MiR‐376a suppresses the proliferation and invasion of non‐small‐cell lung cancer by targeting c‐Myc

It has been reported that miR‐376a is involved in the formation and progression of several types of cancer. However, the expression and function of miR‐376a is still unknown in non‐small cell lung carcinomas (NSCLC). In this study, the expression of miR‐376a in NSCLC tissues and cell lines were examined by real‐time PCR, the effects of miR‐376a on cell proliferation, apoptosis and invasion were evaluated in vitro. Luciferase reporter assay was performed to identify the targets of miR‐376a. The results showed that miR‐376a was significantly downregulated in NSCLC tissues and cell lines. Restoration of miR‐376a in NSCLC cell line A549 significantly inhibited cell proliferation, increased cell apoptosis and suppressed cell invasion, compared with control‐transfected A549 cells. Luciferase reporter assay showed that c‐Myc, an oncogene that regulating cell survival, angiogenesis and metastasis, was a direct target of miR‐376a. Over‐expression of miR‐376a decreased the mRNA and protein levels of c‐Myc in A549 cells. In addition, upregulation of c‐Myc inhibited miR‐376a‐induced inhibition of cell proliferation and invasion in A549 cells. Therefore, our results indicate a tumor suppressor role of miR‐376a in NSCLC by targeting c‐Myc. miR‐376a may be a promising therapeutic target for NSCLC.     

Simultaneous silencing of VEGF and KSP by siRNA cocktail inhibits proliferation and induces apoptosis of hepatocellular carcinoma Hep3B cells

Background

Vascular endothelial growth factor (VEGF) is involved in the growth of new blood vessels that feed tumors and kinesin spindle protein (KSP) plays a critical role in mitosis involving in cell proliferation. Simultaneous silencing of VEGF and KSP, an attractive and viable approach in cancer, leads on restricting cancer progression. The purpose of this study is to examine the therapeutic potential of dual gene targeted siRNA cocktail on human hepatocellular carcinoma Hep3B cells.

Results

The predesigned siRNAs could inhibit VEGF and KSP at mRNA level. siRNA cocktail showed a further downregulation on KSP mRNA and protein levels compared to KSP-siRNA or VEGF-siRNA, but not on VEGF expression. It also exhibited greater suppression on cell proliferation as well as cell migration or invasion capabilities and induction of apoptosis in Hep3B cells than single siRNA simultaneously. This could be explained by the significant downregulation of Cyclin D1, Bcl-2 and Survivin. However, no sigificant difference in the mRNA and protein levels of ANG2, involving inhibition of angiogenesis was found in HUVECs cultured with supernatant of Hep3B cells treated with siRNA cocktail, compared to that of VEGF-siRNA.

Conclusion

Silencing of VEGF and KSP plays a key role in inhibiting cell proliferation, migration, invasion and inducing apoptosis of Hep3B cells. Simultaneous silencing of VEGF and KSP using siRNA cocktail yields promising results for eradicating hepatocellular carcinoma cells, a new direction for liver cancer treatment.     

小干扰RNA靶向VEGF基因体内外抑制乳腺癌细胞MCF-7的增殖

 血管生成与肿瘤生长、侵袭、转移密切相关.血管内皮生长因子能特异地促进内皮细胞分裂、增殖及迁移,在肿瘤新生血管生成过程中起着至关重要的作用.通过RNAi抑制VEGF表达的抗血管生成疗法可有效应用于肿瘤治疗.本研究采用化学修饰的siRNA在体内外抑制VEGF基因表达,探讨化学修饰的siRNA介导的RNA干扰技术在乳腺癌基因治疗的可行性和特异性.选用阳离子脂质体Lipofectamine^TM2000作为转染试剂,将针对人VEGF基因的小干扰RNA(small interfering RNA,siRNA)转染人类乳腺细胞株MCF-7和裸鼠移植瘤,在体内外诱导RNAi.采用四甲基偶氮唑蓝（MTT）法,逆转录聚合酶链反应(RT-PCR),蛋白印迹实验等检测siRNA治疗组和对照组VEGF基因表达及细胞增殖变化.体外实验结果显示：靶向VEGF基因siRNA转染乳腺癌MCF-7细胞后,细胞生长抑制率达52.5%;VEGF的mRNA和蛋白表达水平显著降低（P<0.01）;裸鼠体内实验结果显示：siRNA治疗组瘤组织的增长受到明显抑制;RT-PCR结果同时表明治疗组VEGF表达下调.体内外对照组各指标无显著变化.化学修饰的siRNA介导的RNAi在体内外均能成功下调靶基因VEGF的表达,抑制MCF-7细胞增殖,是潜在的肿瘤治疗新方法.     

siRNA沉默VEGF基因对大肠癌细胞生物学特性的影响

目的研究VEGF和受体FLT-1、FLK-1在大肠癌组织中的表达及与临床病理因素之间的关系;观察SiRNA干扰VEGF基因对人大肠癌细胞系Caco-2生物学特性的影响。方法应用免疫组织化学S?P法,检测82例大肠癌及14例大肠正常黏膜组织中VEGF和FLT-1、FLK-1的表达;以脂质体lip-2000为载体,用针对VEGF特异靶点的siRNA转染入人大肠癌细胞系Caco-2后,免疫细胞化学S-P法、Western Blot检测VEGF蛋白表达变化,MTT法检测对细胞增殖的影响;流式细胞技术检测细胞凋亡。结果 (1)大肠癌组织VEGF和受体FLT-1、FLK-1阳性表达率显著高于正常大肠组织(P0.05)。VEGF的表达在有无淋巴结转移组和不同的Duke’s分期中亦有显著差异(P0.05)。(2)VEGF-siRNA转染Caco-2细胞后,免疫细胞化学结果显示转染VEGF-siRNA组阳性细胞呈弱阳性表达,明显减弱;Westernblot结果显示VEGF-siRNA组细胞的蛋白条带亮度明显降低;MTT检测VEGF-siRNA组细胞生长出现明显的抑制(P0.05),不同时段(24h、48h、72h)肿瘤细胞增殖抑制率之间有显著差异(P0.05);流式细胞术检测VEGF-siRNA组出现明显亚二倍体峰,凋亡率显著高于正常对照组(P0.01)。结论 VEGF在大肠癌的进展过程中起重要作用。siRNA干扰VEGF基因能有效抑制人大肠癌细胞系VEGF蛋白表达,细胞增殖能力减弱,促进细胞凋亡。以VEGF基因为靶点,利用siRNA技术进行基因治疗有可能成为一种新的有效手段。     

Furanodienone inhibits cell proliferation and survival by suppressing ERα signaling in human breast cancer MCF-7 cells

Estrogen receptor alpha (ERα) plays an important role in the development and progression of breast cancer and thus the attenuation of ERα activities is a promising treatment strategy. Furanodienone is one of the main bioactive chemical components of Rhizoma Curcumae which is commonly used in Chinese medicine for the treatment of cancer. In this study, we investigated the effects of furanodienone on human breast cancer MCF‐7, T47D, and MDA‐MB‐231 cells. Our results showed that furanodienone could inhibit MCF‐7, T47D, and MDA‐MB‐231 cells proliferation in a dose (10–160 µM) dependent manner. ERα‐negative MDA‐MB‐231 cells were less sensitive to furanodienone than ERα‐positive MCF‐7 and T47D cells. Furanodienone could effectively block 17β‐estradiol (E2)‐stimulated MCF‐7 cell proliferation and cell cycle progression and induce apoptosis evidenced by the flow cytometric detection of sub‐G1 DNA content and the appearance of apoptotic nuclei after DAPI staining. Furanodienone specifically down‐regulated ERα protein and mRNA expression levels without altering ERβ expression. Furanodienone treatment inhibited E2‐stimulation of estrogen response element (ERE)‐driven reporter plasmid activity and ablated E2‐targeted gene (e.g., c‐Myc, Bcl‐2, and cyclin D1) expression which resulted in the inhibition of cell cycle progression and cell proliferation, and in the induction of apoptosis. Knockdown of ERα in MCF‐7 cells by ERα‐specific siRNA decreased the cell growth inhibitory effect of furanodienone. These findings suggest that effects of furanodienone on MCF‐7 cells are mediated, at least in part, by inhibiting ERα signaling. J. Cell. Biochem. 112: 217–224, 2011. © 2010 Wiley‐Liss, Inc.     

