Synthesis of a celastrol derivative as a cancer stem cell inhibitor through regulation of the STAT3 pathway for treatment of ovarian cancer.

Accumulating evidence suggests that the root of drug chemoresistance in ovarian cancer is tightly associated with subpopulations of cancer stem cells (CSCs), whose activation is largely associated with signal transducer and activator of transcription 3 (STAT3) signaling. Recently, celastrol has shown a significant anti-cancer effect on ovarian cancer, but its clinical translation is very challenging due to its oral bioavailability and high organ toxicity. In this study, a celastrol derivative (Cel-N) was synthesized to augment the overall efficacy, and its underlying mechanisms were also explored. Different ovarian cancer cells, SKOV3 and A2780, were used to evaluate and compare the anticancer effects. Cel-N displayed potent activities against all the tested ovarian cancer cells, with the lowest IC50 value of 0.14-0.25 µM. Further studies showed that Cel-N effectively suppressed the colony formation and sphere formation ability, decreased the percentage of CD44+CD24- and ALDH+ cells, and induced ROS production. Furthermore, western blot analysis indicated that Cel-N significantly inhibited both Tyr705 and Ser727 phosphorylation and reduced the protein expression of STAT3. In addition, Cel-N could dramatically induce apoptosis and cell cycle arrest, and inhibit migration and invasion. Importantly, Cel-N showed a potent antitumor efficacy with no or limited systemic toxicity in mice xenograft models. The anticancer effect of Cel-N is stronger than celastrol. Cel-N attenuates cancer cell stemness, inhibits the STAT3 pathway, and exerts anti-ovarian cancer effects in cell and mouse models. Our data support that Cel-N is a potent drug candidate for ovarian cancer.

Discovery of semisynthetic celastrol derivatives exhibiting potent anti-ovarian cancer stem cell activity and STAT3 inhibition.

The hallmark of ovarian cancer is its high mortality rate attributed to the existence of cancer stem cells (CSCs) subpopulations which result in therapy recurrence and metastasis. A series of C-29-substituted and/or different A/B ring of celastrol derivatives were synthesized and displayed potential inhibition against ovarian cancer cells SKOV3, A2780 and OVCAR3. Among them, compound 6c exhibited the most potent anti-proliferative activity and selectivity, gave superior anti-CSC effects through inhibition of the sphere formation and downregulation of the percentage of CD44+CD24- and ALDH+ cells. Further mechanism research demonstrated that compound 6c could attenuate the expression of STAT3 and p-STAT3. The results suggested that the inhibition of celastrol derivative 6c on ovarian cancer cells may be related to resistance to cancer stem-like characters and regulation of STAT3 pathway.

Intravenous infusion of human umbilical cord Wharton's jelly-derived mesenchymal stem cells as a potential treatment for patients with COVID-19 pneumonia.

The novel coronavirus disease 2019 (COVID-19) has grown to be a global public health emergency since patients were first detected in Wuhan, China. Thus far, no specific drugs or vaccines are available to cure the patients with COVID-19 infection. The immune system and inflammation are proposed to play a central role in COVID-19 pathogenesis. Mesenchymal stem cells (MSCs) have been shown to possess a comprehensive powerful immunomodulatory function. Intravenous infusion of MSCs has shown promising results in COVID-19 treatment. Here, we report a case of a severe COVID-19 patient treated with human umbilical cord Wharton's jelly-derived MSCs (hWJCs) from a healthy donor in Liaocheng People's Hospital, China, from February 24, 2020. The pulmonary function and symptoms of the patient with COVID-19 pneumonia was significantly improved in 2 days after hWJC transplantation, and recovered and discharged in 7 days after treatment. After treatment, the percentage and counts of lymphocyte subsets (CD3+, CD4+, and CD8+ T cell) were increased, and the level of IL-6, TNF-α, and C-reactive protein is significantly decreased after hWJC treatment. Thus, the intravenous transplantation of hWJCs was safe and effective for the treatment of patients with COVID-19 pneumonia, especially for the patients in a critically severe condition. This report highlights the potential of hWJC infusions as an effective treatment for COVID-19 pneumonia.

Mesenchymal stem cells induced regulatory dendritic cells from hemopoietic progenitor cells through Notch pathway and TGF-ß synergistically.

