Revisiting Cancer Stem Cells as the Origin of Cancer-Associated Cells in the Tumor Microenvironment: A Hypothetical View from the Potential of iPSCs

The tumor microenvironment: shaping cancer progression and treatment response

The tumor microenvironment (TME) plays a crucial role in cancer progression and treatment response. It comprises a complex network of stromal cells, immune cells, extracellular matrix, and blood vessels, all of which interact with cancer cells and influence tumor behaviour. This review article provides an in-depth examination of the TME, focusing on stromal cells, blood vessels, signaling molecules, and ECM, along with commonly available therapeutic compounds that target these components. Moreover, we explore the TME as a novel strategy for discovering new anti-tumor drugs. The dynamic and adaptive nature of the TME offers opportunities for targeting specific cellular interactions and signaling pathways. We discuss emerging approaches, such as combination therapies that simultaneously target cancer cells and modulate the TME. Finally, we address the challenges and future prospects in targeting the TME. Overcoming drug resistance, improving drug delivery, and identifying new therapeutic targets within the TME are among the challenges discussed. We also highlight the potential of personalized medicine and the integration of emerging technologies, such as immunotherapy and nanotechnology, in TME-targeted therapies. This comprehensive review provides insights into the TME and its therapeutic implications. Understanding the TME's complexity and targeting its components offer promising avenues for the development of novel anti-tumor therapies and improved patient outcomes.

Targeting the tumor microenvironment with mesenchymal stem cells based delivery approach for efficient delivery of anticancer agents: An updated review

Drug delivery to cancer cells continues to present a major therapeutic challenge. Mesenchymal stem cells (MSCs) possess an intrinsic ability to migrate specifically to tumor tissues, making them promising candidates for targeted drug delivery. Evidence from preclinical studies indicates that MSCs loaded with therapeutic anti-cancer agents exhibit considerable anti-tumor activity. Moreover, several clinical trials are currently evaluating their effectiveness in cancer patients. The integration of MSCs with synthetic nanoparticles (NPs) enhances their therapeutic potential, particularly through the use of cell membrane-coated NPs, which represent a significant advancement in the field. This review systematically investigates the tumor microenvironment, the sources of MSCs, the tumor homing mechanisms, and the methods of loading and releasing anticancer drugs from MSCs. Furthermore, cutting-edge strategies to improve the efficacy of MSCs based drug delivery systems (DDS) including the innovative use of MSC membrane coated nanoparticles have been discussed. The study concludes with an overview of the therapeutic use of MSCs as drug carriers, including a detailed analysis of the mechanisms by which MSCs deliver therapeutics to cancer cells, enabling targeted drug delivery. It aims to elucidate the current state of this approach, identify key areas for development, and outline potential future directions for advancing MSCs based cancer therapies.

A Landscape of Cancer Initiation and Cancer Stem Cells

Exposure to radiation and chemicals, oncogenic viruses, microbiomes, and inflammation are the major events of cancer initiation. DNA damage and chromosomal aberrations are classically considered the main causes of cancer. The recent idea of epigenetics is broadening the concept, including the suggestion that oncogenic virus infection disrupts various intracellular signaling cascades. Chronic inflammation was proposed as the origin of cancer in the 19th century, and the molecular level of events has been made clear with scientific development. Much knowledge of cancer initiation has become available for integration into research. Simultaneously, the presence of cancer stem cells has been identified and characterized. However, the point of shift from normal to malignant still appears obscure even when taking cancer stem cells into consideration. From these points of view, the advent of cancer stem cells and cancer initiation are briefly discussed as the points of shift from normal to malignant in this paper.

Intricate relationship between cancer stemness, metastasis, and drug resistance

Cancer stem cells (CSCs) are widely acknowledged as the drivers of tumor initiation, epithelial-mesenchymal transition (EMT) progression, and metastasis. Originating from both hematologic and solid malignancies, CSCs exhibit quiescence, pluripotency, and self-renewal akin to normal stem cells, thus orchestrating tumor heterogeneity and growth. Through a dynamic interplay with the tumor microenvironment (TME) and intricate signaling cascades, CSCs undergo transitions from differentiated cancer cells, culminating in therapy resistance and disease recurrence. This review undertakes an in-depth analysis of the multifaceted mechanisms underlying cancer stemness and CSC-mediated resistance to therapy. Intrinsic factors encompassing the TME, hypoxic conditions, and oxidative stress, alongside extrinsic processes such as drug efflux mechanisms, collectively contribute to therapeutic resistance. An exploration into key signaling pathways, including JAK/STAT, WNT, NOTCH, and HEDGEHOG, sheds light on their pivotal roles in sustaining CSCs phenotypes. Insights gleaned from preclinical and clinical studies hold promise in refining drug discovery efforts and optimizing therapeutic interventions, especially chimeric antigen receptor (CAR)-T cell therapy, cytokine-induced killer (CIK) cell therapy, natural killer (NK) cell-mediated CSC-targeting and others. Ultimately use of cell sorting and single cell sequencing approaches for elucidating the fundamental characteristics and resistance mechanisms inherent in CSCs will enhance our comprehension of CSC and intratumor heterogeneity, which ultimately would inform about tailored and personalized interventions.

Increased ONECUT2 induced by Helicobacter pylori promotes gastric cancer cell stemness via an AKT-related pathway

Helicobacter pylori (HP) infection initiates and promotes gastric carcinogenesis. ONECUT2 shows promise for tumor diagnosis, prognosis, and treatment. This study explored ONECUT2's role and the specific mechanism underlying HP infection-associated gastric carcinogenesis to suggest a basis for targeting ONECUT2 as a therapeutic strategy for gastric cancer (GC). Multidimensional data supported an association between ONECUT2, HP infection, and GC pathogenesis. HP infection upregulated ONECUT2 transcriptional activity via NFκB. In vitro and in vivo experiments demonstrated that ONECUT2 increased the stemness of GC cells. ONECUT2 was also shown to inhibit PPP2R4 transcription, resulting in reduced PP2A activity, which in turn increased AKT/β-catenin phosphorylation. AKT/β-catenin phosphorylation facilitates β-catenin translocation to the nucleus, initiating transcription of downstream stemness-associated genes in GC cells. HP infection upregulated the reduction of AKT and β-catenin phosphorylation triggered by ONECUT2 downregulation via ONECUT2 induction. Clinical survival analysis indicated that high ONECUT2 expression may indicate poor prognosis in GC. This study highlights a critical role played by ONECUT2 in promoting HP infection-associated GC by enhancing cell stemness through the PPP2R4/AKT/β-catenin signaling pathway. These findings suggest promising therapeutic strategies and potential targets for GC treatment.

Tumor microenvironment of cancer stem cells: Perspectives on cancer stem cell targeting

There are few tumor cell subpopulations with stem cell characteristics in tumor tissue, defined as cancer stem cells (CSCs) or cancer stem-like cells (CSLCs), which can reconstruct neoplasms with malignant biological behaviors such as invasiveness via self-renewal and unlimited generation. The microenvironment that CSCs depend on consists of various cellular components and corresponding medium components. Among these factors existing at a variety of levels and forms, cytokine networks and numerous signal pathways play an important role in signaling transduction. These factors promote or maintain cancer cell stemness, and participate in cancer recurrence, metastasis, and resistance. This review aims to summarize the recent molecular data concerning the multilayered relationship between CSCs and CSC-favorable microenvironments. We also discuss the therapeutic implications of targeting this synergistic interplay, hoping to give an insight into targeting cancer cell stemness for tumor therapy and prognosis.

Cancer Stem Cells from Definition to Detection and Targeted Drugs

Cancers remain the second leading cause of mortality in the world. Preclinical and clinical studies point an important role of cancer/leukaemia stem cells (CSCs/LSCs) in the colonisation at secondary organ sites upon metastatic spreading, although the precise mechanisms for specific actions are still not fully understood. Reviewing the present knowledge on the crucial role of CSCs/LSCs, their plasticity, and population heterogeneity in treatment failures in cancer patients is timely. Standard chemotherapy, which acts mainly on rapidly dividing cells, is unable to adequately affect CSCs with a low proliferation rate. One of the proposed mechanisms of CSC resistance to anticancer agents is the fact that these cells can easily shift between different phases of the cell cycle in response to typical cell stimuli induced by anticancer drugs. In this work, we reviewed the recent studies on CSC/LSC alterations associated with disease recurrence, and we systematised the functional assays, markers, and novel methods for CSCs screening. This review emphasises CSCs' involvement in cancer progression and metastasis, as well as CSC/LSC targeting by synthetic and natural compounds aiming at their elimination or modulation of stemness properties.

Targeting the key players of phenotypic plasticity in cancer cells by phytochemicals

Plasticity of phenotypic traits refers to an organism's ability to change in response to environmental stimuli. As a result, the response may alter an organism's physiological state, morphology, behavior, and phenotype. Phenotypic plasticity in cancer cells describes the considerable ability of cancer cells to transform phenotypes through non-genetic molecular signaling activities that promote therapy evasion and tumor metastasis via amplifying cancer heterogeneity. As a result of metastable phenotypic state transitions, cancer cells can tolerate chemotherapy or develop transient adaptive resistance. Therefore, new findings have paved the road in identifying factors and agents that inhibit or suppress phenotypic plasticity. It has also investigated novel multitargeted agents that may promise new effective strategies in cancer treatment. Despite the efficiency of conventional chemotherapeutic agents, drug toxicity, development of resistance, and high-cost limit their use in cancer therapy. Recent research has shown that small molecules derived from natural sources are capable of suppressing cancer by focusing on the plasticity of phenotypic responses. This systematic, comprehensive, and critical review analyzes the current state of knowledge regarding the ability of phytocompounds to target phenotypic plasticity at both preclinical and clinical levels. Current challenges/pitfalls, limitations, and future perspectives are also discussed.

Exploring Tumor-Promoting Qualities of Cancer-Associated Fibroblasts and Innovative Drug Discovery Strategies With Emphasis on Thymoquinone

Tumor epithelial development and chemoresistance are highly promoted by the tumor microenvironment (TME), which is mostly made up of the cancer stroma. This is due to several causes. Cancer-associated fibroblasts (CAFs) stand out among them as being essential for the promotion of tumors. Understanding the fibroblastic population within a single tumor is made more challenging by the undeniable heterogeneity within it, even though particular stromal alterations are still up for debate. Numerous chemical signals released by tumors improve the connections between heterotypic fibroblasts and CAFs, promoting the spread of cancer. It becomes essential to have a thorough understanding of this complex microenvironment to effectively prevent solid tumor growth. Important new insights into the role of CAFs in the TME have been revealed by recent studies. The objective of this review is to carefully investigate the relationship between CAFs in tumors and plant secondary metabolites, with a focus on thymoquinone (TQ). The literature published between 2010 and 2023 was searched in PubMed and Google Scholar with keywords such as TQ, TME, cancer-associated fibroblasts, mechanism of action, and flavonoids. The results showed a wealth of data substantiating the activity of plant secondary metabolites, particularly TQ's involvement in blocking CAF operations. Scrutinized research also clarified the wider effect of flavonoids on pathways related to cancer. The present study highlights the complex dynamics of the TME and emphasizes the critical role of CAFs. It also examines the possible interventions provided by secondary metabolites found in plants, with TQ playing a vital role in regulating CAF function based on recent literature.

Cancer-Associated Fibroblasts: Major Co-Conspirators in Tumor Development

The tumor microenvironment (TME) is a critical determinant of tumor progression, metastasis, and therapeutic outcomes [...].

Expression and Functional Analysis of core stemness factors OSKM (OCT4, SOX2, KLF4, and MYC) in Pan-cancer

The dedifferentiation process of tumorigenesis and somatic cell reprogramming has some commonness and differences, which is the key question to cancer therapeutic strategy and stem cell applications. To further explore the commonalities and variance between carcinogenesis and induced pluripotent stem cell reprogramming, we investigated the role of stemness factors OSKM (OCT4, SOX2, KLF4, and MYC) in the pan-cancer process using public clinical data. Expression of OSKM in human pan-cancer was analyzed via the Genotype Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) database based on the RNA-seq data of tissues. The correlation of expression between OSKM genes was analyzed via the Tumor Immune Evaluation Resource (TIMER) database, while the STRING tool was used to construct the protein-protein interaction network for OSKM. Prognostic impact of OSKM in pan-cancer was analyzed by Cox proportional hazards regression model. The relationships between OSKM and tumor stemness, tumor microenvironment and immune checkpoint and were performed by Sangerbox platform using Pearson correlation analysis. Our results showed that OSKM were universally expressed and significantly altered in tumors compared with adjacent normal tissues in most tumor types. In addition, correlation analysis revealed the relevance of OSKM genes to patient prognosis, cancer cell stemness, tumor microenvironment or immune checkpoint. However, there is little similarity between these genes in terms of how they function in each cancer type. This study elucidates the different roles of core stemness factors OSKM in pan-cancer, offering potential therapeutic targets for novel anti-cancer strategies and knowledge to minimize the potential carcinogenic effects during stem cell transplantation.

