Oxyfadichalcone C inhibits melanoma A375 cell proliferation and metastasis via suppressing PI3K/Akt and MAPK/ERK pathways

A novel, glutathione-activated prodrug of pimasertib loaded in liposomes for targeted cancer therapy

Pimasertib, a potent antiproliferative drug, has been extensively studied for treating cancers characterized by dysregulation in the ERK/MAPK signaling pathway, such as melanoma. However, its therapeutic efficacy would greatly benefit from an increased selectivity for tumour cells and a longer half-life. Such improvements may be achieved by combining the rational design of a prodrug with its encapsulation in a potential nanodelivery system. For this reason, we synthesized a glutathione (GSH)-responsive putative prodrug of pimasertib (PROPIMA), which contains a redox-sensitive disulphide linker that can be processed by GSH to activate pimasertib. The synthesis of PROPIMA and its in vitro biological activity on a human melanoma cell line as a model are described. The results showed that PROPIMA, either free or embedded in liposomes, selectively inhibits cell proliferation and cell viability, reducing by about 5-fold the levels of pERK. Additionally, PROPIMA shows stronger inhibition of the cancer cell migration than the parent drug.

Promotion of apoptosis in melanoma cells by taxifolin through the PI3K/AKT signaling pathway: Screening of natural products using WGCNA and CMAP platforms

Melanoma is a skin cancer originating from melanocytes. The global incidence rate of melanoma is rapidly increasing, posing significant public health challenges. Identifying effective therapeutic agents is crucial in addressing this growing problem. Natural products have demonstrated promising anti-tumor activity. In this study, a plant flavonoid, taxifolin, was screened using Weighted Correlation Network Analysis (WGCNA) in combination with the Connectivity Map (CMAP) platform. Taxifolin was confirmed to inhibit the proliferation, migration, and invasion ability of melanoma A375 and MV-3 cells by promoting apoptosis. Additionally, it suppressed the Epithelial-Mesenchymal Transition (EMT) process of melanoma cells. Cyber pharmacological analysis revealed that taxifolin exerts its inhibitory effect on melanoma through the PI3K/AKT signaling pathway, specifically by downregulating the protein expression of p-PI3K and p-AKT. Notably, the addition of SC-79, an activator of the PI3K/AKT signaling pathway, reversed the effects of taxifolin on cell migration and apoptosis. Furthermore, in vivo experiments demonstrated that taxifolin treatment slowed tumor growth in mice without significant toxic effects. Based on these findings, taxifolin holds promise as a potential drug for melanoma treatment.

The genus Oxytropis DC: application, phytochemistry, pharmacology, and toxicity

OBJECTIVES

Oxytropis DC is a perennial plant of Fabaceae family, which is widely distributed in the northern temperate zone. It is known as "locoweed" because of its toxic component swainsonine. However, it is widely used in Tibetan medicine and Mongolian medicine, mainly for the treatment of heat-clearing and detoxifying, pain-relieving, anti-inflammatory, hemostasis, and other diseases. To provide a basis for the further development and utilization of Oxytropis DC, the pieces of literature about the application, phytochemistry, pharmacological action, and toxicity of Oxytropis DC were reviewed and analyzed.

KEY FINDINGS

A total of 373 chemical constituents were found from Oxytropis DC, including flavonoids, alkaloids, steroids, terpenoids, and others. Pharmacological actions mainly include antitumor, antioxidation, anti-inflammatory, analgesic, antibacterial, antifibrosis, and other pharmacological actions, among them, the antitumor effect is particularly prominent.

SUMMARY

At present, studies on its pharmacological effects are mainly concentrated on the extracts, some flavonoids, and alkaloids. In the follow-up studies, research on the pharmacological activities of the other chemical constituents in Oxytropis should be strengthened. It has the potential to pave the way for research and development of novel Oxytropis medicines.

