Inhibition of tumor-associated fatty acid synthase activity enhances vinorelbine (Navelbine)-induced cytotoxicity and apoptotic cell death in human breast cancer cells

The lipogenic enzyme fatty acid synthase (FAS) is differentially overexpressed and hyperactivated in a biologically aggressive subset of breast carcinomas and minimally in most normal adult tissues, rendering it an interesting target for anti-neoplastic therapy development. Current trends in the treatment of human breast cancer are with drug combinations that result in improved responses as well as the ability to use less toxic concentrations of the drugs. Here, we envisioned that combinations of conventional chemotherapeutic agents with novel compounds directed against breast cancer-associated FAS hyperactivity may provide increased efficacy over existing therapy for human breast cancer. Specifically, we examined the ability of the mycotoxin cerulenin, a potent and non-competitive inhibitor of FAS activity, to enhance the cytotoxic effects of vinorelbine (Navelbine), a derivative of vinca alkaloid that interferes with tubulin assembly and exhibits activity against metastatic breast cancer. SK-Br3, MCF-7 and MDA-MB-231 human breast cancer cell lines were employed as models of high, moderate and low levels of FAS ('cerulenin-target'), respectively. Combinations of cerulenin with vinorelbine were tested for synergism, additivity or antagonism using the isobologram and the median-effect plot (Chou-Talalay) analyses. Breast cancer cells were either simultaneously exposed to cerulenin and vinorelbine for 24 h or sequentially to cerulenin for 24 h followed by vinorelbine for 24 h. Concurrent exposure to cerulenin and vinorelbine resulted in synergistic interactions in MCF-7 and MDA-MB-231 cell lines, while additivity was found in SK-Br3 cells. Sequencing cerulenin followed by vinorelbine resulted in synergism for SK-Br3 and MDA-MB-231 cells, whereas it showed additive effects in MCF-7 cells. FAS activity blockade was found to synergistically enhance apoptosis-inducing activity of vinorelbine, as determined by an enzyme-linked immunosorbent assay for histone-associated DNA fragments. To the best of our knowledge this is the first study demonstrating that breast cancer-associated FAS is playing an active role in human breast cancer chemosensitivity. We suggest that pharmacological inhibition of FAS activity is a novel molecular approach to enhance the cytotoxic effects of existing chemotherapeutic agents in human breast cancer.     

Inhibition of Fatty Acid Synthase (FASN) synergistically enhances the efficacy of 5-fluorouracil in breast carcinoma cells

The lipogenic enzyme fatty acid synthase (FASN) is differentially overexpressed and hyperactivated in a biologically aggressive subset of breast carcinomas and minimally in most normal adult tissues, rendering it an interesting target for anti-neoplastic therapy development. We previously reported that the FASN blockade can induce a synergistic chemosensitization of breast cancer cells to microtubule interfering agents (MIAs) such as docetaxel, paclitaxel and vinorelbine. Upon pharmacological inhibition of FASN activity using the natural antibiotic cerulenin [(2S,3R)-2,3-epoxy-4-oxo-7E,10E-dodecadienamide], we evaluated the role of FASN-catalyzed endogenous fatty acid biogenesis on the sensitivity of SK-Br3, MCF-7 and MDA-MB-231 breast cancer cell lines to the anti-metabolite 5-fluorouracil (5-FU). Cells were exposed simultaneously to cerulenin and 5-FU, sequentially to 5-FU followed by cerulenin or cerulenin followed by 5-FU. Cell viability was determined by MTT assays and the increase in 5-FU-induced cell growth inhibition was measured by dividing 5-FU IC30 and IC50 values (i.e., 30% and 50% inhibitory concentrations, respectively) that were obtained in the absence of cerulenin by those in its presence. Co-exposure to cerulenin enhanced 5-FU efficacy up to 20-, 81-, and 58-times in SK-Br3, MCF-7 and MDA-MB-231 cells, respectively. Pre-treatment with cerulenin followed by the addition of 5-FU increased 5-FU efficacy up to 31-, 87-, and 126-times in SK-Br3, MCF-7 and MDA-MB-231 cells, respectively. Pre-treatment with 5-FU followed by the addition of cerulenin augmented 5-FU efficacy up to 107-, 20-, and 18-times in SK-Br3, MCF-7 and MDA-MB-231 cells, respectively. When isobologram transformations of multiple dose-response analyses were performed to detect in vitro synergy, we concluded that the nature of the interaction between cerulenin and 5-FU in individual breast cancer cells lines generally exhibited sequence-dependency. Thus, while synergism was mainly observed when breast cancer cells were exposed to 5-FU prior to cerulenin, moderate synergism or additive interactions was obtained either when the chemical FASN blocker preceded 5-FU or when both drugs were concurrently administered. Of note, no antagonist interactions occurred upon any schedule of combined treatment with cerulenin and 5-FU. Our current findings revealing a schedule-dependent synergistic interaction between 5-FU and cerulenin represents, to the best of our knowledge, the first evidence that FASN-catalyzed de novo FA biogenesis plays a key role in regulating breast cancer cell response to antimetabolite-based therapies.     

