Presence Of Cancer Stem Cells Research Articles

Analysis of Clinical Success and Molecular Mechanisms of Action of Novel Anti-glioblastoma Drugs: A Review.

Gliomas and glioblastomas (GBM) are common primary malignant brain tumors, which are highly malignant and have a poor prognosis. The presence of cancer stem cells with unrestricted proliferative capacity and ability to generate glial neoplastic cells, the diffuse nature of GBM, and other specific factors of GBM contribute to poor results of drug therapy in patients with GBM. Despite the worldwide efforts to improve the treatment, many novel anti-GBM drugs are active just in vitro, in silico, and in preclinical trials, and they sometimes demonstrate poor or no activity in clinical trials. In this paper, we have casually selected and analyzed the most promising evidence-based results related to glioblastoma treatment at FDA and Clinical Trials.gov databases. It was observed that the most prospective trend in the development of anti-GBM drugs is combination therapy vs. monotherapy. Our analysis of clinical trials has allowed us to predict that the most promising combination therapy that has shown the best results in patient's surveillance should include drugs that block different growth-promoting signals in glioblastoma cells and that are activated by the V600E BRAF mutation. One drug should inhibit signals from the BRAF protein, whereas the second drug in combination should inhibit signals from the MEK protein Methods: The content of this review is based on information obtained from PubMed, ClinicalTrials. gov, and the U.S. Food and Drug Administration (https://www.fda.gov/). In ClinicalTrials.gov, we retrieved studies published from January 1, 2015. In the data search, "Glioblastoma" was used as the keyword. A study was deleted if it studied remedies for concomitant tumor diseases, as well as if it did not include descriptions of treatment methods and/or if GBM was not mentioned. The analysis of the effectiveness of treatment was carried out according to the increasing overall survival in GBM patients, compared to the gold standard for this cancer. GBM patients treated with novel immunotherapy agents and drugs acting on epigenetic factors and receptor tyrosine kinase inhibitors have shown encouraging potential for future development in clinic. However, combinations of drugs have led to more significant improvements in the results and an increase in life expectancy of patients. For example, the combination of nivolumab and ipilimumab showed a 72% increase in life expectancy compared to using nivolumab alone (9.8 vs. 16.85). Combining anti-GBM drugs appears to be a key direction for increasing treatment effectiveness and overall survival. Radiotherapy of GBM can increase the effect of combination drug therapy.

Significant Association of PD‐L1 With CD44 Expression and Patient Survival: Avenues for Immunotherapy and Cancer Stem Cells Downregulation in Pancreatic Cancers

Background: Pancreatic cancers are known for their aggressive nature. This aggressiveness may be attributed to the presence of cancer stem cells (CSCs), which promote relapse, metastasis, and resistance to chemotherapy. Targeting CSCs is essential to reverse this aggressiveness in pancreatic malignancies. Literature highlights the association of PD‐L1 expression with CSCs in various cancers, suggesting immunotherapy as a promising therapeutic approach. This study is aimed at investigating the potential of immunotherapy in pancreatic cancers by examining its association with selected CSC marker expression.Method: A retrospective cohort study was conducted involving 56 patients with confirmed diagnoses of pancreatic cancers at Aga Khan University Hospital from January 2015 to October 2022. After exclusions, based on refusal to provide consent or incomplete follow‐up data, 38 patients were enrolled in the study. Immunohistochemistry was performed on formalin‐fixed paraffin‐embedded (FFPE) tumor tissue samples to assess the expression of CSC markers (CD133, CD44, and L1CAM) and immune checkpoint inhibitor marker (PD‐L1). Statistical analysis was employed to determine associations between marker expression, clinical factors, and overall survival.Results: The study revealed that 86.8% of pancreatic cancer cases exhibited positive PD‐L1 expression. Moreover, a significant association of PD‐L1 expression was observed with the presence of CD44 protein (p = 0.030), as well as with the overall survival of patients (p = 0.023).Conclusion: Our findings show a significant association of PD‐L1 with CD44 marker expression as well as patient survival. This research shows the potential to serve as the foundation for investigating the efficacy of immunotherapy in reducing CD44‐expressing CSCs in pancreatic cancer, potentially enhancing patient outcomes.

