Association of Baseline Skeletal Muscle Mass Index With Adverse Events and Rehabilitation Outcomes in Patients Admitted for Rehabilitation.

Objective: To assess the associations of baseline skeletal muscle mass index (SMI) with adverse events and rehabilitation outcomes in patients admitted for rehabilitation. Design: A retrospective cohort study. Participants: The subjects were 409 patients (mean age, 79 years; men, 167 [41%]) undergoing rehabilitation because of neurologic disease, musculoskeletal disorders, or hospital-associated deconditioning. Patients were divided into 2 groups according to the definition of sarcopenia by the Asian Working Group for Sarcopenia: those with low SMI (<7.0 kg/m2 in men and <5.7 kg/m2 in women) and those with high SMI (≥7.0 kg/m2 in men and ≥5.7 kg/m2 in women). Interventions: Not applicable. Main Outcome Measures: The primary outcomes were adverse events including death and acute illness requiring transfer to other hospitals for specialized treatments. The secondary outcomes were rehabilitation outcomes including the efficiency scores (changes in functional independence measure [FIM] score divided by length of stay) of FIM for motor function (FIM-M) and FIM for cognitive function (FIM-C). Results: Of the 409 patients, 299 (73%) had a low SMI. The adjusted hazard ratio (95% confidence interval) of the low SMI group relative to the high SMI group for adverse events was 2.79 (1.06-7.34). There were no significant differences between the 2 groups in FIM-M efficiency scores [mean ± SD, low SMI group: 0.4 (0.58) vs high SMI group: 0.47 (0.54), P=.3] and FIM-C efficiency scores [mean ± SD, 0.05 (0.14) vs 0.06 (0.2), P=.4]. Multiple linear regression models did not show significant associations between the low SMI group and FIM-M efficiency or FIM-C efficiency scores (ß=0.064, P=.3; ß=-0.05, P=.4, respectively). Conclusion: Low baseline SMI was significantly associated with adverse events but not with rehabilitation outcomes in patients undergoing rehabilitation.

Anemia and Rehabilitation Outcomes in Patients Undergoing Convalescent Rehabilitation.

OBJECTIVE: Assessment of the association between anemia and recovery of physical disability in patients with functional impairment. DESIGN: A retrospective cohort study. SETTING: A convalescent rehabilitation ward. PARTICIPANTS: The subjects were patients undergoing convalescent rehabilitation due to neurologic disease, musculoskeletal disorders, or hospital-associated deconditioning. Patients were classified into 3 groups (no anemia; mild anemia [men: hemoglobin of 11.0-12.9 g/dL; women: hemoglobin of 11.0-11.9 g/dL]; and moderate/severe anemia [hemoglobin < 11.0 g/dL]) based on hemoglobin levels. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The study outcomes were functional independence measures for motor function (FIM-M) score at discharge, changes in the FIM-M score between hospital admission and discharge, length of stay, and FIM-M efficiency score (change in FIM-M score divided by length of stay). A linear regression model was constructed to explore the association of anemia with the FIM-M efficiency score. As a subgroup analysis, we constructed a linear regression model to explore the association of anemia with the FIM-M efficiency score in patients with or without stroke. RESULTS: Of 376 consecutive patients with a mean age of 80 years, 258 (69%) had mild or moderate/severe anemia. There were no significant differences between the 3 groups in the FIM-M score at discharge, changes in the FIM-M score, length of stay, and FIM-M efficiency score. A multiple linear regression model showed that the FIM-M efficiency score was not associated with anemia (mild anemia group: ß=-0.02, P=.8; moderate/severe anemia group: ß=-0.005, P=.9). In the subgroup analysis of patients with or without stroke, the multiple regression model also showed no significant association between anemia and FIM-M efficiency score in each group. CONCLUSIONS: Anemia on admission was common among patients in a convalescent rehabilitation ward but was not associated with improvement of FIM-M after rehabilitation.

Association Between Skeletal Muscle Mass Index and Falls in Patients With Functional Impairment.

