Targeting of lysosomal-bound protein mEAK-7 for cancer therapy.

mEAK-7 (mammalian EAK-7 or MTOR-associated protein, eak-7 homolog), is an evolutionarily conserved lysosomal membrane protein that is highly expressed in several cancer cells. Multiple recent studies have identified mEAK-7 as a positive activator of mTOR (mammalian/mechanistic target of rapamycin) signaling via an alternative mTOR complex, implying that mEAK-7 plays an important role in the promotion of cancer proliferation and migration. In addition, structural analyses investigating interactions between mEAK-7 and V-ATPase, a protein complex responsible for regulating pH homeostasis in cellular compartments, have suggested that mEAK-7 may contribute to V-ATPase-mediated mTORC1 activation. The C-terminal α-helix of mEAK-7 binds to the D and B subunits of the V-ATPase, creating a pincer-like grip around its B subunit. This binding undergoes partial disruption during ATP hydrolysis, potentially enabling other proteins such as mTOR to bind to the α-helix of mEAK-7. mEAK-7 also promotes chemoresistance and radiation resistance by sustaining DNA damage-mediated mTOR signaling through interactions with DNA-PKcs (DNA-dependent protein kinase catalytic subunit). Taken together, these findings indicate that mEAK-7 may be a promising therapeutic target against tumors. However, the precise molecular mechanisms and signal transduction pathways of mEAK-7 in cancer remain largely unknown, motivating the need for further investigation. Here, we summarize the current known roles of mEAK-7 in normal physiology and cancer development by reviewing the latest studies and discuss potential future developments of mEAK-7 in targeted cancer therapy.

Comparative ontogeny and phylogenetic relationships of eight lizardfish species (Synodontidae) from the Northwest Pacific, with a focus on Trachinocephalus monophyly.

Lizardfish (Aulopiforms: Synodontidae), distributed broadly in temperate to tropical waters, are represented globally by 83 species across four genera, with 10 species in Korea. Despite these numbers, few studies have been conducted on the early life history of lizardfishes compared to their adult counterparts. Thus, we conducted molecular identification of 123 Synodontidae larvae collected from the Northwest Pacific (Korea Strait, Yellow Sea, East China Sea, and East Sea) between June 2017 and July 2021, using mitochondrial DNA COI and 16S rRNA sequences. Significant morphological differences were observed in the larvae and juvenile, including variation in melanophore, count, morphometric characteristics, and body shape. The morphological traits of eight species (Harpadon nehereus, Saurida macrolepis, Saurida wanieso, Saurida sp., Synodus hoshinonis, Synodus kaianus, Synodus macrops, and Trachinocephalus trachinus) served as vital data for interpreting the phylogenetic relationships within the Northwest Pacific Synodontidae. Ultimately, the identification key revealed by this study will enable accurate identification of Synodontid larvae and juveniles, and further facilitate our understanding of the phylogenetic relationships within this family.

Selective Inhibition of mTORC1 Signaling Supports the Development and Maintenance of Pluripotency.

Insight into the molecular mechanisms governing the development and maintenance of pluripotency is important for understanding early development and the use of stem cells in regenerative medicine. We demonstrate the selective inhibition of mTORC1 signaling is important for developing the inner cell mass (ICM) and the self-renewal of human embryonic stem cells. S6K suppressed the expression and function of pluripotency-related transcription factors (PTFs) OCT4, SOX2, and KLF4 through phosphorylation and ubiquitin proteasome-mediated protein degradation, indicating that S6K inhibition is required for pluripotency. PTFs inhibited mTOR signaling. The phosphorylation of S6 was decreased in PTF-positive cells of the ICM in embryos. Activation of mTORC1 signaling blocked ICM formation and the selective inhibition of S6K by rapamycin increased the ICM size in mouse blastocysts. Thus, selective inhibition of mTORC1 signaling supports the development and maintenance of pluripotency.

Chromosome-level genome assembly of chub mackerel (Scomber japonicus) from the Indo-Pacific Ocean.

