Rate of 14CO2 production from variously labeled forms of [14C]glucose in human breast invasive ductal carcinoma tissues.

To establish possible cancerous aggressiveness between the metabolism of variously labeled [14C]glucose in the human breast invasive ductal carcinoma (IDC) tissues, we measured the rates of 14CO2 production from those tissues by using radiorespirometry, expressing the results as initial velocity (V) in nanomoles of 14CO2 min-1 g-1 of fresh tissues. The Vc data were compared with results of the SBR system, which grades up from I to III. Vc,1 values measured with [1-14C]glucose increased from 1.99-2.82 for SBR I to 3.90-4.09 for SBR II, finally reaching 4.83-7.04 for SBR III, thus matching clearly the increase of IDC cancerous aggressiveness. Conversely, data obtained from [3,4-14C]glucose and [6-14C]glucose decreased with increasing cancer stage: i.e., with [3,4-14C]glucose, Vc,3,4 values were 5.79-9.34 for SBR I, 4.45-4.84 for SBR II, and 2.35-1.90 for SBR III; with [6-14C]glucose, the corresponding Vc,6 values were 1.34-1.90, 1.33-1.41, and 0.72-0.79. The Vn,1/Vn,6 ratios were close to unity for normal tissues and for noncancerous tissues surrounding SBRI tumors. For cancerous tissues, however, the Vc,1/Vc,6 ratios were 1.5, 2.9, and 6.1-9.8 in IDC tissues graded as SBR I, II, and III, respectively. The results suggest the possible use of radiorespirometry as a tool to assess IDC aggressiveness.