Changed expression of microRNAs may predict postoperative atrial fibrillation in patients with cardiac surgery

OBJECTIVE

Changes of microRNAs (miRNAs) may contribute to the pathogenesis and progression of postoperative atrial fibrillation (POAF) in patients undergoing cardiac valve surgery. This study aimed to measure the expression levels of miRNAs in peripheral blood, as well as their target mRNAs, in POAF patients and normal controls (non-POAF), and to evaluate the potential of miRNAs as promising biomarkers to predict POAF.

PATIENTS AND METHODS

The expression of miRNAs in peripheral blood, including miR-27b, miR-133a, miR-328, miR-499 and their target mRNAs, was analyzed in 109 POAF patients and 96 non-POAF patients via quantitative real-time polymerase chain reaction (RT-PCR). We compared differences between the two groups and also analyzed the treat reaction to amiodarone.

RESULTS

All miRNAs in POAF patients were significantly highly expressed. Compared to non-POAF, the expression of miR-27b, miR-133a, miR-328, miR-499 increased in both groups of POAF patients, and miR-499 was the only upregulated miRNAs in the amiodarone - group versus amiodarone + group and non-POAF. Among the upregulated miRNAs, miR-499 expression significantly changed in amiodarone + and amiodarone - patients (p = 0.005). The ROC curve analysis revealed that miR-499 might be a potential therapeutic response biomarker. The miRNA-mRNA interactions revealed 10 mRNAs regulated by miR-27b, miR-133a, and miR- 499.

CONCLUSIONS

We found an expression on miR-133a, miR-27b, miR-328, and miR-499 was significantly different between these groups, with a high expression being observed in POAF patients compared to non-POAF patients. Further, the present results showed that miR-499 was significantly upregulated in amiodarone - patients, compared to non-POAF, and amiodarone + patients. This finding indicates that miR-499 may be a potential biomarker for predicting the occurrence of POAF after cardiac valve surgery and treat the reaction to amiodarone.

SK2 channel deletion reduces susceptibility to bupivacaine-induced cardiotoxicity in mouse

Bupivacaine is frequently used for regional anesthesia and postoperative analgesia. However, an inadvertent intravenous injection can cause severe cardiotoxicity, manifesting as arrhythmia, hypotension, and even cardiac asystole. The mechanism of bupivacaine-mediated cardiotoxicity remains unclear. SK2 knockout mice (SK) and wild-type mice (WT) were divided into four groups, with 12 mice per group. We determined the difference in bupivacaine cardiotoxicity between SK2 knockout and WT mice by measuring the time to the first arrhythmia (T_arrhythmia) and the time to asystole (T_asystole). Secondary indicators of cardiotoxicity were the time from the beginning of bupivacaine infusion to 20% prolongation of the QT interval (T_QT) and the time to 20% widening of the QRS complex (T_QRS). T_arrhythmia and T_asystole were significantly longer in the SK-bupi group than in the WT-bupi group (both P < 0.05). T_QT and T_QRS were longer in the SK-bupi group than in the WT-bupi group (all P < 0.05). The time to 25%, 50%, and 75% reduction in HR in the SK-bupi group was significantly longer than in the WT-bupi group (all P < 0.05). Knocking out the SK2 channel can reduce bupivacaine-induced cardiotoxicity in the mouse.

Apelin-13 protects the lungs from ischemia-reperfusion injury by attenuating inflammatory and oxidative stress

Apelin has been reported to regulate mitochondrial function in myocardial ischemia-reperfusion injury and cerebral ischemia-reperfusion injury. However, the role of apelin-13 in lung ischemia-reperfusion injury (LIRI) remains unclear. This study established an experimental rat model to evaluate the underlying mechanisms of apelin-13 on LIRI. Twenty-four rats were randomly divided to sham operation group (group SM), ischemia/reperfusion group (group IR), and apelin-13 treatment group (group APL). The effects of apelin-13 on LIRI were determined histologically using H&E staining, while the wet/dry weight ratio was used to assess lung edema caused by LIRI. Inflammatory cytokines were also detected in Bronchoalveolar lavage (BAL) fluid by ELISA. The protein expression of UCP2 and the morphological changes of mitochondria were determined by western blotting and electromicroscopy, respectively. The results demonstrated the structural damage of lung tissues and lung edema in group IR. An increased level of inflammatory cytokines including IL-1β, IL-6 and TNF-α was observed in rats with LIRI using ELISA. After that, oxidative stress and morphological damage of mitochondria were also shown in group IR. Yet, the application of apelin-13 reversed all these deleterious effects in group APL. The protective effects of apelin-13 were indicated by decreased reactive oxygen species (ROS) and elevated UCP2 expression levels in rats. In conclusion, this study revealed that apelin-13 had protective effects against LIRI via attenuating lung edema, the production of inflammatory cytokines, oxidative stress and mitochondrial dysfunction.

A novel missense mutation in SMPX causes a rare form of X-linked postlingual sensorineural hearing loss in a Chinese family

BACKGROUND

X-linked deafness-4 (DFNX4) caused by the functional loss of the SMPX gene is one form of nonsyndromic hearing loss with postlingual onset. This study aimed to investigate the cause of X-linked inherited sensorineural nonsyndromic hearing loss in a four-generation Chinese family and to explain the reason for extremely different hearing phenotypes between the proband and other family members.

METHODS

Whole-exome sequencing (WES) and co-segregation analysis were used to identify the pathogenic variants. Furthermore, methylation differences among the androgen receptor genes were utilized to investigate whether the severe phenotype of the proband is related to X-chromosome inactivation (Xi).

RESULTS

We described in detail the clinical characteristics of the family and identified a novel missense mutation (c.262C>G: p.Gln88Glu) in SMPX by WES. This variant was co-segregated with the postlingual hearing loss phenotype and was absent in 300 normal controls. Also, we found that the proband, a 4-year-old female, carries two new compound heterozygous mutations (c.9259G>A: p.Val3087Ile and c.8576G>A: p.Arg2859His) in the USH2A gene, but to date without any other symptoms except profound sensorineural hearing loss. Additionally, analysis of X-chromosome inactivation indicated moderate skewing in the proband, which is probably related to the heterogeneity of clinical characteristics.

CONCLUSIONS

This is the first study to report a missense mutation of SMPX in a Chinese family. Our findings have enriched the mutation and phenotypic spectrum of the SMPX gene.

Family History of Crohn’s Disease (CD) May Be a Risk Factor for Developing de novo CD following Ileal Pouch Anal Anastomosis (IPAA) for Ulcerative Colitis (UC)

Introduction/Objective

A subset of patients with an established diagnosis of UC develops signs of CD (de novo CD) following IPAA. While the etiology and risk factors of de novo CD remain largely unknown, preliminary studies have shown controversial results regarding family history of inflammatory bowel disease (IBD) and smoking history.

Methods

Patients that underwent IPAA for UC, with at least 1 year of follow-up, were identified (n=161; 1996 to 2018). We retrospectively reviewed the electronic medical records. Patients that were diagnosed with de novo CD during the follow-up period were further identified. Smoking history and family history of IBD were evaluated. Chi square test was performed to compare the frequencies. Odds ratio (OR) and 95% confidence intervals (CIs) were estimated by logistic regression model. P&lt;0.05 was considered statistically significant.

Results

29 de novo CD were identified. At the time of proctocolectomy, the family history of IBD and smoking history was documented in 152 UC patients including 27 that subsequently developed de novo CD. 23 of 152 had a family history of IBD (12 UC, 9 CD and 2 IBD, NOS). 19/129 (14.7%) UC patients without a family history of any type of IBD, 4/9 (44.4%) with a family history of CD, and 4/12 (33.3%) with a family history of UC developed de novo CD. Patients with a family history of CD were more likely to develop de novo CD post IPAA than those without a family history of any type of IBD (OR 4.63, 95% CI 1.14-18.82, p=0.03). Family history of UC did not correlate with development of de novo CD (OR 2.90; 95% CI 0.79-10.57, p=0.108). At the time of proctocoletomy, 11 were current smokers, 25 were former smokers, and 116 never smoked. In de novo CD group, there were 4/27 (14.8 %) former smokers and 23/27 (85.2 %) never smokers. No de novo CD patient was current smoker. In the UC group that remained as UC following IPAA, 11/125 (8.8%) were current smokers, 21/125 (16.8 %) former smokers, and 93/125 (74.4 %) were never smokers. Current smoking status was not associated with development of de novo CD (p = 0.214).

