Sinularin stabilizes FOXO3 protein to trigger prostate cancer cell intrinsic apoptosis

Sinularin, a natural product that purified from soft coral, exhibits anti-tumor effects against various human cancers. However, the mechanisms are not well understood. In this study, we demonstrated that Sinularin inhibited the viability of human prostate cancer cells in a dose-dependent manner and displayed significant cytotoxicity only at high concentration against normal prostate epithelial cell RWPE-1. Flow cytometry assay demonstrated that Sinularin induced tumor cell apoptosis. Further investigations revealed that Sinularin exerted anti-tumor activity through intrinsic apoptotic pathway along with up-regulation of pro-apoptotic protein Bax and PUMA, inhibition of anti-apoptotic protein Bcl-2, mitochondrial membrane potential collapses, and release of mitochondrial proteins. Furthermore, we illustrated that Sinularin induced cell apoptosis via up-regulating PUMA through inhibition of FOXO3 degradation by the ubiquitin-proteasome pathway. To explore how Sinularin suppress FOXO3 ubiquitin-proteasome degradation, we tested two important protein kinases AKT and ERK that regulate FOXO3 stabilization. The results revealed that Sinularin stabilized and up-regulated FOXO3 via inhibition of AKT- and ERK1/2-mediated FOXO3 phosphorylation and subsequent ubiquitin-proteasome degradation. Our findings illustrated the potential mechanisms by which Sinularin induced cell apoptosis and Sinularin may be applied as a therapeutic agent for human prostate cancer.

Promotion Effect of Coexposure to a High-Fat Diet and Nano-Diethylnitrosamine on the Progression of Fatty Liver Malignant Transformation into Liver Cancer

Overconsumption of high-fat foods increases the risk of fatty liver disease (FLD) and liver cancer with long pathogenic cycles. It is also known that the intake of the chemical poison nitrosamine and its nanopreparations can promote the development of liver injuries, such as FLD, and hepatic fibrosis, and significantly shorten the formation time of the liver cancer cycle. The present work confirmed that the coexposure of a high-fat diet (HFD) and nano-diethylnitrosamine (nano-DEN) altered the tumor microenvironment and studied the effect of this coexposure on the progression of fatty liver malignant transformation into liver cancer. Gene transcriptomics and immunostaining were used to evaluate the tumor promotion effect of the coexposure in mice. After coexposure treatment, tumor nodules were obviously increased, and inflammation levels were elevated. The liver transcriptomics analysis showed that the expression levels of inflammatory, fatty, and fibrosis-related factors in the coexposed group were increased in comparison with the nano-DEN- and high-fat-alone groups. The Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that coexposure aggravated the high expression of genes related to the carcinomatous pathway and accelerated the formation of the tumor microenvironment. The immunohistochemical staining results showed that the coexposure significantly increased the abnormal changes in proteins related to inflammation, proliferation, aging, and hypoxia in mouse liver tissues. The coexposure of high fat and nano-DEN aggravated the process of steatosis and carcinogenesis. In conclusion, the habitual consumption of pickled foods containing nitrosamines in a daily HFD significantly increases the risk of liver pathology lesions progressing from FLD to liver cancer.

Research Advances in the Roles of Circular RNAs in Pathophysiology and Early Diagnosis of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) refers to different degrees of glucose tolerance abnormalities that occur during pregnancy or are discovered for the first time, which can have a serious impact on the mother and the offspring. The screening of GDM mainly relies on the oral glucose tolerance test (OGTT) at 24–28 weeks of gestation. The early diagnosis and intervention of GDM can greatly improve adverse pregnancy outcomes. However, molecular markers for early prediction and diagnosis of GDM are currently lacking. Therefore, looking for GDM-specific early diagnostic markers has important clinical significance for the prevention and treatment of GDM and the management of subsequent maternal health. Circular RNA (circRNA) is a new type of non-coding RNA. Recent studies have found that circRNAs were involved in the occurrence and development of malignant tumors, metabolic diseases, cardiovascular and cerebrovascular diseases, etc., and could be used as the molecular marker for early diagnosis. Our previous research showed that circRNAs are differentially expressed in serum of GDM pregnant women in the second and third trimester, placental tissues during cesarean delivery, and cord blood. However, the mechanism of circular RNA in GDM still remains unclear. This article focuses on related circRNAs involved in insulin resistance and β-cell dysfunction, speculating on the possible role of circRNAs in the pathophysiology of GDM under the current research context, and has the potential to serve as early molecular markers for the diagnosis of GDM.

Modified Predictive Model and Nomogram by Incorporating Prebiopsy Biparametric Magnetic Resonance Imaging With Clinical Indicators for Prostate Biopsy Decision Making

Purpose

The purpose of this study is to explore the value of combining bpMRI and clinical indicators in the diagnosis of clinically significant prostate cancer (csPCa), and developing a prediction model and Nomogram to guide clinical decision-making.

