Re-Sensitizing Cancer Stem Cells to Conventional Chemotherapy Agents

The Role of Epithelial Cell Adhesion Molecule Cancer Stem Cell Marker in Evaluation of Hepatocellular Carcinoma

Background and Objectives: Hepatocellular carcinoma (HCC) is a prevalent form of malignancy that is characterized by high mortality rates and prognosis that remain suboptimal, largely due to treatment resistance mechanisms. Recent studies have implicated cancer stem cells (CSCs), particularly those expressing epithelial cell adhesion molecule (EpCAM), in HCC progression and resistance. In the present study, we sought to assess EpCAM expression in HCC patients and its correlation with various clinicopathological parameters. Materials and Methods: Tissue samples from 42 HCC patients were subjected to immunohistochemical staining to evaluate EpCAM expression. Clinicopathological data were obtained including the size, grade and stage of tumors, vascular invasion status, alpha-fetoprotein levels, and cirrhosis status. The Chi square and Fisher's exact tests were employed to assess the association between categorical groups. Independent Student-t test or Mann-Whitney U test was used to investigate the association between continuous patient characteristics and survival. Results: Immunohistochemical analysis revealed EpCAM expression in 52.5% of HCC cases. EpCAM-positive tumors exhibited characteristics indicative of aggressive disease, including larger tumor sizes (p = 0.006), greater tumor multiplicity (p = 0.004), higher grades (p = 0.002), more advanced stages (p = 0.003), vascular invasion (p = 0.023), elevated alpha-fetoprotein levels (p = 0.013), and cirrhosis (p = 0.052). Survival analysis demonstrated that EpCAM expression was significantly associated with lower overall rates of survival and higher rates of recurrence in HCC patients. Conclusions: Our findings suggest that EpCAM expression may serve as a prognostic biomarker for HCC with a potential role in patient management. Targeting EpCAM-positive CSCs may represent a promising approach to overcome treatment resistance and improve clinical outcomes in HCC. However, further investigation into the molecular mechanisms underlying EpCAM's role in HCC progression is warranted to facilitate the development of personalized therapeutic interventions.

The MDM2-p53 Axis Represents a Therapeutic Vulnerability Unique to Glioma Stem Cells

The prevention of tumor recurrence by the successful targeting of glioma stem cells endowed with a tumor-initiating capacity is deemed the key to the long-term survival of glioblastoma patients. Glioma stem cells are characterized by their marked therapeutic resistance; however, recent evidence suggests that they have unique vulnerabilities that may be therapeutically targeted. We investigated MDM2 expression levels in glioma stem cells and their non-stem cell counterparts and the effects of the genetic and pharmacological inhibition of MDM2 on the viability of these cells as well as downstream molecular pathways. The results obtained showed that MDM2 expression was substantially higher in glioma stem cells than in their non-stem cell counterparts and also that the inhibition of MDM2, either genetically or pharmacologically, induced a more pronounced activation of the p53 pathway and apoptotic cell death in the former than in the latter. Specifically, the inhibition of MDM2 caused a p53-dependent increase in the expression of BAX and PUMA and a decrease in the expression of survivin, both of which significantly contributed to the apoptotic death of glioma stem cells. The present study identified the MDM2-p53 axis as a novel therapeutic vulnerability, or an Achilles' heel, which is unique to glioma stem cells. Our results, which suggest that non-stem, bulk tumor cells are less sensitive to MDM2 inhibitors, may help guide the selection of glioblastoma patients suitable for MDM2 inhibitor therapy.

Hinokitiol Inhibits Breast Cancer Cells In Vitro Stemness-Progression and Self-Renewal with Apoptosis and Autophagy Modulation via the CD44/Nanog/SOX2/Oct4 Pathway

Breast cancer (BC) represents one of the most prevalent malignant threats to women globally. Tumor relapse or metastasis is facilitated by BC stemness progression, contributing to tumorigenicity. Therefore, comprehending the characteristics of stemness progression and the underlying molecular mechanisms is pivotal for BC advancement. Hinokitiol (β-thujaplicin), a tropolone-related compound abundant in the heartwood of cupressaceous plants, exhibits antimicrobial activity. In our study, we employed three BC cell lines (MDA-MB-231, MCF-7, and T47D) to assess the expression of stemness-, apoptosis-, and autophagy-related proteins. Hinokitiol significantly reduced the viability of cancer cells in a dose-dependent manner. Furthermore, we observed that hinokitiol enhances apoptosis by increasing the levels of cleaved poly-ADP-ribose polymerase (PARP) and phospho-p53. It also induces dysfunction in autophagy through the upregulation of LC3B and p62 protein expression. Additionally, hinokitiol significantly suppressed the number and diameter of cancer cell line spheres by reducing the expression of cluster of differentiation44 (CD44) and key transcription factors. These findings underscore hinokitiol's potential as a therapeutic agent for breast cancer, particularly as a stemness-progression inhibitor. Further research and clinical studies are warranted to explore the full therapeutic potential of hinokitiol in the treatment of breast cancer.

Harnessing Sulforaphane Potential as a Chemosensitizing Agent: A Comprehensive Review

Recent advances in oncological research have highlighted the potential of naturally derived compounds in cancer prevention and treatment. Notably, sulforaphane (SFN), an isothiocyanate derived from cruciferous vegetables including broccoli and cabbage, has exhibited potent chemosensitizing capabilities across diverse cancer types of bone, brain, breast, lung, skin, etc. Chemosensitization refers to the enhancement of cancer cell sensitivity to chemotherapy agents, counteracting the chemoresistance often developed by tumor cells. Mechanistically, SFN orchestrates this sensitization by modulating an array of cellular signaling pathways (e.g., Akt/mTOR, NF-κB, Wnt/β-catenin), and regulating the expression and activity of pivotal genes, proteins, and enzymes (e.g., p53, p21, survivin, Bcl-2, caspases). When combined with conventional chemotherapeutic agents, SFN synergistically inhibits cancer cell proliferation, invasion, migration, and metastasis while potentiating drug-induced apoptosis. This positions SFN as a potential adjunct in cancer therapy to augment the efficacy of standard treatments. Ongoing preclinical and clinical investigations aim to further delineate the therapeutic potential of SFN in oncology. This review illuminates the multifaceted role of this phytochemical, emphasizing its potential to enhance the therapeutic efficacy of anti-cancer agents, suggesting its prospective contributions to cancer chemosensitization and management.

Tumor Microenvironment Heterogeneity, Potential Therapeutic Avenues, and Emerging Therapies

OBJECTIVE

This review describes the comprehensive portrait of tumor microenvironment (TME). Additionally, we provided a panoramic perspective on the transformation and functions of the diverse constituents in TME, and the underlying mechanisms of drug resistance, beginning with the immune cells and metabolic dynamics within TME. Lastly, we summarized the most auspicious potential therapeutic strategies.

RESULTS

TME is a unique realm crafted by malignant cells to withstand the onslaught of endogenous and exogenous therapies. Recent research has revealed many small-molecule immunotherapies exhibiting auspicious outcomes in preclinical investigations. Furthermore, some pro-immune mechanisms have emerged as a potential avenue. With the advent of nanosystems and precision targeting, targeted therapy has now transcended the "comfort zone" erected by cancer cells within TME.

CONCLUSION

The ceaseless metamorphosis of TME fosters the intransigent resilience and proliferation of tumors. However, existing therapies have yet to surmount the formidable obstacles posed by TME. Therefore, scientists should investigate potential avenues for therapeutic intervention and design innovative pharmacological and clinical technologies.

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.