Activation of NF-κB: bridging the gap between inflammation and cancer in colitis-mediated colon carcinogenesis

Inhibition of the STAT3-EPHX2 axis promotes regression of ulcerative colitis by treatment with novel porphyrin derivative

LD4, a novel porphyrin derivative, has attracted much attention for its excellent anti-inflammatory properties. It can promote the healing of colonic mucosa, reduce inflammatory response, regulate oxidative stress, and thus improve ulcerative colitis (UC) symptoms. However, the specific signaling pathways of LD4-PDT involved in UC have not been explored. The present study aimed to elucidate the effects of LD4 on UC and to investigate the underlying mechanisms both in vivo and in vitro. We classified and screened the LD4-PDT proteomic data to obtain key targets. Proteomic data revealed that EPHX2 and STAT3 are key targets of LD4-PDT for UC. Moreover, transcription factor STAT3 positively regulates the expression of EPHX2. Inhibiting EPHX2 can prevent the activation of NF-κB signaling pathway. Next, through pharmacological inhibition experiments, we confirmed that LD4-PDT can reduce intestinal inflammation by inhibiting STAT3-EPHX2 axis. However, by treating normal intestinal epithelial cells and colon cancer cells with TPPU and Stattic, our data confirmed that the STAT3-EPHX2 axis does not exist in colon cancer. In this study, we demonstrated that the transcription factor STAT3 can positively regulate the expression of EPHX2 in normal colon. LD4 can alleviate UC by inhibiting the STAT3-EPHX2 axis, but this axis does not exist in colon cancer. LD4-PDT may become a new and effective method for treating UC.

Exogenous 1,25(OH)2D3/VD3 counteracts RSL3-Induced ferroptosis by enhancing antioxidant capacity and regulating iron ion transport: Using zebrafish as a model

RSL3 is a common inhibitor of glutathione peroxidase 4 (GPx4) that can induce ferroptosis. Ferroptosis is an iron ion-dependent, oxidative-type of programmed cell death. In this study, larval/adult zebrafish were stimulated with RSL3 to construct a ferroptosis model, and CYP2R1-/- zebrafish was used as a 1,25(OH)2D3 knock-down model to explore the regulatory effect and mechanism of 1,25(OH)2D3/VD3 on RSL3-induced ferroptosis. The results showed that 1,25(OH)2D3/VD3 alleviated RSL3 induced mitochondrial damage in liver of larval/adult zebrafish, reversed the decline of GPx4 activity, and reduced the accumulation of ROS, LPO and MDA. VD3 also inhibited hepcidin (HEPC) in adult fish liver, promoted the production of ferroportin (FPN), and reduced the aggregation of Fe2+. Exogenous 1,25(OH)2D3 increased the CYP2R1-/- survival and liver GPx4 activity after RSL3 treatment. At the gene level, 1,25(OH)2D3/VD3 activated Keap1-Nrf2-GPx4 and inhibited the NFκB-hepcidin axis. In the ferroptosis context, deletion of the cyp2r1 gene resulted in a more severe decline in gpx4 expression, but the exogenous 1,25(OH)2D3 increased the expression of the GPx4 gene and protein in CYP2R1-/- zebrafish liver after RSL3 treatment. The collective results indicated that 1,25(OH)2D3/VD3 can inhibit ferroptosis induced by RSL3 in liver of larval/adult zebrafish by improving the antioxidant capacity and regulating iron ion transport. Exogenous 1,25(OH)2D3 reverses the downregulation of GPx4 in the CYP2R1-/- zebrafish liver in the ferroptosis state. Compared with the ferroptosis inhibitor Fer-1, the mechanism of action of 1,25(OH)2D3/VD3 is diversified and nonspecific. This study demonstrated the resistance of VD3 to RSL3-induced ferroptosis at different developmental stages in zebrafish.

Heme oxygenase 1 alleviates nonalcoholic steatohepatitis by suppressing hepatic ferroptosis

BACKGROUND

Heme oxygenase 1 (HO-1) has an influential but insufficiently investigated effect on ferroptosis, which is a novel form of programmed cell death and may play an effect on nonalcoholic steatohepatitis (NASH). However, the understanding of the mechanism is limited. Herein, our study aimed to explore the mechanism and role of HO-1 in NASH ferroptosis.

METHODS

Hepatocyte conditional HO-1 knockout (HO-1^HEPKO) C57BL/6J mice were established and fed a high-fat diet (HFD). Additionally, wild-type mice were fed either a normal diet or a HFD. Hepatic steatosis, inflammation, fibrosis, lipid peroxidation, and iron overload were assessed. AML12 and HepG2 cells were used to investigate the underlying mechanisms in vitro. Finally, liver sections from NASH patients were used to clinically validate the histopathology of ferroptosis.

