Cyclic AMP induces reversible EPAC1 condensates that regulate histone transcription.

The second messenger cyclic AMP regulates many nuclear processes including transcription, pre-mRNA splicing and mitosis. While most functions are attributed to protein kinase A, accumulating evidence suggests that not all nuclear cyclic AMP-dependent effects are mediated by this kinase, implying that other effectors may be involved. Here we explore the nuclear roles of Exchange Protein Activated by cyclic AMP 1. We find that it enters the nucleus where forms reversible biomolecular condensates in response to cyclic AMP. This phenomenon depends on intrinsically disordered regions present at its amino-terminus and is independent of protein kinase A. Finally, we demonstrate that nuclear Exchange Protein Activated by cyclic AMP 1 condensates assemble at genomic loci on chromosome 6 in the proximity of Histone Locus Bodies and promote the transcription of a histone gene cluster. Collectively, our data reveal an unexpected mechanism through which cyclic AMP contributes to nuclear spatial compartmentalization and promotes the transcription of specific genes.

Analysis and pharmacological modulation of senescence in human epithelial stem cells.

Human epithelial stem cells (ESCs) are characterized by long-term regenerative properties, much dependent on the tissue of origin and varying during their lifespan. We analysed such variables in cultures of ESCs isolated from the skin, conjunctiva, limbus and oral mucosa of healthy donors and patients affected by ectrodactyly-ectodermal dysplasia-clefting syndrome, a rare genetic disorder caused by mutations in the p63 gene. We cultured cells until exhaustion in the presence or in the absence of DAPT (γ-secretase inhibitor; N-[N-(3, 5-difluorophenacetyl)-L-alanyl]-S-phenylglycine T-butyl ester). All cells were able to differentiate in vitro but exhibited variable self-renewal potential. In particular, cells carrying p63 mutations stopped prematurely, compared with controls. Importantly, administration of DAPT significantly extended the replicative properties of all stem cells under examination. RNA sequencing analysis revealed that distinct sets of genes were up- or down-regulated during their lifetime, thus allowing to identify druggable gene networks and off-the-shelf compounds potentially dealing with epithelial stem cell senescence. These data will expand our knowledge on the genetic bases of senescence and potentially pave the way to the pharmacological modulation of ageing in epithelial stem cells.

The displacement of frataxin from the mitochondrial cristae correlates with abnormal respiratory supercomplexes formation and bioenergetic defects in cells of Friedreich ataxia patients.

Friedreich ataxia (FRDA) is a neurodegenerative disease resulting from a severe decrease of frataxin (FXN). Most patients carry a GAA repeat expansion in both alleles of the FXN gene, whereas a small fraction of them are compound heterozygous for the expansion and a point mutation in the other allele. FXN is involved in the mitochondrial biogenesis of the FeS-clusters. Distinctive feature of FRDA patient cells is an impaired cellular respiration, likely due to a deficit of key redox cofactors working as electrons shuttles through the respiratory chain. However, a definite relationship between FXN levels, FeS-clusters assembly dysregulation and bioenergetics failure has not been established. In this work, we performed a comparative analysis of the mitochondrial phenotype of cell lines from FRDA patients, either homozygous for the expansion or compound heterozygotes for the G130V mutation. We found that, in healthy cells, FXN and two key proteins of the FeS-cluster assembly machinery are enriched in mitochondrial cristae, the dynamic subcompartment housing the respiratory chain. On the contrary, FXN widely redistributes to the matrix in FRDA cells with defects in respiratory supercomplexes assembly and altered respiratory function. We propose that this could be relevant for the early mitochondrial defects afflicting FRDA cells and that perturbation of mitochondrial morphodynamics could in turn be critical in terms of disease mechanisms.

Acute promyelocytic leukemia with a cryptic insertion of RARA into PML on chromosome 15 due to uniparental isodisomy: A case report.

