Preclinical and Clinical Trials of New Treatment Strategies Targeting Cancer Stem Cells in Subtypes of Breast Cancer

FAM20C Promotes Papillary Thyroid Cancer Proliferation and Metastasis via Epithelial-Mesenchymal Transition

Thyroid cancer (TC) is the prevailing malignancy that impacts the endocrine system, accounting for 1% of all recently diagnosed malignancies in humans. The incidence of TC has been continuously increasing, which can be attributed to advancements in clinical diagnostic technology. However, the mechanisms behind the development of TC are still not well understood. TC is classified into four pathological forms: medullary thyroid cancer, papillary thyroid cancer (PTC), follicular thyroid cancer, and poorly differentiated TC. PTC constitutes more than 80% of all TC cases globally. Current research indicates that complex genetic and cellular processes could be responsible for the growth and spread of TC. Next-generation sequencing (RNA-seq) of 79 PTC samples and their corresponding normal thyroid tissues was performed to investigate the molecular mechanisms of PTC. An analysis of RNA-seq data from a local cohort from The Cancer Genome Atlas (TCGA) revealed that, compared with normal tissues, PTC tissues presented elevated FAM20C expression levels. In vitro, the function of FAM20C was validated with small interfering RNA (siRNA). Gene set enrichment analysis (GSEA) revealed the pathways influenced by FAM20C. A western blot experiment was used to investigate protein expression levels associated with epithelial‒mesenchymal transition (EMT). In conclusion, by regulating EMT, FAM20C facilitates PTC cell proliferation and metastasis.

Regional Hereditary Cancer Program in Chile: A scalable model of genetic counseling and molecular diagnosis to improve clinical outcomes for patients with hereditary cancer across Latin America

BACKGROUND

Breast cancer is a leading cause of cancer-related mortality worldwide, with hereditary forms accounting for approximately 10% of cases. In Chile, significant gaps exist in genetic counseling and testing, particularly within the public health system. This study presents the implementation and outcomes of the first regional hereditary cancer program in the Maule region of Chile, aimed at improving detection and management of hereditary breast cancer.

METHODS

A cohort of 48 high-risk breast cancer patients from the Hospital Regional de Talca received genetic counseling and underwent Next-Generation Sequencing multigene panel testing. The program was established through collaboration between multiple institutions, leveraging telemedicine and outsourcing sequencing analysis to address regional gaps.

RESULTS

Pathogenic or likely pathogenic variants were identified in 12% of patients, including in BRCA1, BRCA2, TP53, and PALB2. Notably, novel pathogenic variants in BRCA1 (rs80357505) and TP53 (rs1131691022) were discovered, highlighting the unique genetic landscape of the Chilean population. Additionally, 70 variants of uncertain significance were found across 42 genes, particularly in FAN1, MSH6, and FANCI, underscoring the need for further research. The program's collaborative approach effectively bridged critical gaps in genetic services, providing high-quality care within the public health system despite limited resources.

CONCLUSIONS

The Regional Hereditary Cancer Program addresses significant gaps in genetic counseling and testing in Chile's public health system. This scalable model enhances early detection and personalized treatment for hereditary cancer patients and could be adapted to other regions across Latin America.

Targeting cancer stem cells by TPA leads to inhibition of refractory sarcoma and extended overall survival

Refractory cancer recurrence in patients is a serious challenge in modern medicine. Tumor regrowth in a more aggressive and invasive drug-resistant form is caused by a specific sub-population of tumor cells defined as cancer stem cells (CSCs). While the role of CSCs in cancer relapse is recognized, the signaling pathways of CSCs-driven chemoresistance are less well understood. Moreover, there are no effective therapeutic strategies that involve specific inhibition of CSCs responsible for cancer recurrence and drug resistance. There is a clinical need to develop new therapies for patients with refractory sarcomas, particularly fibrosarcoma. These aggressive tumors, with poor overall survival, do not respond to conventional therapies. Standard systemic chemotherapy for these tumors includes doxorubicin (DOX). A Tyr peptide analog (TPA), developed in our laboratory, specifically targets CSCs by drastically reducing expression of the polycomb group protein enhancer of zester (EZH2) and its downstream targets, specifically ALDH1A1 and Nanog. In vivo experiments demonstrated that TPA inhibited tumor growth in nu/nu mice with relapsed DOX-treated fibrosarcoma 7-fold and led to improved overall (2-fold) survival. In an experimental metastatic model, the combination of TPA with DOX treatment extended overall survival 3-fold, suggesting that targeting CSC can become an effective strategy in the treatment of refractory/relapse fibrosarcoma.

