A study of circulating anti-CD25 antibodies in non-small cell lung cancer

PURPOSE

Tumors can trigger specific immune response to tumor-associated antigens but the precise mechanism remains unclear. Since regulatory T-lymphocytes (Treg) play a crucial role in controlling autoimmune responses, the present work was undertaken to test whether dysfunction of Treg cells could be involved in developing autoimmunity in patients with lung cancer.

METHODS

In this study, we developed an in-house enzyme-linked immunosorbent assay to test circulating anti-CD25 autoantibodies among 272 patients with non-small cell lung cancer (NSCLC) and 226 control subjects matched in age, gender and smoking history.

RESULTS

Mann-Whitney U test showed that the anti-CD25 IgG level was significantly higher in patients with NSCLC than control subjects (Z = -7.48, P < 0.001) while the anti-CD25 IgA level was not significantly changed in the patient group as compared with the control group (Z = -1.34, P = 0.181). Spearman correlation analysis failed to reveal a significant correlation between the levels of anti-CD25 IgG and IgA either in patients with NSCLC (r = -0.034, P = 0.578) or in control subjects (r = 0.055, P = 0.429). ROC analysis showed an AUC of 0.70 for anti-CD25 IgG, in which NSCLC at stage III had the highest AUC (0.75). The sensitivity against a specificity of >90 % was 35.0 % for anti-CD25 IgG assay with an inter-assay deviation of 9.4 %, and 4.0 % for anti-CD25 IgA assay with an inter-assay deviation of 13.0 %.

CONCLUSIONS

Circulating anti-CD25 IgG antibody may be a useful biomarker for prognosis of lung cancer.

MT-MMPs in pre-eclamptic placenta: relationship to soluble endoglin production

INTRODUCTION

Pre-eclampsia is a serious complication of pregnancy, characterized by severe endothelial dysfunction resulting in hypertension, proteinuria and maternal end-organ damage. Soluble endoglin is an anti-angiogenic factor released from placenta that has been linked to severe pre-eclampsia. We recently reported MMP-14 is capable of cleaving endoglin to release soluble endoglin from placenta, however inhibition studies only partially repressed production. To this end we have sought to identify other proteases that mediate endoglin shedding from placenta. MMP-14 is one of six-membrane-type (MT-) MMPs, a sub-family of the MMP superfamily, so named because they are membrane bound. MMP-15 is phylogenetically the closest MMP relative to MMP-14, however its inhibition has no effect on soluble endoglin production from placenta.

METHODS

Here we aimed to characterize the remaining four MT-MMPs (MMP-16, -17, -24 and -25) in severe early-onset pre-eclamptic placenta and assess their relative contribution to soluble endoglin production.

RESULTS

Immunolocalisation studies revealed MMP-16, -24 and -25 were localized to the syncytiotrophoblast, the same site as endoglin, whilst MMP-17 was predominantly localized to fetal vessels and underlying stroma. MMP-17 protein was significantly (p < 0.05) up-regulated in pre-eclamptic placentas compared to gestationally matched pre-term controls, whilst MMP-25 mRNA was significantly (p < 0.05) down regulated. siRNA knockdown of MMP-16, -17, -24 and -25 in syncytialised BeWo cells did not alter soluble endoglin production in vitro.

CONCLUSION

This is the first study to characterize MT-MMP protein localization in human placenta and indicates that MMP-14 is the only MT-MMP that contributes to soluble endoglin production in pre-eclampsia.

Abstract P1-04-03: Knocking down Suppressor of Cytokine Signaling 7 in breast cancer: The role in Insulin-like Growth Factor - I/Phospholipase Cγ-1 signaling

BACKGROUND: Suppressor of Cytokine Signaling 7 (SOCS7) is a member of the SOCS family and is known to interact with Phospholipase Cγ-1 (PLCγ-1), one of the Insulin like Growth Factor - I (IGF-I) receptor downstream molecules. In the present study, we sought to examine the effect of knocking down SOCS7 gene on breast cancer cells growth and migration and to elucidate whether this has involved IGF-I — PLCγ-1 signaling using the PLCγ-1 blocker U73122.

METHODS: Suitable breast cancer cells (MCF7 and MDA-MB-231) were transfected with anti-SOCS7 ribozymal transgene, to create sublines with SOCS7 knockdown that was verified by RT-PCR. The growth and migration of the cells were evaluated in the presence or absence of IGF-I and PLCγ-1 inhibitor using in vitro growth assay and Electrical Cell Impedance Sensing (ECIS) migration assay.

