Sinomenine prevents metastasis of human osteosarcoma cells via S phase arrest and suppression of tumor-related neovascularization and osteolysis through the CXCR4-STAT3 pathway

Novel Products as Promising Therapeutic Agents for Angiogenesis Inhibition

OBJECTIVE

Angiogenesis is the process of forming new blood vessels from pre-existing vessels and occurs during development, wound healing, and tumor growth. In this review, we aimed to present a comprehensive view of various factors contributing to angiogenesis during carcinogenesis. Anti-angiogenesis agents prevent or slow down cancer growth by interrupting the nutrients and blood supply to the tumor cells, and thus can prove beneficial for treatment.

METHOD

The discovery of several novel angiogenic inhibitors has helped to reduce both morbidity and mortality from several life-threatening diseases, such as carcinomas. There is an urgent need for a new comprehensive treatment strategy combining novel anti-angiogenic agents for the control of cancer. The article contains details of various angiogenic inhibitors that have been adopted by scientists to formulate and optimize such systems in order to make them suitable for cancer.

RESULTS

The results of several researches have been summarized in the article and all of the data support the claim that anti-angiogenic agent is beneficial for cancer treatment.

CONCLUSION

This review focuses on novel antiangiogenic agents that play a crucial role in controlling carcinogenesis.

Targeted anti-angiogenesis therapy for advanced osteosarcoma

To date, despite extensive research, the prognosis of advanced osteosarcoma has not improved significantly. Thus, patients experience a reduced survival rate, suggesting that a reevaluation of current treatment strategies is required. Recently, in addition to routine surgery, chemotherapy and radiotherapy, researchers have explored more effective and safer treatments, including targeted therapy, immunotherapy, anti-angiogenesis therapy, metabolic targets therapy, and nanomedicine therapy. The tumorigenesis and development of osteosarcoma is closely related to angiogenesis. Thus, anti-angiogenesis therapy is crucial to treat osteosarcoma; however, recent clinical trials found that it has insufficient efficacy. To solve this problem, the causes of treatment failure and improve treatment strategies should be investigated. This review focuses on summarizing the pathophysiological mechanisms of angiogenesis in osteosarcoma and recent advances in anti-angiogenesis treatment of osteosarcoma. We also discuss some clinical studies, with the aim of providing new ideas to improve treatment strategies for osteosarcoma and the prognosis of patients.

Crosstalk between CXCL12/CXCR4/ACKR3 and the STAT3 Pathway

The reciprocal modulation between the CXCL12/CXCR4/ACKR3 axis and the STAT3 signaling pathway plays a crucial role in the progression of various diseases and neoplasms. Activation of the CXCL12/CXCR4/ACKR3 axis triggers the STAT3 pathway through multiple mechanisms, while the STAT3 pathway also regulates the expression of CXCL12. This review offers a thorough and systematic analysis of the reciprocal regulatory mechanisms between the CXCL12/CXCR4/ACKR3 signaling axis and the STAT3 signaling pathway in the context of diseases, particularly tumors. It explores the potential clinical applications in tumor treatment, highlighting possible therapeutic targets and novel strategies for targeted tumor therapy.

Synthesis of sinomenine derivatives with potential anti-leukemia activity

In recent years, with sinomenine hydrochloride as the main ingredient, Qingfengteng had been formulated as various dosage forms for clinical treatment. Subsequent findings confirmed a variety of biological roles for sinomenine. Here, 15 H2S-donating sinomenine derivatives were synthesized. Target hybrids a11 displayed substantial cytotoxic effects on cancer cell lines, particularly against K562 cells, with an IC50 value of 1.36 μM. In-depth studies demonstrated that a11 arrested cell cycle at G1 phase, induced apoptosis via both morphological changes in nucleus and membrane potential collapse in mitochondria. These results indicated a11 exerted an antiproliferative effect through apoptosis induction via mitochondrial pathway.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Bioactivities and Mechanisms of Action of Sinomenine and Its Derivatives: A Comprehensive Review

Sinomenine, an isoquinoline alkaloid extracted from the roots and stems of Sinomenium acutum, has been extensively studied for its derivatives as bioactive agents. This review concentrates on the research advancements in the biological activities and action mechanisms of sinomenine-related compounds until November 2023. The findings indicate a broad spectrum of pharmacological effects, including antitumor, anti-inflammation, neuroprotection, and immunosuppressive properties. These compounds are notably effective against breast, lung, liver, and prostate cancers, exhibiting IC50 values of approximately 121.4 nM against PC-3 and DU-145 cells, primarily through the PI3K/Akt/mTOR, NF-κB, MAPK, and JAK/STAT signaling pathways. Additionally, they manifest anti-inflammatory and analgesic effects predominantly via the NF-κB, MAPK, and Nrf2 signaling pathways. Utilized in treating rheumatic arthritis, these alkaloids also play a significant role in cardiovascular and cerebrovascular protection, as well as organ protection through the NF-κB, Nrf2, MAPK, and PI3K/Akt/mTOR signaling pathways. This review concludes with perspectives and insights on this topic, highlighting the potential of sinomenine-related compounds in clinical applications and the development of medications derived from natural products.

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.

