LINC00921 reduces lung cancer radiosensitivity by destabilizing NUDT21 and driving aberrant MED23 alternative polyadenylation

NUDT21 lactylation reprograms alternative polyadenylation to promote cuproptosis resistance

Alternative polyadenylation (APA) is critical for shaping transcriptome diversity and modulating cancer therapeutic resistance. While lactate is a well-established metabolic signal in cancer progression, its role in APA regulation remains unclear. Here, we demonstrate that L-lactate-induced lactylation of NUDT21 drives transcriptomic reprogramming through APA modulation. NUDT21 lactylation enhances its interaction with CPSF6, facilitating CFIm complex formation and inducing 3' untranslated region (UTR) lengthening of FDX1. Extension of the FDX1 3' UTR attenuates its protein output, thereby conferring resistance to cuproptosis in esophageal squamous cell carcinoma (ESCC). Furthermore, we identify AARS1 as the lactylation "writer" catalyzing NUDT21 K23 lactylation, and HDAC2 as its enzymatic "eraser". Clinically, elevated levels of both LDHA and NUDT21, as well as increased K23-lactylated NUDT21, are associated with reduced FDX1 expression and worse prognosis in ESCC patients. Notably, combined targeting of the lactate-NUDT21-FDX1-cuproptosis axis with the clinical LDHA inhibitor stiripentol and the copper ionophore elesclomol synergistically suppressed tumor growth. Collectively, our work identifies lactylated NUDT21 as a critical factor linking cellular metabolism to APA and proposes a promising therapeutic strategy for ESCC treatment.

WDR11-DT enhances radiosensitivity via promoting PARP1 degradation and homologous recombination deficiency

Radiotherapy is an important management for non-small cell lung cancer (NSCLC). Although long non-coding RNAs (lncRNAs) have been reported to be involved in modulating radiosensitivity, the underlying mechanisms are still largely unclear. Here, we found that tumor suppressor WDR11-DT is a novel radiation-induced lncRNA, which is transcriptionally regulated by SPDEF, in NSCLC. In contrast to normal tissues, WDR11-DT is down-regulated in NSCLC specimens and its low expression was associated with poor prognosis of patient receiving radiotherapy. Importantly, WDR11-DT can markedly enhance NSCLC cells' radiosensitivity in vitro and in vivo. WDR11-DT functions through distinct mechanisms via binding different proteins. WDR11-DT facilitates interactions between PARP1 and its E3 ligase TRIP12, promotes PARP1 protein degradation and suppresses PARP1-controlled Single-strand breaks (SSBs) repair. Additionally, WDR11-DT binds RNA-bind protein HNRNPK, represses its functions in improving RNA stability of homologous recombination (HR) genes, decreases expression of BRCA1, ATM, BLM and RAD50, and suppresses radiotherapy-triggered HR repair. WDR11-DT-induced dual restraints of PARP1 and the HR pathway lead to the accumulation of double-strand breaks as well as synthetic lethal effects of malignant cells, which, thereby, enhances radiosensitivity and inhibits progression of lung cancer. These results extend our current knowledge of radio-biology and elucidate that WDR11-DT may be a new target for boosting cancer radiotherapy.

IGF2BP3 recruits NUDT21 to regulate SPTBN1 alternative polyadenylation and drive ovarian cancer progression

Ovarian cancer (OC) is one of the deadliest gynecological malignancies. As the prevalent post-transcriptional regulation, alternative polyadenylation (APA) plays a crucial role in various tumors. Here we identify that the APA regulator NUDT21 is upregulated in OC and promotes malignant progression. We further demonstrate that IGF2BP3 interacts with NUDT21, which suggests m6A modification could regulate APA processing. Mechanistically, IGF2BP3, recognizing the m6A-modified site in intron 32 of SPTBN1, recruits NUDT21 to promote the usage of the SPTBN1 proximal polyadenylation site (PAS), thus increasing the generation of short transcripts in OC cells. Intriguingly, the SPTBN1 long variant demonstrates tumor-suppressive properties, whereas the short variant enhances oncogenic activity in OC. Subsequently, we illustrate that the long isoform inhibits tumor growth and metastasis by binding to CDK1 and blocking the G2/M phase of the cell cycle. In conclusion, this study uncovers a previously unrecognized regulatory mechanism in OC, which could provide potential therapeutic strategies for OC.

