Building on the backbone of CD47-based therapy in cancer: Combination strategies, mechanisms, and future perspectives

Described as a "don't eat me" signal, CD47 becomes a vital immune checkpoint in cancer. Its interaction with signal regulatory protein alpha (SIRPα) prevents macrophage phagocytosis. In recent years, a growing body of evidences have unveiled that CD47-based combination therapy exhibits a superior anti-cancer effect. Latest clinical trials about CD47 have adopted the regimen of collaborating with other therapies or developing CD47-directed bispecific antibodies, indicating the combination strategy as a general trend of the future. In this review, clinical and preclinical cases about the current combination strategies targeting CD47 are collected, their underlying mechanisms of action are discussed, and ideas from future perspectives are shared.

CD47 blockade improves the therapeutic effect of osimertinib in non-small cell lung cancer / 医学前沿

The third-generation epidermal growth factor receptor (EGFR) inhibitor osimertinib (OSI) has been approved as the first-line treatment for EGFR-mutant non-small cell lung cancer (NSCLC). This study aims to explore a rational combination strategy for enhancing the OSI efficacy. In this study, OSI induced higher CD47 expression, an important anti-phagocytic immune checkpoint, via the NF-κB pathway in EGFR-mutant NSCLC HCC827 and NCI-H1975 cells. The combination treatment of OSI and the anti-CD47 antibody exhibited dramatically increasing phagocytosis in HCC827 and NCI-H1975 cells, which highly relied on the antibody-dependent cellular phagocytosis effect. Consistently, the enhanced phagocytosis index from combination treatment was reversed in CD47 knockout HCC827 cells. Meanwhile, combining the anti-CD47 antibody significantly augmented the anticancer effect of OSI in HCC827 xenograft mice model. Notably, OSI induced the surface exposure of "eat me" signal calreticulin and reduced the expression of immune-inhibitory receptor PD-L1 in cancer cells, which might contribute to the increased phagocytosis on cancer cells pretreated with OSI. In summary, these findings suggest the multidimensional regulation by OSI and encourage the further exploration of combining anti-CD47 antibody with OSI as a new strategy to enhance the anticancer efficacy in EGFR-mutant NSCLC with CD47 activation induced by OSI.

c-MYC-mediated TRIB3/P62+ aggresomes accumulation triggers paraptosis upon the combination of everolimus and ginsenoside Rh2

The mammalian target of rapamycin (mTOR) pathway is abnormally activated in lung cancer. However, the anti-lung cancer effect of mTOR inhibitors as monotherapy is modest. Here, we identified that ginsenoside Rh2, an active component of Panax ginseng C. A. Mey., enhanced the anti-cancer effect of the mTOR inhibitor everolimus both in vitro and in vivo. Moreover, ginsenoside Rh2 alleviated the hepatic fat accumulation caused by everolimus in xenograft nude mice models. The combination of everolimus and ginsenoside Rh2 (labeled Eve-Rh2) induced caspase-independent cell death and cytoplasmic vacuolation in lung cancer cells, indicating that Eve-Rh2 prevented tumor progression by triggering paraptosis. Eve-Rh2 up-regulated the expression of c-MYC in cancer cells as well as tumor tissues. The increased c-MYC mediated the accumulation of tribbles homolog 3 (TRIB3)/P62+ aggresomes and consequently triggered paraptosis, bypassing the classical c-MYC/MAX pathway. Our study offers a potential effective and safe strategy for the treatment of lung cancer. Moreover, we have identified a new mechanism of TRIB3/P62+ aggresomes-triggered paraptosis and revealed a unique function of c-MYC.

Ursolic acid ameliorates azoxymethane/dextran sulfate sodium-caused colorectal cancer by inhibition of Wnt signaling cascade / 中国药理学与毒理学杂志

