Molecular Mechanisms and Metabolomics of Natural Polyphenols Interfering with Breast Cancer Metastasis

Biological Activities of Molecules Derived from Olea europaea L. Tested In Vitro

BACKGROUND

Extra virgin olive oil is a typical food of the Mediterranean area, obtained by pressing Olea europaea L. fruits. Its polyphenols have been studied for their antioxidant function and protective action against cancer and chronic kidney disease. In this in vitro study, we tested titrated extracts from Olea europaea L. on a human embryonic kidney 293 (HEK-293E) cell line, regarding their pro-apoptotic and antiproliferative capacities, using " IncuCyte® S3 Live-Cell Analysis System".

MATERIALS AND METHODS

We selected Olea europaea L. active compounds like hydroxytyrosol (HT) and oleuropein (OLE). These extracts were tested at different concentrations and characterized by HPLC-DAD-MS for the content in secondary active metabolites. The real-time observation of cell behavior was performed by IncuCyte, which can quantitatively analyze the cell proliferation and death.

RESULTS

This study showed that all the tested extracts can significantly inhibit cellular growth at 50 µM but the reduced proliferation is not related to an increase in cellular apoptosis. Instead, the same analysis performed by using extracts at 100 µM reveals that they can inhibit cellular growth, further inducing cellular apoptosis.

CONCLUSIONS

The results on the HEK-293E cells confirmed the antiproliferative and proapoptotic actions of active compounds from an Olea europaea L. matrix in this cell line.

Notch3 restricts metastasis of breast cancers through regulation of the JAK/STAT5A signaling pathway

PURPOSE

To explore the potential role of signal transducer and activator of transcription 5A (STAT5A) in the metastasis of breast cancer, and its mechanism of regulation underlying.

METHODS AND RESULTS

TCGA datasets were used to evaluate the expression of STAT5A in normal and different cancerous tissues through TIMER2.0, indicating that STAT5A level was decreased in breast cancer tissues compared with normal ones. Gene Set Enrichment Analysis predicted that STAT5A was associated with the activation of immune cells and cell cycle process. We further demonstrated that the infiltration of immune cells was positively associated with STAT5A level. Influorescence staining revealed the expression and distribution of F-actin was regulated by STAT5A, while colony formation assay, wound healing and transwell assays predicted the inhibitory role of STAT5A in the colony formation, migratory and invasive abilities in breast cancer cells. In addition, overexpression of the Notch3 intracellular domain (N3ICD), the active form of Notch3, resulted in the increased expression of STAT5A. Conversely, silencing of Notch3 expression by siNotch3 decreased STAT5A expression, supporting that STAT5A expression is positively associated with Notch3 in human breast cancer cell lines and breast cancer tissues. Mechanistically, chromatin immunoprecipitation showed that Notch3 was directly bound to the STAT5A promoter and induced the expression of STAT5A. Moreover, overexpressing STAT5A partially reversed the enhanced mobility of breast cancer cells following Notch3 silencing. Low expression of Notch3 and STAT5A predicted poorer prognosis of patients with breast cancer.

CONCLUSION

The present study demonstrates that Notch3 inhibits metastasis in breast cancer through inducing transcriptionally STAT5A, which was associated with tumor-infiltrating immune cells, providing a novel strategy to treat breast cancer.

Co-administration of Chrysin and Luteolin with Cisplatin and Topotecan Exhibits a Variable Therapeutic Value in Human Cancer Cells, HeLa

Combinational treatment is a promising strategy for better cancer treatment outcomes. Chrysin and luteolin have demonstrated effective anticancer activity. Cisplatin and topotecan are commonly used for the treatment of human cancers. However, various side effects including drug resistance are an imperative restriction to use them as pharmacological therapy. Therefore, the aim was to use these agents in combination with flavones for better efficacy. In the present study, it was found that the combination of chrysin and cisplatin and luteolin and cisplatin significantly improved the anticancer effect as both the combinations showed synergistic interactions [combinational index (CI < 1)]. Remarkably, the combination of chrysin and luteolin with topotecan depicted the antagonistic interaction (CI > 1). Further, increased expression of the pro-apoptotic proteins Bax and caspase 8 and the inhibition of the antiapoptotic protein Bcl-2 were instituted in the synergistic doses (chrysin + cisplatin and luteolin + cisplatin), hence promoting apoptosis. Also, it was found that the synergistic combination inhibited the migration of HeLa cells by downregulation of metalloproteases and upregulation of TIMPs. However, there are no significant changes depicted in the antagonistic combinations which support their role in their antagonistic effects. Based on these results, it can be inferred that the two or more drug combinations need to be explored well for their interaction to enhance the therapeutic outcomes.

Antitumoral activity of Caralluma europaea on colorectal and prostate cancer cell lines

Caralluma europaea is a medicinal plant used in Moroccan popular medicine, which has been employed as a remedy attributed to its anti-inflammatory, antipyretic, antinociceptive, antidiabetic, neuroprotective, and antiparasitic properties. The aim of the present study was to investigate the antitumor activity of both the methanolic and aqueous extract of C. europaea. The effects of increasing concentrations of aqueous and methanolic extracts on human colorectal cancer HT-29 and HCT116 cell lines and human prostate cancer PC3 and DU145 cell lines were examined on cell proliferation using MTT assay and cell cycle analysis. The induction of apoptosis was also assessed by determining protein expression of caspase-3 and poly-ADP-ribose polymerase (PARP) cleavage by western blot. The methanolic extract of C. europaea exerted significant antiproliferative effects on HT-29 (IC₅₀ values 73 µg/ml), HCT116 (IC₅₀ values 67 µg/ml), PC3 (IC₅₀ values 63 µg/ml) and DU145 cells (IC₅₀ values 65 µg/ml) after 48 hr treatment. Further, incubation with methanolic extract of C. europaea induced cell cycle arrest in G1 phase and an apoptotic process for all treated cell lines. In conclusion, the present results suggest that C. europaea, exhibited that these natural compounds are significant apoptosis inducers which may have considerable potential for development of effective natural product anticancer agents.

