Aryl Hydrocarbon Receptor-Mediated Perturbations in Gene Expression during Early Stages of CD4(+) T-cell Differentiation

Activation of the aryl hydrocarbon receptor (AhR) by its prototypic ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), mediates potent suppression of T-cell dependent immune responses. The suppressive effects of TCDD occur early during CD4(+) T-cell differentiation in the absence of effects on proliferation and have recently been associated with the induction of AhR-dependent regulatory T-cells (Treg). Since AhR functions as a ligand-activated transcription factor, changes in gene expression induced by TCDD during the early stages of CD4(+) T-cell differentiation are likely to reflect fundamental mechanisms of AhR action. A custom panel of genes associated with T-cell differentiation was used to query changes in gene expression induced by exposure to 1 nM TCDD. CD4(+) T-cells from AhR(+/+) and AhR(-/-) mice were cultured with cytokines known to polarize the differentiation of T-cells to various effector lineages. Treatment with TCDD induced the expression of Cyp1a1, Cyp1b1, and Ahrr in CD4(+) T-cells from AhR(+/+) mice under all culture conditions, validating the presence and activation of AhR in these cells. The highest levels of AhR activation occurred under Th17 conditions at 24 h and Tr1 conditions at 48 h. Unexpectedly, expression levels of most genes associated with early T-cell differentiation were unaltered by AhR activation, including lineage-specific genes that drive CD4(+) T-cell polarization. The major exception was AhR-dependent up-regulation of Il22 that was seen under all culture conditions. Independent of TCDD, AhR down-regulated the expression of Il17a and Rorc based on increased expression of these genes in AhR-deficient cells across culture conditions. These findings are consistent with a role for AhR in down-regulation of inflammatory immune responses and implicate IL-22 as a potential contributor to the immunosuppressive effects of TCDD.

[Expression of SOX11 mRNA in mantle cell lymphoma and its clinical significance]

OBJECTIVE

To investigate the expression level of SOX11 mRNA in mantle cell lymphoma (MCL) and other B-cell non-Hodgkin lymphoma (B-NHL) and its prognostic value in MCL.

METHODS

The expression level of SOX11 mRNA in 80 B-NHL patients were determined by real-time quantitative RT-PCR, GAPDH was used as internal control. The dispersion of SOX11 expression ratio of groups with different prognostic factors was described by Mann-Whitney U test.

RESULTS

The SOX11 mRNA expression level was 2.90 (0.75 - 4.63) in 80 B-NHL patients, and the expression level was significantly higher in MCL than that in other B-NHL (P = 0.014). The SOX11 expression level was statistically lower in the group of MCL with hyperleukocytosis, 12 trisomy, MYC amplification and therapeutic effect < PR (P = 0.042, 0.013, 0.028, 0.009) than that of MCL in other group. But SOX11 expression was not associated with MCL international prognostic index (MIPI) (P = 0.333), lactate dehydrogenase (LDH) (P = 0.790), ATM mutation (P = 0.865) and P53 deletion (P = 0.116). The progression free survival (PFS) and overall survival (OS) were significantly longer in the MCL patients with high level of SOX11 than that of other MCL patients.

CONCLUSION

There was statistically significant differences in SOX11 mRNA expression between MCL with other B-NHL. SOX11 maybe a good prognostic factor in MCL.

[Expression of B7-H1 gene in leukemia cells and its clinical significance]

