D. Bello-deocampo et al., Laminin-1 and alpha 6 beta 1 integrin regulate acinar morphogenesis of normal and malignant human prostate epithelial cells, PROSTATE, 46(2), 2001, pp. 142-153
BACKGROUND. Cell-matrix interactions via integrin receptors are critical fo
r acinar morphogenesis. The non-tumorigenic, human prostate epithelial cell
line RWPE-1 was used in a three-dimensional (3D) cell culture model to ide
ntify the matrix protein and its integrin receptor required for acinar morp
hogenesis.
METHODS. 3D cultures, immunostaining, confocal microscopy, and Western blot
analysis were used to examine acinar formation on matrix proteins and to d
etermine integrin receptor expression.
RESULTS. RWPE-1 cells differentiate into acini of polarized cells with a di
stinct lumen in 3D Matrigel culture. In contrast, the malignant WPE1-NB26 p
rostate epithelial cells form solid cell masses. In 3D gels of laminin-1, t
ype IV collagen, or fibronectin, RWPE-1 cells form acini only in laminin-1.
Anti-laminin-1 antibody reduces acinar formation in a dose-dependent manne
r. Polarized RWPE-1 cells showed basal expression of alpha6 and beta1 integ
rin subunits. Blocking antibodies to alpha6 or beta1 reduced acinar formati
on to 9 and 6% of control, respectively. The beta1 integrin colocalized bet
a1 with focal adhesion kinase (FAK). Inhibition of extracellular signal-reg
ulated kinase kinase activity significantly reduced acinar formation to 38%
of control, suggesting that beta1 integrin-mediated signal transduction ma
y be regulated through a FAK pathway.
CONCLUSIONS. While basal expression of alpha6 beta1 integrin in RWPE-1 cell
s correlates with their ability to polarize and form acini, a decrease or l
oss of alpha6, and diffused beta1 expression in WPE1-NB26 cells correlates
with loss of acinar-forming ability. Results show that laminin-1 and a func
tional alpha6 beta1 integrin receptor are required fur acinar morphogenesis
. This novel 3D cell culture model is useful for elucidating regulation of
acinar morphogenesis and its loss during prostate carcinogenesis. Prostate
46:142-153, 2001. (C) 2001 Wiley-Liss, Inc.