IGF-1 from adipose-derived mesenchymal stem cells promotes radioresistance of breast cancer cells

Ojeok-san enhances platinum sensitivity in ovarian cancer by regulating adipocyte paracrine IGF1 secretion

BACKGROUND

Platinum is a commonly used drug for ovarian cancer (OvCa) treatment, but drug resistance limits its clinical application. This study intended to delineate the effects of adipocytes on platinum resistance in OvCa.

METHODS

OvCa cells were maintained in the adipocyte-conditioned medium. Cell viability and apoptosis were detected by CCK-8 and flow cytometry, separately. Proliferation and apoptosis-related protein expression were assayed by western blot. The IC50 values of cisplatin and carboplatin were determined using CCK-8. IGF1 secretion and expression were assayed via ELISA and western blot, respectively. A xenograft model was established, and pathological changes were detected by H&E staining. Proliferation and apoptosis-associated protein expression was assessed via IHC.

RESULTS

Adipocytes promoted the viability and repressed cell apoptosis in OvCa, as well as enhancing platinum resistance, while the addition of IGF-1 R inhibitor reversed the effects of adipocytes on proliferation, apoptosis, and drug resistance of OvCa cells. Treatment with different concentrations of Ojeok-san (OJS) inhibited the adipocyte-induced platinum resistance in OvCa cells by suppressing IGF1. The combined treatment of OJS and cisplatin significantly inhibited tumour growth in vivo with good mouse tolerance.

CONCLUSION

In summary, OJS inhibited OvCa proliferation and platinum resistance by suppressing adipocyte paracrine IGF1 secretion.

Targeting G-quadruplex motifs interferes with differentiation of adipose-derived mesenchymal stem cells

BACKGROUND

G-quadruplex (G4) motifs are nucleic acid secondary structures observed in mammalian genomes and transcriptomes able to regulate various cellular processes. Several small molecules have been developed so far to modulate G4 stability, frequently associated with anticancer activity. However, how G4 structures are regulated over homeostatic conditions is mostly unexplored. Here, we used human adipose-derived mesenchymal stem cells (ASCs) to address the role of G4 motifs during adipogenic differentiation.

METHODS

Adipocyte differentiation of ASCs was investigated in the presence or absence of a well-known G4 ligand, Braco-19. Cell viability was determined by sulforhodamine B assay. Cell dimension and granularity, DNA G4 motifs and cell cycle were detected by flow cytometry. Lipid droplet accumulation was assessed by Oil Red O staining. Cell senescence was evaluated by β-galactosidase staining. Gene expression was measured by qPCR. Protein release in the extracellular medium was quantified by ELISA.

RESULTS

Braco-19 used at non-cytotoxic concentrations induced morphological changes in mature adipocytes partially restoring an undifferentiated-like status. Braco-19 reduced lipid vacuolization and PPARG, AP2, LEP and TNFA mRNA levels in terminally differentiated cells. No effect was observed in cell senescence, fibrotic markers, IL-6 and IL-8 production, while the secretion of VEGF was dose-dependently reduced. Interestingly, G4 structures were increased in differentiated adipocytes compared to their precursors. Braco-19 treatment reduced G4 content in mature adipocytes.

CONCLUSIONS

Our data highlight a new role of G4 motifs as genomic structural elements related to human ASC differentiation into mature adipocytes, with potential implications in physio-pathological processes.

Current perspectives on cell-assisted lipotransfer for breast cancer patients after radiotherapy

BACKGROUND

Cell-assisted lipotransfer (CAL), a technique of autologous adipose transplantation enriched with adipose-derived stem cells (ADSCs), has the potential to improve cosmetic outcomes at irradiated sites. However, many concerns have been raised about the possibility of ADSCs increasing oncological risk in cancer patients. With the increasing demand for CAL reconstruction, there is an urgent need to determine whether CAL treatment could compromise oncological safety after radiotherapy, as well as to evaluate its efficacy in guiding clinical decisions.

METHODS

A PRISMA-compliant systematic review of the safety and efficacy of CAL in breast cancer patients after radiotherapy was conducted. The PubMed, Ovid, Cochrane Library, and ClinicalTrials.gov databases were comprehensively searched from inception to 31 December 2021.