Exogenous supplementation with omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA; 22:6n-3) synergistically enhances taxane cytotoxicity and downregulates Her-2/neu (c-erbB-2) oncogene expression in human breast cancer cells.

Omega-3 polyunsaturated fatty acid (PUFA), docosahexaenoic acid (DHA; 22:6n-3) and other omega-3 and omega-6 PUFAs have raised interest as novel anticancer agents by exerting selective cytotoxic effects on human cancer cells without affecting normal tissues. Here, we examined the in vitro relationship between exogenous supplementation with DHA and breast cancer chemosensitivity to taxanes. We measured cell viability in the highly metastatic human breast cancer cell line MDA-MB-231 exposed sequentially to DHA followed by paclitaxel (Taxol) or docetaxel (Taxotere). As DHA by itself showed cytotoxic effects, possible synergistic interactions between DHA and taxanes were assessed, employing the combination index (CI) method and the isobologram analysis. Both methods showed a strong synergism (CI approximately 0.5; P<0.005) between DHA and taxanes in MDA-MB-231 cells. When the increase in taxanes efficacy was measured by dividing the IC50 values (50% inhibitory concentrations) obtained when the cells were exposed to taxanes alone by those after DHA pre-exposure, we found that DHA enhanced the cytotoxic activity of taxanes against MDA-MB-231 cells in a dose-dependent manner (up to 13- and 5-fold increase in Taxol and Taxotere efficacy, respectively). Importantly, sequential exposure to DHA followed by taxanes also yielded strong synergism in Her-2/neu (c-erbB-2)-overexpressing and taxanes-resistant SK-Br3 and BT-474 breast cancer cells. Moreover, exogenous supplementation with DHA significantly decreased the expression of Her-2/neu-codified p185(Her-2/neu) oncoprotein (up to 78% reduction in BT-474 cells). Our results provide experimental support to the hypothesis that omega-3 PUFAs can be used as modulators of tumor cell chemosensitivity and provide the rationale for in vivo preclinical investigation. In addition, this is the first study demonstrating that omega-3 PUFA DHA downregulates Her-2/neu oncogene expression in human breast cancer cells.     

Pharmacological inhibition of fatty acid synthase (FAS): a novel therapeutic approach for breast cancer chemoprevention through its ability to suppress Her-2/neu (erbB-2) oncogene-induced malignant transformation

We designed our experiments to evaluate whether fatty acid synthase (FAS), a lipogenic enzyme linked to tumor virulence in population studies of human cancer, is necessary for the malignant transformation induced by Her-2/neu (erbB-2) oncogene, which is overexpressed not only in invasive breast cancer but also in premalignant atypical duct proliferations and in ductal carcinoma in situ of the breast. To avoid the genetic complexities associated with established breast cancer cell lines, we employed NIH-3T3 mouse fibroblasts engineered to overexpress human Her-2/neu coding sequence. NIH-3T3/Her-2 cells demonstrated a significant upregulation of FAS protein expression, which was dependent on the upstream activation of mitogen-activated protein kinase and phosphatidylinositol 3'-kinase/AKT pathways. Remarkably, pharmacological FAS blockade using the mycotoxin cerulenin or the novel small compound C75 completely suppressed the state of Her-2/neu-induced malignant transformation by inhibiting the ability of NIH-3T3/Her-2 cells to grow under either anchorage-independent (i.e., to form colonies in soft agar) or low-serum monolayer conditions. Moreover, NIH-3T3/Her-2 fibroblasts were up to three times more sensitive to chemical FAS inhibitors relative to untransformed controls as determined by MTT-based cell viability assays. In addition, pharmacological FAS blockade preferentially induced apoptotic cell death of NIH-3T3/Her-2 fibroblasts, as determined by an ELISA for histone-associated DNA fragments and by the terminal deoxynucleotidyltransferase (TdT)-mediated nick end labeling assay (TUNEL). Interestingly, the degree of Her-2/neu oncogene expression in a panel of breast cancer cell lines was predictive of sensitivity to chemical FAS inhibitors-induced cytotoxicity, while low-FAS expressing and chemical FAS inhibitors-resistant MDA-MB-231 breast cancer cells became hypersensitive to FAS blockade when they were engineered to overexpress Her-2/neu. Our observations strongly suggest that inhibition of FAS activity may provide a new molecular avenue for chemotherapeutic prevention and/or treatment of Her-2/neu-related breast carcinomas.     

