Nuclear to cytoplasmic shift of p33(ING1b) protein from normal oral mucosa to oral squamous cell carcinoma in relation to clinicopathological variables.
OBJECTIVE
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.


METHODS
p33(ING1b) expression was immunohistochemically examined in 20 normal oral mucosa specimens and 49 OSCCs.


RESULTS
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).


CONCLUSIONS
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.
Zhang
Jin-Ting
JT
Department of Stomatology, The First Hospital of Hebei Medical University, Shijiazhuang 050031, Hebei Province, China.
Wang
Da-Wei
DW
Li
Qing-Xing
QX
Zhu
Zhen-Long
ZL
Wang
Ming-Wei
MW
Cui
Dong-Sheng
DS
Yang
Yan-Hong
YH
Gu
Yu-Xin
YX
Sun
Xiao-Feng
XF
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology*; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D005260:Female; D006801:Humans; D000076023:Inhibitor of Growth Protein 1; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000378:metabolism*; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology*; D009687:Nuclear Proteins / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism*