GNG2 inhibits invasion of human malignant melanoma cells with decreased FAK activity

It is well known that heterotrimeric G protein is composed of a Gα-subunit and a Gβγ-dimer and promotes cancer characteristics. Our recent study showed reduced G protein γ2 subunit (Gng2/GNG2) expression levels in malignant melanoma cells compared with those in benign melanocytic cells in both mice and humans. Our recent study also showed that reduced GNG2 alone augmented proliferation of malignant melanoma cells. To our knowledge, however, there is no evidence showing an effect of Gng2/GNG2 alone on metastasis of any cancers including malignant melanoma. In his study, we first prepared GNG2-overexpressed SK-Mel28 human malignant melanoma cells, in which GNG2 protein expression level was undetectably low. Migration and invasion activities of the GNG2-overexpressed malignant melanoma cells were suppressed up to 1/10th, with decreased activity of focal adhesion kinase (FAK). We then found that the expression level of GNG2 in A375M, a highly metastatic cell line, was significantly lower than that in A375P, the parental cell line of A375M. We finally showed that knockdown of GNG2 alone in A375P cells enhanced migration and invasion with increased FAK activity. Taken together, our results suggest that overexpression of GNG2 alone inhibits metastasis in human malignant melanoma cells with decreased FAK activity. Thus, GNG2 might be a candidate of molecular targets of prevention and therapy for metastasis of malignant melanoma.     

Local environmental influences on uveal melanoma: vitreous humor promotes uveal melanoma invasion, whereas the aqueous can be inhibitory

BACKGROUND: Uveal melanomas of the choroid and ciliary body are aggressive tumors causing the death of approximately 50% of patients. In contrast, iris melanomas only infrequently metastasize; why these differences exist is not known. The local environment can regulate cancer growth and development, and it is probable the aqueous and vitreous humors have an important role in regulating uveal melanoma behavior. METHODS: To explore this possibility cultures of uveal melanoma were exposed to aqueous and vitreous and the effects investigated using invasion and proliferation assays. ChemiArrays (Chemicon International, Temecula, Calif) were performed to determine which regulatory factors might influence the process. RESULTS: The vitreous universally promoted uveal melanoma invasion, whereas the aqueous mainly had no effect or was inhibitory. Tumor location, and the baseline invasion of the melanoma, affected the ability of aqueous and vitreous from different patients to regulate invasive behavior. Proliferation was not significantly altered as a result of exposure to the aqueous or vitreous. The ability of the humors to regulate uveal melanomas may involve TIMP-2, TIMP-3, and TGF-beta2, as high expression was found by ChemiArray analysis and there were differences in the levels of the regulators in the aqueous compared with the vitreous. CONCLUSIONS: The findings suggest that in situ uveal melanoma development reflects an interaction between the tumor and the environment of the eye. Exposure to the aqueous would therefore contribute to the benign nature of iris melanomas, whereas potential interaction with the vitreous appears to promote the aggressive behavior of posterior uveal melanomas.     

Suppression of invasive behavior of melanoma cells by stable expression of anti-sense perlecan cDNA

Background: Heparan sulfate proteoglycans are one of the major componentsof extracellular matrix and are secreted at different levels by severalnormal and tumoral cells. Perlecan, the basement membrane proteoglycan, hasstructural domains involved in cell/matrix interactions and growth factorstorage. Metastatic melanoma cells show an increase in perlecan expressionas compared to low metastatic ones. We examined whether reduction ofperlecan expression could down-modulate the malignant phenotype in melanomaclones.Materials and methods: We transfected B16-F10 murine malignant melanomacells with a perlecan antisense cDNA construct and tested the in vitrobehavior of the selected clones.Results: The expression of antisense mRNA corresponded to a reduction ofperlecan synthesis. The clones with reduced perlecan synthesis showed adown-regulation of proliferation and invasion.Conclusions: These results further indicate the importance of perlecan asa regulator of growth factor activity affecting the biological properties ofmetastatic cells, and suggest the potential use of antisense perlecan DNA inanti-melanoma gene therapy approaches.     

Gene expression profiles of human melanoma cells with different invasive potential reveal TSPAN8 as a novel mediator of invasion

Background:

Metastatic melanoma requires early detection, being treatment resistant. However, the earliest events of melanoma metastasis, and especially of dermal invasion, remain ill defined.

