Zob Daniela 1, Gruia Iuliana 1, Anghel Rodica 1
1 Oncology Institute “Prof Al Trestioreanu”, Bucharest
Abstract
Breast cancer represents the most common form of cancer women develop. Although prognosis
has significantly improved over the last years, due to increasing trends in early diagnosis and advanced
treatment, the medical community still faces a series of severe problems. One of them is resistance to
certain chemotherapy agents that constitutes the main cause of death in more than 90% of patients.
Despite intense and thorough studies on resistance mechanisms, their relevance for the clinical practice
continues to be unclear. The present paper aims to identify a possible resistance mechanism pattern to
chemotherapy applied in breast cancers, which includes the attachment of cytostatics to albumin thiols,
as a consequence of oxidized protein degradation. Given their chemical structure, these thiols may be
responsible for the impossibility of cytostatics to bind to transport albumins, thus inducing therapeutic
failures and implicitly resistance. The content of this article focuses on the measurement of albumin thiol
levels in patients diagnosed with breast cancer that developed resistance after the first series of antitumor
treatment. We also assessed the level of copper-carrying proteins, namely ceruloplasmin involved
in oxidation-reduction reactions as well as the overall level of non-enzymatic endogenous antioxidants.
The results reveal the occurrence of a significantly damaging oxidative stress that destroys the structure
of transport proteins and, indirectly, can create resistance mechanisms.