Abstract P4-03-10: Clinical observation of lapatinib versus continued use of trastuzumab for trastuzumab-resistant HER2-positive advanced breast cancer

Objective: To compare the efficacy, adverse effects and survival of lapatinib versus continued use of trastuzumab for trastuzumab-resistant human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer.

Methods: Patients who began the regimen of lapatinib plus capecitabine (LC or LX) or trastuzumab beyond progression (TBP) between May 2013 and October 2016 were selected from the First Affiliated Hospital of Nanjing Medical University. All of their clinical data were recorded, including age, performance status, hormone receptor status, metastatic site, primary or acquired trastuzumab resistance, previous treatment and so on. They were followed up until death or April 30, 2017. The primary end point was progression-free survival (PFS). The efficacy and safety of the two regimens were evaluated according to Response Evaluation Criteria In Solid Tumors (RECIST) version 1.1 and Common Terminology Criteria for Adverse Events (CTCAE) version 4.0, respectively. Data were analyzed by SPSS version 19.0.

Results: In total, 95 patients were identified, including 40 treated with LX and 55 with TBP. Median follow-up time was 16.0 months. There was no difference in objective response rate (ORR) and disease control rate (DCR) between the two groups. By the end of follow-up, median PFS was 6.3 months with LX and 7.1 months with TBP (P=0.676). In patients with primary trastuzumab resisitance, longer PFS was observed in LX group compared with TBP group [median PFS: 8.0 months vs. 5.3 months, hazard ratio (HR)=0.416, 95% confidence interval (CI): 0.177-0.981, P=0.038]. The incident rate of new brain metastases during treatment was 2.5% in LX group and 10.9% in TBP group, respectively (P=0.233). Both regimens showed similar outcomes in baseline brain metastases. Grade 3-4 adverse effects included diarrhea 7.5%(3/40) and hand-foot syndrome 12.5%(5/40) in LX group, along with leukopenia 18.2%(10/55), thrombocytopenia 9.1%(5/55) and nausea/vomiting 3.6%(2/55) in TBP group.

Conclusion: LX and TBP were similarly effective for patients with HER2-positive breast cancer progressing on prior trastuzumab-containing therapy. Both were well tolerated in general. Lapatinib tended to reduce the risk of disease progression in patients resistant to trastuzumab primarily. LX or TBP after local treatment appeared to show no difference in treating patients with brain metastases.

Citation Format: Yin Y, Li W, Huang X, Wang J, Fu Z, Li J. Clinical observation of lapatinib versus continued use of trastuzumab for trastuzumab-resistant HER2-positive advanced 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 P4-03-10.

Vitamin A maintains the airway epithelium in a murine model of asthma by suppressing glucocorticoid-induced leucine zipper

BACKGROUND

The effects of glucocorticoids (GCs) on the repair of the airway epithelium in asthma are controversial, and we previously reported that the GC dexamethasone (Dex) inhibits the repair of human airway epithelial cells and that this process is mediated by glucocorticoid-induced leucine zipper (GILZ) through MAPK-ERK signaling in vitro. Vitamin A (VA) is involved in the regulation of the MAPK-ERK pathway but has not been widely supplied during asthma treatment. It is unclear whether VA attenuates the negative regulation of GILZ on the MAPK-ERK pathway and maintains airway epithelium integrity during asthma treatment.

METHODS

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) and subsequently treated with Dex, VA or intranasal inhalation of adenovirus sh-GILZ vectors. Indexes of airway epithelium integrity, including pathological alterations, pulmonary EGFR expression and airway hyperresponsiveness (AHR), were then measured. The expression of GILZ and key components of activated MAPK-ERK signals (p-Raf-1, p-MEK, and p-Erk1/2) were also detected.

RESULTS

Dex failed to relieve OVA-induced asthma airway epithelium injury, as assessed through H&E staining, EGFR expression and AHR. Moreover, in the OVA-challenged mice treated with Dex, GLIZ expression was increased, whereas the ratios of p-Raf-1/Raf-1, p-MEK/MEK and p-Erk1/2/Erk1/2 were significantly decreased. Further study indicated that GILZ expression was decreased and that the ratios of p-Raf-1/Raf-1, p-MEK/MEK and p-Erk1/2/Erk1/2 were up-regulated in the GILZ-silenced OVA-challenged mice and VA-fed OVA-challenged mice, independent of Dex treatment. The airway epithelium integrity of the OVA-challenged mice was maintained by treatment with both VA and Dex.

