Functional expression of CXC chemokine recepter-4 mediates the secretion of matrix metalloproteinases from mouse hepatocarcinoma cell lines with different lymphatic metastasis ability

Chemokines in hepatocellular carcinoma: a meta-analysis

Accumulating evidence suggests that chemokines may play an important role in the formation and mediating of the immune microenvironment of hepatocellular carcinoma (HCC). The purpose of this meta-analysis was to explore the differences in blood or tissues chemokines concentrations between HCC patients and controls. Online databases, namely PubMed, Web of Science, Embase and Cochrane Library, were systematically searched for relevant articles published on or before 15 January 2020. Standardized mean differences (SMDs) with corresponding 95% confidence intervals of the chemokines concentrations were calculated as group differences between the HCC patients and the controls. Sixty-five studies met the inclusion criteria for the meta-analysis. Altogether they consisted of 26 different chemokines compared between 5828 HCC patients and 4909 controls; and 12 different chemokines receptors compared between 2053 patients and 2285 controls. The results of meta-analysis indicated that concentrations of CCL20, CXCL8 and CXCR4 in the HCC patients were significantly higher than those in the controls (SMD of 6.18, 1.81 and 1.04, respectively). Therefore, higher concentration levels of CCL20, CXCL8 and CXCR4 may indicate the occurrence of HCC Future research should explore the putative mechanisms underlying this linkage. Meanwhile, attempts can be made to replicate the existing findings in prospective cohort populations and explore the cause-and-effect relationships pertaining to this linkage in order to develop new diagnostic and therapeutic strategies for HCC.

"Complimenting the Complement": Mechanistic Insights and Opportunities for Therapeutics in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and a leading cause of death in the US and worldwide. HCC remains a global health problem and is highly aggressive with unfavorable prognosis. Even with surgical interventions and newer medical treatment regimens, patients with HCC have poor survival rates. These limited therapeutic strategies and mechanistic understandings of HCC immunopathogenesis urgently warrant non-palliative treatment measures. Irrespective of the multitude etiologies, the liver microenvironment in HCC is intricately associated with chronic necroinflammation, progressive fibrosis, and cirrhosis as precedent events along with dysregulated innate and adaptive immune responses. Central to these immunological networks is the complement cascade (CC), a fundamental defense system inherent to the liver which tightly regulates humoral and cellular responses to noxious stimuli. Importantly, the liver is the primary source for biosynthesis of >80% of complement components and expresses a variety of complement receptors. Recent studies implicate the complement system in liver inflammation, abnormal regenerative responses, fibrosis, carcinogenesis, and development of HCC. Although complement activation differentially promotes immunosuppressive, stimulant, and angiogenic microenvironments conducive to HCC development, it remains under-investigated. Here, we review derangement of specific complement proteins in HCC in the context of altered complement regulatory factors, immune-activating components, and their implications in disease pathogenesis. We also summarize how complement molecules regulate cancer stem cells (CSCs), interact with complement-coagulation cascades, and provide therapeutic opportunities for targeted intervention in HCC.

Exosomes and Hepatocellular Carcinoma: From Bench to Bedside

As hepatocellular carcinoma (HCC) usually occurs in the background of cirrhosis, which is an end-stage form of liver diseases, treatment options for advanced HCC are limited, due to poor liver function. The exosome is a nanometer-sized membrane vesicle structure that originates from the endosome. Exosome-mediated transfer of proteins, DNAs and various forms of RNA, such as microRNA (miRNA), long noncoding RNA (lncRNA) and messenger RNA (mRNA), contributes to the development of HCC. Exosomes mediate communication between both HCC and non-HCC cells involved in tumor-associated cells, and several molecules are implicated in exosome biogenesis. Exosomes may be potential diagnostic biomarkers for early-stage HCC. Exosomal proteins, miRNAs and lncRNAs could provide new biomarker information for HCC. Exosomes are also potential targets for the treatment of HCC. Notably, further efforts are required in this field. We reviewed recent literature and demonstrated how useful exosomes are for diagnosing patients with HCC, treating patients with HCC and predicting the prognosis of HCC patients.

Expression of CXCL12 and its receptor CXCR4 in patients with adenomyosis

The aim of the present study was to investigate the role of chemokine (C-X-C motif) ligand 12 (CXCL12) and its receptor, chemokine (C-X-C motif) receptor 4 (CXCR4) in the pathogenesis of adenomyosis (AD). Immunohistochemistry and reverse transcription-quantitative polymerase chain reaction analysis were used to measure the protein and mRNA expression of CXCL12 and CXCR4 in eutopic endometrial and ectopic foci tissue samples. Samples from a total of 36 patients with AD (study group) were compared with endometrial tissue samples from 33 patients who underwent uterine fibroids surgery (control group) during the same period. All data are presented as the mean ± standard deviation and were analyzed with SPSS software (version 16.0). Analysis of variance was used for between group analysis and pairwise comparison was performed using Fisher's least significant difference post hoc test. The results of the present study revealed that CXCL12 and CXCR4 protein expression was significantly increased in ectopic foci tissue compared with eutopic endometrial tissue samples from patients with AD. CXCL12 and CXCR4 protein expression in ectopic foci and eutopic endometrial tissue samples were significantly increased compared with the control group (P<0.05 for between group comparisons). No significant differences were identified in CXCL12 and CXCR4 protein expression between the proliferative and secretory phases within each group. Furthermore, CXCL12 and CXCR4 mRNA expression was significantly increased in ectopic foci tissue and eutopic endometrial tissue compared with the control group (P<0.05 for between group comparisons). CXCL12 mRNA expression was markedly increased in ectopic foci tissue compared with eutopic endometrial tissue of patients with AD. The expression of CXCR4 mRNA was significantly increased in eutopic endometrial tissue compared with ectopic foci tissue and the control group (P<0.05 for between group comparisons). No significant differences were identified in CXCL12 and CXCR4 mRNA expression between proliferative and secretory phase within each group. In conclusion, CXCL12 and CXCR4 may induce the ectopia, and promote the spread and localized growth of endometrial cells in the development of AD.

