Docetaxel: a new active agent in the therapy of metastatic breast cancer

Chitosan: A versatile bio-platform for breast cancer theranostics

Breast cancer is considered one of the utmost neoplastic diseases globally, with a high death rate of patients. Over the last decades, many approaches have been studied to early diagnose and treat it, such as chemotherapy, hormone therapy, immunotherapy, and MRI and biomarker tests; do not show the optimal efficacy. These existing approaches are accompanied by severe side effects, thus recognizing these challenges, a great effort has been done to find out the new remedies for breast cancer. Main finding: Nanotechnology opened a new horizon to the treatment of breast cancer. Many nanoparticulate platforms for the diagnosis of involved biomarkers and delivering antineoplastic drugs are under either clinical trials or just approved by the Food and Drug Administration (FDA). It is well known that natural phytochemicals are successfully useful to treat breast cancer because these natural compounds are safer, available, cheaper, and have less toxic effects. Chitosan is a biocompatible and biodegradable polymer. Further, it has outstanding features, like chemical functional groups that can easily modify our interest with an exceptional choice of promising applications. Abundant studies were directed to assess the chitosan derivative-based nanoformulation's abilities in delivering varieties of drugs. However, the role of chitosan in diagnostics and theranostics not be obligated. The present servey will discuss the application of chitosan as an anticancer drug carrier such as tamoxifen, doxorubicin, paclitaxel, docetaxel, etc. and also, its role as a theranostics (i.e. photo-responsive and thermo-responsive) moieties. The therapeutic and theranostic potential of chitosan in cancer is promising and it seems that to have a good potential to get to the clinic.

Long non-coding RNAs are emerging targets of phytochemicals for cancer and other chronic diseases

The long non-coding RNAs (lncRNAs) are the crucial regulators of human chronic diseases. Therefore, approaches such as antisense oligonucleotides, RNAi technology, and small molecule inhibitors have been used for the therapeutic targeting of lncRNAs. During the last decade, phytochemicals and nutraceuticals have been explored for their potential against lncRNAs. The common lncRNAs known to be modulated by phytochemicals include ROR, PVT1, HOTAIR, MALAT1, H19, MEG3, PCAT29, PANDAR, NEAT1, and GAS5. The phytochemicals such as curcumin, resveratrol, sulforaphane, berberine, EGCG, and gambogic acid have been examined against lncRNAs. In some cases, formulation of phytochemicals has also been used. The disease models where phytochemicals have been demonstrated to modulate lncRNAs expression include cancer, rheumatoid arthritis, osteoarthritis, and nonalcoholic fatty liver disease. The regulation of lncRNAs by phytochemicals can affect multi-steps of tumor development. When administered in combination with the conventional drugs, phytochemicals can also produce synergistic effects on lncRNAs leading to the sensitization of cancer cells. Phytochemicals target lncRNAs either directly or indirectly by affecting a wide variety of upstream molecules. However, the potential of phytochemicals against lncRNAs has been demonstrated mostly by preclinical studies in cancer models. How the modulation of lncRNAs by phytochemicals produce therapeutic effects on cancer and other chronic diseases is discussed in this review.

Early neutropenia on day 8 treated with adjuvant Docetaxel-based chemotherapy in early breast cancer patients: Putative mechanisms within the neutrophil pool system

Most chemotherapy regimens cause neutropenic nadirs between days 10 and 14, and administration of granulocyte colony-stimulating factor (G-CSF) support relies on this timing. In docetaxel (DOC)-based chemotherapy, the frequency of febrile neutropenia (FN) and the G-CSF dose administered varied greatly between studies. Our study goal was to forecast the necessary dose of G-CSF by comparing day 8 neutropenia with putative changes within the neutrophil pool. We conducted a retrospective observational analysis of 242 early breast cancer patients who had received adjuvant DOC-based chemotherapy (DOC group) compared with 43 patients who had received FEC chemotherapy (FEC group). Patients who were given a standard dose and had a blood test on day 8 in the 1st cycle were eligible. In the DOC group, patients routinely received prophylactic administration of G-CSF (150 μg/body) on day 3 and received additional G-CSF based on a blood test on day 8. Results of the day 8 blood test showed that severe neutropenia (<500/mm3, average 494/mm3) was observed in 152 out of 242 (62.8%) patients in the DOC group, while in the FEC group (n = 43), neutropenia was ambiguous (average 1,741/mm3). In the FEC group, 9 out of 43 patients (20.9%) and in the DOC group, 27 out of 242 patients (11.1%) experienced FN. In the DOC group, day 8 neutropenia was predictive for FN in a logistic regression model (OR 0.79 [95% CI: 0.655-0.952], p = 0.013). Among 214 patients under 70 years old, the planned chemotherapy cycle was completed in 190 (88.8%) patients who also received the maximum dose of G-CSF (150 μg/body) four times, while 23 patients could not complete the planned chemotherapy cycle, but only five because of FN-related complications. Patients treated with DOC should be treated for primary prophylaxis with G-CSF support at an earlier time starting with a relatively small dose.

