[Diagnostic value of computed tomographic perfusion imaging of whole liver for quantitative assessment of blood flow state in liver cancer after transcatheter arterial chemoembolization]

Objective: To investigate the diagnostic value of whole liver CT perfusion imaging in the quantitative evaluation of hemodynamic changes before and after transcatheter arterial chemoembolization (TACE). Methods: Twenty-six patients with hepatocellular carcinoma underwent TACE therapies were recruited. Whole -liver computed tomographic perfusion imaging (CTPI) was performed 2~3 days before TACE and 1 month after TACE. We measured the following perfusion parameters: hepatic arterial perfusion (HAP), portal venous perfusion (PVP), total liver perfusion (TLP), hepatic arterial perfusion index (HAPI), and time-to-peak (TTP).The F-test, t-test and Rank sum test were used for statistical analysis. Results: A total of 34 HCC lesions were detected. According to the deposition of lipiodol after TACE, they were divided into a lipiodol dense group (21) and a lipiodol light group (13). The length of hepatocellular carcinoma lesions after TACE showed a decreasing trend compared with preoperative TACE. The lesions in the lipiodol dense group had smaller lesions than those in the lipiodol light group. The preoperative and postoperative longitudinal diameters were (3.12 ± 0.58) cm vs. (1.93 ± 0.79) cm, (2.98 ± 2.01) cm vs. (2.58 ± 2.00) cm, the differences were statistically significant (t = 15.1, 8.65, P < 0.05). The preoperative HAP and HPI of the lipiodol dense group were the highest, and the peritumoral within 1cm was higher than that of the surrounding liver parenchyma. The PVP, TLP, and TTP were highest in the surrounding of liver parenchyma, and 1 cm higher than the tumor area in the background. The corresponding perfusion parameters were statistically significant (P < 0.05); HAP and HPI were 1 cm higher than the surrounding liver parenchyma. After the operation, PVP, TLP and TTP were lower than the background liver parenchyma, the difference was statistically significant (P < 0.05); HAP and HPI decreased by 1 cm after the operation, and the PVP, TLP, and TTP increased. There was no significant difference after operation in the blood perfusion of background liver parenchyma (P ˃ 0.05). The HAP and HPI decreased, and the PVP and TTP increased in the lipiodol light group after operation (P < 0.05). There was no significant difference between the other two regions (P ˃ 0.05). Conclusion: There was no blood perfusion in the lipiodol deposition area after TACE. The perfusion volume of hepatic artery in the peritumoral 1 cm and lipiodol light group decreased and the portal venous perfusion increased. CTPI can quantitatively evaluate blood perfusion state, which is of great significance for the determination of treatment plans before TACE treatment to assume the postoperative therapeutic effect in liver cancer.

[Association between pregnancy-related anxiety of pregnant women and autism-like behavior in their offspring at 18 months of age]

Objective: To investigate the relationship of pregnancy-related anxiety of pregnant women in second/third trimesters and autism-like behaviors in their offspring at 18 months of age. Methods: Based on a prospective cohort study design, we evaluated the situation of pregnancy-related anxiety of women during second and third trimesters through a Pregnancy-Related Anxiety Questionnaire. Subjects under study were classified into three groups, 1) those with pregnancy- related anxiety during both trimesters, 2) those with pregnancy-related anxiety at one trimester and 3) those without pregnancy-related anxiety in either trimester. When their children were 18 months, autism-like behaviors (ALB) were evaluated, using the part A of Checklist for Autism in Toddlers-23, and then classified into three groups as non-ALB group, minor ALB group and major ALB group. Multi-nominal logistic Regression was used to analyze the relationship of pregnancy-related anxiety with autism-like behaviors. Results: Compared with non-ALB group, children whose mother with pregnancy-related anxiety during both trimesters presented significant higher risk on ALB than children whose mother without pregnancy-related anxiety in these two periods (relative risk, RR=2.43, 95% CI: 1.21-4.86, P=0.012), major factors as pregnant women's IQ and gestational diabetes mellitus, premature delivery and education levels of fosterers on these pregnant women were under control. Our results from the stratified analysis showed: when in the subgroup that mother was the main fosterer of the child, there was an significant increase of risk in children whose mothers with pregnancy-related anxiety during both trimesters (RR=4.22, 95%CI: 1.73-10.32, P=0.002). Conclusion: The association between pregnancy-related anxiety and autism-like behavior was not strong but influenced by the fosterer of the child.