CONCLUSIONS

Vitamin A maintained the Dex-treated asthma airway epithelium via the down-regulation of GILZ expression and the activation MAPK-ERK signaling, and these effects might contribute to improving the effects of GC therapeutics on asthma.

Changes in microRNA expression in response to Schistosoma japonicum infection

Schistosomiasis japonicum is one of the most serious zoonotic diseases in the world. There is increasing evidence to show that host miRNAs are modulated following Schistosoma japonicum infection, and some of these miRNAs may play important regulatory roles in response to schistosome infection. Several host miRNAs have been identified and shown to be potential diagnostic biomarkers or novel therapeutic targets for schistosomiasis. These studies have paved the way to a better understanding of the mechanisms of schistosome-host interaction and may facilitate the development of novel approaches to the control of the disease.

Ibuprofen does not reverse ventilatory acclimatization to chronic hypoxia

Ventilatory acclimatization to hypoxia involves an increase in the acute hypoxic ventilatory response that is blocked by non-steroidal anti-inflammatory drugs administered during sustained hypoxia. We tested the hypothesis that inflammatory signals are necessary to sustain ventilatory acclimatization to hypoxia once it is established. Adult, rats were acclimatized to normoxia or chronic hypoxia (CH, [Formula: see text] =70Torr) for 11-12days and treated with ibuprofen or saline for the last 2days of hypoxia. Ventilation, metabolic rate, and arterial blood gas responses to O₂ and CO₂ were not affected by ibuprofen after acclimatization had been established. Immunohistochemistry and image analysis showed acute (1h) hypoxia activated microglia in a medullary respiratory center (nucleus tractus solitarius, NTS) and this was blocked by ibuprofen administered from the beginning of hypoxic exposure. Microglia returned to the control state after 7days of CH and were not affected by ibuprofen administered for 2 more days of CH. In contrast, NTS astrocytes were activated by CH but not acute hypoxia and activation was not reversed by administering ibuprofen for the last 2days of CH. Hence, ibuprofen cannot reverse ventilatory acclimatization or astrocyte activation after they have been established by sustained hypoxia. The results are consistent with a model for microglia activation or other ibuprofen-sensitive processes being necessary for the induction but not maintenance of ventilatory acclimatization to hypoxia.

Arthropod Pests and Predators Associated With Bittersweet Nightshade, a Noncrop Host of the Potato Psyllid (Hemiptera: Triozidae)

Bittersweet nightshade (Solanum dulcamara L.) is a key noncrop host of the potato psyllid (Bactericera cockerelli Šulc), proposed to be a source of the psyllids that colonize potato (Solanum tuberosum L.) fields in the northwestern United States. Here, we describe the broader community of arthropod potato pests, and also predatory arthropods, found in bittersweet nightshade patches. Over 2 yr, we sampled arthropods in patches of this weed spanning the potato-growing region of eastern Washington State. The potato psyllid was the most abundant potato pest that we found, with reproduction of these herbivores recorded throughout much of the growing season where this was measured. Aphid, beetle, and thrips pests of potato also were collected on bittersweet nightshade. In addition to these herbivores, we found a diverse community of >40 predatory arthropod taxa. Spiders, primarily in the Families Dictynidae and Philodromidae, made up 70% of all generalist predator individuals collected. Other generalist predators included multiple species of predatory mites, bugs, and beetles. The coccinellid beetle Stethorus punctillum (Weise) was observed eating psyllid eggs, while the parasitoid wasp Tamarixia triozae (Burks) was observed parasitizing potato psyllid nymphs. Overall, our survey verified the role of bittersweet nightshade as a potato psyllid host, while suggesting that other potato pests also use these plants. At the same time, we found that bittersweet nightshade patches were associated with species-rich communities of natural enemies. Additional work is needed to directly demonstrate movement of pests, and perhaps also predators, from bittersweet nightshade to potato fields.

