Tanshinone IIA induces intrinsic apoptosis in osteosarcoma cells both in vivo and in vitro associated with mitochondrial dysfunction

Phytochemicals Showing Antiangiogenic Effect in Pre-clinical Models and their Potential as an Alternative to Existing Therapeutics

Angiogenesis, the formation of new blood vessels from a pre-existing vascular network, is an important hallmark of several pathological conditions, such as tumor growth and metastasis, proliferative retinopathies, including proliferative diabetic retinopathy and retinopathy of prematurity, age-related macular degeneration, rheumatoid arthritis, psoriasis, and endometriosis. Putting a halt to pathology-driven angiogenesis is considered an important therapeutic strategy to slow down or reduce the severity of pathological disorders. Considering the attrition rate of synthetic antiangiogenic compounds from the lab to reaching the market due to severe side effects, several compounds of natural origin are being explored for their antiangiogenic properties. Employing pre-clinical models for the evaluation of novel antiangiogenic compounds is a promising strategy for rapid screening of antiangiogenic compounds. These studies use a spectrum of angiogenic model systems that include HUVEC two-dimensional culture, nude mice, chick chorioallantoic membrane, transgenic zebrafish, and dorsal aorta from rats and chicks, depending upon available resources. The present article emphasizes the antiangiogenic activity of the phytochemicals shown to exhibit antiangiogenic behavior in these well-defined existing angiogenic models and highlights key molecular targets. Different models help to get a quick understanding of the efficacy and therapeutics mechanism of emerging lead molecules. The inherent variability in assays and corresponding different phytochemicals tested in each study prevent their immediate utilization in clinical studies. This review will discuss phytochemicals discovered using suitable preclinical antiangiogenic models, along with a special mention of leads that have entered clinical evaluation.

Tanshinone IIA targeting cell signaling pathways: a plausible paradigm for cancer therapy

Natural compounds originating from plants offer a wide range of pharmacological potential and have traditionally been used to treat a wide range of diseases including cancer. Tanshinone IIA (Tan IIA), a bioactive molecule found in the roots of the Traditional Chinese Medicine (TCM) herb Salvia miltiorrhiza, has been shown to have remarkable anticancer properties through several mechanisms, such as inhibition of tumor cell growth and proliferation, metastasis, invasion, and angiogenesis, as well as induction of apoptosis and autophagy. It has demonstrated excellent anticancer efficacy against cell lines from breast, cervical, colorectal, gastric, lung, and prostate cancer by modulating multiple signaling pathways including PI3K/Akt, JAK/STAT, IGF-1R, and Bcl-2-Caspase pathways. This review focuses on the role of Tan IIA in the treatment of various cancers, as well as the underlying molecular mechanisms.

Advances on Natural Abietane, Labdane and Clerodane Diterpenes as Anti-Cancer Agents: Sources and Mechanisms of Action

Extensive research over the past decades has identified numerous phytochemicals that could represent an important source of anti-cancer compounds. There is an immediate need for less toxic and more effective preventive and therapeutic strategies for the treatment of cancer. Natural compounds are considered suitable candidates for the development of new anti-cancer drugs due to their pleiotropic actions on target events with multiple manners. This comprehensive review highlighted the most relevant findings achieved in the screening of phytochemicals for anticancer drug development, particularly focused on a promising class of phytochemicals such as diterpenes with abietane, clerodane, and labdane skeleton. The chemical structure of these compounds, their main natural sources, and mechanisms of action were critically discussed.

Tanshinol suppresses osteosarcoma by specifically inducing apoptosis of U2-OS cells through p53-mediated mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Salviae miltiorrhizae (also called Danshen in traditional Chinese medicine) is a famous herbal medicine, which has been frequently used to treat blood stasis syndrome including osteosarcoma (OS) in traditional Chinese medicine. Main components of Danshen have been assumed to exhibit anti-OS capacity. Nevertheless, tanshinol (TS, main component of Danshen)'s efficacy and mechanism in OS hasn't been clearly described ever since. This drew our attention, since OS is the most frequent primary bone carcinomas in children and adolescents, with a high incidence and fatality rate. Unfortunately, chemotherapy for OS has faced many clinical challenges due to the increasing chemoresistance and recurrence. This study was then designed to deeply explore TS's role in OS therapy.

AIM OF THE STUDY

To explore the anti-OS efficacy and mechanism of TS, we conducted in vivo and in vitro experiments by using a zebrafish xenograft model and U2-OS cells.

MATERIALS AND METHODS

CCK-8 assay, DAPI and γ-H2A.X immunofluorescence staining, and flow cytometry (apoptosis verification) were employed to determine the anti-proliferative and pro-apoptotic effects of TS. qPCR and Western blot were used to examine TS's molecular actions and mechanism on apoptosis of U2-OS cells.

