Anticancer effects of tanshinone I in human non-small cell lung cancer

The role of tumor-associated macrophages in lung cancer: From mechanism to small molecule therapy

Tumor-associated macrophages (TAMs) are the main component of tumor-infiltrating immune cells in the lung tumor microenvironment. TAMs recruited to the lung cancer can create a suitable microenvironment for the growth and metastasis of lung cancer by secreting tumor promoting factors and interfering with the function of T cells. Currently, numerous studies have reported that small molecular drugs affect lung cancer progression by selectively targeting TAMs. The main ways include blocking the recruitment of monocytes or eliminating existing TAMs in tumor tissue, reprogramming TAMs into pro-inflammatory M1 macrophages or inhibiting M2 polarization of macrophages, interrupting the interaction between tumor cells and macrophages, and modulating immune function. Signaling pathways or cytokines such as CCL8, CCL2/CCR2, CSF-1/CSF-1R, STAT3, STAT6, MMPs, Caspase-8, AMPK α1, TLR3, CD47/SIRPα, have been reported to be involved in this process. Based on summarizing the role and mechanisms of TAMs in lung cancer progression, this paper particularly focuses on systematically reviewing the effects and mechanisms of small molecule drugs on lung cancer TAMs, and classified the small molecular drugs according to the way they affect TAMs. The study aims to provide new perspectives and potential therapeutic drugs for targeted macrophages treatment in lung cancer, which is of great significance and will provide more options for immunotherapy of lung cancer.

Cytotoxic diterpenoids from Salvia glutinosa and comparison with the tanshinone profile of danshen (Salvia miltiorrhiza)

The roots of Salvia miltiorrhiza are the source of the traditional Chinese medicine danshen and the class of tanshinones, particular quinoid nor-diterpenoids of the abietane type. Of these compounds, cryptotanshinone, dihydrotanshinone I, tanshinone I, and tanshinone IIA, have been extensively studied for their anticancer potential, not only but as well because of their high abundance in S. miltiorrhiza and their thus easy availability. However, also additional Salvia species are known to contain tanshinones, mainly such of the subgenus Glutinaria, of which S. glutinosa is the only species widely occurring in Europe. Using UHPLC-DAD-MS, the tanshinone profile of S. glutinosa roots collected from two different locations was compared to the profile in S. miltiorrhiza roots. In addition, tanshinone IIA and another six diterpenoids from S. glutinosa were investigated for their antiproliferative and cytotoxic potential against MDA-MB-231 and HL-60 cells. Apart from dihydrotanshinone I, which has been previously characterized due to its anticancer properties, we determined danshenol A as a highly antiproliferative and cytotoxic agent, significantly surpassing the effects of dihydrotanshinone I. With regard to the diterpenoid profile, S. miltiorrhiza showed a higher concentration for most of the tanshinones, except for (+)-danshexinkun A, which was present in comparable amounts in both species. Danshenol A, in contrast, was only present in S. glutinosa as were dehydroabietic acid and (+)-pisiferic acid. The results of our study underlines the long traditional use of danshen due to its high amount on tanshinones, but also demonstrates the potential value of investigating closely related species for the discovery of new biologically active lead compounds.

Natural Compounds of Salvia L. Genus and Molecular Mechanism of Their Biological Activity

The study of medicinal plants is important, as they are the natural reserve of potent biologically active compounds. With wide use in traditional medicine and the inclusion of several species (as parts and as a whole plant) in pharmacopeia, species from the genus Salvia L. are known for the broad spectrum of their biological activities. Studies suggest that these plants possess antioxidant, anti-inflammatory, antinociceptive, anticancer, antimicrobial, antidiabetic, antiangiogenic, hepatoprotective, cognitive and memory-enhancing effects. Phenolic acids, terpenoids and flavonoids are important phytochemicals, which are primarily responsible for the medicinal activity of Salvia L. This review collects and summarizes currently available data on the pharmacological properties of sage, outlining its principal physiologically active components, and it explores the molecular mechanism of their biological activity. Particular attention was given to the species commonly found in Kazakhstan, especially to Salvia trautvetteri Regel, which is native to this country.

Salviae miltiorrhiza against human lung cancer: A review of its mechanism (Review)

Lung cancer is one of the commonest malignant tumors in the world today, causing millions of mortalities every year. New methods to treat lung cancer are urgently needed. Salviae miltiorrhiza Bunge is a common Chinese medicine, often used for promoting blood circulation. In the past 20 years, Salviae miltiorrhiza has made significant progress in the treatment of lung cancer and is considered to be one of the most promising methods to fight against the disease. A great amount of research has shown that the mechanism of Salviae miltiorrhiza against human lung cancer mainly includes inhibiting the proliferation of lung cancer cells, promoting lung cancer cell apoptosis, inducing cell autophagy, regulating immunity and resisting angiogenesis. Research has shown that Salviae miltiorrhiza has certain effects on the resistance to chemotherapy drugs. The present review discussed the status and prospects of Salviae miltiorrhiza against human lung cancer.

PLA2G2A Phospholipase Promotes Fatty Acid Synthesis and Energy Metabolism in Pancreatic Cancer Cells with K-ras Mutation

Oncogenic K-ras is often activated in pancreatic ductal adenocarcinoma (PDAC) due to frequent mutation (>90%), which drives multiple cellular processes, including alterations in lipid metabolism associated with a malignant phenotype. However, the role and mechanism of the altered lipid metabolism in K-ras-driven cancer remains poorly understood. In this study, using human pancreatic epithelial cells harboring inducible K-rasG12D (HPNE/K-rasG12D) and pancreatic cancer cell lines, we found that the expression of phospholipase A2 group IIA (PLA2G2A) was upregulated by oncogenic K-ras. The elevated expression of PLA2G2A was also observed in pancreatic cancer tissues and was correlated with poor survival of PDAC patients. Abrogation of PLA2G2A by siRNA or by pharmacological inhibition using tanshinone I significantly increased lipid peroxidation, reduced fatty acid synthase (FASN) expression, and impaired mitochondrial function manifested by a decrease in mitochondrial transmembrane potential and a reduction in ATP production, leading to the inhibition of cancer cell proliferation. Our study suggests that high expression of PLA2G2A induced by oncogenic K-ras promotes cancer cell survival, likely by reducing lipid peroxidation through its ability to facilitate the removal of polyunsaturated fatty acids from lipid membranes by enhancing the de novo fatty acid synthesis and energy metabolism to support cancer cell proliferation. As such, PLA2G2A might function as a downstream mediator of K-ras and could be a potential therapeutic target.

Anticancer potential of cryptotanshinone on breast cancer treatment; A narrative review

Breast cancer has recently been known as the first lethal malignancy in women worldwide. Despite the existing treatments that have improved the patients’ prognosis, some types of breast cancer are serious challenges to treat. Therefore, efforts are underway to provide more efficient therapy. Cryptotanshinone (CPT) is a liposoluble diterpenoid derivation of a traditional Chinese herbal medicine called Salvia miltiorrhiza Bunge. It has been considered in the past decades due to its vast therapeutic properties, including anti-tumor, anti-inflammatory, and anti-fibrosis. Recently, studies have found that CPT showed a significant anti-breast cancer effect in vivo and in vitro through different physiological and immunological mechanisms. This study summarized the latest research findings on the antitumor effect of CPT in breast cancer. Further, the main molecular mechanisms based on breast cancer types and combination with other drugs were reviewed to provide essential evidence for future longitudinal research and its clinical application in breast cancer treatment.

