Development of nanoparticulate drug delivery systems for anti-metastic Ran GTPase therapeutics

Abstract

Metastasis is one of the key reasons for the high mortality rate among cancer patients which needs to be addressed if cancer treatment outcomes are to be improved. Various determinants, such as genetic factors, may be responsible for metastasis of cancer cells. For instance, overexpression of the RAN gene has been shown to cause metastasis in breast and lung cancer cells. The overexpression of certain metastasis-causing genes can be inhibited by silencing the expression of a target genes using RNA interference technology. RNA interference is a post transcriptional gene silencing process where mRNA of the gene of interest is targeted using small oligonucleotide sequences, such as shRNA, which binds to the target gene sequence and destroys its expression. However, delivery of shRNA alone is not recommended due to its high instability. Therefore, a carrier is needed which can protect and deliver such agents to the target site, which enhances therapeutic ability. Nanoparticles have proven to be an effective carrier of active agents in drug delivery. Herein, we developed nanoparticulate drug delivery systems for anti-metastatic Ran-GTPase/RAN therapeutics. Poly(lactic-co-glycolic acid) or PLGA and Poly(lactic-co-glycolic acid)- Poly(ethylene gycol) or PLGA-PEG-based nanoparticles were fabricated to encapsulate shRNA-1, shRNA4, N-{3-[(pyridine-4-yl) carbamoyl] phenyl thiophene-2-carboxamide (PCPTC) and curcumin and delivered inside MDA-MB231 breast cancer cells and A549 lung cancer cells to study their anti-metastatic effects in these cell lines. shRNAs effectively inhibited metastasis of breast and lung cancer cells which was confirmed by the results of various in vitro studies, such as cell viability, wound scratch assay and cell invasion studies. The cause of this anti-metastatic activity was due to the silencing of the RAN gene by shRNAs which was confirmed by qRt-PCR studies. PCPTC and curcumin were also delivered to cancer cells using PLGA and PLGA-PEG nanoparticles. PCPTC and curcumin inhibited metastasis of the cancer cells by affecting the Ran cycle responsible for metastasis of the model cancer cells. Therefore, various anti-metastatic agents were delivered to cancer cells using nanoparticles which stopped metastasis of the cancer cells either by silencing RAN gene/ Ran GTPase or affecting the Ran cycle. The data in this thesis support the viability of the RAN/Ran GTPase and Ran cycle as potential therapeutic targets that can arrest metastasis in breast and lung cancer cells.

Date of Award	2026
Original language	English
Supervisor	Susan Hawthorne (Supervisor), Paul McCarron (Supervisor), Mohamed El-Tanani (Supervisor) & Ahmed Faheem (Supervisor)