Exploring the promising potential of induced pluripotent stem cells in cancer research and therapy

The advent of iPSCs has brought about a significant transformation in stem cell research, opening up promising avenues for advancing cancer treatment. The formation of cancer is a multifaceted process influenced by genetic, epigenetic, and environmental factors. iPSCs offer a distinctive platform for investigating the origin of cancer, paving the way for novel approaches to cancer treatment, drug testing, and tailored medical interventions. This review article will provide an overview of the science behind iPSCs, the current limitations and challenges in iPSC-based cancer therapy, the ethical and social implications, and the comparative analysis with other stem cell types for cancer treatment. The article will also discuss the applications of iPSCs in tumorigenesis, the future of iPSCs in tumorigenesis research, and highlight successful case studies utilizing iPSCs in tumorigenesis research. The conclusion will summarize the advancements made in iPSC-based tumorigenesis research and the importance of continued investment in iPSC research to unlock the full potential of these cells.

Advancement in precision diagnosis and therapeutic for triple-negative breast cancer: Harnessing diagnostic potential of CRISPR-cas & engineered CAR T-cells mediated therapeutics

Cancer is characterized by uncontrolled cell growth, disrupted regulatory pathways, and the accumulation of genetic mutations. These mutations across different types of cancer lead to disruptions in signaling pathways and alterations in protein expression related to cellular growth and proliferation. This review highlights the AKT signaling cascade and the retinoblastoma protein (pRb) regulating cascade as promising for novel nanotheranostic interventions. Through synergizing state-of-the-art gene editing tools like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system with nanomaterials and targeting AKT, there is potential to enhance cancer diagnostics significantly. Furthermore, the integration of modified CAR-T cells into multifunctional nanodelivery systems offers a promising approach for targeted cancer inhibition, including the eradication of cancer stem cells (CSCs). Within the context of highly aggressive and metastatic Triple-negative Breast Cancer (TNBC), this review specifically focuses on devising innovative nanotheranostics. For both pre-clinical and post-clinical TNBC detection, the utilization of the CRISPR-Cas system, guided by RNA (gRNA) and coupled with a fluorescent reporter specifically designed to detect TNBC's mutated sequence, could be promising. Additionally, a cutting-edge approach involving the engineering of TNBC-specific iCAR and syn-Notch CAR T-cells, combined with the co-delivery of a hybrid polymeric nano-liposome encapsulating a conditionally replicative adenoviral vector (CRAdV) against CSCs, could present an intriguing intervention strategy. This review thus paves the way for exciting advancements in the field of nanotheranostics for the treatment of TNBC and beyond.

Cancer stem cells as the source of tumor associated myoepithelial cells in the tumor microenvironment developing ductal carcinoma in situ

The heterogeneous cell population in the stromal microenvironment is considered to be attributed to the multiple sources from which the cells originate. Tumor associated myoepithelial cells (TAMEs) are one of the most important populations in the tumor microenvironment (TME) especially in breast cancer. On the other hand, cancer stem cells (CSCs) have previously been described to be the origin of tumor-associated cellular components in the TME. We prepared a cancer stem cell model converting mouse-induced pluripotent stem cells (miPSCs) in the presence of conditioned medium of breast cancer cell line MDA-MB-231 cells. The converted cells developed tumors progressing into invasive carcinoma with ductal carcinoma in situ (DCIS) like structure when transplanted into mouse mammary fat pads. The primary cultured cells from the tumor further exhibited markers of CSC such as Sox2, Oct3/4, - CD133 and EpCAM, and mammary gland-related TAME markers such as α-smooth muscle actin, cytokeratin 8, whey acidic protein, prolactin receptor and progesterone receptor as well. These results indicated that the CSCs could be an origin of TAMEs contributing to mammary gland epithelial cell differentiation and the progression to invasive carcinoma during tumor development. The gene expression profiles confirmed the enhanced signaling pathways of PI3K/AKT and MAPK, which have been demonstrated to be enriched in the CSC models, together with the estrogen receptor signaling which was peculiar to mammary gland-derived character.

Extracellular vesicles promote activation of pro-inflammatory cancer-associated fibroblasts in oral cancer

Introduction: Oral squamous cell carcinoma (OSCC) is the most common form of head and neck cancer and has a survival rate of ∼50% over 5 years. New treatment strategies are sorely needed to improve survival rates-and a better understanding of the mechanisms underlying tumorigenesis is needed to develop these strategies. The role of the tumor microenvironment (TME) has increasingly been identified as crucial in tumor progression and metastasis. One of the main constituents of the TME, cancer-associated fibroblasts (CAFs), plays a key role in influencing the biological behavior of tumors. Multiple mechanisms contribute to CAF activation, such as TGFβ signaling, but the role of extracellular vesicles (EVs) in CAF activation in OSCC is poorly understood. Assessing the impact of oral cancer-derived EVs on CAF activation will help to better illuminate OSCC pathophysiology and may drive development of novel treatments options. Methods: EVs were isolated from OSCC cell lines (Cal 27, SCC-9, SCC-25) using differential centrifugation. Nanoparticle tracking analysis was used for EV characterization, and Western blot to confirm the presence of EV protein markers. Oral fibroblasts were co-cultured with enriched EVs, TGFβ, or PBS over 72 h to assess activation. Flow cytometry was used to evaluate CAF markers. RNA collected from fibroblasts was extracted and the transcriptome was sequenced. Conditioned media from the co-cultures was evaluated with cytokine array profiling. Results: OSCC-derived EVs can activate oral fibroblasts into CAFs that are different from those activated by TGFβ, suggesting different mechanisms of activation and different functional properties. Gene set enrichment analysis showed several upregulated inflammatory pathways in those CAFs exposed to OSCC-derived EVs. Marker genes for inflammatory CAF subtypes were also upregulated, but not in CAFs activated by TGFβ. Finally, cytokine array analysis on secreted proteins revealed elevated levels of several pro-inflammatory cytokines from EV-activated CAFs, for instance IL-8 and CXCL5. Discussion: Our results reveal the ability of OSCC-derived EVs to activate fibroblasts into CAFs. These CAFs seem to have unique properties, differing from TGFβ-activated CAFs. Gaining an understanding of the interplay between EVs and stromal cells such as CAFs could lead to further insights into OSCC tumorigenesis and potential novel therapeutics.

