Expressions Of MMP-2 And TIMP-1 In Human Retinoblastoma

ObjectiveMMPs is a kind of proteinase which contains Zn2+. The main function of the proteinases is that they can degrade compounds of the extracellular matrix. These proteinases play a pivotal role in tissue' s physiological functions and pathological destructions. Their roles in tumor growth and invasion have been described. Our study aims to explore the expressions of the MMP - 2 and TIMP - 1 in human retinoblastoma.Methods31 paraffin wax embedding RB as well as 8 normal retinal samples were enrolled in our study. Rabbit and - MMP2 and anti - TIMP1 monoclonal antibody were the reagents and the density was 1:50. The samples were serially cut into five 5um slides by microtome and one of them was examined on light - microscope. Referring to document, the samples was grouped into differentiated ( containing Flexner - Winter-steiner rosettes) and poor - differentiated groups( containing no Flexner - Wintersteiner rosettes) as well as optic nerve infiltrated and un-infiltrated groups. Normal immunohistochemical staining was undertaken. Breast cancer specimen was used as positive comparison and PBS was used as negative comparison as the substitute of secondary antibody. The positive stains were yellow or brown signals. MMP - 2 and TIMP -1 are all located in tumor cell and a few interstitial cell 'scytoplasms. The label indexs were evaluated at five randomly chosen microscopic fields of 400 x by counting at least 1000 tumor cell' s. The results were calculated according to the rate of positive cells number to total number. SPSS10. 0 software was used for independent -sample t test and correlation analysis. The probability was considered as 0.05.Results1. Nomal retinal sampleThere were no stains in normal retinal samples.2. Characteristics of RB samples by HE staining in light microscope31 RB samples come from patients aging 2-53 months and average year is 13. Smonths. Differentiated groupe has 7 cases. The cell is small, round or polygonal with darkly staining nuclei. Cracked nuclei can be found in cytoplasma. Characteristic Jlexner - Wintersteiner rosettes can ofen be found. 24 cases are in poor ?diffentiated group. The cell is small, round or polygonal, having scanty cytoplasm and darkly staining nuclei. The nuclear split can often be found and cell * s arrangement is unregular.3. Expressions of MMP - 2 and TIMP - 1 in normal retinal and retinoblastoma The expressions of MMP - 2 and TIMP -1 in poor - differentiated group are significantly higher than differentiated group ( p < 0. 05). The expressions of MMP - 2 and TIMP -1 in optic - nerve infiltrated group are also significantly higher than those of the optic -nerve uninfiltrated group ( p < 0.05 ). The expression of MMP -2 has positively relation with TIMP -1(r=0.52).DiscussionIn the research of retinoblastoma, the " 2 - hit theory" and " tumor suppression gene theory" are the most popular theories. The " tumor suppression gene theory" refers that the loss of tumor suppression gene' s activation is the main reason of tumor. Generally speaking, it refers to the loss of 13ql4 ". The " two - hit theory" maintains that a normal cell can' t turn into a tumor cell unless it experienced two mutations. The hereditary cases is inherited the first mutation from their parents and when they are born, their body cells have a mutation. Then the retinal cell can turn into tumor cells with only one mutation . The sporadic cases must have two mutations in their retinal cells to become tumor cells.It has been found that the metalloproteinases involves many physiologic and pathologic processes. At the same dme, metalloproteinases and their inhibitors - tissue inhibitors of matrix metalloproteinases' functions in tumor have been noticed by researchers. It has been documented that they are involved in tumor cell' s infiltration. Their expressions have some relationships with tumor cell ' growth and malig-nance. In human retinoblastoma, the breakthrough of retinal extracellular matrix and the hyaloid membrane is necessary f...