Transcription Factor KLF5 Binds a Cyclin E1 Polymorphic Intronic Enhancer to Confer Increased Bladder Cancer Risk

TGF-β-induced acetylation of KLF5 drives TNFAIP2 transcription and EMT in nasopharyngeal carcinoma: Unveiling a novel regulatory mechanism

Epithelial-mesenchymal transition (EMT) is one of the critical mechanisms underlying migration, invasion, and metastasis of nasopharyngeal carcinoma (NPC) cells. The transcription factor KLF5 plays a pivotal role in various cancers, however, its precise functions in NPC remain incompletely understood. This study aims to explore the detailed mechanisms by which TGF-β enhances TNFAIP2 transcription by acetylating KLF5, thereby inducing EMT in NPC. KLF5 was significantly overexpressed in NPC tissues and closely associated with adverse clinicopathological features of the patients. Further studies revealed that TGF-β markedly increased the expression of KLF5 and its acetylated form, Ac-KLF5, in NPC cells, with the acetylation status of KLF5 being crucial for its function. KLF5 induced EMT in NPC cells by directly binding to the TNFAIP2 promoter and promoting its transcription. The pro-migratory and pro-invasive effects of acetylated KLF5 on NPC cells depended on TNFAIP2. Additionally, in vivo experiments confirmed that TGF-β treatment induced tumors in NPC mouse models to exhibit apparent EMT characteristics. These results collectively support the central role of the TGF-β-KLF5-TNFAIP2 axis in EMT of NPC. This study elucidates the specific mechanisms by which TGF-β promotes TNFAIP2 transcription by acetylating KLF5, thereby inducing EMT in NPC. This discovery not only provides new insights into the pathogenesis of NPC but also identifies potential therapeutic targets for NPC treatment.

Abrogation of KLF5 sensitizes BRCA1-proficient pancreatic cancer to PARP inhibition

Poly ADP-ribose polymerase (PARP) inhibitor monotherapies are selectively effective in patients with pancreatic, breast, prostate, and ovarian cancers with BRCA1 mutations. Cancer patients with more frequent wild-type BRCA show poor responses to PARP inhibitors. Moreover, patients who are initially sensitive to these inhibitors eventually respond poorly to drugs. In the present study, we discover that abrogation of Kruppel-like factor 5 (KLF5) significantly inhibits homologous recombination, which is the main mechanism for DNA double-stranded repair. Furthermore, the downregulation of KLF5 expression promotes the DNA damage induced by olaparib and significantly reduces the IC 50 of the RARP inhibitor in pancreatic cancer cells. Overexpression of BRCA1 reverses the above effects caused by silencing of KLF5. Olaparib combined with a KLF5 inhibitor has an enhanced cytotoxic effect. Mechanistically, we identify BRCA1 as a KLF5 target gene. BRCA1 is positively correlated with KLF5 in PDAC tissue. Our results indicate that inhibition of KLF5 may induce BRCAness in a larger pancreatic cancer subset with proficient BRCA. The combination of KLF5 inhibitors and PARP inhibitors provides a novel treatment strategy to enhance the sensitivity of BRCA1-proficient pancreatic cancer to PARP inhibitors.

A Functional Variant Alters the Binding of Bone morphogenetic protein 2 to the Transcription Factor NF-κB to Regulate Bone morphogenetic protein 2 Gene Expression and Chicken Abdominal Fat Deposition

In this study, we employed a dual-luciferase reporter assay and electrophoretic mobility shift analysis (EMSA) in vitro to explore whether a 12-base pair (bp) insertion/deletion (InDel) variant (namely g.14798187_14798188insTCCCTGCCCCCT) within intron 2 of the chicken BMP2 gene, which was significantly associated with chicken abdominal fat weight and abdominal fat percentage, is a functional marker and its potential regulatory mechanism. The reporter analysis demonstrated that the luciferase activity of the deletion allele was extremely significantly higher than that of the insertion allele (p < 0.01). A bioinformatics analysis revealed that compared to the deletion allele, the insertion allele created a transcription factor binding site of nuclear factor-kappa B (NF-κB), which exhibited an inhibitory effect on fat deposition. A dual-luciferase reporter assay demonstrated that the inhibitory effect of NF-κB on the deletion allele was stronger than that on the insertion allele. EMSA indicated that the binding affinity of NF-κB for the insertion allele was stronger than that for the deletion allele. In conclusion, the 12-bp InDel chicken BMP2 gene variant is a functional variant affecting fat deposition in chickens, which may partially regulate BMP2 gene expression by affecting the binding of transcription factor NF-κB to the BMP2 gene.

Computational Assessment of the Expression-modulating Potential for Non-coding Variants

Large-scale genome-wide association studies (GWAS) and expression quantitative trait locus (eQTL) studies have identified multiple non-coding variants associated with genetic diseases by affecting gene expression. However, pinpointing causal variants effectively and efficiently remains a serious challenge. Here, we developed CARMEN, a novel algorithm to identify functional non-coding expression-modulating variants. Multiple evaluations demonstrated CARMEN's superior performance over state-of-the-art tools. Applying CARMEN to GWAS and eQTL datasets further pinpointed several causal variants other than the reported lead single-nucleotide polymorphisms (SNPs). CARMEN scales well with the massive datasets, and is available online as a web server at http://carmen.gao-lab.org.

Diet quality, common genetic polymorphisms, and bladder cancer risk in a New England population-based study

PURPOSE

We examined the interaction between common genetic bladder cancer variants, diet quality, and bladder cancer risk in a population-based case-control study conducted in New England.

METHODS

At the time of enrollment, 806 bladder cancer cases and 974 controls provided a DNA sample and completed a diet history questionnaire. Diet quality was assessed using the 2010 Alternate Healthy Eating Index (AHEI-2010) score. Single nucleotide polymorphisms (SNPs) reported in genome-wide association studies to be associated with bladder cancer risk were combined into a polygenic risk score and also examined individually for interaction with the AHEI-2010. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression.

RESULTS

A 1-standard deviation increase in polygenic risk score was associated with higher bladder cancer risk (OR, 1.34; 95% CI 1.21-1.49). Adherence to the AHEI-2010 was not associated with bladder cancer risk (OR, 0.99; 95% CI 0.98-1.00) and the polygenic risk score did not appear to modify the association between the AHEI-2010 and bladder cancer risk. In single-SNP analyses, rs8102137 (bladder cancer risk allele, C) modified the association between the AHEI-2010 total score and bladder cancer risk, with the strongest evidence for the AHEI-2010 long chain fat guideline (OR for TT, 0.92; 95% CI 0.87-0.98; OR for CT, 1.02; 95% CI 0.96-1.08; OR for CC, 1.03; 95% CI 0.93-1.14; p for interaction, 0.02).

CONCLUSIONS

In conclusion, rs8102137 near the cyclin E1 gene ( CCNE1 ) may be involved in gene-diet interactions for bladder cancer risk.

Systems Drug Design for Muscle Invasive Bladder Cancer and Advanced Bladder Cancer by Genome-Wide Microarray Data and Deep Learning Method with Drug Design Specifications

Bladder cancer is the 10th most common cancer worldwide. Due to the lack of understanding of the oncogenic mechanisms between muscle-invasive bladder cancer (MIBC) and advanced bladder cancer (ABC) and the limitations of current treatments, novel therapeutic approaches are urgently needed. In this study, we utilized the systems biology method via genome-wide microarray data to explore the oncogenic mechanisms of MIBC and ABC to identify their respective drug targets for systems drug discovery. First, we constructed the candidate genome-wide genetic and epigenetic networks (GWGEN) through big data mining. Second, we applied the system identification and system order detection method to delete false positives in candidate GWGENs to obtain the real GWGENs of MIBC and ABC from their genome-wide microarray data. Third, we extracted the core GWGENs from the real GWGENs by selecting the significant proteins, genes and epigenetics via the principal network projection (PNP) method. Finally, we obtained the core signaling pathways from the corresponding core GWGEN through the annotations of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway to investigate the carcinogenic mechanisms of MIBC and ABC. Based on the carcinogenic mechanisms, we selected the significant drug targets NFKB1, LEF1 and MYC for MIBC, and LEF1, MYC, NOTCH1 and FOXO1 for ABC. To design molecular drug combinations for MIBC and ABC, we employed a deep neural network (DNN)-based drug-target interaction (DTI) model with drug specifications. The DNN-based DTI model was trained by drug-target interaction databases to predict the candidate drugs for MIBC and ABC, respectively. Subsequently, the drug design specifications based on regulation ability, sensitivity and toxicity were employed as filter criteria for screening the potential drug combinations of Embelin and Obatoclax for MIBC, and Obatoclax, Entinostat and Imiquimod for ABC from their candidate drugs. In conclusion, we not only investigated the oncogenic mechanisms of MIBC and ABC, but also provided promising therapeutic options for MIBC and ABC, respectively.

Secreted miR-153 Controls Proliferation and Invasion of Higher Gleason Score Prostate Cancer

Prostate cancer (PC) is a male common neoplasm and is the second leading cause of cancer death in American men. PC is traditionally diagnosed by the evaluation of prostate secreted antigen (PSA) in the blood. Due to the high levels of false positives, digital rectal examination and transrectal ultrasound guided biopsy are necessary in uncertain cases with elevated PSA levels. Nevertheless, the high mortality rate suggests that new PC biomarkers are urgently needed to help clinical diagnosis. In a previous study, we have identified a network of genes, altered in high Gleason Score (GS) PC (GS ≥ 7), being regulated by miR-153. Until now, no publication has explained the mechanism of action of miR-153 in PC. By in vitro studies, we found that the overexpression of miR-153 in high GS cell lines is required to control cell proliferation, migration and invasion rates, targeting Kruppel-like factor 5 (KLF5). Moreover, miR-153 could be secreted by exosomes and microvesicles in the microenvironment and, once entered into the surrounding tissue, could influence cellular growth. Being upregulated in high GS human PC, miR-153 could be proposed as a circulating biomarker for PC diagnosis.

