Identification of a consistent breakpoint at chromosome 6q11 in human follicular lymphoma by chromosome microdissection

143

Abstracts

A

11

NOVEL TYPE OF JUMPING IN A DESMOID TUMOR

TRANSLOCATION

Krzvsztof Mr6zeli. Nikolaus Blin. Constantine P. Karikousis, Karlheinz Holzmann; Carlos Perez-Mesa, and Clara D. Bloomfield. Cvtogenetics Research Laborator) (K.M.), Division of Medicine (K.M., C.D.B.). Departments of Sur ical Oncology (C.P.K.), and Pathology (C.P-M.), Roswel K Pzrk Cancer Institute, Buffalo, NY: Division of Molecular Genetics (N.B., K.H), University of Tiibingen, Tiibingen, Germany. Cytogenetic analvsis of a short-term culture from a retroperitoneal desmdid tumor resected from a 2 l-year-old woman with Gardner’s syndrome revealed a unique type of jumping translocation. Chromosome segments lql2+qter, Zpll.Z+pter, Bqll.l+qter, and 12ql2qqter were each translocated onto telomeric band 20q13.3 in J different clones. This resulted in a trisomy lq, Zp, 8q and 12q, respectively. The fifth clone displayed +5 in addition to der(20)t(l;2O)(ql2;ql3.3), and the sixth clone had r(20) (p13q13.3) as a solitary change. Additionally, translocations ?lOqll~qter. between 20q13.3 and se mems 5 ll-qqter, ” fragments lSqll+qter and two unl .c!entlfled cx romosome telomeric were found in sin le cells. In a few metaphases, associations were aPso observed. The length of the telomeric DNA re eats, assessed using a (TTAGGG)3 o!igonucleotide ybe, d?Id not appear to have been reduced m this tumor. he common feature of jumping translocations reported ic malignancies and solid tumors has thus far in hematolo ment, most frequently been that the same c onto telomeric regions 1 1 I-21-qter, has been translocate o s several different chromosomes. In contrast, in our case, there is only one recipient chromosome, 20q13.3, and several donor chromosomes. The breakpoints in these chromosomes are localized in or in the vicinity of heterochromatic regions suggestin the existence of homologies between pericentric !l eterochromatin of chromosomes 1, 2, 5, 8, 10, 12, 15 and the telomeric chromatin of 2Oq.

AND EXPRESSION Al3 LOCALIZATION OF A MICRODISSECTED DOUBLE

PATTERN MINUTE : CHROMOSOME FROM A COLON CANCER CELL LINE. Eckhardt. S.G.. Mattern. V.. Van Den Berg, C.L..

A12

Guan, X-Y.1 Treni. JM

Deletion of the long arm of chromosome 6 is the second most common chromosomal alteranon in human follicular lymphoma. Previous cyrogenetic analysis suggested that the breakpomts of these delenons cluster around 6q 1%q2 1, Recently. we have used Micro-FISH strategy which combmes chromosome nucrodtssection and fluorescence in situ hybridization techniques 10 detect SIXpnmary follicular lymphoma cases with delenons involving the long arm of chromosome 6 In order 10 deternune rhe exact location of breakpomts. The results showed all these chromosomal deletions mvolvmg 6q are acmally nonreclprocal tramlocations (two cases) or mterstltial deletions (four cases) mvolvmg chromosome 6. Breakpoints on chromosome 6 in 416 cases appear consistent and have been locahzed 10 6q 1 I. Breakpoints in the other two cases are also near to 6q 1 I. BreakpoInts mvolvmg the other pan of chromosome 6 In mlerstmal deletron cases are varied. Based on the observanon thar several tumor suppressor genes have been found by analysis of consIstem breakpoints, it 1s possible that a

tumor suppressor gene IS localized on 6q 11 which is inactivated by chromosomal breakage In follicular lymphomas.

Al4 IDENTIFICATION FROM

B.F.. Chang. D.. Dal. A.. Hodpe. J.. and ticGill. J.R. Cancer Therapy & Research Center. and The University

dmin chromosomes were microdissected and PCR-amplified usin@ the universal degenerate oligomer primer sequence of Telenius (Genes Chromosomes and Cancer 4:257. 1992). A

preamplification protocol using SequenaseO as described by Zhang (Oncogene 8:2827. 1993) was followed. Secondary PCR reactions with biotin-labeled nucleotide precursors provided probes for fluorescent in sifu hybridization (FISH) studies. The dmin-derived probe was hybridized 10 NC1 H508 spreads to confirm the sequence derived from dmins. FISH analysis with the probe to normal peripheral blood lymphocytes localized the probe to 14ql3.1. Known genes in this area include the human homologue of the retroviral oncogene qin. nucleoside phosphorylase, and the somatostatin receptor. Northern analysis using the dminderived probe revealed the expression of specific transcripts in several human tumor cell lines. but not in normal human tissue. Microdissection and PCR-amplification of dmins is an important methodological approach to identifying cancerrelated genes in which are expressed in cell lines and in primary tumors.

Zhantz. HE.1 Horsman. D.2 Meltzer. PS.1 and

I

NatIonal Insmutes of Health. NatIonal Center for Human Genome Research. Laboratory of Cancer Genetics. Bethesda, MD 208921: Cytogenenc and Molecular Genetrc Laboratory. British Columbia Cancer Agency. Vancouver. British Columbia V5Z 4E6.2

Beltzel.

of Texas Health Science Center at San Antonio. San Antonio, TX 78229. Double minute chromosomes (dmms.1 lack centromeres: therefore. the persistence of these suuctures in continuous cultured cell lines imphes dmins contain expressed genes which impart a selective growth advantage us the cells which harbor them. To characterize these genes. the technique of chromosomal microdissection was used on dmins from the colon adenocarcinoma cell line. NC1 H508. Two 10 five

identification of a Consistent Breakpoint at Chromosome 6qll in Human ~Follicular Cymphama by Chromosome Microdissection

OF MARKER

HUMAN

GASTRIC

MICRODISSECTED

CllROMOSOMES

CARCINOMA

CHROMOSOhlE

USING

FRAGMENTS

Ii. T. Klhl. D. K. KIM, I J. CHOI. I. I1 LEE. S 1. CHANG DEPARTMENT

OF ANATOhlY

SCHOOL OF MEDICINE TAEGU. KOREA We have established derived This

from

a

abnormahties

Among

(lp-.

UNIVERSITY

a gastric cancer cell line that was

moderate

cell line has

AND MEDICAL GENETICS KEIhWUh’G

several

differentialed

adenocarcinoma.

kinds of clonal chromosomal

lq+. 3q+, 5p-.

ip+, 9p*.

14p*,

15p+).

them abnormalities of chromosome 1 and 3 were

appeared

above

passages.

To

chromosomes

90%

continuously

in

vitra

cultivation

analysis chromosome 1 derivative

marker

and the ongm of a chromosome fragment

that translocated

to long arm terminal of chromosome 3.

we carned out microdissection on the normal long arms of chromosomes l(lq31->lqter). on abnormal 3q* chromosomes

and normal chromosomes 16

microdissected fragments

These

two

were amplified and labelled with

biotin by PCR. For chromosome paintmg. we hybridized lq and 3q+ probe on chromosomes of gastnc cancer cells and

normal

chromosomes

respecuvelv.

We

could find

several kmds of structural abnormahties of chromosome 1 The

most

common

dup(ll(c&?->qlZ).

abnormaliues

del( ll(p221,

inv

were

del(l)(pl31.

Marker

chromosome founded on long arm terminal of chromosome 3

was

translocated

chromosome 16.

fragment

from

long

arm

of