Hydroquinone stimulates cell invasion through activator protein-1-dependent induction of MMP-9 in HepG2 human hepatoma cells

Anti-Inflammatory Effect of Protopine through MAPK and NF-κB Signaling Regulation in HepG2 Cell

Protopine is a substance used for hemostasis with an anti-inflammatory action and is one of the substances that are actively undergoing experiments to confirm their utility as anticancer agents. This study examined the molecular changes in the cellular signaling pathways associated with inflammatory responses in phorbol 12-myristate 13 acetate (PMA)-induced human hepatocellular carcinoma cell line (Hep G2). The inhibition of PMA-induced phosphorylation of I-κB in HepG2, the effect of protopine on the MAPK signals, the inhibition of COX-2 activity, and the inhibition of MMP-9 as a medium of inflammatory response were evaluated by Western blot and qPCR. The effect of protopine on the survival rates in HepG2 cells was evaluated and found to be stable to a processing concentration of up to 40μM. Subsequent Western blot analyses showed that protopine blocks the transfer of the MAPKs cell signals induced by PMA and the transfer of the subunit of the nuclear factor-kappa B (NF-κB) to the nucleolus. Protopine inhibited the kappa alpha (I-κBα) phosphorylation in the cytosol and blocked PMA-induced inflammation via COX-2 activity inhibition. The expression of MMP-9 at the gene and protein levels, which is associated with cell migration and metastasis, was reduced by protopine.

Recent Progress in Understanding the Action of Natural Compounds at Novel Therapeutic Drug Targets for the Treatment of Liver Cancer

Liver cancer is the third most common cause of cancer-related death following lung and stomach cancers. As a highly lethal disease, liver cancer is diagnosed frequently in less developed countries. Natural compounds extracted from herbs, animals and natural materials have been adopted by traditional Chinese medicine (TCM) practices and reported to be effective in the development of new medications for the treatment of diseases. It is important to focus on the mechanisms of action of natural compounds against hepatocellular carcinoma (HCC), particularly in terms of cell cycle regulation, apoptosis induction, autophagy mediation and cell migration and invasion. In this review, we characterize novel representative natural compounds according to their pharmacologic effects based on recently published studies. The aim of this review is to summarize and explore novel therapeutic drug targets of natural compounds, which could accelerate the discovery of new anticancer drugs.

A Mixture of Topical Forms of Polydeoxyribonucleotide, Vitamin C, and Niacinamide Attenuated Skin Pigmentation and Increased Skin Elasticity by Modulating Nuclear Factor Erythroid 2-like 2

It is well-known that increased oxidative stress caused by ultraviolet B (UV-B) radiation induces melanogenesis and activates metalloproteinases (MMPs), which degrade collagen and elastin fibers, leading to decreased skin elasticity. Various antioxidant agents, such as vitamin C and niacinamide, have been evaluated for use as treatments for photoaging or skin pigmentation. In this study, we evaluated the ability of a topical liquid formula of polydeoxyribonucleotide (PDRN), vitamin C, and niacinamide (PVN) delivered via a microneedling therapy system (MTS) to attenuate photoaging and pigmentation by increasing nuclear factor erythroid 2-like 2 (NRF2)/heme oxygenase-1 (HO-1) and decreasing MMP expression in a UV-B-radiated animal model. The effects of the PVN were compared with those of individual PDRN and hydroquinone (HQ) compounds. The expression of NRF2/HO-1 significantly increased in response to HQ, PDRN, and PVN in UV-B-radiated animal skin. The activity of nicotinamide adenine dinucleotide phosphate hydrogen oxidase decreased in response to HQ, PDRN, and PVN, and the superoxide dismutase activity increased. The expression of tumor protein p53 and microphthalmia-associated transcription factor and tyrosinase activity decreased in response to HQ, PDRN, and PVN, and this decrease was accompanied by decreased melanin content in the skin. The expression of nuclear factor kappa-light-chain enhancer of activated B cells and MMP2/3/9 decreased in response to HQ, PDRN, and PVN in UV-B-radiated skin. However, the expression of collagen type I α1 chain and the amount of collagen fibers that were evaluated by Masson's trichrome staining increased in response to HQ, PDRN, and PVN. The contents of elastin fibers, fibrillin 1/2 and fibulin 5 increased in response to HQ, PDRN, and PVN. In conclusion, PVN delivered via MTS led to decreased melanogenesis and destruction of collagen and elastin fibers by MMPs, and, thus, PVN decreased skin pigmentation and increased skin elasticity.

Hydroquinone exposure accumulates neutral lipid by the activation of CDP-DAG pathway in Saccharomyces cerevisiae

Benzene metabolites (HQ and BQ) are toxic compounds and their presence in human cause alteration in cellular respiration and kidney damage. In the current study, Saccharomyces cerevisiae has been used as a model organism and acute exposure of hydroquinone (HQ) decreased cell growth and increased reactive oxygen species (ROS). The expression of apoptosis regulatory genes (YCA1, NUC1, YSP1 and AIF1) were increased with HQ exposure in the wild-type cells. HQ exposure in the wild-type cells altered both the phospholipid and neutral lipid levels. Phosphatidylcholine is a vital membrane lipid that has a vital role in membrane biogenesis and was increased significantly with HQ. The neutral lipid results were supported with lipid droplets data and mRNA expression study. The phospholipid knockouts (Kennedy pathway) accumulated neutral lipids via the CDP-DAG (cytidine-diphosphate-diacylglycerol) pathway genes both in the presence and absence of HQ.

