Insights into the control of taxane metabolism: Molecular, cellular, and metabolic changes induced by elicitation in Taxus baccata cell suspensions

Abstract

More knowledge is needed about the molecular/cellular control of paclitaxel (PTX) production in Taxus spp. cell cultures. In this study, the yield of this anticancer agent in Taxus baccata cell suspensions was improved 11-fold after elicitation with coronatine (COR) compared to the untreated cells, and 18-fold when co-supplemented with methyl-β-cyclodextrins (β-CDs). In the dual treatment, the release of taxanes from the producer cells was greatly enhanced, with 81.6% of the total taxane content being found in the medium at the end of the experiment. The experimental conditions that caused the highest PTX production also induced its maximum excretion, and increased the expression of taxane biosynthetic genes, especially the flux-limiting BAPT and DBTNBT. The application of COR, which activates PTX biosynthesis, together with β - CDs, which form inclusion complexes with PTX and related taxanes, is evidently an efficient strategy for enhancing PTX production and release to the culture medium. Due to the recently described role of lipid droplets (LDs) in the trafficking and accumulation of hydrophobic taxanes in Taxus spp. cell cultures, the structure, number and taxane storage capacity of these organelles was also studied. In elicited cultures, the number of LDs increased and they mainly accumulated taxanes with a side chain, especially PTX. Thus, PTX constituted up to 50-70% of the total taxanes found in LDs throughout the experiment in the COR + β - CD-treated cultures. These results confirm that LDs can store taxanes and distribute them inside and outside cells.

Impact of Elicitation on Plant Antioxidants Production in Taxus Cell Cultures

“…Cell suspension cultures were established from a stable friable callus line of T. baccata , as previously described in [ 17 ]. After surface sterilization, a callus line was obtained by placing the explants in contact with the callus induction medium, which consisted of Gamborg’s B5 medium (B5) [ 18 ] supplemented with 2x B5 vitamins, 3% ( w/v ) sucrose, and the following growth regulators: 4 mg/L 2,4-dichlorophenoxyacetic acid, 1 mg/L kinetin, and 0.5 mg/L gibberellic acid.…”

“…Calli were then kept at 25 °C in darkness and subcultured every two weeks under the same conditions. To establish T. baccata cell suspensions, a two-stage system was used as described in [ 17 ]. Briefly, after 14 days of culturing the cells in liquid growth medium, 3 g of cells was transferred to 10 mL of taxane production medium in a 175 mL flask capped with a MagentaTM B-cap (Sigma Aldrich, St Louis, MO, USA).…”

Genetic approaches in improving biotechnological production of taxanes: An update

“…Another important compound produced by means of these biotechnological tools is paclitaxel (PXT), which was approved by the Food and Drug Administration (FDA) for the treatment of refractory metastatic ovarian cancer in 1992, and metastatic breast cancer (refractory or insensitive to anthracyclines) in 1994. The highly positive results obtained with PTX have extended its use to non-small cell lung, prostate, stomach, cervical, esophageal, testicular, and pancreatic cancers, as well as AIDS-related Kaposi’s sarcoma and leukopenia ( Perez-Matas et al., 2022 ). Additionally, PTX is now under study for the treatment of neurodegenerative disorders such as Alzheimer’s or Parkinson’s disease ( Zhang et al., 2005 ) and other health conditions related with the stabilization of microtubule-associated proteins such as psoriasis ( Ehrlich et al., 2004 ).…”

“…Due to its effectivity, PTX is perhaps the most important antitumor agent in history. In 2021, the global PTX market was valued at US$ 4.51 billion and is expected to reach over US$ 11.16 billion by 2030 ( Perez-Matas et al., 2022 ). More than 20 companies in several countries are involved in the development and commercialization of new pharmaceutical forms of PTX, most notably in the US, which accounts for almost 40% of the global oncology market ( Sofias et al., 2017 ).…”

“…cell cultures is the current method of choice because cell suspensions can be grown under controlled and cost-effective conditions. For instance, Plant Cell Fermentation (PCF ® ) technology has been implemented by Phyton Biotech, the world’s largest nowadays supplier of PTX ( Perez-Matas et al., 2022 ). Despite this, the PTX yields of biotechnological production platforms remain low.…”