Chub mackerels (Scomber japonicus) are a migratory marine fish widely distributed in the Indo-Pacific Ocean. They are globally consumed for their high Omega-3 content, but their population is declining due to global warming. Here, we generated the first chromosome-level genome assembly of chub mackerel (fScoJap1) using the Vertebrate Genomes Project assembly pipeline with PacBio HiFi genomic sequencing and Arima Hi-C chromosome contact data. The final assembly is 828.68 Mb with 24 chromosomes, nearly all containing telomeric repeats at their ends. We annotated 31,656 genes and discovered that approximately 2.19% of the genome contained DNA transposon elements repressed within duplicated genes. Analyzing 5-methylcytosine (5mC) modifications using HiFi reads, we observed open/close chromatin patterns at gene promoters, including the FADS2 gene involved in Omega-3 production. This chromosome-level reference genome provides unprecedented opportunities for advancing our knowledge of chub mackerels in biology, industry, and conservation.

Mycoplasma hyorhinis infection promotes TNF-α signaling and SMAC mimetic-mediated apoptosis in human prostate cancer.

Growing evidence suggests an association between Mycoplasma infections and the development and progression of prostate cancer (PCa). In this study, we report that chronic and persistent M. hyorhinis infection induced robust TNF-α secretion from PCa cells. TNF-α secreted from M. hyorhinis-infected PCa cells subsequently led to activation of the NF-κB pathway. Chronic M. hyorhinis infection induced gene expression of pro-inflammatory cytokines and chemokines in a NF-κB-dependent manner and promoted cell proliferation, migration, and invasion in PCa cells. The elimination of M. hyorhinis in PCa cells significantly blocked TNF-α secretion, gene expression of cytokines and chemokines, migration, and invasion in PCa cells, suggesting M. hyorhinis-induced TNF-α plays an important role to promote malignant transformation of PCa. Furthermore, second mitochondria-derived activator of caspases (SMAC) mimetics potentiated caspase activation and cell death in M. hyorhinis-infected PCa by antagonizing inhibitor of apoptosis proteins (IAPs) activity. Tissue microarray analysis indicated that TNF-α is co-expressed in M. hyorhinis-infected human patient tissues. Findings from this study advance our understanding of the mycoplasma-oncogenesis process and suggest the potential for new approaches for preventions, diagnosis, and therapeutic approaches against prostate cancers.

Isolation and characterization of single domain antibodies from banded houndshark (Triakis scyllium) targeting SARS-CoV-2 spike RBD protein.

The COVID-19 pandemic has significantly impacted human health for three years. To mitigate the spread of SARS-CoV-2, the development of neutralizing antibodies has been accelerated, including the exploration of alternative antibody formats such as single-domain antibodies. In this study, we identified variable new antigen receptors (VNARs) specific for the receptor binding domain (RBD) of SARS-CoV-2 by immunizing a banded houndshark (Triakis scyllium) with recombinant wild-type RBD. Notably, the CoV2NAR-1 clone showed high binding affinities in the nanomolar range to various RBDs and demonstrated neutralizing activity against SARS-CoV-2 pseudoviruses. These results highlight the potential of the banded houndshark as an animal model for the development of VNAR-based therapeutics or diagnostics against future pandemics.

Analysis of the complete mitochondrial genome sequence of Japanese butterflyfish, Chaetodon nippon (Chaetodontiformes, Chaetodontidae).

Japanese butterflyfish (Chaetodon nippon) belong to the family Chaetodontidae and order Chaetodontiformes. It has circular mitochondrial genome of 16,507 bp in length with 55.4% of A + T content and has 37 genes, including 22 tRNA, 2 rRNA, and 13 protein-coding genes, in addition to a control region. The results of phylogenetic analysis indicated that the C. nippon, C. wiebeli, C. auripes, C. auriga, C. octofasciatus, C. speculum, and C. modestus are closely related to each other. The findings of this study will provide useful genetic information for further phylogenetic and taxonomic classifications of Chaetodontidae.

