Effective Targeting of Raf-1 and Its Associated Autophagy by Novel Extracted Peptide for Treating Breast Cancer Cells

Breast cancer is one of the most common causes of death in women worldwide and has harmful influence on their psychological state during therapy. Multikinase inhibitors have become effective drugs for treating a variety of cancer diseases such as breast cancer. A purified short peptide (H-P) was isolated from the natural honey and tested for its potential regulatory role in breast cancer cells compared with the effectiveness of the anticancer drug, Sorafenib (SOR), using MCF-7, EFM-19, and MCF-10A cell lines. Furthermore, we investigated the direct connection between Raf-1 activation and cellular autophagy as potential targets of SOR and H-P extract using RNA interference. Interestingly, the treatment with H-P showed competitive regulation of phosphorylated Raf-1, MEK1/2, and matched autophagy-related LC3B without any detectable toxic effects in the non-tumorigenic epithelial cells. Unlike SOR, the regulation of Raf-1 protein and autophagic machinery by the novel H-P extract showed neglected levels of the released proinflammatory cytokine. This regulation of cytokine secretion by H-P resulted in decreasing the expression level of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) in treated cells. Moreover, the transfection of MCF-7 cells with small interference RNA (siRNA) antagonist Raf-1 expression markedly reduced the expression of LC3B, while it increased the expression of NF-kB1 and NF-kB2, indicating the potential cross-link between Raf-1, autophagy, and NF-kB effector. Collectively, these findings suggest that H-P-mediated Raf-1, MEK1/2, LC3B, and NF-kB provide a novel and efficacious multikinase inhibitor for treating breast cancer without detectable cytotoxic effects.

The Mechanical Autophagy as a Part of Cellular Immunity; Facts and Features in Treating the Medical Disorders

Autophagy is a cellular housekeeping process that incorporates lysosomal-degradation to maintain cell survival and energy sources. In recent decades, the role of autophagy has implicated in the initiation and development of many diseases that affect humanity. Among these diseases are autoimmune diseases and neurodegenerative diseases, which connected with the lacking autophagy. Other diseases are connected with the increasing levels of autophagy such as cancers and infectious diseases. Therefore, controlling autophagy with sufficient regulators could represent an effective strategy to overcome such diseases. Interestingly, targeting autophagy can also provide a sufficient method to combat the current epidemic caused by the ongoing coronavirus. In this review, we aim to highlight the physiological function of the autophagic process to understand the circumstances surrounding its role in the cellular immunity associated with the development of human diseases.

Methylomic Changes of Autophagy-Related Genes by Legionella Effector Lpg2936 in Infected Macrophages

Legionella pneumophila (L. pneumophila) is a Gram-negative bacterium that infects the human respiratory tract causing Legionnaires' disease, a severe form of pneumonia. Recently, rising evidence indicated the ability of Legionella to regulate host defense via its type 4 secretion system including hundreds of effectors that promote intracellular bacterial replication. The host defense against such invaders includes autophagic machinery that is responsible for degradation events of invading pathogens and recycling of cell components. The interplay between host autophagy and Legionella infection has been reported, indicating the role of bacterial effectors in the regulation of autophagy during intracellular replication. Here, we investigated the potential impact of Legionella effector Lpg2936 in the regulation of host autophagy and its role in bacterial replication using mice-derived macrophages and human lung epithelial cells (A549 cells). First, monitoring of autophagic flux following infection revealed a marked reduction of Atg7 and LC3B expression profile and low accumulation levels of autophagy-related LC3-I, LC3-II, and the Atg12-Atg5 protein complex. A novel methyladenine alteration was observed due to irreversible changes of GATC motif to G(6 mA) TC in the promoter region of Atg7 and LC3B indicated by cleaved genomic-DNA using the N6 methyladenine-sensitive restriction enzyme DpnI. Interestingly, RNA interference (RNAi) of Lpg2936 in infected macrophages showed dramatic inhibition of bacterial replication by restoring the expression of autophagy-related proteins. This is accompanied by low production levels of bacterial-associated pro-inflammatory cytokines. Furthermore, a constructed Lpg2936 segment in the GFP expression vector was translocated in the host nucleus and successfully induced methyladenine changes in Atg7 and LC3B promoter region and subsequently regulated autophagy in A549 cells independent of infection. Finally, treatment with methylation inhibitors 5-AZA and (2)-Epigallocatechin-3-gallate (EGCG) was able to restore autophagy-related gene expression and to disrupt bacterial replication in infected macrophages. This cumulative evidence indicates the methylation effect of Legionella effector Lpg2936 on the host autophagy-related molecules Atg7 and LC3B and subsequent reduction in the expression levels of autophagy effectors during intracellular replication of L. pneumophila.