RESULTS

The in vivo data showed that TS significantly inhibited U2-OS tumor growth in larval zebrafish from 2 to 20 ng/mL. In vitro data indicated that TS exerted significant anti-proliferative and pro-apoptotic effects on U2-OS cells in a dose-dependent manner. Moreover, TS has no inhibitory effect on bMSCs, suggesting its safety on normal bone-forming cells. Molecular data illustrated that TS obviously activated the p53 signaling-related proteins (p-p53, Bax, CASP3, CASP9) and its upstream JNK (p-JNK, p-c-JUN) and ATM (p-ATM) signaling molecules through phosphorylation and cleavage, followed by up-regulation of the pro-apoptotic genes, NOXA, PUMA, TP53, BAX, and BIM, and down-regulation of Bcl-2 protein.

CONCLUSION

In sum, TS specifically induced apoptosis of U2-OS cells by activating p53 signaling pathways, indicating TS as a promising candidate for OS treatment.

Salvia miltiorrhiza Protects Endothelial Dysfunction against Mitochondrial Oxidative Stress

Salvia miltiorrhiza (SM) is a common traditional Chinese medicine used in the treatment of cardiovascular and cerebrovascular diseases. Endothelial dysfunction plays an important role in the pathology of cardiovascular diseases. Endothelial dysfunction may induce inflammation and change vascular tone and permeability. The main pathological mechanism of endothelial dysfunction is the formation of reactive oxygen species (ROS). Mitochondria are the main source of energy and can also produce large amounts of ROS. Recent studies have shown that extracts of SM have antioxidative, anti-inflammatory, and antithrombus properties. In this review, we discuss the mechanism of oxidative stress in the mitochondria, endothelial dysfunction, and the role of SM in these oxidative events.

Recent Research Progress (2015-2021) and Perspectives on the Pharmacological Effects and Mechanisms of Tanshinone IIA

Tanshinone IIA (Tan IIA) is an important characteristic component and active ingredient in Salvia miltiorrhiza, and its various aspects of research are constantly being updated to explore its potential application. In this paper, we review the recent progress on pharmacological activities and the therapeutic mechanisms of Tan IIA according to literature during the years 2015-2021. Tan IIA shows multiple pharmacological effects, including anticarcinogenic, cardiovascular, nervous, respiratory, urinary, digestive, and motor systems activities. Tan IIA modulates multi-targets referring to Nrf2, AMPK, GSK-3β, EGFR, CD36, HO-1, NOX4, Beclin-1, TLR4, TNF-α, STAT3, Caspase-3, and bcl-2 proteins and multi-pathways including NF-κB, SIRT1/PGC1α, MAPK, SREBP-2/Pcsk9, Wnt, PI3K/Akt/mTOR pathways, TGF-β/Smad and Hippo/YAP pathways, etc., which directly or indirectly influence disease course. Further, with the reported targets, the potential effects and possible mechanisms of Tan IIA against diseases were predicted by bioinformatic analysis. This paper provides new insights into the therapeutic effects and mechanisms of Tan IIA against diseases.

Potential of natural products in osteosarcoma treatment: Focus on molecular mechanisms

Osteosarcoma is the most frequent type of bone cancer found in children and adolescents, and commonly arises in the metaphyseal region of tubular long bones. Standard therapeutic approaches, such as surgery, chemotherapy, and radiation therapy, are used in the management of osteosarcoma. In recent years, the mortality rate of osteosarcoma has decreased due to advances in treatment methods. Today, the scientific community is investigating the use of different naturally derived active principles against various types of cancer. Natural bioactive compounds can function against cancer cells in two ways. Firstly they can act as classical cytotoxic compounds by non-specifically affecting macromolecules, such as DNA, enzymes, and microtubules, which are also expressed in normal proliferating cells, but to a greater extent by cancer cells. Secondly, they can act against oncogenic signal transduction pathways, many of which are activated in cancer cells. Some bioactive plant-derived agents are gaining increasing attention because of their anti-cancer properties. Moreover, some naturally-derived compounds can significantly promote the effectiveness of standard chemotherapy drugs, and in certain cases are able to ameliorate drug-induced adverse effects caused by chemotherapy. In the present review we summarize the effects of various naturally-occurring bioactive compounds against osteosarcoma.

Tanshinone I restrains osteosarcoma progression by regulating circ_0000376/miR-432-5p/BCL2 axis

Circular RNAs (circRNAs) have been identified as important regulators in cancer progression. Nevertheless, little is known about the biological function of circ_0000376 in the progression of osteosarcoma (OS). Cell viability, colony formation ability, apoptosis, and motility were analyzed by Cell Counting Kit-8 assay, colony formation assay, flow cytometry, and transwell assays. Cellular glycolytic metabolism was analyzed using commercial kits. RT-qPCR and Western blot assay were performed to analyze RNA and protein expression in OS tissues and cells. Starbase software was used to establish circRNA-microRNA (miRNA)-messenger RNA linkage, and intermolecular interaction was verified by dual-luciferase reporter assay. Xenograft tumor assay was conducted to analyze the effects of Tanshinone I (Tan I) and circ_0000376 on xenograft tumor growth in vivo. Tan I treatment suppressed the viability, migration, invasion, and glycolysis and triggered the apoptosis of OS cells. Tan I treatment markedly down-regulated circ_0000376 expression in OS cells. The addition of circ_0000376 plasmid largely rescued the malignant behaviors of OS cells upon Tan I exposure. Circ_0000376 interacted with miR-432-5p in OS cells. Circ_0000376 overexpression-mediated protective effects in Tan I-induced OS cells were partly attenuated by the accumulation of miR-432-5p. miR-432-5p bound to the 3' untranslated region (3'UTR) of B-cell leukemia/lymphoma 2 (BCL2) in OS cells. miR-432-5p interference-induced effects in Tan I-treated OS cells were partly overturned by the silence of BCL2. Circ_0000376 can act as miR-432-5p sponge to up-regulate BCL2 expression in OS cells. Circ_0000376 silencing contributed to the anti-tumor effect of Tan I on the growth of xenograft tumors in vivo. Tan I exerted an anti-tumor role in OS progression by targeting circ_0000376/miR-432-5p/BCL2 axis.