Research and Development of Natural Product Tanshinone I: Pharmacology, Total Synthesis, and Structure Modifications

Salvia miltiorrhiza (S. miltiorrhiza), which has been used for thousands of years to treat cardiovascular diseases, is a well-known Chinese medicinal plant. The fat-soluble tanshinones in S. miltiorrhiza are important biologically active ingredients including tanshinone I, tanshinone IIA, dihydrotanshinone, and cryptotanshinone. Tanshinone I, a natural diterpenoid quinone compound widely used in traditional Chinese medicine, has a wide range of biological effects including anti-cancer, antioxidant, neuroprotective, and anti-inflammatory activities. To further improve its potency, water solubility, and bioavailability, tanshinone I can be used as a platform for drug discovery to generate high-quality drug candidates with unique targets and enhanced drug properties. Numerous derivatives of tanshinone I have been developed and have contributed to major advances in the identification of new drugs to treat human cancers and other diseases and in the study of related molecular mechanisms. This review focuses on the structural modification, total synthesis, and pharmacology of tanshinone I. We hope that this review will help understanding the research progress in this field and provide constructive suggestions for further research on tanshinone I.

Natural compounds: A new perspective on targeting polarization and infiltration of tumor-associated macrophages in lung cancer

With the development in tumor immunology, people are gradually understanding the complexity and diversity of the tumor microenvironment immune status and its important effect on tumors. Tumor-associated macrophages (TAMs), an important part of the tumor immune microenvironment, have a double effect on tumor growth and metastasis. Many studies have focused on lung cancer, especially non-small cell lung cancer and other "hot tumors" with typical inflammatory characteristics. The polarization and infiltration of TAMs is an important mechanism in the occurrence and development of malignant tumors, such as lung cancer, and in the tumor immune microenvironment. Therapeutic drugs designed for these reasons are key to targeting TAMs in the treatment of lung cancer. A large number of reports have suggested that natural compounds have a strong potential of affecting immunity by targeting the polarization and infiltration of TAMs to improve the immune microenvironment of lung cancer and exert a natural antitumor effect. This paper discusses the infiltration and polarization effects of natural compounds on lung cancer TAMs, provides a detailed classification and systematic review of natural compounds, and summarizes the bias of different kinds of natural compounds by affecting their antitumor mechanism of TAMs, with the aim of providing new perspectives and potential therapeutic drugs for targeted macrophages in the treatment of lung cancer.

Role of Plant-Derived Active Constituents in Cancer Treatment and Their Mechanisms of Action

Despite significant technological advancements in conventional therapies, cancer remains one of the main causes of death worldwide. Although substantial progress has been made in the control and treatment of cancer, several limitations still exist, and there is scope for further advancements. Several adverse effects are associated with modern chemotherapy that hinder cancer treatment and lead to other critical disorders. Since ancient times, plant-based medicines have been employed in clinical practice and have yielded good results with few side effects. The modern research system and advanced screening techniques for plants’ bioactive constituents have enabled phytochemical discovery for the prevention and treatment of challenging diseases such as cancer. Phytochemicals such as vincristine, vinblastine, paclitaxel, curcumin, colchicine, and lycopene have shown promising anticancer effects. Discovery of more plant-derived bioactive compounds should be encouraged via the exploitation of advanced and innovative research techniques, to prevent and treat advanced-stage cancers without causing significant adverse effects. This review highlights numerous plant-derived bioactive molecules that have shown potential as anticancer agents and their probable mechanisms of action and provides an overview of in vitro, in vivo and clinical trial studies on anticancer phytochemicals.

Medicinal Plants in Cancer Treatment: Contribution of Nuclear Factor-Kappa B (NF-kB) Inhibitors

Nuclear factor-kappa B (NF-κB) is one of the principal inducible proteins that is a predominant transcription factor known to control the gene expression in mammals and plays a pivotal role in regulating cell signalling in the body under certain physiological and pathological conditions. In cancer cells, such as colon, breast, pancreatic, ovarian, melanoma, and lymphoma, the NF-κB pathway has been reported to be active. In cellular proliferation, promoting angiogenesis, invasion, metastasis of tumour cells and blocking apoptosis, the constitutive activity of NF-κB signalling has been reported. Therefore, immense attention has been given to developing drugs targeting NF-κB signalling pathways to treat many types of tumours. They are a desirable therapeutic target for drugs, and many studies concentrated on recognizing compounds. They may be able to reverse or standstill the growth and spread of tumours that selectively interfere with this pathway. Recently, numerous substances derived from plants have been evaluated as possible inhibitors of the NF-κB pathway. These include various compounds, such as flavonoids, lignans, diterpenes, sesquiterpenes, polyphenols, etc. A study supported by folk medicine demonstrated that plant-derived compounds could suppress NF-κB signalling. Taking this into account, the present review revealed the anticancer potential of naturally occurring compounds which have been verified both by inhibiting the NF-κB signalling and suppressing growth and spread of cancer and highlighting their mechanism of NF-κB inhibition.

Construction and Screening of Fractional Library of Salviae Miltiorrhizae Radix et Rhizoma for the Rapid Identification of Active Compounds against Prostate Cancer

Efficient screening of anticancer agents is in urgent need to develop new drugs that combat malignant tumors and drug resistance. In this study, a combined strategy composed by solvent partition and HPLC fractionation was developed to generate an herbal fraction library of Salviae Miltiorrhizae Radix et Rhizoma to quickly and efficiently screen anticancer agents. All library entries are directed into 96 well plates which are well mapped with HPLC chromatograms. The cell proliferation assay revealed seven active subfractions. Then, the major active ten peaks in these subfractions were prepared and isolated by semipreparative HPLC, and their inhibitory activities against prostate cancer cells were then tested at the same concentration level, leading to the identification of several active compounds. In addition, the structures of compounds arucadiol (2), 15,16-dihydrotanshinone I (4), methyl tanshinonate (5), cryptanshinone (7), 1,2-dihydrotanshinquinone I (9), and tanshinone IIA (10) were characterized by mass spectrometry and X-ray crystallographic analysis, and they were confirmed to be active in suppressing prostate cancer cell proliferation at 7.5 or 15 μg/mL, among which, the minor compounds 2, 4, and 5 showed higher activities than 9 and 10. This study provided a rapid strategy of identifying new anticancer agents in Salviae Miltiorrhizae Radix et Rhizoma, which can be applied in other herbal medicines.

Dihydroisotanshinone I induced ferroptosis and apoptosis of lung cancer cells

Danshen (Salvia miltiorrhiza Bunge) is broadly utilized in traditional Chinese medicine for lung cancer. However, it's exact effort and mechanism on lung cancer is fully unclear. In this study, we found that dihydroisotanshinone I (DT), a pure compound extracted from danshen, can inhibit the growth of A549 cells and H460 cells. DT also induced apoptosis and ferroptosis in these lung cancer cells. DT also blocking the protein expression of GPX4 (Glutathione peroxidase 4). For in vivo study, DT treatment can inhibit metastasis of A549 cells in the nude mice model without adverse effects on mice. In conclusion, DT inhibited the growth of lung cancer cells through apoptosis and ferroptosis and inhibited metastasis of A549 cells in the nude mice model. Further studies are warranted to validate the findings of this study.

HuR as Therapeutic Target in Cancer: What the Future Holds

ELAV-like protein 1, or HuR (human antigen R), is an RNA-binding protein encoded by the ELAVL1 gene in humans. One of its best functions is to stabilize mRNAs in order to regulate gene expression. HuR protein overexpression has undoubtedly been linked to an increased risk of tumor growth, progression, and metastasis, rendering it a potential therapeutic target candidate in cancer. Novel agents interfering with HuR expression have been tested, both in vitro and in vivo, with promising results. The aim of this paper is to review the existing literature regarding the potential agents that could actively act on and inhibit HuR expression. HuR molecule controls the expression of various proto-oncogenes, cytokines and growth factors, representing a major player in tumor progression, invasion, and metastasis and constituting an emerging target for cancer therapy. PubMed database was thoroughly searched, and all published articles providing scientific data on molecules that can exhibit antitumorigenic effects via HuR inhibition were included. According to these data, HuR inhibition should be a promising target in cancer therapeutics.

Tanshinones: An Update in the Medicinal Chemistry in Recent 5 Years

Tanshinones are an important type of natural products isolated from Salvia miltiorrhiza Bunge with various bioactivities. Tanshinone IIa, cryptotanshinone and tanshinone I are three kinds of tanshinones which have been widely investigated. Particularly, sodium tanshinone IIa sulfonate is a water-soluble derivative of tanshinone IIa and it is used in clinical in China for treating cardiovascular diseases. In recent years, there are increasing interests in the investigation of tanshinones derivatives in various diseases. This article presents a review of the anti-atherosclerotic effects, cardioprotective effects, anticancer activities, antibacterial activities and antiviral activities of tanshinones and structural modification work in recent years.

Effects of Salvia miltiorrhiza extract on lung adenocarcinoma

Lung adenocarcinoma is the most common subtype of non-small cell lung carcinoma. Tanshinone I is an important fat-soluble component in the extract of Salvia miltiorrhiza that has been reported to inhibit lung adenocarcinoma cell proliferation. However, no studies have clearly demonstrated changes in lung adenocarcinoma gene expression and signaling pathway enrichment following Tanshinone I treatment. And it remains unclear whether salvianolate has an effect on lung adenocarcinoma. The present study downloaded the GSE9315 dataset from the Gene Expression Omnibus database to identify differentially expressed genes (DEGs) and the underlying signaling pathways involved after Tanshinone I administration in the lung adenocarcinoma cell line CL1-5. The results revealed that there were 28 and 102 DEGs in the low dosage group (0.01 and 0.10 µg/ml Tanshinone I) and medium dosage groups (1 and 10 µg/ml Tanshinone I), respectively. In the low dosage group, DEGs were mainly enriched in ‘positive regulation of T-helper cell differentiation’ and ‘protein complex’. In the medium dosage group, 102 DEGs were enriched in ‘MAPK cascade’ and ‘extracellular exosome’. Kyoto Encyclopedia of Genes and Genomes pathway analysis demonstrated enrichment of both groups in the PI3K-Akt signaling pathway. Furthermore, there were nine overlapping DEGs [ADP ribosylation factor-interacting protein 2, chemokine (C-X-C motif) ligand 6, SH2 domain-containing adaptor protein B, Src homology 2 domain-containing transforming protein1, collagen type VI α1 chain, elastin, integrin subunit α, endoplasmic reticulum mannosyl-oligosaccharide 1,2-α-mannosidase and sterile α motif domain-containing 9 like] between the two groups, which serve to be potential targets for the treatment of lung adenocarcinoma. The present study also investigated the possible effects of salvianolate on lung adenocarcinoma in vivo using nude mouse xenograft models injected with the A549 cell line. The data revealed that salvianolate not only suppressed lung adenocarcinoma tumor growth of in nude mice, but also downregulated the expression levels of ATP7A and ATP7B, which are important proteins in the tumorigenesis and chemotherapy of lung adenocarcinoma. The present study provided evidence for the potential use of Salvia miltiorrhiza extract for treating lung adenocarcinomas in the clinic.

Chemoinformatic Screening for the Selection of Potential Senolytic Compounds from Natural Products

Cellular senescence is a cellular condition that involves significant changes in gene expression and the arrest of cell proliferation. Recently, it has been suggested in experimental models that the elimination of senescent cells with pharmacological methods delays, prevents, and improves multiple adverse outcomes related to age. In this sense, the so-called senoylitic compounds are a class of drugs that selectively eliminates senescent cells (SCs) and that could be used in order to delay such adverse outcomes. Interestingly, the first senolytic drug (navitoclax) was discovered by using chemoinformatic and network analyses. Thus, in the present study, we searched for novel senolytic compounds through the use of chemoinformatic tools (fingerprinting and network pharmacology) over different chemical databases (InflamNat and BIOFACQUIM) coming from natural products (NPs) that have proven to be quite remarkable for drug development. As a result of screening, we obtained three molecules (hinokitiol, preussomerin C, and tanshinone I) that could be considered senolytic compound candidates since they share similarities in structure with senolytic leads (tunicamycin, ginsenoside Rb1, ABT 737, rapamycin, navitoclax, timosaponin A-III, digoxin, roxithromycin, and azithromycin) and targets involved in senescence pathways with potential use in the treatment of age-related diseases.

Identification of two novel thiophene analogues as inducers of autophagy mediated cell death in breast cancer cells

Natural compounds isolated from different medicinal plants remain one of the major resources of anticancer drugs due to their enormous chemical diversity. Studies suggested therapeutic potential for various tanshinones, key bioactive lipophilic compounds from the root extracts of Salvia miltiorrhiza Bunge, against multiple cancers including breast carcinoma. We designed, synthesized and evaluated anti-cancer properties of a series of condensed and doubly condensed furophenanthraquinones of tanshinone derivatives on two breast cancer lines - MCF7 and MDA-MB-231. We identified two thiophene analogues - compounds 48 and 52 with greater anti-proliferative efficiency (~4 fold) as compared to the natural tanshinones. Mechanistically, we showed that both compounds induced autophagy mediated cell death and partial but significant restoration of cell death in the presence of autophagy inhibitor further supported this notion. Both compounds transcriptionally activated several autophagy genes responsible for autophagosome formation along with two death regulators - GADD34 and CHOP for inducing cell death. Altogether, our studies provide strong evidence to support compounds 48 and 52 as promising leads for further development as anticancer agents through modulating autophagy mechanism.

Tanshinone I regulates autophagic signaling via the activation of AMP-activated protein kinase in cancer cells

Tanshinone I, one of the components of Salvia miltiorrhiza Bunge, exhibits anti-tumor ability and induces autophagy. But the mechanisms are not fully understood. This study aims to investigate whether AMP-activated protein kinase dependent pathway is involved in the autophagic signaling regulation and its relationship with tumor suppression. Breast cancer cells (MDA-MB-231, MCF-7) and hepatocellular carcinoma cells (HepG2) were treated with Tanshinone I or vehicle. Acridine orange dyeing and transmission electron microscopy were employed to evaluate autophagic cells. MTT and Cell Counting Kit-8 assays were used to detect the effect of Tanshinone I combined with autophagy inhibitors on cell proliferation. Western blot was used to detect the expression levels of Beclin1 and LC3-I/II, as well as the phosphorylation of AMPKα and ULK1. Our results showed that Tanshinone I suppressed proliferation of HepG2, MDA-MB-231 and MCF-7 cancer cell lines. LC3-II and P62 were induced by Tanshinone I in all three cancer cell lines. But autophagic flux analysis showed that Tanshinone I treatment induced autophagy only in MDA-MB-231, which was also proved by transmission electron microscopy. Tanshinone I upregulated the phosphorylation of AMPKα and its downstream ULK1. AMP-activated protein kinase inhibitor compound C attenuated Beclin 1 and LC3-II expression induced by Tanshinone I in HepG2. In MDA-MB-231, compound C surprisingly induced LC3-II upregulation which is independent of AMPKα activation. Under this circumstance, treatment of Tanshinone I combined with compound C significantly inhibited MDA-MB-231 proliferation, compared with Tanshinone I treatment alone. This study demonstrates that Tanshinone I could induce cancer cell death and regulate autophagy signaling in breast cancer and hepatic carcinoma cells. Activation of AMPKα was found to be involved in autophagic signaling regulation by Tanshinone I.

