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Marker chromosome 1q+ in acute lymphocytic leukemia
Marker Chromosome l q ÷ in Acute Lymphocytic Leukemia Iskra Petkovit , Melita Nakit , Aleksandar Tiefenbach, Josip Konja, Maja Ka telan, Ljubica Rajit , and Ranka Feminit -Kes
ABSTRACT: This paper presents the results of a cytogenetic analysis on a patient with acute lymphocytic leukemia (ALL) type L2 according to the FAB classification. Of the metaphases examined, 69.3% belong to the aberrant clone of pseudodiploid karyotype. Marker chromosome 14q+ has been identified in all the cells of the clone. Duplication was found in 30% of the metaphases, and in 15% triplication of the proximal segment of the long arm of chromosome #1 (ql 1-q21). In one metaphase the long arm of chromosome #1 is made up of segment q11q21 four times repeated. Aberrations of chromosome #1 support the idea that heterochromatic region may be related to the higher degree of the cell malignity.
INTRODUCTION Aberrations of chromosome #1 frequently accompany malignant transformation. They have been found in both malignant hemopathies and in solid tumors in humans [1-8]. This wide range of human neoplasms with chromosome #1 aberrations suggests that they are not a primary disorder in the process of malignant transformation, but are probably of secondary in nature and appear in the course of clonal evolution [6, 9-11]. This report presents a case of lymphocytic leukemia with tandem duplication and triplication of the proximal segment of the long arm of chromosome #1, which appeared in the course of clonal evolution. MATERIALS A N D METHODS
Cytogenetic analysis of malignant cells was carried out immediately after the diagnosis had been made and before initiating therapy. Preparations obtained after 24hour peripheral blood cell culture without mitogen stimulation were used. Chromosome identification was made by applying GTG and BCG bending methods. Besides the cytogenetic analysis of the malignant cell population, determination of the patient's constitutional karyotype was also carried out on a routine lymphocyte culture method stimulated with PHA.
From the Institute for Mother and Child Health (I. P., M. N.), the Division of Hematology and Oncology ~alata, Department of Pediatrics, Faculty of Medicine (A. T., J. K., L. R., R. F-K.), and the Department of Oncology and Radiotherapy, Medical Faculty (M. K.), University of Zagreb, Zagreb, Yugoslavia.
Address requests for reprints to Dr. Iskra Petkovi~, Svearova 5, 41000 Zagreb, Yugoslavia. Received December 2, 1985; accepted February 18, 1986.
251 © 1987 Elsevier Science Publishing Co., Inc. 52 Vanderbilt Ave., New York, NY 10017
Cancer Genet Cytogenet 24:251-255(1987) 0165-4608/87/$03.50
252
I. Petkovid et al.
CASE HISTORY
The patient was a 14.5-year-old boy admitted to the hospital for poor general health, exhaustion, edema of the eyelids, weight loss, pain in the knees and below the rib arches, and enlarged liver, spleen, and lymph nodes. On admission the number of leukocytes in the peripheral blood was 6.2 x 109/L with 0.12 lymphoblasts. In the bone marrow 90% of the cells were found to fulfill the criteria of L2 lymphoblasts, according to the FAB classification. Other lines of hematopoiesis were almost completely repressed and there was no thrombocytopoiesis. Cytochemical investigations showed that the cells were periodic acid-Schiff, peroxidase, and esterase negative, but acid phosphatase was positive. High-risk group anti-leukemia therapy was given. After 3.5 months the boy was in good condition in complete hematologic
G-banded karyotype of a leukemic cell: 46,XY,trip (1)(qllq21),14q +.
Figure 1
1
2
3
4
5
i{ i} i( 1| ii C! Ii 6
7
8
II !i It 13
14
ii ell 19
20
15
9
10
11
12
¢i il N 16
~ 21
17
18
ie, ~e 22
X y
253
Marker l q + in ANLL
Figure 2
Partial karyotypes of G-banded leukemic cells showing duplication (A), triplication (B), and quadruplication (C) of bands q l l to q21 on chromosome #1. A normal chromosome #1 is on the left side in each pair. remission and was discharged from hospital. He was readmitted shortly thereafter, however, in a deteriorated condition with a profound pancytopenia. The clinical condition of the patient did not improve with a fast lethal outcome of the disease.
