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TREX1 is an exonuclease that degrades extranuclear DNA species in mammalian cells. Herein, we show a novel mechanism by which TREX1 interacts with the BiP/GRP78 and TREX1 deficiency triggers ER stress through the accumulation of single-stranded DNA and activates unfolded protein response (UPR) signaling via the disruption of the TREX1-BiP/GRP78 interaction. In TREX1 knockdown cells, the activation of ER stress signaling disrupted ER Ca2+ homeostasis via the ERO1α-IP3R1-CaMKII pathway, leading to neuronal cell death. Moreover, TREX1 knockdown dysregulated the Golgi-microtubule network through Golgi fragmentation and decreased Ac-α-tubulin levels, contributing to neuronal injury. These alterations were also observed in neuronal cells harboring a TREX1 mutation (V91M) that has been identified in hereditary spastic paraplegia (HSP) patients in Korea. Notably, this mutation leads to defects in the TREX1-BiP/GRP78 interaction and mislocalization of TREX1 from the ER and possible disruption of the Golgi-microtubule network. In summary, the current study reveals TREX1 as a novel regulator of the BiP/GRP78 interaction and shows that TREX1 deficiency promotes ER stress-mediated neuronal cell death, which indicates that TREX1 may hold promise as a therapeutic target for neurodegenerative diseases such as HSP. more...

Supplementary Methods, Figures Legends 1-5 from Human ZNF312b Promotes the Progression of Gastric Cancer by Transcriptional Activation of the K-ras Gene

Supplementary Figure 3 from Human ZNF312b Promotes the Progression of Gastric Cancer by Transcriptional Activation of the K-ras Gene

Supplementary Figure 2 from Human ZNF312b Promotes the Progression of Gastric Cancer by Transcriptional Activation of the K-ras Gene

Gastric cancer ranks second among the most common causes of cancer deaths worldwide. Recent studies reported target molecules that are candidates for new therapeutic interventions; however, their molecular mechanism has not been clearly defined. In this study, we found that ZNF312b plays a role in tumor progression and metastasis in gastric cancer via transcriptional activation of the K-ras oncogene. ZNF312b seems to be specifically overexpressed in gastric cancer tissues and cell lines. The overexpression of ZNF312b induces cancer-like phenotypes, including accelerated proliferation and increased tumor masses in nude mice, which are completely reversed by its knockdown in gastric cancer cell lines, implying direct involvement in gastric tumor progression. From analyses using deletion mutants of ZNF312b and K-ras promoter-driven luciferase reporters, we found that it translocates into the nucleus via the proline-rich domain of its COOH terminus to activate transcription of the K-ras gene, resulting in an enhancement of the extracellular signal-regulated kinase signaling pathway that governs cell proliferation. Taken together, these results suggest that ZNF312b contributes to the promotion of gastric cancer by triggering K-ras oncogene expression. The current study is the first to report that ZNF312b, a novel transcription factor, was associated with tumorigenicity of gastric cancer. This might be a valuable target that could provide new insight into the development of new therapeutic modalities for patients with gastric cancer. [Cancer Res 2009;69(7):3131–9] more...

Supplementary Figure 1 from Human ZNF312b Promotes the Progression of Gastric Cancer by Transcriptional Activation of the K-ras Gene

Supplementary Figure 4 from Human ZNF312b Promotes the Progression of Gastric Cancer by Transcriptional Activation of the K-ras Gene

Supplementary Figure 5 from Human ZNF312b Promotes the Progression of Gastric Cancer by Transcriptional Activation of the K-ras Gene

Supplementary Table 1 from Human ZNF312b Promotes the Progression of Gastric Cancer by Transcriptional Activation of the K-ras Gene

ObjectiveRecently, we demonstrated cholesterol accelerating colorectal cancer (CRC) progression via squalene epoxidase (SQLE) reduction, activating the β-catenin oncogenic pathway while downregulating the p53 pathway, mediated by the inhibition of GSK3β activity (GSK3βpS9). However, the interrelationship between cholesterol increase and CRC progression with aging has never been determined.DesignWe utilized case data from public databases and human specimens to assess the relationship between cholesterol accumulation and CRC progression with aging. Digital image analysis-machine learning with multiplex fluorescence-immunohistochemistry evaluated the effects of SQLE, p53WT, p53MT, and GSK3βpS9(hereafter candidates) on the survival of CRC patients. Also, the prognostic and diagnostic abilities were assessed by a time-dependent receiver operating characteristic (timeROC) and a ROC curve with and without the discriminant score for the candidates as a single or whole, respectively.ResultsWe found an accumulation of cholesterol and cholesteryl ester in tissues with aging, which led to the acceleration of CRC progression through substantial decreases of SQLE, p53WT, p53MTexpressions and inhibition of GSK3β activity in advanced CRCs. Retrospective studies demonstrated that SQLE significantly impacted the shortened progression-free survival of the population with progressive pathological severity and high CRC risk beyond the age of 50. Clinical assays further showed the excellent prognostic and diagnostic abilities of SQLE and GSK3βpS9but also the substantial diagnostic potential of the combined candidate for the aged high-risk CRC population.ConclusionWe provide new insights into the relationship between cholesterol increase and CRC progression with aging and identify valuable biomarkers for aged populations with high-risk CRC. more...