Methods

We retrospectively analyzed 530 patients who underwent prostate biopsy due to elevated serum prostate specific antigen (PSA) levels and/or suspicious digital rectal examination (DRE). Enrolled patients were randomly assigned to the training group (n = 371, 70%) and validation group (n = 159, 30%). All patients underwent prostate bpMRI examination, and T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) sequences were collected before biopsy and were scored, which were respectively named T2WI score and DWI score according to Prostate Imaging Reporting and Data System version 2 (PI-RADS v.2) scoring protocol, and then PI-RADS scoring was performed. We defined a new bpMRI-based parameter named Total score (Total score = T2WI score + DWI score). PI-RADS score and Total score were separately included in the multivariate analysis of the training group to determine independent predictors for csPCa and establish prediction models. Then, prediction models and clinical indicators were compared by analyzing the area under the curve (AUC) and decision curves. A Nomogram for predicting csPCa was established using data from the training group.

Results

In the training group, 160 (43.1%) patients had prostate cancer (PCa), including 128 (34.5%) with csPCa. Multivariate regression analysis showed that the PI-RADS score, Total score, f/tPSA, and PSA density (PSAD) were independent predictors of csPCa. The prediction model that was defined by Total score, f/tPSA, and PSAD had the highest discriminatory power of csPCa (AUC = 0.931), and the diagnostic sensitivity and specificity were 85.1% and 87.5%, respectively. Decision curve analysis (DCA) showed that the prediction model achieved an optimal overall net benefit in both the training group and the validation group. In addition, the Nomogram predicted csPCa revealed good estimation when compared with clinical indicators.

Conclusion

The prediction model and Nomogram based on bpMRI and clinical indicators exhibit a satisfactory predictive value and improved risk stratification for csPCa, which could be used for clinical biopsy decision-making.

Survey on antibiotic sensitivity of Neisseria gonorrhoeae strains isolated in China, 1987-1992

BACKGROUND AND OBJECTIVE

The appearance and the endemic of penicillinase-producing Neisseria gonorrhoeae (PPNG) and other resistant strains cause much difficulty in the treatment of gonorrhea. To keep surveillance of the strains is important for the control of gonorrhea nationwide.

GOAL OF THIS STUDY

To know the resistance to antibiotics of Neisseria gonorrhoeae strains isolated in China.

STUDY DESIGN

The minimum inhibitory concentration (MIC) to penicillin, spectinomycin, and cephalosporins was determined by the agar plate dilution test in strains of N. gonorrhoeae submitted from six cities in various areas of the country during the period 1987-1992, and the prevalence of penicillinase-producing N. gonorrhoeae strains were examined by the rapid idometric method.

RESULTS

The resistant strains to penicillin (MIC > or = 1.0 microgram/ml) accounted for 57.5% of all isolates. The resistant strains to spectinomycin (MIC > or = 128 micrograms/ml) made up 1.3% and the strains which had a MIC closing resistance (MIC = 64 micrograms/ml) accounted for 4%. There were 18 PPNG strains (4.3%) in 419 isolates from Nanjing and Nanning city. The resistant strains to ceftrixone and cefotaxime accounted for 2.6% and 4.2%, respectively.

CONCLUSION

The situation of N. gonorrhoeae resistance to penicillin is rather serious in the country and relevant measures should be taken in the choice of therapeutic drugs, the follow-up of patients and the surveillance of gonorrhea.

Preliminary observations on experimental leprosy in tupaias (Tupaia belangeri yunalis)

The Tupaia belangeri yunalis (tree shrew) is one of the primitive primates. They were inoculated subcutaneously in the footpad or intravenously with Mycobacterium leprae from a patient with multibacillary leprosy. As controls, the footpads of CFW mice were inoculated with the same suspension of M. leprae. The results showed growth of acid-fast bacilli (AFB) in the footpads of locally inoculated CFW mice and in the footpads of both locally and intravenously inoculated tupaias. Whereas the numbers of AFB declined in the footpads of CFW mice after 12 months, they increased in the tupaia footpads, up to 2.44 x 19(9) AFB/g of tissue. The footpads of one tupaia were swollen, which on section revealed a granulomatous infiltration, including foamy and heavily infected macrophages. M. leprae were also seen in the branches of cutaneous nerves. Also AFB occurred in some viscera. Preliminary studies indicate that the AFB multiplying in tupaias are M. leprae.

