JAK-STAT signalling controls cancer stem cell properties including chemotherapy resistance in myxoid liposarcoma

Relationship between ZHX2 Expression and VHL Gene Alteration in VHL-associated and Sporadic Hemangioblastomas of the Central Nervous System

Central nervous system hemangioblastoma (CNS-HB) is the most common manifestation of von Hippel-Lindau disease (VHL). The main axis of the CNS-HB pathway is the VHL-HIF signaling pathway. Recently, we proposed an alternative VHL-JAK-STAT pathway in CNS-HB. In contrast, the VHL substrate transcription factor zinc fingers and homeoboxes 2 (ZHX2) have been identified as the oncogenic drivers in VHL-deficient clear cell renal cell carcinoma (RCC). However, ZHX2 expression in CNS-HB has not been previously reported. Furthermore, the VHL-ZXH2-NF-κB signaling pathway in CNS-HB remains unresolved. In this study, we aimed to investigate ZHX2 expression and VHL gene alteration in CNS-HB and propose the role of ZHX2 in CNS-HB. Using the MACS method, Scl+ hemangioblastoma-like cells were isolated from multipotent nestin-expressing stem cells. The ubiquitination of ZHX2 in these cells and the immunoprecipitation between ZHX2 and VHL were investigated. In addition, the VHL genes of patients with hemangioblastoma were analyzed. ZHX2 expression in CNS-HB tissues was examined by immunohistochemistry and western blotting. In addition, VHL gene mutations in CNS-HB were analyzed by sequencing. The association between ZHX2 expression and VHL gene mutation was analyzed. ZHX2 was ubiquitinated in Scl+hemangioblastoma-like cells after the transfer of the VHL expression vector into these cells. ZHX2 expression in these cells was well detected before transfer but disappeared after the transfer. ZHX2 expression was detected in 18 of the 21 CNS-HB tissues by immunoblotting and/or immunohistochemistry. Sporadic CNS-HB showed weak expression, whereas VHL-related CNS-HB showed moderate or strong expression. In particular, CNS-HB with severe VHL gene mutations, including large deletions, showed strong or moderate ZHX2 expression. The association between VHL gene mutation and ZHX2 expression revealed a significant correlation between VHL gene alteration severity and the level of immunoblotting (P < 0.05). In conclusion, the severity of VHL gene alteration correlates with the level of ZHX2 expression. ZHX2 is predominantly expressed in CNS-HB, especially in VHL-related cases with severe VHL gene alterations, suggesting a potential role in tumorigenesis and proliferation of CNS-HB.

FUS::DDIT3 Fusion Protein in the Development of Myxoid Liposarcoma and Possible Implications for Therapy

The FUS::DDIT3 fusion protein, formed by the chromosomal translocation t (12;16) (q13;p11), is found in over 90% of myxoid liposarcoma (MLS) cases and is a crucial protein in its development. Many studies have explored the role of FUS::DDIT3 in MLS, and the prevailing view is that FUS::DDIT3 inhibits adipocyte differentiation and promotes MLS growth and invasive migration by functioning as an aberrant transcription factor that affects gene expression and regulates its downstream molecules. As fusion proteins are gradually showing their potential as targets for precision cancer therapy, FUS::DDIT3 has also been investigated as a therapeutic target. Drugs that target FUS::DDIT3 and its downstream molecules for treating MLS are widely utilized in both clinical practice and experimental studies, and some of them have demonstrated promising results. This article reviews the findings of relevant research, providing an overview of the oncogenic mechanisms of the FUS::DDIT3 fusion protein in MLS, as well as recent advancements in its therapy.

RGS1 targeted by miR-191-3p inhibited the stemness properties of esophageal cancer cells by suppressing CXCR4/PI3K/AKT signaling

BACKGROUND

Esophageal cancer is one of the most common malignant tumors in the world. It is urgent to prevent the development and progression of esophageal cancer. Cancer stem cells (CSCs) were reported to have the ability to initiate tumorigenesis, and reducing the stem cell-like characteristics of tumors is an important strategy to inhibit the occurrence and development of tumors. miRNAs are key regulators of the stemness of cancer. Here, we aimed to investigate the role and regulatory mechanism of miR-191-3p in the stemness properties of esophageal cancer cells.

METHODS

Esophageal cancer cells with stable expression of miR-191-3p were established by lentivirus system. CCK-8 assay, transwell assay, wound healing assay were used to evaluate the effect of miR-191-3p on proliferation and metastasis of esophageal cancer cells. The expression of stemness-related markers (NANOG, OCT4, SOX2), ALDH activity, sphere-forming assay and subcutaneous tumor model in nude mice were performed to evaluate the stemness properties of esophageal cancer cells in vitro and in vivo. Dual-luciferase reporter assay was used to verify the molecular mechanism.

RESULT

Here we found that overexpression of miR-191-3p promoted the stemness properties of esophageal cancer cells in vitro and in vivo, including increasing esophageal cancer cell proliferation and metastasis ability, the expression of stemness-related markers NANOG, OCT4, and SOX2, ALDH activity, the number of spheres formed and tumor growth. Bioinformatic analysis and dual-luciferase assay demonstrated that regulator of G protein signaling 1 (RGS1) was the directed target gene of miR-191-3p and attenuated the promotion effect of miR-191-3p on the stemness of esophageal cancer cells. Furthermore, we found that RGS1 knockdown activated the PI3K/AKT pathway by negatively regulating CXCR4 to promote the stemness of esophageal cancer cells.

CONCLUSIONS

Our findings revealed that RGS1 targeted by miR-191-3p inhibited the stemness of esophageal cancer cells by suppressing the CXCR4/PI3K/AKT pathway, which provide potential prognostic markers and therapeutic targets in the future.

Targeted therapy of cancer stem cells: inhibition of mTOR in pre-clinical and clinical research

Cancer stem cells (CSCs) are a type of stem cell that possesses not only the intrinsic abilities of stem cells but also the properties of cancer cells. Therefore, CSCs are known to have self-renewal and outstanding proliferation capacity, along with the potential to differentiate into specific types of tumor cells. Cancers typically originate from CSCs, making them a significant target for tumor treatment. Among the related cascades of the CSCs, mammalian target of rapamycin (mTOR) pathway is regarded as one of the most important signaling pathways because of its association with significant upstream signaling: phosphatidylinositol 3‑kinase/protein kinase B (PI3K/AKT) pathway and mitogen‑activated protein kinase (MAPK) cascade, which influence various activities of stem cells, including CSCs. Recent studies have shown that the mTOR pathway not only affects generation of CSCs but also the maintenance of their pluripotency. Furthermore, the maintenance of pluripotency or differentiation into specific types of cancer cells depends on the regulation of the mTOR signal in CSCs. Consequently, the clinical potential and importance of mTOR in effective cancer therapy are increasing. In this review, we demonstrate the association between the mTOR pathway and cancer, including CSCs. Additionally, we discuss a new concept for anti-cancer drug development aimed at overcoming existing drawbacks, such as drug resistance, by targeting CSCs through mTOR inhibition.

Cancer Stem Cells in Oral Squamous Cell Carcinoma: A Narrative Review on Experimental Characteristics and Methodological Challenges

Cancer stem cells (CSCs) represent a subpopulation of cancer cells that are believed to initiate and drive cancer progression. In animal models, xenotransplanted CSCs have demonstrated the ability to produce tumors. Since their initial isolation in blood cancers, CSCs have been identified in various solid human cancers, including oral squamous cell carcinoma (OSCC). In addition to their tumorigenic properties, dysregulated stem-cell-related signaling pathways-Wnt family member (Wnt), neurogenic locus notch homolog protein (Notch), and hedgehog-have been shown to endow CSCs with characteristics like self-renewal, phenotypic plasticity, and chemoresistance, contributing to recurrence and treatment failure. Consequently, CSCs have become targets for new therapeutic agents, with some currently in different phases of clinical trials. Notably, small molecule inhibitors of the hedgehog signaling pathway, such as vismodegib and glasdegib, have been approved for the treatment of basal cell carcinoma and acute myeloid leukemia, respectively. Other strategies for eradicating CSCs include natural compounds, nano-drug delivery systems, targeting mitochondria and the CSC microenvironment, autophagy, hyperthermia, and immunotherapy. Despite the extensive documentation of CSCs in OSCC since its first demonstration in head and neck (HN) SCC in 2007, none of these novel pharmacological approaches have yet entered clinical trials for OSCC patients. This narrative review summarizes the in vivo and in vitro evidence of CSCs and CSC-related signaling pathways in OSCC, highlighting their role in promoting chemoresistance and immunotherapy resistance. Additionally, it addresses methodological challenges and discusses future research directions to improve experimental systems and advance CSC studies.

