Morphological features of mitochondria isolated from tumor and apparently healthy tissue of the rectum in patients depending on the presence of metastases

Aim. To examine the ultrastructural characteristics of mitochondria isolated from rectal adenocarcinoma tissue and apparently healthy tissue along the tumor resection line in patients of both sexes, depending on the presence or absence of metastases.
Materials and methods. The study encompassed the analysis of 28 patients diagnosed with rectal cancer, classified as T2–3N0M0 and T2–3N1–3M1, with tumor differentiation grade G2. Mitochondria were isolated from tumor and intestinal tissue cells via differential centrifugation. The mitochondrial suspension was then placed in a fixative solution containing formaldehyde and glutaraldehyde, followed by immersion in pure Epon-812 resin (SPI Inc., USA). The resin was allowed to cure for a period of 72 hours at a temperature of 70° C. Standard methodologies were employed to prepare the sections, which were then examined using a Jeol JEM-1011 electron microscope (JEOL Inc., Japan). The mitochondrial perimeter on images obtained by electron microscopy was determined using the Fiji program.
Results. A comprehensive ultrastructural study and statistical analysis of the perimeter size of mitochondria isolated from rectal adenocarcinoma in patients of both sexes were conducted. The results indicated that there were no statistically significant intergroup differences in mitochondrial size, categorized as conditionally small (0–1 μm), medium (1–2 μm), and large (>2 μm), depending on the presence or absence of metastases. In contrast to the tumor tissue, in apparently healthy tissue along the rectal resection line, the proportion of mitochondria with a perimeter of ˃ 2 μm, characterized by the most pronounced dysfunction, decreased by 3.6 times in women and by 4.8 times in men without metastases compared to the indicators in all patients with metastases (p < 0.05).
Conclusion. The significance of differences in the perimeter dimensions of mitochondria isolated from apparently healthy tissue at the resection line of rectal adenocarcinoma, regardless of gender differences in patients, indicated the possibility of a morphofunctional relationship between processes occurring at the ultrastructural mitochondrial level and metastasis of rectal cancer.

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