The role of CD24 in various human epithelial neoplasias

Biomarkers in Cancer Detection, Diagnosis, and Prognosis

Biomarkers are vital in healthcare as they provide valuable insights into disease diagnosis, prognosis, treatment response, and personalized medicine. They serve as objective indicators, enabling early detection and intervention, leading to improved patient outcomes and reduced costs. Biomarkers also guide treatment decisions by predicting disease outcomes and facilitating individualized treatment plans. They play a role in monitoring disease progression, adjusting treatments, and detecting early signs of recurrence. Furthermore, biomarkers enhance drug development and clinical trials by identifying suitable patients and accelerating the approval process. In this review paper, we described a variety of biomarkers applicable for cancer detection and diagnosis, such as imaging-based diagnosis (CT, SPECT, MRI, and PET), blood-based biomarkers (proteins, genes, mRNA, and peptides), cell imaging-based diagnosis (needle biopsy and CTC), tissue imaging-based diagnosis (IHC), and genetic-based biomarkers (RNAseq, scRNAseq, and spatial transcriptomics).

Cytoplasmic Androgen Receptor, CD24 Expression and Smoking Intensity to Urothelial Carcinoma of the Bladder Invasiveness: A Cross-Sectional Study

Purpose

To the best of our knowledge, Androgen receptor (AR) and cluster of differentiation 24 (CD24) expression in bladder urothelial carcinoma (UC) has not yet been reported in our population. The aim of this study was to evaluate the expression of both markers in UCB using immunohistochemistry.

Materials and Methods

Data from 60 patients with UCB were obtained between 2009 and 2018. The samples were divided into four groups based on their smoking history. Group 1 included non-smokers, group 2 smoked <20 cigarettes/day for 30 years, group 3 smoked for 31-40 years, and group 4 smoked for > 40 years. Each group then divided into Non muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC) subgroups. The smear was stained with hematoxylin and eosin (HE) - immunohistochemistry of CD24 and RA, followed by histoscore assessment.

Results

The male to female smoking rates was 1.8. Based on gender, in the NMIBC group there were 85.7% men and 14.3% were women while in MIBC 74.4% men and 25.6% women. The mean age of the NMIBC and MIBC groups was 56.3 years and 54.5 years, respectively. There was no significant relationship between smoking status in group 2 (OR 0.31, CI 95% CI, p=0,39), group 3 (OR 013, CI 95% CI, p=0,05), and group 4 (OR 0.23, CI 95% CI, p=0215) to the UCB invasiveness. A significant relationship was observed between cytoplasmic AR expression and UCB invasiveness (OR 0.14[0,04; 0.47], CI 95%, p=0.001). There was no significant relationship between RA in the nucleus and UCB invasion (OR 1.09[0,18; 6.48] CI 95%, p=1000). No significant relationship was observed between CD24 expression and UCB invasiveness (OR 0.81[0,27-2,45] CI 95%, p=0712).

Conclusion

Cytoplasmic AR expression is associated with UCB invasiveness. Smoking history and CD24 expression were not associated with UCB invasion.

Deciphering Common Traits of Breast and Ovarian Cancer Stem Cells and Possible Therapeutic Approaches

Breast cancer (BC) and ovarian cancer (OC) are among the most common and deadly cancers affecting women worldwide. Both are complex diseases with marked heterogeneity. Despite the induction of screening programs that increase the frequency of earlier diagnosis of BC, at a stage when the cancer is more likely to respond to therapy, which does not exist for OC, more than 50% of both cancers are diagnosed at an advanced stage. Initial therapy can put the cancer into remission. However, recurrences occur frequently in both BC and OC, which are highly cancer-subtype dependent. Therapy resistance is mainly attributed to a rare subpopulation of cells, named cancer stem cells (CSC) or tumor-initiating cells, as they are capable of self-renewal, tumor initiation, and regrowth of tumor bulk. In this review, we will discuss the distinctive markers and signaling pathways that characterize CSC, their interactions with the tumor microenvironment, and the strategies they employ to evade immune surveillance. Our focus will be on identifying the common features of breast cancer stem cells (BCSC) and ovarian cancer stem cells (OCSC) and suggesting potential therapeutic approaches.

Different prenatal supplementation strategies and its impacts on reproductive and nutrigenetics assessments of bulls in finishing phase

This study investigated the effect of different prenatal nutrition approaches in 126 pregnant Nellore cows on reproductive and nutrigenetic traits of the male offspring during the finishing phase. For that purpose, three nutritional treatments were used in these cows during pregnancy: PP - protein-energy supplementation in the final third, FP - protein-energy supplementation during the entire pregnancy, and NP - (control) only mineral supplementation. The male progeny (63 bulls; 665 ± 28 days of age) were evaluated for scrotal circumference, seminal traits, number of Sertoli cells and testicular area. We performed a genomic association (700 K SNPs) for scrotal circumference at this age. In addition, a functional enrichment was performed in search of significant metabolic pathways (P < 0.05) with inclusion of genes that are expressed in these genomic windows by the MetaCore software. With the exception of major sperm defects (P < 0.1), the other phenotypes showed no difference between prenatal treatments. We found genes and metabolic pathways (P < 0.05) that are associated with genomic windows (genetic variance explained >1%) in different treatments. These molecular findings indicate that there is genotype-environment interaction among the different prenatal treatments and that the FP treatment showed greater major sperm defects compared to the NP treatment.

SIRT1-Mediated Expression of CD24 and Epigenetic Suppression of Novel Tumor Suppressor miR-1185-1 Increases Colorectal Cancer Stemness

NAD-dependent deacetylase sirtuin-1 (SIRT1) is a class III histone deacetylase that positively regulates cancer-related pathways such as proliferation and stress resistance. SIRT1 has been shown to promote progression of colorectal cancer and is associated with cancer stemness, yet the precise mechanism between colorectal cancer stemness and SIRT1 remains to be further clarified. Here we report that SIRT1 signaling regulates colorectal cancer stemness by enhancing expression of CD24, a colorectal cancer stemness promoter. A novel miRNA, miR-1185-1, suppressed the expression of CD24 by targeting its 3'UTR (untranslated region) and could be inhibited by SIRT1 via histone deacetylation. Targeting SIRT1 by RNAi led to elevated H3 lysine 9 acetylation on the promoter region of miR-1185-1, which increased expression of miR-1185-1 and further repressed CD24 translation and colorectal cancer stemness. In a mouse xenograft model, overexpression of miR-1185-1 in colorectal cancer cells substantially reduced tumor growth. In addition, expression of miR-1185-1 was downregulated in human colorectal cancer tissues, whereas expression of CD24 was increased. In conclusion, this study not only demonstrates the essential roles of a SIRT1-miR-1185-1-CD24 axis in both colorectal cancer stemness properties and tumorigenesis but provides a potential therapeutic target for colorectal cancer treatment. SIGNIFICANCE: A novel tumor suppressor miR-1185-1 is involved in molecular regulation of CD24- and SIRT1-related cancer stemness networks, marking it a potential therapeutic target in colorectal cancer. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/23/5257/F1.large.jpg.

Reduced DAXX Expression Is Associated with Reduced CD24 Expression in Colorectal Cancer

The presence of an activating mutation of the Wnt/β-catenin signaling pathway is found in ~90% of colorectal cancer (CRC) cases. Death domain-associated protein (DAXX), a nuclear protein, interacts with β-catenin in CRC cells. We investigated DAXX expression in 106 matched sample pairs of CRC and adjacent normal tissue by Western blotting. This study evaluated DAXX expression and its clinical implications in CRC. The results revealed that DAXX expression was significantly lower in the patients with the positive serum carcinoembryonic antigen (CEA) screening results compared to the patients with negative CEA screening levels (p < 0.001). It has been reported that CD24 is a Wnt target in CRC cells. Here, we further revealed that DAXX expression was significantly correlated with CD24 expression (rho = 0.360, p < 0.001) in 106 patients. Consistent with this, in the CEA-positive subgroup, of which the carcinomas expressed DAXX at low levels, they were significantly correlated with CD24 expression (rho = 0.461, p < 0.005). Therefore, reduced DAXX expression is associated with reduced CD24 expression in CRC. Notably, in the Hct116 cells, DAXX knockdown using short-hairpin RNA against DAXX (shDAXX) not only caused significant cell proliferation, but also promoted metastasis. The DAXX-knockdown cells also demonstrated significantly decreased CD24 expression, however the intracellular localization of CD24 did not change. Thus, DAXX might be considered as a potential regulator of CD24 or β-catenin expression, which might be correlated with proliferative and metastatic potential of CRC.

