Direct chromosome analysis of seven primary colorectal carcinomas

Direct Chromosome Analysis of Seven Primary Colorectal Carcinomas Sheng Xiao, Wang Wei, Xing-Lin Feng, Yan-Hua Shi, Quan-Zhang Liu, and Pu Li

Chromosome studies were performed on direct preparations of seven cases of primary colorectal carcinomas. Two cases had relatively simple chromosome changes: 4 8 , X Y , + 8 , + 2 1 / 5 1 , XY, + 8, + 9, + 1O, + i(17q), + 21, and 4 7, der(X)t(X; 14)(q 11 ;q 11 ) - Y, t(6;18)(p22 ;q24) + 7, + 8, der(19)t (19;?)(q13;?). The five others had complicated deletions and translocations; l p - was noted in five cases, and i(17q) was noted in three cases. ABSTRACT:

INTRODUCTION

The i n c i d e n c e of colorectal carcinoma differs geographically China is among the low-rate regions in the world, but the i n c i d e n c e is increasing and is now just lower than that of esophageal cancer and gastric cancer among digestive tract tumors. Cytogenetic study of colorectal carcinoma is relatively extensive among solid tumors [1-6]; nevertheless, the often low technical quality of the preparations and the complexity of the chromosome changes lead to varied interpretations. We report the cytogenetic data of seven cases of primary colorectal carcinomas.

longed fixation in this method. Slides were made according to the routine air-drying method. Detailed G-banded chromosome analyses were achieved in seven of 12 cases. Peripheral blood (PB) was examined in two patients to rule out any constitutional abnormalities.

RESULTS

Clinical, pathologic, and cytogenetic findings from seven cases of primary colorectal carcinomas are summarized in Table 1. Case 1

MATERIALS AND METHODS

Fresh tumor tissues were obtained from surgical resections of 12 patients who had had neither chemotherapy nor radiotherapy. T u m o r materials were processed directly for cytogenetic studies with an improved method, as previously described for esophageal cancer [7]. The tissues were finely m i n c e d with scissors, and cell suspensions were made by pipetting a part of the mince into RPMI 1640 culture m e d i u m c o n t a i n i n g Colcemid. The cell suspensions were incubated for 1 hour at 37°C in a water bath, and hypotonic treatment with 0.4% KC1 and 0.4% sodium citrate (1 : 1) was then performed twice. The cells were fixed in methanol :acetic acid (3 : 1) fixative for only 10 minutes before being dropped on slides because previous poor chromosome morphology was considered to result from pro-

From the Medical Genetics Division, Department of Biology, Harbin Medical College (S. X., W. W., Y. H. S., Q. z. L., P. L.), and Kai Feng Obstetrical and Gynecological Hospital (X. L. F.), Harbin, China. Address for reprint requests to Dr. S. Xiao, Medical Genetics Division, Department of Biology, Harbin Medical College, Harbin, China. Received November 6, 1991; accepted April 8, 1992. 32 Cancer Genet Cytogenet62:32-39 (1992) 0165-4608/92/$05.00

Fourteen cells were analyzed in case 1. The karyotype was 48,XY, + 8, + 21(10)/51,XY, + 8, + 9, + 10, + i(17q) + 21,(4) (Figs. 1 and 2). Lymphocyte culture was then started; examinations of 50 metaphases showed a normal male karyotype. Case 2

Twelve cells were analyzed in case 2. The karyotype was 47,der(X;14)(q10;q10), - Y,t(6;18)(p22;q24) + 7, + 8,der (19)t(19;?)(q13;?), (Fig. 3). PB was examined, and a normal male karyotype was present in 50 metaphases. Case 3

Eighteen cells with 4 8 - 5 0 chromosomes were analyzed in case 3. Chromosome 17 was m o n o s o m i c (in 14 cells) or absent (in four cells). Six structurally abnormal chromosomes could be identified (Fig. 4): (a) del(1)(p32); (b) del{6)(q22)×2; (c) del(10)(q24); (d) del(1)[p13); (e) i(8q); and (f) i(17q). Case 4

Eight metaphases with 3 4 - 4 0 chromosomes were studied in case 4. Chromosomes 4, 9, 10, 14, 17, 18, and 20 were usually monosomic, and chromosome 13 was c o m m o n l y <: 1992 Elsevier Science Publishing Co.. Inc. 655 Avenue of the Americas. New York. NY 10010

