EIF5A2 enhances stemness of epithelial ovarian cancer cells via a E2F1/KLF4 axis

Knocking down RAD51AP1 enhances chemosensitivity by inhibiting the self-renewal of CD133 positive ovarian cancer stem-like cells

PURPOSE

This study was designed to investigate the function of RAD51AP1 in the self-renewal and chemosensitivity of CD133 positive (CD133+) ovarian cancer (OC) stem-like cells.

METHODS

CD133+ (CD133 positive) OVCAR4 and CD133 negative (CD133-) OVCAR4 cells were separated from OVCAR4 by flow cytometry. Then, the separated CD133+OVCAR4 cells were divided into the following groups: Vector group; RAD51AP1 group; siNC group; si-RAD51AP1 group. Next, sphere-formation assay and colony forming assay were used to evaluate the self-renewal and proliferation ability of cells; western blot to detect the expression of RAD51AP1, transforming growth factor beta 1 (TGF-β1) and SMAD4 proteins in tissues and cells; qRT-PCR to assess the mRNA levels of sex-determining region Y-box 2 (SOX2), octamer-binding transcription factor 4 (OCT4), NANOG and Kruppel-like factor 4 (KLF4).

RESULTS

The performance of CD133+OVCAR4 cells was much better than that of CD133-OVCAR4 cells in sphere-formation assay and colony forming assay. Besides, compared with adjacent group and CD133-OVCAR4 cells, the expression level of RAD51AP1 increased significantly in OC group and CD133+OVCAR4 cells. Moreover, the over-expression of RAD51AP1 promoted the self-renewal and proliferation of CD133+OVCAR4 cells. On the contrary, knocking down the expression level of RAD51AP1 could inhibit the self-renewal and proliferation of CD133+OVCAR4 cells and improve the sensitivity of cells to chemotherapy drugs.

CONCLUSION

The findings of this study showed that RAD51AP1 was highly expressed in OC tissue and CD133+OVCAR4 cells, and regulated the self-renewal and chemosensitivity of tumor cells through the TGF-β1/SMAD4 signaling pathway.

Advances in ovarian tumor stem cells and therapy

Ovarian cancer is considered the most lethal among all gynecological malignancies due to its early metastatic dissemination, extensive spread, and malignant ascites. The current standard of care for advanced ovarian cancer involves a combination of cytoreductive surgery and chemotherapy utilizing platinum-based and taxane-based agents. Although initial treatment yields clinical remission in 70-80% of patients, the majority eventually develop treatment resistance and tumor recurrence. A growing body of evidence indicates the existence of cancer stem cells within diverse solid tumors, including ovarian cancer, which function as a subpopulation to propel tumor growth and disease advancement by means of drug resistance, recurrence, and metastasis. The presence of ovarian cancer stem cells is widely considered to be a significant contributor to the unfavorable clinical outcomes observed in patients with ovarian cancer, as they play a crucial role in mediating chemotherapy resistance, recurrence, and metastasis. Ovarian cancer stem cells possess the capacity to reassemble within the entirety of the tumor following conventional treatment, thereby instigating the recurrence of ovarian cancer and inducing resistance to treatment. Consequently, the creation of therapeutic approaches aimed at eliminating ovarian cancer stem cells holds great potential for the management of ovarian cancer. These cells are regarded as one of the most auspicious targets and mechanisms for the treatment of ovarian cancer. There is a pressing need for a comprehensive comprehension of the fundamental mechanisms of ovarian cancer's recurrence, metastasis, and drug resistance, alongside the development of effective strategies to overcome chemoresistance, metastasis, and recurrence. The implementation of cancer stem cell therapies may potentially augment the tumor cells' sensitivity to existing chemotherapy protocols, thereby mitigating the risks of tumor metastasis and recurrence, and ultimately improving the survival rates of ovarian cancer patients.

Research progress of epithelial-mesenchymal transformation-related transcription factors in peritoneal metastases

Metastasis is the leading cause of mortality in patients with malignant tumors, particularly characterized by peritoneal metastases originating from gastric, ovarian, and colorectal cancers. Regarded as the terminal phase of tumor progression, peritoneal metastasis presents limited therapeutic avenues and is associated with a dismal prognosis for patients. The epithelial-mesenchymal transition (EMT) is a crucial phenomenon in which epithelial cells undergo significant changes in both morphology and functionality, transitioning to a mesenchymal-like phenotype. This transition plays a pivotal role in facilitating tumor metastasis, with transcription factors being key mediators of EMT's effects. Consequently, we provide a retrospective summary of the efforts to identify specific targets among EMT-related transcription factors, aimed at modulating the onset and progression of peritoneal metastatic cancer. This summary offers vital theoretical underpinnings for developing treatment strategies against peritoneal metastasis.

