			Home About us Contact

Cytogenetic Profile (cytogenetic + profile)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Cytogenetic profile of locally invasive posterior uveal melanoma

ACTA OPHTHALMOLOGICA, Issue 2009
R PARROZZANI
Purpose To analyze cytogenetic profile of locally invasive posterior uveal melanoma (UM). Methods Twenty consecutive cases of large posterior UM with histopathologically confirmed extrascleral extension were included in this non-comparative cases series. Fine needle aspiration biopsy (FNAB) of the intraocular tumor portion was performed using 25-gauge trans-scleral approach, immediately after enucleation of the globe. FNAB of the extrascleral tumor portion was also performed when it was > 1mm in thickness. Sampled material underwent fluorescence in situ hybridization (FISH). Follow-up was longer than 12 months. Results Six tumors (30%) had both intraocular and extraocular tumor samplings, whereas 14 tumors (70%) showed extrascleral extension less than 1 mm in thickness. Monosomy 3 was found in 5 tumors (25%), whereas disomy 3 in 15 tumors (75%). Cytogenetic profile of the intraocular tumor portion appears to be maintained in the extrascleral extension in all cases (100%). Five patients (25%) developed metastatic disease during follow-up (all had monosomy 3 tumors). Conclusion Extrascleral extension appears more frequent in disomy 3 tumors. Cytogenetic profile of locally invasive posterior UM is maintained in the extrascleral tumor portion and must be considered the most important prognostic factor in locally invasive tumors. [source]

Conventional cytogenetics in myelofibrosis: literature review and discussion

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2009
Kebede Hussein
Abstract The clinical phenotype of myelofibrosis (MF) is recognized either de novo (primary) or in the setting of polycythemia vera (post-PV) or essential thrombocythemia (post-ET). Approximately one-third of patients with primary MF (PMF) present with cytogenetic abnormalities; the most frequent are del(20q), del(13q), trisomy 8 and 9, and abnormalities of chromosome 1 including duplication 1q. Other less frequent lesions include ,7/del(7q), del(5q), del(12p), +21 and der(6)t(1;6)(q21;p21.3). In general, cytogenetic abnormalities are qualitatively similar among PMF, post-ET MF and post-PV MF although their individual frequencies may differ. Based on prognostic effect, cytogenetic findings in MF are classified as either ,favorable' or ,unfavorable'. The former include normal karyotype or isolated del(20q) or del(13q) and the latter all other abnormalities. Unfavorable cytogenetic profile in both PMF and post-PV/ET MF confers an independent adverse effect on survival; it is also associated with higher JAK2V617F mutational frequency. In addition to their prognostic value, cytogenetic studies in MF ensure diagnostic exclusion of other myeloid neoplasms that are sometimes associated with bone marrow fibrosis (e.g. BCR-ABL1 -positive or PDGFRB -rearranged) and also assist in specific treatment selection (e.g. lenalidomide therapy is active in MF associated with del(5q). [source]

Hormone escape is associated with genomic instability in a human prostate cancer model

INTERNATIONAL JOURNAL OF CANCER, Issue 5 2009
Marie-Emmanuelle Legrier
Abstract Lack of hormone dependency in prostate cancers is an irreversible event that occurs through generation of genomic instability induced by androgen deprivation. Indeed, the cytogenetic profile of hormone-dependent (HD) prostate cancer remains stable as long as it received a hormone supply, whereas the profile of hormone-independent (HID) variants acquired new and various alterations. This is demonstrated here using a HD xenografted model of a human prostate cancer, PAC120, transplanted for 11 years into male nude mice and 4 HID variants obtained by surgical castration. Cytogenetic analysis, done by karyotype, FISH, CGH and array-CGH, shows that PAC120 at early passage presents numerous chromosomal alterations. Very few additional alterations were found between the 5th and 47th passages, indicating the stability of the parental tumor. HID variants largely maintained the core of chromosomal alterations of PAC120 , losses at 6q, 7p, 12q, 15q and 17q sites. However, each HID variant displayed a number of new alterations, almost all being specific to each variant and very few shared by all. None of the HID had androgen receptor mutations. Our study indicates that hormone castration is responsible for genomic instability generating new cytogenetic abnormalities susceptible to alter the properties of cancer cell associated with tumor progression, such as increased cell survival and ability to metastasize. © 2008 Wiley-Liss, Inc. [source]

Astroblastoma: Clinicopathologic Features and Chromosomal Abnormalities Defined by Comparative Genomic Hybridization

