IFN-γ affects pancreatic cancer properties by MACC1-AS1/MACC1 axis via AKT/mTOR signaling pathway

BACKGROUND

Metastasis-related in colon cancer 1 (MACC1) is highly expressed in a variety of solid tumours, but its role in pancreatic cancer (PC) remains unknown. Interferon gamma (IFN-γ) affecting MACC1 expression was explored as the potential mechanism following its intervention.

METHODS

Expressions of MACC1 treated with IFN-γ gradient were confirmed by quantitative real-time PCR (qRT-PCR) and western blot (WB). Proliferation, migration, and invasion abilities of PC cells treated with IFN-γ were analysed by CCK8, EDU, colony formation, Transwell (with or without matrix gel) and wound-healing assays. Expression of antisense long non-coding RNA of MACC1, MACC1-AS1, and proteins of AKT/mTOR pathway, (pho-)AKT, and (pho-)mTOR was also assessed by qRT-PCR and WB. SiRNA kit and lentiviral fluid were conducted for transient expression of MACC1 and stable expression of MACC1-AS1, respectively. Rescue assays of cells overexpressing MACC1-AS1 and of cells silencing MACC1 were performed and cellular properties and proteins were assessed by the above-mentioned assays as well.

RESULTS

IFN-γ inhibited MACC1 expression in a time- and dose-dependent manner; 100 ng/mL IFN-γ generally caused downregulation of most significant (p ≤ 0.05). In vitro experiments revealed that IFN-γ decreased cellular proliferation, migration, and invasion abilities and downregulated the expression of pho-AKT and pho-mTOR (p ≤ 0.05). Conversely, overexpression of MACC1-AS1 upregulated pho-AKT and pho-mTOR proteins, and reversed cellular properties (p ≤ 0.05). Rescue assays alleviated the above changes of pho-AKT/ mTOR and cellular properties.

CONCLUSION

IFN-γ affected PC properties by MACC1-AS1/MACC1 axis via AKT/mTOR signaling pathway, which provides novel insight for candidate targets for treating PC.

[Study on the related factors of intestinal obstruction after cesarean section]

Objective: To analyze the related factors of intestinal obstruction after cesarean section. Methods: From April 2009 to April 2019, 500 patients with cesarean section and postoperative intestinal obstruction in Beijing Maternity Hospital Affiliated to Capital Medical University were taken as the case group, and 500 patients without postoperative intestinal obstruction who underwent cesarean section on the same day as the case group were taken as the control group. The data of patients' general characteristics, pregnancy complications, blood routine and biochemical indexes, and operation related factors were collected to compare the differences between patients with intestinal obstruction and patients without intestinal obstruction. Multivariate logistic regression model was used to analyze the related factors of intestinal obstruction after cesarean section. Results: The age of 500 patients with intestinal obstruction after cesarean section was (33.3±4.2) years, and the age of 500 patients without intestinal obstruction after cesarean section was (31.6±3.9) years. The incidence of pregnancy complications in patients with intestinal obstruction was higher than that in patients without intestinal obstruction (all P<0.05). Multivariate analysis showed that preoperative anemia [OR(95%CI) of 5.318(1.522-18.580), P=0.009], postoperative low protein [OR(95%CI) of 0.376(0.143-0.993), P=0.048], intraoperative bleeding ≥500 ml [OR(95%CI) of 3.085(1.551-6.136), P=0.001],intraoperative adhesion [OR(95%CI) of 2.856(1.285-6.347), P=0.010] were the risk factor of intestinal obstruction after cesarean section. The intraoperative application of antiadhesion drugs [OR(95%CI) of 0.322(0.158-0.654), P=0.002] was the protective factor of intestinal obstruction after cesarean section. Conclusions: Patients with anemia and low protein have an increased risk of intestinal obstruction after cesarean section.

