• Molecules and Cells
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• v.41 no.11
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• pp.933-942
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• 2018

Traditionally, small-molecule or antibody-based therapies against human diseases have been designed to inhibit the enzymatic activity or compete for the ligand binding sites of pathological target proteins. Despite its demonstrated effectiveness, such as in cancer treatment, this approach is often limited by recurring drug resistance. More importantly, not all molecular targets are enzymes or receptors with druggable 'hot spots' that can be directly occupied by active site-directed inhibitors. Recently, a promising new paradigm has been created, in which small-molecule chemicals harness the naturally occurring protein quality control machinery of the ubiquitin-proteasome system to specifically eradicate disease-causing proteins in cells. Such 'chemically induced protein degradation' may provide unprecedented opportunities for targeting proteins that are inherently undruggable, such as structural scaffolds and other non-enzymatic molecules, for therapeutic purposes. This review focuses on surveying recent progress in developing E3-guided proteolysis-targeting chimeras (PROTACs) and small-molecule chemical modulators of deubiquitinating enzymes upstream of or on the proteasome.

• Journal of Yeungnam Medical Science
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• v.34 no.2
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• pp.275-278
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• 2017

Small cell lung carcinoma (SCLC) is a cancer that shows aggressive behavior, early spread to distant sites, and frequent association with distinct paraneoplastic syndromes. Spontaneous remission of cancer, particularly of SCLC, is a rare biological event. Cases involving spontaneous regression of SCLC were reported, and were associated with paraneoplastic syndromes of the nervous system. This article reports on a 78-year-old man with SCLC in remission, with neurological symptoms. The patient visited the hospital because of generalized weakness, and imaging studies revealed a mass in the lower lobe of the left lung, pathological evaluation showed SCLC. The patient refused oncologic treatment and was treated only with conservative care. In follow-up study the diameter of the mass had decreased from initial 32 mm, 9 months after admission to 20 mm, 17 months after admission to 13 mm. The patient kept complaining of generalized weakness, dizziness, and paresthesia of limbs. We assumed that, in this case, the spontaneous remission of lung cancer was related to the immunologic response directed against the tumor, which is believed to be an important factor in the pathogenesis of paraneoplastic neurologic syndromes.

• Tuberculosis and Respiratory Diseases
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• v.42 no.2
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• pp.156-164
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• 1995

Background: We had undergone this study to investigate clinical progress of this disease and to decide the role of aggressive diagnostic approaches, the efficacy of treatments and prognoses. Methods: A retrospective study was done on 113 patients who had been diagnosed to metastatic adenocarcinoma of pleura by pleural fluid cytology(106 cases) or pleural needle biopsy(22 cases), at Presbyterian Medical Center, from Jan. 1990 to Dec. 1994. Results: 1) The patients were composed of 59 males(52.2%) and 54 females(47.8%), and the mean age distribution was $57.4{\pm}12.1$ years. 2) The site of origin was lung cancer 46.9%(53/113), stomach cancer 20.4%(23/113), breast cancer 11.5%(13/113), and unknown primary site 6.2%(7/113 cases), as a whole. In male, lung cancer was 55.9%(33/59), stomach cancer was 28.8%(17/59), and in female, lung cancer was 37%(20/54), breast cancer was 24.1%(13/54) of cases. 3) The cardinal symptoms were dyspnea(69%), cough(61%), chest pain(50%), weight loss(50%), anorexia(49%), sputum(43%), malaise(30%). 4) The pleural fluid findings were exudative in 94.4%(102/108), serosanguinous or bloody in 36~53%, unilateral involvement in 74.3%(84/113) of cases, and lymphocyte predominance($71{\pm}27%$) in differential count of WBC. 5) CEA levels in pleural fluid or plasma were over 10ng/ml in 60.6%(40/66), and ADA levels in pleural fluid were under 40U/L in 95%(57/60) of cases. 6) The patients were managed by various methods, but the efficacy of treatment was uncertain. 7) The mean survival time was $12.7{\pm}13.5$ weeks. Conclusion: It seems to be no effective treatment methods yet and the prognosis was very poor in this disease, so the objectives of diagnostic approaches and treatment methods should be directed to early diagnosis, treatment and prevention of curable disease. And we must make our best endeavors to lengthen the survival time and improve the quality of patients' life.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9487-9494
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• 2014

