SLC52A3 expression is activated by NF-κB p65/Rel-B and serves as a prognostic biomarker in esophageal cancer

A Golgi apparatus‑related subtype and risk signature predicts prognosis and evaluates immunotherapy response in gastric cancer

BACKGROUND

Gastric cancer (GC) remains a significant health burden, calling for the discovery of novel biomarkers. Golgi apparatus, a crucial cellular organelle involved in tumorigenesis, remains underexplored in GC research. A comprehensive understanding of its role and associated mechanisms is urgently needed.

MATERIALS AND METHODS

Utilizing the TCGA-STAD dataset as the training cohort and GSE84433 as the validation cohort, we explored potential associations between Golgi apparatus-related genes (GARG) and GC clinical risk. We aimed to decipher the prognostic significance and underlying biological mechanisms of these genes via consistent clustering, differential expression analysis, enrichment analyses, and immune infiltration profiling. To assess the relationship between risk stratification and survival outcomes, drug sensitivity, and immune infiltration, we developed the Golgi Apparatus-Related Risk Signature (GARRS). The reliability of GARRS was further corroborated using immunohistochemical staining.

RESULTS

Consensus clustering based on 17 GARG identified two patient subgroups, C1 and C2, exhibiting differential survival, immune scores, and immune cell infiltration. We developed a GARRS using Cox-Lasso regression analysis, accurately stratifying patients into high- and low-risk groups. GARRS' validity was confirmed in the validation set and immunohistochemical staining. Our findings underline the Golgi apparatus' significance in the GC immune microenvironment and GARRS' utility in predicting GC survival outcomes.

CONCLUSION

This study underscores the association between Golgi apparatus subtypes and GC immunotumor microenvironment. GARRS, validated for its prognostic, immune infiltration, and drug sensitivity predictive abilities, offers new insights into gastric cancer treatment strategies.

Fluoride induces immunotoxicity by regulating riboflavin transport and metabolism partly through IL-17A in the spleen

The impairment of the immune system by fluoride is a public health concern worldwide, yet the underlying mechanism is unclear. Both riboflavin and IL-17A are closely related to immune function and regulate the testicular toxicity of fluoride. However, whether riboflavin or IL-17A is involved in fluoride-induced immunotoxicity is unknown. Here, we first established a male ICR mouse model by treating mice with sodium fluoride (NaF) (100 mg/L) via the drinking water for 91 days. The results showed that fluoride increased the expression of the proinflammatory factors IL-1β and IL-17A, which led to splenic inflammation and morphological injury. Moreover, the expression levels of the riboflavin transporters SLC52A2 and SLC52A3; the transformation-related enzymes RFK and FLAD1; and the key mitochondrial functional determinants SDH, COX, and ATP in the spleen were measured via real-time PCR, Western blotting, and ELISA. The results revealed that fluoride disrupted riboflavin transport, transformation, metabolism, and mitochondrial function. Furthermore, wild-type (WT) and IL-17A knockout (IL-17A-/-) C57BL/6 J male mice of the same age were treated with NaF (24 mg/kg·bw, equivalent to 100 mg/L) and/or riboflavin sodium phosphate (5 mg/kg·bw) via gavage for 91 days. Similar parameters were evaluated as above. The results confirmed that fluoride increased riboflavin metabolism through RFK but not through FLAD1. Fluoride also affected mitochondrial function and activated neutrophils (marked with Ly6g) and macrophages (marked with CD68) in the spleen. Interestingly, IL-17A partly mediated fluoride-induced riboflavin metabolism disorder and immunotoxicity in the spleen. This work not only reveals a novel toxic mechanism for fluoride but also provides new clues for exploring the physiological function of riboflavin and for diagnosing and treating the toxic effects of fluoride in the environment.

Exploring the impact of flavin homeostasis on cancer cell metabolism

Flavins and their associated proteins have recently emerged as compelling players in the landscape of cancer biology. Flavins, encompassing flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), serve as coenzymes in a multitude of cellular processes, such as metabolism, apoptosis, and cell proliferation. Their involvement in oxidative phosphorylation, redox homeostasis, and enzymatic reactions has long been recognized. However, recent research has unveiled an extended role for flavins in the context of cancer. In parallel, riboflavin transporters (RFVTs), FAD synthase (FADS), and riboflavin kinase (RFK) have gained prominence in cancer research. These proteins, responsible for riboflavin uptake, FAD biosynthesis, and FMN generation, are integral components of the cellular machinery that governs flavin homeostasis. Dysregulation in the expression/function of these proteins has been associated with various cancers, underscoring their potential as diagnostic markers, therapeutic targets, and key determinants of cancer cell behavior. This review embarks on a comprehensive exploration of the multifaceted role of flavins and of the flavoproteins involved in nucleus-mitochondria crosstalk in cancer. We journey through the influence of flavins on cancer cell energetics, the modulation of RFVTs in malignant transformation, the diagnostic and prognostic significance of FADS, and the implications of RFK in drug resistance and apoptosis. This review also underscores the potential of these molecules and processes as targets for novel diagnostic and therapeutic strategies, offering new avenues for the battle against this relentless disease.

Overexpression of PPM1B inhibited chemoresistance to temozolomide and proliferation in glioma cells

Protein phosphatase magnesium-dependent 1B (PPM1B) functions as IKKβ phosphatases to terminate nuclear factor kappa B (NF-κB) signaling. NF-κB signaling was constitutively activated in glioma cells. At present, little is known about the role of PPM1B in glioma. In the current study, we found that the expression of PPM1B was reduced in glioma tissues and cells, and decreased expression of PPM1B was related to poor overall survival of patients. Overexpression of PPM1B inhibited the proliferation and promoted apoptosis of glioma cells. Moreover, PPM1B overexpression reduced the phosphorylation of IKKβ and inhibited the nuclear localization of NF-κBp65. PDTC, an inhibitor of NF-κB signaling, reversed PPM1B-knockdown-induced cell proliferation. Furthermore, overexpression of PPM1B enhanced the sensitivity of glioma cells to temozolomide. In vivo experiments showed that overexpression of PPM1B could inhibit tumor growth, improve the survival rate of nude mice, and enhance the sensitivity to temozolomide. In conclusion, PPM1B suppressed glioma cell proliferation and the IKKβ-NF-κB signaling pathway, and enhanced temozolomide sensitivity of glioma cells.

Effect of Raltitrexed on ECA109 Cellular Radiosensitivity and its Mechanism in Esophageal Cancer

BACKGROUND

To investigate the effect of raltitrexed + X-ray irradiation on esophageal cancer ECA109 cells and analyze the potential action mechanism.

METHODS

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to analyze the inhibitory effect of raltitrexed on cell proliferation. The effect of raltitrexed on radiosensitivity was studied through a clone-forming experiment. The scratch assay and invasion test were performed to understand the cell migration and invasion abilities. The apoptosis rate change was measured using a flow cytometer, and Western Blotting was used to determine the expression of B cell lymphoma-2 (Bcl-2) and Bcl2-associated X protein (Bax) in each group.

RESULTS

Raltitrexed significantly inhibited ECA109 proliferation in a time-dose-dependent manner; there were significant differences among different concentrations and times of action. The results of the clone-forming experiment showed a sensitization enhancement ratio of 1.65, and this demonstrated a radiosensitization effect. After the combination of raltitrexed with X-ray, the cell migration distance was shortened, and the number of cells penetrating the membrane was reduced.

