ABCB1 overexpression

These potent MDR1 inhibitors were found to enhance chemosensitivity to doxorubicin in MDR1-overexpressing cells...Furthermore, the total number of methoxy groups in the flavonol backbone was found to be a significant factor in determining the potency of MDR1 inhibition. These observations provide fundamental insights into the structure-activity relationship between flavonol derivatives and MDR1 inhibition, potentially aiding in overcoming drug resistance in cancer.

In the tumor-bearing mouse model, mobocertinib boosted the antitumor effect of paclitaxel and topotecan, resulting in tumor regression. In summary, our study uncovers a novel potential for repurposing mobocertinib as a dual inhibitor of ABCB1 and ABCG2, and suggests the combination of mobocertinib with substrate drugs as a strategy to counteract MDR.

In vivo studies have shown that gilteritinib improves the antitumor efficacy of paclitaxel in nude mice without obvious toxic effects. In conclusion, our preclinical investigations show that gilteritinib has the potential to successfully overcome ABCB1-mediated MDR in a clinical environment when combined with substrate medicines.

Taken together, our results confirm that HHT is a substrate for MDR1. It opens the door to a new opportunity to clinically evaluate HHT and its derivatives for the treatment of AML and other cancers.

In parallel, this dual ABCB1/CYP1B1 inhibitory effect drives compound A10 exhibiting prominent drug resistance reversal activity to doxorubicin (IC50 = 4.7 μM, RF = 13.7) in ABCB1/CYP1B1-overexpressing DOX-SW620/AD300-1B1 resistant cells, which is more potent than that of the CYP1B1 inhibitor ANF. Furthermore, although compound A2 possessed moderate ABCB1/CYP1B1 inhibitory activity, it showed considerable antiproliferative activity towards drug-resistant SW620/AD300 and MKN45-DDP-R cells, which may be partly related to the increase of PUMA expression to promote the apoptosis of the drug-resistant MKN45-DDP-R cells as confirmed by proteomics and western blot assay. These results indicated that the tetrahydroisoquinoline-benzo[h]chromen-4-one conjugates may provide a fundamental scaffold reference for further discovery of MDR reversal agents.

In summary, our study demonstrates an additional pharmacological capability of epertinib against the activity of ABCB1 and ABCG2. These findings suggest that incorporating epertinib into combination therapy could be advantageous for a specific patient subset with tumors exhibiting high levels of ABCB1 or ABCG2, warranting further exploration.

Altered expression of ABCB1 and ABCG2 may not be a useful prognostic marker for survival or response to chemotherapy in GBC. Presently, histo-pathological characteristics and associated gallstones are the important predictors for survival and recurrence in GBC.

Novel MDR modulators could be identified with favorable methoxy and ester group functions. Their use in both ABCB1 non-expressing and overexpressing cells proves a selective toxicity-increasing effect of the applied anticancer agent in the ABCB1 overexpressing cells, whereas the toxicity effect of the anticancer drug was almost unchanged in the non-expressing cells. These results qualify our novel compounds as perspective anticancer drugs compared to MDR modulators with nonselective toxicity properties.

GBM 101.8 is a reliable model for further investigation due to its similarity to high-grade human GBMs, while GBM 11-9-2 and GBM 14-4-5 correspond to Grade 2-3 gliomas.

Stachybotrysin B (8) can reverse multidrug resistance (MDR) in ABCB1-overexpression cells (KBv200, Hela/VCR) at the non-cytotoxic concentration. Doxorubicin accumulation assay and molecular-docking analysis reveal that the mechanism of its reversal MDR effect may be related to the increase in the intracellular concentration of substrate anticancer drugs.

these findings suggest that combining siRNA, doxorubicin, and vinorelbine holds promise as a therapeutic strategy to overcome ABCB1-mediated multidrug resistance in breast cancer. Further investigations and clinical trials are warranted to evaluate its clinical efficacy rigorously.

The areas of drug resistance covered in this article involve: 1) Modulation of ABC transporter function, 2) Targeting lysosomal ABCB1 overexpression, 3) Circumvention of ABC transporter-mediated drug efflux by alternative routes of drug uptake, 4) Selective activity against MDR cancer models (collateral sensitivity), 5) Targeting GSH-detoxifying systems, 6) Overcoming apoptosis resistance by inducing necrosis and paraptosis, 7) Reactivation of mutated p53, 8) Restoration of sensitivity to DNA-damaging anticancer therapy, and 9) Overcoming drug resistance through modulation of the immune system. Through this approach, we would like to draw attention to Schiff bases and their metal complexes representing highly interesting anticancer drug candidates with the ability to overcome MDR.

AU-24118 demonstrated tumor regression in a model of castration-resistant prostate cancer (CRPC) which was further enhanced with combination enzalutamide treatment, a standard of care androgen receptor (AR) antagonist used in CRPC patients. The ABCB1 inhibitor, zosuquidar, reversed resistance to all three PROTAC degraders tested. Combined, these findings position mSWI/SNF degraders for clinical translation for patients with enhancer-driven cancers and define strategies to overcome resistance mechanisms that may arise.

