High Resolution Genome-Wide Analysis of Chromosomal Alterations in Burkitt's Lymphoma

Additional chromosomal abnormalities are currently detected in Burkitt's lymphoma. They play major roles in the progression of BL and in prognosis. The genes involved remain elusive. A whole-genome oligonucleotide array CGH analysis correlated with karyotype and FISH was performed in a set of 27 Burkitt's lymphoma-derived cell lines and primary tumors. More than half of the 145 CNAs<2 Mb were mapped to Mendelian CNVs, including GSTT1, glutathione s-transferase and BIRC6, an anti-apoptotic protein, possibly predisposing to some cancers. Somatic cell line-specific CNVs localized to the IG locus were consistently observed with the 244 K aCGH platform. Among 136 CNAs >2 Mb, gains were found in 1q (12/27), 13q (7/27), 7q (6/27), 8q(4/27), 2p (3/27), 11q (2/27) and 15q (2/27). Losses were found in 3p (5/27), 4p (4/27), 4q (4/27), 9p (4/27), 13q (4/27), 6p (3/27), 17p (3/27), 6q (2/27),11pterp13 (2/27) and 14q12q21.3 (2/27). Twenty one minimal critical regions (MCR), (range 0.04–71.36 Mb), were delineated in tumors and cell lines. Three MCRs were localized to 1q. The proximal one was mapped to 1q21.1q25.2 with a 6.3 Mb amplicon (1q21.1q21.3) harboring BCA2 and PIAS3. In the other 2 MCRs, 1q32.1 and 1q44, MDM4 and AKT3 appeared as possible drivers of these gains respectively. The 13q31.3q32.1 <89.58–96.81> MCR contained an amplicon and ABCC4 might be the driver of this amplicon. The 40 Kb 2p16.1 <60.96–61> MCR was the smallest gained MCR and specifically encompassed the REL oncogene which is already implicated in B cell lymphomas. The most frequently deleted MCR was 3p14.1 <60.43–60.53> that removed the fifth exon of FHIT. Further investigations which combined gene expression and functional studies are essential to understand the lymphomagenesis mechanism and for the development of more effective, targeted therapeutic strategies

From Chromosome to Gene by Mapping Chromosomal Abnormalities in Cancer in Order to Find Targeted Pharmaceutical Agents

Le cancer est désormais considéré comme une maladie génomique de la cellule. Les moyens d’étude de l’oncogénome étaient basés sur les différentes modalités du caryotype, peu résolutif. L’application des techniques de micromatrices d’oligonucléotides, notamment l’aCGH, a permis une avancée majeure dans la caractérisation des génomes des cancers.La première partie de notre travail a porté sur les lymphomes de Burkitt (LB), caractérisés par une translocation entre un gène d'immunoglobuline et MYC. L’étude portait sur 12 tumeurs primaires et 15 lignées cellulaires. L’aCGH (44K et 244K), concordait avec les cytogénétiques morphologique et moléculaire (FISH) sauf pour les translocations. Plus de la moitié des variations du nombre de copies (<2Mb) étaient des polymorphismes (CNV). Les anomalies pathologiques (CNA) (n=136) intéressaient les régions suivantes : gains 1q, 13q, 7q, 8q, 2p, 11q et 15q ; pertes 3p, 4p, 4q, 9p, 6p, 17p, 6q, 11pterp13 et 14q12q21.3. Vingt régions minimales critiques (MCR) d’une taille varie entre 0.07-71.36 Mb, étaient délimitées. Trois MCR étaient identifiées sur le 1q : 1q21.1q25.2, 1q32.1 et 1q44. La région proximale de 1q21.1q25.2 était le siège d’une amplification, contenant entre autres les gènes BCA2, PIAS, BCL9. L’étude par transcriptome, sur 15 lignées, a démontré la surexpression uniquement de BCL9, remanié dans les LAL B et faisant partie de la voie de signalisation de MYC. Sur la région 11q23.1, le gain intéressait le gène POU2AF1 dont le messager était élevé. La MCR 13q31.3q32.1 était le siège d’une amplification contenant ABCC4, et le polycistron miR17-92. La corrélation des résultats d’aCGH à ceux du transcriptome et du mirnome ont démontré une surexpression du miR17-92 qui contrôle le développement des lymphocytes B et intervient dans la voie de signalisation de MYC. Sur le 9p21.3, la perte emportait le locus p16INK4A/p15INK4B. Le transcriptome avait démontré une sous expression de p15INK4B. Le locus p16INK4A/p15INK4B contrôle les 2 voies majeures, pRB et p53.La seconde partie de notre travail a consisté à étudier 17 tumeurs congelées de carcinomes adénoïdes kystiques (CAK) par aCGH 44K. Les CNA étaient validées par FISH et/ou MLPA. L’expression protéique était étudiée par immunohistochimie. Les pertes excédaient les gains (41 versus 24). La t(6;9)(q23;p22) récurrente dans les CAK était indétectable car équilibrée. Dans un seul cas, le der(6)t(6;9) est probablement présent sur le profil aCGH. Les MCR les plus fréquentes (-6q22 et -6q24) n’incluaient pas 6q23. Treize MCR étaient identifiées. La MCR délétée en 8q impliquait le miR-124A2 qui régule les gènes CDK6 et MMP2. Sur le 9p21.3, le locus p16INK4A/p15INK4B était de nouveau perdu. Des gains isolés étaient observés au niveau des locus CCND1, KIT/PDGFRA/KDR, MDM2 et JAK2. Le gène MDM2, qui était amplifié sous forme de double minutes, est un élément clé de l’axe p16INK4A-ARF-p53.Pour la troisième partie de notre travail nous avons étudié 60 tumeurs primaires d’adénocarcinomes pulmonaires (AD) de non fumeur par aCGH (244K). Dans 50/60 tumeurs, le nombre de MCR était de 14. Cinq MCR contenaient un seul gène (MOCS2, NSUN3, KHDRBS2, SNTG1 et ST18). Une MCR gagnée, 5q35, contenait le gène NSD1. Une amplification, sous forme de HSR et mise en évidence par FISH, intéressait l’oncogène FUS. Une PCR quantitative avait permis de confirmer la surexpression FUS. A notre connaissance, c’est la première étude qui incrimine le gène FUS dans la carcinogenèse de l’AD du non-fumeur. D’autres gènes étaient également impliqués : ARNT, BCL9, CDK4, p15INK4B, EGFR, ERBB2, MDM2, MDM4, MET, MYC, NKX2-1 et KRAS. Un clustering non supervisé avait permis de dégager un groupe avec un gain de MYC ; un autre groupe caractérisé par la perte des gènes suppresseurs RB et WRN et un dernier groupe caractérisé par un gain 7p et 7q, et présentait une fréquence élevée de mutations de l’EGFR. Dans 10/60, le nombre de CNA était très rare et aucune