Tanshinone I and simvastatin inhibit melanoma tumour cell growth by regulating poly (ADP ribose) polymerase 1 expression

Melanoma is one of the most aggressive forms of skin tumour with poor prognosis; no effective therapy has been established for melanoma at the metastatic stage. The present study aimed to investigate the role of poly (ADP ribose) polymerase (PARP) inhibitors (PARPis) and PARP1 expression in melanoma progression. In addition, whether high PARP1 expression was associated with poor overall survival in melanoma, and whether a combination effect existed between PARPis and other anti-tumour compounds (e.g., sunitinib) was analysed. The PARP1 expression was detected using western blot analysis and the proliferation of cells was detected with a colony formation assay. In addition, cell viability assays and xenograft tumor experiments were conducted. The results of the present study demonstrated that sunitinib reduced PARP1 expression and proliferation of melanoma cells. Notably, one of the PARPis, veliparib, reversed the inhibitory effect of sunitinib on PARP1 expression and proliferation, indicating that inhibition of PARP1 enzyme activity by PARPi may be different from the inhibition of PARP1 expression in melanoma cell biological function. To further confirm the relationship between PARP1 expression and tumour cell proliferation, seven compounds, including common approved drugs and natural Chinese medicine monomers, were screened, and the results demonstrated that simvastatin and tanshinone I exerted an inhibitory effect on PARP1 expression and melanoma cell proliferation, and their combination was more effective than simvastatin alone in vivo. The results indicated that simvastatin and tanshinone I inhibited melanoma and renal tumour cells by regulating PARP1 expression, and in addition to the enzyme activity of PARP1, the expression of PARP1 protein may serve a role in tumour progression.

The Anticancer Properties of Tanshinones and the Pharmacological Effects of Their Active Ingredients

Cancer is a common malignant disease worldwide with an increasing mortality in recent years. Salvia miltiorrhiza, a well-known traditional Chinese medicine, has been used for the treatment of cardiovascular and cerebrovascular diseases for thousands of years. The liposoluble tanshinones in S. miltiorrhiza are important bioactive components and mainly include tanshinone IIA, dihydrodanshinone, tanshinone I, and cryptotanshinone. Previous studies showed that these four tanshinones exhibited distinct inhibitory effects on tumor cells through different molecular mechanisms in vitro and in vivo. The mechanisms mainly include the inhibition of tumor cell growth, metastasis, invasion, and angiogenesis, apoptosis induction, cell autophagy, and antitumor immunity, and so on. In this review, we describe the latest progress on the antitumor functions and mechanisms of these four tanshinones to provide a deeper understanding of the efficacy. In addition, the important role of tumor immunology is also reviewed.

Tanshinone I attenuates the malignant biological properties of ovarian cancer by inducing apoptosis and autophagy via the inactivation of PI3K/AKT/mTOR pathway

Objectives

Tanshinone I (Tan‐I) is one of the vital fatsoluble monomer components, which extracted from Chinese medicinal herb Salvia miltiorrhiza Bunge. It has been shown that Tan‐I exhibited anti‐tumour activities on different types of cancers. However, the underlying mechanisms by which Tan‐Ⅰ regulates apoptosis and autophagy in ovarian cancer remain unclear. Thus, this study aimed to access the therapy effect of Tan‐Ⅰ and the underlying mechanisms.

Methods

Ovarian cancer cells A2780 and ID‐8 were treated with different concentrations of Tan‐Ⅰ (0, 1.2, 2.4, 4.8 and 9.6 μg/mL) for 24 hours. The cell proliferation was analysed by CCK8 assay, EdU staining and clone formation assay. Apoptosis was assessed by the TUNEL assay and flow cytometry. The protein levels of apoptosis protein (Caspase‐3), autophagy protein (Beclin1, ATG7, p62 and LC3II/LC3I) and PI3K/AKT/mTOR pathway were determined by Western blot. Autophagic vacuoles in cells were observed with LC3 dyeing using confocal fluorescent microscopy. Anti‐tumour activity of Tan‐Ⅰ was accessed by subcutaneous xeno‐transplanted tumour model of human ovarian cancer in nude mice. The Ki67, Caspase‐3 level and apoptosis level were analysed by immunohistochemistry and TUNEL staining.

Results

Tan‐Ⅰ inhibited the proliferation of ovarian cancer cells A2780 and ID‐8 in a dose‐dependent manner, based on CCK8 assay, EdU staining and clone formation assay. In additional, Tan‐Ⅰ induced cancer cell apoptosis and autophagy in a dose‐dependent manner in ovarian cancer cells by TUNEL assay, flow cytometry and Western blot. Tan‐Ⅰ significantly inhibited tumour growth by inducing cell apoptosis and autophagy. Mechanistically, Tan‐Ⅰ activated apoptosis‐associated protein Caspase‐3 cleavage to promote cell apoptosis and inhibited PI3K/AKT/mTOR pathway to induce autophagy.

Conclusions

This is the first evidence that Tan‐Ⅰ induced apoptosis and promoted autophagy via the inactivation of PI3K/AKT/mTOR pathway on ovarian cancer and further inhibited tumour growth, which might be considered as effective strategy.

Danshen: a phytochemical and pharmacological overview

Danshen, the dried root or rhizome of Salvia miltiorrhiza Bge., is a traditional and folk medicine in Asian countries, especially in China and Japan. In this review, we summarized the recent researches of Danshen in traditional uses and preparations, chemical constituents, pharmacological activities and side effects. A total of 201 compounds from Danshen have been reported, including lipophilic diterpenoids, water-soluble phenolic acids, and other constituents, which have showed various pharmacological activities, such as anti-inflammation, anti-oxidation, anti-tumor, anti-atherogenesis, and anti-diabetes. This article intends to provide novel insight information for further development of Danshen, which could be of great value to its improvement of utilization.

Tanshinone I inhibits the growth and metastasis of osteosarcoma via suppressing JAK/STAT3 signalling pathway

Tanshinone I (Tan I) is a widely used diterpene compound derived from the traditional Chinese herb Danshen. Increasing evidence suggests that it exhibits anti-cancer activity in various human cancers. However, the in vitro and in vivo effects of Tan I on osteosarcoma (OS) remain inadequately elucidated, especially those against tumour metastasis. Our results showed that Tan I significantly inhibited OS cancer cell proliferation, migration and invasion and induced cell apoptosis in vitro. Moreover, treatment with 10 and 20 mg/kg Tan I effectively suppressed tumour growth in subcutaneous xenografts and orthotopic xenograft mouse models. In addition, Tan I significantly inhibited tumour metastasis in intracardiac inoculation xenograft models. The results also showed that Tan I-induced increased expression of the proapoptotic gene Bax and decreased expression of the anti-apoptotic gene Bcl-2 is the possible mechanism of its anti-cancer effects. Tan I was also found to abolish the IL-6-mediated activation of the JAK/STAT3 signalling pathway. Conclusively, this study is the first to show that Tan I suppresses OS growth and metastasis in vitro and in vivo, suggesting it may be a potential novel and efficient drug candidate for the treatment of OS progression.