Results and methods:

Gene expression profiles of two clonal subpopulations, selected from the same human melanoma cell line, but differing in ability to cross the dermal–epidermal junction in skin reconstructs, were compared by oligonucleotide microarray. Of 26 496 cDNA probes, 461 were differentially expressed (>2-fold; P< 0.001), only 71 genes being upregulated in invasive cells. Among them, TSPAN8, a tetraspanin not yet described in melanoma, was upregulated at mRNA and protein levels in melanoma cells from the invasive clone, as assessed by RT–PCR, flow cytometry and western blot analysis. Interestingly, TSPAN8 was the only tetraspanin in which overexpression correlated with invasive phenotype. Flow cytometry of well-defined melanoma cell lines confirmed that TSPAN8 was exclusively expressed by invasive, but not non-invasive melanoma cells or normal melanocytes. Immunohistochemistry revealed that TSPAN8 was expressed by melanoma cells in primary melanomas and metastases, but not epidermal cells in healthy skin. The functional role of TSPAN8 was demonstrated by silencing endogenous TSPAN8 with siRNA, reducing invasive outgrowth from tumour spheroids within matrigel without affecting cell proliferation or survival.

Conclusion:

TSPAN8 expression may enable melanoma cells to cross the cutaneous basement membrane, leading to dermal invasion and progression to metastasis. TSPAN8 could be a promising target in early detection and treatment of melanoma.     

CXCR1 and CXCR2 enhances human melanoma tumourigenesis, growth and invasion

The aggressiveness of malignant melanoma is associated with differential expression of CXCL-8 and its receptors, CXCR1 and CXCR2. However, the precise functional role of these receptors in melanoma progression remains unclear. In this study, we investigate the precise functional role of CXCR1 and CXCR2 in melanoma progression. CXCR1 or CXCR2 were stably overexpressed in human melanoma cell lines, SBC-2 (non-tumourigenic) and A375P (low-tumourigenic) exhibiting low endogenous expression of receptors. Functional assays were performed to study the resulting changes in cell proliferation, motility and invasion, and in vivo tumour growth using a mouse xenograft model. Our data demonstrated that CXCR1- or CXCR2-overexpressing SBC-2 and A375P melanoma cells had enhanced proliferation, chemotaxis and invasiveness in vitro. Interestingly, CXCR1 or CXCR2 overexpression in SBC-2 cells induced tumourigenicity, and A375P cells significantly enhanced tumour growth as examined in vivo. Immunohistochemical analyses showed significantly increased tumour cell proliferation and microvessel density and reduced apoptosis in tumours generated from CXCR1- or CXCR2-overexpressing melanoma cells. CXCR1- or CXCR2-induced modulation of melanoma cell proliferation and migration was observed to be mediated through the activation of ERK1/2 phosphorylation. Together, these studies demonstrate that CXCR1 and CXCR2 play essential role in growth, survival, motility and invasion of human melanoma.     

Linc00961在恶性黑素瘤中表达及其对细胞侵袭及转移的影响

目的:检测潜在长链非编码RNA Linc00961在恶性黑素瘤组织及细胞中的表达,及其对恶性黑素瘤A375细胞迁移和侵袭能力的影响。方法:采用聚合酶链式反应方法检测恶性黑素瘤组织及细胞中Linc00961的表达水平;分析Linc00961在不同TNM分期恶性黑素瘤组织中的表达;构建Linc00961过表达慢病毒质粒上调A375细胞中Linc00961表达,细胞划痕实验检测Linc00961对A375细胞迁移距离的影响,Transwell实验检测Linc00961对A375细胞迁移侵袭的影响。结果:Linc00961在恶性黑素瘤组织及A375细胞中的表达低于良性痣及正常黑素HEMa-LP细胞。TNM IV期恶性黑素瘤组织中的Linc00961表达水平显著低于TNM I、II、III期。过表达A375细胞中Linc00961后,细胞迁移距离降低,细胞迁移及侵袭数目减少（P<0.05）。结论:Linc00961在恶性黑素瘤组织及细胞中低表达,并可抑制恶性黑素瘤细胞迁移及侵袭。     