The landscape of GWAS validation; systematic review identifying 309 validated non-coding variants across 130 human diseases

Background

The remarkable growth of genome-wide association studies (GWAS) has created a critical need to experimentally validate the disease-associated variants, 90% of which involve non-coding variants.

Methods

To determine how the field is addressing this urgent need, we performed a comprehensive literature review identifying 36,676 articles. These were reduced to 1454 articles through a set of filters using natural language processing and ontology-based text-mining. This was followed by manual curation and cross-referencing against the GWAS catalog, yielding a final set of 286 articles.

Results

We identified 309 experimentally validated non-coding GWAS variants, regulating 252 genes across 130 human disease traits. These variants covered a variety of regulatory mechanisms. Interestingly, 70% (215/309) acted through cis-regulatory elements, with the remaining through promoters (22%, 70/309) or non-coding RNAs (8%, 24/309). Several validation approaches were utilized in these studies, including gene expression (n = 272), transcription factor binding (n = 175), reporter assays (n = 171), in vivo models (n = 104), genome editing (n = 96) and chromatin interaction (n = 33).

Conclusions

This review of the literature is the first to systematically evaluate the status and the landscape of experimentation being used to validate non-coding GWAS-identified variants. Our results clearly underscore the multifaceted approach needed for experimental validation, have practical implications on variant prioritization and considerations of target gene nomination. While the field has a long way to go to validate the thousands of GWAS associations, we show that progress is being made and provide exemplars of validation studies covering a wide variety of mechanisms, target genes, and disease areas.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01216-w.

Expression and Prognosis Value of the KLF Family Members in Colorectal Cancer

Krüppel-like factors (KLFs) are some kind of transcriptional regulator that regulates a broad range of cellular functions and has been linked to the development of certain malignancies. KLF expression patterns and prognostic values in colorectal cancer (CRC) have, however, been investigated rarely. To investigate the differential expression, predictive value, and gene mutations of KLFs in CRC patients, we used various online analytic tools, including ONCOMINE, TCGA, cBioPortal, and the TIMER database. KLF2-6, KLF8-10, KLF12-15, and KLF17 mRNA expression levels were dramatically downregulated in CRC tissues, but KLF1, KLF7, and KLF16 mRNA expression levels were significantly elevated in CRC tissues. According to the findings of Cox regression analysis, upregulation of KLF3, KLF5, and KLF6 and downregulation of KLF15 were linked with a better prognosis in CRC. For functional enrichment, our findings revealed that KLF members are involved in a variety of cancer-related biological processes. In colon cancer and rectal cancer, KLFs were also shown to be associated with a variety of immune cells. The findings of this research reveal that KLF family members' mRNA expression levels are possible prognostic indicators for patients with CRC.

FOXC1 Binds Enhancers and Promotes Cisplatin Resistance in Bladder Cancer

Simple Summary

In bladder cancer, cisplatin remains the front-line therapy, but drug resistance is common. Previously, we showed that cancer cells can spontaneously convert to an aggressive drug-resistant phenotype without mutational events. In the current work, we explored the epigenetic mechanism behind the conversion to the drug-resistant phenotype. We discovered that drug-resistant cells have differentially accessible enhancers, which are bound by FOXC1, a transcription factor that is overexpressed in these cells. Accordingly, FOXC1 knockout significantly attenuates the emergence of the drug-resistant phenotype and reduces cell survival upon cisplatin treatment. These findings suggest that FOXC1 binding at accessible enhancers promotes cisplatin drug resistance in bladder cancer cells. Therefore, FOXC1 targeting may be a new therapeutic avenue to mitigate cisplatin resistance and improve treatment efficacy in bladder cancer.

Abstract

Chemotherapy resistance is traditionally attributed to DNA mutations that confer a survival advantage under drug selection pressure. However, in bladder cancer and other malignancies, we and others have previously reported that cancer cells can convert spontaneously to an aggressive drug-resistant phenotype without prior drug selection or mutational events. In the current work, we explored possible epigenetic mechanisms behind this phenotypic plasticity. Using Hoechst dye exclusion and flow cytometry, we isolated the aggressive drug-resistant cells and analyzed their chromatin accessibility at regulatory elements. Compared to the rest of the cancer cell population, the aggressive drug-resistant cells exhibited enhancer accessibility changes. In particular, we found that differentially accessible enhancers were enriched for the FOXC1 transcription factor motif, and that FOXC1 was the most significantly overexpressed gene in aggressive drug-resistant cells. ChIP-seq analysis revealed that differentially accessible enhancers in aggressive drug-resistant cells had a higher FOXC1 binding, which regulated the expression of adjacent cancer-relevant genes like ABCB1 and ID3. Accordingly, cisplatin treatment of bladder cancer cells led to an increased FOXC1 expression, which mediated cell survival and conversion to a drug-resistant phenotype. Collectively, these findings suggest that FOXC1 contributes to phenotypic plasticity by binding enhancers and promoting a mutation-independent shift towards cisplatin resistance in bladder cancer.