[Clinical outcomes of intracytoplasmic sperm insemination with micro amount frozen-thawed diagnostic sperm in the treatment of azoospermia]

Objective: To investigate the efficacy and clinical outcomes of intracytoplasmic sperm injection (ICSI) with micro amount frozen-thawed diagnostic sperm obtained by microdissection testicular sperm extraction (microTESE), percutaneous epididymal sperm as-piration (PESA) and testicularsperm extraction (TESA) in the treatment of azoospermia. Methods: A retrospective analysis was performed on 736 ICSI cycles of azoospermia patients.In Reprocluctive Medicine Center of the First Affiliated Hospital of Zhengzhou University from January 2018 to December 2019. Including 199 ICSI cycles (microTESE 47cycles, PESA 75cycles and TESA 77 cycles) with micro amount frozen-thawed diagnostic sperm and 537 ICSI cycles (microTESE 23 cycles, PESA 111 cycles and TESA 403 cycles) with fresh micro amount sperm. The general conditions, embryo development conditions and clinical outcomes of patients were compared between and within the two groups. Results: The recovery rate of PESA group was significantly lower than that of TESA group (89.3% vs 98.7%), P<0.05. The rate of 2PN in the fresh control group was significantly higher than that in the experiment group (75.5% vs 71.3%) and the rate of 2PN in the fresh microTESE and PESA groups were also significantly higher than those of the frozen-thawed microTESE and PESA groups (74.2% vs 64.6%) and (78.5% vs 72.4%), P<0.05. Both the rate of D5 blastocyst formation and high quality blastocyst in the fresh group were significantly lower than that in the experiment group (26.9% vs 32.9%) and (15.1% vs 18.0%), P<0.05; both the rate of early cleavage and blastocyst formation in the fresh microTESE group were significantly lower than that in the frozen-thawed microTESE group (55.1% vs 68.3%) (27.3% vs 39.3%), P<0.05. Both the rate of 8 cells embryos and blastocyst formation in the fresh TESA group were significantly lower than those of the TESA frozen-thawed group (41.3% vs 46.0%) (26.5% vs 32.4%), P<0.05. There was no significant difference in pregnancy rate and planting rate between or within the groups(P>0.05). The abortion rate in the frozen-thawed group was significantly higher than the fresh group (12.0% vs 4.0%), P<0.05, especially the abortion rate in the PESA frozen-thawed group was significantly higher than the fresh group (18.0% vs 1.7%), P<0.05. There was no significant difference in gender, weight and body length between the fresh group and the frozen-thawed group (P>0.05), but there were two malformed babies born in the frozen-thawed group. Conclusions: Frozen-thawed microinjection of diagnostic microspermatozoa is a feasible method for the treatment of asthenospermia.There was on significonty difference in pregnancy rate and planting rate between of with in the groups. However, significantly higher than the fresh PESA group of the influence on offspring needs to be further studied.

[Primary mediastinal large B-cell lymphoma: a clinicopathologic study of 27 cases]

Objective: To study the clinicopathologic characteristics and diagnostic criteria of primary mediastinal B-cell lymphoma (PMBL), and to distinguish PMBL from classic Hodgkin lymphoma(CHL) and systemic diffuse large B-cell lymphoma(DLBCL). Methods: The clinical features, histologic findings, results of immunohistochemical study and prgnosis in 27 PMBL cases were analyzed, with review of literature. Results: The age of patients ranged from 19 to 82 years (median age 34 years). All cases were located in the mediastinum and frequently accompanied by superior vein cava syndrome. Histologically, the tumor cells were pleomorphic and diffusely distributed. Clear cytoplasm and spindle tumor cells were seen in some cases. Varying amount of sclerosing stroma with collagen deposition was seen.Immunohistochemical study showed that the tumor cells were positive for CD20(100%, 27/27), CD30 (64.0%, 16/25), CD23 (77.3%, 17/22) and p63 (16/19). Clonal B cell gene rearrangement was seen. Conclusions: PMBL is a subtype of diffuse large B-cell lymphoma with various histomorphology. Immunohistochemistry can help to confirm the diagnosis, and the prognosis is better than diffuse large B cell lymphoma, not otherwise specified.

[MGMT expression in primary central nervous system diffuse large B cell lymphoma and its relationship with prognosis]

