[Effect of inhibitors serine/threonine protein kinases and protein phosphatases on mitosis progression of synchronized tobacco by-2 cells].

In order to investigate the role of various serine/ threonine protein kinases and protein phosphatases in the regulation of mitosis progression in plant cells the influence of cyclin-dependent (olomoucine) and Ca2+ -calmodulin-dependent (W7) protein kinases inhibitors, as well as protein kinase C inhibitors (H7 and staurosporine) and protein phosphatases inhibitor (okadaic acid) on mitosis progression in synchronized tobacco BY-2 cells has been studied. It was found that BY-2 culture treatment with inhibitors of cyclin dependent protein kinases and protein kinase C causes prophase delay, reduces the mitotic index and displaces of mitotic peak as compare with control cells. Inhibition of Ca2+ -calmodulin dependent protein kinases enhances the cell entry into prophase and delays their exit from mitosis. Meanwhile inhibition of serine/threonine protein phosphatases insignificantly enhances of synchronized BY-2 cells entering into all phases of mitosis.

[Peculiarities of urinary bladder cancer tumor cells apoptosis response on neoadjuvant chemotherapy].

Induced apoptosis in urinary bladder cancer tumor cells of patients was studied using TUNEL reaction. It was shown that increase in induced apoptosis value had a definite correlation between corresponding features of tumor reaction as a response on Gemcitabine-Cisplatin neoadjuvant chemotherapy application. It was found that evaluation of induced apoptosis in urinary bladder cancer tumor cells using TUNEL method allows forecasting the effectiveness of chemotherapy on the cellular level in patients with this type of cancer.

[The effect of inhibitors of serinethreonine protein kinases on Arabidopsis thaliana root morphology and microtubules organization in its cells].

The effect of different types of serine/thereonine protein kinases inhibitors (cyclin-dependent, Ca2+-calmodulin-dependent and protein kinase C) on microtubules organization in cells of Arabidopsis thaliana main primary root zones were investigated in vivo. The microtubules in epidermal and cortex cells in the transition and elongation zones as well as microtubules in trichoblasts and atrichoblasts in the differentiation zone showed the greatest sensitivity to protein kinases inhibitors studied. It was established that microtubules in these cell types modified their initial transverse/oblique orientation to a chaotic or longitudinal relative to the major axis of primary root as a result of serinethereonine protein kinases inhibition. The microtubules in cells in root meristematic zone as well as in root hairs were less sensitive to influence of protein kinases inhibitors tested. Alterations of microtubules orientation in the cells in primary root zones under the influence of serinethereonine protein kinases inhibitors led to further disturbances in growth and differentiation processes. It was assumed that phosphorylation of microtubules proteins, especially tubulin, might be involved in the regulation of these processes.

[Reorganization of microtubules as a response to realization of NO (II) signal pathways in plant cell].

Effects of exogenic NO donor, sodium nitroprusside, on orientation and organization of cortical microtubules in Arabidopsis thaliana root cells that express GFP-MAP4 were studied in vivo. It was found that sodium nitroprusside treatment (10-500 microM, 24 h) caused the acceleration of primary root growth and enhanced initiation of root hairs in differentiation zone. The influence of sodium nitroprusside revealed in alterations of cortical: microtubules orientation and organization in different types of cells of A. thaliana root. The most sensitive to sodium nitroprusside exposure were microtubules in epidermal cells of elongation zone where native transverse orientation of cortical microtubules turned into random, oblique or longitudinal relatively to primary root axis. We suppose that NO as one of the intracellular secondary messengers triggers cells differentiation by cortical microtubules reorientation possibly via tubulin nitrotyrosination.

[The effect of okadaic acid on root morphology of Arabidopsis thaliana and microtubule organization in its cells].

To investigate the functional role of protein hyperphosphorylation in plant cells the general morphology of Arabidopsis thaliana primary roots and structural-functional property of cortical microtubules were studied after treatment with okadaic acid, specific inhibitor of protein phosphatases PPI and PP2A. It has been estimated that okadaic acid affects microtubule organization in a different manner depending from the type of the cells and functional zones of the primary root. It was found that the microtubules in epidermis and cortex cells of distal elongation zone which depolymerized after inhibitor treatment were the most sensitive to 0, 1, 1 and 10 nM okadaic acid concentrations. In trichoblasts, antichoblasts and cortex cells of differentiation zone treatment with okadaic acid caused the microtubules stabilization. Okadaic acid influences were particularly evident in root hair morphology, root hairs swelling and branching as a result of abnormal microtubules orientation observed. According to the data obtained, we can suggest that induction of protein hyperphosphorylation as a result of protein phosphatase inhibition plays crucial key in plant cell microtubule organization.