Melatonin acts synergistically with pazopanib against renal cell carcinoma cells through p38 mitogen-activated protein kinase-mediated mitochondrial and autophagic apoptosis.

BACKGROUND: Mounting evidence indicates that melatonin has possible activity against different tumors. Pazopanib is an anticancer drug used to treat renal cell carcinoma (RCC). This study tested the anticancer activity of melatonin combined with pazopanib on RCC cells and explored the underlying mechanistic pathways of its action. METHODS: The 786-O and A-498 human RCC cell lines were used as cell models. Cell viability and tumorigenesis were detected with the MTT and colony formation assays, respectively. Apoptosis and autophagy were assessed using TUNEL, annexin V/propidium iodide, and acridine orange staining with flow cytometry. The expression of cellular signaling proteins was investigated with western blotting. The in vivo growth of tumors derived from RCC cells was evaluated using a xenograft mouse model. RESULTS: Together, melatonin and pazopanib reduced cell viability and colony formation and promoted the apoptosis of RCC cells. Furthermore, the combination of melatonin and pazopanib triggered more mitochondrial, caspase-mediated, and LC3-II-mediated autophagic apoptosis than melatonin or pazopanib alone. The combination also induced higher activation of the p38 mitogen-activated protein kinase (p38MAPK) in the promotion of autophagy and apoptosis by RCC cells than melatonin or pazopanib alone. Finally, tumor xenograft experiments confirmed that melatonin and pazopanib cooperatively inhibited RCC growth in vivo and predicted a possible interaction between melatonin/pazopanib and LC3-II. CONCLUSION: The combination of melatonin and pazopanib inhibits the growth of RCC cells by inducing p38MAPK-mediated mitochondrial and autophagic apoptosis. Therefore, melatonin might be a potential adjuvant that could act synergistically with pazopanib for RCC treatment.

Induction of immunogenic cell death effect of licoricidin in cervical cancer cells by enhancing endoplasmic reticulum stress-mediated high mobility group box 1 expression.

Licoricidin (LCD) is an activity compound of the roots of Glycyrrhiza uralensis, which has therapeutic efficacy, including anti-virus, anti-cancer, and enhanced immunity in Traditional Chinese Medicine. Herein, this study aimed to clarify the effect of LCD on cervical cancer cells. In the present study, we found that LCD significantly inhibited cell viability via inducing cell apoptosis and companies with cleaved-PARP protein expression and caspase-3/-9 activity. Cell viability was markedly reversed these effects by pan-caspase inhibitor Z-VAD-FMK treatment. Furthermore, we showed that LCD-induced ER (endoplasmic reticulum) stress triggers upregulating the protein level of GRP78 (Bip), CHOP, and IRE1α, and subsequently confirmed the mRNA level by quantitative real-time polymerase chain reaction. In addition, LCD exhibited the release of danger-associated molecular patterns from cervical cancer cells, such as the release of high-mobility group box 1 (HMGB1), secretion of ATP, and exposure of calreticulin (CRT) on the cell surface, which led to immunogenic cell death (ICD). These results provide a novel foundation that LCD induces ICD via triggering ER stress in human cervical cancer cells. LCD might be an ICD inducer of immunotherapy in progressive cervical cancer.

Protodioscin Induces Apoptosis Through ROS-Mediated Endoplasmic Reticulum Stress via the JNK/p38 Activation Pathways in Human Cervical Cancer Cells.

BACKGROUND/AIMS: Protodioscin (PD) is a steroidal saponin with anti-cancer effects on a number of cancer cells, but the anti-tumor effects and mechanism of action of PD on human cervical cancer cells is unclear. METHODS: We determined cell viability using the MTT assay. Cell death, mitochondrial membrane potential (MMP), intracellular reactive oxygen species (ROS) generation, and endoplasmic reticulum (ER) stress were measured on a flow cytometry. Caspase activation, ER stress, and MMP-dependent apoptosis proteins in cervical cancer cells in response to PD were determined by Western blot analysis. The ability of ATF4 binding to ChIP promoter was measured using the ChIP assay. RESULTS: We demonstrated that PD inhibits cell viability, causes a loss of mitochondrial function, and induces apoptosis, as evidenced by up-regulation of caspase-8, -3, -9, -PARP, and Bax activation, and down-regulation of Bcl-2 expression. PD was shown to induce ROS and the ER stress pathway, including GRP78, p-eIF-2α, ATF4, and CHOP. Pre-treatment with NAC, a ROS production inhibitor, significantly reduced ER stress and apoptosis-related proteins induced by PD. Transfection of GRP78/CHOP-siRNA effectively inhibited PD-induced ER stress-dependent apoptosis. Moreover, treatment with PD significantly increased p38 and JNK activation. Co-administration of a JNK inhibitor (SP600125) or p38 inhibitor (SB203580) abolished cell death and ER stress effects during PD treatment. In addition, PD induced the expression of nuclear ATF4 and CHOP, as well as the binding ability of ATF4 to the CHOP promoter. CONCLUSION: Our results suggest that PD is a promising therapeutic agent for the treatment of human cervical cancer.

Dioscorea nipponica Makino inhibits migration and invasion of human oral cancer HSC-3 cells by transcriptional inhibition of matrix metalloproteinase-2 through modulation of CREB and AP-1 activity.

Oral cancer mortality has increased during the last decade due to the difficulties in treating related metastasis. Dioscorea nipponica Makino, a popular folk medicine, exerts anti-obesity and anti-inflammation properties. However, the effect of this folk medicine on metastasis of oral cancer has yet to be fully elucidated. The present study demonstrates that D. nipponica extracts (DNE), at a range of concentrations (0-50 µg/mL), concentration-dependently inhibited migration/invasion capacities of human oral cancer cells, HSC-3, without cytotoxic effects. The anti-migration effect of DNE was also observed in two other OSCC cell lines, Ca9-22 and Cal-27. Zymography, real time PCR, and Western blotting analyses revealed that DNE inhibited matrix metalloproteinase-2 (MMP-2) enzyme activity, and RNA and protein expression. The inhibitory effects of DNE on MMP-2 proceeded by up-regulating tissue inhibitor of metalloproteinase-2 (TIMP-2), as well as suppressing nuclear translocation and DNA binding activity of cAMP response element-binding (CREB) and activating protein-1 (AP-1) on the MMP-2 promoter in HSC-3 cells. In conclusion, DNE inhibited the invasion of oral cancer cells and may have potential use as a chemopreventive agent against oral cancer metastasis.