Sialylated β1, 6 branched N-glycans modulate the adhesion, invasion and metastasis of hepatocarcinoma cells

The mouse hepatocarcinoma cell lines Hca-F and Hca-P have been derived from hepatocarcinoma in mice and metastasize only to the lymph node. Hca-F cells displayed greater lymphatic metastasis ability than Hca-P cells. When the two cell lines were compared for cell surface sialylated β1,6 branched N-glycans by flow cytometry using L-PHA and SNA, Hca-F cells were found to express significantly higher levels. To explore the effect of increased sialylated β1,6 branched N-glycans on hepatocarcinoma progression, we inhibit their expression in Hca-F cells by using swainsonine treatment and RNA interference. We found that swainsonine treatment or GnT-V-shRNA transfection significantly inhibited the formation of β1,6 branched N-glycans, and partially inhibited the expression of α2,6 sialic acids. Knockdown of sialylated β1,6 branched N-glycans significantly attenuated the invasive and metastatic capability both in vitro and in vivo. Blockade of α2,6 sialic acid expression on Hca-F cell surface by the treatment with neuraminidase caused reduction in cellular adherence to lymph node. In addition, knockdown of sialylated β1,6 branched N-glycans could decrease the expression of Notch1, NICD1, NICD2 and HES1 in Hca-F cells. Collectively, these findings suggest that increased sialylated β1,6 branched N-glycans may contribute to hepatocarcinoma progression by altering the adhesive, invasive and metastatic ability to lymph node via Notch signaling pathway.

Silencing of ST6GalNAc I suppresses the proliferation, migration and invasion of hepatocarcinoma cells through PI3K/AKT/NF-κB pathway

ST6GalNAc I is the major Sialyl-Tn antigen (STn) synthase that is highly correlated with tumor invasion and metastasis. However, the roles and molecular mechanisms by which ST6GalNAc I mediates the malignant phenotypes of hepatocarcinoma cells still remain poorly unknown. In this study, we investigated the expression of STn and ST6GalNAc I in mouse hepatocarcinoma cell lines Hca-F, Hca-P, and Hepa1-6, which have different metastatic potential, as compared with normal mouse liver cell line IAR-20. The results showed that the expression of ST6GalNAc I and STn in Hca-F and Hca-P cells was much higher than that in Hepa1-6 and IAR20 cells. Knockdown of ST6GalNAc I by shRNA in Hca-F cells significantly decreased the expression of STn and inhibited the growth of tumor cells in vitro and in vivo. This reduction of ST6GalNAc I expression also led to the decreased migration and invasion of Hca-F cells. Furthermore, we found that ST6GalNAc I knockdown inhibited the expression levels of PI3k, p-Akt473, p-Akt308, NF-κB, and their downstream molecules. Together, our results suggest a role of ST6GalNAc I in promoting the growth and invasion of hepatocarcinoma cells through regulating PI3K/AKT signaling, and ST6GalNAc I might be a promising marker for the prognosis and therapy of hepatocarcinoma.

Targeting chemokine receptor CXCR4 for treatment of HIV-1 infection, tumor progression, and metastasis

The chemokine receptor CXCR4 is required for the entry of human immunodeficiency virus type 1 (HIV-1) into target cells and for the development and dissemination of various types of cancers, including gastrointestinal, cutaneous, head and neck, pulmonary, gynecological, genitourinary, neurological, and hematological malignancies. The T-cell (T)-tropic HIV-1 strains use CXCR4 as the entry coreceptor; consequently, multiple CXCR4 antagonistic inhibitors have been developed for the treatment of acquired immune deficiency syndrome (AIDS). However, other potential applications of CXCR4 antagonists have become apparent since its discovery in 1996. In fact, increasing evidence demonstrates that epithelial and hematopoietic tumor cells exploit the interaction between CXCR4 and its natural ligand, stromal cellderived factor (SDF)-1α, which normally regulates leukocyte migration. The CXCR4 and/or SDF-1α expression patterns in tumor cells also determine the sites of metastatic spread. In addition, the activation of CXCR4 by SDF-1α promotes invasion and proliferation of tumor cells, enhances tumor-associated neoangiogenesis, and assists in the degradation of the extracellular matrix and basement membrane. As such, the evaluation of CXCR4 and/or SDF-1α expression levels has a significant prognostic value in various types of malignancies. Several therapeutic challenges remain to be overcome before the use of CXCR4 inhibitors can be translated into clinical practice, but promising preclinical data demonstrate that CXCR4 antagonists can mobilize tumor cells from their protective microenvironments, interfere with their metastatic and tumorigenic potentials, and/or make tumor cells more susceptible to chemotherapy.