Revolutionizing medicine: recent developments and future prospects in stem-cell therapy

Stem-cell therapy is a revolutionary frontier in modern medicine, offering enormous capacity to transform the treatment landscape of numerous debilitating illnesses and injuries. This review examines the revolutionary frontier of treatments utilizing stem cells, highlighting the distinctive abilities of stem cells to undergo regeneration and specialized cell differentiation into a wide variety of phenotypes. This paper aims to guide researchers, physicians, and stakeholders through the intricate terrain of stem-cell therapy, examining the processes, applications, and challenges inherent in utilizing stem cells across diverse medical disciplines. The historical journey from foundational contributions in the late 19th and early 20th centuries to recent breakthroughs, including ESC isolation and iPSC discovery, has set the stage for monumental leaps in medical science. Stem cells' regenerative potential spans embryonic, adult, induced pluripotent, and perinatal stages, offering unprecedented therapeutic opportunities in cancer, neurodegenerative disorders, cardiovascular ailments, spinal cord injuries, diabetes, and tissue damage. However, difficulties, such as immunological rejection, tumorigenesis, and precise manipulation of stem-cell behavior, necessitate comprehensive exploration and innovative solutions. This manuscript summarizes recent biotechnological advancements, critical trial evaluations, and emerging technologies, providing a nuanced understanding of the triumphs, difficulties, and future trajectories in stem cell-based regenerative medicine. Future directions, including precision medicine integration, immune modulation strategies, advancements in gene-editing technologies, and bioengineering synergy, offer a roadmap in stem cell treatment. The focus on stem-cell therapy's potential highlights its significant influence on contemporary medicine and points to a future in which individualized regenerative therapies will alleviate various medical disorders.

The pH-sensitive chondroitin sulphate-based nanoparticles for co-delivery of doxorubicin and berberine enhance the treatment of breast cancer

In the tumor microenvironment (TME), cancer associated fibroblasts (CAFs) facilitate drug resistance and tumor metastasis. Therefore, more and more attention has been focused on the regulation of TME by preventing the cross-talk between tumor cells and CAFs in the treatment of breast cancer. In this study, we have combined the benefits of deep drug penetration, pH sensitivity, and tumor-targeting delivery to prepare chondroitin sulphate (CS)-based nanomicelles (BBR/CS-DOX) for the co-delivery of doxorubicin (DOX) and berberine (BBR). A unique MCF-7 + MRC-5 co-cultured cell model and 4 T1 + NIH3T3 co-implanted mice model, were established to simulate the TME of breast cancer (BC). As expected, BBR/CS-DOX could accumulate in tumor egion, be taken up by both tumor cells and CAFs, and improve drug absorption and retention. Compared with free drugs, BBR/CS-DOX demonstrated stonger pro-apoptotic and anti-metastatic effect in vitro and in vivo, respectively the histological studies showed that BBR/CS-DOX efficiently prevented the activation of fibroblasts, inhibited extracellular matrix (ECM) deposition, and decreased tumor angiogenesis, showing superior anti-tumor efficacy. In summary, BBR/CS-DOX has the potential to significantly enhance the therapeutic effect of breast cancer through inhibiting the "CAFs-tumor cells" crosstalk, and has promising clinical application prospects.

ALDH and cancer stem cells: Pathways, challenges, and future directions in targeted therapy

