Search

Background: Cancer stem cells (CSCs) are crucial for lung adenocarcinoma (LUAD). This study investigates tumor stem cell gene signatures in LUAD using single-cell RNA sequencing (scRNA-seq) and bulk RNA sequencing (RNA-seq), aiming to develop a prognostic tumor stem cell marker signature (TSCMS) model. Methods: LUAD scRNA-seq and RNA-seq data were analyzed. CytoTRACE software quantified the stemness score of tumor-derived epithelial cell clusters. Gene Set Variation Analysis (GSVA) identified potential biological functions in different clusters. The TSCMS model was constructed using Lasso-Cox regression, and its prognostic value was assessed through Kaplan–Meier, Cox regression, and receiver-operating characteristic (ROC) curve analyses. Immune infiltration was evaluated using the Cibersortx algorithm, and drug response prediction was performed using the pRRophetic package. TAF10 functional investigations in LUAD cells involved bioinformatics analysis, qRT-PCR, Western blot, immunohistochemistry, and assays for cell proliferation. Results: Seven distinct cell clusters were identified by CytoTRACE, with epithelial cell cluster 1 (Epi_C1) showing the highest stemness potential. The TSCMS model included 49 tumor stemness-related genes; high-risk patients exhibited lower immune and ESTIMATE scores and increased tumor purity. Significant differences in immune landscapes and chemotherapy sensitivity were observed between risk groups. TAF10 positively correlated with RNA expression-based stemness scores in various tumors, including LUAD. It was over-expressed in LUAD cell lines and clinical tumor tissues, with high expression linked to poor prognosis. Silencing TAF10 inhibited LUAD cell proliferation and tumor sphere formation. Conclusions: This study demonstrates the TSCMS model's prognostic value in LUAD, reveals insights into immune infiltration and therapeutic response, and identifies TAF10 as a potential therapeutic target. [ABSTRACT FROM AUTHOR]

Background: Colorectal cancer (CRC) is a malignancy that arises within the gastrointestinal tract. Despite ongoing research, the etiology and pathogenesis of CRC remain elusive; particularly, the distribution and characteristics of tumor‐associated macrophages is currently an active area of investigation in understanding the pathological progression and prevention of CRC. Methods: This study utilized CRC patient surgical samples, mouse models of colitis‐associated cancer, colonic organoid, and co‐culture cell line to examine the changes in CD11b/CD86 at different pathological region and detect the Wnt signaling pathway activity. Results: Our findings revealed a sensitive and increased expression of CD11b from the early to the advanced CRC tissues and correlated with poor prognosis, while CD86 expression was reduced in advanced CRC tissues. CD133 expression was also elevated in advanced CRC tissues and mainly co‐localized with CD11b, suggesting a positive regulatory effect of CD11b and CD133 expression that may contribute to CRC progression. In AOM/DSS mouse models, activation of the Wnt signaling pathway was associated with increased CD133 and CD11b expression. In vitro, THP‐1 cell was induced to high expression of CD11b, and the above conditional cultural medium enhanced HCT116 cell colony number and CD133 protein expression. Furthermore, colonic crypts from AOM/DSS mouse models were isolated to culture, and the colonic organoids exhibited dilation and significant increases expression of CD133 and β‐Catenin/N‐P‐B‐Catenin. Conclusions: CD11b might be an important factor to participate the progress of CRC. And the high CD11b of CRC microenviroment might potentially promote CD133 expression and associate with Wnt signal activation. [ABSTRACT FROM AUTHOR]

Abstract Objective Tumors are highly heterogeneous, and within their parenchyma, a small population of tumor-stem cells possessing differentiation potential, high oncogenicity, and self-renewal capabilities exists. These cells are pivotal in mediating tumor development, chemotherapy resistance, and recurrence. Ovarian cancer shares characteristics with tumor stem cells, making it imperative to investigate molecular markers associated with these cells. Methods Stem cell-related genes were collected, and molecular subtypes were established based on gene expression profiles from The Cancer Genome Atlas using the R package tool “ConsensusClusterPlus.” Multi-gene prognostic markers were identified using LASSO regression analysis. Gene set enrichment analysis was employed to gain insights into the potential molecular mechanisms of these identified markers. The robustness of these prognostic markers was analyzed across different cohorts, and their clinical independence was determined through multivariate Cox analysis. A nomogram was constructed to assess the model’s clinical applicability. Immunohistochemistry was performed to validate the expression of hub genes. Results Utilizing 49 tumor stem cell-related genes associated with prognosis, 362 ovarian cancer samples were divided into two distinct clusters, revealing significant prognostic disparities. A seven-gene signature (GALP, CACNA1C, COL16A1, PENK, C4BPA, PSMA2, and CXCL9), identified through LASSO regression, exhibited stability and robustness across various platforms. Multivariate Cox regression analysis confirmed the signature’s independence in predicting survival in patients with ovarian cancer. Furthermore, a nomogram combining the gene signature demonstrated strong predictive abilities. Immunohistochemistry results indicated significantly elevated GALP, CACNA1C, COL16A1, PENK, C4BPA, PSMA2, and CXCL9 expression in cancer tissues. Conclusion The seven-gene signature holds promise as a valuable tool for decision-making and prognosis prediction in patients with ovarian cancer.

Objective: Tumors are highly heterogeneous, and within their parenchyma, a small population of tumor-stem cells possessing differentiation potential, high oncogenicity, and self-renewal capabilities exists. These cells are pivotal in mediating tumor development, chemotherapy resistance, and recurrence. Ovarian cancer shares characteristics with tumor stem cells, making it imperative to investigate molecular markers associated with these cells. Methods: Stem cell-related genes were collected, and molecular subtypes were established based on gene expression profiles from The Cancer Genome Atlas using the R package tool "ConsensusClusterPlus." Multi-gene prognostic markers were identified using LASSO regression analysis. Gene set enrichment analysis was employed to gain insights into the potential molecular mechanisms of these identified markers. The robustness of these prognostic markers was analyzed across different cohorts, and their clinical independence was determined through multivariate Cox analysis. A nomogram was constructed to assess the model's clinical applicability. Immunohistochemistry was performed to validate the expression of hub genes. Results: Utilizing 49 tumor stem cell-related genes associated with prognosis, 362 ovarian cancer samples were divided into two distinct clusters, revealing significant prognostic disparities. A seven-gene signature (GALP, CACNA1C, COL16A1, PENK, C4BPA, PSMA2, and CXCL9), identified through LASSO regression, exhibited stability and robustness across various platforms. Multivariate Cox regression analysis confirmed the signature's independence in predicting survival in patients with ovarian cancer. Furthermore, a nomogram combining the gene signature demonstrated strong predictive abilities. Immunohistochemistry results indicated significantly elevated GALP, CACNA1C, COL16A1, PENK, C4BPA, PSMA2, and CXCL9 expression in cancer tissues. Conclusion: The seven-gene signature holds promise as a valuable tool for decision-making and prognosis prediction in patients with ovarian cancer. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect and regulatory mechanism of fucoxanthin (FX) on oral squamous cell carcinoma (OSCC). Methods: Human OSCC SCC9 and Cal27 cells were treated with different concentrations of FX (7.5, 15, and 30 µM) to determine cell viability, number of colonies, and apoptosis rate using methyl thiazolyl diphenyl-tetrazolium bromide (MTT) assay, crystal violet staining, and flow cytometry, respectively. In addition, the number of spheres of OSCC cells was determined by a cell sphere-forming assay. The stem cells and levels of pathway-related proteins were evaluated by western blotting. Results: Fucoxanthin decreased SCC9 and Cal27 cell viability and the number of colonies, but increased apoptosis in a dose-dependent manner. The expression levels of SOX2 and POU5F1 were down-regulated, while the number of spheres was reduced in SCC9 and Cal27 cells treated with 7.5 or 15 μM of FX (p < 0.05). Moreover, FX attenuated p-JAK/JAK and p-STAT3/STAT3 expression levels in a dose-dependent manner (p < 0.05). Conclusion: Fucoxanthin accelerates apoptosis and inhibits cell mobility and OSCC stem cell formation by suppressing JAK/STAT3 pathway in OSCC, thus providing an experimental basis for research on the anti-tumor effect of kelp extract and the development of new drugs from marine plants. [ABSTRACT FROM AUTHOR]

