Suppression of type 1 Insulin-like growth factor receptor expression by small interfering RNA inhibits A549 human lung cancer cell invasion in vitro and metastasis in xenograft nude mice

Cancer invasion and metastasis, involving a variety of pathological processes andcytophysiological changes,contribute to the high mortality of lung cancer.The type 1 insulin-like growthfactor receptor (IGF-1R),associated with cancer progression and invasion,is a potential anti-invasion andanti-metastasis target in lung cancer.To inhibit the invasive properties of lung cancer cells,we successfullydown-regulated IGF-1R gene expression in A549 human lung cancer cells by small interfering RNA (siRNA)technology,and evaluated its effects on invasion-related gene expression,tumor cell in vitro invasion,andmetastasis in xenograft nude mice.A549 cells transfected with a plasmid expressing hairpin siRNA forIGF-1R showed a significantly decreased IGF-1R expression at the mRNA level as well as the proteinlevel.In biological assays,transfected A549 cells showed a significant reduction of cell-matrix adhesion,migration and invasion.Consistent with these results,we found that down-regulation of IGR-1Rconcomitantly accompanied by a large reduction in invasion-related gene expressions,including MMP-2,MMP-9,u-PA,and IGF-1R specific downstream p-Akt.Direct tail vein injections of plasmid expressinghairpin siRNA for IGF- 1R significantly inhibited the formation of lung metastases in nude mice.Our resultsshowed the therapeutic potential of siRNA as a method for gene therapy in inhibiting lung cancer invasionand metastasis.     

Alteration in gene expression profile and biological behavior in human lung cancer cell line NL9980 by nm23-H1 gene silencing

Lung cancer is the leading cause of cancer death in both men and women. Tumor metastasis is an essential aspect of lung cancer progression. nm23-H1 is a metastasis suppressor gene. The molecular mechanism by which nm23-H1 suppresses the metastasis is still unclear. Here, we compared the gene expression profile of human large cell lung cancer cell line NL9980 by nm23-H1 gene silencing with that of negative control cells to comprehensively investigate nm23-H1-mediated changes in gene expression of NL9980 cells. Microarray assay revealed that expression of 733-known genes (1.9%, 733/38,500) were altered in response to nm23-H1 gene silencing, including 466 upregulated genes and 267 downregulated. real-time PCR assay of the expression changes indicated that 81.82% (45/55) of verified genes were consistent with that observed in microarray assay. The upregulated genes included MMP-1, -2, SNAI2, CXCL1, 2, 3, PAI-2, while the downregulated genes included cystatin B, TIMP-2, E-cadherin, centrin-2, all of which have been associated with tumor metastasis. Furthermore, we confirmed by Western blot that the expression of MMP-1 and -2 were significantly increased while that of cystatin B was dramatically decreased in NL9980-nm23-H1 silencing cells. The NL9980-nm23-H1 silencing cells exhibited significantly more S phase growth and invasive ability. Thus, silencing of nm23-H1 gene caused metastasis-related gene expression changes in lung cancer cells. The knockdown of nm23-H1 expression may change the lung cancer cells to a more invasive phenotype through alteration in the expression of a set of genes.     

Targeting Insulin-Like Growth Factor 1 Receptor Inhibits Pancreatic Cancer Growth and Metastasis

Pancreatic cancer is one of the most lethal cancers. Increasing incidence and mortality indicates that there is still much lacking in detection and management of the disease. This is partly due to a lack of specific symptoms during early stages of the disease. Several growth factor receptors have been associated with pancreatic cancer. Here, we have investigated if an RNA interference approach targeted to IGF-IR could be effective and efficient against pancreatic cancer growth and metastasis. For that, we evaluated the effects of IGF-1R inhibition using small interfering RNA (siRNAs) on tumor growth and metastasis in HPAC and PANC-1 pancreatic cancer cell lines. We found that silencing IGF-1R inhibits pancreatic cancer growth and metastasis by blocking key signaling pathways such AKT/PI3K, MAPK, JAK/STAT and EMT. Silencing IGF-1R resulted in an anti-proliferative effect in PANC-1 and HPAC pancreatic cancer cell lines. Matrigel invasion, transwell migration and wound healing assays also revealed a role for IGF-1R in metastatic properties of pancreatic cancer. These results were further confirmed using Western blotting analysis of key intermediates involved in proliferation, epithelial mesenchymal transition, migration, and invasion. In addition, soft agar assays showed that silencing IGF-1R also blocks the colony forming capabilities of pancreatic cancer cells in vitro. Western blots, as well as, flow cytometric analysis revealed the induction of apoptosis in IGF-1R silenced cells. Interestingly, silencing IGF-1R also suppressed the expression of insulin receptor β. All these effects together significantly control pancreatic cancer cell growth and metastasis. To conclude, our results demonstrate the significance of IGF-1R in pancreatic cancer.     

