thiostrepton and Nasopharyngeal-Neoplasms

Background Thiostrepton, a natural antibiotic, has recently been shown to be a potential anticancer drug for certain cancers, but its study in nasopharyngeal carcinoma (NPC) is still limited. The aims of this study were to investigate the anticancer effect of thiostrepton on NPC cells and to explore its underlying mechanism. Methods The effects of thiostrepton on the proliferation, migration, and invasion of NPC cells were investigated by a WST-1 assay, wound healing assay, and cell invasion assay, respectively. Microarrays were conducted and further analyzed by Ingenuity Pathways Analysis (IPA) to determine the molecular mechanism by which thiostrepton affects NPC cells. Results Our results showed that thiostrepton reduced NPC cell viability in a dose-dependent manner. Thiostrepton inhibited the migration and invasion of NPC cells in wound healing and cell invasion assays. The microarray data analyzed by IPA indicated the top 5 ingenuity canonical pathways, which were unfolded protein response, NRF2-mediated oxidative stress response, retinoate biosynthesis I, choline biosynthesis III, and pancreatic adenocarcinoma signaling. Conclusion Thiostrepton effectively suppressed NPC cell proliferation, migration, and invasion, likely by several mechanisms. Thiostrepton may be a potential therapeutic agent for treating NPC in the future.

Topics: Anti-Bacterial Agents; Antineoplastic Agents; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Gene Expression Regulation, Neoplastic; Humans; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Thiostrepton

High expression levels of the forkhead box M1 (FoxM1) transcription factor are associated with metastasis and poor prognosis of malignancies. However, little is known concerning its function in nasopharyngeal carcinoma (NPC). The present study aimed to investigate the impact of FoxM1 inhibition on the migration and invasion of NPC cells and the potential mechanisms. The effects of FoxM1 inhibitor treatment and FoxM1 silencing on the proliferation, migration and invasion of NPC CNE-1 and CNE-2 cells were examined by CCK-8, Transwell migration/invasion and colony formation assays. The effects of stable FoxM1 silencing on the growth and lung metastasis of implanted NPC were evaluated. The relative levels of FoxM1, zinc finger E-box binding homeobox 2 (ZEB2), Snail2 and E-cadherin in the different groups of NPC cells and tumors were determined by quantitative real-time PCR, western blotting and immunohistochemical assays. Treatment with thiostrepton, FoxM1 inhibitor, significantly reduced the survival of NPC cells. Treatment with thiostrepton and/or knockdown of FoxM1 inhibited the anchorage-independent proliferation, migration and invasion of NPC cells. Inhibition of FoxM1 also increased the relative levels of E-cadherin, but reduced ZEB2 and Snail2 expression in NPC cells. Stable FoxM1 silencing inhibited the growth and lung metastasis of implanted NPC in vivo, which was associated with increased levels of E-cadherin, but decreased ZEB2 and Snail2 expression in the NPC tumors. In conclusion, our data clearly indicate that knockdown of FoxM1 inhibited the growth and metastasis of human NPC by modulating epithelial-to-mesenchymal transition (EMT), and FoxM1 may be a potential target for the intervention of NPC.

Topics: Animals; Cadherins; Carcinoma; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Epithelial-Mesenchymal Transition; Forkhead Box Protein M1; Forkhead Transcription Factors; Gene Silencing; HEK293 Cells; Homeodomain Proteins; Humans; Mice; Mice, Nude; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Neoplasm Invasiveness; Neoplasm Transplantation; Repressor Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Snail Family Transcription Factors; Thiostrepton; Transcription Factors; Zinc Finger E-box Binding Homeobox 2

The forkhead box M1 (FOXM1) transcription factor plays an important role in the metastases of many cancers. Down-regulation of FOXM1 by its inhibitor, thiostrepton, can inhibit the metastatic potential of some cancers; however, there are few studies regarding the functional significance of FOXM1 and thiostrepton in the metastases of nasopharyngeal carcinoma (NPC) and the underlying mechanism.. Expression of FOXM1 in NPC, normal nasopharyngeal tissues, a NPC cell line (C666-1), and a nasopharyngeal epithelial cell line (NP69) was investigated by immunohistochemical staining, qRT-PCR, and Western blot. The correlation between FOXM1 expression and the clinical characteristics of patients was analyzed. Moreover, the effects of thiostrepton on expression of FOXM1 in C666-1 and NP69 cells, and the invasion and migration ability of C666-1 cells were examined. The expressions of MMP-2, MMP-9, fascin-1, ezrin, and paxillin were determined after treatment with thiostrepton.. FOXM1 was overexpressed in NPC and C666-1 cells compared with normal nasopharyngeal tissues and NP69 cells. Overexpression of FOXM1 was associated with lymph node metastasis and advanced tumor stage. Moreover, thiostrepton inhibited expression of FOXM1 in C666-1 cells in a dose-dependent manner, but had a minimal effect on NP69 cells. Thiostrepton inhibited the migration and invasion ability of C666-1 cells by down-regulating the expression of MMP-2, MMP-9, fascin-1, and paxillin.. Overexpression of FOXM1 is associated with metastases of NPC patients. Thiostrepton inhibits the metastatic ability of NPC cells by down-regulating the expression of FOXM1, MMP-2, MMP-9, fascin-1, and paxillin.

Topics: Adult; Aged; Carcinoma; Carrier Proteins; Cell Line, Tumor; Cell Movement; Cytoskeletal Proteins; Female; Forkhead Box Protein M1; Forkhead Transcription Factors; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Microfilament Proteins; Middle Aged; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Neoplasm Invasiveness; Neoplasm Metastasis; Paxillin; Thiostrepton

Nasopharyngeal carcinoma (NPC) is a head and neck malignant tumor rare throughout most of the world but common in Southern China. Forkhead box M1 (FoxM1) transcription factor has been shown to play important role in the development and progression of human cancers. We have previously found that FoxM1 was overexpressed in NPC patients and was associated with development of NPC. However, the exact functional significance of FoxM1 and its inhibitor thiostrepton in NPC is little known. The purpose of this study was to investigate in vitro activity of down-regulation of FoxM1 by thiostrepton or siRNA against NPC cell line. FoxM1 inhibition by thiostrepton or siRNA inhibited proliferation of NPC cells by down-regulation of cyclin D1 and cyclin E1. Transformation ability of NPC cells was suppressed by thiostrepton. FoxM1 inhibition by thiostrepton induced apoptosis of NPC cells by down-regulation of bcl-2, up-regulation of bax and p53, and inducing release of cytochrome c accompanied by activation of caspase-9, cleaved caspase-3 and cleaved PARP. In addition, FoxM1 inhibition by siRNA transfection also down-regulated expression of bcl-2 and up-regulated expression of bax, p53, cleaved caspase-3 and cleaved PARP. Furthermore, FADD and cleaved caspase-8 expression were up-regulated by thiostrepton or FoxM1 siRNA, and expression of cIAP1 and XIAP was inhibited by thiostrepton. At last, FoxM1 inhibition by thiostrepton reduced the expression of HIF-1α and VEGF, and transfection of FoxM1 siRNA decreased VEGF expression but not HIF-1α. Collectively, our finding suggest that FoxM1 inhibition by thiostrepton or siRNA suppresses proliferation, transformation ability, angiogenesis, and induces apoptosis of NPC.

Topics: Angiogenic Proteins; Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Carcinoma; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic; Dose-Response Relationship, Drug; Down-Regulation; Forkhead Box Protein M1; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; Humans; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Neovascularization, Physiologic; RNA Interference; Thiostrepton; Time Factors; Transfection