Upregulation of MMPs in placentas of patients with gestational diabetes mellitus: Involvement of the PI3K/Akt pathway

In recent years, there has been a notable rise in the incidence of pregnancies complicated by gestational diabetes mellitus (GDM), characterized by glucose intolerance first identified during pregnancy. Analysis of placental tissue has revealed that placentas from women with GDM tend to be larger and heavier compared to control placentas, indicating potential changes in trophoblast proliferation, differentiation, and apoptosis. In this study, transcriptome sequencing was conducted on placentas obtained from both normal pregnancies and pregnancies with GDM to investigate the molecular mechanisms underlying this condition. The original sequencing data were subjected to sequencing analysis, resulting in the identification of 935 upregulated genes and 256 downregulated genes. The KEGG and GO analysis techniques on differential genes uncovered evidence suggesting that the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway may contribute to the pathogenesis of GDM. Subsequent analysis indicated that the expression levels of matrix metalloproteinases (MMP) 11, MMP12, MMP14, and MMP15, which are regulated by the PI3K/Akt pathway, were upregulated in the placentas of patients with GDM when compared to those of individuals with normal placental function. Additionally, our investigation into alternative splicing patterns revealed an increase in exon skipping alternative splicing of CSF3R in the placenta of patients with GDM compared to that in the control group. The CSF3R-PI3K-MMP pathway is speculated to regulate the pathogenesis of GDM.

Yin Yang 1 impacts upon preeclampsia by regulating Treg/TH17 cells and PI3K/AKT pathway

Preeclampsia (PE) is a common obstetric syndrome with an unclear etiology and pathogenesis. The study here aimed to investigate the role of Yin Yang 1 (YY1) in PE, and to reveal any YY1-regulated mechanisms in PE. Peripheral blood, placenta, and endometrial tissues of PE patients, healthy volunteers, and patients who had undergone an elective Cesarean section and had a scarred uterus (control group) were collected for analyses. Rat PE models were established by lipopolysaccharide induction. Subsets of these rats were then made to over-express YY1. At 18 d after the PE was established, urine, blood, and placental tissues from all rats were collected. Levels of regulatory-T (T_reg) and helper T-type 17 (T_H17) cells in both human and rat blood were measured by flow cytometry. ELISA kits were used to evaluate blood levels of inflammatory factors (i.e. IL-6, IL-10, and IL-17) as well. RT-qPCR and Western blot assays were performed to quantify levels of forkhead box P3 (Foxp3), retinoic acid-related orphan receptor C (RORc), and YY1 in the human and rat placenta and endometrial tissues. Expressions of PI3K/AKT pathway-related proteins were also evaluated by Western blots. The results indicated that the PE patients, relative to levels in control group and the healthy control subjects, had decreased circulating levels of T_reg cells/increased T_H17 cells; tissues from these patients also had relatively-decreased FoxP3 mRNA and protein expressions and elevated RORc mRNA and protein expressions. YY1 was expressed only at low levels in the PE patient placenta and endometrial tissues. In rats, PE rats treated with over-expressed YY1 had (relative to in PE rats without over-induced YY1) increased circulating levels of T_reg cells/decreased T_H17 cells; tissues from these rats had elevated FoxP3 mRNA and protein expressions and reduced mRNA and protein RORc expressions, as well as indications of alleviated inflammation. In the rat placenta samples, YY1 was also determined to activate the PI3K/AKT pathway. In summary, YY1 regulates the balance among T_reg/T_H17 cells and so affect the PE process in part through activation of the PI3K/AKT pathway.

Death receptor 3 is involved in preeclampsia through regulating placental trophoblast cell physiology by inactivating the PI3K/AKT pathway

BACKGROUND

Preeclampsia (PE) is a pregnancy related disease that affects about 5% of pregnancies. Death receptor 3 (DR3) expression is significantly elevated in both placental tissue and plasma of PE patients. However, whether DR3 was involved in trophoblasts in pathogenesis of PE are not well elucidated.

OBJECTIVE

Our research was designed to illustrate the biological roles of DR3 in placental trophoblasts, as well as explain its relevant mechanisms.

METHODS

HTR-8/SVneo cells viability, migration, invasion, and apoptosis were assessed using MTT, Transwell assay, and flow cytometry analysis, respectively. Levels of DR3, PI3K, and AKT in HTR-8/SVneo cells were analyzed via reverse transcription-quantitative polymerase chain reaction assay. Western blot analysis was utilized to assess DR3, p-PI3K, p-AKT, PI3K, and AKT protein expression.

RESULTS

Upregulation of DR3 obviously inhibited HTR-8/SVneo cells viability, migration, and invasion, as well as promoted HTR-8/SVneo cells apoptosis, as opposed to the control-plasmid group. We also found that DR3-plasmid enhanced cleaved-caspase3 expression, reduced p-PI3K and p-AKT protein expression, and p-PI3K/PI3K or p-AKT/AKT ratio in HTR-8/SVneo cells. Importantly, IGF-1, a PI3K/AKT signaling pathway agonist, partially reversed the effects of DR3-plasmid on the cell viability, migration, invasion, apoptosis, and PI3K/AKT signal pathway in HTR-8/SVneo cells.