The roles and regulation of the KLF5 transcription factor in cancers

Krüppel‐like factor 5 (KLF5) is a member of the KLF family. Recent studies have suggested that KLF5 regulates the expression of a large number of new target genes and participates in diverse cellular functions, such as stemness, proliferation, apoptosis, autophagy, and migration. In response to multiple signaling pathways, various transcriptional modulation and posttranslational modifications affect the expression level and activity of KLF5. Several transgenic mouse models have revealed the physiological and pathological functions of KLF5 in different cancers. Studies of KLF5 will provide prognostic biomarkers, therapeutic targets, and potential drugs for cancers.

Krüppel-like factor 5 is upregulated and induces cell proliferation in endometrial cancer

Krüppel-like factor 5 (KLF5) is involved in various cellular processes, such as cell proliferation and survival. KLF5 has been implicated in cancer pathology. The aim of the present study was to investigate the expression levels and function of KLF5 in endometrial cancer. A total of 30 patients, including 12 patients with endometrial cancer and 18 with benign gynecological diseases (controls), were enrolled at Tokyo Medical University (Tokyo, Japan) between March 2017 and May 2018. Endometrial cancer and control endometrium tissues were collected, and the expression levels of KLF5 were determined using reverse transcription-quantitative PCR, western blotting and immunohistochemistry. For the functional analyses of KLF5 in endometrial cancer, the present study employed a loss-of-function strategy in the human endometrial cancer cell lines in vitro. Ishikawa and HEC1 cells were transduced with lentiviral constructs expressing shRNAs targeting KLF5. MTT and TUNEL assays were performed in cells after knockdown to analyze the role of KLF5 in cell proliferation and survival. The results revealed that the mRNA and protein expression levels of KLF5 were increased in endometrial cancer tissues. In vitro analyses demonstrated that depletion of KLF5 inhibited cell proliferation and decreased the expression levels of cyclin E1. However, silencing KLF5 did not induce cell death. Overall, these results indicated that KLF5 may be crucial in the tumorigenesis of endometrial cancer and has potential as a therapeutic target.

Polymorphisms of KLF3 gene coding region and identification of their functionality for abdominal fat in chickens

KLF3 is a member of the Kruppel‐like factor (KLF) family of transcription factors, and plays an important role in several biological processes, including adipogenesis, erythropoiesis and B‐cell development. The purposes of this study are to search for polymorphisms of KLF3 coding region and to provide functional evidence for abdominal fat in chickens. A total of 168 SNPs in KLF3 coding region were detected in a unique chicken population, the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF). Of which three single nucleotide polymorphisms (g.3452T > C, g.8663A > G and g.10751G > A) were significantly correlated with abdominal fat weight (AFW) and abdominal fat percentage (AFP) of 329 birds from the 19th generation of NEAUHLF (FDR < 0.05). The reporter gene assay was performed to verify functionality of these three SNPs in both ICP‐1 and DF1 cells. Results showed that the luciferase activity of G allele was significantly higher than that of A allele in g.10751G > A (p < 0.05). However, there were no significant differences between different alleles of others two SNPs in luciferase activity. Overall, KLF3 is an important candidate gene that affects chicken abdominal fat content, and the g.10751G > A is a functional variant that potential would be applied to marker‐assisted selection (MAS) for selective breeding programme.

KLF5-Modulated lncRNA NEAT1 Contributes to Tumorigenesis by Acting as a Scaffold for BRG1 to Silence GADD45A in Gastric Cancer

Long noncoding RNAs (lncRNAs), genomic "dark matter," are deeply involved in diverse biological processes. The lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) is a highly participatory lncRNA; however, its roles in gastric cancer (GC) remain largely unexplored. Here, we demonstrated that the expression of NEAT1 was significantly increased and negatively correlated with prognosis in GC. Subsequent experiments confirmed that KLF5 can induce NEAT1 expression by binding to the NEAT1 promoter region. Further experiments revealed that NEAT1 silencing significantly suppressed cell proliferation both in vitro and in vivo and induced apoptosis. We used mRNA sequencing (mRNA-seq) to identify the preferentially affected genes linked to cell proliferation in cells with NEAT1 knockdown. Mechanistically, NEAT1 bound BRG1 (SMARCA4) directly, modulating H3K27me3 and H3K4me3 in the GADD45A promoter to regulate GADD45A-dependent G2/M cell cycle progression. In addition, BRG1 was significantly upregulated and correlated with outcomes in GC; moreover, it promoted cell proliferation both in vitro and in vivo. Taken together, our data support the importance of NEAT1 in promoting GC tumorigenesis and indicate that NEAT1 might be a diagnostic and therapeutic target in GC.