RESULTS AND DISCUSSION Cytogenetic investigation on a lymphocyte culture stimulated by PHA revealed a normal constitutional karyotype. The modal n u m b e r of malignant cell chromosomes was 46. A total of 41 metaphases was analyzed. Twelve cells (30.7%) had a normal karyotype, whereas, 69.3% of the metaphases belonged to an aberrant clone with a pseudodiploid karyotype. GTG b a n d i n g methods revealed a structural disorder of chromosomes #1 and #14. A marker chromosome, 1 4 q + , was present in all cells of the clone, whereas, in eight metaphases (20.5%) this was the only chromosome disorder. It was not possible to determine the origin of the excess material on chromosome # 1 4 (Fig. 1). Aside from chromosome 1 4 q + , a structural anomaly of chromosome #1 was also found in 19 cells. By precise analysis of the band pattern of the long arm of the aberrant chromosome, duplication was identified in some cells and in others triplication of the 1q11-q21 segment (Fig. 2). The proximal segment of the long arm of chromosome #1 (i.e., a segment of the constitutive heterochromatin] was affected by duplication of triplication, which was confirmed with a BCG b a n d i n g method (Fig. 3). Duplication was found in 12 (30.7%) and triplication in six metaphases (15.3%) examined. In one metaphase an aberrant chromosome #1 with an interesting G-banding pattern was identified, It seems that the long marker arm was made up of the 1q11-q21 segment repeated four times,
254
I. Petkovi~ et al.
V
Figure 3 Partial karyotype of three C-banded malignant cells (duplication A, triplication A). whereas, the distal part of the long arm (1q21-qter) was lost. Two metaphases had a tetraploid n u m b e r of chromosomes but, due to the poor quality of the metaphases, they could not be karyotyped. Only two descriptions of tandem triplications of the long arm of chromosome #1 have been found in the literature. P a p e n h a u s e n et al. and K n u u t i l a et al. have identified tandem triplication q21-q32 in the case of myelodysplastic syndrome and essential thrombocythemia, respectively [12, 13]. In our case of A L L - - i n addition to the marker 14q + - - d u p l i c a t i o n , triplication, and quadruplication of a segment of the long arm of chromosome #1, ranging from band q l l to q21, has been established. Marker chromosome distribution in the malignant cell population indicated instability and a gradual a c c u m u l a t i o n and higher complexity of structural chromosome aberrations. Chromosome dup(1) is unstable and prone to further changes, which is indicated by the existence of a marker with segment triplication or a marker where the segment is repeated four times. The m e c h a n i s m responsible for multiplication may be that suggested by Pall [14]. It is of interest that the region of chromosome #1 involved in the multiplication comprised the segment of constitutive heterochromatin. Doneda et al. suggested that elimination or relocation of heterochromatic regions may favor tumor progression [15]. Thus, the finding suports the idea that heterochromatic region may favor a higher degree of malignancy. Supported by Grant 59 from Samoupravna interesna zajednica za znanstveni rad u oblasti zdravstva SR Hrvatske, Yugoslavia. The authors thank Dr. N. B. Atkin (Mount Vernon Hospital, Northwood, England) for his useful suggestions.
REFERENCES 1. Atkin NB, Baker MC (1985): Nonrandom chromosome changes in carcinoma of the cervix uteri. I. Nine near-diploid tumors. Cancer Genet Cytogenet 7:209-222. 2. Atkin NB, Baker MC (1981): A metastatic malignant melanoma with 24 chromosomes. Hum Genet 58:217-219. 3. Atkin NB, Baker MC (1978): Duplication of the long arm of chromosome 1 in a malignant tumour. Br J Cancer 38:468-471, 4. Atkin NB, Baker MC (1979): Chromosome 1 in 26 carcinomas of the carvix uteri. Cancer 44:604-613. 5. Anglani F, Artifoni L, Zanesco L, Baccichetti C, Tencor R (1981): Trisomy lq and hematologic disorders. Cancer Genet Cytogenet 4:275-279. 6. Oshimura M, Sonta S, Sandberg AA (1976): Trisomy of the long arm of chromosome 1 in human leukemia. ] Natl Cancer Inst 56:183-184.