Plasticity and Potency of Mammary Stem Cell Subsets During Mammary Gland Development

It is now widely believed that mammary epithelial cell plasticity, an important physiological process during the stages of mammary gland development, is exploited by the malignant cells for their successful disease progression. Normal mammary epithelial cells are heterogeneous and organized in hierarchical fashion, in which the mammary stem cells (MaSC) lie at the apex with regenerative capacity as well as plasticity. Despite the fact that the majority of studies supported the existence of multipotent MaSCs giving rise to both basal and luminal lineages, others proposed lineage restricted unipotent MaSCs. Consistent with the notion, the latest research has suggested that although normal MaSC subsets mainly stay in a quiescent state, they differ in their reconstituting ability, spatial localization, and molecular and epigenetic signatures in response to physiological stimuli within the respective microenvironment during the stages of mammary gland development. In this review, we will focus on current research on the biology of normal mammary stem cells with an emphasis on properties of cellular plasticity, self-renewal and quiescence, as well as the role of the microenvironment in regulating these processes. This will include a discussion of normal breast stem cell heterogeneity, stem cell markers, and lineage tracing studies.

Clinicopathological and Prognostic Value of Plasma CD24 Level in Hepatocellular Carcinoma

Purpose: CD24 is overexpressed in hepatocellular carcinoma (HCC) tumor tissues and in the highly metastatic HCC cell lines. However, plasma CD24 level in HCC patients and the correlation of plasma CD24 level with clinicopathological factors and prognosis of HCC patients still remain unclear. Materials and Methods: Enzyme-linked immunosorbent assay was used to detect plasma CD24 level in 86 HCC patients, 35 healthy subjects, 26 patients with liver cirrhosis and 23 patients with chronic hepatitis. The relationship between plasma CD24 level with clinicopathological characteristics in HCC patients was assessed using the Mann-Whitney U test. Patient survival between groups was evaluated by the Kaplan-Meier method and the log-rank test, prognostic factors being analyzed by the Cox regression model. Results: Our present study demonstrated that plasma CD24 level in HCC patients was significantly higher than that in the controls. CD24 was significantly associated with tumor differentiation, but was not correlated with other clinicopathologic parameters including gender, age, tumor size, tumor number, capsulation status, HBsAg status, tumor node metastasis stage, ALT, AFP, and GGT level. CD24 might be a prognostic predictor for overall survival and recurrence-free survival. Conclusions: Plasma CD24 level was significantly higher in HCC patients than that in the controls. Plasma CD24 level was associated with tumor differentiation. The HCC patients with high plasma CD24 level had unfavorable prognosis. CD24 might be a prognostic biomarker for HCC in the future.

Serum concentrations of soluble (s)L- and (s)P-selectins in women with ovarian cancer

Introduction

The aim of the study was to compare serum concentration of soluble L- and P-selectins in women with ovarian cancer (OC) and healthy controls, and to investigate sL- and sP-selectin levels with regard to clinical and pathological parameters. Correlation analysis was used to measure the following: sL- and sP-selectin concentration and Ca125; sP-selectin and platelet concentrations; and sL-selectin and serum leukocyte levels in women with OC.

Material and methods

The study included 29 patients with OC and 23 healthy controls. Serum concentrations of sL- and sP-selectins were measured in all subjects. Routine diagnostic tests: CBC and USG (both groups) and Ca125 (study group) were performed.

Results

Significantly higher serum concentrations of sL- and sP-selectins were found in the study group as compared to controls. Lower levels of serum sL-selectin were observed in women with poorly-differentiated OC (G3) and advanced stages of the disease (FIGO III, IV), but the results were statistically insignificant. No statistically significant relationship was detected between sP-selectin serum concentration in women with OC and tumour differentiation, histological type, and stage of the disease. No significant correlation was found between sL- and sP-selectins and Ca125 levels. A weak correlation was found between serum concentration of sP-selectin in women with OC and platelet count. No statistically significant correlation was observed between sL-selectin concentration and serum leukocyte levels in women with OC.

Conclusions

The analysis of sL- and sP-selectin concentrations may be a useful tool in the diagnosis of OC. The levels of sL-selectin decrease with disease progression.

Fine-needle aspiration of skin metastasis in ovarian cancer-report of two cases and review of the literature

Ovarian cancer is known to be the first cause of death of gynecological malignancy in Europe and United States. Skin metastases consist of an unusual event during the course of ovarian carcinoma and occur in 2-3.5% of the patients. We report two interested cases of patient with skin metastases, due to ovarian carcinoma, diagnosed by fine-needle aspiration (FNA). The clinical information, cytologic findings and immunocytochemical profile are described and further discussed, according to the relevant bibliographic data. The combination of FNA and thin layer cytology contribute to the accurate clarification of metastatic tumors with a known or unknown origin. It known that skin metastasis tend occurs in most ovarian carcinomas at a late stage course of the disease and it is usually associated with poor prognosis, in some cases the survival can be prolonged with appropriate therapy. So, an accurate cyto-immunodiagnosis is crucial for the best management of these patients.

The biological complexity of colorectal cancer: insights into biomarkers for early detection and personalized care

Colorectal cancer has been ranked the third and second most prevalent of all cancers in men and women, respectively, and it represents the fourth most common cause of cancer deaths. In 2012, there were 1.4 million estimated cases of colorectal cancer worldwide, and 700,000 estimated deaths, which implies significant impact on public health, especially in economically-developed countries. In recent years, there has been an increase in the number of tumors, although this has been accompanied by decreased mortality, due to more appropriate and available information, earlier diagnosis, and improvements in treatment. Colorectal cancers are characterized by great genotypic and phenotypic heterogeneity, including tumor microenvironment and interactions between healthy and cancer cells. All of these traits confer a unique peculiarity to each tumor, which can thus be considered as an individual disease. Well conducted molecular and clinical characterization of each colorectal cancer is essential with a view to the implementation of precision oncology, and thus personalized care. This last aims at standardization of therapeutic plans chosen according to the genetic background of each specific neoplasm, to increase overall survival and reduce treatment side effects. Thus, prognostic and predictive molecular biomarkers assume a critical role in the characterization of colorectal cancer and in the determination of the most appropriate therapy.

Identification of High-Risk Aberrant Crypt Foci and Mucin-Depleted Foci in the Human Colon With Study of Colon Cancer Stem Cell Markers

BACKGROUND

During colonoscopic screening, only macroscopic lesions will be identified, and these are usually the result of multiple genetic abnormalities. Magnification endoscopic detection of aberrant crypt foci (ACF), long before they acquire complex genetic abnormalities, is promising. However, the features of high-risk ACF-like lesions need to be identified.

MATERIALS AND METHODS

In the present cross-sectional study, grossly visible normal mucosal flaps were shaved from 152 colectomies, including 96 colorectal cancer (CRC) cases and 56 controls (22 control specimens with disease with malignant potential and 34 without malignant potential). Methylene and Alcian blue stains were performed directly on the unfixed mucosal flaps to identify ACF and mucin-depleted foci (MDF). Detailed topographic analyses, with immunohistochemical staining for β-catenin and cancer stem cell (CSC) markers (CD44, CD24, and CD166) were performed.

RESULTS

ACF, MDF, and β-catenin-accumulated crypts were detected more in specimens with adjacent CRC. The left colon had ACF with a larger diameter and greater crypt multiplicity, density, and gyriform pit pattern and were considered the high-risk ACF group. MDF, more commonly associated with dysplasia, is also a marker of possible carcinogenesis. The CD44 CSC marker was significantly upregulated in ACF specimens compared with normal controls. Our 3-tier ACF-only pit pattern classification system showed better linearity with mucosal dysplasia than did the 6-tier Kudo classification.

CONCLUSION

High-risk ACF, when detected during chromoendoscopic screening, should be followed up. CSCs might play an important role in pathogenesis. Larger studies and genotypic risk stratification for definite identification of high-risk ACF are needed.

Terpinen-4-ol: A Novel and Promising Therapeutic Agent for Human Gastrointestinal Cancers

Background

Terpinen-4-ol, a naturally occurring monoterpene is the main bioactive component of tea-tree oil and has been shown to have many biological activities.

