LINC00941 promotes pancreatic cancer malignancy by interacting with ANXA2 and suppressing NEDD4L-mediated degradation of ANXA2

Engineering a dynamic extracellular matrix using thrombospondin-1 to propel hepatocyte organoids reprogramming and improve mouse liver regeneration post-transplantation

Hepatocyte organoids (HOs) hold significant potential for constructing bioartificial liver construction, toxicology research, and liver failure therapies. However, challenges such as difficulties in induced pluripotent stem cells (iPSCs) harvest and differentiation, safety concerns of tumor-derived matrices, and limited primary cell regulation hinder clinical applications. In this study, we developed a non-tumor-derived decellularized extracellular matrix (dECM) system with tunable mechanical properties and viscoelasticity to enhance stem cell proliferation and organoid functionality using thrombospondin-1 (THBS1). Nanoindentation and transcriptomic analysis revealed that THBS1 mediates adaptation and remodeling between organoids and ECM proteins, exhibiting native tissue-like viscoelasticity and up-regulated reprogramming transcriptional factors KLF4 and SOX2 via the YAP/TAZ pathway. Transplanting HOs presenting reprogramming effects into a 70 % hepatectomy model demonstrated improved liver regeneration, underscoring the potential of the THBS1-based dynamic ECM system in organoids manipulation and liver regeneration.

The role of LncRNA-MANCR induced by HIF-1α drive the malignant progression of pancreatic cancer by targeting miRNA-494/SIRT1 signaling axis under hypoxic conditions

This study revealed the prospective biological role and fundamental mechanisms of hypoxia-induced lncRNA-MANCR (MANCR), which is notably upregulated in pancreatic cancer (PC). This work uncovered the potential biological function and underlying mechanisms of hypoxia-induced MANCR, which is significantly elevated in PC. Microarray assays confirmed MANCR expression in the tissues of patients with PC and patients with chronic pancreatitis (CP), which positively correlated with sirtuin-1 (SIRT1) mRNA levels. Chromatin immunoprecipitation and luciferase assays were employed to gauge binding within the hypoxia-inducible factor-1α (HIF-1α)/MANCR/miRNA-494/SIRT1 pathway. Additionally, the association between MANCR expression and the clinical outcomes of patients with PC was confirmed. MANCR is significantly upregulated in PC cells under hypoxic conditions, which is closely linked to poor prognosis in patients with PC. Depletion of MANCR repressed in vitro proliferation, migration, and invasion of PC cells and in vivo growth of PC xenograft tumours. We further demonstrated that MANCR is localised in the cytoplasm and competitively binds miR-494, which directly targets SIRT1. Mechanically, the overexpression of SIRT1 improved the stability of the HIF-1α protein through deacetylation, leading to enhanced HIF-1α assembly. Moreover, MANCR underwent transcriptional regulation by HIF-1α in a hypoxic setting. This modulation was ascribed to HIF-1α binding to hypoxia response elements present in the MANCR promoter sequence. Data revealed the potential possibility of feedback between MANCR and HIF-1α, which may be conducive to hypoxia-induced oncogenicity and PC tumorigenesis, thereby providing a suitable therapeutic target.

A review of molecular interplay between inflammation and cancer: The role of lncRNAs in pathogenesis and therapeutic potential

The inflammatory microenvironment (IME) has been demonstrated to facilitate the initiation and progression of tumors throughout the inflammatory process. Simultaneously, cancer can initiate or intensify the inflammatory response, thereby promoting tumor progression. This review examines the dual role of long non-coding RNAs (lncRNAs) in the interplay between inflammation and cancer. LncRNA modulate inflammation-induced cancer by influencing the activation of signaling pathways (NF-κB, Wnt/β-catenin, mTOR, etc), microRNA (miRNA) sponging, protein interactions, interactions with immune cells, and encoding short peptides. In contrast, lncRNAs also impact cancer-induced inflammatory processes by regulating cytokine expression, mediating tumor-derived extracellular vesicles (EVs), modulating intracellular reactive oxygen species (ROS) levels, and facilitating metabolic reprogramming. Furthermore, the therapeutic potential of lncRNA and the challenges of clinical translation were explicitly discussed as well. Overall, this review aims to provide a comprehensive and systematic resource for future researchers investigating the impact of lncRNAs on inflammation and cancer.

LncRNA BDNF-AS binds to DNMT1 to suppress angiogenesis in glioma by promoting NEDD4L-mediated YAP1 ubiquitination

Glioma, a highly aggressive brain tumor, is characterized by high mortality and frequent recurrence rates. Angiogenesis is a critical hallmark of glioma progression. However, the regulatory role and underlying mechanism of lncRNA brain-derived neurotrophic factor-antisense (BDNF-AS) in glioma angiogenesis remain poorly understood and warrant further investigation. Malignant characteristics of glioma cells were evaluated using CCK-8, colony formation, scratch, transwell, flow cytometry, and tube formation assays. The expression levels of genes and proteins were detected by RT-qPCR, western blot, and IHC assays. The methylation level of NEDD4-like E3 ubiquitin protein ligase (NEDD4L) was determined using MSP. The interactions among molecules were validated using RIP, ChIP, and Co-IP. Our study revealed significantly downregulated BDNF-AS expression in glioma cells. BDNF-AS overexpression markedly attenuated the malignant characteristics of glioma cells, as evidenced by decreased viability, proliferation, migration, invasion, and angiogenesis, along with increased apoptosis. These tumor-suppressive effects were significantly abrogated by NEDD4L knockdown. Mechanistically, BDNF-AS could interact with DNA methyltransferase 1 (DNMT1) expression, leading to reduced NEDD4L promoter methylation and upregulation of NEDD4L expression. Additionally, NEDD4L-mediated promotion of YAP1 ubiquitination to decline YAP1 and VEGFA expression. Finally, BDNF-AS exerted potent anti-tumor effects by mediating NEDD4L/YAP1/VEGFA axis, as demonstrated by suppressed tumor growth in glioma-bearing mice and attenuated malignant features in glioma cells. BDNF-AS suppressed cell viability, proliferation, migration, and invasion, and promoted cell apoptosis of glioma cells, attenuated angiogenesis of human umbilical vein endothelial cells (HUVECs), and tumor growth via regulating NEDD4L/YAP1/VEGFA axis.

