Disruption of PABPN1 phase separation by SNRPD2 drives colorectal cancer cell proliferation and migration through promoting alternative polyadenylation of CTNNBIP1.

Generally shortened 3' UTR due to alternative polyadenylation (APA) is widely observed in cancer, but its regulation mechanisms for cancer are not well characterized. Here, with profiling of APA in colorectal cancer tissues and poly(A) signal editing, we firstly identified that the shortened 3' UTR of CTNNIBP1 in colorectal cancer promotes cell proliferation and migration. We found that liquid-liquid phase separation (LLPS) of PABPN1 is reduced albeit with higher expression in cancer, and the reduction of LLPS leads to the shortened 3' UTR of CTNNBIP1 and promotes cell proliferation and migration. Notably, the splicing factor SNRPD2 upregulated in colorectal cancer, can interact with glutamic-proline (EP) domain of PABPN1, and then disrupt LLPS of PABPN1, which attenuates the repression effect of PABPN1 on the proximal poly(A) sites. Our results firstly reveal a new regulation mechanism of APA by disruption of LLPS of PABPN1, suggesting that regulation of APA by interfering LLPS of 3' end processing factor may have the potential as a new way for the treatment of cancer.

CPSF6 regulates alternative polyadenylation and proliferation of cancer cells through phase separation.

Cancer cells usually exhibit shortened 3' untranslated regions (UTRs) due to alternative polyadenylation (APA) to promote cell proliferation and migration. Upregulated CPSF6 leads to a systematic prolongation of 3' UTRs, but CPSF6 expression in tumors is typically higher than that in healthy tissues. This contradictory observation suggests that it is necessary to investigate the underlying mechanism by which CPSF6 regulates APA switching in cancer. Here, we find that CPSF6 can undergo liquid-liquid phase separation (LLPS), and elevated LLPS is associated with the preferential usage of the distal poly(A) sites. CLK2, a kinase upregulated in cancer cells, destructs CPSF6 LLPS by phosphorylating its arginine/serine-like domain. The reduction of CPSF6 LLPS can lead to a shortened 3' UTR of cell-cycle-related genes and accelerate cell proliferation. These results suggest that CPSF6 LLPS, rather than its expression level, may be responsible for APA regulation in cancer cells.

Regulation of m6A modification on ferroptosis and its potential significance in radiosensitization.

Radiotherapy is often used to treat various types of cancers, but radioresistance greatly limits the clinical efficiency. Recent studies have shown that radiotherapy can lead to ferroptotic cancer cell deaths. Ferroptosis is a new type of programmed cell death caused by excessive lipid peroxidation. The induction of ferroptosis provides a potential therapeutic strategy for radioresistance. As the most common post-transcriptional modification of mRNA, m6A methylation is widely involved in the regulation of various physiopathological processes by regulating RNA function. Dynamic m6A modification controlled by m6A regulatory factors also affects the susceptibility of cells to ferroptosis, thereby determining the radiosensitivity of tumor cells to radiotherapy. In this review, we summarize the mechanism and significance of radiotherapy induced ferroptosis, analyze the regulatory characteristics of m6A modification on ferroptosis, and discuss the possibility of radiosensitization by enhancing m6A-mediated ferroptosis. Clarifying the regulation of m6A modification on ferroptosis and its significance in the response of tumor cells to radiotherapy will help us identify novel targets to improve the efficacy of radiotherapy and reduce or overcome radioresistance.

GPX8 deficiency-induced oxidative stress reprogrammed m6A epitranscriptome of oral cancer cells.

Glutathione peroxidase 8 (GPX8) is a key regulator of redox homoeostasis. Whether its antioxidant activity participates in the regulation of m6A modification is a crucial issue, which has important application value in cancer treatment. In this study, MeRIP-seq was used to explore the characteristics of transcriptome-wide m6A modification in GPX8-deficient oral cancer cells. Oxidative stress caused by the lack of GPX8 resulted in 1,279 hyper- and 2,287 hypo-methylated m6A peaks and 2,036 differentially expressed genes in GPX8-KO cells. Twenty-eight differentially expressed genes were related to the cell response to oxidative stress, and half of them changed their m6A modification. In GPX8-KO cells, m6A regulators IGF2BP2 and IGF2BP3 were upregulated, while FTO, RBM15, VIRMA, ZC3H13, and YTHDC2 were downregulated. After H2O2 treatment, the expression changes of RBM15, IGF2BP2, and IGF2BP3 were further enhanced. These data indicated that GPX8-mediated redox homoeostasis regulated m6A modification, thereby affecting the expression and function of downstream genes. This study highlights the possible significance of GPX8 and the corresponding m6A regulatory or regulated genes as novel targets for antioxidant intervention in cancer therapy.

