His-tagged pro-apoptotic peptides: enhancing cell internalization and anticancer effect in vitro

Area of Science:

• Oncology
• Molecular Biology
• Drug Delivery

Background:

• Epidermal growth factor receptor (EGFR) overexpression in solid tumors correlates with poor prognosis and treatment resistance.
• Overcoming drug resistance in EGFR-positive cancers remains a significant clinical challenge.
• Tumor-homing cell-penetrating peptides offer potential for targeted cancer therapy and improved drug delivery.

Purpose of the Study:

• To evaluate the anticancer potential of EGFR-targeted pro-apoptotic peptides (NRPD-KLAK-H, NRPD-CTMP4-H) and compare them with free His-tagged peptides (NRPD-H, KLAK-H, CTMP4-H).
• To investigate the role of His-tag modification in enhancing peptide internalization and overcoming drug resistance in EGFR-positive cancers.

Main Methods:

• MTT assays were used to determine cell viability and inhibitory concentrations (IC50).
• TUNEL assays were employed to assess apoptosis induction.
• Immunofluorescence microscopy was utilized to visualize and quantify peptide internalization into cancer cells.

Main Results:

• KLAK-H and NRPD-KLAK-H demonstrated significant anticancer effects, inhibiting A-549 cell growth with IC50 values of 33.3 µM and 40.9 µM, respectively.
• Apoptosis was induced by KLAK-H and NRPD-KLAK-H, as indicated by TUNEL assays.
• His-tag modification improved peptide internalization, with KLAK-H/NRPD-KLAK-H showing better uptake than CTMP4-H/NRPD-CTMP4-H.

Conclusions:

• His-tagged pro-apoptotic peptides, especially KLAK-H, show promise as potential cancer therapeutics due to enhanced cellular uptake and apoptosis induction.
• While EGFR-targeted peptides did not achieve the expected outcomes, His-tag modification is a viable strategy to improve the efficacy of pro-apoptotic peptides in cancer treatment.