Design and development of a peptide-based adiponectin receptor agonist for cancer treatment

<p>Abstract</p> <p>Background</p> <p>Adiponectin, a fat tissue-derived adipokine, exhibits beneficial effects against insulin resistance, cardiovascular disease, inflammatory conditions, and cancer. Circulating adiponectin levels are decreased in obese individuals, and this feature correlates with increased risk of developing several metabolic, immunological and neoplastic diseases. Thus, pharmacological replacement of adiponectin might prove clinically beneficial, especially for the obese patient population. At present, adiponectin-based therapeutics are not available, partly due to yet unclear structure/function relationships of the cytokine and difficulties in converting the full size adiponectin protein into a viable drug.</p> <p>Results</p> <p>We aimed to generate adiponectin-based short peptide that can mimic adiponectin action and be suitable for preclinical and clinical development as a cancer therapeutic. Using a panel of 66 overlapping 10 amino acid-long peptides covering the entire adiponectin globular domain (residues 105-254), we identified the 149-166 region as the adiponectin active site. Three-dimensional modeling of the active site and functional screening of additional 330 peptide analogs covering this region resulted in the development of a lead peptidomimetic, ADP 355 (H-DAsn-Ile-Pro-Nva-Leu-Tyr-DSer-Phe-Ala-DSer-NH₂). In several adiponectin receptor-positive cancer cell lines, ADP 355 restricted proliferation in a dose-dependent manner at 100 nM-10 μM concentrations (exceeding the effects of 50 ng/mL globular adiponectin). Furthermore, ADP 355 modulated several key signaling pathways (AMPK, Akt, STAT3, ERK1/2) in an adiponectin-like manner. siRNA knockdown experiments suggested that ADP 355 effects can be transmitted through both adiponectin receptors, with a greater contribution of AdipoR1. <it>In vivo</it>, intraperitoneal administration of 1 mg/kg/day ADP 355 for 28 days suppressed the growth of orthotopic human breast cancer xenografts by ~31%. The peptide displayed excellent stability (at least 30 min) in mouse blood or serum and did not induce gross toxic effects at 5-50 mg/kg bolus doses in normal CBA/J mice.</p> <p>Conclusions</p> <p>ADP 355 is a first-in-class adiponectin receptor agonist. Its biological activity, superior stability in biological fluids as well as acceptable toxicity profile indicate that the peptidomimetic represents a true lead compound for pharmaceutical development to replace low adiponectin levels in cancer and other malignancies.</p

název v anglickém jazyce není uveden

Předložená práce přispěla к rozšíření představ o možné úloze vybraných adipocytokinů (adiponectinu a resistinu) v patogenezi karcinomu prostaty a některých revmatických kloubních onemocnění. Získané poznatky o imunohistochemické lokalizaci sledovaných adipocytokinů byly doplněny stanovením jejich sérových, resp. intraartikulárních hladin. Dále byl vyhodnocen i jejich vztah к ostatním antropometrickým, biochemickým a endokrinním parametrům. Podařilo se tak získat některé nové poznatky o úloze těchto molekul ve vybraných patologických stavech lidského organizmu a přinést doplňující údaje ke dříve publikovaným pracem. Powered by TCPDF (www.tcpdf.org)Adipocytokines are a group of adipose tissue-derived cytokines that have been discovered since early nineties. The role of selected adipocytokines in the prostate carcinoma and in selected joint diseases was evaluated. In the first part of this work the role of adiponectin and resistin in the prostate cancer development and progression was examined. Immunohistochemical expression and serum levels of these adipocytokines were evaluated in both groups of patients with benign prostate hyperplasia and prostate cancer of pathological grade pT2 and pT3, respectively. Moreover, selected metabolic, biochemical and anthropometric parameters were included into this study. Serum adiponectin levels did not differ between prostate benign hyperplasia and prostate cancer generally, but they were significantly higher in pT3 in comparison to pT2 group. In agreement with the results of serum levels, tissue immunohistochemistry showed enhanced staining intensity of adiponectin in neoplastic glands and to a lesser degree in prostatic intraepithelial neoplasia while within benign prostate hyperplasia the immunohistochemical staining was generally low. None relation of adiponectin expression to disease grade or stage was observed. In resistin no difference between benign hyperplasia and prostate cancer in respect to serum levels...Institute of Pathology First Faculty of Medicine Charles University in PragueÚstav patologie 1. LF UK a VFN v PrazeFirst Faculty of Medicine1. lékařská fakult

