Hesperidin and its aglycone hesperetin in breast cancer therapy: A review of recent developments and future prospects

Breast cancer (BC) has high incidence and mortality rates, making it a major global health issue. BC treatment has been challenging due to the presence of drug resistance and the limited availability of therapeutic options for triple-negative and metastatic BC, thereby urging the exploration of more effective anti-cancer agents. Hesperidin and its aglycone hesperetin, two flavonoids from citrus species, have been extensively evaluated for their anti-cancer potentials. In this review, available literatures on the chemotherapeutic and chemosensitising activities of hesperidin and hesperetin in preclinical BC models are reported. The safety and bioavailability of hesperidin and hesperetin as well as the strategies to enhance their bioavailability are also discussed. Overall, hesperidin and hesperetin can inhibit cell proliferation, migration and BC stem cells as well as induce apoptosis and cell cycle arrest in vitro. They can also inhibit tumour growth, metastasis and neoplastic changes in tissue architecture in vivo. Moreover, the co-administration of hesperidin or hesperetin with doxorubicin, letrozole or tamoxifen can enhance the efficacies of these clinically available agents. These chemotherapeutic and chemosensitising activities of hesperidin and hesperetin have been linked to several mechanisms, including the modulation of signalling pathways, glucose uptake, enzymes, miRNA expression, oxidative status, cell cycle regulatory proteins, tumour suppressor p53, plasma and liver lipid profiles as well as DNA repair mechanisms. However, poor water solubility, extensive phase II metabolism and apical efflux have posed limitations to the bioavailability of hesperidin and hesperetin. Various strategies for bioavailability enhancement have been studied, including the utilisation of nano-based drug delivery systems and the co-administration of hesperetin with other flavonoids. In particular, nanoformulated hesperidin and hesperetin possess greater chemotherapeutic and chemosensitising activities than free compounds. Despite promising preclinical results, further safety and efficacy evaluation of hesperidin and hesperetin as well as their nanoformulations in clinical trials is required to ascertain their potentials to be developed as clinically useful agents for BC treatment.     

SPOCK1 promotes the invasion and metastasis of gastric cancer through Slug‐induced epithelial‐mesenchymal transition

Metastasis is a crucial impediment to the successful treatment for gastric cancer. SPOCK1 has been demonstrated to facilitate cancer metastasis in certain types of cancers; however, the role of SPOCK1 in the invasion and metastasis of gastric cancer remains elusive. SPOCK1 and epithelial‐mesenchymal transition (EMT)‐related biomarkers were detected by immunohistochemistry and Western blot in gastric cancer specimens. Other methods including stably transfected against SPOCK1 into gastric cancer cells, Western blot, migration and invasion assays in vitro and metastasis assay in vivo were also performed. The elevated expression of SPOCK1 correlates with EMT‐related markers in human gastric cancer tissue, clinical metastasis and a poor prognosis in patients with gastric cancer. In addition, knockdown of SPOCK1 expression significantly inhibits the invasion and metastasis of gastric cancer cells in vitro and in vivo, inversely, SPOCK1 overexpression results in the opposite effect. Interestingly, SPOCK1 expression has no effect on cell proliferation in vitro and in vivo. Regarding the mechanism(s) of SPOCK1‐induced cells invasion and metastasis, we prove that Slug‐induced EMT is involved in SPOCK1‐facilitating gastric cancer cells invasion and metastasis. The elevated SPOCK1 expression is closely correlated with cancer metastasis and patient survival, and SPOCK1 promotes the invasion and metastasis of gastric cancer through Slug‐mediated EMT, thereby possibly providing a novel therapeutic target for gastric cancer.     

