Regulation of the metastatic process by E-selectin and stress-activated protein kinase-2/p38

Probing expression of E-selectin using CRISPR-Cas9-mediated tagging with HiBiT in human endothelial cells

E-selectin is expressed on endothelial cells in response to inflammatory cytokines and mediates leukocyte rolling and extravasation. However, studies have been hampered by lack of experimental approaches to monitor expression in real time in living cells. Here, NanoLuc Binary Technology (NanoBiT) in conjunction with CRISPR-Cas9 genome editing was used to tag endogenous E-selectin in human umbilical vein endothelial cells (HUVECs) with the 11 amino acid nanoluciferase fragment HiBiT. Addition of the membrane-impermeable complementary fragment LgBiT allowed detection of cell surface expression. This allowed the effect of inflammatory mediators on E-selectin expression to be monitored in real time in living endothelial cells. NanoBiT combined with CRISPR-Cas9 gene editing allows sensitive monitoring of real-time changes in cell surface expression of E-selectin and offers a powerful tool for future drug discovery efforts aimed at this important inflammatory protein.

Prognostic and Therapeutic Role of CD15 and CD15s in Cancer

Simple Summary

CD15 (Lewis X) is a typical myeloid antigen presented in myeloid and monocytic lineages of cells. This molecule interacts with E-, L- and P-selectins, which allows for adhesion with endothelial cells. CD15 is found on various cancer cells, including renal cancer, prostate and bladder cancers, acute leukaemias, hepatocellular carcinoma, breast cancer and melanoma cells. Its high expression can serve as a prognostic marker for patients and is a potentially valuable target for immunotherapy against cancer. Blockage of the antigen’s function results in reduced metastatic potential and it may be an immunotherapeutic target. CD15s is a sialyl derivative of CD15; however, unlike the high expression of CD15, which is a prognostic factor in Hodgkin lymphoma, CD15s relates to poor prognosis for patients. CD15 is considered a marker of cancer stem cells. This review presents a comprehensive description of the prognostic role of CD15 and CD15s and their use in anticancer therapy.

Abstract

CD15 (Lewis X/Lex) is a fucosyl (3-fucosly-N-acetyl-lactosamine) moiety found on membrane proteins of various cancer cells. These cancers include renal cancer, prostate and bladder cancers, acute leukaemias, hepatocellular carcinoma, breast cancer and melanoma. The biological role of CD15 is interaction with E-, L- and P-selectins (adhesion molecules), allowing for adhesion with endothelial cells. In this way, cancer cells start to interact with the endothelia of blood vessels and consequently move out from the blood flow to the surrounding tissues. Blockage of the antigen’s function results in reduced metastatic potential. Moreover, the molecule may be a therapeutic target against cancer in monoclonal antibody-based therapies. CD15 may serve as a prognostic marker for patients and there are high hopes for its use in the immunotherapeutic treatment of tumours. CD15s is a sialyl derivative of CD15 that possesses its own unique characteristics. Its soluble form may act as a competitive inhibitor of the interaction of cancer cells with epithelial cells and thus disallow migration through the vessels. However, the prognostic relevance of CD15 and CD15s expression is very complex. This review presents a comprehensive description of the role of CD15 and CD15s in cancer development and metastasis and overviews its significance for clinical applications.

Co-Expression and Functional Interactions of Death Receptor 3 and E-Selectin in Clear Cell Renal Cell Carcinoma

Similar to the behavior of inflamed tubular epithelial cells, clear cell renal cell carcinoma (ccRCC) cells express death receptor 3 (DR3 or TNFSFR25) in situ, and expression increases with tumor grade. Surprisingly, E-selectin, which can be induced in endothelial cells by DR3 signaling, is also expressed by ccRCC cells and increases with tumor grade. In ccRCC organ cultures, addition of tumor necrosis factor-like 1A (TL1A or TNFSF15), the ligand for DR3, activates NF-κB and mitogen-activated protein kinases, induces both DR3 and E-selectin expression in an NF-κB-dependent manner, and promotes cell cycle entry. DR3 immunoprecipitated from ccRCC tissue contains sialyl Lewis X moieties (the ligand recognized by E-selectin), proximity ligation assays reveal DR3, and E-selectin interacts on ccRCC cells. Similar to that with the addition of TL1A, the addition of soluble E-selectin to ccRCC organ cultures activates NF-κB and mitogen-activated protein kinases in ccRCC cells and increases both DR3 and E-selectin expression and cell-cycle entry. In contrast, normal renal tubular epithelium, which poorly expresses DR3, is minimally responsive to either of these ligands. These data suggest a functional role for autocrine/paracrine DR3/E-selectin interactions in ccRCC and its progression, revealing a potential new target for therapeutic intervention.

ESDN inhibits melanoma progression by blocking E-selectin expression in endothelial cells via STAT3

An interactive crosstalk between tumor and stroma cells is essential for metastatic melanoma progression. We evidenced that ESDN/DCBLD2/CLCP1 plays a crucial role in endothelial cells during the spread of melanoma. Precisely, increased extravasation and metastasis formation were revealed in ESDN-null mice injected with melanoma cells, even if the primary tumor growth, vessel permeability, and angiogenesis were not enhanced. Interestingly, improved adhesion of melanoma cells to ESDN-depleted endothelial cells was observed, due to the presence of higher levels of E-selectin transcripts/proteins in ESDN-defective cells. In accordance with these results, anticorrelation was observed between ESDN and E-selectin in human endothelial cells. Most importantly, our data revealed that cimetidine, an E-selectin inhibitor, was able to block cell adhesion, extravasation, and metastasis formation in ESDN-null mice, underlying a major role of ESDN in E-selectin transcription upregulation, which according to our data, may presumably be linked to STAT3. Based on our results, we propose a protective role for ESDN during the spread of melanoma and reveal its therapeutic potential.

Microwave Responsive Nanoplatform via P-Selectin Mediated Drug Delivery for Treatment of Hepatocellular Carcinoma with Distant Metastasis

Hepatocellular carcinoma (HCC) with metastatic disease is associated with a low survival in clinical practice. Many curative options including liver resection, transplantation, and thermal ablation are effective in local but limited for patients with distant metastasis. In this study, the efficacy, specificity, and safety of P-selectin targeted delivery and microwave (MW) responsive drug release is investigated for development of HCC therapy. By encapsulating doxorubicin (DOX) and MW sensitizer (1-butyl-3-methylimidazolium-l-lactate, BML) into fucoidan conjugated liposomal nanoparticles (TBP@DOX), specific accumulation and prominent release of DOX in orthotopic HCC and lung metastasis are achieved with adjuvant MW exposure. This results in orthotopic HCC growth inhibition that is not only 1.95-fold higher than found for nontargeted BP@DOX and 1.6-fold higher than nonstimuli responsive TP@DOX but is also equivalent to treatment with free DOX at a 10-fold higher dose. Furthermore, the optimum anticancer efficacy against distant lung metastasis and effective prevention of widespread dissemination with a prolonged survival is described. In addition, no adverse metabolic events are identified using the TBP@DOX nanodelivery system despite these events being commonly observed with traditional DOX chemotherapy. Therefore, administering TBP@DOX with MW exposure could potentially enhance the therapeutic efficacy of thermal-chemotherapy of HCC, especially those in the advanced stages.

