were present in 58/152 (38.2%) masses and, in most of these (51/56, 91.1%), vascularized papillary projections were seen. Information regarding the presence, site and type of pelvic endometriosis at histology was available for 130/152 patients. Endometriosis was noted in 54 (41.5%) of these. In 24/130 (18.6%) patients, the tumor was judged to have developed from endometriosis. Patients with, compared to those without, evidence of tumor developing from endometriosis were younger (median 47.5 vs 55.0 years, respectively), and ground-glass echogenicity of cyst fluid was more common in pure clear cell cancers developing from endometriosis (10/20 vs 13/79 (50.0% vs 16.5%), respectively).

CONCLUSIONS

Ovarian pure clear cell carcinoma is usually diagnosed at an early stage and typically appears as a large unilateral mass with solid components. Patients with clear cell carcinoma developing from endometriosis are younger than other patients with clear cell carcinoma, and clear cell cancers developing from endometriosis more often manifest ground-glass echogenicity of cyst fluid. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

DNA Hydroxymethylation Levels Are Altered in Blood Cells From Down Syndrome Persons Enrolled in the MARK-AGE Project

Down syndrome (DS) is caused by the presence of part or an entire extra copy of chromosome 21, a phenomenon that can cause a wide spectrum of clinically defined phenotypes of the disease. Most of the clinical signs of DS are typical of the aging process including dysregulation of immune system. Beyond the causative genetic defect, DS persons display epigenetic alterations, particularly aberrant DNA methylation patterns that can contribute to the heterogeneity of the disease. In the present work, we investigated the levels of 5-hydroxymethylcytosine and of the Ten-eleven translocation dioxygenase enzymes, which are involved in DNA demethylation processes and are often deregulated in pathological conditions as well as in aging. Analyses were carried out on peripheral blood mononuclear cells of DS volunteers enrolled in the context of the MARK-AGE study, a large-scale cross-sectional population study with subjects representing the general population in eight European countries. We observed a decrease in 5-hydroxymethylcytosine, TET1, and other components of the DNA methylation/demethylation machinery in DS subjects, indicating that aberrant DNA methylation patterns in DS, which may have consequences on the transcriptional status of immune cells, may be due to a global disturbance of methylation control in DS.

Analysis of the machinery and intermediates of the 5hmC-mediated DNA demethylation pathway in aging on samples from the MARK-AGE Study

Gradual changes in the DNA methylation landscape occur throughout aging virtually in all human tissues. A widespread reduction of 5-methylcytosine (5mC), associated with highly reproducible site-specific hypermethylation, characterizes the genome in aging. Therefore, an equilibrium seems to exist between general and directional deregulating events concerning DNA methylation controllers, which may underpin the age-related epigenetic changes. In this context, 5mC-hydroxylases (TET enzymes) are new potential players. In fact, TETs catalyze the stepwise oxidation of 5mC to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC), driving the DNA demethylation process based on thymine DNA glycosylase (TDG)-mediated DNA repair pathway. The present paper reports the expression of DNA hydroxymethylation components, the levels of 5hmC and of its derivatives in peripheral blood mononuclear cells of age-stratified donors recruited in several European countries in the context of the EU Project 'MARK-AGE'. The results provide evidence for an age-related decline of TET1, TET3 and TDG gene expression along with a decrease of 5hmC and an accumulation of 5caC. These associations were independent of confounding variables, including recruitment center, gender and leukocyte composition. The observed impairment of 5hmC-mediated DNA demethylation pathway in blood cells may lead to aberrant transcriptional programs in the elderly.

The TCA cycle as a bridge between oncometabolism and DNA transactions in cancer

Cancer cells exploit metabolic rearrangements for sustaining their high proliferation rate and energy demand. The TCA cycle is a central metabolic hub necessary for ATP production and for providing precursors used in many biosynthetic pathways. Thus, dysregulation of the TCA cycle flux is frequently observed in cancer. The identification of mutations in several enzymes of the TCA cycle in human tumours demonstrated a direct connection between this metabolic pathway and cancer occurrence. Moreover, changes in the expression/activity of these enzymes were also shown to promote metabolic adaptation of cancer cells. In this review, the main genetic and non-genetic alterations of TCA cycle in cancer will be described. Particular attention will be given to extrametabolic roles of TCA cycle enzymes and metabolites underlying the regulation of nuclear and mitochondrial DNA transactions.

