Immunohistochemical analysis of NaPi2b protein (MX35 antigen) expression and subcellular localization in human normal and cancer tissues.

AIM: To study the expression profile of the NaPi2b protein and its localization in breast, ovarian and lung cancer cells in relation to normal tissues adjacent to tumor. METHODS: Immunohistochemical analysis with monoclonal antibody MX35 was applied for investigation of NaPi2b protein expression in breast, lung and ovarian carcinomas. Intensity of NaPi2b protein expression was calculated with semiquantitative scores. RESULTS: NaPi2b (MX35) protein expression was detected in breast, lung and ovarian cancer cells and adjacent normal tissue. We have shown that in contrast to ovarian tumors in breast and lung tumors NaPi2b expression is down regulated comparing to correspondent normal tissues. CONCLUSION: This study provides the data on the pattern of NaPi2b expression and cellular localization in breast, lung and ovarian cancers, which might be useful for understanding the mechanism of transport and maintenance of inorganic phosphate in cancer and normal cells, as well as for developing novel immunotherapeutic approaches based on MX35 monoclonal antibody.

Involvement of human beta-defensin-2 in proliferation of transformed cells of human cervix.

AIM: To evaluate the influence of human beta-defensin-2 (hBD-2) on viability and proliferation of cultured human epithelial cells and the patterns of hBD-2 expression in normal tissues and early-stage human cervical neoplasia in the relation to proliferative state of these cells. MATERIALS AND METHODS: The influence of recombinant hBD-2 on viability and proliferation of cultured cells of A431 and M-HeLa lines in vitro was performed by MTT-test, 3H-thymidine incorporation and cell counting techniques. Immunohistochemical analysis of expression of hBD-2 and PCNA in tissue samples (10 normal cases (control), 30 carcinomas of the cervix uteri: 15 - squamous cell carcinoma in situ (Stage 0), and 15 squamous cell carcinoma (Stage Ia)) was performed with the use of anti-hBD-2 and anti-PCNA-mAbs, respectively. RESULTS: We have revealed that hBD-2 significantly stimulated proliferation of A431 and M-HeLa cells in a concentration-dependent manner in the range of 0.1-2 microg/ml, whilst at higher concentrations (> 3-5 microg/ml) it negatively influenced cell viability. The results of immunohistochemical study have shown that malignant transformation of human cervical epithelium is accompanied by the increase of expression of hBD-2 and PCNA. However, the correlative analysis of the expression of the mentioned markers has revealed no relation between them. CONCLUSION: The effect of hBD-2 on viability and proliferation of cultured epithelial cells possesses a concentration-dependent character. Expression of hBD-2 is increased in early-stage cervical carcinoma.

The influence of maternal hypothyroidism and radioactive iodine on rat embryonal development: thyroid C-cells.

There have been no works devoted to the study of the influence of (131)I and maternal (131)I-induced hypothyroidism on the state of the C-cells in the thyroid gland of the developing embryos. A study was made on the effect of a dose of 150 microCi (131)I (0.5 Gy) leading to hypothyroidism in rats, on 35 mother rats and 168 newborn pups. The mother rats were divided into control and four treated groups which were injected with (131)I before pregnancy, on gestation days 5, 10, and 16, respectively. Immunohistochemically, the thyroid gland was examined for calcitonin-positive cells. Maternal hypothyroidism induced by (131)I leads to the development of hyperplasia and hyperthrophy of calcitonin-positive cells in the pups at the time of birth. The discovery of separate C-cells in the peripheral zone of the thyroid lobe may be evidence of an unbalance in the development of the medial and lateral source of the thyroid. There is a verifiable increase in the quantity of C-cells per 1 mm(2) field of the localization in the central zone of the gestation days 10 and 16 groups. This might be a compensatory mechanism for regulating the activity of the thyroid gland under induced hypothyroidism. Thus, in cases when there is a breakdown in the normal external regulation of the embryonic morphogenesis, a reduction in the level of maternal thyroid hormones and also direct exposure to (131)I, there is also a change in the foetus' internal regulatory systems. A change in C-cell system could lead to the appearance of endocrinological disorders later in life.

The influence of low doses 131I-induced maternal hypothyroidism on the development of rat embryos.

The aim of our research was to create and verify a model for studying the effects of a low dose of 131I and 131I-induced maternal hypothyroidism on the development of the embryo's thyroid gland and brain. The given dose (150 microCi) corresponds to the absorbed dose of 0.5 Gy. This dose is similar to that dose received by large numbers of the population of the C.I.S. regions polluted by radioactive isotopes of iodine as a result of the Chernobyl accident in 1985. Thirty-five female Wistar rats and their 168 newborn pups were used for observation. The females were divided into a control group and four experimental groups (each distinguished by the time of 131I injection: group I - no less than 12 days before mating; groups II, III and IV - on 5th, 10th and 16th days of gestation, respectively). In all the experimental female groups the incorporate dose of 131I led to hypothyroidism accompanied by a 43% reduction in the thyroxin level and by a nearly 8-fold increase in the TSH level. However, the influence of maternal hypothyroidism on the development of the thyroid gland and brain of embryos depends on the time when 131I took effect. There is a reduction in the weight of the newborns' brain and thyroid gland, total body mass. The hormonal status of the newborns' thyroid gland also changes. The proposed model will allow us to study many aspects of induced changes in the brain and thyroid gland of the embryos which develop under conditions of maternal hypothyroidism resulting from a low dose of 131I, administered at the critical times of development.

Immunohistochemical study of fibronectin and thyroglobulin in the thyroid gland of female rats after exposure to radioactive iodine.

The aim of this work was to study the effect of a dose of 150 microCi 131I on the barrier properties of the thyroid epithelium in pregnant female rats. Thirty-five female Wistar rats were divided into a control and four experimental groups (each distinguished by the time of 131I injection: group I--no less then 12 days before mating; groups II, III, and IV--on 5th, 10th, and 16th days of gestation, respectively). The thyroid glands were fixed in Bouin's fluid, embedded in paraffin, and stained immunohistochemically for thyroglobulin and fibronectin. In group IV the appearance of follicles with fibronectin-positive colloid demonstrates the penetration of blood plasma into the follicular lumen. There are more fibronectin positive follicles in group III. Regardless of the nature of the follicles' contents, numerous thyrocytes with an intensive fibronectin positive reaction begin to appear in the follicles. In group II the number of fibronectin positive follicles and thyrocytes is clearly reduced, and in group I only a few remain. In group IV there is a noticeable reduction in the quantity of colloid inside the follicles and often an absence of any thyroglobulin positive reaction. There are thyrocytes in which thyroglobulin positive granules localized in the basal zone. There is thyroglobulin positive staining in the stroma and blood vessels. In group II thyroglobulin is no longer found in the stroma. Small doses of 131I provoke a serious breakdown in the thyroid epithelium's barrier properties, although these changes are of a transient nature. The central zone of the thyroid gland reacts more actively and dynamically to exposure to radioactive iodine than the peripheral zone.