CONCLUSION

DR3 was involved in PE through regulating placental trophoblast cell physiology via PI3K/AKT pathway, which might be a promising therapeutic target for PE therapy.

Progesterone Enhances the Invasion of Trophoblast Cells by Activating PI3K/AKT Signaling Pathway to Prevent Preeclampsia

We aimed to explore whether the effect of progesterone on preeclampsia via the PI3K/AKT signaling pathway. First, we studied the role of progesterone in preeclampsia patients and HTR-8/Svneo cells by adding progesterone. Then PI3K inhibitor LY294002 was added. The effects of progesterone on preeclampsia were also studied in animals by constructing a preeclampsia rat model. CCK-8 and Transwell assay were applied to measure cell viability and invasion ability. ELISA was performed to measure progesterone, MMP-2, MMP-9, pro-inflammatory factors TNF-α, IL-1β, and anti-inflammatory factors IL-4, IL-10, and IL-13 levels. HE staining was used to detect the pathological changes in uterine spiral artery. Western blot was performed to detect Cyclin D1, PCNA, MMP-2, MMP-9, inflammatory factors TNF-α, IL-1β, IL-4, IL-10, IL-13, and PI3K/AKT signaling pathway related proteins AKT, p-AKT, PI3K, and p-PI3K expressions. Progesterone could reduce blood pressure and urine protein in pregnant women with preeclampsia. TNF-α and IL-1β levels were decreased, but IL-4, IL-10, IL-13, cyclin D1, and PCNA levels were increased in pregnant women with preeclampsia after using progesterone. After the use of progesterone, the symptoms of the PE model group were improved. Among them, the lumen of the placental uterine spiral artery was enlarged, and the fibrinoid necrosis of the uterine wall and acute atherosclerotic lesions were relieved. In addition, progesterone promoted HTR-8/Svneo cells proliferation and invasion. However, high expression of MMP-2, MMP-9, p-AKT, and p-PI3K in Normal and preeclampsia groups caused by progesterone was weakened after adding LY294002, indicating that progesterone could activate PI3K/AKT signaling pathway to regulate HTR-8/Svneo cells. Progesterone decreased urine protein and blood pressure of preeclampsia rats in a concentration-dependent manner. Moreover, progesterone activated the PI3K/AKT signaling pathway and inhibited the inflammatory response in preeclampsia rats.

[2 + 2]-Cycloaddition-derived cyclobutane natural products: structural diversity, sources, bioactivities, and biomimetic syntheses

This review summarizes the structural diversity, bioactivities, and biomimetic synthesis of [2 + 2]-type cyclobutane natural products, along with discussion of their biosynthesis, stereochemical analysis, racemic occurrence, and biomimetic synthesis.

Discovery of Novel PI3Kδ Inhibitors Based on the p110δ Crystal Structure

PI3Kδ is a key mediator of B-cell receptor signaling and plays an important role in the pathogenesis of certain hematological malignancies, such as chronic lymphocytic leukemia. Idelalisib, which targets PI3Kδ specifically, is the first approved PI3K inhibitor for cancer therapy. Recently, we carried out virtual screening, cell-based assays, adapta kinase assays, and molecular dynamic analysis to discover novel PI3Kδ inhibitors and identified NSC348884 as a lead PI3Kδ inhibitor. NSC348884 had an excellent docking score, potent PI3Kδ-inhibitory activity, antitumor effects on various cancer cell lines, and a favorable binding mode with the active site of PI3Kδ. Moreover, through the structural modification of NSC348884, we further discovered comp#1, which forms H-bonds with both Val828 and Lys779 in the ATP binding pocket of PI3Kδ, with a more favorable conformation binding to PI3Kδ. In addition, we found that N¹, N¹, N²-trimethyl-N²-((6-methyl-1H-benzo[d]imidazol-2-yl) methyl) ethane-1,2-diamine might be a potential scaffold structure. Thus, the result of this study provides a far more efficient approach for discovering novel inhibitors targeting PI3Kδ.