This study was purposed to investigate the expression of B7-H1 gene in leukemia cells and its clinical significance. The expression of B7-H1 mRNA was detected by SYBR Green I real-time quantitative PCR in a panel of 9 leukemia cell lines, 4 leukemia cell lines induced with IFN-γ, the bone marrow mononuclear cells (BMMNC) from 59 initial leukemia patients and 10 dendritic cells (DC) derived from BMMNC of initial leukemia patients, 2 solid tumour cell lines and BMMNC from 10 normal persons. The correlation between the clinical features of 59 acute leukemia patients and the expression level of B7-H1 mRNA in leukemia cells was analyzed. The results showed that the lower level of B7-H1 mRNA expression was found in leukemia cell lines and primary acute leukemia cells, but the expression level of B7-H1 mRNA was up-regulated significantly in the leukemia cell lines induced by IFN-γ and DC derived from BMMNC of leukemia patients. The expression level of B7-H1 mRNA in non complete remission (CR) patients after therapy was significantly higher than that in CR patients. It is concluded that the expression level of B7-H1 mRNA in leukemia cells is lower, but is up-regulated when affected by some factors. A correlation exists between the expression level of B7-H1 gene in leukemia cells and response of patients to therapy.

[Research progress on plate mixed culture of lignocellulolytic microorganisms]

Mixed culture of microorganisms has been widely used for the research of lignocellulose transformation and degradation, but the results of the mixed culture are largely affected by the interactions of different lignocellulolytic microorganisms. At present, the researches on these interactions are mainly based on plate mixed culture assay. For this assay, two types of plate were used, namely, basic medium plate and improved medium plate. The basic medium plate is mainly used for the study of colony morphology, mycelia color, exocellular volatile organic compounds, and exocellular enzyme activity, whereas the improved medium plate is used for comparative study, with the carbon sources replaced by natural lignocelloses. This paper summarized the present research status and advancement about the plate mixed culture of lignocellulolytic microorganisms, and put forward a prospect about the focuses of future research in this field.

Mitochondrial distribution of neuroglobin and its response to oxygen-glucose deprivation in primary-cultured mouse cortical neurons

Neuroglobin (Ngb) is a new member of the globin family and a novel endogenous neuroprotective molecule, but its neuroprotective mechanisms remain largely undefined. Previous studies suggest Ngb is both physically and functionally related to mitochondria, however without direct evidence. Our recent discovery has shown that Ngb can physically interact with a number of mitochondrial proteins. In this study we aimed to define the physical interaction between Ngb and mitochondria by determining whether there is a mitochondrial distribution of Ngb under both physiological-resting and pathological oxygen-glucose deprivation (OGD) conditions. Western blot for the first time revealed a small portion of Ngb was physically localized in mitochondria, and the relative mitochondrial Ngb level was significantly increased after OGD in primary-cultured mouse cortical neurons, indicating a translocation of Ngb into mitochondria. Complementary approaches including confocal imaging and immuno-electron microscopy confirmed Ngb distribution in mitochondria under both basal-resting condition and OGD. Inhibitors of mitochondria permeability transition pore (mPTP) and Voltage-Dependent Anion Channel (VDAC) blocked OGD-induced increase of mitochondrial Ngb level, demonstrating a possible role of mPTP in Ngb's mitochondrial translocation. We further found that Ngb overexpression-conferred neuroprotection was correlated with increased mitochondrial Ngb level, suggesting the mitochondria distribution of Ngb is clearly associated with and may contribute to Ngb's neuroprotection.

[Regulation of miRNA-15a/-16 expression on the drug resistance of myeloma cells]

OBJECTIVE

To explore the effects and mechanism of bone marrow stromal cells (BMSCs) on the drug resistance of multiple myeloma (MM).

METHODS

Fresh untreated MM patient (5 samples) and health donor (5 samples) bone marrow samples were collected from May 2011 to July 2011 at our hospital. Their BMSCs were separated respectively. The supernatant expression of cytokines in BMSCs was detected by enzyme-linked immunosorbent assay (ELISA). Myeloma cells were co-cultured with BMSCs and treated with melphalan or bortezomib. Cell proliferation and miRNA-15a/-16 expression of myeloma cells were measured in different culture conditions with thiazoyl blue tetrazolium bromide (MTT) assay and quantitative real-time PCR (qRT-PCR). miRNA-15a was transfected into myeloma cells. And the miRNA-15a functions on cell cycle and cell apoptosis were detected by flow cytometry.

