Blood-borne RT-PCR assay for prostasin- specific transcripts to identify circulating prostate cells in cancer patients

OBJECTIVE

The aim of this study was to establish the specific detection of prostasin-expressing prostate cells in the blood of patients with prostate cancer.

PATIENTS AND METHODS

A prostasin-specific RT-PCR assay was developed and optimized using limiting dilutions of cell line LNCaP mixed with normal blood specimens. Then, it was used to examine peripheral blood samples from 96 patients with prostate cancer (localized carcinoma, n = 69, metastatic, n = 27). Specificity was assessed by examination of 86 negative controls (healthy individuals, n = 47, benign prostate hyperplasia, n = 17, nonprostate cancer patients, n = 22).

RESULTS

All 86 control samples failed to amplify the specific 546-bp prostasin PCR products. Blood samples from 35 out of 96 (36%) prostate cancer patients were found positive. In metastatic patients, 63% (17/27) scored positive whereas in localized adenocarcinoma prostasin primers detected prostate cells in 26% (18/69).

CONCLUSION

Our results that approximately 30% of patients with localized prostate cancer scored positive for prostasin-specific RT-PCR confirm that the hematogenous spillage of prostate cells is an early event in the natural history of prostate cancer. As none of our negative controls were found positive, we conclude that blood-borne RT-PCR amplification of prostasin transcripts may lead to an earlier diagnosis of disseminated disease in patients with organ-confined carcinoma. The clinical significance of prostate cell detection and the potential applications of this new tool aside or along prostate-specific antigen or prostate-specific membrane antigen RT-PCR require longer-term follow-up.

Serum levels of endothelial injury markers creatine kinase-BB and soluble thrombomodulin during human liver transplantation

Endothelial damage within the sinusoids of the liver probably plays a key role in primary liver dysfunction following transplantation. The aim of this work was to study the serum levels of two potential markers of endothelial damage, creatine kinase-BB and soluble thrombomodulin, during human graft revascularization. Thirteen human liver grafts were preserved in UW solution (mean time: 13.8 h). Creatine kinase-BB and transaminase activities and soluble thrombomodulin levels were measured: 1) in effluent and 2) in serum samples sequentially collected before revascularization, then during the first 120 min of revascularization and first post-operative week. No correlation was observed between serum values (peak) and effluent values. In serum, pre-operative creatine kinase-BB activities were correlated with soluble thrombomodulin levels (p = 0.01). Both increased significantly during the first minutes of the revascularization, then decreased markedly. In contrast, AST activity was maximal at day 1. This detectable and early release of creatine kinase-BB and soluble thrombomodulin in blood is in keeping with the early occurence of endothelial damage. Together with previous data, these findings suggest that serum determination of these two markers may be a useful tool in the assessment of endothelial injury in liver transplantation.

Tumor necrosis factor-alpha in liver transplantation and resection. No evidence for a key role in ischemia-reperfusion injury

Experimental studies have shown that liver ischemia-reperfusion induces Kupffer cell activation and tumor necrosis factor-alpha (TNF alpha) release. The aim of this work was to determine whether severe hepatic ischemia and subsequent reperfusion triggers TNF alpha release in man. Serum TNF alpha was measured before and 3, 10, 30, 60, 120 min after revascularization and postoperatively at day 1 and 2 in 11 patients with orthotopic liver transplantation (group 1) and 4 patients with liver resection with vascular occlusion (group 2). In group 1, TNF alpha levels decreased during the first few minutes of reperfusion, then increased slightly to peak at 120 min (40 +/- 13 pg/ml). Primary non-function occurred in 1 patient in whom low peroperative levels of TNF alpha levels were measured. In group 2, no significant changes in TNF alpha levels were observed. These data, in a small number of patients: (a) show that hepatic ischemia-reperfusion does not result in major TNF alpha production; (b) do not support a primary pathogenic role for TNF alpha in damage after ischemia-reperfusion in humans.