CONCLUSION

Raltitrexed can inhibit the growth of esophageal cancer ECA109 cells and has a radiosensitization effect.

Increased demand for FAD synthesis in differentiated and stem pancreatic cancer cells is accomplished by modulating FLAD1 gene expression: the inhibitory effect of Chicago Sky Blue

FLAD1, along with its FAD synthase (FADS, EC 2.7.7.2) product, is crucial for flavin homeostasis and, due to its role in the mitochondrial respiratory chain and nuclear epigenetics, is closely related to cellular metabolism. Therefore, it is not surprising that it could be correlated with cancer. To our knowledge, no previous study has investigated FLAD1 prognostic significance in pancreatic ductal adenocarcinoma (PDAC). Thus, in the present work, the FAD synthesis process was evaluated in two PDAC cell lines: (a) PANC-1- and PANC-1-derived cancer stem cells (CSCs), presenting the R273H mutation in the oncosuppressor p53, and (b) MiaPaca2 and MiaPaca2-derived CSCs, presenting the R248W mutation in p53. As a control, HPDE cells expressing wt-p53 were used. FADS expression/activity increase was found with malignancy and even more with stemness. An increased FAD synthesis rate in cancer cell lines is presumably demanded by the increase in the FAD-dependent lysine demethylase 1 protein amount as well as by the increased expression levels of the flavoprotein subunit of complex II of the mitochondrial respiratory chain, namely succinate dehydrogenase. With the aim of proposing FADS as a novel target for cancer therapy, the inhibitory effect of Chicago Sky Blue on FADS enzymatic activity was tested on the recombinant 6His-hFADS2 (IC50  = 1.2 μm) and PANC-1-derived CSCs' lysate (IC50  = 2-10 μm). This molecule was found effective in inhibiting the growth of PANC-1 and even more of its derived CSC line, thus assessing its role as a potential chemotherapeutic drug.

Prenylated PALM2 Promotes the Migration of Esophageal Squamous Cell Carcinoma Cells Through Activating Ezrin

Proteins containing a CAAX motif at the C-terminus undergo prenylation for localization and activity and include a series of key regulatory proteins, such as RAS superfamily members, heterotrimeric G proteins, nuclear lamina protein, and several protein kinases and phosphatases. However, studies of prenylated proteins in esophageal cancer are limited. Here, through research on large-scale proteomic data of esophageal cancer in our laboratory, we found that paralemmin-2 (PALM2), a potential prenylated protein, was upregulated and associated with poor prognosis in patients. Low-throughput verification showed that the expression of PALM2 in esophageal cancer tissues was higher than that in their paired normal esophageal epithelial tissues, and it was generally expressed in the membrane and cytoplasm of esophageal cancer cells. PALM2 interacted with the two subunits of farnesyl transferase (FTase), FNTA and FNTB. Either the addition of an FTase inhibitor or mutation in the CAAX motif of PALM2 (PALM2C408S) impaired its membranous localization and reduced the membrane location of PALM2, indicating PALM2 was prenylated by FTase. Overexpression of PALM2 enhanced the migration of esophageal squamous cell carcinoma cells, whereas PALM2C408S lost this ability. Mechanistically, PALM2 interacted with the N-terminal FERM domain of ezrin of the ezrin/radixin/moesin (ERM) family. Mutagenesis indicated that lysine residues K253/K254/K262/K263 in ezrin's FERM domain and C408 in PALM2's CAAX motif were important for PALM2/ezrin interaction and ezrin activation. Knockout of ezrin prevented enhanced cancer cell migration by PALM2 overexpression. PALM2, depending on its prenylation, increased both ezrin membrane localization and phosphorylation of ezrin at Y146. In summary, prenylated PALM2 enhances the migration of cancer cells by activating ezrin.

Targeting USP10 induces degradation of oncogenic ANLN in esophageal squamous cell carcinoma

Anillin (ANLN) is a mitosis-related protein that promotes contractile ring formation and cytokinesis, but its cell cycle-dependent degradation mechanisms in cancer cells remain unclear. Here, we show that high expression of ANLN promotes cytokinesis and proliferation in esophageal squamous cell carcinoma (ESCC) cells and is associated with poor prognosis in ESCC patients. Furthermore, the findings of the study showed that the deubiquitinating enzyme USP10 interacts with ANLN and positively regulates ANLN protein levels. USP10 removes the K11- and K63-linked ubiquitin chains of ANLN through its deubiquitinase activity and prevents ANLN ubiquitin-mediated degradation. Importantly, USP10 promotes contractile ring assembly at the cytokinetic furrow as well as cytokinesis by stabilizing ANLN. Interestingly, USP10 and the E3 ubiquitin ligase APC/C co-activator Cdh1 formed a functional complex with ANLN in a non-competitive manner to balance ANLN protein levels. In addition, the macrolide compound FW-04-806 (F806), a natural compound with potential for treating ESCC, inhibited the mitosis of ESCC cells by targeting USP10 and promoting ANLN degradation. F806 selectively targeted USP10 and inhibited its catalytic activity but did not affect the binding of Cdh1 to ANLN and alters the balance of the USP10-Cdh1-ANLN complex. Additionally, USP10 expression was positively correlated with ANLN level and poor prognosis of ESCC patients. Overall, targeting the USP10-ANLN axis can effectively inhibit ESCC cell-cycle progression.

SERPINB2, an Early Responsive Gene to Epigallocatechin Gallate, Inhibits Migration and Promotes Apoptosis in Esophageal Cancer Cells

Esophageal cancer is a lethal disease that frequently occurs in developing countries, the incidence of which could be declined by drinking EGCG-enriched drinks or food. SERPINB2, whose complex functions and regulations are not yet fully understood, are induced by multiple inflammatory molecules and anti-tumor agents. Here, we identify 2444 EGCG-regulated genes in esophageal cancer cells, including SERPINB2. EGCG treatment recruits NF-κB at the promoter and enhancers of SERPINB2 and activates gene transcription, which is repressed by NF-κB knockdown or inhibition. Loss of SERPINB2 leads to a faster migration rate and less expression of Caspase-3 in cancer cells. Our study demonstrates that SERPINB2 is a new tumor-suppressor gene involved in cell movement and apoptosis and could be a therapeutic target for esophageal cancer.

A New Mechanism for Ginsenoside Rb1 to Promote Glucose Uptake, Regulating Riboflavin Metabolism and Redox Homeostasis

Glucose absorption promoters perform insulin mimic functions to enhance blood glucose transport to skeletal muscle cells and accelerate glucose consumption, thereby reducing blood glucose levels. In our screening exploration of food ingredients for improving glucose transportation and metabolism, we found that the saponins in American ginseng (Panaxquinquefolius L.) showed potential activity to promote glucose uptake, which can be used for stabilizing levels of postprandial blood glucose. The aim of this study was to identify key components of American ginseng with glucose uptake-promoting activity and to elucidate their metabolic regulatory mechanisms. Bio-guided isolation using zebrafish larvae and 2-NBDG indicator identified ginsenoside Rb1 (GRb1) as the most potential promotor of glucose uptake. Using UPLC-QTOF-MS/MS combined with RT-qPCR and phenotypic verification, we found that riboflavin metabolism is the hinge for GRb1-mediated facilitation of glucose transport. GRb1-induced restoration of redox homeostasis was mediated by targeting riboflavin transporters (SLC52A1 and SLC52A3) and riboflavin kinase (RFK).

