Citation Details

Journal Article

Animals; Antineoplastic Agents; Benzocycloheptenes; Bioware; Breast Neoplasms; Carcinoma; Female; Hela Cells; Humans; K562 Cells; MDA-MB-231-D3H2LN cells; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Invasiveness; Neoplasm Metastasis; Oncogene Proteins; Protein kinase inhibitors; Proto-Oncogene Proteins; Receptor Protein-Tyrosine Kinases; Survival Analysis; Triazoles; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Accumulating evidence suggests important roles for the receptor tyrosine kinase Axl in cancer progression, invasion, metastasis, drug resistance, and patient mortality, highlighting Axl as an attractive target for therapeutic development. We have generated and characterized a potent and selective small-molecule inhibitor, R428, that blocks the catalytic and procancerous activities of Axl. R428 inhibits Axl with low nanomolar activity and blocked Axl-dependent events, including Akt phosphorylation, breast cancer cell invasion, and proinflammatory cytokine production. Pharmacologic investigations revealed favorable exposure after oral administration such that R428-treated tumors displayed a dose-dependent reduction in expression of the cytokine granulocyte macrophage colony-stimulating factor and the epithelial-mesenchymal transition transcriptional regulator Snail. In support of an earlier study, R428 inhibited angiogenesis in corneal micropocket and tumor models. R428 administration reduced metastatic burden and extended survival in MDA-MB-231 intracardiac and 4T1 orthotopic (median survival, >80 days compared with 52 days; P < 0.05) mouse models of breast cancer metastasis. Additionally, R428 synergized with cisplatin to enhance suppression of liver micrometastasis. Our results show that Axl signaling regulates breast cancer metastasis at multiple levels in tumor cells and tumor stromal cells and that selective Axl blockade confers therapeutic value in prolonging survival of animals bearing metastatic tumors.

Journal Article

Animals; Bioware; Cell Line, Tumor; Cell Proliferation; Female; Humans; Insulin; Lung Neoplasms; Lymphangiogenesis; MDA-MB-231-D3H1 cells; Mice; Neoplasm Metastasis; Neoplasms, Experimental; Neovascularization, Pathologic; Phosphorylation; Proto-Oncogene Proteins c-akt; Receptor, Insulin; RNA, Small Interfering; Vascular Endothelial Growth Factor A

Insulin receptor (IR) and the type I IGF receptor (IGF1R) are structurally and functionally related. The function of IGF1R in cancer has been well documented and anti-IGF1R strategies to treat cancer have shown initial positive results. However, the role of IR in tumor biology, independent of IGF1R, is less clear. To address this issue, short hairpin RNA (shRNA) was used to specifically downregulate IR in two cancer cell lines, LCC6 and T47D. Cells with reduced IR showed reduced insulin-stimulated Akt activation, without affecting IGF1R activation. Cells with reduced IR formed fewer colonies in anchorage-independent conditions. LCC6 IR shRNA xenograft tumors in mice had reduced growth, angiogenesis and lymphangiogensis when compared with LCC6 wild-type cells. Accordingly, LCC6 IR shRNA clones produced less hypoxia-inducible factor-1alpha, vascular endothelial growth factor (VEGF)-A and VEGF-D. Furthermore, LCC6 IR shRNA cells formed fewer pulmonary metastases when compared with LCC6 wild-type cells. Using in vivo luciferase imaging, we have shown that LCC6 IR shRNA cells have less seeding and colonization potential in the lung and liver of mice than LCC6 cells. In conclusion, downregulation of IR inhibited cancer cell proliferation, angiogenesis, lymphangiogenesis and metastasis. Our data argue that IR should also be targeted in cancer therapy.

Journal Article

Animals; Anti-Bacterial Agents; Bacterial Proteins; Bacteriolysis; Bioware; Cell Wall; Gene Expression Profiling; Gene Knockout Techniques; Genes, Reporter; Lysostaphin; Mice; Microbial Sensitivity Tests; Sepsis; Staphylococcus aureus; Virulence; Xen29

