Age determines the prognostic role of the cancer stem cell marker aldehyde dehydrogenase-1 in breast cancer

Molecular Interactions of Selective Agonists and Antagonists with the Retinoic Acid Receptor γ

All-trans retinoic acid (ATRA), the major active metabolite of all-trans retinol (vitamin A), is a key hormonal signaling molecule. In the adult organism, ATRA has a widespread influence on processes that are crucial to the growth and differentiation of cells and, in turn, the acquisition of mature cell functions. Therefore, there is considerable potential in the use of retinoids to treat diseases. ATRA binds to the retinoic acid receptors (RAR) which, as activated by ATRA, selectively regulate gene expression. There are three main RAR isoforms, RARα, RARβ, and RARγ. They each have a distinct role, for example, RARα and RARγ regulate myeloid progenitor cell differentiation and hematopoietic stem cell maintenance, respectively. Hence, targeting an isoform is crucial to developing retinoid-based therapeutics. In principle, this is exemplified when ATRA is used to treat acute promyelocytic leukemia (PML) and target RARα within PML-RARα oncogenic fusion protein. ATRA with arsenic trioxide has provided a cure for the once highly fatal leukemia. Recent in vitro and in vivo studies of RARγ have revealed the potential use of agonists and antagonists to treat diseases as diverse as cancer, heterotopic ossification, psoriasis, and acne. During the final drug development there may be a need to design newer compounds with added modifications to improve solubility, pharmacokinetics, or potency. At the same time, it is important to retain isotype specificity and activity. Examination of the molecular interactions between RARγ agonists and the ligand binding domain of RARγ has revealed aspects to ligand binding that are crucial to RARγ selectivity and compound activity and key to designing newer compounds.

ALDH1A1 drives prostate cancer metastases and radioresistance by interplay with AR- and RAR-dependent transcription

Rationale: Current therapies for metastatic osseous disease frequently fail to provide a durable treatment response. To date, there are only limited therapeutic options for metastatic prostate cancer, the mechanisms that drive the survival of metastasis-initiating cells are poorly characterized, and reliable prognostic markers are missing. A high aldehyde dehydrogenase (ALDH) activity has been long considered a marker of cancer stem cells (CSC). Our study characterized a differential role of ALDH1A1 and ALDH1A3 genes as regulators of prostate cancer progression and metastatic growth. Methods: By genetic silencing of ALDH1A1 and ALDH1A3 in vitro, in xenografted zebrafish and murine models, and by comparative immunohistochemical analyses of benign, primary tumor, and metastatic specimens from patients with prostate cancer, we demonstrated that ALDH1A1 and ALDH1A3 maintain the CSC phenotype and radioresistance and regulate bone metastasis-initiating cells. We have validated ALDH1A1 and ALDH1A3 as potential biomarkers of clinical outcomes in the independent cohorts of patients with PCa. Furthermore, by RNAseq, chromatin immunoprecipitation (ChIP), and biostatistics analyses, we suggested the molecular mechanisms explaining the role of ALDH1A1 in PCa progression. Results: We found that aldehyde dehydrogenase protein ALDH1A1 positively regulates tumor cell survival in circulation, extravasation, and metastatic dissemination, whereas ALDH1A3 plays the opposite role. ALDH1A1 and ALDH1A3 are differentially expressed in metastatic tumors of patients with prostate cancer, and their expression levels oppositely correlate with clinical outcomes. Prostate cancer progression is associated with the increasing interplay of ALDH1A1 with androgen receptor (AR) and retinoid receptor (RAR) transcriptional programs. Polo-like kinase 3 (PLK3) was identified as a transcriptional target oppositely regulated by ALDH1A1 and ALDH1A3 genes in RAR and AR-dependent manner. PLK3 contributes to the control of prostate cancer cell proliferation, migration, DNA repair, and radioresistance. ALDH1A1 gain in prostate cancer bone metastases is associated with high PLK3 expression. Conclusion: This report provides the first evidence that ALDH1A1 and PLK3 could serve as biomarkers to predict metastatic dissemination and radiotherapy resistance in patients with prostate cancer and could be potential therapeutic targets to eliminate metastasis-initiating and radioresistant tumor cell populations.

Balanitoside as a Natural Adjuvant to Gemcitabine in Lung Cancer Experimental Model

Gemcitabine is a chemotherapeutic drug used to treat cancer; however, it has severe side effects. Therefore, we evaluated the anticancer potency of balanitoside, a folk medicine isolated from the edible fruits of Balanites aegyptiaca, using a mouse model of lung cancer induced by Urethane/butylated hydroxytoluene, either alone or in combination with gemcitabine. The results indicated that balanitoside, when administered alone or in combination with gemcitabine, exhibited antitumor activity against lung cancer by reducing tumor incidence, multiplicity, and average tumor size. It also decreased the proliferation of tumor cells, induced apoptosis, triggered cell cycle arrest at the G0/G1 phase, and caused a marked reduction in cancer stem cell markers, aldehyde dehydrogenase (ALDH-1) levels, and the CD133 (+ve) cell population. Balanitoside also modulated the levels of oxidative stress markers in lung tissues. The results indicate that balanitoside enhances the antitumor activity of gemcitabine and may represent a natural adjuvant medication for lung cancer.

Prominent Prognostic Factors in Aggressive Breast Cancer: A Review

Context: Breast cancer (BC) is the most common cancer in women worldwide. Hereditary susceptibility created by mutations in autosomal dominant genes is responsible for 5 to 10% of all BC cases in women. Recent studies have identified genes associated with increased risk for aggressive BC, providing the basis for better risk management. Evidence Acquisition: The latest information in National Center for Biotechnology Information (NCBI), Google Scholar, ScienceDirect, and Scopus were the main databases for finding articles. A combination of keywords of ‘metastasis’, ‘invasion’, ‘aggressive breast cancer’, ‘prognostic factor’, ‘mutation’, and ‘cancer treatment’ was searched in the databases to identify related articles. Titles and abstracts of the articles were studied to choose the right articles. Results: Mutations in breast cancer type 1 susceptibility protein (BRCA1) and breast cancer type 2 susceptibility protein (BRCA2) genes are two central players related to the high risk of BC. Mutation in tumor protein p53 (TP53) is another important mutation that leads to triple-negative BC. Although the majority of BC types are not associated with high-throughput mutant genes such as BRCA1, BRCA2, and TP53, they are associated with low-throughput genes, including DNA repair protein Rad50 (RAD50), Nijmegen breakage syndrome gene (NBS1), checkpoint kinase 2 (CHEK2), BRCA1-interacting protein 1 (BRIP1), E-cadherin gene (CDH1) and PALB2, UCHL1, aldehydedehydrogenase1A3 (ALDH1A3), androgen receptor (AR), 5-bisphosphate 3-kinase (PIK3CA), phosphatidylinositol-4, and luminal gene expression that are generally mutated in the global population. High tumor mutational burden (TMB) was associated with improved progression-free survival. Conclusions: The lymph node status, early tumor size, ER, PR, human epidermal growth factor receptor-2 (HER2), and Ki-67 are conventional prognostic factors for BC. However, these factors cannot exactly predict the aggressive behavior of BC. Hence, in this review, we discussed new prognostic factors of aggressive BCs that are useful for the treatment of patients with BC.

Biology of primary breast cancer in older women beyond routine biomarkers

Purpose

There are numerous biomarkers which may have potential predictive and prognostic significance in breast cancer. This is extremely important in older adults, who may opt for less aggressive therapy. This work outlines the literature on biological assessment outside of standard biomarkers (defined as ER, PgR, HER2, Ki67) in women ≥ 65 years with primary operable invasive breast cancer, to determine which additional biomarkers are relevant to outcome in older women.

Methods

Medline and Embase databases were searched. Studies were eligible if included ≥ 50 patients aged ≥ 65 years; stratified results by age; measured a biomarker outside of standard assay and reported patient data.

Results

A total of 12 studies were appraised involving 5000 patients, measuring 28 biomarkers. The studies were extremely varied in methodology and outcome but three themes emerged: 1. Differences in biomarker expression between younger and older women, indicating that breast cancer in older women is generally less aggressive compared to younger women; 2. Relationship of biomarker expression with survival, suggesting biomarkers which may exclusively predict response to primary treatment in older women; 3. Association of biomarker with chemotherapy, suggesting that older patients should not be declined chemotherapy based on age alone.

Conclusion

There is evidence to support further investigation of B-cell lymphoma (BCL2), liver kinase (LK)B1, epidermal growth factor receptor (EGFR), cytoplasmic cyclin-E, mucin (MUC)1 and cytokeratins (CKs) as potential predictive or prognostic markers in older women with breast cancer undergoing surgery. Studies exploring these biomarkers in larger cohorts and in women undergoing non-operative therapies are required.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12282-021-01266-5.

Bayesian Generalized Linear Mixed Modeling of Breast Cancer

BACKGROUND

Breast cancer is one of the most common cancers among women. Breast cancer treatment strategies in Nigeria need urgent strengthening to reduce mortality rate because of the disease. This study aimed to determine the relationship between the ages at diagnosis and established the prognostic factors of modality of treatment given to breast cancer patient in Nigeria.

METHODS

The data was collected for 247 women between years 2011-2015 who had breast cancer in two different hospitals in Ekiti State, Nigeria. Model estimation is based on Bayesian approach via Markov Chain Monte Carlo. A multilevel model based on generalized linear mixed model is used to estimate the random effect.

RESULTS

The mean age of the patients (at the time of diagnosis) was 42.2 yr with 52% of the women aged between 35-49 yr. The results of the two approaches are almost similar but preference is given to Bayesian because the approach is more robust than the frequentist. Significant factors of treatment modality are age, educational level and breast cancer type.

CONCLUSION

Differences in socio-demographic factors such as educational level and age at diagnosis significantly influence the modality of breast cancer treatment in western Nigeria. The study suggests the use of Bayesian multilevel approach in analyzing breast cancer data for the practicality, flexibility and strength of the method.

Breast cancer stem cells expressing different stem cell markers exhibit distinct biological characteristics

Identification and isolation of breast cancer stem cells (CSCs) based on CD44/CD24 expression and/or enzymatic activity of aldehyde dehydrogenase 1 (ALDH1). However, the differences among the CD44+/CD24‑/low cells, ALDH1+ cells and the overlap between the sub‑populations have not been frequently investigated. Thus, it is imperative to improve the understanding of breast CSC with different stem markers. CD44+/CD24‑/low, ALDH1+ and ALDH1+CD44+/CD24‑/low cell populations were isolated from fresh breast cancer tissues and analyzed by flow cytometry and immunofluorescence. Mammosphere formation, cell proliferation assay and Transwell experiments, were used to analyze self‑renewal, proliferation and invasion, respectively, for each sub‑population. Finally, in vivo experimentation in mice was performed to evaluate the tumorigenic abilities of the sub‑populations. The sub‑populations of CD44+/CD24‑/low, ALDH1+ and ALDH1+CD44+/CD24‑/low in human breast cancer cells, represented the 7.2, 4.6 and 1.5% of the total tumor cell population, respectively. ALDH1+CD44+/CD24‑/low cells had the strongest ability of self‑renewal, invasion, proliferation and tumorigenicity compared with the other sub‑populations (P<0.05). In conclusion, different phenotypes of CD44+/CD24‑/low, ALDH1+ and ALDH1+CD44+/CD24‑/low were isolated and demonstrated that breast CSCs are heterogeneous, and they exhibit distinct biological characteristics. As ALDH1+CD44+/CD24‑/low cells demonstrated the strongest stem‑like properties, it may be a useful specific stem cell marker. The utilization of more reliable biomarkers to distinguish the breast CSC pool will be important for the development of specific target therapies for breast cancer.

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

Background

The 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.

Methods

In 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.

Results

The 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).

Conclusions

Among 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.

The prognostic roles of ALDH1 isoenzymes in gastric cancer

Increased aldehyde dehydrogenase 1 (ALDH1) activity has been determined to be present in the stem cells of several kinds of cancers including gastric cancer (GC). Nevertheless, which ones of ALDH1's isoenzymes are leading to ALDH1 activity remains elusive. In this study, we examined the prognostic value and hazard ratio (HR) of individual ALDH1 isoenzymes in patients with GC using "The Kaplan-Meier plotter" database. mRNA high expression level of ALDH1A1 was not found to be significantly correlated with the overall survival (OS) of all patients with GC followed for 20 years, HR =0.86 (95% confidence interval [CI]: 0.7-1.05), P=0.13. mRNA high expression level of ALDH1A2 was also not significantly correlated with OS for all patients with GC, HR =1.13 (95% CI: 0.91-1.41), P=0.25. mRNA high expression level of ALDH1A3 was found to be significantly correlated with worsened OS in either intestinal-type patients, HR =2.24 (95% CI: 1.44-3.49), P=0.00026, or diffuse-type patients, HR =1.91 (95% CI: 1.02-3.59), P=0.04. Interestingly, mRNA high expression level of ALDH1B1 was found to be significantly correlated with better OS for all patients with GC, HR =0.66 (95% CI: 0.53-0.81), P=7.8e-05, and mRNA high expression level of ALDH1L1 was found to be significantly correlated with worsened OS for all patients with GC, HR =1.23 (95% CI: 1-1.51), P=0.048. Furthermore, our results also indicate that ALDH1A3 and ALDH1L1 are potential major contributors to the ALDH1 activity in GC, since mRNA high expression levels of ALDH1A3 and ALDH1L1 were found to be significantly correlated with worsened OS for all patients with GC. Based on our study, ALDH1A3 and ALDH1L1 are potential prognostic markers and therapeutic targets for patients with GC.

