Lung cancer is diagnosed at an advanced stage due to its unrecognized symptoms, resulting in high mortality. In recent decades, research into the development of an early diagnostic method for lung cancer has expanded in order to overcome the high mortality rate. Calpain 2 (CAPN2) has been suggested as a tumor marker linked to angiogenesis, cell proliferation, and migration in non-small cell lung cancer. In this study, CAPN2 enzyme-activatable near-infrared peptide sensor linked to human serum albumin (HSA-CAPN2) was developed. Intracellular localization and strong recovered fluorescence signals of HSA-CAPN2 were observed in in vitro experiments using A549-Luc cells, and signal recovery was inhibited by ALLN (a CAPN2 inhibitor). In vivo distribution and signal recovery evaluations performed using A549-Luc cell xenograft mice revealed that HSA-CAPN2 accumulated in the tumor region and produced high fluorescent signal recovery. Three-dimensional reconstructed images using single-plane illumination microscopy after tissue clarity visualized localization of HSA-CAPN2 in tumors. In addition, ALLN pretreatment showed a significant inhibitory effect on signal recovery of HSA-CAPN2, and that inhibition was induced by downregulation of CAPN2 at the gene and protein levels followed by decreases in Ca2+ levels. Overall, the results demonstrate the potential of HSA-CAPN2 as a sensor for CAPN2-enriched cancer.

中文翻译：

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使用人血清白蛋白结合的Calpain 2纳米传感器对Calpain 2富集的非小细胞肺癌进行无创早期检测。

由于无法识别的症状，肺癌被诊断为晚期，导致高死亡率。近几十年来，为了克服高死亡率，扩大了对肺癌的早期诊断方法的开发的研究。钙蛋白酶2（CAPN2）被认为是与非小细胞肺癌中血管生成，细胞增殖和迁移相关的肿瘤标志物。在这项研究中，开发了与人血清白蛋白（HSA-CAPN2）连接的CAPN2酶可激活的近红外肽传感器。在使用A549-Luc细胞的体外实验中观察到HSA-CAPN2的细胞内定位和强烈恢复的荧光信号，并且信号恢复受到ALLN（CAPN2抑制剂）的抑制。使用A549-Luc细胞异种移植小鼠进行的体内分布和信号恢复评估显示，HSA-CAPN2积累在肿瘤区域并产生高荧光信号恢复。组织清晰后，使用单平面照明显微镜的三维重建图像可视化了HSA-CAPN2在肿瘤中的定位。此外，ALLN预处理对HSA-CAPN2的信号恢复显示出显着的抑制作用，并且该抑制作用是由于在基因和蛋白质水平上CAPN2的下调，随后是Ca2 +水平的降低而诱导的。总体而言，结果证明了HSA-CAPN2作为富含CAPN2的癌症传感器的潜力。组织清晰后，使用单平面照明显微镜的三维重建图像可视化了HSA-CAPN2在肿瘤中的定位。此外，ALLN预处理对HSA-CAPN2的信号恢复显示出显着的抑制作用，并且该抑制作用是由于在基因和蛋白质水平上CAPN2的下调，随后是Ca2 +水平的降低而诱导的。总体而言，结果证明了HSA-CAPN2作为富含CAPN2的癌症传感器的潜力。组织清晰后，使用单平面照明显微镜的三维重建图像可视化了HSA-CAPN2在肿瘤中的定位。此外，ALLN预处理对HSA-CAPN2的信号恢复显示出显着的抑制作用，并且该抑制作用是由于在基因和蛋白质水平上CAPN2的下调，随后是Ca2 +水平的降低而诱导的。总体而言，结果证明了HSA-CAPN2作为富含CAPN2的癌症传感器的潜力。