Tumor infiltrating macrophages play an important role in tumor progression. Macrophage chemoattractant protein-1 (MCP-1) is one of the major chemokines responsible for inducing macrophage migration. Our objective was to investigate chemotherapy-induced modulation of MCP-1 in ovarian cancer by investigating macrophage infiltration, tumor vascularity, and MCP-1 expression after chemotherapy exposure.
MA-148 ovarian cancer cells were treated with paclitaxel (43 pg/mL) and carboplatin (5 microg/mL) alone or in combination. Reverse transcription-polymerase chain reaction determined MCP-1 transcript levels and enzyme-linked immunosorbent assay evaluated MCP-1 protein production at multiple time points. The effect of kinase inhibitors on MCP-1 expression was investigated. In vivo MCP-1 production was examined in tumor-bearing mice and immunohistochemistry with fluorescein isothiocyanate conjugated anti-mouse F4/80 antibody, phycoerythrin-anti-CD31, and terminal deoxynucleotide transferase dUTP nick-end labeling assay were performed.
Macrophage chemoattractant protein-1 transcript levels were up-regulated in MA-148 after treatment with paclitaxel and carboplatin individually and in combination. The greatest elevation was seen with combination therapy: 2.5-fold increase in the MCP-1 protein levels from baseline (P = 0.011) with the mitogen-activated protein kinase and janus kinases/signal transducers and activators of transcription pathways appearing to be involved in the regulation of MCP-1 production. In vivo mouse studies confirmed increased MCP-1 production after chemotherapy; however, there was no significant difference in macrophage, apoptosis, or vessel density.
Macrophage chemoattractant protein-1 is up-regulated in ovarian cancer after chemotherapy in vitro and in vivo. Whether MCP-1 production is increased because of a stress-induced response or a scavenger response promoting macrophage infiltration remains unknown. Chemotherapy induction of MCP-1 in ovarian cancer suggests this chemokine plays an important role in the immune response occurring after chemotherapy exposure.
International Journal of Gynecological Cancer 08/2010; 20(6):918-25. DOI:10.1111/IGC.0b013e3181e5c442 · 1.95 Impact Factor
Selective silencing of HPV oncogenes using short interfering RNA (siRNA) blocks E6/E7 expression and restores normal p53 and Rb function. Our objective was to determine if siRNA targeting E6/E7 would inhibit the growth of established tumors in a mouse model of cervical cancer.
In vitro studies were performed using unique siRNA sequences to confirm their ability to target and reduce E6/E7 mRNA and restore functioning p53. Next, siRNA targeting lamin was injected daily for three days into tumors established from HPV 16 positive CaSki human cervical cancer cells. Immunohistochemistry and branched DNA gene quantification were used to determine distribution and duration of activity of these siRNA. For our therapeutic studies tumors were directly injected with siRNA targeting E6/E7, non-targeting control siRNA, or saline. In preliminary experiments injections were daily or every three days for a total of three doses. A second therapeutic experiment utilized every three day dosing for 35 days. Tumor volume, growth curves and E7 mRNA levels were assessed.
The two most active siRNA sequences resulted in a 67% and 71% reduction in E6/E7 mRNA. Fluorescent lamin siRNA was visualized up to 120 h after the initial tumor injection and was evenly distributed throughout the tumors. IHC showed lamin expression to be inhibited by 68% and 75% when compared to controls at 54 and 120 h respectively. In our preliminary therapeutic intervention experiments there was no significant difference in tumor growth between the treatment groups when mice were treated with three daily injections (p=0.41). However, when treated every third day for three injections final tumor volume was less in animals injected with siRNA sequences A (78% reduction; p<0.0001) and G (60% reduction; p=0.005) compared to saline injection. Tumors showed a corresponding decrease in E6/E7 mRNA. Extended treatment with siRNA completely or nearly eradicated tumors in 70% of the animals.
Therapeutic siRNA targeting E6/E7 significantly inhibits tumor growth in this mouse model of cervical cancer. Further investigation is needed to determine optimal dosing and route of delivery.
Gynecologic Oncology 09/2008; 111(2):356-64. DOI:10.1016/j.ygyno.2008.06.033 · 3.69 Impact Factor
To determine the impact of thalidomide and angiostatin on tumor growth, angiogenesis, and apoptosis in a xenograft model of cervical cancer.
Human umbilical endothelial cells were treated with angiostatin or thalidomide and bFGF-induced proliferation was assessed with the MTT assay. Human cervical cancer cells (CaSki and SiHa) were injected into the flanks of nude mice. After tumors developed, mice were treated with angiostatin 20 mg/kg/day or thalidomide 200 mg/kg/day for 30 days. Fractional tumor growth was determined and immunohistochemical analysis of tumors was used to determine degree of angiogenesis. TUNEL assay was used to assess apoptosis.
Angiostatin inhibited endothelial cell proliferation by 50-60%. Thalidomide had no direct effect on endothelial cells. Angiostatin and thalidomide both inhibited tumor growth by about 55%. We found no additive or synergistic effect when the two agents were combined. Both agents inhibited angiogenesis and induced apoptosis when compared to tumors from control animals.
Angiostatin and thalidomide inhibit tumor growth, angiogenesis, and induce apoptosis in this xenograft model of cervical cancer.
Gynecologic Oncology 09/2005; 98(2):203-10. DOI:10.1016/j.ygyno.2005.04.023 · 3.69 Impact Factor