New Potential Agents for Malignant Melanoma Treatment-Most Recent Studies 2020-2022

Malignant melanoma (MM) is the most lethal skin cancer. Despite a 4% reduction in mortality over the past few years, an increasing number of new diagnosed cases appear each year. Long-term therapy and the development of resistance to the drugs used drive the search for more and more new agents with anti-melanoma activity. This review focuses on the most recent synthesized anti-melanoma agents from 2020-2022. For selected agents, apart from the analysis of biological activity, the structure-activity relationship (SAR) is also discussed. To the best of our knowledge, the following literature review delivers the latest achievements in the field of new anti-melanoma agents.

Synthesis of cinnamic acid ester derivatives with antiproliferative and antimetastatic activities on murine melanoma cells

Melanoma is the most aggressive skin cancer, and its incidence has continued to rise during the past decades. Conventional treatments present severe side effects in cancer patients, and melanoma can be refractory to commonly used anticancer drugs, which justify the efforts to find new potential anti-melanoma drugs. An alternative to promote the discovery of new pharmacological substances would be modifying chemical groups from a bioactive compound. Here we describe the synthesis of seventeen compounds derived from cinnamic acid and their bioactivity evaluation against melanoma cells. The compound phenyl 2,3-dibromo-3-phenylpropanoate (3q) was the most effective against murine B16-F10 cells, as observed in cytotoxicity and cell migration assays. Simultaneously, this compound showed low cytotoxic activity on non-tumor cells. At the highest concentration, the compound 3q was able to trigger apoptosis, whereas, at lower concentrations, it affected the cell cycle and melanoma cell proliferation. Furthermore, cinnamate 3q impaired cell invasion, adhesion, colonization, and actin polymerization. In conclusion, these results highlight the antiproliferative and antimetastatic potential of cinnamic acid derivatives on melanoma.

Upregulation of REV7 correlates with progression of malignant melanoma

REV7 is a multifunctional protein implicated in DNA damage tolerance, cell cycle control, and gene expression, and is involved in the carcinogenesis of various human tumors. It has been reported that REV7 expression is associated with ultraviolet-induced mutagenesis; however, the role of REV7 expression in skin cancers, including malignant melanomas, remains unclear. In the present study, we investigated the clinical and biological significance of REV7 in malignant melanoma. Levels of REV7 expression in human skin cancers were evaluated immunohistochemically. Positive expression of REV7 was frequently observed in malignant melanomas, as well as in squamous cell carcinomas and basal cell carcinomas. Enhanced immunoreactivity to REV7 was closely linked with cell proliferation assessed by Ki-67 labeling indexes in the three skin cancers, and was related with tumor thickness in malignant melanomas. REV7 depletion in malignant melanoma cells MEWO and G361 suppressed cell proliferation, migration, and invasion abilities. REV7 depletion also affected the expression of intracellular signaling molecules AKT and ERK in MEWO cells, resulting in downregulation of ERK signal activation. In addition, REV7 depletion facilitated sensitivity to cisplatin, but not to dacarbazine, in MEWO cells. Our results suggest that REV7 expression correlates with disease progression of malignant melanoma.

Palmitic acid inhibits prostate cancer cell proliferation and metastasis by suppressing the PI3K/Akt pathway

AIMS

Prostate cancer is one of the most frequent causes of cancer death in men worldwide, and novel drugs for prostate cancer therapies are still being developed. Palmitic acid is a common saturated long-chain fatty acid that is known to exhibit anti-inflammatory and metabolic regulatory effects and antitumor activities in several types of tumors. The present study aims to explore the antiproliferative and antimetastatic activities of palmitic acid on human prostate cancer cells and the underlying mechanism.

MAIN METHODS

MTT and colony formation assays were utilized to determine the antiproliferative effect of palmitic acid. Cell metastasis was evaluated by wound healing, Transwell migration and invasion assay. The in vivo anticancer effect was assessed by a nude mouse xenograft model of prostate cancer. The involved molecular mechanisms were investigated by flow cytometry and Western blot analysis.

KEY FINDINGS

Palmitic acid significantly suppressed prostate cancer cell growth in vitro and in vivo. Treatment with palmitic acid induced G1 phase arrest, which was associated with downregulation of cyclin D1 and p-Rb and upregulation of p27. In addition, palmitic acid could inhibit prostate cancer cell metastasis, in which suppression of PKCζ and p-Integrinβ1 and an increase in E-cadherin expression might be involved. Furthermore, a mechanistic study indicated that palmitic acid inhibited the key molecules of the PI3K/Akt pathway to block prostate cancer proliferation and metastasis.