Human ALDH comprise 19 subfamilies in which ALDH1A1, ALDH1A3, ALDH3A1, ALDH5A1, ALDH7A1, and ALDH18A1 are implicated in CSC. Studies have shown that ALDH can also be involved in drug resistance and standard chemotherapy regimens are ineffective in treating patients at the stage of disease recurrence. Existing chemotherapeutic drugs eliminate the bulk of tumors but are usually not effective against CSC which express ALDH+ population. Henceforth, targeting ALDH is convincing to treat the patient's post-relapse. Combination therapies that interlink signaling mechanisms seem promising to increase the overall disease-free survival rate. Therefore, targeting ALDH through ALDH inhibitors along with immunotherapies may create a novel platform for translational research. This review aims to fill in the gap between ALDH1 family members in relation to its cell signaling mechanisms, highlighting their potential as molecular targets to sensitize recurrent tumors and bring forward the future development concerning the current progress and draw backs. This review summarizes the role of cancer stem cells and their upregulation by maintaining the tumor microenvironment in which ALDH is specifically highlighted. It discusses the regulation of ALDH family proteins and the crosstalk between ALDH and CSC in relation to cancer metabolism. Furthermore, it establishes the correlation between ALDH involved signaling mechanisms and their specific targeted inhibitors, as well as their functional modularity, bioavailability, and mechanistic role in various cancers.

CD44/PD-L1-mediated networks in drug resistance and immune evasion of breast cancer stem cells: Promising targets of natural compounds

Cancer stem cells (CSCs) significantly interfere with immunotherapy, leading to challenges such as low response rates and acquired resistance. PD-L1 expression is associated with the CSC population's overexpression of CD44. Mounting evidence suggests that the breast cancer stem cell (BCSC) marker CD44 and the immune checkpoint PD-L1 contribute to treatment failure through their networks. Natural compounds can overcome therapy resistance in breast cancer by targeting mechanisms underlying resistance in BCSCs. This review provides an updated insight into the CD44 and PD-L1 networks of BCSCs in mediating metastasis and immune evasion. The review critically examines existing literature, providing a comprehensive understanding of the topic and emphasizing the impact of natural flavones on the signaling pathways of BCSCs. Additionally, the review discusses the potential of natural compounds in targeting CD44 and PD-L1 in breast cancer (BC). Natural compounds consistently show potential in targeting regulatory mechanisms of BCSCs, inducing loss of stemness, and promoting differentiation. They offer a promising approach for developing alternative therapeutic strategies to manage breast cancer.

Inhibition of Cancer Stem-like Cells by Curcumin and Other Polyphenol Derivatives in MDA-MB-231 TNBC Cells

Triple-negative breast cancer (TNBC) accounts for 15% of all breast cancers and is highly aggressive. Despite an initial positive response to chemotherapy, most patients experience rapid disease progression leading to relapse and metastasis. This is attributed to the presence of breast cancer stem cells (BCSCs) within the tumor, which are characterized by self-renewal, pluripotency, and resistance mechanisms. Targeting BCSCs has become critical as conventional therapies fail to eradicate them due to a lack of specific targets. Curcumin, a polyphenol derived from turmeric (Curcuma longa), exhibits anticancer effects against breast cancer cells and BCSCs. The use of curcumin derivatives has been suggested as an approach to overcome the bioavailability and solubility problems of curcumin in humans, thereby increasing its anticancer effects. The aim of this study was to evaluate the cellular and molecular effects of six synthetic compounds derived from the natural polyphenol epigallocatechin gallate (EGCG) (TL1, TL2) and curcumin derivatives (TL3, TL4, TL5, and TL6) on a TNBC mesenchymal stem-like cell line. The activity of the compounds against BCSCs was also determined by a mammosphere inhibition assay and studying different BCSC markers by Western blotting. Finally, a drug combination assay was performed with the most promising compounds to evaluate their potential synergistic effects with the chemotherapeutic agents doxorubicin, cisplatin, and paclitaxel. The results showed that compounds exhibited specific cytotoxicity against the TNBC cell line and BCSCs. Interestingly, the combination of the curcumin derivative TL3 with doxorubicin and cisplatin displayed a synergistic effect in TNBC cells.

3D Bioprinted Tumor-Stroma Models of Triple-Negative Breast Cancer Stem Cells for Preclinical Targeted Therapy Evaluation

Breast cancer stem cells (CSCs) play a pivotal role in therapy resistance and tumor relapse, emphasizing the need for reliable in vitro models that recapitulate the complexity of the CSC tumor microenvironment to accelerate drug discovery. We present a bioprinted breast CSC tumor-stroma model incorporating triple-negative breast CSCs (TNB-CSCs) and stromal cells (human breast fibroblasts), within a breast-derived decellularized extracellular matrix bioink. Comparison of molecular signatures in this model with different clinical subtypes of bioprinted tumor-stroma models unveils a unique molecular profile for artificial CSC tumor models. We additionally demonstrate that the model can recapitulate the invasive potential of TNB-CSC. Surface-enhanced Raman scattering imaging allowed us to monitor the invasive potential of tumor cells in deep z-axis planes, thereby overcoming the depth-imaging limitations of confocal fluorescence microscopy. As a proof-of-concept application, we conducted high-throughput drug testing analysis to assess the efficacy of CSC-targeted therapy in combination with conventional chemotherapeutic compounds. The results highlight the usefulness of tumor-stroma models as a promising drug-screening platform, providing insights into therapeutic efficacy against CSC populations resistant to conventional therapies.

