PENTOXIFYLLINE ENHANCES IN VITRO T-CELL ANTITUMOR RESPONSE IN BREAST CANCER PATIENTS

The NF-κB transcription factor controls the expression of genes responsible for cell cycle, apoptosis, and other immunoregulatory functions. Some nonspecific NF-κB inhibitors were found after discovering the possibility of blocking tumor growth through suppression of NF-κB activity, but their use was complicated by multiple side effects, such as interleukin-1β-related systemic inflammation or non-immunerelated complications, which may be due to inhibition of the p65 NF-κB subunit that plays a central role in organogenesis and inflammation. Inhibition of the c-Rel subunit leads to tumor growth restriction by modulating the T-regulatory cell activity.

In 2017, Grinberg-Bleyer and co-authors checked the hypothesis that selective inhibition of the c-Rel subunit can be performed using pentoxifylline and will effectively regulate Treg activity during tumor growth. The authors showed that pentoxphylline, an FDA-approved drug, could indeed induce selective degradation of c-Rel without affecting p65, and suggested that such an effect could be effective in suppressing tumor growth. In this regard, we aimed to investigate in vitro how pentoxifylline affect the functional activity and antitumor cytotoxic potential of T-cells in cancer patients.

The objects of the study were peripheral blood mononuclear cells from 25 patients with primary breast cancer (no metastases), 15 patients with metastatic breast cancer, and 25 healthy women without breast pathology. Informed consent was obtained from all donors and patients. The study was approved by the local ethics committee.

Here we showed that pentoxifylline treatment in vitro enhances the pro-apoptotic and cytotoxic antitumor response via increasing the expression of TRAIL on T-lymphocytes, mainly in healthy donors and patients with metastatic breast cancer, both on intact T-cells and in response to the cells of the tumor line of human breast carcinoma ZR-75-1. In healthy donors, in the presence of pentoxifylline, a population of highly expressing TRAIL CD4 and CD8 T-cells appears. 

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