IsoTopics™ – October 2019

Duan, Q.; Li, D.; Xiong, L.; et al.

Small cell lung cancer (SCLC) is an aggressive type of lung cancer. Due to the poor survival rate of SCLC patients, efforts to better understand the mechanisms underlying tumorigenesis and metastasis are sought. 

Galvez, L.; Rusz, M.; Schwaiger-Haber, M.; et al.

Oxaliplatin is a chemotherapy drug administered to aid treatment of metastatic colorectal cancer. Despite its regularity, the impact of this metallodrug on drug uptake/distribution and the metabolome remains unclear. 

Holwerda, A.M.; Paulussen, K.J.M.; Overkamp, M.; et al.

Anabolic resistance is considered to play a key role in the progression of sarcopenia in older adults. Resistance exercise potently increases muscle protein synthesis, with post-exercise recovery further enhanced by the ingestion of >40 g of protein. Since older individuals may not be able to ingest such large doses of protein, van Loon and colleagues investigated the effect of co-ingesting 15 g of protein with or without added leucine.

Al-Dirbashi, O.Y.; Alfadhel, M.; Al-Thihli, K.; et al.

Propionyl-CoA metabolic defects require early diagnosis in neonates to limit life-threatening complications. Regrettably, a specific marker for the prognosis/monitoring of propionic acidemia (PA) has yet to be proposed. Al-Dirbashi et al. therefore aimed to evaluate the potential of methylcitric acid (MCA) and its ratio to citric acid (CA) as markers of propionate metabolism disorders. The method quantified CA and MCA derivatives in patient DBS samples by RPLC-MRM/MS, with D₄ CA and D₃ MCA functioning as internal standards. Although further studies with larger patient cohorts are required, the novel results demonstrate that MCA and MCA/CA can serve as a potential biomarker for both PA and methylmalonic acidemia.

Jang, C.; Chen, L.; Rabinowitz, J.D.

Metabolomics and metabolism are two increasingly employed research endeavors. Given the advancements and the complimentary nature of these fields, Rabinowitz and colleagues herein review the analytical workflow (from sample handling to data analysis/interpretation) and best practices for both measuring/quantifying metabolites (in metabolomics) and tracing stable isotope labeling (in metabolism). Highlighted are four types of biological applications, with an eye into future metabolic research directions.