Effects of taxol treatment on the microtubular system and mitochondria of Tetrahymena

Abstract

Complex investigation was done using immunocytochemical confocal microscopy, electron microscopy and flow cytometry on the effect of taxol to the microtubular arrangement and dynamics. The most interesting phenomenon was the rapid disappearance of transversal microtubule bands, while longitudinal microtubule bands remained and were submitted to the known effects of taxol. There was a broad variation in mitochondrial effect, some of them remained normal, while others swollen, desintegrated and their tubules disoriented. Treatment with 50 nM taxol significantly reduced the binding of anti alpha-tubulin antibody and a lesser degree anti-acetylated tubulin antibody. The difference between the transversal and longitudinal microtubules is emphasized by the results and the paper discusses the possibilities of indirect effects of taxol to the transversal microtubules (tubulin-GTP interaction, faster turnover, mitochondrial interaction). Polyglutamylation of tubulin has not a role in this difference.

Assessment of genetic and epigenetic variation during long-term Taxus cell culture

“…It is well known that secondary metabolites play a major role in the adaptation of plants to the changing environment and in overcoming stress constraints, and higher concentrations of secondary metabolites might result in a more resistant plant, but the production of secondary metabolites is thought to be costly and reduces plant growth and reproduction (Siemens et al 2002). Paclitaxel is a cytotoxic substance that inhibits cell proliferation by binding to the microtubule surface, specifically to the subunits of the tubulin heterodimers, thus promoting tubulin depolymerization (Kovács et al 2007). Kim et al (2004) found that cell cultures of high paclitaxel producing Taxus cells demonstrated growth inhibition upon subculture, whereas non-paclitaxel producing ones demonstrated little growth inhibition; therefore, the group speculated that growth inhibition was primarily due to paclitaxel or taxane accumulation.…”

Autophagy inhibition re-sensitizes pulse stimulation-selected paclitaxel-resistant triple negative breast cancer cells to chemotherapy-induced apoptosis

“…Therefore, chemotherapy is still the mainstay of systemic treatment for TNBC [6]. Paclitaxel is a mitotic inhibitor-based chemotherapeutic drug [8, 9], due to its high efficiency, and is widely used to treat TNBC. Unfortunately, drug resistance is still a major hurdle in the use of paclitaxel and limits its effectiveness.…”

Ethnomedical Properties of Taxus Wallichiana Zucc. (Himalayan Yew)

“…It received wide attention recently because its leaves and bark were found to be the prime source of taxol, a potent anticancer drug which has a unique property of preventing the growth of cancerous cells and is used in the treatment of breast and ovarian cancers. [4] Taxol was first isolated from the bark of Taxus brevifolia ,[5] and since then, taxol and related bioactive taxoids have been reported from various other species of the genus Taxus. [67] Excellent clinical results with taxol in the treatment of various cancers, particularly in refractory ovarian and breast cancers, have led to substantial demand for this drug.…”