Prognostic values of aldehyde dehydrogenase 1 isoenzymes in ovarian cancer

Aldehyde dehydrogenase 1 (ALDH1) activity has been used as a functional stem cell marker to isolate cancer stem cells in different cancer types, including ovarian cancer. However, which ALDH1’s isoenzymes are contributing to ALDH1 activity in ovarian cancer remains elusive. In addition, the prognostic value of an individual ALDH1 isoenzyme in ovarian cancer is not clear. Thus, we accessed the prognostic value of ALDH1 isoenzymes in ovarian cancer patients through the “Kaplan–Meier plotter” online database, which can be used to determine the effect of the genes on ovarian cancer prognosis. We found that high mRNA expression of five ALDH1 isoenzymes, such as ALDH1A1, ALDH1A2, ALDH1A3, ALDH1B1, and ALDH1L1, was not correlated with overall survival (OS) for all 1,306 ovarian cancer patients. In addition, all five of the ALDH1 isoenzymes’ high mRNA expression was found to be uncorrelated with OS in serous cancer or endometrioid cancer patients. However, ALDH1A3’s high mRNA expression is associated with worse OS in grade II ovarian cancer patients, hazard ratio (HR) 1.53 (1.14–2.07), P=0.005. ALDH1A2’s high mRNA expression is significantly associated with worse OS in TP53 wild-type ovarian cancer patients, HR 2.86 (1.56–5.08), P=0.00036. In addition, ALDH1A3’s high mRNA expression is significantly associated with better OS in TP53 wild-type ovarian cancer patients, HR 0.56 (0.32–1.00), P=0.04. Our results indicate that although ALDH1 isoenzyme mRNA might not be a prognostic marker for overall ovarian cancer patients, some isoenzymes, such as ALDH1A2 and ALDH1A3, might be a good prognostic marker for some types of ovarian cancer patients.

Effect of ALDH1 on prognosis and chemoresistance by breast cancer subtype

Aldehyde dehydrogenase 1 (ALDH1) has been identified as a breast cancer stem cell marker, but its value as a predictor of prognosis and chemoresistance is controversial. This study investigated the effect of ALDH1 on prognosis and chemoresponse by breast cancer subtype. We immunohistochemically analyzed 653 invasive breast cancer specimens and evaluated correlations among clinicopathological factors, survival status, response to neoadjuvant chemotherapy, and ALDH1 expression. Of 653 specimens, 139 (21.3 %) expressed ALDH1 in tumor cells. ALDH1 expression was correlated significantly with larger tumor size, node metastasis, higher nuclear grade, and with HER2(+) and progesterone/estrogen receptor (HR)(-) subtypes. ALDH1 expression was significantly observed in HER2 type and triple-negative breast cancer (TNBC). Patients with ALDH1(+) cancers had significantly shorter disease-free survival (P < 0001) and overall survival (P = 0.044). ALDH1 expression significantly affected prognosis of luminal types, but not TNBC and HER2-enriched types. For the 234 patients treated with neoadjuvant chemotherapy, pathological complete response (pCR) rate was significantly lower in ALDH1(+) cases (13.5 vs. 30.3 %, P = 0.003). pCR and ALDH1 expression were significantly correlated in TNBC patients (P = 0.003). ALDH1(+) breast cancers tended to be aggressive, with poor prognoses. Although ALDH1(+) TNBC showed higher chemoresistance, ALDH1 had significant impact on prognosis in the luminal type but not in TNBC.

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.

Distinct prognostic values and potential drug targets of ALDH1 isoenzymes in non-small-cell lung cancer

Increased aldehyde dehydrogenase 1 (ALDH1) activity has been found in the stem cell populations of leukemia and some solid tumors including non-small-cell lung cancer (NSCLC). However, which ALDH1’s isoenzymes are contributing to ALDH1 activity remains elusive. In addition, the prognostic value of individual ALDH1 isoenzyme is not clear. In the current study, we investigated the prognostic value of ALDH1 isoenzymes in NSCLC patients through the Kaplan–Meier plotter database, which contains updated gene expression data and survival information from a total of 1,926 NSCLC patients. High expression of ALDH1A1 mRNA was found to be correlated to a better overall survival (OS) in all NSCLC patients followed for 20 years (hazard ratio [HR] 0.88 [0.77–0.99], P=0.039). In addition, high expression of ALDH1A1 mRNA was also found to be correlated to better OS in adenocarcinoma (Ade) patients (HR 0.71 [0.57–0.9], P=0.0044) but not in squamous cell carcinoma (SCC) patients (HR 0.92 [0.72–1.16], P=0.48). High expression of ALDH1A2 and ALDH1B1 mRNA was found to be correlated to worser OS in all NSCLC patients, as well as in Ade, but not in SCC patients. High expression of both ALDH1A3 and ALDH1L1 mRNA was not found to be correlated to OS in all NSCLC patients. These results strongly support that ALDH1A1 mRNA in NSCLC is associated with better prognosis. In addition, our current study also supports that ALDH1A2 and ALDH1B1 might be major contributors to the ALDH1 activity in NSCLC, since high expression of ALDH1A2 and ALDH1B1 mRNA was found to be significantly correlated to worser OS in all NSCLC patients. Based on our study, ALDH1A2 and ALDH1B1 might be excellent potential drug targets for NSCLC patients.

