Efficacy and safety of intrathecal pemetrexed for TKI-failed leptomeningeal metastases from EGFR+ NSCLC: an expanded, single-arm, phase II clinical trial

BACKGROUND

This study aimed to evaluate the efficacy and safety of intrathecal pemetrexed (IP) for treating patients with leptomeningeal metastases (LM) from non-small-cell lung cancer (NSCLC) who progressed from epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) treatment in an expanded, prospective, single-arm, phase II clinical study (ChiCTR1800016615).

PATIENTS AND METHODS

Patients with confirmed NSCLC-LM who progressed from TKI received IP (50 mg, day 1/day 5 for 1 week, then every 3 weeks for four cycles, and then once monthly) until disease progression or intolerance. Objectives were to assess overall survival (OS), response rate, and safety. Measurable lesions were assessed by investigator according to RECIST version 1.1. LM were assessed according to the Response Assessment in Neuro-Oncology (RANO) criteria.

RESULTS

The study included 132 patients; 68% were female and median age was 52 years (31-74 years). The median OS was 12 months (95% confidence interval 10.4-13.6 months), RANO-assessed response rate was 80.3% (106/132), and the most common adverse event was myelosuppression (n = 42; 31.8%), which reversed after symptomatic treatment. The results of subgroup analysis showed that absence of brain parenchymal metastasis, good Eastern Cooperative Oncology Group score, good response to IP treatment, negative cytology after treatment, and patients without neck/back pain/difficult defecation had longer survival. Gender, age, previous intrathecal methotrexate/cytarabine, and whole-brain radiotherapy had no significant influence on OS.

CONCLUSIONS

This study further showed that IP is an effective and safe treatment method for the EGFR-TKI-failed NSCLC-LM, and should be recommended for these patients in clinical practice and guidelines.

Survival impact of post-operative immunotherapy in resected stage III cutaneous melanomas in the checkpoint era

BACKGROUND

Checkpoint inhibitors have shown improvement in recurrence-free survival in the post-operative setting for node-positive melanoma and were first approved in late 2015. However, single-agent checkpoint therapies have yet to show benefit to overall survival (OS) for lower-risk stage III cancers. We evaluated the OS benefit of post-operative immunotherapy in the National Cancer Database (NCDB).

PATIENTS AND METHODS

Patient cases were selected from the NCDB 2020 Participant Use File. Patients diagnosed with stage III cutaneous melanoma between 2016 and 2019 who underwent definitive resection for their melanoma were included. OS between those who received post-operative immunotherapy within 84 days of surgery and those who did not was analyzed by the Kaplan-Meier method. Demographic and clinical characteristics between the two groups were compared via Cox proportional hazard models.

RESULTS

14 978 patients with stage III melanoma were included. Of those, 34.9% (n = 5234) received post-operative immunotherapy and 65.1% (n = 9744) did not. Using the American Joint Committee on Cancer version 8 (AJCCv8) staging, 36-month survival was significantly higher in patients who received post-operative immunotherapy compared to no post-operative systemic therapy in those diagnosed with stage IIIB (88.0% versus 84.7%, P = 0.011), IIIC (75.6% versus 68.1%, P < 0.001), or IIID (59.2% versus 48.4%, P = 0.002). No significant improvement in 36-month survival was seen in patients who received post-operative immunotherapy in patients with stage IIIA disease (93.0% versus 92.2%, P = 0.218).

CONCLUSIONS

Post-operative immunotherapy had an OS benefit in patients with AJCCv8 stage IIIB, IIIC, and IIID disease, but had no significant survival benefit for patients with stage IIIA melanomas.

FLZ13 interacts with FLC and ABI5 to negatively regulate flowering time in Arabidopsis

The transition from vegetative to reproductive growth, known as flowering, is a critical developmental process in flowering plants to ensure reproductive success. This process is strictly controlled by various internal and external cues; however, the underlying molecular regulatory mechanisms need to be further characterized. Here, we report a plant-specific protein, FCS-LIKE ZINC FINGER PROTEIN 13 (FLZ13), which functions as a hitherto unknown negative modulator of flowering time in Arabidopsis thaliana. Biochemical analysis showed that FLZ13 directly interacts with FLOWERING LOCUS C (FLC), a major flowering repressor, and that FLZ13 largely depends on FLC to repress the transcription of two core flowering integrators: FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1. In addition, FLZ13 works together with ABSCISIC ACID INSENSITIVE 5 to activate FLC expression to delay flowering. Taken together, our findings suggest that FLZ13 is an important component of the gene regulatory network for flowering time control in plants.

The Clinical Practice and Dosimetric Outcome of the Manual Adaptive Planning during Definitive Radiotherapy Treatment for Cervical Cancer

PURPOSE/OBJECTIVE(S)

Organ motion is challenging during primary definitive external beam radiotherapy in locally advanced cervical cancer (LACC). Our study evaluated the manual adaptive planning approach three weeks after the treatment started, compared the dosimetric consequences of the manual adaptive plans to the scheduled plans, and explored the clinical factors predicting patients suitable for this replanning strategy.

MATERIALS/METHODS

We analyzed 82 patients receiving primary definitive external beam radiotherapy with weekly online cone-beam computed tomography (CBCT)-based monitoring. The re-CT simulation was performed during treatment to develop a new plan (manual adaptive plan) due to a significant deviation of the clinical target volume (CTV). To evaluate the dosimetric benefit, D98, homogeneity index (HI) and conformity index (CI) for the planning target volume (PTV), as well as D2cc of the bowel, bladder, sigmoid and rectum were compared between the manual adaptive plans and the scheduled ones. The clinical factors influencing target motion throughout treatment were analyzed by chi-square test and logistic regression analysis.

RESULTS

The re-CT simulation was performed after 15 fractions during treatment to develop the manual adaptive plan in 41 patients. The median CI and HI of the manual adaptive plan were significantly superior to the scheduled one (P = 0.001, 0.003, respectively), demonstrating a better dose coverage of the target volume. Compared to the scheduled plans, D98 of the manual adaptive plans increased by 3.3% (P = 0.0002), the average of D2cc to the rectum, bladder decreased 0.267Gy (P = 0.0049) and 0.321Gy (P = 0.0146), respectively. In addition, the chi-square test demonstrated that age (P = 0.024), primary tumor volume (P = 0.015), and parametrial infiltration (P = 0.022) were the clinical factors influencing target motion throughout treatment. Multivariate analysis further identified the large tumor volume (≥50cm3, OR = 3.254, P = 0.039) and parametrial infiltration (OR = 3.376, P = 0.018) as the independent risk factors.

