Differentiation of cancer stem cells into erythroblasts in the presence of CoCl2

Signaling, cancer cell plasticity, and intratumor heterogeneity

Cancer's complexity is in part due to the presence of intratumor heterogeneity and the dynamic nature of cancer cell plasticity, which create substantial obstacles in effective cancer management. Variability within a tumor arises from the existence of diverse populations of cancer cells, impacting the progression, spread, and resistance to treatments. At the core of this variability is the concept of cellular plasticity - the intrinsic ability of cancer cells to alter their molecular and cellular identity in reaction to environmental and genetic changes. This adaptability is a cornerstone of cancer's persistence and progression, making it a formidable target for treatments. Emerging studies have emphasized the critical role of such plasticity in fostering tumor diversity, which in turn influences the course of the disease and the effectiveness of therapeutic strategies. The transformative nature of cancer involves a network of signal transduction pathways, notably those that drive the epithelial-to-mesenchymal transition and metabolic remodeling, shaping the evolutionary path of cancer cells. Despite advancements, our understanding of the precise molecular machinations and signaling networks driving these changes is still evolving, underscoring the necessity for further research. This editorial presents a series entitled "Signaling Cancer Cell Plasticity and Intratumor Heterogeneity" in Cell Communication and Signaling, dedicated to unraveling these complex processes and proposing new avenues for therapeutic intervention.

Cancer stem cells: a target for overcoming therapeutic resistance and relapse

Cancer stem cells (CSCs) are a small subset of cells in cancers that are thought to initiate tumorous transformation and promote metastasis, recurrence, and resistance to treatment. Growing evidence has revealed the existence of CSCs in various types of cancers and suggested that CSCs differentiate into diverse lineage cells that contribute to tumor progression. We may be able to overcome the limitations of cancer treatment with a comprehensive understanding of the biological features and mechanisms underlying therapeutic resistance in CSCs. This review provides an overview of the properties, biomarkers, and mechanisms of resistance shown by CSCs. Recent findings on metabolic features, especially fatty acid metabolism and ferroptosis in CSCs, are highlighted, along with promising targeting strategies. Targeting CSCs is a potential treatment plan to conquer cancer and prevent resistance and relapse in cancer treatment.

Increasing glutathione levels by a novel posttranslational mechanism inhibits neuronal hyperexcitability

Glutathione (GSH) depletion, and impaired redox homeostasis have been observed in experimental animal models and patients with epilepsy. Pleiotropic strategies that elevate GSH levels via transcriptional regulation have been shown to significantly decrease oxidative stress and seizure frequency, increase seizure threshold, and rescue certain cognitive deficits. Whether elevation of GSH per se alters neuronal hyperexcitability remains unanswered. We previously showed that thiols such as dimercaprol (DMP) elevate GSH via post-translational activation of glutamate cysteine ligase (GCL), the rate limiting GSH biosynthetic enzyme. Here, we asked if elevation of cellular GSH by DMP altered neuronal hyperexcitability in-vitro and in-vivo. Treatment of primary neuronal-glial cerebrocortical cultures with DMP elevated GSH and inhibited a voltage-gated potassium channel blocker (4-aminopyridine, 4AP) induced neuronal hyperexcitability. DMP increased GSH in wildtype (WT) zebrafish larvae and significantly attenuated convulsant pentylenetetrazol (PTZ)-induced acute 'seizure-like' swim behavior. DMP treatment increased GSH and inhibited convulsive, spontaneous 'seizure-like' swim behavior in the Dravet Syndrome (DS) zebrafish larvae (scn1Lab). Furthermore, DMP treatment significantly decreased spontaneous electrographic seizures and associated seizure parameters in scn1Lab zebrafish larvae. We investigated the role of the redox-sensitive mammalian target of rapamycin (mTOR) pathway due to the presence of several cysteine-rich proteins and their involvement in regulating neuronal excitability. Treatment of primary neuronal-glial cerebrocortical cultures with 4AP or l-buthionine-(S,R)-sulfoximine (BSO), an irreversible inhibitor of GSH biosynthesis, significantly increased mTOR complex I (mTORC1) activity which was rescued by pre-treatment with DMP. Furthermore, BSO-mediated GSH depletion oxidatively modified the tuberous sclerosis protein complex (TSC) consisting of hamartin (TSC1), tuberin (TSC2), and TBC1 domain family member 7 (TBC1D7) which are critical negative regulators of mTORC1. In summary, our results suggest that DMP-mediated GSH elevation by a novel post-translational mechanism can inhibit neuronal hyperexcitability both in-vitro and in-vivo and a plausible link is the redox sensitive mTORC1 pathway.