Development of stemness-related signature to optimize prognosis prediction and identify XMD8-85 as a novel therapeutic compound for glioma

Glioma is a highly invasive and aggressive type of brain cancer with poor treatment response. Stemness-related transcription factors form a regulatory network that sustains the malignant phenotype of gliomas. We conducted an integrated analysis of stemness-related transcription factors using The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) datasets, established the characteristics of stemness-related transcription factors, including Octamer-Binding Protein 4 (OCT4), Meis Homeobox 1 (MEIS1), E2F Transcription Factor 1 (E2F1), Transcription Factor CP2 Like 1 (TFCP2L1), and RUNX Family Transcription Factor 1 (RUNX1). The characteristic of stemness-related transcription factors was identified as an independent prognostic factor for glioma patients. Patients in the high-risk group have a worse prognosis than those in the low-risk group. The glioma microenvironment in the high-risk group exhibited a more active immune status. Single-cell level analysis revealed that stem cell-like cells exhibited stronger intercellular communication than glioma cells. Meanwhile, patients in different risk stratification exhibited varying sensitivities to immunotherapy and small molecule drug therapy. XMD8-85 was more effective in the high-risk group, and its antitumor effects were validated both in vivo and in vitro. Our results indicate that this prognostic feature will assist clinicians in predicting the prognosis of glioma patients, guiding immunotherapy and personalized treatment, as well as the potential clinical application of XMD8-85 in glioma treatment, and helping to develop effective treatment strategies.

E2F1 Facilitates the Proliferation and Stemness of Gastric Cancer Cells by Activating CDC25B Transcription and Modulating the MAPK Pathway

Gastric cancer (GC) is a health problem that concerns people around the world. CDC25B is an essential cell cycle regulatory factor that is overexpressed in a variety of tumor cells. CDC25B plays a vital part in the progression and proliferation of malignant tumors. However, it is not yet clear that how CDC25B affects the stemness of GC cells. The study used bioinformatics to detect the expression of E2F1 and CDC25B in GC tissues and their correlation, as well as pathways enriched by CDC25B. We detected the expression of E2F1 and CDC25B in GC cell lines using quantitative reverse transcription polymerase chain reaction and tested the combination relationship between E2F1 and CDC25B using chromatin immunoprecipitation (ChIP) and dual-luciferase assays. We measured cell viability using CCK-8 assay, evaluated sphere-forming efficiency using sphere formation assay, and determined cell proliferation ability using colony formation assay. We also analyzed the expression of stemness markers and MAPK pathway-related proteins using western blot. In GC tissues and cells, CDC25B was upregulated. Silencing CDC25B could affect the MAPK pathway, thereby repressing the proliferation and stemness of GC cells. As predicted by bioinformatics, CDC25B had an upstream transcription factor, E2F1, which also had a high expression level in GC. Dual-luciferase and ChIP assays confirmed the combination relationship between the two. Rescue experiments uncovered that overexpression of CDC25B could reverse the impact induced by E2F1 knockdown on proliferation and stemness of cells. In conclusion, E2F1 could activate CDC25B transcription to regulate the MAPK pathway and enhance the proliferation and stemness of GC cells. We revealed a potential regulatory pathway of stemness of GC cells that was mediated by CDC25B, providing new ideas for improving and innovating GC treatment.

MicroRNA-145 Gene Modification Enhances the Retention of Bone Marrow-Derived Mesenchymal Stem Cells within Corpus Cavernosum by Targeting Krüppel-Like Factor 4

PURPOSE

The poor retention and ambiguous differentiation of stem cells (SCs) within corpus cavernosum (CC) limit the cell application in erectile dysfunction (ED). Herein, the effects and mechanism of microRNA-145 (miR-145) gene modification on modulating the traits and fate of bone marrow-derived mesenchymal stem cells (BMSCs) were investigated.

MATERIALS AND METHODS

The effects of miR-145 on cell apoptosis, proliferation, migration, and differentiation were determined by flow cytometry, cell counting kit-8, transwell assays and myogenic induction. Then, the age-related ED rats were recruited to four groups including phosphate buffer saline, BMSC, vector-BMSC, overexpressed-miR-145-BMSC groups. After cell transplantation, the CC were harvested and prepared to demonstrate the retention and differentiation of BMSCs by immunofluorescent staining. Then, the target of miR-145 was verified by quantitative real-time polymerase chain reaction and immunohistochemical. After that, APTO-253, as an inducer of Krüppel-like factor 4 (KLF4), was introduced for rescue experiments in corpus cavernosum smooth muscle cells (CCSMCs) under the co-culture system.

RESULTS

In vitro, miR-145 inhibited the migration and apoptosis of BMSCs and promoted the differentiation of BMSCs into smooth muscle-like cells with stronger contractility. In vivo, the amount of 5-ethynyl-2'-deoxyuridine (EdU)+cells within CC was significantly enhanced and maintained in the miR-145 gene modified BMSC group. The EdU/CD31 co-staning was detected, however, no co-staining of EdU/α-actin was observed. Furthermore, miR-145, which secreted from the gene modified BMSCs, dampened the expression of KLF4. However, the effects of miR-145 on CCSMCs could be rescued by APTO-253.

CONCLUSIONS

Overall, miR-145 modification prolongs the retention of the transplanted BMSCs within the CC, and this effect might be attributed to the modulation of the miR-145/KLF4 axis. Consequently, our findings offer a promising and innovative strategy to enhance the local stem cell-based treatments.

Long non-coding RNA RAD51-AS1 promotes the tumorigenesis of ovarian cancer by elevating EIF5A2 expression

PURPOSE

The present study aims to determine the molecular mechanism mediated by RAD51 antisense RNA 1 (RAD51-AS1) in ovarian cancer (OvCA).

METHODS

The data associated with RAD51-AS1 in OvCA were obtained from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database. Relative expression of RAD51-AS1 was detected. Determination of cell proliferation, metastasis, and invasion was performed by cell counting, colony formation, would-healing, and transwell invasion assays. Protein levels were detected by western blotting. The molecular mechanism mediated by RAD51-AS1 was predicted by bioinformatics analysis and verified by dual-luciferase reporter assays. Subcutaneous tumorigenesis models were used to confirm the function of RAD51-AS1 in vivo.

RESULTS

Data from TCGA and GEO showed that RAD51-AS1 was associated with poor prognosis in OvCA patients and DNA repair, cell cycle, focal adhesion, and apoptosis in SKOV3.ip cells. High levels of RAD51-AS1 were detected in OvCA cells. Overexpressing RAD51-AS1 enhanced the proliferative, invading, and migratory capabilities of OvCA cells in vitro while silencing RAD51-AS1 exhibited the opposite effects. Mechanically, RAD51-AS1 elevated eukaryotic initiation factor 5A2 (EIF5A2) expression as a sponge for microRNA (miR)-140-3p. Finally, the role of RAD51-AS1 was verified by subcutaneous tumorigenesis models.

CONCLUSION

RAD51-AS1 promoted OvCA progression by the regulation of the miR-140-3p/EIF5A2 axis, which illustrated the potential therapeutic target for OvCA.

Targeting eIF5A2 reduces invasion and reverses chemoresistance in SCC-9 cells in vitro

BACKGROUND AND AIMS

Eukaryotic translation initiation factor 5A2 (EIF5A2) has been reported to be involved in metastasis and chemotherapy resistance in many human cancers. However, the effect and mechanism of EIF5A2 in oral cancer cells are unknown. Here, we investigated the effects of targeting EIF5A2 on chemotherapy resistance in oral cancer cells in vitro.

METHODS

By using a lentiviral system, we investigated the effects of targeting EIF5A2 on the invasion, migration, growth, and chemosensitivity of SCC-9 cells to CDDP in vitro. Through the method of gene intervention, we explore the role of pro-apoptotic Bim and epithelial and mesenchymal marker E-cadherin protein in this process and the regulation of EIF5A2 on Bim and E-cadherin.