Intellectual disability (ID) is a neurodevelopmental disorder defined by below-average intelligence (intelligence quotient of

Introduction: Despite increasing numbers of homeless people, less attention has been paid to their mental health, particularly associated with crime victimization. This study sought to examine the ... more...

Background Hereditary cerebellar ataxias exhibit heterogeneous phenotypes and genotypes. To date, advancement of next-generation sequencing technologies have identified many causative genes for ataxia in various population. In this study, whole-exome sequencing (WES) was utilized to explore the genetic cause of ataxia among Korean patients who remained undiagnosed following routine investigation. Methods Patients with ataxia were enrolled in this study. We excluded patients with acquired, degenerative, and trinucleotide repeat ataxias, such as spinocerebellar ataxia 1 (SCA1), SCA2, SCA3, SCA6, SCA7, SCA8, SCA17, Dentatorubral-pallidoluysian atrophy, and Friedreich ataxia. WES was performed. After basic filtering based on population databases, we then performed primary filtering to screen for known ataxia-associated genes, followed by expanded filtering customized for individual patients. Results We enrolled 77 ataxia patients from 68 families. Eighteen families had pathogenic or likely pathogenic variants in 14 different genes, including NEU1, APTX, SPG7, HTRA1, POLG2, SYNE1, CACNA1G, CACNA1A, ITPR1, AHI1, SPG11, ANO10, ATM, and C5orf42, resulting in a diagnostic yield of 26.5%. Hereditary spastic paraplegia was the most common diagnosis. Adult-onset ataxias and those without family history were frequently encountered. Variants of unknown significance were found in 14 (20.6%) families, some of which were highly probable from the clinical perspective. Conclusion Using WES, we explored the molecular etiology of ataxia in patients whom were not diagnosed through routine clinical investigation. This study revealed unexpected rare disorders as well as the known ataxia-associated genes in a Korean population. more...

Aim: Lennox-Gastaut syndrome (LGS) is a severe type of childhood-onset epilepsy with multiple types of seizures, specific discharges on electroencephalography, and intellectual disability. However, LGS-related genes are largely unknown. To identify causative genes related to LGS, we collected and analyzed data from a three-generation Korean family in which one member had LGS and two had intellectual disability. Methods: Genomic DNAs were extracted from blood samples of all participants and used in whole-exome sequencing (WES). Genetic variants were detected by the Genome Analysis Toolkit and confirmed by Sanger sequencing. Variant pathogenicity was evaluated by prediction programs and the American College of Medical Genetics criteria. The LGS patient had generalized slow spike-and-wave discharges, multiple types of seizures, and developmental delay. Results: Analyses of the WES data from the family revealed a novel variant (c.1048G>A, p.Ala350Thr) in the IQ motif and Sec7 domain 2 (IQSEC2). This variant is within a highly evolutionarily conserved IQ-like motif, indicating a decrease in the calmodulin-binding capacity or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid transmission. The hemizygous variant in the male with LGS was a maternally inherited X-linked variant from the heterozygous maternal grandmother and mother, both of whom had intellectual disability. Conclusion: These findings indicate that the variant of IQSEC2 triggered both LGS and intellectual disability dependent on sex in this family. We report a novel X-linked inherited IQSEC2 variant for LGS and intellectual disability, which enhances the spectrum of variants in the IQ-like motif of IQSEC2. more...

Studies have reported dysregulation of TIPRL, LC3 and CD133 in liver cancer tissues. However, their respective relationships to liver cancer and roles as biomarkers for prognosis and diagnosis of liver cancer have never been studied. Here we report that the level of TIPRL is significantly correlated with levels of LC3 (Spearman r = 0.9) and CD133 (r = 0.7) in liver cancer tissues. We observed significant upregulations of TIPRL, LC3 and CD133 in hepatocellular carcinomas (HCCs) compared with adjacent normal tissues. Importantly, TIPRL, tested among additional variables, showed a significant impact on the prognosis of HCC patients. TIPRL knockdown significantly reduced expressions of LC3, CD133, stemness-related genes, as well as viability and stemness of liver cancer cell-lines, which were promoted by ectopic TIPRL expression. Either alone or as a combination, TIPRL, LC3 and CD133 showed significant values of area under the curve (AUC) and sensitivity/specificity in early liver cancer tissues. Furthermore, the statistical association and the diagnostic efficacies of TIPRL, LC3 and CD133 in HCC tissues were confirmed in a different IHC cohort. This data demonstrates that the complex involvement of TIPRL/LC3/CD133 in liver cancer aggressiveness can together or individually serve as potential biomarkers for the early detection of liver cancer. more...

