Advances in natural killer cell therapies for breast cancer.

Breast cancer (BC) is the most common cause of cancer death in women. According to the American Cancer Society's yearly cancer statistics, BC constituted almost 15% of all the newly diagnosed cancer cases in 2022 for both sexes. Metastatic disease occurs in 30% of patients with BC. The currently available treatments fail to cure metastatic BC, and the average survival time for patients with metastatic BC is approximately 2 years. Developing a treatment method that terminates cancer stem cells without harming healthy cells is the primary objective of novel therapeutics. Adoptive cell therapy is a branch of cancer immunotherapy that utilizes the immune cells to attack cancer cells. Natural killer (NK) cells are an essential component of innate immunity and are critical in destroying tumor cells without prior stimulation with antigens. With the advent of chimeric antigen receptors (CARs), the autologous or allogeneic use of NK/CAR-NK cell therapy has raised new hopes for treating patients with cancer. Here, we describe recent developments in NK and CAR-NK cell immunotherapy, including the biology and function of NK cells, clinical trials, different sources of NK cells and their future perspectives on BC.

Inhibitory Effect of Mesenchymal Stem Cell Co-Culture on Erythroid Differentiation of K562 Cells Compared to The Control Group.

OBJECTIVE: Bone marrow mesenchymal stem cells (BMMSCs) reside in the bone marrow and control the process of hematopoiesis. They are an excellent instrument for regenerative treatment and co-culture with hematopoietic stem cells (HSCs). MATERIALS AND METHODS: In this experimental study, K562 cell lines were either treated with butyric acid and co-cultured with MSCs, or cultivated in a conditioned medium from MSCs plus butyric acid for erythroid differentiation. We used the trypan blue dye exclusion assay to determine cell counts and viability in each group. For each group, we separately assessed erythroid differentiation of the K562 cell line with Giemsa stain under light microscopy, expression of specific markers of erythroid cells by flowcytometry, and erythroidspecific gene expressions by real-time polymerase chain reaction (RT-PCR). RESULTS: There was enhandced erythroid differentiation of K562 cells with butyric acid compared to the K562 cell line co-cultured with MSCs and butyric acid. Erythroid differentiation of the K562 cell line cultivated in conditioned medium with butyric acid was higher than the K562 cell line co-cultured with MSCs and butyric acid, but less than K562 cell line treated with butyric acid only. CONCLUSION: Our results showed that MSCs significantly suppressed erythropoiesis. Therefore, MSCs would not be a suitable optimal treatment strategy for patients with erythroid leukemia.

The Effect of Bone Marrow Mesenchymal Stem Cells on Vitamin D3 Induced Monocytic Differentiation of U937 Cells.

PURPOSE: Mesenchymal stem cells (MSCs) are key components of the hematopoietic stem cells (HSCs) niche. They control the process of hematopoiesis by secreting regulatory cytokines, growth factors and expression of important cell adhesion molecules for cell-tocell interactions. In this research, we have investigated the effect of bone marrow derived MSCs on monocytic differentiation of U937 cells line. METHODS: U937 cells were cultured in both direct co-culture with MSCs and MSCs conditioned medium (C.M) driven. This study used 1,25-dihydroxyvitamin D3(VitD3) as inductor of monocytic differentiation and U937 cells treated with VitD3 morphology was examined by Wright Giemsa staining. CD14 monocytic differentiation marker was measured by flow cytometry and monocytic gene expression was assessed by real time polymerase chain reaction (RT PCR). RESULTS: The results of flow cytometric analysis showed that CD14 expression of U937 increased. The higher effect of MSCs co-culture on CD14 expression in U937 cells was observed, compared to the conditioned medium. Among ten monocytic related genes which were screened that was observed increase in 5 genes in which CXCR4 and CSF2RA showed significant increase. CONCLUSION: The results obtained show that MSCs have supportive effect on the monocytic differentiation of U937 cells. However, a distinct mechanism of that remains unclear.

The Impact of Mesenchymal Stem Cells on Differentiation of Hematopoietic Stem Cells.

Bone marrow microenvironment contains cellular and acellular compartments. The cellular compartment includes hematopoietic stem cells, mesenchymal stem cells and some other stromal cell types, while the acellular compartment is composed of scaffold proteins known as the extra cellular matrix. Direct cell-cell contact as well as cytokines secreted by mesenchymal stem cells during coculture of hematopoietic stem cells and mesenchymal stem cells play a critical role in hematopoiesis, and determines the fate of hematopoietic stem cells. Several studies have demonstrated the impact of mesenchymal stem cells on self-renewal, expansion, proliferation and differentiation of hematopoietic stem cells in vitro, which have shown different and contradictory results. In this paper, we will investigate the effect of mesenchymal stem cells on differentiation of hematopoietic stem cells in vitro.

The Effect of Hypoxia on Mesenchymal Stem Cell Biology.

Although physiological and pathological role of hypoxia have been appreciated in mammalians for decades however the cellular biology of hypoxia more clarified in the past 20 years. Discovery of the transcription factor hypoxia-inducible factor (HIF)-1, in the 1990s opened a new window to investigate the mechanisms behind hypoxia. In different cellular contexts HIF-1 activation show variable results by impacting various aspects of cell biology such as cell cycle, apoptosis, differentiation and etc. Mesenchymal stem cells (MSC) are unique cells which take important role in tissue regeneration. They are characterized by self-renewal capacity, multilineage potential, and immunosuppressive property. Like so many kind of cells, hypoxia induces different responses in MSCs by HIF- 1 activation. The activation of this molecule changes the growth, multiplication, differentiation and gene expression profile of MSCs in their niche by a complex of signals. This article briefly discusses the most important effects of hypoxia in growth kinetics, signalling pathways, cytokine secretion profile and expression of chemokine receptors in different conditions.