18F-FDG PET/CT Prognostic Role in Diffuse Large B-cell Lymphoma Following Chemotherapy / 中山大学学报(医学科学版)

ObjectiveTo assess the prognostic value of 18F-FDG PET/CT parameters for predicting therapeutic response in diffuse large B-cell lymphoma （DLBCL）. MethodsWe retrospectively analyzed the clinical data and 18F-FDG PET/CT radiomics features of 81 DLBCL patients enrolled between June 2015 and October 2020. Multivariate logistic regression analysis was used to identify the predictive factors for therapeutic response of DLBCL， based on which a predictive model was developed accordingly. The performance of the model was evaluated by receiver operating characteristic （ROC） curves and calibration plots. ResultsDuring the two years after first chemotherapy， 23 patients （28.3%） developed relapse and 58 patients （71.7%） had progression-free survival （PFS）. The analysis for the predictive capability of the binary logistic regression model incorporating the PET/CT features revealed that the imaging features of 18F-FDG PET/CT after chemotherapy were independent prognostic factors for PFS. Among them， SUVTHR-mean2 was the most important factor for predicting therapeutic response in DLBCL patients after chemotherapy， with a cutoff value of 2.00 （AUC=0.81）. Conclusions18F-FDG PET/CT showed a valuable prognostic performance for PFS in DLBCL patients after chemotherapy， with the imaging feature after chemotherapy SUVTLR-mean2 being the optimal independent predictor. Our predictive model of imaging features might have an important prognostic value in assessing the risk of disease progression， guiding the treatment and follow-up protocol， improving therapeutic efficiency and cutting down the medical cost.

SF3B1 mutation predicts unfavorable treatment-free survival in Chinese chronic lymphocytic leukemia patients.

BACKGROUND: Splicing factor 3b subunit 1 (SF3B1), a splicing factor modulating RNA alternative splicing, is frequently mutated in multiple hematological malignancies including myelodysplastic syndromes and chronic lymphocytic leukemia (CLL). The clinical impact of SF3B1 mutation on CLL remains controversial especially for patients of Asian descent. METHODS: We retrospectively analyzed the frequency of SF3B1 mutation by Sanger sequencing in 399 newly diagnosed Chinese CLL patients. RESULTS: SF3B1 mutation was detected in 5.5% (22/399) of the studied cohort with 59.1% of them being c.A2098G (p.K700E). SF3B1 mutation was common in patients with unmutated immunoglobulin heavy chain variable region gene, positive CD38 and positive ZAP-70. Survival analysis showed that SF3B1 mutation was associated with short treatment-free survival (TFS), but not overall survival (OS). We then developed 2 new risk models, named CLL-IPI-S and CLL-PI, according to the SF3B1 mutation status and CLL-international prognostic index (CLL-IPI); CLL-PI showed greater power to predict TFS than CLL-IPI in Chinese CLL patients. CONCLUSIONS: Our data suggest a low incidence and adverse clinical significance of SF3B1 mutation in newly diagnosed Chinese CLL patients.

Analysis of the miRNA-mRNA networks in malignant transformation BEAS-2B cells induced by alpha-particles.

The aim of this study was to determine the toxicity induced by irradiation with alpha-particles on malignant transformation of immortalized human bronchial epithelial cells (BEAS-2B) using miRNA-mRNA networks. The expression of BEAS-2B cells was determined by measuring colony formation, mtDNA, mitochondrial membrane potential (MMP), and ROS levels. Changes in BEAS-2B cell gene expression were observed and quantified using microarrays that included an increase in 157 mRNA and 20 miRNA expression and a decrease in 77 mRNA and 48 miRNA. Bioinformatic software was used to analyze these different mRNA and miRNA, which indicated that miR-107 and miR-494 play an important role in alpha-particles-mediated cellular malignant transformation processes. The pathways related to systemic lupus erythematosus, cytokine-cytokine receptor interaction, MAPK signaling pathway, regulation of actin cytoskeleton, and cell adhesion molecules (CAMs) were stimulated, while those of ribosome, transforming growth factor (TGF)-beta signaling pathway, and metabolic pathways were inhibited. Data suggest that miRNA and mRNA play a crucial role in alpha-particles-mediated malignant transformation processes. It is worth noting that three target genes associated with lung cancer were identified and upregulated PEG 10 (paternally expressed gene 10), ARHGAP26, and IRS1.