Genetic variant spectrum in 265 Chinese patients with hemophagocytic lymphohistiocytosis: Molecular analyses of PRF1, UNC13D, STX11, STXBP2, SH2D1A, and XIAP

Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening hyperinflammatory disease. This study aimed to investigate the frequencies and distributions of inherited variants in PRF1, UNC13D, STX11, STXBP2, SH2D1A, and XIAP genes in Chinese patients with HLH. A total of 265 patients diagnosed with HLH from January, 2010 to December, 2016 were recruited and analyzed for the 6 genes. Genetic variants were observed in 87 (32.83%) patients. 36 (13.58%) exhibited variants in UNC13D, 18 (6.79%) exhibited PRF1 variants, 10 (3.77%) had variants in XIAP, 9 (3.40%) exhibited variants in STXBP2, 6 (2.26%) carried variants in SH2D1A, 1 (0.38%) had STX11 variant, and 7 (2.64%) exhibited digenic variants. Monoallelic variants were the most common, which accounted for 49.43% of all cases with variants. All variants were confirmed to be germline-derived. The present study describes a distinct variant spectrum in Chinese patients with HLH, whereby UNC13D is the most frequently mutated gene with missense variants that are the most common molecular defects. The variant profile of Chinese HLH patients is quite different from that of Western cohorts but similar to that of Korean patients, yet showing its own uniqueness. This racial difference shows the role of genetic background in the occurrence of HLH.

Acute effect of multiple ozone metrics on mortality by season in 34 Chinese counties in 2013-2015

BACKGROUND

Although numerous multicentre studies have estimated the association between ozone exposure and mortality, there are currently no nationally representative multicentre studies of the ozone-mortality relationship in China.

OBJECTIVE

To investigate the effect on total (nonaccidental) and cause-specific mortality of short-term exposure to ambient ozone, and examine different exposure metrics.

METHODS

The effects of short-term exposure to ozone were analysed using various metrics (daily 1-h maximum, daily 8-h maximum and daily average) on total (nonaccidental) and cause-specific (circulatory and respiratory) mortality from 2013 to 2015 in 34 counties in 10 cities across China. We used distributed lag nonlinear models for estimating county-specific relative risk of mortality and combined the county-specific relative rates by conducting a random-effects meta-analysis.

RESULTS

In all-year analyses, a 10 μg m^-3 increase in daily average, daily 1-h maximum and daily 8-h maximum ozone at lag02 corresponded to an increase of 0.6% (95% CI: 0.33, 0.88), 0.26% (95% CI: 0.12, 0.39) and 0.37% (95% CI: 0.2, 0.55) in total (nonaccidental) mortality, 0.66% (95% CI: 0.28, 1.04), 0.31% (95% CI: 0.11, 0.51) and 0.39% (95% CI: 0.16, 0.62) in circulatory mortality, and 0.57% (95% CI: -0.09, 1.23), 0.11% (95% CI: -0.22, 0.44) and 0.22% (95% CI: -0.28, 0.72) in respiratory mortality, respectively. These estimates had a different seasonal pattern by cause of death. In general, the seasonal patterns were consistent with the times of year when ozone concentrations are highest.

CONCLUSIONS

Our findings suggest that in China, the acute effects of ozone are more closely related to daily average exposure than any other metric.

