Measuring the lactate-to-creatine ratio via 1H NMR spectroscopy can be used to noninvasively evaluate apoptosis in glioma cells after X-ray irradiation.

Abstract

BACKGROUND:

Radiotherapy is among the commonly applied treatment options for glioma, which is one of the most common types of primary brain tumor. To evaluate the effect of radiotherapy noninvasively, it is vital for oncologists to monitor the effects of X-ray irradiation on glioma cells. Preliminary research had showed that PKC-ι expression correlates with tumor cell apoptosis induced by X-ray irradiation. It is also believed that the lactate-to-creatine (Lac/Cr) ratio can be used as a biomarker to evaluate apoptosis in glioma cells after X-ray irradiation. In this study, we evaluated the relationships between the Lac/Cr ratio, apoptotic rate, and protein kinase C iota (PKC-ι) expression in glioma cells.

METHODS:

Cells of the glioma cell lines C6 and U251 were randomly divided into 4 groups, with every group exposed to X-ray irradiation at 0, 1, 5, 10 and 15 Gy. Single cell gel electrophoresis (SCGE) was conducted to evaluate the DNA damage. Flow cytometry was performed to measure the cell cycle blockage and apoptotic rates. Western blot analysis was used to detect the phosphorylated PKC-ι (p-PKC-ι) level. 1H NMR spectroscopy was employed to determine the Lac/Cr ratio.

RESULTS:

The DNA damage increased in a radiation dose-dependent manner (p < 0.05). With the increase in X-ray irradiation, the apoptotic rate also increased (C6, p < 0.01; U251, p < 0.05), and the p-PKC-ι level decreased (C6, p < 0.01; U251, p < 0.05). The p-PKC-ι level negatively correlated with apoptosis, whereas the Lac/Cr ratio positively correlated with the p-PKC-ι level.

CONCLUSION:

The Lac/Cr ratio decreases with an increase in X-ray irradiation and thus can be used as a biomarker to reflect the effects of X-ray irradiation in glioma cells.

• Authors: Hongxia Li, Yi Cui, Fuyan Li, Wenqi Shi, Wenjing Gao, Xiao Wang, Qingshi Zeng
• Journal: Cellular & molecular biology letters (Cell Mol Biol Lett) Vol. 23 Pg. 27 ( 2018) ISSN: 1689-1392 [Electronic] England
• PMID: 29946338 (Publication Type: Journal Article)

Chemical References

• Isoenzymes
• Lactic Acid
• Protein Kinase C
• protein kinase C lambda
• Creatine

Topics

• Apoptosis (radiation effects)
• Brain Neoplasms (metabolism, pathology)
• Cell Cycle Checkpoints (radiation effects)
• Cell Line, Tumor
• Creatine (analysis)
• DNA Damage (radiation effects)
• Electrophoresis, Gel, Pulsed-Field
• Glioma (metabolism, pathology)
• Humans
• Isoenzymes (metabolism)
• Lactic Acid (analysis)
• Magnetic Resonance Spectroscopy
• Protein Kinase C (metabolism)
• Single-Cell Analysis
• X-Rays