OBJECTIVE: This study aimed to assess the association between skeletal muscle mass index and falls in patients with functional impairment. DESIGN: This retrospective cohort study was implemented at a convalescent rehabilitation ward. Patients with no measurement of skeletal muscle mass index and bed-ridden patients were excluded from this study. Patients were dichotomized into the low skeletal muscle mass index group and the high skeletal muscle mass index group. The occurrence of fall was assessed according to skeletal muscle mass index groups. RESULTS: Of the 327 included patients, 231 (71%) were assigned to the low skeletal muscle mass index group. In total, 66 patients (20%) experienced at least one fall, and a total of 102 falls occurred. The incidence of falls for the low skeletal muscle mass index group was not significantly greater than that for the high skeletal muscle mass index group (4.9 per 1000 patient-days vs. 4.5 per 1000 patient-days, P = 0.9). Low skeletal muscle mass index was not significantly associated with one or more incidents of falls (odds ratio [95% confidence intervals] = 0.6 [0.3-1.17]). CONCLUSIONS: This study found that skeletal muscle mass index was not significantly associated with falls in patients undergoing convalescent rehabilitation.

Allelic variation of a clubroot resistance gene (Crr1a) in Japanese cultivars of Chinese cabbage (Brassica rapa L.).

Clubroot resistance (CR) is an important trait in Chinese cabbage breeding worldwide. Although Crr1a, the gene responsible for clubroot-resistance, has been cloned and shown to encode the NLR protein, its allelic variation and molecular function remain unknown. Here, we investigated the sequence variation and function of three Crr1a alleles cloned from six CR F1 cultivars of Chinese cabbage. Gain-of-function analysis revealed that Crr1aKinami90_a isolated from the cv. 'Kinami 90' conferred clubroot resistance as observed for Crr1aG004 . Because two susceptible alleles commonly lacked 172 amino acids in the C-terminal region, we investigated clubroot resistance in transgenic Arabidopsis harboring the chimeric Crr1a, in which 172 amino acids of the functional alleles were fused to the susceptible alleles. The fusion of the C-terminal region to the susceptible alleles restored resistance, indicating that their susceptibility was caused by the lack of the C-terminus. We developed DNA markers to detect the two functional Crr1a alleles, and demonstrated that the functional Crr1a alleles were frequently found in European fodder turnips, whereas they were rarely introduced into Japanese CR cultivars of Chinese cabbage. These results would contribute to CR breeding via marker-assisted selection and help our understanding of the molecular mechanisms underlying clubroot resistance.

Discovery of Tolerance to Itraconazole in Japanese Isolates of Aspergillus Section Nigri, Aspergillus tubingensis and Aspergillus welwitschiae, by Microscopic Observation.

Aspergillus section Nigri, a group of black Aspergillus, has several cryptic species that were recently discovered to be intrinsically resistant to azole antifungals. In this study, susceptibility testing of 35 clinical isolates of Aspergillus tubingensis and Aspergillus welwitschiae in Japan was carried out using microdilution method. Strains tolerant to itraconazole in A. tubingensis (14/17 strains) and A. welwitschiae (6/18 strains) were discovered with hyphal growth and conidial germination above the minimal inhibitory concentration by microscopic observation, while no resistant strain was observed macroscopically. In contrast, no strain with reduced susceptibility to voriconazole, posaconazole, and amphotericin-B was found. Further examination may be required to determine the susceptibility of cryptic species in Aspergillus section Nigri to antifungals.

In Vitro Antibacterial Activity of Imipenem/Relebactam against Clinical Isolates in Japan.