Aim

To study the antitumor effects of terpinen-4-ol and its mechanism of action in prostate and GI malignancies, alone and in combination with chemotherapeutic and biological agents.

Methods

Terpinen-4-ol was administrated alone or combined with standard chemotherapy (Oxaliplatin, Fluorouracil, Gemcitabine, Tarceva) and biological agent (Cetuximab). It was also combined with humanized anti-CD24 mAbs (was developed by us). Killing effects were measured qualitatively by light microscopy and quantitatively using the MTT and FACS analysis, following treatment of colorectal, pancreatic, gastric and prostate cancer cells. Terpinen-4-ol effect on tumor development was evaluated in xenograft model.

Results

Terpinen-4-ol induces a significant growth inhibition of colorectal, pancreatic, prostate and gastric cancer cells in a dose-dependent manner (10–90% in 0.005–0.1%). Terpinen-4-ol and various anti-cancer agents (0.2μM oxaliplatin and 0.5μM fluorouracil) demonstrated a synergistic inhibitory effect (83% and 91%, respectively) on cancer cell proliferation. In KRAS mutated colorectal cancer cells, which are resistant to anti-EGFR therapy, combining of terpinen-4-ol with cetuximab (1 μM) resulted in impressive efficacy of 80–90% growth inhibition. Sub-toxic concentrations of terpinen-4-ol potentiate anti-CD24 mAb (150μg/ml)-induced growth inhibition (90%). Considerable reduction in tumor volume was seen following terpinen-4-ol (0.2%) treatment alone and with cetuximab (10mg/kg) (40% and 63%, respectively) as compare to the control group.

Conclusion

Terpinen-4-ol significantly enhances the effect of several chemotherapeutic and biological agents. The possible molecular mechanism for its activity involves induction of cell-death rendering this compound as a potential anti-cancer drug alone and in combination in the treatment of numerous malignancies. Terpinen-4-ol restores the activity of cetuximab in cancers with mutated KRAS.

CD24 cell surface expression in Mvt1 mammary cancer cells serves as a biomarker for sensitivity to anti-IGF1R therapy

Background

The pro-tumorigenic effects of the insulin-like growth factor receptor (IGF1R) are well described. IGF1R promotes cancer cell survival and proliferation and prevents apoptosis, and, additionally it was shown that IGF1R levels are significantly elevated in most common human malignancies including breast cancer. However, results from phase 3 clinical trials in unselected patients demonstrated lack of efficacy for anti-IGF1R therapy. These findings suggest that predictive biomarkers are greatly warranted in order to identify patients that will benefit from anti-IGF1R therapeutic strategies.

Methods

Using the delivery of shRNA vectors into the Mvt1 cell line, we tested the role of the IGF1R in the development of mammary tumors. Based on CD24 cell surface expression, control and IGF1R-knockdown (IGF1R-KD) cells were FACS sorted into CD24⁻ and CD24⁺ subsets and further characterized in vitro. The tumorigenic capacity of each was determined following orthotopic inoculation into the mammary fat pad of female mice. Tumor cells were FACS characterized upon sacrifice to determine IGF1R effect on the plasticity of this cell’s phenotype. Metastatic capacity of the cells was assessed using the tail vein assay.

Results

In this study we demonstrate that downregulation of the IGF1R specifically in cancer cells expressing CD24 on the cell surface membrane affect both their morphology (from mesenchymal-like into epithelial-like morphology) and phenotype in vitro. Moreover, we demonstrate that IGF1R-KD abolished both CD24⁺ cells capacity to form mammary tumors and lung metastatic lesions. We found in both cells and tumors a marked upregulation in CTFG and a significant reduction of SLP1 expression in the CD24⁺/IGF1R-KD; tumor-suppressor and tumor-promoting genes respectively.

Moreover, we demonstrate here that the IGF1R is essential for the maintenance of stem/progenitor-like cancer cells and we further demonstrate that IGF1R-KD induces in vivo differentiation of the CD24⁺ cells toward the CD24^- phenotype. This further supports the antitumorigenic effects of IGF1R-KD, as we recently published that these differentiated cells demonstrate significantly lower tumorigenic capacity compared with their CD24⁺ counterparts.

Conclusions

Taken together these findings suggest that CD24 cell surface expression may serve as a valuable biomarker in order to identify mammary tumors that will positively respond to targeted IGF1R therapies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0711-7) contains supplementary material, which is available to authorized users.

CD24 Is Not Required for Tumor Initiation and Growth in Murine Breast and Prostate Cancer Models

CD24 is a small, heavily glycosylated, GPI-linked membrane protein, whose expression has been associated with the tumorigenesis and progression of several types of cancer. Here, we studied the expression of CD24 in tumors of MMTV-PyMT, Apc^1572/T+ and TRAMP genetic mouse models that spontaneously develop mammary or prostate carcinoma, respectively. We found that CD24 is expressed during tumor development in all three models. In MMTV-PyMT and Apc^1572T/+ breast tumors, CD24 was strongly but heterogeneously expressed during early tumorigenesis, but decreased in more advanced stages, and accordingly was increased in poorly differentiated lesions compared with well differentiated lesions. In prostate tumors developing in TRAMP mice, CD24 expression was strong within hyperplastic lesions in comparison with non-hyperplastic regions, and heterogeneous CD24 expression was maintained in advanced prostate carcinomas. To investigate whether CD24 plays a functional role in tumorigenesis in these models, we crossed CD24 deficient mice with MMTV-PyMT, Apc^1572T/+ and TRAMP mice, and assessed the influence of CD24 deficiency on tumor onset and tumor burden. We found that mice negative or positive for CD24 did not significantly differ in terms of tumor initiation and burden in the genetic tumor models tested, with the exception of Apc^1572T/+ mice, in which lack of CD24 reduced the mammary tumor burden slightly but significantly. Together, our data suggest that while CD24 is distinctively expressed during the early development of murine mammary and prostate tumors, it is not essential for the formation of tumors developing in MMTV-PyMT, Apc^1572T/+ and TRAMP mice.

Delayed Wound Healing in Heat Stable Antigen (HSA/CD24)-Deficient Mice

Background

Healthy individuals rarely have problems with wound healing. Most skin lesions heal rapidly and efficiently within one to two weeks. However, many medical and surgical complications can be attributed to deficiencies in wound repair. Open wounds have lost the barrier that protects tissues from bacterial invasion and allows the escape of vital fluids. Without expeditious healing, infections become more frequent. The CD24 gene encodes a heavily-glycosylated cell surface protein anchored to the membrane by phosphatidylinositol. CD24 plays an important role in the adaptive immune response and controls an important genetic checkpoint for homeostasis and autoimmune diseases in both mice and humans. We have previously shown that overexpression of CD24 results in increased proliferation and migration rates.

Aim

To examine the role of CD24 in the wound healing process.

Methods

An excisional model of wound healing was used and delayed wound healing was studied in genetically modified heat stable antigen (HSA/CD24)-deficient mice (HSA^-/-) compared to wild-type (WT) mice.

Results

Large full-thickness skin wounds, excised on the back of mice, exhibited a significant delay in the formation of granulation tissue, and in wound closure when compared to their WTHSA^+/+ littermates. Wounds were histologically analyzed and scored, based on the degree of cellular invasion, granulation tissue formation, vascularity, and re-epithelialization. Additionally, in stitched wounds, the HSA^-/- mice failed to maintain their stitches; they did not hold and fell already 24 hours, revealing erythematous wound fields. Re-expression of HSA, delivered by lentivirus, restored the normal healing phenotype, within 24 hours post-injury, and even improved the healing in WT, and in BalbC mice.

Conclusions

Delayed wound-healing in the absence of HSA/CD24 suggests that CD24 plays an important role in this process. Increased expression of CD24, even in the normal state, may be used to enhance wound repair.

Association of CD24 and the adenomatous polyposis coli gene polymorphisms with oral lichen planus

OBJECTIVE

CD24 and the adenomatous polyposis coli (APC) gene polymorphisms are known to predispose to malignant disease. We aimed to investigate their association with risk and susceptibility of oral lichen planus (OLP) in an Israeli Jewish population.

STUDY DESIGN

The study included 54 patients, of which 41 were females (75.9%) and 13 males (24.1%); of the 533 controls, 224 were females (42.0%) and 309 males (57.9%). Genotyping was performed. Two APC (I1307 K, E1317 Q) and four CD24 variants--C170 T (rs52812045), TG1527 del (rs3838646), A1626 G (rs1058881), and A1056 G (rs1058818)--were assessed. Frequencies were analyzed using the Chi-square test. Two-sided P < .05 values were considered significant. Odds ratios and 95% confidence intervals were obtained by logistic regression analyses.

