Sulfatase 1 (hSulf-1) reverses basic fibroblast growth factor-stimulated signaling and inhibits growth of hepatocellular carcinoma in animal model

Effects of dual-gene modification on biological characteristics of vascular endothelial cells and their significance as reserving cells for chronic wound repair

bFGF is a commonly used and reliable factor for improving chronic wound healing, and hSulf-1 expression is abundant in surrounding cells of chronic wound tissue and vascular endothelial cells, which can reverse the effect of bFGF and inhibit the signalling activity of cell proliferation. In this study, an adenovirus, Ad5F35ET1-bFGF-shSulf1, was designed for establishing the dual-gene modified vascular endothelial cells, which were used as the repair cells for skin chronic wound. Ad5F35ET1-bFGF-shSulf1 infected ECV304 cells in vitro and mediated the overexpression of bFGF and the knockdown of hSulf-1, which effectively activated the AKT and ERK signal transduction pathways, facilitate cell proliferation and migration, with the cell viability to 128.29% at 72 h after infection, compared to 66.65%, 73.74%, 87.63%, 103.14% in the blank control, Ad5F35ET1-EGFP-shNC, Ad5F35ET1-shSulf1, Ad5F35ET1-bFGF groups, respectively. In the rat ear skin injury model, the wound healing was significantly accelerated in the Ad5F35ET1-rbFGF-shrSulf1 group compared to the blank control group (p = 0.0046), Ad5F35ET1-EGFP-shNC group (p = 0.0245), Ad5F35ET1-shrSulf group (p = 0.0426), and Ad5F35ET1-rbFGF group (p = 0.2853). The results demonstrated that this strategy may be a candidate therapy for chronic injury repair.

Rs3802278 in 3'-UTR of SULF1 associated with platinum resistance and survival in Chinese epithelial ovarian cancer patients

Ovarian cancer is the leading cause of death from gynecologic cancers, but platinum resistance remains a major obstacle in the chemotherapy of ovarian cancer. This study aims to examine the role of polymorphisms in sulfatase 1 (SULF1) in platinum resistance and survival in advanced epithelial ovarian cancer (EOC) patients. We genotyped 12 SNPs of SULF1 in 195 EOC patients treated with platinum using MassARRAY method and evaluated the association between the SNPs and platinum response. SULF1 rs3802278 was marginal significantly associated with platinum resistance in recessive model with p value of 0.055. The patients with SULF1 rs3802278 AA were more resistant to platinum-based chemotherapy comparing to those with AG/GG genotype (OR: 2.317, 95%CI: 0.982 ∼ 5.465). In survival analysis, rs3802278 was significantly associated with both of PFS and OS after adjusted by FIGO stage and age. Patients with AA genotypes showed a shorter PFS and OS than with AG/GG genotypes (median PFS: 15 months vs. 21 months, p = 0.010, HR = 1.876, 95%CI: 1.165-3.022; median OS: 42 months vs. 73 months, p = 0.031, HR = 1.928, 95%CI: 1.061-3.504). SULF1 rs3802278 may serve as a potential candidate biomarker for the prediction of platinum resistance and prognosis in Chinese EOC patients.

HSulf‑1 and palbociclib exert synergistic antitumor effects on RB‑positive triple‑negative breast cancer

Human sulfatase-1 (HSulf-1) is emerging as a novel prognostic biomarker in breast cancer. Previous studies demonstrated HSulf-1 to function as a negative regulator of cyclin D1 in breast cancer. Accumulating preclinical evidence is supporting the efficacy of cyclin-dependent kinase (CDK) 4/6 inhibitors against the luminal androgen receptor sub-type of triple-negative breast cancer (TNBC). It was therefore hypothesized that HSulf-1 may cooperate with CDK4/6 inhibitors to control cell cycle progression in breast cancer cells. HSulf-1 expression was found to be downregulated in TNBC tissues and cell lines compared with that in healthy tissues and non-breast cancer cell lines, respectively. High levels of HSulf-1 expression was also found to be associated with increased progression-free survival and overall survival in patients with TNBC. Functionally, it was demonstrated that HSulf-1 served as tumor suppressor in TNBC by inducing cell cycle arrest and apoptosis whilst inhibiting proliferation, epithelial-mesenchymal transition, migration and invasion. Subsequent overexpression of HSulf-1 coupled with treatment with the CDK4/6 inhibitor palbociclib exhibited a synergistic antitumor effect on retinoblastoma (RB)-positive TNBC. Further studies revealed the mechanism underlying this cooperative antiproliferative effect involved to be due to the prohibitive effects of HSulf-1 on the palbociclib-induced accumulation of cyclin D1 through AKT/STAT3 and ERK1/2/STAT3 signaling. Taken together, findings from the present study not only suggest that HSulf-1 may be a potential therapeutic target for TNBC, but also indicate that combinatorial treatment could be an alternative therapeutic option for RB-positive TNBC, which may open novel perspectives.

