Aldehyde dehydrogenase 1 family: A potential molecule target for diseases.

Aldehyde dehydrogenase 1 (ALDH1), a crucial aldehyde metabolizing enzyme, has six family members. The ALDH1 family is expressed in various tissues, with a significant presence in the liver. It plays a momentous role in several pathophysiological processes, including aldehyde detoxification, oxidative stress, and lipid peroxidation. Acetaldehyde detoxification is the fundamental function of the ALDH1 family in participating in vital pathological mechanisms. The ALDH1 family can catalyze retinal to retinoic acid (RA) that is a hormone-signaling molecule and plays a vital role in the development and adult tissues. Furthermore, there is a need for further and broader research on the role of the ALDH1 family as a signaling molecule. The ALDH1 family is widely recognized as a cancer stem cell (CSC) marker and plays a significant role in the proliferation, invasion, metastasis, prognosis, and drug resistance of cancer. The ALDH1 family also participates in other human diseases, such as neurodegenerative diseases, osteoarthritis, diabetes, and atherosclerosis. It can inhibit disease progression by inhibiting/promoting the expression/activity of the ALDH1 family. In this review, we comprehensively analyze the tissue distribution, and functions of the ALDH1 family. Additionally, we review the involvement of the ALDH1 family in diseases, focusing on the underlying pathological mechanisms and briefly talk about the current status and development of ALDH1 family inhibitors. The ALDH1 family presents new possibilities for treating diseases, with both its upstream and downstream pathways serving as promising targets for therapeutic intervention. This offers fresh perspectives for drug development in the field of disease research.

CD24: A Marker for an Extended Expansion Potential of Urothelial Cancer Cell Organoids In Vitro?

BACKGROUND: Bladder cancer is the most cost-intensive cancer due to high recurrence rates and long follow-up times. Bladder cancer organoids were considered interesting tools for investigating better methods for the detection and treatment of this cancer. METHODS: Organoids were generated from urothelial carcinoma tissue samples, then expanded and characterized; the expression of immune modulatory antigens and tumor stem cells markers CD24 and CD44 was explored in early (P ≤ 3) and later (P ≥ 5) passages (P) by immunofluorescence and by quantitative PCR of cDNA. The expression of these factors was investigated in the corresponding cancer tissue samples by immunohistochemistry. RESULTS: The expression of the PD-L1 was detected on some but not all organoids. CD276 and CD47 were observed on organoids in all passages investigated. Organoids growing beyond passage 8 expressed both CD24 and CD44 at elevated levels in early and late cultures. Organoids proliferating to the eighth passage initially expressed both CD24 and CD44, but lost CD24 expression over time, while CD44 remained. Organoids growing only up to the 6th passage failed to express CD24 but expressed CD44. CONCLUSIONS: The data indicate that the expression of CD24 in urothelial cancer cell organoids may serve as an indicator for the prolonged proliferation potential of the cells.

Overexpression of a panel of cancer stem cell markers enhances the predictive capability of the progression and recurrence in the early stage cholangiocarcinoma.

BACKGROUND: Cancer recurrence is the important problem of cholangiocarcinoma (CCA) patients, lead to a very high mortality rate. Therefore, the identification of candidate markers to predict CCA recurrence is needed in order to effectively manage the disease. This study aims to examine the predictive value of cancer stem cell (CSC) markers on the progression and recurrence of CCA patients. METHODS: The expression of 6 putative CSC markers, cluster of differentiation 44 (CD44), CD44 variant 6 (CD44v6), CD44 variants 8-10 (CD44v8-10), cluster of differentiation 133 (CD133), epithelial cell adhesion molecule (EpCAM), and aldehyde dehydrogenase 1A1 (ALDH1A1), was investigated in 178 CCA tissue samples using immunohistochemistry (IHC) and analyzed with respect to clinicopathological data and patient outcome including recurrence-free survival (RFS) and overall survival (OS). The candidate CSC markers were also investigated in serum from CCA patients, and explored for their predictive ability on CCA recurrence. RESULTS: Elevated protein level of CD44 and positive expression of CD44v6 and CD44v8-10 were significantly associated with short RFS and OS, while high levels of ALDH1A1 were correlated with a favorable prognosis patient. The elevated CD44v6 level was also correlated with higher tumor staging, whereas a decreasing level of ALDH1A1 was correlated with lower tumor staging. The levels of CD44, CD44v6 and CD44v8-10 were also correlated and were associated with a poor outcome. Furthermore, soluble CD44, CD44v6, CD44v8-10 and EpCAM were significantly increased in the recurrence group for early stage CCA; they also correlated with high levels of the tumor marker CA19-9. Elevated levels of CD44, CD44v6, CD44v8-10 or EpCAM alone or in combination has the potential to predict CCA recurrence. CONCLUSIONS: The overexpression of CD44, CD44v6, CD44v8-10 and EpCAM increases predictability of post-operative CCA recurrence. Moreover, the overexpression of the panel of CSC markers combined with CA19-9 could improve our predictive ability for tumor recurrence in early stage CCA patients. This result may be beneficial for the patients in order to predict the outcome after treatment and may be useful for clinical intervention in order to improve patient survival.