Chemotherapy Resistance in Cancer: Mechanism and Roadmap to Evade Exploring Apoptosis

Chemotherapy resistance indicates the non-responsiveness of cancer cells to the cytotoxic and inhibitory effects of chemo drugs attributed to either intrinsic or extrinsic resistance mechanisms in cancer cells. Studies so far indicate that drug resistance can be triggered by a multitude of factors such as the over-expression of drug efflux pumps, DNA repair mechanisms, modifications in the drug target such as point mutations and gene amplification, over-expression of anti-apoptotic proteins and down-regulation of pro-apoptotic signals, presence of cancer stem cells and immune-suppressive cells, excessive cytokine production, tumor heterogeneity, epigenetic changes, activation of alternate pro-survival signaling pathways, etc. Both host and tumor-related factors can contribute to therapy resistance. Currently, chemo resistance poses the foremost setback in the successful treatment of cancer, and it exerts significant stress on the available medical resources. Besides the costs associated with the treatment, patients go through severe emotional and physical trauma. Chemotherapy resistance is also a major contributor to accelerated metastasis and invasion. Dose-escalation is not always practical since the associated side effects may increase apart from increasing the treatment costs. Several studies are ongoing to address this issue productively, such as therapeutic molecules designed to restore the apoptotic machinery. Site-specific delivery of pro-apoptotic agents such as small molecules, antibodies, peptides, etc. targeting the apoptosis pathway is also thoroughly studied. Moreover, the efficacy of combination strategies is also a topic of research.

Molecular and Cellular Expressions in Breast Cancer Responsible for Drug Resistance

Breast cancer continues to be a prevalent and highly lethal cancer affecting women globally. Despite significant advancements in early detection and the development of specific therapeutic approaches, the issue of medication resistance remains a prominent challenge in managing this intricate ailment. The study offers a comprehensive analysis of the mechanisms behind the development of treatment resistance in breast cancer cells. The objective of this study is to provide a comprehensive understanding of the molecular and cellular mechanisms behind the occurrence of therapeutic ineffectiveness. This study elucidates several molecular subtypes of breast cancer and their pharmacological responses. The significance of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in the development of treatment resistance is emphasized. Additional research on the intricacies of innate and acquired drug resistance mechanisms, including genetic modifications, tumor heterogeneity, and the presence of cancer stem cells, has shed light on the multifaceted nature of drug resistance and its dynamic evolution throughout treatment. Furthermore, this study provides a comprehensive analysis of the impact of microenvironmental variables, including hypoxia, immune evasion, and tumor-stroma connections, on the development of drug resistance. The investigation of the interplay between tumor suppressors and oncogenes in the emergence of drug resistance is now underway, yielding valuable insights into prospective targets for therapeutic intervention. Additionally, this study examines the limitations associated with conventional chemotherapy, endocrine therapies, and targeted medicines, while elucidating the mechanisms underlying treatment resistance and proposing potential strategies to overcome it. Emerging therapies like immunotherapies, epigenetic modulators, and new drug delivery methods are looked at to see if they have the potential to get around mechanisms of resistance and improve patient outcomes. This review aims to give clinicians, researchers, and other healthcare workers a full picture of breast cancer’s complex drug resistance mechanisms. By figuring out the molecular complexities and signaling pathways that lead to treatment resistance, we aim to speed up the development of new therapeutic approaches and personalized interventions. This will bring us closer to the long-awaited goal of beating drug resistance and making breast cancer a manageable, treatable condition.

Regulation of cancer stem cells and immunotherapy of glioblastoma (Review).

Glioblastoma (GB) is one of the most adverse diagnoses in oncology. Complex current treatment results in a median survival of 15 months. Resistance to treatment is associated with the presence of cancer stem cells (CSCs). The present review aimed to analyze the mechanisms of CSC plasticity, showing the particular role of β-catenin in regulating vital functions of CSCs, and to describe the molecular mechanisms of Wnt-independent increase of β-catenin levels, which is influenced by the local microenvironment of CSCs. The present review also analyzed the reasons for the low effectiveness of using medication in the regulation of CSCs, and proposed the development of immunotherapy scenarios with tumor cell vaccines, containing heterogenous cancer cells able of producing a multidirectional antineoplastic immune response. Additionally, the possibility of managing lymphopenia by transplanting hematopoietic stem cells from a healthy sibling and using clofazimine or other repurposed drugs that reduce β-catenin concentration in CSCs was discussed in the present study.