Complete mitochondrial genome of brown-banded butterflyfish Chaetodon modestus (Chaetodontiformes, Chaetodontidae) and phylogenetic analysis.

The complete mitochondrial genome of the Chaetodon modestus (Temminck and Schlegel, 1844) was first determined in this study, which is 16,490 bp in length, containing 13 protein-coding genes, two rRNA genes, and 22 tRNA. Out of 37 mitochondrial genes, except for ND6 and eight tRNA (Pro, Glu, Ser, Tyr, Cys, Asn, Ala, Gln) genes were encoded on the L-strand, the others were encoded on the H-strand. The overall base composition includes A (28.0%), T (28.7%), G (16.7%), ad C (26.6%). The phylogenetic tree was built using the maximum-likelihood approach to provide a relationship within Chaetodontidae, which might be valuable for species management.

The complete mitochondrial genome of threadfin butterflyfish, Chaetodon auriga (Chaetodontiformes: Chaetodontidae) and phylogenetic analysis.

Chaetodon auriga (Forsskal, 1775) belongs to the family Chaetodontidae and the order Chaetodontiformes. Here, we report the complete mitochondrial genome of C. auriga assembled using the Illumina MiSeq platform. The circular mitochondrial genome of C. auriga is 16,527 bp long, has an A + T content of 54.53%, and contains 37 genes (13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes), and a non-coding region. The overall nucleotide composition was A: 28.19%, T: 26.34%, G: 16.27%, and C: 29.20%. The mitochondrial genome of C. auriga contributes to revealing the phylogenetic relationships among species of the Chaetodontidae family.

New descriptions of four larval lanternfish species and cryptic diversity of Benthosema pterotum (Pisces: Myctophidae) from the Northwest Pacific.

Although there have been many studies on the taxonomy of lanternfishes, morphological similarities during larval and juvenile stages make it difficult to identify species and understand their early life histories. During an ichthyoplankton survey in the Northwest Pacific (East Sea, East China Sea) between 2017 and 2020, a research vessel from the National Institute of Fisheries Science collected larvae and juveniles that belonged to the family Myctophidae using a bongo net. To accurately identify species, mtDNA sequences encoding cytochrome c oxidase subunit I and 16S ribosomal RNA were obtained and compared with those of adult voucher specimens. These comparisons led to the identification of four previously unknown larval lanternfish species (Diaphus chrysorhynchus, Diaphus suborbitalis, Diaphus watasei and Lampanyctus fernae), which are described here for the first time. The authors also describe the cryptic diversity of Benthosema pterotum and provide identification keys for 10 species of larval lanternfish, in accordance with their developmental stages.

Shallow population structure of southern bluefin tuna, Thunnus maccoyii (Castelnau, 1872) between Indian and Atlantic Oceans inferred from mitochondrial DNA sequences.

Southern bluefin tuna (Thunnus maccoyii Castelnau, 1872) is distributed across most of the southern temperate ocean and migrates extensively between 30°S and 50°S. Since T. maccoyii has been continually and heavily exploited, it is necessary to investigate the genetic diversity, population structure and demographic history of T. maccoyii for effective management and conservation. Thirty-seven gonad tissues of T. maccoyii were sampled from two locations, which were in the eastern Indian Ocean and the eastern Atlantic Ocean, by scientific observers onboard Korean T. maccoyii longline vessels in 2015. We compared 1240-bp sequences of combined mitochondrial DNA (mtDNA) from the cytochrome c oxidase subunit I (COI, 504-bp) and control region (CR, 736-bp) sequences. The pairwise fixation index (F ST) and maximum-likelihood tree showed that two clades (A and B) were formed regardless of locations. Clade A occurred more commonly than clade B in both localities: the occurrence ratio of clade A was 69% in the Indian Ocean, and 79% in the Atlantic Ocean, respectively. Our findings suggest that a historic differentiation event may have occurred in T. maccoyii, but recently the connectivity between the two oceans may be possible in T. maccoyii populations.

Whitlockite-Enabled Hydrogel for Craniofacial Bone Regeneration.

