Anti-cancer effect of afatinib, dual inhibitor of HER2 and EGFR, on novel mutation HER2 E401G in models of patient-derived cancer.

BACKGROUND: Precision medicine with gene panel testing based on next-generation sequencing for patients with cancer is being used increasingly in clinical practice. HER2, which encodes the human epidermal growth factor receptor 2 (HER2), is a potentially important driver gene. However, therapeutic strategies aimed at mutations in the HER2 extracellular domain have not been clarified. We therefore investigated the effect of EGFR co-targeted therapy with HER2 on patient-derived cancer models with the HER2 extracellular domain mutation E401G, based on our previous findings that this mutation has an epidermal growth factor receptor (EGFR)-mediated activation mechanism. METHODS: We generated a xenograft (PDX) and a cancer tissue-originated spheroid (CTOS) from a patient's cancer containing an amplified HER2 E401G mutation. With these platforms, we compared the efficacy of afatinib, a tyrosine kinase inhibitor having anti-HER2 and anti-EGFR activity, with two other therapeutic options: lapatinib, which has similar properties but weaker EGFR inhibition, and trastuzumab plus pertuzumab, for which evidence exists of treatment efficacy against cancers with wild-type HER2 amplification. Similar experiments were also performed with H2170, a cell line with wild-type HER2 amplification, to contrast the characteristics of these drug's efficacies against HER2 E401G. RESULTS: We confirmed that PDX and CTOS retained morphological and immunohistochemical characteristics and HER2 gene profiles of the original tumor. In both PDX and CTOS, afatinib reduced tumor size more than lapatinib or trastuzumab plus pertuzumab. In addition, afatinib treatment resulted in a statistically significant reduction in HER2 copy number at the end of treatment. On the other hand, in H2170 xenografts with wild-type HER2 amplification, trastuzumab plus pertuzumab was most effective. CONCLUSIONS: Afatinib, a dual inhibitor of HER2 and EGFR, showed a promising effect on cancers with amplified HER2 E401G, which have an EGFR-mediated activation mechanism. Analysis of the activation mechanisms of mutations and development of therapeutic strategies based on those mechanisms are critical in precision medicine for cancer patients.

Management system of home transfusion in Japan: A nationwide survey in 2019.

BACKGROUND AND OBJECTIVES: In Japan, there are various opinions on the pros and cons of home transfusion because of safety concerns. We hence aimed to elucidate the safety and availability of home transfusion in Japan, which has not been clarified to date. MATERIALS AND METHODS: Clinics throughout Japan that provide home care and have experience in performing blood transfusions were surveyed. The analysis period was February to December 2019. Basic information about the clinics, their collaboration system with core hospitals, storage method of red blood cells (RBCs) and the system for the management of patient information regarding transfusion reactions were investigated. RESULTS: Detailed information was obtained regarding the implementation of home transfusions by 51 clinics. The proportion of home care clinics performing home transfusions was 17.6%, and they were more frequently performed in urban regions. Approximately half of the clinics collaborated with a core hospital for emergency responses to transfusion reactions. At 84% of the clinics, RBC units were stored in refrigerators that were not exclusively allocated to blood storage. Nurses and family members were involved as patient attendants in 83% and 77% of the home transfusions, respectively. No serious transfusion reactions were reported among the 150 patients in 2019, nor the 623 patients up to 2018. CONCLUSION: From data on its availability and safety, home transfusions are considered to be in the developing phase in Japan. Increased cooperation between hospitals and clinics is crucial towards improving the home transfusion system in Japan in the future.

Home transfusions are implemented using diverse approaches in Japan.

BACKGROUND AND OBJECTIVES: Japan's ageing society has increased the need for home healthcare, including home transfusions. We hence aimed to elucidate the purpose and utilization of home transfusions in Japan, which has not been clarified to date. MATERIALS AND METHODS: Clinics throughout Japan that provide home care and have experience in performing blood transfusions were surveyed. The study period was February to December 2019, and information of patients receiving home red blood cell transfusions, including patient background, pre-transfusion laboratory data and the purpose of the transfusions, was collected. RESULTS: Haematological malignancies and solid tumours accounted for 70% of the patients' underlying diseases, with the former being significantly more common in urban areas. Regarding the purpose of the home transfusions, haematologists focused on symptom improvement, whereas gastroenterology surgeons focused on life support. Furthermore, maintenance of life was more likely to be the aim in the group of patients with the lowest level of activities of daily living. The main items that were significantly associated with a low haemoglobin level before transfusion included age ≥90 years and a gastroenterologist being the physician in charge. CONCLUSION: Home transfusions were found to be performed in a restrictive and diverse manner in Japan. Life support is the second most common purpose of home transfusion in Japan, and optimizing effective home transfusion remains a challenge.

