Human fibulin-3 protein variant expresses anti-cancer effects in the malignant glioma extracellular compartment in intracranial xenograft models

// Yanyan Li 1 , Yuan Hu 1 , Chuanjin Liu 1 , Qingyue Wang 1 , Xiaoxiao Han 1 , Yong Han 1 , Xue-Shun Xie 1 , Xiong-Hui Chen 2 , Xiang Li 3 , Eric R. Siegel 4 , Kambiz Afrasiabi 5 , Mark E. Linskey 5 , You-Xin Zhou 1 , Yi-Hong Zhou 1,5,6 1 Neurosurgery & Brain and Nerve Research Laboratory, 2 Department of Emergency Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China 3 Neuroepigenetic Reseach Lab, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia 4 Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, AR, USA 5 Brain Tumor Research Laboratory, Department of Surgery, University of California Irvine, Irvine, CA, USA 6 Ziren Research, Irvine, CA, USA Correspondence to: Yi-Hong Zhou, email: // You-Xin Zhou, email: // Keywords : protein therapeutics; GBM; tumor heterogeneity in vivo model; EGFR/NOTHC signaling; MMP2 Received : September 08, 2017 Accepted : October 25, 2017 Published : November 09, 2017 Abstract Background: Decades of cytotoxic and more recently immunotherapy treatments for malignant glioma have had limited success due to dynamic intra-tumoral heterogeneity. The dynamic interplay of cancer cell subpopulations has been found to be under the control of proteins in the cancer microenvironment. EGF-containing fibulin-like extracellular matrix protein (EFEMP1) (also fibulin-3) has the multiple functions of suppressing cancer growth and angiogenesis, while promoting cancer cell invasion. EFEMP1-derived tumor suppressor protein (ETSP) retains EFEMP1’s anti-growth and anti-angiogenic functions while actually inhibiting cancer cell invasion. Methods: In this study, we examined the therapeutic effect on glioblastoma multiforme (GBM) of an in vitro synthesized protein, ZR30, which is based on the sequence of ETSP, excluding the signaling peptide.Results : ZR30 showed the same effects as ETSP in blocking EGFR/NOTCH/AKT signaling pathways, when applied to cultures of multiple GBM cell lines and primary cultures. ZR30’s inhibition of MMP2 activation was shown not only for GBM cells, but also for other types of cancer cells having overexpression of MMP2. A significant improvement in survival of mice with orthotopic human GBM xenografts was observed after a single, intra-tumoral injection of ZR30. Using a model mimicking the intra-tumoral heterogeneity of GBMwith cell subpopulations carrying different invasive and proliferative phenotypes, we demonstrated an equal and simultaneous tumor suppressive effect of ZR30 on both tumor cell subpopulations, with suppression of FOXM1 and activation of SEMA3B expressions in the xenografts. Conclusion: Overall, the data support a complementary pleiotrophic therapeutic effect of ZR30 acting in the extracellular compartment of GBM.