BACKGROUND:Metabolic dysfunction-associated steatohepatitis (MASH) is anticipated to become the leading cause of hepatocellular carcinoma (HCC). Accumulating evidence indicates that N6-methyladenosine (m6A)-modified circular RNAs (circRNAs) play key roles in tumor malignant progression. However, the precise molecular mechanisms by which circRNAs and their m6A modification regulatory networks respond to metabolic reprogramming, such as lipid overload stress, to drive malignant tumor progression in the context of MASH-related HCC remain unclear. This study aimed to investigate the role and regulatory network of m6A-modified circRNAs in MASH-related HCC. METHODS:Epitranscriptomic microarray and in situ hybridization assays were used to validate circTACC3 expression in MASH-related HCC specimens. Palmitic acid (PA) and oleic acid (OA) was applied to NAC-organ assembled three-dimensional-organoid and HCC cell lines to imitate pathological lipid overload. The circTACC3-paraspeckle interaction was studied utilizing fluorescence lifetime imaging microscopy-Forster resonance energy transfer. An integrative analysis combining DNA-RNA immunoprecipitation combined with chromatin isolation by RNA purification (DRIP-ChIRP), γH2AX cleavage under target and tagmentation, and high-throughput/resolution chromosome conformation capture sequencing were used to study chromatin remodeling induced by circTACC3-formed RNA-DNA hybrids (R loops) at DNA double-strand break (DSB) loci during lipid overload. RESULTS:The most prevalent m6A-modified circRNA in MASH-related HCC, circTACC3, had a substantial impact on the intracellular lipid accumulation, growth, and environmental adaptive survival of tumor cells. Under lipid overload conditions, circTACC3 interacted directly with non-POU domain-containing octamer-binding protein (NONO/p54nrb) to assemble intranuclear paraspeckle. This process was dependent on the m6A-modification sites of circTACC3 and facilitated its nuclear retention. Using DRIP-ChIRP-sequencing, we demonstrated that circTACC3-containing paraspeckles were recruited to DSB foci to form R loops (DSB-circTACC3-R loops). We discovered 4 highly enriched motifs of DSB-circTACC3-R loops. DSB-circTACC3-R loops further facilitated the contact and fusion of topologically associated domains (TADs) and selectively activated genes related to the malignant phenotype of MASH-related HCC. Interestingly, circTACC3-R loops exerted positive feedback control over the assembly of circTACC3 paraspeckle and clustering of TADs. CONCLUSIONS:The m6A modification-dependent circTACC3-paraspeckle assembly results in the formation of R loops at DSB foci, leading to chromatin remodeling and the activation of genes involved in MASH-related HCC malignant progression. This process identifies potential therapeutic targets.
Despite the revolutionary progress in cancer immunotherapy, only a minority of hepatocellular carcinoma (HCC) patients respond to immune checkpoint inhibitors (ICIs). In this study, we found that the oncogenic circular RNA Circ-CDYL in HCC influences the efficacy of immunotherapy and the stemness characteristics of HCC cells by interacting with the hornerin (HRNR) protein. The degraded anti-PD-L1 immunotherapy responses induced by Circ-CDYL and HRNR were confirmed by peripheral blood mononuclear cells (PBMCs) killing assays in HCC cells, patient-derived organoids, and humanized immune system mouse models. Furthermore, Circ-CDYL interference reversed the cytotoxicity and proliferation of CD8+ T cells, resulting in ameliorated immune evasion in tumor spheroids upon anti-PD-L1 treatment. Mechanistically, Circ-CDYL upregulated HRNR expression by stabilizing the HRNR protein through the prevention of its degradation by the E3 ubiquitin ligase synoviolin 1 (SYVN1), which in sequence promoted the phosphorylation of the mTORC1 and p70S6K substrate. The abnormally activated mTORC1-p70S6K signaling increases the stemness of HCC cells and upregulates PD-L1 expression, which may attenuate anti-PD-L1 therapy efficacy via PD-L1+ exosomes. Our study revealed the mechanism by which Circ-CDYL and HRNR regulate the sensitivity of HCC to anti-PD-L1 therapy, and the findings have potential implications for patient stratification and clinical decision-making in HCC immunotherapy.