Stromal cells in the tumor microenvironment: accomplices of tumor progression?

The tumor microenvironment (TME) is made up of cells and extracellular matrix (non-cellular component), and cellular components include cancer cells and non-malignant cells such as immune cells and stromal cells. These three types of cells establish complex signals in the body and further influence tumor genesis, development, metastasis and participate in resistance to anti-tumor therapy. It has attracted scholars to study immune cells in TME due to the significant efficacy of immune checkpoint inhibitors (ICI) and chimeric antigen receptor T (CAR-T) in solid tumors and hematologic tumors. After more than 10 years of efforts, the role of immune cells in TME and the strategy of treating tumors based on immune cells have developed rapidly. Moreover, ICI have been recommended by guidelines as first- or second-line treatment strategies in a variety of tumors. At the same time, stromal cells is another major class of cellular components in TME, which also play a very important role in tumor metabolism, growth, metastasis, immune evasion and treatment resistance. Stromal cells can be recruited from neighboring non-cancerous host stromal cells and can also be formed by transdifferentiation from stromal cells to stromal cells or from tumor cells to stromal cells. Moreover, they participate in tumor genesis, development and drug resistance by secreting various factors and exosomes, participating in tumor angiogenesis and tumor metabolism, regulating the immune response in TME and extracellular matrix. However, with the deepening understanding of stromal cells, people found that stromal cells not only have the effect of promoting tumor but also can inhibit tumor in some cases. In this review, we will introduce the origin of stromal cells in TME as well as the role and specific mechanism of stromal cells in tumorigenesis and tumor development and strategies for treatment of tumors based on stromal cells. We will focus on tumor-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), tumor-associated adipocytes (CAAs), tumor endothelial cells (TECs) and pericytes (PCs) in stromal cells.

The role of cancer-associated fibroblasts in tumorigenesis of gastric cancer

Despite advances in anticancer therapy, the prognosis of gastric cancer (GC) remains unsatisfactory. Research in recent years has shown that the malignant behavior of cancer is not only attributable to tumor cells but is partly mediated by the activity of the cancer stroma and controlled by various molecular networks in the tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) are one of the most abundant mesenchymal cell components of the stroma and extensively participate in the malignant development of GC malignancy. CAFs modulate the biological properties of tumor cells in multiple ways, including the secretion of various bioactive molecules that have effects through paracrine and autocrine signaling, the release of exosomes, and direct interactions, thereby affecting GC initiation and development. However, there is marked heterogeneity in the cellular origins, phenotypes, and functions of CAFs in the TME of GC. Furthermore, variations in factors, such as proteins, microRNAs, and lncRNAs, affect interactions between CAFs and GC cells, although, the potential molecular mechanisms are still poorly understood. In this review, we aim to describe the current knowledge of the cellular features and heterogeneity of CAFs and discuss how these factors are regulated in CAFs, with a focus on how they affect GC biology. This review provides mechanistic insight that could inform therapeutic strategies and improve the prognosis of GC patients.

Cancer Stem Cells and the Tumor Microenvironment: Targeting the Critical Crosstalk through Nanocarrier Systems

The physiological state of the tumor microenvironment (TME) plays a central role in cancer development due to multiple universal features that transcend heterogeneity and niche specifications, like promoting cancer progression and metastasis. As a result of their preponderant involvement in tumor growth and maintenance through several microsystemic alterations, including hypoxia, oxidative stress, and acidosis, TMEs make for ideal targets in both diagnostic and therapeutic ventures. Correspondingly, methodologies to target TMEs have been investigated this past decade as stratagems of significant potential in the genre of focused cancer treatment. Within targeted oncotherapy, nanomedical derivates-nanocarriers (NCs) especially-have emerged to present notable prospects in enhancing targeting specificity. Yet, one major issue in the application of NCs in microenvironmental directed therapy is that TMEs are too broad a spectrum of targeting possibilities for these carriers to be effectively employed. However, cancer stem cells (CSCs) might portend a solution to the above conundrum: aside from being quite heavily invested in tumorigenesis and therapeutic resistance, CSCs also show self-renewal and fluid clonogenic properties that often define specific TME niches. Further scrutiny of the relationship between CSCs and TMEs also points towards mechanisms that underly tumoral characteristics of metastasis, malignancy, and even resistance. This review summarizes recent advances in NC-enabled targeting of CSCs for more holistic strikes against TMEs and discusses both the current challenges that hinder the clinical application of these strategies as well as the avenues that can further CSC-targeting initiatives. Central role of CSCs in regulation of cellular components within the TME.

Cancer-inducing niche: the force of chronic inflammation

The growth of cancer tissue is thought to be considered driven by a small subpopulation of cells, so-called cancer stem cells (CSCs). CSCs are located at the apex of a hierarchy in a cancer tissue with self-renewal, differentiation and tumorigenic potential that produce the progeny in the tissue. Although CSCs are generally believed to play a critical role in the growth, metastasis, and recurrence of cancers, the origin of CSCs remains to be reconsidered. We hypothesise that, chronic diseases, including obesity and diabetes, establish the cancer-inducing niche (CIN) that drives the undifferentiated/progenitor cells into CSCs, which then develop malignant tumours in vivo. In this context, a CIN could be traced to chronic inflammation that involves long-lasting tissue damage and repair after being exposed to factors such as cytokines and growth factors. This must be distinguished from the cancer microenvironment, which is responsible for cancer maintenance. The concept of a CIN is most important for cancer prevention as well as cancer therapy.

The Interaction Between Long Non-Coding RNAs and Cancer-Associated Fibroblasts in Lung Cancer

Despite great advances in research and treatment, lung cancer is still one of the most leading causes of cancer-related deaths worldwide. Evidence is mounting that dynamic communication network in the tumor microenvironment (TME) play an integral role in tumor initiation and development. Cancer-associated fibroblasts (CAFs), which promote tumor growth and metastasis, are the most important stroma component in the tumor microenvironment. Consequently, in-depth identification of relevant molecular mechanisms and biomarkers related to CAFs will increase understanding of tumor development process, which is of great significance for precise treatment of lung cancer. With the development of sequencing technologies such as microarray and next-generation sequencing, lncRNAs without protein-coding ability have been found to act as communicators between tumor cells and CAFs. LncRNAs participate in the activation of normal fibroblasts (NFs) to CAFs. Moreover, activated CAFs can influence the gene expression and secretion characteristics of cells through lncRNAs, enhancing the malignant biological process in tumor cells. In addition, lncRNA-loaded exosomes are considered to be another important form of crosstalk between tumor cells and CAFs. In this review, we focus on the interaction between tumor cells and CAFs mediated by lncRNAs in the lung cancer microenvironment, and discuss the analysis of biological function and molecular mechanism. Furthermore, it contributes to paving a novel direction for the clinical treatment of lung cancer.

