Cancer Stem Cell Marker Aldehyde Research Articles

Immunohistochemical expression of putative cancer stem cell markers aldehyde dehydrogenase 1, SOX2, CD44 and OCT4 in different grades of oral epithelial dysplasia.

The hypothesized existence of cancer stem cells (CSC) and its markers aldehyde dehydrogenase 1 (ALDH1), CD44, SOX2 and OCT4 in oral dysplastic tissues provides the potential for a more reliable assessment of malignant transformation of oral epithelial dysplasia (OED). Thus, the present study is intended to evaluate the immunohistochemical expression of four different CSC markers ALDH1, CD44, SOX2 and OCT4 in different grades of OED and to investigate the co-expression of these putative stem cell markers in OED. A total of 35 samples of varying grades of OED which included 7 mild, 11 moderate and 17 severe dysplasia samples and 10 samples of normal oral mucosa without dysplasia were used. Four sections each from all 45 samples were stained with ALDH1, CD44, SOX2 and OCT4, respectively, by immunohistochemistry. The acquired data were analyzed and evaluated using the Chi-square test and unpaired t-test and the P < 0.05 was taken significant. ALDH1 and SOX2 expression percentages showed statistically significant differences among study groups (P < 0.05). Statistical comparison of percentage expression of CD44 and OCT4 between OED and normal was nonsignificant (P > 0.05). Co-expression of all four markers was found in 15 cases of OED with none of the normal cases showing co-expression. The expression of CSC markers in OED and normal mucosa differs significantly with co-expression of all four markers located only in dysplastic tissues. Until now, no single protein marker has been able to unequivocally identify the CSCs. Thus, a panel of putative CSC markers will help in identifying the patients with high risk for malignant transformation in OED.

Inhibition of YAP/TAZ-driven TEAD activity prevents growth of NF2-null schwannoma and meningioma.

Schwannoma tumours typically arise on the eighth cranial nerve and are mostly caused by loss of the tumour suppressor Merlin (NF2). There are no approved chemotherapies for these tumours and the surgical removal of the tumour carries a high risk of damage to the eighth or other close cranial nerve tissue. New treatments for schwannoma and other NF2-null tumours such as meningioma are urgently required. Using a combination of human primary tumour cells and mouse models of schwannoma, we have examined the role of the Hippo signalling pathway in driving tumour cell growth. Using both genetic ablation of the Hippo effectors YAP and TAZ as well as novel TEAD palmitoylation inhibitors, we show that Hippo signalling may be successfully targeted in vitro and in vivo to both block and, remarkably, regress schwannoma tumour growth. In particular, successful use of TEAD palmitoylation inhibitors in a preclinical mouse model of schwannoma points to their potential future clinical use. We also identify the cancer stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) as a Hippo signalling target, driven by the TAZ protein in human and mouse NF2-null schwannoma cells, as well as in NF2-null meningioma cells, and examine the potential future role of this new target in halting schwannoma and meningioma tumour growth.

Human Papilloma Virus and Cancer Stem Cell markers in Oral Epithelial Dysplasia-An Immunohistochemical Study.

ObjectivesTo study the correlation between the putative cancer stem cell (CSC) markers aldehyde dehydrogenase 1 (ALDH1), cluster of differentiation 44 (CD44), sex-determining region Y-box 2 (SOX2), and octamer-binding protein 4 (OCT4) and human papilloma virus (HPV) infection using p16, the surrogate marker of HPV in oral epithelial dysplasia (OED) and normal mucosa.MethodsFive sections each from 40 histopathologically diagnosed cases of different grades of OED and 10 cases of normal oral mucosa without dysplasia were immunohistochemically stained with p16, ALDH1, CD44, SOX2, and OCT4, respectively.ResultsExpression of ALDH1 and SOX2 was significantly increased in OED cases, whereas CD44 and OCT4 expression was increased in normal mucosa. P16-positive OED cases showed upregulation of ALDH1 and OCT4 expression as compared to p16-negative cases, while CD44 and SOX2 expression was downregulated in p16-positive OED cases; however, the results were not statistically significant.ConclusionThe present study indicated a suggestive link between p16 and cancer stem cell marker expression in HPV-associated OED, and that p16 has a significant role in CSC progression in OED. This is the first study to evaluate the expression of putative CSC markers in HPV-associated OED. However, low study numbers are a potential limiting factor in this study.