CONCLUSION

We found the most significant organ motion happened after 15 fractions during treatment. The manual adaptive planning of definitive radiotherapy improved the dose coverage and decreased the volume of organs at risk of receiving clinically significant doses of RT in patients with LACC. Patients with bulky mass or with parametrial infiltration were highly suggested to receive manual adaptive planning after 15 fractions during definitive radiotherapy, a timesaving strategy compared to the daily online adaptive radiotherapy without compromising the target dose coverage.

A positive feedback regulation of SnRK1 signaling by autophagy in plants

SnRK1, an evolutionarily conserved heterotrimeric kinase complex that acts as a key metabolic sensor in maintaining energy homeostasis in plants, is an important upstream activator of autophagy that serves as a cellular degradation mechanism for the healthy growth of plants. However, whether and how the autophagy pathway is involved in regulating SnRK1 activity remains unknown. In this study, we identified a clade of plant-specific and mitochondria-localized FCS-like zinc finger (FLZ) proteins as currently unknown ATG8-interacting partners that actively inhibit SnRK1 signaling by repressing the T-loop phosphorylation of the catalytic α subunits of SnRK1, thereby negatively modulating autophagy and plant tolerance to energy deprivation caused by long-term carbon starvation. Interestingly, these AtFLZs are transcriptionally repressed by low-energy stress, and AtFLZ proteins undergo a selective autophagy-dependent pathway to be delivered to the vacuole for degradation, thereby constituting a positive feedback regulation to relieve their repression of SnRK1 signaling. Bioinformatic analyses show that the ATG8-FLZ-SnRK1 regulatory axis first appears in gymnosperms and seems to be highly conserved during the evolution of seed plants. Consistent with this, depletion of ATG8-interacting ZmFLZ14 confers enhanced tolerance, whereas overexpression of ZmFLZ14 leads to reduced tolerance to energy deprivation in maize. Collectively, our study reveals a previously unknown mechanism by which autophagy contributes to the positive feedback regulation of SnRK1 signaling, thereby enabling plants to better adapt to stressful environments.

[Network meta-analysis comparing the clinical outcomes and safety of robotic, laparoscopic, and transanal total rectal mesenteric resection for rectal cancer]

Objective: To methodically assess the clinical effectiveness and safety of robot-assisted total rectal mesenteric resection (RTME), laparoscopic-assisted total rectal mesenteric resection (laTME), and transanal total rectal mesenteric resection (taTME). Methods: A computer search was conducted on PubMed, Embase, Cochrane Library, and Ovid databases to identify English-language reports published between January 2017 and January 2022 that compared the clinical efficacy of the three surgical procedures of RTME, laTME, and taTME. The quality of the studies was evaluated using the NOS and JADAD scales for retrospective cohort studies and randomized controlled trials, respectively. Direct meta-analysis and reticulated meta-analysis were performed using Review Manager software and R software, respectively. Results: Twenty-nine publications comprising 8,339 patients with rectal cancer were ultimately included. The direct meta-analysis indicated that the length of hospital stay was longer after RTME than after taTME, whereas according to the reticulated meta-analysis the length of hospital stay was shorter after taTME than after laTME (MD=-0.86, 95%CI: -1.70 to -0.096, P=0.036). Moreover, the incidence of anastomotic leak was lower after taTME than after RTME (OR=0.60, 95%CI: 0.39 to 0.91, P=0.018). The incidence of intestinal obstruction was also lower after taTME than after RTME (OR=0.55, 95%CI: 0.31 to 0.94, P=0.037). All of these differences were statistically significant (all P<0.05). There were no statistically significant differences between the three surgical procedures regarding the number of lymph nodes cleared, length of the inferior rectal margin, or rate of positive circumferential margins (all P>0.05). An inconsistency test using nodal analysis revealed no statistically significant differences between the results of direct and indirect comparisons of the six outcome indicators (all P>0.05). Furthermore, we detected no significant overall inconsistency between direct and indirect evidence. Conclusion: taTME has advantages over RTME and laTME, in terms of radical and surgical short-term outcomes in patients with rectal cancer.

[Electroencephalographic microstates in vestibular schwannoma patients with tinnitus]

OBJECTIVE

To explore the biomarkers of tinnitus in vestibular schwannoma patients using electroencephalographic (EEG) microstate technology.

METHODS

The EEG and clinical data of 41 patients with vestibular schwannoma were collected. All the patients were evaluated by SAS, SDS, THI and VAS scales. The EEG acquisition time was 10-15 min, and the EEG data were preprocessed and analyzed using MATLAB and EEGLAB software package.

RESULTS

Of the 41 patients with vestibular schwannoma, 29 patients had tinnitus and 12 did not have tinnitus, and their clinical parameters were comparable. The average global explanation variances of the non-tinnitus and tinnitus groups were 78.8% and 80.1%, respectively. The results of EEG microstate analysis showed that compared with those without tinnitus, the patients with tinnitus had an increased frequency (P=0.033) and contribution (P=0.028) of microstate C. Correlation analysis showed that THI scale scores of the patients were negatively correlated with the duration of microstate A (R=-0.435, P=0.018) and positively with the frequencies of microstate B (R=0.456, P=0.013) and microstate C (R=0.412, P=0.026). Syntax analysis showed that the probability of transition from microstate C to microstate B increased significantly in vestibular schwannoma patients with tinnitus (P=0.031).

CONCLUSION

EEG microstate features differ significantly between vestibular schwannoma patients with and without tinnitus. This abnormality in patients with tinnitus may reflect the potential abnormality in the allocation of neural resources and the transition of brain functional activity.

Synergistic effects of electroacupuncture and bone marrow stromal cells transplantation therapy in ischemic stroke

OBJECTIVE

Animal studies and clinical trials demonstrated the effectiveness of a combination of transplanted bone marrow stromal cells (BMSC) and electroacupuncture (EA) treatment in improving neurological deficits. However, the ability of the BMSC-EA treatment to enhance brain repair processes or the neuronal plasticity of BMSC in ischemic stroke model is unclear. The purpose of this study was to investigate the neuroprotective effects and neuronal plasticity of BMSC transplantation combined with EA in ischemic stroke.

MATERIALS AND METHODS

A male Sprague-Dawley (SD) rat middle cerebral artery occlusion (MCAO) model was used. Intracerebral transplantation of BMSC, transfected with lentiviral vectors expressing green fluorescent protein (GFP), was performed using a stereotactic apparatus after modeling. MCAO rats were treated with BMSC injection alone or in combination with EA. After the treatment, proliferation and migration of BMSC were observed in different groups by fluorescence microscopy. Quantitative real-time PCR (qRT-PCR), Western blotting, and immunohistochemistry were performed to examine changes in the levels of neuron-specific enolase (NSE) and nestin in the injured striatum.

