Mapping the Human Vasculature by In Vivo Phage Display

In vivo phage display screenings by intravenous injection of a random phage-displayed peptide library allow for the selection of peptides that localize to specific vascular beds. At the University of Texas MD Anderson Cancer Center, we have had the opportunity to perform phage display screenings in cancer patients in order to select for cancer specific targets directly in humans. These targets serve to define biochemical diversity of endothelial cell surfaces and can be validated and explored towards the design of vascular-targeted pharmacology. In the most recent patient screen, samples were recovered from hepatocellular carcinoma (HCC) as well as 26 additional tissues. High-throughput sequencing and multidimensional bioinformatics analysis of recovered peptides led to the identification of extensive panels of motifs that are predicted to distinctly localize to tissue-specific vascular beds. Utilizing peptide affinity purification and phage based binding assays, we have shown that the HCC targeting peptide (SGVGAASL) identified from this patient screen, selectively binds to HCC in vitro as well as in vivo facilitated by a receptor mediated interaction with the giantin protein. FACS and protein fractionational experiments showed that the giantin polypeptide, normally considered an intracellular protein, is uniquely expressed on the surface of HCC cell lines as well as activated endothelial cells. shRNA mediated depletion of giantin expression lead to a loss of proliferation and adhesion in cancer cells. Finally, an extensive study of giantin expression in patient HCC tissue uncovered a unique expression pattern on the surface of tumor-associated vasculature. Collectively, these data support a functional role for giantin on the surface of HCC tumor endothelium that could potentially be exploited for delivery of imaging and therapeutic agents. Ultimately, this work serves as the foundation of a high-throughput integrative platform for discovery and validation of tissue-specific motifs towards a comprehensive understanding of the vascular landscape in humans

Neuroinflammatory response in human derived cerebral oragnoids to proton FLASH and conventional radiotherapy

https://openworks.mdanderson.org/sumexp21/1062/thumbnail.jp

Analysis of pseudoprogression after proton or photon therapy of 99 patients with low grade and anaplastic glioma

Background and purpose: Proton therapy is increasingly used to treat primary brain tumors. There is concern for higher rates of pseudoprogression (PsP) after protons compared to photons. The purposes of this study are to compare the rate of PsP after proton vs. photon therapy for grade II and III gliomas and to identify factors associated with the development of PsP. Materials and methods: Ninety-nine patients age >18 years with grade II or III glioma treated with photons or protons were retrospectively reviewed. Demographic data, IDH and 1p19q status, and treatment factors were analyzed for association with PsP, progression free survival (PFS), and overall survival (OS). Results: Sixty-five patients were treated with photons and 34 with protons. Among those with oligodendroglioma, PsP developed in 6/42 photon-treated patients (14.3%) and 4/25 proton-treated patients (16%, p = 1.00). Among those with astrocytoma, PsP developed in 3/23 photon-treated patients (13%) and 1/9 proton-treated patients (11.1%, p = 1.00). There was no difference in PsP rate based on radiation type, radiation dose, tumor grade, 1p19q codeletion, or IDH status. PsP occurred earlier in oligodendroglioma patients treated with protons compared to photons, 48 days vs. 131 days, p < .01. On multivariate analyses, gross total resection (p = .03, HR = 0.48, 95%CI = 0.25–0.93) and PsP (p = .04, HR = 0.22, 95% CI = 0.05–0.91) were associated with better PFS; IDH mutation was associated with better OS (p < .01, HR = 0.22, 95%CI = 0.08–0.65). Conclusions: Patients with oligodendroglioma but not astrocytoma develop PsP earlier after protons compared to photons. PsP was associated with better PFS

Top 50 gene alterations over time for 70 patients with paired normals.

Heat map displaying the top 50 genes ranked by occurrence for 70 patients (216 samples) grouped by timepoint collection during chemoradiation.</p

Computational pipeline for whole exome sequencing data.

Workflow depicting preprocessing, variant calling and data analysis tools and parameters implemented to analyze WES data acquired from tumor DNA collected by cervical swab.</p

Patient characteristics.

Patient characteristics.</p

Gene list with alteration type and frequency for all samples.

(CSV)</p

Top 50 gene alterations over time for 33 patients with all four-time points.

Heat map displaying the top 50 genes ranked by occurrence for 33 patients (132 samples) grouped by timepoint collection during chemoradiation.</p

Overall gene alterations from swab acquired tumor samples (patients 2–30) is similar to landscape of TCGA cervical squamous cell carcinoma dataset.

(A) Ninety-four percent (1339/1430) of altered genes in baseline samples (defined as substitutions, insertions or deletions in gene) were also identified in the TCGA dataset, suggesting accurate identification of mutated genes related to cervical cancer. (B) The distribution of the top 30 most altered genes in study samples 2–30 and in TCGA(C) was also similar. (TIF)</p