From Interaction to Intervention: How Mesenchymal Stem Cells Affect and Target Triple-Negative Breast Cancer

Mesenchymal stem cells modulate breast cancer progression through their secretome by downregulating ten-eleven translocation 1

Mesenchymal stem cells (MSCs) have emerged as crucial players within the tumor microenvironment (TME), contributing through their paracrine secretome. Depending on the context, the MSC-derived secretome can either support or inhibit tumor growth. This study investigates the role of MSC-derived secretome in modulating breast cancer (BC) cell behavior, with a focus on ten-eleven translocation 1 (TET1), a DNA demethylase with known oncogenic properties in triple-negative breast cancer (TNBC). We first isolated and characterized human bone marrow-derived MSCs, and then assessed the impact of their secretome on BC cells. Treatment with the MSC-derived secretome significantly inhibited the proliferation and migration of both MDA-MB-231 and MCF-7 BC cell lines, resulting in reduced cell viability and migration rates compared to control cells. Western blot analyses revealed downregulation of Cyclin D1 and c-Myc, along with decreased expression of N-cadherin and increased expression of E-cadherin, indicating potential inhibition of the epithelial-to-mesenchymal transition. Differential gene expression analyses highlighted TET1 as significantly upregulated in TNBC tissues compared to normal samples. Further experiments confirmed that the MSC-derived secretome downregulated TET1 expression in BC cells, as evidenced by RT-qPCR and western blot analyses. To explore TET1's functional role, we silenced TET1 with siRNAs, observing cell cycle arrest and enhanced apoptosis-effects that mirrored those seen with MSC-secretome treatment. Notably, TET1 knockdown also increased MDA-MB-231 cell sensitivity to cisplatin, suggesting a role for TET1 in chemoresistance. These findings provide insight into the ability of MSCs to modulate BC cell progression through their secretome, highlighting the involvement of TET1 downregulation in inhibiting BC cell progression and enhancing cisplatin chemosensitivity. The MSC-derived secretome thus holds promise as an innovative, cell-free therapeutic approach in BC treatment.

Solid Lipid Nanoparticles, an Alternative for the Treatment of Triple-Negative Breast Cancer

Within the field of nanomedicine, which is revolutionizing cancer treatment, solid lipid nanoparticles (SLNs) have shown advantages over conventional chemotherapy when tested on cancer cells in preclinical studies. SLNs have proven to be an innovative strategy for the treatment of triple-negative breast cancer cells, providing greater efficiency than existing treatments in various studies. The encapsulation of antineoplastic drugs in SLNs has facilitated a sustained, controlled, and targeted release, which enhances therapeutic efficiency and reduces adverse effects. Moreover, the surface of SLNs can be modified to increase efficiency. For instance, the coating of these particles with polyethylene glycol (PEG) decreases their opsonization, resulting in a longer life in the circulatory system. The creation of positively charged cationic SLNs (cSLNs), achieved by the utilization of surfactants or ionic lipids with positively charged structural groups, increases their affinity for cell membranes and plasma proteins. Hyaluronic acid has been added to SLNs so that the distinct pH of tumor cells would stimulate the release of the drug and/or genetic material. The current review summarizes the recent research on SLNs, focusing on the encapsulation and transport of therapeutic agents with a cytotoxic effect on triple-negative breast cancer.

Exploring the interplay between triple-negative breast cancer stem cells and tumor microenvironment for effective therapeutic strategies

Triple-negative breast cancer (TNBC) is a highly aggressive and metastatic malignancy with poor treatment outcomes. The interaction between the tumor microenvironment (TME) and breast cancer stem cells (BCSCs) plays an important role in the development of TNBC. Owing to their ability of self-renewal and multidirectional differentiation, BCSCs maintain tumor growth, drive metastatic colonization, and facilitate the development of drug resistance. TME is the main factor regulating the phenotype and metastasis of BCSCs. Immune cells, cancer-related fibroblasts (CAFs), cytokines, mesenchymal cells, endothelial cells, and extracellular matrix within the TME form a complex communication network, exert highly selective pressure on the tumor, and provide a conducive environment for the formation of BCSC niches. Tumor growth and metastasis can be controlled by targeting the TME to eliminate BCSC niches or targeting BCSCs to modify the TME. These approaches may improve the treatment outcomes and possess great application potential in clinical settings. In this review, we summarized the relationship between BCSCs and the progression and drug resistance of TNBC, especially focusing on the interaction between BCSCs and TME. In addition, we discussed therapeutic strategies that target the TME to inhibit or eliminate BCSCs, providing valuable insights into the clinical treatment of TNBC.

