Cancer Stem Cell Markers CD44 Research Articles

Abstract P2-06-01: Development of a fluorescent reporter system to delineate self-renewing cells in triple negative breast cancer

Abstract Background : Advanced cancers including triple-negative breast cancer (TNBC), the most aggressive breast cancer subtype, contain a self-renewing, tumorigenic cancer stem cell (CSC) population. CSCs contribute to tumor progression and therapeutic resistance. Despite an effective early response to chemotherapy, TNBC relapses with a highly heterogeneous and refractory metastatic disease enriched in CSCs. Apart from being chemo- and radio-resistant, CSCs display a high degree of multipotency, heterogeneity and plasticity. Due to the complex nature of CSCs, elucidating the characteristics of CSCs in TNBC progression continues to be a challenge. Thus, developing anti-CSC therapies to be integrated into clinical paradigms represents an immediate priority. Rationale : A major obstacle to the identification of CSC regulatory mechanisms is the lack of experimental systems that enable the reliable enrichment of CSCs from non-CSCs for comparative analysis. While CSCs have been isolated from TNBC using CD44+/CD24- and/or ALDH+ phenotype, this enrichment paradigm requires refinement as it is not universally applicable and lacks the ability to study CSCs in real time. The limitations of these systems have excluded their application in studying the molecular heterogeneity among breast cancer tumors. CSCs are molecularly characterized based on the expression of cell surface receptors and the embryonic stem cell transcription factors NANOG, OCT4 and SOX2. NANOG, the master regulator of stem cell self-renewal, has emerged as a pro-carcinogenic factor in cancer cell lines with CSC behavior. Our previous studies have shown that silencing NANOG in cancer cells leads to reduced proliferation and self-renewal based on in vitro and in vivo experiments. Hypothesis : We hypothesized that a Nanog promoter could be used to effectively enrich for TNBC CSCs. Results : We generated two TNBC cell lines (MDA-MB-231 and HCC70) harboring NanogGFP reporter gene by lentiviral transductions. Increased NANOG mRNA and protein expression was observed in flow cytometry-sorted GFP+ cells compared with GFP- cells. GFP+ cells were enriched for the CSC markers CD49f and CD44+/CD24-. GFP+ cells also demonstrated an increased protein expression of the stem cell transcription factors NANOG, SOX2 and OCT4. Limiting dilution analyses revealed increased self-renewal and significantly higher stem cell frequencies in GFP+ cells. GFP+ cells demonstrated a mesenchymal phenotype with increased invasive capacity. Subcutaneous injections of GFP+ cells showed significantly higher in vivo tumor initiation and progression than GFP- cells. Flow cytometry-sorted GFP+ and GFP- cells enriched for CSCs and non-CSCs, respectively. Using this system, we performed a high-throughput flow cytometry screen and identified an additional novel CSC marker for TNBC. Conclusion : We have developed a novel TNBC CSC reporter system using a GFP reporter driven by the Nanog promoter and identified a novel CSC marker. We have defined and validated this robust system wherein we have characterized and monitored the role of CSCs and non-CSCs in TNBC tumor initiation and progression. Using this approach, identifying CSC targets in TNBC could unravel the potential for development of innovative therapeutic strategies. Citation Format: Praveena S Thiagarajan, Masahiro Hitomi, James S Hale, Alvaro G Alvarado, Baltin Otvos, Kevin Stoltz, Maksim Sinyuk, Awad Jarrar, Qiao Zheng, Dustin Thomas, Thomas Egelhoff, Jeremy N Rich, Justin D Lathia, Ofer Reizes. Development of a fluorescent reporter system to delineate self-renewing cells in triple negative breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-06-01.