RESULTS

ELISA assay showed that cytokine IL-6 and VEGF were at higher levels in MM-BMSCs than healthy BMSCs ((189 ± 9) vs (115 ± 15) pg/ml, (1497 ± 40) vs (1239 ± 21) pg/ml, both P < 0.05). The miRNA-15a/-16 expressions of myeloma cells were up-regulated after the treatment of melphalan and bortezomib (all P < 0.05). However, the miRNA-15a/-16 up-regulation by melphalan or bortezomib became inhibited when MM cells were co-cultured with MM-BMSCs (melphalan: 4.690 ± 0.050 vs 34.440 ± 4.100, 0.760 ± 0.070 vs 12.030 ± 1.020, bortezomib: 1.440 ± 0.230 vs 11.480 ± 1.488, 0.880 ± 0.040 vs 3.680 ± 0.420, all P < 0.05). Furthermore, IL-6 suppressed the expression of miRNA-15a/-16 in a dose and time-dependent pattern. The transfection of miRNA-15a led to the arrest of MM cell cycle in G(1)/S phase.

CONCLUSIONS

BMSCs suppress the proliferation of myeloma cells and regulate the drug sensitivity of myeloma cells through the inhibited expression of miRNA-15a/-16. IL-6 plays a pivotal role in the occurrence of drug resistance.

Vitamin D receptor gene polymorphisms and colorectal cancer risk: a systematic meta-analysis

AIM

To investigate the relationship between polymorphisms present in the vitamin D receptor (VDR) gene and colorectal cancer risk, a systematic meta-analysis of population-based studies was performed.

METHODS

A total of 38 relevant reports published between January 1990 and August 2010 were identified, of which only 23 qualified for this meta-analysis based on our selection criteria. Five polymorphic variants of the VDR gene, including Cdx-2 (intron 1e) and FokI (exon 2) present in the 5' region of the gene, and BsmI (intron 8), ApaI (intron 8), and TaqI (exon 9) sites present in the 3' untranslated region (UTR), were evaluated for possible associations with colorectal cancer risk. Review manager 4.2 was used to perform statistical analyses.

RESULTS

In the meta-analysis performed, only the BsmI polymorphism was found to be associated with colorectal cancer risk. In particular, the BsmI B genotype was found to be related to an overall decrease in the risk for colorectal cancer [BB vs bb: odds ratio (OR) = 0.87, 95% CI: 0.80-0.94, P = 3 × 10(-4); BB vs Bb + bb: OR = 0.90, 95% CI: 0.84-0.97, P = 5 × 10(-4)]. Moreover, in subgroup analyses, the BsmI B genotype was significantly associated with colon cancer, and not rectal cancer. An absence of between-study heterogeneity was also observed.

CONCLUSION

A meta-analysis of 23 published studies identified the BsmI polymorphism of the VDR gene to be associated with an increased risk of colon cancer.

Meta-analysis of the effectiveness of prophylactic antibiotics in the prevention of postoperative complications after tension-free hernioplasty

BACKGROUND

Previous reviews of the effectiveness of antibiotic prophylaxis for elective inguinal hernia repair were not conclusive owing to the limited number of patients enrolled in randomized controlled trials (RCTs). However, since new RCTs involving patients undergoing tention-free hernioplasty have been published in recent years, we performed a new meta-analysis to evaluate the effectiveness of antibiotic prophylaxisin the prevention of postoperative complications after this procedure.

METHODS

We performed a meta-analysis of RCTs studying the use of antibiotic prophylaxis to prevent postoperative complications in patients undergoing tension-free hernioplasty.

RESULTS

We included 6 RCTs conducted around the world in our analysis. Compared with the control condition, antibiotic prophylaxis was associated with a lower incidence of incision infection (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.26-0.77, p = 0.004). There were no significant differences in risk for incision hematoma (OR 1.57, 95% CI 0.60-4.10, p = 0.35), respiratory infection (OR 1.00, 95% CI 0.17-5.79, p > 0.99) or urinary tract infection (OR 1.81, 95% CI 0.38-8.52, p = 0.45) between the 2 conditions.

