The role of Nrf2 signaling in parasitic diseases and its therapeutic potential.

In response to invading parasites, one of the principal arms of innate immunity is oxidative stress, caused by reactive oxygen species (ROS). However, oxidative stresses play dual functions in the disease, whereby free radicals promote pathogen removal, but they can also trigger inflammation, resulting in tissue injuries. A growing body of evidence has strongly supported the notion that nuclear factor erythroid 2-related factor 2 (NRF) signaling is one of the main antioxidant pathways to combat this oxidative burst against parasites. Given the important role of NRF2 in oxidative stress, in this review, we investigate the activation mechanism of the NRF2 antioxidant pathway in different parasitic diseases, such as malaria, leishmaniasis, trypanosomiasis, toxoplasmosis, schistosomiasis, entamoebiasis, and trichinosis.

The common bisulfite-conversion-based techniques to analyze DNA methylation in human cancers.

DNA methylation is an important molecular modification that plays a key role in the expression of cancer genes. Evaluation of epigenetic changes, hypomethylation and hypermethylation, in specific genes are applied for cancer diagnosis. Numerous studies have concentrated on describing DNA methylation patterns as biomarkers for cancer diagnosis monitoring and predicting response to cancer therapy. Various techniques for detecting DNA methylation status in cancers are based on sodium bisulfite treatment. According to the application of these methods in research and clinical studies, they have a number of advantages and disadvantages. The current review highlights sodium bisulfite treatment-based techniques, as well as, the advantages, drawbacks, and applications of these methods in the evaluation of human cancers.

The interplay between microRNAs and Nrf2 signaling in human cancers.

MicroRNAs (miRNAs), as a class of nonprotein-coding RNAs, post-transcriptionally regulate the expression of target genes by base pairing to 3'-untranslated regions (3'-UTRs). Nuclear factor E2-related factor 2 (Nrf2) has been identified as a critical component of the antioxidant defense mechanism. Dysregulation is associated with chemoresistance and radioresistance in cancerous cells. MiRNA-mediated regulation of the Nrf2 signaling pathway has been shown to have important implications for the development of various cancers. In this article, we review the roles of miRNAs as regulators of the Nrf2 pathway in different human cancers. Ras-associated binding (Rab) proteins have an essential role regulation of vesicle transport, as well as oncogenic functions in preventing chemotherapy efficacy and cancer development. More importantly, increased evidence indicated that the interaction between miRNAs and Rabs has been determined to play critical roles in cancer therapy. However, the significant limitations in using miRNAs for therapeutic applications include cross-targeting and instability of miRNAs. The detailed aspect of the interaction of miRNAs and Rabs is not clearly understood. In the current review, we highlighted the involvement of these molecules as regulators of the Nrf2 pathway in cancer pathogenesis. Potential methods and several obstacles in developing miRNAs as an anticancer therapy are also mentioned.

In vitro Evaluation of the Potent Antileishmanial Activity of Ferula tabasensis Alone or in Combination with Shark Cartilage Extract Against the Standard Iranian Strain of Leishmania major (MRHO/IR/75/ER).

Background: The available drugs for the treatment of leishmaniasis are highly toxic and extremely expensive, with low efficiency; therefore, the development of effective therapeutic compounds is essential. Objectives: The present study aimed to explore the antileishmanial effects of ethyl acetate extract, methanol extract, and fractions 1-4 (F1-F4) of Ferula tabasensis, alone or in combination with shark cartilage extract (ShCE), on L. major in vitro. Methods: In this study, ethyl acetate, methanol, and n-hexane extracts were extracted from the aerial roots of F. tabasensis by the maceration method. The silica gel column chromatography was used to separate n-hexane extracts at varying polarities (F1-F4 fractions). Subsequently, the effects of extracts and fractions against promastigotes were assessed by the parasite counting method microscopic inhibition test and MTT assay. Besides, their effects on the infected macrophage cells and the number of amastigotes were investigated. Cytotoxicity was evaluated in non-infected J774A.1 macrophage cells. Finally, apoptosis induction of promastigotes, including infected and non-infected macrophages, was evaluated. Results: The results indicated the highly potent activity of F. tabasensis extracts and F1-F4 fractions, alone or in combination with ShCE, against L. major promastigotes and amastigotes in a dose-dependent manner (P < 0.05). The F1 fraction and methanol extract showed markedly higher toxicity compared to the other extracts and fractions, with 50% inhibitory concentrations (IC50/72h) of 2.4 ± 0.29 and 2.9 ± 0.55 µg/mL against promastigotes and 1.79 ± 0.27 µg/mL and 1.39 ± 0.27 µg/mL against amastigotes (P < 0.001). Moreover, they had a high selectivity index (SI) due to the low toxicity of macrophages (P < 0.0001). The results of flow cytometry indicated that the percentages of apoptotic promastigote cells in contact with IC50 concentrations of F1 and methanol extract alone after 72 h were 43.83 and 43.93%, as well as 78.4%, and 65.45% for their combination with ShCE, respectively.Also, apoptosis of infected macrophages induced by F1 and methanol extracts was estimated at 68.5% and 83.7%, respectively. Conclusions: In this study, the F1 fraction and methanol extract of F. tabasensis showed potent efficacy against L. major, associated with low toxicity and apoptosis induction. Therefore, they can be promising therapeutic candidates in future animal and even human studies.

