Hematopoietic Protection by Dexamethasone or Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) in Patients Treated With Carboplatin and Ifosfamide

Dexamethasone Increases Cisplatin-Loaded Nanocarrier Delivery and Efficacy in Metastatic Breast Cancer by Normalizing the Tumor Microenvironment

Dexamethasone is a glucocorticoid steroid with anti-inflammatory properties used to treat many diseases, including cancer, in which it helps manage various side effects of chemo-, radio-, and immunotherapies. Here, we investigate the tumor microenvironment (TME)-normalizing effects of dexamethasone in metastatic murine breast cancer (BC). Dexamethasone normalizes vessels and the extracellular matrix, thereby reducing interstitial fluid pressure, tissue stiffness, and solid stress. In turn, the penetration of 13 and 32 nm dextrans, which represent nanocarriers (NCs), is increased. A mechanistic model of fluid and macromolecule transport in tumors predicts that dexamethasone increases NC penetration by increasing interstitial hydraulic conductivity without significantly reducing the effective pore diameter of the vessel wall. Also, dexamethasone increases the tumor accumulation and efficacy of ∼30 nm polymeric micelles containing cisplatin (CDDP/m) against murine models of primary BC and spontaneous BC lung metastasis, which also feature a TME with abnormal mechanical properties. These results suggest that pretreatment with dexamethasone before NC administration could increase efficacy against primary tumors and metastases.

Trial Watch: Proteasomal inhibitors for anticancer therapy

The so-called "ubiquitin-proteasome system" (UPS) is a multicomponent molecular apparatus that catalyzes the covalent attachment of several copies of the small protein ubiquitin to other proteins that are generally (but not always) destined to proteasomal degradation. This enzymatic cascade is crucial for the maintenance of intracellular protein homeostasis (both in physiological conditions and in the course of adaptive stress responses), and regulates a wide array of signaling pathways. In line with this notion, defects in the UPS have been associated with aging as well as with several pathological conditions including cardiac, neurodegenerative, and neoplastic disorders. As transformed cells often experience a constant state of stress (as a result of the hyperactivation of oncogenic signaling pathways and/or adverse microenvironmental conditions), their survival and proliferation are highly dependent on the integrity of the UPS. This rationale has driven an intense wave of preclinical and clinical investigation culminating in 2003 with the approval of the proteasomal inhibitor bortezomib by the US Food and Drug Administration for use in multiple myeloma patients. Another proteasomal inhibitor, carfilzomib, is now licensed by international regulatory agencies for use in multiple myeloma patients, and the approved indications for bortezomib have been extended to mantle cell lymphoma. This said, the clinical activity of bortezomib and carfilzomib is often limited by off-target effects, innate/acquired resistance, and the absence of validated predictive biomarkers. Moreover, the antineoplastic activity of proteasome inhibitors against solid tumors is poor. In this Trial Watch we discuss the contribution of the UPS to oncogenesis and tumor progression and summarize the design and/or results of recent clinical studies evaluating the therapeutic profile of proteasome inhibitors in cancer patients.

Phase II randomized trial of carboplatin and gemcitabine with or without dexamethasone pre-treatment in patients with Stage IV non-small cell lung cancer

PURPOSE

Pre-clinical and early-phase clinical studies have demonstrated that dexamethasone (DEX) administration prior to chemotherapy reduces toxicity and enhances efficacy in the treatment of cancer. We undertook a randomized, phase II multi-institutional trial to evaluate these effects in patients with Stage IV non-small cell lung cancer.

METHODS

Patients were treated with carboplatin on day 1 and gemcitabine on days 1 and 8 every 21 days, for up to 6 cycles. Patients were randomized not to receive (Arm 1, n = 25) or to receive (Arm 2, n = 31) DEX orally for 4 days prior to chemotherapy on days 1 and 8. The primary endpoint was the incidence/course of grade 3 and 4 hematologic toxicity. Secondary endpoints included efficacy [response and overall survival (OS)] and evaluation of the Glasgow Prognostic Score (GPS), based on C-reactive protein and albumin levels, to predict survival and toxicity.