Quinic Acid-Conjugated Nanoparticles Enhance Drug Delivery to Solid Tumors via Interactions with Endothelial Selectins

Current nanoparticle (NP) drug carriers mostly depend on the enhanced permeability and retention (EPR) effect for selective drug delivery to solid tumors. However, in the absence of a persistent EPR effect, the peritumoral endothelium can function as an access barrier to tumors and negatively affect the effectiveness of NPs. In recognition of the peritumoral endothelium as a potential barrier in drug delivery to tumors, poly(lactic-co-glycolic acid) (PLGA) NPs are modified with a quinic acid (QA) derivative, synthetic mimic of selectin ligands. QA-decorated NPs (QA-NP) interact with human umbilical vein endothelial cells expressing E-/P-selectins and induce transient increase in endothelial permeability to translocate across the layer. QA-NP reach selectin-upregulated tumors, achieving greater tumor accumulation and paclitaxel (PTX) delivery than polyethylene glycol-decorated NPs (PEG-NP). PTX-loaded QA-NP show greater anticancer efficacy than Taxol or PTX-loaded PEG-NP at the equivalent PTX dose in different animal models and dosing regimens. Repeated dosing of PTX-loaded QA-NP for two weeks results in complete tumor remission in 40-60% of MDA-MB-231 tumor-bearing mice, while those receiving control treatments succumb to death. QA-NP can exploit the interaction with selectin-expressing peritumoral endothelium and deliver anticancer drugs to tumors to a greater extent than the level currently possible with the EPR effect.

DNA Thioaptamer with Homing Specificity to Lymphoma Bone Marrow Involvement

Selective drug accumulation in the malignant tissue is a prerequisite for effective cancer treatment. However, most drug molecules and their formulated particles are blocked en route to the destiny tissue due to the existence of multiple biological and physical barriers including the tumor microvessel endothelium. Since the endothelial cells on the surface of the microvessel wall can be modulated by inflammatory cytokines and chemokines secreted by the tumor or stromal cells, an effective drug delivery approach is to enhance interaction between the drug particles and the unique spectrum of surface proteins on the tumor endothelium. In this study, we performed in vivo screening for thioaptamers that bind to the bone marrow endothelium with specificity in a murine model of lymphoma with bone marrow involvement (BMI). The R1 thioaptamer was isolated based on its high homing potency to bones with BMI, and 40-60% less efficiency in accumulation to healthy bones. In cell culture, R1 binds to human umbilical vein endothelial cells (HUVEC) with a high affinity ( Kd ≈ 3 nM), and the binding affinity can be further enhanced when cells were treated with a mixture of lymphoma cell and bone marrow cell conditioned media. Cellular uptake of R1 is through clathrin-mediated endocytosis. Conjugating R1 on to the surface of liposomal doxorubicin nanoparticles resulted in 2-3-fold increase in drug accumulation in lymphoma BMI. Taking together, we have successfully identified a thioaptamer that preferentially binds to the endothelium of lymphoma BMI. It can serve as an affinity moiety for targeted delivery of drug particles to the disease organ.

p38 and JNK pathways control E-selectin-dependent extravasation of colon cancer cells by modulating miR-31 transcription

Extravasation of circulating cancer cells is a key event of metastatic dissemination that is initiated by the adhesion of cancer cells to vascular endothelial cells. It requires the interaction between adhesion receptors such as E-selectin present on endothelial cells and their ligands on cancer cells. Notably, E-selectin influences the metastatic potential of breast, bladder, gastric, pancreatic, and colorectal carcinoma as well as of leukemia and lymphoma. Here, we show that E-selectin expression induced by the pro-inflammatory cytokine IL-1β is directly and negatively regulated by miR-31. The transcription of miR-31 is activated by IL-1β. This activation depends on p38 and JNK MAP kinases, and their downstream transcription factors GATA2, c-Fos and c-Jun. The miR-31-mediated repression of E-selectin impairs the metastatic potential of colon cancer cells by decreasing their adhesion to, and migration through, the endothelium. These results highlight for the first time that microRNA mediates E-selectin-dependent extravasation of colon cancer cells.

Significance of TNF-α and the Adhesion Molecules: L-Selectin and VCAM-1 in Papillary Thyroid Carcinoma

Circulating levels of TNF-α and the adhesion molecules L-Selectin and VCAM-1 as well as their expression in the primary tumors of patients with benign thyroid diseases and papillary thyroid carcinoma (PTC) have been determined in this study. The serum levels of TNF-α, L-Selectin, and VCAM-1 were significantly higher in patients with both benign thyroid diseases and PTC as compared to the healthy individuals. However, the levels of only TNF-α and L-Selectin, and not VCAM-1, were significantly higher in patients with PTC in comparison to those observed in patients with benign thyroid diseases. Further the expression of TNF-α and L-Selectin was also significantly higher in the primary tumors of PTC patients, relative to the benign thyroid diseases. The expression of L-Selectin and VCAM-1 significantly correlated with aggressive tumor behavior. In PTC patients, the circulating TNF-α levels significantly positively correlated with the levels of L-Selectin, while TNF-α immunoreactivity was significantly associated with VCAM-1 expression. Serum TNF-α was found to be a significant prognosticator for OS in PTC patients. Overall the results signify that the interaction between TNF-α and the adhesion molecules may have a role in thyroid carcinogenesis and understanding this complexity may offer potential therapeutic targets for better management of thyroid cancer.

P-selectin enhances growth and metastasis of mouse mammary tumors by promoting regulatory T cell infiltration into the tumors

AIMS

P-selectin is an adhesion receptor that is mainly present on endothelial cells and platelets. We investigated the role of P-selectin in the regulation of different T cell subsets in the tumor microenvironment, and how that influences the growth and metastasis of mouse mammary cancer cell line 4T1 in Balb/c mice.