RESULTS

CD24 A1056 G carriers have a significantly lower risk of OLP compared with individuals with the wild-type variant (P = .001). A significantly lower risk was found for heterozygote (P = .008) and homozygote carriers (P = .002). Homozygote CD24 A1626 G carriers had a significant higher risk for OLP compared with nonhomozygote carriers (P = .040). CD24 C170 T, TG1527 del, and APC polymorphisms did not show significant associations with OLP risk.

CONCLUSIONS

CD24 A1626 G is more frequent in OLP patients, contributes to disease risk, and could play a role in OLP susceptibility. A significant association between CD24 A1056 G and a lower OLP incidence was found, suggesting that it may confer protection against OLP risk and progression.

CD24(+) cells fuel rapid tumor growth and display high metastatic capacity

Introduction

Breast tumors are comprised of distinct cancer cell populations which differ in their tumorigenic and metastatic capacity. Characterization of cell surface markers enables investigators to distinguish between cancer stem cells and their counterparts. CD24 is a well-known cell surface marker for mammary epithelial cells isolation, recently it was suggested as a potential prognostic marker in a wide variety of malignancies. Here, we demonstrate that CD24⁺ cells create intra-tumor heterogeneity, and display highly metastatic properties.

Methods

The mammary carcinoma Mvt1 cells were sorted into CD24⁻ and CD24⁺ cells. Both subsets were morphologically and phenotypically characterized, and tumorigenic capacity was assessed via orthotopic inoculation of each subset into the mammary fat pad of wild-type and MKR mice. The metastatic capacity of each subset was determined with the tail vein metastasis assay. The role of CD24 in tumorigenesis was further examined with shRNA technology. GFP-labeled cells were monitored in vivo for differentiation. The genetic profile of each subset was analyzed using RNA sequencing.

Results

CD24⁺ cells displayed a more spindle-like cytoplasm. The cells formed mammospheres in high efficiency and CD24⁺ tumors displayed rapid growth in both WT and MKR mice, and were more metastatic than CD24- cells. Interestingly, CD24-KD in CD24+ cells had no effect both in vitro and in vivo on the various parameters studied. Moreover, CD24⁺ cells gave rise in vivo to the CD24⁻ that comprised the bulk of the tumor. RNA-seq analysis revealed enrichment of genes and pathways of the extracellular matrix in the CD24⁺ cells.

Conclusion

CD24⁺ cells account for heterogeneity in mammary tumors. CD24 expression at early stages of the cancer process is an indication of a highly invasive tumor. However, CD24 is not a suitable therapeutic target; instead we suggest here new potential targets accounting for early differentiated cancer cells tumorigenic capacity.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0589-9) contains supplementary material, which is available to authorized users.

Highly specific role of the insulin receptor in breast cancer progression

Accumulating evidence from clinical trials indicates that specific targeting of the IGF1 receptor (IGF1R) is not efficient as an anti-breast cancer treatment. One possible reason is that the mitogenic signals from the insulin receptor (IR) can be processed independently or as compensation to inhibition of the IGF1R. In this study, we highlight the role of the IR in mediating breast tumor progression in both WT mice and a hyperinsulinemic MKR mouse model by induction of Ir (Insr) or Igf1r knockdown (KD) in the mammary carcinoma Mvt-1 cell line. By using the specific IR antagonist-S961, we demonstrated that Igf1r-KD induces elevated responses by the IR to IGF1. On the other hand, Ir-KD cells generated significantly smaller tumors in the mammary fat pads of both WT and MKR mice, as opposed to control cells, whereas the Igf1r-KD cells did not. The tumorigenic effects of insulin on the Mvt-1 cells were also demonstrated using microarray analysis, which indicates alteration of genes and signaling pathways involved in proliferation, the cell cycle, and apoptosis following insulin stimulation. In addition, the correlation between IR and the potential prognostic marker for aggressive breast cancer, CD24, was examined in the Ir-KD cells. Fluorescence-activated cell sorting (FACS) analysis revealed more than 60% reduction in CD24 expression in the Ir-KD cells when compared with the control cells. Our results also indicate that CD24-expressing cells can restore, at least in part, the tumorigenic capacity of Ir-KD cells. Taken together, our results highlight the mitogenic role of the IR in mammary tumor progression with a direct link to CD24 expression.

Nitrogen permease regulator-like 2 enhances sensitivity to oxaliplatin in colon cancer cells

Colorectal cancer (CRC) is the third most common cancer worldwide. Chemotherapeutic compounds used for the treatment of CRC include oxaliplatin (L-OHP). While L-OHP improves CRC survival, certain patients are resistant. The nitrogen permease regulator like-2 (NPRL2) gene is a candidate tumor suppressor gene that resides in a 120-kb homozygous deletion region on chromosome 3p21.3. In the present study, it was demonstrated that NPRL2 overexpression increases the sensitivity of HCT116 cells to L-OHP. The IC50 of L-OHP was decreased in cells transduced with NPRL2 compared with negative control (NC) cells and the effect of NPRL2 on L-OHP sensitivity was time dependent. Following NPRL2 transduction in HCT116 cells, the cell cycle was arrested in the G1 phase and a partial decrease in the S phase population was observed. Flow cytometric analysis revealed that NPRL2 transduction and L-OHP treatment increased apoptosis compared with NC cells. The mechanism through which NPRL2 overexpression enhances L-OHP sensitivity involves downregulation of the functions of the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin network. Furthermore, L-OHP upregulated caspase-3 and caspase-9 to promote apoptosis in NPRL2-overexpressing cells compared with cells that were transduced with NPRL2 or treated with L-OHP and NC cells (P<0.01). NPRL2 overexpression led to the downregulation of CD24, which could significantly reduce tumor invasiveness and decrease the metastatic capacity of HCT116 cells. These mechanisms are likely active in other types of cancer and may be exploited for the development of novel cancer therapies.

CD24 mediates gastric carcinogenesis and promotes gastric cancer progression via STAT3 activation

The development of gastric cancer (GC) is a complex multistep process, including numerous genetic and epigenetic changes. CD24 is associated with enhanced invasiveness of GC and a poor prognosis. However, the mechanism by which CD24 induces GC progression remains poorly characterized. Here, we found that the expression of CD24 gradually increased in samples of normal gastric mucosa, non-atrophic chronic gastritis, chronic atrophic gastritis (CAG), CAG with intestinal metaplasia, dysplasia and GC. Moreover, the knockdown of CD24 induced significant levels of apoptosis in GC cells via the mitochondrial apoptotic pathway. CD24 may also promote cellular invasion and regulate the expression of E-cadherin, fibronectin and vitamin D receptor in GC cells. The activation of signal transducer and activator of transcription 3 (STAT3) may mediate CD24-induced GC survival and invasion in vitro. Furthermore, CD24-induced GC progression and STAT3 activation could also be detected in vivo and in clinical GC tissues samples. Taken together, our results indicate that CD24 mediates gastric carcinogenesis and may promote GC progression by suppressing apoptosis and promoting invasion, with the activation of STAT3 playing a critical role.

Comparative analysis of the expression of surface markers on fibroblasts and fibroblast-like cells isolated from different human tissues

Expression of 20 surface markers was analyzed in cultures of mesenchymal stromal cells of the umbilical cord, fibroblasts from adult and fetal human skin, and fibroblast-like cells of fetal liver was analyzed by fl ow cytometry. The studied cultures did not express hemopoietic cells markers, but were positive for CD73, CD90, and CD105 markers recommended by the International Society of Cell Therapy for the identification of the multipotent mesenchymal stromal cells. Fetal liver fibroblast-like cells were positive for CD54; this marker was absent in skin fibroblast cultures, but was expressed by umbilical cord mesenchymal stromal cells. Further study of these cells revealed a minor subpopulation of cells co-expressing CD24 and CD90 or CD24 and CD54. We hypothesized that these cells probably participate in epithelial mesenchymal transition.

