Oncofetal Chondroitin Sulfate Is a Highly Expressed Therapeutic Target in Non-Small Cell Lung Cancer

SIMPLE SUMMARY: While molecular targeted therapy has marginally improved outcomes of patients with non-small cell lung cancer (NSCLC), NSCLC remains a significant health care challenge with a poor prognosis. We hypothesized that a broad-spectrum oncofetal chondroitin sulfate (CS) glycosaminoglycan modification, redundantly expressed on cell surface proteoglycans and previously described in other solid tumor indications, could offer a prognostic and therapeutic handle on NSCLC. Here, we report that elevated oncofetal CS expression predicts poor disease-free and overall survival in four independent patient cohorts of early-stage NSCLC (n = 493), independent of KRAS and EGFR mutations. Additionally, we show that a novel preclinical oncofetal CS-targeting drug conjugate effectively eliminates NSCLC cells in vitro and inhibits KRAS-mutated NSCLC xenograft tumor growth in vivo. These results provide clinical and preclinical proof that oncofetal CS is an actionable prognosticator and therapeutic receptor in wild-type and KRAS-mutated NSCLC. ABSTRACT: Broad-spectrum therapeutics in non-small cell lung cancer (NSCLC) are in demand. Most human solid tumors express proteoglycans modified with distinct oncofetal chondroitin sulfate (CS) chains that can be detected and targeted with recombinant VAR2CSA (rVAR2) proteins and rVAR2-derived therapeutics. Here, we investigated expression and targetability of oncofetal CS expression in human NSCLC. High oncofetal CS expression is associated with shorter disease-free survival and poor overall survival of clinically annotated stage I and II NSCLC patients (n = 493). Oncofetal CS qualifies as an independent prognosticator of NSCLC in males and smokers, and high oncofetal CS levels are more prevalent in EGFR/KRAS wild-type cases, as compared to mutation cases. NSCLC cell lines express oncofetal CS-modified proteoglycans that can be specifically detected and targeted by rVAR2 proteins in a CSA-dependent manner. Importantly, a novel VAR2-drug conjugate (VDC-MMAE) efficiently eliminates NSCLC cells in vitro and in vivo. In summary, oncofetal CS is a prognostic biomarker and an actionable glycosaminoglycan target in NSCLC.