Papillary adenocarcinoma Adenocarcinoma

Adenocarcinoma

Adenocarcinoma

Mucinous adenocarcinoma

Mucinous adenocarcinoma Adenocarcinoma

1/48/M

3/62/F

4/60/F

5/57/F

6/53/M

7/63/M

2/67/M

Histology

Clinical, histopathologic,

Case/age (yr)/sex

Table 1

Poor

Moderate

Poor

Poor

Moderate

Moderate

Moderate

Degree of differentiation

B

B

A3

B

A3

A3

A2

Dukes stage

Cecum

Cecum

Transverse colon Ascending colon Ascending colon Sigmoide colon Ascending colon

T u m o r site

72-90 (mode 76-78) 47-50

64-140 (mode 80)

34-40

48-50

47

48/51

No. of chronlosomes

der(X;14)(q10;q10), - Y,t(6;18)(p22;q24) + 7, + 8,der(19)t(19;?)(q13;?) - 17,del(1)(p32),del(6)(q22),del(6)(q22/, del(10)(q24). Inset: del(1)(p13),i(8q),i(17q) del(1)(p32), - 4,i(8q) - 9, - 10, + 13,de1(11) (p14) - 1 4 , - 17, - 1 8 , - 20,(not clonal/,i(15qL i(17q), hsr(?) der(1)t(lq;14q/,der(1)t(1;?)(p11;?),der(3)t(3;?) (q11;?/,del(3)(q13),del(4/(q31) × 2,del(4) (q22),der(5)t(1;5)(q25;q35) × 2,inv(8) (p11;q13) × 2,del(9)(q22/,der(12)t(12q;14q/, der(13)t(13;?)(p11;?) Inset: del(1)(p13), der(7)t(7 ;?)(pl i ;?),der(7)t(7;?)(ql 1 ;?), ring del(1)(p11),der(1)t(1;?)(p11;?),del(1)(q11), i(17qL + 1 3 , - 1 4 , - 18, + 20, 22 del(1)(p32),del(2)(p21),del(3)(q11),del(7)(q32), del(11)(q23),i(15q/, ring

+ 8, + 21/+ 8, + 9, + 10,+ i(17q), + 21

Karyotype a b n o r m a l i t i e s

a n d c y t o g e n e t i c f i n d i n g s i n s e v e n c a s e s of p r i m a r y c o l o r e c t a l c a r c i n o m a s

34

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2

3

4

5

ti t1 6

7

41

da

15

l&

t9

~

8

9

10

a~ 15

1!

12

A= t i

16

!7

21

18

22

XY

Figure 1

G - b a n d e d k a r y o t y p e from case i: 47,X,

Y , + 8 , + 2 1 . T h e loss of Y {:hrornosonle w a s r a n d o m

Figure 2

G - b a n d e d k a r y o t y p e from case 1:51,XY,

+

1

6

2

8, + 9 , - 10,

+

i{ 17q),

3

7

+

21.

4

8

9

.5

10

11

16

17 A

12

i J ,ill i~ 13

14

15

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|. 19

20

21

22

XY

Chromosome Analysis of Primary Rectal CA

35

h H 1

2

.5

7

8

H It 6

5

l,t

A

6a

13

1/,

A 19d

20

+7

A b

10

9

16

15

21

+8

22

b

11

12

17

i 18c

XY

c

d

Figure 3

G-banded karyotype from case 2: 47.der(X:14}(q10:q10). - ¥.t(6:18)(q22:q24) ÷ 7, + 8.der(19)t(9:?)(q13:?). Inset: Chromosome changes from another metaphase of this case. For explanation of the markers a through d. see the Results section.

trisomic. Six structurally abnormal chromosomes could be identified (Fig. 5): (a) del(1)(p32); (b) i(8q); (c) del(11)(p14) (not clonal); (d) i(15q); (e) i(17q); and (f) a marker containing homogeneously staining regions (HSR). Case 5

