Interleukin 8 expression regulates tumorigenicity and metastases in androgen-independent prostate cancer.

Interleukin 8 (IL-8) is mitogenic and chemotactic for endothelial cells. Within a neoplasm, IL-8 is secreted by inflammatory and neoplastic cells. The highly metastatic PC-3M-LN4 cell line overexpresses IL-8 relative to the poorly metastatic PC-3P cell line. We evaluated whether IL-8 expression by human prostate cancer growing within the prostate of athymic nude mice regulates tumor angiogenesis, growth, and metastasis. PC-3P cells were transfected with the full-length sense IL-8 cDNA, whereas PC-3M-LN4 cells were transfected with the full-sequence antisense IL-8 cDNA. Control cells were transfected with the neomycin resistance gene (Neo). In vitro, sense-transfected PC-3P cells overexpressed IL-8-specific mRNA and protein, which resulted in up-regulation of matrix metalloproteinase 9 (MMP-9) mRNA, and collagenase activity, resulting in increased invasion through Matrigel. After antisense transfection of the PC-3M-LN4 cells, IL-8 and MMP-9 expression, collagenase activity, and invasion were markedly reduced relative to controls. After orthotopic implantation, the sense-transfected PC-3P cells were highly tumorigenic and metastatic, with significantly increased neovascularity and IL-8 expression compared with either PC-3P cells or controls. Antisense transfection significantly reduced the expression of IL-8 and MMP-9 and tumor-induced neovascularity, resulting in inhibition of tumorigenicity and metastasis. These results demonstrate that IL-8 expression regulates angiogenesis in prostate cancer, in part by induction of MMP-9 expression, and subsequently regulates the growth and metastasis of human prostate cancer.

Interleukin 8 expression regulates tumorigenicity and metastasis in human bladder cancer.

Interleukin 8 (IL-8) is mitogenic and chemotactic for endothelial cells. Within a neoplasm, IL-8 is secreted by inflammatory and neoplastic cells. The highly tumorigenic and highly metastatic human transitional cell carcinoma (TCC) cell line 253J B-V overexpresses IL-8 relative to the nontumorigenic and nometastatic 253J-P cell line. To determine whether IL-8 expression regulates tumorigenicity and metastasis in human TCC, 253J B-V cells were transfected with the full-sequence antisense (AS) cDNA for IL-8, whereas 253J-P cells were transfected with the full-length IL-8 cDNA, and control cells for each were transfected with the neomycin resistance (Neo) gene. In vitro, sense-transfected 253J-P cells overexpressed IL-8-specific mRNA and protein, whereas both of these were markedly reduced in AS-IL-8-transfected 253J B-V cells relative to controls. Moreover, sense-transfected cells showed up-regulation in matrix metalloproteinase type 9 mRNA, collagenase activity, and increased invasiveness through Matrigel-coated filters, whereas these measures were lower in AS-transfected cells relative to controls. After implantation into the bladders of athymic nude mice, the sense-transfected 253J-P cells acquired increased tumorigenicity and metastasis, whereas the AS-transfected cells significantly inhibited tumorigenicity and metastases in the 253J B-V cell lines. This effect was accompanied by reduced IL-8 expression and microvessel density. These studies demonstrate that IL-8 expression enhances angiogenic activity through the induction of matrix metalloproteinase type 9 and subsequently regulates the tumorigenesis and production of spontaneous metastases of human TCC.

Anti-epidermal growth factor receptor antibody C225 inhibits angiogenesis in human transitional cell carcinoma growing orthotopically in nude mice.