Consumption of hydrogen-rich water alleviates renal injury in spontaneous hypertensive rats

The aim of this study was to investigate the inhibitory effect of a siRNA cocktail targeting Vascular endothelial growth factor (VEGF) and Human epidermal growth factor receptor 2 (HER2) on cell proliferation, induced apoptosis and the expression of VEGF and HER2 in human gastric carcinoma cell. The silencing rate of pre-designed siRNAs that targeted VEGF and HER2 was detected by Real-time Quantitative PCR (RT-QPCR) analysis. Furthermore, the best silencing siRNA that targeted VEGF and HER2 was prepared as a cocktail to co-knockdown VEGF and HER2 expression at both mRNA and protein levels which were detected by RT-QPCR and Western blot analysis. Cell proliferation inhibition rates were determined by CCK8 assay. The effect of siRNA cocktail on cell apoptosis was determined by flow cytometry. The migration inhibition of siRNA cocktail was analyzed by wound-healing assay. The ability of VEGF to induce endothelial cells to proliferate was examined in HUVECs by the method of tube formation assay. The pre-designed siRNAs could inhibit VEGF and HER2 mRNA level. siRNA cocktail, and co-downregulation of VEGF and HER2 result in significant inhibition of gastric cancer growth and migration in vitro. The inhibition of VEGF and HER2 expressions can induce apoptosis of SGC-7901 cells.     

The MK5/PRAK kinase and Myc form a negative feedback loop that is disrupted during colorectal tumorigenesis

Expression of the Myc oncoprotein is downregulated in response to stress signals to allow cells to cease proliferation and escape apoptosis, but the mechanisms involved in this process are poorly understood. Cell cycle arrest in response to DNA damage requires downregulation of Myc via a p53-independent signaling pathway. Here we have used siRNA?screening of the human kinome to identify MAPKAPK5 (MK5, PRAK) as a negative regulator of Myc expression. MK5 regulates translation of Myc, since it is required for expression of miR-34b and miR-34c that bind to the 3'UTR of MYC. MK5 activates miR-34b/c expression via phosphorylation of FoxO3a, thereby promoting nuclear localization of FoxO3a and enabling it to induce miR-34b/c expression and arrest proliferation. Expression of MK5 in turn is directly activated by Myc, forming a negative feedback loop. MK5 is downregulated in colon carcinomas, arguing that this feedback loop is disrupted during colorectal tumorigenesis.     

Embelin Suppresses Growth of Human Pancreatic Cancer Xenografts,and Pancreatic Cancer Cells Isolated from KrasG12D Mice by Inhibiting Akt and Sonic Hedgehog Pathways

Pancreatic cancer is a deadly disease, and therefore effective treatment and/or prevention strategies are urgently needed. The objectives of this study were to examine the molecular mechanisms by which embelin inhibited human pancreatic cancer cell growth in vitro, and xenografts in Balb C nude mice, and pancreatic cancer cell growth isolated from Kras^G12D transgenic mice. XTT assays were performed to measure cell viability. AsPC-1 cells were injected subcutaneously into Balb c nude mice and treated with embelin. Cell proliferation and apoptosis were measured by Ki67 and TUNEL staining, respectively. The expression of Akt, and Sonic Hedgehog (Shh) and their target gene products were measured by the immunohistochemistry, and Western blot analysis. The effects of embelin on pancreatic cancer cells isolated from 10-months old Kras^G12D mice were also examined. Embelin inhibited cell viability in pancreatic cancer AsPC-1, PANC-1, MIA PaCa-2 and Hs 766T cell lines, and these inhibitory effects were blocked either by constitutively active Akt or Shh protein. Embelin-treated mice showed significant inhibition in tumor growth which was associated with reduced expression of markers of cell proliferation (Ki67, PCNA and Bcl-2) and cell cycle (cyclin D1, CDK2, and CDK6), and induction of apoptosis (activation of caspase-3 and cleavage of PARP, and increased expression of Bax). In addition, embelin inhibited the expression of markers of angiogenesis (COX-2, VEGF, VEGFR, and IL-8), and metastasis (MMP-2 and MMP-9) in tumor tissues. Antitumor activity of embelin was associated with inhibition of Akt and Shh pathways in xenografts, and pancreatic cancer cells isolated from Kras^G12D mice. Furthermore, embelin also inhibited epithelial-to-mesenchymal transition (EMT) by up-regulating E-cadherin and inhibiting the expression of Snail, Slug, and ZEB1. These data suggest that embelin can inhibit pancreatic cancer growth, angiogenesis and metastasis by suppressing Akt and Shh pathways, and can be developed for the treatment and/or prevention of pancreatic cancer.     