MicroRNA-133a Suppresses Multiple Oncogenic Membrane Receptors and Cell Invasion in Non-Small Cell Lung Carcinoma

Non-small cell lung cancers (NSCLCs) cause high mortality worldwide, and the cancer progression can be activated by several genetic events causing receptor dysregulation, including mutation or amplification. MicroRNAs are a group of small non-coding RNA molecules that function in gene silencing and have emerged as the fine-tuning regulators during cancer progression. MiR-133a is known as a key regulator in skeletal and cardiac myogenesis, and it acts as a tumor suppressor in various cancers. This study demonstrates that miR-133a expression negatively correlates with cell invasiveness in both transformed normal bronchial epithelial cells and lung cancer cell lines. The oncogenic receptors in lung cancer cells, including insulin-like growth factor 1 receptor (IGF-1R), TGF-beta receptor type-1 (TGFBR1), and epidermal growth factor receptor (EGFR), are direct targets of miR-133a. MiR-133a can inhibit cell invasiveness and cell growth through suppressing the expressions of IGF-1R, TGFBR1 and EGFR, which then influences the downstream signaling in lung cancer cell lines. The cell invasive ability is suppressed in IGF-1R- and TGFBR1-repressed cells and this phenomenon is mediated through AKT signaling in highly invasive cell lines. In addition, by using the in vivo animal model, we find that ectopically-expressing miR-133a dramatically suppresses the metastatic ability of lung cancer cells. Accordingly, patients with NSCLCs who have higher expression levels of miR-133a have longer survival rates compared with those who have lower miR-133a expression levels. In summary, we identified the tumor suppressor role of miR-133a in lung cancer outcome prognosis, and we demonstrated that it targets several membrane receptors, which generally produce an activating signaling network during the progression of lung cancer.     

Silencing SOX2 Expression by RNA Interference Inhibits Proliferation,Invasion and Metastasis,and Induces Apoptosis through MAP4K4/JNK Signaling Pathway in Human Laryngeal Cancer TU212 Cells

SRY (sex determining region Y)-box 2 (SOX2) plays an important role in tumor cell metastasis and apoptosis. Laryngeal squamous cell carcinoma (LSCC), responsible for 1.5% of all cancers, is one of the most common head and neck malignancies. Accumulating evidence shows that SOX2 is overexpressed in several human tumors, including lung cancer, esophageal carcinoma, pancreatic carcinoma, breast cancer, ovarian carcinoma and glioma. Our study aimed to investigate the silencing effects of SOX2 expression using RNA interference (RNAi) on various biological processes in laryngeal cancer TU212 cells, including proliferation, apoptosis, invasion and metastasis. We also studied the involvement of the MAPK/JNK signaling pathway in the biological effects of SOX2 siRNA in TU212 cells. We found that silencing SOX2 decreased the proliferation, migration, and invasion of TU212 cells, and induced apoptosis. This effect of silencing SOX2 could be reversed by silencing MAP4K4. Therefore, we consider SOX2 as a key regulator of the upstream MAP4K4/JNK signaling pathways that could be a potential therapeutic target in the treatment of patients with or prevention of laryngeal cancer.     