Thirty metaphases were analyzed in case 5. The chromosome number ranged between 64 and 140. The modal number was 80. Chromosomes 10, 14, 18, 21, and 22 were often underrepresented, whereas chromosomes 3, 8, 9, 11, and 13 were usually overrepresented. Fifteen structurally abnormal chromosomes could be identified (Fig. 6): (a) der(1)t(1q;14q); (b) der(1)t(1;?)(p11;?); (c) der(3)t(3;?)(q11;?); (d) del(3)(q13); (e) del(4)(q31)x2; (f) del(4)(q22); (g) der(5)t(1;5)(q25;q35) x 2; (h) inv(8)(pllq13) x 2; (i) del(9) (q22); (j) der(12)t(12q14q); (k) der(13)t(13;?)(p11;?); (1) del(1)(p13); (m) der(7)t(7;?)(p11;?); (n) der(7)t(7;?)(q11;?); and (o) a ring.

Case 6

Twenty-five cells were studied in case 6. The chromosome number varied from 72 to 90. The modal number was 76-78. Chromosomes 14, 18, and 22 were underrepresented, and chromosomes 13 and 20 were constantly overrepresented. Among structurally abnormal chromosomes, four could be identified (Fig. 7): (a) del(1)(p11); (b) der(1)t(1;?)(p11;?); (c) del(1)(q11); and (d) i(17q). Case 7

Sixteen metaphases with 4 7 - 5 0 chromosomes were analyzed in case 7. Most chromosomes were monosomic, and about 30 structurally abnormal chromosomes were present in each cell. Most structurally abnormal chromosomes were extremely complex, and only seven could be identified: (a) del(1)(p32): (b) del(2)(p21): (c) del(3)(q11): (d) del(7)(q32): (e) del(11)(q23); (f) i(15q): and (g) a ring.

36

5;. X i , ,

H

i 1 :a

2

3

5

4

q ii n 6

.1 al.

b

7

8

is 10 C

9

U 13

14

21

19

a

!6

15

1t

12

au

17

18

22

XX

20

MARKERS

iz

d

e

f

Figure 4 G-banded karyotype from case 3. Karyotype details are described in detail in the Results section. Inset: Clonal changes from other metaphases of this case. For explanation of markers a tbrough f, see the Results section.

DISCUSSION A c c o rd i n g to the Muleris classification, three types of colorectal carcinomas with abnormal karyotypes can be defined: the m o n o s o m i c - t y p e near-diploid tumor (MD), the m o n o s o n i c - t y p e p o l y p l o i d tumor (MP), and the trisomictype t u m o r (TT) [8]. In this study, cases 1 and 2 were TT tumors. Both s h o w e d gain of c h r o m o s o m e 8. Case 1 was particularly informative, exhibiting m i n i m a l changes identified as trisomy 8 and 21. This result was similar to two previously reported cases whose karyotypes were 49,XY, + 3, + 8, + 21/46,XY and 50,XX, + 8, + 14, + 21, + mar/ 63,XX, + 2, +4, + 5, + 6, + 8, + 10, + 13,+ 14, + 15, + 16, + 18, + 21, + 21, + 4mar [1]. These abnormalities were obviously n o n r a n d o m and probably indicated a separate cytogenetic subgroup of colorectal carcinoma. In previous studies gain of c h r o m o s o m e 8 was described as one of the most consistent n o n r a n d o m c h r o m o s o m e abnormalities in colorectal carcinoma: Eight of 46 cases had simple gains of c h r o m o s o m e s as the only changes (TT type); six of them had trisomy 8 [1,2]. Trisomy 8 was also c o m m o n

in benign colorectal a d e n o m a [9-11]. The recurrent i n v o l v e m e n t of c h r o m o s o m e 8 both in colorectal adenoma and in colorectal carcinoma may suggest its importance in colorectal tumorigenesis. Muleris et al. reported that a rearrangement of chromosome 17 w h i c h resulted in loss of its short arm and a deficiency of one c h r o m o s o m e 18 were the most frequent c h r o m o s o m e changes in colorectal carcinoma [12-14]. In the present study, i(17q), the most recurrent rearrangement in colorectal carcinoma in the study by Muleris et al [12-14], was noted in four cases. In case 1, i(17q) was present in a subclone and appeared to be a secondary change. A deficiency of one c h r o m o s o m e 18 was also noted in four cases in this study. C h r o m o s o m e 1 was frequently involved in rearrangements in this series; the rearrangements resulted in the loss of its short arm in all five cases except for two TT cases. Frequent rearrangement of c h r o m o s o m e 1 in colorectal carcinoma was also reported in other studies [1, 2, 8].

