• Molecules and Cells
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• 제38권4호
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• pp.327-335
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• 2015

Piperlongumine, a natural alkaloid isolated from the long pepper, selectively increases reactive oxygen species production and apoptotic cell death in cancer cells but not in normal cells. However, the molecular mechanism underlying piperlongumine-induced selective killing of cancer cells remains unclear. In the present study, we observed that human breast cancer MCF-7 cells are sensitive to piperlongumine-induced apoptosis relative to human MCF-10A breast epithelial cells. Interestingly, this opposing effect of piperlongumine appears to be mediated by heme oxygenase-1 (HO-1). Piperlongumine upregulated HO-1 expression through the activation of nuclear factor-erythroid-2-related factor-2 (Nrf2) signaling in both MCF-7 and MCF-10A cells. However, knockdown of HO-1 expression and pharmacological inhibition of its activity abolished the ability of piperlongumine to induce apoptosis in MCF-7 cells, whereas those promoted apoptosis in MCF-10A cells, indicating that HO-1 has anti-tumor functions in cancer cells but cytoprotective functions in normal cells. Moreover, it was found that piperlongumine-induced Nrf2 activation, HO-1 expression and cancer cell apoptosis are not dependent on the generation of reactive oxygen species. Instead, piperlongumine, which bears electrophilic ${\alpha},{\beta}$-unsaturated carbonyl groups, appears to inactivate Kelch-like ECH-associated protein-1 (Keap1) through thiol modification, thereby activating the Nrf2/HO-1 pathway and subsequently upregulating HO-1 expression, which accounts for piperlongumine-induced apoptosis in cancer cells. Taken together, these findings suggest that direct interaction of piperlongumine with Keap1 leads to the upregulation of Nrf2-mediated HO-1 expression, and HO-1 determines the differential response of breast normal cells and cancer cells to piperlongumine.

• Journal of Korean Neurosurgical Society
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• 제30권11호
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• pp.1324-1327
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• 2001

Radiation is a common treatment modality for central nervous system neoplasms. However, secondary tumor development must be considered in the differential diagnosis in patients with new or recurring symptoms after treatment with conventional radiotherapy. A 28-year-old woman developed a cavernous hemangioma about 9 years after brain irradiation for astrocytoma. Clinical and histopathological details are presented, and previous reports of radiation-induced intracranial cavernous hemangioma are reviewed.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6649-6655
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• 2014

Radiation therapy is an important treatment for head and neck squamous cell carcinoma (HNSCC). However, how to promote radiation sensitivity in HNSCC remains a challenge. This study aimed to investigate the radiosensitizing effects of fenofibrate on HNSCC and explore the underlying mechanisms. HNSCC cell lines CNE-2 and KB were subjected to ionizing radiation (IR), in the presence or absence of fenofibrate treatment. Cell growth and survival, apoptosis and cell cycle were evaluated. In addition, CNE-2 cells were xenografted into nude mice and subjected to IR and/or fenofibrate treatment. The expression of cyclinB and CDK1 was detected by Western blotting. Our results showed that fenofibrate efficiently radiosensitized HNSCC cells and xenografts in mice, and induced apoptosis and G2/M arrest via reducing the activity of the CDK1/cyclinB1 kinase complex. These data suggest that fenofibrate could be a promising radiosensitizer for HNSCC radiotherapy.

• Radiation Oncology Journal
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• 제16권2호
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• pp.91-98
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• 1998

목적 : SCK 선암 세포주에서 방사선 조사에 의해 일어나는 apoptosis와 세포 주기와의 연관성을 규명하고자하였다. 대상 및 방법 : SCK 선암 세포주를 apoptosis의 통상적인 정성 분석 방법인 agarose gel electrophoresis 방법을 이용하여 방사선 조사량과 배지 pH 환경과의 연구에서 2-l2Gy의 방사선 조사량과 pH 7.5 및 5.6의 배양 배자 조건하에서 다양한 배양 시간의 경과에 따른 DNA fragmentation의 지표인 laddering을 관찰하였다. 실험 조작으로 apoptosis가 유발된 세포군을 정량적으로 분석하고 세포 주기 분석을 위해 FACScan을 이용하였다. 결과 : apoptosis가 왕성히 발현되었던 pH 7.5 배지에서 배양하였던 세포에서는 방사선 조사직후부터 $G_2M$ phase의 세포들의 분획이 증가하기 시작하여 12시간째 약 $70\%$까지의 최고치를 보인 후 36시간째에 방사선을 조사하지 않았던 상태의 분획으로 정상화되었다. 하지만 pH 6.6 배지에서 배양하였던 세포에서의 $G_2/M$ phase의 세포들의 분획의 증가는 pH 7.5 배지에서 배양하였던 세포들에 비해 비교적 천천히 일어나고 그 최고치도 24시간째에 약 $45\%$로 관찰되었다. 특이한 것은 $G_2/M$ phase의 세포들의 분획이 그 이후 감소되는 정도가 pH 7.5 배지에서 배양하였던 세포들에 비해 미약하여 48시간 배양 이후에도 약 $30-35\%$의 세포는 $G_2/M$ Phase의 세포들의 분획으로 관찰되었다. 결론 : 연구자들은 이러한 현상이 세포들이 GJM phase에서 많은 양의 세포들이 집적되어 세포주기를 순환하지 못하는 $G_2M$ arrest 현상으로 이해하였다. 세포 내외의 산성환경 상태에서 방사선을 조사 받은 SCK 종양세포는 $G_2/M$ arrest 상태가 지속되며 이는 post-mitotic apoptosis를 억제한다고 추론하였다.

• 환경생물
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• 제22권4호
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• pp.543-549
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• 2004

Ixeris dentata is a typical oriental herb. It is a widely distributed perennial in Korea, Japan and China, which belongs to the Compositae Family. The whole plant of I. dentata has been used for the treatment of pneumonia, contusion, tumor and hepatitis. It has also been used for the treatment of allergic diseases as a folk therapy in Korea. I. dentata is known to have aliphatics, triterpenoids and sesquiterpene glycosides in its composition. The present study was designed to explore the protective effects of water- and ethanol- extracts from I. dentata on irradiated rodents. For oral administration (twice per day), the extractive powder of I. dentata and the positive control (ascorbic acid) were dissolved at a concentration of 0.5 and 250mg $ml^{-1}$ in saline, respectively. Thirty days after irradiation, the ratio of the weight of the testis to the body weight was lower than 50% in the radiation groups than the control group. The ALP concentrations in the group treated with the water-extracts of the leaf were $79.68\pm{1.39%}$ (p<0.05) of those of the radiation control. Both of the SGOT and SGPT in the group treated with the ethanol-extract of the root were $72.68\pm{0.95}\;and\;77.87\pm{5.74}$ (p<0.05) of those of the radiation control, respectively. The levels of DNA damage induced by gamma radiation decreased in the experimental group to which the extracts of I. dentata were administered before irradiation. In conclusion, these results indicate that the extracts of I. dentata have an excellent ability to reduce the radicals and they have a protective effect on DNA breakage caused by radiation.

• Radiation Oncology Journal
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• 제7권1호
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• pp.1-13
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• 1989

