Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus

Abstract: Background: Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. Objective: This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Method: Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. Results: The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. Limitations of the study: This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. Conclusions: The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further studies are needed for introducing aldehyde dehydrogenase as a prognostic indicator in certain lesions.

Low Retinal Dehydrogenase 1 (RALDH1) Level in Prepubertal Boys with Autism Spectrum Disorder: A Possible Link to Dopamine Dysfunction?

OBJECTIVE: Retinal dehydrogenase 1 (RALDH1) is a cytosolic enzyme which acts both as a source of retinoic acid (RA) and as a detoxification enzyme. RALDH1 has key functions in the midbrain dopaminergic system, which influences motivation, cognition, and social behavior. Since dopamine has been increasingly linked to autism spectrum disorder (ASD), we asked whether RALDH1 could contribute to the autistic phenotype. Therefore, we investigated for the first time the levels of RALDH1 in autistic patients. To further assess the detoxification function of RALDH1, we also explored 4-hydroxynonenal protein adducts (4-HNE PAs) and reduced glutathione (GSH) levels. Moreover, considering the effect of testosterone on RALDH1 expression, we measured the second to fourth digit ratio (2D:4D ratio) for both hands, which reflects exposure to prenatal testosterone. METHODS: Male patients with ASD (n=18; age, 62.9±4.3 months) and healthy controls (n=13; age, 78.1±4.9 months) were examined. Erythrocyte RALDH1, serum 4-HNE PAs and erythrocyte GSH levels were measured using colorimetric assays, and digit lengths were measured using digital calipers. RESULTS: We found significantly lower (−42.9%) RALDH1 levels in autistic patients as compared to controls (p=0.032). However, there was no difference in 4-HNE PAs levels (p=0.368), GSH levels (p=0.586), or 2D:4D ratios (p=0.246 in the left hand, p=0.584 in the right hand) between healthy controls and autistic subjects. CONCLUSION: We concluded that a subset of autistic patients had a low RALDH1 level. These results suggest that low RALDH1 levels could contribute to the autistic phenotype by reflecting a dopaminergic dysfunction.

Expression of ALDH1, CXCR4 and E-cadherin in castric carcinoma and their roles in lymphatic metastasis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of ALDH1, CXCR4 and E-cadherin in gastric carcinoma and their roles in lymphatic metastasis.</p><p><b>METHODS</b>Surgical specimens from 127 cases of gastric carcinoma were examined for expressions of ALDH1, CXCR4 and E-cadherin immuohistochemistry with 60 adjacent tissues as control. The associations of ALDH1, CXCR4 and E-cadherin with the clinicopathological pfeatures, 5-year survival rate and lymph node metastasis of the patients were analyzed.</p><p><b>RESULTS</b>ALDH1, CXCR4 and E-cadherin were positive in 57.5% (73/127), 63.8% (81/127), and 36.2% (46/127) of the gastric carcinoma tissues, respectively, showing significant differences from the rates in the adjacent tissues (P<0.05). The expression of ALDH1 was significantly correlated with TNM stage and lymph node metastasis (P<0.05), CXCR4 was significantly correlated with the invasion depth, differentiation, TNM stage and lymph node metastasis of the tumor (P<0.05), and E-cadherin was significantly correlated with the invasion depth, differentiation and lymph node metastasis (P<0.05). The positivity rates of ALDH1, CXCR4 and E-cadherin were higher in cases with lymph node metastasis than in those without metastasis. E-cadherin expression was inversely correlated with ALDH1 and CXCR4 expression, and the latter two were positively correlated (P<0.001). Overexpressions of ALDH1 and CXCR4 and a decreased expression of E-cadherin were all related to a poor prognosis of the patients (P<0.05). The expressions ofALDH1, CXCR4 and E-cadherin were all independent prognostic factors of gastric carcinoma.</p><p><b>CONCLUSION</b>The expressions of ALDH1, CXCR4 and E-cadherin are associated with the invasion, metastasis and prognosis of gastric carcinoma, and their combined detection provides important evidence for predicting the progression and prognosis of gastric carcinoma.</p>

Prevalencia de intento de suicidio adolescente y factores de riesgo asociados en una comuna rural de la provincia de Concepción / Suicide attempts among Chilean adolescents

