Correction: 89Zr-labeled ImmunoPET targeting the cancer stem cell antigen CD133 using fully-human antibody constructs

Background: Ovarian cancer serves as the first leading lethally gynecologic cancer, of which around 70% of patients would relapse soon even have undergone standard treatment. Several mechanisms work together attributing to the early relapse. Among these, cancer stem cells (CSCs) act as the root of metastasis and relapse in the early reports. However, limited methods directly targeting these rare populations have been developed so far. Here we develop DC vaccine directly targeting CSCs by loading DCs with enriched cancer stem cell antigen (CSC-Ag) in vitro. Methods: Freshly dissected ovarian tumors are digested into single cell suspension with digestive enzymes. Subsequently, fluorescence-activated cell sorting (FACS) is used to isolate CD44CD133 double-positive cells, previously reported surface markers of CSCs. Basic medium supplied with several cytokines is used to maintain and enrich CSCs. Suspension of enriched stem cell spheres is repeated five freeze-thaw cycles in liquid nitrogen and 37-degree Celsius water bath, and the supernatant after centrifugation is regarded as CSC-Ag. CD14+ cells of patients’ PBMCs are isolated using CD14 microbeads according to manufacturer’s instruction. IL-4 and GM-CSF are added to induce DC. Immature DC are loaded with previously prepared CSC-Ag. Meanwhile, CD14- cells are cultured with the supplement of anti-CD3, anti-CD28 antibodies, and rhIL-2. T cells are soon co-cultured with mature DC for further antigen-presenting. In vitro cytotoxicity against OC cell lines are tested. Additionally, we developed a peritoneal metastatic ovarian cancer cell model by injecting OVCAR8 transfected with luciferase into NSG mice. IVIS system is used later to monitor tumor growth twice a week. Result: Both CD44 and CD133 were highly expressed in ovarian cancers compared with normal tissue in matched TCGA and GTEx datasets. CD44CD133 double-positive cells ranged from 0.00% to 59.10% in our OC cohort (n=21). CSCs were successfully isolated and enriched, confirmed by the expression of stem cell markers, including SOX2, OCT4, and NANOG. CSC-Ag also expressed those markers comparable to freshly cultured CSC. DC-CSC+T showed remarkable efficacy both in vitro and in vivo against ovarian cancer, with more cancer cell apoptosis. Conclusion: Dendritic cells pulsed with cancer-stem cell antigen (DC-CSC+T) could significantly lower the growth rate of OC, and may serve as a potential adjuvant therapy for improving OC disease-free interval. Citation Format: Haixi Liang, Tong Xiang, Lin Zhou, Zhiwen Xie, Mao Ye, Chunyan Lan. Dendritic cells pulsed with cancer stem cell antigen showed profound anti-tumoral efficacy in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3550.

Cancer stem cells (CSCs) are a rare population of tumor cells, which play an important role in tumor initiation, progression, and maintenance. The concept that cancer cells arise from stem cells was presented about 150 years ago. Recently, this hypothesis was renewed considering the heterogeneity of tumor cells. CSCs are resistant to chemo- and radio-therapy. Therefore, targeting CSCs could be a novel and effective strategy to struggle with tumor cells. In this mini-review, we highlight that different immunotherapeutic approaches can be used to target cancer cells and eradicate different tumor cells. The most important targets are specific markers recognized on the CSC surface as CSC antigens such as CD44, CD133, Aldehyde Dehydrogenase (ALDH), and SOX family members. This article emphasizes recent advances in CSCs in cancer therapy. Our results present that CSC antigens play an important role in tumor initiation, especially in the cells that are resistant to chemo- and radiotherapy agents. Therefore, they are ideal targets for cancer immunotherapy, for instance, in developing different types of cancer vaccines or antibodies against tumor cells. The current studies related to cancer immunotherapy through targeting the CSC antigens based on their properties are briefly summarized. Altogether, CSC antigens can be efficiently targeted to treat cancer patients.