Functional and Molecular Characters of Cancer Stem Cells Through Development to Establishment

Cancer stem cells (CSCs) are small subpopulation sharing similar properties like normal stem such as self-renewal and differentiation potential to direct tumor growth. Last few years, scientists considered CSCs as the cause of phenotypic heterogeneity in diverse cancer types. Also, CSCs contribute to cancer metastasis and recurrence. The cellular and molecular regulators influence on the CSCs' phenotype changing their behaviors in different stages of cancer progression. CSC markers play significance roles in cancer diagnosis and characterization. We delineate the cross-talks between CSCs and the tumor microenvironment that supports their intrinsic properties including survival, stemness, quiescence and their cellular and molecular adaptation. An insight into the markers of CSCs specific to organs is described.

Current hydrogel advances in physicochemical and biological response-driven biomedical application diversity

Hydrogel is a type of versatile platform with various biomedical applications after rational structure and functional design that leverages on material engineering to modulate its physicochemical properties (e.g., stiffness, pore size, viscoelasticity, microarchitecture, degradability, ligand presentation, stimulus-responsive properties, etc.) and influence cell signaling cascades and fate. In the past few decades, a plethora of pioneering studies have been implemented to explore the cell-hydrogel matrix interactions and figure out the underlying mechanisms, paving the way to the lab-to-clinic translation of hydrogel-based therapies. In this review, we first introduced the physicochemical properties of hydrogels and their fabrication approaches concisely. Subsequently, the comprehensive description and deep discussion were elucidated, wherein the influences of different hydrogels properties on cell behaviors and cellular signaling events were highlighted. These behaviors or events included integrin clustering, focal adhesion (FA) complex accumulation and activation, cytoskeleton rearrangement, protein cyto-nuclei shuttling and activation (e.g., Yes-associated protein (YAP), catenin, etc.), cellular compartment reorganization, gene expression, and further cell biology modulation (e.g., spreading, migration, proliferation, lineage commitment, etc.). Based on them, current in vitro and in vivo hydrogel applications that mainly covered diseases models, various cell delivery protocols for tissue regeneration and disease therapy, smart drug carrier, bioimaging, biosensor, and conductive wearable/implantable biodevices, etc. were further summarized and discussed. More significantly, the clinical translation potential and trials of hydrogels were presented, accompanied with which the remaining challenges and future perspectives in this field were emphasized. Collectively, the comprehensive and deep insights in this review will shed light on the design principles of new biomedical hydrogels to understand and modulate cellular processes, which are available for providing significant indications for future hydrogel design and serving for a broad range of biomedical applications.

Overcoming Therapy Resistance and Relapse in TNBC: Emerging Technologies to Target Breast Cancer-Associated Fibroblasts

Breast cancer is the most diagnosed cancer and is the leading cause of cancer mortality in women. Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer. Often, TNBC is not effectively treated due to the lack of specificity of conventional therapies and results in relapse and metastasis. Breast cancer-associated fibroblasts (BCAFs) are the predominant cells that reside in the tumor microenvironment (TME) and regulate tumorigenesis, progression and metastasis, and therapy resistance. BCAFs secrete a wide range of factors, including growth factors, chemokines, and cytokines, some of which have been proved to lead to a poor prognosis and clinical outcomes. This TME component has been emerging as a promising target due to its crucial role in cancer progression and chemotherapy resistance. A number of therapeutic candidates are designed to effectively target BCAFs with a focus on their tumor-promoting properties and tumor immune response. This review explores various agents targeting BCAFs in TNBC, including small molecules, nucleic acid-based agents, antibodies, proteins, and finally, nanoparticles.

Mesenchymal stromal cells: Putative microenvironmental modulators become cell therapy

An exceptional safety profile has been shown in a large number of cell therapy clinical trials that use mesenchymal stromal cells (MSCs). However, reliable potency assays are still lacking to predict MSC immunosuppressive efficacy in the clinical setting. Nevertheless, MSCs are approved in Japan and Europe for the treatment of graft-versus-host and Crohn's fistular diseases, but not in the United States for any clinical indication. We discuss potential mechanisms of action for the therapeutic effects of MSC transplantation, experimental models that dissect tissue modulating function of MSCs, and approaches for identifying MSC effects in vivo by integrating biomarkers of disease and MSC activity.

Proteomics and its applications in breast cancer

Breast cancer is an individually unique, multi-faceted and chameleonic disease, an eternal challenge for the new era of high-integrated precision diagnostic and personalized oncomedicine. Besides traditional single-omics fields (such as genomics, epigenomics, transcriptomics and metabolomics) and multi-omics contributions (proteogenomics, proteotranscriptomics or reproductomics), several new "-omics" approaches and exciting proteomics subfields are contributing to basic and advanced understanding of these "multiple diseases termed breast cancer": phenomics/cellomics, connectomics and interactomics, secretomics, matrisomics, exosomics, angiomics, chaperomics and epichaperomics, phosphoproteomics, ubiquitinomics, metalloproteomics, terminomics, degradomics and metadegradomics, adhesomics, stressomics, microbiomics, immunomics, salivaomics, materiomics and other biomics. Throughout the extremely complex neoplastic process, a Breast Cancer Cell Continuum Concept (BCCCC) has been modeled in this review as a spatio-temporal and holistic approach, as long as the breast cancer represents a complex cascade comprising successively integrated populations of heterogeneous tumor and cancer-associated cells, that reflect the carcinoma's progression from a "driving mutation" and formation of the breast primary tumor, toward the distant secondary tumors in different tissues and organs, via circulating tumor cell populations. This BCCCC is widely sustained by a Breast Cancer Proteomic Continuum Concept (BCPCC), where each phenotype of neoplastic and tumor-associated cells is characterized by a changing and adaptive proteomic profile detected in solid and liquid minimal invasive biopsies by complex proteomics approaches. Such a profile is created, beginning with the proteomic landscape of different neoplastic cell populations and cancer-associated cells, followed by subsequent analysis of protein biomarkers involved in epithelial-mesenchymal transition and intravasation, circulating tumor cell proteomics, and, finally, by protein biomarkers that highlight the extravasation and distant metastatic invasion. Proteomics technologies are producing important data in breast cancer diagnostic, prognostic, and predictive biomarkers discovery and validation, are detecting genetic aberrations at the proteome level, describing functional and regulatory pathways and emphasizing specific protein and peptide profiles in human tissues, biological fluids, cell lines and animal models. Also, proteomics can identify different breast cancer subtypes and specific protein and proteoform expression, can assess the efficacy of cancer therapies at cellular and tissular level and can even identify new therapeutic target proteins in clinical studies.

