Lipid-oligonucleotide conjugates improve cellular uptake and efficiency of TCTP-antisense in castration-resistant prostate cancer

Abstract

Translationally controlled tumor protein (TCTP) has been implicated in a plethora of important cellular processes related to cell growth, cell cycle progression, malignant transformation and inhibition of apoptosis. Therefore, TCTP is now recognized as a potential therapeutic target in several cancers including prostate, breast and lung cancers. We previously showed that TCTP is overexpressed in castration-resistant prostate cancer (CRPC), and it has been implicated resistance to treatment. Recently, we developed TCTP antisense oligonucleotides (ASOs) to inhibit TCTP expression. However, the intracellular delivery and silencing activity of these oligonucleotides remains a challenge, and depend on the use of transfection agents and delivery systems. Here we show that lipid-modified ASO (LASOs) has improved penetration and efficiency in inhibiting TCTP expression in the absence of additional transfection agents, both in vitro and in vivo. Transfection with TCTP-LASO led to rapid and prolonged internalization via macropinocytosis, TCTP downregulation and significant decreased cell viability. We also show that lipid-modification led to delayed tumor progression in CRPC xenografts models, with no significant toxic effects observed.

Lipid oligonucleotides as a new strategy for tackling the antibiotic resistance

“…It was demonstrated that the resulting nanocarriers displayed higher biological activities compared to the unformulated drugs. We also investigated the impact of the direct lipid conjugation to oligonucleotides 34 (anti miRNA 35 or antisenses 24 ) on their activity and/or delivery in eukaryotic cells. In all cases, it was found that lipid conjugation was able to improve the delivery and activity in eukaryotic cancer cells.…”

“…Also, to monitor the localization a Cyanine-5 fluorescent dye was coupled to the 3′ extremity of ON/LON α-Cy5 . ON/LON β was tested as it was shown not to have any effect on mammalian cells 24 while presenting a partial alignment with target mRNA. ON/LON γ and ON/LON δ were designed by broadening the specific binding zone between ON/LON α and ON/ LON β with bla CTX-M-15 gene.…”

“…physicochemical characterization of micelles. Expectedly, while ONs remain in aqueous solution without specific self-organization (no significant population of objects in water by DLS), LON amphiphiles organize themselves in micelles and larger objects 24,28,29 . The mean size of micellar population of different sequences measured by Dynamic Light Scattering (DLS) in extracellular salt conditions (145 mM Na + and 5 mM K + ) ranged around 10 nm (Supplementary Table 1), independently on the oligonucleotide sequence, with negative zeta potential (−24 to −37 mV for 5 µM and 30 µM aqueous concentration respectively), as expected regarding polyanion structure of oligonucleotides.…”

“…However, despite their high potential, the cellular uptake of oligonucleotides remains one of the key steps for eliciting their biological activity, as the targeted mRNAs are located inside the cells 21,23 . Recently, we demonstrated that Lipid-oligonucleotide conjugates improve cellular uptake and efficiency of antisense in eukaryotic prostate cancer cells 24 . In the context of AMR, the cellular uptake of ONs inside prokaryotic cells is a critical issue 25 .…”

The 22Rv1 prostate cancer cell line carries mixed genetic ancestry: Implications for prostate cancer health disparities research using pre‐clinical models

“…Given the inherent difficulties in conducting mechanistic studies in primary PCa cells, including transfection issues and high degree of molecular variability as these primary cells propagate in vitro, [28][29][30][31] it is essential to have available a well-characterized, racially diverse, patient-derived cohort of immortalized cell lines representing different stages of PCa. Unfortunately, there is currently a lack of racial diversity in the human PCa cell lines that are commercially available for research.…”