Marker lq+
in ANLL
255
7. Kakati S, Barcos M, Sandberg AA (1980): Chromosomes and causation of h u m a n cancer and leukemia. XLL. Cytogenetic experience with non-Hodgkin, non-Burkitt lymphomas. Cancer Genet Cytogenet 2:199-220. 8. Gardner AH, Gallie BL, Knight LA, Phillips RA (1982): Multiple karyotypic changes in retinoblastoma tumor cells: Presence of normal chromosome no. 13 in most tumors. Cancer Genet Cytogenet 6:201-211. 9. Mamaeva SE, Mamaeva NN, Jartseva NM, Belyaeva LV, Scherbakova EG (1983): Complete or partial trisomy for the long arm of chromosome 1 in patients with various hematologic malignancies. Hum Genet 63:107-112. 10. Britto-Babapulle V, Atkin NB (1981): Break points in chromosome 1 abnormalities of 218 h u m a n neoplasms. Cancer Genet Cytogenet 4:215-225. 11. Morris CM, Fitzgerald PH, Neville MA, Wyld PJ, Beard MEJ (1984): Does multisomy of chromosome l q confer a proliferative advantage in B-cell acute lymphoblastic leukemia? Cancer 54:48-53. 12. Papenhausen PR, Wolkin-Friedman E, Pekzar-Wissner C (1984): Novel tandem triplication of lq in a patients with a myelodysplatic syndrome. Cancer Genet Cytogenet 12:145-150. 13. Knuutila S, Ruutu T, Partanen S, Vuopio P (1983): Chromosome l q + in erythroid and granulocyte-monocyte precursors in a patient with essential thrombocythemia. Cancer Genet Cytogenet 9:245-249. 14. Pall ML (1981): Gene-amplification model of carcinogenesis. Proc Natl Acad Sci USA 78:2465-2466. 15. Doneda L, Di Renzo MF, Comoglio PM, Larizzo L (1985): Role of heterochromatin variation in the instability of marker chromosome during tumor progression. Cancer Genet Cytogenet 15:283-291.
ABSTRACT: This paper presents the results of a cytogenetic analysis on a patient with acute lymphocytic leukemia (ALL) type L2 according to the FAB classification. Of the metaphases examined, 69.3% belong to the aberrant clone of pseudodiploid karyotype. Marker chromosome 14q+ has been identified in all the cells of the clone. Duplication was found in 30% of the metaphases, and in 15% triplication of the proximal segment of the long arm of chromosome #1 (ql 1-q21). In one metaphase the long arm of chromosome #1 is made up of segment q11q21 four times repeated. Aberrations of chromosome #1 support the idea that heterochromatic region may be related to the higher degree of the cell malignity.
INTRODUCTION Aberrations of chromosome #1 frequently accompany malignant transformation. They have been found in both malignant hemopathies and in solid tumors in humans [1-8]. This wide range of human neoplasms with chromosome #1 aberrations suggests that they are not a primary disorder in the process of malignant transformation, but are probably of secondary in nature and appear in the course of clonal evolution [6, 9-11]. This report presents a case of lymphocytic leukemia with tandem duplication and triplication of the proximal segment of the long arm of chromosome #1, which appeared in the course of clonal evolution. MATERIALS A N D METHODS
Cytogenetic analysis of malignant cells was carried out immediately after the diagnosis had been made and before initiating therapy. Preparations obtained after 24hour peripheral blood cell culture without mitogen stimulation were used. Chromosome identification was made by applying GTG and BCG bending methods. Besides the cytogenetic analysis of the malignant cell population, determination of the patient's constitutional karyotype was also carried out on a routine lymphocyte culture method stimulated with PHA.
From the Institute for Mother and Child Health (I. P., M. N.), the Division of Hematology and Oncology ~alata, Department of Pediatrics, Faculty of Medicine (A. T., J. K., L. R., R. F-K.), and the Department of Oncology and Radiotherapy, Medical Faculty (M. K.), University of Zagreb, Zagreb, Yugoslavia.
