withaferin-a and Head-and-Neck-Neoplasms

Abnormal expression of claudin-1 (CLDN1) has important roles in carcinogenesis and metastasis in various cancers. The role of CLDN1 in human oral squamous cell carcinoma (OSCC) remains unknown. Here, we report the functional role of CLDN1 in metastasis of human OSCC, as a potential target regulated by withaferin A. From gene expression profiling with microarray technology, we found that the majority of notable differentially expressed genes were classified into migration/invasion category. Withaferin A impaired the motility of human OSCC cells in vitro and suppressed metastatic nodule formation in an in vivo metastasis model, both associated with reduced CLDN1. CLDN1 overexpression enhanced metastatic nodule formation in vivo, resulting in severe metastatic lesions in lung tissue. Moreover, CLDN1 expression was positively correlated to lymphatic metastasis in OSCC patients. The impaired motility of human OSCC cells upon withaferin A treatment was restored by CLDN1 overexpression. Furthermore, upregulation of let-7a induced by withaferin A was inversely correlated to CLDN1 expression. Overall, these give us an insight into the function of CLDN1 for prognosis and treatment of human OSCC, substantiating further investigation into the use of withaferin A as good anti-metastatic drug candidate.

Topics: Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Claudin-1; Gene Expression Regulation, Neoplastic; Head and Neck Neoplasms; Humans; Mouth Neoplasms; Squamous Cell Carcinoma of Head and Neck; Withanolides

The aim of this study was to determine the apoptotic activity of methanol extract of Ashwagandha (MEAG) and in human head and neck squamous cell carcinoma (HNSCC) cells and to investigate the underlying mechanisms.. We investigated the effects of MEAG on programmed cell death in HNSCC cells using a Live/Dead assay, detection of nuclear morphologic changes, Mitotracker, siRNA knockdown, and RT-PCR.. Treatment with MEAG showed dose-dependent growth-inhibitory activity that attribute to caspase-dependent apoptosis. Loss of mitochondrial membrane potential, release of cytochrome c, and activation of caspase 9 suggested that MEAG leads to activation of mitochondria-mediated apoptosis. MEAG selectively upregulated the expression of Bim protein at the transcriptional level and induced the translocation of Bim into the mitochondria. Knockdown of Bim by siRNA partially blocked MEAG-mediated apoptosis. MEAG also caused an increase in truncated Bid (t-Bid), cleaved caspase-8, and death receptor 5 (DR5). Interestingly, withaferin A (WA), a bioactive component of MEAG, clearly induced apoptosis accompanied by upregulation of Bim, t-Bid, caspase-8, and DR5 similar to the effects of MEAG.. These suggest that MEAG and WA may be potential natural materials for the treatment of HNSCC.

Topics: Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Bcl-2-Like Protein 11; Carcinoma, Squamous Cell; Caspase 8; Caspase 9; Cell Line, Tumor; Cytochromes c; Enzyme Activation; Head and Neck Neoplasms; Humans; Membrane Potential, Mitochondrial; Mitochondrial Membranes; Mouth Neoplasms; Plant Extracts; Receptors, TNF-Related Apoptosis-Inducing Ligand; Squamous Cell Carcinoma of Head and Neck; Up-Regulation; Withanolides

Withaferin A is a steroidal lactone purified from the Indian medicinal plant, Withania somnifera. Withaferin A has been shown to inhibit the proliferation, metastasis, invasion and angiogenesis of cancer cells. In the present study, we investigated whether withaferin A induces apoptosis in the human head and neck cancer cells, AMC-HN4. Withaferin A markedly increased the sub-G1 cell population and the cleavage of poly(ADP-ribose) polymerase (PARP), which are markers of apoptosis. Pan-caspase inhibitor, z-VAD-fmk (z-VAD), markedly inhibited the withaferin A-induced apoptosis. However, the withaferin A-induced increase in the expression of COX-2 was not affected by treatment with z-VAD. Furthermore, withaferin A upregulated cyclooxygenase-2 (COX-2) expression. The COX-2 inhibitor, NS-398, reduced the withaferin A-induced production of prostaglandin E2. However, treatment with NS-398 did not affect the sub-G1 population and the cleavage of PARP. In addition, the withaferin A-induced apoptosis was independent of reactive oxygen species production. Thiol donors [N-acetylcysteine (NAC) and dithiothreitol (DTT)] reversed withaferin A-induced apoptosis. Therefore, our data suggest that withaferin A induces apoptosis through the mechanism of thiol oxidation in head and neck carcinoma cells.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cyclooxygenase 2; Gene Expression; Head and Neck Neoplasms; Humans; Oxidation-Reduction; Reactive Oxygen Species; Signal Transduction; Sulfhydryl Compounds; Withanolides

As part of a program to discover drug leads from plant biodiversity, the present investigation was undertaken to explore the anticancer potential of compounds derived from selected Latin American plants. Bioassay-guided fractionation of a crude extract of the aerial parts of Vassobia breviflora led to the isolation of the withanolide-type steroidal lactone withaferin A (1). This compound was tested for antiproliferative activity against the head and neck squamous cell carcinoma (HNSCC) cell lines, MDA1986, JMAR, UM-SCC-2, and JHU011. The inhibitory concentrations to reduce cell viability to 50% (IC(50)) were determined by the MTS cytotoxicity assay, and 1 reduced cell viability with IC(50) values in the range 0.5-2.2 μM. A mechanistic study showed that 1 induces apoptosis and cell death in HNSCC cells as well as a cell-cycle shift from G(0)/G(1) to G(2)/M. Cells treated with 1 exhibited inactivation of Akt and a reduction in total Akt concentration. This investigation constitutes the first report of the antiproliferative activity of withaferin A (1) against head and neck squamous carcinoma.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Argentina; Carcinoma, Squamous Cell; Cell Cycle; Drug Screening Assays, Antitumor; Head and Neck Neoplasms; Humans; Molecular Structure; Plants, Medicinal; Solanaceae; Withanolides