Lentiviral Vector-Mediated siRNA Knockdown of c-MYC: Cell Growth Inhibition and Cell Cycle Arrest at G2/M Phase in Jijoye Cells

Inhibition of c-MYC has been considered as a potential therapy for lymphoma treatment. We explored a lentiviral vector-mediated small interfering RNA (siRNA) expression vector to stably reduce c-MYC expression in B cell line Jijoye cells and investigated the effects of c-MYC downregulation on cell growth, cell cycle, and apoptosis in vitro. The expression of c-MYC mRNA and protein levels were inhibited significantly by c-MYC siRNA. The c-MYC downregulation resulted in the inhibition of cell proliferation and cell cycle arrest at G2/M phase, which was associated with decreased expression of cyclin B and cyclin-dependent kinase 1 (CDK1) and increased expression of CDK inhibitor p21 proteins. In addition, downregulation of c-MYC induced cell apoptosis characterized by DNA fragmentation and caspase-3 activation. Taken together, these results suggest that lentiviral vector-mediated siRNA for c-MYC may be a promising approach for targeting c-MYC in the treatment of Burkitt lymphoma.     

CD155 knockdown promotes apoptosis via AKT/Bcl‐2/Bax in colon cancer cells

CD155, one of the nectin‐like molecule family members, is involved in cell adhesion and motility. CD155 is overexpressed in several human cancers, but its role in proliferation and apoptosis of colorectal cancer remains unclear. We found that CD155 was up‐regulated in colorectal cancer tissues. CD155 knockdown via shRNA lentiviruses inhibited colon cancers cell migration and invasion, with a reduction in the expression of FAK, Src and MMP‐2. CD155 down‐regulation also suppressed colon cancer cell proliferation, accompanied by changing expressions of some molecules related to cell cycle. Finally, CD155 knockdown increased the expression ratio between Bax and Bcl‐2, resulting in a significant increase in colon cancer cell apoptosis. Taken together, these results demonstrate that CD155 is involved in not only migration and invasion but also proliferation and survival abilities of colon cancer cells, suggesting that CD155 is one of key molecules promoting the growth and metastasis of colorectal cancer.     

Cooperation of Epac1/Rap1/Akt and PKA in prostaglandin E(2) -induced proliferation of human umbilical cord blood derived mesenchymal stem cells: Involvement of c-Myc and VEGF expression