CONCLUSION

Antibiotic prophylaxis use in patients undergoing tension-free hernioplasty decreases the rate of incision infection by 55%.

Impact of phenylephrine administration on cerebral tissue oxygen saturation and blood volume is modulated by carbon dioxide in anaesthetized patients

BACKGROUND

Multiple studies have shown that cerebral tissue oxygen saturation (Sct(O(2))) is decreased after phenylephrine treatment. We hypothesized that the negative impact of phenylephrine administration on Sct(O(2)) is affected by arterial blood carbon dioxide partial pressure (Pa(CO(2))) because CO(2) is a powerful modulator of cerebrovascular tone.

METHODS

In 14 anaesthetized healthy patients, i.v. phenylephrine bolus was administered to increase the mean arterial pressure ~20-30% during hypocapnia, normocapnia, and hypercapnia. Sct(O(2)) and cerebral blood volume (CBV) were measured using frequency domain near-infrared spectroscopy, a quantitative technology. Data collection occurred before and after each treatment.

RESULTS

Phenylephrine caused a significant decrease in Sct(O(2)) during hypocapnia [ΔSct(O(2)) =-3.4 (1.5)%, P<0.001], normocapnia [ΔSct(O(2)) =-2.4 (1.5)%, P<0.001], and hypercapnia [ΔSct(O(2)) =-1.4 (1.5)%, P<0.01]. Decreases in Sct(O(2)) were significantly different between hypocapnia, normocapnia, and hypercapnia (P<0.001). Phenylephrine also caused a significant decrease in CBV during hypocapnia (P<0.01), but not during normocapnia or hypercapnia.

CONCLUSION

The negative impact of phenylephrine treatment on Sct(O(2)) and CBV is intensified during hypocapnia while blunted during hypercapnia.

On the role of β-cyanoalanine synthase (CAS) in metabolism of free cyanide and ferri-cyanide by rice seedlings

A study was conducted to investigate the contribution of β-cyanoalanine synthase (CAS) to the botanical metabolism of free cyanide and iron cyanides. Seedlings of rice (Oryza sativa L. cv. XZX 45) were grown hydroponically and then amended with free cyanide (KCN) or ferri-cyanide [K(3)Fe(CN)(6)] into the growth media. Total cyanide, free cyanide, and Fe(3+)/Fe(2+) in aqueous solution were analyzed to identify the speciation of K(3)Fe(CN)(6). Activity of CAS in different parts of the rice seedlings was also assayed in vivo and results indicated that dissociation of K(3)Fe(CN)(6) to free cyanide in solution was negligible. Almost all of the applied KCN was removed by rice seedlings and the metabolic rates were concentration dependent. Phyto-transport of K(3)Fe(CN)(6) was apparent, but appreciable amounts of cyanide were recovered in plant tissues. The metabolic rates of K(3)Fe(CN)(6) were also positively correlated to the concentrations supplied. Rice seedlings exposed to KCN showed a considerable increase in the CAS activity and roots had higher CAS activity than shoots, indicating that CAS plays an important role in the botanical assimilation of KCN. However, no measurable change of CAS activity in different parts of rice seedlings exposed to K(3)Fe(CN)(6) was detected, suggesting that K(3)Fe(CN)(6) is likely metabolized by rice directly through an unknown pathway rather than the β-cyanoalanine pathway.

