MYBL2 Expression Research Articles

Introduction of MYBL2 as a common regulator between AHR and RELA: Its relationship with lnc-UCC and lnc-HOTTIP in glioblastoma multiforme

This study aimed to validate the experimental gene expression level of a common gene in the Aryl Hydrocarbon Receptor (AHR) and RELA in glioblastoma multiforme (GBM) using bioinformatics.RNAseq data was analyzed to identify differentially expressed genes (DEGs), and LncRNAs related to the regulation of the founded gene were identified by the RNA Interactome Database. Ten healthy controls and 28 GBM patients' tissue samples were gathered, and the change in gene expression levels was measured by real-time PCR.The results showed that MYBL2 is a common regulator between the AHR and RELA, and the expression of MYBL2, lnc-UCC, and lnc-HOTTIP genes was significantly increased in the GBM group.Lnc-UCC expression showed significant positive correlations with MYBL2 and lnc-HOTTIP expression levels. Further investigation into these genes and their regulatory mechanisms is need.

Ectopic MYBL2-Mediated Regulation of Androglobin Gene Expression.

Androglobin (ADGB) is a highly conserved and recently identified member of the globin superfamily. Although previous studies revealed a link to ciliogenesis and an involvement in murine spermatogenesis, its physiological function remains mostly unknown. Apart from FOXJ1-dependent regulation, the transcriptional landscape of the ADGB gene remains unexplored. We, therefore, aimed to obtain further insights into regulatory mechanisms governing ADGB expression. To this end, changes in ADGB promoter activity were examined using luciferase reporter gene assays in the presence of a set of more than 475 different exogenous transcription factors. MYBL2 and PITX2 resulted in the most pronounced increase in ADGB promoter-dependent luciferase activity. Subsequent truncation strategies of the ADGB promoter fragment narrowed down the potential MYBL2 and PITX2 binding sites within the proximal ADGB promoter. Furthermore, MYBL2 binding sites on the ADGB promoter were further validated via a guide RNA-mediated interference strategy using reporter assays. Chromatin immunoprecipitation (ChIP)-qPCR experiments illustrated enrichment of the endogenous ADGB promoter region upon MYBL2 and PITX2 overexpression. Consistently, ectopic MYBL2 expression induced endogenous ADGB mRNA levels. Collectively, our data indicate that ADGB is strongly regulated at the transcriptional level and might have functions beyond ciliogenesis.

The oncogene MYBL2 promotes the malignant phenotype and suppresses apoptosis through hedgehog signaling pathway in clear cell renal cell carcinoma

Multiple cancers have been associated with MYB-related protein B (MYBL2), its involvement in clear cell renal cell carcinoma (ccRCC) has yet to be demonstrated. Our study revealed a significant upregulation of MYBL2 in ccRCC tissues, correlating with clinicopathological features and patient prognosis. Increased MYBL2 expression promoted cell proliferation and suppressed apoptosis. RNA-seq analysis unveiled a reduction in smoothened (SMO) expression upon MYBL2 silencing. However, luciferase and chromatin immunoprecipitation (ChIP) assays demonstrated MYBL2's positive regulation of SMO expression by directly targeting the SMO promoter. Reintroduction of SMO expression in MYBL2-knocked down cells partially restored cell proliferation and mitigated apoptosis inhibition. Overall, these results indicate that MYBL2 facilitates ccRCC progression by enhancing SMO expression, suggesting its potential as an intriguing drug target for ccRCC therapy.

MYBL2 is a Novel Independent Prognostic Biomarker and Correlated with TMB in pancreatic cancer.

Background: Pancreatic cancer continues to pose a significant threat due to its high mortality rate. While MYB family genes have been identified as oncogenes in certain cancer types, their role in pancreatic cancer remains largely unexplored. Methods: The mRNA and protein expression of MYB family genes in pancreatic cancer samples was analyzed using TNMplot, HPA, and TISBID online bioinformatics tools, sourced from the TCGA and GETx databases. The relationship between MYB family gene expression and survival time was assessed through Kaplan-Meier analysis, while the prognostic impact of MYB family gene expression was evaluated using the Cox proportional hazards model. Additionally, Spearman's correlation analysis was employed to investigate the correlation between MYB family genes and TMB/MSI. Results: The integration of data from various databases demonstrated that all MYB family genes exhibited dysregulated expression in pancreatic cancer. However, only the expression of the MYBL2 gene displayed a notable association with the grade and stage of pancreatic cancer. Furthermore, the MYBL2 gene exhibited significant variations in both univariate and multivariate factor analyses.Subsequent functional analyses revealed a significant correlation between MYBL2 expression in pancreatic cancers and various biological processes, such as DNA replication, tumor proliferation, G2M checkpoint regulation, pyrimidine metabolism, and the P53 pathway. Additionally, a notable positive association was observed between MYBL2 expression and tumor mutational burden (TMB), a predictive indicator for response to PD1 antibody treatment. Conclusion: MYBL2 may be a double marker for independent diagnosis and PD1 antibody response prediction of pancreatic cancer patients.

