Korean J Otolaryngol-Head Neck Surg.  2000 Jun;43(6):631-637.

Expression of p53, PCNA, EGFR in Rat Submandibular Gland Tumor Induced Experimentally

• Yoo YS
• Seo M
• Woo HY
• Lee CH
• Choi JH

Abstract

BACKGROUND AND IBJECTIVES: Animal models of cancer are frequently used in many studies. In this study, we tried to make a model of SMG cancer using rats. We used SMG tissues from rats for the analysis of expression of p53, PCNA and EGFR
MATERIALS AND METHODS
Pellets of 4-6 mg DMBA were implanted into the submandibular glands of 47 female Sprague- Dawley rats which were sacrificed at 4, 8, 10, 14, and 18 weeks after DMBA implantation. Thirteen rats were sacrificed at the beginning of experiment and were used as a control group. Histopathological and immunohistochemical staining for p53, PCNA and EGFR were carried out using tissues From rat submandibular glands (SMGs).
RESULTS
Histopathological features during carcinogenesis were as follows : 1) Well differentiated squamous cell carcinomas (SCCs) were first developed at the 8th week of the experiment. 2) In 2 out of 12 cases, fibrosarcoma and SCC were induced simultaneously at the 18th week of experiment. P53-positive nuclei were not observed in this experiment. PCNA-positive nuclei were mainly confined to the basal cells of' the morphologically altered ducts at the 4th week of experiment, Squamous metaplastic cells and well differentiated SCCs showed strong reactivity to PCNA. The PCNA index was about 40% in the tumour incduced group. PCNA indices were 28.8%, 48.1%, 44.6% and 37.8% at the 4th, 10th, 14th and 18th week of the experiment, respectively. In the control group, PCNA index was 6.1%. Increase of PCNA index in the experimental groups was statistically significant compared with control group. The staining intensity for EGFR increased along with the duration of exposure to DMBA.
CONCLUSION
SCC: model of rat SMGs could be developed successfully by implantation of DMBA. In this model, p53 mutation does not seeem to play any important role during carcinogenesis. PCNA and EGFR seem to be closely related to carcinogenesis of SMGs in this model.

Keyword

Submandibular gland; DMRA; p53; PCNA; EGF; Receptor; Squamous cell; Carcinoma

MeSH Terms

9,10-Dimethyl-1,2-benzanthracene
Animals
Carcinogenesis
Carcinoma, Squamous Cell
Epidermal Growth Factor
Female
Fibrosarcoma
Humans
Models, Animal
Proliferating Cell Nuclear Antigen*
Rats*
Submandibular Gland*
9,10-Dimethyl-1,2-benzanthracene
Epidermal Growth Factor
Proliferating Cell Nuclear Antigen