ST6Gal-I modulates docetaxel sensitivity in human hepatocarcinoma cells via the p38 MAPK/caspase pathway

The β-galactoside α2-6-sialyltransferase 1 (ST6Gal-I) is the principal sialyltransferase responsible for the addition of α2-6-sialic acid to the termini N-glycans on cell surface. Although ST6Gal-I in cancer cell resistance to chemotherapeutics agents has been previously reported, the role of ST6Gal-I in clinical drug resistance of hepatocellular carcinoma (HCC) is not fully understood. In this study, we found that knockdown of ST6Gal-I increased the sensitivity of hepatocarcinoma MHCC97-H cells to docetaxel treatment by instigating the process of apoptosis. Silencing ST6Gal-I expression decreased the survival rate of MHCC97-H cells after docetaxel treatment. Importantly, ST6Gal-I silencing resulted in an increasing of phospho-p38, Bax, Bad, cytochrome c and the cleaved caspase-9, 3 and PARP, while a decreasing of the anti-apoptotic protein Bcl-2. In addition, we found that p38 MAPK and caspase-3 inhibitors can reduce the enhanced apoptosis levels of MHCC97-H cells resulted by either ST6Gal-I silencing or docetaxel treatment. Conversely, exogenous expression of ST6Gal-I in hepatocarcinoma Huh7 cells inhibited apoptotic cell death and prevented docetaxel-induced apoptosis by inhibiting p38 MAPK mediated mitochondrial-dependent pathway. Taken together, these results indicate that ST6Gal-I might play a positive role in mediating the survival of human hepatocarcinoma cells and could be a potential target for gene and antitumor drugs therapy.

Paclitaxel alleviated liver injury of septic mice by alleviating inflammatory response via microRNA-27a/TAB3/NF-κB signaling pathway

Excessive inflammatory response and apoptosis play an important role in the sepsis-induced liver injury. Paclitaxel, a diterpene alkaloid of Taxus brevifolia, is widely used as an anti-tumor drug and shows protective effects on acute lung and kidney injury. However, whether it has a protective effect against sepsis-induced liver injury has not been reported. The objective of this study was to investigate the protective effects of paclitaxel in septic liver injury in mice and associated molecular mechanisms. Our results showed that paclitaxel treatment improved LPS-induced liver injury, as evidenced by the reduced aminotransferase activity, histological scores and apoptosis in the liver tissues. This was accompanied by the alleviating of inflammation and oxidative stress, such as decreased levels of tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-6) interleukin-1β (IL-1β) and malondialdehyde (MDA) and increased levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) in serum and liver tissues. Subsequent microarray and qRT-PCR analysis further showed that miR-27a was significantly decreased in mice with sepsis, which was recovered by paclitaxel pretreatment. Antagomir-miR-27a suppressed the therapeutic effects of paclitaxel in mice liver injury model via promoting inflammatory response. Of note, TAB3, which participated in the activation of the NF-κB signaling pathway, was identified as a direct target of miR-27 by luciferase reporter gene assays. Then, we revealed a reverse relationship between miR-27a expression levels and TAB3 mRNA levels in liver tissues from septic mice. Furthermore, paclitaxel treatment significantly decreased the expression of NF-κB p65, but increased inhibitor of nuclear factor-κB-α (IκBα) protein levels in septic mice, suggesting the inactivation of NF-κB signaling pathway. Notably, the inhibitory effects of paclitaxel on NF-κB signaling pathway were reversed by antagomir-miR-27a. Our data indicated that paclitaxel significantly attenuated septic induced liver injury through reducing inflammatory response via miR-27a/TAB3/NF-κB signaling pathway.

