Enhancement of DEN-induced liver tumourigenesis in hepatocyte-specific Lass2-knockout mice coincident with upregulation of the TGF-β1-Smad4-PAI-1 axis

LASS2 suppresses metastasis in multiple cancers by regulating the ferroptosis signalling pathway through interaction with TFRC

BACKGROUND

As a key enzyme in ceramide synthesis, longevity assurance homologue 2 (LASS2) has been indicated to act as a tumour suppressor in a variety of cancers. Ferroptosis is involved in a variety of tumour processes; however, the role of LASS2 in regulating ferroptosis has yet to be explored. This article explores the potential underlying mechanisms involved.

METHODS

Bioinformatics tools and immunohistochemical staining were used to evaluate LASS2 expression, and the results were analysed in relation to overall survival and clinical association in multiple cancers. Coimmunoprecipitation-coupled liquid chromatography-mass spectrometry (co-IP LC-MS) was performed to identify potential LASS2-interacting proteins in thyroid, breast, and liver cancer cell lines. Transcriptomics, proteomics and metabolomics analyses of multiple cancer cell types were performed using MS or LC-MS to further explore the underlying mechanisms involved. Among these tumour cells, the common LASS2 interaction partner transferrin receptor (TFRC) was analysed by protein-protein docking and validated by coimmunoprecipitation western blot, immunofluorescence, and proximity ligation assays. Then, we performed experiments in which tumour cells were treated with Fer-1 or erastin or left untreated, with or without inducing LASS2 overexpression, and assessed the molecular biological and cellular functions by corresponding analyses.

RESULTS

Low LASS2 expression is correlated with adverse clinical characteristic and poor prognosis in patients with thyroid cancer, breast cancer or HCC. Multiomics analyses revealed significant changes in the ferroptosis signalling pathway, iron ion transport and iron homeostasis. Our in vitro experiments revealed that LASS2 overexpression regulated ferroptosis status in these tumour cells by affecting iron homeostasis, which in turn inhibited tumour migration, invasion and EMT. In addition, LASS2 overexpression reversed the changes in tumour cell metastasis induced by either Fer-1 or erastin. Mechanistically, LASS2 interacts directly with TFRC to regulate iron homeostasis in these tumour cells.

CONCLUSIONS

In summary, our study reveals for the first time that LASS2 can inhibit tumour cell metastasis by interacting with TFRC to regulate iron metabolism and influence ferroptosis status in thyroid, breast, and liver cancer cells, these results suggest potential universal therapeutic targets for the treatment of these cancers.

Good or bad: Paradox of plasminogen activator inhibitor 1 (PAI-1) in digestive system tumors

The fibrinolytic system is involved in many physiological functions, among which the important members can interact with each other, either synergistically or antagonistically to participate in the pathogenesis of many diseases. Plasminogen activator inhibitor 1 (PAI-1) acts as a crucial element of the fibrinolytic system and functions in an anti-fibrinolytic manner in the normal coagulation process. It inhibits plasminogen activator, and affects the relationship between cells and extracellular matrix. PAI-1 not only involved in blood diseases, inflammation, obesity and metabolic syndrome but also in tumor pathology. Especially PAI-1 plays a different role in different digestive tumors as an oncogene or cancer suppressor, even a dual role for the same cancer. We term this phenomenon "PAI-1 paradox". PAI-1 is acknowledged to have both uPA-dependent and -independent effects, and its different actions can result in both beneficial and adverse consequences. Therefore, this review will elaborate on PAI-1 structure, the dual value of PAI-1 in different digestive system tumors, gene polymorphisms, the uPA-dependent and -independent mechanisms of regulatory networks, and the drugs targeted by PAI-1 to deepen the comprehensive understanding of PAI-1 in digestive system tumors.

LASS2 overexpression enhances early apoptosis of lung cancer cells through the caspase‑dependent pathway

In a previous study by the authors, the longevity assurance homolog 2 (LASS2) gene was determined to inhibit activity of vacuolar H+‑ATPase (V‑ATPase) by combining with the C subunit (ATP6L) of V‑ATPase. However, the influence of LASS2 overexpression and silencing on apoptosis of human lung cancer cells 95D or 95C remains unclear. Thus, the effect of LASS2 on apoptosis and its potential mechanisms were investigated in 95D and 95C cells. Using the lentiviral transfection method, lentiviral vectors of LASS2 overexpression and silencing were transfected into 95D and 95C cells, respectively. The apoptotic ability of tumor cells was observed by flow cytometry. The expression levels of LASS2, Bcl‑2, Bax, cytochrome c, caspase‑9, and caspase‑3 were detected by western blotting. CCK‑8 assay was used to detect the growth ability of tumor cells in vitro. Flow cytometric analysis revealed that LASS2 overexpression could promote the early apoptosis of lung cancer cells 95D. CCK‑8 assay demonstrated that LASS2 overexpression inhibited the proliferation of 95D cells. Additionally, LASS2 overexpression decreased the expression of Bcl‑2, induced the release of cytochrome c from mitochondria, and promoted the activation of caspase‑9 and caspase‑3. There was a significant difference in the expression of Bcl‑2, cytochrome c, caspase‑9 and caspase‑3 in the LASS2‑overexpression group compared with the normal and negative control groups. Alternatively, the aforementioned experiments in lung cancer cells 95C following LASS2 silencing produced the opposite effects. LASS2 may induce early apoptosis of lung cancer cells by influencing the caspase‑dependent mitochondrial pathway.

Targeting sphingosine kinase 1 (SK1) enhances oncogene-induced senescence through ceramide synthase 2 (CerS2)-mediated generation of very-long-chain ceramides

Senescence is an antiproliferative mechanism that can suppress tumor development and can be induced by oncogenes such as genes of the Ras family. Although studies have implicated bioactive sphingolipids (SL) in senescence, the specific mechanisms remain unclear. Here, using MCF10A mammary epithelial cells, we demonstrate that oncogenic K-Ras (Kirsten rat sarcoma viral oncogene homolog) is sufficient to induce cell transformation as well as cell senescence-as revealed by increases in the percentage of cells in the G1 phase of the cell cycle, p21WAF1/Cip1/CDKN1A (p21) expression, and senescence-associated β-galactosidase activity (SA-β-gal). Furthermore, oncogenic K-Ras altered SL metabolism, with an increase of long-chain (LC) C18, C20 ceramides (Cer), and very-long-chain (VLC) C22:1, C24 Cer, and an increase of sphingosine kinase 1 (SK1) expression. Since Cer and sphingosine-1-phosphate have been shown to exert opposite effects on cellular senescence, we hypothesized that targeting SK1 could enhance oncogenic K-Ras-induced senescence. Indeed, SK1 downregulation or inhibition enhanced p21 expression and SA-β-gal in cells expressing oncogenic K-Ras and impeded cell growth. Moreover, SK1 knockdown further increased LC and VLC Cer species (C18, C20, C22:1, C24, C24:1, C26:1), especially the ones increased by oncogenic K-Ras. Fumonisin B1 (FB1), an inhibitor of ceramide synthases (CerS), reduced p21 expression induced by oncogenic K-Ras both with and without SK1 knockdown. Functionally, FB1 reversed the growth defect induced by oncogenic K-Ras, confirming the importance of Cer generation in the senescent phenotype. More specifically, downregulation of CerS2 by siRNA blocked the increase of VLC Cer (C24, C24:1, and C26:1) induced by SK1 knockdown and phenocopied the effects of FB1 on p21 expression. Taken together, these data show that targeting SK1 is a potential therapeutic strategy in cancer, enhancing oncogene-induced senescence through an increase of VLC Cer downstream of CerS2.