Relebactam is a novel ß-lactamase inhibitor of Ambler class A and C ß-lactamases that has been developed in combination with imipenem/cilastatin for the treatment of carbapenem-resistant bacterial infections. In this study, we evaluated the in vitro antibacterial activity of imipenem/relebactam (IMR) against imipenem-nonsusceptible Enterobacterales and Pseudomonas aeruginosa isolates from Japan. Two sets of antibacterial susceptibility tests were conducted according to the susceptibility testing standard of the Clinical and Laboratory Standards Institute. In the first set, antibacterial susceptibility as measured by the MIC50/90 (MIC range) of IMR was assessed for the following 61 imipenem-nonsusceptible strains: 2 Enterobacter cloacae complex (not determined [0.25 µg/mL]), 33 Klebsiella aerogenes (0.5/1 µg/mL [0.5 to 1 µg/mL]), 2 Serratia marcescens (not determined [1 to 2 µg/mL]), and 24 P. aeruginosa (2/128 µg/mL [0.25 to >128 µg/mL]). In the second set, antibacterial susceptibility was assessed for the following 8 imipenem-nonsusceptible strains: 4 Escherichia coli, 1 E. cloacae complex and 3 Klebsiella pneumoniae. The MIC ranges of IMR for these strains were 0.25 to 0.5 µg/mL, 0.5 µg/mL, and 0.5 to 16 µg/mL, respectively. The antibacterial activity of IMR was similar to or lower than that of amikacin and comparable to or greater than those of other reference drugs. In conclusion, IMR has shown antibacterial activity against clinical isolates from Japan and, therefore, is expected to become a new therapeutic option for carbapenem-resistant infections in Japan. IMPORTANCE Carbapenem-resistant Enterobacterales and carbapenem-resistant Pseudomonas aeruginosa strains pose a global threat. Antibacterial activity of imipenem/relebactam (IMR) against clinical isolates of these bacteria from several global regions has been shown; however, as yet there are no reports on Japanese isolates. In this study, we evaluated the in vitro antibacterial activity of IMR against imipenem-nonsusceptible Enterobacterales and Pseudomonas aeruginosa isolates from Japan. The antibacterial activity of IMR against imipenem-nonsusceptible Enterobacterales was generally comparable to that of amikacin (AMK) and comparable to or higher than those of other reference drugs tested. The antibacterial activity of IMR against imipenem-nonsusceptible P. aeruginosa isolates was lower than that of AMK but comparable to or higher than those of other drugs. These results support the use of IMR as a new treatment option for infections due to Enterobacterales and P. aeruginosa strains that are resistant to existing ß-lactams and other antibacterial agents.

Association between Skeletal Muscle Mass Index and Convalescent Rehabilitation Ward Achievement Index in Older Patients.

OBJECTIVE: The aim of the current study was to investigate the association between the skeletal muscle mass index (SMI) and the convalescent rehabilitation ward achievement index (CRWAI) in older patients with functional impairment. METHODS: We conducted a retrospective cohort study at a single rehabilitation center in Japan to include patients admitted to the convalescent rehabilitation ward because of neurological disease, motor disorder, or disuse syndrome. Patients with missing SMI data, those who died or were transferred to other hospitals due to comorbidities, those aged less than 65 years, and those hospitalized for <7 days were excluded from the study. We divided patients into two groups based on their SMI - the high SMI group (SMI ≥7.0 kg/m2 in men and SMI ≥5.7 kg/m2 in women) and the low SMI group (SMI <7.0 kg/m2 in men and SMI <5.7 kg/m2 in women); we then evaluated the association between SMI and the CRWAI score. RESULTS: Of the 319 recruited patients, 84 (26%) were in the high SMI group. The medians and interquartile ranges of the CRWAI scores in the high SMI and low SMI groups were 38.6 (23.1-61) and 31.8 (10.1-57.5), respectively (P=0.029). A high SMI was independently and negatively associated with the CRWAI score (ß=- 0.16, P=0.014). CONCLUSIONS: Our study showed that a high SMI was an independent factor negatively influencing the CRWAI score in older patients in a convalescent rehabilitation ward.

Pinpoint modification strategy for stabilization of single guide RNA.