Conclusion

Family history of CD may be a risk factor for developing de novo CD following IPAA for UC. Current smoking status was not associated with development of de novo CD following IPAA for UC.

Impacts of extreme summers on European ecosystems: a comparative analysis of 2003, 2010 and 2018

In Europe, three widespread extreme summer drought and heat (DH) events have occurred in 2003, 2010 and 2018. These events were comparable in magnitude but varied in their geographical distribution and biomes affected. In this study, we perform a comparative analysis of the impact of the DH events on ecosystem CO₂ fluxes over Europe based on an ensemble of 11 dynamic global vegetation models (DGVMs), and the observation-based FLUXCOM product. We find that all DH events were associated with decreases in net ecosystem productivity (NEP), but the gross summer flux anomalies differ between DGVMs and FLUXCOM. At the annual scale, FLUXCOM and DGVMs indicate close to neutral or above-average land CO₂ uptake in DH2003 and DH2018, due to increased productivity in spring and reduced respiration in autumn and winter compensating for less photosynthetic uptake in summer. Most DGVMs estimate lower gross primary production (GPP) sensitivity to soil moisture during extreme summers than FLUXCOM. Finally, we show that the different impacts of the DH events at continental-scale GPP are in part related to differences in vegetation composition of the regions affected and to regional compensating or offsetting effects from climate anomalies beyond the DH centres. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.

MiRNA-485-5p, inhibits esophageal cancer cells proliferation and invasion by down-regulating O-linked N-acetylglucosamine transferase

OBJECTIVE

Previous reports suggest that miRNA-485-5p is dysregulated and contributes to tumorigenesis in some cancer types. Nevertheless, the biological role of miRNA-485-5p in esophageal cancer (EC) is not well understood. Additionally, we found that the expression of miR-485-5p in EC tissues was aberrant.

PATIENTS AND METHODS

Quantitative RT-PCR (qRT-PCR) was used to demonstrate the expression of miRNA-485-5p in EC cell lines. Cell counting kit-8 (CCK-8) assay and transwell assay indicated that miRNA-485-5p overexpression inhibited cell proliferation, migration, and invasion in EC cell lines. Additionally, Western blotting, dual-luciferase reporter assay, and rescue assay predicted that O-linked N-acetylglucosamine transferase (OGT) was a direct target of miRNA-485-5p. Moreover, we showed that miRNA-485-5p regulated EC tumorigenesis by down-regulating OGT expression in vitro and in vivo.

RESULTS

The upregulation of miR-485-5p (fold change = 44 and 26 in ECA109 and TE-1, respectively; p<0.001) was showed by qRT-PCR. Compared with the control groups, the expression miR-485-5p significantly suppressed the proliferation, migration, and invasion of EC cells. The bioinformatic analysis predicted that the 3' untranslated region (UTR) of OGT contains one miR-485-5p target sequences. Western blotting and dual-luciferase reporter assay showed that activation of OGT 3'UTR was increased by co-transfection with miR-485-5p. Finally, CCK-8 assay predicted that the rescue effects of OGT expression on miR-485-5p induced inhibition of cell growth and tumor weight in Eca109 and TE1 cells.

CONCLUSIONS

Our results suggest that miRNA-485-5p is a suppressor of EC tumorigenesis and could serve as a novel candidate for therapeutic applications in EC treatment.

