laq824 and Disease-Models--Animal

The purpose of the present study was to evaluate the relationship between hypoxia-inducible factor 1 alpha subunit (HIF1α) and tumor initiation in squamous cell carcinoma cell lines and whether targeting HIF1α perioperatively might exert positive effects on survival or recurrence in an animal model.. The expression of HIF1α and tumorigenic potential in nude mice was compared using human head and neck squamous cell carcinoma cell lines (SNU1041, SNU1066, SNU1076, PCI01, PCI13, PCI50). A recurrent tongue cancer model was established by first injecting tumor cells in the lateral tongue and then excising the tongue masses for replanting in the neck. The effect of HIF1α inhibitors was assessed using this animal model.. We observed good correlation between tumorigenic potential and HIF1α nuclear expression in the cell lines tested. Furthermore, knockdown of HIF1α inhibited tumor growth in the animal model. After in vitro testing of five HIF1α inhibitors, echinomycin and LAQ824 were selected for the animal study. Pre- and postoperative treatment with echinomycin showed significant improvement in postsurgery survival and recurrence.. Our results suggested that adjuvant targeting of HIF1α before and after surgery could be a new targeted therapy strategy for squamous cell carcinoma.

Topics: Animals; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Cell Movement; Cell Proliferation; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Humans; Hydroxamic Acids; Hypoxia-Inducible Factor 1, alpha Subunit; Mice; Mice, Nude; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Tongue Neoplasms; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Despite an excellent prognosis, certain patients with thyroid cancer suffer from locally invasive disease that cannot be controlled by conventional therapy. Our previous study suggested that hypoxia inducible factor-1-alpha (HIF1α) might be an important marker for the identification of and a treatment target of intractable thyroid cancer. Therefore, in the present study, we established an orthotopic mouse surgical model of thyroid cancer that mimics the clinical setting, and evaluated the effect of perioperative treatment with a HIF1α inhibitor.. Seven thyroid cancer cell lines (SNU-790, BCPAP, KTC1, TPC1, TPC1-M, KTC2, and FRO) and four HIF1α inhibitors (echinomycin, LAQ824, temsirolimus, and vorinostat) were used in the present study. Expression of HIF1α and related proteins was evaluated in all cell lines; immunoblotting and cell proliferation assays were conducted; and echinomycin was validated in an orthotopic surgical mouse model.. Nuclear expression of HIF1α increased in tumorigenic cell lines, while HIF1α inhibitors inhibited proliferation and colony formation. In the orthotopic surgical model, the group treated with surgery and the echinomycin-treatment group showed a highly significant survival gain (p=0.001) compared to the control group.. The highly significant survival gain resulting from their use in perioperative adjuvant treatment in vivo and their anticancer effect in vitro suggest that HIF1α inhibitors might be candidates for perioperative adjuvant chemotherapy for thyroid cancer. Combining adjuvant HIF1α inhibitor chemotherapy with surgery might be an effective therapeutic strategy for thyroid cancer that is refractory to conventional treatments.

Topics: Animals; Apoptosis; Cell Proliferation; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Humans; Hydroxamic Acids; Hypoxia-Inducible Factor 1, alpha Subunit; Mice; Neovascularization, Pathologic; Perioperative Period; Thyroid Neoplasms; Vorinostat

The aim of this work was to use phosphorus magnetic resonance spectroscopy ((31)P MRS) to investigate the pharmacodynamic effects of LAQ824, a histone deacetylase (HDAC) inhibitor. Human HT29 colon carcinoma cells were examined by (31)P MRS after treatment with LAQ824 and another HDAC inhibitor, suberoylanilide hydroxamic acid. HT29 xenografts and tumor extracts were also examined using (31)P MRS, pre- and post-LAQ824 treatment. Histone H3 acetylation was determined using Western blot analysis, and tumor microvessel density by immunohistochemical staining of CD31. Phosphocholine showed a significant increase in HT29 cells after treatment with LAQ824 and suberoylanilide hydroxamic acid. In vivo, the ratio of phosphomonoester/total phosphorus (TotP) signal was significantly increased in LAQ824-treated HT29 xenografts, and this ratio was inversely correlated with changes in tumor volume. Statistically significant decreases in intracellular pH, beta-nucleoside triphosphate (beta-NTP)/TotP, and beta-NTP/inorganic phosphate (Pi) and an increase in Pi/TotP were also seen in LAQ824-treated tumors. Tumor extracts showed many significant metabolic changes after LAQ824 treatment, in parallel with increased histone acetylation and decreased microvessel density. Treatment with LAQ824 resulted in altered phospholipid metabolism and compromised tumor bioenergetics. The phosphocholine and phosphomonoester increases may have the potential to act as pharmacodynamic markers for noninvasively monitoring tumor response after treatment with LAQ824 or other HDAC inhibitors.

Topics: Acetylation; Animals; Biomarkers, Tumor; Blotting, Western; Cell Cycle; Cell Proliferation; Colonic Neoplasms; Disease Models, Animal; Enzyme Inhibitors; Histone Deacetylase Inhibitors; Histones; HT29 Cells; Humans; Hydroxamic Acids; Immunoenzyme Techniques; Male; Mice; Mice, Nude; Nuclear Magnetic Resonance, Biomolecular; Phosphorus Isotopes; Phosphorylcholine; Tumor Cells, Cultured; Vorinostat; Xenograft Model Antitumor Assays

Stage III nonsmall cell lung cancer is primarily treated with combined chemotherapy and radiation therapy. Relapses for progression of disease within irradiated sites remains a primary pattern of failure. To evaluate the interaction between histone deacetylase inhibitors and irradiation in nonsmall cell lung cancer, we studied NVP-LAQ824 in mouse models of human lung cancer. Colony formation assays were performed to determine whether LAQ824 sensitized nonsmall cell lung cancer to the cytotoxic effects of ionizing radiation. LAQ824 reduced clonogenic survival of the H23 and H460 cell lines five-fold compared with controls and four-fold compared with either agent alone (P<0.001). Western blot analysis of caspase cleavage, microscopic analysis of nuclei and Annexin-fluorescein isothiocyanate/propidium iodide flow cytometry assays showed that LAQ824 enhanced radiation-induced apoptosis and attenuated mitosis (P<0.001). Immunostaining for gamma-H2AX nuclear foci was performed to determine the effect of LAQ824 on radiation-induced DNA double-strand breaks. Combined modality treatment delayed the resolution of gamma-H2AX foci with over 30% of cells staining positive 6 h after treatment versus approximately 5 and 3% in cells treated with LAQ824 or radiation alone (P<0.001). Additionally, an in-vivo xenograft model was utilized to study the effects of fractioned irradiation and LAQ824 on tumor growth. Fractioned irradiation and LAQ824 delayed tumor growth by 19 days versus 7 and 4 days for treatment with LAQ824 and radiation alone. This study shows the effectiveness of histone deacetylase inhibitors to enhance the cytotoxic effects of radiation by attenuating DNA repair and inducing apoptosis in human nonsmall cell lung cancer.

Topics: Animals; Apoptosis; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Colony-Forming Units Assay; Combined Modality Therapy; Disease Models, Animal; DNA Breaks, Double-Stranded; DNA Repair; Flow Cytometry; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Lung Neoplasms; Mice; Mitosis; Radiation-Sensitizing Agents; Radiation, Ionizing; Xenograft Model Antitumor Assays