A novel compound heterozygous of ß-thalassemia with HbG-Coushatta: case report of Iran.

A 30-year-old male couple from Ardabil city, Iran, were admitted for premarital screening. An abnormal band in HbS/D regions with high levels of HbF and HbA 2 led us to suspect the possibility of a compound heterozygous state of ß-thalassemia in our affected proband. Therefore, beta globin chain sequencing of proband discovered a heterozygote combination of the Hb G-Coushatta [b22 (B4) Glu>Ala, HBB: c.68A>C) with HBB: IVS-II-1 (G>A) mutation as a compound heterozygote.

An update of Nrf2 activators and inhibitors in cancer prevention/promotion.

NF-E2-related factor 2 (Nrf2) protein is a basic-region leucine zipper transcription factor that defends against endogenous or exogenous stressors. By inducing several cytoprotective and detoxifying gene expressions, Nrf2 can increase the sensitivity of the cells to oxidants and electrophiles. Transient Nrf2 activation, by its specific activators, has protective roles against carcinogenesis and cancer development. However, permanent activation of Nrf2 promotes various cancer properties, comprising malignant progression, chemo/radio resistance, and poor patient prognosis. Taken together, these findings suggest that reaching an optimal balance between paradoxical functions of Nrf2 in malignancy may render a selective improvement to identify therapeutic strategies in cancer treatment. In this review, we describe lately discovered Nrf2 inducers and inhibitors, and their chemopreventive and/or anticancer activities.

Cellular immunotherapy in gastric cancer: adoptive cell therapy and dendritic cell-based vaccination.

Gastric cancer (GC) is one of the most frequently diagnosed malignancies. Recent studies have highlighted cellular immunotherapy (CI) as a promising approach for treating this disease. Among the CI-based approaches, adoptive cell therapy and dendritic cell-based vaccination are commonly studied in preclinical and clinical trials. Here we review the current evidence on the potentiality of CI in treating GC, the targets for adoptive cell therapy, ongoing clinical trials, constraints and the future outlook. The results suggest that there is a need to identify novel biomarkers that predict which GC patients will most likely respond to these approaches. Also, CI plus chemotherapy or immune checkpoint inhibitors can improve the survival of patients with late-stage GC. Therefore, this approach can be promising for treating these patients.

Reduced Levels of miR-28 and miR-200a Act as Predictor Biomarkers of Aggressive Clinicopathological Characteristics in Gastric Cancer Patients.

BACKGROUND: MicroRNAs (miRNAs) play critical roles in different pathological processes including cancer development and progression. To find novel molecular diagnostic and prognostic markers and promising therapeutic tools for gastric cancer (GC), we aimed to investigate the relationship of the expression levels of miR-28-5p or miR-200a-3p with the clinicopathological criteria and to explore their impacts on the progression of human GC. MATERIALS AND METHODS: Quantitative RT-PCR was performed to analyze miR-28 and miR-200a expression in 60 GC and 60 non-GC tissue samples. RESULT: Our results revealed that the expressions of miR-200a and miR-28 were significantly downregulated in GC in comparison with non- GC tissues. Tumors with low miR-28 expression had larger tumor size, more advanced histological grade, and a higher incidence of lymph node and distal metastasis than the tumors with high miR-28 expressions. Furthermore, receiver operating characteristic (ROC) analyses demonstrate that the expression of miR-28 is a predictive biomarker allows predicting the histological grade, tumor size, and occurrence of nodal and distal metastases. We also found a significant inverse association between miR-200a expression and the rate of lymph node metastasis (p = 0.010, r = -0.334). CONCLUSION: Our findings suggest that the miR-28 and miR-200a have tumor-suppressor functions and may be considered as potential biomarkers for gastric cancer diagnosis and prognosis.

