Figure 1: HDAC and CTSL activities are increased in cancer cells. | Nature Communications

Figure 1: HDAC and CTSL activities are increased in cancer cells.

From: Selective cancer targeting with prodrugs activated by histone deacetylases and a tumour-associated protease

Figure 1

(a) Comparative HDAC activity of the panel of cancer and normal cell lines measured by a standard HDAC assay using substrate Boc-Lys(Ac)-AMC, either with vehicle control DMSO or HDACi TSA (1 μM). (b) Comparative live-cell CTSL activity of the same cell lines as in a using substrate Boc-Lys-AMC, either with vehicle control DMSO or CTSL inhibitor Z-FY-CHO (100 μM). (c) Comparative live-cell enzymatic activity of the same cell lines as in a using substrate Boc-Lys(Ac)-AMC, either with vehicle control DMSO, TSA (1 μM) or Z-FY-CHO (100 μM). (d) Effect of HDACi on live-cell enzymatic activity of cancer cells (HCT116 and HeLa) was examined using class I (HDAC1, 2, 3 and 8)- and class IIb (HDAC6 and 10)-specific substrate Boc-Lys(Ac)-AMC either with vehicle control DMSO or indicated HDACi. HDACi used were pan-HDACi (TSA, LBH589, SAHA and JNJ-26481585), class II-specific HDACi (MC1568) and class I HDAC subtype-specific HDACi (Apicidin, MGCD0103 and MS-275). The specificity of the subtype inhibitors is shown above the respective panels. HD, HDAC; Δ, inactive or less active (IC50>1 μM range)31. The assays were performed as in c. (e) Effect of selective CTSL inhibitors on the live-cell enzymatic activity of cancer cells (HCT116 and HeLa) was examined using substrate Boc-Lys(Ac)-AMC or Boc-Lys-AMC, either with vehicle control DMSO, Z-FY-CHO (100 μM), Z-FF-FMK (100 μM, Cathepsin L Inhibitor I, Calbiochem) or Z-FY(t-Bu)-DMK (10 μM, Cathepsin L Inhibitor III, Calbiochem). The assays were performed as in b,c. Data represent mean values of triplicate measurements±s.d. RFU, relative fluorescent units.

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