Differential MicroRNA Expression Profile of Human Embryonic Stem Cell-Derived Cardiac Lineage Cells

Advancements in Human Embryonic Stem Cell Research: Clinical Applications and Ethical Issues

BACKGROUND

The development and use of human embryonic stem cells (hESCs) in regenerative medicine have been revolutionary, offering significant advancements in treating various diseases. These pluripotent cells, derived from early human embryos, are central to modern biomedical research. However, their application is mired in ethical and regulatory complexities related to the use of human embryos.

METHOD

This review utilized key databases such as ClinicalTrials.gov, EU Clinical Trials Register, PubMed, and Google Scholar to gather recent clinical trials and studies involving hESCs. The focus was on their clinical application in regenerative medicine, emphasizing clinical trials and research directly involving hESCs.

RESULTS

Preclinical studies and clinical trials in various areas like ophthalmology, neurology, endocrinology, and reproductive medicine have demonstrated the versatility of hESCs in regenerative medicine. These studies underscore the potential of hESCs in treating a wide array of conditions. However, the field faces ethical and regulatory challenges, with significant variations in policies and perspectives across different countries.

CONCLUSION

The potential of hESCs in regenerative medicine is immense, offering new avenues for treating previously incurable diseases. However, navigating the ethical, legal, and regulatory landscapes is crucial for the continued advancement and responsible application of hESC research in the medical field. Considering both scientific potential and ethical implications, a balanced approach is essential for successfully integrating hESCs into clinical practice.

miRNAs in Heart Development and Disease

Cardiovascular diseases (CVD) are a group of disorders that affect the heart and blood vessels. They include conditions such as myocardial infarction, coronary artery disease, heart failure, arrhythmia, and congenital heart defects. CVDs are the leading cause of death worldwide. Therefore, new medical interventions that aim to prevent, treat, or manage CVDs are of prime importance. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the posttranscriptional level and play important roles in various biological processes, including cardiac development, function, and disease. Moreover, miRNAs can also act as biomarkers and therapeutic targets. In order to identify and characterize miRNAs and their target genes, scientists take advantage of computational tools such as bioinformatic algorithms, which can also assist in analyzing miRNA expression profiles, functions, and interactions in different cardiac conditions. Indeed, the combination of miRNA research and bioinformatic algorithms has opened new avenues for understanding and treating CVDs. In this review, we summarize the current knowledge on the roles of miRNAs in cardiac development and CVDs, discuss the challenges and opportunities, and provide some examples of recent bioinformatics for miRNA research in cardiovascular biology and medicine.

Extracellular vesicles and microRNAs in the regulation of cardiomyocyte differentiation and proliferation

Cardiomyocyte differentiation and proliferation are essential processes for the regeneration of an injured heart. In recent years, there have been several reports highlighting the involvement of extracellular vesicles (EVs) in cardiomyocyte differentiation and proliferation. These EVs originate from mesenchymal stem cells, pluripotent stem cells, and heart constituting cells (cardiomyocytes, cardiac fibroblasts, cardiac progenitor cells, epicardium). Numerous reports also indicate the involvement of microRNAs (miRNAs) in cardiomyocyte differentiation and proliferation. Among them, miRNA-1, miRNA-133, and miRNA-499, recently demonstrated to promote cardiomyocyte differentiation, and miRNA-199, shown to promote cardiomyocyte proliferation, were found effective in various studies. MiRNA-132 and miRNA-133 have been identified as cargo in EVs and are reported to induce cardiomyocyte differentiation. Similarly, miRNA-30a, miRNA-100, miRNA-27a, miRNA-30e, miRNA-294 and miRNA-590 have also been identified as cargo in EVs and are shown to have a role in the promotion of cardiomyocyte proliferation. Regeneration of the heart by EVs or artificial nanoparticles containing functional miRNAs is expected in the future. In this review, we outline recent advancements in understanding the roles of EVs and miRNAs in cardiomyocyte differentiation and proliferation. Additionally, we explore the related challenges when utilizing EVs and miRNAs as a less risky approach to cardiac regeneration compared to cell transplantation.

