Adenovirus-Mediated Calponin h1 Gene Therapy Directed against Peritoneal Dissemination of Ovarian Cancer: Bifunctional Therapeutic Effects on Peritoneal Cell Layer and Cancer Cells

Abstract

Purpose: Calponin h1 (CNh1), one of the family of actin-binding proteins, stabilizes the filaments of actin and modulates various cellular biological phenotypes. Recent studies revealed the close correlation between the invasive tumor spread and the reduced expression of CNh1 and α-smooth muscle actin in the surrounding stromal cells. The purpose of this study is to evaluate the efficacy of i.p. CNh1 gene therapy against peritoneal dissemination of ovarian cancer. Experimental Design: We used an adenoviral vector to induce the CNh1 gene into peritoneal cells and ovarian cancer cells as a means of enhancing or inducing the expression of α-smooth muscle actin as well as CNh1. The efficacy of gene transfer was examined by in vitro cell culture and in vivo animal experiments. Results: The formation of longer and thicker actin fibers was observed in each transfected cell line, and the localization of these fibers coincided with that of externally transducted CNh1. With respect to changes in cell behavior, the CNh1-transfected peritoneal cells acquired an ability to resist ovarian cancer-induced shrinkage in cell shape; thus, cancer cell invasion through the monolayer of peritoneal cells was inhibited. In addition, CNh1-transfected ovarian cancer cells showed suppressed anchorage-independent growth and invasiveness, the latter of which accompanied impaired cell motility. The concomitant CNh1 transfection into both peritoneal cells and ovarian cancer cells produced an additive inhibitory effect with respect to cancer cell invasion through the peritoneal cell monolayer. By in vivo experiments designed to treat nude mice that had been i.p. inoculated with ovarian cancer cells, we found that the i.p. injected CNh1 adenovirus successfully blocked cancer-induced morphologic changes in peritoneal cell surface and significantly prolonged the survival time of tumor-bearing mice. Moreover, CNh1 adenovirus could successfully enhance the therapeutic effect of an anticancer drug without increase in side effects. Conclusions: Thus, CNh1 gene therapy against peritoneal dissemination of ovarian cancer is bifunctionally effective (i.e., through inhibitory effects on the infected peritoneal cell layers that suppress cancer invasion and through direct antitumor effects against invasion and growth properties of cancer cells).

Changes in Gene Expression and Cellular Architecture in an Ovarian Cancer Progression Model

“…This hypothesis is supported by recent observations demonstrating that interference with actin dynamics is more effective than microtubule disturbance in inhibiting human ovarian cancer cell motility [43], and stabilization of the actin cytoskeleton can be achieved by re-introduction of actin-binding proteins such as calponin [44]. Interestingly, calponin re-expression in ovarian cancer cells also significantly reduced peritoneal dissemination [45].…”

Calponin in Non-Muscle Cells

“…Zinc deficiency was found to correlate with h1-calponin degradation in precancerous esophageal tissues [103]. Adenovirus-mediated h1-calponin gene therapy against peritoneal dissemination of ovarian cancer showed bifunctional therapeutic effects on stabilizing peritoneal cytoskeleton to resist cancer cell invasion and on inhibiting tumor cell invasion and growth [104].…”

Cell–cell and cell–matrix dynamics in intraperitoneal cancer metastasis

“…In addition, minimizing the amount of exposed peritoneal ECM by preventing mesothelial retraction is an intriguing avenue to further reduce peritoneal metastasis [168, 169]. If cancer cell–ECM interactions could be limited by minimizing mesothelial cell retraction, the approach of blocking mesothelial–cancer cell interactions would become more relevant.…”