• Molecules and Cells
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• v.45 no.6
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• pp.425-434
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• 2022

The post-translational modification (e.g., phosphorylation) of estrogen receptor α (ERα) plays a role in controlling the expression and subcellular localization of ERα as well as its sensitivity to hormone response. Here, we show that ERα is also modified by UFM1 and this modification (ufmylation) plays a crucial role in promoting the stability and transactivity of ERα, which in turn promotes breast cancer development. The elevation of ufmylation via the knockdown of UFSP2 (the UFM1-deconjugating enzyme in humans) dramatically increases ERα stability by inhibiting ubiquitination. In contrast, ERα stability is decreased by the prevention of ufmylation via the silencing of UBA5 (the UFM1-activating E1 enzyme). Lys171 and Lys180 of ERα were identified as the major UFM1 acceptor sites, and the replacement of both Lys residues by Arg (2KR mutation) markedly reduced ERα stability. Moreover, the 2KR mutation abrogated the 17β-estradiol-induced transactivity of ERα and the expression of its downstream target genes, including pS2, cyclin D1, and c-Myc; this indicates that ERα ufmylation is required for its transactivation function. In addition, the 2KR mutation prevented anchorage-independent colony formation by MCF7 cells. Most notably, the expression of UFM1 and its conjugating machinery (i.e., UBA5, UFC1, UFL1, and UFBP1) were dramatically upregulated in ERα-positive breast cancer cell lines and tissues. Collectively, these findings implicate a critical role attributed to ERα ufmylation in breast cancer development by ameliorating its stability and transactivity.

• Genomics & Informatics
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• v.20 no.3
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• pp.27.1-27.13
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• 2022

Oral squamous cell carcinoma (OSCC) is the most prevalent head and neck malignancy, with frequent cervical lymph-node metastasis, leading to a poor prognosis in OSCC patients. The present study aimed to identify potential markers, including microRNAs (miRNAs) and genes, significantly involved in the etiology of early-stage OSCC. Additionally, the main OSCC's dysregulated Gene Ontology annotations and significant signaling pathways were identified. The dataset GSE45238 underwent multivariate statistical analysis in order to distinguish primary OSCC tissues from healthy oral epithelium. Differentially expressed miRNAs (DEMs) with the criteria of p-value < 0.001 and |Log2 fold change| > 1.585 were identified in the two groups, and subsequently, validated targets of DEMs were identified. A protein interaction map was constructed, hub genes were identified, significant modules within the network were illustrated, and significant pathways and biological processes associated with the clusters were demonstrated. Using the GEPI2 database, the hub genes' predictive function was assessed. Compared to the healthy controls, main OSCC had a total of 23 DEMs. In patients with head and neck squamous cell carcinoma (HNSCC), upregulation of CALM1, CYCS, THBS1, MYC, GATA6, and SPRED3 was strongly associated with a poor prognosis. In HNSCC patients, overexpression of PIK3R3, GIGYF1, and BCL2L11 was substantially correlated with a good prognosis. Besides, "proteoglycans in cancer" was the most significant pathway enriched in the primary OSCC. The present study results revealed more possible mechanisms mediating primary OSCC and may be useful in the prognosis of the patients with early-stage OSCC.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1245-1252
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• 2022

Induced pluripotent stem cells (iPSCs) can be generated from somatic cells using Oct4, Sox2, Klf4, and c-Myc (OSKM). Small molecules can enhance reprogramming. Licochalcone D (LCD), a flavonoid compound present mainly in the roots of Glycyrrhiza inflata, acts on known signaling pathways involved in transcriptional activity and signal transduction, including the PGC1-α and MAPK families. In this study, we demonstrated that LCD improved reprogramming efficiency. LCD-treated iPSCs (LCD-iPSCs) expressed pluripotency-related genes Oct4, Sox2, Nanog, and Prdm14. Moreover, LCD-iPSCs differentiated into all three germ layers in vitro and formed chimeras. The mesenchymal-to-epithelial transition (MET) is critical for somatic cell reprogramming. We found that the expression levels of mesenchymal genes (Snail2 and Twist) decreased and those of epithelial genes (DSP, Cldn3, Crb3, and Ocln) dramatically increased in OR-MEF (OG2^+/+/ROSA26^+/+) cells treated with LCD for 3 days, indicating that MET effectively occurred in LCD-treated OR-MEF cells. Thus, LCD enhanced the generation of iPSCs from somatic cells by promoting MET at the early stages of reprogramming.

