Identification and Validation of Glycosylation-Related Genes in Obesity and MASH: Insights from Human Liver Samples and a High-Fat Diet Mouse Model.

Background: Obesity is reaching epidemic proportions in the developed world. The biosynthesis and degradation of human glycoproteins take place at the highest level in the liver. However, the association between glycosylation and the factors affecting obesity and metabolism-associated steatohepatitis (MASH) is still unclear. Materials and Methods: Gene expression data of liver samples from obese patients were retrieved from GSE83452 and GSE89632 databases. Difference analysis and machine learning were used to identify hub genes involved in glycosylation and associated with the response of weight loss treatment. A total of 7 glycosylation-related hub genes were identified and then subjected to correlation analysis, immune cells infiltration analysis and ROC (Receiver Operating Characteristic) analysis. We also evaluated the potential function of 7 hub genes in obesity patients. MASH mice were used to validate the glycosylation-related hub genes. Results: A total of 25 overlapped glycosylation-related genes were identified by DEGs analysis. ACER2, STX17, ARF5, GPC4, ENTPD5, NANP, and DPY19L2 were identified as hub genes. Among these hub genes, ACER2, STX17, ARF5, and ENTPD5 were also differential expressed in MASH patients. ENTPD5 showed increased transcription in obese MASH mice. Conclusion: The current study identified seven glycosylation-related genes, ACER2, STX17, ARF5, GPC4, ENTPD5, NANP, and DPY19L2, that might play key roles in the development of obesity. ENTPD5 might play a key role in the development of MASH. These findings provide fresh perspectives for expanding the investigation of obesity and MASH.

BTLA deficiency promotes HSC activation and protects against hepatic ischemia-reperfusion injury.

BACKGROUND AND AIMS: Hepatic ischemia-reperfusion injury (IRI) is unavoidable even despite the development of more effective surgical approaches. During hepatic IRI, activated HSC (aHSC) are involved in liver injury and recovery. APPROACH AND RESULT: A proportion of aHSC increased significantly both in the mouse liver tissues with IRI and in the primary mouse HSCs and LX-2 cells during hypoxia-reoxygenation. "Loss-of-function" experiments revealed that depleting aHSC with gliotoxin exacerbated liver damage in IRI mice. Subsequently, we found that the transcription of mRNA and the expression of B and T lymphocyte attenuator (BTLA) protein were lower in aHSC compared with quiescent HSCs. Interestingly, overexpression or knockdown of BTLA resulted in opposite changes in the activation of specific markers for HSCs such as collagen type I alpha 1, α-smooth muscle actin, and Vimentin. Moreover, the upregulation of these markers was also observed in the liver tissues of global BLTA-deficient (BTLA-/-) mice and was higher after hepatic IRI. Compared with wild-type mice, aHSC were higher, and liver injury was lower in BTLA-/- mice following IRI. However, the depletion of aHSC reversed these effects. In addition, the depletion of aHSC significantly exacerbated liver damage in BTLA-/- mice with hepatic IRI. Furthermore, the TGF-ß1 signaling pathway was identified as a potential mechanism for BTLA to negatively regulate the activation of HSCs in vivo and in vitro. CONCLUSIONS: These novel findings revealed a critical role of BTLA. Particularly, the receptor inhibits HSC-activated signaling in acute IRI, implying that it is a potential immunotherapeutic target for decreasing the IRI risk.

ACLS4 could be a potential therapeutic target for severe acute pancreatitis.

Acute pancreatitis (AP) is currently among the most prevalent digestive diseases. The pathogenesis of AP remains elusive, and there is no specific treatment. Therefore, identifying novel therapeutic targets is imperative for effective management and prevention of AP. In this study, we conducted a comprehensive transcriptomic analysis of peripheral blood from patients with AP and the pancreatic tissue from a mouse model of AP. Our analyses revealed that mouse model of AP exhibited a higher enrichment of mitogen-activated protein kinase signaling, endocytosis, apoptosis and tight junction pathways than the control. Subsequent weighted gene co-expression network analysis identified 15 gene modules, containing between 50 and 1000 genes each, which demonstrated significant correlations within samples from patients with AP. Further screening identified four genes (ACSL4, GALNT3, WSB1, and IL1R1) that were significantly upregulated in severe acute pancreatitis (SAP) in both human and mouse samples. In mouse models of SAP, ACSL4 was significantly upregulated in the pancreas, whereas GALNT3, WSB1, and IL1R1 were not. Lastly, we found that a commercially available ACSL4 inhibitor, PRGL493, markedly reduced IL-6 and TNFα expression, alleviated pancreatic edema and necrosis, and diminished the infiltration of inflammatory cells. In conclusion, this study comprehensively depicts the key genes and signaling pathways implicated in AP and suggests the potential of ACSL4 as a novel therapeutic target for SAP. These findings provide valuable insights for further exploration of therapeutic strategies for SAP.