[Topoisomerase inhibitor upregulates MICA/B expression in breast cancer cells through ATM/ATR and NF-κB pathway]

OBJECTIVE

To investigate the effects of chemotherapeutic agents widely used in clinical practice on major histocompatibility complex class I-related chain A and B (MICA/B) expression in breast cancer cells, and to explore the molecular mechanisms involved.

METHODS

We examined MICA/B mRNA and surface protein expressions in breast cancer cells treated with chemotherapeutic agents by real-time RT-PCR and flow cytometry respectively. The blocking effects of ataxia telangiectasia mutated and Rad3-related kinase (ATM/ATR) inhibitor caffeine and nuclear factor κB (NF-κB) inhibitor pynolidine dithiocarbamate (PDTC) on etoposide-upregulated MICA/B mRNA and surface protein expressions were investigated. Electrophoretic mobility shift assay (EMSA) was taken to investigate whether etoposide enhanced the binding of NF-κB to MICA/B gene promoter.

RESULTS

Three topoisomerase inhibitors etoposide, camptothecin and doxorubicine upregulated MICA and MICB mRNA expressions in breast cancer cell MCF-7. Comparing to no-drug-treated cells, MICA mRNA levels increased to (1.68±0.17), (2.54±0.25) and (3.42±0.15) fold, and levels of MICB mRNA increased to (1.82±0.24), (1.56±0.05) and (5.84±0.57) fold respectively in cancer cells treated by etoposide at the concentrations of 5, 20 and 100 μmol/L (P<0.05). MICA and MICB mRNA levels also increased significantly when MCF-7 cells were incubated with camptothecin or doxorubicine at the specific concentrations (P<0.05). MICB mRNA expression also increased slightly in another breast cancer cell SK-BR-3 treated by topoisomerase II inhibitors etoposide and camptothecin (P<0.05). Furthermore, etoposide and camptothecin upregulated MICA/B surface protein expression in MCF-7 cells (P<0.05), and the upregulation was found in both living and apoptotic cells. Our study showed that etoposide induced-MICA/B expression in MCF-7 was inhibited by caffeine at different concentrations. When cancer cells were treated by caffeine with 1, 5 and 10 mmol/L, MICA mRNA levels decreased from (3.75±0.25) to (0.89±0.05), (0.81±0.02) and (0.48±0.04) fold respectively (P<0.001), and MICB mRNA levels decreased from (6.85±0.35) to (1.36±0.13), (0.76±0.06) and (0.56±0.03) fold (P<0.05), while MICA/B protein levels decreased from (3.42±0.05) to (1.32±0.03), (1.21±0.06) and (1.14±0.03) fold (P<0.001), indicating that etoposide-induced MICA/B expression was inhibited by ATM/ATR inhibitor. Similarly, NF-κB inhibitor PDTC also inhibited MICA/B mRNA and protein expressions induced by etoposide significantly when MCF-7 cells were incubated with PDTC at the concentrations of 10, 50 and 100 μmol/L (P<0.05), indicating that NF-κB was also involved in this process. EMSA showed that the binding of NF-κB to MICA/B promoter enhanced in MCF-7 cells after etoposide treatment.

CONCLUSION

Topoisomerase inhibitor increased MICA/B mRNA and protein expressions in breast cancer cells, indicating that chemotherapeutic agents might increase the recognizing and killing ability of immunocytes to breast cancer cells. ATM/ATR and NF-κB pathways might be involved in it.

