Ex vivo drug sensitivity screening predicts response to temozolomide in glioblastoma patients and identifies candidate biomarkers.

BACKGROUND: Patient-derived glioma stem-like cells (GSCs) have become the gold-standard in neuro-oncological research; however, it remains to be established whether loss of in situ microenvironment affects the clinically-predictive value of this model. We implemented a GSC monolayer system to investigate in situ-in vitro molecular correspondence and the relationship between in vitro and patient response to temozolomide (TMZ). METHODS: DNA/RNA-sequencing was performed on 56 glioblastoma tissues and 19 derived GSC cultures. Sensitivity to TMZ was screened across 66 GSC cultures. Viability readouts were related to clinical parameters of corresponding patients and whole-transcriptome data. RESULTS: Tumour DNA and RNA sequences revealed strong similarity to corresponding GSCs despite loss of neuronal and immune interactions. In vitro TMZ screening yielded three response categories which significantly correlated with patient survival, therewith providing more specific prediction than the binary MGMT marker. Transcriptome analysis identified 121 genes related to TMZ sensitivity of which 21were validated in external datasets. CONCLUSION: GSCs retain patient-unique hallmark gene expressions despite loss of their natural environment. Drug screening using GSCs predicted patient response to TMZ more specifically than MGMT status, while transcriptome analysis identified potential biomarkers for this response. GSC drug screening therefore provides a tool to improve drug development and precision medicine for glioblastoma.

Heart-on-a-Chip Model with Integrated Extra- and Intracellular Bioelectronics for Monitoring Cardiac Electrophysiology under Acute Hypoxia.

We demonstrated a bioelectronic heart-on-a-chip model for studying the effects of acute hypoxia on cardiac function. A microfluidic channel enabled rapid modulation of medium oxygenation, which mimicked the regimes induced by a temporary coronary occlusion and reversibly activated hypoxia-related transduction pathways in HL-1 cardiac model cells. Extracellular bioelectronics provided continuous readouts demonstrating that hypoxic cells experienced an initial period of tachycardia followed by a reduction in beat rate and eventually arrhythmia. Intracellular bioelectronics consisting of Pt nanopillars temporarily entered the cytosol following electroporation, yielding action potential (AP)-like readouts. We found that APs narrowed during hypoxia, consistent with proposed mechanisms by which oxygen deficits activate ATP-dependent K+ channels that promote membrane repolarization. Significantly, both extra- and intracellular devices could be multiplexed, enabling mapping capabilities unachievable by other electrophysiological tools. Our platform represents a significant advance toward understanding electrophysiological responses to hypoxia and could be applicable to disease modeling and drug development.

Expression of PD-1 in T-cell acute lymphoblastic leukemia cells and its clinical significance / 中国肿瘤生物治疗杂志

@# Objective: To investigate the expression and clinical significance of PD-1 molecule in tumor cells (T-ALL cells) derived from the patient with T-cell acute lymphoblastic leukemia (T-ALL). Methods: T-ALL cells from one patient and PBMCs from four healthy volunteers provided by the Department of Hematology in Jiangsu Provincial Hospital of Traditional Chinese Medicine in December 2015, and human 293T/PD-1 cells provided by Persongen Bio Therapeutics (Suzhou) Co., Ltd. were used for this study. The mouse T-ALL xenograft model was constructed by injecting T-ALL cells into tail vein of B-NDG mice, and flow cytometry was used to verify whether the cells obtained from the spleen of transplanted mice were mainly consisted of T-ALL cells. Flow cytometry was used to study the protein expression of PD-1 in T-ALL cells, and RT-PCR was applied to further verify the mRNA expression of PD-1 in T-ALL cells. The PD-1 gene in T-ALL cells was sequenced by SNP genotyping to detect whether the DNA sequence of PD-1 gene changed. PD-1 inhibitor was used in vitro to study their effects on proliferation, apoptosis, and the mRNA expression levels of related factors in T-ALL cells. Results: The mouse T-ALL xenograft model was successfully constructed and verified by flow cytometry as T-ALL. PD-1 was highly expressed at both mRNA and protein levels in T-ALL cells (all P<0.01). A C-to-T mutation was detected in the fifth exon of the PD-1 gene. PD-1 inhibitor had no significant effect on proliferation and apoptosis of T-ALL cells in vitro; PD-1 inhibitor up-regulated the mRNA expression of tumor-suppressor protein IGFBP3 and decreased the mRNA expression of oncoprotein SULT1A3 (all P<0.01). Conclusion: PD-1 is highly expressed in T-ALL cells, and PD-1 could be used as a target for clinical diagnosis and treatment for T-ALL.

Self-Replenishable Anti-Waxing Organogel Materials.

Solid deposition, such as the formation of ice on outdoor facilities, the deposition of scale in water reservoirs, the sedimentation of fat, oil, and grease (FOG) in sewer systems, and the precipitation of wax in petroleum pipelines, cause a serious waste of resources and irreversible environmental pollution. Inspired by fish and pitcher plants, we present a self-replenishable organogel material which shows ultra-low adhesion to solidified paraffin wax and crude oil by absorption of low-molar-mass oil from its crude-oil environment. Adhesion of wax on the organogel surface was over 500 times lower than adhesion to conventional material surfaces and the wax was found to slide off under the force of gravity. This design concept of a gel with decreased adhesion to wax and oil can be extended to deal with other solid deposition problems.