Hepatocyte-specific loss of DDB1 attenuates hepatic steatosis but aggravates liver inflammation and fibrosis in MASH.

BACKGROUND: MASH is a common clinical disease that can lead to advanced liver conditions, but no approved pharmacotherapies are available due to an incomplete understanding of its pathogenesis. Damaged DNA binding protein 1 (DDB1) participates in lipid metabolism. Nevertheless, the function of DDB1 in MASH is unclear. METHODS: Clinical liver samples were obtained from patients with MASH and control individuals by liver biopsy. Hepatocyte-specific Ddb1-knockout mice and liver Hmgb1 knockdown mice were fed with a methionine-and choline-deficient diet to induce MASH. RESULTS: We found that the expression of DDB1 in the liver was significantly decreased in MASH models. Hepatocyte-specific ablation of DDB1 markedly alleviated methionine-and choline-deficient diet-induced liver steatosis but unexpectedly exacerbated inflammation and fibrosis. Mechanistically, DDB1 deficiency attenuated hepatic steatosis by downregulating the expression of lipid synthesis and uptake genes. We identified high-mobility group box 1 as a key candidate target for DDB1-mediated liver injury. DDB1 deficiency upregulated the expression and extracellular release of high-mobility group box 1, which further increased macrophage infiltration and activated HSCs, ultimately leading to the exacerbation of liver inflammation and fibrosis. CONCLUSIONS: These data demonstrate the independent regulation of hepatic steatosis and injury in MASH. These findings have considerable clinical implications for the development of therapeutic strategies for MASH.

Correction of severe upper-eyelid sunken deformity in Asians by double-eyelid procedure and combination of orbital fat pad repositioning and autologous fat transplantation: a one-year follow-up study of 79 cases.

Background: Nowadays, people's pace of life continues to rapid up, and many bad habits will accelerate the aging of the eye periphery, and patients with sunken upper eyelids are to be found in younger people. In young Asians, single eyelids are often accompanied by upper eyelid depression, so correcting the upper eyelid depression during blepharoplasty becomes a higher challenge for plastic surgeons. Current surgical methods for upper eyelid depression include three major categories: tissue repositioning, injection and filling, and combined use. According to grades 1 and 2 are mild or moderate upper eyelid sunken. The sunken can be well corrected only by repositioning the orbital fat pad, while the correction effect for severe upper eyelid sunken in grades 3 and 4 is Poor, need to be used in combination to achieve the desired effect. Purpose: The authors sought to determine whether, for patients with single eyelids and severe upper eyelid depression of grades 3 and 4, combined with orbital fat pad repositioning and autologous fat transplantation during blepharoplasty, an aesthetic and youthful blepharoplasty can be achieved. Methods: This study included 79 patients with single eyelids and severe upper eyelid depression of grades 3 and 4 who received treatment between June 2020 and July 2022. All patients underwent double eyelid surgery plus orbital fat repositioning and autologous fat grafting. Results: After a minimum follow-up period of 1 year, overall patient satisfaction was 92%. The recurrence rate within the first year was 6% and the complication rate was 5%. Conclusion: This combined surgery may be an option for young Asians with single eyelids and severe upper eyelid depression. In this study, the surgery resulted in natural-looking double eyelids and younger-looking eye sockets in most patients. A combination of different surgical methods based on the patient's preoperative condition is critical to achieving long-term correction.

Lipid metabolism in tumor-infiltrating regulatory T cells: perspective to precision immunotherapy.

Regulatory T cells (Tregs) are essential to the negative regulation of the immune system, as they avoid excessive inflammation and mediate tumor development. The abundance of Tregs in tumor tissues suggests that Tregs may be eliminated or functionally inhibited to stimulate antitumor immunity. However, immunotherapy targeting Tregs has been severely hampered by autoimmune diseases due to the systemic elimination of Tregs. Recently, emerging studies have shown that metabolic regulation can specifically target tumor-infiltrating immune cells, and lipid accumulation in TME is associated with immunosuppression. Nevertheless, how Tregs actively regulate metabolic reprogramming to outcompete effector T cells (Teffs), and how lipid metabolic reprogramming contributes to the immunomodulatory capacity of Tregs have not been fully discussed. This review will discuss the physiological processes by which lipid accumulation confers a metabolic advantage to tumor-infiltrating Tregs (TI-Tregs) and amplifies their immunosuppressive functions. Furthermore, we will provide a summary of the driving effects of various metabolic regulators on the metabolic reprogramming of Tregs. Finally, we propose that targeting the lipid metabolism of TI-Tregs could be efficacious either alone or in conjunction with immune checkpoint therapy.