Reduced WNT5A signaling in melanoma cells favors an amoeboid mode of invasion

Tumor cells invade and spread via either a mesenchymal or an amoeboid mode of migration. Amoeboid tumor cells have a rounded morphology and pronounced RhoA activity. Here, we investigate how WNT5A signaling, a tumor promotor in melanoma, relates to Rho GTPase activity and amoeboid migration. We compared melanoma cells with low (HTB63 cells) and high (WM852 cells) WNT5A expression. HTB63 cells exhibited an amoeboid morphology and had higher RhoA activity but lower invasiveness than WM852 cells in a three‐dimensional (3D) collagen matrix. We next explored the relationships between WNT5A, morphology, and invasive behavior. WNT5A knockdown impaired Rho GTPase Cdc42 activity, resulting in reduced invasion of amoeboid and mesenchymal melanoma cells. Interestingly, knockdown of WNT5A or inhibition of its secretion in WM852 cells expressing wild‐type BRAF also led to increased RhoA activity via decreased RND3 expression, resulting in predominantly amoeboid morphology. In contrast, such treatments had the opposite effects on RND3 expression and RhoA activity in HTB63 cells expressing the active BRAF^V600 mutation. However, treatment of HTB63 cells with a BRAF inhibitor made them respond to WNT5A knockdown in a similar manner as WM852 cells expressing wild‐type BRAF. We next found that dual targeting of WNT5A and RhoA more effectively reduced melanoma cell invasion than targeting either protein individually. Taken together, our results suggest that low WNT5A signaling in melanoma cells promotes a rounded amoeboid type of invasion, which quite likely serves as a compensatory response to decreased WNT5A/Cdc42‐driven invasion. This phenomenon partially explains the enduring melanoma cell invasion observed after impaired WNT5A signaling and has therapeutic implications. Our results suggest that dual targeting of WNT5A and RhoA signaling is a more effective strategy for controlling the invasion of BRAF wild‐type and BRAF^V600 mutated melanomas treated with a BRAF inhibitor than targeting either of the proteins individually.     

缺氧能引起EMT的发生促进乳腺癌的侵袭和迁移

 目的　探讨缺氧对人类乳腺癌细胞MCF-7上皮-间质转化（ EMT）标志分子E-钙黏着素（E-cadherin）、波型蛋白（Vimentin）及侵袭迁移能力的影响,揭示缺氧引起乳腺癌侵袭转移的机制, 为临床治疗乳腺癌提供实验及理论依据。方法　采用Western blot检测低氧诱导因子-1α（HIF-1α）、E-cadherin、Vimentin的变化;四甲基偶氮唑蓝（MTT）法检测缺氧对人类乳腺癌细胞MCF-7黏附能力的影响;Transwell侵袭小室法检测缺氧对MCF-7细胞侵袭和迁移能力的影响。结果　随着缺氧时间的延长,人类乳腺癌细胞中E-cadherin表达明显降低（0.09±0.02）（t＝30.98,P＝0.0007）,Vimentin表达明显升高（0.69±0.04）（t＝915,P＝0.0000) ;缺氧72 h组MCF-7细胞黏附（81.23±0.74）（t＝82.05,P＝0.000）、侵袭（120±6） （t＝22.78,P＝0.0009）和迁移能力明显增强（190±6）（t＝23.49,P＝0.000）。结论　缺氧能下调E-cadherin、上调Vimentin而引起EMT的发生,促进MCF-7细胞黏附、侵袭和迁移。     

Granulocyte, granulocyte-macrophage, and macrophage colony-stimulating factors can stimulate the invasive capacity of human lung cancer cells.

We and other researchers have previously found that colony-stimulating factors (CSFs), which generally include granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF), promote invasion by lung cancer cells. In the present study, we studied the effects of these CSFs on gelatinase production, urokinase plasminogen activator (uPA) production and their activity in human lung cancer cells. Gelatin zymographs of conditioned media derived from human lung adenocarcinoma cell lines revealed two major bands of gelatinase activity at 68 and 92 kDa, which were characterized as matrix metalloproteinase (MMP)-2 and MMP-9 respectively. Treatment with CSFs increased the 68- and 92-kDa activity and converted some of a 92-kDa proenzyme to an 82-kDa enzyme that was consistent with an active form of the MMP-9. Plasminogen activator zymographs of the conditioned media from the cancer cells showed that CSF treatment resulted in an increase in a 48-55 kDa plasminogen-dependent gelatinolytic activity that was characterized as human uPA. The conditioned medium from the cancer cells treated with CSFs stimulated the conversion of plasminogen to plasmin, providing a direct demonstration of the ability of enhanced uPA to increase plasmin-dependent proteolysis. The enhanced invasive behaviour of the cancer cells stimulated by CSFs was well correlated with the increase in MMPs and uPA activities. These data suggest that the enhanced production of extracellular matrix-degrading proteinases by the cancer cells in response to CSF treatment may represent a biochemical mechanism which promotes the invasive behaviour of the cancer cells.     

