VEGFR-3 and Its Ligand VEGF-C Are Associated with Angiogenesis in Breast Cancer

Recently, monoclonal antibodies against the human vascular endothelial growth factor receptor VEGFR-3 were shown to provide a specific antigenic marker for lymphatic endothelium in various normal tissues. In this study we have investigated the expression of VEGFR-3 and its ligand VEGF-C in normal breast tissue and in breast tumors by immunohistochemistry. VEGFR-3 was weakly expressed in capillaries of normal breast tissue and in fibroadenomas. In intraductal breast carcinomas, VEGFR-3 was prominent in the "necklace" vessels adjacent to the basal lamina of the tumor-filled ducts. VEGF receptor 1 and 2 as well as blood vessel endothelial and basal lamina markers were colocalized with VEGFR-3 in many of these vessels. Antibodies against smooth muscle alpha-actin gave a weak staining of the necklace vessels, suggesting that they were incompletely covered by pericytes/smooth muscle cells. A highly elevated number of VEGFR-3 positive vessels was found in invasive breast cancer in comparison with histologically normal breast tissue (P < 0.0001, the Mann-Whitney test). VEGF-C was located in the cytoplasm of intraductal and invasive cancer cells. The results demonstrate that the expression of VEGFR-3 becomes up-regulated in the endothelium of angiogenic blood vessels in breast cancer. The results also suggest that VEGF-C secreted by the intraductal carcinoma cells acts predominantly as an angiogenic growth factor for blood vessels, although this paracrine signaling network between the cancer cells and the endothelium may also be involved in modifying the permeabilities of both blood and lymphatic vessels and metastasis formation.     

VEGF-D in association with VEGFR-3 promotes nodal metastasis in human invasive lobular breast cancer

We assessed the expression of vascular endothelial growth factors (VEGF-C and VEGF-D) in breast cancer cells and the density of lymph vessels and VEGF receptor-3 (VEGFR-3)-positive vessels in and around the tumor in invasive lobular breast cancer. We found significant correlation between peritumoral lymph vessel density and presence of lymph node metastases (P=.001) and the number of metastatic lymph nodes (P<.001). A significant correlation was detected between tumor cell VEGF-D expression and lymph node status (P=.001) and density of lymphatic vessel endothelial receptor (LYVE)-1-positive vessels (P=.035). VEGFR-3+/VEGF-D+ and VEGFR-3+/VEGF-C+ tumors had a significantly higher number of metastatic lymph nodes than tumors with other staining patterns (P<.001). Tumors positive for neither VEGF-D nor VEGFR-3 had a lower density of LYVE-1+ vessels than tumors with other staining patterns (P=.033). Our results indicate that peritumoral lymph vessel density is associated with lymph node metastases in invasive lobular breast cancer and that invasive lobular cancer producing VEGF-D, surrounded by VEGFR-3+ vessels, has a significantly higher peritumoral lymph vessel density and a higher number of metastatic lymph nodes.     

血管内皮生长因子C及其受体在MNNG诱发的大鼠大肠癌细胞及淋巴管的表达

目的 观察大鼠大肠癌组织内血管内皮生长因子-C(VEGF-C)及其受体3(VEGFR-3)的表达情况,探讨VEGF-C及其受体VEGFR-3在肿瘤淋巴转移中的作用.方法 采用甲基硝基亚硝基胍(MNNG)诱发的大鼠大肠癌模型,应用免疫组织化学(SABC法)技术检测29例大鼠原发性大肠癌组织中VEGF-C及VEGFR-3蛋白,观察VEGF-C及VEGFR-3在大肠癌组织内的表达.结果 正常大肠组织内未见VEGF-C阳性表达,但可见淋巴管内皮细胞VEGFR-3阳性表达.在大肠癌组织内,VEGF-C蛋白表达于癌细胞,早期和中晚期癌的阳性表达率分别是75%和100%,(P＜0.05).VEGFR-3主要表达于淋巴管内皮细胞,早期和中晚期癌组织内淋巴管的阳性表达率分别是58.33%和94.12%(P＜0.05).结论 大鼠大肠癌VEGF-C的表达与肿瘤进展有关,推测VEGF-C通过受体VEGFR-3诱导淋巴管生成:VEGFR-3在淋巴管的阳性表达均随肿瘤进展增高,可能与大肠癌淋巴转移有关.     

VEGFR-3 in adult angiogenesis.