Introduction: Localized prostate cancer (PCa) can be successfully treated by androgen deprivation, radiotherapy and surgery, however these may not be sufficient to eradicate cancer stem cells (CSCs). CSCs are more resistant to such treatments than the bulk of the tumor; and can contribute to disease relapse. PCa patients who relapse have a poor prognosis. We hypothesize that CSCs could be killed by T-cells in an antigen specific way, thus preventing the possibility of relapse. In this study we identified novel PCa CSC antigens by HLA ligandome analysis and isolated antigen specific CD8+ T-cells. Methods: We identified CSCs using aldehyde dehydrogenase (ALDH) activity as a CSC marker. ALDH high and low cells from the DU145 PCa cell line and from prostate adenocarcinoma primary tissue were characterized in vitro; DU145 CSCs and non-CSCs were additionally characterized in vivo. We isolated peptide-HLA complexes from DU145 cells by immunoprecipitation and analyzed the eluted peptides by mass spectrometry. We identified CSC antigens based on the gene expression in ALDH high and low DU145 cells (measured by qPCR). To select antigens for further analysis we performed homology modelling of the HLA-peptide interface using COOT software and the YASARA server for energy minimization. The interface interactions were quantified using PISA software. We additionally confirmed antigen expression in the primary cells by fluorescence microscopy and PCR. Tetramers were produced to isolate T-cells which recognized a selection of these antigens. Results: The ligandome analysis identified over 1900 peptides. We selected antigens with low gene expression in healthy tissues (www.GTexportal.org) and high predicted binding to DU145 HLA alleles (http://tools.immuneepitope.org/mhci/). ALDH high DU145 cells were more tumorigenic in vivo than ALDH low cells. ALDH high DU145 and primary prostate cancer cells grew larger colonies and spheres in vitro. We identified 11 CSC antigens by qPCR; 6 upregulated in ALDH high DU145 cells (e.g., TACSTD2) and 5 abundant in both ALDH high and ALDH low DU145 cells (e.g., XPO1). Relevant 9-mer epitopes from three antigens* induced CD8+ T-cell responses in vitro. Antigen-specific CD8+ T-cells were identified by tetramer staining at a frequency of approx. 15 per 100000 cells. These cells are currently being expanded to use in CTL assays. Conclusion: We have identified CSC antigens which could lead to specific targeting by T-cells and prevention of PCa relapse. Further epitopes restricted to the more frequent HLA alleles could additionally be predicted in silico from the novel antigens we identified. We are also investigating prediction of viral epitopes highly aligned with the self-peptides (determined in silico) to boost the immune response against CSCs. *Subject of an ongoing patent application. Citation Format: Amy S. Codd, Saly Al-Taei, Serina Tokita, Emi Mizushima, Pierre J. Rizkallah, Tom Whalley, Barbara Szomolay, Kristin Ladell, James E. McLaren, Sian Llewellyn-Lacey, David A. Price, Takayuki Kanaseki, Toshihiko Torigoe, Stephen Man, Zsuzsanna Tabi. Identification of prostate cancer stem cell antigens for T-cell immunotherapy by HLA ligandome analysis [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B007.

Comparison of cancer stem cell antigen expression by tumor cell lines and by tumor biopsies from dogs with melanoma and osteosarcoma

Moving Forward in Human Mammary Stem Cell Biology and Breast Cancer Prognostication Using ALDH1

Current treatments for oligodendrogliomas are powerful but have a negative impact on the rest of the body. The bone marrow is damaged by the chemotherapeutics, but other parts of the body are also affected. In this paper, the current treatment method and its collateral damage is described. Therefore, therapies are needed that are more effective against the tumor while having less negative effects on the patient’s quality of life. Some potential therapies include optimal removal of the tumor by fluorescent-guided surgery (FGS), intraoperative desorption electrospray ionization-mass spectrometry (DESI-MS), better monitoring of the effects of therapy by pseudo-coloring shades of gray of MRI pictures, and using recent data from RNA sequencing of single cells and immunotherapy. These are all open new ways of treating this tumor. The RNA sequencing of single tumor cells unravels specific tumor antigens present in the differentiation status of the cancer cell. Stem cell antigens were expressed in dividing cells, while hypoxia inducible factor-α (HIF-1α) is expressed in all tumor cells. Cancer stem cell antigens can be loaded on dendritic cells to induce cytotoxic T-cells directed to cancer stem cells. These recent discoveries suggest a better quality of life with the same overall survival.

Cancer Stem Cell–Directed Therapies: Recent Data From the Laboratory and Clinic

BackgroundHepatocellular carcinoma (HCC) is one of the most common cancers worldwide and the adoptive immunotherapy of which is worth studying. CD133, a kind of cancer stem cell (CSC) antigen, together with glypican-3 (GPC3) has been proved to be highly expressed in HCC cells and both of them are used as targets to generate chimeric antigen receptor (CAR) T cells. But there are limitations like “off-target” toxicity, low transfection efficacy and weak antitumor ability in CAR T cells treatment.MethodsThe peripheral blood was acquired from healthy donors and T cells were separated by density-gradient centrifugation. We used an electroporation system to deliver anti-CD133 and anti-GPC3 single chain Fragment variable (scFv) structures as target genes into the T cells. The cell membrane was opened by the momentary electric current effect, and the target gene was delivered into the cell by non-viral minicircle DNA (mcDNA) vector. The flow cytometry and western blot assays were used to detect whether the two scFv were simultaneously transfected and the transfection efficacy of this bispecific CAR T cell generation method. We respectively detected the in vitro and in vivo tumor-suppression efficacy of CAR T cells through the CCK-8 assays and the HCC xenograft mice models. The CoG133-CAR T cells containing both CD133 and GPC3 antigen recognition sites were the effector cells. CD133-CAR T cells and GPC3-CAR T cells were defined as single-targeted control groups, normal T and mock T cells were defined as blank control groups.ResultsThe mcDNA vector accommodated two target gene structures successfully transfected to generate bispecific CAR T cells. The detection methods on gene level and protein level confirmed that CoG133-CAR T cells had considerable transfection efficiency and exhibited both antigen-binding capacity of CD133 and GPC3. Compared to single-targeted CAR T cells or control T cells, CoG133-CAR T cells performed enhanced eliminated efficacy against CD133 and GPC3 double-positive HCC cell line in vitro and HCC xenograft mice in vivo. Hematoxylin and eosin (H&E) staining indicated no fatal “off-target” combination existed on CoG133-CAR T cells and major organs.ConclusionOur study suggests that it is with higher efficiency and more safety to prepare bispecific CAR T cells through non-viral mcDNA vectors. CoG133-CAR T cells have enhanced tumor-suppression capacity through dual antigen recognition and internal activation. It provides an innovative strategy for CAR T therapy of HCC, even solid tumors.

![][1] The Spanish National Cancer Institute (CNIO) Meeting on Development and Cancer took place between 4 and 6 February 2008 in Madrid, Spain, and was organized by K. Basler, G. Morata, E. Moreno and M. Torres. ![][2] Developmental biologists rightly argue that genes regulating developmental pathways are reiterated in cancer development. At the recent Spanish National Cancer Institute (CNIO) Meeting on Development and Cancer, novel concepts and processes that are considered to be common to both embryonic and cancer development were discussed. It is worth pointing out that tumour formation should be considered to be a form of aberrant organ development, in which many developmental pathways that control proliferation, differentiation and growth or morphogenesis are affected. This report is structured in three parts, describing the work presented at the meeting according to the stages of tumour development to which it pertains. First, the normal behaviour of cell populations that are the targets of transformation, in particular adult stem cells and the pathways that regulate their behaviour. Second, processes that occur at the early stages of cancer development before morphological malformations are detectable, in particular the process that is best known from studies in flies as ‘cell competition’. Third, developmental processes and pathways that are active in the growing tumour—which we consider to be an extrinsic organ—for example, the recruitment of blood vessels or the role of morphogens in controlling the size and shape of tumours, and the progression from hyperplasia to invasive tumours (Fig 1). Figure 1. Tumour development and genes involved in the different stages. Schematic representation of how stem cells (A) , by acquiring a mutation through cell competition ( B ) and by the selection of additional mutations, can give rise to the ‘tumour organ’ ( C ). The genes involved in these processes are listed on the right‐hand side, and most of them … [1]: /embed/graphic-1.gif [2]: /embed/graphic-2.gif

1942P IL6 pre-treatment promotes chemosensitivity by eliminating quiescent cancer stem cells