USP10/XAB2/ANXA2 axis promotes DNA damage repair to enhance chemoresistance to oxaliplatin in colorectal cancer

BACKGROUND

Oxaliplatin-based chemotherapy is the first-line treatment for colorectal cancer (CRC). However, oxaliplatin resistance remains a major challenge contributing to treatment failure and poor prognosis. An increased capacity for DNA damage repair is a key mechanism underlying oxaliplatin resistance. Although XPA binding protein 2 (XAB2) is implicated in various DNA damage repair mechanisms, its specific role in mediating oxaliplatin resistance remains unclear.

METHODS

XAB2 was identified through analysis of public datasets. Western blot analysis and immunohistochemistry were performed to evaluate XAB2 expression, while survival analysis was performed to assess its clinical significance in CRC. Functional experiments were then conducted to assess the impact of XAB2 on proliferation, DNA damage repair, and oxaliplatin resistance in CRC. RNA sequencing (RNA-seq) and Chromatin immunoprecipitation-sequencing (ChIP-seq) were used to identify XAB2 target genes. Co-immunoprecipitation (Co-IP) and mass spectrometry were used to identify the proteins interacting with XAB2. Dual-luciferase reporter assays, ChIP-qPCR, Co-IP, ubiquitination site mass spectrometry, and ubiquitin assays were used to analyse the interactions and potential mechanisms involving XAB2, Annexin A2 (ANXA2), and ubiquitin-specific protease 10 (USP10).

RESULTS

XAB2 was found to be expressed in CRC and was associated with poor prognosis in patients with CRC. XAB2 promoted CRC cell proliferation and enhanced oxaliplatin resistance by promoting DNA damage repair. Mechanistically, CRC cells treated with oxaliplatin exhibited increased USP10 nuclear expression. USP10 bound to XAB2 and deubiquitinated XAB2 K48-linked polyubiquitination at K593, thereby stabilising XAB2 by reducing its degradation via the ubiquitin-proteasome pathway. XAB2 upregulates ANXA2 expression at the transcriptional level by binding to the ANXA2 promoter, thereby promoting DNA damage repair, mitigating oxaliplatin-induced DNA damage, and enhancing oxaliplatin resistance.

CONCLUSIONS

In summary, this study demonstrates that the USP10/XAB2/ANXA2 axis promotes proliferation, DNA damage repair, and oxaliplatin resistance in CRC. These findings uncover a novel mechanism of oxaliplatin resistance in CRC and suggest potential therapeutic targets for improving the efficacy of oxaliplatin in CRC treatment.

Soybean Agglutinin Induced Apoptotic Effects by Down-Regulating ANXA2 Through FAK Pathway in IPEC-J2 Cells

Soybean agglutinin (SBA) is an anti-nutritional factor in soybean, possesses toxic effects by binding to intestinal epithelial cells, and finally interferes the digestion and absorption of nutrients in humans and animals. Annexin A2 (ANXA2) is one of the SBA-specific binding proteins in intestinal epithelial cells and participates in multiple cellular biological processes. However, whether SBA affects apoptosis through ANXA2 and its apoptosis-related pathway remains unclear. IPEC-J2 is an ideal model to study human intestinal health. Therefore, this study aims to investigate the effects of ANXA2 on SBA-induced intestinal epithelial cell apoptosis and the related pathway mechanism using IPEC-J2 as a cell model. The results showed that SBA induced the apoptosis through FAK signal pathway and decreased the gene and protein expressions of ANXA2 in IPEC-J2. The expression of ANXA2 protein had a negative correlation with the apoptosis rates, and a positive correlation with the expression of FAK protein and FAK pathway downstream proteins. In conclusion, SBA induced apoptosis of IPEC-J2 cells by downregulating the expression of ANXA2, which activated the FAK pathway. These findings highlight the toxic mechanism of SBA, which will provide basis for studying the toxicity mechanisms of other food-derived anti-nutrients and provide a new perspective for human gastrointestinal health and related cancer treatment.

NEDD4L inhibits epithelial-mesenchymal transition in gastric cancer by mediating BICC1 ubiquitination

Epithelial-mesenchymal transition (EMT) is a critical stage in the metastasis of gastric cancer (GC). Further clarification of the EMT process in GC is still needed. This study examined the effects of the NEDD4L/BICC1 axis on GC proliferation and the EMT process. Thirty GC patients were enrolled in this study to assess the expression of BICC1 and NEDD4L in tumor samples. A xenograft tumor model in mice was created to investigate BICC1's function in vivo. The proliferation, migration, and invasion of GC cells were evaluated using colony formation, transwell, and wound healing assays. Western blot determined the expression levels of EMT-associated proteins. Co-immunoprecipitation (Co-IP) elucidated the mechanism by which NEDD4L regulates BICC1. BICC1 was found to be overexpressed in tumors. Additionally, BICC1 knockdown inhibited the growth of GC cells in vivo and prevented their migration, invasion, proliferation, and EMT. Furthermore, BICC1 activated the PI3K/AKT pathway, which facilitated cancer progression. Tumor tissues and GC cells exhibited low expression levels of NEDD4L. Conversely, NEDD4L overexpression promoted the ubiquitination and degradation of BICC1 protein, thereby inhibiting GC cell proliferation, migration, invasion, and EMT processes. Our study demonstrated that NEDD4L acts as a tumor suppressor in GC, while BICC1 functions as a pro-tumorigenic factor. The NEDD4L/BICC1 axis plays a significant role in the metastasis and progression of GC.

Exosomal AFAP1-AS1 Promotes the Growth, Metastasis, and Glycolysis of Pituitary Adenoma by Inhibiting HuR Degradation

Exosomal long noncoding RNAs (lncRNAs), which are highly expressed in tumor-derived exosomes, regulate various cellular behaviors such as cell proliferation, metastasis, and glycolysis by facilitating intercellular communication. Here, we explored the role and regulatory mechanism of tumor-derived exosomal lncRNAs in pituitary adenomas (PA). We isolated exosomes from PA cells, and performed in vitro and in vivo assays to examine their effect on the proliferation, metastasis, and glycolysis of PA cells. In addition, we conducted RNA pull-down, RNA immunoprecipitation, co-immunoprecipitation, and ubiquitination assays to investigate the downstream mechanism of exosomal AFAP1-AS1. Exosomes from PA cells augmented the proliferation, mobility, and glycolysis of PA cells. Moreover, AFAP1-AS1 was significantly enriched in these exosomes and stimulated the growth, migration, invasion, and glycolysis of PA cells in vitro, as well as tumor metastasis in vivo. It also enhanced the binding affinity between Hu antigen R (HuR) and SMAD-specific E3 ubiquitin protein ligase 1 (SMURF1), resulting in HuR ubiquitination and degradation accompanied by enhanced expression of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). Moreover, HuR overexpression alleviated the exosomal AFAP1-AS1-mediated promotion of growth, metastasis, and glycolysis effects. These findings indicate that tumor-derived exosomal AFAP1-AS1 modulated SMURF1-mediated HuR ubiquitination and degradation to upregulate HK2 and PKM2 expression, thereby enhancing PA cell growth, metastasis, and glucose metabolism. This suggests targeting exosomal AFAP1-AS1 may be a potential strategy for the treatment of PA.

lncRNAs: the unexpected link between protein synthesis and cancer adaptation

Cancer progression relies on the ability of cells to adapt to challenging environments overcoming stresses and growth constraints. Such adaptation is a multifactorial process that depends on the rapid reorganization of many basic cellular mechanisms. Protein synthesis is often dysregulated in cancer, and translational reprogramming is emerging as a driving force of cancer adaptive plasticity. Long non-coding RNAs (lncRNAs) represent the main product of genome transcription. They outnumber mRNAs by an order of magnitude and their expression is regulated in an extremely specific manner depending on context, space and time. This heterogeneity is functional and allows lncRNAs to act as context-specific, fine-tuning controllers of gene expression. Multiple recent evidence underlines how, besides their consolidated role in transcription, lncRNAs are major players in translation control. Their capacity to establish multiple and highly dynamic interactions with proteins and other transcripts makes these molecules able to play a central role across all phases of protein synthesis. Even if through a myriad of different mechanisms, the action of these transcripts is dual. On one hand, by modulating the overall translation speed, lncRNAs participate in the process of metabolic adaptation of cancer cells under stress conditions. On the other hand, by prioritizing the synthesis of specific transcripts they help cancer cells to maintain high levels of essential oncogenes. In this review, we aim to discuss the most relevant evidence regarding the involvement of lncRNAs in translation regulation and to discuss how this specific function may affect cancer plasticity and resistance to stress. We also expect to provide one of the first collective perspectives on the way these transcripts modulate gene expression beyond transcription.

Histone lactylation promotes multidrug resistance in hepatocellular carcinoma by forming a positive feedback loop with PTEN

FOLFOX (5-fluorouracil, oxaliplatin, folinic acid) is a standard treatment for hepatocellular carcinoma, but its efficacy is often limited by drug resistance, the underlying mechanisms of which remain unclear. In this study, oxaliplatin (OXA)- and 5-fluorouracil (5-Fu)-resistant hepatocellular carcinoma cell lines were established, and enhanced glycolytic activity was identified in resistant cells. Inhibiting glycolysis effectively suppressed the malignant behavior of both OXA- and 5-Fu-resistant cells. Mechanistically, active glycolysis induced elevated levels of lactylation, predominantly histone lactylation, with H3K14la playing a key role in regulating gene expression. The ubiquitin E3 ligase NEDD4 was identified as a downstream target of H3K14la. Furthermore, NEDD4, regulated by histone lactylation, interacted with PTEN to mediate its ubiquitination and subsequent degradation. The downregulation of PTEN formed a positive feedback loop, further driving the malignant progression of OXA- and 5-Fu-resistant cells. This study elucidates a shared mechanism underlying OXA and 5-Fu resistance in hepatocellular carcinoma and highlights a promising therapeutic target for overcoming clinical chemotherapy resistance.

LINC00941 affects the proliferation, apoptosis and differentiation of osteoblasts by regulating the miR-335-5p/KAT7 axis

BACKGROUND

Fractures are the prevalent traumatic conditions encountered in orthopedic practices. The rising incidence of fractures has emerged as a pressing global health concern. Although the majority of individuals with fractures experience complete recovery of bone structure and function, approximately 10% of those with fractures exhibit delayed fracture healing (DFH). The objective of this investigation was to explore the function and underlying mechanisms of LINC00941 in the advancement of DFH, as well as its involvement in the regulation of osteoblastic differentiation by regulating the miR-335-5p/KAT7 axis.

METHODS

The expression levels of LINC00941, miR-335-5p, KAT7 and osteoblast differentiation-related markers were assessed using RT-qPCR. The proliferation of MC3T3-E1 cells was evaluated through the CCK-8 assay, and cell apoptosis was analyzed via flow cytometry. The targeted regulatory relationships between LINC00941 and miR-335-5p, as well as between miR-335-5p and KAT7 were verified by a dual-luciferase reporter gene assay.

RESULT

The expression of LINC00941 was significantly up regulated, while miR-335-5p exhibited a notable downregulation in DFH patients, both of LINC00941 and miR-335-5p have been identified as potential predicted markers for DFH. Furthermore, LINC00941 has been demonstrated to inhibit osteoblast proliferation, promote apoptosis, and suppress osteoblast differentiation through the regulation of the miR-335-5p/KAT7 axis.

CONCLUSION

LINC00941/ miR-335-5p/KAT7 axis may be a therapeutic target for DFH.

HOXC-AS1 and EZH2 interaction increase HOXC9 expression and promote the malignant transformation of oral leukoplakia

Objective: To investigate the role of HOXC9 in the transformation of oral leukoplakia (OLK) to oral squamous cell carcinoma (OSCC) and its effectiveness as a new molecular marker for oral leukoplakia carcinogenesis. Materials and Methods: We assessed HOXC9 in OLK and OSCC using immunohistochemistry (IHC). Colony formation and transwell experiment were employed to appraise the function of HOXC9 in the malignant transformation of OLK. ChIP-qPCR, CO-IP, RIP-qPCR, RNA pull down and mass spectrometry were using to evaluate the molecular mechanism of HOXC9. Results: HOXC9 expression was higher in patients with OSCC than in those with OLK, which is associated with increased malignant transformation of OLK. Functional experiments suggested that HOXC9 induces the acquisition of cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT). Subsequently, we found that the HOXC9-mediated malignant phenotype was reversed by HOXC-AS1 depletion. Mechanistically, HOXC-AS1 regulates H3K27me3 methylation and EZH2 as a potential HOXC-AS1-HOXC9 interacting protein. Finally, we found that the 251-619nt nucleotide of HOXC-AS1 competitively binds to EZH2. Conclusion: HOXC-AS1 competitively binds to EZH2, inhibiting its binding to H3 in the HOXC9 promoter region, resulting in a decrease in H3K27me3 and enhanced expression of HOXC9, thereby promoting CSCs and EMT in oral leukoplakia, ultimately leading to malignant transformation into oral squamous cell carcinoma.

