Title:Recombinant Expression of Cec-B Peptide in Escherichia coli with a Significant Anticancer Effect on Hepatocellular Carcinoma
Volume: 22
Issue: 9
Author(s): Hend Okasha, Sami Mohamed Nasr and Safia Samir*
Affiliation:
- Biochemistry and Molecular Biology Department, Theodor Bilharz Research Institute, Giza,Egypt
Keywords:
Cecropin-B, recombinant expression, peptide, Escherichia coli, hepatocellular carcinoma, anticancer peptide.
Abstract:
Background: Cecropin-B (Cec-B) is an Antimicrobial Peptide (AMP) found in insects.
Objectives: Recombinant production of Cec-B peptide in Escherichia coli (Rosetta™ DE3), and
studying its anticancer effect on Hepatocellular Carcinoma Cell line (HCC).
Methods: The Cec-B gene of Drosophila melanogaster was synthesized by PCR assembly using the
Simplified Gene Synthesis (SGS) method. To express the recombinant peptide in E. coli (Rosetta™
DE3); the synthesized gene was cloned into pET-15b expression vector. The recombinant peptide
was expressed as insoluble aggregates called Inclusion Bodies (IBs) using 2mM lactose inducer. IBs
were solubilized in a denatured form using 8 M urea followed by in-vitro protein refolding using
rapid dilution method. The refolded Cec-B was purified using cation-exchange SP-FF column. Cytotoxicity
of recombinant Cec-B (rCec-B) was reported on normal human lung cell line (WI-38),
and Hepatocellular carcinoma cell line (HepG2).
Results: The Cec-B gene was expressed and purified at concentration 1.212±0.1 mg/ml which represents
48.49±4% of the total proteins injected to the column (2.5±0.2 mg/ml). The safe dose of purified
rCec-B on normal WI-38 cells was calculated to be 1.57 mg/ml. The half-maximal Inhibitory
Concentration (IC50) of rCec-B on HepG2 cell line was calculated to be 25 μg/ml. Scanning
Electron Microscope (SEM) showed that untreated and treated HepG2 cells had cell diameters from
11-12.92 μm and 14.18-21.58 μm, respectively.
Conclusion: The results of this study revealed a successful expression of the rCec-B peptide using a
pET-based expression system with a simple purification step. The purified peptide could be considered
as a hopeful anticancer drug against HCC.
