Comparative genomic hybridization reveals non-random chromosomal aberrations in early preinvasive cervical lesions

doi:10.1016/S0165-4608(01)00424-1

Cancer Genetics and Cytogenetics

Volume 129, Issue 1, August 2001, Pages 47-51

https://doi.org/10.1016/S0165-4608(01)00424-1 Get rights and content

Abstract

We performed CGH analysis on 34 cervical lesions, which included 8 cases of koilocytosis, 6 mild dysplasias and 20 moderate dysplasias. Chromosome aberrations were detected in 11 cases of which 9 were moderate dysplasias. A total of 55 chromosome arms were involved. The most frequent aberrations were losses of 5p and Xq, each of which was present in 5/34 cases. Gain of 3q was detected in two moderate dysplasias. This aberration is the most frequent copy number change in advanced-stage cervical carcinoma. A considerable number of the aberrations found in the preinvasive cases of this study are frequently present in invasive cervical tumors. The presence of apparently non-random chromosome aberrations in early preinvasive cervical lesions has not previously been described.

Introduction

Cervical cancer and preinvasive neoplasia constitute a major public health problem worldwide. Infection with human papillomavirus (HPV) is considered to be the major etiologic factor in cervical carcinogenesis. However, most HPV-induced cervical lesions are reversible [1] and for malignant transformation to occur, it is almost certain that additional somatic events are required. Such events may be chromosomal aberrations affecting tumor suppressor genes or cellular oncogenes. According to the multistep nature of carcinogenesis, cervical lesions should have a sequential accumulation of genetic changes as they progress toward malignancy and invasion. It is, therefore, important to the understanding of cervical carcinogenesis that recurrent chromosomal aberrations are identified.

Comparative genomic hybridization (CGH) is a molecular cytogenetic screening technique that reveals copy number changes. The technique has been applied on cervical cancers in several studies, all of which showed that a pattern of recurrent chromosomal aberrations is present in these tumors 2, 3, 4, 5, 6. In the majority of these studies overrepresentation of sequences from 3q was the most frequent finding in invasive cervical tumors. On this basis it has been hypothesized that the gain of 3q defines the transition from preinvasive to invasive cervical tumors 2, 3, 7, 8.

We have, however, shown that overrepresentation of 3q is already present in severe dysplasias/CIS (35%) [5]. In the present study, we performed CGH on mild and moderate dysplastic cervical lesions in order to investigate whether chromosomal imbalances are present at even earlier stages. Specific chromosomal markers may be indicators for the probability of a lesion to progress to invasive cancer. The CGH analyses showed that a gain of 3q is present in some moderately dysplastic cervical lesions and so are a number of other chromosomal aberrations.

Section snippets

Tumor specimens

A total of 34 samples was analyzed. All samples were classified according to the International Federation of Gynecology and Obstetrics (FIGO) criteria. The preinvasive lesions consisted of 8 cases of koilocytosis 6 cases of mild dysplasia and 20 cases of moderate dysplasia. All samples were formalin-fixed and paraffin-embedded. Samples were examined microscopically and tissue (approximately 2–3 mm³) was selected from regions that showed dysplastic or koilocytotic cells. DNA from all samples was

Results

CGH analysis was performed on 34 samples, which included 8 cases of koilocytosis, 6 mild dysplasias and 20 moderate dysplasias. The combined results of all analyses are shown in Fig. 1A.

Eleven of the cervical lesions (1 case of koilocytosis, 1 mild dysplasia and 9 moderate dysplasias) showed copy number changes ranging from 1–14 involved chromosome arms per case. The specific aberrations found in each case are listed in Table 1, and the CGH analysis of the moderate dysplasia showing gains of

Discussion

In this work, we performed CGH analysis on a number of cases of koilocytosis and mild and moderate dysplastic cervical lesions in order to identify potential characteristic chromosomal changes. A non-random pattern of chromosomal markers might be a powerful tool to predict the progressive potential of preinvasive lesions. The results showed that approximately one-half of the moderate dysplasias had chromosomal changes involving 1–14 chromosome arms.

This contrasts a study by Heselmeyer et al. [2]

Acknowledgements

Supported by The Danish Cancer Society.