Selective Regulation of B-Raf Dependent K-Ras/Mitogen-Activated Protein by Natural Occurring Multi-kinase Inhibitors in Cancer Cells

Introduction: Cancer is one of the most difficult challenges faced by humanity due to its many associated issues, such as inability to prevent diseases, treatment safety, and high mortality rate. In cancer, a variety of cellular signaling is activated to ensure malignancy transformation, angiogenesis and metastasis. The most efficient signaling pathway in cancer is mitogen-activated protein kinase (MAPK), which controls malignancy and regulates apoptosis.

Methods: Four different flavonoid glycosides have been isolated from Pulicaria jaubertii using the phytochemical characterization of hydro-methanol extract. The purified glycosides (PJs) were investigated for their potential repression of cancer development using human lung epithelial cells and hepatocellular carcinoma (HCC) and compared with Sorafenib (SOR), the standard systemic drug for HCC. In PJ-treated cells, the expression profile of K-Ras, B-Raf, and P53 were detected using qRT-PCR, flow cytometry, confocal microscopy and western blot. Steady-state mRNA and levels of transforming growth factor-beta (TGF-β) and interleukin 8 (IL-8) were monitored in the fluids media at different time points following treatment.

Results: Our results showed that the qurictine glycosides (PJ-1 and PJ-9) selectively inhibited the mutant K-Ras/B-Raf proteins expression and interaction in both cancer cells; while SOR showed obvious depletion of total Raf-1 protein in cancer cells and normal cells as well. Interestingly, the combination of PJ-1 or PJ-9 with SOR exhibited restoring cell viability of normal cells via controlling Raf-1 and P53 genes expression. Further, these identified PJ agents significantly adjusted the levels of TGF-β and IL-8 in cancer treated cells accompanied by restoring the activation of P53 expression. These findings were confirmed by docking analysis of PJs ligand and the crystal structure of K-Ras, B-Raf, and ERK transcription factor.

Conclusion: The current data provide novel and natural multi-kinase inhibitors with competitive regulation of the mutant proteins; K-Ras and B-Raf and sustained MAPK signaling without any detectable toxic effect in normal cells.

Identification of Novel and Efficacious Chemical Compounds that Disturb Influenza A Virus Entry in vitro

Influenza A virus is a negative RNA stranded virus of the family Orthomyxoviridae, and represents a major public health threat, compounding existing disease conditions. Influenza A virus replicates rapidly within its host and the segmented nature of its genome facilitates re-assortment, whereby whole genes are exchanged between influenza virus subtypes during replication. Antiviral medications are important pharmacological tools in influenza virus prophylaxis and therapy. However, the use of currently available antiviral is impeded by sometimes high levels of resistance in circulating virus strains. Here, we identified novel anti-influenza compounds through screening of chemical compounds synthesized de novo on human lung epithelial cells. Computational and experimental screening of extensive and water soluble compounds identified novel influenza virus inhibitors that can reduce influenza virus infection without detectable toxic effects on host cells. Interestingly, the indicated active compounds inhibit viral replication most likely via interaction with cell receptors and disturb influenza virus entry into host cells. Collectively, screening of new synthesis chemical compounds on influenza A virus replication provides a novel and efficacious anti-influenza compounds that can inhibit viral replication via disturbing virus entry and indicates that these compounds are attractive candidates for evaluation as potential anti-influenza drugs.

Single nucleotide polymorphisms of interleukins associated with hepatitis C virus infection in Egypt

INTRODUCTION

Hepatitis C is a liver disease caused by the hepatitis C virus (HCV). It can cause both acute and chronic hepatitis infection. Based on secretion of required cytokines upon infection, HCV can improve its own RNA and successfully complete the replication cycle. Importantly, single nucleotide polymorphisms (SNPs) are the most common type of genetic variation and have been found to play a critical role in modulation of cellular cytokine production and interaction.

METHODOLOGY

A total of 100 blood samples were obtained from HCV patients, and 120 samples were obtained from healthy individuals who served as controls. SNPs of interleukin-10/592 (IL-10/592) and IL-4/589 were investigated for possible connection with HCV infection. Relative expression of IL-4, IL-6, and IL-10 were detected using real-time polymerase chain reaction and enzyme-linked immunosorbent assay.

RESULTS

The polymorphisms of IL-10 revealed a high rate of mutant genotype CC within the location IL-10/592 in HCV patients and controls, which resulted in low secretion of IL-10. Interestingly, the findings here demonstrate a positive association between HCV load of viremia and the mutant genotype IL-4-589/TT accompanied with low expression IL-4 in comparison with IL-6 expression.

CONCLUSIONS

These data suggest that the expression of IL-4 is inversely proportional to HCV load of viremia, and this connection is due to the high level of mutant genotype IL-4-589/TT in infected patients located in gene promoter and inhibits gene expression.