Marine algal fucoxanthin inhibits the metastatic potential of cancer cells

Metastasis is major cause of malignant cancer-associated mortality. Fucoxanthin has effect on various pharmacological activities including anti-cancer activity. However, the inhibitory effect of fucoxanthin on cancer metastasis remains unclear. Here, we show that fucoxanthin isolated from brown alga Saccharina japonica has anti-metastatic activity. To check anti-metastatic properties of fucoxanthin, in vitro models including assays for invasion, migration, actin fiber organization and cancer cell–endothelial cell interaction were used. Fucoxanthin inhibited the expression and secretion of MMP-9 which plays a critical role in tumor invasion and migration, and also suppressed invasion of highly metastatic B16-F10 melanoma cells as evidenced by transwell invasion assay. In addition, fucoxanthin diminished the expressions of the cell surface glycoprotein CD44 and CXC chemokine receptor-4 (CXCR4) which play roles in migration, invasion and cancer–endothelial cell adhesion. Fucoxanthin markedly suppressed cell migration in wound healing assay and inhibited actin fiber formation. The adhesion of B16-F10 melanoma cells to the endothelial cells was significantly inhibited by fucoxanthin. Moreover, in experimental lung metastasis in vivo assay, fucoxanthin resulted in significant reduction of tumor nodules. Taken together, we demonstrate, for the first time, that fucoxanthin suppresses metastasis of highly metastatic B16-F10 melanoma cells in vitro and in vivo.     

Therapeutic effects and potential mechanism of dehydroevodiamine on N-methyl-N′-nitro-N-nitrosoguanidine-induced chronic atrophic gastritis

BackgroundsDehydroevodiamine (DHE) is a quinazoline alkaloid isolated from a Chinese herbal medicine, named Euodiae Fructus (Wu-Zhu-Yu in Chinese). This study aimed to investigate the therapeutic effects and potential mechanism of DHE on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced chronic atrophic gastritis (CAG) based on integrated approaches.MethodsTherapeutic effects of DHE on serum biochemical indices and histopathology of gastric tissue in MNNG-induced CAG rats were analyzed. MNNG-induced GES-1 human gastric epithelial cell injury model was established. Cell viability and proliferation was quantified by a cell counting kit-8 assay. Cell morphology and mitochondrial membrane potential (MMP) were detected by a high content screening (HCS) assay. Cell migration and invasion were detected by a Transwell chamber. Moreover, UHPLC-Q-TOF/MS was performed to investigate the potential metabolites and signaling pathway affecting the protective effects of DHE on MNNG-induced cell migration and invasion of GES-1. Furthermore, in view of the key role of angiogenesis in the transformation of inflammation and cancer, this study explored relative mRNA and protein expression levels of HIF-1α-mediated VEGF pathway in vivo and in vitro by RT-PCR and Western Blotting, respectively.ResultsThe results showed that the therapeutic effects of DHE on CAG rats were presented in down-regulation serum biochemical indices and alleviating histological damage of gastric tissue. Besides, DHE has an effect on increasing cell proliferation of GES-1 cells, ameliorating MNNG-induced gastric epithelial cell damage and mitochondrial dysfunction. In addition, DHE could inhibit MNNG induced migration and invasion of GES-1 cells. Cell metabolomics analyses showed that the protective effect of DHE on GES-1 cells is mainly associated with the regulation of inflammation metabolites and energy metabolism related pathways. It was found that DHE has a regulating effect on tumor angiogenesis and can inhibit the relative gene and protein expression of HIF-1α-mediated VEGF signaling pathway.ConclusionsThe present work highlighted the role of DHE ameliorated gastric injury in MNNG-induced CAG rats in vivo and GES-1 cell migration in vitro by inhibiting HIF-1α/VEGF angiogenesis pathway. These results suggest that DHE may be the effective components of Euodiae Fructus, which provides a new agent for the treatment of CAG.     

Glyoxalase-I is a novel prognosis factor associated with gastric cancer progression

Glyoxalase I (GLO1), a methylglyoxal detoxification enzyme, is implicated in the progression of human malignancies. The role of GLO1 in gastric cancer development or progression is currently unclear. The expression of GLO1 was determined in primary gastric cancer specimens using quantitative polymerase chain reaction, immunohistochemistry (IHC), and western blotting analyses. GLO1 expression was higher in gastric cancer tissues, compared with that in adjacent noncancerous tissues. Elevated expression of GLO1 was significantly associated with gastric wall invasion, lymph node metastasis, and pathological stage, suggesting a novel role of GLO1 in gastric cancer development and progression. The 5-year survival rate of the lower GLO1 expression groups was significantly greater than that of the higher expression groups (log rank P = 0.0373) in IHC experiments. Over-expression of GLO1 in gastric cancer cell lines increases cell proliferation, migration and invasiveness. Conversely, down-regulation of GLO1 with shRNA led to a marked reduction in the migration and invasion abilities. Our data strongly suggest that high expression of GLO1 in gastric cancer enhances the metastasis ability of tumor cells in vitro and in vivo, and support its efficacy as a potential marker for the detection and prognosis of gastric cancer.     

