• Journal of Life Science
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• v.30 no.12
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• pp.1070-1077
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• 2020

Treatment with anticancer drugs changes the expression of multiple genes related to cell proliferation, migration, and drug resistance. These changes in gene expression may be connected to regulatory networks for each other. This study showed that doxorubicin treatment induces the expression of oncogenic FosB and decreases the expression of oncogenic SETDB1 in A549 and H1299 human lung cancer cells, which are different in tumor suppressor p53 status. However, a small difference was detected in the quantitative expression of those proteins in the two kinds of cells. To examine the potential regulation of SETDB1 and FosB by p53, we predicted putative p53 binding sites on the genomic DNA of SETDB1 and FosB using a TF motif binding search program. These putative p53 binding sites were identified as 18 sites in the promoter regions of SETDB1 and 21 sites in the genomic DNA of FosB. A luciferase assay confirmed that p53 negatively regulated the promoter activities of SETDB1 and FosB. Furthermore, the results of RT-PCR, western blot, qPCR, and immunostaining experiments indicated that the transfection of exogenous p53 decreases the expression of SETDB1 and FosB in H1299 cells. This indicates that p53 negatively regulates the expression of SETDB1 and FosB at the transcriptional level. Collectively, the downregulation of SETDB1 and FosB by p53 may provide functional networks for apoptosis and for the survival of cancer cells during anticancer drug treatment.

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.562-574
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• 2021

MRI has the advantages of having excellent soft-tissue contrast and providing functional information without any harmful ionizing radiation. Although previous technical limitations restricted the use of chest MRI, recent technological advances and expansion of insurance coverage are increasing the demand for chest MRI. Recognizing the need for guidelines on appropriate use of chest MRI in Korean clinical settings, the Korean Society of Radiology has composed a development committee, working committee, and advisory committee to develop Korean chest MRI justification guidelines. Five key questions were selected and recommendations have been made with the evidence-based clinical imaging guideline adaptation methodology. Recommendations are as follows. Chest MRI can be considered in the following circumstances: for patients with incidentally found anterior mediastinal masses to exclude non-neoplastic conditions, for pneumoconiosis patients with lung masses to differentiate progressive massive fibrosis from lung cancer, and when invasion of the chest wall, vertebrae, diaphragm, or major vessels by malignant pleural mesothelioma or non-small cell lung cancer is suspected. Chest MRI without contrast enhancement or with minimal dose low-risk contrast media can be considered for pregnant women with suspected pulmonary embolism. Lastly, chest MRI is recommended for patients with pancoast tumors planned for radical surgery.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.291-301
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• 1998