• Molecules and Cells
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• v.45 no.9
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• pp.660-672
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• 2022

The target of rapamycin complex (TORC) plays a key role in plant cell growth and survival by regulating the gene expression and metabolism according to environmental information. TORC activates transcription, mRNA translation, and anabolic processes under favorable conditions, thereby promoting plant growth and development. Tomato fruit ripening is a complex developmental process promoted by ethylene and specific transcription factors. TORC is known to modulate leaf senescence in tomato. In this study, we investigated the function of TORC in tomato fruit ripening using virus-induced gene silencing (VIGS) of the TORC genes, TOR, lethal with SEC13 protein 8 (LST8), and regulatory-associated protein of TOR (RAPTOR). Quantitative reverse transcription-polymerase chain reaction showed that the expression levels of tomato TORC genes were the highest in the orange stage during fruit development in Micro-Tom tomato. VIGS of these TORC genes using stage 2 tomato accelerated fruit ripening with premature orange/red coloring and decreased fruit growth, when control tobacco rattle virus 2 (TRV2)-myc fruits reached the mature green stage. TORC-deficient fruits showed early accumulation of carotenoid lycopene and reduced cellulose deposition in pericarp cell walls. The early ripening fruits had higher levels of transcripts related to fruit ripening transcription factors, ethylene biosynthesis, carotenoid synthesis, and cell wall modification. Finally, the early ripening phenotype in Micro-Tom tomato was reproduced in the commercial cultivar Moneymaker tomato by VIGS of the TORC genes. Collectively, these results demonstrate that TORC plays an important role in tomato fruit ripening by modulating the transcription of various ripening-related genes.

• Journal of Physiology & Pathology in Korean Medicine
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• v.36 no.6
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• pp.229-234
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• 2022

Lung cancer is the leading cause of cancer-related deaths worldwide. Indigo Naturalis (IN) is a dark blue powder obtained by processing leaves or stems of indigo plants, its anticancer effects have been reported in several studies. However, the pharmacological mechanism of IN in small cell lung cancer (SCLC) is not elucidated. In this study, to investigate the anticancer efficacy of IN for SCLC, we presented potential active ingredients, SCLC-related targets, and pharmacological mechanisms of IN that are expected to have anticancer activity for SCLC using a network pharmacological analysis. The phytochemical compounds of IN have been collected through TCMSP, SymMap, or HPLC documents. The active ingredients of IN such as indirubin, indican, isatin, and tryptanthrin were selected through ADME parameters or literature investigations for each compound. Using the Compounds, Disease-Target associations Databases, 124 common targets of IN and SCLC were obtained. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway enrichment analysis was carried out. GO biological processes are associated with response to xenobiotic stimulus, positive regulation of protein phosphorylation, regulation of mitotic cell cycle, and regulation of apoptotic signaling pathway. KEGG disease pathways included Gastric cancer, Bladder cancer, SCLC, and Melanoma. The main anticancer targets of the IN for SCLC were analyzed in 14 targets, including BCL2, MYC, and TP53. In conclusion, the results of this study based on the network pharmacology of IN can provide important data for the effective prevention and treatment of SCLC.

• Applied Microscopy
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• v.51
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• pp.20.1-20.12
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• 2021

We explored the link between mitochondrial biogenesis and mitochondrial morphology using transmission electron microscopy (TEM) in lymphoblasts of pediatric acute lymphoblastic leukemia (ALL) patients and compared these characteristics between tumors and control samples. Gene expression of mitochondrial biogenesis markers was analysed in 23 ALL patients and 18 controls and TEM for morphology analysis was done in 15 ALL patients and 9 healthy controls. The area occupied by mitochondria per cell and the cristae cross-sectional area was observed to be significantly higher in patients than in controls (p-value=0.0468 and p-value<0.0001, respectively). The mtDNA copy numbers, TFAM, POLG, and c-myc gene expression were significantly higher in ALL patients than controls (all p-values<0.01). Gene Expression of PGC-1α was higher in tumor samples. The analysis of the correlation between PGC-1α expression and morphology parameters i.e., both M/C ratio and cristae cross-sectional area revealed a positive trend (r=0.3, p=0.1). The increased area occupied by mitochondria and increased cristae area support the occurrence of cristae remodelling in ALL. These changes might reflect alterations in cristae dynamics to support the metabolic state of the cells by forming a more condensed network. Ultrastructural imaging can be useful for affirming changes occurring at a subcellular organellar level.

• Molecules and Cells
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• v.46 no.4
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• pp.209-218
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• 2023

In induced pluripotent stem cells (iPSCs), pluripotency is induced artificially by introducing the transcription factors Oct4, Sox2, Klf4, and c-Myc. When a transgene is introduced using a viral vector, the transgene may be integrated into the host genome and cause a mutation and cancer. No integration occurs when an episomal vector is used, but this method has a limitation in that remnants of the virus or vector remain in the cell, which limits the use of such iPSCs in therapeutic applications. Chemical reprogramming, which relies on treatment with small-molecule compounds to induce pluripotency, can overcome this problem. In this method, reprogramming is induced according to the gene expression pattern of extra-embryonic endoderm (XEN) cells, which are used as an intermediate stage in pluripotency induction. Therefore, iPSCs can be induced only from established XEN cells. We induced XEN cells using small molecules that modulate a signaling pathway and affect epigenetic modifications, and devised a culture method which can produce homogeneous XEN cells. At least 4 passages were required to establish morphologically homogeneous chemically induced XEN (CiXEN) cells, whose properties were similar to those of XEN cells, as revealed through cellular and molecular characterization. Chemically iPSCs derived from CiXEN cells showed characteristics similar to those of mouse embryonic stem cells. Our results show that the homogeneity of CiXEN cells is critical for the efficient induction of pluripotency by chemicals.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.4
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• pp.199-208
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• 2023

