Only in patients with hormone-dependent breast infiltrating ductal carcinomas, CA15.3 serum levels are inversely correlated with the immunohistochemical expression of Bcl2.

OBJECTIVE: To study possible association between serum CA15.3 levels and immunohistochemical expression of Bcl2 in women affected by infiltrating ductal breast carcinomas. MATERIALS AND METHODS: Two hundred and fifty consecutives women with breast infiltrating ductal carcinomas, aged between 37 and 83 years were included in this study. Serum CA15.3 was determined by electro-chemoluminescence assay (ECLIA-Elecsys 170 Roche). Immunohistochemical staining on tissue sections of 4-5 microns was done by the EnVision method with a heat-induced antigen retrieval step. Antibody used for Bcl2 was (124, Dako, dilution 1/150). Bcl2 expression was assessed as negative (-), weak positive (+) or strong positive (++). RESULTS: In the study group, serum CA15.3 concentrations ranged between 1 and 1743 U/ml, with 25, 50 and 75 percentiles of 12.7, 17.6 and 24.3 U/ml respectively. Serum CA15.3 concentrations were higher in Bcl2 negative cases than in Bcl2 + and Bcl2 ++. We found statistically significant differences between subgroups Bcl2 negative and Bcl2 ++ (p=0.044), between Bcl2 + Bcl2 ++ (p=0.039) and between Bcl2 ++ and Bcl2 -/+ (p=0.013). When we considered 25 U/mL as the threshold of positivity, antigen values>25 U/ml were more frequent in tumors Bcl2- than in Bcl2 ++ (20/52 vs 29/170, p=0.001). The same behavior was observed when comparing the subgroups -/+ with ++ (p=0.001). A very important aspect of our work was that this CA15.3 behavior in relation to the immunohistochemical expression of Bcl2 was maintained in hormone-dependent tumors (ER+), but not in hormone-independent ones. CONCLUSIONS: The results led us to the following consideration: In women affected by infiltrating ductal breast carcinomas, serum levels of CA15.3 associated inversely, both qualitatively and quantitatively, with the immunohistochemical expression of Bcl2, but this fact exists only in hormone-dependent tumors.

Ionic dependence of the velocity of release of ATP from permeabilized cholinergic synaptic vesicles.

Evidence is provided to show that synaptic vesicles have an internal matrix. Suspensions of cholinergic synaptic vesicles isolated from the electric organ of Torpedo marmorata fish were permeabilized in solutions containing low concentrations of Na(+) or Ca(2+). The release of ATP from the vesicular matrix was 10 times more effective with Ca(2+) than with Na(+). We ascertained whether these two cations induced a different velocity of release of ATP from the matrix. The release of ATP was monitored with the chemiluminescent reaction of luciferin-luciferase. The light signal generated was the result of the kinetics of ATP release of the enzymatic reaction. To overcome the kinetics of the enzymatic reaction, the light records were deconvoluted. The actual kinetics of ATP release of vesicles containing Na(+) or Ca(2+) were coincident. To validate this result, comparison was made with ATP release from intact nerve terminals which were already deconvoluted. The results show that the real time course of release is longer than that obtained from synaptic vesicles. This was as expected given that the release of neurotransmitters is due to successive molecular steps of synaptic vesicle exocytosis.