CircRNAs play multiple roles in a variety of cellular processes. We found that Circ-CDYL is highly enriched in early HCC plasma exosomes. Moreover, EpCAM+ HCC cells and exosomes had significant Circ-CDYL levels. We postulated that Circ-CDYL-enriched and EpCAM-positive exosomes would function as liver tumor-initiating exosomes (LTi-Exos). As predicted, intercellular transfer of LTi-Exos activates the HDGF-PI3K-AKT-mTOR and HIF1AN-NOTCH2 axes in recipient cells, promoting malignancy. Upstream, we found that the N6-methyladenosine (m6A) modification of Circ-CDYL exerted its action in HCC cells through a dual mechanism. First, it stimulated back-splicing processes via YTHDC1 to promote Circ-CDYL biogenesis. Second, it facilitates the active sorting of Circ-CDYL into exosomes via hnRNPA2/B1. Clinically, the combination of LTi-Exos and plasma alpha-fetoprotein (AFP) provides a promising early diagnostic biomarker for HCC with an AUC of 0.896. This study highlights the effect and mechanism by which m6A modification promotes hepatocarcinogenesis via modulation of the tumor microenvironment by LTi-Exos.
BACKGROUND & AIMS:Dysregulation of microRNA (miRNA) expression in various cancers and their vital roles in malignant progression of cancers are well investigated. Our previous studies have analysed miRNAs that promote malignant progression in hepatocellular carcinoma (HCC); this study aims to systematically elucidate the mechanism of metastasis suppressor miRNAs in HCC.METHODS:High-throughput RNA sequencing was used to identify anti-metastatic miRNAs. The relative expression levels of miRNAs were confirmed by qRT-PCR. The biological functions of miRNAs were detected in vitro and in vivo. Circulating tumour cells (CTCs) were enriched from blood samples of HCC patients and cultured by three-dimensional (3D) system. Kaplan-Meier and Cox regression were used to analyse the value of potential target mRNAs on overall survival.RESULTS:miR-2392 was significantly down-regulated in HCC. Overexpression of miR-2392 suppressed proliferation, clonogenicity, mobility, spheroid formation and maintenance of cancer stem cells (CSC)-like characteristics in HCC cells. CTCs from HCC patients with lower serum miR-2392 level had stronger cell spheroid formation ability. A negative correlation between the content of miR-2392 in serum and the number of CTC spheroids had been found. We identified Jagged2 (JAG2) as a direct target of miR-2392. miR-2392 inhibited the expression of JAG2 by targeting 3'-UTR of JAG2. Down-regulation of JAG2 inhibited the overexpression effects of miR-2392 in vitro and in vivo. JAG2 is highly expressed in HCC and is closely related to poor prognosis and survival of patients.CONCLUSIONS:miR-2392 may play a role as a tumour suppressor to guide the individualized precise treatment of HCC.
Background: Reversible phosphorylation and dephosphorylation play important roles in cell function and cell signal transduction. PPP2R5A is responsible for specifically regulating the catalytic function, substrate specificity and intracellular localization of the tumor suppressor phosphatase PP2A. Therefore, the abnormal expression and function of PPP2R5A may be related to the occurrence and development of tumors.Results: This study showed that PPP2R5A inhibited the proliferation and metastasis of hepatocellular carcinoma (HCC) cells, and acted as a tumor suppressor in HCC cells, but it had no significant effect on cell cycle. Further research found that PPP2R5A exerted tumor suppressor efficacy by inhibiting the MAPK/AKT/WNT signaling pathway. Combined with analysis of clinical tissue samples and TCGA database, it was found that the expression of PPP2R5A in tumor tissues of Chinese HCC patients was down-regulated and significantly correlated with the progression-free survival (PFS) of HCC patients. On the contrary, PPP2R5A showed an up-regulation trend in HCC cases in TCGA database although its effect on PFS was the same with that in Chinese HCC patients. HBV infection is the main pathogenic factor of HCC in China. It was found that hepatitis B virus (HBV) infection reduced the content of PPP2R5A in cells.Conclusions: It was concluded that HBV inhibited the initiation of the protective mechanism mediated by PPP2R5A, making the occurrence and progress of HCC more "unimpeded". This conclusion will further reveal the role of PPP2R5A in HBV-induced and HBV-unrelated HCC, therefore, providing clues for the prevention and treatment of the two types of HCC, respectively.
