Effects of Ambient Particulate Matter on Human Breast Cancer: Is Xenogenesis Responsible?

Background

Recently, evidence from several studies has revealed that air pollution is associated with the increased morbidity and mortality of breast cancer patients. However, to date, the underlying mechanism remains largely unclear. Considering the high prevalence of air pollution and breast cancer in China, it is necessary to understand how air pollution may affect breast cancer.

Methods

We analyzed 1,832 female patients who had resided in the same cities for at least 10 years prior to their diagnosis. Variables including demographic data as well as clinical and tumor characteristics, including the patient’s age at menarche, family history of breast cancer, tumor histopathological type, tumor size, lymph node metastasis, distant metastasis, histological grade, estrogen receptor (ER) status, progesterone receptor (PR) status and human epidermal growth factor receptor 2 (HER-2) status at the time of diagnosis were analyzed.

Results

Compared to patients residing in low-pollution areas, patients living in high-pollution areas demonstrated a younger age at menarche (p<0.001), a greater family history of breast cancer (p = 0.034) and more invasive cancers (p = 0.028) with higher tumor grades (p = 0.028) and estrogen receptor (ER)-positive status (p = 0.022). Differences in tumor grade were only found in ER-positive cases.

Conclusions

Our findings and clinical data indicate that long-term air pollution exposure may contribute to the development of breast cancer by playing the role of a xenoestrogen, and also provides new insight into the association between air pollution and the morbidity and mortality of breast cancer patients. Furthermore, it is urgently necessary to study the association between air pollution and breast cancer to improve the living quality and health of females, and applicable public health strategies may need to be established or modified as soon as possible.     

Amplitude of Low Frequency Fluctuation Abnormalities in Adolescents with Online Gaming Addiction

The majority of previous neuroimaging studies have demonstrated both structural and task-related functional abnormalities in adolescents with online gaming addiction (OGA). However, few functional magnetic resonance imaging (fMRI) studies focused on the regional intensity of spontaneous fluctuations in blood oxygen level-dependent (BOLD) during the resting state and fewer studies investigated the relationship between the abnormal resting-state properties and the impaired cognitive control ability. In the present study, we employed the amplitude of low frequency fluctuation (ALFF) method to explore the local features of spontaneous brain activity in adolescents with OGA and healthy controls during resting-state. Eighteen adolescents with OGA and 18 age-, education- and gender-matched healthy volunteers participated in this study. Compared with healthy controls, adolescents with OGA showed a significant increase in ALFF values in the left medial orbitofrontal cortex (OFC), the left precuneus, the left supplementary motor area (SMA), the right parahippocampal gyrus (PHG) and the bilateral middle cingulate cortex (MCC). The abnormalities of these regions were also detected in previous addiction studies. More importantly, we found that ALFF values of the left medial OFC and left precuneus were positively correlated with the duration of OGA in adolescents with OGA. The ALFF values of the left medial OFC were also correlated with the color-word Stroop test performance. Our results suggested that the abnormal spontaneous neuronal activity of these regions may be implicated in the underlying pathophysiology of OGA.     

Post-Mastectomy Radiotherapy for Breast Cancer Patients with T1-T2 and 1-3 Positive Lymph Nodes: a Meta-Analysis

Background

The role of post-mastectomy radiotherapy (PMRT) in patients with T1-2 and 1-3 positive lymph nodes remains controversial. The aim of this study is to investigate the possible benefits of PMRT for this subgroup.

Methods

Three electronic databases were systematically quarried (Cochrane Library, MEDLINE, and EMBASE) for published studies evaluating the effects of PMRT on breast cancer patients with T1-T2 tumors with 1-3 positive lymph nodes. Of the 334 studies identified, information was available for 3432 patients from 10 clinical studies. Pooled relative risk estimates (RR) and overall survival (OS) were calculated using the inverse variance weighted approach, publication bias and chi-square test were also calculated.