Cancer stem cells: advances in knowledge and implications for cancer therapy

Cancer stem cells (CSCs), a small subset of cells in tumors that are characterized by self-renewal and continuous proliferation, lead to tumorigenesis, metastasis, and maintain tumor heterogeneity. Cancer continues to be a significant global disease burden. In the past, surgery, radiotherapy, and chemotherapy were the main cancer treatments. The technology of cancer treatments continues to develop and advance, and the emergence of targeted therapy, and immunotherapy provides more options for patients to a certain extent. However, the limitations of efficacy and treatment resistance are still inevitable. Our review begins with a brief introduction of the historical discoveries, original hypotheses, and pathways that regulate CSCs, such as WNT/β-Catenin, hedgehog, Notch, NF-κB, JAK/STAT, TGF-β, PI3K/AKT, PPAR pathway, and their crosstalk. We focus on the role of CSCs in various therapeutic outcomes and resistance, including how the treatments affect the content of CSCs and the alteration of related molecules, CSCs-mediated therapeutic resistance, and the clinical value of targeting CSCs in patients with refractory, progressed or advanced tumors. In summary, CSCs affect therapeutic efficacy, and the treatment method of targeting CSCs is still difficult to determine. Clarifying regulatory mechanisms and targeting biomarkers of CSCs is currently the mainstream idea.

Deciphering the role of FUS::DDIT3 expression and tumor microenvironment in myxoid liposarcoma development

BACKGROUND

Myxoid liposarcoma (MLS) displays a distinctive tumor microenvironment and is characterized by the FUS::DDIT3 fusion oncogene, however, the precise functional contributions of these two elements remain enigmatic in tumor development.

METHODS

To study the cell-free microenvironment in MLS, we developed an experimental model system based on decellularized patient-derived xenograft tumors. We characterized the cell-free scaffold using mass spectrometry. Subsequently, scaffolds were repopulated using sarcoma cells with or without FUS::DDIT3 expression that were analyzed with histology and RNA sequencing.

RESULTS

Characterization of cell-free MLS scaffolds revealed intact structure and a large variation of protein types remaining after decellularization. We demonstrated an optimal culture time of 3 weeks and showed that FUS::DDIT3 expression decreased cell proliferation and scaffold invasiveness. The cell-free MLS microenvironment and FUS::DDIT3 expression both induced biological processes related to cell-to-cell and cell-to-extracellular matrix interactions, as well as chromatin remodeling, immune response, and metabolism. Data indicated that FUS::DDIT3 expression more than the microenvironment determined the pre-adipocytic phenotype that is typical for MLS.

CONCLUSIONS

Our experimental approach opens new means to study the tumor microenvironment in detail and our findings suggest that FUS::DDIT3-expressing tumor cells can create their own extracellular niche.

Germline Genetic Mutations in Adult Patients with Sarcoma: Insight into the Middle East Genetic Landscape

Data on germline mutations in soft tissue and bone sarcomas are scarce. We sought to identify the prevalence of germline mutations in adult sarcoma patients treated at a tertiary cancer center. Newly diagnosed patients were offered germline genetic testing via an 84-gene panel. The prevalence of pathogenic germline variants (PGVs) and their association with disease-, and patient- related factors are reported. A total of 87 patients were enrolled, the median age was 48 (19-78) years, and 47 (54%) were females. Gastrointestinal stromal tumors (n = 12, 13.8%), liposarcoma (n = 10, 11.5%), and Ewing sarcoma (n = 10, 11.5%) were the main subtypes. A total of 20 PGVs were detected in 18 (20.7%) patients. Variants of uncertain significance, in the absence of PGVs, were detected in 40 (45.9%) patients. Young age (p = 0.031), presence of a second primary cancer (p = 0.019), and female gender (p = 0.042) were correlated with the presence of PGVs. All identified PGVs have potential clinical actionability and cascade testing, and eight (44.44%) suggested eligibility for a targeted therapy. Almost one in five adult patients with soft tissue and bone sarcomas harbor pathogenic or likely pathogenic variants. Many of these variants are potentially actionable, and almost all have implications on cancer screening and family counselling. In this cohort from the Middle East, younger age, presence of a second primary tumor, and female gender were significantly associated with higher PGVs rates. Larger studies able to correlate treatment outcomes with genetic variants are highly needed.

Targeting signaling pathways in cancer stem cells: A potential approach for developing novel anti-cancer therapeutics

Cancer stem cells (CSCs) have emerged as prime players in the intricate landscape of cancer development, progression, and resistance to traditional treatments. These unique cellular subpopulations own the remarkable capability of self-renewal and differentiation, giving rise to the diverse cellular makeup of tumors and fostering their recurrence following conventional therapies. In the quest for developing more effective cancer therapeutics, the focus has now shifted toward targeting the signaling pathways that govern CSCs behavior. This chapter underscores the significance of these signaling pathways in CSC biology and their potential as pivotal targets for the development of novel chemotherapy approaches. We delve into several key signaling pathways essential for maintaining the defining characteristics of CSCs, including the Wnt, Hedgehog, Notch, JAK-STAT, NF-κB pathways, among others, shedding light on their potential crosstalk. Furthermore, we highlight the latest advancements in CSC-targeted therapies, spanning from promising preclinical models to ongoing clinical trials. A comprehensive understanding of the intricate molecular aspects of CSC signaling pathways and their manipulation holds the prospective to revolutionize cancer treatment paradigms. This, in turn, could lead to more efficacious and personalized therapies with the ultimate goal of eradicating CSCs and enhancing overall patient outcomes. The exploration of CSC signaling pathways represents a key step towards a brighter future in the battle against cancer.

JAK-STAT pathway inhibitors in dermatology

The JAK-STAT signaling pathway mediates important cellular processes such as immune response, carcinogenesis, cell differentiation, division and death. Therefore, drugs that interfere with different JAK-STAT signaling patterns have potential indications for various medical conditions. The main dermatological targets of JAK-STAT pathway inhibitors are inflammatory or autoimmune diseases such as psoriasis, vitiligo, atopic dermatitis and alopecia areata; however, several dermatoses are under investigation to expand this list of indications. As JAK-STAT pathway inhibitors should gradually occupy a relevant space in dermatological prescriptions, this review presents the main available drugs, their immunological effects, and their pharmacological characteristics, related to clinical efficacy and safety, aiming to validate the best dermatological practice.

Unmasking the Deceptive Nature of Cancer Stem Cells: The Role of CD133 in Revealing Their Secrets

Cancer remains a leading cause of death globally, and its complexity poses a significant challenge to effective treatment. Cancer stem cells and their markers have become key players in tumor growth and progression. CD133, a marker in various cancer types, is an active research area as a potential therapeutic target. This article explores the role of CD133 in cancer treatment, beginning with an overview of cancer statistics and an explanation of cancer stem cells and their markers. The rise of CD133 is discussed, including its structure, functions, and occurrence in different cancer types. Furthermore, the article covers CD133 as a therapeutic target, focusing on gene therapy, immunotherapy, and approaches to affect CD133 expression. Nanoparticles such as gold nanoparticles and nanoliposomes are also discussed in the context of CD133-targeted therapy. In conclusion, CD133 is a promising therapeutic target for cancer treatment. As research in this area progresses, it is hoped that CD133-targeted therapies will offer new and effective treatment options for cancer patients in the future.

Profiling and targeting cancer stem cell signaling pathways for cancer therapeutics

Tumorigenic cancer stem cells (CSCs) represent a subpopulation of cells within the tumor that express genetic and phenotypic profiles and signaling pathways distinct from the other tumor cells. CSCs have eluded many conventional anti-oncogenic treatments, resulting in metastases and relapses of cancers. Effectively targeting CSCs' unique self-renewal and differentiation properties would be a breakthrough in cancer therapy. A better characterization of the CSCs' unique signaling mechanisms will improve our understanding of the pathology and treatment of cancer. In this paper, we will discuss CSC origin, followed by an in-depth review of CSC-associated signaling pathways. Particular emphasis is given on CSC signaling pathways' ligand-receptor engagement, upstream and downstream mechanisms, and associated genes, and molecules. Signaling pathways associated with regulation of CSC development stand as potential targets of CSC therapy, which include Wnt, TGFβ (transforming growth factor-β)/SMAD, Notch, JAK-STAT (Janus kinase-signal transducers and activators of transcription), Hedgehog (Hh), and vascular endothelial growth factor (VEGF). Lastly, we will also discuss milestone discoveries in CSC-based therapies, including pre-clinical and clinical studies featuring novel CSC signaling pathway cancer therapeutics. This review aims at generating innovative views on CSCs toward a better understanding of cancer pathology and treatment.