Mesenchymal stem cells (MSCs) are one of the attractive candidates in regenerative medicine of many clinical applications because of their low immunogenicity and immunomodulatory property. Our previous studies provided that mouse bone marrow-derived Sca-1+MSCs could drive the differentiation of regulatory DC (regDCs) (Scal-1+ BM-MSC-driven DC [sBM-DCs]) from hemopoietic progenitor cells (HPCs) and the Notch pathway played a critical role in maintaining the immunomodulatory property. However, the detailed mechanisms of their immunoregulatory capacity are not fully defined. In the present study, we show that BM-MSCs expressed high levels of Jagged 1 while sBM-DCs expressed high levels of Notch1. Jagged1 expressed on the surface of BM-MSCs initiated Notch signaling to maintain the immunomodulatory property of the sBM-DCs. The level of TGF-ß is high in MSCs, either alone or coculture with HPCs medium. TGF-ß plays a vital role in the proliferation and differentiation of sBM-DCs and inhibition of TGF-ß reduce the number and increase the percentage of CD34, CD117, CD135 of generation cells. Thus, MSCs induced the regDCs from HPCs via the Notch signaling pathway and TGF-ß synergistically. This study further broadens our understanding of the immunomodulatory mechanism and the potential therapeutic efficacy of MSCs.

Synthesis and biological evaluation of celastrol derivatives as anti-ovarian cancer stem cell agents.

Ovarian cancer is associated with a high percentage of recurrence of tumors and resistance to chemotherapy. Cancer stem cells (CSCs) are responsible for cancer progression, tumor recurrence, metastasis, and chemoresistance. Thus, developing CSC-targeting therapy is an urgent need in cancer research and clinical application. In an attempt to achieve potent and selective anti-CSC agents, a series of celastrol derivatives with cinnamamide chains were synthesized and evaluated for their anti-ovarian cancer activities. Most of the compounds exhibited stronger antiproliferative activity than celastrol, and celastrol derivative 7g with a 3,4,5-trimethoxycinnamamide side chain was found to be the most potent antiproliferative agent against ovarian cancer cells with an IC50 value of 0.6 µM. Additionally, compound 7g significantly inhibited the colony formation ability and reduced the number of tumor spheres. Furthermore, compound 7g decreased the percentage of CD44+, CD133+ and ALDH+ cells. Thus, compound 7g is a promising anti-CSC agent and could serve as a candidate for the development of new anti-ovarian cancer drugs.

Synthesis and discovery of 18ß-glycyrrhetinic acid derivatives inhibiting cancer stem cell properties in ovarian cancer cells.

Despite advances in ovarian cancer treatment, the five-year overall survival rate is less than 30% with the presence of cancer stem cells (CSCs). To develop CSC-targeting therapy, a series of 18ß-glycyrrhetinic acid (GA) derivatives containing cinnamamide moiety have been designed, synthesized, and screened for their antiproliferative activity in SKOV3 and OVCAR3 cells. Most of the compounds exhibited stronger antiproliferative activity than GA, and compound 7c was the most active one. Further biological studies showed that compound 7c could induce apoptosis and suppress migration. In addition, compound 7c could not only observably decrease the colony formation and sphere formation ability, but also significantly reduce the CD44+, CD133+, and ALDH+ subpopulation in SKOV3 and OVCAR3 cells. In conclusion, these results indicate that compound 7c is a promising anti-CSC agent for further anti-ovarian cancer studies.

Celastrol strongly inhibits proliferation, migration and cancer stem cell properties through suppression of Pin1 in ovarian cancer cells.

Ovarian cancer is one of the most serious diseases worldwide and the fifth-most common cancer among women. Celastrol, extracted from Thunder God Vine, exerts anti-cancer effects on various cancers; however, the mechanism underlying these anti-cancer effects in ovarian cancer needs further investigation. Herein, we investigated the anti-cancer efficacy of celastrol and its underlying mechanism in human ovarian cancer cell lines A2780, OVCAR3, and SKOV3. Celastrol significantly suppressed cell proliferation and migration in a dose-dependent manner. Celastrol resulted in a G2/M cell cycle arrest, accompanied with the down-regulation of Cyclin D1, CDK2, and CDK4. Celastrol induced apoptosis primarily via up-regulation of caspase-3, caspase-8, and Bax, and down-regulation of Bcl-2. Celastrol treatment inhibited the expression of stem cell marker CD44, Nanog, Klf4, and Oct4, and reduced a portion of the CD44highCD24low cell population. To further understand the cancer therapeutic target, we assessed the effect of celastrol on expression of Pin1, which is reportedly overexpressed in many human cancers and activates more than 40 oncogenes or inactivates more than 20 tumor suppressor genes. We report that celastrol particularly suppressed Pin1 expression, thereby inhibiting Akt, STAT3, P38, JNK, P65, and IL-6 expression. Taken together, these findings indicate that celastrol is a potential therapeutic agent for ovarian cancer in humans via inhibition of Pin1 expression.

Sca1+Lin-CD117- Mouse Bone Marrow-Derived Mesenchymal Stem Cells Regulate Immature Dendritic Cell Maturation by Inhibiting TLR4-IRF8 Signaling Via the Notch-RBP-J Pathway.

