Balsalazide Potentiates Parthenolide-Mediated Inhibition of Nuclear Factor-κB Signaling in HCT116 Human Colorectal Cancer Cells

Roles of Inflammasomes in Epstein-Barr Virus-Associated Nasopharyngeal Cancer

Epstein-Barr virus (EBV) infection is recognised as one of the causative agents in most nasopharyngeal carcinoma (NPC) cases. Expression of EBV viral antigens can induce host's antiviral immune response by activating the inflammasomes to produce pro-inflammatory cytokines, such as interleukin-1β (IL-1β) and IL-18. These cytokines are known to be detrimental to a wide range of virus-infected cells, in which they can activate an inflammatory cell death program, called pyroptosis. However, aberrant inflammasome activation and production of its downstream cytokines lead to chronic inflammation that may contribute to various diseases, including NPC. In this review, we summarise the roles of inflammasomes during viral infection, how EBV evades inflammasome-mediated immune response, and progress into tumourigenesis. The contrasting roles of inflammasomes in cancer, as well as the current therapeutic approaches used in targeting inflammasomes, are also discussed in this review. While the inflammasomes appear to have dual roles in carcinogenesis, there are still many questions that remain unanswered. In particular, the exact molecular mechanism responsible for the regulation of the inflammasomes during carcinogenesis of EBV-associated NPC has not been explored thoroughly. Furthermore, the current practical application of inflammasome inhibitors is limited to specific tumour types, hence, further studies are warranted to discover the potential of targeting the inflammasomes for the treatment of NPC.

Computational investigation of FDA approved drugs as selective PARP-1 inhibitors by targeting BRCT domain for cancer therapy

Poly(ADP-ribose) polymerase-1 is a promising target for the treatment of cancer due to its involvement in base excision repair pathways for repairing DNA single-strand breaks. However, available PARP-1 inhibitors target a highly conserved PARPs catalytic domain, which causes toxicity due to the off-target activity. Therefore, the present study was hypothesized to identify selective inhibitors by targeting specific protein-protein interacting (PPI) PARP-1 BRCT domain. Moreover, PPI hotspot residues (Gly399, Lys400, Leu401, Lys441 & Lys442) and a druggable pocket was detected to screen small molecule inhibitors. Hence, two FDA approved drug molecules (levoleucovorin and balsalazide) were recognized to fit in the druggable pocket. Since they are already under investigation for anti-cancer activity, thus could be further explored in PARP-1 sensitive cancer cells to expand their selectivity and develop as effective anti-cancer agents. Besides, the study also provides detailed structural insight of PARP-1 and XRCC1 complex through their BRCT domains.

Integration of genetic variants and gene network for drug repurposing in colorectal cancer

Even though many genetic risk loci for human diseases have been identified and comprehensively cataloged, strategies to guide clinical research by integrating the extensive results of genetic studies and biological resources are still limited. Moreover, integrative analyses that provide novel insights into disease biology are expected to be especially useful for drug discovery. Herein, we used text mining of genetic studies on colorectal cancer (CRC) and assigned biological annotations to identified risk genes in order to discover novel drug targets and potential drugs for repurposing. Risk genes for CRC were obtained from PubMed text mining, and for each gene, six functional and bioinformatic annotations were analyzed. The annotations include missense mutations, cis-expression quantitative trait loci (cis-eQTL), molecular pathway analyses, protein-protein interactions (PPIs), a genetic overlap with knockout mouse phenotypes, and primary immunodeficiency (PID). We then prioritized the biological risk candidate genes according to a scoring system of the six functional annotations. Each functional annotation was assigned one point, and those genes with a score ≥2 were designated "biological CRC risk genes". Using this method, we revealed 82 biological CRC risk genes, which were mapped to 128 genes in an expanded PPI network. Further utilizing DrugBank and the Therapeutic Target Database, we found 21 genes in our list that are targeted by 166 candidate drugs. Based on data from ClinicalTrials.gov and literature review, we found four known target genes with six drugs for clinical treatment in CRC, and three target genes with nine drugs supported by previous preclinical results in CRC. Additionally, 12 genes are targeted by 32 drugs approved for other indications, which can possibly be repurposed for CRC treatment. Finally, analysis from Connectivity Map (CMap) showed that 18 drugs have a high potential for CRC.

