• BMB Reports
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• v.41 no.10
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• pp.728-732
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• 2008

FoxO3a is a member of the forkhead box class O (FoxO) transcription factor family and an important regulator of apoptosis. This work aimed to elucidate the involvement of FoxO3a in transforming growth factor-${\beta}1$(TGF-${\beta}1$)-induced apoptosis in FaO rat hepatoma cells. TGF-${\beta}1$ caused a time-dependent activation of FoxO3a and a subsequent increase in FoxO response-element-containing luciferase reporter activity, which was Akt-sensitive. The FaO cells stably transfected with a wild type FoxO3a were more susceptible to the formation of apoptotic bodies, populations of sub-G1 apoptotic cells, and collapse of the mitochondrial-membrane potential triggered by TGF-${\beta}1$. In contrast, transfection with small-interfering RNA (siRNA) oligonucleotide specific for FoxO3a significantly inhibited caspase activation in FaO cells treated with TGF-${\beta}1$. It thus appears that FoxO3a plays a crucial mediatory role in the TGF-${\beta}1$ signaling pathway leading to apoptosis.

• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1790-1794
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• 2012

Recently, it has been suggested that $p27^{Kip1}$, the cell cycle regulatory protein, plays a pivotal role in the progression of normal differentiation in murine embryonic stem (mES) cells. In the current study, we investigated the role of $p27^{Kip1}$ in the regulation of differentiation and apoptotic induction using Western blotting, quantitative real-time RT-PCR, and small interfering RNA (siRNA) assays and confocal laser scanning microscopic analysis of H9 human ES (hES) cells and H9-derived embryoid bodies (EBs) grown for 10 ($EB_{10}$) and 20 days ($EB_{20}$). Our results demonstrate that the proteins $p27^{Kip1}$ and cyclin D3 are strongly associated with cellular differentiation, and, for the first time, show that up-regulation of $p27^{Kip1}$ protects hES cells from inducing differentiation-associated and caspase 3-dependent apoptosis.

• Parasites, Hosts and Diseases
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• v.61 no.4
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• pp.397-404
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• 2023

Acanthamoeba species are free-living amoebae those are widely distributed in the environment. They feed on various microorganisms, including bacteria, fungi, and algae. Although majority of the microbes phagocytosed by Acanthamoeba spp. are digested, some pathogenic bacteria thrive within them. Here, we identified the roles of 3 phagocytosis-associated genes (ACA1_077100, ACA1_175060, and AFD36229.1) in A. castellanii. These 3 genes were upregulated after the ingestion of Escherichia coli. However, after the ingestion of Legionella pneumophila, the expression of these 3 genes was not altered after the consumption of L. pneumophila. Furthermore, A. castellanii transfected with small interfering RNS (siRNA) targeting the 3 phagocytosis-associated genes failed to digest phagocytized E. coli. Silencing of ACA1_077100 disabled phagosome formation in the E. coli-ingesting A. castellanii. Alternatively, silencing of ACA1_175060 enabled phagosome formation; however, phagolysosome formation was inhibited. Moreover, suppression of AFD36229.1 expression prevented E. coli digestion and consequently led to the rupturing of A. castellanii. Our results demonstrated that the ACA1_077100, ACA1_175060, and AFD36229.1 genes of Acanthamoeba played crucial roles not only in the formation of phagosome and phagolysosome but also in the digestion of E. coli.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4775-4778
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• 2013

The key signaling networks regulating cancer cell proliferation remain to be defined. The leucine-rich repeat containing G-protein coupled receptor 48 (GPR48) plays an important role in multiple organ development. In the present study, we investigated whether GPR48 functions in cancer cells using MCF-7, HepG2, NCI-N87 and PC-3 cells. We found that GPR48 overexpression promotes while its knockdown using small interfering RNA oligos inhibits cell proliferation. In addition, Wnt/${\beta}$-catenin signaling was activated in cells overexpressing GPR48. Therefore, our results indicated that GPR48 activates Wnt/${\beta}$-catenin signaling to regulate cancer cell proliferation.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4907-4911
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• 2013

The key signaling networks regulating glioma cell proliferation remain poorly defined. The leucine-rich repeat containing G-protein coupled receptor 4 (Lgr4) has been implicated in intestinal, gastric, and epidermal cell functions. We investigated whether Lgr4 functions in glioma cells and found that Lgr4 expression was significantly increased in glioma tissues. In addition, Lgr4 overexpression promoted while its knockdown using small interfering RNA oligos inhibited glioma cell proliferation. In addition, Wnt/${\beta}$-catenin signaling was activated in cells overexpressing Lgr4. Therefore, our results revealed that Lgr4 activates Wnt/${\beta}$-catenin signaling to regulate glioma cell proliferation.