RESULTS: MCF7ΔSOCS7 and MDA-MB-231ΔSOCS7 (SOCS7 knockdown) were constructed. Both sublines showed a higher rate of growth compared to control cells with and without IGF-I stimulation. U73122 treatment did not appear to change this growth outcome. Using ECIS migration assay, it was shown that knocking down SOCS7 had a significant positive effect on the migration of MCF7 and MDA-MB-231 cells, and that both IGF-I treatment and SOCS7 knockdown had a synergistic positive influence on their migration (p &lt; 0.05). We further demonstrated that the impact of U73122 on the IGF-I migratory effect was dependent upon SOCS7 knockdown as it has significantly blocked the stimulatory effect of IGF-I on MCF7ΔSOCS7 and MDA-MB-231ΔSOCS7 migration but not that of the control cells. While SOCS7 has acted to control the IGF-I effect, it appeared to cancel the inhibitory function of U73122, indicating a specific anti - PLCγ-1 role for SOCS7 in IGF-I induced breast cancer cellular migration.

CONCLUSION: SOCS7 loss resulted in increased growth and migration of breast cancer cells and this had a synergistic effect on their response to IGF-I. This role could be related to its interaction with PLCγ-1 during the cellular migration but not the growth. It may be possible that SOCS7 acts through different mechanism to control the cellular growth.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-04-03.

Lower incidence and severity of tomato virus in elevated CO(2) is accompanied by modulated plant induced defence in tomato

Elevation in atmospheric CO(2) concentration broadly affects plant phenology and physiology, and these effects may alter the performance of plant viruses. The effects of elevated CO(2) on the susceptibility of tomato plants to Tomato yellow leaf curl virus (TYLCV) were examined for two successive years in open top chambers (OTC) in the field. We experimentally tested the hypothesis that elevated CO(2) would reduce the incidence and severity of TYLCV on tomato by altering plant defence strategies. Our results showed that elevated CO(2) decreased TYLCV disease incidence (by 14.6% in 2009 and 11.8% in 2010) and decreased disease severity (by 20.0% in 2009 and 10.4% in 2010). Elevated CO(2) also decreased the level of TYLCV coat protein in tomato leaves. Regardless of virus infection, elevated CO(2) increased plant height and aboveground biomass. Additionally, elevated CO(2) increased the leaf C:N ratio of tomato, but decreased soluble protein content in leaves. Notably, elevated CO(2) increased the salicylic acid (SA) level in uninfected and infected plants. In contrast, elevated CO(2) reduced jasmonic acid (JA) in uninfected plants while it increased JA and abscisic acid (ABA) in virus-infected plants. Furthermore, combined exogenous SA and JA application enhanced resistance to TYLCV more than application of either SA or JA alone. Our results suggest that the modulated antagonistic relationship between SA and JA under elevated CO(2) makes a great contribution to increased tomato resistance to TYLCV, and the predicted increases in tomato productivity may be enhanced by reduced plant virus susceptibility under projected rising CO(2) conditions.

MicroRNA-520e suppresses growth of hepatoma cells by targeting the NF-κB-inducing kinase (NIK)

MicroRNAs (miRNAs) are small, non-coding RNAs that can act as oncogenes or tumor suppressor genes in human cancer. Emerging evidence indicates that deregulation of miRNAs contributes to the hepatocarcinogenesis. In the present study, we demonstrated that the levels of miR-520e were dramatically decreased in examined hepatoma cell lines and clinical hepatocellular carcinoma (HCC) tissues. Moreover, we found that DNA hypermethylation in the upstream region of miR-520e resulted in the downregulation of miR-520e. Next, we demonstrated that introduction of miR-520e dramatically suppressed the growth of hepatoma cells in vitro and in vivo, whereas silencing the expression of miR-520e by anti-miR-520e resulted in a promoted cell proliferation, suggesting that miR-520e may be a novel tumor suppressor. Further studies revealed that NF-κB-inducing kinase (NIK) was one of the direct target genes of miR-520e, as miR-520e directly bound to the 3'untranslated region of NIK, which reduced the expression of NIK at the levels of mRNA and protein. Moreover, silencing of NIK was able to inhibit the growth of hepatoma cells, similar to the effect of miR-520e overexpression on growth of hepatoma cells. Meanwhile, the knockdown of NIK expression reversed the enhanced proliferation mediated by anti-miR-520e. In addition, miR-520e significantly decreased the phosphorylation of ERK1/2 (p-ERK1/2) and depressed the transcriptional activity and nuclear translocation of nuclear factor κB (NF-κB) (p65). These results suggest that miR-520e suppresses the growth of hepatoma cells by targeting NIK involving the NIK/p-ERK1/2/NF-κB signaling pathway. Finally, we showed that the intratumoral injection with miR-520e was able to directly repress the growth of hepatoma cells in the nude mice. Thus, our finding provides new insight into the mechanism of hepatocarcinogenesis, indicating a therapeutic potential of miR-520e in the treatment of HCC.