Sulfatase 1 expression in pancreatic cancer and its correlation with clinicopathological features and postoperative prognosis

BACKGROUND

Recent studies have shown that Sulfatase 1 (SULF1) plays a crucial role in the genesis, development, and progression of tumors. However, there have been few studies on the role of SULF1 in pancreatic cancer.

OBJECTIVE

The present study examined the differences in SULF1 expression levels between pancreatic cancer and normal tissues, and their correlation with the clinicopathological features and prognosis.

METHODS

A total of 65 pancreatic cancer samples were enrolled in this study. An immunohistochemical assay were used in this study. The relationship between SULF1 expression and clinicopathological features were tested using χ2 test or Fisher's exact test. The Kaplan-Meier method was used to calculate the cumulative survival rates of the patients.

RESULTS

The study showed that the SULF1 expression level was higher in pancreatic cancer tissues than in normal tissues. Analysis of the clinical and pathological data of patients revealed that high SULF1 expression was associated with later T, N, and TNM stages, higher CA19-9 levels, smaller tumor size, and poorer prognosis.

CONCLUSIONS

These findings suggested that SULF1 could be an indicator of the clinicopathological features and prognosis of pancreatic cancer.

Human sulfatase 1 exerts anti-tumor activity by inhibiting the AKT/ CDK4 signaling pathway in melanoma

Human sulfatase 1 (hSulf-1) has aryl sulfatase activity. It can reduce the sulfation of cell surface heparan sulfate proteoglycan (HSPG) and inhibit various growth factor receptor-mediated signaling pathways. In most cancers, hSulf-1 is inactivated, which endows cancer cells with increasesed cell proliferation and metastatic activities, inhibition of apoptosis, and decreased sensitivity to radio- and chemotherapy. In this study, we found that hSulf-1 overexpression in melanoma cells can inhibit cell proliferation and induce cell cycle arrest and apoptosis by decreasing the protein kinase B (AKT) phosphorylation and limiting CDK4 nuclear import. We further confirmed that hSulf-1 overexpression can inhibit AKT phosphorylation and CDK4 nuclear localization and retard the growth of melanoma xenograft tumors in nude mice. Overall, hSulf-1 function in melanoma cells provides an ideal molecular treatment target. An important anti-tumor mechanism of hSulf-1 operates by decreasing downstream AKT signaling pathway activity and inhibiting the nuclear import of CDK4.

Epigenetic Regulation of the Biosynthesis & Enzymatic Modification of Heparan Sulfate Proteoglycans: Implications for Tumorigenesis and Cancer Biomarkers

Emerging evidence suggests that the enzymes in the biosynthetic pathway for the synthesis of heparan sulfate moieties of heparan sulfate proteoglycans (HSPGs) are epigenetically regulated at many levels. As the exact composition of the heparan sulfate portion of the resulting HSPG molecules is critical to the broad spectrum of biological processes involved in oncogenesis, the epigenetic regulation of heparan sulfate biosynthesis has far-reaching effects on many cellular activities related to cancer progression. Given the current focus on developing new anti-cancer therapeutics focused on epigenetic targets, it is important to understand the effects that these emerging therapeutics may have on the synthesis of HSPGs as alterations in HSPG composition may have profound and unanticipated effects. As an introduction, this review will briefly summarize the variety of important roles which HSPGs play in a wide-spectrum of cancer-related cellular and physiological functions and then describe the biosynthesis of the heparan sulfate chains of HSPGs, including how alterations observed in cancer cells serve as potential biomarkers. This review will then focus on detailing the multiple levels of epigenetic regulation of the enzymes in the heparan sulfate synthesis pathway with a particular focus on regulation by miRNA and effects of epigenetic therapies on HSPGs. We will also explore the use of lectins to detect differences in heparan sulfate composition and preview their potential diagnostic and prognostic use in the clinic.

Overexpression of sulfatase-1 in murine hepatocarcinoma Hca-F cell line downregulates mesothelin and leads to reduction in lymphatic metastasis, both in vitro and in vivo

Lymphatic vessels function as transport channels for tumor cells to metastasize from the primary site into the lymph nodes. In this experiment we evaluated the effect of Sulfatase-1 (Sulf-1) on metastasis by upregulating it in murine hepatocarcinoma cell line Hca-F with high lymph node metastatic rate of >75%. The study in vitro showed that upregulation of Sulf-1 in Hca-F cells significantly reduced cell proliferation, migration and invasion (p<0.05). Also, the forced expression of Sulf-1 downregulated Mesothelin (Msln) at both the protein and mRNA levels. The experiment in vivo further showed that up-regulation of Sulf-1 with the attendant downregulation of mesothelin delayed tumor growth and decreased lymph node metastasis. In conclusion, our findings show that Sulf-1 is an important tumor suppressor gene in hepatocellular carcinoma (HCC), and its overexpression downregulates Msln and results in a decrease in HCC cell proliferation, migration, invasion, and lymphatic metastasis. This functional relationship between Sulf-1 and Msln could be exploited for the development of a novel liver cancer therapy.

