EPHA2 antisense RNA modulates EPHA2 mRNA levels in basal-like/triple-negative breast cancer cells

Ephrin type-A receptor 2-antisense RNA1/2 promote proliferation and migration of MDA-MB-231 cells through EPHA2-dependent Ras signaling pathway mediated by MAPK8/JNK1, MAPK9/JNK2-NFATC2/NFAT1 and JUND

Ephrin type-A receptor 2 (EPHA2) is a receptor tyrosine kinase that is overexpressed in a variety of cancers, including breast cancer. EPHA2 expression may be causally related to tumorigenesis; therefore, it is important to understand how EPHA2 expression is regulated. We previously reported that EPHA2 antisense RNA (EPHA2-AS), a natural antisense transcript, is an important modulator of EPHA2 mRNA levels and hence production of EPHA2 protein. EPHA2-AS encodes two splice variants, EPHA2-AS1 and EPHA2-AS2. The two variants are constitutively expressed in a concordant manner with EPHA2 mRNA in human breast adenocarcinoma cell lines and in patient samples, with the highest levels detected in the basal-like/triple-negative molecular subtype of breast cancer cells. In this study, we investigated the mechanism of EPHA2-AS1/2 in triple-negative breast cancer using MDA-MB-231 cells. We performed RNA-seq transcriptome analyses of MDA-MB-231 cells treated with AHCC®, which suppressed expression of EPHA2-AS1/2 and EPHA2 mRNA, and EPHA2-AS1/2-silenced MDA-MB-231 cells. Bioinformatics analyses identified 545 overlapping differentially expressed genes that were significantly up- or down-regulated by these treatments. Subsequent functional enrichment analyses of the overlapping genes in combination with in vitro assays indicated that EPHA2-AS1/2 may promote the proliferation and migration of MDA-MB-231 cells through the EPHA2-dependent Ras signaling pathways mediated by MAPK8/JNK1, MAPK9/JNK2-NFATC2/NFAT1 (proliferation and migration) and JUND (migration). These results thus suggest that EPHA2-AS1/2 may represent a potential molecular target for triple-negative breast cancer treatment.

Lupeol synergizes with 5-fluorouracil to combat c-MET/EphA2 mediated chemoresistance in triple negative breast cancer

Triple-negative breast cancer (TNBC) is the most elusive subtype of breast cancer that encounters treatment dilemmas owing to the paucity of druggable targets. We found hyperactivation of c-MET and ephrin type-A receptor 2 (EphA2) in patients treated with 5FU driven chemotherapy which correlated with lower disease-free survival. However, silencing of both these genes resulted in a marked decrease in the invasive, migratory, and tumorigenic potential of TNBC cells, indicating that a dual target strategy is actionable. Lupeol is a phytochemical, with potent anticancer efficacy and minimal side effects in preclinical studies. A synergistic strategy with 5FU and Lupeol elicited promising anticancer responses in vitro, in vivo, and in patient-derived ex vivo tumor culture models. This synergistic regimen is effective, even in the presence of HGF, which mechanistically orchestrates the activation of c-MET and EphA2. These data lay the foundation for the clinical validation of this combination therapy for TNBC patients.

LINC02086 promotes cell viability and inhibits cell apoptosis in breast cancer by sponging miR-6757-5p and up-regulating EPHA2

BACKGROUND

Long non-coding RNAs (lncRNAs) are critical regulators in the initiation and progression of breast cancer. Our study aims to characterize the functions of LINC02086 which few published in breast cancer and decipher the downstream molecular mechanisms.

METHODS

LINC02086 expression is tested in RNA-seq data from GEPIA database, tumor tissue samples from hospital patients and breast cancer cell lines. LINC02086 was silenced or overexpressed by lenti-virus-mediated shRNAs, or pLVX-Puro plasmids. Luciferase reporter assay and RNA pull-down assay were applied to study interactions between LINC02086, miR-6757-5p and ephrin type-A receptor 2 (EPHA2). LINC02086-silencing MCF-7 cells were injected into mice to establish xenograft animal models.

RESULTS

Using RNA-seq data, tumor tissue samples and breast cancer cells, LINC02086 was consistently found to be up-regulated in breast cancer, and correlated with poorer prognosis. LINC02086 knockdown decreased cell viability, promoted cell apoptosis and suppressed tumor growth. LINC02086 interacted with miR-6757-5p that interacted with EPHA2.LINC02086 expression was negatively correlated with miR-6757-5p expression (r = -0.5698, P < 0.001) but was positively correlated with EPHA2 expression (r = 0.5061, P < 0.001). miR-6757-5p expression was negatively correlated with EPHA2 expression (r = -0.5919, P < 0.001). LINC02086 regulated EPHA2 via miR-6757-5p. miR-6757-5p/EPHA2 axis was a mediator of the effect of LINC02086 on cell viability and apoptosis.

CONCLUSION

LINC02086 increases cell viability and decreases apoptotic cells in breast cancer by sponging miR-6757-5p to upregulate EPHA2. This study presents LINC02086/miR-6757-5p/EPHA2 axis as promising therapeutic targets for breast cancer intervention.

Study on the Relationship Between Differentially Expressed Proteins in Breast Cancer and Lymph Node Metastasis

INTRODUCTION

Lymph node metastasis is a cause of poor prognosis in breast cancer. Mass spectrometry-based proteomics aims to map the protein landscapes of biological samples and profile tumors more comprehensively. Here, proteomics was employed to identify differentially expressed proteins (DEPs) that were associated with lymph node metastasis.

METHODS

Tandem mass tag (TMT) quantitative proteomic approaches were applied for extensive profiling of conditioned medium of MDA-MB-231 and MCF7 cell lines and serums of patients who did or did not have lymph node metastasis, and DEPs were analyzed by bioinformatics. Furthermore, potential secreted or membrane proteins MUC5AC, ITGB4, CTGF, EphA2, S100A4, PRDX2, and PRDX6 were selected for verification in 114 tissue microarray samples of breast cancer using the immunohistochemical method. The relevant data was analyzed and processed by independent sample t test, chi-square test, or Fisher's exact test using SPSS 22.0 software.

RESULTS

In the conditioned medium of MDA-MB-231 cell lines, 154 proteins were upregulated, while 136 were downregulated compared to those of MCF7. In the serum of patients with breast cancer and lymph node metastasis, 17 proteins were upregulated, and 5 proteins were downregulated compared to those without lymph node metastasis. Furthermore, according to tissue verification, CTGF, EphA2, S100A4, and PRDX2 were associated with breast cancer lymph node metastasis.

CONCLUSION

Our study provides a new perspective for the understanding of the role of DEPs (especially CTGF, EphA2, S100A4, and PRDX2) in the development and metastasis of breast cancer. They could become potential diagnostic and prognostic biomarkers and therapeutic targets.

COMBINATION THERAPY WITH A SENSE OLIGONUCLEOTIDE TO INDUCIBLE NITRIC OXIDE SYNTHASE MRNA AND HUMAN SOLUBLE THROMBOMODULIN IMPROVES SURVIVAL OF SEPSIS MODEL RATS AFTER PARTIAL HEPATECTOMY

ABSTRACT

Sepsis after a major hepatectomy is a critical problem. In septic shock, the inflammatory mediator, nitric oxide (NO), is overproduced in hepatocytes and macrophages. The natural antisense (AS) transcripts, non-coding RNAs, are transcribed from a gene that encodes inducible nitric oxide synthase (iNOS). iNOS AS transcripts interact with and stabilize iNOS mRNAs. A single-stranded "sense oligonucleotide" (designated as SO1) corresponding to the iNOS mRNA sequence inhibits mRNA-AS transcript interactions and reduces iNOS mRNA levels in rat hepatocytes. In contrast, recombinant human soluble thrombomodulin (rTM) treats disseminated intravascular coagulopathy by suppressing coagulation, inflammation, and apoptosis. In this study, the combination therapy of SO1 and a low dose of rTM was evaluated for hepatoprotection in a rat septic shock model after partial hepatectomy. Rats underwent 70% hepatectomy, followed by intravenous (i.v.) injection of lipopolysaccharide (LPS) after 48 h. SO1 was injected (i.v.) simultaneously with LPS, whereas rTM was injected (i.v.) 1 h before LPS injection. Similarly to our previous report, SO1 increased survival after LPS injection. When rTM, which has different mechanisms of action, was combined with SO1, it did not interfere with the effect of SO1 and showed a significant increase in survival compared with LPS alone treatment. In serum, the combined treatment decreased NO levels. In the liver, the combined treatment inhibited iNOS mRNA and protein expression. A decreased iNOS AS transcript expression by the combined treatment was also observed. The combined treatment decreased mRNA expression of the inflammatory and pro-apoptotic genes while increasing that of the anti-apoptotic gene. Furthermore, the combined treatment reduced the number of myeloperoxidase-positive cells. These results suggested that the combination of SO1 and rTM has therapeutic potential for sepsis.

Knock-down of amh transcription by antisense RNA reduces FSH and increases follicular atresia in female Oreochromis niloticus

Anti-Müllerian hormone (Amh) plays an important role in regulating gonad development in teleosts. However, little is known about the effects of Amh on follicle development. In this study, we transfected the vector containing antisense RNA fragments of the amh gene to produce Nile tilapia, Oreochromis niloticus, with knocked-down Amh function in vivo. The results confirmed that the antisense RNA effectively inhibited amh transcription and Amh protein expression in female tilapia ovarian tissue. At 180 days of age, compared with control fish, female tilapia with knocked-down Amh function showed significantly increased growth and significantly decreased ovary weight and gonadosomatic index (P < 0.05). Female fish in the control group had ruddy-colored external genitalia, eggs extruded from the abdomen when gently squeezed, and most oocytes were developmental stage V. In contrast, the external genitalia of female fish with knocked-down Amh function did not have the ruddy color, no eggs extruded from the abdomen when squeezed, most oocytes were at developmental stages II and III, and considerable follicular atresia was apparent. At 180 days of age, the transcript levels of amhrII, cyp19a1a, foxl2 and sox9b in ovarian tissue, and the titers of luteinizing hormone, follicle stimulating hormone, and estradiol in the serum, were significantly lower in fish with knocked-down Amh function than in control fish (P < 0.05). We concluded that decreased serum hormone levels and an abnormal AMH signal delayed development and caused follicular degeneration in Nile tilapia with knocked-down Amh function. These findings show that antisense RNA is a feasible approach for gene silencing in fish, and represents an accurate and effective strategy to study gene function.

The role of EphA7 in different tumors

Ephrin receptor A7 (EphA7) is a member of the Eph receptor family. It is widely involved in signal transduction between cells, regulates cell proliferation and differentiation, and participates in developing neural tubes and brain. In addition, EphA7 also has a dual role of tumor promoter and tumor suppressor. It can participate in cell proliferation, migration and apoptosis through various mechanisms, and affect tumor differentiation, staging and prognosis. EphA7 may be a potential diagnostic marker and tumor treatment target. This article reviews the effects of EphA7 on a variety of tumor biological processes and pathological characteristics, as well as specific effects and regulatory mechanisms.

MetaLnc9-Antisense RNA Contributes to Lung Cancer Metastasis via Modulating RNA-RNA Duplex with MetaLnc9

Lung cancer is a common life-threatening tumor with high malignancy and high invasiveness. Long non-coding RNAs (lncRNAs) are involved in almost every stage of tumor initiation and progression. Here, we identified an antisense lncRNA, MetaLnc9 antisense (Metalnc9-AS), which arises from the antisense strand of Metalnc9, located on chr9q34.11, while its biological function and mechanism are not clear in lung cancer. In this study, we demonstrated that the expression of Metalnc9-AS was upregulated in non-small cell lung cancer (NSCLC) tissues compared with corresponding non-tumorous tissues. The gain of MetaLnc9-AS was highly associated with the malignant features of NSCLC. Overexpression of MetaLnc9-AS enhanced tumor metastasis in vitro and in vivo. Mechanically, MetaLnc9-AS could form an RNA-RNA hybrid with its cognate sense counterpart, MetaLnc9, to regulate its expression in NSCLC cells, and that such complexes were protected from ribonuclease degradation. Thus, Metalnc9-AS might be a potential and effective treatment for NSCLC.

High-Throughput In Vitro Gene Expression Profile to Screen of Natural Herbals for Breast Cancer Treatment

Breast cancer has surpassed lung cancer as the most commonly diagnosed cancer in women worldwide. Some therapeutic drugs and approaches could cause side effects and weaken the immune system. The combination of conventional therapies and traditional Chinese medicine (TCM) significantly improves treatment efficacy in breast cancer. However, the chemical composition and underlying anti-tumor mechanisms of TCM still need to be investigated. The primary aim of this study is to provide unique insights to screen the natural components for breast cancer therapy using high-throughput transcriptome analysis. Differentially expressed genes were identified based on two conditions: single samples and groups were classified according to their pharmaceutical effect. Subsequently, the sample treated with E. cochinchinensis Lour. generated the most significant DEGs set, including 1,459 DEGs, 805 upregulated and 654 downregulated. Similarly, group 3 treatment contained the most DEGs (414 DEGs, 311 upregulated and 103 downregulated). KEGG pathway analyses showed five significant pathways associated with the inflammatory and metastasis processes in cancer, which include the TNF, IL−17, NF-kappa B, MAPK signaling pathways, and transcriptional misregulation in cancer. Samples were classified into 13 groups based on their pharmaceutical effects. The results of the KEGG pathway analyses remained consistent with signal samples; group 3 presents a high significance. A total of 21 genes were significantly regulated in these five pathways, interestingly, IL6, TNFAIP3, and BRIC3 were enriched on at least two pathways, seven genes (FOSL1, S100A9, CXCL12, ID2, PRS6KA3, AREG, and DUSP6) have been reported as the target biomarkers and even the diagnostic tools in cancer therapy. In addition, weighted correlation network analysis (WGCNA) was used to identify 18 modules. Among them, blue and thistle2 were the most relevant modules. A total of 26 hub genes in blue and thistle2 modules were identified as the hub genes. In conclusion, we screened out three new TCM (R. communis L., E. cochinchinensis Lour., and B. fruticosa) that have the potential to develop natural drugs for breast cancer therapy, and obtained the therapeutic targets.

Serum Exosomal EphA2 is a Prognostic Biomarker in Patients with Pancreatic Cancer

Background

Pancreatic cancer (PC) is one of the worst prognoses amongst all malignant diseases. It is therefore of great significance to identify biomarkers with predictive clinical value for the prognosis and recurrence of PC.

Methods

In our study, enzyme-linked immunosorbent assays (ELISA) were used to detect the expression of Exo-EphA2 in the serum of PC patients and controls. Kaplan–Meier curve and Cox regression analyses were used to evaluate the prognostic value of Exo-EphA2 expression in patients with primary and recurrent PC.

Results

The level of serum Exo-EphA2 was significantly higher in the PC group when compared to that of the control group. High expression of Exo-EphA2 in PC was associated with shorter overall survival (OS) and proved to be a significant negative prognostic factor in the multivariate analysis (HR = 1.04, 95% CI: 1.00–1.09, P <0.001). Additionally, we found that the level of serum Exo-EphA2 in recurrent PC patients (first recurrence < 12 months) was positively correlated with the level of Exo-EphA2 at primary diagnosis. Multivariate analysis showed that a high expression of Exo-EphA2 in recurrent PC was associated with shorter recurrence-free survival (RFS) (HR = 1.41, 95% CI: 1.10–1.70, P < 0.001).

Conclusion

High expression of serum Exo-EphA2 represents a novel biomarker for a poor prognosis in PC patients.