Tumor stem cells (TSCs), capable of self‐renewal and continuous production of progeny cells, could be potential therapeutic targets. We have recently reported that chromatin remodeling regulator Brg1 is required for maintenance of murine intestinal TSCs and stemness feature of human colorectal cancer (CRC) cells by inhibiting apoptosis. However, it is still unclear how BRG1 suppression changes the underlying intracellular mechanisms of human CRC cells. We found that Brg1 suppression resulted in upregulation of the JNK signaling pathway in human CRC cells and murine intestinal TSCs. Simultaneous suppression of BRG1 and the JNK pathway, either by pharmacological inhibition or silencing of c‐JUN, resulted in even stronger inhibition of the expansion of human CRC cells compared to Brg1 suppression alone. Consistently, high c‐JUN expression correlated with worse prognosis for survival in human CRC patients with low BRG1 expression. Therefore, the JNK pathway plays a critical role for expansion and stemness of human CRC cells in the context of BRG1 suppression, and thus a combined blockade of BRG1 and the JNK pathway could be a novel therapeutic approach against human CRC. [ABSTRACT FROM AUTHOR]

The recurrence rate of lymphoma is very high, and tumor stem cells may be an important mechanism. Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) can inhibit antitumor immunity and promote cancer progression, but its role and mechanism in lymphoma are still unclear. Here we collected lymphoma tissue and peripheral blood from patients with diffuse large B-cell lymphoma (DLBCL). Results showed that CTLA-4 expression and CD44+ cell in the high-risk group were significantly higher than that in the low-risk group. Correlation analysis showed that CTLA-4 expression positively correlated with CD44+ cell in lymphoma tissue and regulatory T (Treg) cells in lymphocytes. In vitro experiment showed that CTLA-4 increased the ratio of lymphoma stem cells, and proliferation and invasion of lymphoma cells through TGF-β pathway. Moreover, CTLA-4 enhanced the proliferation of Treg cells induced by lymphoma cells. Animal experiments showed that CTLA-4 can promote transplanted lymphoma growth. Immunohistochemistry results showed that both Ki-67 and CD44+ cells increased significantly in the CTLA-4 group. TGF-β neutralization can significantly block these effects of CTLA-4. In conclusion, CTLA-4 promoted DLBCL progression through lymphoma stem cell enrichment and immunosuppression.

The tumor microenvironment (TME) plays a key role in promoting the initiation and progression of tumors, leading to chemoradiotherapy resistance and immunotherapy failure. Targeting of the TME is a novel anti-tumor therapeutic approach and is currently a focus of anti-tumor research. Panax ginseng C. A. Meyer (ginseng), an ingredient of well-known traditional Asia medicines, exerts beneficial anti-tumor effects and can regulate the TME. Here, we present a systematic review that describes the current status of research efforts to elucidate the functions and mechanisms of ginseng active components (including ginsenosides and ginseng polysaccharides) for achieving TME regulation. Ginsenosides have variety effects on TME, such as Rg3, Rd and Rk3 can inhibit tumor angiogenesis; Rg3, Rh2 and M4 can regulate the function of immune cells; Rg3, Rd and Rg5 can restrain the stemness of cancer stem cells. Ginseng polysaccharides (such as red ginseng acidic polysaccharides and polysaccharides extracted from ginseng berry and ginseng leaves) can regulate TME mainly by stimulating immune cells. In addition, we propose a potential mechanistic link between ginseng-associated restoration of gut microbiota and the tumor immune microenvironment. Finally, we describe recent advances for improving ginseng efficacy, including the development of a nano-drug delivery system. Taken together, this review provides novel perspectives on potential applications for ginseng active ingredients as anti-cancer adjuvants that achieve anti-cancer effects by reshaping the tumor microenvironment.

Purpose: Our aim was to construct a signature that accurately predicted the prognostic and immune response of melanoma.Methods: First, the weighted co-expression network analysis (WGCNA) algorithm was used to identify the hub genes related to clinical phenotypes of melanoma in the cancer genome atlas (TCGA) database. Nest, the least absolute shrinkage and selection operator (LASSO) analysis was used to dimensionality reduction of these hub genes and constructed a prognostic signature to predict the prognosis and immunosuppressive response of melanoma.Result: Through in-depth analysis, we constructed a 5-mRNA prognostic signature and verified its prognostic value in internal (TCGA-SKCM, n = 452) and external independent datasets (GSE53118, n = 79). Based on this signature, the tumor immune microenvironment (TME) of melanoma was characterized, and the result was found that patients in the high-risk group had lower CD8 T cell infiltration and immune checkpoint expression (PD-1, PD-L1, CTLA4), as well as higher M0/M2 macrophage infiltration. Our results also found the risk score based on a 5-mRNA signature was significantly associated with tumor mutational burden (TMB) and tumor stem cell markers (CD20, CD38, ABCB5, CD44, etc.). Lastly, we built a nomogram for clinician prediction for the prognosis of patients with melanoma.Conclusion: Our findings indicated that the 5-mRNA signature has an important predictive value for the overall survival of melanoma. By analyzing the tumor immune microenvironment and tumor stem cell marker between different groups, a new method is provided for the stratified diagnosis and treatment of melanoma.

The tumor microenvironment (TME) plays a key role in promoting the initiation and progression of tumors, leading to chemoradiotherapy resistance and immunotherapy failure. Targeting of the TME is a novel anti-tumor therapeutic approach and is currently a focus of anti-tumor research. Panax ginseng C. A. Meyer (ginseng), an ingredient of well-known traditional Asia medicines, exerts beneficial anti-tumor effects and can regulate the TME. Here, we present a systematic review that describes the current status of research efforts to elucidate the functions and mechanisms of ginseng active components (including ginsenosides and ginseng polysaccharides) for achieving TME regulation. Ginsenosides have variety effects on TME, such as Rg3, Rd and Rk3 can inhibit tumor angiogenesis; Rg3, Rh2 and M4 can regulate the function of immune cells; Rg3, Rd and Rg5 can restrain the stemness of cancer stem cells. Ginseng polysaccharides (such as red ginseng acidic polysaccharides and polysaccharides extracted from ginseng berry and ginseng leaves) can regulate TME mainly by stimulating immune cells. In addition, we propose a potential mechanistic link between ginseng-associated restoration of gut microbiota and the tumor immune microenvironment. Finally, we describe recent advances for improving ginseng efficacy, including the development of a nano-drug delivery system. Taken together, this review provides novel perspectives on potential applications for ginseng active ingredients as anti-cancer adjuvants that achieve anti-cancer effects by reshaping the tumor microenvironment. [ABSTRACT FROM AUTHOR]

