The Number of Positive Lymph Nodes as Prognostic Factor in ypN1 Breast Cancer with Neoadjuvant Chemotherapy

PURPOSE/OBJECTIVE(S)

This study aimed to assess the ability of the number of positive lymph nodes (LNP) after neoadjuvant chemotherapy (NAC) to stratify prognosis even within the same ypN stage in breast cancer patients.

MATERIALS/METHODS

A 6,443 non-metastatic breast cancer patients with ypN1 disease after NAC following primary surgery were identified using the stage, stage evaluation field, treatment fields from Surveillance Epidemiology and End Results (SEER) database. Survival analysis was performed for overall survival (OS) using Kaplan-Meier plot and Cox proportional hazard models.

RESULTS

Of patients, 1,132(17.6%) had 3 positive lymph nodes (LNP3), 4,363 (67.7%) patients were T1/2 stage and 538 (8.35%) patients were downstage after treatment. LNP3 group had a significantly worse OS than LNP1/2 group (5yr OS, 74.2% vs. 80.9%, p <0.001). Similar results were observed in cause specific survival analysis (5yr OS, 79.8% vs. 85.2%, p <0.001). In subgroup analysis, there was a significant difference in OS between LNP1/2 and LNP3 group for HER2 or triple negative subtype, (p <0.001), T1/2 stage (p <0.001) and stable/downstage of N stage (p <0.001 and 0.019, respectively), but not for luminal A/B subtype and T3/4 (p = 0.126, 0.629 and 0.154, respectively). Regarding the number of examined lymph node (LNE), OS was significantly decreased in patients with LNE ≤5 in LNP3 group (p <0.001) but not in LNP1/2 group. In multivariable analysis, the prognostic significance of LNP3 remained (p <0.001) and the following factors were significantly related to the prolonged OS; Luminal A/B (p<0.001 and 0.001, respectively), T1/2 stage (p <0.001), N1 stage (p <0.001), LNE (≤5 vs. >5, p = 0.001) and receipt of radiotherapy (p = 0.012). Even when PS matching was performed, the OS of LNP was worse than that of LNP1/2.

CONCLUSION

LNP could more stratify the patients with ypN1 breast cancer after NAC. LNP3 is significantly associated with OS even after adjusting for other prognosticators. In particular, since there is a potential difference in the magnitude of the impact of LNP3 according to LNE, it is necessary to consider both of them together for decision-making.

Prognostic implication of PD-L1 polymorphisms in non-small cell lung cancer treated with radiotherapy

Background

To investigate the impact of programmed death‐ligand 1 (PD‐L1) polymorphisms on the prognosis of non‐small cell lung cancer (NSCLC) patients treated with curative radiotherapy.

Methods

Four single nucleotide polymorphisms (SNPs) (rs822336G>C, rs822337T>A, rs822338C>T, and rs2297136A>G) in the PD‐L1 gene were evaluated in 124 NSCLC patients. Clinical stage was I in 28, II in 17, and III in 79 patients. Fifty‐seven patients received radiotherapy alone, including 28 patients who received stereotactic body radiotherapy. Sixty‐seven patients received sequential or concurrent chemoradiotherapy. Risk factors for survival outcomes were analyzed with the log‐rank test and multivariate Cox proportional hazards models.

Results

The rs822336GC+CC genotype was associated with better overall survival (OS) (hazard ratio [HR] = 0.60, 95% confidence interval [CI] = 0.37–0.97, p = 0.036) and regional failure‐free survival (RFFS) (HR = 0.32, 95% CI = 0.14–0.76, p = 0.009), compared with rs822336GG genotype. The rs822337TA+AA genotype was associated with better OS (HR =0.54, 95% CI = 0.34–0.88, p = 0.014), progression‐free survival (PFS) (HR = 0.64, 95% CI = 0.41–0.99, p = 0.046), and RFFS (HR = 0.38, 95% CI = 0.17–0.81, p = 0.013), compared with rs822337TT genotype. Three SNPs (rs822336, rs822337, and rs822338) were in linkage disequilibrium. Combined GTC and GTT (GT*) haplotype was associated with significantly worse OS (p = 0.018), PFS (p = 0.044), and RFFS (p = 0.038), compared with those with other combined haplotypes. Patients with diplotypes of two GT* haplotypes showed significantly worse OS (p = 0.023) and RFFS (p = 0.014) than those with other diplotypes.

Conclusions

These findings suggest that PD‐L1 polymorphisms could be predictive markers for NSCLC patients receiving radiotherapy.

Small heterodimer partner as a predictor of neoadjuvant radiochemotherapy response and survival in patients with rectal cancer: A preliminary study

Small heterodimer partner (SHP) plays an essential role in the regulation of innate immune and inflammatory responses. The aim of the present study was to identify whether SHP levels are associated with cancer immunology and treatment outcomes in rectal cancer. SHP expression was analyzed via gene set enrichment analysis and the OncoLnc database. In addition, immunohistochemistry and reverse transcription-quantitative PCR analyses were performed on the tissues of patients with locally advanced rectal cancer, and the associations of SHP expression with the clinicopathological and hematological features or treatment response to preoperative radiochemotherapy (pRCT) were analyzed retrospectively. Furthermore, the present study investigated whether SHP expression correlated with immune infiltration levels and immune checkpoint molecules in rectal cancer. The results revealed that low SHP mRNA expression was significantly associated with an inflammatory response and poor prognosis. The nuclear expression of SHP was associated with clinical N stage, neutrophil count, lymphocyte count, neutrophil-lymphocyte ratio and complete pathologic response following pRCT. The low nuclear expression of SHP was associated with poor overall and distant metastasis-free survival (DMFS). In multivariate analysis, the low nuclear expression of SHP was identified as a significant independent prognostic factor for DMFS and a marginally significant prognostic factor for overall survival in rectal cancer. Furthermore, patients with low SHP expression exhibited higher neutrophil and CD8⁺ T cell infiltration levels and higher PD-L1 expression in rectal adenocarcinoma. These results indicate that SHP may act as an anti-inflammatory mediator via the regulation of systemic and local immune responses in rectal cancer. Moreover, SHP might be useful a potential marker or therapeutic target in rectal cancer.

P–205 Epothilone D as an actin cytoskeleton stabilizer improved mitochondria bioenergenesis and blastocyst formation of mouse preimplantation embryo

Study question

What is primary factor of bioenergetics product activity between microtubule instability and the functional activity of mitochondria in embryo?

Summary answer

The actin cytoskeleton instability is presumably the primary cause for the bioenergenesis of mitochondrial function to the preimplantation embryo development.

What is known already

Mitochondria are cellular organelles dynamically moving and morphological changes. It provides for homeostatic energy to the cell. The dynamic property of the mitochondria is associated with the microtubule network in the cell. However, the stability of the microtubule was clearly identified for preimplantation embryo development.

Study design, size, duration

This study is designed to assess the ATP productivity of the mitochondria, and specifically to observe what its primary factor is in terms of providing microtubule stability in mammalian cells. Additionally, we investigated the relationship between blastocyst formation and actin cytoskeleton stabilization by EpD with 2-cell mice.

Participants/materials, setting, methods

We prepared the microtubule stability regulation model with the HEK293 cell line by using the microtubule stabilizer as an Epothilone D (EpD). Then we analyzed the metabolic activity of the cells through oxidative phosphorylation (OXP) ratios analysis. Also, we performed confocal live imaging to observe mitochondria morphology depending on the cells’ microtubule. Next, we treated EpD to 2-cell culture media for the analysis of blastocyst development ratios.

Main results and the role of chance

EpD significantly increased fusion form. Also, EpD enhance bioenergy ratios like OXP in the mitochondria and functional activity related marker, like mTOR compared with the control. These results suggest that microtubule stabilization enhances mitochondrial metabolism by increasing oxygen consumption. Also, EpD in 2-cell culture media led to a significant increase in the speed of development and 50% higher hatched out blastocyst formation ratios compared to the control group.

Limitations, reasons for caution

This study had limited animal experiments. For the next study, we are planning with an aim to improve the quality and development ratios of human embryos by EpD.

Wider implications of the findings: Microtubule stabilizer has a possibility to recover the mitochondria’s functional activity in the preimplantation embryo development. Mitochondrial functional activity along the actin cytoskeleton may play a pivotal role in determining the embryo quality and development ratios for archive pregnancy.

Trial registration number

non-clinical trials

Development of an Individualized Prediction Calculator for the Benefit of Postoperative Radiotherapy in Patients with Surgically Resected De Novo Stage IV Breast Cancer

PURPOSE

Locoregional treatment has been increasingly adopted for metastatic breast cancer at presentation. This study aims to develop an individualized calculator to predict the benefit of postoperative radiotherapy (PORT) for patients with surgically resected de novo stage IV breast cancer.

METHODS AND MATERIALS

We searched the Surveillance, Epidemiology, and End Results (SEER) database for patients diagnosed with stage IV breast cancer between 2010 and 2014. After applying exclusion criteria, a total of 4473 patients were included in the analysis. Propensity score matching was used to balance the individual characteristics of the patients. After identifying the significant prognosticators, a nomogram was developed using multivariate regression models and internally validated. A web-based calculator was then constructed using a fitted survival prediction model.