Clinicopathological significance and prognostic value of the expression of the cancer stem cell marker CD133 in hepatocellular carcinoma: a meta-analysis

To conduct a meta-analysis to assess the association between CD133 expression and clinicopathological significance and prognostic value in hepatocellular carcinoma patients. Studies were identified via an electronic comprehensive literature search through the Pubmed, Chinese CNKI, and Wanfang databases. This meta-analysis was performed using Stata statistical software version 12.0. The outcomes included various clinicopathological and survival parameters (P < 0.05 was consider to indicate a statistical significance). A total of 21 studies comprising 2592 patients were included in this meta-analysis. CD133 overexpression was significantly associated with a series of clinicopathological parameters, such as low tumor differentiation (pooled odds ratio (OR) = 2.26, 95% CI: 1.59-3.21, P < 0.00001), advanced tumor stage (pooled OR = 2.17, 95% CI: 1.70-2.77, P < 0.00001), vascular invasion (pooled OR = 2.06, 95% CI: 1.25-3.39, P = 0.005), and vascular thrombosis (pooled OR = 1.47, 95% CI: 1.08-1.99, P = 0.015). However, CD133 expression was not correlated with hepatitis, cirrhosis, α-fetoprotein level, tumor number, tumor size, encapsulation, or metastasis. Regarding survival outcome, CD133 overexpression was significantly correlated with poor overall survival (pooled hazard ratio (HR) = 2.01, 95% CI: 1.45-2.80, P = 0.00002) and poor disease-free survival (pooled HR = 1.82, 95% CI: 1.45-2.29, P < 0.00001). This meta-analysis indicated that CD133 overexpression is significantly associated with clinicopathological factors and poorer survival outcome.

Correlation of mesenchymal differentiation and ion‐channel activity in radiation‐induced resistant human glioblastoma cell line

Due to development of therapeutic induced resistance, gliobalstoma multiforme (GBM) is one of the most difficult-to-treat primary brain cancers. In this study, we were using sequential irradiation to induce resistant GBM cell line. The effect of radiation doses on cell viability were examined by trypan blue. Based on the viability results, we chose radiation dosage of 50% viability for sequential irradiation. When viability of cells were recovered from radiation exposures which were comparable to positive control. We determined that 3.5Gy exposure for 6 times were needed. Immunocytochemistry staining and immunoblotting to examine resistant and control cell lines were used. We found epithelial markers beta-catenin and E-cadherin; mesenchymal markers N-cadherin, fibronectin, and vimentin; and cancer stem cell markers CD133 and CD15 were changed after sequential irradiation. BKCa-channel activity was initially elevated in resistant cell line, which was interestingly correlated to the expression profiles epithelial and mesenchymal markers, which are beta-catenin andN-cadherin. The probability of BKCa-channel openings in 13-06MG cells was diminished, while the activity of intermediate-conductance Ca2+-activated K+ and inwardly rectifying K+ channels remained active. We conclude changes in the activity of BKCa channels in radiation resistant GBM cell line 13-06MG are correlated to the epithelial and mesenchymal phenotype differentiation.

6 CD98 identifies a clinically relevant subpopulation of head and neck squamous cell carcinoma cells with stem cell properties

Introduction Patients with advanced head and neck squamous cell carcinomas (HNSCC) are often treated with concomitant chemotherapy and radiotherapy, but only 50% is cured. A possible explanation for treatment failure is therapy resistance of the cancer stem cells (CSCs). The application of compounds specifically targeting these CSCs, in addition to routinely used therapeutics, would likely improve clinical outcome. We set out to identify the CSC population in HNSCC. Previously, we found that the antibody K984 specifically targets the cells composing the squamous basal cell layer, the area where HNSCC CSCs likely reside. Materials and methods Immunoprecipitation and mass spectrometry was used to identify the antigen targeted by the K984 antibody. Next, flow cytometry was used to separate cell populations with high and low K984 antigen expression and these populations were tested for tumorigenicity in immunodeficient mice. Gene expression arraying was applied to further characterize the cell populations. In addition, to investigate the clinical importance of CSC presence in HNSCC, a large cohort of oropharyngeal tumors was immunohistochemically examined for K984 antigen positivity, as well as for CD44 expression, and the scoring results were associated with clinical outcome. Results We demonstrated that the monoclonal antibody K984 recognizes the CD98 cell surface protein and showed that CD98high cells, in contrast to CD98low cells, are able to generate tumors in immunodeficient mice. This indicates that CD98high cells have stem cell characteristics. Furthermore, the CD98high subpopulation expressed high levels of cell cycle control and DNA repair genes, while the CD98low fraction showed expression patterns that represent the more differentiated cells that form the bulk of the tumor. HPV-positive tumors expressed lower levels of CSC markers CD44 and CD98 than HPV-negative tumors. The number of CD98-positive cells was significantly associated with outcome in HPV-positive tumors, but not in HPV-negative tumors. CD44 expression was not associated with clinical outcome. Conclusion CD98 is a promising CSC enrichment marker in HNSCC. Our data support the CSC concept in head and neck cancer and the potential relevance of these cells for treatment outcome.