Cancer stem cells in head and neck squamous cell carcinoma: a review

Research indicates that a small population of cancer cells is highly tumorigenic, endowed with the capacity for self-renewal, and has the ability to differentiate into cells that constitute the bulk of tumors. These cells are considered the "drivers" of the tumorigenic process in some tumor types, and have been named cancer stem cells (CSC). Epithelial-mesenchymal transition (EMT) appears to be involved in the process leading to the acquisition of stemness by epithelial tumor cells. Through this process, cells acquire an invasive phenotype that may contribute to tumor recurrence and metastasis. CSC have been identified in human head and neck squamous cell carcinomas (HNSCC) using markers such as CD133 and CD44 expression, and aldehyde dehydrogenase (ALDH) activity. Head and neck cancer stem cells reside primarily in perivascular niches in the invasive fronts where endothelial-cell initiated events contribute to their survival and function. Clinically, CSC enrichment has been shown to be enhanced in recurrent disease, treatment failure and metastasis. CSC represent a novel target of study given their slow growth and innate mechanisms conferring treatment resistance. Further understanding of their unique phenotype may reveal potential molecular targets to improve therapeutic and survival outcomes in patients with HNSCC. Here, we discuss the state-of-the-knowledge on the pathobiology of cancer stem cells, with a focus on the impact of these cells on head and neck tumor progression, metastasis and recurrence due to treatment failure.

CD44/CD24 as potential prognostic markers in node-positive invasive ductal breast cancer patients treated with adjuvant chemotherapy

The hypothesis on cancer stem cells assumes the existence of small subpopulation of cells that possess the ability to undergo self-renewal and can give rise to the diversity of differentiated cells that form the tumour. It has been accepted that CD44(+)/CD24(-/low) phenotype is one of the features characterizing breast cancer stem cells. The aim of our study was to assess (1) prognostic significance of CD44/CD24 expression as well as (2) a relation between the above-mentioned phenotype and breast cancer subtypes [based on estrogen (ER), progesterone receptors, human epidermal growth factor receptor 2 and Ki67 status] and expression of selected markers such as fascin, laminin-5 gamma-2 chain, cytokeratin (CK) 5/6 and 8/18, epidermal growth factor receptor (EGFR), smooth muscle actin, P-cadherin and lymphocytic infiltration in invasive ductal breast cancer patients (T ≥ 1, N ≥ 1, M0), who underwent mastectomy followed by chemotherapy (with taxanes and/or anthracyclines) or/and hormonotherapy. We noted that most cancers with CD44-/CD24- and CD44-/CD24+ phenotype were ER positive. The majority of CD44-/CD24-, CD44-/CD24+ and CD44+/CD24- tumours were characterized by CK5/6 and EGFR negativity. In univariate analysis we demonstrated that patients with pN1/pN2 and with CD44 +/CD24- carcinomas had significantly lower risk of progression or cancer-related death than those with pN3 or tumours characterised by other CD44/CD24 expression patterns. We also found 100 % DFS in 12 patients with CD44+/CD24-/CK5/6+/ER- phenotype. Other analysed parameters were insignificant. We conclude that tumours with immunophenotypes: CD44+/CD24- and CD44+/CD24-/CK5/6+/ER- might be more sensitive for chemotherapy based on taxanes and/or anthracyclines.

CD24 and CD44 in salivary gland pleomorphic adenoma and in human salivary gland morphogenesis: differential markers of glandular structure or stem cell indicators?

AIMS

Salivary gland neoplasms originate from salivary gland compartments, to which they are histologically related. Pleomorphic adenoma (PA) is a benign salivary gland neoplasm that comprises epithelial and myoepithelial cells and a complex stroma, whose structure, architecture and origin (from intercalated ducts) suggest stem cell participation. We compared the expression of CD24 and CD44 in PA and in developing human salivary glands to investigate whether these markers can be considered as cancer stem cell markers.

METHODS AND RESULTS

One hundred and one cases of PA and salivary gland specimens from 20 human fetuses were examined by immunohistochemistry and real-time reverse transcription polymerase chain reaction (RT-PCR). All PAs were positive for CD24 and CD44 by immunohistochemistry: neoplastic luminal structures were positive for CD24; modified myoepithelial cells were positive for CD44. In fetal salivary glands, these markers were restricted to the intercalated duct region. Real-time RT-PCR assays detected increased expression of CD44, but not CD24, in PA specimens in comparison with normal salivary gland controls.

CONCLUSIONS

PA and stem cells share the expression of CD24 and CD44; their value as markers of neoplastic cell multipotency and the implications of their expression for tumour behaviour are yet to be determined.

Colorectal cancer biomarkers and the potential role of cancer stem cells

Over 50% of patients with colorectal cancer (CRC) will progress and/or develop metastases. Biomarkers capable of predicting progression, risk stratification and therapeutic benefit are needed. Cancer stem cells are thought to be responsible for tumor initiation, dissemination and treatment failure. Therefore, we hypothesized that CRC stem cell markers (CRCSC) can identify a group of patients whom are at increased risk for recurrence or progression of disease. If proven correct, these CRCSC biomarkers may herald a paradigm shift in the treatment of this deadly disease. This manuscript reviews current CRC evidence based screening modalities, patient stratification, and summarizes the current state of biomarkers and discusses the novel concept of putative CRCSC's as prognostic biomarkers.

Increased expression of CD24 in nonmelanoma skin cancer

BACKGROUND

Skin cancer detection is based on the macroscopic and microscopic appearance of the lesions and the experience of the surgeon. The final diagnosis is done by pathological analysis, based on established criteria. Currently, there is no serum marker that can be used for the diagnosis of skin cancer. CD24, a mucin-like glycoprotein, is overexpressed in a variety of cancers including skin malignancies.

OBJECTIVE

Evaluate the potential utility of CD24 expression in peripheral blood leukocytes (PBLs) for the detection of nonmelanoma skin cancers (NMSC).

METHODS

Twenty-nine consented individuals attending Tel Aviv Sourasky Medical Center for excision of suspected skin lesions, and 21 age- and gender-matched subjects were prospectively recruited. The resected lesions were examined by an expert dermatopathologist. PBLs were isolated from blood samples and protein extracts were subjected to sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. The study was double blinded.

RESULTS

CD24 expression in PBLs distinguishes between NMSC and healthy subjects, with high sensitivity (81%) and specificity (67%) for basal cell carcinoma, and 100% and 71%, respectively, for squamous cell carcinoma.

CONCLUSION

The CD24 test can successfully distinguish NMSC from healthy subjects. CD24 may serve as a new potential and promising diagnostic biomarker for the detection and surveillance of NMSC.

Cancer stem cells in head and neck cancer

Cancer stem cells (CSCs), also called “cells that start the tumor,” represent in themselves one of the most topical and controversial issues in the field of cancer research. Tumor stem cells are able to self-propagate in vitro (self-renewal), giving rise both to other tumor stem cells and most advanced cells in the line of differentiation (asymmetric division). A final characteristic is tumorigenicity, a fundamental property, which outlines the tumor stem cell as the only cell able to initiate the formation of a tumor when implanted in immune-deficient mice. The hypothesis of a hierarchical organization of tumor cells dates back more than 40 years, but only in 1997, thanks to the work of John Dick and Dominique Bonnet, was there the formal proof of such an organization in acute myeloid leukemia. Following this, many other research groups were able to isolate CSCs, by appropriate selection markers, in various malignancies, such as breast, brain, colon, pancreas, and liver cancers and in melanoma. To date, however, it is not possible to isolate stem cells from all types of neoplasia, particularly in solid tumors. From a therapeutic point of view, the concept of tumor stem cells implies a complete revision of conventional antineoplastic treatment. Conventional cytotoxic agents are designed to target actively proliferating cells. In the majority of cases, this is not sufficient to eliminate the CSCs, which thanks to their reduced proliferative activity and/or the presence of proteins capable of extruding chemotherapeutics from the cell are not targeted. Therefore, the theory of cancer stem cells can pose new paradigms in terms of cancer treatment. Potential approaches, even in the very early experimental stages, relate to the selective inhibition of pathways connected with self-renewal, or more specifically based on the presence of specific surface markers for selective cytotoxic agent vehicles. Finally, some research groups are trying to induce these cells to differentiate, thus making them easier to remove. For all these reasons, we have collected existing literature on head and neck cancer stem cells that correlate the biological characteristics of this subpopulation of cancer cells with the clinical behavior of tumors.

Increased expression of CD24 is associated with tumor progression and prognosis in patients suffering osteosarcoma

OBJECTIVE

As a small heavily glycosylated mucin-like glycosyl-phosphatidylinositol-anchored cell surface protein, CD24 plays an important role in carcinogenesis of various human malignancies. However, its involvement in osteosarcoma is still unclear. The aim of this study was to investigate the expression pattern and the clinical significance of CD24 in human osteosarcoma.