Upregulation of long noncoding RNAs LINC00941 and ABHD11-AS1 is associated with intrahepatic cholangiocarcinoma

ObjectiveMany long noncoding RNAs (lncRNAs) are associated with liver cancers, mainly hepatocellular carcinoma (HCC) and to a smaller extent intrahepatic cholangiocarcinoma (CCA). Most of such lncRNAs show similar dysregulation patterns when the two types of tumors are compared, suggesting that these aberrations are characteristic features of these liver tumor types. In the present study, we aimed to identify some candidate lncRNAs that are associated specifically with CCA.MethodsAccording to The Cancer Genome Atlas data, we chose LINC00941, ABHD11-AS1, and CASC8 as promising biomarkers dysregulated in CCA but unaffected in HCC. We first verified their upregulation in an existing transcriptomic dataset for CCA patients. Next, we estimated expression levels of these three lncRNAs by reverse-transcription quantitative PCR in a group of paired (tumorous/adjacent) postsurgery tissue samples from 110 patients with various liver lesions: CCA, HCC, combined HCC-CCA, or benign liver tumors.ResultsSignificant upregulation of LINC00941 and ABHD11-AS1 was noted in most of the investigated CCA samples, whereas in HCC samples, increased expression of these two lncRNAs was observed only in some types of cases (mainly characterized by an advanced tumor stage). In contrast, CASC8 manifested extremely low expression and no diagnostic potential in all the tested liver samples. Analyzing expression correlations of lncRNAs with candidate genes, we obtained strong evidence for LINC00941-mediated upregulation of CAPRIN2 in CCA.ConclusionsFor the first time, we show the upregulation of LINC00941 and ABHD11-AS1 in CCA and report their good potential as diagnostic biomarkers for this type of liver tumor.

NEDD4L Suppresses Proliferation and Promotes Apoptosis by Ubiquitinating RAC2 Expression and Acts as a Prognostic Biomarker in Clear Cell Renal Cell Carcinoma

Neural precursor cell expressed developmentally down-regulated 4-like (NEDD4L) is an HECT (homologous to E6AP C terminus)-type E3 ubiquitin ligase. As previously documented, bioinformatics analysis revealed NEDD4L is downregulated in clear cell renal cell carcinoma (ccRCC). However, the target substrate regulated by NEDD4L in ccRCC remains unknown. Here, we assessed whether NEDD4L regulates Ras-related C3 botulinum toxin substrate 2 (RAC2) expression in ccRCC. In our study, integrated bioinformatics analysis indicated that low expression of NEDD4L and high expression of RAC2 were both associated with poor prognosis of ccRCC, pro-tumorigenic immunity, and multiple tumor-associated pathways. Our data confirmed the hypothesis indicated in the previous studies related to the downregulation of NEDD4L in ccRCC. NEDD4L was identified to target the RAC2 threonine 108-proline motif, and RAC2 overexpression rescued NEDD4L-mediated cell apoptosis and inhibition of cell growth and migration. Therefore, RAC2 is a novel and first identified target of NEDD4L in ccRCC, and the aberrant less expression of NEDD4L and consequent RAC2 upregulation may contribute to renal carcinogenesis. Our study offers insight into NEDD4L as a potential future therapeutic target for renal cell carcinoma or as a novel prognostic biomarker.

LINC00894 targets Annexin A2 to regulate oxaliplatin resistance in hepatocellular carcinoma: ANXA2 protein function

To investigate the role of LINC00894 in oxaliplatin chemoresistance of hepatocellular carcinoma (HCC) and its mechanisms. The oxaliplatin-resistant HCC cell lines were established. IC50 of oxaliplatin was calculated by CCK-8 assay. Cell viability was detected using clonal formation experiment, while cell apoptosis was accessed by flow cytometry. RNA binding protein immunoprecipitation and RNA pull-down were performed to explore the interaction of LINC00894 and ANXA2. The expressions of RNA and protein were tested by qRT-PCR and western blot respectively. Tumor xenograft was performed to detect the effect of LINC00894 in vivo. The expression of ki67 was evaluated by immunohistochemistry staining. LINC00894 was overexpressed in HCC cells resistant to oxaliplatin. Elevated LINC00894 promoted HCC cells resistance to oxaliplatin, whereas silence of LINC00894 improved HCC sensitivity to oxaliplatin. LINC00894 could bind to the ANXA2 protein, enhanced the stability of the ANXA2 protein and reduced its ubiquitination. Furthermore, LINC00894 modulated HCC resistance to oxaliplatin both in vitro and in vivo by targeting the ANXA2 protein.LINC00894 enhanced the stability of ANXA2 protein and attenuated its ubiquitination by interacting with it, thereby promoting oxaliplatin resistance in HCC. Our findings contributed to understanding the role of these mechanisms in the process of oxaliplatin resistance in HCC.

E3 Ubiquitin Ligase NEDD4L Negatively Regulates Skin Tumorigenesis by Inhibiting IL-6/GP130 Signaling Pathway

IL-6 signaling plays a crucial role in the survival and metastasis of skin cancer. NEDD4L acts as a suppressor of IL-6 signaling by targeting GP130 degradation. However, the effects of the NEDD4L-regulated IL-6/GP130 signaling pathway on skin cancer remain unclear. In this study, protein expression levels of NEDD4L and GP130 were measured in tumor tissues from patients with cutaneous squamous cell carcinoma. Skin tumors were induced in wild-type and Nedd4l-knockout mice, and activation of the IL-6/GP130/signal transducer and activator of transcription 3 signaling pathway was detected. The results indicated a negative correlation between the protein expression levels of NEDD4L and GP130 in cutaneous squamous cell carcinoma tissues from patients. Nedd4l deficiency significantly promoted 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate-induced skin tumorigenesis and benign-to-malignant conversion by activating the IL-6/GP130/signal transducer and activator of transcription 3 signaling pathway, which was abrogated by supplementation with the GP130 inhibitor SC144. Furthermore, our findings suggested that NEDD4L can interact with GP130 and promote its ubiquitination in skin tumors. In conclusion, our results indicate that NEDD4L could act as a tumor suppressor in skin cancer, and inhibition of GP130 could be a potential therapeutic method for treating this disease.

LINC00941 is a diagnostic biomarker for lung adenocarcinoma and promotes tumorigenesis through cell autophagy

Non-small cell lung cancer (NSCLC) is a lethal malignancy. There is mounting evidence indicating that lncRNAs are crucial players with dual roles as both biomarkers and regulators across various cancers. It was reported that LINC00941 plays a cancer-promoting role in NSCLC. However, its impact on tumour autophagy remains poorly understood. In this study, we developed a risk assessment model and identified an autophagy-related lncRNA LINC00941, which has independent predictive and early diagnostic potential. Using RT-qPCR analysis, we confirmed the upregulation of LINC00941 in tumour tissues and cell lines of human lung adenocarcinoma (LUAD). Functional assays, such as CCK8, colony formation and xenograft models, demonstrated the cancer-promoting activity of LINC00941 both in vitro and in vivo. Further analysis using Western blotting analysis, mRFP-GFP-LC3 double fluorescence lentivirus vector and transmission electron microscopy (TEM) confirmed that the knockdown of LINC00941 triggered autophagy. These results indicate that knockdown of LINC00941 induces autophagy and impairs the proliferation of LUAD. Therefore, we propose LINC00941 as an independent biomarker for early diagnosis as well as a therapeutic target in LUAD.

AGR2 facilitates teratoma progression by regulating glycolysis via the AnXA2/EGFR axis

Anterior gradient-2 (AGR2) is highly expressed in several tumors and plays an important role in tumor development. However, the biological function of AGR2 in teratomas has not yet been thoroughly studied. In this study, AGR2 was found to be upregulated in teratoma tissues and in human testicular teratoma cell lines by Western blotting and qRT-PCR assays. A DNA Methylation-Specific PCR assay demonstrated that AGR2 upregulation resulted from hypomethylated AGR2 in teratoma cells. NCC-IT and NT2-D1 cells were transfected with pcDNA-AGR2 or sh-AGR2 to obtain AGR2-overexpressed or -silenced cells, and cell proliferation, invasion and glycolysis were determined using CCK-8, 5-ethynyl-2'-deoxyuridine (EdU), Transwell assays, and commercial kits. The results revealed that overexpression of AGR2 promoted teratoma cell proliferation and invasion and elevated glycolysis levels evidencing by the increase in lactate secretion, glucose consumption, ATP levels and the expression of glycolysis-related proteins, while knockdown of AGR2 showed the opposite results. The interactions between AGR2 and annexin A2 (AnXA2), as well as between AnXA2 and epidermal growth factor receptor (EGFR) were verified by co-immunoprecipitation assay. Mechanistic studies revealed that AGR2 interacts with AnXA2 and increases the level of AnXA2 to recruit more AnXA2 to EGFR, there by promoting EGFR expression. A series of rescue experiments showed that knockdown of AnXA2 or EGFR weakened the promotional effects of AGR2 overexpression on the proliferation, invasion, and glycolysis of teratoma cells. Finally, tumorigenicity assays were performed using NT2-D1 cells stably transfected with either LV-NC-shRNA or LV-shAGR2. The results showed that AGR2 knockdown significantly inhibited teratoma tumor growth in vivo. In conclusion, our data suggested that AGR2 facilitates glycolysis in teratomas through promoting EGFR expression by interacting with AnXA2, thereby promoting teratoma cells proliferation and invasion.

Unraveling pancreatic ductal adenocarcinoma immune prognostic signature through a naive B cell gene set

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), a leading cause of cancer mortality, has a complex pathogenesis involving various immune cells, including B cells and their subpopulations. Despite emerging research on the role of these cells within the tumor microenvironment (TME), the detailed molecular interactions with tumor-infiltrating immune cells (TIICs) are not fully understood.

METHODS

We applied CIBERSORT to quantify TIICs and naive B cells, which are prognostic for PDAC. Marker genes from scRNA-seq and modular genes from weighted gene co-expression network analysis (WGCNA) were integrated to identify naive B cell-related genes. A prognostic signature was constructed utilizing ten machine-learning algorithms, with validation in external cohorts. We further assessed the immune cell diversity, ESTIMATE scores, and immune checkpoint genes (ICGs) between patient groups stratified by risk to clarify the immune landscape in PDAC.

RESULTS

Our analysis identified 994 naive B cell-related genes across single-cell and bulk transcriptomes, with 247 linked to overall survival. We developed a 12-gene prognostic signature using Lasso and plsRcox algorithms, which was confirmed by 10-fold cross-validation and showed robust predictive power in training and real-world cohorts. Notably, we observed substantial differences in immune infiltration between patients with high and low risk.

CONCLUSION

Our study presents a robust prognostic signature that effectively maps the complex immune interactions in PDAC, emphasizing the critical function of naive B cells and suggesting new avenues for immunotherapeutic interventions. This signature has potential clinical applications in personalizing PDAC treatment, enhancing the understanding of immune dynamics, and guiding immunotherapy strategies.

NEDD4 and NEDD4L: Ubiquitin Ligases Closely Related to Digestive Diseases

Protein ubiquitination is an enzymatic cascade reaction and serves as an important protein post-translational modification (PTM) that is involved in the vast majority of cellular life activities. The key enzyme in the ubiquitination process is E3 ubiquitin ligase (E3), which catalyzes the binding of ubiquitin (Ub) to the protein substrate and influences substrate specificity. In recent years, the relationship between the subfamily of neuron-expressed developmental downregulation 4 (NEDD4), which belongs to the E3 ligase system, and digestive diseases has drawn widespread attention. Numerous studies have shown that NEDD4 and NEDD4L of the NEDD4 family can regulate the digestive function, as well as a series of related physiological and pathological processes, by controlling the subsequent degradation of proteins such as PTEN, c-Myc, and P21, along with substrate ubiquitination. In this article, we reviewed the appropriate functions of NEDD4 and NEDD4L in digestive diseases including cell proliferation, invasion, metastasis, chemotherapeutic drug resistance, and multiple signaling pathways, based on the currently available research evidence for the purpose of providing new ideas for the prevention and treatment of digestive diseases.