BACKGROUND AND AIM:The proline rich mitotic checkpoint control factor (PRCC) is involved in the splicing process of pre-mRNA. This study aims to elucidate PRCC molecular function, regulatory mechanism and diagnostic value in hepatocellular carcinoma (HCC).METHODS:The tissue microarray and serum samples from HCC patients were used to investigate the clinical value of PRCC. The biological function and molecular mechanism of PRCC were demonstrated by cell biology, biochemical and animal experiments. The relationship between PRCC and intratumoral heterogeneity (ITH) was analyzed by bioinformatics.RESULTS:PRCC was highly expressed in HCC tissues and related to the poor prognosis of HCC patients, its contents were elevated in the preoperative sera of HCC patients. PRCC exhibited high application potential as a substitute or adjuvant of alpha-fetoprotein (AFP) for clinical diagnosis of HCC. It had no significant effect on the proliferation of cancer cells, but could inhibit spheroid formation and metastasis of HCC cells in vitro and in vivo. The high ectopic expression of PRCC made cancer cells insensitive to DNA damage, and enhanced the heterogeneity of HCC cells by inhibiting the JNK/ATM/ATR/ATF2 axis. The HCC patients with high PRCC expression had high ITH, which corresponded to a short overall survival in patients.CONCLUSIONS:PRCC has high application potential as a substitute or adjuvant of AFP for clinical diagnosis of HCC. The high ectopic expression of PRCC not only caused HCC cells to resist to cell death induced by DNA damage, but also endowed cancer cells with numerous DNA mutations to become increasingly heterogeneous, finally leading to a poor prognosis in HCC patients. These data suggested PRCC could be a promising therapeutic target in HCC patients.
Cancer stem cells are considered to be tumor-initiating cells. To explain the initiation or progression of hepatocellular carcinoma (HCC), we previously established a culture system that may enrich hepatic cancer stem-like cells (HCSCs). However, the regulatory mechanisms by which HCSCs acquire stem cell properties remain unclear. In the present study, three pairs of HCSCs and case-matched human HCC cells were analyzed by high-throughput screening, and novel biomarkers and pathways for the regulation of HCSCs were identified. The results led to the identification and stratification of 406 differentially expressed genes (DEGs), among which 73 GO terms were found to be significantly associated with DEGs in HCSCs, and only complement and coagulation cascade pathways were identified during the development of HCSCs. By combining the results of the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, it was revealed that 7 genes were downregulated in the complement and coagulation cascade pathways, and 7 miRNAs were predicted to target several downregulated genes involved in these pathways. The results may contribute toward hepatic cancer stem cell studies and novel drug research for HCC treatment.
Objective: To explore a method for culturing hepatocellular carcinoma and tumor-infiltrating lymphocytes (HCC-TIL) and investigate the mechanism of TIL in killing tumors. Methods: The distribution of regulatory T cells (Treg) in HCC was detected by immunohistochemistry. Conventional TIL and oligoclonal TIL were isolated by the traditional method of enzyme digestion combined with mechanical treatment for whole HCC and micro HCC tissue block culturing method. MTT was used to compare the killing activity of TIL. Flow cytometry was used to analyze the proportion of CD8+ T cells and Treg cells in TIL. Tumor-bearing mice were established, and TIL adoptive immunotherapy was performed. Results: Treg cells were mainly distributed in the stroma of HCC. In vitro experiments showed oligoclonal TIL had higher cytotoxicity to tumor cells which negatively correlated with the proportion of Treg cells. In vivo experiments showed oligoclonal TIL had a higher anti-tumor effect. IFN-γ in peripheral blood and the positive rate of intratumoral lymphocytic infiltration in oligoclonal TIL group were both higher. TGF-β and IL-10 in peripheral blood and the positive rate of intratumoral FoxP3 and IL-17 were both lower than those in conventional TIL group. Conclusion: The oligoclonal TIL culture method could obtain TIL with higher purity, and cytotoxicity to tumor cells was associated with Treg cells. The oligoclonal TIL had cytotoxicity to autologous HCC cells and significant inhibitory effect on the growth of transplanted tumors. The mechanism might be associated with the inhibition of Treg cells proliferation, increase of IFN-γ secretion, and decrease of TGF-β, IL-10, and IL-17 secretion.
Hepatocellular carcinoma (HCC) is the second leading cause of cancer related death which needs novel drugs to improve patient outcome. Survivin overexpresses in HCC and contributes to HCC malignant progression. In this study, we established a Survivin-targeted drug screening platform, a cell model HepG2-Sur5P-EGFP-Sur3U stably transfected with lentivirus carrying an EGFP expression cassette, in which the EGFP expression was regulated by the upstream Survivin promoter and downstream Survivin 3′-UTR. By using this platform, we screened and easily identified one of matrine derivatives, WM-127, from hundreds of matrine derivatives. WM-127 was demonstrated to be a strong Survivin inhibitor that inhibited cell proliferation, induced cell cycle arrest and apoptosis of HCC cells, and suppressed the growth of HCC xenografted tumors in nude mice, suggesting that WM-127 might be a promising drug for HCC treatment. WM-127 exhibited less cytotoxicity in normal cells. Mechanistic studies showed that WM-127 suppressed the activity of Survivin/β-catenin pathway and the expression of Bax to induce cell cycle arrest and apoptosis. Taken together, we constructed an economical, practical, efficient and convenient cell platform for screening the Survivin-targeted drugs from the enormous diversity of chemicals or factors, which would be a potential tool for antitumor drug research and development.
Midkine is overexpressed in hepatocellular carcinoma (HCC) and plays a role in tumor progression, but less is known about its role in resistance of circulating tumor cells (CTCs) to anoikis which leading to recurrence and metastasis. The aim of the present study was to analyze whether midkine was associated with HCC progression with anoikis resistance. We found that cultured HCC cells were more resistant to anoikis, which paralleled midkine expression, and midkine treatment significantly inhibited anoikis in a dose-dependent manner. Furthermore, in in vitro and in vivo assays, knockdown of midkine resulted in significant sensitivity to anoikis, decreased cell survival and significantly decreased tumor occurrence rate. Patients with midkine-elevated HCC had higher CTC counts and less apoptotic CTCs, as well as significantly higher recurrence rate and shorter recurrence-free interval. To understand the molecular mechanism underlying the midkine with HCC progression, we performed in vitro and in vivo studies. We found that midkine plays an important role in enhancement of HCC cell resistance to anoikis, thereby promoting subsequent metastasis. Activation of PI3K/Akt/NF-κB/TrkB signaling by midkine-activated anaplastic lymphomakinase (ALK) is responsible for anoikis resistance.
CD147 is highly expressed in hepatocellular carcinoma (HCC) and associated with the invasion and metastasis of HCC. The efficacy of I131 -metuximab (I131 -mab), a newly developed agent that targets CD147, as a radio-immunotherapy for local HCC, has been validated in clinical practice. However, the synergistic anticancer activity and molecular mechanism of different conjugated components within I131 -mab remain unclear. In this study, the cytological experiments proved that I131 -mab inhibited the proliferation and invasion of HCC cells. Mechanically, this inhibition effect was mainly mediated by the antibody component part of I131 -mab, which could reverse the epithelial-mesenchymal transition of HCC cells partially by suppressing the phosphorylation of VEGFR-2. The inhibitory effect of I131 on HCC cell proliferation and invasion is limited, whereas, when combined with metuximab, I131 significantly enhanced the sensitivity of HCC cells to CD147-mab and consequently reinforced the anticancer effects of CD147-mab, suggesting that the two components of I131 -mab exerted synergistic anti-HCC capability. Furthermore, the experiments using SMMC-7721 human HCC xenografts in athymic nude mice showed that I131 -mab and CD147-mab significantly inhibited the growth of xenograft tumors and that I131 -mab was more effective than CD147-mab. In conclusion, our results elucidated the mechanism underlying the anti-HCC effects of I131 -mab and provided a theoretical foundation for the clinical application of I131 -mab.
