Resistance to Cabazitaxel

We studied mechanisms of resistance to the novel taxane cabazitaxel in established cellular models of taxane resistance. We also developed cabazitaxel-resistant variants from MCF-7 breast cancer cells by stepwise selection in drug alone (MCF-7/CTAX) or drug plus the transport inhibitor PSC-833 (MCF-7/CTAX-P). Among multidrug-resistant (MDR) variants, cabazitaxel was relatively less cross-resistant than paclitaxel and docetaxel (15- vs. 200-fold in MES-SA/Dx5 and 9- vs. 60-fold in MCF-7/TxT50, respectively). MCF-7/TxTP50 cells that were negative for MDR but had 9-fold resistance to paclitaxel were also 9-fold resistant to cabazitaxel. Selection with cabazitaxel alone (MCF-7/CTAX) yielded 33-fold resistance to cabazitaxel, 52-fold resistance to paclitaxel, activation of ABCB1, and 3-fold residual resistance to cabazitaxel with MDR inhibition. The MCF-7/CTAX-P variant did not express ABCB1, nor did it efflux rhodamine-123, BODIPY-labeled paclitaxel, and [3H]-docetaxel. These cells are hypersensitive to depolymerizing agents (vinca alkaloids and colchicine), have reduced baseline levels of stabilized microtubules, and impaired tubulin polymerization in response to taxanes (cabazitaxel or docetaxel) relative to MCF-7 parental cells. Class III β-tubulin (TUBB3) RNA and protein were elevated in both MCF-7/CTAX and MCF-7/CTAX-P. Decreased BRCA1 and altered epithelial–mesenchymal transition (EMT) markers are also associated with cabazitaxel resistance in these MCF-7 variant...
Source: Molecular Cancer Therapeutics - Category: Cancer & Oncology Authors: Tags: Cancer Biology and Signal Transduction Source Type: research

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In this study, we found that a methanol extract of the leaves and branches of P. indica L. (MEPI) caused cellcycle arrest at the sub-G1 phase and induced apoptosis, as indicated by the activation of caspase-8, -3, -7, and c-PARP. Western blotting revealed that MEPI significantly reduced the levels of markers of the epithelial-mesenchymal transition, such as Vimentin, Snail, Slug, and matrix metallopeptidase 9. Notably, the expression of multidrug resistance-associated protein 1 in triple negative breast cancer (TNBC) was significantly decreased by MEPI. Moreover, the co-treatment with MEPI and doxorubicin resulted in a syn...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research
Breast cancer resistance protein (BCRP) and multidrug resistance protein 4 (MRP4) are involved in uric acid excretion in humans and mice. Despite evidence suggesting that renal proximal tubular epithelial cell...
Source: BMC Veterinary Research - Category: Veterinary Research Authors: Tags: Research article Source Type: research
In this study we tested the clinoptilolite, chabazite, and natrolite ability to be loaded by antitumor ribonuclease binase and the cytotoxicity of the obtained complexes. We found the optimal conditions for binase loading into zeolites and established the dynamic of its release. Cytotoxic effects of zeolite-binase complexes toward colorectal cancer Caco2 cells were characterized after 24 and 48 h of incubation with cells using MTT-test. Zeolites were toxic by itselfs and reduced cells viability by 30% (clinoptilolite), 40% (chabazite), and 70% (natrolite) after 48 h of incubation. Binase complexes with clinoptilolite as we...
Source: Frontiers in Pharmacology - Category: Drugs & Pharmacology Source Type: research
In conclusion, e-As4S4 holds great potential for an alternative therapeutics in the treatment of breast cancer, due to its unique function of correcting the aggressive microenvironment. Introduction Metastasis is the leading cause of breast cancer mortality, which has been one major challenge in clinical treatment (1). In particular, triple-negative breast cancer (TNBC) is characterized by the absence of estrogen receptors (ER), progesterone receptors (PR) and HER2 receptors, which is one of the most aggressive types of breast cancers, marked by high rates of relapse, visceral metastases and early death (2, 3). The...
Source: Frontiers in Oncology - Category: Cancer & Oncology Source Type: research
Conclusion Several TISC-based immunotherapeutic approaches are under development in various stages of preclinical studies. As outlined in this review article, a careful and more exhaustive genetic and metabolic understanding of TISC-associated phenotypes is critical to develop novel TISC based immunotherapies. Various components within the tumor microenvironment such as tumor cells, infiltrating immune cells, and supporting stromal cells impact the TISC metabolism. This unique metabolic profile leads to upregulation of certain enzymes and proteins such as ALDH1, CEP55, IDO COA1 etc., which can be utilized for development ...
Source: Frontiers in Oncology - Category: Cancer & Oncology Source Type: research
Conclusion and Perspective With in-depth understandings of antibodies, linkers, and payloads, ADCs have also achieved great development. The linkage strategy and target diversity have already improved the delivery of the payloads to tumor tissues and reduced exposure to normal tissues. With the development of payloads, some novel potent payloads are used by ADCs, which allows researchers to exploit novel linkers to attach the antibody and payloads without disturbing their potency (Dragovich et al., 2018). Furthermore, some irrelevant antigen-target ADCs also may exert toxicity to tumor cells due to the vascular gap of tum...
Source: Frontiers in Pharmacology - Category: Drugs & Pharmacology Source Type: research
Chan Feng1, Donglei Zhu1, Lv Chen1, Yonglin Lu1, Jie Liu1, Na Yoon Kim2, Shujing Liang1, Xia Zhang1, Yun Lin1, Yabin Ma3* and Chunyan Dong1* 1Cancer Center, Shanghai East Hospital, Tongji University, Shanghai, China 2Department of Chemical Engineering, Northeastern University, Boston, MA, United States 3Pharmacy Department, Shanghai East Hospital, Tongji University, Shanghai, China The off-target activation of photosensitizers is one of the most well-known obstacles to effective photodynamic therapy (PDT). The selected activation of photosensitizers in cancer cells is highly desired to overcome this problem. We...
Source: Frontiers in Pharmacology - Category: Drugs & Pharmacology Source Type: research
Discussion Suppressor of cytokine signaling 1 is an essential molecule for maintaining immune homeostasis and subverting inflammation. Disorders arising from excess inflammation or SOCS1 deficiency can be potentially treated with SOCS1 mimetics (Ahmed et al., 2015). While SOCS1 has promising potential in many disorders, it should be noted that new targets and actions of SOCS1 are still being discovered and not all the effects of this protein are beneficial in autoimmune diseases and cancer. For instance, SOCS1 degrades IRS1 and IRS2, required for insulin signaling, via the SOCS Box domain, thus, limiting its potential in ...
Source: Frontiers in Pharmacology - Category: Drugs & Pharmacology Source Type: research
In conclusion, osmotic burst of inflated complement-damaged cells may occur, but these bursts are most likely a consequence of metabolic collapse of the cell rather than the cause of cell death. The Complement Cell Death Mediator: A Concerted Action of Toxic Moieties Membrane pores caused by complement were first visualized by electron microscopy on red blood cell membranes as large ring structures (22). Similar lesions were viewed on E. coli cell walls (23). Over the years, ample information on the fine ultrastructure of the MAC that can activate cell death has been gathered (24) and has been recently further examined (...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
CONCLUSION: Our results reveal that GTSE1 played a key role in the progression of breast cancer, indicating that GTSE1 could serve as a novel biomarker to aid in the assessment of the prognosis of breast cancer. PMID: 30961661 [PubMed - in process]
Source: Clinical Breast Cancer - Category: Cancer & Oncology Authors: Tags: J Exp Clin Cancer Res Source Type: research
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