Association of rs8444 polymorphism in the LASS2 3'-UTR and bladder cancer risk in Chinese population

The aim of the present study was to explore the correlations between single nucleotide polymorphisms in LASS2 gene 3'-untranslated regions and bladder cancer risk in Chinese population. We first performed PCR and sequence for LASS2-3'-UTR in 105 bladder cancer patients and 100 control subjects. Next, multivariate logistic regression analysis was used to determine the relationship between single nucleotide polymorphisms frequency and susceptibility of bladder cancer, and clinical features in 105 cases. In addition, survival curves and Cox Regression analysis were used to investigate the effect of single nucleotide polymorphisms on clinical outcome in 58 cases. Finally, quantitative reverse-transcription PCR and immunohistochemical were performed to explore the influence of single nucleotide polymorphisms on LASS2 expression. We found that a single nucleotide polymorphism (rs8444 C>T) located in the 3'-UTR of LASS2 was significantly associated with the risk of bladder cancer. We also showed the frequency of rs8444 T genotype was higher in bladder cancer group and correlated with the risk of clinical prognosis. Yet, there were no significant correlations between T/C allele frequencies and the distributions of rs8444 genotype and tumor-node-metastasis stage, histological grade and distant metastasis in bladder cancer. Furthermore, we demonstrated that rs8444 C>T could affect LASS2 expression by single nucleotide polymorphism-related mRNA stability. Our results showed that LASS2-3'-UTR rs8444 C>T polymorphism was significantly associated with the individual risk and the poor overall survival of bladder cancer, suggesting that rs8444 TT genotype maybe act as an independent risk factor of susceptibility and clinical prognosis for bladder cancer in Chinese population.

Derepression of co-silenced tumor suppressor genes by nanoparticle-loaded circular ssDNA reduces tumor malignancy

The co-silencing of multiple tumor suppressor genes can lead to escalated malignancy in cancer cells. Given the limited efficacy of anticancer therapies targeting single tumor suppressor genes, we developed small circular single-stranded DNA (CSSD) that can up-regulate the expression of co-silenced tumor suppressor genes by sequestering microRNAs (miRNAs) that negatively regulate these genes. We found that cancer patients with low tumor expression of the tumor suppressor genes KLF17, CDH1, and LASS2 had shortened survival times. The up-regulation of these genes upon transfection of artificial CSSD-9 inhibited tumor proliferation and metastasis and promoted apoptosis in vitro as well as in ex vivo and patient-derived xenograft models. In addition, CSSD is more stable and effective than current miRNA inhibitors, and transfecting CSSDs via nanoparticles substantially improved delivery efficiency. The use of a single CSSD can promote the inhibition of multiple tumor suppressor genes. This study provides evidence for the possibility of using CSSDs as therapeutic miRNA inhibitors to target the co-silencing of multiple tumor suppressor genes.

miR-3622a promotes proliferation and invasion of bladder cancer cells by downregulating LASS2

As a tumor metastasis suppressor gene, LASS2 has been found to be negatively associated with the stage of bladder cancer and overall survival of patients. However, the mechanisms regulating LASS2 in bladder cancer remain poorly understood. Here, we aim to identify a miRNA that targets LASS2 from bladder cancer-associated miRNAs and to reveal its potential functions in bladder cancer cells. Through miRNA microarray and bioinformatics analyses, we identified miR-3622a as a negative regulator of LASS2. The expression levels of miR-3622a in bladder cancer tissues were negatively correlated with the overall survival of patients. Overexpression of miR-3622a significantly increased the proliferation and invasion abilities of bladder cancer cells. In conclusion, our results indicate that miR-3622a promotes the proliferation and invasion of bladder cancer cells by downregulating LASS2.

