Expression, purification, refolding, and characterization of octreotide-interleukin-2: A chimeric tumor-targeting protein

Abstract

Abstract. The targeting of tumor cells by peptides for drug delivery is a promising strategy for cancer therapy. Interleukin-2 (IL-2), which mediates anti-tumor cellular immune responses, has been approved as a therapy for cancer. However, the serious side effects and short half-life of recombinant IL-2 (rIL-2) has limited its use clinically. Somatostatin receptors (SSTRs), which are expressed in a large number of human tumors, are the targets for in vivo tumor targeting. In this study, we have constructed and expressed a novel chimeric recombinant protein containing octreotide analogs and IL-2 in order to target the SSTR binding with tumor cells. The fusion protein somatostatin receptor targeted interleukin-2 (SIL), which was purified from bacterial inclusion bodies and refolded with high purity, was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography. Tryptophan emission fluorescence was used to measure the structural changes in SIL after renaturation. Cell proliferation experiments showed that this chimeric protein retained the biological activities of hIL-2. Furthermore, the tumor binding capacity of SIL acting through SSTRs was shown through co-immunoprecipitation. Competition binding with octreotide of tumor cells also confirmed that SIL binds to tumor cells through the target peptide octreotide. Moreover, the performance of SIL in stimulating the proliferation of lymphocyte cell lines after binding to tumor cells showed that the immunocytokine, SIL, retained its bioactivity at the tumor site. These results suggest that SIL is a recombinant fusion protein that may be used for tumor-targeted drug delivery.

Nanotechnology-Based Strategy for Enhancing Therapeutic Efficacy in Pancreatic Cancer: Receptor-Targeted Drug Delivery by Somatostatin Analog

“…The ligand-target SSTR2, chosen for this study, has the potential to enhance potency and minimize undesirable side effects. The studies have shown that the SSTR2 is highly expressed in PDAC cells and tissues, although there may be variations in findings across different studies [21][22][23][24][25][26][27][33][34][35]. This variability could be due to differences in measurement techniques, experimental conditions, or treatment methods with corresponding ligands.…”

“…This targeted approach improves therapeutic outcomes and minimizes damage to healthy cells, reducing the severe side effects typically caused by conventional chemotherapy and radiation. Apart from the markers mentioned above, it has been found that somatostatin receptor 2 (SSTR2) is abundantly expressed in PDAC cells [21][22][23][24][25][26][27]. Hence, it may be an attractive target for the related ligand-somatostatin-and its analogs, such as octreotide and lanreotide (Figure 1).…”

Rapid octreotide separation from synthetic peptide crude mixtures by chromatography on poly(styrene–co-divinylbenzene)-based reversed phases

“…More than 200 peptides are in clinical phases, and more than 400 are in advanced preclinical trials [2,3]. Somatostatin is a phylogenetically ancient, multigene family of peptides with two bioactive products, somatostatin-14 and somatostatin-28, acting as both neurotransmitters and neurohormones.…”

“…Peptide purification is usually conducted on a commercial column on silica-based reversed phase matrix [14]. 3 There have been important advances in the methodology of peptide purification, and probably the most significant of these is the introduction of reversed-phase high performance liquid chromatography (HPLC). In reversed-phase chromatography, a very broad range of tailor-made stationary phases can be available, which derive from different materials (e.g.…”

Association Between Insulin-like Growth Factor-2 Expression and Prognosis after Transcatheter Arterial Chemoembolization and Octreotide in Patients with Hepatocellar Carcinoma

“…As a result, it is the largest difficulty in the treatment. Somatostatin can combine with somatostatin receptor (SSTR) expressed by tumor cells and then inhibit promoting tumor growth hormone or cytokine's production and adjust tumor blood supply (Hasskarl et al, 2011;Jiang et al, 2011;Zhang et al, 2011;Laznicek et al, 2012;Niu et al, 2012). Insulin-like growth factor-2 (IGF-2) is an important angiogenic factor during the process which HCC induced neovascularization (El Tayebi et al, 2011;Rehem et al, 2011;Wachter et al, 2012 of HCC.…”