The clinical characteristics, gene mutations and outcomes of myelodysplastic syndromes with diabetes mellitus.

PURPOSE: Diabetes mellitus (DM) is the second most common comorbidity in myelodysplastic syndromes (MDS). The purpose of the study was to investigate the clinical characteristics of MDS patients with DM. METHODS: A retrospective analysis was performed on the clinical data of 890 MDS patients with or without DM. Clinical data, including genetic changes, overall survival (OS), leukemia-free survival (LFS) and infection, were analyzed. RESULTS: Among 890 patients, 184 (20.7%) had DM. TET2 and SF3B1 mutations occurred more frequently in the DM group than those in the non-DM group (p = 0.0092 and p = 0.0004, respectively). Besides, DM was an independent risk factor for infection (HR 2.135 CI 1.451-3.110, p = 0.000) in MDS. Compared to non-DM patients, MDS patients with DM had poor OS and LFS (p = 0.0002 and p = 0.0017, respectively), especially in the lower-risk group. While in multivariate analysis, DM did not retain its prognostic significance and the prognostic significance of infection was maintained (HR 2.488 CI 1.749-3.538, p = 0.000). CONCLUSIONS: MDS patients with DM have an inferior prognosis which may due to higher infection incidence, with TET2 and SF3B1 mutations being more frequent in those cases.

ROBO1 deficiency impairs HSPC homeostasis and erythropoiesis via CDC42 and predicts poor prognosis in MDS.

Myelodysplastic syndrome (MDS) is a group of clonal hematopoietic neoplasms originating from hematopoietic stem progenitor cells (HSPCs). We previously identified frequent roundabout guidance receptor 1 (ROBO1) mutations in patients with MDS, while the exact role of ROBO1 in hematopoiesis remains poorly delineated. Here, we report that ROBO1 deficiency confers MDS-like disease with anemia and multilineage dysplasia in mice and predicts poor prognosis in patients with MDS. More specifically, Robo1 deficiency impairs HSPC homeostasis and disrupts HSPC pool, especially the reduction of megakaryocyte erythroid progenitors, which causes a blockage in the early stages of erythropoiesis in mice. Mechanistically, transcriptional profiling indicates that Cdc42, a member of the Rho-guanosine triphosphatase family, acts as a downstream target gene for Robo1 in HSPCs. Overexpression of Cdc42 partially restores the self-renewal and erythropoiesis of HSPCs in Robo1-deficient mice. Collectively, our result implicates the essential role of ROBO1 in maintaining HSPC homeostasis and erythropoiesis via CDC42.

S100a9 deficiency accelerates MDS-associated tumor escape via PD-1/PD-L1 overexpression.

In recent studies, the tolerable safety profile and positive bone marrow (BM) response suggest a beneficial use of anti-PD-1 agents in the treatment of Myelodysplastic Syndromes (MDS), but the underlying mechanism is still unknown. MDS is mainly characterized by ineffective hematopoiesis, which may contribute to inflammatory signaling or immune dysfunction. Our previous studies focused on inflammatory signaling, and the results showed that S100a9 expression was higher in low-risk MDS and lower in high-risk MDS. In this study, we combine the inflammatory signaling and immune dysfunction. SKM-1 cells and K562 cells co-cultured with S100a9 acquire apoptotic features. Moreover, we confirm the inhibitory effect of S100a9 on PD-1/PD-L1. Importantly, PD-1/PD-L1 blockade and S100a9 can both activate the PI3K/AKT/mTOR signaling pathway. The cytotoxicity is higher in lower-risk MDS-lymphocytes than in high-risk MDS-lymphocytes, and S100a9 partially rescues the exhausted cytotoxicity in lymphocytes. Our study demonstrates that S100a9 may inhibit MDS-associated tumor escape via PD-1/PD-L1 blockade through PI3K/AKT/mTOR signaling pathway activation. Our findings indicate the possible mechanisms by which anti-PD-1 agents may contribute to the treatment of MDS. These insights may provide mutation-specific treatment as a supplementary therapy for MDS patients with high-risk mutations, such as TP53, N-RAS or other complex mutations.

The use of carbon monoxide breath test to detect the effect of iron overload on erythrocyte lifespan in MDS.

