Cyclin A2 and CDK2 as Novel Targets of Aspirin and Salicylic Acid: A Potential Role in Cancer Prevention

Abstract

Data emerging from the past 10 years have consolidated the rationale for investigating the use of aspirin as a chemopreventive agent; however, the mechanisms leading to its anti-cancer effects are still being elucidated. We hypothesized that aspirin’s chemopreventive actions may involve cell cycle regulation through modulation of the levels or activity of cyclin A2/cyclin dependent kinase-2 (CDK2). In this study, HT-29 and other diverse panel of cancer cells were used to demonstrate that both aspirin and its primary metabolite, salicylic acid, decreased cyclin A2 (CCNA2) and CDK2 protein and mRNA levels. The down regulatory effect of either drugs on cyclin A2 levels was prevented by pretreatment with lactacystin, an inhibitor of proteasomes, suggesting the involvement of 26S proteasomes. In-vitro kinase assays showed that lysates from cells treated with salicylic acid had lower levels of CDK2 activity. Importantly, three independent experiments revealed that salicylic acid directly binds to CDK2. Firstly, inclusion of salicylic acid in naïve cell lysates, or in recombinant CDK2 preparations, increased the ability of the anti-CDK2 antibody to immunoprecipitate CDK2, suggesting that salicylic acid may directly bind and alter its conformation. Secondly, in 8-anilino-1-naphthalene-sulfonate (ANS)-CDK2 fluorescence assays, pre-incubation of CDK2 with salicylic acid, dose-dependently quenched the fluorescence due to ANS. Thirdly, computational analysis using molecular docking studies identified Asp145 and Lys33 as the potential sites of salicylic acid interactions with CDK2. These results demonstrate that aspirin and salicylic acid down-regulate cyclin A2/CDK2 proteins in multiple cancer cell lines, suggesting a novel target and mechanism of action in chemoprevention. Implications Biochemical and structural studies indicate that the anti-proliferative actions of aspirin are mediated through cyclin A2/CDK2.

Identification of Key Genes Related to Lung Squamous Cell Carcinoma Using Bioinformatics Analysis

“…Although reported that abnormal expression levels were found in multiple types of human malignancy and have potential as anticancer therapeutic targets [35][36][37][38][39][40].…”

Aspirin increases metabolism through germline signalling to extend the lifespan of Caenorhabditis elegans

“…Similar results showed that aspirin could acetylate and inhibit glucose-6-phosphate dehydrogenase (G6PD), which catalyses the first reaction in the pentose phosphate pathway and is important for the regulation of oxidative stress [ 36 ]. For the mechanism of action in anti-cancer and chemoprevention activities, aspirin and salicylic acid can directly bind to CDK2 and down-regulate cyclin A2/CDK2 proteins [ 37 ] and inhibit CBP and p300 lysine acetyltransferase activity in vitro through direct competition with acetyl-Coenzyme A at the catalytic site [ 38 ]. These results revealed that the targets of aspirin and its metabolite are associated with metabolic function or immunity and are therefore involved in aging modulation.…”

Compound C enhances the anticancer effect of aspirin in HER-2-positive breast cancer by regulating lipid metabolism in an AMPK-independent pathway

“…Moreover, aspirin may also indirectly activate AMPK through other processes [14]. It has been reported that aspirin and its metabolites regulate cyclin-dependent kinase (CDK) [15,16] and Wnt/β-catenin signaling [17,18].…”