Vascular endothelial growth factor receptor 3 (VEGFR-3, Flt-4), the receptor for vascular endothelial growth factors (VEGFs) C and D, is expressed on lymphatic endothelium and may play a role in lymphangiogenesis. In embryonic life, VEGFR-3 is essential for blood vessel development. The purpose of this study was to investigate whether VEGFR-3 is also involved in blood vessel angiogenesis in the adult. This was studied in human tissues showing angiogenesis and in a model of VEGF-A-induced iris neovascularization in the monkey eye, by the use of immunohistochemistry at the light and electron microscopic level. VEGFR-3 was expressed on endothelium of proliferating blood vessels in tumours. In granulation tissue, staining was observed in the proliferative superficial zone in plump blood vessel sprouts, in the intermediate zone in blood vessels and long lymphatic sprouts, and in the deeper fibrous zone in large lymphatics, in a pattern demonstrating that lymphangiogenesis follows behind blood vessel angiogenesis in granulation tissue formation. At the ultrastructural level, VEGFR-3 was localized in the cytoplasm and on the cell membrane of endothelial cells of sprouting blood vessels and sprouting lymphatics. In monkey eyes injected with VEGF-A, blood vessel sprouts on the anterior iris surface and pre-existing blood vessels in the iris expressed VEGFR-3. In conclusion, these results support a role for VEGFR-3 and its ligands VEGF-C and/or VEGF-D in cell-to-cell signalling in adult blood vessel angiogenesis. The expression of VEGFR-3 in VEGF-A-induced iris neovascularization and in pre-existing blood vessels exposed to VEGF-A suggests that this receptor and possibly its ligands are recruited in VEGF-A-driven angiogenesis.     

直肠腺癌VEGF-C及VEGFR-3的表达与淋巴转移的关系

目的为探讨癌细胞淋巴管转移机理,观察血管内皮生长因子-C(VEGF-C)和血管内皮生长因子受体-3(VEGFR-3)在直肠腺癌组织及淋巴管的表达。方法取人直肠腺癌手术材料30例,用免疫组化方法检测癌区和癌周正常区VEGF-C和VEGFR-3的表达情况。结果VEGF-C主要表达在直肠腺癌的癌细胞胞浆,VEGFR-3主要在淋巴管内皮细胞有阳性表达,两者在癌区的表达率均高于正常区直肠组织;癌区淋巴管的平均面密度(33.81±5.67)高于正常区平均面密度(20.13±3.27)。结论VEGF-C和VEGFR-3在人直肠腺癌中的过表达,可能与淋巴管增生和扩张,促进癌细胞的淋巴转移有关。     

Signaling pathways induced by vascular endothelial growth factor (review)

Vasculogenesis and angiogenesis are the mechanisms responsible for the development of the blood vessels. Angiogenesis refers to the formation of capillaries from pre-existing vessels in the embryo and adult organism, while vasculogenesis is the development of new blood vessels from the differentiation of endothelial precursors (angioblasts) in situ. Vascular endothelial growth factor (VEGF) family members are major mediators of vasculogenesis and angiogenesis both during development and in pathological conditions. VEGF has a variety of effects on vascular endothelium, including the ability to promote endothelial cell viability, mitogenesis, chemotaxis, and vascular permeability. It mediates its activity mainly via two tyrosine kinase receptors, VEGFR-1 (flt-1) and VEGFR-2 (flk-1/KDR), although other receptors, such as neuropilin-1 and -2, can also bind VEGF. Another tyrosine kinase receptor, VEGFR-3 (flt-4) binds VEGF-C and VEGF-D and is more important in the development of lymphatic vessels. While the functional effects of VEGF on endothelial cells has been well studied, not as much is known about VEGF signaling. This review summarizes the different pathways known to be involved in VEGF signal transduction and the biological responses triggered by the VEGF signaling cascade.     