Discovery of sinomenine/8-Bis(benzylthio)octanoic acid hybrids as potential anti-leukemia drug candidate via mitochondrial pathway

Traditional Chinese medicine Qingfengteng primarily acquired from the dried canes of Sinomenium acutum (Thunb.) Rehd. et Wils. var. cinereum Rehd. et Wils. and S. acutum (Thunb.) Rehd. et Wils. For the therapeutic treatment of rheumatism, acute arthritis, and rheumatoid arthritis based on Qingfengteng, sinomenine hydrochloride was recently made the principal active ingredient in various dosage forms. 8-Bis(benzylthio)octanoic acid (CPI-613) was an orphan medicine that the FDA and EMA approved orphan for the treatment of certain resistant malignancies. Its unique mode of action and minimal toxicity toward normal tissues made for an apt pharmacophore. In order to expand the field of sinomenine anticancer structures, sinomenine/8-Bis(benzylthio)octanoic acid derivatives were designed and synthesized. Among them, target hybrids e4 stood out for having notable cytotoxic effects against cancer cell lines, especially for K562 cells, with IC50 values of 2.45 μM and high safety. In-depth investigations demonstrated that e4 caused apoptosis by stopping the cell cycle at G1 phase, and doing so by altering the morphology of the nucleus and causing membrane potential of the in mitochondria to collapse. These results indicated e4 exerted an antiproliferative effect through apoptosis induction via mitochondrial pathway.

Anti-cancer effect of palmatine through inhibition of the PI3K/AKT pathway in canine mammary gland tumor CMT-U27 cells

Canine mammary gland tumors (CMTs) are the most common and lethal cancers in female dogs. Dysregulated phosphoinositide 3-kinases (PI3K)/AKT pathway reportedly was involved in the growth and metastasis of CMTs. However, there are few studies on therapeutic strategies for targeting the PI3K pathway in CMTs. In this study, we aimed to determine whether palmatine, a natural isoquinoline alkaloid with anti-cancer properties, could inhibit the growth of CMTs and whether the inhibitory effect was mediated through the PI3K/AKT pathway. Our in vitro experiments on CMT-U27, a CMT cell line, showed that palmatine reduced cell proliferation and induced cell death. Western blotting results revealed that palmatine decreased the protein expression of PI3K, PTEN, AKT, and mechanistic target of rapamycin in the PI3K/AKT pathway, which was supported by the results of immunocytochemistry. Additionally, palmatine suppressed the migration and tube formation of canine aortic endothelial cells as well as the migration of CMT U27 cells. Our in vivo results showed that palmatine inhibited tumor growth in a CMT-U27 mouse xenograft model. We observed a decreased expression of proteins in the PI3K/AKT pathway in tumor tissues, similar to the in vitro results. Furthermore, palmatine significantly disrupted the tumor vasculature and inhibited metastasis to adjacent lymph nodes. In conclusion, our findings demonstrate that palmatine exerts anti-cancer effects against CMTs by inhibiting PI3K/AKT signaling pathway, suggesting that palmatine has potential as a canine-specific PI3K inhibitor for the treatment of CMTs.

Chemistry and biology of ent-morphinan alkaloids

Morphinan alkaloids have attracted constant attention since the isolation of morphine by Sertürner in 1805. However, a group of 45 compounds possessing a complete ent-morphinan backbone can also be found in the literature. These compounds are related to the morphinandienone subgroup and display a substitution pattern which is different from the morphinans. In particular, these alkaloids could be substituted at position C-2 and C-8 either by a hydroxy function or a methoxy moiety. Four groups of ent-morphinan alkaloids can be proposed, the salutaridine, pallidine, cephasugine and erromangine series. Interestingly, the botanical distribution of the ent-morphinans is more widespread than for the morphinans and includes the Annonaceae, Berberidaceae, Euphorbiaceae, Fumariaceae, Hernandiaceae, Lauraceae, Menispermaceae, Monimiaceae, Papaveraceae, and Ranunculaceae families. To date, their exact mode of production remains elusive and their interplay with the biosynthetic pathway of other classes of benzyltetrahydroisoquinoline alkaloids, in particular aporphines, should be confirmed. Exploration of the biological and therapeutic potential of these compounds is limited to some areas, namely central nervous system (CNS), inflammation, cancer, malaria and viruses. Further studies should be conducted to identify the cellular/molecular targets in view of promoting these compounds as new scaffolds in medicinal chemistry.

Isoquercitrin restrains the proliferation and promotes apoptosis of human osteosarcoma cells by inhibiting the Wnt/β-catenin pathway

Currently, chemotherapeutic drugs are widely used for the treatment of osteosarcoma. However, many of these drugs exhibit shortcomings such as poor efficacy, high toxicity, and tolerance. Isoquercitrin (ISO) is a traditional Chinese medicine that has been proved to exert good therapeutic effects on various tumors; however, its role in osteosarcoma has not been reported. Here, we observed that ISO exerted a marked inhibitory effect on the occurrence and development of osteosarcoma in a time- and dose-dependent manner. First, we determined that ISO significantly inhibited proliferation, induced EMT-related migration and invasion and induced apoptosis of osteosarcoma cells in vitro. Concurrently, we also observed that both β-catenin and its downstream genes (c-Myc, CyclinD1, and Survivin) were significantly down-regulated. To verify if the anti-tumor effect of ISO was related to the Wnt/β-catenin signaling pathway, we altered the protein expression level of β-catenin using recombinant lentivirus, then we observed that the effects of ISO on the proliferation, metastasis, and apoptosis of osteosarcoma cells were significantly reversed. Additionally, we used a nude mouse xenograft model and observed that ISO significantly inhibited the growth of osteosarcoma and improved the survival rate of the animal models. In conclusion, this study demonstrates that ISO can exert anti-tumor effects in part by inhibiting the Wnt/β-catenin signaling pathway, thus providing a new potential therapeutic strategy for the treatment of osteosarcoma.

Anti-breast cancer sinomenine derivatives via mechanisms of apoptosis induction and metastasis reduction

Sinomenine, a morphinane-type isoquinoline-derived alkaloid, was first isolated from stems and roots of Sinomenium diversifolius (Miq.) in 1920. Later discovery by researchers confirmed various essential biological efficacy sinomenine exerted in vitro and in vivo. In this study, a series of 15 sinomenine/furoxan hybrid compounds were designed and synthesised in search of a TNBC drug candidate. Some of the target compounds exhibited strong antiproliferative activities against cancer cell lines, especially for TNBC cells, compared to positive controls. Among them, hybrid 7Cc exerted superior cytotoxic effects on cancer cell lines with exceptionally low IC₅₀ (0.82 μM) against MDA-MB-231 cells with the highest safety index score. Further studies in mechanism displayed that 7Cc could induce an S phase cell cycle arrest, stimulate apoptosis in MDA-MB-231 cells, disrupt mitochondrial membrane potential and exert a genotoxic effect on DNA in cancer cells. In addition, 7Cc also notably inhibited MDA-MB-231 cells in both migration, invasion and adhesion.

Baicalin induces apoptosis and autophagy in human osteosarcoma cells by increasing ROS to inhibit PI3K/Akt/mTOR, ERK1/2 and β-catenin signaling pathways

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Baicalin causes apoptosis and autophagy through accumulating ROS to suppress PI3K/Akt/mTOR, ERK1/2 and β-catenin pathways in OS cells.

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Baicalin-induced autophagosome further triggers apoptosis.

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Baicalin-induced ROS and Ca²⁺ interactions induce apoptosis.

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Baicalin molecule targets PI3Kγ, inhibiting downstream effectors AKT and mTOR.

Baicalin, a flavonoid derivative, exerts antitumor activity in a variety of neoplasms. However, whether baicalin exerts antitumor effects on osteosarcoma cells remains to be elucidated. In this study, treatment with baicalin reduced the proliferation and invasive potential of osteosarcoma cells and reduced the mitochondrial membrane potential, which eventually caused mitochondrial apoptosis. In addition, baicalin increased intercellular Ca²⁺ and ROS concentrations. Baicalin-induced apoptosis was confirmed by enhanced Bax, cleaved caspase-3, and cleaved PARP levels and decreased Bcl-2 levels. The increase in LC3-II and p62 suggested that baicalin induced autophagosome formation but ultimately inhibited downstream autophagy. Moreover, apoptosis induced by baicalin was attenuated by the addition of 3-MA. Furthermore, we found that baicalin inhibited the PI3K/Akt/mTOR, ERK1/2 and β-catenin signaling pathways. Chelation of free Ca²⁺ by BAPTA-AM also inhibited both apoptosis induction and ROS concentration changes. Finally, NAC pretreatment reversed baicalin treatment outcomes, including the increase in Ca²⁺ concentration, induction of apoptosis and autophagy, and inhibition of the pathways. Molecular docking results indicated that baicalin might interact with the structural domain of PI3Kγ. Thus, baicalin may be considered a potential candidate for osteosarcoma treatment.

Sinomenine Inhibits Vasculogenic Mimicry and Migration of Breast Cancer Side Population Cells via Regulating miR-340-5p/SIAH2 Axis

Hypoxia and its induced vasculogenic mimicry (VM) formation, which both closely related with stem-like side population (SP) cells, are the main culprits leading to tumor invasion and metastasis. Sinomenine exhibits excellent anticancer activity in breast cancer, but whether and how it affects hypoxia-triggered VM formation in breast cancer SP cells remains unclear. In this study, breast cancer SP cells were sorted from MDA-MB-231 cells and cultured with sinomenine under hypoxic conditions. Sinomenine obviously repressed the migration and VM formation of breast cancer SP cells. Through downregulating SIAH2 and HIF-1α, sinomenine can inhibit epithelial-mesenchymal transition process of breast cancer SP cells. SIAH2 was identified as a target of miR-340-5p and was downregulated by it, and sinomenine can upregulate miR-340-5p. Hypoxia-induced downregulation of miR-340-5p and activation of SIAH2/HIF-1α pathway can be both counteracted by the sinomenine. Moreover, miR-340-5p inhibition and SIAH2 overexpression can partly counteract the anticancer effects of sinomenine. Taken together, sinomenine inhibits hypoxia-caused VM formation and metastasis of breast cancer SP cells by regulating the miR-340-5p/SIAH2 axis.

Natural Products: A Promising Therapeutics for Targeting Tumor Angiogenesis

Tumor-associated angiogenesis is a key target for anti-cancer therapy. The imbalance between pro-angiogenic and anti-angiogenic signals elicited by tumor cells or tumor microenvironment always results in activating "angiogenic switch". Tumor angiogenesis functions in multi-aspects of tumor biology, including endothelial cell apoptosis, tumor metastasis, and cancer stem cell proliferation. Numerous studies have indicated the important roles of inexpensive and less toxic natural products in targeting tumor angiogenesis-associated cytokines and apoptotic signaling pathways. Our current knowledge of tumor angiogenesis is based mainly on experiments performed on cells and animals, so we summarized the well-established models for angiogenesis both in vitro and in vivo. In this review, we classified and summarized the anti-angiogenic natural agents (Polyphenols, Polysaccharides, Alkaloids, Terpenoids, Saponins) in targeting various tumor types according to their chemical structures at present, and discussed the mechanistic principles of these natural products on regulating angiogenesis-associated cytokines and apoptotic signaling pathways. This review is to help understanding the recent progress of natural product research for drug development on anti-tumor angiogenesis.

