AIM: To identify chromosomal translocations specific to gastric cancer (GC), spectral karyotyping (SKY) analysis was performed on established cell lines and cancerous ascitic fluids.METHODS: SKY analysis of 10 establi...AIM: To identify chromosomal translocations specific to gastric cancer (GC), spectral karyotyping (SKY) analysis was performed on established cell lines and cancerous ascitic fluids.METHODS: SKY analysis of 10 established cell lines and seven cancerous ascitic fluid samples identified recurrent chromosomal breakpoints and translocations in GC,several of which involved chromosomal loci of oncogenes or tumor suppressor genes.RESULTS: A total of 630 chromosomal breaks were identified. Chromosome no.8 was the most frequently involved in rearrangements (65 breaks), followed by chromosomes no. 11 (53), no. 1 (49), no. 7 (46), no. 13 (37), no. 3 (36), no. 17 (33), and no. 20 (29). Frequent breakpoints were detected in 8q24.1 (30 breaks), 11q13 (29), 13q14 (16), 20q11.2 (14), 7q32 (13), 17q11.2 (13),18q21 (12), 17q23 (9), 18q11.2 (9). SKY analysis identified a total of 242 chromosomal rearrangements including 190 reciprocal and non-reciprocal translocations. The recurrent combinations of chromosomal bands involved in translocations were 8q24.1 and 13q14 (3 cases), 8q24.1 and 11q13 (3), 11q13 and 17q11.2 (2), and 18q11.2 and 20q11.2 (2). Our study validated the ability of SKY to characterize in detail the chromosomal rearrangements in solid tumors and derived cell lines. Moreover,fluorescence in situ hybridization helped to identify the insertions, translocations, and homogeneously staining regions of MYCand CCND1 gene loci.CONCLUSION: The non-random co-localization of certain cytogenetic bands suggests the importance of chromosomal translocations in gastric carcinogenesis, by serving as landmarks for the cloning of GC causing genes.展开更多
Lynch syndrome （LS） is an autosomal dominant inherited cancer predisposition syndrome caused by a mismatch of DNA repair （MMR system）. Lifetime risk of developing endometrial and ovarian cancer in LS is higher tha...Lynch syndrome （LS） is an autosomal dominant inherited cancer predisposition syndrome caused by a mismatch of DNA repair （MMR system）. Lifetime risk of developing endometrial and ovarian cancer in LS is higher than in the general population and gynecologic screening appears interesting. Screening is based on several tests： pelvic ultrasound, endometrial biopsy and hysteroscopy for endometrial cancer, pelvic ultrasound and CA125 for ovarian cancer. Those tests appear efficient for the diagnosis of gynecologic cancers in LS. Nevertheless, screening tests have not proved clinical benefit until now, and potential problems of compliance, risk of false negative cases, and interval cancer associated with screening do justify offering prophylactic surgery to patients. Women with LS should be informed of the potential benefits and risks of screening and the importance of evaluation in case of gynecologic symptoms or abnormal bleeding. Chemoprevention by progestin-containing oral contraceptives and the treatment ofthe potential benefits and risks of screening and the importance of evaluation in case of gynecologic symptoms or abnormal bleeding. Chemoprevention by progestin-containing oral contraceptives and the treatment of premalignant lesion are available options for reducing the risk of endometrial cancer in LS population.展开更多
The eukaryotic genome is packaged into a complex nucleoprotein structure named chromatin, balancing the compactness of genome and the accessibility of regulatory proteins and RNA polymerases to DNA. The mechanisms of ...The eukaryotic genome is packaged into a complex nucleoprotein structure named chromatin, balancing the compactness of genome and the accessibility of regulatory proteins and RNA polymerases to DNA. The mechanisms of the regulation of chromatin dynamics include the post-translational modification of histones, alteration of nucleosome positions by chromatin remodelers, replacement of canonical histones by histone variants with the aid of histone chaperones, and dynamic organization of the three-dimensional genome in the small nucleus. Histone variants are different from canonical histones by substitution of several amino acid residues or changes in amino acid sequence. Histone variants perform specialized functions such as altering nucleosome stability, dynamics, structure, as well as playing critical roles in a range of biological processes like transcriptional regulation, DNA repair and recombination, development and immune responses. Here we discuss how histone variants, their modification and specific loading to chromatin are involved in transcriptional regulation, DNA repair and plant development.展开更多
