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Marine biofouling has a major economic impact, especially when it occurs on ship hulls or aquaculture facilities. Since the International Maritime Organization (IMO) treaty to ban the application of organotin-based paints to ships went into effect in 2008, there is an urgent demand for the development of efficient and environmentally friendly antifouling agents. Marine microorganisms have proved to be a potential source of antifouling natural compounds. In this study, six dihydroquinolin-2-one-containing alkaloids, three monoterpenoids combined with a 4-phenyl-3,4-dihydroquinolin-2(1 H)-one ( 1- 3) and three 4-phenyl-3,4-dihydroquinolin-2(1 H)-one alkaloids ( 4- 6), were isolated from the gorgonian coral-derived fungus Scopulariopsis sp. collected in the South China Sea. These dihydroquinolin-2-one-containing alkaloids were evaluated against the larval settlement of barnacle Balanus amphitrite, and antifouling activity was detected for the first time for this class of metabolites. All of them except 6 showed strong antifouling activity. Compounds 1 and 2 were discovered to be the most promising non-toxic antilarval settlement candidates. Especially, compound 1 is the strongest antifouling compound in nature until now which showed highly potent activity with picomolar level (EC 17.5 pM) and a very safety and high therapeutic ratio (LC/EC 1200). This represents an effective non-toxic, anti-larval settlement structural class of promising antifouling lead compound. [ABSTRACT FROM AUTHOR]

Background: Low expression of E2F3a and caspase 8 associated protein 2 (CASP8AP2) are associated with poor prognosis of childhood acute lymphoblastic leukemia (ALL). Methods: Dual-luciferase reporter assay and wild type as well as four mutated types of reporter plasmids were used to demonstrate the activation of E2F3a on CASP8AP2 transcription. The direct binding of E2F3a with the promoter of CASP8AP2 was shown by Chromatin Immunoprecipitation (ChIP). Cell proliferation activity and cell cycle were determined by MTS and flow cytometry in leukemic cells after treating with common chemotherapeutic drugs vincristine and daunorubicin. Results: In this study, we found that up-regulation of E2F3a in leukemic cells led to increased fraction of cells in S and G2/M phase, accelerated proliferation, and enhanced sensitivity to vincristine and daunorubicin. ChIP and luciferase assay indicated that E2F3a could directly bind to two fragments in the wild type of CASP8AP2 promotor (− 206 to − 69 and − 677 to − 507), and activate its transcription activity which was reduced in mutated promotors. The effect of E2F3a on chemotherapeutic sensitivity of leukemic cells could be reversed by down-regulating CASP8AP2. Conclusions: E2F3a could promote transcription and expression of CASP8AP2. The effect of E2F3a on chemotherapeutic sensitivity of ALL cells was implemented by regulating CASP8AP2 expression to a great extent. [ABSTRACT FROM AUTHOR]

In this study, liquid chromatography-mass spectrometry(LC-MS) and high performance liquid chromatography(HPLC) were employed for qualitative and quantitative analysis of the steroidal saponins in rhizomes of Paris polyphylla var. yunnanensis from three different habitats cultured in vitro, in an attempt to explore whether the rhizomes of the medicinal herb cultured in vitro can synthesize the steroidal saponins, including polyphyllinsⅠ, Ⅱ, and Ⅶ, the quality markers specified in Chinese Pharmacopoeia(2020 edition). A total of 20 steroidal saponins were identified in the rhizomes from Changxin, Yunlong(S1), Fengyi, Dali(S2), and Niujie, Eryuan(S3): parisyunnanoside A and parisyunnanoside D or E, proto-polyphyllin Ⅱ, polyphyllins G and H, polyphyllinsⅠ, Ⅱ, Ⅴ, Ⅵ, and Ⅶ, dioscin, gracillin, prosapogenin A, Tg, isomer of Th, saponin Th, reclinatoside, proto-pairs D, pseudoproto-dioscin, and 23-O-glc-(23S,25R)-spirost-5-en-3β,23α,27-triol-3-O-rha-(1→2)-[ara(1→4)]-glc or 27-O-glc-(23S,25R)-spirost-5-en-3β,27α-diol-3-O-rha-(1→2)-[ara(1→4)]-glc. Among them, polyphyllinsⅠ, Ⅱ, and Ⅶ were detected in the rhizomes from S1, with the mass fraction of 0.109 1%, 0.165 2%, and 0.051 03%, respectively(total 0.325 3%). Polyphyllins Ⅱ and Ⅶ were identified in the rhizomes from S2 with the respective mass fraction of 0.192 2% and 0.074 23% and total content of 0.266 5%. Moreover, polyphyllins Ⅱ and Ⅶ were also found in the rhizomes from S3, which had the mass fraction of 0.207 7% and 0.186 9%, separately, with the total content of 0.394 6%. Thus, steroidal saponins, including the quality makers polyphyllins Ⅰ, Ⅱ, and Ⅶ recorded in Chinese Pharmacopoeia(2020 edition) can be synthesized in rhizomes of Paris polyphylla var. yunnanensis cultured in vitro, but their total content fails to meet the standard(0.60% in Chinese Pharmacopoeia). Therefore, in vitro culture of the Paris polyphylla var. yunnanensis is feasible, but the culture conditions need to be further improved.

