Developing molecule imaging technology to visualize the metastasis of the cancer cells is important to facilitate an enhanced understanding of tumor biology. Staining lysosomes for the purpose of tracing cells can minimize potential interference to the cellular activities. In this study, we designed and synthesised a lysosome-targeted live cell tracking bioprobe with excellent optical properties and superior biocompatibility, which could enrich and stabilize in lysosomes to eliminate efflux after staining the cells. This bioprobe (Cy-Lyso) consists of cyanine near-infrared (NIR) fluorophore and p-fluorobenzenesulfonyl group. In the present work, p-fluorobenzenesulfonyl group was proved to be a lysosomal targeting motif independent of pH response. The cyanine dye can realize the transformation from mitochondrial targeting to lysosomal targeting after connecting with p-fluombenzenesulfonyl, and thereby long term fluorescence in living cells. This probe was utilized for sustained fluorescence labeling of living cells, successful located the position of lung cancer cells A549 in co-culture status. We further utilized this probe to label A549 cells and observe the metastasis way of A549 in vivo, and revealed that the liver and intestine are the main metastasis organs of A549 cells. In summary, this study provides an effective tool for basic research and clinical research on single cell behavior.

OBJECTIVE:To evaluate the clinical parameters for association with risk of radiation-induced lung injury in patients after three-dimensional (3D) conformal radiation therapy for lung cancer. METHODS: Seventy patients treated for non-small cell lung cancer were retrospectively evaluated, which were divided into two arms according to whether radiation-induced lung injury developed. The clinical parameters related to radiation-induced lung injury were divided into four groups: general state of health and systematic process, tumor-related factors, treatment except radiotherapy, radiotherapy-related factors. Univariate and multivariate analyses were performed to evaluate the data for association between clinical parameters and radiation-induced lung injury. RESULTS: In univariate analyses, GTV (P=0.009), ipsilateral lung MLD (P=0.017), ipsilateral lung V20 (P=0.036) and total lung MLD (P=0.034) were associated with radiation-induced lung injury. In multivariate analysis, ipsilateral lung MLD was the only variable associated with radiation-induced lung injury,P=0.019. CONCLUSIONS: GTV, ipsilateral lung MLD, ipsilateral lung V20 and total lung MLD are useful indicators of risk for development of radiation-induced lung injury after 3D conformal radiation therapy in patients with lung cancer.