MAIN METHODS

The 4T1 cells (1×10(4) or 1×10(5)) were inoculated subcutaneously in the pre-shaved back skin of the P-selectin knockout (P-sel-/-) and wild-type (WT) mice. Mice were monitored twice weekly for the tumor growth measurements and survival studies. The tumors and the lungs were isolated for cytokine and T cell subset analyses at the end of the study.

KEY FINDINGS

Mice lacking P-selectin had reduced tumor burden, higher survival and reduced metastasis compared to WT mice. Loss of P-selectin inhibited the infiltration of regulatory T cells and reduced pro-inflammatory cytokines, such as IL-4, IL-10, and TGFβ in the tumors. Furthermore, the CD8+ T cells and effector CD4+ T cells were functional and exhibited enhanced infiltration into the tumors of P-selectin knockout mice compared to WT mice.

SIGNIFICANCE

These results demonstrated that P-selectin is an important adhesion molecule vital for infiltration of regulatory T cells into the tumors. Thus, inhibiting P-selectin can have important therapeutic implications against breast cancer growth and metastasis.

Bone marrow endothelium-targeted therapeutics for metastatic breast cancer

Effective treatment of cancer metastasis to the bone relies on bone marrow drug accumulation. The surface proteins in the bone marrow vascular endothelium provide docking sites for targeted drug delivery. We have developed a thioaptamer that specifically binds to E-selectin that is overexpressed in the vasculature of tumor and inflammatory tissues. In this study, we tested targeted delivery of therapeutic siRNA loaded in the E-selectin thioaptamer-conjugated multistage vector (ESTA-MSV) drug carrier to bone marrow for the treatment of breast cancer bone metastasis. We evaluated tumor type- and tumor growth stage-dependent targeting in mice bearing metastatic breast cancer in the bone, and carried out studies to identify factors that determine targeting efficiency. In a subsequent study, we delivered siRNA to knock down expression of the human STAT3 gene in murine xenograft models of human MDA-MB-231 breast tumor, and assessed therapeutic efficacy. Our studies revealed that the CD31(+)E-selectin(+) population accounted for 20.8%, 26.4% and 29.9% of total endothelial cells respectively inside the femur of mice bearing early, middle and late stage metastatic MDA-MB-231 tumors. In comparison, the double positive cells remained at a basal level in mice with early stage MCF-7 tumors, and jumped to 23.9% and 28.2% when tumor growth progressed to middle and late stages. Accumulation of ESTA-MSV inside the bone marrow correlated with the E-selectin expression pattern. There was up to 5-fold enrichment of the targeted MSV in the bone marrow of mice bearing early or late stage MDA-MB-231 tumors and of mice with late stage, but not early stage, MCF-7 tumors. Targeted delivery of STAT3 siRNA in ESTA-MSV resulted in knockdown of STAT3 expression in 48.7% of cancer cells inside the bone marrow. Weekly systemic administration of ESTA-MSV/STAT3 siRNA significantly extended survival of mice with MDA-MB-231 bone metastasis. In conclusion, targeting the overexpressed E-selectin provides an effective approach for tissue-specific drug delivery to the bone marrow. Tumor growth in the bone can be effectively inhibited by blockage of the STAT3 signaling.

Polymorphic variant Ser128Arg of E-Selectin is associated with breast cancer risk and high grade tumors

BACKGROUND

The present study aimed to evaluate the association between the E-Selectin Ser128Arg polymorphism and breast cancer risk and clinicopathological characteristics of the patients.

MATERIALS AND METHODS

The genotypes of 387 breast cancer patients and 252 healthy women who had no history of any malignancy were detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in a hospital-based Malaysian population.

RESULTS

The frequency of the Arg allele was significantly (p = 0.030) higher in breast cancer patients than in healthy individuals. Women who were Ser/Arg heterozygotes (adjusted odds ratio (OR(adj)) = 1.607; 95% confidence interval (CI) = 1.008-2.564), and carriers of the Arg allele genotype (OR(adj) = 1.587; 95% CI = 1.037-2.430) or Arg allele (OR(adj) = 1.509; 95% CI = 1.040-2.189) showed a significantly increased risk of breast cancer. Patients who were carriers of the Arg allele genotype showed a significant association with poorly differentiated tumors (p = 0.002).

CONCLUSION

The Ser128Arg polymorphism might confer an increased susceptibility to breast cancer and contribute to aggressive phenotypic characteristics.

Regulation of sialyl Lewis antigen expression in colon cancer cells by sialidase NEU4

Sialyl Lewis antigens, sialyl Lewis a and sialyl Lewis x, are utilized as tumor markers, and their increase in cancer is associated with tumor progression by enhancement of cancer cell adhesion to endothelial E-selectin. However, regulation mechanisms are not fully understood. We previously demonstrated that NEU4 is the only sialidase efficiently acting on mucins and it is down-regulated in colon cancer. To elucidate the significance of NEU4 down-regulation, we investigated sialyl Lewis antigens as endogenous substrates for the sialidase. NEU4 was found to hydrolyze the antigens in vitro and decrease cell surface levels much more effectively than other sialidases. Western blot, thin layer chromatography, and metabolic inhibition studies of desialylation products revealed NEU4 to preferentially catalyze sialyl Lewis antigens expressed on O-glycans. Cell adhesion to and motility and growth on E-selectin were significantly reduced by NEU4. E-selectin stimulation of colon cancer cells enhanced cell motility through activation of the p38/Hsp27/actin reorganization pathway, whereas NEU4 attenuated the signaling. On immunocytochemical analysis, some NEU4 molecules were localized at cell surfaces. Under hypoxia conditions whereby the antigens were increased concomitantly with several sialyl- and fucosyltransferases, NEU4 expression was markedly decreased. These results suggest that NEU4 plays an important role in control of sialyl Lewis antigen expression and its impairment in colon cancer.

