Meta-analysis of gene expression in human pancreatic islets after in vitro expansion

Pancreatic islet transplantation as a potential cure for type 1 diabetes (T1D) cannot be scaled up due to a scarcity of human pancreas donors. In vitro expansion of beta-cells from mature human pancreatic islets provides an alternative source of insulin-producing cells. The exact nature of the expanded cells produced by diverse expansion protocols and their potential for differentiation into functional beta-cells remain elusive. We performed a large-scale meta-analysis of gene expression in human pancreatic islet cells, which were processed using three different previously described protocols for expansion and for which redifferentiation was attempted. All three expansion protocols induced dramatic changes in the expression profiles of pancreatic islets; many of these changes are shared among the three protocols. Attempts at redifferentiation of expanded cells induce a limited number of gene expression changes. Nevertheless, these fail to restore a pancreatic islet-like gene expression pattern. Comparison with a collection of public microarray datasets confirmed that expanded cells are highly comparable to mesenchymal stem cells. Genes induced in expanded cells are also enriched for targets of transcription factors important for pluripotency induction. The present data increase our understanding of the active pathways in expanded and redifferentiated islets. Knowledge of the mesenchymal stem cell potential may help development of drug therapeutics to restore beta-cell mass in T1D patients.

Pemetrexed versus gefitinib versus erlotinib in previously treated non-small cell lung cancer by retrospective analysis

e19103

Background: The standards in 2nd-line therapy with advanced non-small cell lung cancer (NSCLC) were erlotinib or pemetrexed as well as docetaxel. To evaluate the efficacies and safeties of pemetrexed, gefitinib, and erlotinib in previously treated NSCLC we analyzed the datas retrospectively. Methods: Eligible patents were 1) histologically confirmed pretreated advanced (stage IIIB or IV) NSCLC, 2) with at least one measurable lesion, 3) age over 18 years, 4) performance status (PS) 0–2, and 5) should never experience other two drugs as previous therapy. Patients of pemetrexed group received IV infusion of 500mg/m2 pemetrexed mixed with normal saline every 3 weeks with vitamin B12 and folate supplementation. Patients of gefitinib group received gefitinib 250mg PO daily and of erlotinib took erlotinib 150mg PO daily. Cycles of IV pemetrexed or taking PO drugs were continued until disease progression or unacceptable toxicity. Results: we analyzed 57 patients (pemetrexed; 20, gefitnib; 20, and erlotinib; 17). The response rates were 5.3%, 25.0%, and 12.5% (P=0.22), and the disease control rate were 5.3%, 40.0%, and 50.0% respectively (P<0.01). Median progression-free survival (PFS) of pemetrexed, gefitinib, and erlotinib were 1.7, 3.5 and 4.4 months (P<0.01) and median overall survival (OS) were 5.6, 21.8 and 21.5 months respectively (P=0.04). In subgroup analysis, patients with non-squamous carcinoma, smokers and good PS (0 or 1) showed longer PFS and OS in gefitinib and erlotinib compared with in pemetrexed. All of these agents showed mild and tolerable toxicity. Conclusions: In retrospective analysis, the patients with gefitinib or erlotinib had longer PFS and OS than pemetrexed, eventhough there was no significant difference for response rate in three group. These results have to confirm by large randomized prospective study because the sample size was small and it was not randomized.

No significant financial relationships to disclose.

TAC (docetaxel, doxorubicin, and cyclophosphamide) adjuvant chemotherapy supported by G-CSF without dose-reduction in node-positive breast cancer

