Transcriptome analysis of the effect of HERV-K env gene knockout in ovarian cancer cell lines.

BACKGROUND: Human endogenous retroviruses (HERVs) have been implicated in the pathogenesis of various diseases, particularly cancers. Previous investigations from our group demonstrated that targeted knockout (KO) of the HERV-K env gene led to a significant reduction in tumorigenic attributes, including proliferation, migration, and invasion of ovarian cancer cells. OBJECTIVE: In this study, we aimed to elucidate the impact of HERV-K env KO on gene expression in ovarian cancer cell lines through comparative RNA sequencing (RNA-Seq) analysis with two distinct HERV-K env KO ovarian cancer cell lines, SKOV3 and OVCAR3. METHODS: HERV-K env gene KO was achieved in SKOV3 and OVCAR3 ovarian cancer cell lines using the CRISPR-Cas9 system. Next-generation mRNA sequencing was employed to assess the gene expression profiles of both mock and HERV-K env KO ovarian cancer cells. Furthermore, comprehensive analyses involving gene ontology and pathway assessments were conducted. RESULTS: Transcriptome analysis revealed that 23 differentially expressed genes (DEGs) were upregulated and 17 DEGs were downregulated in SKOV3 cells. In OVCAR3 cells, 198 DEGs were upregulated, and 17 DEGs were downregulated. Notably, 53 DEGs exhibited statistically significant differences among the 1,612 DEGs identified. Our findings indicate that HERV-K env gene KO exerts a profound influence on gene expression patterns in OVCAR3 cells, while genetic alterations in expression were relatively modest in SKOV3 cells. Nevertheless, genes ND1, ND2, and CYTB displayed a common increase in expression, while ERRFI1 and NDRG1 exhibited a decrease in expression in both cell lines. CONCLUSION: Our study demonstrates that KO of the HERV-K env gene in ovarian cancer cell lines has a substantial impact on gene expression patterns and can be used to identify potential therapeutic targets for ovarian cancer and related diseases.

Correction: Samsuzzaman et al. A Synthetic Derivative SH 66 of Homoisoflavonoid from Liliaceae Exhibits Anti-Neuroinflammatory Activity against LPS-Induced Microglial Cells. Molecules 2024, 29, 3037.

Error in Figure [...].

A Synthetic Derivative SH 66 of Homoisoflavonoid from Liliaceae Exhibits Anti-Neuroinflammatory Activity against LPS-Induced Microglial Cells.

Naturally occurring homoisoflavonoids isolated from some Liliaceae plants have been reported to have diverse biological activities (e.g., antioxidant, anti-inflammatory, and anti-angiogenic effects). The exact mechanism by which homoisoflavonones exert anti-neuroinflammatory effects against activated microglia-induced inflammatory cascades has not been well studied. Here, we aimed to explore the mechanism of homoisoflavonoid SH66 having a potential anti-inflammatory effect in lipopolysaccharide (LPS)-primed BV2 murine microglial cells. Microglia cells were pre-treated with SH66 followed by LPS (100 ng/mL) activation. SH66 treatment attenuated the production of inflammatory mediators, including nitric oxide and proinflammatory cytokines, by down-regulating mitogen-activated protein kinase signaling in LPS-activated microglia. The SH66-mediated inhibition of the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome complex and the respective inflammatory biomarker-like active interleukin (IL)-1ß were noted to be one of the key pathways of the anti-inflammatory effect. In addition, SH66 increased the neurite length in the N2a neuronal cell and the level of nerve growth factor in the C6 astrocyte cell. Our results demonstrated the anti-neuroinflammatory effect of SH66 against LPS-activated microglia-mediated inflammatory events by down-regulating the NLRP3 inflammasome complex, with respect to its neuroprotective effect. SH66 could be an interesting candidate for further research and development regarding prophylactics and therapeutics for inflammation-mediated neurological complications.

Correlation analysis of cancer stem cell marker CD133 and human endogenous retrovirus (HERV)-K env in SKOV3 ovarian cancer cells.

BACKGROUND: Human endogenous retrovirus (HERV)-K is a type of retrovirus that is present in the human genome, and its expression is usually silenced in healthy tissues. The precise mechanism by which HERV-K env influences cancer stemness is not fully understood, but it has been suggested that HERV-K env may activate various signaling pathways that promote stemness traits in cancer cells. OBJECTIVE: To establish the connection between HERV-K env expression and cancer stemness in ovarian cancer cells, we carried out correlation analyses between HERV-K env and the cancer stem cell (CSC) marker known as the cluster of differentiation 133 (CD133) gene in SKOV3 ovarian cancer cells. METHOD: To perform correlation analysis between HERV-K env and CSCs, ovarian cancer cells were cultured in a medium designed for cancer stem cell induction. The expression of HERV-K env and CD133 genes was verified using quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot analyses. Additionally, the expression of stemness-related markers, such as OCT-4 and Nanog, was also confirmed using RT-qPCR. RESULTS: In the stem cell induction medium, the number of tumorsphere-type SKOV3 cells increased, and the expression of CD133 and HERV-K env genes was up-regulated. Additionally, other stemness-related markers like OCT-4 and Nanog also exhibited increased expression when cultured in the cancer stem cell induction medium. However, when HERV-K env knockout (KO) SKOV3 cells were cultured in the same cancer stem cell induction medium, there was a significant decrease in the number of tumorsphere-type cells compared to mock SKOV3 cells subjected to the same conditions. Furthermore, the expression of CD133, Nanog, and OCT-4 did not show a significant increase in HERV-K env KO SKOV3 cells compared to mock SKOV3 cells cultured in the same cancer stem cell induction medium. CONCLUSION: These findings indicate that the expression of HERV-K env increased in SKOV3 cells when cultured in cancer stem cell induction media, and cancer stem cell induction was inhibited by KO of HERV-K env in SKOV3 cells. These results suggest a strong association between HERV-K env and stemness in SKOV3 ovarian cancer cells.

Functional Analysis of Membrane-Associated Scaffolding Tight Junction (TJ) Proteins in Tumorigenic Characteristics of B16-F10 Mouse Melanoma Cells.

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.

Anti-neuroinflammatory Effects of Active Compound SPA1413 via Suppression of the MAPK and JAK/STAT Signaling Pathways.

Isoflavones and their derivatives possess neuroprotective activities against neurological disorders. Recently, the active compound SPA1413 (dehydroequol) derived from S-equol, an isoflavone-derived metabolite produced by human intestinal bacteria, was identified as a potent anti-amyloidogenic and neuroinflammatory candidate against Alzheimer's disease. However, its detailed modes of action, associated signaling pathways, and comparison with potential isoflavone derivatives have not yet been studied. Hence, the current study aimed to identify signaling pathways associated with SPA1413 using lipopolysaccharides (LPS)-stimulated BV2 cells as the experimental model via biological assays, Western blotting, and quantitative (q)RT-PCR. The results indicate that the SPA1413 anti-neuroinflammatory effect arises due to suppression of the nitric oxide (NO), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and mitogen-activated protein kinase (MAPK) signaling networks, including those of p38 and c-Jun N-terminal kinase (JNK). Interestingly, SPA1413 inhibited IL-11 through the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway. In addition, SPA1413 inhibited neuronal cell death by reducing LPS-activated microglia in neuronal N2a cells. Our findings suggest that SPA1413 may act as a strong anti-neuroinflammatory candidate by suppressing the MAPK and JAK/STAT signaling pathways.

The Role of Human Endogenous Retrovirus (HERV)-K119 env in THP-1 Monocytic Cell Differentiation.

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.

Effect of parasitic infection on muscular function of dystrophin gene (Dmd) deficient mouse.

