HSF1-IN-3 

HSF1-IN-3 is a heat shock transcription factor 1 (HSF1) inhibitor with a K_d value of 23.8 μM against HSF1-DBD. HSF1-IN-3 inhibits the proliferation of cancer cells and induces their apoptosis, with stronger activity in androgen-dependent prostate cancer cells. HSF1-IN-3 reduces the expression of HSP70 and HSP90, downstream effectors of HSF1, and attenuates HSE-driven transcriptional activity. HSF1-IN-3 can be used in the research of cancers such as prostate cancer and leukemia^[1].

HSF1-IN-3 (Compound 1168) (0.78-25 μM; 30 min) dose-dependently disrupts the formation of purified recombinant human HSF1-DBD/HSE DNA complexes, with nearly complete inhibition observed at 12.5 μM^[1].
HSF1-IN-3 (4-20 μM; 72 h) inhibits the proliferation of various cancer cell lines (HCT116, PC-3, LNCaP, 22Rv1, K562, A549, HL60, HeLa), with IC₅₀ values ranging from 7.5 μM (HL60) to 19.5 μM (HeLa) after 72 h of treatment; meanwhile, the IC₅₀ value of this compound in non-cancerous HEK293 cells is 4-fold higher, indicating a potential therapeutic window^[1].
HSF1-IN-3 (2.5-20 μM; 10 days) inhibits the long-term clonogenic capacity of 22Rv1 prostate cancer cells in a dose-dependent manner^[1].
HSF1-IN-3 (5-20 μM; 48 h) activates the caspase-dependent apoptotic signaling pathway in HL60 leukemia cells in a dose- and time-dependent manner^[1].
HSF1-IN-3 (5-20 μM; 7-48 h) dose-dependently inhibits the expression of HSF1 and its downstream effector proteins (HSP70, HSP90, Akt) in HL60 leukemia cells and 22Rv1 prostate cancer cells under both basal and heat shock conditions. In addition, it reduces the level of androgen receptor in 22Rv1 cells^[1].
HSF1-IN-3 (5-20 μM; 7 h) dose-dependently inhibits HSE-mediated transcriptional activity in HEK293T cells, with an inhibition rate of approximately 70% at the concentration of 20 μM after heat shock treatment^[1].
HSF1-IN-3 (5-20 μM; 7 h) dose-dependently attenuates heat shock-induced phosphorylation of HSF1 Ser326 in 22Rv1 prostate cancer cells^[1].
HSF1-IN-3 (5-20 μM; 7 h) dose-dependently attenuates heat shock-induced phosphorylation of HSF1 Ser326 in HL60 leukemia cells, and this effect is independent of its downregulatory action on total HSF1 protein levels^[1].
HSF1-IN-3 (5-20 μM; 7 h) dose-dependently reduces the abundance of HSF1 trimers in heat shock-induced HL60 leukemia cells, and this effect is partially mediated by the proteasome-dependent degradation of HSF1^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

287.17

C₁₈H₁₈BN₃

CN(C=CN1C)C1BC2=NC3=C(C=CC=C3)C4=C2C=CC=C4

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• [1]. Pan X, et al.. Discovery of a borylated aza-arene chemotype as a direct HSF1 inhibitor targeting the DNA-binding domain. European journal of medicinal chemistry. 2026 Jun 09;316:119046.