ABSTRACT
Objective:To investigate the clinical features of patients with Langerhans cell histiocytosis (LCH), and analyze the association between BRAF V600E mutation status and clinical features. Methods:A retrospective analysis was carried out for the clinical data of 60 patients with LCH at the Department of Pediatric Oncology, Sun Yat-sen Memorial Hospital between April 2013 and December 2019.Among them, 39 patients undertook BRAF V600E mutation testing, which in paraffin-embedded tissue samples were detected by quantitative real-time PCR (qRT-PCR), and in peripheral blood and/or bone marrow were tested by high-throughput sequencing, for analyzing the correlation between BRAF V600E mutation and clinical characteristics of LCH. Results:(1)Clinical characteristics: the age of 60 LCH patients was (4.08±0.45) years, with 43 male cases and 17 female cases.Patients at young age (≤2 years) and with risk organ (RO+ ) and central nervous system (CNS) risk lesions involvement were concentrated in the multisystem involvement (MS) group ( P<0.05). (2)Therapeutic response after induction therapy: the response to induction therapy was achieved in 28 of 60 treated patients (41.7%) and 32 (53.3%) did not.After excluding stratification factors of treatment regimen, MS ( OR=6.855, 95% CI: 2.077-22.622, P=0.002) and the age≤2 years ( OR=4.944; 95% CI: 1.601-15.275; P=0.005) were risk factors in poor chemotherapy response.RO+ ( OR=8.250, 95% CI: 1.617-42.090, P=0.005) was a significant risk factor for a poor chemotherapy response in JLSG-02 treatment group.Differently, RO+ had no dramatic effect on chemotherapy response in CCHG-LCH-2019 treatment group.(3) BRAF V600E mutation: 39 patients were determined BRAF V600E status, with the positive rate of BRAF V600E mutation in paraffin-embedded tissue samples reaching 70.3%(26 cases). BRAF V600E mutation was not associated with early treatment response, age, sex, MS and RO+ ( P>0.05). However, the positive rate of BRAF V600E in children with MS and CNS risk lesions was higher than the controls, with 76.0% (19 cases) vs.57.1% (8 cases) and 74.1% (20 cases) vs.58.3% (7 cases), respectively.Totally, 3 of 8 cases were positive in bone marrow, with 2 cases of MS, and 1 case of multiple bone invasions, and 1 of 5 cases was positive in peripheral blood, with liver and spleen being involved. Conclusions:LCH patients with age≤2 years, MS and RO+ exhibited a poor response to initial treatment, required for more aggressive treatment strategy.Lesion with activating BRAF V600E mutations suggests that LCH is a clonal disorder.There may be great variability between BRAF V600E mutations and MS as well as CNS risk lesions.In the mutation dataset, part of patients had positive BRAF V600E mutations in bone marrow/peripheral blood.This might suggest a different pathogenesis in such patients, has a certain clinical sense in some aspect.
ABSTRACT
BACKGROUND: Arsenic trioxide is effective in the treatment of acute promyelocytic leukemia and is currently in use in clinical trials for the treatment of solid tumor types. Given that arsenic trioxide is able to arrest neuroblastoma cell cycle in the G2/M phase, the present study is, to the best of our knowledge, the first to investigate whether the combination of arsenic trioxide with mitosis-phase-specific antineoplastic agents (vinorelbine or docetaxel) or non-mitosis-phase-specific antineoplastic agents (etoposide or cisplatin) exert synergistic effects in cytotoxicity on the human SK-N-SH neuroblastoma cell line. METHODS: Neuroblastoma cells were either incubated with one of the four drugs individually, or preincubated with arsenic trioxide and then followed by another drug when cell cycle was arrested at the G2/M phase with the highest proportion. RESULTS: The results of the present study revealed that arsenic trioxide potentiated the apoptotic rate of neuroblastoma cells induced by chemotherapeutic drugs. The present study further demonstrated that preincubation with arsenic trioxide followed by a mitosis-phase-specific antineoplastic agent result in a higher cytotoxicity effect compared with a non mitosis-phase-specific antineoplastic agent. Along with the enhanced cytotoxicity in combination group, the cell cycle distribution demonstrated a decreased proportion of G2/M phase in the combination group. CONCLUSION: The in vitro study revealed that the pre-application of arsenic trioxide followed by mitosis-phase-specific antineoplastic agents potentiate the cytotoxic effects on neuroblastoma cells, therefore arsenic trioxide may be a promising therapeutic option for treating neuroblastoma.