Transgenic induction of vascular endothelial growth factor-C is strongly angiogenic in mouse embryos but leads to persistent lymphatic hyperplasia in adult tissues

Vascular endothelial growth factor-C (VEGF-C) is the quintessential lymphangiogenic growth factor that is required for the development of the lymphatic system and is capable of stimulating lymphangiogenesis in adults by activating its receptor, VEGFR-3. Although VEGF-C is a major candidate molecule for the development of prolymphangiogenic therapy for defective lymphatic vessels in lymphedema, the stability of lymph vessels generated by exogenous VEGF-C administration is not currently known. We studied VEGF-C-stimulated lymphangiogenesis in inducible transgenic mouse models in which growth factor expression can be spatially and temporally controlled without side effects, such as inflammation. VEGF-C induction in adult mouse skin for 1 to 2 weeks caused robust lymphatic hyperplasia that persisted for at least 6 months. VEGF-C induced lymphangiogenesis in numerous tissues and organs when expressed in the vascular endothelium in either neonates or adult mice. Very few or no effects were observed in either blood vessels or collecting lymph vessels. Additionally, VEGF-C stimulated lymphangiogenesis in embryos after the onset of lymphatic vessel development. Strikingly, a strong angiogenic effect was observed after VEGF-C induction in vascular endothelium at any point before embryonic day 16.5. Our results indicate that blood vessels can undergo VEGF-C-induced angiogenesis even after down-regulation of VEGFR-3 in embryos; however, transient VEGF-C expression in adults can induce long-lasting lymphatic hyperplasia with no obvious side effects on the blood vasculature.     

Expression of the Vascular Endothelial Growth Factor C Receptor VEGFR-3 in Lymphatic Endothelium of the Skin and in Vascular Tumors

It is difficult to identify lymph vessels in tissue sections by histochemical staining, and thus a specific marker for lymphatic endothelial cells would be more practical in histopathological diagnostics. Here we have applied a specific antigenic marker for lymphatic endothelial cells in the human skin, the vascular endothelial growth factor receptor-3 (VEGFR-3), and show that it identifies a distinct vessel population both in fetal and adult skin, which has properties of lymphatic vessels. The expression of VEGFR-3 was studied in normal human skin by in situ hybridization, iodinated ligand binding, and immunohistochemistry. A subset of developing vessels expressed the VEGFR-3 mRNA in fetal skin as shown by in situ hybridization and radioiodinated vascular endothelial growth factor (VEGF)-C bound selectively to a subset of vessels in adult skin that had morphological characteristics of lymphatic vessels. Monoclonal antibodies against the extracellular domain of VEGFR-3 stained specifically endothelial cells of dermal lymph vessels, in contrast to PAL-E antibodies, which stained only blood vessel endothelia. In addition, staining for VEGFR-3 was strongly positive in the endothelium of cutaneous lymphangiomatosis, but staining of endothelial cells in cutaneous hemangiomas was weaker. These results establish the utility of anti-VEGFR-3 antibodies in the identification of lymphovascular channels in the skin and in the differential diagnosis of skin lesions involving lymphatic or blood vascular endothelium.     

Expression of vascular endothelial growth factor-C and its receptor in invasive micropapillary carcinoma of the breast

Invasion to lymphatic vessels and metastasis to lymph nodes are frequent complications in invasive micropapillary carcinoma (IMPC) of human breast cancer. Vascular endothelial growth factor-C (VEGF-C) and its receptor, VEGFR-3 have been implicated as the important factors in the formation of lymphatic vessels and recent experimental evidence strongly suggests that lymphangiogenesis in tumor promotes lymphatic metastasis. To clarify the mechanism of its occurrence, the expression of VEGF-C, VEGFR-3 and lymphatic vessel density (LVD) was examined in 40 cases of IMPC (pure and mixed type) and in 40 cases of pseudo-IMPC. Cytoplasmic expression of VEGF-C and VEGFR-3 were more frequent in tumor cells of IMPC compared to those of pseudo-IMPC. A significant positive correlation was found between the expression of VEGF-C and VEGFR-3 in both IMPC and pseudo-IMPC. The expression of VEGF-C was also significantly associated with higher peritumoral LVD, lymphatic invasion and number of lymph node metastasis in IMPC. These findings suggest that VEGF-C promotes the proliferation of peritumoral lymphatic vessels and that lymphatic invasion and metastasis to lymph nodes are frequently induced in IMPC of breast.     

食管癌血管内皮生长因子和受体的表达及在癌转移中的作用

目的观察人食管癌组织和淋巴管中血管内皮生长因子(VEGF-C)及其受体-3(VEGFR-3)的表达,探讨食管癌的淋巴道转移机制。方法取临床手术切除的食管癌组织,用免疫组化方法检测人食管癌早期和进展期癌细胞或淋巴管对VEGF-C及其VEGFR-3的表达情况。结果在食管癌的癌细胞中可见VEGF-C阳性表达,阳性颗粒主要定位于肿瘤细胞胞浆内。淋巴管内皮细胞仅见VEGFR-3阳性表达,VEGFR-3在血管和癌细胞中也存在少量阳性表达。进展期食管癌VEGF-C和VEGFR-3的表达率和表达强度均强于早期。结论食管癌癌细胞VEGF-C的表达和淋巴管内皮细胞上VEGFR-3的表达均与肿瘤进展呈正相关,推测VEGF-C通过受体VEGFR-3促进食管癌组织淋巴管生成,从而引起癌淋巴道转移。     