Systematic review and meta-analysis of the genetic association between protamine polymorphism and male infertility

While several previous studies have proposed an association between male infertility and protamine polymorphism, the reported findings have shown some inconsistency. To evaluate the potential association between the two most common single nucleotide polymorphisms (rs2301365 and rs1646022) in protamine and male infertility, we performed a meta-analysis involving 2713 cases and 2086 controls from 15 published case-controlled studies. Overall, our analysis showed significant associations between the specific protamine single-nucleotide polymorphism (rs2301365) and male infertility, and this association was indicated by all of the models we tested. Subgroup analysis revealed significant associations with a Caucasian background, PCR sequence, population-based, case size of > 150 and case size of < 150 subgroups. Similarly, significant associations were found between rs1646022 and male infertility in the hospital population and case size of < 200 subgroups. However, trial sequential analysis showed that the number of patients in the study did not reach optimal information size. Further studies with larger sample sizes are now warranted to clarify the potential roles of the two protamine polymorphisms in the pathogenesis of male infertility. This may help us to understand the precise molecular mechanisms underlying the effect of protamines upon male infertility.

Abstract P1-10-08: Development of a first-in-class oral selective ERα covalent antagonist (SERCA) for the treatment of ERαWT and ERαMUT breast cancer

Mutations in estrogen receptor alpha (ERα) are detected in up to 30% of breast cancer patients who have relapsed during endocrine therapy. ERα mutations functionally confer resistance to existing classes of endocrine therapies, likely through gaining constitutive activity. The fact that current ER-directed therapies are only partially effective in the ERα mutant setting, and that a significant proportion of resistant breast cancer metastases continue to remain dependent on ERα signaling for growth/survival, highlights the critical need to develop the next generation of ERα antagonists that can overcome aberrant ERα activity. Using structure-based drug design approaches we have identified a novel class of ERα antagonist referred to as Selective ERα Covalent Antagonist (SERCA) that inactivate both wild-type and mutant ERα by targeting a unique cysteine residue that is not conserved among other steroid hormone receptors. Biophysical, biochemical and cellular analyses confirm the covalent mechanism of action, specific binding to ER and selective inhibition of ERα-dependent transcription of SERCAs. H3B-6545 is a highly selective SERCA that potently antagonizes wild-type and mutant ERα in biochemical and cell based assays demonstrating increased potency over standard of care and other experimental agents. In vivo, H3B-6545 shows superior efficacy to fulvestrant in the MCF-7 xenograft model with once daily oral dosing, achieving maximal antitumor activity at doses &gt;10x below the maximum tolerated dose in mice. In addition, H3B-6545 shows superior antitumor activity to both tamoxifen and fulvestrant in patient derived xenograft models of breast cancer carrying estrogen receptor mutations. In summary, H3B-6545 is a first-in-class, orally available and selective ER covalent antagonist with a compelling pre-clinical profile that is being developed for the treatment of ERα positive breast cancer.

Citation Format: Korpal M, Puyang X, Furman C, Zheng GZ, Banka D, Wu J, Zhang Z, Thomas M, Mackenzie C, Yao H, Rimkunas V, Kumar P, Caleb B, Karr C, Subramanian V, Irwin S, Larsen N, Vaillancourt F, Nguyen T-V, Davis A, Chan B, Hao MH, O'Shea M, Prajapati S, Agoulnik S, Kuznetsov G, Kumar N, Yu Y, Lai G, Hart A, Eckley S, Fekkes P, Bowser T, Joshi JJ, Selvaraj A, Wardell S, Norris J, Smith S, Reynolds D, Mitchell L, Wang J, Yu L, Kim A, Rioux N, Sahmoud T, Warmuth M, Smith PG, Zhu P. Development of a first-in-class oral selective ERα covalent antagonist (SERCA) for the treatment of ERαWT and ERαMUT breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-10-08.

The impact of isolated maternal hypothyroxinaemia on the incidence of large-for-gestational-age infants: the Ma'anshan Birth Cohort study

OBJECTIVE

The purpose of this study was to investigate whether isolated maternal hypothyroxinaemia (IMH) is associated with risks of small/large-for-gestational-age (SGA/LGA) infants.

DESIGN

Population-based prospective cohort study.

SETTING

Ma'anshan Maternal and Child Health (MCH) clinics, China.

POPULATION

Pregnant women with singleton births (n = 3178).

