Propoxur enhances MMP-2 expression and the corresponding invasion of human breast cancer cells via the ERK/Nrf2 signaling pathway

Carbamate compounds induced toxic effects by affecting Nrf2 signaling pathways

Carbamate (CBs) is a class of insecticides which is being known as an important cause of intentional or accidental poisoning. CBs, cause carbamylation of acetylcholinesterase at neuronal synapses and neuromuscular junction. Exposure to CBs through skin contact, inhalation, or ingestion can result in significant cholinergic toxicity. This is due to the elevation of acetylcholine levels at ganglionic synapses found in both the sympathetic and parasympathetic nervous systems, as well as muscarinic receptors located in target organs of the parasympathetic nervous system, nicotinic receptors situated in skeletal muscle tissue, and the central nervous system. The association between human illnesses and environmental exposures to CBs have been extensively studied in several studies. Although CBs-triggered toxicity leads to overproduction of reactive oxygen species (ROS), the detailed association between the toxicity under CBs exposure and NFE2-related factor 2 (Nrf2) signaling pathways has not been completely clarified. In this review we aimed to summarize the latest findings on the functional interrelationship between carbamates compounds and Nrf2 signaling.

Pesticides and Bladder Cancer: Mechanisms Leading to Anti-Cancer Drug Chemoresistance and New Chemosensitization Strategies

Multiple risk factors have been associated with bladder cancer. This review focuses on pesticide exposure, as it is not currently known whether agricultural products have a direct or indirect effect on bladder cancer, despite recent reports demonstrating a strong correlation. While it is known that pesticide exposure is associated with an increased risk of bladder cancer in humans and dogs, the mechanism(s) by which specific pesticides cause bladder cancer initiation or progression is unknown. In this narrative review, we discuss what is currently known about pesticide exposure and the link to bladder cancer. This review highlights multiple pathways modulated by pesticide exposure with direct links to bladder cancer oncogenesis/metastasis (MMP-2, TGF-β, STAT3) and chemoresistance (drug efflux, DNA repair, and apoptosis resistance) and potential therapeutic tactics to counter these pesticide-induced affects.

Black tea bioactive phytoconstituents realign NRF2 for anticancer activity in lung adenocarcinoma

Constitutive activation of nuclear factor erythroid 2-related factor 2 (NRF2) is pivotal in bestowing therapy resistance in cancer cells. Several phytochemicals have been reported with the potential of modulating NRF2. Therefore, it was hypothesized that NRF2-deregulated chemoresistance in lung adenocarcinoma (LUAD) may be counteracted by theaflavin-rich black tea (BT). A non-responsive LUAD cell line, A549, was the best sensitized towards cisplatin upon pre-treatment with BT. BT-mediated NRF2 reorientation was observed to be dependent on concentration and duration of treatment as well as on the mutational profile of NRF2 in A549 cells. Transient exposure of low-concentration BT hormetically downregulated NRF2, its downstream antioxidants, and drug transporter. BT also influenced the Kelch-like ECH-associated protein (KEAP1)-dependent cullin 3 (Cul3) and KEAP-1-independent signaling through epidermal growth factor receptor (EGFR) - rat sarcoma virus (RAS) - rapidly accelerated fibrosarcoma (RAF) - extracellular signal-regulated kinase 1/2 (ERK) - matrix metalloproteinase (MMP)-2 and MMP-9. The realignment of NRF2 in KEAP1-suppressed A549 cells enhanced the chemotherapeutic outcome. But a higher concentration of the same BT surprisingly upregulated NRF2 and its transcriptional targets with a subsequent decrease in the NRF2-regulatory machinery in NCI-H23 cells (a KEAP1-overexpressed LUAD cell line), ultimately resulting in a better anticancer response. The BT-mediated bidirectional NRF2 modulation was reconfirmed upon comparison with the action of a pharmacological NRF2 inhibitor, ML-385, in A549 and a known NRF2 activator, tertiary-butylhydroquinone, in NCI-H23 respectively. BT-mediated regulation of NRF2-KEAP1 and their upstream networks (EGFR/RAS/RAF/ERK) sufficed as a better anticancer agent than synthetic NRF2 modulators. Therefore, BT may be indicated as a potent multi-modal small molecule for increasing drug responsiveness in LUAD cells by maintaining NRF2/KEAP1 axis at an optimum level.