Potentiation of the anticancer effect of doxorubicinin drug-resistant gastric cancer cells by tanshinone IIA

BACKGROUND

Gastric cancer is the fifth commonest cancer and the third cause of cancer-related deaths all over the world. The effectiveness of chemotherapy is still limited by drug resistance in gastric cancer. Tanshinones, abietane diterpenes isolated from the traditional Chinese medicine Danshen (Salvia miltiorrhiza), have exhibited versatile anticancer activities in particular the ability to overcome drug resistance in different cancers.

PURPOSE

The current study aimed to explore the capacity of tanshinone IIA, the most abundant tanshinone found in the plant Danshen, to overcome drug resistance of gastric cancer cells to a commonly used anticancer drug doxorubicin.

STUDY DESIGN

Sensitivity of cell lines to doxorubicin was determined by MTT assay. Doxorubicin resistant gastric cancer cell lines was established by step selection with increasing concentrations of doxorubicin. Cell cycle arrest, apoptosis and doxorubicin efflux were analyzed by flow cytometry. The expression of MRP1 was determined by realtime PCR and western-blot.

RESULTS

Based on the IC₅₀ values of doxorubicin, we identified the doxorubicin-sensitive gastric cancer cell lines SNU-719 and SNU-610 as well as the cell lines relatively resistant to doxorubicin including SNU-638, SNU-668, SNU-216 and SNU-620. We also established two drug-resistant cell lines SNU-719R and SNU-610R. Despite the fact that tanshinone IIA alone showed no cytotoxicity on these gastric cells, we found the potentiation of the anticancer effect of doxorubicin in drug-resistant gastric cancer cells by tanshinone IIA. Furthermore, using doxorubicin-sensitive cell line SNU-719 and doxorubicin-resistant cell lines SNU-719R and SNU-620, we revealed the pivotal roles of MRP1. Its overexpression impaired cell cycle arrest and suppressed apoptosis in the development of both intrinsic and acquired drug resistance in gastric cancer cells to doxorubicin. Importantly, inhibition of MRP1 function enhanced cell cycle arrest, increased apoptosis and induced autophagic cell death which contributed to the capability of tanshinone IIA to potentiate the anticancer effect of doxorubicin in drug-resistant gastric cancer cells.

CONCLUSION

Tanshinone IIA is an interesting agent with potential to treat drug-resistant gastric cancer in combination therapy.

Tanshinone I attenuates proliferation and chemoresistance of cervical cancer in a KRAS-dependent manner

Chemoresistance is a common occurrence during advanced or recurrent cervical cancer therapy when treated by conventional treatment, platinum-based chemotherapy. This study aimed to investigate the effect and underlying mechanism of tanshinone I on attenuating proliferation and chemoresistance of cervical cancer cells. In cervical cancer cells, cell proliferation was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cell count, and soft-agar colony-formation assay. rVista analysis and luciferase reporter assay were used to explore the upstream regulator of KRAS, and the expression levels of key genes were also detected. Western blot analysis showed that tanshinone I significantly suppressed KRAS expression and inhibited AKT phosphorylation. rVista analysis and luciferase reporter assay demonstrated that ELK1 can binds directly to KRAS promoter and positively regulates KRAS expression. MTT assay showed that KRAS or ELK1 overexpression significantly attenuated the suppressive effects of tanshinone I on HeLa cells proliferation. In addition, tanshinone I recovered the cisplatin sensitivity of HeLa CR cells, whereas KRAS or ELK1 overexpression significantly inhibited this phenomenon. Our results suggested that tanshinone I had anticancer effects on cervical cancer cells via inhibiting ELK1 and downregulating KRAS-AKT axis, which subsequently suppressed the proliferation and cisplatin resistance of cervical cancer cells.

Discovery of cancer cell proliferation inhibitors from Salviae miltiorrhizae radix et rhizoma by a trace peak enrichment approach

Salviae miltiorrhizae radix et rhizoma is a traditional herbal medicine with anti-cancer activities. In this work, a trace peak enrichment approach combined with a cell proliferation assay was applied for screening cancer cell proliferation inhibitors from the extract of S. miltiorrhiza. A set of 123 peak fractions were prepared, and by comprehensive screening, 21 tanshinones were screened out as cancer cell proliferation inhibitors and their structures were tentatively identified by liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry analysis. The inhibitory activities of nine available screened tanshinones were validated, with their IC₅₀ values ranging from 0.63 to 28.40 μM, indicating their activities strongly inhibit the proliferation of cancer cells. This study presents tanshinones that are potential cancer cell proliferation inhibitors and may explain the anti-cancer activity of S. miltiorrhiza.

Effects of tanshinones mediated by forkhead box O3a transcription factor on the proliferation and apoptosis of lung cancer cells

According to global cancer statistics in 2012, lung cancer (LC) was the most frequently diagnosed cancer and the leading cause of cancer-associated mortality among males worldwide. Owing to the limited therapeutic approaches available, novel methods for treating LC are required. Tanshinones (Ts) have previously been proved to be effective in treating cardiovascular disease, inflammatory disease and cancer, and have been reported to regulate cell proliferation and apoptosis of LC. The underlying molecular mechanism of action of Ts remains unclear. Furthermore, forkhead box O3a (FoxO3a) has been reported to be a critical gene in cell apoptosis. Therefore, the A549 lung cancer cell line was transfected with FoxO3a small interfering RNA (siRNA) or scrambled siRNA, and the cells which exhibited the most successful transfection efficacy were selected for further investigation into the underlying molecular mechanism of the influence of Ts on FoxO3a in LC cells. Various concentrations of Ts were assigned to experimental groups I-IV (5, 10, 20 and 30 µmol/l Ts, respectively). An MTT assay revealed that Ts inhibited cell proliferation in a dose- and time-dependent manner compared with the control group (CON; without Ts administration) with a maximal dose of 20 µmol/l at 72 h treatment (P<0.05). Similarly, compared with CON, flow cytometry results revealed that Ts induce LC cell apoptosis in a dose-dependent manner (P<0.05). Consistently, the expression levels of FoxO3a mRNA and protein were restored following treatment with Ts in a dose-dependent manner, alongside caspase-3 activation. On the basis of these results, we hypothesize that Ts regulate LC cell proliferation and apoptosis by triggering an apoptotic cascade through the FoxO3a/caspase-3 signaling pathway.

Antioxidant property of Taraxacum formosanum Kitam and its antitumor activity in non-small-cell lung cancer cells

BACKGROUND

Non-small-cell lung cancer (NSCLC) is known to exhibit resistance to various therapeutic agents and become progressively incurable. Taraxacum formosanum is a medicinal Chinese herb that has been clinically used in Taiwan. However, the investigations of the effects of whole plant on lung cancer are limited.

PURPOSE

This study evaluated the in vitro antioxidant, antiproliferative, and antimigration effects of the ethanol extract of T. formosanum (ETF). The possible molecular mechanism underlying its antitumor effects on cultured human NSCLC cell lines was also elucidated.

METHODS

The antioxidant effects of the ETF were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Trolox equivalent antioxidant capacity (TEAC) assays, and its antiproliferative and antimigration effects were determined using trypan blue exclusion and wound healing assays, respectively. In addition, changes in the mitogen-activated protein kinase (MAPK) signaling pathway were investigated using Western blot analyses. Various inhibitors were used to determine the roles of the MAPK signaling pathway involved in the molecular mechanism of the ETF.

RESULTS

Our results showed that the ETF exhibited strong reducing power, a high Trolox equivalent antioxidant capacity (TEAC) value, and potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and Fe⁺²-chelating abilities. The ETF also exerted antiproliferative and antimigration effects on NSCLC cells in a dose-dependent manner. These effects may be mediated by the inhibitory effects of the ETF on the activation of extracellular signal-regulated kinase.

