Synthetic Curcumin Analog: Inhibiting the Invasion, Angiogenesis, and Metastasis in Human Laryngeal Carcinoma Cells via NF-kB Pathway

Laryngeal carcinoma, the most common among head and neck squamous cell carcinoma (HNSCC) induces 1% of all cancer deaths. Curcumin, the active constituent of turmeric is more effective in the treatment of various cancer. In the present study, with an aim to explore the mechanistic role of BDMC-A as a chemotherapeutic agent, we have investigated the inhibitory effect of BDMC-A on invasion, angiogenesis, and metastasis in Hep-2 cells and compared it with curcumin. Curcumin and BDMC-A treated Hep-2 cells were quantified using western blotting and RT-PCR technique to investigate the effect of Curcumin and BDMC-A on transcription factors involved in signal transduction cascade, invasion and angiogenesis associated markers. Pro-inflammatory markers of curcumin and BDMC-A treated Hep-2 cells were estimated using the ELISA kit. The results showed that BDMC-A might exhibit the anti-cancer activity by inhibiting transcription factors mainly NF-κB, p65, c-Jun, c-Fos, STAT3, 5, PPAR-γ and β-catenin, which are responsible for tumor progression and malignancy. Downregulation of MMP-9, VEGF, IL-6 and IL-8 and upregulation of TIMP-2 levels further supports the anti-tumor potential of BDMC-A. Our overall results revealed that BDMC-A more effectively inhibited the markers of invasion, angiogenesis and metastasis in comparison with curcumin.

Increases of Lipophilic Antioxidants and Anticancer Activity of Coix Seed Fermented by Monascus purpureus

Lipophilic tocols, γ-oryzanol, and coixenolide in coix seed before and after fermentation by Monascus purpureus were determined. Antioxidant and anticancer activities of raw and fermented coix seed were evaluated using free-radical-scavenging assays and polyunsaturated fatty acid oxidation model, and human laryngeal carcinoma cell HEp2, respectively. Compared to the raw seed, the tocols, γ-oryzanol, and coixenolide contents increased approximately 4, 25, and 2 times, respectively, in the fermented coix seed. Especially, γ-tocotrienol and γ-oryzanol reached 72.5 and 655.0 μg/g in the fermented coix seed. The lipophilic extract from fermented coix seed exhibited higher antioxidant activity in scavenging free radicals and inhibiting lipid oxidation. The inhibitory concentrations for 50% cell survival (IC50) of lipophilic extract from fermented coix seed in inhibiting HEp2 cells decreased by 42%. This study showed that coix seed fermented by M. purpureus increased free and readily bioavailable lipophilic antioxidants and anticancer activity. Therefore, fermentation could enhance the efficacy of the health promoting function of coix seeds.

Effect and Mechanism of Survivin on Hypoxia-Induced Multidrug Resistance of Human Laryngeal Carcinoma Cells

This study aimed at clarifying the mechanism and role of survivin in hypoxia-induced multidrug resistance (MDR) of laryngeal carcinoma cells. Human laryngeal cancer cells were incubated under hypoxia or normoxia. The expression of survivin was silenced by performing RNA interference. Additionally, by Western blot and real-time quantitative RT-PCR, survivin expression was detected. The sensitivity of human laryngeal carcinoma cells to multiple drugs was measured by CCK-8 assay. Meanwhile, the apoptosis of cells induced by cisplatin or paclitaxel was assessed by Annexin-V/propidium iodide staining analysis. Under hypoxic conditions, the upregulation of survivin was abolished by RNA interference. Then, CCK-8 analysis demonstrated that the sensitivity to multiple agents of laryngeal carcinoma cells could be increased by inhibiting survivin expression (P<0.05). Moreover, Annexin-V/propidium iodide staining analysis revealed that decreased expression of survivin could evidently increase the apoptosis rate of laryngeal carcinoma cells that were induced by cisplatin or paclitaxel evidently (P<0.05). Our data suggests that hypoxia-elicited survivin may exert a pivotal role in regulating hypoxia-induced MDR of laryngeal cancer cells by preventing the apoptosis of cells induced by chemotherapeutic drug. Thus, blocking survivin expression in human laryngeal carcinoma cells may provide an avenue for gene therapy.

Aspernolide A Inhibits the Proliferation of Human Laryngeal Carcinoma Cells through the Mitochondrial Apoptotic and STAT3 Signaling Pathways

Aspernolide A, a butyrolactone secondary metabolite, was purified from the endophytic fungus Cladosporium cladosporioides derived from roots of Camptotheca acuminata Decne. In this study, the antitumor activity and mechanisms of aspernolide A on human laryngeal cancer Hep-2 and TU212 cells were studied by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, morphological observation and Western blotting. The results showed that aspernolide A significantly inhibited the proliferation of Hep-2 and TU212 cells in dose- and time-dependent manners. Morphological changes of apoptotic cells could be observed under an inverted microscope, such as irregular margins, decreased adherence ability and chromatin condensation. The expressions of Bax, Caspase-9, Caspase-3 and PARP (poly ADP-ribose polymerase) increased with the increase of dosage while Bcl-2 decreased, suggesting that the apoptotic mechanism might be related to the mitochondrial apoptotic pathway. Moreover, the expression of the phosphorylation of STAT3 decreased with the increase of dosage, suggesting that the apoptotic mechanism might be related to the STAT3 signaling pathway. All these conclusions indicated that aspernolide A has the potential anti-laryngocarcinoma effects.

TIMP-3 Increases the Chemosensitivity of Laryngeal Carcinoma to Cisplatin via Facilitating Mitochondria-Dependent Apoptosis

Laryngeal carcinoma is a type of head and neck carcinoma with a high incidence and mortality. Chemotherapy treatments of human laryngeal carcinoma may fail due to the development of chemoresistance. Tissue inhibitor of metalloproteinase 3 (TIMP-3) has been shown to be implicated in a number of pathological processes typical for cancer. The present study aims to investigate the involvement of TIMP-3 in the chemoresistance of laryngeal carcinoma. We showed that TIMP-3 expression was significantly decreased in chemoresistant laryngeal carcinoma tissues compared with chemosensitivity tissues. Patients with low TIMP-3 expression exhibited poorer overall survival than those with high TIMP-3 expression. Moreover, cisplatin-resistant Hep-2 cells (Hep-2/R) were associated with the inhibition of mitochondrial membrane potential (MtMP) depolarization after cisplatin challenge. In addition, cisplatin resulted in a more pronounced mitochondrial cytochrome c release into the cytoplasm in Hep-2 cells than in their resistant variants. Overexpression of TIMP-3 by an adenovirus encoding TIMP-3 cDNA remarkably enhanced cisplatin-induced apoptosis, cytochrome c release, and caspase activation in Hep-2/R cells, thereby sensitizing cancer cells to cisplatin. On the other hand, downregulation of TIMP-3 markedly inhibited cisplatin-induced apoptosis in Hep-2 cells through attenuating mitochondria-dependent pathway activation. Taken together, these results demonstrate that decreased TIMP-3 expression may contribute to cisplatin resistance via inhibition of mitochondria-dependent apoptosis, indicating that forced TIMP-3 expression may be a useful strategy to improve the efficacy of cisplatin to treat laryngeal carcinoma.