N-(4-hydroxyphenyl)-retinamide selectively increases All-TRANS retinoic acid inhibitory effects in HER2/NEU-overexpressing breast cancer cells.

We previously reported that overexpression of the HER2/NEU oncogene induces all-TRANS retinoic acid (ATRA) resistance in breast cancer cells. N-(4-hydroxyphenyl)-retinamide (4HPR), a synthetic analogue of ATRA, has been shown to repress the expression of HER2/neu and its family member, epidermal growth factor receptor (EGFR). We investigated whether 4HPR, by suppressing HER2/neu or EGFR expression, could sensitize breast cancer cells to ATRA. At 1.3 micro M concentration (a clinically pharmacologically achievable dose), 4HPR increased ATRA sensitivity synergistically in HER2/NEU-overexpressing BT-474, MDA-MB-453, and MCF-7/Her2 breast cancer cells. However, 4HPR did not sensitize EGFR-overexpressing MDA-MB-468, Hs578T, and MCF-7/EGFR breast cancer cells to ATRA. The increased inhibitory effects in HER2/NEU-overexpressing cells were not correlated with increases in expression levels of p21(WAF1/CIP1) or retinoblastoma protein. Combining 4HPR with ATRA may lead to a novel, selective therapeutic or chemopreventive strategy against HER2/NEU-overexpressing breast tumors.     

Influence of Neoadjuvant Therapy with Epirubicin and Docetaxel on the Expression of HER2/neu in Patients with Breast Cancer

BACKGROUND: In primary breast cancer, the expression levels of biological markers relevant to the progression of the disease may be altered by administration of anticancer drugs. Since neoadjuvant chemotherapy with epirubicin and docetaxel is increasingly used in advanced breast cancer, our purpose was to assess the influence of this neoadjuvant chemotherapy on the expression of the growth factor receptor HER2/neu. PATIENTS AND METHODS: We investigated changes of HER2/neu status by immunohistochemistry (IHC) and applied additional fluorescence in situ hybridization (FISH) in patients with potential modulation of HER2/neu status after administration of neoadjuvant chemotherapy with docetaxel and epirubicin in 97 breast cancer patients. The influence of neoadjuvant chemotherapy on HER2/neu expression was calculated by correlation of HER2/neu status before and after chemotherapy. RESULTS: The accuracy of HER2/neu assessment before and after neoadjuvant chemotherapy by IHC combined with FISH analysis in selected cases was 100%. The evaluation of HER2/neu status in these patients by IHC alone yielded accuracy of 93%. Neoadjuvant chemotherapy with epirubicin and docetaxel caused no significant modulation of HER2/neu status (p = 0.66). DISCUSSION: The administration of epirubicin and docetaxel in the neoadjuvant setting is not associated with significant changes of HER2/neu status in primary breast cancer. As a consequence, drug resistance or sensitivity is not induced by modulation of HER2/neu expression. Moreover, the time of assessment of the HER2/neu status is not a critical factor under neoadjuvant therapy with epirubicin and docetaxel.     

