MEIS2 is essential for neuroblastoma cell survival and proliferation by transcriptional control of M-phase progression

Myeloid ectopic viral integration site 2 accelerates the progression of Alzheimer's disease

Amyloid plaques, a major pathological hallmark of Alzheimer's disease (AD), are caused by an imbalance between the amyloidogenic and non-amyloidogenic pathways of amyloid precursor protein (APP). BACE1 cleavage of APP is the rate-limiting step for amyloid-β production and plaque formation in AD. Although the alteration of BACE1 expression in AD has been investigated, the underlying mechanisms remain unknown. In this study, we determined MEIS2 was notably elevated in AD models and AD patients. Alterations in the expression of MEIS2 can modulate the levels of BACE1. MEIS2 downregulation improved the learning and memory retention of AD mice and decreased the number of amyloid plaques. MEIS2 binds to the BACE1 promoter, positively regulates BACE1 expression, and accelerates APP amyloid degradation in vitro. Therefore, our findings suggest that MEIS2 might be a critical transcription factor in AD, since it regulates BACE1 expression and accelerates BACE1-mediated APP amyloidogenic cleavage. MEIS2 is a promising early intervention target for AD treatment.

Identification of the circRNA-miRNA-mRNA network for treating methamphetamine-induced relapse and behavioral sensitization with cannabidiol

AIMS

This study aims to investigate the pharmacological effects and the underlying mechanism of cannabidiol (CBD) on methamphetamine (METH)-induced relapse and behavioral sensitization in male mice.

METHODS

The conditioned place preference (CPP) test with a biased paradigm and open-field test were used to assess the effects of CBD on METH-induced relapse and behavioral sensitization in male mice. RNA sequencing and bioinformatics analysis was employed to identify differential expressed (DE) circRNAs, miRNAs, and mRNAs in the nucleus accumbens (NAc) of mice, and the interaction among them was predicted using competing endogenous RNAs (ceRNAs) network analysis.

RESULTS

Chronic administration of CBD (40 mg/kg) during the METH withdrawal phase alleviated METH (2 mg/kg)-induced CPP reinstatement and behavioral sensitization in mice, as well as mood and cognitive impairments following behavioral sensitization. Furthermore, 42 DEcircRNAs, 11 DEmiRNAs, and 40 DEmRNAs were identified in the NAc of mice. The circMeis2-miR-183-5p-Kcnj5 network in the NAc of mice is involved in the effects of CBD on METH-induced CPP reinstatement and behavioral sensitization.

CONCLUSIONS

This study constructed the ceRNAs network for the first time, revealing the potential mechanism of CBD in treating METH-induced CPP reinstatement and behavioral sensitization, thus advancing the application of CBD in METH use disorders.

MEIS2 suppresses breast cancer development by downregulating IL10

BACKGROUND

Breast cancer (BC) is the most commonly diagnosed female cancer. Homeobox protein MEIS2, a key transcription factor, is involved in the regulation of many developmental and cellular processes. However, the role of MEIS2 in the development of breast cancer is still unclear.

AIMS

We aimed to examine the role of myeloid ecotropic insertion site (MEIS2) in breast cancer and the association of MEIS2 with breast cancer clinical stages and pathological grades. We revealed the underlying mechanism by which MEIS2 affected breast cancer cell growth and tumor development.

METHODS AND RESULTS

Using human BC cell lines, clinical samples and animal xenograft model, we reveal that MEIS2 functions as a tumor suppressor in breast cancer. The expression of MEIS2 is inversely correlated with BC clinical stages and pathological grades. MEIS2 knockdown (MEIS2-KD) promotes while MEIS2 overexpression suppresses breast cancer cell proliferation and tumor development in vitro and in animal xenograft models, respectively. To determine the biological function of MEIS2, we screen the expression of a group of MEIS2 potential targeting genes in stable-established cell lines. Results show that the knockdown of MEIS2 in breast cancer cells up-regulates the IL10 expression, but MEIS2 overexpression opposed the effect on IL10 expression. Furthermore, the suppressive role of MEIS2 in breast cancer cell proliferation is associated with the IL10 expression and myeloid cells infiltration.

CONCLUSION

Our study demonstrates that the tumor suppressor of MEIS2 in breast cancer progression is partially via down regulating the expression of IL10 and promoting myeloid cells infiltration. Targeting MEIS2 would be a potentially therapeutic avenue for BC.

The impact of MEIS1 TALE homeodomain transcription factor knockdown on glioma stem cell growth

Myeloid ecotropic virus insertion site 1 (MEIS1) is a HOX co-factor necessary for organ development and normal hematopoiesis. Recently, MEIS1 has been linked to the development and progression of various cancers. However, its role in gliomagenesis particularly on glioma stem cells (GSCs) remains unclear. Here, we demonstrate that MEIS1 is highly upregulated in GSCs compared to normal, and glioma cells and to its differentiated counterparts. Inhibition of MEIS1 expression by shRNA significantly reduced GSC growth in both in vitro and in vivo experiments. On the other hand, integrated transcriptomics analyses of glioma datasets revealed that MEIS1 expression is correlated to cell cycle-related genes. Clinical data analysis revealed that MEIS1 expression is elevated in high-grade gliomas, and patients with high MEIS1 levels have poorer overall survival outcomes. The findings suggest that MEIS1 is a prognostic biomarker for glioma patients and a possible target for developing novel therapeutic strategies against GBM.

Cellular Ligand-Receptor Perturbations Unravel MEIS2 as a Key Factor for the Aggressive Progression and Prognosis in Stage II/III Colorectal Cancer

Approximately 10-15% of stage II and 25-30% of stage III colorectal cancer (CRC) patients experience recurrence within 5 years after surgery, and existing taxonomies are insufficient to meet the needs of clinical precision treatment. Thus, robust biomarkers and precise management were urgently required to stratify stage II and III CRC and identify potential patients who will benefit from postoperative adjuvant therapy. Alongside, interactions of ligand-receptor pairs point to an emerging direction in tumor signaling with far-reaching implications for CRC, while their impact on tumor subtyping has not been elucidated. Herein, based on multiple large-sample multicenter cohorts and perturbations of the ligand-receptor interaction network, four well-characterized ligand-receptor-driven subtypes (LRDS) were established and further validated. These molecular taxonomies perform with unique heterogeneity in terms of molecular characteristics, immune and mutational landscapes, and clinical features. Specifically, MEIS2, a key LRDS4 factor, performs significant associations with proliferation, invasion, migration, and dismal prognosis of stage II/III CRC, revealing promising directions for prognostic assessment and individualized treatment of CRC patients. Overall, our study sheds novel insights into the implications of intercellular communication on stage II/III CRC from a ligand-receptor interactome perspective and revealed MEIS2 as a key factor in the aggressive progression and prognosis for stage II/III CRC.

ERN1 knockdown modifies the hypoxic regulation of homeobox gene expression in U87MG glioblastoma cells

OBJECTIVE.

Homeobox genes play an important role in health and disease including oncogenesis. The present investigation aimed to study ERN1-dependent hypoxic regulation of the expression of genes encoding homeobox proteins MEIS (zinc finger E-box binding homeobox 2) and LIM homeobox 1 family, SPAG4 (sperm associated antigen 4) and NKX3-1 (NK3 homeobox 1) in U87MG glioblastoma cells in response to inhibition of ERN1 (endoplasmic reticulum to nucleus signaling 1) for evaluation of their possible significance in the control of glioblastoma growth.

METHODS.

The expression level of homeobox genes was studied in control (transfected by vector) and ERN1 knockdown U87MG glioblastoma cells under hypoxia induced by dimethyloxalylglycine (0.5 mM for 4 h) by quantitative polymerase chain reaction and normalized to ACTB.

RESULTS.

It was found that hypoxia down-regulated the expression level of LHX2, LHX6, MEIS2, and NKX3-1 genes but up-regulated the expression level of MEIS1, LHX1, MEIS3, and SPAG4 genes in control glioblastoma cells. At the same time, ERN1 knockdown of glioblastoma cells significantly modified the sensitivity of all studied genes to a hypoxic condition. Thus, ERN1 knockdown of glioblastoma cells removed the effect of hypoxia on the expression of MEIS1 and LHX1 genes, but increased the sensitivity of MEIS2, LHX2, and LHX6 genes to hypoxia. However, the expression of MEIS3, NKX3-1, and SPAG4 genes had decreased sensitivity to hypoxia in ERN1 knockdown glioblastoma cells. Moreover, more pronounced changes under the conditions of ERN1 inhibition were detected for the pro-oncogenic gene SPAG4.

CONCLUSION.

The results of the present study demonstrate that hypoxia affected the expression of homeobox genes MEIS1, MEIS2, MEIS3, LHX1, LHX2, LHX6, SPAG4, and NKX3-1 in U87MG glioblastoma cells in gene-specific manner and that the sensitivity of all studied genes to hypoxia condition is mediated by ERN1, the major pathway of the endoplasmic reticulum stress signaling, and possibly contributed to the control of glioblastoma growth. A fundamentally new results of this work is the establishment of the fact regarding the dependence of hypoxic regulation of SPAG4 gene expression on ER stress, in particular ERN1, which is associated with suppression of cell proliferation and tumor growth.

Molecular characteristics, clinical significance, and immune landscape of extracellular matrix remodeling-associated genes in colorectal cancer

Background

Extracellular matrix (ECM) remodeling is one of the hallmark events in cancer and has been shown to be closely related to tumor immunity. Immunotherapy has evolved as an important tool to treat various cancers and improve patient prognosis. The positive response to immunotherapy relies on the unique interaction between cancer and the tumor microenvironment (TME). However, the relationship between ECM remodeling and clinical outcomes, immune cell infiltration, and immunotherapy in colorectal cancer (CRC) remains unknown.

Methods

We systematically evaluated 69 ECM remodeling-associated genes (EAGs) and comprehensively identified interactions between ECM remodeling and prognosis and the immune microenvironment in CRC patients. The EAG_score was used to quantify the subtype of ECM remodeling in patients. We then assessed their value in predicting prognosis and responding to treatment in CRC.

Results

After elaborating the molecular characteristics of ECM remodeling-related genes in CRC patients, a model consisting of two ECM remodeling-related genes (MEIS2, SLC2A3) was developed for predicting the prognosis of CRC patients, Receiver Operating Characteristic (ROC) and Kaplan-Meier (K-M) analysis verified its reliable predictive ability. Furthermore, we created a highly reliable nomogram to enhance the clinical feasibility of the EAG_score. Significantly differences in TME and immune function, such as macrophages and CD8+ T cells, were observed between high- and low-risk CRC patients. In addition, drug sensitivity is also strongly related to EAG_score.

Conclusion

Overall, we developed a prognostic model associated with ECM remodeling, provided meaningful clinical implications for immunotherapy, and facilitated individualized treatment for CRC patients. Further studies are needed to reveal the underlying mechanisms of ECM remodeling in CRC.

Machine-guided design of synthetic cell type-specific cis-regulatory elements

Cis-regulatory elements (CREs) control gene expression, orchestrating tissue identity, developmental timing, and stimulus responses, which collectively define the thousands of unique cell types in the body. While there is great potential for strategically incorporating CREs in therapeutic or biotechnology applications that require tissue specificity, there is no guarantee that an optimal CRE for an intended purpose has arisen naturally through evolution. Here, we present a platform to engineer and validate synthetic CREs capable of driving gene expression with programmed cell type specificity. We leverage innovations in deep neural network modeling of CRE activity across three cell types, efficient in silico optimization, and massively parallel reporter assays (MPRAs) to design and empirically test thousands of CREs. Through in vitro and in vivo validation, we show that synthetic sequences outperform natural sequences from the human genome in driving cell type-specific expression. Synthetic sequences leverage unique sequence syntax to promote activity in the on-target cell type and simultaneously reduce activity in off-target cells. Together, we provide a generalizable framework to prospectively engineer CREs and demonstrate the required literacy to write regulatory code that is fit-for-purpose in vivo across vertebrates.

Caffeine Supplementation and FOXM1 Inhibition Enhance the Antitumor Effect of Statins in Neuroblastoma

High-risk neuroblastoma exhibits transcriptional activation of the mevalonate pathway that produces cholesterol and nonsterol isoprenoids. A better understanding of how this metabolic reprogramming contributes to neuroblastoma development could help identify potential prevention and treatment strategies. Here, we report that both the cholesterol and nonsterol geranylgeranyl-pyrophosphate branches of the mevalonate pathway are critical to sustain neuroblastoma cell growth. Blocking the mevalonate pathway by simvastatin, a cholesterol-lowering drug, impeded neuroblastoma growth in neuroblastoma cell line xenograft, patient-derived xenograft (PDX), and TH-MYCN transgenic mouse models. Transcriptional profiling revealed that the mevalonate pathway was required to maintain the FOXM1-mediated transcriptional program that drives mitosis. High FOXM1 expression contributed to statin resistance and led to a therapeutic vulnerability to the combination of simvastatin and FOXM1 inhibition. Furthermore, caffeine synergized with simvastatin to inhibit the growth of neuroblastoma cells and PDX tumors by blocking statin-induced feedback activation of the mevalonate pathway. This function of caffeine depended on its activity as an adenosine receptor antagonist, and the A2A adenosine receptor antagonist istradefylline, an add-on drug for Parkinson's disease, could recapitulate the synergistic effect of caffeine with simvastatin. This study reveals that the FOXM1-mediated mitotic program is a molecular statin target in cancer and identifies classes of agents for maximizing the therapeutic efficacy of statins, with implications for treatment of high-risk neuroblastoma.

SIGNIFICANCE

Caffeine treatment and FOXM1 inhibition can both enhance the antitumor effect of statins by blocking the molecular and metabolic processes that confer statin resistance, indicating potential combination therapeutic strategies for neuroblastoma. See related commentary by Stouth et al., p. 2091.

Transcription Factor ELF1 Modulates Cisplatin Sensitivity in Prostate Cancer by Targeting MEIS Homeobox 2

As a widely used first-line agent for prostate cancer treatment, cisplatin is facing drug resistance which has resulted in chemotherapy failure in many prostate cancer patients, while the related molecular mechanisms remain unclear. In this study, we discovered that MEIS homeobox 2 (MEIS2) was lowly expressed in prostate cancer tissues by bioinformatics analysis, which had a close connection with the T stage and N stage of the tumor. Cell function experiments demonstrated that MEIS2 overexpression was capable of significantly suppressing proliferation of tumor cells, arresting prostate cancer cells in G0/G1 phase, and promoting DNA damage, thereby enhancing the sensitivity of prostate cancer to cisplatin. Dual-luciferase assay and chromatin co-immunoprecipitation (ChIP) assays confirmed the binding relationship between MEIS2 and ELF1. The results of rescue assay showed that ELF1 could promote DNA damage and enhance the sensitivity of tumor cells to cisplatin by activating MEIS2. In conclusion, the results of this study demonstrated that ELF1 could modulate DNA damage through activating MEIS2 and thus enhance cisplatin sensitivity in prostate cancer. This study suggested that the ELF1/MEIS2 axis may be a therapeutic target to strengthen cisplatin sensitivity in prostate cancer.

