Down-regulation of ephrin-A5, a gene product of normal cartilage, in chondrosarcoma

The potential mechanisms by which Xiaoyao Powder may exert therapeutic effects on thyroid cancer were examined at various levels

BACKGROUND

Thyroid cancer (TC) is the most prevalent endocrine malignancy, with a rising incidence necessitating safer treatment strategies to reduce overtreatment and its side effects. Xiaoyao Powder (XYP), a widely used herbal formula, shows promise in treating TC. This study aims to investigate the mechanisms by which XYP may affect TC.

METHODS

The components of XYP were identified through database retrieval, and targets related to TC were collected to construct a target network for key screening. GEO dataset samples analyzed immune cells and identified significantly differentially expressed core genes (SDECGs). Based on SDECG expression and clustering, samples were classified for comparison. WGCNA was employed to identify gene modules linked to clinical characteristics. ML models screened characteristic genes and constructed a nomogram validated using another GEO dataset. MR methods explored causal relationships between genes and TC.

RESULTS

The top ten active components of XYP were identified, along with 27 SDECGs that exhibited significant differences in immune cell infiltration between TC patients and normal controls. The nomogram effectively predicted TC risk, validated through ROC curves. Key characteristic genes included SMIM1, PPP1R16A, KIAA1462, DNAJC22, and EFNA5.

CONCLUSION

XYP may treat TC by regulating SMIM1, PPP1R16A, KIAA1462, DNAJC22, EFNA5, and associated immune pathways; this provides theoretical support for its potential mechanisms.

EFNA5 suppresses cell proliferation and tumor metastasis in hepatoma via epithelial-to-mesenchymal transition

BACKGROUND

EphrinA5 belongs to a subclass of ephrin ligands. Abnormal signal transduction of EFNA5 shows a relationship to the development of various tumors. In this study, we explored the level of EFNA5 in hepatoma cells and the influence of up regulation of EFNA5 expression level on the proliferation, invasion, and migration of HepG2 and LM3 cells. Additionally, this work focused on examining its possible mechanism of action, and future impacts on clinical practice.

METHODS

Immunohistochemistry was utilized to explore the connection between EFNA5 and hepatoma. Real-time quantitative polymerase chain reaction was used for determining the expression levels of EFNA5 in several hepatoma cell lines and normal hepatocytes. Cells were transfected with a pCMV3-EFNA5-flag plasmid and an EFNA5 plasmid. The expression efficiency of EFNA5 was identified through qRT-PCR. For the purpose of further identifying cell proliferation, the Cell Counting Kit-8 assay was applied. To identify changes of cell migration and invasion ability, Transwell and Boyden tests were utilized. Western blot was employed to identify the expressions mof EFNA5 and possible downstream molecules.

RESULTS

Data acquired from The Cancer Genome Atlas demonstrated that the level of EFNA5 in hepatoma was significantly downregulated in relative to the normal hepatocytes (P < 0.05). Upregulation of EFNA5 expression in hepatoma cells hindered the proliferative, invasive, and migratory ability of cells (P < 0.05). Additionally, EFNA5 downregulated the level of epithelial-mesenchymal transition-related molecules and EGFR.

CONCLUSIONS

The expression of EFNA5 was low in hepatoma cells. An increase in EFNA5 levels hinders the proliferation, invasion, and migration of hepatoma cells. These effects may occur through inhibition of hepatoma epithelial-mesenchymal transition by EFNA5. Moreover, the study on the mechanisms of proliferation, invasion and metastasis of hepatoma provides a novel theoretical basis, and may influence the clinical practice of tumor treatment in the future.