Purpose : A retrospective study was conducted comparing single daily fraction (SDF) thoracic radiotherapy (TRT) with twice daily (BID) TRT to determine the potential benefit of BID TRT in limited-stage small cell lung cancer (SCLC). Endpoints of the study were response. survival, pattern of failure, and acute toxicity. Materials and Methods : Between November 1989 to December 1996, 78 patients with histologically proven limited-stage SCLC were treated at the Department of Therapeutic Radiology, Chungnam National University Hospital. Of these, 9 were irradiated for palliative intent, and 1 had recurrent disease. Remaining 68 patients were enrolled in this study. There were 26 patients with a median age of 58 years, and 22 (85$\%$) ECOG performance score of less than 1 in SDF TRT. There were 42 patients with a median age of 57 years, and 36 (86$\%$) ECOG performance score of less than 1 in BID TRT By radiation fractionation regimen, there were 26 in SDF TRT and 42 in BID TRT. SDF TRT consisted of 180 cGy, 5 days a week. BID TRT consisted of 150 cGy BID, 5 days a week in 13 of 42 and 120 cGy BID, in 29 of 42. And the twice daily fractions were separated by at least 4 hours. Total radiotherapy doses were between 5040 and 6940 cGy (median, 5040 cGy) in SDF TRT and was between 4320 and 5100 cGy (median, 4560 cGy) in BID TRT. Prophylactic cranial irradiation (PCI) was recommended for patients who achieved a CR. The recommended PCI dose was 2500 cGy/10 fractions. Chemotherapy consisted of CAV (cytoxan 1000 mg/$m^2$, adriamycin 40 mg/$m^2$, vincristine 1 mg/$m^2$) alternating with VPP (cisplatin 60 mg/$m^2$, etoposide 100 mg/$m^2$) every 3 weeks in 25 (96$\%$) of SDF TRT and in 40 (95$\%$) of BID TRT. Median cycle of chemotherapy was six in both group. Timing for chemotherapy was sequential in 23 of SDF TRT and in 3 BID TRT, and concurrent in 3 of SDF TRT and in 39 of BID TRT Follow-up ranged from 2 to 99 months (median, 14 months) in both groups. Results : Of the 26 SDF TRT, 9 (35$\%$) achieved a complete response (CR) and 14 (54$\%$) experienced a partial response (PR). Of the 42 BID TRT, 18 (43$\%$) achieved a CR and 23 (55$\%$) experienced a PR. There was no significant response difference between the two arms (p=0.119). Overall median and 2-year survival were 15 months and 26.8$\%$, respectively. The 2-year survivals were 26.9$\%$ and 28$\%$ in both arm, respectively (p=0.51). The 2-rear survivals were 35$\%$ in CR and 24.2$\%$ in PR, respectively. The grade 2 to 3 esophageal toxicities and grade 2 to 4 neutropenias were more common in BID TRT (p=0.028 0.003). There was no difference in locoregional and distant metastasis between the two arms (p=0 125 and 0.335, respectively). The most common site of distant metastasis was the brain. Conclusion : The median survival and 2-year survival were 17 months and 20.9$\%$ in SDF TRT with sequential chemotherapy, and 15 months and 28$\%$ in BID TRT with concurrent chemotherapy, respectively. We did not observe a substantial improvement of long-term survival in the BID TRT with concurrent chemotherapy compared with standard schedules of SDF TRT with sequential chemotherapy. The grade 2 to 3 esophageal toxicities and glade 2 to 4 neutropenias were more common in BID TRT with concurrent chemotherapy. Although the acute toxicities were more common in BID TRT with concurrent chemotherapy than SDF TRT with sequential chemotherapy, a concurrent chemotherapy and twice daily TRT was feasible. However further patient accrual and long-term follow up are needed to determine the potential benefits of BID TRT in limited-stage SCLC.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.253-263
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• 2002

Purpose : In order to understand in vivo radiation damage modifying of bFGF on jejunal mucosa, bone marrow and the effect of bFGF on the growth of transplanted mouse sarcoma 180 tumor in mice. Materials and Methods : Mice were treated with $6\;{\mu}g$ of bFGF at 24 hours and 4 hours before exposing to 600 cGy, 800 cGy and 1,000 cGy total body irradiation (TBI), and then exposed to 3,000 cGy local radiation therapy on the tumor bearing thigh. Survival and tumor growth curve were plotted in radiation alone group and combined group of bFGF and irradiation (RT). Histologic examination was performed in another experimental group. Experimental groups consisted of normal control, tumor control, RT (radiation therapy) alone, $6\;{\mu}g$ bFGF alone, combined group of $3\;{\mu}g$ bFGF and irradiation (RT), combined group of $6\;{\mu}g$ bFGF and irradiation (RT). Histologic examination was peformed with H-E staining in marrow, jejunal mucosa, lung and sarcoma 180 bearing tumor. Radiation induced apoptosis was determined in each group with the DNA terminal transferase nick-end labeling method ($ApopTag^{\circledR}$ S7100-kit, Intergen Co.) Results : The results were as follows 1) $6\;{\mu}g$ bFGF given before TBI significantly improved the survival of lethally irradiated mice. bFGF would protect against lethal bone marrow syndrome. 2) $6\;{\mu}g$ bFGF treated group showed a significant higher crypt depth and microvilli length than RT alone group (p<0.05). 3) The bone marrow of bFGF treated group showed less hypocellularity than radiation alone group on day 7 and 14 after TBI (p<0.05), and this protective effect was more evident in $6\;{\mu}g$ bFGF treated group than that of $3\;{\mu}g$ bFGF treated group. 4) bFGF protected against early radiation induced apoptosis in intestinal crypt cell but might have had no antiapoptotic effect in bone marrow stem cell and pulmonary endothelial cells. 5) There was no significant differences in tumor growth rate between tumor control and bFGF alone groups (p>0.05). 6) There were no significant differences in histopathologic findings of lung and mouse sarcoma 180 tumor between radiation alone group and bFGF treated group. Conclusions : Our results suggest that bFGF protects small bowel and bone marrow from acute radiation damage without promoting the inoculated tumor growth in C3H mice. Improved recovery of early responding normal tissue and reduced number of radiation induced apoptosis may be possible mechanism of radioprotective effect of bFGF.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.586-590
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• 2008

