Trametenolic Acid B Reverses Multidrug Resistance in Breast Cancer Cells Through Regulating the Expression Level of P‐Glycoprotein

Yoon

Biological & Pharmaceutical Bulletin

et al. 2015

To overcome the low oral bioavailability of morin, a mixed micelle formulation with pharmaceutical excipients that facilitate solubilization and modulate P-glycoprotein (P-gp) was developed and evaluated in vitro and in vivo rats. Morin-loaded mixed micelle formulation with a morin-PluronicF127-Tween80 ratio of 1 : 10 : 0.02 (w/w/w) was prepared by a thin-film hydration method. The solubility, size distribution, drug encapsulation efficiency, and percent drug loading of the formulation were characterized. Subsequently, in vivo pharmacokinetic parameters of morin loaded in a PluronicF127 and Tween80 mixed-micelle formulation were investigated in rats. Absolute bioavailability of morin was dramatically increased by the oral administration of morin-loaded PluronicF127 and Tween80 mixed micelle from 0.4% to 11.2% without changing the systemic clearance and half-life. In Caco-2 cells, absorption permeability of morin from the novel formulation was increased 3.6-fold compared with that of morin alone. P-gp inhibition by cyclosporine A (CsA) increased absorptive permeability of morin 2.4-fold but decreased the efflux of morin by 52%, which was consistent with increased plasma concentration of morin in the pretreatment of CsA in rats. The morin formulation inhibited P-gp transport activity by 83.1% at 100 µM as morin concentration. Moreover, morin formulation increased paracellular permeability of Lucifer yellow by 1.6-1.8 fold. In conclusion, enhanced oral bioavailability of morin from morin-loaded PluronicF127 and Tween80 mixed micelle formulation can be attributed to increased intestinal permeation of morin, which was mediated at least by P-gp inhibition and enhanced paracellular route.

Section: Discussionmentioning

confidence: 98%

Enhanced Oral Bioavailability of Morin Administered in Mixed Micelle Formulation with PluronicF127 and Tween80 in Rats

Yoon

Biological & Pharmaceutical Bulletin

et al. 2015

“…Instead, TAB induced autophagic cell death in gastric cancer cells [ 40 ]. Recent evidence showed that TAB could sensitize breast cancer MDA-MB-231/Taxol cells to Taxol by increasing the intracellular accumulation of the chemo drug via abrogating the expression of major drug efflux P-gp protein [ 27 ].…”

Section: Discussionmentioning

confidence: 99%

Artemisia santolinifolia-Mediated Chemosensitization via Activation of Distinct Cell Death Modes and Suppression of STAT3/Survivin-Signaling Pathways in NSCLC

Batbold

Liu

2021

Molecules

Conventional chemotherapy remains an integral part of lung cancer therapy, regardless of its toxicity and drug resistance. Consequently, the discovery of an alternative to conventional chemotherapy is critical. Artemisia santolinifolia ethanol extract (AS) was assessed for its chemosensitizer ability when combined with the conventional anticancer drug, docetaxel (DTX), against non-small cell lung cancer (NSCLC). SRB assay was used to determine cell viability for A549 and H23 cell lines. The potential for this combination was examined by the combination index (CI). Further cell death, analyses with Annexin V/7AAD double staining, and corresponding protein expressions were analyzed. Surprisingly, AS synergistically enhanced the cytotoxic effect of DTX by inducing apoptosis in H23 cells through the caspase-dependent pathway, whereas selectively increased necrotic cell population in A549 cells, following the decline in GPX4 level and reactive oxygen species (ROS) activation with the highest rate in the combination treatment group. Furthermore, our results highlight the chemosensitization ability of AS when combined with DTX. It was closely associated with synergistic inhibition of oncogenesis signaling molecule STAT3 in both cell lines and concurrently downregulating prosurvival protein Survivin. Conclusively, AS could enhance DTX-induced cancer cells apoptosis by abrogating substantial prosurvival proteins’ expressions and triggering two distinct cell death pathways. Our data also highlight that AS might serve as an adjunctive therapeutic option along with a conventional chemotherapeutic agent in the management of NSCLC patients.

Endocrine-Related Cancer

“…2013 ). P-gp was shown to be expressed in the cell lines used (MDA-MB-231; Zhang et al . 2014 ) and HeLa ( Al-Abd et al .…”

Section: Discussionmentioning

confidence: 99%

Glucocorticoid receptor antagonism reverts docetaxel resistance in human prostate cancer

Kroon¹,

Puhr²,

Buijs³

et al. 2015

Resistance to docetaxel is a major clinical problem in advanced prostate cancer (PCa). Although glucocorticoids (GCs) are frequently used in combination with docetaxel, it is unclear to what extent GCs and their receptor, the glucocorticoid receptor (GR), contribute to the chemotherapy resistance. In this study, we aim to elucidate the role of the GR in docetaxel-resistant PCa in order to improve the current PCa therapies. GR expression was analyzed in a tissue microarray of primary PCa specimens from chemonaive and docetaxel-treated patients, and in cultured PCa cell lines with an acquired docetaxel resistance (PC3-DR, DU145-DR, and 22Rv1-DR). We found a robust overexpression of the GR in primary PCa from docetaxel-treated patients and enhanced GR levels in cultured docetaxel-resistant human PCa cells, indicating a key role of the GR in docetaxel resistance. The capability of the GR antagonists (RU-486 and cyproterone acetate) to revert docetaxel resistance was investigated and revealed significant resensitization of docetaxel-resistant PCa cells for docetaxel treatment in a dose- and time-dependent manner, in which a complete restoration of docetaxel sensitivity was achieved in both androgen receptor (AR)-negative and AR-positive cell lines. Mechanistically, we demonstrated down-regulation of Bcl-xL and Bcl-2 upon GR antagonism, thereby defining potential treatment targets. In conclusion, we describe the involvement of the GR in the acquisition of docetaxel resistance in human PCa. Therapeutic targeting of the GR effectively resensitizes docetaxel-resistant PCa cells. These findings warrant further investigation of the clinical utility of the GR antagonists in the management of patients with advanced and docetaxel-resistant PCa.