RESULTS

In mice, HFD caused lipid accumulation, inflammation, fibrosis, and lipid peroxidation, which were aggravated by HO-1^HEPKO. In line with the in vivo results, HO-1 knockdown upregulated reactive oxygen species accumulation, lipid peroxidation, and iron overload in AML12 and HepG2 cells. Additionally, HO-1 knockdown reduced the GSH and SOD levels, which was in contrast to HO-1 overexpression in vitro. Furthermore, the present study revealed that the NF-κB signaling pathway was associated with ferroptosis in NASH models. Likewise, these findings were consistent with the liver histopathology results of NASH patients.

CONCLUSION

The current study showed that HO-1 could alleviate NASH progression by mediating ferroptosis.

Tumor Necrosis Factor Alpha: Implications of Anesthesia on Cancers

Cancer remains a major public health issue and a leading cause of death worldwide. Despite advancements in chemotherapy, radiation therapy, and immunotherapy, surgery is the mainstay of cancer treatment for solid tumors. However, tumor cells are known to disseminate into the vascular and lymphatic systems during surgical manipulation. Additionally, surgery-induced stress responses can produce an immunosuppressive environment that is favorable for cancer relapse. Up to 90% of cancer-related deaths are the result of metastatic disease after surgical resection. Emerging evidence shows that the interactions between tumor cells and the tumor microenvironment (TME) not only play decisive roles in tumor initiation, progression, and metastasis but also have profound effects on therapeutic efficacy. Tumor necrosis factor alpha (TNF-α), a pleiotropic cytokine contributing to both physiological and pathological processes, is one of the main mediators of inflammation-associated carcinogenesis in the TME. Because TNF-α signaling may modulate the course of cancer, it can be therapeutically targeted to ameliorate clinical outcomes. As the incidence of cancer continues to grow, approximately 80% of cancer patients require anesthesia during cancer care for diagnostic, therapeutic, or palliative procedures, and over 60% of cancer patients receive anesthesia for primary surgical resection. Numerous studies have demonstrated that perioperative management, including surgical manipulation, anesthetics/analgesics, and other supportive care, may alter the TME and cancer progression by affecting inflammatory or immune responses during cancer surgery, but the literature about the impact of anesthesia on the TNF-α production and cancer progression is limited. Therefore, this review summarizes the current knowledge of the implications of anesthesia on cancers from the insights of TNF-α release and provides future anesthetic strategies for improving oncological survival.

Role of Nrf2, STAT3, and Src as Molecular Targets for Cancer Chemoprevention

Cancer is a complex and multistage disease that affects various intracellular pathways, leading to rapid cell proliferation, angiogenesis, cell motility, and migration, supported by antiapoptotic mechanisms. Chemoprevention is a new strategy to counteract cancer; to either prevent its incidence or suppress its progression. In this strategy, chemopreventive agents target molecules involved in multiple pathways of cancer initiation and progression. Nrf2, STAT3, and Src are promising molecular candidates that could be targeted for chemoprevention. Nrf2 is involved in the expression of antioxidant and phase II metabolizing enzymes, which have direct antiproliferative action as well as indirect activities of reducing oxidative stress and eliminating carcinogens. Similarly, its cross-talk with NF-κB has great anti-inflammatory potential, which can be utilized in inflammation-induced/associated cancers. STAT3, on the other hand, is involved in multiple pathways of cancer initiation and progression. Activation, phosphorylation, dimerization, and nuclear translocation are associated with tumor cell proliferation and angiogenesis. Src, being the first oncogene to be discovered, is important due to its convergence with many upstream stimuli, its cross-talk with other potential molecular targets, such as STAT3, and its ability to modify the cell cytoskeleton, making it important in cancer invasion and metastasis. Therefore, the development of natural/synthetic molecules and/or design of a regimen that can reduce oxidative stress and inflammation in the tumor microenvironment and stop multiple cellular targets in cancer to stop its initiation or retard its progression can form newer chemopreventive agents.

Piclamilast mitigates 1,2-dimethylhydrazine induced colon cancer in rats through modulation of Ras/PI3K/Akt/mTOR and NF-κβ signaling

Colorectal cancer (CRC) is the third leading type of adult cancer in both genders with high morbidity and mortality worldwide. Even though the discovery of many antineoplastic drugs for CRC, the current therapy is not adequately efficient.This study was designed to investigate the effect and mechanism of Piclamilast (PIC), a selective PDE4 inhibitor, on a DMH-induced colorectal cancer (CRC) rat model. The rats were grouped (n = 10) into group 1 (control), group 2 (PIC 3 mg/kg, p.o.), groups 3-5 received DMH (20 mg/kg/week, S.C.), and groups 4 and 5 received PIC (1 and 3 mg/kg/day, p.o.) for 15 weeks. The DMH treatment increased aberrant crypt foci (ACF), Proliferating cell nuclear antigen (PCNA), and TBARS levels, along with decreased antioxidant defenses (GSH, GSH-Px, and catalase). Increased NF-κβ expression and inflammatory cytokines were also evident. PIC dose-dependently reduced ACF and restored oxidative stress and inflammatory markers favorably. Moreover, PIC in its large, tested dose only significantly increased the intracellular level of cAMP and suppressed the activation of Ras and PI3K and its downstream Akt/mTOR signaling. Furthermore, PIC promoted CRC apoptosis, and increased the gene expression of the apoptotic factors, caspase-3 and Bax, and decreased the anti-apoptotic factor Bcl-2. The results of this study show that PIC may be a promising therapeutic agent for the treatment of CRC. PIC might inhibit the proliferation of CRC cells and induce apoptosis via multiple mechanisms that involve its antioxidant effect and inhibition of NF-κβ and Ras/PI3K/Akt/mTOR signaling.

Lentinan Attenuates Damage of the Small Intestinal Mucosa, Liver, and Lung in Mice with Gut-Origin Sepsis

This study is aimed at exploring the effects of lentinan on small intestinal mucosa as well as lung and liver injury in mice with gut-origin sepsis. Cecal ligation and perforation (CLP) were used to construct a mouse model of gut-origin sepsis. The mice were randomly divided into six groups: sham operation group (sham), gut-origin sepsis model group (CLP), ulinastatin-positive drug control group (UTI), lentinan low concentration group (LTN-L, 5 mg/kg), lentinan medium concentration group (LTN-M, 10 mg/kg), and lentinan high concentration group (LTN-H, 20 mg/kg). H&E staining was used to detect the pathological damage of the small intestine, liver, and lung. The serum of mice in each group was collected to detect the expression changes of inflammatory cytokines, oxidative stress biomarkers, and liver function indexes. In vitro assessment of bacterial translocation was achieved through inoculated culture media. Western blot and RT-qPCR were used to detect the expression of molecules related to the NF-κB signaling pathway in the small intestine tissues of mice. The results showed that compared with the CLP group, the injury degree of the small intestine, liver, and lung in mice with gut-origin sepsis was improved with the increase of lentinan concentration. In addition, TNF-α, IL-1β, IL-6, and HMGB1 were decreased with the increase of lentinan concentration, but the expression of IL-10 was increased. Lentinan could also reduce the expression of oxidative stress injury indexes and liver function indexes and inhibit bacterial translocation to liver and lung tissues. Further mechanism investigation revealed that lentinan downregulated the expression of the NF-κB signaling pathway molecules (NF-κB, TLR4, and Bax) and upregulated the expression of occludin and Bcl-2. In conclusion, lentinan inhibits the activity of the NF-κB signaling pathway, thus attenuating injuries of small intestinal mucosa and liver and lung in mice with gut-origin sepsis and reducing the inflammatory response in the process of sepsis.

1,25(OH)2D3 Inhibited Ferroptosis in Zebrafish Liver Cells (ZFL) by Regulating Keap1-Nrf2-GPx4 and NF-κB-hepcidin Axis

Ferroptosis is a kind of iron-dependent programed cell death. Vitamin D has been shown to be an antioxidant and a regulator of iron metabolism, but the relationship between vitamin D and ferroptosis is poorly studied in fish. This study used zebrafish liver cells (ZFL) to establish a ferroptosis model to explore the effect of 1,25(OH)₂D₃ on cell ferroptosis and its mechanism of action. The results showed that different incubation patterns of 1,25(OH)₂D₃ improved the survival rate of ZFL, mitigated mitochondrial damage, enhanced total glutathione peroxidase (GPx) activity, and reduced intracellular reactive oxygen species (ROS), lipid peroxidation (LPO), and malondialdehyde (MDA), as well as iron ion levels, with the best effect at 200 pM 1,25(OH)₂D₃ preincubation for 72 h. Preincubation of ZFL at 200 pM 1,25(OH)₂D₃ for 72 h downgraded keap1 and ptgs2 gene expression, increased nrf2, ho-1, fth1, gpx4a,b expression, and lowered the expression of the nf-κb p65,il-6,il-1β gene, thus reducing the expression of hamp1. The above results indicate that different incubation patterns of 1,25(OH)₂D₃ have protective effects on ferroptosis of ZFL induced by ferroptosis activator RSL3 and 1,25(OH)₂D₃ can inhibit ferroptosis of ZFL by regulating Keap1-Nrf2-GPx4 and NF-κB-hepcidin axis.

MIF inhibitor, ISO-1, attenuates human pancreatic cancer cell proliferation, migration and invasion in vitro, and suppresses xenograft tumour growth in vivo

This study sought to investigate the biological effects of specific MIF inhibitor, ISO-1, on the proliferation, migration and invasion of PANC-1 human pancreatic cells in vitro, and on tumour growth in a xenograft tumour model in vivo. The effect of ISO-1 on PANC-1 cell proliferation was examined using CCK-8 cell proliferation assay. The effect of ISO-1 on collective cell migration and recolonization of PANC-1 cells was evaluated using the cell-wound closure migration assay. The effect of ISO-1 on the migration and invasion of individual PANC-1 cells in a 3-dimensional environment in response to a chemo-attractant was investigated through the use of Transwell migration/invasion assays. Quantitative real time PCR and western blot analyses were employed to investigate the effects of ISO-1 on MIF, NF-κB p65 and TNF-α mRNA and protein expression respectively. Finally, a xenograft tumor model in BALB/c nude mice were used to assess the in vivo effects of ISO-1 on PANC-1-induced tumor growth. We found high expression of MIF in pancreatic cancer tissues. We demonstrated that ISO-1 exerts anti-cancer effects on PANC-1 cell proliferation, migration and invasion in vitro, and inhibited PANC-1 cell-induced tumour growth in xenograft mice in vivo. Our data suggests that ISO-1 and its derivative may have potential therapeutic applications in pancreatic cancer.

