Cancer Stem Cells In Recurrence Research Articles

Abstract 2788: Immunological targeting of integrin β1high/β3high melanoma

Abstract We previously reported two integrin β4 (ITGB4)-targeted immunologic strategies, e.g., ITGB4 protein-pulsed dendritic cells (ITGB4-DC) for vaccination and adoptive transfer of anti-CD3/anti-ITGB4 bispecific antibody (ITGB4 BiAb)-armed tumor draining lymph node (TDLN) T cells. Both immunotherapies significantly demonstrated efficacy in inhibiting local tumor growth and lung metastases. We found these therapeutic efficacies were closely associated with the T cell as well as humoral anti-integrin β4high cancer stem cells (CSCs) in breast (4T1) and head and neck squamous cell carcinoma (SCC7) tumor models. Recently, we further found that integrin subunits β1 (ITGB1) and β3 (ITGB3) are expressed at significantly high level in melanoma cells. In culture cell lines, integrin β1 and β3 are highly expressed on approximately 98% and 95% of the two mouse melanoma cell lines F10 and D5. We confirmed the expression of these two integrin subunits in newly harvested fresh melanoma tumors in vivo, which is very similar to the findings in cell lines. We then assessed ITGB1 and/or ITGB3-pulsed dendritic cell (DC) vaccines using F10 mouse model and demonstrated that ITGB1-DC or ITGB3-DC vaccine both exhibited significant antitumor efficacy inhibiting tumor growth, and ITGB1-DC + ITGB3-DC showed an additive/synergistic anti-tumor effect. Notably, we found that ITGB1 and ITGB3 loaded on separate DCs demonstrated more potent antitumor efficacy than loaded on the same DCs as vaccine. In addition, anti-PD-L1 significantly augmented the antitumor efficacy of ITGB1-DC/ITGB3-DC vaccine to inhibit tumor growth. Considering the crucial role of CSCs in tumor initiation, progression, metastasis, and recurrence, we further evaluated the expression of ITGB1 and ITGB3 on F10 and D5 ALDHhigh CSCs. We detected significantly higher expression of ITGB1 on ALDHhigh F10 CSCs (83.3%) and ALDHhigh D5 CSCs (87.1%) vs. ALDHlow F10 non-CSCs (0.2%) and ALDHlow D5 non-CSCs (2.0%), suggesting that ITGB1 and ITGB3-targeted vaccine-conferred anti-melanoma effects may have significantly involved targeting of ITGB1high/ITGB3high melanoma CSCs. Furthermore, recent studies suggested that bone marrow (BM)-DCs expressing dysfunctional integrin β2 (ITGB2) exhibited more potent antigen presentation function than WT BM-DCs. We found that ITGB2 highly (63.3%) expressed on the surface of BM-DC, but not on F10 or D5 tumor cells. On-going experiments include the investigation of experimental evidence to verify that ITGB1 and ITGB3-targeted vaccines have induced targeting of ITGB1high/ITGB3high melanoma CSCs; and both the cellular and humoral mechanisms underlining the anti- ITGB1high/ITGB3high melanoma CSC immunity. At the same time, generation and use of ITGB2 deficient DCs for the vaccine preparation to improve the efficacy of DC vaccine targeting integrin ITGB1high/ITGB3high melanoma and melanoma CSCs warranty further investigation. Citation Format: Feng Wang, Ying Xin, James J. Moon, Alfred E. Chang, Max Wicha, Qiao Li. Immunological targeting of integrin β1high/β3high melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2788.

Defining lung cancer stem cells exosomal payload of miRNAs in clinical perspective.

