Gene expression profiles of different subpopulations of hepatocellular carcinoma
Ontology highlight
ABSTRACT: To demonstrate CD133+CD44+ and CD133+CD44- subpopulations of hepatocellular carcinoma as distinct subgroups, we have employed whole genome microarray expression profiling as a discovery platform to reveal the gene profiles of different subgroups and identify genes responsible for the enhanced metastatic potentials of CD133+CD44+ tumor cells. CD133+CD44+ and CD133+CD44- tumor cells were isolated from three human metastatic hepatocellular carcinoma specimens. A 76-gene consensus signature was identified that distinguished between CD133+CD44+ and CD133+CD44- subgroups. CD133+CD44+ and CD133+CD44- subgroups from different patients were well clustered as two distinct classes according to this signature, and many genes in this signature were reported involved in tumor metastasis. Expression of four genes (CCL4, DKK3, CCR5 and MMP12) from this signature was confirmed in another three metastatic HCC specimens by real-time PCR. CD133+CD44+ and CD133+CD44- subpopulations of hepatocellular carcinoma were isolated from three metastatic hepatocellular carcinoma specimens by flow cytometry. A total of 30K to 50K cells for each subgroup was obtained for each microarray.
Project description:To demonstrate CD133+CD44+ and CD133+CD44- subpopulations of hepatocellular carcinoma as distinct subgroups, we have employed whole genome microarray expression profiling as a discovery platform to reveal the gene profiles of different subgroups and identify genes responsible for the enhanced metastatic potentials of CD133+CD44+ tumor cells. CD133+CD44+ and CD133+CD44- tumor cells were isolated from three human metastatic hepatocellular carcinoma specimens. A 76-gene consensus signature was identified that distinguished between CD133+CD44+ and CD133+CD44- subgroups. CD133+CD44+ and CD133+CD44- subgroups from different patients were well clustered as two distinct classes according to this signature, and many genes in this signature were reported involved in tumor metastasis. Expression of four genes (CCL4, DKK3, CCR5 and MMP12) from this signature was confirmed in another three metastatic HCC specimens by real-time PCR.
Project description:Cancer stem cells (CSCs) that display tumor-initiating properties have recently been identified. We herein identify and characterize CSCs in human uterine carcinosarcoma, a highly aggressive and therapy-resistant gynecologic malignancy, which is considered to be of mesodermal origin. FU-MMT-1, a cell-line, which was established by us (Emoto M, Cancer 1992) from a patient with uterine carcinosarcoma, was evaluated. FU-MMT-1 contained a high population of CD133, CD44, CD90, and CD29 positive cells. Using the magnetic bead cell separation method, we isolated CD133+ cells, which predominantly form spheres in culture. These CD133+ cells form transplantable tumors in vivo. A qRT-PCR analysis of the genes implicated in stem cell maintenance revealed that CD133+ cells express significantly higher levels of OCT4, NANOG, and BMI-1 than CD133M-oM-<M- cells. Moreover, CD133+ cells showed a high expression of PAX2 and WNT4, which are the essential genes in Mullerian duct formation. The tumor derived from CD133+ cells replicated vimentin, ERM-NM-1, ERM-NM-2, and PR expressionsM-cM-^@M-^@of the parent tumor. These findings suggest that CD133+ FU-MMT-1 cells have the characteristics of CSCs and Mullerian mesenchymal progenitors. CD133+ and CD133- population of FU-MMT-1 cells were analyzed by microarray.
Project description:Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 43 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis. The cancer stem cell hypothesis posits that malignant growth arises from a rare population of progenitor cells within a tumor that provide it with unlimited regenerative capacity. Such cells also possess increased resistance to chemotherapeutic agents. Resurgence of chemoresistant disease following primary therapy typifies epithelial ovarian cancer and may be attributable to residual cancer stem cells, or cancer initiating cells, that survive initial treatment. As the cell surface marker CD133 identifies cancer initiating cells in a number of other malignancies, we sought to determine the potential role of CD133+ cells in epithelial ovarian cancer. We detected CD133 on ovarian cancer cell lines, in primary cancers, and on purified epithelial cells from ascitic fluid of ovarian cancer patients. We found CD133+ ovarian cancer cells generate both CD133+ and CD133- daughter cells, whereas CD133- cells divide symmetrically. CD133+ cells exhibit enhanced resistance to platinum-based therapy, drugs commonly used as first line agents for treatment of ovarian cancer. Sorted CD133+ ovarian cancer cells also form more aggressive tumor xenografts at a lower inoculum than their CD133- progeny. Epigenetic changes may be integral to the behavior of cancer progenitor cells and their progeny. In this regard, we found that CD133 transcription is controlled by both histone modifications and promoter methylation. Sorted CD133- ovarian cancer cells treated with DNA methyltransferase and histone deacetylase inhibitors show a synergistic increase in cell surface CD133 expression. Moreover, DNA methylation at the ovarian tissue active P2 promoter is inversely correlated with CD133 transcription. We also found that promoter methylation increases in CD133- progeny of CD133+ cells, with CD133+ cells retaining a less methylated or unmethylated state. Taken together, our results show that CD133 expression in ovarian cancer is directly regulated by epigenetic modifications and support the idea that CD133 demarcates an ovarian cancer initiating cell population. The activity of these cells may be epigenetically detected and such cells might serve as pertinent chemotherapeutic targets for reducing disease recurrence. The objective of the study was to identify genes that are subject to DNA methylation through pharmacological inhibition of DNA methyltransferase activity in a panel of cancer cell lines. Cells were mock treated with culture media (mock treated) or treated with 5 µM decitabine for 72 hours. Resulting expression profiles were compared to identify genes with altered expression following decitabine treatment. These data represent two experiments: In the first, 43 established cell lines were mock treated or treated with decitabine to enable identification of genes differentially expressed as a result of inhibition of DNA methyltransferase activity. HEYA8-decitabine treated cells were run in replicate. In the second experiment, A2780 and PEO1 cells underwent flow activated cell sorting to separate CD133(+) from CD133(-) cells in each cell line; the sorted cell populations were cultured in the same manner as the first experiment and similarly mock treated or treated with decitabine. All specimens were arrayed in parallel and used for RMA normalization.