Objective: To investigate the effect of iron overload (IO) on red blood cell (RBC) lifespan in MDS patients with the use of carbon monoxide breath test. Methods: The red blood cell lifespan of 93 patients with myelodysplastic syndrome (MDS) and 22 healthy volunteers in the control group were measured by alveolar gas carbon monoxide (CO) assay, with the detection of liver iron concentration, iron metabolism index, erythropoietin (EPO) concentration, peripheral blood inflammatory cytokines, etc. The MDS patients were divided into the severe IO group, mild IO group and non IO group according to liver iron concentration. The effect of IO on RBC lifespan was analyzed in MDS patients. Results: The RBC lifespan of MDS patients in the severe IO group was significantly lower than that in the mild IO group (p<0.05), while the RBC life span in the mild IO group was significantly lower than that in the non IO group (p<0.05). The expression of inflammatory cytokines in the severe IO group was significantly higher than that of the mild and non IO groups. After receiving iron removal treatment(ICT), the expression of inflammatory cytokines was decreased significantly, and the RBC lifespan was significantly prolonged (p<0.05).Besides, liver iron concentration was significantly positively correlated with EPO concentration, while EPO concentration was significantly negatively correlated with RBC lifespan, especially in the MDS-RS subgroup. The RBC lifespan in the EPO>1000 group was significantly lower than that in the EPO<1000 group. Conclusion: IO can shorten RBC lifespan in MDS patients, which may be result from the increase of endogenous EPO and the over-expression of inflammatory cytokines. After ICT, the ineffective hematopoiesis caused by increased EPO may reduced and the decrease of inflammatory cytokine may significantly prolong the RBC lifespan in MDS patients.

Bone Marrow Fibrosis at Diagnosis and during the Course of Disease Is Associated with TP53 Mutations and Adverse Prognosis in Primary Myelodysplastic Syndrome.

The prognostic significance of bone marrow fibrosis (MF) grade in patients with myelodysplastic syndrome (MDS) is still debated and the molecular changes remain unclear. In our large cohort, a normal reticulum was found in 211 (25.9%) patients, whereas MF1, MF2 and MF3 were detected in 478 (58.7%), 90 (11.1%) and 35 (4.3%) patients at initial diagnosis, respectively. Patients with MF often correlated with some poor prognostic characteristics, including older age, anemia, unfavorable karyotype, higher BM blast and a higher IPSS-R category. For the entire cohort, the median OS was not reached, 30, 16 and 15 months for patients with MF 0, 1, 2 and 3, respectively. After adjusting for IPSS-R, the hazard ratio for mortality was 1.56 (95% CI, 1.18-2.06) for patients with MF1, 2.29 (95% CI, 1.61-3.27) for patients with MF2 and 2.75 (95% CI, 1.69-4.49) for patients with MF3 compared with those with MF0. The mutational landscape of 370 patients showed that TP53, U2AF1 and KMT2D mutations were more frequent in patients with MF2-3. In addition, of the 408 patients with MF0-1, 62 patients (15.1%) progressed to MF2-3 during the follow-up interval. The clinical features, mutation landscape and prognosis of patients with progressed fibrosis were similar to those of patients with MF2-3 at diagnosis. We concluded that BM fibrosis (MF1, 2 and 3) was an adverse prognosis feature in primary MDS and correlated with TP53 mutations both at the time of initial diagnosis and during the course of the disease. Therefore, BM fibrosis should be included in the revised prognostic scoring system and carefully considered in treatment selection.

Integrated traditional Chinese and conventional medicine in the treatment of anemia due to lower-risk myelodysplastic syndrome: study protocol for a randomized placebo-controlled trial.