METTL3-mediated deficiency of lncRNA HAR1A drives non-small cell lung cancer growth and metastasis by promoting ANXA2 stabilization

We previously reported lncRNA HAR1A as a tumor suppressor in non-small cell lung cancer (NSCLC). However, the delicate working mechanisms of this lncRNA remain obscure. Herein, we demonstrated that the ectopic expression of HAR1A inhibited the proliferation, epithelial-mesenchymal transition (EMT), migration, and invasion of NSCLC cells and enhanced paclitaxel (PTX) sensitivity in vitro and in vivo. We identified the oncogenic protein annexin 2 (ANXA2) as a potential interacting patterner of HAR1A. HAR1A overexpression enhanced ANXA2 ubiquitination and accelerated its degradation via the ubiquitin-proteasome pathway. We further uncovered that HAR1A promoted the interaction between E3 ubiquitin ligase TRIM65 and ANXA2. Moreover, the ANXA2 plasmid transfection could reverse HAR1A overexpression-induced decreases in proliferation, migration, and invasion of NSCLC cells and the activity of the NF-κB signaling pathway. Finally, we found that HAR1A loss in NSCLC might be attributed to the upregulated METTL3. The m6A modification levels of HAR1A were increased in cancer cells, while YTHDF2 was responsible for recognizing m6A modification in the HAR1A, leading to the disintegration of this lncRNA. In conclusion, we found that METTL3-mediated m6A modification decreased HAR1A in NSCLC. HAR1A deficiency, in turn, stimulated tumor growth and metastasis by activating the ANXA2/p65 axis.

LINC02086 inhibits ferroptosis and promotes malignant phenotypes of pancreatic cancer via miR-342-3p/CA9 axis

Long noncoding RNAs (lncRNAs) play important roles in modulating the tumorigenesis and progression of malignant tumors. LINC02086 is a newly identified oncogene associated with tumorigenesis, but its role in pancreatic cancer (PC) has not been fully elucidated. In this study we examined the expression levels of LINC02086, miR-342-3p, and CA9 in PC. The relationship of ferroptosis with these factors was analyzed by detecting the expression levels of Fe2+, reactive oxygen species (ROS), and ferroptosis marker proteins. The expression of these genes was altered to observe their effects on cell proliferation, migration, and invasion ability. Bioinformatics was used to predict target genes, and the binding relationship was verified luciferase reporter assay. Finally, the function of LINC02086 was evaluated in vivo. The findings suggest that LINC02086 is highly expressed in PC tissues and cell lines and is correlated with a poor prognosis. In vitro experiments demonstrated that LINC02086 knockdown promoted ferroptosis in PC cells to suppress their malignant phenotype. LINC02086 acts as a competitive endogenous RNA that adsorbed miR-342-3p. miR-342-3p hinders the malignant progression of PC by promoting ferroptosis. In addition, miR-342-3p targets CA9 and affects its function. Further mechanistic studies revealed that LINC02086 inhibits ferroptosis and promotes PC progression by acting as a sponge for miR-342-3p to upregulate CA9 expression. In vivo experiments further confirmed this mechanism. Taken together, LINC02086 upregulates CA9 expression by competitively binding with miR-342-3p, thereby inhibiting ferroptosis in PC cells and promoting their malignant phenotype. The results of our study provide new insights into how LINC02086 contributes to the progression of PC.

Stabilization of MOF (KAT8) by USP10 promotes esophageal squamous cell carcinoma proliferation and metastasis through epigenetic activation of ANXA2/Wnt signaling

Dysregulation of MOF (also known as MYST1, KAT8), a highly conserved H4K16 acetyltransferase, plays important roles in human cancers. However, its expression and function in esophageal squamous cell carcinoma (ESCC) remain unknown. Here, we report that MOF is highly expressed in ESCC tumors and predicts a worse prognosis. Depletion of MOF in ESCC significantly impedes tumor growth and metastasis both in vitro and in vivo, whereas ectopic expression of MOF but not catalytically inactive mutant (MOF-E350Q) promotes ESCC progression, suggesting that MOF acetyltransferase activity is crucial for its oncogenic activity. Further analysis reveals that USP10, a deubiquitinase highly expressed in ESCC, binds to and deubiquitinates MOF at lysine 410, which protects it from proteosome-dependent protein degradation. MOF stabilization by USP10 promotes H4K16ac enrichment in the ANXA2 promoter to stimulate ANXA2 transcription in a JUN-dependent manner, which subsequently activates Wnt/β-Catenin signaling to facilitate ESCC progression. Our findings highlight a novel USP10/MOF/ANXA2 axis as a promising therapeutic target for ESCC.

LncNFYB promotes the proliferation of rheumatoid arthritis fibroblast-like synoviocytes via LncNFYB/ANXA2/ERK1/2 axis

Long noncoding RNAs (lncRNAs) are specifically expressed in different diseases and regulate disease progression. To explore the functions of rheumatoid arthritis (RA)-specific lncRNA, we determined the lncRNA expression profile of fibroblast-like synoviocytes (FLS) obtained from patients with RA and osteoarthritis (OA) using a LncRNA microarray and identified up-regulated LncNFYB in RA as a potential therapeutic target. Using gain- and loss-of-function studies, LncNFYB was proven to promote FLS proliferation and cell cycle progress but not affect their invasion, migration, and apoptotic abilities. Further investigation discovered that LncRNA could combine with annexin A2 (ANXA2) and enhance the level of phospho-ANXA2 (Tyr24) in the plasma membrane area, which induced the activation of ERK1/2 to promote proliferation. These findings provide new insights into the biological functions of LncNFYB on modification of FLS, which may be exploited for the therapy of RA.

LncRNA-MUF: A Novel Oncogenic Star with Potential as a Biological Marker and Therapeutic Target for Gastrointestinal Malignancies

Gastrointestinal (GI) cancers pose a significant global health challenge, characterized by a high incidence and poor prognosis. The delayed detection and occurrence of metastasis contribute to the overall low survival rates associated with these cancers. Therefore, there is an urgent need to identify novel molecular targets for effective GI cancer treatment. Recent research has shed light on the potential of long non-coding RNAs (lncRNAs) as promising targets in cancer therapy, given their strong association with carcinogenesis and profound impact on tumor development. Among these lncRNAs, lncRNA-MUF, also known as LINC00941, has emerged as a key player in oncogenic regulation, specifically implicated in the progression of various GI cancers, including esophageal, gastric, colorectal, hepatic, and pancreatic cancer. This review aims to provide an updated and focused analysis of the regulatory roles of LINC00941 in the initiation and progression of GI cancer. Our objective is to unravel the underlying molecular mechanisms through which LINC00941 influences GI cancer phenotypes both in vivo and in vitro, with a special emphasis on the key molecules and signaling pathways involved. Additionally, LINC00941 has demonstrated clinical significance in terms of clinical pathology, prognosis, and diagnosis in GI tumors, further reinforcing its potential as a novel therapeutic target.

LINC00941: a novel player involved in the progression of human cancers

LINC00941, also known as lncRNA-MUF, is an intergenic non-coding RNA located on chromosome 12p11.21. It actively participates in a complex competing endogenous RNA network, regulating the expression of microRNA and its downstream proteins. Through transcriptional and post-transcriptional regulation, LINC00941 plays a vital role in multiple signaling pathways, influencing cell behaviors such as tumor cell proliferation, epithelial-mesenchymal transition, migration, and invasion. Noteworthy is its consistently high expression in various tumor types, closely correlating with clinicopathological features and cancer prognoses. Elevated LINC00941 levels are associated with adverse clinical outcomes, including increased tumor size, extensive lymphatic metastasis, and distant metastasis, leading to poorer survival rates across different cancers. Additionally, LINC00941 and its associated genes are linked to various targeted drugs available in the market. In this comprehensive review, we systematically summarize existing studies, detailing LINC00941's differential expression, clinicopathological and prognostic implications, regulatory mechanisms, and associated therapeutic drugs. Our analysis includes relevant charts and incorporates bioinformatics analyses to verify LINC00941's differential expression in pan-cancer and explore potential transcriptional regulation patterns of downstream targets. This work not only establishes a robust data foundation but also guides future research directions. Given its potential as a significant cancer biomarker and therapeutic target, further investigation into LINC00941's differential expression and regulatory mechanisms is essential.

Expanding the ubiquitin code in pancreatic cancer

The ubiquitin-proteasome system (UPS) is a fundamental regulatory mechanism in cells, vital for maintaining cellular homeostasis, compiling signaling transduction, and determining cell fates. These biological processes require the coordinated signal cascades of UPS members, including ubiquitin ligases, ubiquitin-conjugating enzymes, deubiquitinases, and proteasomes, to ubiquitination and de-ubiquitination on substrates. Recent studies indicate that ubiquitination code rewriting is particularly prominent in pancreatic cancer. High frequency mutation or aberrant hyperexpression of UPS members dysregulates ferroptosis, tumor microenvironment, and metabolic rewiring processes and contribute to tumor growth, metastasis, immune evasion, and acquired drug resistance. We conduct an in-depth overview of ubiquitination process in pancreatic cancer, highlighting the role of ubiquitin code in tumor-promoting and tumor-suppressor pathways. Furthermore, we review current UPS modulators and analyze the potential of UPS modulators as cancer therapy.

Stage analysis of pancreatic ductal adenocarcinoma via network analysis

Aim

This study aimed to introduce a biomarker panel to detect pancreatic ductal adenocarcinoma (PDAC) in the early stage, and also differentiate of stages from each other.

Background

PDAC is a lethal cancer with poor prognosis and overall survival.

Methods

Gene expression profiles of PDAC patients were extracted from the Gene Expression Omnibus (GEO) database. The genes that were significantly differentially expressed (DEGs) for Stages I, II, and III in comparison to the healthy controls were identified. The determined DEGs were assessed via protein-protein interaction (PPI) network analysis, and the hub-bottleneck nodes of analyzed networks were introduced.

Results

A number of 140, 874, and 1519 significant DEGs were evaluated via PPI network analysis. A biomarker panel including ALB, CTNNB1, COL1A1, POSTN, LUM, and ANXA2 is presented as a biomarker panel to detect PDAC in the early stage. Two biomarker panels are suggested to recognize other stages of illness.

Conclusion

It can be concluded that ALB, CTNNB1, COL1A1, POSTN, LUM, and ANXA2 and also FN1, HSP90AA1, LOX, ANXA5, SERPINE1, and WWP2 beside GAPDH, AKT1, EGF, CASP3 are suitable sets of gene to separate stages of PDAC.

NEDD4L in human tumors: regulatory mechanisms and dual effects on anti-tumor and pro-tumor

Tumorigenesis and tumor development are closely related to the abnormal regulation of ubiquitination. Neural precursor cell expressed developmentally downregulated 4-like (NEDD4L), an E3 ubiquitin ligase critical to the ubiquitination process, plays key roles in the regulation of cancer stem cells, as well as tumor cell functions, including cell proliferation, apoptosis, cell cycle regulation, migration, invasion, epithelial-mesenchymal transition (EMT), and tumor drug resistance, by controlling subsequent protein degradation through ubiquitination. NEDD4L primarily functions as a tumor suppressor in several tumors but also plays an oncogenic role in certain tumors. In this review, we comprehensively summarize the relevant signaling pathways of NEDD4L in tumors, the regulatory mechanisms of its upstream regulatory molecules and downstream substrates, and the resulting functional alterations. Overall, therapeutic strategies targeting NEDD4L to treat cancer may be feasible.

The human long non-coding RNA LINC00941 and its modes of action in health and disease

Long non-coding RNAs have gained attention in recent years as they were shown to play crucial roles in the regulation of cellular processes, but the understanding of the exact mechanisms is still incomplete in most cases. This is also true for long non-coding RNA LINC00941, which was recently found to be highly upregulated in various types of cancer influencing cell proliferation and metastasis. Initial studies could not elucidate the mode of action to understand the role and real impact of LINC00941 in tissue homeostasis and cancer development. However, recent analyses have demonstrated multiple potential modes of action of LINC00941 influencing the functionality of various cancer cell types. Correspondingly, LINC00941 was proposed to be involved in regulation of mRNA transcription and modulation of protein stability, respectively. In addition, several experimental approaches suggest a function of LINC00941 as competitive endogenous RNA, thus acting in a post-transcriptional regulatory fashion. This review summarizes our recent knowledge about the mechanisms of action of LINC00941 elucidated so far and discusses its putative role in miRNA sequestering processes. In addition, the functional role of LINC00941 in regulating human keratinocytes is discussed to also highlight its role in normal tissue homeostasis tissue aside from its involvement in cancer.

