Xiaobo Cui

Epigenetic dysregulation, particularly N6-methyladenosine (m6A) modification, drives hepatocellular carcinoma (HCC) progression, yet the oncogenic role of the m6A reader IGF2BP3 remains incompletely understood. This study aimed to elucidate the functional contributions and molecular mechanisms of IGF2BP3 in HCC. Multi-omics databases and tissue microarrays were employed to evaluate IGF2BP3 and PLK1 expression, clinicopathological associations, and prognostic value via Kaplan–Meier, Cox regression, and ROC analyses. Molecular interactions were probed by RIP, luciferase reporter, MeRIP, dot blot, and actinomycin D assays. In vitro gain/loss-of-function experiments measured glycolytic metabolites, extracellular acidification rate (ECAR), oxygen consumption rate (OCR), mitochondrial mass/charge, ROS, and key proteins of glycolysis and oxidative phosphorylation (OXPHOS). Both IGF2BP3 and PLK1 were significantly upregulated in HCC versus adjacent non-tumor tissues, correlating positively with advanced clinical stage, higher tumor grade, and poorer overall survival. In the TCGA-LIHC discovery cohort, each showed an independent prognostic association with unfavorable outcomes after adjustment for established clinical covariates. PLK1 mRNA was validated to carry m6A modifications and directly bind IGF2BP3, an interaction abolished by cycloleucine. Functionally, IGF2BP3 upregulated m6A-modified PLK1 by enhancing its mRNA stability, leading to elevated HK2 expression, increased glucose-6-phosphate and lactate levels, and enhanced ECAR, while suppressing mitochondrial respiratory chain complexes, ROS production, and OCR. In conclusion, IGF2BP3 is overexpressed in HCC and tightly associated with aggressive clinicopathological features and adverse outcomes. Altogether, these findings suggest that IGF2BP3 may enhance the stability of the m6A-modified PLK1 transcript, orchestrating a metabolic rewiring from oxidative phosphorylation to glycolysis, revealing a potential IGF2BP3–m6A–PLK1 axis driving HCC aggressiveness and offering potential therapeutic targets for precision intervention.

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by pathogenic variants in the FBN1 gene. Using whole‐exome sequencing (WES) in a Chinese MFS family, we identified a novel heterozygous nonsense variant FBN1 :c.1415dup;p.(Tyr472Ter), which cosegregates with the disease phenotype and results in protein truncation. Immunohistochemical analysis confirmed markedly reduced fibrillin‐1 expression in the aortic wall of variant carriers, and this variant was classified as pathogenic. Unexpectedly, the proband’s younger sister harbors three independent pathogenic variants responsible for MFS, familial hypercholesterolemia (FH), and oculopharyngeal muscular dystrophy (OPMD). Further transcript validation and functional assays demonstrated that the LDLR :c.1987+1G > A;p.Arg662_Gly663insAspLys splice‐site mutation generates a stable in‐frame insertion transcript, impairing protein structure and function. Supported by robust functional evidence and familial cosegregation, this LDLR variant was upgraded from a variant of uncertain significance to pathogenic. We provided formal genetic counseling, long‐term clinical follow‐up, and multidisciplinary surveillance to all affected family members, with particularly comprehensive management for the proband’s sister. This study expands the mutational spectrum of FBN1 , establishes functional evidence for the pathogenicity of the LDLR variant, and represents the first report of a pediatric individual carrying three coexisting pathogenic variants for rare diseases. Our findings provide critical insights for molecular diagnosis, genetic counseling, and clinical risk stratification in affected families.

Hepatocellular carcinoma (HCC) remains a leading cause of cancer-related mortality globally. While m6A regulators are implicated in cancer progression, the role of single nucleotide polymorphisms (SNPs) in m6A regulator genes in HCC susceptibility remains underexplored. Here, we evaluated 31 candidate SNPs across eight dysregulated m6A regulator genes in a case–control study comprising 800 HCC patients and 800 healthy controls from Northeast China. Genotyping revealed three SNPs significantly associated with elevated HCC risk: rs2736158 C allele (PRRC2A; adjusted odds ratio [OR] = 1.295, 95% [CI] = 1.039–1.615, p = 0.021), rs9366785 A allele (PRRC2A; adjusted odds ratio [OR] = 1.312, 95% [CI] = 1.011–1.704, p = 0.041), and rs274054 C allele (IGF2BP3; adjusted odds ratio [OR] = 1.224, 95% [CI] = 1.040–1.440, p = 0.015). Comparison of genotype frequency of three SNPs under given genetic models further linked rs274054 CC (IGF2BP3), rs2736158 CC (PRRC2A), and rs9366785 AA + AG (PRRC2A) genotypes to higher HCC risk. Subgroup analyses identified associations between specific genotypes (e.g., rs9906944 TT/TC in IGF2BP1) and adverse clinicopathological features, including vascular invasion and liver cirrhosis. Haplotype analysis highlighted the CACA haplotype (PRRC2A: rs280801, rs2736171, rs2736158, rs2736157) as a high-susceptibility marker (adjusted odds ratio [OR] = 1.297, 95% [CI] = 1.041–1.616, p = 0.020). Our findings suggest that m6A regulator SNPs contribute to HCC susceptibility and progression, offering insights into genetic biomarkers for risk stratification in Northeast Chinese populations.

DNA methylation prominently inactivates tumor suppressor genes and facilitates oncogenesis. Previously, we delineated a chromosome 18 deletion encompassing the erythrocyte membrane protein band 4.1-like 3 (EPB41L3) gene, a progenitor for the tumor suppressor that is differentially expressed in adenocarcinoma of the lung-1 (DAL-1) in gastric cancer (GC). Our current investigation aimed to elucidate EPB41L3 expression and methylation in GC, identify regulatory transcription factors, and identify affected downstream pathways. Immunohistochemistry demonstrated that DAL-1 expression is markedly reduced in GC tissues, with its downregulation serving as an independent prognostic marker. High-throughput bisulfite sequencing of 70 GC patient tissue pairs revealed that higher methylation of non-CpGs in the EPB41L3 promoter was correlated with more malignant tumor progression and higher-grade tissue classification. Such hypermethylation was shown to diminish DAL-1 expression, thus contributing to the malignancy of GC phenotypes. The DNA methyltransferase inhibitor 5-aza-2’-deoxycytidine (5-aza-CdR) was found to partially restore DAL-1 expression. Moreover, direct binding of the transcription factor CDC5L to the upstream region of the EPB41L3 promoter was identified via chromosome immunoprecipitation (ChIP)-qPCR and luciferase reporter assays. Immunohistochemistry confirmed the positive correlation between CDC5L and DAL-1 protein levels. Subsequent RNA-seq analysis revealed that DAL-1 significantly influences the extracellular matrix and space-related pathways. GC cell RNA-seq post-5-Aza-CdR treatment and single-cell RNA-seq data of GC tissues confirmed the upregulation of AREG and COL17A1, pivotal tumor suppressors, in response to EPB41L3 demethylation or overexpression in GC epithelial cells. In conclusion, this study elucidates the association between non-CpG methylation of EPB41L3 and GC progression and identifies the key transcription factors and downstream molecules involved. These findings enhance our understanding of the role of EPB41L3 in gastric cancer and provide a solid theoretical foundation for future research and potential clinical applications. The EPB41L3 gene, frequently exhibiting haplotype deletions and reduced expression in gastric cancer tissues, points to its potential role as a tumor suppressor. However, tumor suppressor genes are not only influenced by genomic deletions but also by their methylation status. Our study highlights the significantly lower expression of EPB41L3 in gastric cancer compared to adjacent non-cancerous tissues across 262 patients. We also discovered that elevated non-CpG island methylation of EPB41L3 correlates strongly with tumor malignancy progression, based on the analysis of 70 paired gastric cancer samples. Moreover, we identified CDC5L as a crucial transcription factor interacting with the EPB41L3 promoter. Integrative analyses of transcriptomic and single-cell sequencing data further revealed that AREG and COL17A1 are key downstream molecules regulated by DAL-1, with their expression tightly controlled by EPB41L3 methylation and expression levels. These insights enhance our understanding of EPB41L3’s role in gastric cancer and could open new avenues for targeted therapies.

The locus at 17q12 erb‐b2 receptor tyrosine kinase 2 (ERBB2) has been heavily amplificated and overexpressed in gastric cancer (GC), but it remains to be elucidated about the clinical significance of the co‐amplification and co‐overexpression of PGAP3 gene located around ERBB2 in GC. The profile of PGAP3 and ERBB2 in four GC cell lines and tissue microarrays containing 418 primary GC tissues was assessed to investigate the co‐overexpression and clinical significance of the co‐amplified genes, and to evaluate the impact of the co‐amplified genes on the malignancy of GC. Co‐amplification of PGAP3 and ERBB2 accompanied with co‐overexpression was observed in a haploid chromosome 17 of NCI‐N87 cells with double minutes (DMs). PGAP3 and ERBB2 were overexpressed and positively correlated in 418 GC patients. Co‐overexpression of the PGAP3 and ERBB2 was correlated with T stage, TNM stage, tumour size, intestinal histological type and poor survival proportion in 141 GC patients. In vitro, knockdown of the endogenous PGAP3 or ERBB2 decreased cell proliferation and invasion, increased G1 phase accumulation and induced apoptosis in NCI‐N87 cells. Furthermore, combined silencing of PGAP3 and ERBB2 showed an additive effect on resisting proliferation of NCI‐N87 cells compared with targeting ERBB2 or PGAP3 alone. Taken together, the co‐overexpression of PGAP3 and ERBB2 may be crucial due to its significant correlation with clinicopathological factors of GC. Haploid gain of PGAP3 co‐amplified with ERBB2 is sufficient to facilitate the malignancy and progression of GC cells in a synergistic way.

