[Comparative metabolomics analysis of metabolic pathways in the high-yielding mutant strain of avilamycin].

Avilamycin (AVI) is an oligosaccharide antibiotic that has strong inhibitory effect on Gram-positive bacteria. It is widely used in livestock and poultry farming. However, the use of traditional breeding techniques and immature fermentation process have become the key factors limiting its commercialization. In this study, we used comparative metabolomics techniques to examine the difference in intracellular metabolism between a high-yield AVI mutant strain modified by ribosome engineering technology and the parental strain. GC-MS analysis was conducted on mycelia samples taken on days 4, 6, and 8 of fermentation, resulting in the detection of a total of 112 compounds. After comparison with the NIST library, 29 intracellular metabolites were accurately identified. Two-dimensional principal component analysis (PCA) revealed significant differences in metabolites between the mutant strain and the parental strain at different time points. Orthogonal partial least squares-discriminant analysis (OPLS-DA) identified 11 intracellular metabolites that were closely related to AVI biosynthesis. KEGG metabolic pathway enrichment analysis showed that avilamycin synthesis was closely related to carbohydrate metabolism and amino acid metabolism. Six key differential metabolites were selected: L-valine, L-serine, L-alanine, D-galactose, D-cellobiose, and D-glucose. Upregulation of these metabolites in the mutant strain enhanced its metabolic flow for AVI synthesis. After 8 days of fermentation, the mutant strain produced 76.86% more AVI than the parental strain. The findings of this study serve as reference for the future rational optimization of avilamycin fermentation.

Lactoferrin alleviates Western diet-induced cognitive impairment through the microbiome-gut-brain axis.

Lactoferrin (Lf) has been shown to benefit cognitive function in several animal models. To elucidate the underlying mechanisms, male C57BL/6J mice were randomly divided into the control (CON), Western-style diets (WD), lactoferrin (Lf), and Lf + antibiotics (AB) groups. The Lf group was intragastrically administered with Lf, and the Lf + AB group additionally drank a solution with antibiotics. After 16 weeks of intervention, Lf improved the cognitive function as indicated by behavioral tests. Lf also increased the length and curvature of postsynaptic density and upregulated the related protein expression, suggesting improved hippocampal neurons and synapses. Lf suppressed microglia activation and proliferation as revealed by immunofluorescence analysis. Lf decreased the serum levels of pro-inflammatory cytokines and downregulated their protein expressions in the hippocampus region. Lf also inhibited the activation of NF-κB/NLRP3 inflammasomes in the hippocampus. Meanwhile, Lf upregulated the expression of tight junction proteins, and increased the abundance of Bacteroidetes at phylum and Roseburia at genus, which are beneficial for gut barrier and cognitive function. The antibiotics eliminated the effects of long-term Lf intervention on cognitive impairment in the Lf + AB group, suggesting that gut microbiota participated in Lf action. Short-term Lf intervention (2 weeks) prevented WD-induced gut microbiota alteration without inducing behavioral changes, supporting the timing sequence of gut microbiota to the brain. Thus, Lf intervention alleviated cognitive impairment by inhibiting microglial activation and neuroinflammation through the microbiome-gut-brain axis.

Correction to: Amelioration of radiation­induced liver damage by p-coumaric acid in mice.

[This corrects the article DOI: 10.1007/s10068-022-01118-8.].

P4HA1 activates HMGCS1 to promote nasopharyngeal carcinoma ferroptosis resistance and progression.

Ferroptosis is a novel type of iron-dependent regulatory cell death. To date, the regulatory mechanism of ferroptosis in nasopharyngeal carcinoma (NPC) remains poorly understood. In this study, we found that the prolyl 4-hydroxylase (P4H) subunit P4HA1 protects NPC cells from erastin-induced ferroptosis by activating HMGCS1, a key enzyme in the mevalonate pathway. We also found that the P4HA1/HMGCS1 axis promoted NPC cell proliferation in vitro. In vivo, downregulation of the P4HA1/HMGCS1 axis inhibited the growth of NPC cell xenografts and enhanced the inhibitory effect of erastin on tumor growth. Extracellular matrix (ECM) detachment is an important trigger for ferroptosis. We found that the P4HA1/HMGCS1 axis promoted the ferroptosis resistance and survival of ECM-detached NPC cells. In vivo, downregulation of the P4HA1/HMGCS1 axis inhibited the lung colonization of NPC cells and enhanced the inhibitory effect of erastin on NPC lung metastasis. Moreover, the high expression of P4HA1 predicted a poor prognosis and served as a potential independent prognostic factor in patients with NPC. In conclusion, P4HA1 is a novel molecular marker of NPC ferroptosis resistance and a poor prognosis, and the P4HA1/HMGCS1 axis provides a new target for the treatment of NPC progression.

