MORE PANICLES 3, a natural allele of OsTB1/FC1, impacts rice yield in paddy fields at elevated CO2 levels.

Improving crop yield potential through an enhanced response to rising atmospheric CO2 levels is an effective strategy for sustainable crop production in the face of climate change. Large-sized panicles (containing many spikelets per panicle) have been a recent ideal plant architecture (IPA) for high-yield rice breeding. However, few breeding programs have proposed an IPA under the projected climate change. Here, we demonstrate through the cloning of the rice (Oryza sativa) quantitative trait locus for MORE PANICLES 3 (MP3) that the improvement in panicle number increases grain yield at elevated atmospheric CO2 levels. MP3 is a natural allele of OsTB1/FC1, previously reported as a negative regulator of tiller bud outgrowth. The temperate japonica allele advanced the developmental process in axillary buds, moderately promoted tillering, and increased the panicle number without negative effects on the panicle size or culm thickness in a high-yielding indica cultivar with large-sized panicles. The MP3 allele, containing three exonic polymorphisms, was observed in most accessions in the temperate japonica subgroups but was rarely observed in the indica subgroup. No selective sweep at MP3 in either the temperate japonica or indica subgroups suggested that MP3 has not been involved and utilized in artificial selection during domestication or breeding. A free-air CO2 enrichment experiment revealed a clear increase of grain yield associated with the temperate japonica allele at elevated atmospheric CO2 levels. Our findings show that the moderately increased panicle number combined with large-sized panicles using MP3 could be a novel IPA and contribute to an increase in rice production under climate change with rising atmospheric CO2 levels.

[Coagulative complete remission following early gastric cancer resection in a patient with steroid-resistant acquired hemophilia A and nephrotic syndrome].

During laparoscopic cholecystectomy, an 89-year-old man was discovered to have a prolonged APTT. He was transferred to our hospital for a thorough examination because wound bleeding necessitated a reoperation. Based on coagulation factor VIII activity (FVIII:C) of 3.6% and FVIII inhibitor levels of 48.5 BU/ml, he was diagnosed with acquired hemophilia A (AHA). Due to concerns about his advanced age and postoperative infection, immunosuppressive therapy with prednisolone 0.5 mg/kg/day was initiated. His clinical course was favorable, except hemorrhagic shock caused by intramuscular hemorrhage on the right back, although low FVIII inhibitor levels persisted for more than a month; additionally, lower leg edema and increased urinary protein were also observed. He was diagnosed as with AHA and secondary nephrotic syndrome, possibly because of early gastric cancer. As a result, radical endoscopic submucosal dissection (ESD) was performed while a recombinant coagulation factor VIIa preparation was administered. AHA improved rapidly following ESD, and coagulative remission was achieved. Simultaneously, the nephrotic syndrome improved. Because the control of malignant tumors may improve the status of AHA, the timing of malignant tumor intervention must be considered considering the risk of bleeding and infection associated with immunosuppression.

Dose-finding trial of azacitidine as post-transplant maintenance for high-risk MDS: a KSGCT prospective study.

This 3+3 dose-escalation phase I multicenter study investigated the optimal dose of azacitidine (AZA) for post-hematopoietic stem cell transplantation (HSCT) maintenance, which remains unknown in Japan. Recipients of a first HSCT for high-risk myelodysplastic syndromes (MDS, n = 12) or acute myeloid leukemia (AML) with antecedent MDS (n = 3) received post-HSCT AZA maintenance in 2015-2019. The optimal AZA dose was defined as the dose at which 50-70% of patients can complete four cycles without dose-limiting toxicity (DLT). The initial dose level 1 was set as 30 mg/m2 for 5 days per 28-day cycle, and dose levels 0, 2, and 3 were set as 20, 40, and 50 mg/m2. DLT was defined as any grade 3 non-hematological or grade 4 hematological toxicity. The 15 evaluable patients were 55 (37-64) years old. The median observation of the post-HSCT survivors was 935 (493-1915) days. The median number of days post-HSCT to the start of AZA was 101 (59-176). In the first, second, and third cohorts, five of nine patients completed four cycles at dose level 1. In the final cohort, five of six additional patients completed at the same dose. In total, 10 (67%) patients tolerated AZA 30 mg/m2, which was determined as optimal. DLT occurred in five cases: grade 3 hepatotoxicity, pneumonia, enterocolitis, and grade 4 thrombocytopenia and neutropenia. The 2-year overall survival and disease-free survival rates post-HSCT were 77.0% and 73.3%. Post-HSCT AZA maintenance was well-tolerated and merits further evaluation for patients with MDS or AML with antecedent MDS. Trial registration: UMIN000018791.