MicroRNAs mediate therapeutic and preventive effects of natural agents in breast cancer

MicroRNAs (miRNAs) are a set of non-coding small RNA molecules that play a critical role in regulation of protein coding genes in cells. MiRNAs have been extensively studied as novel biomarkers, therapeutic targets, and new drugs in various human diseases. Breast cancer is a one of the leading tumor types significantly affecting women health worldwide. Over the past decade, a number of natural agents, such as paclitaxel and curcumin, have been applied for treatment and prevention of breast cancer due to their relatively low toxicity. However, the mechanisms of action have not been completely understood. Investigation on miRNAs is able to potentially provide a novel insight into better understanding the anticancer activities of these natural products. Given that a single miRNA can target multiple genes, theoretically, those genes involved in a certain phenotype can be clustered with one or a few miRNAs. Therefore, pleiotropic activities of natural agents should be interpreted by interactions between selected miRNAs and their targets. In this review, we summarize the latest publications related to the alterations of miRNAs by two natural agents (paclitaxel and curcumin) that are currently used in intervention of breast cancer, and conclude that the mechanism involving the regulation of miRNA expression is one of the keys to understand pleiotropic activities of natural agents.

Taxane chemotherapy treatment for metastatic breast cancer

SUMMARY The taxanes, paclitaxel, docetaxel and nab-paclitaxel, are among the most active cytotoxic agents for treatment of breast cancer. Significant progress has been made in addressing taxane dose and schedule in both early-stage and metastatic disease. Several studies have clarified the role of retreatment with taxanes in recurrent breast cancer patients previously treated with taxane-containing regimens. In addition, the advent of nab-paclitaxel, designed to reduce allergic reactions and enhance drug delivery to tumor cells, has provided additional therapeutic options. This article summarizes the uses of taxanes in the treatment of metastatic breast cancer.

A literature-based meta-analysis taxane-based doublet versus single-agent taxane chemotherapy in patients with advanced breast cancer

PURPOSE

Clinical trials have reported conflicting results as to whether taxane-based doublet improves outcome over single-agent taxane in patients with advanced breast cancer.

METHODS

We performed a meta-analysis comparing primary and secondary end points of taxane-based doublet with single-agent taxane chemotherapy in patients with advanced breast cancer and prior anthracycline treatment. The event-based relative risk ratio (RR) with 95% confidence intervals (95% CI) was derived, and a test of heterogeneity was applied.

RESULTS

Four eligible trials (2,343 patients) were selected from 488 studies that initially were identified. A significant difference in favoring taxane-based doublet over single-agent taxane was observed in progression-free survival (PFS) (RR, 1.33; 95% CI, 1.02-1.75; P = 0.039) and partial response (PR) (RR, 1.43; 95% CI, 1.10-1.86; P = 0.008). The ORR was higher for patients receiving taxane-based doublet, although not statistically significant (RR, 1.17; 95% CI, 0.91-1.50; P = 0.220). Whereas there was no difference in 1-year survival rate (1-year SR) (RR, 1.05; 95% CI, 0.94-1.17; P = 0.422), clinical benefit (CB) (RR, 1.02; 95% CI, 0.95-1.09; P = 0.642), and complete response (CR) (RR, 0.75; 95% CI, 0.31-1.79; P = 0.512). Toxicities did not differ significantly except stomatitis and diarrhea.

CONCLUSION

Taxane-based doublet appeared to improve PFS and PR compared with single-agent taxane in the treatment of patients with advanced breast cancer. Further prospective, randomized, controlled trials will be necessary.

Class III beta-tubulin isotype predicts response in advanced breast cancer patients randomly treated either with single-agent doxorubicin or docetaxel

PURPOSE

To evaluate the role of microtubule-associated variables as potential predictors of response and clinical outcome in patients with advanced breast cancer receiving single-agent docetaxel or doxorubicin chemotherapy.

EXPERIMENTAL DESIGN

The analysis was done on 173 tumor samples from patients with locally advanced or metastatic breast cancer who have participated in the TAX-303 phase III trial in which patients were randomly assigned to receive docetaxel or doxorubicin. Expression of total alpha- and beta-tubulin, classes II to IV beta-tubulin isotypes, and tau protein was evaluated by immunohistochemistry on formalin-fixed, paraffin-embedded tumors from the primary breast cancer.

RESULTS

We observed that patients with "high" expression of class III beta-tubulin isotype had a higher probability of response to docetaxel than to doxorubicin treatment (odds ratio, 1.9; 95% confidence interval, 1.01-3.7; P = 0.05). No difference was observed in terms of time to progression or in terms of overall survival.

CONCLUSIONS

This study suggests that the superiority of docetaxel over doxorubicin seems to be confined to the subgroup of patients with "high" expression of class III beta-tubulin isotype.

Evaluation of therapeutic efficacy of capecitabine on human breast carcinoma tissues and cell lines in vitro

BACKGROUND

Capecitabine, an oral anticancer prodrug, was associated with relatively mild degrees of side effects, notably low myelosuppression. Previous studies demonstrated capecitabine monotherapy as safe and very useful for recurrent and advanced metastatic breast cancer patients who are generally associated with a poor prognosis.

MATERIALS AND METHODS

Capecitabine and two conventional cytotoxic antineoplastic drugs (epirubicin and docetaxel) were employed in this study in order to compare their therapeutic antineoplastic effects. The tumour tissues obtained from 42 patients and breast carcinoma cell lines were treated with the chemotherapeutic agents above in vitro. Their efficacy was determined using ATP Bioluminescence assay which measures the metabolic rate, WST-1 assay that could quantify the inhibition of cell proliferation and immunohistochemical studies. The proapoptotic effects was examined using in situ apoptosis kit.

RESULTS

Both solid tumour and cell lines treated by capecitabine as well as two drugs above demonstrated a significant decrement in metabolic and proliferation rates. However, capecitabine treatment resulted in significant increment of the number of the tumour cells undergoing apoptosis.

CONCLUSION

Results of our present study demonstrated that capecitabine could be a useful agent against breast cancer cells with less side effects and its inhibition of cell proliferation of breast carcinoma is at least similar to that of two other commonly used cytotoxic drugs.

Phase I dose-finding and pharmacokinetic study of docetaxel and vinorelbine as first-line chemotherapy for metastatic breast cancer

BACKGROUND AND PURPOSE

Anthracycline-containing regimens are widely used in advanced breast cancer. However, there is a need for new, non-anthracycline regimens that are active in patients for whom anthracyclines are contraindicated. The aim of this study was to determine the maximum tolerated dose (MTD), the dose-limiting toxicities (DLTs) and recommended doses of docetaxel and vinorelbine as first-line chemotherapy in patients with metastatic breast cancer. The pharmacokinetics of both drugs was also evaluated.

PATIENTS AND METHODS

Thirty-four women with first-line metastatic breast cancer were treated with docetaxel, 60-100 mg/m2 (day 1), and vinorelbine, 20-22.5 mg/m2 (days 1 and 5), repeated every three weeks and administered on an outpatient basis.

RESULTS

Two MTDs were determined: MTD1 was defined at the dose level using docetaxel 75 mg/m2, and vinorelbine 22.5 mg/m2 DLT being a grade 3 stomatitis that was more related to the dose of vinorelbine than that of docetaxel. Therefore, the study continued with a fixed dose of vinorelbine, 20 mg/m2, and docetaxel 85-100 mg/m2. MTD2 was defined at the dose level combining docetaxel, 100 mg/m2, and vinorelbine, 20 mg/m2; DLTs were grade 3 stomatitis and severe asthenia. Fluid retention was observed in 41% of patients but was never severe or a reason for patient discontinuation. In comparison with historical experience, Daflon 500 did not seem to increase the efficacy of the three-day corticosteroid premedication by further reducing the incidence or severity of fluid retention. No significant neurotoxicity was observed and no patient discontinued the study due to this site effect. Activity was observed at all dose levels and at all metastatic sites, with an overall response rate of 71% (95% CI: 52.0%-85.8%). The median time to progression was 31.4 weeks (95% CI: 12-48 weeks) and median survival was 15.6 months (95% CI: 2.6-26.6 months). The pharmacokinetics of docetaxel and vinorelbine were not modified between day 1 and day 3 when the two drugs were combined with the day 1 administration schedule used in this study.