ERN1 dependent impact of glucose and glutamine deprivations on PBX3, PBXIP1, PAX6, MEIS1, and MEIS2 genes expression in U87 glioma cells

Objective. Homeobox genes play a fundamental role in the embryogenesis, but some of them have been linked to oncogenesis. The present study is aimed to investigate the impact of glucose and glutamine deprivations on the expression of homeobox genes such as PAX6 (paired box 6), PBX3 (PBX homeobox 3), PBXIP1 (PBX homeobox interacting protein 1), MEIS1 (MEIS homeobox 1), and MEIS2 in ERN1 knockdown U87 glioma cells with the intent to reveal the role of ERN1 (endoplasmic reticulum to nucleus signaling 1) signaling pathway on the endoplasmic reticulum stress dependent regulation of homeobox genes. Methods. The control (transfected by empty vector) and ERN1 knockdown (transfected by dominant-negative ERN1) U87 glioma cells were exposed to glucose and glutamine deprivations for 24 h. The cells RNA was extracted and reverse transcribed. The expression level of PAX6, PBX3, PBXIP1, MEIS1, and MEIS2 genes was evaluated by a real-time quantitative polymerase chain reaction analysis and normalized to ACTB. Results. It was found that glucose deprivation down-regulated the expression level of PAX6, MEIS1, and MEIS2 genes in control glioma cells, but did not significantly alter PBX3 and PBXIP1 genes expression. At the same time, ERN1 knockdown significantly modified the sensitivity of all studied genes to glucose deprivation. Other changes in gene expression were detected in control glioma cells under the glutamine deprivation. The expression of PBX3 and MEIS2 genes was down- while PAX6 and PBXIP1 genes up-regulated. Furthermore, ERN1 knockdown significantly modified the effect of glutamine deprivation on the majority of studied genes expression in U87 glioma cells. Conclusion. The results of the present study demonstrate that the exposure of U87 glioma cells under glucose and glutamine deprivations affected the expression of the majority of the studied homeobox genes and that the sensitivity of PAX6, PBX3, PBXIP1, MEIS1, and MEIS2 genes expression under these experimental conditions is mediated by ERN1, the major pathway of the endoplasmic reticulum stress signaling.

Activation of Oncogenic and Immune-Response Pathways Is Linked to Disease-Specific Survival in Merkel Cell Carcinoma

Simple Summary

Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer. Developing targeted therapies for MCC requires increased understanding of the mechanisms driving tumor progression. In this study, we aimed to identify genes, signaling pathways, and processes that play crucial roles in determining disease-specific survival in MCC. We analyzed the gene expression of 102 MCC tumors and identified genes that were upregulated among survivors and in patients who died from MCC. We cross-referenced these genes with online databases to identify the pathways and processes in which they function. Genes upregulated among survivors were mostly immune response related and genes upregulated among patients who died from MCC function in various pathways that promote cancer progression. These results could guide future studies investigating whether these genes and pathways could be used as prognostic markers, as markers to guide therapy selection, or as targets of precision therapy in MCC.

Abstract

Background: Merkel cell carcinoma (MCC) is a rare but highly aggressive neuroendocrine carcinoma of the skin with a poor prognosis. Improving the prognosis of MCC by means of targeted therapies requires further understanding of the mechanisms that drive tumor progression. In this study, we aimed to identify the genes, processes, and pathways that play the most crucial roles in determining MCC outcomes. Methods: We investigated transcriptomes generated by RNA sequencing of formalin-fixed paraffin-embedded tissue samples of 102 MCC patients and identified the genes that were upregulated among survivors and in patients who died from MCC. We subsequently cross-referenced these genes with online databases to investigate the functions and pathways they represent. We further investigated differential gene expression based on viral status in patients who died from MCC. Results: We found several novel genes associated with MCC-specific survival. Genes upregulated in patients who died from MCC were most notably associated with angiogenesis and the PI3K-Akt and MAPK pathways; their expression predominantly had no association with viral status in patients who died from MCC. Genes upregulated among survivors were largely associated with antigen presentation and immune response. Conclusion: This outcome-based discrepancy in gene expression suggests that these pathways and processes likely play crucial roles in determining MCC outcomes.

Dlx1/2-dependent expression of Meis2 promotes neuronal fate determination in the mammalian striatum

The striatum is a central regulator of behavior and motor function through the actions of D1 and D2 medium-sized spiny neurons (MSNs), which arise from a common lateral ganglionic eminence (LGE) progenitor. The molecular mechanisms of cell fate specification of these two neuronal subtypes are incompletely understood. Here, we found that deletion of murine Meis2, which is highly expressed in the LGE and derivatives, led to a large reduction in striatal MSNs due to a block in their differentiation. Meis2 directly binds to the Zfp503 and Six3 promoters and is required for their expression and specification of D1 and D2 MSNs, respectively. Finally, Meis2 expression is regulated by Dlx1/2 at least partially through the enhancer hs599 in the LGE subventricular zone. Overall, our findings define a pathway in the LGE whereby Dlx1/2 drives expression of Meis2, which subsequently promotes the fate determination of striatal D1 and D2 MSNs via Zfp503 and Six3.

LncRNA ILF3-AS1 promotes cell migration, invasion and EMT process in hepatocellular carcinoma via the miR-628-5p/MEIS2 axis to activate the Notch pathway

BACKGROUND

Long non-coding RNAs (lncRNAs) are essential indicators for hepatocellular carcinoma. LncRNAs can exert the same functions as their antisense mRNAs. ILF3 is an oncogene in hepatocellular carcinoma. ILF3 divergent transcript (ILF3-AS1) is the antisense RNA of ILF3, and has been reported as an oncogene in various cancers.

AIMS

To explore the role of lncRNA ILF3-AS1 in malignant phenotypes of hepatocellular carcinoma cells.

METHODS AND RESULTS

RT-qPCR analysis revealed that ILF3-AS1 was significantly upregulated in hepatocellular carcinoma cells. The hepatocellular carcinoma cell viability was suppressed by silenced ILF3-AS1. Transwell and wound healing assays showed that ILF3-AS1 downregulation inhibited cell invasion and migration. The levels of proteins associated with epithelial-mesenchymal transition (EMT) process and the Notch pathway were detected by western blot analysis. Luciferase reporter, RNA pull down and RIP assays were used to investigate the relationship between ILF3-AS1 and downstream target genes. ILF3-AS1 competed with meis homeobox 2 (MEIS2) for miR-628-5p in hepatocellular carcinoma cells. ILF3-AS1 elevated the levels of key proteins on the Notch pathway. Rescue assays demonstrated that MEIS2 reversed the antitumor effects of silenced ILF3-AS1 on hepatocellular carcinoma. In vivo assays demonstrated that ILF3-AS1 silencing inhibited the hepatocellular carcinoma tumor growth.

CONCLUSIONS

ILF3-AS1 promoted hepatocellular carcinoma progression via the Notch pathway and miR-628-5p/MEIS2 axis.

Placental Expression of the Forelimb Patterning Transcription Factor MEIS2 in Trisomy 15

BackgroundObservations of first trimester human trisomy 15 (T15) embryos have identified meromelic changes in the upper limbs. These changes are similar to those observed in animal studies investigating the effects of overexpression of Meis2, a signaling transcription factor expressed during forelimb development. Although it would be exceedingly difficult to assess MEIS2 expression in the human embryonic arm, MEIS2 has been reported as consistently expressed in first trimester placental villus stroma. Methods: This study addresses whether gene dosage effect might underlie meromelia in T15 by comparing MEIS2 expression in placentas from T15 and euploid spontaneous abortions employing manual and automated assessment of MEIS2 immunohistochemical scoring. Results: Average MEIS2 expression is increased in T15 first trimester placental tissue compared to euploid controls but that the difference is marginal. Manual and automated scoring showed moderately strong correlation. Conclusion: Extrapolation of these results suggests MEIS2 overexpression may not be required for meromelia in T15.

