NLRC3 regulates cellular proliferation and apoptosis to attenuate the development of colorectal cancer

The correlation of NLRC3 expression with the progression and prognosis of hepatocellular carcinoma

NLRC3 is a member of the nucleotide-binding domain and leucine-rich repeat (NLR) family protein that plays a role in inflammation and immunity. Although chronic inflammation has been identified as a hallmark of cancer, NLRC3 expression correlation with the development and prognosis of hepatocellular carcinoma (HCC) is unclear. In the present study, we first used Oncomine and OncoLnc database to determine the clinical significance of NLRC3 in HCC. Then we performed quantitative real-time polymerase chain reaction, Western blot, and immunohistochemical staining (IHC) and analyzed the correlation between NLRC3 expression and clinicopathological features of HCC in a Chinese population. We found that high levels of NLRC3 messenger RNA (mRNA) correlated with a favorable clinical outcome; furthermore, expression of NLRC3 was significantly reduced in the cancer tissue in patients compared with noncancerous hepatic tissues. NLRC3 reduction was correlated with Edmondson grade and metastasis. Kaplan-Meier survival analysis revealed that HCC patients with high expression of NLRC3 have a more favorable prognosis compared with those with low expression of NLRC3. We then used short hairpin RNA to knock down NLRC3 expression in HCC cell lines and evaluated its effect on cell proliferation and apoptosis. Suppression of NLRC3 expression promoted cell proliferation and inhibited apoptosis in vitro. Genomic analysis of the OncoLnc database also showed that NLRC3 mRNA level was directly correlated with mRNA levels of inflammasome components caspase-1, IL-1β, and IL-18. Based on our present study, down-regulated expression of NLRC3 may play an important role in cancer progression and prognosis of HCC by acting as a tumor suppressor.

Inflammatory cell death in intestinal pathologies

The intestinal tract is a site of intense immune cell activity that is poised to mount an effective response against a pathogen and yet maintain tolerance toward commensal bacteria and innocuous dietary antigens. The role of cell death in gut pathologies is particularly important as the intestinal epithelium undergoes self-renewal every 4-7 days through a continuous process of cell death and cell division. Cell death is also required for removal of infected, damaged, and cancerous cells. Certain forms of cell death trigger inflammation through release of damage-associated molecular patterns. Further, molecules involved in cell death decisions also moonlight as critical nodes in immune signaling. The manner of cell death is, therefore, highly instructive of the immunological consequences that ensue. Perturbations in cell death pathways can impact the regulation of the immune system with deleterious consequences. In this review, we discuss the various forms of cell death with a special emphasis on lytic cell death pathways of pyroptosis and necroptosis and their implications in inflammation and cancer in the gut. Understanding the implications of distinct cell death pathways will help in the development of therapeutic interventions in intestinal pathologies.

Nucleotide-Binding Domain Leucine-Rich Repeat Containing Proteins and Intestinal Microbiota: Pivotal Players in Colitis and Colitis-Associated Cancer Development

The nucleotide-binding domain leucine-rich repeat containing (NLR) proteins play a fundamental role in innate immunity and intestinal tissue repair. A dysbiotic intestinal microbiota, developed as a consequence of alterations in NLR proteins, has recently emerged as a crucial hit for the development of ulcerative colitis (UC) and colitis-associated cancer (CAC). The concept of the existence of functional axes interconnecting bacteria with NLR proteins in a causal role in intestinal inflammation and CAC aroused a great interest for the potential development of preventive and therapeutic strategies against UC and CAC. However, the most recent scientific evidence, which highlights many confounding factors in studies based on microbiota characterization, underlines the need for an in-depth reconsideration of the data obtained until now. The purpose of this review is to discuss the recent findings concerning the cross talk between the NLR signaling and the intestinal microbiota in UC and CAC development, and to highlight the open issues that should be explored and addressed in future studies.

Erzhi Pill® Protected Experimental Liver Injury Against Apoptosis via the PI3K/Akt/Raptor/Rictor Pathway

Erzhi Pill (EZP) is one of the basic prescriptions for treating liver diseases in traditional Chinese medicine. However, its mechanism of action is still undefined. The PI3K/AKT/Raptor/Rictor signaling pathway is closely related to apoptosis and plays a significant role in the pathogenesis of liver disease. To define the mechanism of the hepatoprotective effect of EZP in the treatment of liver disease, hepatic injury induced by 2-acetylaminofluorene/partial hepatectomy was treated by EZP for 14 days. The therapeutic effect of EZP was confirmed by the decreased production of aspartate aminotransferase and alanine aminotransferase, recovery of pathological liver injury, followed by inhibition of pro-inflammatory cytokines and transforming growth factor-β1. Bromodeoxyuridine assay and TUNEL staining indicated that apoptosis was suppressed and the numbers of cells in S phase and G0/G1phase were decreased. The crucial proteins in the PI3K/AKT/Raptor/Rictor signaling pathway were deactivated in rats with experimental liver injury treated by EZP. These results indicated that the hepatoprotective effect of EZP via inhibition of hepatocyte apoptosis was closely related to repression of the PI3K/Akt/Raptor/Rictor signaling pathway.

Pyrin Inflammasome Regulates Tight Junction Integrity to Restrict Colitis and Tumorigenesis

BACKGROUND & AIMS

Inflammatory bowel diseases (IBD) increase risk for colorectal cancer. Mutations in the Mediterranean fever gene (MEFV or pyrin) are associated with hereditary autoinflammatory disease and severe IBD. Expression of MEFV, a sensor protein that the initiates assembly of the inflammasome complex, is increased in colon biopsies from patients with IBD. We investigated the role of pyrin in intestinal homeostasis in mice.

METHODS

Mefv-/- mice and C57/BL6 mice (controls) were given azoxymethane followed by multiple rounds of dextran sodium sulfate (DSS) to induce colitis and tumorigenesis. In some experiments, Mefv-/- mice were given injections of recombinant interleukin 18 (rIL18) or saline (control) during DSS administration. Colon tissues were collected at different time points during colitis development and analyzed by histology, immunohistochemistry, immunoblots, or ELISAs (to measure cytokines). Spleen and mesenteric lymph node were collected, processed, and analyzed by flow cytometry. Colon epithelial permeability was measured in mice with colitis by gavage of fluorescent dextran and quantification of serum levels.

RESULTS

MEFV was expressed in colons of control mice and expression increased during chronic and acute inflammation; high levels were detected in colon tumor and adjacent non-tumor tissues. Mefv-/- mice developed more severe colitis than control mice, with a greater extent of epithelial hyperplasia and a larger tumor burden. Levels of inflammatory cytokines (IL6) and chemokines were significantly higher in colons of Mefv-/- mice than control mice following colitis induction, whereas the level IL18, which depends on the inflammasome for maturation and release, was significantly lower in colons of Mefv-/- mice. Mefv-/- mice had increased epithelial permeability following administration of DSS than control mice, and loss of the tight junction proteins occludin and claudin-2 from intercellular junctions. STAT3 was activated (phosphorylated) in inflamed colon tissues from Mefv-/-, which also had increased expression of stem cell markers (OLFM4, BMI1, and MSI1) compared with colons from control mice. Administration of rIL18 to Mefv-/- mice reduced epithelial permeability, intestinal inflammation, the severity of colitis, and colon tumorigenesis.

CONCLUSIONS

In studies with DSS-induced colitis, we found that pyrin (MEFV) is required for inflammasome activation and IL18 maturation, which promote intestinal barrier integrity and prevent colon inflammation and tumorigenesis. Strategies to increase activity of MEFV or IL18 might be developed for the treatment of IBD and prevention of colitis-associated tumorigenesis.