RESULTS

Targeting EIF5A2 reduces invasion and migration in SCC-9 cells partly through upregulation of E-cadherin expression; Targeting EIF5A2 promotes cell apoptosis and inhibits cell survival as well as increasing chemosensitivity in SCC-9 cells through upregulation of Bim expression.

CONCLUSION

EIF5A2 may be a novel potential therapeutic target for oral cancer by upregulation of Bim and E-cadherin.

Black Phosphorus Accelerates Bone Regeneration Based on Immunoregulation

A fundamental understanding of inflammation and tissue healing suggests that the precise regulation of the inflammatory phase, both in terms of location and timing, is crucial for bone regeneration. However, achieving the activation of early inflammation without causing chronic inflammation while facilitating quick inflammation regression to promote bone regeneration continues to pose challenges. This study reveals that black phosphorus (BP) accelerates bone regeneration by building an osteogenic immunological microenvironment. BP amplifies the acute pro-inflammatory response and promotes the secretion of anti-inflammatory factors to accelerate inflammation regression and tissue regeneration. Mechanistically, BP creates an osteoimmune-friendly microenvironment by stimulating macrophages to express interleukin 33 (IL-33), amplifying the inflammatory response at an early stage, and promoting the regression of inflammation. In addition, BP-mediated IL-33 expression directly promotes osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), which further facilitates bone repair. To the knowledge, this is the first study to reveal the immunomodulatory potential of BP in bone regeneration through the regulation of both early-stage inflammatory responses and later-stage inflammation resolution, along with the associated molecular mechanisms. This discovery serves as a foundation for the clinical use of BP and is an efficient approach for managing the immune microenvironment during bone regeneration.

Genetic and Functional Modifications Associated with Ovarian Cancer Cell Aggregation and Limited Culture Conditions

The aggregation of cancer cells provides a survival signal for disseminating cancer cells; however, the underlying molecular mechanisms have yet to be elucidated. Using qPCR gene arrays, this study investigated the changes in cancer-specific genes as well as genes regulating mitochondrial quality control, metabolism, and oxidative stress in response to aggregation and hypoxia in our progressive ovarian cancer models representing slow- and fast-developing ovarian cancer. Aggregation increased the expression of anti-apoptotic, stemness, epithelial-mesenchymal transition (EMT), angiogenic, mitophagic, and reactive oxygen species (ROS) scavenging genes and functions, and decreased proliferation, apoptosis, metabolism, and mitochondrial content genes and functions. The incorporation of stromal vascular cells (SVF) from obese mice into the spheroids increased DNA repair and telomere regulatory genes that may represent a link between obesity and ovarian cancer risk. While glucose had no effect, glutamine was essential for aggregation and supported proliferation of the spheroid. In contrast, low glucose and hypoxic culture conditions delayed adhesion and outgrowth capacity of the spheroids independent of their phenotype, decreased mitochondrial mass and polarity, and induced a shift of mitochondrial dynamics towards mitophagy. However, these conditions did not reduce the appearance of polarized mitochondria at adhesion sites, suggesting that adhesion signals that either reversed mitochondrial fragmentation or induced mitobiogenesis can override the impact of low glucose and oxygen levels. Thus, the plasticity of the spheroids' phenotype supports viability during dissemination, allows for the adaptation to changing conditions such as oxygen and nutrient availability. This may be critical for the development of an aggressive cancer phenotype and, therefore, could represent druggable targets for clinical interventions.

Deregulated E2F Activity as a Cancer-Cell Specific Therapeutic Tool

The transcription factor E2F, the principal target of the tumor suppressor pRB, plays crucial roles in cell proliferation and tumor suppression. In almost all cancers, pRB function is disabled, and E2F activity is enhanced. To specifically target cancer cells, trials have been undertaken to suppress enhanced E2F activity to restrain cell proliferation or selectively kill cancer cells, utilizing enhanced E2F activity. However, these approaches may also impact normal growing cells, since growth stimulation also inactivates pRB and enhances E2F activity. E2F activated upon the loss of pRB control (deregulated E2F) activates tumor suppressor genes, which are not activated by E2F induced by growth stimulation, inducing cellular senescence or apoptosis to protect cells from tumorigenesis. Deregulated E2F activity is tolerated in cancer cells due to inactivation of the ARF-p53 pathway, thus representing a feature unique to cancer cells. Deregulated E2F activity, which activates tumor suppressor genes, is distinct from enhanced E2F activity, which activates growth-related genes, in that deregulated E2F activity does not depend on the heterodimeric partner DP. Indeed, the ARF promoter, which is specifically activated by deregulated E2F, showed higher cancer-cell specific activity, compared to the E2F1 promoter, which is also activated by E2F induced by growth stimulation. Thus, deregulated E2F activity is an attractive potential therapeutic tool to specifically target cancer cells.