Prostaglandin E₂ (PGE₂) is well known to regulate cell functions through cAMP; however, the role of exchange protein directly activated by cAMP (Epac1) and protein kinase A (PKA) in modulating such functions is unknown in human umbilical cord blood‐derived mesenchymal stem cells (hUCB‐MSCs). Therefore, we investigated the relationship between Epac1 and PKA during PGE₂‐induced hUCB‐MSC proliferation and its related signaling pathways. PGE₂ increased cell proliferation, and E‐type prostaglandin (EP) 2 receptor mRNA expression level and activated cAMP generation, which were blocked by EP2 receptor selective antagonist AH 6809. PGE₂ increased Epac1 expression, Ras‐related protein 1 (Rap1) activation level, and Akt phosphorylation, which were inhibited by AH 6809, adenylyl cyclase inhibitor SQ 22536, and Epac1/Rap1‐specific siRNA. Also, PGE₂ increased PKA activity, which was inhibited by AH 6809, SQ 22536, and PKA inhibitor PKI. HUCB‐MSCs were incubated with the Epac agonist 8‐pCPT‐cAMP or the PKA agonist 6‐phe‐cAMP to examine whether Epac1/Rap1/Akt activation was independent of PKA activation. 8‐pCPT‐cAMP increased Akt phosphorylation but not PKA activity. 6‐Phe‐cAMP increased PKA activity, but not Akt phosphorylation. Additionally, an Akt inhibitor or PKA inhibitor (PKI) did not block the PGE₂‐induced increase in PKA activity or Akt phosphorylation, respectively. Moreover, PGE₂ increased glycogen synthase kinase (GSK)‐3β phosphorylation and nuclear translocation of active‐β‐catenin, which were inhibited by Akt inhibitor or/and PKI. PGE₂ increased c‐Myc and vascular endothelial growth factor (VEGF) expression levels, which were blocked by β‐catenin siRNA. In conclusion, PGE₂ stimulated hUCB‐MSC proliferation through β‐catenin‐mediated c‐Myc and VEGF expression via Epac/Rap1/Akt and PKA cooperation. J. Cell. Physiol. 227: 3756–3767, 2012. © 2012 Wiley Periodicals, Inc.     

Dauricine induces apoptosis,inhibits proliferation and invasion through inhibiting NF‐κB signaling pathway in colon cancer cells

Dauricine, a bioactive component of Asiatic Moonseed Rhizome, has been widely used to treat a large number of inflammatory diseases in traditional Chinese medicine. In our study, we demonstrated that dauricine inhibited colon cancer cell proliferation and invasion, and induced apoptosis by suppressing nuclear factor‐kappaB (NF‐κB) activation in a dose‐ and time‐dependent manner. Addition of dauricine inhibited the phosphorylation and degradation of IκBα, and the phosphorylation and translocation of p65. Moreover, dauricine down‐regulated the expression of various NF‐κB‐regulated genes, including genes involved cell proliferation (cyclinD1, COX2, and c‐Myc), anti‐apoptosis (survivin, Bcl‐2, XIAP, and IAP1), invasion (MMP‐9 and ICAM‐1), and angiogenesis (VEGF). In athymic nu/nu mouse model, we further demonstrated that dauricine significantly suppressed colonic tumor growth. Taken together, our results demonstrated that dauricine inhibited colon cancer cell proliferation, invasion, and induced cell apoptosis by suppressing NF‐κB activity and the expression profile of its downstream genes. These findings provide evidence for a novel role of dauricine in preventing or treating colon cancer through modulation of NF‐κB singling pathway. J. Cell. Physiol. 225: 266–275, 2010. © 2010 Wiley‐Liss, Inc.     

Downregulation of integrin-linked kinase inhibits epithelial-to-mesenchymal transition and metastasis in bladder cancer cells

Integrin-linked kinase (ILK) is a multifunctional serine/threonine kinase in cytoplasm. Recent studies showed that cancer patients with increased ILK expression had low survival, poor prognosis and increased metastasis. Although the causes of ILK overexpression remain to be fully elucidated, accumulating evidence suggests that its oncogenic capacity derives from its regulation of several downstream targets that provide cells with signals that promote proliferation, survival and migration. However, the mechanisms underlying tumor metastasis by ILK is still not fully understood. Epithelial–mesenchymal transition (EMT) is a critical event of cancer cells that triggers invasion and metastasis. We recently reported that knockdown of ILK inhibited the growth and induced apoptosis in human bladder cancer cells. Therefore, we postulate that ILK might involve in EMT. Here we further investigate the function of ILK with RNA interference in bladder cancer cells. Knockdown of ILK impeded an EMT with low Vimentin, Snail, Slug and Twist as well as high E-cadherin expression in vivo and vitro. In addition, we found that knockdown of ILK inhibited cell proliferation, migration and invasion as well as changed cell morphology, adhesion and rearranged cytoskeleton in vitro. We also demonstrated that ILK siRNA inhibited phosphorylation of downstream signaling targets Akt and GSK3β, increased expression of nm23-H1, as well as reduced expression of MMP-2 and MMP-9 in vivo and vitro. Furthermore, downregulation of ILK could increase expression of Ribonuclease inhibitor (RI), an important acidic cytoplasmic protein with many functions. Finally, the effects of ILK siRNA on bladder cancer cell phenotype and invasiveness translate into suppression for tumorigenesis and metastasis in vivo. Taken together, our findings highlight that ILK signaling pathway plays a novel role in the development of bladder cancer through regulating EMT. ILK could be a promising diagnostic marker and therapeutic target for bladder cancer.     

PKCδ knockdown inhibits free fatty acid induction of endothelial cell apoptosis

The mechanisms whereby free fatty acids induce endothelial cell apoptosis are not yet understood. The present study aimed to investigate the role of PKCδ in free fatty acid–induced endothelial cell apoptosis. In addition, we looked for evidence of apoptosis‐related interactions between PKCδ and Fas signal pathway. Human umbilical vein endothelial cells were treated with various concentrations of free fatty acids and transiently transfected with PKCδ siRNA or Fas siRNA to inhibit PKCδ or Fas expression. Cell proliferation was determined through colorimetric assays, and apoptosis was quantified using flow cytometry. Protein expression was determined from cell lysates using Western blots with antibodies against p‐PKCδTyr512, PKCδ, and Fas. Statistical analyses were performed. Free fatty acids had multiple effects on human umbilical vein endothelial cells, including concentration‐dependent inhibition of cell proliferation, induction of apoptosis, increased Fas expression, and increased PKCδ expression and phosphorylation. Inhibition of PKCδ mRNA expression by PKCδ siRNA led to a reduction in both free fatty acid–induced apoptosis and Fas expression. However, Fas siRNA treatment inhibited Fas, but not PKCδ, expression in human umbilical vein endothelial cells. The free fatty acid–induced apoptosis in endothelial cells are possibly mediated by PKCδ and may involve upregulation of its downstream Fas. Copyright © 2012 John Wiley & Sons, Ltd.     

慢病毒介导的RNA干涉对乳腺癌SKBR3细胞HER2受体的下调及生长抑制

大约30％的乳腺癌中有表皮生长因子受体家族蛋白HER2的过表达,此类癌症的预后差,恶性程度高。RNA干涉（RNAi）是最近发展起来能特异性抑制哺乳动物细胞中基因表达的新技术。本文在以往获得的能够产生良好基因沉默效应的小干涉RNA（siRNA）的基础上,构建了U6和H1双启动子siRNA表达载体,并转染HER2高表达乳腺癌SKBR3细胞定量测定了其HER2下调效应。随后,siRNA表达盒经LR重组反应被克隆入慢病毒载体中,在成功包装成病毒后,感染SKBR3并经荧光定量PCR、蛋白印迹杂交和流式细胞仪一系列实验证明慢病毒介导的RNAi确实能有效地下调肿瘤抗原HER2的表达。细胞长期增殖实验表明经慢病毒处理后细胞生长得到抑制。我们的研究为进一步阐明HER2与癌症恶化的关系以及发展新的基因治疗药物提供了工具和可能。     

Betulinic acid induces apoptosis and inhibits metastasis of human colorectal cancer cells in vitro and in vivo

Betulinic acid (BA) is a pentacyclic triterpenoids extracted from birch with a wide range of biological properties. Recent studies have shown that BA has significant cytotoxicity to various types of human cancer cells, and shows potential in cancer treatment. However, the efficacy of BA on human colorectal cancer tumor cells is still unclear. The purpose of our study was to evaluate the anti-cancer activity of BA in human colorectal cancer cells in vitro and in vivo to investigate the possible mechanism. In this experiment, we found that BA inhibited colorectal cancer cell lines in vitro with a time-dependent and dose-dependent manner. Moreover, BA could induce cell apoptosis by upregulating expression of Bax and cleaved caspase-3 and downregulating protein of Bcl-2. BA could increase the production of reactive oxygen species and reduce mitochondrial membrane potential of cancer cell, suggesting that BA induced cancer cells apoptosis by mitochondrial mediated pathways. Furthermore, BA significantly inhibited the migration and invasion of colorectal cancer cells, reduced the expression of matrix metalloproteinase (MMPs) and increased the expression of MMPs inhibitor (TIMP-2). In addition, the growth of tumor was significantly suppressed by intraperitoneal administration of 20 mg/kg/day of BA in a xenograft tumor mouse model of HCT-116. Histopathological and immunohistochemical analysis showed that MMP-2+ cells and Ki-67+ cells were reduced and cleaved caspase-3+ cells were increased in tumor tissues of mice after BA administration. The results showed that BA not only promoted the apoptosis of colorectal cancer cells, but also inhibited the metastasis of cancer cells. Our results suggest that BA can be a potential natural drug to inhibit the growth and metastasis of colorectal cancer.     