The effect of TLR4 on the growth and local inflammatory microenvironment of HPV-related cervical cancer in vivo

BACKGROUND

Cervical cancer is the most common malignancy of the female lower genital tract. In our previous study, we found that TLR4 promotes cervical cancer cell growth in vitro. The aim of this study was to further explore the role of TLR4 in HPV-related cervical cancer in vivo by using a nude mouse xenograft model.

METHODS

Cervical cancer-derived HeLa and CaSki cells (5 × 107/mL) were either stimulated with an optimal concentration of LPS for the appropriate time (HeLa cells were treated with 1 μg/mL LPS for 1 h, and CaSki cells were treated with 2 μg/mL LPS for 1.5 h) or transfected with TLR4 shRNA and then injected subcutaneously into the dorsal right posterior side of nude mice. The shortest width and longest diameter of the transplanted tumors in the nude mice were measured every 3 days.TLR4, IL-6,iNOS, IL-8,COX-2, MIP-3α, TGF-β1 and VEGF expression levels in the transplanted tumor tissue were detected by immunohistochemistry.

RESULTS

The tumor formation rate was 100% in both HeLa and CaSki nude mouse groups. The tumors grew faster, and the cachexia symptoms were more serious in the LPS groups than in the control group. In contrast, the tumors grew slower, and the cachexia symptoms were milder in the TLR4-silenced groups. TLR4, iNOS, IL-6, MIP-3α and VEGF were highly expressed in the transplanted tumor tissues from the LPS groups, and their expression levels were decreased in the TLR4-silenced groups.

CONCLUSION

TLR4 expression is closely associated with the tumorigenesis and growth of HPV-positive cervical cancer; TLR4 promotes HPV-positive cervical tumor growth and facilitates the formation of a local immunosuppressive microenvironment. Eventually, these conditions may lead to cervical cancer development.

Saccharomyces boulardii alleviates ulcerative colitis carcinogenesis in mice by reducing TNF-α and IL-6 levels and functions and by rebalancing intestinal microbiota

BACKGROUND AND AIMS

To explore the inhibition mechanism of Saccharomyces boulardii (S. boulardii) on ulcerative colitis (UC) carcinogenesis.

METHODS

C57BL/6 mice were treated with azoxymethane and dextran sulfate sodium (AOM/DSS) to develop a UC carcinogenesis model. The treatment group was lavaged with S. boulardii (5 × 10⁷ CFU/d) for 12 weeks. The mice were sacrificed and the tumor load in the treatment group was compared with that of a control group. The levels of TNF-α and IL-6 in colon tissue were measured by enzyme-linked immunosorbent assays. The influence of S. boulardii on TNF-α and IL-6 regulation was also investigated using different colon cell lines. Differences in intestinal microbiota in both stool and intestinal mucosa samples were assessed using 16S rDNA sequencing.

RESULTS

S. boulardii treatment reduced AOM/DSS-induced UC carcinogenesis in mice, as indicated by the reduced tumor load and reduced TNF-α and IL-6 levels in vivo, as well its effects on TNF-α and IL-6 activities in vitro. Significant changes in both fecal and mucosal microbiota were observed among the control, the AOM/DSS treated, and AOM/DSS plus S. boulardii treated groups. For fecal microbiota, the AOM/DSS treated group was lower in Lactobacillus, but higher in Oscillibacter and Lachnoclostridium than the control group. After intervention with S. boulardii, the percentage of Bacillus and Lactococcus increased, but Lachnoclostridium, Oscillibacter, Bacteroides, and Pseudomonas decreased. For the intestinal mucosal microbiota, the AOM/DSS treated group was lower in Bifidobacterium and Ruminococcaceae_UCG-014 and higher in Alloprevotella than the control group. After S. boulardii exposure, the percentage contributions of Lachnoclostridium and Lachnospiraceae_NK4A136 increased.

CONCLUSIONS

S. boulardii effectively reduced UC carcinogenesis in an AOM/DSS induced mice model. This positive result can likely be attributed to the reduction of TNF-α and IL-6 levels or the blockade of their function combined with alterations to the intestinal microbiota.

Inflammation and pancreatic cancer: An updated review

Pancreatic cancer is a devastating disease with poor prognosis in the modern era. Inflammatory processes have emerged as key mediators of pancreatic cancer development and progression. Recently, studies have been carried out to investigate the underlying mechanisms that contribute to tumorigenesis induced by inflammation. In this review, the role of inflammation in the initiation and progression of pancreatic cancer is discussed.