Acute promyelocytic leukemia is a myeloid disorder that is characterized by the specific t(15;17) variant in ~98% of cases. The typical hypergranular and microgranular or hypogranular types exist, and are frequently associated with disseminated intravascular coagulopathy. Rare cases of promyelocytic leukemia-retinoic acid receptor α (PML-RARA) fusion without the reciprocal RARA-PML have been reported in cytogenetically normal samples. Conversely, fluorescence in situ hybridization (FISH) analysis has revealed a cryptic insertion of the RARA gene into the PML gene on chromosome 15. The current study reports a unique case with a normal karyotype and molecular evidence of the PML-RARA short isoform 3-fusion transcript, with FISH analysis revealing two fusion signals on the two copies of chromosome 15, but absence of the reciprocal on the two copies of chromosome 17. This finding raised the hypothesis of chromosome 15 uniparental isodysomy as consequence of normal chromosome 15 loss and duplication of the rearranged chromosome, as supported by polymorphic loci molecular analysis. The clinical, cytogenetic and molecular characterization of this case are presented and discussed in the present study.

45,X product of conception after preimplantation genetic diagnosis and euploid embryo transfer: evidence of a spontaneous conception confirmed by DNA fingerprinting.

BACKGROUND: Preimplantation genetic screening (PGS) provides an opportunity to eliminate a potential implantation failure due to aneuploidy in infertile couples. Some studies clearly show that twins following single embryo transfer (SET) can be the result of a concurrent natural conception and an incidence as high as 1 in 5 twins has been reported. In our case PGS was performed on trophectoderm (TE) biopsies by quantitative polymerase chain reaction (qPCR). The product of conception (POC) was cytogenetically investigated after selection of the placental villi by means of the direct method. Molecular cytogenetic characterization of the POC was performed by fluorescence in situ hybridization (FISH) and array-comparative genomic hybridization (a-CGH) analyses. To investigate the possibility of a spontaneous conception, a panel of 40 single nucleotide polymorphisms (SNPs) was used to compare genetic similarity between the DNA of the POC and the DNA leftover of the TE biopsy. FINDINGS: We describe a 36-year old infertile woman undergoing PGS who had a spontaneous abortion after a single euploid embryo transfer on a spontaneous cycle. The POC showed a 45,X karyotype confirmed by FISH and a-CGH. DNA fingerprinting demonstrated a genetic similarity of 75 % between the DNA of the POC and TE biopsy, consistent with a sibling status. All supernumerary euploid embryos were also tested showing a non-self relationship with the POC, excluding a mix-up event at the time of fetal embryo transfer. CONCLUSIONS: DNA fingerprinting of the transferred blastocyst and POC, confirmed the occurrence of a spontaneous conception. This case challenges the assumption that a pregnancy after assisted reproductive technology (ART) is always a result of ART, and strengthens the importance to avoid intercourses during PGS and natural transfer cycles. Moreover, cytogenetic analysis of the POCs is strongly recommended along with fingerprinting children born after PGS to see what the concordance is between the embryo transferred and the resultant child.

Lung cancer in which the hypothesis of multi-step progression is confirmed by array-CGH results: A case report.

The pathogenesis of lung cancer has not been fully elucidated and biological markers acting as predictors of tumor evolution and aggressiveness remain unidentified. The multi-step hypothesis, suggesting a progression from adenomatous hyperplasia (AAH) to adenocarcinoma (AC) through bronchioalveolar carcinoma (BAC), was highlighted in a previous cytogenetic study performed in a single case. The present study reports the results of an array-comparative genomic hybridization (a-CGH) analysis performed on the DNA obtained from the previously reported case that presented AAH, BAC and AC in one lung. The a-CGH results confirm and support the previous cytogenetic observations with new data, clearly supporting the hypothesis of a multi-step carcinogenic process in the lung.

Level of HER2/neu amplification in primary tumours and metastases in HER2-positive breast cancer and survival after trastuzumab therapy.