Parthenolide as Cooperating Agent for Anti-Cancer Treatment of Various Malignancies

Primary and acquired resistance of cancer to therapy is often associated with activation of nuclear factor kappa B (NF-κB). Parthenolide (PN) has been shown to inhibit NF-κB signaling and other pro-survival signaling pathways, induce apoptosis and reduce a subpopulation of cancer stem-like cells in several cancers. Multimodal therapies that include PN or its derivatives seem to be promising approaches enhancing sensitivity of cancer cells to therapy and diminishing development of resistance. A number of studies have demonstrated that several drugs with various targets and mechanisms of action can cooperate with PN to eliminate cancer cells or inhibit their proliferation. This review summarizes the current state of knowledge on PN activity and its potential utility as complementary therapy against different cancers.

Anticancer and apoptotic activities of parthenolide in combination with epirubicin in mda-mb-468 breast cancer cells

Breast cancer is the most common malignancy in women worldwide. Unfortunately, current therapeutic methods are not completely efficient. Hence, combination therapy with medicinal plants has attracted several kinds of research. In the current study, we aimed to investigate the apoptotic and anti-cancer effect of Parthenolide in combination with Epirubicin in the MDA-MB-468 breast cancer cell line. In this study,  the anti-proliferative and pro-apoptotic effect of Parthenolide in combination with Epirubicin and without it, in the MDA-MB-468 cell line have been assessed by MTT test, Hoescht staining and flow cytometry methods. Our outcomes showed that Parthenolide treatment in the present of Epirubicin led to a decrease in the minimum toxic concentration of Parthenolide and Epirubicin in comparison with individual treatments. Then, to achieve a likely molecular mechanism of mentioned drugs Bax and Bcl2 expression level evaluated by Real-time PCR and subsequently, Western blotting has been estimated the protein level of Caspase 3. Our data indicated that the treatment of cells with Parthenolide led to up-regulation of Bax and downregulation of Bcl2 at mRNA level. Moreover, Parthenolide treatment led to the obvious alternation of Caspase3 protein level. These results indicated that Parthenolide in combination with Epirubicin have significant cytotoxicity due to targeting the main regulators of apoptosis. Hence, according to lack of cytotoxicity of Parthenolide on normal cells that lead to reduction of drug side effects, it could be suggested as an adjuvant therapy with Epirubicin after complementary research on animal model and clinical trial.

Identification of Autophagy-Associated Biomarkers and Corresponding Regulatory Factors in the Progression of Colorectal Cancer

Autophagy is a self-degradation process that maintains homeostasis against stress in cells. Autophagy dysfunction plays a central role in the development of tumors, such as colorectal cancer (CRC). In this study, autophagy-related differentially expressed genes, their downstream functions, and upstream regulatory factors including RNA-binding proteins (RBP) involved in programmed cell death in the CRC were investigated. Transcription factors (TFs) and miRNAs have been shown to mainly regulate autophagy genes. Interestingly, we found that some of the RBP in the CRC, such as DDX17, SETDB1, and POLR3A, play an important regulatory role in maintaining autophagy at a basal level during growth by acting as TFs that regulate autophagy. Promoter methylations showed negative regulations on differentially expressed autophagy gene (DEAG), while copy number variations revealed a positive role in them. A proportional hazards regression analysis indicated that using autophagy-related prognostic signature can divide patients into high-risk and low-risk groups. Autophagy associated FDA-approved drugs were studied by a prognostic network. This would contribute to the identifications of new potential molecular therapeutic targets for CRC.

Parthenolide attenuated bleomycin-induced pulmonary fibrosis via the NF-κB/Snail signaling pathway

Background

Parthenolide (PTL) is a natural molecule isolated from Tanacetum parthenium that exhibits excellent anti-inflammatory and antitumor activities. Pulmonary fibrosis (PF), especially idiopathic pulmonary fibrosis (IPF), is a chronic lung disease that lacks a proven effective therapy. The present study evaluated the therapeutic effect of PTL on PF.

Methods

Serum-starved primary lung fibroblasts and HFL1 cells were treated with different doses of PTL, and cell viability and the migration rate were measured. Western blot analysis and a dual-luciferase assay were used to analyze the epithelial–mesenchymal transition (EMT)-related transcription factors influenced by PTL treatment in A549 cells and primary lung epithelial cells. Mice with bleomycin (BLM)-induced pulmonary fibrosis were treated with different doses of intragastric PTL, and pathological changes were evaluated using Hematoxylin-eosin (H&E) staining and immunohistochemical analysis.

Results

Our results demonstrated that PTL reduced the cell viability and migration rate of lung fibroblasts and inhibited the expression of EMT-related transcription factors in lung epithelial cells. In vivo studies demonstrated that PTL attenuated BLM-induced pulmonary fibrosis and improved the body weight and pathological changes of BLM-treated mice. We further demonstrated that PTL attenuated BLM-induced PF primarily via inhibition of the NF-κB/Snail signaling pathway.

Conclusion

These findings suggest that PTL inhibits EMT and attenuates BLM-induced PF via the NF-κB/Snail signaling pathway. PTL is a worthwhile candidate compound for pulmonary fibrosis therapy.

Juglanin inhibits lung cancer by regulation of apoptosis, ROS and autophagy induction

Juglanin (Jug) is obtained from the crude extract of Polygonum aviculare, exerting suppressive activity against cancer cell progression in vitro and in vivo. Juglanin administration causes apoptosis and reactive oxygen species (ROS) in different types of cells through regulating various signaling pathways. In our study, the effects of juglanin on non-small cell lung cancer were investigated. A significant role of juglanin in suppressing lung cancer growth was observed. Juglanin promoted apoptosis in lung cancer cells through increasing Caspase-3 and poly ADP-ribose polymerase (PARP) cleavage, which is regulated by TNF-related apoptosis-inducing ligand/Death receptors (TRAIL/DRs) relied on p53 activation. Anti-apoptotic members Bcl-2 and Bcl-xl were reduced, and pro-apoptotic members Bax and Bad were enhanced in cells and animals receiving juglanin. Additionally, nuclear factor-κB (NF-κB), phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) and mitogen-activated protein kinases (MAPKs) activation were inhibited by juglanin. Further, juglanin improved ROS and induced autophagy. ROS inhibitor N-acetyl-l-cysteine (NAC) reversed apoptosis induced by juglanin in cancer cells. The formation of autophagic vacoules and LC3/autophagy gene7 (ATG7)/Beclin1 (ATG6) over-expression were observed in juglanin-treated cells. Also, juglanin administration to mouse xenograft models inhibited lung cancer progression. Our study demonstrated that juglanin could be a promising candidate against human lung cancer progression.

Sesquiterpene binding Gly-Leu-Ser/Lys-"co-adaptation pocket" to inhibit lung cancer cell epithelial-mesenchymal transition

Sesquiterpene lactones (SL) have a wide range of applications in anti-tumor and anti-inflammatory therapy. However, the pharmacological mechanism of such substances is not clear. In this study, parthenolide (PTL) was used as an example to explore the anti-tumor effect of natural molecules and their common mechanism. We showed that PTL inhibited the proliferation and migration by reverse EMT via the ERK2/NF-κB/Snail pathway in vivo and in vitro. Interestingly, Multiple potential targets of PTL contain a Gly-Leu-Ser/Lys-“co-adaptation pocket”. This inspiring us analogies of PTL may also bind to these target proteins and play a similar function. Significantly, the Concept of co-adaptation pocket may help to increase the selectivity of drug research and development.

Ursodeoxycholic acid inhibits the proliferation of colon cancer cells by regulating oxidative stress and cancer stem-like cell growth

INTRODUCTION

The regulation of reactive oxygen species (ROS) exists as a therapeutic target for cancer treatments. Previous studies have shown that ursodeoxycholic acid (UDCA) suppresses the proliferation of colon cancer cells. The aim of this study was to evaluate the effect of UDCA upon the proliferation of colon cancer cells as a direct result of the regulation of ROS.