Lack of GPX8 caused oxidative stress of oral cancer cells.Oxidative stress induced by GPX8 deficiency reprogrammed m⁶A epitranscriptome.GPX8 deletion­caused oxidative stress regulated expression of m⁶A regulatory genes.m⁶A modification of antioxidant genes is the adaptive response of cells to oxidative stress.

Transcriptome-wide m6A methylome analysis uncovered the changes of m6A modification in oral pre-malignant cells compared with normal oral epithelial cells.

As the most common post-transcriptional RNA modification, m6A methylation extensively regulates the structure and function of RNA. The dynamic and reversible modification of m6A is coordinated by m6A writers and erasers. m6A reader proteins recognize m6A modification on RNA, mediating different downstream biological functions. mRNA m6A modification and its corresponding regulators play an important role in cancers, but its characteristics in the precancerous stage are still unclear. In this study, we used oral precancerous DOK cells as a model to explore the characteristics of transcriptome-wide m6A modification and major m6A regulator expression in the precancerous stage compared with normal oral epithelial cell HOEC and oral cancer cell SCC-9 through MeRIP-seq and RT-PCR. Compared with HOEC cells, we found 1180 hyper-methylated and 1606 hypo-methylated m6A peaks and 354 differentially expressed mRNAs with differential m6A peaks in DOK cells. Although the change of m6A modification in DOK cells was less than that in SCC-9 cells, mRNAs with differential m6A in both cell lines were enriched into many identical GO terms and KEGG pathways. Among the 20 known m6A regulatory genes, FTO, ALKBH5, METTL3 and VIRMA were upregulated or downregulated in DOK cells, and the expression levels of 10 genes such as METTL14/16, FTO and IGF2BP2/3 were significantly changed in SCC-9 cells. Our data suggest that precancerous cells showed, to some extent, changes of m6A modification. Identifying some key m6A targets and corresponding regulators in precancerous stage may provide potential intervention targets for the prevention of cancer development through epigenetic modification in the future.

Nuclear m6 A reader YTHDC1 suppresses proximal alternative polyadenylation sites by interfering with the 3' processing machinery.

N6-methyladenosine (m6 A) and alternative polyadenylation (APA) are important regulators of gene expression in eukaryotes. Recently, it was found that m6 A is closely related to APA. However, the molecular mechanism of this new APA regulation remains elusive. Here, we show that YTHDC1, a nuclear m6 A reader, can suppress proximal APA sites and produce longer 3' UTR transcripts by binding to their upstream m6 A sites. YTHDC1 can directly interact with the 3' end processing factor FIP1L1 and interfere with its ability to recruit CPSF4. Binding to the m6 A sites can promote liquid-liquid phase separation of YTHDC1 and FIP1L1, which may play an important role in their interaction and APA regulation. Collectively, YTHDC1 as an m6 A "reader" links m6 A modification with pre-mRNA 3' end processing, providing a new mechanism for APA regulation.

APETALA2/ethylene responsive factor in fruit ripening: Roles, interactions and expression regulation.

Insects and animals are attracted to, and feed on ripe fruit, thereby promoting seed dispersal. As a vital vitamin and nutrient source, fruit make up an indispensable and enjoyable component of the human diet. Fruit ripening involves a series of physiological and biochemical changes in, among others, pigmentation, chlorophyll (Chl) degradation, texture, sugar accumulation, and flavor. Growing evidence indicates that the coordinated and ordered trait changes during fruit ripening depend on a complex regulatory network consisting of transcription factors, co-regulators, hormonal signals, and epigenetic modifications. As one of the predominant transcription factor families in plants and a downstream component of ethylene signaling, more and more studies are showing that APETALA2/ethylene responsive factor (AP2/ERF) family transcription factors act as critical regulators in fruit ripening. In this review, we focus on the regulatory mechanisms of AP2/ERFs in fruit ripening, and in particular the recent results on their target genes and co-regulators. We summarize and discuss the role of AP2/ERFs in the formation of key fruit-ripening attributes, the enactment of their regulatory mechanisms by interaction with other proteins, their role in the orchestration of phytohormone-signaling networks, and the epigenetic modifications associated with their gene expression. Our aim is to provide a multidimensional perspective on the regulatory mechanisms of AP2/ERFs in fruit ripening, and a reference for understanding and furthering research on the roles of AP2/ERF in fruit ripening.