RESULTS

With a median follow-up of 34 months, the three-year overall survival (OS) rates were 54.1% in the surgery alone group and 63.5% in the surgery + PORT group (p < 0.001). The survival benefit of PORT was maintained after propensity score matching (p < 0.001). Interaction testing of the prognostic variables found significant interactions between PORT and the presence of brain metastasis (p = 0.001), and between PORT and hormonal receptor expression (p = 0.018). After reviewing the performance of various models, a log-normal distributed survival model was adopted, with a C-index of 0.695. A calibration plot verified that the predicted survival rates were strongly correlated with the actual OS rates. A web-based survival calculator was constructed to provide individualized estimates of survival according to PORT.

CONCLUSION

PORT significantly improved OS rates, though the individual benefit was affected by a number of factors. We successfully developed a nomogram and web-based calculator that predicted the prognosis according to PORT in patients with surgically resected de novo stage IV breast cancer. These tools are expected to be useful in clinical practice and in the design of related trials.

Screenomics: A Framework to Capture and Analyze Personal Life Experiences and the Ways that Technology Shapes Them

Digital experiences capture an increasingly large part of life, making them a preferred, if not required, method to describe and theorize about human behavior. Digital media also shape behavior by enabling people to switch between different content easily, and create unique threads of experiences that pass quickly through numerous information categories. Current methods of recording digital experiences provide only partial reconstructions of digital lives that weave - often within seconds - among multiple applications, locations, functions and media. We describe an end-to-end system for capturing and analyzing the "screenome" of life in media, i.e., the record of individual experiences represented as a sequence of screens that people view and interact with over time. The system includes software that collects screenshots, extracts text and images, and allows searching of a screenshot database. We discuss how the system can be used to elaborate current theories about psychological processing of technology, and suggest new theoretical questions that are enabled by multiple time scale analyses. Capabilities of the system are highlighted with eight research examples that analyze screens from adults who have generated data within the system. We end with a discussion of future uses, limitations, theory and privacy.

Clinicopathological Profiling of LC3B, an Autophagy Marker, and ESRRA (Estrogen-related Receptor-alpha) in Muscle-invasive Bladder Cancer

BACKGROUND/AIM

Microtubule-associated protein 1 light chain 3B (LC3B), an autophagy marker, has been used as a promising marker in various cancer types. However, the expression of LC3B in muscle-invasive bladder cancer (MIBC) and its prognostic significance have not been investigated. Recent studies pointed to the involvement of ESRRA in regulating autophagy via both transcriptional and post-translational control. In the current study, prognostic importance of LC3B and ESRRA in MIBC was investigated.

PATIENTS AND METHODS

We immunohistochemically studied the expression of LC3B and ESRRA in 56 MIBC samples.

RESULTS

LC3B was stained high in 16 patients (28.6%) and low or negative in 40 patients (71.4%). ESRRA expression was high for 20 patients (35.7%) and low for 36 patients (64.3%). Both LC3B (p=0.003) and ESRRA (p=0.026) expression correlated significantly with disease-free survival rates. Double-positive LC3B and ESRRA correlated with poor overall survival (p=0.007) and disease-free survival (p=0.001) in MIBC patients.

CONCLUSION

LC3B and ESRRA might be a useful prognostic factor in patients with MIBC. The co-expression of LC3B and ESRRA might be a prognostic and therapeutic target for patients with bladder cancer.

Long-Term Outcomes of Patients with Stent Tips Embedded into Internal Carotid Artery Branches during Aneurysm Coiling

BACKGROUND AND PURPOSE

During stent-assisted coiling of ICA aneurysms, stent tips are sometimes unintentionally embedded into ICA branches. Stent tips can be visualized because they have radiopaque markers. Concerns regarding stent tip misplacement include risks of artery perforation and occlusion. The aim of this study was to evaluate the long-term outcomes of ICA branches with embedded stent tips.

MATERIALS AND METHODS

ICA branches with embedded stent tips were identified among 35 patients with unruptured ICA aneurysms treated with stent-assisted coiling between November 2003 and November 2014. Patient clinical and angiographic outcomes associated with the embedded stent tip were analyzed.

RESULTS

Most of the 35 studied aneurysms were paraclinoid ICA aneurysms (n = 30). The most commonly involved ICA branch was the posterior communicating artery (26 patients, 74.3%), followed by the anterior choroidal artery (8 patients, 22.9%) and ophthalmic artery (1 patient, 2.9%). During the follow-up period (38.6 ± 17.9 months), no new neurologic deficits developed. Neither hemorrhagic nor thromboembolic events occurred. Angiography was performed during the final follow-up evaluation at a mean of 32.7 ± 18.0 months, and all ICA branches with embedded stent tips showed patent blood flow without severe luminal narrowing.

CONCLUSIONS

In our experience, placement of a stent tip into ICA branches during stent-assisted coiling was not associated with any major adverse events.

A national survey of lung cancer specialists' views on low-dose CT screening for lung cancer in Korea

Lung cancer specialists play an important role in designing and implementing lung cancer screening. We aimed to describe their 1) attitudes toward low-dose lung computed tomography (LDCT) screening, 2) current practices and experiences of LDCT screening and 3) attitudes and opinions towards national lung cancer screening program (NLCSP). We conducted a national web-based survey of pulmonologists, thoracic surgeons, medical oncologists, and radiological oncologists who are members of Korean Association for Lung Cancer (N = 183). Almost all respondents agreed that LDCT screening increases early detection (100%), improves survival (95.1%), and gives a good smoking cessation counseling opportunity (88.6%). Most were concerned about its high false positive results (79.8%) and the subsequent negative effects. Less than half were concerned about radiation hazard (37.2%). Overall, most (89.1%) believed that the benefits outweigh the risks and harms. Most (79.2%) stated that they proactively recommend LDCT screening to those who are eligible for the current guidelines, but the screening propensity varied considerably. The majority (77.6%) agreed with the idea of NLCSP and its beneficial effect, but had concerns about the quality control of CT devices (74.9%), quality assurance of radiologic interpretation (63.3%), poor access to LDCT (56.3%), and difficulties in selecting eligible population using self-report history (66.7%). Most (79.2%) thought that program need to be funded by a specialized fund rather than by the National Health Insurance. The opinions on the level of copayment for screening varied. Our findings would be an important source for health policy decision when considering for NLCSP in Korea.

The Effect of Hospital Case Volume on Clinical Outcomes in Patients with Nasopharyngeal Carcinoma: A Multi-institutional Retrospective Analysis (KROG-1106)

Purpose

The purpose of this study was to investigate the effect of hospital case volume on clinical outcomes in patients with nasopharyngeal carcinoma (NPC).

Materials and Methods

Data on 1,073 patients with cT1-4N0-3M0 NPC were collected from a multi-institutional retrospective database (KROG 11-06). All patients received definitive radiotherapy (RT) either with three-dimensional-conformal RT (3D-CRT) (n=576) or intensity-modulated RT (IMRT) (n=497). The patients were divided into two groups treated at high volume institution (HVI) (n=750) and low volume institution (LVI) (n=323), defined as patient volume ≥ 10 (median, 13; range, 10 to 18) and < 10 patients per year (median, 3; range, 2 to 6), respectively. Endpoints were overall survival (OS) and loco-regional progression-free survival (LRPFS).

Results

At a median follow-up of 56.7 months, the outcomes were significantly better in those treated at HVI than at LVI. For the 614 patients of propensity score-matched cohort, 5-year OS and LRPFS were consistently higher in the HVI group than in the LVI group (OS: 78.4% vs. 62.7%, p < 0.001; LRPFS: 86.2% vs. 65.8%, p < 0.001, respectively). According to RT modality, significant difference in 5-year OS was observed in patients receiving 3D-CRT (78.7% for HVI vs. 58.9% for LVI, p < 0.001) and not in those receiving IMRT (77.3% for HVI vs. 75.5% for LVI, p=0.170).

Conclusion

A significant relationship was observed between HVI and LVI for the clinical outcomes of patients with NPC. However, the difference in outcome becomes insignificant in the IMRT era, probably due to the standardization of practice by education.

Lung cancer specialist physicians' attitudes towards e-cigarettes: A nationwide survey

OBJECTIVES

Despite a sharp increase in e-cigarette use, there is debate about whether e-cigarettes are a viable alternative for harm reduction, and the forms that regulation should take. Healthcare providers can be effective in offering guidance to patients and their families and shaping regulatory policy. We described lung cancer specialists' attitudes toward e-cigarettes and its regulation.

METHODS

We undertook a nationwide survey of pulmonologists, thoracic surgeons, medical and radiological oncologists who are members of Korean Association for Lung Cancer. Survey items included beliefs and attitudes toward e-cigarettes, attitudes toward e-cigarette regulation and preparedness on discussing e-cigarettes with their patients.