Proprotein convertases regulate insulin-like growth factor 1-induced membrane-type 1 matrix metalloproteinase in VSMCs via endoproteolytic activation of the insulin-like growth factor-1 receptor

The IGF-1 receptor (IGF-1R) and MT1-MMP are synthesized as larger precursor proproteins, which require endoproteolytic activation by the proprotein convertases (PCs) furin/PC5 to gain full biological activity. The aim of this study was to investigate the contribution of PCs to IGF-1R and/or MT1-MMP activation in vascular smooth muscle cells (VSMCs) as well as VSMC proliferation/migration, which are key elements in vascular remodeling. Furin and PC5 mRNAs and proteins were found in VSMCs. Inhibition of furin-like PCs with the specific pharmacological inhibitor dec-CMK inhibited IGF-1R endoproteolytic activation. Inhibition of IGF-1R maturation abrogated IGF-induced IGF-1R autophosphorylation, PI3-kinase and MAPK induction, as well as VSMC proliferation (p<0.05 vs. controls), whereas it had no effect of PDGF-stimulated signaling pathways or cell growth. Both, IGF-1 and PDGF-BB, induced MT1-MMP expression, but only IGF-1-mediated MT1-MMP induction was inhibited by dec-CMK. Induction of MMP-2 by IGF-1 was inhibited by the PI3-kinase inhibitor wortmannin, but not by the MEK-inhibitor PD98059. Dec-CMK inhibited VSMC chemotaxis comparable to the effects of the MMP-inhibitor GM6001 (both p<0.05 vs. controls), supporting that MMPs are involved. In conclusion, this study demonstrates that targeting furin-like PCs and thus inhibiting IGF-1R activation is a novel target to inhibit IGF-1-mediated signaling and cell functions, such as IGF-1-induced MT1-MMP/MMP-2 in VSMCs.     

Lung CSC-derived exosomal miR-210-3p contributes to a pro-metastatic phenotype in lung cancer by targeting FGFRL1

Lung cancer has the highest mortality rate among human cancers, and the majority of deaths can be attributed to metastatic spread. Lung cancer stem cells (CSCs) are a component of the tumour microenvironment that contributes to this process. Exosomes are small membrane vesicles secreted by all types of cells that mediate cell interactions, including cancer metastasis. Here, we show that lung CSC-derived exosomes promote the migration and invasion of lung cancer cells, up-regulate expression levels of N-cadherin, vimentin, MMP-9 and MMP-1, and down-regulate E-cadherin expression. Moreover, we verified that these exosomes contribute to a pro-metastatic phenotype in lung cancer cells via miR-210-3p transfer. The results of bioinformatics analysis and dual-luciferase reporter assays further indicated that miR-210-3p may bind to fibroblast growth factor receptor-like 1 (FGFRL1); silencing FGFRL1 enhanced the metastatic ability of lung cancer cells, whereas overexpressing FGFRL1 suppressed metastasis. Taken together, our results provide new insights into a potential molecular mechanism whereby lung CSC-derived exosomal miR-210-3p targets FGFRL1 to promote lung cancer metastasis. FGFRL1 may be a promising therapeutic target in lung cancer.     

The matrix metalloproteinase-9 regulates the insulin-like growth factor-triggered autocrine response in DU-145 carcinoma cells

The androgen-independent human prostate adenocarcinoma cell line DU-145 proliferates in serum-free medium and produces insulin-like growth factors (IGF)-I, IGF-II, and the IGF type-1 receptor (IGF-1R). They also secrete three IGF-binding proteins (IGFBP), IGFBP-2, -3, and -4. Of these, immunoblot analysis revealed selective proteolysis of IGFBP-3, yielding fragments of 31 and 19 kDa. By using an anti-IGF-I-specific monoclonal antibody (mAb), we detect surface receptor-bound IGF-I on serum-starved DU-145 cells, which activates IGF-1R and triggers a mitogenic signal. Incubation of DU-145 cells with blocking anti-IGF-I, anti-IGF-II, or anti-IGF-I plus anti-IGF-II mAb does not, however, inhibit serum-free growth of DU-145. Conversely, anti-IGF-1R mAb and IGFBP-3 inhibit DNA synthesis. IGFBP-3 also modifies the DU-145 cell cycle, decreases p34(cdc2) levels, and IGF-1R autophosphorylation. The antiproliferative IGFBP-3 activity is not IGF-independent, since des-(1-3)IGF-I, which does not bind to IGFBP-3, reverses its inhibitory effect. DU-145 also secretes the matrix metalloproteinase (MMP)-9, which can be detected in both a soluble and a membrane-bound form. Matrix metalloproteinase inhibitors, but not serpins, abrogate DNA synthesis in DU-145 associated with the blocking of IGFBP-3 proteolysis. Overexpression of an antisense cDNA for MMP-9 inhibits 80% of DU-145 cell proliferation that can be reversed by IGF-I in a dose-dependent manner. Inhibition of MMP-9 expression is also associated with a decrease in IGFBP-3 proteolysis and with reduced signaling through the IGF-1R. Our data indicate an IGF autocrine loop operating in DU-145 cells, specifically modulated by IGFBP-3, whose activity may in turn be regulated by IGFBP-3 proteases such as MMP-9.     