The lymphatic system and pancreatic cancer

This review summarizes current knowledge of the biology, pathology and clinical understanding of lymphatic invasion and metastasis in pancreatic cancer. We discuss the clinical and biological consequences of lymphatic invasion and metastasis, including paraneoplastic effects on immune responses and consider the possible benefit of therapies to treat tumors that are localized to lymphatics. A review of current techniques and methods to study interactions between tumors and lymphatics is presented.

The intricate role of CXCR4 in cancer

Chemokines mediate numerous physiological and pathological processes related primarily to cell homing and migration. The chemokine CXCL12, also known as stromal cell-derived factor-1, binds the G-protein-coupled receptor CXCR4, which, through multiple divergent pathways, leads to chemotaxis, enhanced intracellular calcium, cell adhesion, survival, proliferation, and gene transcription. CXCR4, initially discovered for its involvement in HIV entry and leukocytes trafficking, is overexpressed in more than 23 human cancers. Cancer cell CXCR4 overexpression contributes to tumor growth, invasion, angiogenesis, metastasis, relapse, and therapeutic resistance. CXCR4 antagonism has been shown to disrupt tumor-stromal interactions, sensitize cancer cells to cytotoxic drugs, and reduce tumor growth and metastatic burden. As such, CXCR4 is a target not only for therapeutic intervention but also for noninvasive monitoring of disease progression and therapeutic guidance. This review provides a comprehensive overview of the biological involvement of CXCR4 in human cancers, the current status of CXCR4-based therapeutic approaches, as well as recent advances in noninvasive imaging of CXCR4 expression.

Chemokines and their receptors play important roles in the development of hepatocellular carcinoma

The chemokine system consists of four different subclasses with over 50 chemokines and 19 receptors. Their functions in the immune system have been well elucidated and research during the last decades unveils their new roles in hepatocellular carcinoma (HCC). The chemokines and their receptors in the microenvironment influence the development of HCC by several aspects including: inflammation, effects on immune cells, angiogenesis, and direct effects on HCC cells. Regarding these aspects, pre-clinical research by targeting the chemokine system has yielded promising data, and these findings bring us new clues in the chemokine-based therapies for HCC.

IL-24 inhibits lung cancer cell migration and invasion by disrupting the SDF-1/CXCR4 signaling axis

Background

The stromal cell derived factor (SDF)-1/chemokine receptor (CXCR)-4 signaling pathway plays a key role in lung cancer metastasis and is molecular target for therapy. In the present study we investigated whether interleukin (IL)-24 can inhibit the SDF-1/CXCR4 axis and suppress lung cancer cell migration and invasion in vitro. Further, the efficacy of IL-24 in combination with CXCR4 antagonists was investigated.

Methods

Human H1299, A549, H460 and HCC827 lung cancer cell lines were used in the present study. The H1299 lung cancer cell line was stably transfected with doxycycline-inducible plasmid expression vector carrying the human IL-24 cDNA and used in the present study to determine the inhibitory effects of IL-24 on SDF-1/CXCR4 axis. H1299 and A549 cell lines were used in transient transfection studies. The inhibitory effects of IL-24 on SDF1/CXCR4 and its downstream targets were analyzed by quantitative RT-PCR, western blot, luciferase reporter assay, flow cytometry and immunocytochemistry. Functional studies included cell migration and invasion assays.

Principal Findings

Endogenous CXCR4 protein expression levels varied among the four human lung cancer cell lines. Doxycycline-induced IL-24 expression in the H1299-IL24 cell line resulted in reduced CXCR4 mRNA and protein expression. IL-24 post-transcriptionally regulated CXCR4 mRNA expression by decreasing the half-life of CXCR4 mRNA (>40%). Functional studies showed IL-24 inhibited tumor cell migration and invasion concomitant with reduction in CXCR4 and its downstream targets (pAKT^S473, pmTOR^S2448, pPRAS40^T246 and HIF-1α). Additionally, IL-24 inhibited tumor cell migration both in the presence and absence of the CXCR4 agonist, SDF-1. Finally, IL-24 when combined with CXCR4 inhibitors (AMD3100, SJA5) or with CXCR4 siRNA demonstrated enhanced inhibitory activity on tumor cell migration.

Conclusions

IL-24 disrupts the SDF-1/CXCR4 signaling pathway and inhibits lung tumor cell migration and invasion. Additionally, IL-24, when combined with CXCR4 inhibitors exhibited enhanced anti-metastatic activity and is an attractive therapeutic strategy for lung metastasis.