Network analysis of KLF5 targets showing the potential oncogenic role of SNHG12 in colorectal cancer

BACKGROUND

KLF5 is a member of the Kruppel-like factor, subfamily of zinc finger proteins that are involved in cancers. KLF5 functions as a transcription factor and regulates the diverse protein-coding genes (PCGs) in colorectal cancer (CRC). However, the long non-coding RNAs (lncRNAs) regulated by KLF5 in CRC are currently unknown.

METHODS

In this study, we first designed a computational pipeline to determine the PCG and lncRNA targets of KLF5 in CRC. Then we analyzed the motif pattern of the binding regions for the lncRNA targets. The regulatory co-factors of KLF5 were then searched for through bioinformatics analysis. We also constructed a regulatory network for KLF5 and annotated its functions. Finally, one of the KLF5 lncRNA targets, SNHG12, was selected to further explore its expression pattern and functions in CRC.

RESULTS

We were able to identify 19 lncRNA targets of KLF5 and found that the motifs of the lncRNA binding sites were GC-enriched. Next, we pinpointed the transcription factors AR and HSF1 as the regulatory co-factors of KLF5 through bioinformatics analysis. Then, through the analysis of the regulatory network, we found that KLF5 may be involved in DNA replication, DNA repair, and the cell cycle. Furthermore, in the cell cycle module, the SNHG12 up-regulating expression pattern was verified in the CRC cell lines and tissues, associating it to CRC invasion and distal metastasis. This indicates that SNHG12 may play a critical part in CRC tumorigenesis and progression. Additionally, expression of SNHG12 was found to be down-regulated in CRC cell lines when KLF5 expression was knocked-down by siRNA; and a strong correlation was observed between the expression levels of SNHG12 and KLF5, further alluding to their regulatory relationship.

CONCLUSIONS

In conclusion, the network analysis of KLF5 targets indicates that SNHG12 may be a significant lncRNA in CRC.

Repurposing of KLF5 activates a cell cycle signature during the progression from a precursor state to oesophageal adenocarcinoma

Oesophageal adenocarcinoma (OAC) is one of the most common causes of cancer deaths. Barrett's oesophagus (BO) is the only known precancerous precursor to OAC, but our understanding about the molecular events leading to OAC development is limited. Here, we have integrated gene expression and chromatin accessibility profiles of human biopsies and identified a strong cell cycle gene expression signature in OAC compared to BO. Through analysing associated chromatin accessibility changes, we have implicated the transcription factor KLF5 in the transition from BO to OAC. Importantly, we show that KLF5 expression is unchanged during this transition, but instead, KLF5 is redistributed across chromatin to directly regulate cell cycle genes specifically in OAC cells. This new KLF5 target gene programme has potential prognostic significance as high levels correlate with poorer patient survival. Thus, the repurposing of KLF5 for novel regulatory activity in OAC provides new insights into the mechanisms behind disease progression.

Nurr1 performs its anti-inflammatory function by regulating RasGRP1 expression in neuro-inflammation

Nurr1, a transcription factor belonging to the orphan nuclear receptor, has an essential role in the generation and maintenance of dopaminergic neurons and is important in the pathogenesis of Parkinson’ disease (PD). In addition, Nurr1 has a non-neuronal function, and it is especially well known that Nurr1 has an anti-inflammatory function in the Parkinson’s disease model. However, the molecular mechanisms of Nurr1 have not been elucidated. In this study, we describe a novel mechanism of Nurr1 function. To provide new insights into the molecular mechanisms of Nurr1 in the inflammatory response, we performed Chromatin immunoprecipitation sequencing (ChIP-Seq) on LPS-induced inflammation in BV2 cells and finally identified the RasGRP1 gene as a novel target of Nurr1. Here, we show that Nurr1 directly binds to the RasGRP1 intron to regulate its expression. Moreover, we also identified that RasGRP1 regulates the Ras-Raf-MEK-ERK signaling cascade in LPS-induced inflammation signaling. Finally, we conclude that RasGRP1 is a novel regulator of Nurr1’s mediated inflammation signaling.