Protective effect and mechanism of lactoferrin combined with hypoxia against high-fat diet induced obesity and non-alcoholic fatty liver disease in mice.

Obesity is a global epidemic, it can induce glucose and lipid metabolism disorder and non-alcoholic fatty liver disease (NAFLD). This study explored a new way to control weight and improve fatty liver, namely, living in hypoxia environment and supplement with lactoferrin (Lf). Sixty male C57BL/6J mice were divided into six groups, namely, control, hypoxia, high-fat diet, hypoxia + high-fat diet, hypoxia + high-fat diet + low dose Lf intervention, and hypoxia + high-fat diet + high-dose Lf intervention. Mice in the hypoxia treatment groups were treated with approximately 11.5 % oxygen for 6 h every day for 8 weeks. Results showed that interventions combining Lf and hypoxia treatments showed better effect against obesity and NAFLD than hypoxia treatment alone. The interventions controlled weight gain in mice, improved glucolipid metabolism in mice. The combination intervention reduced cholesterol absorption by reducing the level of hydrophobic bile acids, and elevating the level of hydrophilic bile acids. Gut microbiota analysis revealed that the combination intervention considerably elevated short chain fatty acids (SCFAs)-producing bacteria level, and reduced the Desulfovibrionaceae_unclassified level. Thus, Lf combined with hypoxia intervention effectively prevents obesity and NAFLD by restoring gut microbiota composition and bile acid profile.

CAPRIN2 upregulation by LINC00941 promotes nasopharyngeal carcinoma ferroptosis resistance and metastatic colonization through HMGCR.

Distant metastasis is the main cause of death in nasopharyngeal carcinoma (NPC) patients. There is an urgent need to reveal the underlying mechanism of NPC metastasis and identify novel therapeutic targets. The ferroptosis resistance and survival ability of extracellular matrix (ECM)-detached tumor cells are important factors in determining the success of distant metastasis. In this study, we found that CAPRIN2 contributes to the ferroptosis resistance and survival of ECM-detached NPC cells. Moreover, CAPRIN2 serves as a positive regulator of NPC cell migration and invasion. HMGCR, the key metabolic enzyme of the mevalonate pathway, was identified as the key downstream molecule of CAPRIN2, which mediates its regulation of ferroptosis, survival, migration and invasion of NPC cells. Lung colonization experiments showed that downregulation of the CAPRIN2/HMGCR axis resulted in reduced lung metastasis of NPC cells. Erastin treatment inhibited the ability of NPC cells to colonize the lungs, which was further enhanced by CAPRIN2/HMGCR axis downregulation. Regulated by upstream LINC00941, CAPRIN2 is abnormally activated in NPC, and its high expression is associated with a poor prognosis. In conclusion, CAPRIN2 is a molecular marker of a poor prognosis in NPC, and the LINC00941/CAPRIN2/HMGCR axis provides a new target for the treatment of NPC metastasis and ferroptosis resistance.

Amelioration of radiation-induced liver damage by p-coumaric acid in mice.

Radiation-induced liver damage (RILD) is a spiny problem in radiotherapy or other circumstances that exposure to radiation. The need for radioprotective agent is increasing to protect liver tissue. This study aimed to explore the hepatoprotective effect of p-coumaric acid (CA) against RILD. C57BL/6 male mice were exposed to 4 Gy irradiation and administrated with CA for 4 days starting on the same day of irradiation. Mice were sacrificed to obtain blood and liver tissues on day 3.5 or 14 post irradiation, respectively. The blood and liver tissues were collected. As compared with the only irradiated group, CA supplementation improved liver morphology, decreased serum alanine aminotransferase and aspartate aminotransferase, inhibited BCL2-associated X (BAX) protein expression, and improved the mice hematopoietic function. CA at the dose of 100 mg/kg body weight showed better effect compared to the other doses. Thus, CA might possess potential to protect against RILD.

CDC27-ODC1 Axis Promotes Metastasis, Accelerates Ferroptosis and Predicts Poor Prognosis in Neuroblastoma.

Neuroblastoma (NB) is a devastating malignancy threatening children's health, and amplification of MYCN is associated with treatment failure and a poor outcome. Here, we aimed to demonstrate the role of cell division cycle 27 (CDC27), an important core subunit of the anaphase-promoting complex, and its clinical significance in NB patients. In functional assays, we illustrated that CDC27 promoted the cell growth, metastasis and sphere-formation ability of NB cells both in vitro and in vivo. To further understand the potential mechanism, SK-N-SH cells were transfected with CDC27 siRNA, and RNA-sequencing was performed. The results revealed that downregulation of CDC27 led to markedly reduced expression of ODC1, which is a well-established direct target of MYCN. Subsequently, we further illustrated that suppression of ODC1 significantly attenuated the promotion effect of CDC27 on the proliferation, metastasis, and sphere-formation ability of NB cells, hinting that CDC27 exerted its biological behavior in NB at least partly in an ODC1-dependent manner. In addition, CDC27 rendered cells more vulnerable to ferroptosis, while knockdown of ODC1 markedly reversed the pro-ferroptotic effect of CDC27. Collectively, our data is the first to report that the CDC27/ODC1 axis promotes tumorigenesis and acts as a positive regulator of ferroptosis in NB, highlighting that CDC27 may represent a novel therapeutic strategy and prognostic biomarker in neuroblastoma.

Associations of rs524952 and rs634990 gene polymorphisms in 15q14 with high myopia: A meta-analysis.

Purpose: Many studies have been conducted to investigate the association between the rs524952 and rs634990 polymorphisms and high myopia (HM). However, the results were conflicting. Thus, a meta-analysis was needed to reveal the real association between the two single nucleotide polymorphisms (SNPs) and HM. Methods: All eligible studies published in Pubmed, Embase, China Biologic Medicine (CBM), the China National Knowledge Infrastructure (CNKI), the Cochrane Library, and the Web of Science from 2010 to March 2019 were examined. Results: Six comparison groups in four studies with 5,293 subjects for the rs524952 polymorphism and five studies with 6,750 subjects for the rs634990 polymorphism were included. No statistically significant associations were observed between the rs524952 and rs634990 polymorphisms and HM under the allelic model, recessive genetic model, and dominant genetic model in this meta-analysis. Subgroup analysis was conducted by dividing the studies into two groups according to the case sample size, which showed that the association between the rs524952 polymorphism and HM was found only in a subgroup of fewer than 300 cases under the dominant genetic model (OR=0.64; 95% confidence interval [CI]:0.43-0.96). Sensitivity analysis for the rs524952 polymorphism suggested the results of this study were stable under all the genetic models. However, the association between the rs634990 polymorphism and HM turned out to be statistically significant in the allelic, recessive, and dominant genetic models after the omission of Qiang et al.'s study. No publication bias was found. Conclusions: The results of this meta-analysis suggested the rs524952 and rs634990 polymorphisms may have nothing to do with the development of HM. The present results must be confirmed with larger-scale studies in the future.

Exome sequencing reveals the genetic landscape and frequent inactivation of PCDHB3 in Chinese rectal cancers.

Colorectal cancer (CRC) is the third most common cancer worldwide, with more than 1.3 million new cases and 690 000 deaths each year. In China, the incidence of CRC has increased dramatically due to dietary and lifestyle changes, to become the fifth leading cause of cancer-related death. Here, we performed whole-exome sequencing in 50 rectal cancer cases among the Chinese population as part of the International Cancer Genome Consortium research project. Frequently mutated genes and enriched pathways were identified. Moreover, a previously unreported gene, PCDHB3, was found frequently mutated in 5.19% cases. Additionally, PCDHB3 expression was found decreased in 81.6% of CRC tissues and all eight CRC cell lines tested. Low expression and cytoplasmic localization of PCDHB3 predict poor prognosis in advanced CRC. Copy number decrease and/or CpG island hypermethylation contributes to the pervasive decreased expression of PCDHB3. PCDHB3 inhibits CRC cell proliferation, migration, and epithelial-mesenchymal transition. The tumor-suppressive effects of PCDHB3 are partially due to inhibition of NF-κB transcriptional activity through K63 deubiquitination of p50 at lysine 244/252, which increases the binding affinity of inactive p50 homodimer to κB DNA, resulting in competitive inhibition of the transcription of NF-κB target genes by p65 dimers. Our study identified PCDHB3 as a novel tumor suppressor in CRC via inhibition of the NF-κB pathway, and its expression and localization may serve as prognostic markers for advanced CRC. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

SUV39H2 promotes colorectal cancer proliferation and metastasis via tri-methylation of the SLIT1 promoter.

Suppressor of variegation 3-9 homolog 2 (SUV39H2) is a member of the SUV39H subfamily of lysine methyltransferases. Its role in colorectal cancer (CRC) proliferation and metastasis has remained unexplored. Here, we determined that SUV39H2 was upregulated in CRC tissues compared with that in adjacent non-neoplastic tissues. Further statistical analysis revealed that high SUV39H2 expression was strongly associated with distant metastasis (P = 0.016) and TNM stage (P = 0.038) and predicted a shorter overall survival (OS; P = 0.018) and progression-free survival (PFS; P = 0.018) time for CRC patients. Both in vitro and in vivo assays demonstrated that ectopically expressed SUV39H2 enhanced CRC proliferation and metastasis, while SUV39H2 knockdown inhibited CRC proliferation and metastasis. A molecular screen of SUV39H2 targets found that SUV39H2 negatively regulated the expression of SLIT guidance ligand 1 (SLIT1). Moreover, rescue assays suggested that SLIT1 could antagonize the function of SUV39H2 in CRC. Mechanistic studies indicated that SUV39H2 can directly bind to the SLIT1 promoter, suppressing SLIT1 transcription by catalyzing histone H3 lysine 9 (H3K9) tri-methylation. In summary, we propose that SUV39H2 can predict CRC patient prognosis and stimulate CRC malignant phenotypes via SLIT1 promoter tri-methylation.

Long Noncoding RNA BC032913 as a Novel Therapeutic Target for Colorectal Cancer that Suppresses Metastasis by Upregulating TIMP3.

Long noncoding RNAs (lncRNAs) have been shown to play critical roles in the biology of various cancers. However, their expression patterns and biological functions in human colorectal cancer (CRC) remain largely unknown. The aim of this study was to explore lncRNA profiles in CRC and investigate key lncRNAs involved in CRC tumorigenesis and progression. The microarray data of six CRC and matched non-cancerous tissues revealed distinct lncRNA profiles, including 899 upregulated and 1,646 downregulated lncRNAs (p < 0.05, fold change > 2.0). Furthermore, we found that the lncRNA BC032913 was generally underexpressed in 115 CRC samples compared with normal tissues. Reduced BC032913 levels were significantly associated with an advanced tumor, lymph nodes, distant metastasis (TNM) stage and a higher risk of lymph node and distant metastases. BC032913 downregulation indicated poor overall survival in CRC patients. Moreover, BC032913 enhanced the mRNA and protein expression of TIMP3 and inhibited Wnt/ß-catenin pathway activity, thus suppressing CRC metastasis in vitro and in vivo. Collectively, the obtained data show that BC032913 plays an inhibitory role in CRC aggression by upregulating TIMP3, followed by inactivation of the Wnt/ß-catenin pathway. Our findings indicate that the novel lncRNA BC032913 could serve as a novel prognostic marker and effective therapeutic target for CRC.

CDC27 Induces Metastasis and Invasion in Colorectal Cancer via the Promotion of Epithelial-To-Mesenchymal Transition.

Distant metastasis is the primary cause of cancer-related death among patients with colorectal cancer (CRC), and the discovery of novel therapeutic targets by further exploring the molecular mechanisms of CRC metastasis is therefore urgently needed. We previously illustrated that CDC27 overexpression promoted proliferation in CRC, but no studies have emphasized the role of CDC27 in cancer metastasis thus far. Our previous data indicated that the expression of CDC27 was significantly associated with distant metastasis in patient tissues, and therefore, in this study, we focused on the investigation of the potential mechanisms of CDC27 in CRC metastasis. The results revealed that CDC27 promoted the metastasis, invasion and sphere-formation capacity of DLD1 cells, but that the inhibition of CDC27 in HCT116 cells suppressed metastasis both in vitro and in vivo. Mechanistic analyses revealed that CDC27 promoted epithelial-to-mesenchymal transition (EMT), as demonstrated by the reduced expression of the epithelial markers ZO-1 and E-cadherin and the enhanced expression of the mesenchymal markers ZEB1 and Snail in HCT116 and DLD1 cells. Further mechanistic investigation indicated that CDC27 promoted metastasis and sphere-formation capacity in an ID1-dependent manner. In conclusion, we first demonstrated the role of CDC27 in cancer metastasis and showed that CDC27 may serve as a promising therapeutic target for CRC.

Synthetic lethal short hairpin RNA screening reveals that ring finger protein 183 confers resistance to trametinib in colorectal cancer cells.

BACKGROUND: The mitogen-activated extracellular signal-regulated kinase 1/2 (MEK1/2) inhibitor trametinib has shown promising therapeutic effects on melanoma, but its efficacy on colorectal cancer (CRC) is limited. Synthetic lethality arises with a combination of two or more separate gene mutations that causes cell death, whereas individual mutations keep cells alive. This study aimed to identify the genes responsible for resistance to trametinib in CRC cells, using a synthetic lethal short hairpin RNA (shRNA) screening approach. METHODS: We infected HT29 cells with a pooled lentiviral shRNA library and applied next-generation sequencing to identify shRNAs with reduced abundance after 8-day treatment of 20 nmol/L trametinib. HCT116 and HT29 cells were used in validation studies. Stable ring finger protein 183 (RNF183)-overexpressing cell lines were generated by pcDNA4-myc/his-RNF183 transfection. Stable RNF183-knockdown cell lines were generated by infection of lentiviruses that express RNF183 shRNA, and small interference RNA (siRNA) was used to knock down RNF183 transiently. Quantitative real-time PCR was used to determine the mRNA expression. Western blotting, immunohistochemical analysis, and enzyme-linked immunosorbent assay (ELISA) were used to evaluate the protein abundance. MTT assay, colony formation assay, and subcutaneous xenograft tumor growth model were used to evaluate cell proliferation. RESULTS: In the primary screening, we found that the abundance of RNF183 shRNA was markedly reduced after treatment with trametinib. Trametinib induced the expression of RNF183, which conferred resistance to drug-induced cell growth repression and apoptotic and non-apoptotic cell deaths. Moreover, interleukin-8 (IL-8) was a downstream gene of RNF183 and was required for the function of RNF183 in facilitating cell growth. Additionally, elevated RNF183 expression partly reduced the inhibitory effect of trametinib on IL-8 expression. Finally, xenograft tumor model showed the synergism of RNF183 knockdown and trametinib in repressing the growth of CRC cells in vivo. CONCLUSION: The RNF183-IL-8 axis is responsible for the resistance of CRC cells to the MEK1/2 inhibitor trametinib and may serve as a candidate target for combined therapy for CRC.

RNF183 promotes proliferation and metastasis of colorectal cancer cells via activation of NF-κB-IL-8 axis.

Colorectal cancer (CRC) is one of the most common malignant tumors worldwide, which is a heterogeneous disease and main risk factors are associated with inflammation, family history, genetic mutations, epigenetics, and so on. Ring finger domain proteins have been reported involved in carcinogenesis, whereas their roles in CRC are rarely studied. Here, we reanalyzed the expression of 202 RNF family members in CRC using published microarray data from GEO database and found that RNF183 is markedly upregulated in tumor tissues. RNF183 high expression is significantly associated with tumor size (P=0.012), tumor invasive depth (P=0.004), TNM stage (P=0.01), and distant metastasis (P=0.009). CRC patients with high expression of RNF183 have poor overall survival (P<0.001) and progression-free survival (P<0.001). Functional studies suggest that RNF183 facilitates growth, migration, and invasion of CRC cells in vitro and promotes tumor proliferation and metastasis in vivo. Mechanistically, RNF183 activates NF-κB signal pathway through P65 and stimulates the transcription of multifunctional chemokine IL-8. Blockage of NF-κB by small molecule inhibitor or depletion of IL-8 by siRNA attenuates the function of RNF183 to promote cell migration. Moreover, the regulation of RNF183 on IL-8 transcription and cell viability/motility is dependent on its E3 ubiquitin ligase activity. Our study provided proof of principle to show that RNF183 promotes proliferation and metastasis of CRC cells via activation of NF-κB-IL-8 axis.

PI3K/AKT-mediated upregulation of WDR5 promotes colorectal cancer metastasis by directly targeting ZNF407.

Colorectal cancer (CRC) is the third most common cause of cancer deaths, and has a high rate of liver and lung metastasis. Unfortunately, distant metastasis is the main barrier for advanced CRC therapy and leads to a very low survival rate. In this study, we identified WDR5, a vital factor that regulates vertebrate development and cell self-renewal and reprogramming, as a novel prognostic marker and therapeutic target for CRC patients. We demonstrate that WDR5 is upregulated in CRC tissues and promotes CRC metastasis both in vitro and in vivo. In an effort to investigate the impact of WDR5 on CRC cell fate, we treated CRC cells with growth factor and inhibitor. We report that WDR5 is a novel factor in the metastasis of CRC by triggering epithelial-mesenchymal transition (EMT) process in response to the PI3K/AKT signaling pathway. Moreover, WDR5 shows a direct binding to the ZNF407 promoter on regulating cellular EMT process, leading to CRC metastasis. Hence, our findings strongly position WDR5 as a valuable marker for CRC, and inhibiting WDR5 or the associated signaling pathways may be an effective strategy for the future development of anti-CRC therapy.

The loss-of-function mutations and down-regulated expression of ASB3 gene promote the growth and metastasis of colorectal cancer cells.

BACKGROUND: Ankyrin repeat and SOCS box protein 3 (ASB3) is a member of ASB family and contains ankyrin repeat sequence and SOCS box domain. Previous studies indicated that it mediates the ubiquitination and degradation of tumor necrosis factor receptor 2 and is likely involved in inflammatory responses. However, its effects on oncogenesis are unclear. This study aimed to investigate the effects of ASB3 on the growth and metastasis of colorectal cancer (CRC). METHODS: We used next-generation sequencing or Sanger sequencing to detect ASB3 mutations in CRC specimens or cell lines, and used real-time quantitative polymerase chain reaction, Western blotting, and immunohistochemical or immunofluorescence assay to determine gene expression. We evaluated cell proliferation by MTT and colony formation assays, tested cell cycle distribution by flow cytometry, and assessed cell migration and invasion by transwell and wound healing assays. We also performed nude mouse experiments to evaluate tumorigenicity and hepatic metastasis potential of tumor cells. RESULTS: We found that ASB3 gene was frequently mutated (5.3%) and down-regulated (70.4%) in CRC cases. Knockdown of endogenous ASB3 expression promoted CRC cell proliferation, migration, and invasion in vitro and facilitated tumorigenicity and hepatic metastasis in vivo. Conversely, the ectopic overexpression of wild-type ASB3, but not that of ASB3 mutants that occurred in clinical CRC tissues, inhibited tumor growth and metastasis. Further analysis showed that ASB3 inhibited CRC metastasis likely by retarding epithelial-mesenchymal transition, which was characterized by the up-regulation of ß-catenin and E-cadherin and the down-regulation of transcription factor 8, N-cadherin, and vimentin. CONCLUSION: ASB3 dysfunction resulted from gene mutations or down-regulated expression frequently exists in CRC and likely plays a key role in the pathogenesis and progression of CRC.

Minicircle-oriP-miR-31 as a Novel EBNA1-Specific miRNA Therapy Approach for Nasopharyngeal Carcinoma.

MicroRNAs (miRNAs) are important post-transcriptional regulators that control cancer development and progression. However, the application of miRNA therapy in cancer has been hampered by a lack of an efficient and targeted delivery system. In our previous studies, an oriP promoter-based minicircle system successfully mediated targeted foreign gene expression in EBNA1-positive nasopharyngeal carcinoma (NPC). However, it remains to be evaluated whether this system can be applied for tumor miRNA therapy. miR-31-5p, a tumor suppressive miRNA involved in the tumorigenesis of EBV-positive NPC, was selected as the therapeutic miRNA to be transferred. In this work, we constructed a novel EBNA1-specific miRNA expression system, minicircle-oriP-miR-31. The results indicated that mc-oriP-miR-31 mediated selective miR-31-5p expression in EBNA1-positive NPC cells. Both the proliferation and migration of EBNA1-positive NPC cell lines were inhibited by mc-oriP-miR-31 treatment in vitro. Furthermore, mc-oriP-miR-31 treatment inhibited xenograft growth and lung metastasis in vivo. We also identified WDR5 as a novel miR-31-5p target. Knockdown of WDR5 inhibited NPC cell proliferation and migration and was associated with downregulation of Notch1. Reintroduction of WDR5 partially abrogated the suppressive effects induced by miR-31-5p. In conclusion, we demonstrate for the first time that targeted expression of miR-31-5p using a nonviral minicircle vector can serve as a novel approach for tumor miRNA therapy. Moreover, WDR5 may be a promising therapeutic target for NPC treatment.