CFTR suppresses tumor progression through miR-193b targeting urokinase plasminogen activator (uPA) in prostate cancer

Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is expressed in the epithelial cells of a wide range of organs/tissues from which most cancers are derived. Although accumulating reports have indicated the association of cancer incidence with genetic variations in CFTR gene, the exact role of CFTR in cancer development and the possible underlying mechanism have not been elucidated. Here, we report that CFTR expression is significantly decreased in both prostate cancer cell lines and human prostate cancer tissue samples. Overexpression of CFTR in prostate cancer cell lines suppresses tumor progression (cell growth, adhesion and migration), whereas knockdown of CFTR leads to enhanced malignancies both in vitro and in vivo. In addition, we demonstrate that CFTR knockdown-enhanced cell proliferation, cell invasion and migration are significantly reversed by antibodies against either urokinase plasminogen activator (uPA) or uPA receptor (uPAR), which are known to be involved in various malignant traits of cancer development. More interestingly, overexpression of CFTR suppresses uPA by upregulating the recently described tumor suppressor microRNA-193b (miR-193b), and overexpression of pre-miR-193b significantly reverses CFTR knockdown-enhanced malignant phenotype and abrogates elevated uPA activity in prostate cancer cell line. Finally, we show that CFTR gene transfer results in significant tumor repression in prostate cancer xenografts in vivo. Taken together, the present study has demonstrated a previously undefined tumor-suppressing role of CFTR and its involvement in regulation of miR-193b in prostate cancer development.

Arrhythmia and sudden death associated with elevated cardiac chloride channel activity

The identification and analysis of several cationic ion channels and their associated genes have greatly improved our understanding of the molecular and cellular mechanisms of cardiac arrhythmia. Our objective in this study was to examine the involvement of anionic ion channels in cardiac arrhythmia. We used a transgenic mouse model to overexpress the human cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes a cAMP-regulated chloride channel. We used RNase protection and in situ hybridization assays to determine the level of CFTR expression, and radiotelemetry and in vivo electrophysiological study in combination with pharmacological intervention to analyse the cardiac function. Cardiac CFTR overexpression leads to stress-related sudden death in this model. In vivo intracardiac electrophysiological studies performed in anaesthetized mice showed no significant differences in baseline conduction parameters including atrial-His bundle (AH) or His bundle-ventricular (HV) conduction intervals, atrioventricular (AV) Wenckebach or 2:1 AV block cycle length and AV nodal functional refractory period. However, following isoproterenol administration, there was marked slowing of conduction parameters, including high-grade AV block in transgenic mice, with non-sustained ventricular tachycardia easily inducible using programmed stimulation or burst pacing. Our sudden death mouse model can be a valuable tool for investigation of the role of chloride channels in arrhythmogenesis and, potentially, for future evaluation of novel anti-arrhythmic therapeutic strategies and pharmacological agents.

New precision limit on the strange vector form factors of the proton

The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624  GeV2 and beam energy E(b) = 3.48  GeV to be A(PV) = -23.80 ± 0.78(stat) ± 0.36(syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G(E)(s) + 0.517G(M)(s) = 0.003 ± 0.010(stat) ± 0.004(syst) ± 0.009(ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.

Investigation of the relationship between SLA-1 and SLA-3 gene expression and susceptibility to Escherichia coli F18 in post-weaning pigs

Porcine post-weaning diarrhea and edema disease are principally caused by Escherichia coli strains that produce F18 adhesin. FUT1 genotyping and receptor binding studies divided piglets into E. coli F18-resistant and -sensitive groups, and the roles of SLA-1 and SLA-3 were investigated. SLA-1 and SLA-3 expression was detected in 11 pig tissues, with higher levels of SLA-1 in lung, immune tissues and gastrointestinal tract, and higher levels of SLA-3 also in lung and lymphoid tissues. Both genes were expressed higher in F18-resistant piglets, and their expression was positively correlated in different tissues; a negative correlation was observed in some tissues of F18-sensitive group, particularly in lung and lymphatic samples. Gene ontology and pathway analyses showed that SLA-1 and SLA-3 were involved in 37 biological processes, including nine pathways related to immune functions. These observations help to elucidate the relationship between SLA class I genes and E. coli F18-related porcine gastrointestinal tract diseases.

P5-07-07: Follistatin Suppresses In Vitro Growth of Breast Cancer Cells and Its Reduced Expression in Breast Cancer Associated with Poor Differentiation and Prognosis

Background: Bone morphogenetic protein (BMP) belongs to TGF-β superfamily, being widely involved in prenatal and postnatal development and homeostasis of various tissues and organs. BMP signaling has been implicated in tumorigenesis and disease progression of certain malignancies. Recent studies demonstrated a profound role played Noggin, a BMP antagonist in bone metastasis from breast cancer. Current study examined expression of Follistatin, another BMP antagonist in a breast cancer cohort, and its relevance to pathological and clinical parameters.

Methods: Expression of Follistatin was examined in breast cancer tissues (n=93) and normal background tissues (n=30) using quantitative real time PCR and immunhistochemistry (IHC). The breast tissue samples were collected immediately after surgery. The clinical follow-up was routinely performed after surgery. The median follow-up period was 120 months (June 2004). Full-length human Follistatin coding sequence was cloned into a plasmid vector. Following transfection and verification, effect of Follistatin overexpression on cell growth was examined using an in vitro growth assay.

Results: IHC revealed cytoplamic staining of Follistatin in mammary epithelial cells in breast tissues. The staining appeared to be weaker in breast cancer, but there was no significant difference in its transcripts levels compared with that of normal background tissues. Follistatin transcripts were decreased in both moderately differentiated and poorly differentiated tumors, p=0.0165 and p=0.0169 in comparison with well differentiated tumors respectively. Transcript levels of Follistatin in primary tumors tended to be lower in the patients with poor prognosis (33.8±14.7) including those patients had local recurrence, metastases and died of breast cancer, p=0.09 when compared with that of patients remained disease free (117.0±46.0). Its expression appeared particularly lower in the patients died of the disease (21.8±12.0), p=0.05 v.s. disease free. Over-expression of Follistatin exerted inhibitory effect on in vitro growth of MDA-MB-231 cells.

Conclusions: Decreased expression of Follistatin in primary tumors of breast cancer correlates with poorer differentiation and mortality. Follistatin suppresses in vitro growth of breast cancer cells. It suggests that Follistatin is a negative regulator for tumor growth and disease progression of breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-07-07.

P2-05-05: Receptor-Like Protein Tyrosine Phosphatase Kappa (PTPRK) and Its Biological Role in Angiogenesis

Introduction: Protein Tyrosine Phosphatases (PTPs) are known as signalling molecules which affect cell growth, differentiation and oncogenic transformation. PTPs have been indicated in tumourigenesis and progression of various solid tumours. PTPRK, receptor-type protein tyrosine phosphatase kappa, has been shown to down-regulate transcriptional activity of beta-catenin and impact distribution of beta-catenin/E-cadherin complexes on cancer cell membrane. However, the role played by PTPRK in angiogenesis remains unknown. In present study, the effect of PTPRK knock-down on functions and tubule formation ability of HECV cells was investigated. (or In the present study, the effect of PTPRK on angiogenesis process was investigated.)

Methods: anti-PTPRK ribozyme transgenes were constructed to knock-down PTPRK expression in vascular endothelial cells, HECV cells. The subsequent effect upon in vitro cell growth, adhesion, migration and microvascular tubule formation was examined using a variety of functional assays.

Result: Knock-down PTPRK in HECV cells (HECVΔPTPRK) resulted in a decrease of cell growth in vitro. The growth rate of HECVΔPTPRK was 276.3±16.4, p=0.01 compared with HECVpEF (314.8±21.9) controls. However, knock-down of PTPRK in HECV cells increased cell motility. The cell migration distance of HECVΔPTPRK was 83.8±19.8μm, p=0.008 compared with HECVpEF (61.8±11.8μm) controls. No effect on cell adhesion by PTPRK knockdown was seen in HECVΔPTPRK (81.2±6.6), compared with HECVpEF control (78.8±15.6). Furthermore, knock-down of PTPRK suppressed tubule formation in HECV cells, the length of total tubules (μm) in HECVΔPTPRK was 2167.4±943.2, p&lt;0.05 compared with HECVpEF (3130.6±386.9) control.

