title: Targeting HMG-CoA reductase with statins in a window-of-opportunity breast cancer trial.
abstract: Lipophilic statins purportedly exert anti-tumoral effects on breast cancer by decreasing proliferation and increasing apoptosis. HMG-CoA reductase (HMGCR), the rate-limiting enzyme of the mevalonate pathway, is the target of statins. However, data on statin-induced effects on HMGCR activity in cancer are limited. Thus, this pre-operative study investigated statin-induced effects on tumor proliferation and HMGCR expression while analyzing HMGCR as a predictive marker for statin response in breast cancer treatment. The study was designed as a window-of-opportunity trial and included 50 patients with primary invasive breast cancer. High-dose atorvastatin (i.e., 80 mg/day) was prescribed to patients for 2 weeks before surgery. Pre- and post-statin paired tumor samples were analyzed for Ki67 and HMGCR immunohistochemical expression. Changes in the Ki67 expression and HMGCR activity following statin treatment were the primary and secondary endpoints, respectively. Up-regulation of HMGCR following atorvastatin treatment was observed in 68 % of the paired samples with evaluable HMGCR expression (P = 0.0005). The average relative decrease in Ki67 expression following atorvastatin treatment was 7.6 % (P = 0.39) in all paired samples, whereas the corresponding decrease in Ki67 expression in tumors expressing HMGCR in the pre-treatment sample was 24 % (P = 0.02). Furthermore, post-treatment Ki67 expression was inversely correlated to post-treatment HMGCR expression (rs = -0.42; P = 0.03). Findings from this study suggest that HMGCR is targeted by statins in breast cancer cells in vivo, and that statins may have an anti-proliferative effect in HMGCR-positive tumors. Future studies are needed to evaluate HMGCR as a predictive marker for the selection of breast cancer patients who may benefit from statin treatment.
authors.affiliation: Department of Oncology, Skåne University Hospital, Clinical Sciences, Lund University, SE-221 85, Lund, Sweden.
authors.forename: Olöf
authors.initials: O
authors.lastname: Bjarnadottir
authors.forename: Quinci
authors.initials: Q
authors.lastname: Romero
authors.forename: Pär-Ola
authors.initials: PO
authors.lastname: Bendahl
authors.forename: Karin
authors.initials: K
authors.lastname: Jirström
authors.forename: Lisa
authors.initials: L
authors.lastname: Rydén
authors.forename: Niklas
authors.initials: N
authors.lastname: Loman
authors.forename: Mathias
authors.initials: M
authors.lastname: Uhlén
authors.forename: Henrik
authors.initials: H
authors.lastname: Johannesson
authors.forename: Carsten
authors.initials: C
authors.lastname: Rose
authors.forename: Dorthe
authors.initials: D
authors.lastname: Grabau
authors.forename: Signe
authors.initials: S
authors.lastname: Borgquist
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000069059:Atorvastatin; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D003131:Combined Modality Therapy; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006538:Heptanoic Acids / Q000627:therapeutic use*; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000235:genetics / Q000378:metabolism; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D019394:Ki-67 Antigen / Q000378:metabolism; D008875:Middle Aged; D011758:Pyrroles / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D019394:Ki-67 Antigen; D011758:Pyrroles; D000069059:Atorvastatin; D006903:Hydroxymethylglutaryl CoA Reductases