Knoxx, J. J. et al. A Phase I trial of prolonged administration of lovastatin in patients with recurrent or metastatic squamous cell carcinoma of the head and neck or of the cervix. Eur. J. Cancer 41, 523-530
Departments of Medical Oncology, Princess Margaret Hospital, Ontario Cancer Institute, University Health Network, 5-218, 610 University Avenue, Toronto, Ont., Canada M5G 2M9. European Journal of Cancer
(Impact Factor: 5.42).
04/2005; 41(4):523-30. DOI: 10.1016/j.ejca.2004.12.013
Squamous cell carcinomas of the head and neck (HNSCC) and of the cervix (CC) are particularly sensitive to the apoptotic effects of lovastatin in vitro. In this Phase I study, the safety and maximum related dose (MTD) of lovastatin was evaluated in these specific clinical settings. This was a Phase I open-label study to determine the recommended Phase II dose (RPTD) of lovastatin in advanced HNSCC or CC. This study involved a dose and duration escalation of lovastatin starting at 5/mg/kg/day x 2 weeks, every 21 days, until the MTD was reached. Plasma samples were collected for pharmacokinetic analysis. All 26 patients enrolled were evaluable. Dose-limiting toxicity (DLT) consisting of reversible muscle toxicity was seen at 10 mg/kg/day x 14 days. Toxicity may be related to relative renal insufficiency. The MTD was determined to be 7.5 mg/kg/day x 21 days, every 28 days. The low lipid levels experienced on study did not translate into adverse events. Biologically relevant plasma lovastatin levels were obtained. No objective responses were seen but the median survival of patients on study was 7.5 months (mean 9.2 +/- 1.5 months). Stable disease (SD) for more than 3 months was seen in 23% of patients. One patient achieved SD and clinical benefit for 14 months on study and a further 23 months off treatment. The disease stabilisation rate of 23% seen in these end-stage patients is encouraging. We conclude that the administration of lovastatin at 7.5 mg/kg/day for 21 consecutive days on a 28-day schedule is well tolerated in patients with good renal function and warrants further clinical evaluation.
Available from: Jim Dimitroulakos
- "Through inhibition of mevalonate synthesis, statin treatment has the potential for plieotropic cellular effects through the targeting of a wide variety of cell signaling proteins , , . We have previously shown that lovastatin can induce tumour specific apoptosis especially in squamous cell carcinomas (SCC)  and that 23% of SCC patients treated with lovastatin as a single agent showed disease stabilization in our Phase I clinical trial . To enhance efficacy, understanding the mechanism of lovastatin-induced apoptosis may uncover novel therapeutic strategies. "
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ABSTRACT: Cellular stress responses trigger signaling cascades that inhibit proliferation and protein translation to help alleviate the stress or if the stress cannot be overcome induce apoptosis. In recent studies, we demonstrated the ability of lovastatin, an inhibitor of mevalonate synthesis, to induce the Integrated Stress Response as well as inhibiting epidermal growth factor receptor (EGFR) activation.
In this study, we evaluated the effects of lovastatin on the activity of the LKB1/AMPK pathway that is activated upon cellular energy shortage and can interact with the above pathways. In the squamous cell carcinoma (SCC) cell lines SCC9 and SCC25, lovastatin treatment (1-25 µM, 24 hrs) induced LKB1 and AMPK activation similar to metformin (1-10 mM, 24 hrs), a known inducer of this pathway. Lovastatin treatment impaired mitochondrial function and also decreased cellular ADP/ATP ratios, common triggers of LKB1/AMPK activation. The cytotoxic effects of lovastatin were attenuated in LKB1 null MEFs indicating a role for this pathway in regulating lovastatin-induced cytotoxicity. Of clinical relevance, lovastatin induces synergistic cytotoxicity in combination with the EGFR inhibitor gefitinib. In LKB1 deficient (A549, HeLa) and expressing (SCC9, SCC25) cell lines, metformin enhanced gefitinib cytotoxicity only in LKB1 expressing cell lines while both groups showed synergistic cytotoxic effects with lovastatin treatments. Furthermore, the combination of lovastatin with gefitinib induced a potent apoptotic response without significant induction of autophagy that is often induced during metabolic stress inhibiting cell death.
Thus, targeting multiple metabolic stress pathways including the LKB1/AMPK pathway enhances lovastatin's ability to synergize with gefitinib in SCC cells.
