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ALDH1A1

aldehyde dehydrogenase 1 family, member A1;ALDH1A1;aldehyde dehydrogenase 1 family, member A1

ALDH class 1|ALHDII|RALDH 1|acetaldehyde dehydrogenase 1|aldehyde dehydrogenase 1, soluble|aldehyde dehydrogenase, liver cytosolic|epididymis luminal protein 12|epididymis luminal protein 9|epididymis secretory sperm binding protein Li 53e|retinal dehydro

9q21.13

protein-coding

Breast cancer stem cells are thought to be associated with metastasis and poor prognosis, but their clinical importance remains poorly understood. The aim of this study was to investigate whether certain phenotypes of breast cancer stem cells were clinically important factors regarding metastasis. Patients with primary breast cancer (n=121) were included in this study. Breast cancer stem cells were identified by immunohistochemical staining of CD44, CD24, and aldehyde dehydrogenase 1 (ALDH1) in tumor tissues from primary and recurrent or metastatic lesions. CD44+/CD24- cells and ALDH1+ cells were considered breast cancer stem cells. Sixty-five patients had metastatic or recurrent tumors. ALDH1+ tumors were significantly associated with a high rate of metastasis or recurrence (63.1%; P=0.026). Although there was no significant association between the proportion of CD44+/CD24- tumor cells and metastasis rates, a high proportion of CD44+/CD24- tumor cells was a risk factor for metastasis or recurrence (P=0.035). Changes in the proportion of CD44+/CD24- or ALDH1+ tumor cells between primary lesions and recurrent lesions were studied in 27 patients. The proportion of ALDH1+ tumor cells increased significantly (P=0.019) after recurrence, but the proportion of CD44+/CD24- tumor cells did not. Our findings suggest that ALDH1+ and CD44+/CD24- breast cancer stem cells play significant roles in metastasis. The rate of ALDH1+ cells appears to be a better predictive marker of breast cancer metastasis than the CD44+/CD24- phenotype.

Invasion and metastasis are the major cause of deaths in patients with esophageal cancer. In this study, we isolated cancer stem-like cells from an esophageal squamous cell carcinoma cell line EC109 based on aldehyde dehydrogenase 1A1 (ALDH1A1), and found that ALDH1A1(high) cells possessed the capacities of self-renewal, differentiation and tumor initiation, indications of stem cell properties. To support their stemness, ALDH1A1(high) cells exhibited increased potential of invasion and metastasis as compared with ALDH1A1(low) cells. ALDH1A1(high) esophageal squamous cell carcinoma cells expressed increased levels of mRNA for vimentin, matrix metalloproteinase 2, 7 and 9 (MMP2, MMP7 and MMP9), but decreased the level of E-cadherin mRNA, suggesting that epithelial-mesenchymal transition and secretary MMPs may be attributed to the high invasive and metastatic capabilities of ALDH1A1(high) cells. Furthermore, we examined esophageal squamous cell carcinoma specimens from 165 patients and found that ALDH1A1(high) cells were associated with esophageal squamous dysplasia and the grades, differentiation and invasion depth, lymph node metastasis and UICC stage of esophageal squamous cell carcinoma, as well as poor prognosis of patients. Our results provide the strong evidence that ALDH1A1(high) cancer stem-like cells contribute to the invasion, metastasis and poor outcome of human esophageal squamous cell carcinoma.

One of the major factors involved in the prognosis of oral squamous cell carcinoma (OSCC) patients is metastasis. Recent progress in cancer stem-like cell/cancer-initiating cell (CSC/CIC) research indicates that CSCs are related to metastasis. Aldehyde dehydrogenase 1 - (ALDH1) and SRY-related HMG-box gene 2 (SOX2) have recently been shown to be putative CSC markers for several human malignancies. The aim of this study was to determine the association of ALDH1 and SOX2 expression in oral squamous cell carcinoma (OSCC) with lymph node metastasis. Immunohistochemical staining of ALDH1, SOX2 and Ki67 was performed in 80 OSCC tissues. High expression rates of ALDH1 (2%-40%) were found to be related to lymph node metastasis (P = 0.0017). Interestingly, we found that SOX2 staining could be classified into two patterns: (i) peripheral staining pattern; and (ii) diffuse staining pattern. The diffuse staining pattern showed a significant correlation with lymph node metastasis (P < 0.001). No correlation was found between Ki67 staining and lymph node metastasis (P = 0.4724). The ALDH1 positive staining rates in metastatic lymph nodes were higher than that in corresponding primary OSCC tissues. These results indicate that high expression rates of ALDH1 and SOX2 diffuse staining patterns might be novel prediction markers for OSCC lymph node metastasis.

