Translocation of protein kinase C isoforms is involved in propofol-induced endothelial nitric oxide synthase activation

BACKGROUND

Previous studies have indicated that protein kinase C (PKC) may enhance endothelial nitric oxide synthase (eNOS) activation, although the detailed mechanism(s) remains unclear. In this study, we investigated the roles of PKC isoforms in regulating propofol-induced eNOS activation in human umbilical vein endothelial cells (HUVECs).

METHODS

We applied western blot (WB) analysis to investigate the effects of propofol on Ser(1177) phosphorylation-dependent eNOS activation in HUVECs. Nitrite (NO(2)(-)) accumulation was measured using the Griess assay. The phosphatidylinositol 3-kinase/Akt (PI3K/Akt) pathway was examined by WB assay. Propofol-induced translocation of individual PKC isoforms in subcellular fractions in HUVECs was analysed using WB assay.

RESULTS

In HUVECs, protocol treatment (1-100 microM) for 10 min induced a concentration-dependent increase in phosphorylation of eNOS at Ser(1177). The NO production was also increased accordingly. PKC inhibitors, bisindolylmaleimide I (0.1-1 microM), and staurosporine (20 and 100 nM), effectively blocked propofol-induced eNOS activation and NO production. Further analyses in fractionated endothelial lysate showed that short-term propofol treatment (50 microM) led to translocation of PKC-alpha, PKC-delta, PKC-zeta, PKC-eta, and PKC-epsilon from cytosolic to membrane fractions, which could also be inhibited by both PKC inhibitors. These data revealed that the differential redistribution of these isozymes is indispensable for propofol-induced eNOS activation. In addition, Akt was not phosphorylated in response to propofol at Ser(473) or Thr(308).

CONCLUSIONS

Propofol induces the Ser(1177) phosphorylation-dependent eNOS activation through the drug-stimulated translocation of PKC isoforms to distinct intracellular sites in HUVECs, which is independent of PI3K/Akt-independent pathway.

Preliminary study of the presence and association of bacteria and archaea in teeth with apical periodontitis

AIM

To investigate, by reverse transcription polymerase chain reaction (RT-PCR), the presence and association of bacteria and archaea in primary and secondary root canal infections.

METHODOLOGY

A total of 77 root canal samples from 77 Chinese patients, 42 with necrotic pulp tissues (primary infection) and 35 with failed prior conventional root canal treatment (secondary infection), aseptically exposed at the first patient visit, were studied. Total RNA was isolated directly from each sample, and 16S rRNA gene-based RT-PCR assays were used to determine the presence of bacteria and archaea, respectively.

RESULTS

Bacteria were detected in 39/42 (93%) of root canal samples from teeth with primary infections, and archaea in 16/42 (38%). In the cases diagnosed as secondary root-infected canals, bacteria were detected in 30/35 (86%), whilst archaea were detected in 6/35 (17%) of cases. Amongst the canals, which were positive for bacteria, archaea were always found in combination with bacteria. The incidence of symptomatic cases positive for both bacteria and archaea (16/22, 73%) were significantly higher than those positive for bacteria alone (21/47, 45%) (P < 0.05).

CONCLUSIONS

This study confirms the presence of archaea in root canal infections and further implicates them in an association with clinical symptoms. The nature of this association requires further study.

Genetic characterisation of drug-resistant Mycobacterium tuberculosis in rural China: a population-based study

OBJECTIVES

A population-based study was performed to characterise the genotype and phenotype of drug-resistant tuberculosis (TB) in the year 2004-2005 in two Chinese rural counties with different durations of DOTS implementation, Deqing and Guanyun.

METHODS

Mycobacterium tuberculosis strains were isolated from respectively 164 and 187 patients registered at local TB dispensaries of Deqing and Guanyun. Drug susceptibility profiling and DNA sequencing were performed on the isolates.

RESULTS

A total of 223 isolates from 223 patients were identified as resistant to first-line drugs, of which 53 were multidrug-resistant TB (MDR-TB, i.e., resistant to isoniazid [INH] and rifampicin [RMP]). Mutations in katG were identified in 81 of 131 INH-resistant isolates (61.8%), all of which harboured the mutation in codon 315. Mutations related to RMP resistance occurred mostly in codon 531, 526 and 516 of the rpoB gene. Seventy-eight of the 115 streptomycin-resistant isolates carried a mutation in the rpsL gene at codon 43 or 88. A mutation in codon 306 of embB occurred in 21 ethambutol (EMB) resistant and 19 EMB-susceptible isolates.

CONCLUSIONS

Our data indicated that DNA sequencing of specific codons of the rpoB gene should be effective for predicting RMP resistance and MDR-TB in rural China.