Molecular Mechanisms of Cereblon-Interacting Small Molecules in Multiple Myeloma Therapy

Thalidomide analogues (or immunomodulatory imide drugs, IMiDs) are cornerstones in the treatment of multiple myeloma (MM). These drugs bind Cereblon (CRBN), a receptor for the Cullin-ring 4 ubiquitin-ligase (CRL4) complex, to modify its substrate specificity. IMiDs mediate CRBN-dependent engagement and proteasomal degradation of ‘neosubstrates’, Ikaros (IKZF1) and Aiolos (IKZF3), conveying concurrent antimyeloma activity and T-cell costimulation. There is now a greater understanding of physiological CRBN functions, including endogenous substrates and chaperone activity. CRISPR Cas9-based genome-wide screening has further elucidated the complex cellular machinery implicated in IMiD sensitivity, including IKZF1/3-independent mechanisms. New-generation IMiD derivatives with more potent anti-cancer properties—the CELMoDs (Cereblon E3 ligase modulators)—are now being evaluated. Rational drug design also allows ‘hijacking’ of CRL4^CRBN utilising proteolysis targeting chimeras (PROTACs) to convey entirely distinct substrate repertoires. As all these chemotypes—thalidomide, IMiDs, CELMoDs and PROTACs—engage CRBN and modify its functions, we describe them here in aggregate as ‘CRBN-interacting small molecules’ (CISMs). In this review, we provide a contemporary summary of the biological consequences of CRBN modulation by CISMs. Detailed molecular insight into CRBN–CISM interactions now provides an opportunity to more effectively target previously elusive cancer dependencies, representing a new and powerful tool for the implementation of precision medicine.

LINC01234 aggravates cell growth and migration of triple-negative breast cancer by activating the Wnt pathway

Triple-negative breast cancer (TNBC) is a common cancer with increasing incidence and mortality in female. Increasing studies have revealed that long noncoding RNAs (lncRNAs) are novel molecules regulating tumors. Long intergenic non-protein coding RNA 1234 (LINC01234) has been demonstrated to function as an oncogene in several tumors. However, the role of LINC01234 in TNBC remains unelucidated. Herein, RT-qPCR showed that LINC01234 expression was upregulated in both TNBC tissues and cell lines. Functionally, knockdown of LINC01234 suppressed proliferation, migration, invasion, epithelial-mesenchymal transition (EMT) process, and promoted apoptosis in TNBC cells. Xenograft mouse models revealed that LINC01234 downregulation inhibited TNBC tumor growth in vivo. Furthermore, LINC01234 was transcriptionally elevated by Sp1 transcription factor (SP1) in TNBC cells. Mechanistically, LINC01234 interacted with miR-525-5p and miR-525-5p targeted MEIS2. Rescue assays manifested that MEIS2 overexpression rescued the cellular processes inhibited by silenced LINC01234. Moreover, we validated that LINC01234 regulated the activation of the Wnt pathway through modulating MEIS2 in TNBC cells. In conclusion, LINC01234 aggravated TNBC cell growth, migration, invasion and EMT by modulating the miR-525-5p/MEIS2 axis and activating the Wnt/β-catenin signaling pathway.

MEIS2 Is an Adrenergic Core Regulatory Transcription Factor Involved in Early Initiation of TH-MYCN-Driven Neuroblastoma Formation

Simple Summary

Neuroblastoma is a pediatric tumor originating from the sympathetic nervous system responsible for 10–15% of all childhood cancer deaths. Half of all neuroblastoma patients present with high-risk disease, of which nearly 50% relapse and die of their disease. In addition, standard therapies cause serious lifelong side effects and increased risk for secondary tumors. Further research is crucial to better understand the molecular basis of neuroblastomas and to identify novel druggable targets. Neuroblastoma tumorigenesis has to this end been modeled in both mice and zebrafish. Here, we present a detailed dissection of the gene expression patterns that underlie tumor formation in the murine TH-MYCN-driven neuroblastoma model. We identified key factors that are putatively important for neuroblastoma tumor initiation versus tumor progression, pinpointed crucial regulators of the observed expression patterns during neuroblastoma development and scrutinized which factors could be innovative and vulnerable nodes for therapeutic intervention.

Abstract

Roughly half of all high-risk neuroblastoma patients present with MYCN amplification. The molecular consequences of MYCN overexpression in this aggressive pediatric tumor have been studied for decades, but thus far, our understanding of the early initiating steps of MYCN-driven tumor formation is still enigmatic. We performed a detailed transcriptome landscaping during murine TH-MYCN-driven neuroblastoma tumor formation at different time points. The neuroblastoma dependency factor MEIS2, together with ASCL1, was identified as a candidate tumor-initiating factor and shown to be a novel core regulatory circuit member in adrenergic neuroblastomas. Of further interest, we found a KEOPS complex member (gm6890), implicated in homologous double-strand break repair and telomere maintenance, to be strongly upregulated during tumor formation, as well as the checkpoint adaptor Claspin (CLSPN) and three chromosome 17q loci CBX2, GJC1 and LIMD2. Finally, cross-species master regulator analysis identified FOXM1, together with additional hubs controlling transcriptome profiles of MYCN-driven neuroblastoma. In conclusion, time-resolved transcriptome analysis of early hyperplastic lesions and full-blown MYCN-driven neuroblastomas yielded novel components implicated in both tumor initiation and maintenance, providing putative novel drug targets for MYCN-driven neuroblastoma.

Identification of novel biomarkers of prostate cancer through integrated analysis

Background

The current methods adopted to screen for prostate cancer (PCa) can sometimes be misleading and inaccurate. Moreover, for advanced stages of PCa, the current effect of treatment is not satisfactory for some patients. Accordingly, we aimed to identify new biomarkers for the diagnosis and prognosis of PCa.

Methods

A series of bioinformatic tools were utilized to search for potential new biomarkers of PCa and analyze their functions, expression, clinical relevance, prognostic value, and underlying mechanisms.

Results

Although ASPN was overexpressed in PCa, EDN3, PENK, MEIS2, IGF1, and CXCL12 were downregulated. The univariate Cox regression analysis showed that abnormally high expression of ASPN and low expression of other genes predicted worse prognosis. Moreover, the multivariate Cox regression analysis showed that ASPN, PENK, and MEIS2 were independently associated with the overall survival (OS) of patients, whereas other markers were not. The outcomes of gene ontology and gene set enrichment analysis showed that the expression levels of these genes might be associated with cell proliferation and infiltration of immune cells in PCa.

Conclusions

We demonstrated that ASPN, EDN3, PENK, MEIS2, IGF1, and CXCL12 are possibly novel diagnostic indicators for PCa, whereas ASPN, PENK, and MEIS2 show appealing potential to predict the prognosis of this disease.

Effect of myeloid ecotropic viral integration site (MEIS) family genes on tumor microenvironment remodeling and its potential therapeutic effect

Background

The myeloid ecotropic viral integration site (MEIS) family of genes is related to the occurrence, development, and outcome of many cancers. However, its role in the immune and tumor microenvironment (TME) is unclear. This study explored the relationship between the expression of MEIS genes and patient survival, immune subtypes, TME, tumor stem cell correlation, and drug sensitivity in cancer.

Methods

We used The Cancer Genome Atlas pan-cancer data to analyze the expression of the MEIS family genes. Kaplan-Meier analysis and univariate Cox proportional hazard regression model were used to detect the relationship between gene expression and overall survival. Analysis of variance was used to explore the relationship between the MEIS family and the immune components in the tumor, and the ESTIMATE algorithm was used to calculate the proportion and level of tumor-infiltrating immune cells. Spearman and Pearson’s correlation tests were carried out to detect the relationship between MEIS and the characteristics of tumor stem cells and drug sensitivity.

Results

The MEIS family of genes shows different expression profiles in different cancers, with substantial inter- and intra-cancer heterogeneity. Among them, MEIS3 was upregulated in most cancers, whereas MEIS2 was downregulated. The change in MEIS gene expression was usually related to overall survival, but whether a member of the MEIS family was a risk factor or a protective factor was cancer-dependent. Immune component analysis suggested that the role of MEIS genes in promoting or inhibiting cancer may be related to different degrees of immune silencing. Further, there were varying degrees of correlation between MEIS gene expression and cancer cell stemness characteristics. It was also found that MEIS genes, especially MEIS1 and MEIS2, may be related to chemotherapy resistance.

Conclusions

We explored the expression, prognostic relationship, molecular characteristics, and effects on immunity and TME of the MEIS gene family in cancer. Our results suggest that MEIS members should be studied as independent entities in different types of cancer. The MEIS gene family may be a potential target for cancer therapy, but further experiments are needed to confirm this.

Oncogenic and tumor suppressor function of MEIS and associated factors

MEIS proteins are historically associated with tumorigenesis, metastasis, and invasion in cancer. MEIS and associated PBX-HOX proteins may act as tumor suppressors or oncogenes in different cellular settings. Their expressions tend to be misregulated in various cancers. Bioinformatic analyses have suggested their upregulation in leukemia/lymphoma, thymoma, pancreas, glioma, and glioblastoma, and downregulation in cervical, uterine, rectum, and colon cancers. However, every cancer type includes, at least, a subtype with high MEIS expression. In addition, studies have highlighted that MEIS proteins and associated factors may function as diagnostic or therapeutic biomarkers for various diseases. Herein, MEIS proteins and associated factors in tumorigenesis are discussed with recent discoveries in addition to how they could be modulated by noncoding RNAs or newly developed small-molecule MEIS inhibitors.

Chimera induced protein degradation: PROTACs and beyond

Ubiquitin-proteasome system, autophagy-lysosome pathway and N-end rule pathway are crucial protein quality control mechanisms in human body. Hijacking these endogenous protein degrading measures by chimera degraders could be a revolutionary strategy for the discovery of small-molecule drugs. As the most advanced chimera degraders, PROTACs have demonstrated the potential by delivering two drug candidates into clinical trials. The development of chimera degraders exploiting these three pathways are reviewed, a focus is given on the chemical structures and their influences on biological effects from a viewpoint of medicinal chemistry.

Absence of central tolerance in Aire-deficient mice synergizes with immune-checkpoint inhibition to enhance antitumor responses

The endogenous anti-tumor responses are limited in part by the absence of tumor-reactive T cells, an inevitable consequence of thymic central tolerance mechanisms ensuring prevention of autoimmunity. Here we show that tumor rejection induced by immune checkpoint blockade is significantly enhanced in Aire-deficient mice, the epitome of central tolerance breakdown. The observed synergy in tumor rejection extended to different tumor models, was accompanied by increased numbers of activated T cells expressing high levels of Gzma, Gzmb, Perforin, Cxcr3, and increased intratumoural levels of Cxcl9 and Cxcl10 compared to wild-type mice. Consistent with Aire's central role in T cell repertoire selection, single cell TCR sequencing unveiled expansion of several clones with high tumor reactivity. The data suggest that breakdown in central tolerance synergizes with immune checkpoint blockade in enhancing anti-tumor immunity and may serve as a model to unmask novel anti-tumor therapies including anti-tumor TCRs, normally purged during central tolerance.

Identification of Key Genes in Association with Progression and Prognosis in Cervical Squamous Cell Carcinoma

Cervical cancer remains a primary cause of female death in developing countries, but its prognosis can be greatly improved if patients are diagnosed earlier. In the present study, we screened the common differentially expressed genes (DEGs) of cervical squamous cell carcinoma (CESC) from dataset GSE7803, Gene Expression Omnibus, and The Cancer Genome Atlas databases. An integrated bioinformatics analysis was performed based on these DEGs for their enrichment in functions and pathways, interaction network, prognostic signature, and candidate molecular drugs. As a result, 164 (114 upregulated and 47 downregulated) DEGs of CESC were identified for further investigation. We then conducted the gene ontology term enrichment and Kyoto Encyclopedia of Genes and Genomes Pathway analyses to reveal the underlying functions and pathways of these DEGs. In the protein-protein interaction network, hub module and hub genes were identified. Five genes of significant prognostic value-DSG2, ITM2A, CENPM, RIBC2, and MEIS2-were identified by prognostic signature analysis and used to construct a risk linear model. Further validation and investigation suggested DSG2 might be a key gene in CESC prognosis. We then identified two candidate small molecules (trichostatin A and tanespimycin) against CESC. Further validation and exploration of these hub genes are warranted for future prospect in clinical applications.

Epigenetic silencing of MEIS2 in prostate cancer recurrence

Background

Current diagnostic and prognostic tools for prostate cancer (PC) are suboptimal, resulting in overdiagnosis and overtreatment of clinically insignificant tumors. Thus, to improve the management of PC, novel biomarkers are urgently needed.

Results

In this study, we integrated genome-wide methylome (Illumina 450K DNA methylation array (450K)) and RNA sequencing (RNAseq) data performed in a discovery set of 27 PC and 15 adjacent normal (AN) prostate tissue samples to identify candidate driver genes involved in PC development and/or progression. We found significant enrichment for homeobox genes among the most aberrantly methylated and transcriptionally dysregulated genes in PC. Specifically, homeobox gene MEIS2 (Myeloid Ecotropic viral Insertion Site 2) was significantly hypermethylated (p < 0.0001, Mann-Whitney test) and transcriptionally downregulated (p < 0.0001, Mann-Whitney test) in PC compared to non-malignant prostate tissue in our discovery sample set, which was also confirmed in an independent validation set including > 500 PC and AN tissue samples in total (TCGA cohort analyzed by 450K and RNAseq). Furthermore, in three independent radical prostatectomy (RP) cohorts (n > 700 patients in total), low MEIS2 transcriptional expression was significantly associated with poor biochemical recurrence (BCR) free survival (p = 0.0084, 0.0001, and 0.0191, respectively; log-rank test). Next, we analyzed another RP cohort consisting of > 200 PC, AN, and benign prostatic hyperplasia (BPH) samples by quantitative methylation-specific PCR (qMSP) and found that MEIS2 was significantly hypermethylated (p < 0.0001, Mann-Whitney test) in PC compared to non-malignant prostate tissue samples (AN and BPH) with an AUC > 0.84. Moreover, in this cohort, aberrant MEIS2 hypermethylation was significantly associated with post-operative BCR (p = 0.0068, log-rank test), which was subsequently confirmed (p = 0.0067; log-rank test) in the independent TCGA validation cohort (497 RP patients; 450K data).

Conclusions

To the best of our knowledge, this is the first study to investigate, demonstrate, and independently validate a prognostic biomarker potential for MEIS2 at the transcriptional expression level and at the DNA methylation level in PC.

MEIS2C and MEIS2D promote tumor progression via Wnt/β-catenin and hippo/YAP signaling in hepatocellular carcinoma

Background

MEIS2 has been identified as one of the key transcription factors in the gene regulatory network in the development and pathogenesis of human cancers. Our study aims to identify the regulatory mechanisms of MEIS2 in hepatocellular carcinoma (HCC), which could be targeted to develop new therapeutic strategies.

Methods

The variation of MEIS2 levels were assayed in a cohort of HCC patients. The proliferation, clone-formation, migration, and invasion abilities of HCC cells were measured to analyze the effects of MEIS2C and MEIS2D (MEIS2C/D) knockdown with small hairpin RNAs in vitro and in vivo. Chromatin immunoprecipitation (ChIP) was performed to identify MEIS2 binding site. Immunoprecipitation and immunofluorescence assays were employed to detect proteins regulated by MEIS2.

