Lina Gu

Prognostic Significance of MAGE-A11 in Esophageal Squamous Cell Carcinoma and Identification of Related Genes Based on DNA Microarray.

BACKGROUND AND AIMS This study aims to investigate the expression pattern of melanoma-associated antigen-A11 (MAGE-A11) in esophageal squamous cell carcinoma (ESCC) specimens and analyze its prognostic significance for ESCC patients. In addition, the purpose of our study was also to explore the biological function of MAGE-A11 in ESCC cells based on DNA microarray. METHODS Immunohistochemistry was used to detect the expression of MAGE-A11 in ESCC specimens, and its prognostic significance was analyzed by statistical analysis. DNA microarray and quantitative RT-PCR were used to explore the different expression of MAGE-A11 downstream genes in ESCC cells. Cell invasion assay and MTT assay were used to detect the effect of MAGE-A11 cDNA on the invasion and proliferation of ESCC cells. RESULTS Of the ESCC specimens, 59.3% showed positive MAGE-A11 expression. MAGE-A11 expression in ESCC specimens was positively associated with distant lymph node metastasis. Overall survival of ESCC patients with positive MAGE-A11 expression was shorter than in patients with negative MAGE-A11 expression. Multivariate Cox regression analysis showed MAGE-A11 expression is an independent poor prognostic factor for ESCC patients. Overexpression of MAGE-A11 changed a variety of gene expressions, which was associated with various cell functions such as protein ubiquitination, cell proliferation and apoptosis, tumor invasion and metastasis. Overexpression of MAGE-A11 directly increased the invasion and proliferation of ESCC cells. CONCLUSIONS MAGE-A11 is an independent poor prognostic marker for ESCC patients. MAGE-A11 regulates various cell functions and directly increases the invasion and proliferation of ESCC cells.

Aberrant overexpression of EZH2 and H3K27me3 serves as poor prognostic biomarker for esophageal squamous cell carcinoma patients

Abstract It has been reported that the trimethylation of histone 3 on lysine 27 (H3K27me3) is required for enhancer of zeste homology 2 (EZH2)-mediated repression of various genes essential for tumorigenesis and tumor development. Here, we reported the expression of EZH2 and H3K27me3 in esophageal squamous cell carcinoma (ESCC) specimens was higher than the pericarcinoma esophageal specimens. Their expression was positively associated with the poor prognosis of ESCC patients. EZH2 expression, histological grade and distant lymph node metastasis were all independent factors for poor prognosis of ESCC. In addition, enforced expression of EZH2 in esophageal cancer-derived cells could increase the overall H3K27me3 level. Our results suggested the expression of EZH2 and H3K27me3 could serve as biomarkers in the prediction of ESCC patients’ survival and ESCC metastasis.

MAGE-A family expression is correlated with poor survival of patients with lung adenocarcinoma: a retrospective clinical study based on tissue microarray

Objectives As the best characterised cancer/testis antigen family members, melanoma-associated antigens (MAGE) have been reported to be expressed in various malignant tumours. However, the expression pattern of MAGE-A family in lung adenocarcinoma (LAC) specimens and their prognostic and therapeutic significance for patients with LAC is still unclear. Materials and methods Tissue microarray-based immunohistochemistry analysis was used to examine the expression of MAGE-A family members (including MAGE-A1, A2, A3, A4, A6, A10, A11 and A12) in 105 paired LAC specimens and the corresponding pericarcinoma specimens. The association between MAGE-A expression and the clinicopathological parameters, and the 10-year overall survival of patients with LAC were analysed. In addition, the association between MAGE-A expression and the epithelial growth factor receptor (EGFR) amplification and ALK-EML4 rearrangements of patients with LAC were also analysed. Results The immunohistochemical evaluation revealed that MAGE-A family was expressed in 46.66% of LAC specimens, but not in the corresponding pericarcinoma specimens. MAGE-A expression was not associated with the clinicopathological factors but with worse 10-year survival, and was a poor prognostic marker for patients with LAC. MAGE-A expression was not correlated with EGFR amplification and ALK rearrangements. Interestingly, MAGE-A expression can affect the overall survival of patients with LAC without EGFR amplification or ALK rearrangements, but not affect the overall survival of patients with LAC and EGFR amplification or ALK rearrangements. Conclusions Molecular assessment of MAGE-A family members could be considered to improve the prognostic evaluation and to provide a new potential therapeutic strategy for patients with LAC.

Circular RNA ciRS-7 accelerates ESCC progression through acting as a miR-876-5p sponge to enhance MAGE-A family expression

As the most well-known circular RNA, ciRS-7 (also termed CDR1as) has been reported to act as a miR-7 sponge, resulting in reduced miR-7 activity and increased miR-7-targeted transcripts. Here, we showed that ciRS-7 is up-regulated in esophageal squamous cell carcinoma (ESCC), and is associated with the poor clinicopathological parameters of ESCC patients. Moreover, over-expression of ciRS-7 increased the proliferation, migration and invasion of ESCC cells. Mechanistic studies revealed that ciRS-7 contains nineteen miR-876-5p binding sites and acts as a miR-876-5p sponge. Over-expression of ciRS-7 resulted in the reduced tumor-repressive function of miR-876-5p on its downstream target MAGE-A family. In animal experiments, enforced ciRS-7 increased ESCC tumor growth and metastasis through targeting miR-876-5p/MAGE-A family axis. Collectively, our study provided novel evidence that ciRS-7 accelerates ESCC progression by acting as a miR-876-5p sponge to enhance MAGE-A family expression.

MAGE-A11 is activated through TFCP2/ZEB1 binding sites de-methylation as well as histone modification and facilitates ESCC tumor growth

Recently, we have reported that the product of Melanoma Antigens Genes (MAGE) family member MAGE-A11 is an independent poor prognostic marker for esophageal squamous cell carcinoma (ESCC). However, the reason how MAGE-A11 is activated in ESCC progression still remains unclear. In the current study, we demonstrated that DNA methylation and the subsequent histone posttranslational modifications play crucial roles in the regulation of MAGE-A11 in ESCC progression. We found that the methylation rate of TFCP2/ZEB1 binding site on MAGE-A11 promoter in ESCC tissues and cells is higher than the normal esophageal epithelial tissues and cells. Transcription factors TFCP2 and ZEB1 directly bind MAGE-A11 promoter and regulate the endogenous MAGE-A11 expression in a methylation-dependent manner in ESCC cells. Following MAGE-A11 promoter methylation, the methyl-CpG-binding protein MeCP2 was found to bind the methylated MAGE-A11 promoter to mediate histone deactylation by recruiting HDAC1 and HDAC2. Simultaneously, histone inactivation marks including H3K27me3 as well as H3K9me3 were increased, whereas histone activation mark H3K4me3 was decreased. HDAC inhibitor Trichostatin A (TSA) increased DNA methylase inhibitor Decitabine (DAC)-induced MAGE-A11 expression. siRNA-mediated knockdown of histone methltransferase EZH2 or DZNep (a EZH2 inhibitor) treatment increased DAC-induced MAGE-A11 expression. Our results indicate that MAGE-A11 is activated through DNA demethylation, histone acetylation and histone methylation in ESCC, and its activation promotes ESCC tumor growth.

Expression of MAGE-A1, -A9, -A11 in laryngeal squamous cell carcinoma and their prognostic significance: a retrospective clinical study

ABSTRACT Conclusion The melanoma-associated antigens A1, -A9, -A11 (MAGE-A1, -A9, -A11) are relatively tumor-specific in laryngeal squamous cell carcinoma (LSCC), and could be ideal antigens for LSCC immunotherapy. In addition, MAGE-A9 probably is a poor prognostic marker for LSCC patients. Objective The MAGE-A family belongs to Cancer/testis antigens (CTA). However, the expression pattern of MAGE-A1, MAGE-A9, and MAGE-A11 in LSCC is still unclear. This study aims to evaluate the expression and possible prognostic role of MAGE-A1, MAGE-A9, and MAGE-A11 in LSCC patients. Methods The expression of MAGE-A1, MAGE-A9, and MAGE-A11 in LSCC specimens was investigated by immunohistochemistry, and the association of their expression and the clinical parameters and the survival of LSCC patients were analyzed by chi-square test, Kaplan-Meier survival and Cox regression analysis. Results The expression rates of MAGE-A1, MAGE-A9, and MAGE-A11 in LSCC were 54.7%, 46.2%, and 51.9%, respectively. The expression of MAGE-A1, MAGE-A9, and MAGE-A11 in LSCC was correlated with clinical stage, lymph node metastasis, and tumor size. The overall survival of LSCC patients with positive MAGE-A1, MAGE-A9, or MAGE-A11 expression was lower than the patients without MAGE-A1, MAGE-A9, or MAGE-A11 expression. Cox’s multivariable analysis showed that MAGE-A9 expression was an independently poor prognostic factor for LSCC patients.

Zebularine Treatment Induces MAGE-A11 Expression and Improves CTL Cytotoxicity Using a Novel Identified HLA-A2-restricted MAGE-A11 Peptide

Melanoma-associated antigen-A11 (MAGE-A11) is frequently expressed in breast cancer and is associated with poor prognosis. Therefore, MAGE-A11 is a potential immunotherapy target in breast cancer. MAGE-A11 expression, however, is downregulated in many patients, thus constraining the application of immunotherapy. The induction of MAGE-A11 expression is crucial for the recognition and killing of breast cancer cells by cytotoxic T lymphocytes (CTL). In this study, a series of HLA-A2-restricted candidate MAGE-A11 peptides were predicted, synthesized, and tested. Of the selected peptides, p350 (FLFGEPKRL) elicited peptide-specific CTLs from healthy HLA-A*0201-positive donors. The induced CTLs can lyse MAGE-A11-expressing breast cancer cells but not MAGE-A11-negative tumor cells. To improve antitumor immune response, zebularine, a DNA methyltransferase inhibitor, was used to induce MAGE-A11 expression and upregulate the cytotoxicity of antigen-specific T cells in breast cancer cell lines and primary breast cancer cells. The present findings suggested that peptide p350 induces peptide-specific cytolytic activity and is thus a potential candidate for tumor vaccination or T-cell therapy. Epigenetic modulation by zebularine can induce MAGE-A11 expression in breast cancer cells and facilitate cytotoxicity via MAGE-A11-specific CTL.

MAGE-A gene expression in peripheral blood serves as a poor prognostic marker for patients with lung cancer: MAGE-A related lung cancer prognosis

MAGE‐A genes belong to the cancer/testis antigens family. The prognostic significance of MAGE‐A expression in the peripheral blood of patients with lung cancer is unknown. Therefore, this study evaluated the expression and possible prognostic significance of MAGE‐A in the peripheral blood of patients with lung cancer.

miR‑92b promotes autophagy and suppresses viability and invasion in breast cancer by targeting EZH2

MicroRNAs (miRs) are a small non-coding RNA family with a length of 18–22 nucleotides. They are able to regulate gene expression by either triggering target messenger RNA degradation or by inhibiting mRNA translation. Enhancer of zeste homolog 2 (EZH2) is the core enzymatic subunit of polycomb repressor complex 2 and is responsible for the trimethylation of histone 3 on lysine 27 (H3K27me3); it is also able to silence a bundle of tumor suppressor genes through promoter binding. However, little is known regarding the effect of miR-92b on cell autophagy, viability and invasion as well as how it interacts with EZH2. The present study investigated the major role of miR-92b in the autophagy, viability and invasion of breast cancer. It was revealed that in MCF-7 and MDA-MB-453 cells, the expression of miR-92b promoted autophagy induced by starvation and rapamycin treatment. The results of in vitro experiments results demonstrated that miR-92b inhibited breast cancer cell viability, invasion and migration. To further elucidate the regulatory mechanisms of miR-92b in autophagy, a dual luciferase reporter assay was performed to determine whether miR-92b targeted the EZH2 gene. The expression of miR-92b was negatively correlated to EZH2 mRNA expression in breast cancer. Depletion of EZH2 induced phenocopied effects on miR-92b overexpression, thereby demonstrating its importance in autophagy. These results indicated that miR-92b may serve an important role in breast cancer in controlling autophagy, viability and invasion. The present study indicated that miR-92b and EZH2 may serve as potential biomarkers for cancer detection and highlighted their possible therapeutic implications.

Tumor suppressive miR-6775-3p inhibits ESCC progression through forming a positive feedback loop with p53 via MAGE-A family proteins

Accumulating evidences indicate that microRNAs (miRNAs) play vital roles in multiple diseases, including cancer. In the present study, we showed that miR-6775-3p plays a tumor suppressive role in esophageal squamous cell carcinoma (ESCC). High expression miR-6775-3p is associated with good clinical outcomes of ESCC patients. Over-expression of miR-6775-3p inhibited tumor growth and liver metastasis of ESCC xenograft tumors. Enforced expression of miR-6775-3p inhibited ESCC cell proliferation, migration, and invasion. KEGG pathway analysis revealed that miR-6775-3p was associated with the genes on “pathway in cancer”. Mechanically, miR-6775-3p inhibited the expression of tumor antigens MAGE-A family through direct binding the 3′UTR region of MAGE-A mRNAs, and attenuated MAGE-A-inhibited transcriptional activity of tumor suppressor p53. In addition, miR-6775-3p also directly inhibits its host gene SLC7A5 which has been reported to play oncogenic roles in cancer progression. Interestingly, miR-6775-3p and its host gene SLC7A5 were directly transcriptionally induced by p53. Thus, for the first time, our study proposed a novel positive feedback regulation between miR-6775-3p and p53 via MAGE-A family, which plays crucial role in ESCC progression.