PARP1 orchestrates epigenetic events setting up chromatin domains

Epigenetic events include reversible modifications of DNA and histone tails driving chromatin organization and thus transcription. The epigenetic regulation is a highly integrated process underlying the plasticity of the genomic information both in the context of complex physiological and pathological processes. The global regulatory aspects of epigenetic events are largely unknown. PARylation and PARP1 are recently emerging as multi-level regulatory effectors that modulate the topology of chromatin by orchestrating very different processes. This review focuses in particular on the role of PARP1 in epigenetics, trying to build a comprehensive perspective of its involvement in the regulation of epigenetic modifications of histones and DNA, contextualizing it in the global organization of chromatin domains in the nucleus.

5mC-hydroxylase activity is influenced by the PARylation of TET1 enzyme

5-hydroxymethylcytosine is a new epigenetic modification deriving from the oxidation of 5-methylcytosine by the TET hydroxylase enzymes. DNA hydroxymethylation drives DNA demethylation events and is involved in the control of gene expression. Deregulation of TET enzymes causes developmental defects and is associated with pathological conditions such as cancer. Little information thus far is available on the regulation of TET activity by post-translational modifications. Here we show that TET1 protein is able to interact with PARP-1/ARTD1 enzyme and is target of both noncovalent and covalent PARylation. In particular, we have demonstrated that the noncovalent binding of ADP-ribose polymers with TET1 catalytic domain decreases TET1 hydroxylase activity while the covalent PARylation stimulates TET1 enzyme. In addition, TET1 activates PARP-1/ARTD1 independently of DNA breaks. Collectively, our results highlight a complex interplay between PARylation and TET1 which may be helpful in coordinating the multiple biological roles played by 5-hydroxymethylcytosine and TET proteins.

Age-dependent expression of DNMT1 and DNMT3B in PBMCs from a large European population enrolled in the MARK-AGE study

Aging is associated with alterations in the content and patterns of DNA methylation virtually throughout the entire human lifespan. Reasons for these variations are not well understood. However, several lines of evidence suggest that the epigenetic instability in aging may be traced back to the alteration of the expression of DNA methyltransferases. Here, the association of the expression of DNA methyltransferases DNMT1 and DNMT3B with age has been analysed in the context of the MARK-AGE study, a large-scale cross-sectional study of the European general population. Using peripheral blood mononuclear cells, we assessed the variation of DNMT1 and DNMT3B gene expression in more than two thousand age-stratified women and men (35-75 years) recruited across eight European countries. Significant age-related changes were detected for both transcripts. The level of DNMT1 gradually dropped with aging but this was only observed up to the age of 64 years. By contrast, the expression of DNMT3B decreased linearly with increasing age and this association was particularly evident in females. We next attempted to trace the age-related changes of both transcripts to the influence of different variables that have an impact on changes of their expression in the population, including demographics, dietary and health habits, and clinical parameters. Our results indicate that age affects the expression of DNMT1 and DNMT3B as an almost independent variable in respect of all other variables evaluated.

Poly(ADP-ribosyl)ation is involved in the epigenetic control of TET1 gene transcription

TET enzymes are the epigenetic factors involved in the formation of the sixth DNA base 5-hydroxymethylcytosine, whose deregulation has been associated with tumorigenesis. In particular, TET1 acts as tumor suppressor preventing cell proliferation and tumor metastasis and it has frequently been found down-regulated in cancer. Thus, considering the importance of a tight control of TET1 expression, the epigenetic mechanisms involved in the transcriptional regulation of TET1 gene are here investigated. The involvement of poly(ADP-ribosyl)ation in the control of DNA and histone methylation on TET1 gene was examined. PARP activity is able to positively regulate TET1 expression maintaining a permissive chromatin state characterized by DNA hypomethylation of TET1 CpG island as well as high levels of H3K4 trimethylation. These epigenetic modifications were affected by PAR depletion causing TET1 down-regulation and in turn reduced recruitment of TET1 protein on HOXA9 target gene. In conclusion, this work shows that PARP activity is a transcriptional regulator of TET1 gene through the control of epigenetic events and it suggests that deregulation of these mechanisms could account for TET1 repression in cancer.