Objective: To study the correlation between MGMT expression, clinicopathologic features and post-chemotherapy prognosis in patients with primary central nervous system lymphoma diffuse large B-cell lymphoma (PCNS-DLBCL). Methods: MGMT expression was detected in 76 cases of PCNS-DLBCL by EnVision method with immunohistochemical staining.Follow-up data including treatment response and overall survival time, were analyzed. Results: The rate of MGMT expression in PCNS-DLBCL was 67.1%(51/76). The MGMT expression rate in male patients was higher than that in female(P<0.05). Univariate analysis showed that these clinical pathological characteristics affected the overall survival of PCNS-DLBCL patients, including age and Hans algorithm, although no statistical significance was detected(P value was 0.065 and 0.069 respectively). The overall survival of the patients with positive MGMT and aged over 60 years was shorter after chemotherapy than those without chemotherapy (P=0.022). In the patients aged over 60 years, the prognosis of MGMT-positive patients was significantly better than MGMT-negative patients (P=0.044). Conclusions: The expression of MGMT is more commonly found in male patients. In the patients aged over 60 years with the same therapy, the prognosis is better in the MGMT-negative ones. Detection of MGMT protein expression can provide some guidance in choice of treatment modalities in PCNS-DLBCL patients.

Sevoflurane promotes the expansion of glioma stem cells through activation of hypoxia-inducible factors in vitro

BACKGROUND

Growing evidences indicate that inhalational anaesthetics can enhance the growth and malignant potential of tumour cells and may affect tumour recurrence after surgery. Tumour stem cells play a vital role in tumour recurrence. This study investigates the effect of sevoflurane on glioma stem cells (GSCs) in vitro and the underlying molecular mechanisms in this process.

METHODS

Cultured GSCs were exposed to clinically relevant concentrations and durations of sevoflurane exposure. Cell proliferation and self-renewal capacity were determined. Expression of the stem cell marker CD133, vascular endothelial growth factor (VEGF), hypoxia-inducible factors (HIFs), and phosphorylated Akt, which is a protein kinase invoved in multiple cellular processes, were measured using western blotting. Small interfering RNAs and an Akt inhibitor were used to investigate specific pathways.

RESULTS

Compared with controls, cells exposed to 2% sevoflurane for 6 h induced a larger number of proliferated cells (31.2±7.6% vs 19.0±5.8%; P<0.01). Levels of CD133, VEGF, HIF-1α, HIF-2α, and p-Akt were up-regulated by sevoflurane in a time- and concentration-dependent manner. Small interfering RNA against HIFs decreased the percentage of proliferating GSCs after sevoflurane exposure and pre-treatment of cells with an Akt inhibitor abrogated the expression of HIFs induced by sevoflurane.

CONCLUSIONS

Sevoflurane can promote the expansion of human GSCs through HIFs in vitro. Inhaled anaesthetics may enhance tumour growth through tumour stem cells.

GABAergic excitotoxicity injury of the immature hippocampal pyramidal neurons' exposure to isoflurane

BACKGROUND

Certain anesthetics exhibit neurotoxicity in the brains of immature but not mature animals. γ-Aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the adult brain, is excitatory on immature neurons via its action at the GABAA receptor, depolarizing the membrane potential and inducing a cytosolic Ca2+ increase ([Ca2+]i), because of a reversed transmembrane chloride gradient. Recent experimental data from several rodent studies have demonstrated that exposure to isoflurane during an initial phase causes neuronal excitotoxicity and apoptosis. GABAA receptor-mediated synaptic voltage-dependent calcium channels' (VDCCs) overactivation and Ca2+ influx are involved in these neural changes.

METHODS

We monitored [Ca2+]i using Fluo-4 AM fluorescence imaging. Using whole-cell patch clamp techniques, IVDCC (voltage-dependent calcium channel currents) were recorded from primary cultures of rat hippocampal neurons (5-day culture) exposed to isoflurane. To further investigate the neurotoxicity of high cytosolic-free calcium after isoflurane in a dose- and time-dependent manner, the possibility of increased caspase-3 levels was evaluated by Western blot and quantitative real-time polymerase chain reaction. Statistical significance was assessed using the Student t test or 1-way analysis of variance followed by the Tukey post hoc test.

RESULTS

Under control conditions, isoflurane enhanced the GABA-induced [Ca2+]i increase in a dose-dependent manner. Dantrolene and nicardipine markedly inhibited this enhancement mediated by isoflurane. Moreover, in Ca2+-free media, pretreatment with isoflurane did not show any influence on the caffeine-induced increase of [Ca2+]i. Similarly, using whole-cell recording, isoflurane increased the peak amplitude of IVDCC in the cultured neurons from rat hippocampus by depolarization pulses. Isoflurane (0.25, 0.5, 0.75, and 1 minimum alveolar concentration [MAC]) potentiated IVDCC peak current amplitude by 109.11%±9.03%, 120.56%±11.46%, 141.33%±13.87%, and 146.78%±15.87%, respectively. To analyze variation in protein levels, the effect of treatments with isoflurane on caspase-3 activity was dose- and time-dependent, reaching a maximal caspase-3 activity after exposure to 1 MAC for 6 hours (P<0.001). However, in the mRNA levels, hippocampal caspase-3 mRNA levels began to be significantly increased in isoflurane-treated developing rat hippocampal neurons after 6 hours of exposure to 0.25 MAC isoflurane (P<0.001).