Decoding signal transducer and activator of transcription 1 across various cancers through data mining and integrative analysis

OBJECTIVES

Using different online available databases and Bioinformatics tools, we extensively studied the role STAT1 across different cancers.

METHODS

STAT1 mRNA, protein expression, and promoter methylation were analyzed and validated using UALCAN, GENT2, Human Protein Atlas (HPA), and MEXPRESS. Furthermore, the potential prognostic values were evaluated through KM plotter. Then, cBioPortal was utilized to examine the STAT1-related genetic mutations, while pathway enrichment analysis was performed using DAVID. To identify STAT1 targeted microRNAs (miRNAs) and transcription factors (TFs) we used Enricher. Moreover, a correlational analysis between STAT1 expression tumor purity and CD8+ T immune cells and a gene-drug interaction network analysis was performed using TIMER, CTD, and Cytoscape.

RESULTS

In 23 major human cancers, STAT1 expression was notably up-regulated relative to corresponding controls. As well, the elevated expression of STAT1 was exclusively found to be associated with the reduced overall survival (OS) of Esophageal Carcinoma (ESCA), Kidney Renal Clear Cell Carcinoma (KIRC), and Lung adenocarcinoma (LUAD) patients. This implies that STAT1 plays a significant role in the development and progression of these three cancers. Further pathway analysis indicated that STAT1 enriched genes were involved in six critical pathways, while a few interesting correlations were also documented between STAT1 expression and promoter methylation level, tumor purity, CD8+ T immune cells infiltration, and genetic alteration. In addition, we have also predicted a few miRNAs, TFs, and chemotherapeutic drugs that could regulate the STAT1 expression.

CONCLUSION

The current study revealed the shared oncogenic, diagnostic, and prognostic role of STAT1 in ESCA, KIRC, and LUAD.

TRIP13 Induces Nedaplatin Resistance in Esophageal Squamous Cell Carcinoma by Enhancing Repair of DNA Damage and Inhibiting Apoptosis

Thyroid hormone receptor interactor 13 (TRIP13) plays a crucial role in poor prognosis and chemotherapy resistance of cancer patients. This present study is aimed at investigating the role of high expression of TRIP13 inducing nedaplatin (NDP) resistance in esophageal squamous cell carcinoma (ESCC) cells. High expression of TRIP13 promoted the proliferation and migration of ESCC cells performed by MTS assay, colony formation assay, wound healing assay, and transwell assay. High TRIP13 expression induced NDP resistance to ESCC based on the cell proliferation promoting/inhibition rate and cell migration promoting/inhibition rate analysis, flow cytometry assay of apoptotic subpopulations with a combination of Annexin V-FITC and propidium iodide, and Western blot analysis downregulating cleaved PARP, γH2A.X, cleaved caspase-3, and Bax and upregulating Bcl-2 expression. This study indicated that high expression of TRIP13 promoted proliferation and migration of ESCC cells and induced NDP resistance via enhancing repair of DNA damage and inhibiting apoptosis. This will provide a preliminary reference for the clinical use of NDP in ESCC treatment.

The Effect of Endoscopy on Patients with Malignant Esophageal Cancer after Medical Treatment and Chemotherapy

The esophagus is one of the most commonly used parts in a person’s life, and its importance is self-evident. With the unhealthy food diet, people are more and more likely to suffer from esophageal cancer, and there is an urgent need for breakthroughs in the treatment of esophageal cancer. This article is aimed at studying the effects of medical treatment and chemotherapy for patients with malignant esophageal cancer. To this end, this article proposes a treatment method based on endoscopy and improves the image imaging of the endoscopy and the image quality of the image and the edge processing of the image. At the same time, this article designs an experiment to conduct statistical analysis of the situation during the treatment process. The experimental results in this article show that the improved treatment method has a 21% increase in success rate compared with the existing treatment method. And the optimized image quality has increased by 27%. It can very well help the attending doctor to improve the efficiency of treatment in the actual treatment process. Its most important contribution is that through the edge optimization and image enhancement processing technology, the success rate of endoscopic treatment has been better improved, and the treatment efficiency has also been improved.

Recent advances in riboflavin transporter RFVT and its genetic disease

Riboflavin (vitamin B2) is essential for cellular growth and function. It is enzymatically converted to flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which participate in the metabolic oxidation-reduction reactions of carbohydrates, amino acids, and lipids. Human riboflavin transporters RFVT1, RFVT2, and RFVT3 have been identified and characterized since 2008. They are highly specific transporters of riboflavin. RFVT3 has functional characteristics different from those of RFVT1 and RFVT2. RFVT3 contributes to absorption in the small intestine, reabsorption in the kidney, and transport to the fetus in the placenta, while RFVT2 mediates the tissue distribution of riboflavin from the blood. Several mutations in the SLC52A2 gene encoding RFVT2 and the SLC52A3 gene encoding RFVT3 were found in patients with a rare neurological disorder known as Brown-Vialetto-Van Laere syndrome. These patients commonly present with bulbar palsy, hearing loss, muscle weakness, and respiratory symptoms in infancy or later in childhood. A decrease in plasma riboflavin levels has been observed in several cases. Recent studies on knockout mice and patient-derived cells have advanced the understanding of these mechanisms. Here, we summarize novel findings on RFVT1-3 and their genetic diseases and discuss their potential as therapeutic drugs.

Promotion of rs3746804 (p. L267P) polymorphism to intracellular SLC52A3a trafficking and riboflavin transportation in esophageal cancer cells

Riboflavin is an essential micronutrient for normal cellular growth and function. Lack of dietary riboflavin is associated with an increased risk for esophageal squamous cell carcinoma (ESCC). Previous studies have identified that the human riboflavin transporter SLC52A3a isoform (encoded by SLC52A3) plays a prominent role in esophageal cancer cell riboflavin transportation. Furthermore, SLC52A3 gene single nucleotide polymorphisms rs3746804 (T>C, L267P) and rs3746803 (C >T, T278M) are associated with ESCC risk. However, whether SLC52A3a (p.L267P) and (p.T278M) act in riboflavin transportation in esophageal cancer cell remains inconclusive. Here, we constructed the full-length SLC52A3a protein fused to green fluorescent protein (GFP-SLC52A3a-WT and mutants L267P, T278M, and L267P/T278M). It was confirmed by immunofluorescence-based confocal microscopy that SLC52A3a-WT, L267P, T278M, and L267P/T278M expressed in cell membrane, as well as in a variety of intracellular punctate structures. The live cell confocal imaging showed that SLC52A3a-L267P and L267P/T278M increased the intracellular trafficking of SLC52A3a in ESCC cells. Fluorescence recovery after photobleaching of GFP-tagged SLC52A3a meant that intracellular trafficking of SLC52A3a-L267P and L267P/T278M was rapid dynamics process, leading to its stronger ability to transport riboflavin. Taken together, the above results indicated that the rs3746804 (p.L267P) polymorphism promoted intracellular trafficking of SLC52A3a and riboflavin transportation in ESCC cells.

Alteration of Flavin Cofactor Homeostasis in Human Neuromuscular Pathologies

The aim of this short review chapter is to provide a brief summary of the relevance of riboflavin (Rf or vitamin B2) and its derived cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) for human neuromuscular bioenergetics.Therefore, as a completion of this book we would like to summarize what kind of human pathologies could derive from genetic disturbances of Rf transport, flavin cofactor synthesis and delivery to nascent apoflavoproteins, as well as by alteration of vitamin recycling during protein turnover.

