Type I collagen gene suppresses tumor growth and invasion of malignant human glioma cells

<p>Abstract</p> <p>Background</p> <p>Invasion is a hallmark of a malignant tumor, such as a glioma, and the progression is followed by the interaction of tumor cells with an extracellular matrix (ECM). This study examined the role of type I collagen in the invasion of the malignant human glioma cell line T98G by the introduction of the human collagen type I α1 (HCOL1A1) gene.</p> <p>Results</p> <p>The cells overexpressing HCOL1A1 were in a cluster, whereas the control cells were scattered. Overexpression of HCOL1A1 significantly suppressed the motility and invasion of the tumor cells. The glioma cell growth was markedly inhibited <it>in vitro </it>and <it>in vivo </it>by the overexpression of HCOL1A1; in particular, tumorigenicity completely regressed in nude mice. Furthermore, the HCOL1A1 gene induced apoptosis in glioma cells.</p> <p>Conclusion</p> <p>These results indicate that HCOL1A1 have a suppressive biological function in glioma progression and that the introduction of HCOL1A1 provides the basis of a novel therapeutic approach for the treatment of malignant human glioma.</p

Screening of potential molecular targets for colorectal cancer therapy

Kimi Honma1, Ichiro Takemasa2, Ryo Matoba3, Yusuke Yamamoto1, Fumitaka Takeshita1, Masaki Mori2, Morito Monden2, Kenichi Matsubara3, Takahiro Ochiya11Section for Studies on Metastasis, National Cancer Center Research Institute, Tokyo, Japan; 2Graduate School of Medicine, Osaka University, Osaka, Japan; 3DNA Chip Research Inc., Yokohama, JapanAbstract: Colorectal cancer is a leading cause of cancer death worldwide. To identify molecular targets for colorectal cancer therapy, we tested small interfering RNAs (siRNAs) against 97 genes whose expression was elevated in human colorectal cancer tissues for the ability to promote apoptosis of human colorectal cancer cells (HT-29 cells). The results indicate that the downregulation of PSMA7 (proteasome subunit, &amp;alpha;-type, 7) and RAN (ras-related nuclear protein) most efficiently induced apoptosis of HT-29 cells. PSMA7 and RAN were highly expressed in colorectal cancer cell lines compared with normal colon tissues. Furthermore, PSMA7 and RAN were overexpressed in not only colon tumor tissues but also the other tumor tissues. Moreover, in vivo delivery of PSMA7 siRNA and RAN siRNA markedly induced apoptosis in HT-29 xenograft tumors in mice. Thus, silencing of PSMA7 and RAN induces cancer cells to undergo apoptosis, and PSMA7 and RAN might be promising new molecular targets for drug and RNA interference-based therapeutics against colorectal cancer.Keywords: colorectal cancer, molecular target, RNAi, PSMA7, RA

Suppression of T98G cell motility and invasion by overexpression of HCOL1A1

<p><b>Copyright information:</b></p><p>Taken from "Type I collagen gene suppresses tumor growth and invasion of malignant human glioma cells"</p><p>http://www.cancerci.com/content/7/1/12</p><p>Cancer Cell International 2007;7():12-12.</p><p>Published online 20 Jun 2007</p><p>PMCID:PMC1925056.</p><p></p> Mock cells (Mock) and HCOL1A1-transfected cells (HCOL1A1-I and HCOL1A1-II) were added to a transwell chamber and the cell motility was evaluated. (a) The migrated cells were stained and photographed under the microscope at × 100 magnification. (b) The number of migrated cells was counted, and the results represent a percentage of Mock cells. Each value is a mean ± SD (n = 4). *, < 0.001, when tested against the Mock. Mock cells (Mock) and HCOL1A1-transfected cells (HCOL1A1-I and HCOL1A1-II) were added to a transwell chamber coated with Matrigel and the cell invasion was evaluated. (c) The invaded cells were stained and photographed under a microscope at × 100 magnification. (d) The number of invaded cells was counted, and the results are expressed as a percentage of Mock cells. Each value is a mean ± SD (n = 4). *, < 0.001, **, < 0.01 when tested against the Mock. The cell invasion into an invasion model was evaluated using reconstituted basement membrane wafers. (e) Mock cells (Mock) and HCOL1A1-transfected cells (HCOL1A1-I) were plated onto Matrigel wafers. On days 3 and 7 after plating, Matrigel wafers and adherent cells were fixed, and sections were stained with hematoxylin and eosin. Magnification, × 200

Atelocollagen-mediated synthetic small interfering RNA delivery for effective gene silencing in vitro and in vivo

Silencing gene expression by siRNAs is rapidly becoming a powerful tool for the genetic analysis of mammalian cells. However, the rapid degradation of siRNA and the limited duration of its action call for an efficient delivery technology. Accordingly, we describe here that Atelocollagen complexed with siRNA is resistant to nucleases and is efficiently transduced into cells, thereby allowing long-term gene silencing. Site-specific in vivo administration of an anti-luciferase siRNA/Atelocollagen complex reduced luciferase expression in a xenografted tumor. Furthermore, Atelocollagen-mediated transfer of siRNA in vivo showed efficient inhibition of tumor growth in an orthotopic xenograft model of a human non-seminomatous germ cell tumor. Thus, for clinical applications of siRNA, an Atelocollagen-based non-viral delivery method could be a reliable approach to achieve maximal function of siRNA in vivo