СD44+/CD24− MARKERS OF CANCER STEM CELLS IN PATIENTS WITH BREAST CANCER OF DIFFERENT MOLECULAR SUBTYPES

To determine frequency of tumors with immunohistochemical markers of cancer stem cells (CSC) CD44+/CD24- in patients with breast cancer (BC) of different molecular subtype and to evaluate their prognostic value. Surgical material of 132 patients with BC stage I-II, age from 23 to 75 years, mean age - 50.2 ± 3.1 years was studied. Clinical, immunohistochemical (expression CD44+/CD24-), morphological, statistical. BC is characterized by heterogeneity of molecular subtypes and expression of markers (CD44+/CD24-). Immunohistochemical study of expression of CSC markers in surgical material has detected their expression in 34 (25.4%) patients with BC of different molecular subtypes. The highest frequency of cells with expression of CSC marker was observed in patients with basal molecular subtype (44.8% patients). Most of BC patients with phenotype CD44+/CD24 had stage I of tumor process (34.3%). Statistical processing of data has showen that Yule colligation coefficient equaled 0.28 (р > 0.05) that argues poor correlation between stage of tumor process and number of tumors with positive expression of CSC markers. Statistical processing of data has showen high correlation between presence of cells with expression of CSC markers and metastases of BC in regional lymph nodes (Yule colligation coefficient equals 0.943; р < 0.5). Difference in overall survival of patients with BC of basal molecular subtype depending on expression of CSC CD44+/CD24- markers was detected. Survival of patients with basal BC was reliably higher at lack in tumors of cells with CSC markers CD44+/CD24- and, correspondingly, lower at presence of such cells (р < 0.05). In patients with BC of luminal (A and B), HER-2-positive subtypes, significant change in survival of patients depending on expression of CSC markers was not determined (р > 0.05). Significance of tumor cells with markers CD44+/CD24- within the limits of molecular subtype of BC may be additional criterion for advanced biological characteristic of BC, and in patients with BC of basal molecular subtype - for predictive evaluation of individual potential of tumor to aggressive clinical course.

Light-controlled endosomal escape of the novel CD133-targeting immunotoxin AC133–saporin by photochemical internalization — A minimally invasive cancer stem cell-targeting strategy

The cancer stem cell (CSC) marker CD133 is an attractive target to improve antitumor therapy. We have used photochemical internalization (PCI) for the endosomal escape of the novel CD133-targeting immunotoxin AC133–saporin (PCIAC133–saporin). PCI employs an endocytic vesicle-localizing photosensitizer, which generates reactive oxygen species upon light-activation causing a rupture of the vesicle membranes and endosomal escape of entrapped drugs. Here we show that AC133–saporin co-localizes with the PCI-photosensitizer TPCS2a, which upon light exposure induces cytosolic release of AC133–saporin. PCI of picomolar levels of AC133–saporin in colorectal adenocarcinoma WiDr cells blocked cell proliferation and induced 100% inhibition of cell viability and colony forming ability at the highest light doses, whereas no cytotoxicity was obtained in the absence of light. Efficient PCI-based CD133-targeting was in addition demonstrated in the stem-cell-like, triple negative breast cancer cell line MDA-MB-231 and in the aggressive malignant melanoma cell line FEMX-1, whereas no enhanced targeting was obtained in the CD133-negative breast cancer cell line MCF-7. PCIAC133–saporin induced mainly necrosis and a minimal apoptotic response based on assessing cleavage of caspase-3 and PARP, and the TUNEL assay. PCIAC133–saporin resulted in S phase arrest and reduced LC3-II conversion compared to control treatments. Notably, co-treatment with Bafilomycin A1 and PCIAC133–saporin blocked LC3-II conversion, indicating a termination of the autophagic flux in WiDr cells. For the first time, we demonstrate laser-controlled targeting of CD133 in vivo. After only one systemic injection of AC133–saporin and TPCS2a, a strong anti-tumor response was observed after PCIAC133–saporin. The present PCI-based endosomal escape technology represents a minimally invasive strategy for spatio-temporal, light-controlled targeting of CD133+ cells in localized primary tumors or metastasis.

