Induced pluripotent stem cells: A new strategy to model human cancer

Stem Cell Therapy for the Treatment of Parkinson's Disease: What Promise Does it Hold?

Parkinson's disease (PD) is a common, progressive neurodegenerative disorder characterized by substantia nigra dopamine cell death and a varied clinical picture that affects older people. Although more than two centuries have passed since the earliest attempts to find a cure for PD, it remains an unresolved problem. With this in mind, cell replacement therapy is a new strategy for treating PD. This novel approach aims to replace degenerated dopaminergic (DAergic) neurons with new ones or provide a new source of cells that can differentiate into DAergic neurons. Induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs), neural stem cells (NSCs), and embryonic stem cells (ESCs) are among the cells considered for transplantation therapies. Recently disease-modifying strategies like cell replacement therapies combined with other therapeutic approaches, such as utilizing natural compounds or biomaterials, are proposed to modify the underlying neurodegeneration. In the present review, we discuss the current advances in cell replacement therapy for PD and summarize the existing experimental and clinical evidence supporting this approach.

Application of Induced Pluripotent Stem Cells in Malignant Solid Tumors

In the past decade, induced pluripotent stem cells (iPSCs) technology has significantly progressed in studying malignant solid tumors. This technically feasible reprogramming techniques can reawaken sequestered dormant regions that regulate the fate of differentiated cells. Despite the evolving therapeutic modalities for malignant solid tumors, treatment outcomes have not been satisfactory. Recently, scientists attempted to apply induced pluripotent stem cell technology to cancer research, from modeling to treatment. Induced pluripotent stem cells derived from somatic cells, cancer cell lines, primary tumors, and individuals with an inherited propensity to develop cancer have shown great potential in cancer modeling, cell therapy, immunotherapy, and understanding tumor progression. This review summarizes the evolution of induced pluripotent stem cells technology and its applications in malignant solid tumor. Additionally, we discuss potential obstacles to induced pluripotent stem cell technology.

Application of 3D- printed hydrogels in wound healing and regenerative medicine

Hydrogels are three-dimensional polymer networks with hydrophilic properties. The modifiable properties of hydrogels and the structure resembling living tissue allow their versatile application. Therefore, increasing attention is focused on the use of hydrogels as bioinks for three-dimensional (3D) printing in tissue engineering. Bioprinting involves the fabrication of complex structures from several types of materials, cells, and bioactive compounds. Stem cells (SC), such as mesenchymal stromal cells (MSCs) are frequently employed in 3D constructs. SCs have desirable biological properties such as the ability to differentiate into various types of tissue and high proliferative capacity. Encapsulating SCs in 3D hydrogel constructs enhances their reparative abilities and improves the likelihood of reaching target tissues. In addition, created constructs can simulate the tissue environment and mimic biological signals. Importantly, the immunogenicity of scaffolds is minimized through the use of patient-specific cells and the biocompatibility and biodegradability of the employed biopolymers. Regenerative medicine is taking advantage of the aforementioned capabilities in regenerating various tissues- muscle, bones, nerves, heart, skin, and cartilage.

Ferroptosis in cancer stem cells

Ferroptosis is an iron-dependent form of RCD correlates with the accumulation of markers of lipid peroxidation. Bulks of studies focusing on revealing ferroptosis and its regulators involved in oncogenic pathways. Connection between iron metabolism and abnormal iron metabolism in CSCs synergistically making ferroptosis a target process of great potential in combating with CSCs to improve therapeutic effectiveness and reverse resistance. Ferroptosis inducers could specifically induce CSCs death in tumors, predisposing ferroptosis to a target in killing CSCs to overcome cancer resistances. By ferroptosis induction and other cell death pathways in CSCs, cancer therapeutic outcome would be improved.

Circular RNAs in stem cells: from basic research to clinical implications

Circular RNAs (circRNAs) are a special class of endogenous RNAs with a wide variety of pathophysiological functions via diverse mechanisms, including transcription, microRNA (miRNA) sponge, protein sponge/decoy, and translation. Stem cells are pluripotent cells with unique properties of self-renewal and differentiation. Dysregulated circRNAs identified in various stem cell types can affect stem cell self-renewal and differentiation potential by manipulating stemness. However, the emerging roles of circRNAs in stem cells remain largely unknown. This review summarizes the major functions and mechanisms of action of circRNAs in stem cell biology and disease progression. We also highlight circRNA-mediated common pathways in diverse stem cell types and discuss their diagnostic significance with respect to stem cell-based therapy.