[Refractory thrombotic thrombocytopenic purpura complicated with multiple cerebral infarction].

Neuropsychiatric symptoms comprise one of the five classic symptoms of autoimmune thrombotic thrombocytopenic purpura (aTTP). Although aTTP is typically transient, it is sometimes complicated by cerebral infarction with residual disability. This report presents the case of an 87-year-old man previously admitted to a different hospital with fever and transient consciousness loss. After receiving platelet transfusion with diagnosis of Evans syndrome, he was transferred to our hospital with worsening consciousness disturbance. He was subsequently diagnosed with aTTP with a PLASMIC score of 6 points, ADAMTS13 activity of less than 0.5%, and its inhibitor of 7.4 BU/ml. Platelet count and consciousness were rapidly improved with plasmapheresis and steroids, but motor aphasia emerged. MRI showed multiple cerebral infarctions, including a large infarction in the left frontal lobe. Thus, unfractionated heparin was administered. When his platelet count dropped once again on the 20th day, rituximab was added. The treatment eventually proved to be successful, and his aTTP remained in remission one year after the onset. Treatment for cerebral infarctions was switched to DOAC, and rehabilitation was continued. However, his ADL has not yet recovered. Advances in aTTP treatment have cured many similar cases. Thus, rituximab is now considered a treatment option for refractory cases. However, ischemic organ damage in acute phase and sequelae are observed. Therefore, early diagnosis and novel therapy are required.

[Spontaneous disappearance of the inhibitor during emicizumab therapy in a patient with mild hemophilia A].

From a young age, a 63-year-old Japanese man had experienced difficulties with hemostasis during tooth extraction and epistaxis and swelling of bruised areas. He had previously been diagnosed with mild hemophilia (FVIII:C 8.5%) at age of 60 due to swelling of a right hip bruise and was administered FVIII concentrate for the first time. He had frequent bleeding around his shoulder joints and was given FVIII concentrates every time, but his hemostasis was poor. He was referred to our hospital because his FVIII activity decreased to<1% and a low-titer inhibitor (2.0 BU/ml) was detected. Because of a shoulder hematoma and new subcutaneous bleeding on both forearms, recombinant FVIIa was used to perform the hemostatic treatment. Following hemostasis, emicizumab was administered subcutaneously every 2 weeks at a dose of 3.0 mg/kg. Approximately 2 months after starting emicizumab, inhibitors were no longer detected, and FVIII activity increased to 8% after 9 months. We encountered a case of mild hemophilia A with an inhibitor that was first diagnosed in old age. The incidence of inhibitors in non-severe hemophilia A is about 10%, and about 70% of those resolves spontaneously. In this case, suppression of bleeding by emicizumab may have contributed to the spontaneous disappearance of the inhibitor.

Pre-conditioning intervention in patients with relapsed or refractory acute lymphoblastic leukemia who underwent allogeneic hematopoietic cell transplantation: a KSGCT multicenter retrospective analysis.

The efficacy and clinical significance of pre-conditioning intervention (PCI) before allogeneic hematopoietic cell transplantation (HCT) in patients with acute lymphoblastic leukemia (ALL) not in remission remain inconclusive. The purpose of this multicenter retrospective study was to clarify the clinical significance of PCI before HCT in patients with non-remission ALL. Patients with non-remission ALL who received HCT between 2005 and 2015 at 16 institutions were included. PCI was objectively defined and classified to three groups according to the intensity of PCI (no, intensive, or moderate). The study cohort consisted of 104 patients with a median age of 38 (range 17-68). A significant decrease of blast percentage in the peripheral blood (PB) was confirmed in both PCI groups, suggesting that PCIs were effective to stabilize the disease activity. The group with moderate PCI had higher nucleated cell count in the BM compared to the group with intensive PCI or the group without PCI. The overall survival (OS) rates of groups with intensive and no PCI showed comparable and significantly better compared to the group with moderate PCI (P = 0.009). Multivariate analysis demonstrated that the OS of moderate PCI group was significantly worse compared to that of intensive PCI group (HR = 2.43, 95% CI: 1.32-4.14, P = 0.004), while the OS of intensive PCI group was comparable to that of the group without PCI. These results suggest that the intensity of PCI rather than the response to PCI may contribute to improve the transplant outcome in patients with ALL not in remission.

Outcomes and Prognostic Factors for Patients with Relapsed or Refractory Acute Lymphoblastic Leukemia Who Underwent Allogeneic Hematopoietic Cell Transplantation: A KSGCT Multicenter Analysis.

A multicenter retrospective study was performed to evaluate the prognostic factors in 104 patients with relapsed or refractory acute lymphoblastic leukemia (ALL), who underwent allogeneic hematopoietic cell transplantation (HCT) between 2005 and 2015. The median age was 38 (range, 17 to 68), and the median blast fraction in peripheral blood and bone marrow was 1% (range, 0 to 99%) and 52% (range, 0 to 100%), respectively. With a median follow-up of 47 months (range, 8.3 to 105 months), overall survival (OS), nonrelapse mortality, and relapse mortality at 1 year were 25%, 44%, and 31%, respectively. Multivariate analysis demonstrated independent predictors for poor OS, including nuclear cell count in the bone marrow ≥10 × 104/µL (hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.33 to 3.43; P = .002), elevated lactate dehydrogenase level (HR, 1.66; 95% CI, 1.05 to 2.62; P = .031), and no primary induction failure (HR, 2.05; 95% CI, 1.11 to 3.78; P = .022). A prognostic scoring index was designed based on these survival predictors. At 2 years, OS was 28%, 14%, and 0% for good (score 0 or 1; n = 47), intermediate (score 2; n = 40), and poor (score 3; n = 17), respectively (P < .001). This scoring system may be useful in identifying the patient population for which allogeneic HCT is least beneficial in advanced stages of ALL.

Expression of the CCCH-tandem zinc finger protein gene OsTZF5 under a stress-inducible promoter mitigates the effect of drought stress on rice grain yield under field conditions.

Increasing drought resistance without sacrificing grain yield remains an ongoing challenge in crop improvement. In this study, we report that Oryza sativa CCCH-tandem zinc finger protein 5 (OsTZF5) can confer drought resistance and increase grain yield in transgenic rice plants. Expression of OsTZF5 was induced by abscisic acid, dehydration and cold stress. Upon stress, OsTZF5-GFP localized to the cytoplasm and cytoplasmic foci. Transgenic rice plants overexpressing OsTZF5 under the constitutive maize ubiquitin promoter exhibited improved survival under drought but also growth retardation. By introducing OsTZF5 behind the stress-responsive OsNAC6 promoter in two commercial upland cultivars, Curinga and NERICA4, we obtained transgenic plants that showed no growth retardation. Moreover, these plants exhibited significantly increased grain yield compared to non-transgenic cultivars in different confined field drought environments. Physiological analysis indicated that OsTZF5 promoted both drought tolerance and drought avoidance. Collectively, our results provide strong evidence that OsTZF5 is a useful biotechnological tool to minimize yield losses in rice grown under drought conditions.

PARP1 V762A polymorphism affects the prognosis of myelodysplastic syndromes.

OBJECTIVE: Myelodysplastic syndromes (MDS), caused by various genetic mutations in hematopoietic stem cells, are associated with highly variable outcomes. Poly (ADP-ribose) polymerase-1 (PARP1) plays an important role in DNA damage repair and contributes to the progression of several types of cancer. Here, we investigated the impact of PARP1 V762A polymorphism on the susceptibility to and prognosis of MDS. METHODS: Samples collected from 105 MDS patients and 202 race-matched healthy controls were subjected to polymerase chain reaction-restriction fragment length polymorphism for genotyping. RESULTS: The allele and genotype frequencies of PARP1 V762A did not differ between MDS patients and the control group. However, MDS patients with the PARP1 V762A non-AA genotype, which is associated with high gene activity, had shorter overall survival rates (P = .01) than those with the AA genotype. Multivariate analysis of overall survival also revealed PARP1 V762A non-AA genotype as a poor prognostic factor (P = .02). When patients were analyzed according to treatment history, the PARP1 V762A non-AA genotype was only associated with poor survival in patients who had received treatment (P = .02). CONCLUSION: PARP1 V762A polymorphism may be an independent prognostic factor for MDS, and a predictive biomarker for MDS treatment.

[Mediastinal abscess due to Aspergillus in a patient with atypical chronic myeloid leukemia, BCR-ABL1-negative].