MCR n’était détectée.Much of our current understanding of cancer is based on the hypothesis that it is a genetic disease, arising as a clone of cells that expand in an unregulated fashion because of somatically acquired mutations. High-throughput tools for nucleic acid characterization, such as array comparative genomic hybridization (aCGH), now provide the means to conduct comprehensive analyses of somatic anomalies in the oncogenome.In the first part of our work we have carried out a fine mapping of additional chromosomal anomalies in Burkitt lymphoma (BL). The hallmark of this disease is the translocation t(MYC;IG). We have applied whole-genome 244K and 44k oligonucléotides aCGH to 15 cells lines and 12 primary tumors of BL respectively. Karyotype and FISH analysis were used to validate aCGH results. As expected, all translocations remained undetectable with aCGH. More than half of the copy number alterations (CNAs) < 2 Mb were mapped to Mendelian CNVs, including GSTT1, and BIRC6. Somatic cell line-specific CNVs localized to the IG locus were consistently observed with the 244 K aCGH platform. Among 136 CNAs, gains were found in 1q, 13q, 7q, 8q, 2p, 11q and 15q. Losses were found in 3p, 4p, 4q, 9p, 13q, 6p, 17p, 6q,11pterp13 and 14q12q21.3. Twenty one minimal critical regions (MCR), (range 0.04–71.36 Mb), were delineated in tumors and cell lines. Three MCRs were localized to 1q: 1q21.1q25.2, 1q32.1 et 1q44. The proximal one was mapped to 1q21.1q25.2 with a 6.3 Mb amplicon (1q21.1q21.3) harboring BCA2, BCL9 and PIAS3. Only BCL9 high level transcrit was noted on oligonucleotide microarray gene expression that was done on 15 cells lines. BCL9, was implicated in a LAL B translocation t(1;14)(q21;q32) and it is a member of MYC pathway. The 13q31.3q32.1, 89.58–96.81 Mb MCR contained an amplicon with several genes. The miR-17-92 cluster, upregulated on mirnome analysis that was done on 15 cells lines, is the gene driver of 13q MCR. The miR-17-92 cluster is a member of MYC pathway. The 9p21.3 MCR harbored p16INK4A/p15INK4B locus which is downregulated. MYC activates ARF,a protein encodes by p16INK4A/p15INK4B locus. . On the second part of our work, a 44k aCGH was applied on 17 frozen adenoid cystic carcinoma (ACC) to delineate with a high resolution the CNA associated with ACC. aCGH results were validated with FISH and/or MLPA. Protein expression was screened with immunohistochemistry analysis. The translocation t(6;9)(q23;p23p24)/ MYB-NFIB recurrent in ACC, was not detected with aCGH. In one case, the der(6)t(6;9) was suspected in the aCGH pattern. There were recurrent gains at 7p15.2, 17q21–25, 22q11–13, and recurrent losses at 1p35, 6q22–25, 8q12–13, 9p21, 12q12–13, and 17p11–13. Thirteen MCR were detected. The recurrent deletion at 8q12.3–13.1 contained miRN124A2 gene, whose product regulates MMP2 and CDK6. The 9p21.3 MCR harbored p16INK4A/p15INK4B locus which was deleted. On 17p11p13, the MCR contained several genes and TP53 was deleted in 2 cases. The MDM2 gene, a member of p16INK4A-ARF-p53 pathway, was amplified and overexpressed in one case. Among the other unique CNAs, gains harbored CCND1, KIT/PDGFRA/KDR, and JAK2. On the third part of this these, a high-resolution 244K aCGH was conducted on 60 frozen lung adenocarcinoma (AD) of never smokers patients in order to establish a catalog of CNA. In 50/60 tumors, fourteen new MCR of gain or loss was noted. One larger MCR of gain contained NSD1.One focal amplification and nine gains contained FUS. NSD1 and FUS are oncogenes hitherto not known to be associated with lung cancer. FUS was over-expressed in 10 tumors with gain of 16p11.2 compared to 30 tumors without that gain. A FUS hsr was observed with FISH screening. FUS was over-expressed in 10 tumors with gain of 16p11.2 compared to 30 tumors without that gain. Other cancer genes present in aberrations included ARNT, BCL9, CDK4, p15INK4B, EGFR, ERBB2, MDM2, MDM4, MET, MYC, NKX2-1 and KRAS