Expression of Cancer Stem Cell Markers CD44, ABCG2 and Podoplanin in Progression of Oral Squamous Cell Carcinoma

Expression of Cancer Stem Cell Markers CD44, ABCG2 and Podoplanin in Progression of Oral Squamous Cell Carcinoma

Colon cancer stem cell markers CD44 and CD133 in patients with colorectal cancer and synchronous hepatic metastases.

CD44 and CD133 mRNA expression as cancer stem cell markers in colorectal cancer were correlated with synchronous hepatic metastases and the clinicopathological factors, including patient survival. The CD44 and CD133 mRNA levels in 36 primary colorectal adenocarcinomas with synchronous hepatic metastasis were analyzed by reverse transcriptase polymerase chain reaction, with normalization relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Immunohistochemical analysis was performed on samples with typical mRNA expression patterns to investigate protein expression. Both CD44 and CD133 gene expressions were highest in hepatic metastasis tissue, followed by colorectal cancer and normal mucosa. The differences were statistically significant among groups of normal mucosa, colorectal cancer and hepatic metastasis tissue. CD44 mRNA expression was significantly associated with the tumor location (P=0.019) and histology (P=0.026). With a median follow-up period of 38 months, the 5-year disease-free survival rate of the patients with high CD44 mRNA expression in the CD44 hepatic metastasis tissue group was significantly lower than that of the patients with low expression (P=0.002). While the mRNA expressions in groups of CD44 colorectal tumor, CD133 colorectal tumor, and CD133 hepatic metastasis tissue were not significant. CD44 and CD133 mRNA were highly correlatively co-expressed in colorectal cancer with hepatic metastases. CD44 expression was an independent factor associated with patient survival, while CD133 did not show this pattern. Thus, CD44 is a more reliable marker for predicting hepatic metastases and survival. Larger prospective studies are required to confirm these findings.

The chemokines CXCL9 and CXCL13 as prognostic markers for metastasis and survival in rectal cancer patients after neoadjuvant chemoradiation.

627 Background: Distant metastasis is a challenging problem in multimodal treatment of rectal cancer. Valid prognostic markers for the occurrence of metachronous metastasis could help to stratify patients who qualify for adjuvant chemotherapy and intensified follow-up procedures after preoperative chemoradiotherapy (CRT). Methods: We analysed 9 different genes known to prominently figure in crucial pathways of the tumor cell metabolism. mRNA was isolated and quantified from surgical specimens of 77 rectal cancer patients undergoing neoadjuvant CRT. The panel contains genes with relevant function in apoptosis (Birc5, XIAP, SMAC) and epithelial-mesenchymal transitions (SNAI2) as well as the cancer stem-cell marker CD133, the transcription factor ESR1 and the lymphocyte-chemokines CXCL9 and 13. The expression levels in post-CRT rectal cancers were correlated with the development of distant metastasis and with disease-free (DFS) and cancer-specific overall survival (CSS). Results: Intratumoral mRNA expression of the T-cell chemokine CXCL9 (p&lt;0.001) and the B-cell chemokine CXCL13 (p&lt;0.01) was inversely correlated with the occurrence of distant metastasis. Patients with isolated high CXCL9 (p&lt;0.0001) and CXCL13 levels (p&lt;0.01) had a significantly prolonged DFS. Patients with simultaneous expression of CXCL9 and 13 had an excellent DFS compared to patients without expression of any of the chemokines (p&lt;0.0001). Additionally, CXCL9 expression was correlated with an improved CSS (p&lt;0.05). There was no significant correlation between expression levels of the other genes tested and metastasis or survival. Conclusions: The post-CRT expression of the lymphocyte-chemokines CXCL9 and 13 is associated with reduced rates of distant metastases and improved survival in rectal cancers after CRT. Further investigations are needed to prospectively validate these results and characterize the underlying cellular and molecular mechanisms.