RESULTS

Most respondents believed that e-cigarettes are not safer than conventional tobacco cigarettes (75.7%) or smokeless tobacco (83.2%), and feared that discussing e-cigarettes with the patients would encourage use (65.4%). They did not consider it a smoking cessation treatment (78.3%), and thus would not recommend it to smokers who do not want to quit (82.2%) or who failed to quit with conventional smoking cessation treatment (74.1%). Most respondents supported all examples of e-cigarette regulations, including the safety and quality check (97.8%), warning label (97.8%), advertisement ban (95.1%), restriction of flavoring (78.4%), minimum purchasing age (99.5%), and restriction of indoor use (94.6%). Most learned about e-cigarettes from media and advertisements, or conversation with patients rather than through professional scientific resources, and reported discomfort when discussing e-cigarette with patients.

CONCLUSION

Lung cancer specialist physicians in Korea doubt the safety of e-cigarette and use of e-cigarette as smoking cessation treatment, and supported strict regulation. However, only 20% reported that they obtained information on e-cigarettes from the scientific literature and many lacked adequate knowledge based on scientific evidence, suggesting the need for better preparedness. Nevertheless, the views of professionals revealed from our study could help to develop clinical guidelines and regulatory guidance.

Ionizing Radiation Induces Innate Immune Responses in Macrophages by Generation of Mitochondrial Reactive Oxygen Species

During radiotherapy for tumors, the innate immune system also responds to ionizing radiation and induces immune modulation. However, little is known about the molecular mechanisms by which radiation modulates innate immune responses. In this study, we observed that radiation triggered the generation of mitochondrial reactive oxygen species (mROS), leading to innate immune responses in murine bone marrow-derived macrophages (BMDM). Radiation-induced mROS was essential for robust induction of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-12p40 mRNA and protein in BMDM. Exposure to radiation also led to rapid activation of the mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB pathways in BMDM. Notably, radiation-induced MAPK activation and NF-κB signaling were regulated by mROS in macrophages. Additionally, radiation-induced expression of TNF-α, IL-6 and IL-12p40 was dependent on JNK, p38 and NF-κB activation in BMDM. These data suggest a key role for radiation-induced pro-inflammatory responses and activation of the MAPK and NF-κB pathways through a triggering mechanism involving mROS generation.

The Role of Neoadjuvant Chemotherapy in the Treatment of Nasopharyngeal Carcinoma: A Multi-institutional Retrospective Study (KROG 11-06) Using Propensity Score Matching Analysis

Purpose

We compared the treatment results and toxicity in nasopharyngeal carcinoma (NPC) patients treated with concurrent chemotherapy (CCRT) alone (the CRT arm) or neoadjuvant chemotherapy followed by CCRT (the NCT arm).

Materials and Methods

A multi-institutional retrospective study was conducted to review NPC patterns of care and treatment outcome. Data of 568 NPC patients treated by CCRT alone or by neoadjuvant chemotherapy followed by CCRT were collected from 15 institutions. Patients in both treatment arms were matched using the propensity score matching method, and the clinical outcomes were analyzed.

Results

After matching, 300 patients (150 patients in each group) were selected for analysis. Higher 5-year locoregional failure-free survival was observed in the CRT arm (85% vs. 72%, p=0.014). No significant differences in distant failure-free survival (DFFS), disease-free survival (DFS), and overall survival were observed between groups. In subgroup analysis, the NCT arm showed superior DFFS and DFS in stage IV patients younger than 60 years. No significant difference in compliance and toxicity was observed between groups, except the radiation therapy duration was slightly shorter in the CRT arm (50.0 days vs. 53.9 days, p=0.018).

Conclusion

This study did not show the superiority of NCT followed by CCRT over CCRT alone. Because NCT could increase the risk of locoregional recurrences, it can only be considered in selected young patients with advanced stage IV disease. The role of NCT remains to be defined and should not be viewed as the standard of care.

Effects of beta-blockers for congestive heart failure in pediatric and congenital heart disease patients: a meta-analysis of published studies

AIM

The effects of beta-blockers in pediatric and congenital heart disease (CHD) patients suffering from heart failure are controversial. We performed a meta-analysis to determine whether beta-blockers are effective for heart failure in pediatric and CHD patients.

METHODS

We searched for clinical trials focusing on clinical on clinical and ventricular functional/dimensional changes after beta-blocker therapy in PubMed (from its inception to August 2013) and bibliographies of identified studies. Studies investigating any of three beta blockers (carvedilol, bisoprolol, and extended release metoprolol succinate) which are known to be effective in adult patients with heart failure were included.

RESULTS

Of the 158 screened, 17 (N.=476) fulfilled the study criteria and were analyzed. Beta-blockers were associated with significant improvements in left ventricular (LV) ejection fraction (EF) (12.47%; 95% CI, 10.36 to 14.61), fraction shortening (5.75%; 95% CI, 4.42 to 7.08), LV end-diastolic dimension (-2.91 mm; 95% CI, -5.46 to -0.36), and LV systolic dimension (-4.03 mm; 95% CI, -6.81 to -1.25). No significant change in the pooled mean difference of the right ventricular (RV) EF (3.50%; P=0.08) was observed. However, the RV EF in the untreated group showed a deteriorating trend (-3%), which was different from the trend in the treatment group. There was a significant reduction in the incidence of clinical worsening (odds ratio, 2.15; 95% CI, 1.27 to 3.66).

CONCLUSION

Beta-blocker therapy was associated with a significant improvement of echocardiographic parameters in patients with systemic LV failure. However, the use of beta-blockers did not provide significant benefits in terms of improving the EF in patients with RV failure. Nonetheless, beta-blockers may be effective to prevent the clinical deterioration of pediatric and CHD patients with heart failure.

Patterns of care for patients with nasopharyngeal carcinoma (KROG 11-06) in South Korea

PURPOSE

To investigate the patterns of care for patients with nasopharyngeal carcinoma (NPC) in South Korea.

MATERIALS AND METHODS

A multi-institutional retrospective study was performed (Korean Radiation Oncology Group [KROG] 11-06) on a total of 1,445 patients from 15 institutions.

RESULTS

Of the 1,445 patients, more than half were stages III (39.9%) and IV (35.8%). In addition to patterns of care, we also investigated trends over time with the periods 1988-1993, 1994-2002, and 2003-2011. The frequencies of magnetic resonance imaging and positron emission tomography-computed tomography were markedly increased in the third period compared to previous 2 periods. Concurrent chemoradiation (CCRT) was performed on 894 patients (61.9%), neoadjuvant chemotherapy on 468 patients (32.4%), and adjuvant chemotherapy on 366 patients (25.3%). Of stage II-IV patients, CCRT performed on 78.8% in 2003-2011 compared to 15.0% in 1988-1993. For patients treated with CCRT, cisplatin was the most commonly used agent in 81.3% of patients. Over the periods of time, commonly used radiotherapy (RT) techniques were changed from 2-dimensional RT (1988-1993, 92.5%) to 3-dimensional RT (2003-2011, 35.5%) or intensity-modulated RT (IMRT; 2003-2011, 56.5%). Median RT doses given to primary tumors, high-risk lymphatics, and low-risk lymphatics were 70.0 Gy, 58.1 Gy, and 48.0 Gy, respectively. Adoption of IMRT increased the dose per fraction and escalated total radiation dose.

CONCLUSION

Assessment of the patterns of care for NPC patients in South Korea demonstrated that management for NPC including diagnostic imaging, treatment regimen, RT techniques and dose schedule, advanced in accordance with the international guidelines.

Hydroxymethylglutaryl-coenzyme a synthase 2 expression is associated with chemoradiotherapy responses in colorectal cancer

BACKGROUND

Preoperative chemoradiotherapy has become a standard treatment modality for locally advanced rectal cancer. Favorable long-term outcomes have been reported for patients with good responses to chemoradiotherapy. Therefore, predictive factors for chemoradiotherapy responses can be useful for their applicability to risk-adaptive therapy in patients with colorectal cancer.

OBJECTIVE

The aim of this study was to investigate whether hydroxymethylglutaryl-coenzyme A synthase 2, a key enzyme in ketogenesis, is associated with the responses of colorectal cancer cells to chemoradiotherapy.

DESIGN

Hydroxymethylglutaryl-coenzyme A synthase 2 was identified by a 2-dimensional gel electrophoresis -based proteome analysis. It was analyzed in 12 colorectal cancer cells for associations with radiation or 5-fluorouracil susceptibility by Western blotting, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium Bromide assay, and small interfering RNA transfection. Then, tumor tissues obtained from 45 patients with rectal cancer before chemoradiotherapy were analyzed by Western blotting for associations with chemoradiotherapy responses.

RESULTS

Expression of hydroxymethylglutaryl-coenzyme A synthase 2 was significantly correlated with intrinsic radiation resistance of 12 cancer cells. Hydroxymethylglutaryl-coenzyme A synthase 2 expression was significantly affected by treatment with either 5-fluorouracil or radiation depending on cell types. The artificial suppression of hydroxymethylglutaryl-coenzyme A synthase 2 did not result in the change of chemoradiation susceptibility in colorectal cancer cells. Nevertheless, in multivariate analyses, hydroxymethylglutaryl-coenzyme A synthase 2 expression in rectal cancer tissues was shown to be a significant predictive factor for chemoradiotherapy responses, as evaluated in terms of tumor regression grade and downstaging.

LIMITATIONS

Overall findings in vitro showed that the expression level of hydroxymethylglutaryl-coenzyme A synthase 2 was highly variable depending on colon cancer cell types, and it cannot directly affect on chemoradiotherapy responses. The molecular mechanism underpinning the association between hydroxymethylglutaryl-coenzyme A synthase expression and chemoradiotherapy responses needs to be elucidated through future research.

CONCLUSIONS

Hydroxymethylglutaryl-coenzyme A synthase 2 was associated with the effects of chemoradiotherapy on human colorectal cancer cells. Pretreatment levels of hydroxymethylglutaryl-coenzyme A synthase 2 in rectal cancer may be useful in predicting the responses to chemoradiotherapy.

Retrospective analysis of treatment outcomes after postoperative chemoradiotherapy in advanced gastric cancer

PURPOSE

To evaluate retrospectively the survival outcome, patterns of failure, and complications in patients treated with postoperative chemoradiotherapy (CRT) in advanced gastric cancer.

MATERIALS AND METHODS

Between January 2000 and December 2006, 80 patients with advanced gastric cancer who received postoperative concurrent CRT were included. Pathological staging was IB-II in 9%, IIIA in 38%, IIIB in 33%, and IV in 21%. Radiotherapy consisted of 45 Gy of radiation. Concurrent chemotherapy consisted of a continuous intravenous infusion of 5-fluorouracil and leucovorin on the first 4 days and last 3 days of radiotherapy.

RESULTS

The median follow-up period was 48 months (range, 3 to 83 months). The 5-year overall survival, disease-free survival, and locoregional recurrence-free survivals were 62%, 59%, and 80%, respectively. In the multivariate analysis, significant factors for disease-free survival were T stage (hazard ratio [HR], 0.278; p = 0.038), lymph node dissection extent (HR, 0.201; p = 0.002), and maintenance oral chemotherapy (HR, 2.964; p = 0.004). Locoregional recurrence and distant metastasis occurred in 5 (6%) and 18 (23%) patients, respectively. Mixed failure occurred in 10 (16%) patients. Grade 3 leukopenia and thrombocytopenia were observed in 4 (5%) and one (1%) patient, respectively. Grade 3 nausea and vomiting developed in 8 (10%) patients. Intestinal obstruction developed in one (1%).

CONCLUSION

The survival outcome of the postoperative CRT in advanced gastric cancer was similar to those reported previously. Our postoperative CRT regimen seems to be a safe and effective method, reducing locoregional failure without severe treatment toxicity in advanced gastric cancer patients.

ID3 mediates X-ray-induced apoptosis of keratinocytes through the regulation of β-catenin

BACKGROUND

Ionizing radiation is used to treat many of cancers, however, it also produces unwanted side effect on normal tissues, such as radiodermatitis. We previously established an animal model for radiodermatitis, and found that X-ray irradiation induced the expression of ID3 in hairless mouse skin by cDNA microarray.

OBJECTIVE

The aim of this study is to investigate the functional role of ID3 in X-ray irradiated keratinocytes.

METHODS

Immunohistochemistry, RT-PCR and Western blot were performed to demonstrate the ID3 induction by X-ray irradiation. HaCaT keratinocytes were transduced with the recombinant adenovirus expressing HA-ID3, and then effects on apoptosis were analyzed.

RESULTS

X-ray irradiation increased markedly the ID3 protein level in epidermis of mouse skin. X-ray irradiation also induced the expression of ID3 in HaCaT keratinocytes cultured in vitro, at both mRNA and protein levels. When ID3 was overexpressed by recombinant adenovirus, apoptosis of keratinocytes were induced even in the absence of X-ray irradiation. Furthermore, overexpression of ID3 sensitized X-ray-induced apoptosis. Interestingly, X-ray irradiation significantly reduced the endogenous β-catenin level, which was related with induction of apoptosis. Similarly, overexpression of ID3 led to remarkable reduction in β-catenin level.

CONCLUSION

These results suggest that ID3 plays a role as an apoptosis inducer in response to X-ray irradiation via the regulation of endogenous β-catenin level.

Differential gene expression profiles of radioresistant non-small-cell lung cancer cell lines established by fractionated irradiation: tumor protein p53-inducible protein 3 confers sensitivity to ionizing radiation

PURPOSE

Despite the widespread use of radiotherapy as a local and regional modality for the treatment of cancer, some non-small-cell lung cancers commonly develop resistance to radiation. We thus sought to clarify the molecular mechanisms underlying resistance to radiation.

METHODS AND MATERIALS

We established the radioresistant cell line H460R from radiosensitive parental H460 cells. To identify the radioresistance-related genes, we performed microarray analysis and selected several candidate genes.

RESULTS

Clonogenic and MTT assays showed that H460R was 10-fold more resistant to radiation than H460. Microarray analysis indicated that the expression levels of 1,463 genes were altered more than 1.5-fold in H460R compared with parental H460. To evaluate the putative functional role, we selected one interesting gene tumor protein p53-inducible protein 3 (TP53I3), because that this gene was significantly downregulated in radioresistant H460R cells and that it was predicted to link p53-dependent cell death signaling. Interestingly, messenger ribonucleic acid expression of TP53I3 differed in X-ray-irradiated H460 and H460R cells, and overexpression of TP53I3 significantly affected the cellular radiosensitivity of H460R cells.

CONCLUSIONS

These results show that H460R may be useful in searching for candidate genes that are responsible for radioresistance and elucidating the molecular mechanism of radioresistance.

Interstitial fluid pressure as a prognostic factor in cervical cancer following radiation therapy

PURPOSE

To investigate tumor interstitial fluid pressure as a prognostic factor for recurrence-free survival in patients with cervical cancer following radiation therapy.

EXPERIMENTAL DESIGN

Tumor interstitial fluid pressure was measured in 55 cervical cancer patients who received radiation therapy between August 1998 and September 2002. Interstitial fluid pressure measurements were made before radiation therapy (pre-radiation therapy interstitial fluid pressure) and after a median of 28.8 Gy in 16 fractions (range, 25.2-30.6 Gy in 14-17 fractions) of radiation therapy (mid-radiation therapy interstitial fluid pressure), using a modified wick-in-needle technique. Median follow-up was 74 months (range, 2-118 months). The Kaplan-Meier method with the log-rank test and Cox's proportional hazard model were used in univariate and multivariate analyses, respectively, of prognostic factors for recurrence-free survival.

RESULTS

Median pre-radiation therapy and mid-radiation therapy interstitial fluid pressure were 29.0 mm Hg (range, 4.0-93.9 mm Hg) and 20.0 mm Hg (range, -1.2 to 29.6 mm Hg), respectively (P = 0.001). Pre-radiation therapy interstitial fluid pressure was significantly higher in adenocarcinomas than squamous cell carcinomas (P = 0.028). Significant reduction of interstitial fluid pressure was noted only in patients with complete responses (P = 0.002), and mid-radiation therapy interstitial fluid pressure was significantly lower in patients with complete responses (P = 0.036). In the multivariate analysis including interstitial fluid pressures and clinical variables, pre-radiation therapy interstitial fluid pressure was an independent prognostic factor for local and distant recurrence-free survival (P = 0.001 and 0.027, respectively).

CONCLUSIONS

Mid-radiation therapy interstitial fluid pressure measurement may be useful in predicting radiation therapy responses, and pre-radiation therapy interstitial fluid pressure was a significant prognostic factor for local and distant relapse-free survival in patients with cervical cancer after radiation therapy.

Anti-apoptotic role of S100A8 in X-ray irradiated keratinocytes

BACKGROUND

Ionizing radiation is used to treat a lot of cancers, however, it also produced unwanted side effect on normal tissues, such as radiodermatitis. We previously established an animal model for radiodermatitis, and identified many of radiation-induced genes by cDNA microarray. Of the candidates, we chose S100A8 gene for a further study.

OBJECTIVE

The aim of this study is to investigate the functional role of S100A8 in X-ray irradiated keratinocytes.

METHODS

RT-PCR and immunohistochemistry were performed to demonstrate the S100A8 induction by X-ray irradiation. HaCaT keratinocytes were transduced with the recombinant adenovirus expressing GFP-S100A8, and then effects on cell cycle and apoptosis were analyzed using flow cytometry and Western blot.

RESULTS

X-ray irradiation markedly induced S100A8 expression in the hyperplastic epidermis of mouse. Overexpression of S100A8 by adenoviral transduction led to the enhancement of cell proliferation in the absence and/or presence of X-ray irradiation, as compared with Ad/GFP control group. Furthermore, overexpression of S100A8 significantly protected the X-ray-induced apoptosis.

CONCLUSION

These results suggest that S100A8 have an anti-apoptotic role in X-ray irradiated keratinocytes.

Cyclooxygenase-2 expression as a predictor of para-aortic lymph node recurrence in uterine cervical cancer

PURPOSE

The overexpression of cyclooxygenase-2 (COX-2) is associated with a worse prognosis and the development of distant metastases in cervical cancer. This matched-pair analysis examined whether COX-2 expression is associated with para-aortic lymph node (PALN) recurrence in uterine cervical cancer treated with radiotherapy (RT).

METHODS AND MATERIALS

For this study, we matched 20 patients with PALN recurrence after definitive or postoperative RT by stage with 20 others who did not have PALN recurrence. Of the 20 patients with PALN recurrence, definitive or postoperative RT was performed in 11 and 9 patients, respectively. COX-2 expression was assessed immunohistochemically using a mouse monoclonal antibody on formalin-fixed paraffin-embedded tumor specimens taken before RT. A logistic regression model was used to predict for PALN recurrence.