In diffuse large B-cell lymphoma (DLBCL), many oncogenic microRNAs (OncomiRs) are highly expressed to promote disease development and progression by inhibiting the expression and function of certain tumor suppressor genes, and these OncomiRs comprise a promising new class of molecular targets for the treatment of DLBCL. However, most current therapeutic studies have focused on a single miRNA, with limited treatment outcomes. In this study, we generated tandem sequences of 10 copies of the complementary binding sequences to 13 OncomiRs and synthesized an interfering long non-coding RNA (i-lncRNA). The highly-expressed i-lncRNA in DLBCL cells would compete with the corresponding mRNAs of OncomiR target genes for binding OncomiRs, thereby effectively consuming a large amount of OncomiRs and protecting many tumor suppressor genes. The in vitro experiments confirmed that the i-lncRNA expression significantly inhibited cell proliferation, induced cell cycle arrest and apoptosis in DLBCL cell lines, mainly through upregulating the expression of PTEN, p27(kip1), TIMP3, RECK and downregulating the expression of p38/MAPK, survivin, CDK4, c-myc. In the established SUDHL-4 xenografts in nude mice, the treatment strategy involving adenovirus-mediated i-lncRNA expression significantly inhibited the growth of DLBCL xenografts. Therefore, this treatment would specifically target the carcinogenic effects of many OncomiRs that are usually expressed in DLBCL and not in normal cells, such a strategy could improve anti-tumor efficacy and safety and may be a good prospect for clinical applications.
Sorafenib is a multikinase inhibitor for the treatment of hepatocellular carcinoma. However, most patients who initially respond to sorafenib become refractory. In a previous study, we demonstrated that sphere-forming cells derived from liver cancer cell lines possess the properties of liver cancer stem cells (LCSCs). In the present study, we found that successive passages of LCSCs were more resistant to sorafenib, and LCSCs treated with sorafenib showed an increase in spheroid formation with a lower inhibition rate. MK2206, but not various other inhibitors of cell signaling pathways, enhanced their sensitivity to sorafenib, increased the apoptotic rate, and suppressed the growth of LCSC xenografts in vivo ( P < 0.01); sorafenib treatment decreased the level of active phosphorylated (p)Akt (Thr308) and reduced the levels of active pAkt (Ser473) and extracellular signal-regulated kinase (ERK) in LCSCs, whereas MK2206 reduced pAkt expression and increased pERK expression. Cotreatment with sorafenib and MK2206 reduced pAkt and pERK expression in LCSCs and xenografted tumors ( P < 0.01). Treatment with either sorafenib or MK2206 decreased the expression of EpCAM and CD133 in LCSCs, which was more evident after combined treatment. Based on these results, we conclude that resistance to sorafenib is associated with weak ERK signaling and strong Akt signaling in LCSCs. By inhibition of Akt and upregulation of ERK, MK2206 overcomes the resistance of LCSCs to sorafenib.
Sorafenib is a multikinase inhibitor approved for the treatment of advanced hepatocellular carcinoma (HCC). However, therapeutic response to sorafenib was not equal among HCC patients. Here we present a novel system to provide quantitative information concerning sorafenib-related targets by simultaneous detection of phosphorylated ERK (pERK) and pAkt expressions in circulating tumor cells (CTCs) isolated from HCC patients. Our results showed that 90.0% of patients had a molecular classification of tissues concordant with that of CTCs. CTC counts showed a shaper decline in patients with pERK+/pAkt- CTCs after two weeks of sorafenib treatment (P < 0.01). Disease control rates were significantly different between patients with pERK+/pAkt- CTCs (11/15; 73.3%) and those without (13/44; 29.5%) (P < 0.05). Univariate and multivariate analysis indicated pERK+/pAkt- CTCs as an independent predictive factor of progression-free survival (PFS) (hazard ratio = 9.389; P < 0.01). PFS correlated with the proportion of pERK+/pAkt- CTCs (r = 0.968, P < 0.01), and was higher in patients with ≥ 40% pERK+/pAkt- CTCs compared to those with < 40% (8.4 vs. 1.3 mo; P < 0.05). In a validation set of twenty HCC patients, CTCs from patients with ≥ 40% pERK+/pAkt- CTCs had significantly higher inhibition rates of spheroid formation compared to those with < 40% (61.2 vs. 19.8%; P < 0.01). Our findings demonstrated that CTCs can be used in place of tumor tissue for characterization of pERK/pAkt expression. pERK+/pAkt- CTCs are most sensitive to sorafenib and an independent predictive factor of PFS in HCC patients treated with sorafenib.
