Combining Nanoliposomal Ceramide with Sorafenib Synergistically Inhibits Melanoma and Breast Cancer Cell Survival to Decrease Tumor Development

Department of Pharmacology-R130, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
Clinical Cancer Research (Impact Factor: 8.72). 06/2008; 14(11):3571-81. DOI: 10.1158/1078-0432.CCR-07-4881
Source: PubMed


Deregulation of phosphatidylinositol 3-kinase/Akt and Ras/Raf/mitogen-activated protein kinase/extracellular signal-regulated kinase kinase/extracellular signal-regulated kinase pathways occurs in melanoma and breast cancer, deregulating normal cellular apoptosis and proliferation. Therapeutic cocktails simultaneously targeting these pathways could promote synergistically acting tumor inhibition. However, agents with manageable toxicity and mechanistic basis for synergy need identification. The purpose of this study is to evaluate the preclinical therapeutic efficacy and associated toxicity of combining sorafenib with nanoliposomal ceramide.
Effects of sorafenib and nanoliposomal ceramide as single and combinatorial agents were examined on cultured cells using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt assays and CalcuSyn software used to assess synergistic or additive inhibition. Western blotting measured cooperative effects on signaling pathways. Rates of proliferation, apoptosis, and angiogenesis were measured in size- and time-matched tumors to identify mechanistic basis for inhibition. Toxicity was evaluated measuring animal weight, blood toxicity parameters, and changes in liver histology.
Sorafenib and nanoliposomal ceramide synergistically inhibited cultured cells by cooperatively targeting mitogen-activated protein kinase and phosphatidylinositol 3-kinase signaling. A 1- to 2-fold increase in cellular apoptosis and 3- to 4-fold decrease in cellular proliferation were observed following combination treatment compared with single agents, which caused synergistically acting inhibition. In vivo, an approximately 30% increase in tumor inhibition compared with sorafenib treatment alone and an approximately 58% reduction in tumor size compared with nanoliposomal ceramide monotherapy occurred by doubling apoptosis rates with negligible systemic toxicity.
This study shows that nanoliposomal ceramide enhances effectiveness of sorafenib causing synergistic inhibition. Thus, a foundation is established for clinical trials evaluating the efficacy of combining sorafenib with nanoliposomal ceramide for treatment of cancers.

