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Supplemental Figure 2: Neurocognitive analysis of mice by Morris watermaze (A and B), novel object test (C and D), and fear conditioning (E and F). Tests were performed as described (29). (G and H) Distance and velocity during the novel object training and test periods and overall averages.

Supplemental Figure 3: Effects of radiation and MnTnBuOE-2-PyP5+ on tumor cells. (A) LN-18 and (B) LN-229 glioblastoma cell lines treated with or without 50 nM MnTnBuOE-2-PyP5+ in clonogenic survival assays prior to various doses of radiation.

Supplemental Figure 4: Model of differential actions of MnTnBuOE-2-PyP5+ in causing the apoptosis of tumor during radiotherapy, while suppressing radation injury to surrounding normal tissue. Such effects are due to the differential redox environment of tumor vs normal cell, in particular much lower ability of cancer cell to remove cytotoxic hydrogen peroxide. Consequently, much higher levels of hydrogen peroxide already exist in tumor cell, and are greatly enhanced upon radiation. In normal cells and tissues, porphyrins suppress cycling inflammatory responses that may result from radiation also.

Cranial irradiation is a standard therapy for primary and metastatic brain tumors. A major drawback of radiotherapy (RT), however, is long-term cognitive loss that affects quality of life. Radiation-induced oxidative stress in normal brain tissue is thought to contribute to cognitive decline. We evaluated the effectiveness of a novel mimic of superoxide dismutase enzyme (SOD), MnTnBuOE-2-PyP5+(Mn(III) meso-tetrakis(N-n-butoxyethylpyridinium-2-yl)porphyrin), to provide long-term neuroprotection following 8 Gy of whole brain irradiation. Long-term RT damage can only be assessed by brain imaging and neurocognitive studies. C57BL/6J mice were treated with MnTnBuOE-2-PyP5+ before and after RT and evaluated three months later. At this time point, drug concentration in the brain was 25 nmol/L. Mice treated with MnTnBuOE-2-PyP5+/RT exhibited MRI evidence for myelin preservation in the corpus callosum compared with saline/RT treatment. Corpus callosum histology demonstrated a significant loss of axons in the saline/RT group that was rescued in the MnTnBuOE-2-PyP5+/RT group. In addition, the saline/RT groups exhibited deficits in motor proficiency as assessed by the rotorod test and running wheel tests. These deficits were ameliorated in groups treated with MnTnBuOE-2-PyP5+/RT. Our data demonstrate that MnTnBuOE-2-PyP5+ is neuroprotective for oxidative stress damage caused by radiation exposure. In addition, glioblastoma cells were not protected by MnTnBuOE-2-PyP5+ combination with radiation in vitro. Likewise, the combination of MnTnBuOE-2-PyP5+ with radiation inhibited tumor growth more than RT alone in flank tumors. In summary, MnTnBuOE-2-PyP5+ has dual activity as a neuroprotector and a tumor radiosensitizer. Thus, it is an attractive candidate for adjuvant therapy with RT in future studies with patients with brain cancer. Mol Cancer Ther; 14(1); 70–79. ©2014 AACR.

Previously, our group developed fluorescence-based alternative splicing reporters of epithelial plasticity to visualize phenotypic transitions in real time in vivo (Oltean et al., 2008; Oltean et al., 2006; Somarelli et al., 2013). We reasoned that our mesenchymal-epithelial transition (MET) reporters could be extremely useful to test the hypothesis that MET is a modulator of metastatic colonization in undifferentiated, sarcomatoid-like cancers. Along these lines, we generated a lineage-tracing reporter based on combined transcription and alternative splicing regulatory elements to measure the frequency of MET-like events during tumor growth and metastasis in the post-EMT Dunning rat AT3 model of prostate cancer. In a parallel set of experiments, we also used the combinatorial control strategy to drive a suicide reporter that kills cells undergoing MET to test the hypothesis that MET is required for metastatic colonization in undifferentiated, mesenchymal-like cancers. The combinatorial use of both transcription and alternative splicing regulation provided exquisite cell-type discrimination in the expression of enzymes, such as the Cre recombinase and Diphtheria A (DipA) toxin. Using the lineage tracing reporter system, we were able to quantify, for the first time, overall frequencies of MET during primary tumor and metastatic growth. Remarkably, we observed that the frequency of MET within primary tumors and metastatic nodules was not significantly different, with very low rates of MET taking place during the growth of tumors and metastases. Moreover, targeted killing of cells undergoing MET did not reduce the number of macrometastatic colonies in the lungs. This work demonstrates the ability of tumors to metastasize efficiently without the need for MET, and we suggest that this may be similar to the behavior of highly aggressive prostate carcinosarcomas or undifferentiated carcinomas. Using this system we will describe new experiments that will address differential behavior in different types of prostate cancer. Citation Format: Jason A. Somarelli, Jason A. Somarelli, Daneen Schaeffer, Daneen Schaeffer, Mathew S. Marengo, Mathew S. Marengo, Tristan Bepler, Tristan Bepler, Douglas Rouse, Anne F. Buckley, Jonathan I. Epstein, Andrew J. Armstrong, Mariano A. Garcia-Blanco, Mariano A. Garcia-Blanco. A long walk from FGFR2 alternative splicing to cancer progression. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr SS02-02. doi:10.1158/1538-7755.DISP13-SS02-02