Corrigendum: Terminalia catappa leaf extracts inhibited metastasis of A2058 and A375 melanoma cells via downregulating p-Src and ß-catenin pathway in vitro.

[This corrects the article DOI: 10.3389/fphar.2022.963589.].

Terminalia catappa leaf extracts inhibited metastasis of A2058 and A375 melanoma cells via downregulating p-Src and ß-catenin pathway in vitro.

Background: Melanoma is a highly aggressive, lethal, and malignant cancer. Once diagnosed early, it can be easily removed and cured with satisfaction. Although many methods such as surgery, chemotherapy, radiotherapy, and immunotherapy have been used to treat this disease at an advanced stage, the outcomes are poor. Terminalia catappa leaves have been shown to have various biological benefits, including antitumor activity. The specific effects and molecular mechanisms of Terminalia catappa leaf in treating A2058 and A375 melanoma cells in vitro need to be clarified. Methods: The A2058 and A375 melanoma cancer cells were treated with Terminalia catappa leaf extracts, and then the effect of Terminalia catappa leaf extracts on migration and invasion was examined. The cell migration/invasion capacities of A2058 and A375 cells were investigated by a modified Boyden chamber assay. Zymography was used to clarify the activities of matrix metalloproteinases-2 and urinary type plasminogen activator. We performed a Western blot to verify the related expression of phospho-Src (Tyr416), phospho-Focal adhesion kinase (Tyr397), Vimentin, and ß-catenin. Results: Modified Boyden chamber assays demonstrated that treatment of Terminalia catappa leaf extracts significantly inhibited A2058 and A375 cell migration/invasion capacities. In the zymography results, we showed that Terminalia catappa leaf extracts negatively modulated the activities of matrix metalloproteinases-2 and urinary type plasminogen activator. Western blot indicated that Terminalia catappa leaf extracts reduced the expression of phospho-Src (Tyr416), phospho-Focal adhesion kinase (Tyr397), Vimentin, and ß-catenin. Conclusion: Terminalia catappa leaf extracts affected the antimetastasis of the A2058 and A375 melanoma cell lines by inhibiting the Focal adhesion kinase/Src interaction and Wingless-int1/ß-catenin pathways in vitro. Terminalia catappa leaf extracts may serve as an effective chemopreventive agent against metastasis of melanoma cancer.

Cinnamaldehyde decreases the invasion and u-PA expression of osteosarcoma by down-regulating the FAK signalling pathway.

Cancer metastasis is the major cause of the high mortality risk of patients with osteosarcoma. Cinnamaldehyde has been shown to exhibit multiple tumour-suppressing activities, but its role in human osteosarcoma is not yet completely defined. In this study, the antimetastatic effect of cinnamaldehyde on highly metastatic human osteosarcoma cells was observed in vitro and in vivo using Saos-2 and 143B cells. Cinnamaldehyde reduced the activity and protein level of urokinase-type plasminogen activator (u-PA) and suppressed the invasion ability of osteosarcoma cells by inhibiting the phosphorylation of focal adhesion kinase. In addition, cinnamaldehyde reduced cell movement, cell-matrix adhesion, and the expression of the mesenchymal markers of epithelial-to-mesenchymal transition, namely, fibronectin and N-cadherin. Importantly, the oral administration of cinnamaldehyde remarkably suppressed the pulmonary metastasis of osteosarcoma in mice. Results indicated that cinnamaldehyde has therapeutic potential for inhibiting osteosarcoma metastasis.

A Cohort Study: Comorbidity and Stage Affected the Prognosis of Melanoma Patients in Taiwan.