The aim of this study is to examine formal and informal care use among community-dwelling older Korean adults. Older adults aged between 65 and 85 ( N = 516) in mid-size city, selected using the probability proportional sampling method, were interviewed in person. One third reported having at least one caregiver. Compared to respondents who did not use any informal/formal care, those who used any formal or informal care were older and were more likely to be prefrail or frail and experienced at least one hospitalization or emergency department use in the past year. Living alone or being experienced with any hospitalization was associated with formal care use. Most care recipients received informal care from families, specifically spouses. Among participants who received no formal/informal care, 19% of them expected to receive formal care support in the future. Substantial support programs for informal caregivers are needed to address the increase in demand and expectation for long-term care. more...

Spastin is a microtubule-severing enzyme encoded by SPAST, which is broadly expressed in various cell types originated from multiple organs. Even though SPAST is well known as a regulator of the axon growth and arborization in neurons and a genetic factor of hereditary spastic paraplegia, it also takes part in a wide range of other cellular functions including the regulation of cell division and proliferation. In this study, we investigated a novel biological role of spastin in developing brain using Spast deficient mouse embryonic neural stem cells (NSCs) and perinatal mouse brain. We found that the expression of spastin begins at early embryonic stages in mouse brain. Using Spast shRNA treated NSCs and mouse brain, we showed that Spast deficiency leads to decrease of NSC proliferation and neuronal lineage differentiation. Finally, we found that spastin controls NSC proliferation by regulating microtubule dynamics in primary cilia. Collectively, these data demonstrate that spastin controls brain development by the regulation of NSC functions at early developmental stages. more...

As global plastic production continues to grow, microplastics released from a massive quantity of plastic wastes have become a critical environmental concern. These microplastic particles are found in a wide range of living organisms in a diverse array of ecosystems. In this study, we investigated the biological effects of polystyrene nanoplastics (PSNPs) on development of the central nervous system using cultured neural stem cells (NSCs) and mice exposed to PSNPs during developmental stages. Our study demonstrates that maternal administration of PSNPs during gestation and lactating periods altered the functioning of NSCs, neural cell compositions, and brain histology in progeny. Similarly, our in vitro study also shows PSNP-induced molecular and functional defects in NSCs. Finally, we show that the abnormal brain development caused by exposure to high concentrations of PSNPs results in neurophysiological and cognitive deficits in a gender-specific manner. Our data demonstrate the possibility that exposure to high amounts of PSNPs may increase the risk of neurodevelopmental defects. more...

Simple Summary We recently reported that the human TOR signaling regulator (hereafter TIPRL) contributes to the drug-resistance of hepatocellular carcinomas (HCCs) and the involvement of TIPRL/LC3/CD133 in liver cancer aggressiveness. This study aims to determine prognostic and diagnostic efficacies of TIPRL/LC3/CD133/CD44 for early liver cancer. We observed the significant upregulation of TIPRL and LC3 in HCCs and adult hepatocyte-derived liver disease while observing downregulation in intrahepatic carcinomas (iCCA). The TIPRL level has been shown to be the clearest indicator of liver cancer patients’ survivability as a sole covariate. This indication supports that TIPRL contributed to liver cancer cell proliferation and survival via stemness and self-renewal induction. TIPRL/LC3/CD133 have exhibited crucial efficiency in diagnostic patients with grade 1 iCCA, and TIPRL/LC3/CD133/CD44 showed prognosticating grade-1 HCCs and iCCA, either as an alone or in conjunction. Overall, this study reports that TIPRL/LC3/CD133/CD44 could, either individually or in conjunction, serve as potential biomarkers for early liver cancer. Abstract Recently, we reported the involvement of TIPRL/LC3/CD133 in liver cancer aggressiveness. This study assessed the human TOR signaling regulator (TIPRL)/microtubule-associated light chain 3 (LC3)/prominin-1 (CD133)/cluster of differentiation 44 (CD44) as potential diagnostic and prognostic biomarkers for early liver cancer. For the assessment, we stained tissues of human liver disease/cancer with antibodies against TIPRL/LC3/CD133/CD44/CD46, followed by confocal observation. The roles of TIPRL/LC3/CD133/CD44/CD46 in liver normal and cancer cell lines were determined by in vitro studies. We analyzed the prognostic and diagnostic potentials of TIPRL/LC3/CD133/CD44/CD46 using the receiver-operating characteristic curve, a Kaplan–Meier and uni-/multi-Cox analyses. TIPRL and LC3 were upregulated in tissues of HCCs and adult hepatocytes-derived liver diseases while downregulated in iCCA. Intriguingly, TIPRL levels were found to be critically associated with liver cancer patients’ survivability, and TIPRL is the key player in liver cancer cell proliferation and viability via stemness and self-renewal induction. Furthermore, we demonstrate that TIPRL/LC3/CD133 have shown prominent efficiency for diagnosing patients with grade 1 iCCA. TIPRL/LC3/CD133/CD44 have also provided excellent potential for prognosticating patients with grade 1 iCCA and grade 1 HCCs, together with demonstrating that TIPRL/LC3/CD133/CD44 are, either individually or in conjunction, potential biomarkers for early liver cancer. more...