Tumorigenic and tumoricidal properties of exosomes in cancers; a forward look

In recent decades, emerging data have highlighted the critical role of extracellular vesicles (EVs), especially (exosomes) Exos, in the progression and development of several cancer types. These nano-sized vesicles are released by different cell lineages within the cancer niche and maintain a suitable platform for the interchange of various signaling molecules in a paracrine manner. Based on several studies, Exos can transfer oncogenic factors to other cells, and alter the activity of immune cells, and tumor microenvironment, leading to the expansion of tumor cells and metastasis to the remote sites. It has been indicated that the cell-to-cell crosstalk is so complicated and a wide array of factors are involved in this process. How and by which mechanisms Exos can regulate the behavior of tumor cells and non-cancer cells is at the center of debate. Here, we scrutinize the molecular mechanisms involved in the oncogenic behavior of Exos released by different cell lineages of tumor parenchyma. Besides, tumoricidal properties of Exos from various stem cell (SC) types are discussed in detail.

Understanding the mechanistic pathways and clinical aspects associated with protein and gene based biomarkers in breast cancer

Cancer is one of the most widespread and severe diseases with a huge mortality rate. In recent years, the second-leading mortality rate of any cancer globally has been breast cancer, which is one of the most common and deadly cancers found in women. Detecting breast cancer in its initial stages simplifies treatment, decreases death risk, and recovers survival rates for patients. The death rate for breast cancer has risen to 0.024 % in some regions. Sensitive and accurate technologies are required for the preclinical detection of BC at an initial stage. Biomarkers play a very crucial role in the early identification as well as diagnosis of women with breast cancer. Currently, a wide variety of cancer biomarkers have been discovered for the diagnosis of cancer. For the identification of these biomarkers from serum or other body fluids at physiological amounts, many detection methods have been developed. In the case of breast cancer, biomarkers are especially helpful in discovering those who are more likely to develop the disease, determining prognosis at the time of initial diagnosis and choosing the best systemic therapy. In this study we have compiled various clinical aspects and signaling pathways associated with protein-based biomarkers and gene-based biomarkers.

Molecular targets, therapeutic agents and multitasking nanoparticles to deal with cancer stem cells: A narrative review

There is increasing evidence that malignant tumors are initiated and maintained by a sub-population of tumor cells that have similar biological properties to normal adult stem cells. This very small population of Cancer Stem Cells (CSC) comprises tumor initiating cells responsible for cancer recurrence, drug resistance and metastasis. Conventional treatments such as chemotherapy, radiotherapy and surgery, in addition to being potentially toxic and non-specific, may paradoxically increase the population, spread and survival of CSCs. Next-generation sequencing and omics technologies are increasing our understanding of the pathways and factors involved in the development of CSCs, and can help to discover new therapeutic targets against CSCs. In addition, recent advances in nanomedicine have provided hope for the development of optimal specific therapies to eradicate CSCs. Moreover, the use of artificial intelligence and nano-informatics can elucidate new drug targets, and help to design drugs and nanoparticles (NPs) to deal with CSCs. In this review, we first summarize the properties of CSCs and describe the signaling pathways and molecular characteristics responsible for the emergence and survival of CSCs. Also, the location of CSCs within the tumor and the effect of host factors on the creation and maintenance of CSCs are discussed. Newly discovered molecular targets involved in cancer stemness and some novel therapeutic compounds to combat CSCs are highlighted. The optimum properties of anti-CSC NPs, including blood circulation and stability, tumor accumulation and penetration, cellular internalization, drug release, endosomal escape, and aptamers designed for specific targeting of CSCs are covered. Finally, some recent smart NPs designed for therapeutic and theranostic purposes to overcome CSCs are discussed.