RESULTS

The incidence/course of grade 3 and 4 hematologic toxicity was significantly reduced in Arm 2 (DEX) versus Arm 1 (no DEX): neutrophils = 13 versus 40 % (p = 0.009) and platelets = 23 versus 44 % (p = 0.03). Response rates and OS were higher in Arm 2 versus Arm 1: 8/31 versus 2/25 (partial response, p = ns) and 378 versus 291 days (p = ns). The GPS significantly predicted survival OS (p = 0.04) but not toxicity.

CONCLUSIONS

Pre-treating patients with DEX is a safe, effective, and economic method of reducing the hematologic toxicity of carboplatin and gemcitabine. Our data suggest efficacy may also be enhanced by DEX pre-treatment.

Glucocorticoid receptor expression and antiproliferative effect of dexamethasone on human melanoma cells

Glucocorticoids, such as dexamethasone are widely used in cancer therapy and have cell type-specific pro- or antiapoptotic effects. We examined whether melanoma cells are sensitive to dexamethasone treatment. We have demonstrated for the first time that in human melanoma cell lines as well as in benign and malignant melanocytic tumors glucocorticoid receptor (GCR) is present both at mRNA and protein level. Dexamethasone applied at high doses inhibited the in vitro growth of WM983A human melanoma cells. The inhibitory effect was due to apoptosis induction. In the case of this relatively sensitive cell line dexamethasone enhanced the effect of the chemotherapeutic drug DTIC.

Evaluation of dexamethasone as a chemoprotectant for CCNU-induced bone marrow suppression in dogs

In mice and people, administering corticosteroids before chemotherapy can reduce the severity of myelosuppression without reducing antitumour effects. This study investigated whether pretreatment with dexamethasone would reduce the incidence of grade 4 neutropenia in dogs receiving CCNU. Twenty-five dogs received dexamethasone [0.1 mg kg(-1) per os (PO) every 12 h] for 5 days and on the sixth day received CCNU (90 mg m(-2) PO). Historical dogs (n = 67) received CCNU alone (90 mg m(-2) PO). Forty-five percent of historical dogs had grade 4 neutropenia, while 64% of dogs pretreated with dexamethasone had grade 4 neutropenia (P = 0.16). Dexamethasone plasma levels were quantified by enzyme-linked immunosorbent assay in three healthy dogs. Peak plasma concentrations after a single oral 0.1-mg kg(-1) dose were <80 ng mL(-1), the minimum level associated with chemoprotective effects of dexamethasone in people. Pretreatment with dexamethasone did not reduce the incidence of grade 4 neutropenia in dogs receiving CCNU.

Systematic review of the clinical effect of glucocorticoids on nonhematologic malignancy

BACKGROUND

Glucocorticoids are often used in the treatment of nonhematologic malignancy. This review summarizes the clinical evidence of the effect of glucocorticoid therapy on nonhematologic malignancy.

METHODS

A systematic review of clinical studies of glucocorticoid therapy in patients with nonhematologic malignancy was undertaken. Only studies having endpoints of tumor response or tumor control or survival were included. PubMed, EMBASE, the Cochrane Register/Databases, conference proceedings (ASCO, AACR, ASTRO/ASTR, ESMO, ECCO) and other resources were used. Data was extracted using a standard form. There was quality assessment of each study. There was a narrative synthesis of information, with presentation of results in tables. Where appropriate, meta-analyses were performed using data from published reports and a fixed effect model.

