Role of chromosomal imbalances in the pathogenesis of DSD: A retrospective analysis of 115 prenatal samples.

Differences of sex development (DSDs) are a group of congenital conditions characterized by a discrepancy between chromosomal, gonadal, and genital sex development of an individual, with significant impact on medical, psychological and reproductive life. The genetic heterogeneity of DSDs complicates the diagnosis and almost half of the patients remains undiagnosed. In this context, chromosomal imbalances in syndromic DSD patients may help to identify new genes implicated in DSDs. In this study, we aimed at describing the burden of chromosomal imbalances including submicroscopic ones (copy number variants or CNVs) in a cohort of prenatal syndromic DSD patients, and review their role in DSDs. Our patients carried at least one pathogenic or likely pathogenic chromosomal imbalance/CNV or low-level mosaicism for aneuploidy. Almost half of the cases resulted from an unbalanced chromosomal rearrangement. Chromosome 9p/q, 4p/q, 3q and 11q anomalies were more frequently observed. Review of the literature confirmed the causative role of CNVs in DSDs, either in disruption of known DSD-causing genes (SOX9, NR0B1, NR5A1, AR, ATRX, …) or as a tool to suspect new genes in DSDs (HOXD cluster, ADCY2, EMX2, CAMK1D, …). Recurrent CNVs of regulatory elements without coding sequence content (i.e. duplications/deletions upstream of SOX3 or SOX9) confirm detection of CNVs as a mean to explore our non-coding genome. Thus, CNV detection remains a powerful tool to explore undiagnosed DSDs, either through routine techniques or through emerging technologies such as long-read whole genome sequencing or optical genome mapping.

[Cytogenetics profiles of renal carcinoma]. / Cytogénétique des carcinomes rénaux.

Renal carcinomas are histologically and prognostically heterogeneous. Genomic as well as chromosomal studies of these tumors have permitted a better comprehension of molecular mechanisms implicated in their development and progression. The most frequent histological subtypes are characterized by recurrent cytogenetic abnormalities, such as the loss of the chromosome 3 short arm involving a VHL gene copy in clear cell renal carcinomas, or trisomies 7 and 17 in papillary renal cell carcinomas. New histological subtypes like renal carcinomas associated with Xp11.2 translocations have also been individualized. Besides diagnosis, some chromosomal aberrations like the loss of a short arm of chromosome 9 in different renal carcinoma histological subtypes have a worse prognostic impact. The identification of chromosomal shuffles contributes in backing histological diagnosis and in precising the individual prognosis of patients. This review describes chromosomal abnormalities associated to renal carcinomas and their impact for an accurate classification of these tumors and the evaluation of their prognosis.

[Renin-angiotensin system and urological cancers]. / Système rénine-angiotensine et cancers urologiques.

INTRODUCTION: A controversy animates the literature on the potential role of the renin-angiotensin system (RAS) in tumorogenesis. The objective of this review was to determine the involvement of this pathway in cancer, and more specifically in urological cancers. MATERIAL AND METHOD: We made a systematic review of articles referenced in Pubmed, using the following keywords alone or combined: cancer, renin, angiotensin, VEGF, AT1R, antagonists of angiotensin-2 receptors, inhibitors of angiotensinogen converting. RESULTS: Many types of cancers overexpress AT1-R in their tumoral tissues (breast, stomach, bladder, astrocytoma, glioblastoma, ovary, uterus, pancreas, kidney, prostate, adrenal gland). Ang-II can induce VEGF-A expression and promote neoangiogenesis, but also can trigger different molecular pathways involved in cell proliferation or inhibit apoptosis. Several xenograft murin models demonstrated anti-tumoral efficacy of RAS blockers, alone or using combined therapies, targeting angiogenesis and slowing down tumor growth. Retrospective studies in patients have also revealed a better progression-free survival and a better response to therapies in those treated with RAS blockers. CONCLUSION: Many data seem to demonstrate the involvement of the RAS in carcinogenesis, as well as anti-tumoral effect of RAS blockers in addition to anti-cancer treatments. Clinical data are now expected to confirm these experimental findings.

Overexpression of the polarity protein PAR-3 in clear cell renal cell carcinoma is associated with poor prognosis.

