Expression of SATB1, MTI/II and Ki-67 in Mycosis Fungoides

Background/Aim: A genome organizer protein, special AT-rich sequence binding protein 1, (SATB1), was recently shown to play an important role in the development and spread of various malignancies. Metallothioneins I and II (MTI/II) are multifunctional proteins involved, among others, in cell proliferation and apoptosis resistance in tumors. The role and relevance of these factors in mycosis fungoides (MF), the most common primary cutaneous T-cell lymphoma, is not fully understood. The aim of the present analysis was to evaluate the expression and potential correlation of SATB1, MTI/II and Ki-67 with clinicopathological data in MF. Materials and Methods: We performed immunohistochemical analysis for SATB1, MTI/II and Ki-67 on 90 cases of MF and 19 controls (chronic benign dermatoses). The expression of SATB1 and Ki-67 was analyzed in cancer cell nuclei, whereas nuclear and cytoplasmic expressions of MTI/II were scored separately (nMT, cMT; respectively). Results: We recorded a significantly higher expression of SATB1 and cMT in MF compared to the control group (p<0.002, p=0.04, respectively, Student's t-test). We also noted significant differences in the mean (+/- SD) expression of nMT and cMT in advanced MF compared to early MF, (1.4 +/- 1.3 vs. 0.9 +/- 0.9, 4.1 +/- 3.8 vs. 2.5 +/- 2.9, respectively; p=0.04 for both). Similarly, Ki-67 expression was significantly higher in advanced MF (p<0.01). The expression of SATB1, cMT and Ki-67 was significantly higher in more infiltrating skin lesions (p<0.001, p=0.08 and p<0.001, respectively). Regarding extracutaneous involvement, a higher expression of SATB1, nMT, cMT and Ki-67 was found in patients with clinical or histological involvement of lymph nodes (N1-3 vs. N0) (p<0.001, p=0.002, p<0.001 and p=0.1, respectively). A marked correlation was observed between SATB1 and Ki-7 (Spearman correlation test: r=0.53, p<0.001). No associations between SATB1, nMT and cMT expression and demographic data nor overall survival were found. Conclusion: Our study provides data on the differences in the expression of SATB1 and cMT regarding differential diagnosis of MF and tumor-node-metastasis-blood staging. Additionally, our report documented significantly different expression levels of MTI/II and Ki-67 according to the advancement of the disease. In view of these data, the role of studied factors in the development of this type of cutaneous T-cell lymphoma is postulated. Our results indicate that both SATB1 and MTI/II may be of diagnostic value, but our study revealed no prognostic significance; however, given the small number of reports focusing on this topic, further studies are required.