Notably, these studies enrolled unselected patients with respect to EGFR status. EGFR (EGFRlow). Microarray analysis did not reveal any differences in gene expression between EGFRhigh and EGFRlow tumours. Conversely, in EGFRhigh tumours, we were able to identify a 79 gene signature distinguishing mutated from non-mutated tumours. Additionally, 29 genes were found to be differentially expressed between mutated/EGFRhigh (n=3) and mutated/EGFRlow tumours (n=5). Four of the down-regulated genes, U19/EAF2, ABCC4, KLK3 and ANXA3 and one of the up-regulated genes, FOXC1, are involved in PC progression. Conclusions Based on our findings, we hypothesize that accurate definition of the EGFR status could improve prognostic stratification and we suggest a possible role for EGFR-directed therapies in PC patients. Having been generated in a relatively small Ligustilide sample of patients, our results warrant confirmation in larger series. Background Prostate cancer (PC) is among the most frequently diagnosed Ligustilide solid tumours in men, and the metastatic forms still represent the second leading Ligustilide cause of cancer-related death [1,2]. Treatment of PC by radical prostatectomy, radiotherapy and anti-androgen therapy results in long term survival in patients with localized and androgen-dependent PC. By contrast, hormone-refractory prostate cancer (HRPC) forms are associated with disease relapse and poor patient survival [3,4]. At present, increasing serum prostate-specific antigen (PSA) levels following treatment of primary PC is used to identify PC biochemical relapse, a condition that anticipates clinically detectable tumour progression. The identification of novel biomarkers that predict the risk of relapse or that could be used as therapeutic targets is needed. The molecular mechanisms responsible for PC development, hormone-independence and development aren’t crystal clear however. Several results suggest that modifications of different pathways regarding growth aspect receptors are likely involved within this multistep procedure [5,6]. Specifically, the Epidermal Development Aspect Receptor (EGFR) is generally overexpressed in Computer and this is normally associated with a RGS10 far more intense clinical final result. Ligustilide EGFR overexpression in addition has been from the changeover from androgen-responsiveness towards the androgen-independent/hormone-refractory phenotype [7,8]. Furthermore, preclinical data possess suggested which the EGFR signalling pathway can activate the androgen receptor under circumstances of scientific androgen deprivation [9]. EGFR provides assumed significant importance hence, because of overexpression in various tumour types also to its function as a medication target. A number of anti-EGFR medications are Meals and Medication Administration-approved or under evaluation in clinical trials currently. These medications consist of little inhibitory substances such as for example erlotinib or gefitinib, aswell simply because antibodies such as for example panitumumab and cetuximab. Gefitinib can be an dental anilinoquinazolone substance that blocks the EGFR tyrosine kinase (TK) activity [10] leading to the inhibition of downstream signalling pathways. Clinical proof, mainly deriving from non little cell lung cancers (NSCLC) patients, showed that activating mutations in the EGFR TK domains (exons from 18 to 21) anticipate response to gefitinib [11]. A recently available study discovered 4 book missense mutations in exons 19, 20 and 21 from the EGFR TK domains in Caucasian and Korean Computer sufferers. Three of these, G735S, E804G and G796S, resulted in an oncogenic Ligustilide activation marketing cell invasion and proliferation [12]. Preclinical studies show activity of gefitinib against PC cell xenografts and lines [13]. In a stage I scientific trial, 252 sufferers with different solid tumours, including 28 sufferers with HRPC, received dental gefitinib [14]. One affected individual with HRPC acquired a measurable reduced amount of disease within a lymph node metastasis, palliation of disease-related discomfort, and a decrease in PSA [15]. In another randomized stage II scientific trial 82 HRPC sufferers had been treated with prednisone plus gefitinib or prednisone plus placebo [16]. This scholarly study showed limited antitumour activity of gefitinib in HRPC patients. However, patients weren’t selected based on EGFR position. At the moment, no scientific data can be found.