The SDF-1/CXCR4 axis induces epithelial–mesenchymal transition in hepatocellular carcinoma

Hepatic stellate cells play a role in the migration process of hepatocellular carcinoma cells. Here, we address the role of the stromal-derived factor-1/CXC chemokine receptor 4 (SDF-1/CXCR4) axis on hepatocellular carcinoma progression. The expression of the SDF-1 and the CXCR4 was determined through western blotting and real-time PCR analysis using hepatic stellate (LX02) and hepatocellular carcinoma (MHCC97, SMMC7721, Hep3B, and HepG2) cell lines depleted of CXCR4 using shRNA. The migration of hepatocellular carcinoma cells following exogenous treatment with SDF-1 or in co-culture cell systems was measured using the Transwell assay. In parallel, the expression of epithelial–mesenchymal transition (EMT) markers was also determined. We found that SDF-1 is highly expressed in the hepatic stellate cell line LX02 and that the hepatocellular carcinoma cells express high levels of CXCR4. Co-culturing hepatocellular carcinoma cells with LX02 or exogenous treatment with SDF-1 induced an EMT as shown by increased migration. In contrast, ablation of CXCR4 expression in HepG2 cells attenuated the migration of HepG2 cells and suppressed the EMT. Thus, hepatic stellate cells can promote hepatocellular carcinoma cell invasion through the SDF-1/CXCR4 axis.

Interfering with CXCR4 expression inhibits proliferation, adhesion and migration of breast cancer MDA-MB-231 cells

To investigate the effect and mechanism of the CXC chemokine receptor 4 (CXCR4) in the proliferation and migration of breast cancer, a short-hairpin RNA (shRNA) eukaryotic expression vector targeting CXCR4 was constructed, and the impact of such on the proliferation, adhesion and migration of human breast cancer MDA-MB-231 cells was observed. The fragments of CXCR4-shRNA were synthesized and cloned into a pGCsi-U6-Neo-green fluorescent protein vector. The recombinant plasmids were transfected into 293T cells and the most efficacious interfering vector was selected. MDA-MB-231 cells were transfected by liposome assay. The effects of silencing CXCR4 expression by shRNA on the growth, adhesion and migration of MDA-MB-231 cells were determined by Cell Counting Kit-8, cell-matrix adhesion and wound-healing assays. The shRNA eukaryotic expression vectors targeting CXCR4 (CXCR4-shRNA) were successfully constructed and transfected into 293T cells. Quantitative polymerase chain reaction and western blot analysis revealed that the maximum inhibitory rate of CXCR4 expression was 81.3%. CXCR4-shRNA transfection significantly inhibited the proliferation of MDA-MB-231 cells (P<0.05), as well as the adhesion between MDA-MB-231 cells and the extracellular matrix (P<0.05). Furthermore, wound-healing assays demonstrated that the migration distance of MDA-MB-231 cells in the CXCR4-shRNA transfection group was significantly smaller than that in the control plasmid and blank control groups (P<0.01). The CXCR4-shRNA interfering vector specifically inhibited CXCR4 expression, as well as the proliferation, adhesion and migration of MDA-MB-231 cells.

A network biology approach to discover the molecular biomarker associated with hepatocellular carcinoma

In recent years, high throughput technologies such as microarray platform have provided a new avenue for hepatocellular carcinoma (HCC) investigation. Traditionally, gene sets enrichment analysis of survival related genes is commonly used to reveal the underlying functional mechanisms. However, this approach usually produces too many candidate genes and cannot discover detailed signaling transduction cascades, which greatly limits their clinical application such as biomarker development. In this study, we have proposed a network biology approach to discover novel biomarkers from multidimensional omics data. This approach effectively combines clinical survival data with topological characteristics of human protein interaction networks and patients expression profiling data. It can produce novel network based biomarkers together with biological understanding of molecular mechanism. We have analyzed eighty HCC expression profiling arrays and identified that extracellular matrix and programmed cell death are the main themes related to HCC progression. Compared with traditional enrichment analysis, this approach can provide concrete and testable hypothesis on functional mechanism. Furthermore, the identified subnetworks can potentially be used as suitable targets for therapeutic intervention in HCC.

The role of chemokines in acute and chronic hepatitis C infection

Hepatitis C imposes a significant burden on global healthcare. Chronic infection is associated with progressive inflammation of the liver which typically manifests in cirrhosis, organ failure and cancer. By virtue of elaborate evasion strategies, hepatitis C virus (HCV) succeeds as a persistent human virus. It has an extraordinary capacity to subvert the immune response enabling it to establish chronic infections and associated liver disease. Chemokines are low molecular weight chemotactic peptides that mediate the recruitment of inflammatory cells into tissues and back into the lymphatics and peripheral blood. Thus, they are central to the temporal and spatial distribution of effector and regulatory immune cells. The interactions between chemokines and their cognate receptors help shape the immune response and therefore, have a major influence on the outcome of infection. However, chemokines represent a target for modulation by viruses including the HCV. HCV is known to modulate chemokine expression in vitro and may therefore enable its survival by subverting the immune response in vivo through altered leukocyte chemotaxis resulting in impaired viral clearance and the establishment of chronic low-grade inflammation. In this review, the roles of chemokines in acute and chronic HCV infection are described with a particular emphasis placed on chemokine modulation as a means of immune subversion. We provide an in depth discussion of the part played by chemokines in mediating hepatic fibrosis while addressing the potential applications for these chemoattractants in prognostic medicine.