RESULTS

Epifluorescence microscopy revealed that most BMSC in the cerebrum were lysed; few transplanted BMSC survived, and some living cells migrated to areas around the lesion site. NSE was overexpressed in the striatum of MCAO rats, illustrating the neurological deficits caused by cerebral ischemia-reperfusion. The combination of BMSC transplantation and EA attenuated the expression of NSE, indicating nerve injury repair. Although the qRT-PCR results showed that BMSC-EA treatment elevated nestin RNA expression, less robust responses were observed in other tests.

CONCLUSIONS

Our results show that the combination treatment significantly improved restoration of neurological deficits in the animal stroke model. However, further studies are required to see if EA could promote the rapid differentiation of BMSC into neural stem cells in the short term.

Association between hepatitis C infection during pregnancy with maternal and neonatal outcomes: a systematic review and meta-analysis

OBJECTIVE

Studies of possible implications of the maternal hepatitis C virus (HCV) infection in terms of intrauterine fetal growth restriction (IUGR), preterm birth (PTB), low birth weight (LBW) infants, premature rupture of membranes (PROM), maternal and neonatal mortality are limited and inconclusive. Our study aims to assess the impact of HCV on maternal and neonatal outcomes.

MATERIALS AND METHODS

Systematic literature search was done in PubMed, Scopus, and Google Scholar, Cochrane Library, and TRIP databases for all observational studies published from 1st January 1950 to 15th October 2022. The pooled odds ratio (OR) or risk ratio (RR) with a 95% confidence interval (CI) was estimated. STATA version 12.0 software was used for analysis. Heterogeneity among the included articles was evaluated by sensitivity, meta-regression, and publication bias analyses.

RESULTS

A total of 14 studies involving 12,451 HCV (+) and 56,42,910 HCV (-) pregnant women were included in our meta-analysis. Maternal HCV during pregnancy was significantly associated with the increased risk of PTB (OR=1.66, 95% CI: 1.59-1.74), IUGR (OR=2.09, 95% CI: 2.04-2.14) and LBW (OR=1.96, 95% CI: 1.63-2.36) as compared to healthy pregnant women. Subgroup analysis based on ethnicity also suggested a strong association between maternal HCV infection and a higher risk of PTB in Asian and Caucasian populations. Maternal (RR=3.44, 95% CI: 1.85-6.41), as well as neonatal (RR=1.54, 95% CI: 1.18-2.02) mortality was significantly higher in HCV (+) cases.

CONCLUSIONS

Mothers with HCV infection had a markedly increased probability of PTB and/or IUGR and/or LBW. In clinical practice, standard care of treatment and proper monitoring are needed for the pregnant population with HCV infection. Our findings may provide useful information for selecting appropriate therapy methods for HCV-positive pregnant women.

Correlation between capsule endoscopy classification and CT lymphangiography of primary intestinal lymphangiectasia

AIM

To investigate the correlation between capsule endoscopy (CE) classification of primary intestinal lymphangiectasia (PIL) and computed tomography (CT) lymphangiography (CTL).

MATERIALS AND METHODS

A total of 52 patients with diagnosed PIL were enrolled. All patients were examined using CTL and small intestinal CE before surgery. CE assessments included the morphology, scope, colour, and size of lesions. CTL assessments included intestinal wall, lymphatic vessel dilatation, lymph fluid reflux, and lymphatic fistula. Patients were divided into three groups according to type diagnosed by CE, and the CTL characteristics were analysed among the groups.

RESULTS

CE showed 15 patients with type I, 27 with II, and 10 with type III. Intestinal wall thickening was observed in 15 type I, 21 type II, and seven type III. Pericardial effusion was observed in only three type I patients; the difference among types was statistically significant (p=0.02). Abnormal contrast agent distribution in the intestinal wall and mesentery was observed in 15 type II patients, and the difference was significantly greater than that of types I and III (p=0.02). Abnormal contrast agent distribution in the abdominal cavity was observed in 12 type II, and the difference was statistically significant (p=0.03).

CONCLUSION

The CE PIL classification reflects the extent and scope of intestinal mucosa lesions; CTL more systematically demonstrates abnormal lymphatic vessels or reflux, and its manifestations of PIL are related to the CE classification. The combination of CTL with CE is useful for accurately evaluating PIL, and provides guidance for preoperative assessment and treatment management of PIL patients.

The plant FYVE domain-containing protein FREE1 associates with microprocessor components to repress miRNA biogenesis

FYVE domain protein required for endosomal sorting 1 (FREE1), originally identified as a plant-specific component of the endosomal sorting complex required for transport (ESCRT) machinery, plays diverse roles either in endosomal sorting in the cytoplasm or in transcriptional regulation of abscisic acid signaling in the nucleus. However, to date, a role for FREE1 or other ESCRT components in the regulation of plant miRNA biology has not been discovered. Here, we demonstrate a nuclear function of FREE1 as a cofactor in miRNA biogenesis in plants. FREE1 directly interacts with the plant core microprocessor component CPL1 in nuclear bodies and disturbs the association between HYL1, SE and CPL1. Inactivation of FREE1 in the nucleus increases the binding affinity between HYL1, SE, and CPL1 and causes a transition of HYL1 from the inactive hyperphosphorylated version to the active hypophosphorylated form, thereby promoting miRNA biogenesis. Our results suggest that FREE1 has evolved as a negative regulator of miRNA biogenesis and provides evidence for a link between FYVE domain-containing proteins and miRNA biogenesis in plants.

Arabidopsis flowering integrator SOC1 transcriptionally regulates autophagy in response to long-term carbon starvation

Autophagy is a highly conserved, self-digestion process that is essential for plant adaptations to various environmental stresses. Although the core components of autophagy in plants have been well established, the molecular basis for its transcriptional regulation remains to be fully characterized. In this study, we demonstrate that SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1), a MADS-box family transcription factor that determines flowering transition in Arabidopsis, functions as a transcriptional repressor of autophagy. EMSAs, ChIP-qPCR assays, and dual-luciferase receptor assays showed that SOC1 can bind to the promoters of ATG4b, ATG7, and ATG18c via the conserved CArG box. qRT-PCR analysis showed that the three ATG genes ATG4b, ATG7, and ATG18c were up-regulated in the soc1-2 mutant. In line with this, the mutant also displayed enhanced autophagy activity, as revealed by increased autophagosome formation and elevated autophagic flux compared with the wild type. More importantly, SOC1 negatively affected the tolerance of plants to long-term carbon starvation, and this process requires a functional autophagy pathway. Finally, we found that SOC1 was repressed upon carbon starvation at both the transcriptional and protein levels. Overall, our study not only uncovers an important transcriptional mechanism that contributes to the regulation of plant autophagy in response to nutrient starvation, but also highlights novel cellular functions of the flowering integrator SOC1.

