Di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and its analogues are potent anti-cancer agents through their ability to target lysosomes. Considering this, it was important to understand the mechanisms involved in the Dp44mT-mediated induction of autophagy and the role of 5′-adenosine monophosphate-activated protein kinase (AMPK) as a critical autophagic regulator.

As such, this investigation examined AMPK's role in the regulation of the transcription factor EB (TFEB), which transcribes genes involved in autophagy and lysosome biosynthesis. For the first time, this study demonstrated that Dp44mT induces translocation of TFEB to the nucleus. Furthermore, Dp44mT-mediated nuclear translocation of TFEB was AMPK-dependent. Considering that: (1) the mammalian target of rapamycin complex 1 (mTORC1) plays an important role in the regulation of TFEB; and (2) that AMPK is a known regulator of mTORC1, this study also elucidated the mechanisms through which Dp44mT regulates nuclear translocation of TFEB via AMPK. Silencing AMPK led to increased mTOR phosphorylation, that activates mTORC1. Since Dp44mT inhibits mTORC1 in an AMPK-dependent manner through raptor phosphorylation, Dp44mT is demonstrated to regulate TFEB translocation through dual mechanisms: AMPK activation, which inhibits mTOR, and inhibition of mTORC1 via phosphorylation of raptor. Collectively, Dp44mT-mediated activation of AMPK plays a crucial role in lysosomal biogenesis and TFEB function. As Dp44mT potently chelates copper and iron that are crucial for tumor growth, these studies provide insight into the regulatory mechanisms involved in intracellular clearance and energy metabolism that occur upon alterations in metal ion homeostasis.

二-2-吡啶基酮4,4-二甲基-3-硫代半碳酮（Dp44mT）及其类似物通过靶向溶酶体的能力而成为有效的抗癌药。考虑到这一点，重要的是了解参与Dp44mT介导的自噬诱导的机制，以及5'-腺苷单磷酸激活的蛋白激酶（AMPK）作为关键的自噬调节剂的作用。

因此，这项研究检查了AMPK在转录因子EB（TFEB）调控中的作用，该转录因子转录了涉及自噬和溶酶体生物合成的基因。这项研究首次证明Dp44mT诱导TFEB易位至细胞核。此外，Dp44mT介导的TFEB核转位是AMPK依赖的。考虑到：（1）雷帕霉素复合物1（mTORC1）的哺乳动物靶标在TFEB的调节中起重要作用；（2）AMPK是mTORC1的已知调节剂，这项研究还阐明了Dp44mT通过AMPK调节TFEB核易位的机制。静音AMPK导致mTOR磷酸化增加，从而激活mTORC1。由于Dp44mT通过猛禽磷酸化以AMPK依赖的方式抑制mTORC1，因此Dp44mT被证明通过双重机制调节TFEB易位：AMPK激活，抑制mTOR，以及通过猛禽磷酸化抑制mTORC1 。总体而言，Dp44mT介导的AMPK激活在溶酶体生物发生和TFEB功能中起着至关重要的作用。由于Dp44mT有效螯合对肿瘤生长至关重要的铜和铁，这些研究为了解细胞内清除和金属离子稳态改变后发生的能量代谢所涉及的调节机制提供了见识。