OBJECTIVE To investigate the pharmacological effect of ursolic acid (UA) on colitis-associated colorec?tal cancer (CAC) and its underlying mechanism based on the Wnt signaling pathway. METHODS The CAC model in mice was established by azoxymethane (AOM) combined and dextran sulfate sodium salt (DSS), accompanied by treat?ment with various dosages of UA and concomitant appraisal of body weight, stool and physical state of the mice. After the sacrifice of the mice, the tumor and length of the colorectum were measured, followed by retrieval of the liver, spleen, thymus and tumor tissue for downstream assays. The levels of inflammatory factors interleukin-6 (IL-6), IL-1βand C-reactive protein (CRP) in the tumor and serum were examined by enzyme-linked immunosorbent assay (ELISA). The pathological changes of colorectal tissues were observed by HE staining. The levels in tumors of Wnt/β-catenin sig?naling pathway-related proteins Wnt4, GSK-3β, β-catenin, TCF4, LEF1, c-Myc, cyclin D1 and apoptosis-related protein Bcl-2 were assayed by immunohistochemistry (IHC). The mRNA expressions of Wnt4, GSK-3β,β-catenin, TCF4, LEF1, c-Myc, cyclin D1, Bcl-2, Bax, caspase-9 and caspase-3 in tumors were detected by real-time quantitative RT-PCR (RT-qPCR). The protein levels of Wnt4, GSK-3β, β-catenin, TCF4, LEF1, c-Myc, cyclin D1, phospho-β-catenin, phospho-GSK-3β, Bcl-2 and Bax in tumors were probed by analyzed by Western blotting (WB). Also, RNA-seq was employed to assess the gut microbiota in the mice. RESULTS UA significantly ameliorated the symptoms of AOM/DSS-induced mouse CAC, evidenced by improved physical state, body weight, survival rate, colorectal length, the mass of liver, thy?mus, spleen, and decreased CAC load and colorectal mass. UA attenuated the levels of IL-6, IL-1β and CRP in the mouse serum and colorectal tumor in a dose-dependent manner. HE staining showed that UA lessened carcinogenesis in the colorectum, with lower infiltration of lymphocytes, versus the control. IHC indicated that UA mitigated the expres?sion of Wnt4,β-catenin, TCF4, LEF1, c-Myc, cyclin D1, Bcl-2, and promoted the GSK-3βexpression, compared with the control. Furthermore, UA diminished the mRNA expressions of Wnt4, β-catenin, TCF4, LEF1, c-Myc, cyclin D1, Bcl-2, and heightened the mRNA levels of GSK-3β, caspase-3, capase-9 and Bax in CAC. The results of mRNA expressions were verified by WB analysis, which revealed that UA impeded the protein expression of Wnt4,β-catenin, c-Myc, cyclin D1, Bcl-2, TCF4, LEF1, and elevated the protein levels of GSK-3βand Bax, phospho-β-catenin in mouse CAC. In addi?tion, UA substantially ameliorated the gut microbiota to store the metabolic function in the mice with CAC. CONCLU?SION Ursolic acid may protect against CAC, potentially by downregulation of Wnt/β-catenin signaling pathway activity and restoration of gut microbiota.

Scutellarin induces apoptosis of colorectal cancer HCT116 cells via Hippo signaling pathway / 中国药理学与毒理学杂志

OBJECTIVE To investigate the effect of scutellarin on the apoptosis of human colorectal cancer cells via the Hippo signaling pathway in vitro. METHODS MTT colorimetric method was used to detect the influence of scutellar?in on the survival rate of HCT116 cells. And the effect of scutellarin at various concentrations on cell morphology was observed by microscopy. Cell scratch experiment was used to detect the influence of scutellarin on the migration of HCT116 cells. Hoechst33342/PI double staining method was used to detect the effect of scutellarin on the apoptosis of HCT116 cells. Western blotting method was used to assess the action of scutellarin on the expressions of Hippo signal?ing pathway-related proteins Mst1, Lats1, YAP1, p-YAP(Ser127), TAZ, and its downstream effector proteins c-Myc and cyclin D1, as well as apoptosis-related proteins Bcl-2 and Bax in HCT116 cells. RESULTS Scutellarin significantly affected the morphology of HCT116 cells and reduced the survival rate of HCT116 cells. Hoechst33342/PI double stain?ing showed that scutellarin effectively induced the apoptosis of HCT116 cells. Western blotting analysis showed that the expression levels of Hippo signaling pathway-related proteins Mst1, Lats1, YAP1, TAZ and its downstream effector pro?teins c-Myc, cyclin D1 were down-regulated in a concentration-dependent manner by scutellarin, and the expression of p-YAP (ser127) was up-regulated. Moreover, scutellarin substantially lessened the expression level of apoptosis-related protein Bcl-2, and promoted the protein level of Bax. CONCLUSION Scutellarin may inhibit the proliferation and migra?tion of HCT116 cells, while induce its apoptosis, potentially by activation of Hippo signaling pathway.