RESULTS

COX-2 was expressed in 28 (70%) of the 40 patients. The staining intensity was as follows: weak in 19 (47%), moderate in 6 (15%), and strong in 3 (8%) patients. The patients with PALN recurrence had much greater expression of COX-2 (17 patients, 85%) than did the control group (11 patients, 55%; p = 0.04). Strong staining intensity of COX-2 was seen only in the PALN recurrence group. The statistically significant factors associated with PALN recurrence were positive pelvic lymph nodes (odds ratio, 7.61; 95% confidence interval, 1.55-37.37; p = 0.01) and COX-2 expression (odds ratio, 1.47; 95% confidence interval, 1.04-2.09; p = 0.03).

CONCLUSION

Our findings suggest that COX-2 overexpression in the initial tumor tissue might be associated with PALN recurrence after RT in cervical cancer patients.

Epidural naloxone reduces postoperative nausea and vomiting in patients receiving epidural sufentanil for postoperative analgesia

BACKGROUND

Epidural opioids have excellent analgesic properties, but their side-effects limit their use in patient-controlled epidural analgesia. This study was designed to evaluate the effect of epidural naloxone on the side-effects of sufentanil, focusing on postoperative nausea and vomiting (PONV) in patients undergoing total knee replacement (TKR).

METHODS

After obtaining Institutional Review Board approval and informed consent, 50 patients undergoing unilateral TKR were randomly assigned to receive either sufentanil in ropivacaine alone (Group C, n = 25) or the same solution with naloxone (Group N, n = 25) for their postoperative epidural analgesia. Episodes of PONV and five-point-scaled nausea scores were evaluated at 6, 12, and 24 h after epidural analgesia was started. Visual analogue scale (VAS) score for pain and the incidence of sedation, pruritus, hypotension, and respiratory depression were also evaluated at each of three time points.

RESULTS

The nausea score in Group N was significantly lower than that in Group C. The VAS pain score at rest and on movement were significantly lower in Group N than in Group C at 24 h. Other opioid-induced side-effects were not significantly different.

CONCLUSIONS

Epidural naloxone was effective in reducing PONV induced by epidural sufentanil and additionally enhanced the analgesic effect. Therefore, concomitant infusion of a small dose of epidural naloxone should be considered to reduce PONV, especially in patients at greater risk for PONV.

Epidermal growth factor receptor as a predictor of tumor downstaging in locally advanced rectal cancer patients treated with preoperative chemoradiotherapy

PURPOSE

To examine retrospectively whether levels of epidermal growth factor receptor (EGFR) expression can predict tumor downstaging after preoperative chemoradiotherapy in patients with locally advanced rectal cancer.

METHODS AND MATERIALS

A total of 183 patients with rectal cancer (cT3-T4 or N+) were enrolled in this study. Preoperative chemoradiotherapy consisted of 50.4 Gy of pelvic radiation with concurrent 5-fluorouracil and leucovorin bolus intravenous chemotherapy in 94 patients or oral capecitabine and leucovorin in 89 patients. EGFR expression in pretreatment paraffin-embedded tumor biopsy specimens was assessed by immunohistochemistry. EGFR expression was determined from the intensity and extent of staining. Tumor downstaging was defined as a reduction of at least one T-stage level.

RESULTS

Tumor downstaging occurred in 97 patients (53%), and the tumors showed a pathologic complete response in 27 patients (15%). Positive EGFR expression was observed in 140 (76%) of 183 patients. EGFR expression levels were low in 113 patients (62%) and high in 70 patients (38%). On logistic regression analysis, the significant predictive factor for increased tumor downstaging was a low level of EGFR expression and preoperative chemotherapy using oral capecitabine (odds ratio, 0.437; p = 0.012 vs. odds ratio, 3.235; p < 0.001, respectively).

CONCLUSION

A high level of EGFR expression may be a significant predictive molecular marker for decreased tumor downstaging after preoperative chemoradiotherapy in locally advanced rectal cancer.

Expression profiling of radiation-induced genes in radiodermatitis of hairless mice

BACKGROUND

Radiation induces many cellular events leading to radiodermatitis.

OBJECTIVES

The aim of this study was to establish a radiodermatitis model using experimental animals, and to examine the expression profile of radiation-induced genes.

METHODS

Hairless mice were irradiated on the dorsal skin; then total RNAs were isolated and microarray hybridizations were performed.

RESULTS

Irradiation with a total of 40 Gy (10 Gy day-1 for four consecutive days) provokes radiodermatitis in the hairless mouse. After microarray analysis, 130 genes that showed upregulation by radiation were selected and organized into four different clusters, depending on the time-kinetic pattern. Classification of these genes into several functional categories revealed that various biological processes were globally affected by radiation. These include transcription regulation, signal transduction, cell communication, cell death regulation and metabolism.

CONCLUSIONS

These results demonstrate the complexity of the transcriptional profile of the radiation response, providing important clues on which to base further investigations of the molecular events underlying radiodermatitis.

Thiobarbituric Acid Reactive Substances and Volatile Compounds in Chicken Breast Meat Infused with Plant Extracts and Subjected to Electron Beam Irradiation

The effect of irradiation on thiobarbituric acid reactive substances (TBARS) and volatile compounds in raw and cooked nonirradiated and irradiated chicken breast meat infused with green tea and grape seed extracts was investigated. Chicken breast meat was vacuum infused with green tea extract (3,000 ppm), grape seed extract (3,000 ppm), or their combination (at a total of 6,000 ppm), irradiated with an electron beam, and stored at 5 degrees C for 12 d. The targeted irradiation dosage was 3.0 kGy and the average absorbed dosage was 3.12 kGy. Values of TBARS and volatile compound contents of raw and cooked chicken meat were determined during the 12-d storage period. Thiobarbituric acid reactive substances values ranged from 15.5 to 71.4 mg of malondialdehyde/kg for nonirradiated raw chicken and 17.3 to 80.1 mg of malondialdehyde/kg for irradiated raw chicken. Values for cooked chicken ranged from 31.4 to 386.2 and 38.4 to 504.1 mg of malondialdehyde/kg for nonirradiated and irradiated chicken, respectively. Irradiation increased TBARS and hexanal values of controls and meat infused with plant extracts. Hexanal had the highest intensity of volatiles followed by pentanal and other volatiles. Cooking the samples significantly (P < 0.05) increased the amounts of TBARS and volatiles. Addition of plant extracts decreased the amount of TBARS as well as hexanal and pentanal values. Although irradiation increases lipid oxidation, infusion of chicken meat with plant extracts could reduce lipid oxidation caused by irradiation.

Epidermal growth factor receptor as a prognostic factor in locally advanced rectal-cancer patients treated with preoperative chemoradiation

PURPOSE

We investigated the prognostic value of epidermal growth factor receptor (EGFR) expression in pretreatment biopsy specimens from patients with locally advanced rectal cancer treated with preoperative chemoradiation.

METHODS AND MATERIALS

Pretreatment biopsy specimens from 92 patients with locally advanced rectal cancer were examined for EGFR expression by immunohistochemistry. EGFR expression was assessed by immunoreactive score (IRS). The prognostic value of EGFR expression was evaluated according to the level of EGFR expression.

RESULTS

Epidermal growth factor receptor expression was positive in 65 patients (71%). EGFR expression levels were low (IRS 0 to 5) in 83 patients (90%) and high (IRS 6 to 7) in 9 patients (10%). A high level of EGFR expression was statistically significant for shorter overall survival (p = 0.013), disease-free survival (p = 0.002), and distant metastasis-free survival (p = 0.003), as compared with a low level of expression in univariate analysis. Grouping based on positive or negative EGFR expression did not represent prognostic significance for survival. In multivariate analysis, high EGFR expression was an independent prognostic factor for decreased disease-free survival (relative risk 2.4, p = 0.041) and distant metastasis-free survival (relative risk 2.6, p = 0.04).

CONCLUSIONS

Our results suggest that high level of EGFR expression in a pretreatment biopsy specimen may be a significant adverse prognostic factor for disease-free survival and distant metastasis-free survival.

AtBAG6, a novel calmodulin-binding protein, induces programmed cell death in yeast and plants

Calmodulin (CaM) influences many cellular processes by interacting with various proteins. Here, we isolated AtBAG6, an Arabidopsis CaM-binding protein that contains a central BCL-2-associated athanogene (BAG) domain. In yeast and plants, overexpression of AtBAG6 induced cell death phenotypes consistent with programmed cell death (PCD). Recombinant AtBAG6 had higher affinity for CaM in the absence of free Ca2 + than in its presence. An IQ motif (IQXXXRGXXXR, where X denotes any amino-acid) was required for Ca2 +-independent CaM complex formation and single amino-acid changes within this motif abrogated both AtBAG6-activated CaM-binding and cell death in yeast and plants. A 134-amino-acid stretch, encompassing both the IQ motif and BAG domain, was sufficient to induce cell death. Agents generating oxygen radicals, which are known to be involved in plant PCD, specifically induced the AtBAG6 transcript. Collectively, these results suggest that AtBAG6 is a stress-upregulated CaM-binding protein involved in plant PCD.

