Browsing by Subject "Antitumor activity"

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    Non-Coding Micro RNAs and Hypoxia-Inducible Factors Are Selenium Targets for Development of a Mechanism-Based Combination Strategy in Clear-Cell Renal Cell Carcinoma—Bench-to-Bedside Therapy
    (MDPI, 2018-10-29) Rustum, Youcef M.; Chintala, Sreenivasulu; Durrani, Farukh A.; Bhattacharya, Arup; Neurological Surgery, School of Medicine
    Durable response, inherent or acquired resistance, and dose-limiting toxicities continue to represent major barriers in the treatment of patients with advanced clear-cell renal cell carcinoma (ccRCC). The majority of ccRCC tumors are characterized by the loss of Von Hippel⁻Lindau tumor suppressor gene function, a stable expression of hypoxia-inducible factors 1α and 2α (HIFs), an altered expression of tumor-specific oncogenic microRNAs (miRNAs), a clear cytoplasm with dense lipid content, and overexpression of thymidine phosphorylase. The aim of this manuscript was to confirm that the downregulation of specific drug-resistant biomarkers deregulated in tumor cells by a defined dose and schedule of methylselenocysteine (MSC) or seleno-l-methionine (SLM) sensitizes tumor cells to mechanism-based drug combination. The inhibition of HIFs by selenium was necessary for optimal therapeutic benefit. Durable responses were achieved only when MSC was combined with sunitinib (a vascular endothelial growth factor receptor (VEGFR)-targeted biologic), topotecan (a topoisomerase 1 poison and HIF synthesis inhibitor), and S-1 (a 5-fluorouracil prodrug). The documented synergy was selenium dose- and schedule-dependent and associated with enhanced prolyl hydroxylase-dependent HIF degradation, stabilization of tumor vasculature, downregulation of 28 oncogenic miRNAs, as well as the upregulation of 12 tumor suppressor miRNAs. The preclinical results generated provided the rationale for the development of phase 1/2 clinical trials of SLM in sequential combination with axitinib in ccRCC patients refractory to standard therapies.
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    Superior Therapeutic Efficacy of Nanoparticle Albumin Bound Paclitaxel Over Cremophor-Bound Paclitaxel in Experimental Esophageal Adenocarcinoma
    (Elsevier, 2018-04) Hassan, Md Sazzad; Awasthi, Niranjan; Li, Jun; Williams, Fiona; Schwarz, Margaret A.; Schwarz, Roderich E.; von Holzen, Urs; Surgery, School of Medicine
    Esophageal adenocarcinoma (EAC) is the fastest growing cancer in the western world and the overall 5 year survival rate of EAC is below 20%. Most patients with EAC present with locally advanced or widespread metastatic disease, where current treatment is largely ineffective. Therefore, new therapeutic approaches are urgently needed. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is a novel albumin-stabilized, cremophor-free and water soluble nanoparticle formulation of paclitaxel, and the potential role of nab-paclitaxel has not been tested yet in experimental EAC. Here we tested the antiproliferative and antitumor efficacy with survival advantage of nab-paclitaxel as monotherapy and in combinations in in-vitro, and in murine subcutaneous xenograft and peritoneal metastatic survival models of human EAC. Nab-paclitaxel significantly inhibited in-vitro cell proliferation with higher in-vivo antitumour efficacy and survival benefit compared to paclitaxel or carboplatin treatments both in mono- and combination therapies. Nab-paclitaxel treatment increased expression of mitotic-spindle associated phospho-stathmin, decreased expression of proliferative markers and enhanced apoptosis. This study demonstrates that nab-paclitaxel had stronger antiproliferative and antitumor activity in experimental EAC than the current standard chemotherapeutic agents which supports the rationale for its clinical use in EAC.