Significance of Triple Detection of p16/ki-67 Dual-Staining, Liquid-Based Cytology and HR HPV Testing in Screening of Cervical Cancer: A Retrospective Study.

In addition to liquid-based cytology (LBC) and HR HPV testing, p16/ki-67 dual-staining is another method for cervical cancer screening. The combination of any two methods can improve the accuracy of screening, but some cervical lesions are still missed or misdiagnosed. In this retrospective study, the significance of LBC, HR HPV testing and especially p16/ki-67 dual-staining in cervical lesion screening was evaluated with reference to histological diagnosis. At the same time, we tried to explore the value of p16/ki-67 dual-staining combined with LBC and HR HPV testing (triple detection) in improving the diagnostic specificity of CIN2+ and reducing the missed diagnosis of CIN2+ lesions. We found that p16/ki-67 dual-staining was valuable in identifying cervical CIN2+ lesions and reducing the missed diagnosis of CIN2+ in HPV negative patients. More than 96% of CIN2+ patients were positive for two or three tests of triple detection. Whole positive triple detection can effectively predict high grade cervical lesions. In conclusion, the triple detection can distinguish almost all cervical CIN2+ lesions. Our data put forward and highlight the feasibility and significance of triple detection in cervical lesion screening.

The Differential Metabolic Response of Oral Squamous Cell Carcinoma Cells and Normal Oral Epithelial Cells to Cisplatin Exposure.

Metabolic reprogramming is one of the hallmarks of a tumor. It not only promotes the development and progression of tumor but also contributes to the resistance of tumor cells to chemotherapeutics. The difference in the metabolism between drug-resistant and sensitive tumor cells indicates that drug-resistant tumor cells have experienced metabolic adaptation. The metabolic response induced by chemotherapy is dynamic, but the early metabolic response of tumor cells to anticancer drugs and the effect of an initial response on the development of drug resistance have not been well studied. Early metabolic intervention may prevent or slow down the development of drug resistance. The differential metabolic responses of normal cells and tumor cells to drugs are unclear. The specific metabolites or metabolic pathways of tumor cells to chemotherapeutic drugs can be used as the target of metabolic intervention in tumor therapy. In this study, we used comparative metabolomics to analyze the differential metabolic responses of oral cancer cells and normal oral epithelial cells to short-term cisplatin exposure, and to identify the marker metabolites of early response in oral cancer cells. Oral cancer cells showed a dynamic metabolic response to cisplatin. Seven and five metabolites were identified as specific response markers to cisplatin exposure in oral cancer cell SCC-9 and normal oral epithelial cell HOEC, respectively. Glyoxylate and dicarboxylate metabolism and fructose, malate, serine, alanine, sorbose and glutamate were considered as specific enriched metabolic pathways and biomarkers of SCC-9 cells in response to cisplatin, respectively. The existence of differential metabolic responses lays a foundation for tumor chemotherapy combined with metabolic intervention.

Genome-Wide Characterization and Analysis of bHLH Transcription Factors Related to Anthocyanin Biosynthesis in Fig (Ficus carica L.).

The basic helix-loop-helix (bHLH) transcription factor family is the second largest transcription factor family in plants, and participates in various plant growth and development processes. A total of 118 bHLH genes were identified from fig (Ficus carica L.) by whole-genome database search. Phylogenetic analysis with Arabidopsis homologs divided them into 25 subfamilies. Most of the bHLHs in each subfamily shared a similar gene structure and conserved motifs. Seventy-two bHLHs were found expressed at fragments per kilobase per million mapped (FPKM) > 10 in the fig fruit; among them, 15 bHLHs from eight subfamilies had FPKM > 100 in at least one sample. bHLH subfamilies had different expression patterns in the female flower tissue and peel during fig fruit development. Comparing green and purple peel mutants, 13 bHLH genes had a significantly different (≥ 2-fold) expression. Light deprivation resulted in 68 significantly upregulated and 22 downregulated bHLH genes in the peel of the fruit. Sixteen bHLH genes in subfamily III were selected by three sets of transcriptomic data as candidate genes related to anthocyanin synthesis. Interaction network prediction and yeast two-hybrid screening verified the interaction between FcbHLH42 and anthocyanin synthesis-related genes. The transient expression of FcbHLH42 in tobacco led to an apparent anthocyanin accumulation. Our results confirm the first fig bHLH gene involved in fruit color development, laying the foundation for an in-depth functional study on other FcbHLH genes in fig fruit quality formation, and contributing to our understanding of the evolution of bHLH genes in other horticulturally important Ficus species.

