SNORA73B promotes endometrial cancer progression through targeting MIB1 and regulating host gene RCC1 alternative splicing

miR-1264 Exacerbates Proliferation, Migration and Invasion of Endometrial Cancer Cells by Targeting MSH2

Accumulating studies have revealed that microRNAs serve significant regulatory for endometrial carcinoma (EC) tumorigenesis and progression. The specific objective of this investigation is to seek the potential function of miR-1264 in EC and clarified the underlying mechanism. Determination of miR-1264 and MSH2 expression in EC tissues or cell lines was performed by RT-qPCR and/or western blot assay. The malignant behaviors of EC cells were verified by CCK-8 assay, EdU staining, wound healing assay and Transwell assay, respectively. Besides, the interaction between miR-1264 and MSH2 was verified by dual-luciferase reporter assay and RNA immunoprecipitation assay. MiR-1264 exhibited high levels in EC tissues and has been found to be correlated with a poor prognosis in EC patients. Functionally, silencing miR-1264 resulted in inhibiting the aggressiveness behaviors of HEC-1 A and KLE cells, while forced miR-1264 expression executed opposite effects. Mechanistically, miR-1264 directly targeted and suppressed MSH2 expression. Functional rescue experiments further validated that overexpression of MSH2 diminished malignant behaviors of EC cells and greatly reversed the promoting effects of miR-1264 on the malignant behaviors of EC cells. MiR-1264 acted as an oncogene in EC, promoting aggressiveness behaviors of EC cells by inhibiting MSH2. This study provided novel insights into anti-cancer treatment and a theoretical basis for potential therapeutic targets of EC.

The potential impact of RNA splicing abnormalities on immune regulation in endometrial cancer

RNA splicing controls the post-transcriptional level of gene expression, allowing for the synthesis of many transcripts with various configurations and roles. Variations in RNA splicing regulatory factors, including splicing factors, signaling pathways, epigenetic modifications, and environmental factors, are typically the origin of tumor-associated splicing anomalies. Furthermore, thorough literature assessments on the intricate connection between tumor-related splicing dysregulation and tumor immunity are currently lacking. Therefore, we also thoroughly discuss putative targets associated with RNA splicing in endometrial cancer (EC) and the possible impacts of aberrant RNA splicing on the immune control of tumor cells and tumor microenvironment (TME), which contributes to enhancing the utilization of immunotherapy in the management of EC and offers an alternative viewpoint for the exploration of cancer therapies and plausible prognostic indicators.

Targeting the splicing factor SNRPB inhibits endometrial cancer progression by retaining the POLD1 intron

Dysregulated alternative splicing has been closely linked to the initiation and progression of tumors. Nevertheless, the precise molecular mechanisms through which splicing factors regulate endometrial cancer progression are still not fully understood. This study demonstrated elevated expression of the splicing factor SNRPB in endometrial cancer samples. Furthermore, our findings indicate that high SNRPB expression is correlated with poor prognosis in patients with endometrial cancer. Functionally, SNRPB inhibition hindered the proliferative and metastatic capacities of endometrial cancer cells. Mechanistically, we revealed that SNRPB knockdown decreased POLD1 expression and that POLD1 intron 22 was retained after SNRPB silencing in endometrial cancer cells, as determined via RNA sequencing data analysis. The retained intron 22 of POLD1 created a premature termination codon, leading to the absence of amino acids 941-1,107 and the loss of the site of interaction with PCNA, which is essential for POLD1 enzyme activity. In addition, POLD1 depletion decreased the increase in the malignancy of endometrial cancer cells overexpressing SNRPB. Furthermore, miR-654-5p was found to bind directly to the 3' untranslated region of SNRPB, resulting in SNRPB expression inhibition in endometrial cancer. Antisense oligonucleotide-mediated SNRPB inhibition led to a decrease in the growth capacity of a cell-derived xenograft model and a patient with endometrial cancer-derived xenograft model. Overall, SNRPB promotes the efficient splicing of POLD1 by regulating intron retention, ultimately contributing to high POLD1 expression in endometrial cancer. The oncogenic SNRPB-POLD1 axis is an interesting therapeutic target for endometrial cancer, and antisense oligonucleotide-mediated silencing of SNRPB may constitute a promising therapeutic approach for treating patients with endometrial cancer.

