bay-11-7082 and Thyroid-Neoplasms

Expression of the oncogene Twist1 is correlated with tumor development and metastasis. Recent studies have suggested that the epithelial-to-mesenchymal transition (EMT) is necessary for tumor progression and metastases. Little is known concerning the role of Twist1 and EMT in thyroid cancer. In the present work, the expression levels of Twist1 and one marker of EMT, vimentin, were measured in papillary thyroid carcinoma (PTC). The results showed Twist1 expression to be correlated only with cancer lymph node metastases (P = 0.004) and not with other clinicopathological indicators. Moreover, Twist1 expression was positively correlated with the expression of vimentin (r = 0.408, P = 0.003). In vitro studies further indicated that reducing Twist1 expression using short hairpin RNA against Twist1 can decrease the invasive and metastatic properties of PTC cells and that the down-regulation of Twist1 can reverse EMT by increasing the expression of E-cadherin and down-regulating the expression of vimentin in the PTC cell line IHH-4. To investigate the effects on Twist1, the PTC cell lines TPC-1 and BCPAP were treated with TNF-α, resulting in Twist1 up-regulation that was dependent on NF-κB activation. After the inhibition of NF-κB activity with Bay11-7082, the Twist1 mRNA and protein levels could not be increased. The decline in the Twist1 mRNA and protein levels rendered the cancer cells less invasive. Thus, we conclude that Twist1 plays an important role in the EMT of PTC via the NF-κB pathway.

Topics: Adolescent; Adult; Aged; Cadherins; Carcinoma, Papillary; Cell Line, Tumor; Child; Epithelial-Mesenchymal Transition; Female; Humans; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Invasiveness; NF-kappa B; Nitriles; Nuclear Proteins; Signal Transduction; Sulfones; Thyroid Neoplasms; Tumor Necrosis Factor-alpha; Twist-Related Protein 1; Up-Regulation; Vimentin; Young Adult

To evaluate changes of nuclear factor-kappa B (NF-κB) during radioiodine 131 ((131)I) therapy and whether NF-κB inhibition could enhance (131)I-induced apoptosis in differentiated thyroid cancer (DTC) cells in a synergistic manner.. Three human DTC cell lines were used. NF-κB inhibition was achieved by using a NF-κB inhibitor (Bay 11-7082) or by p65 siRNA transfection. Methyl-thiazolyl-tetrazolium assay was performed for cell viability assessment. DNA-binding assay, luciferase reporter assay, and Western blot were adopted to determine function and expression changes of NF-κB. Then NF-κB regulated anti-apoptotic factors XIAP, cIAP1, and Bcl-xL were measured. Apoptosis was analyzed by Western blot for caspase 3 and PARP, and by flow cytometry as well. An iodide uptake assay was performed to determine whether NF-κB inhibition could influence radioactive iodide uptake.. The methyl-thiazolyl-tetrazolium assay showed significant decrease of viable cells by combination therapy than by mono-therapies. The DNA-binding assay and luciferase reporter assay showed enhanced NF-κB function and reporter gene activities due to (131)I, yet significant suppression was achieved by NF-κB inhibition. Western blot proved (131)I could increase nuclear NF-κB concentration, while NF-κB inhibition reduced NF-κB concentration. Western blot also demonstrated significant up-regulation of XIAP, cIAP1, and Bcl-xL after (131)I therapy. And inhibition of NF-κB could significantly down-regulate these factors. Finally, synergism induced by combined therapy was displayed by significant enhancements of cleaved caspase 3 and PARP from Western blot, and of Annexin V positively staining from flow cytometry. The iodine uptake assay did not show significant changes when NF-κB was inhibited.. We demonstrated that (131)I could induce NF-κB activation, which would attenuate (131)I efficacy in DTC cells. NF-κB inhibition by Bay 11-7082 or by p65 siRNA transfection was effective in suppressing NF-κB regulated anti-apoptotic changes and in combined regimen apoptosis was achieved synergistically.