RESULTS

The search initially yielded 1185 unique studies. Ultimately, seven studies were eligible. Based on the limited outcome evidence, CAL did not increase recurrence risk in breast cancer patients but presented aesthetic improvement and higher volumetric persistence in a long-term follow-up. Although breast reconstruction with CAL also had oncological safety after radiotherapy, these patients needed more adipose tissue and had relatively lower fat graft retention than the non-irradiated patients (P < 0.05).

CONCLUSIONS

CAL has oncological safety and does not increase recurrence risk in irradiated patients. Since CAL doubles the amount of adipose required without significantly improving volumetric persistence, clinical decisions for irradiated patients should be made more cautiously to account for the potential costs and aesthetic outcomes. There is limited evidence at present; thus, higher-quality, evidence-based studies are required to establish a consensus on breast reconstruction with CAL after radiotherapy.

The Role of Mesenchymal Stem Cells in Modulating the Breast Cancer Microenvironment

The role of mesenchymal stem cells (MSCs) in the breast tumor microenvironment (TME) is significant and multifaceted. MSCs are recruited to breast tumor sites through molecular signals released by tumor sites. Once in the TME, MSCs undergo polarization and interact with various cell populations, including immune cells, cancer-associated fibroblasts (CAFs), cancer stem cells (CSCs), and breast cancer cells. In most cases, MSCs play roles in breast cancer therapeutic resistance, but there is also evidence that indicates their abilities to sensitize cancer cells to chemotherapy and radiotherapy. MSCs possess inherent regenerative and homing properties, making them attractive candidates for cell-based therapies. Therefore, MSCs can be engineered to express therapeutic molecules or deliver anti-cancer agents directly to tumor sites. Unraveling the intricate relationship between MSCs and the breast TME has the potential to uncover novel therapeutic targets and advance our understanding of breast cancer biology.

Altered Adipokine Expression in Tumor Microenvironment Promotes Development of Triple Negative Breast Cancer

Obesity is a remarkably important factor for breast carcinogenesis and aggressiveness. The implication of increased BMI in triple negative breast cancer (TNBC) development is also well established. A malignancy-promoting role of the adipose tissue has been supposed, where the adipocytes that constitute the majority of stromal cells release pro-inflammatory cytokines and growth factors. Alterations in adipokines and their receptors play significant roles in breast cancer initiation, progression, metastasis, and drug response. Classic adipokines, such as leptin, adiponectin, and resistin, have been extensively studied in breast cancer and connected with breast cancer risk and progression. Notably, new molecules are constantly being discovered and the list is continuously growing. Additionally, substantial progress has been made concerning their differential expression in association with clinical and pathological parameters of tumors and the prognostic and predictive value of their dysregulation in breast cancer carcinogenesis. However, evidence regarding the mechanisms by which adipose tissue is involved in the development of TNBC is lacking. In the present article we comment on current data on the suggested involvement of these mediators in breast cancer development and progression, with particular emphasis on TNBC, to draw attention to the design of novel targeted therapies and biomarkers.

Adipose Tissue-Derived Mesenchymal Stromal/Stem Cells, Obesity and the Tumor Microenvironment of Breast Cancer

Simple Summary

Adipose tissue is the major microenvironment of breast cancer. Adipose tissue-derived mesenchymal stromal/stem cells (ASCs/MSCs) are key players in adipose tissue. ASCs/MSCs, particularly in the obese state, are critical in remodeling the tumor microenvironment and promoting breast cancer progression. In this review, we have addressed the impact of obesity on ASCs/MSCs, summarized the crosstalk between ASCs/MSCs and breast cancer cells, discussed related molecular mechanisms, and highlighted related research perspectives.

Abstract

Breast cancer is the most frequently diagnosed cancer and a common cause of cancer-related death in women. It is well recognized that obesity is associated with an enhanced risk of more aggressive breast cancer as well as reduced patient survival. Adipose tissue is the major microenvironment of breast cancer. Obesity changes the composition, structure, and function of adipose tissue, which is associated with inflammation and metabolic dysfunction. Interestingly, adipose tissue is rich in ASCs/MSCs, and obesity alters the properties and functions of these cells. As a key component of the mammary stroma, ASCs play essential roles in the breast cancer microenvironment. The crosstalk between ASCs and breast cancer cells is multilateral and can occur both directly through cell–cell contact and indirectly via the secretome released by ASC/MSC, which is considered to be the main effector of their supportive, angiogenic, and immunomodulatory functions. In this narrative review, we aim to address the impact of obesity on ASCs/MSCs, summarize the current knowledge regarding the potential pathological roles of ASCs/MSCs in the development of breast cancer, discuss related molecular mechanisms, underline the possible clinical significance, and highlight related research perspectives. In particular, we underscore the roles of ASCs/MSCs in breast cancer cell progression, including proliferation and survival, angiogenesis, migration and invasion, the epithelial–mesenchymal transition, cancer stem cell development, immune evasion, therapy resistance, and the potential impact of breast cancer cells on ASCS/MSCs by educating them to become cancer-associated fibroblasts. We conclude that ASCs/MSCs, especially obese ASCs/MSCs, may be key players in the breast cancer microenvironment. Targeting these cells may provide a new path of effective breast cancer treatment.

Tumor-targeted miRNA nanomedicine for overcoming challenges in immunity and therapeutic resistance

miRNA are critical messengers in the tumor microenvironment (TME) that influence various processes leading to immune suppression, tumor progression, metastasis and resistance. Strategies to modulate miRNAs in the TME have important implications in overcoming these challenges. However, miR delivery to specific cells in the TME has been challenging. This review discusses nanomedicine strategies to achieve cell-specific delivery of miRNAs. The key goal of delivery is to activate the tumor immune landscape as well as to prevent chemotherapy resistance. Specifically, the use of hyaluronic acid-based nanoparticle miRNA delivery to the TME is discussed. The discussion is focused on miRNA-125b for reprogramming tumor-associated macrophages to overcome immunosuppression and miRNA-let-7b to overcome resistance to anticancer chemotherapeutics because both these miRNAs have been extensively evaluated for delivery with hyaluronic acid-based delivery systems.

Help or hindrance: The obesity paradox in cancer treatment response

Obesity is a rising epidemic, the influence of which on cancer development, progression as well as its impact on current standard of care cancer treatments is profound with many facets. Obesity is emerging as a modulating factor in many cancer therapies, such as chemotherapy, radiotherapy, immunotherapy and combination therapies. It has been reported to diminish the efficacy of some treatments but has also been alluded to being protective in terms of reduced treatment toxicities, thus the evolution of the obesity paradox. The obese tumour microenvironment influences treatment response through modulation of a series of aspects, including altered adipocyte secretome, angiogenesis, hypoxia, fibrosis, free fatty acid uptake as well as a modulated immune landscape. However, the influence of these underlying mechanisms on cancer treatment response and the biological action of adipose tissue is still largely unknown. Elucidation of these facets may lead to the enhanced efficacy of current treatment options or the identification of novel methods to combat cancer in the obese tumour microenvironment.

Adipocyte and lipid metabolism in cancer drug resistance

Development of novel and effective therapeutics for treating various cancers is probably the most congested and challenging enterprise of pharmaceutical companies. Diverse drugs targeting malignant and nonmalignant cells receive clinical approval each year from the FDA. Targeting cancer cells and nonmalignant cells unavoidably changes the tumor microenvironment, and cellular and molecular components relentlessly alter in response to drugs. Cancer cells often reprogram their metabolic pathways to adapt to environmental challenges and facilitate survival, proliferation, and metastasis. While cancer cells' dependence on glycolysis for energy production is well studied, the roles of adipocytes and lipid metabolic reprogramming in supporting cancer growth, metastasis, and drug responses are less understood. This Review focuses on emerging mechanisms involving adipocytes and lipid metabolism in altering the response to cancer treatment. In particular, we discuss mechanisms underlying cancer-associated adipocytes and lipid metabolic reprogramming in cancer drug resistance.