Clinical and pathological significance of Homo sapiens ceramide synthase 2 (CerS-2) in diverse human cancers

Homo sapiens ceramide synthase 2 (CerS-2) plays an important role in inhibiting invasion and metastasis of tumor cells and has been reported as a tumor metastasis suppressor gene in diverse cancers. Thus, low level of CerS-2 protein might suggest a bad prognosis and up-regulation of CerS-2 protein might act as a promising therapeutic strategy for malignant tumors. In this review, we discussed the expression, as well as the clinical and pathological significance of CerS-2 in diverse human cancers. The pathological processes and molecular pathways regulated by CerS-2 were also summarized.

Roles of Ceramides and Other Sphingolipids in Immune Cell Function and Inflammation

Ceramides are bioactive sphingolipids that support the structure of the plasma membrane and mediate numerous cell-signaling events in eukaryotic cells. The finding that ceramides act as second messengers transducing cellular signals has attracted substantial attention in several fields of Biology. Since all cells contain lipid plasma membranes, the impact of various ceramides, ceramide synthases, ceramide metabolites, and other sphingolipids has been implicated in a vast range of cellular functions including, migration, proliferation, response to external stimuli, and death. The roles of lipids in these functions widely differ among the diverse cell types. Herein, we discuss the roles of ceramides and other sphingolipids in mediating the function of various immune cells; particularly dendritic cells, neutrophils, and macrophages. In addition, we highlight the main studies describing effects of ceramides in inflammation, specifically in various inflammatory settings including insulin resistance, graft-versus-host disease, immune suppression in cancer, multiple sclerosis, and inflammatory bowel disease.

MicroRNA-98 promotes drug resistance and regulates mitochondrial dynamics by targeting LASS2 in bladder cancer cells

MicroRNA-98(miR-98) has been shown to be critical for tumorigenesis, however its involvement in bladder cancer are unclear. The present study aims to investigate the expression, biological roles and potential mechanisms of miR-98 in human bladder cancer. We found that miR-98 was upregulated in bladder urothelial carcinoma tissues compared with adjacent normal tissues. In addition, miR-98 expression was higher in bladder cancer cell lines than in uroepithelial cell line SV-HUC-1. Functional studies revealed that miR-98 mimic promoted proliferation of T24 cells while miR-98 inhibitor inhibited proliferation of BIU-87 cells. Moreover, miR-98 mimic increased cisplatin/doxorubicin resistance and inhibited apoptosis in T24 cells, while miR-98 inhibitor decreased chemoresistance and facilitated apoptosis in BIU-87 cells. Further experiments using MitoTracker and JC-1 staining showed that miR-98 could regulate mitochondrial fission/fusion balance and mitochondrial membrane potential. Western blot showed that miR-98 upregulated cyclin D1, p-Drp1 and Drp1. Using luciferase reporter assay, we demonstrated that LASS2 acted as a direct target of miR-98. LASS2 overexpression induced mitochondrial fusion and downregulated mitochondrial potential, with decreased p-Drp1 status. Additionally, LASS2 siRNA abrogated the effects of miR-98 mimic on Drp1phosphorylation and chemoresistance. We also found a negative correlation between LASS2 and miR-98 in bladder cancer tissues. In conclusion, our study demonstrates that miR-98 targets LASS2 and regulates bladder cancer chemoresistance through modulation of mitochondrial function.

Hepatocyte-specific deletion of LASS2 protects against diet-induced hepatic steatosis and insulin resistance

Homo sapienslongevity assurance homolog 2 of yeast LAG1 (LASS2) is expressed mostly in human liver. Here, we explored roles of LASS2 in pathogenesis of hepatic steatosis. Hepatocyte-specific LASS2 knockout (LASS2^-/-) mice were generated using Cre-LoxP system. LASS2^-/- and wild-type (WT) mice were fed with chow or high-fat diet (HFD). We found LASS2^-/- mice were resistant to HFD-induced hepatic steatosis and insulin resistance. In HFD-fed mice, LASS2 deficiency significantly inhibited p38 MAPK and ERK1/ERK2 signaling in mouse liver. This effect was mediated by a significant increase of V-ATPase activity and a decrease of ROS level. We also observed that elevated expression of LASS2 in mouse hepatocyte cell line AML12 obviously decreased V-ATPase activity and increased ROS level by activation of p38 MAPK and ERK1/ERK2 signaling. Our findings indicate that LASS2 plays an important role in the pathogenesis of diet-induced hepatic steatosis and is a potential novel target for prevention and intervention of liver diseases.