Natural product Eriocalyxin B suppressed triple negative breast cancer metastasis both in vitro and in vivo

Breast cancer is the most commonly diagnosed cancer among women, and its metastasis to distant organs accounts for the majority of death. Eriocalyxin B (Eri B), an ent-kaurane diterpenoid isolating from Isodon eriocalyx var. laxiflora, has previously been reported to have anti-tumor and anti-angiogenic effects in breast cancer. Here, we investigated the effect of Eri B on cell migration and adhesion in triple negative breast cancer (TNBC) cells, as well as aldehyde dehydrogenases 1 family member A1 (ALDH1A1) expression, colony- and sphere-formation in cancer stem cell (CSC) enriched MDA-MB-231 cells. The in vivo anti-metastatic activities of Eri B were determined in 3 different breast tumor-bearing mouse models. Our results indicated that Eri B inhibited TNBC cell migration and adhesion to extracellular matrix proteins, and also reduced ALDH1A1 expression and colony formation in CSC-enriched MDA-MB-231 cells. The metastasis-related pathways, such as epidermal growth factor receptor/ mitogen-activated protein kinase kinases 1/2/ extracellular regulated protein kinase signaling altered by Eri B was firstly shown in MDA-MB-231 cells. The potent anti-metastatic efficacies of Eri B were demonstrated in breast xenograft-bearing mice and syngeneic breast tumor-bearing mice. Gut microbiome analysis results revealed the change in the diversity and composition of microbiome after Eri B treatment, and the potential pathways that are involved in the anti-cancer efficacy of Eri B. In conclusion, Eri B was shown to inhibit breast cancer metastasis in both in vitro and in vivo models. Our findings further support the development of Eri B as an anti-metastatic agent for breast cancer.

Antitumor Effects of Microencapsulated Gratiola officinalis Extract on Breast Carcinoma and Human Cervical Cancer Cells In Vitro

Flavonoid-containing Gratiola officinalis extract has been studied in relation to breast carcinoma and human cervical cancer cells in encapsulated and native form. Encapsulation was realized in polymer shells, which were formed by the layer-by-layer method using sequential adsorption of poly(allylamine hydrochloride) and poly(sodium 4-styrenesulfonate) on the destructible cores. The extract was prepared by the author's method and characterized using high performance liquid chromatography. By means of optical and fluorescent microscopy, cell changes under the action of pure and encapsulated extracts were comprehensively studied, and statistical analysis was carried out. Cells were stained with propidium iodide, acridine orange, and Hoechst 33258. A fluorescence microscope with a digital video camera were used for cell imaging. The encapsulated extract caused 100% death of breast cancer SKBR-3 cells and 34% death of cervical cancer HeLa cells and prevented the formation of autophagosomes in both cultures. Analysis of the viability and morphological features of tumor cells under the action of microencapsulated extract allows us to consider microencapsulation as an effective strategy for delivering Gratiola officinalis extract to tumor cells and a promising way to overcome the protective autophagy.

Phytochemicals as Chemo-Preventive Agents and Signaling Molecule Modulators: Current Role in Cancer Therapeutics and Inflammation

Cancer is one of the deadliest non communicable diseases. Numerous anticancer medications have been developed to target the molecular pathways driving cancer. However, there has been no discernible increase in the overall survival rate in cancer patients. Therefore, innovative chemo-preventive techniques and agents are required to supplement standard cancer treatments and boost their efficacy. Fruits and vegetables should be tapped into as a source of compounds that can serve as cancer therapy. Phytochemicals play an important role as sources of new medication in cancer treatment. Some synthetic and natural chemicals are effective for cancer chemoprevention, i.e., the use of exogenous medicine to inhibit or impede tumor development. They help regulate molecular pathways linked to the development and spread of cancer. They can enhance antioxidant status, inactivating carcinogens, suppressing proliferation, inducing cell cycle arrest and death, and regulating the immune system. While focusing on four main categories of plant-based anticancer agents, i.e., epipodophyllotoxin, camptothecin derivatives, taxane diterpenoids, and vinca alkaloids and their mode of action, we review the anticancer effects of phytochemicals, like quercetin, curcumin, piperine, epigallocatechin gallate (EGCG), and gingerol. We examine the different signaling pathways associated with cancer and how inflammation as a key mechanism is linked to cancer growth.

Integrative analysis of plasma metabolomics and proteomics reveals the metabolic landscape of breast cancer

BACKGROUND

Breast cancer (BC) is the most commonly diagnosed cancer. Currently, mammography and breast ultrasonography are the main clinical screening methods for BC. Our study aimed to reveal the specific metabolic profiles of BC patients and explore the specific metabolic signatures in human plasma for BC diagnosis.

METHODS

This study enrolled 216 participants, including BC patients, benign patients, and healthy controls (HC) and formed two cohorts, one training cohort and one testing cohort. Plasma samples were collected from each participant and subjected to perform nontargeted metabolomics and proteomics. The metabolic signatures for BC diagnosis were identified through machine learning.

RESULTS

Metabolomics analysis revealed that BC patients showed a significant change of metabolic profiles compared to HC individuals. The alanine, aspartate and glutamate pathways, glutamine and glutamate metabolic pathways, and arginine biosynthesis pathways were the critical biological metabolic pathways in BC. Proteomics identified 29 upregulated and 2 downregulated proteins in BC. Our integrative analysis found that aspartate aminotransferase (GOT1), L-lactate dehydrogenase B chain (LDHB), glutathione synthetase (GSS), and glutathione peroxidase 3 (GPX3) were closely involved in these metabolic pathways. Support vector machine (SVM) demonstrated a predictive model with 47 metabolites, and this model achieved a high accuracy in BC prediction (AUC = 1). Besides, this panel of metabolites also showed a fairly high predictive power in the testing cohort between BC vs HC (AUC = 0.794), and benign vs HC (AUC = 0.879).

CONCLUSIONS

This study uncovered specific changes in the metabolic and proteomic profiling of breast cancer patients and identified a panel of 47 plasma metabolites, including sphingomyelins, glutamate, and cysteine could be potential diagnostic biomarkers for breast cancer.

A Comprehensive Review on the Anti-Cancer Effects of Oleuropein

In Mediterranean cuisine and culture, olive oil and olive fruits play a significant role. Many people believe that those who consume olive oil and its fruit live longer and have a decreased risk of illness. Olive leaves were used to treat a range of diseases in ancient times, including malaria fever and lower earaches. Although it was not understood at the time what key components were responsible for these effects because they had not yet been discovered, Oleuropein is now recognized as one of the primary elements in immature olive fruits and leaves. Later research was carried out to determine the effects of this molecule, and it was determined that it functions as an antioxidant. Oleuropein consumption has aided in cancer treatment over the years, and this was assumed to be owing to its antioxidant properties. Oleuropein’s effects on cancer, however, go beyond that; it is now known that Oleuropein functions as both an anti-proliferative and an apoptotic promoter in many cancer cells. The kinetics and dosages of Oleuropein and the mechanisms behind its involvement and effects in cancer are explored in this review. Finally, the effects of Oleuropein in combination with anticancer medicines are investigated.

