RNA splicing analysis deciphers developmental hierarchies and reveals therapeutic targets in adult glioma.

Widespread alterations in RNA alternative splicing (AS) have been identified in adult gliomas. However, their regulatory mechanism, biological significance, and therapeutic potential remain largely elusive. Here, using a computational approach with both bulk and single cell RNA-sequencing, we uncover a prognostic AS signature linked with neural developmental hierarchies. Using advanced iPSC glioma models driven by glioma driver mutations, we show that this AS signature could be enhanced by EGFRvIII and inhibited by in situ IDH1 mutation. Functional validation of two isoform switching events in CERS5 and MPZL1 shows regulations of sphingolipid metabolism and SHP2 signaling, respectively. Analysis of upstream RNA binding proteins reveals PTBP1 as a key regulator of the AS signature where targeting of PTBP1 suppresses tumor growth and promotes the expression of a neuron marker TUJ1 in glioma stem-like cells. Overall, our data highlights the role of AS in impacting glioma malignance and heterogeneity and its potential as a therapeutic vulnerability for treating adult gliomas.

CREBZF mRNA nanoparticles suppress breast cancer progression through a positive feedback loop boosted by circPAPD4.

BACKGROUND: Breast cancer (BC) negatively impacts the health of women worldwide. Circular RNAs (circRNAs) are a group of endogenous RNAs considered essential regulatory factor in BC tumorigenesis and progression. However, the underlying molecular mechanisms of circRNAs remain unclear. METHODS: Expression levels of circPAPD4, miR-1269a, CREBZF, and ADAR1 in BC cell lines and tissues were measured using bioinformatics analysis, RT-qPCR, ISH, and IHC. Cell proliferation and apoptosis were measured using CCK8, EdU staining, flow cytometry, and TUNEL assays. Pearson correlation analysis, RNA pull-down, dual-luciferase reporter, and co-immunoprecipitation assays were used to explore the correlation among circPAPD4, miR-1269a, CREBZF, STAT3, and ADAR1. Effects of circPAPD4 overexpression on tumor progression were investigated using in vivo assays. Moreover, CREBZF mRNA delivered by polymeric nanoparticles (CREBZF-mRNA-NPs) was used to examine application value of our findings. RESULTS: CircPAPD4 expression was low in BC tissues and cells. Functionally, circPAPD4 inhibited proliferation and promoted apoptosis in vitro and in vivo. Mechanistically, circPAPD4 biogenesis was regulated by ADAR1. And circPAPD4 promoted CREBZF expression by competitively binding to miR-1269a. More importantly, CREBZF promoted circPAPD4 expression by suppressing STAT3 dimerization and ADAR1 expression, revealing a novel positive feedback loop that curbed BC progression. Systematic delivery of CREBZF-mRNA-NPs effectively induced CREBZF expression and activated the positive feedback loop of circPAPD4/miR-1269a/CREBZF/STAT3/ADAR1, which might suppress BC progression in vitro and in vivo. CONCLUSION: Our findings firstly illustrated that circPAPD4/miR-1269a/CREBZF/STAT3/ADAR1 positive feedback loop mediated BC progression, and delivering CREBZF mRNA nanoparticles suppressed BC progression in vitro and in vivo, which might provide novel insights into therapeutic strategies for breast cancer.

Suppressing circIDE/miR-19b-3p/RBMS1 axis exhibits promoting-tumour activity through upregulating GPX4 to diminish ferroptosis in hepatocellular carcinoma.

Ferroptosis is a newly characterized form of iron-dependent non-apoptotic cell death, which is closely associated with cancer progression. However, the functions and mechanisms in regulation of escaping from ferroptosis during hepatocellular carcinoma (HCC) progression remain unknown. In this study, we reported that the RNA binding motif single stranded interacting protein 1 (RBMS1) participated in HCC development，and functioned as a regulator of ferroptosis. Clinically, the downregulation of RBMS1 occurred in HCC tissues, and low RBMS1 expression was associated with worse HCC patients survival. Mechanistically, RBMS1 overexpression inhibited HCC cell growth by attenuating the expression of glutathione peroxidase 4 (GPX4)and further facilitated ferroptosis in vitro and in vivo. More importantly, a novel circIDE (hsa_circ_0000251) was identified to elevate RBMS1 expression via sponging miR-19b-3p in HCC cells. Collectively, our findings established circIDE/miR-19b-3p/RBMS1 axis as a regulator of ferroptosis, which could be a promising therapeutic target and prognostic factor.