Abstract 5957: Roles for the cancer stem cell marker Aldh1A1 in Merlin null nervous system tumors

Abstract Our lab is interested in the development and growth of schwannoma and meningioma tumors of the nervous system. Approximately 70% of these tumors arise due to loss of the tumor suppressor Merlin. In a mouse model of schwannoma (P0-CRE NF2fl/fl), we observed increased mRNA levels of the cancer stem cell marker Aldehyde dehydrogenase 1A1 (Aldh1A1) in Merlin-null Schwann cells. Immunostaining showed elevated levels of Aldh1A1 protein in this mouse model and in another mouse model (Postn-CRE NF2fl/fl), in which schwannoma tumors arise spontaneously within the vestibulocochlear nerve and dorsal root ganglia of the nervous system. Similarly, staining of human schwannoma samples also showed a strong elevation of Aldh1A1 protein in all tumor cells. Parallel analysis of meningioma tumor samples, in which Merlin loss also occurs, also showed a strong increase of Aldh1A1 protein levels. Western blotting enabled identification of the mechanism by which Merlin loss regulates Aldh1A1. Merlin/TAZ double knockout, but not Merlin/YAP double knockout, sciatic nerves show reduced Aldh1A1 expression. This implicates Hippo signalling through the TAZ effector as the mechanism of Aldh1A1 upregulation both in vitro and in vivo in both tumor types. Chemical inhibition with Aldh1a1-specific inhibitor (NCT-505) or shRNA knockdown of Aldh1A1 in Merlin-null schwannoma and meningioma cells in culture attenuated tumor cell growth, proving Aldh1A1 has a role in tumor cell proliferation; studies using Aldh1A1 null mice to test this in vivo are ongoing. A major target of Aldh1A1 signalling is the regulation of retinoic acid (RA) signalling. We are examining expression and activation of components of RA signalling in both schwannoma and meningioma tumor cells to identify whether this may be of therapeutic use in the future for these two tumor types. In conclusion, the TAZ-dependent upregulation of Aldh1A1 in Merlin-null schwannoma and meningioma tumor cells has a functional role in driving cell proliferation in these two clinically important tumor types. Further work will seek to identify the mechanism by which Aldh1A1 activity contributes to tumor growth. Citation Format: Lily Hillson, Liyam Laraba, Aditya G. Shivane, Philip Edwards, Ganesha Bantukallu, Anton Simeonov, Natalia J. Martinez, Shyh-Ming Yang, David B. Parkinson. Roles for the cancer stem cell marker Aldh1A1 in Merlin null nervous system tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5957.

CSN6\u2013TRIM21 axis instigates cancer stemness during tumorigenesis

BackgroundCancer stem cells (CSCs) are responsible for tumour initiation, metastasis and recurrence. However, the mechanism of CSC formation, maintenance and expansion in colorectal cancer (CRC) remains poorly characterised.MethodsThe role of COP9 signalosome subunit 6 (CSN6) in regulating cancer stemness was evaluated by organoid formation and limited dilution analysis. The role of CSN6–TRIM21–OCT1–ALDH1A1 axis in CSC formation was evaluated in vitro and in vivo. The association of CSN6, TRIM21 and ALDH1A1 expression was validated by a tissue microarray with 267 CRC patients.ResultsThe results showed that CSN6 is critical for sphere formation and maintaining the growth of patient-derived organoids (PDOs). We characterised the role of CSN6 in regulating cancer stemness, which involves the TRIM21 E3 ubiquitin ligase, transcription factor POU class 2 homeobox 1 (OCT1) and cancer stem cell marker aldehyde dehydrogenase 1 A1 (ALDH1A1). Our data showed that CSN6 facilitates ubiquitin-mediated degradation of TRIM21, which in turn decreases TRIM21-mediated OCT1 ubiquitination and subsequently stabilises OCT1. Consequently, OCT1 stabilisation leads to ALDH1A1expression and promotes cancer stemness. We further showed that the protein expression levels of CSN6, TRIM21 and ALDH1A1 can serve as prognostic markers for human CRC.ConclusionsIn conclusion, we validate a pathway for cancer stemness regulation involving ALDH1A1 levels through the CSN6–TRIM21 axis, which may be utilised as CRC molecular markers and be targeted for therapeutic intervention in cancers.