Background: Suicide mortality rates are increasing among teenagers. Aim: To study the prevalence and predictive factors of suicide attempts among Chilean adolescents. Material and Methods: A random sample of 195 teenagers aged 16 ± 1 years (53% males) answered an anonymous survey about their demographic features, substance abuse, the Osaka suicidal ideation questionnaire, Smilksten familial Apgar. Beck hopelessness scale, Beck depression scale and Coppersmith self-esteem inventory. Results: Twenty five percent of respondents had attempted suicide at least in one occasion during their lives. These attempts were significantly associated with female gender, absent parents, family dysfunction, drug abuse, smoking, low self-esteem, hopelessness, depression and recent suicidal ideation. A logistic regression analysis accepted female gender, smoking and recent suicidal ideation as significant independent predictors of suicide attempt. Conclusions: Suicide attempted is common among teenagers and its predictors are female sex, smoking and previous suicidal ideation.

Verification of ALDH activity as a biomarker in colon cancer stem cells-derived HT-29 cell line

Background: Recent evidence has suggested that epithelial cancers including colorectal cancer [CRC] have driven by a small population of self-renewing, multi-potent cells termed cancer stem cells [CSCs] which could be responsible for recurrence of cancer. Aldehyde dehydrogenase 1 [ALDH1] activity has used as a functional stem cell biomarker to isolate CSCs in different cancers such as colorectal cancer

Objectives: The main aim of this research was to determine the utility of ALDH1 activity along with CD44 and EPCAM in identifying stem cell-like cells in human HT-29 colonic adenocarcinoma cell line

Materials and Methods: In this experimental study, colon CSCs biomarkers including CD44, EPCAM and ALDH1 in colonospheres and parent cells have analyzed by flow cytometry. The expression levels of stemness genes in spheroid and parental cells have investigated using SYBR Green real-time PCR. In addition, in vivo xenografts assay has performed to determine tumorigenic potential of tumor spheroid cells in nude mice

Results: According to results, over 92% of spheroids were CD44+/EpCAM+, while parent cells only have expressed 38% of CD44/EpCAM biomarkers [P < 0.001]. Controversially, ALDH activity was about 2-fold higher in the parent cells than spheroid cells [P < 0.05]. In comparison with the parental cells, expression levels of ''stemness'' genes, like Sox2, Oct4, Nanog, C-myc, and Klf4 have significantly increased in colonosphere cells [P < 0.05]. Further, administration of 2500 spheroids could be sufficient to initiate tumor growth in nude mice, while 1x106 of parental cells has needed to form tumor

Conclusions: For the first time, we have shown that colonospheres with low ALDH1 activity has indicated increased tumorigenic potential and stemness properties. So, it hasn't seemed that ALDH1 could become a useful biomarker to identify CSCs population in HT-29 cell line

Liver cancer stem cells are selectively enriched by low-dose cisplatin

Accumulating evidence has indicated the importance of cancer stem cells in carcinogenesis. The goal of the present study was to determine the effect of low-dose cisplatin on enriched liver cancer stem cells (LCSCs). Human hepatoblastoma HepG2 cells were treated with concentrations of cisplatin ranging from 1 to 5 μg/mL. Cell survival and proliferation were evaluated using a tetrazolium dye (MTT) assay. LCSCs were identified using specific markers, namely aldehyde dehydrogenase-1 (ALDH1) and CD133. The percentage of ALDH1+ or CD133+ cells was examined by flow cytometric analysis. The expression of ALDH1 and/or CD133 in HepG2 cells was determined by immunocytochemical analysis. Low-dose cisplatin treatment significantly decreased cell survival in HepG2 cells after 24 or 72 h. However, the percentage of LCSCs in the surviving cells was greatly increased. The percentage of ALDH1+ or CD133+ cells was increased in a time- and dose-dependent manner after treatment with 1-4 μg/mL cisplatin, whereas 5 μg/mL cisplatin exposure slightly reduced the number of positive cells. These findings indicate that low-dose cisplatin treatment may efficiently enrich the LCSC population in HepG2 cells.