Address requests for reprints to Dr. Iskra Petkovi~, Svearova 5, 41000 Zagreb, Yugoslavia. Received December 2, 1985; accepted February 18, 1986.
251 © 1987 Elsevier Science Publishing Co., Inc. 52 Vanderbilt Ave., New York, NY 10017
Cancer Genet Cytogenet 24:251-255(1987) 0165-4608/87/$03.50
252
I. Petkovid et al.
CASE HISTORY
The patient was a 14.5-year-old boy admitted to the hospital for poor general health, exhaustion, edema of the eyelids, weight loss, pain in the knees and below the rib arches, and enlarged liver, spleen, and lymph nodes. On admission the number of leukocytes in the peripheral blood was 6.2 x 109/L with 0.12 lymphoblasts. In the bone marrow 90% of the cells were found to fulfill the criteria of L2 lymphoblasts, according to the FAB classification. Other lines of hematopoiesis were almost completely repressed and there was no thrombocytopoiesis. Cytochemical investigations showed that the cells were periodic acid-Schiff, peroxidase, and esterase negative, but acid phosphatase was positive. High-risk group anti-leukemia therapy was given. After 3.5 months the boy was in good condition in complete hematologic
G-banded karyotype of a leukemic cell: 46,XY,trip (1)(qllq21),14q +.
Figure 1
1
2
3
4
5
i{ i} i( 1| ii C! Ii 6
7
8
II !i It 13
14
ii ell 19
20
15
9
10
11
12
¢i il N 16
~ 21
17
18
ie, ~e 22
X y
253
Marker l q + in ANLL
Figure 2
Partial karyotypes of G-banded leukemic cells showing duplication (A), triplication (B), and quadruplication (C) of bands q l l to q21 on chromosome #1. A normal chromosome #1 is on the left side in each pair. remission and was discharged from hospital. He was readmitted shortly thereafter, however, in a deteriorated condition with a profound pancytopenia. The clinical condition of the patient did not improve with a fast lethal outcome of the disease.
RESULTS AND DISCUSSION Cytogenetic investigation on a lymphocyte culture stimulated by PHA revealed a normal constitutional karyotype. The modal n u m b e r of malignant cell chromosomes was 46. A total of 41 metaphases was analyzed. Twelve cells (30.7%) had a normal karyotype, whereas, 69.3% of the metaphases belonged to an aberrant clone with a pseudodiploid karyotype. GTG b a n d i n g methods revealed a structural disorder of chromosomes #1 and #14. A marker chromosome, 1 4 q + , was present in all cells of the clone, whereas, in eight metaphases (20.5%) this was the only chromosome disorder. It was not possible to determine the origin of the excess material on chromosome # 1 4 (Fig. 1). Aside from chromosome 1 4 q + , a structural anomaly of chromosome #1 was also found in 19 cells. By precise analysis of the band pattern of the long arm of the aberrant chromosome, duplication was identified in some cells and in others triplication of the 1q11-q21 segment (Fig. 2). The proximal segment of the long arm of chromosome #1 (i.e., a segment of the constitutive heterochromatin] was affected by duplication of triplication, which was confirmed with a BCG b a n d i n g method (Fig. 3). Duplication was found in 12 (30.7%) and triplication in six metaphases (15.3%) examined. In one metaphase an aberrant chromosome #1 with an interesting G-banding pattern was identified, It seems that the long marker arm was made up of the 1q11-q21 segment repeated four times,
