Abnormalities of chromosome 22 in meningiomas and confirmation of the origin of a dicentric 22 by in situ hybridization

Endometriosis: a new cellular and molecular genetic approach for understanding the pathogenesis and evolutivity

Endometriosis is a benign disease with high prevalence in women of reproductive age estimated between 10 and 15% and is associated with considerable morbidity. Its etiology and pathogenesis are controversial but it is believed to involve multiple genetic, environmental, immunological, angiogenic, and endocrine processes. Altered expressions of growth factors, cytokines, adhesion molecules, matrix metalloproteinases, and enzymes for estrogen synthesis and metabolism have been frequently observed in this condition. The possibility of genetic basis of endometriosis is demonstrated in studies of familial disease, in which the incidence of endometriosis is higher for first-degree relatives of probands as compared to controls. This review describes mainly the cellular, cytochemical, cytogenetic, and molecular genetic features of endometriotic lesions and cultured endometriotic cells. In attempts to identify candidate gene (s) involved in the pathogenesis of endometriosis, a tissue-based approaches including conventional cytogenetics (RHG-banding), loss of heterozygosity (LOH), and comparative genomic hybridization (CGH) were employed. In addition to the karyotypic anomalies, consistent chromosome instability was confirmed by CGH and fluorescence in situ hybridization (FISH). The nature and significance of the molecular genetic aberrations in relation to the locations and function of oncogenes and tumor suppressor genes will be discussed. At last, a possible pathogenic role of embryonic duct remnants was observed in seven female fetal reproductive tract in endometriosis and may induce a discussion about the beginning of ovarian tumors and malignant proliferations.

Hormonal suppressive therapy for endometriosis may not improve patient health

OBJECTIVE

To critically examine the possible association between hormonal treatment of endometriosis and ovarian cancer.

RESULT(S)

The malignant potential of endometriosis has been suggested by several clinical studies. Although controversial, ovarian carcinoma of the endometrioid and clear cell subtypes has been associated with endometriosis, particularly among subjects with a longstanding disease. Furthermore, a significantly higher frequency of endometriosis has been found in patients undergoing surgery for endometrioid, clear cell, and mixed subtypes of ovarian carcinoma, as compared with the other subtypes. Changes in the genomic material in endometriotic implants were observed by many investigators in chromosomes 1, 5, 6, 7, 16, and 22 by several methods (fluorescent in situ hybridization, comparative genomic hybridization, and others). Because hormonal ablative treatments may suppress the normal, eukaryotic cells more than the aneuploid cells bearing chromosomal aberrations, it may increase the rate of dyskaryotic cells in the endometriotic implants, possibly augmenting the risk of malignant transformation. A recent published association between Danazol and ovarian cancer suggests that such a theoretical risk may occur.

CONCLUSION(S)

The hormonal ablative treatment of endometriosis may increase the risk of malignant transformation in the endometriotic implants by causing a negative selection and increasing the rate of dyskaryosis and loss of heterozygosity.

Structural and numerical aberrations of chromosome 22 in a case of follicular variant of papillary thyroid carcinoma revealed by conventional and molecular cytogenetics

This study reports a case of papillary carcinoma with vesicular components showing multiclonal aberrations of chromosome 22 as revealed by RHG-banding cytogenetics and by fluorescence in situ hybridization (FISH; whole chromosome 22 and BCR-ABL-specific locus probes, multi-FISH). Four clones with chromosome 22 changes as the sole abnormality were seen. The main abnormal clone lacked the whole chromosome 22. A del(22)(q11) was observed in a second group of cells. The third clone had an idic(22). Finally, FISH revealed a fourth abnormal cell population with a der(17)t(?17;22). Some of these chromosome 22 alterations have been described in other solid tumors such as meningiomas and neurinomas, suggesting a common genetic pathway of tumor progression occurring in a multistep process. Chromosome 22 changes do not seem to be involved in pure papillary thyroid tumors and therefore could be related to the maintenance of a follicular-type histological pattern.

DNA copy number changes in thyroid carcinoma

The genetic changes leading to thyroid cancer are poorly characterized. We studied DNA copy number changes by comparative genomic hybridization (CGH) in 69 primary thyroid carcinomas. In papillary carcinoma, DNA copy number changes were rare (3 of 26, 12%). The changes were all gains, and they were associated with old age (P = 0.01) and the presence of cervical lymph node metastases at presentation (P = 0.08). DNA copy number changes were much more frequent in follicular carcinoma (16 of 20, 80%) than in papillary carcinoma (P < 0.0001), and follicular carcinomas had more often deletions (13/20 versus 0/26, P < 0.0001). Loss of chromosome 22 was common in follicular carcinoma (n = 7, 35%), it was more often seen in widely invasive than in minimally invasive follicular carcinoma (54% versus 0%, P = 0.04), and it was associated with old age at presentation (P = 0.01). In three of the four patients with follicular carcinoma who died of cancer, the tumor had loss of chromosome 22. DNA copy number changes were found in 5 (50%) of the 10 medullary carcinomas studied. Four of these five carcinomas had deletions, and in two of them there was deletion of chromosome 22. Eleven (85%) of the thirteen anaplastic carcinomas investigated had DNA copy number changes, of which five had deletions, and one had deletion of chromosome 22. The most common gains in anaplastic carcinoma were in chromosomes 7p (p22-pter, 31%), 8q (q22-qter, 23%), and 9q (q34-qter, 23%). We conclude that DNA copy number changes are frequent in follicular, medullary, and anaplastic thyroid carcinoma but rare in papillary carcinoma when studied by CGH. Loss of chromosome 22 is particularly common in follicular carcinoma, and it is associated with the widely invasive type.

