宫颈癌细胞增殖和DNA倍体与放射敏感性的关系

为研究宫颈癌细胞增殖参数 S期比例 (SPF)、增殖指数 (PI)和 DNA倍体与宫颈癌放射敏感性的关系 ,探讨它们在预测宫颈癌放射敏感性中的价值。对 4 7例宫颈癌患者放疗前行宫颈癌组织取材 ,进行流式细胞术分析 ,在放疗过程中每周测量 1次宫颈局部瘤床的大小 ,计算肿瘤消退 1/ 2所需照射剂量 (D0 .5 ) ,研究 SPF、PI和 DNA倍体与D0 .5之间的关系。结果显示 :SPF与 D0 .5呈正相关 (r=0 .6 0 4 ,P<0 .0 1) ,PI与 D0 .5无明显关系 ,DNA倍体对 D0 .5的影响有显著性意义 (P<0 .0 5 )。提示 :宫颈癌细胞放疗前 SPF和 DNA倍体与放射敏感性有关 ,该两项指标有可能成为宫颈癌放射敏感性的预测指标     

常规染色体畸变分析法对AT细胞高辐射敏感性的研究

目的 研究毛细血管扩张性共济失调症(ataxia-telangiectasia,AT)患者皮肤的成纤维细胞系AT5BIVA(AT细胞)的高辐射敏感性。方法 以源于正常人皮肤的成纤维细胞系GM0639(GM细胞)为对照,用常规染色体畸变分析法,在AT细胞和GM细咆经60COγ射线0、1、2、3、4 Gy照射后,观察比较AT细胞和GM细胞之间染色体畸变率(CAF)的差异,并分别进行曲线拟合。结果 在0、1、2、3、4 Gy剂量下,AT细胞染色体畸变率明显高于GM细胞(P<0.05);AT和GM细胞染色体畸变率与剂量成正相关,均可拟合成剂量效应直线方程Y=a+bX,且AT细胞剂量效应直线回归方程斜率明显大于GM细胞(P<0.05)。结论 AT患者AT细胞的辐射敏感性显著高于GM细胞,具有高辐射敏感性。     

Radiosensitivity of colony-forming units of dog bone marrow in agar cultures

The radiosensitivity of colony-forming units in dog bone marrow was determined by a modified method of cloning hematopoietic cells in semisolid agar gel in diffusion chambers in vivo. The dose of radiation whose action was followed by preservation of 37% of the objects (D_o) was 144±14.8 rad (n=0.8) for committed precursor cells of granulocytopoiesis (CFUc) and 468±35.8 rad (n=0.9) for precursor cells forming stellate colonies of fibroblast-like cells (CFUf). It is concluded that the CFUf belong to the class of stromal precursors of hematopoietic organs. This system is suitable for the simultaneous study of hematopoietic and stromal precursor cells in dogs.Laboratory of Bone Marrow Culture and Transplantation, Central Institute of Hematology and Blood Transfusion, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 4, pp. 340–342, April, 1979.     

中性彗星分析法检测肿瘤细胞的放射敏感性

[目的]研究中性彗星分析法检测肿瘤细胞内在放射敏感性的可靠性和影响因素.[方法]人鼻咽高分化鳞癌细胞株CNE-1和人纤维肉瘤细胞株HT1080细胞,用6MV X线以0、100、200、300、400、600、800、1000cGy等不同剂量点照射,克隆形成法制定存活曲线,比较其放射敏感性的差异.然后进行两种细胞于600cGy照射后1、2、4、8h的中性彗星分析,以尾力矩为指标,动态检测不同时间点残留的DNA双链断裂,并与克隆形成分析结果相比较.[结果]克隆形成分析法显示CNE-1细胞的放射敏感性低于HT1080细胞,其2Gy照射后存活分数(SF2)和平均致死剂量D0值分别为0.397、0.331和1.898、1.287.两种细胞在照射后1、2、4h的中性彗星尾力矩分别为0.148±0.106、0.100±0.083、0.058±0.043和0.297±0.179、0.157±0.092、0.092±0.060,各时间点之间有显著性差异(P＜0.05),但差别逐渐减小;照射后2h和4h的尾力矩比值分别为0.637和0.630,与SF2比值和D0比值的倒数(0.834和0.678)较接近;两种细胞照射后8h的尾力矩比较差异无显著性.[结论]中性彗星分析法与克隆形成分析法的检测结果有确切的相关性,照射后一定时间内的残留DNA双链断裂有可能成为检测肿瘤细胞放射敏感性的指标.     