Conclusion: Knock-down of PTPRK reduced the growth and tubule formation abilities of vascular endothelial cells. It suggests that PTPRK is pivotal regulator for angiogenic process. Further investigations are required to identify the downstream pathways involved in these impacts.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-05-05.

P2-01-19: Expression of Receptor Like Protein Tyrosine Phosphatases mu (PTPRM) in Breast Cancer and the Biological Effects of PTPRM on Breast Cancer Cells

Introduction: Protein tyrosine phosphatases (PTPs) play a major role in many cellular functions including cell survival, proliferation, differentiation and motility. The receptor-like protein tyrosine phosphatase mu (PTPRM) has a similar structure to cell-cell adhesion molecules and has been shown to exhibit homophilic binding and confer cell-cell adhesion in cells including epithelial and cancer cells. However, the role played by PTPRM in breast cancer remains unclear. The present study investigated the expression of PTPRM in breast cancer and the biological impact of PTPRM on breast cancer cells.

Methods: Expression of PTPRM protein and gene transcript was examined in a cohort of primary breast cancer tumours. The association of PTPRM transcripts level and pathological and clinical aspects was then analysed. Expression of PTPRM transcript in breast cancer cells were knocked down using a specific anti-PTPRM transgene. The impact of PTPRM knockdown on breast cancer was evaluated using a series of in vitro cell models and in vivo tumour model.

Result: PTPRM protein was seen generally distributed in the breast tissues, including tumours and normal background tissues. A stronger staining was revealed in cytoplasm of both mammary epithelia and cancer cells in comparison with the surrounding stromal cells. A significantly decrease was seen in poorly differentiated tumours (92.5±279), and moderately differentiated tumours (288±110), compared with that of well differentiated (472±114), p=0.011 and p=0.031 respectively. PTPRM transcript levels were decreased in patients died from breast cancer. The expression of PTPRM transcripts was significantly associated with disease free survival. Patients with lower expression of PTPRM had shorter survival compared with those with high level of PTPRM expression (p=0.029). Knocking down PTPRM from breast cancer cells significantly increased cell adhesion compared with control cells (p&lt;0.001). Likewise, the knockdown also marked increase the rate of cell migration (102.9±11.3μm for control vs 115.3±10.5μm for PTPRM knockdown, p&lt;0.05).

Conclusion: The expression of PTPRM transcripts is decreased in poorly differentiated breast tumours and is correlated with poorer long term survival. This is likely to be contributed to by the biological impact of PTPRM on the aggressiveness of breast cancer cells.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-01-19.

P3-18-01: cMET Inhibitor and the Inhibition of Growth of Breast Cancer Cells in Bone Marrow Matrix Environment

Background: Hepatocyte growth factor (HGF) is a cytokine that has a diverse but potential role in cancer including breast cancer. HGF, which action is mediated by its specific receptor, cMET, stimulate the aggressiveness of cancer cells by increasing the invasiveness and cellular migration. HGF is also a potent angiogenic factor. Small inhibitors to the HGF receptor are currently investigated in clinical trials of various cancers. In solid tumours which have potency of bone metastasis, HGF and particularly the HGF receptor, cMET, have been found to be particularly over-expressed in tumour cells metastasised to bones.

Materials and methods. A panel of breast cancer cell lines were used. Cell growth was determined using a colorimetic method. Cell adhesion and migration were investigated using a ECIS model. Bone matrix proteins were prepared from fresh bones. A small inhibitor to human cMET, PF02341066 was used in the present study in all the cell models.

Results. Depending on cell types, cancer cells tended to grow at a faster rate in bone marrow microenvironment than under normal conditions (12% higher for MDA MB 231 cells, for example). While PF02341066 have a concentration dependent effect on the growth of breast cancer, this effect became more marked when cells were growing in the bone marrow matrix. Breast cancer cells migrated rapidly in the presence of bone marrow environment, in comparison with controls. This was also inhibited by the cMET inhibitor. The study further showed that cells over-expressing a molecule linked to bone metastasis, namely ALCAM (1,2), responded more vigorously to cMET inhibitor in the matrix adhesion and cellular migration.

