Targeted RASSF1A expression inhibits proliferation of HER2­positive breast cancer cells in vitro.

Human epidermal growth factor receptor 2-positive (HER2+) breast cancer, which accounts for 15-20% of all breast cancer, is associated with tumor recurrence and poor prognosis. RAS association domain family protein 1 subtype A (RASSF1A) is a tumor suppressor that is silenced in a variety of human cancers. The present study aimed to investigate the role of RASSF1A in HER2+ breast cancer and the therapeutic potential of RASSF1A-based targeted gene therapy for this malignancy. RASSF1A expression in human HER2+ breast cancer tissues and cell lines was evaluated by reverse transcription PCR and western blot analysis. The associations between tumorous RASSF1A level and tumor grade, TNM stage, tumor size, lymph node metastasis and five-year survival were examined. HER2+ and HER2-negative (HER2-) breast cancer cells were transfected with a lentiviral vector (LV-5HH-RASSF1A) that could express RASSF1A under the control of five copies of the hypoxia-responsive element (5HRE) and one copy of the HER2 promoter (HER2p). Cell proliferation was evaluated by the MTT and colony formation assays. It was found that tumorous RASSF1A level was negatively associated with tumor grade (P=0.014), TNM stage (P=0.0056), tumor size (P=0.014) and lymph node metastasis (P=0.029) and positively associated with five-year survival (P=0.038) in HER2+ breast cancer patients. Lentiviral transfection of HER2+ breast cancer cells resulted in increased RASSF1A expression and decreased cell proliferation, especially under hypoxic conditions. However, lentiviral transfection of HER2-breast cancer cells did not affect RASSF1A expression. In conclusion, these findings verified the clinical significance of RASSF1A as a tumor suppressor in HER2+ breast cancer and supported LV-5HH-RASSF1A as a potential targeted gene therapy for this malignancy.

Diagnostic Significance of 3D Automated Breast Volume Scanner in a Combination with Contrast-Enhanced Ultrasound for Breast Cancer.

The incidence of cancer is increasing today, particularly lung and chest cancer. Employing novel methods to detect cancer in its earliest stages and discover painless, noninvasive treatments are urgently needed. The goal of the proposed study is to investigate the value of automated breast volume scanning (ABUS) in conjunction with contrast-enhanced ultrasonography (CEUS) in properly diagnosing breast cancer in its early stages and the effectiveness of neoadjuvant chemotherapy (NAC) in treating the disease. For the research study, information on 98 patients who had NAC and surgery in the breast surgery department of the Shaanxi Provincial Cancer Hospital has been gathered. All patients have received four cycles of NAC and underwent conventional ultrasound (HUSS), CEUS, ABUS, and pathological examination. At the same time, receiver operating characteristic (ROC) curve analysis, single factor, multiple linear regression, and other methods have also been used to analyze the diagnostic efficacy of breast cancer and NAC efficacy evaluation results. The study of this paper is totally based on the data collected from Shaanxi Provincial Cancer Hospital. The statistical and computational analyses are performed on the data collected for drawing inferences. When the findings are compared to the results of the pathological examination, HUSS has demonstrated a significant distinction between benign and malignant diagnoses with a statistical value of P < 0.05.ABUS combined with CEUS has shown no considerable differences in correlation study. Except for negative likelihood ratio, the diagnostic performance indexes of CEUS+ ABUS are substantially higher than HHUS with P < 0.05. ROC curve analysis is also performed which shows that CEUS and ABUS combination has higher precision in the analysis of breast cancer. ABUS pooled with CEUS shows great application value in the judgment of breast cancer as per the results obtained from the statistical analysis on data of 98 patients.

A Crucial Angiogenesis-Associated Gene MEOX2 Could Be a Promising Biomarker Candidate for Breast Cancer.

Background: Angiogenesis plays a critical role in the growth and metastasis of breast cancer and angiogenesis inhibition has become an effective strategy for cancer therapy. Our study aimed to clarify the key candidate genes and pathways related to breast cancer angiogenesis. Methods: Differentially expressed genes (DEGs) in the raw breast cancer (BRCA) gene dataset from the Cancer Genome Atlas (TCGA) database were identified and gene ontology analysis of the DEGs was performed. Hub genes were subsequently determined using the Gene Expression Omnibus database. The expression of the mesenchyme homeobox 2 (MEOX2) in breast cancer cells and tissues was assessed by quantification real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC), respectively. The prognostic value of the MEOX2 gene in breast cancer tissue was evaluated with the Kaplan-Meier plotter. Results: A total of 61 angiogenesis-related DEGs were identified in the TCGA dataset, among which the gene MEOX2 was significantly down-regulated. GO functional annotation and pathway enrichment analyses showed that MEOX2 was significantly enriched in the regulation of vasculature development. The IHC results confirmed that MEOX2 expression was repressed in breast cancer tissues and the relatively low level indicated the tissue was densely vascularized. Moreover, MEOX2 expression was significantly elevated in breast cancer cells after treatment with cisplatin (DDP) and epirubicin (EPI). Finally, the Kaplan-Meier plotter confirmed that higher expression levels of MEOX2 were related to better overall survival. Conclusion: Our study revealed that the angiogenesis-associated gene MEOX2 can be used as a novel biomarker for breast cancer diagnosis and clinical therapy.

Nucleic Acid Substrate-Independent DNA Polymerization on the Exosome Membrane: A Mechanism Study and Application in Exosome Analysis.

As generally acknowledged, terminal deoxynucleotidyl transferase (TdT) can only elongate DNA substrates from their 3'-OH ends. Herein, for the first time, we report that TdT-catalyzed DNA polymerization can directly proceed on the exosome membrane without the mediation of any nucleic acids. We prove that both the glycosyl and phenolic hydroxyl groups on the membrane proteins can initiate the DNA polymerization. Accordingly, we have developed powerful strategies for high-sensitive exosome profiling based on a conventional flow cytometer and an emerging CRISPR/Cas system. By using our strategy, the featured membrane protein distributions of different cancer cell-derived exosomes can be figured out, which can clearly distinguish plasma samples of breast cancer patients from those of healthy people. This work paves new ways for exosome profiling and liquid biopsy and expands the understanding of TdT, holding great significance in developing TdT-based sensing systems as well as establishing protein/nucleic acid hybrid biomaterials.

Low expression of MEOX2 is associated with poor survival in patients with breast cancer.

Aim: To investigate associations of MEOX2 expression with clinicopathological features and survival of breast cancer patients. Materials & methods: We used a breast cancer tissue microarray for immunohistochemistry. Associations between MEOX2 expression and clinicopathological features were analyzed using the χ-square test. Survival analysis was determined using a Kaplan-Meier curve. Multivariate Cox regression was used to determine associations of MEOX2 expression with overall survival. Results: We found that 74.1% of patients (100/135) had expression of MEOX2 at varying levels. MEOX2 was associated with histological grade and negatively correlated with Ki67 expression. Lower MEOX2 expression was significantly associated with decreased overall survival (p = 0.0011). Conclusion: MEOX2 expression could be a novel diagnostic and prognostic biomarker of breast cancer.

In this study we found that lower expression of the protein MEOX2 was associated with poor overall survival in breast cancer. MEOX2 is an independent prognostic factor for breast cancer patients. It would be a new diagnostic and prognostic biomarker for breast cancer.

Characterization of alternative splicing events and prognostic signatures in breast cancer.

BACKGROUND: Breast cancer (BRCA) is one of the most common cancers worldwide. Abnormal alternative splicing (AS) frequently observed in cancers. This study aims to demonstrate AS events and signatures that might serve as prognostic indicators for BRCA. METHODS: Original data for all seven types of splice events were obtained from TCGA SpliceSeq database. RNA-seq and clinical data of BRCA cohorts were downloaded from TCGA database. Survival-associated AS events in BRCA were analyzed by univariate COX proportional hazards regression model. Prognostic signatures were constructed for prognosis prediction in patients with BRCA based on survival-associated AS events. Pearson correlation analysis was performed to measure the correlation between the expression of splicing factors (SFs) and the percent spliced in (PSI) values of AS events. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were conducted to demonstrate pathways in which survival-associated AS event is enriched. RESULTS: A total of 45,421 AS events in 21,232 genes were identified. Among them, 1121 AS events in 931 genes significantly correlated with survival for BRCA. The established AS prognostic signatures of seven types could accurately predict BRCA prognosis. The comprehensive AS signature could serve as independent prognostic factor for BRCA. A SF-AS regulatory network was therefore established based on the correlation between the expression levels of SFs and PSI values of AS events. CONCLUSIONS: This study revealed survival-associated AS events and signatures that may help predict the survival outcomes of patients with BRCA. Additionally, the constructed SF-AS networks in BRCA can reveal the underlying regulatory mechanisms in BRCA.

Identification of a Novel Cancer Stemness-Associated ceRNA Axis in Lung Adenocarcinoma via Stemness Indices Analysis.

The aim of this study was to identify a novel cancer stemness-related ceRNA regulatory axis in lung adenocarcinoma (LUAD) via weighted gene coexpression network analysis of a stemness index. The RNA sequencing expression profiles of 513 cancer samples and 60 normal samples were obtained from the TCGA database. Differentially expressed mRNAs (DEmRNAs), lncRNAs (DElncRNAs), and miRNAs (DEmiRNAs) were identified with R software. Functional enrichment analysis was conducted using DAVID 6.8. The ceRNA network was constructed via multiple bioinformatics analyses, and the correlations between possible ceRNAs and prognosis were analyzed using KaplanMeier plots. WGCNA was then applied to distinguish key genes related to the mRNA expression-based stemness index (mRNAsi) in LUAD. After combining the weighted gene coexpression and ceRNA networks, a novel ceRNA regulatory axis was identified, and its biological functions were explored in vitro and vivo. In total, 1,825 DElncRNAs, 291 DEmiRNAs, and 3,742 DEmRNAs were identified. Functional enrichment analysis revealed that the DEmRNAs might be associated with LUAD onset and progression. The ceRNA network was constructed with 14 lncRNAs, 10 miRNAs, and 52 mRNAs. KaplanMeier analysis identified 2 DEmiRNAs, 5 DElncRNAs, and 41 DEmRNAs with remarkable prognostic power. One gene (MFAP4) in the ceRNA network was found to be closely related to mRNAsi by using WGCNA. Functional investigation further confirmed that the C8orf34-as1/miR-671-5p/MFAP4 regulatory axis has important functions in LUAD cell migration and stemness. This study provides a deeper understanding of the lncRNAmiRNAmRNA ceRNA network and, more importantly, reveals a novel ceRNA regulatory axis, which may provide new insights into novel molecular therapeutic targets for inhibiting LUAD stem characteristics.

Overexpression of Contactin 1 promotes growth, migration and invasion in Hs578T breast cancer cells.

BACKGROUND: Contactin1 (CNTN1) has been shown to play an important role in the invasion and metastasis of several tumors; however, the role of CNTN1 in breast cancer has not been fully studied. The purpose of this study is to investigate the role of CNTN1 in regulating tumor growth, migration and invasion in breast cancer. RESULTS: To investigate its function, CNTN1 was expressed in Hs578T cells. CNTN1 expression was confirmed by western blot, immunohistochemistry and real-time RT-PCR. The effect of CNTN1 overexpression on proliferation, migration and invasion of Hs578T breast cancer cells was assessed in vitro and in vivo. Our results showed that CNTN1 overexpression promoted Hs578T cell proliferation, cell cycle progression, colony formation, invasion and migration. Notably, overexpression of CNTN1 in Hs578T cells enhanced the growth of mouse xenograft tumors. CONCLUSIONS: CNTN1 promotes growth, metastasis and invasion of Hs578T breast cancer cell line. Thus, therapies targeting CNTN1 may prove efficacious for breast cancer. However, further investigation is required to understand the mechanism by which CNTN1 influences proliferation, metastasis and invasion in breast cancer.

[Upregulation of survivin in non-small cell lung cancer and its clinicopathological correlation with p53 and Bcl-2].

AIM: To retrospectively analyze the clinicopathological data of 87 non-small cell lung cancer (NSCLC) specimens and explore the clinicopathological correlation of survivin with p53 and Bcl-2 and the applicability of combined detection for NSCLC prognosis. METHODS: Survivin, p53 and bcl-2 expression levels were examined in 87 NSCLC specimens using streptavidin-peroxidase (SP) immunohistochemistry. The correlation with NSCLC was analyzed with Spearman rank correlation test. RESULTS: Survivin was positive in 55.2% (48/87) of NSCLC specimens, which was mainly located in cytoplasms and cell-specific. NSCLC at various stages showed significant difference in the positivity of survivin: at stage III and IV (mid and late stage) was 71.1% (32/45) while at stage I and II (early and mid stage) was 38.1% (16/42, P<0.01). Primary tumor with various staging showed no differential expressions of survivin; expression of survivin was significantly correlated with N staging whereby the positivity of specimens without lymph nodal involvement (N0) was 43.5% (27/62) and that for those with lymph nodal involvement (N1-2) was 84.0% (21/25, P<0.01). Survivin was detected in 76.0% (38/50) squamous cell carcinoma and 27.0% (10/37) of adenocarcinoma in a significantly different manner (P<0.01). p53 was positive in 64.6% (56/87) of NSCLC specimens, which was mainly located in cytoplasms and cell-specific. The positivity of specimens with lymph nodal involvement (N1-2) (84.0%, 21/25) was significantly higher than that for those without lymph nodal involvement (N0) (54.8%) (34/62, P<0.01). Moreover, p53 expression was tissue-specific whereby the positivity with squamous cell carcinoma (76.0%, 38/50) was significantly higher than that with adenocarcinoma (27.0%), (10/37, P<0.01). Bcl-2 was positive in 56.3% (49/87) of NSCLC specimens, which was mainly located in cytoplasms and nuclei and cell-specific. The positivity of specimens with lymph nodal involvement (N1-2) (48.0%, 12/25) was significantly higher than that for those without lymph nodal involvement (N0) (22.6%) (14/62, P<0.01). CONCLUSION: Upregulation of survivin represented its clinico-pathological association with NSCLC and meanwhile substantial correlation is confirmed between survivin, p53 and bcl-2.