Effects of ionizing radiation alone and combined with chemotherapy on tumor growth and it's clonal specificity monitored by changes in distribution of chromosome number were studies in A549 ceil line originated from human adenocarcinoma of the lung. Radiation (300 rad, 600 rad and 900 rad) were delivered with or without 5-FU. Forty eight hours later, 57.5% of growth inhibition of cell w8s seen in cells treated with 5-FU concentration of $0.4{\mu}g/ml$ for 24hr exposure. Cell survival curves after radiation with and without 5-FU were made. Chromosomal analysis of cells in metaphase in control, and in cells treated with 300 rad of radiation, or $0.4{\mu}g/ml$ of 5-FU treatment, and combined treatment of both were done to examine the changes in ploidy and number of chromosome. Radiation combined with S-FU enhanced growth inhibition of A549 cells. However, no evidence of synergegic effects in growth. inhibition was observed in the cells treated with the combination therapy. Pattern of chromosomal distribution of survived cells were shifted from hyperploidy to hypoploidy by single dose of radiation (300 rad). As radiation dose increased a large number of hypoploidy cells were observed. Following treatment of cells with 5-FU, chomosomal distribution of survived cells were also shifted to hypodiploidy which were seen in cells treated with radiation, The ceil treated with 5-FU and fellowed by radiation within 24 hrs had cell with increased number of hypodiploidy cells. Almost same type of chromosomal changes were reproduced in cells treated with combined treatment with radiation and 5-FU. Minor differences were that cells with fewer number of chromosome were more frequent in cells treated with combined therapy. Further increase in cells of hypoploidy (93%) having 1-10 chromosome were induced by additional radiation. Therefore, the enhanced therapeutic effect of 5-FU combined with radiation of A549 cells appeared to be additive rather than synergistic.

• Asian Pacific Journal of Cancer Prevention
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• 제14권2호
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• pp.1077-1082
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• 2013

Background: Renal cell carcinoma (RCC) is a malignancy with a poor prognosis. We aimed to explore whether the expression of Long Non-Coding RNA (LncRNA) growth arrest-specific transcript 5 (GAS5) is associated with RCC genesis. Methods: We selected twelve clinical samples diagnosed for renal clear cell carcinoma and found that the LncRNA GAS5 transcript levels were significantly reduced relative to those in adjacent unaffected normal renal tissues. Results: In addition, expression of GAS5 was lower in the RCC cell line A498 than that in normal renal cell line HK-2. Furthermore, using functional expression cloning, we found that overexpression of GAS5 in A498 cells inhibited cell proliferation, induced cell apoptosis and arrested cell cycling. At the same time, the migration and invasion potential of A498 cells were inhibited compared to control groups. Conclusion: Our study provided the first evidence that a decrease in GAS5 expression is associated with RCC genesis and progression and overexpression of GAS5 can act as a tumor suppressor for RCC, providing a potential attractive therapeutic approach for this malignancy.

• Radiation Oncology Journal
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• 제21권3호
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• pp.207-215
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• 2003

목적: Extracellular signal-regulated kinase (ERK)는 mitogen-activated protein kinase cascade의 일원으로 다양한 세포독성 자극에 의해 유도되는 apoptosis에 반대되는 역할을 한다. 따라서 ERK의 억제는 항암제로서 유용하게 사용될 것으로 생각되어진다. 대상 및 방법: 마우스 간암인 HCa-I는 TCD50가 80 Gy 이상으로 강한 방사선 내성종양으로 알려져 있으며, 방사선 민감성의 증진을 위해 다양한 항암제가 실험되었으나 뚜렷한 효과를 나타내지 못했다. 이 실험을 통해 in vivo,, 특히 방사선 내성종양에서 ERK의 억제가 방사선에 의한 항암 작용을 증진시키는지 알아보고자 하였다. C3H/HeJ 마우스에 종양의 크기가 $7.5\~8\;mm$가 되었을 때 PD98059 ($0.16\;\mug/50\;\mul$로 종양에 직접 주사)를 처리하였다. 결과: 처리 1시간째에 p-ERK가 0.5배로 억제되었다. 종양 성장 지연 분석에서 증강 지수가 전 처리군과 후 처리군에서 각각 1.6과 1.87로 PD98059가 종양의 방사선 감수성을 증가시키는 것으로 관찰되었다. 25 Gy 방사선과 PD98059 복합처리 시 apoptosis가 크게 증가되었다. 각 실험군의 apoptosis 최대치는 방사선 조사군에서 $1.4\%$, PD98059 처리군에서 $0.9\%$ 복합처리군의 전 처리군과 후 처리군에서 각각 $4.9\%\;5.3\%$를 나타냈다. Apoptosis 조절 물질의 변화는, p53의 발현이 복합 처리군에서 PD98059 전 처리군과 후 처리군 모두에서 24시간까지 대조군에 비해 2.7배, 3.2배의 높은 발현 수준을 유지하여 처리 1시간째부터 발현 증가를 하여 24시간까지 지속되는 것이 관찰되었다. $p21^{WAF1/CIP1}$의 발현은 p53 발현 변화와 유사한 양상으로 특히 PD98059 후 처리군에서 방사선 조사군이나 PD98059 전 처리군과 비교하여 높은 발현수준을 보였으며, 24시간까지 3.2배의 높은 발현 수준을 유지하는 것으로 나타났다. Bcl-Xs는 25 Gy 방사선 조사군이나 PD98059 처리군에서는 뚜렷한 변화를 보이지 않았으나 복합 처리군중 전 처리군에서 4시간 째 대조군에 비해 1.93배 증가를 보였으며, 후 처리군에서는 1시간 후에 1.83배의 증가를 보였다. 모든 실험군에서 Bcl-2, $Bcl-X_L$, BaX는 뚜렷한 발현 변화를 보이지 않았다. 결론: 방사선 내성 종양인 간암에 MEK 억제제를 방사선 조사와 복합 처리하여 방사선 감수성을 향상시켜 치료 효율의 상승을 유도 할 수 있을 것으로 생각된다.