Growth inhibition of Microcystis aeruginosa by white-rot fungus Lopharia spadicea

Harmful cyanobacterial blooms cause water deterioration and threaten human health. It is necessary to remove harmful cyanobacteria with useful methods. A bio-treatment may be one of the best ways to do this. A strain of specific white-rot fungus, Lopharia spadicea, with algicidal ability was isolated. Its algicidal ability on algae under various conditions was determined using three main influence factors: initial chlorophyll-a content, initial pH, and algal cell mixture. The result showed that the chlorophyll-a content of Microcystis aeruginosa FACHB-912, Oocystis borgei FACHB-1108, and Microcystis flos-aquae FACHB-1028 decreased from 798+/-13, 756+/-40, and 773+/-24 microg/L to 0 within 39 h. L. spadicea could also remove more than 95% chlorophyll-a when initial chlorophyll-a content increased from 397+/-13 to 2,132+/-4 microg/L. Moreover, the strain has great removal ability under a broad initial pH range of 5.5 to 9.5. The chlorophyll-a content of the three algal strain mixtures decreased from about 672+/-23 microg/L to 0 within 45 h. After superoxide dismutase (SOD) and malondialdehyde (MAD) were assessed in a co-culture of L. spadicea, it was observed that an increase in MAD content was correlated with the decrease in chlorophyll-a content of M. aeruginosa FACHB-912. This result suggested that the algae was not only greatly inhibited but also severely damaged by the fungus.

The Role of Dragon (Repulsive Guidance Molecule-B, RGM-B) in Human Breast Cancer

Introduction: Repulsive guidance molecules (RGMs) are involved in embryonic development and iron homeostasis. RGM-A mediates repulsive axonal guidance and neural tube closure, and RGM-C is mutated in juvenile hemochromatosis. RGM-B, also known as Dragon, is a myelin-derived inhibitor of axon growth in the central nervous system. The RGM family was also identified as co-receptors of bone morphogenetic proteins (BMPs), a group of proteins that are involved in development of bones, the differentiation and progression of cancer. However, the role of RGMs played in breast cancer remains unclear. In the present study, we examined the pattern of expression of the RGM family in human breast cancer cells and investigated the impact of Dragon (RGM-B) on BMP-induced cell function in breast cancer cells.Material and Methods: Conventional RT-PCR was performed to screen the expression of RGMs in human breast cancer samples and a range of breast cancer cell lines. Dragon/RGM-B ribozyme transgenes were generated and in order to knock down the Dragon transcript. Subsequently, MDA-231RGMB-Knock-down variants were created by way of the transgenes. A series of cell function assays were employed to investigate any biological effects upon RGM-B knockdown on the breast cancer cells as well as cell's response to recombinant BMP proteins.Results: RGM-A and RGM-C transcripts were barely detectable in breast cancer cell lines (MDA-MB-231 and MCF-7) and tissues. However RGM-B transcripts were expressed in both cell lines. Using anti-RGM-B transgenes, MDA-231RGMB-Knock-down variant cell lines, in which RGM-B transcripts were knocked down, were created. Compared with wild type and control transfection, MDA-231RGMB-Knock-down variants displayed a significant increase in both the adhesiveness and cells growth (p &lt; 0.05, vs the respective controls, for adheresion and for cell growth). Interestingly, RGM-B knockdown did not have any significant effects on the invasiveness of the cells. Finally, wild type breast cancer cells and the RGMB knock down variant cell lines showed a similar response to the treatment with rhBMP-11, indicating that RGM-B is less critical in BMP-11 mediated cell functions.Conclusion: The present study is the first to examine the role of RGM-B in breast cancer and has demonstrated that knock-down of RGMB could enhance breast cancer cells' ability to grow and attach, indicating that RGM-B may act as an inhibitor in breast cancer. This property is unique to RGMB, as this ability is not associated with any other member in the RGM family.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6158.

BMPR-II Mediates Positive Regulation on In Vitro Cell Growth, the Potential Implications for Breast Cancer

Introduction: Breast cancer is the primary type of female cancer in the UK. We have recently shown that reduced expression of BMPR-IB correlates with poor prognosis, and may be useful as a prognostic indicator in breast cancer (1). This current study aimed to see if a role for the BMP type II receptor (BMPR-II), also exists in the progression of breast cancer.Methods: Expression of BMPR-II was examined in a cohort of 32 normal breast tissue and 112 primary breast tumour tissue samples. Transcript levels of BMPR-II were then determined using quantitative real time-PCR and protein levels were assessed using immunohistochemical (IHC) staining. Finally, ribozyme transgenes were constructed to knock-down BMPR-II expression in MDA-MB-231 cells. The effect this had in vitro cell growth was examined.Results: In normal breast tissue, IHC staining demonstrated strong expression of BMPR-II, specifically in the epithelial cells. In comparison to the normal breast tissue, reduced expression of BMPR-II was evident in the breast tumour samples. BMPR-II transcript levels were further determined using Q-PCR. A trend was evident in that patients with poor prognosis (0.012±0.09) including those with metastasis, local recurrence and breast cancer deaths, demonstrated reduced BMPR-II expression compared to disease free patients (33±13, p=0.09 vs. poor prognosis). Furthermore, lower expression levels were seen in patient samples with a Nottingham Prognosis Index (NPI) greater than 5.4 (poor prognosis group) (18±17) compared to those with NPI &lt;3.4 (good prognosis group) (41±18, p=0.19). Finally, BMPR-II expression was markedly lower in advanced breast cancer of TNM stage 3 and 4 (0±0.1) compared with those of early stage of the disease (TNM1, 46±17, both p&lt;0.01). Despite the clear trend seen, the majority of the data was not found to be significant, suggesting that unlike BMPR-IB, BMPR-II is less useful in predicting prognosis of breast cancer. However, knocking down BMPR-II expression in MDA-MB-231 breast cancer cell line resulted in a reduction of in vitro cell growth, suggesting BMPR-II may play a positive role in breast cancer cell growth. The absorbance of MDA-MB-231BMPR-IIKO cells at day 5 was 1.29±0.09, p&lt;0.01 compared with MDA-MB-231WT (1.90±0.18) and MDA-MB-231GFP control cells (2.30±0.23).Conclusion: This study reveals a trend for BMPR-II in that its expression appears to be reduced in breast cancer patients with poor prognosis. Despite this, it is not as useful of a prognostic indicator as its type I counterpart BMPR-IB, suggesting that in breast cancer progression, BMPR-IB plays a more important role. However, reduced expression of BMPR-II in MDA-MB-231 resulted in a promotion of cell growth, suggesting that BMPs in breast cancer cells may act via BMPR-II to promote tumour growth. However, this needs further investigation.Reference:1. Bokobza SM, et al. Reduced expression of BMPR-IB correlates with poor prognosis and increased proliferation of breast cancer cells. Cancer Genom Proteom, 2009, 6, 101-108

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3039.

The Hepatitis A Virus Cellular Receptor, HAVcR-1, Reduces the Integrity of Human Endothelial Tight Junctions

Background: Disruption of Tight Junctions (TJ's) in endothelial cells can cause a leaky vascular bed and may therefore lead to vascular spread of cancer cells. Hepatitis A virus (HAV) cellular receptor HAVcR-1, also known as KIM-1/TIM-1, is the cellular receptor for the hepatotropic picornavirus that causes acute hepatitis-A in humans. Although HAVcR-1 is expressed in every human organ, the natural function of HAVcR-1 remains unknown. In the current study, we investigated the location, association and possible functionality of HAVcR-1 in human endothelial cells.Methods: HAVcR-1 protein in human endothelial cells was visualised using immunohistochemistry and mRNA transcript by RT-PCR. A hammerhead ribozyme transgene that specifically targeted human HAVcR-1 was constructed and used to knockdown endogenously expressed HAVcR-1 (HECVHKD); moreover, forced expression was obtained by insertion of a transgene into wild type endothelial cells (HECVHEX).TJ function was assessed using trans-endothelial resistance (TER) and paracellular permeability assays under the influence of HGF (40ng/ml) a cytokine we have previously shown to modulate TJs in human endothelial cells.Results: Human endothelial cells expressed HAVcR-1 at low levels. The location of both endogenous and forcibly expressed HAVcR-1 was at the cell-cell junction, at the region of the TJ. In this study, one of the first to examine the location and binding partners of HAVcR-1, expression of this receptor was targeted to the vicinity of intercellular junctions, via ZO-1, which further was demonstrated to be at the site of the TJ by its co-localisation with ZO-2. This was true of both endogenously and forcibly expressed protein. Moreover, HAVcR-1 was co-precipitated with the regulatory factor Rho C. Although there was no change in function of HECVHEX cells, the TJ function of the HECVHKD cells exhibited significantly reduced response to HGF over 2h (p&lt;0.01). Interestingly, there was no concurrent response in PCP.Conclusion: These results demonstrate for the first time that HAVcR-1 may have a previously undiscovered role in the regulation of TJ integrity in human endothelial cells.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2158.

Implication of a Pro-Apoptotic Protein, Prostate Apoptosis Response-4 (Par-4) in Breast Cancer

Background: Par-4, Prostate Apoptosis Response-4, is pro-apoptotic in certain cell types and has been implicated in the development and progression of solid tumours. However, the role of Par-4 in breast cancer remains unclear. The current study investigated the role played by Par-4 in breast cancer.Methods: The expression of Par-4 was examined in a breast cancer cohort using quantitative real time PCR and immunohistochemistry (IHC). The biological functions of Par-4 in breast cancer cells were tested by creating breast cancer cell lines that had differential Par-4 expression. The cell functions were examined using a variety of in vitro assays, including growth, migration and invasion. The implication of Par-4 in breast cancer was further tested in an in vivo tumour model.Results: A marked decrease of both Par-4 mRNA and protein was seen in breast tumours compared with background tissues. Par-4 staining was cytoplasmic in both mammary epithelial cells and cancer cells in the tissues. The level of Par-4 transcripts in primary tumours was decreased in the patients with poor prognosis and worse clinical outcome. The overall survival was poor in the patients with lower Par-4 transcript level, p=0.0082 compared with the patients who had higher expression. Patients with higher expression level also had longer disease free survival (133.1 months (95% CI, 121.1-145.1 months)), p=0.0597 compared with patients who had lower expression (118.4 months (95% CI, 103.2-133.5 months)). Over-expression of Par-4 in MDA-MB-231 cells (MDA-MB-231Par4exp) resulted a reduction of cell growth, migration and invasion in vitro. The invaded cell number of MDA-MB-231Par4exp was 17.9±2.5, p&lt;0.01 compared with both MDA-MB-231WT(30.8±2.6) and MDA-MB-231pEF(34.1±6.5) controls. This also led to a decreased in vivo tumour growth, in an athymic mice model.Conclusions: Taken together, decreased Par-4 expression in breast cancer correlates with poor prognosis and shorter survival. Par-4 suppresses growth, migration and invasiveness of breast cancer cells in vitro, and also inhibits in vivo tumour growth. It suggests that Par-4 plays critical roles in the progression of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6155.

Cellular Location and Expression Pattern of NHERF1 in Human Breast Cancer and the Impact of NHERF1 on the Growth of Breast Cancer Cells

BACKGROUND: The Na+/H+ exchange regulatory factor 1 (NHERF1) is an adapter protein that, when present in the cytoplasmic region, regulates trafficking and signaling of several G protein-coupled receptors (GPCRs). However, it has been recently suggested that, when located in the nucleus of cells, NHERF1 may have an oncogenic role in cancer. Recent work has shown that NHERF1 may be involved in the progression of certain solid tumours including breast cancer. The aim of the current study were: first to evaluate the spatial and cellular location of the NHEREF1 protein in mammary tissues, mammary epithelial and cancer cells, second to determine the expression pattern of the NHERF1 transcript in human breast cancer and deduce a possible association with clinical and pathological factors and, finally, to investigate the cellular impact of NHERF1 expression on breast cancer cells.MATERIALS AND METHODS: Expression of NHERF1 was examined in a cohort of breast tissue samples. The protein levels and distributions were assessed using immunohistochemical staining (IHC) and imaging analysis tools. The distribution of the NHERF1 protein in nucleus and cytoplasm was calculated using the protein staining intensity ratio between the two compartments. The transcript level was determined using quantitative real time-PCR. Constructed ribozyme transgenes were used to knock-down NHERF1 in MCF-7 cells, and the effect this had on in vitro cell growth was examined using in vitro methods.RESULTS: NHERF1 protein staining was seen in both normal epithelial cells and cancer cells in tissues. However, the staining pattern in cancer cells and normal epithelial cells was different. The protein was seen at a higher level in the nucleaus of cancer cells, as shown by a higher nuclear/cytoplasmic ratio of NHERF1 staining in breast cancer cells when compared with that in normal mammary epithelial cells (p=0.038). NHERF1 expression was increased in high grade tumours compared with low grade tumours (p=0.0016, grade-3 vs grade-1). Quantitative analysis of the NHERF1 transcript revealed a higher level expression in samples from patients with poor prognosis and that this was linked to the long term survival: mean survival for patients with high NHERF1 was 102 (55-148.8, 95%CI) months compared with 136 (126.6-145.9) months for patients with low NHERF1 transcripts. Using human breast cancer cell line, MCF7, we created NHERF1 knockdown subline. Loss of NHERF1 in the MCF-7 subline resulted in an increase in the growth rate, in vitro.CONCLUSION: This study shows that NHERF1 influences the growth of breast cancer cells. However, the effect of NHERF1 is dependent upon the levels of expression of NHERF1 in breast cancer tissues and most importantly determined by the cellular location of this protein in cancer cells.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3155.

Gene Transcripts in the Tumor Suppressor Region of Chromosome 3 (3p21)

Background:There is increasing evidence that the short arm of chromosome 3 has a tumour suppressor region that has been associated with permanent growth arrest of tumour cells. We have identified 9 closely related genes in this region (CCDC12, KLH9, KLH18, MYL3, NBEAL2, PTPN23, SCAP, SETD2, and TESSP2) located which could be possible candidates for tumour suppressor genes (TSG).Our objective was to determine, using quantitative PCR, whether the mRNA expression levels of these genes were consistent with a tumour suppressive function in human breast cancer.Methods:A total of 153 samples were analysed. The levels of transcription of all 9 genes were determined using quantitative PCR and normalized against (CK19).Transcript levels within breast cancer specimens were compared with non-cancerous breast tissue and analyzed against conventional pathological parameters and clinical outcome over a 10 year follow-up period.Results:Quantification of CCDC12, KLH9, KLH18, MYL3, NBEAL2, PTPN23, and SCAP mRNA expression after CK19 normalisation showed no statistically significant difference between malignant and normal breast tissue (p=0.23, 0.46, 0.3, 0.141, 0.8, 0.696, and 0.11 respectively). The mRNA expression of TESSP2 was higher in normal samples compared with malignant lesions (347 vs. 35, p=0.0061) but showed no significant associations with clinical outcome.The levels of SETD2 mRNA were significantly lower in malignant samples (406 vs. 17, p=0.0345) and decreased with increasing tumour stage. SETD2 expression levels were significantly lower in samples from patients who developed metastasis, local recurrence, or died from breast cancer when compared to those who were disease free for &gt; 10 years (p=0.041).Conclusion:These findings are consistent with a possible tumour suppressor function of SETD2 in human breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6139.

Transforming Acidic Coiled-Coil-Containing Protein 2 (TACC2) in Human Breast Cancer, Expression Pattern and Clinical/Prognostic Relevance

BACKGROUND: TACC2 is a member of the transforming acidic coiled-coil-containing protein family and is associated with the centrosome-spindle apparatus during cell cycling. In vivo, the TACC2 gene is expressed in various splice forms predominantly in postmitotic tissues, including heart, muscle, kidney, and brain. Recent work has shown that members of this family, including TACC2, may be involved in the progression of certain solid tumours. The aim of the current study was to identify the role of TACC2 in breast cancer and to establish if a prognostic relevance exists.MATERIALS AND METHODS: Fresh frozen primary human breast cancer tissues (n = 120) and non-neoplastic mammary tissues (n = 32) were used. The distribution and location of TACC2 was assessed using immunohistochemical staining (IHC) and imaging analysis tools. The transcript levels of TACC2 were determined using quantitative real time-PCR. The results were analyzed against the clinical, pathological and follow-up (10 years) data. Statistical analysis was by Mann-Whitney U test and Kaplan-Meier method. Shown are median transcript level.RESULTS: TACC2 protein staining was seen in both normal epithelial cells and cancer cells in mammary tissues. Increased staining of TACC2 was seen in most of the breast tumours examined when compared with normal breast tissues. Quantitative analysis of the TACC2 transcript also revealed a higher level expression in tumours compared with normal tissues (p=0.027, tumours vs normal). TACC2 expression was significantly increased in higher grade tumours compared to those in lower grade tumours (grade-3 vs grade-1, p=0.046). Using the Nottingham Prognostic Index (NPI), TACC2 transcript was significantly higher in tumours from patients with a moderate prognosis than from those with a good prognosis (p = 0.019). The expression in samples from patients with poor clinical outcome (with metastasis, recurrence and breast cancer related death) was significantly higher than that from patients who remained disease free (median (IQR) 33.8 (3.0-110.2) copies vs 6 (1.6-28.9) copies, p=0.038). This was reflected by the shorter disease-free survival for patients with high TACC2 (107 (91-122.8, 95% CI) months compared with 137 (125-150.6) months for patients with low TACC2 transcripts (p=0.019).CONCLUSION: This study shows that increased expression of TACC2 correlates with poor prognosis in patients with breast cancer. This suggests that TACC2 mediates an oncogenic effect on breast cancer cells. The findings also suggest that TACC2 may be a potential therapeutic target.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3159.

Suppressors of Cytokine Signaling and Their Role in Human Breast Cancer

BACKGROUND:Suppressors of cytokine signaling (SOCS) are important negative feedback regulators of the JAK/STAT signaling pathway, and have been recently investigated for their role in the development of different cancers. In this study, we examined the expression of SOCS 1-7 genes in normal and breast cancer tissue and correlated this with several clinico-pathological and prognostic factors.PATIENTS AND METHODS:SOCS 1-7 mRNA extraction and reverse transcription were performed on breast cancer tissue samples (n= 127) and normal background breast tissue (n= 31). Transcript levels of expression were determined using real-time PCR and analyzed against TNM stage, tumour grade and clinical outcome over a 10 year follow-up period.RESULTS:SOCS 1,4,5,6 and 7 expression decreased with increased TNM stage (TNM1 vs. TNM3 p= 0.039, TNM1 vs. TNM4 p= 0.016, TNM1 vs. TNM3 p= 0.012 and TNM1 vs. TNM3 p= 0.044 respectively). SOCS 2 and 3 expression decreased with increased Nottingham Prognostic Index (NPI) (NPI1 vs. NPI3 p=0.033 and NPI2 vs. NPI3 p=0.041 respectively). SOCS-7 expression decreased with higher tumour grade (Grade 3 vs. Grade 2 p=0.037). After a median follow up period of 10 years, we found higher levels of SOCS 1, 2 and 7 expression among those patients who remained disease-free compared to those who developed local recurrence (p= 0.0073, p= 0.021 and p= 0.039 respectively). Similarly, we found higher levels of SOCS 2, 4 and 7 expression in those who remained disease-free compared to those who developed distant recurrence (p= 0.022, p=0.024 and p= 0.033 respectively). Patients who remained disease-free had higher levels of SOCS 1 and 2 expression compared to those who died from breast cancer (p= 0.02 and p=0.033 respectively). The disease free survival (DFS) and overall survival (OS) curves showed that higher levels of SOCS 1, 3 and 7 were significant predictors of higher DFS (p=0.015, p=0.024 and p=0.03 respectively) and OS (p=0.005, p=0.013 and p= 0.035 respectively). Higher levels of SOCS 4 were significant in predicting better OS (p=0.007) but not DFS.CONCLUSIONHigher mRNA expression levels of SOCS 1, 3, 4 and 7 are significantly associated with earlier tumour stage and better clinical outcomes in human breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3157.

Impact of IL17B on Endothelial Cells and Angiogenesis

Introduction:Tumour angiogenesis plays a vital role in cancer development and spread. In the current study, IL17B was found to be unregulated in endothelial cells in response to Hepatocyte Growth Factor (HGF). IL17B shares structural similarities to IL17A, which has been previously proposed to promote angiogenesis and tumourgenicity, though currently the role of this cytokine in cancer or angiogenesis is largely unknown.Methods:HECV gene expression in response to HGF treatment was examined over a wide range of genes using micro array analysis to detect differential gene expression over the U133+2 chip. Recombinant human IL17B (rhIL17B) was subsequently used to treat human HECV endothelial cells over a range of concentrations. The impact of rhIL17B on HECV cell motility and angiogenic potential was assessed using Matrigel migration/wounding and tubule formation.Results:Micro array analysis detected a significant increase in IL17B expression in response to 4 hour treatment of HECV human endothelial cells with 40ng/ml HGF (p &lt; 0.05 vs HGF untreated HECV cells). rhIL17B negatively influenced HECV tubule formation at the higher concentrations with substantial reduction in tubule formation being seen following treatment with 250ng/ml rhIL17B. Higher concentrations of rhIL17B were also seen to reduce the capacity of HECV cells to migrate in a scratch wounding assay and significant differences in migrated distance were observed following 75 minute incubation (P &lt; 0.05 vs control untreatment group).Conclusions:Micro array analysis suggests that IL17B gene expression in the HECV human endothelial cell line can be upregulated in response to treatment with HGF. Subsequently high levels of rhIL17B were seen to negatively impact on the tubule formation and migratory capacity of this cell line. Together this data suggests that IL17B is unlikely to play a key role in the pro-angiogenic response initiated through HGF signalling but at higher concentrations may itself be able to negatively impact the angiogenic potential of the HECV endothelial cell line.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2157.

Prognostic Significance of Placenta Growth Factor (PlGF)-1 and PGF-2 Expression in Human Breast Cancer

Background: Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGf) family, a group of angiogenic growth factors important in cancer development. Over-expression of PlGF is known to be associated with pathological angiogenesis. Recently, PlGF has been shown to have 4 isoforms, -1, -2, -3 and -4. This current study examined the expression of PlGF-1 and -2 in human breast cancer and how changes in expression of these isoforms may be linked to prognosis of the disease.Materials and Methods: Breast cancer primary tumours (n=114) and matched background tissue (n=30) were processed for RNA extraction. RNA was reversed transcribed and quantified before analysis by Q-PCR. The results were expressed as copy number of transcript/50ng RNA and standardised using β-actin. Statistical analysis was carried out using student t test (mean±SD) and Mann-Whitney U test (median/IQR) where appropriate. Immunohistochemistry was also carried out on a number of matched background and tumour sections.Results: Analysis of patients with a 10 year follow-up showed that transcript levels of PlGF-1 were increased in node positive tumours when compared to node negative (104.2±52.2 versus 52.5±13.6, respectively, but this did not reach significance(p=0.34). Prognostic indicators (NPI status, TNM status and grade of tumour) were not associated with significant changes in levels of PlGF-1. Moreover, there was no difference in expression with overall ER status of tumours; however, PlGF-1 was significantly increased in ERβ positive tumours (median values ERβ-ive and ERβ+ive (14.10 vs 68.75 respectively, p=0.014). Most interestingly, there was a significant increase in PlGF-1 expression in patients with poor outcome (median values patients remaining disease-free 16.5, patients who died from breast cancer 78.2, p=0.03). In comparison, the PGF-2 isoform showed little change in expression between tumour and background samples. However, Immunohistochemistry demonstrated a marked increased in PGF-2 expression in tumour sections (staining intensity (mean±SD): Background 102.05± 46.65 vs Tumour 172.85±40.33, n=20, p=0.0001).Conclusions: We can conclude from this data that there is a differential expression of the PlGF isoforms in human breast cancer. Inappropriate expression of PlGF isoforms may play a role in human breast cancer progression.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3041.

Evaluation of the Distribution of Stem Cell Markers in Human Breast Cancer Reveals Correlation with Clinical Progression and Metastatic Disease in Ductal Carcinoma

Background: Tumour stem cell theory suggests that a small percentage of cells in a tumour harbour intrinsic characteristics making them resistant to treatment. This could explain how patients with metastatic disease show clinical relapse several months after starting treatment due to the survival of a small group of cells with unique characteristics, including the ability to give rise to a new population of cells with resistant phenotype. We examined the distribution and expression of a panel of stem cell markers in human breast cancer primary tumours.Methods: Breast cancer primary tumours (n=114) and matched background tissue (n=30) were processed for frozen sections and RNA extraction. Frozen sections from matched tissues (tumour and background) were immuno-stained with PSCA, CD44, CD49b and CD133 antibodies and staining intensity analysed by computer image analysis. RNA was reverse transcribed and quantified before analysis by Q-PCR for the stem cell markers. Results were expressed as copy numbers of transcript/50 ng RNA (standardised by GAPDH/CK19).Results: Immunohistochemical assay revealed that there was a loss of expression of PSCA in tumour sections (149.85±24.89) compared to background tissue (222.85±9.88, n=20, p&lt;0.0001). CD44 protein was expressed strongly in background endothelia and epithelia but was weaker and diffuse in tumour cells (134.5±29.89 and 187.9±21.28 respectively, p&lt;0.0001). CD133 expression was lost in tumour-associated endothelial cells with diffuse and weak staining in tumours compared to background (194.9±35.76 and 222.2±20.46 respectively, p&lt;0.006). Conversely, CD49b strongly stained in tumour and associated vessels and ducts but was weakly stained in background epithelia, albeit strongly staining background ducts and vessels (166.7±29.78 and 211.75±15.32 respectively, p&lt;0.0001). Quantitative analysis of the gene transcripts further illuminated the expression of the stem cell markers: CD44 and PSCA were reduced in patients with poor outcome (metastatic disease and death from breast cancer), with a marked reduction in ductal carcinoma, particularly with metastasis to bone although these did not reach significant difference. However, CD49b and CD133 were significantly reduced in patients with metastatic disease (0.0001±0.0002 and 3.63±3.4 respectively) compared with those remaining alive and well after 10 year follow-up (31±15, p=0.03 and 553±261, p=0.039). CD133 was also significantly reduced in patients with ductal carcinoma/bone metastasis. Conversely, CD49F was increased in patients with a poor outcome and those with ductal cancer and bone metastases.Conclusion: This is the first study to determine the distribution and expression pattern of these stem cell markers in human breast cancer. We have shown that there is a significant association between loss of expression and metastatic disease in patients with breast cancer. Such differential expression may play a part in breast cancer disease progression, and suggests that the current stem cell theory may not hold true for all cancer types.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1157.

The Role of ALCAM, Activated Leukocyte Cell Adhesion Molecule, in the Aggressive Nature of Breast Cancer Cells, a Potential Connection to Bone Metastasis

Introduction. ALCAM, activated leukocyte cell adhesion molecule, has been previously reported to be connected to the progression of certain solid tumours. In breast cancer, ALCAM has been shown to be expressed at a reduced level in aggressive tumours (King et al 2004) and is a prominent feature for tumours subsequently developed bone metastasis (Davies et al 2008). In the present study, we investigate the molecular impact of ALCAM on the biological behaviours of breast cancer cells with a particular reference to condition that is linked to bone biological environment.Methods. A mammalian ALCAM expression construct was prepared from normal mammary cDNA bank using a pEF6.V5/His vector. Anti-ALCAM transgenes were prepared based on human ALCAM mRNA structure and cloned into a mammalian expression vector. Suitable cells were transfected with either the expression construct or anti-ALCAM transgene, to create sublines that had differential expression of ALCAM. The growth, migration and invasion of the aforementioned cells, together with their parent and control cell lines were evaluated using a panel of in vitro cell models, in the presence or absence of matrix proteins prepared from human bones. Statistical analysis was Student t test or Mann-Whitney test, where appropriate.Results. Of the 12 human breast cancer lines tested, ZR-75-1 was found to be strongly positive for ALCAM expression, whereas MDA-MB-231 was negative. ZR-75-1 was therefore transfected with the anti-ALCAM transgene. After selection, a subline, ZR-751ΔALCAM was created in which ALCAM expression was knocked out. Likewise, MDA-MB-231 was transfected with ALCAM expression construct, followed by creation of new subline, MDA-MB-231ALCAMexp, a sublined that over-expressed ALCAM. MDA-MB-231ALCAMexp cells showed a marginally slower rate of growth compared with control cells. However, in the presence of bone matrix proteins, MDA-MB-231ALCAMexp showed a significantly reduced rate of growth (growth index 0.62±0.11), p&lt;0.01 vs control cells (1.06±0.15). In contrast, ZR-751ΔALCAM cells showed a faster pace of growth (1.04±0.14) compared with control cells (0.81±0.09). In an extracellular matrix based in vitro invasion assay, it was observed that MDA-MB-231ALCAMexp displayed a significantly reduced invasiveness compared with control cells (p=0.012). ZR-751ΔALCAM cells showed a significantly increased invasiveness vs its control cells (p=0.02). In an electric cell sensing based cell migration assay, we found that MDA-MB-231ALCAMexp cells showed marked reduction in migration compared with its control and parent cells. We have shown that inclusion of bone matrix proteins further reduced the migration speed of MDA-MB-231ALCAMexp cells.Conclusion. The present study provides cellular insight into the role of ALCAM in its involvement in bone metastasis of breast cancer. It is concluded that loss of ALCAM in breast cancer cells facilitates the invasive behaviour of breast cancer and highly levels of ALCAM in the cells have a suppressive role in the aggressive nature of breast cancer cells.1. Davies SR, et al, Oncol Rep., 2008, 19: 555-612. King JA et al, Breast Cancer Res., 2004, 6: R478-87

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6174.

Aberrant Expression of ARP2/3 in Breast Cancer and the Association with Disease Progression

Background: Increased motility is an important characteristics of neoplastic cells, a cell function mediated through actin polymerization. During this process, aside from creation of new branches and lengthening of pre-existing actin molecule, Actin-Related Proteins (ARP)- 2 and ARP-3 work as a complex promotes polymerization through production of new nuclei for actin polymerization. This regulation is orchestrated by other intracellular regulators including and WAVE and WASP proteins, which have been shown to be aberrant in breast cancer (1,2). In this study we determined the differential expression of ARP-2 and ARP-3 and correlated the expression with various prognostic factors.Methods: Expression of ARP-2 and ARP-3 was examined in a cohort of mammary tissues (n=33 normal breast tissue and n=127 primary breast tumor tissue samples). Transcript levels of ARP2 and ARP3 were then determined using quantitative real time PCR (Q-PCR) and protein levels were assessed using immunohistochemical (IHC) staining. Results were analyzed by Mann-Whitney U test.Results: Cytoplasmic staining for both ARP-2 and ARP-3 was noted along with strong epithelial staining as compared to stromal cells. Quantitative real time PCR (Q-PCR) data analysis showed lower expression of both ARP -2 & -3 in tumour tissue as compared to normal but without statistical significance. ARP-2 expression was significantly reduced in tumour samples from patients with poor prognosis (p=0.037) and patients who died of breast cancer (p=0.0265). Primary breast tumor tissue samples from patients classified as TNM stage 3 and 4 showed statistically significant lower expression of ARP-3 as compared to normal tissue (p= 0.019 and 0.020, respectively). ARP-3 expression was also significantly lower in patients who developed local recurrence of breast cancer (p=0.027). Using a Spearman correlation analysis, ARP-3 transcripts were find to be significantly correlated with the WAVE-2 transcript (r=0.42, p&lt;0.01).Conclusions: Breast cancer shows aberrant expression of ARP-2 and ARP-3, a pattern linked to the prognosis of the patients. ARP-3 and WAVE-2 may have an intimate interplay in this association which warrants further investigation.References1. Fernando HS et al. Expression of the WASP verprolin-homologues (WAVE members) in human breast cancer. Oncology. 2007;73:376-3832. Martin TA, et al. N-WASP is a putative tumour suppressor in breast cancer cells, in vitro and in vivo, and is associated with clinical outcome in patients with breast cancer. Clin Exp Metastasis. 2008;25:97-108

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6169.