Cytochrome P450 content in primary tumors and liver metastases of patients with metastatic colorectal cancer.

AIM: To determine the content of low-spin form of cytochrome P450 in primary tumors and liver metastases of the patients with metastatic colorectal cancer (mCRC) and and assess its prognostic significance. MATERIALS AND METHODS: The levels of the oxidized and low-spin forms of cytochrome P450 in the tissues of patients with mCRC were studied by electron paramagnetic resonance. To detect CYP 1A2 and CYP 1B1 isoforms, Western blot analysis was used. The activity of metalloprotreinases was studied by gelatine zymography. RESULTS: In the liver metastases and tissues adjacent to metastasis, the levels of low-spin forms of cytochrome P450 are lower than in the samples of conventionally normal liver tissue. Western blot analysis revealed that low-spin form of cytochrome P450 in primary tumors and liver metastases detected by electron paramagnetic resonance is attributed largely to CYP 1B1 isoform. The content of low-spin form of cytochrome P450 inversely correlated with the the activity of gelatinases (matrix metalloproteinase-2 and -9). The survival of patients with high levels of the low-spin form of cytochrome P450 in tumor tissues was higher than that of patients with low levels of the enzyme (105 months vs 61 months). CONCLUSION: In the primary tumors and liver metastases of patients with mCRC, the content of the low-spin form of cytochrome P450 decreased, which correlated inversely with patient's survival.

Tumor microenvironment changes tumor cell sensitivity to action of energy metabolism modifiers.

BACKGROUND: Taking into account differences in the bioenergetics between malignant and normal cells a search of antitumor drugs among the modifiers of tumor metabolism has a reasonable excuse. Earlier it was found that the cytotoxic/cytostatic action of sodium dichloroacetate (DCA) against Lewis lung carcinoma (LLC) cells in vitro was enhanced in the case of its combination with metformin (MTF). AIM: To study the antitumor action of DCA in combination with MTF against LLC in vivo. MATERIALS AND METHODS: LLC/R9, a low metastatic variant of LLC cells, was used. LLC/R9 bearing mice were treated with MTF (at a total dose 0.15 g/kg b.w.) alone or in combination with DCA (at a total dose of 0.75 g/kg b.w.). LLC/R9 growth kinetics and the primary tumor growth and metastasis indices on the 23rd day after tumor cell inoculation were evaluated by routine procedures. The state of the electron transport chain of mitochondria in tumor cells was studied using electron paramagnetic resonance. The content of lactate and glucose in blood plasma from mice was measured by enzymatic methods using biochemical analyzer. The number of tumor-associated macrophages (TAMs) and their distribution by M1/M2 phenotype were estimated by flow cytometry using antibodies against CD68 and CD206. RESULTS: In LLC/R9-bearing mice treated with DCA in combination with MTF, tumor growth and metastasis indices, as well as circulating glucose and lactate levels were not significantly different from those in the control group. The level of nitrosylation of non-heme and heme proteins and the content of iron-sulfur centers in the mitochondria of tumor cells in LLC/R9-bearing mice administered with DCA in combination with MTF did not also differ from the corresponding indices in control. Instead, in tumors treated with MTF alone and in combination with DCA the total CD68+ TAMs count was almost 27% (p < 0.05) and 43% lower (p < 0.05) correspondingly than that in control, but this decrease was not accompanied by redistribution of CD68+/CD206+ and CD68+/D206- subsets. CONCLUSION: DCA in combination with MTF, at least in doses applied, did not affect LLC/R9 growth and metastasis in vivo. The complete absence of an antitumor effect of DCA in combination with MTF was simultaneously associated with the absence of significant changes in the functional state of electron transport chain of mitochondria in tumor cells, circulating glucose and lactate levels, and the decrease of the TAMs amount in tumors. It suggests that the antitumor activity of DCA and MTF could be determined by both their local effects within a tumor and their multiple systemic impacts.

Functions of tumor-associated macrophages and macrophages residing in remote anatomical niches in Ehrlich carcinoma bearing mice.

BACKGROUND: The impact of growing tumor on polarization and functions of tumor-associated macrophages is well known while its influence on residential macrophages occupying different anatomical niches reminds to be elucidated. AIM: To study changes in polarization and functions of macrophages isolated from discrete anatomical niches in tumor-bearing mice at different stages of tumor growth. MATERIALS AND METHODS: Ehrlich carcinoma was transplanted intramuscularly to Balb/c male mice. On days 7, 14, 21 and 28 after tumor transplantation, macrophages from tumor tissue, peritoneal cavity and spleen were isolated and analyzed. Nitric oxide production was measured by standard Griess reaction, arginase activity was determined by the measurement of urea, reactive oxygen species production was checked using NBT dye reduction assay and electron paramagnetic resonance spectroscopy, cytotoxic activity was estimated in MTT-assay. RESULTS: Independently of their localization in different anatomic niches, macrophages in mice with transplanted Ehrlich carcinoma gradually lose their tumoricidal activities while arginase activity is upregulated. This indicates the shift of polarization from M1-like towards M2-like phenotype. CONCLUSION: Our findings demonstrated that growing tumor could be able to subvert functioning of macrophages at the systemic level.

[Effect of vitamin A and hormones on the hormonal sensitivity of DMBA-induced mammary tumors in rats]. / Vliianie vitamina A i gormonov na gormonochuvstvitel'nost' opukholei molochnoi zhelezy, indutsirovannykh DMBA, u krys.

The treatment of rats with DMBA-induced mammary tumours with vitamin A and hormones in the cyclic regime increases the lifetime of animals, decreases both the tumour growth rate and increases the degree of their differentiation. The treatment with vitamin A alone and in combination with hormones lowers the level of estradiol and progesterone receptors in the rat mammary tumours. The high frequency of receptor-positive tumours and high level of estradiol and progesterone receptors in them were observed under the influence of hormones alone in the cyclic regime.

[Estradiol and progesterone receptors in DMBA-induced mammary neoplasms in rats under cyclic hormonal exposures]. / Retseptory éstradiola i progesterona v indutsirovannykh DMBA opukholiakh molochnoi zhelezy u krys pri tsiklicheskikh gormonal'nykh vozdeistviiakh.

Hormones in physiological doses and under cyclic regime were injected to rats with DMBA-induced mammary tumours. It is demonstrated that 17-alpha-hydroxyprogesterone capronate (HPC) alone administered once every 6 days reduces estradiol receptor (ER) and progesterone receptor (PR) levels and the frequency of R+ tumours. Under the influence of a successive use of HPC and testosterone (TS) the level of PR and the frequency of PR+ tumours were reduced. A high level of ER and PR and a high frequency of R+ tumours were observed after a successive administration of insulin, prednisolone, HPC and TS. All the variants of hormonal influences resulted in an increased life duration of animals, a reduced growth rate, and an increased degree of mammary tumour differentiation.

[Effect of serum polyamine oxidase on normal and tumor cells]. / Vliianie syvorotochnoi poliaminoksidazy na normal'nye i opukholevye kletki.

Serum polyamine oxidase was studied for its effect on normal and transformed fibroblasts, Erlich carcinoma, Zaidela hepatoma and experimental Svec leukaemia cells as well as on K-562 human leukaemia cells. It is found that the cell death was induced by dialdehydes generated by polyamine deamination. Autoradiographically it was shown that dialdehydes cross-link the cell plasma membranes. It is suggested that serum polyamine oxidase is one of the factors responsible for the phenomenon of constitutional resistance which provides subsequent realization of the long-term immune defence.