BACKGROUND: Erythropoiesis and iron homeostasis are closely related; anemia due to lower-risk myelodysplastic syndromes (MDS) remains difficult to treat. In the last decade, we have been committed to improving the regulation of iron metabolism using traditional Chinese medicine (TCM). Previous studies have found that the TCM Yi Gong San (YGS) can reduce the expression of transferrin by inhibiting hepcidin overexpression caused by inflammation, promote the outward transfer of intracellular iron, and improve the symptoms of anemia. Here, our study aimed to compare the efficacy of a conventional drug with YGS with that of conventional medicine with placebo to provide a scientific basis for making clinical decisions. METHODS: A prospective, multicenter, double-blinded, randomized controlled clinical trial will be conducted to evaluate the therapeutic efficacy of conventional medicine combined with YGS with that of conventional medicine alone in the treatment of MDS. A total of 60 patients would be enrolled in this study, with each treatment group (conventional medicine + YGS and conventional medicine + placebo) comprising 30 patients. Oral medication would be administered twice daily for 3 months. All patients would be followed up throughout the 3-month period. The primary outcome was measured by assessing blood hemoglobin level. The secondary outcome was measured by assessing TCM symptom score, iron metabolism, hepcidin levels, and inflammatory factors. DISCUSSION: This trial would aim to demonstrate the effectiveness and feasibility of YGS in the treatment of lower-risk MDS anemia, as well as its impact on inflammatory factors and iron metabolism in patients with lower-risk MDS. TRIAL REGISTRATION: Chinese Clinical Trials Registry ( http://www.chictr.org.cn/ ) ChiCTR1900026774 .  Registered on October 21, 2019.

Dynamics of epigenetic regulator gene BCOR mutation and response predictive value for hypomethylating agents in patients with myelodysplastic syndrome.

BACKGROUND: BCOR (BCL6 corepressor) is an epigenetic regulator gene involved in the specification of cell differentiation and body structure development. Recurrent somatic BCOR mutations have been identified in myelodysplastic syndrome (MDS). However, the clinical impact of BCOR mutations on MDS prognosis is controversial and the response of hypomethylating agents in MDS with BCOR mutations (BCORMUT) remains unknown. RESULTS: Among 676 MDS patients, 43 patients (6.4%) harbored BCOR mutations. A higher frequency of BCOR mutations (8.7%) was investigated in patients with normal chromosome, compared to 4.2% in patients with abnormal karyotype (p = 0.040). Compared to the BCORWT patients, the BCORMUT patients showed a higher ratio of refractory anemia with excess blasts subset (p = 0.008). The most common comutations with BCOR genes were ASXL1 (p = 0.002), DNMT3A (p = 0.114) and TET2 (p = 0.148). When the hierarchy of somatic mutations was analyzed, BCOR mutations were below the known initial mutations (ASXL1 or TET2) but were above U2AF1 mutations. Transformation-free survival was significantly shorter in BCORMUT patients than that in BCORWT patients (16 vs. 35 months; p = 0.035). RNA-sequencing was performed in bone marrow mononuclear cells from BCORMUT and BCORWT patients and revealed 2030 upregulated and 772 downregulated genes. Importantly, HOXA6, HOXB7, and HOXB9 were significantly over-expressed in BCORMUT patients, compared to BCORWT patients. Eight of 14 BCORMUT patients (57.1%) achieved complete remission (CR) with decitabine treatment, which was much higher than that in BCORWT patients (28.7%, p = 0.036). Paired sequencing results (before and after decitabine) showed three of 6 CR patients lost the mutated BCOR. The median survival of CR patients with a BCORMUT was 40 months, which was significantly longer than that in patients with BCORWT (20 months, p = 0.036). Notably, prolonged survival was observed in three BCORMUT CR patients even without any subsequent therapies. CONCLUSIONS: BCOR mutations occur more frequently in CN MDS patients, predicting higher risk of leukemia transformation. BCORMUT patients showed a better response to decitabine and achieved longer post-CR survival.

Comparative Study on Iron Content Detection by Energy Spectral CT and MRI in MDS Patients.

