Comparative proteomic analysis of paclitaxel resistance-related proteins in human breast cancer cell lines

Abstract

Abstract. Paclitaxel is widely used to treat various cancers; however, resistance to this drug is a major obstacle to breast cancer chemotherapy. To identify the proteins involved in paclitaxel resistance, the present study compared the proteomes of MCF-7 human breast cancer cells and its paclitaxel-resistant subclone MCF-7/PTX. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry, 11 upregulated and 12 downregulated proteins were identified in MCF-7/PTX cells compared with the parental cell line. These 23 proteins were functionally classified as stress-induced chaperones, metabolic enzymes and cytoskeletal proteins. The anti-apoptotic proteins, stress-70 protein, 78-kD glucose-regulated protein, peptidyl-prolyl cis-trans isomerase A (PPIA) and heterogeneous nuclear ribonucleoprotein H3, were also upregulated in MCF-7/PTX cells. Notably, knockdown of the stress-response chaperone PPIA using small interfering RNA in MCF-7/PTX cells restored their sensitivity to paclitaxel. These findings indicated that PPIA may have an important role in paclitaxel resistance in MCF-7/PTX cells. IntroductionTaxanes, including paclitaxel and docetaxel, are microtubule-stabilizing agents that are widely used to treat various cancers. Taxane-resistant breast cancer is common; therefore, the identification of resistance markers and a detailed understanding of the mechanisms mediating paclitaxel resistance are required to develop optimal treatment strategies and to identify responsive patients (1). A previous study described at least three potential mechanisms of paclitaxel resistance (2). The first involves decreased intracellular drug accumulation caused by the overexpression of membrane-bound drug efflux proteins, such as P-glycoprotein. However, clinical trials focusing on P-glycoprotein inhibitors as chemosensitizing agents did not report promising outcomes for patients with relapsing solid tumors and hematological malignancies (3). The other two mechanisms involve mutations in β-tubulin and overexpression of β-tubulin isotypes (2). For example, numerous studies reported that mutations in the paclitaxel-binding sites of β-tubulin were associated with drug resistance, while other studies were unable to detect these mutations in paclitaxel-resistant breast cancers (4-7). Overexpression of β-tubulin isotypes occurs in a restricted number of patients with paclitaxel-resistant ovarian cancer and occasionally in patients with breast cancer; however, knockdown of β-tubulin expression by RNA interference had no effect on the sensitivity of paclitaxel-resistant ovarian cancer cells (6,8,9). Therefore, the proposed mechanisms of paclitaxel resistance remain controversial.Global analysis of gene expression using cDNA microarray is often used to determine the molecular mechanisms underlying drug resistance. Since the correlation between mRNA abundance and protein levels is poor, proteome analysis is considered superior to cDNA microarrays for the analysis of cell function. ...

Stress-inducible gene Atf3 in the noncancer host cells contributes to chemotherapy-exacerbated breast cancer metastasis

“…Our data suggest that Atf3 in the noncancer host cells is a key gene mediating this process. Interestingly, peptidyl-prolyl cis-trans isomerase A (PPIA), a stressresponse chaperone in cancer cells, was shown to play an important role in the ability of cancer cells to resist PTX (68). Thus, a stress response in both noncancer cells (our study) and cancer cells (the PPIA study) can counteract chemotherapy.…”

Hydrous icaritin nanorods with excellent stability improves the in vitro and in vivo activity against breast cancer

“…Antitumor treatment was performed on MCF-7 tumor-bearing nude mice model using PTX injection as a positive control (Fujioka et al, 2017;Zheng et al, 2017). As seen in Figure 5(A, B), daily oral administration of free HICT (35 mg/ kg) showed no antitumor effect with a similar tumor growth profile to that of normal saline group, probably due to its poor solubility and oral bioavailability of HICT suspensions even in the presence of TPGS and SO.…”

Proteomics-based insights into mitogen-activated protein kinase inhibitor resistance of cerebral melanoma metastases

“…Nr. Protein name Gene name log 2 fold change (t-test difference) upregulated in poor responder p value t-test significant Functional role P21266 Glutathione S-transferase Mu 3 GSTM3 2.68 7.13E − 07 * Uptake and detoxification of endogenous compounds and xenobiotics at the blood brain barrier [ 80 ]; many anticancer drugs are substrates for GST and, therefore, overexpression of GST is responsible for resistance to anti-cancer drugs in tumor cell lines [ 81 ] P61962 DDB1- and CUL4-associated factor 7 DCAF7 2.06 1.11E − 07 * Substrate receptor for a ubiquitin-protein ligase complex; involved in the pathway protein ubiquitination; involved in normal and disease skin development [ 82 ]; has been shown to function as a scaffold protein for protein complexes involved in kinase signalling [ 83 ] P62937 Peptidyl-prolyl cis–trans isomerase A PPIA 0.75 4.98E − 07 Upregulated in resistant human breast cancer cell line (vs. sensitive cell line) [ 84 ]; PPIases accelerate the folding of proteins; catalyzes the cis–trans isomerization of proline imidic peptide bonds in oligopeptides [ 85 ] Q16864 V-type proton ATPase subunit F ATP6V1F 3.12 5.47E − 07 * V-ATPases are responsible for acidifying intracellular compartments [ 86 ]; an acidic environment leads to inactivation of T cells [ 56 , 57 ]; supports the hypothesis that resistance is caused by the tumor inactivating immune cells Q6FI81 Anamorsin CIAPIN1 …”