Mesenchymal stem cells (MSCs) have a superior immunomodulatory capacity compared to other cells of the immune system, and they hold great promise for treating various immune disorders. However, their regulatory effects on the maturation of immature dendritic cells (imDCs) are not fully understood. In this study, we show that Sca-1+Lin-CD117-MSCs restrain the lipopolysaccharide-stimulated maturation transition of imDCs cocultured without exogenous cytokines. The Notch signaling pathway plays a critical role in the process by controlling interferon regulatory factor 8 (IRF8) expression in an RBP-J-dependent manner. We observed a high degree of H3K27me3 modification mediated by SUZ12 and a relatively low degree of H3K4me3 modification regulated by WDR5 at the IRF8 promoter during coculture. These data reveal a possible mechanism by which Sca-1+Lin-CD117-MSCs modulate imDC maturation and further support the role of MSCs in treating immune disorders.

MicroRNA-23a-3p inhibitor decreases osteonecrosis incidence in a rat model.

The mechanism of steroid-associated femoral head necrosis remains unclear. The present study investigated the role of microRNA-23a-3p (miR-23a-3p) in the incidence of osteonecrosis in a rat model. An miR-23a-3p mimic, an inhibitor and a negative control were transfected into bone mesenchymal stem cells using a lentiviral vector, and then injected into the steroid-induced femoral head necrosis model. Osteonecrosis incidence was assessed by micro computed tomography and histopathology. Low-density lipoprotein receptor-related protein 5 (LRP-5) expression was assessed by immunohistochemistry. The results demonstrated the incidence of osteonecrosis decreased in the miR-23a-3p inhibitor group compared with the miR-23a-3p mimic group (18.2% vs. 75%; P<0.05). The ratio of bone volume/total volume and trabecular thickness were significantly increased in the miR-23a-3p inhibitor group compared with the miR-23a mimic group. The expression level of LRP-5 was higher in the miR-23a-3p inhibitor group. The present study indicated that miR may provide a novel and alternative approach for understanding the mechanism underlying steroid-associated necrosis of the femoral head.

Cytokine-induced killer cells/dendritic cells-cytokine induced killer cells immunotherapy combined with chemotherapy for treatment of colorectal cancer in China: a meta-analysis of 29 trials involving 2,610 patients.

PURPOSE: To systematically evaluate the efficacy and safety of Cytokine-induced killer cells/dendritic cells-cytokine induced killer cells (CIK/DC-CIK) immunotherapy in treating advanced colorectal cancer (CRC) patients. RESULTS: 29 trials including 2,610 CRC patients were evolved. Compared with chemotherapy alone, the combination of chemotherapy with CIK/DC-CIK immunotherapy significantly prolonged the overall survival rate (OS) and disease-free survival rate (DFS) (1-5 year OS, P < 0.01; 1-, 2-, 3- and 5-year DFS, P < 0.01). The combined therapy also improved patients' overall response, disease control rate and life quality (P < 0.05). After immunotherapy, lymphocyte subsets percentages of CD3+, CD3-CD56+, CD3+CD56+ and CD16+CD56+ (P < 0.01) and cytokines levels of IL-2 and IFN-γ (P < 0.05) were increased, while CD4+, CD8+ and CD4+CD25+ and IL-6 and TNF-α did not show significant change (P > 0.05). MATERIALS AND METHODS: Clinical trials reporting response or safety of CIK/DC-CIK immunotherapy treating advanced CRC patients and published before September 2016 were searched in Cochrane Library, EMBASE, PubMed, Wanfang and CNKI database. Research quality and heterogeneity were evaluated before analysis. Pooled analyses were performed using random or fixed-effect models. CONCLUSIONS: The combination of CIK/DC-CIK immunotherapy and chemotherapy prolong CRC patients' survival time, enhanced patients' immune function and alleviates the adverse effects caused by chemotherapy.

Cytokine-induced killer cells/dendritic cells and cytokine-induced killer cells immunotherapy for the treatment of esophageal cancer in China: a meta-analysis.

