从TRA-8/DR5寡聚体荧光显微镜成像中提取的一种新型成像生物标志物可预测TRA-8在乳腺癌和胰腺癌小鼠模型中的治疗效果。

A Novel Imaging Biomarker Extracted from Fluorescence Microscopic Imaging of TRA-8/DR5 Oligomers Predicts TRA-8 Therapeutic Efficacy in Breast and Pancreatic Cancer Mouse Models.

作者信息

Kim Harrison, Buchsbaum Donald J, Zinn Kurt R

机构信息

Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.

Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.

出版信息

Mol Imaging Biol. 2016 Jun;18(3):325-33. doi: 10.1007/s11307-015-0913-x.

DOI:10.1007/s11307-015-0913-x

PMID:26552657

Abstract

PURPOSE

The aim of the study was to develop a reliable quantitative imaging biomarker from fluorescence microscopic imaging of TRA-8/death receptor 5 (DR5) oligomer to predict TRA-8 therapeutic efficacy in human breast and pancreatic cancer mouse models.

PROCEDURES

Two breast (2LMP, SUM159) and two pancreatic (MIA PaCa-2, PANC1) cancer cell lines were used. 10(5) cells per cell line were placed in a culture dish and treated with Cy5.5-labeled TRA-8 overnight in vitro. Three fluorescence microphotographs (×20) were acquired from randomly selected areas, and about 300 cells were analyzed per cell line. Two-dimensional (2D) fluorescence signal distribution of Cy5.5-TRA-8 on each cell was measured. Gaussian curve fitting to the distribution was determined by the least square regression method, and the coefficient of determination (R (2)) of the fitting was found. In addition, two features of the best fitting Gaussian curve such as peak amplitude and the volume under the curve (VUC) were retrieved. A novel image biomarker was extracted by correlating the combination of R (2) value, peak amplitude, and the VUC with the logarithmic values of the half maximal inhibitory concentrations (IC50) of TRA-8 for the four cell lines or the percentage of tumor growth inhibition (%TGI) at a week of TRA-8 treatment in animal models.

RESULTS

Cy5.5-TRA-8 binding to DR5 receptors resulted in an oligomer on each cell membrane, and its fluorescence signal distribution followed Gaussian curve. Peak amplitude of fluorescence signal in the oligomeric region, R (2) value of the Gaussian fitting, and the VUC in TRA-8-sensitive cells were significantly higher than those in resistant cells (p < 0.05). The novel imaging biomarker was significantly correlated with either log10(IC50) or %TGI (p < 0.001).

CONCLUSION

The imaging biomarker extracted from the cellular distribution pattern of Cy5.5-TRA-8 may serve as a predictive biomarker of TRA-8 therapy for cancer patients.

摘要

目的

本研究的目的是从TRA - 8/死亡受体5（DR5）寡聚体的荧光显微镜成像中开发一种可靠的定量成像生物标志物，以预测TRA - 8在人乳腺癌和胰腺癌小鼠模型中的治疗效果。

程序

使用了两种乳腺癌（2LMP、SUM159）和两种胰腺癌细胞系（MIA PaCa - 2、PANC1）。每种细胞系10⁵个细胞置于培养皿中，在体外与Cy5.5标记的TRA - 8孵育过夜。从随机选择的区域获取三张荧光显微照片（×20），每个细胞系分析约300个细胞。测量每个细胞上Cy5.5 - TRA - 8的二维（2D）荧光信号分布。通过最小二乘回归法确定对该分布的高斯曲线拟合，并求出拟合的决定系数（R²）。此外，获取最佳拟合高斯曲线的两个特征，如峰值幅度和曲线下面积（VUC）。通过将R²值、峰值幅度和VUC的组合与TRA - 8对四种细胞系的半数最大抑制浓度（IC50）的对数值或动物模型中TRA - 8治疗一周后的肿瘤生长抑制百分比（%TGI）相关联，提取一种新的图像生物标志物。

结果

Cy5.5 - TRA - 8与DR5受体结合导致每个细胞膜上形成寡聚体，其荧光信号分布呈高斯曲线。TRA - 8敏感细胞中寡聚体区域的荧光信号峰值幅度、高斯拟合的R²值和VUC显著高于耐药细胞（p < 0.05）。这种新的成像生物标志物与log10（IC50）或%TGI显著相关（p < 0.001）。