The Biology and Function of Tissue Inhibitor of Metalloproteinase 2 in the Lungs

Tissue inhibitors of matrix metalloproteinases (TIMP) are a family of four endogenous proteins that primarily function to inhibit the activities of proteases such as the matrix metalloproteinases (MMP). Altered MMP/TIMP ratios are frequently observed in several human diseases. During aging and disease progression, the extracellular matrix (ECM) undergoes structural changes in which elastin and collagens serve an essential role. MMPs and TIMPs significantly influence the ECM. Classically, elevated levels of TIMPs are suggested to result in ECM accumulation leading to fibrosis, whereas loss of TIMP responses leads to enhanced matrix proteolysis. Here, we outline the known roles of the most abundant TIMP, TIMP2, in pulmonary diseases but also discuss future perspectives in TIMP2 research that could impact the lungs. TIMP2 directly inhibits MMPs, in particular MMP2, but TIMP2 is also required for the activation of MMP2 through its interaction with MMP14. The protease and antiprotease imbalance of MMPs and TIMPs are extensively studied in diseases but recent discoveries suggest that TIMPs, specifically, TIMP2 could play other roles in aging and inflammation processes.

Clinical role of MiRNA 29a and MiRNA 335 on breast cancer management: their relevance to MMP2 protein level

BACKGROUND

Circulating miRNAs are novel biomarkers, authors aimed to investigate the expression level of miR-29a and miR-335 and their relevance to CEA, CA15.3, and matrix metalloproteinase-2 (MMP2).

MATERIALS AND METHODS

Breast cancer (BC) patients (n = 44), benign breast lesion patients (n = 25), and healthy individuals (n = 19) were enrolled for detection of miRNA expression levels, MMP2 and biochemical markers using quantitative polymerase chain reaction (PCR) and ELISA, respectively.

RESULTS

Expression of miR-29a and miR-335 were significantly decreased in breast patients as compared to healthy individuals, while biochemical markers were high in BC patients as compared to the other two groups. The diagnostic efficacy for miR-29a, miR-335, and MMP2 were superior to both CEA and CA 15.3 for early detection of BC patients.

CONCLUSIONS

Detection of the miR-29a and miR335 expression levels in serum samples are significant promising biomarkers for BC diagnosis.

Abnormal phenotype of Nrf2 is associated with poor prognosis through hypoxic/VEGF-A-Rap1b/VEGFR2 pathway in gastric cancer

Metastasis is the major cause of death in gastric cancer patients and altered expression of Nrf2 is associated with cancer development. This study assessed Nrf2 and HO-1 expression and hypoxia-induced Nrf2 expression in the promotion of metastatic potential of gastric cancer cells, the relationship of Rap1b and Nrf2 was also discussed. Nrf2 and HO-1 expression were significantly associated with clinicopathological characteristic and were independent prognostic predictors in gastric cancer patients. Hypoxia up-regulated the expression of Nrf2, HO-1 and HIF-1α, whereas knockdown of Nrf2 inhibited cell invasion capacity and reduced the expression of Nrf2, HO-1 and HIF-1α. Patients in the Rap1b (+) Nrf2 (+) group had worst overall survival compared with those from other groups. Knockdown of Rap1b and Nrf2 significantly inhibited cell invasion capacity in the common group compared with the other groups. Hypoxia or VEGF-A facilitated the nuclear translocation of Nrf2 through Rap1b or VEGFR2. Hypoxia or VEGF-A did not induce the phosphorylation of P-Erk1/2 and P-Akt after knockdown of Rap1b or VEGFR2. Hypoxia promoted the gastric cancer malignant behavior through the upregulation of Rap1b and Nrf2. Hypoxia/VEGF-A-Rap1b/VEGFR2 facilitated the nuclear translocation of Nrf2. Targeting Rap1b and Nrf2 may be a novel therapeutic strategy for gastric cancer.