Inhibitory action of berberine on colorectal cancer HCT116 cells by regulation of Hedgehog signaling pathway / 中国药理学与毒理学杂志

OBJECTIVE To investigate the inhibition and mechanism of berberine on human colorectal cancer HCT116 cells through canonical Hedgehog signaling pathway. METHODS The effect of berberine on cell morphology was observed by microscopy. MTT colorimetric assay, cell scratch experiment, colony formation assay and Hoechest/PI staining were utilized to detect the activities of berberine on cell viability, cell migration and cell apoptosis. Flow cytome?try was applied to examine the cell apoptosis. The effects of berberine on caspase-3 and caspase-9 were detected by caspase activity detection kit. The expressions of Hedgehog signaling pathway-related proteins SHH, GLI1, PTCH1, SMO, SUFU, apoptosis-related proteins Bax and Bcl-2 as well as cell cycle-related proteins cyclin D1 were detected by Western blotting. Additionally, quantitative real time RT-PCR was employed to assess the mRNA expression levels of Hedgehog signaling pathway-related genes SHH, GLI1, PTCH1, SMO, SUFU, apoptosis-related genes Bax and Bcl-2 as well as cell cycle-related genes cyclin D1. RESULTS Berberine sharply altered the morphology of human colorectal cancer HCT116 cells, demonstrated by that migration ability of HCT116 cells was reduced significantly and the nuclei were densely stained. Berberine could induce apoptosis in a dose-dependent manner. The activities of caspase-3 and caspase-9 were increased prominently. The expression levels of Hedgehog signaling pathway-related protein SUFU and apoptosis-related protein Bax were augmented substantially. The expression levels of Hedgehog signaling pathway-related proteins SHH, GLI1, PTCH1, SMO, apoptosis-related protein Bcl-2 as well as cell cycle-related genes cyclin D1 were markedly lessened. Besides, the mRNA expression levels of Hedgehog signaling pathway-related gene SUFU and apoptosis-related gene Bax were augmented substantially. The mRNA expression levels of Hedgehog signaling path?way-related genes SHH, GLI1, PTCH1, SMO, apoptosis-related gene Bcl-2 as well as cell cycle-related gene cyclin D1 were markedly lessened. CONCLUSION Berberine, which is the main component of coptidis rhizoma, can remarkably restrain the growth and proliferation, promote apoptosis of human colorectal cancer cells HCT116, and the underlying mechanism may be involved in suppressing the activity of the Hedgehog signaling pathway.

Research advances in phytochemistry, pharmacology and toxicology of oleanolic acid / 中国药理学与毒理学杂志

Oleanolic acid (OA) is a pentacyclic triterpenoid chemical component that exists in natural plants with a molecular formula of C30H48O3 and a molecular weight at 456.71 g·mol-1. OA is widespread in traditional Chinese herbal medicine (Ligustri Lucidi Fructus, Achyranthis Bidentate Radix, Red Sage) and berries (blueberries, grapes). In recent years, because of the extensive pharmacological effects of OA, its advantages in disease treatment have become increasingly prominent and gradually attracted the attention of pharmaceutical researchers. OA has effective therapeutic effects on a series of chronic diseases such as inflammation, cancer, diabetes, and cardiovascular diseases through mul?tiple signaling pathways and various targets. Especially in cancers, such as colorectal cancer, liver cancer, gastric cancer, lung cancer, breast cancer and other malignancies, OA presents substantial efficacy. However, its poor aqueous solubility, needy bioavailability, and unsatisfactory pharmacological activity excessively restrict its clinical application. More impor?tantly, the improper utilization of OA can cause adverse reactions, toxic effects and even damage to organs in some spe?cific situations. With the discovery of various pharmacological effects, the complex action mechanisms of OA, the contin?uous progress in structural modification of OA, as well as the synthesis of OA derivatives, its application is expand?ing gradually. Among numerous studies, there is a clear indication that OA and its derivatives, if fully developed, may provide an alternative and cheaper treatment for a variety of chronic diseases. However, the specific molecular mecha?nisms of OA and its derivatives as an alternative therapy and supplementary therapy for cancer, diabetes, cardiovascular disease and other chronic diseases remain to be clarified. Therefore, it is necessary to further study the pharmacokinet?ics, pharmacological activity, specific targets and related mechanisms of OA to lay a solid foundation for drug devel?opment and the application of OA in clinical settings.