Since the first publication regarding the existence of stem cells in cancer [cancer stem cells (CSCs)] in 1994, many studies have been published providing in-depth information about their biology and function. This research has paved the way in terms of appreciating the role of CSCs in tumour aggressiveness, progression, recurrence and resistance to cancer therapy. Targeting CSCs for cancer therapy has still not progressed to a sufficient degree, particularly in terms of exploring the mechanism of dynamic interconversion between CSCs and non-CSCs. Besides the CSC scenario, the problem of cancer dissemination has been analyzed in-depth with the identification and isolation of microRNAs (miRs), which are now considered to be compelling molecular markers in the diagnosis and prognosis of tumours in general and specifically in patients with non-small cell lung cancer. Paracrine release of miRs via "exosomes" (small membrane vesicles (30-100 nm), the derivation of which lies in the luminal membranes of multi-vesicular bodies) released by fusion with the cell membrane is gaining popularity. Whether exosomes play a significant role in maintaining a dynamic equilibrium state between CSCs and non-CSCs and their mechanism of activity is as yet unknown. Future studies on CSC-related exosomes will provide new perspectives for precision-targeted treatment strategies.

Transcriptomic Analysis of Breast Cancer Stem Cells and Development of a pALDH1A1:mNeptune Reporter System for Live Tracking

Many solid cancers are hierarchically organized with a small number of cancer stem cells (CSCs) able to regrow a tumor, while their progeny lacks this feature. Breast CSC is known to contribute to therapy resistance. The study of those cells is usually based on their cell-surface markers like CD44high /CD24low/neg or their aldehyde dehydrogenase (ALDH) activity. However, these markers cannot be used to track the dynamics of CSC. Here, a transcriptomic analysis is performed to identify segregating gene expression in CSCs and non-CSCs, sorted by Aldefluor assay. It is observed that among ALDH-associated genes, only ALDH1A1 isoform is increased in CSCs. A CSC reporter system is then developed by using a far red-fluorescent protein (mNeptune) under the control of ALDH1A1 promoter. mNeptune-positive cells exhibit higher sphere-forming capacity, tumor formation, and increased resistance to anticancer therapies. These results indicate that the reporter identifies cells with stemness characteristics. Moreover, live tracking of cells in a microfluidic system reveals a higher extravasation potential of CSCs. Live tracking of non-CSCs under irradiation treatment show, for the first time, live reprogramming of non-CSCs into CSCs. Therefore, the reporter will allow for cell tracking to better understand the implication of CSCs in breast cancer development and recurrence.

Recent advances of cancer stem cells in neuroblastoma

Cancer stem cells(CSC)is a group of tumor cells with self-renewal ability and multidirectional differentiation potential.Studies have found that CSC exist in a variety of tumor cells and are related to the tumor growth, chemotherapy drug resistance, metastasis and relapse.Similarly, this highly tumorigenic heterogeneous group has also been found in high-risk neuroblastoma(NB)cells.There are few studies focusing on CSC in NB, but it is undeniable that CSC play an important role in the treatment and prognosis of NB.This article reviews the progress of CSC in multidrug resistance, metastasis and recurrence in NB. Key words: Cancer stem cell; Neuroblastoma; Multidrug resistance; Metastasis

Ovarian cancer stem cells and their role in drug resistance.

Ovarian cancer is typically diagnosed at advanced stages (III or IV), with metastasis ensuing at stage III. Complete remission is infrequent and is not achieved in almost half of the women diagnosed with ovarian cancer. Consequently, management and treatment of this disease is challenging as many patients are faced with tumour recurrence disseminating to surrounding organs further complicated with acquired chemo-resistance. The cancer stem cell theory proposes the idea that a drug resistant subset of tumour cells drive tumour progression, metastasis and ultimately, recurrent disease. In the ovarian cancer field, cancer stem cells remain elusive with significant gaps in our knowledge. The characteristics and specific role of ovarian cancer stem cells in recurrence still requires further research since different studies often arrive at contradictory conclusions. Here we present a review and critical analysis of current research conducted in the field of ovarian cancer stem cells and their potential role in drug resistance including several signalling pathways within these cells that affect the viability of targeted therapies.