Disruption of IFN-I Signaling Promotes HER2/Neu Tumor Progression and Breast Cancer Stem Cells.

Type I interferon (IFN-I) is a class of antiviral immunomodulatory cytokines involved in many stages of tumor initiation and progression. IFN-I acts directly on tumor cells to inhibit cell growth and indirectly by activating immune cells to mount antitumor responses. To understand the role of endogenous IFN-I in spontaneous, oncogene-driven carcinogenesis, we characterized tumors arising in HER2/neu transgenic (neuT) mice carrying a nonfunctional mutation in the IFNI receptor (IFNAR1). Such mice are unresponsive to this family of cytokines. Compared with parental neu+/- mice (neuT mice), IFNAR1-/- neu+/- mice (IFNAR-neuT mice) showed earlier onset and increased tumor multiplicity with marked vascularization. IFNAR-neuT tumors exhibited deregulation of genes having adverse prognostic value in breast cancer patients, including the breast cancer stem cell (BCSC) marker aldehyde dehydrogenase-1A1 (ALDH1A1). An increased number of BCSCs were observed in IFNAR-neuT tumors, as assessed by ALDH1A1 enzymatic activity, clonogenic assay, and tumorigenic capacity. In vitro exposure of neuT+ mammospheres and cell lines to antibodies to IFN-I resulted in increased frequency of ALDH+ cells, suggesting that IFN-I controls stemness in tumor cells. Altogether, these results reveal a role of IFN-I in neuT-driven spontaneous carcinogenesis through intrinsic control of BCSCs. Cancer Immunol Res; 6(6); 658-70. ©2018 AACR.

Clinicopathological characteristics and prognostic value of the cancer stem cell marker ALDH1 in ovarian cancer: a meta-analysis.

BackgroundThe clinicopathological and prognostic values of the cancer stem cell marker aldehyde dehydrogenase 1 (ALDH1) in ovarian cancer (OC) remain unknown. The aim of our meta-analysis was to evaluate ALDH1’s association with clinicopathological characteristics and its prognostic significance in patients with OC.Materials and methodsPubMed, Embase, and China Biology Medicine were systematically searched for eligible studies (up to October 2017). Pooled odds ratios (ORs) or hazard ratios (HRs) with 95% CIs were used to evaluate the association of ALDH1 expression with clinicopathological features and survival outcomes.ResultsA total of 17 papers (18 studies) that included 2,531 patients with OC were analyzed. The results showed a significant association between increasing ALDH1 expression and International Federation of Gynecology and Obstetrics stage (OR 2.02, 95% CI 1.16–3.52), lymph node metastasis (OR 1.91, 95% CI 1.01–3.61), and distant metastasis (OR 5.43, 95% CI 1.44–20.42) in OC. However, no significant correlation was found between increasing ALDH1 expression and age (OR 0.90, 95% CI 0.25–3.28), tumor size (OR 1.13, 95% CI 0.75–1.71), tumor location (OR 0.69, 95% CI 0.22–2.13), ascite status (OR 0.74, 95% CI 0.49–1.11), resistance status (OR 0.70, 95% CI 0.14–3.51), or clinicopathological type (OR 1.14, 95% CI 0.69–1.86). Moreover, a high ALDH1 expression was significantly associated with overall survival (HR 1.56, 95% CI 1.21–2.02) but not with disease-free survival (HR 1.38, 95% CI 0.99–1.93).ConclusionThe meta-analysis indicates that increasing ALDH1 predicts poor prognosis and clinicopathological characteristics in OC. Future studies are needed to explore tailored treatments that directly target ALDH1 for the improvement of survival in OC.