The partition-defective 3 (PAR-3) protein is implicated in the development and maintenance of cell polarity and is associated with proteins that mediate the changes in cytoskeleton organization required for cell polarity establishment. In this work, we used two original primary cell lines (R-180 and R-305) derived from clear cell Renal Cell Carcinoma (ccRCC) surgical specimens of a patient with unfavorable clinical course (R-180 cells) and a patient with favorable prognosis (R-305 cells) to identify genetic and molecular features that may explain the survival difference of the two patients. The cytogenetic analysis of these cell lines revealed that the PARD3 gene was amplified only in the R-180 cell line that was derived from an aggressive ccRCC. PARD3 gene amplification was associated with overexpression of the encoded protein and altered cytoskeleton organization. Consistently, PARD3 knockdown in R-180 cells restored the cytoskeleton organization and reduced cell migration in comparison to non-transfected cells. Immunohistochemical analysis of ccRCC samples from a cohort of 96 patients with a follow-up of 6 years revealed that PAR-3 overexpression was correlated with poor survival. Our results suggest that PAR-3 has a role in the clinical aggressiveness of ccRCC, possibly by promoting cell migration.

[Klinefelter syndrome: spermatogenesis and quality of gametes]. / Syndrome de Klinefelter : qualité des gamètes et spermatogenèse.

Klinefelter syndrome is defined by the presence of a supernumerary X chromosome in a phenotypic male. It is the most frequent gonosomic anomaly in infertile men with an incidence of 0.1 to 0.2% in newborn males. The presence of an additional X chromosome induces spermatogenic failure but when gametes are present, they are usually normal. The risk of transmission of the chromosomal anomaly remains low. In the literature, only one 47,XXY foetus resulting from more than a hundred births from fathers with Klinefelter syndrome, has been reported. One can estimate, that a TESE performed in half of the patients with non-mosaic 47,XXY will be positive and may enable IVF/ICSI to be achieved.

Angiotensin-2 receptors (AT1-R and AT2-R), new prognostic factors for renal clear-cell carcinoma?

BACKGROUND: The growth factor Angiotensin-2 signals through Angiotensin receptor type 1 (AT1-R) in a broad range of cell types and tumours and through the type-2 receptor (AT2-R) in a more restricted group of cell types. Although numerous forms of cancer have been shown to overexpress AT1-R, expression of AT1-R and AT2-R by human renal clear-cell carcinoma (RCCC) is not well understood. In this study, the expression of both angiotensin receptors was quantified in a retrospective series of RCCC and correlated with prognostic factors. METHODS: Angiotensin receptor type 1 and AT2-R expressions were quantified on tumour tissues by immunohistochemistry (IHC), western blot and quantitative reverse transcriptase PCR (qRT-PCR). IHC results were correlated to Fuhrman's grade and patient progression-free survival (PFS). RESULTS: A total of 84 RCCC were analysed. By IHC, AT1-R and AT2-R were expressed to a greater level in high-grade tumours (AT1-R: P<0.001, AT2-R: P<0.001). Univariate analysis showed a correlation between PFS and AT1-R or AT2-R expression (P=0.001). By multivariate analysis, only AT2-R expression correlated with PFS (HR 1.021, P=0.006) and cancer stage (P<0.001). By western blot, AT1-R and AT1-R were also found to be overexpressed in higher Fuhrman's grade (P<0.01 and P=0.001 respectively). By qRT-PCR, AT1-R but not AT2-R mRNA were downregulated (P=0.001 and P=0.118, respectively). CONCLUSION: Our results show that AT1-R and AT2-R proteins are overexpressed in the most aggressive forms of RCCC and that AT2-R expression correlates with PFS. AT1-R or AT2-R blockage could, therefore, offer novel directions for anti-RCCC therapy.

[Optimized protocols for interphase FISH analysis of imprints and sections using split signal probes]. / Application de la technique de FISH interphasique avec des sondes encadrantes dites de <> à différents types de préparations histologiques et cytologiques.