References (21)

N. Brass et al.
DNA amplification on chromosome 3q26.1∼q26.3 in squamous cell carcinoma of the lung detected by reverse chromosome painting
Eur J Cancer
(1996)
M. Sugita et al.
Molecular definition of a small amplification domain within 3q26 in tumors of cervix, ovary and lung
Cancer Genet Cytogenet
(2000)
S.C. Rubin et al.
Cervical cancer and preinvasive neoplasia
(1996)
K. Heselmeyer et al.
Gain of chromosome 3q defines the transition from severe dysplasia to invasive carcinoma of the uterine cervix
Proc Natl Acad Sci USA
(1996)
K. Heselmeyer et al.
Advanced-stage cervical carcinomas are defined by a recurrent pattern of chromosomal aberrations revealing high genetic instability and a consistent gain of chromosome arm 3q
Genes Chromosom Cancer
(1997)
A. Dellas et al.
Prognostic value of genomic alterations in invasive cervical squamous cell carcinoma of clinical stage IB detected by comparative genomic hybridization
Cancer Res
(1999)
M. Kirchhoff et al.
Comparative genomic hybridization reveals a recurrent pattern of chromosomal aberrations in severe dysplasia/carcinoma in situ of the cervix and in advanced-stage cervical carcinoma
Genes Chromosom Cancer
(1999)
C.P. Matthews et al.
Genomic changes and HPV type in cervical carcinoma
Proc Soc Exp Biol Med
(2000)
T. Ried et al.
Tumor cytogenetics revisitedcomparative genomic hybridization and spectral karyotyping
J Mol Med
(1997)
T. Ried et al.
Genomic changes defining the genesis, progression, and malignancy potential in solid human tumorsa phenotype/genotype correlation
Genes Chromosom Cancer
(1999)

There are more references available in the full text version of this article.

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Chromosomal gains and losses in human papillomavirus-associated neoplasia of the lower genital tract-A systematic review and meta-analysis
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We found that the rates of chromosomal gains and losses at distinct chromosome arms generally increase from low grade CIN, high grade CIN to invasive cervical cancer (Table 2, Fig. 2). It should be noted that the two studies did not find any alteration in low grade CIN [22,23], two studies found very low alteration frequencies [24,25] and most alterations reported for low grade CIN were based on a single study [26]. The most frequent alterations reported in cervical SCC (3q gain, 3p loss, 11p loss) were already detected in high grade CIN, however at significantly lower rates: 3q-gain rate 0.27 (95%CI 0.20–0.36), followed by 11p-loss rate 0.15 (95%CI 0.09–0.24) and less often 3p-losses (rate 0.08, 95%CI 0.04–0.15) (Table 2, Figs. 2 and 3, Supplemental Table 1).
Overexpression of the human papillomavirus (HPV) oncogenes E6 and E7 is necessary for the development of distinct lower genital tract cancers. However, secondary cellular genomic alterations are mandatory to promote progression of HPV-induced premalignant stages. We aimed at identifying the chromosomal regions most frequently gained and lost and the disease stage at which the latter occurs. These regions might be relevant for carcinogenesis and could serve as diagnostic markers to identify premalignant lesions with high progression risk towards invasive cancer.
We performed a systematic literature review and meta-analysis of studies listed in PubMed that analysed chromosomal copy number alterations by comparative genomic hybridisation (CGH) in HPV-positive and -negative cancers or premalignant lesions of the anogenital tract (cervix, anus, vagina, penis and vulva).
Data were extracted and analysed from 32 studies. The most common alterations in cervical squamous cell carcinoma (SCC) (12 studies, 293 samples) were gains at 3q with a rate of 0.55 (95% confidence interval (CI) 0.43–0.70), losses at 3p (0.36, 95%CI 0.27–0.48) and losses at 11q (0.33, 95%CI 0.26–0.43). Gains at 3q were particularly frequent in HPV16-positive cervical SCC (0.84, 95%CI 0.78–0.90). Also more than one quarter of high grade cervical intraepithelial neoplasia (CIN) harboured gains of 3q (0.27, 95%CI 0.20–0.36), but the rate in low grade CIN was low (0.02, 95%CI 0.00–0.09). For HPV-associated vulvar SCC (four studies, 30 samples) the same common alterations as in cervical SCC were reported. Studies on non-cervical and non-vulvar SCC and premalignant lesions of the lower genital tract are scarce.
3q gains were most frequently found in HPV16-positive cervical SCC. The results suggest the selection of HPV-transformed cell clones harbouring 3q gains in high grade premalignant lesions, while alterations in low grade lesions are rare.
Detection of TERC amplification in cervical epithelial cells for the diagnosis of high-grade cervical lesions and invasive cancer: A multicenter study in China
2010, Journal of Molecular Diagnostics
Because the activation of telomerase is a relatively early event in the progression of cervical carcinogenesis, the expression of the human telomerase RNA gene, TERC, has the potential to serve as a biomarker for both the diagnosis and prognosis of cervical neoplasias. In total, 83 research centers participated in the study, and 7786 patients were enrolled. TERC amplification was detected using a dual-color fluorescence in situ hybridization (FISH) probe set, and these results were compared with cytological and histological results, testing for high-risk human papillomavirus (HPV) DNA (n = 2316 for the HPV DNA test), as well as patient age. TERC amplification was found to be increased in more advanced cases of cervical carcinogenesis. Moreover, a Youden's index value and the area under the receiver operating characteristic (ROC) curve were also calculated for samples with TERC amplification and found to be higher than the same values calculated for both cytology and high-risk HPV analyses of the same samples. With regard to cytological ASCUS and LSIL findings, the combination of HPV + TERC testing showed the potential to provide effective triaging to detect CIN2⁺. Therefore, TERC amplification represents a valuable genetic biomarker, which in combination with an evaluation of cytology or HPV testing, can achieve higher sensitivity and specificity in distinguishing high-grade cervical lesions and invasive cancers from low-grade lesions compared with conventional methods.
Chromosome aberrations in solid tumors have a stochastic nature
2006, Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
An important question nowadays is whether chromosome aberrations are random events or arise from an internal deterministic mechanism, which leads to the delicate task of quantifying the degree of randomness. For this purpose, we have defined several Shannon information functions to evaluate disorder inside a tumor and between tumors of the same kind. We have considered 79 different kinds of solid tumors with 30 or more karyotypes retrieved from the Mitelman Database of Chromosome Aberrations in Cancer. The Kaplan–Meier cumulative survival was also obtained for each solid tumor type in order to correlate data with tumor malignance. The results here show that aberration spread is specific for each tumor type, with high degree of diversity for those tumor types with worst survival indices. Those tumor types with preferential variants (e.g. high proportion of a given karyotype) have shown better survival statistics, indicating that aberration recurrence is a good prognosis. Indeed, global spread of both numerical and structural abnormalities demonstrates the stochastic nature of chromosome aberrations by setting a signature of randomness associated to the production of disorder. These results also indicate that tumor malignancy correlates not only with karyotypic diversity taken from different tumor types but also taken from single tumors. Therefore, by quantifying aberration spread, we could confront diverse models and verify which of them points to the most likely outcome. Our results suggest that the generating process of chromosome aberrations is neither deterministic nor totally random, but produces variations that are distributed between these two boundaries.
Study of chromosomal abnormalities in 11 cases of cervical dysplasia using comparative genomic hybridization on cotton-lint cervical samples
2006, Cancer Genetics and Cytogenetics
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Only the Aubele et al. [11] study described a gain of this region, in one out of the three cases studied. Probably, our results are related to the sample analyzed, similar to the study conducted by Aubele et al. [11], which would explain the difference from other studies [3,5–13]. Aubele et al. [11] observed gain in the entire chromosome, and we found a gain only in the region of 4q25.
Comparative genomic hybridization (CGH) allows the analysis of chromosomal imbalances without requiring cell cultures and is more reliable than conventional cytogenetic studies for detecting gains, losses, and amplified regions. To perform CGH on cervical lesions, some authors obtain the tumoral DNA from frozen or paraffin-embedded biopsies. Others use laser microdissected material from paraffin-embedded samples, followed by degenerate oligonucleotide primer-polymerase chain reaction (DOP-PCR). In all these cases, surgery is required to obtain the sample. In our study, we obtained DNA from a cotton-lint cervical sample obtained from the pathological zone using a colposcopy technique. Chromosomal alterations were found in 9 (81%) of the 11 cases analyzed. The most frequent alterations affected the 3p12, 4q25, 5q15∼q21, and 18p11 regions. Satisfactory results have been observed when the cotton-lint cervical sample has been used as the source for obtaining DNA. In the laboratory, the manipulation of this type of sample obtained by a noninvasive system is much simpler, easier, and faster than the obtained with a conventional biopsy.
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Original articleComparative genomic hybridization reveals non-random chromosomal aberrations in early preinvasive cervical lesions