Tumor cells capable of self‐renewal and continuous production of progeny cells are called tumor stem cells (TSCs) and are considered to be potential therapeutic targets. However, the mechanisms underlying the survival and function of TSCs are not fully understood. We previously reported that chromatin remodeling regulator Brg1 is essential for intestinal stem cells in mice and Dclk1 is an intestinal TSC marker. In this study, we investigated the role of Brg1 in Dclk1+ intestinal tumor cells for the maintenance of intestinal tumors in mice. Specific ablation of Brg1 in Dclk1+ intestinal tumor cells reduced intestinal tumors in ApcMin mice, and continuous ablation of Brg1 maintained the reduction of intestinal tumors. Lineage tracing in the context of Brg1 ablation in Dclk1+ intestinal tumor cells revealed that Brg1‐null Dclk1+ intestinal tumor cells did not give rise to their descendent tumor cells, indicating that Brg1 is essential for the self‐renewal of Dclk1+ intestinal tumor cells. Five days after Brg1 ablation, we observed increased apoptosis in Dclk1+ tumor cells. Furthermore, Brg1 was crucial for the stemness of intestinal tumor cells in a spheroid culture system. BRG1 knockdown also impaired cell proliferation and increased apoptosis in human colorectal cancer (CRC) cells. Microarray analysis revealed that apoptosis‐related genes were upregulated and stem cell‐related genes were downregulated in human CRC cells by BRG1 suppression. Consistently, high BRG1 expression correlated with poor disease‐specific survival in human CRC patients. These data indicate that Brg1 plays a crucial role in intestinal TSCs in mice by inhibiting apoptosis and is critical for cell survival and stem cell features in human CRC cells. Thus, BRG1 represents a new therapeutic target for human CRC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Intestinal tumors mainly originate from transformed crypt stem cells supported by Wnt signaling, which functions through downstream critical factors enriched in the intestinal stem/progenitor compartment. Here, we show Uhrf2 is predominantly expressed in intestinal crypts and adenomas in mice and is transcriptionally regulated by Wnt signaling. Upregulated UHRF2 correlates with poor prognosis in colorectal cancer patients. Although loss of Uhrf2 did not affect intestinal homeostasis and regeneration, tumor initiation and progression were inhibited, leading to a markedly prolonged life span in Uhrf2 null mice on an ApcMin background. Uhrf2 deficiency also strongly reduced primary tumor organoid formation suggesting impairment of tumor stem cells. Moreover, ablation of Uhrf2 suppressed tumor cell proliferation through downregulation of the Wnt/β‐catenin pathway. Mechanistically, Uhrf2 directly interacts with and sumoylates Tcf4, a critical intranuclear effector of the Wnt pathway. Uhrf2 mediated SUMOylation stabilized Tcf4 and further sustained hyperactive Wnt signaling. Together, we demonstrate that Wnt‐induced Uhrf2 expression promotes tumorigenesis through modulation of the stability of Tcf4 for maintaining oncogenic Wnt/β‐catenin signaling. This is a new reciprocal feedforward regulation between Uhrf2 and Wnt signaling in tumor initiation and progression. What's new? UHRF2 has been shown to be enriched in intestinal stem cells and upregulated in colorectal cancer. However, the role of UHRF2 in intestinal homeostasis and tumorigenesis has not been explored in vivo. This study shows that Uhrf2 is expressed in mouse intestinal crypts and adenomas and is transcriptionally regulated by Wnt signaling. Uhrf2 further maintains oncogenic Wnt/β−catenin signaling through modulation of Tcf4 protein stability to enhance the stemness and tumorigenicity of intestinal progenitors. The findings reveal reciprocal feedforward regulation between Uhrf2 and Wnt signaling in tumor initiation and progression, and highlight Uhrf2 as a potential therapeutic target in colorectal cancer. [ABSTRACT FROM AUTHOR]

Extensive in vitro and in vivo research reveals multiple intracellular molecular targets of Antrodia camphorata, and these targets affect growth, apoptosis, angiogenesis, invasion and metastasis of cells. These targets include tumor suppressor, cell cycle regulator, transcription factor, angiogenesis and metastasis factor, apoptosis and survival regulator, etc. Additionally, more and more attention has been paid to the molecular mechanism of A. camphorata on the regulation of tumor stem cells. Meanwhile, there is evidence that the immunoregulation of A. camphorata is enhanced, which may lead cell cycle arrest or apoptosis. In this paper, molecular mechanism of tumor cells and tumor stem cells regulated at multiple targets by A. camphorata in vitro and in vivo in the past decade is summarized. [ABSTRACT FROM AUTHOR]

Background: Meningioma in the cerebellopontine angle (CPA) without dural attachment is extremely rare. We report a unique case of meningioma derived from the superior petrosal vein without dural attachment., Case Summary: A 44-year-old right-handed woman presented with a two-month history of headache and tinnitus. Brain magnetic resonance imaging showed a well-defined contrast-enhancing lesion in the right CPA without a dural tail sign. Tumor resection was performed using a right retro sigmoid approach. A dural attachment was not seen at the tentorium or posterior surface of the petrous pyramid. The tumor was firmly adherent to the superior petrosal vein. The origin site was cauterized and resected with the preservation of the superior petrosal vein. A diagnosis of meningothelial meningioma was made. The patient's headache and tinnitus gradually disappeared, and a recurrence was not observed five years after the surgery., Conclusion: The rare occurrence of meningioma without dural attachment makes it difficult to determine dural attachment before surgery. The absence of dural attachment makes it easy to completely resect such tumors. Vessels related to tumors should be removed carefully, considering the possible presence of tumor stem cells in the microvessels., Competing Interests: Conflict-of-interest statement: The authors declare that they have no potential or actual conflicts of interest with regard to this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Triptolide, an ingredient of Tripterygium wilfordii, has been demonstrated to possess many biological activities such as immunomodulatory, antitumor activity in experiment. The purpose of this study was to survey the toxicity of TPL-PEI-CyD on renal cells and its effects on breast carcinoma stem cells. The cytotoxicity of TPL-PEI-CyD and TPL on HK-2 was comparatively assessed by CCK-8. After incubation and culturing with TGF-ß1, the MCF-7 cells were assessed by flow cytometry for the proportion of CD44+ CD24- cells; then the were sorted by immunomagnetic beads as MCF-7 stem cells. To assess the effect of TPL-PEI-CyD on MCF-7 stem cells, Western Blot was used to detect the expression of Oct-4 and ALDHl in MCF-7 stem cells after being dosed with TPL-PEI-CyD. Results showed that, compared with TPL, the toxicity of TPL-PEI-CyD on HK-2 cells was significantly reduced (P<0.05). Breast carcinoma stem cells can be enriched by TGF-ß1 and isolated from MCF-7 cells by immunomagnetic sorting. TPL-PEI-CyD can even more significantly suppress the expression of Oct-4 and ALDHA1 in MCF-7 stem cells than TPL (P<0.05). In conclusion, after coupling TPL and PEI-CyD, TPL-PEI-CyD showed characteristics of effective suppression to breast carcinoma stem cell and decrease of cytotoxicity. It presented the unique effect of traditional Chinese medicine as an efficient and low toxic drug carrier complex for breast carcinoma treatment. [ABSTRACT FROM AUTHOR]