Impact of Cystic Fibrosis Transmembrane Conductance Regulator on Malignant Properties of KRAS Mutant Lung Adenocarcinoma A549 Cells

背景与目的肺癌发病率逐年上升，有必要寻找新型的治疗靶点，而最新研究发现囊状纤维化跨膜转导调节子（cystic fibrosis transmembrane conductance regulator, CFTR）与多种肿瘤的发生和恶性转化有关。本研究探讨CFTR对肺癌A549细胞恶性特性的影响。方法应用CCK8细胞增殖实验、细胞划痕实验、Transwell细胞侵袭实验以及克隆形成实验等方法分别检测CFTR的表达对非小细胞肺癌A549细胞的增殖、迁移、侵袭等细胞恶性特性的影响。同时通过免疫印迹（Western blot）分析CFTR基因表达对肿瘤干细胞相关转录因子表达的影响。结果过表达CFTR基因显著抑制A549细胞的增殖、迁移、侵袭和克隆形成等肿瘤恶性特征，而RNA干扰A549细胞CFTR的表达导致细胞上述特征的明显增强。免疫印迹实验进一步发现CFTR基因过表达抑制A549细胞中干细胞相关转录因子SOX2和OCT3/4，以及细胞表面CD133蛋白的表达；相反，RNA干扰A549细胞中CFTR基因的表达增加SOX2、OCT4和CD133的表达。然而，免疫印迹和流式细胞术发现CFTR基因表达对A549细胞肺癌干细胞标志乙醛脱氢酶1的表达和阳性细胞数量无显著影响。结论CFTR基因在肺癌A549细胞中具有抑制细胞恶性特征的作用，提示其可能是肺腺癌治疗的一个新的靶点，但其对其他肺腺癌细胞的作用与分子机制还有待进一步研究。

A prospective study of association of cancer stem cell marker aldehyde dehydrogenase 1 with clinicopathological profile in lung carcinoma patients.

In India, lung carcinoma is the fifth-most common tumor and second-most common tumor in the males as per the Indian Council of Medical Research registry of 2002. It has been seen that ALDH1 expression in non-small cell lung cancer (NSCLC) and the presence of marker was linked to a more tumorigenic potential in the in vivo assessment and shorter disease-free survival in NSCLC patients with platinum treatment. Hence, our objective was to detect association of cancer stem cell (CSC) marker aldehyde dehydrogenase 1 (ALDH1) with clinicopathological profile in lung carcinoma patients. This is a Pilot study. It was a Pilot study where biopsies from 55 fresh previously untreated lung cancer patients visiting the Pulmonary Medicine Department of Era's Lucknow Medical College and Hospital Lucknow and King George's Medical University were taken for 18 months November 2014-April 2016, after taking proper informed consent from them. Paraffin blocks were taken and stained by hematoxylin and eosin (Sigma) to make the histopathological diagnosis and immunohistochemistry was done for detection of CSC marker ALDH1 (Daco). The statistical analysis was done using Statistical Package for Social Sciences Version 15.0 Statistical Analysis Software. The values were represented in number (%) and mean ± standard deviation. Expression of stem cell marker ALDH1 with the staging of the tumor was observed in 62.5% of Stage I, 80% of Stage II, 94.1% of Stage III, and 100% of Stage IV cases. Statistically, there was a significant association between ALDH1expression and stage of disease (P < 0.001). Diagnostic efficacy of ALDH1 expression in the detection of any positive clinical stage, it was found to be 88.6% sensitive and 90.9% specific. Strong ALDH1 expression correlates with higher stage of lung carcinoma making it a prognostic marker needing in-depth study.

Differences in expression of the cancer stem cell marker aldehyde dehydrogenase 1 among estrogen receptor-positive/human epidermal growth factor receptor type 2-negative breast cancer cases with early, late, and no recurrence

