Adipose-Derived Stem Cells Can Replace Fibroblasts as Cell Control for Anti-Tumor Screening Assay.

Anti-tumor activity screening is a typical process used in anti-tumor drug discovery. The ideal anti-tumor drug candidates are extracts or compounds that can inhibit the proliferation of cancer cells via apoptosis, while exerting minimal effects on normal somatic cells. For a long time, fibroblasts were used as normal cells for all anti-tumor screening assays. However, the fibroblasts exhibited several limitations as cell controls for anti-tumor screening. This study aimed to compare the usage of dermal fibroblasts (DFs) and adipose-derived stem cells (ADSCs) as normal cell controls in anti-tumor screening protocols. The DFs and ADSCs were prepared per the published protocols. The IC50 values of doxorubicin on hepatocellular carcinoma cells HepG2, breast cancer cells MCF-7, DFs and ADSCs were determined via the Alamar blue assay. The side effect indexes (SEIs) were calculated as the ratio of IC50 values of drugs on cancer cells and IC50 values of drugs on DFs, and on ADSCs. The stability of the anti-tumor assay was investigated when carried out on DFs and ADSCs from different passages. The results showed that the IC50 values, as well as SEI values, were not significantly different between using DFs or ADSCs as normal cell controls when DFs and ADSCs were at passage 3. However, for DFs at passage 6 to 12, the IC50 values of doxorubicin were significantly different between DFs and ADSCs. The IC50 values of doxorubicin on DFs were strongly reduced due to the senescence of DFs, while the values were more constant in ADSCs. The SEI values of doxorubicin on DFs, compared to HepG2 and MCF-7 cells, were also changed during passage 3 to 12 of the DFs. However, these values were only slightly changed for ADSCs from the 3rd to 12th passages. ADSCs can replace DFs as a normal cell control for anti-tumor activity screening.

Hopea odorata Extract Can Efficiently Kill Breast Cancer Cells and Cancer Stem-Like Cells in Three-Dimensional Culture More Than in Monolayer Cell Culture.

INTRODUCTION: The breast cancer cells with CD44+CD24- phenotype are known to play an important role in tumorigenesis, drug resistance, and cancer recurrence. Breast cancer cells with CD44+CD24- phenotype are cultured in three-dimensional (3D) stereotype showing the recapitulation of tumors in vivo such as cell differentiation, heterogeneity, and microenvironment. Using this 3D model in anti-cancer compound research results in a more accurate reflection than conventional monolayer cell culture. This study aimed to identify the antitumor activity of Hopea odorata methanol extract (HO-MeOH-E) on breast cancer cells and cancer stem-like cells in both models of three-dimensional culture (3D) and monolayer cell culture (2D). METHODS: HO-MeOH-E was produced from Hopea odorata plant. The VN9 breast cancer cells (VN9) were collected and expanded from the previous study. The breast cancer stem-like cells (VN9CSC) were sorted from the VN9 based on phenotype CD44+CD24-. Both VN9 and VN9CSC were used to culture in monolayer culture (2D) and organoids (3D) before they were used to treat with HO-MeOH-E. Two other anticancer drugs, doxorubicin and tirapazamine, were used as references. The antitumor activities of extracts and drugs were determined via two assays: antiproliferation using the Alamar blue assay and cell cycle assay. RESULTS: The results showed that HO-MeOH-E was sensitive to both VN9 and VN9CSC in 3D more than 2D culture (IC50 on 3D organoids 144.8 ± 2.172 µg/mL and on 2D 340.2 ± 17.01 µg/mL for VN9CSC (p < 0.001); IC50 on 3D organoids 2055 ± 82.2 µg/mL and on 2D 430.6 ± 8.612 µg/mL for VN9 (p < 0.0001), respectively). HO-MeOH-E inhibits VN9CSC proliferation by blocking S phase and increasing the populations of apoptotic cells; this is consensus to the effect of tirapazamine (TPZ) which is used in hypoxia-activated chemotherapy. CONCLUSION: Taken these results, HO-MeOH-E has the potential effect in hypoxia-activated chemotherapy specifically on breast cancer stem-like cells with CD44+CD24- phenotype.

Comparative Clinical Observation of Arthroscopic Microfracture in the Presence and Absence of a Stromal Vascular Fraction Injection for Osteoarthritis.