海参多糖抑制人肾癌细胞A498的生长转移作用机制

肾细胞癌(RCC)是最常见的恶性癌之一,癌症转移是目前导致肾癌患者死亡的主要原因之一。MMP-9被发现在许多具有侵袭性和转移能力的人类癌症中过表达,其表达和分泌受到NF-κB调控;VEGF在维持原发性癌和转移瘤生长所需的血管生成中发挥重要作用,其表达也受到活化的NF-κB调节。海参的多种活性物质在抗氧化、抗菌和抗癌方面都有出色的作用,而抗癌的主要机制则包括诱导癌细胞凋亡、抑制癌细胞生长、减少癌细胞转移等。本研究通过利用不同浓度的海参多糖处理人肾癌细胞A498,采用MTT细胞增殖实验、粘附实验、迁移实验和小室侵袭实验,研究了海参多糖对A498细胞的生长转移的影响;采用蛋白印记法检测了海参多糖对A498细胞内MMP-9、NF-κBp65和VEGF表达水平的影响。结果表明,海参多糖能够显著抑制A498细胞的增殖活力、粘附能力、迁移能力和侵袭能力,并且全都表现出明显的剂量依赖性;中浓度(100μg/mL)和高浓度(200μg/mL)的海参多糖能够显著下调A498细胞内MMP-9、NF-κBp65和VEGF的表达。这些结果说明海参多糖能有效抑制人肾癌细胞A498的生长、转移和侵袭,可能的机制是通过抑制NF-κB信号通路下调MMP-9和VEGF的表达,从而发挥抗癌细胞转移的作用。     

CK2 inhibitor CX4945 induces sequential inactivation of proteins in the signaling pathways related with cell migration and suppresses metastasis of A549 human lung cancer cells

Casein kinase 2 (CK2) is known to be involved in various cellular processes such as cell cycle, apoptosis and proliferation. It has been reported that the inhibition of CK2 induced by recently developed small molecule CX4945 shows anti-cancer effects including anti-proliferation and anti-angiogenesis in several different cancers including prostate cancer. Here we report that migration and invasion of A549 human lung cancer cells are suppressed by the inhibition of CK2 induced by CX4945. We found that CX4945 sequentially attenuates the proteins in PI3K/Akt and MAPK pathways, two signaling pathways related with cell migration. This sequential control of signal pathways inhibits the expression of membrane type 1-matrix metalloproteinase and this leads to the selective attenuation of one of the gelatinases, MMP-2, which can degrade components of extracellular matrix, and metastasis of A549 human lung cancer cell.     

Lycopene inhibits matrix metalloproteinase-9 expression and down-regulates the binding activity of nuclear factor-kappa B and stimulatory protein-1

The carotenoid lycopene has been associated with decreased risks of several types of cancer, such as hepatoma. Although lycopene has been shown to inhibit metastasis, its mechanism of action is poorly understood. Here, we used SK-Hep-1 cells (from a human hepatoma) to test whether lycopene exerts its anti-invasion activity via down-regulation of the expression of matrix metalloproteinase (MMP)-9, an important enzyme in the degradation of basement membrane in cancer invasion. The activity and expressions of MMP-9 protein and mRNA were detected by gelatin zymography, Western blotting and RT-PCR, respectively. The binding abilities of nuclear factor-kappa B (NF-kappaB), activator protein-1 and stimulatory protein-1 (Sp1) to the binding sites in the MMP-9 promoter were measured by the electrophoretic mobility shift assay. We showed that lycopene (1-10 microM) significantly inhibited SK-Hep-1 invasion (P<.05) and that this effect correlated with the inhibition of MMP-9 at the levels of enzyme activity (r(2)=.94, P<.001), protein expression (r(2)=.80, P=.007) and mRNA expression (r(2)=.94, P<.001). Lycopene also significantly inhibited the binding abilities of NF-kappaB and Sp1 and decreased, to some extent, the expression of insulin-like growth factor-1 receptor (IGF-1R) and the intracellular level of reactive oxygen species (P<.05). The antioxidant effect of lycopene appeared to play a minor role in its inhibition of MMP-9 and invasion activity of SK-Hep-1 cells because coincubation of cells with lycopene plus hydrogen peroxide abolished the antioxidant effect but did not significantly affect the anti-invasion ability of lycopene. Thus, lycopene decreases the invasive ability of SK-Hep-1 cells by inhibiting MMP-9 expression and suppressing the binding activity of NF-kappaB and Sp1. These effects of lycopene may be related to the down-regulation of IGF-1R, while the antioxidant activity of lycopene appears to play a minor role.     