Norcantharidin induced DU145 cell apoptosis through ROS-mediated mitochondrial dysfunction and energy depletion.

Norcantharidin (NCTD), a demethylated analog of cantharidin derived from blister beetles, has attracted considerable attentions in recent years due to their definitely toxic properties and the noteworthy advantages in stimulating bone marrow and increasing the peripheral leukocytes. Hence, it is worth studying the anti-tumor effect of NCTD on human prostate cancer cells DU145. It was found that after the treatment of NCTD with different concentrations (25-100 µM), the cell proliferation was significantly inhibited, which led to the appearance of micronucleus (MN). Moreover, the cells could be killed in a dose-/time-dependent manner along with the reduction of PCNA (proliferating cell nuclear antigen) expression, destruction of mitochondrial membrane potential (MMP), down-regulation of MnSOD, induction of ROS, depletion of ATP, and activation of AMPK (Adenosine 5'-monophosphate -activated protein kinase) . In addition, a remarkable release of cytochrome c was found in the cells exposed to 100 µM NCTD and exogenous SOD-PEG could eliminate the generation of NCTD-induced MN. In conclusion, our studies indicated that NCTD could induce the collapse of MMP and mitochondria dysfunction. Accumulation of intercellular ROS could eventually switch on the apoptotic pathway by causing DNA damage and depleting ATP.

Effect of tetrandrine eye drops on expression of apoptotic protein and transforming growth factor-β2 in human Tenon capsule fibroblast in vitro / 中华实验眼科杂志

BackgroundOur previous study determined that tetrandrine (Tet) has an inhibitory effect on the proliferation of human Tenon capsule fibroblasts ( TCFs ) in vitro,but its mechanism is poorly understood.ObjectiveThis study was to investigate the effect mechanism of Tet on human TCFs.MethodsHuman TCFs were isolated and cultured from scleral tissue of donor using explant technique.The cells were identified by vimentin antibody staining and morphology.The third generation of cells were seeded in the culture plate at the density of 1 × 105 cells/ml.Twenty-four hours after inoculation,the Tet of 1 × 10-5 mol/L was added in the well of culture plate,and the cells cultured only in 1640 medium served as the control group.The apoptosis of the cells was assessed by TUNEL,and the expressions of bax,bel-2,transforming growth factor-β2 (TGF-β2 ) in TCFs were detected using immunochemistry.Results The cultured cells showed the features of the fibroblasts in shape with the positive response for vimentin.A number of TUNEL positive cells were seen in Tet group and no TUNEL positive response was found in control group.The expression levels (A value) of bax,bcl-2 and TGF-~ protein in TCFs were 0.577 ± 0.009,0.430±0.012 and 0.341 ±0.017 in Tet group,and those in control group were 0.320±0.015,0.819±0.021 and 0.624±0.014 respectively,showing statistically significant differences between two groups( t =33.277,-35.356,-28.093,P＜0.01 ).Conclusions Tet suppresses the proliferation of human TCFs through up-regulating the expression of bax and down-regulating the expressions of bcl-2 and TGF-β2 in vitro.

Microarray profiles on age-related genes in the earlier postnatal rat visual cortex / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Accumulating evidence indicates that both innate and adaptive mechanisms are responsible for the postnatal development of the mammalian visual cortex. Most of the studies, including gene expression analysis, were performed on the visual cortex during the critical period; few efforts were made to elucidate the molecular changes in the visual cortex during much earlier postnatal stages. The current study aimed to gain a general insight into the molecular mechanisms in the developmental process of the rat visual cortex using microarray to display the gene expression profiles of the visual cortex on postnatal days.</p><p><b>METHODS</b>All age-matched Sprague-Dawley rats in various groups including postnatal day 0 (P0, n = 20), day 10 (P10, n = 15), day 20 (P20, n = 15) and day 45 (P45, n = 10) were sacrificed respectively. Fresh visual cortex from the binocular area (Area 17) was dissected for extraction of total RNA for microarray analyses. Taking advantage of annotation information from the gene ontology and pathway database, the gene expression profiles were systematically and globally analyzed.</p><p><b>RESULTS</b>Of the 31 042 gene sequences represented on the rat expression microarray, more than 4000 of the transcripts significantly altered at days 45, 20 or 10 compared to day 0. The most obvious alteration of gene expression occurred in the first ten days of the postnatal period and the genomic activities of the visual cortex maintained a high level from birth to day 45. Compared to the gene expression at birth, there were 2630 changed transcripts that shared in three postnatal periods. The up-regulated genes in most signaling pathways were more than those of the down-regulated genes.</p><p><b>CONCLUSIONS</b>Analyzing gene expression patterns, we provide a detailed insight into the molecular organization of the developing visual cortex in the earlier postnatal rat. The most obvious alteration of gene expression in visual cortex occurred in the first ten days. Our data were a basis to identify new relevant candidate genes that control visual cortex development.</p>