The Eph/Ephrin system in primary bone tumor and bone cancer pain

The family of Eph receptor tyrosine kinases and their Ephrin ligands system constitutes a bidirectional signaling pathway. Eph/Ephrin system coordinate a wide spectrum of pathologic processes during development, metastasis, prognosis, drug resistance and angiogenesis in carcinogenesis. Chemotherapy, surgery and radiotherapy are the most commonly used clinical treatments for primary bone tumors. Therefore, surgical resection is often unable to completely eliminate the tumor, and this is the main cause of metastasis and postoperative recurrence. A growing body of literature has been published lately revitalizing our scientific interest towards the role of Eph/Ephrins in pathogenesis and the treatment of bone tumor and bone cancer pain. This study mainly reviewed the roles of Eph/Ephrin system that has both tumor-suppressing and -promoting roles in primary bone tumors and bone cancer pain. Understanding the intracellular mechanisms of Eph/Ephrin system in tumorigenesis and metastasis of bone tumors might provide a foundation for the development of Eph/Ephrin targeted anti-cancer therapy.

Inbreeding depression and the probability of racing in the Thoroughbred horse

Small effective population sizes and active inbreeding can lead to inbreeding depression due to deleterious recessive mutations exposed in the homozygous state. The Thoroughbred racehorse has low levels of population genetic diversity, but the effects of genomic inbreeding in the population are unknown. Here, we quantified inbreeding based on runs of homozygosity (ROH) using 297 K SNP genotypes from 6128 horses born in Europe and Australia, of which 13.2% were unraced. We show that a 10% increase in inbreeding (F_ROH) is associated with a 7% lower probability of ever racing. Moreover, a ROH-based genome-wide association study identified a haplotype on ECA14 which, in its homozygous state, is linked to a 32.1% lower predicted probability of ever racing, independent of F_ROH. The haplotype overlaps a candidate gene, EFNA5, that is highly expressed in cartilage tissue, which when damaged is one of the most common causes of catastrophic musculoskeletal injury in racehorses. Genomics-informed breeding aiming to reduce inbreeding depression and avoid damaging haplotype carrier matings will improve population health and racehorse welfare.

The EPH/Ephrin System in Bone and Soft Tissue Sarcomas' Pathogenesis and Therapy: New Advancements and a Literature Review

Musculoskeletal sarcomas represent rare heterogenous malignancies of mesenchymal origin that can be divided in two distinct subtypes, bone and soft tissue sarcomas. Current treatment options combine the surgical excision of local tumors and multidrug chemotherapy to prevent metastatic widespread disease. Due to the grim prognosis that usually accompanies such tumors, researchers have attempted to shed light on the molecular pathways implicated in their pathogenesis in order to develop novel, innovative, personalized therapeutic strategies. Erythropoietin-producing human hepatocellular receptors (EPHs) are tyrosine-kinase transmembrane receptors that, along with their ligands, ephrins, participate in both tumor-suppressive or tumor-promoting signaling pathways in bone and soft tissue sarcomas. The EPH/ephrin axis orchestrates cancerous processes such as cell–cell and cell–substrate adhesion and enhances the remodeling of the intracellular cytoskeleton to stimulate the motility and invasiveness of sarcoma cells. The purpose of our study was to review published PubMed literature to extract results from in vitro, in vivo and clinical trials indicative of the role of EPH/ephrin signaling in bone and soft tissue sarcomas. Based on these reports, significant interactions between the EPH/ephrin signaling pathway and a plethora of normal and abnormal cascades contribute to molecular mechanisms enhancing malignancy during sarcoma progression. In addition, EPHs and ephrins are prospective candidates for diagnostic, monitoring and therapeutic purposes in the clinical setting against bone and soft tissue sarcomas.

Deer antler extract potentially facilitates xiphoid cartilage growth and regeneration and prevents inflammatory susceptibility by regulating multiple functional genes

BACKGROUND

Deer antler is a zoological exception due to its fantastic characteristics, including amazing growth rate and repeatable regeneration. Deer antler has been used as a key ingredient in traditional Chinese medicine relating to kidney and bone health for centuries. The aim of this study was to dissect the molecular regulation of deer antler extract (DAE) on xiphoid cartilage (XC).

METHODS

The DAE used in this experiment was same as the one that was prepared as previously described. The specific pathogen-free (SPF) grade Sprague-Dawley (SD) rats were randomly divided into blank group (n =10) and DAE group (n =10) after 1-week adaptive feeding. The DAE used in this experiment was same as the one that was prepared as previously described. The rats in DAE group were fed with DAE for 3 weeks at a dose of 0.2 g/kg per day according to the body surface area normalization method, and the rats in blank group were fed with drinking water. Total RNA was extracted from XC located in the most distal edge of the sternum. Illumina RNA sequencing (RNA-seq) in combination with quantitative real-time polymerase chain reaction (qRT-PCR) validation assay was carried out to dissect the molecular regulation of DAE on XC.

RESULTS

We demonstrated that DAE significantly increased the expression levels of DEGs involved in cartilage growth and regeneration, but decreased the expression levels of DEGs involved in inflammation, and mildly increased the expression levels of DEGs involved in chondrogenesis and chondrocyte proliferation.

CONCLUSIONS

Our findings suggest that DAE might serve as a complementary therapeutic regent for cartilage growth and regeneration to treat cartilage degenerative disease, such as osteoarthritis.

Unique transcriptomic signature of omental adipose tissue in Ossabaw swine: a model of childhood obesity

To better understand the impact of childhood obesity on intra-abdominal adipose tissue phenotype, a complete transcriptomic analysis using deep RNA-sequencing (RNA-seq) was performed on omental adipose tissue (OMAT) obtained from lean and Western diet-induced obese juvenile Ossabaw swine. Obese animals had 88% greater body mass, 49% greater body fat content, and a 60% increase in OMAT adipocyte area (all P < 0.05) compared with lean pigs. RNA-seq revealed a 37% increase in the total transcript number in the OMAT of obese pigs. Ingenuity Pathway Analysis showed transcripts in obese OMAT were primarily enriched in the following categories: 1) development, 2) cellular function and maintenance, and 3) connective tissue development and function, while transcripts associated with RNA posttranslational modification, lipid metabolism, and small molecule biochemistry were reduced. DAVID and Gene Ontology analyses showed that many of the classically recognized gene pathways associated with adipose tissue dysfunction in obese adults including hypoxia, inflammation, angiogenesis were not altered in OMAT in our model. The current study indicates that obesity in juvenile Ossabaw swine is characterized by increases in overall OMAT transcript number and provides novel data describing early transcriptomic alterations that occur in response to excess caloric intake in visceral adipose tissue in a pig model of childhood obesity.

Experimental hypoxia does not influence gene expression and protein synthesis of Eph receptors and ephrin ligands in human melanoma cells in vitro

Eph receptor tyrosine kinases and their ephrin ligands are considered to play important roles in melanoma progression and metastasis. Moreover, hypoxia is known to contribute to melanoma metastasis. In this study, the influence of experimental hypoxia on the expression and synthesis of EphA2 and EphB4, and their corresponding ligands ephrinA1, ephrinA5, and ephrinB2 was studied systematically in four human melanoma cell lines in vitro. Melanoma cell monolayer and spheroid cultures were used as both extrinsic and intrinsic hypoxia models. Hypoxic conditions were confirmed by analyzing hypoxia-inducible factors 1α or 2α expression, vascular endothelial growth factor expression, and cellular uptake of [F]fluoromisonidazole. In normoxia, EphA2, EphB4, ephrinA1, ephrinA5, and ephrinB2 expression was detectable in all cell lines to varying extents. Considerable protein synthesis of EphA2 was detected in all cell lines. However, no effect of experimental hypoxia on both Eph/ephrin expression and protein synthesis was observed. This contributes critically to the debate on the hypothesis that hypoxia regulates the Eph/ephrin system in melanoma.

Eph receptors and their ligands: promising molecular biomarkers and therapeutic targets in prostate cancer

Although at present, there is a high incidence of prostate cancer, particularly in the Western world, mortality from this disease is declining and occurs primarily only from clinically significant late stage tumors with a poor prognosis. A major current focus of this field is the identification of new biomarkers which can detect earlier, and more effectively, clinically significant tumors from those deemed "low risk", as well as predict the prognostic course of a particular cancer. This strategy can in turn offer novel avenues for targeted therapies. The large family of Receptor Tyrosine Kinases, the Ephs, and their binding partners, the ephrins, has been implicated in many cancers of epithelial origin through stimulation of oncogenic transformation, tumor angiogenesis, and promotion of increased cell survival, invasion and migration. They also show promise as both biomarkers of diagnostic and prognostic value and as targeted therapies in cancer. This review will briefly discuss the complex roles and biological mechanisms of action of these receptors and ligands and, with regard to prostate cancer, highlight their potential as biomarkers for both diagnosis and prognosis, their application as imaging agents, and current approaches to assessing them as therapeutic targets. This review demonstrates the need for future studies into those particular family members that will prove helpful in understanding the biology and potential as targets for treatment of prostate cancer.

Peritumoral small ephrinA5 isoform level predicts the postoperative survival in hepatocellular carcinoma

Background

EphrinA5, a member of Eph/Ephrin family, possesses two alternative isoforms, large ephrinA5 isoform (ephrinA5L) and small ephrinA5 isoform (ephrinA5S). EphrinA5L is a putative tumor suppressor in several types of human cancers. However, the role of ephrinA5S in hepato-carcinogenesis remains unclear. In this study, we evaluate the role of ephrinA5 isoforms in human hepatocellular carcinomas (HCC).

Methodology/Principal Findings

A total of 142 paired HCCs and peritumoral liver tissue was examined for relative expression of ephrinA5L and ephrinA5S by using quantitative real-time polymerase chain reaction. We analyzed their expression in relation to clinical parameters, disease-free survival and overall survival. Functional assays were performed to dissect the possible underlying mechanisms. Both ephrinA5L and ephrinA5S were significantly downregulated in HCCs, as compared to those in peritumoral tissue (p = 0.013 and 0.001). Univariate analysis demonstrated that ephrinA5S was positively correlated with old age and histological grade. In multivariate analysis, high ephrinA5S expression in peritumoral tissue had better disease-free survival (p = 0.002) and overall survival (p = 0.045) in patients with HCC after surgical resection. Functional analysis in HCC cell lines revealed that ephrinA5S had a more potent suppressive effect than ephrinA5L on cell proliferation (p<0.05) and migration (p<0.01). Furthermore, forced expression of both ephrinA5 isoforms in HCC cell lines significantly down-regulated epidermal growth factor receptor (EGFR) expression by promoting c-Cbl-mediated EGFR degradation.

Conclusions/Significance

EphrinA5S might be a useful prognostic biomarker for HCCs after surgical resection. EphrinA5, especially ephrinA5S, acts as a tumor suppressor in hepatocarcinogenesis. Peritumoral small ephrinA5 isoform level could determine the postoperative survival in hepatocellular carcinoma.

Gene expression changes in human lung cells exposed to arsenic, chromium, nickel or vanadium indicate the first steps in cancer

The complex process of carcinogenesis begins with transformation of a single cell to favor aberrant traits such as loss of contact inhibition and unregulated proliferation - features found in every cancer. Despite cancer's widespread prevalence, the early events that initiate cancer remain elusive, and without knowledge of these events cancer prevention is difficult. Here we show that exposure to As, Cr, Ni, or vanadium (V) promotes changes in gene expression that occur in conjunction with aberrant growth. We exposed immortalized human bronchial epithelial cells to one of four metals/metalloid for four to eight weeks and selected transformed clonal populations based upon anchorage independent growth of single cells in soft agar. We detected a metal-specific footprint of cancer-related gene expression that was consistent across multiple transformed clones. These gene expression changes persisted in the absence of the progenitor metal for numerous cell divisions. Our results show that even a brief exposure to a carcinogenic metal may cause many changes in gene expression in the exposed cells, and that from these many changes, the specific change(s) that each metal causes that initiate cancer likely arise.

Bone cell interactions through Eph/ephrin: bone modeling, remodeling and associated diseases

Bones cannot properly form or be maintained without cell-cell interactions through ephrin ligands and Eph receptors. Cell culture analysis and evaluation of genetic mouse models and human diseases reveal various ephrins and Eph functions in the skeletal system. Migration, attachment and spreading of mesenchymal stem cells are regulated by ephrinB ligands and EphB receptors. ephrinB1 loss-of-function is associated with craniofrontonasal syndrome (CFNS) in humans and mice. In bone remodeling, ephrinB2 is postulated to act as a “coupling stimulator.” In that case, bidirectional signaling between osteoclastic ephrinB2 and osteoblastic EphB4 suppresses osteoclastic bone resorption and enhances osteoblastic bone formation, facilitating the transition between these two states. Parathyroid hormone (PTH) induces ephrinB2 in osteoblasts and enhances osteoblastic bone formation. In contrast to ephrinB2, ephrinA2 acts as a “coupling inhibitor,” since ephrinA2 reverse signaling into osteoclasts enhances osteoclastogenesis and EphA2 forward signaling into osteoblasts suppresses osteoblastic bone formation and mineralization. Furthermore, ephrins and Ephs likely modulate pathological conditions such as osteoarthritis, rheumatoid arthritis, multiple myeloma and osteosarcoma. This review focuses on ephrin/Eph-mediated cell-cell interactions in bone biology.

EphrinA5 suppresses colon cancer development by negatively regulating epidermal growth factor receptor stability

Colon cancer is one of the most common human cancers worldwide. Owing to its aggressiveness and lethality, it is necessary to determine the mechanisms regulating the carcinogenesis of colon cancer. EphrinA5 has been reported to act as a putative tumor suppressor in glioma; however, little is known concerning the role of this protein in the context of colon cancer. To elucidate the biological significance of ephrinA5 in colon cancer, we examined ephrinA5 and epidermal growth factor receptor (EGFR) expression profiles in both colon cancer and normal tissues, using immunohistochemistry on a 96-spot tissue microarray. Gain-of-function and loss-of-function experiments were performed on the human colon cancer cell lines SW480 and WiDr to determine the biological effects of ephrinA5 in relation to cell proliferation, survival, and migration. It was found that ephrinA5 mRNA and protein levels were significantly reduced in colon cancer as compared with normal colon tissue specimens. EphrinA5 expression was also negatively associated with tumor differentiation and clinical stage. In colon cancer cell line models, ephrinA5 exerted an inhibitory effect on EGFR by promoting c-Cbl-mediated EGFR ubiquitination and degradation. EphrinA5 did not affect the transcriptional regulation of EGFR mRNA expression in colon cancer cells. Expression of ephrinA5 suppressed colon cancer cell proliferation, migration, and chemotherapeutic resistance. In conclusion, ephrinA5 inhibited colon cancer progression by promoting c-Cbl-mediated EGFR degradation. Our findings identify a novel mechanism that could be utilized to improve the therapeutic efficiency of EGFR-targeting strategies.

Novel prognostic markers in the serum of patients with castration-resistant prostate cancer derived from quantitative analysis of the pten conditional knockout mouse proteome

BACKGROUND

Metastatic castration-resistant prostate cancer (mCRPC) is associated with a poor outcome. Prognostic information is useful and aids treatment decisions. However, current nomograms based on clinical parameters alone have weak prognostic accuracy. Therefore, the identification of new prognostic serum biomarkers could be useful.