Du chromosome au gène par un criblage global des altérations génomiques dans la malignité pour isoler de nouvelles cibles thérapeutiques

Much of our current understanding of cancer is based on the hypothesis that it is a genetic disease, arising as a clone of cells that expand in an unregulated fashion because of somatically acquired mutations. High-throughput tools for nucleic acid characterization, such as array comparative genomic hybridization (aCGH), now provide the means to conduct comprehensive analyses of somatic anomalies in the oncogenome.In the first part of our work we have carried out a fine mapping of additional chromosomal anomalies in Burkitt lymphoma (BL). The hallmark of this disease is the translocation t(MYC;IG). We have applied whole-genome 244K and 44k oligonucléotides aCGH to 15 cells lines and 12 primary tumors of BL respectively. Karyotype and FISH analysis were used to validate aCGH results. As expected, all translocations remained undetectable with aCGH. More than half of the copy number alterations (CNAs) < 2 Mb were mapped to Mendelian CNVs, including GSTT1, and BIRC6. Somatic cell line-specific CNVs localized to the IG locus were consistently observed with the 244 K aCGH platform. Among 136 CNAs, gains were found in 1q, 13q, 7q, 8q, 2p, 11q and 15q. Losses were found in 3p, 4p, 4q, 9p, 13q, 6p, 17p, 6q,11pterp13 and 14q12q21.3. Twenty one minimal critical regions (MCR), (range 0.04–71.36 Mb), were delineated in tumors and cell lines. Three MCRs were localized to 1q: 1q21.1q25.2, 1q32.1 et 1q44. The proximal one was mapped to 1q21.1q25.2 with a 6.3 Mb amplicon (1q21.1q21.3) harboring BCA2, BCL9 and PIAS3. Only BCL9 high level transcrit was noted on oligonucleotide microarray gene expression that was done on 15 cells lines. BCL9, was implicated in a LAL B translocation t(1;14)(q21;q32) and it is a member of MYC pathway. The 13q31.3q32.1, 89.58–96.81 Mb MCR contained an amplicon with several genes. The miR-17-92 cluster, upregulated on mirnome analysis that was done on 15 cells lines, is the gene driver of 13q MCR. The miR-17-92 cluster is a member of MYC pathway. The 9p21.3 MCR harbored p16INK4A/p15INK4B locus which is downregulated. MYC activates ARF,a protein encodes by p16INK4A/p15INK4B locus. . On the second part of our work, a 44k aCGH was applied on 17 frozen adenoid cystic carcinoma (ACC) to delineate with a high resolution the CNA associated with ACC. aCGH results were validated with FISH and/or MLPA. Protein expression was screened with immunohistochemistry analysis. The translocation t(6;9)(q23;p23p24)/ MYB-NFIB recurrent in ACC, was not detected with aCGH. In one case, the der(6)t(6;9) was suspected in the aCGH pattern. There were recurrent gains at 7p15.2, 17q21–25, 22q11–13, and recurrent losses at 1p35, 6q22–25, 8q12–13, 9p21, 12q12–13, and 17p11–13. Thirteen MCR were detected. The recurrent deletion at 8q12.3–13.1 contained miRN124A2 gene, whose product regulates MMP2 and CDK6. The 9p21.3 MCR harbored p16INK4A/p15INK4B locus which was deleted. On 17p11p13, the MCR contained several genes and TP53 was deleted in 2 cases. The MDM2 gene, a member of p16INK4A-ARF-p53 pathway, was amplified and overexpressed in one case. Among the other unique CNAs, gains harbored CCND1, KIT/PDGFRA/KDR, and JAK2. On the third part of this these, a high-resolution 244K aCGH was conducted on 60 frozen lung adenocarcinoma (AD) of never smokers patients in order to establish a catalog of CNA. In 50/60 tumors, fourteen new MCR of gain or loss was noted. One larger MCR of gain contained NSD1.One focal amplification and nine gains contained FUS. NSD1 and FUS are oncogenes hitherto not known to be associated with lung cancer. FUS was over-expressed in 10 tumors with gain of 16p11.2 compared to 30 tumors without that gain. A FUS hsr was observed with FISH screening. FUS was over-expressed in 10 tumors with gain of 16p11.2 compared to 30 tumors without that gain. Other cancer genes present in aberrations included