Dulcitol suppresses proliferation and migration of hepatocellular carcinoma via regulating SIRT1/p53 pathway

BackgroundHepatocellular carcinoma (HCC) spreads further with continuance and increasing incidence due to its high-grade malignancy and metastasis. More effectual strategies on blocking proliferation and metastasis of cancer cells should be studied in HCC. Dulcitol, a natural product extracted from euonymus alatus, was reported that it could induce apoptosis of C6 glioma cells. However, the underlying mechanism of Dulcitol on HCC remains unclea.PurposeIn this study, we aimed to reveal the effect and potential mechanisms of Dulcitol on hepatocellular carcinoma in vitro and in vivo.Study design and methods The cell proliferation and apoptosis were evaluated by MTT, Ki-67 and Hoechst 33258/PI double staining. The migratory and invasive abilities of HepG2 cells were measured by wound-healing and transwell assays. Pathological changes of tumor tissue were observed by HE staining and IHC methods. The expression levels of protein were detected using Western Blot analysis.ResultsThe results showed that Dulcitol inhibited HepG2 cells proliferation by down-regulating the protein expression of SIRT1, Bcl-2, along with up-regulating p53, acetylated-p53 (K382), cleaved-caspase9, cleaved-caspase3, Bax, and cytochrome c in a dose-dependent manner. Furthermore, Dulcitol surpressed the migration and invasion of HepG2 cells through decreasing the levels of MMP-2, uPA and MMP-9 and increasing E-cadherin associated with tumor invasion. In vivo, Dulcitol distinctly inhibited the growth of HepG2 cancer xenograft tumors via inhibiting SIRT1/p53 pathway.ConclusionsOur findings suggested that Dulcitol acted as a SIRT1 inhibitor, inducing apoptosis and inhibiting proliferation, migration and invasion of HepG2 cells and its modulatory mechanism seemed to be associated with regulation of MMPs, SIRT1/p53 pathways.     

Laminin 511-E8 Fragment Offers Superior Adhesion Properties for Gastric Cancer Cells Compared with Full-Length Laminin 511

Simple SummaryNumerous studies over the past few decades have revealed that the interactions of gastric cancer cells with laminins through integrins play important roles in tumor cell proliferation, infiltration, and metastasis. However, the association between gastric cancer cells and the laminin E8 fragment, which is the smallest integrin-binding component, has not been investigated. In this study, we revealed that the laminin 511-E8 fragment had a greater impact on the adhesion, morphology, and proliferation of gastric cancer cells than full-length laminin 511. Thus, the laminin 511-E8 fragment is considered to be suitable for investigating the interaction between gastric cancer cells and extracellular matrices in tumor invasion and metastasis. Further, the involvement of Cdc42 in the laminin 511-E8 fragment-induced enhanced adhesion of gastric cancer cells was suggested.AbstractBackground: The interaction between cancer cells and laminin (Ln) is a key event in tumor invasion and metastasis. Previously, we determined the effect of full-length Ln511 on gastric cancer cells. However, the interactions between the Ln511-E8 fragment, a truncated protein of Ln511, and gastric cancer cells have not been investigated. Methods: We investigated the adhesion properties of gastric cancer cells to full-length Ln511 and Ln511-E8 fragments. Results: The proliferation of four gastric cancer cell lines (SH-10-TC, MKN74, SC-6-JCK, and MKN45) was highest on the Ln511-E8 fragment. Further, a larger cytoplasm was observed in SH-10-TC and MKN74 cells cultured on full-length Ln511 or Ln511-E8 fragments. The percentage of adhesive cells was highest on the Ln511-E8 fragment in all four cell lines. Moreover, adhesion of the gastric cancer cells to Ln511-E8 fragment-coated plates was reduced by the Cdc42 GTPase inhibitor in a dose-dependent manner, suggesting the involvement of Cdc42 in the Ln511-E8 fragment-induced enhanced adhesion of gastric cancer cells. Conclusions: The Ln511-E8 fragment had a greater impact on the adhesion, morphology, and proliferation of gastric cancer cells than full-length laminin. Thus, the Ln511-E8 fragment is suitable for investigating the interaction between gastric cancer cells and extracellular matrices in tumor invasion and metastasis.     