Research Progresses in Cancer Stem Cells of Three Common Fertility-Related Female Malignancies.

With abilities to renew themselves and lead to heterogeneity of tumors, cancer stem cells (CSCs) are similar to stem cells. As three leading causes of death that endanger women's health, breast cancer, ovarian cancer and cervical cancer are characterized by high degree of malignancy, metastasis and recurrence. Associated with women's fertility, these three malignancies are common and representative among females. These years, research findings have suggested that CSCs are closely connected with many cancers (including aforementioned three malignancies) and several processes of tumors such as their genesis and development. CSCs have become great concerns for current cancer treatment and interventions. This paper does not only summarize roles of CSCs in genesis, development, drug resistance, metastasis and recurrence of breast cancer, ovarian cancer and cervical cancer, but also proposes potential methods of treatment and intervention, in hope of inspiring readers and researchers.

Abstract 3015: Precise investigation of cancer stem cells in mouse glioblastoma

Abstract In this study, we employ mouse models to investigate features and roles of cancer stem cells (CSCs) in glioblastoma (GBM). A nestin-TK-GFP transgene is firstly used to label CSCs in a fully penetrant mouse model of GBM (M7: hGFAP-Cre; Nf1fl/+; p53fl/fl; Ptenfl/+). Food-mediated ganciclovir (GCV) delivery kills proliferative transgene positive cells and significantly prolongs the lives of the transgene bearing mice. Isolation and transplantation of the tumor cells indicates the GFP+ cells are more tumorigenic than the GFP- cells. We then generate and characterize a novel transgene (CGD: nestin-CreERT2-H2BeGFP-hDTR) that labels all the neural stem/progenitor cells in the subventricular zone (SVZ). This transgene efficiently promotes brain tumors by eliminating tumor suppressor genes (CGD-M4: CGD; Nf1fl/+; p53fl/+; Ptenfl/+) in the corresponding cells. The CGD-GFP+ tumor cells are quiescent in vivo, yet form more spheres in vitro than the GFP- cells. The GFP+ cells are competent to develop tumors in a serial transplantation assay and constantly maintain a quiescent subpopulation pool in the newly formed tumors. Diphtheria toxin treatment ablates the CGD-GFP+ tumor cells and greatly reduces the tumor bulk. Temozolomide, the conventional chemotherapy for human GBM patients, benefits only mice transplanted with GFP- but not CGD-GFP+ tumor cells. Our study demonstrates the essential role of CSCs in GBM initiation, recurrence, and drug resistance. Further analysis of the CGD-GFP+ cells might delineate novel treatments for this deadly disease. Citation Format: Xuanhua P. Xie, Dan R. Laks, Daochun Sun, Asaf Poran, Ashley M. Laughney, German Belenguer, Joan Massague, Xiuping Zhou, Isabel Farinas, Olivier Elemento, Luis F. Parada. Precise investigation of cancer stem cells in mouse glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3015.

Ovarian Cancer Prevention, Screening, and Early Detection: Report From the 11th Biennial Ovarian Cancer Research Symposium.

The aim of this study is to provide a summary report on recent research advances in ovarian cancer prevention, screening, and early detection that were presented at the 11th Biennial Ovarian Cancer Research Symposium in Seattle, Wash. At the symposium, researchers from around the world participated in the poster, invited oral presentation and keynote presentation, and discussed the latest advances in the areas of cancer prevention, screening, and early detection. In the Scientific Session for Prevention, Screening, and Early Detection, Usha Menon, PhD (University of College London), presented exploratory studies from the ongoing UK Collaborative Trial of Ovarian Cancer Screening trial. Karen Lu, MD, presented her studies on BRCA testing and salpingectomies as prevention strategies. Eight speakers were selected from the abstracts for short oral presentations, and the topic ranges from Ovarian Cancer Early Detection Program by Saul Rivkin, MD, to the ultra-deep sequencing of somatic mutations in TP53 in normal and cancer patients by Rosana Risques, PhD. Fourteen additional poster presentations, ranging from the potential role of cancer stem cells in recurrence to retrotransposons in ovarian cancer development, round up the session. Although progress is being made in the areas of prevention, screening, and early detection, these advances have not yet translated into tangible clinical benefits for patients with ovarian cancer. A wide array of research topics presented in the session provides a glimmer of hope that better understanding of genetic risk factors, refining screening strategies, and developing new methods for early detection will eventually lead to improved outcome for patients with ovarian cancer.