Aberrant expression and function of death receptor-3 and death decoy receptor-3 in human cancer

Death receptor-3 (DR3) and death decoy receptor-3 (DcR3) are both members of the tumour necrosis factor receptor (TNFR) superfamily. The TNFR superfamily contains eight death domain-containing receptors, including TNFR1 (also called DR1), Fas (also called DR2), DR3, DR4, DR5, DR6, NGFR and EDAR. Upon the binding of these receptors with their corresponding ligands, the death domain recruits various proteins that mediate both the death and proliferation of cells. Receptor function is negatively regulated by decoy receptors (DcR1, DcR2, DcR3 and OPG). DR3/DcR3 are a pair of positive and negative players with which vascular endothelial growth inhibitor (VEGI) interacts. VEGI has been suggested to be a potential tumour suppressor. The inhibitory effects of VEGI on cancer are manifested in three main areas: a direct effect on cancer cells, an anti-angiogenic effect on endothelial cells, and the stimulation of dendritic cell maturation. A recent study indicated that DR3 may be a new receptor for E-selectin, which has been reported to be associated with cancer metastasis. DcR3 is a soluble receptor, highly expressed in various tumours, which lacks an apparent transmembrane segment, prevents cytokine response through ligand binding and neutralization, and is an inhibitor of apoptosis. DcR3 serves as a decoy receptor for FasL, LIGHT and VEGI. The cytokine LIGHT activates various anti-tumour functions and is expected to be a promising candidate for cancer therapy. Certain tumours may escape FasL-dependent immune-cytotoxic attack by expressing DcR3, which blocks FasL function. DR3/DcR3 play profound roles in regulating cell death and proliferation in cancer. The present review briefly discusses DR3/DcR3 and attempts to elucidate the role of these negative and positive players in cancer.

Endothelial-Rac1 is not required for tumor angiogenesis unless alphavbeta3-integrin is absent

Endothelial cell migration is an essential aspect of tumor angiogenesis. Rac1 activity is needed for cell migration in vitro implying a requirement for this molecule in angiogenesis in vivo. However, a precise role for Rac1 in tumor angiogenesis has never been addressed. Here we show that depletion of endothelial Rac1 expression in adult mice, unexpectedly, has no effect on tumor growth or tumor angiogenesis. In addition, repression of Rac1 expression does not inhibit VEGF-mediated angiogenesis in vivo or ex vivo, nor does it affect chemotactic migratory responses to VEGF in 3-dimensions. In contrast, the requirement for Rac1 in tumor growth and angiogenesis becomes important when endothelial beta3-integrin levels are reduced or absent: the enhanced tumor growth, tumor angiogenesis and VEGF-mediated responses in beta3-null mice are all Rac1-dependent. These data indicate that in the presence of alphavbeta3-integrin Rac1 is not required for tumor angiogenesis.

The Val allele of HER-2 codon 655 predicts the progression of oral squamous cell carcinoma

HER-2 proto-oncogene is important for oral carcinogenesis. HER-2 codon 655 polymorphism, either isoleucine (Ile: ATC) or valine (Val: GTC), was associated with the risk of breast carcinoma. This study investigated the clinicopathological implications of this polymorphism in oral carcinoma. We found that 79% of oral carcinoma patients had A/A (Ile/Ile) genotype and 21% had A/G (Ile/Val) genotype, with a G (Val) allelic frequency of 0.10. Univariate analysis indicated a significantly higher Val allelic frequency in cases having nodal metastasis or tumor recurrence; and Val allele was associated with poorer recurrence-free survival of patients. Multivariate analysis after adjusting confounding factors by logistic regression analysis indicated that patients carrying Val allele had a 8.79- and 4.25-fold higher risk for nodal metastasis and recurrence, respectively. Using Cox proportional hazard model, the risk of tumor recurrence was 3.35-fold higher in patients carrying Val allele. This is the first report demonstrating that the Val allele of HER-2 codon 655 could be an independent predictor for oral carcinoma progression.

Tumor-microenvironment interactions: dangerous liaisons

The interaction between microenvironmental components and tumor cells is bidirectional. Tumor cells and their products are capable of regulating and altering gene expression in nontumor cells residing in or infiltrating into the microenvironment and exert selective pressures on such cells, thereby shaping their phenotype. Conversely, microenvironmental components regulate gene expression in tumor cells thereby directing the tumor into one or several possible molecular evolution pathways, some of which may lead to metastasis. This review summarizes six instances in which the tumor liaises with different components of its microenvironment. These liaisons result, in most cases, in enhanced tumor progression. In these cases (responses of tumor and nontumor cells to microenvironmental stress, the interaction of the tumor with fibroblasts, endothelial cells and macrophages, the formation of the metastatic niche, and the interaction of the tumor with immunoglobulins) the tumor, directly or indirectly, alters the phenotype of its interaction partners thereby enlisting them to promote its progression. Does the tumor need all these pathways to form metastasis? Is there a hierarchy of interactions with respect to impact on tumor progression? These questions remain open. They may be answered by approaches employed in the analysis of hypercomplex systems.

CD44v4 is a major E-selectin ligand that mediates breast cancer cell transendothelial migration

Background

Endothelial E-selectin has been shown to play a pivotal role in mediating cell–cell interactions between breast cancer cells and endothelial monolayers during tumor cell metastasis. However, the counterreceptor for E-selectin and its role in mediating breast cancer cell transendothelial migration remain unknown.

Methodology/Principal Findings

By assessing migration of various breast cancer cells across TNF-α pre-activated human umbilical vein endothelial cells (HUVECs), we found that breast cancer cells migrated across HUVEC monolayers differentially and that transmigration was E-selectin dependent. Cell surface labeling with the E-selectin extracellular domain/Fc chimera (exE-selectin/Fc) showed that the transmigration capacity of breast cancer cells was correlated to both the expression level and localization pattern of E-selectin binding protein(s) on the tumor cell surface. The exE-selectin/Fc strongly bound to metastatic MDA-MB-231, MDA-MB-435 and MDA-MB-468 cells, but not non-metastatic MCF-7 and T47D cells. Binding of exE-selectin/Fc was abolished by removal of tumor cell surface sialyl lewis x (sLe^x) moieties. Employing an exE-selectin/Fc affinity column, we further purified the counterreceptor of E-selectin from metastatic breast cancer cells. The N-terminal protein sequence and cDNA sequence identified this E-selectin ligand as a ∼170 kD human CD44 variant 4 (CD44v4). Purified CD44v4 showed a high affinity for E-selectin via sLe^x moieties and, as expected, MDA-MB-231 cell adhesion to and migration across HUVEC monolayers were significantly reduced by down-regulation of tumor cell CD44v4 via CD44v4-specific siRNA.

Conclusions/Significance

We demonstrated, for the first time, that breast cancer cell CD44v4 is a major E-selectin ligand in facilitating tumor cell migration across endothelial monolayers. This finding offers new insights into the molecular basis of E-selectin–dependent adhesive interactions that mediate breast cancer cell transendothelial metastasis.

