• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2095-2100
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• 2012

Sulforaphane (SFN) an isothiocyanate formed by hydrolysis of glucosinolates found in Brassica oleraceae is reported to possess anticancer and antioxidant activities. In this study, we isolated SFN from red cabbage (Brassica oleraceae var rubra) and evaluated the comparative antiproliferative activity of various fractions (standard SFN, extract and purified SFN) by MTT assay in human epithelial carcinoma HEp -2 and and Vero cells. Probable apoptotic mechanisms mediated through p53, bax and bcl-2 were also examined. The SFN fraction was collected by HPLC, enriched for its SFN content and confirmed. Expression of apoptosis-related proteins was detected by western blotting and RT PCR. Results showed that Std SFN and purified SFN concentration found to have closer $IC_{50}$ which is equal to 58.96 microgram/ml (HEp-2 cells), 61.2 microgram/ml (Vero cells) and less than the extract which is found to be 113 microgram/ml (HEp-2 cells) and 125 microgram/ml (Vero cells). Further studies on apoptotic mechanisms showed that purified SFN down-regulated the expression of bcl-2 (antiapoptotic), while up-regulating p53 and Bax (proapoptotic) proteins, as well as caspase-3. This study indicates that purified SFN possesses antiproliferative effects the same as Std SFN and its apoptotic mechanism in HEp-2 cells could be mediated through p53 induction, bax and bcl-2 signaling pathways.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1079-1085
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• 2008

The chemopreventive activity of sulforaphane (SFN) occurs through its inhibition of carcinogen-activating enzymes and its induction of detoxification enzymes. However, the exact mechanisms by which SFN exerts its anti-carcinogenic effects are not fully understood. Therefore, the mechanisms underlying the cytoprotective effects of SFN were examined in MCF-7 breast cancer cells. Exposure of cells to SFN (10 ${\mu}M$) induced a transcriptional change in the AKR1C3 gene, which is one of aldo-keto reductases (AKRs) family that is associated with detoxification and antioxidant response. Further analysis revealed that SFN elicited a dose- and time-dependent increase in the expression of both the NRF2 and AKR1C3 proteins. Moreover, this up-regulation of AKR1C3 was inhibited by pretreatment with antioxidant, N-acetyl-L-cysteine (NAC), which suggests that the up-regulation of AKR1C3 expression induced by SFN involves reactive oxygen species (ROS) signaling. Furthermore, pretreatment of cells with LY294002, a pharmacologic inhibitor of phosphatidylinositol 3-kinase (PI3K), suppressed the SFN-augmented Nrf2 activation and AKR1C3 expression; however, inhibition of PKC or MEK1/2 signaling with $G\ddot{o}6976$ or PD98059, respectively, did not alter SFN-induced AKR1C3 expression. Collectively, these data suggest that SFN can modulate the expression of the AKR1C3 in MCF-7 cells by activation of PI3K via the generation of ROS.

• Journal of Life Science
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• v.21 no.6
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• pp.851-857
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• 2011

Sulforaphane (SFN) is an isothiocyanate, isolated from glucoraphanin in broccoli and other cruciferaous vegetables. Recent studies have revealed that SFN induces anti-proliferation and apoptosis by cell cycle arrest in various cancer cells. In this study, we investigated the effect of SFN induced apoptosis in chondrosarcoma HTB-94 cells. SFN caused suppression of proliferation and apoptosis in a dose-dependent manner as determined by cell phenotype, MTT assay and FACS analysis in HTB-94 cells. Treatment of SFN led to caspase-3 activation and p53 accumulation as determined by Western blot analysis. Also, SFN significantly induced DNA fragmentation and nuclear degradation though activation of caspase-3, as detected by DNA electrophoresis and immunostaining, respectively. Our results indicate that SFN-induced apoptosis was regulated by p53 and caspase-3 dependent pathways. Furthermore, SFN may act as a potent anti-proliferation agent, and as a promising candidate for molecular-targeting chemotherapy against human chondrosarcoma cells.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2004.11a
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• pp.53-60
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• 2004

The pro-apoptotic effect of phenethyl isothiocyanate (PEITC) and the role of glutathione (GSH) in sulforaphane (SFN)-induced antioxidant response element-dependent gene expression were investigated. The caspase-3 and caspase-9 activities were stimulated by PEITC. The release of cytochrome c was time- and dose- dependent. SP600125 suppressed apoptosis induced by PEITC. Similarly, this JNK inhibitor attenuated both cytochrome c release and caspase-3 activation induced by PEITC. SFN is converted to the glutathione conjugate by glutathione S-transferases (GSTs). It was accumulated in mammalian cells by up to several hundred-fold over the extracellular concentration, by conjugation with intracellular GSH. The induction of ARE by SFN was 8.6-fold higher than by SFN-NAC. The decrease in ARE expression at higher concentrations of SFN and SFN-NAC was correlated with the accelerated apoptotic cell death, with a dose-dependent activation of caspase 3 activity by SFN. Upon addition of extracellular GSH within 6 hr of treatment with SFN, the effect on ARE expression was blocked almost completely.