Fluorescent in situ hybridization (FISH) analysis is a molecular technique allowing the detection of recurrent translocations in cancer. Several hybridization protocols were assayed in order to evaluate their performances for interphase FISH analysis of histological sections and imprints using split probes. Adult and foetal lymphoid tissues were selected. Touch imprints of fresh (EF) or frozen (EC) tissues, sections (CF) and isolated nuclei (NI) of formol-fixed paraffin-embedded tissues were performed. The cut-off values of the IGH, IGlambda, BCL-2, BCL-6, CCND1 and MYC DNA FISH split signal probes were calculated for adult reactive lymph nodes on the different histological preparations (EC, CF, CC, NI) and on several tissues for the IGH and BCL-6 probes. In reactive lymph nodes, the cut-off values of the probes were between 3 and 13% and found independent of the preparation type. Conversely, slight but significant variations of the cut-off level were observed when different foetal control tissues were assayed with the same probe set. Finally, this study provided optimized-protocols for FISH analysis of either fresh/frozen imprints or formalin-fixed paraffin-embedded sections using split signal DNA probes.

Blastoid and common variants of mantle cell lymphoma exhibit distinct immunophenotypic and interphase FISH features.

AIMS: The recognition of blastoid variant (BV) of mantle cell lymphoma (MCL) is based on morphological criteria. Our aim was to analyse 18 MCL cases including four BV-MCL for their clinicopathological features, proliferation index, cyclin D1 and CDK4 expression and interphase fluorescence in-situ hybridization (FISH) pattern. METHODS AND RESULTS: BV-MCL versus common MCL was characterized by a shorter overall duration of response after first-line therapy (11 months versus 28 months) and shorter overall survival (20 months versus 42 months). Interphase FISH showed a t(11;14) fusion pattern in all MCL tested cases. However, the four blastoid cases were characterized by extra copies of CCND1 signals. Using additional probes of chromosomes 11, 18, 21, these signals were shown to be the result of hypotetraploidy and not of a specific amplification of the normal or the translocated CCND1 allele. Moreover, the BV-MCL cases were characterized by a combined high percentage of cells expressing cyclin D1 and/or CDK4 with a proliferation (MIB-1-Ki67) index above 50%. Such features allowed the recognition of areas of large cell transformation in the case of secondary BV-MCL. CONCLUSIONS: Since distinction between BV and common MCL is of clinical relevance, our data underline the need to add phenotypic and cytogenetic criteria to cytomorphology for a better recognition of BV-MCL.

[Spectral karyotyping (SKY) principle, avantages and limitations]. / Le caryotype spectral (SKY): principe, avantages et limites en cytogénétique constitutionnelle et tumorale.

Banding karyotype is a routine technique, which allows the identification of numerous aneusomy and/or aneuploïdy in congenital diseases and cancers. However, this analysis fails to detect small or complex chromosome rearrangements. Molecular cytogenetic techniques like fluorescence in situ hybridization (FISH) analysis can overlap these limitations. Particularly, multicolor karyotyping by spectral karyotyping (SKY) may rectify or precise the conventional karyotype results. With two examples, we present here, the principle, the indications and the limits of this technique for constitutional and cancer chromosomal abnormalities characterization. Moreover, we present an easy way to build efficient sky probes with a best sensitivity than the probes classically used.

[Interphase FISH analysis of frozen or fixed tissues for the detection of t(11;14) (q13;q32) in mantle cell lymphoma]. / Analyse par FISH interphasique de tissus congelés ou fixés pour la détection de la t(11;14)(q13;q32) dans les lymphomes du manteau.

Cytogenetic analyses have revealed that mantle cell lymphomas (MCL) are closely associated with the t(11;14)(q13;q32). This translocation juxtaposes the immunoglobulin heavy chain gene (IGH) sequences with the BCL-1 locus, leading to up-regulation of the CCND1 gene and consequently to an overexpression of cyclin D1 protein. We studied 27 MCL with characteristic morphological and immunological (CD5+, CD10-, CD20+, CD23-) features and 2 controls (reactionnal lymphadenitis) to evaluate the feasibility and the interest of FISH analysis on interphase cells from frozen or paraffin-embedded tissues. Sections (CC) and touch preparations (EC) of frozen tissues and sections of paraffin-embedded tissues (CF) were successfully hybridized with the Vysis LSI IgH/CCND1 dual color dual fusion translocation probe. The touch preparations presented a lower cellularity than sections, therefore allowing an easier analysis. Hybridization spots intensities were found stronger in CC and EC than in CF. The percentages of t(11;14) positive cells were similar in CC, EC and CF from a same patient. The percentage of non hybridized cells, analogous in CC and EC, was higher in CF. However, the CF were directly analysed on microscope without the need of any numerical picture treatment. The t(11;14) was detected in all the cases (27/27) and positive cells percentages were always higher than the probe cut-off (5%). The FISH analysis on interphase cells appears a performing and rapid technique to detect t(11;14) in MCL on both frozen and paraffin-embedded tissue, thus extending its practical and diagnostic use.