Results

From the 10 studies, the pooled RR (RRs) for locoregional recurrence (LRR) with PMRT was 0.348 (95% CI = 0.254 to 0.477), suggesting a significant benefit for PMRT to decrease the risk of LRR in patients with T1-T2 tumors and 1-3 positive nodes (p<0.05). Reporting bias ( Begg’s p = 0.152; Egger’s p = 0.107) or significant heterogeneity (Cochran’s p = 0.380; I² = 6.7%) were not detected. For further subset analysis, the RR for T1, N1-3+ tumors was 0.330 (95% CI = 0.171 to 0.639); for T2, N1-3+ tumors the RR was 0.226 (95% CI = 0.121 to 0.424). The pooled RR for overall survival (OS) was not significantly different between PMRT and no-PMRT group (1.051, 95% CI =1.001 to 1.104).

Conclusions

Our pooled analysis revealed that PMRT significantly reduces the risk of LRR in patients with TI-T2 tumors with 1-3 positive nodes, and the magnitude of the LRR risk reduction is slightly greater for larger tumors. Our results suggest that PMRT should be considered for patients with T1/T2 tumors with 1-3 positive nodes to decrease the relatively high risk of LRR.     

The Role of RING Box Protein 1 in Mouse Oocyte Meiotic Maturation

RING box protein-1 (RBX1) is an essential component of Skp1-cullin-F-box protein (SCF) E3 ubiquitin ligase and participates in diverse cellular processes by targeting various substrates for degradation. However, the physiological function of RBX1 in mouse oocyte maturation remains unknown. Here, we examined the expression, localization and function of RBX1 during mouse oocyte meiotic maturation. Immunofluorescence analysis showed that RBX1 displayed dynamic distribution during the maturation process: it localized around and migrated along with the spindle and condensed chromosomes. Rbx1 knockdown with the appropriate siRNAs led to a decreased rate of first polar body extrusion and most oocytes were arrested at metaphase I. Moreover, downregulation of Rbx1 caused accumulation of Emi1, an inhibitor of the anaphase-promoting complex/cyclosome (APC/C), which is required for mouse meiotic maturation. In addition, we found apparently increased expression of the homologue disjunction-associated protein securin and cyclin B1, which are substrates of APC/C E3 ligase and need to be degraded for meiotic progression. These results indicate the essential role of the SCF^βTrCP-EMI1-APC/C axis in mouse oocyte meiotic maturation. In conclusion, we provide evidence for the indispensable role of RBX1 in mouse oocyte meiotic maturation.     

Morphological variation versus genetic divergence: a taxonomic implication for Mogannia species (Cicadidae: Cicadinae)

Species showing intraspecific morphological variation tend to be very difficult to identify using morphological characters. One such example is the cicada genus Mogannia where some species show considerable intraspecific variation mainly exhibited by wing pattern and body colouration. Thirty-one variants covering different putative species of Mogannia were recognized and illustrated in the present paper. Molecular data of mitochondrial COI and Cytb sequences were employed to test the level of variation and phylogeny of them. The existence of a ‘barcoding gap’ between intraspecific and interspecific genetic divergences and the reciprocally monophyletic clades indicate that all the closely related variants represent a single species, and that all these variants correspond to six species, respectively. However, the evolutionary relationships of intraspecific variants are not resolved possibly due to insufficient genetic variation among them. Our results indicated that some morphological characters, especially the wing pattern and body colouration, and even the number of apical processes of the aedeagus in a couple of related species, must be used with great caution in delimiting Mogannia species and their relatives. The factors responsible for intraspecific morphological variation and phylogeny of Mogannia spp. are preliminarily discussed.     

PTPN4 negatively regulates CrkI in human cell lines

PTPN4 is a widely expressed non-receptor protein tyrosine phosphatase. Although its overexpression inhibits cell growth, the proteins with which it interacts to regulate cell growth are unknown. In this study, we identified CrkI as a PTPN4-interacting protein using a yeast two-hybrid, and confirmed this interaction using in vitro GST pull-down and co-immunoprecipitation and co-localization assays. We further determined the interactional regions as the SH3 domain of CrkI and the proline-rich region between amino acids 462 and 468 of PTPN4. Notably, overexpression of PTPN4 inhibits CrkI-mediated proliferation and wound healing of HEK293T cells, while knockdown of PTPN4 by siRNA in Hep3B cells enhances CrkI-mediated cell growth and motility. Moreover, our data show that ectopic expression of PTPN4 reduces the phosphorylation level of CrkI in HEK293T cells. These findings suggest that PTPN4 negatively regulates cell proliferation and motility through dephosphorylation of CrkI.     

