Abstract—Cancer cells are characterized by an increased level of metabolism and are highly dependent on the correct functioning of the processes that ensure homeostasis. Reactive sulfur species (RSS) are important molecular modulators of metabolic processes in both healthy and tumor cells. The effect of RSS and, in particular, H₂S, on key cellular systems, including the ubiquitin–proteasome system (UPS), which provides the destruction of most intracellular proteins, has been shown. The main components of the UPS are proteasomes, multisubunit protein complexes, within which proteolysis occurs. At the same time, data on the effect of H₂S directly on the pool of proteasomes in tumor cells are insufficient. Here, we studied the effect of incubation of SW620B8-mCherry colorectal adenocarcinoma cells expressing a fluorescently labeled proteasome subunit with 50, 100, and 200 µM of the hydrogen sulfide donor GYY4137. The effect of the substance on the proteasome pool was assessed 6, 24, 48, and 72 h after administration. It was shown that the chymotrypsin-like and caspase-like proteasome activity decreases in cells incubated with 200 µM of the GYY4137 for 24 h. This coincided with an increase in the expression of proteasome subunit genes. In lysates of cells incubated with 200 µM GYY4137 for 48 h an increase in the content of the constitutive β5 subunit was observed and the activity of proteasomes leveled off. Following prolonged incubation with GYY4137 (72h), an increase in the expression levels of some proteasome genes was also observed, although this did not have a significant effect on the activity and subunit composition of proteasomes. Thus, the obtained data indicate the modulation of proteasome activity by the hydrogen sulfide donor and the effect of GYY4137 on transcription and translation of proteasome genes.

摘要：癌细胞的特点是新陈代谢水平升高，并且高度依赖于确保体内平衡的过程的正确运行。活性硫（RSS）是健康细胞和肿瘤细胞代谢过程的重要分子调节剂。RSS，特别是 H ₂ S，对关键细胞系统的影响，包括泛素-蛋白酶体系统 (UPS)，它可以破坏大多数细胞内蛋白质，这一点已经得到证实。UPS 的主要成分是蛋白酶体，即多亚基蛋白质复合物，在其中发生蛋白水解。同时，关于H ₂ S直接对肿瘤细胞中蛋白酶体池产生影响的数据还不够。在这里，我们研究了表达荧光标记蛋白酶体亚基的 SW620B8-mCherry 结直肠腺癌细胞与 50、100 和 200 µM 硫化氢供体 GYY4137 孵育的效果。给药后 6、24、48 和 72 小时评估该物质对蛋白酶体池的影响。结果表明，用 200 µM GYY4137 孵育 24 小时后，细胞中胰凝乳蛋白酶样和半胱天冬酶样蛋白酶体活性降低。这与蛋白酶体亚基基因表达的增加相一致。在与 200 µM GYY4137 孵育 48 小时的细胞裂解物中，观察到组成型 β5 亚基含量增加，蛋白酶体活性趋于平稳。与GYY4137长时间孵育（72小时）后，还观察到一些蛋白酶体基因的表达水平增加，尽管这对蛋白酶体的活性和亚基组成没有显着影响。因此，获得的数据表明硫化氢供体对蛋白酶体活性的调节以及GYY4137对蛋白酶体基因转录和翻译的影响。