BackgroundThe significance of the expression of aldehyde dehydrogenase 1 (ALDH1), a cancer stem cell marker, for predicting the recurrence of estrogen receptor (ER)-positive/human epidermal growth factor receptor type 2 (HER2)-negative breast cancer is still poorly understood. The value of ALDH1 in predicting the time of recurrence remains unknown.MethodsIn total, 184 patients with early distant recurrence, 134 patients with late distant recurrence, and 321 control patients without recurrence for more than 10 years after starting initial treatment for ER-positive/HER2-negative breast cancer, registered in 9 institutions, were analyzed. We assessed relationships between ALDH1 and other clinicopathological features, and ALDH1 expression was compared among the three groups. The relationship between ALDH1 expression and overall survival after recurrence was also evaluated in each group.ResultsThe rates of ALDH1 expression positivity (more than 1 %) in the early, late, and no recurrence groups were 18.4 %, 13.4 %, and 8.4 %, respectively. ALDH1 expression correlated significantly with lymph node metastases (p = 0.048) and the Ki-67 labeling index (p < 0.001) in the early recurrence group. Multivariate analysis revealed ALDH1 expression to be significantly higher in the early recurrence group than in the no recurrence group (adjusted OR 2.140, 95 % CI 1.144–4.003, p = 0.016). Moreover, there was a significant difference in ALDH1 expression between the early and no recurrence groups receiving adjuvant endocrine therapy and chemotherapy (adjusted OR 4.625, 95 % CI 1.881–12.474, p < 0.001). However, there was no difference in ALDH1 expression between the late and no recurrence groups in univariate analysis (OR 1.507, 95 % CI 0.738–2.998, p = 0.253). In multivariate analysis, ALDH1 was not a factor independently predicting overall survival after the detection of recurrence (adjusted OR 1.451, 95 % CI 0.985–2.085, p = 0.059).ConclusionsAmong patients with ER-positive/HER2-negative breast cancer, ALDH1 expression was more common in those with early recurrence, and this expression was found to be associated with a more aggressive breast cancer phenotype than that in the patients without recurrence. Further study is needed to clarify the prognostic significance of the heterogeneity of cancer stem cells and to confirm their role in resistance to chemotherapy.

Abstract P2-07-07: Prostaglandin E receptor 2 (EP2) regulates breast cancer stem-cell like property and promotes epithelial-mesenchymal transition

Abstract Background: Presence of cancer stem-like cells (CSCs) is the main obstacle for poor treatment response and mortality in breast cancer patients. Prostaglandin E receptors have been reported to play a role in epithelial-mesenchymal transition (EMT) and metastasis, however, the contribution on cancer stem cell compartment remains unstudied. Methods: Human xenograft breast cancer model was used to study the expression of EP receptors during cancer development. Construction of stable EP2-expression cells was used to study tumorigenesis and characterization of EP2 receptor. Functional role of EP2 receptor on cell proliferation, flow cyometry, invasion and EMT gene expression array were performed in transfected cells. Expression of EP2 receptor was compared in primary tumor tissues by immunostaining and real-time PCR. Results: EP2 receptor was predominantly expressed in animal tissues during cancer development, as well as in human primary tumor tissues. In mouse xenograft model, MB-231-EP2 clone developed a more aggressive tumor with a larger tumor size and showed a significant increase in cancer stem cell marker aldehyde hydrogenase (ALDH1) expression. In vitro study, MB-231-EP2 clone increased colony formation capacity and S-phase entry by the regulation of E-cadherin, TWIST1 and ALDH1. Importantly, we found that Twist1 expression level was higher in breast cancer patients than healthy controls and was associated with ALDH1 expression. Conclusions: These findings implicated that EP2 receptor was crucial to nurture CSC phenotype and promote tumorigenesis in breast cancer. Blocking of EP2 might be a potential therapeutic strategy to improve treatment response for breast cancer patients. Citation Format: Vivian Y Shin, Man T Siu, John C Ho, Isabella Cheuk, Jiawei Chen, Ava Kwong. Prostaglandin E receptor 2 (EP2) regulates breast cancer stem-cell like property and promotes epithelial-mesenchymal transition [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 P2-07-07.

P22 Cancer stem cell marker aldehyde dehydrogenase 1 expression in oral squamous cell carcinoma – An immunohistochemistry study

Background Aldehyde dehydrogenase 1 expression (ALDH1) has been shown to be a cancer stem cell marker. This study aimed to evaluate the expression of ALDH1 in different grades of oral squamous cell carcinoma (OSCC), and to correlate expression with pathological outcomes such as tumor stage, lymph node and distant metastases. Methods Tissue sections cut from 45 archival blocks of OSCC were stained using an ALDH1 monoclonal antibody and expression was quantified by area percent of immunostaining and staining optical density using an image analyzer computer system. ANOVA test and Tukey’s post hoc test were used to evaluate statistical significance of difference between different grades or stages. Unpaired Student’s t test was used to evaluate significance of difference between lesions with and without lymph node metastasis. Results ALDH1 expression varied based on tumor histological grade and clinical stage, with significantly greater mean area percent of immunoexpression recorded in poorly differentiated lesions ( P Conclusions ALDH1 is involved in development of oral SCC. Its expression increases in more aggressive lesions suggesting a role in promoting the invasive and metastatic potential. Quantification based on area percent of immunoexpression may yield more accurate findings compared to evaluation of optical density.

