摘要:

α-Fetoprotein (AFP), depending on the surrounding conditions, exerts different functions by different mechanisms. (1) A regulatory effect on the concentration of the unbound form of its various ligands (e.g. fatty acids, estrogens, phytosteroids). Thus, numerous studies have demonstrated that fatty acids, particularly the polyunsaturated fatty acids, modulate positively or negatively many steps of the action of various steroids and many enzymes involved in the transduction of membrane-triggered signals. (2) Different conformations (holoforms) of AFP, depending on the nature and concentration of the ligand(s) bound, might influence the binding of the protein to specific receptor(s) and as a consequence its biological properties (internalization, action on the membrane signal transduction pathway). (3) Regardless of the mechanisms, proposed in points 1 and 2, the protein can exert effects associated with other signals such as growth factors. The nature of the associated growth factor(s) and AFP ligand(s) can orient cells towards multiplication or differentiation

ISSN:1010-4283    

DOI:10.1159/000217876

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Ras p21 and epidermal growth factor receptor (EGFR) have commonly been implicated in a variety of malignancies. The present study immunohistochemically analysed the relationship between the expression of ras p21 and EGFR in normal, premalignant and malignant lesions of the oral mucosa. Except for normal mucosa, all other lesions showed a more or less similar expression pattern of both ras p21 and EGFR. It was also observed that the expression of both proteins was mostly confined to the basal or basaloid cells of the leucoplakia and carcinoma lesions, respectively. Normal keratinizing type mucosa showed expression of ras p21 and EGFR in the basal and lower spinal cells. However, in non-keratinizing mucosa the expression of ras p21 was totally negative while EGFR was restricted to the basal cells. Statistical analysis revealed a good correlation between the expression of ras p21 and EGFR with the various histological stages of tumour progression. The presence of these proteins in immature dividing cells of premalignant and malignant lesions thus emphasizes their relationship with cell proliferation.

ISSN:1010-4283    

DOI:10.1159/000217877

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Cell membrane potentials were measured in breast tissue and in breast epithelial cells to explore the relation between cell membrane potentials, oncogenesis and electrical potentials previously measured on the surface of the breast. The mean membrane potential in breast biopsy tissue from 9 women with infiltrating ductal carcinoma was significantly depolarized, compared with values measured in tissue from 8 women with benign breast disease. Depolarization was also observed in transformed breast epithelial cells, compared with normal breast cells; the transformed cells were particularly sensitive to the action of K+ channel blockers. The results were consistent with previous observations of electropositivity of skin sites over malignant tumors of the breast.

ISSN:1010-4283    

DOI:10.1159/000217878

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

In order to better understand the interaction between activated lymphocytes and breast carcinoma cells, we studied the degree of infiltration, the membrane contacts established and their cytostatic and cytolytic effects in MCF-7 nodules maintained in three-dimensional culture. A comparison was made with nodules of a nonmalignant, immortalized mastosis cell line. Histological, immunohistochemical and electron microscopical observations were performed as well as DNA synthesis measurements in the two components of the coculture. The lymphokine-activated killer (LAK) cells adhered more frequently to the carcinoma nodules than to the mastosis nodules. They actively penetrated into both of them. The penetration remained peripheral, and only a few cells migrated more deeply. The LAK cells established close cell-to-cell contacts with the two types of nodules, and intercellular gaps were formed: damaged cells could be seen near the activated killer cells. In MCF-7 nodules, a 5-fold inhibition of proliferation occurred, and extensive necrotic zones developed; this was accompanied by a general tendency for glandular redifferen-tiation. In mastosis nodules, necrosis also developed but no cell differentiation occurred and proliferation was less inhibited (2 times). Interleukin-2 alone enhanced DNA synthesis in mastosis nodules but had no effect on MCF-7 nodules, and no extending necrosis could be seen in both types of nodules. The cytolytic effects of LAK cells combined with their redifferen-tiating effect in MCF-7 breast carcinoma nodules may be a useful indication for further breast cancer therapy research.

ISSN:1010-4283    

DOI:10.1159/000217879

出版商:S. Karger AG    

年代:1994

数据来源: Karger

ISSN:1010-4283    

DOI:10.1159/000217880

出版商:S. Karger AG    

年代:1994

数据来源: Karger

ISSN:1010-4283    

DOI:10.1159/000217881

出版商:S. Karger AG    

年代:1994

数据来源: Karger