Abstract

Introduction

Section snippets

Tumor specimens

Results

Discussion

Acknowledgements

Eur J Cancer

Cancer Genet Cytogenet

Cervical cancer and preinvasive neoplasia

Gain of chromosome 3q defines the transition from severe dysplasia to invasive carcinoma of the uterine cervix

Proc Natl Acad Sci USA

Advanced-stage cervical carcinomas are defined by a recurrent pattern of chromosomal aberrations revealing high genetic instability and a consistent gain of chromosome arm 3q

Genes Chromosom Cancer

Prognostic value of genomic alterations in invasive cervical squamous cell carcinoma of clinical stage IB detected by comparative genomic hybridization

Cancer Res

Comparative genomic hybridization reveals a recurrent pattern of chromosomal aberrations in severe dysplasia/carcinoma in situ of the cervix and in advanced-stage cervical carcinoma

Genes Chromosom Cancer

Genomic changes and HPV type in cervical carcinoma

Proc Soc Exp Biol Med

Tumor cytogenetics revisitedcomparative genomic hybridization and spectral karyotyping

J Mol Med

Genomic changes defining the genesis, progression, and malignancy potential in solid human tumorsa phenotype/genotype correlation

Genes Chromosom Cancer

Original article
Comparative genomic hybridization reveals non-random chromosomal aberrations in early preinvasive cervical lesions