Nuclear DICKKOPF-1 as a biomarker of chemoresistance and poor clinical outcome in colorectal cancer.

Sporadic colorectal cancer (CRC) insurgence and progression depend on the activation of Wnt/β-catenin signaling. Dickkopf (DKK)-1 is an extracellular inhibitor of Wnt/β-catenin signaling that also has undefined β-catenin-independent actions. Here we report for the first time that a proportion of DKK-1 locates within the nucleus of healthy small intestine and colon mucosa, and of CRC cells at specific chromatin sites of active transcription. Moreover, we show that DKK-1 regulates several cancer-related genes including the cancer stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) and Ral-binding protein 1-associated Eps domain-containing 2 (REPS2), which are involved in detoxification of chemotherapeutic agents. Nuclear DKK-1 expression is lost along CRC progression; however, it remains high in a subset (15%) of CRC patients (n = 699) and associates with decreased progression-free survival (PFS) after chemotherapy administration and overall survival (OS) [adjusted HR, 1.65; 95% confidence interval (CI), 1.23-2.21; P = 0.002)]. Overexpression of ALDH1A1 and REPS2 associates with nuclear DKK-1 expression in tumors and correlates with decreased OS (P = 0.001 and 0.014) and PFS. In summary, our findings demonstrate a novel location of DKK-1 within the cell nucleus and support a role of nuclear DKK-1 as a predictive biomarker of chemoresistance in colorectal cancer.

The cancer stem cell marker aldehyde dehydrogenase is required to maintain a drug-tolerant tumor cell subpopulation.

Selective kinase inhibitors have emerged as an important class of cancer therapeutics, and several such drugs are now routinely used to treat advanced-stage disease. However, their clinical benefit is typically short-lived because of the relatively rapid acquisition of drug resistance following treatment response. Accumulating preclinical and clinical data point to a role for a heterogeneous response to treatment within a subpopulation of tumor cells that are intrinsically drug-resistant, such as cancer stem cells. We have previously described an epigenetically determined reversibly drug-tolerant subpopulation of cancer cells that share some properties with cancer stem cells. Here, we define a requirement for the previously established cancer stem cell marker ALDH (aldehyde dehydrogenase) in the maintenance of this drug-tolerant subpopulation. We find that ALDH protects the drug-tolerant subpopulation from the potentially toxic effects of elevated levels of reactive oxygen species (ROS) in these cells, and pharmacologic disruption of ALDH activity leads to accumulation of ROS to toxic levels, consequent DNA damage, and apoptosis specifically within the drug-tolerant subpopulation. Combining ALDH inhibition with other kinase-directed treatments delayed treatment relapse in vitro and in vivo, revealing a novel combination treatment strategy for cancers that might otherwise rapidly relapse following single-agent therapy.

Prognostic value of cancer stem cell marker aldehyde dehydrogenase in ovarian cancer: a meta-analysis.

ObjectiveAldehyde dehydrogenase (ALDH) has recently been reported as a marker of cancer stem-like cells in ovarian cancer. However, the prognostic role of ALDH in ovarian cancer still remains controversial. In this study, we aimed to evaluate the association between the expression of ALDH and the outcome of ovarian cancer patients by performing a meta-analysis.MethodsWe systematically searched for studies investigating the relationships between ALDH expression and outcome of ovarian cancer patients. Only articles in which ALDH expression was detected by immunohistochemical staining were included. A meta-analysis was performed to generate combined hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) and disease-free survival (DFS).ResultsA total of 1,258 patients from 7 studies (6 articles) were included in the analysis. Our results showed that high ALDH expression in patients with ovarian cancer was associated with poor prognosis in terms of Os (HR, 1.25; 95% CI, 1.07-1.47; P = 0.005) and DFS (HR, 1.58; 95% CI, 1.00-2.49; P = 0.052), though the difference for DFS was not statistically significant. In addition, there was no evidence of publication bias as suggested by Begg’s and Egger’s tests (Begg’s test, P = 0.707; Egger’s test, P = 0.355).ConclusionThe present meta-analysis indicated that elevated ALDH expression was associated with poor prognosis in patients with ovarian cancer.