Growth-factor-free bone regeneration remains a challenge in craniofacial engineering. Here, we engineered an osteogenic niche composed of a commercially modified alginate hydrogel and whitlockite microparticles (WHMPs), which impart tunable physicochemical properties that can direct osteogenesis of human gingival mesenchymal stem cells (GMSCs). Our in vitro studies demonstrate that WHMPs induce osteogenesis of GMSCs more effectively than previously demonstrated hydroxyapatite microparticles (HApMPs). Alginate-WHMP hydrogels showed higher elasticity without any adverse effects on the viability of the encapsulated GMSCs. Moreover, the alginate-WHMP hydrogels upregulate the mitogen-activated protein kinase (MAPK) pathway, which in turn orchestrates several osteogenic markers, such as RUNX2 and OCN, in the encapsulated GMSCs. Concurrent coculture studies with human osteoclasts demonstrate that GMSCs encapsulated in alginate-WHMP hydrogels downregulate osteoclastic activity, potentially due to release of Mg2+ ions from the WHMPs along with secretion of osteoprotegerin from the GMSCs. In vivo studies demonstrated that the GMSCs encapsulated in our osteogenic niche were able to promote bone repair in calvarial defects in murine models. Altogether, our results confirmed the development of a promising treatment modality for craniofacial bone regeneration based on an injectable growth-factor-free hydrogel delivery system.

CD276 expression enables squamous cell carcinoma stem cells to evade immune surveillance.

Immunosurveillance is a critical mechanism guarding against tumor development and progression. Checkpoint inhibitors have shown significant success in cancer treatment, but expression of key factors such as PD-L1 in putative cancer stem cell (CSC) populations in squamous cell carcinoma has been inconclusive, suggesting that CSCs may have developed other mechanisms to escape immune surveillance. Here we show that CSCs upregulate the immune checkpoint molecule CD276 (B7-H3) to evade host immune responses. CD276 is highly expressed by CSCs in mouse and human head and neck squamous cell carcinoma (HNSCC) and can be used to prospectively isolate tumorigenic CSCs. Anti-CD276 antibodies eliminate CSCs in a CD8+ T cell-dependent manner, inhibiting tumor growth and lymph node metastases in a mouse HNSCC model. Single-cell RNA sequencing (RNA-seq) showed that CD276 blockade remodels SCC heterogeneity and reduces epithelial-mesenchymal transition. These results show that CSCs utilize CD276 for immune escape and suggest that targeting CD276 may reduce CSCs in HNSCC.

Molecular and morphological comparison of larvae and juveniles of five species of callionymids, with ontogenetic evidence on the monophyly of Repomucenus (Callionymidae).

Dragonet fishes (Callionymidae) are benthic inhabitants of shallow waters, even in tidal pools, down to depths below 900 m in all subtropical, tropical and temperate oceans. The family comprises 200 species in 20 genera worldwide, of which 18 species in 6 genera occur in Korea. Classification within the family Callionymidae has been controversial because of the differing proposals of Fricke and Nakabo (Fishes of Japan with pictorial keys to the species, 1983). For example, Fricke suggested genus Repomucenus and Bathycallionymus, whose genera contains most callionymid species in Korean waters, as junior synonym of genus Callionymus while Nakabo (Fishes of Japan with pictorial keys to the species, 1983) suggested as valid. In such cases, when classifications of adults have taxonomic contention, examination of larval characters may prove informative. Therefore, in this study, the authors conducted comprehensive molecular and morphological analyses on larvae and juveniles of five species in the genus Repomucenus and discussed their taxonomic status within the family Callionymidae. Larval and juvenile callionymids show high morphological similarities during their ontogenetic development. Nonetheless, the following morphological differences were observed in melanophore distribution and preopercular spine development: (a) stellate or punctate melanophores in Bathycallionymus kaianus vs. branched melanophores in genus Repomucenus, (b) melanophores on the abdominal cavity gradually disappearing in B. kaianus vs. gradually becoming prominent in Repomucenus and (c) preopercular spine development giving rise to one perpendicular spine in B. kaianus vs. two or three spines in Repomucenus. Molecular analysis based on 16S ribosomal RNA showed similar results to the morphological analysis. Genera Bathycallionymus and Repomucenus showed significant genetic distance (d = 0.113-0.120); moreover, genus Callionymus, which was suggested as a senior synonym of genus Bathycallionymus and Repomucenus by Fricke (Journal of Natural History, 2014, 48, 2419-2448), also showed considerable difference (d = 0.226-0.246). In the present study, the monophyly of genus Repomucenus seemed well supported by the results of morphological and molecular analyses of larval stage Callionymidae.