Cd133/Epcam Cancer Stem Cell Markers of Tumour Stage in Colorectal Cancer Cells

In solid tumours, a discreet population of tumour associated cancer stem cells (CSCs) are proposed to drive and sustain tumour development and be responsible for tumour relapse. Colorectal cancer stem cells express cellspecific surface markers, including amongst others, CD133, EpCAM, CD44, CD166, and CD94f. In the present study, we aimed to characterisecellpopulations in the human colon adenocarcinoma cell lines, SW1116, HT29 and DLD1, expressing both CSC markers CD133 and EpCAM. These cell lines represent early, mid and late stages of colorectal tumours, respectively. Up to 107 SW1116, HT29 and DLD1 cells, co-stained with anti-CD133 and anti-EpCAM, were evaluated using flow cytometry. We report here progressive increasing proportions of cells coexpressing the CD133/EpCAM epitopes in the respective cell lines. In the SW1116 cell line, 2.42 ± 0.20 percent of cells were CD133+EpCAM+, in the HT29 cell line, 5.13 ± 0.17 percent of cells were CD133+EpCAM+, and in the DLD1 cell line, 10.30 ± 0.2 percent of cells were CD133+EpCAM+. These data suggest the frequency of CD133/ EpCAM marker expression may be associated with tumour stage and aggression.

CD44 expression in patients with combined hepatocellular cholangiocarcinoma.

PurposeCombined hepatocellular cholangiocarcinoma (ChC) is a rare type of primary liver cancer, which is thought to have a poorer prognosis than hepatocellular carcinoma (HCC). Cancer stem cells are associated with tumorigenesis, tumor progression, recurrence, metastasis, and poor prognosis in several malignancies including HCC. The aim of this study was to investigate the expression pattern of cancer stem cell markers in ChC and HCC, and to evaluate whether this pattern correlated to patient prognosis.MethodsThirteen patients who underwent curative hepatic resection for ChC and 13 patients who underwent curative hepatic resection for HCC (matched control cases) were included. Immunohistochemical staining for cancer stem cell markers (cytokeratin [CK]7, CK19, C-kit, cluster of differentiation [CD] 44, CD133, and epithelial cell adhesion molecule) was performed and clinical outcomes were analyzed retrospectively.ResultsThere was no significant difference in cancer stem cell marker expression between ChC and HCC. In ChC, the group that expressed CD44 showed earlier recurrence than the group that did not express CD44 (P = 0.040).ConclusionThe expression of cancer stem cell markers in ChC did not show a different pattern compared to that found in HCC. The expression of cancer stem cell marker CD44 was associated with poor prognosis in patients with ChC.

Expression of the Cancer Stem Cell Markers CD44 and CD133 in Colorectal Cancer: An Immunohistochemical Staining Analysis.