Targeting tumor exosomal circular RNA cSERPINE2 suppresses breast cancer progression by modulating MALT1-NF-𝜠B-IL-6 axis of tumor-associated macrophages.

BACKGROUND: Circular RNAs (circRNAs) have important regulatory functions in cancer, but the role of circRNAs in the tumor microenvironment (TME) remains unclear. Moreover, we also explore the effects of si-circRNAs loaded in nanoparticles as therapeutic agent for anti-tumor in vivo. METHODS: We conducted bioinformatics analysis, qRT-PCR, EdU assays, Transwell assays, co-culture system and multiple orthotopic xenograft models to investigate the expression and function of circRNAs. Additionally, PLGA-based nanoparticles loaded with si-circRNAs were used to evaluate the potential of nanotherapeutic strategy in anti-tumor response. RESULTS: We identified oncogene SERPINE2 derived circRNA, named as cSERPINE2, which was notably elevated in breast cancer and was closely related to poor clinical outcome. Functionally, tumor exosomal cSERPINE2 was shuttled to tumor associated macrophages (TAMs) and enhanced the secretion of Interleukin-6 (IL-6), leading to increased proliferation and invasion of breast cancer cells. Furthermore, IL-6 in turn increased the EIF4A3 and CCL2 levels within tumor cells in a positive feedback mechanism, further enhancing tumor cSERPINE2 biogenesis and promoting the recruitment of TAMs. More importantly, we developed a PLGA-based nanoparticle loaded with si-cSERPINE2, which effectively attenuated breast cancer progression in vivo. CONCLUSIONS: Our study illustrates a novel mechanism that tumor exosomal cSERPINE2 mediates a positive feedback loop between tumor cells and TAMs to promote cancer progression, which may serve as a promising nanotherapeutic strategy for the treatment of breast cancer.

Splicing factor SNRPA associated with microvascular invasion promotes hepatocellular carcinoma metastasis through activating NOTCH1/Snail pathway and is mediated by circSEC62/miR-625-5p axis.

Microvascular invasion (MVI) is a crucial risk factor related to the metastasis of hepatocellular carcinoma (HCC), but the underlying mechanisms remain to be revealed. Characterizing the inherent mechanisms of MVI may aid in the development of effective treatment strategies to improve the prognosis of HCC patients with metastasis. Through the Gene Expression Omnibus (GEO) database, we identified that small nuclear ribonucleoprotein polypeptide A (SNRPA) was related to MVI in HCC. SNRPA was overexpressed in MVI-HCC and correlated with poor patient survival. Mechanistically, SNRPA promoted the epithelial-mesenchymal transition (EMT)-like process for HCC cells to accelerate metastasis by activating the NOTCH1/Snail pathway in vitro and in vivo. Importantly, circSEC62 upregulated SNRPA expression in HCC cells via miR-625-5p sponging. Taking these results together, our study identified a novel regulatory mechanism among SNRPA, miR-625-5p, circSEC62 and the NOTCH1/Snail pathway in HCC, which promoted metastasis of HCC and may provide effective suggestions for improving the prognosis of HCC patients with metastasis.

Spatially resolved proteomics via tissue expansion.

Spatially resolved proteomics is an emerging approach for mapping proteome heterogeneity of biological samples, however, it remains technically challenging due to the complexity of the tissue microsampling techniques and mass spectrometry analysis of nanoscale specimen volumes. Here, we describe a spatially resolved proteomics method based on the combination of tissue expansion with mass spectrometry-based proteomics, which we call Expansion Proteomics (ProteomEx). ProteomEx enables quantitative profiling of the spatial variability of the proteome in mammalian tissues at ~160 µm lateral resolution, equivalent to the tissue volume of 0.61 nL, using manual microsampling without the need for custom or special equipment. We validated and demonstrated the utility of ProteomEx for streamlined large-scale proteomics profiling of biological tissues including brain, liver, and breast cancer. We further applied ProteomEx for identifying proteins associated with Alzheimer's disease in a mouse model by comparative proteomic analysis of brain subregions.