LASS2 regulates invasion and chemoresistance via ERK/Drp1 modulated mitochondrial dynamics in bladder cancer cells

Mitochondria coordinated a lot of vital cellular processes of energy production and distribution. Change of mitochondrial functions has been implicated in cancer progression. The present study aims to investigate the involvement of mitochondria dynamics in LASS2 induced invasion and chemoresistance of bladder cancer cells. J82 and BIU87 cell lines were used for LASS2 plasmid transfection while siRNA knockdown was carried out in 5637 cell line. Matrigel invasion assay and Annexin V/PI staining demonstrated that LASS2 negatively regulated cancer cell invasion and chemoresistance. JC-1 staining suggested that LASS2 overexpression downregulated mitochondrial membrane potential. Mitotracker staining showed that LASS2 induced mitochondrial fusion and inhibited mitochondrial fission. In addition, LASS2 overexpression downregulated expression of mitochondrial fission protein p-Drp1 Drp1 and Fis1. While depletion of LASS2 exhibited the opposite effects. Drp1 inhibitor Mdivi abolished invasion and chemoresistance induced by LASS2 siRNA. Furthermore, we found that LASS2 overexpression could inhibit phosphorylation of ERK, which act upstream of Drp1. ERK inhibitor PD98059 suppressed Drp1 phosphorylation and abrogated the effects of LASS2 depletion. In conclusion, the present study demonstrated that LASS2 inhibits bladder cancer invasion and chemoresistance through regulation of ERK-Drp1 induced mitochondrial dynamics.

TGF-β1 mediates the effects of aspirin on colonic tumor cell proliferation and apoptosis

Previous studies have demonstrated that aspirin serves an important role in chemoprevention and the suppression of colorectal cancer (CRC); however, the underlying mechanisms for this inhibition by aspirin remain unclear. Aspirin is capable of promoting apoptosis through prostaglandin-dependent orprostaglandin-independent signaling pathways. In the prostaglandin-dependent pathways, inhibition of cyclooxygenase (COX), particularly COX-2, is the primary mechanism known to be involved in aspirin-induced CRC suppression. Previous studies have implicated prostaglandin-independent signaling pathways and certain associated proteins, including SOX7, in aspirin-induced CRC suppression. In the present study, a newly-characterized association between aspirin, transforming growth factor (TGF)-β1 and CRC inhibition was identified. Specifically, aspirin triggers CRC cell apoptosis by inducing the secretion of TGF-β1, and the increased TGF-β1 then leads to apoptosis and proliferation inhibition in CRC cells.

Liver-specific deletion of LASS2 delayed regeneration of mouse liver after partial hepatectomy

The capacity of liver regeneration is critical for patients with liver diseases. However, cellular and molecular mechanisms of liver regeneration are still incompletely defined. Here, we assessed roles of LASS2 in liver regeneration following partial hepatectomy (PHx) in mice. Our results showed that protein level of LASS2 remarkably increased during liver regeneration after PHx in wildtype (WT) mice. Comparing to WT mice, liver regeneration index after PHx was significantly decreased from day 1 to day 5 in liver-specific LASS2 knockout (LASS2-LKO) mice. Interestingly, liver mass of LASS2-LKO mice could sufficiently recover at day 14 after PHx. Immunohistochemistry (IHC) and western blot analyses revealed that proliferation markers, such as PCNA and Ki67, were potently reduced during liver regeneration in LASS2-LKO mice. In addition, several cell cycle related molecules, such as cyclin A, CDK2 and p-Rb, were decreased in LASS2-LKO mice after PHx. Co-immunoprecipitation assay further revealed a decreased formation of CDK4/cyclin D1 complex after PHx in LASS2-LKO mice. However, phosphorylation of Akt was significantly activated from day 2 after PHx in LASS2-LKO mice when compared with that in WT mice, which may explain the recovery of liver mass at the late stage of liver regeneration in LASS2-LKO mice. Taken together, we conclude that LASS2 plays an important role in efficient liver regeneration in response to PHx.

