[The connection of miR-21 and miR-155 with regulation of 15-HPGDH mRNA in human breast cancer cells]. / Sviaz' miR-21 i miR-155 s reguliatsiei mRNK 15-HPGD v kletkakh raka molochnoi zhelezy cheloveka.

Breast cancer is the most frequent cancer and the leading cause of cancer-related deaths in women worldwide. We determined the expression of COX2, COX1, 15-HPGDH mRNA and miRNAs (miR-21, miR-155) in three estrogen positive human breast cancer cell lines (MCF-7, BT-474, ZR-75-1). According to the results of three independent experiments the amount of COX1 and COX2 mRNA was significantly higher in the ZR-75-1 than in MCF-7 and BT-474 cells. Levels of total 15-HPGDH; functional 15-HPGDH mRNA in BT-474 cell line were lower than in MCF-7 and ZR-75-1 ones. The synthesis of 15-HPGDH enzyme in BT-474 line was blocked at the nuclear immature pre-mRNA processing level. miR-155 expression level was significantly lower than miR-21 in breast cancer cell lines. Correlations between the dysregulation of miR-21, miR-155 and 15-HPGDH, COX-1, COX-2 mRNA were identified. Expression of miR-21 was high in MCF-7, ZR-75-1 and BT-474 cell lines. Our results show that miR-21 and miR-155 regulate activity of several genes in cancer cells, their effect on the individual genes was in some cases cumulative. Based on our results, we concluded that miR-21, miR-155 suppress the work of tumor suppressor gene 15-HPGDH and induce potential oncogene COX-2 that promotes cell malignancy and metastasis of breast cancer.

[Production of active oxygen by neutrophils in patients with cancer of the esophagus and stomach before and after surgical interventions].

The state of the oxygen-depended antimicrobial activity of neutrophils on oncologic patients was studied. Production of active oxygen by non-activated and activated neutrophils of peripheral blood from 19 patients (the average age of 56 years, 16 males and 3 females) with esophageal cancer and cancer of the stomach and metastasis to the esophagus was recorded by chemiluminescence before and after surgical interventions (transpleural gastrectomy, Lewis type operation) on the 1st, 3rd and 7th days after the operations. The oxygen-depended antimicrobial activity of the neutrophils was investigated by their ability to produce active oxygen when incubated with opsonized zymosan and N-formyl-methionyl-leucyl-phenylalanine. Luminol chemiluminescence recorded the whole pool of active oxygen and showed the summary activity of myeloperoxidase and NADPH-oxidase, while luceginin chemiluminescence measured formation of superoxide anion radical (*O(-)2) and evaluated the activity of NADPH-oxidase. The results showed that the procedure provided estimation of the functional state of the neutrophil leukocytes and their ability to produce active oxygen. Impairment of the myeloperoxidase- and NADPH-depended production of active oxygen by non-activated and activated neutrophils observed before operations resulted in altered synthesis of active oxygen after the surgery. This is one of the leading factors of the infection development in the end. Detection of the myeloperoxidase- and NADPH-depended production of active oxygen could be of help in revealing the groups of risk among patients at the stage of the preoperative examination and serve as a prognostic factor of the development of severe infectious complications during the postoperative period.