Background: Comorbidities and stages may influence the prognosis of melanoma patients in Taiwan and need to be determined. Methods: We performed a retrospective cohort study by using the national health insurance research database in Taiwan. Patients with a primary diagnosis of melanoma by the Taiwan Cancer Registry from 2009 to 2017 were recruited as the study population. The comparison group was never diagnosed with melanoma from 2000 to 2018. The Charlson comorbidity index was conducted to calculate the subjects' disease severity. The Cox proportional hazards model analysis was used to estimate the hazard ratio of death. Results: We selected 476 patients, 55.5% of whom had comorbidity. A higher prevalence of comorbidity was associated with a more advanced cancer stage. The mortality rate increased with an increasing level of comorbidity in both cohorts and was higher among melanoma patients. The interaction between melanoma and comorbidity resulted in an increased mortality rate. Conclusion: An association between poorer survival and comorbidity was verified in this study. We found that the level of comorbidity was strongly associated with mortality. A higher risk of mortality was found in patients who had localized tumors, regional metastases, or distant metastases with more comorbidity scores. Advanced stage of melanoma patients with more comorbidities was significantly associated with the higher risk of mortality rate.

Reduction of invasion and cell stemness and induction of apoptotic cell death by Cinnamomum cassia extracts on human osteosarcoma cells.

Cinnamomum cassia possesses antioxidative activity and induces the apoptotic properties of various cancer types. However, its effect on osteosarcoma invasion and cancer stemness remains ambiguous. Here, we examined the molecular evidence of the anti-invasive effects of ethanoic C. cassia extracts (CCE). Invasion and migration were obviously suppressed after the expression of urokinase-type plasminogen activator and matrix metalloprotein 2 in human osteosarcoma 143B cells were downregulated. CCE reversed epithelial-to-mesenchymal transition (EMT) induced by transforming growth factor ß1 and downregulated mesenchymal markers, such as snail-1 and RhoA. CCE suppressed self-renewal property and the expression of stemness genes (aldehyde dehydrogenase, Nanog, and CD44) in the 143B cells. CCE suppressed cell viability, reduced the colony formation of osteosarcoma cancer cells, and induced apoptotic cell death in the 143B cells, as indicated by caspase-9 activation. The xenograft tumor model of immunodeficient BALB/c nude mice showed that CCE administered in vivo through oral gavage inhibited the growth of implanted 143B cells. These findings indicated that CCE inhibited the invasion, migration, and cancer stemness of the 143B cells. CCE reduced proliferation of 143B cell possibly because of the activation of caspase-9 and the consequent apoptosis, suggesting that CCE is a potential anticancer supplement for osteosarcoma.

Gossypol Reduces Metastasis and Epithelial-Mesenchymal Transition by Targeting Protease in Human Cervical Cancer.

Metastasis is the most prevalent cause of cancer-associated deaths amongst patients with cervical cancer. Epithelial-mesenchymal transition (EMT) is essential for carcinogenesis, and it confers metastatic properties to cancer cells. Gossypol is a natural polyphenolic compound with anti-inflammation, anti-oxidant, and anticancer activities. In this study, we investigated the antimetastatic and antitumour effects of gossypol on human cervical cancer cells (HeLa and SiHa cells). Gossypol exerted a strong inhibition effect on the migration and invasion of human cervical cancer cells. It reduced the focal adhesion kinase (FAK) pathway-mediated expression of matrix metalloproteinase-2 and urokinase-type plasminogen activator, subsequently inhibiting the invasion of SiHa cells. In addition, gossypol reversed EMT induced by transforming growth factor beta 1 (TGF-[Formula: see text]1) and up-regulated epithelial markers, such as E-cadherin but significantly suppressed Ras homolog family member (Rho)A, RhoB, and p-Samd3. The tail vein injection model showed that gossypol treatment via oral gavage reduced lung metastasis. Gossypol also decreased tumour growth in vivo in the nude mouse xenograft model. All these findings suggest that gossypol suppressed the invasion and migration of human cervical cancer cells by targeting the FAK signaling pathway and reversing TGF-[Formula: see text]1-induced EMT. Hence, gossypol warrants further attention for basic mechanistic studies and drug development.

Antimetastatic effects of gossypol on colon cancer cells by targeting the u-PA and FAK pathways.