Transcriptome dissection of candidate genes associated with lentil seed quality traits

Lentils provide a rich plant-based protein source and staple food in many parts of the world. Despite numerous nutritional benefits, lentil seeds also possess undesirable elements, such as anti-nutritional factors. Understanding the genetic networks of seed metabolism is of great importance for improving the seed nutritional profile. We applied RNA sequencing analysis to survey the transcriptome of developing lentil seeds and compared this with that of the pod shells and leaves. In total, we identified 2622 genes differentially expressed among the tissues examined. Genes preferentially expressed in seeds were enriched in the Gene Ontology (GO) terms associated with development, nitrogen and carbon (N/C) metabolism and lipid synthesis. We further categorized seed preferentially expressed genes based on their involvement in storage protein production, starch accumulation, lipid and suberin metabolism, phytate, saponin and phenylpropanoid biosynthesis. The availability of transcript profile datasets on lentil seed metabolism and a roadmap of candidate genes presented here will be of great value for breeding strategies towards further improvement of lentil seed quality traits.

MLKs kinases phosphorylate the ESCRT component FREE1 to suppress abscisic acid sensitivity of seedling establishment

The FYVE domain protein required for endosomal sorting 1 (FREE1), which was previously identified as a plant-specific component of the endosomal sorting complex required for transport machinery, plays an essential role in endosomal trafficking. Moreover, FREE1 also functions as an important negative regulator in abscisic acid (ABA) signalling. Multiple phosphorylations and ubiquitination sites have been identified in FREE1, hence unveiling the factors involved in posttranslational regulation of FREE1 is critical for comprehensively understanding FREE1-related regulatory networks during plant growth. Here, we demonstrate that plant-specific casein kinase I members MUT9-like kinases 1-4 (MLKs 1-4)/Arabidopsis EL1-like 1-4 interact with and phosphorylate FREE1 at serine residue S582, thereby modulating the nuclear accumulation of FREE1. Consequently, mutation of S582 to non-phosphorylable residue results in reduced nuclear localization of FREE1 and enhanced ABA response. In addition, mlk123 and mlk134 triple mutants accumulate less FREE1 in the nucleus and display hypersensitive responses to ABA treatment, whereas overexpression of the nuclear-localized FREE1 can restore the ABA sensitivity of seedling establishment in mlks triple mutants. Collectively, our study demonstrates a previously unidentified function of MLKs in attenuating ABA signalling in the nucleus by regulating the phosphorylation and nuclear accumulation of FREE1.

The prevalence of Type-1 Brugada pattern in African American: a large population study from the United States

Funding Acknowledgements

Type of funding sources: None.

Background

The prevalence of Type-1 Brugada pattern in Caucasians and Asians have been estimated to be 20 and 180 per 100,000. However, the prevalence of Type-1 Brugada pattern in African Americans has never been studied.

Purpose

This study aims to identify the prevalence of Type-1 Brugada pattern in African Americans.

Methods

Medical records of African American patients ages 18 years old or older with at least one 12-lead electrocardiogram (ECG) performed at 16 hospitals from 5 states in a single healthcare system between January 1, 2011 to December 31, 2020 were included. The search engine software was used to identify patients with keywords (Brugada pattern, Brugada ECG, Brugada Type-1, or Brugada syndrome) documented in the electronic medical record. The 12-lead ECGs were retrospectively analyzed by 2 cardiologists. Any inconsistencies were reviewed by a third cardiac electrophysiologist. Type-1 Brugada pattern was diagnosed according to the recent Heart Rhythm Society Expert Consensus Statement.

Results

Among 43,116 African American patients, (46.9% males), 6 patients (mean age 44.8±13.9 years, 100% males) had Type-1 Brugada pattern documented on at least one 12-lead ECG. The prevalence of Type-1 Brugada pattern in this large patient population of African American was 13.9 per 100,000. None of the patients had major arrhythmic event at 6.7±4.7 years follow-up.

Conclusions

The prevalence of Type-1 Brugada pattern in African American is lower than Caucasian and Asian populations. The risk of major arrhythmic event of Type-1 Brugada pattern in African American appears to be low; however longer follow-up data is needed.

In premenopausal women with idiopathic osteoporosis, lower bone formation rate is associated with higher body fat and higher IGF-1

We examined serum IGF-1 in premenopausal IOP, finding relationships that were opposite to those expected: higher IGF-1 was associated with lower bone formation and higher body fat, and lower BMD response to teriparatide. These paradoxical relationships between serum IGF-1, bone, and fat may contribute to the mechanism of idiopathic osteoporosis in premenopausal women.

INTRODUCTION

Premenopausal women with idiopathic osteoporosis (IOP) have marked deficits in bone microarchitecture but variable bone remodeling. We previously reported that those with low tissue-level bone formation rate (BFR) are less responsive to teriparatide and have higher serum IGF-1, a hormone anabolic for osteoblasts and other tissues. The IGF-1 data were unexpected because IGF-1 is low in other forms of low turnover osteoporosis-leading us to hypothesize that IGF-1 relationships are paradoxical in IOP. This study aimed to determine whether IOP women with low BFR have higher IGF-1 and paradoxical IGF-1 relationships in skeletal and non-skeletal tissues, and whether IGF-1 and the related measures predict teriparatide response.

METHODS

This research is an ancillary study to a 24 month clinical trial of teriparatide for IOP. Baseline assessments were related to trial outcomes: BMD, bone remodeling.

SUBJECTS

 Premenopausal women with IOP(n = 34); bone remodeling status was defined by baseline cancellous BFR/BS on bone biopsy.

MEASURES

 Serum IGF-1 parameters, compartmental adiposity (DXA, CT, MRI), serum hormones, and cardiovascular-risk-markers related to fat distribution.

RESULTS

As seen in other populations, lower BFR was associated with higher body fat and poorer teriparatide response. However, in contrast to observations in other populations, low BFR, higher body fat, and poorer teriparatide response were all related to higher IGF-1: IGF-1 Z-score was inversely related to BFR at all bone surfaces (r =  - 0.39 to - 0.46; p < 0.05), directly related to central fat (p = 0.05) and leptin (p = 0.03). IGF-1 inversely related to 24 month hip BMD %change (r =  - 0.46; p = 0.01).

