Figure 4

Detection of galectin-9 in tissue sections from nasopharyngeal carcinomas and other head and neck carcinomas. Galectin-9 is detected by immunohistochemistry using the 1G3 mab. A) Absence of galectin-9 staining on a section of a paraffin-embedded pellet of BL2 cells(X200). B) Intense albeit heterogenous galectin-9 staining on a section of a paraffin-embedded pellet of REMB1 cells (X100). C) NPC tumor biopsy. (Table 1, patient #2, undifferentiated non-keratinizing) (X100). Intense galectin-9 staining is seen in the nests of malignant cells which are clearly separated from the abundant lymphoid stroma. In addition, a weaker staining is seen in a large number of stromal cells. D) NPC tumor biopsy (Table 1, patient #10, undifferentiated non-keratinizing) (X100). Galectin-9 staining is only seen in spans of epithelial cells which are distinct from the lymphoid stroma. E) NPC tumor biopsy (Table 1, patient #1, undifferentiated non-keratinizing) (X100). Malignant cells are intermingled with infiltrating leucocytes. Galectin-9 is detected in both malignant and infiltrating cells. In contrast, it is completely undetectable in the non-malignant epithelium. F) Oropharynx squamous cell carcinoma (Table 1, patient #13) (X100). Complete absence of galectin-9 staining in malignant cells.