Insulin-like growth factor-1 induces lymphangiogenesis and facilitates lymphatic metastasis in colorectal cancer

Figure 1 Immunohistochemical staining of insulin-like growth factor-1 and insulin-like growth factor-1 receptor in colorectal cancer tissues. A: Tumor-adjacent normal tissues; B: Moderately differentiated CRC and C, poorly differentiated CRC (× 200). IGF-1: Insulin-like growth factor-1. IGF-I R: Insulin-like growth factor-1 receptor; CRC: Colorectal cancer.

Figure 2 Morphological features of D2-40 positive lymphatic vessels in colorectal cancer. A: Tumor-adjacent normal tissues; B and C: Colorectal cancer tissues (× 200). Lymphatic vessel invasion of tumor cells was also detected in B and C (black arrow). IGF-1: Insulin-like growth factor-1.

Figure 3 Effect of insulin-like growth factor-1 on the migration and invasion of LoVo cells after 48 h treatment. A: Cell migration; B: Cell invasion (× 200). IGF-1: Insulin-like growth factor-1.

Figure 4 Effect of insulin-like growth factor-1 on lymphatic vessel density in LoVo cell xenografts in nude mice after treatment with insulin-like growth factor-1. A: Control group; B: 50 μg/kg IGF-1 group (× 200). IGF-1: Insulin-like growth factor-1; IGF-I R: Insulin-like growth factor-1 receptor.