HBV PreC interacts with SUV39H1 to induce viral replication by blocking the proteasomal degradation of viral polymerase.

Hepatitis B e antigen (HBeAg) seropositivity during the natural history of chronic hepatitis B (CHB) is known to coincide with significant increases in serum and intrahepatic HBV DNA levels. However, the precise underlying mechanism remains unclear. In this study, we found that PreC (HBeAg precursor) genetic ablation leads to reduced viral replication both in vitro and in vivo. Furthermore, PreC impedes the proteasomal degradation of HBV polymerase, promoting viral replication. We discovered that PreC interacts with SUV39H1, a histone methyltransferase, resulting in a reduction in the expression of Cdt2, an adaptor protein of CRL4 E3 ligase targeting HBV polymerase. SUV39H1 induces H3K9 trimethylation of the Cdt2 promoter in a PreC-induced manner. CRISPR-mediated knockout of endogenous SUV39H1 or pharmaceutical inhibition of SUV39H1 decreases HBV loads in the mouse liver. Additionally, genetic depletion of Cdt2 in the mouse liver abrogates PreC-related HBV replication. Interestingly, a negative correlation of intrahepatic Cdt2 with serum HBeAg and HBV DNA load was observed in CHB patient samples. Our study thus sheds light on the mechanistic role of PreC in inducing HBV replication and identifies potential therapeutic targets for HBV treatment.

Cancer-derived exosomes as novel biomarkers in metastatic gastrointestinal cancer.

Gastrointestinal cancer (GIC) is the most prevalent and highly metastatic malignant tumor and has a significant impact on mortality rates. Nevertheless, the swift advancement of contemporary technology has not seamlessly aligned with the evolution of detection methodologies, resulting in a deficit of innovative and efficient clinical assays for GIC. Given that exosomes are preferentially released by a myriad of cellular entities, predominantly originating from neoplastic cells, this confers exosomes with a composition enriched in cancer-specific constituents. Furthermore, exosomes exhibit ubiquitous presence across diverse biological fluids, endowing them with the inherent advantages of non-invasiveness, real-time monitoring, and tumor specificity. The unparalleled advantages inherent in exosomes render them as an ideal liquid biopsy biomarker for early diagnosis, prognosticating the potential development of GIC metastasis.In this review, we summarized the latest research progress and possible potential targets on cancer-derived exosomes (CDEs) in GIC with an emphasis on the mechanisms of exosome promoting cancer metastasis, highlighting the potential roles of CDEs as the biomarker and treatment in metastatic GIC.

Adavosertib-encapsulated metal-organic frameworks for p53-mutated gallbladder cancer treatment via synthetic lethality.

Adavosertib (ADA) is a WEE1 inhibitor that exhibits a synthetic lethal effect on p53-mutated gallbladder cancer (GBC). However, drug resistance due to DNA damage response compensation pathways and high toxicity limits further applications. Herein, estrone-targeted ADA-encapsulated metal-organic frameworks (ADA@MOF-EPL) for GBC synthetic lethal treatment by inducing conditional factors are developed. The high expression of estrogen receptors in GBC enables ADA@MOF-EPL to quickly enter and accumulate near the cell nucleus through estrone-mediated endocytosis and release ADA to inhibit WEE1 upon entering the acidic tumor microenvironment. Ultrasound irradiation induces ADA@MOF-EPL to generate reactive oxygen species (ROS), which leads to a further increase in DNA damage, resulting in a higher sensitivity of p53-mutated cancer cells to WEE1 inhibitor and promoting cell death via conditional synthetic lethality. The conditional factor induced by ADA@MOF-EPL further enhances the antitumor efficacy while significantly reducing systemic toxicity. Moreover, ADA@MOF-EPL demonstrates similar antitumor abilities in other p53-mutated solid tumors, revealing its potential as a broad-spectrum antitumor drug.

A multicenter clinical AI system study for detection and diagnosis of focal liver lesions.