Genistein Restricts the Epithelial Mesenchymal Transformation (EMT) and Stemness of Hepatocellular Carcinoma via Upregulating miR-1275 to Inhibit the EIF5A2/PI3K/Akt Pathway

Simple Summary

Genistein is a natural phytoestrogen with various antitumor effects. Our study focused on exploring the mechanisms of microRNAs and genistein to inhibit the epithelial mesenchymal transformation (EMT) and stemness of hepatocellular carcinoma (HCC). We found that miR-1275 was more highly expressed in HCC cells treated with genistein compared with the control. Then, we performed series functional experiments to explore the relationship between genistein and miR-1275 in HCC. The inhibition of genistein on HCC cells was enhanced by the increase in treatment time and dose, and miR-1275 can be raised by genistein. The overall survival and recurrence-free survival of HCC patients with low expressed miR-1275 were lower than those of those with high expression levels. The experimental results exhibited that genistein and miR-1275 can both significantly suppress the proliferation, migration, invasion, metastasis, EMT and stemness of HCC. Moreover, the inhibition can be further enhanced with the co-existence of miR-1275 mimic and genistein. Finally, we demonstrated that miR-1275 can inhibit the EMT and stemness of HCC via inhibiting the EIF5A2/PI3K/Akt pathway. Our findings proved that genistein can inhibit the EIF5A2/PI3K/Akt pathway by upregulating miR-1275 so as to attenuate the EMT and stemness of HCC cells to restrict their progression and metastasis.

Abstract

Purpose: Genistein is a natural phytoestrogen with various antitumor effects. In recent years, some microRNAs (miRNA) in cancer cells have been reported to be regulated by genistein. Our study focused on exploring the mechanisms of miRNA upregulation to inhibit the epithelial mesenchymal transformation (EMT) and stemness of hepatocellular carcinoma (HCC). Patients and Methods: MiR-1275 was discovered by the transcriptome sequencing of miRNA expression profiles in HepG2 cells treated with genistein or DMSO as a control. Then, we performed series functional experiments in vitro and vivo to explore the relationship between genistein and miR-1275 in HCC. The target gene (Eukaryotic initiation factor 5A2, EIF5A2) of miR-1275 was predicted by databases and finally determined by a dual luciferase reporter assay. The downstream signaling pathway of EIF5A2 was assessed by bioinformatics analysis and Western blot. Results: the inhibition of genistein on the viability of HCC cells was enhanced by the increase in treatment time and dose, but it had no obvious inhibitory effect on normal hepatocytes (QSG-7701). Through qRT-PCR and transcriptome sequencing, we discovered that miR-1275 was lowly expressed in HCC, and it can be raised by genistein. The overall survival (OS) and recurrence-free survival (RFS) of HCC patients with lowly expressed miR-1275 were lower than those of those with high expression levels. In vitro and vivo experiments exhibited that genistein and the overexpression of miR-1275 can both significantly suppress the proliferation, migration, invasion, metastasis, EMT and stemness of HCC. Moreover, the inhibition can be further enhanced when miR-1275 mimic and genistein exist together. Finally, we demonstrated that miR-1275 can inhibit the epithelial mesenchymal transformation (EMT) and stemness of HCC via inhibiting the EIF5A2/PI3K/Akt pathway. Conclusion: Our findings proved that genistein can inhibit the EIF5A2/PI3K/Akt pathway by upregulating miR-1275 so as to attenuate the EMT and stemness of HCC cells to restrict their progression and metastasis.

High TRB3 expression induces chondrocyte autophagy and senescence in osteoarthritis cartilage

Objective: Osteoarthritis is closely related to aging. Tribbles homologue 3 (TRB3) is found to display age-related expression and contributes to the regulation of cell proliferation, differentiation and fibrosis. In this study, we aimed to investigate the potential involvement of TRB3 in cartilage autophagy and aging in osteoarthritis.

