Lung adenocarcinoma and squamous cell carcinoma difficult for immunohistochemical diagnosis can be distinguished by lipid profile.

In patients with unresectable non-small cell lung cancer, histological diagnosis is frequently based on small biopsy specimens unsuitable for histological diagnosis when they are severely crushed and do not retain their morphology. Therefore, establishing a novel diagnostic method independent of tissue morphology or conventional immunohistochemistry (IHC) markers is required. We analyzed the lipid profiles of resected primary lung adenocarcinoma (ADC) and squamous cell carcinoma (SQCC) specimens using liquid chromatography-tandem mass spectrometry. The specimens of 26 ADC and 18 SQCC cases were evenly assigned to the discovery and validation cohorts. Non-target screening on the discovery cohort identified 96 and 13 lipid peaks abundant in ADC and SQCC, respectively. Among these 109 lipid peaks, six and six lipid peaks in ADC and SQCC showed reproducibility in target screening on the validation cohort. Finally, we selected three and four positive lipid markers for ADC and SQCC, demonstrating high discrimination abilities. In cases difficult to diagnose by IHC staining, [cardiolipin(18:2_18:2_18:2_18:2)-H]- and [triglyceride(18:1_17:1_18:1) + NH4]+ showed the excellent diagnostic ability for ADC (sensitivity: 1.00, specificity: 0.89, accuracy: 0.93) and SQCC (sensitivity: 0.89, specificity: 0.83, accuracy: 0.87), respectively. These novel candidate lipid markers may contribute to a more accurate diagnosis and subsequent treatment strategy for unresectable NSCLC.

UBL3 Interacts with Alpha-Synuclein in Cells and the Interaction Is Downregulated by the EGFR Pathway Inhibitor Osimertinib.

Ubiquitin-like 3 (UBL3) acts as a post-translational modification (PTM) factor and regulates protein sorting into small extracellular vesicles (sEVs). sEVs have been reported as vectors for the pathology propagation of neurodegenerative diseases, such as α-synucleinopathies. Alpha-synuclein (α-syn) has been widely studied for its involvement in α-synucleinopathies. However, it is still unknown whether UBL3 interacts with α-syn, and is influenced by drugs or compounds. In this study, we investigated the interaction between UBL3 and α-syn, and any ensuing possible functional and pathological implications. We found that UBL3 can interact with α-syn by the Gaussia princeps based split luciferase complementation assay in cells and immunoprecipitation, while cysteine residues at its C-terminal, which are considered important as PTM factors for UBL3, were not essential for the interaction. The interaction was upregulated by 1-methyl-4-phenylpyridinium exposure. In drug screen results, the interaction was significantly downregulated by the treatment of osimertinib. These results suggest that UBL3 interacts with α-syn in cells and is significantly downregulated by epidermal growth factor receptor (EGFR) pathway inhibitor osimertinib. Therefore, the UBL3 pathway may be a new therapeutic target for α-synucleinopathies in the future.

Detection of Distinct Distributions of Acetaminophen and Acetaminophen-Cysteine in Kidneys up to 10 µm Resolution and Identification of a Novel Acetaminophen Metabolite Using an AP-MALDI Imaging Mass Microscope.

Drug distribution studies in tissue are crucial for understanding the pharmacokinetics and potential toxicity of drugs. Recently, matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) has gained attention for drug distribution studies due to its high sensitivity, label-free nature, and ability to distinguish between parent drugs, their metabolites, and endogenous molecules. Despite these advantages, achieving high spatial resolution in drug imaging is challenging. Importantly, many drugs and metabolites are rarely detectable by conventional vacuum MALDI-MSI because of their poor ionization efficiency. It has been reported that acetaminophen (APAP) and one of its major metabolites, APAP-Cysteine (APAP-CYS), cannot be detected by vacuum MALDI-MSI without derivatization. In this context, we showed the distribution of both APAP and APAP-CYS in kidneys at high spatial resolution (25 and 10 µm) by employing an atmospheric pressure-MALDI imaging mass microscope without derivatization. APAP was highly accumulated in the renal pelvis 1 h after drug administration, while APAP-CYS exhibited characteristic distributions in the outer medulla and renal pelvis at both 30 min and 1 h after administration. Interestingly, cluster-like distributions of APAP and APAP-CYS were observed in the renal pelvis at 10 µm spatial resolution. Additionally, a novel APAP metabolite, tentatively coined as APAP-butyl sulfate (APAP-BS), was identified in the kidney, brain, and liver by combining MSI and tandem MSI. For the first time, our study revealed differential distributions of APAP, APAP-CYS (in kidneys), and APAP-BS (in kidney, brain, and liver) and is believed to enhance the understanding of the pharmacokinetics and potential nephrotoxicity of this drug.

Lipidomics-based tissue heterogeneity in specimens of luminal breast cancer revealed by clustering analysis of mass spectrometry imaging: A preliminary study.

Cancer tissues reflect a greater number of pathological characteristics of cancer compared to cancer cells, so the evaluation of cancer tissues can be effective in determining cancer treatment strategies. Mass spectrometry imaging (MSI) can evaluate cancer tissues and even identify molecules while preserving spatial information. Cluster analysis of cancer tissues' MSI data is currently used to evaluate the phenotype heterogeneity of the tissues. Interestingly, it has been reported that phenotype heterogeneity does not always coincide with genotype heterogeneity in HER2-positive breast cancer. We thus investigated the phenotype heterogeneity of luminal breast cancer, which is generally known to have few gene mutations. As a result, we identified phenotype heterogeneity based on lipidomics in luminal breast cancer tissues. Clusters were composed of phosphatidylcholine (PC), triglycerides (TG), phosphatidylethanolamine, sphingomyelin, and ceramide. It was found that mainly the proportion of PC and TG correlated with the proportion of cancer and stroma on HE images. Furthermore, the number of carbons in these lipid class varied from cluster to cluster. This was consistent with the fact that enzymes that synthesize long-chain fatty acids are increased through cancer metabolism. It was then thought that clusters containing PCs with high carbon counts might reflect high malignancy. These results indicate that lipidomics-based phenotype heterogeneity could potentially be used to classify cancer for which genetic analysis alone is insufficient for classification.

A New Potential Therapeutic Target for Cancer in Ubiquitin-Like Proteins-UBL3.

Ubiquitin-like proteins (Ubls) are involved in a variety of biological processes through the modification of proteins. Dysregulation of Ubl modifications is associated with various diseases, especially cancer. Ubiquitin-like protein 3 (UBL3), a type of Ubl, was revealed to be a key factor in the process of small extracellular vesicle (sEV) protein sorting and major histocompatibility complex class II ubiquitination. A variety of sEV proteins that affects cancer properties has been found to interact with UBL3. An increasing number of studies has implied that UBL3 expression affects cancer cell growth and cancer prognosis. In this review, we provide an overview of the relationship between various Ubls and cancers. We mainly introduce UBL3 and its functions and summarize the current findings of UBL3 and examine its potential as a therapeutic target in cancers.