HSulf-1 deficiency dictates a metabolic reprograming of glycolysis and TCA cycle in ovarian cancer

Warburg effect has emerged as a potential hallmark of many cancers. However, the molecular mechanisms that led to this metabolic state of aerobic glycolysis, particularly in ovarian cancer (OVCA) have not been completely elucidated. HSulf-1 predominantly functions by limiting the bioavailability of heparan binding growth factors and hence their downstream signaling. Here we report that HSulf-1, a known putative tumor suppressor, is a negative regulator of glycolysis. Silencing of HSulf-1 expression in OV202 cell line increased glucose uptake and lactate production by upregulating glycolytic genes such as Glut1, HKII, LDHA, as well as metabolites. Conversely, HSulf-1 overexpression in TOV21G cells resulted in the down regulation of glycolytic enzymes and reduced glycolytic phenotype, supporting the role of HSulf-1 loss in enhanced aerobic glycolysis. HSulf-1 deficiency mediated glycolytic enhancement also resulted in increased inhibitory phosphorylation of pyruvate dehydrogenase (PDH) thus blocking the entry of glucose flux into TCA cycle. Consistent with this, metabolomic and isotope tracer analysis showed reduced glucose flux into TCA cycle. Moreover, HSulf-1 loss is associated with lower oxygen consumption rate (OCR) and impaired mitochondrial function. Mechanistically, lack of HSulf-1 promotes c-Myc induction through HB-EGF-mediated p-ERK activation. Pharmacological inhibition of c-Myc reduced HB-EGF induced glycolytic enzymes implicating a major role of c-Myc in loss of HSulf-1 mediated altered glycolytic pathway in OVCA. Similarly, PG545 treatment, an agent that binds to heparan binding growth factors and sequesters growth factors away from their ligand also blocked HB-EGF signaling and reduced glucose uptake in vivo in HSulf-1 deficient cells.

125I-labeled anti-bFGF monoclonal antibody inhibits growth of hepatocellular carcinoma

AIM: To investigate the inhibitory efficacy of ¹²⁵I-labeled anti-basic fibroblast growth factor (bFGF) monoclonal antibody (mAb) in hepatocellular carcinoma (HCC).

METHODS: bFGF mAb was prepared by using the 1G9B9 hybridoma cell line with hybridization technology and extracted from ascites fluid through a Protein G Sepharose affinity column. After labeling with ¹²⁵I through the chloramine-T method, bFGF mAb was further purified by a Sephadex G-25 column. Gamma radiation counter GC-1200 detected radioactivity of ¹²⁵I-bFGF mAb. The murine H22 HCC xenograft model was established and randomized to interventions with control (phosphate-buffered saline), ¹²⁵I-bFGF mAb, ¹²⁵I plus bFGF mAb, bFGF mAb, or ¹²⁵I. The ratios of tumor inhibition were then calculated. Expression of bFGF, fibroblast growth factor receptor (FGFR), platelet-derived growth factor, and vascular endothelial growth factor (VEGF) mRNA was determined by quantitative reverse transcriptase real-time polymerase chain reaction.

RESULTS: The purified bFGF mAb solution was 8.145 mg/mL with a titer of 1:2560000 and was stored at -20 °C. After coupling, ¹²⁵I-bFGF mAb was used at a 1: 1280000 dilution, stored at 4 °C, and its specific radioactivity was 37 MBq/mg. The corresponding tumor weight in the control, ¹²⁵I, bFGF mAb, ¹²⁵I plus bFGF mAb, and ¹²⁵I-bFGF mAb groups was 1.88 ± 0.25, 1.625 ± 0.21, 1.5 ± 0.18, 1.41 ± 0.16, and 0.98 ± 0.11 g, respectively. The tumor inhibition ratio in the ¹²⁵I, bFGF mAb, ¹²⁵I plus bFGF mAb, and ¹²⁵I-bFGF mAb groups was 13.6%, 20.2%, 25.1%, and 47.9%, respectively. Growth of HCC xenografts was inhibited significantly more in the ¹²⁵I-bFGF mAb group than in the other groups (P < 0.05). Expression of bFGF and FGFR mRNA in the ¹²⁵I-bFGF mAb group was significantly decreased in comparison with other groups (P < 0.05). Groups under interventions revealed increased expression of VEGF mRNA (except for ¹²⁵I group) compared with the control group.

CONCLUSION: ¹²⁵I-bFGF mAb inhibits growth of HCC xenografts. The coupling effect of ¹²⁵I-bFGF mAb is more effective than the concomitant use of ¹²⁵I and bFGF mAb.

SULF1/SULF2 reactivation during liver damage and tumour growth

Both SULF1 and SULF2 enzymes are undetectable in normal adult liver tissue despite their high level expression during foetal development. Most hepatocellular carcinomas unlike the normal adult liver, however, express variable levels of these enzymes with a small proportion not expressing either SULF1 or SULF2. SULF1 expression, however, is not restricted to only foetal and tumour tissues but is also abundant in liver tissues undergoing injury-induced tissue regeneration as we observed during fatty liver degeneration, chronic hepatitis and cirrhosis. Unlike SULF1, the level of SULF2 activation during injury-induced regeneration, however, is much lower when compared to foetal or tumour growth. Although a small fraction of liver tumours and some liver tumour cell lines can grow in the absence of Sulf1 and/or Sulf2, the in vitro overexpression of these genes further confirms their growth-promoting effect while transient reduction in their levels by neutralisation antibodies reduces growth. Hedgehog signalling appeared to regulate the growth of both Hep3B and PRF5 cell lines since cyclopamine demonstrated a marked inhibitory effect while sonic hedgehog (SHH) overexpression promoted growth. All Sulf isoforms promoted SHH-induced growth although the level of increase in PRF5 cell line was higher with both Sulf2 variants than Sulf1. In addition to promoting growth, the Sulf variants, particularly the shorter Sulf2 variant, markedly promoted PRF5 cell migration in a scratch assay. The SULF1/SULF2 activation thus does not only promote regulated foetal growth and injury-induced liver regeneration but also dysregulated tumour growth.

Metformin and AICAR regulate NANOG expression via the JNK pathway in HepG2 cells independently of AMPK

NANOG, a marker of stemness, impacts tumor progression and therapeutic resistance in cancer cells. In human hepatocellular carcinoma (HCC), upregulation of NANOG is associated with metastasis and a low survival rate, while its downregulation results in a lower colony formation rate and enhanced chemosensitivity. Metformin, an agent widely used for diabetes treatment, and AICAR, another AMP-activated protein kinase (AMPK) activator, have been reported to inhibit the growth of several types of cancer. Although inhibitory effects of metformin on NANOG in pancreatic cancer cells and of AICAR in mouse embryonic stem cells have been described, the underlying molecular mechanisms remain uncertain in HCC. In this study, we used the HepG2 cell line and found that metformin/AICAR downregulated NANOG expression with decreased cell viability and enhanced chemosensitivity to 5-fluorouracil (5-FU). Moreover, metformin/AICAR inhibited c-Jun N-terminal kinase (JNK) activity, and blockade of either the JNK MAPK pathway or knockdown of JNK1 gene expression reduced NANOG levels. The upregulation of NANOG and phospho-JNK by basic fibroblast growth factor (bFGF) was abrogated by metformin/AICAR. Additionally, although transient upregulation of NANOG within 2 h of treatment with metformin/AICAR was concordant with both JNK and AMPK activation, increased NANOG expression with activation of JNK was also observed following AMPK inhibition with compound C. Taken together, our data suggest that metformin/AICAR regulate NANOG expression via the JNK MAPK pathway in HepG2 cells independently of AMPK, and that this JNK/NANOG signaling pathway may offer new therapeutic strategies for the treatment of HCC.

Survivin in survival of hepatocellular carcinoma

Survivin is an anti-apoptotic protein belonging to the inhibitor of apoptosis protein (IAP) family. It is involved in the regulation of important physiological and pathological processes in cells and functions to inhibit cell apoptosis and promote cell proliferation. Normally and terminally differentiated tissues are nearly negative for survivin. In contrast, survivin is highly expressed in most human tumor tissues, including hepatocellular carcinoma (HCC). The abnormal overexpression of survivin is closely related to the malignant biological behaviors of tumors. During the development and progression of HCC, the high level of survivin expression promotes cancer cell proliferation, inhibits cancer cell apoptosis, induces tumor stromal angiogenesis, reduces the sensitivity of cancer cells to radiotherapy and chemotherapy, and ultimately affects the prognosis of patients with HCC. Survivin expression is regulated by a large number of factors. The latest discovery indicated that the transcription factor octamer-binding transcription factor 4 (OCT4) enhances the expression of survivin though cyclin D1 (CCND1), which, in part, accounts for tumor cell proliferation, recurrence and metastasis. Survivin plays key roles in HCC, which renders it an ideal target for the treatment of HCC. The present article reviews the research progress on the relationship between survivin and HCC and on the HCC treatment strategies targeting survivin.