SOX2 promotes a cancer stem cell-like phenotype and local spreading in oral squamous cell carcinoma

Emerging evidence shows that oral squamous cell carcinoma (OSCC) invasiveness can be attributed to a small subpopulation of cancer stem cells (CSCs) in the bulk of the tumor. However, the presence of CSCs in the OSCC close resection margins is still poorly unexplored. Here, we found that BMI1, CD44, SOX2, OCT4, UBE2C, CXCR4 CSCs marker genes are significantly upregulated, while IGF1-R, KLF4, ALDH1A1, CD133, FAM3C are downregulated in the tumor core vs healthy mucosa of 24 patients with OSCC. Among these, SOX2 appears also upregulated in the tumor close margin vs healthy mucosa and this significantly correlates with tumor size and lymph node compromise. In vitro analyses in CAL27 and SCC15 tongue squamous cell carcinoma cell lines, show that SOX2 transient knockdown i) promotes the mesenchymal-to-epithelial transition, ii) smooths the invasiveness, iii) attenuates the 3D tumor sphere-forming capacity, and iv) partially increases the sensitivity to cisplatin treatment. Overall, our study highlights that the OSCC close margins can retain CSC-specific markers. Notably, SOX2 may represent a useful CSCs marker to predict a more aggressive phenotype and a suitable target to prevent local invasiveness.

Visualizing cancer-originating acetate uptake through monocarboxylate transporter 1 in reactive astrocytes in the glioblastoma tumor microenvironment.

Reactive astrogliosis is a hallmark of various brain pathologies, including neurodegenerative diseases and glioblastomas. However, the specific intermediate metabolites contributing to reactive astrogliosis remain unknown. This study investigated how glioblastomas induce reactive astrogliosis in the neighboring microenvironment and explore 11C-acetate PET as an imaging technique for detecting reactive astrogliosis. Through in vitro, mouse models, and human tissue experiments, we examined the association between elevated 11C-acetate uptake and reactive astrogliosis in gliomas. We explored acetate from glioblastoma cells, which triggers reactive astrogliosis in neighboring astrocytes by upregulating MAO-B and monocarboxylate transporter 1 (MCT1) expression. We evaluated the presence of cancer stem cells in the reactive astrogliosis region of glioblastomas and assessed the correlation between the volume of 11C-acetate uptake beyond MRI and prognosis. Elevated 11C-acetate uptake is associated with reactive astrogliosis and astrocytic MCT1 in the periphery of glioblastomas in human tissues and mouse models. Glioblastoma cells exhibit increased acetate production as a result of glucose metabolism, with subsequent secretion of acetate. Acetate derived from glioblastoma cells induces reactive astrogliosis in neighboring astrocytes by increasing the expression of MAO-B and MCT1. We found cancer stem cells within the reactive astrogliosis at the tumor periphery. Consequently, a larger volume of 11C-acetate uptake beyond contrast-enhanced MRI was associated with a worse prognosis. Our results highlight the role of acetate derived from glioblastoma cells in inducing reactive astrogliosis and underscore the potential value of 11C-acetate PET as an imaging technique for detecting reactive astrogliosis, offering important implications for the diagnosis and treatment of glioblastomas.

Quantitative Modeling of Stemness in Single-Cell RNA Sequencing Data: A Nonlinear One-Class Support Vector Machine Method.

