NSC 185058 is an inhibitor of ATG4B, a major cysteine protease. It also can attenuate the autophagic activity.

NSC185058有效抑制了两种细胞类型中由饥饿引起的自噬。当MDA-MB468细胞在饥饿状态下处理NSC185058时，标记有GFP-LC3B的自噬囊泡(AVs)消失。NSC185058对饥饿引起的蛋白质代谢的抑制效果与3MA相当。

小鼠每隔24小时被注射载体或NSC185058，并通过20小时禁食诱导自噬。相较于自由进食的小鼠，禁食导致GFP-LC3B 自噬囊泡(AVs)的增加。与禁食的小鼠相比，NSC185058显著减少了GFP-LC3B 自噬囊泡的出现。

Saos-2 transiently expressing FYVE-RFP was incubated in DMEM medium supplemented with amino acids and serum (Fed) or Krebs-Heinseleit medium lacking amino acids and serum (Starved). The starved cells were incubated in the presence and absence of the NSC185058 or NSC377071 for 4 h at which time the cells were examined by fluorescence microscopy. The numbers of red "dots" per cell was quantified using ImageJ software. Taking into account basal responses, those cells with 3 or more puncta were defined as PtdIns3K active.

Immunodeficient nu/nu nude female mice were injected subcutaneously with 6 × 10^6 Saos-2 (GFP-LC3B), shCon-Saos-2(GFP-LC3B) or shATG4B-Saos-2(GFP-LC3B) cells. Palpable Saos-2 (GFP-LC3B) tumors developed in 7 to 10 d, at which time, the mice were divided into 2 groups and injected IP on Monday, Wednesday, and Friday with either peanut oil vehicle or NSC185058 (100 mg/kg body weight) dissolved in peanut oil. Over time, the tumor dimensions were measured using calipers and volumes calculated using the formula: (W2 × L)/2.