ADAR1-mediated RNA editing of SCD1 drives drug resistance and self-renewal in gastric cancer

Targetable drivers governing 5-fluorouracil and cisplatin (5FU + CDDP) resistance remain elusive due to the paucity of physiologically and therapeutically relevant models. Here, we establish 5FU + CDDP resistant intestinal subtype GC patient-derived organoid lines. JAK/STAT signaling and its downstream, adenosine deaminases acting on RNA 1 (ADAR1), are shown to be concomitantly upregulated in the resistant lines. ADAR1 confers chemoresistance and self-renewal in an RNA editing-dependent manner. WES coupled with RNA-seq identify enrichment of hyper-edited lipid metabolism genes in the resistant lines. Mechanistically, ADAR1-mediated A-to-I editing on 3'UTR of stearoyl-CoA desaturase (SCD1) increases binding of KH domain-containing, RNA-binding, signal transduction-associated 1 (KHDRBS1), thereby augmenting SCD1 mRNA stability. Consequently, SCD1 facilitates lipid droplet formation to alleviate chemotherapy-induced ER stress and enhances self-renewal through increasing β-catenin expression. Pharmacological inhibition of SCD1 abrogates chemoresistance and tumor-initiating cell frequency. Clinically, high proteomic level of ADAR1 and SCD1, or high SCD1 editing/ADAR1 mRNA signature score predicts a worse prognosis. Together, we unveil a potential target to circumvent chemoresistance.

RANKL Promotes Chemotherapy Resistance in Breast Cancer Cells Through STAT3 Mediated Autophagy Induction

BACKGROUND

This study was to investigate the functional role and mechanism of receptor activator of nuclear factor-kappa B ligand (RANKL) associated autophagy and chemoresistance in breast cancer.

MATERIALS AND METHODS

Cell Counting Kit-8 (CCK-8) assay was used to detect the cell viability. Real-time polymerase chain reaction (PCR) was used for determining the relative mRNA levels of key genes and protein expression was assessed by Western blotting. Immunofluorescence was performed to evaluate the changes in the autophagy flux. Short hairpin (shRNA) was used to knockdown the expression of the target genes in breast cancer cells. Based on The Cancer Genome Atlas (TCGA) database, we explored the expression of receptor activator of nuclear factor-kappa B (RANK), autophagy and signal transducer and activator of transcription 3 (STAT3) signaling associated genes and analyzed their correlation with the prognosis of breast cancer patients.

RESULTS

The findings showed that receptor activator of nuclear factor-kappa B ligand (RANKL), the ligand of RANK, could effectively enhance the chemoresistance potential of breast cancer cells. Our results showed that RANKL induced autophagy and enhanced the expression of autophagy associated genes in breast cancer cells. The knockdown of RANK suppressed RANKL mediated autophagy induction in these cells. Furthermore, the inhibition of autophagy suppressed RANKL mediated chemoresistance in breast cancer cells. We found STAT3 signaling pathway was involved in RANKL-induced autophagy. Analysis of the expression of RANK, and autophagy and STAT3 signaling associated genes in breast cancer tissues showed that the expression of autophagy and STAT3 signaling associated genes was correlated with the prognosis of breast cancer patients.

CONCLUSION

The present study suggests that the RANKL/RANK axis may potentially mediate chemoresistance in breast cancer cells by inducing autophagy through the STAT3 signaling pathway.

Janus Kinase-Signal Transducer and Activator of Transcription Inhibitors for the Treatment and Management of Cancer

According to the World Health Organization (WHO), cancer is the second-highest cause of mortality worldwide, killing nearly 9.6 million people annually. Despite the advances in diagnosis and treatment during the last couple of decades, it remains a serious concern due to the limitations of currently available cancer management strategies. Therefore, alternative strategies are highly required to overcome these glitches. In addition, many etiological factors such as environmental and genetic factors initiate the activation of the Janus kinase (JAK)-signal transducer and activator of the transcription (STAT) pathway. This aberrant activation of the JAK-STAT pathway has been reported in various disease states, including inflammatory conditions, hematologic malignancies, and cancer. For instance, many patients with myeloproliferative neoplasms carry the acquired gain-of-function JAK2 V617F somatic mutation. This knowledge has dramatically improved our understanding of pathogenesis and has facilitated the development of therapeutics capable of suppressing the constitutive activation of the JAK-STAT pathway. Our aim is not to be expansive but to highlight emerging ideas towards preventive therapy in a modern view of JAK-STAT inhibitors. A series of agents with different specificities against different members of the JAK family of proteins is currently undergoing evaluation in clinical trials. Here we give a summary of how JAK-STAT inhibitors function and a detailed review of current clinical drugs for managing cancer as a new therapeutic approach.

Cancer plasticity: Investigating the causes for this agility

Cancer is not a hard-wired phenomenon but an evolutionary disease. From the onset of carcinogenesis, cancer cells continuously adapt and evolve to satiate their ever-growing proliferation demands. This results in the formation of multiple subtypes of cancer cells with different phenotypes, cellular compositions, and consequently displaying varying degrees of tumorigenic identity and function. This phenomenon is referred to as cancer plasticity, during which the cancer cells exist in a plethora of cellular states having distinct phenotypes. With the advent of modern technologies equipped with enhanced resolution and depth, for example, single-cell RNA-sequencing and advanced computational tools, unbiased cancer profiling at a single-cell resolution are leading the way in understanding cancer cell rewiring both spatially and temporally. In this review, the processes and mechanisms that give rise to cancer plasticity include both intrinsic genetic factors such as epigenetic changes, differential expression due to changes in DNA, RNA, or protein content within the cancer cell, as well as extrinsic environmental factors such as tissue perfusion, extracellular milieu are detailed and their influence on key cancer plasticity hallmarks such as epithelial-mesenchymal transition (EMT) and cancer cell stemness (CSCs) are discussed. Due to therapy evasion and drug resistance, tumor heterogeneity caused by cancer plasticity has major therapeutic ramifications. Hence, it is crucial to comprehend all the cellular and molecular mechanisms that control cellular plasticity. How this process evades therapy, and the therapeutic avenue of targeting cancer plasticity must be diligently investigated.

Signaling pathways in the regulation of cancer stem cells and associated targeted therapy

Cancer stem cells (CSCs) are defined as a subpopulation of malignant tumor cells with selective capacities for tumor initiation, self-renewal, metastasis, and unlimited growth into bulks, which are believed as a major cause of progressive tumor phenotypes, including recurrence, metastasis, and treatment failure. A number of signaling pathways are involved in the maintenance of stem cell properties and survival of CSCs, including well-established intrinsic pathways, such as the Notch, Wnt, and Hedgehog signaling, and extrinsic pathways, such as the vascular microenvironment and tumor-associated immune cells. There is also intricate crosstalk between these signal cascades and other oncogenic pathways. Thus, targeting pathway molecules that regulate CSCs provides a new option for the treatment of therapy-resistant or -refractory tumors. These treatments include small molecule inhibitors, monoclonal antibodies that target key signaling in CSCs, as well as CSC-directed immunotherapies that harness the immune systems to target CSCs. This review aims to provide an overview of the regulating networks and their immune interactions involved in CSC development. We also address the update on the development of CSC-directed therapeutics, with a special focus on those with application approval or under clinical evaluation.

Properties of Leukemic Stem Cells in Regulating Drug Resistance in Acute and Chronic Myeloid Leukemias

Notoriously known for their capacity to reconstitute hematological malignancies in vivo, leukemic stem cells (LSCs) represent key drivers of therapeutic resistance and disease relapse, posing as a major medical dilemma. Despite having low abundance in the bulk leukemic population, LSCs have developed unique molecular dependencies and intricate signaling networks to enable self-renewal, quiescence, and drug resistance. To illustrate the multi-dimensional landscape of LSC-mediated leukemogenesis, in this review, we present phenotypical characteristics of LSCs, address the LSC-associated leukemic stromal microenvironment, highlight molecular aberrations that occur in the transcriptome, epigenome, proteome, and metabolome of LSCs, and showcase promising novel therapeutic strategies that potentially target the molecular vulnerabilities of LSCs.

