Sentence: However , verapamil significantly increased the sensitivity to etoposide , doxorubicin and vincristine in cells highly expressing MRP gene .
Drug combination annotation:
[{'class': 'POS', 'spans': ['verapamil', 'etoposide'], 'is_context_needed': False}, {'class': 'POS', 'spans': [0, 2], 'is_context_needed': False}, {'class': 'POS', 'spans': [0, 3], 'is_context_needed': False}]