Clinicopathological significance of ALDH1A1 in lung, colorectal, and breast cancers: a meta-analysis

AIM

Aldehyde dehydrogenase 1 family member A1 (ALDH1A1) is a putative cancer stem cell marker. This meta-analysis evaluated ALDH1A1 expression's clinicopathological associations with lung cancer (LC), colorectal cancer (CRC) and breast cancer (BC).

MATERIALS & METHODS

Publications were retrieved from various databases and assessed for relevance and quality. Relationships between ALDH1A1 expression and clinicopathological characteristics were evaluated using Review Manager 5.2 software.

RESULTS

Thirty-eight studies were included (6057 patients). ALDH1A1 expression was significantly associated with the presence of LC; lymph node metastasis, clinical stage and differentiation in LC and BC; and molecular subtype in BC (p < 0.05). There were no significant association with BC tumor size and CRC.

CONCLUSION

ALDH1A1 may be a stem cell marker in LC and BC.

Stem cell biomarker ALDH1A1 in breast cancer shows an association with prognosis and clinicopathological variables that is highly cut-off dependent

AIMS

Aldehyde dehydrogenase family 1 member A1 (ALDH1A1) is a putative marker of breast cancer stem cells (CSCs) with prognostic implications when expressed in cancer or stroma. However, previous results are contradictory and we therefore aimed to further evaluate the impact of ALDH1A1 on distant disease-free survival (DDFS) and correlation with clinicopathological variables in breast cancer, specifically by evaluating different cut-offs.

METHODS

Two breast cancer cohorts (N=216 and N=210) were evaluated with immunohistochemistry for ALDH1A1 on tissue microarrays with three different cut-offs in cancer cells and in stromal cells. The association of ALDH1A1 with DDFS and other clinicopathological variables was assessed. As further validation, gene expression levels of ALDH1A1 and association with survival were analysed in one of the cohorts and a separate cohort.

RESULTS

ALDH1A1 expression in cancer cells was associated with either a better or a worse prognosis, depending on cut-off. Considering weakly stained cancer cells as positive, ALDH1A1+ was associated with a better prognosis in both cohorts. Considering only strongly stained cells as positive, ALDH1A1+ was associated with oestrogen receptor and progesterone receptor negativity in both cohorts and worse prognosis in one of the cohorts. Stromal ALDH1A1 staining was associated with improved DDFS in one cohort. Gene expression analysis showed that a high ALDH1A1 expression was associated with a better prognosis.

CONCLUSIONS

ALDH1A1 is associated with DDFS and clinicopathological variables, both in cancer cells and stroma, but is highly cut-off dependent. Only the strongly ALDH1A1-stained cells show a more aggressive phenotype typical for CSCs.

Aldehyde dehydrogenase 1 expression correlates with clinicopathologic features of patients with breast cancer: a meta-analysis

A number of studies have investigated the relationship between aldehyde dehydrogenase 1 (ALDH1) expression and the clinical pathological features of the patients with breast cancer. However, conclusions reported by different parties seem to be inconsistent. We have reviewed published studies and carried out this meta-analysis to provide credible results. We searched PubMed for articles published in English until September 12, 2014. Our main analyses were focused on the association between ALDH1 and the clinical pathological features, such as age, tumor size, nodal status, lymphovascular invasion, histological grade, and the expression of ER, PR, and HER2 by meta-analysis methods. If heterogeneity was observed, we used random effects model to calculate the overall odds ratios, otherwise fixed effects model was used. Twenty-one eligible studies were included in the present meta-analysis. From the pooled analyses, there was significant association between ALDH1 expression and histological grade (low vs. intermediate: pooled OR = 1.51, 95% CI: 1.09-2.10, P = 0.01; intermediate vs. high: pooled OR = 1.86, 95% CI: 1.12-3.07, P = 0.02), ER expression (pooled OR = 0.41, 95% CI: 0.29-0.58, P < 0.00001), and PR expression (pooled OR = 0.56, 95% CI: 0.40-0.77, P = 0.0004). No clear correlation was found between ALDH1 expression and age, tumor size, lymph node (LN) metastasis, lynphovascular invasion, and HER2 expression (P > 0.05). Despite the inconsistency in the published reports, this meta-analysis provides credible evidence to support the association between ALDH1 and breast cancer. However, it is necessary to conduct large sample studies using standardized and well-matched controls.

