The putative tumor suppressor gene EphA3 fails to demonstrate a crucial role in murine lung tumorigenesis or morphogenesis

Comprehensive analysis of Epha10 as a predictor of clinical prognosis and immune checkpoint therapy efficacy in non-small cell lung cancer

The EphA family belongs to a large group of membrane receptor tyrosine kinases. Emerging evidence indicates that the EphA family participates in tumour occurrence and progression. Nonetheless, the expression patterns and prognostic values of the nine EphAs in non-small cell lung cancer (NSCLC) have rarely been studied before. In the current study, we comprehensively analysed the expression and prognostic role of EphA family members by different means. The Cancer Genome Atlas and Gene Expression Profiling Interactive Analysis databases were used to investigate the expression of EphAs in NSCLC. The cBioPortal database was applied to analyse the prognostic values and genetic mutations of EphAs.We discovered that the expression of EphA10 was significantly higher in NSCLC tissues than in adjacent noncancerous tissues, and survival analyses showed that a higher level of EphA10 predicted poor prognosis. Further exploration into the role of EphA10 by ESTIMATE, CIBERSORT, and ssGSEA analysis found that it was also related to immune infiltration and higher expression of targets of ICI targets. In conclusion, this study revealed that among the EphA family members, EphA10 played an oncogenic role and was a promising biomarker for poor prognosis and better immunotherapy response in NSCLC.

Eph receptors and ephrins in cancer progression

Evidence implicating Eph receptor tyrosine kinases and their ephrin ligands (that together make up the 'Eph system') in cancer development and progression has been accumulating since the discovery of the first Eph receptor approximately 35 years ago. Advances in the past decade and a half have considerably increased the understanding of Eph receptor-ephrin signalling mechanisms in cancer and have uncovered intriguing new roles in cancer progression and drug resistance. This Review focuses mainly on these more recent developments. I provide an update on the different mechanisms of Eph receptor-ephrin-mediated cell-cell communication and cell autonomous signalling, as well as on the interplay of the Eph system with other signalling systems. I further discuss recent advances in elucidating how the Eph system controls tumour expansion, invasiveness and metastasis, supports cancer stem cells, and drives therapy resistance. In addition to functioning within cancer cells, the Eph system also mediates the reciprocal communication between cancer cells and cells of the tumour microenvironment. The involvement of the Eph system in tumour angiogenesis is well established, but recent findings also demonstrate roles in immune cells, cancer-associated fibroblasts and the extracellular matrix. Lastly, I discuss strategies under evaluation for therapeutic targeting of Eph receptors-ephrins in cancer and conclude with an outlook on promising future research directions.

Antibody-mediated depletion of CCR10+EphA3+ cells ameliorates fibrosis in IPF

Idiopathic pulmonary fibrosis (IPF) is characterized by aberrant repair that diminishes lung function via mechanisms that remain poorly understood. CC chemokine receptor (CCR10) and its ligand CCL28 were both elevated in IPF compared with normal donors. CCR10 was highly expressed by various cells from IPF lungs, most notably stage-specific embryonic antigen-4-positive mesenchymal progenitor cells (MPCs). In vitro, CCL28 promoted the proliferation of CCR10+ MPCs while CRISPR/Cas9-mediated targeting of CCR10 resulted in the death of MPCs. Following the intravenous injection of various cells from IPF lungs into immunodeficient (NOD/SCID-γ, NSG) mice, human CCR10+ cells initiated and maintained fibrosis in NSG mice. Eph receptor A3 (EphA3) was among the highest expressed receptor tyrosine kinases detected on IPF CCR10+ cells. Ifabotuzumab-targeted killing of EphA3+ cells significantly reduced the numbers of CCR10+ cells and ameliorated pulmonary fibrosis in humanized NSG mice. Thus, human CCR10+ cells promote pulmonary fibrosis, and EphA3 mAb-directed elimination of these cells inhibits lung fibrosis.

EPHA3 Contributes to Epigenetic Suppression of PTEN in Radioresistant Head and Neck Cancer

EPHA3, a member of the EPH family, is overexpressed in various cancers. We demonstrated previously that EPHA3 is associated with radiation resistance in head and neck cancer via the PTEN/Akt/EMT pathway; the inhibition of EPHA3 significantly enhances the efficacy of radiotherapy in vitro and in vivo. In this study, we investigated the mechanisms of PTEN regulation through EPHA3-related signaling. Increased DNA methyltransferase 1 (DNMT1) and enhancer of zeste homolog 2 (EZH2) levels, along with increased histone H3 lysine 27 trimethylation (H3K27me3) levels, correlated with decreased levels of PTEN in radioresistant head and neck cancer cells. Furthermore, PTEN is regulated in two ways: DNMT1-mediated DNA methylation, and EZH2-mediated histone methylation through EPHA3/C-myc signaling. Our results suggest that EPHA3 could display a novel regulatory mechanism for the epigenetic regulation of PTEN in radioresistant head and neck cancer cells.

Critical role of EphA3 in cancer and current state of EphA3 drug therapeutics

The erythropoietin-producing human hepatocellular (Eph) receptors are transmembrane glycoprotein members of the tyrosine kinase receptors family. The Ephs may bind to various ephrin ligands resulting in the phosphorylation of their tyrosine kinase domain and the activation of the Eph receptor. In this review we focus on EphA3, one receptor of the 14 different Ephs, as it carries out both redundant and restricted functions in the germline development of mammals and in the maintenance of various adult tissues. The loss of EphA3 regulation is correlated with various human malignancies, the most notable being cancer. This receptor is overexpressed and/or mutated in multiple tumors, and is also associated with poor prognosis and decreased survival in patients. Here we highlight the role of EphA3 in normal and malignant tissues that are specific to cancer; these include hematologic disorders, gastric cancer, glioblastoma multiforme, colorectal cancer, lung cancer, renal cell carcinoma, and prostate cancer. Moreover, various anticancer agents against EphA3 have been developed to either inhibit its kinase domain activity or to function as agonists. Thus, we examine the most potent small molecule drugs and mAb-based therapeutics against EphA3 that are currently in pre-clinical or clinical stages.

A panel of protein kinase high expression is associated with postoperative recurrence in cholangiocarcinoma

Background

Cancer recurrence is one of the most concerning clinical problems of cholangiocarcinoma (CCA) patients after treatment. However, an identification of predictive factor on Opisthorchis viverrini (OV)-associated CCA recurrence is not well elucidated. In the present study, we aimed to investigate the correlation of twelve targeted protein kinases with CCA recurrence.

Methods

Twelve protein kinases, epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2, 3, 4 (HER2, HER3, HER4), vascular endothelial growth factor receptor 3 (VEGFR3), vascular endothelial growth factor-C (VEGF-C), erythropoietin-producing hepatocellular carcinoma receptor type-A3 (EphA3), EphrinA1, phosphor-serine/threonine kinase 1 (p-Akt1), serine/threonine kinase 1 (Akt1), beta-catenin and protein Wnt5a (Wnt5a) were examined using immunohistochemistry. Pre-operative serum tumor markers, CA19–9 and CEA were also investigated.

Results

Among twelve protein kinases, EGFR, HER4, and EphA3 were associated with tumor recurrence status, recurrence-free survival (RFS) and overall survival (OS). Multivariate cox regression demonstrated that EGFR, HER4, EphA3 or the panel of high expression of these proteins was an independent prognostic factor for tumor recurrence. The combination of high expression of these proteins with a high level of CA19–9 could improve the predictive ability on tumor recurrence. Moreover, the patients were stratified more accurately when analyzed using the combination of high expression of these proteins with primary tumor (T) or lymph node metastasis (N) status.

Conclusion

EGFR, HER4, EphA3 or the panel of high expression of these proteins is an independent prognostic factor for post-operative CCA recurrence.

EPHA3 enhances macrophage autophagy and apoptosis by disrupting the mTOR signaling pathway in mice with endometriosis

Background: Endometriosis is a chronic fibrotic disease characterized by agonizing pelvic pain and low fertility, mainly affecting middle-aged women. The aim of the present study is to assess the potential effects of erythropoietin-producing hepatocellular carcinoma A3 (EPHA3) on endometriosis, with emphasis on the autophagy and apoptosis of macrophages via inhibition of the mammalian target of rapamycin (mTOR) signaling pathway.

Methods: The mouse models of endometriosis were established followed by culturing the macrophages and macrophage transfection via the EPHA3 vector, siRNA EPHA3, and RAPA (an inhibitor of the mTOR signaling pathway). The expression of EPHA3, related factors in the mTOR signaling pathway, macrophage autophagy (autophagy-related gene 3 (Atg3), light chain 3-I (LC3-I), light chain 3-II (LC3-II) and Beclin1) and apoptosis (B-cell lymphoma-2 (bcl-2), bax and fas) were all detected and documented, respectively. The changes of autophagic lysosomes and the apoptosis of macrophages in each group following transfection were also inspected and detected.

Results: The results of the in silico analysis ascertained EPHA3 to be a candidate gene of endometriosis. After successful modeling, the uterine tissues of endometriosis mice presented with a low expression of EPHA3 and activated mTOR signaling pathway. Overexpression of EPHA3 inhibited the activation of the mTOR signaling pathway, down-regulated bcl-2 expression, up-regulated the expression of Atg3, LC3-II/LC3-I, Beclin1, bax and fas, and also promoted the autophagy and apoptosis of macrophages in endometriosis mice.

Conclusion: Altogether, EPHA3 could potentially promote the autophagy and apoptosis of macrophages in endometriosis via inhibition of the mTOR signaling pathway, highlighting the potential of EPHA3 as the target to treat endometriosis.

CCR10+ epithelial cells from idiopathic pulmonary fibrosis lungs drive remodeling

Idiopathic pulmonary fibrosis (IPF) is a devastating fibrotic lung disease of unknown etiology and limited therapeutic options. In this report, we characterize what we believe is a novel CCR10+ epithelial cell population in IPF lungs. There was a significant increase in the percentage of CCR10+ epithelial cells in IPF relative to normal lung explants and their numbers significantly correlated to lung remodeling in humanized NSG mice. Cultured CCR10-enriched IPF epithelial cells promoted IPF lung fibroblast invasion and collagen 1 secretion. Single-cell RNA sequencing analysis showed distinct CCR10+ epithelial cell populations enriched for inflammatory and profibrotic transcripts. Consistently, cultured IPF but not normal epithelial cells induced lung remodeling in humanized NSG mice, where the number of CCR10+ IPF, but not normal, epithelial cells correlated with hydroxyproline concentration in the remodeled NSG lungs. A subset of IPF CCR10hi epithelial cells coexpress EphA3 and ephrin A signaling induces the expression of CCR10 by these cells. Finally, EphA3+CCR10hi epithelial cells induce more consistent lung remodeling in NSG mice relative to EphA3-CCR10lo epithelial cells. Our results suggest that targeting epithelial cells, highly expressing CCR10, may be beneficial in IPF.

Targeting Eph/ephrin system in cancer therapy

It is well established that the Eph/ephrin system plays a central role in the embryonic development, with minor implications in the physiology of the adult. However, it is overexpressed and deregulated in a variety of tumors, with a primary involvement in tumorigenesis, tumor angiogenesis, metastasis development, and cancer stem cell regeneration. Targeting the Eph/ephrin system with biologicals, including antibodies and recombinant proteins, reduces tumor growth in animal models of hematological malignancies, breast, prostate, colon, head and neck cancers and glioblastoma. Currently, some of these biopharmaceutical agents are under investigations in phase I or phase II clinical trials. Peptides and small molecules targeting protein-protein-interaction (PPI) are in the late preclinical phase where they are showing promising activity in models of glioblastoma, ovarian and lung cancer. The present review summarizes the most critical findings proposing the Eph/ephrin signaling system as a new target in molecularly targeted oncology.

EPHA3 regulates the multidrug resistance of small cell lung cancer via the PI3K/BMX/STAT3 signaling pathway

Multidrug resistance (MDR) is a major obstacle to the treatment of small cell lung cancer (SCLC). EPHA3 has been revealed to be the most frequently mutated Eph receptor gene in lung cancer with abnormal expression. Growing evidence indicates that the signaling proteins of EPHA3 downstream, including PI3K, BMX and STAT3, play crucial roles in tumorigenesis and cancer progression. To explore the possible role of EPHA3 in MDR, we assessed the influence of EPHA3 on chemoresistance, cell cycle, apoptosis, and tumor growth, as well as the relationship between EPHA3 and the expression of PI3K, BMX, and STAT3 in SCLC. We observed that overexpression of EPHA3 in SCLC cells decreased chemoresistance by increasing apoptosis and inducing G0/G1 arrest, accompanied by reduced phosphorylation of PI3K/BMX/STAT3 signaling pathway. Knockdown of EPHA3 expression generated a resistant phenotype of SCLC, as a result of decreased apoptosis and induced G2/M phase arrest. And re-expression of EPHA3 in these cells reversed the resistant phenotype. Meanwhile, increased phosphorylation of PI3K/BMX/STAT3 signaling pathway was observed in these cells with EPHA3 deficiency. Notably, both PI3K inhibitor (LY294002) and BMX inhibitor (LFM-A13) impaired the chemoresistance enhanced by EPHA3 deficiency in SCLC cell lines. Furthermore, EPHA3 inhibited growth of SCLC cells in vivo and was correlated with longer overall survival of SCLC patients. Thus, we first provide the evidences that EPHA3 is involved in regulating the MDR of SCLC via PI3K/BMX/STAT3 signaling and may be a new therapeutic target in SCLC.