A 64-year-old male presented with a rapidly growing anterior mediastinal mass during the clinical course of atypical chronic myeloid leukemia. A needle biopsy performed for suspected myeloid sarcoma revealed the presence of Aspergillus abscess. Early diagnosis of mediastinal abscesses, which are associated with a high mortality rate, can prevent the progression of severity. Infectious abscesses should be considered for prompt qualitative diagnosis in patients with mediastinal masses. Thymoma, germ cell tumor, and malignant lymphoma are the most common anterior mediastinal tumors, whereas infectious abscesses should also be considered when myeloid sarcoma is suspected in patients with an underlying myeloid tumor.

[Successful management of acquired factor V deficiency developing shortly after induction of hemodialysis].

Autoimmune factor V deficiency (AiF5D) is caused by autoantibodies to coagulation factor V (FV); its clinical manifestations range from asymptomatic to fatal hemorrhage. Herein, we report the case of a 68-year-old man who was diagnosed with end-stage renal disease at the time of a femoral fracture and developed AiF5D after initiating hemodialysis. A wound infection that occurred after joint replacement was treated with antibiotics; however, it was poorly controlled. One month after the procedure, his coagulation time prolonged. The infection was improved by debridement and antibiotics; however, the coagulation time was not decreased and poor hemostasis at the shunt was still persistent. Because ELISA detected anti-FV-binding IgG with FV activity of <2.8% and FV inhibitor levels were 11.8 BU/ml, AiF5D was diagnosed. Oral prednisolone (PSL) was started. Dialysis was initially performed without anticoagulants, but blood clots were not found in the circuit. Anticoagulants were resumed when the coagulation time decreased. After achieving complete remission, PSL dose was tapered and finally discontinued. Few reports have described the management of AiF5D via dialysis. We consider that our report would be useful for the management of patients with similar manifestations.

Integration of danger peptide signals with herbivore-associated molecular pattern signaling amplifies anti-herbivore defense responses in rice.

Plant defense against herbivores is modulated by herbivore-associated molecular patterns (HAMPs) from oral secretions (OS) and/or saliva of insects. Furthermore, feeding wounds initiate plant self-damage responses modulated by danger-associated molecular patterns (DAMPs) such as immune defense-promoting plant elicitor peptides (Peps). While temporal and spatial co-existence of both patterns during herbivory implies a possibility of their close interaction, the molecular mechanisms remain undetermined. Here we report that exogenous application of rice (Oryza sativa) peptides (OsPeps) can elicit multiple defense responses in rice cell cultures. Specific activation of OsPROPEP3 gene transcripts in rice leaves by wounding and OS treatments further suggests a possible involvement of the OsPep3 peptide in rice-herbivore interactions. Correspondingly, we found that simultaneous application of OsPep3 and Mythimna loreyi OS significantly amplifies an array of defense responses in rice cells, including mitogen-activated protein kinase activation, and generation of defense-related hormones and metabolites. The induction of OsPROPEP3/4 by OsPep3 points to a positive auto-feedback loop in OsPep signaling which may contribute to additional enhancement of defense signal(s). Finally, the overexpression of the OsPep receptor OsPEPR1 increases the sensitivity of rice plants not only to the cognate OsPeps but also to OS signals. Our findings collectively suggest that HAMP-DAMP signal integration provides a critical step in the amplification of defense signaling in plants.

Prognostic impact of trisomy 21 in follicular lymphoma.

The chromosomal abnormalities associated with follicular lymphoma (FL) prognosis are not fully elucidated. Here, we evaluated the pattern of chromosomal abnormalities in FL, and clarified the correlations between the cytogenetic features and clinical outcome. Cytogenetic analysis was performed using standard methods of Giemsa-banding at diagnosis for 201 FL patients admitted to our hospitals between 2001 and 2013. The identified chromosomal abnormalities were: t(14;18)(q32;q21) (59·2%), +X (17·9%), del(6)(q)/-6 (16·9%), +7 (14·4%), abnormality of 1q12-21/1q (12·9%), del(13)(q)/-13 (11·9%), abnormality of 3q27 (10·4%), abnormality of 10q22-24 (10·0%), +12/dup(12)(q) (10·0%), abnormality of 1p21-22/1p (9·0%), +18 (9·0%), del(17)(p)/-17 (5·0%), and a complex karyotype (54·7%). Patients with trisomy 21 had a significantly shorter progression-free survival (P = 0·00171) and overall survival (OS) (P < 0·001) than those without trisomy 21; additionally, patients with trisomy 21 in the rituximab-treated cohort also had a significantly shorter OS (P = 0·000428). Multivariate analysis identified trisomy 21 as an independent risk factor in our cohorts with or without t(14;18) (P = 0·015). In conclusion, the presence of trisomy 21 was an independent risk factor for in FL. Chromosomal analysis of FL patients at diagnosis can provide useful information about their expected survival.