Intratumoral heterogeneity and the presence of cancer stem cells are challenging issues in cancer therapy. An appropriate quantification of the stemness of individual cells for assessing the potential for self-renewal and differentiation from the cell of origin can define a measurement for quantifying different cell states, which is important in understanding the dynamics of cancer evolution, and might further provide possible targeted therapies aimed at tumor stem cells. Nevertheless, it is usually difficult to quantify the stemness of a cell based on molecular information associated with the cell. In this study, we proposed a stemness definition method with one-class Hadamard kernel support vector machine (OCHSVM) based on single-cell RNA sequencing (scRNA-seq) data. Applications of the proposed OCHSVM stemness are assessed by various data sets, including preimplantation embryo cells, induced pluripotent stem cells, or tumor cells. We further compared the OCHSVM model with state-of-the-art methods CytoTRACE, one-class logistic regression, or one-class SVM methods with different kernels. The computational results demonstrate that the OCHSVM method is more suitable for stemness identification using scRNA-seq data.

Talazoparib enhances the quinacrine-mediated apoptosis in patient-derived oral mucosa CSCs by inhibiting BER pathway through the modulation of GCN5 and P300.

The presence of cancer stem cells (CSCs) in the tumor microenvironment (TME) is majorly responsible for the development and recurrence of cancer. Earlier reports suggested that upon DNA damage, poly-(ADP-ribose) polymerase-1 (PARP-1) helps in chromatin modulation and DNA repair process, thereby promoting CSC survival. But whether a combination of DNA damaging agents along with PARP inhibitors can modulate chromatin assembly, inhibit DNA repair processes, and subsequently target CSCs is not known. Hence, we have investigated the effect of nontoxic bioactive compound quinacrine (QC) and a potent PARP inhibitor Talazoparib in patient-derived oral mucosa CSCs (OM-CSCs) and in vivo xenograft mice preclinical model systems. Data showed that QC + Talazoparib inhibited the PARP-1-mediated chromatin remodelers' recruitment and deregulated HAT activity of GCN5 (general control nonderepressible-5) and P300 at DNA damage site, thereby preventing the access of repair proteins to the damaged DNA. Additionally, this combination treatment inhibited topoisomerase activity, induced topological stress, and induced apoptosis in OM-CSCs. Similar results were observed in an in vivo xenograft mice model system. Collectively, the data suggested that QC + Talazoparib treatment inhibited BER pathway, induced genomic instability and triggered apoptosis in OM-CSCs through the deregulation of PARP-1-mediated chromatin remodelers (GCN5 and P300) activity. Schematic representation of QC + Talazoparib-induced apoptosis in oral mucosa CSCs. (1) Induction of DNA damage takes place after QC treatment (2) PARP1-mediated PARylation at the site of DNA damage, which recruits multiple chromatin remodelers (3) Acetylation at the histone tails relax the structure of chromatin and recruits the BER pathway proteins at the site of DNA damage. (4) BER pathway activated at the site of DNA damage. (5) CSCs survive after successful repair of DNA damage. (6) Treatment of QC-treated CSCs with PARP inhibitor Talazoparib (7) Inhibition of PARylation results in failure of chromatin remodelers to interact with PARP1. (8) Inhibition of acetylation status leads to chromatin compaction. (9) BER pathway proteins are not recruited at the site of DNA damage, resulting in inhibition of BER pathway and accumulation of unrepaired DNA damage, leading to apoptosis and cell death.

Immunohistochemistry expression of stem cell markers SOX2, OCT4, CD133 in different grades of meningiomas and correlation with Ki 67 index

BackgroundThere is accumulating evidence of the presence of Cancer Stem Cells (CSCs) within meningiomas (MGs). In the present study, we assessed the Immunohistochemistry (IHC) expression of stem cell markers SOX2, OCT4, CD133 in different grades of MGs and their correlation with Ki 67 index. MethodsA cross-sectional analytical study where 140 MGs cases were graded and classified according to WHO-2021 classification. IHC for SOX2, OCT4, CD133 and Ki-67 was carried out. ResultsOut of 140 cases, 59 cases (42.1%) showed OCT4 positivity, 38 cases (27.1%) showed CD133 positivity and only 21 cases (15%) showed SOX2 positivity. Ki 67 index ranged from 1-30%. Statistically significant difference (Chi Square p-value <0.001) was found between SOX 2, OCT4 and CD133 expressions (positive/negative) and the grades of MG cases. As the grades of MG cases increased, the positive expression of SOX2, OCT 4 and CD 133 also increased. The Mean Ki 67 index value was significantly raised when SOX2, OCT 4 and CD 133 IHC expressions were positive (Student t Test p-value <0.001). ConclusionOur results strongly support the hypothesis of presence of CSCs, in MGs regardless of their grade. We recommend that CSCs IHC markers (SOX2, OCT4 and CD133) to be used on initial diagnosis in all cases of MGs along with Ki-67 index. It can help quantitate CSCs and in turn, recommend closer follow up in patients with high percentage of CSCs to predict early recurrence.