Conclusions. The present study has shown that the HGF receptor inhibitor has an inhibitory effect on breast cancer cells. This is particularly so when cells are grown in bone matrix microenvironment. It is concluded therefore that inhibitors to the HGF receptor may have a particular role in the management of bone metastasis in breast cancer.

References: 1. Davies S, Jiang WG. ALCAM, activated leukocyte cell adhesion molecule, influences the aggressive nature of breast cancer cells, a potential connection to bone metastasis. Anticancer Res. 2010, 30(4):1163–8; 2. King JA, et al. Activated leukocyte cell adhesion molecule in breast cancer: prognostic indicator. Breast Cancer Res. 2004;6(5):R478–87

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-18-01.

P1-01-08: Expression of Interleukin-15 (IL-15) and the IL-15 Receptor in Human Breast Cancer

Introduction: Interleukin-15 (IL15) is a cytokine that influences activation and proliferation of T-lymphocytes. IL-15 is produced in the body leukocytes such as phagocytes and in many ways has similar immunoregulatory functions to IL-2 including stimulation of NK cells and CD8(+) T cells. It has been suggested that IL-15 may increase the immunity to cancer cells and cancer cell's response to therapeutic agents. IL-15 has also been shown to be able to inhibit tumour growth in vivo. However, the expression profile of IL-15 and IL-15 receptor (IL-15) in solid tumours including human breast cancer is not clear. The present study investigated the expression profile of both IL-15 and IL-15R in human breast cancer and deduced a clinical and pathological relevance with breast cancer.

Methods: Immunohistochemical methods were used to detect IL-15 and IL-15RA in mammary tissues. IL-15 and IL-15RA transcripts were analysed using real-time quantitative PCR method. Levels of IL-15 and IL-15RA were compared in normal and tumour tissues as well as against tumour staging, nodal status, disease progression and clinical outcome after a 10-year followup.

Results: Both IL-15 and IL-15RA were detectable in mammary tissues and were seen in both epithelial cells and infiltrating cells. Node positive tumours had low levels of IL-15 compared with node negative tumours (21.7±10 vs 103±46, respectively). Late stage tumour also had lower levels of IL-15 (95±43, 31±15, 3.7±2 and 1.3±1.15 for stage I, II, III and IV tumours respectively. p=0.036 and p=0.032, stage-II and Stage-III vs stage-I). Patients with metastatic disease (10.3±3) and patients died of breast cancer related conditions (8.5±6) had markedly low levels of IL-15 when compared with those who were disease free (54.7±25). The disease free survival time for patients with low levels IL-15 was 126 (114-138, 95%CI) months, compared with 139 (131-148) months for those with high levels of IL-15. Despite the reduced expression of IL-15 in aggressive tumours, expression of IL-15 receptor, IL-15RA, did not display a significant change and failed to showed a link with nodal status, tumour staging and clinical outcome.

Conclusions: Interleukin-15, an immuoregulatory cytokine, has an aberrant expression in human breast cancer. Low levels of IL-15, but not IL-15 receptor, is associated with the aggressiveness and disease progression of breast cancer. Together with reported effect of IL-15 on NK cells and other anti-tumour lymphocytes, IL-15 appears to be a useful therapeutic option.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-01-08.

P2-05-06: Role of Repulsive Guidance Molecule b (RGMb) in HGF Mediated Angiogenesis

Introduction: Hepatocyte Growth Factor (HGF) has been widely documented as playing a key role in enhancing the aggressive nature of cancer through its ability to promote cellular processes such as migration, invasion and angiogenesis. Development of a blood supply is vital to advanced tumour growth and increased metastatic potential. In the current study we identified RGMb (DRAGON), a member of the Repulsive Guidance Molecule family, as being upregulated by HGF and assessed its potential to contribute to HGF mediated proangiogenic traits.

Methods: Expression of RGMb was identified as being upregulated in human endothelial HECV cells following 4 hour treatment with HGF (40ng/ml) using micro array analysis and Q-PCR. Subsequently, the expression of RGMb was targeted through the transfection of HECV cells with a plasmid containing a ribozyme transgene specifically targeted to RGMb. The role of RGMb in HGF mediated cellular migration and tubule formation in vitro was examined.