Inhibition Of Wnt Signaling In Chronic Lymphocytic Leukemia Has Synergistic Cytotoxicity With Ibrutinib

The Wnt pathway plays a major role in early embryonic development and in various cancers. We found that CLL cells have activated Wnt-signaling (Proc Natl Acad SciUSA 2004, PMID: 14973184) and express genes commonly associated with B-cell progenitors or stem cells, especially the Wnt factor-related genes such as LEF1, Wnt16, and Frizzled3 (FZD3). Also, compared to normal B lymphocytes, CLL cells express high levels of the putative cancer stem cell marker Aldehyde Dehydrogenase (ALDH), especially those CLL cells with high-risk prognostic features (Leuk and Lymph, 2013, PMID 22784365) and are highly sensitive to inhibitors of Wnt signaling (Proc Natl Acad SciUSA 2004, PMID: 3156152). Finally, next generation DNA sequencing studies have identified mutations in 12 different Wnt pathway genes in 15-20% of CLL patients. Collectively, the results of these studies imply that Wnt-signaling may be an excellent target for developing effective novel therapies for patients with CLL (Oncotarget 2011, PMID: 21860066).We compared different classes of Wnt inhibitors identified by screening of natural compound and small molecule libraries for cytotoxicity in primary leukemic cells from patients with CLL. Among all the Wnt inhibitors tested, Salinomycin and Agelastatin (naturally occurring compounds targeting LRP5/6 degradation or LEF1 down-regulation as previously reported by our groups) consistently showed dose dependent cytotoxicity at concentrations lower than 1 µM. In contrast, small molecule Wnt inhibitors targeting more proximal elements of the Wnt pathway, porcupine (Wnt-C59) and tankyrase, (XAV-939) had little direct effect on in vitro CLL cell viability even at 10 µM.The Wnt inhibitors were also utilized as tool compounds to evaluate the effect of combined inhibition of the Wnt pathway and other pathways. Interestingly, we identified synergistic activity between Wnt inhibitors and other inhibitors, including Ibrutinib and Idelalisib. By colorimetric and flow cytometry assays, we demonstrated that significant cell death was induced with combinations of the agents at concentrations at which little or no cytotoxicity was seen with either agent alone. The studies further demonstrate that the Wnt pathway is a viable target for the treatment of CLL and may potentiate other emerging CLL therapies. Disclosures:Kipps:Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceuticals: Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Aldehyde dehydrogenase 1 expression correlated with malignant potential of oral lichen planus

Oral lichen planus (OLP) is a potentially malignant disorder associated with an increased risk of oral squamous cell carcinoma (OSCC). The objective of this study was to determine protein expression of cancer stem cell marker aldehyde dehydrogenase 1 (ALDH1) in a series of patients with OLP and evaluate the correlation between ALDH1 expression and the risk of progression to OSCC. In a retrospective study, ALDH1 expression was determined using immunohistochemistry in samples from 101 patients with OLP who received a mean follow-up of 5 years, including 89 patients with untransformed OLP that did not develop into OSCC and 12 patients with malignant transformed OLP that had developed into OSCC. Analysis of 10 cases of normal oral mucosa and 6 cases of postmalignant OSCC form previously diagnosed OLP was also performed. The results showed that ALDH1 expression was observed in 27 (30.3%) of 89 cases of untransformed OLP and in 8 (66.7%) of 12 cases of transformed OLP (P = .021). Aldehyde dehydrogenase 1 was not expressed in normal oral mucosa, but it overexpressed in the 6 cases (100%) of OSCC. Multivariate analysis revealed that ALDH1 expression was significantly associated with a 6.71-fold (95% confidence interval, 1.64-27.42; P = .008) increased risk of malignant transformation. Collectively, ALDH1 expression was significantly associated with malignant transformation in a large series of patients with OLP. Our findings suggested that ALDH1 expression may identify a subgroup of a higher risk of malignant transformation of OLP.

