Human endogenous retroviruses (HERVs) are suggested to be involved in the development of certain diseases, especially cancers. To elucidate the function of HERV-K Env protein in cancers, an HERV-K env gene knockout (KO) in DLD-1 colorectal cancer cell lines was generated using the CRISPR-Cas9 system. Transcriptome analysis of HERV-K env KO cells using next-generation sequencing (NGS) was performed to identify the key genes associated with the function of HERV-K Env protein. The proliferation of HERV-K env KO cells was significantly reduced in in vitro culture as well as in in vivo nude mouse model. Tumorigenic characteristics, including migration, invasion, and tumor colonization, were also significantly reduced in HERV-K env KO cells. Whereas, they were enhanced in HERV-K env over-expressing DLD-1 cells. The expression of nuclear protein-1 (NUPR1), an ER-stress response factor that plays an important role in cell proliferation, migration, and reactive oxygen species (ROS) generation in cancer cells, significantly reduced in HERV-K env KO cells. ROS levels and ROS-related gene expression was also significantly reduced in HERV-K env KO cells. Cells transfected with NUPR1 siRNA (small interfering RNA) exhibited the same phenotype as HERV-K env KO cells. These results suggest that the HERV-K env gene affects tumorigenic characteristics, including cell proliferation, migration, and tumor colonization through NUPR1 related pathway.

Eun-Ji Ko, Kyoung Seob Song, Mee Sun Ock, Yung Hyun Choi, Suhkmann Kim, Heui-Soo Kim & Hee-Jae Cha. BMB Reports 2021;54:368-73. https://doi.org/10.5483/BMBRep.2021.54.7.246

Tight junction (TJ) proteins (Tjps), Tjp1 and Tjp2, are tight junction-associated scaffold proteins that bind to the transmembrane proteins of tight junctions and the underlying cytoskeleton. In this study, we first analyzed the tumorigenic characteristics of B16-F10 melanoma cells, including cell proliferation, migration, invasion, metastatic potential, and the expression patterns of related proteins, after the CRISPR–Cas9-mediated knockout (KO) of Tjp genes. The proliferation of Tjp1 and Tjp2 KO cells significantly increased in vitro. Other tumorigenic characteristics, including migration and invasion, were significantly enhanced in Tjp1 and Tjp2 KO cells. Zonula occludens (ZO)-associated protein Claudin-1 (CLDN-1), which is a major component of tight junctions and functions in controlling cell-to-cell adhesion, was decreased in Tjp KO cells. Additionally, Tjp KO significantly stimulated tumor growth and metastasis in an in vivo mouse model. We performed a transcriptome analysis using next-generation sequencing (NGS) to elucidate the key genes involved in the mechanisms of action of Tjp1 and Tjp2. Among the various genes affected by Tjp KO-, cell cycle-, cell migration-, angiogenesis-, and cell–cell adhesion-related genes were significantly altered. In particular, we found that the Ninjurin-1 (Ninj1) and Catenin alpha-1 (Ctnna1) genes, which are known to play fundamental roles in Tjps, were significantly downregulated in Tjp KO cells. In summary, tumorigenic characteristics, including cell proliferation, migration, invasion, tumor growth, and metastatic potential, were significantly increased in Tjp1 and Tjp2 KO cells, and the knockout of Tjp genes significantly affected the expression of related proteins.