R-spondin 1/dickkopf-1/beta-catenin machinery is involved in testicular embryonic angiogenesis

Testicular vasculogenesis is one of the key processes regulating male gonad morphogenesis. The knowledge of the molecular cues underlining this phenomenon is one of today’s most challenging issues and could represent a major contribution toward a better understanding of the onset of testicular morphogenetic disorders. R-spondin 1 has been clearly established as a candidate for mammalian ovary determination. Conversely, very little information is available on the expression and role of R-spondin 1 during testicular morphogenesis. This study aims to clarify the distribution pattern of R-spondin 1 and other partners of its machinery during the entire period of testicular morphogenesis and to indicate the role of this system in testicular development. Our whole mount immunofluorescence results clearly demonstrate that R-spondin 1 is always detectable in the testicular coelomic partition, where testicular vasculature is organized, while Dickkopf-1 is never detectable in this area. Moreover, organ culture experiments of embryonic male UGRs demonstrated that Dickkopf-1 acted as an inhibitor of testis vasculature formation. Consistent with this observation, real-time PCR analyses demonstrated that DKK1 is able to slightly but significantly decrease the expression level of the endothelial marker Pecam1. The latter experiments allowed us to observe that DKK1 administration also perturbs the expression level of the Pdgf-b chain, which is consistent with some authors’ observations relating this factor with prenatal testicular patterning and angiogenesis. Interestingly, the DKK1 induced inhibition of testicular angiogenesis was rescued by the co-administration of R-spondin 1. In addition, R-spondin 1 alone was sufficient to enhance, in culture, testicular angiogenesis.

Reconfiguration of DNA methylation in aging

A complex interplay between multiple biological effects shapes the aging process. The advent of genome-wide quantitative approaches in the epigenetic field has highlighted the effective impact of epigenetic deregulation, particularly of DNA methylation, on aging. Age-associated alterations in DNA methylation are commonly grouped in the phenomenon known as "epigenetic drift" which is characterized by gradual extensive demethylation of genome and hypermethylation of a number of promoter-associated CpG islands. Surprisingly, specific DNA regions show directional epigenetic changes in aged individuals suggesting the importance of these events for the aging process. However, the epigenetic information obtained until now in aging needs a re-consideration due to the recent discovery of 5-hydroxymethylcytosine, a new DNA epigenetic mark present on genome. A recapitulation of the factors involved in the regulation of DNA methylation and the changes occurring in aging will be described in this review also considering the data available on 5 hmC.

The epigenetic factor BORIS/CTCFL regulates the NOTCH3 gene expression in cancer cells

Aberrant upregulation of NOTCH3 gene plays a critical role in cancer pathogenesis. However, the underlying mechanisms are still unknown. We tested here the hypothesis that aberrant epigenetic modifications in the NOTCH3 promoter region might account for its upregulation in cancer cells. We compared DNA and histone methylation status of NOTCH3 promoter region in human normal blood cells and T cell acute lymphoblastic leukemia (T-ALL) cell lines, differentially expressing NOTCH3. We found that histone methylation, rather than DNA hypomethylation, contributes towards establishing an active chromatin status of NOTCH3 promoter in NOTCH3 overexpressing cancer cells. We discovered that the chromatin regulator protein BORIS/CTCFL plays an important role in regulating NOTCH3 gene expression. We observed that BORIS is present in T-ALL cell lines as well as in cell lines derived from several solid tumors overexpressing NOTCH3. Moreover, BORIS targets NOTCH3 promoter in cancer cells and it is able to induce and to maintain a permissive/active chromatin conformation. Importantly, the association between NOTCH3 overexpression and BORIS presence was confirmed in primary T-ALL samples from patients at the onset of the disease. Overall, our results provide novel insights into the determinants of NOTCH3 overexpression in cancer cells, by revealing a key role for BORIS as the main mediator of transcriptional deregulation of NOTCH3.

TET2 gene expression and 5-hydroxymethylcytosine level in multiple sclerosis peripheral blood cells

Aberrant DNA methylation can lead to genome destabilization and to deregulated gene expression. Recently, 5-hydroxymethylcytosine (5hmC), derived from oxidation of 5-methylcytosine (5mC) by the Ten-Eleven Translocation (TET) enzymes, has been detected. 5hmC is now considered as a new epigenetic DNA modification with relevant roles in cell homeostasis regulating DNA demethylation and transcription. Our aim was to investigate possible changes in the DNA methylation/demethylation machinery in MS. We assessed the expression of enzymes involved in DNA methylation/demethylation in peripheral blood mononuclear cells (PBMCs) from 40 subjects with MS and 40 matched healthy controls. We performed also, DNA methylation analysis of specific promoters and analysis of global levels of 5mC and 5hmC. We show that TET2 and DNMT1 expression is significantly down-regulated in MS PBMCs and it is associated with aberrant methylation of their promoters. Furthermore, 5hmC is decreased in MS PBMCs, probably as a result of the diminished TET2 level.