BRAIN PATHOLOGY, Issue 3 2000
Daniel J. Brat M.D., Ph.D.
Astroblastomas are uncommon brain tumors whose classification and histogenesis have been debated. Precise criteria for diagnosis have been described only recently, but have not found wide acceptance. We report the clinical, radiographic, and histopathologic features of 20 astroblastomas, and the chromosomal alterations in seven cases as detected by comparative genomic hybridization (CGH). The tumors occurred both in children and young adults (average age, 14 years), most often as well circumscribed, peripheral, cerebral hemispheric masses. Radiographically, the lesions were contrastenhancing and solid, often with a cystic component. All were characterized histologically by astroblastic pseudorosettes, and most displayed prominent perivascular hyalinization, regional hyaline changes, and pushing borders in regard to adjacent brain. Tumor cells were strongly immunoreactive for S-100 protein, GFAP, and vimentin. Staining for EMA was focal. Ten of 20 astroblastomas were classified as "well differentiated" and 10 were classified as "malignant," largely on the basis of hypercellular zones with increased mitotic indices, vascular proliferation, and necrosis with pseudopalisading. All 10 well differentiated lesions and 8 of 10 malignant lesions were completely resected. None of the well differentiated astroblastomas recurred within the limited follow-up period. Three malignant astroblastomas recurred, including two incompletely resected tumors, and one that had been totally resected. One patient died of disease following recurrence. The most frequent chromosomal alterations detected by CGH were gains of chromosome arm 20q (4/7 tumors) and chromosome 19 (3/7). The combination of these gains occurred in three, including two well differentiated and one malignant astroblastoma. Other alterations noted in two tumors each were losses on 9q, 10, and X. These chromosomal alterations are not typical of ependymoma or infiltrating astrocytic neoplasms, and suggest that astroblastomas may have a characteristic cytogenetic profile in addition to their distinctive clinical, radiographic, and histopathologic features. [source]

MYC gene numerical aberrations in actinic keratosis and cutaneous squamous cell carcinoma

BRITISH JOURNAL OF DERMATOLOGY, Issue 5 2009
A. Toll
Summary Background, The genetic alterations that drive the transition from actinic keratoses (AKs) to cutaneous squamous cell carcinomas (SCCs) have not been defined precisely. Amplification and/or overexpression of the MYC proto-oncogene have been demonstrated in several human, malignant tumours including head and neck SCCs. Objectives, To evaluate the presence of MYC genomic aberrations in both AKs and SCCs. Methods, Skin biopsy specimens corresponding to AKs, SCCs and control samples were included in two paraffin-embedded tissue microarrays. MYC cytogenetic profile was evaluated by fluorescence in situ hybridization (FISH). The results obtained were compared with MYC immunohistochemical expression. Results, Twenty-three AKs and 30 SCCs were evaluated. MYC numerical aberrations were observed in eight of 23 (35%) AKs and 19 of 30 (63%) SCCs (P = 0·05). MYC numerical aberrations were more frequent in moderately to poorly differentiated SCCs (77%) when compared with well-differentiated SCCs (25%; P = 0·027). A significant association between copy number gains of MYC by FISH analysis and MYC protein expression was demonstrated. Conclusions,MYC gains and amplifications are frequent cytogenetic abnormalities in SCCs and may play a relevant role in promoting SCC undifferentiation and tumoral progression. [source]

Cytogenetic profile of locally invasive posterior uveal melanoma

Molecular cytogenetic characterization of non-Hodgkin lymphoma cell lines

GENES, CHROMOSOMES AND CANCER, Issue 3 2002
Sukvarsha Mehra
Spectral karyotyping (SKY) and comparative genomic hybridization (CGH) have greatly enhanced the resolution of cytogenetic analysis, enabling the identification of novel regions of rearrangement and amplification in tumor cells. Here we report the analysis of 10 malignant non-Hodgkin lymphoma (NHL) cell lines derived at the Ontario Cancer Institute (OCI), Toronto, designated as OCI-Ly1, OCI-Ly2, OCI-Ly3, OCI-LY4, OCI-Ly7, OCI-Ly8, OCI-Ly12, OCI-Ly13.2, OCI-Ly17, and OCI-Ly18, by G-banding, SKY, and CGH, and we present their comprehensive cytogenetic profiles. In contrast to the 52 breakpoints identified by G-banding, SKY identified 87 breakpoints, which clustered at 1q21, 7p15, 8p11, 13q21, 13q32, 14q32, 17q11, and 18q21. G-banding identified 10 translocations, including the previously described recurring translocations, t(8;14)(q24;q32) and t(14;18)(q32;q21). In contrast, SKY identified 60 translocations, including five that were recurring, t(8;14)(q24;q32), t(14;18)(q32;q21), t(4;7)(p12;q22), t(11;18)(q22;q21), and t(3;18)(q21;p11). SKY also identified the source of all the marker chromosomes. In addition, 10 chromosomes that were classified as normal by G-banding were found by SKY to be rearranged. CGH identified seven sites of high-level DNA amplification, 1q31-32, 2p12-16, 8q24, 11q23-25, 13q21-22, 13q32-34, and 18q21-23; of these, 1q31-32, 11q23-25, 13q21-22, and 13q32-34 have previously not been described as amplified in NHL. This comprehensive cytogenetic characterization of 10 NHL cell lines identified novel sites of rearrangement and amplification; it also enhances their value in experimental studies aimed at gene discovery and gene function. © 2002 Wiley-Liss, Inc. [source]