Harmine induces apoptosis and inhibits tumor cell proliferation,migration and invasion through down-regulation of cyclooxygenase-2 expression in gastric cancer

Cyclooxygenase-2 (COX-2) plays an important role in the carcinogenesis and progression of gastric cancer. Harmine is reported as a promising drug candidate for cancer therapy; however, effects and action mechanism of harmine on the human gastric cancer cells remain unclear. This study evaluated the anti-tumor effects of harmine on human gastric cancer both in vitro and in vivo. The cell proliferation was determined using MTT colorimetric assay. Apoptosis was measured by DAPI staining and flow cytometry analysis. The wound healing and transwell invasion assays were performed to evaluate the effects of harmine on the migration and invasion of gastric cancer cells. The expression of COX-2, proliferating cell nuclear antigen (PCNA), Bcl-2, Bax and matrix metalloproteinase-2 (MMP-2) was detected by Western blot analysis. Our results showed that harmine significantly inhibited cellular proliferation, migration, invasion and induced apoptosis in vitro, as well as inhibited tumor growth in vivo. In addition, harmine significantly inhibited the expression of COX-2, PCNA, Bcl-2 and MMP-2 as well as increased Bax expression in gastric cancer cells. These results collectively indicate that harmine induces apoptosis and inhibits proliferation, migration and invasion of human gastric cancer cells, which may be mediated by down-regulation of COX-2 expression.     

Epigenetic Silencing of miR-338-3p Contributes to Tumorigenicity in Gastric Cancer by Targeting SSX2IP

MicroRNA has been recently recognized as playing a prominent role in tumorigenesis and metastasis. Here, we report that miR-338-3p was epigenetically silenced in gastric cancer, and its down-regulation was significantly correlated with gastric cancer clinicopathological features. Strikingly, restoring miR-338-3p expression in SGC-7901 gastric cancer cells inhibited proliferation, migration, invasion and tumorigenicity in vitro and in vivo, at least partly through inducing apoptosis. Furthermore, we demonstrate the oncogene SSX2IP is a target of miR-338-3p. We propose that miR-338-3p functions as a tumor suppressor in gastric cancer, and the methylation status of its CpG island could serve as a potential diagnostic marker for gastric cancer.     

NME2 Reduces Proliferation,Migration and Invasion of Gastric Cancer Cells to Limit Metastasis

Gastric cancer is one of the most common malignancies and has a high rate of metastasis. We hypothesize that NME2 (Nucleoside Diphosphate Kinase 2), which has previously been considered as an anti-metastatic gene, plays a role in the invasiveness of gastric cancer cells. Using a tissue chip technology and immunohistochemistry, we demonstrated that NME2 expression was associated with levels of differentiation of gastric cancer cells and their metastasis into the lymph nodes. When the NME2 gene product was over-expressed by ;in vitro stable transfection, cells from BGC823 and MKN45 gastric cancer cell lines had reduced rates of proliferation, migration, and invasion through the collagen matrix, suggesting an inhibitory activity of NME2 in the propagation and invasion of gastric cancer. NME2 could, therefore, severe as a risk marker for gastric cancer invasiveness and a potential new target for gene therapy to enhance or induce NME2 expression.     

IFN-γ Induces Gastric Cancer Cell Proliferation and Metastasis Through Upregulation of Integrin β3-Mediated NF-κB Signaling

Interferon γ (IFN-γ), a multifunctional cytokine, was upregulated in the resected gastric cancer tissue. However, whether IFN-γ is involved in the regulation of gastric cancer has not been well elucidated. Herein, we aimed to investigate the effects and mechanism of IFN-γ on gastric cancer. In this study, we found a vital role of IFN-γ in enhancing proliferation, inhibiting apoptosis, and promoting cell migration and invasion in gastric cancer cells SGC-7901 and MGC-803. Additionally, IFN-γ activated nuclear factor κB (NF-κB) signaling pathway by upregulating the phosphorylation expression of p65 and IκBα, and induced the expression of integrin β3 in vitro. Therefore, to further investigate the relationship between IFN-γ and integrin β3, SGC-7901 cells were transfected with integrin β3 siRNA. And then cells expressed lower cell viability, migration, and invasion rates, while cell apoptosis was significantly enhanced. Meanwhile, expression of integrin β3, MMP-2, MMP-9, and NF-κB, including p65 and IκBα, and the nuclear translocation of NF-κB/p65 were dramatically repressed, whereas IFN-γ significantly improved the effects. Moreover, in vivo, the experiment of xenograft model and pulmonary metastasis model also retarded in integrin β3 siRNA group. And the expression of integrin β3, MMP-2, MMP-9, and NF-κB was repressed. However, the treatment with IFN-γ improved tumor volume, lung/total weight, tumor nodules, and the protein expression described above compared with integrin β3 siRNA group. Overall, the results indicated that IFN-γ induces gastric cancer cell proliferation and metastasis partially through the upregulation of integrin β3-mediated NF-κB signaling. Hence, the inhibition of IFN-γ or integrin β3 may be the key for the treatment of gastric cancer.     

