RESUMO
BACKGROUND: Bax-interacting factor-1 (Bif-1) binds to Bax, which in turn activates this proapoptotic protein. In the absence of Bif-1, the ability to induce apoptosis through the intrinsic pathway is greatly reduced. Merkel cell carcinoma (MCC) classically shows an aggressive behavior and lack of response to chemotherapy, which remains unexplained. Previous studies have documented the presence of Bax in MCC, but Bif-1 expression has not been evaluated. Herein, the expression of Bif-1 and Bax in cutaneous MCC is examined. MATERIALS AND METHODS: The immunohistochemical expression of Bif-1 and Bax protein was examined in nine cases of MCC. Both positive and negative controls were conducted. All the cases were reviewed by a single dermatopathologist. RESULTS: Bif-1 was detected in nine cases (100%), and Bax was expressed in six cases (66%). The percent positive cells for Bif-1 in MCC ranged from 85% to 98% positive (mean 93.9%). At the same time, decreased Bax expression was shown with 0-8% positive cells (mean 3.45%). CONCLUSION: The increased expression of Bif-1 in MCC is associated with low levels of Bax staining. These findings suggest that the upregulation of Bif-1 could in part be responsible for tumorigenesis in cutaneous MCC. As shown, Bax and Bif-1 expression are not exclusively antithetical; therefore, future studies evaluating the expression of both proteins should be conducted.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/biossíntese , Carcinoma de Célula de Merkel/metabolismo , Neoplasias Cutâneas/metabolismo , Proteína X Associada a bcl-2/biossíntese , Proteínas Adaptadoras de Transdução de Sinal/genética , Idoso , Idoso de 80 Anos ou mais , Apoptose/fisiologia , Carcinoma de Célula de Merkel/genética , Feminino , Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Cutâneas/genética , Proteína X Associada a bcl-2/genéticaRESUMO
Atypical fibroxanthoma (AFX) is a spindle cell neoplasm of the skin seen typically on sun-damaged skin of the elderly. Though described as a benign entity, local recurrence and distant metastasis have been reported. This study aims to investigate the potential pathogenic role of CD117, the c-kit receptor in AFX. CD117 was detected in 15 of the 16 cases (94%). The percentage of positive cells for CD117 expression among all tumors was approximately 30%. CD117 proved to be a very sensitive marker of AFX. This antibody may be a useful diagnostic adjunct in AFX.
Assuntos
Biomarcadores Tumorais/análise , Histiocitoma Fibroso Benigno/metabolismo , Proteínas Proto-Oncogênicas c-kit/biossíntese , Neoplasias Cutâneas/metabolismo , Idoso , Idoso de 80 Anos ou mais , Histiocitoma Fibroso Benigno/patologia , Humanos , Imuno-Histoquímica , Masculino , Neoplasias Cutâneas/patologiaRESUMO
Our retrospective analysis explored the role of leukemia cutis (LC) in disease progression of chronic myelomonocytic leukemia (CMML). Of 108 patients with CMML, 11 patients (10.2%) had LC including its equivalent (2 patients). Four of these patients developed acute myeloid leukemia (AML) within 0-4 months. The remaining 7 patients demonstrated increased monocytes (<20% blasts), with 3 demonstrating extramedullary involvement. Overall survival from LC to disease progression was 7.8 months. Overall survival from diagnosis to the last follow-up in patients with LC was 28.2 months, shorter than patients without LC (44 months). LC and its equivalent could predict disease progression to AML.