METHODS

CD24 mRNA and protein expression levels were, respectively, detected by RT-PCR and Western blot assays using 30 pairs of osteosarcoma and noncancerous bone tissues. Then, immunohistochemistry was performed to analyze the association of CD24 expression in 166 osteosarcoma tissues with clinicopathological factors or survival of patients.

RESULTS

CD24 expression at mRNA and protein levels were both significantly higher in osteosarcoma tissues than those in corresponding noncancerous bone tissues (both P < 0.001). In addition, CD24 protein was positively expressed in 129 of 166 (77.7 %) osteosarcoma specimens with a cytoplasmic and membraneous staining, and also increased in the osteosarcoma specimens with advanced clinical stage (P = 0.01) and positive distant metastasis (P = 0.005). The univariate and multivariate analyses showed that osteosarcoma patients with high CD24 expression had poorer overall and disease-free survival, and high CD24 expression was an independent prognostic factor for both overall and disease-free survival.

CONCLUSION

The aforementioned findings offer convincing evidence for the first time that the increased expression of CD24 is correlated with tumor aggressiveness and tumor metastasis of osteosarcoma, and this molecule is an independent prognostic marker for osteosarcoma patients.

CD24 is expressed in gastric parietal cells and regulates apoptosis and the response to Helicobacter felis infection in the murine stomach

CD24 is expressed in the putative stem cells within several tissues and is overexpressed in gastric and colonic adenocarcinomas. Perturbed CD24 expression may therefore alter the response of gastrointestinal epithelia to damage-inducing stimuli that induce cancer. We have investigated the effects of CD24 deletion on gastric responses to Helicobacter felis infection and γ-irradiation using CD24-null mice. Gastric CD24 expression was determined by immunohistochemistry in C57BL/6 mice. Female CD24-null and C57BL/6 mice were infected with H. felis for 6 wk, and inflammation, proliferation, apoptosis, and parietal cell numbers were assessed in gastric tissue sections. Apoptosis and proliferation were analyzed on a cell-positional basis in stomach, small intestine, and colon of CD24-null and C57BL/6 mice following γ-irradiation. Apoptosis was also assessed in HT29 cells following CD24 siRNA transfection. Of CD24-positive cells in the gastric corpus, 98% were H(+)-K(+)-ATPase-expressing parietal cells. CD24-null mice showed more prominent gastric H. felis colonization than C57BL/6 mice but displayed a marked reduction in corpus inflammation, reduced Ki67 labeling, and less gastric atrophy 6 wk following infection. Corpus apoptosis was elevated in CD24-null mice, but this did not increase further with H. felis infection as observed in C57BL/6 mice. More apoptotic cells were found following γ-irradiation in the stomach, small intestine, and colon of CD24-null mice and following CD24 knockdown in vitro. In conclusion, CD24 is expressed in gastric parietal cells, where it modulates gastric responses to H. felis and γ-radiation. CD24 also regulates susceptibility to apoptosis in the distal murine gastrointestinal tract.

CD24 expression is important in male urothelial tumorigenesis and metastasis in mice and is androgen regulated

Overexpression of CD24, a glycosyl phosphatidylinositol-linked sialoglycoprotein, is associated with poor outcome in urothelial carcinoma and contributes to experimental tumor growth and metastasis. However, the requirement for CD24 (Cd24a in mice) in tumorigenesis and spontaneous metastasis from the orthotopic site remains uncharacterized. Using N-butyl-N-(4-hydroxybutyl) nitrosamine induction of invasive and metastatic bladder cancer, we show that Cd24a-deficient male mice developed fewer bladder tumors than C57BL/6 control male mice. Evaluating only mice with evidence of primary tumors, we observed that Cd24a-deficient male mice also had fewer metastases than wild-type counterparts. In parallel observations, stratification of patients based on CD24 immunohistochemical expression in their tumors revealed that high levels of CD24 are associated with poor prognosis in males. In female patients and mice the above observations were not present. Given the significant role of CD24 in males, we sought to assess the relationship between androgen and CD24 regulation. We discovered that androgen receptor knockdown in UM-UC-3 and TCCSUP human urothelial carcinoma cell lines resulted in suppression of CD24 expression and cell proliferation. Androgen treatment also led to increased CD24 promoter activity, dependent on the presence of androgen receptor. In vivo, androgen deprivation resulted in reduced growth and CD24 expression of UM-UC-3 xenografts, and the latter was rescued by exogenous CD24 overexpression. These findings demonstrate an important role for CD24 in urothelial tumorigenesis and metastasis in male mice and indicate that CD24 is androgen regulated, providing the foundation for urothelial bladder cancer therapy with antiandrogens.

Cancer-initiating enriched cell lines from human glioblastoma: preparing for drug discovery assays

Glioblastoma multiforme (GBM) is the most lethal type of brain tumour in the adult humans. The cancer-initiating cell (CIC) hypothesis supports the notion that failures in current approaches to GBM treatment might be attributed to the survival of the CIC subpopulation. Recent evidence shows the idea that using CIC-enriched cell lines derived from human GBM as new targets for drug discovery programs, may improve the chance of successfully translating the basic research findings into clinical trials. Although this approach appears promising, many important biological and technical issues (characterization of functional CIC markers, inter- and intra-tumoral CIC heterogeneity, and isolation and maintenance inconsistency) need to be resolved.

A Pilot Study Assessing the Potential Role of non-CD133 Colorectal Cancer Stem Cells as Biomarkers

Introduction: Over 50% of patients with colorectal cancer (CRC) will progress and/or develop metastases. Biomarkers capable of predicting progression, risk stratification and therapeutic benefit are needed. Cancer stem cells are thought to be responsible for tumor initiation, dissemination and treatment failure. Therefore, we hypothesized that CRC cancer stem cell markers (CRCSC) will identify a group of patients at high risk for progression.

Methods: Paraffin-embedded tissue cores of normal (n=8), and histopathologically well-defined primary (n= 30) and metastatic (n=10) CRC were arrayed in duplicate on tissue microarrays (TMAs). Expression profiles of non-CD133 CRCSC (CD29, CD44, ALDH1A1, ALDH1B1, EpCam, and CD166) were detected by immunohistochemistry and the association with clinicopathological data and patient outcomes was determined using standard statistical methodology. An independent pathologist, blinded to the clinical data scored the samples. Scoring included percent positive cells (0 to 4, 0 = <10%, 1 = 10 - 24%, 2 = 25 - 49%, 3 = 50 - 74%, 4 = 75 - 100%), and the intensity of positively stained cells (0 to 4; 0 = no staining, 1 = diminutive intensity, 2 = low intensity, 3 = intermediate intensity, 4 = high intensity). The pathologic score represents the sum of these two values, reported in this paper as a combined IHC staining score (CSS).

Results: Of 30 patients 7 were AJCC stage IIA, 10 stage IIIB, 7 stage IIIC and 6 stage IV. Median follow-up was 113 months. DFI was 17 months. Median overall survival (OS) was not reached. Stage-specific OS was: II - not reached; III - not reached; IV - 11 months. In a univariate analysis, poor OS was associated with loss of CD29 expression; median OS, 32 months vs. not reached for CSS 3-7 vs. >7.5, respectively; p=0.052 comparing entire curves, after adjustment. In a Cox model analysis, loss of CD29 exhibited a trend toward association with survival (p=0.098) after adjusting for the effect of stage (p=0.0076). Greater expression of ALDH1A1 was associated with increasing stage (p=0.042 over stages 2, 3b, 3c, and 4) while loss of CD29 expression exhibited a trend toward being associated with stages 3 and 4 (p=0.08). Compared to normal colon tissue, primary tumors were associated with increased expression of ALDH1B1 (p=0.008). ALD1H1B1 expression level differed according to whether the tumor was moderately or poorly differentiated, well differentiated, or mucinous; the highest expression levels were associated with moderately or poorly differentiated tumors (p=0.011). Lymph node metastases were associated with a trend toward decreased expression of EpCAM (p = 0.06) when comparing 0 vs. 1 vs. 2+ positive lymph nodes, as was CD29 (p = 0.08) when comparing 0 vs. any positive lymph nodes. Compared to normal colon tissue metastatic colon cancers from different patients were associated with increased ALDH1B1 expression (p=0.001) whereas CD29 expression was higher in normal colonic tissue (p=0.014).

