Parthenolide promotes apoptotic cell death and inhibits the migration and invasion of SW620 cells

BACKGROUND/AIMS: Parthenolide (PT), a principle component derived from feverfew (Tanacetum parthenium), is a promising anticancer agent and has been shown to promote apoptotic cell death in various cancer cells. In this study, we focused on its functional role in apoptosis, migration, and invasion of human colorectal cancer (CRC) cells. METHODS: SW620 cells were employed as representative human CRC cells. We performed the MTT assay and cell cycle analysis to measure apoptotic cell death. The wound healing, Transwell migration, and Matrigel invasion assays were performed to investigate the effect of PT on cell migration/invasion. Western blotting was used to establish the signaling pathway of apoptosis and cell migration/invasion. RESULTS: PT exerts antiproliferative effect and induces apoptotic cell death of SW620 cells. In addition, PT prevents cell migration and invasion in a dose-dependent manner. Moreover, PT markedly suppressed migration/invasion-related protein expression, including E-cadherin, β-catenin, vimentin, Snail, cyclooxygenase-2, matrix metalloproteinase-2 (MMP-2), and MMP-9 in SW620 cells. PT also inhibited the expression of antiapoptotic proteins (Bcl-2 and Bcl-xL) and activated apoptosis terminal factor (caspase-3) in a dose-dependent manner. CONCLUSIONS: Our results suggest that PT is a potential novel therapeutic agent for aggressive CRC treatment.

Balsalazide Potentiates Parthenolide-Mediated Inhibition of Nuclear Factor-kappaB Signaling in HCT116 Human Colorectal Cancer Cells

BACKGROUND/AIMS: Balsalazide is an anti-inflammatory drug used in the treatment of inflammatory bowel disease. Balsalazide can reduce inflammatory responses via several mechanisms, including inhibition of nuclear factor-kappaB (NF-kappaB) activity. Parthenolide (PT) inhibits NF-kappaB and exerts promising anticancer effects by promoting apoptosis. The present investigated the antitumor effects of balsalazide, combined with PT, on NF-kappaB in a representative human colorectal carcinoma cell line, HCT116. METHODS: We counted cells and conducted annexin-V assays and cell cycle analysis to measure apoptotic cell death. Western blotting was used investigate the levels of proteins involved in apoptosis. RESULTS: PT and balsalazide produced synergistic anti-proliferative effects and induced apoptotic cell death. The combination of balsalazide and PT markedly suppressed nuclear translocation of the NF-kappaB p65 subunit and the phosphorylation of inhibitor of NF-kappaB. Moreover, PT and balsalazide dramatically enhanced NF-kappaB p65 phosphorylation. Apoptosis, through the mitochondrial pathway, was confirmed by detecting effects on Bcl-2 family members, cytochrome c release, and activation of caspase-3 and -8. CONCLUSIONS: Combination treatment with PT and balsalazide may offer an effective strategy for the induction of apoptosis in HCT116 cells.

Parthenolide Sensitizes Human Colorectal Cancer Cells to Tumor Necrosis Factor-related Apoptosis-inducing Ligand through Mitochondrial and Caspase Dependent Pathway

BACKGROUND/AIMS: Combination therapy utilizing tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in conjunction with other anticancer agents, is a promising strategy to overcome TRAIL resistance in malignant cells. Recently, parthenolide (PT) has proved to be a promising anticancer agent, and several studies have explored its use in combination therapy. Here, we investigated the molecular mechanisms by which PT sensitizes colorectal cancer (CRC) cells to TRAIL-induced apoptosis. METHODS: HT-29 cells (TRAIL-resistant) were treated with PT and/or TRAIL for 24 hours. The inhibitory effect on proliferation was detected using the 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Annexin V staining, cell cycle analysis, and Hoechst 33258 staining were used to assess apoptotic cell death. Activation of an apoptotic pathway was confirmed by Western blot. RESULTS: Treatment with TRAIL alone inhibited the proliferation of HCT 116 cells in a dose-dependent manner, whereas proliferation was not affected in HT-29 cells. Combination PT and TRAIL treatment significantly inhibited cell growth and induced apoptosis of HT-29 cells. We observed that the synergistic effect was associated with misregulation of B-cell lymphoma 2 (Bcl-2) family members, release of cytochrome C to the cytosol, activation of caspases, and increased levels of p53. CONCLUSION: Combination therapy using PT and TRAIL might offer an effetive strategy to overcome TRAIL resistance in certain CRC cells.

Synergistic Effect of Parthenolide in Combination with 5-Fluorouracil in SW480 Cells

BACKGROUND/AIMS: Parthenolide (PT) is responsible for the bioactivities of Feverfew. Besides its potent anti-inflammatory effect, this compound has recently been reported to induce apoptosis in cancer cells. Unfortunately, many of the therapies that use 5-fluorouracil (5-FU) alone or in combination with other agents are likely to become ineffective due to drug resistance. In the present study, we investigate the antitumor effect of PT combined with 5-FU on colorectal cancer cells. METHODS: SW480 cell was employed as a representative of human colorectal carcinoma (CRC) cells. We performed MTT, annexin-V assay, and Hoechst 33258 staining to measure the synergistic effect. Western blotting was used to demonstrate apoptotic pathway. RESULTS: Our result demonstrated that PT inhibited the viability of colorectal cancer cells and had synergistic anti-proliferation in combination with 5-FU. After combined treatment of 5-FU and PT, enhanced apoptotic cell death is observed using annexin-V FITC assay and it was revealed by the condensed chromatin and fragmented DNA. Compared with 5-FU or PT alone, the apoptosis of colorectal cancer cells treated with PT and 5-FU enhanced the activation of caspase-8, caspase-3. CONCLUSIONS: Combined treatment with PT may offer an efficacious strategy to overcome 5-FU resistance in certain CRC cells.

Folate Receptor Targeted Imaging Using Poly (ethylene glycol)-folate: In Vitro and In Vivo Studies

The aim of this study was to ascertain the folate receptor (FR) targetability by an in vitro study and to acquire FR-targeted images in vivo models by using synthetic folate conjugates. PEG-folate was synthesized and labeled with (99m)Tc and fluorescein isothiocynate (FITC). Cell uptake studies were carried out in KB cells (FR-positive) and A549 cells (FR-negative) using FITC- and the (99m)Tc-labeled conjugates. The radiolabeled conjugate was intravenously injected to KB tumor xenografted mice. After it was injected, gamma images were recorded at 30 min, 1, 2, 3 and 4 hr. Cell uptake studies showed a difference between the KB cells and the A549 cells by flow cytometry analysis and gamma counting. On in vivo images, the tumor-tonormal muscle ratio was greater than 4. It ascertained that the PEG-folate conjugate specifically binds to the FR expressed on tumor cells in vitro. Moreover, it was possible to acquire the FR-targeted gamma images using PEG-folate conjugates in tumor models.

A Study on the Labeling Efficiency and Cytotoxicity of Hepatocyte-targeting Galactosylated Chitosan Compounds / 대한핵의학회잡지

PURPOSE: In prior study, we synthesized 99mTc-galactosylated chitosan (GC) and performed in vivo biodistribution study, showed specific targeting to hepatocyte. The aim of this study is to evaluate the labeling efficiency and cytotoxicity of modified galactosylated chitosan compounds, galactosyl methylated chitosan (GMC) and HYNIC-galactosylated chitosan (GCH). MATERIALS AND METHODS: GC, GMC and GCH were synthesized and radiolabeled with 99mTc. Then, they were incubated for 6 hours at room temperature and human serum at 37 degrees C. Labeling efficiencies were determined at 15, 30 m, 1, 2, 3 and 6 h after radiolabeling. To evaluate cytotoxicity, MTT assay was performed in HeLa and HepG2 cells. RESULTS: In comparison with them of 99mTc-GC, labeling efficiencies of 99mTc-GMC were significantly improved (100, 97 and 89% in acetone and 96.3, 95.8 and 75.6% in saline at 15 m, 1 and 6 h, respectively). Moreover, 99mTc-GCH showed more improved labeling efficiencies (> 95% in acetone and human serum and > 90% in saline at 6 h). In MTT assay, cytotoxicity was very low and not different from that of controls. CONCLUSION: These results represent that these compounds are radiochemically compatible radiopharmaceuticals, can be used in hepatocyte specific imaging study and in vivo gene or drug delivery monitoring.