MicroRNA-223 expression is uniformly down-regulated in B cell lymphoproliferative disorders and is associated with poor survival in patients with chronic lymphocytic leukemia

MicroRNA-223 (miR-223) expression has been demonstrated to be stage-specific in B cell differentiation and associated with the outcome of chronic lymphocytic leukemia (CLL). However, the expression pattern of miR-223 in B cell lymphoproliferative disorders and its association with the outcome of Chinese patients with CLL have not been investigated. In this study, we demonstrated that miR-223 expression was significantly decreased in CLL, mantle cell lymphoma (MCL) and splenic marginal zone lymphoma (SMZL). In CLL, miR-223 expression decreased significantly with progression from early to advanced clinical stages and was significantly lower in patients with elevated β(2)-microglobulin, unmutated immunoglobulin variable heavy chain (IgVH) gene or with disease progression or death. Using a cut-off determined by receiver operating characteristic (ROC) analysis optimizing concordance with IgVH mutational status, miR-223-negative and -positive groups were defined for 22 and 31 patients, respectively. The median progression-free survival (PFS) and overall survival of the miR-223-negative group were 13 and 40 months, respectively, significantly shorter than for the miR-223-positive group (both not reached; p = 0.002 and p = 0.018, respectively). Multivariate analysis revealed that the absence of miR-223 was the only independent factor capable of predicting shorter PFS. In conclusion, miR-223 is uniformly down-regulated in B-LPDs and is a useful prognostic factor for patients with CLL.

[Expression of stereotyped B-cell receptor and its clinical value in chronic lymphocytic leukemia]

OBJECTIVE

To investigate the expression pattern of stereotyped B-cell receptor (BCR) and its prognostic significance in Chinese chronic lymphocytic leukemia (CLL) patients and evaluate the relationship to other prognostic markers.

METHODS

Multiplex polymerase chain reaction (PCR) was used to identify the immunoglobulin variable heavy-chain (IGHV) segment and its mutation status in 116 CLL patients from April 1992 to April 2010. For CDR3-driven clustering, all in-frame IGHV-D-J rearrangements were aligned by the multiple sequence alignment software ClustalW2.

RESULTS

There were 102 of 116 samples from newly diagnosed CLL were successfully analyzed. IGHV CDR3 genes were identified in 73/102 cases. Fourteen patients (19.2%) carried stereotyped BCR. A high percentage of carried stereotyped BCR was observed in IGHV non-mutated group versus mutated group (40.9% vs 11.8%, P = 0.005). Patients with stereotyped BCR had a higher frequency of deletion (17q) (33.3% vs 10.7%, P = 0.045). The median progression-free survival (PFS) in patients with stereotyped BCR was much shorter than other patients (39 vs 84 months, P = 0.002).

CONCLUSION

The patients with stereotyped BCR have a poor prognosis. It highlights the importance of immunoglobulin mediated stimulation in the development of CLL.

[Study on characteristics of energy metabolism in skeletal muscle of rats with postoperative fatigue syndrome and interventional effect of ginsenoside Rb1]

OBJECTIVE

To study characteristics of energy metabolism in the skeletal muscle of rats with postoperative fatigue syndrome (POFS) and the interventional effect of ginsenoside Rb1.

METHOD

We chose resection of 70% of the "middle" small intestine as the rat model for POFS. Ninety-six adult male SPF SD rats were randomly divided into the control group, the model group, and the ginsenoside Rb1-treated group by body weight. And then, each group was further randomly divided into four subgroups, according to different postoperative investigated time points, such as postoperative day 1, postoperative day 3, postoperative day 7 and postoperative day 10. So the animals were divided into twelve subgroups (n = 8 in each subgroup). Rats of the control group and the model group were injected intraperitoneally with saline at the dose of 10 mL x kg(-1) one hour before the operation and once a day during the postoperative days. Rats of the ginsenoside Rb1-treated group were administered 10 mg x kg(-1) ginsenoside Rb1 by the same method. The skeletal muscles were sampled on postoperative day 1, 3, 7 and 10. The contents of ATP, ADP, AMP in skeletal muscles were determined by HPLC, and the activities of Na(+)-K(+)-ATPase and Ca(2+)-ATPase were investigated by colorimetry.

RESULT

Compared with the control group, the content of ATP in skeletal muscle of rats of the model group decreased significantly on postoperative day 3 (P < 0.05), while the content of ADP significantly increased on postoperative day 7 and 10 (P < 0.05). The activity of Na(+)-K(+)-AT-Pase decreased on postoperative day 3 and 7 (P < 0.05), and the activity of Ca(2+)-ATPase decreased on postoperative day 7. After supplement of ginsenoside Rb1, on the investigated time points, all the negative changes of the indicators discovered above were significantly adjusted (P < 0.05) in rats of the ginsenoside Rb1-treated group, while no significant differences were investigated.

CONCLUSION

During a certain period of postoperative time, the activity of energy metabolism is depressed in the skeletal muscle of rats with POFS, but it can be improved by supplement of ginsenoside Rb1.

[Association of the changes of central serotonin and peripheral blood free amino acids with postoperative fatigue after abdominal surgery]

OBJECTIVE

To explore the mechanism of postoperative fatigue syndrome(POFS) by detecting the change of central monoamine neurotransmitters in a rat model after major abdominal surgery.

METHOD

Eighty-four rats were randomly divided into fatigue assessment groups (including model group and sham group) and experimental groups (including postoperative day 1, 3, 5, 7, and 14 recovery groups and the corresponding control groups). Postoperative fatigue was evaluated after surgery. The brains were removed thereafter to detect the levels of 5-hydroxytryptamine (5-HT), norepinephrine (NE), dopamine (DA) in the hippocampus, midbrain, hypothalamus by high performance liquid chromatography. Serum free tryptophan (f-Trp) and branched-chain amino acids (BCAA) were measured.

RESULTS

The level of 5-HT increased to the highest at postoperative day 3, but reduced rapidly to the minimum at postoperative day 5, and then gradually recovered to the preoperative level. There was significant difference of 5-HT among experimental groups (P<0.05), also between the postoperative 24 hrs group and control groups (P<0.05). f-Trp and the ratio of f-Trp/BCAA increased in the early postoperative period, reduced to minimum at postoperative day 5. f-Trp was still lower compared to the control group at postoperative day 14, while the ratio of f-Trp/BCAA and BCAA restored to control level. Both of them were significantly different among experimental groups (P<0.05), also between the experimental groups and control groups (P<0.05).

CONCLUSION

Changes of f-Trp, the ratio of f-Trp/BCAA, and central 5-HT may play an important role in the development of POFS.

Identification of neuroglobin-interacting proteins using yeast two-hybrid screening

Neuroglobin (Ngb) is a globin protein that is highly and specifically expressed in brain neurons. A large volume of evidence has proven that Ngb is a neuroprotective molecule against hypoxic/ischemic brain injury and other related neurological disorder; however, the underlying mechanisms remain poorly understood. Aiming to provide more clues in understanding the molecular mechanisms of Ngb's neuroprotection, we performed yeast two-hybrid screening to search for proteins that interact with Ngb. From a mouse brain cDNA library, we found totally 36 proteins that potentially interact with Ngb, and 10 of them were each identified in multiple positive clones. The shared sequences within these multiple clones are more likely to be Ngb-interacting domains. In primary cultured mouse cortical neurons, immuno-precipitation was performed to confirm the interactions of selected proteins with Ngb. The discovered Ngb-interacting proteins in this study include those involved in energy metabolism, mitochondria function, and signaling pathways for cell survival and proliferation. Our findings provide molecular targets for investigating protein interaction-based biological functions and neuroprotective mechanisms of Ngb.

Establishment and assessments of a new model for the postoperative fatigue syndrome by major small intestinal resection in rats

OBJECTIVE

Postoperative fatigue syndrome (POFS) is a general and main complication after surgery. However, there is no stable and standardized animal model for POFS. The aim of the present study was to establish a rodent model of POFS by small intestinal resection, with POFS evaluated by acknowledged physical and behavioral methods.

MATERIAL AND METHODS

Forty-two Sprague-Dawley rats were randomly divided into four groups according to the length of a "middle" small intestinal resection: 0% (sham group; i.e., laparotomy alone), 10%, 40% and 70% groups, with corresponding lengths of small intestinal resections. Following surgery, the general state of health was evaluated. Tail suspension test, open field test and Morris water maze test were used to evaluate the degree of POFS. Serum albumin, transferrin, prealbumin and fibronectin were measured to assess the nutritional status, and superoxide dismutase (SOD) and malondialdehyde (MDA) were also measured.

RESULTS

As compared with the other three groups, the 70% small intestinal resection group showed the worst general state of health, decreased strength of the tail suspension test and decreased score of Morris water maze test (p < 0.05) after operation. All rats in whom the small intestinal resection was done demonstrated a certain degree of malnutrition and behavior of depression, and the 70% resection group had the lowest levels of transferrin, prealbumin and fibronectin as compared with the other groups (p < 0.05), as well as decreased SOD and increased MDA in serum (p < 0.05).

CONCLUSIONS

Resection of 70% of the small intestine resulted in typical characteristics of POFS. As this procedure is simple, stable and easily reproducible, it may serve as a model for research on POFS.

Promoter de-methylation of cyclin D2 by sulforaphane in prostate cancer cells

Sulforaphane (SFN), an isothiocyanate derived from cruciferous vegetables, induces potent anti-proliferative effects in prostate cancer cells. One mechanism that may contribute to the anti-proliferative effects of SFN is the modulation of epigenetic marks, such as inhibition of histone deacetylase (HDAC) enzymes. However, the effects of SFN on other common epigenetic marks such as DNA methylation are understudied. Promoter hyper-methylation of cyclin D2, a major regulator of cell cycle, is correlated with prostate cancer progression, and restoration of cyclin D2 expression exerts anti-proliferative effects on LnCap prostate cancer cells. Our study aimed to investigate the effects of SFN on DNA methylation status of cyclin D2 promoter, and how alteration in promoter methylation impacts cyclin D2 gene expression in LnCap cells. We found that SFN significantly decreased the expression of DNA methyltransferases (DNMTs), especially DNMT1 and DNMT3b. Furthermore, SFN significantly decreased methylation in cyclin D2 promoter regions containing c-Myc and multiple Sp1 binding sites. Reduced methlyation of cyclin D2 promoter corresponded to an increase in cyclin D2 transcript levels, suggesting that SFN may de-repress methylation-silenced cyclin D2 by impacting epigenetic pathways. Our results demonstrated the ability of SFN to epigenetically modulate cyclin D2 expression, and provide novel insights into the mechanisms by which SFN may regulate gene expression as a prostate cancer chemopreventive agent.

Quantitative assessment of chronic lung disease of infancy using computed tomography

The aims of this study were to determine whether infants and toddlers with chronic lung disease of infancy (CLDI) have smaller airways and lower lung density compared with full-term healthy controls. Multi-slice computed tomography (CT) chest scans were obtained at elevated lung volumes during a brief respiratory pause in sedated infants and toddlers; 38 CLDI were compared with 39 full-term controls. For CLDI subjects, gestational age at birth ranged from 25 to 29 weeks. Airway size was measured for the trachea and the next three to four generations into the right lower lobe; lung volumes and tissue density were also measured. The relationship between airway size and airway generation differed between the CLDI and full-term groups; the sizes of the first and second airway generations were larger in the shorter CLDI than in the shorter full-term subjects. The increased size in the airways in the CLDI subjects was associated with increasing mechanical ventilation time in the neonatal period. CLDI subjects had a greater heterogeneity of lung density compared with full-term subjects. Our results indicate that quantitative analysis of multi-slice CT scans at elevated volumes provides important insights into the pulmonary pathology of infants and toddlers with CLDI.