Insulin resistance, its consequences for the clinical course of the disease, and possibilities of correction in endometrial cancer.

OBJECTIVES: To study the frequency of insulin resistance (IR) in endometrial cancer patients, its relation to the clinical course of the disease and DNA damage, and to evaluate possible approaches to the pharmacological correction of IR in the patients studied. METHODS: The signs of insulin resistance syndrome and its association with the clinical and pathological features of the disease and DNA damage in somatic cells (micronucleus frequency in peripheral blood lymphocytes) and endometrial normal and tumor tissue (alkaline unwinding) were determined in 99 endometrial cancer patients. RESULTS: The frequency of insulin resistance syndrome counted on the basis of fasting plasma glucose and insulin concentrations according to Duncan et al. is equal to 0.35 (95% CI 0.24-0.46), or 35%, in endometrial cancer patients who do not have a history of diabetes mellitus. Patients with well- or moderately differentiated endometrial adenocarcinomas (mostly type I) had statistically significantly higher basal and stimulated plasma insulin and C-peptide concentrations than patients with poorly differentiated endometrial adenocarcinomas or rarely encountered tumors of the endometrium (primarily type II). Interestingly, the level of fasting insulinemia positively correlates with disease stage and with local and regional tumor dissemination only in the group of patients with well- or moderately differentiated endometrial adenocarcinomas. On the other hand, hyperinsulinemia and other hormonal-metabolic disturbances typical of insulin resistance syndrome do not increase the probability of DNA damage of somatic cells (according to the data of micronucleus test). In addition, no association between hormonal-metabolic disturbances and the degree of DNA unwinding in tumor and visually unchanged endometrium was found. CONCLUSION: Thus, insulin resistance/hyperinsulinemia is associated with a more aggressive course of the disease in certain groups of the patients but--in contrast to excessive estrogenic stimulation--does not result in increased genotoxic damage in tumor and normal tissues. The data obtained once more confirm the need for treatment and prevention measures aimed at correcting hormonal-metabolic disturbances in endometrial cancer patients and groups at risk of this disease. Such an approach might include use of antidiabetic biguanides, thiazolidinediones (glitazones), and statins.

[Genetic polymorphism of steroidogenic enzymes and steroid receptor level in tumors of the reproductive system]. / Geneticheskii polimorfizm fermentov steroidogeneza i soderzhanie retseptorov v opukholiakh reproduktivnoi sistemy.

The strategy of therapy and prognosis of reproductive system neoplasia generally depend on the steroid receptor status of tumor. The causes of formation of steroid receptor-free tumors are to be investigated. The genetic polymorphism of CYP19 (aromatase), CYP17 (17-hydroxylase; 17,20-lyase), CYP1B1 (4-estrogen hydroxylase) and COMT (catechol-O-methyl transferase) was studied in a total of 254 patients with breast and endometrial cancer, with particular reference to the association of certain polymorphisms and receptor status of tumor. It was found that the lack of estrogen receptor (ER) in breast tumor was due to a deficit in the A3A6 allele (p(0.01), while the absence of progesterone receptors was associated with a lower incidence of the A1A1 and A1A2 variants (p = 0.022) of tetranucleotide repeats in the CYP19 gene. In the same patients, receptor-negative tumors occurred more often (p = 0.032) than in combinations of higher level of 4-hydroxylase estradiol of S-allele in position 48 (Gly/Arg) of the CYP1B1 gene. Moreover, endometrial carcinoma patients tended to reveal (p = 0.058) an increased ratio of A6A7-CYP19 to allele A1-containing variant. No other distinctions between R(+) and R(-) tumors were identified. It is suggested that peculiar polymorphisms of steroidogenic enzymes may moderately influence the genesis of R(-) neoplasms which may be associated with either the rate of estrogen biosynthesis or, as in the case of CYP1B1, with formation of genotoxic derivatives of estrogens. The latter point is to be investigated further.

Expression of estrogen receptors-alpha and -beta in primary breast neoplasms and tumors exposed to neoadjuvant hormonal therapy.

We studied the content and expression of mRNA for estrogen receptors-alpha and -beta in breast tumors before and after 3-month neoadjuvant hormone therapy with antiestrogen tamoxifen and/or aromatase inhibitors. Expression of estrogen receptors-alpha and -beta was most often detected in ER+PR+ tumors and most significantly decreased in these neoplasms after exemestane therapy. Immunocytochemical and radioligand assays showed that tamoxifen and anastrozole have little effect on the number of estrogen receptors-alpha. The number of progesterone receptors in tumors decreased by the end of anastrozole therapy. Estrogen receptors-beta were immunocytochemically revealed in 50% primary breast tumors. Anastrozole slightly decreased, while tamoxifen increased the incidence of these receptors. Interruption of signaling through estrogen receptors and suppression of estrogen biosynthesis had different effects on the receptor status of neoplasms and distribution of estrogen receptors-alpha and -beta.

Expression of estrogen receptors-beta and aromatase activity in primary mammary gland tumors.

Expression of estrogen receptors alpha and beta was studied by the PCR method in 22 primary receptor-positive or receptor-negative breast carcinomas obtained during surgical intervention from patients aged 41-77 years and activity of aromatase in the same specimens was evaluated by the formation of tritiated water from labeled androgen precursor. Expression of estrogen receptors alpha and beta was more often detected in receptor-positive tumors characterized by lower aromatase activity. The authors conclude that the intensity of local production of estrogens can be one of the regulators of their expression, limiting this expression in case of more active production of estrogen in the tumor. On the other hand, there were no differences in the expression of estrogen beta-receptor gene or in detection of this receptor by immunocytochemical method in primary tumors lacking one of these receptors, and hence, this form of estrogen receptors is less involved in induction of progesterone receptors than alpha-receptors.