Pulsatilla chinensis:phytochemistry, pharmacology and new drug development / 中国药理学与毒理学杂志

Pulsatilla chinensis is a widely used traditional Chinese herb, which contains 56 types of chemical constit?uents, mainly including triterpenoid saponins, organic acids, coumarins and lignans. The largest portion of the ingredi?ents in Pulsatilla chinensis is the family of triterpenoid saponins, in which anemoside B4 is the major effective compound and indexing component. The main components of Pulsatilla chinensis can metabolize into a vast array of active prod?ucts in vivo, which play vital roles in its biological activity. Mounting evidence reveals that Pulsatilla chinensis exerts a wide range of therapeutic activities, such as anti-cancer, immunoregulation, anti-inflammation and anti-schistosome, with fewer adverse reactions, via various signaling pathways and multiple targets. It was documented that the active ingre?dient of Pulsatilla chinensis can lessen the drug resistance and synergize the effects of other natural products includ?ing paclitaxel, as well as ameliorate the clinical efficacy of chemical drugs, such as adriamycin. However, Pulsatilla chi?nensis was also reported to be possibly the main cause of hemolysis and chronic liver injury. The efforts should be made to deeply investigate the pharmacological actions and underlying mechanisms of Pulsatilla chinensis, with a focus on the anti-cancer efficacy, and develop new drugs based on the components of Pulsatilla chinensis for future utilization in the clinical setting.

Myricetin inhibits interferon-γ-induced programmed death ligand-1 and indoleamine 2, 3-dioxygenase 1 expression in lung cancer cells / 中国药理学与毒理学杂志

OBJECTIVE Programmed death ligand-1 (PD-L1) and indoleamine 2, 3-dioxygenase 1 (IDO1) are immune checkpoints which can be induced by interferon-γ(IFN-γ) in the tumor microenvironment, leading to immune escape of tumors. Myricetin (MY) is a flavonoid distributed in many edible and medicinal plants. The aim of this study is to clarify the effect and the mechanism of MY on inhibiting IFN-γ-induced PD-L1 and IDO1 in lung cancer cells. METHODS Expressions of PD-L1 and major histocompatibility complex-I (MHC-I) were evaluated by flow cytometry and Western blotting, and the expression of IDO1 was measured by Western blotting. qRT-PCR was used to detect their mRNA levels. The function of T cells was evaluated using a co-culture system consist of lung cancer cells and the Jurkat-PD-1 T cell line that overexpressing PD-1. Molecular docking analysis, Western blotting and immunofluorescence were used for mechanism study. RESULTS MY potently inhibited IFN-γ-induced PD-L1 and IDO1 expression in human lung cancer cells, while didn't show obvious effect on the expression of MHC-I. In addition, MY restored the survival, proliferation, CD69 expression and interleukin-2 (IL-2) secretion of Jurkat-PD-1 T cells suppressed by IFN-γ-treated lung cancer cells in the co-culture system. Mechanistically, IFN-γ up-regulated PD-L1 and IDO1 at the transcriptional level through the JAK-STAT-IRF1 axis, which was targeted and inhibited by MY. CONCLUSION Our research revealed a new insight into the anti-tumor effects of MY which inhibited IFN-γ-induced PD-L1 and IDO1 expression, supporting the potential of MY in anti-tumor immunotherapy.