The Role of RNA Methylation in Regulating Stem Cell Fate and Function-Focus on m6A

The biological role of RNA methylation in stem cells has attracted increasing attention. Recent studies have demonstrated that RNA methylation plays a crucial role in self-renewal, differentiation, and tumorigenicity of stem cells. In this review, we focus on the biological role of RNA methylation modifications including N6-methyladenosine, 5-methylcytosine, and uridylation in embryonic stem cells, adult stem cells, induced pluripotent stem cells, and cancer stem cells, so as to provide new insights into the potential innovative treatments of cancer or other complex diseases.

Development and in vitro characterisation of an induced pluripotent stem cell model of ovarian cancer

Ovarian cancer recurs despite advances in treatment and is due to drug resistance. The persistence of cancer stem cells (CSCs) is one of the causes. It has been challenging to maintain CSCs long term in culture from primary malignant cells. Reprogramming cancer cells into induced pluripotent stem cells (iPSCs) could be an approach to achieve this. An ovarian cancer cell line, PEO4, was initially reprogrammed into iPSCs using the classical four factors OCT4, SOX2, KLF4 and MYC (OSKM) using lentivirus transduction. The PEO4-OSKM-cells had all the hallmarks of iPSCs. As MYC is oncogenic, we have replaced it with GLIS1 and show that PEO4 cells could be transformed into iPSCs. The transfection efficiency was two-fold better with OCT4-SOX2-KLF4-GLIS1 (OSKG) with larger colonies. Further, normal fallopian tube epithelial cells were also transformed using OSKG into iPSCs. iPSCs expressed CSCs markers such as CD133, EPHA1, ALDH1A1 and LGR5 prominently and were more resistant to cisplatin and taxol as compared to parental PEO4 cells. PEO4-OSKM-iPSCs cells formed more colonies in a clonogenic assay as compared to PEO4-OSKG-iPSCs and parental cells. These results provide a first insight that both an ovarian cancer cell line and fallopian tube epithelial cells can be reprogrammed and GLIS1 can successfully replace MYC as a transcription factor. This in vitro model is useful for future experiments to understand the characteristics of CSCs in the pathogenesis of ovarian cancer.

Pluripotent Stem Cells: Cancer Study, Therapy, and Vaccination

INTRODUCTION

Pluripotent stem cells (PSCs) are promising tools for modern regenerative medicine applications because of their stemness properties, which include unlimited self-renewal and the ability to differentiate into all cell types in the body. Evidence suggests that a rare population of cells within a tumor, termed cancer stem cells (CSCs), exhibit stemness and phenotypic plasticity properties that are primarily responsible for resistance to chemotherapy, radiotherapy, metastasis, cancer development, and tumor relapse. Different therapeutic approaches that target CSCs have been developed for tumor eradication.

RESULTS AND DISCUSSION

In this review, we first provide an overview of different viewpoints about the origin of CSCs. Particular attention has been paid to views believe that CSCs are probably appeared through dysregulation of very small embryonic-like stem cells (VSELs) which reside in various tissues as the main candidate for tissue-specific stem cells. The expression of pluripotency markers in these two types of cells can strengthen the validity of this theory. In this regard, we discuss the common properties of CSCs and PSCs, and highlight the potential of PSCs in cancer studies, therapeutic applications, as well as educating the immune system against CSCs.

CONCLUSION

In conclusion, the resemblance of CSCs to PSCs can provide an appropriate source of CSC-specific antigens through cultivation of PSCs which brings to light promising ideas for prophylactic and therapeutic cancer vaccine development.

Autophagy-related long non-coding RNA signature for ovarian cancer

OBJECTIVE

Ovarian cancer (OC) affects nearly 22,000 women annually in the United States and ranks fifth in cancer deaths, largely because of being diagnosed at an advanced stage. Autophagy is the cellular process of self-degrading damaged or degenerate proteins and organelles. Long non-coding RNAs (lncRNAs) are a group of RNA molecules whose transcripts are greater than 200 nt but are not translated into proteins. However, just a small number of autophagy-related lncRNAs have been explored in depth.

METHODS

We used RNA sequencing data from The Cancer Genome Atlas (TCGA) and autophagy datasets to identify dysfunctional autophagy-related lncRNAs and provide potential useful biomarkers for OC diagnosis and prognosis.

RESULTS

Seventeen differentially expressed lncRNAs (AC010186.3, AC006001.2, LBX2-AS1, SNHG17, AC011445.1, AC083880.1, MIR193BHG, AC025259.3, HCG14, AC007114.1, AC108673.2, USP30-AS1, AC010336.5, LINC01132, AC006333.2, LINC00665 and AC027348.1) were selected as independent prognostic factors for OC patients. Functional annotation of the data was performed through gene set enrichment analysis (GSEA). The results suggested that the high-risk group was mainly enriched in specific tumor-related and metabolism pathways.

CONCLUSION

Based on the online databases, we identified novel autophagy-related lncRNAs for the prognosis of ovarian cancer.

Engineering anti-cancer nanovaccine based on antigen cross-presentation

Dendritic cells (DCs) present exogenous antigens on major histocompatibility complex (MHC) class I molecules, thereby activating CD8⁺ T cells, contributing to tumor elimination through a mechanism known as antigen cross-presentation. A variety of factors such as maturation state of DCs, co-stimulatory signals, T-cell microenvironment, antigen internalization routes and adjuvants regulate the process of DC-mediated antigen cross-presentation. Recently, the development of successful cancer immunotherapies may be attributed to the ability of DCs to cross-present tumor antigens. In this review article, we focus on the underlying mechanism of antigen cross-presentation and ways to improve antigen cross-presentation in different DC subsets. We have critically summarized the recent developments in the generation of novel nanovaccines for robust CD8⁺ T-cell response in cancer. In this context, we have reviewed nanocarriers that have been used for cancer immunotherapeutics based on antigen cross-presentation mechanism. Additionally, we have also expressed our views on the future applications of this mechanism in curing cancer.

Ferroptosis: An emerging approach for targeting cancer stem cells and drug resistance

Resistance to chemotherapeutic agents remains a major challenge in the fierce battle against cancer. Cancer stem cells (CSCs) are a small population of cells in tumors that possesses the ability to self-renew, initiate tumors, and cause resistance to conventional anticancer agents. Targeting this population of cells was proven as a promising approach to eliminate cancer recurrence and improve the clinical outcome. CSCs are less susceptible to death by classical anticancer agents inducing apoptosis. CSCs can be eradicated by ferroptosis, which is a non-apoptotic-regulated mechanism of cell death. The induction of ferroptosis is an attractive strategy to eliminate tumors due to its ability to selectively target aggressive CSCs. The current review critically explored the crosstalk and regulatory pathways controlling ferroptosis, which can selectively induce CSCs death. In addition, successful chemotherapeutic agents that achieve better therapeutic outcomes through the induction of ferroptosis in CSCs were discussed to highlight their promising clinical impact.

Reprogramming Prostate Cancer Cells into Induced Pluripotent Stem Cells: a Promising Model of Prostate Cancer Stem Cell Research

Prostate cancer stem cells (PrCSCs) are responsible for the development of castration-resistant disease and are associated with poor outcomes; however, the origin of PrCSCs is still not known due to the lack of a suitable model. In the current study, the human prostate cancer cell line 22RV1 was used to generate induced pluripotent stem cells (iPSCs) via the exogenous expression of four classic transcription factors (OCT-4, SOX2, KLF4, and C-MYC). The iPSCs were analyzed by phase contrast microscopy, real-time polymerase chain reaction, immunofluorescence, alkaline phosphatase (AP) activity, and examined for karyotype and embryoid body and teratoma formation. The analyses demonstrated that the prostate cancer cells were successfully reprogrammed into iPSCs by characteristic human embryonic stem cell morphology, cell marker expression, AP activity, embryoid body, and pluripotency capability in generating all three embryonic germ layers. These results may provide a convenient and accessible model for studying the origin of PrCSCs and the process by which progenitor cells are transformed into PrCSCs.

A brief overview of antitumoral actions of bruceine D

Cancer remains the second leading cause of mortality globally. In combating cancer, conventional chemotherapy and/or radiotherapy are administered as first-line therapy. However, these are usually accompanied with adverse side effects that decrease the quality of patient’s lives. As such, natural bioactive compounds have gained an attraction in the scientific and medical community as evidence of their anticancer properties and attenuation of side effects mounted. In particular, quassinoids have been found to exhibit a plethora of inhibitory activities such as anti-proliferative effects on tumor development and metastasis. Recently, bruceine D, a quassinoid isolated from the shrub Brucea javanica (L.) Merr. (Simaroubaceae), has come under immense investigation on its antineoplastic properties in various human cancers including pancreas, breast, lung, blood, bone, and liver. In this review, we have highlighted the antineoplastic effects of bruceine D and its mode of actions in different tumor models.

Human hair follicle-derived mesenchymal stem cells: Isolation, expansion, and differentiation

Hair follicles are easily accessible skin appendages that protect against cold and potential injuries. Hair follicles contain various pools of stem cells, such as epithelial, melanocyte, and mesenchymal stem cells (MSCs) that continuously self-renew, differentiate, regulate hair growth, and maintain skin homeostasis. Recently, MSCs derived from the dermal papilla or dermal sheath of the human hair follicle have received attention because of their accessibility and broad differentiation potential. In this review, we describe the applications of human hair follicle-derived MSCs (hHF-MSCs) in tissue engineering and regenerative medicine. We have described protocols for isolating hHF-MSCs from human hair follicles and their culture condition in detail. We also summarize strategies for maintaining hHF-MSCs in a highly proliferative but undifferentiated state after repeated in vitro passages, including supplementation of growth factors, 3D suspension culture technology, and 3D aggregates of MSCs. In addition, we report the potential of hHF-MSCs in obtaining induced smooth muscle cells and tissue-engineered blood vessels, regenerated hair follicles, induced red blood cells, and induced pluripotent stem cells. In summary, the abundance, convenient accessibility, and broad differentiation potential make hHF-MSCs an ideal seed cell source of regenerative medical and cell therapy.

Deciphering the Mounting Complexity of the p53 Regulatory Network in Correlation to Long Non-Coding RNAs (lncRNAs) in Ovarian Cancer

Amongst the various gynecological malignancies affecting female health globally, ovarian cancer is one of the predominant and lethal among all. The identification and functional characterization of long non-coding RNAs (lncRNAs) are made possible with the advent of RNA-seq and the advancement of computational logarithm in understanding human disease biology. LncRNAs can interact with deoxyribonucleic acid (DNA), ribonucleic acid (RNA), proteins and their combinations. Moreover, lncRNAs regulate orchestra of diverse functions including chromatin organization and transcriptional and post-transcriptional regulation. LncRNAs have conferred their critical role in key biological processes in human cancer including tumor initiation, proliferation, cell cycle, apoptosis, necroptosis, autophagy, and metastasis. The interwoven function of tumor-suppressor protein p53-linked lncRNAs in the ovarian cancer paradigm is of paramount importance. Several lncRNAs operate as p53 regulators or effectors and modulates a diverse array of functions either by participating in various signaling cascades or via interaction with different proteins. This review highlights the recent progress made in the identification of p53 associated lncRNAs while elucidating their molecular mechanisms behind the altered expression in ovarian cancer tumorigenesis. Moreover, the development of novel clinical and therapeutic strategies for targeting lncRNAs in human cancers harbors great promise.

Plant lectins and their usage in preparing targeted nanovaccines for cancer immunotherapy

Plant lectins, a natural source of glycans with a therapeutic potential may lead to the discovery of new targeted therapies. Glycans extracted from plant lectins are known to act as ligands for C-type lectin receptors (CLRs) that are primarily present on immune cells. Plant-derived glycosylated lectins offer diversity in their N-linked oligosaccharide structures that can serve as a unique source of homogenous and heterogenous glycans. Among the plant lectins-derived glycan motifs, Man₉GlcNAc₂Asn exhibits high-affinity interactions with CLRs that may resemble glycan motifs of pathogens. Thus, such glycan domains when presented along with antigens complexed with a nanocarrier of choice may bewilder the immune cells and direct antigen cross-presentation - a cytotoxic T lymphocyte immune response mediated by CD8⁺ T cells. Glycan structure analysis has attracted considerable interest as glycans are looked upon as better therapeutic alternatives than monoclonal antibodies due to their cost-effectiveness, reduced toxicity and side effects, and high specificity. Furthermore, this approach will be useful to understand whether the multivalent glycan presentation on the surface of nanocarriers can overcome the low-affinity lectin-ligand interaction and thereby modulation of CLR-dependent immune response. Besides this, understanding how the heterogeneity of glycan structure impacts the antigen cross-presentation is pivotal to develop alternative targeted therapies. In the present review, we discuss the findings on structural analysis of glycans from natural lectins performed using GlycanBuilder2 - a software tool based on a thorough literature review of natural lectins. Additionally, we discuss how multiple parameters like the orientation of glycan ligands, ligand density, simultaneous targeting of multiple CLRs and design of antigen delivery nanocarriers may influence the CLR targeting efficacy. Integrating this information will eventually set the ground for new generation immunotherapeutic vaccine design for the treatment of various human malignancies.