Tracing and targeting cancer stem cells: New venture for personalized molecular cancer therapy.

Tumors consist of a mixture of heterogeneous cell types. Cancer stem cells (CSCs) are a minor sub-population within the bulk cancer fraction which has been found to reconstitute and propagate the disease and to be frequently resistant to chemotherapy, irradiation, cytotoxic drugs and probably also against immune attack. CSCs are considered as the seeds of tumor recurrence, driving force of tumorigenesis and metastases. This underlines the urgent need for innovative methods to identify and target CSCs. However, the role and existence of CSCs in therapy resistance and cancer recurrence remains a topic of intense debate. The underlying biological properties of the tumor stem cells are extremely dependent on numerous signals, and the targeted inhibition of these stem cell signaling pathways is one of the promising approaches of the new antitumor therapy approaches. This perspective review article summarizes the novel methods of tracing CSCs and discusses the hallmarks of CSC identification influenced by the microenvironment or by having imperfect detection markers. In addition, explains the known molecular mechanisms of therapy resistance in CSCs as reliable and clinically predictive markers that could enable the use of new targeted antitumor therapy in the sense of personalized medicine.

Abstract LB-140: Investigating cancer stem cells in glioblastoma initiation and recurrence

Abstract In this study, I examine the unique features of quiescent cancer stem cells (CSCs) in glioblastoma initiation and recurrence in genetically engineered mouse models. A nestin-TK-GFP transgene was used to label CSCs with GFP and to render them susceptible to ganciclovir (GCV) treatment in a fully penetrant mouse model of GBM (M7: hGFAP-Cre; Nf1fl/+; p53fl/fl; Ptenfl). Using food-mediated GCV delivery (GCV chow) to optimize the drug delivery, Doublecortin-positive and NG2-positive cells derived from the nestin-TK-GFP transgene labeled neural stem cells were significantly reduced after six weeks. In addition, on GCV chow the tumor-bearing mice containing the nestin-TK-GFP transgene live significantly longer than the ones without the transgene. Isolation and transplantation of the GFP+/GFP- tumor cells demonstrated that the GFP+ cells have enhanced tumorigenic potential over the GFP- cells. These results support the hypothesis that the nestin-TK-GFP transgene targets the CSCs that are responsible for the sustained GBM growth. In the M7 model, the hGFAP transgene has a broader expression, and thus broader Cre targeting, than the nestin transgene. To eradicate the problem of differing scopes of Cre expression versus targeting of CSCs, I generated a new transgene (CGD: nestin-CreERT2-H2BeGFP-hDTR) that enables Cre-mediated recombination, specific cell labeling and targeted cell ablation. The CGD is designed to express a fusion protein that consists of CreERT2, H2B-eGFP, and hDTR (human diphtheria toxin receptor). Containing P2A linkers between the three gene cassettes, the fusion protein can be efficiently cleaved into three active. I have screened for a transgenic line that can induce GBM formation upon tamoxifen induction. Six to eight week-old mice with the following genetic configuration: CGD; Nf1fl/+; p53fl/+; Ptenfl/+, were given one dose of tamoxifen and all mice died of high grade gliomas three to six months later. The analysis of the CGD-induced tumors demonstrated that the CGD transgene labels tumor cells that are relatively quiescent, compared to the highly proliferative Ki67+ cells. Thus our CGD transgene labels putative CSCs within the tumor. In this model, the same cells initiating tumor formation (Cre-expressing) are also expressing H2B-eGFP and hDTR. Thus, all the tumor cells are derived from the CGD transgene and all the CSCs should be labeled with the H2B-eGFP protein. This dramatically facilitates the sorting of the tumor-initiating cells. Transplantation of the GFP+/GFP- cells in these tumors revealed that the quiescent GFP+ cells are more tumorigenic than the proliferating GFP- cells. Furthermore, diphtheria toxin-mediated ablation of the hDTR-expressing cells significantly elongates the lives of tumor-bearing mice. To mimic the endogenous environment for GBM growth, wild-type mice were also used to prove the differential tumorigenic ability of the GFP+/- cells. These results validate the essential roles of CSCs in GBM initiation and recurrence. Citation Format: xuanhua xie, Xiuping Zhou, German B. Sánchez, Luis F. Parada. Investigating cancer stem cells in glioblastoma initiation and recurrence. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-140. doi:10.1158/1538-7445.AM2015-LB-140