Rosmarinic Acid Activates AMPK to Inhibit Metastasis of Colorectal Cancer

Rosmarinic acid (RA) has been used as an anti-inflammatory, anti-diabetic, and anti-cancer agent. Although RA has also been shown to exert an anti-metastatic effect, the mechanism of this effect has not been reported to be associated with AMP-activated protein kinase (AMPK). The aim of this study was to elucidate whether RA could inhibit the metastatic properties of colorectal cancer (CRC) cells via the phosphorylation of AMPK. RA inhibited the proliferation of CRC cells through the induction of cell cycle arrest and apoptosis. In several metastatic phenotypes of CRC cells, RA regulated epithelial-mesenchymal transition (EMT) through the upregulation of an epithelial marker, E-cadherin, and the downregulation of the mesenchymal markers, N-cadherin, snail, twist, vimentin, and slug. Invasion and migration of CRC cells were inhibited and expressions of matrix metalloproteinase (MMP)-2 and MMP-9 were decreased by RA treatment. Adhesion and adhesion molecules such as ICAM-1 and integrin β1 expressions were also reduced by RA treatment. In particular, the effects of RA on EMT and MMPs expressions were due to the activation of AMPK. Moreover, RA inhibited lung metastasis of CRC cells by activating AMPK in mouse model. Collectively, these results proved that RA could be potential therapeutic agent against metastasis of CRC.

Nuclear division cycle 80 promotes malignant progression and predicts clinical outcome in colorectal cancer

Colorectal cancer (CRC) is a common human malignancy worldwide and increasing studies have attributed its malignant progression to abnormal molecular changes in cancer cells. Nuclear division cycle 80 (NDC80) is a newly discovered oncoprotein that regulates cell proliferation and cycle in numerous malignancies. However, its clinical significance and biological role in CRC remain unclear. Therefore, in this study, we firstly analyze its expression in a retrospective cohort enrolling 224 CRC patients and find its overexpression is significantly correlated with advanced tumor stage and poor prognosis in CRC patients. In addition, our result reveals it is an independent adverse prognostic factor affecting CRC-specific and disease-free survival. The subgroup analysis indicates NDC80 expression can stratify the clinical outcome in stage II and III patients, but fails in stage I and IV patients. In cellular assays, we find knockdown of NDC80 dramatically inhibits the proliferative ability, apoptosis resistance, cell cycle progression, and clone formation of CRC cells in vitro. Using xenograft model, we further prove knockdown of NDC80 also inhibits the tumorigenic ability of CRC cells in vivo. Finally, the microarray analysis is utilized to preliminarily clarify the oncogenic molecular mechanisms regulated by NDC80 and the results suggest it may promote CRC progression partly by downregulating tumor suppressors such as dual specificity phosphatase 5 and Forkhead box O1. Taken together, our study provides novel evidences to support that NDC80 is not only a promising clinical biomarker but also a potential therapeutical target for CRC precise medicine.

Gleditsia Saponin C Induces A549 Cell Apoptosis via Caspase-Dependent Cascade and Suppresses Tumor Growth on Xenografts Tumor Animal Model

Saponins are natural compounds and possess the most promising anti-cancer function. Here, a saponin gleditsia saponin C (GSC), extracted from gleditsiae fructus abnormalis, could induce apoptosis of lung tumor cell line A549 via caspase dependent cascade and this effect could be prevented by the caspase inhibitors. In addition, GSC induced cell death companied with an increase ratio of Bax:Bcl-2 and inhibition of ERK and Akt signaling pathways. Meanwhile, GSC suppressed TNFα inducing NF-κB activation and increased the susceptibility of lung cancer cell to TNFα induced apoptosis. Furthermore, on mouse xenograft model, GSC significantly suppressed tumor growth and induced cancer cell apoptosis, which validated the anti-tumor effect of GSC. Based on these results, GSC might be a promising drug candidate of anti-lung cancer for its potential clinical applications.