37

t it i

I

a

L+

2

.|

i

A

A

6

7

8 b

1]

14

d

10

9

20

MARKERS

iJ

cll

12

A

A

19

5

16

21

22

1'7 e

18

XX

A f

: f t 1t a

b

d

e

f

F i g u r e 5 G-banded karyotype from case 4. Karyotype is described in detail in the Results section. Inset: Clonal changes from other metaphases of this case. For explanation of markers a through f, see the Results section.

38

~.lb

2

3

A

AAA

C

e

7

8

A A g

5

A

A

A A

6

f

9

h

i

12J

!1

10

t14 13

k

14

~6

15

||

o

19

22

2t

20

18

17

xx

MARKERS

a|t et~ ~, o i

m

n

o

F i g u r e 6 G-banded karyotype from case 5. Karyotype is described in detail in the Results section. Inset: Clonal changes from other metaphases of this case. For explanation of markers a through o, see the Results section.

Chromosome Analysis of Primary Rectal CA

39

tl, AAA 1 ab

6

7

5

3

2

c

8

9

12

11

10

|e t3

19

1.5

20

16

21

t| A 17 d

22

18

XY

MARKERS

Figure 7

G-banded karyotype from case 6. Karyotype (markers a through d) is described in detail in the Results

section.

REFERENCES 1. Sonta S, Sandberg AA (1978): Chromosomes and causation of h u m a n cancer and leukemia. XXX. Banding studies of primary intestinal tumors. Cancer 41:164-173. 2. Reichmann A, Martin P, Levin B (1981): Chromosomal banding patterns in h u m a n large bowel cancer. Int J Cancer 28:431-440. 3. Ochi H, Takeuchi J, Holyoke D, Sandberg AA (1983): Possible specific chromosome changes in large bowel cancer. Cancer Genet Cytogenet 10:121-122. 4. Pathakv S, Goodacre A (1986): Specific chromosome anomalies and predisposition to h u m a n breast, renal cell, and colorectal carcinoma Cancer Genet Cytogenet 19:29-36. 5. Ferti AD, Panani AD, Raptis S (1988): Cytogenetic study of rectosigmoidal adenocarcinomas. Cancer Genet Cytogenet 34:101-109. 6. Yaseen NY, Watmore AE, Potter AM, Potter CW, Jacob G, Rees RC (1990): Chromosome studies in eleven colorectal tumors. Cancer Genet Cytogenet 44:83-97. 7. Xiao S, Feng XL, Geng JS, Yan FC, Liu QZ, Li P (1991): Cytogenetic studies of five primary esophageal cancers. Cancer Genet Cytogenet 55:197-205.

8. Muleris M, Salmon RJ, Dutrillaux B (1990): Cytogenetics of colorectal adenocarcinomas. Cancer Genet Cytogenet 46:143-156. 9. Mitelman F, Mark J, Nilsson PG, Dencker H, Norryd C, Tranberg KG (1974): Chromosome banding pattern in h u m a n colonic polyps. Hereditas 78:63-68. 10. Reichmann A, Martin P, Levin B (1982): Karyotypic findings in a colonic villus adenoma. Cancer Genet Cytogenet 7:51-57. 11. Reichmann A, Martin P, Levin B (1985): Chromosomal banding patterns in h u m a n large bowel adenomas. Hum Genet 70:28-31. 12. Muleris M, Salmon RJ, Zafrani B, Girodet J, Dutrillaux B (1985): Consistent deficiencies of chromosome 18 and of the short arm of chromosome 17 in eleven cases of h u m a n large bowel cancer: A possible recessive determinism. Ann Genet 28:206-213. 13. Muleris M, Salmon RJ, Dutrillaux AM, Viehl P, Zafrani B, Girodet I, Dutrillau× B (1987): Characteristic chromosomal imbalance in 18 near-diploid colorectal tumors. Cancer Genet Cytogenet 29:289-301. 14. Muleris M, Delattre O, Olschwang S, Dutrillaux AM, Remvikos Y, Salmon RJ, Thomas G, Dutrillaux B (1990): Cytogenetic and molecular approaches of polyploidization in colorecta] adenocarcinomas. Cancer Genet Cytogenet 44:107-118.