The role of EphA7 in different tumors

Targeted demethylation of the EphA7 promoter inhibits tumorigenesis via the SP1/DNMT1 and PI3K/AKT axes and improves the response to multiple therapies in cervical cancer

Aberrant methylation of the EphA7 promoter has been observed in cervical cancer (CC); however, its precise function and role in CC remain largely unknown. In this study, we investigated the role and molecular mechanisms of EphA7 promoter methylation in cervical carcinogenesis. First, our results indicated that the reactivation of EphA7 expression via a CRISPR demethylation tool (dCas9-Tet1) had antitumor effects. It restrained tumor proliferation and invasion while promoting apoptosis via the PI3K/AKT signaling pathway in both CaSki and SiHa cells. The upstream interacting factors were subsequently captured by CRISPR-mediated pull-down in situ, and the result revealed that SP1 and MAZ interacted with the promoter of EphA7. However, the perturbation results revealed that EphA7 expression was associated with SP1/DNMT1 but not MAZ. Furthermore, 17-β-estradiol (E2) can upregulate EphA7 expression through demethylation via the SP1/DNMT1 axis. A rescue experiment revealed that interference with SP1 expression could restore the effect of E2 on increasing the expression of EphA7 by upregulating estrogen receptor expression. In addition, EphA7 demethylation reduced the half-maximal inhibitory concentration (IC50) of cisplatin and paclitaxel. Pooled analysis revealed that EphA7 promoter hypermethylation was positively correlated with tumor purity but negatively correlated with immune cell infiltration, cytotoxic T lymphocyte (CTL) and immune checkpoint (IC) activity, and the expression of EphA7 was significantly positively correlated with tumor mutational burden (TMB), microsatellite instability (MSI) and the presence of single nucleotide variant (SNV) neoantigens, suggesting a better prognosis for patients with EphA7 promoter hypomethylation and high expression. Collectively, these findings indicate that targeted demethylation of the EphA7 promoter and restoration of endogenous EphA7 expression by dCas9-Tet1 are promising therapeutic approaches and are favorable for the prognosis of CC patients.

Altered TP53, CDKN2A, ATM, EPHA7, POT1, CHEK1, GRIN2A, and EGFR Predict Shorter Survival in Penile Squamous Cell Carcinoma

Penile squamous cell carcinoma (pSCC) represents an uncommon malignancy characterized by stagnant mortality, psychosexual distress, and a highly variable prognosis. Currently, the World Health Organization distinguishes between human papillomavirus (HPV)-related and HPV-independent pSCC. Recently, there has been an evolving line of research documenting the enrichment of HPV-independent pSCC with a high tumor mutational burden (TMB) and programmed death ligand-1 expression, as well as clusters of genes associated with HPV status. In this study, we conducted comprehensive next-generation sequencing DNA profiling of 146 pSCC samples using a panel consisting of 355 genes associated with tumors. This profiling was correlated with immunohistochemical markers and prognostic clinical data. A survival analysis of recurrent genomic events (found in ≥10 cases) was performed. TP53, CDKN2A, ATM, EPHA7, POT1, CHEK1, GRIN2A, and EGFR alterations were associated with significantly shortened overall survival in univariate and multivariate analysis. HPV positivity, diagnosed through both p16 immunohistochemistry and HPV DNA analysis, displayed no impact on survival but was associated with high-grade, lymphatic invasion, programmed death ligand-1 negativity/weak expression, and low TMB. FAT1, TP53, CDKN2A, CASP8, and HRAS were more often mutated in HPV-independent pSCC. In contrast, HPV-associated pSCCs were enriched by EPHA7, ATM, GRIN2A, and CHEK1 mutations. PIK3CA, FAT1, FBXW7, and KMT2D mutations were associated with high TMB. NOTCH1, TP53, CDKN2A, POT1, KMT2D, ATM, CHEK1, EPHA3, and EGFR alterations were related to adverse clinicopathologic signs, such as advanced stage, high tumor budding, and lymphovascular invasion. We detected 160 alterations with potential treatment implications, with 21.2% of samples showing alterations in the homologous recombination repair pathway. To the best of our knowledge, this study describes the largest cohort of pSCC with complex molecular pathologic, clinical, and prognostic analysis correlating with prognosis.

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.

Biological Significance of EphB4 Expression in Cancer

Eph receptors and their Eph receptor-interacting (ephrin) ligands comprise a vital cell communication system with several functions. In cancer cells, there was evidence of bilateral Eph receptor signaling with both tumor-suppressing and tumor-promoting actions. As a member of the Eph receptor family, EphB4 has been linked to tumor angiogenesis, growth, and metastasis, which makes it a viable and desirable target for drug development in therapeutic applications. Many investigations have been conducted over the last decade to elucidate the structure and function of EphB4 in association with its ligand ephrinB2 for its involvement in tumorigenesis. Although several EphB4-targeting drugs have been investigated, and some selective inhibitors have been evaluated in clinical trials. This article addresses the structure and function of the EphB4 receptor, analyses its possibility as an anticancer therapeutic target, and summarises knowledge of EphB4 kinase inhibitors. To summarise, EphB4 is a difficult but potential treatment option for cancers.

miRNAs as potential game-changers in melanoma: A comprehensive review

Melanoma is the sixth most frequent malignancy. It represents 1.7% of all cancer cases worldwide. Many risk factors are associated with melanoma including ultraviolet radiation skin phenotype, Pigmented Nevi, Pesticides, and genetic and epigenetic factors. Of the main epigenetic factors affecting melanoma are microribonucleic acids (miRNAs). They are short nucleic acid chains that have the potential to prevent the expression of a number of target genes. They could target a number of genes related to melanoma initiation, stemness, angiogenesis, apoptosis, proliferation, and potential resistance to treatment. Additionally, they can control several melanoma signaling pathways, including P53, WNT/-catenin, JAK/STAT, PI3K/AKT/mTOR axis, TGF- β, and EGFR. MiRNAs also play a role in the resistance of melanoma to essential treatment regimens. The stability and abundance of miRNAs might be important factors enhancing the use of miRNAs as markers of prognosis, diagnosis, stemness, survival, and metastasis in melanoma patients.