REGγ Controls Hippo Signaling and Reciprocal NF-κB-YAP Regulation to Promote Colon Cancer

Purpose: Colorectal cancer is one of the most commonly diagnosed cancers closely associated with inflammation and hyperactive growth. We previously demonstrated a regulatory circuit between the proteasome activator REGγ and NF-kappaB (NF-κB) during colon inflammation, known to be important in the development of colitis-associated cancer as well as sporadic colorectal cancer. How the inflammatory microenvironment affects the Hippo pathway during colorectal cancer development is largely unknown.Experimental Design: Here, we used REGγ-deficient colon cancer cell lines, REGγ knockout mice, and human colorectal cancer samples to identify the novel molecular mechanism by which REGγ functions as an oncoprotein in the development of colorectal cancer.Results: REGγ can directly interact with Lats1 and promote its degradation, which facilitates Yes-associated protein (YAP) activation in colon cancer cells. REGγ deficiency significantly attenuated colon cancer growth, associated with decreased YAP activity. Suppression of tumor growth due to REGγ depletion was overcome by constitutively active YAP. Surprisingly, reciprocal activation of the YAP and NF-κB pathways was observed in human colon cancer cells. REGγ overexpression was found in over 60% of 172 colorectal cancer specimens, highly correlating with the elevation of YAP and p65. Postoperative follow-up revealed a significantly lower survival rate in patients with concomitantly high expression of REGγ, YAP, and p-p65.Conclusions: REGγ could be a master regulator during colorectal cancer development to promote YAP signaling and reinforce cross-talks between inflammation and growth pathways, and REGγ might be a new marker for prognosis of colorectal cancer patients. Clin Cancer Res; 24(8); 2015-25. ©2018 AACR.

Galantamine attenuates N,N-dimethyl hydrazine induced neoplastic colon damage by inhibiting acetylcholinesterase and bimodal regulation of nicotinic cholinergic neurotransmission

The present study reveals the effect of galantamine (GAL) against 1, 2-dimethylhydrazine (DMH) induced colon cancer. Wistar albino rats were arbitrarily divided into four groups (n = 8). Group 1 served as normal control (normal saline, 3ml/kg/day, p.o.); group 2, 3 and 4 received DMH (20mg/kg/week, s.c.), for 6 weeks; groups 3 and 4 also received GAL (2 and 4mg/kg/day, p.o) for 6 weeks. DMH treated rats showed decreased heart rate variability (HRV) factors, increased incidence of aberrant crypt foci (ACF), increased thiobarbituric acid reactive substances (TBARs) along with the decrease in the enzymatic activity of superoxide dismutase (SOD) and catalase. Increased levels of inflammatory marker cyclooxygenase (COX) and lipoxygenase (LOX) was also evident in DMH treated animals. The colonic surface architecture was studied using scanning electron microscopy revealed aberrant crypts(X500) and neoplastic nodules (X2000). GAL treatment helped to minimize the ACF count, restored oxidative stress and inflammatory markers favorably. To further validate our results, our study was directed to define the effect of GAL on acetylcholine neurotransmission using a simple model organism, Caenorhabditis elegans (C. elegans). Increased synaptic cholinergic transmission by GAL (32µM) was evident in the worms when studied through aldicarb assay. However, GAL (32µM) treatment negatively modulated α7 nicotinic acetylcholine receptor (α7nAch receptor), when evaluated using the levamisole assay. GAL (32µM) treatment down regulated the genomic expression of ace-1, ace-2 along with unc-29, unc-38, and unc-50 (essential components of α7 nAch receptor). GAL by inhibiting AchE and regulating Alpha7nACh activity can improve cholinergic neurotransmission.

Brassica-Derived Plant Bioactives as Modulators of Chemopreventive and Inflammatory Signaling Pathways

A high consumption of vegetables belonging to the Brassicaceae family has been related to a lower incidence of chronic diseases including different kinds of cancer. These beneficial effects of, e.g., broccoli, cabbage or rocket (arugula) intake have been mainly dedicated to the sulfur-containing glucosinolates (GLSs)-secondary plant compounds nearly exclusively present in Brassicaceae-and in particular to their bioactive breakdown products including isothiocyanates (ITCs). Overall, the current literature indicate that selected Brassica-derived ITCs exhibit health-promoting effects in vitro, as well as in laboratory mice in vivo. Some studies suggest anti-carcinogenic and anti-inflammatory properties for ITCs which may be communicated through an activation of the redox-sensitive transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) that controls the expression of antioxidant and phase II enzymes. Furthermore, it has been shown that ITCs are able to significantly ameliorate a severe inflammatory phenotype in colitic mice in vivo. As there are studies available suggesting an epigenetic mode of action for Brassica-derived phytochemicals, the conduction of further studies would be recommendable to investigate if the beneficial effects of these compounds also persist during an irregular consumption pattern.

Bortezomib protects against dextran sulfate sodium‑induced ulcerative colitis in mice

Bortezomib, a first-in-class proteasome inhibitor, is a standard method of treatment in multiple myeloma. In the present study, the therapeutic effect of bortezomib was evaluated in an ulcerative colitis model induced by dextran sulfate sodium (DSS) in mice, and the mechanism of action was also investigated. Mice were administered with 3% DSS drinking water for 7 consecutive days and then they were intraperitoneally treated with bortezomib (0.2, 0.6 or 1 mg/kg) for 1, 3 or 7 days. Mice in the control group and the DSS group were provided the same volume of PBS, respectively. Body weight, stool characteristics and hematochezia were observed. Serum levels of tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), albumin (ALB) and colonic activity of superoxide dismutase (SOD) were evaluated using specific kits. The expression of the transcription factor nuclear factor-κB (NF-κB) p65 gene and the DNA-binding activity of NF-κB protein were also evaluated. Administration of bortezomib attenuates colonic inflammation in mice. After 3 or 7 days of treatment, Disease Activity Index (DAI) as well as histological scores and NF-κB p65 protein expression were significantly reduced in mice treated with bortezomib at a dose of 0.6 or 1 mg/kg/day. Furthermore, it was also revealed that bortezomib was able to reduce serum levels of CRP and TNF-α caused by DSS and increase the level of ALB in serum and the activity of SOD in colonic tissues. These results demonstrated that bortezomib exerts a protective effect on DSS-induced colitis, and its underlying mechanisms are associated with the NF-κB gene inhibition that mitigates colon inflammatory responses in intestinal epithelial cells.

MiR-143 Targeting TAK1 Attenuates Pancreatic Ductal Adenocarcinoma Progression via MAPK and NF-κB Pathway In Vitro

BACKGROUND

Transforming growth factor (TGF)-β-activated kinase 1 (TAK1) is one of the major regulators of inflammation-induced cancer cell growth and progression. MiR-143 dysregulation is a common event in a variety of human diseases including pancreatic ductal adenocarcinoma (PDA).

AIMS

To identify the interaction between TAK1 and miR-143 in PDA.

METHODS

Data mining of TAK1 expression in PDA patient gene profiling was conducted. QRT-PCR and western blot were performed to detect the expression of TAK1 in PDA tissues and cell lines. Ectopic miR-143 and TAK1 were introduced to PDA cells. Cell growth, apoptosis and migration were examined. Xenograft models were used to examine the function of TAK1 in vivo. Western blot and luciferase assay were carried out to investigate the direct target of miR-143.

RESULTS

PDA patient gene profiling data (GSE15471 and GSE16515) showed that TAK1 mRNA was aberrantly up-regulated in PDA tissues. TAK1 protein levels were overexpressed in PDA tissues and cell lines. Overexpression of TAK1 was strongly associated with positive lymph node metastasis. Inhibition of TAK1 suppressed cell growth, migration, and induced cell apoptosis in vitro and in vivo. Further studies demonstrated that TAK1 was a direct target gene of miR-143. MiR-143 also inhibited PDA cells proliferation and migration, induced apoptosis and G₁/S arrest. Moreover, TAK1 depletion inactivated MAPK and NF-κB pathway, mimicking the function of miR-143.

CONCLUSIONS

The study highlights that miR-143 acts as a tumor suppressor in PDA through directly targeting TAK1, and their functional regulation may provide potential therapeutic strategies in clinics.

Lactobacillus rhamnosus induced epithelial cell apoptosis, ameliorates inflammation and prevents colon cancer development in an animal model

BACKGROUND/AIM

Probiotics have been suggested as prophylactic measure in colon carcinogenesis. This study aimed at determining the potential prophylactic activity of Lactobacillus rhamnosus GG CGMCC 1.2134 (LGG) strain on colorectal carcinogenesis via measuring its effect on Nuclear factor kappa B (NFκB) inflammatory pathway and apoptosis.

MATERIALS AND METHODS

64 Sprague Dawley rats were grouped into four as follows; Group 1 (Healthy control), Group 2 (LGG), Group 3 (cancer control Dimethyl hydrazine (DMH)) and Group 4 (LGG+DMH). LGG was administered orally to LGG and LGG+DMH groups. Colon carcinogenesis was chemically induced in LGG+DMH and DMH groups by weekly injection of 40mg/kg DMH. Animals were sacrificed after 25 weeks of experiment and tumor characteristics assessed. The change in expression of NFκB-p65, COX-2, TNFα, Bcl-2, Bax, iNOS, VEGFα, β-catenin, Casp3 and p53 were evaluated by western blotting and qRT-PCR.

RESULTS

LGG treatment significantly reduced tumor incidence, multiplicity and volume in LGG+DMH treatment group compared to DMH cancer control group. Also, LGG treatment reduced the expression of β-catenin and the inflammatory proteins NFκB-p65, COX-2 and TNFα; the anti-apoptotic protein Bcl-2, but increased the expression of the pro-apoptotic proteins Bax, casp3 and p53 compared with DMH group.

CONCLUSION

LGG have a potential protection effect against colon carcinogenesis; inducing apoptosis and ameliorating inflammation, and may hold a promise as bio-therapeutic dietary agent.