[Thyroid storm and exacerbation of autoimmune hemolytic anemia following childbirth].

A 32-year-old woman was diagnosed with autoimmune hemolytic anemia (AIHA) at 12 weeks of a pregnancy examination and followed up closely without treatment. At 40 weeks of gestation, she underwent emergency caesarean section because of premature rupture. On postoperative day one, the patient exhibited worsening hemolysis and tachycardia and developed high-output heart failure; she was diagnosed with Basedow disease based on the tachycardia pattern and thyroid storm based on the presence of hyperthyroidism, fever, tachycardia, and heart failure. She was administered thiamazole and potassium iodide, which improved her thyroid function, hemolytic anemia, and heart failure. AIHA is rarely associated with Basedow disease, and hemolytic anemia can be aggravated by hyperthyroidism. In pregnant women with AIHA, management of hyperthyroidism is crucial as delivery can lead to thyroid storm.

[Recurrence of acquired factor V inhibitor after four years of remission].

Acquired factor V inhibitor (AFV-I) is a rare bleeding disorder wherein autoantibodies are developed against coagulation factor V (FV). The clinical symptoms are variable, from laboratory abnormalities without bleeding to life-threatening hemorrhage. We report herein the case of a patient with AFV-I with two relapses 4 years after the first remission. A 66-year-old male was diagnosed with AFV-I in March 20XX-4. He was treated with prednisolone (PSL) at 50 mg/day and achieved remission within 1 month. PSL dose was tapered to oral administration of 2.5 mg every other day, and long-term remission was maintained. He had been treated with dual antiplatelet therapy (DAPT) for old myocardial infarction. FV activity was markedly reduced to 3.4%, and FV inhibitor was detected (1.0 BU/ml) in May 20XX. We followed the patient without increasing the treatment dose for 2 months, but no spontaneous improvement was seen. Because DAPT was ongoing, we judged that the bleeding risk was high, although only minor bleeding symptoms appeared. PSL was therefore increased to 40 mg/day in June. FV inhibitor rapidly disappeared. When PSL dose was gradually decreased, FV activity decreased, and subcutaneous bleeding occurred in February 20XX＋1. PSL dose was increased again for the second relapse, and the patient achieved remission. Few reports have described recurrent AFV-I, and no cases of two relapses have been reported. We believe that this case report is useful for examining the long-term management of AFV-I.

Genome-wide association and gene validation studies for early root vigour to improve direct seeding of rice.

Elucidation of the genetic control of rice seedling vigour is now paramount with global shifts towards direct seeding of rice and the consequent demand for early vigour traits in breeding programmes. In a genome-wide association study using an indica-predominant diversity panel, we identified quantitative trait loci (QTLs) for root length and root number in rice seedlings. Among the identified QTLs, one QTL for lateral root number on chromosome 11, qTIPS-11, was associated with a 32.4% increase in lateral root number. The locus was validated in independent backgrounds, and a predicted glycosyl hydrolase, TIPS-11-9, was identified as the causal gene for observed phenotypic differences. TIPS-11-9 was differentially expressed in emerging lateral roots of contrasting qTIPS-11 haplotypes, which was likely due to differences in cis-regulatory elements and auxin responsiveness. Abolishment of Tips-11-9 function through T-DNA insertion in a qTIPS-11-positive background resulted in a reduction of lateral root number, which negatively affected biomass accumulation, particularly under phosphorous-limiting conditions. Marker-assisted introgression of qTIPS-11 into modern indica varieties will aid in the generation of varieties adapted to direct seeding and thus facilitate the adoption of direct seeding practices in tropical Asia.

Clonal evolution detected with conventional cytogenetic analysis is a potent prognostic factor in adult patients with relapsed AML.

We retrospectively investigated 144 patients with relapsed acute myeloid leukemia (AML) to clarify predisposing factors and the prognostic impact of acquisition of additional cytogenetic abnormalities (ACA) at the first relapse. Additional cytogenetic abnormalities are recognized as clonal evolution at the cytogenetic level. Fifty-nine patients (41%) acquired ACA at the first relapse. The incidences of ACA acquisition varied depending on cytogenetic abnormalities at initial diagnosis. Multivariate analysis identified t(8;21), complex karyotype, and a duration of fewer than 12 months of complete remission as independent predisposing factors for ACA acquisition. Notably, patients with ACA acquisition showed a significantly lower second complete remission rate compared with those without ACA acquisition (20.0% vs 72.5%, respectively, P < .001). Furthermore, the 3-year overall survival rates after the first relapse were significantly different between patients with and without ACA acquisition (8.5% vs 36.8%, respectively, P < .001). This prognostic significance was confirmed with multivariate analysis. The hazard ratio of ACA acquisition was similar or higher than reported prognostic factors for relapsed AML patients. These findings suggested that clonal evolution detected with conventional cytogenetic analysis at the first relapse induces severe chemo-refractory characteristics in AML cells and should be considered as a potent prognostic factor when evaluating accurate prognosis in relapsed AML patients.