弱碱性消癌液抑制乳腺癌细胞生长、转移并介导其消亡

为了研究新的肿瘤治疗方法,设计了1种弱碱性消癌液（weak alkaline cancer-eliminating liquid,WACEL）,测试WACEL是否抑制癌细胞的生长转移及消亡.在体外,检测WACEL对3种细胞株,即子宫颈鳞癌细胞SiHa、非小细胞肺鳞癌细胞H1299、人乳腺癌细胞MDA-MB-231的生长增殖、细胞周期、细胞凋亡、侵袭转移的影响. 在体内,建立人乳腺癌裸鼠颈背皮下移植瘤模型,观察WACEL对裸鼠皮下肿瘤生长转移的作用. 研究结果发现,WACEL明显抑制3种细胞系的生长增殖,G2/M期细胞增多,出现G2/M期阻滞,阻止细胞周期的进程. 细胞形态呈圆状,细胞核浓缩,caspase-3活性检测增加,线粒体的膜电位降低,细胞凋亡;活细胞数目减少,细胞膜破裂,发生消亡现象,癌细胞迁移明显减少（P﹤0.001）.目标基因SCCA1、cyclinB1、MMP-2以及MMP-9 的mRNA表达水平下调,caspase-3的mRNA表达水平上调;SCCA1、cyclinB1和MMP-2蛋白表达下调,caspase-3蛋白表达上调.体内动物实验发现,处理组的肿瘤生长较对照组明显缓慢,肺组织HE染色未见明显癌细胞转移,而对照组可见癌细胞转移. WACEL能抑制乳腺癌细胞的生长、转移并介导其消亡.本研究系统分析WACEL与癌细胞本身及其pH微环境之间的相互作用机制,发现其改变癌细胞所处的微环境的重要性.     

沉默FOXQ1可逆转SW480细胞的上皮-间质转化

FOXQ1是FOX家族的的重要成员之一,其参与了多种人类肿瘤的上皮间质转化(epithelial- mesenchymal transition,EMT).本研究设计合成了FOXQ1基因的shRNA（short hairpin RNA）,用此转染SW480细胞,通过显微镜观察细胞形态,Transwell小室、细胞黏附试验检测转移能力及黏附能力,以探索FOXQ1与结直肠癌细胞EMT的关系.结果显示,沉默FOXQ1后,SW480细胞顶底极性及细胞间紧密连接增加,侵袭、迁移的细胞数目减少,同种黏附能力增加,异种黏附能力降低.进一步的机制研究表明,沉默FOXQ1基因可以导致SW480细胞的上皮标志因子E-cadherin表达显著增高,而间质细胞标志因子N-cadherin、Vimentin及MMP2表达均降低.以上结果表明,沉默FOXQ1基因可以逆转SW480细胞EMT,其机制可能与E-cadherin的上调和N cadherin、Vimentin、MMP2的下调有关,这为进一步研究FOXQ1在结直肠癌发生发展中的作用提供实验基础.     

Disruption of the protein interaction between FAK and IGF-1R inhibits melanoma tumor growth

FAK (focal adhesion kinase) and IGF-1R (insulin-like growth factor receptor-1) directly interact with each other and thereby activate crucial signaling pathways that benefit cancer cells. Inhibition of FAK and IGF-1R function has been shown to significantly decrease cancer cell proliferation and increase sensitivity to chemotherapy and radiation treatment. As a novel approach in human melanoma, we evaluated the effect of a small-molecule compound that disrupts the protein interaction of FAK and IGF-1R.