Human endogenous retrovirus (HERV)-K was reportedly inserted into the human genome millions of years ago and is closely related to various diseases, including cancer and immune regulation. In our previous studies, CRISPR-Cas9-enabled knockout (KO) of the HERV-K env gene was found to potentially reduce cell proliferation, cell migration, and invasion in colorectal and ovarian cancer cell lines. The immune response involves the migration and invasion of cells and is similar to cancer; however, in certain ways, it is completely unlike cancer. Therefore, we induced HERV-K119 env gene KO in THP-1, a monocytic cell that can be differentiated into a macrophage, to investigate the role of HERV-K119 env in immune regulation. Cell migration and invasion were noted to be significantly increased in HERV-K119 env KO THP-1 cells than in MOCK, and these results were contrary to those of cancer cells. To identify the underlying mechanism of HERV-K119 env KO in THP-1 cells, transcriptome analysis and cytokine array analysis were conducted. Semaphorin7A (SEMA7A), which induces the production of cytokines in macrophages and monocytic cells and plays an important role in immune effector cell activation during an inflammatory immune response, was significantly increased in HERV-K119 env KO THP-1 cells. We also found that HERV-K119 env KO THP-1 cells expressed various macrophage-specific surface markers, suggesting that KO of HERV-K119 env triggers the differentiation of THP-1 cells from monocytic cells into macrophages. In addition, analysis of the expression of M1 and M2 macrophage markers showed that M1 macrophage marker cluster of differentiation 32 (CD32) was significantly increased in HERV-K119 env KO cells. These results suggest that HERV-K119 env is implicated in the differentiation of monocytic cells into M1 macrophages and plays important roles in the immune response.

Background: Particulate matter (PM) is a major environmental pollutant that induces oxidative stress, inflammation, and extracellular matrix (ECM) degradation, leading to skin damage and accelerated aging. Xanthorrhizol (XAN), a bioactive compound derived from Curcuma xanthorrhiza Roxb., exhibits anti-inflammatory and antioxidative properties, making it a promising candidate for protecting against PM-induced skin damage. This study investigated the protective effects of XAN and C. xanthorrhiza supercritical extract (CXSE) on PM-exposed skin cells. Methods: A 3D-reconstructed skin model and HaCaT human keratinocytes were exposed to PM (100 µg/mL) with or without CXSE or XAN. Histological analysis, enzyme-linked immunosorbent assay (ELISA), Western blot, reverse transcription-polymerase chain reaction (RT-PCR), and reporter gene assays were performed to assess the ECM integrity, inflammatory cytokine production, aryl hydrocarbon receptor (AhR) activation, and oxidative stress responses. Results: PM exposure activates AhR and mitogen-activated protein kinases (MAPK) signaling, increases reactive oxygen species (ROS) levels, and upregulates matrix metalloproteinases (MMPs) and inflammatory cytokines. CXSE and XAN suppresses AhR-mediated transcriptional activity and downregulates the expression of AhR target genes. Additionally, CXSE and XAN reduces ROS production by upregulating antioxidant enzyme-related genes. Conclusions: CXSE and XAN protect against PM-induced skin damage by inhibiting oxidative stress, inflammation, and ECM degradation, highlighting their potential as natural anti-pollution skincare ingredients.

Background: The scuticociliate Miamiensis avidus is a major pathogenic agent that causes significant economic losses in the flounder aquaculture industry. Many different types of drugs are being tested to control this disease, including mebendazole, which is a broad-spectrum antiprotozoal agent. The purpose of this study was to determine whether mebendazole worked in vitro against M. avidus and to explore its mechanism of action. Methods: Transcriptome and gene ontology analyses were conducted to investigate the specifically expressed gene profile. We confirmed the cytotoxic effect of mebendazole against M. avidus when it was applied intermittently for a total of three times. We also identified differentially expressed genes using transcriptome analysis. Results: Most of the upregulated genes were membrane transport-related genes, including Na+/K+-ATPase. Most of the downregulated genes were categorized into three groups: tubulin-related, metabolism-related, and transport-related genes. The expression levels of glucose uptake-related genes decreased due to the inhibition of tubulin polymerization, but this was not statistically significant.Conclusions: Our results demonstrate that intermittent treatment with mebendazole has a significant cytotoxic effect on M. avidus. Furthermore, mebendazole induces downregulation of the tubulin-alpha chain and metabolism-related genes. It is presumed that this leads to a glucose shortage and the death of M. avidus. Transcriptome analysis will provide useful clues for further studies on mebendazole applications for scutica control.