Proliferation rate and breast cancer subtype, but not ALDH1 expression, predict pathological response to neoadjuvant chemotherapy in locally advanced breast cancer

For locally advanced breast cancer, pathological complete response (pCR) following neoadjuvant chemotherapy (NACT) is associated with good disease-free survival. In several studies, response to chemotherapy according to various parameters has shown strong inter-individual variability. We investigated whether different prognostic factors, including ALDH1 expression, might predict response to NACT in female patients with locally advanced breast carcinoma. ER, PR, Her2/neu, Ki-67 and ALDH1 immunohistochemistry were performed on the initial biopsy and subsequent resection specimens. Residual tumour burden was calculated in post NACT resection specimens using residual cancer burden (RCB) protocol. Of our cohort of 66 patients, 24 (36 %) achieved pCR. Triple negative phenotype and high Ki-67 proliferative index (>40 %) were significantly associated with good response to NACT. ALDH1 expression in tumour epithelial (20 %) or stromal (44 %) cells did not correlate with tumour grade, molecular subtype, proliferative index or NACT response. However, epithelial and stromal ALDH1 expression was significantly increased in residual tumour after NACT. In conclusion, triple negative phenotype and high proliferative index, but not ALDH1 expression, are predictive of good pathological response to NACT. Increased ALDH1 expression following NACT might be associated with a higher probability of recurrent disease.

Age-dependent clinical prognostic value of histone modifications in colorectal cancer

Aging is one of the prime risk factors for the development of cancer. Expression patterns of epigenetic regulators, including histone modification levels, are altered during aging of normal cells, a phenomenon referred to as epigenetic drift. Furthermore, it is known that epigenetic mechanisms are involved in the development of cancer. We hypothesized that expression of histone modifications, acetylation of histone 3 lysine 9 (H3K9Ac) and trimethylation of histone 3 lysine 27 (H3K27me3), with reported normal age-related expression patterns might show an age-dependent prognostic value in colorectal cancer (CRC). To quantify expression, we performed immunohistochemical staining of these histone modifications on a tissue microarray containing colorectal tissues of the 254 patients with TNM stage I-III CRC. Stratification of patients according to survival status revealed age-related tumor expression patterns of both H3K9Ac and H3K27me3. Decreased expression with advancing age was observed in patients who were alive after follow-up (no-event group), whereas increased expression with advancing age was observed in patients who presented with a recurrence or death in follow-up (event group). These opposite expression patterns translated into an age-dependent prognostic value in CRC for the individual histone modifications and their combination. The prognostic value reverses with advancing age, high nuclear expression associated with good clinical outcome in young adults, and, in contrast, with worse clinical outcome in elderly patients. In conclusion, for the first time, we demonstrated prognostic impact of epigenetic biomarkers that reverses with advancing age. This new insight supports the hypothesis that CRC biology is different in young vs elderly patients and emphasizes the importance of focusing on age-related effects in CRC.

Treatment strategies and survival of older breast cancer patients - an international comparison between the Netherlands and Ireland

OBJECTIVES

Forty percent of breast cancers occur among older patients. Unfortunately, there is a lack of evidence for treatment guidelines for older breast cancer patients. The aim of this study is to compare treatment strategy and relative survival for operable breast cancer in the elderly between The Netherlands and Ireland.

MATERIAL AND METHODS

From the Dutch and Irish national cancer registries, women aged ≥65 years with non-metastatic breast cancer were included (2001-2009). Proportions of patients receiving guideline-adherent locoregional treatment, endocrine therapy, and chemotherapy were calculated and compared between the countries by stage. Secondly, 5-year relative survival was calculated by stage and compared between countries.

RESULTS

Overall, 41,055 patients from The Netherlands and 5,826 patients from Ireland were included. Overall, more patients received guideline-adherent locoregional treatment in The Netherlands, overall (80% vs. 68%, adjusted p<0.001), stage I (83% vs. 65%, p<0.001), stage II (80% vs. 74%, p<0.001) and stage III (74% vs. 57%, P<0.001) disease. On the other hand, more systemic treatment was provided in Ireland, where endocrine therapy was prescribed to 92% of hormone receptor-positive patients, compared to 59% in The Netherlands. In The Netherlands, only 6% received chemotherapy, as compared 24% in Ireland. But relative survival was poorer in Ireland (5 years relative survival 89% vs. 83%), especially in stage II (87% vs. 85%) and stage III (61% vs. 58%) patients.

