Curcumin inhibits cell growth and invasion through up-regulation of miR-7 in pancreatic cancer cells

LncRNA XLOC_006390 facilitates cervical cancer tumorigenesis and metastasis as a ceRNA against miR-331-3p and miR-338-3p

OBJECTIVE

Cervical cancer is one of the most common malignant tumors. Our previous results showed that long non-coding RNA (lncRNA) XLOC_006390 plays an important role in cervical cancer. In this study, we have explored the mechanism of action of lncRNA XLOC_006390.

METHODS

LncRNA XLOC_006390 was proposed to exercise its function as a competing endogenous RNA (ceRNA), and its potential targeted miRNAs was predicted through the database LncBase Predicted v.2. Two miRNAs, miR-331-3p, and miR-338-3p, were chosen for the study. Expression of miRNAs and lncRNA in cervical cancer cells and tissues was detected by reverse transcription polymerase chain reaction. To determine the correlation, silencing of XLOC_006390, over-expression of miR-331-3p, and miR-338-3p was performed in SiHa and Caski cell lines, respectively.

RESULTS

Based on the interactive effect between miRNA and lncRNA, miR-331-3p and miR-338-3p were significantly downregulated in cervical cancer cells and tissues, and their expression levels were negatively related to that of lncRNA. Our results also showed that the expression of miR-331-3p target gene NRP2, miR-338-3p target genes PKM2, EYA2 was significantly downregulated when the XLOC_006390 was knocked down. Further, XLOC_006390 was found to facilitate cervical cancer tumorigenesis and metastasis by downregulating miR-331-3p and miR-338-3p expression.

CONCLUSION

Taken together, our study demonstrated that XLOC_006390 may serve as a ceRNA and reversely regulates the expression of miR-331-3p and miR-338-3p, thus facilitating cervical cancer tumorigenesis and metastasis.

Naturally occurring compounds as pancreatic cancer therapeutics

Naturally occurring small molecule compounds have long been in the spotlight of pancreatic cancer research as potential therapeutics to prevent cancer progression and sensitize chemoresistant tumors. The hope is that terminal pancreatic cancer patients receiving aggressive chemotherapy can benefit from an increase in treatment efficacy without adding further toxicity by way of utilizing natural compounds. While preclinical studies on a number of natural compounds, such as resveratrol, curcumin, rapalogs and cannabinoids, show promising preclinical results, little has translated into clinical practice, though a number of other compounds hold clinical potential. Nevertheless, recent advances in compound formulation may increase the clinical utility of these compounds.

miR-7 Suppresses Tumor Progression by Directly Targeting MAP3K9 in Pancreatic Cancer

Extensive research has suggested that miR-7 plays a critical role in cancer progression. However, the biological function of miR-7 in pancreatic cancer (PC) progression is poorly understood. Therefore, in the present study, we investigated the function of miR-7 and its molecular mechanism in PC progression. We used multiple methods, such as MTT, FACS, Transwell assay, RT-PCR, western blotting, and transfection to investigate the role of miR-7 in PC cells. We found that miR-7 suppressed cell growth, migration, and invasion but induced apoptosis in PC cells. Moreover, overexpression of miR-7 repressed tumor growth in mice, suggesting that miR-7 could exert its tumor-suppressive function in PC. Mechanistically, we validated that MAP3K9 is a direct target of miR-7, which significantly enhanced PC cell proliferation and inhibited cell apoptosis partly through activation of the MEK/ERK pathway and NF-κB pathway. Moreover, rescue experiments also showed that miR-7 suppressed PC cell proliferation and induced PC cell apoptosis by directly targeting MAP3K9, leading to inhibition of the MEK/ERK and NF-κB pathways. Taken together, these results suggest that miR-7/MAP3K9 is critically involved in PC progression and that miR-7 may be a potential target for PC treatment.

Advances of circular RNAs in carcinoma

Circular RNAs (circRNAs) are a type of non-coding RNAs with single-stranded closed structure. The rapid development of high-throughput sequencing technology has allowed for the widespread presence of circRNAs in transcriptomes. Moreover, increasing studies have identified a correlation between circRNAs and different cancers. In addition, most circRNAs are dysregulated in various cancers, and some of them have been reported be vital in the occurrence and development of tumors. For example, ciRS-7 plays a role in tumor promotion and circ-ITCH acts as a tumor suppressor. This review summarizes the latest progressions in the field regarding the functions of circRNAs in relation with cancers, and anticipates the emerging roles of circRNAs and future challenges in cancer research.

Characteristics of Curcumin-Loaded Bacterial Cellulose Films and Anticancer Properties against Malignant Melanoma Skin Cancer Cells

Curcumin-loaded bacterial cellulose films were developed in this study. Curcumin was absorbed into never-dried bacterial cellulose pellicles by 24-h immersion in solutions of curcumin in the range of 0.2–1.0 mg /mL. The curcumin-loaded bacterial cellulose pellicles were then air-dried and characterized. The mechanical properties of curcumin-loaded bacterial cellulose films, particularly the stretching properties, appeared to be lower than those of bacterial cellulose film. This was especially evident when the loading concentration of curcumin was higher than 0.4 mg/mL. Fourier-transform infrared spectroscopy analysis indicated an interaction between bacterial cellulose microfibrils and curcumin. Controlled release of curcumin was achieved in buffer solutions containing Tween 80 and methanol additives, at pH 5.5 and 7.4. Curcumin-loaded bacterial cellulose films prepared with curcumin solutions at concentrations of 0.5 and 1.0 mg/mL displayed antifungal activities against Aspergillus niger. They also exhibited anticancer activity against A375 malignant melanoma cells. No significant cytotoxic effect was observed against normal dermal cells, specifically, human keratinocytes and human dermal fibroblasts.

Effects of resveratrol, curcumin, berberine and other nutraceuticals on aging, cancer development, cancer stem cells and microRNAs

Natural products or nutraceuticals have been shown to elicit anti-aging, anti-cancer and other health-enhancing effects. A key target of the effects of natural products may be the regulation of microRNA (miR) expression which results in cell death or prevents aging, diabetes, cardiovascular and other diseases. This review will focus on a few natural products, especially on resveratrol (RES), curcumin (CUR) and berberine (BBR). RES is obtained from the skins of grapes and other fruits and berries. RES may extend human lifespan by activating the sirtuins and SIRT1 molecules. CUR is isolated from the root of turmeric (Curcuma longa). CUR is currently used in the treatment of many disorders, especially in those involving an inflammatory process. CUR and modified derivatives have been shown to have potent anti-cancer effects, especially on cancer stem cells (CSC). BBR is also isolated from various plants (e.g., Coptis chinensis) and has been used for centuries in traditional medicine to treat diseases such as adult- onset diabetes. Understanding the benefits of these and other nutraceuticals may result in approaches to improve human health.

