Involvement of SULF2 in y-irradiation-induced invasion and resistance of cancer cells by inducing IL-6 expression

Myeloid Deficiency of Heparan Sulfate 6-O-Endosulfatases Impairs Bone Marrow Hematopoiesis

The heparan sulfate (HS) 6-O-endosulfatases or the Sulfs (Sulf1 and Sulf2) are the only known enzymes that can modify HS sulfation status extracellularly and have been shown to regulate diverse biological processes. The role of the Sulfs in bone marrow (BM) hematopoiesis is not known. In this study, we generated a novel mouse line with myeloid-specific deletion of the Sulfs by crossing Sulf1/2 double floxed mice with the LysM-cre line. The LysM-Sulf knockout (KO) male mice exhibited age-dependent expansion of hematopoietic stem cells and the granulocyte-monocyte lineages in the BM, whereas common lymphoid progenitors and B lymphocyte populations were significantly reduced. Although megakaryocytic and erythroid progenitors were not reduced in the BM, the LysM-Sulf KO males suffered age-dependent reduction of red blood cells (RBCs) and platelets in the peripheral blood, suggesting that the production of RBCs and platelets was arrested at later stages. In addition, LysM-Sulf KO males displayed progressive splenomegaly with extramedullary hematopoiesis. Compared to males, LysM-Sulf KO females exhibited a much-reduced phenotype, and ovariectomy had little effect. Mechanistically, reduced TGF-β/Smad2 but enhanced p53/p21 signaling were observed in male but not female LysM-Sulf KO mice. Finally, HS disaccharide analysis via LC-MS/MS revealed increased HS 6-O-sulfation in the BM from both male and female LysM-Sulf KO mice, however, the distribution of 6-O-sulfated motifs were different between the sexes with compensatory increase in Sulf1 expression observed only in LysM-Sulf KO females. In conclusion, our study reveals that myeloid deficiency of the Sulfs leads to multilineage abnormalities in BM hematopoiesis in an age- and sex-dependent manner.

Combination of radiotherapy and immunotherapy in duality with the protumoral action of radiation

Radiotherapy is widely used to treat various cancers. Its combination with immune checkpoint inhibitors is intensively studied preclinically and clinically. Although the first results were very encouraging, the number of patients who respond positively remains low, and the therapeutic benefit is often temporary. This review summarizes how radiation can stimulate an antitumor immune response and its combination with immunotherapy based on inhibiting immune checkpoints. We will provide an overview of radiotherapy parameters that should be better controlled to avoid downregulating the antitumor immune response. The low response rate of combining radiotherapy and immunotherapy could, at least in part, be caused by the stimulation of cancer cell invasion and metastasis development that occur at similar doses and number of radiation fractions. To end on a positive note, we explore how a targeted inhibition of the inflammatory cytokines induced by radiation with a cyclooxygenase-2 inhibitor could both support an antitumor immune response and block radiation-induced metastasis formation.

6-O-endosulfatases in tumor metastasis: heparan sulfate proteoglycans modification and potential therapeutic targets

Metastasis is the leading cause of cancer-associated mortality. Although advances in the targeted treatment and immunotherapy have improved the management of some cancers, the prognosis of metastatic cancers remains unsatisfied. Therefore, the specific mechanisms in tumor metastasis need further investigation. 6-O-endosulfatases (SULFs), comprising sulfatase1 (SULF1) and sulfatase 2 (SULF2), play pivotal roles in the post-synthetic modifications of heparan sulfate proteoglycans (HSPGs). Consequently, these extracellular enzymes can regulate a variety of downstream pathways by modulating HSPGs function. During the past decades, researchers have detected the expression of SULF1 and SULF2 in most cancers and revealed their roles in tumor progression and metastasis. Herein we reviewed the metastasis steps which SULFs participated in, elucidated the specific roles and mechanisms of SULFs in metastasis process, and discussed the effects of SULFs in different types of cancers. Moreover, we summarized the role of targeting SULFs in combination therapy to treat metastatic cancers, which provided some novel strategies for cancer therapy.