p53Mutations and Presence of HPV DNA Do Not Correlate with Radiosensitivity of Gynecological Cancer Cell Lines

Objective.The correlation betweenp53tumor suppressor gene mutations and the presence of high-risk human papillomavirus (HPV) DNA with thein vitroradiosensitivity of gynecological malignancies was studied in 26 cell lines derived from gynecological cancers of 23 patients.Methods.Comparison of the intrinsic radiosensitivity was performed with mean inactivation dose (D?) determined with the 96-well plate clonogenic assay.p53mutations were investigated with polymerase chain reaction and single-strand conformation polymorphism (PCR–SSCP) analysis and direct DNA sequencing, and the presence of HPV DNA was studied with PCR using HPV consensus primers.Results. p53mutations were found in 6 of 10 vulvar squamous cell carcinoma (SCC) lines. Nine vulvar and 1 vaginal SCC cell lines were HPV DNA negative and 1 vulvar cell line was HPV 16 positive. All 4 cervical SCC lines were HPV positive and possessed the wild-typep53.Three cell lines expressed HPV 16 and 1 HPV 68. Among 10 endometrial cancer cell lines, 2 cell lines with mutantp53and 1 HPV 16 positive cell line were found. No correlation could be demonstrated between inactivation of thep53gene and radiosensitivityin vitro;the cell lines were evaluated as one group or according to their anatomical origin or histology.Conclusion.Our results indicate that inactivation of thep53gene through mutation or binding with HPV DNA does not increase the resistance of gynecological malignancies to ionizing radiationin vitro.     

胞质分裂阻滞微核法对AT细胞高辐射敏感性的研究

目的 研究源于毛细血管扩张性共济失调症(ataxia-telangiectasia,AT)患者皮肤的成纤维细胞系AT5BIVA(AT细胞)的辐射敏感性.方法本实验以源于正常人皮肤的成纤维细胞系GM0639(GM细胞)为对照,采用胞质分裂阻滞微核法(Cytokinesis-Block micronucleus method),在AT细胞和GM细胞经60Co γ射线0、1、2、3、4 Gy照射后,观察比较AT细胞和GM细胞之间微核率及微核细胞率的差异,并分别进行曲线拟合.结果在1、2、3、4 Gy剂量照射下,AT细胞微核率及微核细胞率均明显高于GM细胞,其差异有非常显著性 (P＜0.01),并且两者微核率及微核细胞率均与剂量呈正相关,均可拟合成剂量效应直线方程y=a bx,微核率及微核细胞率直线回归方程斜率AT细胞明显大于GM细胞(P＜0.01).结论辐射敏感性AT细胞显著高于GM细胞,AT患者AT细胞具有高辐射敏感性.     

Expression and clinical significance of B cell translocation gene 2 in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is widely known as a highly fatal cancer, and thus it is important to identify tumor-specific and radiosensitivity-specific markers in ESCC. B cell translocation gene 2 (BTG2) has been considered a novel tumor suppressor gene or radiotherapy sensitivity-associated gene. However, the relationship between BTG2 and ESCC development and radiotherapy sensitivity is uncertain. The present study aims to explore the expression and clinical significance of B cell translocation gene 2 (BTG2) in ESCC by analyzing the RNAseq data from the TCGA and immunohistochemical staining of ESCC samples. We found that the level of BTG2 mRNA was significantly decreased in ESCC patients, and further decreased significantly in radiotherapy resistant patients compared to sensitive patients. The positive expression rate of BTG2 protein was 56.0% (103/184) in 184 ESCC tissue samples and 84.0% (42/50) in normal esophageal mucosal samples, respectively. The positive ratios of BTG2 expression in radiotherapy-sensitive group and radiotherapy resistant group were 57.9% (22/38) and 23.5% (4/17), respectively. Furthermore, the analysis indicates that the expression level of BTG2 significantly correlated with lymph node metastasis and clinical staging in ESCC patients. A multivariate analysis with Cox regression model showed that BTG2 level was an independent risk factor affecting the prognosis of ESCC patients. Above all, the downregulation of BTG2 may be used as a molecular marker to identify and predict ESCC progression and radiosensitivity.     