Inhibition of colorectal cancer by ursolic acid via noncanonical Hedgehog signaling pathway / 中国药理学与毒理学杂志

OBJECTIVE To identify the inhibitory effect of ursolic acid on the colorectal cancer HCT116 cells in vitro and in vivo, and to explore the underlying mechanism. METHODS The smoothened (SMO) gene-silenced human colorectal cancer HCT116hSMO- cell line was established by transfection with the lentivirus carrying SMO shRNA. The cytotoxic effect of ursolic acid on HCT116hSMO-cells was determined by MTT assay. The effect of ursolic acid on the migration of HCT116hSMO- cells was studied by wound healing assay. The effect of ursolic acid on apoptosis of HCT116hSMO-cells was explored by Hoechst33342/PI double staining and flow cytometry. The effects of ursolic acid on the expressions of apoptotic marker gene Bcl-2, Bax, caspase-3 and caspase-9 were measured by real-time quantitative RT-PCR (RT-qPCR) and Western blotting (WB) analysis. RT-qPCR and WB were used to examine the relationship between GLI1, c-Myc expression and PI3K/Akt pathway to further investigate the mechanism of GLI1 activation in HCT116hSMO- cells. The effects of ursolic acid on the expressions of GLI1, p-Akt, Akt, c-Myc, SHH and SUFU of nonca?nonical Hedgehog pathway were evaluated by RT-qPCR and WB assays. Xenograft nude mouse model bearing HCT116hSMO- cells was established and intraperitoneally treated with ursolic acid to investigate the effect on tumor growth in vivo. The body weight and tumor size of mice were assessed regularly every 2 d. The effect of ursolic acid on the apoptosis of tumor tissue was determined by TUNEL assay. The expressions of Bcl-2, Bax, GLI1, p-Akt, Akt, c-Myc, SHH, SUFU mRNA and proteins were measured by RT-qPCR and WB. The levels of Bcl-2, Bax, GLI1, p-Akt, c-Myc and SHH proteins in tumor tissues were also evaluated by immunohistochemistry. RESULTS Ursolic acid significantly inhibited the growth and migration of HCT116hSMO-cells in vitro, compared with the control (P<0.05). Meanwhile, ursolic acid also induced apoptosis of HCT116hSMO- cells in vitro (P<0.05). Furthermore, SC79 (Akt activator) enhanced the expressions of p-Akt, GLI1 and c-Myc, which could be abolished by ursolic acid, and the effect was equal to Akt inhibitor LY294002. The expressions of Bcl-2, GLI1, p-Akt, c-Myc, SHH mRNA and proteins were reduced by ursolic acid, while the levels of Bax and SUFU were increased. Ursolic acid could inhibit the growth and induce the apoptosis of colorectal cancer xeno?graft in vivo. Similarly, lower levels of Bcl-2, GLI1, p-Akt, c-Myc and SHH, and higher expression of Bax and SUFU were noted in ursolic acid-treated mice. CONCLUSION Ursolic acid can inhibit the growth and induce apoptosis of HCT116hSMO- cells both in vitro and in vivo. And the mechanism is related to the suppression of PI3K/Akt-mediated noncanonical Hedgehog signaling pathway.

Suppression of AOM/DSS-induced colorectal cancer by scutellarin through downregulation of Wnt signaling pathway activity / 中国药理学与毒理学杂志

OBJECTIVE To investigate the therapeutic effect of scutellarin on colitis-associated cancer (CAC) and its underlying mechanism based on Wnt/β-catenin signaling pathway. METHODS The mouse model of CAC was estab?lished by azomethane oxide (AOM) and sodium dextran sulfate (DSS), followed by scutellarin treatment, with recording the body weight, diarrhea and hematochezia. After sacrificing the mice, the colorectal length and colorectal tumor were assessed. The levels of pro-inflammatory factors TNF-α and IL-6 in mice's sera were measured by the enzyme-linked immunosorbent assay (ELISA). The colorectal lesions were appraised by hematoxylin and eosin (H&E) staining. Theβ-catenin level in CAC tissues was probed by immunofluorescent analysis. The apoptosis-related genes Bax and Bcl-2, and Wnt signaling pathway-related genes β-catenin, GSK-3β, TCF4, c-Myc and cyclin D1 were detected by real-time quantitative RT-PCR (RT-qPCR). Finally, Western blotting analysis (WB) was employed to examine the expressions of the apoptosis and Wnt signaling pathway-related proteins. RESULTS Scutellarin significantly improved AOM/DSS-caused weight loss, colorectal length shortening, and tumor growth in mice (P<0.01). Meanwhile, colorectal lesions could be substantially alleviated by scutellarin. ELISA results showed that the levels of pro-inflammatory factors TNF-αand IL-6 were drastically lessened (P<0.01). Scutellarin also sharply inhibited the nuclear translocation of β-catenin, as evidenced by the reduction in the nuclear level ofβ-catenin protein. In addition, scutellarin attenuated the mRNA expres?sion of Wnt signaling pathway-relatedβ-catenin, TCF4, c-Myc and cyclin D1, whereas it heightened GSK-3βmRNA level. These results were consolidated by WB analysis, which indicated that scutellarin could mitigate the protein levels of phospho-GSK-3β,β-catenin, TCF4, c-Myc and cyclin D1, with the increase in GSK-3β protein in CAC tissue. Moreover, scutellarin could induce the apoptosis of CAC, demonstrated by enhanced expression of Bax and diminished expression of Bcl-2 in both mRNA and protein levels. CONCLUSION Scutellarin may ameliorate colitis-associated colorectal cancer by weakening Wnt/β-catenin signaling cascade.