Celecoxib modulates adhesion of HT29 colon cancer cells to vascular endothelial cells by inhibiting ICAM-1 and VCAM-1 expression

BACKGROUND AND PURPOSE

Cyclooxygenase-2 (COX-2) is highly expressed during inflammation and can promote the progression of colorectal cancer. Interactions between cancer cells and vascular endothelial cells are key events in this process. Recently, the selective COX-2 inhibitor, celecoxib, was shown to inhibit expression of the adhesion molecules, ICAM-1 and VCAM-1, in the human colon cancer cell line HT29 and to inhibit adhesion of HT29 cells to FCS-coated plastic wells. Here, we evaluated the effects of celecoxib on adhesion of HT29 cells to human umbilical vein endothelial cells (HUVEC), mediated by ICAM-1 and VCAM-1, to assess further the potential protective effects of celecoxib on cancer development.

EXPERIMENTAL APPROACH

Celecoxib was incubated for 4 h with HT29 cells and HUVEC and adhesion was quantified by a computerized micro-imaging system. Expression analysis of ICAM-1 and VCAM-1 cell adhesion molecules was performed by western blot.

KEY RESULTS

Celecoxib (1 nM-10 microM) inhibited, with the same potency, adhesion of HT29 cells to resting HUVEC or to HUVEC stimulated by tumour necrosis factor-alpha (TNF-alpha), mimicking inflammatory conditions. Analysis of ICAM-1 and VCAM-1 expression showed that celecoxib inhibited expression of both molecules in TNF-alpha-stimulated HUVEC, but not in resting HUVEC; inhibition was concentration-dependent and maximal (about 50%) at 10 microM celecoxib.

CONCLUSIONS AND IMPLICATIONS

In conclusion, our data show that celecoxib inhibits HT29 cell adhesion to HUVEC and expression of ICAM-1 and VCAM-1, in stimulated endothelial cells. These effects may contribute to the chemopreventive activity of celecoxib in the development of colorectal cancer.

Targeting selectins and selectin ligands in inflammation and cancer

Inflammation and cancer metastasis are associated with extravasation of leukocytes or tumor cells from blood into tissue. Such movement is believed to follow a coordinated and sequential molecular cascade initiated, in part, by the three members of the selectin family of carbohydrate-binding proteins: E-selectin (CD62E), L-selectin (CD62L) and P-selectin (CD62P). E-selectin is particularly noteworthy in disease by virtue of its expression on activated endothelium and on bone-skin microvascular linings and for its role in cell rolling, cell signaling and chemotaxis. E-selectin, along with L- or P-selectin, mediates cell tethering and rolling interactions through the recognition of sialo-fucosylated Lewis carbohydrates expressed on structurally diverse protein-lipid ligands on circulating leukocytes or tumor cells. Major advances in understanding the role of E-selectin in inflammation and cancer have been advanced by experiments assaying E-selectin-mediated rolling of leukocytes and tumor cells under hydrodynamic shear flow, by clinical models of E-selectin-dependent inflammation, by mice deficient in E-selectin and by mice deficient in glycosyltransferases that regulate the binding activity of E-selectin ligands. Here, the authors elaborate on how E-selectin and its ligands may facilitate leukocyte or tumor cell recruitment in inflammatory and metastatic settings. Antagonists that target cellular interactions with E-selectin and other members of the selectin family, including neutralizing monoclonal antibodies, competitive ligand inhibitors or metabolic carbohydrate mimetics, exemplify a growing arsenal of potentially effective therapeutics in controlling inflammation and the metastatic behavior of cancer.

TMPRSS4 promotes invasion, migration and metastasis of human tumor cells by facilitating an epithelial-mesenchymal transition

TMPRSS4 is a novel type II transmembrane serine protease found at the cell surface that is highly expressed in pancreatic, colon and gastric cancer tissues. However, the biological functions of TMPRSS4 in cancer are unknown. Here we show, using reverse transcription-PCR, that TMPRSS4 is highly elevated in lung cancer tissues compared with normal tissues and is also broadly expressed in a variety of human cancer cell lines. Knockdown of TMPRSS4 by small interfering RNA treatment in lung and colon cancer cell lines was associated with reduction of cell invasion and cell-matrix adhesion as well as modulation of cell proliferation. Conversely, the invasiveness, motility and adhesiveness of SW480 colon carcinoma cells were significantly enhanced by TMPRSS4 overexpression. Furthermore, overexpression of TMPRSS4 induced loss of E-cadherin-mediated cell-cell adhesion, concomitant with the induction of SIP1/ZEB2, an E-cadherin transcriptional repressor, and led to epithelial-mesenchymal transition events, including morphological changes, actin reorganization and upregulation of mesenchymal markers. TMPRSS4-overexpressing cells also displayed markedly increased metastasis to the liver in nude mice upon intrasplenic injection. Taken together, these studies suggest that TMPRSS4 controls the invasive and metastatic potential of human cancer cells by facilitating an epithelial-mesenchymal transition; TMPRSS4 may be a potential therapeutic target for cancer treatment.

Selectins and selectin ligands in extravasation of cancer cells and organ selectivity of metastasis

Metastatic spreading is a dreadful complication of neoplastic diseases that is responsible for most deaths due to cancer. It consists in the formation of secondary neoplasms from cancer cells that have detached from the primary site. The formation of these secondary sites is not random and several clinical observations indicate that the metastatic colonization exhibits organ selectivity. This organ tropism relies mostly on the complementary adhesive interactions between the cancer cells and their microenvironment. In particular, several lines of evidence suggest that the organ selectivity of colon cancer cells for the liver involves the binding of the circulating cancer cells to endothelial E-selectin. The aim of this review is to make an integrative up-date of the mechanisms that govern the organ selectivity of the metastatic process focusing more especially on the role of selectins and selectin ligands.

The host inflammatory response promotes liver metastasis by increasing tumor cell arrest and extravasation

Inflammation can play a regulatory role in cancer progression and metastasis. Previously, we have shown that metastatic tumor cells entering the liver trigger a proinflammatory response involving Kupffer cell-mediated release of tumor necrosis factor-alpha and the up-regulation of vascular endothelial cell adhesion receptors, such as E-selectin. Here, we analyzed spatio-temporal aspects of the ensuing tumor-endothelial cell interaction using human colorectal carcinoma CX-1 and murine carcinoma H-59 cells and a combination of immunohistochemistry, confocal microscopy, and three-dimensional reconstruction. E-selectin expression was evident mainly on sinusoidal vessels by 6 and 10 hours, respectively, following H-59 and CX-1 inoculation, and this corresponded to a stabilization of the number of tumor cells within the sinuses. Tumor cells arrested in E-selectin(+) vessels and appeared to flatten and traverse the vessel lining, away from sites of intense E-selectin staining. This process was evident by 8 (H-59) and 12 (CX-1) hours after inoculation, coincided with increased endothelial vascular cell adhesion molecule-1 expression, and involved tumor cell attachment in areas of intense vascular cell adhesion molecule-1 and platelet endothelial cell adhesion molecule-1 expression. Nonmetastatic (human) MIP-101 and (murine) M-27 cells induced a weaker response and could not be seen to extravasate. The results show that metastatic tumor cells can alter the hepatic microvasculature and use newly expressed endothelial cell receptors to arrest and extravasate.