Metastasis is the most prevalent cause of treatment failure in patients with colon cancer. Gossypol is reported to exhibit antioxidant, anticancer, antivirus and antimicrobial properties. However, the effects of gossypol on cancer invasion and tumour growth of human colon cancer remain unclear. This study aimed to provide molecular evidence associated with the antimetastatic and anti-tumour effects of gossypol on human colorectal carcinoma (CRC) cells. Gossypol inhibited the viability of human colon cancer cells in a dose-dependent manner. Gossypol was sufficient to reduce the invasion, migration and adhesion in DLD-1 and COLO 205 cells. Zymography and western blot assay showed that gossypol reduced the activities and protein expression of urokinase-type plasminogen activator (u-PA), respectively. Gossypol suppressed the level of p-focal adhesion kinase (FAK) and epithelial-to-mesenchymal transition markers, including N-cadherin, fibronectin and vimentin. Gossypol also inhibited the lung metastasis of DLD-1 cells, as indicated by the nude mouse model. These results suggested that gossypol inhibited the metastatic properties of human colon cancer cells by targeting u-PA through the FAK pathway, suggesting that gossypol could be used as an adjuvant therapeutic agent for the treatment of human colon cancer cells.

Double immunofluorescent evidence that oxidative stress-associated activation of JNK/AP-1 signaling participates in neuropeptide-mediated appetite control.

Amphetamine (AMPH), an appetite suppressant, alters expression levels of neuropeptide Y (NPY) and cocaine- and amphetamine-regulated transcript (CART) in the hypothalamus. This study explored the potential role of cJun-N-terminal kinases (JNK) in appetite control, mediated by reactive oxygen species (ROS) and activator protein-1 (AP-1) in AMPH-treated rats. Rats were given AMPH daily for 4 days. Changes in feeding behavior and expression levels of hypothalamic NPY, CART, cFos, cJun, phosphorylated JNK (pJNK), as well as those of anti-oxidative enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GP) and glutathione S-transferase (GST), were examined and compared. Following AMPH treatment, food intake and NPY expression decreased, whereas the other proteins expression and AP-1/DNA binding activity increased. Both cerebral cJun inhibition and ROS inhibition attenuated AMPH anorexia and modified detected protein, revealing a crucial role for AP-1 and ROS in regulating AMPH-induced appetite control. Moreover, both pJNK/CART and SOD/CART activities detected by double immunofluorescent staining increased in hypothalamic arcuate nucleus in AMPH-treated rats. The results suggested that pJNK/AP-1 signaling and endogenous anti-oxidants participated in regulating NPY/CART-mediated appetite control in rats treated with AMPH. These findings advance understanding of the molecular mechanism underlying the role of pJNK/AP-1 and oxidative stress in NPY/CART-mediated appetite suppression in AMPH-treated rats.

Thymoquinone suppresses the proliferation of renal cell carcinoma cells via reactive oxygen species-induced apoptosis and reduces cell stemness.

Thymoquinone is a phytochemical compound isolated from Nigella sativa and has various biological effects, including anti-inflammation, antioxidation, and anticancer. Here, we further investigated the anticancer effects and associated molecular mechanism of 2-methyl-5-isopropyl-1,4-benzoquinone (thymoquinone) on human renal carcinoma cell lines 786-O and 786-O-SI3 and transitional carcinoma cell line BFTC-909. Results showed that thymoquinone significantly reduced cell viability, inhibited the colony formation of renal cancer cells, and induced cell apoptosis and mitochondrial membrane potential change in both cancer cells. In addition, thymoquinone also triggered the production of reactive oxygen species (ROS) and superoxide and the activation of apoptotic and autophagic cascade. ROS inhibition suppressed the caspase-3 activation and restored the decreased cell viability of 786-O-SI3 in response to thymoquinone. Autophagy inhibition did not restore the cell viability of 786-O-SI3 suppressed by thymoquinone. Moreover, thymoquinone suppressed the cell sphere formation and the expression of aldehyde dehydrogenase, Nanog, Nestin, CD44, and Oct-4 in 786-O-SI3 cells. The tumor-bearing model showed that thymoquinone in vivo inhibited the growth of implanted 786-O-SI3 cell. All these findings indicate that thymoquinone inhibits the proliferation of 786-O-SI3 and BFTC-909 cell possibly due to the induction of ROS/superoxide and the consequent apoptosis, suggesting that thymoquinone may be a potential anticancer supplement for genitourinary cancer.

