Recruitment of LEF1 by Pontin chromatin modifier amplifies TGFBR2 transcription and activates TGFβ/SMAD signalling during gliomagenesis

Multipronged SMAD pathway targeting by lipophilic poly(β-amino ester) miR-590-3p nanomiRs inhibits mesenchymal glioblastoma growth and prolongs survival

ASBSTRACT

Despite aggressive therapy, glioblastoma (GBM) recurs in almost all patients and treatment options are very limited. Despite our growing understanding of how cellular transitions associate with relapse in GBM, critical gaps remain in our ability to block these molecular changes and treat recurrent disease. In this study we combine computational biology, forward-thinking understanding of miRNA biology and cutting-edge nucleic acid delivery vehicles to advance targeted therapeutics for GBM. Computational analysis of RNA sequencing from clinical GBM specimens identified TGFβ type II receptor (TGFBR2) as a key player in the mesenchymal transition associated with worse outcome in GBM. Mechanistically, we show that elevated levels of TGFBR2 is conducive to reduced temozolomide (TMZ) sensitivity. This effect is, at least partially, induced by stem-cell driving events coordinated by the reprogramming transcription factors Oct4 and Sox2 that lead to open chromatin states. We show that blocking TGFBR2 via molecular and pharmacological approaches decreases stem cell capacity and sensitivity of clinical recurrent GBM (rGBM) isolates to TMZ in vitro. Network analysis uncovered miR-590-3p as a tumor suppressor that simultaneously inhibits multiple oncogenic nodes downstream of TGFBR2. We also developed novel biodegradable lipophilic poly(β-amino ester) nanoparticles (LiPBAEs) for in vivo microRNA (miRNAs) delivery. Following direct intra-tumoral infusion, these nanomiRs efficiently distribute through the tumors. Importantly, miR-590-3p nanomiRs inhibited the growth and extended survival of mice bearing orthotopic human rGBM xenografts, with an apparent 30% cure rate. These results show that miRNA-based targeted therapeutics provide new opportunities to treat rGBM and bypass the resistance to standard of care therapy.

Functional analysis of cancer-associated germline risk variants

Single-nucleotide variants (SNVs) in regulatory DNA are linked to inherited cancer risk. Massively parallel reporter assays of 4,041 SNVs linked to 13 neoplasms comprising >90% of human malignancies were performed in pertinent primary human cell types and then integrated with matching chromatin accessibility, DNA looping and expression quantitative trait loci data to nominate 380 potentially regulatory SNVs and their putative target genes. The latter highlighted specific protein networks in lifetime cancer risk, including mitochondrial translation, DNA damage repair and Rho GTPase activity. A CRISPR knockout screen demonstrated that a subset of germline putative risk genes also enables the growth of established cancers. Editing one SNV, rs10411210 , showed that its risk allele increases rhophilin RHPN2 expression and stimulus-responsive RhoA activation, indicating that individual SNVs may upregulate cancer-linked pathways. These functional data are a resource for variant prioritization efforts and further interrogation of the mechanisms underlying inherited risk for cancer.

Epigenetic regulation of TGF-β pathway and its role in radiation response

PURPOSE

Transforming growth factor (TGF-β) plays a dual role in tumor progression as well as a pivotal role in radiation response. TGF-β-related epigenetic regulations, including DNA methylation, histone modifications (including methylation, acetylation, phosphorylation, ubiquitination), chromatin remodeling and non-coding RNA regulation, have been found to affect the occurrence and development of tumors as well as their radiation response in multiple dimensions. Due to the significance of radiotherapy in tumor treatment and the essential roles of TGF-β signaling in radiation response, it is important to better understand the role of epigenetic regulation mechanisms mediated by TGF-β signaling pathways in radiation-induced targeted and non-targeted effects.

CONCLUSIONS

By revealing the epigenetic mechanism related to TGF-β-mediated radiation response, summarizing the existing relevant adjuvant strategies for radiotherapy based on TGF-β signaling, and discovering potential therapeutic targets, we hope to provide a new perspective for improving clinical treatment.

ZMIZ2 facilitates hepatocellular carcinoma progression via LEF1 mediated activation of Wnt/β-catenin pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies with a high lethality rate. ZMIZ2 is a transcriptional co-activator implicated in various human diseases. However, the role and molecular mechanism of ZMIZ2 in HCC remains to be elucidated.

METHODS

The expression and prognostic value of ZMIZ2 in HCC was excavated from public databases and explored by bioinformatic analysis. Then the expression of ZMIZ2 and related genes was further validated by quantitative RT-PCR, western blotting, and immunohistochemistry. Loss and gain-of-function experiments were performed in vitro and in vivo to investigate the function of ZMIZ2 in HCC. In addition, transcriptome sequencing and immunoprecipitation was conducted to explore the potential molecular mechanisms of ZMIZ2.

RESULTS

ZMIZ2 was highly expressed in HCC and associated with poor prognosis. Silencing ZMIZ2 significantly inhibited HCC cell proliferation, cell cycle process, migration, and invasion in vitro, and also inhibited the progression of HCC in vivo. Additionally, ZMIZ2 expression was correlated with immune cell infiltration in HCC samples. Somatic mutation analysis showed that ZMIZ2 and TP53 mutations jointly affected the progression of HCC. Mechanistically, ZMIZ2 interacted with LEF1 to regulate malignant progression of HCC by activating the Wnt/β-catenin pathway.

CONCLUSION

ZMIZ2 was overexpressed in HCC and associated with poor prognosis. The overexpression of ZMIZ2 was corelated with malignant phenotype, and it facilitated HCC progression via LEF1-mediated activation of the Wnt/β-catenin pathway. Furthermore, ZMIZ2 could be served as a prognostic biomarker and a new therapeutic target for HCC.