G801A polymorphism of human stromal cell-derived factor 1 gene raises no susceptibility to neoplastic lesions of uterine cervix

OBJECTIVE

This study aimed to investigate the association of stromal cell-derived factor 1 (SDF-1) gene polymorphisms with the neoplastic lesions of uterine cervix in Mid-Taiwan women.

MATERIALS AND METHODS

Four hundred ninety-eight blood samples were collected from 161 patients with neoplasia of uterine cervix, including 76 cancer patients, 61 patients with high-grade dysplasia, and 24 with low-grade dysplasia, and 337 healthy controls who lived in Mid-Taiwan. Polymorphism of the SDF-1 gene was examined using polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

For SDF-1 gene polymorphisms, the wild-type homozygous alleles (G/G) yielded 100- and 193-bp products, the heterozygous alleles (G/A) yielded 100-, 193- and 293-bp products, whereas the mutated-type homozygous alleles (A/A) yielded a 293-bp product. We found no significant difference in genotypes or alleles distribution of SDF-1 polymorphisms between patients with cervical neoplasia and healthy women (P = 0.530). Compared with the homozygous GG subgroup, GA and AA subgroups do not increase the risk of cervical neoplasia.

CONCLUSIONS

Although the expression of SDF-1 was reported to be significantly increased in cervical carcinogenesis in previous studies, our results, however, show that SDF-1 gene polymorphism could not be considered as a factor related to an increased susceptibility to cervical neoplasia.

Enhanced tumorigenesis and lymphatic metastasis of CD133+ hepatocarcinoma ascites syngeneic cell lines mediated by JNK signaling pathway in vitro and in vivo

Cancer stem cells (CSCs), stem-like cells, or tumor-initiating cells (TICs) may initiate tumorigenesis and metastasis, but neither the basic cell biology of CSCs nor the mechanisms of CSC-mediated tumor growth and lymphoid node metastasis are understood. Evidence suggests that CSC phenotype is maintained, at least in part, by altered JNK signaling. In this study, factors influencing the growth and metastatic potential of CSCs were examined by comparing CD133 surface antigen expression, proliferation, clonogenicity, invasive capacity, tumorigenicity, and expression of JNK-associated signaling molecules between the highly metastatic mouse hepatocarcinoma ascites syngeneic cell line Hca-F and the low metastasis potential line Hca-P. The Hca-F line exhibited higher clonogenic, proliferative, and invasive capacities than Hca-P cells, and a greater proportion of Hca-F cells were CD133 positive. In both cell lines, the CD133+ subpopulation showed significantly enhanced tumorigenicity and metastatic potential. An in vivo tumorigenicity assay in nude mice indicated that Hca-F cells possessed significantly higher tumorigenicity than Hca-P cells as indicated by larger tumors after inoculation. Expression levels of E-cadherin (CDH1), annexin VII, and JNK1 proteins were inversely correlated with CD133 expression in both Hca-F and Hca-P cells. These results demonstrate that CD133+ subpopulations of both Hca-F and Hca-P lines show CSC-like properties. However, Hca-F cells showed greater tumorigenicity and invasiveness, consistent with greater lymphatic metastasis capacity. We propose that tumorigenesis and lymphatic metastasis are regulated by JNK/P53/annexin VII and JNK/ATF-2/CDH1/annexin VII signal transduction pathways.

The inflammatory microenvironment in hepatocellular carcinoma: a pivotal role for tumor-associated macrophages

Hepatocellular carcinoma (HCC) is one of the most common and aggressive human cancers worldwide. HCC is an example of inflammation-related cancer and represents a paradigm of the relation occurring between tumor microenvironment and tumor development. Tumor-associated macrophages (TAMs) are a major component of leukocyte infiltrate of tumors and play a pivotal role in tumor progression of inflammation-related cancer, including HCC. Several studies indicate that, in the tumor microenvironment, TAMs acquire an M2-polarized phenotype and promote angiogenesis, metastasis, and suppression of adaptive immunity through the expression of cytokines, chemokines, growth factors, and matrix metalloproteases. Indeed, an established M2 macrophage population has been associated with poor prognosis in HCC. The molecular links that connect cancer cells and TAMs are not completely known, but recent studies have demonstrated that NF-κB, STAT-3, and HIF-1 signaling pathways play key roles in this crosstalk. In this paper, we discuss the current knowledge about the role of TAMs in HCC development, highlighting the role of TAM-derived cytokines, chemokines, and growth factors in the initiation and progression of liver cancer and outlining the signaling pathways involved in the interplay between cancer cells and TAMs.