HER2/neu increases the expression of Wilms' Tumor 1 (WT1) protein to stimulate S-phase proliferation and inhibit apoptosis in breast cancer cells

High levels of the Wilms' Tumor 1 (WT1) protein and mRNA had been associated with aggressive phenotypes of breast tumors. Here we report that the HER2/neu oncogene increases WT1 expression. Approximately threefold higher levels of WT1 protein were observed in MCF-7 breast cancer cells transfected with the HER2/neu oncogene than in parental MCF-7 cells. Conversely, inhibition of HER2/neu with the anti-HER2/neu trastuzumab (Herceptintrade mark) antibody decreased WT1 protein levels in HER2/neu-overexpressing BT-474 and SKBr3 cells. We also found that HER2/neu engages Akt to regulate WT1 levels since inhibition of Akt reduced WT1 levels. Decreased expression of WT1 protein led to cell cycle arrest at the G1 phase and increased apoptosis in HER2/neu-overexpressing cells, which is correlated with decreased cyclin D1 and Bcl-2 levels. Our data indicate that HER2/neu engages Akt to increase WT1 expression, and that WT1 protein plays a vital role in regulating cell cycle progression and apoptosis in HER2/neu-overexpressing breast cancer cells.     

Silencing of the HER2/neu gene by siRNA inhibits proliferation and induces apoptosis in HER2/neu-overexpressing breast cancer cells

In eukaryotes, double-stranded (ds) RNA induces sequence-specific inhibition of gene expression referred to as RNA interference (RNAi). We exploited RNAi to define the role of HER2/neu in the neoplastic proliferation of human breast cancer cells. We transfected SK-BR-3, BT-474, MCF-7, and MDA-MB-468 breast cancer cells with short interfering RNA (siRNA) targeted against human HER2/neu and analyzed the specific inhibition of HER2/neu expression by Northern and Western blots. Transfection with HER2/neu-specific siRNA resulted in a sequence-specific decrease in HER2/neu mRNA and protein levels. Moreover, transfection with HER2/neu siRNA caused cell cycle arrest at G0/G1 in the breast cancer cell lines SK-BR-3 and BT-474, consistent with a powerful RNA silencing effect. siRNA treatment resulted in an antiproliferative and apoptotic response in cells overexpressing HER2/neu, but had no influence in cells with almost no expression of HER2/neu proteins like MDA-MB-468 cells. These data indicate that HER2/neu function is essential for the proliferation of HER2/neu-overexpressing breast cancer cells. Our observations suggest that siRNA targeted against human HER2/neu may be valuable tools as antiproliferative agents that display activity against neoplastic cells at very low doses.     

Pharmacological and small interference RNA-mediated inhibition of breast cancer-associated fatty acid synthase (oncogenic antigen-519) synergistically enhances Taxol (paclitaxel)-induced cytotoxicity

The relationship between breast cancer-associated fatty acid synthase (FAS; oncogenic antigen-519) and chemotherapy-induced cell damage has not been studied. We examined the ability of C75, a synthetic slow-binding inhibitor of FAS activity, to modulate the cytotoxic activity of the microtubule-interfering agent Taxol (paclitaxel) in SK-Br3, MDA-MB-231, MCF-7 and multidrug-resistant MDR-1 (P-Glycoprotein)-overexpressing MCF-7/AdrR breast cancer cells. When the combination of C75 with Taxol in either concurrent (C75 + Taxol 24 hr) or sequential (C75 24 hr --> Taxol 24 hr) schedules were tested for synergism, addition or antagonism using the isobologram and the median-effect plot analyses, co-exposure of C75 and Taxol mostly demonstrated synergistic effects, whereas sequential exposure to C75 followed by Taxol mainly showed additive or antagonistic interactions. Because the nature of the cytotoxic interactions was definitely schedule-dependent in MCF-7 cells, we next evaluated the effects of C75 on Taxol-induced apoptosis as well as Taxol-activated cell death and cell survival-signaling pathways in this breast cancer cell model. An ELISA for histone-associated DNA fragments demonstrated that C75 and Taxol co-exposure caused a synergistic enhancement of apoptotic cell death, whereas C75 pre-treatment did not enhance the apoptosis-inducing activity of Taxol. Co-exposure to C75 and Taxol induced a remarkable nuclear accumulation of activated p38 mitogen-activated protein kinase (p38 MAPK), which was accompanied by a synergistic nuclear accumulation of the p53 tumor-suppressor protein that was phosphorylated at Ser46, a p38 MAPK-regulated pro-apoptotic modification of p53. As single agents, FAS blocker C75 and Taxol induced a significant stimulation of the proliferation and cell survival mitogen-activated protein kinase extracellular signal-regulated kinase (ERK1/ERK2 MAPK) activity, whereas, in combination, they interfered with ERK1/ERK2 activation. Moreover, the combined treatment of C75 and Taxol inactivated the anti-apoptotic AKT (protein kinase B) kinase more than either agent alone, as evidenced by a synergistic down-regulation of AKT phosphorylation at its activating site Ser(473) without affecting AKT protein levels. To rule out a role for non-FAS C75-mediated effects, we finally used the potent and highly sequence-specific mechanism of RNA interference (RNAi) to block FAS-dependent signaling. Importantly, SK-Br3 and multi-drug resistant MCF-7/AdrR cells transiently transfected with sequence-specific double-stranded RNA oligonucleotides targeting FAS gene demonstrated hypersensitivity to Taxol-induced apoptotic cell death. Our findings establish for the first time that FAS blockade augments the cytotoxicity of anti-mitotic drug Taxol against breast cancer cells and that this chemosensitizing effect is schedule-dependent. We suggest that the alternate activation of both the pro-apoptotic p38 MAPK-p53 signaling and the cytoprotective MEK1/2 --> ERK1/2 cascade, as well as the inactivation of the anti-apoptotic AKT activity may explain, at least in part, the sequence-dependent enhancement of Taxol-induced cytotoxicity and apoptosis that follows inhibition of FAS activity in breast cancer cells. If chemically stable FAS inhibitors demonstrate systemic anticancer effects of FAS inhibition in vivo, these findings may render FAS as a valuable molecular target to enhance the efficacy of taxanes-based chemotherapy in human breast cancer.     