Beyond AOPs: A Mechanistic Evaluation of NAMs in DART Testing

New Approach Methodologies (NAMs) promise to offer a unique opportunity to enable human-relevant safety decisions to be made without the need for animal testing in the context of exposure-driven Next Generation Risk Assessment (NGRA). Protecting human health against the potential effects a chemical may have on embryo-foetal development and/or aspects of reproductive biology using NGRA is particularly challenging. These are not single endpoint or health effects and risk assessments have traditionally relied on data from Developmental and Reproductive Toxicity (DART) tests in animals. There are numerous Adverse Outcome Pathways (AOPs) that can lead to DART, which means defining and developing strict testing strategies for every AOP, to predict apical outcomes, is neither a tenable goal nor a necessity to ensure NAM-based safety assessments are fit-for-purpose. Instead, a pragmatic approach is needed that uses the available knowledge and data to ensure NAM-based exposure-led safety assessments are sufficiently protective. To this end, the mechanistic and biological coverage of existing NAMs for DART were assessed and gaps to be addressed were identified, allowing the development of an approach that relies on generating data relevant to the overall mechanisms involved in human reproduction and embryo-foetal development. Using the knowledge of cellular processes and signalling pathways underlying the key stages in reproduction and development, we have developed a broad outline of endpoints informative of DART. When the existing NAMs were compared against this outline to determine whether they provide comprehensive coverage when integrated in a framework, we found them to generally cover the reproductive and developmental processes underlying the traditionally evaluated apical endpoint studies. The application of this safety assessment framework is illustrated using an exposure-led case study.

Hsa-miRNA-143-3p regulates the odontogenic differentiation of human stem cells from the apical papilla by targeting NFIC

AIM

To evaluate the effects of hsa-miRNA-143-3p on the cytodifferentiation of human stem cells from the apical papilla (hSCAPs) and the post-transcriptional regulation of Nuclear factor I-C (NFIC).

METHODOLOGY

miRNA expression profiles in human immature permanent teeth and during hSCAP differentiation were examined. hSCAPs were treated with miR-143-3p overexpression or silencing viruses, and the proliferation and odontogenic and osteogenic differentiation of these stem cells, and the involvement of the NFIC pathway, were investigated. Luciferase reporter and NFIC mutant plasmids were used to confirm NFIC mRNA as a direct target of miR-143-3p. NFIC expression analysis in the miR-143-3p overexpressing hSCAPs was used to investigate whether miR-143-3p functioned by targeting NFIC. Student's t-test and chi-square tests were used for statistical analysis.

RESULTS

miR-143-3p expression was screened by microarray profiling and was found to be significantly reduced during hSCAP differentiation (p < .05). Overexpression of miR-143-3p inhibited the mineralization of hSCAPs significantly (p < .05) and downregulated the levels of odontogenic differentiation markers (NFIC [p < .05], DSP [p < .01] and KLF4 [p < .01]), whereas silencing of miR-143-3p had the opposite effect. The luciferase reporter gene detection and bioinformatic approaches identified NFIC mRNA as a potential target of miR-143-3p. NFIC overexpression reversed the inhibitory effect of miR-143-3p on the odontogenic differentiation of hSCAPs.

CONCLUSIONS

miR-143-3p maintained the stemness of hSCAPs and modulated their differentiation negatively by directly targeting NFIC. Thus, inhibition of this miRNA represents a potential strategy to promote the regeneration of damaged tooth roots.

Transcriptome Analyses Identify Potential Key microRNAs and Their Target Genes Contributing to Ovarian Reserve