Role of hypoxia-inducible factor-1α in regulating oxidative stress and hypothalamic neuropeptides-mediated appetite control.

Hypoxia-inducible factor 1 (HIF-1) is a transcriptional activator responding to hypoxia. Amphetamine (AMPH), however, can activate HIF-1 under normoxic conditions, which is associated with the co-activation of oxidative stress. Hypothalamic neuropeptides and anti-oxidative enzymes have been found to participate in amphetamine (AMPH)-mediated appetite control. The present study examined whether HIF-1 was involved in the oxidative stress and anorectic action of AMPH. Rats were daily treated with AMPH for 4 days, and expression levels of HIF-1α, superoxide dismutase (SOD), catalase, neuropeptide Y (NPY), proopiomelanocortin (POMC), phosphatidylinositol 3-kinase (PI3K), and nuclear factor-kappaB (NF-κB) were assessed and compared. Results revealed that feeding behavior and NPY decreased, whereas HIF-1α/DNA binding activity and SOD, POMC, PI3K, and NF-κB expression levels increased in AMPH-treated rats. Further experiment revealed that intracerebroventricular (i.c.v.) pretreatment with HIF-1α inhibitor modified feeding behavior and expression levels of hypothalamic protein assessed. Another experiment revealed that pretreatment (i.c.v.) with reactive oxygen species scavenger modulated HIF-1α, NPY, POMC, PI3K, and NF-κB expression levels in AMPH-treated rats. It is suggested that HIF-1α plays a functional role in the increase of oxidative stress and the modulation of NFκB/NPY/POMC-mediated appetite control in AMPH-treated rats. These findings advance the knowledge of HIF-1α in the regulation of central dopamine agonist-mediated appetite control.

Induction of apoptotic but not autophagic cell death by Cinnamomum cassia extracts on human oral cancer cells.

Cinnamomum cassia has been widely studied in different fields to reveal its antidiabetic, antidepressive, antiviral, anti-inflammatory, antiosteoporotic, and anticancer effects. Its antimalignant activities have been explored in lung cancer, breast cancer, colorectal cancer, and even oral cancer, but the detailed signaling mechanism and effects of this plant on animal models need to be clarified. In the current study, C. cassia extract (CCE) was used to investigate the antitumorigenesis mechanism in vitro and in vivo. The major constituents of CCE used in this study were coumarin, cinnamic acid, and cinnamic aldehyde. CCE reduced the viability, number, and colony formation of human oral cancer cells, and induced their apoptosis. Caspase-3 activation, Bcl-2 reduction, and phosphatidylserine inversion were involved in CCE-stimulated apoptosis. CCE also enhanced the expression of autophagic markers, including acidic vesicular organelle, microtubule-associated protein 1 light chain 3-I, autophagy-related protein 14, rubicon, and p62. The combined treatment of CCE and caspase inhibitor significantly restored mitochondrial membrane potential (Δ ψ m ) and cell viability. However, the combined treatment of CCE and autophagy inhibitor further reduced the cell viability indicating that autophagy might be a survival pathway of CCE-treated SASVO3 cells. In contrast, CCE treatment for 12 days did not adversely affect SASVO3 tumor-bearing nude mice. CCE also elicited dose-dependent effects on the decrease in tumor volume, tumor weight, and Ki-67 expression. These results suggested that CCE showed the potential for the complementary treatment of oral caner.

