• Korean Journal of Veterinary Research
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• v.58 no.4
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• pp.201-209
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• 2018

Canine mammary tumors are among the most frequently observed cutaneous tumors in female dogs. Cancer stem cells (CSCs), referred to as tumor-initiating cells, are thought to have properties similar to normal stem cells such as the ability to self-renewal and to differentiate into various cell types. Biological understanding of CSCs and the critical pathways involved in their maintenance are important in research and therapy for mammary tumors. We conducted the present study on sphere formation from REM134 cells by using methylcellulose to produce tumorspheres on a large scale and compared the specific markers of the spheres-formed and plating-cultured REM134 cells. The results revealed that the tumorspheres cultured in methylcellulose had higher seeding density and improved morphology compared to those produced in normal sphere formation medium. Expression levels of stemness markers and CSC-related markers were higher in tumorsphere-forming cells than in plating-cultured cells. Subsequently, we transplanted the tumorsphere-forming and plating-cultured cells into female nude mice to examine their tumorigenic potential. Tumor volume increased rapidly in mice transplanted with tumorsphere-derived cells compared to plating-cultured cells. We observed a novel sphere-forming condition for REM134 cells and showed that REM134 cell tumorspheres can exhibit improved CSC properties.

• BMB Reports
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• v.53 no.12
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• pp.622-627
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• 2020

Cancer stem cells (CSCs) or tumor-initiating cells are thought to play critical roles in tumorigenesis, metastasis, drug resistance, and tumor recurrence. For the diagnosis and targeted therapy of CSCs, the molecular identity of biomarkers or therapeutic targets for CSCs needs to be clarified. In this study, we identified CD166 as a novel marker expressed in the sphere-forming CSC population of A2780 epithelial ovarian cancer cells and primary ovarian cancer cells. The CD166+ cells isolated from A2780 cells and primary ovarian cancer cells highly expressed CSC markers, including ALDH1a1, OCT4, and SOX2, and ABC transporters, which are implicated in the drug resistance of CSCs. The CD166+ cells exhibited enhanced CSC-like properties, such as increased sphere-forming ability, cell migration and adhesion abilities, resistance to conventional anticancer drugs, and high tumorigenic potential in a xenograft mouse model. Knockdown of CD166 expression in the sphere-forming ovarian CSCs abrogated their CSC-like properties. Moreover, silencing of CD166 expression in the sphere-forming CSCs suppressed the phosphorylation of focal adhesion kinase, paxillin, and SRC. These results suggest that CD166 plays a key role in the regulation of CSC-like properties and focal adhesion kinase signaling in ovarian cancer.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.4
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• pp.177-183
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• 2020

The Hippo-YAP signaling pathway is critical for cell proliferation, survival, and self-renewal in both Drosophila and mammals. Disorder of Hippo-YAP pathway leads to tumor development, progression and poor prognosis in various cancers. YAP/TAZ are the key downstream effectors of the Hippo pathway and they can be inhibited through LATS1/2, core kinases in the Hippo pathway, mediated phosphorylation. In this study, we investigated the effect of Angelica gigas Nakai extract (AGNE) on Hippo-YAP/TAZ pathway. First, ANGE induced YAP/TAZ phosphorylation and dissociation of the YAP/TAZ-TEAD transcription complex. By qRT-PCR, we found that ANGE inhibits the expression of YAP/TAZ-TEAD target gene, CTGF and CYR61. In addition, the transcriptional activity of YAP/TAZ was not suppressed significantly in LATS1/2 double-knockout (DKO) cells by ANGE compared to LATS1/2 wild-type (WT) cells, which means AGNE inhibits YAP/TAZ signaling through direct action on LATS1/2. Further, it was confirmed that AGNE-induced activation of LATS1/2 inhibited the migration potential of the vector-expressing cells by suppressing YAP/TAZ activity. The reduced migration potential was restored in active YAP-TEAD expressing cells. Taken together, the results of this study indicate that ANGE downregulates YAP/TAZ signaling in cells through the activation of LATS1/2.

• Molecules and Cells
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• v.45 no.4
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• pp.202-215
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• 2022

The androgen receptor (AR) is an important therapeutic target for treating prostate cancer (PCa). Moreover, there is an increasing need for understanding the AR-independent progression of tumor cells such as neuroendocrine prostate cancer (NEPC). Menin, which is encoded by multiple endocrine neoplasia type 1 (MEN1), serves as a direct link between AR and the mixed-lineage leukemia (MLL) complex in PCa development by activating AR target genes through histone H3 lysine 4 methylation. Although menin is a critical component of AR signaling, its tumorigenic role in AR-independent PCa cells remains unknown. Here, we compared the role of menin in AR-positive and AR-negative PCa cells via RNAi-mediated or pharmacological inhibition of menin. We demonstrated that menin was involved in tumor cell growth and metastasis in PCa cells with low or deficient levels of AR. The inhibition of menin significantly diminished the growth of PCa cells and induced apoptosis, regardless of the presence of AR. Additionally, transcriptome analysis showed that the expression of many metastasis-associated genes was perturbed by menin inhibition in AR-negative DU145 cells. Furthermore, wound-healing assay results showed that menin promoted cell migration in AR-independent cellular contexts. Overall, these findings suggest a critical function of menin in tumorigenesis and provide a rationale for drug development against menin toward targeting high-risk metastatic PCa, especially those independent of AR.

• Molecules and Cells
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• v.45 no.7
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• pp.479-494
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• 2022

Human mesenchymal stem cells (MSCs) are multipotent stem cells that have been intensively studied as therapeutic tools for a variety of disorders. To enhance the efficacy of MSCs, therapeutic genes are introduced using retroviral and lentiviral vectors. However, serious adverse events (SAEs) such as tumorigenesis can be induced by insertional mutagenesis. We generated lentiviral vectors encoding the wild-type herpes simplex virus thymidine kinase (HSV-TK) gene and a gene containing a point mutation that results in an alanine to histidine substitution at residue 168 (TK(A168H)) and transduced expression in MSCs (MSC-TK and MSC-TK(A168H)). Transduction of lentiviral vectors encoding the TK(A168H) mutant did not alter the proliferation capacity, mesodermal differentiation potential, or surface antigenicity of MSCs. The MSC-TK(A168H) cells were genetically stable, as shown by karyotyping. MSC-TK(A168H) responded to ganciclovir (GCV) with an half maximal inhibitory concentration (IC₅₀) value 10-fold less than that of MSC-TK. Because MSC-TK(A168H) cells were found to be non-tumorigenic, a U87-TK(A168H) subcutaneous tumor was used as a SAE-like condition and we evaluated the effect of valganciclovir (vGCV), an oral prodrug for GCV. U87-TK(A168H) tumors were more efficiently ablated by 200 mg/kg vGCV than U87-TK tumors. These results indicate that MSC-TK(A168H) cells appear to be pre-clinically safe for therapeutic use. We propose that genetic modification with HSV-TK(A168H) makes allogeneic MSC-based ex vivo therapy safer by eliminating transplanted cells during SAEs such as uncontrolled cell proliferation.

• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.844-854
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• 2022

Helicobacter pylori, a group 1 carcinogen, colonizes the stomach and affects the development of stomach diseases. Progranulin (PGRN) is an autocrine growth factor that regulates multiple cellular processes and plays a tumorigenic role in many tissues. Nevertheless, the mechanism of action of PGRN in gastric cancer caused by H. pylori infection remains unclear. Here, we investigated the role of PGRN in cell cycle progression and the cell proliferation induced by H. pylori infection. We found that the increased PGRN was positively associated with CDK4 expression in gastric cancer tissue. PGRN was upregulated by H. pylori infection, thereby promoting cell proliferation, and that enhanced level of proliferation was reduced by PGRN inhibitor. CDK4, a target gene of PGRN, is a cyclin-dependent kinase that binds to cyclin D to promote cell cycle progression, which was upregulated by H. pylori infection. We also showed that knockdown of CDK4 reduced the higher cell cycle progression caused by upregulated PGRN. Moreover, when the PI3K/Akt signaling pathway (which is promoted by PGRN) was blocked, the upregulation of CDK4 mediated by PGRN was reduced. These results reveal the potential mechanism by which PGRN plays a major role through CDK4 in the pathological mechanism of H. pylori infection.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.155-160
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• 2013

Objectives : Gastric cancer is a leading cause of cancer-related deaths, worldwide. Houttuynia cordata Thunberg (H. cordata) has been used as a medicinal plants and it has an anti-cancer activity in human colorectal cancer and leukemic cancer. However, the potential anti-cancer activity and mechanisms of H. cordata for human gastric cancer cells have not been tested so far. Thus, this study examined the biological effects of H. cordata on the human gastric cancer cell line SNU-1 and AGS. Methods : Inhibition of cell proliferation and cell cycle by H. cordata was carried out by MTT assay and Muse cell cycle analysis and the expressions of protein associated with apoptosis and cell cycle regulation were investigated with Western blot analysis. Results : In MTT assay, the proliferation of SNU-1 and AGS cells was significantly inhibited by H. cordata in a time and dose dependent manner, Inhibition of cell proliferation by H. cordata was in part associated with apoptotic cell death, as shown by changes in the expression ratio of Bax to Bcl-2 by H. cordata. Also, H. cordata regulated the expression of cell cycle regulatory proteins such as pRb, cyclin D1, cyclin E, CDK4, CDK2, p21 and p15. Conclusion : The antiproliferative effect of H. cordata on SNU-1 and AGS gastric cancer cells revealed in this study suggests that H. cordata has intriguing potential as a chemopreventive or chemotherapeutic agent.

