The retinoic acid receptor-beta (RAR-beta) mRNA expression in the oral squamous cell carcinoma associated with betel quid use.
BACKGROUND
Within the abundant retinoids nuclear receptors, abnormally low expression of the RAR-beta has been shown to contribute to neoplastic progression in oral epithelium in western countries. Distinctly different risk factors contributing to oral squamous cell carcinoma (OSCC) in epidemiologically different societies denote the value of exploring the role of RAR-beta expression in OSCC associated with betel quid (BQ) use in our society.


METHODS
We examined the cellular expression of RAR-beta using in situ hybridization (ISH) analysis on 38 pairs of surgical specimens of primary OSCC and non-cancerous matched tissues (NCMT) to correlate with their clinico-pathological features including age, sites of tumor, habit of BQ use, stage, size of primary tumor, lymph node metastasis, differentiation.


RESULTS
Of all cases analyzed, BQ users were significantly younger than non-BQ users (51.2 +/- 2.1 vs. 60.2 +/- 2.6, P = 0.01). 52% OSCC of BQ users (13/25) and 23% OSCC of non-BQ users (3/13) exhibited the absence of RAR-beta expression. In 17 paired-samples from buccal mucosa (BM), most NCMT and less than half of OSCC exhibited RAR-beta expression (16/17, 94% vs. 8/17, 47%, P = 0.003). The RAR-beta expression was seen in the vast majority of the well-differentiated OSCC and in less than half of the moderately differentiated OSCC only (15/20, 75% vs. 7/18, 39%, P = 0.03).


CONCLUSIONS
A correlation between the loss of RAR-beta expression and more advanced histopathological grade tumors was observed. This study also suggests that the loss of RAR-beta expression is significant in BM OSCC, which preferentially occurs in BQ users.
Kao
Shou-Yen
SY
Department of Dentistry, Oral Maxillofacial Surgery, Veterans General Hospital-Taipei/School of Dentistry, National Yang-Ming University, Taipei, Taiwan, R.O.C.
Tu
Hsi-Feng
HF
Chang
Kuo-Wei
KW
Chang
Che-Shoa
CS
Yang
Cheng-Chei
CC
Lin
Shu-Chun
SC
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001114:Areca / Q000009:adverse effects*; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000473:pathology* / Q000556:secondary; D016022:Case-Control Studies; D003124:Colorimetry; D004396:Coloring Agents; D005260:Female; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D017403:In Situ Hybridization; D008207:Lymphatic Metastasis / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000378:metabolism / Q000473:pathology; D009062:Mouth Neoplasms / Q000235:genetics / Q000473:pathology*; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics; D018168:Receptors, Retinoic Acid / Q000032:analysis* / Q000235:genetics; D012907:Smoking / Q000009:adverse effects; D013223:Statistics as Topic; D016019:Survival Analysis
D004396:Coloring Agents; D015347:RNA Probes; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; C082925:retinoic acid receptor beta