PFDN2 promotes cell cycle progression via the hnRNPD-MYBL2 axis in gastric cancer.

Gastric cancer (GC) is a major health burden worldwide, but our understanding of GC is limited, and the prognosis is poor. Novel therapeutic strategies and biomarkers are urgently needed to improve GC patient outcomes. Previously, we identified PFDN2 as a novel key gene in gastric cancer based on its differential expression between cancer and normal tissues. However, the role and underlying mechanisms of PFDN2 in GC remain elusive. In this article, we demonstrated that PFDN2 is highly expressed in GC and that upregulation of PFDN2 is associated with the progression of GC. We further found that PFDN2 could promote cell cycle progression by promoting MYBL2 expression. Mechanistically, we demonstrated that PFDN2 could upregulate MYBL2 expression by facilitating the nuclear translocation of hnRNPD, and thus promoting MYBL2 transcriptional program. In conclusion, we found that PFDN2 promotes cell cycle progression via the hnRNPD-MYBL2 axis and may serve as a potential biomarker and therapeutic target for GC.

Abstract PD10-06: PD10-06 Clinical outcomes and exploratory gene expression analysis of OPPORTUNE: a phase II window-of-opportunity study to evaluate pictilisib+anastrozole versus anastrozole alone in ER-positive breast cancer

Abstract Background: Endocrine therapy (ET) is the mainstay of ER+ BC treatment. However; up to 20% of ER+ BC tumors progress into metastatic disease and develop ET resistance, underscoring the need for combination therapies. Preclinical data suggest that combining phosphatidylinositol 3-kinase (PI3K) inhibitors with ET may overcome resistance. OPPORTUNE, a preoperative phase II window trial, evaluated whether the combination of the PI3K inhibitor pictilisib with anastrozole (PIC+ANA) can increase the antitumor effect of ANA in newly diagnosed operable ER+ BC. Early results showed greater suppression of tumor Ki67 in patients treated with PIC+ANA versus ANA alone. Here, we present gene expression analysis from tumors collected pre- and post-treatment, and their associations with Ki67 outcomes. Methods: Postmenopausal women with newly diagnosed operable ER+/HER2-negative BC were randomly allocated (2:1, favoring the combination) to 2 weeks of preoperative treatment with ANA 1 mg once per day (n = 47) or the combination of ANA 1 mg with PIC 260 mg once per day (n = 89). The primary end point was inhibition of tumor cell proliferation measured by change in Ki67 protein expression via IHC between tumor samples taken pre- and post-treatment. Samples were analyzed by RNA-sequencing—ER pathway activity, PAM50 intrinsic subtypes, and pathway analyses were assessed by Ki67 outcomes. Elastic net regression analysis and transcription factor activity inference with Dorothea were performed to identify features strongly associated with Ki67 outcomes. Results: 124 patients (ANA, n=43; PIC+ANA, n=81) had paired tumor samples at baseline/week 2 that were evaluable for both Ki67 and RNA-seq. PIC+ANA showed improved suppression of Ki67 compared to ANA alone (-83.78% vs -73.85%, p=0.012) and a greater proportion of patients achieved complete cell cycle arrest (CCCA, as defined by Ki67< 2.7%) in the PIC+ANA arm (45.68% vs 36.59%). ER pathway activity suppression was comparable between treatments. PAM50 classification based on RNA-seq showed that 83.0% of tumors were luminal (Lum) A at baseline and 12.9% were LumB, with the remainder being classified as Normal-like. PIC+ANA showed greater suppression of Ki67 in LumB tumors compared to LumA (-92.29% vs -81.62%). This effect was much greater in the PIC+ANA arm compared to LumB tumors treated with ANA alone (-92.29% vs -37.87%); however, given the low number of LumB tumors in the ANA arm (n=3), we could not determine statistical significance. Bioinformatic analysis of RNA-seq from baseline specimens showed that MYBL2 activity was associated with resistance to ANA (as defined by Ki67≥7.5% at week2). Tumors in the top quartile of MYBL2 activity at baseline showed improved Ki67 outcomes in the PIC+ANA arm compared to ANA alone (-91.71% vs -51.44%), while no differences were observed between treatments for tumors with lower MYBL2 activity (-79.16% vs -76.72%). Single-nucleus (sn)-RNA-seq from untreated ER+ BC tumors showed that MYBL2 was enriched in a single cluster of tumor cells, which also had the highest expression of a subset of actionable targets (including CDK1, CDK2, CDK4, EZH2, and AKT1), as compared to other tumor cells. Expression data from DepMap and drug-sensitivity data from ER+ BC cell lines show a positive trend between high MYBL2 expression and sensitivity to the ER degrader, giredestrant. Conclusions: PIC exhibited greater antiproliferative effects in combination with ANA in ER+/HER2- early BC compared to ANA alone, particularly in LumB and MYBL2-high tumors. Furthermore, the transcriptional profile and in vitro response of tumor cells with high MYBL2 expression suggest potential sensitivity to other combination therapies. Citation Format: Alejandro Martinez Chibly, Alice Shia, Radia Johnson, Michael S. Hwang, Marc Hafner, Ciara Metcalfe, Kalpit Shah, Michal Slyper, Chris Bolen, Sarah E. Pinder, Alastair M. Thompson, Steven Gendreau, Peter Schmid. PD10-06 Clinical outcomes and exploratory gene expression analysis of OPPORTUNE: a phase II window-of-opportunity study to evaluate pictilisib+anastrozole versus anastrozole alone in ER-positive breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD10-06.

Circular RNA circFAT1(e2) Facilitates Cell Progression through the miR-30e-5P/MYBL2 Pathway in Glioma.

To explore the mechanism of glioma from MYB family genes from the perspective of the circRNA-miRNA-mRNA regulatory network. First, the MYB family genes were analyzed by multiple bioinformatics analyses to identify one gene most associated with glioma. Then, the prognostic value and clinical characteristics of the gene were evaluated by bioinformatics analysis and experiments in glioma cells. Next, the target miRNA and circRNA were predicted and verified by dual-luciferase reporter assays. Besides, the functions of target circRNA in glioma were investigated by CCK-8 and Transwell assays. At last, the relation between the screened MYB gene, miRNA, and circRNA in glioma was identified by rescue experiments. After expression and Cox and survival analysis of six MYB family genes, MYBL2 was identified as the gene most associated with glioma. Then, we found that MYBL2 expression in primary gliomas was higher than those in other histologies, and it had variable expression according to clinical features. Furthermore, MYBL2 knockdown in glioma cells impairs cell growth, invasion, and migration in functional studies. Then, miR-30e-5p and circFAT1(e2) were identified as targets of MYBL2 by bioinformatics prediction and experimental verification. Finally, the relationship between circFAT1(e2), MYBL2, and miR-30e-5p was elucidated by rescue experiments. circFAT1(e2) could promote glioma development by regulating MYBL2 and miR-30e-5p, and MYBL2 has diagnostic and prognostic values in glioma.

Increased MYBL2 expression in aggressive hormone-sensitive prostate cancer.