Antimetastatic activity of seongsanamide B in γ-irradiated human lung cancer

Lung cancer, which has a high incidence and mortality rates, often metastasizes and exhibits resistance to radiation therapy. Seongsanamide B has conformational features that suggest it has therapeutic potential; however, its antitumor activity has not yet been reported. We evaluated the possibility of seongsanamide B as a radiation therapy efficiency enhancer to suppress γ-irradiation-induced metastasis in non-small cell lung cancer. Seongsanamide B suppressed non-small cell lung cancer cell migration and invasion caused by γ-irradiation. Furthermore, it suppressed γ-irradiation-induced upregulation of Bcl-XL and its downstream signaling molecules, such as superoxide dismutase 2 (SOD2) and phosphorylated Src, by blocking the nuclear translocation of phosphorylated STAT3. Additionally, seongsanamide B markedly modulated the γ-irradiation-induced upregulation of E-cadherin and vimentin. Consistent with the results obtained in vitro, while seongsanamide B did not affect xenograft tumor growth, it significantly suppressed γ-irradiation-induced metastasis by inhibiting Bcl-XL/SOD2/phosphorylated-Src expression and modulating E-cadherin and vimentin expression in a mouse model. Thus, seongsanamide B may demonstrate potential applicability as a radiation therapy efficiency enhancer for lung cancer treatment.

Sulfatase-2 from Cancer Associated Fibroblasts: An Environmental Target for Hepatocellular Carcinoma?

Introduction

Heparin sulphate proteoglycans in the liver tumour microenvironment (TME) are key regulators of cell signalling, modulated by sulfatase-2 (SULF2). SULF2 overexpression occurs in hepatocellular carcinoma (HCC). Our aims were to define the nature and impact of SULF2 in the HCC TME.

Methods

In liver biopsies from 60 patients with HCC, expression and localization of SULF2 were analysed associated with clinical parameters and outcome. Functional and mechanistic impacts were assessed with immunohistochemistry (IHC), in silico using The Cancer Genome Atlas (TGCA), in primary isolated cancer activated fibroblasts, in monocultures, in 3D spheroids, and in an independent cohort of 20 patients referred for sorafenib. IHC targets included αSMA, glypican-3, β-catenin, RelA-P-ser536, CD4, CD8, CD66b, CD45, CD68, and CD163. SULF2 impact of peripheral blood mononuclear cells was assessed by migration assays, with characterization of immune cell phenotype using fluorescent activated cell sorting.

Results

We report that while SULF2 was expressed in tumour cells in 15% (9/60) of cases, associated with advanced tumour stage and type 2 diabetes, SULF2 was more commonly expressed in cancer-associated fibroblasts (CAFs) (52%) and independently associated with shorter survival (7.2 vs. 29.2 months, p = 0.003). Stromal SULF2 modulated glypican-3/β-catenin signalling in vitro, although in vivo associations suggested additional mechanisms underlying the CAF-SULF2 impact on prognosis. Stromal SULF2 was released by CAFS isolated from human HCC. It was induced by TGFβ1, promoted HCC proliferation and sorafenib resistance, with CAF-SULF2 linked to TGFβ1 and immune exhaustion in TGCA HCC patients. Autocrine activation of PDGFRβ/STAT3 signalling was evident in stromal cells, with the release of the potent monocyte/macrophage chemoattractant CCL2 in vitro. In human PBMCs, SULF2 preferentially induced the migration of macrophage precursors (monocytes), inducing a phenotypic change consistent with immune exhaustion. In human HCC tissues, CAF-SULF2 was associated with increased macrophage recruitment, with tumouroid studies showing stromal-derived SULF2-induced paracrine activation of the IKKβ/NF-κB pathway, tumour cell proliferation, invasion, and sorafenib resistance.

Conclusion

SULF2 derived from CAFs modulates glypican-3/β-catenin signalling but also the HCC immune TME, associated with tumour progression and therapy resistance via activation of the TAK1/IKKβ/NF-κB pathway. It is an attractive target for combination therapies for patients with HCC.