The correlation of the peripheral blood NT-proBNP and NF-κB expression levels with the myocardial infarct area and the post-treatment no-reflow in acute myocardial infarction patients

OBJECTIVE

To explore the correlation of the peripheral blood NT-proBNP and NF-κB p65 expression levels in the peripheral blood with the myocardial infarct areas on the admission and post-treatment no-reflow of acute myocardial infarction patients.

METHODS

A total of 124 acute myocardial infarction patients treated in our hospital were placed in an acute myocardial infarction group, 115 patients with stable coronary heart disease were placed in a coronary heart disease group, and 121 healthy people undergoing routine physical examinations were placed in a healthy examination group. After the treatment, the myocardial infarction patients were divided into grade I, grade II, grade III, and grade IV groups according to their Killip heart function classifications. The patients were divided into reflow (thrombolysis in myocardial infarction (TIMI) > grade 2) and no-reflow (TIMI ≤ grade 2) groups according to their flow grades, and into single branch, double branch, and multi-branch groups according to each patient's number of diseased coronary vessels. The Wagner scale scores were used to estimate the infarct areas. All the patients were divided into small area, medium area, and large area groups according to the score results or into good prognosis and poor prognosis groups according to the presence or absence of complications. The amino-terminal pro-brain natriuretic peptide (NT-proBNP) and the nuclear factor-kappa B p65 (NF-κB p65) expression levels in the peripheral blood among the groups were compared.

RESULTS

The NT-proBNP and NF-κB p65 expression levels in the peripheral blood were significantly lower in the physical examination and coronary heart disease groups than they were in the acute myocardial infarction group (P<0.001) and were the lowest in the physical examination group (P<0.05). The expression levels were the lowest in the grade I group according to their Killip heart function classification (P<0.001) and increased gradually in each of the grade I to IV groups (all P<0.001). The expression levels were lowest in the single branch group and highest in the multi-branch group (P<0.001). The expression levels were lower in the no-reflow group than they were in the reflow group (P<0.001). The expression levels increased in the large area group compared with the small area and medium area groups (P<0.001). The expression levels were higher in the poor prognosis group than in the good prognosis group (P<0.001).

CONCLUSION

Patients with high peripheral blood NT-proBNP and NF-κB expression levels had increased myocardial infarct areas. The peripheral blood NT-proBNP and NF-κB levels increased in the patients with post-treatment reflow. Therefore, the NT-proBNP and NF-κB expression levels can be used as important indicators for predicting the severity and prognoses of acute myocardial infarction patients.

Epigenetic Study of Esophageal Carcinoma Based on Methylation, Gene Integration and Weighted Correlation Network Analysis

Purpose

Esophageal carcinoma is a common and highly metastatic malignant tumor of the digestive tract. The aim of the present study was to identify potential molecular markers of esophageal carcinoma that may help its diagnosis and treatment.

Materials and Methods

First, mRNA and DNA methylation data were downloaded from The Cancer Genome Atlas (TCGA) database for the identification of differentially expressed genes (DEGs) and DNA methylation analysis. Secondly, Weighted Gene Co-Expression Network Analysis (WGCNA) was used to identify important modules and hub genes. In addition, correlation analysis between DNA methylation genes and DEGs was performed. Thirdly, the GSE45670 dataset was used to validate the expression of the diagnostic and survival ability analysis of genes in TCGA data. Finally, reverse transcription-quantitative PCR and immunohistochemical analysis of genes were performed.

Results

A total of 2408 DEGs and 5134 differentially methylated sites were obtained. In the WGCNA analysis, the royal blue module was found to be the optimal module. In addition, hub genes in the module, including ESRRG, MFSD4, CCKBR, ATP4B, ESRRB, ATP4A, CCKAR and B3GAT1, were also differentially methylated genes and DEGs. It was found that CCKAR, MFSD4 and ESRRG may be diagnostic gene biomarkers for esophageal carcinoma. In addition, the high expression of MFSD4 was significantly correlated with patient survival. Immunohistochemistry analysis results showed that the gene expression levels of ATP4B, B3GAT1, CCKBR and ESRRG were decreased in esophageal carcinoma tissues, which was in line with the bioinformatics results.

Conclusion

Therefore, these identified molecular markers may be helpful in the diagnosis and treatment of esophageal carcinoma.

Dietary riboflavin deficiency induces ariboflavinosis and esophageal epithelial atrophy in association with modification of gut microbiota in rats

PURPOSE

Riboflavin deficiency causes ariboflavinosis, a common nutritional deficiency disease. The purpose of this study is to investigate the effects of riboflavin deficiency on the important internal organs and its potential mechanisms.

METHODS

Experiment 1, male F344 rats were randomly assigned to R₆ (normal riboflavin, 6 mg/kg) and R₀ (riboflavin-deficient, 0 mg/kg) groups. Experiment 2 rats were assigned to R₆, R_0.6 (0.6 mg/kg) and R_0.06 (0.06 mg/kg) groups. Experiment 3 rats were assigned to R₆ and R₀ → R₆ (riboflavin replenishment) groups. Bacterial communities were analyzed based on 16S rRNA gene sequencing.

RESULTS

Riboflavin deficiency induced ariboflavinosis (R_0.06 46.7%; R₀ 72%) and esophageal epithelial atrophy (R_0.06 40%; R₀ 44%) in rats, while the R₆ group did not display symptoms (P < 0.001, respectively). Esophageal epithelial atrophy occurred simultaneously (R_0.06 66.7%; R₀ 63.6%) with ariboflavinosis or appeared alone (R_0.06 33.3%; R₀ 36.4%). Esophagus is the most vulnerable internal organ. Riboflavin deficiency followed by replenishment (R₀ → R₆) was effective in treating ariboflavinosis (83.3% vs. 0%, P < 0.001) and esophageal epithelial atrophy (66.7% vs. 20%, P = 0.17). Riboflavin deficiency modulated gut microbiota composition. The several key genera (Romboutsia, Turicibacter and Clostridium sensu stricto 1) were strongly correlated with ariboflavinosis and esophageal epithelial atrophy (P < 0.01 or P < 0.05). The potential mechanism is that gut microbiota affects body's xenobiotic biodegradation and metabolism, and genomic instability.

CONCLUSIONS

Riboflavin deficiency induces ariboflavinosis and esophageal epithelial atrophy by modulating the gut microbiota, and offers new Queryinsight into riboflavin deficiency and esophageal lesions.

Lactobacillus plantarum KSFY06 Prevents Inflammatory Response and Oxidative Stress in Acute Liver Injury Induced by D-Gal/LPS in Mice

AIM

The purpose of this study is to investigate the preventive effect of Lactobacillus plantarum KSFY06 (LP-KSFY06) on D-galactose/lipopolysaccharide (D-Gal/LPS)-induced acute liver injury (ALI) in mice.

METHODS

We evaluated the antioxidant capacity of LP-KSFY06 in vitro, detailed the effects of LP-KSFY06 on the organ index, liver function index, biochemical index, cytokines, and related genes, and noted the accompanying pathological changes.