Erythroid Cells as Full Participants in the Tumor Microenvironment

The tumor microenvironment is an important factor that can determine the success or failure of antitumor therapy. Cells of hematopoietic origin are one of the most important mediators of the tumor-host interaction and, depending on the cell type and functional state, exert pro- or antitumor effects in the tumor microenvironment or in adjacent tissues. Erythroid cells can be full members of the tumor microenvironment and exhibit immunoregulatory properties. Tumor growth is accompanied by the need to obtain growth factors and oxygen, which stimulates the appearance of the foci of extramedullary erythropoiesis. Tumor cells create conditions to maintain the long-term proliferation and viability of erythroid cells. In turn, tumor erythroid cells have a number of mechanisms to suppress the antitumor immune response. This review considers current data on the existence of erythroid cells in the tumor microenvironment, formation of angiogenic clusters, and creation of optimal conditions for tumor growth. Despite being the most important life-support function of the body, erythroid cells support tumor growth and do not work against it. The study of various signaling mechanisms linking tumor growth with the mobilization of erythroid cells and the phenotypic and functional differences between erythroid cells of different origin allows us to identify potential targets for immunotherapy.

The roles of Linc-ROR in the regulation of cancer stem cells

Cancer stem cells (CSCs) are considered to be a kind of tumor cell population characterized by self-renewal, easy to metastasize and drug resistance, which play an indispensable role in the occurrence, development, metastasis and drug resistance of tumors, and their existence is an important reason for high metastasis and recurrence of tumors. Long non-coding RNAs (LncRNAs), which are more than 200 nucleotides in length, have a close relationship with the malignant progression of cancer.In recent years, abundant studies have reavling that LncRNAs are beneficial to the regulation of various cancer stem cells. Linc-ROR, as a newly discovered intergenic non-protein-coding RNA in recent years, is considered to be a key regulator affecting the development of human tumors. Dysregulation of Linc-ROR is related to stemness phenotype and functional regulation of cancer stem cells. For that, Linc-ROR has the potential to be used as a diagnostic biomarker for cancer patients and can serve as a clinically meaningful potential therapeutic target. In this review, we generalize the existing research results on the important role of Linc-ROR in regulation of CSCs.

Regulation of the Cancer Stem Phenotype by Long Non-Coding RNAs

Cancer stem cells are a cell population within malignant tumors that are characterized by the ability to self-renew, the presence of specific molecules that define their identity, the ability to form malignant tumors in vivo, resistance to drugs, and the ability to invade and migrate to other regions of the body. These characteristics are regulated by various molecules, such as lncRNAs, which are transcripts that generally do not code for proteins but regulate multiple biological processes through various mechanisms of action. LncRNAs, such as HOTAIR, H19, LncTCF7, LUCAT1, MALAT1, LINC00511, and FMR1-AS1, have been described as key regulators of stemness in cancer, allowing cancer cells to acquire this phenotype. It has been proposed that cancer stem cells are clinically responsible for the high recurrence rates after treatment and the high frequency of metastasis in malignant tumors, so understanding the mechanisms that regulate the stem phenotype could have an impact on the improvement of cancer treatments.

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.

IL-22 Protects against Biliary Ischemia-Reperfusion Injury after Liver Transplantation via Activating STAT3 and Reducing Apoptosis and Oxidative Stress Levels In Vitro and In Vivo

Biliary complications are currently one of the leading causes of liver failure and patient death after liver transplantation and need to be solved urgently. Biliary ischemia-reperfusion injury (IRI) is one of the important causes of biliary complications. IL-22 has a protective effect on liver injury and hepatitis diseases, and its safety and efficacy in the treatment of hepatitis have also been proved in human clinical experiments. Furthermore, multiple studies have confirmed that IL-22 promotes the proliferation and repair of epithelial cells in various organs. Still, its function in the bile duct after transplantation has not been explored. This study was aimed at investigating the effects of IL-22 on cholangiocyte IRI in vitro and in vivo and exploring its underlying mechanisms. We simulated the hypoxia process of bile duct epithelial cells through in vitro experiments to investigate the protective function and molecular mechanism of IL-22 on bile duct epithelial cells. Subsequently, the function and mechanism of IL-22 in the biliary IRI model of autologous orthotopic liver transplantation in rats were assessed. This study confirmed that IL-22 could promote cholangiocyte proliferation, decrease the apoptosis rate of cholangiocytes and tissues, decrease MDA levels, and increase SOD levels by activating STAT3. In addition, IL-22 can also reduce the level of mitochondrial membrane depolarization, protect mitochondria, reduce ROS production, and play a role in protecting bile ducts. These findings provide evidence for IL-22 as a novel and effective treatment for biliary IRI after liver transplantation.