GRP78 and GAL3, differentially regulated by lymph node homogenates, as potential biomarkers for lymph node metastasis in mouse hepatocellular carcinoma cells

In order to systematically evaluate the influence of lymph nodes (LNs) in lymph node metastases (LNM) of hepatocellular carcinoma (HCC), we set up a new in vitro model in which Hca-F and Hca-P cells were cultured in medium containing lymph node homogenates (LNHs). Differential protein expression was measured by two-dimensional gel electrophoresis (2-DE) combined with matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI TOF/TOF MS). Results from protein identification revealed two metastatic correlative proteins, 78-kDa glucose-regulated protein (GRP78) and galectin-3 (GAL3). Western blotting confirmed that GRP78, a protein positively correlated with metastasis, increased 2.4-fold in Hca-F cells but decreased to almost a half in Hca-P cells (P<0.05). However, GAL3, a protein negatively correlated with metastasis, was decreased by a half in Hca-F cells but slightly increased non-significantly in Hca-P cells. Thus, our results reveal that some components of LNHs may facilitate a permissive environment for cancer cells with high metastasis potential to eventually metastasize. GRP78 and GAL3 may serve as potential biomarkers for the diagnosis of LNM in HCC.

Capturing circulating tumor cells of hepatocellular carcinoma

Early metastases of hepatocellular carcinoma (HCC) may be detected by the isolation of circulating tumor cells (CTCs) in the bloodstream. During the course of therapeutic attempts, monitoring CTC changes in patients with HCC is helpful for the efficacy assessment. Nevertheless, the markers used for the detection, such as α-feto protein, asialoglycoprotein receptor or epithelial cell adhesion molecule, CD133 or CD90, are not specific for HCC CTCs. In spite of these limitations, a timely determination of the existence of CTCs will be beneficial for the monitoring of distant metastases, the evaluation of therapeutic attempts, and the prediction of prognosis.

Curcumin inhibits the migration and invasion of mouse hepatoma Hca-F cells through down-regulating caveolin-1 expression and epidermal growth factor receptor signaling

Mouse hepatoma cellular carinoma cell line (Hca-F) cells have highly invasive and lymphatic metastasis potential in vitro and in vivo. Curcumin (diferuloylmethane) is an active component of the spice turmeric and has a diversity of antitumor activities. However, there is no available information to address the effects of curcumin on migration and invasion of mouse hepatoma Hca-F cells. In this study, we found that curcumin exerted a concentration- and time-dependent inhibitory effect on the migration and invasion of Hca-F cells in vitro. Curcumin inhibited the expression of the tumor promoter caveolin-1 (Cav-1) in Hca-F cells. Up-regulation of Cav-1 expression by pcDNA3.1/Cav-1 plasmid was able to reverse the curcumin-induced antimigration and anti-invasion effects in vitro. Curcumin down-regulated the expression of cluster of differntiation (CD)147, matrix metalloproteinase 2, and matrix metalloproteinase 9 and inhibited the phosphorylation of epidermal growth factor receptor (EGFR), the phosphoinositilde 3-kinase (PI3K)/protein kinase B (Akt), p38 mitogen-activated protein kinase (MAPK), and p44/42MAPK in Hca-F cells. Taken together, our findings suggest that curcumin can suppress the migratory and invasive ability of mouse hepatoma Hca-F cells, and this action is mediated through a novel mechanism involving inactivation of Cav-1 and EGFR signaling pathways.

Chemokines and hepatocellular carcinoma

Chemokines play a paramount role in tumor progression. In hepatocellular carcinoma (HCC) progression, chemokines and their receptors play an intricate role. Currently, chemokines and their receptors such as the CXCL12-CXCR4 axis, CX3CL1-CX3CR1 axis and the CCL20-CCR6 axis have received much research attention. Although a large number of studies show that these axes are strongly associated with HCC, the exact mechanism by which these axes promote the growth and progression of HCC remains unknown. In this paper, several chemokines and their receptor interactions in HCC progression, growth and metastasis and immune response to HCC are reviewed.

High expression of osteoglycin decreases gelatinase activity of murine hepatocarcinoma Hca-F cells

AIM: To investigate the possible correlation between osteoglycin expression and gelatinase activity of mouse hepatocarcinoma Hca-F cells.

METHODS: A eukaryotic expression plasmid pIRESpuro3 osteoglycin(+) was constructed and transfected into Hca-F cells to investigate the possible correlation between osteoglycin expression and gelatinase activity of Hca-F cells cultured with extract of lymph node, liver, spleen or in DMEM medium. The activity of gelatinases was examined through zymographic analysis.

RESULTS: High expression of osteoglycin attenuated the gelatinase activity of Hca-F cells cultured with extract of lymph node, and at the same time, decreased the metastatic potential of Hca-F cells to peripheral lymph nodes in vivo.

CONCLUSION: High expression of osteoglycin decreases the gelatinase activity of Hca-F cells cultured with extract of lymph node; regulation of gelatinase activity might be one of mechanisms that osteoglycin contributes to lymphatic metastasis suppression.

Stromal cell-derived factor-1 but not its receptor, CXCR4, gene variants increase susceptibility and pathological development of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most frequent malignant neoplasms worldwide. Genetic polymorphism has been reported as a predictive factor related to a higher risk for HCC. Because the stromal cell-derived factor-1 (SDF-1) and its receptor, CXCR4, have been reported to play important roles in tumor cell proliferation, angiogenesis, and metastasis of HCC, the aim of this study was to estimate the relationship between SDF-1 and CXCR4 gene variants to HCC risk and clinicopathological status.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism was used to measure SDF-1 (rs1801157) and CXCR4 (rs2228014) gene polymorphisms in 311 healthy controls and 102 patients with HCC.