Sphere-forming-like cells (squamospheres) with cancer stem-like cell traits from VX2 rabbit buccal squamous cell carcinoma / 国际口腔科学杂志·英文版

Previous studies have demonstrated that spheroid type cells grown under suspension culture conditions have cancer stem cell (CSC) traits in a number of cancers, but this phenomenon has not yet been reported in the VX2 rabbit oral cancer model. Hence, this study aimed to study the spheroid cells from VX2 rabbit buccal squamous cell carcinomas (SCCs) and assess their CSC characteristics. Five adult male New Zealand white outbred rabbits were used to generate VX2 rabbit buccal SCC. Sphere-forming cell culture was performed for the VX2 rabbit buccal SCC specimens. The self-renewal capability; cluster of designation (CD) 44, CD133, acetaldehyde dehydrogenase 1 (ALDH1), B cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1), Nestin, octamer-binding transcription factor 4 (Oct4) and reduced expression protein-1 (Rex-1) expression with reverse transcription-polymerase chain reaction (RT-PCR); chemoresistance to cisplatin and 5-fluorouracil; and in vivo tumorigenicity of spheroid cell transplantation in nude mice were evaluated to determine the CSC characteristics of the resulting spheroid cells. We successfully obtained spheroid cells from the VX2 rabbit OSCC tissues. The spheroid cells exhibited CSC traits, including the expression of CSC and stem cell markers (CD44, Bmi-1, Nestin, Oct4 and Rex-1), capacity to generate new spheroid colonies within 1 week of reseeding from single-dissociated spheroid cells, chemoresistance capacity and generation of tumour xenografts (with histological features resembling those of the original VX2 rabbit buccal SCC) from the transplantation of 10(3) undifferentiated spheroid cells into nude mice. In summary, we demonstrated that spheroid cells with CSC cell traits can be derived from VX2 rabbit buccal SCCs, indicating that this animal cancer model is applicable for studying CSCs in human oral cancers.

CD133(+) Colo205 colorectal cancer cells express high levels of ALDH1 in serum-free culture / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression pattern of CD133 and ALDH1 in colorectal cancer cells line Colo205 cultured in serum-free medium (SFM) containing recombinant human epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF).</p><p><b>METHODS</b>Colo205 cells were cultured in serum-free medium (SFM) containing human recombinant EGF and bFGF or in serum-supplemented medium (SSM). The expression of CD133 was analyzed in both groups, and CD133(+) and CD133(-) cells sorted from the SFM group using flow cytometry and observed microscopically for their growth status. The expression of CD133 and ALDH1 in CD133(+) cells and CD133(-) cells was detected by immunofluorescence assay. CD133(+) cells and CD133(-) cells were then injected subcutaneously into NOD/SCID mice and the expression of ALDH1 in the tumor tissues was detected by immunohistochemistry.</p><p><b>RESULTS</b>The cells in SFM group showed a significantly higher percentage of CD133(+) cells than those in SSM group (P<0.05). In SFM, CD133(+) cells were capable of forming tumor spheres while CD133(-) cells could not; CD133(+)cells strongly expressed CD133 and ALDH1 and CD133(-) cells did not. In mice, tumors generated by CD133(+) cells, but not by CD133(-) cells, positively expressed ALDH1.</p><p><b>CONCLUSIONS</b>CD133(+) Colo205 colorectal cancer cells in SFM containing human recombinant EGF and bFGF can form tumor spheres and strongly express ALDH1. ALDH1 may be one of the candidate markers of colorectal cancer stem cells.</p>

Expression of aldehyde dehydrogenase 1 in colon cancer

OBJECTIVE@#To study the expression of ALDH1 in colon cancer and its clinical significance.@*METHODS@#The expression of ALDH1 was examined in 98 surgical specimens of primary colonic carcinoma and 15 normal colon tissues with immunohistochemistry method. The correlations of the expression with clinicopathological parameters and prognosis of colon cancer were analyzed.@*RESULTS@#The positive rate of expression of ALDH1 was 76.5% (75/98) in the cancer tissues and 13.3% (2/15) in normal colon tissues. There were an obvious statistical difference (P<0.05) between the two groups. The ALDH1 expression was significantly correlated with the histological grade, TNM stages and lymph node metastasis in colon cancer (P<0.05). It was also related with patients' survival time, those with positive expressions had a poor prognosis (P<0.05).@*CONCLUSIONS@#The results suggeste that the overexpression of ALDH1 plays important roles in proliferation and progression in colon cancer, the ALDH1 may be a valuable marker to predict the biological behavior and trend of metastasis of colon cancer.

