Magdy Sayed Aly

Loss of Y chromosome in bilharzial bladder cancer.

Bilharzial bladder cancer is the most common malignant neoplasm in Egypt, also occurring with a high incidence in other regions of the Middle East and East Africa. In a previous study, using centromere probes specific for chromosomes 3, 4, 7-11, 16, and 17, we demonstrated that monosomy of chromosome 9 (48.4%), and numerical aberrations of chromosome 17 (19.4%) were the most common observed imbalances. The present study extends the establishment of the baseline cytogenetic profile of this type of malignancy. Interphase cytogenetics by fluorescence in situ hybridization with the use of a panel of centromere-associated DNA probes for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, X, and Y was performed on paraffin-embedded bladder specimens from 25 Egyptian patients affected with bilharzial bladder cancer. No numerical aberrations were detected in the 25 cases for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, and X. However, loss of chromosome Y was observed in 7 of the 17 male cases studied (41.2%). No significant correlation was observed between loss of the Y chromosome and any of the different clinicopathologic characteristics of these cases. These data suggest that loss of the Y chromosome is the second frequent event that can occur in bilharzial bladder cancer. A molecular genetic model of bilharzial bladder cancer is evolving.

Chromosomal Aberrations in Bilharzial Bladder Cancer as Detected by Fluorescence In Situ Hybridization

Cancer of the bladder is a frequent malignancy in Egypt and other developing countries in which bladder infection with the parasite Schistosoma haematobium is common. Several epidemiological, histopathological, and clinical characteristics of cancer of the Bilharzial bladder suggest that it is distinct from bladder cancer seen in other places in the world. No numerical aberrations of chromosomes that might be specific for Bilharzial bladder carcinoma have been established. In this study, we used fluorescence in situ hybridization (FISH) with centromere-specific probes for chromosomes 3, 4, 7, 8, 9, 10, 11, 16, and 17 to detect numerical aberrations of these chromosomes in frozen-stored samples of 31 Egyptian patients affected with Bilharzial carcinoma. Among 5 types of chromosomes examined, imbalance was observed; the most common imbalance was a loss of chromosome 9 (48.4%), with numerical aberration of chromosome 17 being the second most-frequent anomaly (19.4%). The presence of such anomalies, especially losses of chromosome 9, are associated with a younger age group of patients, as well as with a lower grade tumor and negative pelvic node involvement by the disease. Fluorescence in situ hybridization analysis thus proved to be a useful method for detecting numerical aberrations of individual chromosomes, with application to touch preparations of frozen-stored tissue having the advantage of exact sampling of cancer foci. This result also suggests that the mechanism of genetic progression of bladder cancer is independent of its etiology.

Chromosomal aberrations in early-stage bilharzial bladder cancer

Bilharzial bladder cancer is one of the most common types of malignancy in both men and women in several developing countries including Egypt. It has several unique clinical, epidemiological, and histological characteristics, suggesting that it is an entity distinct from bladder cancer seen in Western countries. Genetic alterations in bilharzial-related bladder cancer have been studied infrequently, especially in the advanced stages of disease, that is, T3 and T4 classifications. The objective of this study was to extend establishing the baseline cytogenetic profile of this type of malignancy to early T1 and T2 classifications. For this purpose, fluorescence in situ hybridization was applied to interphase nuclei of frozen-stored samples with biotinylated repetitive DNA probes specific for all chromosomes to detect numerical chromosome changes in 35 patients presenting with relatively early-stage pT1 and pT2 disease. Eleven cases had squamous cell carcinoma (SCC) and 24 had transitional cell carcinoma. Six of 24 transitional cell carcinomas had diploid chromosome counts with all the probes. Numerical chromosome aberrations were detected in 18 cases (75%). In 12 cases, a loss of chromosome 9 was observed. In three cases, an additional loss of chromosome 17 was detected. One case demonstrated a loss of chromosome 10, whereas another two cases showed a gain of chromosome 7, next to a loss of chromosome 9. Loss of chromosome Y was observed in nine of the 27 male cases studied (33.3%), in which only one case showed an abnormality whereas four cases were detected next to loss of chromosome 9, and one case showed gain of chromosome 7. Five cases showed loss of chromosome 19 whereas gain of chromosome 4 was detected in two cases. Two of 11 samples of SCC had normal diploid chromosome counts with all the probes used. In four of 11 cases (36.4%) underrepresentation of chromosome 9, compared with the other chromosomes, was detected. An additional loss of chromosome 17 and gain of chromosome 7, next to loss of chromosome 9, was detected in three cases. One case showed loss of chromosome 17 as the only numerical aberration. Loss of the Y chromosome was detected in three cases of which one case had gain of chromosome 7 and one case had loss of chromosome 19. No correlation was found between any of the clinicopathologic parameters examined in this study and the presence or absence of any numerical chromosomal aberrations except for the significant association between schistosomal history and loss of Y chromosome (P=0.007).

Specific numerical chromosomal aberrations induced by adriamycin

Fluorescence in situ hybridization with 7, 17, X, and Y chromosome‐specific DNA probe was used to investigate the ability of Adriamycin (AM) to induce aneuploidy in interphase human lymphocytes. The reliability of the probes was tested by hybridization to metaphases and interphase nuclei of untreated normal lymphocytes. Two signals were scored in over 87% of the analyzed nuclei with chromosome 7 and 17 probes, whereas one signal was recorded in over 86% of the nuclei with chromosomes X and Y. The same conditions and probe concentrations were used for hybridizing the four probes to interphase nuclei of AM‐treated and untreated lymphocytes, cultured from healthy individuals and cancer patients. AM was found to induce significant increases of trisomy 7 and 17 in lymphocytes cultured from healthy individuals and cancer patients, where the interphase nuclei showed three spots in over 70% and 72% of the cells, respectively. Only 6% of interphase nuclei of untreated cells cultured from healthy individuals and cancer patients showed three spots. No significant increase in X or Y aneuploidy was induced by exposure to AM. Environ. Mol. Mutagen. 33:161–166, 1999

Detection of HER-2/neu, c-myc amplification and p53 inactivation by FISH in Egyptian patients with breast cancer

Breast cancer is a leading cause of cancer-related deaths in women worldwide. The clinical course of this disease is highly variable and clinicians continuously search for prognostic parameters that can accurately predict prognosis, and indicate a suitable adjuvant therapy for each patient. Amplification of the two oncogenes HER-2/neu and c-myc and inactivation of the tumor suppressor gene p53 are frequently encountered in breast carcinomas. The purpose of this study was to use the fluorescence in situ hybridization (FISH) for the assessment of HER-2/neu and c-myc amplification and p53 inactivation and to relate these molecular markers with the commonly used clinical and pathological factors. The study was conducted on 34 tissue samples obtained from 33 females and 1 male with breast carcinomas and 17 samples obtained from 16 females and 1 male with benign breast lesions. Results revealed that the level of HER-2/neu, c-myc and p53 in the malignant group was significantly increased as compared to the benign group. On relating the level of the molecular markers to clinicopathological factors, p53 was significantly associated with increased patient’s age. The sensitivity of the investigated markers significantly increased with larger tumor size. Concerning tumor grade, HER-2/neu and p53 showed a significant increase in low-grade tumors whereas c-myc showed a highly significant increase in high-grade tumors. With regard to disease staging, HER-2/neu and c-myc were the only markers that showed significant increase at late stages of disease. p53 and HER-2/neu were significantly associated with positive lymph nodal status. A significant correlation was obtained between the levels of the three biomarkers to each other. Conclusively, the combination of HER-2/neu, c-myc and p53 can stratify patients into different risk groups.