Inhibition of Glutamine Cellular Uptake Contributes to the Cytotoxic Effect of Xanthohumol in Triple-Negative Breast Cancer Cells

Breast cancer constitutes the most incident cancer and one of the most common causes of cancer-related death. "Glutamine addiction", an important metabolic feature of cancer cells, is dependent on supply of this amino acid from external sources. In this study, the effect of several polyphenols (catechin, epicatechin, EGCG, catechin:lysine, naringenin, hesperidin, malvidin, delphinidin, kaempferol, quercetin, rutin, myricetin, resveratrol, xanthohumol, and chrysin) upon glutamine (³H-GLN) uptake by human breast epithelial adenocarcinoma cell lines with distinct characteristics (MCF-7 and MDA-MB-231) was assessed.Several polyphenols interfere with ³H-GLN uptake by both cell lines. Xanthohumol markedly decreases total and Na⁺-dependent ³H-GLN uptake and showed a cytotoxic and anti-proliferative effect in MDA-MB-231 cells. Xanthohumol is as an uncompetitive inhibitor of Na⁺-dependent ³H-GLN uptake and inhibits GPNA (L-γ-glutamyl-p-nitroanilide)-sensitive, both ASCT2 (alanine, serine, cysteine transporter 2)-mediated and non-ASCT2-mediated ³H-GLN uptake. Xanthohumol does not interfere with the transcription rates of ASCT2. The cytotoxic effect of xanthohumol, but not its anti-proliferative effect, is GPNA-sensitive and related to ASCT2 inhibition. Combination of xanthohumol with the breast cancer chemotherapeutic agent doxorubicin results in an additive anti-proliferative, but not cytotoxic effect.We conclude that targeting glutamine uptake might constitute a potential interesting strategy for triple-negative breast cancer.

Dietary Intake of Polyphenols and the Risk of Breast Cancer: a Case-Control Study

Despite mounting evidence that dietary polyphenols might have a protective role against the risk of breast cancer (BC), few studies have assessed the relationship between intake of polyphenol classes and subclasses with BC. Thus, we examined the relationship between dietary polyphenol classes and individual polyphenol subclasses and the risk of BC. Overall, 134 newly diagnosed BC patients and 267 healthy hospitalized controls were studied. Dietary intake was assessed using a validated 168-item food frequency questionnaire (FFQ). To estimate dietary intake of polyphenols, polyphenol content (flavonoids, lignans, stilbenes and phenolic acids) of 80 food items were derived from an updated version of the phenol explorer database containing information on the effects of food processing on polyphenol content. The dietary polyphenol intake was calculated by matching the subjects' food consumption data with our polyphenol content database. Multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Controls had higher intake of total polyphenol (marginally significant; p = 0.07), hydroxycinnamic acid (marginally significant; p = 0.05) and lignan (p = 0.01). After adjusting for potential confounders, high consumption of lignans (highest vs. lowest tertile: OR, 0.51; 95% CI, 0.26–0.97; p for trend = 0.04) associated with decreased risk of BC. There was no significant relationship between intake of other polyphenols and risk of BC. Our findings suggest that high lignan intake is associated with a reduced risk of BC.

Metastatic Breast Cancer, Organotropism and Therapeutics: A Review

The final stage of breast cancer involves spreading breast cancer cells to the vital organs like the brain, liver lungs and bones in the process called metastasis. Once the target organ is overtaken by the metastatic breast cancer cells, its usual function is compromised causing organ dysfunction and death. Despite the significant research on breast cancer metastasis, it's still the main culprit of breast cancer-related deaths. Exploring the complex molecular pathways associated with the initiation and progression of breast cancer metastasis could lead to the discovery of more effective ways of treating the devastating phenomenon. The present review article highlights the recent advances to understand the complexity associated with breast cancer metastases, organotropism and therapeutic advances.

Assessment of Rhamnus alaternus Leaves Extract: Phytochemical Characterization and Antimelanoma Activity

Rhamnus alaternus (Rhamnaceae) has been used as a laxative, purgative, diuretic, antihypertensive, and depurative. However, few scientific research studies on its antimelanoma activity have been reported. This study aimed to investigate the in vitro antimelanoma effect of an enriched total oligomer flavonoid (TOF) extract, from R. alaternus, and to identify its phytochemical compounds. The chemical composition of TOF extract was assessed by HPLC-electrospray ionization tandem mass spectrometry (HPLC/ESI-MS²) analysis. Antimelanoma activity was determined on cultured tumor cell B16F10 by the crystal violet assay, the alkaline comet assay, acridine orange/ethidium bromide (AO/EB), annexin V-fluorescein isothiocyanate/ propidium iodide (V-FITC/PI) staining, the cell cycle distribution, and the wound healing assay. Regarding chemical composition, a mixture of quercetin diglucoside, quercetin-3-O-neohesperidoside, kaempferol-3-O-(2G-α-L-rhamnosyl)-rutinoside, rhamnetin hexoside, kaempferol-3-O-rutinoside, rhamnocitrin hexoside, pilosin hexoside, apigenin glucoside, and kaempferol-3-O-glucoside was identified as major phytochemical compounds of the extracts. TOF extract inhibits melanoma B16F10 cell proliferation in dose-dependent manner. The induction of apoptosis was confirmed by comet assay, AO/EB, and annexin V-FITC/PI test. TOF extract could also induce S phase cell cycle, inhibit, and delay the cell migration of B16F10 cells. The findings showed that TOF extract from R. alaternus could be a potentially good candidate for future use in alternative antimelanoma treatments.

Curcumin and cancer biology: Focusing regulatory effects in different signalling pathways

Cancer is the second-leading cause of death worldwide. Till date, many such effective treatments are available, for example chemotherapy, surgery, and radiation therapy, but there are severe associated side effects, such as increased infection risk, constipation, hair loss, anaemia, among others. Thus, the need for effective therapeutic strategies and screening methodology arises. Researchers around the world are increasingly trying to discover anticancer therapies with as few side effects as possible and many are now focusing on phytochemicals, like curcumin. Curcumin is a bright yellow substance isolated from the plant rhizomes of Curcuma longa L. To this molecule a high therapeutic benefit has been underlined, being able to alter the development of cancer by different mechanisms, such as regulating multiple microRNA expression, modifying a series of signalling pathways, that is, Akt, Bcl-2, PTEN, p53, Notch, and Erbb. Another major pathway that curcumin targets is the matrix metalloproteinase (MMP) gene expression. In fact, MMPs are responsible for the degradation of the cell-extracellular matrix, which can lead to the diseased condition and many different pathways contribute to its activity, such as JAK/STAT, NF-κB, MAPK/ERK, COX-2, ROS, TGF-β, among others. In this review, we have attempted to describe the curcumin regulatory effect on different cell signalling pathways involved in the progression of different types of cancers.