Osteoarthritis (OA) is a degenerative cartilage disease that is characterized by a local inflammatory reaction. Consequently, many studies have been performed to identify suitable prevention and treatment interventions. In recent years, both arthroscopic microfracture (AM) and stem cell therapy have been used clinically to treat OA. This study aimed to evaluate the clinical effects of AM in the presence and absence of a stromal vascular fraction (SVF) injection in the management of patients with OA. Thirty patients with grade 2 or 3 (Lawrence scale) OA of the knee participated in this study. Placebo group patients (n = 15) received AM alone; treatment group patients (n = 15) received AM and an adipose tissue-derived SVF injection. The SVF was suspended in platelet-rich plasma (PRP) before injection into the joint. Patient groups were monitored and scored with the Western Ontario and McMaster Universities Arthritis Index (WOMAC), Lysholm, Visual Analog Pain Scale (VAS), and modified Outerbridge classifications before treatment and at 6, 12, and 18 months post-treatment. Bone marrow edema was also assessed at these time points. Patients were evaluated for knee activity (joint motion amplitude) and adverse effects relating to surgery and stem cell injection. Treatment efficacy was significantly different between placebo and treatment groups. All treatment group patients had significantly reduced pain and WOMAC scores, and increased Lysholm and VAS scores compared with the placebo group. These findings suggest that the SVF/PRP injection efficiently improved OA for 18 months after treatment. This study will be continuously monitored for additional 24 months. Stem Cells Translational Medicine 2017;6:187-195.

Targeting breast cancer stem cells by dendritic cell vaccination in humanized mice with breast tumor: preliminary results.

BACKGROUND: Breast cancer (BC) is one of the leading cancers in women. Recent progress has enabled BC to be cured with high efficiency. However, late detection or metastatic disease often renders the disease untreatable. Additionally, relapse is the main cause of death in BC patients. Breast cancer stem cells (BCSCs) are considered to cause the development of BC and are thought to be responsible for metastasis and relapse. This study aimed to target BCSCs using dendritic cells (DCs) to treat tumor-bearing humanized mice models. MATERIALS AND METHODS: NOD/SCID mice were used to produce the humanized mice by transplantation of human hematopoietic stem cells. Human BCSCs were injected into the mammary fat pad to produce BC humanized mice. Both hematopoietic stem cells and DCs were isolated from the human umbilical cord blood, and immature DCs were produced from cultured mononuclear cells. DCs were matured by BCSC-derived antigen incubation for 48 hours. Mature DCs were vaccinated to BC humanized mice with a dose of 10(6) cells/mice, and the survival percentage was monitored in both treated and untreated groups. RESULTS: The results showed that DC vaccination could target BCSCs and reduce the tumor size and prolong survival. CONCLUSION: These results suggested that targeting BCSCs with DCs is a promising therapy for BC.

Low concentrations of 5-aza-2'-deoxycytidine induce breast cancer stem cell differentiation by triggering tumor suppressor gene expression.

BACKGROUND: Breast cancer stem cells (BCSCs) are considered the cause of tumor growth, multidrug resistance, metastasis, and recurrence. Therefore, differentiation therapy to reduce self-renewal of BCSCs is a promising approach. We have examined the effects of 5-aza-2'-deoxycytidine (DAC) on BCSC differentiation. MATERIALS AND METHODS: BCSCs were treated with a range of DAC concentrations from 0.625 to 100 µM. The differentiation status of DAC-treated BCSCs was graded by changes in cell proliferation, CD44(+)CD24(-) phenotype, expression of tumor suppressor genes, including BRCA1, BRCA2, p15, p16, p53, and PTEN, and antitumor drug resistance. RESULTS: DAC treatment caused significant BCSC differentiation. BCSCs showed a 15%-23% reduction in proliferation capacity, 3.0%-21.3% decrease in the expression of BCSC marker CD44(+)/CD24(-), activation of p53 expression, and increased p15, p16, BRCA1, and BRCA2 expression. Concentrations of DAC ranging from 0.625 to 40 µM efficiently induce cell cycle arrest in S-phase. ABCG2, highly expressed in BCSCs, also decreased with DAC exposure. Of particular note, drug-sensitivity of BCSCs to doxorubicin, verapamil, and tamoxifen also increased 1.5-, 2.0-, and 3.7-fold, respectively, after pretreatment with DAC. CONCLUSION: DAC reduced breast cancer cell survival and induced differentiation through reexpression of tumor suppressor genes. These results indicate the potential of DAC in targeting specific chemotherapy-resistant cells within a tumor.

