Our data demonstrate that CaMKK-induced prostate cancer cell migration requires AMPK and, more specifically, the 1 catalytic kinase subunit of AMPK (Fig. to both increased AMPK phosphorylation and cell migration. Given the key roles of CaMKK and AMPK in the biology of prostate cancer cells, we propose that these enzymes are potential therapeutic targets in prostate cancer. Keywords:androgen receptor, prostate cancer, Ca2+/calmodulin-dependent protein kinase kinase , AMP-activated protein kinase, migration == A-438079 HCl Introduction == Prostate cancer is the most common Rabbit polyclonal to V5 malignancy in men and is second only to lung cancer in terms of cancer mortalities (1). If diagnosed early, most localized prostate tumors are successfully treated by surgery alone. However, as with many cancers, the treatment of the advanced disease state requires a systemic approach to inhibit the growth and spread of secondary metastases. Prostate cancers express the androgen receptor (AR) and rely on androgens for growth and survival (2). Subsequently, androgen ablation therapies are the standard of care for late-stage disease. While 80% of patients with prostate cancer respond favorably to initial androgen ablation therapy, most patients experience a relapse of the disease within 12 years (2). Despite the unresponsiveness of the hormone-refractory disease to androgen-deprivation therapy, AR-regulated signaling pathways remain active and are necessary for cancer progression (3). Consequently, A-438079 HCl AR and the processes downstream of the receptor remain viable targets for therapeutic intervention. Several approaches are currently used to target the AR signaling axis in prostate cancer. Current therapies focus on decreasing the levels of circulating androgens and/or competitively blocking the AR transcriptional complex. Specifically, gonadotropin-releasing hormone (GnRH) agonists are used to suppress the testicular production of testosterone whereas antiandrogens, such as bicalutamide, function by competitively inhibiting the interaction of androgens with AR. The initial response to either form of androgen deprivation is very high. However, the rapid onset of resistance to these interventions has highlighted the need for novel strategies to target the hormone-independent activities of AR. In this regard, our group and others have shown that the targeting of specific signaling pathways downstream of AR represents a potential new modality for the treatment of prostate cancer (47). Most of the studies on the role of androgens in prostate cancer have focused on defining the mechanisms underlying the mitotic actions of this hormone (8). However, there is a growing body of evidence that AR signaling also influences tumor cell migration and invasion. Of note, different clinical trials of goserelin (a GnRH analog) in prostate cancer patients demonstrate reduced incidences of distant metastases (9,10). Furthermore, it has recently been reported that A-438079 HCl MDV3100, a second generation AR-antagonist, decreases the number of circulating tumor cells in approximately half of the treated castration-resistant patients (11). Cumulatively, these data suggest that androgen ablation therapy not only inhibits the growth of the primary tumor, but also reduces progression to metastatic disease. The onus is now on researchers to identify what specific cellular processes regulated by AR contribute to the pathogenesis of prostate cancer and ultimately, whether they represent realistic therapeutic targets. To identify potential new points of intervention in AR-driven prostate cancer, we focused on candidate target proteins that are (a) expressed in the prostate, (b) regulated by AR, (c) track with disease outcome and (d) likely to be druggable. We also included in our criteria the requirement that the target be expressed in various cellular models of prostate cancer. Using these criteria, the Ca2+/calmodulin-dependent protein kinase kinase A-438079 HCl (CaMKK) was identified as a protein of interest. Subsequently, we performed a comprehensive analysis of its role in prostate A-438079 HCl cancer and demonstrate that CaMKK is likely to be a useful target for the treatment of this disease. == Materials and Methods == A description of the chemicals, antibodies, plasmids and stable cell lines used in this study can be found in theSupplementary Materials. == Cell culture and RNA == The LNCaP and VCaP human prostate carcinoma cell lines were obtained from ATCC and maintained as recommended. All experiments were performed with cells of passage less than 25. These cells were authenticated by morphological inspection and mycoplasma testing by the ATCC. Furthermore, their response to androgens was authenticated using growth and reporter gene assays. RNA from placenta, skeletal muscle, cerebellum, whole brain and normal prostate was from Clontech (Mountain View, CA). RNA from glioblastoma.