The clustered regularly interspaced short palindromic repeats-CRISPR associated protein9 (CRISPR-Cas9) system, which includes a single guide RNA (sgRNA) and a Cas9 protein, is an emerging and promising gene editing technology that produces specific changes, including insertions, deletions, or substitutions, in desired targets. This approach can be applied in novel therapeutic areas for multiple cancers and genetic diseases, including Parkinson's disease, sickle cell disease, and muscular dystrophy. However, there are many limitations to its potential application to therapeutics. CRISPR-Cas9 activity without side effects, delivery of CRISPR-Cas9 to the target cell within the desired tissue including liver, lungs, brain and muscle and the expression of Cas9 endonuclease in the target cell are key factors in achieving therapeutic efficacy. Generally, single-stranded RNA is immediately degraded in cells and biological fluids such as serum, as chemically unmodified single-stranded RNA shows extremely poor stability against nuclease degradation. To overcome this limitation, sgRNA is chemically modified to obtain a highly stable sgRNA for efficient gene editing in cells and in vivo. Here, we identified the cleavage site of sgRNA for pinpoint modification in biological tissues using mass spectrometry and improved stability of pinpoint modified sgRNA in these fluids. Although improved efficiency provided by modified sgRNA has already been reported, we identified the cleavage site by mass spectrometry and revealed that the stability increased with the pinpoint modification strategy for the first time in this study. In future studies, the efficiency of pinpoint modification strategy for the potential application of sgRNA by systematic routes, including intravenous and subcutaneous administration will be assessed.

Low immunogenicity of LNP allows repeated administrations of CRISPR-Cas9 mRNA into skeletal muscle in mice.

Genome editing therapy for Duchenne muscular dystrophy (DMD) holds great promise, however, one major obstacle is delivery of the CRISPR-Cas9/sgRNA system to skeletal muscle tissues. In general, AAV vectors are used for in vivo delivery, but AAV injections cannot be repeated because of neutralization antibodies. Here we report a chemically defined lipid nanoparticle (LNP) system which is able to deliver Cas9 mRNA and sgRNA into skeletal muscle by repeated intramuscular injections. Although the expressions of Cas9 protein and sgRNA were transient, our LNP system could induce stable genomic exon skipping and restore dystrophin protein in a DMD mouse model that harbors a humanized exon sequence. Furthermore, administration of our LNP via limb perfusion method enables to target multiple muscle groups. The repeated administration and low immunogenicity of our LNP system are promising features for a delivery vehicle of CRISPR-Cas9 to treat skeletal muscle disorders.

Exercise Training for Patients With Severe Aortic Stenosis in a Convalescent Rehabilitation Ward　- A Retrospective Cohort Study.

Background: Exercise loading is contraindicated for patients with severe aortic stenosis (AS); however, everyday activities mandate the inclusion of a light load. The aim of this study was to investigate the efficacy and safety of exercise training for patients with severe AS who were admitted to a rehabilitation ward because of physical disability. Methods and Results: This historical cohort study was conducted at a single rehabilitation center in Japan. Patients admitted for rehabilitation of physical disability and those who met the definition of severe AS were analyzed. An exercise training program was implemented for patients with disability and severe AS. Cardiovascular symptoms during hospitalization were evaluated. Improvements in the performance of activities of daily living were assessed using the Functional Independence Measure (FIM). Eighteen patients undertook an exercise training program. The median patient age was 87 years (range 76-95 years). Of these patients, 3 died and another 3 were transferred to another hospital due to causes other than the exercise training program. None of the other patients experienced cardiovascular symptoms, and the FIM scores of 12 patients were significantly improved (median [range] scores at admission and discharge of 63 [32-88] and 87 [51-104], respectively; P<0.001). Conclusions: An exercise training program could be applied to patients with severe AS who were admitted for convalescent rehabilitation, because it can improve FIM scores.

Association Between Active Gait Training for Severely Disabled Patients with Nasogastric Tube Feeding or Gastrostoma and Recovery of Oral Feeding: A Retrospective Cohort Study.