Comparison of the efficacy of oral capecitabine versus bolus 5-FU in preoperative radiotherapy of locally advanced rectal cancer

The effects of treatment with oral capecitabine vs. bolus 5-FU, administered concurrently with preoperative radiotherapy, were compared in the treatment of locally advanced rectal cancer (LARC). One hundred and twenty-seven patients with LARC received concurrent preoperative chemoradiation using two cycles bolus 5-FU (500 mg/m2/day) plus leucovorin (LV, 20 mg/m2/day) (Group I). Another LARC group received concurrent chemoradiation using two cycles 1,650 mg/m2/day of oral capecitabine and 20 mg/m2/day of LV (Group II, 97 patients). Radiation was delivered to the primary tumor at 50.4 Gy in both groups. Definitive surgery was performed 6 weeks after the completion of chemoradiation. A pathologic complete remission was achieved in 11.4% of patients in Group I and in 22.2% of patients in Group II (p= 0.042). The down-staging rates of the primary tumor and lymph nodes were 39.0/ 68.7% in Group I and 61.1/87.5% in Group II (p=0.002/0.005). Sphincter-preserving surgery was possible in 42.1% of patients in Group I and 66.7% of those in Group II (p=0.021). Grade 3 or 4 leucopenia, diarrhea, and radiation dermatitis were statistically more prevalent in Group I than in Group II, while the opposite was true for grade 3 hand-foot syndrome. Preoperative chemoradiation using oral capecitabine was better tolerated than bolus 5-FU and was more effective in the promotion of both down-staging and sphincter preservation in patients with LARC.

Treatment outcomes of three-dimensional conformal radiotherapy for stage III non-small cell lung cancer

PURPOSE

To evaluate the treatment outcomes of the three-dimensional conformal radiotherapy (3D-CRT), in conjunction with induction chemotherapy, for the treatment of stage III non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Between November 1998 and March 2003, 22 patients with histologically proven, clinical stage III NSCLC, treated with induction chemotherapy, followed by 3D-CRT, were retrospectively analyzed. There were 21 males (96%) and 1 female (4%), with a median age of 68.5 (range, 42 approximately 79). The clinical cancer stages were IIIA and IIIB in 41 and 59%, respectively. The histologies were squamous cell carcinoma, adenocarcinoma and others in 73, 18 and 9%, respectively. Twenty patients (91%) received induction chemotherapy before radiation therapy. The majority of the chemotherapy regimen consisted of cisplatin and gemcitabine. Radiation was delivered with conventional anteroposterior/posteroanterior fields for 36 Gy, and then 3D-CRT was performed. The total radiation dose was 70.2 Gy. The median follow-up period was 17 months (range, 4~59 months).

RESULTS

The median overall survival was 19 months. The two and four-year overall survival rates were 37.9 and 30.3%, respectively. The median progression-free survival was 21 months. The two and four-year progression-free survival rates were 42.1 and 21%, respectively. The prognostic factors for overall survival by a univariate analysis were age, histology and T stage (p<0.05). Acute radiation toxicities, as evaluated by the RTOG toxicity criteria, included two cases of grade 3 lung toxicity and one case of grade 2 esophagus toxicity.

CONCLUSION

The radiation dose could be increased without a significant increment in the acute toxicities when using 3D-CRT. It also seems to be a safe, well-tolerated and effective treatment modality for stage III NSCLC.

Antibodies as drug carriers III: design of oligonucleotides with enhanced binding affinity for immunoglobulin G

PURPOSE

To understand the structural requirements in designing epitope-bearing oligonucleotides with high antibody-binding affinity.

METHODS

Binding affinity (KA) and stoichiometry (n) of dinitrophenyl (DNP)-derivatized model 27-mer oligonucleotides (ODNs), GGG(AAA)7GGG, to monoclonal anti-trinitrophenyl (TNP) antibodies were determined using isothermal titration calorimetry (ITC). Structural variations were made in the ODNs to assess the effects of antigenic valence, epitope density, inter-epitope linker length, and linker flexibility. Binding isotherms were fitted with a single binding-site model to obtain K(A) and n, from which changes in Gibbs free energy (deltaG(0)), entropy (deltaS(0)), and enthalpy (deltaH(0)) were derived.

RESULTS

As expected, ligands displaying increased epitope density showed increases in K(A): for example, K(A) for (DNP)2-Cys is 3.3-fold greater than that for DNP-Lys. Introduction of multiple DNP groups via long and flexible linkers to one end of the 27-mer ODN resulted in a bivalent behavior with n value of 1. A bivalent ligand, derivatized at both ends with a long and flexible linker, failed to form an immune complex when hybridized to its antisense strand, presumably due to intercalation of the DNP moiety to the double strand. ODNs derivatized with flexible linkers exhibited a higher K(A) than those with a rigid linker. Ligands with flexible inter-epitope linkers measuring distances of 110, 60, and 40 angstroms yielded 13-, 30-, and 13-fold increases in K(A), respectively. The combination of these factors; namely, bivalence, flexible inter-epitope linkers, and optimal inter-epitope distance, resulted in an overall 66-fold increase in K(A). Thermodynamic analysis of binding indicates that the formation of high-affinity ODN-IgG complexes was a spontaneous and exothermic event, characterized by large negative deltaS degrees, deltaH degrees, and deltaG degrees values.

CONCLUSIONS

All four strategies tested during this investigation, namely bivalence, epitope density, inter-epitope linker flexibility, and optimal inter-epitope distance, proved to be useful in improving the binding affinity of DNP-labeled ODNs to anti-TNP IgG. The final ODN design incorporating these strategies will be used in testing the systemic pharmacokinetic advantage gained from complexing such ODNs to IgG.

Detection of RTP801, a gene that is differentially expressed in irradiated HeLa cells

PURPOSE

To quantify the effects of irradiation on the expression levels of a differentially expressed gene, RTP801, in HeLa cells.

MATERIALS AND METHODS

Total RNA was isolated from irradiated and non-irradiated HeLa cells. A subtraction library was constructed, from which 88 random clones were screened. The expression patterns of one clone, detected by reverse Northern blotting, were quantified by real time RT-PCR, using CYBR green I dye.

RESULTS

RTP801, a hypoxia-inducible factor-I-responsive gene, was identified as a differentially expressed gene in HeLa cells exposed to X-ray. Real time RT-PCR showed that the mRNA levels of RTP801 were greatly diminished by radiation.

CONCLUSIONS

These results suggest that down-regulation of hypoxia-inducible factor-I-responsive genes, such as RTP801, in irradiated HeLa cells may result in reductions in the radiotherapy resistance of tumor cells.

Inactivation of pathogenic bacteria by cucumber volatiles (E,Z)-2,6-nonadienal and (E)-2-nonenal

The effects of (E,Z)-2,6-nonadienal (NDE) and (E)-2-nonenal (NE) on Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium were investigated. A suspension of each organism of 6 to 9 log CFU/ml was incubated for 1 h at 37 degrees C in brain heart infusion solution that contained 0 to 500 or 1,000 ppm of NDE or NE. Depending on concentration, exposure to either NDE or NE caused a reduction in CFU of each organism. Treatment with 250 and 500 ppm NDE completely eliminated viable B. cereus and Salmonella Typhimurium cells, respectively. L. monocytogenes was the most resistant to NDE, showing only about a 2-log reduction from exposure to 500 ppm for 1 h. Conversely, this concentration of NDE caused a 5.8-log reduction in E. coli O157:H7 cells. NE was also effective in inactivating organisms listed above. A higher concentration of NE, 1,000 ppm, was required to kill E. coli O157:H7, L. monocytogenes, or Salmonella Typhimurium compared with NDE. In conclusion, both NDE and NE demonstrated an apparent bactericidal activity against these pathogens.

Isocenter accuracy in frameless stereotactic radiotherapy using implanted fiducials

PURPOSE

The stereotactic radiotherapy (SRT) system verifies isocenter accuracy in patient space. In this study, we evaluate isocenter accuracy in frameless SRT using implanted cranial gold markers.

MATERIALS AND METHODS

We performed frameless SRT on 43 intracranial tumor patients between August 1997 and December 2000. The treatment technique was determined by the tumor shape and volume, and by the location of critical organs. The coordinates of anterior-posterior and lateral port film were inputted to ISOLOC software, which calculated (1) the couch moves translation distance required to bring the target point to the isocenter, and (2) the intermarker distance comparisons between the CT study and the treatment machine films. We evaluated the isocenter deviation based on the error between orthogonal film target coordinates and isocenter coordinates.

RESULTS

The mean treatment isocenter deviations (x, y, z) were -0.03, 0.14, and -0.04 mm, respectively. The systematic component isocenter standard deviations were 0.28, 0.31, and 0.35 mm (1 SD), respectively, and the random component isocenter standard deviations were 0.53, 0.52, and 0.50 mm (1 SD), respectively.

CONCLUSIONS

The isocenter accuracy in the frameless SRT-implanted fiducial system is highly reliable and is comparable to that of other stereotactic radiosurgery systems.