Aromatase (CYP19) expression in tumor-infiltrating lymphocytes and blood mononuclears.

PURPOSE: To clarify the role of lymphocytes as a possible source of estrogens. METHODS: In the present study, lymphocytes were isolated from 11 surgical samples of breast cancer after tumor enzyme digestion and Ficoll/Verographine procedure. Simultaneously, using the latter procedure, mononuclears were separated from the blood of 15 female volunteers. RESULTS: Expression of the aromatase (CYP19) gene was readily demonstrated by standard RT-PCR in blood mononuclears cultivated in the presence of 10% fetal calf serum for 48 h. In the tumor-infiltrating lymphocytes (TIL) of breast cancer patients, CYP19 expression was discovered only with the aid of nested PCR. CONCLUSIONS: The data obtained suggest that aromatase gene expression is presented in TIL at a rather low level. Nevertheless, this can have some functional significance for the estrogen-dependent growth of breast cancer tissue.

[Aromatase (estrogen synthetase) gene expression in human leukocytes]. / Ekspressiia gena aromatazy (éstrogensintetazy) v leikotsitakh cheloveka.

Extragonadal aromatization plays an important role in many physiological and pathological conditions. It has been found that incubation of the peripheral blood mononuclears in the RPMI-1640 medium with 10% fetal calf serum during 48 hrs is able to induce the aromatase gene expression. The latter did not occur in 11 samples of mononuclears of the intra-tissue leukocyte infiltration which finding needs further investigation. The data obtained suggest that the possibility of the aromatase gene induction in leukocytes is associated with the cellular fraction capable of the substrate adhesion.

[Effect of tobacco smoke on the level of estrogens and DNA in the rat uterus]. / Vliianie tabachnogo dyma na soderzhanie éstrogenov i DNK v matke krys.

Tobacco smoke induced no changes in the rat uterus weight or in oestrus cycle but decreased estradiol (E2) concentration in the uterus tissue and increased and later decreased the proliferation index and percentage of the cells in the S-phase. The data obtained suggest a phasic character of changes in the reproductive system under the effect of tobacco smoke and corroborate the concept of the role of smoking in the shifting the type of hormonal carcinogenesis from promotional to genotoxic one.

Ability of lymphocytes infiltrating breast-cancer tissue to convert androstenedione.

Lymphocytes were isolated from 43 surgical samples of breast cancer after tumor enzyme digestion and Ficoll/Verographine procedure. In all, 23 specimens from lymphocytic-tissue infiltrates were analyzed (in some cases, material from 2 or 3 patients was combined). The ability of tumor-infiltrating lymphocytes (TIL) to convert androstenedione was demonstrated, as evaluated by hard-water release from the androgenic precursor 3H-1beta-androstenedione. In material obtained from menopausal women this ability was higher than in the women of reproductive age. A positive correlation was revealed between the level of androstenedione conversion in TIL and aromatase activity in tumor tissue, while no correlation was shown between androstenedione conversion in TIL and percentage of tumor cells in lymphocytic suspension. The data obtained suggest that factors secreted by a neoplasm are able to induce aromatase gene expression in TIL.

[Metabolism of the androgenic precursor androstenedione and effects of aromatase inhibitors in cultured blood lymphocytes]. / Metabolism androgennogo predshestvennika androstendiona i vliianie na nego ingibitorov aromatazy v kul'tiviruemykh limfotsitakh krovi.

Blood lymphocytes from 26 women were cultivated in RPMI-1640 for 72 hrs with or without dexamethasone, dbcAMP, and TPA. Androstenedione conversion was most often activated by the dbcAMP, then by Dex and TPA. Response to dbcAMP was most obvious in women under 50, whereas response to Dex--in women over 50. Aromatase inhibitor fadrosol displayed a tendency towards prevention of the activation of androstenedione conversion in cultivated lymphocytes. A possibility of aromatase gene induction in cultivated lymphocytes cannot be completely excluded and demands further investigation with the aid of molecular-genetic methods.

[Correlation of lymphocytic infiltration of tumor tissue with the hormonal and metabolic state in patients with breast cancer]. / Sopostavlenie limfotsitarnoi infil'tratsii opukholevoi tkani s gormonal'no-metabolicheskim statusom u bol'nykh rakom molochnoi zhelezy.

Lymphocyte infiltration of tumor was studied vis-a-vis hormone metabolic status, tumor tissue hormone sensitivity and tobacco smoking, in 113 breast cancer patients, aged 25-77. On the average, no correlation was established between degree of lymphocyte infiltration in breast tumor and age and menopause onset. In smoking menopausal patients, lymphocyte infiltration was found to be higher than in non-smokers (p < 0.05). There was a direct correlation between the rate of lymphocyte infiltration and the level of progesterone receptors in tumor. Some subgroups displayed a direct correlation between infiltration and sex-binding globulin, cholesterol, luteinizing hormone in blood, and lean body mass. It was matched by an inverse correlation between lymphocyte infiltration and blood-thyroid hormone concentration, urine catecholamines and free cortisol excretion and fat/lean body mass ratio. Considering the abovesaid as well as the lymphocyte ability to perform the dual function of immunocytes and hormonocytes, it is suggested that the results may be used in both the study of lymphocyte infiltration and research in means of its control.