Cancer Cytogenetic Laboratory
In our laboratory, chromosomal aberrations associated with malignant tumors are detected by conventional and molecular cytogenetic techniques. The majority of incoming bone marrow, peripherial blood, lymph node, liquor, ascites and other tissue samples is investigated for oncohematological diseases. The karyotyping following G-banding is capable of characterizing the whole chromosome set of dividing cells with the identification of numerical abnormalities and structural aberrations affecting at least 5-10 Mb long genomic range. Cryptic aberrations undetectable by conventional cytogenetics are screened by target specific fluorescence in situ hybridization which technique can be applied for any cytological and histological samples because it does not need any cell culture. At present, FISH is used for detection of therapy relevant aberrations in clinically justified cases. FISH labeling is also performed on metaphase preparations if the evaluation of the karyotype is difficult because of its complexity. Our cytogenetic core facility covers not only the Medical Center of University of Pécs, but also larger regions with main activity in the South-West part of the country.
FISH probes available in our laboratory are listed here.
Interphase-FISH is a robust method of the oncopathological diagnostics. The preparations are evaluated manually in most laboratories, however, some non-negligible problems arise from this way of investigation: (i) when the ratio of positivity is very low a huge number of nuclei needs to be evaluated to insure statistical reliability, however, this is time-consuming; (ii) bias of the investigator might cause over- or underestimation of positive events, especially at high or low concentrations of positivity, respectively; (iii) the concentration level of the investigator may have an influence on results of the analysis; (iv) spectrum of interobserver and interlaboratory variability; (v) an objective definition of translocation-related fusion/colocalization of signals is lacking, in spite of the crucial importance of this parameter. These difficulties can be eliminated by using motorized microscopy and digital image analysis.
We have introduced the following automated, 3D signal pattern evaluating techniques in the last few years: (i) genotyping on cytological preparations (detection of BCR/ABL juxtaposition in chronic myeloid leukemia); (ii) combined fluorescent immunophenotyping and genotyping on cytological samples for the follow-up of minimal residual disease (identification of leukemic cells by consecutive CD10 immunolabeling followed by FISH analysis of ETV6/RUNX1 fusion in pediatric acute lymphoblastic leukemia); (iii) combined chromogen immunophenotyping and molecular cytogenetic analysis using four different genetic markers on cytological samples (CK-7 immunolabeling followed by UroVysion analysis in bladder cancer); (iv) genotyping on histological samples (investigation of IGH/CCND1 and IGH/BCL-2 translocations in mantle cell lymphoma and follicular lymphoma, respectively). We think these standardized techniques contribute to the development of pathological diagnostics, therefore we would like to enlarge our automated interphase cytogenetic potencial and capacity in the future.
Kajtár B, Méhes G, Lörch T, Deák L, Kneifné M, Alpár D, and Pajor L: Automated Fluorescent In Situ Hybridization (FISH) Analysis of t(9;22)(q34;q11) in Interphase Nuclei. Cytometry Part A, 2006 Jun;69(6):506-14.
Alpár D, Kajtár B, Kneif M, Jáksó P, László R, Kereskai L, Pajor L: Automated detection of residual leukemic cells by consecutive immunolabeling for CD10 and FISH for ETV6/RUNX1 rearrangement in childhood acute lymphoblastic leukemia. Cancer Genetics and Cytogenetics, 2007 Feb;173(1):23-30.
Pajor G, Süle N, Alpár D, Kajtár B, Kneif M, Bollmann D, Somogyi L, Pajor L: Increased efficiency of detecting genetically aberrant cells by UroVysion test on voided urine specimens using automated immunophenotypical pre-selection of uroepithelial cells. Cytometry Part A, 2008 Mar;73A(3):259-65.
Alpár D, Hermesz J, László R, Kereskai L, Jáksó P, Pajor G, Pajor L, Kajtár B: Automated FISH analysis using dual-fusion and break-apart probes on paraffin-embedded tissue sections. Cytometry Part A, 2008 Jul;73(A):651-57.
László R, Alpár D, Kajtár B, Lacza Á, Ottóffy G, Kiss Cs, Bartyik K, Nagy K, Pajor L. Detection of early precursors of t(12;21) positive pediatric acute lymphoblastic leukemia during follow-up. Pediatric Blood and Cancer, 2010 Jan;54(1):158-60.
Alpár D, Nagy G, Hohoff C, Kajtár B, Bartyik K, Hermesz J, Jáksó P, Andrikovics H, Kereskai L, Pajor L. Sex chromosome changes after sex-mismatched allogeneic bone marrow transplantation can mislead the chimerism analysis. Pediatric Blood and Cancer, 2010 Dec;55:1239-42.
Alpár D, Kereskai L. Three-step cytogenetic evolution in paediatric acute lymphoblastic leukaemia with t(12;21). BloodMed, 2010 Dec; 251.
Alpár D. Recurrent disease or donor cell leukemia? Brain teaser after allogeneic bone marrow transplantation. Chimerism, 2011 Jan;2(1):19-20.
Nagy Z, Kajtár B, Jáksó P, Dávid M, Kosztolányi S, Hermesz J, Kereskai L, Pajor L, Alpár D. Evolutionary sequence of cytogenetic aberrations during the oncogenesis of plasma cell disorders. Direct evidence at single cell level. Leukemia Research, 2011 Aug;35(8):1114-6.
Pajor G, Somogyi L, Melegh B, Alpár D, Kajtár B, Farkas L, Kneif M, Bollmann D, Pajor L, Süle N. Urovysion: considerations on modifying current evaluation scheme, including immunophenotypic targeting and locally set statistically derived diagnostic criteria. Cytometry Part A, 2011 May;79(5):375-82.
Pajor G, Alpár D, Kajtár B, Melegh B, Somogyi L, Kneif M, Bollmann D, Süle N, Pajor L. Automated signal pattern evaluation of a bladder cancer specific multiprobe-FISH assay applying a user-trainable workstation. Microscopy Research and Technique, 2012 Jun;75(6):814-20.
Haltrich I, Csóka M, Kovács G, Török D, Alpár D, Ottoffy G, Fekete G. Six cases of rare gene amplifications and multiple copy of fusion gene in childhood acute lymphoblastic leukemia. Pathology & Oncology Research (accepted)
Alpár D, de Jong D, Savola S, Yigittop H, Kajtár B, Kereskai L, Pajor L, Szuhai K. MLPA is a powerful tool for detecting lymphoblastic transformation in chronic myeloid leukemia and revealing the clonal origin of relapse in pediatric acute lymphoblastic leukemia. Cancer Genetics (accepted)
Pajor G, Kajtár B, Pajor L, Alpár D. State-of-the-art FISHing: automated analysis of cytogenetic aberrations in interphase nuclei. Review. Cytometry Part A (accepted)
Our laboratory is involved in the teaching of two PhD courses entitled ’In situ hybridization–interphase cytogenetics and its application in the pathological practice’ and ’Cytogenetic aberrations in hematopoietic tumors’.
Donát Alpár, PhD, ISAC Scholar
Judit Hermesz, BSc
medical diagnostic analyst
Gábor Pajor, PhD
Ivett Sepsei, BSc
medical diagnostic analyst