Curcuma zedoaria petroleum ether extract reverses the resistance of triple-negative breast cancer to docetaxel via pregnane X receptor

Abstract

Background: Triple-negative breast cancer (TNBC) is characterized by its aggressiveness and poor prognosis. Docetaxel is the common chemotherapeutic drug used in the treatment of TNBC. However, resistance to docetaxel has limited the effectiveness of TNBC treatment. Petroleum ether extracts of Curcuma zedoaria (PECZ) can inhibit the proliferation of MDA-MB-231 cells. However, the effect of PECZ on docetaxel resistance is not clear. Methods: A docetaxel-resistant MDA-MB-231 (MDA-MB-231/docetaxel) cell line was established, and Cell Counting Kit-8 (CCK-8), quantitative real-time PCR (qRT-PCR), and western blotting assays were used to evaluate the effect of docetaxel resistance in MDA-MB-231 cells. Next, CCK-8 was also performed to detect the effect of docetaxel or the combination treatment of docetaxel and PECZ on the proliferation of MDA-MB-231/docetaxel cells. Thereafter, MDA-MB-231/docetaxel cells were subcutaneously injected into nude mice to induce a TNBC xenograft model, and the mice were divided into a model group, docetaxel group, PECZ group, and combination of docetaxel and PECZ group. Subsequently, hematoxylin and eosin (HE) staining, immunohistochemical, qRT-PCR, and western blotting were used to estimate the effect of pre-treatment with PECZ on docetaxel tolerance reversal. Results: PECZ significantly inhibited the expression of pregnane X receptor (PXR), multidrug resistance 1 (MDR1), breast cancer resistance protein (BCRP), and cytochrome P-450 (CYP3A4) in MDA-MB-231/ docetaxel cells. Only higher concentrations of docetaxel could inhibit the viability of MDA-MB-231/ docetaxel cells. When pre-treated with PECZ, lower concentrations of docetaxel could significantly inhibit cell viability. Meanwhile, combination treatment also reduced the tumor volume, ameliorated the pathological change of tumor tissues, and down-regulated the expressions of PXR, MDR1, BCRP, and CYP3A4 (according to HE staining, immunohistochemical, qRT-PCR and western blotting results in vivo).Conclusions: Our research showed that PECZ reversed docetaxel resistance in TNBC by PXR both in vitro and in vivo, which provides the basis for further investigations into the potential therapeutic impact of docetaxel resistance in TNBC.

Advances in drug resistance of triple negative breast cancer caused by pregnane X receptor

“…Alexanian et al [ 34 ] reported the lower expressions of CYP4A11 and CYP4A22 in normal breast tissues than those in TNBC tissues. Overexpression of CYP3A4 can promote the metabolism of docetaxel in triple negative breast cancer stem cells and further induce reduced accumulation of chemotherapy drugs in cancer cells, leading to cell drug resistance[ 22 ]. Two major metabolic enzymes of paclitaxel (CYP2C8, CYP3A4) and other genes involved in taxane heterogenic metabolism ( e.g.…”

“…, CYP1B1) are associated with drug resistance in TNBC[ 35 ]. Numerous experiments have shown that CYP enzymes are significantly upregulated in TNBC patients [ 22 , 29 , 35 ]. Therefore, the association between CYP enzymes and tumor resistance in TNBC has attracted increasing attention.…”

“…It has been reported that activated PXR can transcriptically up-regulate the expression of CYP450 family members such as CYP3A4, CYP3A23, CYP2B6, CYP2B9, CYP2C55, CYP2C9 and CYP1A[ 36 , 37 ]. In experimental studies related to TNBC drug resistance, it has been confirmed that PXR can regulate the expression of CYP3A4, resulting in increased drug metabolism in TNBC, which is obviously related to TNBC chemotherapy resistance[ 22 ].…”

“…The MRP gene is a membrane transporter encoded by the ABCC gene, whereas BCRP is a membrane transporter encoded by the ABCG gene. In breast cancer related studies, ABCC1, ABCC3, ABCB1 and ABCG2 are associated with drug resistance [ 22 , 30 , 33 ]. Compared with other breast cancer subtypes, tmultidrug resistance protein-1 (ABCC1/MRP1), MDR protein-8 (ABCC11/MRP8) and BCRP (ABCG2/BCRP) is significantly overexpressed in TNBC[ 58 , 59 ], which is closely related to chemotherapy resistance[ 60 ].…”

“…PXR can affect the expression of drug resistance-related genes, thereby enhancing the metabolism and clearance function of chemotherapy drugs in cancer cells[ 20 ], and then plays an important role in breast cancer[ 21 ]. Studies have shown that the expression of PXR increased in docetaxel-resistant TNBC cells and tumor xenograft mice[ 22 ]. This article reviews the role of PXR in the drug resistance mechanism of TNBC.…”