Transcriptional activation of nuclear estrogen receptor and progesterone receptor and its regulation / 生理学报

Estrogen receptor (ER) and progesterone receptor (PR) are two important members of steroid receptors family, an evolutionarily conserved family of transcription factors. Upon binding to their ligands, ER and PR enter cell nucleus to interact with specific DNA element in the context of chromatin to initiate the transcription of diverse target genes, which largely depends on the timely recruitment of a wide range of cofactors. Moreover, the interactions between steroid hormones and their respective receptors also trigger post-translational modifications on these receptors to fine-tune their transcriptional activities. Besides the well-known phosphorylation modifications on tyrosine and serine/threonine residues, recent studies have identified several other covalent modifications, such as ubiquitylation and sumoylation. These post-translational modifications of steroid receptors affect its stability, subcellular localization, and/or cofactor recruitment; eventually influence the duration and extent of transcriptional activation. This review is to focus on the recent research progress on the transcriptional activation of nuclear ER and PR as well as their physiological functions in early pregnancy, which may help us to better understand related female reproductive diseases.

Gefitinib analogue V1801 induces apoptosis of T790M EGFR-harboring lung cancer cells by up-regulation of the BH-3 only protein Noxa.

Treatment of non-small cell lung cancer (NSCLC) with drugs targeting the epidermal growth factor receptor (EGFR), e.g., gefitinib and erlotinib, will eventually fail because of the development of secondary mutations such as T790M in EGFR. Strategies to overcome this resistance are therefore an urgent need. In this study, we synthesized a dozen of novel gefitinib analogues and evaluated their effects on L858R/T790M-EGFR harboring NSCLC cells, and reported that one of these gefitinib mimetics, N-(2-bromo-5-(trifluoromethyl) phenyl)-6-methoxy-7-(3-(piperidin-1-yl)propoxy)quinazolin-4-amine (hereafter, V1801), triggered apoptosis of the NSCLC cells and overcame gefitinib-resistance in mice inoculated with NCI-H1975 cells. Though V1801 only moderately inhibited EGFR kinase activity, it markedly induced the expression of the BH3-only protein Noxa, and Noxa silencing significantly reduced V1801-induced apoptosis of NCI-H1975 cells. It is showed that V1801 interfered with the expression of the transcription factor c-Myc and the extracellular signal regulated kinase (Erk) pathway. V1801 in combination with proteasome inhibitor bortezomib exerted enhanced cytotoxicity in NCI-H1975 cells possibly due to potentiated induction of Noxa expression. These data indicate that gefinitib analogues with weak EGFR inhibitory activity may overcome drug-resistance via activation of BH-3 only pro-apoptotic proteins, and V1801 may have therapeutic potentials for NSCLC.

Identification of an annonaceous acetogenin mimetic, AA005, as an AMPK activator and autophagy inducer in colon cancer cells.

Annonaceous acetogenins, a large family of naturally occurring polyketides isolated from various species of the plant genus Annonaceae, have been found to exhibit significant cytotoxicity against a variety of cancer cells. Previous studies showed that these compounds could act on the mitochondria complex-I and block the corresponding electron transport chain and terminate ATP production. However, more details of the mechanisms of action remain ambiguous. In this study we tested the effects of a set of mimetics of annonaceous acetogenin on some cancer cell lines, and report that among them AA005 exhibits the most potent antitumor activity. AA005 depletes ATP, activates AMP-activated protein kinase (AMPK) and inhibits mTOR complex 1 (mTORC1) signal pathway, leading to growth inhibition and autophagy of colon cancer cells. AMPK inhibitors compound C and inosine repress, while AMPK activator AICAR enhances, AA005-caused proliferation suppression and subsequent autophagy of colon cancer cells. AA005 enhances the ATP depletion and AMPK activation caused by 2-deoxyglucose, an inhibitor of mitochondrial respiration and glycolysis. AA005 also inhibits chemotherapeutic agent cisplatin-triggered up-regulation of mTOR and synergizes with this drug in suppression of proliferation and induction of apoptosis of colon cancer cells. These data indicate that AA005 is a new metabolic inhibitor which exhibits therapeutic potentials in colon cancer.

