p16 promoter hypermethylation:A useful serum marker for early detection of gastric cancer

AIM： TO determine p15 promoter hypermethylation in gastric tumoral tissue and serum samples, its impact on p16-protein expression, and correlation with clinical and histological features. METHODS： Samples were obtained from 52 histologically confirmed cases of gastric adenocarcinoma. Gastric tissue and serum of 50 age- and sex-matched individuals with normal gastroscopy and biopsy were obtained as control samples. Methylation-specific polymerase chain reaction （MSP） was used to evaluate methylation status of p16 promoter, p16-protein expression was analyzed by immunohistochemical staining on paraffin-embedded sections. RESULTS： Methylation was detected in 44.2% （23/52） of tumoral tissues. 60.9% of them were also methylated in serum, i.e., 26.9% of all patients （14/52）. Methylation was not detected in tissue and sera of control samples. p16-protein expression was decreased in 61.5% of cases （32/52）, and was significantly associated with promoter hypermethylation （P 〈 0.001）. Methylation was significantly more frequent in higher pathological grades （P 〈 0.05）. Methylation was not associated with other clinicopathological features and environmental factors including Hpylori infection and smoking. CONCLUSION： p16 promoter hypermethylation is an important event in gastric carcinogenesis. It is the principle mechanism of p16 gene silencing. It is related to malignant tumor behavior. Detection of DNA methylation in serum may be a biomarker for early detection of gastric cancer.

IL13Rα1 prevents a castration resistant phenotype of prostate cancer by targeting hexokinase 2 for ubiquitin-mediated degradation

Objective:Androgen deprivation therapy(ADT)is still the principal treatment option for prostate cancer(PCa).In addition to reactivation of androgen receptor signaling,the resistance of PCa to apoptosis during ADT also contributes to castration resistant PCa(CRPC).A previous study reported that gene transfer of IL-13Rα2 into PCa cells sensitized the cells to the IL-13R-targeted cytotoxin IL13Rα1,leading to apoptosis.Compared with IL-13Rα2,IL13Rα1 is more constitutively expressed in PCa cells,but its function in PCa remains to be established.Methods:We determined the role and expression of IL13Rα1 in PCa cancer cells using western blotting,flow cytometry,and cell proliferation assays.Co-immunoprecipitation and mass spectrometry were used to identify the proteins that interacted with IL13Rα1,to elucidate its function.Results:In this study,we showed that IL13Rα1 was selectively suppressed in androgen-deprived PCa cells and that its suppression tended to be associated with poor prognoses of PCa patients.IL13Rα1 overexpression promoted apoptosis and inhibited tumor growth under androgen-deprived or castrated conditions(P<0.01).Mechanistically,IL13Rα1 recruited and facilitated ubiquitin protein ligase E3C-mediated ubiquitination and degradation of hexokinase 2(HK2),resulting in glycolytic inhibition and eventually leading to PCa cell apoptosis.Furthermore,our data revealed that mutated ataxia-telangiectasia kinase phosphorylated and facilitated the selective ubiquitin proteasome-mediated degradation of HK2.Notably,IL13Rα1-overexpressing PCa cells were more susceptible to apoptosis and exhibited reduced tumor growth after exposure to the HK2 inhibitor,2-deoxy-D-glucose(P<0.01).Conclusions:Our data identified a tumor suppressor role for IL13Rα1 in preventing the resistance of PCa cells to apoptosis during androgen deprivation by inhibiting glycolysis.IL13Rα1-mediated signaling involving HK2 may therefore provide a novel treatment target and strategy for CRPC.

Entinostat,a classⅠselective histone deacetylase inhibitor,plus exemestane for Chinese patients with hormone receptor-positive advanced breast cancer:A multicenter,randomized,double-blind,placebo-controlled,phase 3 trial

Entinostat plus exemestane in hormone receptor-positive(HR+)advanced breast cancer(ABC)previously showed encouraging outcomes.This multicenter phase 3 trial evaluated the efficacy and safety of entinostat plus exemestane in Chinese patients with HR+ABC that relapsed/progressed after≥1 endocrine therapy.Patients were randomized(2:1)to oral exemestane 25 mg/day plus entinostat(n=235)or placebo(n=119)5 mg/week in 28-day cycles.The primary endpoint was the independent radiographic committee(IRC)-assessed progression-free survival(PFS).The median age was 52(range,28—75)years and 222(62.7%)patients were postmenopausal.CDK4/6 inhibitors and fulvestrant were previously used in 23(6.5%)and 92(26.0%)patients,respectively.The baseline characteristics were comparable between the entinostat and placebo groups.The median PFS was 6.32(95%CI,5.30—9.11)and 3.72(95%CI,1.91—5.49)months in the entinostat and placebo groups(HR,0.76;95%CI,0.58—0.98;P=0.046),respectively.Grade≥3 adverse events(AEs)occurred in 154(65.5%)patients in the entinostat group versus 23(19.3%)in the placebo group,and the most common grade≥3 treatment-related AEs were neutropenia[103(43.8%)],thrombocytopenia[20(8.5%)],and leucopenia[15(6.4%)].Entinostat plus exemestane significantly improved PFS compared with exemestane,with generally manageable toxicities in HR+ABC(ClinicalTrials.gov#NCT03538171).

Excipient-free porphyrin/SN-38 based nanotheranostics for drug delivery and cell imaging

Nanotheranostics with comprehensive diagnostic and therapeutic capabilities show exciting cancer treatment potentials.Here,we develop an excipient-free drug delivery system for cancer diagnosis as well as therapy,in which a near infra-red photosensitizer and a chemotherapeutic drug can be self-delivered without any carriers.The building block of the drug delivery system was synthesized by covalently conjugating four anticancer drugs(7-ethyl-10-hydroxy-camptothecin,SN-38)with a photosensitizer(porphyrin)via hydrolyzable ester linkage,which endows the drug delivery system with 100%active pharmaceutical ingredients,excellent imaging,and therapeutic functionalities.The conjugates can readily self-assemble into nanosheets(PS NSs)and remain stable for at least 20 days in aqueous solution.In PS NSs,fluorescence resonance energy transfer(FRET)dominates the fluorescence of SN-38 and enables to monitor the drug release fluorescentiy.The PS NSs also show excellent anticancer activity in vitro,due to the increased cell uptake with the synergistic effect of photodynamic therapy and chemotherapy.