The predominant expression of cancer stem cell marker ALDH1A3 in tumor infiltrative area is associated with shorter overall survival of human glioblastoma.

BACKGROUND: ALDH1A3 is a cancer stem cell marker in neoplasms including glioblastoma (GBM). However, the comprehensive role of ALDH1A3 in GBM remains unclear. This study attempted to investigate the expression of ALDH1A3 in human GBM tissues and its association with clinical parameters. METHODS: Thirty primary GBM and 9 control were enrolled in this study. ALDH1A3 mRNA and protein expression levels were detected by RT2-PCR and western blot, respectively. Immunohistochemistry and immunofluorescence staining were performed to evaluate the regional and cellular expression manner of ALDH1A3. The association of ALDH1A3 expression with multiple clinical parameters was analyzed. RESULTS: ALDH1A3 protein level, but not mRNA level, in a subgroup of GBM was significantly higher than that in the control group. ALDH1A3 immunoreactivity was detected heterogeneously in individual GBMs. Fifteen of 30 cases showed a positive of ALDH1A3 immunoreactivity which was predominantly observed in the tumor infiltrative area (TI). Double immunofluorescence staining revealed a co-localization of ALDH1A3 with GFAP in glial-shaped cells and in tumor cells. ALDH1A3 immunoreactivity was often merged with CD44, but not with CD68. Moreover, ALDH1A3 expression was positively associated with the tumor edema grade and inversely with overall survival (OS) (median OS: 16 months vs 10 months), but with neither MGMT promoter methylation status nor Ki67 index in GBM. An upregulation of ALDH1A3 was accompanied by a reduced expression of STAT3ß and p-STAT3ß. CONCLUSIONS: Inter- and intra-tumoral heterogeneous expression of ALDH1A3 was exhibited in GBMs. A high immunoreactivity of ALDH1A3 in tumor infiltrative area was associated with shorter OS, especially in patients with MGMT promoter methylation. Our findings propose ALDH1A3 not only as a predictive biomarker but also as a potential target for personalized therapy of GBM.

Augmented CD133 expression in distal margin correlates with poor prognosis in colorectal cancer.

Pathological assessment of excised tumour and surgical margins in colorectal cancer (CRC) play crucial role in prognosis after surgery. Molecular assessment of margins could be more sensitive and informative than conventional histopathological analysis. Considering this view, we evaluated the distal surgical margins for expression of cancer stem cell (CSC) markers. Cellular and molecular assessment of normal, tumour and distal margin tissues were performed by flow cytometry, real-time q-PCR and immuno-histochemical analysis for CRC patients after tumour excision. CRC patients were evaluated for expression of CSC markers in their normal, tumour and distal tissues. Flow cytometry assay revealed CD133 and CD44 enriched cells in distal margin and tumour compared to normal colorectal tissues, which was further confirmed by immunohistochemistry. Most importantly, immunohistochemistry also revealed the enrichment of CSC markers expression in pathologically negative distal margins. Patients with distal margin enriched for CD133 expression showed an increased recurrence rate and decreased disease-free survival. This study proposes that although distal margin seems to be tumour free in conventional histopathological analysis, it could harbour cells enriched for CSC markers. Further CD133 could be a promising molecule to be used in molecular pathology for disease prognosis after surgery in CRC patients.

