Organic anion transporters and PI3K–AKT–mTOR pathway mediate the synergistic anticancer effect of pemetrexed and rhein

Abstract

The aim of this study was to explore whether rhein could enhance the effects of pemetrexed (PTX) on the therapy of non-small-cell lung cancer (NSCLC) and to clarify the associated molecular mechanism. Our study shows that rhein in combination with PTX could obviously increase the systemic exposure of PTX in rats, which would be mediated by the inhibition of organic anion transporters (OATs). Furthermore, the toxicity of PTX was significantly raised by rhein in A549 cells in a concentration-dependent manner.Concomitant administration of rhein and PTX-induced cell apoptosis compared with PTX alone in flow cytometry assays, which was further validated by the protein expressions of the apoptotic markers B-cell lymphoma-2/Bcl-2-associated x (Bcl-2/Bax) and Cleaved-Caspase3 (Cl-Caspase3). Meanwhile, the results of monodansylcadaverine (MDC) dyeing experiments showed that PTX-induced autophagy could be enhanced by combination therapy with rhein in A549 cells. Western blot analysis indicated that the synergistic effect of rhein on PTX-mediated autophagy may be interrelated to PI3K-AKT-mTOR pathway inhibition and to the enhancement of p-AMPK and light chain 3-Ⅱ (LC3-Ⅱ) protein levels.From these findings, it could be surmised that rhein enhanced the antitumor activity of PTX through influencing autophagy and apoptosis by modulating the PI3K-AKT-mTOR pathway and Bcl-2 family of proteins in A549 cells. Our findings demonstrated that the potential application of rhein as a candidate drug in combination with PTX is promising for treatment of the human lung cancer.

Therapeutic Emergence of Rhein as a Potential Anticancer Drug: A Review of Its Molecular Targets and Anticancer Properties

“…In vitro Caco-2 p-ERK1/2↑ (at higher concentrations of rhein) [150] In vitro HT29, HCT116, Colo205, SW620 HIF-1α↓, PD-L1↓, VEGF↓, COX-2↓, galectin-1↓ [98] In vitro HCT116, SW620 p-STAT3↓ [151] Glioma In vitro F98 ERK1/2↓ [152] In vitro T98G, U87, U251 Ac-K100↑, NDRG1↑ [153] Leukemia In vivo EU-1 injected SCID mice MDM2↓, p53↑ [154] In vitro HL-60 Cleaved caspase↑, cleaved PARP↑, cleaved Bid↑, ∆Ψm↓ [145] In vitro NB4 p-ERK↑, Caspase-3↑ [155] Liver cancer In vitro and in vivo HepG2, HepG2 injected BALB/c-nu mice β-catenin↓, S phase arrest↑ [111] In vitro HepG2 CD95↑, p53↑, p21/WAF↑, mCD95L↑, sCD95L↑ [96] In vitro BEL-7402 c-Myc↓, Caspase-3↑, S phase arrest↑ [54] In vitro SMMC-7721, SMMC-7721/DOX ATP synthesis↓, inner ∆Ψm↓ [156] In vitro HepG2, Huh7 ROS↑, p-c-Jun↑, Caspase-3↑ [55] Lung cancer In vitro and in vivo PC-9, H460, A549, H460 xenograft mice STAT3↓, Bax↑, Bcl-2↓, G2/M phase arrest↑ [157] In vitro A549 p-PI3K↓, Akt↓, mTOR↓, Bcl-2↓ [158] In vitro A549 G0/G1 phase arrest↑, GADD153↑, GRP78↑, Cyt c↑,…”

“…Many reports have also highlighted the potential therapeutic effects of rhein against lung cancer. Bu et al (2020) demonstrated that rhein induced apoptosis in A549 cells by modulating the expression of p-AMPK, mTOR, and Bcl-2 proteins [158]. The reduced Bcl-2 expression, Cyt c efflux, the rapid loss of ∆Ψm and enhanced caspase-3 activity led to apoptosis in these cells.…”

Quinones as preventive agents in Alzheimer’s diseases: focus on NLRP3 inflammasomes

“…Rhein is found in R. palmatum L., Aloe barbadensis Miller, Cassia angustifolia Vahl and P. multiflorum Thunb, [ 77 ] which has anti‐inflammatory, [ 78 ] anti‐cancer, [ 79 ] antioxidant [ 80 ] and neuroprotection activities. [ 81 ] Rhein could improve recognition memory impairment, alleviate neuroinflammation and BDNF deficits in the perirhinal cortex on high‐fat‐diet‐induced animal model.…”

Exploring the Pharmacological Mechanism of Cassiae Semen a Cting on Cataracts Based on a Network Pharmacology Approach

“…It was reported to attenuate both innate and adaptive immune responses, and inhibit in ammatory cell recruitment and oxidative stress as well [15,32]. Rhein a major component of many medicinal herbs with various properties, including anti-in ammatory, antioxidant and anticancer activities [33][34][35]. Oxidative stress has been observed in the onset and progression of cataractogenesis [36,37], and antioxidants and free radical scavengers have been suggested as potential drugs for the management of cataracts.…”