Early and accurate diagnosis of focal liver lesions is crucial for effective treatment and prognosis. We developed and validated a fully automated diagnostic system named Liver Artificial Intelligence Diagnosis System (LiAIDS) based on a diverse sample of 12,610 patients from 18 hospitals, both retrospectively and prospectively. In this study, LiAIDS achieved an F1-score of 0.940 for benign and 0.692 for malignant lesions, outperforming junior radiologists (benign: 0.830-0.890, malignant: 0.230-0.360) and being on par with senior radiologists (benign: 0.920-0.950, malignant: 0.550-0.650). Furthermore, with the assistance of LiAIDS, the diagnostic accuracy of all radiologists improved. For benign and malignant lesions, junior radiologists' F1-scores improved to 0.936-0.946 and 0.667-0.680 respectively, while seniors improved to 0.950-0.961 and 0.679-0.753. Additionally, in a triage study of 13,192 consecutive patients, LiAIDS automatically classified 76.46% of patients as low risk with a high NPV of 99.0%. The evidence suggests that LiAIDS can serve as a routine diagnostic tool and enhance the diagnostic capabilities of radiologists for liver lesions.

S100A6 drives lymphatic metastasis of liver cancer via activation of the RAGE/NF-kB/VEGF-D pathway.

Patients diagnosed with lymph node (LN) metastatic liver cancer face an exceedingly grim prognosis. In-depth analysis of LN metastatic patients' characteristics and tumor cells' interactions with human lymphatic endothelial cells (HLECs), can provide important biological and therapeutic insights. Here we identify at the single-cell level that S100A6 expression differs between primary tumor and their LN metastasis. Of particular significance, we uncovered the disparity in S100A6 expression between tumors and normal tissues is greater in intrahepatic cholangiocarcinoma (ICC) patients, frequently accompanied by LN metastases, than that in hepatocellular carcinoma (HCC), with rare occurrence of LN metastasis. Furthermore, in the infrequent instances of LN metastasis in HCC, heightened S100A6 expression was observed, suggesting a critical role of S100A6 in the process of LN metastasis. Subsequent experiments further uncovered that S100A6 secreted from tumor cells promotes lymphangiogenesis by upregulating the expression and secretion of vascular endothelial growth factor-D (VEGF-D) in HLECs through the RAGE/NF-kB/VEGF-D pathway while overexpression of S100A6 in tumor cells also augmented their migration and invasion. Taken together, these data reveal the dual effects of S100A6 in promoting LN metastasis in liver cancer, thus highlighting its potential as a promising therapeutic target.

Potential of lncRNAs to regulate cuproptosis in hepatocellular carcinoma: Establishment and validation of a novel risk model.

Cuproptosis, a distinct form of programmed cell death, is an emerging field in oncology with promising implications. This novel mode of cell death has the potential to become a regulatory target for tumor therapy, thus expanding the currently limited treatment options available for patients with cancer. Our research team focused on investigating the role of functional long non-coding RNA (lncRNAs) in hepatocellular carcinoma (HCC). We were particularly intrigued by the potential implications of HCC-lncRNAs on cuproptosis. Through a comprehensive analysis, we identified three cuproptosis-related lncRNAs (CRLs): AC018690.1, AL050341.2, and LINC02038. These lncRNAs were found to influence the sensitivity of HCC to cuproptosis. Based on our results, we constructed a risk model represented by the equation: risk score = 0.82 * AC018690.1 + 0.65 * AL050341.2 + 0.61 * LINC02038. Notably, significant disparities were observed in clinical features, such as the response rate to immunotherapy and targeted therapy, as well as in cellular characteristics, including the composition of the tumor immune microenvironment (TIME), when comparing the high- and low-risk groups. Most importantly, knockdown of these CRLs was confirmed to significantly weaken the resistance to cuproptosis in HCC. This effect resulted from the accelerated accumulation of lipoacylated-DLAT and lipoacylated-DLST. In summary, we identified three CRLs in HCC and established a novel risk model with potential clinical applications. Additionally, we proposed a potential therapeutic method consisting of sorafenib-copper ionophores-immunotherapy.

A Mammalian Conserved Circular RNA CircLARP1B Regulates Hepatocellular Carcinoma Metastasis and Lipid Metabolism.