VEGFR-3与肿瘤淋巴转移的研究进展

肿瘤转移通常是人类癌症致死的主要原因之一.淋巴转移是肿瘤特别是癌的常见转移途径,肿瘤细胞转移至淋巴结通常作为肿瘤转移的信号,同时也是患者预后的重要指标.在肿瘤转移过程中,血管内皮生长因子及其受体家族发挥了重要的作用.尤其是淋巴内皮特异性的受体--血管内皮生长因子受体3(VEGFR-3)及其配体VEGF-C/D在促进淋巴管生长具有关键的作用.本文就VEGFR-3与肿瘤淋巴转移的研究进展进行综述.     

Lymphangiogenic growth factor responsiveness is modulated by postnatal lymphatic vessel maturation

Lymphatic vessel plasticity and stability are of considerable importance when attempting to treat diseases associated with the lymphatic vasculature. Development of lymphatic vessels during embryogenesis is dependent on vascular endothelial growth factor (VEGF)-C but not VEGF-D. Using a recombinant adenovirus encoding a soluble form of their receptor VEGFR-3 (AdVEGFR-3-Ig), we studied lymphatic vessel dependency on VEGF-C and VEGF-D induced VEGFR-3 signaling in postnatal and adult mice. Transduction with AdVEGFR-3-Ig led to regression of lymphatic capillaries and medium-sized lymphatic vessels in mice under 2 weeks of age without affecting collecting lymphatic vessels or the blood vasculature. No effect was observed after this period. The lymphatic capillaries of neonatal mice also regressed partially in response to recombinant VEGFR-3-Ig or blocking antibodies against VEGFR-3, but not to adenovirus-encoded VEGFR-2-Ig. Despite sustained inhibitory VEGFR-3-Ig levels, lymphatic vessel regrowth was observed at 4 weeks of age. Interestingly, whereas transgenic expression of VEGF-C in the skin induced lymphatic hyperplasia even during embryogenesis, similar expression of VEGF-D resulted in lymphangiogenesis predominantly after birth. These results indicate considerable plasticity of lymphatic vessels during the early postnatal period but not thereafter, suggesting that anti-lymphangiogenic therapy can be safely applied in adults.     

Liver metastases arising from well-differentiated pancreatic endocrine neoplasms demonstrate increased VEGF-C expression.

Pancreatic endocrine neoplasms (PENs) are uncommon, generally well-differentiated neoplasms that demonstrate prominent endocrine differentiation. Although the majority of PENs remain localized, malignant spread may occur via lymphatic or hematogenous routes. Angiogenic growth factors, including the vascular endothelial growth factor (VEGF) family, have been implicated in new vessel growth and hematogenous metastases, although this has not been studied in PENs. We therefore examined 19 primary well-differentiated PENs and 7 liver metastases to determine the expression of VEGF-A and its family member VEGF-C by immunolabeling analysis. VEGF-A immunoreactivity was evident only in scattered cells throughout all lesions. VEGF-C, however, demonstrated low-to-moderate expression in primary PENs by semiquantitative histoscore analysis (factor of labeling intensity by percentage of positive cells), with significantly increased expression in liver metastases (mean histoscore indices: primary PEN, 4.7 versus liver metastases, 9.5; Student's t test; P =.002773). Microvascular density of primary PENs and liver metastases did not appear to linearly correlate with VEGF-C expression. Examination of the VEGF-C-specific receptors VEGFR-2/KDR/Flk-1 and VEGFR-3/Flt-4 demonstrated intense endothelial immunoreactivity for VEGFR-2, as well as VEGFR-2 and -3 expression on the majority of neoplastic cells, suggesting a possible role in autocrine/paracrine neoplastic growth regulation. We postulate that the upregulation of VEGF-C may be involved in PEN progression and metastases, although not via a direct proangiogenic mechanism.     