• BMB Reports
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• v.41 no.10
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• pp.722-727
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• 2008

The present study compared the proteomic characteristics of a low passage number (L-33) and high passage number (H-81) LNCaP cell clone. Marked differences in protein expression were noted in the response of L-33 and H-81 cells to androgens. To investigate if regulation of these proteins was androgen-dependent, expression of the androgen receptor was silenced via small interfering RNA. Consistent with the proteomic data, abrogation of androgen receptor production in H-81 cells resulted in the reversed expression level into L-33 cells compared with non-treated H-81 LNCaP cells. The results clarify the progression into an androgen-independent phenotype.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.685-689
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• 2013

Objective: To study the effects of down-regulation of HDAC6 expression on proliferation, cell cycling and migration of esophageal squamous cell carcinoma (ESCC) cells and related molecular mechanisms. Methods: ESCC cell line EC9706 cells were randomly divided into untreated (with no transfection), control siRNA (transfected with control siRNA) and HDAC6 siRNA (transfected with HDAC6 small interfering RNA) groups. Effects of HDAC6 siRNA interference on expression of HDAC6 mRNA and protein in EC9706 cells were investigated by semi-quantitative RT-PCR, Western blotting and immunocytochemistry methods. Effects of down-regulation of HDAC6 expression on cell proliferation, cell cycle, and cell migration were studied using a CCK-8 kit, flow cytometry and Boyden chambers, respectively. Changes of mRNA and protein expression levels of cell cycle related factor (p21) and cell migration related factor (E-cadherin) were investigated by semi-quantitative RT-PCR and Western blotting methods. Results: After transfection of HDAC6 siRNA, the expression of HDAC6 mRNA and protein in EC9706 cells was significantly downregulated. In the HDAC6 siRNA group, cell proliferation was markedly inhibited, the percentage of cells in G0/G1 phase evidently increased and the percentage of cells in S phase decreased, and the number of migrating cells significantly and obviously decreased. The mRNA and protein expression levels of p21 and E-cadherin in the HDAC6 siRNA group were significantly higher than those in the untreated group and the control siRNA group, respectively. Conclusions: HDAC6 siRNA can effectively downregulate the expression of HDAC6 mRNA and protein in EC9706 cells. Down-regulation of HDAC6 expression can obviously inhibit cell proliferation, arrest cell cycling in the G0/G1 phase and reduce cell migration. The latter two functions may be closely related with the elevation of mRNA and protein expression of p21 and E-cadherin.

• BMB Reports
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• v.45 no.11
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• pp.641-646
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• 2012

It has been reported that ubiquitin-conjugating enzyme 9 (Ubc9), the unique enzyme2 in the sumoylation pathway, is up-regulated in many cancers. However, the expression and regulation of UBC9 in glioma remains unknown. In this study, we found that Ubc9 was up-regulated in glioma tissues and cell lines compared to a normal control. UBC9 knockdown by small interfering RNA (siRNA) affected cell proliferation and apoptosis in T98G cells. Further experiments revealed that microRNA (miR)-214 directly targeted the 3' untranslated region (UTR) of UBC9 and that there was an inverse relationship between the expression levels of miR-214 and UBC9 protein in glioma tissues and cells. miR-214 overexpression suppressed the endogenous UBC9 protein and affected T98G cell proliferation. These findings suggest that miR-214 reduction facilitates UBC9 expression and is involved in the regulation of glioma cell proliferation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5667-5672
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• 2014

Folate receptor alpha ($FR{\alpha}$) mediates folate uptake by endocytosis, and while folate is essential to DNA methylation and synthesis and may have an important role in proliferating cells. $FR{\alpha}$ is known to be expressed in rapidly proliferating cells, including many cancer cell lines, but there has been no systematic assessment of expression in cervical cancer cell lines. The aim of the present study was to evaluate the effects of $FR{\alpha}$ on proliferation and apoptosis of cervical cells and correlation mechanism. In this study, we investigated the biological function of $FR{\alpha}$ in Hela cells using RNA interference. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK8) assay, while cell cycling and apoptosis were assessed by flow cytometry, mRNA levels by real time-PCR and protein levels of $FR{\alpha}$, c-Fos and c-Jun by Western blotting. The results revealed that $FR{\alpha}$ was highly expressed in Hela cells and its silencing with a small interfering RNA (siRNA) inhibited cell proliferation and induced cell apoptosis, arresting the cell cycle in G0/G1 stages while decreasing the proportion in S and G2/M stages, and suppressed the expression levels of c-Fos and c-Jun. In conclusion, the results of this study indicated that $FR{\alpha}$ down-regulation might be capable of suppressing cervical cancer cell proliferation and promoting apoptosis. It suggested that $FR{\alpha}$ might be a novel therapeutic target for cervical cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.1017-1021
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• 2013

The cellular apoptosis susceptibility (CSE1L) gene has been demonstrated to regulate multiple cellular mechanisms including the mitotic spindle check point as well as proliferation and apoptosis. However, the importance of CSE1L in human colon cancer is largely unknown. In the present study, we examined expression levels of CSE1L mRNA by semiquantitative RT-PCR. A lentivirus-mediated small interfering RNA (siRNA) was used to knock down CSE1L expression in the human colon cancer cell line RKO. Changes in CSE1L target gene expression were determined by RT-PCR. Cell proliferation was examined by a high content screening assay. In vitro tumorigenesis was measured by colony-formation assay. Cell cycle distribution and apoptosis were detected by flow cytometric analysis. We found CSE1L mRNA to be expressed in human colon cancer cells. Using a lentivirus based RNAi approach, CSE1L expression was significantly inhibited in RKO cells, causing cell cycle arrest in the G2/M and S phases and a delay in cell proliferation, as well as induction of apoptosis and an inhibition of colony growth capacity. Collectively, the results suggest that silencing of CSE1L may be a potential therapeutic approach for colon cancer.