Circular RNAs (circRNAs) have emerged as crucial regulators in physiology and human diseases. However, evolutionarily conserved circRNAs with potent functions in cancers are rarely reported. In this study, a mammalian conserved circRNA circLARP1B is identified to play critical roles in hepatocellular carcinoma (HCC). Patients with high circLARP1B levels have advanced prognostic stage and poor overall survival. CircLARP1B facilitates cellular metastatic properties and lipid accumulation through promoting fatty acid synthesis in HCC. CircLARP1B deficient mice exhibit reduced metastasis and less lipid accumulation in an induced HCC model. Multiple lines of evidence demonstrate that circLARP1B binds to heterogeneous nuclear ribonucleoprotein D (HNRNPD) in the cytoplasm, and thus affects the binding of HNRNPD to sensitive transcripts including liver kinase B1 (LKB1) mRNA. This regulation causes decreased LKB1 mRNA stability and lower LKB1 protein levels. Antisense oligodeoxynucleotide complementary to theHNRNPD binding sites in circLARP1B increases the HNRNPD binding to LKB1 mRNA. Through the HNRNPD-LKB1-AMPK pathway, circLARP1B promotes HCC metastasis and lipid accumulation. Results from AAV8-mediated hepatocyte-directed knockdown of circLARP1B or Lkb1 in mouse models also demonstrate critical roles of hepatocytic circLARP1B regulatory pathway in HCC metastasis and lipid accumulation, and indicate that circLARP1B may be potential target of HCC treatment.

cDCBLD2 mediates sorafenib resistance in hepatocellular carcinoma by sponging miR-345-5p binding to the TOP2A coding sequence.

Sorafenib is a first-line chemotherapy drug for treating advanced hepatocellular carcinoma (HCC). However, its therapeutic effect has been seriously affected by the emergence of sorafenib resistance in HCC patients. The underlying mechanism of sorafenib resistance is unclear. Here, we report a circular RNA, cDCBLD2, which plays an important role in sorafenib resistance in HCC. We found that cDCBLD2 was upregulated in sorafenib-resistant (SR) HCC cells, and knocking down cDCBLD2 expression could significantly increase sorafenib-related cytotoxicity. Further evidence showed that cDCBLD2 can bind to microRNA (miR)-345-5p through a competing endogenous RNA mechanism, increase type IIA topoisomerase (TOP2A) mRNA stability through a miRNA sponge mechanism, and reduce the effects of sorafenib treatment on HCC by inhibiting apoptosis. Our findings also suggest that miR-345-5p can negatively regulate TOP2A levels by binding to the coding sequence region of its mRNA. Additionally, targeting cDCBLD2 by injecting a specific small interfering RNA (siRNA) could significantly overcome sorafenib resistance in a patient-derived xenograft (PDX) mouse model of HCC. Taken together, our study provides a proof-of-concept for a potential strategy to overcome sorafenib resistance in HCC patients by targeting cDCBLD2 or TOP2A.

Pre-activated nanoparticles with persistent luminescence for deep tumor photodynamic therapy in gallbladder cancer.

Phototherapy of deep tumors still suffers from many obstacles, such as limited near-infrared (NIR) tissue penetration depth and low accumulation efficiency within the target sites. Herein, stimuli-sensitive tumor-targeted photodynamic nanoparticles (STPNs) with persistent luminescence for the treatment of deep tumors are reported. Purpurin 18 (Pu18), a porphyrin derivative, is utilized as a photosensitizer to produce persistent luminescence in STPNs, while lanthanide-doped upconversion nanoparticles (UCNPs) exhibit bioimaging properties and possess high photostability that can enhance photosensitizer efficacy. STPNs are initially stimulated by NIR irradiation before intravenous administration and accumulate at the tumor site to enter the cells through the HER2 receptor. Due to Pu18 afterglow luminescence properties, STPNs can continuously generate ROS to inhibit NFκB nuclear translocation, leading to tumor cell apoptosis. Moreover, STPNs can be used for diagnostic purposes through MRI and intraoperative NIR navigation. STPNs exceptional antitumor properties combined the advantages of UCNPs and persistent luminescence, representing a promising phototherapeutic strategy for deep tumors.

Global trends in research of mitophagy in liver diseases over past two decades: A bibliometric analysis.