PurposeThe aim of this study was to assess the expressions of CD44 and CD133 in colorectal cancer tissue by using immunohistochemical staining and to analyze the clinical significance of the expressions related to other clinicopathological data and survival results.MethodsOne hundred sixty-two patients with a biopsy-proven colorectal adenocarcinoma who were operated on between January 1998 and August 2004 were enrolled in this study. Immunohistochemical staining for CD44 and CD133 was performed on primary colorectal cancer tissue, metastatic lymph nodes, and synchronous and metachronous metastatic tumor tissues if available.ResultsCD44 expression was stronger in the primary tumor than in metastatic lymph nodes (P < 0.001), and CD133 expression tended to be stronger in primary tumor than in metastatic lymph nodes (P = 0.057). No significant correlation was found between the CD44 and the CD133 expressions. The cases with recurrence showed low expression of CD44 (P = 0.017). CD133 expression was lower in cases with elevated CA 19-9 serum levels (P = 0.028) and advanced T stage (P = 0.038). Multivariate analysis proved that low expression of CD44 was an independent prognosis factor for short disease-free survival (P = 0.028).ConclusionLow CD44 expression was correlated with increased tumor recurrence and short disease-free survival, and low CD133 expression was associated with advanced tumor stage. We suggest that further studies be performed to evaluate whether the immunohistochemical method for determining the CD44 and the CD133 expressions is appropriate for exploring cancer stem-cell biology in patients with colorectal cancer.

Surgically resected human tumors reveal the biological significance of the gastric cancer stem cell markers CD44 and CD26.

Cancer tissue is maintained by relatively small populations of cancer stem cells (CSCs), which are involved in chemotherapy resistance, recurrence and metastasis. As tumor tissues are comprised of various cells, studies of human clinical samples are important for the characterization of CSCs. In the present study, an expression profiling study was performed in which an anti-cell surface marker antibody-based array platform, a flow cytometry-based cell separation technique and a tumorigenicity analysis in immunodeficient animals were utilized. These approaches revealed that the markers cluster of differentiation (CD)44 and CD26 facilitated the fractionation of surgically resected human gastric cancer (GC) cells into the following subset populations with distinct tumorigenic potentials: Highly tumorigenic CD26+CD44+ cells (6/6 mice formed tumors), moderately tumorigenic CD26+CD44- cells (5/6 mice formed tumors), and weakly or non-tumorigenic CD26-CD44- cells (2/6 mice formed tumors). Furthermore, exposure to 5-fluorouracil significantly increased the proportion of CD26+ cells in vitro. The present study demonstrated that the combined expression of CD26 and CD44 presents a potential marker of human GC stem cells.

Galectin-3 augments tumor initiating property and tumorigenicity of lung cancer through interaction with β-catenin.

Cancer stem cells (CSCs) are comprised of a rare sub-population of cells in tumors that have been proposed to be responsible for high recurrence rates and resistance to chemotherapy. Galectins are highly expressed in cancers that correlate with the aggressiveness of tumors. Galectins may also promote the resistance of cancer cells to chemotherapy. However, the role of galectins in CSCs remains unknown. In this study, sphere formation was used to enrich H1299 human lung CSCs that had self-renewal ability, advanced tumorigenic potential, and that highly expressed stem/progenitor cell markers such as Oct4, Sox2, Nanog, and CD133. A novel candidate molecule, galectin-3, for stemness was found in lung CSCs. The expression of galectin-3 robustly increased in lung cancer spheres over serial passages, but its suppression in the H1299 monolayer or spheres resulted in reduced expression of stemness-related genes, sphere-forming ability, tumorigenicity, chemoresistance, and tumor initiation in mice. Notably, the overexpression of galectin-3 in A549 lung cancer cells, which have low capability to grow as tumor spheres, promoted CSC formation. β-catenin activity was increased in H1299 spheres and counteracted by galectin-3 suppression. Thus, galectin-3 may act as a cofactor by interacting with β-catenin to augment the transcriptional activities of stemness-related genes. Furthermore, galectin-3 expression correlated with tumor progression and expressions of β-catenin and CSC marker CD133 in lung cancer tissues. Targeting galectin-3 signaling may provide a new strategy for lung cancer treatment by inhibiting stem-like properties.

Combined epithelial-mesenchymal transition with cancer stem cell-like marker as predictors of recurrence after radical resection for gastric cancer.

