Objective: To study the clinicopathological significance of the expression of carbonic anhydrase (CA)II protein and mRNA in primary invasive ductal cancer (IDC) of human pancreas.
Methods: The expression of CAII protein in 33 paired paraffin embedded IDC specimens of the pancreas and paired adjacent non-cancerous pancreatic tissues was detected by immunohistochemistry. Western blot and reverse transcription polymerase chain reaction (RT-PCR) were used to examine the expression of CAII protein and mRNA level in 12 paired fresh IDC specimens of the pancreas and adjuvant non-cancerous pancreatic tissues. The relationship between the protein expression and clinicopathological features was analyzed.
Results: Overexpression of CAII protein was shown in 11 cases of pancreatic IDC tissues (33.3%, 11/33), which was much lower than that in paired non-cancerous pancreatic tissues (72.7%, t = 6.275, P = 0.000). The expression of CAII protein had no correlation with tumor position (χ² = 0.992, P = 0.319), differentiation (χ² = 0.866, P = 0.352), TNM stage (χ² = 1.210, P = 0.271) and Lymph node metastasis (χ² = 0.798, P = 0.372), but had bordering statistic sig with the prognosis of the patients (χ² = 3.233, P = 0.072). The median survival time in the patients with high expression of CAII protein was 540 days, while that in the patients with low expression was 320 days. The expression of CAII protein and mRNA was lower in IDC than that in paired non-cancerous pancreatic tissues detected by Western blot and RT-PCR respectively (t = 3.399, P = 0.006; t = 2.281, P = 0.043).
Conclusion: CAII is down regulated in pancreatic IDC and might be relative with the prognosis.