RESULTS

The results clearly showed that LP-KSFY06 can remove 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline -6-sulphonic acid) diammonium salt (ABTS) free radicals in vitro. The analysis of the organ index and pathology demonstrated that LP-KSFY06 significantly prevented ALI. Biochemical and molecular biological analysis showed that LP-KSFY06 prevented a decrease in the antioxidant-related levels of superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC), and also prevented an increase in aspartate aminotransaminase (AST), alanine aminotransaminase (ALT), malondialdehyde (MDA), myeloperoxidase (MPO), and nitric oxide (NO) levels. LP-KSFY06 upregulated the anti-inflammatory factor interleukin (IL)-10 and downregulated the pro-inflammatory factors IL-6, IL-1β, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). These oxidative and inflammatory indicators were consistent with the results of gene detections. Furthermore, we determined that LP-KSFY06 downregulated Keap1, NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB), IL-18, and mitogen-activated protein kinase 14 (MAPK14 or p38), upregulated Nrf2, heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase [quinone] 1 (NQO1), B-cell inhibitor-α (IκB-α), and thioredoxin (Trx) mRNA expression. These may be related to the regulation of the Kelch-like ECH-associated protein-1 (Keap1)-nuclear factor-erythroid-2-related factor (Nrf2)/antioxidant response element (ARE) and NLRP3/NF-κB pathways.

CONCLUSION

LP-KSFY06 is an effective multifunctional Lactobacillus with strong anti-oxidant and anti-inflammatory ability that can prevent D-gal/LPS-induced ALI in mice and assist in maintaining health.

Influence of Riboflavin Targeting on Tumor Accumulation and Internalization of Peptostar Based Drug Delivery Systems

Riboflavin carrier protein (RCP) and riboflavin transporters (RFVTs) have been reported to be highly overexpressed in various cancer cells. Hence, targeting RCP and RFVTs using riboflavin may enhance tumor accumulation and internalization of drug delivery systems. To test this hypothesis, butyl-based 3-arm peptostar polymers were synthesized consisting of a lysine core (10 units per arm) and a sarcosine shell (100 units per arm). The end groups of the arms and the core were successfully modified with riboflavin and the Cy5.5 fluorescent dye, respectively. While in phosphate buffered saline the functionalized peptostars showed a bimodal behavior and formed supramolecular structures over time, they were stable in the serum maintaining their hydrodynamic diameter of 12 nm. Moreover, the polymers were biocompatible and the uptake of riboflavin targeted peptostars in A431 and PC3 cells was higher than in nontargeted controls and could be blocked competitively. In vivo, the polymers showed a moderate passive tumor accumulation, which was not significantly different between targeted and nontargeted peptostars. Nonetheless, at the histological level, internalization into tumor cells was strongly enhanced for the riboflavin-targeted peptostars. Based on these results, we conclude that passive accumulation is dominating the accumulation of peptostars, while tumor cell internalization is strongly promoted by riboflavin targeting.

Dietary riboflavin deficiency induces genomic instability of esophageal squamous cells that is associated with gut microbiota dysbiosis in rats

SCOPE

Epidemiologic evidence suggests that riboflavin (RBF) deficiency is a specific nutritional predisposition for esophageal cancer. The aim of this study is to investigate the potential roles of gut microbiota in esophageal tumorigenesis caused by the RBF deficiency.

METHODS

Male F344 rats were subcutaneously injected with the chemical carcinogen N-nitrosomethylbenzylamine (NMBA, 0.35 mg kg-1). Rats were assigned to 4 groups, denoted as R6 (normal RBF, 6 mg kg-1), R6N (normal RBF combined with NMBA), R6N → R0N (normal RBF conversion to RBF-deficiency), and R0N → R6N (RBF-deficiency conversion to normal RBF). Bacterial communities were analyzed based on high-throughput 16S rRNA gene sequencing. Oxidative DNA damage and double-strand break markers were studied by immunohistochemistry.

RESULTS

The R6N → R0N diet enhanced the incidence of esophageal intraepithelial neoplasia (EIN, 40 weeks 66.7% vs. 25 weeks 16.7%, P < 0.05). RBF deficiency and replenishment modulated the gut microbiota composition. The gut microbiota (e.g. Caulobacteraceae, Sphingomonas and Bradyrhizobium) affected xenobiotic biodegradation and the genomic instability of the host. Furthermore, the RBF deficiency aggravated oxidative DNA damage and DNA double-strand breaks (immunohistochemistry) in the esophageal epithelium, whereas the RBF replenishment had the opposite effect (P < 0.05, respectively).

CONCLUSIONS

RBF deficiency promotes NMBA-induced esophageal tumorigenesis, which is associated with gut microbiota-associated genomic instability, and offers new insights into the role of RBF deficiency in esophageal carcinogenesis.

Functional variation of SLC52A3 rs13042395 predicts survival of Chinese gastric cancer patients

The solute carrier family 52 member 3 (SLC52A3) gene encodes riboflavin transporter protein which is essential to maintain mitochondrial function in cells. In our research, we found that SLC52A3 rs13042395 C > T variation was significantly associated with poor survival in a 926 Chinese gastric cancer (GCa) patients cohort (CC/CT genotype versus TT genotype, HR = 0.57, 95%CI (0.40-0.82), log-rank P = 0.015). The SLC52A3 rs13042395 C > T change led to its increased mRNA expression according to expression quantitative trait loci analysis (P = 0.0029). In vitro, it was revealed that rs13042395 C allele had higher binding affinity to inhibitory transcription factor Meis homeobox 1 (MEIS1) compared with T allele, knock-down of MEIS1 could up-regulate SLC52A3, and overexpression of SLC52A3 contributed to the increased ability of proliferation, colony formation, migration and invasion in GCa cells. Subsequently, the bioinformatics analysis combined with experiments in vitro suggested that Gap junction protein alpha 1 (GJA1) was the downstream effector of SLC52A3, SLC52A3 may promote the GCa cells aggressiveness by down-regulating the GJA1 expression. Overall, SLC52A3 genetic variant rs13042395 C > T change was associated with poorer survival in Chinese GCa patients and increased SLC52A3 expression by interaction with MEIS1. SLC52A3 promoted the GCa cells aggressiveness by down-regulating the GJA1 expression.

Characterization of super-enhancer-associated functional lncRNAs acting as ceRNAs in ESCC

Long noncoding RNAs (lncRNAs) have important regulatory roles in cancer biology. Although some lncRNAs have well-characterized functions, the vast majority of this class of molecules remains functionally uncharacterized. To systematically pinpoint functional lncRNAs, a computational approach was proposed for identification of lncRNA-mediated competing endogenous RNAs (ceRNAs) through combining global and local regulatory direction consistency of expression. Using esophageal squamous cell carcinoma (ESCC) as model, we further identified many known and novel functional lncRNAs acting as ceRNAs (ce-lncRNAs). We found that most of them significantly regulated the expression of cancer-related hallmark genes. These ce-lncRNAs were significantly regulated by enhancers, especially super-enhancers (SEs). Landscape analyses for lncRNAs further identified SE-associated functional ce-lncRNAs in ESCC, such as HOTAIR, XIST, SNHG5, and LINC00094. THZ1, a specific CDK7 inhibitor, can result in global transcriptional downregulation of SE-associated ce-lncRNAs. We further demonstrate that a SE-associated ce-lncRNA, LINC00094 can be activated by transcription factors TCF3 and KLF5 through binding to SE regions and promoted ESCC cancer cell growth. THZ1 downregulated expression of LINC00094 through inhibiting TCF3 and KLF5. Our data demonstrated the important roles of SE-associated ce-lncRNAs in ESCC oncogenesis and might serve as targets for ESCC diagnosis and therapy.