Dendrobine Inhibits γ-Irradiation-Induced Cancer Cell Migration, Invasion and Metastasis in Non-Small Cell Lung Cancer Cells

The use of ionizing radiation (IR) during radiotherapy can induce malignant effects, such as metastasis, which contribute to poor prognoses in lung cancer patients. Here, we explored the ability of dendrobine, a plant-derived alkaloid from Dendrobium nobile, to improve the efficacy of radiotherapy in non-small cell lung cancer (NSCLC). We employed Western blotting, quantitative real-time (qRT)-PCR, transwell migration assays, and wound-healing assays to determine the effects of dendrobine on the migration and invasion of A549 lung cancer cells in vitro. Dendrobine (5 mm) inhibited γ-irradiation-induced migration and invasion of A549 cells by suppressing sulfatase2 (SULF2) expression, thus inhibiting IR-induced signaling. To investigate the inhibitory effects of dendrobine in vivo, we established a mouse model of IR-induced metastasis by injecting BALB/c nude mice with γ-irradiated A549 cells via the tail vein. As expected, injection with γ-irradiated cells increased the number of pulmonary metastatic nodules in mice (0 Gy/DPBS, 9.8 ± 1.77; 2 Gy/DPBS, 20.87 ± 1.42), which was significantly reduced with dendrobine treatment (2 Gy/Dendrobine, 10.87 ± 0.71), by prevention of IR-induced signaling. Together, these findings demonstrate that dendrobine exerts inhibitory effects against γ-irradiation-induced invasion and metastasis in NSCLC cells in vitro and in vivo at non cytotoxic concentrations. Thus, dendrobine could serve as a therapeutic enhancer to overcome the malignant effects of radiation therapy in patients with NSCLC.

Genomic Instability Is an Early Event in Aluminium-Induced Tumorigenesis

Genomic instability is generally considered as a hallmark of tumorigenesis and a prerequisite condition for malignant transformation. Aluminium salts are suspected environmental carcinogens that transform mammary epithelial cells in vitro through unknown mechanisms. We report here that long-term culture in the presence of aluminium chloride (AlCl₃) enables HC11 normal mouse mammary epithelial cells to form tumours and metastases when injected into the syngeneic and immunocompetent BALB/cByJ strain. We demonstrate that AlCl₃ rapidly increases chromosomal structural abnormalities in mammary epithelial cells, while we failed to detect direct modulation of specific mRNA pathways. Our observations provide evidence that clastogenic activity—a well-recognized inducer of genomic instability—might account in part for the transforming abilities of aluminium in mammary epithelial cells.

Inhibitory Effects of Furanocoumarins From the Roots ofAngelica dahuricaon Ionizing Radiation-Induced Migration of A549 Human Non-Small Cell Lung Cancer Cells

Radiation therapy is a very effective tool for the treatment of advanced human lung cancers. However, as one of its malignancy-promoting behaviors, ionizing radiation (IR) increases cell migration and radiation resistance in several lung cancer cells, including non-small cell lung cancer (NSCLC) cells. As part of our ongoing search for potent radiotherapy enhancers from medicinal herbs, a chloroform-soluble fraction of the roots of Angelica dahurica was subjected to phytochemical investigation, leading to the isolation of 8 furanocoumarins. Of these, psoralen (1), xanthotoxin (2), and bergapten (3) inhibited IR-induced migration at a non-cytotoxic concentration (50 μM) in human NSCLC A549 cells. This study is the first to report on the inhibitory activities of these constituents of A. dahurica against IR-induced cancer metastasis.

Targeting acquired oncogenic burden in resilient pancreatic cancer: a novel benefit from marine polyphenols

The upsurge of marine-derived therapeutics for cancer treatment is evident, with many drugs in clinical use and in clinical trials. Seaweeds harbor large amounts of polyphenols and their anti-cancer benefit is linear to their anti-oxidant activity. Our studies identified three superlative anti-cancer seaweed polyphenol drug candidates (SW-PD). We investigated the acquisition of oncogenic burden in radiation-resilient pancreatic cancer (PC) that could drive tumor relapse, and elucidated the efficacy of SW-PD candidates as adjuvants in genetically diverse in vitro systems and a mouse model of radiation-residual disease. QPCR profiling of 88 oncogenes in therapy-resilient PC cells identified a 'shared' activation of 40 oncogenes. SW-PD pretreatment inflicted a significant mitigation of acquired (shared) oncogenic burden, in addition to drug- and cell-line-specific repression signatures. Tissue microarray with IHC of radiation-residual tumors in mice signified acquired cellular localization of key oncoproteins and other critical architects. Conversely, SW-PD treatment inhibited the acquisition of these critical drivers of tumor genesis, dissemination, and evolution. Heightened death of resilient PC cells with SW-PD treatment validated the translation aspects. The results defined the acquisition of oncogenic burden in resilient PC and demonstrated that the marine polyphenols effectively target the acquired oncogenic burden and could serve as adjuvant(s) for PC treatment.