Direct and seasonal legacy effects of the 2018 heat wave and drought on European ecosystem productivity

In summer 2018, central and northern Europe were stricken by extreme drought and heat (DH2018). The DH2018 differed from previous events in being preceded by extreme spring warming and brightening, but moderate rainfall deficits, yet registering the fastest transition between wet winter conditions and extreme summer drought. Using 11 vegetation models, we show that spring conditions promoted increased vegetation growth, which, in turn, contributed to fast soil moisture depletion, amplifying the summer drought. We find regional asymmetries in summer ecosystem carbon fluxes: increased (reduced) sink in the northern (southern) areas affected by drought. These asymmetries can be explained by distinct legacy effects of spring growth and of water-use efficiency dynamics mediated by vegetation composition, rather than by distinct ecosystem responses to summer heat/drought. The asymmetries in carbon and water exchanges during spring and summer 2018 suggest that future land-management strategies could influence patterns of summer heat waves and droughts under long-term warming.

Neuronal HIF-1α in the nucleus tractus solitarius contributes to ventilatory acclimatization to hypoxia

KEY POINTS

We hypothesized that hypoxia inducible factor 1α (HIF-1α) in CNS respiratory centres is necessary for ventilatory acclimatization to hypoxia (VAH); VAH is a time-dependent increase in baseline ventilation and the hypoxic ventilatory response (HVR) occurring over days to weeks of chronic sustained hypoxia (CH). Constitutive deletion of HIF-1α in CNS neurons in transgenic mice tended to blunt the increase in HVR that occurs in wild-type mice with CH. Conditional deletion of HIF-1α in glutamatergic neurons of the nucleus tractus solitarius during CH significantly decreased ventilation in acute hypoxia but not normoxia in CH mice. These effects are not explained by changes in metabolic rate, nor CO2 , and there were no changes in the HVR in normoxic mice. HIF-1α mediated changes in gene expression in CNS respiratory centres are necessary in addition to plasticity of arterial chemoreceptors for normal VAH.

ABSTRACT

Chronic hypoxia (CH) produces a time-dependent increase of resting ventilation and the hypoxic ventilatory response (HVR) that is called ventilatory acclimatization to hypoxia (VAH). VAH involves plasticity in arterial chemoreceptors and the CNS [e.g. nucleus tractus solitarius (NTS)], although the signals for this plasticity are not known. We hypothesized that hypoxia inducible factor 1α (HIF-1α), an O2 -sensitive transcription factor, is necessary in the NTS for normal VAH. We tested this in two mouse models using loxP-Cre gene deletion. First, HIF-1α was constitutively deleted in CNS neurons (CNS-HIF-1α-/- ) by breeding HIF-1α floxed mice with mice expressing Cre-recombinase driven by the calcium/calmodulin-dependent protein kinase IIα promoter. Second, HIF-1α was deleted in NTS neurons in adult mice (NTS-HIF-1α-/- ) by microinjecting adeno-associated virus that expressed Cre-recombinase in HIF-1α floxed mice. In normoxic control mice, HIF-1α deletion in the CNS or NTS did not affect ventilation, nor the acute HVR (10-15 min hypoxic exposure). In mice acclimatized to CH for 1 week, ventilation in hypoxia was blunted in CNS-HIF-1α-/- and significantly decreased in NTS-HIF-1α-/- compared to control mice (P < 0.0001). These changes were not explained by differences in metabolic rate or CO2 . Immunofluorescence showed that HIF-1α deletion in NTS-HIF-1α-/- was restricted to glutamatergic neurons. The results indicate that HIF-1α is a necessary signal for VAH and the previously described plasticity in glutamatergic neurotransmission in the NTS with CH. HIF-1α deletion had no effect on the increase in normoxic ventilation with acclimatization to CH, indicating this is a distinct mechanism from the increased HVR with VAH.

