Dynamic coupling of 99mTc-MIBI efflux and apoptotic pathway activation in untreated breast cancer patients

Silvana Del Vecchio, Antonella Zannetti, Andrea Ciarmiello, Luigi Aloj, Corradina Caracò, Rosa Fonti, Gerardo Botti, Giuseppe D'Aiuto, Marco Salvatore

Research output: Contribution to journalArticlepeer-review

Abstract

Our previous studies showed that the efflux rate of technetium-99m methoxyisobutylisonitrile (MIBI) is directly correlated to P-glycoprotein (Pgp) levels in breast carcinoma. The aim of this study was to test whether the Pgp-dependent efflux of 99mTc-MIBI is related to the apoptotic pathway activation in breast carcinoma. Thirty-three untreated non-consecutive patients were intravenously injected with 740 MBq 99mTc-MIBI and serial images were obtained up to 4 h. The rate of efflux was determined by mono-exponential fitting of decay-corrected time-activity curves. Tumour specimens were then obtained at surgery and processed for the determination of the apoptotic index by in situ end-labelling of DNA fragments (Tunel). The rate of tumour cell proliferation was also determined using Ki67 monoclonal antibody. All breast carcinomas showed focal uptake of 99mTc-MIBI and the time to half clearance varied between 85 and 574 min. The apoptotic index ranged between 0.3% and 4.2%, whereas the rate of proliferation varied between 13% and 40%. We found a positive and significant correlation between the apoptotic index and the rate of proliferation (r=0.79, P99mTc-MIBI was directly and significantly correlated with the apoptotic index (r=0.74, P99mTc-MIBI (r=0.57, P99mTc-MIBI sequestration, a model for the dynamic coupling of Pgp-dependent 99mTc-MIBI efflux and apoptotic pathway activation may be derived.

Original languageEnglish
Pages (from-to)809-814
Number of pages6
JournalEuropean Journal Of Nuclear Medicine
Volume29
Issue number6
DOIs
Publication statusPublished - 2002

Keywords

  • Tc-MIBI efflux
  • Apoptosis
  • Breast cancer
  • Multidrug resistance

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

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