In pancreatic adenocarcinoma, the presence of CD4+ TILs together with CD8+ TILs serves as a good indicator of the patient's outcome after surgical treatment.

Caveolin-1 is a major component of caveolae and plays a regulatory role in several signalling pathways. Caveolin-1 was recently identified as a metastasis-related gene in prostate cancer. The clinical effects of caveolin-1 expression in pancreatic carcinoma, however, remain unknown. In this study, we have investigated the relationship between caveolin-1 expression and the clinicopathologic variables and clinical outcome in 79 patients with pancreatic adenocarcinoma undergoing surgical resection. Caveolin-1 expression was determined by immunohistochemistry, using a polyclonal anti-caveolin-1 antibody. Patients were divided into two groups based on the extent of caveolin-1 expression: a negative expression group (immunoreactivity in less than 50% of cells) and a positive expression group. Positive caveolin-1 immunostaining was detected in 32 cases (40.5% of total), while non-neoplastic ductal epithelium showed little or no staining. Positive caveolin-1 expression was correlated with tumour diameter (P=0.0079), histopathologic grade (P=0.0272) and poor prognosis (P=0.0008). Upon multivariate analysis with Cox's proportional hazards model, positive caveolin-1 expression was shown to be an independent negative predictor for survival (P=0.0358). These results suggest that caveolin-1 overexpression is associated with tumour progression, thereby indicating a poor prognosis for certain patients undergoing surgical resection for pancreatic carcinoma.

We conclude that MMR protein expression, detected by immunohistochemistry, is a useful marker providing information necessary to decide appropriate therapeutic strategies in patients with ESCC.

The transcription factor E2F-1, a downstream regulator of the p16-cyclinD-Rb pathway, is required for cell cycle progression. Evidence shows that overexpression of E2F-1 can either promote or inhibit the development of tumors, depending on tissue or experimental conditions. However, the clinical impact of E2F-1 expression on esophageal squamous cell carcinoma (ESCC) remains unknown. To analyze E2F-1 expression in ESCC, we investigated the immunoreactivity of E2F-1 and its correlation with clinicopathological features in 122 patients who underwent surgical resection for ESCC. Positive E2F-1 immunostaining was detected in 73 patients (59.8%). Positive E2F-1 immunostaining correlated positively with pathologic stage (P = 0.0103), p-Grade (P = 0.0014) and pT (P = 0.0192). The overall survival rate was worse in patients with E2F-1-positive tumors than in patients with E2F-1-negative tumors (P = 0.0290). Over-expression of E2F-1 is associated with tumor progression and a worse prognosis after surgery in ESCC.

This is the first report to correlate DARPP-32 immunoreactivity (dopamine and cAMP-regulated phosphoprotein, M r 32 000) to clinicopathological status in human cancer. DARPP-32 is recognised as a neuronal protein. A recent study demonstrated that DARPP-32, and a truncated isoform t-DARPP, are overexpressed in gastric carcinoma during the process of carcinogenesis. The biological function of DARPP-32, however, is still unclear. The purpose of this study was to clarify the roles of DARPP-32 and t-DARPP in oesophageal squamous cell carcinoma (OSCC). Initially, we investigated DARPP-32 and t-DARPP expression in OSCC cell lines by Reverse transcription -polymerase chain reaction and Western blot. DARPP-32 expression was observed in four out of seven (57.1%) cell lines, but t-DARPP expression was not observed in any cell lines. In oesophageal tissue sample, DARPP-32 expression was observed in four out of seven (57.1%) tumour tissues, while t-DARPP was not observed in any tissues. Subsequently, DARPP expression was assessed by immunohistochemistry, using a polyclonal antibody, in tissue sections from 122 patients with primary OSCC. DARPP immunoreactivity was not observed in any normal oesophageal mucous membranes. On the other hand, positive DARPP immunostaining was detected in 37 patients (30.3%) and correlated inversely with pathologic stage (P ¼ 0.0284), pT (P ¼ 0.0438), pN (P ¼ 0.0303) and tumour size (P ¼ 0.012). The overall survival rate was worse in patients with DARPP-negative tumours than in patients with DARPP-positive tumours (P ¼ 0.0453). Interestingly, DARPP expression was observed in only one out of 45 cases of dysplasia. These observations suggest that DARPP-32 (rather than t-DARPP) expression arises after a phase of dysplasia in OSCC, and that tumours expressing DARPP-32 progress less rapidly than DARPP-32-negative tumours.