Heterogeneity of Colon Cancer Stem Cells.

Colorectal cancer (CRC) remains the fourth leading cause of cancer death worldwide. Cancer stem cells (CSCs) have attracted a great deal of interest because of their potential clinical implications in a range of cancers, including CRC. CSCs were initially considered to be cell populations with well-defined phenotypic and molecular characteristics. However, accumulating evidence suggests that CSCs represent a phenotypically and functionally heterogeneous population. Recent studies also demonstrate colorectal CSCs to be dynamic rather than static populations that are continuously altered by various extrinsic factors in addition to intrinsic cellular factors such as genetic and epigenetic alterations. Thus, CSCs do not represent a fixed target population any longer, and their heterogeneous and dynamic nature present a serious problem in establishing specific therapeutic strategies. This chapter summarizes past and current literature related to CSC population heterogeneity and dynamics in CRC tissues, including evidence of the presence of distinct CSC subpopulations and signaling pathways and intra- and extra-tumoral factors involved in the regulation of CSCs in cancer tissues.

CEACAM1 is associated with recurrence after hepatectomy for colorectal liver metastasis.

BACKGROUND: Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is re-expressed at the invasion front of colorectal cancer. CEACAM1 expression at metastatic sites remains to be investigated. The current study aims to clarify the association between CEACAM1 expression and recurrence after hepatectomy of colorectal liver metastasis and to address whether CEACAM1 induces tumor-initiating properties needed for growth at metastatic sites. METHODS: Immunohistochemical analyses for CEACAM1 were performed in 67 patients with liver metastasis of colorectal cancer who had undergone curative hepatectomy. The risk factors for postoperative recurrence were calculated based on a CEACAM1 cytoplasmic domain isoform at the primary tumor invasion front. To investigate the effects of CEACAM1 cytoplasmic isoforms on HT29 and HCT116 colorectal cancer cells, Western blotting for CD44 and CD133, flow cytometry for ALDH1 activity, and soft-agar colony formation assay were performed. RESULTS: CEACAM1 long (CEACAM1-L) and short (CEACAM1-S) cytoplasmic domain isoforms are strongly expressed on cancer cells in the liver metastases. Enhanced CEACAM1-S expression in the state of CEACAM1-L dominance at the primary tumor invasion front was an independent factor for colorectal cancer recurrence after curative hepatectomy. CEACAM1-4S-transfected HT29 and HCT116 cells had significantly higher CD44 expression and ALDH1 activity and increased the growth in anchorage-independent condition. CONCLUSIONS: High expression of CEACAM1-S at the primary lesion invasion front is associated with recurrence and prognosis of patients with colorectal liver metastasis after curative hepatectomy. The expression of CEACAM1-4S enhances the tumor-initiating property of colorectal cancer cells.

Promoting biological similarity by collagen microfibers in 3D colorectal cancer-stromal tissue: Replicating mechanical properties and cancer stem cell markers.

The extracellular matrix (ECM) of cancer tissues is rich in dense collagen, contributing to the stiffening of these tissues. Increased stiffness has been reported to promote cancer cell proliferation, invasion, metastasis, and prevent drug delivery. Replicating the structure and mechanical properties of cancer tissue in vitro is essential for developing cancer treatment drugs that target these properties. In this study, we recreated specific characteristics of cancer tissue, such as collagen density and high elastic modulus, using a colorectal cancer cell line as a model. Using our original material, collagen microfibers (CMFs), and a constructed three-dimensional (3D) cancer-stromal tissue model, we successfully reproduced an ECM highly similar to in vivo conditions. Furthermore, our research demonstrated that cancer stem cell markers expressed in the 3D cancer-stromal tissue model more closely mimic in vivo conditions than traditional two-dimensional cell cultures. We also found that CMFs might affect an impact on how cancer cells express these markers. Our 3D CMF-based model holds promise for enhancing our understanding of colorectal cancer and advancing therapeutic approaches. STATEMENT OF SIGNIFICANCE: Reproducing the collagen content and stiffness of cancer tissue is crucial in comprehending the properties of cancer and advancing anticancer drug development. Nonetheless, the use of collagen as a scaffold material has posed challenges due to its poor solubility, hindering the replication of a cancer microenvironment. In this study, we have successfully recreated cancer tissue-specific characteristics such as collagen density, stiffness, and the expression of cancer stem cell markers in three-dimensional (3D) colorectal cancer stromal tissue, utilizing a proprietary material known as collagen microfiber (CMF). CMF proves to be an ideal scaffold material for replicating cancer stromal tissue, and these 3D tissues constructed with CMFs hold promise in contributing to our understanding of cancer and the development of therapeutic drugs.