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    • "Our laboratory has demonstrated that encapsulation of ceramide in a nanoliposome versus non-liposomal organic formulations results in an increase in cytotoxic potential with significant less toxicity [22]. Our laboratory has also demonstrated that the short chain C6-ceramide nanoliposomal formulation displays anti-proliferative effects in vitro, as well as results in tumor regression in several animal models of cancer [6,9,22,23]. "
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    ABSTRACT: Ceramide is a sphingolipid metabolite that induces cancer cell death. When C6-ceramide is encapsulated in a nanoliposome bilayer formulation, cell death is selectively induced in tumor models. However, the mechanism underlying this selectivity is unknown. As most tumors exhibit a preferential switch to glycolysis, as described in the "Warburg effect", we hypothesize that ceramide nanoliposomes selectively target this glycolytic pathway in cancer. We utilize chronic lymphocytic leukemia (CLL) as a cancer model, which has an increased dependency on glycolysis. In CLL cells, we demonstrate that C6-ceramide nanoliposomes, but not control nanoliposomes, induce caspase 3/7-independent necrotic cell death. Nanoliposomal ceramide inhibits both the RNA and protein expression of GAPDH, an enzyme in the glycolytic pathway, which is overexpressed in CLL. To confirm that ceramide targets GAPDH, we demonstrate that downregulation of GAPDH potentiates the decrease in ATP after ceramide treatment and exogenous pyruvate treatment as well as GAPDH overexpression partially rescues ceramide-induced necrosis. Finally, an in vivo murine model of CLL shows that nanoliposomal C6-ceramide treatment elicits tumor regression, concomitant with GAPDH downregulation. We conclude that selective inhibition of the glycolytic pathway in CLL cells with nanoliposomal C6-ceramide could potentially be an effective therapy for leukemia by targeting the Warburg effect.
    PLoS ONE 12/2013; 8(12):e84648. DOI:10.1371/journal.pone.0084648 · 3.23 Impact Factor
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    • "Khdair et al created a single multidrug nanoparticle with both chemotherapeutic and PDT agents that would target melanoma cells, in order to overcome acquired drug resistance.127 Tran et al used a nanoparticle with both sorafenib and ceramide to prevent acquired drug resistance.128 However, the mechanisms for acquired drug resistance in melanoma have been shown to be diverse. "
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    ABSTRACT: Melanoma is the most aggressive type of skin cancer and has very high rates of mortality. An early stage melanoma can be surgically removed, with a survival rate of 99%. However, metastasized melanoma is difficult to cure. The 5-year survival rates for patients with metastasized melanoma are still below 20%. Metastasized melanoma is currently treated by chemotherapy, targeted therapy, immunotherapy and radiotherapy. The outcome of most of the current therapies is far from optimistic. Although melanoma patients with a mutation in the oncogene v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) have an initially higher positive response rate to targeted therapy, the majority develop acquired drug resistance after 6 months of the therapy. To increase treatment efficacy, early diagnosis, more potent pharmacological agents, and more effective delivery systems are urgently needed. Nanotechnology has been extensively studied for melanoma treatment and diagnosis, to decrease drug resistance, increase therapeutic efficacy, and reduce side effects. In this review, we summarize the recent progress on the development of various nanoparticles for melanoma treatment and diagnosis. Several common nanoparticles, including liposome, polymersomes, dendrimers, carbon-based nanoparticles, and human albumin, have been used to deliver chemotherapeutic agents, and small interfering ribonucleic acids (siRNAs) against signaling molecules have also been tested for the treatment of melanoma. Indeed, several nanoparticle-delivered drugs have been approved by the US Food and Drug Administration and are currently in clinical trials. The application of nanoparticles could produce side effects, which will need to be reduced so that nanoparticle-delivered drugs can be safely applied in the clinical setting.
    International Journal of Nanomedicine 07/2013; 8(1):2677-88. DOI:10.2147/IJN.S45429 · 4.38 Impact Factor
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    • "The loss of PTEN results in constitutive activation of the PI3K/AKT pathway, which has been described in melanoma suggesting B-RAF inhibitors will only work for a subset of patients carrying the B-RAF V600E mutation and functional PTEN (VanBrocklin et al., 2009). Dual requirements for the PI3K/AKT pathway and constitutive MAPK signaling are also supported by combination treatments such as Sorafenib [small molecular inhibitor of several tyrosine protein kinases (VEGFR and PDGFR) and B-RAF] and nanoliposomal ceramide, which have been shown to synergistically decrease PI3K/AKT and MAPK signaling leading to increased sensitivity to the mitochondrial pathway of apoptosis in vitro (Tran et al., 2008). Furthermore, several MEK pathway inhibitors, such as UO126 and CI-1040, have also been shown to cause upregulation of pro-apoptotic BCL-2 protein function like BIM, BMF, Noxa, and PUMA, and occasionally can lead to the downregulation of anti-apoptotic proteins like BCL-2 and MCL-1 (Wang et al., 2007; VanBrocklin et al., 2009). "
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    ABSTRACT: The global incidence of melanoma has dramatically increased during the recent decades, yet the advancement of primary and adjuvant therapies has not kept a similar pace. The development of melanoma is often centered on cellular signaling that hyper-activates survival pathways, while inducing a concomitant blockade to cell death. Aberrations in cell death signaling not only promote tumor survival and enhanced metastatic potential, but also create resistance to anti-tumor strategies. Chemotherapeutic agents target melanoma tumor cells by inducing a form of cell death called apoptosis, which is governed by the BCL-2 family of proteins.The BCL-2 family is comprised of anti-apoptotic proteins (e.g., BCL-2, BCL-xL, and MCL-1) and pro-apoptotic proteins (e.g., BAK, BAX, and BIM), and their coordinated regulation and function are essential for optimal responses to chemotherapeutics. Here we will discuss what is currently known about the mechanisms of BCL-2 family function with a focus on the signaling pathways that maintain melanoma tumor cell survival. Importantly, we will critically evaluate the literature regarding how chemotherapeutic strategies directly impact on BCL-2 family function and offer several suggestions for future regimens to target melanoma and enhance patient survival.
    Frontiers in Oncology 10/2011; 1(34). DOI:10.3389/fonc.2011.00034
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