Dihydroisotanshinone I as a Treatment Option for Head and Neck Squamous Cell Carcinomas

Head and neck squamous cell carcinomas (HNSCCs) are the most common cancers of the head and neck, and their prevalence is rapidly increasing. HNSCCs present a clinical challenge because of their high recurrence rate, therapeutic resistance to radiation and chemotherapy drugs, and adverse effects. Hence, traditional Chinese herbal treatment may be advantageous to therapeutic strategies for HNSCCs. Danshen (Salvia miltiorrhiza), a well-known Chinese herb, has been extensively applied in treatments for various diseases, including cancer, because of its high degree of safety and low rate of adverse effects despite its unclear mechanism. Thus, we aimed to explore the possible anticancer effects and mechanisms of dihydroisotanshinone I (DT), a compound in danshen (extract from danshen), on HNSCCs. Three HNSCCs cell lines were used for in vitro studies, and a Detroit 562 xenograft mouse model was chosen for in vivo studies. Our in vitro results showed that DT could initiate apoptosis, resulting in cell death, and the p38 signaling partially regulated DT-initiated cell apoptosis in the Detroit 562 model. In the xenograft mouse model, DT reduced tumor size with no obvious adverse effect of hepatotoxicity. The present study suggests that DT is a promising novel candidate for anti-HNSCCs therapy.

Tanshinones induce tumor cell apoptosis via directly targeting FHIT

The liposoluble tanshinones are bioactive components in Salvia miltiorrhiza and are widely investigated as anti-cancer agents, while the molecular mechanism is to be clarified. In the present study, we identified that the human fragile histidine triad (FHIT) protein is a direct binding protein of sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of Tanshinone IIA (TSA), with a Kd value of 268.4 ± 42.59 nM. We also found that STS inhibited the diadenosine triphosphate (Ap3A) hydrolase activity of FHIT through competing for the substrate-binding site with an IC₅₀ value of 2.2 ± 0.05 µM. Notably, near 100 times lower binding affinities were determined between STS and other HIT proteins, including GALT, DCPS, and phosphodiesterase ENPP1, while no direct binding was detected with HINT1. Moreover, TSA, Tanshinone I (TanI), and Cryptotanshinone (CST) exhibited similar inhibitory activity as STS. Finally, we demonstrated that depletion of FHIT significantly blocked TSA's pro-apoptotic function in colorectal cancer HCT116 cells. Taken together, our study sheds new light on the molecular basis of the anti-cancer effects of the tanshinone compounds.

Tanshinone IIA enhances susceptibility of non-small cell lung cancer cells to NK cell-mediated lysis by up-regulating ULBP1 and DR5

Natural killer (NK) cells have a great potential in cancer immunotherapy. However, their therapeutic efficacy is clinically limited owing to cancer cell immune escape. Therefore, it is urgently necessary to develop novel method to improve the antitumor immunity of NK cells. In the present study, it was found that the natural product tanshinone IIA (TIIA) enhanced NK cell-mediated killing of non-small cell lung cancer (NSCLC) cells. TIIA in combination with adoptive transfer of NK cells synergistically suppressed the tumor growth of NSCLC cells in an immune-incompetent mouse model. Furthermore, TIIA significantly inhibited the tumor growth of Lewis lung cancer (LLC) in an immune-competent syngeneic mouse model, and such inhibitory effect was reversed by the depletion of NK cells. Moreover, TIIA increased expressions of ULBP1 and DR5 in NSCLC cells, and inhibition of DR5 and ULBP1 reduced the enhancement of NK cell-mediated lysis by TIIA. Besides, TIIA increased the levels of p-PERK, ATF4 and CHOP. Knockdown of ATF4 completely reversed the up-regulation of ULBP1 and DR5 by TIIA in all detected NSCLC cells, while knockdown of CHOP only partly reduced these enhanced expressions in small parts of NSCLC cells. These results demonstrated that TIIA could increase the susceptibility of NSCLC cells to NK cell-mediated lysis by up-regulating ULBP1 and DR5, suggesting that TIIA had a promising potential in cancer immunotherapy, especially in NK cell-based cancer immunotherapy.

Salvianolic acid A inhibits the growth of diffuse large B-cell lymphoma through MAPK pathways

Treatment options are limited in patients with diffuse large B-cell lymphoma (DLBCL). Salvianolic acid A (SAA) is a water-soluble phenolic acid extracted from Salvia miltiorrhiza (Danshen) with anti-tumor properties. The anti-leukemic activity of SAA found in our recent research prompted us to investigate the therapeutic effect and mechanism of action of SAA in DLBCL. In the work described here, we found that SAA inhibited the viability of DLBCL cells by inducing cellular apoptosis, which was accompanied by upregulation of Bax and cleavage of PARP. Pre-incubation of SAA increased the phosphorylation of JNK, while it decreased the phosphorylation of p38 and ERK in DLBCL cells. Importantly, pharmacologic JNK inhibition partially mitigated the anti-survival effect of SAA, and inhibition of p38 and ERK synergized with SAA. Furthermore, SAA suppressed DLBCL tumor growth in a xenograft mouse model in vivo. Therefore, our data suggest the therapeutic utility of SAA in the management of DLBCL.

Tanshinone IIA: A Review of its Anticancer Effects

Tanshinone IIA (Tan IIA) is a pharmacologically lipophilic active constituent isolated from the roots and rhizomes of the Chinese medicinal herb Salvia miltiorrhiza Bunge (Danshen). Tan IIA is currently used in China and other neighboring countries to treat patients with cardiovascular system, diabetes, apoplexy, arthritis, sepsis, and other diseases. Recently, it was reported that tan IIA could have a wide range of antitumor effects on several human tumor cell lines, but the research of the mechanism of tan IIA is relatively scattered in cancer. This review aimed to summarize the recent advances in the anticancer effects of tan IIA and to provide a novel perspective on clinical use of tan IIA.

An overview of the anti-cancer actions of Tanshinones, derived from Salvia miltiorrhiza (Danshen)

Tanshinone is a herbal medicinal compound described in Chinese medicine, extracted from the roots of Salvia miltiorrhiza (Danshen). This family of compounds, including Tanshinone IIA and Tanshinone I, have shown remarkable potential as anti-cancer molecules, especially against breast, cervical, colorectal, gastric, lung, and prostate cancer cell lines, as well as leukaemia, melanoma, and hepatocellular carcinoma among others. Recent data has indicated that Tanshinones can modulate multiple molecular pathways such as PI3K/Akt, MAPK and JAK/STAT3, and exert their pharmacological effects against different malignancies. In addition, preclinical and clinical data, together with the safety profile of Tanshinones, encourage further applications of these compounds in cancer therapeutics. In this review article, the effect of Tanshinones on different cancers, challenges in their pharmacological development, and opportunities to harness their clinical potential have been documented.

The antimicrobial peptide tilapia piscidin 3 induces mitochondria-modulated intrinsic apoptosis of osteosarcoma cells

Osteosarcoma (OS) is the most common solid tumor of the bone that most often affects adolescents. The introduction of chemotherapy for the treatment of OS has largely improved the survival rates of patients with localized tumors. However, the 5-year survival rate of OS patients with relapsed or metastatic disease is only 10 to 20%. In this study, the antimicrobial peptide tilapia piscidin 3 (TP3), isolated from Nile tilapia (Oreochromis niloticus), was treated to OS MG63 cells. Our findings showed that TP3 concentration as low as 1 μM induced significant inhibition of cell viability and increased DNA fragmentation, as determined by the MTT and TUNEL assays, respectively. The protein expression levels of cleaved caspases 3/9 were increased. An in situ live-cell time-lapse video and cell tomographic microscopy images showed cellular blebbing, shrinkage, nuclear fragmentation, and chromatin condensation, with the formation of beaded apoptopodia. Moreover, there were significant increase in the production of TP3-induced mitochondrial and cellular reactive oxygen species (ROS), as well as down-regulated mitochondrial oxygen consumption and extracellular acidification rates. Additionally, TP3 enhanced mitochondrial fission, whereas fusion was attenuated. Furthermore, after administration of the mitochondria targeted antioxidant mitoTempo, TP3-induced ROS oxidant levels and alterations in cleaved caspases 3/9 expression were rescued. TP3 promoted mitochondria-modulated intrinsic apoptosis through the induction of ROS production, activation of caspases 3/9, and the down-regulation of mitochondrial oxygen consumption and extracellular acidification rates, suggesting that TP3 has potential as an innovative alternative for OS treatment.

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.

Specific Core-Satellite Nanocarriers for Enhanced Intracellular ROS Generation and Synergistic Photodynamic Therapy

The deficiency of reactive oxygen species (ROS) is the main reason for the current poor efficiency of tumor photodynamic therapy (PDT). To solve this problem, a simple light-triggered core-satellite nanoplatform (UPSD@Au) has been developed by loading Au nanoparticles on the surface of mesoporous silica-coated upconversion nanoparticles. Small molecules DC50 (C₁₇H₁₄BrF₂N₃OS) and photosensitizer (silicon phthalocyanine dihydroxide, SPCD) were loaded into the silica shell to improve ROS production. Meanwhile, PDT can be triggered through facile near-infrared laser irradiation given the occurrence of a moderate photothermal transfer process between upconversion nanoparticles and Au. The reasonable increment in temperature induced by Au resulted in the timely release of DC50. The inhibition of copper transfer by DC50 results in reduced ROS scavenging and thus improves light-triggered ROS accumulation. Notably, the expression levels of the human copper-trafficking proteins Atox1 and CCS in cancerous cells exceed those in normal cells, and thus enhanced ROS accumulation effect was achieved in cancerous cells. In vitro and in vivo results demonstrate that the synergism between DC50 and SPCD coloaded in the UPSD@Au nanoplatform increases the efficiency of PDT. The UPSD@Au platform represents an efficient codelivery method for hydrophobic small molecules and improves sensitization to specific cancer therapy.

Potent Cytotoxicity of Novel L-Shaped Ortho-Quinone Analogs through Inducing Apoptosis

Twenty-seven L-shaped ortho-quinone analogs were designed and synthesized using a one pot double-radical synthetic strategy followed by removing methyl at C-3 of the furan ring and introducing a diverse side chain at C-2 of the furan ring. The synthetic derivatives were investigated for their cytotoxicity activities against human leukemia cells K562, prostate cancer cells PC3, and melanoma cells WM9. Compounds TB1, TB3, TB4, TB6, TC1, TC3, TC5, TC9, TC11, TC12, TC14, TC15, TC16, and TC17 exhibited a better broad-spectrum cytotoxicity on three cancer cells. TB7 and TC7 selectively displayed potent inhibitory activities on leukemia cells K562 and prostate cancer cells PC3, respectively. Further studies indicated that TB3, TC1, TC3, TC7, and TC17 could significantly induce the apoptosis of PC3 cells. TC1 and TC17 significantly induced apoptosis of K562 cells. TC1, TC11, and TC14 induced significant apoptosis of WM9 cells. The structure-activity relationships evaluation showed that removing methyl at C-3 of the furan ring and introducing diverse side chains at C-2 of the furan ring is an effective strategy for improving the anticancer activity of L-shaped ortho-quinone analogs.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

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.

Tanshinone IIA combined with cisplatin synergistically inhibits non-small-cell lung cancer in vitro and in vivo via down-regulating the phosphatidylinositol 3-kinase/Akt signalling pathway

Cisplatin represents one of the first‐line drugs used for non‐small‐cell lung cancer treatment. However, considerable side effects and the emergence of drug resistance are becoming critical limitations to its application. Combinatorial strategies may be able to extend the use of cisplatin. Both Tanshinone IIA and cisplatin inhibit non‐small‐cell lung cancer cell growth in a time‐ and dose‐dependent manner. When Tanshinone IIA was combined with cisplatin at a ratio of 20:1, they were observed to exert a synergistic inhibitory effect on non‐small‐cell lung cancer cells. The combination treatment was shown to impair cell migration and invasion, arrest the cell cycle in the S phases, and induce apoptosis in A549 and PC9 cells in a synergistic manner. KEGG pathway analysis and molecular docking indicated that Tanshinone IIA might mainly influence the phosphatidylinositol 3‐kinase‐Akt signalling pathway. In all treated groups, the expression levels of Bax and cleaved Caspase‐3 were up‐regulated, whereas the expression levels of Bcl‐2, Caspase‐3, p‐Akt, and p‐PI3K proteins were down‐regulated. Among these, the combination of Tan IIA and cisplatin exhibited the most significant difference. Tanshinone IIA may function as a novel option for combination therapy for non‐small‐cell lung cancer treatment.

HGK-sestrin 2 signaling-mediated autophagy contributes to antitumor efficacy of Tanshinone IIA in human osteosarcoma cells

Tanshinone IIA (TIIA) is a diterpenoid naphthoquinone isolated from the herb Salvia miltiorrhiza with antitumor effects manifested at multiple levels that are mechanistically obscure. In our previous studies, we illustrated that TIIA treatment triggered apoptosis in human osteosarcoma 143B cells both in vitro and in vivo, accompanied with mitochondrial dysfunction. Importantly, the overall survival rate of patients with osteosarcoma who were randomly recruited to S. miltiorrhiza treatment was significantly higher than those without. Pursuing this observation, we evaluated the potential effect of TIIA on autophagy induction in osteosarcoma both in vivo and in vitro. We discovered that TIIA inhibited osteosarcoma cell survival through class I PI3K and Akt signaling pathways. In contrast, expression of class III PI3K required in the early stages of autophagosome generation was predominantly enhanced by TIIA treatment. Our study indicated that treatment of TIIA effectively induced autophagy in human osteosarcoma cells, which contributed to the blockade of anchorage-independent growth of osteosarcoma cells and ameliorated tumor progression in NOD/SCID mice. We demonstrated that TIIA-mediated autophagy occurred in a sestrin 2 (SESN2)-dependent but not Beclin 1-dependent manner. In addition, we defined the activation of HGK (MAP4K4 or mitogen-activated protein kinase kinase kinase kinase)/SAPK/JNK1/Jun kinase pathways in upregulating transcription of SESN2, in which TIIA triggered HGK/JNK1-dependent Jun activation and led to increased Jun recruitment to AP-1-binding site in the SESN2 promoter region. Our results offer novel mechanistic insight into how TIIA inhibits osteosarcoma growth and suggest TIIA as a promising therapeutic agent for the treatment of cancer.