SIGNIFICANCE

Our findings suggested the antitumor potential of palmitic acid for prostate cancer by targeting the PI3K/Akt pathway.

TBC1 domain family member 23 interacts with Ras-related protein Rab-11A to promote poor prognosis of non-small-cell lung cancer via β1-integrin

Non‐small‐cell lung cancer (NSCLC) accounts for approximately 80% of lung cancer cases. TBC1D23, a member of the TBC/RABGAP family, is widely expressed in human tissues; however, its role in NSCLC is currently unknown. Immunohistochemical analysis was conducted on 173 paraffin‐embedded lung tissue sections from patients with NSCLC from 2014 to 2018 at the First Affiliated Hospital of China Medical University. MTT, colony formation assay, cell cycle assay, scratch assay, transwell assay, Western blotting and real‐time PCR were employed on multiple NSCLC cell lines modified to knock down or overexpress TBC1D23/RAB11A. Immunoprecipitation, immunoprecipitation‐mass spectrometry, immunofluorescence and flow cytometry were performed to explore the interaction between TBC1D23 and RAB11A and TBC1D23 involvement in the interaction between RAB11A and β1 integrin in the para‐nucleus. TBC1D23 was correlated with tumour size, differentiation degree, metastasis, TNM stage and poor prognosis. TBC1D23 was involved in the interaction between RAB11A and β1 integrin in the para‐nucleus, thus activating the β1 integrin/FAK/ERK signalling pathway to promote NSCLC. Furthermore, TBC1D23 promoted NSCLC progression by inducing cell proliferation, migration and invasion. This study indicated the relationship between TBC1D23 expression and the adverse clinicopathological characteristics of patients with NSCLC, suggesting that TBC1D23 may be an important target for NSCLC treatment.

Targeting c-Jun in A549 Cancer Cells Exhibits Antiangiogenic Activity In Vitro and In Vivo Through Exosome/miRNA-494-3p/PTEN Signal Pathway

The oncogene c-Jun is activated by Jun N-terminal kinase (JNK). Exosomes are nanometer-sized membrane vesicles released from a variety of cell types, and are essential for cell-to-cell communication. By using specific JNK inhibitor SP600125 or CRISPR/Cas9 to delete c-Jun, we found that exosomes from SP600125-treated A549 cancer cells (Exo-SP) or from c-Jun-KO-A549 cells (Exo-c-Jun-KO) dramatically inhibited tube formation of HUVECs. And the miR-494 levels in SP600125 treated or c-Jun-KO A549 cells, Exo-SP or Exo-c-Jun-KO, and HUVECs treated with Exo-SP or Exo-c-Jun-KO were significantly decreased. Meanwhile, Exo-SP and Exo-c-Jun-KO enhanced expression of phosphatase and tensin homolog deleted on chromosome ten (PTEN). Addition of miR-494 agomir in Exo-c-Jun-KO treated HUVECs inhibited PTEN expression and promoted tube formation, suggesting the target of miR-494 might be PTEN in HUVECs. Moreover, A549 tumor xenograft model and Matrigel plug assay demonstrated that Exo-c-Jun-KO attenuated tumor growth and angiogenesis through reducing miR-494. Taken together, inhibition of c-Jun in A549 cancer cells exhibited antiangiogenic activity in vitro and in vivo through exosome/miRNA-494-3p/PTEN signal pathway.

In Vitro Comparison of the Anti-Proliferative Effects of Galenia africana on Human Skin Cell Lines

Malignant melanoma is the major cause of skin cancer-related deaths. Surgery in combination with radiotherapy, immunotherapy or chemotherapy is used to eradicate cancer cells, however, this treatment option is limited by the tolerance of the surrounding healthy tissue. The extracts from Galenia africana have been shown to possess anti-cancer flavonoid compounds and can be a safer and cost-effective alternative treatment. The study aimed to compare the anti-proliferative effects of G. africana on human skin cells (HaCaT) and human malignant melanoma cells (A375). The cells were exposed to various concentrations of the G. africana extract at different times. In vitro assays were employed to determine cell viability and cytotoxicity. Hoechst 33342 staining was performed to observe the nuclear changes, including apoptosis. G. africana significantly reduced the cell viability of the A375 cells in a dose and time-dependent manner, while having no effect on the HaCaT cells. The A375 cells displayed nuclear condensation, brightly stained nuclei and nuclear fragmentation indicative of apoptosis. This suggests a clinical rationale for the use of G. africana as a potential anti-melanoma agent offering efficacy and low toxicity. This study provides new insights for future work on investigating the utilization of G. africana in malignant melanoma treatment.

