In previous studies, human dental pulp stem cells (hDPSCs) were mainly isolated from adults. In this manuscript, we tried characterization of hDPSCs isolated from an earlier developmental stage to evaluate potential usage of these cells for tissue regenerative therapy. hDPSCs isolated at the crown-completed stage showed a higher proliferation rate than those isolated at the later stage. When the cells from either group were cultured in medium promoting differentiation towards cells of the osteo/odontoblastic lineage, both became alkaline phosphatase positive, produced calcified matrix, and were also capable of forming dentin-like matrix on scaffolds in vivo. However, during long-term passage, these cells underwent a change in morphology and lost their differentiation ability. The results of a DNA array experiment showed that the expression of a number of genes, such as WNT16, was markedly changed with increasing number of passages, which might have caused the loss of their characteristics as hDPSCs.
Characterization of dental pulp stem cells of human tooth germs.
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View SamplesWe have generated a MCF-7 Tet-On model system for inducible nuclear expression of intracellular domain of LRP1b using the pTRE-Tight vector system (Clontech Takara, Ohtsu, Japan).
No associated publication
Specimen part, Cell line
View SamplesNon-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations have shown a dramatic response to EGFR inhibitors (EGFR-TKI). EGFR T790M mutation and MET amplification have been recognized as major mechanisms of acquired resistance to EGFR-TKI. Therefore, MET inhibitors have recently been used in NSCLC patients in clinical trials. In this study, we tried to identify the mechanism of acquired resistance to MET inhibitor. We analyzed the antitumor effects of two MET inhibitors, PHA-665752 and crizotinib, in 10 NSCLC cell lines. EBC1 cells with MET amplification were the only cells that were sensitive to both MET inhibitors. We established PHA-665752-resistant EBC1 cells, namely EBC1-R cells. EBC1-R cells showed overexpression of ATP-binding cassette sub-family B member 1 (ABCB1) as well as phosphorylation of MET. EBC1-R cells grew as cell spheres that exhibited cancer stem cell-like (CSC) properties and epithelial mesenchymal transition (EMT). The levels of two miRNAs, miR-374a and miR-138 which targeted ABCB1, were decreased in EBC1-R cells. ABCB1 siRNA and ABCB1 inhibitor elacridar could reduce sphere numbers and suppress EMT. Elacridar could also reverse the resistance to PHA-665752 in EBC1-R cells. Our study demonstrated that ABCB1 overexpression which was associated with CSC properties and EMT was involved in the acquired resistance to MET inhibitor. Inhibition of ABCB1 might be a novel therapeutic strategy for NSCLC patients with acquired resistance to MET inhibitor.
Inhibition of ABCB1 Overcomes Cancer Stem Cell-like Properties and Acquired Resistance to MET Inhibitors in Non-Small Cell Lung Cancer.
Cell line
View SamplesThe purpose of the present study was to investigate the association of glutathione S-transferase P1 (GSTP1) expression with resistance to neoadjuvant paclitaxel followed by 5-fluorouracil/epirubicin/cyclophosphamide (P-FEC) in human breast cancers. The relationship of GSTP1 expression and GSTP1 promoter hypermethylation with intrinsic subtypes was also investigated. In this study, primary breast cancer patients (n = 123, stage II-III) treated with neoadjuvant P-FEC were analyzed. Tumor samples were obtained by vacuum-assisted core biopsy before P-FEC. GSTP1 expression was determined using immunohistochemistry, GSTP1 promoter methylation index (MI) using bisulfite methylation assay and intrinsic subtypes using DNA microarray. The pathological complete response (pCR) rate was significantly higher in GSTP1-negative tumors (80.0%) than GSTP1-positive tumors (30.6%) (P = 0.009) among estrogen receptor (ER)-negative tumors but not among ER-positive tumors (P = 0.267). Multivariate analysis showed that GSTP1 was the only predictive factor for pCR (P = 0.013) among ER-negative tumors. Luminal A, luminal B and HER2-enriched tumors showed a significantly lower GSTP1 positivity than basal-like tumors (P = 0.002, P < 0.001 and P = 0.009, respectively), while luminal A, luminal B and HER2-enriched tumors showed a higher GSTP1 MI than basal-like tumors (P = 0.076, P < 0.001 and P < 0.001, respectively). In conclusion, these results suggest the possibility that GSTP1 expression can predict pathological response to P-FEC in ER-negative tumors but not in ER-positive tumors. Additionally, GSTP1 promoter hypermethylation might be implicated more importantly in the pathogenesis of luminal A, luminal B and HER2-enriched tumors than basal-like tumors.
GSTP1 expression predicts poor pathological complete response to neoadjuvant chemotherapy in ER-negative breast cancer.
Age, Specimen part, Disease stage
View SamplesEndometrial cancer is one of the most common gynecologic malignancies, and patients with high grade disease, especially serous papillary subtype (SPEC) are often related to the poor outcomes. Recent genome-wide analyses have revealed that SPEC exhibits gene expression profiles that are distinct from the endometrioid histologic subtype; therefore, it is important to identify the SPEC driver genes or pathways responsible for the inherently aggressive phenotypes and to develop SPEC-specific therapies to target these driver genes or pathways.
STAT1 drives tumor progression in serous papillary endometrial cancer.
Specimen part, Cell line
View SamplesOvarian cancer often progresses by disseminating to the peritoneal cavity, but how the tumor cells evade host immunity during this process is poorly understood. Programmed cell death 1 ligand 1 (PD-L1) is known to suppress immune system and to be an unfavorable prognostic factor in ovarian cancer. The purpose of this study was to elucidate the function of PD-L1 in peritoneal dissemination. Positive cytology in ascites was a significant poor prognostic factor in ovarian cancer. Microarray profiles of cytology-positive cases showed significant correlations with Gene Ontology terms related to immune system process. Microarray and immunohistochemistry in human ovarian cancer revealed significant correlation between PD-L1 expression and positive cytology. PD-L1 expression on mouse ovarian cancer cells was induced upon encountering lymphocytes in the course of peritoneal spread in vivo and upon co-culturing with lymphocytes in vitro. Tumor cell lysis by CTLs was attenuated when PD-L1 was overexpressed and promoted when it was silenced. PD-L1 overexpression also inhibited gathering and degranulation of CTLs. In mouse ovarian cancer dissemination models, depleting PD-L1 expression on tumor cells resulted in inhibited tumor growth in the peritoneal cavity and prolonged survival. Restoring immune function by inhibiting immune-suppressive factors such as PD-L1 may be a promising therapeutic strategy for peritoneal dissemination.
PD-L1 on tumor cells is induced in ascites and promotes peritoneal dissemination of ovarian cancer through CTL dysfunction.
Age, Specimen part
View SamplesAltered gene expression in the sphingosine 1-phosphate receptor 2 (S1P2)-deficient or sphingosine 1-phosphate receptor 3 (S1P3)-deficient brain.
Frequent spontaneous seizures followed by spatial working memory/anxiety deficits in mice lacking sphingosine 1-phosphate receptor 2.
No sample metadata fields
View SamplesWe comprehensively searched for the factors that may attribute to hepatic insulin sensitivity in the patients with NAFLD. Forty-three NAFLD patients were assessed for putative biomarkers in blood and urine, body composition, tissue lipid content, tissue insulin sensitivity by hyperinsulinemic-euglycemic clamp, hepatic histology and gene expressions using liver biopsies, and life styles. In results, the higher levels of plasma adiponectin, muscle insulin sensitivity, and adipose tissue insulin sensitivity positively, but the higher levels of HbA1c, ALT, and log converted high-sensitive CRP negatively correlated with hepatic insulin sensitivity. Interestingly, whole liver volume and hepatic lean volume corrected by body surface area (cm3/m2) showed significant negative correlation with hepatic insulin sensitivity, specifically in patients with T2DM.
No associated publication
Specimen part, Disease
View SamplesOvarian clear cell carcinoma (OCCC) shows unique clinical features including an association with endometriosis and poor prognosis. We previously reported that the contents of endometriotic cysts, especially high concentrations of free iron, are a possible cause of OCCC carcinogenesis through iron-induced persistent oxidative stress. In this study, we conducted gene expression microarray analysis using 38 ovarian cancer cell lines and identified genes commonly expressed in both OCCC cell lines and clinical samples, which comprise an OCCC gene signature. The OCCC signature reproducibly predicts OCCC specimens in other microarray data sets, suggesting that this gene profile reflects the inherent biological characteristics of OCCC. The OCCC signature contains known markers of OCCC, such as hepatocyte nuclear factor-1b (HNF-1b) and versican (VCAN), and other genes that reflect oxidative stress. Expression of OCCC signature genes was induced by treatment of immortalized ovarian surface epithelial cells with the contents of endometriotic cysts, indicating that the OCCC signature is largely dependent on the tumor microenvironment. Induction of OCCC signature genes is at least in part epigenetically regulated, as we found hypomethylation of HNF-1b and VCAN in OCCC cell lines. This genomewide study indicates that the tumor microenvironment induces specific gene expression profiles that contribute to the development of distinct cancer subtypes.
Identification of an ovarian clear cell carcinoma gene signature that reflects inherent disease biology and the carcinogenic processes.
Sex, Specimen part, Cell line, Treatment
View SamplesTo examine irreversible changes in the developing brain following seizures, juvenile inbred mice were intraperitoneally injected with kainate and nicotine.
Increased expression of the lysosomal protease cathepsin S in hippocampal microglia following kainate-induced seizures.
No sample metadata fields
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