Comparison of benign and malignant follicular thyroid tumours by comparative genomic hybridization

DNA copy number changes were compared in 29 histologically benign follicular adenomas, of which five were atypical, and 13 follicular carcinomas of the thyroid by comparative genomic hybridization. DNA copy number changes were frequent in adenomas (14 out of 29, 48%). Most changes were gains, and they always involved a gain of the entire chromosome 7 (10 out of 29, 34%); other common gains involved chromosomes 5 (28%), 9 (10%), 12 (24%), 14 (21%), 17 (17%), 18 (14%) and X (17%). Losses were found only in four (14%) adenomas. Two of the five atypical adenomas had DNA copy number losses, and none had gains. Unlike adenomas, gains were rare and losses were frequent in carcinomas. A loss of chromosome 22 or 22q was particularly common in carcinomas (6 out of 13, 46%), whereas a loss of chromosome 22 was found in only two (7%) adenomas, one of which was atypical (P = 0.002). A loss of 1p was also frequent in carcinomas (31%), but gains of chromosomes 5, 7, 12, 14 or X that were common in adenomas were not found. Loss of chromosome 22 or 22q was present in six of the eight widely invasive follicular carcinomas, but in only one of the five minimally invasive carcinomas. We conclude that large DNA copy number changes are common in thyroid adenomas. These changes are strikingly different from those found in follicular carcinomas consisting of few losses and frequent gains, especially those of chromosome 7. A loss of chromosome 22 is common in widely invasive follicular carcinoma.

Dosimetric and cytogenetic studies of multiple radiation-induced meningiomas for a single patient

No criteria are currently available to determine the spontaneous or radiation-induced origin of a malignant tumor occurring in a previously irradiated area. This study presents the dosimetric and cytogenetic analysis of meningiomas diagnosed in irradiated brain areas from a single patient and a discussion of the karyotypes of spontaneous meningiomas and radiation-induced tumors published in the literature.

Report of a complex karyotype in recurrent metastatic fibrolamellar hepatocellular carcinoma and a review of hepatocellular carcinoma cytogenetics

Metastatic fibrolamellar hepatocellular carcinoma (HCC) was detected in the abdominal lymph nodes of an adolescent male after resection of the primary tumor. No dividing cells were isolated from attempted cytogenetic studies of the primary tumor. However, cytogenetic analysis of lymph node metastases detected 9 and 12 months after partial hepatectomy revealed abnormal hypertriploid karyotypes, with a suggestion of clonal evolution: 62-92 < 3n >,XX, -Y, +3, +6, +6, +7, +7, +8, +10, +13, +15, +16, +20, -21, -22, +mar1 x 2, +mar[cp6]/46,XY[8] and 78 < 3n >,XX, -Y,der(1)t(1;1)(p36.1;q21), +4, +6, +6, +7, +7,i(8)(q10), +10, +15, +20, -21, -22, +mar1 x 2, +mar2[3]/46, XY[17], respectively. Karyotypes of this variant of HCC have not been reported previously. The cytogenetics of HCC are reviewed.

Rhabdoid tumor of the kidney with primitive neuroectodermal tumor of the central nervous system: associated tumors with different histologic, cytogenetic, and molecular findings

Rhabdoid tumor of the kidney (RTK) is associated with tumors of the central nervous system (CNS) in approximately 15% of cases. We describe the clinical features, histologic and cytogenetic findings, and molecular analysis of renal and CNS tumors from the same patient. The histology of the renal tumor was consistent with rhabdoid tumor. The CNS tumor was a primitive neuroectodermal tumor (PNET). The karyotype of the RTK was normal male. The PNET of the brain demonstrated monosomy 22 as the only cytogenetic abnormality, similar to reported cases of malignant rhabdoid tumor of the brain, but dissimilar to nonrandom cytogenetic findings in other CNS PNETs. Molecular cytogenetic and DNA marker studies confirmed loss of chromosome 22 in this patient's brain tumor. DNA allelotyping showed retention of both parental chromosome 22 alleles in the RTK and loss of the maternal allele in the PNET. Evaluation of additional RTKs and brain tumors occurring in the same patient may provide insight into the origins and relationships of these enigmatic tumors.