PURPOSE: This study evaluates the effect of introducing active gait training (AGT) to patients who are severely disabled with nasogastric tube feeding or gastrostoma on the recovery of oral feeding. PATIENTS AND METHODS: We conducted a historical cohort study at a single rehabilitation center in Japan between January 2013 and December 2019. In this study, 154 severely disabled patients with nasogastric tube feeding or gastrostoma due to neurological diseases or disuse syndrome admitted in a rehabilitation ward were included, and their median age was 84 years. AGT was systematically implemented in August 2016, which consisted of using orthosis or assistance from physical therapists. We compared the recovery of oral feeding between periods before (Pre-AGT) and after (Post-AGT) the introduction of AGT. RESULTS: Among the 154 severely disabled patients included, 59 (38%) were admitted in the Post-AGT period. Twenty-eight (30%) and 54 patients (92%) started gait training in the Pre-AGT and Post-AGT periods, respectively (p < 0.001). Significantly more patients recovered oral feeding in the Post-AGT than in the Pre-AGT periods (49% vs 19%, respectively; p < 0.001). After the introduction of AGT, the adjusted hazard ratio for the recovery of oral feeding was 4.0 (95% confidence interval, 1.9-8.3; p < 0.001). CONCLUSION: After the introduction of AGT to patients, increased recovery of oral feeding was observed in this retrospective evaluation. AGT should be considered for patients with tube feeding to help them recover oral feeding even if patients were severely disabled and required full assistance during gait training.

A new DNA marker CafLess-TCS1 for selection of caffeine-less tea plants.

A clonal line of Camellia taliensis, 'Taliensis-akeme' has a recessive caffeine-less gene. To accelerate breeding of caffeine-less tea cultivars using this gene, DNA markers are indispensable for selecting heterozygotes that do not show a caffeine-less phenotype as parental lines. Therefore, we tried to determine the sequence of the six tea caffeine synthase (TCS) genes to search for polymorphisms and to prepare one of the TCS genes as a selection marker. Six TCS genes and the caffeine-less trait were mapped on the reference linkage map of tea. Strong linkage between the caffeine-less phenotype and TCS1 indicate that it is a promising candidate as a causative gene of the caffeine-less trait. We decided to use a three-nucleotide insertion in TCS1 that can be distinguished by sequencing as a selection marker named 'CafLess-TCS1'. Caffeine-less individuals appeared in the progeny population of caffeine-less heterozygous individuals selected using 'CafLess-TCS1'. These results confirmed that the developed 'CafLess-TCS1' will be an effective selection marker for breeding of caffeine-less tea cultivars.

ASP2397 Is a Novel Natural Compound That Exhibits Rapid and Potent Fungicidal Activity against Aspergillus Species through a Specific Transporter.

Current therapies against invasive pulmonary aspergillosis (IPA) have a limited cure rate. Given that a delay in treatment initiation may be fatal, a new drug with rapid-onset and potent fungicidal activity is needed. The novel cyclic hexapeptide ASP2397 (currently known as VL-2397) exhibited antifungal activity against Aspergillus fumigatus (including azole-sensitive and azole-resistant isolates), A. terreus, and A. flavus at an MIC range of 1 to 4 µg/ml in human serum. Time-kill curve experiments showed that ASP2397 reduced germinated conidia of A. fumigatus by more than 1 log10 CFU within 6 h. In addition, ASP2397 inhibited hyphal elongation from germinated conidia of A. fumigatus, A. terreus, and A. flavus more rapidly than voriconazole. Under conditions of delayed treatment initiation in an IPA mouse model, ASP2397 had efficacy superior to that of posaconazole, with 100% survival and over 1 log10 CFU/g reduction in lung fungal burden. Histopathological investigation of lungs also showed that ASP2397 markedly suppressed disease progression. To clarify its mechanism of action, we generated a UV-induced mutant of A. fumigatus with low susceptibility to ASP2397. The mutant had a point mutation in the siderophore transporter gene sit1, which is absent in mammalian cells. These findings suggest that ASP2397 may improve clinical treatment options for IPA.

Antitumor activity of kinetochore-associated protein 2 siRNA against lung cancer patient-derived tumor xenografts.