Epidermal growth factor receptor (EGFR) regulates the growth and progression of human transitional cell carcinoma (TCC) of the bladder. We have shown that therapy targeting EGFR inhibited the growth of human TCC established orthotopically in nude mice. The purpose of this study was to evaluate whether EGFR-directed therapy affects angiogenesis associated with the growth and metastasis of human TCC. We determined the cytostatic effect and the effect on production of angiogenic factors after in vitro treatment of the human TCC cell line 253J B-V with MAb C225, a chimerized monoclonal anti-EGFR antibody. The 253J B-V cells were implanted orthotopically into athymic nude mice, and established tumors (4 weeks) were treated with i.p. MAb C225. Expression of the angiogenic factors vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), and basic fibroblast growth factor (bFGF) was evaluated by immunohistochemistry and in situ mRNA hybridization analyses and correlated with microvessel density evaluated after immunohistochemical staining with anti-CD31. In vitro treatment with MAb C225 inhibited mRNA and protein production of VEGF, IL-8, and bFGF by 253J B-V cells in a dose-dependent manner. MAb C225 therapy of nude mice with established TCCs growing orthotopically resulted in inhibition of growth and metastasis compared with controls (P <0.0005). VEGF, IL-8, and bFGF expression was significantly lower in treated tumors than in controls. The down-regulation of these angiogenic factors preceded the involution of blood vessels. These studies indicate that therapy with anti-EGFR MAb C225 has a significant antitumor effect mediated, in part, by inhibition of angiogenesis.

Inhibition of basic fibroblast growth factor expression, angiogenesis, and growth of human bladder carcinoma in mice by systemic interferon-alpha administration.

The purpose of these studies was to determine whether systemic administration of IFN-alpha can inhibit the expression of basic fibroblast growth factor (bFGF) in human transitional cell carcinoma, reduce its angiogenesis, and thus inhibit its growth in the bladder wall of nude mice. In vitro incubation of the highly metastatic 253J B-V cells and the IFN-alpha-resistant 253J B-V IFNR cells with noncytostatic concentrations of IFN-alpha down-regulated the steady-state mRNA transcripts and protein production of bFGF. IFN-alpha-insensitive and IFN-alpha-resistant cells were implanted in the bladder wall of nude mice. Systemic administration of IFN-alpha decreased the in vivo expression of bFGF, decreased blood vessel density in the tumors, and inhibited tumor growth of both IFN-alpha-insensitive and IFN-alpha-resistant cells. These data suggest that in addition to its well-documented antiproliferative effects, IFN-alpha can inhibit the growth of human bladder cancer cells by inhibition of angiogenesis.

Therapy of human transitional cell carcinoma of the bladder by oral administration of the epidermal growth factor receptor protein tyrosine kinase inhibitor 4,5-dianilinophthalimide.

Epidermal growth factor receptor (EGF-R), a transmembrane glycoprotein that mediates the mitogenic response of cells to epidermal growth factor, is highly expressed on malignant human bladder cancer cells. The 4,5-dianilinophthalimides represent a novel class of inhibitors of the EGF-R family of tyrosine kinase with selectivity at the enzymatic and cellular levels. Two compounds of this class, CGP 54211 and CGP 53353, inhibited tyrosine kinase activity of the EGF-R in five different human transitional cell carcinoma lines. The compounds also produced cytostasis in vitro. Highly metastatic human 253J B-V cells were implanted in the bladder wall of nude mice. The daily oral administration of CGP 54211 inhibited the level of EGF-R phosphorylation in this tumor; necrosis and inhibition of tumor growth paralleled this inhibition.

Intravesical liposomal muramyl tripeptide phosphatidylethanolamine treatment of human bladder carcinoma growing in nude mice.

The present study evaluated the in vivo activity of synthetic lipophilic muramyl tripeptide phosphatidylethanolamine (MTP-PE) when encapsulated into liposomes (phosphatidylcholine-phosphatidylserine, 7:3 molar ratio) and administered intravesically to athymic nude mice with human transitional cell carcinoma 253J-V cells growing in their bladder. Intravesical liposome-MTP-PE was effective in eradicating the human tumors implanted orthotopically in nude mice. Following therapy, activated macrophages were found in the bladders of liposome-MTP-PE-treated mice but not in control mice. In vitro activation of murine macrophages with liposome-MTP-PE increased their cytotoxicity against the 253J-V cell line used in these experiments. This effect was enhanced by cotreatment with interferon-gamma (IFN-gamma). Furthermore, cotreatment of macrophages with both liposome-MTP-PE and IFN-gamma resulted in the secretion of both tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6). Liposome-encapsulated MTP-PE shows promise as an effective therapeutic agent for bladder carcinoma.