Alternative Options for Skin Cancer Therapy via Regulation of AKT and Related Signaling Pathways

Global environmental pollution has led to human exposure to ultraviolet (UV) radiation due to the damaged ozone layer, thereby increasing the incidence and death rate of skin cancer including both melanoma and non-melanoma. Overexpression and activation of V-akt murine thymoma viral oncogene homolog (AKT, also known as protein kinase B) and related signaling pathways are major factors contributing to many cancers including lung cancer, esophageal squamous cell carcinoma and skin cancer. Although BRAF inhibitors are used to treat melanoma, further options are needed due to treatment resistance and poor efficacy. Depletion of AKT expression and activation, and related signaling cascades by its inhibitors, decreases the growth of skin cancer and metastasis. Here we have focused the effects of AKT and related signaling (PI3K/AKT/mTOR) pathways by regulators derived from plants and suggest the need for efficient treatment in skin cancer therapy.

An update on the implications of cyclin D1 in melanomas

Cyclin D1 is a protein encoded by the CCND1 gene, located on 11q13 chromosome, which is a key component of the physiological regulation of the cell cycle. CCND1/cyclin D1 is upregulated in several types of human tumors including melanoma and is currently classified as an oncogene that promotes uncontrolled cell proliferation. Despite the demonstrated importance of CCND1/cyclin D1 as a central oncogene in several types of human tumors, its knowledge in melanoma is still limited. This review examines data published on upregulation of the CCND1 gene and cyclin D1 protein in the melanoma setting, focusing on the pathways and molecular mechanisms involved in the activation of the gene and on the clinical and therapeutic implications.

Digoxin Enhances the Anticancer Effect on Non-Small Cell Lung Cancer While Reducing the Cardiotoxicity of Adriamycin

Digoxin is widely used to treat heart failure. Epidemiological studies suggested it might be used as an anticancer drug or sensitizing agent for cancer therapy. Adriamycin is a well-known anticancer drug, but often causes cardiotoxicity which limits its use. We recently investigated the anticancer effects of digoxin alone or in combination with adriamycin on human non-small cell lung cancer in vitro and in vivo. Digoxin reduced the viability of A549 and H1299 cells in vitro, increased DNA damage by promoting ROS generation and inhibiting both DNA double strand break (DSB) and single strand break (SSB) repair. Combination with adriamycin showed synergistic antiproliferative effects at the ratios of 1/2IC50_DIG:IC50_ADR and IC50_DIG:IC50_ADR on A549 and H1299 cells, respectively. In vivo, digoxin potently inhibited A549 growth in both zebrafish and nude mouse xenograft model. Co-treatment with adriamycin not only enhanced the antitumor efficacy, but also reduced the cardiotoxicity. Our findings suggest that digoxin has the potential to be applied as an antitumor drug via inhibiting both DNA DSB and SSB repair, and combination with adriamycin for therapy of human non-small cell lung cancer is reasonable.

On the planarity of the cyclobutane ring in the crystal of dimethyl 2,4-bis(3,4-dimethoxyphenyl)cyclobutane-1,3-dicarboxylate: a natural bond orbital and Hirshfeld surface analysis study

The α-form of this 1,3-di-(substituted)-2,4-bis-(substituted)-cyclobutane derivative displays a planar ring in the gas phase and solution. The intermolecular interactions in the crystal have been determined.

Atorvastatin Exerts Antileukemia Activity via Inhibiting Mevalonate-YAP Axis in K562 and HL60 Cells

Novel therapeutic strategies are still urgently expected for leukemia despite undisputed success of various targeted therapeutics. The antileukemia activity of Atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, on human leukemia cells was investigated. Atorvastatin inhibited K562 and HL60 cell proliferation, induced G2/M cell cycle arrest in K562 cells by down-regulating cyclinB1 and cdc2, but G0/G1 arrest in HL60 cells by up-regulating p27 and down-regulating cyclinD1 and p-pRb. Atorvastatin also induced apoptosis in both cell lines, in which the reactive oxygen species (ROS)-related mitochondrial apoptotic signaling might be involved, with increase of ROS and Bax/Bcl-2 ratio, loss of mitochondrial membrane potential (MMP), release of cytochrome C into cytosol, and activation of Bax/Caspase-9/Caspase-3/PARP pathway. Inhibition of YAP nuclear localization and activation by Atorvastatin was reversed by the addition of mevalonate, GGPP, or FPP. Further, the effects on cell cycle arrest- and apoptosis- related proteins by Atorvastatin were alleviated by addition of mevalonate, suggesting the antileukemia effect of Atorvastatin might be through mevalonate-YAP axis in K562 and HL60 cells. Our results suggest that Atorvastatin might be used for leukemia therapy while evidence of clinical efficacy is required.