Research progresses in synthetic biology of artemisinin / 药学学报

Abstract: The first-line drug artemisinin is widely used against malaria. Commercially available artemisinin is extracted from plants. However, the lack of sufficient raw material, artemisinin and the cost associated with the drug's manufacture have limited the supply of ACT to most malaria sufferers in the Developing World. As such, it is important to develop a low cost, fine to environment and high-quality method to supply sufficient and reliable quantities of artemisinin in the future. The field of synthetic biology, which utilizes cell factories to manipulate microbial metabolism to enhance the production of artemisinin and its intermediates, has a particularly strong impact by providing new platforms for chemical production. After a brief introduction of the artemisinin biosynthetic pathway, the present review focuses on the introduction of artemisinin biosynthetic genes, such as the genes encoding amorpha-4, 11-diene monooxygenase, NADPH: cytochrome P450 oxidoreductase, artemisinic aldehyde delta 11(13) reductase and aldehyde dehydrogenase. The review also addresses general considerations for potential contributions of synthetic biology to artemisinin production, with an emphasis on factors influencing interest compounds production in chassis cells.

Effect of ultraviolet radiation on ALDH1 expression in human lens epithelial cells / 中南大学学报(医学版)

OBJECTIVE@#To determine the apoptosis-inducing effect of ultraviolet light (UV) on human lens epithelial cell (HLEC) and to explore the involvement of changes in ALDH1 folowing UV radiation.@*METHODS@#HLEC was exposed to the same UV light source and was subsequently divided into 6 groups according to UV radiation time of 0 (control group), 5, 10, 15, and 30 min. Apoptosis was detected by AO/EB staining. Changes of ALDH1 in HLEC were detected by immunohistochemical staining and Western blot.@*RESULTS@#The intensity of immunohistochemical staining and the rate of positive cells decreased with increase of UV time (P<0.05). The rate of positive ALDH1 cells was negatively correlated with the rate of apoptosis (r= -0.92, P<0.05). Western blot showed the integrated absorbance values significantly decreased with the increase of UV time (P<0.05).@*CONCLUSION@#ALDH1 in HLEC decreases with an increase of UV exposure, which may be related to UV induced apoptosis of HLEC.

Culture and identification of breast cancer stem cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To isolate breast cancer stem cells from breast cancer patients and identify their biological characteristics.</p><p><b>METHODS</b>Mammospheric cells were purified and enriched from the tumor tissues of breast cancer patients using mammosphere culture. Their expressions of CD44 and CD24 were analyzed by flow cytometry, and ALDH1, ESA and Oct4 expressions were determined by Western Blotting. The primary mammospheric and adherent cells, at the density of 2×10(4), 2×10(5) or 2×10(6), were inoculated into NOD/SCID mice to observe their tumorigenic and metastatic activities.</p><p><b>RESULTS</b>With mammosphere culture method, 62.36% of the mammospheric cells showed CD44(+)/CD24(-/low) phenotype. The expressions of ALDH1, ESA and Oct4 in the mammospheric cells were significantly higher than those in the adherent culture-derived breast cancer cells (P<0.05). Primary mammospheric cells were at least 100-fold more tumorigenic than the adherent cells; the mammospheric cells were associated with liver or lung metastases, but the adherent cells were not.</p><p><b>CONCLUSION</b>Mammosphere culture can be employed to obtain breast cancer stem cells from the tumor tissues of breast cancer patients.</p>

Aldehyde dehydrogenase 1 can be used as a new marker of cancer stem cells in laryngeal cancer cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To detect the expression of aldehyde dehydrogenase 1 in human laryngeal cancer cells in vitro, and to explore whether it can be used as a marker of stem cells in human laryngeal cancer.</p><p><b>METHODS</b>Fluorescence staining and flow cytometry were used to detect the expression of ALDH1 in a human laryngeal cancer Hep-2 cell line, and fluorescence activated cells sorting was used to separate ALDH1(br) cells. ALDH1 tumor cells were cultured and their ability of proliferation and differentiation was observed in vitro.</p><p><b>RESULTS</b>The expression of ALDH1 in Hep-2 cells was different. The number of cells highly expressing ALDH1 was 2.9% ± 0.6%. Compared with ALDH1(low) cells and unsorted cells, ALDH1(br) cells exhibited increased proliferation ability. In serum-containing RPM I1640 culture medium, the proportion of ALDH1(br) cells was decreasing as days passed. The percentage of ALDH1(br) cells decreased from 94.2% ± 3.8% to the level before sorting. The ALDH1(br) cells demonstrated enhanced tumorigenic ability in nude mice.</p><p><b>CONCLUSIONS</b>In the laryngeal cancer Hep-2 cell line, the highly ALDH1-expressing cells show a strong ability of differentiation, proliferation and tumorigenesis. It indicates that ALDH1 can be used as a new marker of stem cells of laryngeal cancer cells.</p>