Available from: Jim Dimitroulakos
- "As a result, a Phase I clinical evaluation of lovastatin in recurrent head and neck squamous cell carcinomas and cervical carcinoma patients was undertaken by our group. Although no tumor regressions were observed, 23% of patients exhibited stable disease . Taken together, the most effective use of lovastatin and VEGFR-TKI would be as part of a combined modality approach. "
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ABSTRACT: In a recent study, we demonstrated the ability of lovastatin, a potent inhibitor of mevalonate synthesis, to inhibit the function of the epidermal growth factor receptor (EGFR). Lovastatin attenuated ligand-induced receptor activation and downstream signaling through the PI3K/AKT pathway. Combining lovastatin with gefitinib, a potent EGFR inhibitor, induced synergistic cytotoxicity in a variety of tumor derived cell lines. The vascular endothelial growth factor receptor (VEGFR) and EGFR share similar activation, internalization and downstream signaling characteristics.
The VEGFRs, particularly VEGFR-2 (KDR, Flt-1), play important roles in regulating tumor angiogenesis by promoting endothelial cell proliferation, survival and migration. Certain tumors, such as malignant mesothelioma (MM), also express both the VEGF ligand and VEGFRs that act in an autocrine loop to directly stimulate tumor cell growth and survival. In this study, we have shown that lovastatin inhibits ligand-induced VEGFR-2 activation through inhibition of receptor internalization and also inhibits VEGF activation of AKT in human umbilical vein endothelial cells (HUVEC) and H28 MM cells employing immunofluorescence and Western blotting. Combinations of lovastatin and a VEGFR-2 inhibitor showed more robust AKT inhibition than either agent alone in the H28 MM cell line. Furthermore, combining 5 µM lovastatin treatment, a therapeutically relevant dose, with two different VEGFR-2 inhibitors in HUVEC and the H28 and H2052 mesothelioma derived cell lines demonstrated synergistic cytotoxicity as demonstrated by MTT cell viability and flow cytometric analyses.
These results highlight a novel mechanism by which lovastatin can regulate VEGFR-2 function and a potential therapeutic approach for MM through combining statins with VEGFR-2 inhibitors.
Available from: PubMed Central
- "More recently statins have been evaluated on cohorts of patients harboring a tumor-type that has been shown to be sensitive to statin-induced apoptosis in tissue culture studies. In these focused, tumor-specific, hypothesis-driven trials, statins have demonstrated some efficacy as a single agent[29,30,37] but more wide-reaching effects were evident when statins were combined with chemotherapeutics [10,11,38,39]. Thus, our data identifying ovarian carcinoma as a statin-sensitive tumor type strongly supports the evaluation of statins in strategies to combat this disease. "
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ABSTRACT: Ovarian carcinoma is a rarely curable disease, for which new treatment options are required. As agents that block HMG-CoA reductase and the mevalonate pathway, the statin family of drugs are used in the treatment of hypercholesterolemia and have been shown to trigger apoptosis in a tumor-specific manner. Recent clinical trials show that the addition of statins to traditional chemotherapeutic strategies can increase efficacy of targeting statin-sensitive tumors. Our goal was to assess statin-induced apoptosis of ovarian cancer cells, either alone or in combination with chemotherapeutics, and then determine these mechanisms of action.
The effect of lovastatin on ovarian cancer cell lines was evaluated alone and in combination with cisplatin and doxorubicin using several assays (MTT, TUNEL, fixed PI, PARP cleavage) and synergy determined by evaluating the combination index. The mechanisms of action were evaluated using functional, molecular, and pharmacologic approaches.
We demonstrate that lovastatin induces apoptosis of ovarian cancer cells in a p53-independent manner and synergizes with doxorubicin, a chemotherapeutic agent used to treat recurrent cases of ovarian cancer. Lovastatin drives ovarian tumor cell death by two mechanisms: first, by blocking HMG-CoA reductase activity, and second, by sensitizing multi-drug resistant cells to doxorubicin by a novel mevalonate-independent mechanism. This inhibition of drug transport, likely through inhibition of P-glycoprotein, potentiates both DNA damage and tumor cell apoptosis.
The results of this research provide pre-clinical data to warrant further evaluation of statins as potential anti-cancer agents to treat ovarian carcinoma. Many statins are inexpensive, off-patent generic drugs that are immediately available for use as anti-cancer agents. We provide evidence that lovastatin triggers apoptosis of ovarian cancer cells as a single agent by a mevalonate-dependent mechanism. Moreover, we also show lovastatin synergizes with doxorubicin, an agent administered for recurrent disease. This synergy occurs by a novel mevalonate-independent mechanism that antagonizes drug resistance, likely by inhibiting P-glycoprotein. These data raise important issues that may impact how statins can best be included in chemotherapy regimens.
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