Multi-omics analysis unveils a four-gene prognostic signature in esophageal squamous carcinoma and the therapeutic potential of PKP1

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies, characterized by high heterogeneity and poor outcomes. Effective classification for patient stratification and identifying reliable markers for prognosis prediction and treatment choice are crucial.

METHODS

Integration of single-cell RNA-sequencing (RNA-seq) and bulk RNA-seq analyses were used to characterize ESCC. Non-negative matrix factorization (NMF) clustering was performed to stratify the ESCC patients into different subtypes and the clinical and pathological features of the ESCC subtypes were compared. Cox regression analysis and LASSO regression analysis were used to select key genes and construct a risk model for ESCC. The associations of the key genes with anti-cancer drug sensitivities in ESCC cell lines were investigated. RT-qRCR experiments, proteomics analysis, and multiplex immunohistochemistry (mIHC) experiments were used to validate the results. Furthermore, one identified gene was selected to investigate its correlation with EGFR expression and the gene effect scores of various potential gene targets across pan-cancer.

RESULTS

The study identified the dysregulated distributions of epithelial cells and fibroblasts as characteristic of ESCC. ESCC patients could be classified into four distinct subtypes with unique cell type features and prognoses. With the gene makers of the cell type features, a four-gene prognostic signature for ESCC was constructed. The CCND1-PKP1-JUP-ANKRD12 model could effectively discriminate the survival status of ESCC patients, independent of various pathological and clinical features. The risk score for the samples was correlated with the expression levels of immunoregulatory genes. The prognostic effects of CCND1, PKP1, and JUP were confirmed at the protein level. The phosphorylation levels of PKP1, JUP, and ANKRD12 were found to be dysregulated in ESCC tumors. Their expression dysregulation and heterogeneity were demonstrated in ESCC cell lines. All four genes were significantly correlated with at least one of the anti-cancer drug sensitivities in ESCC cell lines. PKP1 expression was significantly correlated with EGFR expression and gene effect scores in multiple cancers.

CONCLUSIONS

We conclude that the CCND1-PKP1-JUP-ANKRD12 signature may serve as a novel indicator for ESCC prognosis and diagnosis. PKP1 expression might provide new clues for gene therapy efficacy in multiple cancers.

NAT10 promotes radiotherapy resistance in non-small cell lung cancer by regulating KPNB1-mediated PD-L1 nuclear translocation

Radiotherapy (RT) resistance in non-small cell lung cancer (NSCLC) is a significant contributor to tumor recurrence. NAT10, an enzyme that catalyzes ac4C RNA modification, has an unclear role in RT resistance. This study aimed to explore the function of NAT10 in RT resistance in NSCLC. RT-resistant NSCLC cell lines (PC9R and A549R) were established through repeated irradiation. The impact of NAT10 on cellular immunity was evaluated by measuring immune cell populations, cytotoxicity levels, and markers of cell dysfunction. Results demonstrated elevated levels of ac4C and NAT10 in RT-resistant cells. Knockdown of NAT10 suppressed cell proliferation and enhanced immune function in PC9R and A549R cells by upregulating TNF-α and IFN-γ while downregulating PD-1 and TIM-3. Mechanistically, RT resistance in NSCLC was mediated by NAT10-dependent ac4C modification of KPNB1. Furthermore, KPNB1 facilitated PD-L1 nuclear translocation, promoting immune escape in RT-resistant NSCLC cells. Overexpression of KPNB1 enhanced cell proliferation but impaired immune function in RT-resistant NSCLC cells. In conclusion, this study demonstrates that NAT10 upregulates KPNB1 expression through ac4C modification, thereby promoting RT resistance in NSCLC via PD-L1 nuclear translocation. These findings reveal a novel mechanism underlying RT resistance in NSCLC.

The alternative polyadenylation regulator CFIm25 promotes macrophage differentiation and activates the NF-κB pathway

BACKGROUND

Macrophages are required for development and tissue repair and protect against microbial attacks. In response to external signals, monocytes differentiate into macrophages, but our knowledge of changes that promote this transition at the level of mRNA processing, in particular mRNA polyadenylation, needs advancement if it is to inform new disease treatments. Here, we identify CFIm25, a well-documented regulator of poly(A) site choice, as a novel mediator of macrophage differentiation.

METHODS

CFIm25 expression was analyzed in differentiating primary human monocytes and monocytic cell lines. Overexpression and depletion experiments were performed to assess CFIm25's role in differentiation, NF-κB signaling, and alternative polyadenylation (APA). mRNA 3' end-focused sequencing was conducted to identify changes in poly(A) site use of genes involved in macrophage differentiation and function. Cell cycle markers, NF-κB pathway components, and their targets were examined. The role of CFIm25 in NF-κB signaling was further evaluated through chemical inhibition and knockdown of pathway regulators.

RESULTS

CFIm25 showed a striking increase upon macrophage differentiation, suggesting it promotes this process. Indeed, CFIm25 overexpression during differentiation amplified the acquisition of macrophage characteristics and caused an earlier slowing of the cell cycle, a hallmark of this transition, along with APA-mediated downregulation of cyclin D1. The NF-κB signaling pathway plays a major role in maturation of monocytes to macrophages, and the mRNAs of null, TBL1XR1, and NFKB1, all positive regulators of NF-κB signaling, underwent 3'UTR shortening, coupled with an increase in the corresponding proteins. CFIm25 overexpression also elevated phosphorylation of the NF-κB-p65 transcription activator, produced an earlier increase in the NF-κB targets p21, Bcl-XL, ICAM1 and TNF-α, and resulted in greater resistance to NF-κB chemical inhibition. Knockdown of Tables 2 and TBL1XR1 in CFIm25-overexpressing cells attenuated these effects, reinforcing the mechanistic link between CFIm25-regulated APA and NF-κB activation. Conversely, depletion of CFIm25 hindered differentiation and led to lengthening of NFKB1, TAB2, and TBL1XR1 3' UTRs.

CONCLUSIONS

Our study establishes CFIm25 as a key mediator of macrophage differentiation that operates through a coordinated control of cell cycle progression and NF-κB signaling. This linkage of mRNA processing and immune cell function also expands our understanding of the role of alternative polyadenylation in regulating cell signaling.

Pyroptosis in lung cancer: The emerging role of non-coding RNAs

Lung cancer remains an intractable malignancy worldwide, prompting novel therapeutic modalities. Pyroptosis, a lethal form of programmed cell death featured by inflammation, has been involved in cancer progression and treatment response. Simultaneously, non-coding RNA has been shown to have important roles in coordinating pattern formation and oncogenic pathways, including long non-coding RNA (lncRNAs), microRNA (miRNAs), circular RNA (circRNAs), and small interfering RNA (siRNAs). Recent studies have revealed that ncRNAs can promote or inhibit pyroptosis by interacting with key molecular players such as NLRP3, GSDMD, and various transcription factors. This dual role of ncRNAs offers a unique therapeutic potential to manipulate pyroptosis pathways, providing opportunities for innovative cancer treatments. In this review, we integrate current research findings to propose novel strategies for leveraging ncRNA-mediated pyroptosis as a therapeutic intervention in lung cancer. We explore the potential of ncRNAs as biomarkers for predicting patient response to treatment and as targets for overcoming resistance to conventional therapies.

MAZ promotes thyroid cancer progression by driving transcriptional reprogram and enhancing ERK1/2 activation

Papillary thyroid carcinoma (PTC) is the most common type of thyroid malignancies worldwide. Oncogenic transcription factors (TFs) drive transcriptional reprogramming and tumorigenesis. The myc-associated zinc finger protein (MAZ) is one of the Myc family TFs. The role of MAZ in PTC pathogenesis is still largely unknown. Here, we report that MAZ profoundly promotes proliferation of PTC cells ex vivo and in vivo through activating MAPK signaling. We firstly profiled gene expression of PTC cells after silencing of MAZ. BRAF, KRAS and LOC547 were identified as important target genes of TF MAZ. In particular, TF MAZ bound to the promoters of BRAF or KRAS and significantly increased their transcription and expression levels. Meanwhile, MAZ could noticeably elevate LOC547 transcription and expression as a TF. High levels of LOC547 relocated ACTN4 protein from the nucleus to the cytosol, improved protein-protein interactions between ACTN4 and EGFR in the cytosol, enhanced ERK1/2 phosphorylation, activated the MAPK signaling and, thus, promoted PTC progression. Our data identify a previously underappreciated MAZ-controlled transcriptional reprogram and ERK1/2 activation via BRAF, KRAS and LOC547. Our data illustrate that activation of the MAZ-controlled axis promotes thyroid tumorigenesis. These insights would advance our knowledge of the role of TFs in cancer development and highlight the potential of TFs as future targets for treatments against cancers.