• Molecules and Cells
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• v.45 no.8
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• pp.550-563
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• 2022

Hepatocellular carcinoma (HCC) is an aggressive and incurable cancer. Although understanding of the molecular pathogenesis of HCC has greatly advanced, therapeutic options for the disease remain limited. In this study, we demonstrated that SETD5 expression is positively associated with poor prognosis of HCC and that SETD5 depletion decreased HCC cell proliferation and invasion while inducing cell death. Transcriptome analysis revealed that SETD5 loss downregulated the interferon-mediated inflammatory response in HCC cells. In addition, SETD5 depletion downregulated the expression of a critical glycolysis gene, PKM (pyruvate kinase M1/2), and decreased glycolysis activity in HCC cells. Finally, SETD5 knockdown inhibited tumor growth in xenograft mouse models. These results collectively suggest that SETD5 is involved in the tumorigenic features of HCC cells and that targeting SETD5 may suppress HCC progression.

• Journal of Digestive Cancer Research
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• v.4 no.1
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• pp.1-9
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• 2016

The abundance of multi-drug resistance ATPase binding cassette and deranged self-renewal pathways shown in cancer stem cells (CSCs) played a crucial role in tumorigenesis, tumor resistance, tumor recurrence, and tumor metastasis. Therefore, elucidation of CSCs biology can improve diagnosis, enable targeted treatment, and guide the follow up of GI cancer patients. In order to achieve chemoquiescence, seizing cancer through complete ablation of CSCs, CSCs are rational targets for the design of interventions that will enhance responsiveness to traditional therapeutic strategies and contribute in the prevention of local recurrence as well as metastasis. However, current cancer treatment strategies fail to either detect or differentiate the CSCs from their non-tumorigenic progenies mostly due to the absence of specific biomarkers and potent agents to kill CSCs. Recent advances in knowledge of CSCs enable to produce several candidates to ablate CSCs in gastrointestinal (GI) cancers, especially cancers originated from inflammation-driven mutagenesis such as Barrett's esophagus (BE), Helicobacter pylori-associated gastric cancer, and colitis-associated cancer (CAC). Our research teams elucidated through revisiting old drugs that proton pump inhibitor (PPI) and potassium competitive acid blocker (p-CAB) beyond authentic acid suppression, chloroquine for autophage inhibition, sonic hedgehog (SHH) inhibitors, and Wnt/β-catenin/NOTCH inhibitor can ablate CSCs specifically and efficiently. Furthermore, nanoformulations of these molecules could provide an additional advantage for more selective targeting of the pathways existing in CSCs just like current molecular targeted therapeutics and sustained action, while normal stem cells intact. In this review article, the novel approach specifically to ablate CSCs existing in GI cancers will be introduced with the introduction of explored mode of action.

• IMMUNE NETWORK
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• v.21 no.4
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• pp.30.1-30.12
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• 2021

High expression of mitofusin-2 (MFN2), a mitochondrial fusion protein, has been frequently associated with poor prognosis of patients with cervical cancer. Here, we aimed to identify the function of MFN2 in cervical cancer to understand its influence on disease prognosis. To this end, from cervical adenocarcinoma, we performed an MTT assay and quantitative RT-PCR (qRT-PCR) analysis to assess the effects of MFN2 on the proliferation and of HeLa cells. Then, colony-formation ability and tumorigenesis were evaluated using a tumor xenograft mouse model. The migration ability related to MFN2 was also measured using a wound healing assay. Consequently, epithelial-mesenchymal transition (EMT) of MFN2-knockdowned HeLa cells originating from adenocarcinoma. markers related to MFN2 were assessed by qRT-PCR. Clinical data were analyzed using cBioPortal and The Cancer Genome Atlas. We found that MFN2 knockdown reduced the proliferation, colony formation ability, migration, and in vivo tumorigenesis of HeLa cells. Primarily, migration of MFN2-knockdowned HeLa cells decreased through the suppression of EMT. Thus, we concluded that MFN2 facilitates cancer progression and in vivo tumorigenesis in HeLa cells. These findings suggest that MFN2 could be a novel target to regulate the EMT program and tumorigenic potential in HeLa cells and might serve as a therapeutic target for cervical cancer. Taken together, this study is expected to contribute to the treatment of patients with cervical cancer.