CONCLUSIONS

Paradoxical IGF-1 relationships suggest that abnormal or atypical regulation of bone and fat may contribute to osteoporosis mechanisms in premenopausal IOP.

Dynamic contrast-enhanced magnetic resonance imaging: A novel approach to assessing treatment in locally advanced esophageal cancer patients

Aims

This study aims to investigate the potential application of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to predict concurrent chemoradiation (CRT) in locally advanced esophageal carcinoma.

Patients and Methods

This study involved 33 patients with locally advanced esophageal cancer and treated with CRT. The patients underwent DCE-MRI before CRT (pre) and 3 weeks after starting CRT (mid). The patients were categorized into two groups: complete response (CR) and non-complete response (non-CR) after 3 months of treatment. The quantitative parameters of DCE-MRI (K^trans, Kep, and Ve), the changes and ratios of parameters (ΔK^trans, ΔKep, ΔVe, rΔK^trans, rΔKep, and rΔVe), and the relative ratio in the tumor area and a normal tube wall (rK^trans, rKep, and rVe) were calculated and compared between two timeframes in two groups, respectively. Moreover, the receiver operating characteristics (ROC) statistical analysis was used to assess the above parameters.

Results

We divided 33 patients into two groups: 22 in the CR group and 11 in the non-CR group. During the mid-CRT phase in the CR group, both K^trans and Kep rapidly decreased, while only Kep decreased in the non-CR group. The pre-K^trans and pre-Kep in the CR group were substantially higher compared to the non-CR group. Moreover, the rK^trans was also apparently observed as higher at pre-CRT in the CR group compared to the non-CR group. The ROC analysis demonstrated that the pre-K^trans could be the best parameter to evaluate the treatment performance (AUC = 0.74).

Conclusion

Pre-K^trans could be a promising parameter to forecast how patients with locally advanced esophageal cancer will respond to CRT.

[Effect of PPAR-γ agonist pioglitazone on the prolifeiration of malignant nesothelionma cells induced by HMGB1]

Objective: To investigate the effect and mechanism of PPAR-γ agonist Pioglitazone (PGZ) on the proliferation of malignant mesothelioma (MM) cells. Methods: In December 2019, MM cell lines MSTO-211H and NCI-H2452 were incubated with different final concentrations of PGZ (0, 10, 50, 100, 150, and 200 μmol/L) for different periods of time (24 h, 48 h, and 72 h) , and then the cell proliferation level was detected by CCK8 assay. After given various final concentration of PGZ (0, 10, 50, 100, 150, 200 μmol/L) the for 72 hours, the changes of number and morphology of MM cells were observed under an inverted microscope. The expressions of PPAR-γ and HMGB1 mRNA were determined by real-time fluorescence quantitative reverse transcription-polymerase chain reaction (qRT-PCR) after treatment of MM cells with PGZ of 0, 10, 50, 100 μmol/L for 72 h. The MM cells were treated with PGZ at concentration of 0, 100 μmol/L for 72 h, and the protein expressions of HMGB1 were examined using Western blotting and immunofluorescence; the protein expressions of Ki67 were assessed by immunohistochemistry. Results: The cell viability rate of MM cells was decreased after treated with PGZ (P<0.05) . Cell number in PGZ-treated group was significantly less than that in control group and morphology changes were observed under light microscope. QRT-PCR results revealed significantly increased PPAR-γ mRNA expression in the PGZ-treated group compared to the control group (P<0.05) . There was a significant decrease in the mRNA expression level of HMGB1 in the PGZ-treated group (100 μmol/L) as compared to the control group in MSTO-211H (P<0.05) ; however, the expression level of HMGB1 in NCI-H2452 was an increase or no significant differences (P>0.05) . Western blotting and immunofluorescence results showed that the protein expression of HMGB1 was reduced in the PGZ-treated group compared with the control group in MSTO-211H (P<0.05) , but the protein expression of that in NCI-H2452 was no significant differences (P>0.05) . Immunohistochemistry results showed increased expression of proliferation marker Ki-67. Conclusion: Pioglitazone suppresses the proliferation of MM cells through inhibition of HMGB1 by the activation of PPAR-γ.

Autophagy Mediates the Degradation of Plant ESCRT Component FREE1 in Response to Iron Deficiency

Multivesicular body (MVB)-mediated endosomal sorting and macroautophagy are the main pathways mediating the transport of cellular components to the vacuole and are essential for maintaining cellular homeostasis. The interplay of these two pathways remains poorly understood in plants. In this study, we show that FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1 (FREE1), which was previously identified as a plant-specific component of the endosomal sorting complex required for transport (ESCRT), essential for MVB biogenesis and plant growth, can be transported to the vacuole for degradation in response to iron deficiency. The vacuolar transport of ubiquitinated FREE1 protein is mediated by the autophagy pathway. As a consequence, the autophagy deficient mutants, atg5-1 and atg7-2, accumulate more endogenous FREE1 protein and display hypersensitivity to iron deficiency. Furthermore, under iron-deficient growth condition autophagy related genes are upregulated to promote the autophagic degradation of FREE1, thereby possibly relieving the repressive effect of FREE1 on iron absorption. Collectively, our findings demonstrate a unique regulatory mode of protein turnover of the ESCRT machinery through the autophagy pathway to respond to iron deficiency in plants.

A plant-unique ESCRT component, FYVE4, regulates multivesicular endosome biogenesis and plant growth

During evolution, land plants generated unique proteins that participate in endosomal sorting and multivesicular endosome (MVE) biogenesis, many of them with specific phosphoinositide-binding capabilities. Nonetheless, the function of most plant phosphoinositide-binding proteins in endosomal trafficking remains elusive. Here, we analysed several Arabidopsis mutants lacking predicted phosphoinositide-binding proteins and first identified fyve4-1 as a mutant with a hypersensitive response to high-boron conditions and defects in degradative vacuolar sorting of membrane proteins such as the borate exporter BOR1-GFP. FYVE4 encodes a plant-unique, FYVE domain-containing protein that interacts with SNF7, a core component of ESCRT-III (Endosomal Sorting Complex Required for Transport III). FYVE4 affects the membrane association of the late-acting ESCRT components SNF7 and VPS4, and modulates the formation of intraluminal vesicles (ILVs) inside MVEs. The critical function of FYVE4 in the ESCRT pathway was further demonstrated by the strong genetic interactions with SNF7B and LIP5. Although the fyve4-1, snf7b and lip5 single mutants were viable, the fyve4-1 snf7b and fyve4-1 lip5 double mutants were seedling lethal, with strong defects in MVE biogenesis and vacuolar sorting of ubiquitinated membrane proteins. Taken together, we identified FYVE4 as a novel plant endosomal regulator, which functions in ESCRTing pathway to regulate MVE biogenesis.