Previously, using virtual screening and functional testing, we identified a lead compound (INT2–31) that targets the known FAK-IGF-1R protein interaction site. We studied the ability of this compound to disrupt FAK-IGF-1R protein interactions, inhibit downstream signaling, decrease human melanoma cell proliferation, alter cell cycle progression, induce apoptosis and decrease tumor growth in vivo.

INT2–31 blocked the interaction of FAK and IGF-1R in vitro and in vivo in melanoma cells and tumor xenografts through precluding the activation of IRS-1, leading to reduced phosphorylation of AKT upon IGF-1 stimulation. As a result, INT2–31 significantly inhibited cell proliferation and viability (range 0.05–10 μM). More importantly, 15 mg/kg of INT2–31 given for 21 d via intraperitoneal injection disrupted the interaction of FAK and IGF-1R and effectively decreased phosphorylation of tumor AKT, resulting in significant melanoma tumor regression in vivo.

Our data suggest that the FAK-IGF-1R protein interaction is an important target, and disruption of this interaction with a novel small molecule (INT2–31) has potential anti-neoplastic therapeutic effects in human melanoma.     

Disruption of the protein interaction between FAK and IGF-1R inhibits melanoma tumor growth

FAK (focal adhesion kinase) and IGF-1R (insulin-like growth factor receptor-1) directly interact with each other and thereby activate crucial signaling pathways that benefit cancer cells. Inhibition of FAK and IGF-1R function has been shown to significantly decrease cancer cell proliferation and increase sensitivity to chemotherapy and radiation treatment. As a novel approach in human melanoma, we evaluated the effect of a small-molecule compound that disrupts the protein interaction of FAK and IGF-1R. Previously, using virtual screening and functional testing, we identified a lead compound (INT2–31) that targets the known FAK-IGF-1R protein interaction site. We studied the ability of this compound to disrupt FAK-IGF-1R protein interactions, inhibit downstream signaling, decrease human melanoma cell proliferation, alter cell cycle progression, induce apoptosis and decrease tumor growth in vivo. INT2–31 blocked the interaction of FAK and IGF-1R in vitro and in vivo in melanoma cells and tumor xenografts through precluding the activation of IRS-1, leading to reduced phosphorylation of AKT upon IGF-1 stimulation. As a result, INT2–31 significantly inhibited cell proliferation and viability (range 0.05–10 μM). More importantly, 15 mg/kg of INT2–31 given for 21 d via intraperitoneal injection disrupted the interaction of FAK and IGF-1R and effectively decreased phosphorylation of tumor AKT, resulting in significant melanoma tumor regression in vivo. Our data suggest that the FAK-IGF-1R protein interaction is an important target, and disruption of this interaction with a novel small molecule (INT2–31) has potential anti-neoplastic therapeutic effects in human melanoma.     

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

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

CBX4 promotes the proliferation and metastasis via regulating BMI‐1 in lung cancer

Proliferation and metastasis are significantly malignant characteristics of human lung cancer, but the underlying molecular mechanisms are poorly understood. Chromobox 4 (CBX4), a member of the Polycomb group (PcG) family of epigenetic regulatory factors, enhances cellular proliferation and promotes cancer cell migration. However, the effect of CBX4 in the progression of lung cancer is not fully understood. We found that CBX4 is highly expressed in lung tumours compared with adjacent normal tissues. Overexpression of CBX4 significantly promotes cell proliferation and migration in human lung cancer cell lines. The knockdown of CBX4 obviously suppresses the cell growth and migration of human lung cancer cells in vitro. Also, the proliferation and metastasis in vivo are blocked by CBX4 knockdown. Furthermore, CBX4 knockdown effectively arrests cell cycle at the G0/G1 phase through suppressing the expression of CDK2 and Cyclin E and decreases the formation of filopodia through suppressing MMP2, MMP9 and CXCR4. Additionally, CBX4 promotes proliferation and metastasis via regulating the expression of BMI‐1 which is a significant regulator of proliferation and migration in lung cancer cells. Taken together, these data suggest that CBX4 is not only a novel prognostic marker but also may be a potential therapeutic target in lung cancer.     

