passages.id: split_4_test_811_passage
passages.type: progene_text
passages.text: Western blot analysis suggests that NO donors did not cause HO-1 protein loss and Northern blot analysis of HeLa cells treated with SIN-1 and SNP indicates that , unlike HO-1 mRNA , which is remarkably responsive to the treatments , HO-2 mRNA levels were modestly increased ( approximately two to threefold ) by NO donors .