Sinomenine Suppresses Development of Hepatocellular Carcinoma Cells via Inhibiting MARCH1 and AMPK/STAT3 Signaling Pathway

Promotion of apoptosis and suppression of proliferation in tumor cells are popular strategies for developing anticancer drugs. Sinomenine (SIN), a plant-derived alkaloid, displays antitumor activity. However, the mechanism of action of SIN against hepatocellular carcinoma (HCC) is unclear. Herein, several molecular technologies, such as Western Blotting, qRT-PCR, flow cytometry, and gene knockdown were applied to explore the role and mechanism of action of SIN in the treatment of HCC. It was found that SIN arrests HCC cell cycle at G0/G1 phase, induces apoptosis, and suppresses proliferation of HCC cells via down-regulating the expression of membrane-associated RING-CH finger protein 1 (MARCH1). Moreover, SIN induces cell death and growth inhibition through AMPK/STAT3 signaling pathway. MARCH1 expression was silenced by siRNA to explore its involvement in the regulation of AMPK/STAT3 signaling pathway. Silencing MARCH1 caused down-regulation of phosphorylation of AMPK, STAT3 and decreased cell viability and function. Our results suggested that SIN inhibits proliferation and promotes apoptosis of HCC cells by MARCH1-mediated AMPK/STAT3 signaling pathway. This study provides new support for SIN as a clinical anticancer drug and illustrates that targeting MARCH1 could be a novel treatment strategy in developing anticancer therapeutics.

STAT3 and its targeting inhibitors in osteosarcoma

Signal transducer and activator of transcription 3 (STAT3) is one of seven STAT family members involved with the regulation of cellular growth, differentiation and survival. STAT proteins are conserved among eukaryotes and are important for biological functions of embryogenesis, immunity, haematopoiesis and cell migration. STAT3 is widely expressed and located in the cytoplasm in an inactive form. STAT3 is rapidly and transiently activated by tyrosine phosphorylation by a range of signalling pathways, including cytokines from the IL‐6 family and growth factors, such as EGF and PDGF. STAT3 activation and subsequent dimer formation initiates nuclear translocation of STAT3 for the regulation of target gene transcription. Four STAT3 isoforms have been identified, which have distinct biological functions. STAT3 is considered a proto‐oncogene and constitutive activation of STAT3 is implicated in the development of various cancers, including multiple myeloma, leukaemia and lymphomas. In this review, we focus on recent progress on STAT3 and osteosarcoma (OS). Notably, STAT3 is overexpressed and associated with the poor prognosis of OS. Constitutive activation of STAT3 in OS appears to upregulate the expression of target oncogenes, leading to OS cell transformation, proliferation, tumour formation, invasion, metastasis, immune evasion and drug resistance. Taken together, STAT3 is a target for cancer therapy, and STAT3 inhibitors represent potential therapeutic candidates for the treatment of OS.

Sinomenine Inhibits Migration and Invasion of Human Lung Cancer Cell through Downregulating Expression of miR-21 and MMPs

Sinomenine is an alkaloid derived from Sinomenium acutum. Recent studies have found that sinomenine can inhibit various cancers by inhibiting the proliferation, migration and invasion of tumors and inducing apoptosis. This study aims to investigate the effect and mechanism of sinomenine on inhibiting the migration and invasion of human lung adenocarcinoma cells in vitro. The results demonstrate that viabilities of A549 and H1299 cells were inhibited by sinomenine in a dose-dependent manner. When treated with sub-toxic doses of sinomenine, cell migration and invasion are markedly suppressed. Sinomenine decreases the mRNA level of matrix metalloproteinase-2 (MMP-2), MMP-9, and the extracellular inducer of matrix metalloproteinase (EMMPRIN/CD147), but elevates the expression of reversion-inducing cysteine-rich proteins with kazal motifs (RECK) and the tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2. In addition, sinomenine significantly increases the expression of the epithelial marker E-cadherin but concomitantly decreases the expression of the mesenchymal marker vimentin, suggesting that it suppresses epithelial–mesenchymal transition (EMT). Moreover, sinomenine downregulates oncogenic microRNA-21 (miR-21), which has been known to target RECK. The downregulation of miR-21 decreases cell invasion, while the upregulation of miR-21 increases cell invasion. Furthermore, the downregulation of miR-21 stimulates the expression of RECK, TIMP-1/-2, and E-cadherin, but reduces the expression of MMP-2/-9, EMMPRIN/CD147, and vimentin. Taken together, the results reveal that the inhibition of A549 cell invasion by sinomenine may, at least in part, be through the downregulating expression of MMPs and miR-21. These findings demonstrate an attractive therapeutic potential for sinomenine in lung cancer anti-metastatic therapy.

Clinical Significance of Cancer Stem Cell Markers CD133 and CXCR4 in Osteosarcomas

Objective:

Osteosarcomas (OS) is one the most common primary bone malignancy in humans with the lungs metastasis in most cases. Metastasis and recurrence of OS is attributed to cancer stem cells (CSCs). Our study aimed to evaluate the clinical significance of CD133 and C-X-C chemokine receptor type 4 (CXCR4) as the frequently applied markers for CSCs in OS patients.