Results

The expression of MEIS2C/D was increased in the HCC specimens when compared with the adjacent noncancerous liver (ANL) tissues. Moreover, MEIS2C/D expression negatively correlated with the prognosis of HCC patients. On the other hand, knockdown of MEIS2C/D could inhibit proliferation and diminish migration and invasion of hepatoma cells in vitro and in vivo. Mechanistically, MESI2C activated Wnt/β-catenin pathway in cooperation with Parafibromin (CDC73), while MEIS2D suppressed Hippo pathway by promoting YAP nuclear translocation via miR-1307-3p/LATS1 axis. Notably, CDC73 could directly either interact with MEIS2C/β-catenin or MEIS2D/YAP complex, depending on its tyrosine-phosphorylation status.

Conclusions

Our studies indicate that MEISC/D promote HCC development via Wnt/β-catenin and Hippo/YAP signaling pathways, highlighting the complex molecular network of MEIS2C/D in HCC pathogenesis. These results suggest that MEISC/D may serve as a potential novel therapeutic target for HCC.

MEIS transcription factors in development and disease

MEIS transcription factors are key regulators of embryonic development and cancer. Research on MEIS genes in the embryo and in stem cell systems has revealed novel and surprising mechanisms by which these proteins control gene expression. This Primer summarizes recent findings about MEIS protein activity and regulation in development, and discusses new insights into the role of MEIS genes in disease, focusing on the pathogenesis of solid cancers.

Inhibition of Senescence-Associated Genes Rb1 and Meis2 in Adult Cardiomyocytes Results in Cell Cycle Reentry and Cardiac Repair Post-Myocardial Infarction

Background Myocardial infarction results in a large-scale cardiomyocyte loss and heart failure due to subsequent pathological remodeling. Whereas zebrafish and neonatal mice have evident cardiomyocyte expansion following injury, adult mammalian cardiomyocytes are principally nonproliferative. Despite historical presumptions of stem cell-mediated cardiac regeneration, numerous recent studies using advanced lineage-tracing methods demonstrated that the only source of cardiomyocyte renewal originates from the extant myocardium; thus, the augmented proliferation of preexisting adult cardiomyocytes remains a leading therapeutic approach toward cardiac regeneration. In the present study we investigate the significance of suppressing cell cycle inhibitors Rb1 and Meis2 to promote adult cardiomyocyte reentry to the cell cycle. Methods and Results In vitro experiments with small interfering RNA-mediated simultaneous knockdown of Rb1 and Meis2 in both adult rat cardiomyocytes, isolated from 12-week-old Fischer rats, and human induced pluripotent stem cell-derived cardiomyocytes showed a significant increase in cell number, a decrease in cell size, and an increase in mononucleated cardiomyocytes. In vivo, a hydrogel-based delivery method for small interfering RNA-mediated silencing of Rb1 and Meis2 is utilized following myocardial infarction. Immunofluorescent imaging analysis revealed a significant increase in proliferation markers 5-ethynyl-2'-deoxyuridine, PH3, KI67, and Aurora B in adult cardiomyocytes as well as improved cell survivability with the additional benefit of enhanced peri-infarct angiogenesis. Together, this intervention resulted in a reduced infarct size and improved cardiac function post-myocardial infarction. Conclusions Silencing of senescence-inducing pathways in adult cardiomyocytes via inhibition of Rb1 and Meis2 results in marked cardiomyocyte proliferation and increased protection of cardiac function in the setting of ischemic injury.

MEIS2 promotes cell migration and invasion in colorectal cancer

Colorectal cancer (CRC) is one of the most common types of malignancy worldwide. Distant metastasis is a key cause of CRC-associated mortality. MEIS2 has been identified to be dysregulated in several types of human cancer. However, the mechanisms underlying the regulatory role of MEIS2 in CRC metastasis remain largely unknown. For the first time, the present study demonstrated that MEIS2 serves a role as a promoter of metastasis in CRC. In vivo and in vitro experiments revealed that knockdown of MEIS2 significantly suppressed CRC migration, invasion and the epithelial-mesenchymal transition. Furthermore, microarray and bioinformatics analyses were performed to investigate the underlying mechanisms of MEIS2 in the regulation of CRC metastasis. Additionally, it was identified that a high expression of MEIS2 was significantly associated with a shorter overall survival time for patients with CRC. The present study demonstrated that MEIS2 may serve as a novel biomarker for CRC.

The homeobox transcription factor MEIS2 is a regulator of cancer cell survival and IMiDs activity in Multiple Myeloma: modulation by Bromodomain and Extra-Terminal (BET) protein inhibitors

The transcription factor Myeloid Ecotropic Insertion Site 2 (MEIS2) has been identified as a cellular substrate of the E3-ubiquitin ligase complex CRL4-cereblon (^CRL4CRBN) in crystal structure and by biochemical screen. Emerging evidence suggests that IMiDs can block MEIS2 from binding to CRBN facilitating the subsequent activation of a ^CRL4CRBN^IMiD-E3-ubiquitin ligase activity and proteasome-mediated degradation of critical substrates regulators of Multiple Myeloma (MM) cell survival and proliferation. Bromodomain and Extra-Terminal (BET) family of proteins are important epigenetic regulators involved in promoting gene expression of several oncogenes, and many studies have revealed important anticancer activities mediated by BET inhibitors (BETi) in hematologic malignancies including MM. Here, we investigated MEIS2 in MM, the role of this protein as a modulator of IMiDs activity and the ability of BETi to inhibit its expression. Our observations indicate that inhibition of MEIS2 in MM cells by RNA interference correlates with reduced growth, induction of apoptosis and enhanced efficacy of different anti-MM drugs. In addition, MEIS2 regulates the expression of Cyclin E/CCNE1 in MM and induction of apoptosis after treatment with the CDK inhibitor Seliciclib/Roscovitine. Interestingly, modulation of MEIS2 can regulate the expression of NKG2D and DNAM-1 NK cell-activating ligands and, importantly, the activity of IMiDs in MM cells. Finally, BETi have the ability to inhibit the expression of MEIS2 in MM, underscoring a novel anticancer activity mediated by these drugs. Our study provides evidence on the role of MEIS2 in MM cell survival and suggests therapeutic strategies targeting of MEIS2 to enhance IMiDs anti-myeloma activity.

Polypyrimidine tract binding protein 1 promotes lymphatic metastasis and proliferation of bladder cancer via alternative splicing of MEIS2 and PKM

Lymph node (LN) metastasis is the leading cause of bladder cancer-related mortality. Splicing factors facilitate cancer progression by modulating oncogenic variants, but it is unclear whether and how splicing factors regulate bladder cancer LN metastasis. In this study, Polypyrimidine tract binding protein 1 (PTBP1) expression was found to relate to bladder cancer LN metastasis, and was positively correlated with LN metastasis status, tumor stage, histological grade, and poor patient prognosis. Functional assays demonstrated that PTBP1 promoted bladder cancer cell migration, invasion, and proliferation in vitro, as well as LN metastasis and tumor growth in vivo. Mechanistic investigations revealed that PTBP1 upregulated MEIS2-L variant to promote metastasis and increased expression of PKM2 variant to enhance proliferation by modulating alternative mRNA splicing. Moreover, overexpression of MEIS2-L or PKM2 could rescue the oncogenic abilities of bladder cancer cells and the expression of MMP9 or CCND1 respectively after PTBP1 knockdown. In conclusion, our data demonstrate that PTBP1 induces bladder cancer LN metastasis and proliferation through an alternative splicing mechanism. PTBP1 may serve as a novel prognostic marker and therapeutic target for LN-metastatic bladder cancer.