BackgroundThe aim of the study was to identify the incidence and the predictors of recurrence after curative resection and the clinical significance of epithelial-mesenchymal transition (EMT) and stem cell-like phenotypes in gastric cancer.MethodsIn a total of 1,463 patients that underwent curative resection for gastric cancer between January 2001 and January 2008 at Drum Tower Hospital, 402 (27.5%) experienced recurrence. They were divided into early recurrence (within two years) and late recurrence (more than two years). The clinicopathological characteristics, including five EMT-related proteins (Snail-1, ZEB-1, E-cadherin, vimentin, and β-catenin) and the gastric cancer stem cell markers CD44 and CD54, therapeutic modalities, survival time after recurrence, and recurrence patterns were compared between the two groups.ResultsLoss of E-cadherin expression and aberrant expression of vimentin and the known gastric cancer stem cell maker CD44 were significantly associated with aggressive clinicopathologic features. Multivariate analysis showed that stage III gastric cancer patients with early recurrence had larger tumors and more lymph node metastasis, coupled with aberrant expression EMT and cancer stem cell marker, than patients with late recurrence. Early recurrence was associated with more distant metastasis than late recurrence and patients tended to die within two years of recurrence.ConclusionsCombined EMT with cancer stem cell-like marker is a predictor of recurrence after radical resection for gastric cancer. Advanced TNM stage was associated with early cancer death after recurrence.

Platinum sensitivity and CD133 expression as risk and prognostic predictors of central nervous system metastases in patients with epithelial ovarian cancer.

BackgroundTo characterize prognostic and risk factors of central nervous system (CNS) metastases in patients with epithelial ovarian cancer (EOC).MethodsA retrospective analysis of Xijing Hospital electronic medical records was conducted to identify patients with pathologically confirmed EOC and CNS metastases. In addition to patient demographics, tumor pathology, treatment regimens, and clinical outcomes, we compared putative cancer stem cell marker CD133 expression patterns in primary and metastatic lesions as well as in recurrent EOC with and without CNS metastases.ResultsAmong 1366 patients with EOC, metastatic CNS lesions were present in 29 (2.1%) cases. CD133 expression in primary tumor was the only independent risk factor for CNS metastases; whilst the extent of surgical resection of primary EOC and platinum resistance were two independent factors significantly associated with time to CNS metastases. Absence of CD133 expression in primary tumors was significantly associated with high platinum sensitivity in both patient groups with and without CNS metastases. Platinum resistance and CD133 cluster formation in CNS metastases were associated with decreased survival, while multimodal therapy including stereotactic radiosurgery (SRS) for CNS metastases was associated with increased survival following the diagnosis of CNS metastases.ConclusionsThese data suggest that there exist a positive association between CD133 expression in primary EOC, platinum resistance and the increased risk of CNS metastases, as well as a less favorable prognosis of EOC. The absence of CD133 clusters and use of multimodal therapy including SRS could improve the outcome of metastatic lesions. Further investigation is warranted to elucidate the true nature of the association between platinum sensitivity, CD133 expression, and the risk and prognosis of CNS metastases from EOC.

470 Transcriptional regulation of cancer stem cells marker CD133 by p53

470 Transcriptional regulation of cancer stem cells marker CD133 by p53

Brefeldin A reduces anchorage-independent survival, cancer stem cell potential and migration of MDA-MB-231 human breast cancer cells.

Cancer stem cells (CSCs) are a subset of cancer cells in tumors or established cancer cell lines that can initiate and sustain the growth of tumors in vivo. Cancer stem cells can be enriched in serum-free, suspended cultures that allow the formation of tumorspheres over several days to weeks. Brefeldin A (BFA) is a mycotoxin that induces endoplasmic reticulum (ER) stress in eukaryotic cells. We found that BFA, at sub-microgram per milliliter concentrations, preferentially induced cell death in MDA-MB-231 suspension cultures (EC50: 0.016 µg/mL) compared to adhesion cultures. BFA also effectively inhibited clonogenic activity and the migration and matrix metalloproteinases-9 (MMP-9) activity of MDA-MB-231 cells. Western blotting analysis indicated that the effects of BFA may be mediated by the down-regulation of breast CSC marker CD44 and anti-apoptotic proteins Bcl-2 and Mcl-1, as well as the reversal of epithelial-mesenchymal transition. Furthermore, BFA also displayed selective cytotoxicity toward suspended MDA-MB-468 cells, and suppressed tumorsphere formation in T47D and MDA-MB-453 cells, suggesting that BFA may be effective against breast cancer cells of various phenotypes.