RESULTS

Fifty four randomized controlled trials (RCTs), one meta-analysis, four phase l/ll trials and four case series met the eligibility criteria. Clinical trials of glucocorticoid monotherapy in breast and prostate cancer showed modest response rates. In advanced breast cancer meta-analyses, the addition of glucocorticoids to either chemotherapy or other endocrine therapy resulted in increased response rate, but not increased survival. In GI cancer, there was one RCT each of glucocorticoids vs. supportive care and chemotherapy +/- glucocorticoids; glucocorticoid effect was neutral. The only RCT found of chemotherapy +/- glucocorticoids, in which the glucocorticoid arm did worse, was in lung cancer. In glucocorticoid monotherapy, meta-analysis found that continuous high dose glucocorticoids had a detrimental effect on survival. The only other evidence, for a detrimental effect of glucocorticoid monotherapy, was in one of the two trials in lung cancer.

CONCLUSION

Glucocorticoid monotherapy has some benefit in breast and prostate cancer. In advanced breast cancer, the addition of glucocorticoids to other therapy does not change the long term outcome. In GI cancer, glucocorticoids most likely have a neutral effect. High dose continuous glucocorticoids have a detrimental effect in nonhematologic malignancy. Glucocorticoid therapy might have a deleterious impact in lung cancer.

Nanoparticles containing anti-inflammatory agents as chemotherapy adjuvants: optimization and in vitro characterization

The pre-administration of dexamethasone (DEX) has previously been shown to enhance the anti-tumor efficacy of chemotherapeutic agents. The delivery of anti-inflammatory agents specifically to tumors via nanoparticle carriers is expected to promote the effectiveness of chemotherapeutic agents while avoiding systemic toxicities. The process for preparing solid lipid nanoparticles containing anti-inflammatory agents using the nanotemplate engineering method was optimized. Due to the solubilization of DEX in the bulk aqueous phase, its more lipophilic palmitate ester was synthesized and incorporated in nanoparticles that included a pegylating agent, PEG6000 mono-stearate, as part of the formulation. The stealth properties of these nanoparticles were demonstrated to be enhanced compared to latex particles by measuring the adsorption of radioiodinated IgG (185 microg vs. 6.7 microg IgG/mg NP). In addition, the uptake of (14)C-labeled nanoparticles by murine macrophages was shown to decrease from 36.6% to 14.7% of the nanoparticles/mg cell protein as the amount of pegylating agent in the formulation increased from 0 to 4 mg/mL. The high loading values and low burst effect observed for these DEX palmitate-containing nanoparticles in addition to their stealth properties are expected to allow for the delivery of sufficient amounts of DEX to tumors to enhance the uptake of chemotherapeutic agents.

Cancer relapse under chemotherapy: why TLR2/4 receptor agonists can help

Liver or lung metastases usually relapse under chemotherapy. Such life-threatening condition urgently needs new, systemic anticancer compounds, with original and efficient mechanisms of action. In B16 melanoma mice treated with cyclophosphamide, D'Agostini et al. [D'Agostini, C., Pica, F., Febbraro, G., Grelli, S., Chiavaroli, C., Garaci, E., 2005. Antitumour effect of OM-174 and Cyclophosphamide on murine B16 melanoma in different experimental conditions. Int. Immunopharmacol. 5, 1205-1212.] recently found that OM-174, a chemically defined Toll-like receptor(TLR)2/4 agonist, reduces tumor progression and prolongs survival. Here we review 149 articles concerning molecular mechanisms of TLR2/4 agonists, alone or in combination with chemotherapy. It appears that TLR2/4 agonists induce a well controlled tumor necrosis factor-alpha (TNF-alpha) secretion, at plasma levels known to permeabilize neoangiogenic tumor vessels to the passage of cytotoxic drugs. Moreover, TLR2/4 agonists induce inducible nitric oxide synthase (iNOS) expression, and nitric oxide is able to induce apoptosis of chemotherapy-resistant tumor cell clones. Finally, TLR2/4-stimulation activates dendritic cell traffic and its associated tumor-specific, cytotoxic T-cell responses. Therefore, parenteral TLR2/4 agonists seem promising molecules to prolong survival in cancer patients who relapse under chemotherapy.