Revolutionizing colorectal cancer treatment: unleashing the potential of miRNAs in targeting cancer stem cells.

Colorectal cancer (CRC) is a significant contributor to cancer mortality worldwide, and the presence of cancer stem cells (CSC) represents a major challenge for achieving effective treatment. miRNAs have emerged as critical regulators of gene expression, and recent studies have highlighted their role in regulating stemness and therapeutic resistance in CRC stem cells. This review highlights the mechanisms of CSC development, therapy resistance and the potential of miRNAs as therapeutic targets for CRC. It emphasizes the promise of miRNAs as a novel approach to CRC treatment and calls for further research to explore effective miRNA-based therapies and strategies for delivering miRNAs to CSCs in vivo.

Prognostic evaluation of tumour budding in oral squamous cell carcinoma: Evidenced by CD44 expression as a cancer stem cell marker

ObjectivesTumor budding is a sign of invasion and early step for metastasis of many cancers including oral squamous cell carcinoma (OSCC). Evidences suggest the presence of cancer stem cells in tumor buds. CD44 has been reported in tumor growth and metastasis as a cancer stem cell marker in OSCC. The study aims to highlight the prognostic significance of tumor budding in association with CD44 expression as a cancer stem cell marker in OSCC. MethodsA total of 60 radical neck dissection specimens of OSCC with and without lymph node metastasis were included in the study. The sections were evaluated for TB [Tumor Budding] in H&E and CD44 expression immunohistochemically. OSCC cases were then correlated with clinicopathologic and histomorphologic parameters such as age, gender, habit, site, staging, grading, recurrence, depth of invasion, pattern of invasion, and survival outcomes. Comparison of prognosis and CD44 expression were carried out by statistical methods. ResultsA high TB score was significantly correlated with grading (p = 0.037), POI [Pattern of invasion] (0.029), overall survival (p = 0.047). CD44 over expression showed strong correlations with POI (1HPF:p = 0.037;10HPF:p = 0.027), grading (p = 0.037), and overall survival (p = 0.047). Kaplan-Meier analysis revealed overall survival advantage for LTB [Low TB] (85 %) with OSCC compare to HTB [High TB] (75 %) for > 36 months. ConclusionAssessment of TB is effective in predicting prognosis of OSCC. Although CD44 expression has demonstrated strong prognostic influence, there were significant differences in its expression with the parameters.

Oxaliplatin Enhances the Apoptotic Effect of Mesenchymal Stem Cells, Delivering Soluble TRAIL in Chemoresistant Colorectal Cancer.

A key problem in colorectal cancer (CRC) is the development of resistance to current therapies due to the presence of cancer stem cells (CSC), which leads to poor prognosis. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a protein that activates apoptosis in cancer cells through union with TRAIL death receptors. Cell therapies as delivery systems can produce soluble TRAIL (sTRAIL) and full-length TRAIL (flTRAIL), showing a high capacity to produce apoptosis in vitro and in vivo assays. However, the apoptotic activity of TRAIL as monotherapy had limitations, so it is important to explore other ways to enhance susceptibility to TRAIL. This study evaluated the cytotoxic and proapoptotic activity of soluble TRAIL overexpressed by mesenchymal stem cells (MSC) in an oxaliplatin-resistant CRC cell line. Bone marrow-MSC were lentiviral transduced for soluble TRAIL expression. DR5 death receptor expression was determined in Caco-2 and CMT-93 CRC cell lines. Sensitivity to first-line chemotherapies and recombinant TRAIL was evaluated by half-maximal inhibitory concentrations. Cytotoxic and proapoptotic activity of soluble TRAIL-MSC alone and combined with chemotherapy pre-treatment was evaluated using co-cultures. Caco-2 and CMT-93 cell lines expressed 59.08 ± 5.071 and 51.65 ± 11.99 of DR5 receptor and had IC50 of 534.15 ng/mL and 581.34 ng/mL for recombinant murine TRAIL (rmTRAIL), respectively. This finding was classified as moderate resistance to TRAIL. The Caco-2 cell line showed resistance to oxaliplatin and irinotecan. MSC successfully overexpressed soluble TRAIL and induced cancer cell death at a 1:6 ratio in co-culture. Oxaliplatin pre-treatment in the Caco-2 cell line increased the cell death percentage (50%) and apoptosis by sTRAIL. This finding was statistically different from the negative control (p < 0.05), and activity was even higher with the oxaliplatin-flTRAIL combination. Thus, oxaliplatin increases apoptotic activity induced by soluble TRAIL in a chemoresistant CRC cell line.