Protective effect of ethosuximide on hearing in NOD/LtJ mice via blockage of endogenous apoptosis

Purpose: To determine the protective effect of ethosuximide on the hearing of NOD/LtJ mice, and the underlying mechanism of action. Methods: The mice were randomly assigned to control and treatment groups (20 mice per group). Mice in the treatment group were administered ethosuximide intraperitoneally at a dose of 200mg/kg body weight (bwt), while those in the control group received an equivalent dose of saline via the same route. Both groups were subjected to auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE) tests, as well as determination of mRNA expressions of α1G, α1H, α1I, m-calpain, μ-calpain, and caspase-3. Results: At ages of 6 and 9 weeks, ABR values were significantly lower in the treatment group than those in the control group (p < 0.05). At age 3, 6 and 9 weeks, control group DPOAE values were much lower than those in the treatment group. However, at signal frequency of 35344 Hz, DPOAE value was significantly reduced in the treatment group (p < 0.05). There was significant down-regulation in mRNA expressions of α1G, α1H, α1I, m-calpain, μ-calpain and caspase-3, in the treatment group, when compared with the control group (p < 0.05). Conclusion: Ethosuximide delays mice hearing loss and protects their hearing via a mechanism involving blockage of endogenous apoptotic pathways. This mechanism may provide guidance in the search for suitable new drugs. Keywords: Ethosuximide, Endogenous apoptosis, Hearing, Protection

miR-488-3p sponged by circ-0000495 and mediated upregulation of TROP2 in head and neck squamous cell carcinoma development

TROP2 (trophoblast cell surface antigen 2) overexpression has been reported in many human cancers. The correlation between TROP2 and tumor aggressiveness has implied it could be a prognostic indicator. However, the roles of TROP2 and their underlying mechanisms remain of great interest in head and neck squamous cell carcinoma (HNSCC) biology. In the current study, the prognostic significance of TROP2 in HNSCC archival samples was determined using immunohistochemistry. Quantitative reverse transcriptase PCR (qRT-PCR) was used to measure the phenotypic effects of TROP2 knockdown, miR-488-3p re-expression, and circRNAs expression. Cell viability, migration/invasion as well as in vivo tumor formation assays were accessed. The interactions of miRNAs-TROP2 or circRNAs-miRNAs were determined by qRT-PCR, western blot analysis and luciferase assays. TROP2 was demonstrated overexpression in HNSCC patients and cancer cell lines. High expression of TROP2 was significantly associated with patient relapse. TROP2 promoted tumor cell proliferation, migration, invasion, and tumor growth, through AKT and MAPK pathways. Further investigation revealed that TROP2 is a direct target of miR-488-3p, while circ-0000495 bounds to miR-488-3p. Our study unraveled a novel mechanism by which down-regulation of miR-488-3p sponged by circ-0000495 releases its epigenetic silencing to TROP2. The increased TROP2 promotes tumor proliferation, therefore, providing evidence in support of targeting the circ-0000495/miR-488-3p/TROP2 axis in contributing to HNSCC therapy and preventing tumor metastasis.

Leucine promotes the growth of squabs by increasing crop milk protein synthesis through the TOR signaling pathway in the domestic pigeon (Columba livia)

Leucine (Leu) plays a critical regulatory role in protein synthesis, however, the effects and molecular mechanisms of Leu on crop milk protein in the domestic pigeons (Columba livia) are still unknown. Therefore, the study aimed to investigate the effects of dietary Leu supplementation on crop milk protein synthesis and the growth performance of squabs and the possible underlying mechanism. A total of 240 pairs of breeding pigeons (1102.3 ± 9.5 g/pair) were randomly assigned to 1 of 5 treatments, including a positive control (PC) diet that had adequate crude protein (crude protein, CP = 18%; Leu = 1.30%), a negative control (NC) diet that was low in CP (CP = 16%, Leu = 1.30%), and NC diets supplemented with Leu at 0.15%, 0.45%, or 1.05%. Compared with the NC diet, 0.15 to 0.45% Leu supplementation decreased BW loss and increased relative crop weight, crop thickness, and protein levels in the crop tissue and milk of breeding pigeons. However, dietary supplementation with 1.05% Leu inhibited ADFI in breeding pigeons. Dietary supplementation with 0.15 to 0.45% Leu decreased the mortality rate and increased the BW, eviscerated yield, and breast muscle yield of young squabs. The protein expression levels of the target of rapamycin (TOR), ribosomal protein S6 kinase 1 (S6K1), ribosomal protein S6 kinase (S6), eukaryotic initiation factor 4E binding protein 1 (4EBP1), and eukaryotic translation initiation factor 4E (eIF4E) were upregulated in the crop tissue of breeding pigeons in PC, 0.15% and 0.45% Leu-supplemented groups. Collectively, these results indicated that 0.15 to 0.45% Leu supplementation could decrease BW loss, increase milk protein synthesis in the crop of breeding pigeons, and enhance the survival rate and growth performance of young squabs through the TOR signaling pathway.