The solution is to use a proper inhibitor of P-gp efflux activity to ensure the retention of the tracer inside the cells. The present study showed that Zosuquidar and Tariquidar (P-gp inhibitors) are suitable for monitoring intracellular calcium, either by flow cytometry or confocal microscopy, in cells overexpressing P-gp.

Valproate can affect drug resistance in gastric cancer via a unique mechanism independent of MDR1 expression.

Co-treatment with GDC-0152 restored the sensitivity to the known ABCB1 substrates, including paclitaxel, vincristine, and YM155 in ABCB1-expressing multidrug-resistant cancer cells, and it also restored the sensitivity to tamoxifen in BIRC5-overexpressing tamoxifen-resistant breast cancer cells in vitro...In conclusion, GDC-0152 has the potential for use in the management of cancer patients with ABCB1 and BIRC5-related drug resistance. The findings of our study provide essential information to physicians for designing a more patient-specific GDC-0152 clinical trial program in the future.

The results of our study demonstrated the essential role of NAT10-mediated ac4c-modification in breast cancer progression and provide a novel strategy for overcoming chemoresistance challenges.

Maraviroc treatment did not affect OC cell viability, but strongly potentiated the antiproliferative activity, apoptosis induction, cell cycle blockage, DNA damage, and ROS formation by trabectedin. In A2780cis cisplatin-resistant cells, the cross-resistance to trabectedin was overcame by the combination with maraviroc. Maraviroc enhanced trabectedin cytotoxicity in OC 3Dimensional spheroids and THP-1-monocytes. Both maraviroc and trabectedin interact with drug efflux pump MDR1/P-gp, overexpressed in recurrent OC patients. Maraviroc increased trabectedin intracellular accumulation and the MDR1-inhibitor verapamil, like maraviroc, increased trabectedin cytotoxicity. In OC tumor xenografts the combination with maraviroc further reduced tumor growth, angiogenesis, and monocyte infiltration by trabectedin. In conclusion, this study offers a preclinical rationale for the use of maraviroc as new option to improve trabectedin activity in relapsed chemoresistant OC patients.

Overall, our results suggest that foretinib can target MDR-linked ABCB1 and ABCG2 transporters in clinical cancer therapy.

MX106-4C selectively kills ABCB1-positive MDR colorectal cancer cells via a novel ABCB1-dependent survivin inhibition mechanism, providing a clue for designing CS compound as an alternative strategy to overcome ABCB1-mediated colorectal cancer MDR.

In sum, we demonstrate that FN-1501 is a substrate of ABCB1 transporter from both in vivo and in vitro studies. Therefore, our findings provide new insight on the mechanism of chemoresistance due to ABCB1 overexpression.

Upregulation of ABCB1 through locus amplification represents a novel, conserved mechanism of PDAC paclitaxel resistance. Kinase inhibitors identified in this study can be further (pre) clinically explored as therapeutic strategies to overcome paclitaxel resistance in PDAC.

In conclusion, our results show that PYGO2 expression is significantly upregulated in MM patients carrying 1q21+ and that its expression is correlated with 1q21 copy number. Moreover, we found that the PYGO2-MDR1 axis is involved in the CFZ resistance in HMCLs MM cells suggesting that PYGO2 could be a possible future druggable target in 1q21+ MM patients.

This would be because the PARP inhibitors were still effective in inhibiting the DNA repair in Reh-IO-R cells where the DNA repair function was not augmented. [Conclusion]The combination of IO with PARP inhibitors synergized the antileukemic effect of IO by inhibiting DNA strand break repair in CD22-positive ALL cell lines and IO-resistant ALL cells, suggesting that these results may contribute to overcoming the IO resistance mechanisms.

In addition, Docking analysis revealed that Pemigatinib and ABCB1 have a high affinity for one another. This study concludes that Pemigatinib is capable of reversing the multidrug resistance mediated by ABCB1, offering ideas and references for the clinical application of Pemigatinib.

Although both the mutants were expressed at normal levels at the cell surface, the 6Y mutant failed to transport all the tested substrates except Bodipy-verapamil, whereas the 9Y mutant effluxed all tested substrates in a manner very similar to that of the wild-type protein...This is the first evidence for the existence of second-site suppressors in human P-gp that allow recovery of the loss of transport function caused by primary mutations. Further study of such mutations could facilitate mapping of the communication pathway between the substrate-binding pocket and the NBDs of P-gp and possibly other ABC drug transporters.

Importantly, SSE1806 overcame multidrug resistance in a cell line overexpressing MDR-1. Thus, SSE1806 represents a potential anticancer agent that can overcome multidrug resistance.

The results suggest that lysosome membranes anchored ABCC proteins which remained functionally active and were capable to load chemotherapeutics into lysosomes in paclitaxel-resistant cancer cells. Therefore, targeting of lysosomal ABCC transporters may help to overcome paclitaxel-induced resistance by reducing the accumulation of drugs in lysosomes.