Heregulin-induced activation of ErbB3 by EGFR tyrosine kinase activity promotes tumor growth and metastasis in melanoma cells

ErbB3 receptor tyrosine kinase has been shown to induce tumor progression in several types of cancer through heterodimerization with ErbB2. However, the role of ErbB3 and its ligand heregulin (HRG) in tumor metastasis remains poorly understood. In the present study, we tried to clarify their contributions to the metastasis of ErbB3-overexpressing B16-BL6 melanoma cells. Stimulation with HRG induced phosphorylation of ErbB3 and metastatic properties including MMP-9 expression, invasion, adhesion and experimental lung metastasis in vivo. These cellular responses were blocked by inhibiting the tyrosine kinase activity of EGFR with PD153035. In addition, phosphorylation of EGFR was rapidly induced by HRG, suggesting that EGFR is a possible heterodimeric counterpart of ErbB3. RNA interference demonstrated that subcutaneous tumor growth and angiogenesis was attenuated by inactivation of ErbB3 in cancer cells. Although experimental pulmonary metastasis was not affected by the knockdown of ErbB3, spontaneous metastasis was, even when primary tumors in the foot pad were amputated at a similar size. These results indicate that HRG-induced activation of ErbB3 via EGFR promotes tumor growth and metastasis of melanoma cells.     

Gene products which play a role in cancer invasion and metastasis

Summary Invasion requires a number of distinct tumor cell interactions with host tissue, beginning with attachment to the matrix, followed by hydrolysis of matrix material and locomotion. Gene products which may be involved in these steps are discussed here. Laminin receptors and integrins have roles in the adhesion phase, while certain collagenases are prominent among the matrix-degrading enzymes. Autocrine motility factors, distinct from growth factors, appear to be involved in tumor cell locomotion. Finally, certain oncogenes, partricularly of theras family, are closely related with metastatic potential. A detailed understanding of the molecular biology of invasion and metastasis could ultimately lead to specific means of interfering with or even reversing these malignant processes.     

下调胰岛素样生长因子-1表达对人胃癌细胞增殖和侵袭及迁移的影响

目的 胰岛素样生长因子1(insulin like growth factor-1,IGF-1)作为体内重要的促有丝分裂原分子,可能与恶性肿瘤的转化及转移相关,但是目前有关IGF-1的表达与胃癌细胞迁移、侵袭的研究较少.本研究旨在研究IGF-1在胃癌组织中的表达,并探讨其表达对人胃癌HGC-27细胞体外增殖及侵袭、迁移能力的影响.方法 检测承德医学院附属医院2014-05-10-2016-05-10胃癌手术切除78例胃癌组织、30例癌旁正常组织及体外不同胃癌细胞系中IGF-1的表达情况.针对IGF-1基因序列,设计发夹RNA(short-hairpin RNA,shRNA)干扰序列并构建干扰载体,转染胃癌HGC-27细胞.荧光实时定量PCR及蛋白质印迹技术分别检测转染干扰载体后HGC-27细胞中IGF-1的表达情况.细胞增殖-毒性检测试剂盒(cell counting kit 8,CCK-8)、划痕实验及Transwell侵袭实验分别检测下调IGF-1对体外细胞HGC-27增殖及迁移、侵袭能力的影响.结果 免疫组织化学法检测显示,低分化胃癌组织中IGF-1阳性表达率为76％(29/38),高、中分化为53％(21/40),癌旁正常组织为27％(8/30).不同胃癌组织与癌旁组织中IGF-1的表达差异有统计学意义,x2=16.66,P＜0.01.并且其表达与胃癌的病理分期(x2=7.430,P=0.007)、组织分化(x2=4.618,P=0.032)等病理因素相关.体外不同胃癌细胞系中IGF-1均呈现高表达,但差异无统计学意义.利用干扰载体能够有效下调胃癌细胞HGC-27中IGF-1在mRNA及蛋白质水平的表达.与空载体转染对照组和野生型HGC-27细胞比较,IGF-1表达下调明显抑制胃癌细胞的体外增殖和侵袭、迁移能力.结论 IGF 1在体内胃癌组织及体外胃癌细胞中高表达,下调IGF-1的表达能够抑制人胃癌细胞HGC-27的增殖及体外侵袭、迁移能力.     