Effects of Topoisomerase II alpha Inhibition on Oral Cancer Cell Metabolism and Cancer Stem Cell Function.

Background: Topoisomerase IIα (TOP2A), is an enzyme involved in DNA replication, transcription, recombination, and chromatin remodeling and is found in a variety of cancers. However, the role of TOP2A regulation in oral cancer progression is not fully explained. We investigated the effect of TOP2A inhibition on cell survival, metabolism, and cancer stem cell self-renewal function in oral cancer cells. Methods: Oral carcinoma cell line SCC25 was cultured in complete DMEM/F12 media and treated with 5µM of Etoposide (Topoisomerase II inhibitor) for 48h. The critical parameters of cellular metabolism, including extracellular acidification rate (ECAR) and mitochondrial oxidative phosphorylation based on the oxygen consumption rate of cancer cells were assessed using Seahorse assay. Western blotting was performed to assess the proteins that are associated with proliferation (Survivin, IL-6) and cancer stem cell function (Oct4, Sox2) in cell lysates prepared from control and etoposide treated groups. Statistical analysis was performed using One-way ANOVA with Dunnett's multiple comparisons test. Results: The protein expression of TOP2A was significantly (P<0.05) inhibited by etoposide. Additionally, TOP2A inhibition decreased the mitochondrial respiratory parameters including basal respiration, maximal respiration and ATP production. However, TOP2A inhibition has no impact on glycolytic function. Moreover, the proliferative marker survivin and IL-6 showed a significant (P<0.05) decrease after TOP2A inhibition. Conversely, the protein expression of cancer stem cell markers Oct-4 and Sox 2 were not altered. Conclusion: These results indicate that inhibition of TOP2A is more efficacious by decreasing the mitochondrial metabolic reprogramming and thereby downregulating the key anti-apoptotic and pro-survival mediators. Thus, TOP2A represents an ideal therapeutic target and offers a potential treatment strategy for OSCC.

CD133 expression in oral lichen planus correlated with the risk for progression to oral squamous cell carcinoma.

Oral lichen planus (OLP) is a potentially malignant disorder associated with an increased risk for progression to oral squamous cell carcinoma (OSCC). The objective of this study to determine protein expression of cancer stem cell marker CD133 in tissue samples of patients with OLP and evaluate the correlation between CD133 expression and the risk of progression to OSCC. In this longitudinal case-control study, a total of 110 patients with OLP who received a mean follow-up of 56 months were enrolled, including 100 patients who did not progress to OSCC and 10 patients who had progressed to OSCC. CD133 expression was determined using immunohistochemistry in samples from these patients. 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 CD133 expression was observed in 29% cases of nonprogressing OLP and in 80% cases of progressing OLP (P = .002). CD133 was not expressed in normal oral mucosa, but it positively expressed in the 100% cases of OSCC. Logistic regression analysis revealed that the risk of malignant progression in the patients with CD133-positive expression was significantly higher than those with CD133 negativity (odds ratio, 9.79; 95% confidence interval, 1.96-48.92; P = .005). Collectively, CD133 expression was significantly associated with malignant progression in a longitudinal series of patients with OLP. Our findings suggested that CD133 may serve as a novel candidate biomarker for risk assessment of malignant potential of OLP.

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.

Clinical Significance of Cancer Stem Cell Markers in Primary and Metastatic Tissues in Patients With Breast Cancer.