The peroxisome proliferator-activated receptor delta (PPARD) regulates cell metabolism, proliferation, and inflammation and has been associated with gastric and other cancers. Villin-positive epithelial cells are a small population of quiescent gastric progenitor cells. We expressed PPARD from a villin promoter to investigate the role of these cells and PPARD in development of gastric cancer. We analyzed gastric tissues from mice that express the Ppard (PPARD1 and PPARD2 mice) from a villin promoter, and mice that did not carry this transgene (controls), by histology and immunohistochemistry. We performed cell lineage-tracing experiments and analyzed the microbiomes, chemokine and cytokine production, and immune cells and transcriptomes of stomachs of these mice. We also performed immunohistochemical analysis of PPARD levels in 2 sets of human gastric tissue microarrays. Thirty-eight percent of PPARD mice developed spontaneous, invasive gastric adenocarcinomas, with severe chronic inflammation. Levels of PPARD were increased in human gastric cancer tissues, compared with nontumor tissues, and associated with gastric cancer stage and grade. We found an inverse correlation between level of PPARD in tumor tissue and patient survival time. Gastric microbiomes from PPARD and control mice did not differ significantly. Lineage-tracing experiments identified villin-expressing gastric progenitor cells (VGPCs) as the origin of gastric tumors in PPARD mice. In these mice, PPARD up-regulated CCL20 and CXCL1, which increased infiltration of the gastric mucosa by immune cells. Immune cell production of inflammatory cytokines promoted chronic gastric inflammation and expansion and transformation of VGPCs, leading to tumorigenesis. We identified a positive-feedback loop between PPARD and interferon gamma signaling that sustained gastric inflammation to induce VGPC transformation and gastric carcinogenesis. We found PPARD overexpression in VPGCs to result in inflammation, dysplasia, and tumor formation. PPARD and VGPCs might be therapeutic targets for stomach cancer. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that cancer cells with increased levels of aldehyde dehydrogenase ‘bright’ activity (ALDHbr) exhibit stem cell properties compared with cells exhibiting decreased ALDH activity (ALDHlow). To screen possible biomarkers of cancer stem cells in tongue squamous cell carcinoma, ALDHbr and ALDHlow cells were isolated from the tongue squamous cell carcinoma TCA8113 cell line, and suppression subtractive hybridization was performed to identify differentially expressed genes in the two subpopulations. A total of 240 positive clones were randomly selected for sequencing and were functionally characterized using bioinformatical tools. The results of the present study identified the differential expression of 104 clones, 62 of which corresponded to known genes and 42 of which corresponded to unknown genes. Cluster analysis revealed that the known genes were involved in the regulation of the cell cycle and cell differentiation. In addition, analysis of 10 signaling pathways revealed that genes were markedly altered in the ALDHbr cell subpopulation. Additional study is required to identify the function that these genes serve in the biomolecular regulatory mechanisms of cancer stem cells and to assist in explaining the biological behavior of oral squamous cell carcinoma. [ABSTRACT FROM AUTHOR]

The dual specificity phosphatases (DUSPs) constitute a family of stress-induced enzymes that provide feedback inhibition on mitogen-activated protein kinases (MAPKs) critical in key aspects of oncogenic signaling. While described in other tumor types, the landscape of DUSP mRNA expression in glioblastoma (GB) remains largely unexplored. Interrogation of the REpository for Molecular BRAin Neoplasia DaTa (REMBRANDT) revealed induction ( DUSP4, DUSP6), repression ( DUSP2, DUSP7-9), or mixed ( DUSP1, DUSP5, DUSP10, DUSP15) DUSP transcription of select DUSPs in bulk tumor specimens. To resolve features specific to the tumor microenvironment, we searched the Ivy Glioblastoma Atlas Project (Ivy GAP) repository, which highlight DUSP1, DUSP5, and DUSP6 as the predominant family members induced within pseudopalisading and perinecrotic regions. The inducibility of DUSP1 in response to hypoxia, dexamethasone, or the chemotherapeutic agent camptothecin was confirmed in GB cell lines and tumor-derived stem cells (TSCs). Moreover, we show that loss of DUSP1 expression is a characteristic of TSCs and correlates with expression of tumor stem cell markers in situ (ABCG2, PROM1, L1CAM, NANOG, SOX2). This work reveals a dynamic pattern of DUSP expression within the tumor microenvironment that reflects the cumulative effects of factors including regional ischemia, chemotherapeutic exposure among others. Moreover, our observation regarding DUSP1 dysregulation within the stem cell niche argue for its importance in the survival and proliferation of this therapeutically resistant population. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate whether the inhibition of cluster of differentiation (CD)44 expression reduces the tumorigenicity of CD44+ cancer stem cells in hypopharyngeal cancer. To assess this, effective recombinant CD44 short hairpin RNA-expressing lentiviruses were produced. Lentivirus-mediated RNA interference (RNAi) was then used to knockdown CD44 gene expression in the hypopharyngeal cancer FaDu cell line. The viability of FaDu cells in the two control groups and the RNAi group (RNAi-CD44 lentiviral vector) was detected using an MTT assay in vitro. Cells from each group were injected into non-obese diabetic/severe combined immunodeficiency mice and their tumorigenicity determined in vivo. Following lentivirus-mediated RNAi, an MTT assay indicated that cells from the RNAi group exhibited lower viability than the control group. The in vivo tumorigenicity study further revealed a significant difference in tumorigenic rates between the RNAi group and the control group (Fisher's exact test, P<0.05). In addition, tumors in the RNAi group of animals had a longer incubation period than those in the control groups, and the mean tumor volume was also significantly smaller (t=3.47, P<0.05). Pathological study confirmed that all tumors were poorly differentiated squamous cell carcinomas with cellular heterogeneity. The viability of the hypopharyngeal cancer FaDu cells in vitro and their tumorigenicity in vivo were markedly inhibited once CD44 was knocked down. The results of the present study therefore suggest that CD44 may confer tumorigenic characteristics upon CD44+ cancer stem cells in hypopharyngeal cancer. [ABSTRACT FROM AUTHOR]

MicroRNA (miR)-21 has many regulatory functions in the cell, including activities in cancer cells and cancer stem cells. Large tumor suppressor gene 1 (LATS1) is a target of miR-21 that could mediate several of these phenotypes. This study explored the effect of miR-21 silencing in renal cancer cell function and LATS1 expression. Silencing of miR-21 in Caki-2 cells reached an efficiency of 55-60%. This was sufficient to detect decrease in Caki-2 cell proliferation and migration invasion capacity. miR-21 silencing increased LATS1 expression at both mRNA and protein levels. The number of tumor spheres formed by cells expressing si-miR-21 was significantly reduced and the expression of tumor stem cell markers Nanog and CT3/4 were significantly downregulated. miR-21 seems to regulate LATS1 expression in renal cancer Caki-2 cells, resulting in reduced proliferation, invasion, and cancer stem cell phenotype. miR-21 may promote malignant phenotype of tumor cells through LATS1 silencing, which can be regarded as a new target candidate gene for renal cancer treatment. [ABSTRACT FROM AUTHOR]