Viola Yedoensis Suppresses Cell Invasion by Targeting the Protease and NF-κB Activities in A549 and Lewis Lung Carcinoma Cells.

Cancer metastasis is a vital trait in malignancies with complicated early diagnosis and therapeutic management. Therefore, the development of new remedies and the utilization of natural medicines that target metastasis are of great interest and have been studied extensively. Chinese medicinal herbs have various anti-carcinogenesis properties; however, the in vitro effect and mechanism of Viola yedoensis on cancer cell metastasis remains poorly understood. V. yedoensis extracts (VYE) can suppress the invasion of a highly metastatic human lung cancer cell line, A549 cells. According to gelatin zymography and casein zymography assays, VYE inhibited the activities of matrix metalloproteinases (MMPs) and urokinase-type plasminogen activator (u-PA). The results of reverse transcription-polymerase chain reaction and Western blotting revealed that VYE can alter the expression of proteinase inhibitor. VYE also suppressed the DNA binding activity of nuclear factor-kappa B. We concluded that VYE may inhibit tumor invasion by suppressing the activities of MMP and u-PA in lung cancer cells.

Role of hypothalamic leptin-LepRb signaling in NPY-CART-mediated appetite suppression in amphetamine-treated rats.

Leptin is an adipose tissue hormone which plays an important role in regulating energy homeostasis. Amphetamine (AMPH) is a drug of appetite suppressant, which exerts its effect by decreasing the expression of hypothalamic neuropeptide Y (NPY) and increasing that of cocaine- and amphetamine-regulated transcript (CART). This study investigated whether leptin, the leptin receptor (LepRb) and the signal transducer and activator of transcription-3 (STAT3) were involved in NPY/CART-mediated appetite suppression in AMPH-treated rats. Rats were given AMPH daily for four days, and changes in the levels of blood leptin and hypothalamic NPY, CART, LepRb, Janus kinases 2 (JAK2), and STAT3 were assessed and compared. During the AMPH treatment, blood leptin levels and hypothalamic NPY expression decreased, with the largest reduction observed on Day 2. By contrast, the expression of hypothalamic CART, LepRb, JAK2, and STAT3 increased, with the maximum response on Day 2. Furthermore, the binding activity of pSTAT3/DNA increased and was expressed in similar pattern to that of CART, LepRb, and JAK2. An intracerebroventricular infusion of NPY antisense 60min prior to AMPH treatment increased the levels of leptin, as well as the expression in LepRb, JAK2, and CART, whereas an infusion of STAT3 antisense decreased these levels and the expression of these parameters. The results suggest that blood leptin and hypothalamic LepRb-JAK2-STAT3 signaling involved in NPY-CART-regulated appetite suppression in AMPH-treated rats. The findings may aid understanding the role of leptin-LepRb during the treatment of anorectic drugs.

Cinnamomum Cassia Extracts Suppress Human Lung Cancer Cells Invasion by Reducing u-PA/MMP Expression through the FAK to ERK Pathways.

Cinnamomum cassia exhibits antioxidative, apoptotic, and cytostatic properties. These activities have been attributed to the modulation of several biological processes and are beneficial for possible pharmaceutical applications. However, the potential of C. cassia in retarding lung adenocarcinoma cells metastasis remains ambiguous. We determined whether C. cassia extract (CCE) reduces metastasis of human lung adenocarcinoma cells. The results showed that CCE treatment (up to 60 µg/mL) for 24 h exhibited no cytotoxicity on the A549 and H1299 cell lines but inhibited the motility, invasiveness, and migration of these cells by repressing matrix metalloproteinase (MMP)-2 and urokinase-type plasminogen activator (u-PA). CCE also impaired cell adhesion to collagen. CCE significantly reduced p-focal adhesion kinase (FAK) Tyr397, p-FAK Tyr925, p-extracellular signal-regulated kinases (ERK)1/2, and Ras homolog gene family (Rho)A expression. CCE showed anti-metastatic activity of A549 and H1299 cells by repressing u-PA/MMP-2 via FAK to ERK1/2 pathways. These findings may facilitate future clinical trials of lung adenocarcinoma chemotherapy to confirm the promising results.