Influence of the mutants of hepatitis B surface antigen on the cell immunity / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the influence of the mutants of hepatitis B surface antigen on the cell immunity.</p><p><b>METHODS</b>The recombinant plasmids of NS2Swt, NS2S126, NS2S133, NS2S141 and NS2S145 were transfected into Chinese hamster ovary (CHO) cells and the expressed proteins were detected by means of ELISA. Following PHA-activated lymphoblasts proliferation assay and IFN-gamma, IL-2, IL-10 induction assay were done with these proteins.</p><p><b>RESULTS</b>It was identified that these proteins of HBsAg could stimulate human lymphoblasts proliferation. Besides, there were no significant difference between the mutants and the wild. It was deserved to point out that the HBsAg with T126S mutation could increase the expression of IFN-gamma in the culture medium while the HBsAg with M133T mutation induced more expression of IL-10.</p><p><b>CONCLUSION</b>The results suggested that the cellular immune response to mutants of HBV might not be strengthened or weakened. But it should not be ignored that HBV T126S or M133T mutation may assert a potential impact on the cell immunity.</p>

The suppression of melatonin on mouse oocyte in vitro maturation of mouse / 中国应用生理学杂志

<p><b>AIM</b>To study whether melatonin has effect on oocyte maturation of mouse in vitro.</p><p><b>METHODS</b>Mouse oocytes were cultured in maturation medium, HX-medium, or HX-medium supplemented with FSH, and the effects of MT on meiotic maturation of mouse oocyte were examined.</p><p><b>RESULTS</b>(1) MT at all doses of 0.1 g/L, 0.02 g/L, 0.4 g/L or 0.8 g/L inhibited the formation of PB1 in CEO cultured in maturation medium and had no effect on GVBD. (2) MT could delay GVBD and the extrusion of PB1 in CEOs of mouse oocytes by dynamic curves. In contrast to the control, GVBD and PB1 extrusion of oocytes in the treated groups had been delayed by 8-10 hours and 3-4 hours respectively. (3) MT inhibited the effect of FSH on resumption of meiosis, but no effect on the formation of PB1. (4) MT and HX had cooperation effects on spontaneous oocyte maturation in CEO, but not in DO.</p><p><b>CONCLUSION</b>MT is able to affect mouse oocyte maturation and the regulation mechanisms may be related to cumulus cells.</p>

Efficacy of recombinant hepatitis B vaccine and low-dose hepatitis B immune globulin in preventing mother-infant transmission of hepatitis B virus infection / 中华流行病学杂志

<p><b>OBJECTIVE</b>To determine the efficacy of recombinant hepatitis B (rHB) vaccine and low-dose hepatitis B immune globulin (HBIG) in the prevention of mother-infant transmission of hepatitis B virus (HBV) infection.</p><p><b>METHODS</b>rHB vaccine was administered to two groups of healthy neonates born to mothers with both hepatitis B surface antigen and e antigen positive in Guangxi, Hunan and Hebei province. Two hundred eighty-nine subjects were included in active immunization group, receiving triple doses of rHB vaccine given i.m. at 0, 1 and 6 month intervals; while 186 subjects receiving 50 IU HBIG at birth with triple doses of rHB vaccine in the low-dose HBIG group.</p><p><b>RESULTS</b>Efficacy of active immunization alone was 87.8% (95% CI: 83.6 - 91.9). Efficacy of rHB vaccine and HBIG was 91.2% (95% CI: 86.7 - 95.6). No significant differences in efficacy by type of rHB vaccine (P = 0.707 2), immunoprophylaxis programs (P = 0.295 5) and regions of living (P = 0.998 7) were noticed. Seroprotection rates (anti-HBs >or= 10 mIU/ml) were detected in 91.1% and 93.5% in rHB vaccine alone recipients and rHB vaccine plus HBIG recipients, with geometric mean titer (GMT) of 153 mIU/ml and 164 mIU/ml at 1 year of age, respectively. Anti-rHBs decreased significantly with years after vaccination (chi(2) = 60.47, P = 0.000 1). Seroprotection rates of anti-rHBs antibodies decreased to 65.0% and 66.6% at 4 years of age in rHB vaccine alone recipients and rHB vaccine plus HBIG recipients, with GMT of 55 mIU/ml and 56 mIU/ml, respectively.</p><p><b>CONCLUSION</b>These results suggested that the effectiveness of rHB vaccine plus low-dose HBIG was much better than only active plasma-derived vaccine; however, methods used for anti-rHBs assay need to be evaluated and verified.</p>

Effect of angiotensin II on follicular atresia in mouse / 生理学报

The effect of angiotensin II (Ang II) on the follicular development was studied by using an animal model of follicular atresia induced by pregnant mare s serum gonadotropin (PMSG). The results showed that: (1) a large number of atretic follicles were found in the ovary of 24-day-old mouse after 6-day treatment of PMSG. Deoxyribonucleic acid (DNA) extracted from granulosa cells clearly showed a ladder band under agarose gel electrophoresis analysis. (2) the contents of Ang II in the ovary extremely increased with the development of follicular atresia. (3) Ang II significantly antagonized the stimulating effect of the follicle-stimulating hormone (FSH) on estradiol (E(2)) generation of granulosa cells. It is suggested that Ang II may be involved in the regulation of follicular atresia in mouse.