ALDH1 expression indicates chemotherapy resistance and poor outcome in node-negative rectal cancer

The cancer stem cell marker aldehyde dehydrogenase 1 (ALDH1) associates with treatment resistance and adverse outcome in several human cancers. We studied ALDH1 expression in rectal cancer, with special emphasis on its association with treatment response and disease outcome. Immunohistochemical staining for ALDH1 was conducted for 64 biopsies and 209 operative samples from rectal cancer patients treated with short- (n = 89) or long-course (n = 46) (chemo)radiotherapy plus surgery, or with surgery only (n = 74). The staining results were compared to clinicopathological variables, tumor regression grade (TRG) and disease outcome. Nuclear β-catenin expression pattern was analyzed from 197 operative samples. Positive ALDH1 expression was present in 149 operative samples (71%), correlating with deficient nuclear β-catenin regulation (P = .018). In a pairwise comparison of respective biopsy and operative samples, ALDH1 expression remained stable or increased after preoperative (chemo)radiotherapy in most of the cases, while it decreased in few cases only (P = .02 for positive/negative category; P <.001 for intensity). ALDH1 expression did not, however, relate to tumor regression grade. In node-negative rectal cancer, ALDH1 expression was an independent predictor of short disease-free and disease-specific survival (P = .044; P = .049), specifically among patients treated with adjuvant chemotherapy. We conclude that ALDH1 associates with deregulated β-catenin signaling, supporting the role of ALDH1 in rectal cancer stemness. ALDH1 expression relates to poor outcome in early stage rectal cancer, a group where new prognostic tools are particularly needed, and may indicate chemo- and radioresistance.

Tumour budding and the expression of cancer stem cell marker aldehyde dehydrogenase 1 in nasopharyngeal carcinoma

To detect the prognostic significance of tumour budding and its expression of aldehyde dehydrogenase 1 (ALDH1) in nasopharyngeal carcinoma (NPC). Tumour budding was investigated in 105 patients with NPC by immunohistochemistry for pan-cytokeratin (AE1/AE3). The intensity of budding correlated strongly with T classification (P=0.008), lymphatic invasion (P<0.001), vascular invasion (P=0.029), lymph node metastasis (P < 0.001), and clinical stage (P=0.010). Univariate analysis revealed that patients with high budding grade had poorer survival than those with low grade (P=0.002). Multivariate analysis showed that tumour budding was an independent predictor of survival (P=0.001). Furthermore, budding cells showed high-level expression of the cancer stem cell (CSC) marker ALDH1. Budding cells with high-level ALDH1 expression contributed to several aggressive behaviours and poor survival (P=0.000). We describe, for the first time, the presence of tumour budding and its correlation with aggressive tumour behaviour and poor patient survival in NPC. The degree of tumour budding could be a valuable predictive factor in NPC. In addition, we show, also for the first time, that budding cells in NPC might possess the invasive and metastatic properties of CSCs.

Synergistic anti-cancer mechanisms of curcumin and paclitaxel for growth inhibition of human brain tumor stem cells and LN18 and U138MG cells

Glioblastoma, the deadliest brain tumor in humans, responds poorly to conventional chemotherapeutic agents because of existence of highly chemoresistant human brain tumor stem cells (HBTSC). An effective therapeutic strategy is urgently needed to target HBTSC as well as other glioblastoma cells. We explored synergistic efficacy of a low dose of curcumin (CCM) and a low dose of paclitaxel (PTX) in HBTSC and human glioblastoma LN18 (p53 mutant and PTEN proficient) and U138MG (p53 mutant and PTEN mutant) cells. The highest expression of the cancer stem cell markers aldehyde dehydrogenase 1 (ALDH1) and CD133 occurred in HBTSC when compared with LN18 and U138MG cells. Combination of 20μM CCM and 10nM PTX worked synergistically and more effectively than either drug alone in decreasing viability in all cells. Combination of CCM and PTX was highly effective in inducing both morphological and biochemical features of apoptosis. Apoptosis required activation of caspase-8, cleavage of Bid to tBid, increase in Bax:Bcl-2 ratio, and mitochondrial release of cytochrome c, Smac, and apoptosis-inducing factor (AIF). Phosphorylation of Bcl-2 following combination therapy appeared to promote Bax homodimerization and mitochondrial release of pro-apoptotic factors into the cytosol. Increases in activities of cysteine proteases confirmed the completion of apoptotic process. Combination therapy inhibited invasion of cells, reduced expression of survival and proliferation factors and also angiogenic factors, and prevented HBTSC, LN18, and U138MG cells from promoting network formation. Collectively, the combination of CCM and PTX worked as a promising therapy for controlling the growth of HBTSC and other glioblastoma cells.