Hereditary Spastic Paraplegias (HSP) are a group of rare inherited neurological disorders characterized by progressive loss of corticospinal motor-tract function. Numerous patients with HSP remain undiagnosed despite screening for known genetic causes of HSP. Therefore, identification of novel genetic variations related to HSP is needed. In this study, we identified 88 genetic variants in 54 genes from whole-exome data of 82 clinically well-defined Korean HSP families. Fifty-six percent were known HSP genes, and 44% were composed of putative candidate HSP genes involved in the HSPome and originally reported neuron-related genes, not previously diagnosed in HSP patients. Their inheritance modes were 39, de novo; 33, autosomal dominant; and 10, autosomal recessive. Notably, ALDH18A1 showed the second highest frequency. Fourteen known HSP genes were firstly reported in Koreans, with some of their variants being predictive of HSP-causing protein malfunction. SPAST and REEP1 mutants with unknown function induced neurite abnormality. Further, 54 HSP-related genes were closely linked to the HSP progression-related network. Additionally, the genetic spectrum and variation of known HSP genes differed across ethnic groups. These results expand the genetic spectrum for HSP and may contribute to the accurate diagnosis and treatment for rare HSP. more...

TREX1 is an exonuclease that degrades extranuclear DNA species in mammalian cells. Herein, we show a novel mechanism by which TREX1 interacts with the BiP/GRP78 and TREX1 deficiency triggers ER stress through the accumulation of single-stranded DNA and activates unfolded protein response (UPR) signaling via the disruption of the TREX1-BiP/GRP78 interaction. In TREX1 knockdown cells, the activation of ER stress signaling disrupted ER Ca more...

Introduction Besides cerebellar ataxia, various other movement disorders, including dystonia, could manifest as main clinical symptoms in ataxia-telangiectasia (A–T). However, the clinical characteristics of dystonic A–T patients are not clearly elucidated. Methods To investigate the characteristics of dystonic A–T, we screened previous reports with A–T patients presenting dystonia as a main manifestation, and included 38 dystonic A–T patients from 16 previous studies and our 2 cases. We reviewed clinical and demographic data of dystonic A–T patients. Additionally, to figure out clinical meaning of cerebellar involvement in dystonic A–T, we divided them into two groups based on the presence of cerebellar involvement, and compared clinical features between two groups. Results In the patients with dystonic A–T, dystonia tended to appear during childhood or adolescence and became generalized over time. Choreoathetosis and myoclonus accompanied more frequently than the typical clinical features, including cerebellar ataxia or atrophy, telangiectasia, or oculomotor apraxia. Additionally, alpha-fetoprotein level was also elevated in the patients with dystonic A–T. When we compared dystonic A–T with and without cerebellar involvement, the former was related with more chance for telangiectasia and oculomotor apraxia, while the latter with that for choreoathetosis and malignancy. Conclusion Even without ataxia, telangiectasia, or oculomotor apraxia, A–T should be considered in undiagnosed dystonia, especially generalized dystonia which started from childhood or adolescence period, and alpha-fetoprotein level can be a useful screening tool. In addition, cerebellar involvement is important considering different phenotype in dystonic A–T patients with and without cerebellar sign. more...

