• The Journal of Internal Korean Medicine
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• v.25 no.4
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• pp.324-336
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• 2004

Objectives : The purpose of this investigation is to evaluate the effects of Scutellaria baicalensis GEORGI on alteration in gene expression in a hypoxia model using cultured rat cortical cells. Methods : E18 rat cortical cells were grown in a Neurobasal medium containing B27 supplement. On 12 DIV, Scutellaria baicalensis GEORGI(20 ug/ml) was added to the culture media and left for 24 hrs. On 11 DIV, cells were given a hypoxic insult $(2%\;O_2/5%\;CO_2,\;37^{\circ}C,\;3\;hrs)$, returned to normoxia and cultured for another 24 hrs. Total RNA was prepared from Scutellaria baicalensis GEORGI-untreated (control) and -treated cultures and alteration in gene expression was analysed by microarray using rat 5K-TwinChips. Results : For most of the genes altered in expression, the Global M values were between -0.5 to +0.5. Among these, 1143 genes increased in their expression by more than Global M +0.1, while 1161 genes decreased by more than Global M -0.1. Effects on some of the genes whose functions are implicated in neural viability are as follows: 1) The expression of apoptosis-related genes such as Bad (Global M = 0.39), programmed cell death-2(Pdcd2) (Global M = 0.20) increased, while Purinergic receptor P2X(P2rxl) Global M = -0.22), Bc12-like1(Bc1211)(Global M = -0.19) decreased. 2) The expression of 'response to stress-related genes such as antioxidation-related AMP-activated protein kinase subunit gamma 1 gene (Prkag1) (Global M = 0.14), catalase gene (Global M = 0.14) and Heme Oxygenase(Hmoxl) increased. 3) The expression of Fos like antigen 2 (Fos12) expressed in neurons that survive ischemic insult increased (Global M = 0.97). Conclusions : these data suggest that Scutellaria baicalensis GEORGI increases the expression of antiapoptosis- and antioxidation- related genes in a way that can not yet be explained.

• Tuberculosis and Respiratory Diseases
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• v.54 no.4
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• pp.403-414
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• 2003

Background : Proteasome inhibitors can promote either cell survival or programmed cell death, depending on both the specific type and proliferative status of the cell. However, it is not well known whether inhibition of proteasome activity is related to apoptosis in lung cancer cells. In addition, the exact mechanisms responsible for apoptosis induced by proteasome inhibition are not well understood. In the present study, we have examined the effect of proteasome inhibition on lung cancer cells and tried to test the mechanisms that may be associated with the apoptosis of these cells. Methods : We examined the effect of proteasome inhibition with MG132 or PS-341 on cell survival in A549 and NCI-H157 lung cancer cells using MTT assay, and analyzed the cleavage of PARP by Western blot analysis to find evidence of apoptosis. Next, we evaluated the activation of caspase 3 by Western blot analysis and the activity of JNK by immunocomplex kinase assay. We also examined the changes in anti-apoptotic pathways like ERK and cIAP1 by Western blot analysis after inhibition of proteasome function. Results : We demonstrated that MG132 reduced cell survival by inducing apoptosis in A549 and NCI-H157 cells. Proteasome inhibition with MG132 or PS-341 was associated with activation of caspase 3 and JNK, reduced expression of activated ERK, and downregulation of cIAP1. Conclusion : Apoptosis induced by proteasome inhibition may be associated with the activation of pro-apoptotic pathways like caspase 3 and JNK and the inactivation of anti-apoptotic pathways in lung cancer cells.

• Radiation Oncology Journal
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• v.21 no.3
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• pp.207-215
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• 2003

Purpose: Extracellular signal-regulated kinase (ERK), which is part of the mitogen-activated protin kinase cascade, opposes initiation of the apoptotic cell death which is programmed by diverse cytotoxic stimuli. In this regard, the inhibition of ERK may be useful in improving the therapeutic efficacy of established anticancer agents. Materials and Methods: Murine hepatocarcinoma, HCa-I is known to be highly radioresistant with a TCD50 (radiation dose yield in $50\%$ cure) of more than 80 Gy. Various anticancer drugs have been found to enhance the radioresponse of this particular tumor but none were successful. The objective of this study was to explore whether the selective inhibition of MEK could potentiate the antitumor efficacy of radiation in vivo, particularly in the case on radioresistant tumor. C3H/HeJ mice hearing $7.5\~8\;mm$ HCa-I, were treated with PD98059(intratumoral injection of $0.16\;\mug/50\;\mul$). Results: Downregulation on ERK by PD98059 was most prominent 1h after the treatment. In the tumor growth delay assay, the drug was found to Increase the effect of the tumor radioresponse with an enhancement factor (EF) of 1.6 and 1.87. Combined treatment of 25 Gy radiation with PD98059 significantly increased radiation induced apoptosis. The peak apoptotic index (number on apoptotic nuclei in 1000 nuclei X100) was $1.2\%$ in the case of radiation treatment alone, $0.9\%$ in the case of drug treatment alone and $4.9\%,\;5.3\%$ in the combination treatment group. An analysis of apoptosis regulating molecules with Western blotting showed upregulation of p53, p$p21^{WAF1/CIP1}\;and\;Bcl-X_s$ in the combination treatment group as compared to their levels in either the radiation alone or drug alone treatment groups. The level of other molecules such as $Bcl-X_L4, Bax and Bcl-2 were changed to a lesser extent. Conclusion: The selective inhibition of MEK in combination with radiation therapy may have potential benefit in cancer treatment.