CONCLUSIONS

This study performed the first pharmacological exploration of T. formosanum. Our results demonstrated the antioxidant and antitumor effects of the ETF on NSCLC cell lines, indicating their potential preventive and therapeutic values for lung cancer.

Tanshinone IIA Sodium Sulfonate Attenuates LPS-Induced Intestinal Injury in Mice

Background

Tanshinone IIA sodium sulfonate (TSS) is known to possess anti-inflammatory effects and has exhibited protective effects in various inflammatory conditions; however, its role in lipopolysaccharide- (LPS-) induced intestinal injury is still unknown.

Objective

The present study is designed to explore the role and possible mechanism of TSS in LPS-induced intestinal injury.

Methods

Male C57BL/6J mice, challenged with intraperitoneal LPS injection, were treated with or without TSS 0.5 h prior to LPS exposure. At 1, 6, and 12 h after LPS injection, mice were sacrificed, and the small intestine was excised. The intestinal tissue injury was analyzed by HE staining. Inflammatory factors (TNF-α, IL-1β, and IL-6) in the intestinal tissue were examined by ELISA and RT-PCR. In addition, expressions of autophagy markers (microtubule-associated light chain 3 (LC3) and Beclin-1) were detected by western blot and RT-PCR. A number of autophagosomes were also observed under electron microscopy.

Results

TSS treatment significantly attenuated small intestinal epithelium injury induced by LPS. LPS-induced release of inflammatory mediators, including TNF-α, IL-1β, and IL-6, were markedly inhibited by TSS. Furthermore, TSS treatment could effectively upregulate LPS-induced decrease of autophagy levels, as evidenced by the increased expression of LC3 and Beclin-1, and more autophagosomes.

Conclusion

The protective effect of TSS on LPS-induced small intestinal injury may be attributed to the inhibition of inflammatory factors and promotion of autophagy levels. The present study may provide novel insight into the molecular mechanisms of TSS on the treatment of intestinal injury.

Activation of JNK and IRE1 is critically involved in tanshinone I-induced p62 dependent autophagy in malignant pleural mesothelioma cells: implication of p62 UBA domain

The aim of present study is to elucidate autophagic mechanism of tanshinone I (Tan I) in H28 and H2452 mesothelioma cells. Herein, Tan I exerted cytotoxicity with autophagic features of autophagy protein 5 (ATG5)/ microtubule-associated protein 1A/1B-light chain 3II (LC3 II) activation, p62/sequestosome 1 (SQSTM1) accumulation and increased number of LC3II punctae, acridine orange-stained cells and autophagic vacuoles. However, 3-methyladenine (3MA) and NH4Cl increased cytotoxicity in Tan I treated H28 cells. Furthermore, autophagy flux was enhanced in Tan I-treated H28 cells transfected by RFP-GFP-LC3 constructs, with colocalization of GFP-LC3 punctae with LAMP1 or Lysotracker. Interestingly, C-terminal UBA domain is required for Tan 1 induced aggregation of p62 in H28 cells. Notably, Tan I upregulated CCAAT-enhancer-binding protein homologous protein (CHOP), inositol-requiring protein-1 (IRE1) and p-c-Jun N-terminal kinase (p-JNK), but silencing of IRE1 or p62 and JNK inhibitor SP600125 blocked the LC3II accumulation in Tan I-treated H28 cells. Overall, these findings demonstrate that Tan I exerts antitumor activity through a compromise between apoptosis and p62/SQSTM1-dependent autophagy via activation of JNK and IRE 1 in malignant mesothelioma cells.

Dihydroisotanshinone I combined with radiation inhibits the migration ability of prostate cancer cells through DNA damage and CCL2 pathway

BACKGROUND

Radiotherapy plays an important role in the treatment of prostate cancer. Despite that sophisticated techniques of radiotherapy and radiation combined with chemotherapy were applied to the patients, some tumors may recur. Therefore, the study investigated the effect of dihydroisotanshinone I (DT) and the combination treatment of 5 μM DT and 5Gy irradiation (IR) against the migration ability of prostate cancer cells.

METHODS

DT and the combination treatment were studied for its biological activity against migration ability of prostate cancer cells with transwell migration assay. Subsequently, we tried to explore the underlying mechanism with ELISA, flow cytometry and Western's blotting assay.

RESULTS

The results showed that DT and the combination treatment substantially inhibited the migration ability of prostate cancer cells. DT and the combined treatment can decrease the ability of macrophages to recruit prostate cancer cells. Mechanistically, DT and the combination treatment reduced the secretion of chemokine (C-C Motif) Ligand 2 (CCL2) from prostate cancer cells. We also found that DT treatment induced the cell cycle of prostate cancer cells entering S phase and increased the protein expression of DNA damage response proteins (rH2AX and phosphorylated ataxia telangiectasia-mutated [ATM]) in DU145 cells and PC-3 cells.

CONCLUSIONS

DT displays radiosensitization and antimigration effects in prostate cancer cells by inducing DNA damage and inhibiting CCL2 secretion. We suggest that DT can be used as a novel antimetastatic cancer drug or radiosensitizer in the armamentarium of prostate cancer management.

Effect of early use of Chinese herbal products on mortality rate in patients with lung cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Patients with lung cancer are frequently treated with Western medical treatments. Recently, patients have begun to use Chinese medicine to strengthen the immune system and alleviate side effects.

AIM OF THE STUDY

We aimed to evaluate the association between mortality rate and early use of Chinese herbal products (CHPs) among patients with lung cancer.

MATERIALS AND METHODS

We conducted a retrospective cohort study based on the National Health Insurance Research Database, Taiwan Cancer Registry, and Cause of Death Data. Patients with newly diagnosed lung cancer between 2002 and 2010 were classified as either the CHP (n = 422) or the non-CHP group (n = 2828) based on whether they used CHP within 3 months after first diagnosis of lung cancer. A robust Cox regression model was used to examine the hazard ratio (HR) of death for propensity score (PS) matching samples.

RESULTS

After PS matching, average survival time of the CHP group was significantly longer than that of the non-CHP group. The adjusted HR (0.82; 95% CI: 0.73-0.92) in the CHP group was lower than the non-CHP group. Stratified by clinical cancer stages, CHP group had longer survival time in stage 3 subgroup. When the exposure period of CHP use was changed from 3 to 6 months, results remained similar (HR = 0.85; 95% CI: 0.76-0.95).

CONCLUSION

Results indicated that patients with lung cancer who used CHP within 3 months after first diagnosis had a lower hazard of death than non-CHP users, especially for stage 3 lung cancer. Further experimental studies are needed to examine the causal relationship.