Recent advances in next-generation sequencing technologies have uncovered the genetic backgrounds of various diseases. Type 1 sialidosis (OMIM#256550) is a rare autosomal recessive lysosomal storage disease caused by a mutation in the NEU1 (OMIM * 608272) gene. In this study, we aimed to review the previous reports of type 1 sialidosis and compare those with the first case of type 1 sialidosis in Korea. A 36-year-old woman presented with progressive ataxia, myoclonus, and seizure since the age of 12. Whole-exome sequencing revealed a pathogenic missense variant c.928G > A (p.D310N) and novel c.15_16del (p.P6Qfs*21) of the NEU1 gene as final causal candidate as compound heterozygotes. We reviewed the literature and selected the clinical reports of genetically confirmed type 1 sialidosis patients. A total of 45 patients in 17 reports were identified. Cherry-red spot, myoclonus, ataxia, and seizure were reported in 51.2%, 100.0%, 87.8%, and 73.7% of patients, respectively. Abnormalities of cognitive function, EEG, and brain MRI and visual symptoms were reported in 22.2%, 40.7%, 66.7%, and 70.2% of patients, respectively. Overall, our patient showed similar clinical features to previous type 1 sialidosis patients, but she did not complain of visual symptoms despite having cherry-red spots. We summarize the clinical features of type 1 sialidosis and report the first case of type 1 sialidosis with novel deletion variant in the NEU1 gene in the Korean population. Our study suggests the importance of ophthalmologic examinations in patients with myoclonus, ataxia, and seizure who do not complain of visual symptoms. more...

Introduction Recent advances in next generation sequencing technologies have uncovered the genetic background of various diseases. The mutations in the SYNE1 gene was previously identified as a potential cause of pure cerebellar ataxia. Although autosomal recessive ataxias are slightly more frequent than autosomal dominant forms worldwide, autosomal recessive forms are extremely rare in Korea. In this study, we aimed to identify SYNE1-associated ataxia by whole exome sequencing in a Korean sample, and to review the prevalence of SYNE1 in non-French-Canadians. Methods Patients with suspected cerebellar ataxia who visited movement disorders clinic from March 2014 to December 2017 were clinically screened. After excluding cases with acquired causes and common genetic causes in Korea, including spinocerebellar ataxia and dentatorubral-pallidoluysian atrophy, 63 undiagnosed subjects were screened for SYNE1 mutations by next generation sequencing methods. Results We identified four novel mutations (one splicing, one truncating, and two missense mutations) distributed throughout the SYNE1 gene in two patients. The phenotype was mainly pure cerebellar ataxia in both cases. However, axonal neuropathy, mild frontal dysfunction, and autonomic dysfunction were also revealed. The age of disease onset was relatively late and the disease course was only mildly progressive. Conclusion Our results indicate that SYNE1 mutations are not an uncommon cause of recessive ataxia with additional clinical features in the Korean population. The results of this study should alert neurologists to request SYNE1 testing to aid the diagnosis of undetermined adult-onset ataxia in Korean patients. more...

The spastin protein (SPAST) contains an ATPase with diverse cellular activities (AAA) domain and regulates microtubule dynamics. Missense mutations of the SPAST gene are frequently detected in patients with hereditary spastic paraplegias (HSPs) and represent the main reason of loss of SPAST function; however, the pathogenicity of mutant SPAST is heterogeneous. Here, SPAST variant with an I344K mutation (I344K-SPAST) was identified in a Korean family with autosomal dominant-type HSP. We investigated the role of the I344K-SPAST in HSP to provide a therapeutic mechanism. The I344K-SPAST mutation prolonged the half-life of the protein compared to wild-type SPAST (WT-SPAST) in cells by modulating post-translational modifications for proteasomal degradation. I344K-SPAST was localized in microtubule but defective in microtubule severing and ATPase activity compared to WT-SPAST in vitro and in cells. Mutant M87 isoform harboring the same mutation with I344K-M1 SPAST also increased protein stability and loss of MT severing activity, but the pathogenicity was not stronger than I344K-M1 SPAST in neurite outgrowth. Overexpression of I344K-SPAST resulted in microtubule accumulation following inhibited neurite growth in neuroblastoma, neural progenitor cells and mouse primary cortical neurons. Conversely, these pathogenic effects of I344K-SPAST were reduced by overexpression of WT-M1 SPAST in a dose dependent manner since WT-SPAST could interact with I344K-SPAST. Our data therefore provide proof-of-concept that gene transfer of WT-M1 SPAST may serve as a valid therapeutic option for HSPs. more...

Hereditary spastic paraplegia (HSP) progresses over time and is associated with locomotive dysfunction. Understanding the factors affecting disease severity and locomotive function is important in HSP. This study investigated the factors influencing disease severity and ambulation status of HSP.We consecutively enrolled 109 Korean patients (64 males, and 45 females)from 84 families with a clinical diagnosis of HSP. HSP was primarily diagnosed based on clinical criteria including clinical findings, family history, and supported by genetic studies. Epidemiological and clinical features of the patients were analyzed, and the Spastic Paraplegia Rating Scale (SPRS) score and ambulatory status were used to evaluate disease severity.Ninety-two (84.4%) patients had pure HSP, and 55 (50.4%) had a dominant family history. Thirty-one (28.4%) patients required a mobility aid for locomotion. A Kaplan-Meier analysis showed that HSP patients lost their independent gait ability after a median disease duration of 34 years. Those with an age at onset of ≤18 years had a longer median independent walking time. Pure HSP is characterized by predominant bilateral lower extremity weakness and spasticity, whereas complicated HSP presents more complex neurological findings such as ocular and bulbar symptoms, ataxia, and cognitive impairment. Complicated HSP was significantly correlated with the SPRS mobility score (β=3.70, 95% confidence interval=0.45-6.94). The age at onset and disease duration were significantly correlated with disease severity, and they were significant predictors of the use of a mobility aid (These findings suggest that a later age at onset and longer disease duration are significant factors affecting the disease severity and ambulatory function in patients with HSP. These findings can help clinicians to identify subjects at risk of locomotive impairment. more...