Gliomas are among the most lethal cancers, being highly resistant to both chemo- and radiotherapy. The expression of junctional adhesion molecule-A (JAM-A) was recently identified on the surface of stem cell-like brain tumor-initiating cells and suggested to function as a unique glioblastoma niche adhesion factor influencing the tumorigenic potential of brain tumor-initiating cells. We have recently identified high JAM-A expression to be associated with poor outcome in glioblastomas, and our aim was to further investigate the expression of JAM-A in gliomas focusing especially on the prognostic value in WHO grade II and III gliomas. JAM-A protein expression was evaluated by immunohistochemistry and advanced quantitative image analysis with continuous estimates of staining intensity. The JAM-A antibody stained tumor cell membranes and cytoplasm to various extent in different glioma subtypes, and the intensity was higher in glioblastomas than low-grade gliomas. We could not detect an association with overall survival in patients with grade II and III tumors. Double-immunofluorescence stainings in glioblastomas revealed co-expression of JAM-A with CD133, SOX2, nestin, and GFAP in tumor cells as well as some co-expression with the microglial/macrophage marker IBA-1. In conclusion, JAM-A expression was higher in glioblastomas compared to low-grade gliomas and co-localized with recognized stem cell markers suggesting an association of JAM-A with glioma aggressiveness. No significant association between JAM-A expression and overall survival was found in grade II and III gliomas. Further research is needed to determine the function and clinical impact of JAM-A in gliomas. [ABSTRACT FROM AUTHOR]

Embryonic stem cell (ESC) markers are molecules specifically expressed in ES cells. Understanding of the functions of these markers is critical for characterization and elucidation for the mechanism of ESC pluripotent maintenance and self-renewal, therefore helping to accelerate the clinical application of ES cells. Unfortunately, different cell types can share single or sometimes multiple markers; thus the main obstacle in the clinical application of ESC is to purify ES cells from other types of cells, especially tumor cells. Currently, the marker-based flow cytometry (FCM) technique and magnetic cell sorting (MACS) are the most effective cell isolating methods, and a detailed maker list will help to initially identify, as well as isolate ESCs using these methods. In the current review, we discuss a wide range of cell surface and generic molecular markers that are indicative of the undifferentiated ESCs. Other types of molecules, such as lectins and peptides, which bind to ESC via affinity and specificity, are also summarized. In addition, we review several markers that overlap with tumor stem cells (TSCs), which suggest that uncertainty still exists regarding the benefits of using these markers alone or in various combinations when identifying and isolating cells.

Serine has been recently identified as an essential metabolite for oncogenesis, progression, and adaptive immunity. Influenced by many physiologic or tumor environmental factors, the metabolic pathways of serine synthesis, uptake, and usage are heterogeneously reprogrammed and frequently amplified in tumor or tumor-associated cells. The hyperactivation of serine metabolism promotes abnormal cellular nucleotide/protein/lipid synthesis, mitochondrial function, and epigenetic modifications, which drive malignant transformation, unlimited proliferation, metastasis, immunosuppression, and drug resistance of tumor cells. Dietary restriction of serine or phosphoglycerate dehydrogenase depletion mitigates tumor growth and extends the survival of tumor patients. Correspondingly, these findings triggered a boom in the development of novel therapeutic agents targeting serine metabolism. In this study, recent discoveries in the underlying mechanism and cellular function of serine metabolic reprogramming are summarized. The vital role of serine metabolism in oncogenesis, tumor stemness, tumor immunity, and therapeutic resistance is outlined. Finally, some potential tumor therapeutic concepts, strategies, and limitations of targeting the serine metabolic pathway are described in detail. Taken together, this review underscores the importance of serine metabolic reprogramming in tumorigenesis and progression and highlights new opportunities for dietary restriction or selective pharmacologic intervention., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Tumor stem cell theory may well explain a variety of malignant behaviors of tumors. Cells undergoing epithelial-mesenchymal transition (EMT) share many characteristics with tumor stem cells. Our previous studies showed that extracellular -5'- nucleotidase (CD73), one of the important surface markers of mesenchymal stem cells, may promote growth and metastasis of breast cancer cells both in vivo and in vitro. In this study, we assessed breast cancer stem cell (BCSC) markers [acetaldehyde dehydrogenase (ALDH) and CD44CD24] in various breast cancer cell lines with flow cytometry after overexpression (by lentivirus infection) or suppression (by siRNA interference) of CD73. We measured CD73 expression in breast cancer mammospheres with real-time PCR and western blots. Finally, we examined the expression of CD73 and EMT markers in different breast cancer cell lines, as well as in mammary cells (MCF10A) that underwent EMT induced by transforming growth factor beta (TGF-β). We found that CD73 positively correlated with ALDH or CD44CD24 subsets of breast cancer cells. CD73 was expressed more in breast cancer mammospheres than in adherent cells. CD73 and mesenchymal marker expression was higher in breast cancer cells with more malignant features, while CD73 was lower in low malignant breast cancer cells with higher epithelial markers. Furthermore, CD73 expression increased during the process of TGF-β-induced EMT. Our results indicate that CD73 may play an important role in BCSCs. [ABSTRACT FROM AUTHOR]

Glioblastomas always recur despite surgery, radiotherapy and chemotherapy. A key player in the therapeutic resistance may be immature tumor cells with stem-like properties (TSCs) escaping conventional treatment. A group of promising molecular targets are microRNAs (miRs). miRs are small non-coding RNAs exerting post-transcriptional regulation of gene expression. In this study we aimed to identify over-expressed TSC-related miRs potentially amenable for therapeutic targeting. We used non-differentiated glioblastoma spheroid cultures (GSCs) containing TSCs and compared these to xenografts using a NanoString nCounter platform. This revealed 19 over-expressed miRs in the non-differentiated GSCs. Additionally, non-differentiated GSCs were compared to neural stem cells (NSCs) using a microarray platform. This revealed four significantly over-expressed miRs in the non-differentiated GSCs in comparison to the NSCs. The three most over-expressed miRs in the non-differentiated GSCs compared to xenografts were miR-126, -137 and -128. KEGG pathway analysis suggested the main biological function of these over-expressed miRs to be cell-cycle arrest and diminished proliferation. To functionally validate the profiling results suggesting association of these miRs with stem-like properties, experimental over-expression of miR-128 was performed. A consecutive limiting dilution assay confirmed a significantly elevated spheroid formation in the miR-128 over-expressing cells. This may provide potential therapeutic targets for anti-miRs to identify novel treatment options for GBM patients. [ABSTRACT FROM AUTHOR]