Loss of the histone demethylase KDM5D (lysine-specific demethylase 5D) leads to in vitro resistance of prostate cancer cells to androgen deprivation therapy (ADT) with and without docetaxel. We aimed to define downstream drivers of the KDM5D effect. Using chromatin immunoprecipitation sequencing (ChIP-seq) of the LNCaP cell line (androgen-sensitive human prostate adenocarcinoma) with and without silenced KDM5D, MYBL2-binding sites were analyzed. Associations between MYBL2 mRNA expression and clinical outcomes were assessed in cohorts of men with localized and metastatic hormone-sensitive prostate cancer. In vitro assays with silencing and overexpression of MYBL2 and KDM5D in androgen receptor (AR)-positive hormone-sensitive prostate cancer cell lines, LNCaP and LAPC4, were used to assess their influence on cellular proliferation, apoptosis, and cell cycle distribution, as well as sensitivity to androgen deprivation, docetaxel, and cabazitaxel. We found that silencing KDM5D increased histone H3 lysine K4 (H3K4) trimethylation and increased MYBL2 expression. KDM5D and MYBL2 were negatively correlated with some but not all clinical samples. Higher MYBL2 expression was associated with a higher rate of relapse in localized disease and poorer overall survival in men with metastatic disease in the CHAARTED trial. Lower MYBL2 levels enhanced LNCaP and LAPC4 sensitivity to androgen deprivation and taxanes. In vitro, modifications of KDM5D and MYBL2 altered cell cycle distribution and apoptosis in a cell line-specific manner. These results show that the transcription factor MYBL2 impacts in vitro hormone-sensitive prostate cancer sensitivity to androgen deprivation and taxanes, and lower levels are associated with better clinical outcomes in men with hormone-sensitive prostate cancer.

High expression of MYBL2 promotes progression and predicts a poor survival outcome of prostate cancer

To explore the correlation of MYB proto-oncogene like 2 (MYBL2) with biological behaviors and clinical prognosis of prostate cancer (PCa). We detected Mybl2 mRNA expression in 45 pairs of PCa and adjacent tissues using real-time quantitative PCR, and analyzed the correlation of high (23 cases) and low expression (22 cases) of Mybl2 with clinicopathological features and prognosis of the patients using nonparametric test, Kaplan-Meier survival analysis and univariate and multivariate Cox regression. The results were verified by analysis of the data from Cancer Genome Atlas (TCGA) microarray database, and the molecular pathways were identified by gene set enrichment analysis (GSEA). The CIBERPORT algorithm was used to identify the correlations between Mybl2 expression and tumor microenvironment of PCa. We also tested the effects of MYBL2 knockdown on proliferation and invasion of PCa cell lines using cell counting kit-8 and Transwell assays and observed the growth of PC3 cell xenograft with MYBL2 knockdown in nude mice and the expression levels of Ki-67 in the xenograft using immunohistochemistry. Mybl2 expression was significantly elevated in PCa tissues in close correlation with Gleason score and clinical and pathological stage of the tumor (P < 0.01) but not with the patients' age. Kaplan-Meier analysis indicated a significant negative correlation of high Mybl2 expression with recurrence-free survival (P < 0.05), but not with the overall survival of the patients. The data from TCGA suggested that clinical and pathological stages were independent prognostic factors for recurrence-free survival, and our data indicated that clinical stage and Gleason score were independent prognostic factors of PCa (P < 0.05). GSEA suggested that Mybl2 expression was related with the pathways involving immune function, cell adhesion, and cytokine secretion; CIBERPORT analysis suggested the involvement of Mybl2 expression with memory B cells and resting mast cells (P < 0.05). In LNCaP and PC-3 cells, MYBL2 knockdown significantly inhibited cell proliferation and invasion (P < 0.05); in the tumor-bearing nude mice, the xenografts derived from PC-3 cells with MYBL2 knockdown exhibited a lowered mean tumor weight and positivity rate for Ki67 (P < 0.05). Mybl2 is an oncogene related with multiple pathological indicators of PCa and can serve as a potential prognostic marker as well as a therapeutic target for patients with PCa.

MYBL2 is a Novel Independent Prognostic Biomarker and Correlated with Immune Infiltrates in Prostate Cancer.