Hyperfractionated radiotherapy with concurrent chemotherapy for para-aortic lymph node recurrence in carcinoma of the cervix

PURPOSE

To evaluate efficacy, toxicity, and patterns of relapse in patients treated with hyperfractionated radiotherapy (HFRT) with concurrent chemotherapy for para-aortic lymph node (PALN) recurrence of cervical carcinoma.

METHODS AND MATERIALS

Between September 1997 and October 2000, 12 cervical carcinoma patients with isolated PALN recurrence who had previously received radical or postoperative radiotherapy were treated with HFRT and concurrent chemotherapy. The initial FIGO stage was Stage IB in 4 (33%) patients, Stage IIA in 2 (17%), and Stage IIB in 6 (50%). The radiation field encompassed the gross recurrent PALN with the superior margin at the upper end of the T12 body and the inferior margin between L5 and S1. The fractionated dose was 1.2 Gy in 2 daily fractions, and the median total dose was 60 Gy. The weekly concurrent chemotherapy consisted of paclitaxel in 11 patients and cisplatin in 1. The median number of cycles of chemotherapy was 5.

RESULTS

The latent period to PALN recurrence from the time of initial treatment for all patients ranged from 2 to 92 months (median: 12 months). One month after treatment, the clinical tumor response evaluated was complete in 33% (4/12) and partial in 67% (8/12). The 3-year overall survival rate and median survival were 19% and 21 months, respectively. The latent period to PALN recurrence was the only significant prognostic factor; the median survival of patients who relapsed in < or =24 months from the initial treatment of cervical carcinoma was 13 months vs. 45 months for those relapsed at >24 months (p = 0.026). Grade 3-4 hematologic toxicity developed in 2 patients. Six (50%) patients experienced Grade 2 nausea. There were no late gastrointestinal or neurologic complications during the follow-up period. Subsequent distant metastases after PALN treatment developed in 58% (7/12).

CONCLUSION

HFRT of 60 Gy to PALN with concurrent chemotherapy could be regarded as an effective treatment modality without significant acute or late toxicity. Patients with a latent period >24 months until PALN recurrence had a more favorable survival rate than those with a latent period </=24 months. Subsequent distant metastasis after PALN recurrence was the main cause of death and is a problem to overcome in the future.

AlphaIIbbeta3-mediated outside-in signaling induced by the agonist peptide LSARLAF utilizes ADP and thromboxane A2 receptors to cause alpha-granule secretion by platelets

The peptide LSARLAF (LSA) causes alphaIIbbeta3-dependent platelet activation that results in alpha-granule secretion and aggregation. LSARLAF-induced, alphaIIbbeta3-mediated outside-in signaling causing alpha-granule secretion and platelet aggregation was studied using washed mouse platelets. ADP receptor antagonists, enzyme inhibitors, normal platelets and platelets from mice that lack either Galphaq or thromboxane (Tx) A2 receptors were used for this investigation. The results demonstrate that LSA-induced alphaIIbbeta3-mediated signaling producing aggregation of washed platelets is mediated through the release of ADP and thromboxane, which cause alpha-granule release by mediating their effects though Galphaq and/or Gi depending on the level of LSA used to activate the platelets. Specifically, alphaIIbbeta3 elicited aggregation of washed platelets in response to a low level of LSA requires signaling through the ADP receptor P2Y1 and Galphaq, and the ADP receptor P2Y12 and Gi as well as TxA2 receptors. However, this aggregation is independent of Galphaq and TxA2 signaling in response to high LSA concentrations, but is dependent on ADP signaling through its receptor P2Y12, and therefore presumably Gi, regardless of the level of LSA used to activate the platelets. PKC function is required for ADP secretion and the subsequent signaling through P2Y12 regardless of the level of LSA used to activate the platelets. The end point of the LSA-induced alphaIIbbeta3-mediated signaling characterized in this study is alpha-granule secretion, which provides the fibrinogen required for aggregation of washed platelets.

Preoperative chemoradiation using oral capecitabine in locally advanced rectal cancer

PURPOSE

Capecitabine (Xeloda) is a new orally administered fluoropyrimidine carbamate that was rationally designed to exert its effect by tumor-selective activation. We attempted to evaluate the efficacy and toxicity of preoperative chemoradiation using capecitabine in locally advanced rectal cancer.

METHODS AND MATERIALS

Between July 1999 and March 2001, 45 patients with locally advanced rectal cancer (cT3/T4 or N+) were treated with preoperative chemoradiation. Radiation of 45 Gy/25 fractions was delivered to the pelvis, followed by a 5.4 Gy/3 fractions boost to the primary tumor. Chemotherapy was administered concurrent with radiotherapy and consisted of 2 cycles of 14-day oral capecitabine (1650 mg/m(2)/day) and leucovorin (20 mg/m(2)/day), each of which was followed by a 7-day rest period. Surgery was performed 6 weeks after the completion of chemoradiation.

RESULTS

Thirty-eight patients received definitive surgery. Primary tumor and node downstaging occurred in 63% and 90% of patients, respectively. The overall downstaging rate, including both primary tumor and nodes, was 84%. A pathologic complete response was achieved in 31% of patients. Twenty-one patients had tumors located initially 5 cm or less from the anal verge; among the 18 treated with surgery, 72% received sphincter-preserving surgery. No Grade 3 or 4 hematologic toxicities developed. Other Grade 3 toxicities were as follows: hand-foot syndrome (7%), fatigue (4%), diarrhea (4%), and radiation dermatitis (2%).

CONCLUSION

These preliminary results suggest that preoperative chemoradiation with capecitabine is a safe, well-tolerated, and effective neoadjuvant treatment modality for locally advanced rectal cancer. In addition, this preoperative treatment has a considerable downstaging effect on the tumor and can increase the possibility of sphincter preservation in distal rectal cancer.

Cold accumulation of SCOF-1 transcripts is associated with transcriptional activation and mRNA stability

Cold acclimation enhances the transcription of several cold regulated (COR) genes. However, little is known about whether the elevation of the transcriptional level of the COR genes is due to transcriptional activation, or mRNA stability by a low temperature. Recently, we cloned a novel cold-inducible zinc finger protein gene from soybean, SCOF-1, which may function as a positive regulator of the COR gene expression . Here we report that the elevation of the SCOF-1 transcript level by cold stress is associated with both transcriptional activation and post-transcriptional mRNA stability under a low temperature. A nuclear run-on assay reveals that cold acclimation elevates the SCOF-1 transcript about three-fold compared to that of non-acclimated soybean nuclei. Furthermore, SCOF-1 transcripts increased substantially by a low temperature in transgenic tobacco plants that constitutively expressed SCOF-1 under the control of a constitutive cauliflower mosaic virus (CaMV) 35S promoter. When a transcription inhibitor, cordycepin, was treated with the deacclimating soybean cell, the decay level of the SCOF-1 transcripts was delayed significantly. This suggests that it may affect de novo protein synthesis, which degrades the SCOF-1 mRNA at room temperature. In addition, a secondary structure may be involved in the mRNA stability of SCOF-1 under a low temperature.

Quantitation of intracellular concentration of a delivered morpholino oligomer by capillary electrophoresis-laser- induced fluorescence: correlation with upregulation of luciferase gene expression

Antisense oligonucleotides have shown great promise over the past several years as viable drugs to combat various forms of cancer and viral diseases. However, quantitative detection to monitor cellular association is difficult using conventional methods such as radiolabeling of the oligonucleotide or fluorescence confocal microscopy. In this paper quantitation of intracellular concentration of the morpholino oligonucleotide is investigated using capillary electrophoresis coupled with laser-induced fluorescence detection (CE-LIF). HeLa cells, which produce luciferase as the antisense oligomer enters the cell, were scrape-loaded with varying concentrations of the morpholino antisense. The intracellular antisense concentration measured by CE-LIF was found to correlate with those obtained with the cellular functional assay based on upregulation of luciferase. Intracellular concentrations of the antisense were found to be in the range of 6 to 29 nmol/g total cell protein, depending on the amounts that were scrape-loaded. To our best knowledge, this is the first reported quantitative correlation between delivered antisense concentration in a cell extract and the subsequent antisense upregulation of gene expression.

Redox changes accompanying the degradation of seed storage proteins in germinating rice

The mobilization of storage proteins (glutelins) in germinating rice seeds was accompanied by an ordered sequential combination of proteolysis and reduction of disulfide groups. Mobilization was followed by application of non-reducing/reducing two dimensional-PAGE after monobromobimane labeling of the sulfhydryl groups of the proteins in intact seeds.

Antibodies as drug carriers. II. For proteins

PURPOSE

To evaluate the potential use of antibodies as a carrier for monovalent protein haptens.

METHODS

A single -SH functionality present in the human IgG light chain was fluoresceinated. This conjugate, FL-LC, was treated with pepsin to obtain FL conjugate of half light chain, FL-(LC)1/2, of MW 11 kDa. These two were radiolabeled using [3H]-propionic acid N-hydroxysuccinimide ester, and administered via tail vein to FL-immunized or mock-immunized mice. The blood radioactivity was measured over a 72-h period. Attempts were made to measure the affinity constant for the interaction between the conjugates and anti-FL antibodies by fluorescence quenching, surface plasmon resonance spectroscopy, and competitive ELISA.