ML264 inhibits osteosarcoma growth and metastasis via inhibition of JAK2/STAT3 and WNT/β-catenin signalling pathways

Osteosarcoma, the most common bone malignancy, has a high morbidity rate and poor prognosis. Krüppel‐like factor 5 (KLF5) is a key transcriptional regulator of cellular proliferation whose overexpression is observed in osteosarcoma cell lines (U2OS, 143B, MG63 and SAOS2). ML264, a small‐molecule inhibitor of KLF5, exerts antiproliferative effects in colorectal cancer; however, its function in osteosarcoma remains unknown. Here, we explored the possible antitumour effects of ML264 on 143B and U2OS cell lines and murine tumour xenograft model. ML264 suppressed proliferation and clonogenic ability of osteosarcoma cells in a dose‐dependent manner. Moreover, ML264 induced G0/G1 cell cycle arrest, with no influence on apoptosis, and inhibited the migratory and invasive abilities of osteosarcoma cells, as demonstrated by wound‐healing and Transwell assays. Exposure to ML264 reduced the mRNA and protein levels of molecules associated with epithelial‐mesenchymal transition phenotype, including N‐cadherin, vimentin, Snail, matrix metalloproteinase (MMP) 9 and MMP13. Inhibition of signal transducer and activator of transcription (STAT) 3 phosphorylation and Wnt signalling was also observed. In the murine model of osteosarcoma, tumour growth was efficiently suppressed following a 10‐day treatment with ML264. Collectively, our findings demonstrate the potential value of ML264 as a novel anticancer drug for osteosarcoma.

KLF5 Is Crucial for Androgen-AR Signaling to Transactivate Genes and Promote Cell Proliferation in Prostate Cancer Cells

Androgen/androgen receptor (AR) signaling drives both the normal prostate development and prostatic carcinogenesis, and patients with advanced prostate cancer often develop resistance to androgen deprivation therapy. The transcription factor Krüppel-like factor 5 (KLF5) also regulates both normal and cancerous development of the prostate. In this study, we tested whether and how KLF5 plays a role in the function of AR signaling in prostate cancer cells. We found that KLF5 is upregulated by androgen depending on AR in LNCaP and C4-2B cells. Silencing KLF5, in turn, reduced AR transcriptional activity and inhibited androgen-induced cell proliferation and tumor growth in vitro and in vivo. Mechanistically, KLF5 occupied the promoter of AR, and silencing KLF5 repressed AR transcription. In addition, KLF5 and AR physically interacted with each other to regulate the expression of multiple genes (e.g., MYC, CCND1 and PSA) to promote cell proliferation. These findings indicate that, while transcriptionally upregulated by AR signaling, KLF5 also regulates the expression and transcriptional activity of AR in androgen-sensitive prostate cancer cells. The KLF5-AR interaction could provide a therapeutic opportunity for the treatment of prostate cancer.

The emerging landscape of germline variants in urothelial carcinoma: Implications for genetic testing

Urothelial carcinoma (UC) of the bladder and upper tract (ureter, renal pelvis) is one of the most frequently occurring malignancies. While the majority of UC are chemically induced by smoking, accumulating evidence from genetic studies have demonstrated a small, but consistent impact of heritable gene variants and family history of UC on the development of the disease. Beyond the established association between upper tract UC and germline mismatch DNA repair defects as a defining feature of Lynch syndrome, newer investigations focusing on moderate- and high-risk cancer-related gene variants in DNA damage repair and other signaling pathways are expanding our knowledge on the heritable genetic basis of UC, opening new avenues in the breadth of genetic testing and in clinical counseling of these patients. Overcoming existing challenges in the interpretation of uncertain findings and family cascade testing may help expand our testing approach and guidelines. Following the paradigm of other tumor types, such as breast and ovarian cancers, germline genetic testing, particularly when combined with somatic testing, has the potential to directly benefit affected UC patients and their families in the future through therapeutic targeting (i.e. with poly(ADP-ribose)) polymerase inhibitors, immune checkpoint inhibitors) and genetically informed screening/surveillance, respectively.

Genetic variant of MAML2 in the NOTCH signaling pathway and the risk of bladder cancer: A STROBE-compliant study

The NOTCH signaling pathway plays a crucial role in cell phenotype and transformation. Single nucleotide polymorphisms (SNPs) may regulate gene expression to trigger bladder cancer susceptibility. Here, we aimed to explore the relationships between genetic variants in the NOTCH pathway and bladder cancer progression.We screened SNPs located in NOTCH pathway genes using the 1000 Genomes Project dataset (CHB). A case-control cohort study including 580 bladder cancer cases and 1101 controls was conducted to genotype the candidate SNPs. The expression quantitative trait locus (eQTL) and bioinformatics analyses were performed to explore the biological function of the SNPs' host gene and their relationship. Kaplan-Meier analysis was performed to assess the association between host gene expression and bladder cancer patient prognosis.The rs7944701 in the intron of mastermind-like 2 (MAML2) had the strongest signal and was related to bladder cancer risk (OR = 1.329, 95% CI = 1.115-1.583, P = .001). eQTL analysis showed that rs7944701 with a C allele was negatively associated with mastermind-like 2 (MAML2) expression (TT versus TC/CC). Bioinformatics analysis indicated that MAML2expression was lower in bladder cancer tissues than in non-tumor tissues (P = 5.46 × 10). Additionally, bladder cancer patients with high MAML2 expression had a significantly poorer prognosis (HR = 1.53, 95% CI = 1.29-1.82, P = .010).The rs7944701 in MAML2 was strongly associated with bladder cancer susceptibility in a Chinese population. This genetic variant and its host gene could be a potential novel biomarker for individuals suffering from bladder cancer.

