21:I[432972,["/_next/static/chunks/bb923814e1f4d2e9.js","/_next/static/chunks/dd3ee9f5b7716ca6.js","/_next/static/chunks/4204a0ae82542ca8.js","/_next/static/chunks/1270dead247da766.js","/_next/static/chunks/6e1aa89a642f40be.js","/_next/static/chunks/b3eb9795ffa7b0d3.js","/_next/static/chunks/8ffd0b71567920d8.js","/_next/static/chunks/67ea6dfd21f16c5f.js","/_next/static/chunks/24eb4379f68013fd.js","/_next/static/chunks/b8cd775ffdf935bd.js","/_next/static/chunks/983103cd9eb7b428.js","/_next/static/chunks/263f2cdcb9aa2341.js","/_next/static/chunks/294b9525248c8e5f.js"],"default"] 22:T490,The pineal hormone melatonin (MLT) has been recognised as a substance capable of alleviating in vivo nephro-, cardio- and myelotoxicity of doxorubicin (DOX) and of other anthracyclines in animal models. However, few data are available on the effects of MLT on cytotoxicity of antineoplastic drugs toward tumor cells in vitro. The present study aimed at the evaluation of effects of MLT and of DOX on selected cell lines. The experiments were conducted on human keratinocytes (primary culture), non-small cell lung cancer (A-549) and laryngeal cancer cell lines (HEp-2). In keratinocytes and in A-549 cells, MLT used at pharmacological concentrations (0.1 and 1.0 mM) was observed to intensify apoptotic lesions. MLT exerted no clear-cut effects on the HEp-2 cell line. In contrast, DOX at concentrations of 0.1 and 1.0 microg/ml intensified apoptosis and augmented the frequency of necrotic lesions in cell nuclei in all the examined cell lines. MLT intensified cytotoxicity of DOX in all cell lines, significantly decreasing cell numbers and promoting apoptosis. The effect was MLT concentration-dependent. MLT decreased the proportion of cells with necrotic lesions.23:T435,Langerhans cell histiocytoses (LCH) represent rare diseases of unclear etiology and pathogenesis. Most of the cases include children, 1 to 15 years of age, and various organs are involved (bones, skin, liver, lymph nodes, bone marrow and other). The diagnosis of LCH used to be established by biopsy of the inflamed tissue and demonstration of expression of markers specific for Langerhans cells: CD1a and langerin. The diagnosis can be ultimately confirmed by demonstration of Birbeck's granules in the electron microscopy. The present study was aimed at immunocytochemical demonstration, in the examined LCH material (skin, bones, lymph nodes), of the specific antigen expression and at comparing it with the presence of Birbeck's granules. In the examined 11 cases co-expression of CD1a with langerin and with the presence of Birbeck's granules was noted. Also in all examined biopsies the expression of S-100 protein on inflammatory cells was found. The results corroborate the usefulness of immunocytochemical studies on CD 1 a and langerin expression in diagnosis of LCH.24:T532,Multi-drug resistance (MDR) is the main cause of low effectiveness of cancer chemotherapy. P-glycoprotein (P-gp) is one of the main factors determining MDR. Some studies indicate the potential role of melatonin (MLT) in MDR. In this study, we examined the effect of MLT on colon cancer cell's resistance to doxorubicin (DOX). Using the sulforhodamine B (SRB), method the effect of tested substances on the survival of LoVo (colon cancer cells sensitive to DOX) and LoVo_DX (colon cancer cells resistant to DOX) was rated. Using immunocytochemistry (ICC), the expression of P-gp in the LoVo and LoVo_DX was determined. With the real-time PCR (RT-PCR) technique, the ABCB1 expression in LoVo_DX was evaluated. Based on the results, it was found that MLT in some concentrations intensified the cytotoxicity effect of DOX in the LoVo_DX cells. In the ICC studies, it was demonstrated that certain concentrations of MLT and DOX cause an increase in the percentage of cells expressing P-gp, which correlates positively with ABCB1 expression (RT-PCR). The mechanism of overcoming resistance by MLT is probably not only associated with the expression of P-gp. It seems appropriate to carry

#	Concept	H-Index	Publications	Citations
1	Medicine	2	2	87
2	Immunology	2	2	87
3	Cell Biology	1	1	41
4	Cellular Physiology	1	1	41
5	Pathology	1	1	41

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