Cancer-associated fibroblasts: overview, progress, challenges, and directions

Tumors are one of the main causes of death in humans. The development of safe and effective methods for early diagnosis and treatment of tumors is a difficult problem that needs to be solved urgently. It is well established that the occurrence of tumors involves complex biological mechanisms, and the tumor microenvironment (TME) plays an important role in regulating the biological behavior of tumors. Cancer-associated fibroblasts (CAFs) are a group of activated fibroblasts with significant heterogeneity and plasticity in the tumor microenvironment. They secrete a variety of active factors to regulate tumor occurrence, development, metastasis, and therapeutic resistance. Although most studies suggest that CAFs have significant tumor-promoting functions, some evidence indicates that they may have certain tumor-suppressive functions in the early stage of tumors. Current research on CAFs continues to face many challenges, and the heterogeneity of their origin, phenotype, and function is a major difficulty and hot spot. To provide new perspectives for the research on CAFs and tumor diagnosis and treatment, this review summarizes the definition, origin, biomarkers, generation mechanism, functions, heterogeneity, plasticity, subpopulations, pre-metastasis niches (PMN), immune microenvironment, and targeted therapy of CAFs, describes the research progress and challenges, and proposes possible future research directions based on existing reports.

Cancer Stem Cells and their Management in Cancer Therapy

BACKGROUND

In the last decade, the proposed Cancer Stem Cell (CSC) hypothesis has steadily changed the way cancer treatment is approached. CSCs may be the source of the heterogeneous non-tumorigenic cell population included in a neoplasm. Intratumor and intertumoral heterogeneity is a well-known phenomenon that massively entangles the diagnosis and treatment of cancer. The literature seems to suggest that heterogeneity develops progressively within tumor-initiating stem cells. CSCs harbor genetic and/or epigenetic alterations that allow them to differentiate into multiple tumor cell types sequentially.

OBJECTIVE

The CSC hypothesis, cellular therapy, and the most recent patents on CSCs were reviewed.

METHODS

PubMed, Scopus, and Google Scholar were screened for this information. Also, an analysis of the most recent data targeting CSCs in pediatric cancer developed at two Canadian institutions is provided. The genes involved with the activation of CSCs and the drugs used to antagonize them are also highlighted.

RESULTS

It is underlined that (1) CSCs possess stem cell-like properties, including the ability for self-renewal; (2) CSCs can start carcinogenesis and are responsible for tumor recurrence after treatment; (3) Although some limitations have been raised, which may oppose the CSC hypothesis, cancer progression and metastasis have been recognized to be caused by CSCs.

CONCLUSION

The significant roles of cell therapy may include an auto-transplant with high-dose treatment, an improvement of the immune function, creation of chimeric antigen receptor T cells, and the recruitment of NK cell-based immunotherapy.

Plectin in Cancer: From Biomarker to Therapeutic Target

The cytolinker and scaffolding protein, plectin, has emerged as a potent driver of malignant hallmarks in many human cancers due to its involvement in various cellular activities contributing to tumorigenesis, including cancer cell proliferation, adhesion, migration, invasion, and signal transduction. Evidence shows that beyond plectin's diverse protein interactome, its cancer-specific mislocalization to the cell surface enables its function as a potent oncoprotein. As such, therapeutic targeting of plectin, its protein interactors, and, in particular, cancer-specific plectin (CSP) presents an attractive opportunity to impede carcinogenesis directly. Here, we report on plectin's differential gene and protein expression in cancer, explore its mutational profile, and discuss the current understanding of plectin's and CSP's biological function in cancer. Moreover, we review the landscape of plectin as a prognostic marker, diagnostic biomarker, and target for imaging and therapeutic modalities. We highlight how, beyond their respective biological importance, plectin's common overexpression in cancer and CSP's cancer-specific bioavailability underscore their potential as high-value druggable targets. We discuss how recent evidence of the potent anti-cancer effects of CSP therapeutic targeting opens the door for cell-surface mislocalized proteins as novel therapeutic targets.

Linking Tumor Microenvironment to Plasticity of Cancer Stem Cells: Mechanisms and Application in Cancer Therapy

Cancer stem cells (CSCs) are a minority subset of cancer cells that can drive tumor initiation, promote tumor progression, and induce drug resistance. CSCs are difficult to eliminate by conventional therapies and eventually mediate tumor relapse and metastasis. Moreover, recent studies have shown that CSCs display plasticity that renders them to alter their phenotype and function. Consequently, the varied phenotypes result in varied tumorigenesis, dissemination, and drug-resistance potential, thereby adding to the complexity of tumor heterogeneity and further challenging clinical management of cancers. In recent years, tumor microenvironment (TME) has become a hotspot in cancer research owing to its successful application in clinical tumor immunotherapy. Notably, emerging evidence shows that the TME is involved in regulating CSC plasticity. TME can activate stemness pathways and promote immune escape through cytokines and exosomes secreted by immune cells or stromal cells, thereby inducing non-CSCs to acquire CSC properties and increasing CSC plasticity. However, the relationship between TME and plasticity of CSCs remains poorly understood. In this review, we discuss the emerging investigations on TME and CSC plasticity to illustrate the underlying mechanisms and potential implications in suppressing cancer progression and drug resistance. We consider that this review can help develop novel therapeutic strategies by taking into account the interlink between TME and CSC plasticity.