Female endocrinological symptoms, such as premature ovarian inefficiency (POI) are caused by diminished ovarian reserve and chemotherapy. The etiology of POI remains unknown, but this can lead to infertility. This has accelerated the search for master regulator genes or other molecules that contribute as enhancers or silencers. The impact of regulatory microRNAs (miRNAs) on POI has gained attention; however, their regulatory function in this condition is not well known. RNA sequencing was performed at four stages, 2-(2 W), 6-(6 W), 15-(15 W), and 20-(20 W) weeks, on ovarian tissue samples and 5058 differentially expressed genes (DEGs) were identified. Gene expression and enrichment were analyzed based on the gene ontology and KEGG databases, and their association with other proteins was assessed using the STRING database. Gene set enrichment analysis was performed to identify the key target genes. The DEGs were most highly enriched in 6 W and 15 W groups. Figla, GDF9, Nobox, and Pou51 were significantly in-creased at 2 W compared with levels at 6 W and 20 W, whereas the expression of Foxo1, Inha, and Taf4b was significantly de-creased at 20 W. Ccnd2 and Igf1 expression was maintained at similar levels in each stage. In total, 27 genes were upregulated and 26 genes interacted with miRNAs; moreover, stage-specific upregulated and downregulated interactions were demonstrated. Increased and decreased miRNAs were identified at each stage in the ovaries. The constitutively expressed genes, Ccnd2 and Igf1, were identified as the major targets of many miRNAs (p < 0.05), and Fshr and Foxo3 interacted with miRNAs, namely mmu-miR-670-3p and mmu-miR-153-3p. miR-26a-5p interacted with Piwil2, and its target genes were downregulated in the 20 W mouse ovary. In this study, we aimed to identify key miRNAs and their target genes encompassing the reproductive span of mouse ovaries using mRNA and miRNA sequencing. These results indicated that gene sets are regulated in the reproductive stage-specific manner via interaction with miRNAs. Furthermore, consistent expression of Ccnd2 and Igf1 is considered crucial for the ovarian reserve and is regulated by many interactive miRNAs.

MicroRNA Profiling of HL-1 Cardiac Cells-Derived Extracellular Vesicles

HL-1 is a cell line that shows a phenotype similar to adult cardiomyocytes. All major cardiac cell types release extracellular vesicles (EVs) that emerge as key mediators of intercellular communication. EVs can mediate intercellular cross-talk through the transfer of specific microRNAs (miRNAs). MiRNAs are known to play important regulatory roles during tissue differentiation and regeneration processes. Furthermore, miRNAs have recently been shown to be involved in the proliferation of adult cardiomyocytes. In this context, the purpose of this study was to analyze the transcriptomic profile of miRNAs expressed from HL-1 cardiac muscle cell-derived EVs, using next generation sequencing (NGS). Specifically, our transcriptomic analysis showed that the EVs derived from our HL-1 cells contained miRNAs that induce blood vessel formation and increase cell proliferation. Indeed, our bioinformatics analysis revealed 26 miRNAs expressed in EVs derived from our HL-1 that target genes related to cardiovascular development. In particular, their targets are enriched for the following biological processes related to cardiovascular development: heart morphogenesis, positive regulation of angiogenesis, artery development, ventricular septum development, cardiac atrium development, and myoblast differentiation. Consequently, EVs could become important in the field of regenerative medicine.

Circ_0068655 Promotes Cardiomyocyte Apoptosis via miR-498/PAWR Axis

BACKGROUND

The cardiomyocyte apoptosis is considered as one of major contributions to cardiac remodeling after myocardial infarction (MI). Numerous studies find that circular RNAs (circRNAs) play pivotal roles in a variety of biological functions. However, the role of circ_0068655 in MI and human induced pluripotent stem-derived cardiomyocytes (HCMs) remains unknown.

METHODS

The expression of circ_0068655, miR-498, and PRKC apoptosis WT1 regulator (PAWR) in human MI heart tissues and hypoxia subjected HCMs was evaluated with qRT-PCR and Western blot. The effects of circ_0068655 on hypoxia-induced apoptotic death and cell migration in HCMs were evaluated with qRT-PCR, cell viability, cell death ELISA (POD), and Caspase-3 activity assay, and Trans-well assay, respectively. Furthermore, luciferase assay, qRT-PCR, biotin-labeled miRNA pulldown assay, and Western blot were employed in the functional studies.

RESULTS

We found that the expression of circ_0068655 and PAWR was enhanced in MI patients and hypoxia subjected HCMs; by contrast, the expression of miR-498 decreased. Inhibited expression of circ_0068655 in HMCs counteracted hypoxia-induced apoptotic death and impaired cell migration, in sharp contrast to circ_0068655 knockdown. We identified that circ_0068655 sponged an endogenous miR-498 to sequester and inhibit its activity, leading to the increased PAWR expression.

CONCLUSIONS

Our findings reveal that the expression of circ_0068655 can promote cardiomyocyte apoptosis through the modulation of miR-498-PAWR axis in vitro, which highlights the diagnostic and therapeutic value of circ_0068655 in patients with MI.

