NRBP1 is downregulated in breast cancer and NRBP1 overexpression inhibits cancer cell proliferation through Wnt/β-catenin signaling pathway

Prostate Cancer: De-regulated Circular RNAs With Efficacy in Preclinical In Vivo Models

Therapy resistance, including castration-resistance and metastasis, remains a major hurdle in the treatment of prostate cancer. In order to identify novel therapeutic targets and treatment modalities for prostate cancer, we conducted a comprehensive literature search on PubMed to identify de-regulated circular RNAs that influence treatment efficacy in preclinical prostate cancer-related in vivo models. Our analysis identified 49 circular RNAs associated with various processes, including treatment resistance, transmembrane and secreted proteins, transcription factors, signaling cascades, human antigen R, nuclear receptor binding, ubiquitination, metabolism, epigenetics and other target categories. The identified targets and circular RNAs can be further scrutinized through target validation approaches. Down-regulated circular RNAs are candidates for reconstitution therapy, while up-regulated RNAs can be inhibited using small interfering RNA (siRNA), antisense oligonucleotides (ASO) or clustered regularly interspaced short palindromic repeats/CRISPR associated (CRISPR-CAS)-related approaches.

The Circular RNA Circ_0085494 Regulates Prostate Cancer Progression Through NRBP1/miR-497-5p Axis

Aberrant expression of circular RNA (circRNA) is closely linked to the progression of various human cancers, including prostate cancer (PCa). In this research, we aimed to investigate the biological role of and mechanisms of circ_0085494 in PCa. The quantitative real-time polymerase chain reaction (qRT-PCR) assay was used to detect circ_0085494, miR-497-5p, and nuclear receptor binding protein 1 (NRBP1) mRNA expression in PCa tissues and cell lines. Subsequently, colony formation, cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and transwell assays were performed to evaluate PCa cell proliferation, migration, and invasion. Western blot assay was applied for assessing the protein levels. Dual-luciferase reporter and RNA pull-down assays were implemented for verifying the association between miR-497-5p and circ_0085494 or NRBP1. The role of circ_0085494 in vivo was measured by establishing a mice xenograft model. Circ_0085494 was highly expressed in PCa tissues and cells, and its absence suppressed PCa cell proliferation, migration, and invasion. Circ_0085494 impacts NRBP1 content by adsorbing miR-497-5p. Meanwhile, the repression of circ_0085494 absence on tumor growth in vivo was validated. Our finding revealed that circ_0085494 downregulation might repress PCa tumor progression through in part regulating the miR-497-5p/NRBP1 pathway.

MFUM-BrTNBC-1, a Newly Established Patient-Derived Triple-Negative Breast Cancer Cell Line: Molecular Characterisation, Genetic Stability, and Comprehensive Comparison with Commercial Breast Cancer Cell Lines

Triple-negative breast cancer (TNBC) is a breast cancer (BC) subtype that accounts for approximately 15–20% of all BC cases. Cancer cell lines (CLs) provide an efficient way to model the disease. We have recently isolated a patient-derived triple-negative BC CL MFUM-BrTNBC-1 and performed a detailed morphological and molecular characterisation and a comprehensive comparison with three commercial BC CLs (MCF-7, MDA-MB-231, MDA-MB-453). Light and fluorescence microscopy were used for morphological studies; immunocytochemical staining for hormone receptor, p53 and Ki67 status; RNA sequencing, qRT-PCR and STR analysis for molecular characterisation; and biomedical image analysis for comparative phenotypical analysis. The patient tissue-derived MFUM-BrTNBC-1 maintained the primary triple-negative receptor status. STR analysis showed a stable and unique STR profile up to the 6th passage. MFUM-BrTNBC-1 expressed EMT transition markers and displayed changes in several cancer-related pathways (MAPK, Wnt and PI3K signalling; nucleotide excision repair; and SWI/SNF chromatin remodelling). Morphologically, MFUM-BrTNBC-1 differed from the commercial TNBC CL MDA-MB-231. The advantages of MFUM-BrTNBC-1 are its isolation from a primary tumour, rather than a metastatic site; good growth characteristics; phenotype identical to primary tissue; complete records of origin; a unique identifier; complete, unique STR profile; quantifiable morphological properties; and genetic stability up to (at least) the 6th passage.

A new risk score based on twelve hepatocellular carcinoma-specific gene expression can predict the patients' prognosis

A large panel of molecular biomarkers have been identified to predict the prognosis of hepatocellular carcinoma (HCC), yet with limited clinical application due to difficult extrapolation. We here generated a genetic risk score system comprised of 12 HCC-specific genes to better predict the prognosis of HCC patients. Four genomics profiling datasets (GSE5851, GSE28691, GSE15765 and GSE14323) were searched to seek HCC-specific genes by comparisons between cancer samples and normal liver tissues and between different subtypes of hepatic neoplasms. Univariate survival analysis screened HCC-specific genes associated with overall survival (OS) in the training dataset for next-step risk model construction. The prognostic value of the constructed HCC risk score system was then validated in the TCGA dataset. Stratified analysis indicated this scoring system showed better performance in elderly male patients with HBV infection and preoperative lower levels of creatinine, alpha-fetoprotein and platelet and higher level of albumin. Functional annotation of this risk model in high-risk patients revealed that pathways associated with cell cycle, cell migration and inflammation were significantly enriched. In summary, our constructed HCC-specific gene risk model demonstrated robustness and potentiality in predicting the prognosis of HCC patients, especially among elderly male patients with HBV infection and relatively better general conditions.

High NRBP1 expression promotes proliferation and correlates with poor prognosis in bladder cancer

Nuclear receptor binding protein 1 (NRBP1) is an evolutionarily highly conserved adaptor protein with multiple domains. Recently, its role in cancers has received increasing attention. To investigate whether NRBP1 is involved in the development of bladder cancer, we used tissue microarray and analyzed the association between the expression levels of NRBP1 and clinico-pathological features of 56 patients diagnosed with bladder cancer. Subsequently, NRBP1 was silenced using siRNA in bladder cancer cell lines T24 and 5637, and cell phenotype such as proliferation and apoptosis were observed. Further, in vivo tumor formation assay was performed. The expression of apoptosis markers was detected by Western blot. A significant positive correlation between increased NRBP1 expression and tumor stage, and lymph node metastasis was observed in 56 patients. High expression of NRBP1 was associated with poor prognosis and NRBP1 knockdown significantly inhibited cell proliferation and induced intrinsic apoptosis in vitro. Moreover, we also found that NRBP1 knockdown significantly suppress tumor growth in xenograft mouse model. Taken together, these data suggest that NRBP1 plays a critical role in the development of bladder cancer and may represent a potential target for bladder cancer treatment.

MicroRNA-216a suppresses the proliferation and migration of human breast cancer cells via the Wnt/β-catenin signaling pathway

The aim of the present study was to investigate the potential anticancer effects of microRNA-216a on the growth of human breast cancer and the possible underlying mechanisms. The results demonstrated that serum microRNA-216a was significantly decreased in patients with breast cancer compared with healthy controls. MicroRNA-216a overexpression led to a decrease in cell proliferation and migration, as well as increases in apoptosis, caspase-3/8 activities, Bax expression and p53 protein expression in MCF-7 cells. It was also revealed that microRNA-216a suppressed Wnt and β-catenin expression in MCF-7 cells. The anticancer effects of microRNA-216a were reversed by anti-microRNA-216a by promoting the Wnt/β-catenin signaling pathway. Inactivation of the Wnt pathway increased the anticancer effects of microRNA-216a in MCF-7 cells. Collectively, the results of the present study indicated that microRNA-216a suppressed the growth of human breast cancer cells by targeting the Wnt/β-catenin signaling pathway.

Detection of epigenetic field defects using a weighted epigenetic distance-based method

Identifying epigenetic field defects, notably early DNA methylation alterations, is important for early cancer detection. Research has suggested these early methylation alterations are infrequent across samples and identifiable as outlier samples. Here we developed a weighted epigenetic distance-based method characterizing (dis)similarity in methylation measures at multiple CpGs in a gene or a genetic region between pairwise samples, with weights to up-weight signal CpGs and down-weight noise CpGs. Using distance-based approaches, weak signals that might be filtered out in a CpG site-level analysis could be accumulated and therefore boost the overall study power. In constructing epigenetic distances, we considered both differential methylation (DM) and differential variability (DV) signals. We demonstrated the superior performance of the proposed weighted epigenetic distance-based method over non-weighted versions and site-level EWAS (epigenome-wide association studies) methods in simulation studies. Application to breast cancer methylation data from Gene Expression Omnibus (GEO) comparing normal-adjacent tissue to tumor of breast cancer patients and normal tissue of independent age-matched cancer-free women identified novel epigenetic field defects that were missed by EWAS methods, when majority were previously reported to be associated with breast cancer and were confirmed the progression to breast cancer. We further replicated some of the identified epigenetic field defects.

Nuclear receptor binding protein 1 correlates with better prognosis and induces caspase-dependent intrinsic apoptosis through the JNK signalling pathway in colorectal cancer

Nuclear receptor binding protein 1 (NRBP1) is a ubiquitously expressed and highly conserved pseudokinase that has important roles in cellular homoeostasis. Despite recent advances in understanding the biology of NRBP1, the role of NRBP1 and its underlying mechanism in colorectal cancer (CRC) have not been fully elucidated. In the present study, we observed that NRBP1 expression levels were significantly reduced in CRC tissues compared with corresponding adjacent normal tissues, and high NRBP1 expression correlated with better prognosis in CRC. Overexpression of NRBP1 inhibited CRC cell proliferation and promoted apoptosis in vitro and in vivo. In contrast, knockdown of NRBP1 expression increased cell proliferation and decreased the percentage of apoptotic cells. Moreover, overexpression of NRBP1 activated caspase-dependent intrinsic apoptosis. In addition, we further discovered that NRBP1 regulated the apoptotic pathway through interaction with JNK. Finally, NRBP1 overexpression led to attenuated CRC growth in a xenograft mouse model. Our study illustrates the suppressor role of NRBP1 in CRC and provides a potential therapeutic target.

Long Noncoding RNA FOXC2-AS1 Predicts Poor Survival in Breast Cancer Patients and Promotes Cell Proliferation

Breast cancer (BC) is the most common malignant tumor in women. Recently, long noncoding RNAs (lncRNAs) have been proposed as critical regulators in biological processes, including tumorigenesis. FOXC2-AS1, a single antisense oligonucleotide RNA transcribed from the negative strand of forkhead box protein C2 (FOXC2), has been identified as an oncogene in osteosarcoma. In the present study, we investigated the prognosis value and biological role of FOXC2-AS1 in BC. Our findings revealed that FOXC2-AS1 was significantly increased in BC tissues and cell lines, and Kaplan–Meier survival analysis indicated that a high level of FOXC2-AS1 was associated with poor prognosis of BC patients. Loss of function revealed that silenced FOXC2-AS1 significantly suppressed the proliferation ability, and flow cytometric analysis illustrated the influence of FOXC2-AS1 on cell cycle and apoptosis rate. Finally, we found that cyclin D1, cyclin D2, and cyclin D3 were all partly positively modulated by FOXC2-AS1 in BC. Collectively, FOXC2-AS1 may serve as a promising prognostic biomarker and therapeutic target for BC patients.

DNA hypomethylation of a transcription factor binding site within the promoter of a gout risk gene NRBP1 upregulates its expression by inhibition of TFAP2A binding

BACKGROUND

Genome-wide association studies (GWASs) have identified dozens of loci associated with gout, but for most cases, the risk genes and the underlying molecular mechanisms contributing to these associations are unknown. This study sought to understand the molecular mechanism of a common genetic variant, rs780093, in the development of gout, both in vitro and in vivo.

RESULTS

Nuclear receptor binding protein 1 (NRBP1), as a gout risk gene, and its regulatory region, 72 bp upstream of the transcription start site, designated as B1, were identified through integrative analyses of genome-wide genotype and DNA methylation data. We observed elevated NRBP1 expression in human peripheral blood mononuclear cells (PBMCs) from gout patients. In vitro luciferase reporter and protein pulldown assay results showed that DNA methylation could increase the binding of the transcription factor TFAP2A to B1, leading to suppressed gene expression. There results were further confirmed by in vivo bisulfite pyrosequencing showing that hypomethylation on B1 is associated with increased NRBP1 expression in gout patients.

CONCLUSIONS

Hypomethylation at the promoter region of NRBP1 reduces the binding of TFAP2A and thus leads to elevated NRBP1 expression, which might contribute to the development of gout.

The secret life of kinases: insights into non-catalytic signalling functions from pseudokinases

Over the past decade, our understanding of the mechanisms by which pseudokinases, which comprise ∼10% of the human and mouse kinomes, mediate signal transduction has advanced rapidly with increasing structural, biochemical, cellular and genetic studies. Pseudokinases are the catalytically defective counterparts of conventional, active protein kinases and have been attributed functions as protein interaction domains acting variously as allosteric modulators of conventional protein kinases and other enzymes, as regulators of protein trafficking or localisation, as hubs to nucleate assembly of signalling complexes, and as transmembrane effectors of such functions. Here, by categorising mammalian pseudokinases based on their known functions, we illustrate the mechanistic diversity among these proteins, which can be viewed as a window into understanding the non-catalytic functions that can be exerted by conventional protein kinases.