Conclusion: CD29 may be associated with survival as well as clinical stage and number of lymph nodes. ALDH1B1 expression was associated with differentiation as well as type of tissue evaluated. ALDH1A1 was associated with clinical stage, and decreased EpCAM expression was found in patients with advanced lymph node stage. CRCSCs may be useful biomarkers to risk stratify, and estimate outcomes in CRC. Larger prospective studies are required to validate the current findings.

Cancer stem cells hypothesis and stem cells in head and neck cancers

There is increasing evidence that the growth and spread of cancer is driven by a small subpopulation of cancer cells, defined as cancer stem cells (CSCs). Recent data indicate that the initiation, growth, recurrence and metastasis of cancers are related to the behavior of a small population of malignant cells with properties of stem cells, and information about them are potentially helpful in identifying the target for the tumor's therapeutic elimination. The presence of subpopulation cells with phenotypic and behavioral characteristics corresponding to both normal epithelial stem cells and to cells capable of initiating tumors has been also reported in head and neck squamous cell carcinomas (HNSCCs).

NDRG2 down-regulation and CD24 up-regulation promote tumor aggravation and poor survival in patients with gallbladder carcinoma

Recent studies have demonstrated that N-Myc downstream-regulated gene 2 (NDRG2) may reduce the metastatic potential of breast cancer and hepatocellular carcinoma cells by regulating the expression of CD24, which is expressed in a large variety of solid tumors. The aim of this study was to clarify the clinical value of NDRG2 and CD24 expression in primary gallbladder carcinoma (GBC). One hundred and thirty GBC tissues were evaluated by immunohistochemistry for NDRG2 and CD24 expression. The associations of NDRG2 and CD24 expression with the clinicopathological characteristics and the overall survival of patients with GBC were analyzed. NDRG2 and CD24 were positively expressed in 49/130 (37.69%) and 107/130 (82.31%) of GBC tissues, respectively. In addition, the tumors with the down-regulation of NDRG2 and the up-regulation of CD24 more frequently had lymph node metastasis and lymphovascular invasion. Moreover, the tumors with the down-regulation of NDRG2 and the up-regulation of CD24 tended to show deeper invasion depth and higher TNM stage. There was a negative correlation between NDRG2 expression and CD24 expression in GBC tissues (r = -0.86, P < 0.001). The patients with NDRG2 negative expression correlated with poor prognosis of GBC (P = 0.01), as opposed to CD24 (P = 0.01). The survival rate of the patients with NDRG2-/CD24+ expression was the lowest (P < 0.001), and conjoined expression of NDRG2-/CD24+ was an independent prognostic indicator of GBC (P = 0.003). Our data suggest that NDRG2 down-regulation or CD24 up-regulation is an important feature of GBC. A combined detection of NDRG2/CD24 co-expression may benefit us in prediction of the prognosis in GBC.

Immunophenotyping analysis in invasive micropapillary carcinoma of the breast: role of CD24 and CD44 isoforms expression

We analyzed immunohistochemically the expression of CD24 and spliced variants of CD44v5 and v9 in invasive micropapillary carcinoma (IMPC) of the breast that is a rather aggressive tumor characterized by alteration of cells adhesion molecules, early lymph node metastases and poor prognosis. We analyzed 31 high-grade IMPCs and compared their expression to 22 high grade (G3) invasive ductal carcinomas of the breast (IDCs). We found a higher expression of CD24 in high-grade IMPCs with a peculiar inverted apical localization, compared to IDCs, showing a strong cytoplasmic staining; normal breast tissue resulted completely negative. IMPCs showed reduced expression of CD44v5 and CD44v9 compared with IDCs, but without a statistical significant difference. This study demonstrated that IMPC represents a distinct entity of breast carcinoma with high expression of CD24 with a typical inverted apical membrane pattern and reduction of CD44 isoforms v5 and v9, compared to IDCs. These features could explain the high lymph-vascular invasion propensity and higher metastatic capability of these tumors and could be a useful tool for a future targeted therapy.

The CD24 protein inducible expression system is an ideal tool to explore the potential of CD24 as an oncogene and a target for immunotherapy in vitro and in vivo

CD24 is a cell surface, heavily glycosylated glycosylphosphatidylinositol-anchored mucin-like protein that is overexpressed in various human malignancies. To accurately analyze CD24 function and dissect its biological role in a defined genetic background, it is critical to tightly regulate its expression and be able to turn it on/off in a restricted environment and at a specific time. The tetracycline-induced expression system is most promising as it exhibits such regulation, lack of pleiotropic effects, and high and rapid induction levels. To evaluate the oncogenic and immunotherapeutic potential of CD24 by applying the Tet-On system, the human CD24 gene was cloned downstream to two tetracycline operator sequences, resulting in pCDNA4/TO-CD24, which was then transfected into tetracycline (Tet) repressor-expressing cells (293T-REx), allowing tight on/off regulation, thereby resulting in a very low background or leaky CD24 expression. Selected clones were chosen for further studies and characterized in vitro and in vivo, and several treatment modalities were examined. In addition, the role of CD24 in promoting cell proliferation and tumor growth was studied. The tetracycline-dependent system was successfully implemented. Tetracycline treatment induced CD24 expression in a dose- and time-dependent fashion, which was abrogated following treatment with anti-CD24 monoclonal antibodies (mAbs). CD24-induced expression led to an increased proliferation rate that was inhibited by mAb treatment. In vivo, significantly larger tumors were developed in tetracycline-fed mice. The CD24 Tet-On system is a good model to unravel the role and underlying CD24 pathogenesis in vivo. This valuable tool allows the successful study of novel treatment options, whose effectiveness depends on the CD24 expression level. This set of experiments supports CD24 oncogenic properties.

NDRG2 inhibits hepatocellular carcinoma adhesion, migration and invasion by regulating CD24 expression

BACKGROUND

The prognosis of most hepatocellular carcinoma (HCC) patients is poor due to the high metastatic rate of the disease. Understanding the molecular mechanisms underlying HCC metastasis is extremely urgent. The role of CD24 and NDRG2 (N-myc downstream-regulated gene 2), a candidate tumor suppressor gene, has not yet been explored in HCC.

METHODS

The mRNA and protein expression of CD24 and NDRG2 was analyzed in MHCC97H, Huh7 and L-02 cells. Changes in cell adhesion, migration and invasion were detected by up- or down-regulating NDRG2 by adenovirus or siRNA. The expression pattern of NDRG2 and CD24 in HCC tissues and the relationship between NDRG2 and HCC clinical features was analyzed by immunohistochemical and western blotting analysis.

RESULTS

NDRG2 expression was negatively correlated with malignancy in HCC. NDRG2 exerted anti-tumor activity by regulating CD24, a molecule that mediates cell-cell interaction, tumor proliferation and adhesion. NDRG2 up-regulation decreased CD24 expression and cell adhesion, migration and invasion. By contrast, NDRG2 down-regulation enhanced CD24 expression and cell adhesion, migration and invasion. Immunohistochemical analysis of 50 human HCC clinical specimens showed a strong correlation between NDRG2 down-regulation and CD24 overexpression (P = 0.04). In addition, increased frequency of NDRG2 down-regulation was observed in patients with elevated AFP serum level (P = 0.006), late TNM stage (P = 0.009), poor differentiation grade (P = 0.002), tumor invasion (P = 0.004) and recurrence (P = 0.024).

CONCLUSIONS

Our findings indicate that NDRG2 and CD24 regulate HCC adhesion, migration and invasion. The expression level of NDRG2 is closely related to the clinical features of HCC. Thus, NDRG2 plays an important physiological role in HCC metastasis.

NDRG2 inhibits hepatocellular carcinoma adhesion, migration and invasion by regulating CD24 expression

BACKGROUND

The prognosis of most hepatocellular carcinoma (HCC) patients is poor due to the high metastatic rate of the disease. Understanding the molecular mechanisms underlying HCC metastasis is extremely urgent. The role of CD24 and NDRG2 (N-myc downstream-regulated gene 2), a candidate tumor suppressor gene, has not yet been explored in HCC.

METHODS

The mRNA and protein expression of CD24 and NDRG2 was analyzed in MHCC97H, Huh7 and L-02 cells. Changes in cell adhesion, migration and invasion were detected by up- or down-regulating NDRG2 by adenovirus or siRNA. The expression pattern of NDRG2 and CD24 in HCC tissues and the relationship between NDRG2 and HCC clinical features was analyzed by immunohistochemical and western blotting analysis.