Synchrotron Fourier Transform Infrared Microscopy Spectra in Cellular Effects of Janus Kinase Inhibitors on Myelofibrosis Cancer Cells

Janus kinase (JAK) deregulation of the JAK/signal transducers and activators of transcription pathway leads to myelofibrosis that can be treated by JAK inhibitors including Ruxolitinib and Tofacitinib. Even though both inhibitors are effective against myelofibrosis, each of them has a different mode of action in the cells. Ruxolitinib is an inhibitor for selective JAK1/2, and Tofacitinib is an inhibitor for JAK3. This study evaluated the chemical fingerprints of TF-1 cells after JAK inhibitor treatments by the synchrotron Fourier transform infrared microspectroscopy (S-FTIR) spectrum. Tofacitinib and Ruxolitinib treatments in TF-1 cells were applied with a chemical fingerprint approach in S-FTIR spectroscopy and in vitro cytotoxicity in a cell-based assay. Principal component analysis or PCA was utilized to classify three cell treatments with three biochemical alteration absorbances of lipid vibration by the C-H stretching, protein amide I that appeared from the C=O stretching, and a P=O phosphodiester bond from nucleic acids. The results showed that the inhibition effect of Ruxolitinib on the TF-1 cell lines was two-fold higher than Tofacitinib. PCA distinguishes untreated and drug-treated cells by detecting cellular biochemical alteration. The loading plots identify that proteins and nucleic acids were the different main components in disparate cell treatments. Tofacitinib was distinct from the others in lipid and nucleic acid. The second derivative spectra of the three molecular components had decreased lipid production and accumulation, changes in secondary structures in proteins, and a high level of RNA overexpression in cell treatment. The JAK inhibitors caused different spectroscopic biomarkers of the modifications of secondary protein conformation, stimulated cell lipid accumulation, and phosphorylation from untreated cells. The alteration of cellular biochemical components suggests that FTIR is a potential tool to analyze specific patterns of drug cellular responses at the molecular level.

Complex Elucidation of Cells-of-Origin in Pediatric Soft Tissue Sarcoma: From Concepts to Real Life, Hide-and-Seek through Epigenetic and Transcriptional Reprogramming

Soft tissue sarcoma (STS) comprise a large group of mesenchymal malignant tumors with heterogeneous cellular morphology, proliferative index, genetic lesions and, more importantly, clinical features. Full elucidation of this wide diversity remains a central question to improve their therapeutic management and the identity of cell(s)-of-origin from which these tumors arise is part of this enigma. Cellular reprogramming allows transitions of a mature cell between phenotypes, or identities, and represents one key driver of tumoral heterogeneity. Here, we discuss how cellular reprogramming mediated by driver genes in STS can profoundly reshape the molecular and morphological features of a transformed cell and lead to erroneous interpretation of its cell-of-origin. This review questions the fact that the epigenetic context in which a genetic alteration arises has to be taken into account as a key determinant of STS tumor initiation and progression. Retracing the cancer-initiating cell and its clonal evolution, notably via epigenetic approach, appears as a key lever for understanding the origin of these tumors and improving their clinical management.

The Interaction Between Autophagy and JAK/STAT3 Signaling Pathway in Tumors

Tumor is one of the important factors affecting human life and health in today’s world, and scientists have studied it extensively and deeply, among which autophagy and JAK/STAT3 signaling pathway are two important research directions. The JAK/STAT3 axis is a classical intracellular signaling pathway that assumes a key role in the regulation of cell proliferation, apoptosis, and vascular neogenesis, and its abnormal cell signaling and regulation are closely related to the occurrence and development of tumors. Therefore, the JAK/STAT3 pathway in tumor cells and various stromal cells in their microenvironment is often considered as an effective target for tumor therapy. Autophagy is a process that degrades cytoplasmic proteins and organelles through the lysosomal pathway. It is a fundamental metabolic mechanism for intracellular degradation. The mechanism of action of autophagy is complex and may play different roles at various stages of tumor development. Altered STAT3 expression has been found to be accompanied by the abnormal autophagy activity in many oncological studies, and the two may play a synergistic or antagonistic role in promoting or inhibiting the occurrence and development of tumors. This article reviews the recent advances in autophagy and its interaction with JAK/STAT3 signaling pathway in the pathogenesis, prevention, diagnosis, and treatment of tumors.

Exosome-based nanomedicine for cancer treatment by targeting inflammatory pathways: Current status and future perspectives

Cancer is one of the dreadful diseases worldwide. Surgery, radiation and chemotherapy, are the three basic standard modes of cancer treatment. However, difficulties in cancer treatment are increasing due to immune escape, spreading of cancer to other places, and resistance of cancer cells to therapies. Various signaling mechanisms, including PI3K/Akt/mTOR, RAS, WNT/β-catenin, TGF-beta, and notch pathways, are involved in cancer resistance. The adaptive inflammatory response is the initial line of defence against infection. However, chronic inflammation can lead to tumorigenesis, malignant transformation, tumor growth, invasion, and metastasis. The most commonly dysregulated inflammatory pathways linked to cancer include NF-κB, MAPK, JAK-STAT, and PI3K/AKT. To overcome major hurdles in cancer therapy, nanomedicine is receiving much attention due to its role as a vehicle for delivering chemotherapeutic agents that specifically target tumor sites. Several biocompatible nanocarriers including polymer and inorganic nanoparticles, liposomes, micellar nanoparticles, nanotubes, and exosomes have been extensively studied. Exosome has been reported as an important potential sytem that could be effectively used as a bioinspired, bioengineered, and biomimetic drug delivery solution considering its toxicity, immunogenicity, and rapid clearance by the mononuclear phagocyte system. Exosome-mimetic vesicles are receiving much interest for developing nano-sized delivery systems. In this review, exosomes in detail as well as certain other nanocarriers, and their potential therapeutic roles in cancer therapy has been thoroughly discussed. Additionally, we also reviewed on oncogenic and tumor suppressor proteins, inflammation, and their associated signaling pathways and their interference by exosomes based nanomedicine.

FUS-DDIT3 Fusion Oncoprotein Expression Affects JAK-STAT Signaling in Myxoid Liposarcoma

Myxoid liposarcoma is one of the most common sarcoma entities characterized by FET fusion oncogenes. Despite a generally favorable prognosis of myxoid liposarcoma, chemotherapy resistance remains a clinical problem. This cancer stem cell property is associated with JAK-STAT signaling, but the link to the myxoid-liposarcoma-specific FET fusion oncogene FUS-DDIT3 is not known. Here, we show that ectopic expression of FUS-DDIT3 resulted in elevated levels of STAT3 and phosphorylated STAT3. RNA sequencing identified 126 genes that were regulated by both FUS-DDIT3 expression and JAK1/2 inhibition using ruxolitinib. Sixty-six of these genes were connected in a protein interaction network. Fifty-three and 29 of these genes were confirmed as FUS-DDIT3 and STAT3 targets, respectively, using public chromatin immunoprecipitation sequencing data sets. Enriched gene sets among the 126 regulated genes included processes related to cytokine signaling, adipocytokine signaling, and chromatin remodeling. We validated CD44 as a target gene of JAK1/2 inhibition and as a potential cancer stem cell marker in myxoid liposarcoma. Finally, we showed that FUS-DDIT3 interacted with phosphorylated STAT3 in association with subunits of the SWI/SNF chromatin remodeling complex and PRC2 repressive complex. Our data show that the function of FUS-DDIT3 is closely connected to JAK-STAT signaling. Detailed deciphering of molecular mechanisms behind tumor progression opens up new avenues for targeted therapies in sarcomas and leukemia characterized by FET fusion oncogenes.

Cancer stem cells: a major culprit of intra-tumor heterogeneity

Cancer is recognized as a preeminent factor of the world's mortality. Although various modalities have been designed to cure this life-threatening ailment, a significant impediment in the effective output of cancer treatment is heterogeneity. Cancer is characterized as a heterogeneous health disorder that comprises a distinct group of transformed cells to assist anomalous proliferation of affected cells. Cancer stem cells (CSCs) are a leading cause of cancer heterogeneity that is continually transformed by cellular extrinsic and intrinsic factors. They intensify neoplastic cells aggressiveness by strengthening their dissemination, relapse and therapy resistance. Considering this viewpoint, in this review article we have discussed some intrinsic (transcription factors, cell signaling pathways, genetic alterations, epigenetic modifications, non-coding RNAs (ncRNAs) and epitranscriptomics) and extrinsic factors (tumor microenvironment (TME)) that contribute to CSC heterogeneity and plasticity, which may help scientists to meddle these processes and eventually improve cancer research and management. Besides, the potential role of CSCs heterogeneity in establishing metastasis and therapy resistance has been articulated which signifies the importance of developing novel anticancer therapies to target CSCs along with targeting bulk tumor mass to achieve an effective output.