Targeted disruption of TORC1 retards young squab growth by inhibiting the synthesis of crop milk protein in breeding pigeon (Columba livia)

This study was conducted to explore the regulatory role of the target of rapamycin complex 1 (TORC1) signaling pathway in crop milk synthesis in breeding pigeons (Columba livia). Three groups of breeding pigeons in the lactation period (n = 30 pairs/group) were respectively injected with rapamycin (RAPA, a specific inhibitor of the target of rapamycin complex) at doses of 0 (vehicle, control), 0.6, or 1.2 mg/kg body weight (BW)/day via the wing vein for 7 days. The average daily feed intake (ADFI) and BW of the breeding pigeons and the BW of young squabs were respectively recorded throughout the experimental period. The breeding pigeons were sacrificed to collect their crop tissues, crop milk, and serum on the eighth day of the experiment. The results showed that neither 0.6 nor 1.2 mg/kg BW RAPA injection affected BW loss or ADFI in breeding pigeons (P > 0.05), while crop thickness and crop relative weight were significantly decreased (P < 0.05) in the 1.2 mg/kg BW rapamycin-injected group. Simultaneously, RAPA (especially at 1.2 mg/kg BW) decreased the crude protein, αs1-casein, αs2-casein, β-casein, and amino acid contents (Asp, Thr, Ser, Glu, Gly, Ala, Cys, Val, Met, Ile, Leu, Tyr, Lys, His, Arg, and Pro) of crop milk (P < 0.05) and the concentrations of albumin, total protein, and uric acid in the serum of breeding pigeons (P < 0.05). Additionally, the expression of TORC1 pathway-related proteins (TORC1, S6K1, S6, 4EBP1, and eIF4E) was downregulated in the crop tissues of breeding pigeons by 0.6 or 1.2 mg/kg BW/day RAPA injection (P < 0.05). Accordingly, the average daily gain (ADG) of young squabs declined, and the mortality rate increased significantly (P < 0.05). Together, the results showed that RAPA reduced protein and amino acid levels in the crop milk of breeding pigeons and retarded young squab growth, suggesting a crucial role of TORC1 in crop milk synthesis in breeding pigeons.

Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys

Sub-picosecond magnetisation manipulation via femtosecond optical pumping has attracted wide attention ever since its original discovery in 1996. However, the spatial evolution of the magnetisation is not yet well understood, in part due to the difficulty in experimentally probing such rapid dynamics. Here, we find evidence of a universal rapid magnetic order recovery in ferrimagnets with perpendicular magnetic anisotropy via nonlinear magnon processes. We identify magnon localisation and coalescence processes, whereby localised magnetic textures nucleate and subsequently interact and grow in accordance with a power law formalism. A hydrodynamic representation of the numerical simulations indicates that the appearance of noncollinear magnetisation via optical pumping establishes exchange-mediated spin currents with an equivalent 100% spin polarised charge current density of 107 A cm-2. Such large spin currents precipitate rapid recovery of magnetic order after optical pumping. The magnon processes discussed here provide new insights for the stabilization of desired meta-stable states.

