Objective: To establish a model of pancreatic cancer in Spragu-Dawely (SD) rats, and to examine the expression level of KiSS-1mRNA in pancreatic cancer and non-cancerous pancreatic tissues in SD rats.
Methods: Dimethylbenzanthracene (DMBA) was directly implanted into the parenchyma of pancreas in SD rats (Group A), and DMBA combined with trichostatin (TSA) was implanted in the intervention group (Group B). The carcinogenesis of rats executed within 3 - 5 months in Group A and Group B were observed by HE staining and macrography. Meanwhile, the rats in the control (Group C) were executed in 5 months. The expression of KiSS-1mRNA was assayed by in situ hybridization.
Results: (1) The incidence of pancreatic cancer in Group A within 3 - 5 months was 48.7% (18/37), including 17 cases of pancreatic ductal adenocarcinoma and 1 case of fibrosarcoma. The incidence of pancreatic cancer in Group B was 33.3% (12/36), including 11 pancreatic ductal adenocarcinoma and 1 fibrosarcoma. The maxial diameter of tumor mass in Group A was higher than that in Group B (P<0.05). (2) The positive rates of KiSS-1 mRNA in pancreatic cancer in Group A and Group B were significantly lower than those in non cancerous pancreatic tissues in Group A and Group B (P<0.01). The positive rates of KiSS-1mRNA in Group A or Group B with ductal adenocarcinoma were significantly lower than those in Group A or Group B without ductal adenocarcinoma (P<0.01). The middle or severely atypical ductal hyperplasia was observed in non-cancerous pancreatic tissues with the negative KiSS-1mRNA.
Conclusion: DMBA directly implanted into the parenchyma of pancreas can obtain an ideal pancreatic cancer model with high incidence in a short time. TSA may have an inhibitive effect on the carcinogenesis and the growth of pancreatic ductal adenocarcinoma in rats, and KiSS-1 may play an important role in inhibiting the invasion and metastasis of pancreatic cancer.