Osthole promotes endogenous neural stem cell proliferation and improved neurological function through Notch signaling pathway in mice acute mechanical brain injury

Mechanical brain injury (MBI) is a common neurotrosis disorder of the central nervous system (CNS), which has a higher mortality and disability. In the case of MBI, neurons death leads to loss of nerve function. To date, there was no satisfactory way to restore neural deficits caused by MBI. Endogenous neural stem cells (NSCs) can proliferate, differentiate and migrate to the lesions after brain injury, to replace and repair the damaged neural cells in the subventricular zone (SVZ), hippocampus and the regions of brain injury. In the present study, we first prepared a mouse model of cortical stab wound brain injury. Using the immunohistochemical and hematoxylin-eosin (H&E) staining method, we demonstrated that osthole (Ost), a natural coumarin derivative, was capable of promoting the proliferation of endogenous NSCs and improving neuronal restoration. Then, using the Morris water maze (MWM) test, we revealed that Ost significantly improved the learning and memory function in the MBI mice, increased the number of neurons in the regions of brain injury, hippocampus DG and CA3 regions. Additionally, we found that Ost up-regulated the expression of self-renewal genes Notch 1 and Hes 1. However, when Notch activity was blocked by the γ-secretase inhibitor DAPT, the expression of Notch 1 and Hes 1 mRNA was down-regulated, augmentation of NICD and Hes 1 protein was ameliorated, the proliferation-inducing effect of Ost was abolished. These results suggested that the effects of Ost were at least in part mediated by activation of Notch signaling pathway. Our findings support that Ost is a potential drug for treating MBI due to its neuronal restoration.

DNA Methylation of miR-7 is a Mechanism Involved in Platinum Response through MAFG Overexpression in Cancer Cells

One of the major limitations associated with platinum use is the resistance that almost invariably develops in different tumor types. In the current study, we sought to identify epigenetically regulated microRNAs as novel biomarkers of platinum resistance in lung and ovarian cancers, the ones with highest ratios of associated chemo-resistance.

Methods: We combined transcriptomic data from microRNA and mRNA under the influence of an epigenetic reactivation treatment in a panel of four paired cisplatin -sensitive and -resistant cell lines, followed by real-time expression and epigenetic validations for accurate candidate selection in 19 human cancer cell lines. To identify specific candidate genes under miRNA regulation, we assembled “in silico” miRNAs and mRNAs sequences by using ten different algorithms followed by qRT-PCR validation. Functional assays of site-directed mutagenesis and luciferase activity, miRNAs precursor overexpression, silencing by antago-miR and cell viability were performed to confirm their specificity in gene regulation. Results were further explored in 187 primary samples obtained from ovarian tumors and controls.

Results: We identified 4 candidates, miR-7, miR-132, miR-335 and miR-148a, which deregulation seems to be a common event in the development of resistance to cisplatin in both tumor types. miR-7 presented specific methylation in resistant cell lines, and was associated with poorer prognosis in ovarian cancer patients. Our experimental results strongly support the direct regulation of MAFG through miR-7 and their involvement in the development of CDDP resistance in human tumor cells.

Conclusion: The basal methylation status of miR-7 before treatment may be a potential clinical epigenetic biomarker, predictor of the chemotherapy outcome to CDDP in ovarian cancer patients. To the best of our knowledge, this is the first report linking the regulation of MAFG by miRNA-7 and its role in chemotherapy response to CDDP. Furthermore, this data highlights the possible role of MAFG as a novel therapeutic target for platinum resistant tumors.

Metformin incombination with curcumin inhibits the growth, metastasis, and angiogenesis of hepatocellular carcinoma in vitro and in vivo

Hepatocellular carcinoma (HCC) has poor prognosis due to the advanced disease stages by the time it is diagnosed, high recurrence rates and metastasis. In the present study, we investigated the effects of metformin (a safe anti-diabetic drug) and curcumin (a turmeric polyphenol extracted from rhizome of Curcuma longa Linn.) on proliferation, apoptosis, invasion, metastasis, and angiogenesis of HCC in vitro and in vivo. It was found that co-treatment of metformin and curcumin could not only induce tumor cells into apoptosis through activating the mitochondria pathways, but also suppress the invasion, metastasis of HCC cells and angiogenesis of HUVECs. These effects were associated with downregulation of the expression of MMP2/9, VEGF, and VEGFR-2, up-regulation of PTEN, P53 and suppression of PI3K/Akt/mTOR/NF-κB and EGFR/STAT3 signaling. Co-administration of metformin and curcumin significantly inhibited HCC tumor growth than administration with metformin or curcumin alone in a xenograft mouse model. Thus, metformin and curcumin in combination showed a better anti-tumor effects in hepatoma cells than either metformin or curcumin presence alone and might represent an effective therapeutic strategy for HCC treatment.

Curcumin Induces Autophagy, Apoptosis, and Cell Cycle Arrest in Human Pancreatic Cancer Cells

Objective

Curcumin is an active extract from turmeric. The aim of this study was to identify the underlying mechanism of curcumin on PCa cells and the role of autophagy in this process.

Methods

The inhibitory effect of curcumin on the growth of PANC1 and BxPC3 cell lines was detected by CCK-8 assay. Cell cycle distribution and apoptosis were tested by flow cytometry. Autophagosomes were tested by cell immunofluorescence assay. The protein expression was detected by Western blot. The correlation between LC3II/Bax and cell viability was analyzed.

Results

Curcumin inhibited the cell proliferation in a dose- and time-dependent manner. Curcumin could induce cell cycle arrest at G2/M phase and apoptosis of PCa cells. The autophagosomes were detected in the dosing groups. Protein expression of Bax and LC3II was upregulated, while Bcl2 was downregulated in the high dosing groups of curcumin. There was a significant negative correlation between LC3II/Bax and cell viability.

Conclusions

Autophagy could be triggered by curcumin in the treatment of PCa. Apoptosis and cell cycle arrest also participated in this process. These findings imply that curcumin is a multitargeted agent for PCa cells. In addition, autophagic cell death may predominate in the high concentration groups of curcumin.

Cucurmin, anticancer, & antitumor perspectives: A comprehensive review

Cucurmin, a naturally yellow component isolated from turmeric, ability to prevent various life-style related disorders. The current review article mainly emphasizes on different anticancer perspectives of cucurmin, i.e., colon, cervical, uterine, ovarian, prostate head and neck, breast, pulmonary, stomach and gastric, pancreatic, bladder oral, oesophageal, and bone cancer. It holds a mixture of strong bioactive molecule known as cucurminoids that has ability to reduce cancer/tumor at initial, promotion and progression stages of tumor development. In particular, these compounds block several enzymes required for the growth of tumors and may therefore involve in tumor treatments. Moreover, it modulates an array of cellular progressions, i.e., nitric oxide synthetase activity, protein kinase C activity, epidermal growth factor (EGF) receptor intrinsic kinase activity, nuclear factor kappa (NF-kB) activity, inhibiting lipid peroxidation and production of reactive oxygen species. However, current manuscript summarizes most of the recent investigations of cucurmin but still further research should be conducted to explore the role of curcumin to mitigate various cancers.