It has been widely reported that patient-derived tumor xenografts (PDXs) are more similar to tumor tissues than conventional cancer cell lines. Kinetochore-associated protein 2 (KNTC2) is known to be upregulated specifically in tumor tissues of cancer patients and is recognized as a potential target for cancer therapy. Previously, in vivo antitumor activities of KNTC2 short interfering RNA encapsulated into a lipid nanoparticle (KNTC2-LNP) were reported in orthotopic hepatocellular carcinoma mouse models. However, it remains unclear whether KNTC2-LNP exhibits antitumor activities against lung cancer PDXs. In the present study, the antitumor activities of KNTC2-LNP were clarified in a three-dimensional culture system and a subcutaneous tumor model of lung cancer PDX, LC-60, which was resistant to erlotinib. Growth inhibitory activities of KNTC2-LNP were associated with knockdown activities. Furthermore, KNTC2-LNP also exhibited in vivo antitumor activity against another lung cancer PDX, LC-45, which was sensitive to erlotinib. These results suggest that KNTC2 is a promising target for patients with lung cancer.

Convalescent Rehabilitation for an Elderly Patient with Giant Cell Myocarditis: Case Report.

BACKGROUND: Giant cell myocarditis (GCM) is a rare inflammatory heart disease that, left untreated, rapidly progresses and is fatal without transplantation. Most patients with GCM die of congestive heart failure, but some survive for long periods, often after receiving immunosuppressive therapy. Although rehabilitation is crucial for improving activities of daily living (ADL) after discharge, no reports are available on the rehabilitation of patients with GCM. Here, we report the case of an elderly patient with GCM who was hospitalized for rehabilitation in the recovery phase. CASE: The patient was a 78-year-old woman who was hospitalized because of the exacerbation of chronic heart failure. She was diagnosed with GCM based on the histological findings. The patient was administered immunosuppressive therapy, and intra-aortic balloon pumping, percutaneous cardiopulmonary support, and artificial respiration were performed. Cardiac function gradually improved, and the patient was transferred to our hospital for convalescent rehabilitation. Rehabilitation, including calisthenics, upper and lower limb resistance training, walking, and endurance exercise on a bicycle ergometer, improved the patient's physical function, ADL, and cardiac function. DISCUSSION: Rehabilitation was safely and effectively conducted in a patient with GCM. This single report might be considered inadequate for ascertaining the efficacy of rehabilitation for patients with GCM, but it could be used as a reference when considering rehabilitation for other GCM patients.

Secondary Mania after Cerebral Infarction in the Recovery Phase: Case Report.

INTRODUCTION: Although patients commonly experience psychological disorders such as depression following cerebrovascular events, mania is extremely rare. Here we present a patient who experienced secondary mania while being hospitalized in a convalescent rehabilitation ward following cerebral infarction. CASE: The patient was a 70-year-old man who was hospitalized at our hospital for convalescent rehabilitation after suffering mild right hemiplegia and higher brain dysfunction following cerebral infarction. During hospitalization, the patient experienced a progression-free course. Upon awakening on day 26 after hospitalization, the patient suddenly showed signs of mania. The symptoms included elevated mood, pressured speech, hyperactivity, insomnia, and agitation; these symptoms caused problems in his daily life at the hospital. On day 29 after hospitalization, the patient was referred to a psychiatric hospital as an outpatient. He was diagnosed with organic manic disorder and was hospitalized. The patient was administered lithium carbonate (Limas®; 400 mg daily) and risperidone (Risperdal®; 2 mg daily). Because the mania persisted for more than 1 week, he was diagnosed with secondary mania. His manic state gradually improved, and he was transferred to our hospital. He was able to undergo rehabilitation without any problem and with no exacerbation of mania. The patient was discharged on day 139 after readmission. DISCUSSION: In cases where patients with cerebrovascular disorders display abnormal behavior, it becomes necessary to differentiate between secondary mania and social behavior disorder. Because mania has a negative impact on the patient's hospitalization and convalescence, if secondary mania is suspected, early consideration of psychiatric treatment is required.