The Role of Vitamin E in Breast Cancer Treatment and Prevention: Current Perspectives

Background:

Regarding the multifactorial etiology of breast cancer, food choices, as well as dietary intake, are the main modified factors in cancer prevention. In this sense, understanding molecular pathways involved in breast cancer proliferation can help determine the mechanisms of action of organic compounds such as antioxidant vitamins that are known to protect against cancer.

Objective:

Assess the mechanism of action of vitamin E in breast cancer modulation, with emphasis on important markers of tumor development.

Methods:

It is a systematic review carried out in PubMed and Web of Science databases, from the last 5 years, in Portuguese, English and Spanish. The following terms were selected according to The Medical Subject Headings (MeSH): “breast cancer” OR “breast neoplasms”, “tocopherol” OR “tocotrienols” OR “vitamin E”, as equated terms.

Results:

A total of 595 articles were found and 25 were selected according to inclusion criteria. Vitamin E has been related to suppression/overexpression of important tumorigenic pathways, mainly associated with proliferation, energy metabolism, chemosensitivity and invasion/metastasis. Clinical studies of vitamin E supplementation are needed to assess the dose/response effect on breast cancer patients.

Conclusion:

The safety of vitamin E supplementation is still controversial due to current studies design available. However, when vitamin E is supplemented, the dose and therapeutic regimen must be carefully decided, including the route of administration and breast cancer subtypes to enhance desired effects and minimize unwanted side effects.

Effects of oleuropein on tumor cell growth and bone remodelling: Potential clinical implications for the prevention and treatment of malignant bone diseases

Oleuropein (Ole) is the main bioactive phenolic compound present in olive leaves, fruits and olive oil. This molecule has been shown to exert beneficial effects on several human pathological conditions. In particular, recent preclinical and observational studies have provided evidence that Ole exhibits chemo-preventive effects on different types of human tumors. Studies undertaken to elucidate the specific mechanisms underlying these effects have shown that this molecule may thwart several key steps of malignant progression, including tumor cell proliferation, survival, angiogenesis, invasion and metastasis, by modulating the expression and activity of several growth factors, cytokines, adhesion molecules and enzymes involved in these processes. Interestingly, experimental observations have highlighted the fact that most of these signalling molecules also appear to be actively involved in the homing and growth of disseminating cancer cells in bones and, ultimately, in the development of metastatic bone diseases. These findings, and the experimental and clinical data reporting the preventive activity of Ole on various pathological conditions associated with a bone loss, are indicative of a potential therapeutic role of this molecule in the prevention and treatment of cancer-related bone diseases. This paper provides a current overview regarding the molecular mechanisms and the experimental findings underpinning a possible clinical role of Ole in the prevention and development of cancer-related bone diseases.

Annurca apple polyphenol extract promotes mesenchymal-to-epithelial transition and inhibits migration in triple-negative breast cancer cells through ROS/JNK signaling

Aberrant activation of epithelial-to-mesenchymal transition has been shown to correlate with triple-negative breast cancer (TNBC) progression and metastasis. Thus, the induction of the reverse process might offer promising opportunities to restrain TNBC metastatic spreading and related mortality. Recently, the Annurca apple polyphenol extract (APE) has been highlighted as a multi-faceted agent that selectively kills TNBC cells by ROS generation and sustained JNK activation. Here, by qualitatively and quantitatively monitoring the real-time movements of live cells we provided the first evidence that APE inhibited the migration of MDA-MB-231 and MDA-MB-468 TNBC cells and downregulated metalloproteinase-2 and metalloproteinase-9. In MDA-MB-231 cells APE decreased SMAD-2/3 and p-SMAD-2/3 levels, increased E-cadherin/N-cadherin protein ratio, induced the switch from N-cadherin to E-cadherin expression and greatly reduced vimentin levels. Confocal and scanning electron microscopy imaging of APE-treated MDA-MB-231 cells evidenced a significant cytoskeletal vimentin and filamentous actin reorganization and revealed considerable changes in cell morphology highlighting an evident transition from the mesenchymal to epithelial phenotype with decreased migratory features. Notably, all these events were reverted by N-acetyl-l-cysteine and JNK inhibitor SP600125 furnishing evidence that APE exerted its effects through the activation of ROS/JNK signaling. The overall data highlighted APE as a potential preventing agent for TNBC metastasis.

The FTO/miR-181b-3p/ARL5B signaling pathway regulates cell migration and invasion in breast cancer

Background

N6‐methyladenosine (m⁶A) RNA modification has been demonstrated to be a significant regulatory process in the progression of various tumors, including breast cancer. Fat mass and obesity‐associated (FTO) enzyme, initially known as the obesity‐related protein, is the first identified m⁶A demethylase. However, the relationship between FTO and breast cancer remains controversial. In this study, we aimed to elucidate the role and clinical significance of FTO in breast cancer and to explore the underlying mechanism.

Methods

We first investigated the expression of FTO in breast cancer cell lines and tissues by quantitative reverse transcription‐PCR (qRT‐PCR), Western blotting, and immunohistochemistry. Wound healing assay and Transwell assay were performed to determine the migration and invasion abilities of SKBR3 and MDA‐MB453 cells with either knockdown or overexpression of FTO. RNA sequencing (RNA‐seq) was conducted to decipher the downstream targets of FTO. qRT‐PCR, luciferase reporter assay, and Western blotting were employed to confirm the existence of the FTO/miR‐181b‐3p/ARL5B axis. The biological function of ADP ribosylation factor like GTPase 5B (ARL5B) in breast cancer cells was evaluated by wound healing assay and Transwell invasion assay.

Results

High FTO expression was observed in human epidermal growth factor receptor 2 (HER2)‐positive breast cancer, predicting advanced progression (tumor size [P < 0.001], nuclear grade [P = 0.001], peritumoral lymphovascular invasion [P < 0.001), lymph node metastasis [P = 0.002], and TNM stage [P = 0.001]) and poor prognosis. Moreover, FTO promoted cell invasion and migration in vitro. Mechanistically, RNA‐seq and further confirmation studies suggested that FTO up‐regulated ARL5B by inhibiting miR‐181b‐3p. We further verified that ARL5B also displayed carcinogenic activity in breast cancer cells.

Conclusion

Our work demonstrated the carcinogenic activity of FTO in promoting the invasion and migration of breast cancer cells via the FTO/miR‐181b‐3p/ARL5B signaling pathway.