CONCLUSIONS

Isoflurane-mediated enhancement of GABA-triggered [Ca2+]i release results from membrane depolarization with subsequent activation of VDCCs and further Ca2+-induced Ca2+ release from the ryanodine-sensitizing Ca2+ store. An increase in [Ca2+]i, caused by activation of the GABAA receptor and opening of VDCCs, is necessary for isoflurane-induced calcium overload of immature rat hippocampal neurons, which may be involved in the mechanism of an isoflurane-induced neurotoxic effect in the developing rodent brain.

GTP requirement for isoproterenol activation of calcium channels in vascular myocytes

The effects of activating the beta-adrenoceptor pathway on calcium current (ICa) in rabbit portal vein (PV) were studied in myocytes freshly isolated by collagenase and elastase treatment. ICa was measured at room temperature (20 degrees C) using whole cell, voltage-clamp methods from a holding potential of -60 mV in cells dialyzed with a pipette solution containing (mM) 100 CsCl, 20 tetraethylammonium chloride, 5 NaCl, 5 MgATP, 20 N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES), and 10 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). The cells were superfused with a solution containing (mM) 140 NaCl, 5 KCl, 1 MgCl2, 5 CaCl2, 10 HEPES, and 10 glucose. Only L-type ICa was present in these myocytes, averaging 3.5 +/- 0.3 pA/pF at +10 mV under control conditions. With 0.1 mM guanosine 5'-triphosphate (GTP) added to the pipette solution, 1 microM isoproterenol (Iso) or forskolin (Fsk) uniformly increased ICa: Iso by 45 +/- 5% and Fsk by 88 +/- 11%. This augmentation of ICa was not associated with significant changes in the voltage dependence of activation or inactivation but was associated with a small increase in the rate of inactivation of ICa. Fsk was also associated with an increased rate of ICa activation. The Iso effect was blocked by pretreatment with 1 microM propranolol and reversed by propranolol after Iso exposure. The ICa response to 10 microM Iso or Fsk was smaller than the response to 1 microM, with some cells showing a steady-state reduction in ICa. When the latter occurred, the voltage dependence of availability was shifted to the left by 5 +/- 0.4 mV.(ABSTRACT TRUNCATED AT 250 WORDS)

Saturation of postsynaptic glutamate receptors after quantal release of transmitter

Miniature excitatory postsynaptic currents (mEPSCs) were elicited from small numbers of release sites after brief microperfusion of Ba2+ and K+ onto proximal dendritic processes of hippocampal neurons in culture. Temporal summation of closely timed mEPSCs deviated significantly from linearity. The number of instances of closely timed mEPSCs that were also closely matched in terms of peak amplitudes was significantly greater than that expected by chance. Amplitude pairing became statistically more significant after prolongation of mEPSC duration and inhibition of glutamate receptor desensitization with cyclothiazide. These results are best explained by postsynaptic receptors that approach saturation after quantal release of transmitter.

Expression of non-NMDA glutamate receptor channel genes by clonal human neurons

Treatment of the human teratocarcinoma line NTera2/c1.D1 (NT2) with retinoic acid induces terminal neuronal differentiation. In a previous study, we found that the neurons obtained in this way express functional N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptor channels. We now show by reverse transcriptase-polymerase chain reaction and Southern blotting that these neurons transcribe each of the nine known non-NMDA glutamate receptor genes (GluR1-7, Ka-1, and Ka-2) and that four of these genes (GluR2, GluR6, GluR7, and Ka-1) are also transcribed by undifferentiated NT2 cells. Patch clamp studies demonstrate that individual non-NMDA glutamate receptor channels are readily isolated from NT2-derived neurons and that these channels are potently modulated by the desensitization blocker cyclothiazide. NT2-derived neurons are susceptible to kainate excitotoxicity but are not injured by prolonged exposure to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate. We expect that the NT2-derived human neuronal culture system will facilitate studies of human neuronal non-NMDA glutamate receptor channels and of the pathophysiology of neuronal excitotoxicity.

