Isoliquiritigenin inhibits migration and invasion of prostate cancer cells: possible mediation by decreased JNK/AP-1 signaling

Isoliquiritigenin (ISL, 4,2′,4′-trihydroxychalcone), which is found in licorice, shallot and bean sprouts, is a potent antioxidant with anti-inflammatory and anti-carcinogenic effects. The purpose of this study was to investigate the effects of ISL treatment on the migration, invasion and adhesion characteristics of DU145 human prostate cancer cells. DU145 cells were cultured in the presence of 0–20 μmol/L ISL with or without 10 μg/L epidermal growth factor (EGF). ISL inhibited basal and EGF-induced cell migration, invasion and adhesion dose dependently. ISL decreased EGF-induced secretion of urokinase-type plasminogen activator (uPA), matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), and vascular endothelial growth factor (VEGF), but increased TIMP-2 secretion in a concentration-dependent manner. In addition, ISL decreased the protein levels of integrin-α2, intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM), and mRNA levels of uPA, MMP-9, VEGF, ICAM and integrin-α2. Furthermore, basal and EGF-induced activator protein (AP)-1 binding activity and phosphorylation of Jun N-terminal kinase (JNK), c-Jun and Akt were decreased after ISL treatment. However, phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase was not altered. The JNK inhibitor SP600125 inhibited basal and EGF-induced secretion of uPA, VEGF, MMP-9 and TIMP-1, as well as AP-1 DNA binding activity and cell migration. These results provide evidence for the role of ISL as a potent antimetastatic agent, which can markedly inhibit the metastatic and invasive capacity of prostate cancer cells. The inhibition of JNK/AP-1 signaling may be one of the mechanisms by which ISL inhibits cancer cell invasion and migration.     

Resveratrol inhibits EMMPRIN expression via P38 and ERK1/2 pathways in PMA-induced THP-1 cells

The extracellular matrix metalloproteinase inducer (EMMPRIN) is significant in the regulation of matrix metalloproteinase (MMP) synthesis in atherosclerosis-related cells, and is possibly involved in the progression of atherosclerotic plaque. EMMPRIN expression is also up-regulated in PMA-induced THP-1 cells and is inhibited by resveratrol. However, it remains unclear how resveratrol inhibits EMMPRIN expression. We thus investigated the role of the MAPK signaling pathway in resveratrol inhibiting the up-regulation of EMMPRIN in PMA-induced THP-1 cells. We found that the ERK1/2 and p38 pathways, but not the JNK, are activated during the up-regulation of EMMPRIN expression. We also observed that while resveratrol suppresses the up-regulation of EMMPRIN, it also suppresses both the ERK1/2 and p38 pathways in a dose-dependent manner. Taken together, we established that it is through both the ERK1/2 and p38 MAPK pathways that resveratrol inhibits the expression of EMMPRIN in PMA-induced THP-1 cells.     

Pancreatic cancer stimulates pancreatic stellate cell proliferation and TIMP-1 production through the MAP kinase pathway

Pancreatic adenocarcinoma is characterized by an intense desmoplastic reaction that surrounds the tumor. Pancreatic stellate cells (PSCs) are thought to be responsible for production of this extracellular matrix. When activated, PSCs have a myofibroblast phenotype and produce not only components of the extracellular matrix including collagen, fibronectin, and laminin, but also matrix metalloproteinases and tissue inhibitors of metalloproteinases (TIMPs). Since PSCs are found in the stroma surrounding human pancreatic adenocarcinoma, we postulate that pancreatic cancer could impact PSC proliferation and TIMP-1 production. Rat PSCs were isolated and cultured. Isolated PSCs were exposed to PANC-1 conditioned medium (CM) and proliferation, activation of the mitogen-activated protein (MAP) kinase pathway, and TIMP-1 gene induction were determined. Exposure to PANC-1 CM increased PSC DNA synthesis, cell number, and TIMP-1 mRNA (real-time PCR) as well as activating the extracellular-regulated kinase (ERK) 1/2. Inhibition of ERK 1/2 phosphorylation (U0126) prevented the increases in growth and TIMP-1 expression. PANC-1 CM stimulates PSC proliferation and TIMP-1 through the MAP kinase (ERK 1/2) pathway.     