Methods:

In this cross-sectional, a total of 50 tissue samples from the patients with primary OS were immunohistochemically examined to detect the expression of CD133 and CXCR4. The associations of the relative expression and clinical significance of each marker were also evaluated.

Results:

High level expression of CD133 was detected in 26% of OS patient tissues. Of the 12 patients who showed lung metastasis, 5 cases showed high expression of CD133 with marginal trend correlation (P=0.06). No significant correlation was observed between CD133 expression and clinicopathological factors. Only 36% of cases showed CXCR4 expression which was not significantly correlated with gender, age, tumor size, necrosis, stage and metastasis (P>0.05). Clinically, patients with concomitant CD133/CXCR4 expression had significant association with lung metastasis (P=0.05).

Conclusion:

Our findings showed that concomitant expression of CSC markers CD133/CXCR4 might had a synergistic effect on the OS poor prognosis. These markers could be considered as potential therapeutic candidates of OS targeted therapy.

Repurposing of plant alkaloids for cancer therapy: Pharmacology and toxicology

Drug repurposing (or repositioning) is an emerging concept to use old drugs for new treatment indications. Phytochemicals isolated from medicinal plants have been largely neglected in this context, although their pharmacological activities have been well investigated in the past, and they may have considerable potentials for repositioning. A grand number of plant alkaloids inhibit syngeneic or xenograft tumor growth in vivo. Molecular modes of action in cancer cells include induction of cell cycle arrest, intrinsic and extrinsic apoptosis, autophagy, inhibition of angiogenesis and glycolysis, stress and anti-inflammatory responses, regulation of immune functions, cellular differentiation, and inhibition of invasion and metastasis. Numerous underlying signaling processes are affected by plant alkaloids. Furthermore, plant alkaloids suppress carcinogenesis, indicating chemopreventive properties. Some plant alkaloids reveal toxicities such as hepato-, nephro- or genotoxicity, which disqualifies them for repositioning purposes. Others even protect from hepatotoxicity or cardiotoxicity of xenobiotics and established anticancer drugs. The present survey of the published literature clearly demonstrates that plant alkaloids have the potential for repositioning in cancer therapy. Exploitation of the chemical diversity of natural alkaloids may enrich the candidate pool of compounds for cancer chemotherapy and -prevention. Their further preclinical and clinical development should follow the same stringent rules as for any other synthetic drug as well. Prospective randomized, placebo-controlled clinical phase I and II trials should be initiated to unravel the full potential of plant alkaloids for drug repositioning.

Sinomenine exerts antitumour effect in gastric cancer cells via enhancement of miR-204 expression

Gastric carcinoma (GC) is a pernicious neoplasm with high morbidity and mortality. Sinomenine (SIN) has long been exploited to heal rheumatoid arthritis. Recently, SIN has been discovered to exert the antitumour functions in diverse cancers. However, the impacts of SIN on GC remain indistinct. We attempted to expose the antitumour effect of SIN on GC. MKN45 and SGC-7901 cells were administered with SIN for 24 hours, cell viability, proliferation, apoptosis, migration, invasion and the associated proteins in the above processes were examined via exploiting CCK-8, BrdU, flow cytometry, Transwell and Western blot. MiR-204 expression in GC tumour tissues, different GC cell lines and SIN-stimulated GC cells was investigated by executing RT-qPCR. The above cell biological processes were reassessed after transfection with miR-204 inhibitor. The latent mechanisms were probed by examining AMPK and Wnt/β-catenin pathways. We found that SIN memorably repressed cell proliferation, evoked apoptosis and affected CyclinD1, Bcl-2, Bax and cleaved-caspase-3 expression in MKN45 and SGC-7901 cells. Cell migration, invasion and expression of MMP-9 and Vimentin were all restrained by SIN stimulation. The increase of miR-204 was discovered in GC tissues and SIN-treated MKN45 and SGC-7901 cells. But suppression of miR-204 was observed in AGS, MKN28, MKN45 and SGC-7901 cells. Suppression of miR-204 overturned the inhibitory functions of SIN in MKN45 and SGC-7901 cells. Besides, SIN prohibited AMPK and Wnt/β-catenin pathways via enhancement of miR-204. In conclusion, these findings suggested that SIN exerted the antitumour activity in GC cells by hindering AMPK and Wnt/β-catenin pathways via enhancement of miR-204.

Anticancer Effects of Constituents of Herbs Targeting Osteosarcoma

Osteosarcoma is a rare primary malignancy of bone that is prone to early metastasis. Resection surgery and chemotherapeutic regimens are current standard treatments for osteosarcoma. However, the long-term survival rate of patients with osteosarcoma is low due to a high risk of metastasis. Hence, a new approach is urgently needed to improve the treatment of osteosarcoma. Compared with chemotherapy, natural active constituents isolated from herbs exhibit less adverse effects and better anti-tumor effects. This study aimed to summarize the anticancer effects of constituents of herbs on the progression and metastasis of osteosarcoma cells. It showed that many constituents of herbs inhibited osteosarcoma by targeting proliferation, matrix metalloproteinases, integrin and cadherin, and angiogenesis. The findings might be beneficial for the development of new drugs and treatment strategies.