Duchesnea indica extract suppresses the migration of human lung adenocarcinoma cells by inhibiting epithelial-mesenchymal transition.

Epithelial-mesenchymal transition (EMT) is a process through which epithelial cells are transformed into mesenchymal cells; EMT diminishes cell polarity and cell-cell adhesion in cancer cells, leading to enhanced migratory and invasive properties. In this experiment, zymography, cell invasion, and migration assays were performed. Results indicated that Duchesnea indica extracts (DIE) inhibited highly metastatic A549 and H1299 cells by reducing the secretions of matrix metalloproteinase-2 and urokinase-type plasminogen activator. Cell adhesion assay also demonstrated that DIE reduced the cell adhesion properties. Western blot analysis showed that DIE down-regulated the expression of N-cadherin, fibronectin, and vimentin, which are mesenchymal markers, and enhanced that of E-cadherin, which is an epithelial marker. In vivo study showed that tumor growth was significantly reduced in BALB/c nude mouse xenograft model administered with oral gavage of DIE. Therefore, DIE could be exhibits potential as a phytochemical-based platform for prevention and treatment of lung cancer. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 2053-2063, 2017.

Cinnamomum cassia extracts reverses TGF-ß1-induced epithelial-mesenchymal transition in human lung adenocarcinoma cells and suppresses tumor growth in vivo.

Metastasis is the most common cause of cancer-related mortality in patients, and epithelial-mesenchymal transition (EMT) is essential for cancer metastasis and antidrug resistance. Cinnamomum cassia has several antioxidative, anti-inflammatory, and anticancer biological effects. However, the anti-EMT effect of C. cassia in human lung carcinoma is rarely reported. In this study, we determined whether C. cassia extracts (CCE) reduces the EMT and tumor growth of human lung adenocarcinoma cells. CCE inhibited the transforming growth factor (TGF)-ß1-induced cell motility and invasiveness of A549 and H1299 cells by repressing matrix metalloproteinase-2 and urokinase-type plasminogen activator as well as impaired cell adhesion to collagen. CCE also affected the TGF-ß1-induced EMT by downregulating the expression of vimentin and fibronectin and upregulating E-cadherin. The nude mice xenograft model showed that CCE reduced A549 tumor growth. Thus, CCE possesses antimetastatic activity of A549 and H1299 cells by affecting EMT and suppressing A549 tumor growth in vivo. This result suggested that CCE could be used as an antimetastatic agent or as an adjuvant for anticancer therapy.

Participation of ghrelin signalling in the reciprocal regulation of hypothalamic NPY/POMC-mediated appetite control in amphetamine-treated rats.

Hypothalamic neuropeptide Y (NPY) and proopiomelanocortin (POMC) have been documented to participate in amphetamine (AMPH)-induced appetite suppression. This study investigated whether ghrelin signalling is associated with changes in NPY/POMC-mediated appetite control. Rats were given AMPH daily for four days, and changes in food intake, body weight, plasma ghrelin, hypothalamic NPY, melanocortin 3 receptor (MC3R), ghrelin O-acyltransferase (GOAT), acyl ghrelin (AG) and ghrelin receptor (GHSR1a) were examined and compared. Food intake, body weight and NPY expression decreased, while MC3R expression increased and expressed reciprocally to NPY expression during AMPH treatment. Plasma ghrelin and hypothalamic AG/GOAT/GHSR1a expression decreased on Day 1 and Day 2, which was associated with the positive energy metabolism, and returned to normal levels on Day 3 and Day 4, which was associated with the negative energy metabolism; this expression pattern was similar to that of NPY. Infusion with a GHSR1a antagonist or an NPY antisense into the brain enhanced the decrease in NPY and AG/GOAT/GHSR1a expression and the increase in MC3R expression compared to the AMPH-treated group. Peripheral ghrelin and the central ghrelin system participated in the regulation in AMPH-induced appetite control. These results shed light on the involvement of ghrelin signalling in reciprocal regulation of NPY/POMC-mediated appetite control and may prove useful for the development of anti-obesity drugs.