RESULTS

All of the three methods used produced supportive, if not conclusive, evidence of decreased binding affinity with increased conjugate size. Subsequent to tail-vein injection to FL-immunized mice, FL-LC showed approximately 4-fold smaller volume of distribution than mock-immunized mice: 0.041 +/- 0.005 vs. 0.16 +/- 0.02 mL/g. Corresponding values for FL-(LC)1/2, were significantly larger: 0.070 +/-0.013 and 0.30 +/- 0.02 mL/g, respectively. Compared with a small FL conjugate of ethanolamine, FL-EA, we studied earlier, the dose-normalized concentrations of the protein conjugates started at a higher level but declined more rapidly with time. In mock-immunized mice, the radioactivity disappeared very rapidly after administration, followed by an extremely slow decline with half-life close to 60 h. Evidence is provided to support that the radiolabel dissociated in the kidney, however, binding to anti-FL antibodies greatly stabilized the conjugate.

CONCLUSIONS

Based on an entropic principle alone the affinity of monovalent hapten-antibody interaction is expected to diminish with increase in hapten size. As such, the size of a hapten should be an important determinant of its pharmacokinetics in animals harboring antibodies that recognize the hapten. Relative to what was observed with small MW FL-EA, the protein conjugates showed substantially sustained circulation as a result of antibody binding, but this effect was diminished at later time points. Both affinity and pharmacokinetic data are consistent with the hypothesis of reduced affinity with increasing MW for monovalent hapten conjugates, but neither offered overwhelming proof.

Anti-drug antibodies as drug carriers. I. For small molecules

PURPOSE

To better understand the pharmacokinetics of drugs compounds that bind endogenous antibodies

METHODS

Three groups of mice with differing anti-fluorescein (FL) titers were established by empirically developed immunization protocols. These with two control groups were given intravenously [3H]-ethanolamine conjugate of FL (FL-EA). The latter was synthesized using isothiocyanate chemistry. Radioactivity in the circulation, and occasionally in peritoneal ascites, was monitored for 7 days. A group of mice was immunized with eosin Y and given FL-EA. Conversely, eosin Y conjugate of radiolabeled EA (EY-EA) was given to mice immunized with FL. These two groups represented animals of low affinity to probe haptens. The affinity was assessed by a precipitation procedure, while titer was determined by a standard ELISA. Dose of FL-EA varied over a 100-fold.

RESULTS

On average, the three immunized groups showed a 1:13:85 ratio of anti-FL titer, with remarkably consistent levels within each group. Elimination rates of FL-EA from the serum of very high-titer mice and high-titer mice were similar, however, were substantially lower than that found in low-titer mice. The latter was in turn lower than that found in non- or mock-immunized mice. Serum of mice immunized with FL showed approximately 200-fold lower affinity towards EY-EA than FL-EA. In these mice and in mice immunized with eosin Y and given FL-EA, the elimination of the probe haptens was again fast, reminiscent of low-titer mice. Mice of either low titer or low affinity showed more rapid redistribution of the conjugate between serum and peritoneal fluid. In a group of mice with comparable anti-FL titer, elimination from serum was independent of dose over a 100-fold difference. The bi-phasic concentration-time profile observed was accommodated by a physiologically meaningful pharmacokinetic model incorporating two compartments in which antibody binding can occur.

CONCLUSIONS

Monovalent antigenic substance cannot trigger immune clearance. As such, endogenous antibodies that recognize the molecule can serve as a carrier to result in a substantial decrease in clearance.

A strategy for the identification of proteins targeted by thioredoxin

Thioredoxins are 12-kDa proteins functional in the regulation of cellular processes throughout the animal, plant, and microbial kingdoms. Growing evidence with seeds suggests that an h-type of thioredoxin, reduced by NADPH via NADP-thioredoxin reductase, reduces disulfide bonds of target proteins and thereby acts as a wakeup call in germination. A better understanding of the role of thioredoxin in seeds as well as other systems could be achieved if more were known about the target proteins. To this end, we have devised a strategy for the comprehensive identification of proteins targeted by thioredoxin. Tissue extracts incubated with reduced thioredoxin are treated with a fluorescent probe (monobromobimane) to label sulfhydryl groups. The newly labeled proteins are isolated by conventional two-dimensional electrophoresis: (i) nonreducing/reducing or (ii) isoelectric focusing/reducing SDS/PAGE. The isolated proteins are identified by amino acid sequencing. Each electrophoresis system offers an advantage: the first method reveals the specificity of thioredoxin in the reduction of intramolecular vs. intermolecular disulfide bonds, whereas the second method improves the separation of the labeled proteins. By application of both methods to peanut seed extracts, we isolated at least 20 thioredoxin targets and identified 5-three allergens (Ara h2, Ara h3, and Ara h6) and two proteins not known to occur in peanut (desiccation-related and seed maturation protein). These findings open the door to the identification of proteins targeted by thioredoxin in a wide range of systems, thereby enhancing our understanding of its function and extending its technological and medical applications.

CNS cholinergic innervation to the hippocampus in the rat using pseudorabies virus as a neurotracer

The hippocampus is a central area of the memory-related neural system. Combined immunohistochemistry against choline acetyl transferase and retrograde transneuronal labelling of the pseudorabies virus were used to identify cholinergic neurons in the central nervous system projecting to the hippocampal formation of the rat. Five to ten microL of Bartha strain of pseudorabies virus were injected into the dentate gyrus, CA1 and CA3 of the hippocampus of 20 Sprague Dawley rats using stereotaxic instrument. Forty eight to 96 hr after the injection, the brains were removed and the tissue sections were processed for double immunofluorescence procedure using polyclonal antibodies against pseudorabies virus or choline acetyl transferase. The double labelled neurons were distributed at several different nuclei and the labelling patterns of three different areas of the hippocampus were similar. These data suggests that the cholinergic innervation to the hippocampus were distributed in a transsynaptic manner throughout the whole brain area.

Serum amylase and lipase elevation is associated with intracranial events

Serum amylase and lipase elevation has been observed in trauma patients and patients with traumatic intracranial bleeding. However, the causes of this elevation have not been clearly elucidated. A further question remains as to whether other intracranial events are associated with such enzyme elevation as well. We retrospectively reviewed 75 patients consecutively admitted to Cook County Hospital Neurosurgical Intensive Care Unit over a 3-month period for trauma, infection, tumor, or other space-occupying lesions with an unstable condition or neurological deficit. Eleven patients (15%) had elevated amylase and lipase levels. The patients were divided into two groups: Group I (n = 64) had normal and Group II (n = 11) had raised amylase and lipase levels [amylase 402 +/- 444 U/L with normal < or = 125 U/L and lipase 474 +/- 313 U/L with normal < or = 55 U/L]. All Group II patients suffered an intracranial event. Twenty-four Group I (38%) and 10 Group II (91%) patients required craniotomy (P < 0.01). No patients had clinical or radiographic evidence of pancreatitis. In summary, intracranial events are associated with serum amylase and lipase elevation probably through centrally activated pathways. Because of the lack of diagnostic value, routine pancreatic enzyme monitoring should not be performed in this patient population.

A novel cold-inducible zinc finger protein from soybean, SCOF-1, enhances cold tolerance in transgenic plants

Cold stress on plants induces changes in the transcription of cold response genes. A cDNA clone encoding C2H2-type zinc finger protein, SCOF-1, was isolated from soybean. The transcription of SCOF-1 is specifically induced by low temperature and abscisic acid (ABA) but not by dehydration or high salinity. Constitutive overexpression of SCOF-1 induced cold-regulated (COR) gene expression and enhanced cold tolerance of non-acclimated transgenic Arabidopsis and tobacco plants. SCOF-1 localized to the nucleus but did not bind directly to either C-repeat/dehydration (CRT/DRE) or ABA responsive element (ABRE), cis-acting DNA regulatory elements present in COR gene promoters. However, SCOF-1 greatly enhanced the DNA binding activity of SGBF-1, a soybean G-box binding bZIP transcription factor, to ABRE in vitro. SCOF-1 also interacted with SGBF-1 in a yeast two-hybrid system. The SGBF-1 transactivated the beta-glucuronidase reporter gene driven by the ABRE element in Arabidopsis leaf protoplasts. Furthermore, the SCOF-1 enhanced ABRE-dependent gene expression mediated by SGBF-1. These results suggest that SCOF-1 may function as a positive regulator of COR gene expression mediated by ABRE via protein-protein interaction, which in turn enhances cold tolerance of plants.

Rice 1Cys-peroxiredoxin over-expressed in transgenic tobacco does not maintain dormancy but enhances antioxidant activity

Possible functions that have been proposed for the plant 1Cys-peroxiredoxin, include activity as a dormancy regulator and as an antioxidant. The transcript level of rice 1Cys-peroxiredoxin (R1C-Prx) rapidly decreased after imbibition of rice seeds, but the protein was detected for 15 days after imbibition. To investigate the function of this protein, we generated transgenic tobacco plants constitutively expressing the R1C-Prx gene. The transgenic R1C-Prx plants showed a germination frequency similar to control plants. However, the transgenic lines exhibited higher resistance against oxidative stress, suggesting that antioxidant activity may be its primary function.