Small cell lung cancer (SCLC) accounts for ∼14% of total lung cancer, which is the worldwide leading cause of morbidity and mortality in cancer. Although SCLC can be treated with chemotherapy and radiotherapy, its 5 year survival rate is still below 7%. Therefore, it is essential to discover new molecules and elucidate the underlying mechanisms modulating the tumorigenesis and metastasis of SCLC for the unmet medical needs. The secreted form of A Disintegrin And Metalloproteinase 12 (ADAM12S) is highly expressed in SCLC and promotes the proliferation, migration, and invasion of SCLC cells. However, the underlying molecular mechanism is still elusive. Using stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative proteomics, we identify 82 ADAM12S-regulated proteins in an SCLC cell line. Our proteomics and biochemical analyses discover that ADAM12S overexpression elevates while ADAM12 knockdown reduces the rate-limiting enzyme hexokinase 1 (HK1) in glycolysis. Through bioinformatics analyses, genetic manipulation, and in vitro assays, we further reveal that ADAM12S promotes the proliferation, colony formation, migration, and invasion of SCLC cells through upregulating HK1. This work links ADAM12S to glucose metabolic pathways in its attribution to the tumorigenesis and metastasis of SCLC cells and might provide valuable information for the exploration of therapeutic intervention for SCLC.

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The research field in enzyme-based biotechnology urgently requires the discovery of new materials and methods with high-performance. Here we report that highly crystalline graphite dots (GDs) can modulate enzyme activities, and simultaneously allow for real-time measurements on enzyme kinetics in combination with mass spectrometry (MS). A well-defined modulation of lipolytic activities from inhibition to enhancement can be realized by selectively coupling lipase enzymes with GDs containing specific functional groups on the surface. As a unique feature of our approach, GDs in the enzyme reaction can simultaneously serve as a versatile matrix for rapid and sensitive detection of the residual enzyme substrate, the intermediate or final product of lipolytic digestion using MS technology. Therefore, enzyme kinetic data can be collected in a real-time, high-throughput format. This work provides a new platform for enzymological research in hybrid bio-catalytic processes with advanced nanotechnology.

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