Koelreuteria Formosana Extract Induces Growth Inhibition and Cell Death in Human Colon Carcinoma Cells via G2/M Arrest and LC3-II Activation-Dependent Autophagy.

Autophagy is a self-destructive process that degrades cytoplasmic constituents. In our previous study, Koelreuteria formosana ethanolic extract (KFEE), which is obtained from natural plants endemic to Taiwan, has inhibited cell metastasis in renal carcinoma cells. However, the anticancer effects of KFEE on colon cancer remain unclear. In this study, KFEE exerted a strong cytotoxic effect on DLD-1 and COLO 205 human colorectal cancer cell lines. KFEE effectively inhibited cancer cell proliferation, induced G2/M-phase arrest associated with downregulaton of cyclin E, cyclin B and cdc25C and upregulation of p21, and induced cell death by activating autophagy but did not cause apoptotic cell death. Exposed KFEE cells showed increased levels of acridine orange, autophagic vacuoles, and LC3-II proteins, which are specific autophagic markers. Bcl-2, p-Akt, and p-mTOR levels, which have been implicated in autophagic downregulation, were decreased after KFEE treatment. Autophagy inhibitor 3-methyladenosine and bafilomycin-A1 and genetic silencing of LC3 attenuated KFEE-induced growth inhibition. These findings suggested that KFEE causes cytostatic effect through autophagy. In xenograft studies, oral administration of KFEE had significantly inhibited the tumor growth in nude mice that had received subcutaneous injection of DLD-1 cells. KFEE is a promising candidate in phytochemical-based, mechanistic, and pathway-targeted cancer prevention strategies.

3-Hydroxyflavone inhibits human osteosarcoma U2OS and 143B cells metastasis by affecting EMT and repressing u-PA/MMP-2 via FAK-Src to MEK/ERK and RhoA/MLC2 pathways and reduces 143B tumor growth in vivo.

Many natural flavonoids have cytostatic and apoptotic properties; however, we little know whether the effect of synthetic 3-hydroxyflavone on metastasis and tumor growth of human osteosarcoma. Here, we tested the hypothesis that 3-hydroxyflavone suppresses human osteosarcoma cells metastasis and tumor growth. 3-hydroxyflavone, up to 50 µM without cytotoxicity, inhibited U2OS and 143B cells motility, invasiveness and migration by reducing matrix metalloproteinase (MMP)-2 and urokinase-type plasminogen activator (u-PA) and also impaired cell adhesion to gelatin. 3-hydroxyflavone significantly reduced p-focal adhesion kinase (FAK) Tyr397, p-FAK Tyr925, p-steroid receptor coactivator (Src), p-mitogen/extracellular signal-regulated kinase (MEK)1/2, p-myosin light chain (MLC)2 Ser19, epithelial cell adhesion molecule, Ras homolog gene family (Rho)A and fibronectin expressions. 3-hydroxyflavone also affected the epithelial-mesenchymal transition (EMT) by down-regulating expressions of Vimentin and α-catenin with activation of the transcription factor Slug. In nude mice xenograft model and tail vein injection model showed that 3-hydroxyflavone reduced 143B tumor growth and lung metastasis. 3-hydroxyflavone possesses the anti-metastatic activity of U2OS and 143B cells by affecting EMT and repressing u-PA/MMP-2 via FAK-Src to MEK/ERK and RhoA/MLC2 pathways and suppresses 143B tumor growth in vivo. This may lead to clinical trials of osteosarcoma chemotherapy to confirm the promising result in the future.