Docstoc

Detection of Chromosomal Translocation in Prostate Cancer and

Document Sample
Detection of Chromosomal Translocation in Prostate Cancer and Powered By Docstoc
					       Detection of Chromosomal Translocation in
    Prostate Cancer and Benign Prostatic Hyperplasia
      by Fluorescence in situ Hybridization (FISH)



     Cebulska-Wasilewska A.1,2, Miszczyk J.1,
        Dobrowolska B.3, Dobrowolski Z.3




1Environmental and Radiation Biology Department, The H. Niewodniczański Institute of
Nuclear Physics PAN, Cracow, Poland, 2 Epidemiology and Preventive Medicine
Departmen CM UJ, Poland, 3Urology Department and Clinic CM UJ, Poland
  Prostate cancer epidemiology


           Benign Prostatic Hyperplasia [BPH] and
                     Prostate Cancer [PC]
             are the most common males diseases.


                        Prostate cancer incidence
In Poland prostate       varies widely between:
cancer is the third   ethnic populations, countries
  most common          and increases sharply with
malignant cancer in             older age.
      males.
     Prostate cancer risk is strongly influenced by:




    GENETIC             FAMILIAL              EPIGENETIC
    FACTORS              HISTORY               FACTORS

> genetic          > genes involved in        > lifestyle, smoking
  susceptibility   familial prostate cancer   > ethnic origin
> mutation         (for example: HPC1 on
                   chromosome 1)              > dietary factors
> gene                                        (vitamin D, fats,)
  expression
                                              > androgens
                     Becouse...



> genetic alteration on multiple chromosomes including
especially chromosome 1,

> many susceptibility loci have been reported at this
chromosome,

> many types of cancers are associated with specific
types of chromosomal aberrations
                Aim of study




Compare the vulnerability to the induction in
chromosome 1 translocation in lymphocytes
from prostate cancer with that from benign
prostatic hyperplasia.
                        Materials and methods

Investigated groups                    Fig. 1. Standard cytogenetic procedure
                                                            antibiotics, PHA                  colcemid
[BPH] – 27 persons from the                         X-rays                   Incubation at
                                                  irradiation              37ºCfor 72 hours
control group with benign
prostatic hyperplasia.
(average age 68.9 ± 8.3)               Donor’s peripheral 80% RPMI 1640,
                                       blood samples      20% fetal calf serum
[PCP] – 30 prostate cancer patients.
(average age 62.4±5.3)                      KC
                                            L


Challenging dose                                   Fixation methanol/acetic acid
                                                             (3:1)
In the laboratory tubes with blood
were irradited with X-rays doses of 2 Gy.
Culture were set up according to standard cytogetic procedure, then were
harvested and followed by fixation procedure.
Fluorescent in situ hybridisation (FISH)
Biotin-labeled whole chromosome probes specific to chromosome 1 (Star Fish
Cambio, UK).
                                Materials and methods

   Fig. 2. General FISH protocol
                                                                                 Fig. 3.
             Labeled
              probe                  Hybridization 37ºC,
                                          72 hours
                                                           detection


                       Place probe                                                         Fig. 4.
                         on slide


                                                                       Fig. 5.
The slides were examined at 1000x magnification
of the epifluoescence microscope (Nicon Eclipse E400).

Donors were examined for presence in their in peripheral blood lymphocytes of
chromosome translocations according to the criteria of Protocol for Aberration
Identification and Nomenclature-PAINT [1].
[1] Tucker J.D. et al. A proposed system for scoring structural aberrations detected by chromosome painting.
Cytog. Cell Genet. (1995), 211-221.
                                Materials and methods

                          2 types of parameters were
                         used to describe the extent of
                             chromosomal damage

 t – frequency of chromosome 1                                FG/100 – genomic frequency of
           translocation                                       chromosome 1 translocation
                                                                         FG=Fg/2.05fp(1-fp) [2].
FG - the total genomic translation frequency
Fg – the translocation frequency measured by FISH after painting
Fp – the fraction of th genome represented the painted chromosome,
for chromosome 1 = 0.084 fraction of the genome 8.4%)
[2] Lucas J.N., Sachs R.K. Using three-color chromosomepainting to test chromome aberration models. Proc. Natl.
Sci90, 1484-14
                                                  Results

Sig. 1. X-rays effect on frequency of chromosome 1 translocation determined
by FISH in peripheral lymphocytes in patients with prostate cancer [PCP]
and benign prostate hyperplasia [BPH].
                                                            14,6
                        16
                        14
                        12
                                          10,24
                   t




                        10
                          8
                          6
                          4
                          2
                          0
                                      BPH               PC
T – number of translocations/1000 cells

Number of translocations/1000 cells (t) was significantly higher
in patients with prostate cancer (14.60±0.91) than in the control
group (10.24 ±1.10; p<0.01).
                                                 Results

Sig. 2. Genomic frequency of chromosome 1 translocation for patients with
prostate cancer [PCP] and benign prostatic hyperplasia [BPH].

                                  0,6                      0,55

                                  0,5          0,38
                                  0,4
                         FG/100




                                  0,3

                                  0,2

                                  0,1

                                   0
                                               BPH         PC

 FG/100 - genomic frequency of translocation

Percentage of FG/100 was significantly higher in patients with
prostate cancer (0.55±0.03) that obtained for the reference group
(0.38 ±0.04, p<0.01).
We want to study correlation between
occur cancer in family and frequency of
chromosome 1 translocation.
                                                Results

  Tab. 1. Correlations for patients with prostate cancer between age of donors,
  existing cancer in the closely related members of family and t.

CiF – reported cancer in the immediate family                             t

t – number of translocations/1000 cells               Age      R        0.50
                                                               p<       .001
R – correlation coefficient
                                                      CiF      R        0.11
                                                               p<       .001


 High and significant correlation between age of donors and
 frequency of chromosome 1 translocation was observed (0.50;
 p<0.001).
 Furthermore, there was also correlation between frequency of
 chromosome 1 translocation observed in patients who had reported
 other cancers in family.
                       Conclusions

1. These studies, although preliminary, are suggesting
that frequency of translocation detected in the response
to challenging treatment might be used as predictor of
susceptibility for prostate cancer patients.
2. Our results might confirm hypothesis that exist an
association between predisposition to genetic instability
chromosome 1 and hereditary or familial conditioning
of prostate cancer.
However, more studies are necessary of other factors which
could affect genomic frequency of translocations such as: life
style, diet or genetic polymorphism.

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:23
posted:12/1/2012
language:English
pages:13