Magnolol induces apoptosis in osteosarcoma cells via G0/G1 phase arrest and p53-mediated mitochondrial pathway

Osteosarcoma is a highly invasive primary malignancy of bone. Magnolol is biologically active, which shows antitumor effects in a variety of cancer cell lines. However, it has not been elucidated magnolol's effects on human osteosarcoma cells (HOC). This study aimed to determine antitumor activity of magnolol and illustrate the molecular mechanism in HOC. Magnolol showed significant inhibition effect of growth on MG-63 and 143B cells and induced apoptosis and cell cycle arrest at G0/G1. In osteosarcoma cells, magnolol upregulated expressions of proapoptosis proteins and suppressed expressions of antiapoptosis proteins. Additionally, under the pretreatment of pifithrin-a (PFT-a, a p53 inhibitor), the magnolol-induced apoptosis was significantly reversed. The results above indicated that magnolol induces apoptosis in osteosarcoma cells may via G0/G1 phase arrest and p53-mediated mitochondrial pathway.

Role of Autophagy in Renal Cancer

Autophagy is a highly conserved catabolic process with critical functions in maintenance of cellular homeostasis under normal growth conditions and in preservation of cell viability under stress. The role of autophagy in cancer is dual-sided. Autophagy-deficient cells are often more tumorigenic than their wild type counterparts in association with DNA damage accumulation, oxidative stress. At the same time, autophagy is a major cell survival mechanism. In recent years, it has been well demonstrated that autophagy may have relation with renal cell carcinoma (RCC). This review focuses on the research progress in relation between autophagy and RCC and the pharmacologic manipulation of autophagy for RCC treatment.

Antiangiogenic Effect of Alkaloids

Alkaloids are among the natural phytochemicals contained in functional foods and nutraceuticals and have been suggested for the prevention and/or management of oxidative stress and inflammation-mediated diseases. In this review, we aimed to describe the effects of alkaloids in angiogenesis, the process playing a crucial role in tumor growth and invasion, whereby new vessels form. Antiangiogenic compounds including herbal ingredients, nonherbal alkaloids, and microRNAs can be used for the control and treatment of cancers. Several lines of evidence indicate that alkaloid-rich plants have several interesting features that effectively inhibit angiogenesis. In this review, we present valuable data on commonly used alkaloid substances as potential angiogenic inhibitors. Different herbal and nonherbal ingredients, introduced as antiangiogenesis agents, and their role in angiogenesis-dependent diseases are reviewed. Studies indicate that angiogenesis suppression is exerted through several mechanisms; however, further investigations are required to elucidate their precise molecular and cellular mechanisms, as well as potential side effects.

Sinomenine Induces G1-Phase Cell Cycle Arrest and Apoptosis in Malignant Glioma Cells Via Downregulation of Sirtuin 1 and Induction of p53 Acetylation

Sinomenine, a bioactive alkaloid isolated from the traditional Chinese herb Sinomenium acutum, possesses antiinflammatory, antinociceptive, antifibrotic, and antitumorigenic properties. In this work, we sought to explore the biological effects of sinomenine on glioma cells. It was found that sinomenine caused a concentration-dependent inhibition of viability in both U87 and U251 glioma cells. Sinomenine at 16 μmol/L caused 55% to 60% reduction in the proliferation of U87 and U251 cells. Moreover, sinomenine treatment induced a G0/G1 cell cycle arrest and apoptosis. Mechanistically, sinomenine promoted p53 expression and acetylation and reduced the expression of sirtuin 1. Ectopic expression of sirtuin 1 significantly prevented sinomenine-induced p53 acetylation and growth suppression in glioma cells. Moreover, sinomenine inhibited the growth of U87 xenograft tumors in vivo and raised the p53 protein expression. Collectively, sinomenine shows antiproliferative effects against glioma cells which is mediated through downregulation of sirtuin 1 and induction of p53 activity.

Phytochemicals Targeting VEGF and VEGF-Related Multifactors as Anticancer Therapy

The role of vascular endothelial growth factor (VEGF) in cancer cells is not limited to angiogenesis; there are also multiple factors, such as neuropilins (non-tyrosine kinases receptors), tyrosine kinases receptors, immunodeficiencies, and integrins, that interact with VEGF signaling and cause cancer initiation. By combating these factors, tumor progression can be inhibited or limited. Natural products are sources of several bioactive phytochemicals that can interact with VEGF-promoting factors and inhibit them through various signaling pathways, thereby inhibiting cancer growth. This review provides a deeper understanding of the relation and interaction of VEGF with cancer-promoting factors and phytochemicals in order to develop multi-targeted cancer prevention and treatment.

Sinomenine hydrochloride inhibits cell survival in human hepatoma Huh7 cells

The present study aimed to investigate the effect of sinomenine hydrochloride (SIN) on cell survival/proliferation in the human hepatoma cell line Huh7, as well as determine the underlying mechanisms. Three different doses of SIN, 140, 280 and 560 µM, were tested. Cellular apoptosis and cell cycle distribution were analyzed by flow cytometry. Western blotting was used to determine protein levels of the apoptosis-associated regulators, cleaved caspase 3, B-cell lymphoma-2 (Bcl-2)-associated X protein (Bax), Bcl-2 homologous antagonist/killer (Bak) and Bcl-extra large (Bcl-xl), as well as the cell cycle-related regulators, p21 and p27. It was observed that the three doses of SIN were able to suppress Huh7 cell survival/proliferation, and efficiently induce cellular apoptosis as well as multiphase cell cycle arrest. Mechanistically, SIN treatment upregulated the levels of the pro-apoptotic regulators, cleaved caspase 3 and Bax, and downregulated the level of anti-apoptotic Bcl-xl. Additionally, SIN treatment also increased the protein levels of p21 and p27, as two regulators functioning to slow cell cycle progression. Taken together, the present studied indicated SIN to be a promising compound for the treatment of hepatocellular carcinoma, based on its apparent effect in modulating cell apoptosis and the cell cycle in Huh7 cells in vitro.