název v anglickém jazyce není uveden

Adipocytokines are a group of adipose tissue-derived cytokines that have been discovered since early nineties. The role of selected adipocytokines in the prostate carcinoma and in selected joint diseases was evaluated. In the first part of this work the role of adiponectin and resistin in the prostate cancer development and progression was examined. Immunohistochemical expression and serum levels of these adipocytokines were evaluated in both groups of patients with benign prostate hyperplasia and prostate cancer of pathological grade pT2 and pT3, respectively. Moreover, selected metabolic, biochemical and anthropometric parameters were included into this study. Serum adiponectin levels did not differ between prostate benign hyperplasia and prostate cancer generally, but they were significantly higher in pT3 in comparison to pT2 group. In agreement with the results of serum levels, tissue immunohistochemistry showed enhanced staining intensity of adiponectin in neoplastic glands and to a lesser degree in prostatic intraepithelial neoplasia while within benign prostate hyperplasia the immunohistochemical staining was generally low. None relation of adiponectin expression to disease grade or stage was observed. In resistin no difference between benign hyperplasia and prostate cancer in respect to serum levels..

The Progesterone Receptor Hinge Region Regulates the Kinetics of Transcriptional Responses Through Acetylation, Phosphorylation, and Nuclear Retention

Progesterone receptors (PRs) are critical regulators of mammary gland development and contributors to breast cancer progression. Posttranslational modifications of PR have been shown to alter hormone responsiveness. Site-directed mutagenesis demonstrated that upon hormone binding, PR is acetylated at the consensus sequence, KXKK (amino acids 638–641), located within the hinge region. We created an acetylation-deficient (K-A) mutant as well as acetylation mimics (K-Q or K-T). Interestingly, similar to K-A PR, PR acetylation mimics (K-Q or K-T) displayed delayed phosphorylation and nuclear entry relative to wild-type (wt) PR-B, indicative of disruption of PR nuclear-cytoplasmic shuttling. Wt PR-B, but not K-mutant PRs, induced c-myc at 1 h of progestin treatment. However, at 6 h of treatment, c-myc induction was comparable with levels induced by wt PR-B, suggesting that the precise timing of PR phosphorylation and nuclear retention are critical for cells to rapidly initiate robust transcriptional programs. In contrast to c-myc, progestin-induced serum- and glucocorticoid-regulated kinase (SGK) expression displayed sensitivity to PR acetylation but not nuclear entry. Namely, in the presence of progestin, acetylation-deficient (K-A) mutant PR-B up-regulated SGK mRNA relative to wt PR; progesterone response element-luciferase assays confirmed this result. However, K-Q and K-T acetylation mimics only weakly induced SGK expression independently of nuclear retention. These data reveal the ability of PR acetylation to alter the magnitude of transcriptional response at selected (slow response) promoters (SGK), whereas the hinge region dictates the kinetics of the transcriptional response to hormone at other (rapid response) promoters (c-myc). In sum, the PR hinge region is multifunctional. Understanding the ability of this region to couple acetylation, phosphorylation, and nuclear entry may provide clues to mechanisms of altered hormone responsiveness

Risk Factors for Primary Middle East Respiratory Syndrome Coronavirus Illness in Humans, Saudi Arabia, 2014

Risk factors for primary Middle East respiratory syndrome coronavirus (MERS-CoV) illness in humans are incompletely understood. We identified all primary MERS-CoV cases reported in Saudi Arabia during March–November 2014 by excluding those with history of exposure to other cases of MERS-CoV or acute respiratory illness of unknown cause or exposure to healthcare settings within 14 days before illness onset. Using a case–control design, we assessed differences in underlying medical conditions and environmental exposures among primary case-patients and 2–4 controls matched by age, sex, and neighborhood. Using multivariable analysis, we found that direct exposure to dromedary camels during the 2 weeks before illness onset, as well as diabetes mellitus, heart disease, and smoking, were each independently associated with MERS-CoV illness. Further investigation is needed to better understand animal-to-human transmission of MERS-CoV