血管内皮生长因子C及其受体3在人恶性黑色素瘤组织内的表达及意义

目的 观察人恶性黑色素瘤组织内血管内皮生长因子C(VEGF-C)及其受体3(VEGFR-3)的表达,探讨VEGF-C和VEGFR-3在恶性黑色素瘤淋巴管生成及淋巴道转移中的作用.方法 取人恶性黑色素瘤组织48例(石蜡标本30例,术后新鲜组织18例),应用免疫组织化学和RT-PCR技术,观察VEGF-C和VEGFR-3蛋白及mRNA在恶性黑色素瘤组织内的表达情况.以淋巴管内皮透明质酸受体(LYVE-1)标记淋巴管,计数恶性黑色素瘤组织淋巴管数密度.结果 VEGF-C和VEGFR-3蛋白主要表达于恶性黑色素瘤细胞胞浆内,在肿瘤周围的血管和淋巴管内皮上也可见VEGFR-3蛋白表达,VEGF-C和VEGFR-3蛋白在淋巴结转移组恶性黑色素瘤组织内的表达水平明显高于无淋巴结转移组(P<0.05).在18例新鲜恶性黑色素瘤中,淋巴结转移组VEGF-C和VEGFR-3mRNA的表达明显高于无淋巴结转移组(P<0.01).LYVE-1表达于肿瘤间质内的淋巴管内皮细胞,淋巴结转移组恶性黑色素瘤组织中的淋巴管数密度(LMVD)为9.845±2.454,无淋巴结转移组恶性黑色素瘤组织中的淋巴管数密度为6.534±2.193,淋巴结转移组恶性黑色素瘤组织内的淋巴管数密度明显高于无淋巴结转移组(P<0.01).结论恶性黑色素瘤组织内VEGF-C表达明显增高,并通过上调其受体VEGFR-3的表达促进恶性黑色素瘤组织内淋巴管的生成,从而促进恶性黑色素瘤的淋巴道转移.     

CD40 ligation induces tissue factor expression in human vascular smooth muscle cells

Vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are important regulators of blood and lymphatic vessel growth and vascular permeability. Both blood and lymphatic vessels of the upper respiratory tract play important roles in pathological conditions, such as infections and tumors. Here we have studied the expression of VEGF-C and its receptor VEGFR-3 in the upper respiratory system by Northern blot analysis and immunohistochemistry of human tissues, and in situ mRNA hybridization of developing mouse embryos and β-galactosidase staining of mouse embryos having a LacZ marker gene in the VEGFR-3 gene locus. The results demonstrate expression of VEGF-C and VEGFR-3 in the developing and adult nasal respiratory epithelium and in the nasal vascular plexus, respectively. Unlike in most other tissues, in the nasal mucosa VEGFR-3 is expressed in both blood and lymphatic vessels. Expression of VEGF-C was also detected in nasal and nasopharyngeal tumor islands, which were surrounded by VEGFR-3-positive angiogenic blood vessels. These results suggest that VEGF-C and VEGFR-3 have a role in the development of the nasal submucosal vascular plexus and in its normal function and that they are associated with angiogenesis in nasal and nasopharyngeal tumors.     

The significance of VEGF-C/VEGFR-2 interaction in the neovascularization and prognosis of nephroblastoma (Wilms' tumour)

AIM: To investigate the immunohistochemical expression of vascular endothelial growth factor (VEGF)-C and VEGFR-2 in nephroblastoma tissue and correlate their presence with the survival rate of children diagnosed with stage III Wilms' tumour. METHODS AND RESULTS: The material included nephroblastoma tissue obtained from 25 children hospitalized in the Department of Paediatric Oncology, Haematology and Transplantology between 1997 and 2003. VEGF-C and VEGFR-2 expression was evaluated by immunohistochemical assay. VEGF-C was expressed in all cells of the blastemal component and in 30% of tumour cells in the stromal part. It was absent from epithelial elements. VEGFR-2 expression was spread over the surface of numerous stromal cells as well as all the epithelial cells forming dysplastic tubules. The blastemal component of Wilms' tumour was VEGFR-2-negative. VEGF-C-immunopositive stromal cells were situated in the closest proximity to VEGF-C-immunonegative but VEGFR-2-immunoreactive tubules. VEGF-C expression was of prognostic value for both clinical progression (P = 0.0005) and tumour-related death (P = 0.0365). CONCLUSIONS: VEGF-C expression in Wilms' tumour constitutes a potent unfavourable risk factor and may direct future antiangiogenic treatment strategies. The proximity of VEGF-C and VEGFR-2 in the stromal and epithelial components of nephroblastoma could be the neoplastic equivalent of the binary VEGF-C function observed in epithelial and endothelial morphogenesis.     