BACKGROUND: Previous studies have reported many cases of Trichinella spiralis (T. spiralis) infection in normal skeletal muscle but there is little research on T. spiralis infection in abnormal muscle tissue. OBJECTIVE: To identify the effect of T. spiralis infection on muscular dystrophy, this study compared aspects of infection between normal (C57BL/10) and dystrophin-deficient Duchenne muscular dystrophy (DMD) mdx mice. METHOD: Infection rate was found to be lower in mdx mice than in C57BL/10 mice at early stages of infection; however, infection and inflammation in mdx mice persisted at later stages of infection while the infection rate and inflammation in C57BL/10 mice decreased gradually. The inflammation area was proportional to the degree of infection in both groups. Muscle strength was measured by the time of latency to fall in the wire-hanging test. Hanging time was shorter in the infected group than in the uninfected group in both C57BL/10 and mdx mice. RESULTS: Muscle strength was also reduced in mdx mice compared with C57BL/10 mice in both the un-infected and infected groups. The muscle intracellular cytokines TGF-ß and IL-6 were continuously expressed from early stage to late-stage infection. IL-10 was strongly expressed at the early stage of infection but decreased as the infection progressed. TNF-α expression remained stable from early to late-stage infection in mdx mice, while TNF-α was elevated only during early-stage infection in C57BL/10 mice. The degree of muscle damage was significantly higher in mdx mice than in C57BL/10 mice because of the high level of serum creatine kinase (CK). CONCLUSION: These results suggest that mdx mice continued in infection and inflammation until the late stages of disease, which was in contrast to the C57BL/10 mice that recovered to some extent in the late stage of infection. In addition, that dystrophin-deficient mice are not suitable for T. spiralis infection compared to normal mice, and the degree of inflammation may be worse in mdx mice.

Effect of human endogenous retrovirus-K env gene knockout on proliferation of ovarian cancer cells.

BACKGROUND: Among various human endogenous retroviruses (HERVs), the HERV-K (HML-2) group has been reported to be highly related to cancer. In pancreatic cancer cells, shRNA-mediated downregulation of HERV-K env RNA decreases cell proliferation and tumor growth through the RAS-ERK-RSK pathway; in colorectal cancer, CRISPR-Cas9 knockout (KO) of the HERV-K env gene affects tumorigenic characteristics through the nupr-1 gene. OBJECTIVE: The effect of HERV-K env KO has not been studied in ovarian cancer cell lines. In this study, we analyzed the tumorigenic characteristics of ovarian cancer cell lines, including cell proliferation, migration, and invasion, and the expression patterns of related proteins after CRISPR-Cas9 KO of the HERV-K env gene. METHODS: The HERV-K env gene KO was achieved using the CRISPR-Cas9 system in ovarian cancer cell lines SKOV3 and OVCAR3. Tumorigenic characteristics including cell proliferation, migration, and invasion were analyzed, and related protein expression was investigated by western blot analysis. RESULTS: The expression of the HERV-K env gene in KO cells was significantly reduced at RNA and protein levels, and tumorigenic characteristics including cell proliferation, migration, and invasion were significantly reduced. In HERV-K env KO SKOV3 cells, the expression of the RB protein was significantly up-regulated and the cyclin B1 protein level was significantly reduced. In contrast, in HERV-K env KO OVCAR3 cells, the level of phospho-RB protein was significantly reduced, but other protein levels were not changed. CONCLUSION: The results of this study showed that HERV-K env gene KO affects cell proliferation, invasion, and migration of ovarian cells through RB and Cyclin B1 proteins, but the specific regulation pattern can differ by cell line.

Proteome profile of spleen in rock bream (Oplegnathus fasciatus) naturally infected with rock bream iridovirus (RBIV).