Alpinumisoflavone triggers GSDME-dependent pyroptosis in esophageal squamous cell carcinomas

Esophageal squamous cell carcinoma (ESCC) presents a common human malignancy in the digestive system. We aimed to explore the critical effects of alpinumisoflavone (AIF) on ESCC in vitro and in vivo. The cell counting kit-8 assay was used to determine cell viability. Colony formation assay was employed to examine the effect of AIF on the long-term growth of ESCC cells. Cell apoptosis was determined by flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. Cell morphologies were observed by light microscopy. The enzyme-linked immunosorbent assay was performed to examine the lactate dehydrogenase release from AIF-treated cells. Immunofluorescent labeling was utilized to examine AIF-induced GSDME expression. Western blot was employed to determine the expression levels of the associated proteins. Immunohistochemistry was performed to determine the localization and expression of the associated proteins in mice tumor tissues. AIF inhibited ESCC cell viability and suppressed cell growth in a dose- and time-dependent fashion. Results showed that AIF promoted apoptosis in ESCC cells. Meanwhile, our results also showed that AIF triggered pyroptotic cell death in ESCC, which was mediated by gasdermin E (GSDME) cleavage. In addition, our experiments provided experimental evidence that AIF-induced GSDME cleavage was dependent on caspase-3 activation. Moreover, the inhibition of GSDSE by knockdown was able to switch the form of cell death from pyroptosis to apoptosis. Furthermore, the results from the xenograft animal model also supported our findings in vitro that AIF was able to promote GSDME-mediated pyroptotic cell death in ESCC. AIF inhibited ESCC growth in vitro and in vivo by triggering GSDME-mediated pyroptotic cell death, which is dependent on caspase-3 activation.

Flavonoids Distinctly Stabilize Lymph Endothelial- or Blood Endothelial Disintegration Induced by Colon Cancer Spheroids SW620

The health effects of plant phenolics in vegetables and other food and the increasing evidence of the preventive potential of flavonoids in “Western Diseases” such as cancer, neurodegenerative diseases and others, have gained enormous interest. This prompted us to investigate the effects of 20 different flavonoids of the groups of flavones, flavonols and flavanones in 3D in vitro systems to determine their ability to inhibit the formation of circular chemorepellent induced defects (CCIDs) in monolayers of lymph- or blood-endothelial cells (LECs, BECs; respectively) by 12(S)-HETE, which is secreted by SW620 colon cancer spheroids. Several compounds reduced the spheroid-induced defects of the endothelial barriers. In the SW620/LEC model, apigenin and luteolin were most active and acacetin, nepetin, wogonin, pinocembrin, chrysin and hispidulin showed weak effects. In the SW620/BEC model acacetin, apigenin, luteolin, wogonin, hispidulin and chrysin exhibited weak activity.

A Combination of Rosa Canina Extracts and Gold Complex Favors Apoptosis of Caco-2 Cells by Increasing Oxidative Stress and Mitochondrial Dysfunction

Given the alarming increase in colorectal cancer (CRC) worldwide, novel therapies are urgently needed. Plant-derived extracts have gained considerable interest in the last years due to their strong anticancer effect mediated by their unique bioactive compounds. Specifically, rosehips from Rosa canina have been successfully tested against several cancer models, including colon cancer. Moreover, gold derivatives are a promising alternative to the current platinum-based drugs commonly used in CRC chemotherapy due to their lack of affinity for DNA. Herein we have investigated the antitumor potential of a drug combination made of acidic polyphenols extracted from R. canina and the gold complex (Au(C≡C-2-NC₅H₄) (PTA)) in Caco-2 cell line as a model of CRC. The combination triggered strong apoptosis mediated by a blockage of the autophagic flux, which might be a consequence of a reactive oxygen species (ROS) increase and mitochondrial dysfunctionality. Our results suggest that the clinical application of plant polyphenols might enhance the anticancer effect of metallodrugs and reduce drug exposure time and therefore its side effects.

Structural Insight into the In Vitro Anti-Intravasative Properties of Flavonoids

We investigated the effect of 21 flavonoids in a three-dimensional in vitro system for their ability to inhibit gap formation by MCF-7 breast cancer spheroids in monolayers of lymphendothelial cells. Different representatives of the classes of flavones, flavonols, and flavanones were tested in the circular chemorepellent-induced defects (CCID)-assay. Bay11-7082, a known inhibitor of CCID formation served as the positive control. This study provides the first comparison of the potential of flavonoids to suppress features influencing the intravasation of MCF-7 breast cancer cells aggregates through the lymph endothelial barrier. The most significant effects were seen after incubation with the flavones luteolin, chrysin, and apigenin. Additional hydroxylation or methoxylation in positions 6 or 8, as expected, resulted in decreased activity. The tested flavanones remained without or low efficacy.

Antimetastatic Properties of Tea Polyphenols

Metastasis of cells from primary site to distant organs involves a series of sequential steps, and molecules responsible for all these events are understandably considered as potential targets for metastasis management. Tea polyphenols, the secondary metabolites of the tea leaf Camellia sinensis, are increasingly being studied for their antimetastatic properties. In this article, effects of green tea polyphenols (GTP) and black tea polyphenols (BTP) on the molecules and events involved in metastasis are discussed in detail. As tea is a very popular beverage, tea polyphenols are expected to be potential chemopreventive agents that can be taken with normal diet and can be nontoxic due to their natural origin. However, individual variations in metabolic pathways, bioavailability, dose, and toxicity are some important factors that can modify the effectiveness of tea polyphenols within the human system.

Poly(lactic-co-glycolic acid) Nanoparticles Loaded with Callistemon citrinus Phenolics Exhibited Anticancer Properties against Three Breast Cancer Cell Lines

Fruit and vegetable diets rich in phenolic compounds reduce the risk of various cancers and offer multiple other health benefits due to their bioactivity and powerful antioxidant properties. However, the human health benefits of most phenolic compounds are restricted due to their limited aqueous solubility, low absorption, restricted passive cellular efflux, and poor gastrointestinal stability. Nanotechnology has been used to deliver various therapeutic drugs to specific targets overcoming many of the limitations of direct treatments. This study was designed to develop poly(lactic-co-glycolic acid) (PLGA) nanoencapsulated phenolic-rich extracts from Callistemon citrinus and berberine and to evaluate their effectiveness against extremely invasive MDA-MB 231, moderately invasive MCF-10A, and minimally invasive MCF-7 breast cancers. We have achieved about 80% encapsulation of phenolics from C. citrinus. Most encapsulated nanoparticles were polygonal with particles sizes of 200 to 250 nm. Release of phenolics from encapsulation during storage was biphasic during the first week and then levelled off thereafter. Nanoencapsulated phenolics from C. citrinus extract, berberine, and combination of both enhanced their bioactivity against the three breast cancer cell lines by nearly 2-fold. Growth inhibition of cells was a linear curve relative to phenolic concentration, with a maximum inhibition of nearly 100% at 0.1 mg/ml compared to control.

Strobilanthes crispus inhibits migration, invasion and metastasis in breast cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Strobilanthes crispus (L.) Blume, locally known in Malaysia as "Pecah kaca" or "Jin batu", has been traditionally used for treatment of various ailments including cancer. We previously demonstrated that a standardized bioactive subfraction of S. crispus, termed as F3, possessed potent anticancer effects in both in vitro and in vivo breast cancer models.

AIM OF THE STUDY

To investigate the potential of F3 from S. crispus to prevent metastasis in breast cancer.

MATERIALS AND METHODS

The antimetastatic effects of F3 were first investigated on murine 4T1 and human MDA-MB-231 breast cancer cell (BCC) lines using cell proliferation, wound healing and invasion assays. A 4T1-induced mouse mammary carcinoma model was then used to determine the expression of metastasis tumor markers, epithelial (E)-cadherin, matrix metalloproteinase (MMP)-9, mucin (MUC)-1, nonepithelial (N)-cadherin, Twist, vascular endothelial growth factor (VEGF) and vimentin, using immunohistochemistry, following oral treatment with F3 for 30 days.

RESULTS

Significant growth arrest was observed with F3 IC₅₀ values of 84.27 µg/ml (24 h) and 74.41 µg/ml (48 h) for MDA-MB-231, and 87.35 µg/ml (24 h) and 78.75 µg/ml (48 h) for 4T1 cells. F3 significantly inhibited migration of both BCC lines at 50 μg/ml for 24 h (p = 0.018 and p = 0.015, respectively). Similarly, significant inhibition of invasion was demonstrated in 4T1 (75 µg/ml, p = 0.016) and MDA-MB-231 (50 µg/ml, p = 0.040) cells compared to the untreated cultures. F3 treatment resulted in reduced tumor growth compared to untreated mice (p < 0.01) or mice treated with tamoxifen (p < 0.05). Statistical parameters (absolute count, proportion, intensity and overall scores) indicating upregulation of E-cadherin expression were statistically significant in F3-treated compared to the untreated tumor-bearing mice. Similarly, F3 significantly reduced the expression of MMP-9, MUC1, N-cadherin, Twist, VEGF and vimentin in comparison with the TM (p < 0.01) group CONCLUSIONS: Our findings suggest that F3 exerts anti-metastatic effects independent of its cytotoxic effects, and these are supported by the increased expression of E-cadherin concurrent with downregulation of MMP-9, MUC1, N-cadherin, Twist, VEGF and vimentin expression in breast cancer.

Elevated expression of Gab1 promotes breast cancer metastasis by dissociating the PAR complex

BACKGROUND

Breast cancer (BCa) remains as the second leading cause of cancer-related death in women worldwide. The majority of the deaths are due to its progression to metastatic BCa. Although Grb2-associated binding protein 1 (Gab1) has been implicated in tumor proliferation and metastasis in multiple tumors including colorectal cancer, hepatocellular carcinoma and ovarian cancer, whether and how it regulates BCa metastasis are still poorly understood.

METHODS

Western blot assay and immunohistochemical (IHC) staining were performed to assess expression of Gab1 in primary and metastatic BCa clinical samples. Biological function assay studies in vitro and in vivo were employed to investigate the functions of Gab1 during BCa metastasis. Co-immunoprecipitation (co-IP) assessment, western blot assay and immunofluorescence (IF) staining were carried out to investigate the underlying mechanism for the function of Gab1 on BCa metastasis.

RESULTS

In this study, we found that expression level of Gab1 was increased significantly in BCa tissue samples compared to that in benign mammary hyperplastic tissues. Furthermore, elevated expression of Gab1 was positively associated with metastasis in HER2 and TNBC subtypes of BCa. In BCa cell line MDA-MB-231 and SK-BR3 cells, stable overexpression of Gab1 promoted, while knockdown of Gab1 inhibited cell migration in vitro and metastasis in vivo. Mechanistically, overexpression of Gab1 enhanced its interaction with Par3, a key component of the polarity-associated partitioning defective (PAR) complex, leading to a dissociation of the PAR complex. Consequently, dissociated PAR complex induced epithelial-to-mesenchymal transition (EMT) for breast tumor metastasis. By restoration assessment, we found that only re-expression of a fully functional Gab1, but not a mutant Gab1 that harbors either Par3 binding-deficiency or Par1b binding-deficiency, could reverse the repressive phenotype of cell migration in vitro and metastasis in vivo due to Gab1 knockdown.

CONCLUSIONS

Our findings indicate that elevated expression of Gab1 promotes BCa metastasis by dissociating the PAR complex that leads to EMT, implicating a role of Gab1 as a potential biomarker of metastatic BCa. Moreover, inhibition of Gab1 expression might be a promising therapeutic strategy for BCa metastasis.

Cardiovascular Effects of Flavonoids

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Cardiovascular Disease (CVD) is the major cause of death worldwide, especially in Western society. Flavonoids are a large group of polyphenolic compounds widely distributed in plants, present in a considerable amount in fruit and vegetable. Several epidemiological studies found an inverse association between flavonoids intake and mortality by CVD. The antioxidant effect of flavonoids was considered the main mechanism of action of flavonoids and other polyphenols. In recent years, the role of modulation of signaling pathways by direct interaction of flavonoids with multiple protein targets, namely kinases, has been increasingly recognized and involved in their cardiovascular protective effect. There are strong evidence, in in vitro and animal experimental models, that some flavonoids induce vasodilator effects, improve endothelial dysfunction and insulin resistance, exert platelet antiaggregant and atheroprotective effects, and reduce blood pressure. Despite interacting with multiple targets, flavonoids are surprisingly safe. This article reviews the recent evidence about cardiovascular effects that support a beneficial role of flavonoids on CVD and the potential molecular targets involved.

