Cancer ........an old........ new problem
1. The earliest records of
cancer, from 2500 BC
2. The oldest known cases
(osteosarcomas) have been
verified in Egyptian
mummies that died 4000
The first real scientific observation
on cancer etiology was made in
1775 when Percival Pott, an English
physician, described a high
incidence of cancer of the scrotum
in men working as chimney sweeps.
N
z
The somatic mutation theory of cancer
Theodor Boveri (1862-1915)
Acquired genetic changes are
the main causes of malignant
transformation of target cells
The Somatic Mutation Theory
 The vast majority of tumors are monoclonal.
 Many types of neoplasia occur not only as
sporadic lesions, but also in families with inherited
predisposition.
 The majority of carcinogenic agents are also
mutagenic.
 Tumor cells are characterized by acquired genetic
changes, many of which can be identified at
chromosome level.
 
(?),XY
(?),XX
Painter (1921)

46,XY

46,XX
(Tjio & Levan, 1956)
Turner’s syndrome
(Ford et al., 1959)
(Ford et al., 1959)
Klinefelter ’s syndrome
(Jacobs et al., 1959)
Down’s syndrome
(Lejeune et al., 1959)
Nowell & Hungerford, 1960
G-bands
R-bands
C-bands
Q-bands
Caspersson et al., 1970
3x109
Rowley, 1973
Overview of the Cancer Cytogenetic Database
No. of cases
35000
30000
25000
20000
15000
10000
5000
0
1983
1985
1988
1991
1994
1998
International System for Human Cytogenetic Nomenclature
Rearrangement
Addition
Deletion
Derivative
Double minute
Duplication
Insertion
Abbreviation
add
Description
Addition of unknown material to a chromosome
Interstitial or terminal loss of chromosomal material
del
der
dmin
dup
ins
Structurally rearranged chromosome resulting from more than one
change within a single, two, or even more chromosomes
Multiple copies of acentric chromosomal material
Duplication of chromosomal segment
A chromosomal segment has moved into an interstitial position
within the same or another chromosome
Inversion
inv
Isochromosome
i
Marker
mar
Monosomy
-
Loss of one chromosome copy
Translocation
t
Transfer of material between two or more chromosomes
Ring
r
Break and fusion of the two chromosome arms
Trisomy
+
Gain of one chromosome copy
A chromosomal segment has rotated 180 degrees
Mirror image chromosome with two identical arms
Rearranged chromosome in which no part can be identified
The genetic profiles of tumors can be assessed
at different level of resolution
Classical cytology – Morphology
DNA flow cytometry- Assessing the amount of DNA
Cytogenetics- Studying chromosomal changes
Molecular cytogenetics- FISH, M-FISH, and CGH
Molecular genetics – Studying changes of the structure and
function of genes
Cytogeneticanalysis
Analysis
Cytogenetic
"
Collagenase II
-
Sampling
Mechanical and enzymatic disaggregation
T2-1
T2-2
T3-2
3-10 Days
Hypotonic treatment Fixation
Short-term culture
Harvest and preparation of the slides
T1-2
T1-1
47,X,-Y,del(2)(q21q31),t(3;5)(q27q31),
del(5)(q11q13),+7,-9,+r[50]
G-Banding
Analysis
Karyotyping (ISCN)
New York
Length of the haploid human DNA
4 million base would be equivalent to 8 km
London
Londo
n
3x109
Examples of different types of FISH probes
Gene-specific probe
Centromeric probe
Chromosome-painting probe
Telomeric probe
SKY analysis
11
2
3
22 X
Y
probe cocktail
Cot-1 DNA
Denaturation
Labeling of the individual chromosome painting probes
Hybridization
Hybridization at 37oC 24-72 h
Metaphase chromosome preparation
Washing
Analysis
DAPI
Classification colors
Display color
CGH analysis
20-30
-30 paraffin
sections
20
Paraffin
sections
Isolation and labelling FITC-dUTP
Tumor DNA
Cot-1 DNA
Hybridization to normal metaphase
Control DNA
Isolation and labellingNormal DNA
Gain (green-to-red ratios >1.2)
Loss (green-to-red ratios < 0.80)
History of human cytogenetics
Hsu (1981)
1.The dark ages before 1952
2.The hypotonic (1952 to 1958).
3.Trisomy period (1959 to 1969).
4.Banding era began in 1970.
5.Color chromosomes.
☻CGH (Kallioniemi et al., 1992).
☻M-FISH (Speicher et al., 1996).
Examples of Genetic Changes Associated With Hematologic Disorders
Tumor types
Chromosome aberrations
Genes involved
CML
t(9;22)(q34;q11)
ABL, BCR
AML M2
t(8;21)(q22;q22)
ETO, AML1
AML M3
t(15;17)(q22;q12)
PML, RARA
AML M4
inv(16)(p13q22)
MYH11, CBFB
AML M5
t(9;11)(p21-22;q23)
AF9, MLL
t(8;14)(q24;q32)
MYC, IGH
t(8;22)(q24;q11)
MYC, IGl
t(2;8)(p12;q24)
IGk, MYC
t(14;18)(q32;q21)
IGH, BCL2
Myeloid leukemia
Lymphoma
Burkitt´s
Non-Hodgkin´s