Small angle neutron scattering contrast variation reveals heterogeneities of interactions in protein gels

We propose a quantitative approach to probe the spatial heterogeneities of interactions in macromolecular gels, based on a combination of small angle X-ray (SAXS) and neutrons (SANS) scattering. We investigate the structure of model gluten protein gels and show that the gels display radically different SAXS and SANS profiles when the solvent is (at least partially) deuterated. The detailed analysis of the SANS signal as a function of the solvent deuteration demonstrates heterogeneities of sample deuteration at different length scales. The progressive exchange between the protons (H) of the proteins and the deuteriums (D) of the solvent is inhomogeneous and 60 nm large zones that are enriched in H are evidenced. In addition, at low protein concentration, in the sol state, solvent deuteration induces a liquid/liquid phase separation. Complementary biochemical and structure analyses show that the denser protein phase is more protonated and specifically enriched in glutenin, the polymeric fraction of gluten proteins. These findings suggest that the presence of H-rich zones in gluten gels would arise from the preferential interaction of glutenin polymers through a tight network of non-exchangeable intermolecular hydrogen bonds.

Micro-electrode array recordings reveal reductions in both excitation and inhibition in cultured cortical neuron networks lacking Shank3

Numerous risk genes have recently been implicated in susceptibility to autism and schizophrenia. Translating such genetic findings into disease-relevant neurobiological mechanisms is challenging due to the lack of throughput assays that can be used to assess their functions on an appropriate scale. To address this issue, we explored the feasibility of using a micro-electrode array (MEA) as a potentially scalable assay to identify the electrical network phenotypes associated with risk genes. We first characterized local and global network firing in cortical neurons with MEAs, and then developed methods to analyze the alternation between the network active period (NAP) and the network inactive period (NIP), each of which lasts tens of seconds. We then evaluated the electric phenotypes of neurons derived from Shank3 knockout (KO) mice. Cortical neurons cultured on MEAs displayed a rich repertoire of spontaneous firing, and Shank3 deletion led to reduced firing activity. Enhancing excitation with CX546 rescued the deficit in the spike rate in the Shank3 KO network. In addition, the Shank3 KO network produced a shorter NIP, and this altered network firing pattern was normalized by clonazepam, a positive modulator of the GABAA receptor. MEA recordings revealed electric phenotypes that displayed altered excitation and inhibition in the network lacking Shank3. Thus, our study highlights MEAs as an experimental framework for measuring multiple robust neurobiological end points in dynamic networks and as an assay system that could be used to identify electric phenotypes in cultured neuronal networks and to analyze additional risk genes identified in psychiatric genetics.

Peroxynitrite decomposition catalyst prevents matrix metalloproteinase-9 activation and neurovascular injury after hemoglobin injection into the caudate nucleus of rats

Hemoglobin (Hb) is a major constituent of blood and a potent mediator of oxidative or nitrative stress after intracerebral hemorrhage (ICH). Our previous study demonstrated that Hb could induce abundant peroxynitrite (ONOO(-)) formation in vivo, which may be involved in the blood-brain barrier (BBB) disruption, however, the drug intervention is absent and also the underlying mechanism. Using an experimental stroke model by injecting Hb into the caudate nucleus of male Sprague-Dawley rats, we assessed the role of ONOO(-) decomposition catalyst, 5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrinato iron(III) [FeTPPS] in the activation of MMP-9 and Hb-induced neurovascular injuries. 3-Nitrotyrosine (3-NT, as an index of ONOO(-) formation) and NF-κB expression was measured by western blot (WB) and immunohistochemistry (IHC)/immunofluorescence (IF). Activity of MMP was evaluated by in situ zymography. Neurovascular injury was assessed using zonula occludens-1 (ZO-1) by WB and IF, fibronectin (FN) and neuron-specific nuclear protein (NeuN) IHC. Perihematomal cell death was determined by TUNEL assay. Behavioral outcome was measured by modified neurological severity score (mNSS) test. At the injured striata, profuse 3-NT was produced and mainly expressed in neutrophils and microglia/macrophages. 3-NT formation significantly colocalized with nuclear factor-κB (NF-κB) expression. In situ zymography showed that gelatinase activity was mostly co-localized with neurons and blood vessel walls and partly with neutrophils and microglia/macrophages. Enhanced 3-NT production, NF-κB induction and MMP-9 activation were obviously reduced after FeTPPS treatment. Hb-induced injury to tight junction protein (ZO-1), basal lamina of FN-immunopositive microvasculature and neural cells was evidently ameliorated by FeTPPS. In addition, apoptotic cell numbers as well as behavioral deficits were also improved. The present study shows that the administration of the ONOO(-) decomposition catalyst FeTPPS protects against Hb-induced neurovascular injuries and improves neurological function, which possibly in part by suppressing MMP-9 activation.