Molecular targeted therapy for advanced or metastatic soft tissue sarcoma

Soft tissue sarcomas are a form of rare and heterogeneous neoplasms with high recurrence rate and mortality. Over the past decades, less progress has been achieved. Surgical management with or without adjuvant/neoadjuvant radiotherapy is still the first-line treatment for localized soft tissue sarcomas, and chemotherapy is the additional option for those with high-risk. However, not all patients with advanced or metastatic soft tissue sarcomas benefit from conventional chemotherapy, targeted therapy takes the most relevant role in the management of those resistant to or failed to conventional chemotherapy. Heterogeneous soft tissue sarcomas vary from biological behavior, genetic mutations, and clinical presentation with a low incidence, indicating the future direction of histotype-based even molecule-based personalized therapy. Furthermore, increasing preclinical studies were carried out to investigate the pathogenesis and potential therapeutic targets of soft tissue sarcomas and increasing new drugs have been developed in recent years, which had started opening new doors for clinical treatment for patients with advanced/metastatic soft tissue sarcomas. Here we sought to summarize the concise characteristics and advance in the targeted therapy for the most common subtypes of soft tissue sarcomas.

JAK2 regulates paclitaxel resistance in triple negative breast cancers

We investigated the molecular mechanisms of paclitaxel resistance in TNBC using seven patient-derived xenograft (PDX) models and TNBC cell lines. Among the seven PDX models, four models showed resistance to paclitaxel. Dysregulation of JAK/STAT pathways and JAK2 copy number gains were observed in the four paclitaxel-resistant PDX tumors. In TNBC cell lines, silencing the JAK2 gene showed a significant but mild synergistic effect when combined with paclitaxel in vitro. However, JAK1/2 inhibitor treatment resulted in restoration of paclitaxel sensitivity in two out of four paclitaxel-resistant PDX models and JAK1/2 inhibitor alone significantly suppressed the tumor growth in one out of the two remaining PDX models. Transcriptome data derived from the murine microenvironmental cells revealed an enrichment of genes involved in the cell cycle processes among the four paclitaxel-resistant PDX tumors. Histologic examination of those PDX tumor tissues showed increased Ki67-positive fibroblasts in the tumor microenvironment. Among the four different cancer-associated fibroblast (CAF) subtypes, cycling CAF exhibiting features of active cell cycle was enriched in the paclitaxel-resistant PDX tumors. Additionally, fibroblasts treated with the conditioned media from the JAK2-silenced breast cancer cells showed downregulation of cell cycle-related genes. Our data suggest that the JAK2 gene may play a critical role in determining responses of TNBC to paclitaxel by modulating the intrinsic susceptibility of cancer cells against paclitaxel and also by eliciting functional transitions of CAF subtypes in the tumor microenvironment. KEY MESSAGES : We investigated the molecular mechanisms of paclitaxel resistance in TNBC. JAK2 signaling was associated with paclitaxel resistance in TNBC PDX models. Paclitaxel-resistant PDX tumors were enriched with microenvironment cCAF subpopulation. JAK2 regulated paclitaxel-resistant CAF phenotype transition.

Impact of STAT Proteins in Tumor Progress and Therapy Resistance in Advanced and Metastasized Prostate Cancer

Signal transducers and activators of transcription (STATs) are a family of transcription factors involved in several biological processes such as immune response, cell survival, and cell growth. However, they have also been implicated in the development and progression of several cancers, including prostate cancer (PCa). Although the members of the STAT protein family are structurally similar, they convey different functions in PCa. STAT1, STAT3, and STAT5 are associated with therapy resistance. STAT1 and STAT3 are involved in docetaxel resistance, while STAT3 and STAT5 are involved in antiandrogen resistance. Expression of STAT3 and STAT5 is increased in PCa metastases, and together with STAT6, they play a crucial role in PCa metastasis. Further, expression of STAT3, STAT5, and STAT6 was elevated in advanced and high-grade PCa. STAT2 and STAT4 are currently less researched in PCa. Since STATs are widely involved in PCa, they serve as potential therapeutic targets. Several inhibitors interfering with STATs signaling have been tested unsuccessfully in PCa clinical trials. This review focuses on the respective roles of the STAT family members in PCa, especially in metastatic disease and provides an overview of STAT-inhibitors evaluated in clinical trials.

STAT3 is required for Smo-dependent signaling and mediates Smo-targeted treatment resistance and tumorigenesis in Shh medulloblastoma

Sonic hedgehog (Shh)‐driven medulloblastoma (Shh MB) cells are dependent on constitutive Shh signaling, but targeted treatment of Shh MB has been ineffective due to drug resistance. The purpose of this study was to address the critical role of signal transducer and activator of transcription 3 (STAT3) in Shh signaling and drug resistance in Shh MB cells. Herein, we show that STAT3 is required for Smoothened (Smo)‐dependent Shh signaling and, in turn, is reciprocally regulated by Shh signaling, and demonstrate that STAT3 activity is critical for expression of HCK proto‐oncogene, Src family tyrosine kinase (Hck) in Shh MB. We also demonstrate that maintained STAT3 activity suppresses p21 expression and promotes colony formation of Shh MB cells, whereas dual treatment with inhibitors of both Smo and STAT3 results in marked synergistic killing and overcomes drug resistance in vitro of Smo antagonist‐resistant Shh MB cells. Finally, STAT3 inhibitor treatment significantly prevents in vivo tumor formation in genetically engineered Shh MB mice. Collectively, we show that STAT3 is necessary to maintain Shh signaling and thus is a potential therapeutic target to treat Shh MB and overcome anti‐Smo drug resistance.

miRNA signaling networks in cancer stem cells

Cancer stem cells (CSCs) are a small cell subpopulation in many cancer types and are involved in various processes of tumor progression, such as initiation, metastasis and recurrence. The distinguished features of CSCs include a variety of biological properties, including self-renewal, multidifferentiation, stemness marker expression, and resistance to chemotherapy and radiotherapy. Despite their great potential of clinical importance, the CSC signaling pathways are not well understood at the molecular level. MicroRNAs (miRNAs) are a class of endogenous noncoding RNAs that play an important role in the regulation of several cellular, physiological, and developmental processes. Aberrant miRNA expression is associated with many human diseases, including cancer. miRNAs have been implicated in the regulation of CSC properties; therefore, a better understanding of miRNA-induced modulation of CSC gene expression could aid in the identification of promising biomarkers and therapeutic targets. In the present review, we summarize the major findings of the impacts of miRNAs on CSC signaling networks; we then discuss the recent advances that have improved our understanding of CSC regulation by miRNA-mediated signaling networks and that may lead to the development of miRNA therapeutics specifically targeting CSCs.

Clinical and In Silico Outcomes of the Expression of miR-130a-5p and miR-615-3p in Tumor Compared with Non-Tumor Adjacent Tissues of Patients with BC

BACKGROUND

Breast Cancer (BC) is the most common malignancy among women with a high mortality rate. The blockade of asparagine-related pathways may be an effective measure to control the progression and reduction of BC metastasis potential. Recently, it has been shown that various miRNAs, as part of small non-coding RNAs, have a great role in cancer development, especially asparagine-related pathways, to modulate the invasiveness.

OBJECTIVE

This study aimed to evaluate the expression of miR-130a-5p and miR-615-3p in tumoral and nontumoral adjacent tissues of patients with BC.

METHODS

There is a chance that asparagine metabolism is influenced by miR-130a-5p and miR-615-3p as confirmed by bioinformatics analysis. Hence, real-time PCR was conducted on eighty BC tumoral and non-tumoral adjacent tissues to evaluate the expression level of the two miRNAs. To predict the potential biological process and molecular pathways of miR-130a-5p, an in silico analysis was performed.

RESULTS

This study indicated that miR-130a was downregulated in tumoral tissues compared to non-tumoral adjacent tissues (P-value= 0.01443 and fold change= -2.5137), while miR-615-3p did not show a significant difference between the two groups. Furthermore, the subgroup studies did not reveal any significant correlation between the expression of these two miRNAs and subfactors. Furthermore, in silico studies unraveled several biological processes related to amino-acid metabolism, as well as pathways related to tumor development such as Phosphatase and Tensin Homolog (PTEN) and JAK-STAT pathways among miR-130a-5p target genes.

CONCLUSION

Our findings indicate that miRNA-130a-5p is downregulated in BC tissues and may play a tumor suppressor role in patients with BC. Therefore, it may be suggested as a potential diagnostic and therapeutic target for BC.