Treating gliomas with glucocorticoids: from bedside to bench

Glucocorticoids are used in the treatment of gliomas to decrease tumour-associated oedema and to reduce the risk of acute encephalopathy associated with radiotherapy. However, the mechanisms by which glucocorticoids work are still largely unknown. In this paper, we survey the experimental and clinical evidence for the effects of glucocorticoids on tumour cell proliferation, apoptosis and sensitivity to chemotherapy, angiogenesis and vascular permeability. We then review current guidelines on the choice of molecule, dose and duration of glucocorticoid treatment for gliomas.

Glucocorticoid administration in antiemetic therapy: is it safe?

BACKGROUND

Although glucocorticoids are often used in cancer therapy, in particular to enhance the effectiveness of antiemetic therapy, they have been associated with impaired tumor apoptosis and an increased frequency of metastases in some reports. The current study aimed to determine whether glucocorticoid treatment had an adverse effect on outcomes in patients with ovarian carcinoma.

METHODS

Records of patients with ovarian carcinoma who were scheduled to receive at least six courses of systemic chemotherapy were reviewed. Patients were grouped into those who had or had not received corticosteroid medication as a part of general antiemetic prophylaxis before chemotherapy, and details of hematologic parameters during treatment and disease recurrence-free and overall survival were recorded.

RESULTS

Altogether, 245 patients with ovarian carcinoma had received chemotherapy. Of these, 62 had been given concurrent glucocorticoid treatment and 183 had not. The two patient groups were well balanced with respect to disease stage and other prognostic factors. Kaplan-Meier analyses showed no significant differences in survival between the groups. Patients who received glucocorticoid treatment had significantly higher leukocyte values in the days immediately after chemotherapy, higher nadir leukocyte values, and higher counts before subsequent courses of chemotherapy (P < 0.01; Levene test, t test) compared with patients who did not receive glucocorticoid treatment. As a result, the initial treatment targets were achieved significantly more often in the glucocorticoid group (P = 0.007; chi-square test).

CONCLUSIONS

There was no evidence that glucocorticoid treatment had a negative effect on outcomes in these patients. Glucocorticoids may exert protective effects on the bone marrow.

Pretreatment with Dexamethasone Increases Antitumor Activity of Carboplatin and Gemcitabine in Mice Bearing Human Cancer Xenografts

PURPOSE

The present study was undertaken to determine the effects of dexamethasone (DEX) pretreatment on antitumor activity and pharmacokinetics of the cancer chemotherapeutic agents carboplatin and gemcitabine.

EXPERIMENTAL DESIGN

Antitumor activities of carboplatin and gemcitabine with or without DEX pretreatment were determined in six murine-human cancer xenograft models, including cancers of colon (LS174T), lung (A549 and H1299), and breast (MCF-7 and MDA-MB-468) and glioma (U87-MG). Effects of DEX on plasma and tissue pharmacokinetics of carboplatin and gemcitabine were also determined by using the LS174T, A549, and H1299 models.

RESULTS

Although DEX alone showed minimal antitumor activity, DEX pretreatment significantly increased the efficacy of carboplatin, gemcitabine, or a combination of both drugs by 2-4-fold in all xenograft models tested. Without DEX treatment, the tumor exposure to carboplatin, measured by the area under the curve, was markedly lower than normal tissues. However, DEX pretreatment significantly increased tumor carboplatin levels, including 200% increase in area under the curve, 100% increase in maximum concentration, and 160% decrease in clearance. DEX pretreatment similarly increased gemcitabine uptake in tumors.

CONCLUSIONS

To our knowledge, this is the first report that DEX significantly enhances the antitumor activity of carboplatin and gemcitabine and increases their accumulation in tumors. These results provide a basis for further evaluation of DEX as a chemosensitizer in patients.