Objective: The purpose of this study was to identify the difference between dual energy spectral computed tomography (DECT) and magnetic resonance imaging (MRI) used to detect liver/cardiac iron content in Myelodysplastic syndrome (MDS) patients with differently adjusted serum ferritin (ASF) levels. Method: Liver and cardiac iron content were detected by DECT and MRI. Patients were divided into different subgroups according to the level of ASF. The receiver operating characteristic curve (ROC) analysis was applied in each subgroup. The correlation between iron content detected by DECT/MRI and ASF was analyzed in each subgroup. Result: ROC curves showed that liver virtual iron content (LVIC) Az was significantly less than liver iron concentration (LIC) Az in the subgroup with ASF < 1,000 ng/ml. There was no significant difference between LVIC Az and LIC Az in the subgroup with 1,000 ≤ ASF < 2,500 ng/ml and 2,500 ≤ ASF < 5,000 ng/ml. LVIC Az was significantly higher than LIC Az in the subgroup with ASF <5,000 and 5,000 ≤ ASF ng/ml. In patients undergoing DECT and MRI examination on the same day, ASF was significantly correlated with LVIC, whereas no significant correlation was observed between ASF and LIC. After removing the data of ASF > 5,000 mg/L in LIC, LIC became correlated with ASF. There was no significant difference between the subgroup with 2,500 ≤ ASF < 5,000 ng/ml and 5,000 ng/ml ≤ ASF in LIC expression. Furthermore, both LIC and liver VIC had significant correlations with ASF in patients with ASF < 2,500 ng/ml, while LVIC was still correlated with ASF, LIC was not correlated with ASF in patients with 2,500 ng/ml ≤ ASF. Moreover, neither cardiac VIC nor myocardial iron content (MIC) were correlated with ASF in these subgroups. Conclusion: MRI and DECT were complementary to each other in liver iron detection. In MDS patients with high iron content, such as ASF ≥ 5,000 ng/ml, DECT was more reliable than the MRI in the assessment of iron content. But in patients with low iron content, such as ASF < 1,000 ng/ml, MRI is more reliable than DECT. Therefore, for the sake of more accurately evaluating the iron content, the appropriate detection method can be selected according to ASF.

Analysis of the influencing factors related to liver and cardiac iron overload in MDS patients detected by MRI in the real world.

OBJECTIVES: We aim to explore and analyze the related influencing factors of liver and cardiac iron overload in MDS patients detected by magnetic resonance imaging (MRI). METHODS: We have detected cardiac T2* and liver T2* by MRI in 105 MDS patients. Among them, 20 patients accepted MRI examination before and after iron chelation therapy (ICT). Results: We found that adjusted ferritin (ASF) was significantly correlated with liver T2* and cardiac T2*. RBC transfusion volume, brain natriuretic peptide (BNP) and age were the related factors of cardiac T2*, while RBC transfusion volume and erythropoietin (EPO) were related factors of liver T2*. After ICT, the changes of ASF and liver T2* were earlier than cardiac T2*. Chronic hepatitis but virus copy normal's has no significant effect on liver iron deposition. CONCLUSION: These results showed special attention should be paid to these related influencing factors of liver and cardiac T2* expression when we evaluated iron overload and detected the efficacy of ICT in MDS patients.

Decitabine Induces Change of Biological Traits in Myelodysplastic Syndromes via FOXO1 Activation.

Decitabine (DAC) is considered to be a profound global DNA demethylation, which can induce the re-expression of silenced tumor suppressor genes. Little is known about the function of tumor suppressor gene FOXO1 in myelodysplastic syndromes (MDS). To address this issue, the study firstly investigated differentially expressed genes (DEGs) for DAC treatment in MDS cell lines, then explored the role of FOXO1 through silencing its expression before DAC treatment in MDS. The results showed that FOXO1 exists in a hyperphosphorylated, inactive form in MDS-L cells. DAC treatment both induces FOXO1 expression and reactivates the protein in its low phosphorylation level. Additionally, the results also demonstrated that this FOXO1 activation is responsible for the DAC-induced apoptosis, cell cycle arrest, antigen differentiation, and immunoregulation in MDS-L cells. We also demonstrated DAC-induced FOXO1 activation upregulates anti-tumor immune response in higher-risk MDS specimens. Collectively, these results suggest that DAC induces FOXO1 activation, which plays an important role in anti-MDS tumors.

Integration Analysis of JAK2 or RUNX1 Mutation With Bone Marrow Blast Can Improve Risk Stratification in the Patients With Lower Risk Myelodysplastic Syndrome.