ENC1 Facilitates Colorectal Carcinoma Tumorigenesis and Metastasis via JAK2/STAT5/AKT Axis-Mediated Epithelial Mesenchymal Transition and Stemness

Ectodermal neural cortex 1 (ENC1) is an actin-binding protein and has been known to be upregulated in several cancers, but the molecular mechanisms through which it contributes to the pathology of CRC have largely been elusive. We utilized data mining and validated the aberrant expression of ENC1, following which phenotypic traits of malignancy were assessed in vitro. Ruxolitinib was used as a surrogate to compare the effects of ENC1 expression and silencing on the JAK-STAT-AKT pathway. In vivo models were employed to confirm the in vitro observations. Computation analysis, strengthened by in situ and in vitro data, confirmed the overexpression of ENC1 in CRC and predicted a poor prognosis, while enhanced cell proliferation, invasion, migration, EMT, and stemness were associated with ENC1 overexpression. Silencing of ENC1 downregulated the phenotypes. Additionally, silencing of ENC1 significantly reduced the activation of JAK2 and consequent activation of STAT5 and AKT comparable to ruxolitinib inhibition of JAK2. Silencing of ENC1 resulted in lesser tumor volumes and fewer numbers of tumors, in vivo. These data suggest that ENC1 induces CRC through the JAK2-STAT5-AKT axis. ENC1 is a suitable diagnostic marker for CRC detection, and ENC1 targeting therapies may suppress CRC progression.

Hispidulin: A promising flavonoid with diverse anti-cancer properties

In recent years, natural products have increasingly attracted more attention because of their potential anticancer activity and low intrinsic toxicity. Hispidulin is a natural flavonoid with a wide range of biological activities, including anti-inflammatory, antifungal, antiplatelet, anticonvulsant, anti-osteoporotic, and notably anticancer activities. Numerous in vivo and in vitro studies have shown that hispidulin, as a potential anticancer drug, affects cell proliferation, apoptosis, cell cycle, angiogenesis, and metastasis. Moreover, hispidulin exhibits synergistic anti-tumor effects when combined with some common clinical anticancer drugs (e.g., gemcitabine, 5-fluoroucil, sunitinib, temozolomide, and TRAIL). The combination of hispidulin and chemotherapeutic drugs reduces the efflux of chemotherapeutic drugs, enhances the chemosensitivity of cancer cells, and reverses drug resistance. Herein, we outlined the anticancer effects of hispidulin in various cancers and its intracellular molecular targets and related mechanisms of its anticancer activity. Based on the available literature, it can be established that hispidulin has significant potential to become an important complementary medicine for cancer prevention and treatment. However, more in-depth in vitro and in vivo studies should be conducted to support its translation from bench to bedside.

RAC3 Promotes Proliferation, Migration and Invasion via PYCR1/JAK/STAT Signaling in Bladder Cancer

Background

Bladder cancer (BCa) represents one of the most common malignant cancers with high incidence and mortality rates globally. Dysregulation of gene expression has been shown to play critical roles in cancer progression. RAC3 is up-regulated to play an oncogenic role in several cancers, however, the underlying mechanism of RAC3 in BCa is yet to be elucidated. Therefore, this study aimed to investigate the function and mechanism of RAC3 in BCa.

Methods

Bioinformatics analysis was employed to demonstrate the expression of RAC3 and PYCR1 in BCa tissues, as well as, its correlation with the overall survival rate of BCa patients. RT-qPCR was performed to detect and quantify the mRNA levels of RAC3 and PYCR1 in BCa cells and immortalized human bladder epithelial cells. MTT, colony formation and Transwell assays were employed to determine cell proliferation, migration, and invasion. Western blotting was performed to detect and quantity proteins expressed.

Results

Bioinformatics analysis showed that RAC3 was up-regulated in BCa tissues when compared to normal tissues. Patients with up-regulated RAC3 expression had lower overall survival than patients with down-regulated RAC3 expression. The mRNA level of RAC3 was higher in BCa cells than in immortalized human bladder epithelial cell. RAC3 promoted cell proliferation, migration, and invasion by activating Janus kinases (JAKs) and signal transducers and activators of transcription (STATs) signaling. Notably, RAC3 up-regulated PYCR1, which is positively correlated with RAC3, and thus played an oncogenic role in BCa cells. Moreover, we demonstrated that RAC3 overexpression activated JAK/STAT signaling via PYCR1 axis.

Conclusion

RAC3 promoted cell proliferation, migration, and invasion. This is likely due to its role in activating JAK/STAT signaling, which was mediated by PYCR1. This study provides a novel biomarker and target for diagnostic or therapeutic intervention for BCa.

Targeting the JAK/STAT pathway in solid tumors

Aberrant activation of signal transducer and activator of transcription (STAT) proteins is associated with the development and progression of solid tumors. However, as transcription factors, these proteins are difficult to target directly. In this review, we summarize the role of targeting Janus kinases (JAKs), upstream activators of STATs, as a strategy for decreasing STAT activation in solid tumors. Preclinical studies in solid tumor cell line models show that JAK inhibitors decrease STAT activation, cell proliferation, and cell survival; in in vivo models, they also inhibit tumor growth. JAK inhibitors, particularly the JAK1/2 inhibitor ruxolitinib, sensitize cell lines and murine models to chemotherapy, immunotherapy, and oncolytic viral therapy. Ten JAK inhibitors have been or are actively being tested in clinical trials as monotherapy or in combination with other agents in patients with solid tumors; two of these inhibitors are already Food and Drug Administration (FDA) approved for the treatment of myeloproliferative disorders and rheumatoid arthritis, making them attractive agents for use in patients with solid tumors as they are known to be well-tolerated. Four JAK inhibitors (two of which are FDA approved for other indications) have exhibited promising anti-cancer effects in preclinical studies; however, clinical studies specifically assessing their activity against the JAK/STAT pathway in solid tumors have not yet been conducted. In summary, JAK inhibition is a viable option for targeting the JAK/STAT pathway in solid tumors and merits further testing in clinical trials.

miR-182-5p inhibits the pathogenic Th17 response in experimental autoimmune uveitis mice via suppressing TAF15

BACKGROUND

CD4⁺ T helper 17 (Th17) cells play a contributory role in uveitis and other autoimmune disorders. However, less is understood about the contribution of microRNAs (miRNAs) in regulating the pathogenic Th17 response in uveitis.

METHODS

The in vivo experimental autoimmune uveitis (EAU) model was constructed in female C57BL/6 mice. Primary EAU mouse CD4⁺ T-cells and the murine T-cell line EL4 were used for in vitro experiments. miRNA mimic/inhibitor, lentiviral overexpression plasmids, and small interfering RNAs (siRNAs) were used to modulate miR-182-5p and TAF15 expression. CD4⁺ T-cells from healthy controls (HC, n = 15), active Behçet's disease with uveitis (BD, n = 15), or active sympathetic ophthalmia with uveitis (SO, n = 15) were analyzed for miR-182-5p, TAF15, and Th17 marker gene expression.

RESULTS

miR-182-5p was downregulated in EAU mouse-derived Th17 cells. miR-182-5p negatively regulated Th17 cell development in vitro. miR-182-5p mimic therapy in transplanted Th17 cells ameliorated EAU severity in vivo. Mechanistically, miR-182-5p directly inhibited the transcriptional initiator TATA-binding protein-associated factor 15 (TAF15, TAFII68). miR-182-5p's inhibition of TAF15 negatively regulated Th17 cell development by suppressing STAT3 phosphorylation. TAF15 and Th17 marker expression were positively correlated in CD4⁺ T-cells from BD and SO patients.

CONCLUSION

miR-182-5p mimic therapy inhibits the pathogenic Th17 response in EAU mice. miR-182-5p's inhibition of TAF15 negatively regulates Th17 cell development by suppressing STAT3 phosphorylation. As TAF15 shows a positive relationship with Th17 cell markers in uveitis patients, the miR-182-5p/TAF15 axis shows promise as a therapeutic target for uveitis.

Modeling neoplastic disease with spheroids and organoids

Cancer is a complex disease in which both genetic defects and microenvironmental components contribute to the development, progression, and metastasization of disease, representing major hurdles in the identification of more effective and safer treatment regimens for patients. Three-dimensional (3D) models are changing the paradigm of preclinical cancer research as they more closely resemble the complex tissue environment and architecture found in clinical tumors than in bidimensional (2D) cell cultures. Among 3D models, spheroids and organoids represent the most versatile and promising models in that they are capable of recapitulating the heterogeneity and pathophysiology of human cancers and of filling the gap between conventional 2D in vitro testing and animal models. Such 3D systems represent a powerful tool for studying cancer biology, enabling us to model the dynamic evolution of neoplastic disease from the early stages to metastatic dissemination and the interactions with the microenvironment. Spheroids and organoids have recently been used in the field of drug discovery and personalized medicine. The combined use of 3D models could potentially improve the robustness and reliability of preclinical research data, reducing the need for animal testing and favoring their transition to clinical practice. In this review, we summarize the recent advances in the use of these 3D systems for cancer modeling, focusing on their innovative translational applications, looking at future challenges, and comparing them with most widely used animal models.