Context: It has been verified that dendritic cell (DC) vaccination can improve the prognosis of malignant glioma. However, recent evidence suggests the problems with DC vaccines lies, at least in part, with the cancers ability to induce an immunosupressive response that suppresses any vaccine-mediated active immunity. Our previous studies indicate that subcutaneous vaccine can restrain the cancer cells implanted in the brain, but the effect is limited on vascularized tumor in the brain. Furthermore, vascular endothelial growth factor (VEGF) and vascular cell adhesion molecule (VCAM) play an important role in immunoevasion.Aims: To identify the effects of DC vaccination on antiangiogenesis induced by endostatin in rat glioma.Materials and Methods: Rat basal ganglia glioma model was constructed and authenticated. The concentration of immunoglobulin G (IgG) was detected using rat IgG enzyme-linked immunosorbent assay (ELISA) kit. CD8+ T cell infiltration was measured by immunofluorescence. The expression of VEGF, VCAM, and intercellular adhesion molecule 1 (ICAM-1) tested by real-time reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot. The expression of VEGF and apoptosis in rat glioma tissues is tested by immunohistochemical staining.Statistical Analysis Used: Two group comparisons were analyzed by a two-tailed Student's t test. Multiple group comparisons were analyzed by one-way analysis of variance (ANOVA). P values less than 0.05 were considered statistically significant.Results: The combination of DC vaccination and antiangionesis inhibited the rats with malignant glioma by stimulating immune response, supressing the expression of angiogenesis-related proteins VEGF, VCAM, and ICAM-1. In addition, the combination therapy inhibited glioma stem-cell-like cells.Conclusions: DC vaccination enhances antiangiogenesis induced by endostatin in rat glioma. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to identify a prospective association between CA125 and tumorigenic ovarian cancer cells, using the new method of orthotopic transplantation (1). Method: After making the surgical ovarian cancer specimen into cell suspension, we separated the tumorigenic cells from the nontumorigenic cancer cells based on cell surface marker (cancer antigen CA125 and lineage markers) expression. We developed a SCID mice model in which the CA125+/lineage- and CA125-/lineage- cells were injected into ovarian parenchyma by use of a microinjector. As a measure of effectiveness of tumor-forming, tumor weight, abdominal distension, ascites volume and activity, subcutaneous fat were determined or observed. Immunohistochemistry was done to determine tumor cell markers. Results: We found that the cells of CA125+/lineage- were able to form new tumors; whereas, an equal quantity of CA125-/lineage- cells failed to form any tumors. The new generated tumor contained additional CA125-/lineage- tumorigenic cells as well as the phenotypically diverse population of nontumorigenic cells. Quantities were judged to be significantly different P < 0.0001. Conclusion: CA125+/lineage- cells, which may be ovarian cancer stem cells, were the source for tumor recurrence. The strategies designed to target this cell population may lead to more effective therapies. [ABSTRACT FROM AUTHOR]

Aging influences stem cells, but the processes involved remain unclear. Insulin signaling, which controls cellular nutrient sensing and organismal aging, regulates the G2 phase of Drosophila female germ line stem cell (GSC) division cycle in response to diet; furthermore, this signaling pathway is attenuated with age. The role of insulin signaling in GSCs as organisms age, however, is also unclear. Here, we report that aging results in the accumulation of tumorous GSCs, accompanied by a decline in GSC number and proliferation rate. Intriguingly, GSC loss with age is hastened by either accelerating (through eliminating expression of Myt1, a cell cycle inhibitory regulator) or delaying (through mutation of insulin receptor (dinR) GSC division, implying that disrupted cell cycle progression and insulin signaling contribute to age-dependent GSC loss. As flies age, DNA damage accumulates in GSCs, and the S phase of the GSC cell cycle is prolonged. In addition, GSC tumors (which escape the normal stem cell regulatory microenvironment, known as the niche) still respond to aging in a similar manner to normal GSCs, suggesting that niche signals are not required for GSCs to sense or respond to aging. Finally, we show that GSCs from mated and unmated females behave similarly, indicating that female GSC-male communication does not affect GSCs with age. Our results indicate the differential effects of aging and diet mediated by insulin signaling on the stem cell division cycle, highlight the complexity of the regulation of stem cell aging, and describe a link between ovarian cancer and aging. [ABSTRACT FROM AUTHOR]

Inflammatory pathways serve to protect the host and promote tissue healing/repair; however, over-activation or dysregulation can be pathological with unintended consequences including malignant progression. A correlation between inflammation and cancer has been well established, and anti-inflammatory medications have been shown to be chemopreventive in certain malignancies. Data are now becoming available that outline an inflammatory pathway that may have a critical role in melanomagenesis. ATP-regulated membrane channels/receptors P2 X7 and PANX1 have been directly implicated in melanoma tumor growth. Among other potential effects, opening of the P2 X7/ PANX1 channel results in activation of the NALP3 inflammasome, which in turn leads to caspase-1 activation and increased levels of activated IL-1 β. Elevated levels of caspase-1 and IL-1 β have been correlated with melanoma progression, and inhibitors of the inflammasome, caspase and IL-1 β activity have all been shown to inhibit melanoma growth. Among many other potential actions, IL-1 β increases cyclooxygenase-2 expression leading to local increases in inflammatory mediators such as prostaglandin E2 ( PGE2). Anti-inflammatory medications targeting the end of this pathway have had positive results for certain cancers but overall remain mixed for melanoma. A better understanding of the pathways and appropriate intervention points may help direct future therapies. In this viewpoint, we will review data and attempt to model an inflammatory pathway that may be critical for melanomagenesis and propose future directions for exploration. [ABSTRACT FROM AUTHOR]

Background Doublecortin-like kinase 1 (DCLK1) is emerging as a tumor specific stem cell marker in colorectal and pancreatic cancer. Previous in vitro and in vivo studies have demonstrated the therapeutic effects of inhibiting DCLK1 with small interfering RNA (siRNA) as well as genetically targeting the DCLK1+ cell for deletion. However, the effects of inhibiting DCLK1 kinase activity have not been studied directly. Therefore, we assessed the effects of inhibiting DCLK1 kinase activity using the novel small molecule kinase inhibitor, LRRK2-IN-1, which demonstrates significant affinity for DCLK1. Results Here we report that LRRK2-IN-1 demonstrates potent anti-cancer activity including inhibition of cancer cell proliferation, migration, and invasion as well as induction of apoptosis and cell cycle arrest. Additionally we found that it regulates stemness, epithelialmesenchymal transition, and oncogenic targets on the molecular level. Moreover, we show that LRRK2-IN-1 suppresses DCLK1 kinase activity and downstream DCLK1 effector c- MYC, and demonstrate that DCLK1 kinase activity is a significant factor in resistance to LRRK2-IN-1. Conclusions Given DCLK1's tumor stem cell marker status, a strong understanding of its biological role and interactions in gastrointestinal tumors may lead to discoveries that improve patient outcomes. The results of this study suggest that small molecule inhibitors of DCLK1 kinase should be further investigated as they may hold promise as anti-tumor stem cell drugs. [ABSTRACT FROM AUTHOR]

Embryonal tumor with abundant neuropil and true rosettes ( ETANTR) is a recently described embryonal neoplasm of the central nervous system, consisting of a well-circumscribed embryonal tumor of infancy with mixed features of ependymoblastoma (multilayer ependymoblastic rosettes and pseudorosettes) and neuroblastoma (neuroblastic rosettes) in the presence of neuropil-like islands. We present the case of a young child with a very aggressive tumor that rapidly recurred after gross total resection, chemotherapy and radiation. Prominent vascular sclerosis and circumscribed tumor led to the diagnosis of malignant astroblastoma; however, rapid recurrence and progression of this large tumor after gross total resection prompted review of the original pathology. ETANTR is histologically distinct with focal glial fibrillary acid protein ( GFAP) and synaptophysin expression in the presence of neuronal and ependymoblastic rosettes with focal neuropil islands. These architectural features, combined with unique chromosome 19q13.42 amplification, confirmed the diagnosis. In this report, we describe tumor stem cell ( TSC) marker CD133, CD15 and nestin alterations in ETANTR before and after chemotherapy. We found that TSC marker CD133 was richly expressed after chemotherapy in recurrent ETANTR, while CD15 is depleted compared with that expressed in the original tumor, suggesting that CD133+ cells likely survived initial treatment, further contributing to formation of the recurrent tumor. [ABSTRACT FROM AUTHOR]