Despite the improvements in prognostication of the revised International Prognostic Scoring System (IPSS-R) in myelodysplastic syndrome (MDS), there remain a portion of patients with lower risk (low/intermediate risk, LR) but poor prognostics. This study aimed to evaluate the relative contribution of mutational status when added to the IPSS-R, for estimating overall survival (OS) and progression-free survival (PFS) in patients with LR-MDS. We retrospectively analyzed clinical and laboratory variables of 328 patients diagnosed with MDS according to the FAB criteria. Twenty-nine-gene NGS assay was applied to bone marrow samples obtained at diagnosis. 233 (71.04%) patients were classified as LR-MDS. Univariate analysis showed association between inferior outcome (OS and PFS) and presence of JAK2 (p = 0.0177, p = 0.0002), RUNX1 (p = 0.0250, p = 0.0387), and U2AF1 (p = 0.0227, p = 0.7995) mutations. Multivariable survival analysis revealed JAK2 (p < 0.0001) and RUNX1 (p = 0.0215) mutations were independently prognostic for PFS in LR-MDS. Interestingly, bone marrow blast >1.5% could further predict disease progression of patients with LR-MDS (HR 8.06, 95%CI 2.95-22.04, p < 0.0001). Incorporation of JAK2, RUNX1 mutation and bone marrow blast in the IPSS-R can improve risk stratification in patients with LR-MDS. In summary, our result provided new risk factors for LR-MDS prognostics to identify candidates for early therapeutic intervention.

The efficacy and toxicity of the CHG priming regimen (low-dose cytarabine, homoharringtonine, and G-CSF) in higher risk MDS patients relapsed or refractory to decitabine.

PURPOSE: Myelodysplastic syndromes (MDSs) refractory or relapsed after hypomethylating agents (HMAs) remain a therapeutic challenge. The CHG regimen has been demonstrated to be effective in initially treating higher risk MDS. The current study evaluated the efficacy and toxicity of the CHG regimen in patients who were resistant to decitabine. METHODS: Patients with higher risk MDS relapsed or refractory to decitabine were enrolled in this study. Each patient received the CHG regimen (cytarabine (25 mg/day, days 1-14) and homoharringtonine (1 mg/day, days 1-14) intravenously with G-CSF (300 µg/day) subcutaneously from day 0 until neutrophil count recovery to 2.0 × 109 cells/L). Next gene sequencing with a 31-gene panel was carried out in patients. RESULTS: Thirty-three patients were enrolled, including 12 relapsed and 21 refractory cases. The overall response rate (ORR) was 39.4% (13 of 33), with 9 (27.3%) achieving complete remission (CR), 2 having marrow CR (mCR), and 2 achieving partial remission (PR). The CR rate was higher in patients harboring fewer gene mutations (0-1) (55.6%) than in those with more gene mutations (> 1) (12.5%) (p = 0.021). The median overall survival (OS) of the 33 patients was 7.0 months. Patients who achieved a response had significantly longer survival times than were found in those without a response (21.0 M vs. 4.0 M, p < 0.0001). The regimen was endurable for most of the patients. CONCLUSIONS: The CHG priming regimen provided a safe and effective salvage regimen for higher risk MDS patients who were resistant to decitabine. Further studies involving larger samples will be needed. Clinical trial No. ChiCTR-ONC-11001501.

Iron overload promotes erythroid apoptosis through regulating HIF-1a/ROS signaling pathway in patients with myelodysplastic syndrome.

Erythroid apoptosis increases significantly in myelodysplastic syndrome (MDS) patients with iron overload, but the underlying mechanism is not fully clear. In this study, we aim to explore the effect of HIF-1a/ROS on erythroid apoptosis in MDS patients with iron overload. We found that iron overload injured cellular functions through up-regulating ROS levels in MDS/AML cells, including inhibited cell viability, increased cell apoptosis and blocked cell cycle at G0/G1 phase. Interestingly, overexpression of hypoxia inducible factor-1a (HIF-1a), which was under-expressed in iron overload models, reduced ROS levels and attenuated cell damage caused by iron overload in MDS/AML cells. And gene knockdown of HIF-1a got the similar results as iron overload in MDS/AML cells. Furthermore, iron overload caused high erythroid apoptosis was closely related with ROS in MDS patients. Importantly, the HIF-1a protein levels of erythrocytes elevated obviously after incubation with desferrioxamine (DFO) from MDS patients with iron overload, accompanied by ROS levels inhibited and erythroid apoptosis reduced. Taken together, our findings determine that the HIF-1a/ROS signaling pathway plays a key role in promoting erythroid apoptosis in MDS patients with iron overload.

Decitabine treatment sensitizes tumor cells to T-cell-mediated cytotoxicity in patients with myelodysplastic syndromes.

