In silico comparisons between natural inhibitors of ABCB1/P-glycoprotein to overcome doxorubicin-resistance in the NCI/ADR-RES cell line

Empowering the Battle: Bioenhancers as Allies Against Cancer Drug Resistance

BACKGROUND

Drug resistance has been a great hindrance in the path of counteracting diseases like cancer and is driven by drugs misuse and overuse. In terms of cancer, resistance has been developed due to cellular changes, altered growth activation pathways, increased expression of efflux proteins, and changes in the local physiology of cancer (blood supply, tissue hydrodynamics, increased mutation rate/epigenetics, tumor cell heterogeneity). One of the approaches to address these challenges is the use of bioenhancers, which can overcome drug resistance, thereby improving bioavailability (BA).

CONCLUSION

Bioenhancers when combined with drugs can elicit pharmacological activity. They are generally combined with therapeutic agents at low doses, which increase the BA or therapeutic activity of active pharmaceutical ingredient (API). This review sheds light on the synthesis and classification of bio-enhancers. It also discusses different applications of bio-enhancers like piperine, ginger, quercetin, curcumin, etc. in the treatment of cancer. The review also presents some of the recent advancements in terms of nanocarriers for delivering API combined with bioenhancers.

Study Models of Drug-Drug Interactions Involving P-Glycoprotein: The Potential Benefit of P-Glycoprotein Modulation at the Kidney and Intestinal Levels

P-glycoprotein (P-gp) is a crucial membrane transporter situated on the cell's apical surface, being responsible for eliminating xenobiotics and endobiotics. P-gp modulators are compounds that can directly or indirectly affect this protein, leading to changes in its expression and function. These modulators can act as inhibitors, inducers, or activators, potentially causing drug-drug interactions (DDIs). This comprehensive review explores diverse models and techniques used to assess drug-induced P-gp modulation. We cover several approaches, including in silico, in vitro, ex vivo, and in vivo methods, with their respective strengths and limitations. Additionally, we explore the therapeutic implications of DDIs involving P-gp, with a special focus on the renal and intestinal elimination of P-gp substrates. This involves enhancing the removal of toxic substances from proximal tubular epithelial cells into the urine or increasing the transport of compounds from enterocytes into the intestinal lumen, thereby facilitating their excretion in the feces. A better understanding of these interactions, and of the distinct techniques applied for their study, will be of utmost importance for optimizing drug therapy, consequently minimizing drug-induced adverse and toxic effects.

Meta analysis of bioactive compounds, miRNA, siRNA and cell death regulators as sensitizers to doxorubicin induced chemoresistance

Cancer has presented to be the most challenging disease, contributing to one in six mortalities worldwide. The current treatment regimen involves multiple rounds of chemotherapy administration, alone or in combination. The treatment has adverse effects including cardiomyopathy, hepatotoxicity, and nephrotoxicity. In addition, the development of resistance to chemo has been attributed to cancer relapse and low patient overall survivability. Multiple drug resistance development may be through numerous factors such as up-regulation of drug transporters, drug inactivation, alteration of drug targets and drug degradation. Doxorubicin is a widely used first line chemotherapeutic drug for a myriad of cancers. It has multiple intracellular targets, DNA intercalation, adduct formation, topoisomerase inhibition, iron chelation, reactive oxygen species generation and promotes immune mediated clearance of the tumor. Agents that can sensitize the resistant cancer cells to the chemotherapeutic drug are currently the focus to improve the clinical efficiency of cancer therapy. This review summarizes the recent 10-year research on the use of natural phytochemicals, inhibitors of apoptosis and autophagy, miRNAs, siRNAs and nanoformulations being investigated for doxorubicin chemosensitization.