文摘AIM: To identify chromosomal translocations specific to gastric cancer (GC), spectral karyotyping (SKY) analysis was performed on established cell lines and cancerous ascitic fluids.METHODS: SKY analysis of 10 established cell lines and seven cancerous ascitic fluid samples identified recurrent chromosomal breakpoints and translocations in GC,several of which involved chromosomal loci of oncogenes or tumor suppressor genes.RESULTS: A total of 630 chromosomal breaks were identified. Chromosome no.8 was the most frequently involved in rearrangements (65 breaks), followed by chromosomes no. 11 (53), no. 1 (49), no. 7 (46), no. 13 (37), no. 3 (36), no. 17 (33), and no. 20 (29). Frequent breakpoints were detected in 8q24.1 (30 breaks), 11q13 (29), 13q14 (16), 20q11.2 (14), 7q32 (13), 17q11.2 (13),18q21 (12), 17q23 (9), 18q11.2 (9). SKY analysis identified a total of 242 chromosomal rearrangements including 190 reciprocal and non-reciprocal translocations. The recurrent combinations of chromosomal bands involved in translocations were 8q24.1 and 13q14 (3 cases), 8q24.1 and 11q13 (3), 11q13 and 17q11.2 (2), and 18q11.2 and 20q11.2 (2). Our study validated the ability of SKY to characterize in detail the chromosomal rearrangements in solid tumors and derived cell lines. Moreover,fluorescence in situ hybridization helped to identify the insertions, translocations, and homogeneously staining regions of MYCand CCND1 gene loci.CONCLUSION: The non-random co-localization of certain cytogenetic bands suggests the importance of chromosomal translocations in gastric carcinogenesis, by serving as landmarks for the cloning of GC causing genes.
文摘Lynch syndrome （LS） is an autosomal dominant inherited cancer predisposition syndrome caused by a mismatch of DNA repair （MMR system）. Lifetime risk of developing endometrial and ovarian cancer in LS is higher than in the general population and gynecologic screening appears interesting. Screening is based on several tests： pelvic ultrasound, endometrial biopsy and hysteroscopy for endometrial cancer, pelvic ultrasound and CA125 for ovarian cancer. Those tests appear efficient for the diagnosis of gynecologic cancers in LS. Nevertheless, screening tests have not proved clinical benefit until now, and potential problems of compliance, risk of false negative cases, and interval cancer associated with screening do justify offering prophylactic surgery to patients. Women with LS should be informed of the potential benefits and risks of screening and the importance of evaluation in case of gynecologic symptoms or abnormal bleeding. Chemoprevention by progestin-containing oral contraceptives and the treatment ofthe potential benefits and risks of screening and the importance of evaluation in case of gynecologic symptoms or abnormal bleeding. Chemoprevention by progestin-containing oral contraceptives and the treatment of premalignant lesion are available options for reducing the risk of endometrial cancer in LS population.
基金supported by the National Natural Science Foundation of China(31171168 and 91319304)National Basic Research Program of China(2012CB910503)
文摘The eukaryotic genome is packaged into a complex nucleoprotein structure named chromatin, balancing the compactness of genome and the accessibility of regulatory proteins and RNA polymerases to DNA. The mechanisms of the regulation of chromatin dynamics include the post-translational modification of histones, alteration of nucleosome positions by chromatin remodelers, replacement of canonical histones by histone variants with the aid of histone chaperones, and dynamic organization of the three-dimensional genome in the small nucleus. Histone variants are different from canonical histones by substitution of several amino acid residues or changes in amino acid sequence. Histone variants perform specialized functions such as altering nucleosome stability, dynamics, structure, as well as playing critical roles in a range of biological processes like transcriptional regulation, DNA repair and recombination, development and immune responses. Here we discuss how histone variants, their modification and specific loading to chromatin are involved in transcriptional regulation, DNA repair and plant development.