PurposeMYB proto-oncogene like 2 (MYBL2) is a member of the MYB family of transcription factor genes and overexpressed in many cancers. We investigated the role of MYBL2 in the malignant progression of prostate cancer (PCa) and its relationship with immune infiltrates in PCa.MethodsGene expression level, clinicopathological parameters, Gene Ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway, tumor immune infiltration analysis were based on The Cancer Genome Atlas (TCGA) dataset. Gene set enrichment analysis (GSEA) and single-sample gene set enrichment analysis (ssGSEA) were conducted to analyze the correlation between MYBL2 and immune infiltrates. The data processing analysis based on R language. The relationship between MYBL2 expression and immune response in PCa was analyzed on TIMER 2.0.ResultsMYBL2 was overexpressed in PCa patients, and correlated with T-stage, Gleason score, primary therapy outcome and progress free interval (PFI) event. The multivariate Cox regression analysis revealed MYBL2 was an independent risk factor for PFI (HR=1.250, 95% CI=1.016–1.537, p=0.035). The receiver operating characteristic (ROC) curve for MYBL2 (AUC=0.887) and nomogram also confirmed the diagnostic value of MYBL2 in the treatment of PCa patients. Based on mRNA expression of MYBL2, PCa patients were divided into MYBL2-high group and MYBL2-low group, and analysis of MYBL2 associated KEGG and GO pathways using R language revealed that 6 immune-related signaling pathways were enriched in MYBL2-high expression phenotype. GSEA analysis showed that 3 hallmark gene sets related to immune response were significantly enriched in MYBL2-high group, ssGSEA analysis found that MYBL2 expression correlated with the expression of many tumor immune lymphocytes (CD8+T cells, neutrophil cells, macrophage cells and so on) and immune check point inhibitors (CD276, BTLA, TNFRSF18, HAVCR2 and CD70).ConclusionMYBL2 is a novel independent prognostic biomarker and MYBL2 may play a crucial role in tumor immune microenvironment of PCa.

Pan-cancer analysis indicates that MYBL2 is associated with the prognosis and immunotherapy of multiple cancers as an oncogene

ABSTRACT MYBL2 has been demonstrated to be an oncogene in some cancers, but there is no pan-cancer analysis at the macro level. We used multiple online or offline bioinformatic tools to examine the effects of MYBL2 in human cancers. We first identified that MYBL2 was highly expressed and related to the stage and grade of most cancers. The results of survival analysis from two databases showed that high MYBL2 expression was positively correlated with a poor prognosis for most cancer patients. We observed a significant difference in the promoter methylation level of MYBL2 in cancers such as colon adenocarcinoma and liver hepatocellular carcinoma versus normal controls. We found that MYBL2 can affect the tumor immune microenvironment by influencing the immune infiltration level and expression level of CD4+ T cells, CD8+ T cells, cancer-associated fibroblasts (CAFs) and immune checkpoint-associated cells. Functional enrichment analysis of MYBL2 identified that MYBL2 can play a crucial role in cancers by regulating spliceosomes, DNA replication and the cell cycle. Moreover, we verified the function of MYBL2 in three cancer cells of glioma, breast cancers and liver cancers, and the results showed that MYBL2 can regulate the cell cycle and proliferation ability of cancers

MYBL1 Knockdown in a Triple Negative Breast Cancer Line: Evidence of Down-Regulation of MYBL2, TCF19 and KIF18b Expression

Purpose: The MYBL1 gene is a strong transcriptional activator, associated with cell cycle signaling and differentiation. Data show the gene is overexpressed in triple negative breast cancers. Considering the possibility that MYBL1 might be involved in events associated with the pathogenesis of these cancers, we sought to identify genes associated with MYBL1 expression in triple negative breast cancer. Methods: shRNA lentiviral knockdown was used to down-regulate the MYBL1 gene. Microarray analyses were used to identify genes either directly or indirectly affected by targeting MYBL1 knockdown. Data analyses was performed utilizing Affymetrix TAC 4.0, Chip X transcription factor analyses, Target Scan miRNA analyses, and STRING analyses was used to determine protein: protein interaction and pathway analyses. Web Gestalt and Gene Ontology were used to determine pathway and gene-set enrichments. Publicly available patient and cell line datasets were retrieved and processed using resources available in Gene Expression Omnibus and Oncomine. The polymerase chain reaction and western analyses were used to determine transcript and protein levels, respectively. Results: Knockdown of MYBL1 in a triple negative breast cell line led to down-regulation of MYBL2, TCF19, KIF18b along with an enrichment of cell cycle signaling genes. Gene expression analyses show that MYBL1, MYBL2, TCF19 and KIF18b display a similar pattern of expression in breast cell lines and many of the archival patient datasets examined. Conclusion: TNBC is a heterogeneous subtype, so these data suggest that cancers that over-express MYBL1, express MYBL2, TCF19 and KIF18b. Bioinformatic analyses suggest MYBL1 regulates MYBL2 which leads to regulation of TCF19 and KIF18b.

LncRNA RPSAP52 induced the development of tongue squamous cell carcinomas via miR-423-5p/MYBL2.

Growing lncRNAs have been noted to involve in the initiation and development of several tumours including tongue squamous cell carcinomas (TSCCs). However, the biological role and mechanism of lncRNA RPSAP52 were not well‐explained. We indicated that RPSAP52 was higher in TSCC samples compared with that in control samples. The higher expression of RPSAP52 was positively correlated with higher T stage and TNM stage. Ectopic expression of RPSAP52 induced TSCC cell growth and cycle and induced cytokine secretion including IFN‐γ, IL‐1β and IL‐6, IL‐8, IL‐10 and TGF‐β. We found that the overexpression of RPSAP52 suppressed miR‐423‐5p expression in SCC‐4 cell. miR‐423‐5p was lower in TSCC samples compared with that in control samples, and miR‐423‐5p level was negatively correlated with higher T stage and TNM stage. Pearson's correlation indicated that miR‐423‐5p was negatively associated with that of RPSAP52 in TSCC tissues. Furthermore, MYBL2 was one direct gene of miR‐423‐5p and elevated expression of miR‐423‐5p suppressed MYBL2 expression and ectopic expression of RPSAP52 increased MYBL2 expression in SCC‐4 cell. Finally, we illustrated that RPSAP52 overexpression promoted TSCC cell growth and cycle and induced cytokine secretion including IFN‐γ, IL‐1β and IL‐6, IL‐8, IL‐10 and TGF‐β via modulating MYBL2. These data provided new insight into RPSAP52, which may be one potential treatment target for TSCC.

PIK3CA Mutation in the ShortHER Randomized Adjuvant Trial for Patients with Early HER2+ Breast Cancer: Association with Prognosis and Integration with PAM50 Subtype.

We explored the prognostic effect of PIK3CA mutation in HER2+ patients enrolled in the ShortHER trial. The ShortHER trial randomized 1,253 patients with HER2+ breast cancer to 9 weeks or 1 year of adjuvant trastuzumab combined with chemotherapy. PIK3CA hotspot mutations in exon 9 and 20 were analyzed by pyrosequencing. Expression of 60 genes, including PAM50 genes was measured using the nCounter platform. A mutation of the PIK3CA gene was detected in 21.7% of the 803 genotyped tumors. At a median follow-up of 7.7 years, 5-year disease-free survival (DFS) rates were 90.6% for PIK3CA mutated and 86.2% for PIK3CA wild-type tumors [HR, 0.84; 95% confidence interval (CI), 0.56-1.27; P = 0.417]. PIK3CA mutation showed a favorable prognostic impact in the PAM50 HER2-enriched subtype (n = 232): 5-year DFS 91.8% versus 76.1% (log-rank P = 0.049; HR, 0.46; 95% CI, 0.21-1.02). HER2-enriched/PIK3CA mutated versus wild-type tumors showed numerically higher tumor-infiltrating lymphocytes (TIL) and significant upregulation of immune-related genes (including CD8A, CD274, PDCD1, and MYBL2, a proliferation gene involved in immune processes). High TILs as well as the upregulation of PDCD1 and MYBL2 were associated with a significant DFS improvement within the HER2-enriched subtype (HR, 0.82; 95% CI, 0.68-0.99; P = 0.039 for 10% TILs increment; HR, 0.81; 95% CI, 0.65-0.99; P = 0.049 for PDCD1 expression; HR, 0.72; 95% CI, 0.53-0.99; P = 0.042 for MYBL2 expression). PIK3CA mutation showed no prognostic impact in the ShortHER trial. Within the HER2-enriched molecular subtype, patients with PIK3CA mutated tumors showed better DFS versus PIK3CA wild-type, which may be partly explained by upregulation of immune-related genes.

The impact of the expression of the transcription factor MYBL2 on outcomes of patients with localized and advanced prostate cancer.