15, 16-Dihydrotanshinone I Inhibits Hemangiomas through Inducing Pro-apoptotic and Anti-angiogenic Mechanisms in Vitro and in Vivo

Infantile hemangioma (IH) is a common and benign vascular neoplasms, which has a high incidence in children. Although IH is benign, some patients experience complications such as pain, functional impairment, and permanent disfigurement. Treatment options for IH include corticosteroids, surgery, vincristine, interferon or cyclophosphamide. However, none of these modalities are ideal due to restrictions or potential serious side effects. There is thus a great need to explore novel treatments for IH with less side effects. Angiogenesis, vasculogenesis and tumorigenesis are the main features of IH. Tanshen is mostly used in Chinese traditional medicine to treat hematological abnormalities. Therefore, the aim of our study was to evaluate anti-proliferation and anti-angiogenesis effects on hemangiomas cells by extracted Tanshen compounds compared with propranolol, the first-line treatment for IH currently, both in vitro and in vivo. Cell viability, apoptosis, protein expression and anti-angiogenesis were analyzed by CCK8, Annexin V staining, Western blot and tube formation, respectively. The anti-tumor activity in vivo was evaluated using a mouse xenograft model. Fourteen major compounds extracting from Tanshen were screened for their ability to inhibit hemangiomas cells. Of the 14 compounds investigated, 15,16-Dihydrotanshinone I (DHTS) was the most potent modulator of EOMA cell biology. DHTS could significantly decrease EOMA cells proliferation by inducing cell apoptosis, which is much more efficient than propranolol in vitro. DHTS increased the expression of several apoptosis-related proteins, including caspase9, caspase3, PARP, AIF, BAX, cytochrome c, caspase8 and FADD and significantly inhibited angiogenesis, as indicated by reduced tube formation and diminished expression of vascular endothelial cell growth factor receptor 2 and matrix metalloproteinase 9. In nude mice xenograft experiment, DHTS (10 mg/kg) could significantly inhibit the tumor growth of EOMA cells as well as propranolol (40 mg/kg). Our study showed that DHTS was much more effective than propranolol in inhibiting hemangiomas proliferation and angiogenesis in vitro and in vivo, which could have potential therapeutic applications for treatment of IH.

Tanshinones inhibit hIAPP aggregation, disaggregate preformed hIAPP fibrils, and protect cultured cells

Tanshinones act as common inhibitors to inhibit the aggregation of both hIAPP and Aβ, disaggregate preformed hIAPP and Aβ amyloid fibrils, and protect cells from hIAPP- and Aβ-induced toxicity.

Salvianolic acid A, a novel PI3K/Akt inhibitor, induces cell apoptosis and suppresses tumor growth in acute myeloid leukemia

Salvianolic acid A (SAA), one of the main derivatives of Salvia miltiorrhiza, has been shown to possess anti-inflammatory and anti-thrombotic activities. Its role in inhibiting tumor growth, however, remains elusive. The aim of this study was to investigate the effect of SAA on acute myeloid leukemia (AML). Here, SAA showed a dose-dependent cell viability inhibition and apoptosis induction in AML cells. At the molecular level, SAA increased the expression of Bak and decreased the expression of Bcl-xL, following by PARP cleavage and caspase-3 activation. SAA also markedly attenuated Akt phosphorylation in AML cells. In a xenograft mouse model, SAA significantly suppressed the growth of AML tumors in vivo. Furthermore, SAA exhibited a more profound pro-apoptotic effect on primary AML cells than on bone marrow mononuclear cells from patients with benign diseases. Therefore, the pro-apoptotic and anti-tumor properties of SAA suggested its promising therapeutic value for AML.

Experimental and Theoretical Studies on Iron-Promoted Oxidative Annulation of Arylglyoxal with Alkyne: Unusual Addition and Migration on the Aryl Ring

An Fe(III)-promoted oxidative annulation reaction was developed for the synthesis of 1,2-naphthoquinones. A variety of substituted arylglyoxals and internal alkynes undergo the transformation in the presence of FeCl₃ at room temperature to afford the 1,2-naphthoquinone products in good yields in a short reaction time. Interestingly, the products show unusual pseudomigration of the substituent on the arene ring of arylglyoxals. A possible mechanism involving Fe(III)-promoted formation of a vinyl cation from arylglyoxal and alkyne, electrophilic addition of the vinyl cation to the ipso carbon of the aryl group to give a spiral intermediate, and then migration of the keto carbon to the ortho carbon was proposed as key steps and verified using quantum mechanics.

Bioavailability and pharmacokinetic comparison of tanshinones between two formulations of Salvia miltiorrhiza in healthy volunteers

Salvia miltiorrhiza (SM) is widely used to treat microcirculatory disturbance-related diseases; its lipophilic components play important roles in this application. Cryptotanshinone (CTS), tanshinone I (TSI) and tanshinone IIA (TSA) are the most widely-studied lipophilic ingredients, but low oral bioavailability limits their clinical application. It has been proven that micronization could improve the bioavailability of some drugs, so we’ve conducted this randomized study to investigate whether micronized granular powder (GP) of SM could improve the bioavailability of tanshinones compared with traditional decoction (TD). An oral dose of TD or GP of SM was administrated to subjects and blood samples were collected at predetermined time points. The plasma concentrations of tanshinones were detected by a validated method and pharmacokinetic parameters were calculated using a non-compartmental model. GP of SM resulted in a significant increase in mean maximum plasma concentration (C_max), elimination half-life and area under concentration-time curve (AUC) of tanshinones, with the plasma AUC of CTS, TSI and TSA in GP 5–184, 4–619 and 5–130 times higher than TD. In addition, the individual variances of C_max and AUC were much lower after GP administration. Summarily, tanshinones in micronized GP of SM had higher oral bioavailability and lower individual variances, thus we speculate that it may indicate a better clinical efficacy and be a better choice than current treatments.

Breast cancer metastasis: Putative therapeutic role of vascular cell adhesion molecule-1

BACKGROUND

Breast cancer is a notable cause of cancer-related death in women worldwide. Metastasis to distant organs is responsible for ~90% of this death. Breast cells convert to malignant cancer cells after acquiring the capacity of invasion/intravasation into surrounding tissues and, finally, extravasation/metastasis to distant organs (i.e., lymph nodes, lungs, bone, brain). Metastasis to distant organs depends on interactions between disseminated tumor cells (DTCs) and the endothelium of blood vessels present in the tumor microenvironment. Among several known endothelial adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) has been found to be involved in this process. It has been shown that VCAM-1 is aberrantly expressed in breast cancer cells and that it can bind to its natural ligand α4β1integrin, also denoted as very late antigen 4 (VLA-4). This binding appears to be responsible for the metastasis of breast cancer cells to lung, bone and brain. The α4β1 integrin - VCAM-1 interaction thus represents a potential therapeutic target for metastatic breast cancer cells. The development of inhibitors of this interaction may be instrumental for the clinical management of breast cancer patients.

CONCLUSIONS

This study focuses on recent progress on the role of VCAM-1, an important glycoprotein belonging to the immunoglobulin (Ig) superfamily of cell surface adhesion molecules in breast cancer angiogenesis, survival and metastasis. Targeting VCAM-1, expressed on the surface of breast cancer cells, and/or its specific ligand VLA-4/α4β1 integrin, expressed on cells at the site of metastasis, may be a useful strategy to reduce breast cancer cell invasion and metastasis. Various approaches to therapeutically target VCAM-1 and VLA-4 are also discussed.

Inhibition of Proliferation of Prostate Cancer Cell Line DU-145 in vitro and in vivo Using Salvia miltiorrhiza Bunge

OBJECTIVE

To investigate the antiproliferative activity of Salvia miltiorrhiza Bunge. (SM) on the castration-resistant prostate cancer (CRPC) cell line DU-145, in vitro and in vivo.

METHODS

Prostate cancer cell line (DU-145) and normal prostate cell line (RWPE-1) were treated with SM at different concentrations (3.125, 12.5, 25 and 50 μg/mL) to investigate the antiproliferative effects. DNA laddering analysis was performed to investigate the apoptosis of DU-145 cells. Molecular mechanism was investigated by Western blot analysis of p53, Bcl-2, prostate specific antigen (PSA), and androgen receptor (AR). Six-week-old male BALB/c nude mice were randomly divided into normal control group (n=101) and treated group (n=101) which administered 500 mg/kg SM for 2 weeks. Tumor volumes were measured.