Structures of the promoter and operator of the glpD gene encoding aerobic sn-glycerol-3-phosphate dehydrogenase of Escherichia coli K-12

The nucleotide sequence of a 690-base-pair DNA segment containing the control region for the glpD gene encoding aerobic sn-glycerol-3-phosphate dehydrogenase was determined. An ATG translation initiation codon with an adjacent ribosome-binding site was found which preceded an open reading frame continuing 61 codons to the end of the DNA that was sequenced. The start site for transcription, identified by using primer extension analysis, was located 42 base pairs upstream from the proposed Met start codon. The transcription start site was preceded by a region containing typical -10 and -35 sequences found in bacterial promoters. A binding site for the cyclic AMP-cyclic AMP receptor protein complex (identified by comparison with the consensus-binding sequence and verified by using DNase I footprinting) was located just upstream from the -35 sequence, centered at position -63. The interaction site for the glp repressor was identified by using DNase I footprinting. It consisted of a 49-base-pair region which started at the -10 sequence and continued to position +38. This region contained two directly repeated sequences, each possessing hyphenated dyad symmetry, which suggests that the operator is tandemly repeated. The presence of two adjacent operators may explain why expression of the glpD gene is the most sensitive to repressor when compared with expression of the other operons that are members of the glp regulon.

Purification and characterization of the repressor for the sn-glycerol 3-phosphate regulon of Escherichia coli K12

The glpR gene encoding the repressor for the sn-glycerol 3-phosphate regulon of Escherichia coli was cloned downstream from the strong pL promoter of bacteriophage lambda. This allowed overproduction of the repressor upon thermal induction of a cryptic lambda lysogen harboring the cI857 gene. The repressor was purified 40-fold to homogeneity from an induced strain. The purification scheme utilized polyethyleneimine and ammonium sulfate fractionation, followed by phosphocellulose and DEAE-Sephadex chromatography. Purification was monitored by measuring the binding of radiolabeled inducer (sn-glycerol 3-phosphate) to the repressor. The purified repressor migrated as a single band exhibiting a subunit molecular weight of 30,000 assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weight of the repressor under nondenaturing conditions was 100,000-130,000 suggesting the repressor is a tetramer under native conditions. Interaction of the repressor with sn-glycerol 3-phosphate was studied using flow dialysis. Scatchard analysis of the data indicated four binding sites/repressor tetramer and a dissociation constant of 31 microM. Interaction of the repressor with DNA was studied using band-shift electrophoresis. The repressor specifically bound DNA fragments containing the control regions for the glpD, glpK, and glpT-A genes. Binding of DNA by the repressor was diminished in the presence of sn-glycerol 3-phosphate.

Comparison of the immunogenicity of vaccines prepared from viable Mycobacterium bovis BCG, heat-killed Mycobacterium leprae, and a mixture of the two for normal and M. leprae-tolerant mice

Intradermal vaccines consisting of viable Mycobacterium bovis BCG, heat-killed Mycobacterium leprae, or mixtures of the two were titrated in mice in doses of 10(5.2), 10(5.8), 10(6.4), 10(7.0), and 10(7.6) acid-fast bacilli. The immune response was measured by sensitization (48 to 72 h foot pad enlargement on challenge with 10(7.0) heat-killed M. leprae) and by protection against infection with a viable M. leprae challenge. There was increasing response with increasing dose of vaccine, and overall the responses to the three vaccines were similar. At the lowest dose, however, the combination of BCG and M. leprae gave superior protection. The local reaction to the vaccines in the lower dose range was less severe with the M. leprae vaccine. In another experiment, the three vaccines were compared in normal mice and in mice that had been rendered tolerant by intravenous injection of M. leprae. The tolerant mice developed no measurable sensitization on vaccination with M. leprae, but they developed partial but distinct sensitization on vaccination with BCG, alone or in combination with M. leprae. The tolerant mice developed little or no protection with any of the vaccines, however.

Sensitization or tolerance to Mycobacterium leprae antigen by route of injection

Aqueous suspensions of heat-killed Mycobacterium leprae in a dose of 10(7) organisms were highly immunogenic when injected intradermally (i.d.). The same dose of bacteria did not sensitize when given intraperitoneally (i.p.) or intravenously (i.v.), and did so only minimally at best when given subcutaneously. The i.d. route was the most immunogenic for sheep erythrocytes also. M. leprae injected i.p. or i.v. stimulated immune tolerance to M. leprae challenge i.d. In older mice (greater than or equal to 8 weeks), the i.v. injections gave more complete tolerance. Mice that had been rendered tolerant by i.v. injections maintained their tolerance for at least 168 days. Prior UV irradiation of intact mice prevented sensitization by the i.d. route. In normal mice, living M. bovis BCG given i.d. produced good sensitization to M. leprae. Mice that had been made tolerant by i.v. injection of M. leprae could be partially sensitized to M. leprae by i.d. immunization with BCG; mixtures of living BCG and heat-killed M. leprae were no more effective than BCG alone. These findings appear to have relevance to the pathogenesis of lepromatous leprosy and its immunoprophylaxis.