Abstract P5-07-15: Adipose-derived peptides from breast cancer patients promote the malignancy of breast cancer MCF-7 cells

Adipose stromal/stem cells (ADSCs) could regulate malignancy behaviors of breast cancer, which was due to adipose-derived cytokines in part, such as leptin and resistin. Recently, peptides have been demonstrated to be potential targets for cancer therapy. It's valuable to analyze the characters of adipose-secreted peptides systematically. In this study, we isolated primary adipocytes from adipose tissue adjacent to breast tumor and breast benign lesions respectively, and then co-cultured breast cancer cells MCF-7 with tumor adjacent adipocytes (TAAs)/breast benign adipocytes (BBAs) separately. Compared to BBAs, TAAs could promote proliferation and migration ability of MCF-7. Then we extracted and purified peptides from supernatant of TAAs and BBAs using ultrafiltration, and the effects of TAAs-derived peptides compound on breast cancer cells appeared accordance with the adipose cells. 100 peptides, which were derived from 90 protein precursors, were found to be differentially secreted between TAAs and BBAs by LC-MS/MS (p &lt; 0.05). Gene Ontology (GO) and Pathway analyses appeared that these altered peptides were mainly contributed to cell adhesion, and regulation of Ras-protein signal transduction. These results showed that these differentially secreted peptides could regulate breast cancer cell malignancy, which indicated that they could be potential therapeutic targets and diagnostic bio-marker for breast cancer.

Citation Format: Fu Z, Li W, Wu H, Huang X, Li J, Sun C, Tang J, Yin Y. Adipose-derived peptides from breast cancer patients promote the malignancy of breast cancer MCF-7 cells [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-07-15.

Abstract P3-10-29: tRNA-derived fragments as novel predictive biomarkers for trastuzumab-resistant breast cancer

Background: Resistance to trastuzumab remains a common challenge to HER-2 positive breast cancer. Up until now, the underlying mechanism of trastuzumab resistance is still unclear. tRNA-derived small non-coding RNAs, a new class of small non-coding RNA (sncRNAs), have been observed to play an important role in cancer progression. However, the relationship between tRNA-derived fragments and trastuzumab resistance is still unknown.

Methods:We detected the levels of tRNA-derived fragments expression in normal breast epithelial cell lines, trastuzumab-sensitive and -resistant breast cancer cell linesusing high-throughput sequencing.qRT-PCR was conducted to validate the differentially expressed fragments in serums from trastuzumab-sensitive and -resistant patients. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the power of specific tRNA-derived fragments.Progression-free survival (PFS) was analyzed using Cox-regression.

Results:Our sequence results showed that tRNA-derived fragments were differentially expressed in the HBL-100, SKBR3, and JIMT-1 cell lines. tRF-30-JZOYJE22RR33 and tRF-27-ZDXPHO53KSN were found significantly upregulated in trastuzumab-resistant patients compared to sensitive individuals, and the ROC analysis showed that tRF-30-JZOYJE22RR33 and tRF-27-ZDXPHO53KSN were correlated with trastuzumab resistance. In a multivariate analysis, higher levels of tRF-30-JZOYJE22RR33 and tRF-27-ZDXPHO53KSN expression were associated with significantly shorter PFS in patients with metastatic HER-2 positive breast cancer.

Conclusion: Our results suggest that tRF-30-JZOYJE22RR33 and tRF-27-ZDXPHO53KSN play important roles in trastuzumab resistance. Patients with high levels of tRF-30-JZOYJE22RR33 and tRF-27-ZDXPHO53KSN expression benefitted less from trastuzumab-based therapy than those that express lower-levels of these molecules. tRF-30-JZOYJE22RR33 and tRF-27-ZDXPHO53KSN may be potential biomarkers and intervention targets in the clinical treatment of trastuzumab-resistant breast cancer.

Citation Format: Sun C, Li W, Wu H, Huang X, Li J, Fu Z, Tang J, Yin Y. tRNA-derived fragments as novel predictive biomarkers for trastuzumab-resistant breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-10-29.