Current in vitro liver models provide three-dimensional (3-D) microenvironments in combination with tissue engineering technology and can perform more accurate in vivo mimicry than two-dimensional models. However, a human cell-based, functionally mature liver model is still desired, which would provide an alternative to animal experiments and resolve low-prediction issues on species differences. Here, we prepared hybrid hydrogels of varying elasticity and compared them with a normal liver, to develop a more mature liver model that preserves liver properties in vitro . We encapsulated HepaRG cells, either alone or with supporting cells, in a biodegradable hybrid hydrogel. The elastic modulus of the 3D liver dynamically changed during culture due to the combined effects of prolonged degradation of hydrogel and extracellular matrix formation provided by the supporting cells. As a result, when the elastic modulus of the 3D liver model converges close to that of the in vivo liver (≅ 2.3 to 5.9 kPa), both phenotypic and functional maturation of the 3D liver were realized, while hepatic gene expression, albumin secretion, cytochrome p450-3A4 activity, and drug metabolism were enhanced. Finally, the 3D liver model was expanded to applications with embryonic stem cell-derived hepatocytes and primary human hepatocytes, and it supported prolonged hepatocyte survival and functionality in long-term culture. Our model represents critical progress in developing a biomimetic liver system to simulate liver tissue remodeling, and provides a versatile platform in drug development and disease modeling, ranging from physiology to pathology. Statement of Significance We provide a functionally improved 3D liver model that recapitulates in vivo liver stiffness. We have experimentally addressed the issues of orchestrated effects of mechanical compliance, controlled matrix formation by stromal cells in conjunction with hepatic differentiation, and functional maturation of hepatocytes in a dynamic 3D microenvironment. Our model represents critical progress in developing a biomimetic liver system to simulate liver tissue remodeling, and provides a versatile platform in drug development and disease modeling, ranging from physiology to pathology. Additionally, recent advances in the stem-cell technologies have made the development of 3D organoid possible, and thus, our study also provides further contribution to the development of physiologically relevant stem-cell-based 3D tissues that provide an elasticity-based predefined biomimetic 3D microenvironment. more...

// Ji-Yong Yoon 1, * , Jeong-Ju Lee 1, * , Sujin Gu 2 , Myoung Eun Jung 2 , Hyun-Soo Cho 1, 4 , Jung Hwa Lim 3, 4 , Soo Young Jun 1, 4 , Jun-Ho Ahn 1 , Ju-Sik Min 1 , Min-Hyuk Choi 1, 4 , Su-Jin Jeon 1, 4 , Yong-Jae Lee 1 , Areum Go 2, 5 , Yun-Jeong Heo 2 , Cho-Rok Jung 3, 4 , Gildon Choi 2, 5 , Kwangho Lee 2, 5 , Moon-Kook Jeon 2 and Nam-Soon Kim 1, 4 1 Genome Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-333, Republic of Korea 2 Bio and Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, 34114, Republic of Korea 3 Gene Therapy Research Unit, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-333, Republic of Korea 4 Department of Functional Genomics, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea 5 Medicinal Chemistry and Pharmacology, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea * Co-first authors Correspondence to: Nam-Soon Kim, email: nskim37@kribb.re.kr Moon-Kook Jeon, email: moteta@krict.re.kr Keywords: TIPRL, apoptosis, HCC, TRAIL sensitizer Received: January 25, 2017 Accepted: September 29, 2017 Published: November 03, 2017 ABSTRACT Hepatocellular carcinoma (HCC) is one of the most malignant tumors. Although various treatments, such as surgery and chemotherapy, have been developed, a novel alternative therapeutic approach for HCC therapy is urgently needed. Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) is a promising anti-cancer agent, but many cancer cells are resistant to TRAIL-induced apoptosis. To help overcome TRAIL resistance in HCC cancer cells, we have identified novel chemical compounds that act as TRAIL sensitizers. We first identified the hit compound, TRT-0002, from a chemical library of 6,000 compounds using a previously developed high-throughput enzyme-linked immunosorbent assay (ELISA) screening system, which was based on the interaction of mitogen-activated protein kinase kinase 7 (MKK7) and TOR signaling pathway regulator-like (TIPRL) proteins and a cell viability assay. To increase the efficacy of this TRAIL sensitizer, we synthesized 280 analogs of TRT-0002 and finally identified two lead compounds (TRT-0029 and TRT-0173). Co-treating cultured Huh7 cells with either TRT-0029 or TRT-0173 and TRAIL resulted in TRAIL-induced apoptosis due to the inhibition of the MKK7-TIPRL interaction and subsequent phosphorylation of MKK7 and c-Jun N-terminal kinase (JNK). In vivo , injection of these compounds and TRAIL into HCC xenograft tumors resulted in tumor regression. Taken together, our results suggest that the identified lead compounds serve as TRAIL sensitizers and represent a novel strategy to overcome TRAIL resistance in HCC. more...

Alternative cell sources, such as three-dimensional organoids and induced pluripotent stem cell-derived cells, might provide a potentially effective approach for both drug development applications and clinical transplantation. For example, the development of cell sources for liver cell-based therapy has been increasingly needed, and liver transplantation is performed for the treatment for patients with severe end-stage liver disease. Differentiated liver cells and three-dimensional (3D) organoids are expected to provide new cell sources for tissue models and revolutionary clinical therapies. However, conventional experimental methods confirming the expression levels of liver-specific lineage markers cannot provide complete information regarding the differentiation status or degree of similarity between liver and differentiated cell sources. Therefore, in this study, to overcome several issues associated with the assessment of differentiated liver cells and organoids, we developed a LiGEP (Liver-Specific Gene Expression Panel) algorithm that presents the degree of liver similarity as a “percentage”. We demonstrated that the percentage calculated using the LiGEP algorithm was correlated with the developmental stages of in vivo liver tissues in mice, suggesting that LiGEP can correctly predict developmental stages. Moreover, 3D cultured HepaRG cells and human pluripotent stem cell (hPSC)-derived hepatocyte-like cells (HLCs) showed liver similarity scores of 59.14% and 32%, respectively, although general liver-specific markers were detected. Therefore, our study describes the first quantitative and predictive model for differentiated samples, particularly liver-specific cells or organoids, and this model can be further expanded to various tissue-specific organoids. Our LiGEP can provide useful information and insights regarding the differentiation status of in vitro liver models. This article is protected by copyright. All rights reserved. more...

KIF1A is a brain-specific anterograde motor protein that transports cargoes towards the plus-ends of microtubules. Many variants of the KIF1A gene have been associated with neurodegenerative diseases and developmental delay. Homozygous mutations of KIF1A have been identified in a recessive subtype of hereditary spastic paraplegia (HSP), SPG30. In addition, KIF1A mutations have been found in pure HSP with autosomal dominant inheritance. Here we report the first case of familial complicated HSP with a KIF1A mutation transmitted in autosomal dominant inheritance. A heterozygous p.T258M mutation in KIF1A was found in a Korean family through targeted exome sequencing. They displayed phenotypes of mild intellectual disability with language delay, epilepsy, optic nerve atrophy, thinning of corpus callosum, periventricular white matter lesion, and microcephaly. A structural modeling revealed that the p.T258M mutation disrupted the binding of KIF1A motor domain to microtubules and its movement along microtubules. Assays of peripheral accumulation and proximal distribution of KIF1A motor indicated that the KIF1A motor domain with p.T258M mutation has reduced motor activity and exerts a dominant negative effect on wild-type KIF1A. These results suggest that the p.T258M mutation suppresses KIF1A motor activity and induces complicated HSP accompanying intellectual disability transmitted in autosomal dominant inheritance. more...

We fabricated a spheroid-forming unit (SFU) for efficient and economic production of cell spheroids. We optimized the protocol for generating large and homogenous liver cancer cell spheroids using Huh7 hepatocellular carcinoma (HCC) cells. The large Huh7 spheroids showed apoptotic and proliferative signals in the centre and at the surface, respectively. In particular, hypoxia-induced factor-1 alpha (HIF-1α) and ERK signal activation were detected in the cell spheroids. To diminish core necrosis and increase the oncogenic character, we co-cultured spheroids with 2% human umbilical vein endothelial cells (HUVECs). HUVECs promoted proliferation and gene expression of HCC-related genes and cancer stem cell markers in the Huh7 spheroidsby activating cytokine signalling, mimicking gene expression in liver cancer. HUVECs induced angiogenesis and vessel maturation in Huh7 spheroids in vivo by activating epithelial–mesenchymal transition and angiogenic pathways. The large Huh7 cell spheroids containing HUVECs survived at higher concentrations of anti-cancer drugs (doxorubicin and sorafenib) than did monolayer cells. Our large cell spheroid provides a useful in vitro HCC model to enable intuitive observation for anti-cancer drug testing. more...

The coiled-coil domain containing 50 (CCDC50) protein is a phosphotyrosine-dependent signalling protein stimulated by epidermal growth factor. It is highly expressed in neuronal cells in the central nervous system; however, the roles of CCDC50 in neuronal development are largely unknown. In this study, we showed that the depletion of CCDC50-V2 impeded the neuronal development process, including arbor formation, spine density development, and axonal outgrowth, in primary neurons. Mechanistic studies revealed that CCDC50-V2 positively regulated the nerve growth factor receptor, while it downregulated the epidermal growth factor receptor pathway. Importantly, JNK/c-Jun activation was found to be induced by the CCDC50-V2 overexpression, in which the interaction between CCDC50-V2 and JNK2 was also observed. Overall, the present study demonstrates a novel mechanism of CCDC50 function in neuronal development and provides new insight into the link between CCDC50 function and the aetiology of neurological disorders. more...

Autophagy, an intracellular system of degrading damaged organelles and misfolded proteins, is essential for cancer cell survival. Despite the progress made towards understanding the mechanism, identification of novel autophagy regulators presents a major obstacle in developing anticancer therapies. Here, we examine the association between the TOR signaling pathway regulator-like (TIPRL) protein and autophagy in malignant transformation of tumors. We show that TIPRL upregulation in non-small cell lung cancer (NSCLC) potentiated autophagy activity and enabled autophagic clearance of metabolic and cellular stress, conferring a survival advantage to cancer cells. Importantly, the interaction of TIPRL with eukaryotic initiation factor 2α (eIF2α) led to eIF2α phosphorylation and activation of the eIF2α-ATF4 pathway, thereby inducing autophagy. Conversely, TIPRL depletion increased apoptosis by reducing autophagic clearance, which was markedly enhanced in TIPRL-depleted A549 xenografts treated with 2-deoxy-D-glucose. Overall, the study indicated that TIPRL is a potential regulator of autophagy and an important drug target for lung cancer therapy. more...

// Jae-Hye Lee 1, 3, * , Hyun-Soo Cho 1, 3, * , Jeong-Ju Lee 1 , Soo Young Jun 1, 3 , Jun-Ho Ahn 1 , Ju-Sik Min 1 , Ji-Yong Yoon 1 , Min-Hyuk Choi 1, 3 , Su-Jin Jeon 1, 3 , Jung Hwa Lim 2 , Cho-Rok Jung 2 , Dae-Soo Kim 1, 3 , Hyun-Taek Kim 4 , Valentina M. Factor 5 , Yun-Han Lee 6 , Snorri S. Thorgeirsson 7 , Cheol-Hee Kim 4 , Nam-Soon Kim 1, 3 1 Genome Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333, Republic of Korea 2 Gene Therapy Research Unit, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333, Republic of Korea 3 Department of Functional Genomics, Korea University of Science and Technology, Daejeon 305-333, Republic of Korea 4 Department of Biology, Chungnam National University, Daejeon 305-764, Republic of Korea 5 Laboratory of Molecular Pharmacology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892-5068, USA 6 Department of Molecular Medicine, Keimyung University School of Medicine, Daegu 704-701, Republic of Korea 7 Laboratory of Human Carcinogenesis, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892-4255, USA * Both authors are shared co-first authorship Correspondence to: Nam-Soon Kim, email: nskim37@kribb.re.kr Keywords: liver cancer, metastasis, PGCP, Wnt/β-catenin Received: July 25, 2016 Accepted: October 14, 2016 Published: October 28, 2016 ABSTRACT Tumor metastasis is the leading cause of cancer death. In the metastatic process, EMT is a unique phenotypic change that plays an important role in cell invasion and changes in cell morphology. Despite the clinical significance, the mechanism underlying tumor metastasis is still poorly understood. Here we report a novel mechanism by which secreted plasma glutamate carboxypeptidase(PGCP) negatively involves Wnt/β-catenin signaling by DKK4 regulation in liver cancer metastasis. Pathway analysis of the RNA sequencing data showed that PGCP knockdown in liver cancer cell lines enriched the functions of cell migration, motility and mesenchymal cell differentiation. Depletion of PGCP promoted cell migration and invasion via activation of Wnt/β-catenin signaling pathway components such as phospho-LRP6 and β-catenin. Also, addition of DKK4 antagonized the Wnt/β-catenin signaling cascade in a thyroxine (T4)-dependent manner. In an in vivo study, metastatic nodules were observed in the lungs of the mice after injection of shPGCP stable cell lines. Our findings suggest that PGCP negatively associates with Wnt/β-catenin signaling during metastasis. Targeting this regulation may represent a novel and effective therapeutic option for liver cancer by preventing metastatic activity of primary tumor cells. more...