Pancreatic Cancer Derived 3-D Organoids as Clinical Tool to Predict Response to Radiation and Chemo-Radiation Therapy

Pancreatic cancer (PC) is the fourth leading cause of cancer death in both men and women. The standard of care for patients with locally advanced PC of chemotherapy, stereotactic radiotherapy (RT) or chemo-radiation-therapy has shown highly variable and limited success rates. However, three-dimensional (3D) Pancreatic tumor organoids (PTOs) have shown promise to study tumor response to drugs, and emerging treatments under in vitro conditions. We investigated the potential for using 3D organoids to evaluate the precise radiation and drug dose responses of in vivo PC tumors. PTOs were created from mouse pancreatic tumor tissues, and their microenvironment was compared to that of in vivo tumors using immunohistochemical staining. The organoids and in vivo PC tumors were treated with fractionated X-ray RT, 3-bromopyruvate (3BP) anti-tumor drug, and with a combination of 3BP + fractionated RT. We quantified treatment response by metabolic imaging and immunofluorescence of αSMA and vimentin markers. Pancreatic tumor organoids (PTOs) exhibited a similar fibrotic microenvironment and molecular response (as seen by apoptosis biomarker expression) as in vivo tumors. Untreated tumor organoids and in vivo tumor both exhibited proliferative growth of 6 folds the original size after 10 days, whereas no growth was seen for organoids and in vivo tumors treated with 8 (Gray) Gy of fractionated RT. Tumor organoids showed reduced growth rates of 3.2x and 1.8x when treated with 4 and 6 Gy fractionated RT, respectively. Interestingly, combination of 100 µM of 3BP + 4 Gy of RT showed pronounced growth inhibition as compared to 3-BP alone or 4 Gy of radiation alone. Further, we observed overexpression of OCT-4, SOX2, Nanog cancer stem cell markers (CSC) indicated presence of cancer stem cells in tumor organoids which might have some role in resistance to therapies and recurrence in pancreatic cancer. PTOs produced a similar microenvironment and exhibited similar growth characteristics as in vivo tumors following treatment, indicating their potential for predicting in vivo tumor sensitivity and response to RT and combined chemo-RT treatments. Cancer stem cells in pancreatic cancer could be playing a role in resistance to therapies and recurrence in pancreatic cancer.

A redox-responsive nanosystem to suppress chemoresistant lung cancer through targeting STAT3

Cancer stem cells (CSCs) have been demonstrated to be involved in tumor initiation and relapse, and the presence of CSCs in the tumor tissue often leads to therapeutic failure. BBI608 has been identified to eliminate CSCs by inhibiting signal transducer and activator of transcription 3 (STAT3). In this study, we confirm that BBI608 can efficiently suppress the proliferation and migration of non-small cell lung cancer (NSCLC) cells, and specifically kill the stemness-high population in chemoresistant NSCLC cells. To improve its bioavailability and tumor accumulation, BBI608 is successfully encapsulated into redox-responsive PEGylated branched N-(2-hydroxypropyl) methacrylamide (HPMA)-deoxy cholic acid (DA) polymeric nanoparticles (BBI608-SS-NPs). The BBI608-SS-NPs can release the drug in response to high concentrations of intracellular glutathione, and exhibit cytotoxicity against lung cancer cells and CSCs comparable to the free drug BBI608. Furthermore, the BBI608-SS-NPs preferentially accumulate in tumor sites, resulting in a superior anti-tumor efficacy in both cisplatin-resistant cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) models of NSCLC. Mechanistic studies demonstrate that BBI608-SS-NPs not only directly inhibit the downstream genes of the STAT3 pathway, but also indirectly inhibit the Wnt pathway. Overall, this stimuli-responsive polymeric nanoformulation of BBI608 shows great potential in the treatment of chemoresistant NSCLC by targeting CSCs.

