Development of a real-time imaging system for hypoxic cell apoptosis

Abstract

Hypoxic regions within the tumor form due to imbalances between cell proliferation and angiogenesis; specifically, temporary closure or a reduced flow due to abnormal vasculature. They create environments where cancer cells acquire resistance to therapies. Therefore, the development of therapeutic approaches targeting the hypoxic cells is one of the most crucial challenges for cancer regression. Screening potential candidates for effective diagnostic modalities even under a hypoxic environment would be an important first step. In this study, we describe the development of a real-time imaging system to monitor hypoxic cell apoptosis for such screening. The imaging system is composed of a cyclic luciferase (luc) gene under the control of an improved hypoxic-responsive promoter. The cyclic luc gene product works as a caspase-3 (cas-3) monitor as it gains luc activity in response to cas-3 activation. The promoter composed of six hypoxic responsible elements and the CMV IE1 core promoter drives the effective expression of the cyclic luc gene in hypoxic conditions, enhancing hypoxic cell apoptosis visualization. We also confirmed real-time imaging of hypoxic cell apoptosis in the spheroid, which shares properties with the tumor. Thus, this constructed system could be a powerful tool for the development of effective anticancer diagnostic modalities.

Personalized Tumor Growth Prediction with Multiscale Tumor Modeling

“…A strong correlation for both hypoxic (r=0.992) and normoxic (r=0.991) conditions is observed on tumor volume. Also as seen in Figure 2 in hypoxia which could be defined as 10% O 2 of normoxia [18] apoptic region is considerably larger and tumor shows migrative behavior which is also in line with experimental results [19,20]. In the figure, Many studies have shown that glucose is an important factor in tumor growth.…”

Personalized Tumor Growth Prediction Using Multiscale Modeling

“…Also as seen in Figure 6, under hypoxia, which could be defined as 10% O 2 of normoxia (37), the apoptotic region is considerably larger and tumor shows migratory behavior. This phenomenon can be observed in experimental studies (38,39). 8.…”

Real-time visualization of intratumoral necrosis using split-luciferase reconstitution by protein trans-splicing

“…Furthermore, we devised this system to only work in a hypoxic environment so that it can be utilized for screening anticancer drugs targeting cancer stem cells, since they tend to reside in hypoxic regions. 15 …”

“…Furthermore, we devised this system to only work in a hypoxic environment so that it can be utilized for screening anticancer drugs targeting cancer stem cells, since they tend to reside in hypoxic regions. 15 In radiation therapy, a major component of cancer therapy (along with surgery and chemotherapy), the frequency at which apoptosis is induced in tumors is known to be as low as several percent, regardless of the p53 status. 16 In addition, radiation not only directly causes necrosis in tumor cells but also causes tumor vascular damage, resulting in secondary necrosis in tumor cells via oxygen and nutrient depletion.…”