Leukemia therapy by flavonoids: Future and involved mechanisms

Flavonoids are a varied family of phytonutrients (plant chemicals) usually are detected in fruits and vegetables. In this big family, there exist more than 10,000 members that is separated into six chief subtypes: isoflavonols, flavonoenes, flavones, flavonols, anthocyanins, and chalcones. The natural compounds, such as fruits, have visible positive effects in regulating of survival involved signaling pathways that performance as the regulator of cell survival, growth, and proliferation. Researchers have established that commonly consumption up flavonoids decreases incidence and development risk of certain cancers, especially leukemia. Flavonoids have been able to induce apoptosis and stimulate cell cycle arrest in cancer cells via different pathways. Similarly, they have antiangiogenesis and antimetastasis capability, which were shown in wide ranges of cancer cells, particularly, leukemia. It seems that flavonoid because of their widespread approval, evident safety and low rate of side effects, have hopeful anticarcinogenic potential for leukemia therapy. Based on the last decade reports, the most important acting mechanisms of these natural compounds in leukemia cells are stimulating of apoptosis pathways by upregulation of caspase 3, 8, 9 and poly ADP-ribose polymerase (PARP) and proapoptotic proteins, particularly Bax activation. As well, they can induce cell cycle arrest in target cells not only via increasing of activated levels of p21 and p53 but also by inhibition of cyclins and cyclin-dependent kinases. Furthermore, attenuation of neclear factor-κB and signal transducer and activator of transcription 3 activation, suppression of signaling pathway and downregulation of intracellular antiapoptotic proteins are other significant antileukemic function mechanism of flavonoids. Overall, it appears that flavonoids are promising and effective compounds in the field of leukemia therapy. In this review, we tried to accumulate and revise most promising flavonoids and finally declared their major working mechanisms in leukemia cells.

Bcl-2 promotes metastasis through the epithelial-to-mesenchymal transition in the BCap37 medullary breast cancer cell line

Metastatic breast cancer is one of the major types of cancer in women. However, despite being the focus of considerable research efforts, its molecular mechanism remains to be fully elucidated. The B-cell lymphoma/leukemia gene-2 (Bcl-2) protein is well known for its role in inhibiting programmed cell death/apoptosis. However, little is known concerning its function in cell invasion and migration. In the present study, cell migration and invasion assays revealed that anti-apoptotic Bcl-2 protein induced migration and invasion without affecting cell proliferation in the BCap37 breast cancer cell line. In addition, it was found that the overexpression of Bcl-2 in BCap37 cells increased metastasis to the lung in a mouse model. Using western blotting and RT q-PCR analysis, it was demonstrated that the overexpression of Bcl-2 inhibited the expression of E-cadherin, an epithelial marker, whereas it increased the levels of mesenchymal markers N-cadherin and vimentin. Therefore, the results suggested that Bcl-2 may induce cellular metastasis in breast cancer via the epithelial-to-mesenchymal transition.

Transketolase Regulates the Metabolic Switch to Control Breast Cancer Cell Metastasis via the α-Ketoglutarate Signaling Pathway

Although metabolic reprogramming is recognized as a hallmark of tumorigenesis and progression, little is known about metabolic enzymes and oncometabolites that regulate breast cancer metastasis, and very few metabolic molecules have been identified as potential therapeutic targets. In this study, the transketolase (TKT) expression correlated with tumor size in the 4T1/BALB/c syngeneic model. In addition, TKT expression was higher in lymph node metastases compared with primary tumor or normal tissues of patients, and high TKT levels were associated with poor survival. Depletion of TKT or addition of alpha-ketoglutarate (αKG) enhanced the levels of tumor suppressors succinate dehydrogenase and fumarate hydratase (FH), decreasing oncometabolites succinate and fumarate, and further stabilizing HIF prolyl hydroxylase 2 (PHD2) and decreasing HIF1α, ultimately suppressing breast cancer metastasis. Reduced TKT or addition of αKG mediated a dynamic switch of glucose metabolism from glycolysis to oxidative phosphorylation. Various combinations of the TKT inhibitor oxythiamine, docetaxel, and doxorubicin enhanced cell death in triple-negative breast cancer (TNBC) cells. Furthermore, oxythiamine treatment led to increased levels of αKG in TNBC cells. Together, our study has identified a novel TKT-mediated αKG signaling pathway that regulates breast cancer oncogenesis and can be exploited as a modality for improving therapy.Significance: These findings uncover the clinical significance of TKT in breast cancer progression and metastasis and demonstrate effective therapy by inhibiting TKT or by adding αKG. Cancer Res; 78(11); 2799-812. ©2018 AACR.

Plant-Derived Anticancer Agents: Lessons from the Pharmacology of Geniposide and Its Aglycone, Genipin

For centuries, plants have been exploited by mankind as sources of numerous cancer chemotherapeutic agents. Good examples of anticancer compounds of clinical significance today include the taxanes (e.g., taxol), vincristine, vinblastine, and the podophyllotoxin analogues that all trace their origin to higher plants. While all these drugs, along with the various other available therapeutic options, brought some relief in cancer management, a real breakthrough or cure has not yet been achieved. This critical review is a reflection on the lessons learnt from decades of research on the iridoid glycoside geniposide and its aglycone, genipin, which are currently used as gold standard reference compounds in cancer studies. Their effects on tumour development (carcinogenesis), cancer cell survival, and death, with particular emphasis on their mechanisms of actions, are discussed. Particular attention is also given to mechanisms related to the dual pro-oxidant and antioxidant effects of these compounds, the mitochondrial mechanism of cancer cell killing through reactive oxygen species (ROS), including that generated through the uncoupling protein-2 (UCP-2), the inflammatory mechanism, and cell cycle regulation. The implications of various studies for the evaluation of glycosidic and aglycone forms of natural products in vitro and in vivo through pharmacokinetic scrutiny are also addressed.

Myricetin suppresses breast cancer metastasis through down-regulating the activity of matrix metalloproteinase (MMP)-2/9

Tumour metastasis is the major cause of breast cancer mortality. Myricetin, a natural polyphenol, is found in teas, wines, and berries. The pharmacodynamic action and molecular mechanism of myricetin on breast cancer metastasis remain unknown. Here, we investigated the effect of myricetin on MDA-Mb-231Br cell viability, migration, invasion, and 4T1 mouse lung metastasis mouse models. MMP-2/9 protein expression and ST6GALNAC5 expression were analysed using western blot assays and quantitative real-time polymerase chain reaction, respectively. Cell migration and invasion were detected by wound-healing and Boyden transwell assays. The antimetastatic effect in vivo was evaluated by lung metastasis model. Myricetin significantly decreased the activities of MMP-2/9 and mRNA levels of ST6GALNAC5. In addition, the migration, invasion, and adhesion were effectively inhibited in a concentration-dependent manner. On the other hand, mice treated with myricetin exhibited smaller tumour nodules compared with the vehicle mice, with only 17.78 ± 15.41% after treatment with 50 mg/kg myricetin. In conclusion, myricetin could significantly block invasion of MDA-Mb-231Br cells through suppressing the protein expression of MMP-2/9 and the expression of ST6GALNAC5, as well as lung metastasis in a mouse model, which suggests that myricetin should be developed as a potential therapeutic candidate for breast cancer.