Targeting aberrant DNA hypermethylation as a driver of ATL leukemogenesis by using the new oral demethylating agent OR-2100.

Adult T-cell leukemia-lymphoma (ATL) is an aggressive hematological malignancy of CD4+ T cells transformed by human T-cell lymphotropic virus-1 (HTLV-1). Most HTLV-1-infected individuals are asymptomatic, and only 3% to 5% of carriers develop ATL. Here, we describe the contribution of aberrant DNA methylation to ATL leukemogenesis. HTLV-1-infected T-cells and their uninfected counterparts were separately isolated based on CADM1 and CD7 expression status, and differentially methylated positions (DMPs) specific to HTLV-infected T cells were identified through genome-wide DNA methylation profiling. Accumulation of DNA methylation at hypermethylated DMPs correlated strongly with ATL development and progression. In addition, we identified 22 genes downregulated because of promoter hypermethylation in HTLV-1-infected T cells, including THEMIS, LAIR1, and RNF130, which negatively regulate T-cell receptor (TCR) signaling. Phosphorylation of ZAP-70, a transducer of TCR signaling, was dysregulated in HTLV-1-infected cell lines but was normalized by reexpression of THEMIS. Therefore, we hypothesized that DNA hypermethylation contributes to growth advantages in HTLV-1-infected cells during ATL leukemogenesis. To test this idea, we investigated the anti-ATL activities of OR-1200 and OR-2100 (OR21), novel decitabine (DAC) prodrugs with enhanced oral bioavailability. Both DAC and OR21 inhibited cell growth, accompanied by global DNA hypomethylation, in xenograft tumors established by implantation of HTLV-1-infected cells. OR21 was less hematotoxic than DAC, whereas tumor growth inhibition was almost identical between the 2 compounds, making it suitable for long-term treatment of ATL patient-derived xenograft mice. Our results demonstrate that regional DNA hypermethylation is functionally important for ATL leukemogenesis and an effective therapeutic target.

Clinical significance of soluble CADM1 as a novel marker for adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/leukemia (ATLL) is an aggressive peripheral T-cell malignancy, caused by infection with the human T-cell leukemia virus type 1 (HTLV-1). We have recently shown that cell adhesion molecule 1 (CADM1), a member of the immunoglobulin superfamily, is specifically and consistently overexpressed in ATLL cells, and functions as a novel cell surface marker. In this study, we first show that a soluble form of CADM1 (sCADM1) is secreted from ATLL cells by mainly alternative splicing. After developing the Alpha linked immunosorbent assay (AlphaLISA) for sCADM1, we showed that plasma sCADM1 concentrations gradually increased during disease progression from indolent to aggressive ATLL. Although other known biomarkers of tumor burden such as soluble interleukin-2 receptor α (sIL-2Rα) also increased with sCADM1 during ATLL progression, multivariate statistical analysis of biomarkers revealed that only plasma sCADM1 was selected as a specific biomarker for aggressive ATLL, suggesting that plasma sCADM1 may be a potential risk factor for aggressive ATLL. In addition, plasma sCADM1 is a useful marker for monitoring response to chemotherapy as well as for predicting relapse of ATLL. Furthermore, the change in sCADM1 concentration between indolent and aggressive type ATLL was more prominent than the change in the percentage of CD4+CADM1+ ATLL cells. As plasma sCADM1 values fell within normal ranges in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients with higher levels of serum sIL-2Rα, a measurement of sCADM1 may become a useful tool to discriminate between ATLL and other inflammatory diseases, including HAM/TSP.

Rapid detection method of carbapenemase-producing Enterobacteriaceae by MALDI-TOF MS with imipenem/cilastatin (KB) disc and zinc sulfate solution.

