ABSTRACT
BACKGROUND/AIM: Protein phosphatase and tensin homolog (PTEN) is a tumor suppressor protein with potential to be a new biotechnological drug for PTEN-deficient cancer treatment. This study aimed to develop PTEN-based chimeric proteins (CPP-PTEN-THP) for human epidermal growth factor receptor 2 (HER2)-positive breast cancer treatment, addressing current limitations like inadequate delivery, poor tumor penetration, and low selectivity, while assessing their potential HER2-specific anticancer effects. MATERIALS AND METHODS: pCEFL-EGFP vector was used for both TAT-PTEN-LTV and KLA-PTEN-LTV construction. Non-contact co-cultures were employed using HEK-293T cells for protein expression, and HCC-1954 and MCF-7 cell lines for cytotoxicity testing. Protein detection was analyzed by western blotting and a docking prediction analysis was performed to infer the interactions. RESULTS: Endogenous and recombinant PTEN protein expression was confirmed in cell lysates. A 54-kDa signal matching the theoretical size of PTEN was detected, showing a greater level in TAT-PTEN-LTV (215.1±26.45%) and KLA-PTEN-LTV (129.2±1.44%) compared to endogenous PTEN. After the noncontact co-culture method, cytotoxic studies showed HCC-1954 preferential cell inhibition growth, with 25.95±0.9% and 12.25±1.29% inhibition by KLA-PTEN-LTV and TAT-PTEN-LTV respectively, compared to MCF-7 cells. An LTV-HER2 interaction model was proposed, inferring that LTV interactions are mainly due to the Pro, Trp, and Tyr residues that target HER2. CONCLUSION: The developed PTEN-based chimeric proteins have HER2-specific anticancer activity against HCC-1954 cells.
Subject(s)
PTEN Phosphohydrolase , Receptor, ErbB-2 , Recombinant Fusion Proteins , Humans , PTEN Phosphohydrolase/metabolism , PTEN Phosphohydrolase/genetics , Receptor, ErbB-2/metabolism , Receptor, ErbB-2/genetics , Recombinant Fusion Proteins/pharmacology , Recombinant Fusion Proteins/metabolism , Recombinant Fusion Proteins/genetics , Antineoplastic Agents/pharmacology , Cell Line, Tumor , HEK293 Cells , MCF-7 Cells , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Breast Neoplasms/genetics , Female , Molecular Docking Simulation , Coculture TechniquesABSTRACT
BACKGROUND/AIM: The epidermal growth factor receptor (EGFR) is over-expressed in several types of cancer, and monoclonal antibody therapy has been the strategy that has shown the best results. This study focused on the construction of a humanized single chain antibody (huscFv) directed against EGFR (HER1). MATERIALS AND METHODS: The CDR grafting method was used to incorporate murine complementarity determining regions (CDRs) of cetuximab into human sequences. A dot blot assay was used to examine the affinity of the huscFv secreted by HEK293T for EGFR. The inhibitory effect on the viability of A549 cells was evaluated using the WST-1 assay. RESULTS: The incorporation of murine CDRs of cetuximab into human sequences increased the degree of humanness by 16.4%. The increase in the humanization of scFv did not affect the affinity for EGFR. Metformin had a dose-dependent effect, with an IC50 of 46 mM, and in combination with huscFv, the cell viability decreased by 45% compared to the 15% demonstrated by huscFv alone. CONCLUSION: The CDR grafting technique is efficient for the humanization of scFv, maintaining its affinity for EGFR and demonstrating its inhibitory effect when combined with metformin in A549 cells.
Subject(s)
Cetuximab , ErbB Receptors , Metformin , Single-Chain Antibodies , Animals , Humans , Mice , A549 Cells/drug effects , Antibodies, Monoclonal, Humanized/pharmacology , Cell Survival/drug effects , Cetuximab/pharmacology , Complementarity Determining Regions/immunology , ErbB Receptors/immunology , ErbB Receptors/antagonists & inhibitors , HEK293 Cells , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Lung Neoplasms/immunology , Metformin/pharmacology , Single-Chain Antibodies/pharmacology , Single-Chain Antibodies/immunologyABSTRACT
BACKGROUND/AIM: One of the hallmarks of cancer is deregulation of multiple signaling pathways, which can lead to uncontrolled proliferation and migration of cells. Over-expression and mutations in human epidermal growth factor receptor 2 (HER2) can lead to overactivation of these pathways, potentially developing cancer in different tissues, including breast tissue. IGF-1R and ITGB-1 are two receptors that have been linked to cancer development. Therefore, the aim of this study was to investigate the effects of silencing of the corresponding genes using specific siRNAs. MATERIALS AND METHODS: Transient silencing of HER2, ITGB-1, and IGF-1R was conducted using siRNAs and expression was quantified by reverse transcription-quantitative polymerase chain reaction. Viability in human breast cancer cells SKBR3, MCF-7, and HCC1954 and cytotoxicity in HeLa cells were tested using WST-1 assay. RESULTS: The use of anti-HER2 siRNAs in a breast cancer cell line over-expressing HER2 (SKBR3) led to a decrease in cell viability. However, silencing of ITGB-1 and IGF-1R in the same cell line had no significant effects. Silencing of any of the genes encoding any of the three receptors in MCF-7, HCC1954, and HeLa had no significant effects. CONCLUSION: Our results provide evidence towards using siRNAs against HER2-positive breast cancer. Silencing of ITGB-1 and IGF-R1 did not significantly inhibit the growth of SKBR3 cells. Therefore, there is need for testing the effect of silencing ITGB-1 and IGF-R1 in other cancer cell lines over-expressing these biomarkers and explore their potential use in cancer therapy.