[Multicenter study of human adenovirus infection in pediatric community-acquired pneumonia in China]

Objective: To investigate the predominant genotypes and epidemiological characteristics of human adenovirus (HAdV) in pediatric community-acquired pneumonia (CAP) in China. Methods: This was a repeated cross sectional study. Between November 2014 and November 2016, nasopharyngeal aspirates (NPAs) or throat swabs from each hospitalized pediatric patients diagnosed as CAP in 12 hospitals in Northern and Southern China were collected. Respiratory specimens were screened for 18 respiratory viruses including HAdV by using Luminex xTAG RVP Fast V2 multiplex Assay. Typing of HAdV and analysis for the epidemiological characteristic of HAdV were performed. Results: (1) A total of 2 723 hospitalized pediatric patients with CAP were enrolled in this study and 156 (5.7%, 156/2 723) respiratory specimens were positive for HAdV, and 74 (6.6%, 74/1 128) and 82 (5.1%, 82/1 595) were in Northern and Southern China, respectively. There was no significant difference in the positive detection rate between the Northern and Southern China. (2) In Northern China, the HAdV positive rate of children at the age of <6 months, 6 months-<1 years, 1-<3 years, 3-<5 years and ≥5 years was 5.9%(6/101), 6.7%(7/104), 10.3%(34/331), 4.1%(11/266) and 4.9%(16/326), respectively, and the incidence of HAdV infection peaked in children aged 1-3 years (χ(2)=11.511, P=0.021). While in Southern China the HAdV positive rate of children at the age of <6 months, 6 months-<1 years, 1-<3 years, 3-<5 years and ≥5 years was 2.2% (7/312), 4.6% (12/259), 6.3% (31/494), 7.3% (18/245) and 4.9%(14/285), respectively. There was no significant difference in the positive detection rate among age groups. (3) In 2015, the highest detection rate of HAdV in northern China was 12.5% (25/200) in winter, and in Southern China was 6.7% (35/525) in spring and 5.3% (19/357) in summer. (4) In 108 cases of HAdV positive specimens typing was done and 80 in cases classification was successfully performed.Totally 7 genotypes of HAdV, including HAdV-3 (n=32), HAdV-7 (n=9), HAdV-1 (n=12), HAdV-2 (n=15), HAdV-5 (n=10), HAdV-6 (n=1) and HAdV-4 (n=1), were detected. The predominant HAdV genotypes were HAdV-3 (30.8%, 8/26) and HAdV-7 (26.9%, 7/26) in Northern China, while HAdV-3 (44.4%, 24/54) and HAdV-2 (22.2%, 12/54) were the most prevalent genotypes in Southern China. Conclusions: HAdV is an important viral pathogen in pediatric CAP. The predominant HAdV genotypes and peak seasons of HAdV infections were different between Northern and Southern China. The predominant HAdV genotypes were HAdV-3 and HAdV-7 in Northern China, while HAdV-3 and HAdV-2 in Southern China. The peak season of HAdV infections was winter in Northern China. However, HAdV infections are more common in spring and summer in Southern China.

Radiotherapy improves the survival of patients with metastatic esophageal squamous cell carcinoma: a propensity score matched analysis of Surveillance, Epidemiology, and End Results database

The survival advantage of radiotherapy (RT) for patients with metastatic esophagus cancer has not been adequately evaluated. This study aims to find out the role of RT for metastatic esophagus cancer and to find the different effect for RT to esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC). This study included 5,970 metastatic esophagus cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database, registered from January 2004 to December 2013. Propensity score (PS) analysis with 1:1 nearest neighbor matching method was used to ensure well-balanced characteristics of all comparison groups by histological types. The Kaplan-Meier and Cox proportional hazardous models were used to evaluate the overall survival (OS), cancer-specific survival (CSS), and corresponding 95% confidence interval (CI). Generally speaking, EAC did not get survival benefit from RT (median OS for RT group vs. no-RT group-8.0, 7.6-8.4 vs. 9.0, 8.5-9.5, P = 0.073), whereas RT for metastatic ESCC did significantly improve OS (median OS for RT group vs. no-RT group-8.0, 7.4-8.6 vs. 7.0, 6.4-7.6, P = 0.044). Therefore, compared with adenocarcinoma, ESCC could get more survival benefit from RT.