Development of a rat model by 3,4-benzopyrene intra-pulmonary injection and evaluation of the effect of green tea drinking on p53 and bcl-2 expression in lung carcinoma.

Abstract

BACKGROUND:

A convenient animal model of primary lung cancer is compelling for investigation into the disease mechanisms and for development of therapeutic strategies. This study aims to develop a reproducible rat model for lung carcinoma by intra-pulmonary injection of 3,4-benzopyrene, and to evaluate the preventive effect of green tea on the formation of lung carcinoma.

METHODS:

Sprague-Dawley rats of the same ages were randomly assigned into three groups treated differently. Rats in group one were given green tea in drinking water (tea concentration: 1.2%; tea polyphenols in the tea solution: 0.3%); rats in the groups two and three were given blank drinking water. Rats in the groups one and two were injected intra-pulmonarily with 3,4-benzopyrene dissolved in corn oil (2 mg/0.2 mL/injection, fortnightly, 4 times in all); rats in the group three were injected with the vehicle corn oil as the control for injection. All the rats were sacrificed one year after the first intra-pulmonary injection. Tumors developed in rats and lung tissues were collected for carcinoma diagnosis and for p53 and bcl-2 expression.

RESULTS:

Intra-pulmonary injection of 3,4-benzopyrene steady induced lung carcinoma at a success rate of 75%. Administration with green tea drinking significantly reduced the incidence of lung carcinoma to 30%. Green tea up-regulated p53 expression in lung carcinoma, but significantly down-regulated bcl-2 expression.

CONCLUSIONS:

Intra-pulmonary injection of 3,4-benzopyrene can steady induce lung carcinoma in rats, and green tea has preventive effect against lung cancer possibly by regulating expression of some critical genes such as p53 and bcl-2.

• Authors: Qihua Gu, Chengping Hu, Qiong Chen, Ying Xia, Juntao Feng, Hongzhong Yang
• Journal: Cancer detection and prevention (Cancer Detect Prev) Vol. 32 Issue 5-6 Pg. 444-51 ( 2009) ISSN: 1525-1500 [Electronic] England
• PMID: 19588545 (Publication Type: Journal Article)

Chemical References

• Anticarcinogenic Agents
• Flavonoids
• Phenols
• Plant Extracts
• Polyphenols
• Proto-Oncogene Proteins c-bcl-2
• RNA, Messenger
• Tea
• Tumor Suppressor Protein p53
• Benzo(a)pyrene

Topics

• Animals
• Anticarcinogenic Agents (therapeutic use)
• Benzo(a)pyrene
• Carcinoma (chemically induced, genetics, metabolism, prevention & control)
• Chemoprevention
• Disease Models, Animal
• Down-Regulation
• Female
• Flavonoids (therapeutic use)
• Gene Expression Regulation, Neoplastic
• Lung Neoplasms (chemically induced, genetics, metabolism, prevention & control)
• Phenols (therapeutic use)
• Plant Extracts (therapeutic use)
• Polyphenols
• Proto-Oncogene Proteins c-bcl-2 (genetics, metabolism)
• RNA, Messenger (analysis)
• Random Allocation
• Rats
• Rats, Sprague-Dawley
• Tea
• Tumor Suppressor Protein p53 (genetics, metabolism)
• Up-Regulation