BEX1 supports the stemness of hepatoblastoma by facilitating Warburg effect in a PPARγ/PDK1 dependent manner.

Hepatoblastoma (HB) is a highly aggressive paediatric malignancy that exhibits a high presence of cancer stem cells (CSCs), which related to tumour recurrence and chemotherapy resistance. Brain expressed X-linked protein 1 (BEX1) plays a pivotal role in ciliogenesis, axon regeneration and differentiation of neural stem cells. However, the role of BEX1 in metabolic and stemness programs in HB remains unclear. BEX1 expression in human and mouse HB was analyzed using gene expression profile data from NCBI GEO and immunohistochemical validation. Seahorse extracellular flux analyzer, ultra-high-performance liquid-chromatography mass spectrometry (LC-MS), flow cytometry, qRT-PCR, Western Blot, sphere formation assay, and diluted xenograft tumour formation assay were used to analyze metabolic and stemness features. Our results indicated that overexpression of BEX1 significantly enhanced the Warburg effect in HB cells. Furthermore, glycolysis inhibition largely attenuated the effects of BEX1 on HB cell growth and self-renewal, suggesting that BEX1 promotes stemness maintenance of HB cells by regulating the Warburg effect. Mechanistically, BEX1 enhances Warburg effect through the downregulation of peroxisome proliferator-activated receptor-gamma (PPARγ). Furthermore, pyruvate dehydrogenase kinase isozyme 1 (PDK1) is required for PPARγ-induced inhibition of Warburg effect in HB. In addition, BEX1 supports the stemness of HB by enhancing Warburg effect in a PPARγ/PDK1 dependent manner. HB patients with high BEX1 and PDK1 expression had a poor prognosis. BEX1 promotes the stemness maintenance of HB cells via modulating the Warburg effect, which depends on PPARγ/PDK1 axis. Pioglitazone could be used to target BEX1-mediated stemness properties in HB by upregulating PPARγ.

Biomimetic biomineralization nanoplatform-mediated differentiation therapy and phototherapy for cancer stem cell inhibition and antitumor immunity activation

Growing evidence suggests that the presence of cancer stem cells (CSCs) is a major challenge in current tumor treatments, especially the transition from non-CSCs to differentiation of CSCs for evading conventional therapies and driving metastasis. Here we propose a therapeutic strategy of synergistic differentiation therapy and phototherapy to induce differentiation of CSCs into mature tumor cells by differentiation inducers and synergistic elimination of them and normal cancer cells through phototherapy. In this work, we synthesized a biomimetic nanoplatform loaded with IR-780 and all-trans retinoic acid (ATRA) via biomineralization. This method can integrate aluminum ions into small-sized protein carriers to form nanoclusters, which undergo responsive degradation under acidic conditions and facilitate deep tumor penetration. With the help of CSC differentiation induced by ATRA, IR-780 inhibited the self-renewal of CSCs and cancer progression by generating hyperthermia and reactive oxygen species in a synergistic manner. Furthermore, ATRA can boost immunogenic cell death induced by phototherapy, thereby strongly causing a systemic anti-tumor immune response and efficiently eliminating CSCs and tumor cells. Taken together, this dual strategy represents a new paradigm of targeted eradication of CSCs and tumors by inducing CSC differentiation, improving photothermal therapy/photodynamic therapy and enhancing antitumor immunity.