In vitro comparative evaluation of trastuzumab (Herceptin) combined with paclitaxel (Taxol) or docetaxel (Taxotere) in HER2-expressing human breast cancer cell lines.

BACKGROUND: Trastuzumab (Herceptin) has clinical indication in association with paclitaxel (Taxol) for the treatment of human epidermal growth factor receptor 2 (HER2)-expressing breast cancer. Synergistic interactions have been reported with taxane derivatives in HER2-expressing breast cancer cells. However, no direct comparison of the potential interest in combining trastuzumab with either paclitaxel or docetaxel (Taxotere) has been reported. MATERIALS AND METHODS: The present study was designed to evaluate in a comparative way the interaction of trastuzumab with paclitaxel or docetaxel in HER2-overexpressing human breast cancer cell lines. HER2 expression was documented in MCF-7, MDA-MB453 and SK-BR3 cell lines using immunocytochemistry with purified mouse anti-human monoclonal antibody. Cytotoxicity assays were performed using the sulforhodamine B assay and in vitro interactions between trastuzumab and taxanes were analyzed using the median-effect principle. RESULTS: Trastuzumab cytotoxicity was confirmed to be directly related to HER2 expression level. At the IC(50), the combination of trastuzumab with either paclitaxel or docetaxel led to synergism in all cell lines. However, considering mean values calculated in the IC(30)-IC(70) range of concentrations, trastuzumab interacted additively with docetaxel in SK-BR3 and MDA-MB453 cell lines while additive and synergistic interactions were achieved with paclitaxel in SK-BR3 and MDA-MB453, respectively. On the same basis, trastuzumab yielded synergistic interaction with both taxanes in the MCF-7 cell line. CONCLUSIONS: The present study shows that at least additive interactions are observed when trastuzumab is combined with either paclitaxel or docetaxel in weak to moderate or more than moderate HER2-expressing cells. Some interesting results were achieved in cells displaying weak HER2 expression which could suggest some further potential interest in trastuzumab.     

miR-125a增强多西他赛对乳腺癌生长的抑制作用

背景与目的:研究表明miR-125a通过下调Her-2或者Her-3的表达抑制乳腺癌细胞生长,可能是指导乳腺癌治疗的靶点.本研究旨在观察miR-125a是否具有增强多西他赛对乳腺癌细胞株和裸鼠荷瘤模型的生长抑制作用.方法:转染miR-125a联合不同浓度多西他赛处理MCF-7和MDA-MB-231乳腺癌细胞株和MDA-MB-231乳腺癌裸鼠模型,观察细胞株和裸鼠接种肿瘤的生长情况.结果:miR-125a与多西他赛可协同抑制MDA-MB-231及MCF-7乳腺癌细胞株、MDA-MB-231乳腺癌裸鼠模型肿瘤的增殖,单纯转染miR-125a也可抑制MDA-MB-231及MCF-7乳腺癌细胞株的增殖.结论:miR-125a与多西他赛有协同抗乳腺癌作用,可成为乳腺癌靶向治疗的潜在靶点.     