ARNT, BCL9, CDK4, p15INK4B, EGFR, ERBB2, MDM2, MDM4, MET, MYC, NKX2-1 and KRAS.Le cancer est désormais considéré comme une maladie génomique de la cellule. Les moyens d’étude de l’oncogénome étaient basés sur les différentes modalités du caryotype, peu résolutif. L’application des techniques de micromatrices d’oligonucléotides, notamment l’aCGH, a permis une avancée majeure dans la caractérisation des génomes des cancers.La première partie de notre travail a porté sur les lymphomes de Burkitt (LB), caractérisés par une translocation entre un gène d'immunoglobuline et MYC. L’étude portait sur 12 tumeurs primaires et 15 lignées cellulaires. L’aCGH (44K et 244K), concordait avec les cytogénétiques morphologique et moléculaire (FISH) sauf pour les translocations. Plus de la moitié des variations du nombre de copies (<2Mb) étaient des polymorphismes (CNV). Les anomalies pathologiques (CNA) (n=136) intéressaient les régions suivantes : gains 1q, 13q, 7q, 8q, 2p, 11q et 15q ; pertes 3p, 4p, 4q, 9p, 6p, 17p, 6q, 11pterp13 et 14q12q21.3. Vingt régions minimales critiques (MCR) d’une taille varie entre 0.07-71.36 Mb, étaient délimitées. Trois MCR étaient identifiées sur le 1q : 1q21.1q25.2, 1q32.1 et 1q44. La région proximale de 1q21.1q25.2 était le siège d’une amplification, contenant entre autres les gènes BCA2, PIAS, BCL9. L’étude par transcriptome, sur 15 lignées, a démontré la surexpression uniquement de BCL9, remanié dans les LAL B et faisant partie de la voie de signalisation de MYC. Sur la région 11q23.1, le gain intéressait le gène POU2AF1 dont le messager était élevé. La MCR 13q31.3q32.1 était le siège d’une amplification contenant ABCC4, et le polycistron miR17-92. La corrélation des résultats d’aCGH à ceux du transcriptome et du mirnome ont démontré une surexpression du miR17-92 qui contrôle le développement des lymphocytes B et intervient dans la voie de signalisation de MYC. Sur le 9p21.3, la perte emportait le locus p16INK4A/p15INK4B. Le transcriptome avait démontré une sous expression de p15INK4B. Le locus p16INK4A/p15INK4B contrôle les 2 voies majeures, pRB et p53.La seconde partie de notre travail a consisté à étudier 17 tumeurs congelées de carcinomes adénoïdes kystiques (CAK) par aCGH 44K. Les CNA étaient validées par FISH et/ou MLPA. L’expression protéique était étudiée par immunohistochimie. Les pertes excédaient les gains (41 versus 24). La t(6;9)(q23;p22) récurrente dans les CAK était indétectable car équilibrée. Dans un seul cas, le der(6)t(6;9) est probablement présent sur le profil aCGH. Les MCR les plus fréquentes (-6q22 et -6q24) n’incluaient pas 6q23. Treize MCR étaient identifiées. La MCR délétée en 8q impliquait le miR-124A2 qui régule les gènes CDK6 et MMP2. Sur le 9p21.3, le locus p16INK4A/p15INK4B était de nouveau perdu. Des gains isolés étaient observés au niveau des locus CCND1, KIT/PDGFRA/KDR, MDM2 et JAK2. Le gène MDM2, qui était amplifié sous forme de double minutes, est un élément clé de l’axe p16INK4A-ARF-p53.Pour la troisième partie de notre travail nous avons étudié 60 tumeurs primaires d’adénocarcinomes pulmonaires (AD) de non fumeur par aCGH (244K). Dans 50/60 tumeurs, le nombre de MCR était de 14. Cinq MCR contenaient un seul gène (MOCS2, NSUN3, KHDRBS2, SNTG1 et ST18). Une MCR gagnée, 5q35, contenait le gène NSD1. Une amplification, sous forme de HSR et mise en évidence par FISH, intéressait l’oncogène FUS. Une PCR quantitative avait permis de confirmer la surexpression FUS. A notre connaissance, c’est la première étude qui incrimine le gène FUS dans la carcinogenèse de l’AD du non-fumeur. D’autres gènes étaient également impliqués : ARNT, BCL9, CDK4, p15INK4B, EGFR, ERBB2, MDM2, MDM4, MET, MYC, NKX2-1 et KRAS. Un clustering non supervisé avait permis de dégager un groupe avec un gain de MYC ; un autre groupe caractérisé par la perte des gènes suppresseurs RB et WRN et un dernier groupe caractérisé par un gain 7p et 7q, et présentait une fréquence élevée de mutations de l’EGFR. Dans 10/60, le nombre de CNA était très rare et aucune MCR n’était détectée