Inducible expression of neuronal glutamate receptor channels in the NT2 human cell line

Glutamate receptor (GluR) channels are responsible for a number of fundamental properties of the mammalian central nervous system, including nearly all excitatory synaptic transmission, synaptic plasticity, and excitotoxin-mediated neuronal death. Although many human and rodent neuroblast cell lines are available, none has been directly shown to express GluR channels. We report here that cells from the human teratocarcinoma line NT2 are induced by retinoic acid to express neuronal N-methyl-D-aspartate (NMDA) and non-NMDA GluR channels concomitant with their terminal differentiation into neuron-like cells. The molecular and physiologic characteristics of these human GluR channels are nearly identical to those in central nervous system neurons, as demonstrated by PCR and patch clamp recordings, and the cells demonstrate glutamate-induced neurotoxicity.

[An electron microscopic study of thyroxine against ototoxicity of kanamycin]

Forty-five guinea pigs were randomly divided into 2 groups: 15 in the control group and 30 in the experimental group. All animals were injected immediately with 400 mg/kg kanamycin for 10 days. At the same time, the experimental animals were given orally 10 mg/kg thyroxin every other day 5 times. All animals were decapitated 10 days after administration of drugs and measurement of ABR. Then, the specimens of cochlea were prepared for both SEM and TEM. The result of SEM showed that the degeneration and loss of stereocilium in each turn was significantly milder in the experimental group than in the control. Under TEM, outer and inner hair cells showed changes caused by kanamycin. In the experimental group, the mitochondrias were basically normal. The secondary lysosomes gathered under cuticular plate and supranuclear area. In the control group, the mitochondria showed pyknosis and high density, and multivesicular bodies were increased. The cytoplasm was swelling. There were many vacuoles produced by accumulation of liquid in the cytoplasm. Based on the findings of ultrastructural changes of cochlear hair cells, the mechanism of thyroxine against ototoxicity of kanamycin was discussed.

Modulation of the time course of fast EPSCs and glutamate channel kinetics by aniracetam

It is generally accepted that glutamate serves as the neurotransmitter at most excitatory synapses in the mammalian central nervous system (CNS). Synaptic release of glutamate may trigger a fast and a slow excitatory postsynaptic current (EPSC). The slow EPSC is mediated by N-methyl-D-aspartate (NMDA) receptor channels, whereas the fast EPSC is mediated by non-NMDA receptor channels. The nootropic agent aniracetam selectively and reversibly slows the desensitization kinetics of non-NMDA channels and lengthens their single-channel open times. Antiracetam also modulates the kinetics of the fast EPSC in a manner that mirrors its action on the kinetics of the non-NMDA channels. These results support the hypothesis that the properties of the non-NMDA glutamate channels rather than the rate of neurotransmitter clearance are the primary determinants of the kinetics of the fast EPSC in the mammalian CNS.

Iconic indexing by 2-d strings

In this paper, we describe a new way of representing a symbolic picture by a two-dimensional string. A picture query can also be specified as a 2-D string. The problem of pictorial information retrieval then becomes a problem of 2-D subsequence matching. We present algorithms for encoding a symbolic picture into its 2-D string representation, reconstructing a picture from its 2-D string representation, and matching a 2-D string with another 2-D string. We also prove the necessary and sufficient conditions to characterize ambiguous pictures for reduced 2-D strings as well as normal 2-D strings. This approach thus allows an efficient and natural way to construct iconic indexes for pictures.

Parsing and translation of (attributed) expansive graph languages for scene analysis

In this paper, we suggest a class of (attributed) expansive graph grammars which generate languages contained in a graph family ¿. It turns out that by means of node renumbering using a very effi-cient algorithm, any graph in ¿ can be converted into a standard form, which enables the use of related string representation for that graph to facilitate the syntax analysis. As a consequence, the syntax analysis of (attributed) expansive graph language is very efficient and almost like the parsing of tree languages. Furthermore, a syntax-directed transla-tion can be established for mapping one (attributed) expansive graph language to another. Finally, since many relational graphs for scene analysis can be considered as belonging to these graph languages, the proposed graph grammar model appears to be quite attractive from the application point of view.