Development of Novel Experimental Models to Study Flavoproteome Alterations in Human Neuromuscular Diseases: The Effect of Rf Therapy

Inborn errors of Riboflavin (Rf) transport and metabolism have been recently related to severe human neuromuscular disorders, as resulting in profound alteration of human flavoproteome and, therefore, of cellular bioenergetics. This explains why the interest in studying the “flavin world”, a topic which has not been intensively investigated before, has increased much over the last few years. This also prompts basic questions concerning how Rf transporters and FAD (flavin adenine dinucleotide) -forming enzymes work in humans, and how they can create a coordinated network ensuring the maintenance of intracellular flavoproteome. The concept of a coordinated cellular “flavin network”, introduced long ago studying humans suffering for Multiple Acyl-CoA Dehydrogenase Deficiency (MADD), has been, later on, addressed in model organisms and more recently in cell models. In the frame of the underlying relevance of a correct supply of Rf in humans and of a better understanding of the molecular rationale of Rf therapy in patients, this review wants to deal with theories and existing experimental models in the aim to potentiate possible therapeutic interventions in Rf-related neuromuscular diseases.

Prognostic Value and Immune Infiltrates of ABCA8 and FABP4 in Stomach Adenocarcinoma

Background

Stomach adenocarcinoma (STAD) is a common malignancy worldwide with poor prognosis. Therefore, it is important to identify a valuable prognostic biomarker for STAD. The aim of present study was to identify novel prognostic biomarkers for STAD and evaluate the potential role of hub genes in STAD.

Methods

Gene Expression Profiling Interactive Analysis (GEPIA) and Cancer RNA-Seq Nexus were performed to identify differentially expressed genes (DEGs). Subsequently, hub genes were selected by a Venn diagram, and the expression of key genes was confirmed by UALCAN database. Furthermore, survival analysis of these hub genes was performed using Oncolnc and Human Protein Atlas (HPA) database. Gene alteration status of hub genes was assessed by cBioPortal. Finally, we investigated the association between hub genes and immune cell infiltration in STAD through the Tumor Immune Estimation Resource (TIMER) and GEPIA database.

Results

Three common hub genes were obtained, including 2 downregulated DEGs (ABCA8 and FABP4) and one upregulated DEG (SLC52A3). Furthermore, increased expression of ABCA8 and FABP4 and decreased expression of SLC52A3 were correlated with poor prognosis. Meanwhile, three hub genes showed genetic alterations in various datasets of STAD. Finally, our results showed that ABCA8 and FABP4 displayed a positive correlation with immune infiltration, especially in M2 macrophages.

Conclusions

The results of this study suggest that ABCA8 and FABP4 may be used as prognostic biomarkers and correlated with immune infiltration in STAD.

Transcription/Expression of KLRB1 Gene as A Prognostic Indicator in Human Esophageal Squamous Cell Carcinoma

AIM AND OBJECTIVE

Esophageal squamous cell carcinoma (ESCC) is the most prevalent type of cancer with worldwide distribution and dismal prognosis despite ongoing efforts to improve treatment options. Therefore, it is essential to determine the prognostic factors for ESCC.

METHODS AND RESULTS

We determined KLRB1 to be a prognostic indicator of human ESCC. KLRB1 was expressed at low levels in ESCC patients. Based on the risk score, patients were divided into high and low-risk groups. High-risk patients showed a poor survival rate. The prediction model based on the N stage, sex, and KLRB1 was significantly better than that based on the N stage and sex. The modified prediction model showed a robust ROC curve with an AUC value of 0.973. The knockdown of KLRB1 inhibited the growth of human ESCC cells. KLRB1 regulated Akt, mTOR, p27, p38, NF-κB, Cyclin D1, and JNK signaling, which was consistent with the result of GSEA.

CONCLUSION

KLRB1 is a potential prognostic marker for human ESCC patients.

HIPK3 Promotes Growth and Metastasis of Esophageal Squamous Cell Carcinoma via Regulation of miR-599/c-MYC Axis

Background/Aims

this experimental design was based on HIPK3 to explore the pathogenesis of ESCC.

Methods

RT-qPCR was used to detect the expression of CircHIPK3 and miR-599 in ESCC tissues and cell lines.CCK-8, colony formation, flow cytometry and transwell assay were used to detect the effects of CircHIPK3 and miR-599 on tumor cell proliferation, apoptosis and migration and invasion. Target gene prediction and screening, luciferase reporter assays were used to validate downstream target genes of CircHIPK3 and miR-599.mRNA and protein expression of c-MYC were detected by RT-qPCR and Western blotting. The tumor changes in mice were detected by in vivo experiments in nude mice.

Results

HIPK3 was highly expressed in ESCC tissues and cell lines. In addition, HIPK3 expression levels were associated with advanced TNM stage, lymph node metastasis and tumor size. Moreover, HIPK3 was significantly promoted cell proliferation and migration of ESCC cells. In addition, HIPK3 was able to inhibit miRNA-599 expression and up-regulate the expression level of c-MYC. Finally, the results of in vivo animal models confirmed that HIPK3 promoted ESCC progression by modulating the miR-599/c-MYC axis.

Conclusion

HIPK3 can regulate the proliferation of esophageal squamous cell carcinoma cells by regulating miR-599/c-MYC axis, thereby inhibiting the occurrence and development of esophageal squamous cell carcinoma.

Riboflavin-Targeted Drug Delivery

Active targeting can improve the retention of drugs and drug delivery systems in tumors, thereby enhancing their therapeutic efficacy. In this context, vitamin receptors that are overexpressed in many cancers are promising targets. In the last decade, attention and research were mainly centered on vitamin B9 (folate) targeting; however, the focus is slowly shifting towards vitamin B2 (riboflavin). Interestingly, while the riboflavin carrier protein was discovered in the 1960s, the three riboflavin transporters (RFVT 1-3) were only identified recently. It has been shown that riboflavin transporters and the riboflavin carrier protein are overexpressed in many tumor types, tumor stem cells, and the tumor neovasculature. Furthermore, a clinical study has demonstrated that tumor cells exhibit increased riboflavin metabolism as compared to normal cells. Moreover, riboflavin and its derivatives have been conjugated to ultrasmall iron oxide nanoparticles, polyethylene glycol polymers, dendrimers, and liposomes. These conjugates have shown a high affinity towards tumors in preclinical studies. This review article summarizes knowledge on RFVT expression in healthy and pathological tissues, discusses riboflavin internalization pathways, and provides an overview of RF-targeted diagnostics and therapeutics.

Identification of key genes by integrating DNA methylation and next-generation transcriptome sequencing for esophageal squamous cell carcinoma

Aberrant DNA methylation leads to abnormal gene expression, making it a significant regulator in the progression of cancer and leading to the requirement for integration of gene expression with DNA methylation. Here, we identified 120 genes demonstrating an inverse correlation between DNA methylation and mRNA expression in esophageal squamous cell carcinoma (ESCC). Sixteen key genes, such as SIX4, CRABP2, and EHD3, were obtained by filtering 10 datasets and verified in paired ESCC samples by qRT-PCR. 5-Aza-dC as a DNA methyltransferase (DNMT) inhibitor could recover their expression and inhibit clonal growth of cancer cells in seven ESCC cell lines. Furthermore, 11 of the 16 genes were correlated with OS (overall survival) and DFS (disease-free survival) in 125 ESCC patients. ChIP-Seq data and WGBS data showed that DNA methylation and H3K27ac histone modification of these key genes displayed inverse trends, suggesting that there was collaboration between DNA methylation and histone modification in ESCC. Our findings illustrate that the integrated multi-omics data (transcriptome and epigenomics) can accurately obtain potential prognostic biomarkers, which may provide important insight for the effective treatment of cancers.