Cancer: a mirrored room between tumor bulk and tumor microenvironment

It has been well documented that the tumor microenvironment (TME) plays a key role in the promotion of drug resistance, the support of tumor progression, invasiveness, metastasis, and even the maintenance of a cancer stem-like phenotype. Here, we reviewed TME formation presenting it as a reflection of a tumor’s own organization during the different stages of tumor development. Interestingly, functionally different groups of stromal cells seem to have specific spatial distributions within the TME that change as the tumor evolves into advanced stage progression which correlates with the fact that cancer stem-like cells (CSCs) are located in the edges of solid tumor masses in advanced tumors.

We also focus on the continuos feedback that is established between a tumor and its surroundings. The “talk” between tumor mass cells and TME stromal cells, marks the evolution of both interlocuting cell types. For instance, the metabolic and functional transformations that stromal cells undergo due to tumor corrupting activity.

Moreover, the molecular basis of metastatic spread is also approached, making special emphasis on the site-specific pre-metastatic niche formation as another reflection of the primary tumor molecular signature.

Finally, several therapeutic approaches targeting primary TME and pre-metastatic niche are suggested. For instance, a systematic analysis of the TME just adjacent to the tumor mass to establish the proportion of myofibroblasts-like cancer-associated fibroblasts (CAFs) which may in turn correspond to stemness and metastases-promotion. Or the implementation of “re-education” therapies consisting of switching tumor-supportive stromal cells into tumor-suppressive ones. In summary, to improve our clinical management of cancer, it is crucial to understand and learn how to manage the close interaction between TME and metastasis.

Paclitaxel-Based Chemotherapy Targeting Cancer Stem Cells from Mono- to Combination Therapy

Paclitaxel (PTX) is a chemotherapeutical agent commonly used to treat several kinds of cancer. PTX is known as a microtubule-targeting agent with a primary molecular mechanism that disrupts the dynamics of microtubules and induces mitotic arrest and cell death. Simultaneously, other mechanisms have been evaluated in many studies. Since the anticancer activity of PTX was discovered, it has been used to treat many cancer patients and has become one of the most extensively used anticancer drugs. Regrettably, the resistance of cancer to PTX is considered an extensive obstacle in clinical applications and is one of the major causes of death correlated with treatment failure. Therefore, the combination of PTX with other drugs could lead to efficient therapeutic strategies. Here, we summarize the mechanisms of PTX, and the current studies focusing on PTX and review promising combinations.

Cancer stem cells and macrophages: molecular connections and future perspectives against cancer

Cancer stem cells (CSCs) have been considered the key drivers of cancer initiation and progression due to their unlimited self-renewal capacity and their ability to induce tumor formation. Macrophages, particularly tumor-associated macrophages (TAMs), establish a tumor microenvironment to protect and induce CSCs development and dissemination. Many studies in the past decade have been performed to understand the molecular mediators of CSCs and TAMs, and several studies have elucidated the complex crosstalk that occurs between these two cell types. The aim of this review is to define the complex crosstalk between these two cell types and to highlight potential future anti-cancer strategies.

CD73, Tumor Plasticity and Immune Evasion in Solid Cancers

Simple Summary

Tumors are ecosystems composed of cancer cells and non-tumor stroma together in a hypoxic environment often described as wounds that do not heal. Accumulating data suggest that solid tumors hijack cellular plasticity possibly to evade detection by the immune system. CD73-mediated generation of the purine nucleoside adenosine, is an important biochemical constituent of the immunosuppressive tumor microenvironment. In this review, the association between CD73 expression and features associated with cellular plasticity involving stemness, epithelial-to-mesenchymal transition and metastasis together with immune infiltration is summarized for a wide range of solid tumor types. Our analyses demonstrate that CD73 correlates with signatures associated with cellular plasticity in solid tumors. In addition, there are strong associations between CD73 expression and type of infiltrating lymphocytes. Collectively, the observations suggest a biomarker-based stratification to identify CD73-adenosinergic rich tumors may help identify patients with solid cancers who will respond to a combinatorial strategy that includes targeting CD73.

Abstract

Regulatory networks controlling cellular plasticity, important during early development, can re-emerge after tissue injury and premalignant transformation. One such regulatory molecule is the cell surface ectoenzyme ecto-5′-nucleotidase that hydrolyzes the conversion of extracellular adenosine monophosphate to adenosine (eADO). Ecto-5′-nucleotidase (NT5E) or cluster of differentiation 73 (CD73), is an enzyme that is encoded by NT5E in humans. In normal tissue, CD73-mediated generation of eADO has important pleiotropic functions ranging from the promotion of cell growth and survival, to potent immunosuppression mediated through purinergic G protein-coupled adenosine receptors. Importantly, tumors also utilize several mechanisms mediated by CD73 to resist therapeutics and in particular, evade the host immune system, leading to undesired resistance to targeted therapy and immunotherapy. Tumor cell CD73 upregulation is associated with worse clinical outcomes in a variety of cancers. Emerging evidence indicates a link between tumor cell stemness with a limited host anti-tumor immune response. In this review, we provide an overview of a growing body of evidence supporting the pro-tumorigenic role of CD73 and adenosine signaling. We also discuss data that support a link between CD73 expression and tumor plasticity, contributing to dissemination as well as treatment resistance. Collectively, targeting CD73 may represent a novel treatment approach for solid cancers.

Cancer Stem Cell Microenvironment Models with Biomaterial Scaffolds In Vitro

Defined by its potential for self-renewal, differentiation and tumorigenicity, cancer stem cells (CSCs) are considered responsible for drug resistance and relapse. To understand the behavior of CSC, the effects of the microenvironment in each tissue are a matter of great concerns for scientists in cancer biology. However, there are many complicated obstacles in the mimicking the microenvironment of CSCs even with current advanced technology. In this context, novel biomaterials have widely been assessed as in vitro platforms for their ability to mimic cancer microenvironment. These efforts should be successful to identify and characterize various CSCs specific in each type of cancer. Therefore, extracellular matrix scaffolds made of biomaterial will modulate the interactions and facilitate the investigation of CSC associated with biological phenomena simplifying the complexity of the microenvironment. In this review, we summarize latest advances in biomaterial scaffolds, which are exploited to mimic CSC microenvironment, and their chemical and biological requirements with discussion. The discussion includes the possible effects on both cells in tumors and microenvironment to propose what the critical factors are in controlling the CSC microenvironment focusing the future investigation. Our insights on their availability in drug screening will also follow the discussion.