Anoikis is a form of apoptosis which occurs when anchorage-dependent cells either show loss of adhesion or inappropriate adhesion. Only a few cancer cells that detach from the primary site of the tumor acquire the ability to resist anoikis and form metastasis. The mechanism underlying the resistance of colorectal cancer (CRC) cells to anoikis remains unclear. Interleukin-8 (alternatively known as CXCL8) is associated with CRC angiogenesis and progression. Here, we found that a high abundance of CXCL8 or TOPK strongly correlated with poor overall and disease-free survival of 186 patients with CRC. A combination of high CXCL8 and high TOPK expressions had the worst prognosis. We showed that CXCL8 expression was negatively correlated with anoikis in CRC cells. CXCL8 treatment enhanced the resistance of CRC cells to apoptosis, which was accompanied by the increase of TOPK, and the activation of AKT and ERK. Moreover, we demonstrated that the inhibition of either ERK or AKT by specific chemical inhibitors attenuated the CXCL8-mediated resistance to anoikis. Treatment with AKT inhibitor abolished the effects of CXCL8 on TOPK expression, suggesting that TOPK was downstream of AKT in the process of anoikis. Taken together, we demonstrated that CXCL8 is strongly implicated in the resistance of CRC cells to anoikis, and that the AKT, TOPK and ERK pathway may be a potential therapeutic target for CRC.
Movement of tumor cells from a primary tumor to a nonadjacent or distant site is a contiguous and complex process. Among the multiple natural cellular programs that promote initiation and progression of tumor metastasis, epithelial–mesenchymal transition (EMT) may play a key role in the ultimate generation of a metastatic foci. Acquisition of the EMT phenotype by tumor cells not only increases their migration and invasion potentials, thereby facilitating their ability to infiltrate blood vessels and to produce circulating tumor cells (CTCs), but also promotes survival of CTCs in the bloodstream and their ability to extravasate out of the circulatory system and invade proximal tissues. In organs distal to the primary tumor, the phenotypic switching mechanism of mesenchymal–epithelial transition (MET) enables CTCs to grow and colonize, enhancing the likelihood of establishing metastasis. In addition, CTCs that have undergone EMT attain increased resistance to chemotherapy and targeted therapy. CTCs with the EMT phenotype have become recognized as an active source of metastases, and targeting EMT/MET processes during the individual steps of tumor metastasis represents a promising new approach for alleviating cancer metastasis and recurrence. In this article, we focus on the biological and clinical importance of EMT and/or MET in CTCs during the individual steps of tumor metastasis, summarizing the recent findings of the regulatory roles played by EMT and/or MET in the generation, survival, and recolonization of CTCs and discussing the EMT-targeting strategies developed for tumor diagnosis as well as their potential for management of metastatic malignant diseases.