Transcription Factor NF-κB: An Update on Intervention Strategies

The nuclear factor (NF)-κB family of transcription factors are ubiquitous and pleiotropic molecules that regulate the expression of more than 150 genes involved in a broad range of processes including inflammation, immunity, cell proliferation, differentiation, and survival. The chronic activation or dysregulation of NF-κB signaling is the central cause of pathogenesis in many disease conditions and, therefore, NF-κB is a major focus of therapeutic intervention. Because of this, understanding the relationship between NF-κB and the induction of various downstream signaling molecules is imperative. In this review, we provide an updated synopsis of the role of NF-κB in DNA repair and in various ailments including cardiovascular diseases, HIV infection, asthma, herpes simplex virus infection, chronic obstructive pulmonary disease, and cancer. Furthermore, we also discuss the specific targets for selective inhibitors and future therapeutic strategies.

Sam68 modulates apoptosis of intestinal epithelial cells via mediating NF-κB activation in ulcerative colitis

Sam68 (Src-associated substrate during mitosis of 68 KDa), also known as KHDRBS1 (KH domain containing, RNA binding, signal transduction associated 1), belongs to the prototypic member of the signal transduction activator of RNA (STAR) family of RNA-binding proteins. Sam68 is implicated in various cellular processes including RNA metabolism, apoptosis, signal transduction. Previous researches demonstrated that Sam68 regulated nuclear transcription factor kappa B (NF-κB) to induce inflammation. However, the expression and biological functions of Sam68 in ulcerative colitis (UC) are not clear. In this study, we reported for the first time that Sam68 was up-regulated in intestinal epithelial cells (IECs) of patients with UC. In DSS-induced mouse colitis model, we observed the overexpression of Sam68 accompanied with increased levels of IEC apoptotic markers (active caspase-3 and cleaved PARP) and NF-κB activation indicators (p-p65 and p-IκB) in colitis IECs. Co-localization of Sam68 with active caspase-3 (and p-p65) in IECs of the DSS-induced colitis group further indicated the possible involvement of NF-κB-mediated IEC apoptosis. Applying TNF-α-treated HT-29 cells as an in vitro IEC inflammation model, we confirmed the positive correlation amomg Sam68, NF-κB activation and caspase-dependent apoptosis. Immunofluorescence and immunoprecipitation assay identified nuclear translocation and physical interaction of Sam68 and NF-κB subunits in TNF-α-treated HT-29 cells. Besides, depletion of Sam68 by RNA interference greatly alleviated NF-κB activation and apoptosis in TNF-α-treated HT-29 cells. Taken together, our results indicated that Sam68 modulates apoptosis of intestinal epithelial cells via mediating NF-κB activation in UC.

Soluble tumour necrosis factor receptor type II and survival in colorectal cancer

Background:

Chronic inflammation may play a role in colorectal cancer (CRC) pathogenesis. The relationship between soluble tumour necrosis factor receptor type II (sTNF-RII) and survival among CRC patients is not well defined.

Methods:

We prospectively evaluated the association between pre-diagnosis plasma levels of sTNF-RII and mortality in 544 CRC patients from the Nurses' Health Study and Health Professionals Follow-Up Study diagnosed from 1990 to 2010. Primary and secondary end points were overall and CRC-specific mortality, respectively. Cox proportional hazards models were used to calculate multivariate hazard ratios for mortality.

Results:

Higher sTNF-RII levels were significantly associated with increased overall mortality (multivariate HR=1.48, 95% CI 1.02–2.16, P-trend=0.006), but not with CRC-specific mortality (HR=1.23, 95% CI 0.72–2.08, P-trend=0.34). In subgroup analyses, among regular aspirin users, those with higher sTNF-RII levels had an adjusted HR of 0.52 (95% CI 0.20–1.33) for overall mortality compared with those with lower sTNF-RII levels, whereas among nonregular aspirin users the adjusted HR was 2.26 (95% CI 1.23–4.01, P for interaction=0.53).

Conclusions:

Among CRC patients, higher sTNF-RII levels are associated with a significant increase in overall mortality, but not CRC-specific mortality. The role of inflammation and anti-inflammatory medications in survival of CRC patients warrants further exploration.

IL-1β induced RXRα overexpression through activation of NF-κB signaling in gastric carcinoma

BACKGROUND

Abnormal expression of Retinoid X Receptor α (RXRα) seems to be a frequent incident in a variety of cancers. However, the expression pattern and the mechanisms in gastric carcinoma (GC) remain unclear.

METHODS

In GC tissues and cell lines, the expression levels of RXRα mRNA and protein were detected by Q-PCR and Western blot, respectively; the localization of RXRα was evaluated by immunohistochemistry (IHC) or immunocytochemistry (ICC). The effect of IL-1β on RXRα expression and localization was detected by Western blot and ICC. Nuclear factor-κB (NF-κB) pathway was assessed via Western blot.

RESULTS

RXRα expression was markedly elevated at both mRNA and protein levels in GC tissues and cell lines (all P<0.05). The abnormal overexpression of RXRα was predominantly visualized in cytoplasm. IL-1β significantly induced cytoplasmic expression of RXRα in a time-dependent manner. Co-incubation with IL-1β enhanced phospho-IKKα (p-IKKα) expression and this effect could be inhibited by the specific inhibitor for NF-κB (all P<0.01).