RESULTS

Treatment with SM resulted in a dose-dependent decrease in cell number of DU-145 cells in comparison with RWPE-1. DNA laddering analysis indicated the apoptosis of DU-145 cells. Treatment with SM increased the expression of p53 and reduced the expression of Bcl-2 proteins. The levels of PSA were considerably reduced in SM-treated group compared to the controls, and a decrease in AR expression was observed when cells were treated with SM in the same pattern as a reduction in PSA. In the tumour xenograft study, SM given once a day for 2 weeks significantly inhibited tumour growth.

CONCLUSION

SM might contribute to the anticancer actions such as induction of apoptosis and inhibition of proliferation of prostate cancer cells.

Tanshinone IIA Inhibits β-Catenin Nuclear Translocation and IGF-2R Activation via Estrogen Receptors to Suppress Angiotensin II-Induced H9c2 Cardiomyoblast Cell Apoptosis

Cardiomyopathy involves changes in the myocardial ultra-structure, hypertrophy, apoptosis, fibrosis and inflammation. Angiotensin II (AngII) stimulates the expression of insulin like-growth factors (IGF-2) and IGF-2 receptor (IGF-2R) in H9c2 cardiomyoblasts and subsequently leads to apoptosis. Estrogen receptors protect cardiomyocytes from apoptosis and fibrosis. Tanshinone IIA (TSN), a main active ingredient from Danshen, has been shown to protect cardiomyocytes from death caused by different stress signals. Estrogen receptor α (ER) is required for the rapid activation of the IGF-1R signaling cascade. This study aimed to investigate whether TSN protected H9c2 cardiomyocytes from AngII-induced activation of IGF-2R pathway and hypertrophy via ERs. We found that AngII caused the reduction in IGF-1R phosphorylation and the elevation of β-catenin and IGF-2R levels. This was reversed by increasing doses of TSN and of caspase-3 and ERK1/2 phosphorylation mediated by ERs. The phytoestrogen significantly attenuated AngII-induced apoptosis and suppressed the subsequent cardiac remodeling effect. Therefore, TSN reduced the AngII-induced activation of β-catenin and IGF-2R pathways, apoptosis and cardiac remodeling via ERs in H9c2 cardiomyoblasts.

Tanshinones suppress AURKA through up-regulation of miR-32 expression in non-small cell lung cancer

Tanshinone is the liposoluble constituent of Salia miltiorrhiza, a root used in traditional herbal medicine which is known to possess certain health benefits. Although it is known that tanshinones, including tanshinone I (T1), tanshinone IIA (T2A), and cryptotanshinone (CT), can inhibit the growth of lung cancer cells in vitro, the mechanism under which they act is still unclear. AURKA, an oncogene, encodes a serine-threonine kinase which regulates mitotic processes in mammalian cells. Here, we reported that tanshinones mediate AURKA suppression partly through up-regulating the expression of miR-32. We found that tanshinones could inhibit cell proliferation, promote apoptosis, and impede cell-cycle progression, thus performing an antineoplastic function in non-small cell lung cancer (NSCLC). Additionally, we demonstrated that tanshinones attained these effects in part by down-regulating AURKA, corroborating previous reports. Our results showed that in NSCLC, similar effects were obtained with knock-down of the AURKA gene by siRNA. We also verified that AURKA was the direct target of miR-32. Collectively, our results demonstrated that tanshinones could inhibit NSCLC by suppressing AURKA via up-regulating the expressions of miR-32 and other related miRNAs.

A facile three-step total synthesis of tanshinone I

A facile synthetic approach for total synthesis of tanshinone I has been accomplished. The key precursor is a novel compound, epoxy phenanthraquinone. And this synthesis of tanshinone I is achieved in only three simple stages, which include Diels-Alder reaction, Δ(2)-Weitz-Scheffer-type epoxidation, and Feist-Bénary reaction from commercially available styrene.

A promising "TRAIL" of tanshinones for cancer therapy

An ideal cancer therapy specifically targets cancer cells while sparing normal tissues. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) elicits apoptosis by engaging its cognate death receptors (DRs—namely, DR4 and DR5. The cancer cell-selective proapoptotic action of TRAIL is highly attractive for cancer therapy, but clinical application of TRAIL is rather limited due to tumors’ inherent or acquired TRAIL resistance. Combining TRAIL with agents that reverse resistance to it has proved promising in the sensitization of TRAIL-induced apoptosis. Noteworthy, natural compounds have already been validated as potential resources for TRAIL sensitizers. In this review, we focus on the recently identified TRAILsensitizing effect of tanshinones, the anticancer ingredients of the medicinal plant Salvia miltiorrhiza (Danshen in Chinese). Research from our laboratories and others have revealed the synergy of a tanshinones-TRAIL combination in diverse types of cancer cells through up-regulation of DR5 and/or down-regulation of antiapoptotic proteins such as survivin. Thus, in addition to their anticancer mechanisms, tanshinones as TRAIL sensitizers hold great potential to be translated to TRAIL-based therapeutic modalities for combatting cancer.

Dihydrotanshinone-I interferes with the RNA-binding activity of HuR affecting its post-transcriptional function

Post-transcriptional regulation is an essential determinant of gene expression programs in physiological and pathological conditions. HuR is a RNA-binding protein that orchestrates the stabilization and translation of mRNAs, critical in inflammation and tumor progression, including tumor necrosis factor-alpha (TNF). We identified the low molecular weight compound 15,16-dihydrotanshinone-I (DHTS), well known in traditional Chinese medicine practice, through a validated high throughput screening on a set of anti-inflammatory agents for its ability to prevent HuR:RNA complex formation. We found that DHTS interferes with the association step between HuR and the RNA with an equilibrium dissociation constant in the nanomolar range in vitro (Ki = 3.74 ± 1.63 nM). In breast cancer cell lines, short term exposure to DHTS influences mRNA stability and translational efficiency of TNF in a HuR-dependent manner and also other functional readouts of its post-transcriptional control, such as the stability of selected pre-mRNAs. Importantly, we show that migration and sensitivity of breast cancer cells to DHTS are modulated by HuR expression, indicating that HuR is among the preferential intracellular targets of DHTS. Here, we disclose a previously unrecognized molecular mechanism exerted by DHTS, opening new perspectives to therapeutically target the HuR mediated, post-transcriptional control in inflammation and cancer cells.

15,16-Dihydrotanshinone I from the Functional Food Salvia miltiorrhiza Exhibits Anticancer Activity in Human HL-60 Leukemia Cells: in Vitro and in Vivo Studies

15,16-Dihydrotanshinone I (DHTS) is extracted from Salvia miltiorrhiza Bunge which is a functional food in Asia. In this study, we investigated the apoptotic effect of DHTS on the human acute myeloid leukemia (AML) type III HL-60 cell line. We found that treatment with 1.5 μg/mL DHTS increased proapoptotic Bax and Bad protein expressions and activated caspases-3, -8, and -9, thus leading to poly ADP ribose polymerase (PARP) cleavage and resulting in cell apoptosis. DHTS induced sustained c-Jun N-terminal kinase (JNK) phosphorylation and Fas ligand (FasL) expression. The anti-Fas blocking antibody reversed the DHTS-induced cell death, and the JNK-specific inhibitor, SP600125, inhibited DHTS-induced caspase-3, -8, -9, and PARP cleavage. In a xenograft nude mice model, 25 mg/kg DHTS showed a great effect in attenuating HL-60 tumor growth. Taken together, these results suggest that DHTS can induce HL-60 cell apoptosis in vitro and inhibit HL-60 cell growth in vivo; the underlying mechanisms might be mediated through activation of the JNK and FasL signal pathways.