Role of S128R polymorphism of E-selectin in colon metastasis formation

The extravasation of cancer cells is a key step of the metastatic cascade. Polymorphisms in genes encoding adhesion molecules can facilitate metastasis by increasing the strength of interaction between tumor and endothelial cells as well as impacting other properties of cancer cells. We investigated the Ser128Arg (a561c at the nucleotide level) polymorphism in the E-selectin gene in patients with metastatic colon cancer and its functional significance. Genotyping for a561c polymorphism was performed on 172 cancer patients and on an age-matched control population. The colon cancer group was divided into groups with (M(+)) and without observable metastasis (M(-)). For in vitro functional assays, Huvec transfected cells expressing wild-type (WT) or the S128R variant of E-selectin were established to study in vitro binding ability and signal transduction processes of T84 colon cancer cell line. Our results demonstrated that the Arginine(128) allele was more prevalent in the M(+) group than in the M(-) group or normal controls (p < 0.005; odds ratio, 1.56; 95% confidence interval (CI) 1.16-1.92; p < 0.001, odds ratio = 1.65; CI = 1.24-1.99, respectively). In vitro, S128R E-selectin transfected Huvec cells, supported increased adhesion as well as increased cellular signaling of T84 cancer cells compared to WT E-selectin and mock-transfected Huvec cells. These findings suggest that the E-selectin S128R polymorphism can functionally affect tumor-endothelial interactions as well as motility and signaling properties of neoplastic cells that may modulate the metastatic phenotype.

Death receptor-3, a new E-Selectin counter-receptor that confers migration and survival advantages to colon carcinoma cells by triggering p38 and ERK MAPK activation

E-selectin-mediated adhesion of colon cancer cells to endothelial cells is a key event in metastasis. However, the signaling mechanisms that confer metastatic advantages to cancer cells adhering to E-selectin are ill defined. By using affinity column chromatography and pull-down assays on purified membrane extracts of HT29 and LoVo cells coupled to mass spectrometry analysis, we obtained the first evidence indicating that E-selectin binds to death receptor-3 (DR3) expressed by the cancer cells. Thereafter, we accumulated several results, suggesting that DR3 is an E-selectin receptor on colon cancer cells and that its activation by E-selectin triggers the activation of p38 and extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) and confers migration and survival advantages. First, by Western blotting, we found that the E-selectin-binding protein, identified as DR3, is recognized by two anti-DR3 antibodies. Second, the neutralization of DR3 with an antibody and its knockdown by small interfering RNA decrease the adhesion of colon cancer cells to E-selectin and E-selectin-expressing human umbilical vein endothelial cells. Third, inhibiting DR3 and knocking down its expression impair transendothelial migration of HT29 cells and block the activation of p38 and ERK by E-selectin. Fourth, high molecular weight isoforms of DR3 are expressed in samples of primary human colon carcinoma but not in samples from normal colon tissue. Intriguingly, DR3 is a death receptor but its activation by E-selectin does not induce apoptosis in colon cancer cells, except when ERK is inhibited. Our findings identify novel signaling and functional roles of DR3 activated in response to E-selectin and highlight the potential link between DR3 and metastasis.

How molecular imaging is speeding up antiangiogenic drug development

Drug development is a long process that generally spans about 10 to 15 years. The shift in recent drug discovery to novel agents against specific molecular targets highlights the need for more robust molecular imaging platforms. Using molecular probes, molecular imaging can aid in many steps of the drug development process, such as providing whole body readout in an intact system, decreasing the workload and speeding up drug development/validation, and facilitating individualized anticancer treatment monitoring and dose optimization. The main focus of this review is the recent advances in tumor angiogenesis imaging, and the targets include vascular endothelial growth factor and vascular endothelial growth factor receptor, integrin alpha(v)beta(3), matrix metalloproteinase, endoglin (CD105), and E-selectin. Through tumor angiogenesis imaging, it is expected that a robust platform for understanding the mechanisms of tumor angiogenesis and evaluating the efficacy of novel antiangiogenic therapies will be developed, which can help antiangiogenic drug development in both the preclinical stage and the clinical settings. Molecular imaging has enormous potential in improving the efficiency of the drug development process, including the specific area of antiangiogenic drugs.

Involvement of p38alpha mitogen-activated protein kinase in lung metastasis of tumor cells

To study the role of p38 mitogen-activated protein kinase (p38) activity during the process of metastasis, p38alpha(+/-) mice were subjected to an in vivo metastasis assay. The number of lung colonies of tumor cells intravenously injected in p38alpha(+/-) mice was markedly decreased compared with that in wild-type (WT) mice. On the other hand, the time-dependent increase in tumor volume after subcutaneous tumor cells transplantation was comparable between WT and p38alpha(+/-) mice. Platelets of p38alpha(+/-) mice were poorly bound to tumor cells in vitro and in vivo compared with those of WT mice. E- and P-selectin mRNAs were markedly induced in the lung after intravenous injection of tumor cells. However, the induction of these selectin mRNAs in p38alpha(+/-) mice was weaker than that in WT mice. Furthermore, the resting expression levels of E-selectin in lung endothelial cells and P-selectin in platelets of p38alpha(+/-) mice were suppressed compared with those of WT mice. The number of tumor cells attached on lung endothelial cells of p38alpha(+/-) mice was significantly reduced compared with that of WT mice. The transmigrating activity of tumor cells through lung endothelial cells of p38alpha(+/-) mice was similar to that of WT mice. These results suggest that p38alpha plays an important role in extravasation of tumor cells, possibly through regulating the formation of tumor-platelet aggregates and their interaction with the endothelium involved in a step of hematogenous metastasis.