Results: Significant increases in RGMb expression in HECV cells were observed on the mirco-array following 4 hour treatment with HGF (P = 0.004) and this trend was also identified using Q-PCR. Transfection with the ribozyme transgene brought about substantial reductions in RGMb expression at both transcript and protein levels as assessed using RT-PCR, QPCR and Western blot analysis. Knockout of RGMb brought about a significant increase in migration rates, compared to HECV cells transfected with a closed pEF6 plasmid only (HECVpEF6), following a 90minute period (p = 0.034 at 90 minute time point vs pEF6 control). Treatment of HGF enhanced migration rates of HECV control cells with significant differences between untreated and HGF treated pEF6 cells obvious following 60 minutes (p &lt; 0.05 at 60 and 75 minutes, p = 0.002 at 90 minutes). In contrast to this, HECV cells transfected with the RGMb ribozyme transgene (HECVRGMbKO) were unaffected by HGF treatment, with no significant differences observed between treated or untreated HECVRGMbKO cells at any time points. A similar trend was observed in the angiogenic tubule formation assay, where treatment of HECVpEF6 cells with HGF could significantly enhance the levels of tubules formed (mean tubule perimeter, untreated 8087+/− 632 vs HGF treated 13131+/− 988, p = 0.001). Treatment of HECVRGMbKO cells with HGF did not significantly enhance levels of tubule formation (mean tubule perimeter, untreated 7523+/−2458 vs HGF treated 11050+/−1512, p = 0.21).

Conclusions: Targeting of RGMb in endothelial cells appears to reduce their sensitivity to the promotional effect of HGF on cell migration and tubule formation, important traits in the angiogenic cascade. Our data suggests that RGMb may be one molecule involved in the process through which HGF enhances angiogenic potential and targeting this molecule may be a useful strategy in a number of cancer types to interfere with HGF promoted angiogenesis.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-05-06.

Polymorphism of M307 of the FUT1 gene and its relationship with some immune indexes in Sutai pigs (Duroc x Meishan)

The alpha (1,2)fucosyltransferase (FUT1) gene has been identified as a candidate gene for controlling the expression of the enterotoxigenic Escherichia coli (ETEC) F18 receptor. Polymorphisms were detected at the M307 position in FUT1 of a breeding base population of Sutai pigs and their correlations to immune parameters analyzed. After digestion by Hin6I, three genotypes were identified at M307, AA (frequency 0.235), AG (0.609), and GG (0.156), with significant deviation from Hardy-Weinberg equilibrium (P < 0.01). The hemoglobin and white blood cell count of the AA genotype pigs were significantly higher than those of AG and GG pigs (P < 0.05). The results indicated that AA pigs not only are resistant to edema disease and post-weaning diarrhea in piglets but also have relatively strong resistance to disease in general.

Performance of sequential organ failure assessment, logistic organ dysfunction and multiple organ dysfunction score in severe sepsis within Chinese intensive care units

This study assessed the performance of Sequential Organ Failure Assessment, Logistic Organ Dysfunction Score and Multiple Organ Dysfunction Score in outcome prediction in severe sepsis. A total of 528 consecutive patients with a diagnosis of severe sepsis were enrolled from two surgical intensive care units of university hospitals in China. Clinical and laboratory data of patients were collected and admission and maximum values of each scoring system were calculated. Areas under the receiver operating characteristic curve, which were used to assess discrimination, were 0.80, 0.83 and 0.74 for admission Sequential Organ Failure Assessment, Logistic Organ Dysfunction Score and Multiple Organ Dysfunction Score respectively, and 0.91, 0.93 and 0.86 for corresponding maximum values respectively. Calibration assessed by the Hosmer-Lemeshow statistic was better with admission (chi2 = 18.2) and maximum Logistic Organ Dysfunction Score (chi2 = 19.6) than with admission (chi2 = 98.1) and maximum Multiple Organ Dysfunction Score (chi2 = 30.9). Brier Scores, indicating the overall performance of the scores, were 0.18, 0.17 and 0.22 for admission Sequential Organ Failure Assessment, Logistic Organ Dysfunction Score and Multiple Organ Dysfunction Score respectively, and 0.12, 0.10 and 0.15 for their maximum counterparts respectively. This study found good performance of both admission Sequential Organ Failure Assessment and Logistic Organ Dysfunction Score in severe sepsis, and a slightly weaker performance of admission Multiple Organ Dysfunction Score. Since poor calibration was observed in Logistic Organ Dysfunction Score and Multiple Organ Dysfunction Score, we suggest further study of customisation of these scores in critical illness with severe sepsis.