• Journal of Broadcast Engineering
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• v.21 no.4
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• pp.552-561
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• 2016

In OFDM system, frequency-domain sub-carriers of a symbol generally consist of data sub-carriers and scattered pilot sub-carriers and in the receiver, channel is estimated through time-axis interpolating pilot sub-carriers of several OFDM symbols. However, time-axis interpolation fails to keep track of rapid channel variation caused by fast moving receiver. Although symbol by symbol channel estimation without time-axis interpolation enables fast estimation, the performance is severely degraded for a long delay spread channel in a single frequency networks (SFNs) because of insufficient pilot sub-carriers. In this paper, a channel estimation scheme for OFDM receiver in a fast mobile SFN channel is proposed. The proposed scheme is applied to DVB-T receiver to improve the Doppler mobile performance in SFN channel.

• Electronics and Telecommunications Trends
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• v.19 no.4 s.88
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• pp.1-9
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• 2004

본 고에서는 미국식(ATSC) 지상파 디지털 TV 방송을 단일 주파수 망(SFN)을 통해 서비스하기 위해 필요한 기술적인 사항에 대하여 고찰하고, ATSC 방송 방식에서 SFN을 구성하기 위한 방법을 제안한다. SFN구성은 방송 주파수의 이용 효율을 높이고, 방송 구역 내에서 안정적인 전파 세기를 보장한다. 이러한 SFN 구성을 위한 기술은 복수 개의 송신기를 이용하는 방법(DTX)과 복수 개의 디지털 동일 채널 중계기(DOCR)를 이용하는 방법으로 나뉘어진다. ATSC 방식에서는 두 가지 방법 모두 사용하여 SFN 구성이 가능하나, 복수 개의 송신기를 이용하는 방법은 현재의 기술 기준을 변경해야 한다는 제약이 따른다. 반면 다수 개의 DOCR를 이용하는 방법은 기존의 송신기와 함께 SFN 구성이 가능하여 망 구성이 용이하다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.737-740
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• 2003

SFN (Single Frequency Network) and OCR (On Channel Repeater) are often considered for the efficiency of frequency allotment in digital TV. In this paper, we discuss the performance and evaluate some coverage criterions for SFN and OCR. Also, we propose MATLAB simulator for coverage planning and estimation.

• Journal of Electrodiagnosis and Neuromuscular Diseases
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• v.20 no.2
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• pp.77-83
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• 2018

Small fiber neuropathy (SFN) mainly affects thinly myelinated $A{\delta}$-fibers and unmyelinated C-fibers presented with neuropathic pain like burning feet or numbness. Many conditions are known as a causes of SFN, metabolic derangement, especially glucose intolerance, is the most frequent cause of SFN. It has been hard to diagnose SFN because there has been lack of specialized test for small nerve fiber. Quantification of intraepidermal nerve fiber density using skin biopsy is promising method to diagnose SFN. A skin biopsy also could give helps to research pathophysiology of SFN by specialized stain method.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5855-5860
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• 2013

Phytochemicals are among the natural chemopreventive agents with most potential for delaying, blocking or reversing the initiation and promotional events of carcinogenesis. They therefore offer cancer treatment strategies to reduce cancer related death. One such promising chemopreventive agent which has attracted considerable attention is sulforaphane (SFN), which exhibits anti-cancer, anti-diabetic, and anti-microbial properties. The present study was undertaken to assess effect of SFN alone and in combination with a chemotherapeutic agent, gemcitabine, on the proliferative potential of MCF-7 cells by cell viability assay and authenticated the results by nuclear morphological examination. Further we analyzed the modulation of expression of Bcl-2 and COX-2 on treatment of these cells with SFN by RT-PCR. SFN showed cytotoxic effects on MCF-7 cells in a dose- and time-dependent manner via an apoptotic mode of cell death. In addition, a combinational treatment of SFN and gemcitabine on MCF-7 cells resulted in growth inhibition in a synergistic manner with a combination index (CI)<1. Notably, SFN was found to significantly downregulate the expression of Bcl-2, an anti-apoptotic gene, and COX-2, a gene involved in inflammation, in a time-dependent manner. These results indicate that SFN induces apoptosis and anti-inflammatory effects on MCF-7 cells via downregulation of Bcl-2 and COX-2 respectively. The combination of SFN and gemcitabine may potentiate the efficacy of gemcitabine and minimize the toxicity to normal cells. Taken together, SFN may be a potent anti-cancer agent for breast cancer treatment.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.241-247
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• 2015

Ultraviolet (UV) radiation-induced loss of dermal extracellular matrix is associated with skin photoaging. Recent studies demonstrated that keratinocyte-releasable stratifin (SFN) plays a critical role in skin collagen metabolism by inducing matrix metalloproteinase 1 (MMP1) expression in target fibroblasts. In the present study, we examined whether SFN released from UVB-irradiated epidermal keratinocytes increases MMP1 release from dermal fibroblasts, and whether these events are affected by p-coumaric acid (p-CA), a natural phenolic compound with UVB-shielding and antioxidant properties. HaCaT cells were exposed to UVB in the absence and presence of p-CA, and the conditioned medium was used to stimulate fibroblasts in medium transfer experiments. The cells and media were analyzed to determine the expressions/releases of SFN and MMP1. UVB exposure increased SFN release from keratinocytes into the medium. The conditioned medium of UVB-irradiated keratinocytes increased MMP1 release from fibroblasts. The depletion of SFN using a siRNA rendered the conditioned medium of UVB-irradiated keratinocytes ineffective at stimulating fibroblasts to release MMP1. p-CA mitigated UVB-induced SFN expression in keratinocytes, and attenuated the MMP1 release by fibroblasts in medium transfer experiments. In conclusion, the present study demonstrated that the use of UV absorbers such as p-CA would reduce UV-induced SFN-centered signaling events involved in skin photoaging.