O‐GlcNAcylation in oral squamous cell carcinoma

• Published in: Journal of oral pathology & medicine Vol. 47; no. 3; pp. 260 - 267
• Main Authors: Kongkaew, Tassaporn, Aung, Win Pa Pa, Supanchart, Chayarop, Makeudom, Anupong, Langsa‐ard, Sarawat, Sastraruji, Thanapat, Chaiyarit, Ponlatham, Krisanaprakornkit, Suttichai
• Format: Journal Article
• Language: English
• Published: Denmark Wiley Subscription Services, Inc 01.03.2018
• Subjects: Adult; Aged; Aged, 80 and over; Akt; AKT protein; Carcinoma, Squamous Cell - metabolism; Dentistry; Epidermal growth factor; epidermal growth factor receptor; Epidermal growth factor receptors; Female; Glycosylation; Humans; Immunohistochemistry; Keratinocytes; Keratinocytes - metabolism; Kinases; Lysates; Male; Middle Aged; Mouth Neoplasms - metabolism; N-Acetylglucosamine; N-Acetylglucosaminyltransferases - metabolism; O-GlcNAcylation; Oral cancer; Oral squamous cell carcinoma; O‐GlcNAc transferase; Paraffin; Phosphorylation; Receptor, Epidermal Growth Factor - metabolism; Squamous cell carcinoma; Translation; O-GlcNAcylation; oral squamous cell carcinoma; O-GlcNAc transferase; Akt; epidermal growth factor receptor
• ISSN: 0904-2512; 1600-0714
• DOI: 10.1111/jop.12680

Background Two post‐translational mechanisms commonly demonstrated in various cancers are protein phosphorylation and glycosylation by O‐linked β‐N‐acetylglucosamine (O‐GlcNAc). However, only phosphorylation of the epidermal growth factor receptor (EGFR)/Akt pathway has been reported in oral squamous cell carcinoma (OSCC). Therefore, we aimed to determine both post‐translational modifications in OSCC tissues and in oral cancer cells compared to normal tissues and oral keratinocytes and to find correlations of these modifications with histological grading. Methods Thirty‐two OSCC and ten normal formalin‐fixed and paraffin‐embedded sections were probed with the anti‐O‐GlcNAc, anti‐O‐GlcNAc transferase (OGT), anti‐phosphorylated‐EGFRtyr1173, and anti‐phosphorylated‐Aktser473 antibodies following standard immunohistochemistry. The immunohistochemical (IHC) score was determined using the Fromowitz standard. Whole cell lysates of oral cancer cells and normal oral keratinocytes were immunoblotted with the anti‐O‐GlcNAc antibody. Results The median IHC scores of O‐GlcNAc or OGT between OSCC and normal tissues were not different, whereas those of phosphorylated‐EGFRtyr1173 and phosphorylated‐Aktser473 were significantly higher in OSCC than normal tissues (P < .001 and P < .01, respectively). Similarly, expression of O‐GlcNAcylated proteins in oral cancer cells and normal oral keratinocytes did not differ. In the OSCC group, the median IHC scores of O‐GlcNAc and OGT were significantly lower than those of phosphorylated‐EGFRtyr1173 and phosphorylated‐Aktser473 (P < .01 and P < .001, respectively). The IHC scores of O‐GlcNAc or OGT were not determined to correlate with histological grading. Conclusion Unlike other types of cancers, our findings demonstrate that the levels of O‐GlcNAcylation are not significantly increased in OSCC tissues or in oral cancer cells and are not associated with the histological grading of OSCC.