Vitamin C stimulates human gingival stem cell proliferation and expression of pluripotent markers.

Gingival stem cells (GSCs) are a novel source of mesenchymal stem cells (MSCs) that are easily accessed from the oral cavity. GSCs were considered valuable autograft MSCs with particular characteristics. However, the limitation in the number of available GSCs remains an obstacle. Therefore, this study aimed to stimulate GSC proliferation by ascorbic acid (AA) and determined the effects of AA on GSC pluripotent potential-related gene expression. GSCs were isolated from gum tissue by explant culture and continuously subcultured before analysis of stemness and effects of AA on pluripotent-related gene expression. GSCs cultured with various concentrations of AA showed increased proliferation in a dose-dependent manner. AA-treated GSCs showed significantly higher expression of SSEA-3, Sox-2, Oct-3/4, Nanog, and TRA-1-60 compared with control cells. More importantly, GSCs also maintained their stemness with MSC phenotypes and failed to cause tumors in nude athymic mice. Our results show that AA is a suitable factor to stimulate GSC proliferation.

Activated platelet-rich plasma improves adipose-derived stem cell transplantation efficiency in injured articular cartilage.

INTRODUCTION: Adipose-derived stem cells (ADSCs) have been isolated, expanded, and applied in the treatment of many diseases. ADSCs have also been used to treat injured articular cartilage. However, there is controversy regarding the treatment efficiency. We considered that ADSC transplantation with activated platelet-rich plasma (PRP) may improve injured articular cartilage compared with that of ADSC transplantation alone. In this study, we determined the role of PRP in ADSC transplantation to improve the treatment efficiency. METHODS: ADSCs were isolated and expanded from human adipose tissue. PRP was collected and activated from human peripheral blood. The effects of PRP were evaluated in vitro and in ADSC transplantation in vivo. In vitro, the effects of PRP on ADSC proliferation, differentiation into chondrogenic cells, and inhibition of angiogenic factors were investigated at three concentrations of PRP (10%, 15% and 20%). In vivo, ADSCs pretreated with or without PRP were transplanted into murine models of injured articular cartilage. RESULTS: PRP promoted ADSC proliferation and differentiation into chondrogenic cells that strongly expressed collagen II, Sox9 and aggrecan. Moreover, PRP inhibited expression of the angiogenic factor vascular endothelial growth factor. As a result, PRP-pretreated ADSCs improved healing of injured articular cartilage in murine models compared with that of untreated ADSCs. CONCLUSION: Pretreatment of ADSCs with PRP is a simple method to efficiently apply ADSCs in cartilage regeneration. This study provides an important step toward the use of autologous ADSCs in the treatment of injured articular cartilage.

Suppression of human breast tumors in NOD/SCID mice by CD44 shRNA gene therapy combined with doxorubicin treatment.

BACKGROUND: Breast cancer stem cells with a CD44(+)CD24(-) phenotype are the origin of breast tumors. Strong CD44 expression in this population indicates its important role in maintaining the stem cell phenotype. Previous studies show that CD44 down-regulation causes CD44(+)CD24(-) breast cancer stem cells to differentiate into non-stem cells that are sensitive to antitumor drugs and lose many characteristics of the original cells. In this study, we determined tumor suppression in non-obese severe combined immunodeficiency mice using CD44 shRNA therapy combined with doxorubicin treatment. METHODS: Tumor-bearing non-obese severe combined immunodeficiency mice were established by injection of CD44(+)CD24(-) cells. To track CD44(+)CD24(-) cells, green fluorescence protein was stably transduced using a lentiviral vector prior to injection into mice. The amount of CD44 shRNA lentiviral vector used for transduction was based on CD44 down-regulation by in vitro CD44 shRNA transduction. Mice were treated with direct injection of CD44 shRNA lentiviral vector into tumors followed by doxorubicin administration after 48 hours. The effect was evaluated by changes in the size and weight of tumors compared with that of the control. RESULTS: The combination of CD44 down-regulation and doxorubicin strongly suppressed tumor growth with significant differences in tumor sizes and weights compared with that of CD44 down-regulation or doxorubicin treatment alone. In the combination of CD44 down-regulation and doxorubicin group, the tumor weight was significantly decreased by 4.38-fold compared with that of the control group. CONCLUSION: These results support a new strategy for breast cancer treatment by combining gene therapy with chemotherapy.