Methods: Cartilage tissue samples were collected from osteoarthritis patients who received joint replacement and cadaveric donors. In osteoarthritis cartilage tissue, we analyzed autophagy- and senescence-associated proteins using immunohistochemistry and western blot (WB), in vitro, to confirm the role played by TRB3 in the process of autophagy, cell senescence, and inflammation, small interfering RNA (siRNA) was used for TRB3 knockdown in cells.

Results: We found increased level of p62, decreased level of microtubule-associated protein 1A/1B-light chain 3 (LC3) and beclin-1 in cartilage, and increased level of p16 and p21 in tissue samples collected from osteoarthritis patients, indicating decreased autophagy and increased cell senescence. TRB3 knockdown significantly rescued, in vitro, the reduced autophagy and elevated cell senescence in human chondrocyte.

Conclusions: Interfering with TRB3 expression in cartilage may serve as a target in the prevention and treatment of age-related osteoarthritis.

Initiation and elongation factor co-expression correlates with recurrence and survival in epithelial ovarian cancer

High grade epithelial ovarian cancer (EOC) represents a diagnostic and therapeutic challenge due to its aggressive features and short recurrence free survival (RFS) after primary treatment. Novel targets to inform our understanding of the EOC carcinogenesis in the translational machinery can provide us with independent prognostic markers and provide drugable targets. We have identified candidate eukaryotic initiation factors (eIF) and eukaryotic elongation factors (eEF) in the translational machinery for differential expression in EOC through in-silico analysis. We present the analysis of 150 ovarian tissue microarray (TMA) samples on the expression of the translational markers eIF2α, eIF2G, eIF5 (eIF5A and eIF5B), eIF6 and eEF1A1. All translational markers were differentially expressed among non-neoplastic ovarian samples and tumour samples (borderline tumours and EOC). In EOC, expression of eIF5A was found to be significantly correlated with recurrence free survival (RFS) and expression of eIF2G and eEF1A1 with overall survival (OS). Expression correlation among factor subunits showed that the correlation of eEF1A1, eIF2G, EIF2α and eIF5A were significantly interconnected. eIF5A was also correlated with eIF5B and eIF6. Our study demonstrates that EOCs have different translational profile compared to benign ovarian tissue and that eIF5A is a central dysregulated factor of the translation machinery.

The osteoprotective role of USP26 in coordinating bone formation and resorption

Bone homeostasis is maintained through a balance of bone formation by osteoblasts and bone resorption by osteoclasts. Ubiquitin-specific proteases (USPs) are involved in regulating bone metabolism by preserving bone formation or antagonizing bone resorption. However, the specific USPs that maintain bone homeostasis by orchestrating bone formation and bone resorption simultaneously are poorly understood. Here, we identified USP26 as a previously unknown regulator of bone homeostasis that coordinates bone formation and resorption. Mechanistically, USP26 stabilizes β-catenin to promote the osteogenic activity of mesenchymal cells (MSCs) and impairs the osteoclastic differentiation of bone myelomonocytes (BMMs) by stabilizing inhibitors of NF-κBα (IκBα). Gain-of-function experiments revealed that Usp26 supplementation significantly increased bone regeneration in bone defects in aged mice and decreased bone loss resulting from ovariectomy. Taken together, these data show the osteoprotective effect of USP26 via the coordination of bone formation and resorption, suggesting that USP26 represents a potential therapeutic target for osteoporosis.

Emerging Role of E2F Family in Cancer Stem Cells

The E2F family of transcription factors (E2Fs) consist of eight genes in mammals. These genes encode ten proteins that are usually classified as transcriptional activators or transcriptional repressors. E2Fs are important for many cellular processes, from their canonical role in cell cycle regulation to other roles in angiogenesis, the DNA damage response and apoptosis. A growing body of evidence demonstrates that cancer stem cells (CSCs) are key players in tumor development, metastasis, drug resistance and recurrence. This review focuses on the role of E2Fs in CSCs and notes that many signals can regulate the activities of E2Fs, which in turn can transcriptionally regulate many different targets to contribute to various biological characteristics of CSCs, such as proliferation, self-renewal, metastasis, and drug resistance. Therefore, E2Fs may be promising biomarkers and therapeutic targets associated with CSCs pathologies. Finally, exploring therapeutic strategies for E2Fs may result in disruption of CSCs, which may prevent tumor growth, metastasis, and drug resistance.