Project description:Transcriptional profiling of GIF-5 mouse gastric epithelial cells comparing CD133-positive and CD133-negative cells. The former formed CD133-positive and CD133-negative cells while the latter only CD133-negative cells, suggesting that CD133-positive cells are mother cells. The former produced differentiated type tumors while the latter undifferentiated types in vivo, indicating a relationship between CD133-expression and glandular structure formation. One-condition experiment, CD133-positive vs. CD133-negative cells. 2 replicates.
Project description:Hepatocellular carcinoma (HCC) represents the major subtype of liver cancer, characterized with a high rate of recurrence and heterogeneity. Liver cancer stem cells (CSCs) may account for a hierarchical organization of heterogeneous cancer cells. However, how liver CSCs sustain their self-renewal remains largely unknown. We used microarrays to discover the long non-coding RNAs (lncRNAs) expression underlying cell stem cell (CSC) and non cell stem cell (non-CSC) and identified distinct lncRNAs during this process. We sorted CD13+CD133+ and CD13-CD133- cells from Hep3B, Huh7, and PLC/PRF/5 HCC cell lines as liver CSCs and non-CSCs, then hybridized on Affymetrix microarrays. We sought to identify distinct lncRNAs in liver CSCs.
Project description:BACKGROUND: Several in vitro assays have been used to identify “cancer stem cells” (CSC), including expression of cell surface markers and Hoechst dye efflux properties. However, each of these methods has potential pitfalls that complicate interpretation of the results. Focusing on colon cancers (CC), the CD133 antigen has been proposed as a marker of colon CSC. However, conflicting results have been reported in the literature indicating the need of a systematic analysis of CSC within CC and a complete validation of markers for the isolation of these cells. AIMS: Aim of this study was to confirm that CD133 expression is a valid method for isolating CSC in CC and verify if other antigens can increase the specificity of this marker for isolating CSC in CC. METHODS: CD133+ and CD133- cells were isolated from different human CC lines (CaCo-2, HT29, LOVO, HCT-116) by FACS sorter and the tumor-initiating potential of CD133+ cells was assessed in vitro, by soft-agar colony formation assay, and in vivo, upon transplantation into nude mice. Furthermore, the gene expression profile of CD133+ versus CD133- CaCo-2 cells was compared by the means of microarray analysis. Then, in the effort to identify a common “tumor stem cell” signature for CC, the most relevant transcripts resulting from gene expression profiling on CD133+ cells was assessed by real-time PCR on SP-fraction isolated by FACS sorter from the same CC cell lines. Finally, we deplete CD133 expression in the CaCo-2 cell line by the means of siRNA and verified by Western Blot analysis whether there was a functional correlation between CD133 and the target genes. Moreover, CaCo-2 and HCT116 cells were exposed to sodium butyrate (NaBu) for 72h. Colon cells differentiation was assessed by Alkaline phosphatase activity and expression of CD133 and target genes was tested by western blot. RESULTS: We confirmed that only CD133+ cells have a tumor-initiating potential in vitro and in vivo. Furthermore, microarray analysis of CD133+ versus CD133- CaCo-2 cells revealed a significant overexpression of various transcripts involved in cell proliferation, invasion and stemness in CD133+ cell fraction. Comparison of the transcripts by real-time PCR revealed that the genes of Endothelin-1 (END-1) and NR4A2 are highly expressed in both CD133 + cells and in SP fractions. Finally, when we deplete CD133 expression in Caco-2cells by siRNA, we observed a significant attenuation of END-1 and NR4A2 expression, thus demonstrating that CD133 is involved in the transcriptional regulation of these genes. Interestingly, we also showed that the expression of all three genes was inversely correlated with cell differentiation status as demonstrated by the fact that their expression decreases in a time- and dose-dependent manner after differentiation induced by NaBu. CONCLUSION: Overall, this study confirms the role of CD133antigen as CSC marker and showed for the first time the existence of a functional relationship between CD133, END-1 and NR4A2 expression, hypothesizing that CD133 is involved in the transcriptional regulation of these gene. Microarray analysis was performed on CD133+ and CD133- sorted CACO-2 cells. For both fractions, cells were sorted three independent times. Sample preparation was performed according to Affymetrix recommendations. A total of 6 arrays were hybridized, including 3 CD133+ replicates and 3 CD133- replicates.
Project description:Aims: We explore the role of elevated O2-:H2O2 ratio as a prosurvival signal in glioma-propagating cells (GPCs). We hypothesize that depleting this ratio sensitizes GPCs to apoptotic triggers. Results: We observed that elevated O2-:H2O2 ratio conferred enhanced resistance in GPCs, and depletion of this ratio by pharmacological and genetic methods sensitized cells to apopotic triggers. We established the ROS Index as a quantitative measure of normalized O2-:H2O2 ratio and determined its utility in predicting chemosensitivity. Importantly, mice implanted with GPCs of reduced ROS Index demonstrated extended survival. Analysis of tumor sections revealed effective targeting of CD133- and nestin-expressing neural precursors. Furthermore, we established the Connectivity Map to interrogate a gene signature derived from varied ROS Index for patterns of association with individual patient gene expression in 2 clinical databases. We showed that patients with reduced ROS Index demonstrate better survival. These data provide clinical evidence for the viability of our O2-:H2O2-mediated chemosensitivity profiles. Innovation and Conclusion: Gliomas are notoriously recurrent and highly infiltrative, and have been shown to arise from stem-like cells. We implicate elevated O2-:H2O2 ratio as a prosurvival signal in GPC self-renewal and proliferation. The ROS Index provides quantification of O2-:H2O2-mediated chemosensitivity, an advancement in a previously qualitative field. Intriguingly, glioma patients with reduced ROS Index correlate with longer survival and the Proneural molecular classification, a feature frequently associated with tumors of better prognosis. These data emphasize the feasibility of manipulating the O2-:H2O2 ratio as a therapeutic strategy. Total RNA from primary neurosphere culture of brain tumor specimens treated with DPI and DDC as well as non-treated CD133+ and CD133- fractions were compared. Specimens were obtained from 3 patients and replicate arrays were performed for all 3 neurosphere cultures.
Project description:Given the very substantial heterogeneity of most human cancers, it is likely that most cancer therapeutics will be active in only a small fraction of any population of patients. As such, the development of new therapeutics, coupled with methods to match a therapy with the individual patient, will be critical to achieving significant gains in disease outcome. One such opportunity is the use of expression signatures to identify key oncogenic phenotypes that can serve not only as biomarkers but also as a means of identifying therapeutic compounds that might specifically target these phenotypes. Given the potential importance of targeting tumors exhibiting a stem-like phenotype, we have developed an expression signature that reflects common biological aspects of various stem-like characteristics. The Consensus Stemness Ranking (CSR) signature is upregulated in cancer stem cell enriched samples, at advanced tumor stages and is associated with poor prognosis in multiple cancer types. Using two independent computational approaches we utilized the CSR signature to identify clinically useful compounds that could target the CSR phenotype. In vitro assays confirmed selectivity of several predicted compounds including topoisomerase inhibitors and resveratrol towards breast cancer cell lines that exhibit a high-CSR phenotype. Importantly, the CSR signature could predict clinical response of breast cancer patients to a neoadjuvant regimen that included a CSR-specific agent. Collectively, these results suggest therapeutic opportunities to target the CSR phenotype in a relevant cohort of cancer patients. CD133+ and CD133- cells were separated from two glioma xenograft tumors. Both CD133+ and CD133- glioma cells were cultured in serum-free media for 48 hours in the presence of absence of laminin.
Project description:Expression from CD133+ cells isolated from adult human exocrine tissue was compared to a CD133-depleted cell population Islet-depleted exocrine tissue from three independent adult human cadaveric pancreata were cultured for four days in Miami media 1A. Following trypsinization, cells were isolated using anti-CD133 immunomagnetic beads to >95% CD133+. CD133-negative cells were further depleted of CD133+ cells to <1% CD133+.
Project description:Nine heterogeneous melanoma cell lines including D10 and WM115 were studied for cancer stem cell characteristics in vitro. D10 cell line was the only cell line expressing the cancer stem cell marker CD133. Thus, gene expression profiling on CD133+ and CD133- D10 cells was carried out using Affymetrix GeneChips Human Genome U133A 2.0.