Synergistic effects of photodynamic therapy and chemotherapy: Activating the intrinsic/extrinsic apoptotic pathway of anoikis for triple-negative breast cancer treatment

Triple-negative breast cancer (TNBC) is a highly invasive and metastatic subtype of breast cancer that often recurs after surgery. Herein, we developed a cyclodextrin-based tumor-targeted nano delivery system that incorporated the photosensitizer chlorin e6 (Ce6) and the chemotherapeutic agent lonidamine (LND) to form the R6RGD-CMβCD-se-se-Ce6/LND nanoparticles (RCC/LND NPS). This nanosystem could target cancer cells, avoid lysosomal degradation and further localize within the mitochondria. The RCC/LND NPS had pH and redox-responsive to control the release of Ce6 and LND. Consequently, the nanosystem had a synergistic effect by effectively alleviating hypoxia, enhancing the production of cytotoxic reactive oxygen species (ROS) and amplifying the efficacy of photodynamic therapy (PDT). Furthermore, the RCC/LND NPS + light weakened anoikis resistance, disrupted extracellular matrix (ECM), activated both the intrinsic apoptotic pathway (mitochondrial pathway) and extrinsic apoptotic pathway (receptor death pathway) of anoikis. In addition, the nanosystem showed significant anti-TNBC efficacy in vivo. These findings collectively demonstrated that RCC/LND NPS + light enhanced the anticancer effects, induced anoikis and inhibited tumor cell migration and invasion through a synergistic effect of chemotherapy and PDT. Overall, this study highlighted the promising potential of the RCC/LND NPS + light for the treatment of TNBC.

Synergistic effect of human uterine cervical mesenchymal stem cell secretome and paclitaxel on triple negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer and, despite its adverse effects, chemotherapy is the standard systemic treatment option for TNBC. Since, it is of utmost importance to consider the combination of different agents to achieve greater efficacy and curability potential, MSC secretome is a possible innovative alternative.

METHODS

In the present study, we proposed to investigate the anti-tumor effect of the combination of a chemical agent (paclitaxel) with a complex biological product, secretome derived from human Uterine Cervical Stem cells (CM-hUCESC) in TNBC.

RESULTS

The combination of paclitaxel and CM-hUCESC decreased cell proliferation and invasiveness of tumor cells and induced apoptosis in vitro (MDA-MB-231 and/or primary tumor cells). The anti-tumor effect was confirmed in a mouse tumor xenograft model showing that the combination of both products has a significant effect in reducing tumor growth. Also, pre-conditioning hUCESC with a sub-lethal dose of paclitaxel enhances the effect of its secretome and in combination with paclitaxel reduced significantly tumor growth and even allows to diminish the dose of paclitaxel in vivo. This effect is in part due to the action of extracellular vesicles (EVs) derived from CM-hUCESC and soluble factors, such as TIMP-1 and - 2.

CONCLUSIONS

In conclusion, our data demonstrate the synergistic effect of the combination of CM-hUCESC with paclitaxel on TNBC and opens an opportunity to reduce the dose of the chemotherapeutic agents, which may decrease chemotherapy-related toxicity.

Construction and in vitro evaluation of pH-sensitive nanoparticles to reverse drug resistance of breast cancer stem cells

Breast cancer is a major threat to safety and health of women. The breast cancer stem cells (BCSCs) have multi-drug resistance to chemotherapy drugs, which leads to chemotherapy failure. We proposed a strategy of delivery of tumor-killing drugs and a resistance reversal agent, to enhance inhibition of BCSCs. Here, schisandrin B (SchB)/AP NPs are constructed using acid-grafted-poly (β-amino ester) (ATRA-g-PBAE, AP) grafted polymer nanoparticle encapsulated SchB, with pH-sensitive release function. This drug delivery system has good pharmacological properties and can increase the SchB release with the decrease of pH. The NPs showed cytotoxic effects in reversing ATRA resistance to BCSCs. Lysosomal escape was achieved when the nanoparticles were taken up by BCSCs. In addition, we found that NPs may reverse MDR by inhibiting the expression of P-glycoprotein (P-gp) and affecting the energy supply of drug efflux. This study provides a nanodelivery therapy strategy that reverses BCSCs multidrug resistance (MDR) and demonstrates that it did so by interfering with cancer cell energy metabolism. Therefore, the co-delivery strategy of ATRA and SchB provides a new option for the treatment of breast cancer.