Comparison of molar intrusion efficiency and bone density by CT in patients with different vertical facial morphology

The purpose of this study is to examine the relationship between molar intrusion efficiency and bone density in patients with different vertical facial morphology. Thirty-six female patients, with overerupted upper first molars, were divided into two groups according to mandiblular plane angle (FH-MP): hyperdivergent, FH-MP>30° (G1), hypodivergent, FH-MP<22° (G2). Mini-screw implants with elastic chains were used to intrude upper first molars. Spiral CT was used to measure the intrusion degree of upper first molar and bone density, and molar intrusion efficiency was calculated as amount/duration (mm month(-1) ). In addition, each tooth was divided into three portions (cervical, furcation and apical) to measure the bone density. It was found in this study that treatment duration was 3·13 and 4·71 months in G1 and G2 and that the intrusion efficiency was 1·57 and 0·81 in G1 and G2 with significant difference (P < 0·05). There were significant differences in cervical, furcation and apical bone density between two groups (P < 0·05). The bone density was significantly reduced after molar intrusion. In addition, the bone density change was greater in G1 than in G2 (P < 0·05). It was concluded that molars were more easily to be intruded in hyperdivergent than in hypodivergent patients. The difference of bone density and bone density changes during intrusion may account for the variation of molar intrusion efficiency.

Paradoxical immune reconstitution inflammatory syndrome associated with cryptococcal meningitis in China: a 5-year retrospective cohort study

We performed a retrospective cohort study of hospitalised cryptococcal meningitis (CM) patients at a single centre to evaluate the clinical epidemiological features of paradoxical cryptococcal-related immune reconstitution inflammatory syndrome (CM-IRIS) in a setting in China. A total of 154 AIDS patients with CM were involved, and 17.5% experienced IRIS at a median of 27 days after initiation of antiretroviral therapy (ART). Overall, 3 deaths were directly attributed to IRIS. The occurrences of CM-IRIS were independently associated with the pre-ART CD4+count, pre-C-reactive protein level, and the timing of ART initiation.

Blood versus crystalloid cardioplegia for pediatric cardiac surgery: a meta-analysis

OBJECTIVE

Blood and crystalloid cardioplegia are the main myocardial protective solutions used in pediatric cardiac surgery. However, the effectiveness of these two solutions on myocardial metabolism, reperfusion injury and clinical outcomes in pediatric patients is still under debate. The purpose of this meta-analysis was to compare the efficacy of these two cardioplegia solutions in pediatric cardiac surgery.

METHODS

Keyword searches were performed on PUBMED, EMBASE and The Cochrane Library for randomized, controlled, clinical studies which were primarily comparing blood and crystalloid cardioplegia in pediatric cardiac surgery and provided data of postoperative cardiac troponin I (cTnI), lactate, mechanical ventilation time, length of intensive care unit (ICU) stay and inotropic support. Databases were searched from 1966 to June 2013 and were restricted to peer-reviewed English language publications of human subjects. We summarized the combined results of the data as mean difference (MD, when outcome measurements were made on the same scale) or standard mean difference (SMD, when the studies assess the same outcome with different scales), with 95% confidence intervals.

RESULTS

Five studies were identified, with a total of 323 patients. Lactate level after cardiopulmonary bypass (CPB) was significantly lower after blood cardioplegia compared with crystalloid cardioplegia (SMD 1.09, 95%CI 0.12 to 2.06, p=0.03); cTnI release postoperatively at 4-6 h (MD 0.92 ng/ml, 95%CI -0.13 to 1.97, p=0.09), 12 h (MD 0.2 ng/ml, 95% CI -0.43 to 0.84, p=0.53) and 24 h (MD 0.98 ng/ml, 95%CI -0.26 to 2.22, p=0.12) was not significantly different between the groups; ventilation duration (MD 5.15 hours, 95%CI -7.51 to 17.81, p=0.42) and length of ICU stay (SMD -0.3, 95%CI -0.80 to 0.21, p=0.25) were not significantly different between the groups either.

CONCLUSION

Myocardial metabolism was better in the blood cardioplegia group compared with the crystalloid cardioplegia group. However, there was no evidence of improvement in myocardial damage or clinical outcome for either cardioplegia solution.