The extremely dismal prognosis of pancreatic cancer (PC) is attributed, at least in part, to lack of early diagnosis. confirmed the microarray results. In human PC cell lines, knockdown of CXCR7 resulted in decreased migration and invasion. Collectively, our data identified several promising markers and therapeutic targets of PC based on a comprehensive D609 screening and systemic validation. Introduction Pancreatic cancer (PC) is a human solid malignant tumor with very poor prognosis [1]. Several clinical and pathological factors for PC have been identified, including T stage, lymph node/distant metastasis, carbohydrate antigen (CA) 19-9 level and perineural/intraneural invasion; however, the factors affecting the prognosis of PC remain to be clarified [2], [3], [4], [5]. In addition, molecular events involved in the pathogenesis and progression of PC, such as Kras mutation, have been discovered as warm spots [1]. However, more research is required identify the cellular factors that affect prognosis. One of the major drawbacks of D609 the previous studies in human samples and cell lines is the difficulty to collect specimens in all stages of tumorigenesis. Therefore, animal models present unique advantages in this aspect. Chemical inducers of PC include N-nitrosobis(2-oxopropyl)amine, azaserine, and 7,12-dimethylbenzanthracene(DMBA) [6], [7], [8], [9], [10]. These models can induce the entire range of carcinogenesis, through advanced stage and metastasis. DMBA has been widely used in the establishment of rat PC models [11], [12], [13], [14], D609 [15], [16], [17]. In our previous studies, we found that acinar cells can transdifferentiate to ductal D609 cells in the D609 tumorigenesis process in the DMBA-induced PC rat model [18]. Nowadays, the notion and importance of acinar to ductal metaplasia (ADM) have been gradually accepted [19]. Previous studies have Rabbit polyclonal to ZMYND19 examined various features of these PC models, including histological/histochemical features [11], [12], [14], high-fat/high-protein diet as a promoter of carcinogenesis [13], glucose metabolism [15], and alterations in various proteins [16]. One recent investigation performed proteomic analysis in the PC rat model [17]. Thus far, the screening of differentially expressed genes in this model has not been reported. In the present study, our aim was to screen differentially expressed genes in PC using the DMBA-induced PC rat model. Materials and Methods Animals Adult Sprague-Dawley (SD) rats were provided by the Experimental Animal Center, Peking Union Medical College Hospital, Beijing, China. Rats were housed under standard conditions, including a pathogen-free environment and free access to food and drinking water. Twenty-four-hour urine samples were collected with metabolic cages in which only water but not food was provided. The Institutional Animal Care and Use Committee at Peking Union Medical College Hospital specifically approved this study and the use of rats. All efforts were made to minimize suffering. Establishment of DMBA-induced PC Model in Rats The DMBA-induced PC model was established in male SD rats according to our previous method [14]. A total of 75 rats were divided into experimental, control and sham groups. DMBA or NaCl crystals (5 mg) were used for rats in the experimental and control groups, respectively, whereas no agent was applied in the sham group. In experimental and control groups, rats were sacrificed at 7 days, 2 weeks, 1 month and 3 months after implantation. Five rats in the sham group were sacrificed at 1 month. Grouping of all the rats is shown in Table 1. Table 1 Numbers of rats in different groups. RNA Extraction and Microarray Analysis Total RNA was extracted from C80C frozen pancreatic tissue samples collected at all time points using the RNeasy mini kit (Qiagen, Germany) according to the manufacturers instructions. Total RNA sample concentration and purity were examined and estimated by optical density measurements at 260/280 nm using a NanoDrop Spectrophotometer and agarose gel electrophoresis. The detailed measurement data and quality evaluation is usually shown in Table 2. The SuperScript II reverse transcription kit (Invitrogen, USA), Genechip kit (Affymetrix, USA) and One-Cycle Target Labeling and Control Reagents (Affymetrix) were also used in the analyses. Hybridization was performed using the Genechip Rat Expression Set 230 (Affymetrix), according to the manufacturers instructions. Gene expression analyses were performed using the Affymetrix Rat Genome 230 A array (Affymetrix, Santa Clara, CA, USA). Sequences used in the design of the array.