Biomimetic synthesis of silver nanoparticles using Matricaria chamomilla extract and their potential anticancer activity against human lung cancer cells.

Herbs having various natural substances can be utilized for the biosynthesis of Silver nanoparticles (AgNPs) and act as a stable, reliable and biocompatible alternative instead of the current physical and chemical approaches. It has been reported that Matricaria chamomilla possesses unique properties, especially anti-cancerous effects. The objective of the current work was to assess the chemical characteristics and anticancer effects of biosynthesized AgNPs applying aqueous extracts of M. chamomilla against A549 lung cancer cells. UV-visible spectrum showed the maximum absorption of the biosynthesized AgNPs at 430 nm. The crystalline structure of biosynthesized AgNPs in optimal conditions was confirmed by XRD. Moreover, the presence of Ag as the ingredient element was exhibited via EDX analysis. FT-IR results also verified the AgNPs synthesis using a plant extract. The spherical shapes of the AgNPs with an average diameter size around 45.12 nm and a zeta potential value of -34 mV were characterized using DLS, and confirmed through FE-SEM and TEM. In vitro cytotoxicity assay using MTT revealed that the biosynthesized AgNPs exhibited a dose- and time- dependent cytotoxic effect against A549 lung cancer cells. Moreover, the apoptotic effects of the AgNPs were demonstrated using DAPI staining, real-time PCR and flow cytometry. According to these findings, using M. chamomilla in combination with AgNPs via green-synthesis approach may be an efficient strategy for effective treatment of lung cancer.

Nrf2/P-glycoprotein axis is associated with clinicopathological characteristics in colorectal cancer.

Colorectal cancer (CRC) is the fourth leading cause of cancer-related death worldwide. Activation of ABCB1 gene and its main product, P-glycoprotein, is the common reason for chemoresistance. The nuclear factor-erythroid 2-related factor2 (Nrf2) is directly regulated by Kelch like ECH-associated protein1 (Keap1). In addition, Nrf2 is a key transcriptional factor that regulates efflux transporters, including P-gp. The aim of this study was to investigate the expression levels of Nrf2, Keap1 and ABCB1 in the biopsy samples and their association with clinicopathological features in CRC patients. Both mRNA and protein expression levels were measured by Real-time PCR and immunohistochemistry (IHC), respectively, in biopsies from colonoscopy in 65 CRC patients compared to those in 65 non-CRC individuals. While expression levels of Nrf2 and ABCB1 (P-gp) were markedly higher in both mRNA and protein levels in CRC biopsies (p < 0.01), Keap1 expression level was significantly lower in these samples (p < 0.05). Positive correlations between Nrf2 expression level and tumor size (p = 0.003), lymph node (p = 0.038), distant metastasis (p = 0.008), and smoking status (p = 0.02) were observed. However, P-gp expression was associated only with patient age and smoking status. In addition, there was a positive correlation between protein levels of Nrf2 and P-gp, in both CRC (r = 0.617, p < 0.001) and non-CRC tissues (r = 0.930, p < 0.001). In conclusion, over-expression of Nrf2 and ABCB1/P-gp, as well as down-regulation of mRNA expression level of Keap1 in CRC patients denotes the role of Keap1/Nrf2/ABCB1 axis in CRC progression and chemoresistance. Our data suggest that therapeutic inhibition of Nrf2/ABCB1 signaling can be considered as a novel strategy to improve the efficacy of chemotherapeutics against CRC.

Nrf2 overexpression is associated with P-glycoprotein upregulation in gastric cancer.

The efficacy of chemotherapeutic agents remains very poor in gastric cancer (GC) patients due to the development of multidrug resistance (MDR) phenotype. The nuclear factor erythroid 2-related factor 2 (Nrf2), is a pivotal transcriptional factor that regulates phase II detoxifying enzymes, antioxidants and efflux transporters including P-glycoprotein (P-gp). The aim of this study was to investigate the association of Nrf2 and P-gp and their correlations with clinicopathological criteria in GC patients.Nrf2 and MDR1/P-gp expressions in both mRNA and protein levels were examined by real-time PCR and immunohistochemical staining (IHC) respectively, in endoscopic biopsy samples from60 GC patients compared with those expressions in non-GC individuals. Our results from IHC examinations revealed that Nrf2 expression in GC patients (46.7%) is markedly higher than that in non-GC individuals (11.7%) (p<0.001, Mann-Whitney test) which was confirmed by real-time PCR in mRNA levels. Induction of P-gp as a drug efflux pump, was associated with Nrf2 overexpression in these samples (r=0.55, p<0.001). There was also a strong correlation between Nrf2 overexpression and tumor size, histological grade, lymph node and distant metastasis while P-gp upregulation was shown to be associated only with the histological grade and tumor size (Chi-square, all p<0.05). Our results suggest that therapeutic inhibition of Nrf2 expression can improve the efficacy of chemotherapeutic agents for GC patients by down regulation of P-gp expression.