149 Background: Patients with metastatic hormone-sensitive prostate cancer (mHSPC) have a variable response to ADT and some benefit from the addition of docetaxel or an androgen signaling pathway inhibitor. We found that loss of the epigenetic regulator KDM5D is associated with more aggressive prostate cancer (PC). We sought to determine whether MYBL2 which is regulated by KDM5D mediates this effect. MYBL2 is a transcription factor which controls key genes (e.g. FOXM1) and increases cell cycle progression and survival. Methods: AR expressing hormone-sensitive cell lines, LNCaP and LAPC4 were used. Motif analysis and CHiPseq of LNCaP with and without siKDM5D was performed and impact of modulation of KDM5D and MYBL2 in both cells on cell survival was assessed. Gene expression profiling (GEP) data assessed MYBL2’s association with KDM5D levels in localized disease (publicly available data) and mHSPC (Decipher whole Affymetrix platform on CHAARTED samples). Results: Silencing KDM5D increased H3K4me3 and increased MYBL2 expression. GEP showed a strong negative correlation between KDM5D and MYBL2 in patients with localized PC (-0.66; TCGA) but not from primary prostate cancer tissue with mHSPC (-0.03; CHAARTED). Cells with low KDM5D and high MYBL2 were androgen independent and more resistant to docetaxel. In TCGA, patients with high MYBL2 had a higher rate of relapse from localized disease. In patients with metastatic disease (CHAARTED) low MYBL2 was associated with a better overall survival (OS) on multivariable analysis when treated with ADT or ADT + docetaxel. Conclusions: Low MYBL2 is associated with a longer OS with ADT alone and ADT and docetaxel independent of clinical variables. Patients with high MYBL2 expression had better OS with ADT plus docetaxel compared with patients with high MYBL2 treated with ADT alone.[Table: see text]

Circ_0006332 promotes growth and progression of bladder cancer by modulating MYBL2 expression via miR-143.

In this study, we analyzed the role of circular RNAs in the growth and progression of bladder cancer. Direct Sanger sequencing and quantitative RT-PCR analysis showed that circ_0006332 was significantly upregulated in bladder cancer tissues. Sequencing analysis showed that circ_0006332 is generated from splicing of exons 8 and 9 of the MYBL2 transcript. Fluorescence in situ hybridization analysis showed that circ_0006332 was localized to the cytoplasm of bladder cancer cells. Dual luciferase reporter assays showed that miR-143 specifically bound to circ_0006332 and the 3’UTR of MYBL2. High expression of circ_006332 correlated with tumor-node-metastasis stages and muscular invasion in bladder cancer patients. Knockdown of circ_0006332 in bladder cancer cells decreased proliferation, colony formation and invasiveness. Circ_0006332 knockdown increased E-cadherin levels and decreased Vimentin, CCNB1 and P21 protein expression. This suggests that circ_0006332 promotes epithelial–mesenchymal transition and cell cycle progression. In vivo experiments in nude mice showed that circ_0006332 knockdown bladder cancer cells form significantly smaller tumors than the controls. Our study demonstrates that circ_0006332 promotes the growth and progression of bladder cancer by modulating MYBL2 expression by acting as a sponge for miR-143. Circ_0006332 is thus a potential early diagnostic marker of bladder cancer.

Cooperation of cancer drivers with regulatory germline variants shapes clinical outcomes

Pediatric malignancies including Ewing sarcoma (EwS) feature a paucity of somatic alterations except for pathognomonic driver-mutations that cannot explain overt variations in clinical outcome. Here, we demonstrate in EwS how cooperation of dominant oncogenes and regulatory germline variants determine tumor growth, patient survival and drug response. Binding of the oncogenic EWSR1-FLI1 fusion transcription factor to a polymorphic enhancer-like DNA element controls expression of the transcription factor MYBL2 mediating these phenotypes. Whole-genome and RNA sequencing reveals that variability at this locus is inherited via the germline and is associated with variable inter-tumoral MYBL2 expression. High MYBL2 levels sensitize EwS cells for inhibition of its upstream activating kinase CDK2 in vitro and in vivo, suggesting MYBL2 as a putative biomarker for anti-CDK2-therapy. Collectively, we establish cooperation of somatic mutations and regulatory germline variants as a major determinant of tumor progression and highlight the importance of integrating the regulatory genome in precision medicine.

Clinical and biological impact of miR-18a expression in breast cancer after neoadjuvant chemotherapy.