Quinalizarin induces cycle arrest and apoptosis via reactive oxygen species-mediated signaling pathways in human melanoma A375 cells

Quinalizarin, a bioactive and highly selective compound, is known to promote apoptosis in colon and lung cancer cells. However, studies evaluating quinalizarin-induced apoptosis in melanoma cells have not been conducted. In the present study, we investigated the underlying mechanisms of antimelanoma activity of quinalizarin in human melanoma A375 cells. The MTT assay and Trypan blue staining were used to evaluate the cell viability. The flow cytometry was used to detect cell cycle, apoptosis and reactive oxygen species (ROS). Western blot was used to detect the expression of cell cycle and apoptosis-related proteins, MAPK, and STAT3. The results revealed a significant dose and time dependent effect of quinalizarin on inhibiting proliferation in three kinds of human melanoma cells, and had no significant toxic effects on normal cells. Moreover, quinalizarin triggered G2/M phase cell arrest by modulating the protein expression levels of CDK 1/2, cyclin A, cyclin B, p21 and p27, and induced apoptosis by down-regulating the antiapoptotic protein Bcl-2 and upregulating the proapoptotic protein BAD, leading to the activation of caspase-3 and PARP in the caspase cascade in A375 cells. Quinalizarin treatment led to apoptosis of A375 cells via activation of MAPK and inhibition of STAT3 signaling pathways. In addition, quinalizarin increased the level of ROS, but ROS scavenger NAC inhibited quinalizarin-induced apoptosis by regulating MAPK and STAT3 signaling pathways. In summary, quinalizarin induces cell cycle arrest and apoptosis via ROS-mediated MAPK and STAT3 signaling pathways in human melanoma A375 cells, and quinalizarin may be used as a novel and effective antimelanoma therapeutic.

Cadmium induces A549 cell migration and invasion by activating ERK

Cadmium (Cd) is an established carcinogen that is involved in the progression of lung cancer. However, the mechanisms underlying this Cd-induced process have yet to be fully elucidated. The present study explored the potential roles of phosphorylated (p)-ERK in the Cd-induced migration and invasion of lung cancer cells. An MTT assay was performed to evaluate cell viability whilst western blot analysis and reverse transcription-quantitative PCR were used to detect the expression of protein and mRNA, respectively. Migration and invasion assays were performed to assess cell migratory and invasive abilities. The results demonstrated that exposure to Cd increased the expression of p-ERK in A549 cells. Cd also enhanced the migration and invasion of A549 cells, which could be blocked via U0126 treatment (an inhibitor of mitogen activated protein kinase). In addition, it was identified that Cd-induced expression of matrix metalloproteinases 2 mRNA was mediated by p-ERK. In conclusion, the present findings indicated that Cd induced A549 cell migration and invasion by activating ERK, and it was hypothesized that p-ERK could serve as a target in the clinical treatment of Cd-induced lung cancer.

ANXA4 promotes trophoblast invasion via the PI3K/Akt/eNOS pathway in preeclampsia