Comparison of genome-wide analysis techniques to DNA methylation analysis in human cancer.

DNA methylation was the first epigenetic modification to be detected in human cancers with specific relation to aberrant gene expression. Herein, DNA methylation analysis explains how epigenetic patterns affect gene expression level. Hypermethylation at tumor suppressor gene loci leads to increased tumorigenesis due to tumor suppressor gene silencing, whereas global hypomethylation of CpG islands (CGIs) is followed by genomic instability and aberrant activation of multiple oncogenes. Therefore, characterization of the genes which silenced or activated epigenetically in human tumor cells can improve our understanding of cancer biology. Different genome-wide methodologies are applied to evaluate methylation status. Various commonly conducted techniques for this evaluation are reviewed in this paper. We provided comparative description of the procedures, advantages, and drawbacks of genome-wide DNA methylation analysis methods and biological applications, to give information on selecting the appropriate method for different methylation studies.

The role of Nrf2-Keap1 axis in colorectal cancer, progression, and chemoresistance.

Colorectal cancer is the third common cancer after lung and genital cancers worldwide with more than 1.2 million new cases diagnosed annually. Although extensive progress has been made in the treatment of colorectal cancer, finding novel targets for early diagnosis and effective treatment of these patients is an urgent need. Nuclear factor-erythroid 2-kelch-like ECH-associated protein 1 signaling pathway plays a key role in protecting cells from the damage of intracellular oxidative stress and extracellular oxidizing agents. Nuclear factor-erythroid 2 is a transcription factor that creates intracellular redox homeostasis via transcriptional activity and interaction with kelch-like ECH-associated protein 1. Furthermore, it contributes to survival and chemoresistance of colorectal cancer cells which is mediated by overexpression of cytoprotective and multidrug resistance genes. In this review, the dual role of nuclear factor-erythroid 2 signaling in induction of colorectal cancer cell survival and death as well as the possibility of targeting nuclear factor-erythroid 2-kelch-like ECH-associated protein 1 axis as an advanced strategy in prevention and effective treatment of colorectal cancer patients have been discussed.

Contradictory roles of Nrf2/Keap1 signaling pathway in cancer prevention/promotion and chemoresistance.

NF-E2-related factor 2 (Nrf2) protein is a cytosolic transcription factor that regulates antioxidant and stress-related enzymes. Kelch-like ECH-associated protein 1 (Keap1) binds Nrf2 and accelerates ubiquitination and proteasome-dependent degradation of Nrf2. Nrf2 modifies the sensitivity of the cell environment to electrophiles and oxidants by inducing the transcriptional activation of more than 100 detoxification and cytoprotective genes. Prior investigations have found documentary evidence indicating that temporary activation of Nrf2 by pharmaceutical inducers plays a protective role against cancer initiation in normal cells. The impact of Nrf2/Keap1 pathway in development of tumorigenesis and drug resistance has also been well documented. Inhibition of the permanent Nrf2 activation, especially in combination with chemotherapeutics against cancer, may be considered as an important strategy to inhibit tumor growth and overcome chemoresistance. Here, we review the importance of Nrf2-keap1 pathway in the prevention or promotion of cancer, and resistance mechanisms to chemotherapeutic agents.

Hydatid Cyst Protoscolices Induce Cell Death in WEHI-164 Fibrosarcoma Cells and Inhibit the Proliferation of Baby Hamster Kidney Fibroblasts In Vitro.

Both in vitro and in vivo models have demonstrated that some parasites can interfere with tumor cell growth. The present study investigates the anticancer activity of hydatid cyst protoscolices on WEHI-164 fibrosarcoma cells and baby hamster kidney (BHK) fibroblast cells in vitro. Those above two cell types were treated with live hydatid cyst protoscolices or left untreated for control groups. After 48 h, lactate dehydrogenase (LDH) and cell counts were assayed for both treated cells and control groups. Following treatment with hydatid cyst protoscolices, cell proliferation of both cell types was inhibited, and lysis of fibrosarcoma cells increased. Based on these results, it appears that hydatid cyst protoscolices have strong anticancer activity, and additional studies are needed to further clarify the mechanisms of this activity.