Ginsenoside 20(S)-Rh2 exerts anti-cancer activity through the Akt/GSK3β signaling pathway in human cervical cancer cells

Ginsenoside 20(S)-Rh2 (GRh2) is a bioactive compound derived from ginseng that is believed to maintain health in traditional Chinese medicine. Emerging evidence has suggested that GRh2 exhibits anti‑cancer activity. The present study hypothesized that GRh2 has an anti‑cancer function in human cervical cancer cells. An MTS assay demonstrated that GRh2 attenuated proliferation of HeLa cells in a dose‑ and time‑dependent manner. In addition, GRh2 inhibited migration and invasion, as determined by wound healing and transwell invasion assays, respectively. Furthermore, GRh2 treatment reduced expression of mesenchymal markers N‑cadherin and vimentin as well as epithelial mesenchymal transition transcriptional factor zinc finger E‑box‑binding homeobox 1 and snail1, and increased the protein expression levels of epithelial marker E‑cadherin. In addition, the results revealed that GRh2 prevented activation of the protein kinase B (Akt)/glycogen synthase kinase (GSK)3β signaling pathway in HeLa cells. In conclusion, the results suggested that GRh2 inhibits cervical cancer cell proliferation by targeting the Akt pathway, and prevents cervical cancer cell migration and invasion by suppressing the Akt/GSK3β regulated EMT process, and therefore, GRh2 may have the potential to be a novel anti‑cancer agent for cervical cancer.

Breast cancer lung metastasis: Molecular biology and therapeutic implications

Distant metastasis accounts for the vast majority of deaths in patients with cancer. Breast cancer exhibits a distinct metastatic pattern commonly involving bone, liver, lung, and brain. Breast cancer can be divided into different subtypes based on gene expression profiles, and different breast cancer subtypes show preference to distinct organ sites of metastasis. Luminal breast tumors tend to metastasize to bone while basal-like breast cancer (BLBC) displays a lung tropism of metastasis. However, the mechanisms underlying this organ-specific pattern of metastasis still remain to be elucidated. In this review, we will summarize the recent advances regarding the molecular signaling pathways as well as the therapeutic strategies for treating breast cancer lung metastasis.

Polyphenols: dietary assessment and role in the prevention of cancers

PURPOSE OF REVIEW

Polyphenols are a large and diverse family of phytochemicals widely consumed by humans. Here we summarize the latest epidemiological evidence for associations between cancer risk and polyphenol intake, taking into account difficulties in the accurate estimation of exposure.

RECENT FINDINGS

Flavonoids are the most studied subgroup of polyphenols with regard to cancer risk. In recent epidemiological studies, total flavonoid intake has rarely been associated with a reduction in cancer risk. However, isoflavones, whose main dietary source is soy foods, plausibly reduce the risk of colorectal, breast, and prostate cancers, especially in Asian countries. Findings depend heavily upon the assessment of polyphenol intake, which is usually measured by food frequency questionnaires coupled to databases of food polyphenol composition. To a lesser extent, nutritional biomarkers have been used whenever estimating associations of polyphenol intake with cancer.

SUMMARY

Polyphenol intake may mitigate cancer risk but this depends on cancer site, the subgroup of compounds under study, and accurate assessment of dietary exposure. Further work must better characterize the effects of intake of different flavonoid subclasses and begin to investigate the role of phenolic acids and other minor polyphenol classes.

Extracellular matrix protein 1 promotes cell metastasis and glucose metabolism by inducing integrin β4/FAK/SOX2/HIF-1α signaling pathway in gastric cancer

Extracellular matrix protein 1 (ECM1) is related to strong invasiveness and poor prognosis in major malignancies, but the underlying mechanism remains unknown. Here we aimed to elucidate the function of ECM1 on cell metastasis and glucose metabolism in gastric cancer (GC). The level of ECM1 in sera and tissues of patient with GC were positively correlated with tumor invasion and recurrence. Genetic manipulation of ECM1 expression affected cell metastasis and glucose metabolism in GC cell lines. Enhanced ECM1 expression facilitated gene expression levels associated with epithelial-mesenchymal transition (EMT) and glucose metabolism. Interestingly, our results indicated that ECM1 directly interacted with integrin β4 (ITGB4) and activated ITGB4/focal adhesion kinase (FAK)/glycogen synthase kinase 3β signaling pathway, which further induced the expression of transcription factor SOX2. Aberrant expression of SOX2 altered gene expression of EMT factors and glucose metabolism enzymes. Furthermore, SOX2 enhanced hypoxia-inducible factor α (HIF-1α) promoter activity to regulate glucose metabolism. The micro-positron emission tomography/computed tomography imaging of xenograft model showed that ECM1 substantially increased ¹⁸F-fluorodeoxyglucose uptake in xenograft tumors. Using in vivo mouse tail vein injection experiments, ECM1 was also found to increase in lung surface metastasis. These findings provide evidence that ECM1 regulates GC cell metastasis and glucose metabolism by inducing ITGB4/FAK/SOX2/HIF-1α signal pathway and have important implications for the development of therapeutic target to prevent tumor metastasis and recurrence.

miR-137 acts as a tumor suppressor via inhibiting CXCL12 in human glioblastoma

Up to date, miR-137 has been demonstrated as a tumor suppressor in many kinds of human malignancies. In the present study, we conducted transfection, western blot and RT-PCR to explore the role of miR-137 in the development of human glioblastoma (GBM). Here, we found that miR-137 expression was obviously down-regulated in GBM tissues and cells rather than matched non-tumor tissues and NHA cells. However, the expression of C-X-C motif ligand 12 (CXCL12) mRNA and protein were up-regulated in GBM tissues and cells. In vitro, miR-137 mimics inhibited GBM cell proliferation, migration and invasion, and the 3′-untranslated regions (3′-UTR) of CXCL12 were a direct target of miR-137. In addition, miR-137 mimics also inhibited the expression of EGFR, Bcl-2 and MMP2/9 proteins, but increased the expression of Bax protein. Notably, CXCL12 over-expression attenuated miR-137-inhibited cell proliferation and invasion, while CXCL12 siRNAs promoted miR-137 inhibition effects. In vivo, miR-137 mimics also suppressed tumor growth in nude mice xenograft model. In conclusion, miR-137 serves as a tumor suppressor by inhibition of CXCL12 in human GBM. Thus, miR-137-CXCL12 can be recommended as a useful and effective target for treatment of GBM.