Tanshinone IIA Attenuates Insulin Like Growth Factor 1 -Induced Cell Proliferation in PC12 Cells through the PI3K/Akt and MEK/ERK Pathways

The insulin like growth factor 1 (IGF-1) and its receptor (IGF-1R) facilitate tumor proliferation and progression. Tanshinone IIA (TSN) is an active diterpene quinone isolated from the roots of the herbal plant Salvia miltiorrhiza. TSN inhibits the proliferation of various types of cancer cells but its role in the IGF-1R-induced proliferation of pheochromocytoma (PC12) cells and the potential mechanisms are largely unknown. This study aims to investigate the anti-proliferative effect of TSN in PC12 cells and its role on IGF-1R signaling transduction. PC12 cells were treated with IGF-1 with or without TSN, methyl thiazolytetrazolium (MTT) assay, and cell counting kit-8 and flow cytometry were used to evaluate the proliferation of PC12 cells. The role of TSN on the apoptosis of PC12 cells were detected by flow cytometry as well. The effects of TSN and IGF-1 on the phosphorylation of IGF-1R, protein kinase B (Akt), extracellular-signal related kinase 1/2 (ERK1/2) and other downstream targets were analyzed by Western blotting analysis. Our results showed that IGF-1 promoted the growth of PC12 cells in a dose-dependent manner and increased the phosphorylation of IGF-1R, whereas TSN attenuated the effect of IGF-1. Interestingly, TSN did not induce cell apoptosis in PC12 cells. Moreover, TSN attenuated the phosphorylation of Akt and ERK1/2 induced by IGF-1, and the phosphorylation of glycogen synthase kinase-3β, forkhead box O3a (FOXO3a) and c-Raf were also inhibited by TSN. Furthermore, TSN inhibited cell growth induced by IGF-1 and blocked the activation of IGF-1R in SH-SY5Y cells. Taken together, TSN has an inhibitory effect on the proliferation of PC12 cells via down-regulation of the phosphorylated IGF-1R and its downstream signaling.

Tanshinone IIA regulates colorectal cancer apoptosis via attenuation of Parkin‑mediated mitophagy by suppressing AMPK/Skp2 pathways

Mitophagy is important for cancer development. Notably, the role of Parkin‑mediated mitophagy in colorectal cancer (CRC) mortality has not been fully determined. Therefore, the present study aimed to investigate the effect of Parkin‑mediated mitophagy on CRC apoptosis. In addition, the present study investigated the therapeutic effects of Tanshinone IIA (Tan IIA) on the regulation of CRC cell death via mitophagy. Cellular apoptosis was measured following Tan IIA treatment. In addition, mitophagy activity was evaluated by immunofluorescence and western blotting. The results of the present study revealed that Tan IIA may enhance CRC cell death. In addition, the results demonstrated that Tan IIA enhanced mitochondrial apoptosis, as demonstrated by reduced mitochondrial membrane potential, elevated mitochondrial permeability transition pore opening, and increased oxidative stress, mitochondrial energy disorder and proapoptotic factor expression. Furthermore, the results of the present study demonstrated that Tan IIA induced mitochondrial apoptosis via inhibition of mitophagy. In addition, it was revealed that mitophagy could suppress mitochondrial apoptosis. Functional assays revealed that Tan IIA suppressed the adenosine monophosphate‑activated protein kinase (AMPK) pathway, resulting in the inactivation of S‑phase kinase associated protein 2 (Skp2). Furthermore, reduced levels of Skp2 failed to activate Parkin, thus resulting in inhibition of mitophagy. Conversely, reactivation of AMPK and overexpression of Skp2 rescued mitophagy activity and thus attenuated the Tan IIA‑induced apoptosis of CRC cells. In conclusion, the results of the present study demonstrated the beneficial role of mitophagy in CRC cell survival and suggested that Tan IIA may be an effective therapeutic agent, which suppresses mitophagy activity and enhances CRC apoptosis.

Targeting VEGF/VEGFRs Pathway in the Antiangiogenic Treatment of Human Cancers by Traditional Chinese Medicine

Bearing in mind the doctrine of tumor angiogenesis hypothesized by Folkman several decades ago, the fundamental strategy for alleviating numerous cancer indications may be the strengthening application of notable antiangiogenic therapies to inhibit metastasis-related tumor growth. Under physiological conditions, vascular sprouting is a relatively infrequent event unless when specifically stimulated by pathogenic factors that contribute to the accumulation of angiogenic activators such as the vascular endothelial growth factor (VEGF) family and basic fibroblast growth factor (bFGF). Since VEGFs have been identified as the principal cytokine to initiate angiogenesis in tumor growth, synthetic VEGF-targeting medicines containing bevacizumab and sorafenib have been extensively used, but prominent side effects have concomitantly emerged. Traditional Chinese medicines (TCM)–derived agents with distinctive safety profiles have shown their multitarget curative potential by impairing angiogenic stimulatory signaling pathways directly or eliciting synergistically therapeutic effects with anti-angiogenic drugs mainly targeting VEGF-dependent pathways. This review aims to summarize (a) the up-to-date understanding of the role of VEGF/VEGFR in correlation with proangiogenic mechanisms in various tissues and cells; (b) the elaboration of antitumor angiogenesis mechanisms of 4 representative TCMs, including Salvia miltiorrhiza, Curcuma longa, ginsenosides, and Scutellaria baicalensis; and (c) circumstantial clarification of TCM-driven therapeutic actions of suppressing tumor angiogenesis by targeting VEGF/VEGFRs pathway in recent years, based on network pharmacology.

Synergistic antitumor effects of tanshinone IIA and sorafenib or its derivative SC-1 in hepatocellular carcinoma cells

Introduction

Hepatocellular carcinoma (HCC) is the most common form of hepatic malignancy in the world. We aimed to determine the effect of tanshinone IIA (Tan-IIA) in combination with sorafenib or its derivative SC-1 on cytotoxicity, apoptosis, and metastasis in human HCC cells.

Materials and methods

Cytotoxicity was detected by MTT assay. Apoptosis and sub-G1 populations were analyzed by flow cytometry. Cell migration and invasion were evaluated by Transwell assay. Protein expression was detected by Western blot.

Results

Tan-IIA combined with sorafenib or SC-1 exerted synergistic cytotoxicity in HCC cells. Elevated proportions of sub-G1 and caspase activation were observed in the combinative treatments; in addition, marked inhibition of cell migration and invasion, which could be mediated by the modulation of epithelial–mesenchymal transition was observed. pSTAT3 levels were significantly reduced as well.

Conclusion

A combination therapy using Tan-IIA and sorafenib or SC-1 could be a promising approach to target HCC, and further preclinical investigations are warranted to establish their synergetic advantage.

The effects of Curcumin on HCT-116 cells proliferation and apoptosis via the miR-491/PEG10 pathway

Paternally expressed gene-10 (PEG10) could participate in several carcinomas and might be regulated by miR-491. To now, miR-491 was found to play an important role in the sensitivity and mechanism of drug usage in the treatment of colorectal cancer, and drug resistance is a key factor to affect the disease healing. In this study, miR-491, PEG10, Wnt1, and β-catenin expression levels and their correlation with colorectal cancer were assessed in cancer tissues and adjacent parts. And the target relationship between PEG10 and miR-491 was verified. Meanwhile, the impaction of Curcumin on miR-491, PEG10, and Wnt/β-catenin signaling pathway were analyzed in HCT-116 cells. The effects of PEG10 and Curcumin on human HCT-116 cells proliferation and apoptosis were investigated by MTT and flow cytometry assay. Results showed that the expression of miR-491 in colon cancer tissues was decreased, but PEG10, Wnt1, and β-catenin were higher than that in adjacent tissues. The PEG10 gene 3' UTR could combine with miR-491 seed sequence and miR-491 overexpression could cause a decrease in PEG10, Wnt1, and β-catenin levels in human HCT-116 cells. Furthermore, PEG10 overexpression increased the expression levels of Wnt1 and β-catenin, thereby promoting cell proliferation and inhibiting apoptosis. In addition, Curcumin could up-regulate miR-491, inhibit PEG10, and Wnt/β-catenin signaling pathway. Consequently, Curcumin reduced HCT-116 cells proliferation and promoted cells apoptosis via the miR-491/PEG10 pathway. In conclusion, PEG10 was a target gene of miR-491, miR-491/PEG10 strengthen the sensitivity of Curcumin in HCT-116 cells proliferation and apoptosis, which might act as an ideal diagnostic biomarker treatment methods.

Mitochondrial Dynamics in Type 2 Diabetes and Cancer

Mitochondria are bioenergetic, biosynthetic, and signaling organelles that control various aspects of cellular and organism homeostasis. Quality control mechanisms are in place to ensure maximal mitochondrial function and metabolic homeostasis at the cellular level. Dysregulation of these pathways is a common theme in human disease. In this mini-review, we discuss how alterations of the mitochondrial network influences mitochondrial function, focusing on the molecular regulators of mitochondrial dynamics (organelle's shape and localization). We highlight similarities and critical differences in the mitochondrial network of cancer and type 2 diabetes, which may be relevant for treatment of these diseases.