254
I. Petkovi~ et al.
V
Figure 3 Partial karyotype of three C-banded malignant cells (duplication A, triplication A). whereas, the distal part of the long arm (1q21-qter) was lost. Two metaphases had a tetraploid n u m b e r of chromosomes but, due to the poor quality of the metaphases, they could not be karyotyped. Only two descriptions of tandem triplications of the long arm of chromosome #1 have been found in the literature. P a p e n h a u s e n et al. and K n u u t i l a et al. have identified tandem triplication q21-q32 in the case of myelodysplastic syndrome and essential thrombocythemia, respectively [12, 13]. In our case of A L L - - i n addition to the marker 14q + - - d u p l i c a t i o n , triplication, and quadruplication of a segment of the long arm of chromosome #1, ranging from band q l l to q21, has been established. Marker chromosome distribution in the malignant cell population indicated instability and a gradual a c c u m u l a t i o n and higher complexity of structural chromosome aberrations. Chromosome dup(1) is unstable and prone to further changes, which is indicated by the existence of a marker with segment triplication or a marker where the segment is repeated four times. The m e c h a n i s m responsible for multiplication may be that suggested by Pall [14]. It is of interest that the region of chromosome #1 involved in the multiplication comprised the segment of constitutive heterochromatin. Doneda et al. suggested that elimination or relocation of heterochromatic regions may favor tumor progression [15]. Thus, the finding suports the idea that heterochromatic region may favor a higher degree of malignancy. Supported by Grant 59 from Samoupravna interesna zajednica za znanstveni rad u oblasti zdravstva SR Hrvatske, Yugoslavia. The authors thank Dr. N. B. Atkin (Mount Vernon Hospital, Northwood, England) for his useful suggestions.
REFERENCES 1. Atkin NB, Baker MC (1985): Nonrandom chromosome changes in carcinoma of the cervix uteri. I. Nine near-diploid tumors. Cancer Genet Cytogenet 7:209-222. 2. Atkin NB, Baker MC (1981): A metastatic malignant melanoma with 24 chromosomes. Hum Genet 58:217-219. 3. Atkin NB, Baker MC (1978): Duplication of the long arm of chromosome 1 in a malignant tumour. Br J Cancer 38:468-471, 4. Atkin NB, Baker MC (1979): Chromosome 1 in 26 carcinomas of the carvix uteri. Cancer 44:604-613. 5. Anglani F, Artifoni L, Zanesco L, Baccichetti C, Tencor R (1981): Trisomy lq and hematologic disorders. Cancer Genet Cytogenet 4:275-279. 6. Oshimura M, Sonta S, Sandberg AA (1976): Trisomy of the long arm of chromosome 1 in human leukemia. ] Natl Cancer Inst 56:183-184.
Marker lq+
in ANLL
255
7. Kakati S, Barcos M, Sandberg AA (1980): Chromosomes and causation of h u m a n cancer and leukemia. XLL. Cytogenetic experience with non-Hodgkin, non-Burkitt lymphomas. Cancer Genet Cytogenet 2:199-220. 8. Gardner AH, Gallie BL, Knight LA, Phillips RA (1982): Multiple karyotypic changes in retinoblastoma tumor cells: Presence of normal chromosome no. 13 in most tumors. Cancer Genet Cytogenet 6:201-211. 9. Mamaeva SE, Mamaeva NN, Jartseva NM, Belyaeva LV, Scherbakova EG (1983): Complete or partial trisomy for the long arm of chromosome 1 in patients with various hematologic malignancies. Hum Genet 63:107-112. 10. Britto-Babapulle V, Atkin NB (1981): Break points in chromosome 1 abnormalities of 218 h u m a n neoplasms. Cancer Genet Cytogenet 4:215-225. 11. Morris CM, Fitzgerald PH, Neville MA, Wyld PJ, Beard MEJ (1984): Does multisomy of chromosome l q confer a proliferative advantage in B-cell acute lymphoblastic leukemia? Cancer 54:48-53. 12. Papenhausen PR, Wolkin-Friedman E, Pekzar-Wissner C (1984): Novel tandem triplication of lq in a patients with a myelodysplatic syndrome. Cancer Genet Cytogenet 12:145-150. 13. Knuutila S, Ruutu T, Partanen S, Vuopio P (1983): Chromosome l q + in erythroid and granulocyte-monocyte precursors in a patient with essential thrombocythemia. Cancer Genet Cytogenet 9:245-249. 14. Pall ML (1981): Gene-amplification model of carcinogenesis. Proc Natl Acad Sci USA 78:2465-2466. 15. Doneda L, Di Renzo MF, Comoglio PM, Larizzo L (1985): Role of heterochromatin variation in the instability of marker chromosome during tumor progression. Cancer Genet Cytogenet 15:283-291.