Protein Kinase A-Mediated Effects of Protein Kinase C Partial Agonist 5-(Hydroxymethyl)Isophthalate 1a3 in Colorectal Cancer Cells

Colorectal cancer is the third most commonly occurring cancer in men and the second in women. The global burden of colorectal cancer is projected to increase to over 2 million new cases with over 1 million deaths within the next 10 years and there is a great need for new compounds with novel mechanisms of action. Our group has developed PKC modulating isophthalic acid derivatives that induce cytotoxicity towards human cervical and prostate cancer cell lines. In this study, we investigated the effects of 5-(hydroxymethyl)isophthalate 1a3 (HMI-1a3) on colorectal cancer cell lines (Caco2, Colo205 and HT29). HMI-1a3 inhibited cell proliferation, decreased cell viability and induced an apoptotic response in all studied cell lines. These effects, however, were independent of PKC. Using serine/threonine kinome profiling and pharmacological kinase inhibitors we identified activation of the cAMP/PKA pathway as a new mechanism-of-action for HMI-1a3-induced anti-cancer activity in colorectal cancer cell lines. Our current results strengthen the hypothesis for HMI-1a3 as a potential anti-cancer agent against various malignancies. Significance Statement Colorectal cancer (CRC) is a common solid organ malignancy. Here, we demonstrate that the protein kinase C (PKC) C1 domain-targeted isophthalatic acid derivative HMI-1a3 has anti-cancer activity on CRC cell lines independently of PKC. We identified protein kinase A (PKA) activation as a mechanism of HMI-1a3 induced anti-cancer effects. Our results reveal a new anti-cancer mechanism of action for the partial PKC agonist HMI-1a3 and thus provide new insights for the development of PKC and PKA modulators for cancer therapy.Peer reviewe

Iäkkäiden muistisairaudet tarvitsevat erikoisosaajia

On korkea aika varmistaa, että hyvinvointialueet sekä yliopistosairaalat saavat geriatrian yksiköt ja niihin riittävät resurssit.</p

Missing Selectivity of Targeted 4 beta-Phorbol Prodrugs Expected to be Potential Chemotherapeutics

Targeting cytotoxic 4 beta-phorbol esters toward cancer tissue was attempted by conjugating a 4 beta-pborbol derivative with substrates for the proteases prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) expressed in cancer tissue. The hydrophilic peptide moiety was hypothesized to prevent penetration of the prodrugs into cells and prevent interaction with PKC. Cleavage of the peptide in cancer tumors was envisioned to release lipophilic cytotoxins, which subsequently penetrate into cancer cells. The 4 beta-phorbol esters were prepared from 4 beta-phorbol isolated from Croton tiglium seeds, while the peptides were prepared by solid-phase synthesis. Cellular assays revealed activation of PKC by the prodrugs and efficient killing of both peptidase positive as well as peptidase negative cells. Consequently no selectivity for enzyme expressing cells was found.Peer reviewe

Ehkäise, tunnista ja hoida vanhuksen vajaaravitsemus

Vertaisarvioitu.• Vanhusten vajaaravitsemus on yleistä myös Suomessa. Se hankaloittaa merkittävästi lääketieteellistä hoitoa. • Vajaaravitsemusriskin tunnistaminen ja varhainen hoito säästävät terveyden- huollon kustannuksia. Vajaaravitun potilaan hoitaminen voi maksaa jopa kolme kertaa niin paljon kuin normaalissa ravitsemustilassa olevan. • Hyvä ravitsemustila tukee vanhusten toimintakykyä ja itsenäistä elämää. • Säännöllinen punnitseminen, vajaaravitsemuksen seulonta ja aktiivinen ravitsemushoito kuuluvat jokaisen ikäihmisen hoitopolkuun

Ehkäise, tunnista ja hoida vanhuksen vajaaravitsemus

publishedVersio

Ehkäise, tunnista ja hoida vanhuksen vajaaravitsemus

Vanhusten vajaaravitsemus on yleistä myös Suomessa. Se hankaloittaa merkittävästi lääketieteellistä hoitoa.Vajaaravitsemusriskin tunnistaminen ja varhainen hoito säästävät terveydenhuollon kustannuksia. Vajaaravitun potilaan hoitaminen voi maksaa jopa kolme kertaa niin paljon kuin normaalissa ravitsemustilassa olevan.Hyvä ravitsemustila tukee vanhusten toimintakykyä ja itsenäistä elämää.Säännöllinen punnitseminen, vajaaravitsemuksen seulonta ja aktiivinen ravitsemushoito kuuluvat jokaisen ikäihmisen hoitopolkuun.</p

Scaffold hopping from (5-hydroxymethyl) isophthalates to multisubstituted pyrimidines diminishes binding affinity to the C1 domain of protein kinase C

Protein kinase C (PKC) isoforms play a pivotal role in the regulation of numerous cellular functions, making them extensively studied and highly attractive drug targets. Utilizing the crystal structure of the PKC delta C1B domain, we have developed hydrophobic isophthalic acid derivatives that modify PKC functions by binding to the C1 domain of the enzyme. In the present study, we aimed to improve the drug-like properties of the isophthalic acid derivatives by increasing their solubility and enhancing the binding affinity. Here we describe the design and synthesis of a series of multisubstituted pyrimidines as analogs of C1 domain - targeted isophthalates and characterize their binding affinities to the PKC alpha isoform. In contrast to our computational predictions, the scaffold hopping from phenyl to pyrimidine core diminished the binding affinity. Although the novel pyrimidines did not establish improved binding affinity for PKC alpha compared to our previous isophthalic acid derivatives, the present results provide useful structure-activity relationship data for further development of ligands targeted to the C1 domain of PKC.Peer reviewe

3D chemographic plot of PKC-targeted compounds from two different angles.

<p>Color code: Pyrimidines are shown in green; HMIs in blue; bryostatins in red; phorbol esters in yellow; DAG-lactones in purple; iripallidal in black, ingenol 3-angelate and prostratin in orange; mezerein in cyan; 9-decyl-benzolactam-V8 and indolactam-V in magenta. Pyrimidines <b>1e</b> and <b>2a</b>, HMI-1a3 (towards the PC2-boundary) and HMI-1b11 (central area) are represented as cubes. The full list of the compounds, ChemGPS-NP raw data, SMILES and structures are available in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195668#pone.0195668.s001" target="_blank">S1 File</a>.</p

Comparison of phorbol 13-acetate, HMI-1a3, 2b and 1f docked into the PKC<i>δ</i>C1B domain (PDB: 1PTR).

<p>(A) Phorbol 13-acetate; (B) HMI-1a3; (C) <b>2b</b>; (D) <b>1f</b>. Color code: carbon atoms are shown in grey, oxygen atoms in red, nitrogen atoms in blue and fluorine atoms in lime. Hydrogen bonds are represented as cyan dashed lines. View from the top of the binding site.</p

Scaffolds comparison.

<p>Comparison of the HMI scaffold (left) with the symmetrical 2,4,6-trisubstituted pyrimidine (center) and the asymmetrical 2,4,5,6-tetrasubstituted pyrimidine (right) scaffolds. Common moieties are color-coded: H-bond donor/acceptor hydroxy groups are shown in blue, carbonyl H-bond acceptor oxygens in red and hydrophobic substituents R in green.</p