Platinum(II) Complex-Nuclear Localization Sequence Peptide Hybrid for Overcoming Platinum Resistance in Cancer Therapy

Platinum therapy represents the first line of treatment in many malignancies but its high systemic toxicity limits the therapeutic dosage. Herein, we report the synthesis of carboplatin-like complexes with azide and alkyne functional groups and the formation of a platinum (II)-nuclear localization sequence peptide (Pt-NLS) hybrid to improve the import of platinum (II) complexes directly into the cell’s nucleus. The Pt-NLS hybrid successfully enters cells and their nuclei, forming Pt-induced nuclear lesions. The in vitro efficacy of Pt-NLS is high, superior to native carboplatin at the same concentration. The methodology used is simple and cost-effective and most importantly can easily be extended to load the Pt (II) onto other supports, opening new possibilities for enhanced delivery of Pt (II) therapy

Tripeptide-Stabilized Oil-in-Water Nanoemulsion of an Oleic Acids–Platinum(II) Conjugate as an Anticancer Nanomedicine

We report a nanoemulsion (NE) which is stabilized by self-assembling tripeptide lysine-tyrosine-phenylalanine (KYF) and encapsulates an oleic acids–platinum conjugate formed using simple Pt (II) coordination chemistry. The KYF-Pt-NE is evaluated both in cultured ovarian cancer cells and in an in vivo preclinical cancer model and shows pH dependent Pt (II) release, which is low at physiological pH and enhanced at tumoral pH. The biological activity of KYF-Pt-NE, evaluated in multiple ovarian cancer cell lines, is significantly higher when compared to the analogous Pt (II) complex used in the clinic. Concurrently, the KYF-Pt-NE platform shows good compatibility with the immune system. Preliminary in vivo testing of KYF-Pt-NE with tumor bearing mice indicates efficient Pt (II) delivery to the tumor. Together, these results demonstrate the potential of peptide-stabilized nanoemulsions, specifically KYF-Pt-NE as an effective nanomedicine against cancer

Cellular cytotoxicity and <i>P. aeruginosa</i> adhesion and invasion in response to simvastatin treatment.

<p>Cells were treated with 10 µM simvastatin for 24 hours (<b>A, B, C</b>), following which they were infected with <i>P. aeruginosa</i> PAO1at MOI 50∶1 (<b>A, C</b>). (<b>A</b>) Simvastatin significantly induced cytotoxicity but did not alter <i>P. aeruginosa</i>-mediated LDH release at 6 hours post infection. (<b>B</b>) Simvastatin-induced cytotoxicity was not significantly altered in si-wtKLF6 knockdown cells demonstrating wtKLF6 was not implicated in simvastatin-mediated cytotoxicity of lung epithelial cells. (<b>C</b>) Simvastatin treatment increased <i>P. aeruginosa</i> adhesion to cells, but (<b>D</b>) did not influence invasion at 3 hours of infection. *<i>P</i>, ≤0.05, **<i>P</i>, ≤0.01, *** <i>P</i>, ≤0.001.</p

A model for the findings observed in this study.

<p>(<b>A</b>) In this work, wtKLF6 was found to regulate the expression of ASAH1, CCL20 and iNOS in lung cells in the absence of simvastatin (SIM).(<b>B</b>) SIM may induce KLF2 and KLF6 splice variant expression by binding to promoter elements and inhibition of Rho and Ras GTPase signalling. Rho and Ras GTPase signalling are also attenuated by the T3SS of <i>P. aeruginosa</i>, which may account for the induction of KLF2 and KLF6 by this species. The mechanism by which SIM induces IL-8 is unclear. However, the synergistic effect observed on CCL20 in this study may be a result of increased bacterial adhesion by SIM, and induction via wtKLF6. In addition, the wtKLF6-dependent reduction of iNOS by SIM may potentially be responsible for the observed increase in bacterial adhesion, Broken arrows represent mechanisms which require further elucidation.</p

Statin treatment and <i>P. aeruginosa</i> infection modulate the host immune response.

<p>A549 cells were treated with 10 µM simvastatin or an equivalent amount of DMSO (VEHICLE) for 24 hours. Untreated and statin-treated cells were subsequently infected with <i>P. aeruginosa</i> PAO1 for 3 hours at MOI 50∶1. The expression of (<b>A</b>) KLF2 (<b>B</b>) KLF6 (<b>C</b>) IL-8 (<b>D</b>) CCL20 and (<b>E</b>) TLR5 was analysed in uninfected cells, and in the presence of vehicle, simvastatin (SIM), <i>P. aeruginosa</i> (PAO1) and simvastatin and PAO1 combined (SIM+PAO1). *<i>P</i>, ≤0.05, **<i>P</i>, ≤0.01, ***<i>P</i>, ≤0.001.</p

Primers used for qRT-PCR analysis of host gene expression.

<p><b>* Roche Universal ProbeLibrary (UPL) Probe Number</b>.</p><p>The annealing temperature of all primer sets is 60°C.</p

Cells and bacteria used in this study.

<p>Cells and bacteria used in this study.</p

Summary of mutation allele fractions across patient samples by each mutated gene.

<p>Correlation between the total mutations/gene showed <i>R</i>² = 0.92 (Pearson correlation coefficient) when compared between cell pellet DNA and cfDNA.</p

Baseline characteristics and pre- and post-hysteroscopy diagnoses of the patient cohort.

<p>Baseline characteristics and pre- and post-hysteroscopy diagnoses of the patient cohort.</p

Clinicopathologic correlates of the seven cancer cases diagnosed by histopathology within the patient cohort.

<p>Clinicopathologic correlates of the seven cancer cases diagnosed by histopathology within the patient cohort.</p