The Dark Side of Stem Cells: Triggering Cancer Progression by Cell Fusion

The phenomenon of cell fusion plays a crucial role in a plethora of physiological processes, including fertilization, wound healing, and tissue regeneration. In addition to this, cell fusion also takes place during pathophysiological processes such as virus entry into host cells and cancer. Particularly in cancer, cell fusion has been linked to a number of properties being associated with the progression of the disease including an increased proliferation rate, an enhanced metastatogenic behavior, an increased drug resistance and an increased resistance towards apoptosis. Although the process of cell fusion including the molecules to be involved-in is not completely understood in higher organisms, recent data revealed that chronic inflammation seems to be strong mediator. Since tumor tissue resembles chronically inflamed tissue, it can be concluded that cell fusion between recruited macrophages, bone marrow-derived cells (BMDCs), and tumor (stem) cells should be a common phenomenon in cancer. In the present review, we will summarize how a chronic inflamed microenvironment could originate in cancerous tissues, the role of M2-polarized tumor associated macrophages (M2-TAMs) within this process and how fusion between macrophages and BMDCs will trigger cancer progression. A particular emphasis will be drawn on recurrence cancer stem cells (rCSCs), which will play a pivotal role in "oncogenic resistance" and which might originate from fusion events between tumor (stem) cells and BMDCs.

Lung Cancer Stem Cells: Current Progress and Future Perspectives

Cancer stem cells (CSCs) have attracted a lot of interest in the field of cancer research in recent years. Lung CSCs share many characteristics with the normal pluripotent stem cells, such as self-renewal and multi-potent abilities. Identification of normal adult lung stem cells and their response to injury has led us to the lung cancer stem cells, partially based on the knowledge that lung CSCs as well as the normal lung stem cells share similar markers and/or location in the airway tree. Several studies have identified CD133, CD44, ALDH (aldehyde dehydrogenase) and ABCG2 (ATP-binding cassette sub-family G member 2) as lung cancer stem cell markers, all of which are validated CSC markers in multiple other cancer types as well. Embryogenesis signaling pathways, such as the hedgehog, wnt and notch pathways has also been implicated as determinants of lung CSC phenotype. With the central role of CSCs in tumor recurrence, metastasis and drug-resistance, targeting CSC markers and/or signaling pathways to eradicate lung cancer and enhance patient outcome is an attractive approach. This review summarizes our current understanding of CSC markers and signaling pathways in lung cancer.