Phosphorylation of ectopically expressed L-plastin enhances invasiveness of human melanoma cells

The leukocyte specific actin-binding protein L-plastin is aberrantly expressed in several nonhematopoetic malignant tumors. However, little is known about the functional consequences of L-plastin expression. Here, we investigated the function of L-plastin in human malignant melanoma cells. Knock-down of endogenous L-plastin by siRNA treatment reduced migration of the melanoma cell line IF6. However, in melanoma patients, no correlation existed between L-plastin expression and tumor stages. This implied that additional factors such as phosphorylation of L-plastin may influence its function in tumor cells. To investigate this further, EGFP-tagged wild-type L-plastin (wt-LPL-EGFP) and a mutated, nonphosphorylatable L-plastin protein (5A7A-LPL-EGFP), were expressed in the L-plastin negative melanoma cell line MV3. Biochemical analysis revealed that wt-LPL-EGFP is phosphorylated in MV3 cells while 5A7A-LPL-EGFP is not. Although both wt-LPL-EGFP and 5A7A-LPL-EGFP were targeted to, and promote the formation of, vinculin-containing adhesion sites, static adhesion to either Matrigel or isolated extracellular matrix molecules was neither influenced by expression of wt-LPL-EGFP nor by expression of 5A7A-LPL-EGFP when compared with EGFP expressing control cells. In contrast, haptotactic, but not chemotactic, migration of melanoma cells towards either Matrigel or isolated extracellular matrix molecules was similarly enhanced, if either 5A7A-LPL-EGFP or wt-LPL-EGFP were expressed in MV3 cells. Interestingly, only cells expressing the phosphorylatable wt-LPL-EGFP protein showed enhanced invasion into Matrigel. In line with these findings the in vivo metastatic capacity of mouse B16 melanoma cells correlates with expression and phosphorylation of L-plastin. These data show that an increase in melanoma cell invasiveness requires not only expression but also phosphorylation of L-plastin.     

lncRNA LOC572558对恶性黑素瘤细胞增殖及侵袭的影响

目的:探讨长链非编码RNA（long non-coding RNA,lncRNA）LOC572558对恶性黑素瘤细胞增殖、迁移及侵袭能力的影响。方法:使用定量实时聚合酶链式反应（qRT-PCR）检测LOC572558在20对恶性黑素瘤及癌旁组织中以及在NHEM、A375、A2058和B16细胞系中的表达。应用小干扰 RNA（siRNA）技术下调 LOC572558表达后,在A375和B16细胞系中使用流式细胞术评估细胞凋亡情况,划痕实验检测细胞的迁移能力,Transwell小室法检测细胞的侵袭能力。结果:lncRNA LOC572558在恶性黑素瘤组织及细胞系中高表达,且下调lncRNA LOC572558表达可以促进A375和B16细胞的凋亡,抑制A375和B16细胞的迁移及侵袭能力。结论:lncRNA LOC572558有望成为临床早期诊断恶性黑素瘤潜在分子标志物以及治疗晚期恶性黑素瘤的靶向标志物。     

Expression of epithelial cadherin and cavernous sinus invasion in human pituitary adenomas

Pituitary adenomas generally are regarded as benign tumors,although some invade the cavernous sinus and recur.We examined the epithelial cadherin (E-CD) expression in30 pituitary adenomas (6 with cavernous sinus invasionand 24 without). Immunoreactivity of E-CD were foundin all pituitary adenomas but they were veryvarious. The presence of an association between E-CDexpression and cavernous sinus invasion was assessed. Therewere no significant differences in E-CD expression betweeninvasive and noninvasive adenomas. These results suggest thatE-CD expression is not associated with cavernous sinusinvasion in pituitary adenomas.     