In vitro 3-dimensional tumor model for radiosensitivity of HPV positive OSCC cell lines

The incidence of oropharyngeal squamous cell carcinoma (OSCC) is increasing due to the rising prevalence of human papillomavirus (HPV) positive OSCC. HPV positive OSCC is associated with better outcomes than HPV negative OSCC. Our aim was to explore the possibility that this favorable prognosis is due to the enhanced radiosensitivity of HPV positive OSCC. HPV positive OSCC cell lines were generated from the primary OSCCs of 2 patients, and corresponding HPV positive cell lines generated from nodal metastases following xenografting in nude mice. Monolayer and 3 dimensional (3D) culture techniques were used to compare the radiosensitivity of HPV positive lines with that of 2 HPV negative OSCC lines. Clonogenic and protein assays were used to measure survival post radiation. Radiation induced cell cycle changes were studied using flow cytometry. In both monolayer and 3D culture, HPV positive cells exhibited a heterogeneous appearance whereas HPV negative cells tended to be homogeneous. After irradiation, HPV positive cells had a lower survival in clonogenic assays and lower total protein levels in 3D cultures than HPV negative cells. Irradiated HPV positive cells showed a high proportion of cells in G1/S phase, increased apoptosis, an increased proliferation rate, and an inability to form 3D tumor clumps. In conclusion, HPV positive OSCC cells are more radiosensitive than HPV negative OSCC cells in vitro, supporting a more radiosensitive nature of HPV positive OSCC.     

Assessment of the intrinsic radiosensitivity of glioma cells and monitoring of metabolite ratio changes after irradiation by 14.7‐T high‐resolution 1H MRS

Gliomas are the most common type of primary brain tumor. Radiation therapy (RT) is the primary adjuvant treatment to eliminate residual tumor tissue after surgery. However, the current RT guided by conventional imaging is unsatisfactory. A fundamental question is whether it is possible to further enhance the effectiveness and efficiency of RT based on individual radiosensitivity. In this research, to probe the correlation between radiosensitivity and the metabolite characteristics of glioma cells in vitro, a perchloric acid (PCA) extracting method was used to obtain water‐soluble metabolites [such as N‐acetylaspartate (NAA), choline (Cho), creatine (Cr) and succinate (Suc)]. Spectral patterns from these processed water‐soluble metabolite samples were acquired by in vitro 14.7‐T high‐resolution ¹H MRS. Survival fraction analysis was performed to test the intrinsic radiosensitivity of glioma cell lines. Good ¹H MRS of PCA extracts from glioma cells was obtained. The radiosensitivity of glioma cells correlated positively with the Cho/Cr and Cho/NAA ratios, but negatively with the Suc/Cr ratio. Irradiation of the C6 cell line at different X‐ray dosages led to changes in metabolite ratios and apoptotic rates. A plateau phase of metabolite ratio change and a decrease in apoptotic rate were found in the C6 cell line. We conclude that in vitro high‐resolution ¹H MRS possesses the sensitivity required to detect subtle biochemical changes at the cellular level. ¹H MRS may aid in the assessment of the individual radiosensitivity of brain tumors, which is pivotal in the identification of the biological target volume. Copyright © 2014 John Wiley & Sons, Ltd.     

Time in hemodialysis modulates the levels of genetic damage in hemodialysis patients

It is assumed that hemodialysis treatment can diminish the levels of genetic damage in circulating lymphocytes by cleaning the blood of uremic toxins that cause oxidative stress. However, the hemodialysis process by itself may also induce genomic damage by producing reactive oxygen species (ROS). We conducted a follow‐up study in a group of 70 hemodialysis patients followed for a mean time of 15 months. We investigated the effect of exposure time in hemodialysis on the levels of genetic damage in peripheral blood lymphocytes using the micronucleus assay. In addition, genetic damage after in vitro irradiation with 0.5 Gy was also analyzed to evaluate changes in radiosensitivity. Our results showed that, at the end of the study, there was a decrease in both the basal levels of genetic damage (9.9 ± 1.0 vs. 7.6 ± 0.7) and radiosensitivity values (38.5 ± 3.0 vs. 27.6 ± 2.4). We conclude that hemodialysis procedures may act as an ameliorating factor reducing the genetic damage present in chronic kidney disease patients. Environ. Mol. Mutagen. 55:363–368, 2014. © 2014 Wiley Periodicals, Inc.