The inadequate trophoblast invasion is associated with the development of preeclampsia (PE). Considering that annexin A4 (ANXA4) enhances tumor invasion, we aimed to explore the functional role of ANXA4 in trophoblast cells and to examine the underlying mechanism. ANXA4 expression in PE placentas was analyzed using immunohistochemistry and Western blotting. Cell proliferation, invasion, and apoptosis were determined using a MTT assay, Transwell assay, and flow cytometry, respectively. The expression levels of matrix metalloproteinase (MMP)-2, MMP-9, phosphoinositide 3-kinase (PI3K), Akt, phosphorylated (p)-Akt, and phosphorylated endothelial nitric oxide synthase (p-eNOS) were detected by Western blotting. Placentas were prepared for pathological examination using hematoxylin and eosin staining and apoptosis determination using the TUNEL method. Expression of ANXA4, PI3K, p-Akt and p-eNOS was downregulated in human PE placentas and PE placenta-derived extravillous cytotrophoblasts (EVCTs). Furthermore, ANXA4 overexpression promoted cell proliferation and invasion, inhibited cell apoptosis, and upregulated protein expression of PI3K, p-Akt, and p-eNOS in human trophoblast cells HTR-8/SVneo and JEG-3. By contrast, ANXA4 knockdown exerted the opposite effects. Furthermore, inhibition of the PI3K/Akt pathway by LY294002 abrogated the ANXA4 overexpression-mediated effects on trophoblast behavior. Furthermore, eNOS knockdown abrogated the ANXA4 overexpression-induced promotion of cell invasion and MMP2/9 expression. Additionally, in N-nitro-l-arginine methyl ester (l-NAME)-induced PE rats, ANXA4 overexpression alleviated PE progression, accompanied by an increase in expression of PI3K, p-Akt, and p-eNOS in rat placentas. Our findings demonstrate that ANXA4 expression is downregulated in PE. ANXA4 may promote trophoblast invasion via the PI3K/Akt/eNOS pathway.

Flavonoids as key bioactive components of Oxytropis falcata bunge, a traditional anti-inflammatory and analgesic Tibetan medicine

The traditional Tibetan medicine Oxytropis falcata Bunge, in the Leguminosae family, is widely used in the west area owing to its significant anti-inflammatory and analgesic activities. O. falcata is rich in flavonoids, which are the main secondary metabolites and key bioactive components of this plant. Up to now, 91 flavonoids have been isolated from O. falcata, including isoflavone, flavone, flavonone, flavonol, homoisoflavonoid, chalcone, dihydrochalcone, chalcone dimers, and pterocarpans. The flavonoids in O. falcata have good anti-inflammatory and analgesic activities, which are comparable to those of a positive drug control (indomethacin). Furthermore, these flavonoids exhibit antibacterial, antioxidant, antitumour, anti-cardiovascular disease, and haemostatic activities. However, to date, O. falcata has not been reviewed comprehensively. Herein, the main secondary metabolites, biosynthetic pathways, and bioactivities of O. falcata are discussed.

Sphingosine 1-phosphate promotes mesenchymal stem cell-mediated cardioprotection against myocardial infarction via ERK1/2-MMP-9 and Akt signaling axis

AIMS

The sphingolipid metabolite sphingosine 1‑phosphate (S1P) has emerged as a potential cardioprotective molecule against ischemic heart disease. Moreover, S1P triggers mobilization and homing of bone marrow-derived stem/progenitor cells into the damaged heart. However, it remains elusive whether S1P promotes mesenchymal stem cells (MSCs)-mediated cardioprotection against ischemic heart diseases.

MAIN METHODS

Adipose tissue-derived MSCs (AT-MSCs) were obtained from GFP transgenic mice or C57BL/6J. Myocardial infarction (MI) was induced in C57BL/6J mice by ligation of the left anterior descending coronary artery (LAD). Subsequently, S1P-treated AT-MSCs or vehicle-treated AT-MSCs were intravenously administered for 24 h after induction of MI or sham procedure.

KEY FINDINGS

Pre-conditioning with S1P significantly enhanced the migratory and anti-apoptotic efficacies of AT-MSCs. In MI-induced mice, intravenous administration of S1P-treated AT-MSCs significantly augmented their homing and engraftment in ischemic area. Besides, AT-MSCs with S1P pre-treatment exhibited enhanced potencies to inhibit cardiomyocyte apoptosis and fibrosis, and stimulate angiogenesis and preserve cardiac function. Mechanistic studies revealed that S1P promoted AT-MSCs migration through activation of ERK1/2-MMP-9, and protected AT-MSCs against apoptosis via Akt activation. Further, S1P activated the ERK1/2 and Akt via S1P receptor 2 (S1PR2), but not through S1PR1. S1PR2 knockdown by siRNA, however, significantly attenuated S1P-mediated AT-MSCs migration and anti-apoptosis.

SIGNIFICANCE

The findings of the present study revealed the protective efficacies of S1P pretreatment on the survival/retention and cardioprotection of engrafted MSCs. Pre-conditioning of donor MSCs with S1P is an effective strategy to promote the therapeutic potential of MSCs for ischemic heart diseases.