Miso Kim

Characterization of four isolates of Bombyx mori nucleopolyhedrovirus.

Summary.u2002Bombyx mori nucleopolyhedroviruses (BmNPVs), isolated from a sericultural Korean farm, were purified and characterized by their DNA restriction pattern, virus replication, polyhedra production and gene structures. The EcoRu2009I and Sal I fragments showed similar overall patterns with minor difference but distinguishable patterns in each isolate. There was no significant difference in the virus replication pattern, yield of total polyhedra production and polyhedra morphology, but the yield of released polyhedra by BmNPV-K1 in Bm5 cells was 2 to 5 times higher than that of other isolates. In comparative studies of p10 gene, BmNPV-K1 and K3 had same structure and they encoded a protein consisting of 94 amino acids. Although BmNPV-K2 encoded the same length of amino acids with BmNPV-K1 and K3, it had different structure, and BmNPV-K4 had the p10 gene encoding 70 amino acids.

Programmed death ligand-1 expression and its prognostic role in esophageal squamous cell carcinoma

AIM To investigate the expression and prognostic role of programmed death ligand-1 (PD-L1) in locally advanced esophageal squamous cell carcinoma (ESCC). METHODS A total of 200 patients with ESCC who underwent radical esophagectomy with standard lymphadenectomy as the initial definitive treatment in Seoul National University Hospital from December 2000 to April 2013 were eligible for this analysis. Tissue microarrays were constructed by collecting tissue cores from surgical specimens, and immunostained with antibodies directed against PD-L1, p16, and c-Met. Medical records were reviewed retrospectively to assess clinical outcomes. Patients were divided into two groups by PD-L1 status, and significant differences in clinicopathologic characteristics between the two groups were assessed. RESULTS Tumor tissues from 67 ESCC patients (33.5%) were PD-L1-positive. Positive p16 expression was observed in 21 specimens (10.5%). The H-score for c-Met expression was ≥ 50 in 42 specimens (21.0%). Although PD-L1-positivity was not significantly correlated with any clinical characteristics including age, sex, smoking/alcoholic history, stage, or differentiation, H-scores for c-Met expression were significantly associated with PD-L1-positivity (OR = 2.34, 95%CI: 1.16-4.72, P = 0.017). PD-L1 expression was not significantly associated with a change in overall survival (P = 0.656). In contrast, the locoregional relapse rate tended to increase (P = 0.134), and the distant metastasis rate was significantly increased (HR = 1.72, 95%CI: 1.01-2.79, P = 0.028) in patients with PD-L1-positive ESCC compared to those with PD-L1-negative ESCC. CONCLUSION PD-L1 expression is positively correlated with c-Met expression in ESCC. PD-L1 may play a critical role in distant failure and progression of ESCC.

Differing effects of adjuvant chemotherapy according to BRCA1 nuclear expression in gastric cancer

BackgroundWe aimed to investigate the role of BRCA1 nuclear expression in sporadic gastric cancer; currently, the role remains unknown.MethodsPatients with gastric cancer who received curative operation with D2 dissection were enrolled in this study. Adjuvant chemotherapy was administered at the discretion of the physician. According to BRCA1 nuclear expression analysis by immunohistochemistry (IHC) on tissue microarrays using anti-BRCA1 antibody MS110, BRCA1 expression was classified as negative, low expression, and high expression.ResultsAmong 318 cases, 155 cases (48.7xa0%) were identified as BRCA1-negative by IHC and 96 cases (30.2xa0%) revealed BRCA1 low expression, 67 cases (21.0xa0%) showed BRCA1 high expression. The negative or reduced expression of BRCA1 was more frequent in more advanced-stage disease (pxa0<xa00.001) and was associated with perineural invasion (pxa0=xa00.032). Disease-free survival (DFS) was significantly decreased with reduced BRCA1 expression (pxa0=xa00.027). This tendency was also observed in overall survival (OS), although the difference was not significant. The poorer prognosis of BRCA1-negative tumors was overcome through adjuvant chemotherapy. The benefit of adjuvant chemotherapy for DFS and OS in stage III was enhanced only in BRCA1-negative tumors (pxa0<xa00.001, pxa0<xa00.001, respectively), but not in BRCA1-positive tumors (pxa0=xa00.236, pxa0=xa00.148, respectively).ConclusionThe reduction of BRCA1 nuclear expression is associated with advanced stage and perineural invasion. Moreover, negative BRCA1 nuclear expression is a predictive marker regarding the benefit of adjuvant chemotherapy in sporadic gastric cancer; these novel findings are of great importance, and further, larger studies are warranted.