Regulation of microRNA using promising dietary phytochemicals: Possible preventive and treatment option of malignant mesothelioma

Malignant mesothelioma (MM) is a very aggressive, lethal cancer, and its incidence is increasing worldwide. Development of multi-drug resistance, therapy related side-effects, and disease recurrence after therapy are the major problems for the successful treatment of MM. Emerging evidence indicates that dietary phytochemicals can exert anti-cancer activities by regulating microRNA expression. Until now, only one dietary phytochemical (ursolic acid) has been reported to have MM microRNA regulatory ability. A large number of dietary phytochemicals still remain to be tested. In this paper, we have introduced some dietary phytochemicals (curcumin, epigallocatechin gallate, quercetin, genistein, pterostilbene, resveratrol, capsaicin, ellagic acid, benzyl isothiocyanate, phenethyl isothiocyanate, sulforaphane, indole-3-carbinol, 3,3'-diindolylmethane, diallyl disulphide, betulinic acid, and oleanolic acid) which have shown microRNA regulatory activities in various cancers and could regulate MM microRNAs. In addition to microRNA regulatory activities, curcumin, epigallocatechin gallate, quercetin, genistein, resveratrol, phenethyl isothiocyanate, and sulforaphane have anti-mesothelioma potentials, and pterostilbene, capsaicin, ellagic acid, benzyl isothiocyanate, indole-3-carbinol, 3,3'-diindolylmethane, diallyl disulphide, betulinic acid, and oleanolic acid have potentials to inhibit cancer by regulating the expression of various genes which are also known to be aberrant in MM.

MicroRNA‑7‑5p regulates the expression of TFF3 in inflammatory bowel disease

Trefoil factor 3 (TFF3) serves an important role in intestinal mucosal damage and healing, and contributes to the pathogenesis and treatment of inflammatory bowel disease (IBD). The aim of the present study was to determine the association between TFF3 and microRNA‑7‑5p (miR‑7‑5p) in IBD. Tissue immunohistochemistry was applied to evaluate the relative expression of TFF3, and reverse transcription‑quantitative polymerase chain reaction was performed to determine the expression of miR‑7‑5p in lesional tissue obtained from patients with IBD and healthy control tissues. A dual‑luciferase reporter assay was used to investigate whether TFF3 was a target of miR‑7‑5p, and western blotting was performed to determine the expression of TFF3 when miR‑7‑5p was overexpressed or suppressed. The protein expression levels of TFF3 were decreased and miR‑7‑5p was overexpressed in the lesional tissue of patients with IBD compared with in healthy control tissues. TFF3 was identified as a target of miR‑7‑5p, and TFF3 protein expression was negatively regulated by miR‑7‑5p in human colonic epithelial LS174T cells. The present study demonstrated a negative association between the expression of miR‑7‑5p and TFF3 in IBD lesional tissues and normal tissues. In conclusion, TFF3 was identified as a novel target of miR‑7‑5p and miR‑7‑5p may serve as a promising therapeutic target for IBD.

Peptide grafted and self-assembled poly(γ-glutamic acid)-phenylalanine nanoparticles targeting camptothecin to glioma

Aim: To synthesize cRGDfK peptide conjugated poly(γ-glutamic acid)-phenylalanine nanoparticles to improve the therapeutic efficacy of camptothecin (CPT) against glioblastoma multiforme. Methods: Peptide-conjugated, drug-loaded nanoparticles (cRGDfK-conjugated camptothecin-loaded PGA–PA nanoparticles [RCPN]) were prepared and physico-chemically characterized using different techniques. Nanoparticles were evaluated for in vitro anticancer activity, cellular uptake, induction of apoptosis and wound healing cell migration against U87MG human glioblastoma cells. Results: RCPN, with a particle size of <100 nm and 65% CPT encapsulation efficiency, exhibited a dose- and time-dependent cytotoxicity to glioblastoma cells. Compared with native CPT or unconjugated nanoparticles, RCPN induced apoptosis, increased reactive oxygen species generation and inhibited U87MG cell migration. Conclusion: cRGDfK-mediated and amphiphilic copolymer-based nanomedicines represent a new approach for improved delivery of anticancer drugs to and treatment of glioblastoma multiforme.

Osthole Stimulated Neural Stem Cells Differentiation into Neurons in an Alzheimer's Disease Cell Model via Upregulation of MicroRNA-9 and Rescued the Functional Impairment of Hippocampal Neurons in APP/PS1 Transgenic Mice

Alzheimer's disease (AD) is the most serious neurodegenerative disease worldwide and is characterized by progressive cognitive impairment and multiple neurological changes, including neuronal loss in the brain. However, there are no available drugs to delay or cure this disease. Consequently, neuronal replacement therapy may be a strategy to treat AD. Osthole (Ost), a natural coumarin derivative, crosses the blood-brain barrier and exerts strong neuroprotective effects against AD in vitro and in vivo. Recently, microRNAs (miRNAs) have demonstrated a crucial role in pathological processes of AD, implying that targeting miRNAs could be a therapeutic approach to AD. In the present study, we investigated whether Ost could enhance cell viability and prevent cell death in amyloid precursor protein (APP)-expressing neural stem cells (NSCs) as well as promote APP-expressing NSCs differentiation into more neurons by upregulating microRNA (miR)-9 and inhibiting the Notch signaling pathway in vitro. In addition, Ost treatment in APP/PS1 double transgenic (Tg) mice markedly restored cognitive functions, reduced Aβ plague production and rescued functional impairment of hippocampal neurons. The results of the present study provides evidence of the neurogenesis effects and neurobiological mechanisms of Ost against AD, suggesting that Ost is a promising drug for treatment of AD or other neurodegenerative diseases.

Curcumin induces apoptotic cell death in human pancreatic cancer cells via the miR-340/XIAP signaling pathway

The natural compound curcumin has previously been reported to inhibit pancreatic cancer cell growth. However, the underlying molecular mechanisms underlying this effect remain unclear. Results from the present study demonstrate that the miR-340/X-linked inhibitor of apoptosis (XIAP) signaling pathway mediates curcumin-induced pancreatic cancer cell apoptosis. miR-340 was identified to be significantly upregulated following curcumin treatment. In addition, treatment with curcumin or miR-340 induced pancreatic cancer cell apoptosis, whereas silencing endogenous miR-340 significantly inhibited the proapoptotic effect of curcumin. A luciferase reporter assay and western blot analysis identified that the oncogene XIAP is a direct target of miR-340. Furthermore, curcumin treatment significantly reduced XIAP expression, an effect that was rescued by treatment with anti-miR-340. The results of the present study suggest that the miR-340/XIAP signaling pathway is a downstream target of curcumin that mediates its proapoptotic effects on pancreatic cancer cells. This may provide the basis for novel treatment strategies for patients with pancreatic cancer.