Cochliomycin A is a compound with anti-barnacle settlement activity and low toxicity, but the molecular mechanism of the compound is unknown. Here, isobaric tags for the relative or absolute quantitation (iTRAQ) labeling proteomic method were applied to analyze changes in the proteome of Amphibalanus (=Balanus) amphitrite cyprids in response to cochliomycin A treatment. Cochliomycin A affected the cytochrome P450, glutathione S-transferase (GST) and NO/cGMP pathways, among which the NO/cGMP pathway was considered to play a key role in barnacle larval settlement, while the cytochrome P450 and the GST pathways are mainly for detoxification. The results of real-time PCR further suggested the NO/cGMP pathway was activated in response to cochliomycin A. Larval settlement assays revealed that S-methylisothiourea sulfate (SMIS) and 1H-(1,2,4)oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) rescued cyprids from cochliomycin A-induced inhibition of larval settlement. The findings supported the hypothesis that cochliomycin A inhibited barnacle larval settlement by stimulating the NO/cGMP pathway.

Objective: To study the methylation level in the promoter of caspase 8 associated protein 2 (CASP8AP2) gene between samples at diagnosis and in complete remission, and to investigate its relationship with clinical features and prognosis in children with acute lymphoblastic leukemia (ALL)., Methods: Diagnostic DNA samples from 109 newly diagnosed children with ALL admitted from August 2007 to March 2010, and 94 ALL children in CR (complete remission) among them were collected. Bisulfite modification and MethyLight method established by our research team were used to determine the methylation level of the two key CpG sites (at -1189 and -1176) of the promoter of CASP8AP2 gene., Results: The average methylation level of the two CpG sites in newly diagnosted samples was higher than that in CR samples (71.1% ± 1.7% vs 64.2% ± 21.2%) (P = 0.008). Analysis with receiver operating characteristic (ROC) curve showed that the area under curve was 0.687 (P = 0.024), indicating that the methylation level of the two CpG sites was able to predict relapse efficiently to some extent, 76.9% was chosed as a cutoff value to divide the patients into high methylation group (49 patients) and low methylation group (60 patients). The incidence of relapse in high methylation group was higher than that in low methylation group (20.4% vs 6.7%) (P = 0.044), five year relapse free survival in high methylation group was also lower than that in low methylation group (Log rank, P = 0.033). Furthermore, high methylation at new diagnosis were correlated with high level of minimal residual disease (MRD) before consolidation therapy (P = 0.011). In the 34 children with MRD ≥ 10(-4) at the end of induction remission, the relapse rate of high methylation patients was significantly higher than that of low methylation patients (8/16 vs 3/18)(P = 0.038)., Conclusion: The abnormal hypermethylation of the two CpG sites (at -1189 and -1176) of the promoter of the CASP8AP2 gene is possibly associated with leukemogenesis in childhood ALL. The treatment outcome is more poor in patients with hypermethylation than that in patients with low methylation. The combination of the methylation level of the two CpG sites and MRD level at the end induction remission is able to predict relapse more effectively.