Pharmacological inhibition of poly(ADP-ribose) polymerase-1 modulates resistance of human glioblastoma stem cells to temozolomide

BACKGROUND

Chemoresistance of glioblastoma multiforme (GBM) has been attributed to the presence within the tumor of cancer stem cells (GSCs). The standard therapy for GBM consists of surgery followed by radiotherapy and the chemotherapeutic agent temozolomide (TMZ). However, TMZ efficacy is limited by O6-methylguanine-DNA-methyltransferase (MGMT) and Mismatch Repair (MMR) functions. Strategies to counteract TMZ resistance include its combination with poly(ADP-ribose) polymerase inhibitors (PARPi), which hamper the repair of N-methylpurines. PARPi are also investigated as monotherapy for tumors with deficiency of homologous recombination (HR). We have investigated whether PARPi may restore GSC sensitivity to TMZ or may be effective as monotherapy.

METHODS

Ten human GSC lines were assayed for MMR proteins, MGMT and PARP-1 expression/activity, MGMT promoter methylation and sensitivity to TMZ or PARPi, alone and in combination. Since PTEN defects are frequently detected in GBM and may cause HR dysfunction, PTEN expression was also analyzed. The statistical analysis of the differences in drug sensitivity among the cell lines was performed using the ANOVA and Bonferroni's post-test or the non-parametric Kruskal-Wallis analysis and Dunn's post-test for multiple comparisons. Synergism between TMZ and PARPi was analyzed by the median-effect method of Chou and Talalay. Correlation analyses were done using the Spearman's rank test.

RESULTS

All GSCs were MMR-proficient and resistance to TMZ was mainly associated with high MGMT activity or low proliferation rate. MGMT promoter hypermethylation of GSCs correlated both with low MGMT activity/expression (Spearman's test, P = 0.004 and P = 0.01) and with longer overall survival of GBM patients (P = 0.02). Sensitivity of each GSC line to PARPi as single agent did not correlate with PARP-1 or PTEN expression. Notably, PARPi and TMZ combination exerted synergistic antitumor effects in eight out of ten GSC lines and the TMZ dose reduction achieved significantly correlated with the sensitivity of each cell line to PARPi as single agent (P = 0.01).

CONCLUSIONS

The combination of TMZ with PARPi may represent a valuable strategy to reverse GSC chemoresistance.

Poly(ADP-ribosyl)ation acts in the DNA demethylation of mouse primordial germ cells also with DNA damage-independent roles

Poly(ADP-ribosyl)ation regulates chromatin structure and transcription driving epigenetic events. In particular, Parp1 is able to directly influence DNA methylation patterns controlling transcription and activity of Dnmt1. Here, we show that ADP-ribose polymer levels and Parp1 expression are noticeably high in mouse primordial germ cells (PGCs) when the bulk of DNA demethylation occurs during germline epigenetic reprogramming in the embryo. Notably, Parp1 activity is stimulated in PGCs even before its participation in the DNA damage response associated with active DNA demethylation. We demonstrate that PARP inhibition impairs both genome-wide and locus-specific DNA methylation erasure in PGCs. Moreover, we evidence that impairment of PARP activity causes a significant reduction of expression of the gene coding for Tet1 hydroxylases involved in active DNA demethylation. Taken together these results demonstrate new and adjuvant roles of poly(ADP-ribosyl)ation during germline DNA demethylation and suggest its possible more general involvement in genome reprogramming.

Methylation-dependent PAD2 upregulation in multiple sclerosis peripheral blood

BACKGROUND

Peptidylarginine deiminase 2 (PAD2) and peptidylarginine deiminase 4 (PAD4) are two members of PAD family which are over-expressed in the multiple sclerosis (MS) brain. Through its enzymatic activity PAD2 converts myelin basic protein (MBP) arginines into citrullines - an event that may favour autoimmunity - while peptidylarginine deiminase 4 (PAD4) is involved in chromatin remodelling.

OBJECTIVES

Our aim was to verify whether an altered epigenetic control of PAD2, as already shown in the MS brain, can be observed in peripheral blood mononuclear cells (PBMCs) of patients with MS since some of these cells also synthesize MBP.

METHODS

The expression of most suitable reference genes and of PAD2 and PAD4 was assessed by qPCR. Analysis of DNA methylation was performed by bisulfite method.