INTRODUCTION: Carbapenemase-producing Enterobacteriaceae (CPE) is a major global health threat, and development of rapid detection methods is desired. Here, we established a cost-effective and relatively rapid CPE detection method using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). METHODS: We examined 134 CPE strains (IMP-type, NDM-type, VIM-type, KPC-type, OXA-48-like-type, and GES-type) and 107 non-CPE strains, previously confirmed by genetic tests. The proposed MALDI-TOF MS method involves mixing of a carbapenem drug [here, the commercially available imipenem (IPM) KB disc] and the bacterial strains to be tested, and the consequent drug hydrolysis owing to bacterial carbapenemase activity is confirmed by a waveform spectrum before and after 2 h of the mixing. As metallo-beta-lactamases require zinc in their active site, the false-negatives obtained from our method were cultured in presence of zinc sulfate solution and tested again. RESULTS: Based on the presence or absence of the IPM (+cyano-4-hydroxy-cinnamic acid)-specific waveform peak near 489.45 m/z (±500 ppm), the detection sensitivity and specificity of our method for CPE were determined to be 94.8% and 91.6%, respectively. Seven false-negatives of IMP-type (4), VIM-type (2), and GES-type (1) were found, of which the IMP- and VIM-types tested positive as CPE after culture with zinc sulfate solution. Thus, the overall detection sensitivity improved to 99.3%. CONCLUSION: Our study proposes a new approach for CPE detection using MALDI-TOF MS. Moreover, we propose cultivation of test strains with zinc sulfate solution for efficient detection of IMP-type CPE, not only for MALDI-TOF MS, but also for other detection methods.

Correlation of Strain Classification with IR Biotyper and Molecular Epidemiological Method of Pseudomonas aeruginosa.

INTRODUCTION: From 2018, IR Biotyper (IRBT; Bruker Daltonik GmbH, Germany) based on the Fourier transform infrared spectrophotometer has begun to be introduced as a new strain classification method in the field of clinical microbiological examination. We compared it with molecular epidemiology method to evaluate the usefulness of strain classification by IRBT. METHOD: Homology of strain classification with molecular epidemiology method (Multilocus Sequencing Typing; MLST and PCR-based ORF Typing; POT) for 48 strains of Pseudomonas aeruginosa with different detection times from multiple institutions to evaluate the accuracy of IRBT was compared. RESULTS: IRBT used "KBM" SCD agar medium for preculture and was classified into 12 types when classified by Cut-off value 0.181, 8 types by MLST, and 13 types by POT. In the Adjusted Wallace between IRBT and molecular epidemiology method, MLST was 0.458 (95% CI; 0.295 to 0.620) and POT was 0.330 (95% CI; 0.135 to 0.525), indicating a discrepancy in strain classification. CONCLUSION: No correlation was found between IRBT and the classification results by the molecular epidemiology method. In the molecular epidemiology method, strains are classified by matching only specific gene regions, but IRBT irradiates a sample with an infrared laser and classifies the strains according to the difference in absorption spectrum according to the molecular structure, so the measurement principle is different. When classifying strains by IRBT, it is desirable to grasp the clinical information of the detected strains and to target multiple strains isolated at the same facility at the same time.

Clinical impact of the CONUT score in patients with multiple myeloma.

Novel anti-myeloma drugs have significantly improved the overall survival (OS) of patients with multiple myeloma (MM). However, not all MM patients treated with these drugs show survival benefits, and biologic and genetic prognostic factors are insufficient to predict the response to treatment. Decreasing treatment-related complications is important to improve the efficacy of treatment in patients with MM. The Controlling Nutritional Status (CONUT) score is a screening method for poor nutritional status, which is associated with poor prognosis in several cancers because it increases the rate of treatment-related complications. We retrospectively analyzed the OS of 64 patients with symptomatic MM and evaluated the correlation between the CONUT score and patient prognosis in MM. The median age at diagnosis was 66 years, and multivariate analysis showed that a high CONUT score (≥ 5; hazard ratio, 3.937; 95% confidence interval, 1.214-12.658; P = 0.022) was an independent prognostic risk factor. Subgroup analysis was performed according to patient age because the choice of treatment strategy, particularly autologous peripheral blood stem cell transplantation (auto-PBSCT), can vary depending on age in MM patients. Younger patients (< 65 years old) who received auto-PBSCT and had a lower CONUT score (0-3) showed a significantly better survival outcome than those with a higher CONUT score (≥ 4) (median OS, not reached vs. 64.1 months; P = 0.011). The CONUT score is simple to calculate and provides a useful prognostic indicator in patients with MM, especially transplant-eligible patients.

