Intraperitoneal administration of a small interfering RNA targeting nuclear factor-kappa B with paclitaxel successfully prolongs the survival of xenograft model mice with peritoneal metastasis of gastric cancer.
ABSTRACT Activation of nuclear factor-kappa B (NF-kappaB) has been detected in various malignant tumors, including gastric carcinoma, and is associated with tumor growth, metastasis, resistance to chemotherapeutic agents and poor prognosis. Therefore, NF-kappaB is a potential target for antitumor therapy. In this study, we used a small interfering RNA (siRNA) to knockdown NF-kappaB p65 expression and determined whether intraperitoneal administration of NF-kappaB p65 siRNA and paclitaxel was effective for treating peritoneal metastasis of gastric cancer. Western blot analysis revealed that NF-kappaB p65 expression was diminished by NF-kappaB p65 siRNA. Apoptotic cells were increased after transfection of NF-kappaB p65 siRNA compared with control siRNA in the treatment with paclitaxel. In a murine xenograft model, abundant fluorescence was observed on the surface of intraperitoneal nodules of gastric cancer after siRNA administration. Moreover, intraperitoneal administration of NF-kappaB p65 siRNA reduced NF-kappaB expression in intraperitoneal nodules of gastric cancer. Finally, mice treated by intraperitoneal administration of NF-kappaB p65 siRNA and paclitaxel survived for a significantly longer time than mice treated by intraperitoneal administration of paclitaxel alone (p = 0.0002). Taken together, the present results demonstrate that intraperitoneal administration of NF-kappaB p65 siRNA and paclitaxel inhibited cancer growth in mice with peritoneal metastasis of gastric cancer. Therefore, intraperitoneal administration of NF-kappaB p65 siRNA and paclitaxel may provide a breakthrough in the treatment of peritoneal metastasis of gastric cancer.
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ABSTRACT: Inducible activation of nuclear factor-kappaB (NF-kappaB) inhibits the apoptotic response to chemotherapy and irradiation. Activation of NF-kappaB via phosphorylation of an inhibitor protein IkappaB leads to degradation of IkappaB through the ubiquitin-proteasome pathway. We hypothesized that inactivation of proteasome function will inhibit inducible NF-kappaB activation, thereby increasing levels of apoptosis in response to chemotherapy and enhancing antitumor effects. To assess the effects of proteasome inhibition on chemotherapy response, human colorectal cancer cells were pretreated with the dipeptide boronic acid analogue PS-341 (1 microM) prior to exposure to SN-38, the active metabolite of the topoisomerase I inhibitor, CPT-11. Inducible activation of NF-kappaB and growth response were evaluated in vitro and in vivo. Effects on p53, p21, p27 and apoptosis were determined. Pretreatment with PS-341 inhibited activation of NF-kappaB induced by SN-38 and resulted in a significantly higher level of growth inhibition (64-75%) compared with treatment with PS-341 alone (20-30%) or SN-38 alone (24-47%; P < 0.002). Combination therapy resulted in a 94% decrease in tumor size compared with the control group and significantly improved tumoricidal response to treatment compared with all treatment groups (P = 0.02). The level of apoptosis was 80-90% in the treatment group that received combination treatment compared with treatment with single agent alone (10%). Proteasome inhibition blocks chemotherapy-induced NF-kappaB activation, leading to a dramatic augmentation of chemosensitivity and enhanced apoptosis. Combining proteasome inhibition with chemotherapy has significant potential to overcome the high incidence of chemotherapy resistance. Clinical studies are currently in development to evaluate the role of proteasome inhibition as an important adjuvant to systemic chemotherapy.Cancer Research 05/2001; 61(9):3535-40. · 8.65 Impact Factor
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ABSTRACT: Respiratory syncytial virus (RSV) and parainfluenza virus (PIV) are two respiratory pathogens of paramount medical significance that exert high mortality. At present, there is no reliable vaccine or antiviral drug against either virus. Using an RNA interference (RNAi) approach, we show that individual as well as joint infection by RSV and PIV can be specifically prevented and inhibited by short interfering RNAs (siRNAs), instilled intranasally in the mouse, with or without transfection reagents. The degree of protection matched the antiviral activity of the siRNA in cell culture, allowing an avenue for quick screening of an efficacious siRNA. When targeting both viruses in a joint infection, excess of one siRNA moderated the inhibitory effect of the other, suggesting competition for the RNAi machinery. Our results suggest that, if properly designed, low dosages of inhaled siRNA might offer a fast, potent and easily administrable antiviral regimen against respiratory viral diseases in humans.Nature Medicine 02/2005; 11(1):50-5. · 22.86 Impact Factor
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ABSTRACT: Tumor necrosis factor alpha (TNF-alpha) binding to the TNF receptor (TNFR) potentially initiates apoptosis and activates the transcription factor nuclear factor kappa B (NF-kappaB), which suppresses apoptosis by an unknown mechanism. The activation of NF-kappaB was found to block the activation of caspase-8. TRAF1 (TNFR-associated factor 1), TRAF2, and the inhibitor-of-apoptosis (IAP) proteins c-IAP1 and c-IAP2 were identified as gene targets of NF-kappaB transcriptional activity. In cells in which NF-kappaB was inactive, all of these proteins were required to fully suppress TNF-induced apoptosis, whereas c-IAP1 and c-IAP2 were sufficient to suppress etoposide-induced apoptosis. Thus, NF-kappaB activates a group of gene products that function cooperatively at the earliest checkpoint to suppress TNF-alpha-mediated apoptosis and that function more distally to suppress genotoxic agent-mediated apoptosis.Science 10/1998; 281(5383):1680-3. · 31.03 Impact Factor