Understanding metastatic SCCHN cells from unique genotypes to phenotypes with the aid of an animal model and DNA microarray analysis

Metastasis of squamous cell carcinoma of the head and neck (SCCHN) is a significant health-care problem worldwide. The 5-year survival rate is less than 50% for patients with lymph node metastases. Understanding the molecular basis of SCCHN metastasis would facilitate the development of new therapeutic approaches to the disease. To identify proteins that mediate SCCHN metastasis, we established a SCCHN xenograft mouse model and performed in vivo selection from a SCCHN cell line using the model. In the fourth round of in vivo selection, significant incidences of metastases in lymph nodes (7/10) and lungs (6/10) were achieved from a derived SCCHN cell line as compared with its parental cells, 1/5 in lymph nodes and 0/5 in lungs. Metastatic cell lines from lymph node metastases and parental cell lines from non-metastatic xenograft tumors were subjected to DNA microarray analysis using an Affymetrix gene chip HG-U133A, followed by data mining studies. The identified metastasis-related genes were further evaluated for their encoding protein products and the metastatic cells were examined by biological analyses. DNA microarray analysis highlighted molecular features of the metastatic SCCHN cells, including alteration of expression of cell-cell adhesion proteins, epithelial cell markers, apoptosis and cell cycle regulatory molecules. Further biological analyses of phenotypic alterations revealed that the metastatic cells gained epithelial-mesenchymal transition (EMT) features and were more resistant to anoikis, which are two of the important phenotypes for metastatic SCCHN.

Phase II trial of bevacizumab in combination with weekly docetaxel in metastatic breast cancer patients

PURPOSE

To evaluate the safety and efficacy of bevacizumab and weekly docetaxel as first- or second-line therapy in patients with metastatic breast cancer (MBC).

PATIENTS AND METHODS

Twenty-seven MBC patients received i.v. bevacizumab at 10 mg/kg on days 1 and 15 in combination with i.v. docetaxel 35 mg/m2 on days 1, 8, and 15 of a 28-day cycle. Primary end points were to assess toxicity, overall response rate, and progression-free survival. A secondary end point was to assess the relationship between plasma endothelial and cell adhesion markers and clinical outcomes.

RESULTS

One-hundred fifty-eight treatment cycles were administered with a median of six cycles (range 1-15 cycles) per patient. The most common grade 4 toxicities per patient were as follows: 2 (7%)-pulmonary embolus, 1 (4%)-febrile neutropenia, and 1 (4%)-infection; grade 3 toxicities were 4 (15%)-neutropenia, 4 (15%)-fatigue, 2 (7%)-neuropathy, 2 (7%)-athralgias, 2 (7%)-stomatitis, 1 (7%)-pleural effusion, and 1 (4%)-hypertension. The overall response rate was 52% [95% confidence interval (95% CI), 32-71%], median response duration was 6.0 months (95% CI, 4.6-6.5 months), and the median progression-free survival was 7.5 months (95% CI, 6.2-8.3 months). In hypothesis-generating univariate and limited multivariate analyses, E-selectin was statistically significantly associated with response to the combination.

CONCLUSION

Bevazicumab in combination with weekly docetaxel is active with acceptable toxicities in MBC. Additional studies evaluating E-selectin as a marker of response to bevacizumab-containing chemotherapy are warranted.

Regulation of transendothelial migration of colon cancer cells by E-selectin-mediated activation of p38 and ERK MAP kinases

The invasive properties of cancer cells depend on their intrinsic motile potential and on their ability to breach the endothelial barrier. In the present work, we investigated the mechanisms by which adhesion of colon cancer cells to E-selectin expressed by endothelial cells regulates the barrier function of these cells and modulates transmigration of cancer cells. We found that the stimulation of E-selectin by activating antibodies or the adhesion of HT-29 cells results in an increase in the activity of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinases. In turn, the activation of p38 and ERK enhances transendothelial permeability and migration of HT-29 cells. We also obtained evidence suggesting that p38-mediated increase in transendothelial migration of cancer cells depends on a myosin light chain phosphorylation-mediated formation of stress fibres. On the other hand, the activation of ERK by E-selectin modulates the opening of interendothelial spaces by initiating the activation of Src kinase activities and the dissociation of the VE-cadherin/beta-catenin complex. We conclude that activation of E-selectin by adhering cancer cells is an important process that regulates the extravasation of colon cancer cells by initiating p38- and ERK-dependent mechanisms that both contribute to regulate the integrity of the endothelial layer.

Mitogen-activated protein kinases, adherens junction dynamics, and spermatogenesis: a review of recent data

Mitogen-activated protein kinases (MAPKs) are important regulators of many cellular processes. In mammalian testes, these kinases are involved in controlling cell division, differentiation, survival and death, and are therefore critical to spermatogenesis. Recent studies have also illustrated their involvement in junction restructuring in the seminiferous epithelium, especially at the ectoplasmic specialization (ES), a testis-specific adherens junction (AJ) type. ES contributes to the adhesion between Sertoli cells at the blood-testis barrier, as well as between Sertoli and developing spermatids (step 9 and beyond) at the adluminal compartment. MAPKs regulate AJ dynamics in the testis via their effects on the turnover of junction-associated protein complexes, the production of proteases and protease inhibitors, and the cytoskeleton structure. In this review, roles of the three major MAPK members, namely extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK, in ES dynamics are critically discussed. An integrated model of how these three MAPKs regulate adhesion function in the seminiferous epithelium is also presented. This model will serve as the framework for future investigation in the field.

The involvement of selectins and their ligands in tumor-progression

About 70 years ago, Peyton Rous described the progression of cancer towards metastasis formation as "the process whereby tumors go from bad to worse". The interactions of tumor cells with endothelium are pivotal steps in this process. This review focuses on the role played by the selectins and their ligands in these interactions and especially in tumor cell extravasation. The working hypothesis of researchers studying tumor cell extravasation is that the tumor cells follow the extravasation strategy of leukocytes in their migration towards inflammatory sites. A significant portion of this review is, therefore, dedicated to the molecular mechanisms underlying leukocyte extravasation and to a comparison between the extravasation strategy employed by leukocytes and tumor cells. The review also summarizes some of the available data on signals generated by selectin-selectin ligand interactions.

Brain metastases: epidemiology and pathophysiology

Metastases are the most common tumors of the central nervous system (CNS), but cancer databases are often incomplete leading to underestimation of the incidence of even symptomatic brain metastases. Brain imaging studies are not routinely performed on neurologically asymptomatic cancer patients and autopsy studies are outdated. Furthermore, while incidence rates for cancers are stable and mortality is decreasing due to earlier detection and better therapy, the incidence of brain metastases appears to be increasing. The pathophysiology of brain metastases is a complex multistage process, mediated by molecular mechanisms; from the primary organ, cancer cells must transform, grow and be transported to the CNS where they can lay dormant for various lengths of time before invading and growing further. Understanding the pathophysiology of brain metastases is of great importance, because it may lead to the development of more efficient therapies to combat brain tumor growth or to possibly make the CNS an undesirable environment for tumor progression.