Cytogenetic analysis of pediatric anaplastic large cell lymphoma,

PEDIATRIC BLOOD & CANCER, Issue 3 2010
Lara Mussolin PhD
Abstract Background Anaplastic large cell lymphoma (ALCL) constitutes approximately 15% of pediatric and 3% of adult non-Hodgkin lymphomas. Most pediatric cases harbor the reciprocal translocation t(2;5)(p23;q35), involving the alk gene. Cytogenetic studies of ALCL have mostly been published as case-reports. The aim of this study was to determine the cytogenetic profiles of a series of pediatric ALCL and to compare them with pediatric and adult ALCL from the literature. Methods Eighteen children treated at our Institution were studied by standard cytogenetic analysis and RT-PCR for the specific t(2;5) translocation product. Comparative analysis was performed on our findings and on the karyotypes of 48 pediatric and 39 adult ALCL reported in the literature. Results Karyotype was obtained in 16/18 ALCL: 9 showed translocation t(2;5) and 1 an alk variant form. Structural and numeric chromosomal abnormalities were identified in both pediatric and adult series. Trisomies were found preferentially in pediatric patients (P,=,0.013) and monosomies in adults (P,=,0.038). Trisomy 7 was found in 22% (13/59) of pediatric cases with abnormal karyotype and only in 5% (2/38) of adults; monosomy of chromosome 13 in 13% (5/38) of adults and only in 2% (1/59) of pediatric patients and monosomy of chromosome 15 in 16% (6/38) of adults and in none of the pediatric ALCL. Conclusion Our data suggest that pediatric and adult ALCL are characterized by different numerical chromosomal abnormalities. Larger prospective studies may elucidate their potential prognostic impact. Pediatr Blood Cancer. 2010;55:446,451. © 2010 Wiley-Liss, Inc. [source]

Deep-seated, well differentiated lipomatous tumors of the chest wall and extremities

CANCER, Issue 2 2005
The role of cytogenetics in classification, prognostication
Abstract BACKGROUND Intramuscular lipomas and atypical lipomatous tumors (ALT) are common deep-seated lipomatous tumors of the chest wall and extremities. Distinguishing between these two entities can be difficult based on histologic analysis alone. However, the cytogenetic profiles of ALT and intramuscular lipomas are distinct. Correct classification is important, because aggressive local disease recurrence occurs more frequently in patients with ALT than in patients with intramuscular lipoma. The authors examined their single institutional experience and correlated their classification with clinical features and outcome. METHODS In the current study, 106 patients with deep-seated, well differentiated adipose tumors of the chest wall and extremities were classified as having ALT or intramuscular lipoma using a combined approach of histology and cytogenetics, if available. The classification was correlated with clinicopathologic features and follow-up data. RESULTS Fifty-five patients were classified as having intramuscular lipoma and 51 were classified as having ALT. Classification did not correlate with age and gender (P = 0.28 and P = 0.96, respectively). Intramuscular lipomas were smaller than ALTs (P < 0.0001), but there was significant overlap between the 2 groups. ALT occurred preferentially in the lower extremity (P < 0.0009). Four percent of patients with intramuscular lipomas and 27% of patients with ALTs developed local disease recurrence (P = 0.0006). Disease recurrence did not correlate with patient age at diagnosis, patient gender, tumor size, and tumor location (P = 0.45, P = 0.26, P = 0.49, and P = 0.28, respectively). Within the subset of patients with ALTs, disease recurrence did not correlate with patient age at diagnosis, patient gender, or tumor location (P = 0.38, P = 0.54, and P = 0.86, respectively). CONCLUSIONS Classification of deep-seated, well differentiated lipomatous tumors of the extremities and chest wall using a combined approach of histology and cytogenetics correlated well with biologic behavior/disease recurrence. This combined approach is advocated to better stratify patients for treatment purposes and follow-up. Cancer 2005. © 2004 American Cancer Society. [source]