Efficient differentiation of human ES and iPS cells into cardiomyocytes on biomaterials under xeno-free conditions

Current xeno-free and chemically defined methods for the differentiation of hPSCs (human pluripotent stem cells) into cardiomyocytes are not efficient and are sometimes not reproducible. Therefore, it is necessary to develop reliable and efficient methods for the differentiation of hPSCs into cardiomyocytes for future use in cardiovascular research related to drug discovery, cardiotoxicity screening, and disease modeling. We evaluated two representative differentiation methods that were reported previously, and we further developed original, more efficient methods for the differentiation of hPSCs into cardiomyocytes under xeno-free, chemically defined conditions. The developed protocol successively differentiated hPSCs into cardiomyocytes, approximately 90-97% of which expressed the cardiac marker cTnT, with beating speeds and sarcomere lengths that were similar to those of a healthy adult human heart. The optimal cell culture biomaterials for the cardiac differentiation of hPSCs were also evaluated using extracellular matrix-mimetic material-coated dishes. Synthemax II-coated and Laminin-521-coated dishes were found to be the most effective and efficient biomaterials for the cardiac differentiation of hPSCs according to the observation of hPSC-derived cardiomyocytes with high survival ratios, high beating colony numbers, a similar beating frequency to that of a healthy adult human heart, high purity levels (high cTnT expression) and longer sarcomere lengths similar to those of a healthy adult human heart.

A new possibility in fertility preservation: The artificial ovary

Conventional fertility preservation methods such as oocyte or embryo cryopreservation are currently insufficient to treat including those patients with prepubertal cancer and premature ovarian failure. Ovarian tissue cryopreservation presents as an alternative but has limitations with a potential risk of reintroducing malignant cells in patients who recover from cancer, those of chemotherapy prior to tissue cryopreservation. The so called "artificial ovary" aims to resolve this issue by transplanting isolated follicles with or without a biological scaffold. The artificial ovary may also offer an effective alternative option for those who cannot benefit from traditional assisted reproductive techniques such as in vitro fertilisation. To date, in animal studies and human trial, the artificial ovary restored endocrine function, achieved in vivo follicular development, and resulted in successful pregnancies. However, development of a technique for higher follicular recovery rate and a more optimised design of delivery scaffold, better transplantation techniques to prevent postsurgical ischemia, and consideration for genetic safety are required for safer and consistent human clinical applications. Ideas from different transplantation surgeries (e.g., entire ovary, ovarian cortex, and transplantation with tissue-engineered products) can be applied to enhance the efficacy of artificial ovarian transplantation. For the better application of artificial ovary, a deeper understanding of mechanical and biochemical properties of the ovary and folliculogenesis after cryopreservation, transplantation with or without scaffold, and development of sophisticated in vivo imaging techniques of transplanted artificial ovary need to precede its efficient clinical application.

Animal Models for Human Polycystic Ovary Syndrome (PCOS) Focused on the Use of Indirect Hormonal Perturbations: A Review of the Literature

Hormonal disturbances, such as hyperandrogenism, are considered important for developing polycystic ovary syndrome (PCOS) in humans. Accordingly, directly hormone-regulated animal models are widely used for studying PCOS, as they replicate several key PCOS features. However, the pathogenesis and treatment of PCOS are still unclear. In this review, we aimed to investigate animal PCOS models and PCOS-like phenotypes in animal experiments without direct hormonal interventions and determine the underlying mechanisms for a better understanding of PCOS. We summarized animal PCOS models that used indirect hormonal interventions and suggested or discussed pathogenesis of PCOS-like features in animals and PCOS-like phenotypes generated in other animals. We presented integrated physiological insights and shared cellular pathways underlying the pathogenesis of PCOS in reviewed animal models. Our review indicates that the hormonal and metabolic changes could be due to molecular dysregulations, such as upregulated PI3K-Akt and extracellular signal-regulated kinase (ERK) signalling, that potentially cause PCOS-like phenotypes in the animal models. This review will be helpful for considering alternative animal PCOS models to determine the cellular/molecular mechanisms underlying PCOS symptoms. The efforts to determine the specific cellular mechanisms of PCOS will contribute to novel treatments and control methods for this complex syndrome.

Modulatory Effects of Single and Complex Vitamins on the In Vitro Growth of Murine Ovarian Follicles

BACKGROUND

Vitamin is a well-known co-factor for many metabolic processes and its roles in fertility and follicular growth have been studied. Vitamin supplementation is frequently achieved by daily ingestion in the form of a complex capsule. However, the role of single and complex vitamins in in vitro maturation of murine follicles is not fully elucidated.