BACKGROUND: The level of HER2/neu amplification may vary widely in breast cancers with HER2/neu alteration. The clinical significance of this phenomenon is still unclear. This study was aimed to explore the level of HER2/neu amplification in primary tumours and metastases in HER2-positive metastatic breast cancer (MBC) and its potential impact on survival after a trastuzumab-containing therapy. METHODS: We retrospectively identified MBC patients treated with a trastuzumab-containing therapy and performed dual-colour FISH on tumour samples from either primary tumour and/or metastasis in a central laboratory. RESULTS: We retrieved 110 tumour samples from 91 patients and included 79 tumour samples (primary = 56; metastasis = 23) from 63 patients in the final analysis. We found higher level of HER2/neu amplification in the metastases than in the primary tumours (median HER2/CEP17 ratio: 10.5 vs. 7.0, respectively). In 69% of patients (n = 16) with two tumour samples, the level of HER2/neu amplification was higher in the metastasis than in the paired primary tumour (median HER2/CEP17 ratio: 10.9 vs. 8.3, respectively, p = 0.004). The incremental gain in level of HER2/neu amplification was associated with significantly shorter OS after trastuzumab-containing therapy (p = 0.023, HR 1.014, CI95%: 1.002-1.025). CONCLUSIONS: The level of HER2/neu amplification tends to increase from the primary tumour to the paired metastases in a significant proportion of patients with HER2-positive MBC. This phenomenon, although still not completely understood, could lead to a shorter OS after trastuzumab therapy.

Cytogenetic findings in lung cancer that illuminate its biological history from adenomatous hyperplasia to bronchioalveolar carcinoma to adenocarcinoma: A case report.

The biological and chronological evolution of lung cancer remain to be fully elucidated. A multi-step carcinogenesis hypothesis suggests a progression from atypical adenomatous hyperplasia (AAH) through bronchioalveolar carcinoma (BAC) to invasive adenocarcinoma (AC), but to date this has not been formally demonstrated. We report a case of a patient diagnosed by computed tomography (CT) with lung cancer in the superior right lobe who also presented with a pure ground-glass opacity (GGO) in the inferior lobe, while the middle lobe appeared normal. Following pneumonectomy, cytogenetic analysis successfully performed on spontaneous metaphases obtained by the direct method from samples of the three lung lobes showed the presence of three clonal cell populations, each progressively having increased karyotype complexity. Fluorescence in situ hybridization (FISH), performed using ALK (2p23) break probe and ALK/EML4 t(2;2);inv(2) fusion probe, showed a normal pattern for all specimens. Histological evaluation confirmed the presence of AC in the superior right lobe and classified the GGO lesion as BAC and the normal tissue of the middle lobe as AAH. To the best of our knowledge, this is the first case in which the cytogenetic study of spontaneous metaphases showed a clear clonal relationship among AC, BAC and AAH present simultaneously in different lobes of the same lung. This case appears to indicate that the entire lung was somehow predisposed to a neoplastic transformation starting with a diffuse AAH characterized by high proliferative activity. Moreover, the 5q13 region involved in the translocation shared by BAC and AC contains at least 4 genes encoding important regulators of the cell cycle that may be considered new molecular markers of lung cancer.

Fluorescent in situ hybridization (FISH) in the differential diagnosis of ground-glass opacities in the lung.

Computed tomographic (CT) screening for lung cancer has increased the detection rate of nodules manifesting as ground-glass opacities (GGOs). The natural history of this new entity it is not well known nor is the factors that influence the growth, progression and malignant potential. This genetic study was performed in order to identify molecular markers with possible diagnostic and prognostic significance to differentiate lesions with malignant or benign profiles. Ten pure GGO fresh samples and 5 specimens of normal lung tissue were cytogenetically investigated using a direct method and short-term cultures, and molecular analysis was performed using the 4-target FISH LAVysion kit for the detection of non-small cell lung cancer (NSCLC). Interestingly, all the karyotypes turned out to be normal both with the direct method and cultured cells, while in 3 out of 10 GGOs FISH analysis was abnormal for all the targets and in 2 cases only c-MYC amplification was observed. Karyotypes and FISH performed on the normal tissue samples gave normal results. Two of three FISH positive patients died, one had a relapse of the disease and at the last follow-up showed lung and bone metastases. Despite the small sample due to the rarity of pure GGOs, these preliminary results indicate that interphase FISH analyses are more informative than metaphase studies and might contribute clinically relevant information about the nature of these lesions.

