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Objective To study the effect of Tamibarotene on the SH-SY5Y cell proliferation inhibition ability and the mRNA and protein expressions of tyrosine kinase receptor a (TrkA) and N-myc (MYCN) in order to provide some experimental bases for the treatment of neuroblastoma.Methods The SH-SY5Y cells were treated with different concentrations of Am80 (0,10,20,40,80,160 μmol/L) for 48 h,then Cell Counting Kit-8 (CCK-8) was used to test the cell proliferation.Reverse transcription PCR(RT-PCR) and Western blot were used to test the mRNA and protein expressions of TrkA and MYCN at 48 hours.Results When the concentration was 10 μmol/L,Am80 had no significant inhibitory effect on SH-SY5Y cells [(3.51 ± 1.68)％,inhibition ratio ＜ 5 ％];but when the concentration was 20 μmol/L,it showed weak inhibition [(9.60 ± 1.97) ％,inhibition ratio ＜ 10％].The inhibition rate of SH-SY5Y cell proliferation[(57.43 ± 4.95)％] was significantly enhanced at Am80 with a concentration of 80 μmol/L.The concentrations of Am80 could effectively inhibit SH-SY5Y cell proliferation in a dose-dependent manner(P ＜0.05).The expression of TrkA increased with the increase of Am80 concentration.Am80 significantly decreased the expression of MYCN in SH-SY5Y cells(10 μmol/L:0.65 ±0.05 vs.20 μmol/L:0.36 ±0.06),and the difference was statistically significant(P ＜ 0.05).Conclusions It is suggested that Am80 can effectively inhibit SH-SY5Y cell proliferation in a concentration-dependent manner.The underlying mechanism involves increasing the expression of TrkA by down-regulation of MYCN.
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Objective To summarize the clinical features of neuroblastoma (NB)with N - myc gene amplifi-cation in order to analyze tumor shrinkage and bone marrow remission in the early stage of chemotherapy,and to eva-luate the children's initial sensitivity to chemotherapy. Methods The medical records of 38 patients with N - myc am-plification of NB were reviewed (bone marrow or tumor tissues were positive during fluorescence in situ hybridization probe),who were treated between February 2012 to December 2016 at the Hematology Oncology Center,Beijing Chil-dren's Hospital,Capital Medical University. The regimens included chemotherapy,surgery,stem cell transplantation, radiotherapy,and maintenance treatment. The data were reviewed for the medical history. The variations of biomarker, bone marrow cells and the primary site were analyzed before and after 2 courses of CAV (Cyclophosphamide + Adriamy-cin + Vincristine)regimen chemotherapy,in order to observe the short - term effect of chemotherapy and the results were described with statistics. Results Total 38 cases were studied,22 boys(58. 9％)and 16 girls(42. 1％). The median age was 30 months. The primary sites of 37 cases of tumor were located in the retroperitoneal and adrenal area,1 case located in the posterior mediastinum. Bone marrow cytology was negative in 12 cases of them,but bone marrow biopsy suggested bone marrow metastasis,while bone marrow cytomorpholigic examinations were positive in the other 26 cases. Of all the 37 cases the lactate dehydrogenase (LDH)levels were reported higher than the normal value. LDH level was under 500 U/ L in one case,9 cases above 4000 U/ L. The neuron specific enolase (NSE)level of all the cases was higher than the normal and NSE level in 36 cases was higher than 100 μg/ L. In one patient the diameter of tumor was less than 5 cm,lager than 10 cm in 32 cases. The lesion of 33 tumor cases before chemotherapy by enhanced CT was ≤100 cm3 in 12 cases,> 100 - 500 cm3 in 11 cases,among which 6 cases ranged from 500 - 1000 cm3 ,4 cases larger than 1000 cm3 . All the 38 cases received 2 courses of chemotherapy. LDH levels of 4 cases became normal,and LDH levels fell under 500 U/ L in 18 cases,while LDH levels of the other 3 cases were above 1000 U/ L. Among 38 cases, the NSE level in 6 cases was reduced to normal,and 16 cases reduced to 25 - 100 μg/ L. The bone marrow examination of 36 cases reversed to negative. According to the image examination,the overall response rate after 2 courses of chemo-therapy was 84. 8％ . One case achieved very good partial remission,21 cases achieved partial response,7 cases a-chieved metastatic remission,2 cases had no remission,while 2 cases showed progression. After 2 courses of chemother-apy,the tumor diameter in 7 cases was less than 5 cm,while that of 22 cases was above 10 cm. Conclusions The ma-jority primary site of NB with N - myc gene amplification is located in retroperitoneal and adrenal area. Patients with the huge tumor have a heavy burden and the biomarker is always high at the early stage. NB with N - myc gene amplifica-tion is sensitive to chemotherapy. After 2 courses of chemotherapy,there is a sharp decrease in the level of biomarker and the tumor burden. Chemotherapy can diminish the burden of tumor in early stage. But because of the huge burden and the huge size of tumor,it's not the best time for surgery and stem cell collection. The patients should go on receiving chemotherapy for remission of disease.
ABSTRACT
We have analyzed paired samples of genomic DNA from peripheral leukocyte and primary tumor tissue from nine patients with retinoblastoma (RB) and from two RB cell lines, WERI-Rb-1 and Y79, to detect the molecular alterations of the retinoblastoma susceptibility gene (RB-1) and N-myc gene. In Southern analysis, RB-1 deletions in tumor tissues were detected in five patients (56%), one of these revealed a total loss of RB-1. N-myc amplification was found only in one (11.1%) out of nine patients. We also observed a total loss of RB-1 in WERI-Rb-1, and a more than 100-fold amplification of N-myc in Y79. The analysis of the relationship between molecular events and clinical characteristics such as age, sex, tumor laterality did not reveal any specific correlation. These results suggest that genetic backgrounds of RB in Korean patients are quite similar to those of reported cases elsewhere. The high sensitivity of our method in detecting the RB-1 loss indicates that this method can be a useful tool for initially screening a large number of tumors.