Vancouver call for action to strengthen expertise in radiological protection worldwide

Ionising radiation has been used for over a century for peaceful purposes, revolutionising health care and promoting well-being through its application in industry, science, and medicine. For almost as long, the International Commission on Radiological Protection (ICRP) has promoted understanding of health and environmental risks of ionising radiation and developed a protection system that enables the safe use of ionising radiation in justified and beneficial practices, providing protection from all sources of radiation. However, we are concerned that a shortage of investment in training, education, research, and infrastructure seen in many sectors and countries may compromise society's ability to properly manage radiation risks, leading to unjustified exposure to or unwarranted fear of radiation, impacting the physical, mental, and social well-being of our peoples. This could unduly limit the potential for research and development in new radiation technologies (healthcare, energy, and the environment) for beneficial purposes. ICRP therefore calls for action to strengthen expertise in radiological protection worldwide through: (1) National governments and funding agencies strengthening resources for radiological protection research allocated by governments and international organisations, (2) National research laboratories and other institutions launching and sustaining long-term research programmes, (3) Universities developing undergraduate and graduate university programmes and making students aware of job opportunities in radiation-related fields, (4) Using plain language when interacting with the public and decision makers about radiological protection, and (5) Fostering general awareness of proper uses of radiation and radiological protection through education and training of information multipliers. The draft call was discussed with international organisations in formal relations with ICRP in October 2022 at the European Radiation Protection Week in Estoril, Portugal, and the final call announced at the 6th International Symposium on the System of Radiological Protection of ICRP in November 2022 in Vancouver, Canada.

Efficacy of interferential current transcutaneous electrical sensory stimulation through the neck skin for treating dysphagia in children with disabilities: A case series

Finding a suitable treatment for dysphagia has been challenging and the efficacy of neuromuscular electrical stimulation has been recognized. Moreover, the beneficial effect of interferential current transcutaneous electrical sensory stimulation has recently been described. However, the efficacy of interferential current transcutaneous electrical sensory stimulation in children with disabilities is unknown. Therefore, the aim of this study was to confirm the efficacy of interferential current transcutaneous electrical sensory stimulation in children with disabilities. Four children with disabilities of various types underwent interferential current transcutaneous electrical sensory stimulation once a week. All patients showed improved symptoms after interferential current transcutaneous electrical sensory stimulation treatment. Videoendoscopic examination showed reduced accumulation of secretion in all patients and decreased residual bolus in two. We also felt an increased forcefulness when swallowing in two. In addition, the questionnaire results regarding dysphagia indicated improvements. No significant side effects were observed. The interferential current transcutaneous electrical sensory stimulation treatment may be effective and safe in children with disabilities. The effect of this treatment on swallowing ability needs to be further investigated by studying more cases.

Survival and renal outcomes of direct heart transplant from veno-arterial extracorporeal membrane oxygenation support

Backgrounds

Patients on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support are given the highest priority for cardiac transplantation (OHT) in the new UNOS heart allocation policy adopted in October 2018. Although patients may receive an organ quicker there may not be enough time to recover end-organ function. To date, little is known about survival and renal outcomes of direct OHT in patients that have been supported with VA-ECMO as a bridge to transplant due to limited experience in most transplant centers.

Purpose

The aim of this study was to investigate survival and renal outcomes of direct OHT in patients supported with VA-ECMO prior to transplant.

Methods

From January 2010 to February 2022, 23 patients who received single organ OHT alone directly from VA-ECMO support were retrospectively analyzed (16 patients after the new allocation policy). Kaplan-Meier analysis was used to estimate event-free survival.

Results

The median age of recipients was 48 years. The median length of pre-transplant VA-ECMO support was 5 days. Additional pre-transplant support with intra-aortic balloon pump or Impella was utilized in 15 patients (65.2%) and 2 patients (9%) respectively. There was a trend toward improvement of serum creatinine after initiation of VA-ECMO support (Pre-ECMO: 1.66±1.22 mg/dl vs. Pre-OHT: 1.20±0.74 mg/dl, P=0.084). Four patients required preoperative renal replacement therapy (RRT); three were on RRT at the time of OHT. The median ischemic time of donor hearts was 168 minutes. VA-ECMO support was continued in 10 patients (43.5%) after OHT.

Hospital mortality was 8.7% (2 patients). Post-transplant RRT was required in 9 patients (39.1%), and, of these, 5 patients were transitioned to permanent dialysis. Among the 14 patients who did not require post-transplant RRT, none required RRT during the follow-up period (median, 21.5 months). Kaplan-Meier survival analysis showed that estimated survival at 1 year and 3 years were 86.1%, and 77.5%, respectively (Figure 1A). The freedom from dialysis rate was 82.4% at 1 year, and 74.9% at 3 years (Figure 2A). Both survival (100% vs. 66.7%, P=0.008, Fig.1B) and dialysis free rate (100% vs. 55.6%, P=0.002, Figure 2B) at one-year were significantly worse in patients who required postoperative RRT.

Conclusions

To our knowledge this is the largest single center study of OHT in patients that were supported with VA-ECMO. VA-ECMO as a bridge to end-organ recovery and OHT resulted in excellent outcomes. Patients who required post-transplant RRT more likely to require long-term dialysis, while those that did not receive RRT showed favorable outcomes. Overall survival in this patient population is comparable to patients that were not on VA-ECMO prior to transplant.

Funding Acknowledgement

Type of funding sources: None.