METHODS

Descriptive statistics were calculated for the demographic characteristics of the mothers and their newborns. Linear regression was applied to estimate the association between thyroid hormone levels and birthweight. Logistic regression was performed to calculate the association between IMH and SGA/LGA.

MAIN OUTCOME MEASURES

Outcomes included SGA/LGA.

RESULTS

The prevalence of IMH, defined as a free thyroxine value (FT4) lower than the 2.5th percentile with normal thyroid stimulating hormone, was 2.5% (78/3080) and 2.5% (74/2999) in the first and second trimesters, respectively. Additionally, 306 (9.6%) and 524 (16.5%) infants were defined as SGA and LGA, respectively. No evidence supported the notion that IMH is associated with an increased risk for SGA in either the first [odds ratio (OR): 1.762, 95% confidence interval (CI): 0.759-4.089] or the second (OR: 0.763, 95% CI: 0.231-2.516) trimester. However, an increased risk of LGA was observed among IMH women in the second trimester (OR: 2.088, 95% CI: 1.193-3.654). Maternal TPO-Ab positivity in the second trimester increased the risk of SGA (OR: 2.094, 95% CI: 1.333-3.290).

CONCLUSION

This study provides evidence that IMH is associated with LGA.

FUNDING

This work was supported by the National Natural Science Foundation of China (No. 81330068).

TWEETABLE ABSTRACT

Isolated maternal hypothyroxinaemia may increase the risk of large-for-gestational-age infants.

[Association between elective cesarean section and infants' developmental behaviors: a cohort study]

Objective: To investigate the effect of elective cesarean section (ECS) on infants' developmental behaviors. Methods: A total of 3 474 pregnant women living in Ma'anshan more than 6 months and accepting obstetric examination in Ma'anshan Maternal and Child Care Center were recruited from May 2013 to September 2014. Excluding participants with pregnancy termination (162), twin pregnancy (39), assisted delivery (14), emergency cesarean section (76) and unclear delivery mode (141), 3 042 pair of mother and infant entered the final analysis. Information of maternal basic demographic characteristics, pregnancy histories, pregnancy life style and pregnancy-related diseases were collected by using self-complied Maternal and Child Health Questionnaire. Information of infants' general condition and delivery modes were acquired from obstetric record. The Ages and Stages Questionnaires-third edition was used to assess infants' communication, gross motor, fine motor, problem solving and person-social function, which was completed at age of 6 months old and 18 months old, respectively. And multi-factor non-conditional logistic regression model was used to analyze the association between ECS and infants' developmental behaviors. Results: The prevalence of ECS was 47.5% (1 443/3 042), among which ECS without medical indication and ECS with medical indication were 27.2% (826/3 042) and 20.3% (617/3 042), respectively. After maternal demographic characteristics, pregnant exposure and infants' basic information adjusted, compared to women with vaginal delivery, both ECS with medical indication and without medical indication increased the risk of a delay in gross motor on infants at 6 months old (RR (95%CI: 1.72 (1.08-2.77) and 1.87 (1.11-3.15), respectively.) ECS without indication decreased the risk of a delay in fine motor on infants at 6 months old (RR (95%CI):0.48 (0.28-0.82)), both ECS without medical indication and with medical indication had no statistically significant effect on 18 months infants' communication, gross motor, fine motor, problem solving and person-social function, the RR (95%CI) for ECS without medical indication were 0.86 (0.43-1.74), 1.55 (0.86-2.78), 0.74 (0.49-1.15), 1.10 (0.68-1.78) and 1.17 (0.66-2.08), respectively; and the RR (95%CI) for ECS with medical indication were 0.33 (0.12-1.02), 1.10 (0.55-2.21), 0.79 (0.48-1.29), 0.58 (0.29-1.13) and 1.48 (0.78-2.81), respectively. Conclusion: ECS affected motor development in infants at the age of 6 months old, and no influence was found in infants at the age of 18 months old.