The analysis of breast cancer residual tumors after neoadjuvant chemotherapy (nCT) may be useful for identifying new biomarkers. MicroRNAs are known to be involved in oncogenic pathways and treatment resistance of breast cancer. Our aim was to determine the role of miR-18a, a member of the miR-17-92a cluster, in breast cancer behavior and outcome after nCT. Pre- and post-nCT tumor miR-18a expression was retrospectively assessed by qRT-PCR in 121 patients treated with nCT and was correlated with survival outcomes and with clinical and pathological characteristics. Breast cancer-derived MCF-7 and MDA-MB-231 cell lines were transfected with miR-18a and anti-miR-18a to evaluate the biological effects of this molecule. In addition, whole-transcriptome expression analysis was performed. High miR-18a expression in post-nCT residual tumors was found to be associated with a significantly worse overall survival [hazard ratio (HR): 2.80, 95% confidence interval (CI): 1.01-7.76] and a strong trend towards a poorer disease-free survival (HR: 2.44, 95% CI: 0.99-5.02) compared to low miR-18a expressing post-nCT residual tumors. Clinical and experimental data were found to be in conformity with the proliferative effects of miR-18a, which showed a significant correlation with Ki67 and MYBL2 expression, both in pre- and post-nCT tumors and in public databases. In vitro analysis of the role of miR-18a in breast cancer-derived cell lines showed that a high expression of miR-18a was associated with a low expression of the estrogen receptor (ER), a decreased sensitivity to tamoxifen and an enrichment in luminal B and endocrine resistance gene expression signatures. From our data we conclude that post-nCT miR-18a expression in breast cancer serves as a negative prognostic marker, especially in luminal tumors. Clinical, in vitro and in silico data support the role of miR-18a in breast cancer cell proliferation and endocrine resistance and suggest its potential utility as a biomarker for additional adjuvant treatment in patients without a pathologic complete response to neoadjuvant therapy.

Prognostic implications and oncogenic roles of MYBL2 protein expression in esophageal squamous-cell carcinoma.

BackgroundThe MYBL2 gene, a highly conserved member of the Myb transcription-factor family, has been implicated in the genesis and progression of many types of tumors.MethodsWe analyzed the expression of MYBL2 and Ki67 in tissue samples of esophageal squamous-cell carcinoma (ESCC) patients by immunohistochemistry. We further analyzed the effect of MYBL2 on cell proliferation and DNA replication using a CCK8 assay, 5-ethynyl-2′-deoxyuridine–retention assay, flow-cytometry analysis, real-time quantitative PCR, Western blot, and a xenograft model of ESCC cells in nude mice.ResultsMYBL2 expression was significantly higher in ESCC tissue when compared to the adjacent normal tissue (P=0.007). MYBL2 was found to be positively correlated with Ki67 (γ=0.286, P=0.003). Furthermore, Kaplan–Meier curves indicated that MYBL2 expression in ESCC tissue was associated with poor patient outcome (P<0.001), with MYBL2-positive patients who exhibited high Ki67 expression in ESCC tissue showing the worst prognosis for overall survival (P=0.003). Our in vitro results showed that downregulation of MYBL2 in ESCC cell lines inhibited cell proliferation and DNA replication (P<0.05 for both). We also found that loss of MYBL2 caused a reduction in levels of cell cycle-related G2/M proteins CDK1 and cyclin B1 in ESCC cells. In contrast, overexpression of MYBL2 caused an increase in these proteins. In vivo, we found that in nude mice that received cells knocked down for MYBL2, tumor growth was inhibited in comparison to the group that received control cells (P<0.05).ConclusionMYBL2 overexpression induces tumor proliferation in ESCC cells by regulating cell-cycle at the S and G2/M phase. Therefore, MYBL2 may serve as a novel prognostic biomarker in ESCC patients.

Prognostic implications of MYBL2 in resected Chinese gastric adenocarcinoma patients.

Background and aimGastric cancer (GC), a malignant tumor worldwide, is mostly diagnosed at an advanced stage. We selected the oncogene encoding transcription factors MYBL2 to investigate the connection between MYBL2 expression and GC prognosis.Materials and methodsMYBL2 mRNA and protein expression were measured by real-time PCR and immunohistochemistry, respectively. The relationship between MYBL2 protein expression and survival time was estimated by the Kaplan–Meier analysis. Cox proportional hazards model was used to evaluate the prognostic impact of MYBL2 expression.ResultsThe overexpression of MYBL2 was related to tumor cell differentiation, Lauren type, and metastasis of lymph nodes (P<0.05). In the MYBL2 overexpression group, the median disease free survival was even poorer (P=0.000) and it comes to median overall survival (P=0.000). The study showed that MYBL2 expression was an independent hazard for disease free survival (P=0.004).ConclusionThe results of this study suggest that MYBL2 could indicate a promisingly prognostic biomarker for GC patients.