Biological characterization of two xenografts derived from human CUPs (carcinomas of unknown primary)

Abstract Background Carcinomas of unknown primary site (CUP) are epithelial malignancies revealed by metastatic lesions in the absence of any detectable primary tumor. Although they often adopt an aggressive clinical pattern, their basic biology remains poorly understood. Laboratory research on their biology have been hampered so far by the absence of cell lines representative of CUPs. Methods We attempted xenografts of CUP clinical specimens in immunodeficient mice and subsequent in vitro culture of transplanted malignant cells. Whenever possible, malignant xenografted or cultured cells were characterized by microsatellite genotyping, immunohistology, electron microscopy, multifish chromosome analysis and search of TP 53 gene mutations. Results Successful xenografts were achieved in 2 cases out of 4. One of them (Capi1) was lost after 3 passages whereas the other one (Capi3) has been adapted to in vitro culture and is currently available to the scientific community with reliable identification based on microsatellite genotyping. Both Capi1 and Capi3 have histological characteristics of adenocarcinomas and display intense expression of EMA, CEA and cytokeratin 7. Multifish chromosome analysis demonstrated a translocation involving chromosomes 4 and 21 in both specimens. Distinct rare missense mutations of the TP53 gene were detected in Capi1 (codon 312) and Capi3 (codon 181); the codon 181 mutation is consistent with a previously reported similar finding in a small series of CUP specimens. Finally, intense membrane expression of c-kit was recorded in Capi3. Conclusion Our data suggest that xenografted tumors can be obtained from a substantial fraction of CUP clinical specimens. The hypothesis of a preferential association of CUPs with TP 53 mutations of codon 181 deserves further investigations. The Capi3 cell line will be a useful tool for assessment of novel c-kit inhibitors.</p

Chromosomal minimal critical regions in therapy-related leukemia appear different from those of de novo leukemia by high-resolution aCGH.

Therapy-related acute leukemia (t-AML), is a severe complication of cytotoxic therapy used for primary cancer treatment. The outcome of these patients is poor, compared to people who develop de novo acute leukemia (p-AML). Cytogenetic abnormalities in t-AML are similar to those found in p-AML but present more frequent unfavorable karyotypes depending on the inducting agent. Losses of chromosome 5 or 7 are observed after alkylating agents while balanced translocations are found after topoisomerase II inhibitors. This study compared t-AML to p-AML using high resolution array CGH in order to find copy number abnormalities (CNA) at a higher resolution than conventional cytogenetics. More CNAs were observed in 30 t-AML than in 36 p-AML: 104 CNAs were observed with 63 losses and 41 gains (mean number 3.46 per case) in t-AML, while in p-AML, 69 CNAs were observed with 32 losses and 37 gains (mean number of 1.9 per case). In primary leukemia with a previously "normal" karyotype, 18% exhibited a previously undetected CNA, whereas in the (few) t-AML with a normal karyotype, the rate was 50%. Several minimal critical regions (MCRs) were found in t-AML and p-AML. No common MCRs were found in the two groups. In t-AML a 40 kb deleted MCR pointed to RUNX1 on 21q22, a gene coding for a transcription factor implicated in frequent rearrangements in leukemia and in familial thrombocytopenia. In de novo AML, a 1 Mb MCR harboring ERG and ETS2 was observed from patients with complex aCGH profiles. High resolution cytogenomics obtained by aCGH and similar techniques already published allowed us to characterize numerous non random chromosome abnormalities. This work supports the hypothesis that they can be classified into several categories: abnormalities common to all AML; those more frequently found in t-AML and those specifically found in p-AML

Genomic aberrations in lung adenocarcinoma in never smokers.