AIM To improve an asialoglycoprotein receptor (ASGPR)-based enrichment method for detection of circulating tumor cells (CTCs) of hepatocellular carcinoma (HCC). METHODS Peripheral blood samples were collected from healthy subjects, patients with HCC or various other cancers, and patients with hepatic lesions or hepatitis. CTCs were enriched from whole blood by extracting CD45-expressing leukocytes with monoclonal antibody coated-beads following density gradient centrifugation. The remaining cells were cytocentrifuged on polylysine-coated slides. Isolated cells were treated by triple immunofluorescence staining with CD45 antibody and a combination of antibodies against ASGPR and carbamoyl phosphate synthetase 1 (CPS1), used as liver-specific markers, and costained with DAPI. The cell slide was imaged and stained tumor cells that met preset criteria were counted. Recovery, sensitivity and specificity of the detection methods were determined and compared by spiking experiments with various types of cultured human tumor cell lines. Expression of ASGPR and CPS1 in cultured tumor cells and tumor tissue specimens was analyzed by flow cytometry and triple immunofluorescence staining, respectively. RESULTS CD45 depletion of leukocytes resulted in a significantly greater recovery of multiple amounts of spiked HCC cells than the ASGPR(+) selection (Ps < 0.05). The expression rates of either ASGPR or CPS1 were different in various liver cancer cell lines, ranging between 18% and 99% for ASGPR and between 9% and 98% for CPS1. In both human HCC tissues and liver cancer cell lines, there were a few HCC cells that did not stain positive for ASGPR or CPS1. The mixture of monoclonal antibodies against ASGPR and CPS1 identified more HCC cells than either antibody alone. However, these antibodies did not detect any tumor cells in blood samples spiked with the human breast cancer cell line MCF-7 and the human renal cancer cell line A498. ASGPR(+) or/and CPS1(+) CTCs were detected in 29/32 (91%) patients with HCC, but not in patients with any other kind of cancer or any of the other test subjects. Furthermore, the improved method detected a higher CTC count in all patients examined than did the previous method (P = 0.001), and consistently achieved 12%-21% higher sensitivity of CTC detection in all seven HCC patients with more than 40 CTCs. CONCLUSION Negative depletion enrichment combined with identification using a mixture of antibodies against ASGPR and CPS1 improves sensitivity and specificity for detecting circulating HCC cells.
Background: Asialoglycoprotein receptor (ASGPR)-ligand-based separation combined with identification with Hep Par 1 or pan-cytokeratin (P-CK) antibody have been demonstrated to detect circulating tumor cells (CTCs) in hepatocellular carcinoma (HCC). The aim of this study was to develop an improved enrichment and identification system that allows the detection of all types of HCC CTCs.Methods: The specificity of the prepared anti-ASGPR monoclonal antibody was characterized. HCC cells were bound by ASGPR antibody and subsequently magnetically isolated by second antibody-coated magnetic beads. Isolated HCC cells were identified by immunofluorescence staining using a combination of anti-P-CK and anti-carbamoyl phosphate synthetase 1 (CPS1) antibodies. Blood samples spiked with HepG2 cells were used to determine recovery and sensitivity. CTCs were detected in blood samples from HCC patients and other patients.Results: ASGPR was exclusively expressed in human hepatoma cell line, normal hepatocytes and HCC cells in tissue specimens detected by the ASGPR antibody staining. More HCC cells could be identified by the antibody cocktail for CPS1 and P-CK compared with a single antibody. The current approach obtained a higher recovery rate of HepG2 cells and more CTC detection from HCC patients than the previous method. Using the current method CTCs were detected in 89% of HCC patients and no CTCs were found in the other test subjects.Conclusions: Our anti-ASGPR antibody could be used for specific and efficient HCC CTC enrichment, and anti-P-CK combined with anti-CPS1 antibodies is superior to identification with one antibody alone in the sensitivity for HCC CTC detection.
The human sulfatase 1 (hSulf-1) gene encodes an endosulfatase that functions to inhibit the heparin-binding growth factor signaling, including the basic fibroblast growth factor (bFGF)-mediated pathway, by desulfating the cell surface heparan sulfate proteoglycans (HSPGs). bFGF could stimulate cell cycle progression and inhibit cell apoptosis, this biological effect can be reversed by hSulf-1. However, molecular mechanisms have not been fully reported. In the current study, by reactivation of hSulf-1 expression and function in the hSulf-1-negative hepatocellular carcinoma (HCC) cell lines and HCC xenograft tumors, we found that hSulf-1 blocked the bFGF effect on the promotion of cell cycle and inhibition of apoptosis. The bFGF-stimulated activation of protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) pathways was suppressed by hSulf-1, which led to a decreased expression of the target genes Cyclin D1 and Survivin, then finally induced cell cycle arrest and apoptosis in HCC cells. Our data suggested that hSulf-1 may be a suitable target for cancer therapy.