In this study, we try to detect and isolate the cancer stem cell-like side population cells (SP) from the laryngeal carcinoma cell line and primary laryngeal carcinoma and explore the clinical implications of SP cells in laryngeal carcinoma. The SP cells and non-side population cells (NSP) cells were sorted by Hoechst 33342 through FACS. The proliferation capacity, invasion ability, migration ability, and tumorigenic activity of the SP cells were evaluated. In addition, the association between the SP cells ratio and the prognostic factors of laryngeal cancer was analyzed. As a result, the percentage of the SP cells in Hep-2 cells was 5.1 %. The SP cells depicted float colonies, but the NSP cells failed to generate the typical cell spheres. The clone formation ratios were 47.47 ± 10.20 % vs. 4.98 ± 1.41 % in the flat plates and 46.82 ± 5.67 % vs. 12.53 ± 3.51 % in the soft agar for SP and NSP cells ( P = 0.01 and 0.01). The SP cells depicted a higher migrating potency than the NSP cells in both the transwell assay and scarification test (all P < 0.05). The matrigel invasion assay showed that the artificial basement membrane penetration rate of SP cells was 39.04 ± 4.78 %, which was higher than 25.16 ± 4.63 % of the NSP cells ( P < 0.05). Only 10 3 SP cells were able to form tumors in mice, whereas 10 4 NSP cells failed to form tumors. The SP cells were correlated with the differentiation, lymph node metastasis, and clinical stage of the laryngeal cancers. In conclusion, SP cells may be a potential prognostic factor of laryngeal cancer. [ABSTRACT FROM AUTHOR]

Conclusions: The CD44+ cells have a stronger proliferative capacity and higher tumorigenic potential than the CD44- cells, which suggests that the cancer stem cells of hypopharyngeal cancer may exist in the CD44+ tumor cell population. Therefore, we propose that CD44 is an important biological marker to screen cancer stem cells of hypopharyngeal cancer. Objectives: To study the significance of CD44 as a molecular marker for screening cancer stem cells in hypopharyngeal cancer. Methods: The CD44 expression levels in the hypopharyngeal cancer cell line FaDu were analyzed using flow cytometry. To investigate the biological significance of the CD44+ population, we sorted the CD44+ and CD44- cell populations by using magnetic-associated cell sorting (MACS) technology. After the separation, the purity of the CD44+ cells was determined using flow cytometry. The MTT method was used to detect the different proliferation capabilities of the CD44+ and CD44- cells in vitro. The tumorigenicity of the CD44+ and CD44- cells was determined by injecting CD44+ or CD44- cells (1 × 106 and 1 × 105) into the body of NOD/SCID mice. Results: Some (21.1 ± 1.56)% of the hypopharyngeal cancer cell line FaDu cells expressed CD44. The CD44+ population was efficiently sorted by MACS, and after separation, the purity of the CD44+ cells was (99.4 ± 0.29)%. The MTT assay indicated that the sorted CD44+ cells had a stronger proliferative capacity than the CD44- cells. The tumorigenicity study showed that all the mice injected with 1 × 106 CD44+ cells developed tumors (8/8), half the mice injected with 1 × 106 CD44- cells developed tumors (4/8), 1 of the 8 mice injected with 1 × 105 CD44+ cells developed tumors (12.5%), but none of the mice injected with 1 × 105 CD44- cells developed any tumors (0/8). At the same concentration, the difference in tumorigenic rates between the CD44+ and CD44- groups was statistically significant (Fisher's exact test, p < 0.05). Furthermore, the CD44+ group had a shorter incubation period than the CD44- group. In addition, the average tumor volume of the CD44+ group was (2017.81 ± 538.50) mm3; however, the average tumor volume of the CD44- group was (1153.25 ± 503.18) mm3. The difference was statistically significant ( t = 2.67, p < 0.05). [ABSTRACT FROM AUTHOR]

Abstract: Since chemokines and their receptors play a pivotal role in tumors, we investigated the CXCL16–CXCR6-axis in human astroglial tumors. The transmembrane chemokine CXCL16 is heavily expressed by tumor, microglial and endothelial cells in situ and in vitro. In contrast, the receptor CXCR6 is restricted in glioblastomas to a small subset of proliferating cells positive for the stem-cell markers Musashi, Nanog, Sox2 and Oct4. In particular, the vast majority (about 90%) of Musashi-positive cells stained also for CXCR6. Thus, CXCL16 is highly expressed by glial tumor and stroma cells whereas CXCR6 defines a subset of cells with stem cell character. [Copyright &y& Elsevier]

Purpose: Metastases are a frequent finding in gastric cancer and are associated with poor prognosis. A recently discovered link between metabolic changes, differentiation, and therapy resistance due to tumor stem cells could depict a novel approach in cancer research and therapy. Phosphoglycerate kinase 1 (PGK1) is a metabolic enzyme and is known to be involved in enabling gastric cancer cells to be invasive and to disseminate. In this study, we investigated if PGK1 is a promising candidate in inducing stem cell differentiation in gastric cancer. Materials and methods: MKN45 gastric cancer cells were used due to their known cancer stem cell population, which is defined by the surface marker CD44. MKN45 cells were separated between CD44+ and CD44− cells and, in equal parts, incubated with shRNA anti-PGK1 using fluorescence-activated cell sorting (FACS) analysis; they were then injected into nude mice to evaluate their tumor growth behavior in vivo. Further, the invasive potential of gastric cancer cells was evaluated in vitro using the xCelligence analyzing system. Results: CD44+ gastric cancer cells treated with and without shRNA anti-PGK1 were capable to cause tumor growth in vivo, whereas tumor growth in CD44+ cells treated with shRNA anti-PGK1 was considerably smaller in comparison with that in CD44+ cells without treatment. CD44− cells did not show any noticeable tumor growth in vivo. By targeting PGK1, the invasive potential of gastric cancer cells was impressively reduced in vitro. In all our cells, which were targeted with shRNA anti-PGK1, we did not find any change that is in accordance with the phenotype of the cells using FACS analysis. Conclusions: Our findings suggest that targeting the key metabolic enzyme PGK1 in gastric cancer cells may open a new chapter in cancer treatment, which is well worth for further exploration in combination with recent chemotherapy, and might be a promising possibility to overcome therapy resistance in gastric cancer. [ABSTRACT FROM AUTHOR]

Abstract: Aldehyde dehydrogenase 1 (ALDH1), a detoxifying enzyme, is a stem-like cell marker, but its expression pattern and clinical significance in astrocytoma remain unclear. In this study, we used immunohistochemical analysis to systematically investigate the expression of ALDH1 in 76 astrocytomas of different pathological grade and seven samples of normal brain tissues. We found that ALDH1 was expressed in some of the astrocytomas but was not detected in normal brain tissues. The proportion of ALDH1-expressing cells was positively correlated with the pathological grade of the astrocytomas, but not with patient age, sex or tumor size. We also collected detailed follow-up data and analyzed the correlation of ALDH1 expression with overall survival (OS) and progression-free survival (PFS) using univariate and multivariate analysis. We found that the proportion of ALDH1-positive cells was an independent prognostic factor for PFS and OS. These results show that ALDH1 is expressed in astrocytoma, and that its expression is correlated with pathological grade and patient survival. [Copyright &y& Elsevier]

Objective To screen the differentially expressed genes of stem-like cells in tongue squamous cell carcinoma using suppression subtractive hybridization(SSH). Methods The cells with high and low expression of aldehyde dehydrogenase(ALDHhr and ALDHlow) were isolated respectively from human tongue squamous cell carcinoma Tca8113 cell line. SSH was used to identify differentially expressed genes in those two groups. Positive cell clones with high! low-expressed ALDH were screened randomly for the genetic sequences and function analysis by the bioinformatics technology. Results Total 62 differentially expressed genes were identified, most of which got involved in regulation of cell cycle, cellular differentiation and other biology activities as gene ontology (GO) analysis indicated. Signal pathway analysis revealed 12 pathways related to 11 genes changed significantly. Conclusion Several potential novel biomarker candidates of tongue cancer stem cells were identified and they may provide important insights into the functions and characteristics of human tumor stem cell. [ABSTRACT FROM AUTHOR]

Embryonic stem cell (ESC) markers are molecules specifically expressed in ES cells. Understanding of the functions of these markers is critical for characterization and elucidation for the mechanism of ESC pluripotent maintenance and self-renewal, therefore helping to accelerate the clinical application of ES cells. Unfortunately, different cell types can share single or sometimes multiple markers; thus the main obstacle in the clinical application of ESC is to purify ES cells from other types of cells, especially tumor cells. Currently, the marker-based flow cytometry (FCM) technique and magnetic cell sorting (MACS) are the most effective cell isolating methods, and a detailed maker list will help to initially identify, as well as isolate ESCs using these methods. In the current review, we discuss a wide range of cell surface and generic molecular markers that are indicative of the undifferentiated ESCs. Other types of molecules, such as lectins and peptides, which bind to ESC via affinity and specificity, are also summarized. In addition, we review several markers that overlap with tumor stem cells (TSCs), which suggest that uncertainty still exists regarding the benefits of using these markers alone or in various combinations when identifying and isolating cells. [ABSTRACT FROM AUTHOR]

Stem-like cells in tumors are capable of self-renewal and pluri-differentiation; they are thought to play important roles in tumor initiation and maintenance. Stem-like cells in malignant glioma express CD133. We examined samples from human pituitary adenoma, a generally benign neoplasm, for CD133 expression using routine immunohistochemical and biochemical methods. Our study of 70 pituitary adenomas (clinically nonfunctioning adenomas and growth hormone-, prolactin-, adrenocorticotropic hormone-, and thyroid-stimulating hormone-producing adenomas) showed that 18 (25.7%) expressed CD133. This rate was higher in clinically nonfunctioning (33.3%) than functioning adenomas (12.0%) (p = 0.085). Real-time PCR assay revealed the expression of CD133 mRNA in samples immunohistochemically positive for CD133. Neither the patient age and gender, nor the tumor size or postoperative recurrence rate correlated with CD133 positivity. CD133+ cells ubiquitously coexpressed CD34, nestin, and VEGFR2 (KDL1). S-100 and GFAP were not coexpressed with CD133. Chromogranin A, Pit-1, SF-1, and NeuroD1 were immune-negative, indicating that CD133+ cells did not have the potential to differentiate into functional endocrine cells. Our data suggest that the expression of CD133 in pituitary adenomas is related to immature endothelial progenitor cells that may play a role in the neovascularization of pituitary adenomas. Further studies are needed to elucidate the significance of CD133+ cells with respect to neovascularization and their sustainable growth in pituitary adenomas. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Osteosarcoma is the most common primary bone tumor in children and adolescents and is typically associated with a poor prognosis. Tumor stem cells (TSCs) are presumed to drive tumor initiation and tumor relapse or metastasis. Hence, the poor prognosis of osteosarcoma likely results from a failure to target the osteosarcoma stem cells. Here, we have utilized three different methods to enrich TSCs in osteosarcoma and further evaluated whether salinomycin could selectively target TSCs in osteosarcoma. Our results indicated that sarcosphere selection, chemotherapy selection and stem cell marker OCT4 or SOX2 over-expression are all effective in the enrichment of TSCs from osteosarcoma cell lines. Further investigation found that salinomycin inhibited osteosarcoma by selectively targeting its stem cells both in vitro and in vivo without severe side effects, and the Wnt/β-catenin signaling pathway may be involved in this inhibition of salinomycin. Taken together, we have identified that salinomycin is an effective inhibitor of osteosarcoma stem cells, supporting the use of salinomycin for elimination of osteosarcoma stem cells and implying a need for further clinical evaluation. [Copyright &y& Elsevier]

Magnetic resonance imaging (MRI) is the imaging modality of choice by which to monitor patient gliomas and treatment effects, and has been applied to murine models of glioma. However, a major obstacle to the development of effective glioma therapeutics has been that widely used animal models of glioma have not accurately recapitulated the morphological heterogeneity and invasive nature of this very lethal human cancer. This deficiency is being alleviated somewhat as more representative models are being developed, but there is still a clear need for relevant yet practical models that are well-characterized in terms of their MRI features. Hence we sought to chronicle the MRI profile of a recently developed, comparatively straightforward human tumor stem cell (hTSC) derived glioma model in mice using conventional MRI methods. This model reproduces the salient features of gliomas in humans, including florid neoangiogenesis and aggressive invasion of normal brain. Accordingly, the variable, invasive morphology of hTSC gliomas visualized on MRI duplicated that seen in patients, and it differed considerably from the widely used U87 glioma model that does not invade normal brain. After several weeks of tumor growth the hTSC model exhibited an MRI contrast enhancing phenotype having variable intensity and an irregular shape, which mimicked the heterogeneous appearance observed with human glioma patients. The MRI findings reported here support the use of the hTSC glioma xenograft model combined with MRI, as a test platform for assessing candidate therapeutics for glioma, and for developing novel MR methods. [ABSTRACT FROM AUTHOR]

Malignant gliomas are highly lethal because of their resistance to conventional treatments. Recent evidence suggests that a minor subpopulation of cells with stem cell properties reside within these tumors. These tumor stem cells are more resistant to radiation and chemotherapies than their counterpart differentiated tumor cells and may underlie the persistence and recurrence of tumors following treatment. The various mechanisms by which tumor stem cells avoid or repair the damaging effects of cancer therapies are discussed. [ABSTRACT FROM AUTHOR]

Abstract: IGFBP2 is overexpressed in the most common brain tumor, glioblastoma (GBM), and its expression is inversely correlated to GBM patient survival. Previous reports have demonstrated a role for IGFBP2 in glioma cell invasion and astrocytoma development. However, the function of IGFBP2 in the restricted, self-renewing, and tumorigenic GBM cell population comprised of tumor-initiating stem cells has yet to be determined. Herein we demonstrate that IGFBP2 is overexpressed within the stem cell compartment of GBMs and is integral for the clonal expansion and proliferative properties of glioma stem cells (GSCs). In addition, IGFBP2 inhibition reduced Akt-dependent GSC genotoxic and drug resistance. These results suggest that IGFBP2 is a selective malignant factor that may contribute significantly to GBM pathogenesis by enriching for GSCs and mediating their survival. Given the current dearth of selective molecular targets against GSCs, we anticipate our results to be of high therapeutic relevance in combating the rapid and lethal course of GBM. [Copyright &y& Elsevier]