Anti-tumor activity of KNTC2 siRNA in orthotopic tumor model mice of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is still one of the major causes of cancer-related death. Kinetochore-associated protein 2 (KNTC2) is specifically upregulated in tumor tissues of HCC patients and recognized as a potential candidate target for the treatment of HCC. However, the relationship between KNTC2 and in vivo tumor growth of HCC is not yet fully understood. Here we encapsulated KNTC2 siRNAs into a lipid nanoparticle (LNP) and investigated their knockdown activity, target engagement marker, anti-tumor activity and hepatotoxicity in an orthotopic HCC model mice of Hep3B-luc cells. Single i.v. administration of KNTC2 siRNA-LNP specifically suppressed the expression levels of both human KNTC2 mRNA and mouse Kntc2 mRNA in tumor tissues. Phosphorylation levels of histone H3 (HH3) at serine 10 in tumor tissues were increased by KNTC2 siRNA-LNP. Repeated administration of KNTC2 siRNA-LNP (twice a week) specifically inhibited the growth of tumor tissues without increasing the plasma AST and ALT levels. Their growth inhibitory activities were consistent with knockdown activities. These data strongly indicated that KNTC2 is a promising target for the treatment of HCC and that phosphorylated HH3 at serine 10 is one of the target engagement markers for KNTC2.

LSD1 Inhibitor T-3775440 Inhibits SCLC Cell Proliferation by Disrupting LSD1 Interactions with SNAG Domain Proteins INSM1 and GFI1B.

T-3775440 is an irreversible inhibitor of the chromatin demethylase LSD1, which exerts antiproliferative effects by disrupting the interaction between LSD1 and GFI1B, a SNAG domain transcription factor, inducing leukemia cell transdifferentiation. Here, we describe the anticancer effects and mechanism of action of T-3775440 in small-cell lung cancer (SCLC). T-3775440 inhibited proliferation of SCLC cells in vitro and retarded SCLC tumor growth in vivo T-3775440 disrupted the interaction between LSD1 and the transcriptional repressor INSM1, thereby inhibiting expression of neuroendocrine-associated genes, such as ASCL1 INSM1 silencing phenocopied the effects of T-3775440 on gene expression and cell proliferation, consistent with the likelihood T-3775440 mediated its effects in SCLC by inhibiting INSM1. T-3775440 also inhibited proliferation of an SCLC cell line that overexpressed GFI1B, rather than INSM1, by disrupting the interaction between LSD1 and GFI1B. Taken together, our results argue that LSD1 plays an important role in neuroendocrine-associated transcription and cell proliferation of SCLC via interactions with the SNAG domain proteins INSM1 and GFI1B. Targeting these critical interactions with LSD1 inhibitors offers a novel rational strategy to therapeutically manage SCLC. Cancer Res; 77(17); 4652-62. ©2017 AACR.

A Novel LSD1 Inhibitor T-3775440 Disrupts GFI1B-Containing Complex Leading to Transdifferentiation and Impaired Growth of AML Cells.

Dysregulation of lysine (K)-specific demethylase 1A (LSD1), also known as KDM1A, has been implicated in the development of various cancers, including leukemia. Here, we describe the antileukemic activity and mechanism of action of T-3775440, a novel irreversible LSD1 inhibitor. Cell growth analysis of leukemia cell lines revealed that acute erythroid leukemia (AEL) and acute megakaryoblastic leukemia cells (AMKL) were highly sensitive to this compound. T-3775440 treatment enforced transdifferentiation of erythroid/megakaryocytic lineages into granulomonocytic-like lineage cells. Mechanistically, T-3775440 disrupted the interaction between LSD1 and growth factor-independent 1B (GFI1B), a transcription factor critical for the differentiation processes of erythroid and megakaryocytic lineage cells. Knockdown of LSD1 and GFI1B recapitulated T-3775440-induced transdifferentiation and cell growth suppression, highlighting the significance of LSD1-GFI1B axis inhibition with regard to the anti-AML effects of T-3775440. Moreover, T-3775440 exhibited significant antitumor efficacy in AEL and AMKL xenograft models. Our findings provide a rationale for evaluating LSD1 inhibitors as potential treatments and indicate a novel mechanism of action against AML, particularly AEL and AMKL. Mol Cancer Ther; 16(2); 273-84. ©2016 AACR.