Galectin-3 Upregulation during Tumor Progression in Head and Neck Cancers

Objectives/Hypothesis: To examine the level of expression of galectin-3 in relation to neoplastic progression of hypopharyngeal squamous cell carcinomas (HSCCs) and laryngeal squamous cell carcinomas (LSCCs). Study Design: Retrospective study. Methods: Using a polyclonal antibody against galectin-3 without cross-reactivity to other galectins, we analyzed the presence of galectin-3 using quantitative immunohistochemistry in i) a series of 79 HSCCs compared with 16 normal epithelia, 20 low-grade dysplasia (Low_D) and 25 high-grade dysplasia (High_D) and in ii) a series of 58 LSCCs compared with 34 normal epithelia, 12 Low_D, and 18 High_D. In parallel, galectin-3 expression was studied using Western blotting on a series of 19 fresh biopsies from patients presenting a head and neck tumor. Results: Western blotting excluded a notable degree of proteolytic truncation of galectin-3 in situ. Immunohistochemical galectin-3 positivity expressed as percentage of cells was significantly higher in LSCCs and HSCCs than in Low_D (P = .01) or High_D (P = .0002), respectively. Increased expression of galectin-3 in HSCCs was accompanied by a shift from the cytoplasmic compartment to the nucleus (P = .007). In intertumor-type comparison, laryngeal carcinomas presented nuclear presence of galectin-3 only rarely (1 of 58 cases in laryngeal cancer vs. 27 of 79 cases in hypopharyngeal cancer, P = .00006) and a comparatively low labeling index (P <10-6). Conclusions: Our data reveal an association between level of presence of galectin-3 and neoplastic progression of HSCCs and LSCCs.