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.

Sinomenine Hydrochloride Inhibits the Metastasis of Human Glioblastoma Cells by Suppressing the Expression of Matrix Metalloproteinase-2/-9 and Reversing the Endogenous and Exogenous Epithelial-Mesenchymal Transition

As shown in our previous study, sinomenine hydrochloride (SH), the major bioactive alkaloid isolated from Sinomenium acutum Rehd. et Wils. (Fam. Menispermaceae), initiates the autophagy-mediated death of human glioblastoma cells by generating reactive oxygen species and activating the autophagy-lysosome pathway. However, its effects on the migration and invasion of human glioblastoma cells have not yet been elucidated. Therefore, human glioblastoma U87 and SF767 cells were treated with SH (0.125 and 0.25 mM) for 24 h, and cell migration and invasion were assessed using scratch wound healing, migration and invasion assays. SH promoted G0/G1 phase arrest, inhibited the migration and invasion of the two cell lines, suppressed the activation of nuclear factor kappa B (NFκB) and the expression of matrix metalloproteinase (MMP)-2/-9, triggered endoplasmic reticulum (ER) stress, reversed the exogenous epithelial-mesenchymal transition (EMT) induced by the inflammatory microenvironment and the endogenous EMT. Additionally, NFκB p65 overexpression blocked the SH-mediated inhibitory effects on MMP-2/-9 expression and cell invasion. SH-induced autophagy was reduced in CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP) or autophagy-related 5 (ATG5)-silenced human glioblastoma cells and cells treated with 4-phenylbutyric acid (4-PBA) or 3-methyladenine (3-MA), as shown by the decreased levels of the microtubule-associated protein light chain 3B (LC3B)-II and autophagic vacuoles (AVs) stained with monodansylcadaverine (MDC), respectively. Moreover, knockdown of CHOP or ATG5 and treatment with 4-PBA or 3-MA abolished the SH-mediated inhibition of mesenchymal markers (vimentin, Snail and Slug) expression and cell invasion, respectively. Importantly, SH also regulated the above related pathways in nude mice. Based on these findings, SH inhibited cell proliferation by inducing cell cycle arrest, and attenuated the metastasis of U87 and SF767 cells by suppressing MMP-2/-9 expression and reversing the endogenous and exogenous EMT in vitro and/or in vivo. Thus, SH might be a new potential anti-metastasis agent for the treatment of human glioblastoma.

Effect of sinomenine hydrochloride on radiosensitivity of esophageal squamous cell carcinoma cells

Radiation therapy is one of the most important treatments for unresectable and locally advanced esophageal squamous cell carcinoma (ESCC), however, the response to radiotherapy is sometimes limited by the development of radioresistance. Sinomenine hydrochloride (SH) has anticancer activity, but its effect on the radiosensitivity of ESCC is unclear. We determined the effect of SH on the radiosensitivity of ESCC cells and elucidated its potential radiosensitization mechanisms in vitro and in vivo. ESCC cells were subjected to SH and radiation, both separately and in combination. Untreated cells served as controls. The CCK-8 assay was used to evaluate cell proliferation, and the clonogenic assay to estimate radiosensitization. Flow cytometry was used to investigate cell cycle phases and cell apoptosis. Bcl-2, Bax, cyclin B1, CDK1, Ku86, Ku70, and Rad51 expression was evaluated using western blotting. In vivo, tumor xenografts were created using BALB/c nude mice. Tumor-growth inhibition was recorded, and Ki-67 and Bax expression in the tumor tissues was assessed using immunohistochemistry. SH inhibited ESCC cell growth and markedly increased their radiosensitivity by inducing G2/M phase arrest. SH combined with radiation therapy significantly increased ESCC cell apoptosis. The molecular mechanism by which SH enhanced radiosensitivity of ESCC cells was related to Bcl-2, cyclin B1, CDK1, Ku86, Ku70, and Rad51 downregulation and Bax protein expression upregulation. SH combined with radiation considerably delayed the growth of tumor xenografts in vivo. Immunohistochemical analysis showed that in the SH combined with radiation group, the expression of Bax was significantly higher while that of Ki-67 was lower than the expressions in the control groups. Taken together, our findings showed that SH could improve the sensitivity of radiation in ESCC cells by inducing G2/M phase arrest, promoting radiation-induced apoptosis and inhibiting DSB-repair pathways. SH appears to be a prospective radiosensitizer for improving the efficacy of radiotherapy for ESCC.