RESULTS

Compared to controls, individuals with at least one A allele had a higher risk of 1.57-fold (95% CI: 1.00-2.47) to induce HCC and had a risk of 2.81-fold (95% CI: 1.04-7.58) to develop a status of stage III or stage IV disease, after being adjusted for other confounders. However, there was no significant association between CXCR4 gene polymorphism and either HCC risk or pathological status. Additionally, both gene polymorphisms were not associated with the serum expression of liver-related clinical pathological markers.

CONCLUSIONS

SDF-1-3'A gene polymorphism could be considered as a factor related to an increased susceptibility to the risk and pathological development of HCC.

Cytoplasmic trapping of CXCR4 in hepatocellular carcinoma cell lines

PURPOSE

The chemokine receptor CXCR4 plays a role in the metastasis and progression of a broad range of malignant tumors; however, its influence on hepatocellular carcinoma (HCC) is not well defined. Thus, we analyzed the expression of CXCR4 and its functions in HCC cell lines in vitro.

MATERIALS AND METHODS

Five HCC cell lines (HepG2, Hep3B, SK-HEP-1, NCI-H630 and PLC/PRF5) were investigated. The CXCR4 expression was analyzed by RT-PCR, Western blotting, flow cytometry and immunofluorescence staining. In addition, the effects of stromal cell-derived factor-1 (SDF-1) on the migration, proliferation and survival of the cells were investigated, as well as the SDF-1-induced phosphorylation of signaling molecules.

RESULTS

All five cell lines had abundant CXCR4 in their cytoplasm, whereas a cell surface CXCR4 expression was only detected in a very small population of PLC/PRF5 cells. In contrast, SDF-1 bound to all the cells. SDF-1 induced the phosphorylation of AKT and ERK1/2 in the PLC/PRF5 cells and the phosphorylation of Stat3, AKT and ERK1/2 in the Hep3B cells. Nonetheless, SDF-1 did not induce migration or proliferation in any of the cells, nor did it rescue the cells from serum deprivation-induced apoptosis. Recruitment of CXCR4 from the cytoplasm to the cell surface was not elicited by dexamethasone, proinflammatory cytokines or VEGF. Hypoxia increased both the cytoplasmic and cell surface expressions of CXCR4 in only the PLC/PRF5 cells.

CONCLUSIONS

CXCR4 is trapped in the cytoplasm and it is not recruited to the cell surface by standard extrinsic stimuli in the majority of HCC cell lines, and the result of this is a negligible response to SDF-1.

CXCL12/CXCR4 transactivates HER2 in lipid rafts of prostate cancer cells and promotes growth of metastatic deposits in bone

Chemokines and their receptors function in migration and homing of cells to target tissues. Recent evidence suggests that cancer cells use a chemokine receptor axis for metastasis formation at secondary sites. Previously, we showed that binding of the chemokine CXCL12 to its receptor CXCR4 mediated signaling events resulting in matrix metalloproteinase-9 expression in prostate cancer bone metastasis. A variety of methods, including lipid raft isolation, stable overexpression of CXCR4, cellular adhesion, invasion assays, and the severe combined immunodeficient-human bone tumor growth model were used. We found that (a) CXCR4 and HER2 coexist in lipid rafts of prostate cancer cells; (b) the CXCL12/CXCR4 axis results in transactivation of the HER2 receptor in lipid rafts of prostate cancer cells; (c) Src kinase mediates CXCL12/CXCR4 transactivation of HER2 in prostate cancer cells; (d) a pan-HER inhibitor desensitizes CXCR4-induced transactivation and subsequent matrix metalloproteinase-9 secretion and invasion; (e) lipid raft-disrupting agents inhibited raft-associated CXCL12/CXCR4 transactivation of the HER2 and cellular invasion; (f) overexpression of CXCR4 in prostate cancer cells leads to increased HER2 phosphorylation and migratory properties of prostate cancer cells; and (g) CXCR4 overexpression enhances bone tumor growth and osteolysis. These data suggest that lipid rafts on the cell membrane are the key site for CXCL12/CXCR4-induced HER2 receptor transactivation. This transactivation contributes to enhanced invasive signals and metastatic growth in the bone microenvironment.

High expression of osteoglycin decreases the metastatic capability of mouse hepatocarcinoma Hca-F cells to lymph nodes

Osteoglycin, one of the matrix molecules, belongs to the small leucine-rich proteoglycan gene family and might play important roles in cell growth and differentiation and in pathological processes such as fibrosis and cancer growth. In this study, a eukaryotic expression plasmid pIRESpuro3 osteoglycin(+) was constructed and transfected into mouse hepatocarcinoma Hca-F cells to evaluate the contribution of osteoglycin to the malignant behavior of Hca-F. It was found that Hca-F cells transfected with pIRESpuro3 osteoglycin(+) showed significantly decreased potential for both migration and invasion. Furthermore, Hca-F cells transfected with osteoglycin showed decreased metastatic potential to peripheral lymph nodes. However, proliferation potential and adhesive capacity of Hca-F cells to different protein substrates were not influenced by osteoglycin transfection. In summary, high expression of osteoglycin decreases the metastatic capability of Hca-F to lymph nodes.