Summary of the 2021 ICRP workshop on the future of radiological protection

The International Commission on Radiological Protection (ICRP) has embarked on a process to review and revise the current System of Radiological Protection ('the System'). To stimulate discussion, the ICRP published two open-access articles: one on aspects of the System that might require review, and another on research that might improve the scientific foundation of the System. Building on these articles, the ICRP organized a Workshop on the Future of Radiological Protection as an opportunity to engage in the review and revision of the System. This digital workshop took place from 14 October-3 November 2021 and included 20 live-streamed and 43 on-demand presentations. Approximately 1500 individuals from 100 countries participated. Based on the subjects covered by the presentations, this summary is organized into four broad areas: the scientific basis, concepts and application of the System; and the role of the ICRP. Some of the key topics that emerged included the following: classification of radiation-induced effects; adverse outcome pathway methodologies; better understanding of the dose-response relationship; holistic and reasonable approaches to optimization of protection; radiological protection of the environment; ethical basis of the System; clarity, consistency and communication of the System; application of the System in medicine and application of the principles of justification and optimization of protection.

Keeping the ICRP recommendations fit for purpose

The International Commission on Radiological Protection (ICRP) has embarked on a review and revision of the system of Radiological Protection that will update the 2007 general recommendations in ICRPPublication 103. This is the beginning of a process that will take several years, involving open and transparent engagement with organisations and individuals around the world. While the system is robust and has performed well, it must adapt to address changes in science and society to remain fit for purpose. The aim of this paper is to encourage discussions on which areas of the system might gain the greatest benefit from review, and to initiate collaborative efforts. Increased clarity and consistency are high priorities. The better the system is understood, the more effectively it can be applied, resulting in improved protection and increased harmonisation. Many areas are identified for potential review including: classification of effects, with particular focus on tissue reactions; reformulation of detriment, potentially including non-cancer diseases; re-evaluation of the relationship between detriment and effective dose, and the possibility of defining detriments for males and females of different ages; individual variation in the response to radiation exposure; heritable effects; and effects and risks in non-human biota and ecosystems. Some of the basic concepts are also being considered, including the framework for bringing together protection of people and the environment, incremental improvements to the fundamental principles of justification and optimisation, a broader approach to protection of individuals, and clarification of the exposure situations introduced in 2007. In addition, ICRP is considering identifying where explicit incorporation of the ethical basis of the system would be beneficial, how to better reflect the importance of communications and stakeholder involvement, and further advice on education and training. ICRP invites responses on these and other areas relating to the review of the System of Radiological Protection.

ICRP recommendations for recovery

In 2020, the International Commission on Radiological Protection (ICRP) issued Publication 146 which provides a framework of the radiological protection of people and the environment in the case of a large nuclear accident. Mitigation of radiological consequences is achieved using the fundamental principles of justification of decisions and optimisation of protection. These recommendations emphasise the importance of the optimisation of protection for the rehabilitation of living and working conditions in the affected areas during the intermediate and long-term phases. They underline the role of co-operation between the authorities, experts, and the affected population in the co-expertise process to facilitate informed decisions about their own protection. ICRP defines reference levels to be selected within generic bands of exposure considering the induced risk of radiation, as well as the feasibility of controlling the situation.

Computed tomography of the head and the risk of brain tumours during childhood and adolescence: results from a case-control study in Japan

To clarify whether medical radiation exposure, especially from head computed tomography (CT), increases the risk of brain tumours in young patients in Japan, which ranks the second highest in the world in the number of paediatric CT examinations following the US. From 2011 to 2015, we performed a case-control study of 120 brain tumour patients and 360 appendicitis patients as controls. Reasons, the number of brain and head CT scans date were available from interviews. A cumulative radiation dose to the brain was calculated as a sum of doses received from head CT scans and from conventional X-rays and estimated using a reference table derived from a literature review of published studies. We performed conditional logistic regression to assess the risk of brain tumours from brain and head CT, and from conventional head X-ray procedures. The case group received on average 1.8 CTs to the brain area and 2.2 CTs to the whole head, with a mean estimated brain dose of 32 ±13 mGy. The odds ratio for developing a brain tumour from having a brain CT was 0.93 (95% confidence interval: 0.38-1.82). This was hardly altered when adjusting for parental educational history and for other diseases (history of neurological disease and attention-deficit disorder/attention-deficit hyperactivity disorder). Neither whole head CT nor cumulative brain dose to the brain increased the risk of glioma or of all brain tumours. Although this study conducted in Japan, where ranks second in the number of CT scans conducted in the world, did not show an increased risk of brain tumours related to CT scans, it should be taken with caution due to a case-control study with limited sample size.

Abstract P1-06-11: Microsatellite instability in triple negative breast cancers

Background:Microsatellite instability (MSI) is a phenotype resulting from defect in mismatch repair genes. The Food and Drug Administration approved anti-programmed death 1 (PD-1) immune checkpoint inhibitor for any solid tumor with MSI-high (MSI-H). Some tumors had good response to PD-1 blockade and it is a promising treatment for a part of refractory breast cancers. Our goal was to determine the frequency of MSI in triple negative breast cancer (TNBC), one of the most clinically aggressive subtypes.

Patients and Methods:This study included 228 patients with primary TNBC underwent resection without neoadjuvant chemotherapy between January 2004 and December 2014. Genomic DNA was extracted from formalin-fixed and paraffin-embedded tissue. Tumor and control DNA were amplified by polymerase chain reaction at the following 5 microsatellite markers: NR-21, BAT-26, BAT-25, NR-24, MONO-27. We classified the tumors as microsatellite stable(MSS), MSI-low or MSI-H.