The double homeobox a pseudogene 8 accelerates cell proliferation, migration, and invasion in colon cancer.

Double homeobox A pseudogene 8 (DUXAP8) is a known tumor promoter in several malignancies. Nonetheless, its function in colon cancer (CC) is indefinite. Herein, we explored the significance of DUXAP8 and its underlying mechanism in CC. Our data indicated that DUXAP8 was upregulated in CC, and it was related to advanced stages and lymph node metastases. Based on our Kaplan-Meier survival analysis, elevated DUXAP8 expression resulted in shorter patient overall survival (OS). Conversely, DUXAP8 silencing strongly suppressed cellular proliferation, migration and invasion in vitro. Based on our western blot analysis, DUXAP8 deficiency strongly inhibited the epithelial-mesenchymal transition (EMT) in vitro. Alternately, DUXAP8 overexpression accelerated cellular proliferation migration and invasion in CC. Finally, silencing DUXAP8 prevented tumorigenesis in a mouse xenograft model in vivo. Collectively, our results demonstrated that DUXAP8 regulates the occurrence and advancement of CC, and may serve as a regulatory hub for this disease.

Stratification of follicular thyroid tumours using data-independent acquisition proteomics and a comprehensive thyroid tissue spectral library.

Thyroid nodules occur in about 60% of the population. A major challenge in thyroid nodule diagnosis is to distinguish between follicular adenoma (FA) and carcinoma (FTC). Here, we present a comprehensive thyroid spectral library covering five types of thyroid tissues. This library includes 121 960 peptides and 9941 protein groups. This spectral library can be used to quantify up to 7863 proteins from thyroid tissues, and can also be used to develop parallel reaction monitoring (PRM) assays for targeted protein quantification. Next, to stratify follicular thyroid tumours, we compared the proteomes of 24 FA and 22 FTC samples, and identified 204 differentially expressed proteins (DEPs). Our data suggest altered ferroptosis pathways in malignant follicular carcinoma. In all, 31 selected proteins effectively distinguished follicular tumours. Of those DEPs, nine proteins were further verified by PRM in an independent cohort of 18 FA and 19 FTC. Together, we present a comprehensive spectral library for DIA and targeted proteomics analysis of thyroid tissue specimens, and identified nine proteins that could potentially distinguish FA and FTC.

Validation and comparison of three newly-released Thyroid Imaging Reporting and Data Systems for cancer risk determination.

PURPOSE: To validate and compare diagnostic value of three newly-released Thyroid Imaging Reporting and Data Systems (TIRADS) for cancer risk determination. METHODS: Total 2031 patients with 2465 thyroid nodules were recruited for this study. Ultrasound (US) images were categorized based on three TIRADS editions established by Korean Society of Thyroid Radiology (KSThR), European Thyroid Association (ETA) and American College of Radiology (ACR). ROC curves were established to compare diagnostic value. RESULTS: Total 1460 benign and 1005 malignant nodules were enrolled. The malignancy rates of each category in KSThR-TIRADS were 2.8%, 5.1%, 33.7% and 79.6%, respectively. For European-TIRADS, 0, 3.1, 22.8, and 73.5% of nodules categorized as 2 to 5 were malignant. Distribution of carcinomas among ACR-TIRADS categories was 0%, 2.3%, 7.5%, 40.1% and 81.4%, respectively. In terms of diagnostic value, KSThR-TIRADS had highest AUC (0.855) and specificity (87.4%), while lowest (71.4%) sensitivity. ACR-TIRADS showed best sensitivity (96.6%) with lowest specificity (52.9%) and the AUC (0.846) was slightly lower than KSThR-TIRADS. Total 56.1, 45.4, and 37.4% fine-needle aspiration biopsy (FNAB) were recommended by KSThR, ETA and ACR, revealing 42.8%, 44.5% and 53.6% malignant lesions, respectively. The rate of unnecessary FNAB was lowest with the ACR (17.3%), followed by ETA (25.2%) and KSThR (32.1%). CONCLUSION: All these US models showed great value in predicting thyroid malignancy. Among them, KSThR-TIRADS showed the most effective diagnostic performance in specificity, while ACR-TIRADS yielded best sensitivity. As for FNAB criteria, ACR-TIRADS showed the lowest rate of unnecessary FNAB and highest rate of malignancy in FNAB.