metastatic progression of advanced prostate cancer is a major clinical problem. Identifying the cell(s) of origin in prostate cancer and its distant metastases may permit the development of more effective treatment and preventive therapies. In this study, aldehyde dehydrogenase (ALDH) activity was used as a basis to isolate and compare subpopulations of primary human prostate cancer cells and cell lines. ALDH-high prostate cancer cells displayed strongly elevated clonogenicity and migratory behavior in vitro. More strikingly, ALDH-high cells readily formed distant metastases with strongly enhanced tumor progression at both orthotopic and metastatic sites in preclinical models. Several ALDH isoforms were expressed in human prostate cancer cells and clinical specimens of primary prostate tumors with matched bone metastases. Our findings suggest that ALDH-based viable cell sorting can be used to identify and characterize tumor-initiating and, more importantly perhaps, metastasis-initiating cells in human prostate cancer.

BACKGROUND: cancer stem cells (CSCs) have been shown to be a small stem cell-like cell population which appears to drive tumorigenesis, tumor recurrence and metastasis. Thus, identification and characterization of CSCs may be critical to defining effective anticancer therapies. In prostate cancer (PCa), the CD44(+) cell population appears to have stem cell-like properties including being tumorigenic. The enzyme aldehyde dehydrogenase (ALDH) has been found to identify hematopoietic stem cells and our aim was to determine the utility of ALDH activity and CD44 in identifying PCa stem cell-like cells in PCa cell lines. MATERIALS AND METHODS: LNCaP cells and PC-3 cells were sorted based on their expression of CD44 and ALDH activity. The cell populations were investigated using colony-forming assays, invasion assays, sphere formation experiments in a non-adherent environment and 3-D Matrigel matrix culture to observe the in vitro stem-cell like properties. Different sorted cell populations were injected subcutaneously into NOD/SCID mice to determine the corresponding tumorigenic capacities. RESULTS: ALDH(hi) CD44(+) cells exhibit a higher proliferative, clonogenic and metastatic capacity in vitro and demonstrate higher tumorigenicity capacity in vivo than did ALDH(lo) CD44(-) cells. The tumors recapitulated the population of the original cell line. However, ALDHlo CD44(-) cells were able to develop tumors, albeit with longer latency periods. CONCLUSION: ALDH activity and CD44 do not appear to identify PCa stem cells; however, they do indicate increased tumorigenic and metastatic potential, indicating their potential importance for further exploration.

BACKGROUND: ALDH1 has been shown to be a cancer stem cell marker, and its expression correlates with prognosis in a number of malignancies. We aimed to evaluate the expression of ALDH1 in a cohort of primary and metastatic RCC specimens, and to correlate expression with pathological outcomes such as tumor stage and grade, and clinical outcomes such as progression free survival. METHODS: Three tissue microarrays were constructed from 244 RCC specimens, taken from 1985 to 2006. Samples were stained using an ALDH1 monoclonal antibody and expression was quantified by degree of staining. Membrane and cytoplasm staining were considered separately. A retrospective chart review enabled correlation with clinical outcomes. RESULTS: ALDH1 expression did not vary significantly based on tumor stage (P = 0.6274) or grade (P = 0.1666). ALDH1 showed significantly more membranous expression in clear cell RCC versus other subtypes (P < 0.0001), as well as in the primary setting compared to metastases (P = 0.0216). In terms of progression free survival, no significant differences were seen based on ALDH1 expression levels. In a subanalysis of clear cell tumors, ALDH1 membranous expression was decreased in tumors of higher stage (P = 0.0233). CONCLUSIONS: ALDH1 may be useful in characterizing RCC tumors as clear cell subtype. However, unlike in other malignancies, ALDH1 may not be useful in prognosticating renal cancers. The clinical significance of decreased ALDH1 expression in the high stage and metastatic setting remains to be determined in further investigations.