Cancer Stem Cells in Soft-Tissue Sarcomas

Soft tissue sarcomas (STS) are a rare group of mesenchymal solid tumors with heterogeneous genetic profiles and clinical features. Systemic chemotherapy is the backbone treatment for advanced STS; however, STS frequently acquire resistance to standard therapies, which highlights the need to improve treatments and identify novel therapeutic targets. Increases in the knowledge of the molecular pathways that drive sarcomas have brought to light different molecular alterations that cause tumor initiation and progression. These findings have triggered a breakthrough of targeted therapies that are being assessed in clinical trials. Cancer stem cells (CSCs) exhibit mesenchymal stem cell (MSC) features and represent a subpopulation of tumor cells that play an important role in tumor progression, chemotherapy resistance, recurrence and metastasis. In fact, CSCs phenotypes have been identified in sarcomas, allied to drug resistance and tumorigenesis. Herein, we will review the published evidence of CSCs in STS, discussing the molecular characteristic of CSCs, the commonly used isolation techniques and the new possibilities of targeting CSCs as a way to improve STS treatment and consequently patient outcome.

Role of VHL-JAK-STAT signaling pathway in central nervous system hemangioblastoma associated with von Hippel-Lindau disease

INTRODUCTION

Central nervous system hemangioblastoma is a benign tumor associated with or without von Hippel-Lindau (VHL) disease which is an autosomal dominant hereditary disease that results from a germline mutation in the VHL gene. A main axis of signaling pathways in central nervous system hemangioblastoma is VHL-HIF signaling pathway. Here, we propose an alternative VHL-JAK-STAT signaling pathway in hemangioblastoma and discuss the role.

METHODS

Using MACS method, Scl⁺ hemangioblast-like cells were isolated from multipotent nestin-expressing stem cells. Then, ubiquitination of JAK2 in those cells and immunoprecipitation between JAK2 and VHL were examined. Then, expressions of JAK2 and STAT3 in those cells and expressions of VHL-associated hemangioblastoma tissues were examined. In addition, the VHL genes of patients bearing hemangioblastoma were analyzed.

RESULTS

JAK2 and STAT3 in Scl⁺ hemangioblast-like cells were ubiquitinated after VHL- expression vector was transferred to those cells. Expressions of JAK2 and STAT3 in those cells were well recognized before the transfer, but those disappeared after the transfer. Expressions of both JAK2 and STAT3 in hemangioblastoma tissues were well shown. The VHL gene analysis revealed that patients bearing hemangioblastoma carried missense mutations in 5, small deletions in 2, large deletions in 4, and nonsense mutation in 1 CONCLUSIONS: VHL-JAK-STAT signaling pathway might play an important role in proliferation, angiogenesis, and maintenance of stem-cell-nature in hemangioblastoma as an alternative signaling pathway to supplement VHL-HIF signaling pathway.

Overexpression of LINC00691 promotes the proliferation and invasion of gastric cancer cells via the Janus kinase/signal transducer and activator of transcription signalling pathway

This report aims to explore how LINC00691 regulates the proliferation and invasion of gastric cancer (GC). Clinical tissue and serum samples, as well as specimens in the Cancer Genome Atlas (TCGA) database, were used to analyse the expression of LINC00691 in GC. Our data indicated that the expression of LINC00691 in GC was significantly higher than that in healthy controls and was associated with clinicopathological features and survival time. In the GC cell lines MKN-45 and HGC-27, the knockdown of LINC00691 suppressed proliferation, colony formation, migration, and invasion. Bioinformatics analysis and luciferase reporter gene experiments showed that LINC00691 activated Lin28 transcription. Western blot analysis indicated that the knockdown of LINC00691 contributed to the decreased expression of p-JAK2 and p-STAT3 in GC cells. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway inhibitor ruxolitinib effectively suppressed the effects of LINC00691. In addition, both LINC00691 and Lin28 promoted the expression of epidermal growth factor (EGF). Therefore, our study clarified that LINC00691 is highly expressed in GC and is a potential biomarker for GC diagnosis and prognosis. LINC00691 promotes the proliferation and invasion of GC cells by activating Lin28 transcription and facilitating EGF expression through the JAK/STAT signalling pathway, which provides new ideas for targeted therapy of GC.

[Overexpression of leukemia inhibitory factor enhances chemotherapy tolerance of endometrial cancer cells in vitro]

OBJECTIVE

To investigate the effect of overexpression of leukemia inhibitory factor (LIF) on cisplatin and paclitaxel resistance of endometrial cancer cells in vitro.

METHODS

Endometrial cancer cell lines HEC-1B and RL95-2 were infected with a recombinant lentivirus to overexpress LIF, and the changes in LIF expression was verified using RT-qPCR and ELISA. The viability of the LIF-overexpressing cells was assessed using CCK-8 assay, and the cell apoptosis and changes in mitochondrial membrane potential in response to cisplatin or paclitaxel treatment were analyzed with annexin V-FITC/PI staining and JC-1 assay, respectively. The effect of LIF overexpression on the expressions of Bcl-2 family proteins and STAT3 pathway was evaluated using Western blotting; dual-luciferase reporter gene assay was employed to detect the transcriptional activity of STAT3. The effect of STAT3 silencing on apoptosis of the LIF-overexpressing cells induced by cisplatin or paclitaxel was investigated.

RESULTS

The cell lines infected with the recombinant lentivirus showed significantly increased mRNA and protein levels of LIF (P < 0.05) without obvious changes in the cell viability (P>0.05). LIF overexpression significantly attenuated cisplatin-or paclitaxel-induced apoptosis of the endometrial cancer cells (P < 0.05) and markedly increased mitochondrial membrane potential of the cells (P < 0.05). The expressions of Bcl-2, Bcl-xL and p-STAT3 proteins increased obviously while the expressions of Bax, Bad and STAT3 either decreased or showed no obvious changes in the LIF-overexpressing cells. Overexpressing LIF significantly enhanced the transcriptional activity of STAT3 (P < 0.05), and silencing STAT3 obviously enhanced apoptosis of the endometrial cancer cells overexpressing LIF (P < 0.05).

CONCLUSIONS

s Overexpression of LIF can enhance cisplatin and paclitaxel resistance to endometrial cancer cells in vitro.

Self-Renewal Signalling Pathway Inhibitors: Perspectives on Therapeutic Approaches for Cancer Stem Cells

The poor survival and prognosis of individuals with cancer are often attributed to tumour relapse and metastasis, which may be due to the presence of cancer stem cells (CSCs). CSCs have the characteristics of self-renewal, differentiation potential, high carcinogenicity, and drug resistance. In addition, CSCs exhibit many characteristics similar to those of embryonic or tissue stem cells while displaying persistent abnormal activation of self-renewal pathways associated with development and tissue homeostasis, including the Wnt, Notch, Hedgehog (Hh), TGF-β, JAK/STAT3, and NF-κB pathways. Therefore, we can eliminate CSCs by targeting these self-renewal pathways to constrain stem cell replication, survival and differentiation. At the same time, we cannot neglect the ping-pong effect of the tumour microenvironment, which releases cytokines and promotes self-renewal pathways in CSCs. Recently, meaningful progress has been made in the study of inhibitors of self-renewal pathways in tumours. This review primarily summarizes several representative and novel agents targeting these self-renewal signalling pathways and the tumour microenvironment and that represent a promising strategy for treating refractory and recurrent cancer.

Targeting Jak/Stat pathway as a therapeutic strategy against SP/CD44+ tumorigenic cells in Akt/β-catenin-driven hepatocellular carcinoma

BACKGROUND & AIMS

Hepatic resection and liver transplantation with adjuvant chemo- and radiotherapy are the mainstay of hepatocellular carcinoma (HCC) treatment, but the 5-year survival rate remains poor because of frequent recurrence and intrahepatic metastasis. Only sorafenib and lenvatinib are currently approved for the first-line treatment of advanced, unresected HCC, but they yield modest survival benefits. Thus, there is a need to identify new therapeutic targets to improve current HCC treatment modalities.