Muscone suppresses gastric cancer via regulation of miRNA-145

This study aims to determine the effects and mechanism of action of muscone on the biological activity of the gastric cancer cell lines SGC-7901 and MGC-803 (proliferation, apoptosis, invasion, and migration) in vitro. An optimal muscone concentration was determined using MTT and cell apoptosis tests. The SGC-7901 and MGC-803 cells were divided into five groups: normal control, muscone, miRNA, muscone + miRNA, and muscone + miRNA inhibitor. Cell proliferation rate, apoptosis rate, cell cycle phase distribution, number of invading cells, and wound healing rate were compared among the five groups using MTT, flow cytometry, transwell, and wound healing assays. Relative expression levels of the proteins PI3K, AKT, P21, c-Myc, MMP-2, and MMP-9 were measured by Western blot. Compared with the control group, the groups treated with muscone and miRNA showed significantly lower cell proliferation rate, number of invading cells, and wound healing rate (p < .05 for all), but significantly higher rates of cell apoptosis rate and numbers of cells in the G1 phase (p < .05 for all). These groups also showed significantly lower expression of the proteins PI3K, AKT, c-Myc, MMP-2, and MMP-9 but significantly increased expression of the protein P21 (p < .05). Transfecting muscone-treated SGC-7901 and MGC-803 cells with miRNA-145 inhibitor resulted in a significant recovery of biological activity (p < .05). Muscone suppresses the biological activity of SGC-7901 and MGC-803 gastric cancer cells in vitro via regulation of miRNA-145.

Role of ALDH1A1 and HTRA2 expression in CCL2/CCR2-mediated breast cancer cell growth and invasion

Chemokines mediate immune cell trafficking during tissue development, wound healing and infection. The chemokine CCL2 is best known to regulate macrophage recruitment during wound healing, infection and inflammatory diseases. While the importance of CCL2/CCR2 signaling in macrophages during cancer progression is well documented, we recently showed that CCL2-mediated breast cancer progression depends on CCR2 expression in carcinoma cells. Using 3D Matrigel: Collagen cultures of SUM225 and DCIS.com breast cancer cells, this study characterized the mechanisms of CCL2/CCR2 signaling in cell growth and invasion. SUM225 cells, which expressed lower levels of CCR2 than DCIS.com cells, formed symmetrical spheroids in Matrigel: Collagen, and were not responsive to CCL2 treatment. DCIS.com cells formed asymmetric cell clusters in Matrigel: Collagen. CCL2 treatment increased growth, decreased expression of E-cadherin and increased TWIST1 expression. CCR2 overexpression in SUM225 cells increased responsiveness to CCL2 treatment, enhancing growth and invasion. These phenotypes corresponded to increased expression of Aldehyde Dehydrogenase 1A1 (ALDH1A1) and decreased expression of the mitochondrial serine protease HTRA2. CCR2 deficiency in DCIS.com cells inhibited CCL2-mediated growth and invasion, corresponding to decreased ALDH1A1 expression and increased HTRA2 expression. ALDH1A1 and HTRA2 expression were modulated in CCR2-deficient and CCR2-overexpressing cell lines. We found that ALDH1A1 and HTRA2 regulates CCR2-mediated breast cancer cell growth and cellular invasion in a CCL2/CCR2 context-dependent manner. These data provide novel insight on the mechanisms of chemokine signaling in breast cancer cell growth and invasion, with important implications on targeted therapeutics for anti-cancer treatment.

This article has an associated First Person interview with the first author of the paper.

Summary: Chemokines are known to regulate immune cell recruitment during inflammation. This report characterizes novel molecular mechanisms through which CCL2/CCR2 chemokine signaling in breast cancer cells regulates growth and invasion.

Silence of Stomatin-Like Protein 2 Represses Migration and Invasion Ability of Human Liver Cancer Cells via Inhibiting the Nuclear Factor Kappa B (NF-κB) Pathway