Curcumin inhibits lung cancer cell migration and invasion through Rac1-dependent signaling pathway

Curcumin, a natural and crystalline compound isolated from the plant Curcuma longa with low toxicity in normal cells, has been shown to protect against carcinogenesis and prevent tumor development. However, little is known about antimetastasis effects and mechanism of curcumin in lung cancer. Rac1 is an important small Rho GTPases family protein and has been widely implicated in cytoskeleton rearrangements and cancer cell migration, invasion and metastasis. In this study, we examined the influence of curcumin on in vitro invasiveness of human lung cancer cells and the expressions of Rac1. The results indicate that curcumin at 10 μM slightly reduced the proliferation of 801D lung cancer cells but showed an obvious inhibitory effect on epidermal growth factor or transforming growth factor β1-induced lung cancer cell migration and invasion. Meanwhile, we demonstrated that the suppression of invasiveness correlated with inhibition of Rac1/PAK1 signaling pathways and matrix metalloproteinase (MMP) 2 and 9 protein expression by combining curcumin treatment with the methods of Rac1 gene silence and overexpression in lung cancer cells. Laser confocal microscope also showed that Rac1-regulated actin cytoskeleton rearrangement may be involved in anti-invasion effect of curcumin on lung cancer cell. At last, through xenograft experiments, we confirmed the connection between Rac1 and the growth and metastasis inhibitory effect of curcumin in vivo. In summary, these data demonstrated that low-toxic levels of curcumin could efficiently inhibit migration and invasion of lung cancer cells through inhibition of Rac1/PAK1 signaling pathway and MMP-2 and MMP-9 expression, which provided a novel insight into the molecular mechanism of curcumin against lung cancer.     

Upregulation of the Non-Coding RNA OTUB1-isoform 2 Contributes to Gastric Cancer Cell Proliferation and Invasion and Predicts Poor Gastric Cancer Prognosis

Background: The deubiquitinase OTUB1 plays critical oncogenic roles and facilitates tumor progression in cancer. However, less is known regarding the aberrant expression, clinical significance and biological functions of the non-coding RNA OTUB1-isoform 2. We aimed to evaluate the OTUB1-isoform 2 levels in gastric cancer and their possible correlation with clinicopathologic features and patient survival to reveal its biological effects in gastric cancer progression.Methods: Total RNA extraction was performed on 156 gastric cancer case samples, and RT-qPCR was conducted. Chi-square test analysis was used to calculate the correlation between pathological parameters and the OTUB1-isoform 2 mRNA levels. Kaplan-Meier and Cox proportional hazards analyses were used to analyze the overall survival (OS) and disease-free survival (DFS) rates. Nuclear and cytoplasmic RNAs were isolated to detect the subcellular localization of OTUB1-isoform 2. We also assessed whether overexpression of OTUB1-isoform 2 influenced in vitro cell proliferation, cell cycle progression, tumor cell invasion and migration, as well as in vivo nude mouse xenograft and metastasis models.Results: The OTUB1-isoform 2 expression levels were higher in the gastric cancer samples than in the paratumorous gland samples. OTUB1-isoform 2 expression levels tightly correlated with tumor size, lymph node metastasis and TNM staging. Higher OTUB1-isoform 2 expression levels led to significantly poorer OS and DFS rates, and a multivariate analysis revealed that OTUB1-isoform 2 was an independent risk factor for DFS. OTUB1-isoform 2 was predominantly localized in the cell nucleus. Ectopic overexpression of OTUB1-isoform 2 in gastric cancer cells stimulated proliferation by inducing G₁-S transition, suppression of cell apoptosis and promotion of tumor cell invasion and migration. Finally, OTUB1-isoform 2 overexpression promoted tumor growth and tumor metastasis in nude mice models.Conclusions: Our study suggests that OTUB1-isoform 2 independently predicts poor prognosis and promotes tumor progression in gastric cancer. The non-coding RNA OTUB1-isoform 2 should be targeted in future molecular therapies.     