Matrix metalloproteinase-9,-3 and tissue inhibitor of matrix metalloproteinase-1 in colorectal cancer: relationship to clinicopathological variables

The balance between matrix metalloproteinases (MMPs) and their physiological tissue inhibitors of matrix metalloproteinases (TIMPs) is crucial in tumour invasion and progression. The aim of this study was to investigate the levels of MMP-9, MMP-3 and TIMP-1 in colorectal cancer (CRC) and to evaluate these proteinases and their inhibitor with respect to clinicopathological variables. Activities of pro- and active MMP-9 were measured in paired tumour and distant normal tissue specimens from 43 patients with CRC using gelatin zymography. ELISA was employed for the determination of MMP-9, MMP-3 and TIMP-1 protein expressions. The activity levels of pro- and active MMP-9 and protein expression levels of MMP-9, MMP-3 and TIMP-1 were higher in tumour tissues than in the corresponding normal tissues; the differences being significant for all (p < 0.05), except TIMP-1. Similarly, active MMP-9/proMMP-9 and the ratio of protein expression level of MMP-9-TIMP-1 were found to be significantly higher in tumour tissues ( p < 0.01). Among all the clinicopathological variables investigated, significant correlations were found between MMP-9 and presence of perineural invasion, MMP-3 and lymph node status, TIMP-1 and tumour differentiation, MMP-9/TIMP-1 ratio and histological types ( p < 0.05). In conclusion, MMP-3 was not as notably increased as MMP-9 in tumour tissues. However, different roles may be attributed to MMP-9 and MMP-3 in CRC development and progression. Additionally, assessment of TIMP-1 in relation to MMPs appeared to be crucial in CRC studies to provide a basis for the re-evaluation of the clinical usefulness of TIMP-1 in colorectal cancer.     

Specific blockade of the ERK pathway inhibits the invasiveness of tumor cells: down-regulation of matrix metalloproteinase-3/-9/-14 and CD44

Elevated expression of matrix metalloproteinases (MMPs) is associated with increased metastatic potential in many tumor cells. As activation of the ERK pathway has been linked to the expression of MMP-9, we examined a possible correlation between ERK activation, MMP-9 expression, and invasive phenotype in human tumor cells. Activation state of the ERK pathway in tumor cells was well correlated with the invasive phenotype, which was determined by the ability of cells to invade through reconstituted extracellular matrix. Elevated expression of MMP-9 as well as of MMP-3, MMP-14, and CD44 was observed in tumor cells in which constitutive activation of the ERK pathway is detected. Blockade of the ERK pathway by treatment with PD184352, a specific and powerful inhibitor of mitogen-activated protein (MAP) kinase/ERK kinase (MEK), suppressed the expression of MMP-3, MMP-9, MMP-14, and CD44, and inhibited markedly the invasiveness of tumor cells. These results imply that, in addition to anti-proliferative effects, specific blockade of the ERK pathway is expected to result in anti-metastatic effects in tumor cells.     

SLC9A3R1 stimulates autophagy via BECN1 stabilization in breast cancer cells

Autophagy, a self-catabolic process, has been found to be involved in abrogating the proliferation and metastasis of breast cancer. SLC9A3R1 (solute carrier family 9, subfamily A [NHE3, cation proton antiporter 3], member 3 regulator 1), a multifunctional scaffold protein, is involved in suppressing breast cancer cells proliferation and the SLC9A3R1-related signaling pathway regulates the activation of autophagy processes. However, the precise regulatory mechanism and signaling pathway of SLC9A3R1 in the regulation of autophagy processes in breast cancer cells remains unknown. Here, we report that the stability of BECN1, the major component of the autophagic core lipid kinase complex, is augmented in SLC9A3R1-overexpressing breast cancer MDA-MB-231 cells, subsequently stimulating autophagy by attenuating the interaction between BECN1 and BCL2. Initially, we found that SLC9A3R1 partially stimulated autophagy through the PTEN-PI3K-AKT1 signaling cascade in MDA-MB-231 cells. SLC9A3R1 then attenuated the interaction between BECN1 and BCL2 to stimulate the autophagic core lipid kinase complex. Further findings revealed that SLC9A3R1 bound to BECN1 and subsequently blocked ubiquitin-dependent BECN1 degradation. And the deletion of the C-terminal domain of SLC9A3R1 resulted in significantly reduced binding to BECN1. Moreover, the lack of C-terminal of SLC9A3R1 neither reduced the ubiquitination of BECN1 nor induced autophagy in breast cancer cells. The decrease in BECN1 degradation induced by SLC9A3R1 resulted in the activity of autophagy stimulation in breast cancer cells. These findings indicate that the SLC9A3R1-BECN1 signaling pathway participates in the activation of autophagy processes in breast cancer cells.     