METHODS

In this study, we evaluated the effects of two forms of vitamins. Pure L-ascorbic acid, and multi-vitamin (vitamin C + vitamin B complex) was treated at two different concentrations (50 and 100 µg/ml), to pre-puberty murine follicles during in vitro maturation. To determine the specific stage of growth that is affected by treatment with vitamins, the vitamins were treated from day 0, 4, 9, and 13. Growth of each follicle was assessed by measuring diameters of whole expanded area and of the granulosa cells. Expression of follicular and oocyte growth-related genes and the effect of vitamin on the viability of follicles was assessed using senescence associated β-galactosidase staining.

RESULTS

Treatment with vitamins promoted the in vitro growth of murine follicles and the upregulated the expression of granulosa cell- and oocyte-specific genes such as BMP15, Fsh receptor, and GDF9. The proliferation of the granulosa cells was enhanced by the treatment of vitamin. Fifty µg/ml concentration vitamin showed greater effects compared to higher concentration. The viability of in vitro grown follicles was also significantly improved in vitamin-treated follicles. The effects of single L-ascorbic acid and complex vitamin were not significantly different to those of day 4 and day 9 follicles. Vitamins promoted murine follicle development in vitro with different effects on specific growth stage.

CONCLUSION

Supplementation of vitamins during in vitro maturation of murine follicles is an efficient strategy for in vitro expansion of follicular cells. These results could be customized to the sophisticated culture of follicles retrieved from aged or cancer-survived female that contain smaller number of follicles with reduced potential to develop into mature follicles.

Efficient Production of Murine Uterine Damage Model

BACKGROUND

Thin or damaged endometrium causes uterine factor-derived infertility resulting in a failure of embryonic implantation. Regeneration of endometrium is a major issue in gynecology and reproductive medicine. Various types of cells and scaffolds were studied to establish an effective therapeutic strategy. For this type of investigations, production of optimal animal models is indispensable. In this study, we tried to establish various murine uterine damage models and compared their features.

METHODS

Three to ten-week-old C57BL/6 female mice were anesthetized using isoflurane. Chemical and mechanical methods using ethanol (EtOH) at 70 or 100% and copper scraper were compared to determine the most efficient condition. Damage of uterine tissue was induced either by vaginal or dorsal surgical approach. After 7-10 days, gross and microscopic morphology, safety and efficiency were compared among the groups.

RESULTS

Both chemical and mechanical methods resulted in thinner endometrium and reduced number of glands. Gross morphology assessment revealed that the damaged regions of uteri showed various shapes including shrinkage or cystic dilatation of uterine horns. The duration of anesthesia significantly affected recovery after procedure. Uterine damage was most effectively induced by dorsal approach using 100% EtOH treatment compared to mechanical methods.

CONCLUSION

Taken together, murine uterine damage models were most successfully established by chemical treatment. This production protocols could be applied further to larger animals such as non-human primate.

Expression of Transcripts in Marmoset Oocytes Retrieved during Follicle Isolation Without Gonadotropin Induction

The in vitro maturation of oocytes is frequently used as an assisted reproductive technique (ART), and has been successfully established in humans and rodents. To overcome the limitations of ART, novel procedures for the in vitro maturation of early follicles are emerging. During the follicle isolation procedure, the unintended rupture of each follicle leads to a release of extra oocytes. Such oocytes, which are obtained during follicle isolation from marmosets, can be used for early maturation studies. Marmoset (Callithrix jacchus), which is classified as a new-world monkey, is a novel model that has been employed in reproductive biomedical research, as its reproductive physiology is similar to that of humans in several aspects. The ovaries of female marmosets were collected, and the excess oocytes present during follicle isolation were retrieved without pre-gonadotropin induction. Each oocyte was matured in vitro for 48 h in the presence of various concentrations of human chorionic gonadotropin (hCG) and epidermal growth factor (EGF), and the maturity of oocytes and optimal maturation conditions were evaluated. Each oocyte was individually reverse-transcribed, and the expression of mRNAs and microRNAs (miRs) were analyzed. Concentrations of hCG significantly affected the maturation rate of oocytes [the number of metaphase II (MII) oocytes]. The expression of BMP15 and ZP1 was highest when the oocytes were matured using 100 IU/L of hCG without pre-treatment with gonadotropins, and that of Cja-mir-27a was highest when cultured with follicle stimulating hormone. These results suggest that these up-regulated miRs affect the maturation of oocytes. Interactions with other protein networks were analyzed, and a strong association of BMP15 and ZP1 with sperm binding receptor (ACR), anti-Müllerian hormone (AMH), and AMH receptor was demonstrated, which is related to the proliferation of granulosa cells. Collectively, on the basis of these results, the authors propose optimal maturation conditions of excess oocytes of marmoset without in vivo gonadotropin treatment, and demonstrated the roles of miRs in early oocyte maturation at the single-cell level in marmosets.