Study of apoptosis-related responses of leukemic blast cells to in vitro anthracycline treatment.

Anthracyclines trigger an apoptotic cell death but their molecular targets are not totally explored. We investigated the apoptotic response of blast cells and lymphocytes from medullary samples of 31 de novo acute leukemia. Mononuclear cells were treated in vitro by therapeutic concentrations of either daunorubicin (DNR) or idarubicin (IDA) for 1 h, washed and cultured for 18 h. A multivariate analysis using flow cytometry and a CD45 gating on lymphocytes and blast cells was performed. DNR and IDA induced a Fas enhancement on both leukemic and normal cells. In blast cells the DEVDases were activated and the caspase 3 was cleaved in relation to phosphatidyl serine exposure, showing a caspase-dependent pathway in anthracycline-induced apoptosis. Apoptotic percentages were always higher for blast cells than for lymphocytes, confirming that anthracycline toxicity mainly affected tumor cells. Moreover, drug-induced apoptosis was not related to spontaneous apoptosis, suggesting that variations in response intensities were due to individual variations of sensitivity rather than to programmed life span time. The apoptotic response of P-glycoprotein-expressing blast cells was not significant, giving biological argument for the poor prognosis of multidrug resistance leukemia. Finally, Fas induction and anthracycline-induced apoptosis on blast cells were significantly higher when a complete remission was achieved, thus shedding light on potential new prognostic factors in acute leukemia.

Flow cytometry detection of caspase 3 activation in preapoptotic leukemic cells.

BACKGROUND: Procaspase 3 is a constitutive proenzyme that is activated by cleavage during apoptosis. The resulting enzyme is able to cleave several target proteins after the second aspartate of a DEVD sequence common to all the substrates of caspases 3 and 7 (DEVDase). Because active caspase 3 is a common effector in several apoptotic pathways, it may be a good marker to detect (pre-)apoptotic cells by flow cytometry (FCM). Materials and Methods Apoptosis was induced in U937 or bone marrow mononuclear cells by daunorubicin (DNR), idarubicin (IDA), or camptothecin (CAM). Viable and apoptotic cells were sorted by FCM on the basis of either fluorescein isothiocyante (FITC)-annexin V binding or DiOC6(3) accumulation. DEVDase activity was measured in sorted populations by spectrofluorometry. Cleaved caspase 3 was labeled in situ with phycoerythrin (PE)-conjugated anti-activated caspase 3 antibodies and analyzed by FCM. RESULTS: DEVDase activity was detected in sorted viable CAM- and DNR-treated U937 cells, demonstrating that a partial caspase activation occurred earlier than phosphatidyl-serine exposure and mitochondrial membrane potential dissipation. The presence of a low amount of active caspase 3 in the treated viable cells was confirmed in situ with PE-conjugated anti-active caspase 3 antibodies. The same antibody was used in combination with FITC-annexin V and CD45-PC5 to study caspase 3 activation in acute leukemia blast cells after in vitro DNR and IDA treatment. Both anthracyclines induced a caspase 3-dependent apoptosis that was more efficient in blast cells than in contaminating lymphocytes. CONCLUSIONS: These results demonstrate that anti-active caspase 3 labeling can be an alternative to fluorogenic substrates to efficiently detect early apoptosis by FCM in heterogeneous samples. They also confirm that anthracyclines induce blast cell apoptosis by a caspase 3-dependent pathway.

Early transitory rise in intracellular pH leads to Bax conformation change during ceramide-induced apoptosis.