Tyrosinase small interfering RNA effectively suppresses tyrosinase gene expression in vitro and in vivo.

Tyrosinase is a bifunctional enzyme which oxidizes the initial step of melanin biosynthesis, that is, conversion of tyrosine to dopa and subsequently dopa to dopaquinone. It is a glycosylated protein and a major regulator of melanogenesis. To date, many approaches have been tried to regulate tyrosinase activity and melanin content. To that end, we screened small interfering RNA sequences for sequence-inhibited tyrosinase expression in B16 cells and in C57BL/6 mice. We analyzed tyrosinase mRNA levels by quantitative real-time PCR and determined tyrosinase activity and melanin content at 24, 48, and 72 hours after transfection. Results showed that siNM_011661_001 was the most efficient small interfering RNA sequence in suppressing tyrosinase mRNA expression, and cells transfected with this sequence showed lower tyrosinase activity. Moreover, intravitreous injection of siNM_011661_001 in C57BL/6 mice induced an efficient and stable gene-specific inhibition of expression at the posttranscriptional level.

Role of Caspase-3 in acute light damage to retina of rats / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the role of Caspase-3 in retinal damage caused by light exposure in rats.</p><p><b>METHODS</b>Light injury to retina was induced by persistent exposure to illumination (intensity: 30 000 +/- 50 lux) of operating microscope for 30 minutes in the right eyes of Sprague-Dawley rats. The pathological changes of retina were observed under optical and electron microscopies at different time points, which were 6 hours, 1, 3, 7, and 15 days after the light exposure. Apoptosis of retinal cells was analyzed by flow cytometry. The activity of Caspase-3 was evaluated by using the Caspase-3 assay kit. At the same time, the expression of Caspase-3 protease was determined with Western blot analysis.</p><p><b>RESULTS</b>The examination results of optical and transmission electron microscopes showed that edema of inner and outer segments of the retina, especially the chondriosome inside the inner segment, became obvious 6 hours after the light exposure. The change was deteriorated along with the increasing time. The structures of the discoidal valve dissociated in the outer segment simultaneously. Disorderly arranged nuclei, karyopycnosis, and thinning in the outer nuclear layer were observed. The retinal pigment epithelium almost disappeared during the later stage. The staining results of Annexin-V combined with PI demonstrated that the proportion of apoptotic cells increased with time. The proportion between 7th day (82.7%) and 15th day (80.4%), however, showed no significant difference. Caspase-3 became remarkably active with the lapse of time, which increased from 0.02 at 6th hour to the peak of 9.8 at 7th day before it started to descend. The Western blot detected a expression of the active form of Caspase-3 at 7th day and 15th day.</p><p><b>CONCLUSION</b>Apoptosis of photoreceptor cells is markedly involved in the light damage and Caspase-3 protease may play an important role in the apoptotic process of the retina after light exposure in rats.</p>

Changes of NF-kappaB/I kappa B alpha in N-methyl-N-nitrosourea-induced retinal damage in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the changes of nuclear factor-kappa B (NF-kappaB) in the course of N-methyl-N-nitrosourea (MNU)-induced apoptosis of rat retinal photoreceptor cells and investigate the mechanism of MNU-induced retinal damage.</p><p><b>METHODS</b>A single intraperitoneal injection of 60 mg/kg MNU was given to 50-day-old female rats, which were sacrificed at different intervals after MNU treatment. The retinal damage was examined with optical microscopy and photoreceptor cell apoptosis detected by TUNEL assay. Western blotting was performed to analyze the changes in NF-kappaB.</p><p><b>RESULTS</b>Pyknosis of the photoreceptor cell nuclei and disorientation of the outer segment of the photoreceptor layer was observed 24 h after MNU treatment, and the outer nuclear layer and photoreceptor layer were almost completely lost on day 7. Photoreceptor cell apoptosis peaked at 24 h, and in the apoptotic cascade, NF-kappaB p65 protein was only detected 12 and 24 h after MNU treatment, whereas the amount of I kappa B alpha, in contrast, markedly increased in the cytoplasm as well as in the nuclei.</p><p><b>CONCLUSION</b>MNU-induced retinal damage might be mediated through the signaling pathway of NF-kappaB/I kappa B alpha.</p>

N-methyl-N-nitrosourea-induced apoptosis of photoreceptor cells in Sprague-Dawley rats via nuclear factor-kappaB / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies have showed that photooxidative stress can lead to down-modulation of nuclear factor-kappa B (NF-kappaB) activity causing apoptosis of cultured photoreceptor cells. This study aimed at investigating whether NF-kappaB was involved in photoreceptor cells apoptosis induced by N-methyl-N-nitrosourea (MNU) in rats.</p><p><b>METHODS</b>A single intraperitoneal injection of 60 mg/kg MNU was given to 50-day-old female rats. At different intervals after MNU treatment, the animals were sacrificed. Retinal damage was examined by a light microscope. The apoptotic index of the photoreceptor cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL). NF-kappaB was analysed by Western blot and Transcriptin Factor Assay Kits.</p><p><b>RESULTS</b>The pyknosis of the photoreceptor nuclei and the disorientation of the outer segment of the photoreceptor layer was seen after MNU treatment for 24 hours. The outer nuclear layer and photoreceptor layer were almost completely lost at 7 days. Photoreceptor cells apoptosis reached the peaked value at 24 hours. In apoptotic cascade, the protein levels of NF-kappaB p65 were only detected after MNU treatment for 12 and 24 hours in the nucleus. Conversely, the amounts of IkappaBalpha were markedly increased in the cytoplasm as well as in the nucleus. The activity of NF-kappaB p65 in the nucleus was down-modulated in the end.</p><p><b>CONCLUSIONS</b>MNU-induced photoreceptor cell destruction was attributed to the apoptotic process by down-regulating the activation of NF-kappaB p65.</p>

Protective effects of ligustrazine against photoreceptor cell injury induced by N-methyl-N-nitrosourea and its mechanism / 药学学报

<p><b>AIM</b>To study the protective effect of ligustrazine against photoreceptor cell injury induced by N-methyl-N-nitrosourea (MNU) in Sprague-Dawley (SD) rats.</p><p><b>METHODS</b>Ligustrazine injections of different doses were injected intraperitoneally into 47-day female SD rats once a day and a single intraperitoneal injection of MNU 60 mg x kg(-1) was given to 50-day rats. At different intervals after MNU treatment,the animals were sacrificed. The apoptotic index of photoreceptor cells was calculated by TUNEL labeling at 24 h following MNU treatment; peripheral retinal damage was evaluated based on retinal thickness at the d 7 after MNU treatment, and the expression of c-jun and c-fos genes was detected by RT-PCR technique.</p><p><b>RESULTS</b>Ligustrazine injection could remarkably increase total thickness of peripheral retina and decrease apoptotic index of photoreceptor cells induced by MNU in a dose-dependent manner. Compared with MNU-treated rats, the gene expression of c-jun and c-fos was time-dependently down-regulated in ligustrazine-treated group.</p><p><b>CONCLUSION</b>Ligustrazine injection partially protects against MNU-induced retinal damage by down-modulating the expression of c-jun and c-fos genes to inhibit apoptosis of photoreceptor cells.</p>

PCNA, Bcl-2 and TERT expression in epiretinal membrane of rat traumatic proliferative vitreoretinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

· AIM: To explore the dynamic expression and correlation among telomerase catalytic subunit (TERT), proliferating cell nuclear antigen ( PCNA) and antiapoptosis protein Bd-2 which relate to cell proliferation in epiretinal membrane of rat traumatic proliferative vitreoretinopathy(PVR).· METHODS: S-P technique was applied for immunohistochemical staining of epiretinal membrane of traumatic PVR with TERT, PCNA and Bcl-2 antibody. HE staining was also carried out. The staining results were analyzed with image analysis system.· RESULTS: The positive rate and average A of PCNA protein were upregulated at first and then down-regulated, with the peak value in 14d Group, which was significantly different from those in 7d Group and 28d Group.The positive rate and average A of TERT and Bcl-2 were also upregulated at first and then down-regulated, with the peak value in 14d Group and 21d Group, which were significantly different from those in 7d Group. There was significant correlation among PCNA, Bcl-2 and TERT protein expression (P≤0.01).· CONCLUSTON: TERT and Bcl-2 take part in the regulation of proliferative cells in epiretinal membrane of traumatic proliferative PVR, with high correlation with the dynamic changes of cell proliferation.

Kinetics of Ionizing Irradiation-induced DNA Strand Breaks.

By measuring the dose effect of ionizing irradiation-induced single- and double-strand breaks (SSB and DSB) of pBR322, the responses of the yields of SSB and DSB to DNA concentrations were obtained. It was found that, in the presence of mannitol, the reciprocals of G(SSB) and G(alphaDSB) had a linear relationship to the reciprocal of DNA concentration so that the competition reaction of DNA and mannitol to.OH radicals could be described by a second-order kinetics. Moreover, the rate coefficients and the efficiencies of the.OH radical inducing SSB and alphaDSB were deduced.

Mechanisms of Formation of DNA Strand Breaks Induced by gamma-Rays.

Dose responses of DNA single- and double-strand breaks (SSB and DSB) of pBR322 irradiated with gamma-rays were measured by gel electrophoresis scanning and the production process of SSB was tested. Results showed that the formation of DSB was related to the free radicals scavenging capacity sigma of mannitol dissolved in DNA solution. The ratio of alphaDSB to betaDSB non-linearly increased with increasing sigma. On the other hand alphaDSB was induced by the single radical transfer mechanism as sigma<10(8)s(-1) it could however be formed by the LMDS mechanism as sigma>2x10(8)s(-1). Moreover the distance for two SSBs forming a DSB in complementary strands was not obviously influenced by the scavenging capacity.

Reverse Oxygen Effect on gamma-Irradiation Induced Single Strand Breaks of Plasmid DNA.

Oxygen effect on gamma-irradiation induced single strand breaks (SSB) of plasmid DNA was measured by the method of gel scanning. It was found that, in the presence of mannitol, the yield of SSB in N(2)-saturated DNA solution was larger than that in air-saturated solution so that the oxygen enhancement ratio (OER) of SSB became smaller than 1, which indicates the appearance of reverse oxygen effect of DNA SSB. At the same time, G(SSB) and its OER decreased with increasing concentration of mannitol.

Studies on Etching and Damage Action of Low Energy Ion Beam on icrobial Cells.

The action of 20 keV N(+) ion on Deinococcus radiodurans and E. coli was investigated by means of scanning electron microscope(SEM) and electron spin resonance(ESR). The results showed that ion implantation exerted direct etching damage and indirect free radicals action by energy deposition on the cells of the two microbes. The DNA damage and biological mutation resulted mainly from the etching action of injected ions; the free radicals resulted chiefly in the damage of peroxidation of biological macromolecule and membrane lipids except of DNA. Moreover, the damages in D. radiodurans and E. coli by etching and free radicals action aggravated gradually with increasing doses. The sedimentation patterns of tritiated DNA materials in D. radiodurans by neutral sucrose gradient(50-200 g/L) indicated that DNA sedimentation peak of cells incubated for 4 h did not resume control state after the implantation of 60x10(15) N(+) ions injection per cm(2), proving that the direct action of implanted ions led to DNA damage. The survival rate of the implanted D. radiodurans and E. coli lowered after 2 mol/L caffeine and 0.5 mmol/L EDTA treatment, confirming that the etching action of implanted ions was the direct cause resulting in DNA damage and organism mutation.