Aneusomy is an early genetic event and a characteristic feature of many solid tumors. It is often associated with poor prognosis in cancer patients. The involvement of PAX8-PPARγ rearrangement in tumorigenesis of follicular thyroid lesions has been widely assessed. However, there were few reports on aneusomy of the PPARγ gene at the 3p25 locus in follicular thyroid lesions. It remains undetermined whether these abnormalities can be translated into improved diagnosis, classification, or outcome prediction. Herein, we report three cases of follicular thyroid neoplasms [two follicular thyroid carcinomas (FTCs) and one Hurthle cell adenoma (HCA)] with 3p25 aneusomy detected by fluorescence in situ hybridization (FISH). 3p25 trisomy was observed in one FTC and one HCA while 3p25 tetrasomy was observed in one FTC. Furthermore, all three lesions did not show overexpression of PPARγ protein. Hurthle cell neoplasms (HCN) are distinct clinically and histologically from other follicular thyroid neoplasms (FTN). However, the presence of the aneusomy in HCA and FTC indicates that there could be a biological continuum between the two and chromosomal gains might play an important role in the pathogenesis of these two types of neoplasms. Despite their differences, HCN and FTN may share the same early genetic event in tumour development.
The identification of chromosomal aberrations in prostate cancer has been widely studied with several known oncogenes and tumor suppressor genes have successfully been discovered. The most frequent aberrations detected in western population were losses in chromosome 5q, 6q, 8p, 13q, 16q, 17p, 18q and gains of 7p/q and 8q. The purpose of this study was to determine the chromosomal aberrations among Malaysian men of Southeast Asia population and discover those potential genes within that chromosomal aberrant region. Thirty-six formalin-fixed paraffin embedded specimens consist of eight organ-confined prostate cancer cases, five with capsular invasion, 14 showed metastasis and nine cases had no tumor stage recorded, were analyzed by array CGH technique. Chromosomal losses were frequently detected at 4q, 6q, 8p, 13q, 18q while gains at 7q, 11q, 12p, 16q and 17q. Gain of 16q24.3 was statistically significant with tumor size. Gains of 6q25.1 and Xq12 as well as losses of 3p13-p1.2 and 13q33.1-q33.3 were significantly correlated with Gleason grade whereas 12p13.31 gain was associated with bone metastasis. Several potential genes have also been found within that aberrant region which is myopodin (4q26-q27), ROBO1 (3p13-p11.2), ERCC5 (13q33.1-q33.3) and CD9 (12p13.31), suggesting that these genes may play a role in prostate cancer progression. The chromosomal aberrations identified by array CGH analysis could provide important clues to discover potential genes associated with prostate tumorigenesis of Malaysian men.
Turner syndrome is one of the most common chromosomal abnormalities affecting newborn females. More than half of patients with Turner syndrome have a 45X karyotype The rest of the patients may have structurally abnormal sex chromosomes or are mosaics with normal or abnormal sex chromosomes. Mosaicism with a second X sex chromosome is not usually of clinical significance. However, Turner syndrome patients having a second Y chromosome or Y chromosomal material are at risk of developing gonadoblastoma later in life. The aim of this study is to compare the results of conventional (karyotyping) and molecular cytogenetics (FISH), and discuss the advantages and limitations in the diagnosis of Turner syndrome. We also aim to compare the degree of mosaicism identified using conventional cytogenetics and FISH techniques. Conventional cytogenetics and FISH analyses were performed on eight peripheral blood samples of patients with Turner syndrome collected between 2004 and 2006. From this study, two out of eight patients with Turner syndrome were found to have the sex determining region on the Y chromosome (SRY) gene by FISH analysis. Our results showed that the rate of detection of mosaic cases in Turner syndrome was also increased to 88% after using the FISH technique. We concluded that FISH is more superior to conventional cytogenetics in the detection of the Y chromosomal material. FISH is also a quick and cost effective method in diagnosing Turner syndrome and assessing the degree of mosaicism.
This is a study aimed to examine the distribution pattern of a specific minichromosome maintenance protein 2 (MCM2) in benign and malignant breast tissue. We also aim to correlate the frequency of expression of MCM2 with the degree of tumor differentiation. We used immunohistochemistry to examine the distribution and expression pattern of MCM2 on formalin-fixed paraffin-embedded tissue sections of benign (n = 30) and malignant breast tissue (n = 70) (IDC 56, DCIS 4, ILC 2, nonductal 4, mixed type 4). We quantified MCM2 expression by calculating a labeling index, which represents the percentage of epithelial nuclei that stained positively. Immunoreactivity was heterogenous in all the 70 malignant cases examined. Epithelial cells in cycle are most frequent at the tumor periphery. Labeling index of MCM2 was greatest in grade 3 (poorly differentiated) and lowest in grade 1 tumors (well differentiated). Minichromosome maintenance protein 2 expression in breast cancer showed a positive association with histologic grade (P < .05). In all the benign breast tissue examined, no proliferating compartments could be characterized. Minichromosome maintenance protein 2 is a useful proliferative marker of breast carcinoma. The frequency of expression of MCM2 showed an inverse correlation with the degree of tumor differentiation.
At the present time, the differentiation between follicular thyroid carcinoma (FTC) and adenoma can be made only postoperatively and is based on the presence of capsular or vascular invasion. The ability to differentiate preoperatively between the malignant and benign forms of follicular thyroid tumors assumes greater importance in any clinical setting. The PAX8-PPARG translocation has been reported to occur in the majority of FTC. In this study, a group of 60 follicular thyroid neoplasms [18 FTC, 1 Hurthle cell carcinoma (HCC), 24 follicular thyroid adenomas (FTA), 5 Hurthle cell adenomas (HCA), and 12 follicular variants of papillary thyroid carcinomas (FV-PTC)] were analyzed to determine the prevalence of the PAX8-PPARG translocation by fluorescence in situ hybridization. The PAX8-PPARG translocation was detected in 2/18 FTC (11.1%). In addition, 2/18 (11.1%) FTC and 1/5 (20%) HCA showed 3p25 aneusomy only. The frequency of the translocation detected in the study was lower compared to the earlier studies conducted in Western countries. This might be attributed to the ethnic background and geographic location. Detection of either the PAX8-PPARG translocation or the 3p25 aneusomy in FTC indicates that these are independent genetic events. It is hereby concluded that 3p25 aneusomy or PAX8-PPARG translocation may play an important role in the molecular pathogenesis of follicular thyroid tumors.