Taylor M. Wilson

The ProtekDuo’s dual‐lumen design combined with its ability to be inserted percutaneously allows for its use in a wide variety of clinical scenarios. Therefore, it was chosen to be used as the venous cannula on cardiopulmonary bypass to treat a patient who had a high risk of right ventricular failure and a need for mechanical circulatory support postoperatively. Biventricular failure occurred during the patient’s course in hospital, and the ProtekDuo was used in a novel hybrid configuration using both the distal port on the ProtekDuo and the aortic cannula as outflow cannula for the extracorporeal membrane oxygenation circuit, and the proximal port on the ProtekDuo was used as the venous return. Gradually increasing ProtekDuo distal outflow and decreasing aortic cannula outflow facilitated an isolated and progressive loading of the left ventricle while maintaining support for the right ventricle. In total, four separate mechanical circulatory support configurations were used to support and optimize the patient’s hemodynamics. The ability to utilize a single cannula in a hybrid manner may be useful in patients requiring controlled weaning of mechanical circulatory support.

Implication Statement Medical student-led walk and talk programs, such as Walk with a Future Doc (WWAFD), provide a means for the medical community and community at-large to interact in a non-clinical setting. This environment can increase attendance accountability, enhance patient-provider relationships, and allow medical professionals to be leading examples of healthy, active living. We demonstrate the positive interest for this program, rationale of participants for joining, and the feasibility of its setup. As one of the only WWAFD programs in Canada, we encourage other medical schools to implement this program to promote continuity of hands-on, community-engaged learning amongst their students.

Glioblastoma is the most common primary brain tumor in adults. While the introduction of temozolomide chemotherapy has increased long-term survivorship, treatment failure and rapid tumor recurrence remains universal. The transcriptional regulatory protein, inhibitor of DNA-binding-1 (ID1), is a key regulator of cell phenotype in cancer. We show that CRISPR-mediated knockout of ID1 in glioblastoma cells, breast adenocarcinoma cells, and melanoma cells dramatically reduced tumor progression in all three cancer systems through transcriptional downregulation of EGF, which resulted in decreased EGFR phosphorylation. Moreover, ID1-positive cells were enriched by chemotherapy and drove tumor recurrence in glioblastoma. Addition of the neuroleptic drug pimozide to inhibit ID1 expression enhanced the cytotoxic effects of temozolomide therapy on glioma cells and significantly prolonged time to tumor recurrence. Conclusively, these data suggest ID1 could be a promising therapeutic target in patients with glioblastoma.Significance:These findings show that the transcriptional regulator ID1 is critical for glioblastoma initiation and chemoresistance and that inhibition of ID1 enhances the effect of temozolomide, delays tumor recurrence, and prolongs survival.

(A) From left: Lane 1-5 U251 CTR. Lane -. Negative control. Lane +. Positive control. Lane D+. Diluted positive control. Lane 7-10 ID1-/-U251.1. Lane 11-14 ID1-/-U251.2. (B) PCR method.

(A) Western blot analysis for the identification of two clones lacking ID1 protein expression, consistent with successful gene knockout by CRISPR. (B) DNA sequence analysis of chosen clones. Red boxes mark the sgRNA target sequence and denote predicted cut-site. (C) Cell viability was measured using Alamar Blue in a time-dependent manner. (D) Cells were cultured for 48h followed by staining with propidium iodide for flow cytometric analysis. Bar chart shows quantification of the cell cycle distribution.

Measurement of ID1 half-life by cycloheximide chase assays. U251 cells were pretreated with or without TMZ for 3 days, followed by treatment with cycloheximide for the indicated times. The cell lysates were then analyzed by Western blots.

(A) Spearman correlation of ID1 vs EGFR gene expression in all glioblastoma patients. (B) Spearman correlation of ID1 vs EGFR gene expression in the Classical subtype. (C) Spearman correlation of ID1 gene expression and EGFR_pY1173 RPPA in the Classical subtype. (D) Spearman correlation of ID1 gene expression and EGFR_pY1173 RPPA in all GBM patients with available RPPA data.

(A) TMZ IC50 curves for U251 control and U251.TR cells. (B) U251 and U251.TR cells colony forming assay at different concentrations of TMZ. (C) Western blot analysis for EGFR and p-EGFR-1068 from lysates of U251and U251.TR cells.

(A) Flow chart of patient sample analysis (B) Representative images of IHC staining for ID1 expression in a TMA cohort. Images of weak and strong intensity staining for tumor tissues are shown. (C) Representative qPCR analysis of ID1 expresssion in U251 cells. Cells were treated with 100uM TMZ for indicated timepoints. *P>0.1

(A) Representative H&E images of control and ID1 KO mouse brains. (B) ID1 KO mice demonstrated greater accumulation of TMEM within the brain tissues compared to control animals. TMEM-positive cells were diffusely distributed throughout the brain, while in the control group. The boxes indicate the areas shown at higher magnification. (C) Quantification of positive TMEM cells in the brain relative to area. **P<0.005 Western blot analysis shows successful gene knockout clone for ID1 protein expression in (D) MDA-MB231 and (E) A375 cells.