Metallothionein-1 and -2 expression in cadmium- or arsenic-derived human malignant urothelial cells and tumor heterotransplants and as a prognostic indicator in human bladder cancer.
The goal of this study was to determine if the expression of the metallothionein (MT)-1/2 proteins might serve as a biomarker for the development of bladder cancer. A retrospective analysis of MT-1/2 staining was performed on 343 tissue sections from patients referred for the diagnosis of bladder cancer. The specimens were subdivided into six categories: benign, dysplastic, low-grade cancer, high-grade cancer with no evidence of invasion, high-grade cancer with evidence of invasion, and carcinoma in situ. There was no expression of MT-1/2 in benign lesions and low-grade cancers, a low incidence of expression in dysplastic lesions and high-grade cancers with no evidence of muscle invasion, and a significantly increased incidence of MT-1/2 in high-grade cancers that had invaded the underlying matrix. The expression of MT-1/2 varied in intensity from sample to sample and was focal in its expression. It was concluded from these findings that MT-1/2 may be a prognostic marker for cancers that are progressing to invade the underlying stroma of the bladder wall. The expression of MT-1/2 was also determined in a cell culture model of human urothelium that had been malignantly transformed by Cd2+ and As3+ and shown to be capable of tumor formation in nude mice. It was demonstrated that the expression of MT-1/2 in the tumor heterotransplants was similar to the pattern found in archival specimens of high-grade bladder cancers. The MT-1/2 staining in the heterotransplants was focal in pattern, varied in intensity, and highest in the less differentiated cells of the tumor. These findings indicate that the cell culture model may serve to help define the role of MT-1/2 expression in bladder cancer invasion.
Department of Pathology, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota 58202, USA.
Xu Dong
XD
Zhou
Donald A
DA
Sens
Mary Ann
MA
Sens
Venugopal B R K
VB
Namburi
Rajendra K
RK
Singh
Scott H
SH
Garrett
Seema
S
Somji
D000818:Animals; D001151:Arsenic / Q000633:toxicity; D014408:Biomarkers, Tumor; D002104:Cadmium / Q000633:toxicity; D002295:Carcinoma, Transitional Cell / Q000378:metabolism / Q000473:pathology; D002461:Cell Line, Transformed; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009368:Neoplasm Transplantation; D011379:Prognosis; D012333:RNA, Messenger / Q000378:metabolism; D001749:Urinary Bladder Neoplasms / Q000378:metabolism* / Q000473:pathology; D019459:Urothelium / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology
D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D002104:Cadmium; D008668:Metallothionein; D001151:Arsenic