Circular RNA participates in the carcinogenesis and the malignant behavior of cancer

Circular RNAs (circRNAs) are long, non-coding RNAs that result from the non-canonical splicing of linear pre-mRNAs. However, the characteristics and the critical role of circRNA in co-/post-transcriptional regulation were not well recognized until the "microRNA sponge" function of circRNA is discovered. Recent studies have mainly been devoted to the function of the circular RNA sponge for miR-7 (ciRS-7) and sex-determining region Y (SRY) by targeting microRNA-7 (miR-7) and microRNA-138 (miR-138), respectively. In this review, we illustrate the specific role of circRNAs in a wide variety of cancers and in regulating the biological behavior of cancers via miR-7 or miR-138 regulation. Furthermore, circRNA, together with its gene silencing ability, also shows its potential in RNA interference (RNAi) therapy by binding to target RNAs, which provides a novel perspective in cancer treatment. Thus, this review concerns the biogenesis, biological function, oncogenesis, progression and possible therapies for cancer involving circRNAs.

MicroRNA-7 functions as a tumor-suppressor gene by regulating ILF2 in pancreatic carcinoma

Interleukin enhancer binding factor 2 (ILF2) has been found to be markedly upregulated in pancreatic carcinoma and is involved in the pathogenesis of pancreatic carcinoma. Thus, ILF2 may be a potential target for therapy. Yet, the regulatory mechanisms of ILF2 in pancreatic carcinoma remain largely elusive. In the present study, we demonstrated that ILF2 functioned as an oncogene and regulated epithelial-mesenchymal transition (EMT)-associated genes in pancreatic carcinoma PANC-1 cells. MicroRNA-7 (miR-7) suppressed ILF2 mRNA expression and the protein level in PANC-1 cells. Contrary to ILF2, miRNA-7 functioned as a tumor-suppressor gene and negatively regulated EMT-associated genes in the PANC-1 cells. Curcumin, a polyphenol natural product isolated from the rhizome of the plant Curcuma longa, has emerged as a promising anticancer therapeutic agent. We found that treatment with curcumin increased miR-7 expression and suppressed ILF2 protein in the PANC-1 cells. Thus, we identified ILF2 as a new downstream target gene of curcumin. The results revealed that ILF2 is regulated by miR-7 and suggest that downregulation of miR-7 may be an important factor for the ILF2 overexpression in pancreatic carcinoma.

Up-regulation of miR-21 decreases chemotherapeutic effect of dendrosomal curcumin in breast cancer cells

OBJECTIVES

Despite the good results of anticancer activities by curcumin, there are some hurdles that limit the use of curcumin as an anticancer agent. Many methods were examined to overcome this defect like the use of the dendrosomal curcumin (DNC). There is increasing evidence that miRNAs play important roles in biological processes. In this study, we focus on the roles of microRNA-21 in the anti-cancer effects of DNC in breast cancer.

MATERIALS AND METHODS

Also, we have used different methods such as MTT, apoptosis, cell cycle analysis, transwell migration assay and RT-PCR to find out more.

RESULTS

We observed that miR-21 decreased apoptotic cells in both cells (from 6.35% to 0.34 % and from 7.72% to 1.32% orderly) and DNC increased it. As well as, our findings indicated that cell migration capacity was increased by miR-21 over expression and was decreased by DNC. The combination of miR-21 vector transfection and DNC treatment showed lower percentage of apoptotic cells or a higher level of penetration through the membrane compared with DNC treatment alone. Furthermore, DNC induced a marked increase in the number of cells in sub G1/G1 phase and a decrease in G2/M phase of the cell cycle in both; but, we observed reverse results compared it, after transfection with miR-21 vector.

CONCLUSION

We observed that miR-21 suppress many aspects of anti-cancer effects of DNC in breast cancer cells, it seems that co-treatment with DNC and mir-21 down-regulation may provide a clinically useful tool for drug-resistance breast cancer cells.

Breviscapine suppresses the growth of non-small cell lung cancer by enhancing microRNA-7 expression

Breviscapine (BVP) has previously been shown to inhibit the proliferation of hepatocellular carcinoma cells. However, little is known about the effects of BVP on non-small cell lung cancer (NSCLC) growth. Here, we aimed to study the effects of BVP on human NSCLC growth. We employed A549, NCL-H460 and A549 cells transfected with microRNA-7 (miR-7) mimic and inhibitor to investigate the effect of BVP on cell proliferation, apoptosis and apoptosis-associated molecules. The results showed that BVP significantly reduced the growth of A549 and NCLH460 cells in a concentration-dependent and time-dependent manner, accompanied by a significant elevation of apoptosis. Additionally, the present study also confirmed that BVP-treated A549 cells showed increased levels of Bax and microRNA-7 (miR-7) and a decreased level of Bcl-2. The up-regulation of miR-7 enhanced the BVP sensitivity of NSCLC cells by suppressing cell proliferation and promoting cell apoptosis, while the inhibition of miR-7 reversed the anti-proliferative pro-apoptotic effects of BVP. Pre-treatment with miR-7 mimics enhanced the BVP-mediated down-regulation of Bax/Bcl-2 in NSCLC cells, while pre-treatment with the miR-7 inhibitor blocked the BVPmediated down-regulation of Bax/Bcl. Taken together, these results confirm that BVP effectively inhibits NSCLC proliferation and that miR-7, as a novel target, is likely involved in BVP-induced growth suppression and the apoptosis of NSCLC cells.

Targeting microRNAs: a new action mechanism of natural compounds

Unlike genetics, epigenetics involves the modification of genome without changes in DNA sequences, including DNA methylation, histone modification, chromatin remodeling and noncoding RNA regulation. MicroRNA (miRNA), a member of noncoding RNAs superfamily, participates in RNA interference through a unique mechanism. Currently, microRNAs have been found to be regulated by some natural compounds. Through altering the expression of miRNAs and influencing the downstream signaling pathways or target genes, several natural compounds exhibit its bioactivity in the prevention, diagnosis, therapy, prognosis and drug resistance of human diseases, such as cancer. In this review, several natural compounds and their studies about miRNA-related action mechanism were summarized. These studies provide a new insight into action mechanism by which natural compound exerts its bioactivity and a novel treatment strategy, demonstrating natural compound a promising remedy for clinical treatments.

