Nuclear shape and the underlying nuclear structure, the nuclear matrix in
cancer cells. Since the NM composition is considered to maintain nuclear shape and architecture,
nuclear matrix proteins (NMPs) may be involved in transformation. Our laboratory has recently characterized a subset of NMPs that are associated with
prostate cancer development in the transgenic
adenocarcinoma of mouse prostate (TRAMP) model. One of the identified NMPs, E3E, has a similar molecular weight (22 kDa) with a
protein known as HMGI(Y). HMGI(Y) belongs to a group of non-
histone and
chromatin-associated
proteins, high-mobility-group (
HMG) proteins, and it has been shown to associate with the NM. HMGI(Y) has been reported to be elevated in different types of
cancer including
prostate cancer. In this study, we examined the expression of HMGI(Y)
protein in the NMP composition of the TRAMP model during the progression from normal to
neoplasia. The expression of HMGI(Y) in the NMP extracts of three prostatic epithelial cell lines derived from a 32-week TRAMP mouse: TRAMP-C1, TRAMP-C2, and TRAMP-C3 was also examined. Using both one-dimensional and high-resolution two-dimensional immunoblot analyses, we found that: (i) HMGI(Y) is a
nuclear matrix protein expressed as two
protein bands with MW of 22-24 kDa and (ii) HMGI(Y) expression is correlated with neoplastic and malignant properties in late stage TRAMP prostate
tumors. Overall, these findings support the evidence that HMGI(Y) can be utilized as a marker and prognostic tool for
prostate cancer.