BACKGROUND/AIM: This study aimed to examine the clinical significance of the protein expression of the cancer stem cell (CSC) markers ALDH1A1, CD133, CD44, and MSI-1 in primary and metastatic tissues of patients with breast cancer (BC). PATIENTS AND METHODS: ALDH1A1, CD133, CD44, and MSI-1 protein expression in pairs of primary and metastatic tissues of 55 patients with BC with metastases treated at Kanagawa Cancer Center between January 1970 and December 2016 were evaluated using immunohistochemical assay and their association with clinicopathological factors and survival was examined. RESULTS: There were no significant differences in CSC marker expression rates between primary and metastatic tissues for any CSC markers. Regarding the relationship between CSC marker expression in primary tissues and survival, patients with high CD133 expression had significantly lower recurrence-free survival (DFS) and overall survival. On multivariate analysis, they were also a poor independent predictor of DFS (hazard ratio=4.993, 95%CI=2.189-11.394, p=0.0001). In contrast, there was no significant association between the expression of any CSC marker in metastatic tissues and survival. CONCLUSION: CD133 expression in the primary BC tissue may be a useful risk factor for recurrence in patients with BC.

Clinicopathological relevance of stem cell marker growth and differentiation factor 3 in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is the second leading cause of cancer-related deaths in Iran, often diagnosed in advanced stages with a poor prognosis. Growth and differentiation factor 3 (GDF3) is a member of the transforming growth factor-beta (TGF-ß) superfamily. It acts as an inhibitor of bone morphogenetic proteins (BMPs) signaling pathway associated with pluripotent embryonic and cancer stem cells (CSCs) characteristics. Since its expression in ESCC has not yet been evaluated, the clinicopathological relevance of GDF3 expression was elucidated in ESCC patients. Expression of GDF3 in tumor tissues from 40 ESCC patients was compared to the related margin normal tissues by relatively comparative real-time polymerase chain reaction (PCR). Glyceraldehydes 3-phosphate dehydrogenase (GAPDH) was used as the endogenous control. Likewise, the function of GDF3 in the differentiation and development of embryonic stem cells (ESCs) was also reviewed. GDF3 was significantly overexpressed in 17.5% of tumors and a significant correlation between GDF3 expression and the depth of tumor invasion was observed (P = 0.032). The results suggest that GDF3 expression is likely to have substantial roles in the progression and invasiveness behavior of ESCC. Having considered the importance of CSC markers identification and their exploitation in targeted cancer therapy, GDF3 may be introduced as a promising therapeutic target to inhibit the invasion of tumor cells in ESCC.

1,2,3,4,6-Penta-O-galloyl-ß-D-glucose Inhibits CD44v3, a cancer stem cell marker, by regulating its transcription factor, in human pancreatic cancer cell line.

Inhibition of cluster of differentiation 44 (CD44), a pancreatic cancer stem cell (CSC) marker, is a potential treatment for pancreatic ductal adenocarcinoma (PDAC). In this study, we evaluated the effect of 1,2,3,4,6-penta-O-galloyl-ß-D-glucose (PGG), a gallotannin contained in various medicinal plants, on CD44 standard (CD44s) and CD44 variant 3 (CD44v3) in Mia-PaCa-2, human pancreatic cancer cells and explored the underlying mechanisms. PGG showed cytotoxic effects and inhibited the proliferation of Mia-PaCa-2 cells. It also inhibited clonogenic activity, adhesion to fibronectin, and cell migration, which are characteristics of CSCs. PGG inhibited the expression of CD44s and CD44v3 by inducing the phosphorylation of p53 and suppressing NF-κB and Foxo3. Inhibition of Foxo3 induces CD44v3 ubiquitination. Indeed, PGG increased proteasome activity and promoted CD44v3 ubiquitination. PGG downregulated the CSC regulatory factors Nanog, Oct-4, and Sox-2, which act downstream of CD44v3 signaling. These data indicate that PGG may have therapeutic effects in pancreatic cancer mediated by inhibition of CSC markers.

Research Progress of DCLK1 Inhibitors as Cancer Therapeutics.

Doublecortin-like kinase 1 (DCLK1) has emerged over the last decade as a unique stem cell marker within gastrointestinal tissues. Evidence from mouse models shows that high Dclk1 expression denotes a population of cells that promote tissue regeneration and serve as potential cancer stem cells. Moreover, since certain DCLK1 isoforms are overexpressed in many cancers and not normal cells, targeting the expression or kinase activity of DCLK1 has the potential to inhibit cancer cell growth. Here, we review the evidence for DCLK1 as a prospective cancer target including its isoform-specific expression and mutational status in human cancers. We further discuss the challenges and current progress in the development of small molecule inhibitors of DCLK1.

