SNX2112 (PF 04928473) is an orally active Hsp90 inhibitor, with a Kd of 16 nM.

HSP90 β:30 nM(Ka), HSP90 α:30 nM(Ka)

向BT-474细胞处理1 μM SNX-2112会在化合物暴露后3至6小时内导致HER2表达下调，到10小时时HER2表达几乎完全丧失。SNX-2112的处理还导致总Akt表达降低。SNX-2112对BT474、SKBR-3、SKOV-3、MDA-468、MCF-7和H1650癌细胞具有抑制细胞增殖的作用，IC50值在10到50 nM范围内。这些抗增殖效果与Rb的低磷酸化、G1期阻滞以及适度的凋亡水平相关。[1]SNX-2112与Hsp90的N端腺苷三磷酸结合位点有竞争性结合。通过caspase-8、-9、-3以及聚(ADPribose)聚合酶的剪切，SNX-2112诱导凋亡。SNX-2112抑制由细胞因子引起的Akt和细胞外信号相关激酶（ERK）激活，并克服了由白细胞介素-6、胰岛素样生长因子-1和骨髓基质细胞赋予的生长优势。SNX-2112通过消除eNOS/Akt通路明显抑制人脐静脉内皮细胞的管形成，并通过下调ERK/c-fos和PU.1显著抑制破骨细胞形成。[2]研究表明，来自骨肉瘤、神经母细胞瘤、肝母细胞瘤和淋巴瘤的八条细胞线对SNX-2112敏感，IC50值在10-100 nM之间。更高剂量（70 nM）显示出更长时间的抑制作用和更大的次G1期累积。随时间推移观察到的Akt1和C-Raf水平显著降低，伴随着PARP剪切的增加。[3]近期研究指出，NX-2112通过Akt/mTOR/p70S6K抑制以时间和剂量依赖的方式诱导自噬。SNX-2112在人类黑色素瘤A-375细胞中诱发显著的凋亡和自噬，可能是一种有效的靶向治疗化合物。[4]

SNX-2112，通过其前药SNX-5422传递，不仅抑制MM细胞增长并在异种移植小鼠模型中延长生存期，而且通过阻断Hsp90，SNX-2112不仅抑制MM细胞增长，还能在骨髓微环境中阻止血管生成和破骨细胞生成。[2]

ATP Displacement Assay: For the protein affinity-displacement assay, a purine-based affinity resin is generated by incubating ATP-linked Sepharose with Jurkat cell lysate (flash frozen and homogenized in saline) at 4 °C. This is then incubated with SNX-2112 for 90 minutes. Proteins eluted by drug are then resolved by SDS-PAGE, visualized with silver staining, and excised from the gel for MS-based identification. Briefly, after destaining and trypsin digestion, peptides are extracted with μC18 ZipTips and then eluted and spotted directly to a conventional stainless steel matrix-assisted laser desorption/ionization target with a saturated solution of α-cyano-4- hydroxycinnamic acid in 50% acetonitrile, 0.15% formic acid. Mass spectra are then acquired using a MALDI-TOF/TOF 4700 Proteomics Analyzer. MS spectra are acquired (1,000 shots per spectrum), and the three peaks from each with the greatest signal-to-noise ratio are automatically submitted for tandem MS analysis (3000 shots per spectrum). The collision energy is 1keV. Air is used as the collision gas. Protein identification is done from the MS and tandem MS data using GPS Explorer software with the integrated Mascot database search engine.

Cell viability is determined by seeding 2-5 × 103 cells per well in 96- well plates and treating with SNX-2112 24 hours after plating in complete medium (200 μL). Each drug concentration is tested in eight wells. Cells are assayed using the Alamar blue viability test after a 96-h incubation. Flow cytometry is done using nuclei stained with ethidium bromide and isolated via the Nusse protocol(Only for Reference)