Phytochemicals and PI3K Inhibitors in Cancer-An Insight

In today's world of modern medicine and novel therapies, cancer still remains to be one of the prime contributor to the death of people worldwide. The modern therapies improve condition of cancer patients and are effective in early stages of cancer but the advanced metastasized stage of cancer remains untreatable. Also most of the cancer therapies are expensive and are associated with adverse side effects. Thus, considering the current status of cancer treatment there is scope to search for efficient therapies which are cost-effective and are associated with lesser and milder side effects. Phytochemicals have been utilized for many decades to prevent and cure various ailments and current evidences indicate use of phytochemicals as an effective treatment for cancer. Hyperactivation of phosphoinositide 3-kinase (PI3K) signaling cascades is a common phenomenon in most types of cancers. Thus, natural substances targeting PI3K pathway can be of great therapeutic potential in the treatment of cancer patients. This chapter summarizes the updated research on plant-derived substances targeting PI3K pathway and the current status of their preclinical studies and clinical trials.

Novel insights into microbiome in colitis and colorectal cancer

PURPOSE OF REVIEW

Microbiota is a major player in the pathogenesis of inflammatory bowel diseases (IBD) and colorectal cancer (CRC). Here, we summarize the key advances achieved in the past 18 months (ending June 2017) toward a better understanding of the role of microbiota in colitis and CRC development.

RECENT FINDINGS

Accumulating evidence shows the essential role of intestinal barrier function (e.g. mucus, IgA, LCN2, LYPD8) in protecting against bacteria-induced inflammation and tumor development. Numerous signaling pathways (e.g. TLRs and NLRs), metabolites (e.g. indole, bile acids, retinoic acid) and small noncoding RNAs (e.g. miRNA) have been identified as key mediators regulating host-microbe interactions in the intestine. Novel microbial drivers of colitis and tumorigenesis (e.g. Alistipes finegoldii, Atopobium parvalum, Peptostreptococcus anaerobius) have been identified and their disease-promoting activities have been described.

SUMMARY

IBD-associated colorectal cancer results from a complex breakdown of communication between the host and its microbiota, involving barrier function, immune signaling and metabolites.

Antidiabetic Effect of Tibetan Medicine Tang-Kang-Fu-San in db/db Mice via Activation of PI3K/Akt and AMPK Pathways

This study was to investigate the anti-diabetic effects and molecular mechanisms of Tang-Kang-Fu-San (TKFS), a traditional Tibetan medicine, in treating type 2 diabetes mellitus of spontaneous diabetic db/db mice. Firstly HPLC fingerprint analysis was performed to gain the features of the chemical compositions of TKFS. Next different doses of TKFS (0.5 g/kg, 1.0 g/kg, and 2.0 g/kg) were administrated via oral gavage to db/db mice and their controls for 4 weeks. TKFS significantly lowered hyperglycemia and ameliorated insulin resistance (IR) in db/db mice, indicated by results from multiple tests, including fasting blood glucose test, intraperitoneal insulin and glucose tolerance tests, fasting serum insulin levels and homeostasis model assessment of IR analysis as well as histology of pancreas islets. TKFS also decreased concentrations of serum triglyceride, total and low-density lipoprotein cholesterol, even though it did not change the mouse body weights. Results from western blot and immunohistochemistry analysis indicated that TKFS reversed the down-regulation of p-Akt and p-AMPK, and increased the translocation of Glucose transporter type 4 in skeletal muscles of db/db mice. In all, TKFS had promising benefits in maintaining the glucose homeostasis and reducing IR. The underlying molecular mechanisms are related to promote Akt and AMPK activation and Glucose transporter type 4 translocation in skeletal muscles. Our work showed that multicomponent Tibetan medicine TKFS acted synergistically on multiple molecular targets and signaling pathways to treat type 2 diabetes mellitus.