e11606

Background: For node-positive breast cancer, TAC (Docetaxel-Doxorubicin-Cyclophosphamide) chemotherapy is preferred as an adjuvant treatment. However, due to its high toxicity profiles such as severe neutropenia, TAC is a lot beyond enthusiasm. G-CSF support or even prophylaxis has been recommended to help patients recover from nadir, along with some dose-reduction schedule. We tried to evaluate whether TAC with G-CSF support from day 5 can be sustained without dose reduction in women under 69-years old. Methods: After getting IRB approval, between Mar. 2005 and Oct. 2008, 61 node-positive breast cancer patients (33 - 69 years old) had underwent TAC chemotherapy as an adjuvant treatment after curative resection after getting informed consent. Total of 366 cycles (6 cycles per patient, 75–50–500 mg/m2)were completed, G-CSF support was initiated from day 5 to full neutrophil recovery. In case of neutropenia, prophylactic antibiotics (cefoperazone 2 g and tobramycin 200 mg iv) were given. Results: Among 366 cycles, not a single cycle should be delayed to recover from any hematologic shortcomings such as neutropenia, anemia or thrombocytopenia. Interval of three weeks between each cycle could be maintained. No other problem happened for any patient to stop or postpone scheduled chemotherapy. None of antibiotics except prophylaxis with cefoperazone and tobramycin was needed. Conclusions: Maximum tolerable dose of chemotherapeutic agents should be given to patients to get the best oncologic outcome to fight against cancer. It is evident that huge scale prospective clinical trials can answer this question, but we presume that node-positive breast cancer patients between in her fourth and seventh decade can stand TAC chemotherapy with G-CSF support without dose reduction as routine.

No significant financial relationships to disclose.

Effect of a synthetic peroxisome proliferator-activated receptor-gamma (PPARγ) ligand on breast cancer cells

e14638

Background: Peroxisome proliferator-activated receptor-gamma (PPARγ) ligands have been identified as a potential source of therapy for human cancers. And, it is reported that PPAR-γ ligands could serve as negative regulators of breast cancer development and progression, but their mechanism is still unknown. The purpose of this study was to determine whether the PPAR- γ ligand induces cell cycle arrest and apoptosis of MDA-MB-231(ERα-negative) and MCF-7(ERα-positive) breast cancer cell. Methods: The effect of PPAR-γ ligands on the cell viability of breast cancer cells was determined using mitochondrial tetrazolium(MTT) assay. The cell cycle distribution and apoptosis induction were evaluated by using the flow cytometry. The expression of apoptosis-related proteins were measured with Western blot analysis. Results: The treatment of MDA-MB- 231 cell with PPAR-γ ligand, troglitazone was shown to induce cell cycle G1 arrest and induction of apoptosis. Moreover, troglitazone treatment, applied in a dose-dependent manner, caused a marked decrease in phosphorylated retinoblastoma(pRb), cyclin D1, D2, D3, cyclin dependent kinase(Cdk) 2, 4, and 6 expression as well as a significant increase in Cdk inhibitor, p21 and p27. Troglitazone showed antiproliferative effect on MCF-7 cell with tamoxifen, respectively and synergically. Troglitazone and tamoxifen could induce G1 arrest and apoptosis of MCF-7 cell, through upregulation of Bax and downregulation of Bcl-2 and cyclin D1. Conclusions: PPAR-γ ligand, troglitazone induces cell cycle arrest and apoptosis of MDA-MB-231 cell and increases the sensitivity of anti-hormonal therapy in MCF-7 cell. These results suggest that troglitazone has anticancer effect on both ERα-negative and positive breast cancer cells.

No significant financial relationships to disclose.

Weight gain after adjuvant TAC (docetaxel, doxorubicin, and cyclophosphamide) chemotherapy for node-positive breast cancer

e11552

Background: Despite of its proven therapeutic efficacy, TAC (docetaxel, Doxorubicin and cyclophosphamide) regimen as an adjuvant chemotherapy has some serious adverse effects such as fluid retention and neutropenia. Even though dexamethasone is known to be given for three days to the patients having TAC chemotherapy to prevent severe fluid retention, most patients have ironically been complaining of much weight gain more than 15% increase after the use of dexamethasone. We tried to determine abbreviated use of dexamethasone is better to decrease the extent of weight gain after TAC chemotherapy. Methods: Eighty node-positive patients between Jan. 2006 and Oct. 2007 were randomly assigned either into 24-hr (group A: 10 mg dexamethasone the night before TAC, and 10 mg dexamethasone (bid) were given for the day 1) or 72-hr dexamethasone premedication (group B) only after getting informed consent since all the protocols were reviewed by IRB. We compared the incidence of severe weight gain (more than 15%) on completion of six cycles in two groups. No patient was found to have heart or kidney problem before the commencement of chemotherapy. Results: Each group was comprised of 40 patients. All patients underwent 6 cycles. Mean age of each group was 48.5 (A) and 50.3 (B) years. The incidence of severe weight gain was 47.3 % in Group A, and 78.4 % in Group B. There was no difference in the duration of recovering from weight gain in both groups (A: 6.52 months vs. B: 7.02 months). No other hematologic complications seemed different between two groups. Conclusions: Though larger scale prosepctive randomized trials should be required to get the definitive conclusion on this matter, we think that current dexamethasone premedication may aggravate weight gain than to prevent it. If shorter schedule is as much effective as longer one, abbreviated and reduced dexamethasone premedication is more helpful for patients having TAC chemotherapy.

No significant financial relationships to disclose.

Quantum phase transitions and continuous observation of spinor dynamics in an antiferromagnetic condensate

Condensates of spin-1 sodium display rich spin dynamics due to the antiferromagnetic nature of the interactions in this system. We use Faraday rotation spectroscopy to make a continuous and minimally destructive measurement of the dynamics over multiple spin oscillations on a single evolving condensate. This method provides a sharp signature to locate a magnetically tuned separatrix in phase space which depends on the net magnetization. We also observe a phase transition from a two- to a three-component condensate at a low but finite temperature using a Stern-Gerlach imaging technique. This transition should be preserved as a zero-temperature quantum phase transition.

CD4+Foxp3+ regulatory T cell expansion induced by antigen-driven interaction with intestinal epithelial cells independent of local dendritic cells

BACKGROUND

Regulatory T cells (T(regs)) have potential anti-inflammatory effects and are likely to be important in the pathogenesis of chronic inflammatory bowel disease (IBD). However, the induction and expansion of T(regs) at sites of mucosal inflammation are not yet fully understood and may involve antigen presentation by local dendritic cells (DCs) and/or intestinal epithelial cells (IECs).

METHODS

To determine the unique ways in which the gut induces or expands T(regs), a transgenic mouse model that is based on the specific expression of a model autoantigen (influenza haemagglutinin (HA)) in the intestinal epithelium (VILLIN-HA) was used. Gut-associated DCs and IECs isolated from these mice were phenotypically and functionally characterised for the potential to interact with HA-specific T(regs) in vitro and in vivo.

RESULTS

Intestinal self-antigen expression leads to peripheral expansion of antigen-specific CD4(+)Foxp3(+) T(regs). Although gut-associated DCs can induce antigen-specific CD4(+)Foxp3(+) T cell proliferation, in vivo depletion of DCs did not preclude proliferation of these cells. Interestingly, antigen presentation by primary IECs is sufficient to expand antigen-specific CD4(+)Foxp3(+) T(regs) efficiently. This is dependent on major histocompatibility complex class II, but, in contrast to DCs, is unlikely to require transforming growth factor beta and retinoic acid.

CONCLUSION

This study provides experimental evidence for a new concept in mucosal immunity: in contrast to current thinking, expansion of T(regs) can be achieved independently of local DCs through antigen-specific IEC-T cell interactions.

Ki-67 gives additional prognostic information on St Gallen 2007 and Adjuvant! Online risk categories in early breast cancer

Abstract #1086

Purpose: We sought to determine the significance of Ki-67, one of the tumor cell proliferation indexes, as a useful prognostic factor in early breast cancer.&#x2028; Patients and Methods: 1,080 consecutive patients with stage I or II breast cancer operated between 1998 and 2003 were enrolled. Patients were categorized based on the 2007 St. Gallen consensus and Adjuvant! Online. The expression of Ki-67 in the tumor was assayed using immunohistochemistry (cut-off value: 10%).&#x2028; Results: Univariate analysis revealed that tumor size, lymph node involvement, histologic grade, estrogen receptor, progesterone receptor, bcl-2, and Ki-67 (≥10%) were significant for both overall survival (OS) and distant metastasis-free survival (DFS). Of them, lymph node involvement and high Ki-67 expression were identified as independent prognostic factors for OS at multivariate analysis. The survivals of intermediate- and high-risk groups according to 2007 St Gallen consensus were further separated by Ki-67 expression level (5-yr DFS rate=93.3% vs 86.6% for Ki-67&lt;10% and ≥10%, respectively in intermediate-risk group (p=.001); 5-yr DFS rate=83.1% vs 61.5% for Ki-67&lt;10% and ≥10%, respectively in high-risk group (p=.006)). The survivals of low- and high-risk groups according to Adjuvant! Online were further separated by Ki-67 expression level [5-yr DFS rate=97.8% vs 89.5% for Ki-67&lt;10% and ≥10%, respectively in low-risk group (p=.010); 5-yr DFS rate=90.4% vs 82.6% for Ki-67&lt;10% and ≥10% in high-risk group (p=.005)).&#x2028; Conclusion: Ki-67 was an independent prognostic factor for DFS and OS in early breast cancer, and could give additional prognostic information on the risk grouping by 2007 St Gallen consensus and Adjuvant! Online.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1086.

GSTP1 promoter hypermethylation during breast cancer development

Abstract #5042

Background. Promoter hypermethylation in precursor lesions of the breast cancer may be biomarkers of cancer risk and targets for cancer chemoprevention. GSTP1 is inactivated by promotor hypermethylation in invasive breast cancers. However, little is known about epigenetic silencing of GSTP1 gene by promoter hypermethylation in precursor lesions.&#x2028; Method. To determine the significance of GSTP1 promoter hypermethylation in breast carcinogenesis, methylation status of GSTP1 gene was studied by nested methylation-specific PCR and GSTP1 expression was studied by immunohistochemistry in invasive ductal carcinoma (IDC), ductal carcinoma in situ (DCIS), usual ductal hyperplasia (UDH) and normal breast tissue.&#x2028; Results. GSTP1 promoter hypermethylation was detected in 4/24 (16.7%) of UDH, 18/49 (36.7%) of DCIS, and 14/36 (38.9%) of IDC. No hypermethylation was detected in normal breast tissues. GSTP1 promoter hypermethylation was found to be progressively elevated during breast carcinogenesis (P &lt; 0.01). GSTP1 promoter hypermethylation was associated with loss of GSTP1 expression (P &lt; 0.01 for UDH, P &lt; 0.001 for DCIS and IDC).&#x2028; Conclusion. Our results suggest that GSTP1 promoter hypermethylation is an early event in breast carcinogenesis and appears to functionally silence GSTP1 expression. GSTP1 promoter hypermethylation in the precursor lesions of breast cancer may be used as a target for cancer chemoprevention.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5042.

Induction of cell cycle arrest and apoptosis in breast cancer cells by troglitazone, a peroxisome proliferator-activated receptor-gamma (PPAR-γ) ligand

Abstract #5034

Background: Peroxisome proliferator-activated receptor-gamma(PPAR-γ) ligands inhibit cell proliferation and induce apoptosis in cancer cells. And, it is reported that PPAR-γ ligands could serve as negative regulators of breast cancer development and progression, but their mechanism is still unknown. Here we wished to determine whether the PPAR-γ ligand induces cell cycle arrest and apoptosis of MDA-MB-231(ERα-negative) and MCF-7(ERα-positive) breast cancer cell.&#x2028; Methods: The effect of PPAR-γ ligands on the cell viability of breast cancer cells was determined using mitochondrial tetrazolium(MTT) assay. The cell cycle distribution and apoptosis induction were evaluated by using the flow cytometry. The expression of apoptosis-related proteins were measured with Western blot analysis. Statistical analysis was performed using Student's t test, and p&lt;0.05 was considered significant.&#x2028; Results: The treatment of MDA-MB-231 cell with PPAR-γ ligand, troglitazone was shown to induce cell cycle G1 arrest and induction of apoptosis. Moreover, troglitazone treatment, applied in a dose-dependent manner, caused a marked decrease in phosphorylated retinoblastoma(pRb), cyclin D1, D2, D3, cyclin dependent kinase(Cdk) 2, 4, and 6 expression as well as a significant increase in Cdk inhibitor, p21 and p27. Troglitazone showed antiproliferative effect on MCF-7 cell with tamoxifen, respectively and synergically. Troglitazone and tamoxifen could induce G1 arrest and apoptosis of MCF-7 cell, through upregulation of Bax and downregulation of Bcl-2 and cyclin D1.&#x2028; Conclusion: PPAR-γ ligand, troglitazone induces cell cycle arrest and apoptosis of MDA-MB-231 cell and increases the sensitivity of anti-hormonal therapy in MCF-7 cell. These results suggest that troglitazone has anticancer effect on both ERα-negative and positive breast cancer cells.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5034.

Demulsification of oil-rich emulsion from enzyme-assisted aqueous extraction of extruded soybean flakes

Extraction of soybean oil from flaked and extruded soybeans using enzyme-assisted aqueous extraction processing (EAEP) is a promising alternative to conventional hexane extraction. The efficiencies of four proteases releasing oil from extruded material were compared. Protex 51FP, Protex 6L and Protex 7L each extracted 90% of the total oil available while Protex 50FP gave similar extraction yield as the control (without enzyme treatment). During EAEP, however, a stable emulsion forms that must be broken in order to recover free soybean oil. The potential of various proteases and phospholipases to destabilize the emulsion was determined. Two enzymes, a phospholipase A2 (LysoMax) and a protease (Protex 51FP) were selected to determine the effect of enzyme concentration on demulsification. Although at a 2% concentration (w/w, enzyme/(cream+free oil)), each enzyme tested was effective in totally destabilizing the cream; the protease released significantly more free oil than did the phospholipase at concentrations less than 2%. At 0.2% concentration, 88 and 48% of free oil were obtained with the protease and phospholipase, respectively. Reducing the pH of the cream also destabilized the cream with maximum demulsification at the isoelectric point of soy proteins. These results provide destabilization strategies for the oil-rich emulsion formed during aqueous extraction processing of extruded flakes and significantly contribute to the development of this environmentally-friendly technology.

Soluble manganese removal by porous media filtration

Filtration experiments were conducted to investigate soluble manganese removal in granular media filtration; sand, manganese oxide coated sand (MOCS), sand + MOCS (1:1) and granular activated carbon (GAC) were used as filter media. Manganese removal, manganese oxide accumulation, turbidity removal, and regeneration of MOCS under various conditions were examined. Soluble manganese removal by the MOCS column was rapid and efficient; most of the removal happened at the top (e.g. 5 cm) of the filter. When filter influent with an average manganese concentration of 0.204 mg l(-1) was fed through the filter columns, the sand + MOCS and MOCS columns removed 98.9% and 99.2% of manganese, respectively. However, manganese removal in sand and the GAC columns was not significant during the initial stage of filtration, but after eight months of filter run they could remove 99% and 35% of manganese, respectively. It was revealed that partial replacement of sand with MOCS showed comparable manganese removal to that of the MOCS filter media.

Electroactive polymer actuator with high response speed through anisotropic surface roughening by plasma etching

Plasma etching was performed to improve displacement and response speed of IPMC actuator through homogeneous roughening and anisotropic surface treatment. We found that the anisotropic surface treatment by plasma etching of Nafion in the pre-treatment process gave the response speed and displacement of resulting IPMC which was 2 times faster and 1.5 times larger than those manufactured by the sandblasting, respectively.