Expression and function of CD9 in melanoma cells

CD9, a member of the tetraspanin family, functions as an organizer in “tetraspanin webs,” through interacting with other cell adhesion molecules. It plays a role in differentiation, fertilization, and cell migration. We investigated the expression and function of CD9 in melanoma. CD9 protein expression in B16 mouse melanoma and six human melanoma cell lines was decreased compared to normal melanocytes. B16F1 clones stably overexpressing CD9 had reduced ability to form colonies in soft agar; however, paradoxically these overexpressing clones had increased ability to invade Matrigel. Similarly, transient overexpression of CD9 in the human metastatic melanoma cell line WM9 dramatically decreased anchorage‐independent growth, while transient overexpression of CD9 in the radial growth phase cell line SbCl2 resulted in the gain of Matrigel invasion activity. DNA sequencing of CD9 cDNA from all six human melanoma cell lines did not show deletions, insertions, or mutations. Treatment of all six human melanoma cell lines with the histone deacetylase inhibitor trichostatin A increased CD9 levels. The DNA methylation inhibitor 5‐aza‐cytidine also increased CD9 protein levels with greater increases seen in cell lines derived from more malignant melanomas. © 2009 Wiley‐Liss, Inc.     

Growth factor-independent proliferation of rat mammary carcinoma cells by autocrine secretion of neu-differentiation factor/heregulin and transforming growth factor-α

Serially transplantable rat mammary tumor (RMT) cells are not dependent on exogenous epidermal growth factor (EGF) and insulin-like growth factor-I for continuous growth in serum-free medium. Previously, we found that conditioned medium obtained from these cells contained EGF-like mitogenic activity and stimulated tyrosine phosphorylation of a 185-kDa protein in EGF-dependent mammary epithelial cells. This protein is distinct from the EGF receptor and resembles a 185-kDa tyrosine-phosphorylated protein present in RMT cells themselves. The results of the studies reported here indicate that the tyrosine-phosphorylated p185 detected in growth factor-independent RMT cells and in human mammary epithelial cells exposed to RMT-conditioned medium was activated erbB-2 protein. Partial purification of the activating factor present in RMT-conditioned medium yielded a heparin-binding growth factor with biochemical properties similar to those of neu differentiation factor/heregulin (NDF/HRG). RNA-polymerase chain reaction analysis demonstrated that RMT cells expressed mRNA for NDF/HRG, and western-blot analysis confirmed the presence of the 45-kDa secreted form of NDF/HRG in conditioned medium from the growth factor-independent RMT cells. The biological activity of partially purified rat NDF/HRG was examined and found to be the same as that of the pure growth factor. In addition, we found that RMT-conditioned medium, fractionated on an anion-exchange column and by reverse-phase high-pressure liquid chromatography, contained a potent EGF-like growth factor that was distinct from NDF/HRG. This factor competes with ¹²⁵I-EGF for binding to EGF receptors and has an apparent molecular mass of 6600 Da. This factor copurifies by high-pressure liquid chromotography with pure transforming growth factor-α (TGF-α), and the cells are positive for TGF-α mRNA. Thus, growth factor-independent RMT cells also synthesize and secrete TGF-α. These results indicate that growth factor-independent RMT cells secrete two growth factors with overlapping biological activities and suggest that autocrine loops mediated by these factors are important in the growth factor-independent proliferation of the RMT cells. © 1996 Wiley-Liss, Inc.     

siRNA对人结肠癌细胞黏附力和侵袭性的抑制作用

目的: 探讨VEGFR3对人结肠癌细胞黏附力和侵袭性的影响。方法:构建携靶向 VEGFR3基因siRNA(small interfering RNA)表达载体，转染人结肠癌LoVo细胞， 半定量RTPCR和Western blotting检测转染前后LoVo细胞VEGFR3mRNA和蛋白表达的变化，基质黏附实验检测细胞转染后的黏附能力，细胞侵袭实验检测转染后肿瘤细胞侵袭性的改变。结果:携靶向 VEGFR3 基因siRNA的表达载体成功构建，RTPCR检测转染siRNA后LoVo细胞 VEGFR3mRNA表达水平降低；Western blotting检测转染siRNA后72 h LoVo细胞VEGFR3蛋白表达下降，其表达相对值由(1.26±0.19)降至(0.39±012)(P<0.05)。转染siRNA 72 h后LoVo细胞的黏附能力显著下降\[（0.626±0.047）vs (0.407±0.029), P＜0.05\]；LoVo细胞穿膜细胞数(6.38±3.25)明显低于空白对照组(24.82±3.44)、非特异性对照组(23.58±3.73) (P＜0.05)。结论:siRNA能够在LoVo细胞中引发RNA干扰效应，下调VEGFR3基因的表达，进而抑制LoVo细胞的黏附能力和侵袭性。