Adaptive EGF expression sensitizes pancreatic cancer cells to ionizing radiation through activation of the cyclin D1/P53/PARP pathway

It is well-known that the activation status of the P53, signal transducer and activator of transcription (Stat)3 and nuclear factor (NF)‑κB signaling pathways determines the radiosensitivity of cancer cells. However, the function of these pathways in radiosensitive vs radioresistant cancer cells remains elusive. The present study demonstrated that adaptive expression of epidermal growth factor (EGF) following exposure to ionizing radiation (IR) may induce radiosensitization of pancreatic cancer (PC) cells through induction of the cyclin D1/P53/poly(ADP‑ribose) polymerase pathway. By contrast, adaptively expressed interleukin (IL)‑6 and insulin‑like growth factor (IGF)‑1 may promote radioresistance of PC cells, likely through activation of the Stat3 and NF‑κB pathways. In addition, cyclin D1 and survivin, which are specifically expressed in the G1/S and G2/M phase of the cell cycle, respectively, are mutually exclusive in radiosensitive and radioresistant PC cells, while Bcl‑2 and Bcl‑xL expression does not differ between radiosensitive and radioresistant PC cells. Therefore, adaptively expressed EGF and IL‑6/IGF‑1 may alter these pathways to promote the radiosensitivity of PC cancers. The findings of the present study highlight potential makers for the evaluation of radiosensitivity and enable the development of effective regimens for cancer radiotherapy.

Radiation Sensitivity of Adipose-Derived Stem Cells Isolated from Breast Tissue

Within their niche, adipose-derived stem cells (ADSCs) are essential for homeostasis as well as for regeneration. Therefore, the interest of physicians is to use ADSCs as a tool for radiation oncology and regenerative medicine. To investigate related risks, this study analyses the radiation response of adult stem cells isolated from the adipose tissue of the female breast. To avoid donor-specific effects, ADSCs isolated from breast reduction mammoplasties of 10 donors were pooled and used for the radiobiological analysis. The clonogenic survival fraction assay was used to classify the radiation sensitivity in comparison to a more radiation-sensitive (ZR-75-1), moderately sensitive (MCF-7), and resistant (MCF10A) cell lines. Afterwards, cytotoxicity and genotoxicity of irradiation on ADSCs were investigated. On the basis of clonogenic cell survival rates of ADSCs after irradiation, we assign ADSCs an intermediate radiation sensitivity. Furthermore, a high repair capacity of double-strand breaks is related to an altered cell cycle arrest and increased expression of cyclin-dependent kinase (CDK) inhibitor p21. ADSCs isolated from breast tissue exhibit intermediate radiation sensitivity, caused by functional repair mechanisms. Therefore, we propose ADSCs to be a promising tool in radiation oncology.

Bone marrow-derived mesenchymal stromal cells promote colorectal cancer cell death under low-dose irradiation

BACKGROUND

Radiotherapy remains one of the cornerstones to improve the outcome of colorectal cancer (CRC) patients. Radiotherapy of the CRC not only help to destroy cancer cells but also remodel the tumour microenvironment by enhancing tumour-specific tropism of bone marrow-derived mesenchymal stromal cell (BM-MSC) from the peripheral circulation. However, the role of local MSCs and recruited BM-MSC under radiation were not well defined. Indeed, the functions of BM-MSC without irradiation intervention remained controversial in tumour progression: BM-MSC was previously shown to modulate the immune function of major immune cells, resulting in an impaired immunological sensitivity and to induce an increased risk of tumour recurrence. In contrast, it could also secrete various cytokines and possess anticancer effect.

METHODS

Three co-cultivation modules, 3D culture modules, and cancer organoids were established. The induction of cytokines secretion in hBM-MSCs after irradiation was analysed by ELISA array and flow cytometry. AutoMac separator was used to separate hBM-MSC and CRC automatically. Cells from the co-cultured group and the control group were then irradiated by UV-C lamp and X-ray. Proliferation assay and viability assay were performed.

RESULTS

In this study, we show that BM-MSCs can induce the EMT progression of CRC cells in vitro. When irradiated with low doses of ultraviolet radiation and X-rays, BM-MSCs show an anti-tumour effect by secreting certain cytokine (TNF-α, IFN-γ) that lead to the inhibition of proliferation and induction of apoptosis of CRC cells. This was further verified in a 3D culture model of a CRC cell in vitro. Furthermore, irradiation on the co-culture system induced the cleavage of caspase3, and attenuated the phosphorylation of phosphatidylinositol 3-kinase (PI3K)/AKT and extracellular signal-regulated kinase in cancer cells. The signal pathways above might contribute to the cancer cell death.

CONCLUSIONS

Taken together, we show that BM-MSC can potentially promote the effect of radiotherapy in CRC.

Aiming for the Insulin-like Growth Factor-1 system in breast cancer therapeutics

Despite the major discoveries occurred in oncology the recent years, breast malignancies remain one of the most common causes of cancer-related deaths for women in developed countries. Development of HER2-targeting drugs has been considered a breakthrough in anti-cancer approaches and alluded to the potential of targeting growth factors in breast cancer (BrCa) therapeutics. More than twenty-five years have passed since the Insulin-like Growth Factor-1 (IGF-1) system was initially recognized as a potential target candidate in BrCa therapy. To date, a growing body of studies have implicated the IGF-1 signaling with the BrCa biology. Despite the promising experimental evidence, the impression from clinical trials is rather disappointing. Several reasons may account for this and the last word regarding the efficacy of this system as a target candidate in BrCa therapeutics is probably not written yet. Herein, we provide the theoretical basis, as well as, a comprehensive overview of the current literature, regarding the different strategies targeting the various components of the IGF-1/IGF-1R axis in several pathophysiological aspects of BrCa, including the tumor micro-environment and cancer stemness. In addition, we review the rationale for targeting the IGF-1 system in the different BrCa molecular subtypes and in treatment resistant breast tumors with a focus on both the molecular mechanisms and on the clinical perspectives of such approaches in specific population subgroups. We also discuss the future challenges, as well as, the development of novel molecules and strategies targeting the system and suggest potential improvements in the field.

Promoting effects of adipose-derived stem cells on breast cancer cells are reversed by radiation therapy

Partial breast irradiation of early breast cancer patients after lumpectomy and the use of endogenous adipose tissue (AT) for breast reconstruction are promising applications to reduce the side effects of breast cancer therapy. This study tries to investigate the possible risks associated with these therapeutic approaches. It also examines the influence of adipose derived stem cells (ADSCs) as part of the breast cancer microenvironment, and endogenous AT on breast cancer cells following radiation therapy. ADSCs, isolated from human reduction mammoplasties of healthy female donors, exhibited multilineage capacity and specific surface markers. The promoting effects of ADSCs on the growth and survival fraction of breast cancer cells were reversed by treatment with high (8 Gy) or medium (2 Gy) radiation doses. In addition, a suppressing influence on breast cancer growth could be detected by co-culturing with irradiated ADSCs (8 Gy). Furthermore the clonogenic survival of unirradiated tumor cells was reduced by medium of irradiated ADSCs. In conclusion, radiation therapy changed the interactions of ADSCs and breast cancer cells. On the basis of our work, the importance of further studies to exclude potential risks of ADSCs in regenerative applications and radiotherapy has been emphasized.

Radio-resistant mesenchymal stem cells: mechanisms of resistance and potential implications for the clinic

Mesenchymal stem cells (MSCs) comprise a heterogeneous population of multipotent stromal cells and can be isolated from various tissues and organs. Due to their regenerative potential, they have been subject to intense research efforts, and they may provide an efficient means for treating radiation-induced tissue damage. MSCs are relatively resistant to ionizing radiation and retain their stem cell characteristics even after high radiation doses. The underlying mechanisms for the observed MSC radioresistance have been extensively studied and may involve efficient DNA damage recognition, double strand break repair and evasion of apoptosis. Here, we present a concise review of the published scientific data on the radiobiological features of MSCs. The involvement of different DNA damage recognition and repair pathways in the creation of a radioresistant MSC phenotype is outlined, and the roles of apoptosis, senescence and autophagy regarding the reported radioresistance are summarized. Finally, potential influences of the radioresistant MSCs for the clinic are discussed with respect to the repair and radioprotection of irradiated tissues.