SnoRNAs: The promising targets for anti-tumor therapy

Recently, small nucleolar RNAs (snoRNAs) have transcended the genomic "noise" to emerge as pivotal molecular markers due to their essential roles in tumor progression. Substantial evidence indicates a strong association between snoRNAs and critical clinical features such as tumor pathology and drug resistance. Historically, snoRNA research has concentrated on two classical mechanisms: 2'-O-ribose methylation and pseudouridylation. This review specifically summarizes the novel regulatory mechanisms and functional patterns of snoRNAs in tumors, encompassing transcriptional, post-transcriptional, and post-translational regulation. We further discuss the synergistic effect between snoRNA host genes (SNHGs) and snoRNAs in tumor progression. More importantly, snoRNAs extensively contribute to the development of tumor cell resistance as oncogenes or tumor suppressor genes. Accordingly, we provide a comprehensive review of the clinical diagnosis and treatment associated with snoRNAs and explore their significant potential as novel drug targets.

RCC1 regulation of subcellular protein localization via Ran GTPase drives pancreatic ductal adenocarcinoma growth

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy, with limited therapeutic options. Here, we evaluated the role of regulator of chromosome condensation 1 (RCC1) in PDAC. RCC1 functions as a guanine exchange factor for GTP-binding nuclear protein Ran (Ran) GTPase and is involved in nucleocytoplasmic transport. RCC1 RNA expression is elevated in PDAC tissues compared to normal pancreatic tissues and correlates with poor prognosis. RCC1 silencing by RNAi and CRISPR-Cas9 knockout (KO) results in reduced proliferation in 2-D and 3-D cell cultures. RCC1 knockdown (KD) reduced migration and clonogenicity, enhanced apoptosis, and altered cell cycle progression in human PDAC and murine cells from LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre (KPC) tumors. Mechanistically, RCC1 KO shows widespread transcriptomic alterations including regulation of PTK7, a co-receptor of the Wnt signaling pathway. RCC1 KD disrupted subcellular Ran localization and the Ran gradient. Nuclear and cytosolic proteomics revealed altered subcellular proteome localization in Rcc1 KD KPC-tumor-derived cells and several altered metabolic biosynthesis pathways. In vivo, RCC1 KO cells show reduced tumor growth potential when injected as sub-cutaneous xenografts. Finally, RCC1 KD sensitized PDAC cells to gemcitabine chemotherapy treatment. This study reveals the role of RCC1 in pancreatic cancer as a novel molecular vulnerability that could be exploited to enhance therapeutic response.

Identification of four snoRNAs (SNORD16, SNORA73B, SCARNA4, and SNORD49B) as novel non-invasive biomarkers for diagnosis of breast cancer

BACKGROUND

Emerging data point to the critical role of snoRNA in the emergence of different types of cancer, but scarcely in breast cancer (BC). This study aimed to clarify the differential expressions and potential diagnostic value of SNORD16, SNORA73B, SCARNA4, and SNORD49B in BC.

METHODS

We screened differential snoRNAs in BC tissues and adjacent tissues through SNORic datasets, and then we further verified them in the plasma of BC patients and healthy volunteers by quantitative polymerase chain reaction (qPCR).

RESULTS

These four snoRNAs: SNORD16, SNORA73B, SCARNA4, and SNORD49B were considerably more abundant in cancerous tissues than in neighboring tissues in the TCGA database. Their plasma levels were also higher in BC and early-stage BC patients when compared to healthy controls. Furthermore, the ROC curve demonstrated that BC (AUC = 0.7521) and early-stage BC (AUC = 0.7305) might be successfully distinguished from healthy people by SNORD16, SNORA73B, SCARNA4, and SNORD49B.

CONCLUSION

Plasma snoRNAs: SNORD16, SNORA73B, SCARNA4, and SNORD49B were upregulated in BC and early-stage BC and can be used as potential diagnostic markers for BC and early-stage BC.