In silico discovery of a FOXM1 driven embryonal signaling pathway in therapy resistant neuroblastoma tumors

Chemotherapy resistance is responsible for high mortality rates in neuroblastoma. MYCN, an oncogenic driver in neuroblastoma, controls pluripotency genes including LIN28B. We hypothesized that enhanced embryonic stem cell (ESC) gene regulatory programs could mark tumors with high pluripotency capacity and subsequently increased risk for therapy failure. An ESC miRNA signature was established based on publicly available data. In addition, an ESC mRNA signature was generated including the 500 protein coding genes with the highest positive expression correlation with the ESC miRNA signature score in 200 neuroblastomas. High ESC m(i)RNA expression signature scores were significantly correlated with poor neuroblastoma patient outcome specifically in the subgroup of MYCN amplified tumors and stage 4 nonamplified tumors. Further data-mining identified FOXM1, as the major predicted driver of this ESC signature, controlling a large set of genes implicated in cell cycle control and DNA damage response. Of further interest, re-analysis of published data showed that MYCN transcriptionally activates FOXM1 in neuroblastoma cells. In conclusion, a novel ESC m(i)RNA signature stratifies neuroblastomas with poor prognosis, enabling the identification of therapy-resistant tumors. The finding that this signature is strongly FOXM1 driven, warrants for drug design targeted at FOXM1 or key components controlling this pathway.

Predicting neuroblastoma using developmental signals and a logic-based model

Genomic information from human patient samples of pediatric neuroblastoma cancers and known outcomes have led to specific gene lists put forward as high risk for disease progression. However, the reliance on gene expression correlations rather than mechanistic insight has shown limited potential and suggests a critical need for molecular network models that better predict neuroblastoma progression. In this study, we construct and simulate a molecular network of developmental genes and downstream signals in a 6-gene input logic model that predicts a favorable/unfavorable outcome based on the outcome of the four cell states including cell differentiation, proliferation, apoptosis, and angiogenesis. We simulate the mis-expression of the tyrosine receptor kinases, trkA and trkB, two prognostic indicators of neuroblastoma, and find differences in the number and probability distribution of steady state outcomes. We validate the mechanistic model assumptions using RNAseq of the SHSY5Y human neuroblastoma cell line to define the input states and confirm the predicted outcome with antibody staining. Lastly, we apply input gene signatures from 77 published human patient samples and show that our model makes more accurate disease outcome predictions for early stage disease than any current neuroblastoma gene list. These findings highlight the predictive strength of a logic-based model based on developmental genes and offer a better understanding of the molecular network interactions during neuroblastoma disease progression.

Identification of genes expressed in a mesenchymal subset regulating prostate organogenesis using tissue and single cell transcriptomics

Prostate organogenesis involves epithelial growth controlled by inductive signalling from specialised mesenchymal subsets. To identify pathways active in mesenchyme we used tissue and single cell transcriptomics to define mesenchymal subsets and subset-specific transcript expression. We documented transcript expression using Tag-seq and RNA-seq in female rat Ventral Mesenchymal Pad (VMP) as well as adjacent urethra comprised of smooth muscle and peri-urethral mesenchyme. Transcripts enriched in female VMP were identified with Tag-seq of microdissected tissue, RNA-seq of cell populations, and single cells. We identified 400 transcripts as enriched in the VMP using bio-informatic comparisons of Tag-seq and RNA-seq data, and 44 were confirmed by single cell RNA-seq. Cell subset analysis showed that VMP and adjacent mesenchyme were composed of distinct cell types and that each tissue contained two subgroups. Markers for these subgroups were highly subset specific. Thirteen transcripts were validated by qPCR to confirm cell specific expression in microdissected tissues, as well as expression in neonatal prostate. Immunohistochemical staining demonstrated that Ebf3 and Meis2 showed a restricted expression pattern in female VMP and prostate mesenchyme. We conclude that prostate inductive mesenchyme shows limited cellular heterogeneity and that transcriptomic analysis identified new mesenchymal subset transcripts associated with prostate organogenesis.

Meis2 as a critical player in MN1-induced leukemia

Meningioma 1 (MN1) is an independent prognostic marker for normal karyotype acute myeloid leukemia (AML), with high expression linked to all-trans retinoic acid resistance and poor survival. MN1 is also a potent and sufficient oncogene in murine leukemia models, strongly dependent on the MEIS1/AbdB-like HOX protein complex to transform common myeloid progenitors, block myeloid differentiation, and promote leukemic stem cell self-renewal. To identify key genes and pathways underlying leukemic activity, we functionally assessed MN1 cell phenotypic heterogeneity, revealing leukemic and non-leukemic subsets. Using gene expression profiling of these subsets combined with previously published comparisons of full-length MN1 and mutants with varying leukemogenic activity, we identified candidate genes critical to leukemia. Functional analysis identified Hlf and Hoxa9 as critical to MN1 in vitro proliferation, self-renewal and impaired myeloid differentiation. Although critical to transformation, Meis1 knockdown had little impact on these properties in vitro. However, we identified Meis2 as critical to MN1-induced leukemia, with essential roles in proliferation, self-renewal, impairment of differentiation and disease progression in vitro and in vivo. Here, we provide evidence of phenotypic and functional hierarchy in MN1-induced leukemic cells, characterise contributions of Hlf, Hoxa9 and Meis1 to in vitro leukemic properties, and reveal Meis2 as a novel player in MN1-induced leukemogenesis.

Akt/FoxM1 signaling pathway-mediated upregulation of MYBL2 promotes progression of human glioma

Background

MYB-related protein B (B-MYB/MYBL2), a member of the myeloblastosis family of transcription factors, has been reported for its role in the genesis and progression of tumors. Forkhead box M1 (FoxM1), another transcriptional factor, is considered to be an independent predictor of poor survival in many solid cancers. The aim of the present study was to investigate the clinical significance of the correlation between MYBL2 and FoxM1 in glioma and the possible mechanism of FoxM1and MYBL2 expression.

Methods

MYBL2 and FoxM1expression in cancerous tissues and cell lines were determined by reverse transcription-PCR (RT-PCR), Western blotting and immunostaining. The co-expression of MYBL2 and FoxM1 was analyzed in low-grade glioma (LGG) and glioblastoma (HGG) cohorts of TCGA using cBioportal and UCSC Xena. And, the role of MYBL2 and FoxM1 in glioma cell progression and the underlying mechanisms were studied by using small interfering RNA (si-RNA) and pcDNA3.1 + HAvectors. Furthermore, the effects of MYBL2 and FoxM1 in cell proliferation, cell cycle progression, apoptosis, migration, invasion, and adhesion were determined by cell proliferation assays, flow cytometry analysis, transwell migration and cell adhesion assay.

Results

MYBL2 and FoxM1 expression are significantly associated with clinical stages and overall survival of glioma patients. In cohorts of TCGA, patients with high MYBL2 but without radio-chemotherapy had the highest hazard ratio (adjusted HR = 5.29, 95% CI = 1.475–18.969, P < 0.05). Meanwhile, MYBL2 closely related to the FoxM1 expression in 79 glioma tissues (r = 0.742, p < 0.05) and LGG (r = 0.83) and HGG (r = 0.74) cohorts of TCGA. Down regulation of FoxM1 and MYBL2 by siRNAs induced the cell cycle arrest, apoptosis and EMT of glioma cells. Furthermore, inactivations of Akt/FoxM1 signaling by Akt inhibitor and siRNA-FoxM1 reduce the expression of MYBL2 in glioma cells.

Conclusions

MYBL2 is a key downstream factor of Akt/FoxM1 signaling to promote progression of human glioma, and could be a new candidate gene for molecular targeting therapy and biomarker for radiotherapy of glioma.

Trial registration

CTXY-1300041-3-2. ChiCTR-COC-15006186. Registered date: 13 September 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0573-6) contains supplementary material, which is available to authorized users.