[Effectiveness and mechanism of pure platelet-rich plasma on osteochondral injury of talus]

OBJECTIVE

To explore the effectiveness and mechanism of pure platelet-rich plasma (P-PRP) on osteochondral injury of talus.

METHODS

Thirty-six patients with osteochondral injury of talus selected between January 2014 and October 2017 according to criteria were randomly divided into control group (group A), leukocyte PRP (L-PRP) group (group B), and P-PRP group (group C), with 12 cases in each group. There was no significant difference in gender, age, disease duration, and Hepple classification among the three groups ( P>0.05). Patients in the groups B and C were injected with 2.5 mL L-PRP or P-PRP at the bone graft site, respectively. Patients in the group A were not injected with any drugs. The American Orthopaedic Foot and Ankle Society (AOFAS) score and visual analogue scale (VAS) score were used to evaluate the effectiveness before operation and at 3, 6, and 12 months after operation. Study on the therapeutic mechanism of P-PRP: MC3T3-E1 cells were randomly divided into control group (group A), L-PRP group (group B), and P-PRP group (group C). Groups B and C were cultured with culture medium containing 5% L-PRP or P-PRP respectively. Group A was cultured with PBS of the same content. MTT assay was used to detect cell proliferation; ELISA was used to detect the content of matrix metalloprotein 9 (MMP-9) protein in supernatant; alkaline phosphatase (ALP) activity was measured; and real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expression of osteopontin (OPN), collagen type Ⅰ, and MMP-9 in cells. Western blot was used to detect the expression of MMP-9 in supernatant and phosphoinositide 3-kinase (PI3K), phosphorylated protein kinase B (pAKT), and phosphorylated c-Jun (p-c-Jun) in cells.

RESULTS

All patients were followed up 13-25 months, with an average of 18 months. No complication such as wound infection and internal fixation failure occurred. MRI showed that the degree of injury was similar between the three groups before operation, and patients in the three groups all recovered at 6 months after operation. Moreover, group C was superior to groups A and B. Compared with preoperation, AOFAS scores and VAS scores in the three groups were all significantly improved at each time point after operation ( P<0.05). AOFAS score of group C was significantly higher than that of groups A and B at 3, 6, and 12 months after operation ( P<0.05); there was no significant difference in VAS score between the three groups ( P>0.05). Study on the therapeutic mechanism of P-PRP: The absorbance ( A) value, ALP activity, the relative mRNA expression of OPN and collagen type Ⅰ in group C were significantly higher than those in groups A and B ( P<0.05), and those in group B were significantly higher than those in group A ( P<0.05). The relative expression of MMP-9 protein and mRNA and the content of MMP-9 protein detected by ELISA in group B were significantly higher than those in groups A and C, while those in group C were significantly lower than those in group A ( P<0.05). Western blot detection showed that the relative expression of PI3K, pAKT, and p-c-Jun protein in group B was significantly higher than those in groups A and C ( P<0.05), but there was no significant difference between groups A and C ( P>0.05).

CONCLUSION

P-PRP is superior to L-PRP for osteochondral injury of talus, which may be related to the inhibition of PI3K/AKT/AP-1 signaling pathway in the osteoblast, thereby reducing the secretion of MMP-9.

Apomorphine suppresses TNF-α-induced MMP-9 expression and cell invasion through inhibition of ERK/AP-1 signaling pathway in MCF-7 cells

Recent studies have shown that dopamine plays an important role in several types of cancer by inhibiting cell growth and invasion via dopamine receptors (DRs), such as dopamine receptor D2. However, the roles of DR agonists in cancer cell growth and invasion remain unclear. In our study, we found that apomorphine (APO), one of the most commonly prescribed DR agonists, inhibited TNF-α-induced matrix metalloprotease-9 (MMP-9) expression and cell invasion in MCF-7 human breast carcinoma cells through DR-independent pathways. Further mechanistic studies demonstrated that APO suppresses TNF-α-induced transcription of MMP-9 by inhibiting activator protein-1 (AP-1), a well-described transcription factor. This is achieved via extracellular signal-regulated kinases 1 and 2 (ERK1/2). Our study has demonstrated that APO targets human MMP-9 in a DR-independent fashion in MCF-7 cells, suggesting that APO is a potential anticancer agent that can suppress the metastatic progression of cancer cells.

Melatonin suppresses TPA-induced metastasis by downregulating matrix metalloproteinase-9 expression through JNK/SP-1 signaling in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), a disease common in the South-East Asian population, has high lymph node metastatic ability. Melatonin, an endogenously produced substance present in animals, plants, fungi, and bacteria, has oncostatic activity via several mechanisms. The molecular mechanisms involved in melatonin-mediated tumor inhibitory potential are not completely defined. Here, we show that melatonin treatment inhibits TPA-induced cell motility by regulating the matrix metalloproteinase-9 (MMP-9) expression in NPC. We also identified the signaling cascade through which melatonin inhibits MMP-9 expression; this involves melatonin regulating the binding activity of the transcription factor specificity protein-1 (SP-1)-DNA. Our mechanistic analysis further reveals that the c-Jun N-terminal kinase/mitogen-activated protein kinase pathway is involved in the melatonin-mediated tumor suppressor activity. Furthermore, the findings indicate a functional link between melatonin-mediated MMP-9 regulation and tumor suppressing ability and provide new insights into the role of melatonin-induced molecular and epigenetic regulation of tumor growth. Thus, we conclude that melatonin suppresses the motility of NPC by regulating TPA-induced MMP-9 gene expression via inhibiting SP-1-DNA binding ability. The results provide a functional link between melatonin-mediated SP-1 regulation and the antimetastatic actions of melatonin on nasopharyngeal carcinoma.