miR-195通过下调IGF-1R的表达抑制胶质母细胞瘤的增殖和迁移

目的:探讨miR-195对胶质母细胞瘤(Glioblastoma,GBM)增殖和迁移的影响,并阐明其分子调控机制。方法:采用qRT-PCR检测不同级别胶质瘤中miR-195的表达。将miR-195转染至胶质瘤U251细胞后,应用qRT-PCR验证转染效率,MTT及划痕实验检测U251细胞的增殖及迁移能力的改变,qRT-PCR及Western blot检测胰岛素样生长因子1受体(Insulin-like growth factor 1receptor, IGF-1R)的mRNA和蛋白表达;利用质粒转染过表达miR-195后,同时过表达IGF-1R,再应用MTT及划痕实验检测U251细胞的增殖及迁移能力的变化。结果:随着胶质瘤级别的增加,miR-195的表达逐渐降低,各级别胶质瘤中miR-195的表达差异有统计学意义(P0.05)。体外转染miR-195至U251细胞24、48、72 h后,转染组细胞活力和迁移能力均较对照组显著降低(P0.05),细胞中IGF-1R的mRNA和蛋白的表达也明显减少(P0.05);通过转染IGF-1R过表达质粒可显著逆转miR-195过表达对U251细胞增殖及迁移的抑制作用。结论:miR-195可能通过下调IGF-1R的表达,进而抑制胶质母细胞瘤的增殖和迁移。     

Downregulation of microRNA-92b-3p suppresses proliferation,migration, and invasion of gastric cancer SGC-7901 cells by targeting Homeobox D10

To investigate the effect and mechanism of microRNA-92b-3p (miR-92b-3p) targeting Homeobox D10 (HOXD10) on proliferation, migration, and invasion of gastric cancer, we detected t he expression of miR-92b-3p and HOXD10 in SGC-7901 cells. The effects of miR-92b-3p or HOXD10 on proliferation, migration, invasion, and matrix metalloproteinase (MMP)-2/9 expression in SGC-7901 cells were measured by the Cell Counting Kit-8 assay, Transwell assay, and Western blot, respectively. The results showed that miR-92b-3p expression was increased, and HOXD10 expression was decreased in SGC-7901 cells, compared with human normal gastric epithelial cells GES-1. Functional experiments demonstrated that cell proliferation, migration, invasion, and expression of MMP-2/9 in SGC-7901 cells were significantly inhibited by miR-92b-3p silencing and HOXD10 overexpression. Moreover, HOXD10 was a potential target gene of miR-92b-3p as evidenced by the TargetScan software and double luciferase reporter assay. In the rescue experiment, knockdown of HOXD10, accompanied by higher expression of MMP-2/9, could significantly eliminate the inhibitory effects of miR-92b-3p silencing on cell proliferation, migration, and invasion. In conclusion, miR-92b-3p is highly expressed in gastric cancer SGC-7901 cells, and interfering with its expression might inhibit SGC-7901 cell proliferation, migration, and invasion via downregulating MMP-2/9 expression and targeting HOXD10.     

RKIP inhibits the migration and invasion of human prostate cancer PC-3M cells through regulation of extracellular matrix

Raf kinase inhibitor protein (RKIP) plays a pivotal role in several intracellular signaling cascades and has been implicated as a metastasis suppressor in multiple cancer cells including prostate cancer cells, but the mechanism is not very clear. In this study, we investigated the effect of RKIP on cell proliferation, migration and invasion using human prostate cancer PC-3M cells as a model system. Our results indicate that RKIP does not effect cell proliferation in PC-3M cells, but inhibits both cell migration and cell invasion. In association with this inhibitory effect, RKIP down-regulates matrix metalloproteinases (MMP-2 and MMP-9), cathepsin B and urinary plasminogen activator (uPA). Also RKIP has the ability to regulate the expression of E-cadherin. But ectopic expression of RKIP does not affect the level of the Snail protein. As it has been indicated here, RKIP inhibits the migration and invasion ability of human prostate cancer cells through regulation of the extracellular matrix. These findings provide new mechanistic insight how RKIP suppresses metastasis in vitro.