Protein kinase Calpha regulates Ets1 transcriptional activity in invasive breast cancer cells

We have previously shown that PKC inhibitors interfere with the Ets1/Smad3-dependent regulation of parathyroid hormone-related protein (PTHrP) P3 promoter activity by TGFbeta in invasive MDA-MB-231 breast cancer cells. By examining PKC expression in a variety of breast cancer cell lines, the protein level of PKCalpha was found to be much higher in Ets1-expressing MDA-MB-231 and MDA-MB-435 breast cancer cells than in Ets1-deficient MCF-7 and SK-BR3 cells. No correlation of Ets1 expression with the expression of other PKC subtypes (PKCbeta1, PKCbeta2, PKCdelta or PKCepsilon) could be observed. In contrast to MDA-MB-231 cells, PKCalpha-deficient MCF-7 cells do not support Ets1-induced activation of the PTHrP P3 promoter suggesting that PKCalpha may be important for Ets1 activity. A constitutively active form of PKCalpha was found to potentiate the P3 promoter activation by Ets1 alone and in synergy with Smad3. PKCalpha, but not PKCepsilon, also induced phosphorylation of the Ets1 protein. Both PKCalpha effects on Ets1 depended on the exon VII domain of Ets1. Using verapamil and ionomycin, we could show that PKCalpha induces Ets1 phosphorylation independent of calcium mobilization. Collectively, our data suggest that PKCalpha may regulate Ets1 activity in invasive breast cancer cells.     

HER2/neu reduces the apoptotic effects of N-(4-hydroxyphenyl)retinamide (4-HPR) in breast cancer cells by decreasing nitric oxide production

The retinoid N-(4-hydroxyphenyl)retinamide (4-HPR also known as fenretinide) is a potent inducer of apoptosis in breast cancer cells. We observed a 4.5-fold reduction in 4-HPR-mediated apoptosis in MCF-7 breast cancer cells transfected with HER2/neu (MCF-7/HER2) as compared with the parental MCF-7 (MCF-7/WT) cells. Blocking HER2/neu with trastuzumab (Herceptin) led to a six-fold increase in 4-HPR-induced apoptosis in HER2/neu-overexpressing cells. These data indicate that HER2/neu reduces the sensitivity of breast cancer cells to 4-HPR. We showed previously that nitric oxide (NO) is essential for 4-HPR to induce apoptosis in breast cancer cells. The inhibitory effects of the 4-HPR and trastuzumab combination correlated with the amount of NO produced in HER2/neu-overexpressing cells. When a NO synthase (NOS) inhibitor was used to block NO production, decreased apoptosis by the 4-HPR and trastuzumab combination was observed. Furthermore, 4-HPR-mediated NOSII expression was lower in MCF-7/HER2 than MCF-7/WT cells, but was increased by trastuzumab in HER2/neu-overexpressing cells. Here we report the novel findings that HER2/neu reduces the ability of 4-HPR to induce apoptosis in breast cancer cells, and that one mechanism by which HER2/neu increases the resistance of breast cancer cells to 4-HPR is by decreasing NOSII-mediated NO production.     

Effects of ulinastatin and docetaxel on breast cancer invasion and expression of uPA,uPAR and ERK

Objective

To investigate the effects of ulinastatin and docetaxel on invasion of breast cancer cells and expression of uPA, uPAR and ERK, breast cancer MDA-MB-231 and MCF-7 cells.

Methods

The nude mice were treated with PBS, ulinastatin, docetaxel, and ulinastatin plus docetaxel, respectively. Their effects on 1) cell invasion ability was assayed using Transwell; 2) expression of uPA, uPAR and ERK was detected by real time PCR and Western blot; 3) uPA, uPAR and p-ERK protein level in nude mice was quantified by immunohistochemistry.

Results

1) Treatment with ulinastatin, docetaxel, and ulinastatin plus docetaxel, respectively, significantly inhibited MDA-MB-231 and MCF-7 cell invasion; 2) mRNA and protein levels of uPA, uPAR and ERK1/2 were inhibited by ulinastatin, but enhanced by docetaxel.

Conclusion

Ulinastatin can enhance the effects of docetaxel on invasion of breast cancer cells. And that uPA, uPAR and p-ERK expression is obviously inhibited by ulinastatin.