MicroRNA-137 Contributes to Dampened Tumorigenesis in Human Gastric Cancer by Targeting AKT2

MiRNAs play important roles in tumorigenesis. This study focused on exploring the effects and regulation mechanism of miRNA-137 on the biological behaviors of gastric cancer. Total RNA was extracted from tissues of 100 patients with gastric cancer and from four gastric cancer cell lines. Expression of miR-137 was detected by real-time PCR from 100 patients. The effects of miR-137 overexpression on gastric cancer cells’ proliferation, apoptosis, migration and invasion ability were investigated in vitro and in vivo. The target gene of miR-137 was predicted by Targetscan on line software, screened by dual luciferase reporter gene assay and demonstrated by western blot. As a result, the expression of miR-137 was significant reduced in gastric cancer cell line HGC-27, HGC-803, SGC-7901 and MKN-45 as well as in gastric cancer tissues compared with GES-1 cell or matched adjacent non-neoplastic tissues (p<0.001). The re-introduction of miR-137 into gastric cancer cells was able to inhibit cell proliferation, migration and invasion. The in vivo experiments demonstrated that the miR-137 overexpression can reduce the gastric cancer cell proliferation and metastasis. Bioinformatic and western blot analysis indicated that the miR-137 acted as tumor suppressor roles on gastric cancer cells through targeting AKT2 and further affecting the Bad and GSK-3β. In conclusion, the miR-137 which is frequently down-regulated in gastric cancer is potentially involved in gastric cancer tumorigenesis and metastasis by regulating AKT2 related signal pathways.     

Inhibition of histone acetyltransferase by naringenin and hesperetin suppresses Txnip expression and protects pancreatic β cells in diabetic mice

BackgroundThe damage of pancreatic β cells is a major pathogenesis of the development and progression of type 2 diabetes and there is still no effective therapy to protect pancreatic β cells clinically. In our previous study, we found that Quzhou Fructus Aurantii (QFA), which is rich in flavanones, had the protective effect of pancreatic β cells in diabetic mice. However, the underlying mechanism is still unclear.PurposeIn the current study, we administered naringenin and hesperetin, two major active components of QFA, to protect pancreatic β cells and to investigate the underlying molecular mechanism focusing on the epigenetic modifications.MethodsWe used diabetic db/db mouse and INS-1 pancreatic β cell line as in vivo and in vitro models to investigate the protective effect of naringenin and hesperetin on pancreatic β cells under high glucose environment and the related mechanism. The phenotypic changes were evaluatedby immunostaining and the measurement of biochemical indexes. The molecular mechanism was explored by biological techniques such as western blotting, qPCR, ChIP-seq and ChIP-qPCR, flow cytometry and lentivirus infection.ResultsWe found that naringenin and hesperetin had an inhibitory effect on histone acetylation. We showed that naringenin and hesperetin protected pancreatic β cells in vivo and in vitro, and this effect was independent of their direct antioxidant capacity. The further study found that the inhibition of thioredoxin-interacting protein (Txnip) expression regulated by histone acetylation was critical for the protective role of naringenin and hesperetin. Mechanistically, the histone acetylation inhibition by naringenin and hesperetin was achieved through regulating AMPK-mediated p300 inactivation.ConclusionThese findings highlight flavanones and the phytomedicine rich in flavanones as important dietary supplements in protecting pancreatic β cells in advanced diabetes. In addition, targeting histone acetylation by phytomedicine is a potential strategy to delay the development and progression of diabetes.     

Aspalathin-rich green Aspalathus linearis extract suppresses migration and invasion of human castration-resistant prostate cancer cells via inhibition of YAP signaling