The Sixteenth International Symposium of the Hiroshima Cancer Seminar (HCS) Foundation was held on October 22 2006 at the International Conference Center, Hiroshima. The symposium consisted of 10 special lectures and 23 free paper presentations for a poster session. About 230 people were present and actively discussed cancer stem cells. Prior to this symposium, an Open Lecture to the public by HCS and the Japan Society for Dying with Dignity was held on October 21 where Shigehito Yamawaki (Hiroshima University, Hiroshima) and Kazuko Hamanaka (Hamanaka Dermatological Clinic, Hiroshisma) spoke about Psycho-oncology and Breast Cancer to more than 260 people. Eiichi Tahara (Hiroshima Cancer Seminar Foundation), Chairman of the Organizing Committee of the Sixteenth International Symposium, and Chairman of the HCS Foundation, gave an opening address. Tahara introduced a brief background and the purpose of this series of symposia. Since the establishment of the HCS Foundation in 1992, annual international symposia are organized to create an opportunity for basic scientists and clinical researchers to exchange ideas for cancer research, cancer prevention and cancer therapy. This year, the organizing committee planned to explore the important issue of cancer stem cells. Stem cells have a critical role not only in the generation of new populations of normal cells but also in the development of tumors. The balance between self-renewal and differentiation is strictly regulated to maintain normal stem cell pools and to generate the required supply of fully differentiated cells. Recent evidence has suggested that a subset of cancer cells within the tumor, so-called cancer stem cells, may drive the growth and progression of the tumor. Eradication of cancer stem cells may be essential to a cure for cancer. Advances in our knowledge that regulate proliferation, self-renewal, survival and differentiation of cancer stem cells and normal stem cells may shed light on the mechanism that leads to cancer and perhaps improve cancer treatment. The participants will be able to profit by exchanging ideas and learning from the informative presentations and discussions, and will contribute to our understanding of stem cells in relation to cancer development and treatment.

Bone Marrow-Derived Cells Are Not the Origin of the Cancer Stem Cells in Ultraviolet-Induced Skin Cancer

Comparison of hematopoietic cancer stem cells with normal stem cells leads to discovery of novel differentially expressed SSRs

The recognition that myocyte mitosis occurs in the fetal, neonatal, adult, and hypertrophied heart and that a pool of primitive, undifferentiated cells is present in the myocardium has put forward a different view of the biology of the heart. The new paradigm suggests that myocyte formation is preserved during postnatal life, in adulthood or senescence, pointing to a remarkable growth reserve of the heart throughout the course of life of the organism. This article reviews a large body of novel information, which has been obtained in the last 2 decades, in favor of the notion that the mammalian heart has the inherent ability to continuously replace its parenchymal cells and that this unexpected characteristic has important implications in understanding myocardial homeostasis, cardiac aging, and tissue repair. The paradigm that the heart is a postmitotic organ incapable of regenerating parenchymal cells was established in the 1970s, and this dogma has profoundly conditioned basic and clinical research in cardiology for the last 3 decades. On the basis of this paradigm, cardiomyocytes undergo cellular hypertrophy1,2 but cannot be replaced either by entry into the cell cycle of a subpopulation of nonterminally differentiated myocytes or by activation of a pool of primitive cells that become committed to the myocyte lineage. The only response of cardiomyocytes to stress is hypertrophy and/or death. Therefore, a tremendous effort was made to identify the molecular mechanisms of myocyte hypertrophy and their genetic control. A sophisticated knowledge of various signaling pathways has been achieved, and our understanding of the biology of hypertrophic myocyte growth has advanced markedly.3 An array of new technologies has been introduced that has led to a scientific revolution in terms of questions, approaches, and interpretation of experimental results. Despite this enormous progress in our understanding of basic mechanisms of hypertrophy, however, very little …

Cloned 20 years ago, stem cell antigen-1 (Sca-1) is used extensively to enrich for murine hematopoietic stem cells. The realization that many different stem cell types share conserved biochemical pathways has led to a flood of recent research using Sca-1 as a candidate marker in the search for tissue-resident and cancer stem cells. Although surprisingly little is still known about its biochemical function, the generation and analysis of knockout mice has begun to shed light on the functions of Sca-1 in stem and progenitor cells, demonstrating that it is more than a convenient marker for stem cell biologists. This review summarizes the plethora of recent findings utilizing Sca-1 as a parenchymal stem cell marker and detailing its functional role in stem and progenitor cells and also attempts to explain the lingering mysteries surrounding its biochemical function and human ortholog. Disclosure of potential conflicts of interest is found at the end of this article.