Analysis of the expression and association of retinoblastoma binding protein 6 with the JNK signaling pathway in prostate cancers

This study aims to investigate the expression of retinoblastoma binding protein 6 (RBBP6) in prostate cancer (PCa) and its association with the c‐Jun N‐terminal kinase (JNK) pathway. Immunohistochemistry was used to detect RBBP6 and JNK1/2 expression in PCa and benign prostatic hyperplasia tissues. RBBP6 expression in PCa cells (LNCap, PC3, and DU145) and noncancerous prostate epithelial cells (RWPE‐1) was determined by quantitative real‐time polymerase chain reaction and western blot analysis. PC3 and DU145 cells were transfected with RBBP6 small interfering RNAs (siRNAs) to examine the biological characteristics. Anisomycin (a JNK activator) with/without RBBP6 siRNA was used to treat PC3 cells for further investigating the ramification of the RBBP6‐mediated JNK pathway in PCa. PCa tissues and cells showed higher RBBP6 and JNK1/2 expression. RBBP6 was positively correlated with JNK1/2 in PCa tissues. Besides, RBBP6 expression was correlated to clinical tumor stage, lymph node metastasis, Gleason grade, preoperative prostate‐specific antigen level, as well as prognosis of PCa. RBBP6 siRNA reduced cell proliferation, arrested cells at G2/M, and promoted cell apoptosis, and suppressed JNK pathway. In addition, migration and invasion decreased after the RBBP6 siRNA transfection with downregulated matrix metallopeptidase‐2 (MMP‐2) and MMP‐9. Anisomycin promoted the proliferation, invasion, and migration of PC3 cells and inhibited PC3 cell apoptosis, which could be reversed by RBBP6 siRNA. RBBP6 expression was upregulated in PCa tissues and positively correlated with expression level of JNK1/2. With inhibition of RBBP6 expression, the proliferation, invasion, and migration of PCa cells decreased dramatically, while PC3 cell apoptosis increased appreciably, accompanied by the suppression of the JNK pathway.     

A novel synthetic small molecule YH‐306 suppresses colorectal tumour growth and metastasis via FAK pathway

Cell migration and invasion are key processes in the metastasis of cancer, and suppression of these steps is a promising strategy for cancer therapeutics. The aim of this study was to explore small molecules for treating colorectal cancer (CRC) and to investigate their anti‐metastatic mechanisms. In this study, six CRC cell lines were used. We showed that YH‐306 significantly inhibited the migration and invasion of CRC cells in a dose‐dependent manner. In addition, YH‐306 inhibited cell adhesion and protrusion formation of HCT116 and HT‐29 CRC cells. Moreover, YH‐306 potently suppressed uninhibited proliferation in all six CRC cell lines tested and induced cell apoptosis in four cell lines. Furthermore, YH‐306 inhibited CRC colonization in vitro and suppressed CRC growth in a xenograft mouse model, as well as hepatic/pulmonary metastasis in vivo. YH‐306 suppressed the activation of focal adhesion kinase (FAK), c‐Src, paxillin, and phosphatidylinositol 3‐kinases (PI3K), Rac1 and the expression of matrix metalloproteases (MMP) 2 and MMP9. Meanwhile, YH‐306 also inhibited actin‐related protein (Arp2/3) complex‐mediated actin polymerization. Taken together, YH‐306 is a candidate drug in preventing growth and metastasis of CRC by modulating FAK signalling pathway.