Lei Zhou

Derivatization-Mediated MALDI-MSI and CE-LIF for Collaborative Analysis of Monosaccharides in Endometrial Cancer Patients: From Pathological Tissues to Serum

Abnormal glucose metabolism has been identified as a key characteristic of tumorigenesis. Visualizing the levels of monosaccharides in the lesion tissues and bodies of cancer patients is conducive to uncovering patterns of glucose metabolic reprogramming and assisting in the early diagnosis of cancer. Consequently, based on 7-(diethylamino)coumarin-3-carbohydrazide (DCCH), which has mass spectrometry/optical dual-signal enhancement functionality, both an on-tissue derivatization strategy suitable for matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) analysis and an in-solution derivatization strategy for capillary electrophoresis/laser-induced fluorescence (CE-LIF) analysis have been developed. During the on-tissue derivatization reaction, the nonvolatile MALDI matrix, 2,5-dihydroxybenzoic acid, was innovatively adopted as a proton donor. This approach not only efficiently catalyzes the derivatization process but also significantly minimizes analyte redistribution, and a low-cost airbrush application can achieve satisfying in situ derivatization. For further addressing the issue of the coexistence of multiple conformational isomers in biosamples, a rapid and efficient CE-LIF method was proposed for the separation of five DCCH-labeled monosaccharides (including three conformational isomers) within 8 min. By focusing on endometrial cancer (EC), the synergy of DCCH-mediated MALDI-MSI and CE-LIF analysis successfully achieved high-resolution in situ visualization of an obvious depletion difference in monosaccharides across the focal areas (tumor tissues, peritumoral tissues, and paracancerous tissues), and a comparative analysis was conducted on the serum monosaccharide profiles between patients with EC and those with benign uterine diseases. These analyses yielded novel molecular-level evidence, thereby facilitating a deeper understanding of the monosaccharide metabolic abnormalities associated with EC.

Downregulated PRNP Facilitates Cell Proliferation and Invasion and Has Effect on the Immune Regulation in Ovarian Cancer

Background. Ovarian cancer (OC) seriously threatens women’s life. Ferroptosis plays an essential role in the initiation and development of OC. However, more molecular targets and mechanisms for ferroptosis in OC remain to be further elucidated. Methods. Several OC datasets were integrated in this study and three candidate genes including PRNP were further screened out as the ferroptosis-related gene which was differentially expressed in OC. Then, comprehensive evaluations concerning gene expression, clinical implication, in vitro validation of expression and functional experiments, prediction of downstream molecules and related signal pathways, and immune-modulating function were performed. Results. PRNP was the only downregulated ferroptosis-related gene with prognostic value for OC patients. The decreased mRNA and protein expression was verified in OC tissues and cell lines. PRNP was significantly correlated with cancer stages, primary therapy outcomes, and age in OC patients. Moreover, we found that overexpression of PRNP inhibited the proliferation, migration, and invasion ability of OC cells through in vitro experiments. PRNP was enriched to the Ras signaling pathway. PRNP expression was positively correlated with the infiltration of immune cells, such as mast cells, T effector memory cells, plasmacytoid DC cells, NK cells, and eosinophils. In addition, the association of PRNP with other immune signatures was also found. Conclusion. This study demonstrated for the first time showed that ferroptosis-related gene PRNP exerted a tumor suppressive role in OC and the aberrant expression and function of PRNP making it a potential novel biomarker for OC diagnosis, prognosis, and response to immunotherapies.