New method to measure coronary velocity and coronary flow reserve

Coronary flow reserve (CFR) is an important index of coronary microcirculatory function. The objective of this study was to validate the reproducibility and accuracy of intravascular conductance catheter-based method for measurements of baseline and hyperemic coronary flow velocity (and hence CFR). The absolute coronary blood velocity was determined by measuring the time of transit of a saline injection between two pairs of electrodes (known distance) on a conductance catheter during a routine saline injection without the need for reference flow. In vitro validation was made in the velocity range of 5 to 70 cm/s in reference to the volume collection method. In 10 swine, velocity measurements were compared with those from a flow probe in coronary arteries at different CFR attained by microsphere embolization. In vitro, the mean difference between the proposed method and volume collection was 0.7 ± 1.34 cm/s for steady flow and -0.77 ± 2.22 cm/s for pulsatile flow. The mean difference between duplicate measurements was 0 ± 1.4 cm/s. In in vivo experiments, the flow (product of velocity and lumen cross-sectional area that is also measured by the conductance catheter) was determined in both normal and stenotic vessels and the mean difference between the proposed method and flow probe was -1 ± 12 ml/min (flow ranged from 10 to 130 ml/min). For CFR, the mean difference between the two methods was 0.06 ± 0.28 (range of 1 to 3). Our results demonstrate the reproducibility and accuracy of velocity and CFR measurements with a conductance catheter by use of a standard saline injection. The ability of the combined measurement of coronary lumen area (as previously validated) and current velocity and CFR measurements provides an integrative diagnostic tool for interventional cardiology.     

NOB1在食管鳞状细胞癌中的表达及临床意义

目的研究NOB1基因在食管鳞状细胞癌（Esophageal squamous cell carcinoma,ESCC）中的表达及临床意义。方法利用免疫组织化学SP法检测59例ESCC及其相应（50例）的远端正常食管黏膜组织中NOB1的表达。结果 ESCC中NOB1的阳性率为71%,正常食管黏膜鳞状上皮中的阳性率为26%,两组比较,差异有统计学意义（P〈0.05）。NOB1的表达与ESCC的分化程度及淋巴结转移相关,与患者的性别,年龄以及肿瘤浸润深度无关。结论 NOB1在ESCC中表达升高,可能在ESCC发生发展过程中起重要作用。     

脱细胞羊膜与小肠黏膜下层促进大鼠皮肤缺损修复和血管形成

目的观察脱细胞羊膜(HAM)与小肠黏膜下层(SIS)促进大鼠皮肤缺损修复和血管形成的作用。方法SD大鼠24只,在两侧背部各做1个直径为1.8cm圆形全层皮肤缺损。创面随机分为A组、B组和C组。A组HAM覆盖,B组SIS覆盖,C组纱布覆盖。在2周时处死动物取材,HE染色观察皮肤缺损修复情况。免疫组织化学染色检测K19和VEGF,RT-PCR检测VEGF mRNA的表达。结果A组、B组愈合较好。C组愈合较差。免疫组织化学染色显示,A、B组K19、VEGF阳性细胞显著多于C组,其中A组最多;RT-PCR结果显示,A、B组比C组表达更多的VEGF mRNA其中A组最多,差异显著,有统计学意义(P<0.05)。结论HAM和SIS均能增加皮肤创面组织中K19阳性细胞数,上调VEGF mRNA的表达、增加VEGF的分泌,其中HAM具有更强的促进皮肤缺损修复和血管形成作用。     

Donor cell type can influence the epigenome and differentiation potential of human induced pluripotent stem cells

We compared bona fide human induced pluripotent stem cells (iPSCs) derived from umbilical cord blood (CB) cells and neonatal keratinocytes (K). As a consequence of both incomplete erasure of tissue-specific methylation and aberrant de novo methylation, CB-iPSCs and K-iPSCs were distinct in genome-wide DNA methylation profiles and differentiation potential. Extended passage of some iPSC clones in culture did not improve their epigenetic resemblance to embryonic stem cells, implying that some human iPSCs retain a residual 'epigenetic memory' of their tissue of origin.