Results: The mean age of patients was 59 years (range: 30-89) and all were women. T1 tumors were 57.9% and N0 were 67.5%. Meanwhile, the tumors with nuclear grade 3 were 66.2% and high Ki-67 (> 30%) were 66.7%. Among the 228 tumors, 222 tumors (97.4%) revealed MSS, of which 6 (2.6%) revealed MSI and 2 (0.9%) were MSI-H. Among the MSI tumors, T and N factor were showed as follows: T1: 2 tumors, T2: 3 tumors, T3: 1 tumor, N0: 5 tumors and N1: 1 tumor. Of two MSI-H tumors, one showed T1N0 and another showed T2N0. The both of them showed nuclear grade 3, high Ki-67 (> 30%) and had common following instable markers: NR-21, BAT-26 and BAT-25.

Conclusions: Our results demonstrated that the frequency of MSI-H was 0.9% (2/228). MSI might not be useful as a biomarker for immune check point inhibitors. MSI should be combined with another biomarker such as tumor mutational burden in TNBC.

Citation Format: Kurata K, Kubo M, Mori H, Kawaji H, Motoyama Y, Kuroki L, Yamada M, Kaneshiro K, Kai M, Nakamura M. Microsatellite instability in triple negative breast cancers [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-06-11.

Abstract P4-06-22: Transcription factor T-bet and PD-L1 expression in tumor microenvironment of triple-negative breast cancer

Background: Many analyzes regarding immunotherapies using checkpoint blockade has made it clear that tumor infiltrating lymphocytes (TILs) plays an important role in treating cancers with high levels of somatic mutations such as triple-negative breast cancer (TNBC). We reported the relationship between TILs and PD-L1 expression, and revealed that high-TILs/positive-PD-L1 expression population in TNBC was associated with better prognosis (Oncotarget 2017). However, its molecular mechanism is still unclear. Meanwhile, T-box transcription factor 21 (T-bet) which regulates effecter T-cells activation is derived by stimulation of T-cell receptor and IL-12. Activated T-cells work as antitumor lymphocytes by enhancing the production of cytokines such as INFγ. We focused on T-bet and examined the function of activated T-cells.

Patients and Methods: This study included 242 patients with primary TNBC who underwent resection without neoadjuvant chemotherapy at our three hospitals between January 2004 and December 2014. The immunohistochemistry scoring for CD8 and T-bet expression on TILs was defined as ≥30 per 0.00625mm2. PD-L1 positivity was defined as ≥1% of tumor cells staining positive for PD-L1.

Results: Of the 242 TNBC, CD8 on TILs was expressed as positive in 127 (52.5%) tumors, T-bet on TILs was expressed as positive in 67 (27.7%) tumors, and PD-L1 expression on tumor cells was expressed as positive in 99 (40.9%) tumors. T-bet expression was significantly correlated with CD8 expression (P<0.0001) and PD-L1 expression (P=0.0004). There was no significant difference in recurrence free survival (RFS) and overall survival (OS) regardless of CD8 or PD-L1expression level. Meanwhile, the patients with T-bet-positive tumors had a longer OS, compared to those with T-bet-negative tumors (P = 0.13 in RFS and P = 0.047 in OS). The multivariate analysis revealed that T-bet expression on TILswas an independent and positive prognostic factor for OS(HR = 0.5, 95%CI 0.1-0.9, P = 0.035).

Conclusion: OS was significantly longer among patients with high T-bet expressing TNBC. These results may validate the significance of T-bet as a biomarker for various immunotherapies in TNBC.

Citation Format: Mori H, Kubo M, Kai M, Kurata K, Kawaji H, Kaneshiro K, Motoyama Y, Kuroki R, Yamada M, Nishimura R, Okido M, Oda Y, Nakamura M. Transcription factor T-bet and PD-L1 expression in tumor microenvironment of triple-negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-06-22.

Antimicrobial resistance in leprosy: results of the first prospective open survey conducted by a WHO surveillance network for the period 2009-15

OBJECTIVES

Antimicrobial resistance (AMR) is a priority for surveillance in bacterial infections. For leprosy, AMR has not been assessed because Mycobacterium leprae does not grow in vitro. We aim to obtain AMR data using molecular detection of resistance genes and to conduct a prospective open survey of resistance to antileprosy drugs in countries where leprosy is endemic through a WHO surveillance network.

METHODS

From 2009 to 2015, multi-bacillary leprosy cases at sentinel sites of 19 countries were studied for resistance to rifampicin, dapsone and ofloxacin by PCR sequencing of the drug-resistance-determining regions of the genes rpoB, folP1 and gyrA.

RESULTS

Among 1932 (1143 relapse and 789 new) cases studied, 154 (8.0%) M. leprae strains were found with mutations conferring resistance showing 182 resistance traits (74 for rifampicin, 87 for dapsone and 21 for ofloxacin). Twenty cases showed rifampicin and dapsone resistance, four showed ofloxacin and dapsone resistance, but no cases were resistant to rifampicin and ofloxacin. Rifampicin resistance was observed among relapse (58/1143, 5.1%) and new (16/789, 2.0%) cases in 12 countries. India, Brazil and Colombia reported more than five rifampicin-resistant cases.

CONCLUSIONS

This is the first study reporting global data on AMR in leprosy. Rifampicin resistance emerged, stressing the need for expansion of surveillance. This is also a call for vigilance on the global use of antimicrobial agents, because ofloxacin resistance probably developed in relation to the general intake of antibiotics for other infections as it is not part of the multidrug combination used to treat leprosy.

Progression-dependent transport heterogeneity of breast cancer liver metastases as a factor in therapeutic resistance

Metastatic disease is a major cause of mortality in cancer patients. While many drug delivery strategies for anticancer therapeutics have been developed in preclinical studies of primary tumors, the drug delivery properties of metastatic tumors have not been sufficiently investigated. Therapeutic efficacy hinges on efficient drug permeation into the tumor microenvironment, which is known to be heterogeneous thus potentially making drug permeation heterogeneous, also. In this study, we have identified that 4 T1 liver metastases, treated with pegylated liposomal doxorubicin, have unfavorable and heterogeneous transport of doxorubicin. Our drug extravasation results differ greatly from analogous studies with 4 T1 tumors growing in the primary site. A probabilistic tumor population model was developed to estimate drug permeation efficiency and drug kinetics of liver metastases by integrating the transport and structural properties of tumors and delivered drugs. The results demonstrate significant heterogeneity in metastases with regard to transport properties of doxorubicin within the same animal model, and even within the same organ. These results also suggest that the degree of heterogeneity depends on the stage of tumor progression and that differences in transport properties can define transport-based tumor phenotypes. These findings may have valuable clinical implications by illustrating that therapeutic agents can permeate and eliminate metastases of "less resistant" transport phenotypes, while sparing tumors with more "resistant" transport properties. We anticipate that these results could challenge the current paradigm of drug delivery into metastases, highlight potential caveats for therapies that may alter tumor perfusion, and deepen our understanding of the emergence of drug transport-based therapeutic resistance.

Errata: Internal doses from radionuclides and their health effects following the Fukushima accident (J. Radiol. Prot. 2018 38 1253-68)

This article presents errata on a published article.

Abstract P6-07-05: PD-L1 expression and decreased tumor-infiltrating lymphocytes are associated with poor prognosis in patients with triple negative breast cancer

Background: Tumor microenvironment has been considered to have an active role in determining the aggressiveness of tumor cells. Recently, programmed cell death ligand-1 (PD-L1) expression or tumor-infiltrating lymphocytes (TILs) are known to be an important prognostic factor of breast cancer. However, the correlation of expression of PD-L1 and TILs still remains unclear. Triple-negative breast cancer (TNBC) is a heterogeneous tumor that encompasses many different subclasses. Further identification of these subclasses is necessary in order to predict prognosis and choose appropriate treatments. Our goal was to correlate PD-L1 expression with clinicopathological features including TILs by using a large cohort of TNBCs.

Patients and Methods: This study included 248 patients with primary TNBC who underwent resection without neoadjuvant chemotherapy at our three hospitals between January 2004 and December 2014. The tumor subtypes were routinely determined immunohistochemically by using resected specimens. IHC scoring for PD-L1 expression was defined in reference to that for HER2 expression. PD-L1 positivity was defined as both IHC 2+ and IHC 3+. Cases were defined as high if stromal TILs ≥50% according to recommendations by the International TILs Working Group.

Results: Of the 248 TNBCs, PD-L1 were expressed as positive in 103 (41.5%) tumors, and TILs were highly present in 118 (47.6%) tumors. PD-L1 expression was significantly correlated with higher levels of TILs (P < 0.0001). There was no significant difference when the prognosis of the patients who had PD-L1-positive tumors was compared with that of the patients who had PD-L1-negative tumors (P = 0.56 in recurrence free survival [RFS] and P = 0.13 in overall survival [OS]). Meanwhile, the patients with high-TILs tumors had longer OS, compared to the patients with low-TILs tumors (P = 0.55 in RFS and P = 0.016 in OS). The analysis in the cross effect between PD-L1 expression and TILs using cox proportional hazards model demonstrated that the PD-L1 expression and TILs are not independent factors(P = 0.0018 in RFS and P = 0.015 in OS). The PD-L1-positive group with low-TILs had significantly shorter survival than the PD-L1-positive group with high-TILs (hazard ratio [HR] = 4.7, 95% confidence interval [CI] 1.6–12.7, P = 0.0067 in RFS; HR = 8.4, 95%CI 2.3-30.3, P = 0.0019 in OS).

Conclusions: Our data indicated that PD-L1 expression was related to higher levels of TILs, and PD-L1-positive tumors with low-TILs were associated with poor prognosis in patients with TNBCs. It is proposed that these biomarkers may be of use for predicting their prognosis and essential in the subclassification of TNBCs.

Citation Format: Mori H, Kubo M, Yamaguti R, Nishimura R, Osako T, Arima N, Okumura Y, Okido M, Yamada M, Kai M, Kishimoto J, Oda Y, Nakamura M. PD-L1 expression and decreased tumor-infiltrating lymphocytes are associated with poor prognosis in patients with triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-07-05.

Abstract P5-05-04: MALDI mass spectrometry imaging profile of low molecular metabolites in breast carcinoma tissues embedded in frozen tissue microarray

[Background]

Metabolomics is now widely utilized for searching disease markers or identification of new drug targets. In common method, tissue samples originated in human resected specimens are stored by formalin-fixed, paraffin-embedded (FFPE) blocks. However, these samples are inadequate to measure low molecular metabolites or lipids. Furthermore, extraction process that is required for conventional mass-spectrometry causes the loss of information on the spatial localization of the metabolites. In this study, we directly analyzed breast carcinoma tissues embedded in frozen tissue microarray (fTMA) using MALDI mass spectrometry imaging (MALDI-MSI). With our original method, we could obtain profiles of low molecular metabolite and mapping images of several tissues at one time.