BACKGROUND: Lung cancer in never smokers would rank as the seventh most common cause of cancer death worldwide. METHODS AND FINDINGS: We performed high-resolution array comparative genomic hybridization analysis of lung adenocarcinoma in sixty never smokers and identified fourteen new minimal common regions (MCR) of gain or loss, of which five contained a single gene (MOCS2, NSUN3, KHDRBS2, SNTG1 and ST18). One larger MCR of gain contained NSD1. One focal amplification and nine gains contained FUS. NSD1 and FUS are oncogenes hitherto not known to be associated with lung cancer. FISH showed that the amplicon containing FUS was joined to the next telomeric amplicon at 16p11.2. FUS was over-expressed in 10 tumors with gain of 16p11.2 compared to 30 tumors without that gain. Other cancer genes present in aberrations included ARNT, BCL9, CDK4, CDKN2B, EGFR, ERBB2, MDM2, MDM4, MET, MYC and KRAS. Unsupervised hierarchical clustering with adjustment for false-discovery rate revealed clusters differing by the level and pattern of aberrations and displaying particular tumor characteristics. One cluster was strongly associated with gain of MYC. Another cluster was characterized by extensive losses containing tumor suppressor genes of which RB1 and WRN. Tumors in that cluster frequently harbored a central scar-like fibrosis. A third cluster was associated with gains on 7p and 7q, containing ETV1 and BRAF, and displayed the highest rate of EGFR mutations. SNP array analysis validated copy-number aberrations and revealed that RB1 and WRN were altered by recurrent copy-neutral loss of heterozygosity. CONCLUSIONS: The present study has uncovered new aberrations containing cancer genes. The oncogene FUS is a candidate gene in the 16p region that is frequently gained in never smokers. Multiple genetic pathways defined by gains of MYC, deletions of RB1 and WRN or gains on 7p and 7q are involved in lung adenocarcinoma in never smokers

Pseudodicentric Chromosome Originating from an X-Autosome Translocation in a Male Patient with Cryptozoospermia

International audienceGenetic factors are responsible for 15% of male infertility conditions. Numerical and structural chromosomal anomalies are validated genetic factors leading to spermatogenic quantitative defects, with a frequency depending on the severity of the phenotype. Among the structural chromosomal rearrangements, dicentric chromosomes are generally observed in robertsonian translocations or in cases of Y chromosome isodicentrics. In X-autosome translocations, male carriers are generally infertile, regardless of the position of the breakpoint, due to interrupted spermatogenesis. We report an infertile man bearing an unusual balanced (X;22) translocation, with a centromeric X breakpoint generating a derivative pseudodicentric chromosome psu dic(22;X). Extensive cytogenetic analyses were necessary to determine the precise nature of the derivative chromosome. The likely cause of the reproductive phenotype of the patient is discussed based on meiotic chromosomal conformation

24 colour multifish karyotype showing the complexity of the genomic rearrangements with rearranged chromosomes in most pairs and several unidentified marker chromosomes (bottom left)

<p><b>Copyright information:</b></p><p>Taken from "Biological characterization of two xenografts derived from human CUPs (carcinomas of unknown primary)"</p><p>http://www.biomedcentral.com/1471-2407/7/225</p><p>BMC Cancer 2007;7():225-225.</p><p>Published online 18 Dec 2007</p><p>PMCID:PMC2241840.</p><p></p> Of particular interest are the translocation of chromosome 21 (in green) to the distal chromosome 4 (in grey) and the loss of chromosomes 9. In this cell, there were 2 der(3)t(3, 15) instead of one in most other cells which were analyzed