Nagilactone E increases PD-L1 expression through activation of c-Jun in lung cancer cells / 中国天然药物

Nagilactone E (NLE), a natural product with anticancer activities, is isolated from Podocarpus nagi. In this study, we reported that NLE increased programmed death ligand 1 (PD-L1) expressions at both protein and mRNA levels in human lung cancer cells, and enhanced its localization on the cell membrane. Mechanistically, NLE increased the phosphorylation and expression of c-Jun, and promoted the localization of c-Jun in the nucleus, while silencing of c-Jun by small interfering RNA (siRNA) reduced NLE-induced PD-L1. Further study showed that NLE activated the c-Jun N-terminal kinases (JNK), the upstream of c-Jun, and its inhibitor SP600125 reversed the NLE-increased PD-L1. Moreover, NLE-induced PD-L1 increased the binding intensity of PD-1 on the cell surface. In summary, NLE upregulates the expression of PD-L1 in lung cancer cells through the activation of JNK-c-Jun axis, which has the potential to combine with the PD-1/PD-L1 antibody therapies in lung cancer.

Cucurbitacin B suppresses metastasis mediated by reactive oxygen species (ROS) via focal adhesion kinase (FAK) in breast cancer MDA-MB-231 cells / 中国天然药物

Metastasis is responsible for the majority of cancer-related deaths and prevention of metastasis remains a big challenge for cancer therapy. Cucurbitacin B (Cuc B) is a natural triterpenoid with potent anticancer activities while its effect on metastasis remains unclear. In the present study, the inhibitory effect and mechanisms of Cuc B on metastasis were investigated in MDA-MB-231 breast cancer cells. The cells were treated with or without Cuc B, and the cytotoxicity was determined by MTT assay. The effect of Cuc B on metastasis was evaluated with wound healing, transwell, and adhesion assays. Furthermore, the adhesion of cancer cells to endothelial cells was determined. The protein expression was determined by Western blotting. Cuc B (< 100 nmol·L) showed no obvious cytotoxicity to MDA-MB-231 cells, but significantly inhibited migration, invasion, and adhesion to Matrigel, fibronectin, type I collagen, and endothelial cells. Cuc B dramatically inhibited the phosphorylation of focal adhesion kinase (FAK) and paxillin in dose- and time-dependent manners. Furthermore, Cuc B induced intracellular reactive oxygen species (ROS) generation, which could be reduced by N-acetyl-l-cysteine (NAC). In addition, NAC pretreatment could reverse Cuc B-induced suppression of migration and adhesion, expression of FAK, but showed no effect on paxillin expression. In summary, Cuc B suppressed ROS-dependent metastasis through FAK pathway in breast cancer MDA-MB-231 cells, demonstrating novel mechanisms for the anticancer effects of Cuc B.

NQO1 dependent non-canonical necroptosis mediated by ROS and RIP1/RIP3 in parallel in glioma cancer cells / 中国药理学与毒理学杂志

OBJECTIVE Glioblastomas(GBM)are the most malignant brain tumors in humans and have a very poor prognosis. New therapeutics are urgently needed. Here, we reported 2-methoxy-6-acetyl-7-methyljuglone (MAM)-induced cell death in U87 and U251 glioma cancer cells. METHODS Cells were cultured and treated with MAM, the cell viability was determined by MTT assay and LDH assay. Intracellular reactive oxygen species (ROS) generation was observed by DCF fluorescence. The protein expression was determined by Western blotting. RESULTS MAM induced glioma cancer cell death without caspase activation. The cell death induced by MAM was attenuated by the pharmacological or genetic blockage of necroptosis signaling,including RIP1 inhibitor necrostatin-1s (Nec-1s)and siRNA-mediated gene silencing of RIP1 and RIP3,but was unaffected by caspase inhibitor z-vad-fmk or necrosis inhibitor 2-(1H-Indol-3-yl)-3-pentylamino-maleimide (IM54). MAM treated U87 and U251 glioma cancer cells induced RIP1/RIP3 complex formation, ROS level increased, ATP concentration decreased and loss of plasma membrane integrity, further confirmed this process was necroptosis.The essential role of ROS was confirmed by the protective effect of ROS scavenger NAC. Interestingly, MAM induced necroptosis both triggered by RIP1/RIP3 complex and ROS generation. Moreover, MAM induced necroptosis through cytosolic calcium (Ca2 +) accumulation and sustained c-Jun N-terminal kinase (JNK) activation. Both calcium chelator BAPTA-AM and JNK inhibitor SP600125 could attenuate cell death. Further, we found there exists a feedback loop between RIP1 and JNK activation.Finally,MAM induced necroptosis was inhibited by dicoumarol(a NQO1 inhibitor). Dicoumarol exposed glioma cancer cells were resistant to RIP1/RIP3 complex formation and ROS generation. MAM induced necroptosis was independent of MLKL. CONCLUSION MAM induced non-canonical necroptosis through the NQO1-dependent ROS and RIP1/RIP3 pathway.This study also provided new insights into the molecular regulation of necroptosis in human glioma cancer cells and a promising approach for GBM treatment.

Cucurbitacin B suppresses metastasis mediated by reactive oxygen species (ROS) via focal adhesion kinase (FAK) in breast cancer MDA-MB-231 cells / 中国天然药物

Metastasis is responsible for the majority of cancer-related deaths and prevention of metastasis remains a big challenge for cancer therapy. Cucurbitacin B (Cuc B) is a natural triterpenoid with potent anticancer activities while its effect on metastasis remains unclear. In the present study, the inhibitory effect and mechanisms of Cuc B on metastasis were investigated in MDA-MB-231 breast cancer cells. The cells were treated with or without Cuc B, and the cytotoxicity was determined by MTT assay. The effect of Cuc B on metastasis was evaluated with wound healing, transwell, and adhesion assays. Furthermore, the adhesion of cancer cells to endothelial cells was determined. The protein expression was determined by Western blotting. Cuc B (< 100 nmol·L) showed no obvious cytotoxicity to MDA-MB-231 cells, but significantly inhibited migration, invasion, and adhesion to Matrigel, fibronectin, type I collagen, and endothelial cells. Cuc B dramatically inhibited the phosphorylation of focal adhesion kinase (FAK) and paxillin in dose- and time-dependent manners. Furthermore, Cuc B induced intracellular reactive oxygen species (ROS) generation, which could be reduced by N-acetyl-l-cysteine (NAC). In addition, NAC pretreatment could reverse Cuc B-induced suppression of migration and adhesion, expression of FAK, but showed no effect on paxillin expression. In summary, Cuc B suppressed ROS-dependent metastasis through FAK pathway in breast cancer MDA-MB-231 cells, demonstrating novel mechanisms for the anticancer effects of Cuc B.

Hypaconitine inhibits TGF-β1-induced epithelial-mesenchymal transition and suppresses adhesion, migration, and invasion of lung cancer A549 cells / 中国天然药物

Epithelial-mesenchymal transition (EMT) has been implicated in tumor invasion and metastasis and provides novel strategies for cancer therapy. Hypaconitine (HpA), a diester-diterpenoid alkaloid isolated from the root of the Aconitum species, exhibits anti-inflammatory, analgesic, and especially, cardiotoxic activities. Here, we reported the anti-metastatic potentials of HpA in transforming growth factor-β1 (TGF-β1)-induced EMT in lung cancer A549 cells. The cytotoxic effect of HpA was determined by MTT assay. A549 cells were treated with TGF-β1 with or without HpA co-treatment, and the morphological alterations were observed with a microscopy. The expression of E-cadherin, N-cadherin, and NF-κB was determined by both Western blotting and immunofluorescence analyses. The adhesion, migration, and invasion were detected with Matrigel, wound-healing, and transwell assays, respectively. The expression of Snail was determined by Western blotting. The expression of NF-κB p65, IκBα, and p-IκBα in nuclear and cytosolic extracts was assessed by Western blotting. The results showed that low concentration of HpA (<16 μmol·L) had no obvious cytotoxicity to A549 cells. Morphologically, TGF-β1 treatment induced spindle-shaped alteration in the cells. The upregulation of N-cadherin, NF-κB, and Snail and the downregulation of E-cadherin were detected after TGF-β1 treatment. The adhesion, migration and invasion abilities were also increased by TGF-β1. Besides, TGF-β1 induced expression of Snail in a time-dependent manner. Furthermore, TGF-β1 induced nuclear translocation of NF-κB p65. All these alterations were dramatically inhibited by HpA co-treatment. In addition, the NF-κB inhibitor PDTC showed similar inhibitory effect. In conclusion, these results showed that HpA inhibited TGF-β1-induced EMT in A549 cells, which was possibly mediated by the inactivation of the NF-κB signaling pathway, providing an evidence for anti-cancer effect of HpA.

Proteomic analysis of hepatocellular carcinoma HepG2 cells treated with platycodin D / 中国天然药物

Platycodin D (PD), a triterpenoid saponin isolated from Platycodonis Radix, is a famous Chinese herbal medicine that has been shown to have anti-proliferative effects in several cancer cell lines. The aim of this study was to determine the changes in cellular proteins after the treatment of hepatocellular carcinoma HepG2 cells with PD using proteomics approaches. The cell viability was determined using the MTT assay. The proteome was analyzed by two-dimensional difference gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Western blot analysis was used to confirm the expression of changed proteins. Our results showed that PD inhibited the proliferation of HepG2 cells in concentration- and time-dependent manners. Sixteen proteins were identified to be up-regulated in PD-treated HepG2 cells, including ATP5H, OXCT1, KRT9, CCDC40, ERP29, RCN1, ZNF175, HNRNPH1, HSP27, PA2G4, PHB, BANF1, TPM3, ECH1, LGALS1, and MYL6. Three proteins (i.e., RPS12, EMG1, and KRT1) decreased in HepG2 cells after treatment with PD. The changes in HSP27 and PHB were further confirmed by Western blotting. In conclusion, our results shed new lights on the mechanisms of action for the anti-cancer activity of PD.

Current topics on cancer biology and research strategies for anti-cancer traditional Chinese medicine / 中国中药杂志

Cancer, an abnormal cell proliferation resulted from multi-factors,has the highest morbidity and mortality among all the serious diseases. Considerable progress has been made in cancer biology in recent years. Tumor immunology, cancer stem cells (CSCs), autophagy, and epithelial-mesenchymal transition (EMT) have become hot topics of interests in this area. Detailed dissection of these biological processes will provide novel directions, targets, and strategies for the pharmacological evaluation, mechanism elucidation, and new drug development of traditional Chinese medicine.

Recent advances in natural product induced DNA damage response in cancer cells / 中国中药杂志

The DNA structures could be altered or even damaged by exogeous or endogenous factors during cell proliferation. Failure of effective and timely repair will lead to cell cycle arrest or apoptosis. By taking the advantage of the quick proliferation of cancer cells, DNA damage induction, cell cycle arrest and apoptosis promotion have become important strategies for ant-cancer chemotherapy. Previous reports showed that an array of natural compounds inhibit cancer cell proliferation by inducing DNA damage, which have therapeutic potentials for anti-cancer drug research and development.

Inspirations from natural products based drug research and development for Chinese medicine research--analysis of natural products recoded in TTD / 药学学报

Natural product is an important source of new drug research and development (R&D). Traditional Chinese medicine (TCM) innovation is the key step for its modernization and internationalization. However, due to the complexity of TCM, there are many difficulties and confusions in this process. Target-based drug discovery is the mainstream model and method of R&D. TTD, short for therapeutic target database, is developed by National University of Singapore. Besides a large amount of information on drug targets, the database also contains considerable information related to natural products. This paper briefly introduces the TTD, analyzes the natural products derived drugs/compounds recorded in TTD, which we think might provide some inspiration for the innovation of TCM.