Diagnostic accuracy of FibroScan-AST score to identify non-alcoholic steatohepatitis with significant activity and fibrosis in Japanese patients with non-alcoholic fatty liver disease: Comparison between M and XL probes.

AIM: Recently, FibroScan-AST (FAST) score was reported to be effective for identifying non-alcoholic steatohepatitis (NASH) with significant activity and fibrosis in non-alcoholic fatty liver disease (NAFLD). The aim of this study was to confirm the diagnostic accuracy of FAST score of Japanese patients and compare the cut-off values and diagnostic accuracy between the FibroScan M and XL probes. METHODS: Eighty-two and 84 patients were included the verification and validation sets, respectively. All patients were diagnosed with NAFLD by biopsy by two central expert pathologists. Liver stiffness measurements and controlled attenuation parameter were carried out, and diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS: No significant difference existed in FAST score between the M and XL probes (0.489 vs. 0.483, P = 0.187). No significant difference existed in the area under the ROC between the two probes (M, 0.7598; XL, 0.7614; P = 0.958). According to the Youden index, the cut-off value using the M probe was 0.57 with 68.2% sensitivity and 78.3% specificity. For the XL probe, the cut-off value was 0.56 with 68.2% sensitivity and 73.3% specificity. To obtain sensitivity and specificity values higher than 90%, cut-off values of 0.35 and 0.66 were chosen for the M probe and 0.32 and 0.63 were chosen for the XL probe. CONCLUSIONS: There was no significant difference in diagnostic accuracy of FAST score between the FibroScan M and XL probes. The FAST score can be used to identify NASH with significant risk in Japanese patients regardless of probe selection.

Prognostic index for chronic- and smoldering-type adult T-cell leukemia-lymphoma.

Adult T-cell leukemia-lymphoma (ATL) has been divided into 4 clinical subtypes: acute, lymphoma, chronic, and smoldering. The aim of this study is to develop a novel prognostic index (PI) for chronic and smoldering ATL. We conducted a nationwide retrospective survey on ATL patients, and 248 fully eligible individuals were used in this analysis. In the univariate analysis, sex, performance status, log10 (soluble interleukin-2 receptor [sIL-2R]), neutrophils count, and lymphadenopathy showed values of P < .05 in training samples. A multivariate analysis was performed on these factors, and only log10 (sIL-2R) was identified as an independent prognostic factor in training samples. Using a regression coefficient of this variable, a prognostic model was formulated to identify different levels of risk: indolent ATL-PI (iATL-PI) = 1.51 × log10 (sIL-2R [U/mL]). The values calculated by iATL-PI were divided into 3 groups using a quartile point. In the validation sample, median survival times (MSTs) were 1.6 years, 5.5 years, and not reached for patients in the high-, intermediate-, and low-risk groups, respectively (P < .0001). To make the scoring system clinically practicable, we simplified iATL-PI according to trichotomizing sIL-2R at 1000 and 6000 U/mL, using a quartile point. Patients with more than 6000 U/mL sIL-2R were categorized into the high-risk group, less than and equal to 1000 U/mL into the low-risk group, and the others into the intermediate-risk group, and MSTs were 1.6 years, not reached, and 5.5 years, respectively (P < .0001). iATL-PI has potential as a novel tool for a risk-adapted therapeutic approach.

Clinical impact of the CONUT score and mogamulizumab in adult T cell leukemia/lymphoma.

Accurate risk assessment to determine the eligibility for allogeneic hematopoietic stem cell transplantation (allo-HCT) in patients with adult T cell leukemia (ATL) is necessary to improve survival outcomes. The controlling nutritional status (CONUT) score predicts prognosis in several tumors; however, the prognostic significance of the CONUT score in ATL remains unclear. The present study investigated the correlation between the CONUT score and the survival outcomes of transplant-eligible ATL patients. Mogamulizumab, a humanized monoclonal antibody against C-C chemokine receptor 4, was recently identified as a promising salvage chemotherapy agent for transplant-ineligible ATL patients. We therefore evaluated the efficacy of mogamulizumab in transplant-ineligible ATL patients. Patients diagnosed with aggressive ATL (acute lymphoma of unfavorable chronic type) between January 2008 and March 2017 at Saga University Hospital, Japan, were retrospectively enrolled. Of 54 patients, 25 were < 70 years of age and 14 received allo-HCT. The median overall survival (OS) and non-relapse mortality (NRM) rate at 1 year among patients receiving allo-HCT were 1685.5 days and 30% in those with a CONUT score 0-3 (n = 10) and 184.5 days and 100% in those with a score ≥ 4 (n = 4) (p = 0.017, OS; p = 0.064, NRM). Older patients who received mogamulizumab had a significantly longer OS (n = 12, median 432 days) than those who did not receive mogamulizumab (n = 17, median 199 days) (p = 0.018). The CONUT score was identified as a prognostic tool for transplant-eligible ATL patients, and mogamulizumab improved OS in transplant-ineligible ATL patients.

Incidence of aspiration pneumonia during hospitalization in Japanese hospitalized cases did not increase whereas concern factors were exacerbated in a time-dependent manner: analysis of Diagnosis Procedure Combination (DPC) data.

This study aimed i) to investigate about items with high relevance for aspiration pneumonia during hospitalization among cases evaluated using Diagnosis Procedure Combination data, and ii) to determine whether the concern factors for aspiration pneumonia during hospitalization were exacerbated with the trend of the time. The Diagnosis Procedure Combination data were gathered from 2010 through to 2015 with 63,390 cases at Saga University Hospital. The occurrence of concern factors of aspiration pneumonia during hospitalization were compared in the two time periods set (2010-2012 and 2013-2015). The concern factors included: male, age, dysphagia at admission and during hospitalization, use and days in the emergency care unit or high care unit, use of the intensive care unit, and use of an ambulance. Age, dysphagia, and use of the intensive care unit were time-dependently exacerbated. The incidence of aspiration pneumonia during hospitalization in hospitalized cases did not differ between years 2010-2012 and 2013-2015. Aspiration pneumonia during hospitalization complicated with surgery and number days in the emergency care unit or high care unit diminished in years 2013-2015. Despite an increased concern of aspiration pneumonia during hospitalization, the complication rate of aspiration pneumonia during hospitalization did not increase.

Treatment and survival among 1594 patients with ATL.

Adult T-cell leukemia/lymphoma (ATL) is a malignancy of mature T lymphocytes caused by human T-lymphotropic virus type I. Intensive combination chemotherapy and allogeneic hematopoietic stem cell transplantation have been introduced since the previous Japanese nationwide survey was performed in the late 1980s. In this study, we delineated the current features and management of ATL in Japan. The clinical data were collected retrospectively from the medical records of patients diagnosed with ATL between 2000 and 2009, and a total of 1665 patients' records were submitted to the central office from 84 institutions in Japan. Seventy-one patients were excluded; 895, 355, 187, and 157 patients with acute, lymphoma, chronic, and smoldering types, respectively, remained. The median survival times were 8.3, 10.6, 31.5, and 55.0 months, and 4-year overall survival (OS) rates were 11%, 16%, 36%, and 52%, respectively, for acute, lymphoma, chronic, and smoldering types. The number of patients with allogeneic hematopoietic stem cell transplantation was 227, and their median survival time and OS at 4 years after allogeneic hematopoietic stem cell transplantation was 5.9 months and 26%, respectively. This study revealed that the prognoses of the patients with acute and lymphoma types were still unsatisfactory, despite the recent progress in treatment modalities, but an improvement of 4-year OS was observed in comparison with the previous survey. Of note, one-quarter of patients who could undergo transplantation experienced long survival. It is also noted that the prognosis of the smoldering type was worse than expected.

[Japanese Biobanks: Current Status, Problems, and Future Challenges].