Tumor-associated macrophages derived from cancer stem cells

Macrophages are the most abundant immune cells in the microenvironment of solid tumors. The present study displayed histological and immunohistochemical analyses of a malignant tumor model developed from cancer stem cells (CSCs) converted from human induced pluripotent stem cells (hiPSCs) in a cancer microenvironment prepared from the conditioned medium (CM) of a pancreatic cancer cell line. We focused on the localization and the origin of tumor-associated macrophages (TAMs), To the best of our knowledge this may be the first study to suggest the potential differentiation of CSCs to TAMs. hiPSCs were converted into CSCs in the presence of CM from PK8 cells. CSCs were then transplanted in vivo and formed primary tumors. Primary cultures for these tumors were serially transplanted again to obtain secondary tumors. Secondary tumors exhibited histopathological features of malignancy. Cells derived from tumors maintained the expression of endogenous stemness markers and pancreatic CSCs markers. Simultaneously, high immunoreactivity to anti-mouse CD68, anti-human CD68, CD206 and CD11b antibodies were detected revealing that the tumor tissue derived from CSCs was enriched for macrophages which can originate from both human and mouse cells. The model of CSCs highlighted the possibility of CSCs to differentiate into TAMs.

Tumor Microenvironment Uses a Reversible Reprogramming of Mesenchymal Stromal Cells to Mediate Pro-tumorigenic Effects

The role of mesenchymal stromal cells (MSCs) in the tumor microenvironment is well described. Available data support that MSCs display anticancer activities, and that their reprogramming by cancer cells in the tumor microenvironment induces their switch toward pro-tumorigenic activities. Here we discuss the recent evidence of pro-tumorigenic effects of stromal cells, in particular (i) MSC support to cancer cells through the metabolic reprogramming necessary to maintain their malignant behavior and stemness, and (ii) MSC role in cancer cell immunosenescence and in the establishment and maintenance of immunosuppression in the tumor microenvironment. We also discuss the mechanisms of tumor microenvironment mediated reprogramming of MSCs, including the effects of hypoxia, tumor stiffness, cancer-promoting cells, and tumor extracellular matrix. Finally, we summarize the emerging strategies for reprogramming tumor MSCs to reactivate anticancer functions of these stromal cells.

Emerging data supporting stromal cell therapeutic potential in cancer: reprogramming stromal cells of the tumor microenvironment for anti-cancer effects

After more than a decade of controversy on the role of stromal cells in the tumor microenvironment, the emerging data shed light on pro-tumorigenic and potential anti-cancer factors, as well as on the roots of the discrepancies. We discuss the pro-tumorigenic effects of stromal cells, considering the effects of tumor drivers like hypoxia and tumor stiffness on these cells, as well as stromal cell-mediated adiposity and immunosuppression in the tumor microenvironment, and cancer initiating cells' cellular senescence and adaptive metabolism. We summarize the emerging data supporting stromal cell therapeutic potential in cancer, discuss the possibility to reprogram stromal cells of the tumor microenvironment for anti-cancer effects, and explore some causes of discrepancies on the roles of stromal cells in cancer in the available literature.

Intratumoral Adipocyte-High Breast Cancer Enrich for Metastatic and Inflammation-Related Pathways but Associated with Less Cancer Cell Proliferation

Cancer-associated adipocytes are known to cause inflammation, leading to cancer progression and metastasis. The clinicopathological and transcriptomic data from 2256 patients with breast cancer were obtained based on three cohorts: The Cancer Genome Atlas (TCGA), GSE25066, and a study by Yau et al. For the current study, we defined the adipocyte, which is calculated by utilizing a computational algorithm, xCell, as "intratumoral adipocyte". These intratumoral adipocytes appropriately reflected mature adipocytes in a bulk tumor. The amount of intratumoral adipocytes demonstrated no relationship with survival. Intratumoral adipocyte-high tumors significantly enriched for metastasis and inflammation-related gene sets and are associated with a favorable tumor immune microenvironment, especially in the ER+/HER2- subtype. On the other hand, intratumoral adipocyte-low tumors significantly enriched for cell cycle and cell proliferation-related gene sets. Correspondingly, intratumoral adipocyte-low tumors are associated with advanced pathological grades and inversely correlated with MKI67 expression. In conclusion, a high amount of intratumoral adipocytes in breast cancer was associated with inflammation, metastatic pathways, cancer stemness, and favorable tumor immune microenvironment. However, a low amount of adipocytes was associated with a highly proliferative tumor in ER-positive breast cancer. This cancer biology may explain the reason why patient survival did not differ by the amount of adipocytes.

Macrophages in Oral Carcinomas: Relationship with Cancer Stem Cell Markers and PD-L1 Expression

Tumor-associated macrophages (TAMs) can be polarized into antitumoral M1 and protumoral and immunosuppressive M2 macrophages. This study investigated the clinical relevance of TAM infiltration in oral squamous cell carcinoma (OSCC), evaluating CD68 (M1 and M2 macrophage marker) and CD163 expression (M2 macrophage marker) in the tumor nests and surrounding stroma. Immunohistochemical analysis of both stromal/tumoral CD68⁺ and CD163⁺ TAMs was performed in paraffin-embedded tissue specimens from 125 OSCC patients, and correlated with clinical data. Potential relationships with the expression of cancer stem cell (CSC) markers and PD-L1 in the tumors were also assessed. Stromal CD163⁺ infiltration was significantly associated with the tumor location in the tongue, and stromal and tumoral CD68⁺ and CD163⁺-infiltrating TAMs were more abundant in nonsmokers and non-alcohol-drinkers. Strikingly, this study uncovers an inverse relationship between CD68⁺ and CD163⁺ TAMs and CSC marker expression (NANOG and SOX2) in OSCC. High infiltration of CD163⁺ TAMs in both tumor and stroma was strongly and significantly correlated with the absence of NANOG expression. Moreover, infiltration of both CD68⁺ and CD163⁺ TAMs was also significantly associated with high tumor expression of PD-L1. Our results suggest that there is a link between TAM infiltration and immune escape in OSCC.

Whole Organism Model to Study Molecular Mechanisms of Differentiation and Dedifferentiation

Cancer recurrence has remained a significant challenge, despite advances in therapeutic approaches. In part, this is due to our incomplete understanding of the biology of cancer stem cells and the underlying molecular mechanisms. The phenomenon of differentiation and dedifferentiation (phenotypic switching) is not only unique to stem cells but it is also observed in several other organisms, as well as evolutionary-related microbes. Here, we propose the use of a primitive eukaryotic unicellular organism, Acanthamoeba castellanii, as a model to study the molecular mechanisms of cellular differentiation and dedifferentiation.