Curcumin inhibits cancer progression through regulating expression of microRNAs

Curcumin, a major yellow pigment and spice in turmeric and curry, is a powerful anti-cancer agent. The anti-tumor activities of curcumin include inhibition of tumor proliferation, angiogenesis, invasion and metastasis, induction of tumor apoptosis, increase of chemotherapy sensitivity, and regulation of cell cycle and cancer stem cell, indicating that curcumin maybe a strong therapeutic potential through modulating various cancer progression. It has been reported that microRNAs as small noncoding RNA molecules are related to cancer progression, which can be regulated by curcumin. Dysregulated microRNAs play vital roles in tumor biology via regulating expressions of target genes and then influencing multiple cancer-related signaling pathways. In this review, we focused on the inhibition effect of curcumin on various cancer progression by regulating expression of multiple microRNAs. Curcumin-induced dysregulation of microRNAs may activate or inactivate a set of signaling pathways, such as Akt, Bcl-2, PTEN, p53, Notch, and Erbb signaling pathways. A better understanding of the relation between curcumin and microRNAs may provide a potential therapeutic target for various cancers.

EF24 Suppresses Invasion and Migration of Hepatocellular Carcinoma Cells In Vitro via Inhibiting the Phosphorylation of Src

Diphenyl difluoroketone (EF24), a curcumin analog, is a promising anticancer compound that exerts its effects by inhibiting cell proliferation and inducing apoptosis. However, the efficacy of EF24 against cancer metastasis, particularly in hepatocellular carcinoma (HCC), remains elusive. In this study, the effect of EF24 on HCCLM-3 and HepG2 cell migration and invasion was detected by wound healing and transwell assay, respectively. The results revealed that EF24 suppressed the migration and invasion of both HCCLM-3 and HepG2 cells. Furthermore, EF24 treatment decreased the formation of filopodia on the cell surface and inhibited the phosphorylation of Src in both cell lines, which may help contribute towards understanding the mechanism underlying the suppressive effect of EF24 on HCC migration and invasion. Additionally, the expression of total- and phosphorylated-Src in primary HCC tissues and their paired lymph node metastatic tissues was detected, and phosphorylated-Src was found to be associated with HCC lymph node metastasis. The results of this study suggest that Src is a novel and promising therapeutic target in HCC and provide evidence to support the hypothesis that EF24 may be a useful therapeutic agent for the treatment of HCC.

A new layer of degradation mechanism for PR-Set7/Set8 during cell cycle

Set8 is critically involved in transcription regulation, cell cycle progression and genomic stability. Emerging evidence has revealed that E3 ubiquitin ligases such as CRL4^cdt2 and SCF^Skp2 regulate Set8 protein abundance. However, it is unclear whether other E3 ligase(s) could govern Set8 level for proper cell cycle progression in response to genotoxic stress such as UV irradiation. Recently, we report that the SCF^β-TRCP complex regulates Set8 protein stability by targeting it for ubiquitination and subsequent degradation. Notably, Set8 interacts with the SCF^β-TRCP E3 ligase complex. We further revealed a critical role of CKI in SCF^β-TRCP-mediated degradation of Set8. Mechanistically, CKI-mediated phosphorylation of Set8 at the S253 site promotes its destruction by SCF^β-TRCP. Importantly, SCF^β-TRCP-dependent Set8 destruction also contributes to the tight control of cell proliferation and cell cycle progression, in response to UV irradiation. Here, we summarize our new findings regarding the crucial role of β-TRCP in CKI-mediated Set8 degradation, which could provide new evidence to support that dysregulation of a tight regulatory network of Set8 could lead to aberrant cell cycle process.

MicroRNAs associated with small bowel neuroendocrine tumours and their metastases

Novel molecular analytes are needed in small bowel neuroendocrine tumours (SBNETs) to better determine disease aggressiveness and predict treatment response. In this study, we aimed to profile the global miRNome of SBNETs, and identify microRNAs (miRNAs) involved in tumour progression for use as potential biomarkers. Two independent miRNA profiling experiments were performed (n=90), including primary SBNETs (n=28), adjacent normal small bowel (NSB; n=14), matched lymph node (LN) metastases (n=24), normal LNs (n=7), normal liver (n=2) and liver metastases (n=15). We then evaluated potentially targeted genes by performing integrated computational analyses. We discovered 39 miRNAs significantly deregulated in SBNETs compared with adjacent NSB. The most upregulated (miR-204-5p, miR-7-5p and miR-375) were confirmed by qRT-PCR. Two miRNAs (miR-1 and miR-143-3p) were significantly downregulated in LN and liver metastases compared with primary tumours. Furthermore, we identified upregulated gene targets for miR-1 and miR-143-3p in an existing SBNET dataset, which could contribute to disease progression, and show that these miRNAs directly regulate FOSB and NUAK2 oncogenes. Our study represents the largest global miRNA profiling of SBNETs using matched primary tumour and metastatic samples. We revealed novel miRNAs deregulated during SBNET disease progression, and important miRNA-mRNA interactions. These miRNAs have the potential to act as biomarkers for patient stratification and may also be able to guide treatment decisions. Further experiments to define molecular mechanisms and validate these miRNAs in larger tissue cohorts and in biofluids are now warranted.

Spices for Prevention and Treatment of Cancers

Spices have been widely used as food flavorings and folk medicines for thousands of years. Numerous studies have documented the antioxidant, anti-inflammatory and immunomodulatory effects of spices, which might be related to prevention and treatment of several cancers, including lung, liver, breast, stomach, colorectum, cervix, and prostate cancers. Several spices are potential sources for prevention and treatment of cancers, such as Curcuma longa (tumeric), Nigella sativa (black cumin), Zingiber officinale (ginger), Allium sativum (garlic), Crocus sativus (saffron), Piper nigrum (black pepper) and Capsicum annum (chili pepper), which contained several important bioactive compounds, such as curcumin, thymoquinone, piperine and capsaicin. The main mechanisms of action include inducing apoptosis, inhibiting proliferation, migration and invasion of tumors, and sensitizing tumors to radiotherapy and chemotherapy. This review summarized recent studies on some spices for prevention and treatment of cancers, and special attention was paid to bioactive components and mechanisms of action.

Current state of phenolic and terpenoidal dietary factors and natural products as non-coding RNA/microRNA modulators for improved cancer therapy and prevention

The epigenetic regulation of cancer cells by small non-coding RNA molecules, the microRNAs (miRNAs), has raised particular interest in the field of oncology. These miRNAs play crucial roles concerning pathogenic properties of cancer cells and the sensitivity of cancer cells towards anticancer drugs. Certain miRNAs are responsible for an enhanced activity of drugs, while others lead to the formation of tumor resistance. In addition, miRNAs regulate survival and proliferation of cancer cells, in particular of cancer stem-like cells (CSCs), that are especially drug-resistant and, thus, cause tumor relapse in many cases. Various small molecule compounds were discovered that target miRNAs that are known to modulate tumor aggressiveness and drug resistance. This review comprises the effects of naturally occurring small molecules (phenolic compounds and terpenoids) on miRNAs involved in cancer diseases.

Curcumin AntiCancer Studies in Pancreatic Cancer

Pancreatic cancer (PC) is one of the deadliest cancers worldwide. Surgical resection remains the only curative therapeutic treatment for this disease, although only the minority of patients can be resected due to late diagnosis. Systemic gemcitabine-based chemotherapy plus nab-paclitaxel are used as the gold-standard therapy for patients with advanced PC; although this treatment is associated with a better overall survival compared to the old treatment, many side effects and poor results are still present. Therefore, new alternative therapies have been considered for treatment of advanced PC. Several preclinical studies have demonstrated that curcumin, a naturally occurring polyphenolic compound, has anticancer effects against different types of cancer, including PC, by modulating many molecular targets. Regarding PC, in vitro studies have shown potent cytotoxic effects of curcumin on different PC cell lines including MiaPaCa-2, Panc-1, AsPC-1, and BxPC-3. In addition, in vivo studies on PC models have shown that the anti-proliferative effects of curcumin are caused by the inhibition of oxidative stress and angiogenesis and are due to the induction of apoptosis. On the basis of these results, several researchers tested the anticancer effects of curcumin in clinical trials, trying to overcome the poor bioavailability of this agent by developing new bioavailable forms of curcumin. In this article, we review the results of pre-clinical and clinical studies on the effects of curcumin in the treatment of PC.

Cathepsin L knockdown enhances curcumin-mediated inhibition of growth, migration, and invasion of glioma cells

Curcumin can be used to prevent and treat cancer. However, its exact underlying molecular mechanisms remain poorly understood. Cathepsin L, a lysosomal cysteine protease, is overexpressed in several cancer types. This study aimed to determine the role of cathepsin L in curcumin-mediated inhibition of growth, migration, and invasion of glioma cells. Results revealed that the activity of cathepsin L was enhanced in curcumin-treated glioma cells. Cathepsin L knockdown induced by RNA interference significantly promoted curcumin-induced cytotoxicity, apoptosis, and cell cycle arrest. The knockdown also inhibited the migration and invasion of glioma cells. Our results suggested that the inhibition of cathepsin L can enhance the sensitivity of glioma cells to curcumin. Therefore, cathepsin L may be a new target to enhance the efficacy of curcumin against cancers.

How Diet Intervention via Modulation of DNA Damage Response through MicroRNAs May Have an Effect on Cancer Prevention and Aging, an in Silico Study

The DNA damage response (DDR) is a molecular mechanism that cells have evolved to sense DNA damage (DD) to promote DNA repair, or to lead to apoptosis, or cellular senescence if the damage is too extensive. Recent evidence indicates that microRNAs (miRs) play a critical role in the regulation of DDR. Dietary bioactive compounds through miRs may affect activity of numerous genes. Among the most studied bioactive compounds modulating expression of miRs are epi-gallocatechin-3-gallate, curcumin, resveratrol and n3-polyunsaturated fatty acids. To compare the impact of these dietary compounds on DD/DDR network modulation, we performed a literature search and an in silico analysis by the DIANA-mirPathv3 software. The in silico analysis allowed us to identify pathways shared by different miRs involved in DD/DDR vis-à-vis the specific compounds. The results demonstrate that certain miRs (e.g., -146, -21) play a central role in the interplay among DD/DDR and the bioactive compounds. Furthermore, some specific pathways, such as "fatty acids biosynthesis/metabolism", "extracellular matrix-receptor interaction" and "signaling regulating the pluripotency of stem cells", appear to be targeted by most miRs affected by the studied compounds. Since DD/DDR and these pathways are strongly related to aging and carcinogenesis, the present in silico results of our study suggest that monitoring the induction of specific miRs may provide the means to assess the antiaging and chemopreventive properties of particular dietary compounds.

Epigallocatechin-3-gallate inhibits migration and invasion of human renal carcinoma cells by downregulating matrix metalloproteinase-2 and matrix metalloproteinase-9

The anticancer properties of epigallocatechin-3-gallate (EGCG) are documented in the treatment of several types of cancer; however, there is no relevant evidence for its efficacy in the treatment of renal cell carcinoma (RCC). In the present study, the therapeutic effects of EGCG in vitro were investigated, with particular attention to the metastatic behavior of human RCC cells. MTT assays and flow cytometry were performed to detect the effects of EGCG on the proliferation and apoptosis of RCC cells. The migration and invasion abilities of RCC cells following treatment with EGCG were assessed by wound-healing and Transwell assays, respectively. Gelatin zymography and western blot analysis were performed to analyze the effect of EGCG on matrix metalloproteinase-2 (MMP-2) and MMP-9 expression levels. The results suggested that EGCG was able to inhibit the proliferation of RCC cells, induce apoptosis and effectively suppressed the migration and invasion of RCC cells. In addition, EGCG treatment resulted in the downregulation of MMP-2 and MMP-9 in RCC cells. We hypothesize that the anticancer effect associated with EGCG may involve the downregulation of MMP-2 and MMP-9. The present results suggest the potential of EGCG as a novel therapeutic agent against RCC.

Role of microRNA-7 in digestive system malignancy

There are several malignancies of the digestive system (including gastric, pancreatic and colorectal cancers, and hepatocellular carcinoma), which are the most common types of cancer and a major cause of death worldwide. MicroRNA (miR)-7 is abundant in the pancreas, playing an important role in pancreatic development and endocrine function. Expression of miR-7 is downregulated in digestive system malignancies compared with normal tissue. Although there are contrasting results for miR-7 expression, almost all research reveals that miR-7 is a tumor suppressor, by targeting various genes in specific pathways. Moreover, miR-7 can target different genes simultaneously in different malignancies of the digestive system. By acting on many cytokines, miR-7 is also involved in many gastrointestinal inflammatory diseases as a significant carcinogenic factor. Consequently, miR-7 might be a biomarker or therapeutic target gene in digestive system malignancies.

Noncoding RNAs and pancreatic cancer

Noncoding RNAs (ncRNAs) represent a class of RNA molecules that typically do not code for proteins. Emerging data suggest that ncRNAs play an important role in several physiological and pathological conditions such as cancer. The best-characterized ncRNAs are the microRNAs (miRNAs), which are short, approximately 22-nucleotide sequences of RNA of approximately 22-nucleotide in length that regulate gene expression at the posttranscriptional level, through transcript degradation or translational repression. MiRNAs can function as master gene regulators, impacting a variety of cellular pathways important to normal cellular functions as well as cancer development and progression. In addition to miRNAs, long ncRNAs, which are transcripts longer than 200 nucleotides, have recently emerged as novel drivers of tumorigenesis. However, the molecular mechanisms of their regulation and function, and the significance of other ncRNAs such as piwi-interacting RNAs in pancreas carcinogenesis are largely unknown. This review summarizes the growing body of evidence supporting the vital roles of ncRNAs in pancreatic cancer, focusing on their dysregulation through both genetic and epigenetic mechanisms, and highlighting the promise of ncRNAs in diagnostic and therapeutic applications of pancreatic cancer.