Two Amphioxus ApeC-Containing Proteins Bind to Microbes and Inhibit the TRAF6 Pathway.

The apextrin C-terminal (ApeC) domain is a class of newly discovered protein domains with an origin dating back to prokaryotes. ApeC-containing proteins (ACPs) have been found in various marine and aquatic invertebrates, but their functions and the underlying mechanisms are largely unknown. Early studies suggested that amphioxus ACP1 and ACP2 bind to bacterial cell walls and have a role in immunity. Here we identified another two amphioxus ACPs (ACP3 and ACP5), which belong to the same phylogenetic clade with ACP1/2, but show distinct expression patterns and sequence divergence (40-50% sequence identities). Both ACP3 and ACP5 were mainly expressed in the intestine and hepatic cecum, and could be up-regulated after bacterial challenge. Both prokaryotic-expressed recombinant ACP3 and ACP5 could bind with several species of bacteria and yeasts, showing agglutinating activity but no microbicidal activity. ELISA assays suggested that their ApeC domains could interact with peptidoglycan (PGN), but not with lipoteichoic acid (LTA), lipopolysaccharides (LPS) and zymosan A. Furthermore, they can only bind to Lys-type PGN from Staphylococcus aureus, but not to DAP-type PGN from Bacillus subtilis and not to moieties of PGN such as MDPs, NAMs and NAGs. This recognition spectrum is different from that of ACP1/2. We also found that when expressed in mammalian cells, ACP3 could interact with TRAF6 via a conserved non-ApeC region, which inhibited the ubiquitination of TRAF6 and hence suppressed downstream NF-κB activation. This work helped define a novel subfamily of ACPs, which have conserved structures, and have related yet diversified molecular functions. Its members have dual roles, with ApeC as a lectin and a conserved unknown region as a signal transduction regulator. These findings expand our understanding of the ACP functions and may guide future research on the role of ACPs in different animal clades.

Papain-Like Cysteine Protease Gene Family in Fig (Ficus carica L.): Genome-Wide Analysis and Expression Patterns.

The papain-like cysteine proteases (PLCPs) are the most abundant family of cysteine proteases in plants, with essential roles in biotic/abiotic stress responses, growth and senescence. Papain, bromelain and ficin are widely used in food, medicine and other industries. In this study, 31 PLCP genes (FcPCLPs) were identified in the fig (Ficus carica L.) genome by HMM search and manual screening, and assigned to one of nine subfamilies based on gene structure and conserved motifs. SAG12 and RD21 were the largest subfamilies with 10 and 7 members, respectively. The FcPCLPs ranged from 1,128 to 5,075 bp in length, containing 1-10 introns, and the coding sequence ranged from 624 to 1,518 bp, encoding 207-505 amino acids. Subcellular localization analysis indicated that 24, 2, and 5 PLCP proteins were targeted to the lysosome/vacuole, cytoplasm and extracellular matrix, respectively. Promoter (2,000 bp upstream) analysis of FcPLCPs revealed a high number of plant hormone and low temperature response elements. RNA-seq revealed differential expression of 17 FcPLCPs in the inflorescence and receptacle, and RD21 subfamily members were the major PLCPs expressed in the fruit; 16 and 5 FcPLCPs responded significantly to ethylene and light, respectively. Proteome analyses revealed 18 and 5 PLCPs in the fruit cell soluble proteome and fruit latex, respectively. Ficins were the major PLCP in fig fruit, with decreased abundance in inflorescences, but increased abundance in receptacles of commercial-ripe fruit. FcRD21B/C and FcALP1 were aligned as the genes encoding the main ficin isoforms. Our study provides valuable multi-omics information on the FcPLCP family and lays the foundation for further functional studies.

Lactobacillus paracasei modulates the gut microbiota and improves inflammation in type 2 diabetic rats.

This study aimed to investigate the effects of probiotic Lactobacillus paracasei NL41 on inflammation and the gut microbiota of type 2 diabetic (T2D) rats induced by high-fat diet (HFD) and low-dose streptozotocin (STZ). A T2D rat model was established by inducing Sprague-Dawley rats with HFD/STZ, followed by 12-weeks L. paracasei NL41 gavage. The blood, colonic tissues, and feces samples of these rats were collected for inflammation, histology, and intestinal microbiota profiling. L. paracasei NL41 treatment induced remarkable improvement in the inflammatory status by decreasing the levels of serum lipopolysaccharides (LPS), free fatty acids (FFA), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-8 and increasing the level of IL-10. Gut barrier function was significantly protected in NL41-treated rats. Moreover, the strain NL41 induced changes in the microbiota structure and influenced the relative abundance of the key species. Specifically, Bacteroides, Clostridia (specifically, Ruminococcus torques), and Parasutterella were significantly reduced, while some beneficial microorganisms (Bacteroidales_S24-7_group and the families Lachnospiraceae and Ruminococcaceae) were enriched by NL41. The correlational analyses indicated that L. paracasei NL41 ameliorating inflammation was closely related to the key species of the gut microbiota. The present study indicates that probiotic L. paracasei NL41 decreases LPS-induced inflammation by improving the gut microbiota and preserving intestinal integrity.

Facile bead-to-bead cell-transfer method for serial subculture and large-scale expansion of human mesenchymal stem cells in bioreactors.

The conventional planar culture of adherent cells is inefficient for large-scale manufacturing of cell and gene therapy products. We developed a facile and efficient bead-to-bead cell-transfer method for serial subculture and large-scale expansion of human mesenchymal stem cells (hMSCs) with microcarriers in bioreactors. We first compared culture medium with and without nucleosides and found the former maintained the expression of surface markers of hMSCs during their prolonged culture and enabled faster cell proliferation. Subsequently, we developed our bead-to-bead cell transfer method to subculture hMSCs and found that intermittent agitation after adding fresh microcarriers to cell-populated microcarriers could promote spontaneous cell migration to fresh microcarriers, reduce microcarrier aggregation, and improve cell yield. This method enabled serial subculture of hMSCs in spinner flasks from passage 4 to passage 9 without using proteolytic enzymes, which showed faster cell proliferation than the serial planar cultures undergoing multiple enzyme treatment. Finally, we used the medium containing nucleosides and our bead-to-bead cell transfer method for cell culture scale-up from 4- to 50-L cultures in single-use bioreactors. We achieved a 242-fold increase in the number of cells to 1.45 × 1010 after 27-day culture and found that the cells harvested from the bioreactors maintained proliferation ability, expression of their surface markers, tri-lineage differentiation potential and immunomodulatory property. This study shows the promotive effect of nucleosides on hMSC expansion and the potential of using our bead-to-bead transfer method for larger-scale manufacturing of hMSCs for cell therapy.

Metabolomics study reveals the potential evidence of metabolic reprogramming towards the Warburg effect in precancerous lesions.

Background: Most tumors have an enhanced glycolysis flux, even when oxygen is available, called the aerobic glycolysis or the Warburg effect. Metabolic reprogramming promotes cancer progression, and is even related to the tumorigenesis. However, it is not clear whether the observed metabolic changes act as a driver or a bystander in cancer development. Methods: In this study, the metabolic characteristics of oral precancerous cells and cervical precancerous lesions were analyzed by metabolomics, and the expression of glycolytic enzymes in cervical precancerous lesions was evaluated by RT-PCR and Western blot analysis. Results: In total, 115 and 23 metabolites with reliable signals were identified in oral cells and cervical tissues, respectively. Based on the metabolome, oral precancerous cell DOK could be clearly separated from normal human oral epithelial cells (HOEC) and oral cancer cells. Four critical differential metabolites (pyruvate, glutamine, methionine and lysine) were identified between DOK and HOEC. Metabolic profiles could clearly distinguish cervical precancerous lesions from normal cervical epithelium and cervical cancer. Compared with normal cervical epithelium, the glucose consumption and lactate production increased in cervical precancerous lesions. The expression of glycolytic enzymes LDHA, HK II and PKM2 showed an increased tendency in cervical precancerous lesions compared with normal cervical epithelium. Conclusions: Our findings suggest that cell metabolism may be reprogrammed at the early stage of tumorigenesis, implying the contribution of metabolic reprogramming to the development of tumor.

Protein kinase function of pyruvate kinase M2 and cancer.

Pyruvate kinase is a terminal enzyme in the glycolytic pathway, where it catalyzes the conversion of phosphoenolpyruvate to pyruvate and production of ATP via substrate level phosphorylation. PKM2 is one of four isoforms of pyruvate kinase and is widely expressed in many types of tumors and associated with tumorigenesis. In addition to pyruvate kinase activity involving the metabolic pathway, increasing evidence demonstrates that PKM2 exerts a non-metabolic function in cancers. PKM2 has been shown to be translocated into nucleus, where it serves as a protein kinase to phosphorylate various protein targets and contribute to multiple physiopathological processes. We discuss the nuclear localization of PKM2, its protein kinase function and association with cancers, and regulation of PKM2 activity.

Engineer probiotic bifidobacteria for food and biomedical applications - Current status and future prospective.

Bifidobacteria are members of the human gut microbiota and have shown to exert beneficial effects on their host. Certain strains have a long history of safe and effective use as probiotics. Due to the lack of efficient genetic tools, however, little is known about the molecular mechanisms on which these health-promoting properties are based, thus limiting the synthetic biology applications in bifidobacteria. Here, we discuss the recent development of genetic tools and their engagement in engineering bifidobacteria for food and biomedical applications, from eliminating antibiotic resistance mobile elements and improving robustness to preventing pathogen infections and delivering therapeutics for cancer treatment. In addition, we highlight the application of emerging genome engineering techniques for manipulating the bifidobacterial genome. Finally, we provide our perspective on the future development of synthetic biology techniques and programmed probiotic bifidobacteria with enhanced robustness and designer functionalities.

Metabolic Reprogramming of Chemoresistant Cancer Cells and the Potential Significance of Metabolic Regulation in the Reversal of Cancer Chemoresistance.

Metabolic reprogramming is one of the hallmarks of tumors. Alterations of cellular metabolism not only contribute to tumor development, but also mediate the resistance of tumor cells to antitumor drugs. The metabolic response of tumor cells to various chemotherapy drugs can be analyzed by metabolomics. Although cancer cells have experienced metabolic reprogramming, the metabolism of drug resistant cancer cells has been further modified. Metabolic adaptations of drug resistant cells to chemotherapeutics involve redox, lipid metabolism, bioenergetics, glycolysis, polyamine synthesis and so on. The proposed metabolic mechanisms of drug resistance include the increase of glucose and glutamine demand, active pathways of glutaminolysis and glycolysis, promotion of NADPH from the pentose phosphate pathway, adaptive mitochondrial reprogramming, activation of fatty acid oxidation, and up-regulation of ornithine decarboxylase for polyamine production. Several genes are associated with metabolic reprogramming and drug resistance. Intervening regulatory points described above or targeting key genes in several important metabolic pathways may restore cell sensitivity to chemotherapy. This paper reviews the metabolic changes of tumor cells during the development of chemoresistance and discusses the potential of reversing chemoresistance by metabolic regulation.

HPV-mediated down-regulation of NOD1 inhibits apoptosis in cervical cancer.

Cervical cancer is the fourth most common malignant tumor in women worldwide. The persistent infection of high-risk Human Papillomavirus (hrHPV) is considered to be the primary cause of this disease. As an innate immune receptor, the nucleotide-binding oligomerization domain protein-1 (NOD1) recognizes the pathogen-associated molecular pattern (PAMP), subsequently initiating immune responses. NOD1 is also involved in the apoptotic signaling pathway and mutates in many cancer cells. In the study, we revealed that NOD1 expression decreased during the progression of cervical intraepithelial neoplasia to cervical cancer and that HPV16 E6/E7 oncoproteins induced down-regulation of NOD1. Moreover, the activation of NOD1 promoted the apoptosis of HPV16-positive cervical cancer cells. The data indicated that the dysregulation of NOD1-mediated inflammation and apoptosis may contribute to cervical intraepithelial neoplasia progression and cervical cancer.

Mitochondria-localised ZNFX1 functions as a dsRNA sensor to initiate antiviral responses through MAVS.

In the past two decades, emerging studies have suggested that DExD/H box helicases belonging to helicase superfamily 2 (SF2) play essential roles in antiviral innate immunity. However, the antiviral functions of helicase SF1, which shares a conserved helicase core with SF2, are little understood. Here we demonstrate that zinc finger NFX1-type containing 1 (ZNFX1), a helicase SF1, is an interferon (IFN)-stimulated, mitochondrial-localised dsRNA sensor that specifically restricts the replication of RNA viruses. Upon virus infection, ZNFX1 immediately recognizes viral RNA through its Armadillo-type fold and P-loop domain and then interacts with mitochondrial antiviral signalling protein to initiate the type I IFN response without depending on retinoic acid-inducible gene I-like receptors (RLRs). In short, as is the case with interferon-stimulated genes (ISGs) alone, ZNFX1 can induce IFN and ISG expression at an early stage of RNA virus infection to form a positively regulated loop of the well-known RLR signalling. This provides another layer of understanding of the complexity of antiviral immunity.