CONCLUSIONS

IL-1β upregulated RXRα through activation of NF-κB signaling and these suggested a possible clinic significance of retinoid receptor expression in the diagnosis and treatment of GC.

Increased Levels of NF-kB-Dependent Markers in Cancer-Associated Deep Venous Thrombosis

Several studies highlight the role of inflammatory markers in thrombosis as well as in cancer. However, their combined role in cancer-associated deep vein thrombosis (DVT) and the molecular mechanisms, involved in its pathophysiology, needs further investigations. In the present study, C-reactive protein, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1β), matrix metalloproteases-9 (MMP-9), vascular endothelial growth factor (VEGF), tissue factor (TF), fibrinogen and soluble P-selectin, were analyzed in plasma and in monocyte samples from 385 cancer patients, of whom 64 were concomitantly affected by DVT (+). All these markers were higher in cancer patients DVT+ than in those DVT-. Accordingly, significantly higher NF-kB activity was observed in cancer patients DVT+ than DVT-. Significant correlation between data obtained in plasma and monocyte samples was observed. NF-kB inhibition was associated with decreased levels of all molecules in both cancer DVT+ and DVT-. To further demonstrate the involvement of NF-kB activation by the above mentioned molecules, we treated monocyte derived from healthy donors with a pool of sera from cancer patients with and without DVT. These set of experiments further suggest the significant role played by some molecules, regulated by NF-kB, and detected in cancer patients with DVT. Our data support the notion that NF-kB may be considered as a therapeutic target for cancer patients, especially those complicated by DVT. Treatment with NF-kB inhibitors may represent a possible strategy to prevent or reduce the risk of DVT in cancer patients.

Expression and function of Toll-like receptors in peripheral blood mononuclear cells from patients with ovarian cancer

Inflammation has been implicated in the initiation and progression of ovarian cancer (OC), the underlying mechanisms of which are still unclear. We hypothesized that the abnormal expression of Toll-like receptors (TLRs), which were potential activators of nuclear factor-kappa B p65 (NF-κB p65), could promote inflammation and tumorigenesis in OC. In this study, we characterized the expression of TLRs in peripheral blood mononuclear cells (PBMCs) and found TLR2 and TLR6 mRNAs levels to be higher in PBMCs from OC patients than in those from benign disease (BC) or healthy normal controls (NC). Flow cytometry analysis showed that TLR1, TLR2 and TLR6 were highly expressed in monocytes from OC patients, but not in those from control subjects. Consistently, inflammatory cytokines interleukin (IL)-1β and IL-6 were up-regulated in PBMCs from OC patients upon stimulation with Pam3CSK4 (TLR1 ligand) and HKLM (TLR2 ligand), compared with unstimulated PBMCs. Stimulation of PBMCs with TLR ligands led to activation of downstream signaling molecules in TLRs (MyD88, TRAF6, TANK, NF-κB p65 and p-NF-κB p65). We also discovered that SK-OV-3-secreted factors were potent PBMCs activators, leading to the production of IL-1β, IL-6 and IL-8 through activation of TLRs and downstream signaling molecules in PBMCs. Before coculturing with SK-OV-3, pretreatment of THP-1 cells or PBMCs with monoclonal antibodies against TLR1, TLR2 or TLR6 inhibited the production of IL-1β and IL-6 and activation of MyD88, TRAF6, TANK, NF-κB p65 and p-NF-κB p65. Our results provided new evidence that TLR1, TLR2 and TLR6 signaling was linked with inflammation in OC microenvironment.

Upregulation of MAPK/Erk and PI3K/Akt pathways in ulcerative colitis-associated colon cancer

An extracellular signal like a cytokine or chemokine, secreted in the inflammatory microenvironment can activate the mitogen activated protein kinase (MAPK) pathway by binding to a cytokine receptor tyrosine kinase, which further activates tyrosine kinases such as Janus Kinase-3 (Jak-3). This signal is transferred from Jak-3 to the DNA in the nucleus of the cell by a chain of kinases, ultimately activating extracellular receptor kinase (Erk/MAPK). The latter phosphorylates c-myc, an oncogene, which alters the levels and activities of many transcription factors leading to cell survival, proliferation and invasion. The oncogenic PI3K pathway plays a similar role by activating c-myc, leading to cell survival and proliferation. The present study explores the role of ulcerative colitis in colon cancer by investigating the activities of tyrosine kinase activated MAPK pathway and various components of the PI3K pathway including PI3K, PTEN, PDK1, GSK3β, Akt, mTOR, Wnt and β-catenin. This was done by western blot and fluorescent immunohistochemical analysis of the above-mentioned proteins. Also, the morphological and histological investigation of the colonic samples from various animal groups revealed significant alterations as compared to the control in both inflammatory as well as carcinogenic conditions. These effects were reduced to a large extent by the co-administration of celecoxib, a second-generation non-steroidal anti-inflammatory drug (NSAID).