Effect of anti-CCR4 monoclonal antibody (mogamulizumab) on adult T-cell leukemia-lymphoma: cutaneous adverse reactions may predict the prognosis.

Adult T-cell leukemia-lymphoma (ATL) is one of the most malignant lymphomas with poor prognosis. ATL cells express CC chemokine receptor 4 (CCR4) and mogamulizumab, a monoclonal antibody against CCR4 that exhibits very strong cytotoxicity for ATL cells via antibody-dependent cellular cytotoxicity. Although its effect is dramatic in ATL, serious adverse reactions such as Stevens-Johnson syndrome have been reported. However, these eruptions can appear as therapeutic signs of mogamulizumab. We evaluated the effectiveness of mogamulizumab in five acute-type ATL patients. Peripheral blood (PB) and lymph nodes (LN) were affected in three and four patients, respectively. In PB, complete response (CR) was obtained in all three patients and partial response (PR) was recorded in LN of one patient. In skin lesions, four of five patients manifested CR; in two, the lesions worsened after the start of mogamulizumab treatment and subsequently improved. In these lesions, CD4(+) 8(-) 25(+) ATL cells were replaced by CD3(+) 8(+) cytotoxic T cells. Cutaneous adverse reactions (CAR) developed in two patients with CR; they did not show a relapse of ATL over the course of 9 months. Our findings suggest that mogamulizumab should be continued and surface marker evaluation should be performed even in patients whose skin lesions show aggravation, and that CAR may be a marker for a favorable prognosis.

p53R2 is a prognostic factor of melanoma and regulates proliferation and chemosensitivity of melanoma cells.

BACKGROUND: The treatment of melanoma, an aggressive, chemo-resistant skin cancer characterized by rapid metastasis and a poor prognosis, requires the development of innovative therapies with improved efficacy. The p53R2 gene that encodes the ribonucleotide reductase small subunit 2 homologue is induced by several stress signals including DNA-damaging agents that activate p53. The p53R2 gene product increases the deoxynucleotide triphosphate pool in the nucleus; this facilitates DNA repair and synthesis. OBJECTIVE: We examined the expression of p53R2 in melanoma and evaluated whether p53R2 is involved in the growth and proliferation of melanoma cells. Methods We examined the clinicopathological significance of p53R2 in melanoma. To investigate the role of p53R2 in melanoma we used KHm5 and KHm6 melanoma cells that express p53R2, and p53R2-targeting small interfering (si) RNA. RESULTS: p53R2 expression was detected immunohistochemically in 56 of 78 patients (71.8%). The expression of p53R2 was significantly correlated with the depth of invasion and the tumor stage. p53R2-targeting siRNA successfully knocked down p53R2 and significantly inhibited the growth of KHm5 and 6 cells. Moreover, The degree of KHm5 and 6 cell growth inhibition was greater in the presence of both p53R2-targeting siRNA and nimustine (ACNU) than with ACNU alone, suggesting that p53R2 silencing enhanced the chemosensitivity of KHm5 and 6 cells to ACNU. CONCLUSIONS: We propose p53R2 as a therapeutic target to enhance the effectiveness of chemotherapy in patients with p53R2-positive melanoma.