MicroRNA-1911-3p targets mEAK-7 to suppress mTOR signaling in human lung cancer cells.

Regulation of mTOR signaling depends on an intricate interplay of post-translational protein modification. Recently, mEAK-7 (mTOR associated protein, eak-7 homolog) was identified as a positive activator of mTOR signaling via an alternative mTOR complex. However, the upstream regulation of mEAK-7 in human cells is not known. Because microRNAs are capable of modulating protein translation of RNA in eukaryotes, we conducted a bioinformatic search for relevant mEAK-7 targeting microRNAs using the Exiqon miRSearch V3.0 algorithm. Based on the score obtained through miRSearch V3.0, the top predicted miRNA (miR-1911-3p) was studied. miR-1911-3p mimics decreased protein levels of both mEAK-7 and mTORC1 downstream effectors p-S6 and p-4E-BP1 in non-small cell lung carcinoma (NSCLC) cell lines H1975 and H1299. miR-1911-3p levels and MEAK7 mRNA/mEAK-7/mTOR signaling levels were negatively correlated between normal lung and NSCLC cells. miR-1911-3p directly interacted with MEAK7 mRNA at the 3'-UTR to negatively regulate mEAK-7 and significantly decreased mTOR localization to the lysosome. Furthermore, miR-1911-3p significantly decreased cell proliferation and migration in both H1975 and H1299 cells. Thus, miR-1911-3p functions as a suppressor of mTOR signaling through the regulation of MEAK7 mRNA translation in human cancer cells.

Encapsulation of Se into Hierarchically Porous Carbon Microspheres with Optimized Pore Structure for Advanced Na-Se and K-Se Batteries.

Sodium-selenium (Na-Se) and potassium-selenium (K-Se) batteries have emerged as promising energy storage systems with high energy density and low cost. However, major issues such as huge Se volume changes, polyselenide shuttling, and low Se loading need to be overcome. Although many strategies have been developed to resolve these issues, the relationship between the carbon host pore structure and electrochemical performance of Se has not been studied extensively. Here, the effect of the carbon host pore structure on the electrochemical performance of Na-Se and K-Se batteries is investigated. N, S-co-doped hierarchically porous carbon microspheres with different pore structures that can incorporate a large amount of amorphous Se (∼60 wt %) are synthesized by spray pyrolysis and subsequent chemical activation at different temperatures. By optimizing the amount of micropore volume and micropore-to-mesopore ratio, high reversible capacity and cycling stability are achieved for the Se cathode. The optimized cathode delivers a reversible capacity of 445 mA h g-1 after 400 cycles at 0.5C for Na-Se batteries and 436 mA h g-1 after 120 cycles at 0.2C for K-Se batteries. This study marks the importance of developing conductive carbon matrices with delicately designed pore structures for advanced alkali metal-chalcogen battery systems.

CXCL12γ induces human prostate and mammary gland development.