Mitochondrial superoxide dismutase 2 mediates γ-irradiation-induced cancer cell invasion

Sublethal doses of γ-rays promote cancer cell invasion by stimulating a signaling pathway that sequentially involves p53, sulfatase 2 (SULF2), β-catenin, interleukin-6 (IL-6), signal transducer and activator of transcription 3 (STAT3), and Bcl-X_L. Given that Bcl-X_L can increase O₂^•− production by stimulating respiratory complex I, the possible role of mitochondrial reactive oxygen species (ROS) in γ-irradiation-induced cell invasion was investigated. Indeed, γ-irradiation promoted cell invasion by increasing mitochondrial ROS levels, which was prevented by metformin, an inhibitor of complex I. γ-Irradiation-stimulated STAT3 increased the expression of superoxide dismutase 2 (SOD2), a mitochondrial enzyme that catalyzes the conversion of O₂^•− to hydrogen peroxide (H₂O₂). In contrast to O₂^•−, H₂O₂ functions as a signaling molecule. γ-Irradiation consistently stimulated the Src-dependent invasion pathway in a manner dependent on both complex I and SOD2. SOD2 was also essential for the invasion of un-irradiated cancer cells induced by upregulation of Bcl-X_L, an intracellular oncogene, or extracellular factors, such as SULF2 and IL-6. Overall, these data suggested that SOD2 is critical for the malignant effects of radiotherapy and tumor progression through diverse endogenous factors.

A drug usually used to treat type 2 diabetes may also help to prevent cancer relapse following radiotherapy, which is commonly used to kill cancer cells. However, any tumor cells that survive radiation are highly invasive, sometimes causing tumors to spread. Hong-Duck Um and co-workers at the Korea Institute of Radiological & Medical Sciences in Seoul, South Korea, noticed that the surviving cells often showed higher levels of a key enzyme, superoxide dismutase 2 (SOD2), which is involved in energy production in the cellular powerhouse, the mitochondria. Artificially increasing levels of SOD2, without radiation, made cells more invasive. Treatment with metformin, which prevents production of the molecule that SOD2 acts on, prevented cells from becoming invasive. SOD2 has been implicated in many cancers, and is therefore a very promising therapeutic target.

Linarin inhibits radiation-induced cancer invasion by downregulating MMP-9 expression via the suppression of NF-κB activation in human non-small-cell lung cancer A549

Radiotherapy is routinely used in the treatment of lung cancer patients. However, it often causes malignant effects, such as promoting cancer cell migration and invasion. Previous studies demonstrated that ionizing radiation (IR) promotes cancer cell invasion by stimulating the β-catenin, IL-6, STAT3, and Bcl-X_L signaling pathway or the PI3K, Akt, and NF-κB signaling pathway. Both Bcl-X_L and NF-κB stimulate the secretion of matrix metalloproteases (MMPs), including MMP-2 and MMP-9. In the present study, linarin isolated from Chrysanthemum morifolium flowers significantly decreased the IR-induced cell migration and invasion at a concentration of 5 μM in A549 cells. This effect was mediated via MMP-9 downregulation and the suppression of NF-κB activation by inhibiting NF-κB and IκB-α phosphorylation. However, linarin did not affect the STAT3/Bcl-X_L pathway or the stabilization of β-catenin. Overall, these results suggest that linarin repressed the MMP-9-dependent invasion pathway by regulating NF-κB activity, thereby inhibiting IR-induced cancer metastasis.