Proteomics of the colonic mucosa in sub-healthy people with shapeless stool / 中南大学学报(医学版)

OBJECTIVE@#To establish the 2-dimensional electrophoresis (2-DE) map in colonic mucosa in sub-healthy people with shapeless stool and healthy people, to identify the differential proteins by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), and to provide theoretical basis for the pathogenesis of intestinal mucosa in sub-healthy people with shapeless stool.@*METHODS@#Two-DE was used to separate the total proteins from the intestinal mucosa in sub-healthy people (the sub-health group) with the shapeless stool and healthy volunteers (the control group). ImageMaster 2D Elite soft was applied to analyze the 2-DE images, and the differentially expressed protein spots between the 2 groups were identified by MALDI-TOF-MS, protein bank and information technique.@*RESULTS@#We analyzed the average maps and obtained 517 protein spots in the sub-healthy group and 535 protein spots in the control group. Between the sub-healthy group and the control group, the mean of 366 protein spots was matched, and the matching rate was 70.79%. Ten differential protein spots were screened by MALDI-TOF-MS, and 8 were identified. Five out of the 8 spots were significantly decreased, while 3 out of the 8 were significantly increased.@*CONCLUSION@#The proteomic expression in colonic mucosa of people with shapeless stool is significantly different from that of healthy people. Eight differential proteins such as aldehyde dehydrogenase 1A1 isoform 1, 3-hydroxy-3-methylglutaryl-coenzyme A synthase 2 (mitochondrial), γ-actin, annexin A5 possibly involve in the pathogenesis of sub-healthy people with shapeless stool.

[ immunohistochemical assessment of ALDH1 activity in breast cancer and it's correlation with pathologic features]

Aldehyde dehydrogenase 1 [ALDH1] is a marker of normal and malignant human mammary stem cells that has been reported to be associated with poor prognosis. Studies on the detection of ALDH1+cells can help the treatment of patients with breast cancer. The aim of this study was to determine the activity of ALDH1 in breast cancer and its relationship with the pathological features of the tumors. ALDH1 activity was studied by immunohistochemistry in 121 paraffin-embedded histological samples of breast cancer patients from Department of Pathology of Milad Hospital, Tehran, Iran during 2006-2007. The relationship of ALDH1 with the pathological features of the tumors [size, grade, lymph node metastasis and vascular invasion] was also investigated. Eighty-five percent of breast cancer samples expressed ALDH1 in their cytoplasm with a wide range of intensity [weak, moderate and strong], while 18 samples [14.9%] were completely negative. The majority of cases [97.1%] showed ALDH1 positivity in the stroma of tumors which varied from weak [2.9%] to strong [73.5%]. ALDH1 H-score [ALDH1% x intensity] of tumor cells varied from 0 to 240 [mean=80]. ALDH1 H-score was 80 in 59 [48.8%] samples. There was no statistically significant relationship between ALDH1 H-score and age [P=0.358], tumor size [P=0.375], tumor grade [P=0.207], lymph node metastasis [P=0.125] or vascular invasion [P=0.190]. ALDH1 activity was demonstrated in 85.1% of breast cancer samples although its level of expression was not correlated with the pathologic features of breast tumors

OCT4 Expression Enhances Features of Cancer Stem Cells in a Mouse Model of Breast Cancer / 한국실험동물학회지

The cancer stem cell (CSC) hypothesis proposes that CSCs are responsible for metastasis and disease recurrence. Therefore, targeting CSCs has the potential to significantly improve outcomes for cancer patients. The OCT4 transcription factor gene is a master gene that plays a key role in the self-renewal and pluripotency of stem cells. In this study, we introduced an OCT4 reporting vector into 4T1 mouse breast cancer cells and sorted OCT4 high and OCT4 low cell populations. We then determined whether OCT4 expression is associated with maintenance and expansion of CSCs. We found that OCT4high 4T1 cells have an increased ability to form tumorsphere and a high expression of stem cell markers such as Sca-1, CD133, CD34, and ALDH1, when compared with OCT4low 4T1 cells. In addition, OCT4high 4T1 cells have greater tumorigenic potential in vivo. These findings suggest that OCT4 expression may be a useful target for stem cell-specific cancer therapy.