• Radiation Oncology Journal
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• 제29권3호
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• pp.147-155
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• 2011

Purpose: This study was designed to determine the influencing factors and clinical course of pathologically proven cases of radiation-induced brain injury (RIBI). Materials and Methods: The pathologic records of twelve patients were reviewed; these patients underwent surgery following radiotherapy due to disease progression found by follow-up imaging. However, they were finally diagnosed with RIBI. All patients had been treated with 3-dimensional conventional fractionated radiotherapy and/or radiosurgery for primary or metastatic brain tumors with or without chemotherapy. The histological distribution was as follows: two falx meningioma, six glioblastoma multiform (GBM), two anaplastic oligodendroglioma, one low grade oligodendroglioma, and one small cell lung cancer with brain metastasis. Results: Radiation necrosis was noted in eight patients and the remaining four were diagnosed with radiation change. Gender (p = 0.061) and biologically equivalent dose $(BED)_3$ (p = 0.084) were the only marginally influencing factors of radiation necrosis. Median time to RIBI was 7.3 months (range, 0.5 to 61 months). Three prolonged survivors with GBM were observed. In the subgroup analysis of high grade gliomas, RIBI that developed <6 months after radiotherapy was associated with inferior overall survival rates compared to cases of RIBI that occurred ${\geq}6$ months (p = 0.085). Conclusion: Our study demonstrated that RIBI could occur in early periods after conventional fractionated brain radiotherapy within normal tolerable dose ranges. Studies with a larger number of patients are required to identify the strong influencing factors for RIBI development.

• 대한두경부종양학회지
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• 제29권2호
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• pp.41-47
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• 2013

Background : The purpose of this study is to review our experience with the variable applications of the facial artery muscolomucosal(FAMM) flap for oral cavity reconstruction following treatment for head and neck malignancies. Methods : We performed retrospect medical record review from January 2012 to June 2013. This flap technique was applied in 3 patients to reconstruct the defects of oral cavity induced by treatment for head and neck malignancies. Results : The defects and fibrosis occurred due to variable causes related to previous treatment for head and neck malignancies such as tumor resection and chemoradiation. Two patient suffered from defect on hard and soft palate and one patient suffered from trismus related to fibrotic scar band. We performed oral cavity reconstruction using FAMM flap even though these all patients had history of neck dissection surgery or radiation therapy. Conclusion : FAMM flap is an ideal option for reconstruction following treatment not only for primary tumor resection but also for defects induced by variable causes. Preoperative radiation and neck dissection surgery, which are previously considered as some challenges, are no longer contraindication in our cases.