Deep insights into the response of human cervical carcinoma cells to a new cyano enone-bearing triterpenoid soloxolone methyl: a transcriptome analysis

Abstract

Semisynthetic triterpenoids, bearing cyano enone functionality in ring A, are considered now as novel promising anti-tumor agents. However, despite the large-scale studies, their effects on cervical carcinoma cells and, moreover, mechanisms underlying cell death activation by such compounds in this cell type have not been fully elucidated. In this work, we attempted to reconstitute the key pathways and master regulators involved in the response of human cervical carcinoma KB-3-1 cells to the novel glycyrrhetinic acid derivative soloxolone methyl (SM) by a transcriptomic approach. Functional annotation of differentially expressed genes, analysis of their cis - regulatory sequences and protein-protein interaction network clearly indicated that stress of endoplasmic reticulum (ER) is the central event triggered by SM in the cells. A range of key ER stress sensors and transcription factor AP-1 were identified as upstream transcriptional regulators, controlling the response of the cells to SM. Additionally, by using Gene Expression Omnibus data, we showed the ability of SM to modulate the expression of key genes involved in regulation of the high proliferative rate of cervical carcinoma cells. Further Connectivity Map analysis revealed similarity of SM's effects with known ER stress inducers thapsigargin and geldanamycin, targeting SERCA and Grp94, respectively. According to the molecular docking study, SM could snugly fit into the active sites of these proteins in the positions very close to that of both inhibitors. Taken together, our findings provide a basis for the better understanding of the intracellular processes in tumor cells switched on in response to cyano enone-bearing triterpenoids.

Dual Effect of Soloxolone Methyl on LPS-Induced Inflammation In Vitro and In Vivo

“…The analysis showed that SM significantly induced c-Jun expression in macrophages in comparison to LPS-challenged control cells ( Figure 6 G), demonstrating the ability of SM to positively regulate AP-1 in RAW264.7 macrophages. These results are consistent with published data on the up-regulation of c-Jun and c-Fos detected in KB-3-1 cells and HUVEC treated with SM and CDDO-Im, respectively [ 60 , 133 ]. Thus, our findings demonstrate that the stimulatory effect of SM on LPS-induced pro-inflammatory cytokine production in macrophages is regulated by the c-Jun/TLR4 signaling axis.…”

“…Recently, we showed that SM treatment significantly upregulates the expression of HO-1 in the human cervical carcinoma KB-3-1 cells [ 60 ]. Here, we studied whether SM could stimulate the production of HO-1 in RAW 264.7 macrophages.…”

“…Our findings clearly demonstrate that SM displayed marked antioxidant potential, as the treatment of macrophages by SM significantly decreased the generation of ROS in both unstimulated and LPS-stimulated cells ( Figure 3 C) and the production of NO by inflamed macrophages ( Figure 3 F). In order to more accurately interpret the obtained results, we investigated the effects of a semisynthetic triterpenoid on the expression of heme oxigenase-1 (HO-1), which is a key antioxidant enzyme that, according to our recent report, was significantly susceptible to SM in another cellular model [ 60 ], and inducible nitric oxide synthase (iNOS). We showed that the treatment of LPS-challenged RAW264.7 cells with SM caused a significant up-regulation of HO-1 ( Figure 3 A,B) and reduced iNOS expression ( Figure 3 E), which is consistent with the revealed ability of SM to inhibit the release of ROS and NO by macrophages.…”

“…However, the question remained as to which signaling pathway can mediate both the observed up-regulation of TLR4 in SM-treated macrophages ( Figure 6 H) and signal transduction from activated TLR4 to the genes encoding pro-inflammatory cytokines, taking into account that NF-κB signaling was blocked by SM ( Figure 6 C–F). In our previous report, we showed that AP-1 is one of the key master regulators controlling the response of KB-3-1 cervical carcinoma cells to SM [ 60 ]. Given this fact, the involvement of AP-1 in the regulation of TLR4 expression and pro-inflammatory cytokines [ 131 ] and the regulatory role of c-Jun, a key component of AP-1, in modulating the effects of a structural analogue of SM (RTA408) on the IL-1β-induced inflammatory response in rat astrocytes [ 132 ], we analyzed the effect of SM on the expression of c-Jun in LPS-treated RAW264.7 cells.…”

Cyano Enone-Bearing Triterpenoid Soloxolone Methyl Inhibits Epithelial-Mesenchymal Transition of Human Lung Adenocarcinoma Cells In Vitro and Metastasis of Murine Melanoma In Vivo

“…In this work, we concentrated on the question whether cyano enone-containing semisynthetic triterpenoids or steroids can modulate EMT of human lung adenocarcinoma A549 cells, stimulated by TGF-β. Performed screening of chemical derivatives of 18βH-glycyrrhetinic (SM, TM) and deoxycholic (pi-153, pi-156) acids, marked bioactivity of which was identified previously [35][36][37]41], for inhibition of motility of A549 and B16 cells revealed SM as a hit compound, significantly suppressing in non-toxic concentration the migration capacity of both cell lines (Figure 3). The remaining compounds either showed a lower level of bioactivity compared to SM (pi-153) or were unable to affect motility of tumor cells at all (TM, pi-156).…”