Inhibitor of DNA-binding 4 contributes to the maintenance and expansion of cancer stem cells in 4T1 mouse mammary cancer cell line / 한국실험동물학회지

The cancer stem cell (CSC) hypothesis proposes that CSCs are the root of cancer. CSC-targeted therapies may prevent cancer relapse and provide more effective treatment. The expression of aldehyde dehydrogenase 1, as assessed by the Aldefluor assay, has been recognized as a marker of CSCs in breast cancer. Inhibitors of DNA-binding proteins (IDs) have an important role in stem cell differentiation. In this study, we examined IDs necessary for the regulation of stem properties in Aldefluorpos 4T1 cells. When the expression profile of IDs in Aldefluorneg and Aldefluorpos 4T1 cells was compared, qRT-PCR analysis showed that ID4 expression was highly upregulated in Aldefluorpos 4T1 cells. In addition, knockdown of ID4 expression suppressed the properties of CSCs, including their sphere-forming ability and side population phenotype. The findings suggest that ID4 may be a therapeutic target for the treatment of advanced breast cancer.

Effects of 5-Aza-2'-deoxycitydine and trichostatin A on expression and apoptosis of ALDH1a2 gene in human bladder cancer cell lines / 中华外科杂志

<p><b>OBJECTIVE</b>To study the effect on promoter de-methylation, expression of ALDH1a2 gene and cell apoptosis by treated with 5-Aza-dC and TSA in five human bladder cancer cell lines.</p><p><b>METHODS</b>Human bladder cancer cell lines RT-4, 253J, 5637, BIU-87 and T24 were cultured and treated with 5-Aza-dC and(or) TSA. The expression of the ALDH1a2 gene was detected by RT-PCR and Western blot. The methylation status of gene promoter was determined by MSP, and the cell cycle profile was established by flow cytometry.</p><p><b>RESULTS</b>ALDH1a2 was silenced in five human bladder cancer cell lines. Re-expression of ALDH1a2 was detected after treated with 5-Aza-dC alone or TSA in combination. ALDH1a2 transcript was marked in each cell lines combined with 5-Aza-dC and TSA treatment which showed a synergistic effect on expression of ALDH1a2 transcript. Early apoptotic was the main mode of apoptosis and death of human bladder cancer cell lines induced by 5-Aza-dC and TSA. The percentage of early apoptotic cells was 1.4% in control group and 2.8% in TSA group, however, 20.2% in 5-Aza-dC group and 33.8% in 5-Aza-dC + TSA group, respectively. The groups of TSA, 5-Aza-dC and 5-Aza-dC + TSA were significantly different from control group (P < 0.05).</p><p><b>CONCLUSIONS</b>Aberrant methylation of ALDH1a2 gene is the main cause for gene transcriptional inactivation. Re-expression of ALDH1a2 gene and cell apoptosis are detected after either treatment with 5-Aza-dC alone or in combination with TSA.</p>

Technology update for the sorting and identification of breast cancer stem cells / 癌症

Breast cancer stem cells are a group of undifferentiated cells with self-renewal and multidifferentiation potential. Chemotherapeutic and radiotherapeutic resistance, hypoxic resistance, high tumorigenicity, high cell invasion, and metastatic abilities are characteristics of these cells, which are responsible for breast cancer recurrence. Therefore, the correct sorting and identification of breast cancer stem cells is a primary step for research in this field. This article briefly describes the recent progress on sorting and identification technologies for breast cancer stem cells. Sorting technologies include the side population technique, technologies that depend on cell surface markers, ALDEFLUOR assays, and in situ detection. Identification technologies include mammosphere cultures, limited dilution in vitro, and in-vivo animal models. This review provides an important reference for breast cancer stem cell research, which will explore new methods for the treatment of patients with breast cancer.

Advancement of studies on ALDH1 as a universal marker of stem cells / 生物医学工程学杂志

Aldehyde dehydrogenase 1 (ALDH1, ALDH1A1 or RALDH1), an enzyme responsible for the oxidation of intracellular aldehydes, was shown to have a function in the early differentiation of stem cells. Its activity shows promising potential as a universal marker for the identification and isolation of normal stem cells and cancer stem cells from multiple sources in a variety of tissue types. Herein, we review the available data reporting the utilization of ALDH1 activity as a means to identify and isolate normal stem cells and cancer stem cells (CSCs), and the potential diagnostic and therapeutic implications, with a special focus on the mammary gland and breast cancer. The research opportunity in this area of interest is emphasized.