Spontaneous in vitro apoptosis of de novo chronic lymphocytic leukemia cells correlates with risk of the disease progression.

Despite significant progress in treatment, chronic lymphocytic leukemia (CLL) still remains an incurable disease. Major advances have been recently made to understand the molecular pathogenesis underlying CLL, but defects in apoptosis are considered to be the most important factors. Although neoplastic cells are resistant to apoptosis in vivo, they show decreased level of spontaneous in vitro apoptosis, with significant differences among CLL patients. This work compares the level of spontaneous CLL cell apoptosis with prognostic factors and clinical course of the disease. In vitro spontaneous apoptosis of peripheral blood lymphocytes was analyzed using Annexin-V assay (confirmed by TUNEL method) in 135 treatment naïve patients with CLL. Levels of apoptosis after 48h culture in patients with stable disease were found to be significantly higher than in the group with progressive course of the disease (p=0.015). Moreover, the level of spontaneous apoptosis after 24h and 48h of incubation correlated inversely with the progression free survival (p=0.026 and 0.009, respectively). These results suggest that in vitro spontaneous apoptosis of CLL cells may be a simple and cheap prognostic test which is relatively quick to use, and can predict the course of the disease and response to treatment. © 2014 Clinical Cytometry Society.

Cytotoxic activity of the amphibian ribonucleases onconase and r-amphinase on tumor cells from B cell lymphoproliferative disorders.

Although major advancements in antitumor treatment have been observed, several B cell-derived malignancies still remain incurable. A promising approach that involves targeting RNA either by the use of specific antisense oligonucleotides or cytostatic/cytotoxic ribonucleases (RNases) is being promoted. Two amphibian RNases, onconase (ONC; ranpirnase) and, more recently, r-amphinase (r-Amph), have already been tested, but thus far, mostly on solid tumors. In this study, for the first time we provide comprehensive data on ex vivo and in vivo cytotoxic activity of ONC or r-Amph against cancer cells from different B cell lymphoid malignancies, together with their detailed mode of antitumor action. Our data revealed strong pro-apoptotic activity of ONC and r-Amph in both chronic lymphocytic leukemia and aggressive B cell lymphomas, with less impact on acute lymphoblastic leukemia or multiple myeloma cells. Moreover, the antitumor action of ONC and r-Amph was markedly selective against neoplastic cells sparing normal, healthy control­derived lymphocytes.