Increasing evidence indicated that mitophagy might play a crucial role in the occurrence and progression of liver diseases. In order to enhance our understanding of the intricate relationship between mitophagy and liver diseases, a comprehensive bibliometric analysis of the existing literature in this field was conducted. This analysis aimed to identify key trends, potential areas of future research, and forecast the development of this specific field. We systematically searched the Web of Science Core Collection (WoSCC) for publications related to mitophagy in liver diseases from 2000 to 2022. We conducted the bibliometric analysis and data visualization through VOSviewer and CiteSpace. The analysis of publication growth revealed a substantial increase in articles published in this field over the past years, indicating mitophagy's growing interest and significance in liver diseases. China and USA emerged as the leading contributors in the number of papers, with 294 and 194 independent papers, respectively. Exploring the mechanism of mitophagy in the initiation and procession of liver diseases was the main content of studies in this field, and Parkin-independent mediated mitophagy has attracted much attention recently. "Lipid metabolism," "cell death," "liver fibrosis" and "oxidative stress" were the primary keywords clusters. Additionally, "nlrp3 inflammasome", "toxicity" and "nonalcoholic steatohepatitis" were emerging research hotspots in this area and have the potential to continue to be focal areas of investigation in the future. This study represents the first systematic bibliometric analysis of research on mitophagy in liver diseases conducted over the past 20 years. By providing an overview of the existing literature and identifying current research trends, this analysis sheds light on the critical areas of investigation and paves the way for future studies in this field.

Cytoskeleton remodeling mediated by circRNA-YBX1 phase separation suppresses the metastasis of liver cancer.

Metastasis, especially intrahepatic, is a major challenge for hepatocellular carcinoma (HCC) treatment. Cytoskeleton remodeling has been identified as a vital process mediating intrahepatic spreading. Previously, we reported that HCC tumor adhesion and invasion were modulated by circular RNA (circRNA), which has emerged as an important regulator of various cellular processes and has been implicated in cancer progression. Here, we uncovered a nuclear circRNA, circASH2, which is preferentially lost in HCC tissues and inhibits HCC metastasis by altering tumor cytoskeleton structure. Tropomyosin 4 (TPM4), a critical binding protein of actin, turned out to be the major target of circASH2 and was posttranscriptionally suppressed. Such regulation is based on messenger RNA (mRNA)/precursormRNA splicing and degradation process. Furthermore, liquid-liquid phase separation of nuclear Y-box binding protein 1 (YBX1) enhanced by circASH2 augments TPM4 transcripts decay. Together, our data have revealed a tumor-suppressive circRNA and, more importantly, uncovered a fine regulation mechanism for HCC progression.

Silencing of AJAP1 expression by promoter methylation activates the Wnt/ß-catenin signaling pathway to promote tumor proliferation and metastasis in salivary adenoid cystic carcinoma.

Background: Salivary adenoid cystic carcinoma (SACC) is a unique malignant tumor of the salivary gland with poor prognosis, which is not effective with chemotherapy and targeted drugs. Therefore, it is important to explore the molecular mechanism underlying SACC invasion and metastasis to develop novel therapeutic strategies and targets in clinical research. Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) and western blot (WB) were performed to detect the expression of Adherens Junctions Associated Protein 1 (AJAP1). Methylation-specific PCR was used to evaluate the methylation of the AJAP1 promoter. AJAP1 was overexpressed or knocked down by lentivirus-mediated transfection. Kaplan-Meier analysis was conducted to create a survival curve and the log-rank test was used to analyze the overall survival (OS). The prognostic correlation was assessed using univariate and multivariate Cox regression analyses. Co-immunoprecipitation (Co-IP) was utilized to pull down the possible binding protein of AJAP1 and laser scanning confocal microscopy was applied to detect the subcellular localization of AJAP1, E-cadherin, and ß-catenin. Cell viability, colony formation, wound healing, and Transwell invasion assays were performed to evaluate the function of AJAP1 in vitro. A subcutaneous xenograft assay in nude mice was performed to verify the function of AJAP1 in vivo. Results: AJAP1 was downregulated in SACC tumors and was closely related to SACC lymph node/distant metastasis, which was an independent risk factor for SACC prognosis. Methylation-specific PCR confirmed that high methylation of the AJAP1 promoter was the main cause of its silencing. Overexpression or knockdown of AJAP1 in SACC cells could significantly inhibit or promote the proliferation, invasion, and metastasis of SACC cells, respectively, in both the in vitro and in vivo experiments. Mechanically, we found that AJAP1 binds to E-cadherin and ß-catenin to form a complex in cytomembrane, reducing the nuclear translocation of ß-catenin and blocking the Wingless/Integrated/ß-catenin (Wnt/ß-catenin) signaling pathway to play a suppressive role in cancer. Conclusions: In conclusion, these results suggest that the downregulation of AJAP1 protein expression may play a certain role in progression and metastasis of SACC. Our study indicates that AJAP1 may be a potential prognostic molecular marker and therapeutic target for SACC.