RESULTS

NDRG2 expression was negatively correlated with malignancy in HCC. NDRG2 exerted anti-tumor activity by regulating CD24, a molecule that mediates cell-cell interaction, tumor proliferation and adhesion. NDRG2 up-regulation decreased CD24 expression and cell adhesion, migration and invasion. By contrast, NDRG2 down-regulation enhanced CD24 expression and cell adhesion, migration and invasion. Immunohistochemical analysis of 50 human HCC clinical specimens showed a strong correlation between NDRG2 down-regulation and CD24 overexpression (P = 0.04). In addition, increased frequency of NDRG2 down-regulation was observed in patients with elevated AFP serum level (P = 0.006), late TNM stage (P = 0.009), poor differentiation grade (P = 0.002), tumor invasion (P = 0.004) and recurrence (P = 0.024).

CONCLUSIONS

Our findings indicate that NDRG2 and CD24 regulate HCC adhesion, migration and invasion. The expression level of NDRG2 is closely related to the clinical features of HCC. Thus, NDRG2 plays an important physiological role in HCC metastasis.

An immunoconjugate of anti-CD24 and Pseudomonas exotoxin selectively kills human colorectal tumors in mice

BACKGROUND & AIMS

Effective and selective treatment options are needed for patients with colorectal cancer (CRC). The CD24 mucin-like glycoprotein is overexpressed in CRCs; monoclonal antibodies (mAbs) against CD24 inhibit tumor cell growth in vitro and in vivo. Based on the tumor-specific expression of CD24, we investigated the potential of anti-CD24 SWA11 mAb, to deliver a cytotoxic agent into CRC cells.

METHODS

We conjugated SWA11 to a Pseudomonas exotoxin derivative (PE38) via an Fc-binding ZZ domain from Staphylococcal protein A (which binds the Fc domain of mouse IgG2a immunoglobulins) to generate the immunotoxin SWA11-ZZ-PE38; IgG-ZZ-PE38 was used as control. Human HT-29 and COLO320 (CD24-positive) and HCT116 (CD24-negative) CRC cell lines were assayed for immunotoxin binding, cytotoxicity, viability, and apoptosis. Toxicity and antitumor efficacy were tested in mice.

RESULTS

The immunotoxin preserved the affinity and specificity of SWA11, bound and selectively killed CD24-expressing CRC cells via apoptosis. IC(50) values ranged from 20 to 50 ng/mL-several orders of magnitude lower than that of the mAb alone. The immunotoxins were not toxic to mice at the maximum dose of 0.75 mg/kg. Growth of HT-29 xenograft tumors was significantly reduced in mice given SWA11-ZZ-PE38 (by 78%) compared to untreated mice.

CONCLUSIONS

Anti-CD24 SWA11 mAb can deliver a PE exotoxin derivative to CRC cells and cause them to undergo apoptosis, without toxicity to normal tissues. This immunotoxin might be developed as a therapeutic treatment for patients with CRC.

Stem cells in colon cancer. A new era in cancer theory begins

INTRODUCTION

Despite the various therapeutic combinations and the emergence of new targeted therapies, there is still no curative treatment for all stages of colorectal cancer. Through the query for the best possible combination and solution, a new theory approaching colorectal cancer as a stem cell disease appeared, with a continuously growing body of evidence supporting this idea. The inability to directly recognize cancer stem cells has led researchers to an attempt of distinguishing those using indirect markers.

DISCUSSION

This review focuses on colon cancer stem cell theory, the various findings supporting and contradicting this hypothesis, and the markers used up to now in characterizing stem cell populations in colorectal cancer. Despite the numerous unanswered questions on this new cancer hypothesis, it appears to have a justifiable role to play in colorectal cancer tumor biology, and furthermore, it may be the basis for the development of new therapeutic agents of the future. Therefore, every surgeon, oncologist, and physician who is implicated with this disease should be familiar with this novel colorectal cancer theory.

Epithelial mesenchymal transition traits in human breast cancer cell lines parallel the CD44(hi/)CD24 (lo/-) stem cell phenotype in human breast cancer

We review here the recently emerging relationship between epithelial-mesenchymal transition (EMT) and breast cancer stem cells (BCSC), and provide analyses of published data on human breast cancer cell lines, supporting their utility as a model for the EMT/BCSC state. Genome-wide transcriptional profiling of these cell lines has confirmed the existence of a subgroup with mesenchymal tendencies and enhanced invasive properties ('Basal B'/Mesenchymal), distinct from subgroups with either predominantly luminal ('Luminal') or mixed basal/luminal ('Basal A') features (Neve et al. Cancer Cell, 2006). A literature-derived EMT gene signature has shown specific enrichment within the Basal B subgroup of cell lines, consistent with their over-expression of various EMT transcriptional drivers. Basal B cell lines are found to resemble BCSC, being CD44(high)CD24(low). Moreover, gene products that distinguish Basal B from Basal A and Luminal cell lines (Basal B Discriminators) showed close concordance with those that define BCSC isolated from clinical material, as reported by Shipitsin et al. (Cancer Cell, 2007). CD24 mRNA levels varied across Basal B cell lines, correlating with other Basal B Discriminators. Many gene products correlating with CD24 status in Basal B cell lines were also differentially expressed in isolated BCSC. These findings confirm and extend the importance of the cellular product of the EMT with Basal B cell lines, and illustrate the value of analysing these cell lines for new leads that may improve breast cancer outcomes. Gene products specific to Basal B cell lines may serve as tools for the detection, quantification, and analysis of BCSC/EMT attributes.

Sox9 expression marks a subset of CD24-expressing small intestine epithelial stem cells that form organoids in vitro

The inability to identify, isolate, and culture intestinal epithelial stem cells (IESCs) has been prohibitive to the study and therapeutic utilization of these cells. Using a Sox9(EGFP) mouse model, we demonstrate that Sox9(EGFP) fluorescence signatures can be used to differentiate between and enrich for progenitors (Sox9(EGFPsubLo)) and multipotent IESCs (Sox9(EGFPlo)). Sox9(EGFPlo) cells generate "organoids" in a recently defined culture system that mimics the native IESC niche. These organoids possess all four differentiated cell types of the small intestine epithelium, demonstrating the multipotent capacity of Sox9(EGFPlo) cells. Our results are consistent with the previously reported observation that single IESCs generate cryptlike units without a detectable mesenchymal cell component. A prospective search revealed that CD24 is expressed in the Sox9(EGFPlo) population and marks IESCs that form organoids in culture. CD24 represents the first cell surface marker that facilitates fluorescence-activated cell sorting enrichment of IESCs with widely available antibodies without requiring a specialized fluorescent reporter gene mouse model.

CD24 and galectin-1 expressions in gastric adenocarcinoma and clinicopathologic significance

CD24 and galectin-1 expression in gastric adenocarcinoma and their clinicopathologic significance remained largely unknown. We aimed to evaluate expressions and staining intensities of CD24 and galectin-1 in gastric adenocarcinoma and to investigate the interrelation with clinicopathologic parameters including survival. 93 cases with gastric adenocarcinoma were reevaluated histopathologically and immunohistochemistry was performed with antibodies against CD24 and galectin-1. Staining intensities of both markers in tumor cells and staining intensity of galectin-1 in tumor-associated stromal cells were scored semiquantitatively. The relationship between expression and staining intensity of CD24 and galectin-1 and clinicopathologic variables were assessed. CD24 staining intensity was associated with lymphovascular invasion (p = 0.007), serosal invasion (p = 0.001), stage (p = 0.001) and lymph node metastasis (p = 0.005). Galectin-1 staining intensity in tumor-associated stromal cells was associated with tumor location (p = 0.031), lymphovascular invasion (p = 0.001), perineural invasion (p = 0.001), serosal invasion (p = 0.001), differentiation (p = 0.003), stage (p = 0.001) and lymph node metastasis (p = 0.001). Staining intensity of CD24 (p = 0.019) and gal-1 (p = 0.018) were associated with patient survival. Staining intensity of CD24 in tumor cells and galectin-1 in tumor-associated stromal cells were related with certain clinicopathologic variables. Our findings suggest that these markers are independent prognostic indicators of poor survival and may serve as useful targets for novel therapies.