A biobank is a facility that collects and manages biological specimens such as tissues, cells, and blood de- rived from living organisms. In addition to these materials, the biobank can also be used for storing urine, body fluid, DNA, and intracellular structures like exosomes. The initial objective of stocking these materials was mainly for research purposes, such as searching for biomarkers and genes responsible for diseases, but due to the rapid clinical application of molecular-targeted therapy and personalized medicine based on genetic information, biobanking is now becoming one of the fundamental efforts indispensable for clinical practice. In Japan, the importance of stocks of biological samples has been recognized for a long time, and biobanking was implemented in various medical institutions alone or in several medical departments, but recently the organization of biobanks has been developed and they are carrying out activities according to each purpose. 1. Biobank as a national project Biobank, Japan 2. National Center Biobank Network NCBN 3. Biobanks operated by each institution other than those mentioned above As a part of Japan's research strategy, the Japan Agency for Medical Research and Development (AMED) has promoted the "Genomic medicine realization project", and the construction of medical biobanks is one of the major projects in the strategy. In this special issue, the current status of biobanks is introduced and problems and future challenges as a national project are discussed.

[Clinical Hematology for Specialists of Clinical Laboratory Medicine].

The knowledge and skills of clinical hematology necessary for clinical laboratory medicine are different from the knowledge required for the hematological specialists or general physicians. A wide range of knowledge and comprehensive skills to connect the sub-specialty and hematological specialist are required. To do so, comprehensive understanding such as, (1) how to assess the results of blood testing in a relative- ly frequent disease, (2) understanding of specific diseases that require rapid clinical judgment and consulta- tion, (3) the latest diagnostic techniques, including genetic diagnosis, (4) the knowledge of companion diag- nostic techniques necessary for molecular targeted therapy and molecular immunotherapy, are required. However, it is not easy to understand the rapid progress in diagnostic techniques and treatment strategies even in hematological specialists. Therefore, the following points are presented in the seminar; understand- ing of boundary for normal and abnormal findings, evaluation criteria for rapid assessment and report, the feature of hematological malignancies tight cooperation is needed with hematological specialist. In this paper, the role of the specialists on clinical laboratory medicine as a "mediator" in the clinical hema- tology is summarized, especially in anemia and coagulation disorders. [Review].

[Results of Training for Personnel Involved in Blood-Transfusion Testing Outside of Regular Work Hours at Saga University Hospital].

Laboratory testing prior to blood transfusion outside of regular hours in many hospitals and clinics is frequently conducted by technicians without sufficient experience in such testing work. To obtain consistent test results regardless of the degree of laboratory experience with blood transfusion testing, the number of facilities introducing automated equipment for testing prior to blood transfusion is increasing. Our hospital's blood transfusion department introduced fully automated test equipment in October of 2010 for use when blood transfusions are conducted outside of regular hours. However, excessive dependence on automated testing can lead to an inability to do manual blood typing or cross-match testing when necessitated by breakdowns in the automated test equipment, in the case of abnormal specimen reactions, or other such case. In addition, even outside of normal working hours there are more than a few instances in which transfusion must take place based on urgent communications from clinical staff, with the need for prompt and flexible timing of blood transfusion test and delivery of blood products. To address this situation, in 2010 we began training after-hours laboratory personnel in blood transfusion testing to provide practice using test tubes manually and to achieve greater understanding of blood transfusion test work (especially in cases of critical blood loss). Results of the training and difficulties in its implementation for such after-hours laboratory personnel at our hospital are presented and discussed in this paper. [Original]

Reprogramming of pyrimidine nucleotide metabolism supports vigorous cell proliferation of normal and malignant T cells.