METHOD

Colon cancer cell lines (HT29 and HCT116) were treated with UDCA. The total number of cells and the number of dead cells were determined using cell counters. A fluorescein isothiocyanate-bromodeoxyuridine flow kit was used to analyze cell cycle variations. Upon exposure to UDCA, the protein levels of p27, p21, CDK2, CDK4 and CDK6 were determined using western blotting, and qRT-PCR was used to determine levels of mRNA. We preformed dichlorofluorescindiacetate (DCF-DA) staining to detect alteration of intracellular ROS using fluorescence activated cell sorting (FACS). Colon cancer stem-like cell lines were generated by tumorsphere culture and treated with UDCA for seven days. The total number of tumorspheres was determined using microscopy.

RESULTS

We found that UDCA reduced the total number of colon cancer cells, but did not increase the number of dead cells. UDCA inhibited the G1/S and G2/M transition phases in colon cancer cells. UDCA induced expression of cell cycle inhibitors such as p27 and p21. However, it was determined that UDCA suppressed levels of CDK2, CDK4, and CDK6. UDCA regulated intracellular ROS generation in colon cancer cells, and induced activation of Erk1/2. Finally, UDCA inhibited formation of colon cancer stem-like cells.

CONCLUSION

Our results indicate that UDCA suppresses proliferation through regulation of oxidative stress in colon cancer cells, as well as colon cancer stem-like cells.

Dietary selenium protects adiponectin knockout mice against chronic inflammation induced colon cancer

Selenium (Se) is an essential dietary micronutrient that has been examined for protection against different types of cancers including colon cancer. Despite an established inverse association between Se and chronic inflammation induced colon cancer (CICC), the mechanistic understanding of Se's protective effects requires additional in-vivo studies using preclinical animal models of CICC. Adiponectin (APN) is an adipocytokine that is protective against CICC as well. However, its role in the anti-mutagenic effects of the Se-diet remains unknown. To address this knowledge gap, here we examine the ability of dietary Se in reducing CICC in APN knockout mice (KO) and its wild-type C57BL/6. CICC was induced with the colon cancer agent 1,2 dimethyl hydrazine (DMH) along with dextran sodium sulfate (DSS). Se-enhanced diet increased selenoproteins, Gpx-1 and Gpx-2, in the colon tissues, thereby reducing oxidative stress. Se-mediated reduction of CICC was evident from the histopathological studies in both mouse models. In both mice, reduction in inflammation and tumorigenesis associated well with reduced p65 phosphorylation and elevated 53 phosphorylation. Finally, we show that in both models Se-administration promotes goblet cell differentiation with a concomitant increase in the levels of associated proteins, Muc-2 and Math-1. Our findings suggest that Se's protection against CICC involves both colonic epithelial protection and anti-tumor effects that are independent of APN.

Cyr61 participates in the pathogenesis of acute lymphoblastic leukemia by enhancing cellular survival via the AKT/NF-κB signaling pathway

Cyr61 (CCN1) is the product of a growth factor–inducible immediate early gene and is involved in cell adhesion, survival, proliferation, and differentiation. Cyr61 is overexpressed in human tumors and is involved in the development of tumors. However, the role that Cyr61 plays in acute lymphoblastic leukemia (ALL) cells remains undetermined. The aim of this study was to identify the role of Cyr61 in regulating ALL cell survival. Here, we found that the level of Cyr61 was increased in the plasma and bone marrow (BM) from ALL patients compared with samples from normal control patients. Furthermore, we observed that Cyr61 could effectively stimulate Jurkat (T ALL cell lines), Nalm-6 (B ALL cell lines), and primary ALL cell survival. Mechanistically, we showed that Cyr61 stimulated ALL cell survival via the AKT/NF-κB signaling pathways and the consequent up-regulation of Bcl-2. Taken together, our study is the first to reveal that Cyr61 is elevated in ALL and promotes cell survival through the AKT/NF-κB pathway by up-regulating Bcl-2. Our findings suggest that Cyr61 plays an important role in the pathogenesis of ALL.