Selective Cytotoxicity of Piperine Over Multidrug Resistance Leukemic Cells

Multidrug resistance (MDR) is the main challenge in the treatment of chronic myeloid leukemia (CML), and P-glycoprotein (P-gp) overexpression is an important mechanism involved in this resistance process. However, some compounds can selectively affect MDR cells, inducing collateral sensitivity (CS), which may be dependent on P-gp. The aim of this study was to investigate the effect of piperine, a phytochemical from black pepper, on CS induction in CML MDR cells, and the mechanisms involved. The results indicate that piperine induced CS, being more cytotoxic to K562-derived MDR cells (Lucena-1 and FEPS) than to K562, the parental CML cell. CS was confirmed by analysis of cell metabolic activity and viability, cell morphology and apoptosis. P-gp was partially required for CS induction. To investigate a P-gp independent mechanism, we analyzed the possibility that poly (ADP-ribose) polymerase-1 (PARP-1) could be involved in piperine cytotoxic effects. It was previously shown that only MDR FEPS cells present a high level of 24 kDa fragment of PARP-1, which could protect these cells against cell death. In the present study, piperine was able to decrease the 24 kDa fragment of PARP-1 in MDR FEPS cells. We conclude that piperine targets selectively MDR cells, inducing CS, through a mechanism that might be dependent or not on P-gp.

Antiestrogenic and antiproliferative potency of secoisolariciresinol diglucoside derivatives on MCF-7 breast cancer cells

Secoisolariciresinol diglucoside (SDG) is isolated from Linum usitatissimum seeds. The antiproliferative effects of SDG (1) and its derivatives secoisolariciresinol (2) and secoisolariciresinol-4', 4″-diacetate (3) have been evaluated on MCF-7 breast cancer cells and normal breast epithelial line MCF-10A. Lignan 1 has not shown cytotoxic effects on MCF-7 cells, while derivatives 2 and 3 have inhibited cell growth with IC₅₀ values of 25 and 11 µM, respectively. Estrogen receptor alpha is a key growth driver in MCF-7 cells. Compound 1 did not affect the activity of ERα, while derivatives 2 and 3 showed significant antiestrogenic effects. Compounds 2 and 3 caused apoptosis in the MCF-7 line, determined by the cleavage of PARP. SDG derivative 3 enhanced the effect of doxorubicin. SDG derivatives can be considered as promising agents that exhibit a combined antiestrogen and proapoptotic effect in hormone-dependent breast cancer cells.

In silico and in vitro identification of secoisolariciresinol as a re-sensitizer of P-glycoprotein-dependent doxorubicin-resistance NCI/ADR-RES cancer cells

P-glycoprotein (P-gp) is one of the highly expressed cancer cell efflux transporters that cause the failure of chemotherapy. To reverse P-gp induced multidrug resistance, we employed a flaxseed-derived lignan; secoisolariciresinol (SECO) that acts as an inhibitor of breast cancer resistance protein; another efflux transporter that shares some substrate/inhibitor specificity with P-gp. Molecular dynamics (MD) simulation identified SECO as a possible P-gp inhibitor. Comparing root mean square deviation (RMSD) of P-gp bound with SECO with that bound to its standard inhibitor verapamil showed that fluctuations in RMSD were lower in P-gp bound to SECO demonstrating higher stability of the complex of P-gp with SECO. In addition, the superimposition of P-gp structures after MD simulation showed that the nucleotide-binding domains of P-gp bound to SECO undertook a more central closer position compared with that bound to verapamil. Using rhodamine efflux assay on NCI/ADR-RES cancer cells, SECO was confirmed as a P-gp inhibitor, where cells treated with 25 or 50 µM of SECO showed significantly higher fluorescence intensity compared to control. Using MTT assay, SECO alone showed dose-dependent cytotoxicity, where 25 or 50 µM of SECO caused significantly less NCI/ADR-RES cellular viability compared to control. Furthermore, when 50 µM of SECO was added to doxorubicin (DOX), an anticancer drug, SECO significantly enhanced DOX-induced cytotoxicity compared to DOX alone. The combination index calculated by CompuSyn software indicated synergism between DOX and SECO. Our results suggest SECO as a novel P-gp inhibitor that can re-sensitize cancer cells during DOX chemotherapy.