BackgroundMore than 80% of advanced prostate cancer (PCa) cases have bone metastasis, with a 5-year survival rate of 25%. Previously, we reported that GRT, a standardized, pharmaceutical-grade aspalathin-rich extract (12.78 g aspalathin/100 g extract), prepared from green rooibos produced from the leaves and fine stems of Aspalathus linearis, inhibits the proliferation of PCa cells, meriting this investigation to determine if GRT can suppress the migration and invasion of castration-resistant prostate cancer (CRPC) cells.PurposeIn the present study, we investigated whether GRT extract can interfere with the migration and invasion of human CRPC cells.MethodsTranswell assays were used to explore the effects of GRT on the migration and invasion of CRPC cells. Micro-Western Array (MWA) and Western blot analysis were carried out to unravel the underlying molecular mechanism(s).ResultsTreatment with 25–100 μg/ml GRT suppressed the migration and invasion of LNCaP C4-2B and 22Rv1 CRPC cells. MWA and Western blot analysis indicated that GRT treatment suppressed the protein level of yes-associated protein (YAP), macrophage stimulating 1 protein (MST1), phospho-MST1/phospho-MST2 T183/T180, and paxillin, but increased the abundance of E-cadherin. Over-expression of YAP rescued the suppressive effects of GRT on migration and invasion of CRPC cells. Treatment with the major flavonoid of GRT — the C-glucosyl dihydrochalcone, aspalathin — at a concentration of 75–100 μg/ml also reduced the migration and invasion of CRPC cells, and the inhibition was partially rescued by YAP over-expression.ConclusionsGRT treatment suppresses the migration and invasion of CRPC cells via inhibition of YAP signaling and paxillin.     

Raf kinase inhibitor protein mediated signaling inhibits invasion and metastasis of hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is the most common type of liver cancer with high mortality and poor prognosis. Mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways have been implicated in promoting tumor cell proliferation and invasion of HCC cells.MethodsAs a potential inhibitor of tumor metastasis, the role of Raf kinase inhibitor protein (RKIP) in HCC development and the functional relevance with MAPK and NF-κB signaling pathways were investigated. The levels of RKIP expression were examined in human HCC tissues and correlated with tumor stages and metastatic status. Function of RKIP in cellular proliferation, migration, invasion and apoptosis was investigated in HCC cell lines by either overexpressing or knocking down RKIP expression. Mouse xenograft model was established to assess the effect of RKIP expression on tumor growth.ResultsOur results demonstrated decreased RKIP expression in HCC tissues and a strong correlation with tumor grade and distant metastasis. Manipulation of RKIP expression in HCCLM3 and HepG2 cells indicated that RKIP functioned to inhibit HCC cell motility and invasiveness, and contributed to tumor growth inhibition in vivo. Mechanistic studies showed that the function of RKIP was mediated through MAPK and NF-κB signaling pathways. However, cell type-dependent RKIP regulation on these two pathways was also suggested, indicating the complex nature of signaling network.ConclusionOur study provides a better understanding on the molecular mechanisms of HCC metastasis and sets the foundation for the development of targeted therapeutics for HCC.     

Aiduqing formula suppresses breast cancer metastasis via inhibiting CXCL1-mediated autophagy

BackgroundMetastasis is the most common lethal cause of breast cancer-related death. Recent studies have implied that autophagy is closely implicated in cancer metastasis. Therefore, it is of great significance to explore autophagy-related molecular targets involved in breast cancer metastasis and to develop therapeutic drugs.PurposeThis study was designed to investigate the anti-metastatic effects and autophagy regulatory mechanisms of Aiduqing (ADQ) formula on breast cancer.Study Design/MethodsMultiple cellular and molecular experiments were conducted to investigate the inhibitory effects of ADQ formula on autophagy and metastasis of breast cancer cells in vitro. Meanwhile, autophagic activator/inhibitor as well as CXCL1 overexpression or interference plasmids were used to investigate the underlying mechanisms of ADQ formula in modulating autophagy-mediated metastasis. Furthermore, the zebrafish xenotransplantation model and mouse xenografts were applied to validate the inhibitory effect of ADQ formula on autophagy-mediated metastasis in breast cancer in vivo.ResultsADQ formula significantly inhibited the proliferation, migration, invasion and autophagy but induced apoptosis of high-metastatic breast cancer cells in vitro. Similar results were also observed in starvation-induced breast cancer cells which exhibited elevated metastatic ability and autophagy activity. Mechanism investigations further approved that either CXCL1 overexpression or autophagic activator rapamycin can significantly abrogated the anti-metastatic effects of ADQ formula, suggesting that CXCL1-mediated autophagy may be the crucial pathway of ADQ formula in suppressing breast cancer metastasis. More importantly, ADQ formula suppressed breast cancer growth, autophagy, and metastasis in both the zebrafish xenotransplantation model and the mouse xenografts.ConclusionOur study not only revealed the novel function of CXCL1 in mediating autophagy-mediated metastasis but also suggested ADQ formula as a candidate drug for the treatment of metastatic breast cancer.