The GALNT14 Genotype Predicts Postoperative Outcome of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDA) is notorious for its poor prognosis. The current mainstay of treatment for PDA is surgical resection followed by adjuvant chemotherapy. However, it is difficult to predict the post-operative outcome because of the lack of reliable markers. The single-nucleotide polymorphism (SNP) of N-acetylgalactosaminyltransferase14 (GALNT14) has been proven to predict the progression-free survival (PFS), overall survival (OS) and response to chemotherapy in various types of gastrointestinal (GI) cancers. However, its role in PDA has not been studied. This study aims to investigate whether the GALNT14 SNP genotype can be a prognostic marker for PDA. A cohort of one hundred and three PDA patients having received surgical resection were retrospectively enrolled. GALNT14 genotypes and the clinicopathological parameters were correlated with postoperative prognosis. The genotype analysis revealed that 19.4%, 60.2% and 20.4% of patients had the GALNT14 "TT", "TG" and "GG" genotypes, respectively. The patients with the "GG" genotype had a mean OS time of 37.1 months (95% confidence interval [CI]: 18.2-56.1) and those with the "non-GG" genotype had a mean OS time of 16.1 months (95% CI: 13.1-19.2). Kaplan-Meier analysis showed that the "GG" genotype had a significantly better OS compared to the "non-GG" genotype (p = 0.005). However, there was no significant difference between the "GG" and "non-GG" genotypes in PFS (p = 0.172). The baseline characteristics between patients with the "GG" and "non-GG" genotypes were compared, and no significant difference was found. Univariate followed by multivariate Cox proportional hazard models demonstrated the GALNT14 "GG" genotype, negative resection margin, and locoregional disease as independent predictors for favorable OS (p = 0.003, p = 0.037, p = 0.021, respectively). Sensitivity analysis was performed in each subgroup to examine the relationship of GALNT14 with different clinicopathological variables and no heterogeneity was found. The GALNT14 "GG" genotype is associated with favorable survival outcome, especially OS, in patients with resected PDA and could serve as a prognostic marker.

Functional Enhancers Shape Extrachromosomal Oncogene Amplifications

Non-coding regions amplified beyond oncogene borders have largely been ignored. Using a computational approach, we find signatures of significant co-amplification of non-coding DNA beyond the boundaries of amplified oncogenes across five cancer types. In glioblastoma, EGFR is preferentially co-amplified with its two endogenous enhancer elements active in the cell type of origin. These regulatory elements, their contacts, and their contribution to cell fitness are preserved on high-level circular extrachromosomal DNA amplifications. Interrogating the locus with a CRISPR interference screening approach reveals a diversity of additional elements that impact cell fitness. The pattern of fitness dependencies mirrors the rearrangement of regulatory elements and accompanying rewiring of the chromatin topology on the extrachromosomal amplicon. Our studies indicate that oncogene amplifications are shaped by regulatory dependencies in the non-coding genome.

Upregulation of NPL4 promotes bladder cancer cell proliferation by inhibiting DXO destabilization of cyclin D1 mRNA

Background

NPL4 is an important cofactor of the valosin-containing protein (VCP)–NPL4–UFD1 complex. The VCP–NPL4–UFD1 has been considered as a ubiquitin proteasome system (UPS) regulator and response to protein degradation. While NPL4 plays important roles in various diseases, little is known about its functions in bladder cancer (BC).

Methods

MTT assays and colony forming test were performed to evaluate cell proliferation ability and Western blotting was used to detect protein expression. Cyclin D1 mRNA expression was detected using qRT-PCR, and coimmunoprecipitation (CoIP) was used to detect protein–protein interactions.

Results

NPL4 was upregulated in BC tissue and correlated with poor prognosis. Upregulation of NPL4 promoted cell proliferation while suppression of NPL4 reduced BC cell proliferation. Upregulation of NPL4 led to overexpression of cyclin D1 by enhancing its mRNA stability. Moreover, NPL4 was found to bind directly to DXO and induce its degradation. DXO was downregulated in BC tissue and regulated BC cell proliferation by destabilizing cyclin D1 mRNA. DXO-mediated NPL4 regulated BC cell proliferation by stabilizing cyclin D1 expression.

Conclusions

The NPL4/DXO/cyclin D1 axis exert crucial role in BC cell growth and is associated with prognosis and may represent a potential therapeutic target for BC.