ALCAM/CD166: A pleiotropic mediator of cell adhesion, stemness and cancer progression.

Activated Leukocyte Cell Adhesion Molecule (ALCAM/CD166) is a glycoprotein involved in homotypic and heterotypic cell adhesion. ALCAM can be proteolytically cleaved at the cell surface by metalloproteases, which generate shedding of its ectodomain. In various tumors, ALCAM is overexpressed and serves as a valuable prognostic marker of disease progression. Moreover, CD166 has been identified as a putative cancer stem cell marker in particular cancers. Herein, we summarize biochemical aspects of ALCAM, including structure, proteolytic shedding, alternative splicing, and specific ligands, and integrate this information with biological functions of this glycoprotein including cell adhesion, migration and invasion. In addition, we discuss different patterns of ALCAM expression in distinct tumor types and its contribution to tumor progression. Finally, we highlight the role of ALCAM as a cancer stem cell marker and introduce current clinical trials associated with this molecule. Future studies are needed to define the value of shed ALCAM in biofluids or ALCAM isoform expression as prognostic biomarkers in tumor progression.

The Prognostic Value of Cancer Stem Cell Markers in Cervical Cancer: A Systematic Review and Meta-Analysis.

OBJECTIVES: Prognostic biomarkers in cervical cancer are widely investigated, including cancer stem cell (CSC) markers. However, their significance remains uncertain. This study aimed to determine the role of cervical cancer stem cell (CCSC) markers for survival. MATERIALS AND METHODS: We conducted a systematic review and meta-analysis (PROSPERO CRD42021237072) of studies reporting CCSC markers as the prognostic predictor based on PRISMA guidelines. We included English articles investigating associations of CCSCs expression in tissue tumor with overall survival (OS) or disease-free survival (DFS) from PubMed, EBSCO, and The Cochrane Library databases. The quality of studies was analyzed based on Newcastle-Ottawa Quality Assessment Scale. RESULTS: From 413 publications, after study selection with inclusion and exclusion criteria, 22 studies were included. High expressions of CCSC markers were associated with poor OS and DFS (HR= 1.05, 95% CI: 1.03 - 1.07, P <0.0001; HR= 1.31, 95% CI: 1.09 - 1.17, P <0.00001; respectively). Sub-analysis of individual CCSC markers indicated significant correlations between CD44 (HR= 1.14, 95% CI: 1.07 - 1.22, P 0.0001), SOX2 (HR= 1.58, 95% CI: 1.17 - 2.14, P 0.003), OCT4 (HR= 1.03, 95% CI: 1.01 - 1.06, P 0.008), ALDH1 (HR= 1.36, 95% CI: 1.13 - 1.64, P 0.001), and CD49f (HR= 3.02, 95% CI: 1.37 - 6.64, P 0.006) with worse OS; OCT4 (HR= 1.14, 95% CI 1.06 - 1.22, P 0.0003), SOX2 (HR= 1.11, 95% CI: 1.06 - 1.16, P <0.0001), and ALDH1 (HR= 1.22, 95% CI: 1.10 - 1.35, P 0.0002) with poor DFS. We did not conduct a meta-analysis for MSI-1 and CK17 because only one study investigated those markers. CONCLUSION: Expressions of OCT4, SOX2, and ALDH1 were associated with poor OS and DFS in cervical cancer tissue. These markers might have potential roles as prognostic biomarkers to predict unfavorable survival.

Role of hypoxia inducible factor-1 in cancer stem cells (Review).

Cancer stem cells (CSCs) have been found to play a decisive role in cancer recurrence, metastasis, and chemo­, radio­ and immuno­resistance. Understanding the mechanism of CSC self­renewal and proliferation may help overcome the limitations of clinical treatment. The microenvironment of tumor growth consists of a lack of oxygen, and hypoxia has been confirmed to induce cancer cell invasion, metastasis and epithelial­mesenchymal transition, and is usually associated with poor prognosis and low survival rates. Hypoxia inducible factor­1 (HIF­1) can be stably expressed under hypoxia and act as an important molecule to regulate the development of CSCs, but the specific mechanism remains unclear. The present review attempted to explain the role of HIF­1 in the generation and maintenance of CSCs from the perspective of epigenetics, metabolic reprogramming, tumor immunity, CSC markers, non­coding RNA and signaling pathways associated with HIF­1, in order to provide novel targets with HIF­1 as the core for clinical treatment, and extend the life of patients.

