Metallothionein isoform 3 expression in the human prostate and cancer-derived cell lines.
BACKGROUND
Expression of metallothionein isoform 3 (MT-3) was initially reported to be confined to neural tissues. However, it was recently demonstrated that MT-3 is expressed in epithelial cells of the human kidney. This motivated the current examination of the expression of MT-3 in the human prostate.


METHODS
Immunohistochemistry (IHC) was used to localize the expression of MT-3, RT-PCR to determine the expression of MT-3 mRNA, and Western blot analysis to determine the level of MT-3 protein.


RESULTS
Selected epithelial and stromal cells of the normal human prostate were shown to have low levels of MT-3 expression. MT-3 was increased in prostatic intraepithelial neoplasia (PIN) lesions and further increased in a highly variable fashion in prostatic adenocarcinoma. In some adenocarcinomas, MT-3 expression exceeded that of nerve. Three cell culture models of prostate cancer were also shown to variably express MT-3. Restriction enzyme analysis confirmed the expression of MT-3 in the cells and tissues.


CONCLUSIONS
MT-3 is expressed in the normal human prostate, and expression is enhanced and highly variable in PIN lesions and primary prostate cancer cells. The variable nature of MT-3 expression was also noted in commonly utilized prostate cancer cell lines.
Garrett
S H
SH
Department of Pathology, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia 26506, USA.
Sens
M A
MA
Shukla
D
D
Nestor
S
S
Somji
S
S
Todd
J H
JH
Sens
D A
DA
D000595:Amino Acid Sequence; D004847:Epithelial Cells / Q000502:physiology; D015972:Gene Expression Regulation, Neoplastic; D006131:Growth Inhibitors / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D000090023:Metallothionein 3; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D011471:Prostatic Neoplasms / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D006131:Growth Inhibitors; D000090023:Metallothionein 3; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger