Multiplexed promoterless gene expression with CRISPReader.

BACKGROUND: Genes are comprised of DNA codes and contain promoters and other control elements for reading these codes. The rapid development of clustered regularly interspaced short palindromic repeats (CRISPR) technology has made possible the construction of a novel code-reading system with low dependency on the native control elements. RESULTS: We develop CRISPReader, a technology for controlling promoterless gene expression in a robust fashion. We demonstrate that this tool is highly efficient in controlling transcription and translation initiation of a targeted transgene. A notable feature of CRISPReader is the ability to "read" the open reading frames of a cluster of gene without traditional regulatory elements or other cofactors. In particular, we use this strategy to construct an all-in-one AAV-CRISPR-Cas9 system by removing promoter-like elements from the expression cassette to resolve the existing AAV packaging size problem. The compact AAV-CRISPR-Cas9 is also more efficient in transactivation, DNA cleavage, and gene editing than the dual-AAV vector encoding two separate Cas9 elements, shown by targeting both reporter and endogenous genes in vitro and in vivo. CONCLUSIONS: CRISPReader represents a novel approach for gene regulation that enables minimal gene constructs to be expressed and can be used in potential biomedical applications.

LincRNA-p21 suppresses glutamine catabolism and bladder cancer cell growth through inhibiting glutaminase expression.

Long intergenic non-coding RNA p21 (lincRNA-p21) is down-regulated in some solid tumors. Glutamine catabolism plays an important role in cancer development. However, the role of lincRNA-p21 and its association with glutamine catabolism remain unknown in bladder cancer (BC). In the present study, we investigated the involvement of lincRNA-p21 and glutamine catabolism in BC cell growth and found that ectopic linRNA-p21 expression reduced the proliferation and growth of BIU87 and 5637 cells. Opposite results were observed in lincRNA-p21 silenced J82 and T24 cells. The expression of glutaminase (GLS), intracellular level of glutamate and α-Ketoglutarate (α-KG) were negatively regulated by lincRNA-p21. GLS overexpression reversed the suppressive function of lincRNA-p21 on BC cell growth and proliferation. In contrast, GLS reduction by siRNA blunted the viability of lincRNA-p21 lowly expressed BC cells. Furthermore, lincRNA-p21 and GLS abundance dictated the sensitivity of BC cells to bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide (BPTES) treatment. Importantly, reduced lincRNA-p21 expression and increased GLS mRNA level were observed in BC tissues compared with the normal tissues. Our results demonstrate that lincRNA-p21 suppresses the BC cell growth through inhibiting GLS and glutamine catabolism. Targeting this cascade may be a promising treatment strategy for BC patients.

A revolutionary tool: CRISPR technology plays an important role in construction of intelligentized gene circuits.

With the development of synthetic biology, synthetic gene circuits have shown great applied potential in medicine, biology, and as commodity chemicals. An ultimate challenge in the construction of gene circuits is the lack of effective, programmable, secure and sequence-specific gene editing tools. The clustered regularly interspaced short palindromic repeat (CRISPR) system, a CRISPR-associated RNA-guided endonuclease Cas9 (CRISPR-associated protein 9)-targeted genome editing tool, has recently been applied in engineering gene circuits for its unique properties-operability, high efficiency and programmability. The traditional single-targeted therapy cannot effectively distinguish tumour cells from normal cells, and gene therapy for single targets has poor anti-tumour effects, which severely limits the application of gene therapy. Currently, the design of gene circuits using tumour-specific targets based on CRISPR/Cas systems provides a new way for precision cancer therapy. Hence, the application of intelligentized gene circuits based on CRISPR technology effectively guarantees the safety, efficiency and specificity of cancer therapy. Here, we assessed the use of synthetic gene circuits and if the CRISPR system could be used, especially artificial switch-inducible Cas9, to more effectively target and treat tumour cells. Moreover, we also discussed recent advances, prospectives and underlying challenges in CRISPR-based gene circuit development.

OIP5 Promotes Growth, Metastasis and Chemoresistance to Cisplatin in Bladder Cancer Cells.

Opa interacting protein 5 (OIP5) has previously been identified as a tumorigenesis gene. The purpose of this study is to explore the role of OIP5 in the progression of bladder cancer (BC). The OIP5 expression and clinical behaviors in bladder cancer were collected from lager database. Our study showed that OIP5 was highly expressed in bladder cancer tissues and cells. Overexpression of OIP5 in tumor patients predicted worse overall survival (OS) and higher histological grade. Vitro and vivo experiments demonstrated that knockdown of OIP5 significantly inhibited cell growth of BC. Scratch assay and transwell assay suggested that migration capacity of BC cells was decreased after knockdown of OIP5. Cisplatin sensitivity assay indicated that depletion of OIP5 increased the sensitivity of BC cells to cisplatin. Finally, we identified 38 overlapping differentially expressed genes (DEGs) between RNA-seq and TCGA analyses which were closely linked to OIP5. Bioinformatics analysis showed that these DEGs enriched in oocyte meiosis, fanconi anemia pathway, cell cycle, and microRNAs regulation. TOP2A, SPAG5, SKA1, EXO1, TK1 were confirmed to associated with bladder cancer development. Our study suggests that OIP5 may be a potential biomarker for growth, metastasis and drug-resistance in bladder cancer.

Lentivirus-mediated shRNA targeting MUTYH inhibits malignant phenotypes of bladder cancer SW780 cells.

OBJECTIVES: MUTYH is a protein-coding gene that takes part in base excision repair. Many previous studies have reported that MUTYH is directly related to hereditary adenomatous polyposis and colorectal cancer and is also associated with other cancers. However, the relationship between MUTYH and bladder cancer (BC) is unknown. MATERIALS AND METHODS: The expression of MUTYH and clinical characteristics of BC were collected from databases including The Cancer Genome Atlas and Cancer Cell Line Encyclopedia. RNA sequencing and quantitative real-time PCR were used to detect MUTYH expression in SW780 BC cells. The level of MUTYH was stably downregulated by lentivirus-mediated vector in SW780 cells. Cell proliferation was evaluated using Cell Counting Kit-8 assay and 5-ethynyl-20-deoxyuridine assay, migration was detected using scratch assay and Transwell assay, and apoptosis was determined using ELISA. RESULTS: MUTYH was upregulated in BC tissues and SW780 cells and its expression level was positively associated with the stage and grade of carcinomas. MUTYH was successfully downregulated in SW780 cells by transducing with a lentivirus-mediated shRNA targeting MUTYH. MUTYH knockdown inhibited the proliferation and migration and induced apoptosis in SW780 cells. CONCLUSION: Our data suggest that MUTYH is a new participant in bladder urothelial carcinoma. MUTYH may play a role as a biomarker and therapeutic target in BC.

Enhancer RNA - P2RY2e induced by estrogen promotes malignant behaviors of bladder cancer.

Enhancers are transcriptional regulatory elements that increase target gene expression. It has reported that enhancers could universally transcribe into enhancer RNAs (eRNAs) with stimulation. Increasing evidence showed eRNAs participated in various disease processes including malignant tumors. P2RY2 enhancer RNA (P2RY2e) is an estrogen-responsive eRNA and involved in the development of breast cancer. However, the relationship between P2RY2e and bladder cancer (BCa) is unclear. In the study, we discovered that P2RY2e was upregulated in BCa tissues and estrogen-treated cells. Estrogen promoted the malignant abilities of BCa cells. P2RY2e knockdown by CRISPR-Cas13a inhibit the cell multiplication, invasion and migration. Additionally, the cell apoptosis was facilitated. What's more, downregulation of P2RY2e could weaken the cancer-promoting effects of estrogen on BCa. Our study revealed that P2RY2e played a carcinogenic role in BCa and estrogen might promote the initiation of BCa by inducing P2RY2e. We provide a potential therapeutic target for BCa and a new perspective for the tumorigenesis of bladder cancer.

High expression of enhancer RNA MARC1 or its activation by DHT is associated with the malignant behavior in bladder cancer.

Enhancer RNAs (eRNAs), a subclass of noncoding RNA from enhancers, have biological functions in gene expression. However, their potential role in bladder cancer (BCa) remains largely unknown. The present study investigated the functional role of androgen-associated androgen receptor (AR) mediated-eRNA MARC1 (eMARC1) in BCa progression. Cell proliferation, migration, and apoptosis of BCa cell lines (5637 and T24) with different eMARC1 expression levels or treated with 5α-dehydrotestosterone (DHT) were investigated. In the current study, we discovered that eMARC1 was highly expressed in BCa tissues and cell lines, and eMARC1 overexpression promoted the progression of BCa cells, while knockdown of eMARC1 suppressed tumorigenesis. DHT treatment significantly elevated eMARC1 expression levels, which also facilitated cell proliferation, motility, and inhibited cell apoptosis. We further found that eMARC1 silencing impaired the androgenic effect of DHT in BCa cells. These results suggested that eMARC1 exerted its effects on BCa cell progression, and DHT promoted bladder cancer progression by activating eMARC1.

Long non-coding RNA CRNDE in cancer prognosis: Review and meta-analysis.

BACKGROUND: Colorectal neoplasia differentially expressed (CRNDE), a 1910-nt lncRNA encoded on human chromosome 16, has been found to be involved in various cancers. Nevertheless, the clinical and diagnostic values of CRNDE in tumors still need to be explored. In this review, we aimed to elucidate the clinical role of CRNDE in cancer by searching all correlative literature, and we sequentially explored the association between CRNDE levels and overall survival (OS) or clinicopathological characteristics of cancer. METHODS: We conducted a database search of PubMed, Wanfang Data, Ovid, SinoMed, China National Knowledge Infrastructure, Cochrane Library, and Web of Science (up to January 1, 2018). The pooled odds ratio (OR) and hazard ratio (HR) were used to assess extents of correlation between CRNDE and cancer prognosis. After identification of the inclusion and exclusion criteria, 12 articles including 1361 patients were selected for this review. RESULTS: The results suggested that high levels of CRNDE were highly related to poor OS in tumor patients, with pooled HRs of 2.314 (1.894-2.826, P < .001, fixed-effects model). Likewise, we also found that high CRNDE expression was correlated with high tumor stage [OR: 3.340, 95% confidence interval (CI): 2.417-4.616, P < .001, random-effects model] and lymph node metastasis (OR: 3.027, 95% CI: 2.071-4.425, P = .004, random-effects model). CONCLUSIONS: Our findings demonstrated that CRNDE may modify susceptibility for various cancers and may serve as a new predictive factor for prognosis and diagnosis in different types of cancers.

Current Advances on the Important Roles of Enhancer RNAs in Gene Regulation and Cancer.

Revealing the gene regulation networks governing cancer initiation and development is necessary while it remains uncompleted. In recent years, enhancers have been reported to be widely transcribed, resulting in the generation of enhancer RNAs (eRNAs). Previous studies have reported that eRNAs are a subclass of long noncoding RNAs (lncRNAs), which play a critical role in gene regulation and cancer development. These eRNAs can promote enhancer-promoter (E-P) looping formation by binding to other protein factors or propel expression of downstream protein-coding gene. In this review, we have focused on the characteristics of eRNAs and illustrated the biological function and potential mechanism of eRNAs in regulating gene expression and cancer development.

Synthetic artificial "long non-coding RNAs" targeting oncogenic microRNAs and transcriptional factors inhibit malignant phenotypes of bladder cancer cells.

Both oncogenic transcription factors (TFs) and microRNAs (miRNAs) play important roles in human cancers, acting as transcriptional and post-transcriptional regulators, respectively. These phenomena raise questions about the ability of an artificial device to simultaneously regulate miRNAs and TFs. In this study, we aimed to construct artificial long non-coding RNAs, "alncRNAs", and to investigate their therapeutic effects on bladder cancer cell lines. Based on engineering principles of synthetic biology, we combined tandem arrayed aptamer cDNA sequences for TFs with tandem arrayed cDNA copies of binding sites for the miRNAs to construct alncRNAs. In order to prove the utility of this platform, we chose ß-catenin and the miR-183-182-96 cluster as the functional targets and used the bladder cancer cell lines 5637 and SW780 as the test models. Dual-luciferase reporter assay, real-time quantitative PCR (qRT-PCR) and related phenotypic experiments were used to test the expression of related genes and the therapeutic effects of our devices. The result of dual-luciferase reporter assay and qRT-PCR showed that alncRNAs could inhibit transcriptional activity of TFs and expression of corresponding microRNAs. Using functional experiments, we observed decreased cell proliferation, increased apoptosis, and motility inhibition in alncRNA-infected bladder cancer cells. What's more, follow-up mechanism experiments further confirmed the anti-tumor effect of our devices. In summary, our synthetic devices indeed function as anti-tumor regulators, which synchronously accomplish transcriptional and post-transcriptional regulation in bladder cancer cells. Most importantly, anti-cancer effects were induced by the synthetic alncRNAs in the bladder cancer lines. Our devices, all in all, provided a novel strategy and methodology for cancer studies, and might show a great potential for cancer therapy if the challenges of in vivo DNA delivery are overcome.

Prognostic Values of Long Noncoding RNA GAS5 in Various Carcinomas: An Updated Systematic Review and Meta-Analysis.

The growth arrest-specific transcript 5 (GAS5) is a long noncoding RNA with low expression in multiple cancers. This meta-analysis aims to explore the association between GAS5 expression levels and cancer patients' prognosis. We collected all the relevant literatures about GAS5 expression levels associated with overall survival (OS), lymph node metastasis (LNM) and high tumor stage (II/III/IV) (HTS) from the PubMed and Web of Science. The hazard ratio (HR) and the corresponding 95% confidence interval (CI) were calculated to evaluate the link strength between GAS5 and cancer prognosis. A total of 934 patients from 14 studies were included to the present meta-analysis, according to the inclusion and exclusion criteria. The results demonstrated that low expression of GAS5 could predict poor OS in cancer patients (HR = 1.955, 95% CI: 1.551-2.465, P < 0.001). Meanwhile we also analyzed the following cancers independently: hepatocellular carcinoma (HR = 1.893, 95% CI: 1.103-3.249, P = 0.021) and urothelial carcinoma (HR = 1.653, 95% CI: 1.185-2.306, P = 0.003). Compared to the high GAS5 expression group, additionally, patients with low GAS5 expression in tumor tissues were more prone to lymph node metastasis (OR = 0.234, 95%CI: 0.153-0.358, P < 0.001) and high tumor stage (OR = 0.185, 95% CI:0.102-0.333, P < 0.001). In conclusion, this meta-analysis showed that GAS5 might be served as a novel biomarker for predicting prognosis in various types of cancers.

LncRNA MALAT1 Inhibits Apoptosis and Promotes Invasion by Antagonizing miR-125b in Bladder Cancer Cells.

Accumulating evidences suggest that longnon-coding RNAs (lncRNAs) play functional roles in development of different cancers, including cancer initiation and progression. Metastasis associated lung adenocarcinoma transcript 1(MALAT1) is a well-known lncRNA which was previously shown to be a direct target of miR-125b in bladder cancer (BCa) and to promote cancer progression and invasion. However, little is known whether MALAT1 can also target miR-125b. In the present study, using CRISPR-based technologies and qRT-PCR, we show that MALAT1 is capable of suppressing mature miR-125b and increasing the expression of its target genes (Bcl-2 and MMP-13), but has no effect on pri-miR-125b and pre-miR-125b. We observe that the biotin-labeled MALAT1-RNA probe is able to pull down Ago2 and miR-125b and that the negative regulation of miR-125b by MALAT1 is dependent on Ago2. Importantly, the results of flow cytometry assay and transwell assay reveal that the MALAT1-mediated cancer progression is in part due to specific suppression of miR-125b and activation of its two target genes. All together, these data suggest that the "MALAT1-miR-125b-Bcl-2 / MMP-13" axis plays an important role in the progression of BCa, thereby may provide a potential therapeutic strategy for the treatment of human BCa.

Colon cancer associated transcripts in human cancers.

Long non-coding RNAs serve as important regulators in complicated cellular activities, including cell differentiation, proliferation and death. Dysregulation of long non-coding RNAs occurs in the formation and progression of cancers. The family of colon cancer associated transcripts, long non-coding RNAs colon cancer associated transcript-1 and colon cancer associated transcript-2 are known as oncogenes involved in various cancers. Colon cancer associated transcript-1 is a novel lncRNA located in 8q24.2, and colon cancer associated transcript-2 maps to the 8q24.21 region encompassing rs6983267. Colon cancer associated transcripts have close associations with clinical characteristics, such as lymph node metastasis, high TNM stage and short overall survival. Knockdown of them can reverse the malignant phenotypes of cancer cells, including proliferation, migration, invasion and apoptosis. Moreover, they can increase the expression level of c-MYC and oncogenic microRNAs via activating a series of complex mechanisms. In brief, the family of colon cancer associated transcripts may serve as potential biomarkers or therapeutic targets for human cancers.