Nuclear to cytoplasmic shift of p33ING1b protein from normal oral mucosa to oral squamous cell carcinoma in relation to clinicopathological variables

• DOI: 10.1007/s00432-007-0305-y
• Publication Date: 2007-09-05T08:53:10Z
• Authors: Jin-Ting Zhang; Da-Wei Wang; Qing-Xing Li; Zhen-Long Zhu; Ming-Wei Wang; Dong-Sheng Cui; Yan-Hong Yang; Yu-Xin Gu; Xiao-Feng Sun
• Keywords: Adult; Cell Nucleus; Male; Cytoplasm; Tumor Suppressor Proteins; Intracellular Signaling Peptides and Proteins; Mouth Mucosa; Nuclear Proteins; Middle Aged; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; Carcinoma, Squamous Cell; Humans; Female; Mouth Neoplasms; Inhibitor of Growth Protein 1; Aged

p33(ING1b), as a candidate tumour suppressor gene, has been found to be expressed a proportion of oral squamous cell carcinomas (OSCCs), however, its clinicopathological significance is not studied yet. Our aim was to investigate association of p33(ING1b) expression with clinicopathological variables and particularly interesting new cysteine-histidine rich protein (PINCH) in OSCCs.p33(ING1b) expression was immunohistochemically examined in 20 normal oral mucosa specimens and 49 OSCCs.Normal squamous cells showed only p33(ING1b )nuclear expression (no cytoplasmic expression), with a rate of 90% positive cases. While 24% of OSCCs appeared cytoplasmic expression (11 of them with weak nuclear staining) and the rest tumours (76%) were negative for p33(ING1b). Furthermore, the cases having lymph node metastasis showed a higher frequency of positive cytoplasmic expression than those without metastasis (P = 0.03). The p33(ING1b) cytoplasmic expression was positively related to PINCH expression (P = 0.04), the cases positive for both proteins had a high rate of the metastasis (P = 0.03).The transfer of p33(ING1b) protein from the nucleus to the cytoplasm may result in loss of normal cellular function of the protein, which might play a role in the tumourigenesis and metastasis of OSCCs.