Background: Canine induced pluripotent stem cells (iPSCs) are an attractive source for veterinary regenerative medicine, disease modeling, and drug development. Here we used vitamin C (Vc) to improve the reprogramming efficiency of canine iPSCs, and its functions in the reprogramming process were elucidated. Methods: Retroviral transduction of Oct4, Sox2, Klf4, c-Myc (OSKM), and GFP was employed to induce reprogramming in canine fetal fibroblasts. Following transduction, the culture medium was subsequently replaced with ESC medium containing Vc to determine the effect on reprogramming activity. Results: The number of AP-positive iPSC colonies dramatically increased in culture conditions supplemented with Vc. Vc enhanced the efficacy of retrovirus transduction, which appears to be correlated with enhanced cell proliferation capacity. To confirm the characteristics of the Vc-treated iPSCs, the cells were cultured to passage 5, and pluripotency markers including Oct4, Sox2, Nanog, and Tra-1-60 were observed by immunocytochemistry. The expression of endogenous pluripotent genes (Oct4, Nanog, Rex1, and telomerase) were also verified by PCR. The complete silencing of exogenously transduced human OSKM factors was observed exclusively in canine iPSCs treated with Vc. Canine iPSCs treated with Vc are capable of forming embryoid bodies in vitro and have spontaneously differentiated into three germ layers. Conclusions: Our findings emphasize a straightforward method for enhancing the efficiency of canine iPSC generation and provide insight into the Vc effect on the reprogramming process.

• International Journal of Stem Cells
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• v.16 no.1
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• pp.36-43
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• 2023

Background and Objectives: Lymphoblastoid cell lines (LCLs) deposited from disease-affected individuals could be a valuable donor cell source for generating disease-specific induced pluripotent stem cells (iPSCs). However, generation of iPSCs from the LCLs is still challenging, as yet no effective gene delivery strategy has been developed. Methods and Results: Here, we reveal an effective gene delivery method specifically for LCLs. We found that LCLs appear to be refractory toward retroviral and lentiviral transduction. Consequently, lentiviral and retroviral transduction of OCT4, SOX2, KFL4 and c-MYC into LCLs does not elicit iPSC colony formation. Interestingly, however we found that transfection of oriP/EBNA-1-based episomal vectors by electroporation is an efficient gene delivery system into LCLs, enabling iPSC generation from LCLs. These iPSCs expressed pluripotency makers (OCT4, NANOG, SSEA4, SALL4) and could form embryoid bodies. Conclusions: Our data show that electroporation is an effective gene delivery method with which LCLs can be efficiently reprogrammed into iPSCs.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1186-1193
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• 2003

Purpose : Fragile sites are points on chromosomes which tend to break non-randomly when exposed to specific chemical agents or conditions of tissue culture. The chromosomal break induced by the antineoplastic drug, 1-${\beta}$-D-arabinofuranosyl-cytosine(Ara-c), was investigated to study the laboratory conditions in which the incidence of chromosomal break could be enhanced. Besides, the fragile sites induced by Ara-C were investigated and compared to the already known locations of the specific chromosomal alterations observed in specific neoplasms. Methods : T-lymphocytes from theree normal males and three females were cultured for 48 hours. Cells from each individual were exposed to the Ara-C for an additional 24 hours. After the caffeine was added during the last six hours culture, the metaphase chromosomes were prepared following the conventional method. A site was considered fragile if it was found to break two or more per 100 chromosomal breaks in more than four of six individuals tested. Results : Ara-C induced 252.1 chromosomal breaks per 100 mitotic cells and this result was significantly higher than that of the control, which induced 25.2 breaks(P<0.05). The incidence of the chromosomal break by Ara-C was higher, if cultured in the MEM-FA, which has no folic acid, than in the RPMI 1640 which contains enough folic acid(P<0.05). The most common break site by Ara-C was 3p14.2(FRA3B). There were 20 fragile sites induced by Ara-C. Among these 20 fragile sites, seven coincided with the locations of the mapped oncogenes, JUN, SKI, REL, N-MYC, FHIT, MET, ETS-1, and FOS. Conclusion : S phase specific chemotherapeutic agent, Ara-C, induced the expression of the chromosomal fragile sites effectively using the T-lymphocyte in vitro. Some of the fragile sites by Ara-C highly coincided with the oncogenes and neoplasm specific chromosome breakpoints. In this regard, the fragile sites reported here could provide the unknown neoplasm related chromosomal alternation points.