Curcumin increases the sensitivity of K562/DOX cells to doxorubicin by targeting S100 calcium-binding protein A8 and P-glycoprotein

The development of multidrug resistance (MDR) has seriously impeded the efficacy of drug treatment of chronic myeloid leukemia (CML). Recent studies have indicated that S100 calcium-binding protein A8 (S100A8) is associated with the occurrence and development of MDR. Traditional Chinese medicine may provide drugs with the potential to be used as multidrug resistance reversal agents with low toxicity and multi-target characteristics. The present study selected K562/DOX cells, a CML drug-resistant cell line, as a research model, and aimed to examine whether curcumin was able to reverse the resistance to doxorubicin (DOX), and elucidate the underlying molecular mechanisms. An MTT cytotoxicity assay indicated that curcumin at 0.5–2 µM reversed DOX resistance with a reversal index of 1.3–9.3. Western blot analysis revealed that curcumin treatment caused a downregulation of the expression of P-glycoprotein (P-gp) and S100A8 in a dose- and time-dependent manner. To study the internal association between S100A8 and P-gp, and the S100A8 role in drug resistance reversal, an RNA knockdown assay was conducted; however, S100A8 did not regulate the expression of P-gp or vice versa. After inhibiting the expression of S100A8 with specific small interfering RNA (si-S100A8), the sensitivity of K562/DOX cells to DOX was enhanced. In addition, si-S100A8 did not increase the intracellular accumulation of DOX, but increased the intracellular free calcium ion content, and the expression and activity of apoptosis-associated proteins, thereby inducing apoptosis. In conclusion, the present study suggested that inhibition of S100A8 expression increased DOX-induced apoptosis, and curcumin acted independently on S100A8 and P-gp to exert its drug resistance reversal effects

Effect of β-elemene on the kinetics of intracellular transport of d-luciferin potassium salt (ABC substrate) in doxorubicin-resistant breast cancer cells and the associated molecular mechanism

In order to explore the mechanism of the reversing multidrug resistance (MDR) phenotypes by β-elemene (β-ELE) in doxorubicin (DOX)-resistant breast cancer cells (MCF-7/DOX), both the functionality and quantity of the ABC transporters in MCF-7/DOX were studied. Bioluminescence imaging (BLI) was used to study the efflux of d-luciferin potassium salt, the substrate of ATP-binding cassette transporters (ABC transporters), in MCF-7/DOX cells treated by β-ELE. At the same time three major ABC transport proteins and genes-related MDR, P-glycoprotein (P-gp, ABCB1) and multidrug resistance-associated protein 1 (MRP, ABCC1) as well as breast cancer resistance protein (BCRP, ABCG2) were analyzed by q-PCR and Western blot. To investigate the efflux functionality of ABC transporters, MCF-7/DOX^Fluc cell line with stably-overexpressed luciferase was established. BLI was then used to real-time monitor the efflux kinetics of d-luciferin potassium salt before and after MCF-7/DOX^Fluc cells being treated with β-ELE or not. The results showed that the efflux of d-luciferin potassium salt from MCF-7/DOX^Fluc was lessened when pretreated with β-ELE, which means that β-ELE may dampen the functionality of ABC transporters, thus decrease the efflux of d-fluorescein potassium or other chemotherapies which also serve as the substrates of ABC transporters. As the effect of β-ELE on the expression of ABC transporters, the results of q-PCR and Western blot showed that gene and protein expression of ABC transporters such as P-gp, MRP, and BCRP were down-regulated after the treatment of β-ELE. To verify the efficacy of β-ELE on reversing MDR, MCF-7/DOX cells were treated with the combination of DOX and β-ELE. MTT assay showed that β-ELE increased the inhibitory effect of DOX on the proliferation of MCF-7/DOX, and the IC₅₀ of the combination group was much lower than that of the single DOX or β-ELE treatment. In all, β-ELE may reverse MDR through the substrates of ABC transporters by two ways, to lessen the ABC protein efflux by weakening their functionality, or to reduce the quantity of ABC gene and protein expression.