Sinomenine hydrochloride attenuates the proliferation, migration, invasiveness, angiogenesis and epithelial-mesenchymal transition of clear-cell renal cell carcinoma cells via targeting Smad in vitro

New strategies for the treatment of clear-cell renal cell carcinoma (ccRCC) are urgently needed. Recently, accumulating evidence has demonstrated that sinomenine hydrochloride (SH), extracted from the plant sinomenium acutum, has potent anti-cancer activity in multiple human malignant solid tumors. However, the underlying molecular mechanism by which SH treatment exerts its antagonizing tumorigenic effects has not been clearly elucidated. In this study, we showed that SH treatment exerted profound effects on cell growth in ccRCC in a dose- and time-dependent manner in vitro. Furthermore, treatment with SH significantly suppressed the migration, invasiveness and angiogenesis of ccRCC cells in vitro. Mechanistically, we revealed that SH treatment blocked epithelial-mesenchymal transition (EMT) through the downregulation of the expression of the transcription factors Snail1 and Twist in ccRCC cells. Additionally, the depletion of p-Smad2 and p-Smad3 was required for SH treatment to inhibit EMT effectively. Taken together, these findings indicate an anti-cancer role for SH in ccRCC cells and reveal a potential molecular mechanism by which Smad / EMT axis functions in ccRCC, as its hyperactivation has been associated with cell proliferation, migration, invasiveness and angiogenesis in this cancer type. These observations suggest that SH can act as an efficacious adjuvant chemotherapeutic candidate that targets the Smad/EMT axis in patients with ccRCC.

Baicalein inhibits progression of osteosarcoma cells through inactivation of the Wnt/β-catenin signaling pathway

Osteosarcoma is a very common type of malignant bone tumor in children and young adults and aberrant activation of Wnt/β-catenin signaling pathway has been discovered in osteosarcoma. The traditional Chinese medicine baicalein was proved to have anti-proliferative and anti-metastatic properties in osteosarcoma, but the mechanism remained poorly understood. In the present study, we assessed the effects of baicalein on osteosarcoma and detected the potential molecular mechanism. We found that baicalein significantly suppressed the proliferation of osteosarcoma cells in a concentration- and time-dependent manner. In additional, baicalein could induce apoptosis and cell cycle arrest and reduce cell motility. Moreover, the level of β-catenin and its target genes, including c-myc, cyclinD1, and survivin significantly decreased in baicalein-treated osteosarcoma cells, whereas exogenous expression of β-catenin could reverse the anti-proliferative and anti-metastatic effects of baicalein. Subsequently, we established a 143B xenograft tumor model and found that baicalein treatment significantly inhibited tumor growth accompanied with inhibiting Wnt/β-catenin pathway. Thus, these findings suggest that baicalein may be a potentially effective Chinese herbal medicine for therapeutics of osteosarcoma and Wnt/β-catenin signaling pathway may serve as an efficient molecular marker or predictive target for osteosarcoma.

Ursolic acid inhibits proliferation and induces apoptosis by inactivating Wnt/β-catenin signaling in human osteosarcoma cells

Although multiple chemotherapeutic agents have been used for osteosarcoma (OS) treatment, their mechanisms need further study. Ursolic acid (UA), a pentacyclic triterpenoid, can reduce cell proliferation and induce apoptosis in various cancer cells, such as OS. However, the exact mechanism underlying this function remains unclear. In this study, we investigated the anti‑proliferative effect of UA in human OS 143B cells and dissected the possible molecular mechanism underlying this effect. We demonstrated that UA can reduce cell proliferation, induce apoptosis and arrest cell cycle in 143B cells, as well as inhibit OS tumor growth in a mouse xenograft model. Using a luciferase reporter assay, we found that the Wnt/β‑catenin signaling is inhibited by UA in 143B cells. Correspondingly, the expression level and nuclear translocation of β‑catenin are both decreased by UA. Exogenous expression of β‑catenin attenuates the anticancer effect of UA in 143B cells, while knockdown of β‑catenin enhances this effect. UA increases the expression level of p53 in a concentration‑dependent manner, and inhibition of p53 reduces the anticancer effect of UA in 143B cells. Moreover, inhibition of p53 partly reverses the UA‑induced downregulation of β‑catenin, as do the targets of Wnt/β‑catenin signaling, such as c‑Myc and cyclin D1. Our findings indicated that UA can inhibit the proliferation of 143B OS cells through inactivation of Wnt/β-catenin signaling, which may be mediated partly by upregulating the expression of p53.

The neuroprotection of Sinomenine against ischemic stroke in mice by suppressing NLRP3 inflammasome via AMPK signaling

Neuroinflammation remains the primary cause of morbidity and mortality in stroke-induced secondary brain injury. The NOD-like receptor pyrin 3 (NLRP3) inflammasome is involved in diverse inflammatory diseases, including cerebral ischemia, and is thus considered an effective therapeutic target. In the present study, we investigated the neuroprotection of Sinomenine (SINO), a potent natural anti-apoptotic and anti-inflammatory molecule, against cerebral ischemia in a mouse model of middle cerebral artery occlusion (MCAO) in vivo and in an oxygen glucose deprivation (OGD)-treated astrocytes/microglia model in vitro. SINO administration intraperitoneally alleviated the cerebral infarction, brain edema, neuronal apoptosis, and neurological deficiency after MCAO induction. SINO also attenuated astrocytic and microglial activation in the ischemic hemisphere. NLRP3 inflammasome activation after MCAO and OGD induction, with the up-regulation of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cleaved caspase-1 and pro-inflammatory cytokines, was significantly inhibited by SINO treatment both in vivo and in vitro. In addition, SINO reversed the OGD-induced inhibition of AMPK phosphorylation in vitro. Further, the suppressive effect of SINO on NLRP3 inflammasomes was blocked by an AMPK inhibitor, Compound C. Our findings demonstrate that SINO exerts a neuroprotective effect in ischemic stroke by inhibiting NLRP3 inflammasomes via the AMPK pathway, which also provides evidence of a novel treatment for clinical stroke therapy.