血管内皮生长因子C、D和受体3在人胰腺癌组织中的表达

目的:通过观察不同临床指标的人胰腺癌组织VEGF-C、VEGF-D、VEGFR-3的表达,来探讨VEGF-C和VEGF-D对人胰腺癌转移的影响,为癌组织中淋巴管的生成机制以及癌的淋巴道转移机制提供理论依据。方法:取人胰腺癌标本33例及癌旁正常胰腺组织15例,用免疫组化的方法观察VEGF-C、VEGF-D及VEGFR-3在人胰腺癌和癌旁正常胰腺组织中的表达。结果:VEGF-C、VEGF-D和VEGFR-3在胰腺癌组织中的表达比例较在癌旁正常胰腺组织中的表达比例明显增高,并且VEGFR-3的表达与VEGF-D的表达具有显著相关性(P<0.01),与VEGF-C的表达不具有相关性(P>0.05)。胰腺癌组织中VEGF-C和VEGF-D的表达与患者的年龄、性别、远处转移无关(P>0.05)。结论:VEGF-C、VEGF-D在胰腺癌组织中的表达明显增高,并有可能通过与VEGFR-3的结合促进了癌组织中淋巴管的生成,从而对癌的淋巴道转移起促进作用。     

Localisation of members of the vascular endothelial growth factor (VEGF) family and their receptors in human atherosclerotic arteries

BACKGROUND: Vascular endothelial growth factor (VEGF) mediates endothelial cell mitogenesis and enhances vascular permeability. The existence of single or multiple VEGF isoforms and receptors suggests that these proteins may have overlapping but distinct functions, which may be reflected in their cell expression and distribution. METHODS: The localisation of VEGFs A-C and their receptors (VEGFRs 1-3, respectively) in 30 fresh human atherosclerotic arteries, 15 normal uterine arteries, and 15 saphenous veins using immunohistochemistry and western blotting. RESULTS: Saphenous veins showed no staining for VEGF-B or VEGFR-2. Smooth muscle cells (SMCs) showed the strongest staining for VEGF-A, VEGF-B, VEGFR-1, and VEGFR-2 in all specimens. Conversely, VEGFR-3 and VEGF-C were predominantly localised to the endothelial vasa vasorum in normal arteries, whereas medial SMCs showed the strongest staining in atherosclerotic arteries. Western blotting showed variations in VEGF protein localisation, with lower amounts of VEGF-B and VEGF-C in saphenous veins, compared with arterial tissue. Amounts of VEGF-C were lower than those of VEGF-A and VEGF-B in all specimens. CONCLUSION: This study provides direct evidence of the presence of VEGF proteins and receptors in human physiology and pathology, with variations in both the amounts of VEGF proteins expressed and their cellular distribution in normal arteries compared with atherosclerotic arteries. The presence of VEGFs A-C and their receptors in normal arterial tissue implies that VEGF functions may extend beyond endothelial cell proliferation. Reduced VEGFR-2 staining in atherosclerotic arteries may have implications for the atherosclerosis process and the development of vascular disease and its complications.     

VEGF-C、VEGFR-3和iNOS在人乳腺癌淋巴管的表达

目的检测乳腺癌组织血管内皮生长因子-C(VEGF-C)及其受体(VEGFR-3)、iNOS基因表达的相关性及这三个基因mRNA表达水平与淋巴管密度(LVD)的相关性,为阐明乳腺癌淋巴管生成的分子机理提供实验依据。方法RT-PCR检测乳腺癌组织及正常乳腺组织VEGF-C、VEGFR-3、iNOSmRNA的表达水平;免疫组织化学染色法检测淋巴管内皮细胞上VEGFR-3的表达,测定淋巴管密度。结果乳腺癌LVD为20.35±4.23,显著高于正常对照组(P<0.05);乳腺癌组织VEGF-C、VEGFR-3、iNOSmRNA三者的表达率分别为74.0%、84.0%、82.0%,显著高于正常对照组(P<0.05);VEGF-C、VEGFR-3、iNOS阳性组中LVD分别为21.34±3.45、18.54±4.68、17.43±4.76,显著高于对照组(P<0.05)。结论VEGF-C、VEGFR-3、iNOSmRNA表达与淋巴管密度之间呈正相关,并且3者之间的表达亦具有相关性,这些基因的表达增高可能在乳腺癌淋巴管生成过程中具有重要作用。