The Role of Cancer Stem Cells in Breast Cancer Initiation and Progression: Potential Cancer Stem Cell-Directed Therapies

Recent studies have identified a small population of highly tumorigenic cells with stem cell properties in human breast and other solid tumors that are considered to be the source of tumor initiation and maintenance; these cells are referred to as cancer stem cells (CSCs). Preclinical data suggest that current breast cancer treatment strategies lead to CSC enrichment, contributing to chemotherapy and radiotherapy resistance, although a strong correlation with clinical parameters and prognosis is yet to be established. Importantly, overcoming treatment failure by effective targeting of CSCs may be an appealing approach, potentially leading to improved clinical outcomes for patients with breast cancer. Several preclinical studies provide promising results that support this hypothesis. The purpose of this review is to summarize the role of CSCs in breast cancer recurrence and resistance and to discuss current attempts of CSC targeting.

CD24−/low stem-like breast cancer marker defines the radiation-resistant cells involved in memorization and transmission of radiation-induced genomic instability

A growing body of evidence attributes properties of chemo- and/or radiation-resistance to cancer stem cells (CSCs). Moreover, non-targeted delayed effects such as genomic instability, transmitted through many generations, can be observed in the progeny of surviving irradiated cells. As a consequence, we propose that radiation-resistance properties associated to CSCs could confer a key role to this subpopulation in the transmission of genomic instability. To test this hypothesis, we searched the CSC markers associated to radiation-resistance in breast cancer cell lines and studied the role of the resistant cells in the transmission of genomic instability. First, we show that irradiation induces a 2-4 weeks period of intense cell death leading to the emergence of chromosomal unstable cells during more than 35 population doublings. Then, among seven breast CSC markers, we identify CD24(-/low) labelling as a marker of radiation-resistance. We demonstrate that CD24(+) progeny of irradiated cells exclusively descends from CD24(-/low) cells. Finally, we show that delayed chromosomal instability is only expressed by CD24(+) cells, but is transmitted by stable surviving CD24(-/low) cells. So, for the first time a CSC marker, CD24, is associated with the transmission of genomic instability. This work may assign a new deleterious role to breast CSCs in aggressive recurrence after radiotherapy, as the transmitted genomic instability potentially leads tumour cells to acquire more aggressive characteristics.

Recurrence cancer stem cells – Made by cell fusion?

Within the past 10-15 years our knowledge about cancer and how cancer cells might originate has changed dramatically. It is now generally believed that a tumor has its origin in cancer stem cells (CSCs), which originated either from transformed tissue stem cells or transformed progenitor cells that have regained self-renewal activity. CSCs share several characteristics of normal stem cells, such as self-renewal capacity, slow cell cycle activity, differentiation capacity, possessing an enhanced resistance towards cytotoxic agents and radiation, as well as tissue restoration capacity. Due to the increased drug and radiation resistance and slow cell cycle activity concomitant with tumor initiation capacity it is generally assumed that recurrent cancers originate from first line therapy surviving CSCs. But how does the CSC hypothesis explain "oncogenic resistance", which describes the phenomenon that most recurrent cancers are characterized by both an increased malignancy as well as resistance towards first line cancer therapy. To us, "oncogenic resistance" can not be simply attributed to the resistance properties of normal CSCs. If so, the recurring tumor should be treatable by first line therapy, which is mostly not the case. Thus, we conclude that "oncogenic resistance" demands a new type of tumor initiating cells, the so-called recurrence CSCs (rCSCs). This type of tumor initiating cell originates during first line therapy and is characterized by giving rise to first line therapy resistant and highly malignant progenies. Because several characteristics of "oncogenic resistance", such as increased drug resistance, increased resistance to apoptosis and an enhanced malignancy have been linked to cell fusion we further conclude that rCSCs might originate from this cellular event. However, which cell types have to fuse with each other to ultimately give rise to rCSCs is not clear. In any case, tumor tissues, particularly those being destructed by first line therapy comprise of a variety of fusogenic cells including tumor cells and CSCs as well as recruited monocytes/macrophages and bone marrow-derived stem cells. The fusogenic properties of these cells concomitant with phenotypic heterogeneity, which is also a property of cell fusion, will then lead to the origin of rCSCs. In accordance with Darwinian evolution only those cells will survive that can resist best to the selection pressure first line therapy.