Comparison of Native Escherichia Coli L-Asparaginase Versus Pegylated Asparaginase, in Combination with Ifosfamide, Methotrexate, Etoposide, and Prednisolone (IMEP), in Extranodal NK/T Cell Lymphoma, Nasal Type (NTCL)

Purpose The aim of this study was to compare asparaginase-related toxicities in two asparaginase preparations, namely native Escherichia coli L-asparaginase (L-ASP) and pegylated asparaginase (PEG-ASP) in combination with ifosfamide, methotrexate, etoposide, and prednisolone (IMEP) in natural killer (NK)/T-cell lymphoma (NTCL). Materials and Methods A total of 41 NTCL patients who received IMEP plus native E. coli L-ASP or PEG-ASP at Seoul National University Hospital were included in this study between January 2013 and March 2016. IMEP/ASP treatment consisted of ifosfamide, methotrexate, etoposide, plus native E. coli L-ASP (6,000 IU/m2 on days 1, 3, 5, 7, 9, and 11) or PEG-ASP (2,500 IU/m2 on day 1) every 3 weeks. ASP-related toxicities, toxicity patterns, length of hospital stay, and clinical outcomes were compared between the different treatment groups. Results The frequency of ASP-related toxicities was similar between the IMEP plus native E. coli L-ASP group and the PEG-ASP group apart from hypofibrinogenemia (native E. coli L-ASP vs. PEG-ASP group, 86.4% vs. 36.8%; p=0.001). Although post-treatment transaminase and albumin levels were significantly high and low, respectively, hepatotoxicity gradients before and after treatment did not differ significantly between the groups. Since PEG-ASP was given at an outpatient clinic in some patients, length of hospital stay was significantly shorter in the IMEP plus PEG-ASP group (median, 4.0 vs. 6.0 days; p=0.002). A favorable tendency of clinical outcomes was observed in NTCL patients treated with IMEP plus PEG-ASP (complete remission rate, 73.7% vs. 45.5%; p=0.067). Conclusion IMEP plus PEG-ASP showed similar ASP-related toxicities, shorter length of hospital stay, and a trend towards improved clinical outcomes compared with IMEP plus native E. coli L-ASP in NTCL.

Costs and clinical outcomes of patients with diffuse large B-cell lymphoma in first remission: role of PET/CT surveillance

Background/Aims The role of [18F]-f luorodeoxyglucose positron emission tomography-computed tomography (PET/CT) in patients with diffuse large B-cell lymphoma (DLBCL) in first remission is unclear. Methods Medical costs within the first 3 years of treatment completion and clinical outcomes of 118 patients with DLBCL in first remission with and without surveillance PET/CT (PET/CT [+] group [n = 76] and PET/CT [–] group [n = 42], respectively) were retrospectively analyzed. Results In a propensity matched cohort with adjustment for International Prognostic Index risk and relapse, the PET/CT (+) group was shown to have similar medical costs as the PET/CT (–) group. Relapse-free survival (RFS) and overall survival (OS) were comparable between the two groups (median RFS not reached [NR] for both groups, p = 0.133; median OS NR, p = 0.542). Among 76 patients with surveillance PET/CT, 31 (40.8%) had findings suggestive of recurrence and 16 of these (51.6%) were later confirmed to have recurrent disease. Fifteen patients (48.4%) were confirmed to not have recurrence after follow-up CT or PET/CT evaluation (n = 10) and biopsy (n = 4). None of the patients with negative PET/CT findings had disease recurrence. Sensitivity, specificity, positive predictive value, and negative predictive value of PET/CT for detection of recurrence were 1, 0.75, 0.52, and 1, respectively. Conclusions Surveillance PET/CT resulted in similar clinical outcomes and medical costs compared to no surveillance PET/CT. Approximately half of patients with PET/CT findings of recurrence had no recurrence after follow-up imaging and biopsy, which would not have been carried out if PET/CT had not been performed in the first place.

