Novel EGFR‑bispecific recombinant immunotoxin based on cucurmosin shows potent anti‑tumor efficiency in vitro

Abstract

Epidermal growth factor receptor (EGFR) is overexpressed in various tumors and is associated with cancer initiation, progression, and poor prognosis. Despite the achievements made by tyrosine kinase inhibitors and monoclonal antibodies in certain cases, many patients have not benefited from such treatment due to resistance. Immunotoxins (ITs) are antibody-cytotoxin chimeric molecules with specific cell killing ability, which have achieved different degrees of success in the treatment of a wide range of cancers in clinical trials. The aim of the current study was to examine a novel targeting EGFR recombinant immunotoxin Bs/cucurmosin (CUS) generated by fusing CUS to the EGFR-specific nanobody 7D12-9G8. Bs/CUS was successfully expressed in Escherichia coli strain BL21 (DE3) in a soluble form. Furthermore, it retained binding capacity and specificity with EGFR and was superior to rE/CUS, a monospecific IT we reported previously. In vitro results showed that Bs/CUS could be internalized into the cytoplasm and selectively kill cells in the picomolar range. Flow cytometry showed that Bs/CUS killed the cells mediated by the apoptosis pathway. Taken together, results of the current study indicated that Bs/CUS is a promising candidate that should be further evaluated as a cancer therapeutic for the treatment of EGFR-positive tumors.

DT389-YP7, a Recombinant Immunotoxin against Glypican-3 That Inhibits Hepatocellular Cancer Cells: An In Vitro Study

“…Data of cell cycle analysis obtained from flow cytometry revealed that our recombinant IT arrests the HepG2 cell cycle at the G2 phase. Previous studies have been shown that ITs can impress cell cycles at G1/S phases [42][43][44]. Correlation among DNA fragmentation, apoptosis, and cell cycle arrest has been extensively investigated.…”

Nanobodies Enhancing Cancer Visualization, Diagnosis and Therapeutics

“…Additionally, tumor growth was efficiently inhibited by one anti-HER2-PE24X7 immunotoxin in vivo ( Table 3 ) [ 59 ]. These studies demonstrate the potential of combining Nbs with toxins for the treatment of tumors [ 58 , 59 ].…”

“…Moreover, an anti-EGFR Nb-cucurmosin immunotoxin was shown to inhibit the cell viability of EGFR-expressing tumor cell lines as well as induce HepG2 and A549 apoptosis (Table 3) [57]. More recently, Zhang et al (2020) demonstrated that a bispecific anti-EGFR-Nb-cucurmosin immunotoxin selectively kills cancer cells through apoptosis (Table 3) [58]. Cao et al (2020) produced three anti-HER-2 immunotoxins by linking anti-HER-2 sdAb to the PE24X7 toxin [59].…”

“…Bispecific anti-EGFR-Nb-cucurmosin Selectively kills cancer cells through apoptosis [58] anti-HER-2-PE24X7 High selectivity and cytotoxicity. Effective tumor growth inhibition [59] EGa1-L Decreased EGFR levels, EGFR sequestration, receptor degradation and inhibition of tumor cell proliferation [60] AG538-loaded EGa1-liposomes AG538 delivery, EGFR blockade, IGF-1R stimulation and inhibition of tumor cell proliferation [61] Rhodamine-labeled EGa1-micelles High binding and uptake through EGF receptor interaction.…”

Antibody-Based Immunotoxins for Colorectal Cancer Therapy

“…Although “Bs” stands for bispecific, perhaps it would be more appropriate to use the denomination of biparatopic. In cytotoxicity assays with the CRC cell line SW1116, Bs/CUS had a 55-fold increase in activity at 72 h compared to rE/CUS [ 155 ]. Given the small size of each sdAb, the molecular weight of Bs/CUS (58 kDa) is still under the glomerular filtration threshold.…”