Purpose: ZIP4 is overexpressed in human pancreatic cancer and promotes tumor growth. However, little is known about the role of ZIP4 in advanced stages of this dismal neoplasm. Our goal is to study the underlying mechanism and define a novel signaling pathway controlled by ZIP4-modulating pancreatic tumor metastasis.Experimental Design: The expression of ZIP4, ZO-1, claudin-1, and ZEB1 in human pancreatic cancer tissues, genetically engineered mouse model, xenograft tumor model, and pancreatic cancer cell lines were examined, and the correlations between ZIP4 and those markers were also analyzed. Functional analysis of ZO-1, claudin-1, and ZEB1 was investigated in pancreatic cancer cell lines and orthotopic xenografts.Results: Genetic inactivation of ZIP4 inhibited migration and invasion in pancreatic cancer and increased the expression of ZO-1 and claudin-1. Conversely, overexpression of ZIP4 promoted migration and invasion and increased the expression of ZEB1 and downregulation of the aforementioned epithelial genes. ZIP4 downregulation of ZO-1 and claudin-1 requires the transcriptional repressor ZEB1. Further analysis demonstrated that ZIP4-mediated repression of ZO-1 and claudin-1 leads to upregulation of their targets FAK and Paxillin. Silencing of ZIP4 caused reduced phosphorylation of FAK and Paxillin, which was rescued by simultaneous blocking of ZO-1 or claudin-1. Clinically, we demonstrated that ZIP4 positively correlates with the levels of ZEB1 and inversely associates with the expression of ZO-1 and claudin-1.Conclusions: These findings suggest a novel pathway activated by ZIP4-controlling pancreatic cancer invasiveness and metastasis, which could serve as a new therapeutic target for this devastating disease. Clin Cancer Res; 24(13); 3186–96. ©2018 AACR.

N6-methyladenosine (m⁶A) modifications control multifaceted RNA metabolism and are one of the most extensively distributed modifications on the human transcriptome, including non-coding RNAs (ncRNAs). Previous concepts of ncRNAs as “junk” transcriptional products have evolved to the concept that ncRNAs are functional regulatory molecules that determine specific biological processes and cell fates. The dysregulation of m⁶A modifications and ncRNAs have been implicated in the development of human carcinogenesis. Certain types of ncRNAs have been reported to exert regulatory effects on m⁶A machinery. However, a better understanding of the relationship between m⁶A modifications and ncRNAs in cancer is still needed. This review discusses mutual interactions between m⁶A modifications and ncRNAs and their impacts on the development of human cancer. We summarize the clinical significance of m⁶A-ncRNA networks for cancer diagnosis and treatment, and we ask challenging questions that remain unanswered in this field of research. Understanding the complex coordination between m⁶A modifications and ncRNAs will be useful for guiding the development of therapeutic interventions.

TSPAN12, a member of the tetraspanin family, has been highly connected with the pathogenesis of cancer. Its biological function, however, especially in ovarian cancer (OC), has not been well elucidated. In this study, The Cancer Genome Atlas (TCGA) dataset analysis revealed that upregulation of TSPAN12 gene expression was significantly correlated with patient survival, suggesting that TSPAN12 might be a potential prognostic marker for OC. Further exploration showed that TSPAN12 overexpression accelerated proliferation and colony formation of OVCAR3 and SKOV3 OC cells. Knockdown of TSPAN12 expression in A2780 and SKOV3 cells decreased both proliferation and colony formation. Western blot analysis showed that several cyclins and cyclin-dependent kinases (CDK) (e.g., Cyclin A2, Cyclin D1, Cyclin E2, CDK2, and CDK4) were significantly involved in the regulation of cell cycle downstream of TSPAN12. Moreover, TSPAN12 accelerated mitotic progression by controlling cell cycle. Thus, our data demonstrated that TSPAN12 could be a novel molecular target for the treatment of OC.