RESULTS

The comparison of PAD2 expression level in PBMCs from patients with MS vs. healthy donors showed that, as well as in the white matter of MS patients, the enzyme is significantly upregulated in affected subjects. Methylation pattern analysis of a CpG island located in the PAD2 promoter showed that over-expression is associated with promoter demethylation.

CONCLUSION

Defective regulation of PAD2 in the periphery, without the immunological shelter of the blood-brain barrier, may contribute to the development of the autoimmune responses in MS.

Poly(ADP-ribosyl)ation affects stabilization of Che-1 protein in response to DNA damage

Poly(ADP-ribose) polymerase 1 (PARP-1) catalyzes a post-translational modification that plays a crucial role in coordinating the signalling cascade in response to stress stimuli. During the DNA damage response, phosphorylation by ataxia telangiectasia mutated (ATM) kinase and checkpoint kinase Chk2 induces the stabilization of Che-1 protein, which is critical for the maintenance of G2/M arrest. In this study we showed that poly(ADP-ribosyl)ation, beyond phosphorylation, is involved in the regulation of Che-1 stabilization following DNA damage. We demonstrated that Che-1 accumulation upon doxorubicin treatment is reduced after the inhibition of PARP activity in HCT116 cells and in PARP-1 knock-out or silenced cells. In accordance, impairment in Che-1 accumulation by PARP inhibition reduced Che-1 occupancy at p21 promoter and affected the expression of the corresponding gene. Epistasis experiments showed that the effect of poly(ADP-ribosyl)ation on Che-1 stabilization is independent from ATM kinase activity. Indeed we demonstrated that Che-1 protein co-immunoprecipitates with ADP-ribose polymers and that PARP-1 directly interacts with Che-1, promoting its modification in vitro and in vivo.

Ascaris Lumbricoides infestation and intestinal MZBCL: a surgical and radiological perspective

Ascaris Lumbricoides is the most common worm found in human beings and it is the largest of the intestinal nematodes parasitizing humanity. The most common complication of Ascariasis is mechanical bowel obstruction caused by a large number of worms. Bowel obstruction can also be caused by various toxins released by the worms. A large worm bolus can also cause volvulus or intussusception. We report a case of Intestinal Obstruction due to an Ileal MZBCL in an Ascaris. Lumbricoides infestation setting.

Dematin, a component of the erythrocyte membrane skeleton, is internalized by the malaria parasite and associates with Plasmodium 14-3-3

The malaria parasite invades the terminally differentiated erythrocytes, where it grows and multiplies surrounded by a parasitophorous vacuole. Plasmodium blood stages translocate newly synthesized proteins outside the parasitophorous vacuole and direct them to various erythrocyte compartments, including the cytoskeleton and the plasma membrane. Here, we show that the remodeling of the host cell directed by the parasite also includes the recruitment of dematin, an actin-binding protein of the erythrocyte membrane skeleton and its repositioning to the parasite. Internalized dematin was found associated with Plasmodium 14-3-3, which belongs to a family of conserved multitask molecules. We also show that, in vitro, the dematin-14-3-3 interaction is strictly dependent on phosphorylation of dematin at Ser(124) and Ser(333), belonging to two 14-3-3 putative binding motifs. This study is the first report showing that a component of the erythrocyte spectrin-based membrane skeleton is recruited by the malaria parasite following erythrocyte infection.

Validation of suitable internal control genes for expression studies in aging

Quantitative data from experiments of gene expression are often normalized through levels of housekeeping genes transcription by assuming that expression of these genes is highly uniform. This practice is being questioned as it becomes increasingly clear that the level of housekeeping genes expression may vary considerably in certain biological samples. To date, the validation of reference genes in aging has received little attention and suitable reference genes have not yet been defined. Our aim was to evaluate the expression stability of frequently used reference genes in human peripheral blood mononuclear cells with respect to aging. Using quantitative RT-PCR, we carried out an extensive evaluation of five housekeeping genes, i.e. 18s rRNA, ACTB, GAPDH, HPRT1 and GUSB, for stability of expression in samples from donors in the age range 35-74 years. The consistency in the expression stability was quantified on the basis of the coefficient of variation and two algorithms termed geNorm and NormFinder. Our results indicated GUSB be the most suitable transcript and 18s the least for accurate normalization in PBMCs. We also demonstrated that aging is a confounding factor with respect to stability of 18s, HPRT1 and ACTB expression, which were particularly prone to variability in aged donors.