Isolation and characterization of a highly metastatic hybrid cell line generated between estrogen receptor (ER) negative and ER positive breast cancer cells in mouse bone marrow

Abstract #2053

Background: Breast cancer cells in a patient are heterogeneous. How the presence of these heterogeneous cancer cells may contribute to cancer progression is not clear. Experimental evidence indicates that soluble factors produced by aggressive cancer cells may generate metastasis niches for less aggressive cancer cells. In this study, we sought to determine how a growing orthotopic tumor formed by an aggressive ER negative breast cancer cell line might affect the metastatic potential of a less aggressive ER positive breast cancer cell line.
 Methods and Results: Five-week-old female nude mice were injected orthotopically with metastasis-competent ER negative human breast cancer MDA-MB-231/GFP/Neo cells. After three weeks, metastasis-incompetent human breast cancer ER positive ZR-75-1/GFP/puro cells were inoculated into these mice via intra-cardiac (IC) route and puromycin resistant metastatic ZR-75-1/GFP/puro cells were flushed out of the bone marrow of one mouse and established as a variant cell line called B6. B6 cells have both estrogen-dependent and -independent cells when they were orthotopically injected into female nude mice with or without estrogen supplementation. The cells isolated from an estrogen-dependent tumor were called B6TE and the cells isolated from an estrogen-independent tumor were called B6TC. Further characterization revealed that B6TC cell was more tumorigenic without estrogen supplementation and has a unique metastatic property. More interestingly, B6TC cell was resistant to both puromycin and G418 suggesting it was derived from the fusion of MDA-MB-231/GFP/Neo and ZR-75-1/GFP/puro in the mouse bone marrow. When compared with parental MDA-MB-231/GFP/Neo, the B6TC cells were found to be more metastatic to lung and bone after IC inoculation as detected by GFP imaging, with significant development of paraplegia in the hind limbs after four weeks. More significantly, B6TC mice also developed metastases to brain, which was not observed in the MDA-MB-231/GFP/Neo group. B6TC cell has a low expression of ER alpha and CD24, and high expression of p-ERK, CD44, ALDH. It also expresses vimentin, CXCR4 and Integrin-β1. Its growth is refractory to the anti-estrogens, raloxifene and tamoxifen.
 Conclusion: Our study indicates that B6 cells generated in the bone marrow were a heterogeneous population of ER positive and ER negative cells with marked differences in their proliferative potential and malignancy. The low ER-expressing B6TC is a novel hybrid cell line generated spontaneously in a metastatic site, which has propensity to metastasize to brain in addition to lung and bone. The expression of CD44 and ALDH indicates that it has stem cell-like features. Further characterization and molecular profiling is underway to reveal the novel biomarkers. This cell line should be a useful model for the investigation of the molecular mechanism of brain metastasis and the therapeutic strategies for the treatment of metastatic breast cancer resistant to anti-estrogens.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2053.

STAT1 and STAT3 synergistically suppress EGF-induced MMP-9 activity in SKBR3 human breast cancer cell line

Abstract #2064

Background: EGF is a cytokine associated with cell proliferation, migration, and tumor invasion through EGFR activation in various cancer cells. EGFR activates its downstream molecules such as protein kinase C-δ, ERK, PI3-kinase, STAT-3. It has been shown that EGFR induces matrix metalloproteinase-9 (MMP-9), leading to invasion and migration of cancer cells. However, it has not been fully elucidated the roles of STAT-1 and STAT-3 in breast cancer cells. We investigated the regulatory mechanism of STAT-1 and STAT-3 on EGF-induced MMP-9 activity in SKBR3 cells.
 Material and Methods: EGF-induced MMP-9 activity regarding to ERK, JNK, PI-3 kinase and STAT-3 were evaluated by Western blot. Then, we transfected SKBR-3 cells with adenoviral vectors containing STAT-1 and STAT-3 to make SKBR-3 cells overexpressing each gene. We also treated SKBR-3 cells with STAT-3 siRNA. Overexpression and silencing of genes were identified with Western blot. With the treatment of EGF, MMP-9 activity was measured with gelatinase Zymography.
 Results: We confirmed that EGF increases MMP-9 activity and induces the phosphorylation of ERK, JNK, PI-3 kinase and STAT-3 in dose-dependent manner. We found that EGF-induced MMP-9 activity was significantly decreased by MEK1/2 inhibitor, UO126, and PI3-kinase inhibitor, LY294002, respectively, but not by JNK inhibitor, SP600125. In contrast to previous study, EGF-induced MMP-9 activity was inhibited by STAT-3 overexpression. We also found that it was increased by STAT-3 siRNA transfection. Moreover, we found that STAT-1 and STAT-3 co-overexpression synergistically decreased EGF-induced MMP-9 activity in STAT-1 and STAT-3 co-overexpressing SKBR-3 cells.
 Discussion: We demonstrated that EGF-induced STAT-3 activation suppresses tumor invasion through down-regulation of MMP-9 in SKBR-3 cells. Moreover, we found that there is a synergistic relationship between STAT-1 and STAT-3, inhibiting EGF-induced MMP-9 activity.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2064.

Evaluation of response to neoadjuvant chemotherapy in primary breast cancer using PET

Abstract #4019

Purpose
 To estimate the usefulness of PET scan to assess the response of neoadjuvant chemotherapy, PET scan results were compared with conventional imaging modalities(US and MRI).
 Patients and Methods
 Fourty-one patients undergoing neoadjuvant chemotherapy between December 2004 and March 2008 were included. PET scan was performed before and after chemotherapy. Pathologic results were classified into two groups; pathological complete response(pCR) and non-pCR. Clinical responses were assessed with the results of imaging modalities such as post-chemotherapy size or pSUV(postTx), size difference between treatment(delta) and reduction rate(RR) of size or pSUV, and they are compared with postoperative pathologic results.
 Results
 7 out of 41 patients (17.1%) had pCR. The results of US shows that postTx size (1.7±1.5cm) of pCR was not dfferent from those of non-pCR (3.6±3.0cm), and the delta (3.1±1.9cm) and RR (67.7±29.1%) of pCR were higher than those of non-pCR (1.3±1.3cm, 31.0±25.4%), respectively. As a result of MRI, postTx size, delta, RR of pCR was differ from those of non-pCR (1.0±1.7cm vs 2.8±1.7cm p<0.05; 4.5±1.0cm vs 2.3±1.8cm, p<0.05; 88.0±20.8% vs 44.6±24.7%, p<0.01). In PET scan, only postTx pSUV of pCR was differ from that of non-pCR (1.4±1.3 vs 5.3±8.3cm, p<0.05). As a result of receiver operating characteristic curve analyses for the prediction of pathological response of breast cancer, area under curve values (95% confidence interval) of US, MRI, PET for delta were 0.83(0.69∼0.98), 0.91(0.80∼1.01), 0.62(0.38∼0.86), and those of RR were 0.80(0.60∼0.99), 0.90(0.77∼1.02), 0.72(0.47∼0.96), respectively
 Conclusions
 We suggest that MRI is useful method to evaluate the response of neoadjuvant chemotherapy. Although PET scan shows less effective for evaluating the response of chemotherapy than MRI, PET scan with the ability to detect the distant metastatic lesions may be helpful to decide the proper management plans for advanced breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4019.

A fully flexible stimulator using 65 nm CMOS process for 1024-electrode epi-retinal prosthesis

This paper presents a fully flexible stimulator using 65 nm CMOS process for a 1024-electrode epi-retinal prosthesis. The stimulator can select any number of electrodes at any time and also supports both mono-polar and multi-polar stimulation. Furthermore, the stimulator supports a wide range of stimulus parameters. A novel feature is that the electrode driver operates in an alternately pull-push manner, which helps reduce headroom voltage while guaranteeing charge balance at the active electrode. The use of positive supplies instead of both positive and negative supplies simplifies CMOS circuit design. The current distribution between two nearby simultaneously active electrode groups was investigated and measurement result showed a maximum current crosstalk of 8%.

Antithrombotic therapy in children with venous thromboembolism

Antithrombotic therapy has recently become more frequent for the treatment of venous thromboembolism (VTE) in the paediatric population. This can be explained by the increased awareness of morbidities and mortalities of VTE in children, as well as the improved survival rate of children with various kinds of serious illnesses. Considering the large number of years a child is expected to survive, associated morbidities such as postthrombotic syndrome and risk of recurrence can significantly impact on the quality of life in children. Therefore, timely diagnosis, evidence-based treatment and prophylaxis strategies are critical to avoid such complications. This review summarizes the current literature about the antithrombotic treatment for VTE in infants and children. It guides the paediatric medical care provider for making a logical and justifiable decision.

Copeptin immunoreactivity and calcium mobilisation in hypothalamic neurones of the rat

Copeptin is cleaved from the C-terminus of vasopressin (VP) prohormone. Immunohistochemical studies have revealed intense copeptin-immunoreactivity (irCOPT) in neurones of the rat hypothalamic nuclei, including paraventricular, supraoptic, suprachiasmatic, periventricular, and accessory secretory. Varicose cell processes emanated from irCOPT neurones, some of which projected caudally and traversed the internal layer of the median eminence, and terminated in the posterior pituitary. Double-labelling hypothalamic sections with copeptin antiserum and VP or oxytocin antiserum revealed an extensive overlapping of irCOPT and irVP neurones. The biological activity of human synthetic nonglycosylated copeptin or VP was evaluated in vivo and in vitro. Copeptin (1, 10, and 20 nmol/kg) injected i.v. caused no significant changes in the mean arterial pressure (MAP) and heart rate of urethane-anaesthetised rats. VP (0.1 nmol/kg) increased MAP, which was accompanied by a small decrease of the heart rate. The ratiometric fluorescence method was employed to assess changes in intracellular Ca2+ concentrations [Ca2+](i) which served as an index of the biological activity of peptides. VP (1 microM) markedly increased [Ca2+](i) of rat hypothalamic neurones or vascular smooth muscle cells, whereas copeptin (100 nm to 1 microM) caused a low amplitude, sustained increase of [Ca2+](i) in a population of hypothalamic neurones, but not in any of the vascular smooth muscle cells tested. The results obtained demonstrate that copeptin is expressed in VP neurones and that the peptide in the concentrations tested, although causing little or no detectable changes of blood pressure and heart rate in anaesthetised rats nor changes in [Ca2+](i) of cultured aortic smooth muscle cells, increases [Ca2+](i) in a small population (< 2%) of hypothalamic neurones tested, indicating that copeptin is biologically active in mammalian neurones.

A combined parabolic-integral equation approach to the acoustic simulation of vibro-acoustic imaging

This paper aims to model ultrasound vibro-acoustography to improve our understanding of the underlying physics of the technique thus facilitating the collection of better images. Ultrasound vibro-acoustography is a novel imaging technique combining the resolution of high-frequency imaging with the clean (speckle-free) images obtained with lower frequency techniques. The challenge in modeling such an experiment is in the variety of scales important to the final image. In contrast to other approaches for modeling such problems, we break the experiment into three parts: high-frequency propagation, non-linear interaction and the propagation of the low-frequency acoustic emission. We then apply different modeling strategies to each part. For the high-frequency propagation we choose a parabolic approximation as the field has a strong preferred direction and small propagation angles. The non-linear interaction is calculated directly with Fourier methods for computing derivatives. Because of the low-frequency omnidirectional nature of the acoustic emission field and the piecewise constant medium we model the low-frequency field with a surface integral approach. We use our model to compare with experimental data and to visualize the relevant fields at points in the experiment where laboratory data is difficult to collect, in particular the source of the low-frequency field. To simulate experimental conditions we perform the simulations with the two frequencies 3 and 3.05 MHz with an inclusion of varying velocity submerged in water.

Detection of periodontal bone loss using digital intraoral and cone beam computed tomography images: an in vitro assessment of bony and/or infrabony defects

OBJECTIVES

To explore the diagnostic values of digital intraoral radiography and cone beam CT (CBCT) in the determination of periodontal bone loss, infrabony craters and furcation involvements.

METHODS

Accuracy assessment of the imaging modalities was conducted through bone level measurements, infrabony crater and furcation involvement classifications. For CBCT, images were obtained at 120 kV and 23.87 mAs, and observations were made on a 5.2 mm panoramic reconstruction view and on 0.4 mm thick cross-sectional slices. Intraoral radiographs of a size 2 charge-coupled device (CCD) sensor were obtained using the paralleling technique, at 60 kV (DC) and 0.28 mAs exposure. 71 human cadaver and dry skull bony defects were measured and evaluated by 3 observers. Comparison was made with the gold standard.

RESULTS

The mean error (gold standard deviation) of bone level measurements was 0.56 mm for intraoral radiography and 0.47 mm for the CBCT panoramic 5.2 mm reconstruction view. There were no significant differences (P = 0.165) between the two methods. However, on 0.4 mm thick cross-sections, the mean error was 0.29 mm and the Wilcoxon signed-rank test indicated a significant difference when compared with the CCD (P = 0.006). The detection of crater and furcation involvements failed in 29% and 44% for the CCD, respectively, in contrast to 100% detectability for both defects with CBCT.

CONCLUSIONS

CBCT on the panoramic 5.2 mm reconstruction view allowed comparable measurements of periodontal bone levels and defects as with intraoral radiography. CBCT with 0.4 mm thick cross-sections demonstrated values closer to the gold standard, indicating more accurate assessment of periodontal bone loss. Further research is needed to explore these results in vivo and to determine the use of CBCT in periodontal diagnosis.

Clinical trial: effect of active lactic acid bacteria on mucosal barrier function in patients with diarrhoea-predominant irritable bowel syndrome

BACKGROUND

The intestinal permeability is increased in patients with diarrhoea-predominant irritable bowel syndrome (D-IBS).

AIM

To determine the possible efficacy of lactic acid bacteria on the increased intestinal permeability in D-IBS.

METHODS

Treatment was employed for 4 weeks in a randomized single blind placebo controlled study with 30 D-IBS patients. Patients were given either probiotic fermented milk (Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus acidophilus and Bifidobacterium Longum) or milk beverage containing no bacteria. The clinical symptoms were scored and intestinal permeability was measured by a triple sugar test before and after treatment.

RESULTS

Small bowel permeability was measured as the ratio of lactulose and mannitol recovery and colonic permeability was measured as the total mass of sucralose excretion (mg). After probiotics treatment, small bowel permeability decreased significantly from 0.038 (0.024) at baseline to 0.023 (0.020) (P = 0.004), the proportion of patients with increased small bowel permeability was lower than baseline (28.6% vs. 64.3%, P = 0.023). However, colonic permeability improved neither in the probiotics group nor in the placebo group at week 4. Treatment with probiotics significantly decreased the mean global IBS scores compared with the baseline scores (9.62 +/- 1.05 vs. 7.64 +/- 1.24, P < 0.001).

CONCLUSION

Short-term active lactic acid bacteria treatment for D-IBS improved mucosal barrier function.

Linkage mapping of five genes on SSC12 in a Berkshire × Yorkshire cross (Brief report)

Abstract. three-generation family of pig was generated by an intercross between animals of two Berkshire grand sires and nine Yorkshire grand dams (BY), and a total of 525 F2 offspring were produced. The initial genome scan analysis identified suggestive quantitative trait loci (QTL) for fat traits on chromosome 12 (SSC12) (MALEK et al., 2001). Animals that were homozygous for Berkshire alleles had relatively less back fat than those with Yorkshire alleles, and heterozygotes were fattest for these QTL. The objective of this study was to further characterize these SSC12 QTL by mapping five additional genes (PSME3, GRB7, MAC30, RPS6KB1 and TAX1BP3) in the BY family and see if they were associated with fatness traits.

Magnetic PECA nanoparticles as drug carriers for targeted delivery: Synthesis and release characteristics

Magnetic poly(ethyl-2-cyanoacrylate) (PECA) nanoparticles containing anti-cancer drugs (Cisplatin and Gemcitabine) were prepared by inter-facial polymerization. The spherical nanoparticles (d = 250 +/- 15 nm) with smooth surfaces and moderately uniform size distributions were obtained. The amount of magnetite encapsulated inside the polymer matrix was increased up to 14.26% (w/w) by controlling the initial weight ratio of monomer/magnetite. It was found that the amount of Cisplatin encapsulated in the magnetic nanoparticle is much higher than that of Gemcitabine because Cisplatin (hydrophobic) is highly soluble in the oil phase and encapsulated easier inside nanoparticles compared to Gemcitabine (hydrophilic). The presence of magnetite and its super-paramagnetic characteristic were confirmed by FTIR spectra and VSM. In-vitro experiments of drug release and magnetic mobility under external magnetic field demonstrated that magnetic poly(ethyl-2-cyanoacrylate) (PECA) nanoparticles can be a highly versatile magnetic drug carrier with sustained release behaviour and sufficient magnetic susceptibility.

MR imaging assessment of temporomandibular joint soft tissue injuries in dislocated and nondislocated mandibular condylar fractures

BACKGROUND AND PURPOSE

Evaluation of temporomandibular joint (TMJ) soft tissue injuries after condylar fractures remains a challenge with use of conventional radiography and CT. The aim of this study was to explore MR imaging in the assessment of TMJ soft tissue injuries after condylar fractures.

MATERIALS AND METHODS

Eighty subjects (118 TMJs) with condylar fractures were examined with sagittal and coronal MR imaging. Proton attenuation and T2-weighted sequences were the key sequences in our imaging protocol. All of the condylar fractures were classified into condylar fractures with dislocation (group 1, 108 TMJs) and without dislocation (group 2, 10 TMJs).

RESULTS

MR imaging demonstrated the following TMJ soft tissue injuries: 1) disk displacements (91.5%, 105 [97.2%] in group 1 and 3 [30%] in group 2; P < .01). Almost all disk displacements in group 1 were in the anteroinferior direction; 2) abnormal signal intensities of retrodiskal tissues (87.3%, 98 [88.3%] in group 1 and 5 [50%] in group 2; P < .05); 3) joint effusion (85.6%, 95 [88%] in group 1 and 6 [60%] in group 2; P > .05); 4) abnormal inferoposterior attachments of disks (87.3%, 96 [88.9%] in group 1 and 7 [70%] in group 2; P > .05) and joint capsules (85.6%, 94 [87%] in group 1 and 7 [70%] in group 2; P > .05).

CONCLUSIONS

There were significant differences of disk displacement and signal intensities of retrodiskal tissues between both fractures. Most dislocated condylar fractures were characterized with anteroinferior disk displacements along with the fractured fragments. MR imaging could provide additional information of TMJ soft tissue injuries after condylar fractures.

Cytotoxic and Topographical Properties of 6-Arylidene-2-dimethylaminomethylcyclohexanone Hydrochlorides and Related Compounds

A number of 2-arylidenecyclohexanones (1a-h) were converted into the corresponding Mannich bases (2a-h) and (3a,f). Evaluation against murine L1210 cells as well as human Molt 4/C8 and CEM T-lymphocytes revealed the marked cytotoxicity of the Mannich bases and also the fact that almost invariably these compounds were more potent than the precursor enones (1a-h). Further evaluation of most of the Mannich bases towards a panel of nearly 60 human tumour cell lines confirmed their utility as potent cytotoxins. In this assay, the compounds showed growth-inhibiting properties greater than the anticancer alkylator melphalan. QSAR studies revealed that in some cell lines compounds possessing small electron-attracting aryl substituents showed the greatest potencies. Molecular modeling and X-ray crystallography demonstrated that various interatomic distances and torsion angles correlated with cytotoxicity. A representative compound (2a) demonstrated weak inhibiting properties towards human N-myristoyltransferase and stimulated a tyrosine protein kinase. A single dose of 100 mg/kg of most of the compounds did not prove to be lethal in mice.