Bi-directional roles of IRF-1 on autophagy diminish its prognostic value as compared with Ki67 in liver transplantation for hepatocellular carcinoma

The prognostic values of IRF-1 and Ki-67 for liver transplantation (LT) of hepatocellular carcinoma (HCC) were investigated, as well as the mechanisms of IRF-1 in tumor suppression. Adult orthotropic liver transplantation cases (N = 127) were involved in the analysis. A significant decreased recurrence free survival (RFS) was found in the Ki-67 positive groups. Ki-67, tumor microemboli, the Milan and UCSF criteria were found to be independent risk factors for RFS. In LT for HCC beyond the Milan criteria, a significant decrease in RFS was found in the IRF-1 negative groups. In SK-Hep1 cells, an increase in apoptosis and decrease in autophagy were observed after IFN-γ stimulation, which was accompanied with increasing IRF-1 levels. When IRF-1 siRNA or a caspase inhibitor were used, reductions in LC3-II were diminished or disappeared after IFN-γ stimulation, suggesting that IFN-γ inhibited autophagy via IRF-1 expression and caspase activation. However, after IRF-1 siRNA was introduced, a reduction in LC3-II was found. Thus basic expression of IRF-1 was also necessary for autophagy. IRF-1 may be used as a potential target for HCC treatment based on its capacity to affect apoptosis and autophagy. Ki-67 shows great promise for the prediction of HCC recurrence in LT and can be used as an aid in the selection of LT candidates.

Epithelial Deletion of Sulf2 Exacerbates Bleomycin-Induced Lung Injury, Inflammation, and Mortality

Epithelial injury has been proposed to be the initiating factor in the pathogenesis of idiopathic pulmonary fibrosis (IPF). We have shown previously that heparan sulfate 6-O-endosulfatase (Sulf) 2 is overexpressed in the hyperplastic type II alveolar epithelial cells (AECs) in the IPF lungs. By removing 6-O-sulfates from specific heparan sulfate intrachain sites, Sulf2 modulates the functions of many growth factors and cytokines. In this study, we hypothesized that Sulf2 plays a regulatory role in alveolar epithelial injury and repair, using the murine bleomycin model. Consistent with our findings in human IPF lungs, bleomycin treatment in mice resulted in up-regulation of Sulf2 mRNA in whole-lung extracts and overexpression of Sulf2 protein in type II AECs on lung tissue sections. Sulf2 protein was detectable in bronchoalveolar lavage fluid at baseline, and its level was significantly increased after bleomycin exposure. To study the role of Sulf2 in alveolar injury and repair in vivo, we generated a doxycycline-inducible epithelial-specific Sulf2 conditional knockout (Sulf2 CKO) mouse line. After bleomycin exposure, Sulf2 CKO mice exhibited enhanced neutrophil infiltration in the lung, with elevated levels of total protein, lactate dehydrogenase, and cytokines (granulocyte colony-stimulating factor and interferon-γ-inducible protein 10) in bronchoalveolar lavage fluid compared with wild-type littermates. We further showed that both the p53-p21 DNA damage response and the transforming growth factor-β1 signaling pathway were up-regulated in Sulf2 CKO mice compared with wild-type. Finally, Sulf2 CKO mice suffered increased mortality after bleomycin exposure. In conclusion, Sulf2 expression in type II AECs plays a protective role in epithelial injury, inflammation and mortality.

Tumor cell intravasation

The process of entering the bloodstream, intravasation, is a necessary step in the development of distant metastases. The focus of this review is on the pathways and molecules that have been identified as being important based on current in vitro and in vivo assays for intravasation. Properties of the vasculature which are important for intravasation include microvessel density and also diameter of the vasculature, with increased intravasation correlating with increased vessel diameter in some tumors. TGFB signaling can enhance intravasation at least in part through induction of EMT, and we discuss other TGFB target genes that are important for intravasation. In addition to TGFB signaling, a number of studies have demonstrated that activation of EGF receptor family members stimulates intravasation, with downstream signaling through PI3K, N-WASP, RhoA, and WASP to induce invadopodia. With respect to proteases, there is strong evidence for contributions by uPA/uPAR, while the roles of MMPs in intravasation may be more tumor specific. Other cells including macrophages, fibroblasts, neutrophils, and platelets can also play a role in enhancing tumor cell intravasation. The technology is now available to interrogate the expression patterns of circulating tumor cells, which will provide an important reality check for the model systems being used. With a better understanding of the mechanisms underlying intravasation, the goal is to provide new opportunities for improving prognosis as well as potentially developing new treatments.