Neuchrist Csilla, Erovic Bohan M, Handisurya Allesandra, Fischer Michael B, Steiner Georg E, Hollemann David, Gedlicka Claudia, Saaristo A, Burian Martin
Univ. Klinik fuer Hals-Nasen und Ohrenheilkunde, Allgemeines Krankenhaus der Stadt Wien, Waehringer Guertel 18-20, 1090 Wien, Austria.
Head Neck. 2003 Jun;25(6):464-74. doi: 10.1002/hed.10235.
VEGF proteins and their receptors are involved in tumor vessel neoformation. The third VEGF receptor, VEGFR3 (flt-4) is important during both blood vessel development and lymphatic vessel formation. Because HNSCC preferentially metastasizes to regional lymph nodes, we investigated the expression of VEGFR3 and its ligand VEGF-C in head and neck squamous cell carcinomas by semiquantitative RT-PCR (4 HNSCC cells lines and 6 HNSCC specimens) and by immunohistochemistry (18 HNSCC specimens). VEGFR3 protein expression was confirmed by Western blotting in four HNSCC cell lines and six HNSCC specimens.
Semiquantitative mRNA analysis showed VEGF-C mRNA expression in three (SCC9, SCC25, LFFR) of four HNSCC cell lines and all six HNSCC specimens. VEGFR3 mRNA was found in two HNSCC cell lines (JPPA and SCC25) and only weakly detected in the other two HNSCC cell lines (SCC9 and LFFR). High amounts of VEGFR3 mRNA were shown in all six patients' tumor specimens. VEGFR3 Western blot analysis yielded a distinct band at the predicted size of 210 kD in JPPA and SCC9 and hardly detectable bands in SCC25 and LFFR cell lines. All six HNSCC specimens displayed strong VEGFR3 protein bands. Immunohistochemistry in 18 HNSCC specimens assigned strong to mediate VEGF-C IR and minor VEGFR3 IR to tumor cells and strong VEGF-C and VEGFR3 IR to tumor surrounding vessels. In addition, intense VEGF-C immunostaining was observed on perivascular and mononuclear cells in the tumor surrounding stroma. Subtyping of VEGFR3+ microvascular tumor vessels revealed partially double immunolabeling with CD34 and flk-1, indicating a common origin of blood and lymphatic vessels. The expression of VEGF-C on tumor cells could be correlated with recurrences, and larger primary tumors had more VEGF-C-positive vessels.
The broad expression of VEGF C and VEGFR3 in HNSCC suggests involvement in tumor lymph angiogenesis and vascular angiogenesis, promoting tumor growth and propagation of cancer cells. This implies that inhibitors of lymph angiogenesis could become effective therapeutic options similar to classical angiogenesis inhibitors.
血管内皮生长因子（VEGF）蛋白及其受体参与肿瘤血管的新生。第三种VEGF受体，即VEGFR3（flt - 4）在血管发育和淋巴管形成过程中均起重要作用。由于头颈部鳞状细胞癌（HNSCC）优先转移至区域淋巴结，我们通过半定量逆转录聚合酶链反应（RT - PCR，检测4种HNSCC细胞系和6份HNSCC标本）及免疫组织化学方法（检测18份HNSCC标本），研究了VEGFR3及其配体VEGF - C在头颈部鳞状细胞癌中的表达情况。通过蛋白质免疫印迹法在4种HNSCC细胞系和6份HNSCC标本中证实了VEGFR3蛋白的表达。
半定量mRNA分析显示，4种HNSCC细胞系中的3种（SCC9、SCC25、LFFR）及所有6份HNSCC标本均有VEGF - C mRNA表达。在2种HNSCC细胞系（JPPA和SCC25）中发现有VEGFR3 mRNA，而在另外2种HNSCC细胞系（SCC9和LFFR）中仅微弱检测到。所有6例患者的肿瘤标本中均显示有大量的VEGFR3 mRNA。蛋白质免疫印迹分析显示，在JPPA和SCC9细胞系中，VEGFR3在预测的210 kD大小处出现明显条带，而在SCC25和LFFR细胞系中几乎检测不到条带。所有6份HNSCC标本均显示有较强的VEGFR3蛋白条带。对18份HNSCC标本进行免疫组织化学检测发现，肿瘤细胞对VEGF - C免疫反应（IR）强，对VEGFR3 IR弱，而肿瘤周围血管对VEGF - C和VEGFR3 IR均强。此外，在肿瘤周围基质的血管周围细胞和单核细胞上观察到强烈的VEGF - C免疫染色。对VEGFR3 + 微血管肿瘤血管进行亚型分析发现，部分与CD34和flk - 1呈双重免疫标记，表明血管和淋巴管有共同起源。肿瘤细胞上VEGF - C的表达与复发相关，且较大的原发性肿瘤有更多VEGF - C阳性血管。
VEGF - C和VEGFR3在HNSCC中的广泛表达提示其参与肿瘤淋巴血管生成和血管生成，促进肿瘤生长及癌细胞的扩散。这意味着淋巴血管生成抑制剂可能成为与经典血管生成抑制剂类似的有效治疗选择。