CD44 expression enhances chemoresistance and implies occult micrometastases after conversion hepatectomy for initially unresectable colorectal liver metastases.

AIM: The objective of this study was to examine the clinical and biological significance of CD44 expression in conversion hepatectomy for initially unresectable colorectal liver metastases. METHODS: Fifty-four patients who received chemotherapy followed by hepatectomy (conversion hepatectomy) for initially unresectable liver metastases were enrolled. CD44 expression and its clinical significance were examined in 52 resected specimens; two specimens revealed no residual cancer cells. The biological significance of CD44 expression in the chemoresistance response to fluorouracil, oxaliplatin or irinotecan, three major anti-cancer agents for colon cancer in the clinical setting, was examined using colon cancer cell lines. RESULTS: Membrane CD44 expression in the residual cancer cells after chemotherapy for colorectal liver metastases was detectable in 19 patients (37%), and was significantly associated with high proliferative activity represented by Ki-67 expression (P = 0.003). CD44 expression was also significantly associated with shorter disease-free survival and worse overall survival after hepatectomy (hazard ratio and P-values were 2.570, 0.007 and 3.457, 0.026, respectively). In SW480 and HT29 colon cancer cells, siRNA-mediated CD44 knockdown attenuated cell growth. Additionally, CD44 knockdown overcame chemoresistance in response to fluorouracil and oxaliplatin with enhanced apoptosis and p27 upregulation, respectively. For irinotecan, CD44 knockdown showed no additional effect in chemoresistance. CONCLUSIONS: CD44 enhances chemoresistance in response to anti-cancer drugs (fluorouracil and oxaliplatin) in colon cancer cells. CD44 expression in liver metastases after chemotherapy implies the presence of occult micrometastases and is a worse prognostic factor in patients with conversion hepatectomy for initially unresectable colorectal liver metastases.

Clinicopathological correlation of cancer stem cell markers Oct-4 and CD133 expression as prognostic factor in malignant lesions of gallbladder: An immunohistochemical study.

BACKGROUND: Gallbladder cancer (GBC) is the most frequent biliary tract cancer, with high morbidity and poor prognosis, and shows early metastasis and invasiveness. No reliable biomarkers are available for detection of GBC progression. AIM: To investigate the immunohistochemical expression of Oct-4 and CD133 in malignant and nonneoplastic lesions of gallbladder and to analyze the clinical significance of the expressions related to clinicopathological parameters. SETTINGS AND DESIGN: This is a prospective case control study, conducted in medical college background. MATERIALS AND METHODS: A total of 103 cases of gallbladder were grouped into malignant lesions (n = 48) and nonneoplastic lesions (simple epithelial hyperplasia; n = 35 and chronic cholecystitis; n = 20). All tissue samples were evaluated for expression of Oct-4 and CD133 using immunohistochemistry in an effort to elucidate the correlation between their expressions with clinicopathological parameters. STATISTICAL ANALYSIS: The final score was calculated by multiplying the intensity to the percentage of positive cells. The scores ≥2 were considered as positive. RESULTS: Significant positive correlation of higher expression levels of Oct-4 and CD133 were observed in malignant as compared to nonneoplastic lesions of gallbladder (P < 0.0001). High expression of Oct-4 and CD133 were significantly associated with tumor grading (Oct-4, P = 0.04; CD133, P = 0.02), staging (Oct-4, P = 0.03; CD133, P = 0.02), and liver metastasis (Oct-4, P = 0.01; CD133, P = 0.007). Significantly reduced survival was observed with high expression of Oct-4 (P = 0.002). No significant correction was observed between CD 133 and survival. CONCLUSION: This study revealed that high expression level of Oct-4 may provide a new insight for the prognosis of the disease in terms of clinical staging and grade.