A glimpse of gluons through deeply virtual compton scattering on the proton

The internal structure of nucleons (protons and neutrons) remains one of the greatest outstanding problems in modern nuclear physics. By scattering high-energy electrons off a proton we are able to resolve its fundamental constituents and probe their momenta and positions. Here we investigate the dynamics of quarks and gluons inside nucleons using deeply virtual Compton scattering (DVCS)-a highly virtual photon scatters off the proton, which subsequently radiates a photon. DVCS interferes with the Bethe-Heitler (BH) process, where the photon is emitted by the electron rather than the proton. We report herein the full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the regime where the scattering is expected to occur off a single quark, measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.

DNA methylation and expression of imprinted genes are associated with the viability of different sexual cloned buffaloes

The DNA methylation of imprinted genes is an important way to regulate epigenetic reprogramming of donor cells in somatic cell nuclear transfer (SCNT). However, the effects of sexual distinction on the DNA methylation of imprinted genes in cloned animals have seldom been reported. In this study, we analysed the DNA methylation status of three imprinted genes (Xist, IGF2 and H19) from liveborn cloned buffaloes (L group, three female and three male), stillborn cloned buffaloes (S group, three female and three male) and natural reproduction buffaloes (N group, three female and three male), using bisulphite sequencing polymerase chain reaction (BS-PCR). The expression levels of these imprinted genes were also investigated by quantitative real-time PCR (QRT-PCR). The DNA methylation levels of H19 were not significantly different among the groups. However, the Xist in female and IGF2 in male of the S group were found to be significantly hypomethylated in comparison with the same sexual buffaloes in L group and N group (p < .05). Furthermore, the expression levels of Xist, IGF2 and H19 in the stillborn female cloned buffaloes of S group were significantly higher than that of the female buffaloes in the L group and N group (p < .05). The expression levels of IGF2 and H19 in the stillborn male cloned buffaloes in the S group were significantly higher than that of the male buffaloes in the L group and N group (p < .05). These results indicate that Xist may be associated with the viability of female cloned buffaloes, and IGF2 may also be related to the viability of male cloned buffaloes.

Elevation of adenylate energy charge by angiopoietin-like 4 enhances epithelial-mesenchymal transition by inducing 14-3-3γ expression

Metastatic cancer cells acquire energy-intensive processes including increased invasiveness and chemoresistance. However, how the energy demand is met and the molecular drivers that coordinate an increase in cellular metabolic activity to drive epithelial–mesenchymal transition (EMT), the first step of metastasis, remain unclear. Using different in vitro and in vivo EMT models with clinical patient’s samples, we showed that EMT is an energy-demanding process fueled by glucose metabolism-derived adenosine triphosphate (ATP). We identified angiopoietin-like 4 (ANGPTL4) as a key player that coordinates an increase in cellular energy flux crucial for EMT via an ANGPTL4/14-3-3γ signaling axis. This augmented cellular metabolic activity enhanced metastasis. ANGPTL4 knockdown suppresses an adenylate energy charge elevation, delaying EMT. Using an in vivo dual-inducible EMT model, we found that ANGPTL4 deficiency reduces cancer metastasis to the lung and liver. Unbiased kinase inhibitor screens and Ingenuity Pathway Analysis revealed that ANGPTL4 regulates the expression of 14-3-3γ adaptor protein via the phosphatidylinositol-3-kinase/AKT and mitogen-activated protein kinase signaling pathways that culminate to activation of transcription factors, CREB, cFOS and STAT3. Using a different mode of action, as compared with protein kinases, the ANGPTL4/14-3-3γ signaling axis consolidated cellular bioenergetics and stabilized critical EMT proteins to coordinate energy demand and enhanced EMT competency and metastasis, through interaction with specific phosphorylation signals on target proteins.

[The multicenter study on the registration and follow-up of low anticoagulation therapy for the heart valve operation in China]

OBJECTIVE

To investigate the optimal anticoagulation methods and monitoring strategy for Chinese patients undergoing heart valve replacement, which is potentially quite different from western populations.