Background: The size of a hepatic neoplasm is critical for staging, prognosis and selection of appropriate treatment. Our study aimed to compare the radiological size of solid hepatocellular carcinoma (HCC) masses on magnetic resonance imaging (MRI) with the pathological size in a Chinese population, and to elucidate discrepancies. Materials and Methods: A total of 178 consecutive patients diagnosed with HCC who underwent curative hepatic resection after enhanced MRI between July 2010 and October 2013 were retrospectively identified and analyzed. Pathological data of the whole removed tumors wereassessed and differences between radiological and pathological tumor size were identified. All patients were restaged using a modified Tumor-Node-Metastasis (TNM) staging system postoperatively according to the maximum diameter alteration. The lesions were classified as hypo-staged, iso-staged or hyper-staged for qualitative assessment. In the quantitative analysis, the relative pre and postoperative tumor size contrast ratio ($%{\Delta}size$) was also computed according to size intervals. In addition, the relationship between radiological and pathological tumor diameter variation and histologic grade was analyzed. Results: Pathological examination showed 85 (47.8%) patients were overestimated, 82 (46.1%) patients underestimated, while accurate measurement by MRI was found in 11 (6.2%) patients. Among the total subjects, 14 (7.9%) patients were hypo-staged and 15 (8.4%) were hyper-staged post-operatively. Accuracy of MRI for calculation and characterized staging was related to the lesion size, ranging from 83.1% to 87.4% (<2cm to ${\geq}5cm$, p=0.328) and from 62.5% to 89.1% (cT1 to cT4, p=0.006), respectively. Overall, MRI misjudged pathological size by 6.0 mm (p=0.588 ), and the greatest difference was observed in tumors <2cm (3.6 mm, $%{\Delta}size=16.9%$, p=0.028). No statistically significant difference was observed for moderately differentiated HCC (5.5mm, p=0.781). However, for well differentiated and poorly differentiated cases, radiographic tumor maximum diameter was significantly larger than the pathological maximum diameter by 3.15 mm and underestimated by 4.51 mm, respectively (p=0.034 and 0.020). Conclusions: A preoperative HCC tumor size measurement using MRI can provide relatively acceptable accuracy but may give rise to discrepancy in tumors in a certain size range or histologic grade. In pathological well differentiated subjects, the pathological tumor size was significantly overestimated, but underestimated in poorly differentiated HCC. The difference between radiological and pathological tumor size was greatest for tumors <2 cm. For some HCC patients, the size difference may have implications for the decision of resection, transplantation, ablation, or arterially directed therapy, and should be considered in staging or selecting the appropriate treatment tactics.

• Radiation Oncology Journal
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• v.10 no.1
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• pp.7-14
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• 1992

Between August 1988 and December 1991, 24 patients with intracranial tumors were treated with stereotactic radiosurgery(RS) using a 10 MV linear accelerator at Severance Hospital, Yonsei University College of Medicine. There were 5 meningiomas, 3 craniopharyngiomas, 9 glial tumors, 2 solitary metastases, 2 acoustic neurinomas, 2 pineal tumors, and 1 non-Hodgkin's lymphoma. Ten patients were treated as primary treatment after diagnosis with stereotactic biopsy or neuroimaging study. Nine patients underwent RS for post-op. residual tumors and three patients as a salvage treatment for recurrence after external irradiation. Two patients received RS as a boost followed by fractionated conventional radiotherapy. Among sixteen patients who were followed more than 6 months with neuroimage, seven patients (2 meningiomas, 4 benign glial tumors, one non-Hodgkin's lymphoma) showed complete response on neuroimage after RS and nine patients showed decreased tumor size. There was no acute treatment related side reaction. Late complications include three patients with symptomatic peritumoral brain edema and one craniopharyngioma with optic chiasmal injury. Through this early experience, we conclude that stereotactically directed single high doses of irradiation to the small intracranial tumors is effective for tumor control. However, in order to define the role of radiosurgery in the management of intracraniai tumors, we should get the long-term results available to demonstrate the benefits versus potential complications of this therapeutic modality.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2453-2458
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• 2015

