Abstract
PurposeTargeted cancer therapies based on overexpressed receptors and the fractions containing immunotoxins and bacterial metabolites are one of the well-known methods to overcome the chemotherapy resistance of cancer cells. In this paper, we design ARA-linker-TGFαL3, using Arazyme, a Serratia proteamaculans metabolite, and a third loop segment of TGFα to target EGFR expressing breast cancer cells.MethodsAfter cloning in pET28a (+), the expression of recombinant protein was optimized in E. coli strain BL21 (DE3). MDA-MB-468 (EGFR positive) and MDA-MB-453 (EGFR negative) breast cancer cell lines were employed. Also, the chemotherapeutic drug, Taxotere (Docetaxel), was employed to compare cytotoxicity effects. Cell ELISA assessed the binding affinity of recombinant proteins to the receptor, and the cytotoxicity was detected by MTT and lactate dehydrogenase release assays. The interfacing with cancer cell adhesion was evaluated. Furthermore, the induction of apoptosis was examined by using flow cytometric analysis, and caspase-3 activity assay. Moreover, RT-PCR was conducted to study the expression of apoptosis (bax, bcl2, and casp3), angiogenesis (vegfr2), and metastasis (mmp2 and mmp9) genes. ResultsARA-linker-TGFαL3 revealed a higher binding affinity, cytotoxicity, and early apoptosis induction in MDA-MB-468 compared to the effects of Arazyme while both recombinant proteins showed similar effects on MDA-MB-453. In addition, the Taxotere caused the highest cytotoxicity on cancer cells through induction of late apoptosis. Meanwhile, the expression of angiogenesis and metastasis genes was decreased in both cell lines after treatment with either ARA-linker-TGFαL3 or Arazyme. ConclusionsOur in vitro results indicated the therapeutic effect of ARA-linker-TGFαL3 on breast cancer cells.
EGR1 expression: A calcium and ERK1/2 mediated PPARγ-independent event involved in the antiproliferative effect of 15-deoxy-Δ12,14-prostaglandin J2 and thiazolidinediones in breast cancer cells