METHODS

In this multicenter prospective cohort study, the anticoagulation and monitoring strategy data was acquired from 25 773 in-hospital patients in 35 medical centers and 20 519 patients in outpatient clinic in 11 medical centers from January 1st, 2011 to December 31th, 2015.

RESULTS

As for in-hospital patients, mean age of study population was (48.6±11.2) years old; main etiology of valve pathology was rheumatic (87.5%) origin among study cohort; 94.8% of study population received mechanical valve implantation; international normalized ratio (INR) monitoring (in all the study centers) and low-intensity anticoagulation strategy (31 hospitals chose target INR range of 1.5-2.5, and actual values of INR among 89.2% of 100 069 in-hospital monitoring samples were 1.5-2.5), with mean actual INR values of 1.84±0.53, and warfarin dosage of (2.82±0.93) mg/d were widely adopted among the study centers; strategies of in-hospital warfarin administration were similar in all the study centers; complication rates of low-intensity anticoagulation strategy were low in severe hemorrhage (0.02%), thrombosis (0.05%), and thromboembolism (0.05%) events, without anticoagulation-related death.As for 18 974 outpatient clinic patients, the follow-up rate was 92.47%, with a total of 30 012 patient-years (Pty). Anticoagulation-related morbidity and mortality rates were 0.67% and 0.15% Pty; major hemorrhage morbidity and mortality rates were 0.25% and 0.13% Pty; thromboembolism morbidity and mortality rates were 0.45% and 0.03% Pty.The mean dosage of warfarin daily dosage was (2.85±1.23) mg/d and INR value was 1.82±0.57.No significant regional difference in the intensity of anticoagulation therapy was noted during the study.

CONCLUSIONS

INR can be used as a normalized indicator for intensity of anticoagulation therapy in China.The optimal anticoagulation intensity with INR range from 1.5 to 2.5 is safe and effective for Chinese patients with heart valve replacement, and there is no significant regional difference in the intensity of anticoagulation therapy.

Abstract P3-04-26: Establishment and characterization of ST941/C; an ESR1-mutant ER+ breast cancer cell line and xenograft from a patient with acquired resistance to endocrine therapy

Background: The estrogen receptor (ERα) plays an integral role in the progression of luminal type breast cancers and while targeted endocrine therapies provide effective initial treatment many patients develop acquired resistance to treatment even with continued ER receptor expression. Recently studies identified ER mutations as a possible mechanism for acquired resistance and several activating point mutations have been identified including Y537S (ESR1Y537S) resulting in hormone independent proliferation in preclinical studies. However, lack of validated ESR1-mutant cell lines has limited detailed mechanistic studies of these mutations in endocrine-resistant ER+ breast cancer. Previously we established and evaluated a patient derived xenograft (PDX) designated ST941 representing ESR1Y537S-mutated ER+ breast cancer (Wick et al, SABCS 2015). To better understand the role of ESR1-mutations in endocrine resistant breast cancer we established an immortalized cell line from ST941 designated ST941/C to use for in vitro mechanistic assays and correlative in vivo studies.

Methods: The ST941/C cell line was generated from harvested low-passage ST941 PDX tissue using published methods. Once established the line was characterized by immunohistochemistry and NGS and its tumorigenicity assessed. Drug sensitivity studies were carried out evaluating relevant endocrine and chemotherapy agents and results compared with in vivo drug studies. Timepoints for cell proliferation assays were Days 4, 7 and 10 following cell plating using standard MTS assay. Endpoints for in vivo studies were a mean group tumor volume of ~1 cm3 or sixty days following treatment initiation.