Background: X-linked inhibitor of apoptosis protein (XIAP) associated factor 1 (XAF1) exhibits aberrantly low or absent expression in various human malignancies, closely associated with anti-apoptosis and overgrowth of cancer cells. However, limited attention has been directed towards the contribution of XAF1 to invasion, apoptosis, and cisplatin (DDP)-resistance of epithelial ovarian cancer (EOC) cells. This study aimed to evaluate the potential effects of XAF1 on invasion, cell cycle, apoptosis, and cisplatin-resistance by overexpressing XAF1 in SKOV-3 and SKOV-3/DDP cells. Methods and Results: The pEGFP-C1-XAF1 plasmid was transfected into SKOV-3 and SKOV-3/DDP cells, and the expression of XAF1 at both mRNA and protein levels was analyzed by reverse transcription-PCR and Western blotting. Overexpression of XAF1 suppressed XIAP expression in both SKOV-3 and SKOV-3/DDP cells. Transwell invasion assays demonstrated that XAF1 exerted a strong anti-invasive effect in XAF1-overexpressing cells. Moreover, flow cytometry analysis revealed that XAF1 overexpression arrested the cell cycle at G0/G1 phase, and cell apoptosis analysis showed that overexpression of XAF1 enhanced apoptosis of SKOV-3 and SKOV-3/DDP cells apparently by activating caspase-9 and caspase-3. Furthermore, MTT assay confirmed a dose-dependent inhibitory effect of cisplatin in the tested tumor cells, and overexpression of XAF1 increased the sensitivity of SKOV-3 and SKOV-3/DDP cells to cisplatin-mediated antiproliferative effects. Conclusions: In summary, our data indicated that overexpression of XAF1 could suppress XIAP expression, inhibit invasion, arrest cell cycle, promote apoptosis, and confer cisplatin-sensitivity in SKOV-3 and SKOV-3/DDP cells. Therefore, XAF1 may be further assessed as a potential target for the treatment of both cisplatin-resistant and non-resistant EOCs.

• Journal of Life Science
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• v.26 no.7
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• pp.826-834
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• 2016

The present investigation was undertaken to examine the effectiveness of the combination treatment of an Hsp90 inhibitor and a SIRT1 inhibitor on suppressing the growth of chemo-resistant human cancer cells. We showed that inhibition of SIRT1 effectively potentiated the cytotoxicity of 17-allylamino-17-demethoxygeldanamycin (17-AAG) and reversed Hsp90 inhibitor resistance in multidrug-resistant (MDR) human ovarian HeyA8-MDR cells. Amurensin G, a potent natural SIRT1 inhibitor, enhanced Hsp90 inhibitor-mediated abrogation of the Hsp90 chaperone function and accelerated degradation of mutated p53 (mut p53), an Hsp90 client protein, by up-regulation of ubiquitin ligase CHIP. Knock-down of CHIP significantly attenuated amurensin G-induced mut p53 degradation. Down-regulation of mut p53 reduced the expression of heat shock factor1 (HSF1)/heat shock proteins (Hsps), a major cause of Hsp90 inhibitor resistance, which led to sensitization of the MDR cells to the Hsp90 inhibitor by the SIRT1 inhibitor. Amurensin G potentiated cytotoxicity of the Hsp90 inhibitor in HeyA8-MDR cells through suppression of 17-AAG-induced Hsp70 and Hsp27 induction via down-regulation of mut p53/HSF1, and it caused activation of PARP and inhibition of Bcl-2. Our data suggests that SIRT1 inhibitors could be used to sensitize MDR cells to Hsp90 inhibitors, possibly through suppression of the mut p53/HSF1-dependent pathway, and a novel mut p53-directed action of SIRT1 inhibition could effectively prevent mut p53 accumulation in MDR cells.

• Radiation Oncology Journal
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• v.27 no.3
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• pp.133-139
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• 2009

Purpose: This study was designed to analyze the outcome and toxicity of thoracic radiation therapy (TRT) and chemotherapy for patients who suffer with limited-stage small-cell lung cancer (LS-SCLC). Materials and Methods: We retrospectively studied 35 patients with LS-SCLC. TRT was administered once daily (1.8 to 2 Gy per fraction) and it was directed to the primary tumor for a total 50 to 66 Gy in 6 to 7 weeks. The patients received four cycles of etoposide plus cisplatin. TRT was begun on day 1 of the first cycle of chemotherapy in the concurrent arm and after the fourth cycle in the sequential arm. Results: The median progression-free survival time was 16.5 months (95% confidence interval [CI], 9.0 to 24.1 months) for the sequential arm, and 26.3 months (95% CI, 16.6 to 35.9 months) for the concurrent arm. The 2-year progression-free survival rate was 16.0 percent for the sequential arm and 50.0 percent for the concurrent arm (p=0.0950 by log-rank test). Leukopenia was more severe and more frequent in the concurrent arm than in the sequential arm. However, severe esophagitis was infrequent in both arms. The radiotherapy was interrupted more frequently in the concurrent arm than in the sequential arm due to hematologic toxicities (p=0.001). Conclusion: This study suggests that concurrent TRT with etoposide plus cisplatin is more effective for the treatment of LS-SCLC than sequential TRT. However, there is a significant increase in the risk of toxicities, and radiotherapy was frequently interrupted in the concurrent arm due to hematologic toxicities.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.33-45
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• 2011

Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of cancer cell. Inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the cancer cell was reported. However, its role during oocyte maturation and early embryo development is very insufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on meiotic maturation and early embryonic development in pigs. We also investigated several indicators of developmental potential, including structural integrity, gene expression (Hsp90-, cell cycle-, and apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Then, we examined the roles of Hsp90 inhibitor on viability of primary cells in pigs. Porcine oocytes were cultured in the NCSU-23 medium with or without 17-AAG for 44 h. The proportion of GV arrested oocytes was significantly different between the 17-AAG treated and untreated group (78.2 vs 34.8%, p<0.05). After completion of meiotic maturation, the proportion of MII oocytes was lower in the 17-AAG treated group than in the control group (27.9 vs 71.0%, p<0.05). After IVF, the percentage of penetrated oocytes was significantly lower in the 17-AAG treated group (25.2%), resulting in lower normal pronucleus formation (2PN of 14.6%). Therefore, the inhibition of meiotic progression by Hsp90 inhibitor played a critical role in fertilization status. Porcine embryo were cultured in the PZM-3 medium with or without 17-AAG for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (7.5 vs 4.4, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation porcine blastocysts. The mRNA expressions of cell cycle-related genes were down-regulated in the 17-AAG treated group compared with control. Also, the expression of the pro-apoptotic gene Bax increased in 17-AAG treated group, whereas expression of the anti-apoptotic gene Bel-XL decreased. However, the expression of ER stress-related genes did not changed by 17-AAG. Cultured pESF cells were treated with or without 17-AAG and used for MIT assay. The results showed that viability of pESF cells were decreased by treatment of 17-AAG ($2{\mu}M$) for 24 hr. These results indicated that 17-AAG decreased cell proliferation and increased cell death. Expression patterns Hsp90 complex genes (Hsp70 and p23), cell cycle-related genes (cdc2 and cdc25c) and apoptosis-related genes (Bax and Bcl-XL) were significantly changed by using RT-PCR analysis. The spliced form of pXbp-1 product (pXbp-1s) was detected in the tunicamycin (TM) treated cells, but it is not detected in 17-AAG treated cells. In conclusion, Hsp90 appears to play a direct role in porcine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with cell cycle- and apoptosis-related genes expression in developing porcine embryos.

• Radiation Oncology Journal
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• v.17 no.1
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• pp.36-41
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• 1999

Purpose : We reviewed the treatment results for the patients with locally recurrent rectal carcinoma. The object was to evaluate the treatment outcome and to identify the prognostic factors influencing the survival. Methods and Materials: Twenty-eight patients with locally recurrent rectal carcinoma treated principally with external-beam radiation therapy between 1982 to 1996 in the Department of Radiation Oncology at Paik and Hanyang Hospital were reviewed retrospectively Of these, 17 patients had initially abdominoperineal resection, 9 had low anterior resection, and 2 had local excision. No patients had received adjuvant radiation therapy for the primary disease. There were 14 men and 14 women whose ages ranged from 31 to 72 years (median age:54.5). Median time from initial surgery to the start of radiation therapy for local recurrence was 11 months (4~47 months). Radiation therapy was given with total doses ranging from 27 to 64.8 Gy (median=51.2 Gy). Results : The median survival was 16.7 months. The 2-year and 5-year survival rates were 20.1%, 4.1% respectively. Upon multivariate analysis, overall survival was positively correlated with duration of intervals from initial surgery to local recurrence (P=0.039). Relief of pelvic symptoms was achieved in 17 of 28 patients (60.7%). Pain and bleeding responded in 40% and 100% of patients, respectively Conclusions : Patients with locally recurrent rectal carcinoma treated with radiotherapy have benefited symptomatically, and might have increased survivals with a small chance of cure. But, patient were rarely cured (median survival : 10 months, 5-year survival : less than 5%). Overall survival was positively correlated with long intervals from initial surgery to local recurrence. Future efforts should be directed to the use of effective therapy for patients with locally recurrent rectal carcinoma and adjuvant therapy for patients with rectal cancer to reduce the incidence of pelvic recurrence.