De novo pattern discovery enables robust assessment of functional consequences of non-coding variants

MOTIVATION

Given the complexity of genome regions, prioritize the functional effects of non-coding variants remains a challenge. Although several frameworks have been proposed for the evaluation of the functionality of non-coding variants, most of them used 'black boxes' methods that simplify the task as the pathogenicity/benign classification problem, which ignores the distinct regulatory mechanisms of variants and leads to less desirable performance. In this study, we developed DVAR, an unsupervised framework that leverage various biochemical and evolutionary evidence to distinguish the gene regulatory categories of variants and assess their comprehensive functional impact simultaneously.

RESULTS

DVAR performed de novo pattern discovery in high-dimensional data and identified five regulatory clusters of non-coding variants. Leveraging the new insights into the multiple functional patterns, it measures both the between-class and the within-class functional implication of the variants to achieve accurate prioritization. Compared to other two-class learning methods, it showed improved performance in identification of clinically significant variants, fine-mapped GWAS variants, eQTLs and expression-modulating variants. Moreover, it has superior performance on disease causal variants verified by genome-editing (like CRISPR-Cas9), which could provide a pre-selection strategy for genome-editing technologies across the whole genome. Finally, evaluated in BioVU and UK Biobank, two large-scale DNA biobanks linked to complete electronic health records, DVAR demonstrated its effectiveness in prioritizing non-coding variants associated with medical phenotypes.

AVAILABILITY AND IMPLEMENTATION

The C++ and Python source codes, the pre-computed DVAR-cluster labels and DVAR-scores across the whole genome are available at https://www.vumc.org/cgg/dvar.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

MicroRNA-493-5p inhibits proliferation and metastasis of osteosarcoma cells by targeting Kruppel-like factor 5

Osteosarcoma, including spinal osteosarcoma, has properties of high degree of malignancy, high rate of recurrence, and high incidence of metastasis. microRNAs can exert oncogenic or tumor suppressive roles in cancer cells. This study explored the effects of microRNA-493-5p (miR-493-5p) on osteosarcoma cell viability, migration, invasion, and apoptosis, as well as the underlying possible mechanism. First, the expression of miR-493-5p in osteosarcoma tissues and cells was detected using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Then, the effects of miR-493-5p overexpression (or suppression) on osteosarcoma cell viability, migration, invasion, and apoptosis, as well as Kruppel-like factor 5 (KLF5) expression, were assessed using the Cell Counting Kit-8 assay, two-chamber transwell assay, Annexin V-FITC/PI apoptosis detection kit, qRT-PCR, and western blotting, respectively. Finally, the roles of KLF5 in miR-493-5p suppression-induced U20S cell viability, migration, and invasion enhancement, as well as the PI3K/AKT pathway activation, were evaluated. We found that miR-493-5p had lower expression in tumor tissues of spinal osteosarcoma and osteosarcoma cells. Overexpression of miR-493-5p inhibited osteosarcoma U20S cell viability, migration, and invasion, but induced cell apoptosis. On the contrary, suppression of miR-493-5p-promoted U20S cell viability, migration, and invasion. KLF5 was a direct target gene of miR-493-5p, which participated in the effects of miR-493-5p on U20S cell viability, migration, invasion, and apoptosis. Furthermore, suppression of the miR-493-5p activated PI3K/AKT pathway in U20S cells by upregulating KLF5. In conclusion, we revealed that miR-493-5p exerted tumor suppressive roles in spinal osteosarcoma and osteosarcoma cells. Overexpression of miR-493-5p inhibited proliferation and metastasis of osteosarcoma cells by downregulating KLF5 and inactivating the PI3K/AKT signaling pathway.

Bladder Cancer Genetic Susceptibility. A Systematic Review

Background:

The variant/gene candidate approach to explore bladder cancer (BC) genetic susceptibility has been applied in many studies with significant findings reported. However, results are not always conclusive due to the lack of replication by subsequent studies.

Objectives:

To identify all epidemiological investigations on the genetic associations with BC risk, to quantify the likely magnitude of the associations by applying metaanalysis methodology and to assess whether there is a potential for publication/reporting bias.

Methods:

To address our aims, we have catalogued all genetic association studies published in the field of BC risk since 2000. Furthermore, we metaanalysed all polymorphisms with data available from at least three independent case-control studies with subjects of Caucasian origin analyzed under the same mode of inheritance.

Results:

The characterization of the genetic susceptibility of BC is composed of 28 variants, GWAS contributing most of them. Most of the significant variants associated with BC risk are located in genes belonging to chemical carcinogenesis, DNA repair, and cell cycle pathways. Causal relationship was also provided by functional analysis for GSTM1-null, NAT2-slow, APOBEC-rs1014971, CCNE1-rs8102137, SLC14A1-rs10775480, PSCA-rs2294008, UGT1A-rs1189203, and TP63-rs35592567.

Conclusions:

Genetic susceptibility of BC is still poorly defined, with GWAS contributing most of the strongest evidence. The systematic review did not provide evidence of further genetic associations. The potential public health translation of the existing knowledge on genetic susceptibility on BC is still limited.