Therapeutic efficacy of dexmedetomidine on chronic obstructive pulmonary disease via downregulating lncRNA PACER

OBJECTIVE

The aim of the study was to clarify the therapeutic mechanism of Dexmedetomidine (DEX) on the chronic obstructive pulmonary disease (COPD) and its regulatory effect on long non-coding RNA (lncRNA) PACER.

PATIENTS AND METHODS

Serum level of PACER in COPD patients was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The diagnostic potential of PACER in COPD was assessed by plotting ROC curves. The in vivo COPD model was generated in rats by cigarette smoking exposure. Primary rat alveolar epithelial cells were isolated, purified and cultured. After overexpression of PACER in primary rat alveolar epithelial cells, proliferative and migratory abilities were assessed by cell counting kit-8 (CCK-8) and transwell assay, respectively. Subsequently, we detected changes in PACER expression, viability and migratory potentials in primary rat alveolar epithelial cells harvested from control rats, and those harvested from COPD rats and induced with either DEX or not. Rescue experiments were conducted to uncover the involvement of PP2A in PACER-regulated cell phenotypes.

RESULTS

PACER was upregulated in serum of COPD patients, which was a potential biomarker for diagnosing COPD. Overexpression of PACER in primary rat alveolar epithelial cells enhanced proliferative and migratory abilities. Compared with primary rat alveolar epithelial cells harvested from control rats, proliferative and migratory abilities were stronger in those harvested from COPD rats and induced with either DEX or not. Notably, DEX induction decreased PACER expression, and proliferative and migratory abilities in primary rat alveolar epithelial cells harvested from COPD rats. Overexpression of PP2A could partially abolish the promotive effects of PACER on proliferative and migratory abilities in DEX-induced primary rat alveolar epithelial cells harvested from COPD rats.

CONCLUSIONS

PACER drives the proliferative and migratory abilities of alveolar epithelial cells through activating PP2A. Dexmedetomidine is conducive to COPD treatment by downregulating PACER.

Prognostic value of late gadolinium enhancement in arrhythmogenic right ventricular cardiomyopathy: a meta-analysis

AIM

To assess systematically the prognostic value of cardiac magnetic resonance imaging (CMRI) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).

MATERIALS AND METHODS

The full text of studies of the clinical efficacy of late gadolinium enhancement (LGE) in ARVC was retrieved in multiple databases. Stata 14 was adopted for meta-analysis and bias analysis. Heterogeneity was assessed with the I² statistic.

RESULTS

After exclusions, 561 patients were included in five studies, and the eligibility criteria were met. The meta-analysis suggested that there was a significant difference between LGE positive and negative patients with ARVC in all-cause mortality (relative risk [RR] = 4.78, 95% confidence interval [CI] = 1.41, 16.23, p=0.012; p for heterogeneity = 0.692, I² = 0%); major adverse cardiovascular events (MACE) (RR=2.48, 95% CI = 1.24, 4.96, p=0.010; p for heterogeneity = 0.596, I² = 0%); ventricular tachycardia (RR=3.13, 95% CI = 1.69, 5.78, p<0.001; p for heterogeneity = 0.825, I² = 0%); implanted cardiac defibrillators (RR=3.15, 95% CI = 1.69, 5.87], p<0.001; p for heterogeneity = 0.353, I² = 9.4%).

CONCLUSION

LGE in ARVC patients is a predictor of all-cause mortality and MACE.

Differences in hypertension and prehypertension among people living with and without HIV in China: role of HIV infection and antiretroviral therapy

OBJECTIVES

Hypertension is a growing health concern in people living with HIV (PLWH). However, association between HIV infection and hypertension is equivocal.

METHODS

In all, 1472 PLWH and 2944 HIV-negative individuals frequency-matched by age and sex were derived from the baseline survey of Comparative HIV and Aging Research in Taizhou (CHART), China. Prehypertension was defined as systolic blood pressure (BP) of 120-139 mmHg and/or diastolic blood pressure of 80-89 mmHg.

RESULTS

Despite the fact that prevalence of hypertension was overall lower among PLWH than among HIV-negative people (21.1% vs. 29.1%, P < 0.001), it was similar at ages 18-29 (7.6% vs. 8.5%) and 30-44 years (17.1% vs. 18.5%) but significantly lower in PLWH at ages 45-59 (26.1% vs. 40.7%) and 60-75 years (37.1% vs. 57.3%). Prehypertension prevalence was consistently higher in PLWH across all age groups. In the model adjusting for traditional risk factors, HIV infection was associated with hypertension (adjusted odds ratio [aOR] = 1.27, 95% confidence interval: 1.04-1.55) and prehypertension (aOR = 1.77, 95% CI: 1.51-2.08), and attenuated after additional adjustment for abdominal obesity. Age-stratified analysis showed that these associations of HIV with hypertension were observed at ages 18-29 and 30-44 years and associations with prehypertension were observed at ages 18-29, 30-44 and 45-59 years only. Years since HIV diagnosis and stavudine use were the HIV-specific factors independently associated with hypertension or/and prehypertension.

CONCLUSIONS

HIV infection is independently associated with prehypertension and hypertension especially at younger ages, and this risk may increase as treatment becomes prolonged. Our findings reinforce the urgent necessity for active BP screening and control strategies be adopted for PLWH in China.

FHOD3 promotes carcinogenesis by regulating RhoA/ROCK1/LIMK1 signaling pathway in medulloblastoma

PURPOSE

Medulloblastoma (MB) is a malignant brain disease in young children. The overall survival of MB patients is disappointing due to absence of effective therapeutics and this could be attributed to the lack of molecular mechanism underlying MB. FHOD3 was an important gene during cardio-genesis and was reported to promote cell migration in cancer. However, its role in MB is not clear to date.

METHODS

RT-qPCR and IHC analysis were used to determine expression of FHOD3. Survival curve was drawn by K-M analysis. FHOD3 was knocked down by RNAi technology. The effects of FHOD3 on medulloblastoma cells were determined by CCK-8 assay, colony formation assay, transwell assay and FACs analysis.