BACKGROUND: Immunotherapy based on cytokine-induced killer cells or combination of dendritic cells and cytokine-induced killer cells (CIK/DC-CIK) showed promising clinical outcomes for treating esophageal cancer (EC). However, the clinical benefit varies among previous studies. Therefore, it is necessary to systematically evaluate the curative efficacy and safety of CIK/DC-CIK immunotherapy as an adjuvant therapy for conventional therapeutic strategies in the treatment of EC. MATERIALS AND METHODS: Clinical trials published before October 2016 and reporting CIK/DC-CIK immunotherapy treatment responses or safety for EC were searched in Cochrane Library, EMBASE, PubMed, Wanfang and China National Knowledge Internet databases. Research quality and heterogeneity were evaluated before analysis, and pooled analyses were performed using random- or fixed-effect models. RESULTS: This research covered 11 trials including 994 EC patients. Results of this meta-analysis indicated that compared with conventional therapy, the combination of conventional therapy with CIK/DC-CIK immunotherapy significantly prolonged the 1-year overall survival (OS) rate, overall response rate (ORR) and disease control rate (DCR) (1-year OS: P=0.0005; ORR and DCR: P<0.00001). Patients with combination therapy also showed significantly improved quality of life (QoL) (P=0.02). After CIK/DC-CIK immunotherapy, lymphocyte percentages of CD3+ and CD3-CD56+ subsets (P<0.01) and cytokines levels of IFN-γ, -2, TNF-α and IL-12 (P<0.00001) were significantly increased, and the percentage of cluster of differentiation (CD)4+CD25+CD127- subset was significantly decreased, whereas analysis of CD4+, CD8+, CD4+/CD8+ and CD3+CD56+ did not show significant difference (P>0.05). CONCLUSION: The combination of CIK/DC-CIK immunotherapy and conventional therapy is safe and markedly prolongs survival time, enhances immune function and improves the treatment efficacy for EC.

Sca-1+Lin-CD117- mesenchymal stem/stromal cells induce the generation of novel IRF8-controlled regulatory dendritic cells through Notch-RBP-J signaling.

Mesenchymal stem/stromal cells (MSCs) can influence the destiny of hematopoietic stem/progenitor cells (HSCs) and exert broadly immunomodulatory effects on immune cells. However, how MSCs regulate the differentiation of regulatory dendritic cells (regDCs) from HSCs remains incompletely understood. In this study, we show that mouse bone marrow-derived Sca-1(+)Lin(-)CD117(-) MSCs can drive HSCs to differentiate into a novel IFN regulatory factor (IRF)8-controlled regDC population (Sca(+) BM-MSC-driven DC [sBM-DCs]) when cocultured without exogenous cytokines. The Notch pathway plays a critical role in the generation of the sBM-DCs by controlling IRF8 expression in an RBP-J-dependent way. We observed a high level of H3K27me3 methylation and a low level of H3K4me3 methylation at the Irf8 promoter during sBM-DC induction. Importantly, infusion of sBM-DCs could alleviate colitis in mice with inflammatory bowel disease by inhibiting lymphocyte proliferation and increasing the numbers of CD4(+)CD25(+) regulatory T cells. Thus, these data infer a possible mechanism for the development of regDCs and further support the role of MSCs in treating immune disorders.

Mesenchymal stem cells inhibit Th17 cells differentiation via IFN-γ-mediated SOCS3 activation.

Mesenchymal stem cells (MSCs) are immunoregulatory, and the administration of them has been shown to ameliorate inflammation caused by Th17 cells. However, the mechanisms that contribute to MSC regulation on Th17 cell development are unclear. Here, we found that MSCs could inhibit Th17 cell differentiation through the activation of suppressors of cytokine signaling 3 (SOCS3) when coculture of MSCs and CD4(+)CD25(low)CD44(low)CD62L(high) T cells. Further analysis demonstrated that the inhibitory action was mediated via interferon gamma (IFN-γ), which activated signal transducer and activator of transcription-1 (STAT1) to enhance the expression of SOCS3, leading to STAT3 inhibition. Moreover, stable and reciprocal changes in H3K4me3 and H3K27me3 at the promoters of STAT1, STAT3 and RORγt determined the fate of Th17 cells. These results demonstrate that MSCs may inhibit Th17 differentiation via IFN-γ that activates SOCS3 leading to immunomodulatory effects, suggesting a possible mechanism by which MSCs could act as a cellular approach to attenuate the clinical and pathological manifestations of some autoimmune diseases.

Arnebia preventing the expression of Muc1 protein decrease results in anti-implantation in early pregnant mice.

BACKGROUND: The study was designed to explore the relationship between the anti-implantation activity of arnebia and the expression of Muc1 protein in the endometrium of early pregnant mice. STUDY DESIGN: The aqueous extract of arnebia was administered to mice on Days 1-4 postcoitum, and the mice were sacrificed to asses the implantation rate on Day 8 postcoitum. On the night of Day 4 postcoitum and on the morning of Day 5 postcoitum, the treated mice were sacrificed to study the influence on endometrium. The extract of arnebia was administered to mice on Days 11-14 postcoitum, and the mice were sacrificed to asses abortion on Day 18 postcoitum. The reversible effect of arnebia on mice was also studied. RESULTS: The endometrium in the experimental group exhibited morphological changes compared with that in the control group. The expression of Muc1 protein was increased with the increasing doses of arnebia, while in control group, it increased a little. The experiments of pseudopregnancy and normal mice show the identical expression of Muc1. The anti-implantation effect of arnebia was reversible. CONCLUSION: The arnebia may prevent embryo implantation by inhibiting the decrease of the Muc1 protein.