Unraveling the Complex Web of Mechanistic Regulation of Versatile NEDD4 Family by Non-Coding RNAs in Carcinogenesis and Metastasis: From Cell Culture Studies to Animal Models

Discoveries related to an intriguing feature of ubiquitination have prompted a detailed analysis of the ubiquitination patterns in malignant cells. How the "ubiquitinome" is reshaped during multistage carcinogenesis has garnered significant attention. Seminal studies related to the structural and functional characterization of NEDD4 (Neuronal precursor cell-expressed developmentally downregulated-4) have consolidated our understanding at a new level of maturity. Additionally, regulatory roles of non-coding RNAs have further complicated the complex interplay between non-coding RNAs and the members of NEDD4 family. These mechanisms range from the miRNA-mediated targeting of NEDD4 family members to the regulation of transcriptional factors for a broader range of non-coding RNAs. Additionally, the NEDD4-mediated degradation of different proteins is modulated by lncRNAs and circRNAs. The miRNA-mediated targeting of NEDD4 family members is also regulated by circRNAs. Tremendous advancements have been made in the identification of different substrates of NEDD4 family and in the comprehensive analysis of the molecular mechanisms by which various members of NEDD4 family catalyze the ubiquitination of substrates. In this review, we have attempted to summarize the multifunctional roles of the NEDD4 family in cancer biology, and how different non-coding RNAs modulate these NEDD4 family members in the regulation of cancer. Future molecular studies should focus on the investigation of a broader drug design space and expand the scope of accessible targets for the inhibition/prevention of metastasis.

Molecular and metabolic regulation of immunosuppression in metastatic pancreatic ductal adenocarcinoma

Immunosuppression is a hallmark of pancreatic ductal adenocarcinoma (PDAC), contributing to early metastasis and poor patient survival. Compared to the localized tumors, current standard-of-care therapies have failed to improve the survival of patients with metastatic PDAC, that necessecitates exploration of novel therapeutic approaches. While immunotherapies such as immune checkpoint blockade (ICB) and therapeutic vaccines have emerged as promising treatment modalities in certain cancers, limited responses have been achieved in PDAC. Therefore, specific mechanisms regulating the poor response to immunotherapy must be explored. The immunosuppressive microenvironment driven by oncogenic mutations, tumor secretome, non-coding RNAs, and tumor microbiome persists throughout PDAC progression, allowing neoplastic cells to grow locally and metastasize distantly. The metastatic cells escaping the host immune surveillance are unique in molecular, immunological, and metabolic characteristics. Following chemokine and exosomal guidance, these cells metastasize to the organ-specific pre-metastatic niches (PMNs) constituted by local resident cells, stromal fibroblasts, and suppressive immune cells, such as the metastasis-associated macrophages, neutrophils, and myeloid-derived suppressor cells. The metastatic immune microenvironment differs from primary tumors in stromal and immune cell composition, functionality, and metabolism. Thus far, multiple molecular and metabolic pathways, distinct from primary tumors, have been identified that dampen immune effector functions, confounding the immunotherapy response in metastatic PDAC. This review describes major immunoregulatory pathways that contribute to the metastatic progression and limit immunotherapy outcomes in PDAC. Overall, we highlight the therapeutic vulnerabilities attributable to immunosuppressive factors and discuss whether targeting these molecular and immunological "hot spots" could improve the outcomes of PDAC immunotherapies.

FBXW10-S6K1 promotes ANXA2 polyubiquitination and KRAS activation to drive hepatocellular carcinoma development in males

The incidence rate of human hepatocellular carcinoma (HCC) is approximately three times higher in males than in females. A better understanding of the mechanisms underlying HCC development in males could lead to more effective therapies for HCC. Our previous study found that FBXW10 played a critical role in promoting HCC development in male mice and patients, but the mechanism remains unknown. Here, we found that FBXW10 promoted K63-linked ANXA2 polyubiquitination and activation in HCC tissues from males, and this process was required for S6K1-mediated phosphorylation. Activated ANXA2 further translocated from the cytoplasm to the cell membrane to bind KRAS and then activated the MEK/ERK pathway, leading to HCC proliferation and lung metastasis. Interfering with ANXA2 significantly blocked FBXW10-driven HCC growth and lung metastasis in vitro and in vivo. Notably, membrane ANXA2 was upregulated and positively correlated with FBXW10 expression in male HCC patients. These findings offer new insights into the regulation and function of FBXW10 signaling in HCC tumorigenesis and metastasis and suggest that the FBXW10-S6K1-ANXA2-KRAS-ERK axis may serve as a potential biomarker and therapeutic target in male HCC patients with high FBXW10 expression.

METTL14 Facilitates the Metastasis of Pancreatic Carcinoma by Stabilizing LINC00941 in an m6A-IGF2BP2-Dependent Manner

Pancreatic adenocarcinoma (PC), one of the most fatal diseases, usually generates a poor prognosis in advanced stages. N6-methyladenosine modification has emerged as a crucial participant in tumor development and recurrence. Methyltransferase-like 14 (METTL14), as a core member of methyltransferases, is involved in tumor progression and metastasis. However, the potential mechanism by which METTL14 regulates long noncoding RNAs (lncRNAs) in PC remains unclear. RNA immunoprecipitation (RIP), methylated RNA immunoprecipitation quantitative PCR (MeRIP-qPCR), and fluorescence in situ hybridization (FISH) were used to explore the underlying mechanisms. In our study, we found that METTL14 expression was upregulated in PC patients, and was associated with poor prognosis. In vitro and in vivo experiments, knocking down METTL14 suppressed tumor metastasis. RNA-seq and bioinformatics analyses were used to identify LINC00941 as the downstream target of METTL14. Mechanistically, LINC00941 was upregulated by METTL14 in an m6A-dependent way. LINC00941 was recruited and recognized by IGF2BP2. METTL14 enhanced the affinity of IGF2BP2 for LINC00941, while IGF2BP2 promoted the stabilization of LINC00941, which contributed to the migration and invasion of PC cells. Overall, our research revealed that METTL14 promoted the metastasis of PC through m6A modification of LINC00941. Targeting the METTL14-LINC00941-IGF2BP2 axis may provide promising therapeutic approaches for PC.

Regulatory Functions and Mechanisms of Circular RNAs in Hepatic Stellate Cell Activation and Liver Fibrosis

Chronic liver injury induces the activation of hepatic stellate cells (HSCs) into myofibroblasts, which produce excessive amounts of extracellular matrix (ECM), resulting in tissue fibrosis. If the injury persists, these fibrous scars could be permanent and disrupt liver architecture and function. Currently, effective anti-fibrotic therapies are lacking; hence, understanding molecular mechanisms that control HSC activation could hold a key to the development of new treatments. Recently, emerging studies have revealed roles of circular RNAs (circRNAs), a class of non-coding RNAs that was initially assumed to be the result of splicing errors, as new regulators in HSC activation. These circRNAs can modulate the activity of microRNAs (miRNAs) and their interacting protein partners involved in regulating fibrogenic signaling cascades. In this review, we will summarize the current knowledge of this class of non-coding RNAs for their molecular function in HSC activation and liver fibrosis progression.