Down-regulation of miR-223 reverses epithelial-mesenchymal transition in gemcitabine-resistant pancreatic cancer cells

Recent studies have demonstrated that acquisition of epithelial-to-mesenchymal transition (EMT) is associated with drug resistance in pancreatic cancer cells; however, the underlying mechanisms are not fully elucidated. Emerging evidence suggests that microRNAs play a crucial role in controlling EMT. The aims of this study were to explore the potential role of miR-223 in governing EMT in gemcitabine-resistant (GR) pancreatic cancer cells. To achieve this goal, real-time reverse transcription-PCR and western blot analysis were used to validate whether GR cells acquired EMT in AsPC-1 and PANC-1 cells. Invasion, migration, and detachment assays were performed to further identify the EMT characteristics in GR cells. The miR-223 inhibitor was used to determine its role in GR-induced EMT. We found that GR cells acquired EMT features, which obtained elongated fibroblastoid morphology, decreased expression of epithelial marker E-cadherin, and up-regulation of mesenchymal markers. Furthermore, we observed that GR cells are associated with high expression of miR-223. Notably, inhibition of miR-223 led to the reversal of EMT phenotype. More importantly, miR-223 governs GR-induced EMT in part due to down-regulation of its target Fbw7 and subsequent upregulation of Notch-1 in pancreatic cancer. Our study implied that down-regulation of miR-223 could be a novel therapy for pancreatic cancer.

MicroRNAs as biomarkers and prospective therapeutic targets in colon and pancreatic cancers

Colon and pancreatic cancers have high mortality rates due to early metastasis prior to the onset of symptoms. Screening tests for colorectal cancer are invasive and expensive. No effective screening is available for pancreatic cancer. Identification of biomarkers for early detection in both of these cancers is being extensively researched. MicroRNAs (miRNA) are small non-coding molecule biomarkers that regulate cancers. Measurement of miRNAs in pancreatic fluid or blood could be a preferred non-invasive screening method. The regulation of colon and pancreatic cancers by miRNA is complex. miRNA play a central role in inflammation, invasiveness, and tumor progression in these two cancers, as well as regulation of the NF-κB pathway. miRNA's evolving role in screening is also reviewed.

Curcumin improves the efficacy of cisplatin by targeting cancer stem-like cells through p21 and cyclin D1-mediated tumour cell inhibition in non-small cell lung cancer cell lines

Natural compounds such as curcumin have the ability to enhance the therapeutic effectiveness of common chemotherapy agents through cancer stem-like cell (CSC) sensitisation. In the present study, we showed that curcumin enhanced the sensitivity of the double-positive (CD166⁺/EpCAM⁺) CSC subpopulation in non-small cell lung cancer (NSCLC) cell lines (A549 and H2170) to cisplatin-induced apoptosis and inhibition of metastasis. Our results revealed that initial exposure of NSCLC cell lines to curcumin (10–40 µM) markedly reduced the percentage of viability to an average of ~51 and ~54% compared to treatment with low dose cisplatin (3 µM) with only 94 and 86% in both the A549 and H2170 cells. Moreover, sensitisation of NSCLC cell lines to curcumin through combined treatment enhanced the single effect induced by low dose cisplatin on the apoptosis of the double-positive CSC subpopulation by 18 and 20% in the A549 and H2170 cells, respectively. Furthermore, we found that curcumin enhanced the inhibitory effects of cisplatin on the highly migratory CD166⁺/EpCAM⁺ subpopulation, marked by a reduction in cell migration to 9 and 21% in the A549 and H2170 cells, respectively, indicating that curcumin may increase the sensitivity of CSCs to cisplatin-induced migratory inhibition. We also observed that the mRNA expression of cyclin D1 was downregulated, while a substantial increased in p21 expression was noted, followed by Apaf1 and caspase-9 activation in the double-positive (CD166⁺/EpCAM⁺) CSC subpopulation of A549 cells, suggested that the combined treatments induced cell cycle arrest, therefore triggering CSC growth inhibition via the intrinsic apoptotic pathway. In conclusion, we provided novel evidence of the previously unknown therapeutic effects of curcumin, either alone or in combination with cisplatin on the inhibition of the CD166⁺/EpCAM⁺ subpopulation of NSCLC cell lines. This finding demonstrated the potential therapeutic approach of using curcumin that may enhance the effects of cisplatin by targeting the CSC subpopulation in NSCLC.

MicroRNA-7: a promising new target in cancer therapy

The incidence of tumors with life-threatening effects has increased gradually over time; however, the mechanisms involved in tumor development have not been fully elucidated. Recent studies have shown that microRNA-7 (miR-7), which is endogenous non-coding RNA molecules of approximately 23 nucleotides, plays an important role in the occurrence and development of tumors as a key tumor suppressor. Mechanistic evidence showed that miR-7 is closely related to the growth, metastasis, and prognosis of various malignant tumors through regulating different target molecules, which suggest that miR-7 may be a new target for the clinical diagnosis and treatment of various tumors. In this review, we summarize current knowledge of the relationship between miR-7 and tumor development, diagnosis, and treatment.

Curcumin inhibits cell proliferation and induces apoptosis of human non-small cell lung cancer cells through the upregulation of miR-192-5p and suppression of PI3K/Akt signaling pathway

Curcumin is the main active ingredient extracted from the traditional Chinese medicine, turmeric, which acts against non-small cell lung cancer cell (NSCLC), lowers blood pressure, is anti-inflammatory, choleretic, and exerts anti‑oxidant effects, without any obvious toxicity in the long term. The aim of the present study was to investigate whether the anticancer effect of curcumin inhibited cell proliferation and induced apoptosis of human NSCLC through the upregulation of microRNA‑192-5p (miR-192-5p) and suppression of the PI3K/Akt signaling pathway. In the present study, treatment with curcumin inhibited cell proliferation, induced cell apoptosis and increased the caspase-3 activity of A549 cells. The results also showed that, miR-192-5p relative expression of NCL-H460 cells was relatively lower than that of A549 cells, which was higher, with that of BEAS-2E cells being the highest. miR-192-5p mimics suppressed cell proliferation and increased cell apoptosis of A549 cells. However, anti-miR-192-5p mimics increased cell proliferation and inhibited cell apoptosis of A549 cells. Curcumin treatment effectively increased the relative miR‑192-5p expression and suppressed the PI3K/Akt signaling pathway. miR-192-5p mimics enhanced the effect of curcumin on cell viability and apoptosis and suppressed the PI3K/Akt signaling pathway in A549 cells. Anti-miR-192-5p mimics reversed the effect of curcumin on A549 cells and PI3K/Akt expression. Collectively, our findings suggested that curcumin inhibited cell proliferation and induced apoptosis of human non-small cell lung cancer cells through the upregulation of miR-192-5p and suppression of the PI3K/Akt signaling pathway.