Clinical factors affecting progression-free survival with crizotinib in ALK -positive non-small cell lung cancer

Background/Aims Although crizotinib is standard chemotherapy for advanced anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC), clinical factors affecting progression-free survival (PFS) have not been reported. The purpose of this study was to identify clinical factors affecting PFS of crizotinib and develop a prognostic model for advanced ALK-positive NSCLC. Methods Clinicopathologic features of patients enrolled in PROFILE 1001, 1005, 1007, and 1014 (training cohort) were reviewed. We conducted multivariate Cox analysis for PFS and overall survival (OS) in the training cohort (n = 159) and generated a proportional hazards model based on significant clinicopathologic factors, and then validated the model in an independent validation cohort (n = 40). Results In the training cohort, the objective response rate was 81.5%. Median PFS and OS from the start of crizotinib were 12.4 and 31.3 months, respectively. Multivariate Cox analysis showed poor performance status, number of metastatic organs (≥ 3), and no response to crizotinib independently associated shorter PFS. Based on a score derived from these three factors, median PFS and OS of patients with one or two factors were significantly shorter compared to those without these factors (median PFS, 22.4 months vs. 10.5 months vs. 6.5 months; median OS, not reached vs. 29.1 months vs. 11.8 months, respectively; p < 0.001 for each group). This model also had validated in an independent validation cohort. Conclusions Performance status, number of metastatic organs, and response to crizotinib affected PFS of crizotinib in ALK-positive NSCLC. Based on these factors, we developed a simple and useful prediction model for PFS.

A Phase II Trial of Pazopanib in Patients with Metastatic Alveolar Soft Part Sarcoma

Lessons Learned. Pazopanib shows a modest efficacy in metastatic alveolar soft part sarcoma. Clinical outcomes were comparable to those in previous studies using antiangiogenic drugs. Further prospective studies evaluating the benefit of pazopanib in alveolar soft part sarcoma with a larger sample are warranted to validate results. Background. Alveolar soft part sarcoma (ASPS) is a rare mesenchymal malignant tumor characterized by an unbalanced translocation, t(X;17)(p11.2;q25), which leads to the fusion of ASPSCR1 to the TFE3 transcription factor. Because this results in the upregulation of angiogenesis‐related transcripts, antiangiogenic drugs have been used in ASPS patients. Methods. This open‐label, single‐arm, multicenter, investigator‐initiated phase II trial was designed to evaluate efficacy and safety of pazopanib 800 mg once daily in patients with metastatic ASPS. The primary endpoint was investigator‐assessed overall response rate (ORR), and secondary endpoints were toxicity, progression‐free survival (PFS), and overall survival (OS). 68Ga‐RGD (Arg‐Gly‐Asp) positron emission tomography (PET) scan and gene expression profiling using NanoString platform were performed for biomarker analysis. Results. Six patients with histologically confirmed metastatic ASPS were enrolled between December 2013 and November 2014. Among six patients, one achieved a partial response (PR) (ORR 16.7%) and five patients showed stable disease (SD). With a median follow‐up of 33 months (range 18.7–39.3 months), median PFS was 5.5 months (95% confidence interval [CI] 3.4–7.6 months), and median OS was not reached. There were no severe toxicities except one patient with grade 3 diarrhea. Conclusion. Pazopanib showed modest antitumor activity with manageable toxicities for patients with metastatic ASPS.

The Risk of Herpes Zoster in Patients with Non-small Cell Lung Cancer according to Chemotherapy Regimens: Tyrosine Kinase Inhibitors versus Cytotoxic Chemotherapy