IL-17 induces antitumor immunity by promoting beneficial neutrophil recruitment and activation in esophageal squamous cell carcinoma.

Interleukin (IL)-17 has been reported to play a controversial role in tumor immunity. Our previous studies showed that infiltration of IL-17-producing cells in esophageal squamous cell carcinoma (ESCC) induced tumor protective immunity by recruiting CD8+T lymphocytes, natural killer (NK) cells, and B lymphocytes into the tumor microenvironment. However, the mechanism of IL-17 regulation of tumor-associated neutrophils remains elusive in ESCC. In this study, we therefore evaluated the accumulation of myeloperoxidase (MPO)+ neutrophils and its association with IL-17-producing cells within ESCC tumor nests. We also investigated the effects of IL-17 on the recruitment and antitumor activity of neutrophils. MPO+ neutrophil infiltration was found to predict a favorable prognosis in ESCC patients and was positively correlated with IL-17+ cell density. IL-17 stimulated ESCC tumor cells to release more of the CXC chemokines CXCL2 and CXCL3, which are involved in neutrophil migration. Furthermore, IL-17 potentiates the direct killing capability of neutrophils by enhancing the production of cytotoxic molecules, including reactive oxygen species (ROS), MPO, TNF-related apoptosis-inducing ligand (TRAIL), and IFN-γ. Experiments in mice suggested that IL-17 alone might not affect tumor progression in the tumor-bearing host, but IL-17 can inhibit tumor growth by promoting beneficial neutrophil infiltration and activation at tumor sites. As emerging evidence indicates that targeting tumor-associated neutrophils is a strategy for antitumor therapy, our findings reveal a positive contribution of IL-17 to the modulation of neutrophil-mediated antitumor immunity in ESCC. This study provides further understanding of the mechanisms that selectively regulate functional activities of neutrophils, which may be critical for developing new tumor immunotherapy.

Olfactomedin 1 negatively regulates NF-κB signalling and suppresses the growth and metastasis of colorectal cancer cells.

Uncontrolled growth and distant metastasis are hallmarks of colorectal cancer (CRC), but the mechanisms are poorly understood. Olfactomedin 1 (OLFM1), a member of the olfactomedin domain-containing protein family, plays an important role in the development of neurogenic tissues. Recently, OLFM1 deregulation was frequently observed in several cancers, and it was induced in colon cell lines after treatment with the demethylating agent 5-aza-2'-deoxycytidine. However, the function of OLFM1 in CRC remains unknown. In this study, we reanalysed published microarray data and found that OLFM1 was significantly down-regulated in primary CRC samples compared to adjacent non-cancerous tissues. The results of immunohistochemistry indicated that decreased OLFM1 expression was significantly associated with lymph node status (p = 0.023), distant metastasis (p < 0.001), and AJCC/TNM stage (p = 0.013), and CRC patients with low OLFM1 expression had consistently poor overall survival (OS; p < 0.001) and progression-free survival (PFS; p < 0.001). Further analysis demonstrated that OLFM1 was epigenetically silenced in CRC tissues and cell lines via promoter hypermethylation. Overexpression and knockdown of OLFM1 attenuated and increased, respectively, CRC cells' proliferation, migration, and invasion in vitro and metastasis to the lung and liver in vivo. Mechanistically, the promotion of growth and metastasis of CRC cells by silencing of OLFM1 was associated with the activation of the non-canonical NF-κB signalling pathway. OLFM1 interacted with NF-κB-inducing kinase (NIK; MAP3K14) and repressed the phosphorylation of its downstream substrate Ikappa B kinase alpha (IKKα). OLFM1 expression was negatively correlated with the phosphorylation level of IKKα in CRC tissue samples. Knockdown of NIK impaired the ability of OLFM1 to repress NF-κB signalling, cell growth or migration. Thus, OLFM1 may be a valuable biomarker and therapeutic target for CRC patients. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.