Results: Subcutaneous cell injection into athymic nude mice produced xenografts which grew in the absence of exogenous hormone. The ST941/C cell line and resulting xenograft retained immunohistologic and NGS characteristics of the parent model including receptor expression and ER mutation. Both the cell line and xenograft were insensitive to most endocrine therapies including tamoxifen, fulvestrant and aromatase inhibitors and reported correlative activity towards docetaxel and other chemotherapies.

Conclusion: We have established and evaluated an ESR1-mutant cell line designated ST941/C which is tumorigenic in nude mice and potentially useful for mechanistic and correlative in vivo studies to better understand acquired resistance in endocrine-treated ER+ breast cancer.

Citation Format: Wick MJ, Diaz A, Thomas M, Moriarty A, Quinn M, Guerra M, Zhu P, Smith P, Tolcher AW, Puyang X, Patnaik A, Korpal M, Rasco D, Papadopoulos KP. Establishment and characterization of ST941/C; an ESR1-mutant ER+ breast cancer cell line and xenograft from a patient with acquired resistance to endocrine therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-04-26.

Enrichment and Molecular Analysis of Breast Cancer Disseminated Tumor Cells from Bone Marrow Using Microfiltration

Purpose

Molecular characterization of disseminated tumor cells (DTCs) in the bone marrow (BM) of breast cancer (BC) patients has been hindered by their rarity. To enrich for these cells using an antigen-independent methodology, we have evaluated a size-based microfiltration device in combination with several downstream biomarker assays.

Methods

BM aspirates were collected from healthy volunteers or BC patients. Healthy BM was mixed with a specified number of BC cells to calculate recovery and fold enrichment by microfiltration. Specimens were pre-filtered using a 70 μm mesh sieve and the effluent filtered through CellSieve microfilters. Captured cells were analyzed by immunocytochemistry (ICC), FISH for HER-2/neu gene amplification status, and RNA in situ hybridization (RISH). Cells eluted from the filter were used for RNA isolation and subsequent qRT-PCR analysis for DTC biomarker gene expression.

Results

Filtering an average of 14×10⁶ nucleated BM cells yielded approximately 17–21×10³ residual BM cells. In the BC cell spiking experiments, an average of 87% (range 84–92%) of tumor cells were recovered with approximately 170- to 400-fold enrichment. Captured BC cells from patients co-stained for cytokeratin and EpCAM, but not CD45 by ICC. RNA yields from 4 ml of patient BM after filtration averaged 135ng per 10 million BM cells filtered with an average RNA Integrity Number (RIN) of 5.3. DTC-associated gene expression was detected by both qRT-PCR and RISH in filtered spiked or BC patient specimens but, not in control filtered normal BM.

Conclusions

We have tested a microfiltration technique for enrichment of BM DTCs. DTC capture efficiency was shown to range from 84.3% to 92.1% with up to 400-fold enrichment using model BC cell lines. In patients, recovered DTCs can be identified and distinguished from normal BM cells using multiple antibody-, DNA-, and RNA-based biomarker assays.

Rosenbluth Separation of the π^{0} Electroproduction Cross Section

We present deeply virtual π^{0} electroproduction cross-section measurements at x_{B}=0.36 and three different Q^{2} values ranging from 1.5 to 2  GeV^{2}, obtained from Jefferson Lab Hall A experiment E07-007. The Rosenbluth technique is used to separate the longitudinal and transverse responses. Results demonstrate that the cross section is dominated by its transverse component and, thus, is far from the asymptotic limit predicted by perturbative quantum chromodynamics. Nonetheless, an indication of a nonzero longitudinal contribution is provided by the measured interference term σ_{LT}. Results are compared with several models based on the leading-twist approach of generalized parton distributions (GPDs). In particular, a fair agreement is obtained with models in which the scattering amplitude includes convolution terms of chiral-odd (transversity) GPDs of the nucleon with the twist-3 pion distribution amplitude. This experiment, together with previous extensive unseparated measurements, provides strong support to the exciting idea that transversity GPDs can be accessed via neutral pion electroproduction in the high-Q^{2} regime.