The exploration of disease-specific gene regulatory networks in esophageal carcinoma and stomach adenocarcinoma

BACKGROUND

Feed-forward loops (FFLs), consisting of miRNAs, transcription factors (TFs) and their common target genes, have been validated to be important for the initialization and development of complex diseases, including cancer. Esophageal Carcinoma (ESCA) and Stomach Adenocarcinoma (STAD) are two types of malignant tumors in the digestive tract. Understanding common and distinct molecular mechanisms of ESCA and STAD is extremely crucial.

RESULTS

In this paper, we presented a computational framework to explore common and distinct FFLs, and molecular biomarkers for ESCA and STAD. We identified FFLs by combining regulation pairs and RNA-seq data. Then we constructed disease-specific co-expression networks based on the FFLs identified. We also used random walk with restart (RWR) on disease-specific co-expression networks to prioritize candidate molecules. We identified 148 and 242 FFLs for these two types of cancer, respectively. And we found that one TF, E2F3 was related to ESCA, two genes, DTNA and KCNMA1 were related to STAD, while one TF ESR1 and one gene KIT were associated with both of the two types of cancer.

CONCLUSIONS

This proposed computational framework predicted disease-related biomolecules effectively and discovered the correlation between two types of cancers, which helped develop the diagnostic and therapeutic strategies of Esophageal Carcinoma and Stomach Adenocarcinoma.

Silencing of RBP‑JK promotes the differentiation of bone marrow mesenchymal stem cells into vascular endothelial cells

Bone marrow mesenchymal stem cells (BM-MSCs) are important for postnatal angiogenesis and are suitable for use in construction of blood vessels by tissue engineering. The present study aimed to investigate the influence of recombination signal binding protein for immunoglobulin kappa J region (RBP-JK) on the differentiation of BM-MSCs into vascular endothelial cells, and to assess the underlying mechanisms. BM-MSCs were isolated and identified by flow cytometry. Lentiviral vectors encoding RBP-JK shRNA (shRBPJK) were constructed to knockdown RBP-JK expression and endothelial differentiation of BM-MSCs was induced. The experimental groups were treated with: empty lentiviral vector (vector group), growth factors (bFGF and VEGF; induced group), shRBPJK (shRBPJK group), and growth factors + shRBPJK (induced + shRBPJK group). The expression of endothelial markers, vascular endothelial growth factor receptor 2 (Flk-1), and von Willebrand factor (vWF) were detected by immunofluorescence. Additionally, in vitro blood vessel formation and phagocytosis were assessed using acetylated LDL, Dil complex and the underlying molecular mechanisms evaluated by western blotting. BM-MSCs were separated and transduced with shRBPJK to reduce RBP-JK expression. Compared with the vector group, the expression of the endothelial cell markers, Flk-1 and vWF, in vitro tubule formation, and phagocytosis ability increased, while the expression levels of p-AKT/AKT and p-NF-κB/NF-κB were significantly decreased (P<0.05) in the induced, shRBPJK, and induced + shRBPJK groups. Compared with the induced group, the expression of Flk-1 and vWF, the number of tubules, and phagocytosis were higher in the induced + shRBPJK group, while the expression levels of p-AKT/AKT and p-NF-κB/NF-κB were lower (P<0.05). Collectively, the present data indicated that silencing of RBP-JK promotes the differentiation of MSCs into vascular endothelial cells, and this process is likely regulated by AKT/NF-κB signaling.

The differences of gonadal hormones and uterine transcriptome during shell calcification of hens laying hard or weak-shelled eggs

Background

Eggshell breaking strength is critical to reduce egg breaking rate and avoid economic loss. The process of eggshell calcification initiates with the egg entering the uterus and lasts about 18 h. It follows a temporal sequence corresponding to the initiation, growth and termination periods of shell calcification. During each period of shell calcification, our study investigated the differences of gonadal hormones and uterine transcriptome in laying hens producing a high or low breaking strength shell.

Results

60 Hy-line Brown laying hens were selected and divided into two groups according to eggshell breaking strength. Eggshell breaking strength of 44.57 ± 0.91 N and 26.68 ± 0.38 N were considered to be the high strength group (HS) and low strength group (LS), respectively. The results showed that mammillary thickness and mammillary knob width of eggshells were significantly lower in the HS. Serum progesterone (P₄) and 1,25-dihydroxy vitamin D₃ [1,25-(OH)₂D₃] were significantly higher in the HS compared to the LS during the initiation period of calcification. Serum estradiol (E₂) and calcium did not change significantly. All factors mentioned above had no significant differences in the growth and termination periods of calcification. The relative expression of CaBP-D_28k and PMCA 1b were not significantly different between HS and LS. The relative expression of NCX1 was significantly higher in HS compared to LS. Moreover, 1777 differentially expressed genes (DEGs) were obtained in the initiation period of calcification. However, few DEGs were identified in the growth or termination periods of calcification. 30 DEGs were selected as candidate genes involved in eggshell calcification during the initiation period of calcification by the analysis of GO terms and KEGG pathways.

Conclusions

Our study concluded that mammillary thickness and mammillary knob width of the HS were significantly lower than LS. P₄ and 1,25-(OH)₂D₃ were significantly higher in the initiation period of HS. They may impact initial calcification when the mammillary layer is formed. The initiation period of calcification determined eggshell strength rather than the growth or termination periods. We inferred P₄ or 1,25-(OH)₂D₃ may effect the ultrastructure of the mammillary layer by regulating the expression of uterine genes.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-6017-2) contains supplementary material, which is available to authorized users.

Ribophorin II promotes cell proliferation, migration, and invasion in esophageal cancer cells in vitro and in vivo

Esophageal cancer is a common digestive tract cancer, which is a serious threat to human health. Ribophorin II (RPN2) is a part of an N-oligosaccharyltransferase complex, which is excessively expressed in many kinds of cancers. In the present study, we explore the biological role of RNP2 in esophageal cancer. First, we found that the expression of RPN2 was higher in esophageal cancer tissues than in adjacent non-tumor tissues, and negatively correlated with E-cadherin expression. RPN2 expression levels in esophageal cancer tissues were positively associated with differentiation and tumor node metastasis (TNM) stage. Furthermore, the expression of RPN2 was increased significantly in esophageal cancer cell lines compared with normal cells. The effect of RPN2 down-regulation on cell proliferation, cell migration, and cell invasion was examined by cell counting kit-8 (CCK8), wound healing assay, and Transwell assay, respectively. Silencing RPN2 effectively inhibited cell proliferation of esophageal cancer cells in vitro and in vivo Cell migration and invasion were also weakened dramatically by siRPN2 treatment of esophageal cancer cells. In addition, protein expression of proliferating cell nuclear antigen (PCNA), matrix metalloproteinase (MMP-2), and E-cadherin in esophageal cancer cells was determined by Western blot analysis. PCNA, MMP-2, E-cadherin, Snail and phosphorylation-Smad2/3 expression was also regulated notably by siRPN2 treatment. These findings indicate that RPN2 exhibits oncogenetic capabilities in esophageal cancer, which could provide novel insights into esophageal cancer prevention and treatment.