METHODS

The HCC tumor model was generated by hydrodynamic transfection of AKT1 and β-catenin (CTNNB1) oncogenes. Cancer cells with stemness properties were characterized following isolation using side population (SP) and CD44 surface markers by flow cytometry. The effect of Jak/Stat inhibitors was analyzed in vitro by using tumorsphere culture and in vivo using an allograft mouse model.

RESULTS

Co-activation of both Wnt/β-catenin and Akt/mTOR pathways was found in 14.4% of our HCC patient cohort. More importantly, these patients showed poorer survival than those with either Wnt/β-catenin or Akt/mTOR pathway activation alone, demonstrating the clinical relevance of our study. In addition, we observed that Akt/β-catenin tumors contained a subpopulation of cells with stem/progenitor-like characteristics identified through SP analysis and expression of the cancer stem cell-like marker CD44, which may contribute to tumor self-renewal and drug resistance. Consequently, we identified small molecule inhibitors of the Jak/Stat pathway that demonstrated efficacy in mitigating tumor proliferation and formation in Akt/β-catenin-driven HCC.

CONCLUSIONS

In conclusion, we have shown that Akt/β-catenin tumors contain a subpopulation of tumor-initiating cells with stem/progenitor-like characteristics which can be effectively targeted with inhibitors of the Jak/Stat pathway, demonstrating that inhibition of the Jak/Stat pathway could be an alternative method to overcome drug resistance and effectively treat Akt/β-catenin-driven HCC tumors.

LAY SUMMARY

The prognosis for patients with hepatocellular carcinoma is poor, partly because of the lack of effective treatment options for those with more advanced disease. In this study, we identified a subpopulation of cancer cells with stem cell-like properties that were critical for tumor maintenance and growth in a mouse model of hepatocellular carcinoma. Through further experiments, we demonstrated that the Jak/Stat pathway is a promising therapeutic target in hepatocellular carcinoma.

MicroRNA-Based Combinatorial Cancer Therapy: Effects of MicroRNAs on the Efficacy of Anti-Cancer Therapies

The susceptibility of cancer cells to different types of treatments can be restricted by intrinsic and acquired therapeutic resistance, leading to the failure of cancer regression and remission. To overcome this problem, a combination therapy has been proposed as a fundamental strategy to improve therapeutic responses; however, resistance is still unavoidable. MicroRNA (miRNAs) are associated with cancer therapeutic resistance. The modulation of dysregulated miRNA levels through miRNA-based therapy comprising a replacement or inhibition approach has been proposed to sensitize cancer cells to other anti-cancer therapies. The combination of miRNA-based therapy with other anti-cancer therapies (miRNA-based combinatorial cancer therapy) is attractive, due to the ability of miRNAs to target multiple genes associated with the signaling pathways controlling therapeutic resistance. In this article, we present an overview of recent findings on the role of therapeutic resistance-related miRNAs in different types of cancer. We review the feasibility of utilizing dysregulated miRNAs in cancer cells and extracellular vesicles as potential candidates for miRNA-based combinatorial cancer therapy. We also discuss innate properties of miRNAs that need to be considered for more effective combinatorial cancer therapy.

HBX-induced miR-5188 impairs FOXO1 to stimulate β-catenin nuclear translocation and promotes tumor stemness in hepatocellular carcinoma

Cancer stem cells (CSCs) are the key factor in determining cancer recurrence, metastasis, chemoresistance and patient prognosis in hepatocellular carcinoma (HCC). The role of miR-5188 in cancer stemness has never been documented. In this study, we investigated the clinical and biological roles of miR-5188 in HCC. Methods: MiRNA expression in HCC was analyzed by bioinformatics analysis and in situ hybridization. The biological effect of miR-5188 was demonstrated in both in vitro and in vivo studies through the ectopic expression of miR-5188. The target gene and molecular pathway of miR-5188 were characterized using bioinformatics tools, dual-luciferase reporter assays, gene knockdown, and rescue experiments. Results: MiR-5188 was shown to be upregulated and confer poor prognosis in HCC patient data from TCGA database. MiR-5188 was subsequently identified as a significant inducer of cancer stemness that promotes HCC pathogenesis. Specifically, the targeting of miR-5188 by its antagomir markedly prolonged the survival time of HCC-bearing mice and improved HCC cell chemosensitivity in vivo. Mechanistic analysis indicated that miR-5188 directly targets FOXO1, which interacts with β-catenin in the cytoplasm to reduce the nuclear translocation of β-catenin and promotes the activation of Wnt signaling and downstream tumor stemness, EMT, and c-Jun. Moreover, c-Jun transcriptionally activates miR-5188 expression, forming a positive feedback loop. Interestingly, the miR-5188-FOXO1/β-catenin-c-Jun feedback loop was induced by hepatitis X protein (HBX) through Wnt signaling and participated in the HBX-induced pathogenesis of HCC. Finally, analyses of transcriptomics data and our clinical data supported the significance of the abnormal expression of the miR-5188 pathway in HCC pathogenesis. Conclusions: These findings present the inhibition of miR-5188 as a novel strategy for the efficient elimination of CSCs to prevent tumor metastasis, recurrence and chemoresistance in patients with hepatocellular carcinoma. Our study highlights the importance of miR-5188 as a tumor stemness inducer that acts as a potential target for HCC treatment.

Nanoparticles Targeting STATs in Cancer Therapy

Over the past decades, an increase in the incidence rate of cancer has been witnessed. Although many efforts have been made to manage and treat this life threatening condition, it is still one of the leading causes of death worldwide. Therefore, scientists have attempted to target molecular signaling pathways involved in cancer initiation and metastasis. It has been shown that signal transducers and activator of transcription (STAT) contributes to the progression of cancer cells. This important signaling pathway is associated with a number of biological processes including cell cycle, differentiation, proliferation and apoptosis. It appears that dysregulation of the STAT signaling pathway promotes the migration, viability and malignancy of various tumor cells. Hence, there have been many attempts to target the STAT signaling pathway. However, it seems that currently applied therapeutics may not be able to effectively modulate the STAT signaling pathway and suffer from a variety of drawbacks such as low bioavailability and lack of specific tumor targeting. In the present review, we demonstrate how nanocarriers can be successfully applied for encapsulation of STAT modulators in cancer therapy.

Danazol mediates collateral sensitivity via STAT3/Myc related pathway in multidrug-resistant cancer cells

Multidrug resistance presents an obstacle in cancer treatment. Among numerous combative strategies, collateral sensitivity (CS) drugs have opened a new avenue to defeat cancer by exploiting selective toxicity against multidrug-resistant (MDR) cancer. In the present study, a clinically used synthetic steroid hormone, danazol, was investigated for its CS properties and cytotoxic mechanisms. Compared with natural hormones, danazol possessed a stronger selective cytotoxicity against MDR cancer cells. Danazol induced the arrest of MDR cancer cells at the G2/M phase and caspase-8–related early apoptosis. Furthermore, in MDR cancer cells, danazol reduced STAT3 phosphorylation as well as the expression of STAT3-regulated genes involved in cell survival, such as c-Myc, CDC25, and CDK1. Danazol also upregulated the cell cycle inhibitor p21 in MDR cancer cells. Supporting the experimental results, docking studies have revealed that danazol can likely bind favourably with STAT3. Taken together, our results suggest that danazol exerts a CS effect by inhibiting the STAT3 pathway in MDR cancer cells and thus provides a possible solution for MDR cancers.

Piperlongumine Induces Apoptosis and Synergizes with Doxorubicin by Inhibiting the JAK2-STAT3 Pathway in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) lacks major effective target molecules and chemotherapy remains the current main treatment. However, traditional chemotherapy drugs, such as doxorubicin (DOX), cause serious side effects and have a poor prognosis. Piperlongumine (PL), a natural alkaloid, has showed selective anticancer effects and is expected to become a new strategy against TNBC. In our research, cell viability, colony formation, flow cytometry, Western blot, and tumor xenograft model assays were established to evaluate the suppression effect of PL and DOX alone and in combination. Data showed that PL could effectively inhibit cell growth and induce apoptosis in two TNBC cell lines. We also demonstrated for the first time that the combination treatment of PL and DOX synergistically inhibited cell growth and induced apoptosis in TNBC cells. The suppression of STAT3 activation was indicated to be a mechanism of the anticancer effect. Moreover, the effectiveness of this combination was confirmed in a tumor xenograft model. These results revealed that inhibition of the JAK2-STAT3 pathway was a key anticancer mechanism when treated with PL alone or combined with DOX, suggesting that the combination of PL and chemotherapy drugs may be a potential strategy for the clinical treatment of TNBC.