Ceramide can induce apoptosis through a caspase independent pathway. Bax has been described as able to kill cells in the absence of caspase activity, therefore we measured Bax in situ during ceramide-induced apoptosis using anti-Bax antibodies and flow cytometry analysis. An early (<30 min) increase in Bax labeling was observed after the addition of several ceramide species to several hemopoietic-related cell types. On U937, this increase was not due to antigens synthesis or processing, but rather an increased accessibility or reactivity of Bax antigens for antibodies. This increased immuno-reactivity of Bax was not inhibited by Z-VAD-fmk nor leupeptin, and preceded nuclear fragmentation by several hours. Such an increase in immuno-reactivity was also observed after Fas ligation, but it occurred later (>2 h) accompanying nuclear apoptosis, and was inhibited by Z-VAD-fmk. Bax immuno-reactivity was found to be related to intracellular pH (pHi), and C2-Ceramide (C2-Cer) induced a very early (<10 min) transitory increase in pHi. Both Bax immunoreactivity and pHi increases were dependent on the mitochondrial permeability transition pore (PTP) status. It was concluded from these results that C2-Cer induced a transitory increase in pHi in relation to the PTP. This rise in pHi led to conformational changes in Bax which could be responsible for further apoptosis in the C2-Cer pathway while it was a consequence of caspase activation in the Fas pathway.

Synthesis of Bcl-2 in response to anthracycline treatment may contribute to an apoptosis-resistant phenotype in leukemic cell lines.

BACKGROUND: Some forms of chemoresistance in leukemia may start from failure of tumour cells to successfully undergo apoptosis and Bcl-2 may play a role in this defect. Therefore, we evaluated the Bcl-2 content and synthesis in relation with the apoptotic potential in leukemic cell lines after anthracycline treatment. METHODS: U937, HL60, and K562 cells and their drug resistant (DR) variants were treated with varying concentrations of Idarubicin (IDA). Apoptosis was evaluated by fluorescence microscopy after acridine orange staining. Bcl-2 and Bax content were evaluated either by flow cytometry after indirect immunolabelling or by Western blot. RESULTS: High Bcl-2 contents were not related to a poor ability to undergo apoptosis in U937, HL60, K562 and their DR variants. IDA induced a concentration-dependent increase in Bcl-2 content in all cell lines as long as they do not perform apoptosis. Enhanced Bcl-2 expression was inhibited by cycloheximide, actinomycin D, or antisense oligonucleotide directed against bcl-2 mRNA. Bcl-2 expression was also increased in the resistant U937 variant after serum deprivation or C2-ceramide treatment. The synthesis of Bcl-2 led to an increased Bcl-2/Bax ratio solely in the cells with an apoptosis-resistance phenotype. CONCLUSIONS: These data suggest that exposure to IDA induces Bcl-2 expression in leukemic cell lines, and that this mechanism could contribute to apoptosis resistance and participate in the acquisition of chemoresistance. They also confirm that the evolution of the Bcl-2/Bax ratio reflects apoptotic ability better than the steady state level of Bcl-2 expression.

Flow cytometric analysis of mitochondrial activity in situ: application to acetylceramide-induced mitochondrial swelling and apoptosis.

Changes in mitochondrial matrix volume were studied both on isolated mitochondria and in situ on CHME 5 human microglia and monoblastoid U 937 cells using multiparametric flow cytometric analysis. The use of specific effectors of mitochondrial activity (oligomycin and KCN) allowed the demonstration, on whole cells, of a strict correlation between light scattering and mitochondrial volume changes: mitochondrial swelling induced a concomitant increase in forward scattering, and decrease in side scattering of the cell population. The technique was applied to the study of the early phases of acetyl-ceramide-induced apoptosis, which has been associated with mitochondrial dysfunction in several cellular systems. Acetyl-ceramide caused a marked swelling of isolated rat liver mitochondria. Scatter modifications were also observed in both cell lines during the first hour of incubation with acetylceramide and were accompanied by an increase in DiOC6 (3) fluorescence. The results imply that mitochondrial volume changes can be followed using flow cytometry and eventually used to assist in the interpretation of mitochondrial membrane potential variations obtained from fluorescence measurements. By applying this technique to 2 different cell lines, we demonstrated that mitochondrial swelling occurs during the early phases of acetyl-ceramide treatment, but that the induction of apoptosis is cell type-dependent.