Background: Non-small cell lung cancer (NSCLC) patients histologically proven to have stage N2 disease by media-stinoscope or thoracoscope underwent subsequent neoadjuvant chemoradiotherapy. This study was designed to find out if there were any differences in survival or recurrence rates between N2 positive and N2 negative patients. Material and Method: Between January 1998 and December 2005, we retrospectively analyzed 69 patients who were divided into three groups. Group A consisted of patients whose N stage was downstaged, group B of patients whose N stage was the same, and Group C of patients who could not undergo surgery because of disease progression during neoadjuvant chemoradiotherapy. We analyzed and compared the mean survival, three-year survival, mean disease-free survival, and three-year disease-free survival rates for the three groups. Result: There were no demographic differences among the groups. The mean survival was 58, 47, and 21 months for groups A, B, and C, respectively. The mean survival was longest in group A, but no statistically significant difference was found on A-B or B-C group comparison (p>0.05). However, a significant difference was noted between group A and group C (p : 0.01). Three-year survival rates were 67%, 41%, and 21.6% for groups A, B, and C, respectively, with a statistical difference similar to that seen in mean survival. The mean disease-free survival was 44 months in group A and 45 months in group B, with no statistically significant difference noted. No significant differences were noted in the three-year disease-free survival rates (55.1%, 46.8%). Conclusion: There were no significant differences in survival or recurrence rates with changes in N stage after neoadjuvant chemoradiotherapy. However, mean survival, three-year survival, and three-year disease-free survival rates tended to be higher in downstaged patients. Nevertheless, the difference was statistically insignificant, and therefore further studies with more patients and longer follow-up are necessary to clarify the positive effects on the survival and prognosis of downstaged patients.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.55-63
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• 2004

Purpose : To evaluate the reflection of tumor motion according to the planning CT scan time. Material and Methods : A model of N-shape, which moved aiong the longitudinal axis during the ventilation caused by a mechanical ventilator, was produced. The model was scanned by planning CT, while setting the relative CT scan time (T: CT scan time/ventilatory period) to 0.33, 0.50, 0.67, 0.75, 1.00, 1.337, and 1.537. In addition, three patients with non-small cell lung cancer who received stereotactic radiosurgery In the Department of Radiation Oncology, Asan Medical Center from 03/19/2002 to 05/21/2002 were scanned. Slow (10 Premier, Picker, scan time 2.0 seconds per slice) and fast CT scans (Lightspeed, GE Medical Systems, with a scan time of 0.8 second per slice) were peformed for each patient. The magnitude of reflected movement of the N-shaped model was evaluated by measuring the transverse length, which reflected the movement of the declined bar of the model at each slice. For patients' scans, all CT data sets were registered using a stereotactic body frame scale with the gross tumor volumes delineated in one CT image set. The volume and three-dimensional diameter of the gross tumor volume were measured and analyzed between the slow and fast CT scans. Results : The reflection degree of longitudinal movement of the model increased in proportion to the relative CT scan times below 1.00 7, but remained constant above 1.00 T Assuming the mean value of scanned transverse lengths with CT scan time 1.00 T to be $100\%$, CT scans with scan times of 0.33, 0.50, 0.57, and 0.75 T missed the tumor motion by 30, 27, 20, and $7.0\%$ respectively, Slow (scan time 2.0 sec) and Fast (scan time 0.8 sec) CT scans of three patients with longitudinal movement of 3, 5, and 10 mm measured by fluoroscopy revealed the increases in the diameter along the longitudinal axis Increased by 6.3, 17, and $23\%$ in the slow CT scans. Conculsion : As the relative CT scan time increased, the reflection of the respiratory tumor movement on planning CT also Increased, but remained constant with relative CT scan times above 1.00 T When setting the planning CT scan time above one respiration period (>1.00 T), only the set-up margin is needed to delineate the planning target volume. Therefore, therapeutic ratio can be increased by reducing the radiation dose delivered to normal lung tissue.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.34-43
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• 2005

