Identification of TMEM178 as a Potential Prognostic Biomarker and Therapeutic Target for Breast Cancer.

Background: The transmembrane protein (TMEM) family plays important roles in cancer. However, the expression pattern and biological roles of TMEM178, a member of TMEM family, remains unclear in breast cancer (BRCA). Methods: Methylation and RNA-seq data were obtained to explore methylation level. Expression of TMEM178, methylation inhibitor 5-Aza-CdR was used to verify the effect of methylation status on the expression of TMEM178. We comprehensively investigated the prognostic outcomes, biological functions and effects on immune cell infiltration of the TMEM178 in BRCA using multiple bioinformatics methods. Results: The expression of TMEM178 was downregulated and negatively correlated with the level of DNA methylation and DNA methyltransferase (DNMT1, DNMT3A, and DNMT3B) in BRCA. Consistently, TMEM178 mRNA were confirmed to be downregulated, while upregulated in response to treatment with methylation inhibitor 5-Aza-CdR by RT-qPCR. Patients with high expression of TMEM178 have better prognosis and are more sensitive to targeted drug Pazopanib. Immune infiltration analysis showed that the infiltration levels of CD4+ T cell subsets were reduced in BRAC tissues with high TMEM178 expression, and immunosuppressive molecules of T-cell exhaustion were lower expression level. Conclusion: Hypermethylation of the TMEM178 promoter region was a contributing factor to the downregulation of its expression, and TMEM178 may reflect a prognostic and immunosuppressive situation in BRCA.

Exploring the mechanism by which quercetin re-sensitizes breast cancer to paclitaxel: network pharmacology, molecular docking, and experimental verification.

This study is aimed to explore the potential molecular mechanism of quercetin reversing paclitaxel (PTX) resistance in breast cancer (BC) by network pharmacology, molecular docking, and experimental verification. Pharmacological platform databases are used to predict quercetin targets and BC PTX-resistance genes and constructed the expression profile of quercetin chemosensitization. The overlapping targets were input into the STRING database and used Cytoscape v3.9.0 to construct the protein-protein interaction (PPI) network. Subsequently, these targets were performed with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses and molecular docking. Finally, we further detected the potential role of quercetin in improving PTX sensitivity in BC in vitro experiments. Compounds and targets screening hinted that 220 quercetin predicted targets, 244 BC PTX resistance-related genes, and 66 potential sensitive target genes (PSTGs). Network pharmacology screening revealed the top-15 crucial targets in PPI network of quercetin reversing the sensitivity of BC to PTX. KEGG analysis revealed that they were mainly enriched in the EGFR/ERK signaling pathway. Molecular docking showed that both quercetin and PTX could stably bind to the key targets in the EGFR/ERK signaling pathway. In vitro experiments further confirmed that quercetin inhibited the key targets in the EGFR/ERK axis to the suppression of cell proliferation and promotion of apoptosis in PTX-resistance BC cells, and restoring the activity of the resistant cells to PTX. Our results suggested that quercetin increased the sensitivity of BC to PTX through inhibiting EGFR/ERK axis, and it is an effective treatment for reversing PTX resistance.

DNA methylation detection and site analysis by using an electrochemical biosensor constructed based on toehold-mediated strand displacement reaction.

DNA methylation has become a novel target for early diagnosis and prognosis of cancer as well as other related diseases. The accurate detection of the methylation sites of specific genes proved to be of great significance. However, the complex biological nature of clinical samples and the detection of low-abundance targets led to higher requirements for the testing technology. It has been found that by virtue of high sensitivity, rapid response, low cost, facile operation and applicability to microanalysis, electrochemical sensors have greatly contributed to the process of clinical diagnosis. In this study, a facile, rapid and highly sensitive electrochemical biosensor based on the peak current change was developed on the basis of high selectivity of toehold and greater efficiency of PNA strand displacement and used for the detection and site analysis of DNA methylation. Moreover, compared with non-methylated DNA sequences, methylated DNA sequences could be readily invaded by PNA probes, thereby resulting in the strand displacement and significant electrical signals. Therefore, methylation of cytosine sites was primarily analyzed based on electrical signals. Strand displacement by the target DNA sequences with different methylated sites can lead to substantial changes of strand displacement efficiency. As a result, the methylation sites can be analyzed on the basis of corresponding peak current response relation. This method has a detection limit of 0.075 pM and does not involve various complicated steps such as bisulfite treatment, enzyme digestion and PCR amplification. Indeed, one detection cycle can be completed in 60 min. The proposed technology might exhibit great potential in early clinical diagnosis and risk assessment of cancers and related diseases.

Exosomal hsa-miR-21-5p is a biomarker for breast cancer diagnosis.

PURPOSE: Breast cancer (BC) is characterized by concealed onset, delayed diagnosis, and high fatality rates making it particularly dangerous to patients' health. The purpose of this study was to use comprehensive bioinformatics analysis and experimental verification to find a new biomarker for BC diagnosis. METHODS: We comprehensively analyzed microRNA (miRNA) and mRNA expression profiles from the Gene Expression Omnibus (GEO) and screened out differentially-expressed (DE) miRNAs and mRNAs. We used the miRNet website to predict potential DE-miRNA target genes. Using the Database for Annotation, Visualization and Integrated Discovery (DAVID), we performed Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses on overlapping potential target genes and DE-mRNAs. The protein-protein interaction (PPI) network was then established. The miRNA-mRNA regulatory network was constructed using Cytoscape and the analysis results were visualized. We verified the expression of the most up-regulated DE-miRNA using reverse transcription and a quantitative polymerase chain reaction in BC tissue. The diagnostic value of the most up-regulated DE-miRNA was further explored across three levels: plasma-derived exosomes, cells, and cell exosomes. RESULTS: Our comprehensive bioinformatics analysis and experimental results showed that hsa-miR-21-5p was significantly up-regulated in BC tissue, cells, and exosomes. Our results also revealed that tumor-derived hsa-miR-21-5p could be packaged in exosomes and released into peripheral blood. Additionally, when evaluating the diagnostic value of plasma exosomal hsa-miR-21-5p, we found that it was significantly up-regulated in BC patients. Receiver operating characteristic (ROC) analysis also confirmed that hsa-miR-21-5p could effectively distinguish healthy people from BC patients. The sensitivity and specificity were 86.7% and 93.3%, respectively. CONCLUSION: This study's results showed that plasma exosomal hsa-miR-21-5p could be used as a biomarker for BC diagnosis.

Mechanism underlying Polygonum capitatum effect on Helicobacter pylori-associated gastritis based on network pharmacology.

Helicobacter pylori (H. pylori) infection is a common disease that can cause H. pylori-associated gastritis (HAG), peptic ulcers, and gastric cancer. As a traditional Chinese medicine, Polygonum capitatum (PC) manifests its unique advantages in the prevention and treatment of complex diseases and chronic diseases, due to its ability to clear heat, detoxify and relieve pain, promote blood circulation, and remove blood stasis. In order to explore the molecular mechanism of PC for HAG, the study collected the predicted targets of active compounds, conducted functional analysis by the STRING database, collected HAG differential expression genes, and conducted KEGG enrichment analysis on the intersection of predicted targets and differential expression genes of gastritis by Cluego. The results show that PC works mainly by affecting phosphorylation of IκBα, NF-κB p65, p38MAPK, and ERK1/2 and nuclear transposition of NF-κB p65 and p-p38MAPK, which has been proved by in vivo and in vitro experiments. These results suggest that PC may act on HAG with multiple targets and pathways, and play a key role in the process of HAG treatment.

Pan-Cancer Analyses Reveal Oncogenic Role and Prognostic Value of F-Box Only Protein 22.

The F-box protein 22 (FBXO22), an F-box E3 ligase, has been identified to be critically involved in carcinogenesis. However, a systematic assessment of the role of FBXO22 across human cancers is lacking. Here, we performed a pan-cancer analysis to explore the role of FBXO22 in 33 cancer types using multiomic data from The Cancer Genome Atlas (TCGA). First, we found that high FBXO22 expression in multiple cancers was closely associated with poor overall survival and relapse-free survival. Next, we identified ten proteins that interact with FBXO22 and 13 of its target substrates using the STRING database and a literature search to explore the regulatory role of FBXO22 in tumorigenesis. Genes encoding these proteins were found to be significantly enriched in cell cycle negative regulation and ubiquitination pathways. This was confirmed in nonsmall cell lung cancer A549 cells, where FBXO22 overexpression enhanced cyclin-dependent kinase 4 (CDK4) protein levels and promoted cell proliferation. Similarly, overexpression or interference of FBXO22 changed the protein level of one of its substrates, PTEN. Additionally, we found that FBXO22 mutations were accompanied by altered substrate expression, especially in uterine corpus endometrial carcinoma and lung adenocarcinoma; endometrial carcinoma patients with FBXO22 genetic alterations also had better overall and relapse-free survival. Notably, FBXO22 methylation levels were also decreased in most tumors, and hypomethylation of FBXO22 was associated with poor overall survival, relapse-free interval, and progression-free interval in pancreatic adenocarcinoma. Finally, we analyzed the correlation between the abundance of tumor infiltrating lymphocytes (TILs) and FBXO22 expression, copy number variation, and methylation. Multiple algorithms revealed that high FBXO22 expression was associated with lower TIL levels, especially in lung adenocarcinoma, lung squamous cell carcinoma, and sarcoma. Taken together, our findings demonstrate that FBXO22 degrades tumor suppressor genes by ubiquitination and inhibits the cell cycle to promote nonsmall cell lung cancer progression. Our study also provides a relatively comprehensive understanding of the oncogenic role of FBXO22 in different tumors.