Beta3 integrins facilitate matrix interactions during transendothelial migration of PC3 prostate tumor cells

BACKGROUND

beta3 integrins play a role in metastatic progression of prostate cancer by mediating adhesion of cancer cells to endothelium and migration through extracellular matrix (ECM). However, the role of beta3 integrins during transendothelial migration (TEM) of prostate tumor cells is poorly understood. We examined the role of beta3 integrins in TEM of PC3 human prostate cancer cells through a monolayer of human lung microvascular endothelial cells (HLMVECs).

METHODS

PC3 cells were challenged with beta3 integrin antibodies or antisense nucleotides and their efficiency to migrate through monolayers of endothelial cells (ECs) was assessed using confocal microscopy.

RESULTS

beta3 integrins in PC3 cells are not localized in focal contacts and their blockade significantly inhibited TEM by over 50% preferentially during late stages of migration. Formation of PC3 cell pseudopodia on matrigel was significantly reduced by beta3 integrin antisense oligonucleotides.

CONCLUSIONS

beta3 integrins play important roles during TEM of PC3 cells while interacting with the matrix underneath the endothelium. These interactions are independent of the ability to cluster beta3 integrins into focal adhesions.

Adhesion of HT-29 colon carcinoma cells to endothelial cells requires sequential events involving E-selectin and integrin beta4

HT-29 colon carcinoma cells attach to TNFalpha-activated human umbilical vein endothelial cells (HUVECs) by their specific binding to E-selectin. This interaction activates, in the cancer cells, the MAPK SAPK2/p38, which leads to their transendothelial migration (Laferrière et al., J Biol Chem 2001; 276: 33762). In this study, we investigated the role of E-selectin in activating integrins to modulate adhesion and regulate integrin-mediated events. Blocking the integrins from HT-29 cells (alpha2, alpha3, alpha6, alphav/beta5, beta1 and beta4) with specific antibodies revealed a role for beta4 integrin in their adhesion to TNFalpha-treated HUVEC. The beta4 integrin-dependent adhesion was maximal after 30 min, whereas the-E-selectin-dependent adhesion was maximal after 15 min. Integrin beta4 became quickly phosphorylated upon addition of HT-29 cells to endothelial cells and the effect was independent of the expression of E-selectin. Moreover, a recombinant E-selectin/Fc chimera did not induce the phosphorylation of beta4. The phosphorylation of beta4 is not required for adhesion since adhesion was not affected in HT-29 cells that express a truncated form of beta4 that is deleted from its cytoplasmic phosphorylatable domain. However, the expression of the non-phosphorylatable deletant of beta4 was associated with decreased transendothelial cell migration underscoring the key role for the cytoplasmic domain of beta4 in cell migration. We suggest: 1) that the adhesion of HT-29 cells to activated endothelial cells follows at least two essential sequential steps involving the binding of E-selectin to its receptor on carcinoma cells and then the binding of beta4 to its own receptor on endothelial cells; 2) that the phosphorylation of integrin beta4 contributes to enhance the motile potential of cancer cells and increase their trans-endothelial migration. Overall, our results indicate that the interaction of metastatic cancer cells with endothelial cells implies a specific sequence of signaling events that ultimately leads to an increase in their efficient transendothelial migration.

Tumor-microenvironment interactions: the fucose-generating FX enzyme controls adhesive properties of colorectal cancer cells

Extravasation of tumor cells is a pivotal step in metastasis formation. This step is initiated by an interaction of extravasating tumor cells with endothelial cells. Among the molecules mediating tumor-endothelium interactions are selectins and their fucosylated ligands. In a previous study, we demonstrated that the fucose-generating FX enzyme regulates the expression of selectin ligands by B and T lymphocytes and by head and neck squamous cell carcinoma cells. It was also shown that the FX enzyme regulated important interaction parameters between these cancer cells and endothelial cells. The present study was aimed to determine whether the FX enzyme controls adhesive interactions between colorectal cancer cells and endothelial cells. The results clearly indicate that this is indeed the case. Overexpressing the FX enzyme by the transfer of FX cDNA to low FX-expressing colorectal cancer cells resulted in an increased adhesive capacity of the transfectants to activated endothelial cells and to recombinant E-selectin. Down-regulating FX levels in colorectal cancer cells expressing high levels of endogenous FX by transfection with small-interfering RNA resulted in a down-regulated expression of the selectin ligand sialyl Lewis-a and a decrease in the adhesive capacity of the transfectants to activated endothelial cells and to recombinant E-selectin. These transfection experiments also indicated that manipulating the levels of the FX enzyme affected global cellular fucosylation and altered the interaction of colorectal cancer cells with some extracellular matrix components such as fibronectin. We also found that highly metastatic colorectal cancer variants express higher levels of FX and of sialyl Lewis-a than low metastatic variants originating in the same tumors. These results lead us to hypothesize that the FX enzyme controls the capacity of colorectal cancer to extravasate and form metastasis. If this hypothesis will be confirmed the FX enzyme could become a target molecule for metastasis prevention.

A single nucleotide polymorphism in the transmembrane domain coding region of HER-2 is associated with development and malignant phenotype of gastric cancer

Alterations of the HER-2 (erbB-2/neu) proto-oncogene have been associated with carcinogenesis and poor prognosis of certain cancers. A single nucleotide polymorphism (Ile/Val, A/G) in the transmembrane domain was reported to be associated with a risk of breast cancer. In our study, we examined the association between the HER-2 polymorphism and gastric carcinoma. The Ile/Ile, Ile/Val and Val/Val genotypes were found in 146 (68.9%), 56 (26.4%) and 10 (4.7%) of 212 gastric cancer patients and in 234 (81.5%), 48 (16.7%) and 5 (1.8%) of 287 control subjects, respectively. The Ile/Val or Val/Val genotype was significantly more frequent in patients than in controls (p = 0.005 and 0.033, respectively). The OR of Val/Val genotype then revealed a significantly enhanced risk of 3.25 (95% CI 1.09-9.70) compared to Ile/Ile genotype; heterozygous Ile/Val genotype showed an intermediate risk of 1.97 (1.27-3.06). In patients, carcinomas of advanced stage were significantly more frequent in patients with Ile/Val or Val/Val genotype than those with Ile/Ile genotype (p < 0.001). The logistic regression analysis for tumor invasion, lymph node metastasis and distant metastasis revealed that lymph node metastasis was most closely associated with the HER-2 genotype. These results suggest that this nucleotide polymorphism in the transmembrane domain-coding region of HER-2 could be associated with development of gastric carcinoma and may serve as a predictor of risk for a malignant phenotype of gastric cancer. The association of HER-2 genotype with clinicopathologic characteristics of gastric cancer was also suggested, which has to be confirmed with a larger sample size.