Expression of c-myc protein is related to cell proliferation and expression of growth factor receptors in transitional cell bladder cancer.
Archival biopsy specimens from transitional cell bladder tumours (n = 185) were analysed immunohistochemically for expression of c-myc protein. The results were compared with histopathological and clinical parameters and survival. Forty-three per cent of the tumours were negative for c-myc protein and weak, moderate, or strong cytoplasmic expression was found in 34, 14, and 9 per cent of cases, respectively. Nuclear positivity for c-myc protein was detected in 35 per cent of tumours and nuclear positivity was related to overexpression of c-erb B-2 (P = 0.01) and a high proportion of nuclei were also positive for p53 oncoprotein (p < 0.05). Cytoplasmic expression of c-myc protein was related to histological grade (P = 0.005), papillary status (P = 0.007), the S-phase fraction (P = 0.008), the mitotic index (P = 0.021), overexpression of epidermal growth factor receptor (P = 0.045), and c-erb B-2 (P = 0.17). Expression of c-myc protein was not significantly related to the progression of tumours and it had no prognostic value in survival analysis. Independent predictors were the T-category (P < 0.001), papillary status. (P = 0.001), and S-phase fraction (P = 0.061). The results show that while c-myc gene product participates in growth regulation of human bladder cancer cells, it has no independent prognostic significance.
Lipponen
P K
PK
Department of Pathology, University of Kuopio, Finland.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000737:chemistry* / Q000473:pathology; D002455:Cell Division / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D066246:ErbB Receptors / Q000032:analysis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009363:Neoplasm Proteins / Q000032:analysis*; D011379:Prognosis; D016271:Proto-Oncogene Proteins c-myc / Q000032:analysis*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D001749:Urinary Bladder Neoplasms / Q000737:chemistry* / Q000473:pathology
D066246:ErbB Receptors; D009363:Neoplasm Proteins; D016271:Proto-Oncogene Proteins c-myc; D018719:Erb-b2 Receptor Tyrosine Kinases