Tanshinone IIA inhibits angiogenesis in human endothelial progenitor cells in vitro and in vivo

Accumulating evidence reports that bone marrow-derived endothelial progenitor cells (EPCs) regulate angiogenesis, postnatal neovascularization and tumor metastasis. It has been suggested that understanding the molecular targets and pharmacological functions of natural products is important for novel drug discovery. Tanshinone IIA is a major diterpene quinone compound isolated from Danshen (Salvia miltiorrhiza) and is widely used in traditional Chinese medicine (TCM). Evidence indicates that tanshinone IIA modulates angiogenic functions in human umbilical vein endothelial cells. However, the anti-angiogenic activity of tanshinone IIA in human EPCs has not been addressed. Here, we report that tanshinone IIA dramatically suppresses vascular endothelial growth factor (VEGF)-promoted migration and tube formation of human EPCs, without cytotoxic effects. We also show that tanshinone IIA markedly inhibits VEGF-induced angiogenesis in the chick embryo chorioallantoic membrane (CAM) model. Importantly, tanshinone IIA significantly attenuated microvessel formation and the expression of EPC-specific markers in the in vivo Matrigel plug assay in mice. Further, we found that tanshinone IIA inhibits EPC angiogenesis through the PLC, Akt and JNK signaling pathways. Our report is the first to reveal that tanshinone IIA reduces EPC angiogenesis both in vitro and in vivo. Tanshinone IIA is a promising natural product worthy of further development for the treatment of cancer and other angiogenesis-related pathologies.

Tanshinone IIA induces apoptosis via inhibition of Wnt/β‑catenin/MGMT signaling in AtT‑20 cells

A strategy to suppress the expression of the DNA repair enzyme O6‑methylguanine‑DNA methyltransferase (MGMT) by inhibition of Wnt/β‑catenin signaling may be useful as a novel treatment for pituitary adenoma. Previous studies have reported that Tanshinone IIA (TSA), a major quinone compound isolated from Salvia miltiorrhiza, had antitumor effects. However, whether TSA has antitumor effects against pituitary adenoma and whether the mechanisms are associated with the Wnt/β‑catenin/MGMT pathway remains to be clarified. In the present study, TSA treatment caused apoptosis in AtT‑20 cells in a concentration‑dependent manner, as demonstrated by cell viability reduction, phophatidylserine externalization detected by Annexin V staining and mitochondrial membrane potential disruption detected by JC‑1 staining, which were associated with activation of caspase‑3 and DNA fragmentation detected by TUNEL in AtT‑20 cells. T‑cell factor (TCF)‑lymphoid‑enhancing factor (LEF) reporter activity was determined by dual luciferase reporter assay and the interaction between β‑catenin and TCF‑4 were detected using a co‑immunoprecipitation kit. The results indicated TSA treatment increased β‑catenin phosphorylation, inhibited β‑catenin nuclear translocation, reduced β‑catenin/TCF‑4 complex formation and TCF‑LEF luciferase reporter activity, and subsequently reduced the expression of cyclin D1 and MGMT. Notably, overexpression of MGMT in β‑catenin knock down AtT‑20 cells abrogated the TSA‑mediated effects in AtT‑20 cells. In conclusion, TSA induced apoptosis via inhibition of Wnt/β‑catenin‑dependent MGMT expression, which may provide novel insights into the understanding of the mechanism of the antitumor effects of Salvia miltiorrhiza.

Tanshinone IIA Inhibits Epithelial-Mesenchymal Transition in Bladder Cancer Cells via Modulation of STAT3-CCL2 Signaling

Tanshinone IIA (Tan-IIA) is an extract from the widely used traditional Chinese medicine (TCM) Danshen (Salvia miltiorrhiza), and has been found to attenuate the proliferation of bladder cancer (BCa) cells (The IC₅₀ were: 5637, 2.6 μg/mL; BFTC, 2 μg/mL; T24, 2.7 μg/mL, respectively.). However, the mechanism of the effect of Tan-IIA on migration inhibition of BCa cells remains unclear. This study investigates the anti-metastatic effect of Tan-IIA in human BCa cells and clarifies its molecular mechanism. Three human BCa cell lines, 5637, BFTC and T24, were used for subsequent experiments. Cell migration and invasion were evaluated by transwell assays. Real-time RT-PCR and western blotting were performed to detect epithelial-mesenchymal transition (EMT)-related gene expression. The enzymatic activity of matrix metalloproteinases (MMP) was evaluated by zymography assay. Tan-IIA inhibited the migration and invasion of human BCa cells. Tan-IIA suppressed both the protein expression and enzymatic activity of MMP-9/-2 in human BCa cells. Tan-IIA up-regulated the epithelial marker E-cadherin and down-regulated mesenchymal markers such as N-cadherin and Vimentin, along with transcription regulators such as Snail and Slug in BCa cells in a time- and dose-dependent manner. Mechanism dissection revealed that Tan-IIA-inhibited BCa cell invasion could function via suppressed chemokine (C-C motif) ligand 2 (CCL2) expression, which could be reversed by the addition of CCL2 recombinant protein. Furthermore, Tan-IIA could inhibit the phosphorylation of the signal transducer and activator of transcription 3 (STAT3) (Tyr705), which cannot be restored by the CCL2 recombinant protein addition. These data implicated that Tan-IIA might suppress EMT on BCa cells through STAT3-CCL2 signaling inhibition. Tan-IIA inhibits EMT of BCa cells via modulation of STAT3-CCL2 signaling. Our findings suggest that Tan-IIA can serve as a potential anti-metastatic agent in BCa therapy.