Characteristic of Oral Squamous Cell Carcinoma Tissues Using Isotope Ratio Mass Spectrometry

Abstract

Overall prognosis for patients with oral squamous cell carcinomas (OSSC) is still unfavourable. However, there is a hope that a novel diagnostic method may establish better cancer biology characteristics. The aim of this study was to evaluate the isotope ratio of nitrogen and carbon in OSSC as compared to margin and healthy tissue. A total of 18 patients with OSSC were included in the study. Specimens collected covered: four tumour, four margin and two healthy oral mucosa samples. The samples underwent further procedures: lyophilization and isotope ratio mass spectrometry. Measurements of the ratio of stable isotopes of nitrogen 15N/14N and carbon 13C/12C were performed. It is noticeable that the highest average nitrogen concentration was observed in tumour 12 ± 0.4% and the lowest in healthy tissues 8 ± 0.9% (p < 0.00001). The highest average carbon content was observed in healthy tissues 57 ± 2.2% and the lowest in tumour 46 ± 1.3% (p < 0.00001). Moreover, values of 15N/14N expressed in delta notation were the highest in healthy tissues 9.84 ± 0.61 and the lowest in tumour 8.92 ± 0.58. Values of 13C/12C tended to be higher in tumour −22.2 ± 0.89 and the lowest in healthy tissues −23.7 ± 1.2. Tumour tissues differ in isotopic composition from tissues taken from margin and healthy tissues taken from distant oral mucosa.

Oral Cavity Cancer Tissues Differ in Isotopic Composition Depending on Location and Staging

“…The results were expressed in δ values. For carbon isotopes, we obtained the δ 13 C values by comparing the 13 C/ 12 C ratio in the analysed sample to the isotopic ratio 13 C/ 12 C ratio in the international PDB standard (Pee Dee Bee, Belemnitella Americana). For nitrogen isotopes, we used δ 15 N values related to the 15 N/ 14 N ratio of the standard, which is the atmospheric nitrogen.…”

“…Increases in δ15N values in hair showed the involvement of metabolic pathways leading to 15 N-enriched amino acids [8,9]. On the other hand, a higher body mass index was associated with an increase in δ 13 C in hair, reflecting the role of proteins in the diet [8]. δ 15 N in hair in patients with metabolic syndrome has been shown to increase while the value of δ13C decreases [10].…”

“…In breast cancer, using cultured cells with the propensity to be invasive, it has been found that metabolic changes appear in the urea cycle, glycolysis, lipid synthesis, and anaplerosis. Moreover, this metabolic shift was related to changes in isotopic composition; they were 15 N-depleted and 13 C-enriched [2,3]. In ovarian cancer, where the test material was plasma, researchers noted changes in Cu metabolism and lower δ 65 Cu values in plasma than in healthy controls [4].…”

“…In ovarian cancer, where the test material was plasma, researchers noted changes in Cu metabolism and lower δ 65 Cu values in plasma than in healthy controls [4]. A study of bladder cancer patients revealed that differences in the abundance of 15 N and 13 C can be used as potential markers to predict the recurrence of the disease. It was demonstrated that 13 C depletion in normal urothelium in patients with surgically treated bladder cancer is associated with shorter disease-free survival [5].…”

“…A study of bladder cancer patients revealed that differences in the abundance of 15 N and 13 C can be used as potential markers to predict the recurrence of the disease. It was demonstrated that 13 C depletion in normal urothelium in patients with surgically treated bladder cancer is associated with shorter disease-free survival [5].…”