RESULTS

FHOD3 expression increased by 1.5 fold in tumor tissues compared to the control and IHC analysis further confirmed strong expression of FHOD3 in medulloblastoma tissues. Then higher FHOD3 expression was associated with shorter survival time in MB patients (13.0 months versus 43.8 months). In medulloblastoma cells such as Daoy and D283med, FHOD3 also displayed abundant expression. When FHOD3 was knocked down, the ability of cell proliferation and colony formation was reduced over greatly. The capability of cell migration and invasion was also inhibited significantly. However, cell apoptotic rate increased significantly reversely. Mechanistically, the phosphorylation level of RhoA, ROCK1, and LIMK1 was decreased when FHOD3 was knocked down but increased reversely when FHOD3 was over-expressed in Daoy cells.

CONCLUSIONS

FHOD3 was associated with overall survival time in medulloblastoma patients and was essential to cell proliferation, growth and survival in medulloblastoma and might regulates activation of RhoA/ROCK1/LIMK1 signaling pathway.

MiR-30 suppresses lung cancer cell 95D epithelial mesenchymal transition and invasion through targeted regulating Snail

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "MiR-30 suppresses lung cancer cell 95D epithelial mesenchymal transition and invasion through targeted regulating Snail, by M.-J. Fan, Y.-H. Zhong, W. Shen, K.-F. Yuan, G.-H. Zhao, Y. Zhang, S.-K. Wang, published in Eur Rev Med Pharmacol Sci 2017; 21 (11): 2642-2649-PMID: 28678320" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/12883.

SINAT E3 ligases regulate the stability of the ESCRT component FREE1 in response to iron deficiency in plants

The endosomal sorting complex required for transport (ESCRT) machinery is an ancient, evolutionarily conserved membrane remodeling complex that is essential for multivesicular body (MVB) biogenesis in eukaryotes. FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1 (FREE1), which was previously identified as a plant-specific ESCRT component, modulates MVB-mediated endosomal sorting and autophagic degradation. Although the basic cellular functions of FREE1 as an ESCRT component have been described, the regulators that control FREE1 turnover remain unknown. Here, we analyzed how FREE1 homeostasis is mediated by the RING-finger E3 ubiquitin ligases, SINA of Arabidopsis thaliana (SINATs), in response to iron deficiency. Under iron-deficient growth conditions, SINAT1-4 were induced and ubiquitinated FREE1, thereby promoting its degradation and relieving the repressive effect of FREE1 on iron absorption. By contrast, SINAT5, another SINAT member that lacks ubiquitin ligase activity due to the absence of the RING domain, functions as a protector protein which stabilizes FREE1. Collectively, our findings uncover a hitherto unknown mechanism of homeostatic regulation of FREE1, and demonstrate a unique regulatory SINAT-FREE1 module that subtly regulates plant response to iron deficiency stress.

MicroRNA-101-5p inhibits the growth and metastasis of cervical cancer cell by inhibiting CXCL6

OBJECTIVE

The objective of this study is to explore the biological roles of microRNA-101-5p (miR-101-5p) in the growth and metastasis of cervical cancer.

PATIENTS AND METHODS

The levels of miR-101-5p and chemokine (C-X-C motif) ligand 6 (CXCL6) in cervical cancer tissues and cells were detected using the quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay. The proliferation, colony formation, migration, and invasion assays were conducted using miR-101-5p transfected cervical cancer cell. The expression of CXCL6 was measured by the immunoblotting assay. Xenograft model was constructed to reveal the precise roles of miR-101-5p in the growth of cervical cancer cell in vivo.

RESULTS

MiR-101-5p was down-regulated in cervical cancer tissues when compared to the normal controls. The levels of miR-101-5p were higher in cervical cancer cells (SiHa, Caski, C-4-I, C-33 A) than that in the human cervical surface epithelial cell line, HcerEpic. Over-regulation of miR-101-5p inhibited the aggressiveness phenotypes of a cervical cancer cell in vitro. Furthermore, over-regulation of miR-101-5p reduced the tumor growth of cervical cancer cell in vivo. CXCL6 was the target protein of miR-101-5p in cervical cancer as demonstrated by luciferase reporter assay. The mRNA level of CXCL6 was negatively associated with the miR-101-5p level in cervical cancer tissue. Finally, the rescue experiments suggested that the inhibitory role of miR-101-5p was mediated by regulating the expression of CXCL6 in cervical cancer.

CONCLUSIONS

These findings indicated that the over-regulation of miR-101-5p suppressed the progression of cervical cancer by targeting CXCL6 and might function as a potential therapeutic target for cervical cancer.

Functional Analysis of Plant FYVE Domain Proteins in Endosomal Trafficking

The FYVE domain is a double zinc finger-like domain that predominantly binds phosphatidylinositol 3-phosphate. The FYVE domain is usually found in proteins primarily involved in regulating various aspects of endomembrane homeostasis, including endosome tethering, endocytic recycling, membrane protein sorting, and autophagosome maturation. Whereas FYVE domain proteins have been extensively studied in mammals and yeast, only a few FYVE domain proteins have been identified and characterized in plants. Here, by using as an example FREE1 (FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1), a protein previously identified by us as a critical factor for endosomal trafficking, we describe methods to determine its lipid binding properties and endosomal localization. In addition, we also demonstrate a method to quickly test whether an FYVE domain protein is involved in endosomal sorting in plant cells.

HIV infection and electrocardiogram abnormalities: baseline assessment from the CHART cohort

OBJECTIVES

To investigate the prevalence of various electrocardiogram (ECG) abnormalities among HIV-positive and HIV-negative individuals.

METHODS

This cross-sectional evaluation included 1412 HIV-positive and 2824 HIV-negative participants aged 18 to 75 years and frequency matched by age and sex, derived from the baseline survey of Comparative HIV and Aging Research in Taizhou (CHART), China, between February and December 2017.

RESULTS

HIV-positive individuals had higher prevalence of sinus tachycardia (5.6% (79/1412) vs. 1.3% (36/2824), p < 0.001) and ST/T wave abnormalities (14.9% (211/1412) vs. 9.4% (264/1412), p < 0.001) but lower prevalence of sinus bradycardia (4.8% (68/1412) vs. 7.5% (211/2824), p 0.001); such associations remained statistically significant after adjusting for traditional risk factors (respectively, adjusted odds ratio (aOR) 4.68, 95% confidence interval (CI) 3.06-7.17; aOR 1.89, 95% CI 1.54-2.34; aOR 0.60, 95% CI 0.44-0.80). In adjusted models, being in higher carotid intima-media thickness categories was significantly associated with ST/T abnormalities in HIV-positive individuals only (0.78-1.00 mm: aOR 1.46, 95% CI 1.01-2.12; >1.00 mm: aOR 2.18, 95% CI 1.39-3.42), whereas being in higher blood pressure categories was significantly associated with both sinus tachycardia (prehypertension: aOR 5.61, 95% CI 1.76-17.91; hypertension: aOR 12.62, 95% CI 3.60-44.27) and ST/T abnormalities (hypertension: aOR 2.04, 95% CI 1.41-2.95) in HIV-negative individuals only. Longer duration of known HIV infection was the only HIV-specific factor of ST/T abnormalities (aOR 1.61, 95% CI 1.17-2.22), with none for sinus tachycardia.