Purpose Despite the successful use of tyrosine kinase inhibitors (TKIs) in cancer patients, their effect on herpes zoster development has not been studied. The aim of this study was to evaluate and compare the effects of epidermal growth factor receptor (EGFR) TKI and cytotoxic chemotherapy on the risk of herpes zoster development in non-small cell lung cancer (NSCLC) patients. Materials and Methods We conducted a medical review of all eligible NSCLC patients in Seoul National University hospital between 2002 and 2015. We classified patients based on whether they previously underwent EGFR TKI therapy into either the TKI group or the cytotoxic group. We compared the incidence rates of herpes zoster during TKI therapy and cytotoxic chemotherapy. Additionally, the longitudinal risk of herpes zoster from TKIs was analyzed using the incidence rate ratio (IRR) of the TKI group to the cytotoxic group and the log-rank test of the Kaplan-Meier method. Results Of the 2,981 NSCLC patients, 54 patients (1.54%) developed herpes zoster. In the TKI group (2,002 patients), the IRR of herpes zoster during TKI therapy compared to that during cytotoxic chemotherapy was 1.05 (95% confidence interval [CI], 0.53 to 2.09). The IRR of the TKI group compared to the cytotoxic group was 1.33 (95% CI, 0.64 to 2.76). The Kaplan-Meier cumulative risk of both groups was not significantly different. Conclusion Our results show that the incidence rate of herpes zoster in the TKI group was not statistically different from the incidence in the cytotoxic group during and after chemotherapy in NSCLC patients.

Acquired Resistance of MET -Amplified Non-small Cell Lung Cancer Cells to the MET Inhibitor Capmatinib

Purpose Amplified mesenchymal-epithelial transition factor, MET, is a receptor tyrosine kinase (RTK) that has been considered a druggable target in non-small cell lung cancer (NSCLC). Although multiple MET tyrosine kinase inhibitors (TKIs) are being actively developed for MET-driven NSCLC, the mechanisms of acquired resistance to MET-TKIs have not been well elucidated. To understand the mechanisms of resistance and establish therapeutic strategies, we developed an in vitro model using the MET-amplified NSCLC cell line EBC-1. Materials and Methods We established capmatinib-resistant NSCLC cell lines and identified alternative signaling pathways using 3′ mRNA sequencing and human phospho-RTK arrays. Copy number alterations were evaluated by quantitative polymerase chain reaction and cell proliferation assay; activation of RTKs and downstream effectors were compared between the parental cell line EBC-1 and the resistant cell lines. Results We found that EBC-CR1 showed an epidermal growth factor receptor (EGFR)‒dependent growth and sensitivity to afatinib, an irreversible EGFR TKI. EBC-CR2 cells that had overexpression of EGFR-MET heterodimer dramatically responded to combined capmatinib with afatinib. In addition, EBC-CR3 cells derived from EBC-CR1 cells that activated EGFR with amplified phosphoinositide-3 kinase catalytic subunit α (PIK3CA) were sensitive to combined afatinib with BYL719, a phosphoinositide 3-kinase α (PI3Kα) inhibitor. Conclusion Our in vitro studies suggested that activation of EGFR signaling and/or genetic alteration of downstream effectors like PIK3CA were alternative resistance mechanisms used by capmatinib-resistant NSCLC cell lines. In addition, combined treatments with MET, EGFR, and PI3Kα inhibitors may be effective therapeutic strategies in capmatinib-resistant NSCLC patients.

Clinical significance of rituximab infusion-related reaction in diffuse large B-cell lymphoma patients receiving R-CHOP

Background/Aims This study was to evaluate the clinical significance of infusion-related reaction (IRR) of rituximab in diffuse large B-cell lymphoma (DLBCL) patients who received R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) as a first-line chemotherapy. Methods The medical records of 326 patients diagnosed with DLBCL were re trospectively analyzed. Both doctor’s progress records and nursing records were reviewed. IRR was graded according to the National Cancer Institute Common Terminology Criteria. Results IRR was not associated with overall survival (OS) or progression-free survival (PFS) of DLBCL patients as compared to those who did not have IRR (OS: median 78.0 months vs. 69.0 months, p = 0.700; PFS: median 65.4 months vs. 64.0 months, p = 0.901). IRR grade did not affect OS or PFS. B symptoms was independently associated with IRR (hazard ratio [HR], 1.850; 95% confidence interval [CI], 1.041 to 3.290; p = 0.036). Further, bone marrow involvement was independently associated with re-IRR (HR, 4.904; 95% CI, 0.767 to 3.118; p = 0.029). Conclusions Our study shows that IRR of rituximab is not associated with OS or PFS of DLBCL patients who received R-CHOP. Furthermore, our study suggests a need for more careful observation for IRR in patients with B symptoms or bone marrow involvement.