Objective: To investigate the expression of programmed cell death 4 (PDCD4) protein and its clinicopathological significance in human pancreatic cancer.
Methods: Immunohistochemistry was used to examine the expression of PDCD4 protein in 69 specimens of pancreatic cancer and Western blot in 8 fresh specimens.
Results: The expression of PDCD4 protein was significantly lower in all 8 fresh pancreatic cancer tissues than that in non-cancerous tissues detected by Western blot. Compared with non-cancerous pancreatic tissue (> 80% of positive cells), low PDCD4 expression was shown in 69 pancreatic cancer tissues (< 30% of positive cells in 36 cases and 30%-80% of positive expression cells in 33 cases). In the 33 cases with 30% and 80% of positive expression cells, the expression rates of PDCD4 protein were 57.6%, 24.2%, and 18.2% in well, moderately, and poorly differentiated cancers, respectively. In the 36 cases less than 30% of positive expression cells, however, the expression rate of PDCD4 protein in well, moderately, and poorly differentiated cases were 19.4%, 41.7%, and 38.9%, respectively. 67.4% (15/23) of the moderately differentiated cases and 70% (14/20) of the poorly differentiated cases showed < 30% of positive expression cells. Only 26.9% (7/26) of the well differentiated cases, however, showed < 30% of positive expression cells, indicating that low PDCD4 expression was associated with histological grade (P < 0.01). There was no relationship between PDCD4 expression and other clinicopathological parameters including patients' sex, age, and TNM stage.
Conclusions: Expression of PDCD4 protein is low in human pancreatic cancer and is correlated with the differentiation levels of human pancreatic cancer. PDCD4 may play an important role in the occurrence and development of pancreatic carcinomas.