BACKGROUND: Epithelial stem cells (ESCs) demonstrate a capacity to maintain normal tissues homeostasis and ESCs with a deregulated behavior can contribute to cancer development. The ability to reprogram normal tissue epithelial cells into prostate or mammary stem-like cells holds great promise to help understand cell of origin and lineage plasticity in prostate and breast cancers in addition to understanding normal gland development. We previously showed that an intracellular chemokine, CXCL12γ induced cancer stem cells and neuroendocrine characteristics in both prostate and breast adenocarcinoma cell lines. However, its role in normal prostate or mammary epithelial cell fate and development remains unknown. Therefore, we sought to elucidate the functional role of CXCL12γ in the regulation of ESCs and tissue development. METHODS: Prostate epithelial cells (PNT2) or mammary epithelial cells (MCF10A) with overexpressed CXCL12γ was characterized by quantitative real-time polymerase chain reaction, Western blots, and immunofluorescence for lineage marker expression, and fluorescence activated cell sorting analyses and sphere formation assays to examine stem cell surface phenotype and function. Xenotransplantation animal models were used to evaluate gland or acini formation in vivo. RESULTS: Overexpression of CXCL12γ promotes the reprogramming of cells with a differentiated luminal phenotype to a nonluminal phenotype in both prostate (PNT2) and mammary (MCF10A) epithelial cells. The CXCL12γ-mediated nonluminal type cells results in an increase of epithelial stem-like phenotype including the subpopulation of EPCAMLo /CD49fHi /CD24Lo /CD44Hi cells capable of sphere formation. Critically, overexpression of CXCL12γ promotes the generation of robust gland-like structures from both prostate and mammary epithelial cells in in vivo xenograft animal models. CONCLUSIONS: CXCL12γ supports the reprogramming of epithelial cells into nonluminal cell-derived stem cells, which facilitates gland development.

A new perspective on biogeographic barrier in the flathead grey mullet (Pisces: Mugilidae) from the northwest Pacific.

BACKGROUND: The flathead grey mullet, Mugil cephalus has a global distribution in tropical, subtropical and temperate seas worldwide. Previous studies proposed that globally distributed M. cephalus comprises at least 14 different lineages, and divided into two or three groups in the northwest Pacific. Therefore, we hypothesized that there may exist at least two lineages in Korea. OBJECTIVE: The aim of this study was to determine the number of lineages of flathead grey mullet in Korea, and detail their biogeographic boundaries, and taxonomic implications using various molecular markers. METHODS: Two partial mitochondrial DNA (mtDNA) gene sequences (COI and 16S rRNA) and nine microsatellite loci were analyzed in 260 individuals from ten locations. RESULTS: Phylogenetic trees from two partial mtDNA gene sequences revealed two distinct lineages of flathead grey mullet (P distance = 0.016-0.021). Lineage 1 (L1) consisted of mullets from all locations except for the Pacific coasts of Japan, while lineage 2 (L2) consisted of mullets from the Jeju Island, Shanghai, and the Pacific coasts of Japan. The STRUCTURE analyses of msat data also revealed two distinct groups. CONCLUSION: This study was the first to reveal the coexistence of two lineages of flathead grey mullet in Korea. L2 was confined to the Jeju Island in Korea, implying a biogeographic boundary between the two lineages. The allopatric distribution and genetic heterogeneity between lineages may be affected by an ancient geographic isolation during the glacial period and maintained due to adaptation to oceanic characteristics. Collectively, the two lineages may be comprised of distinct species.

A new species of hagfish, Eptatretus wandoensis sp. nov. (Agnatha, Myxinidae), from the southwestern Sea of Korea.

Four specimens of the five-gilled white mid-dorsal line hagfish, Eptatretus wandoensis sp. nov. were recently collected from the southwestern Sea of Korea (Wando). This new species has five pairs of gill apertures, 14-18 prebranchial slime pores, 4 branchial slime pores, a dark brown back with a white mid-dorsal line and a white belly. These hagfish are similar to Eptatretus burgeri and Eptatretus minor in having a white mid-dorsal line, but can be readily distinguished by the numbers of gill apertures (5 vs. 6-7), gill pouches (5 vs. 6), and prebranchial slime pores (14-18 vs. > 18), as well as the body color (dark brown back vs. gray or brown pale). In terms of genetic differences, Eptatretus wandoensis could be clearly distinguished from E. burgeri (0.9% in 16S rRNA and 8.5% in cytochrome c oxidase subunit I sequences) and E. minor (4.5% and 13.9%).