No abstract available

The influence of ABC transporters was completely reversed by coadministration of the dual ABCB1/ABCG2 inhibitor elacridar, increasing the brain penetration in wild-type mice by 41-fold while no signs of acute CNS toxicity were observed. This binding could complicate interpretation of mouse studies, especially since humans lack circulating CES1 enzyme(s). Our results may be useful to further optimize the clinical safety and efficacy of adagrasib, and give more insight into potential drug-drug interactions risks.

An acquired resistance of OS to the chemotherapeutic agents might be due to the several mechanisms undergoing simultaneously on the single-cell level. This reveals the complexity of the mechanisms involved in the secondary resistance of OS to chemotherapies.

DLBCL might harbor certain molecular signatures such as MRP1/ABCC1, survivin, and BCRP/ABCC2 overexpression that can predict resistance to R-CHOP.

MAGI2-AS3 inhibited tumor growth and enhanced the suppressive effect of TMZ on glioma tumorigenesis in vivo. In conclusion, MAGI2-AS3 reverses TMZ resistance in glioma cells by inactivating the Akt pathway.

Additionally, treatment with Pola + Rit significantly enhanced antitumor activity in Pola-resistant STR-428 xenograft mouse models. Based on these results, Pola + Rit retreatment could have preserved efficacy because of the effect of Pola on sensitizing cells to Rit.

The compound, MK-2206, an inhibitor of the protein kinases AKT1/2/3, is undergoing evaluation in multiple clinical trials for the treatment of certain types of cancers, including those resistant to erlotinib...Methodology: The efficacy of MK-2206 (0.03-1 μM), in combination with the ABCB1 transporter sub-strates doxorubicin and paclitaxel, and ABCG2 transporter substrates mitoxantrone, SN-38 and topotecan, were determined in the cancer cell lines, KB-C2 and SW620/Ad300, which overexpress the ABCB1 transporter or H460/MX20 and S1-M1-80, which overexpress the ABCG2 transporter, respectively... These in vitro data indicated that MK-2206 surmounts resistance to mitoxantrone, SN-38 and topotecan in cancer cells overexpressing the ABCG2 transporter. If these results can be translated to humans, it is possible that MK-2206 could be used to surmount MDR in cancer cells overexpressing the ABCG2 transporter.

The administration of bixin or fucoxanthin decreases the expression of ABCC1 and ABCC2. Both carotenoids, either alone or in combination with cisplatin, upregulated p53 gene expression indicating the mechanism of proliferation inhibition and apoptosis occurs via the p53 caspase-independent pathway.

Overexpression of MDR1 abolished the impacts of lnc KCNQ1OT1 depletion on DOX resistance in BC. In conclusion, our results unveiled that in BC cells and DOX-resistant BC cells, lnc KCNQ1OT1 could be mediated by METTL3 through mA modification to elevate and stabilize its expression, further inhibiting miR-103a-3p/MDR1 axis to promote DOX resistance, which might provide novel thought to overcome DOX resistance in BC.

Chemoresistance to doxorubicin, cross-resistance to carboplatin, and the reversibility of the acquired resistance by the specific MDR1-inhibitor tariquidar were quantified in metabolic assays. Combination therapies aiming to inhibit MDR1 activity can now be screened for synergistic effects using our resistant sublines. Nevertheless, detailed resistance mechanisms and maintained molecular target expression in the resistant sublines are still to be examined.

NACT group treated with docetaxel (60 mg/m2), oxaliplatin (85 mg/m2), leucovorin (200 mg/m2), and 5-fluorouracil (2,600 mg/m2 as a 24 hr infusion), all given on day 1 and administered every 2 weeks before surgery. ERK1/2 and MDR1 found to over-express in stage III, predicts the degree of resistance and MDR phenotype in the GC patients.

Our study found that the mechanisms of resistance of PROTAC degraders can vary and may be dependent on drug concentrations. Such concepts may inform future clinical decision-making regarding drug dosing.

More than half of patients with DLBCL can achieve remission with standard R-CHOP regimes; however, approximately 30-40% of patients are still failing this standard therapy, which remains as an important cause of progression and mortality of this disease...The overexpression of BCL2, BCL6, VEGFR1 and TWIST1 was related to a minor EFS (p = 0.001). This study showed that in liquid biopsies analyzed, the presence of CTCs can be confirmed through molecular biomarkers, and it has an impact on OS and EFs, making this detection useful in the follow-up and prognosis of patients with DLBCL.

The restoration of the efficacy of antitumor medicines is a cornerstone in the combat with multidrug resistant (MDR) cancers. It was found that the most potent chemosensitizer among studied compounds preserves PARP1 inhibitory activity and attenuates cells' resistance to doxorubicin by inhibiting ABCB1 transporter activity. These results demonstrate that the conjugation of PARP inhibitors with selenophenoquinolinones is a prospective direction for the development of agents for the treatment of MDR cancers.