Topics: Apoptosis; Base Sequence; bcl-X Protein; Cell Differentiation; Cell Line, Tumor; Combined Modality Therapy; Humans; Inhibitor of Apoptosis Proteins; Iodine Radioisotopes; NF-kappa B; Nitriles; RNA, Small Interfering; Sulfones; Thyroid Neoplasms; Transcription Factor RelA; Transfection; X-Linked Inhibitor of Apoptosis Protein

Nuclear factor-kappa B (NF-κB) plays a key role in cancer development and therapy resistance. We aimed to determine whether NF-κB inhibition can enhance (131)I efficacy in differentiated thyroid cancer (DTC) in vivo.. Every nude mouse was ip injected with 1mCi of (131)I for thyroid ablation. Four weeks later, DTC cells were implanted. Another six weeks later, mice received four types of therapies, namely control vehicle, 1mCi of (131)I once, 10mg/kg of Bay 11-7082 (a NF-κB inhibitor) trice and combination treatment. Pre-ablation (99m)Tc-pertechnetate imaging, post ablative and post therapeutic imaging were performed. Target-to-background ratios (T/Bs) on xenograft tumors were calculated and compared. Nuclear extract from tumor samples were assessed by DNA-binding assay and Western blot. Apoptotic indices by TUNEL assay were determined and tumor volume curve was drawn to compare therapeutic effects in different groups.. Post therapeutic imaging displayed (131)I-avidity of xenograft tumors and completeness of thyroid ablation. T/Bs comparison showed no significant differences in mice received either (131)I mono-therapy or combined therapy. DNA-binding assay and Western blot showed enhanced function and expression of NF-κB by (131)I, which were inhibited substantially by Bay 11-7082 combination. Apoptotic indices were significantly increased by combined treatment than by any mono-therapy. And DTC lesional volumes were significantly regressed by combined treatment than by any mono-therapy.. We demonstrated that NF-κB inhibition can be a good interventional avenue to enhance therapeutic potentiation of (131)I on the in vivo management of DTC.

Topics: Animals; Apoptosis; Blotting, Western; Chemoradiotherapy; In Situ Nick-End Labeling; Iodine Radioisotopes; Mice; Mice, Nude; NF-kappa B; Nitriles; Sulfones; Thyroid Neoplasms; Transplantation, Heterologous; Treatment Outcome

Nuclear factor-kappaB (NF-kappaB) is constitutively activated in many cancers and plays a key role in promoting cell proliferation, survival, and invasion. Our understanding of NF-kappaB signaling in thyroid cancer, however, is limited. In this study, we have investigated the role of NF-kappaB signaling in thyroid cancer cell proliferation, invasion, and apoptosis using selective genetic inhibition of NF-kappaB in advanced thyroid cancer cell lines.. Three pharmacologic inhibitors of NF-kappaB differentially inhibited growth in a panel of advanced thyroid cancer cell lines, suggesting that these NF-kappaB inhibitors may have off-target effects. We therefore used a selective genetic approach to inhibit NF-kappaB signaling by overexpression of a dominant-negative IkappaBalpha (mIkappaBalpha). These studies revealed decreased cell growth in only one of five thyroid cancer cell lines (8505C), which occurred through a block in the S-G2/M transition. Resistance to TNFalpha-induced apoptosis was observed in all cell lines, likely through an NF-kappaB-dependent mechanism. Inhibition of NF-kappaB by mIkappaBalpha sensitized a subset of cell lines to TNFalpha-induced apoptosis. Sensitive cell lines displayed sustained activation of the stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK) pathway, defining a potential mechanism of response. Finally, NF-kappaB inhibition by mIkappaBalpha expression differentially reduced thyroid cancer cell invasion in these thyroid cancer cell lines. Sensitive cell lines demonstrated approximately a two-fold decrease in invasion, which was associated with differential expression of MMP-13. MMP-9 was reduced by mIkappaBalpha expression in all cell lines tested.. These data indicate that selective inhibition of NF-kappaB represents an attractive therapeutic target for the treatment of advanced thyroid. However, it is apparent that global regulation of thyroid cancer cell growth and invasion is not achieved by NF-kappaB signaling alone. Instead, our findings suggest that other important molecular processes play a critical role in defining the extent of NF-kappaB function within cancer cells.

Topics: Apoptosis; Blotting, Western; Cell Line, Tumor; Enzyme Inhibitors; Humans; Neoplasm Invasiveness; NF-kappa B; Nitriles; Oleanolic Acid; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Sulfones; Thyroid Neoplasms