CONCLUSION

Treatment for older breast cancer patients differed significantly on all treatment modalities between The Netherlands and Ireland. More locoregional treatment was provided in The Netherlands, and more systemic therapy was provided in Ireland. Relative survival for Irish patients was worse than for their Dutch counterparts. This finding should be a strong recommendation to study breast cancer treatment and survival internationally, with the ultimate goal to equalize the survival rates for breast cancer patients across Europe.

Distinct prognostic values of ALDH1 isoenzymes in breast cancer

Aldehyde dehydrogenase 1 (ALDH1), also known as aldehyde dehydrogenase 1 family, is composed of six enzymes that are expressed at high levels in stem cells and are involved in the regulation of stem cell function. Increased ALDH1 activity has been found in the stem cell populations of leukemia and some solid tumors including breast cancer (BC). However, which ALDH1's isoenzymes are contributing to ALDH1 activity has not been determined. In addition, the prognostic value of individual ALDH1 isoenzyme is not clear. In the current study, we investigated the prognostic value of ALDH1 isoenzymes in BC patients through "the Kaplan-Meier plotter" (KM plotter) database, in which updated gene expression data and survival information are from a total of 3455 BC patients. ALDH1A1 messenger RNA (mRNA) high expression was found to be correlated to worsen overall survival (OS) for all BC patients. ALDH1A2 and ALDH1L1 mRNA high expressions were found to be correlated to better OS for all BC patients. Both of ALDH1A3 and ALDH1B1 mRNA high expressions were not found to be correlated to OS for all BC patients. These results strongly support that ALDH1A1 was only a biomarker for predicting poor survival of BC patients among ALDH1 isoenzymes. ALDH1A1 might be a major contributor of ALDH1 activity in BC, since only ALDH1A1 mRNA high expression was found to be significantly correlated to worsen OS for all BC patients.

Correlations of ALDH1 expression with molecular subtypes and ABCG2 in breast cancer

OBJECTIVE

To investigate the correlations of aldehyde dehydrogenase 1 (ALDH1) expression with the molecular subtypes and ATP-binding cassette subfamily G member 2 (ABCG2) in breast cancer.

METHODS

The specimens from 179 cases of breast cancer were divided into five molecular subtypes according to the immunological markers (ER, PR, HER2 and CK5/6), which were luminal A, luminal B, Her2-enriched, basal-like and breast-like subtype, respectively. The expressions of ALDH1 and ABCG2 of the specimens were detected with immunohistochemical staining, and the relationship between them as well as their relations with the clinicopathological factors of breast cancer was analyzed.

RESULTS

Of the 179 cases of breast cancer, ALDH1 positive expression was present in 43 cases (24.0%). The AIDH1 expression rate showed significant difference among the different molecular subtypes of breast cancer (P=0.003). The positive expression rate of ALDH1 was 16.7% (17/102) in luminal A subtype, 21.4% (3/14) in luminal B subtype, 54.5% (13/22) in Her2-enriched subtype, 33.3% (8/24) in basal-like subtype, and 17.6% (3/17) in breast-like subtype, respectively. The positive expression of ALDH1 had no significant relation with the ABCG2 expression (P=0.052). Both ALDH1 and ABCG2 expressions were related to the administration of preoperative chemotherapy (P=0.027 and P=0.033) and ALDH1 expression was related to the HER2 expression (P=0.006).

CONCLUSIONS

With a high expression level of ALDH1, HER2 overexpression, basal-like and ABCG2-positive types were associated with poor outcomes and treatment resistance in breast cancer. The expression of ALDH1 has no obvious relation with ABCG2.

ALDH1A1 expression correlates with clinicopathologic features and poor prognosis of breast cancer patients: a systematic review and meta-analysis

BACKGROUND

Aldehyde dehydrogenase 1 family member A1 (ALDH1A1) has been identified as a putative cancer stem cell (CSC) marker in breast cancer. However, the clinicopathological and prognostic significance of this protein in breast cancer patients remains controversial.

METHODS

This meta-analysis was conducted to address the above issues using 15 publications covering 921 ALDH1A1(+) cases and 2353 controls. The overall and subcategory analyses were performed to detect the association between ALDH1A1 expression and clinicopathological/prognostic parameters in breast cancer patients.

RESULTS

The overall analysis showed that higher expression of ALDH1A1 is associated with larger tumor size, higher histological grade, greater possibility of lymph node metastasis (LNM), higher level expression of epidermal growth factor receptor 2 (HER2), and lower level expression of estrogen receptor (ER)/progesterone receptor (PR). The prognosis of breast cancer patients with ALDH1A1(+) tumors was poorer than that of the ALDH1A1(-) patients. Although the relationships between ALDH1A1 expression and some clinicopathological parameters (tumor size, LNM, and the expression of HER2) was not definitive to some degree when we performed a subcategory analysis, the predictive values of ALDH1A1 expression for histological grade and survival of breast cancer patients were significant regardless of the different cutoff values of ALDH1A1 expression, the different districts where the patients were located, the different clinical stages of the patients, the difference in antibodies used in the studies, and the surgery status.

