Sentence: The combination of melatonin at concentrations of 50 μM with increasing doses of irinotecan ( 7.5 , 15 , 30 , and 60 μM ) resulted in an increase in the amount of DNA damage in A549 and HT29 cancer cells , but was not effective in inducing DNA damage in healthy human lymphocytes .
Drug combination annotation:
[{'class': 'POS', 'spans': ['melatonin', 'irinotecan'], 'is_context_needed': False}]