Clinical significance of putative cancer stem cell marker CD44 in different histological subtypes of lung cancer.

According to the cancer stem cell theory, tumors originate from a subset of cells known as cancer stem cells (CSCs) that are responsible for tumor initiation, resistance and relapse. CD44 is a cell adhesion molecule that can aid in the identification of CSCs in various malignancies. The purpose of the current study is to evaluate the expression level and clinical significance of CD44 in lung cancer samples. One hundred and ninety-five lung tumor samples including 74 (38%) squamous cell carcinomas (SCC), 61 (31%) adenocarcinomas (ADC), 23 (12%) large cell carcinoma (LCC) in non-small cell lung cancer (NSCLC) group and 37 (19%) small cell lung cancer (SCLC) samples were examined for the expression of CD44 using immunohistochemistry method. The correlation of CD44 expression with clinicopathological parameters as well as Ki-67 status was also assessed. Univariate analysis demonstrated that CD44 expression was significantly higher in NSCLC compared to SCLC (P < 0.001). Among NSCLC, higher level of CD44 expression was found in SCC compared to ADC (P< 0.001) and LCC (P=0.046). Increased expression of CD44 was significantly correlated with higher grade tumors which correspond to poor prognosis in SCC (P=0.012) and the lower level of CD44 expression was more often found in well differentiated ADC tumors (P=0.03). In addition, high expression of CD44 was significantly associated with decreased level of proliferative marker Ki-67 (P=0.04). CD44 could be a valuable tool for the study of lung CSCs and provide a novel therapeutic target for treatment of the patients with lung cancer in combination with conventional therapy.

Abstract LB-53: Regulatory role of miR-142-3p on the functional hepatic cancer stem cell marker CD133

Abstract Tumor relapse after therapy typifies hepatocellular carcinoma (HCC) and is believed to be attributable to residual cancer stem cells (CSCs) that survive initial treatment. We have previously identified a CSC population derived from HCC that is characterized by the expression of the transmembrane glycoprotein, CD133. Despite our growing knowledge of the importance of a functional CD133+ liver CSC subset in driving HCC, the regulatory mechanism of CD133 is not known. Epigenetic changes are believed to be essential in the control of cancer and stem cells. We report here the dynamic epigenetic regulation of the functional liver CSC marker CD133 by promoter methylation and miR-142-3p regulation. Unlike in other tumor types, we found DNA methylation to only play a minor role in the control of CD133 expression in HCC. More importantly, our results revealed that miR-142-3p plays an integral part in the direct targeting of CD133. The interaction between the 3’UTR of CD133 and miR-142-3p was identified by in silico prediction and substantiated by luciferase reporter analysis. Expression of CD133 was found to be inversely correlated with miR-142-3p in a panel of liver cell lines and HCC clinical samples. Functional studies with miR-142-3p stably transduced in HCC cells demonstrated a diminished ability to self-renew, initiate tumor growth, invade, migrate, induce capillary tube formation in endothelial cells and resist standard chemotherapy. Rescue experiments whereby CD133 and miR-142-3p is simultaneously overexpressed compensated the deregulated ability of the cells to confer these cancer and stem cell-like features. In summary, our findings suggestion promoter methylation to only play a minor role in the regulation of CD133 in HCC; and that miR-142-3p directly targets CD133 to regulate its ability to confer cancer and stem cell-like features in HCC. Citation Format: Kai Yu Ng, Stella Chai, Man Tong, Pak Shing Kwan, Yuen Piu Chan, Terence Kin Wah Lee, Nathalie Wong, Xin-Yuan Guan, Stephanie Ma. Regulatory role of miR-142-3p on the functional hepatic cancer stem cell marker CD133. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-53. doi:10.1158/1538-7445.AM2014-LB-53