The Diagnostic Value of Ultrasound Elastography in Patients with Hepatitis B Virus Infection: A Prospective Study

The aim of this prospective study was to investigate the diagnostic value of ultrasound elastography for evaluating liver stiffness measurement (LSM) in 74 patients with hepatitis B virus (HBV) infection, treated with telbivudine (22 with chronic HBV infection, 32 with compensated cirrhosis and 20 with decompensated cirrhosis). Each patient underwent ultrasound elastography measurements and serum liver marker assays before and after 6 months' treatment with 600 mg telbivudine, orally, once daily. In the 22 patients with chronic HBV infection, LSM values measured by ultrasound elastography decreased significantly following the treatment period compared with baseline. The LSM values were significantly higher in the 20 patients with decompensated cirrhosis than in the 32 patients with compensated cirrhosis after treatment. Significant decreases in serum hepatic fibrosis indices occurred in all patients following treatment. The correlation between fibrosis index, hyaluronic acid level and LSM was statistically significant in all patients, whereas the correlation between alanine aminotransferase and LSM was not. The findings suggest that liver stiffness in patients with HBV can be measured simply with ultrasound elastography and that it is reduced within 6 months by treatment with telbivudine. The main adverse events noted during the study period were that creatine kinase levels were increased in seven patients and that seven patients had influenza-like symptoms.

An efficient magneto-optical trap of metastable krypton atoms

We report a magneto-optical trap of metastable krypton atoms with a trap loading rate of 3×10(11) atoms/s and a trap capture efficiency of 3×10(-5). The system starts with an atomic beam of metastable krypton produced in a liquid-nitrogen cooled, radio-frequency driven discharge. The metastable beam flux emerging from the discharge is 1.5×10(14) atoms/s/sr. The flux in the forward direction is enhanced by a factor of 156 with transverse laser cooling. The atoms are then slowed inside a Zeeman slower before captured by a magneto-optic trap. The trap efficiency can be further improved, possibly to the 10(-2) level, by gas recirculation. Such an atom trap is useful in trace analysis applications where available sample size is limited.

Cardiac myosin heavy chain gene regulation by thyroid hormone involves altered histone modifications

The antithetical regulation of cardiac α- and β-myosin heavy chain (MHC) genes by thyroid hormone (T(3)) is not well understood but appears to involve thyroid hormone interaction with its nuclear receptor and MHC promoters as well as cis-acting noncoding regulatory RNA (ncRNA). Both of these phenomena involve epigenetic regulations. This study investigated the extent that altered thyroid state induces histone modifications in the chromatin associated with the cardiac MHC genes. We hypothesized that specific epigenetic events could be identified and linked to cardiac MHC gene switching in response to a hypothyroid or hyperthyroid state. A hypothyroid state was induced in rats by propylthiouracil treatment (PTU), whereas a hyperthyroid (T(3)) was induced by T(3) treatment. The left ventricle was analyzed after 7 days for MHC pre-mRNA expression, and the chromatin was assessed for enrichment in specific histone modifications using chromatin immunoprecipitation quantitative PCR assays. At both the α-MHC promoter and the intergenic region, the enrichment in acetyl histone H3 at K9/14 (H3K9/14ac) and trimethyl histone H3 at K4 (H3K4me3) changed in a similar fashion. They were both decreased with PTU treatment but did not change under T(3), except at a location situated 5' to the antisense intergenic transcription start site. These same marks varied differently on the β-MHC promoter. For example, H3K4me3 enrichment correlated with the β-promoter activity in PTU and T(3) groups, whereas H3K9/14ac was repressed in the T(3) group but did not change under PTU. Histone H3K9me was enriched in chromatin of both the intergenic and α-MHC promoters in the PTU group, whereas histone H4K20me1 was enriched in chromatin of β-MHC promoter in the normal control and T(3) groups. Collectively, these findings provide evidence that specific epigenetic phenomena modulate MHC gene expression in altered thyroid states.

Protein tyrosine phosphatase 1B gene polymorphisms and essential hypertension: a case-control study in Chinese population

BACKGROUND

Protein tyrosine phosphatase (PTP)- 1B, encoded by the PTPN1 gene, negatively regulates insulin signaling by dephosphorylating the phosphotyrosine residues of the insulin receptor kinase activation segment. Several rare single nucleotide polymorphisms (SNP) have been linked to diseases accompanying insulin resistance such as Type 2 diabetes, obesity, and dyslipidemia in different populations.

AIM

To investigate whether PTP-1B SNP are associated with hypertension and hypertension-related metabolic traits in Chinese subjects.

MATERIALS AND METHODS

A total of 239 Chinese patients with hypertension and 141 non-hypertensive subjects were screened. The genotypes of PTP-1B gene polymorphisms were determined by PCR-restriction fragment length polymorphism methods.

RESULTS

The case-control study showed associations between the frequencies of T allelic g54281 T>A and A allele of I5/37C>A and hypertension (p<0.0001, p=0.0371, respectively). In addition, significant associations were observed between the IVS6+G82A polymorphism and waist circumference, total cholesterol, and LDL-cholesterol levels in hypertensive patients (p=0.0005 approximately 0.0260). And g54281 T allele was associated with higher plasma triglyceride (p=0.0390) and LDL-cholesterol concentration (p=0.0141), while g58585 T>C was associated with body mass index (BMI) (p=0.0308), waist circumference (p=0.0216), and homeostasis model assessment of insulin resistance (p=0.047). Multivariate logistic regression analysis showed that T allele carriers of g54281T>A and A allele carriers of I5/37C>A had higher risks of hypertension independent of age, gender, BMI, glucose levels, and lipids profiles [odds ratio (OR): 1.79, 95% confidence interval (CI): 1.09- 2.96, p=0.02; OR: 1.66, 95% CI: 1.13-2.44, p=0.01, respectively].

CONCLUSIONS

PTP-1B polymorphisms contribute to pathogenesis of hypertension in Chinese subjects and PTP-1B SNP may be involved in the development of several features including dyslipidemia and obesity in hypertensive subjects.

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.

Ammonia and proinflammatory cytokines modify expression of genes coding for astrocytic proteins implicated in brain edema in acute liver failure

There is evidence to suggest that, in acute liver failure (ALF), brain ammonia and proinflammatory cytokines may act synergistically to cause brain edema and its complications (intracranial hypertension, brain herniation). However, the molecular mechanisms involved remain to be established. In order to address this issue, semi-quantitative RT-PCR was used to measure the expression of genes coding for astrocytic proteins with an established role in cell volume regulation in cerebral cortical astrocytes exposed to toxic agents previously identified in experimental and clinical ALF. Such agents include ammonia, the proinflammatory cytokine interleukin-1beta (IL-1beta) and combinations of the two. Exposure of cultured astrocytes to recombinant IL-1beta (but not ammonia) resulted in increased expression of aquaporin-4 (AQP-4). Both ammonia and proinflammatory mediators led to decreased expression of glial fibrillary acidic protein (GFAP), a cytoskeletal protein, but these effects were not additive. On the other hand, heme oxygenase-1 (HO-1) and inducible nitric oxide synthase (iNOS) expression were significantly increased by exposure to both ammonia and proinflammatory mediators and although modest, these effects were additive suggestive of a synergistic mechanism. These findings suggest that worsening of brain edema and its complications in ALF due to proinflammatory mechanisms may result from exacerbation of oxidative stress-related mechanisms rather than upregulation of AQP-4 or decreases in expression of the astrocytic structural protein GFAP.

Portacaval anastomosis-induced hyperammonemia does not lead to oxidative stress

Ammonia is neurotoxic and believed to play a major role in the pathogenesis of hepatic encephalopathy (HE). It has been demonstrated, in vitro and in vivo, that acute and high ammonia treatment induces oxidative stress. Reactive oxygen species (ROS) are highly reactive and can lead to oxidization of proteins resulting in protein damage. The present study was aimed to assess oxidative status of proteins in plasma and brain (frontal cortex) of rats with 4-week portacaval anastomosis (PCA). Markers of oxidative stress, 4-hydroxy-2-nonenal (HNE) and carbonylation were evaluated by immunoblotting in plasma and frontal cortex. Western blot analysis did not demonstrate a significant difference in either HNE-linked or carbonyl derivatives on proteins between PCA and sham-operated control rats in both plasma and frontal cortex. The present study suggests PCA-induced hyperammonemia does not lead to systemic or central oxidative stress.

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.