BACKGROUND: Rock bream iridovirus (RBIV) is one of the most dangerous pathogens that causes the highest mortality in the aquaculture of rock bream (Oplegnathus fasciatus). Even though RBIV infection leads to huge economic loss, proteome studies on RBIV-infected rock bream have not been conducted to provide information about the differential protein expression pattern by the host protection system. OBJECTIVE: The purpose of this study was to investigate the protein expression patterns in spleens of rock bream olive after infection by RBIV or mixed infection by RBIV and bacteria. METHODS: Depending on the infection intensity and sampling time point, fish were divided into five groups: uninfected healthy fish at week 0 as the control (0C), heavily infected fish at week 0 (0H), heavily mixed RBIV and bacterial infected fish at week 0 (0MH), uninfected healthy fish at week 3 (3C), and lightly infected fish at week 3 (3L). Proteins were extracted from the spleens of infected rock bream. We used 2-DE analysis with LC-MS/MS to investigate proteome changes in infected rock bream. RESULTS: The results of the LC-MS/MS analyses showed different protein expression profiles after infection. Proteins related to oxygen transport and energy generation, such as hemoglobin, beta-globin, and ATP synthase, were mostly expressed in the infected spleen. Whereas proteins involved in structure and cell movement, such as tubulin, myosin, actin binding proteins, and intermediate filament proteins, were down-regulated in the infected spleens. The protein expression profiles between infection by RBIV and mixed infection by RBIV and bacteria showed similar patterns. CONCLUSIONS: Our results indicated that infection by RBIV or mixed infection by RBIV and bacteria triggered energy generation and oxygen-transport, but cell migration and constructional changes in the spleen were extremely decreased.

Effects of remote ischemic preconditioning on the deformability and aggregation of red blood cells in a rat endotoxemia model.

BACKGROUND: The prevention of rheologic alterations in erythrocytes may be important for reducing sepsis-associated morbidity and mortality. Remote ischemic preconditioning (RIPC) has been shown to prevent tissue damage caused by severe ischemia and mortality resulting from sepsis. However, the effect of RIPC on erythrocytes in sepsis is yet to be determined. OBJECTIVE: To investigate the effect of RIPC on rheologic alterations in erythrocytes in sepsis. METHODS: Thirty male Sprague-Dawley rats were used in this study. An endotoxin-induced sepsis model was established by intraperitoneally injecting 20 mg/kg LPS (LPS group). RIPC was induced in the right hind limb using a tourniquet, with three 10-minute of ischemia and 10 min of reperfusion cycles immediately before the injection of LPS (RIPC/LPS group) or phosphate-buffered saline (RIPC group). The aggregation index (AI), time to half-maximal aggregation (T1/2), and maximal elongation index (EImax) of the erythrocytes were measured 8 h after injection. RESULTS: The AI, T1/2, and EImax values in the LPS and RIPC/LPS groups differed significantly from those in the RIPC group, but there were no differences between the values in the LPS and RIPC/LPS groups. CONCLUSIONS: RIPC did not prevent rheologic alterations in erythrocytes in the rat model of LPS-induced endotoxemia.

Effects of thymosin ß4-derived peptides on migration and invasion of ovarian cancer cells.

BACKGROUND: Thymosin ß4 (Tß4) is a highly conserved actin binding protein associated with the metastatic potential of tumor cells by stimulating cell migration. The role of Tß4 and its derived fragment peptides in migration of ovarian cancer cells has not been studied. OBJECTIVE: To analyze the effects of Tß4 and its derived fragment peptides on ovarian cancer cell migration and invasion, we applied Tß4 and three Tß4-derived synthetic peptides to SKOV3 ovarian cancer cells. METHOD: The migration and invasion of SKOV3 cells treated with Tß4(1-43), Tß4(1-15), Tß4(12-26), Tß4(23-), and untreated control were analyzed by in vitro migration and invasion assay with transwell plate. Cell proliferation assay was conducted to identify the effect of Tß4 and its derived peptide on SKOV3 cell proliferation. The expression of Tß4 related proteins related with cell proliferation was analyzed by Western blot after treatment with Tß4 and its derived peptides. RESULTS: Cell migration and invasion were significantly increased in Tß4 peptide-treated SKOV3 cells compared with untreated control. All three Tß4-derived fragment peptides including those without an actin binding site significantly stimulated migration and invasion of SKOV3 cells. Tß4 and its derived peptide significantly stimulated SKOV3 cell proliferation and up-regulated the expression of RACK-1 protein. CONCLUSIONS: The Tß4 peptide and all of its derived fragment peptides including those without an actin binding motif stimulate migration and invasion of SKOV3 ovarian cancer cells. All peptides significantly increased RACK-1 expression and cell proliferation of SKOV3 cells. These results suggest that Tß4 stimulates migration and invasion of SKOV3 cells by stimulation of cell proliferation through up-regulation of RACK-1 protein.

Comparative efficacy and safety of intravenous ferric carboxymaltose and iron sucrose for iron deficiency anemia in obstetric and gynecologic patients: A systematic review and meta-analysis.

INTRODUCTION: Iron deficiency anemia (IDA) is common among obstetric and gynecologic patients. This systematic review aimed to assess the comparative efficacy and safety of commonly used intravenous (IV) iron formulations, ferric carboxymaltose (FCM), and iron sucrose (IS) in the treatment of IDA in obstetric and gynecologic patients. METHODS: We systematically searched PubMed, EMBASE, Cochrane CENTRAL, and Google Scholar for eligible randomized controlled trials (RCTs) comparing IV iron replacement using FCM and IS up to October 2019. The primary outcome was to compare the efficacy of FCM and IS, assessed by measuring serum hemoglobin (Hb) and ferritin levels before and after iron replacement. The secondary outcome was to compare the safety of FCM and IS, assessed by the incidence of adverse events during iron replacement. The meta-analysis was performed using RevMan 5.3. RESULTS: We identified 9 RCTs with 910 patients (FCM group, n = 456; IS group, n = 454). Before iron replacement, FCM and IS group patients had similar baseline Hb (mean difference [MD], 0.04 g/dL; 95% confidence interval [CI], -0.07 to 015; I2 = 0%; P = 0.48) and ferritin levels (MD, -0.42 ng/mL; 95% CI, -1.61 to 0.78; I2 = 45%; P = 0.49). Following iron replacement, patients who received FCM had higher Hb (MD, 0.67; 95% CI, 0.25-1.08; I2 = 92%; P = 0.002) and ferritin levels (MD, 24.41; 95% CI, 12.06-36.76; I2 = 75%; P = 0.0001) than patients who received IS. FCM group showed a lower incidence of adverse events following iron replacement than IS group (risk ratio, 0.53; 95% CI, 0.35-0.80; I2 = 0%; P = 0.003). Serious adverse events were not reported in any group. CONCLUSION: FCM group showed better efficacy in increasing Hb and ferritin levels and a favorable safety profile with fewer adverse events compared with IS group for IDA treatment among obstetric and gynecologic patients. However, this meta-analysis was limited by the small number of RCTs and high heterogeneity. TRIAL REGISTRATION: The review was prospectively registered with the International Prospective Registry of Systematic Reviews (https://www.crd.york.ac.uk/prospero/, registration number CRD42019148905).

Differential proteome profile of gill and spleen in three pathogen-infected Paralichthys olivaceus.

BACKGROUND: Olive flounder (Paralichthys olivaceus) is one of the major cultured fish species in Asia including Korea. However, the mass mortality of olive flounder caused by various pathogens leads to huge economic loss. The pathogens that lead to fish mortality include parasites, bacteria, and viruses that can cause various kinds of diseases. OBJECTIVE: The purpose of this study was to investigate the protein expression patterns in the gills and spleens of olive flounder after artificial infection. We hypothesized that proteomics levels in gills and spleen may be differentially expressed depending on infectious agents. METHODS: To investigate the expression pattern of proteins in gills and spleens, olive flounders were experimentally infected with VHSV (virus), S. parauberis (bacteria), or M. avidus (pathogenic ciliate). Proteins were extracted from the gills and spleens of infected olive flounder. We used 2-DE analysis with LC-MS/MS to investigate proteome changes in infected olive flounders. RESULTS: The results of the LC-MS/MS analyses showed different protein expression profiles depending on pathogenic sources and target organs. Proteins related to cytoskeletal structure like keratin, calmodulin and actin were mostly expressed in the infected gills. Proteins involved in the metabolism pathway like glycolysis were expressed mainly in the spleens. The protein profiles of S. parauberis and VHSV infection groups had many similarities, but the profile of the M. avidus infection group was greatly different in the gill and spleen. CONCLUSION: Our results indicate that measures according to the characteristics of each pathogen are necessary for disease prevention and treatment of farmed fish.

Human Endogenous Retrovirus (HERV)-K env Gene Knockout Affects Tumorigenic Characteristics of nupr1 Gene in DLD-1 Colorectal Cancer Cells.

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.

Expression profiles of human endogenous retrovirus (HERV)-K and HERV-R Env proteins in various cancers.

The vertebrate genome contains an endogenous retrovirus that has been inherited from the past millions of years. Although approximately 8% of human chromosomal DNA consists of sequences derived from human endogenous retrovirus (HERV) fragments, most of the HERVs are currently inactive and noninfectious due to recombination, deletions, and mutations after insertion into the host genome. Several studies suggested that Human endogenous retroviruses (HERVs) factors are significantly related to certain cancers. However, only limited studies have been conducted to analyze the expression of HERV derived elements at protein levels in certain cancers. Herein, we analyzed the expression profiles of HERV-K envelope (Env) and HERV-R Env proteins in eleven different kinds of cancer tissues. Furthermore, the expression patterns of both protein and correlation with various clinical data in each tissue were analyzed. The expressions of both HERV-K Env and HERV-R Env protein were identified to be significantly high in most of the tumors compared with normal surrounding tissues. Correlations between HERV Env expressions and clinical investigations varied depending on the HERV types and cancers. Overall expression patterns of HERV-K Env and HERV-R Env proteins were different in every individual but a similar pattern of expressions was observed in the same individual. These results demonstrate the expression profiles of HERV-K and HERV-R Env proteins in various cancer tissues and provide a good reference for the association of endogenous retroviral Env proteins in the progression of various cancers. Furthermore, the results elucidate the relationship between HERV-Env expression and the clinical significance of certain cancers. [BMB Reports 2021; 54(7): 368-373].

Analysis of KAP1 expression patterns and human endogenous retrovirus Env proteins in ovarian cancer.

BACKGROUND: Human endogenous retroviruses (HERVs) constitute around 8% of the human genome and have important roles in human health and disease, including cancers. Previous studies showed that HERV envelope (Env) proteins are highly expressed in cancer tissues and co-related with cancer progression. KAP1 has been reported to play a key role in regulating retrotransposons, including HERV-K, through epigenetic silencing. OBJECTIVE: The relationship between KAP-1 and HERV Envs expressions was analyzed only in tumor cell lines and has not yet been studied in cancer tissues. In this study, we analyzed the expression patterns and relationship between KAP1 and HERV Env proteins in ovarian cancer tissues. METHOD: The expression patterns of KAP-1 and HERV Env proteins, including HERV-K and HERV-R, were analyzed in ovarian cancer tissue microarrays that contained 80 surgical specimens, including normal ovary and malignant ovarian cancers. RESULTS: The expression of HERV-R Env and KAP1 proteins is significantly higher in ovarian cancer compared with normal ovary tissues. However, the expression of HERV-K Env did not change significantly in cancer tissues. The expression patterns of HERV-K Env and HERV-R Env significantly increased in early stages of cancer and KAP1 expression was higher in certain stage and types of cancers. However, the expression of HERV-K Env, HERV-R Env, and KAP1 did not change in different age groups. The correlation between the expression of KAP1 and HERV-Env, including HERV-K and HERV-R, was not significantly correlated. CONCLUSIONS: The results of this study showed that there was no significant correlation between the expression of KAP1 and HERV Env proteins in ovarian cancer tissues, unlike studies with cell lines in vitro. These results suggest that the actual expression of HERV Env proteins in ovarian cancer tissues may be regulated through various complex factors as well as KAP1.

Genome based quantification of VHSV in multiple organs of infected olive flounder (Paralichthys olivaceus) using real-time PCR.

