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姐妹染色单体交换试验与微核试验对子宫颈癌患者放疗后遗传学损伤评估作用的研究

The Study of Sister Chromatid Exchange Assay and Micronucleus Assay as Biomarkers for Evaluating Radiotherapy Induced Cytogenetic Damage of Cervical Carcinoma Patients

【作者】 高明月

【导师】 王德华;

【作者基本信息】 天津医科大学 , 妇产科学, 2004, 硕士

【摘要】 目的: 探讨子宫颈癌患者外周血淋巴细胞姐妹染色单体交换(SCE)率、微核(MN)率的自发水平;接受放射治疗后子宫颈癌患者外周血淋巴细胞姐妹染色单体交换率、微核率的变化及二者作为细胞遗传学指标对电离辐射诱发的染色体损伤的评估作用;膀胱粘膜脱落上皮细胞微核率在放疗中的变化,及其作为反映子宫颈癌患者放疗中放射线对膀胱粘膜上皮细胞染色体损伤指标的临床适用性。 方法: 取15例子宫颈鳞状细胞癌(Ⅱb~Ⅲb期)患者放疗前与放疗中外周静脉血,进行姐妹染色单体交换试验与胞质分裂阻滞法微核试验。取5例患者采血当日晨起第二次尿液,进行膀胱粘膜上皮脱落细胞微核试验。 结果: 1.子宫颈癌患者SCE率为7.12±2.16,MN率为15.93±5.91‰,均显著高于健康人(P<0.001)。 2.子宫颈癌患者放疗开始后平均SCE率开始升高,升高的SCE率与累积剂量间无明显的线性关系,呈波动形式上升,累积剂量达20Gy、30Gy、50Gy时SCE率与治疗前差别有统计学意义(P<0.05)。当累积剂量达20Gy时,SCE率达最高峰;20Gy之后SCE率有所下降,放疗累积剂量达40Gy时,SCE率与放疗前差别无统计学意义;50Gy时再次升高。 3.放疗开始后子宫颈癌患者的外周血淋巴细胞MN率较放疗前明显升高,MN率随放疗剂量增加而升高呈线性关系,二者显著相关,其直线回归 天津医科大学硕士学位论文方程为:Y刚产66.9 17+3.ol6x。,(r=o.976,尸<0.001)。 4.放疗开始后子宫颈癌患者的SCE率、N幻,率随剂量升高均有改变,但二者显示不同的敏感性,N幻,率在放疗累积剂量达10Gy时即明显高于治疗前水平,SCE率在累积剂量达20Gy时方显著高于治疗前水平。 5.放疗开始后子宫颈癌患者膀肤粘膜上皮脱落细胞平均MN率较放疗前增高,但差别无统计学意义。结论: 1.子宫颈癌患者自发的外周血淋巴细胞姐妹染色单体交换率与微核率高于健康人,子宫颈癌患者为染色体不稳定人群。 2.放疗开始后子宫颈癌患者外周血淋巴细胞姐妹染色单体交换率与微核率较放疗前显著升高,微核率与放疗剂量呈良好的剂量一效应关系。 3.放疗对人体染色体具有一定的损伤作用,外周血淋巴细胞姐妹染色单体交换试验与胞质分裂阻滞法微核试验是有效的对子宫颈癌患者放疗后染色体损伤进行评估的细胞遗传学指标,微核试验反映放疗后遗传学损伤较为敏感。 4.膀脐粘膜上皮脱落细胞微核试验作为反映子宫颈癌患者放疗中放射线对膀眺粘膜上皮细胞染色体损伤指标的临床应用性不理想。

【Abstract】 Objective:To study the spontaneous frequency of sister chromatid exchange (SCE) and micronucleus (MN) in peripheral blood lymphocytes (PBL) of patients with cervical carcinoma; the variety of SCE frequency and MN frequency during radiotherapy; the applicability of SCE assay and MN assay as cytogenetic markers for evaluating in vivo radiation induced chromosome damage; the variety of MN frequency in bladder mucosa exfoliated cells during radiotherapy and the clinical applicability of MN assay in bladder mucosa exfoliated cells as a useful biomarker for evaluating radiotherapy induced bladder mucosa cell’s chromosome damage. Methods:Collected 15 cervical carcinoma patients’ peripheral blood before and during radiotherapy, the SCE assay and cytokinesis-blocked MN assay were applied. At the same day 5 of the 15 patients’ second urine in the morning were collected and MN assay in bladder mucosa exfoliated cells was applied. Result:1 . Significant difference of spontaneous SCE frequency (7.12 + 2.16) and MN frequency (15.93 5.91%) were observed between the cervical carcinoma patients and healthy population (P<0.001) .2 . After the initiation of radiotherapy, the average SCE frequencysignificantly increased but no correlation was found between the SCE frequency and radiation dose. There was a statistical difference at dose of 20 Gy, 30 Gy and 50 Gy compared to 0 Gy (P<0.05). At the accumulated dose of 20 Gy, the SCE frequency achieved the max value; then the SCE frequency declined, at the accumulated dose of 40 Gy, there was not statistic difference compared to OGy; at the accumulated dose of 50Gy, the SCE frequency increased again.3 . The MN frequency in PBL increased linearly with the radiation dose as YMNF=66.917+3.016Xdose (r=0.976, PO.001); they had a significant correlation.4. After the initiation of radiotherapy, the SCE frequency and MN frequency differed with the radiation dose with different sensitivity. The MN frequency rose significantly at the accumulated dose of 10 Gy, but the SCE frequency did not raise until at the dose of 20 Gy.5. After the initiation of radiotherapy the mean MN frequency in bladder mucosa exfoliated cells increased but no statistical difference was found. Conclusions:1 . The spontaneous frequency of SCE and MN in PBL of patients with cervical carcinoma are significantly higher than that in normal individuals, the instability of chromosome of the cervical carcinoma patients is increased.2 . After the initiation of radiotherapy the average frequency of SCE and MN were significantly increased and a good dose-response relationship was observed between MN frequency and radiation dose.3 . Radiotherapy can induce DNA damage, sister chromatid exchange assay and cytokinesis-blocked micronucleus assay in peripheral blood lymphocytes are effective cytogenetic markers to evaluate the radiation induced chromosome damage, and micronucleus assay is more sensitive.4 . The clinical application of MN assay in bladder mucosa exfoliated cells as a useful biomarker for monitoring radiotherapy induced bladder mucosa cell’schromosome damage is not ideal.

  • 【分类号】R737.33
  • 【下载频次】148
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