The Combination of PD-L1 and CTLA-4 Suppression Significantly Decreased the Expression Levels of Cancer Stem Cell Factors in the Pancreatic Cancer Cell Line

Background: It is thought that a limited number of aberrant cancer stem cells (CSCs), which encourage carcinogenesis, tumor metastasis, and treatment resistance, are the cause of pancreatic cancer, a disease with a high mortality rate. Increasing evidence shows that CSCs use immunosuppressive properties to avoid immune system identification. In Pancreatic cancer, the therapeutic consequences of the relationship between the expression of immune checkpoints such as programmed death receptor ligand-1 (PD-L1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the presence of CSCs are poorly known. As a result, in the present investigation, we examined how the expression levels of CSCs were affected by PD-L1 and CTLA-4 knockdown using specific siRNA. Methods: Independently and together, PD-L1 and CTLA-4 siRNA were transfected into MIA PaCa-2 cells. RNA extraction and cDNA synthesis were then performed. Finally, using qRT-PCR, the gene expression levels of CSCs markers, including Nanog, CD133, CD44, and Oct-4, in transfected groups were measured. Results: In the MIA PaCa-2 cell line, siRNA-mediated inhibition of PD-L1 and CTLA-4 decreased the expression of CSC factors. Moreover, combined suppression of these two stemness-related immune checkpoints significantly decreased Nanog, CD133, CD44, and Oct-4 expression compared to inhibition of PD-L1 and CTLA-4 separately. Conclusion: Considering that the combination of PD-L1 and CTLA-4 suppression using siRNA significantly decreased the expression levels of CSCs factors, this approach may be regarded as an effective therapy for this cancer.

CEPHAELINE SENSITIZES CISPLATIN AND REDUCES ORAL SQUAMOUS CELL CARCINOMA CANCER STEM CELLS

Objective To evaluate the anticancer properties of Cephaeline on Oral Squamous Cell Carcinoma (OSCC) cell lines, including cancer stem cell (CSC) maintenance. Study Design SCC4, SCC9, and SCC25 OSCC cell lines were used. Cell viability was assessed by MTT. The presence of CSC was evaluated by tumorsphere formation. The histone acetylation (H3K9ac) status was determined by immunofluorescence staining. Results A single administration of Cephaeline disrupted CSC by reducing the tumorsphere. Additionally, cephaeline impacted the histone acetylation status, and a concomitant therapy with CDDP reduces the concentration of CDDP required to achieve IC50 in two cell lines (SCC4 and SCC9). Conclusion Our findings suggest that Cephaeline has anti-cancer properties in OSCC, disrupting the ability of cancer cells to generate tumorspheres. Moreover, this may represent an adjunct therapy to conventional treatments for OSCC. In vivo studies are needed to validate these findings. Funding FAPESP 2016/05710-4 To evaluate the anticancer properties of Cephaeline on Oral Squamous Cell Carcinoma (OSCC) cell lines, including cancer stem cell (CSC) maintenance. SCC4, SCC9, and SCC25 OSCC cell lines were used. Cell viability was assessed by MTT. The presence of CSC was evaluated by tumorsphere formation. The histone acetylation (H3K9ac) status was determined by immunofluorescence staining. A single administration of Cephaeline disrupted CSC by reducing the tumorsphere. Additionally, cephaeline impacted the histone acetylation status, and a concomitant therapy with CDDP reduces the concentration of CDDP required to achieve IC50 in two cell lines (SCC4 and SCC9). Our findings suggest that Cephaeline has anti-cancer properties in OSCC, disrupting the ability of cancer cells to generate tumorspheres. Moreover, this may represent an adjunct therapy to conventional treatments for OSCC. In vivo studies are needed to validate these findings.

Tumor Microenvironment Role in Pancreatic Cancer Stem Cells.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with a majority of patients presenting with unresectable or metastatic disease, resulting in a poor 5-year survival rate. This, in turn, is due to a highly complex tumor microenvironment and the presence of cancer stem cells, both of which induce therapy resistance and tumor relapse. Therefore, understanding and targeting the tumor microenvironment and cancer stem cells may be key strategies for designing effective PDAC therapies. In the present review, we summarized recent advances in the role of tumor microenvironment in pancreatic neoplastic progression.