Variation in MicroRNA Expression Profile of Uterine Leiomyoma with Endometrial Cavity Distortion and Endometrial Cavity Non-Distortion

The expression profile of microRNA (miRNA) in uterine leiomyoma (UL) cells is different from that in normal uterine myometrial (UM) cells. The effect of UL cells on uterine receptivity might vary according to their ability to distort the uterine endometrial cavity. However, the variation in miRNA expression profiles between endometrial cavity-distorting leiomyoma (ECDL) and endometrial cavity non-distorting leiomyoma (ECNDL) cells remains unknown. This study aimed to elucidate whether the expression profile of miRNAs in ECDL cells is dissimilar to that of ECNDL cells in uterus. Pelviscopic myomectomy was performed to obtain tissue samples of UL and their corresponding normal UM tissues (matched) from patients with UL (n = 26), among whom women with ECNDL and ECDL numbered 15 and 11, respectively. The relative expression of hsa-miR-15b, -29a, -29b, -29c, -197, and -200c as well as the candidate target genes in UL cells was compared to those in the matched UM cells using qRT-PCR to assess their ability to cause ECD. The spatial expression of miRNAs and target genes in the UL tissues was analyzed using in situ hybridization. Target gene expression was analyzed using qPCR after transfection with the mimics and inhibitors of miRNAs in UL cells. The relative expression level of miR-15b was upregulated, and the relative expression levels of miR-29a, -29b, -29c, -197, and -200c were downregulated in UL cells compared to those in UM cells. The relative expression levels of progesterone receptor, estrogen receptor, and matrix metalloproteinases (MMPs) were upregulated in UL cells compared to those in UM cells. The relative expression levels of miR-29c and -200c were downregulated, and the relative expression levels of estrogen receptor, MMPs and tissue inhibitors of metalloproteinases (TIMPs) were upregulated in ECDL cells compared to those in ECNDL cells. The expression profile of miRNAs in UL cells varied with respect to the occurrence or absence of endometrial cavity distortion. The biochemical properties of UL might be regulated by miRNAs in order to alter their effect on structural homeostasis of the uterus.

The Use of Normal Stem Cells and Cancer Stem Cells for Potential Anti-Cancer Therapeutic Strategy

BACKGROUND

Despite recent advance in conventional cancer therapies including surgery, radiotherapy, chemotherapy, and immunotherapy to reduce tumor size, unfortunately cancer mortality and metastatic cancer incidence remain high. Along with a deeper understanding of stem cell biology, cancer stem cell (CSC) is important in targeted cancer therapy. Herein, we review representative patents using not only normal stem cells as therapeutics themselves or delivery vehicles, but also CSCs as targets for anti-cancer strategy.

METHODS

Relevant patent literatures published between 2005 and 2017 are discussed to present developmental status and experimental results on using normal stem cells and CSCs for cancer therapy and explore potential future directions in this field.

RESULTS

Stem cells have been considered as important element of regenerative therapy by promoting tissue regeneration. Particularly, there is a growing trend to use stem cells as a target drug-delivery system to reduce undesirable side effects in non-target tissues. Noteworthy, studies on CSC-specific markers for distinguishing CSCs from normal stem cells and mature cancer cells have been conducted as a selective anti-cancer therapy with few side effects. Many researchers have also reported the development of various substances with anticancer effects by targeting CSCs from cancer tissues.

CONCLUSION

There has been a continuing increase in the number of studies on therapeutic stem cells and CSC-specific markers for selective diagnosis and therapy of cancer. This review focuses on the current status in the use of normal stem cells and CSCs for targeted cancer therapy. Future direction is also proposed.