The role of LASS2 in regulating bladder cancer cell tumorigenicity in a nude mouse model

Previous in vitro studies have demonstrated that LAG1 longevity assurance homolog 2 (LASS2) is a novel tumor suppressor gene that is significantly associated with the proliferation and invasion ability of tumor cells. However, the role LASS2 serves in regulating bladder cancer cell tumorigenicity and tumor growth in vivo has not yet been elucidated in animal or clinical studies. In the present study, LASS2 knockdown in human bladder cancer EJ-M3 cells significantly promoted the growth of xenografts in nude mice compared with the control group, while overexpression of LASS2 suppressed tumor growth; however, this was not statistically significant. Furthermore, LASS2 knockdown resulted in more apparent heteromorphism and a higher activity of matrix metalloproteinase (MMP)-2 and MMP-9 in xenograft tumors. The data from the present study demonstrated that LASS2 knockdown significantly promoted the tumorigenicity and growth of EJ-M3 xenograft tumors in nude mice, and that LASS2 overexpression has a tendency to inhibit the growth of xenografts, suggesting that it may be a potential therapeutic target for bladder cancer.

Co-expression of LASS2 and TGF-β1 predicts poor prognosis in hepatocellular carcinoma

Longevity assurance homolog 2 of yeast LAG1 (LASS2) has been reported to act as an important tumor suppressor in the development of human cancers. However, little is known about the prognostic value of LASS2 in hepatocellular carcinoma (HCC) . In the present study, we analyzed correlation between LASS2 and TGF-β1 levels, and evaluated their prognostic values in HCC patients. We first analyzed the expression of LASS2 and TGF-β1 in two independent cohorts (test cohort: 184 HCC patients; validation cohort: 118 HCC patients) using immunohistochemistry (IHC). Kaplan-Meier survival and Cox regression analyses were executed to evaluate the prognosis of HCC. The results of IHC analysis revealed a positive correlation between the expression of LASS2 and TGF-β1. HCC Patients with low expression of LASS2 and TGF-β1 had shorter overall survival (OS) and time to recurrence (TTR) than patients with high expression of LASS2 and TGF-β1. Furthermore, combination of LASS2 and TGF-β1 was an independent and significant risk factor for OS and TTR. In conclusion, low expression of LASS2 and TGF-β1 contributes to the aggressiveness and poor prognosis of HCC, and may represent a novel prognostic biomarker for HCC patients.

The asialoglycoprotein receptor suppresses the metastasis of hepatocellular carcinoma via LASS2-mediated inhibition of V-ATPase activity

The asialoglycoprotein receptor (ASGR), which is expressed mainly in hepatocytes, is downregulated in poorly differentiated hepatocellular carcinoma (HCC). Here we investigated the role of ASGR1 in HCC metastasis as well as the possible underlying molecular mechanisms. We found that ASGR1 was downregulated in HCC tissue compared with adjacent non-tumorous liver tissue and that lower ASGR1 expression was associated with higher TNM stage and poorer prognosis in HCC patients. ASGR1 overexpression inhibited hepatoma cell migration and invasion in vitro and in vivo, while ASGR1 knockdown had the opposite effects. Furthermore, ASGR1 interacted directly with human longevity assurance homolog 2 of yeast LAG1 (LASS2). Knockdown of LASS2 attenuated the inhibitory effects of ASGR1 on hepatoma cell migration and invasion in vitro. ASGR1 decreased V-ATPase activity in hepatoma cells, and this was reversed by LASS2 knockdown. Finally, HCC patients with low LASS2 levels had poor prognosis, while those with high ASGR1 and LASS2 levels had better prognosis. Thus, ASGR1 may act as a potential metastasis suppressor in HCC, and the combination of ASGR1 and LASS2 may help predict the prognosis of HCC patients.