BACKGROUND: Viral hemorrhagic septicemia (VHS) is a serious viral disease that infects the olive flounder in South Korea. The Korean aquaculture industry experienced an economic loss caused by the high infectivity and mortality. OBJECTIVE: This study aimed to evaluate the infection density of VHSV in various organs of the olive flounder including spleen, liver, kidney, stomach, esophagus, intestine, gill, muscle, heart, and brain. Olive flounders were collected from a local fish farm and injected subcutaneously with 106 PFU/fish. METHODS: Each 15 fish were sampled at 0, 3, and 7 days post challenge (dpc), respectively, to perform quantitative analysis of VHSV using SYBR-green based real-time PCR in various tissues including spleen, liver, head-kidney, body-kidney, muscle, esophagus, stomach, intestine, gill, and brain. RESULTS: Organs infected with VHSV were obtained after 3 and 7 days. Each organs were examined for viral infection using real-time PCR. The data obtained from this experiment revealed copy numbers higher than 10 copies per 100 ng cDNA in the spleen (15.26 ± 3.11 copies/100 ng of cDNA), muscle (11.24 ± 2.25 copies), and gill (14.23 ± 6.26 copies), but lower in liver, head-kidney, body-kidney, esophagus, brain and stomach. CONCLUSION: The present study, together with previous data, demonstrated that the gill, spleen, and muscle are the major target organs of VHSV in olive flounder. Therefore, central monitoring of spleen, gill and muscle should be considered and might be necessary if anti-VHSV treatment is to be successful in infected olive flounder.

Correlation of long interspersed element-1 open reading frame 1 and c-Met proto-oncogene protein expression in ovarian cancer.

BACKGROUND: Hypomethylation of long interspersed nuclear element-1 (LINE-1) is closely related to certain cancers and concerns with aggressive tumor behavior. Previously, we reported LINE-1 open reading frame-1 (ORF1) protein level was significantly up-regulated in ovarian cancers compared with normal ovary. Hypomethylation of local LINE-1 sequence has been reported to reactivate MET proto-oncogene in colon cancers and hepatocellular carcinoma. However, the relationship between LINE-1 and c-MET expressions in ovarian cancer is not yet studied. METHOD: Here, we analyzed the expression patterns of LINE-1 ORF1 and c-Met protein in ovarian cancer tissue microarrays containing 208 surgical specimens including normal ovary and malignant ovarian cancers. RESULTS: The expressions of both LINE-1 ORF1 and c-Met protein were significantly increased in ovarian cancers and peaked in early stage of tumor. Other clinical data including age and tumor types were not significantly related with both proteins. Co-relationship between LINE-1 ORF1 and c-Met protein was significant (p = 0.03) but several patients show different expression patterns. CONCLUSIONS: These results propose that LINE-1 ORF1 significantly activates c-Met but not in all cases, suggesting other factors may be involved simultaneously.

Induction of Angiogenesis by Malarial Infection through Hypoxia Dependent Manner.

Malarial infection induces tissue hypoxia in the host through destruction of red blood cells. Tissue hypoxia in malarial infection may increase the activity of HIF1α through an intracellular oxygen-sensing pathway. Activation of HIF1α may also induce vascular endothelial growth factor (VEGF) to trigger angiogenesis. To investigate whether malarial infection actually generates hypoxia-induced angiogenesis, we analyzed severity of hypoxia, the expression of hypoxia-related angiogenic factors, and numbers of blood vessels in various tissues infected with Plasmodium berghei. Infection in mice was performed by intraperitoneal injection of 2×106 parasitized red blood cells. After infection, we studied parasitemia and survival. We analyzed hypoxia, numbers of blood vessels, and expression of hypoxia-related angiogenic factors including VEGF and HIF1α. We used Western blot, immunofluorescence, and immunohistochemistry to analyze various tissues from Plasmodium berghei-infected mice. In malaria-infected mice, parasitemia was increased over the duration of infection and directly associated with mortality rate. Expression of VEGF and HIF1α increased with the parasitemia in various tissues. Additionally, numbers of blood vessels significantly increased in each tissue type of the malaria-infected group compared to the uninfected control group. These results suggest that malarial infection in mice activates hypoxia-induced angiogenesis by stimulation of HIF1α and VEGF in various tissues.