![]() ![]() Then, sections were incubated with Supervision ™ Universal goat anti-rabbit horseradish peroxidase-conjugated Detection reagent (catalog no. SC-5594 H-225 1:1,000 Santa Cruz Biotechnology, Inc., Dallas, TX, USA) overnight at 4☌. Following blocking, sections were incubated with anti-Notch4 polyclonal antibody (catalog no. Endogenous peroxidase activity was subsequently blocked by incubation with 3% H 2O 2 for 10 min at RT, and then blocked with 10% normal goat serum (OriGene Technologies, Inc., Rockville, MD, USA) in PBS (pH=7.4) for 30 min at RT. Antigen retrieval was achieved through microwaving in 0.01 mol/l citrate buffer (pH=6.0) for 15 min and then allowing cooling to room temperature (RT). Briefly, tissue sections were deparaffinized with xylene and rehydrated via incubation with gradient dilutions of ethanol. Immunohistochemical staining was performed using Envision's two-step method to assess Notch4 expression, as previously reported ( 21). Immunohistochemical stainingįormalin-fixed and paraffin-embedded breast cancer tissues were cut into 4-µm thick sections. Cases were then divided into three groups according to ER, PR and Her-2 expression: i) Triple-negative breast cancer: ER, PR and Her-2 were all negative (n=27) ii) Her-2-overexpressing breast cancer: ER- and PR-negative, Her-2-positive (n=24) iii) luminal breast cancer: ER- and/or PR-positive, Her-2-negative or -positive (n=47). Patients 10% of the cancer cell nuclei stained brown ( 19), and Her-2 was considered positive if >30% of the cancer cells presented with strong or complete cell membrane brown coloring ( 20). All patients received surgical treatment. All patients were female with a mean age of 50.5 years old (range, 36–81 years old). The study was approved by the Ethics Committee of Shantou University Medical College and written informed consent was obtained from all patients. Materials and methodsĪ total of 98 patients who were admitted to the Cancer Hospital of Shantou University Medical College (Shantou, China) between January 1996 and December 2008 were enrolled in the current study. Furthermore, the present study aimed to evaluate the potential of Notch4 as a prognostic marker for patients with breast cancer. In addition, the associations between Notch4 expression, and breast cancer clinicopathological characteristics and the prognosis of patients were analyzed. In the present study, different expression levels of Notch4 were investigated in different subtypes of breast cancer. Abnormal expression of Notch4 may inhibit the differentiation of mammary stem cells, and mutations of the Notch4 gene may enhance mammary epithelial cell proliferation, thus leading to the occurrence of breast cancer. These results demonstrated that the Notch4 signaling pathway serves an important role in the regulation of mammary gland growth and development. Notch4 has been identified to be expressed in stem cells of the mammary gland terminal duct, and has been implicated in the formation of branching structures that precede poorly differentiated adenocarcinoma, the restraining of TAC-2 cells to form duct branches, as well as growth factor β function, aggressive tumor phenotype, and the enabling of the transition from normal mouse mammary epithelial cells to heterotypic cells ( 12– 15). Of them, the role of Notch4 in epithelial tumors was identified by insertional mutagenesis in mice infected with mouse mammary tumor virus ( 12, 13). The Notch receptor family comprises four type I membrane proteins. In addition to classic prognostic factors, including tumor size, lymph nodes involved, and histological grade, some genetic and biological factors have been investigated to determine their effects on survival ( 9– 11). Patients with TNBC or Her-2-overexpressing subtypes exhibit the worst prognosis. In current clinical practice, immunohistochemical methods are used to test for estrogen receptor (ER), progesterone receptor (PR) and Her-2 expression due to the complexity, and high cost of performing molecular profiling ( 5– 8). In 2000, according to the cancer gene expression profiles, Sørlie et al ( 3) and Perou et al ( 4) divided breast cancer into luminal A, luminal B+C, human epidermal growth factor receptor 2 (Her-2)-overexpressing, basal-like and normal-like subtypes. ![]() Breast cancer is highly heterogeneous, and its biological behavior and response to therapy differ according to the subtype of breast cancer ( 1, 2).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |