AIM: To reveal the expression of multidrug-resistance associated proteins: glutathione-S-transferase π(GSTπ), P-glycoprotein(P-gp) and vault protein lung resistance protein(LRP) in retinoblastoma(RB) without any conservative treatment before primary enucleation and to correlate this expression with histopathological tumor features. METHODS: A total of 42 specimens of RB undergone primary enucleation were selected for the research. Sections from the formalin-fixed, paraffin-embedded specimens were stained with HE and immunohistochemistry to detect the expression of GSTπ, P-gp and LRP.RESULTS: GSTπ was expressed in 39/42(92.86%) RBs and in 9/9(100%) well-differentiated RBs. P-gp/GSTπ was found in 30(71.42%) of 42 RBs. Totally 9(21.43%) tumors were well differentiated and 33(78.57%) were poorly differentiated. Totally 15(35.71%) eyes had optic nerve(ON) tumor invasion, 36(85.71%) had choroidal tumor invasion, and 14(33.33%) had simultaneous choroidal and ON invasion. There was no statistically significant relationship between P-gp, GSTπ, LRP positivity and the degree of ocular layer tumor invasion and ON tumor invasion(P>0.05). CONCLUSION: RB intrinsically expresses GSTπ, P-gp and LRP. GSTπ expression is positive in 100% welldifferentiation ones, so in which way it is correlated with differentiation. But the other two proteins expressions are not related to tumor differentiation and to the degree of tumor invasion. GSTπ may be a new target of chemotherapy in RB.
AIM: To investigate C-myc, Ki-67, pan-cytokeratin, and vimentin immunohistochemical features of carcinoma ex pleomorphic adenoma(Ca-ex-PA) and pleomorphic adenoma(PA) in the lacrimal gland in order to find some clues in the differential diagnosis between them.METHODS: We reviewed microscopic slides and clinical records of 64 cases of PA and 15 cases of Ca-ex-PA in the lacrimal gland. Immunohistochemical antibodies for C-myc, Ki-67, pan-cytokeratin, and vimentin were employed.RESULTS: Median age of PA was 43.2 y(from 21 to 75). The 35 patients(54.7%) were male and 29 patients(45.3%) were female. For the PAs, the average positivity of C-myc was 4.6%;the average proliferation index of Ki-67 was 3.2%;pan-cytokeratin was positive in ductal cells, and vimentin was positive in myoepithelial cells. Median age of Ca-ex-PA was 54.3 y(from 26 to 76). There were 7 male patients(46.7%) and 8 female patients(53.3%). Among 15 Ca-ex-PAs, there were 6 myoepithelial carcinomas, 4 adenocarcinomas, 3 epithelial-myoepithelial carcinomas, and 2 squamous cell carcinomas. For the Ca-ex-PAs, the average positivity of C-myc was 36.4%;the average proliferation index of Ki-67 was 29.2%;pan-cytokeratin was positive in all cases, and vimentin was positive in myoepithelial carcinomas.CONCLUSION: PA has a lower positivity of C-myc and Ki-67, while Ca-ex-PA had a higher positivity of these two biomarkers. These four biomarkers as a set could provide valuable clues in the differential diagnosis between Ca-exPA and PA. Our results indicate that the activation of C-myc could play an important role in the pathogenesis of Ca-exPA and PA.
Ping ZhangLi-Juan TangHuan-Huan GaoWen-Xin ZhangJian-Xian LinHua-Sheng Yang