ABSTRACT: Adult T-cell leukemia/lymphoma (ATL) is triggered by infection with human T-cell lymphotropic virus-1 (HTLV-1). Here, we describe the reprogramming of pyrimidine biosynthesis in both normal T cells and ATL cells through regulation of uridine-cytidine kinase 2 (UCK2), which supports vigorous proliferation. UCK2 catalyzes the monophosphorylation of cytidine/uridine and their analogues during pyrimidine biosynthesis and drug metabolism. We found that UCK2 was overexpressed aberrantly in HTLV-1-infected T cells but not in normal T cells. T-cell activation via T-cell receptor (TCR) signaling induced expression of UCK2 in normal T cells. Somatic alterations and epigenetic modifications in ATL cells activate TCR signaling. Therefore, we believe that expression of UCK2 in HTLV-1-infected cells is induced by dysregulated TCR signaling. Recently, we established azacitidine-resistant (AZA-R) cells showing absent expression of UCK2. AZA-R cells proliferated normally in vitro, whereas UCK2 knockdown inhibited ATL cell growth. Although uridine and cytidine accumulated in AZA-R cells, possibly because of dysfunction of pyrimidine salvage biosynthesis induced by loss of UCK2 expression, the amount of UTP and CTP was almost the same as in parental cells. Furthermore, AZA-R cells were more susceptible to an inhibitor of dihydroorotic acid dehydrogenase, which performs the rate-limiting enzyme of de novo pyrimidine nucleotide biosynthesis, and more resistant to dipyridamole, an inhibitor of pyrimidine salvage biosynthesis, suggesting that AZA-R cells adapt to UCK2 loss by increasing de novo pyrimidine nucleotide biosynthesis. Taken together, the data suggest that fine-tuning pyrimidine biosynthesis supports vigorous cell proliferation of both normal T cells and ATL cells.

NK314 potentiates antitumor activity with adult T-cell leukemia-lymphoma cells by inhibition of dual targets on topoisomerase II{alpha} and DNA-dependent protein kinase.

Adult T-cell leukemia-lymphoma (ATL) is an aggressive disease, incurable by standard chemotherapy. NK314, a new anticancer agent possessing inhibitory activity specific for topoisomerase IIα (Top2α), inhibited the growth of various ATL cell lines (50% inhibitory concentration: 23-70nM) with more potent activity than that of etoposide. In addition to the induction of DNA double-strand breaks by inhibition of Top2α, NK314 induced degradation of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), resulting in impaired DNA double-strand break repair. The contribution of DNA-PK to inhibition of cell growth was affirmed by the following results: NK314 inhibited cell growth of M059J (a DNA-PKcs-deficient cell line) and M059K (a cell line with DNA-PKcs present) with the same potency, whereas etoposide exhibited weak inhibition of cell growth with M059K cells. A DNA-PK specific inhibitor, NU7026, enhanced inhibitory activity of etoposide on M059K as well as on ATL cells. These results suggest that NK314 is a dual inhibitor of Top2α and DNA-PK. Because ATL cells express a high amount of DNA-PKcs, NK314 as a dual molecular targeting anticancer agent is a potential therapeutic tool for treatment of ATL.

Cancer progression by the okadaic acid class of tumor promoters and endogenous protein inhibitors of PP2A, SET and CIP2A.

PURPOSE: Okadaic acid class of tumor promoters are transformed into endogenous protein inhibitors of PP2A, SET, and CIP2A in human cancers. This indicates that inhibition of PP2A activity is a common mechanism of cancer progression in humans. It is important to study the roles of SET and CIP2A vis-à-vis their clinical significance on the basis of new information gathered from a search of PubMed. RESULTS AND DISCUSSION: The first part of this review introduces the carcinogenic roles of TNF-α and IL-1, which are induced by the okadaic acid class of compounds. The second part describes unique features of SET and CIP2A in cancer progression for several types of human cancer: (1) SET-expressing circulating tumor cells (SET-CTCs) in breast cancer, (2) knockdown of CIP2A and increased PP2A activity in chronic myeloid leukemia, (3) CIP2A and epidermal growth factor receptor (EGFR) activity in erlotinib sensitive- and resistant-non-small cell lung cancer, (4) SET antagonist EMQA plus radiation therapy against hepatocellular carcinoma, (5) PP2A inactivation as a common event in colorectal cancer, (6) prostate cancer susceptibility variants, homeobox transcription factor (HOXB13 T) and CIP2A T, and (7) SET inhibitor OP449 for pre-clinical investigation of pancreatic cancer. In the Discussion, the binding complex of SET is briefly introduced, and overexpression of SET and CIP2A proteins is discussed in relation to age-associated chronic inflammation (inflammaging). CONCLUSION: This review establishes the concept that inhibition of PP2A activity is a common mechanism of human cancer progression and activation of PP2A activity leads to effective anticancer therapy.