OBJECTIVES

To assess if quantitative analysis of the phosphatase and tensin homolog (Pten) conditional knockout mouse proteome reveals significant prognostic biomarkers in mCRPC and to compare the accuracy of these biomarkers with known prognostic factors.

DESIGN, SETTING, AND PARTICIPANTS

Fifty-seven patients with mCRPC were evaluated retrospectively. Prognostic factors used in clinical nomograms were assessed from the records. New candidate biomarkers in patients' sera were derived using a cancer genetics-guided model we recently described, screening the murine Pten-dependent glycoproteome.

MEASUREMENTS

Quantification in patients' sera was performed by either mass spectrometry-based targeted proteomics or enzyme-linked immunosorbent assays. Prognostic biomarkers for survival were identified based on Kaplan-Meier models. In a second step, random forest analysis was performed to identify a prognostic signature combined from the pooled data of known predictors and newly identified biomarkers.

RESULTS AND LIMITATIONS

With univariate analysis, 13 new significant prognostic factors for survival in the sera of mCRPC patients were found with a Bonferroni-corrected level of significance <5%. Random forest analysis revealed a five-factor predictor (thrombospondin 1; C-reactive protein; poliovirus receptor-related 1; ephrin-A5; and membrane metallo-endopeptidase) with an accuracy of 96% and 94% for 12- and 24-mo survival, respectively. This means that, in our dataset, the error was reduced by 15% compared to using the Halabi et al. nomogram. The retrospective nature of the work and absence of a validating dataset is the major limitation of this work.

CONCLUSIONS

Analysis of the serum proteome in mCRPC patients based on our Pten conditional knockout model, combined with known prognostic factors, potentially improves accuracy of prognostic nomograms. These newly identified markers have to be validated in prospective studies.

A role for DNA methylation in regulation of EphA5 receptor expression in the mouse retina

Understanding the mechanisms regulating expression of retinal ganglion cell (RGC) specific and axon-guidance genes during development and in retinal stem cells will be critical for successful optic nerve regeneration. Müller glia have some characteristics of retinal stem cells but in mammals have demonstrated limited potential to differentiate into RGCs. Chromatin remodeling through histone deacetylation and DNA methylation are a potential mechanism for silencing genes necessary for neuronal differentiation of glial cells. We investigated DNA methylation as a mechanism for regulating expression of mouse EphA5, one member of a large family of ephrin receptor genes that regulate patterning of the topographic connections of RGCs during visual system development. We analyzed spatial and age-related patterns of EphA5 promoter methylation by bisulfite sequencing and mRNA expression by quantitative RT-PCR in the mouse retina. The CpG island in the EphA5 promoter was hypomethylated in the retina and showed no change in overall methylation with age, despite a decline in EphA5 mRNA expression levels in the adult retina. In the nasal retina of post-natal day 0 mice, there was a modest, but statistically significant increase in methylation. Increased methylation corresponded with lower levels of receptor mRNA expression in the nasal retina. We cloned the EphA5 promoter and found that site-specific differences in methylation could preferentially activate or repress promoter activity in transient transfections of rat retinal progenitor cells (R28) using luciferase assays. In sphere cultures generated by EGF/FGF2 stimulation of conditionally immortalized mouse Müller glia (ImM10), EphA5 promoter was hypermethylated and EphA5 mRNA was not detected. Demethylation using 5-azadeoxycytidine (AzadC) resulted in a significant decrease of methylation of the EphA5 promoter and re-expression of the EphA5 mRNA. The inverse relationship between EphA5 promoter methylation and mRNA expression is consistent with a role for DNA methylation in modulating the spatial patterns of EphA5 gene expression in the retina and in silencing EphA5 expression in ImM10 cells. The robust up-regulation of EphA5 in ImM10 cells following demethylation suggests that modulation of chromatin structure may be a useful approach for promoting expression of silenced developmental genes and increasing the neurogenic potential of Müller glia.