UDN glycoprotein inhibits activator protein-1 and matrix metalloproteinase-9 via blocking of oxygen radicals in HT-29 cells

The present study was performed to investigate the anti-inflammatory potential of a 116-kDa glycoprotein isolated from Ulmus davidiana Nakai (UDN glycoprotein) in lipopolysaccaride (LPS)-treated cancerous human colon epithelial cells (HT-29 cells). UDN glycoprotein inhibited the production of intracellular superoxide anion (O₂^·−), hydrogen peroxides (H₂O₂), and nitric oxide (NO), whereas normalized the activity of anti-oxidant enzymes [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX)], accompanying the inhibition of manganese-superoxide dismutases (Mn-SOD) activity in LPS-treated HT-29 cells. In addition, UDN glycoprotein blocked the DNA binding activity of activator protein-1 (AP-1) through suppression of c-Jun and c-Fos activities, respectively. We also evaluated the anti-inflammatory potential of UDN glycoprotein based on the activity of the pro-inflammatory signal mediators [inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and matrix metalloproteinases-9 (MMP-9)]. The results showed that UDN glycoprotein (200 μg/ml) has an inhibitory effect on the activation of iNOS, COX-2, and MMP-9 proteins in the LPS-treated HT-29 cells. From these results, we suggest that UDN glycoprotein is one of the potential anti-inflammatory agents that blocks LPS-mediated inflammatory signal pathway in HT-29 cells. Here, we speculate that UDN glycoprotein could be used as an antioxidative agent for inflammatory gastrointestinal cancers.     

Suppressive effects of electrochemically reduced water on matrix metalloproteinase-2 activities and in vitro invasion of human fibrosarcoma HT1080 cells

It has been demonstrated that hydrogen peroxide (H(2)O(2)) is directly associated with elevated matrix metalloproteinase-2 (MMP-2) expression in several cell lines. Electrochemically reduced water (ERW), produced near the cathode during electrolysis, and scavenges intracellular H(2)O(2) in human fibrosarcoma HT1080 cells. RT-PCR and zymography analyses revealed that when HT1080 cells were treated with ERW, the gene expression of MMP-2 and membrane type 1 MMP and activation of MMP-2 was repressed, resulting in decreased invasion of the cells into matrigel. ERW also inhibited H(2)O(2)-induced MMP-2 upregulation. To investigate signal transduction involved in MMP-2 downregulation, mitogen-activated protein kinase (MAPK)-specific inhibitors, SB203580 (p38 MAPK inhibitor), PD98059 (MAPK/extracellular regulated kinase kinase 1 inhibitor) and c-Jun NH(2)-terminal kinase inhibitor II, were used to block the MAPK signal cascade. MMP-2 gene expression was only inhibited by SB203580 treatment, suggesting a pivotal role of p38 MAPK in regulation of MMP-2 gene expression. Western blot analysis showed that ERW downregulated the phosphorylation of p38 both in H(2)O(2)-treated and untreated HT1080 cells. These results indicate that the inhibitory effect of ERW on tumor invasion is due to, at least in part, its antioxidative effect.     

Progestin stimulation of thymidine kinase in the human breast cancer cell line T74D

Our laboratory has previously reported that progestins stimulate growth of the human breast cancer cell line T47D. In an attempt to probe further into this stimulation, we are investigating progestin effects of thymidine kinase (EC 2.7.1.21), an enzyme known to be involved in growth regulation. This report relates our finding that progestins stimulate thymidine kinase activity, at physiological progestin concentrations, in a dose-responsive manner. Estradiol-17β also stimulates, but testosterone, hydrocortisone and aldosterone do not. The antiprogestin RU486 inhibits progestin stimulation, but also stimulates on its own. Maximal by 24 h, the progestin stimulation then falls off with time. Experiments with actinomycin D and cycloheximide suggest that the thymidine kinase stimulation depends on new RNA and protein synthesis. These data shed further light on progestin stimulation of the growth of human breast cancer. To our knowledge, this is the first report of progestin stimulation of thymidine kinase in human breast cancer cells.     

高糖对原代培养人肾小球系膜细胞表达MMP-9、TIMP-1的影响

目的了解高糖对原代培养的人肾小球系膜细胞表达MMP-9、TIMP-1和MMP-9/TIMP-1的影响,进一步探讨糖尿病肾病的发病机制。方法取自愿水囊引产的胎儿肾,解剖取肾皮质剪碎,应用肾皮质组织块法合优生选择法对人肾小球系膜细胞进行原代培养。ELISA方法检测MMP-9、TIMP-1的表达变化。结果与正常组相比较,高糖组MMP-9在24h、48h、72h均显著降低（P〈0.01）,TIMP-1在24h、72h可显著升高（P〈0.05）,48h表达降低;MMP-9/TIMP-1的比值在24h、48h、72h均显著降低（P〈0.01）。结论高糖能够降低MMP-9/TIMP-1,与肾小球系膜细胞细胞外基质降解能力降低密切相关。