[Giant hemophilic pseudotumors in brothers with non-severe hemophilia B].

Hemophilic pseudotumors can occur in patients with hemophilia because of recurrent bleeding and poor hemostasis. A man in his 30s with hemophilia B and human immunodeficiency virus/hepatitis C virus co-infection complicated by liver cirrhosis presented with a large pseudotumor in the left iliopsoas muscle. However, resting to stop bleeding was difficult with his daily work. Osteolytic changes in the left ilium progressed over 8 years. A large osteolytic pseudotumor in the pelvis was also incidentally identified in his younger brother during his 30s. The same mutations in F9 (p. Arg294Gln, hemizygous mutation) associated with a non-severe phenotype were detected in both brothers. The clinical courses of the brothers suggested that large pseudotumors can occur in patients with non-severe hemophilia and underline the importance of patient education.

Overexpression of B-cell lymphoma 6 alters gene expression profile in a myeloma cell line and is associated with decreased DNA damage response.

B-cell lymphoma 6 (BCL6) attenuates DNA damage response (DDR) through gene repression and facilitates tolerance to genomic instability during immunoglobulin affinity maturation in germinal center (GC) B cells. Although BCL6 expression is repressed through normal differentiation of GC B cells into plasma cells, a recent study showed the ectopic expression of BCL6 in primary multiple myeloma (MM) cells. However, the functional roles of BCL6 in MM cells are largely unknown. Here, we report that overexpression of BCL6 in a MM cell line, KMS12PE, induced transcriptional repression of ataxia telangiectasia mutated (ATM), a DDR signaling kinase, which was associated with a reduction in γH2AX formation after DNA damage. In contrast, transcription of known targets of BCL6 in GC B cells was not affected, suggesting a cell type-specific function of BCL6. To further investigate the effects of BCL6 overexpression on the MM cell line, we undertook mRNA sequence analysis and found an upregulation in the genomic mutator activation-induced cytidine deaminase (AID) with alteration in the gene expression profile, which is suggestive of de-differentiation from plasma cells. Moreover, interleukin-6 exposure to KMS12PE led to upregulation of BCL6 and AID, downregulation of ATM, and attenuation of DDR, which were consistent with the effects of BCL6 overexpression in this MM cell line. Taken together, these results indicated that overexpression of BCL6 alters gene expression profile and confers decreased DDR in MM cells. This phenotypic change could be reproduced by interleukin-6 stimulation, suggesting an important role of external stimuli in inducing genomic instability, which is a hallmark of MM cells.

Long non-coding RNA MALAT1 is an inducible stress response gene associated with extramedullary spread and poor prognosis of multiple myeloma.

Extramedullary myeloma (EMM) occurs when myeloma develops outside the bone marrow; it often develops after chemotherapy and is associated with the acquisition of chemo-resistance and a fatal course. The mechanisms underlying extramedullary spread have not yet been fully elucidated. MALAT1 is a highly abundantly and ubiquitously expressed long non-coding RNA that plays important roles in cancer metastasis. The aims of this study were to clarify the association of MALAT1 with EMM and to elucidate the underlying mechanism of EMM formation under chemotherapeutic pressure. MALAT1 expression was significantly higher in multiple myeloma (MM) than in monoclonal gammopathy of undetermined significance. Furthermore, MALAT1 expression was markedly higher in EMM compared with that in corresponding intramedullary myeloma cells. A higher MALAT1 level was associated with shorter overall and progression-free survival. MALAT1 expression level was positively correlated with expression of HSP90AA1, HSP90AB1 and HSP90B1 but not with TP53 expression. MALAT1 was significantly upregulated by bortezomib and doxorubicin. Considering the known functions of MALAT1, our results suggest that it acts as a stress response gene that is upregulated by chemotherapy, thereby linking chemotherapy to EMM formation. Elucidating the biological implication of long non-coding RNA contributes to deeper understanding concerning the pathogenesis and investigation of novel therapeutic targets for MM.