CONCLUSION

The recommended doses for phase II studies are docetaxel, 75 mg/m2 (day 1), plus vinorelbine, 20 mg/m2 (days 1 and 5), repeated every three weeks. At these doses, the combination was found to be active and well tolerated.

Prospective randomized trial of docetaxel versus doxorubicin in patients with metastatic breast cancer

PURPOSE

This phase III study compared docetaxel and doxorubicin in patients with metastatic breast cancer who had received previous alkylating agent-containing chemotherapy.

PATIENTS AND METHODS

Patients were randomized to receive an intravenous infusion of docetaxel 100 mg/m(2) or doxorubicin 75 mg/m(2) every 3 weeks for a maximum of seven treatment cycles.

RESULTS

A total of 326 patients were randomized, 165 to receive doxorubicin and 161 to receive docetaxel. Overall, docetaxel produced a significantly higher rate of objective response than did doxorubicin (47.8% v 33.3%; P =.008). Docetaxel was also significantly more active than doxorubicin in patients with negative prognostic factors, such as visceral metastases (objective response, 46% v 29%) and resistance to prior chemotherapy (47% v 25%). Median time to progression was longer in the docetaxel group (26 weeks v 21 weeks; difference not significant). Median overall survival was similar in the two groups (docetaxel, 15 months; doxorubicin, 14 months). There was one death due to infection in each group, and an additional four deaths due to cardiotoxicity in the doxorubicin group. Although neutropenia was similar in both groups, febrile neutropenia and severe infection occurred more frequently in the doxorubicin group. For severe nonhematologic toxicity, the incidences of cardiac toxicity, nausea, vomiting, and stomatitis were higher among patients receiving doxorubicin, whereas diarrhea, neuropathy, fluid retention, and skin and nail changes were higher among patients receiving docetaxel.

CONCLUSION

The observed differences in activity and toxicity profiles provide a basis for therapy choice and confirms the rationale for combination studies in early breast cancer.

Prospective randomized trial of docetaxel versus mitomycin plus vinblastine in patients with metastatic breast cancer progressing despite previous anthracycline-containing chemotherapy. 304 Study Group

PURPOSE

This phase III study compared docetaxel with mitomycin plus vinblastine (MV) in patients with metastatic breast cancer (MBC) progressing despite previous anthracycline-containing chemotherapy.

PATIENTS AND METHODS

Patients (n=392) were randomized to receive either docetaxel 100 mg/m2 intravenously (i.v.) every 3 weeks (n=203) or mitomycin 12 mg/m2 i.v. every 6 weeks plus vinblastine 6 mg/m2 i.v. every 3 weeks (n=189), for a maximum of 10 3-week cycles.

RESULTS

In an intention-to-treat analysis, docetaxel produced significantly higher response rates than MV overall (30.0% v 11.6%; P < .0001), as well as in patients with visceral involvement (30% v 11%), liver metastases (33% v 7%), or resistance to previous anthracycline agents (30% v 7%). Median time to progression (TTP) and overall survival were significantly longer with docetaxel than MV (19 v 1 weeks, P=.001, and 1 1.4 v 8.7 months, P=.0097, respectively). Neutropenia grade 3/4 was more frequent with docetaxel (93.1 % v62.5%; P < .05); thrombocytopenia grade 3/4 was more frequent with MV (12.0% v 4.1%; P < .05). Severe acute or chronic nonhematologic adverse events were infrequent in both groups. Withdrawal rates because of adverse events (MV, 10.1%; docetaxel, 13.8%) or toxic death (MV, 1.6%; docetaxel, 2.0%) were similar in both groups. Quality-of-life analysis was limited by a number of factors, but results were similar in both groups.

CONCLUSION

Docetaxel is significantly superior to MV in terms of response, TTP, and survival. The safety profiles of both therapies are manageable and tolerable. Docetaxel represents a clear treatment option for patients with MBC progressing despite previous anthracycline-containing chemotherapy.