Recent Advances of Curcumin and its Analogues in Breast Cancer Prevention and Treatment

More than 230,000 diagnosed cases of invasive breast cancer in women was estimated in 2014 and an expected 40,000 deaths attributed to the aggressive carcinoma. An effective approach to diminish the morbidity and mortality of breast cancer is the development of chemopreventive and chemotherapeutic agents. Nutraceuticals have demonstrated their ability to proficiently halt carcinogenesis. The administration of natural compounds able to effectively serve as chemoprevention and chemotherapeutics without causing harm or adverse effects is imperative. Curcumin derived from the rhizome of Curcuma longa L., is a common spice of India, used for centuries because of its medicinal properties. The main component of curcumin possesses a wide range of biological activities; anti-proliferative, anti-inflammatory, and apoptotic characteristics modulated through the inactivation of pathways such as EGK and Akt/mTOR. In addition, curcumin alters the expression of cytokines, transcription factors, and enzymes involved in cell vitality. The in vivo application of curcumin in breast cancer is hindered by its limited bioavailabiity. The synthesis of curcumin analogues and delivery via nanoparticles has demonstrated enhanced bioavailability of curcumin in the malignancy. This review focuses on recent developments in the use of curcumin, curcumin analogues, and novel delivery systems as a preventive and therapeutic method for breast cancer.

Clinical Potential of microRNA-7 in Cancer

microRNAs (miRNAs) are a family of short, non-coding RNA molecules that drive a complex network of post-transcriptional gene regulation by enhancing target mRNA decay and/or inhibiting protein synthesis from mRNA transcripts. They regulate genes involved in key aspects of normal cell growth, development and the maintenance of body homeostasis and have been closely linked to the development and progression of human disease, in particular cancer. Over recent years there has been much interest regarding their potential as biomarkers and as therapeutic agents or targets. microRNA-7 (miR-7) is a 23 nucleotide (nt) miRNA known primarily to act as a tumour suppressor. miR-7 directly inhibits a number of oncogenic targets and impedes various aspects of cancer progression in vitro and in vivo, however, some studies have also implicated miR-7 in oncogenic roles. This review summarises the role of miR-7 in cancer, its potential in miRNA-based replacement therapy and its capacity as both a diagnostic and prognostic biomarker.

MicroRNA-7/NF-κB signaling regulatory feedback circuit regulates gastric carcinogenesis

RELA and FOS are targets of miR-7 in gastric cancer cells and the miR-7/IKKε/RELA reciprocal feedback loop is important for gastric cancer induced by H. pylori infection.

MicroRNAs play essential roles in gene expression regulation during carcinogenesis. Here, we investigated the role of miR-7 and the mechanism by which it is dysregulated in gastric cancer (GC). We used genome-wide screenings and identified RELA and FOS as novel targets of miR-7. Overexpression of miR-7 repressed RELA and FOS expression and prevented GC cell proliferation and tumorigenesis. These effects were clinically relevant, as low miR-7 expression was correlated with high RELA and FOS expression and poor survival in GC patients. Intriguingly, we found that miR-7 indirectly regulated RELA activation by targeting the IκB kinase IKKε. Furthermore, IKKε and RELA can repress miR-7 transcription, which forms a feedback circuit between miR-7 and nuclear factor κB (NF-κB) signaling. Additionally, we demonstrate that down-regulation of miR-7 may occur as a result of the aberrant activation of NF-κB signaling by Helicobacter pylori infection. These findings suggest that miR-7 may serve as an important regulator in GC development and progression.

MicroRNA-33b, upregulated by EF24, a curcumin analog, suppresses the epithelial-to-mesenchymal transition (EMT) and migratory potential of melanoma cells by targeting HMGA2

Diphenyl difluoroketone (EF24), a curcumin analog, exhibits potent anti-tumor activities by arresting cell cycle and inducing apoptosis. However, the efficacy and modes of action of EF24 on melanoma metastasis remain elusive. In this study, we found that at non-cytotoxic concentrations, EF24 suppressed cell motility and epithelial-to-mesenchymal Transition (EMT) of melanoma cell lines, Lu1205 and A375. EF24 also suppressed HMGA2 expression at mRNA and protein levels. miR-33b directly bound to HMGA2 3' untranslated region (3'-UTR) to suppress its expression as measured by dual-luciferase assay. EF24 increased expression of E-cadherin and decreased STAT3 phosphorylation and expression of the mesenchymal markers, vimentin and N-cadherin. miR-33b inhibition or HMGA2 overexpression reverted EF24-mediated suppression of EMT phenotypes. In addition, EF24 modulated the HMGA2-dependent actin stress fiber formation, focal adhesion assembly and FAK, Src and RhoA activation by targeting miR-33b. Thus, the results suggest that EF24 suppresses melanoma metastasis via upregulating miR-33b and concomitantly reducing HMGA2 expression. The observed activities of EF24 support its further evaluation as an anti-metastatic agent in melanoma therapy.

Synergistic effects of curcumin and bevacizumab on cell signaling pathways in hepatocellular carcinoma

The aim of the present study was to explore the effects of curcumin in combination with bevacizumab on the vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR)/K-ras pathway in hepatocellular carcinoma. A total of 30 Sprague Dawley (SD) rats were randomly divided into five groups: Control, model, curcumin, VEGF blocker, and curcumin + VEGF blocker groups. The mRNA levels of VEGF and VEGFR in all groups were subsequently measured by quantitative reverse transcriptase-polymerase chain reaction and the protein expression of K-ras was detected by western blot analysis. Compared with the control group, the mRNA levels of VEGF and VEGFR were revealed to be significantly increased in the model, curcumin and VEGF blocker groups. The VEGF mRNA levels in the curcumin, VEGF blocker and curcumin + VEGF blocker groups were all decreased when compared with the model group. In addition, the VEGF mRNA levels in the curcumin + VEGF blocker group were significantly lower compared with the curcumin group (P<0.05). The VEGF mRNA levels in the curcumin, VEGF blocker and curcumin + VEGF blocker groups were decreased when compared with the model group (P=0.0001). No significant differences in VEGF mRNA levels were identified between the VEGF blocker and curcumin groups (P=0.863), whereas the VEGF mRNA levels in the curcumin + VEGF blocker group were significantly lower than that of the curcumin group (P=0.025). Curcumin and the VEGF blocker are each capable of inhibiting hepatocellular carcinoma progression by regulating the VEGF/VEGFR/K-ras pathway. The combination of the two compounds has a synergistic effect on the inhibition of the effects of the VEGF signaling pathways in hepatocellular carcinoma progression.