BACKGROUND Liver cancer is the third leading cause of tumor-related deaths worldwide. Stomatin-like protein 2 (STOML2) is obviously upregulated in various tumors. In this study, we explored the potential roles and mechanisms of si-STOML2 in the migration and invasion of human hepatoma LM3 cells. MATERIAL AND METHODS The expression levels of STOML2 in tissues and cells were separately analyzed with quantitative real-time PCR (qRT-PCR) and Western blotting. The viability, migration, and invasion of cells were assessed by cell counting kit-8 (CCK-8), wound healing, and transwell analysis, respectively. The mRNA and protein levels of various factors were separately measured using qRT-PCR and Western blotting. Correlation analysis between the expression of STOML2 and the clinicopathological features of liver cancer patients was evaluated using the chi-square test. RESULTS Surprisingly, our results showed that STOML2 was upregulated in liver cancer tissue and cells, and this upregulation was linked to tumor size, histologic grade, and metastasis, but was not associated with sex, age, or TNM stage. The knockdown of STOML2 significantly repressed the viability, migration, and invasion of LM3 cells. We also observed that silencing STOML2 markedly downregulated the expression levels of matrix metalloproteinase-2 (MMP-2), MMP-9, metastatic tumor antigen 1 (MTA1), and nuclear factor kappa B (NF-κB), and upregulated levels of E-cadherin, tissue inhibitor of metalloproteinases 2 (TIMP2), and the inhibitor of kappa B (IκB). CONCLUSIONS STOML2 has a vital role in the progression of liver cancer. STOML2 silencing in LM3 cells obviously repressed the abilities of migration and invasion via suppressing the NF-κB pathway.

miR-29b negatively regulates MMP2 to impact gastric cancer development by suppress gastric cancer cell migration and tumor growth

MicroRNAs (miRNAs) are important regulators and associated with the development of many different types of cancer, including gastric cancer. However, their pathophysiologic role and their relevance to tumorigenesis, invasion and metastasis are still unknown. In our current study, we performed microRNA array and found that 28 of miRNAs were differentially expressed in INF type of gastric cancer. Among 28 miRNAs, miR-29b was one of the most significantly down-regulated miRNA. Further bioinformatics analysis showed that MMP2 was a potential target of miR-29b. Interestingly, luciferase analysis showed that miR-29b negatively regulates MMP2 by binding with the miRNA response element (MRE) on the 3'UTR of MMP2. In addition, overexpression of miR-29b significantly decreased the mRNA and protein level of MMP2 and the activity of MMP2 to suppress gastric cancer cell migration. Moreover, lentivirus mediated overexpression of miR-29b dramatically suppressed the ability of BGC823 cells to form colonies in vitro and their ability to develop tumor in vivo in nude mice. Finally, our qPCR and western blot analysis showed that miR-29b was significantly reduced in clinical gastric cancer tissue, whereas MMP2 protein was significantly up-regulated, suggesting that this aberrant down-regulation of miR-29b might be associated with the abnormal regulation of MMP2 and the development of gastric cancer. Significant apparent was also found between miR-29b expression and TNM staging, lymph node status, tumor differentiation and Ming classification. Together, our data suggest an important regulatory role of miR-29b in the development of gastric cancer. Thus, miR-29b and MMP2 might be important diagnostic or therapeutic targets for human tumor diseases.

Genistein inhibits invasion and migration of colon cancer cells by recovering WIF1 expression

Colon cancer is characterized by invasion and migration. DNA methylation of CpG islands in tumor suppressor genes is considered to be an epigenetic mechanism underlying cancer development. Epigenetic silencing of a gene may be reversed by drugs, including genistein. The present study aimed to determine the effect of genistein on Wnt inhibitory factor 1 (WIF1) and invasion, and migration of colon cancer cells. The viability of HT29 colon cancer cells was suppressed by genistein in a dose dependent manner. Following 72 h of treatment with 10, 20 and 60 µmol/l genistein, increased demethylation of WIF1 was induced in a dose‑dependent manner. Additionally, the invasive/migratory abilities of cells treated with genistein decreased in a dose‑dependent manner. Reverse transcription‑quantitative polymerase chain reaction and western blot analyses were performed to identify the mRNA and protein expression levels of invasion/migration‑associated factors. Following treatment with genistein, matrix metalloproteinase (MMP) 2 and MMP9 expression levels decreased, whereas the expression of metalloproteinase inhibitor 1 and E‑cadherin increased significantly. In addition, the expression levels of proto‑oncogene Wnt‑1 (Wnt‑1)/β‑catenin pathway‑associated factors, β‑catenin, c‑Myc proto‑oncogene protein and cyclin D1 decreased in a dose‑dependent manner following treatment with genistein. The invasive/migratory abilities of cells transfected with WIF1‑small interfering (si) RNA, and those transfected with WIF1‑siRNA and treated with genistein, increased notably compared with the control group. The present study demonstrated that genistein was able to inhibit the cell invasion and migration of colon cancer cells by inducing demethylation, and recovering the activity of WIF1 by altering the expression of invasion‑associated factors, and components of the Wnt signaling pathway.