Transcriptional profiling data accumulated in recent years for the clinically relevant pathogen Staphylococcus aureus have established a cell wall stress stimulon, which comprises a coordinately regulated set of genes that are upregulated in response to blockage of cell wall biogenesis. In particular, the expression of cwrA (SA2343, N315 notation), which encodes a putative 63 amino acid polypeptide of unknown biological function, increases over 100-fold in response to cell wall inhibition. Herein, we seek to understand the biological role that this gene plays in S. aureus. cwrA was found to be robustly induced by all cell wall-targeting antibiotics tested – vancomycin, oxacillin, penicillin G, phosphomycin, imipenem, hymeglusin and bacitracin – but not by antibiotics with other mechanisms of action, including ciprofloxacin, erythromycin, chloramphenicol, triclosan, rifampicin, novobiocin and carbonyl cyanide 3-chlorophenylhydrazone. Although a DeltacwrA S. aureus strain had no appreciable shift in MICs for cell wall-targeting antibiotics, the knockout was shown to have reduced cell wall integrity in a variety of other assays. Additionally, the gene was shown to be important for virulence in a mouse sepsis model of infection.

Journal Article

Animals; Bioware; Cell Line, Tumor; Electrochemotherapy; Electrodes; Female; Humans; Mammary Neoplasms, Experimental; MDA-MB-231-D3H1 cells; Mice; Mice, Nude; Needles; Xenograft Model Antitumor Assays

Irreversible electroporation (IRE) is a therapeutic technology for the ablation of soft tissues using electrodes to deliver intense but short electric pulses across a cell membrane, creating nanopores that lead to cell death. This phenomenon only affects the cell membrane, leaving the extracellular matrix and sensitive structures intact, making it a promising technique for the treatment many types of tumors. In this paper, we present the first in vivo study to achieve tumor regression using a translatable, clinically relevant single needle electrode for treatment administration. Numerical models of the electric field distribution for the protocol used suggest that a 1000 V/cm field threshold is sufficient to treat a tumor, and that the electric field distribution will slightly decrease if the same protocol were used on a tumor deep seated within a human breast. Tumor regression was observed in 5 out of 7 MDA-MB231 human mammary tumors orthotopically implanted in female Nu/Nu mice, with continued growth in controls.

Journal Article

Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents, Phytogenic; Bioware; Cell Line, Tumor; Drug Carriers; Female; Humans; Mice; Nanoparticles; Ovarian Neoplasms; Paclitaxel; Receptor, erbB-2; SKOV3-luc-D3 cells; Tissue Distribution; Xenograft Model Antitumor Assays

The benefit of polymeric immuno-nanoparticles (NPs-Tx-HER), consisting of paclitaxel (Tx)-loaded nanoparticles coated with anti-HER2 monoclonal antibodies (Herceptin, trastuzumab), in cancer treatment was assessed in a disseminated xenograft ovarian cancer model induced by intraperitoneal inoculation of SKOV-3 cells overexpressing HER2 antigens. The study was focused on the evaluation of therapeutic efficacy and biodistribution of NPs-Tx-HER compared to other Tx formulations. The therapeutic efficacy was determined by two methods: bioluminescence imaging and survival rate. The treatment regimen consisted in an initial dose of 20mg/kg Tx administered as 10mg/kg intravenously (IV) and 10mg/kg intraperitonealy (IP), followed by five alternative IP and IV injections of 10mg/kg Tx every 3 days. The bioluminescence study has clearly shown the superior anti-tumor activity of NPs-Tx-HER compared to free Tx. As a confirmation of these results, a significantly longer survival of mice was observed for NPs-Tx-HER treatment compared to free Tx, Tx-loaded nanoparticles coated with an irrelevant mAb (Mabthera, rituximab) or Herceptin alone, indicating the potential of immuno-nanoparticles in cancer treatment. The biodistribution pattern of Tx was assessed on healthy and tumor bearing mice after IV or IP administration. An equivalent biodistribution profile was observed in healthy mice for Tx encapsulated either in uncoated nanoparticles (NPs-Tx) or in NPs-Tx-HER. No significant difference in Tx biodistribution was observed after IV or IP injection, except for a lower accumulation in the lungs when NPs were administered by IP. Encapsulated Tx accumulated in the organs of the reticulo-endothelial system (RES) such as the liver and spleen, whereas free Tx had a non-specific distribution in all tested organs. Compared to free Tx, the single dose injection (IV or IP) of encapsulated Tx in mice bearing tumors induced a higher tumor accumulation. However, no difference in overall tumor accumulation between NPs-Tx-HER and NPs-Tx was observed. In conclusion, the encapsulation of Tx into NPs-Tx-HER immuno-nanoparticles resulted in an improved efficacy of drug in the treatment of disseminated ovarian cancer overexpressing HER2 receptors.