HOXB13 mutations and binding partners in prostate development and cancer: Function, clinical significance, and future directions

The recent and exciting discovery of germline HOXB13 mutations in familial prostate cancer has brought HOX signaling to the forefront of prostate cancer research. An enhanced understanding of HOX signaling, and the co-factors regulating HOX protein specificity and transcriptional regulation, has the high potential to elucidate novel approaches to prevent, diagnose, stage, and treat prostate cancer. Toward our understanding of HOX biology in prostate development and prostate cancer, basic research in developmental model systems as well as other tumor sites provides a mechanistic framework to inform future studies in prostate biology. Here we describe our current understanding of HOX signaling in genitourinary development and cancer, current clinical data of HOXB13 mutations in multiple cancers including prostate cancer, and the role of HOX protein co-factors in development and cancer. These data highlight numerous gaps in our understanding of HOX function in the prostate, and present numerous potentially impactful mechanistic and clinical opportunities for future investigation.

A Constitutive Intrinsic Inflammatory Signaling Circuit Composed of miR-196b, Meis2, PPP3CC, and p65 Drives Prostate Cancer Castration Resistance

Androgen deprivation therapy is the most effective treatment for advanced prostate cancer, but almost all cancer eventually becomes castration resistant, and the underlying mechanisms are largely unknown. Here, we show that an intrinsic constitutively activated feedforward signaling circuit composed of IκBα/NF-κB(p65), miR-196b-3p, Meis2, and PPP3CC is formed during the emergence of castration-resistant prostate cancer (CRPC). This circuit controls the expression of stem cell transcription factors that drives the high tumorigenicity of CRPC cells. Interrupting the circuit by targeting its individual components significantly impairs the tumorigenicity and CRPC development. Notably, constitutive activation of IκBα/NF-κB(p65) in this circuit is not dependent on the activation of traditional IKKβ/NF-κB pathways that are important in normal immune responses. Therefore, our studies present deep insight into the bona fide mechanisms underlying castration resistance and provide the foundation for the development of CRPC therapeutic strategies that would be highly efficient while avoiding indiscriminate IKK/NF-κB inhibition in normal cells.

Insights into a Critical Role of the FOXO3a-FOXM1 Axis in DNA Damage Response and Genotoxic Drug Resistance

FOXO3a and FOXM1 are two forkhead transcription factors with antagonistic roles in cancer and DNA damage response. FOXO3a functions like a typical tumour suppressor, whereas FOXM1 is a potent oncogene aberrantly overexpressed in genotoxic resistant cancers. FOXO3a not only represses FOXM1 expression but also its transcriptional output. Recent research has provided novel insights into a central role for FOXO3a and FOXM1 in DNA damage response. The FOXO3a-FOXM1 axis plays a pivotal role in DNA damage repair and the accompanied cellular response through regulating the expression of genes essential for DNA damage sensing, mediating, signalling and repair as well as for senescence, cell cycle and cell death control. In this manner, the FOXO3a-FOXM1 axis also holds the key to cell fate decision in response to genotoxic therapeutic agents and controls the equilibrium between DNA repair and cell termination by cell death or senescence. As a consequence, inhibition of FOXM1 or reactivation of FOXO3a in cancer cells could enhance the efficacy of DNA damaging cancer therapies by decreasing the rate of DNA repair and cell survival while increasing senescence and cell death. Conceptually, targeting FOXO3a and FOXM1 may represent a promising molecular therapeutic option for improving the efficacy and selectivity of DNA damage agents, particularly in genotoxic agent resistant cancer. In addition, FOXO3a, FOXM1 and their downstream transcriptional targets may also be reliable diagnostic biomarkers for predicting outcome, for selecting therapeutic options, and for monitoring treatments in DNA-damaging agent therapy.

miR-134 Modulates the Proliferation of Human Cardiomyocyte Progenitor Cells by Targeting Meis2

Cardiomyocyte progenitor cells play essential roles in early heart development, which requires highly controlled cellular organization. microRNAs (miRs) are involved in various cell behaviors by post-transcriptional regulation of target genes. However, the roles of miRNAs in human cardiomyocyte progenitor cells (hCMPCs) remain to be elucidated. Our previous study showed that miR-134 was significantly downregulated in heart tissue suffering from congenital heart disease, underlying the potential role of miR-134 in cardiogenesis. In the present work, we showed that the upregulation of miR-134 reduced the proliferation of hCMPCs, as determined by EdU assay and Ki-67 immunostaining, while the inhibition of miR-134 exhibited an opposite effect. Both up- and downregulation of miR-134 expression altered the transcriptional level of cell-cycle genes. We identified Meis2 as the target of miR-134 in the regulation of hCMPC proliferation through bioinformatic prediction, luciferase reporter assay and western blot. The over-expression of Meis2 mitigated the effect of miR-134 on hCMPC proliferation. Moreover, miR-134 did not change the degree of hCMPC differentiation into cardiomyocytes in our model, suggesting that miR-134 is not required in this process. These findings reveal an essential role for miR-134 in cardiomyocyte progenitor cell biology and provide new insights into the physiology and pathology of cardiogenesis.

Meis3 is required for neural crest invasion of the gut during zebrafish enteric nervous system development

Loss of Meis3 leads to defects in enteric neural crest cell migration, number, and proliferation during colonization of the gut. This leads to colonic aganglionosis, in which the hindgut is devoid of neurons, identifying it as a novel candidate factor in the etiology of Hirschsprung’s disease during enteric nervous system development.

During development, vagal neural crest cells fated to contribute to the enteric nervous system migrate ventrally away from the neural tube toward and along the primitive gut. The molecular mechanisms that regulate their early migration en route to and entry into the gut remain elusive. Here we show that the transcription factor meis3 is expressed along vagal neural crest pathways. Meis3 loss of function results in a reduction in migration efficiency, cell number, and the mitotic activity of neural crest cells in the vicinity of the gut but has no effect on neural crest or gut specification. Later, during enteric nervous system differentiation, Meis3-depleted embryos exhibit colonic aganglionosis, a disorder in which the hindgut is devoid of neurons. Accordingly, the expression of Shh pathway components, previously shown to have a role in the etiology of Hirschsprung’s disease, was misregulated within the gut after loss of Meis3. Taken together, these findings support a model in which Meis3 is required for neural crest proliferation, migration into, and colonization of the gut such that its loss leads to severe defects in enteric nervous system development.

Differential lncRNA expression profiles in recurrent gliomas compared with primary gliomas identified by microarray analysis

Glioma, especially high-grade glioma, is highly malignant with high rate of recurrence and poor prognosis. The mechanisms of glioma progression and recurrence have not been elucidated. Previous studies showed that long non-coding RNAs (lncRNAs) involved in the development and progression of glioma. However, the roles of lncRNAs in the recurrence of glioma remain unknown. We use high throughput microarray to screen the differentially expressed lncRNAs and mRNAs in recurrence gliomas compared with primary gliomas. We found a total of 1,111 lncRNAs were differentially expressed in recurrent group. Among these, 639 lncRNAs were up-regulated, while 472 lncRNAs were down-regulated (fold Change ≥2.0). GO (Gene ontology) and pathway analysis revealed that the potential functions of differentially expressed lncRNAs were closely connected with the processes of cancer progression and pathogenesis. LncRNA classification and subgroup analysis further identified three important clusters of differentially expressed lncRNA-mRNA pairs which have potential gene regulatory functions. This study for the first time showed abundant differentially expressed lncRNAs in recurrent gliomas. Some lncRNAs may play important roles in glioma recurrence, such as previously reported H19, CRNDE, HOTAIRM1 or unreported AC016745.3, XLOC_001711, RP11-128A17.1. Moreover, this study set a basis for future researches on specific lncRNA which may contribute to the recurrence of glioma. Further studies on these lncRNAs will help to elucidate the mechanism of glioma recurrence at genetic level and find therapeutic targets for glioma patients.