Evaluation of Riboflavin Transporters as Targets for Drug Delivery and Theranostics

The retention and cellular internalization of drug delivery systems and theranostics for cancer therapy can be improved by targeting molecules. Since an increased uptake of riboflavin was reported for various cancers, riboflavin and its derivatives may be promising binding moieties to trigger internalization via the riboflavin transporters (RFVT) 1, 2, and 3. Riboflavin is a vitamin with pivotal role in energy metabolism and indispensable for cellular growth. In previous preclinical studies on mice, we showed the target-specific accumulation of riboflavin-functionalized nanocarriers in cancer cells. Although the uptake mechanism of riboflavin has been studied for over a decade, little is known about the riboflavin transporters and their expression on cancer cells, tumor stroma, and healthy tissues. Furthermore, evidence is lacking concerning the representativeness of the preclinical findings to the situation in humans. In this study, we investigated the expression pattern of riboflavin transporters in human squamous cell carcinoma (SCC), melanoma and luminal A breast cancer samples, as well as in healthy skin, breast, aorta, and kidney tissues. Low constitutive expression levels of RFVT1-3 were found on all healthy tissues, while RFVT2 and 3 were significantly overexpressed in melanoma, RFVT1 and 3 in luminal A breast cancer and RFVT1-3 in SCC. Correspondingly, the SCC cell line A431 was highly positive for all RFVTs, thus qualifying as suitable in vitro model. In contrast, activated endothelial cells (HUVEC) only presented with a strong expression of RFVT2, and HK2 kidney cells only with a low constitutive expression of RFVT1-3. Functional in vitro studies on A431 and HK2 cells using confocal microscopy showed that riboflavin uptake is mostly ATP dependent and primarily driven by endocytosis. Furthermore, riboflavin is partially trafficked to the mitochondria. Riboflavin uptake and trafficking was significantly higher in A431 than in healthy kidney cells. Thus, this manuscript supports the hypothesis that addressing the riboflavin internalization pathway may be highly valuable for tumor targeted drug delivery.

Dietary riboflavin deficiency promotes N-nitrosomethylbenzylamine-induced esophageal tumorigenesis in rats by inducing chronic inflammation

Epidemiological studies in high-incidence areas of esophageal cancer in China suggest that environmental carcinogen N-nitrosomethylbenzylamine (NMBA) and riboflavin (RBF) deficiency may be the main risk factors for esophageal cancer. However, it is not clear that the combination induces cancer. Here, experiment (Exp) 1 evaluated the effects of NMBA and RBF deficiency individually or in combination on esophageal tumorigenesis. Male F344 rats were randomly assigned to 4 groups into a 2 (no NMBA vs. NMBA) × 2 (normal RBF vs. RBF-deficient) factorial design, including normal RBF (6 mg/kg, R₆), RBF-deficient (0 mg/kg, R₀), normal RBF combined with NMBA (R₆N), and RBF-deficient combined with NMBA (R₀N) groups. The Exp 2 explored the effects of RBF deficiency at different doses combined with NMBA (0.6 mg/kg, R_0.6N; 0.06 mg/kg, R_0.06N) on esophageal tumorigenesis. Results showed that R₀N enhanced the incidence of esophageal intraepithelial neoplasia (EIN, 53.3%, P = 0.06), including carcinoma in situ, whereas R₆N mainly induced the occurrence of esophageal benign hyperplasia (38.9%) and EIN (16.7%). RBF deficiency promotes EIN in a dose-dependent manner, and R_0.06N significantly increases the incidence of EIN (57.9%, P < 0.05). Gene expression profiling demonstrated that inflammatory cytokines were highly expressed in R₀N EIN tissues, whereas R₆N EIN tissues had a proliferation and differentiation gene signature (fold-change > 1.5). Furthermore, RBF deficiency aggravated oxidative DNA damage (8-OHdG) and double-strand breaks (γH2AX) (P < 0.05). Our results suggest that RBF deficiency causes chronic inflammation-associated genomic instability contributes to NMBA-induced esophageal tumorigenesis.

A Novel Clinical Six-Flavoprotein-Gene Signature Predicts Prognosis in Esophageal Squamous Cell Carcinoma

Flavoproteins and their interacting proteins play important roles in mitochondrial electron transport, fatty acid degradation, and redox regulation. However, their clinical significance and function in esophageal squamous cell carcinoma (ESCC) are little known. Here, using survival analysis and machine learning, we mined 179 patient expression profiles with ESCC in GSE53625 from the Gene Expression Omnibus (GEO) database and constructed a signature consisting of two flavoprotein genes (GPD2 and PYROXD2) and four flavoprotein interacting protein genes (CTTN, GGH, SRC, and SYNJ2BP). Kaplan-Meier analysis revealed the signature was significantly associated with the survival of ESCC patients (mean survival time: 26.77 months in the high-risk group vs. 54.97 months in the low-risk group, P < 0.001, n = 179), and time-dependent ROC analysis demonstrated that the six-gene signature had good predictive ability for six-year survival for ESCC (AUC = 0.86, 95% CI: 0.81-0.90). We then validated its prediction performance in an independent set by RT-PCR (mean survival: 15.73 months in the high-risk group vs. 21.1 months in the low-risk group, P=0.032, n = 121). Furthermore, RNAi-mediated knockdown of genes in the flavoprotein signature led to decreased proliferation and migration of ESCC cells. Taken together, CTTN, GGH, GPD2, PYROXD2, SRC, and SYNJ2BP have an important clinical significance for prognosis of ESCC patients, suggesting they are efficient prognostic markers and potential targets for ESCC therapy.

PLCE1 Promotes the Invasion and Migration of Esophageal Cancer Cells by Up-Regulating the PKCα/NF-κB Pathway

PURPOSE

To investigate the effect and mechanism of phospholipase C epsilon gene 1 (PLCE1) expression on esophageal cancer cell lines.

MATERIALS AND METHODS

The esophageal carcinoma cell lines Eca109 and EC9706 and normal esophageal epithelial cell line HEEC were cultured. The expression of PLCE1, protein kinase C alpha (PKCα), and nuclear factor kappa B (NF-κB) p50/p65 homodimer in cells were comparatively analyzed. The esophageal cancer cells were divided into si-PLCE1, control siRNA (scramble), and mock groups that were transfected with specific siRNA for PLCE1, control siRNA, and blank controls, respectively. Expression of PLCE1, PKCα, p50, and p65 was detected by Western blotting. Transwell assay was used to detect migration and invasion of Eca109 and EC9706 cells.

RESULTS

Compared with HEEC, the expression of PLCE1, PKCα, p50, and p65 was increased in Eca109 and EC9706 cells. The expression of PLCE1 was positively correlated with the expression of PKCα and p50 (PKCα: r=0.6328, p=0.032; p50: r=0.6754, p=0.041). PKCα expression had a positive correlation with the expression of p50 and p65 (p50: r=0.9127, p=0.000; p65: r=0.9256, p=0.000). Down-regulation of PLCE1 significantly decreased the expression of PKCα and NF-κB-related proteins (p65: p=0.002, p=0.004; p50: p=0.005, p=0.009) and inhibited the migration and invasion of Eca109 and EC9706 cells.

CONCLUSION

PLCE1 activated NF-κB signaling by up-regulating PKCα, which could promote invasion and migration of esophageal cancer cells.