CONCLUSIONS

HIV infection is independently associated with sinus tachycardia and ST/T abnormalities. Further research is needed to investigate specific mechanisms by which HIV infection leads to ECG abnormalities and to evaluate whether inclusion of ECG parameters improves cardiovascular disease prediction. Integrating ECG screening into routine HIV care is recommended in China.

HY5-HDA9 Module Transcriptionally Regulates Plant Autophagy in Response to Light-to-Dark Conversion and Nitrogen Starvation

Light is arguably one of the most important environmental factors that determines virtually all aspects of plant growth and development, but the molecular link between light signaling and the autophagy pathway has not been elucidated in plants. In this study, we demonstrate that autophagy is activated during light-to-dark conversion though transcriptional upregulation of autophagy-related genes (ATGs). We showed that depletion of the ELONGATED HYPOCOTYL 5 (HY5), a key component of light signaling, leads to enhanced autophagy activity and resistance to extended darkness and nitrogen starvation treatments, contributing to higher expression of ATGs. HY5 interacts with and recruits HISTONE DEACETYLASE 9 (HDA9) to ATG5 and ATG8e loci to repress their expression by deacetylation of the Lys9 and Lys27 of histone 3. Furthermore, we found that both darkness and nitrogen depletion induce the degradation of HY5 via 26S proteasome and the concomitant disassociation of HDA9 from ATG5 and ATG8e loci, leading to their depression and thereby activated autophagy. Genetic analysis further confirmed that HY5 and HDA9 act synergistically and function upstream of the autophagy pathway. Collectively, our study unveils a previously unknown transcriptional and epigenetic network that regulates autophagy in response to light-to-dark conversion and nitrogen starvation in plants.

Altered hippocampal functional connectivity in primary Sjögren syndrome: a resting-state fMRI study

Structural and metabolic abnormalities in the hippocampus have been associated with the pathophysiological mechanism of central nervous system involvement in primary Sjögren syndrome (pSS). Nevertheless, how hippocampal function is altered in pSS remains unknown. The purpose of our study is to investigate the alterations in hippocampal functional connectivity (FC) in pSS by using resting-state functional magnetic resonance imaging (rs-fMRI). Thirty-eight patients with pSS and 38 age- and education level-matched healthy controls (HCs) underwent magnetic resonance imaging examination. Prior to each MRI examination, neuropsychological tests were performed. Left and right hippocampal FCs were analyzed by using seed-based whole-brain correlation and compared between pSS and HCs. Spearman correlation analysis was performed between the z-value of hippocampal FC in brain regions with significant difference between the two groups and neuropsychological tests/clinical data in pSS. Compared with the controls, the patients with pSS showed decreased hippocampal FC between the left hippocampus and the right inferior occipital gray (IOG)/inferior temporal gray (ITG), as well as between the right hippocampus and right IOG/middle occipital gray (MOG), left MOG, and left middle temporal gray. In addition, increased hippocampal FCs were detected between the left hippocampus and left putamen, as well as between the right hippocampus and right cerebellum posterior lobe. Moreover, the visual reproduction score positively correlated with the FC between right hippocampus and right IOG/MOG. The white matter hyperintensity score negatively correlated with the FC between left hippocampus and right IOG/ITG. In conclusion, patients with pSS suffered decreased hippocampal FC mainly sited in the occipital and temporal cortex with right hippocampal laterality. Altered hippocampal FC might be a potential biomarker in detecting brain function changes and guiding neuroprotection in pSS.

Immediate early response protein 2 promotes the migration and invasion of hepatocellular carcinoma cells via regulating the activity of Rho GTPases

Human immediate early response 2 (IER2) has been implicated in tumor cell motility and metastasis; however, the underlying mechanisms in hepatocellular carcinoma (HCC) metastasis remain to be clarified. In this study, we demonstrate that dysregulation of IER2 was shown in HCC clinical samples, and IER2 expression resulted in the promotion of cell migration and invasion in vitro, and HCC tumor growth and pulmonary metastasis in vivo. Moreover, we showed that IER2 expression altered assembly of the actin cytoskeleton rearrangement. Furthermore, MAPK and PI3K/Akt signaling pathways induced by IER2 were confirmed to be probably involved in regulating the activity of Rho GTPases, such as RhoA, Rac1 and Cdc42. Collectively, our results indicated a significant role of IER2 in the HCC cell motility and metastasis through MAPK and PI3K/Akt signaling pathways to regulate the activity of Rho GTPases, thereby modulating actin cytoskeleton rearrangement, unveiling a novel mechanism of cell motility regulation induced by IER2.

A Combinatorial Reporter Set to Visualize the Membrane Contact Sites Between Endoplasmic Reticulum and Other Organelles in Plant Cell

The membrane contact sites (MCSs) enable interorganelle communication by associating organelles at distances of tens of nanometers over extended membrane surfaces and serve to maintain cellular homeostasis through efficient exchange of metabolites, lipid, and calcium between organelles, organelle fission, and movement. Most MCSs and a growing number of tethering proteins especially those involved in mediating the junctions between endoplasmic reticulum (ER) and other organelles have been extensively characterized in mammal and yeast. However, the studies of plant MCSs are still at stages of infancy, at least one reason might be due to the lack of bona fide markers for visualizing these membrane junctions in plant cells. In this study, a series of genetically encoded reporters using split super-folder GFP protein were designed to detect the possible MCSs between ER and three other cellular compartments including chloroplast, mitochondria and plasma membrane (PM) in plant cell. By expressing these genetically encoded reporter in Arabidopsis protoplasts as well as Nicotiana benthamiana leaf, we could intuitively observe the punctate signal surrounding chloroplast upon expression of ER-chloroplast MCS reporter, punctate signal of ER-mitochondria MCS reporter and punctate signal close to the PM upon expression of ER-PM MCS reporter. We also showed that the ER-chloroplast MCSs were dynamic structures that undergo active remodeling with concomitant occurrence of chloroplast dysfunction inside plant cells. This study demonstrates that ER associates with various organelles in close proximity in plant cells and provides tools that might be applicable for visualizing MCSs in plants.