Tissue inhibitor of metalloproteinase-3 via oncolytic herpesvirus inhibits tumor growth and vascular progenitors

Malignant solid tumors remain a significant clinical challenge, necessitating innovative therapeutic approaches. Oncolytic viral therapy is a nonmutagenic, biological anticancer therapeutic shown to be effective against human cancer in early studies. Because matrix metalloproteinases (MMP) play important roles in the pathogenesis and progression of cancer, we sought to determine if "arming" an oncolytic herpes simplex virus (oHSV) with an MMP-antagonizing transgene would increase virus-mediated antitumor efficacy. We generated oHSVs that express human tissue inhibitor of metalloproteinases 3 (TIMP3) or firefly luciferase and designated them rQT3 and rQLuc, respectively. We evaluated the antitumor efficacy of these viruses against neuroblastoma and malignant peripheral nerve sheath tumor (MPNST) xenografts. Relative to rQLuc, rQT3-infected primary human MPNST and neuroblastoma cells exhibited equivalent virus replication but increased cytotoxicity and reduced MMP activity. In vivo, rQT3-treated tumors showed delayed tumor growth, increased peak levels of infectious virus, immature collagen extracellular matrix, and reduced tumor vascular density. Remarkably, rQT3 treatment reduced circulating endothelial progenitors, suggesting virus-mediated antivasculogenesis. We conclude that rQT3 enhanced antitumor efficacy through multiple mechanisms, including direct cytotoxicity, elevated virus titer, and reduced tumor neovascularization. These findings support the further development of combined TIMP-3 and oncolytic virotherapy for cancer.

Nitric oxide donor upregulation of stromal cell-derived factor-1/chemokine (CXC motif) receptor 4 enhances bone marrow stromal cell migration into ischemic brain after stroke

Stromal cell-derived factor-1 (SDF1) and its chemokine (CXC motif) receptor 4 (CXCR4), along with matrix metalloproteinases (MMPs), regulate bone marrow stromal cell (BMSC) migration. We tested the hypothesis that a nitric oxide donor, DETA-NONOate, increases endogenous ischemic brain SDF1 and BMSC CXCR4 and MMP9 expression, which promotes BMSC migration into ischemic brain and thereby enhances functional outcome after stroke. C57BL/6J mice were subjected to middle cerebral artery occlusion (MCAo), and 24 hours later, the following were intravenously administered (n = 9 mice per group): (a) phosphate-buffered saline; (b) BMSCs (5 x 10(5)); (c) 0.4 mg/kg DETA-NONOate; (d) combination of CXCR4-inhibition BMSCs with DETA-NONOate; and (e) combination of BMSCs with DETA-NONOate. To elucidate the mechanisms underlying combination-enhanced BMSC migration, transwell cocultures of BMSC with mouse brain endothelial cells (MBECs) or astrocytes were performed. Combination treatment significantly improved functional outcome after stroke compared with BMSC monotherapy and MCAo control, and it increased SDF1 expression in the ischemic brain compared with DETA-NONOate monotherapy and MCAo control. The number of BMSCs in the ischemic brain was significantly increased after combination BMSC with DETA-NONOate treatment compared with monotherapy with BMSCs. The number of engrafted BMSCs was significantly correlated with functional outcome after stroke. DETA-NONOate significantly increased BMSC CXCR4 and MMP9 expression and promoted BMSC adhesion and migration to MBECs and astrocytes compared with nontreatment BMSCs. Inhibition of CXCR4 or MMPs in BMSCs significantly decreased DETA-NONOate-induced BMSC adhesion and migration. Our data demonstrate that DETA-NONOate enhanced the therapeutic potency of BMSCs, possibly via upregulation of SDF1/CXCR4 and MMP pathways, and increased BMSC engraftment into the ischemic brain.

Dynamic stromal-epithelial interactions during progression of MCF10DCIS.com xenografts

MCF10DCIS.com cells form comedo type ductal carcinoma in situ in immune-deficient mice before forming invasive ductal carcinoma. As the lesions mature, both stromal and epithelial cells undergo phenotypic changes detected by immunohistochemistry. Myofibroblasts are present before the formation of carcinoma in situ and after development of invasive carcinoma. MCF10DCIS. com lesions develop a myoepithelial layer prior to exhibiting a basement membrane surrounding the ductal mass. TGFbeta1 is initially expressed by the epithelial cells but is expressed by stroma in invasive carcinoma. Stromal derived factor-1 is detected in epithelial cells in early carcinoma in situ but is produced in stromal cells in invasive carcinoma. The receptor CXCR4 is expressed by epithelial cells in the xenografts at all times, as is the hepatocyte growth factor receptor c-met. MCF10DCIS.com xenografts illustrate the dynamic interplay of epithelium and stroma in the development of carcinoma in situ and subsequent invasive carcinoma. Although the phenotype of the epithelial cells may be dependent upon the stroma, the malignant epithelium induces the development of the stroma necessary for progression to the invasive stage. (c) 2007 Wiley-Liss, Inc.