HSA was a potent stimulator of estrone sulphatase activity and therefore contributes directly to the high estrogen concentrations found in breast cancer [44]. and Infiltrating ductal carcinoma (IDC) is the most common form of breast cancer that made up ~85% of all breast cancer cases [4]. Over these years, progress has been made on the study of molecular pathways, including the roles of hormones and receptors in cancer development and progression. However, the exact roles these molecules play in BAY 293 breast cancer growth remain inconclusive and poorly understood [5,6]. Therefore, identifying the differentially expressed proteins in breast cancer would be useful in understanding how the disease forms and advances. Identification of these proteins would also enable treatments that are specific to breast cancer to be formulated. Proteomics is a large-scale study of the proteome, which is the entire compliment of expression of proteins by a living organism [7]. Proteomics uses tools such as two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and liquid chromatography/mass spectrometry (LC/MS) [8] for protein separation and analysis, respectively. This approach has been used to identify protein biomarkers in breast cancers [913] and other types of cancer [1417]. Identification of protein biomarkers may have important prognostic values in the diagnosis and treatment of the disease [18,19]. The classification and prognosis of breast cancer are based on stage and grade of the tumour [20,21]. Both the information for grade and stage of the cancer are used to plan treatment for the patient. In this study, we aim to identify the differentially expressed aqueous soluble proteins between cancerous and normal IDC breast tissues and to relate the expression of these proteins to the grade and stage of IDC. We believe this information will contribute to the prognosis of IDC breast cancer. == 2. Methods == == 2.1. Breast Cancer Patients == Breast cancer patients were diagnosed with IDC and had undergone surgical treatment at Penang General Hospital, Penang, Malaysia. The patients were divided by stage and grade into 4 cohorts; Stages II, III and Grades II, III, respectively. Stage II, III cohorts contained 7 patients and 10 patients, respectively while Grade II and III cohorts contained 7 patients and 9 patients, respectively. Each sample set comprised cancerous and normal tissues from the same patient. The tissues were confirmed as cancerous and normal, respectively, by the hospital’s pathologist. The information on patients’ age, stage, TNM, grade, estrogen receptor, progesterone receptor, and C-ERB-B2oncoprotein status is listed inTable 1. == Table 1. == Patient information. == 2.2. Tissue Samples == Human ethical clearance from the Human Ethical Clearance Committee of Universiti Sains Malaysia and the Ministry of Health, Malaysia was received prior to conducting the study. Normal and cancerous breast tissues samples from IDC patients were Rabbit polyclonal to AML1.Core binding factor (CBF) is a heterodimeric transcription factor that binds to the core element of many enhancers and promoters. obtained from the Penang General Hospital, Penang, Malaysia. Informed consents BAY 293 from the breast cancer patients were received before the tissues were collected. The breast tissues were pathologically confirmed by the hospital’s pathologists. Breast carcinoma tumour tissues were taken from the ductal epithelium. Frozen section of tissue morphology was taken from the cancerous tissues from the anterior and deep region to ensure tumour adequacy and only the part of the cancerous tissue that had greater than 90% malignant cells was used in this study. Tissues were stored at 80C prior to analysis. == 2.3. Protein Extraction BAY 293 == Frozen tissues were thawed at room temperature (25C), rinsed with distilled water and homogenized on ice for 5 min. Proteins were extracted by addition of Tris buffer (TRIS) ((40 mM Tris, 1 mM 4-(2-Aminoethyl) benzenesulfonyl fluoride (AEBSF)) to the homogenized tissue. After centrifugation (13000 rpm, 20 min, 20C), the supernatant was collected and the protein concentration was determined in duplicates by RC-DC protein.