Purpose: $^{99m}Tc$-sestamibi(MIBI) and $^{99m}Tc$-tetrofosmin have been used as substrates for P-glycoprotein (Pgp) and multidrug resistance associated protein (MRP), which are closely associated with multidrug resistance of the tumors. To understand different handling of radiotracers in cancer cell lines expressing Pgp and MRP, we compared cellular uptakes of $^{99m}Tc$-MIBI and $^{99m}Tc$-tetrofosmin. The effects of cyclosporin A (CsA), well-known multidrug resistant reversing agent, on the uptake of both tracers were also compared. Materials and Methods: HCT15/CL02 human colorectal cancer cells for Pgp expressing cells, and human non-small cell lung cancer A549 cells for MRP expressing cells, were used for in vitro and in vivo studies. RT-PCR, western blot analysis and immunohistochemistry were used for detection of Pgp and MRP. MDR-reversal effect with CsA was evaluated at different drug concentrations after incubation with MIBI or tetrofosmin. Radioactivities of supernatant and pellet were measured with gamma well counter. Tumoral uptake of the tracers were measured from tumor bearing nude mice treated with or without CsA. Results: RT-PCR, western blot analysis of the cells and irnrnunochemical staining revealed selective expression of Pgp and MRP for HCY15/CL02 and A549 cells, respectively. There were no significant difference in cellular uptakes of both tracers in HCT15/CL02 cells, but MIBI uptake was slightly higher than that of tetrofosmin in A549 cells. Co-incubation with CsA resulted in a increase in cellular uptakes of MIBI and tetrofosmin. Uptake of MIBI or tetrofosmin in HCT15/CL02 cells was increased by 10- and 2.4-fold, and by 7.5 and 6.3-fold in A549 cells, respectively. Percentage increase of MIBI was higher than that of tetrofosmin with CsA for both cells (p<0.05). In vivo biodistribution study showed that MIBI (114% at 10 min, 257% at 60 min, 396% at 240 min) and tetrofosmin uptake (110% at 10 min, 205% at 60 min, 410% at 240 min) were progressively increased by the time, up to 240 min with CsA. But increases in tumoral uptake were not significantly different between MIBI and tetrofosmin for both tumors. Conclusion: MIBI seems to be a better tracer than tetrofosmin for evaluating MDR reversal effect of the modulators in vitro, but these differences were not evident in vivo tumoral uptake. Both MIBI and tetrofosmin seem to be suitable tracers for imaging Pgp- and MRP-mediated drug resistance in tumors.

• Radiation Oncology Journal
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• v.27 no.3
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• pp.126-132
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• 2009

Purpose: We wanted to evaluate the prognostic factors for the pathologic N2 non-small cell lung cancer (NSCLC) patients who were treated by postoperative radiotherapy. Materials and Methods: We retrospectively reviewed 112 pN2 NSCLC patients who underwent surgery and postoperative radiotherapy (PORT) From January 1999 to February 2008. Seventy-five (67%) patients received segmentectomy or lobectomy and 37 (33%) patients received pneumonectomy. The resection margin was negative in 94 patients, and it was positive or close in 18 patients. Chemotherapy was administered to 103 (92%) patients. Nine (8%) patients received PORT alone. The median radiation dose was 54 Gy (range, 45 to 66), and the fraction size was 1.8~2 Gy. Results: The 2-year overall survival (OS) rate was 60.2% and the disease free survival (DFS) rate was 44.7% for all the patients. Univariate analysis showed that the patients with multiple-station N2 disease had significantly reduced OS and DFS (p=0.047, p=0.007) and the patients with an advanced T stage ($\geq$T3) had significantly reduced OS and DFS (p<0.001, p=0.025). A large tumor size ($\geq$5 cm) and positive lymphovascular invasion reduced the OS (p=0.035, 0.034). Using multivariate analysis, we found that multiple-station N2 disease and an advanced T stage ($\geq$T3) significantly reduced the OS and DFS. Seventy one patients (63.4%) had recurrence of disease. The patterns of failure were loco-regional in 23 (20.5%) patients, distant failure in 62 (55.4%) and combined loco-regional and distant failure in 14 (12.5%) patients. Conclusion: Multiple involvement of mediastinal nodal stations for the pN2 NSCLC patients with PORT was a poor prognostic factor in this study. A prospective study is necessary to evaluate the N2 subclassification and to optimize the adjuvant treatment.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.295-301
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• 1993

Since Jan. 1991 a prospective randomized study for Stage III unresectable non small cell lung cancer (NSCLC) has been conducted to evaluate the response rate and tolerance of induction chemotherapy with MVP followed by hyperfractionated radiotherapy and evaluate the efficacy of maintenance chemotherapy in Asan Medical Center. All patients in this study were treated with hyperfractionated radiotherapy (120 cGy/fx BID, 6480 cGy/54 fx) following 3 cycles of induction chemotherapy, MVP (Mitomycin C 6 $mg/m^2,$ Vinblastin 6 $mg/m^2,$ Cisplatin 60 $mg/m^2$) and then the partial and complete responders from induction chemotherapy were randomized to 3 cycles of adjuvant MVP chemotherapy group and observation group. 48 patients were registered to this study until December 1992; among 48 patients 3 refused further treatment after induction chemotherapy and 6 received incomplete radiation therapy because of patient's refusal, 39 completed planned therapy. Twenty-three $(58\%)$ patients including 2 complete responders showed response from induction chemotherapy. Among the 21 patients who achieved a partial response after induction chemotherapy,1 patient rendered complete clearance of disease and 10 patients showed further regression of tumor following hyperfractionated radiotherapy. Remaining 10 patients showed stable disease or progression after radiotherapy. Of the sixteen patients judged to have stable disease or progression after induction chemotherapy, seven showed more than partial remission after radiotherapy but nine showed no response in spite of radiotherapy. Of the 39 patients who completed induction chemotherapy and radiotherapy, 25 patients $(64\%)$ including 3 complete responders showed more than partial remission. Nineteen patients were randomized after radio-therapy. Nine Patients were allocated to adjuvant chemotherapy group and 4/9 showed further regression of tumor after adjuvant chemotherapy. For the time being, there is no suggestion of a difference between the adjuvant chemotherapy group and observation group in distant metastasis rate and survival. Median survival time was 13 months. Actuarial survival rates at 6,12 and 18 months of 39 patients who completed this study were $84.6\%,\;53.7\%\;and\;40.3\%,$ respectively. The partial and complete responders from induction chemotherapy showed significantly better survival than non-responders (p=0.028). Incidence of radiation pneumonitis in this study group was less than that in historical control group inspite of induction chemotherapy. All patients tolerated hypertractionated radiotherapy without definite increase of acute complications compared with conventional radiotherapy group. The longer follow up is needed to evaluate the efficacies of induction and maintenance chemotherapy and survival advantage by hyperfractionated radiotherapy but authors are encouraged with an excellent tolerance, higher response rate and improvement of one year survival rate in patients of this study.

• Journal of Yeungnam Medical Science
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• v.28 no.1
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• pp.31-44
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• 2011

Background: The optimal timing of treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKI) in NSCLC patients has not yet been determined. Methods: We separated 228 patients with advanced /metastatic NSCLC treated with gefitinib into an early gefitinib group (patients who received gefitinib as first- or second-line treatment) and a delayed gefitinib group (patients who received gefitinib as third or fourth-line treatment) and attempted to determine whether the timing of gefitinib treatment affected clinical outcomes. Results: Median overall survival (OS), progression free survival (PFS), and median OS from first-line treatment of advanced/metastatic disease (OSt) for 111 patients in the early gefitinib group were 6.2 months, 3.3 months, and 11.6 months. However, median OS, PFS, and OSt for 84 patients in the delayed gefitinib group were 7.8 months, 2.3 months, and 22.7 months. No differences in OS and PFS were observed between the 2 groups. However, OSt was significantly longer in the delayed gefitnib group. Timing of gefitinib therapy was one of the independent predictors of OSt. Hb ${\geq}$ 10 g/dl, and having never smoked, and ECOG performance status ${\leq}1$ were independent predictors of better PFS. Conclusion：Deferral of gefitinib therapy in patientswith advanced ormetastatic NSCLC may be preferable if they are able to tolerate chemotherapy.