[Method]

Six fTMA blocks were constructed by 119 breast tissues (carcinoma 84, normal 35) from 99 patients and sectioned at 10 um thickness. MADLI-MSI were performed by AXIMA Confidence (Shimadzu, Japan) with 9-aminoacridine as a matrix (m/z range:50∼1000, Negative Ion mode). Carcinoma and normal area in individual tissues were confirmed by H&E staining of slide grasses after MADLI-MSI analysis. Acquired MSI data were processed with the freely available software BioMap (Novartis, Switzerland).

[Result]

We could detected 1,915 peaks derive from endogenous metabolite by direct tissue MALDI-MSI analysis of breast carcinoma fTMA. Among them, 185 peaks that could be commonly detected were subjected to further analysis. Among these peaks, we could identify 18 metabolites related to energy metabolism such as ATP. By comparison of metabolite profiles obtained from carcinoma with normal tissues, we found that the energy charge (EC; which is related to ATP, ADP and AMP concentrations) and the sum of adenosine phosphate compound intensities (AXP) were significantly higher than that of normal tissue (EC; T : N = 0.56 : 0.35, AXP; 17453 : 2066, p<0.0001), but there were no significant difference with lymph node metastasis, tumor histological type and tumor size. In comparison with tumor subtype, higher EC was observed in ER(+)/ Her2(-) tumor than others but AXP showed no significant among all subtypes including Ki-67 labeling index.

[Conclusion]

A combination of fTMA and MALDI-MSI is promising approach for biomarker discovery because it can achieve high throughput metabolic mapping without obvious artifact or other problem. In this study, even though high EC value were indicated in carcinoma tissue than normal but newly biomarker candidate was indeterminate at this moment. Identification of the candidates of novel carcinoma tissue biomarker is now underway.

Citation Format: Torata N, Kubo M, Miura D, Ohuchida K, Miyazaki T, Fujimura Y, Hayakawa E, Kai M, Oda Y, Mizumoto K, Hashizume M, Nakamura M. MALDI mass spectrometry imaging profile of low molecular metabolites in breast carcinoma tissues embedded in frozen tissue microarray. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-05-04.

Abstract P3-06-07: Changes in the tumor microenvironment develop acquired resistance to pegylated liposomal doxorubicin in breast cancer mouse model

Pegylated liposomal doxorubicin (PLD) is one of the most widely used nanotherapeutics for the treatment of advanced/metastatic breast cancer. PLD accumulates in tumors utilizing so-called the enhanced permeation and retention (EPR) effect. Nevertheless, therapeutic efficacy and long term survival remain variable due to the development of acquired resistance. Elucidating the mechanisms of acquired resistance to PLD shall help developing new strategies to improve therapeutic outcome. It has been largely overlooked that the transport of therapeutics across biological barriers can significantly affect the efficacy of cancer therapies. Previously, we showed that the transport of PLD to tumors depends both on the tumor type and organ site. This effect is controlled by the extent to which endothelial cells (ECs) are covered by the collagen type IV (Col4) in the basement membrane, which in turn is influenced by the levels of MMP-9. Here, we have developed 4T1 tumor model which develops acquired resistance to PLD and spontaneous lung metastases. Our objective is to elucidate the resistant mechanism by evaluating the changes in the transport of PLD to the sensitive and resistant/metastatic tumors.

BALB/c mice bearing 4T1 cancers were treated with PLD intravenously when tumor volumes reached a size of approximately 100-200 mm3 . Tumor volumes in all mice decreased after initial PLD injections (sensitive). However, tumors started to grow again after 20 days and didn't respond to the second/third injections (resistant). Furthermore, 13 out of 14 mice developed spontaneous lung metastases. To elucidate the mechanisms of the resistance, mice bearing sensitive or resistant tumors were sacrificed after 24 hours of PLD injection, respectively. PLD accumulation in tumors was evaluated by imaging fluorescence of doxorubicin. Immunofluorescence staining was performed to evaluate the expression of ECs, Col4, MMP-9, and efflux pump associated p-glycoprotein (P-gp) in the primary tumors, and the expression of ECs and Col4 were also evaluated in lung metastases.

PLD accumulation was significantly decreased in the resistant tumors compared to the sensitive tumors, although P-gp expression was not increased in the resistant tumors. The amount of ECs and Col4 increased in the resistant tumors. Interestingly, ECs were covered more tightly by Col4 in the resistant tumors as compared with the sensitive tumors, which could decrease the EPR effect in the tumors. MMP-9 expression decreased in the resistant tumors, suggesting less degradation of Col4 in the basement membrane. Coverage of ECs by Col4 was similar between the metastatic lung tumors and uninvolved lung tissue as well as the resistant primary tumors, indicating the EPR effect is not increased in the metastatic tumors.

In summary, ratio of ECs covered by Col4 is higher in the resistant/metastatic tumors as compared to that in the sensitive primary tumors. This structural change in the tumor microenvironment, impeding the sufficient PLD transport to the tumors after the initial PLD therapy, can be a cause of acquired resistance/development of lung metastasis. These changes should be taken into account to develop strategies for overcoming the acquired resistance and metastasis.

Citation Format: Kai M, Liu YT, Saito Y, Ferrari M, Yokoi K. Changes in the tumor microenvironment develop acquired resistance to pegylated liposomal doxorubicin in breast cancer mouse model. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-06-07.

Abstract P4-09-15: BRCAness and PD-L1 expression of basal-like and not basal-like triple negative breast cancer

Background: Triple Negative Breast Cancer (TNBC) subtype occurs in approximately 20% of all patients with breast cancer and is associated with rapid growth, early metastasis and poor prognosis compared with other subtypes. TNBCs are a heterogeneous disease entity and further subclassification is needed, but still ongoing. In this study, we assessed BRCAness, defined as shared characteristics between sporadic and BRCA1-mutated tumors, in a cohort of basal-like and non-basal-like TNBCs.

Patients and Methods: DNA was isolated from formalin-fixed paraffin-embedded tumor tissues and BRCAness status was analyzed in 262 patients with primary TNBCs resected at our three hospitals between 2004 and 2014. Classification of BRCAness was performed by using Multiple Ligation-dependent Probe Amplification (MLPA) with the probemix P376 BRCA1ness by MRC (Amsterdam, Holland). The tumor subtypes were routinely determined immunohistochemically by using resected specimens. Basal-like phenotype was defined as being positive for Epidermal Growth Factor Receptor (EGFR) and/or Cytokeratin 5/6 (CK5/6). Moreover, TNBCs were stained and analyzed for programmed cell death ligand-1 (PD-L1) expression as a target of new immune therapies.

Results: Of 262 TNBCs, 232 tumors (88.5%) was a basal-like phenotype. The results of MLPA assay showed that 159 (68.5%) of 232 tumors had a BRCAness profile. Patients with basal-like BRCAness tumors were younger than patients with basal-like non-BRCAness tumors (p<0.0001). There was no significant difference between the two groups regarding pathological stage. The basal-like BRCAness group had shorter relapse-free survival (RFS) and overall survival (OS) than the basal-like non-BRCAness group (p=0.028 and p=0.13, respectively), and anthracycline-based regimens provided greater benefit to the basal-like BRCAness group significantly (p=0.01 in RFS and p=0.007 in OS). PD-L1 was expressed in 71 (44.7%) of 159 basal-like TNBCs with BRCAness.

Conclusion: We reported the majority of basal-like TNBCs showed a BRCAness profile and PD-L1 expressed in approximately 50% of BRCAness tumors. It is known that about 30% of BRCAness tumors are BRCA1-mutated tumors. Those biomarkers are essential for subclassification of TNBCs and may offer not only platinum-based chemotherapy but also novel therapies, such as immune-targeted therapies of PD-1/PD-L1 inhibitors and PARP inhibitors, to patients with basal-like TNBCs with BRCAness.

Citation Format: Mori H, Kubo M, Yamada M, Kai M, Osako T, Nishimura R, Arima N, Okido M, Kuroki S, Oda Y, Nakamura M. BRCAness and PD-L1 expression of basal-like and not basal-like triple negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-15.

Abstract P3-03-02: Identification of molecular pathways to define the intake rate of patient-derived hormone receptor positive (HR+) breast cancer xenografts (PDXs) in NOD/SCID/interleukin-2 receptor gamma chain null (NSG) mice

Background and Purpose: Despite recent progress in our endocrine therapy of hormone receptor positive (HR+) breast cancers, a significant number of patients with primary breast cancer continue to relapse, and those with stage IV disease face a median overall survival of ∼ 3.5 years. Primary or acquired resistance to anti-estrogen-based therapies is an overarching challenge. To guide our treatment selection, there is an essential need to improve our understanding of the biology of HR+ breast tumors responsive to and those resist to anti-estrogens or aromatase inhibitors (AIs). The application of patient-derived xenografts (PDXs) in preclinical studies has begun to open the door to mimicking human disease on the research bench. However, HR+ breast cancer PDXs are difficult to establish. Although preclinical data from DeRose et al [Nat. Med. 2011: 17:1514-1520] indicate that the rate of engraftment serves as an independent predictor for poor outcome, the question which has not yet been adequately addressed is: "why some tumors can grow in mice, and some don't, even when their clinical, pathological stage and subtype (i.e. ER positivity) are same?" Here, we hypothesize that the molecular characteristics of patient HR+ tumors are key determinants to the tumor intake rate in NOD/SCID/interleukin-2 receptor gamma chain null (NSG) mice. Hence, reverse phase protein array (RPPA) analysis has be performed using human patient tumors to identify driver-pathways that impact tumor intake in NSG mice.

Results and Discussion: We compared the protein expression profile of six HR+ patient tumors (four HR+ and two HR+ HER2+), which were successfully engrafted into NSG mice and established as PDX models, with the patient tumors which we were unable to establish as PDX. Of 90 patient HR+ tumors which failed to transplant, 21 tumors were picked to match the tumor type (all of them were invasive ductal carcinoma or its metastases), clinical stage and pathological grade of engrafted tumors [Table 1]. In addition to patient tumors, six established HR+ PDXs were also submitted for analysis. Quantified expressions of 272 cancer-related proteins and phospho-proteins by RPPA have been performed on these specimens. Pathways identified as predictors of intake rate of PDXs in NSG mice, and tissues from paired PDX from mice with different passages, will be evaluated for the protein expression changes to elucidate the passage effects and generate therapeutic models based on protein expression and tumor growth.

Table 1. Characteristics of the patient tumors which were successfully established as PDX modelsERPgRHER2AgePatient ethnicityClinical stageNottingham histologic scoreSource++-63Hispanic3IIIBreast tumor+--71Hispanic2IIIBreast tumor+--52African-american4N/ABrain mets+--63Caucasian4N/AChest wall mets+-+34Caucasian2IIBreast tumor+++72Caucasian4IIIChest wall metsmets: metastases

Citation Format: Kanaya N, Somlo G, Wu J, Frankel P, Wu SV, Nguyen D, Kai M, Chan N, Meng-Yin H, Kirschenbaum M, Kruper L, Vito C, Yuan Y, Hurria A, Mortimer J, Chen S. Identification of molecular pathways to define the intake rate of patient-derived hormone receptor positive (HR+) breast cancer xenografts (PDXs) in NOD/SCID/interleukin-2 receptor gamma chain null (NSG) mice. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-03-02.

Clinical utility of neuronal cells directly converted from fibroblasts of patients for neuropsychiatric disorders: studies of lysosomal storage diseases and channelopathy

Methodologies for generating functional neuronal cells directly from human fibroblasts [induced neuronal (iN) cells] have been recently developed, but the research so far has only focused on technical refinements or recapitulation of known pathological phenotypes. A critical question is whether this novel technology will contribute to elucidation of novel disease mechanisms or evaluation of therapeutic strategies. Here we have addressed this question by studying Tay-Sachs disease, a representative lysosomal storage disease, and Dravet syndrome, a form of severe myoclonic epilepsy in infancy, using human iN cells with feature of immature postmitotic glutamatergic neuronal cells. In Tay-Sachs disease, we have successfully characterized canonical neuronal pathology, massive accumulation of GM2 ganglioside, and demonstrated the suitability of this novel cell culture for future drug screening. In Dravet syndrome, we have identified a novel functional phenotype that was not suggested by studies of classical mouse models and human autopsied brains. Taken together, the present study demonstrates that human iN cells are useful for translational neuroscience research to explore novel disease mechanisms and evaluate therapeutic compounds. In the future, research using human iN cells with well-characterized genomic landscape can be integrated into multidisciplinary patient-oriented research on neuropsychiatric disorders to address novel disease mechanisms and evaluate therapeutic strategies.

Calculating disability-adjusted life years (DALY) as a measure of excess cancer risk following radiation exposure

This paper has proposed that disability-adjusted life year (DALY) can be used as a measure of radiation health risk. DALY is calculated as the sum of years of life lost (YLL) and years lived with disability (YLD). This multidimensional concept can be expressed as a risk index without a probability measure to avoid the misuse of the current radiation detriment at low doses. In this study, we calculated YLL and YLD using Japanese population data by gender. DALY for all cancers in Japan per 1 Gy per person was 0.84 year in men and 1.34 year in women. The DALY for all cancers in the Japanese baseline was 4.8 in men and 3.5 in women. When we calculated the ICRP detriment from the same data, DALYs for the cancer sites were similar to the radiation detriment in the cancer sites, excluding leukemia, breast and thyroid cancer. These results suggested that the ICRP detriment overestimate the weighting fraction of leukemia risk and underestimate the weighting fraction of breast and thyroid cancer. A big advantage over the ICRP detriment is that DALY can calculate the risk components for non-fatal diseases without the data of lethality. This study showed that DALY is a practical tool that can compare many types of diseases encountered in public health.

Experience and current issues with recovery management from the Fukushima accident

This paper describes the experiences of, and issues with, recovery management following the accident at Fukushima Daiichi nuclear power plant. The Fukushima accident has brought about socio-economic consequences with inevitable changes to daily life, as well as psychological effects. There is heightened concern amongst the population about the risk and effects of radiation at low doses. Experience has shown that the direct involvement of the affected population and local professionals is a decisive factor for management of the recovery phase. The radiological protection system of the International Commission on Radiological Protection (ICRP) seems to be relevant to the recovery requirements of the Fukushima accident, although some problems remain in implementation. Reference levels could play a role in improving the situation by requiring an iterative optimisation process. The Fukushima experience indicated that a routine, top-down approach using radiological criteria alone was unable to deal with the complexity of the problems, and that stakeholder engagement should be explored. The technical knowledge gap between radiation experts and the public caused a lot of confusion. Experts should understand the ethical values attached to recovery, and ICRP should be more active in promoting trustworthy radiological protection advice.

Genome-wide re-sequencing of multidrug-resistant Mycobacterium leprae Airaku-3

Genotyping and molecular characterization of drug resistance mechanisms in Mycobacterium leprae enables disease transmission and drug resistance trends to be monitored. In the present study, we performed genome-wide analysis of Airaku-3, a multidrug-resistant strain with an unknown mechanism of resistance to rifampicin. We identified 12 unique non-synonymous single-nucleotide polymorphisms (SNPs) including two in the transporter-encoding ctpC and ctpI genes. In addition, two SNPs were found that improve the resolution of SNP-based genotyping, particularly for Venezuelan and South East Asian strains of M. leprae.

Abstract P6-04-06: Targeting cancer stem cells in triple negative breast cancer by a combination treatment of LBH589 and salinomycin

Background and purpose:

Triple-negative breast cancer (TNBC) is aggressive with poorer prognosis compared to breast cancer that is positive for hormone receptors or HER2. This can be explained further due in part to the existence of breast cancer stem cells (BCSCs). Our lab has found that histone deacetylase (HDAC) inhibitors are effective in the growth suppression of TNBC in vitro and in vivo. To understand the mechanisms involved, we performed RNA-seq analysis for TNBC cells treated with two HDAC inhibitors (LBH589 and Entinostat). Our RNA-seq analysis and studies from other laboratories have found that HDAC inhibitors may modify multiple signaling pathways with undesired effects due to its broad reactivity. To improve the efficacy of HDAC inhibitors in the treatment of TNBCs, we have examined the effects of LBH589 in combination with several drugs. Among them, Salinomycin works effectively with LBH589. It has been used as an antibiotic for farm animals, but has been identified from a screen of a large library of chemicals to target BCSCs (Gupta et al., Cell, 2009). The purpose of this study is to examine the synergistic effect between LBH589 and Salinomycin in the anticipation of their clinical utility and to evaluate a new target therapy to treat TNBC more efficiently and completely.

Material and method:

Two TNBC cell lines (HCC1937, MDA-MB-231) were used as models to examine the combined effects of Salinomycin and LBH589. Cell proliferation studies were performed through 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. To evaluate the effects on BCSC population, mammosphere assay was used for estimating self-renewal capacity and ALDEFLUOR analysis was used for monitoring the distribution of BCSCs in treated samples. For tumor induction experiments, ALDH+ cells were injected into NSG mice. As a therapeutic study, single or combined use of LBH589 (10mg/kg) and Salinomycin (5mg/kg) were peritoneally injected into non-obese diabetic scid gamma (NSG) mice 3 days a week. Tumor volume, body weight and food intake were checked weekly. For mechanistic analysis, qPCR, Western blotting and IHC were performed for gene and protein expression using tumors from mice from different treatments.

Results:

Salinomycin and LBH589 worked synergistically in the suppression of the proliferation of TNBCs (IC50 was 68.8nM and 13.1nM, respectively). Similarly, both drugs inhibited mammosphere formation and ALDH positive population in a synergistic manner. The combination of LBH589 (16nM) with Salinomycin (60nM) reduced 60% of mammosphere formation and 94% of ALDH positive population compared with DMSO treatment. In a mouse model, the combination of LBH589 and Salinomycin had an inhibitory effect on tumor growth compared with the control group and the groups treated with single drug. In all groups, no side effect was seen. The results from mechanistic studies showed that the combination of LBH589 and Salinomycin regulated the Wnt/b-catenin pathway.

Discussion:

We have evidence that the combination of LBH589 and Salinomycin has a synergistic effect on TNBC through Wnt pathway and suggested this combination could potentially be a new therapeutic strategy for exploring targeting therapy in TNBC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-04-06.

Olanzapine increases hepatic glucose production through the activation of hypothalamic adenosine 5'-monophosphate-activated protein kinase

AIMS

To investigate the mechanism of the metabolic disturbance induced by the atypical antipsychotic olanzapine, we examined whether adenosine 5'-monophosphate-activated protein kinase (AMPK) in the hypothalamus and hepatic glucose production are involved in the effect of olanzapine.

METHODS

Male 6-week-old ICR mice were used. Blood glucose levels were determined by the glucose oxidase method. The mRNA levels of gluconeogenic or glycolytic enzymes were measured by reverse transcription polymerase chain reaction (RT-PCR). AMPK expression was measured by Western blotting.

RESULTS

Systemic injection of olanzapine increased blood glucose levels in both unfasted and fasted mice. However, the increase in fasted mice was less than that in unfasted mice. Central administration of olanzapine also increased the blood glucose levels in unfasted mice, but not in fasted mice. In a pyruvate tolerance test, olanzapine significantly increased blood glucose levels. In addition, olanzapine increased the mRNA levels of glucose-6-phosphatase (G6Pase), a gluconeogenic enzyme, in the liver. Furthermore, olanzapine increased phosphorylated AMPK in the hypothalamus of unfasted mice, and olanzapine-induced hyperglycaemia was inhibited by the AMPK inhibitor compound C. Central administration of the AMPK activator AICAR significantly increased G6Pase mRNA levels in the liver and blood glucose levels. Moreover, both olanzapine- and AICAR-induced hyperglycaemia were attenuated by the β-adrenergic receptor antagonist propranolol, suggesting that olanzapine and AICAR induce hepatic glucose production through the sympathetic nervous system.

CONCLUSIONS

Our results indicate that olanzapine activates AMPK in the hypothalamus, which increases hepatic glucose production via the sympathetic nervous system.

Activation of spinal cannabinoid CB2 receptors inhibits neuropathic pain in streptozotocin-induced diabetic mice

The role of spinal cannabinoid systems in neuropathic pain of streptozotocin (STZ)-induced diabetic mice was studied. In normal mice, injection of the cannabinoid receptor agonist WIN-55,212-2 (1 and 3μg, i.t.) dose-dependently prolonged the tail-flick latency, whereas there were no changes with the injection of either cannabinoid CB1 (AM 251, 1 μg, i.t.) or CB2 (AM 630, 4 μg, i.t.) receptor antagonists. AM 251 (1 μg, i.t.), but not AM 630 (4 μg, i.t.), significantly inhibited the prolongation of the tail-flick latency induced by WIN-55,212-2 (3 μg, i.t.). In STZ-induced diabetic mice, the tail-flick latency was significantly shorter than that in normal mice. A low dose of WIN-55,212-2 (1 μg, i.t.) significantly recovered the tail-flick latency in STZ-induced diabetic mice. The effect of WIN-55,212-2 (1 μg, i.t.) in STZ-induced diabetic mice was significantly inhibited by AM 630 (4 μg, i.t.), but not AM 251 (1 μg). The selective cannabinoid CB2 receptor agonist L-759,656 (19 and 38 μg, i.t.) also dose-dependently recovered the tail-flick latency in STZ-induced diabetic mice, and this recovery was inhibited by AM 630 (4 μg, i.t.). The protein levels of cannabinoid CB1 receptors, CB2 receptors and diacylglycerol lipase α (DGL-α), the enzyme that synthesizes endocannabinoid 2-arachidonoylglycerol, in the spinal cord were examined using Western blotting. The protein levels of both cannabinoid CB1 and CB2 receptors were increased in STZ-induced diabetic mice, whereas the protein level of DGL-α was significantly decreased. These results indicate that spinal cannabinoid systems are changed in diabetic mice and suggest that cannabinoid CB2 receptor agonists might have an ability to recover diabetic neuropathic pain.