Level of HER2/neu gene amplification as a predictive factor of response to trastuzumab-based therapy in patients with HER2-positive metastatic breast cancer.

To explore the clinical significance of the level of HER2/neu gene amplification in a homogenous cohort of 33 patients with HER2-positive metastatic breast cancer (MBC) and available tumor samples treated with a trastuzumab-based regimen, we retrospectively performed dual-color fluorescence in-situ hybridization test and correlated them for each patient with time-to-progression (TTP) and overall survival (OS). We obtained values of HER2/chromosome 17 centromere (CEP17) ratio ranging from 2.5 to 21 (median 7.2). At the Cox model there is indication that patients whose tumors have high-level HER2/CEP17 ratio have shorter TTP and OS than those with lower ratio, when treated with a trastuzumab-based regimen. Correlations do not reach the limits of statistical significance but no formal sample size calculation was performed due to the explorative nature of the study. If confirmed in larger cohorts of patients, HER2/CEP17 ratio could represent a reliable and economical predictor of response to trastuzumab-based therapy in MBC.

Administration of temozolomide during and after radiotherapy for newly diagnosed high-grade gliomas excluding glioblastoma multiforme.

Primary brain high-grade gliomas, excluding glioblastoma are rare and heterogeneous tumors, showing different characteristic mutations and a better prognosis than glioblastomas. The addition of chemotherapy to the radiotherapy in the newly diagnosed disease has not been established yet. We treated 9 patients with newly diagnosed tumors with temozolomide at 75 mg/m2 for 7 days a week during standard radiotherapy, followed by six cycles at 200 mg/m2 on days 1-5 every 28 days. Fluorescence in situ hybridization for the 1 p/19 q loss was performed in seven out of the 9 patients. With a median follow-up of 15 months (range, 8-50), eight patients are alive and one died from disease progression. Four patients had disease progression at 7, 15, 14 and 13 months from the diagnosis. The 1 p/19 q loss was found in 5 patients; three have no evidence of disease, one had partial disease remission and one disease progression. Toxicities included one discitis requiring treatment withdrawal and specific antibiotic therapy, and one transient grade 3 psoriasiform reaction. Based on this small series of patients, the addition of temozolomide to radiotherapy may be recommended.

Prenatal diagnosis of del(9)(p24): a sex reverse case.

BACKGROUND: We report on a fetus with sex reversal and del(9)(p24) consequent to a malsegregation of a maternal balanced complex translocation involving chromosomes 7, 9 and 11. METHODS: Fluorescence in situ hybridization (FISH) was performed in order to verify the presence of the SRY gene and the absence of DMRT1 and DMRT2 genes located in 9p24.3 region and frequently associated with sex reversal. RESULTS AND CONCLUSIONS: The prenatal karyotype revealed an unbalanced male fetus. The postmortem examination showed a malformed fetus with female external genitalia. Lack of DMRT1-2 genes established by FISH.

Unusual cytogenetic findings in a synovial sarcoma arising in the paranasal sinuses.

A fresh specimen from an intracranial tumor, which was histopatologically classified as a synovial sarcoma, was investigated cytogenetically. The direct method failed to give any information due to a lack of mitotic cells after treatment with 70% acetic acid, whereas 6-day cultures showed a 45,XY,del(6q),-10 karyotype. The histologic evaluation was consistent with a synovial sarcoma, which is well characterized from a cytogenetic perspective and involves a t(X;18)(p11;q11) in more than 95% of cases. Reverse-transcription polymerase chain reaction analysis did not show the presence of the SYT-SSX chimeric gene.