miR-9 promotes cell proliferation and inhibits apoptosis by targeting LASS2 in bladder cancer

MicroRNA-9 upregulation was reported in several tumors. However, its function and mechanism in human bladder cancer remains obscure. The present study aims to identify the expression pattern, biological roles and potential mechanism of miR-9 in human bladder cancers. We found that expression level of miR-9 in bladder cancer tissues was higher than normal tissues. miR-9 mimic transfection was performed in T24 and 5637 cells with low miR-9 expression, and miR-9 inhibitor was employed in BIU-87 cell line with high endogenous expression. miR-9 increased cell proliferation, cell cycle progression, invasion and chemoresistance, with upregulation of cyclin D1, MMP9, Bcl-2, and survivin and downregulation of E-cadherin. Using luciferase reporter assay, we confirmed that LASS2 was a direct target of miR-9 in bladder cancer cells. Transfection of miR-9 mimic downregulated LASS2 expression. LASS2 transfection downregulated Bcl-2 and survivin expression, which were induced by miR-9 mimic in both cell lines. In conclusion, these results indicate that miR-9 upregulation might be associated with malignant phenotype of bladder cancer. miR-9 promotes chemoresistance of bladder cancer cells by target LASS2.

The important role of ADAM8 in the progression of hepatocellular carcinoma induced by diethylnitrosamine in mice

This study focuses on investigating the concrete role of a disintegrin and metalloproteinase 8 (ADAM8) in the progression of hepatocellular carcinoma (HCC). Mice received anti-ADAM8 monoclonal antibody (mAb) of 100 μg/100 μl, 200 μg/100 μl or 300 μg/100 μl, respectively, in phosphate-buffered saline (PBS) or PBS intervention during the progression of HCC induced by diethylnitrosamine. The survival rate, body weight, and relative liver weight were determined in the mice. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and α-fetoprotein (AFP) level, hematoxylin–eosin staining, the expression level of vascular endothelial growth factor A (VEGF-A), proliferating cell nuclear antigen (PCNA), caspase 3 (Casp3), B cell leukemia 2 (Bcl2), B cell leukemia 2-associated X protein (Bax), protein p53 (P53), and ADAM8 were detected in the mice at the end of the 24th week. Our results showed that anti-ADAM8 mAb intervention effectively improved the survival rate, reduced the body weight loss and increased the relative liver weight in mice in a dose-dependent manner ( p < 0.05 or p < 0.01). Anti-ADAM8 mAb intervention also significantly lowered serum AST, ALT, and AFP levels ( p < 0.05 or p < 0.01), slowed the progression of HCC ( p < 0.05 or p < 0.01), induced the expression of Casp3, Bax, and P53 ( p < 0.05 or p < 0.01), and inhibited the expression of VEGF-A, PCNA, and Bcl2 in the liver of mice ( p < 0.05 or p < 0.01) in a dose-dependent manner compared with the mice receiving PBS intervention. Our study suggested that ADAM8 might promote the progression of HCC by regulating the expression of these factors. Anti-ADAM8 mAb intervention might be suitable as a potential method for HCC therapy.

Tumor metastasis suppressor gene-1 and tumors

Tumor metastasis suppressor gene-1 (TMSG-1) is a newly discovered tumor metastasis suppressor gene that plays important roles in promoting apoptosis and inhibiting invasion and metastasis of tumor cells. The inhibitory function of TMSG-1 in tumor cells may be related to vacuolar H⁺-ATPase and ceramide, but the underlying mechanism remains unknown. This review discusses the discovery of TMSG-1, the structure of TMSG-1 protein, as well as its possible mechanisms of action, expression in tumors and applications.