CONCLUSIONS

Our results indicate that ALDH1A1 is a biomarker to predict tumor progression and poor survival of breast cancer patients. This marker should be taken into consideration in the development of new diagnostic and therapeutic program for breast cancer.

Expression of matrix metalloproteinase-2 and 9 in cervical intraepithelial neoplasia and cervical carcinoma among different age groups of premenopausal and postmenopausal women

PURPOSE

The objective was to study the gelatinolytic activity of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in preinvasive and invasive carcinoma of the uterine cervix. The expressions were analysed against different age groups, as to demonstrate whether the expression of MMP-2 and MMP-9 is an early or a late event during the progression of cervical cancer. Additionally, the diagnostic accuracy of MMP-2 and MMP-9 was evaluated with ROC curve.

METHODS

A total number of 180 samples of cervical tissue were studied for MMP-2 and MMP-9 gelatinolytic activity. The cases were selected as to include 63 normal cases, 94 CIN cases and 23 cervical carcinoma cases. Among 94 CIN cases, 40 were CIN1, 26 were CIN2 and 28 were CIN3, as reported by histopathology. The gelatinolytic activities of MMP-2 and MMP-9 were evaluated by gelatin zymography in premenopausal and postmenopausal groups.

RESULTS

MMP-2 expressions (latent and active) were very low in control samples, followed by increase in CIN1, decrease in CIN2 and further increase in advance stages. MMP-9 had also shown the same expression pattern that of MMP-2. While comparing the expression of MMP-2 and MMP-9 in different age groups, we found initial CIN stages were prevalent in early age that expressed considerable amount of MMP-2 and MMP-9, and advance stages of carcinoma cervix were prevalent at an elderly age.

CONCLUSION

Both MMP-2 and MMP-9 have role in cancer progression and remodelling of the ectocervix. Although expression level varies intricately, a distinctive ROC curve demonstrated MMP-2 active form and MMP-9 form could be used in diagnostic purpose in detection of cervical lesion and cancer.

ALDH1 expression is enriched in breast cancers arising in young women but does not predict outcome

Background:

Tumours arising in younger women appear to be biologically more aggressive and tend to have a poorer outcome. Being relatively resistant to conventional treatments, breast cancer stem cells (CSCs) have been postulated as a possible cause of disease recurrence after treatment. In this study, we used ALDH1 as a CSC marker and determined whether ALDH1 expression correlated with clinical outcome in young women with breast cancer.

Methods:

The expression of ALDH1 was evaluated through immunohistochemistry on microarrayed cores obtained from 141 consecutive patients up to 35 years of age.

Results:

The expression of ALDH1 was observed in 25% (35 of 141) of tumours, in a median of 5% of cells. Younger women were 14 times more likely to have ALDH1-positive tumours (P<0.01, OR 14.4, 95% CI 4.34–48.09). The ALDH1 correlated independently with ER negativity (P=0.01, OR 0.33, 95% CI 0.15–0.77). There was no correlation with disease recurrence or breast cancer-related deaths.

Conclusion:

In younger women, ALDH1 was more highly expressed, and it correlated with ER negativity. It, however, did not predict survival in this study.

The expression of aldehyde dehydrogenase 1 in invasive primary breast tumors and axillary lymph node metastases is associated with poor clinical prognosis

The enzyme aldehyde dehydrogenase 1 (ALDH1) has been reported as a biomarker for identifying cancer stem cells. Previous studies have shown that ALDH1 expression in primary breast cancers was associated with poor clinical prognosis. In this study, we aimed to determine whether ALDH1 expression in axillary lymph node metastases (ALNM) of breast cancer patients was also associated with poor prognosis. Expression of ALDH1, ER, PgR, HER2 and KI-67 was examined in primary tumors and ALNM of 161 patients with invasive breast cancer. Survival analysis and multivariate analysis were used to determine the relationship between ALDH1 expression and clinical prognosis. Patients with positive ALDH1 expression in primary tumors and in ALNM had significantly shorter relapse-free survival (RFS) times and overall survival (OS) times compared to those whose tissues were ALDH1 negative. ALDH1-positivity in primary tumors was significant both in univariate and multivariate analyses of RFS and OS. ALDH1 expression in ALNM was significant in a univariate analysis of RFS and OS but not in a multivariate analysis of RFS and OS. We conclude that the expression of ALDH1 in primary breast tumors or ALNM may be one potential risk factor for poor, long-term outcomes.