Decitabine treatment improves immunological recognition that increases expression of cancer-testis antigens (CTAs) against solid tumors. The mechanisms of decitabine enhancement of immunogenicity when used for patients with myelodysplastic syndromes (MDS) remain unclear. In the present study, we found relatively low baseline expression of MAGE-A1, MAGE-A3, and SP17 in MDS-derived cell lines. Decitabine treatment significantly improved MAGE-A1, MAGE-A3, and SP17 expression in these cell lines and in MDS patients. Decitabine-treated K562 and SKM-1 target cells with incrementally induced MAGE-A1, MAGE-A3, or SP17 levels up-regulated T lymphocyte function. Decitabine treatment improved CTA-specific cytotoxic T lymphocyte (CTL) recognition of MDS cells via the up-regulation of CTAs. This response was accompanied by enhanced T lymphocyte function and HLA class antigen expression, and increased ICAM-1. These findings suggested that decitabine may have a broad range of therapeutic applications when it is used in association with active adaptive immunity responses against up-regulated CTAs.

Exploration of the role of gene mutations in myelodysplastic syndromes through a sequencing design involving a small number of target genes.

Novel sequencing designs are necessary to supplement the recognized knowledge of myelodysplastic syndrome (MDS)-related genomic alterations. In this study, we sequenced 28 target genes in 320 Chinese MDS patients but obtained 77.2% of recall factors and 82.8% of genetic abnormalities (including karyotype abnormalities). In addition to known relationships among mutations, some specific chromosomal abnormalities were found to link to specific gene mutations. Trisomy 8 tended to be linked to U2AF1 and ZRSR2 mutations, and 20q- exhibited higher SRSF2/WT1 and U2AF1 mutation frequency. Chromosome 7 involvement accounted for up to 50% of RUNX1 mutations and 37.5% of SETBP1 mutations. Patients carrying a complex karyotype were prone to present TP53 mutations (36.1%). However, individuals with normal karyotypes rarely possessed mutations in the TP53, RUNX1 and U2AF1. Moreover, DNMT3A, TP53, SRSF2, STAG2, ROBO1/2 and WT1 predicted poor survival and high AML transformation. By integrating these predictors into international prognostic scoring system (IPSS) or revised IPSS, we built a set of mutation-based prognostic risk models. These models could layer different degrees of risk in patients more satisfactorily. In summary, this sequencing design was able to detect a number of gene mutations and could be used to stratify patients with varied prognostic risk.

Increased PD-1/STAT1 ratio may account for the survival benefit in decitabine therapy for lower risk myelodysplastic syndrome.

Decitabine is an effective therapy for patients with lower risk myelodysplastic syndrome (MDS). However, the mechanisms of decitabine's therapeutic effect are not well established. Forty-four lower risk MDS patients received decitabine therapy. 59.1% patients achieved treatment response, and 53.8% patients who were RBC/platelet-dependent cast off the transfusion burden. The median overall survival (OS) was 19.0 months after decitabine treatment. Moreover, polarization toward type 1 in the CD8 + subset was enhanced, and a significantly increased expression of the PD-1, PD-L1, and PD-1/STAT1 ratio was observed in these lower risk MDS. The patients with amplification of PD-1/STAT1 ratio (2-4) achieved longer OS. Thus, our results suggest that the effect mechanism of decitabine toward lower risk MDS may be the moderate increase of PD-1/STAT1, which contributes to hematopoietic improvement. These findings suggest that a different PD-1-related strategy from those used to treat higher risk patients could be used for lower risk MDS patients.

TP53 mutations predict decitabine-induced complete responses in patients with myelodysplastic syndromes.

To identify the molecular signatures that predict responses to decitabine (DAC), we examined baseline gene mutations (28 target genes) in 109 myelodysplastic syndrome (MDS) patients at diagnosis. We determined that TP53 mutations predicted complete response (CR), as 10 of 15 patients (66·7%) who possessed TP53 mutations achieved a CR. Univariate and multivariate analyses showed that TP53 mutations are the only molecular signatures predictive of a CR to DAC in MDS. Among the ten patients with TP53 mutations who achieved a CR, nine presented with complex karyotypes due to abnormalities involving chromosome 5 and/or chromosome 7, and eight possessed monosomies. Although TP53 mutations were associated with a higher frequency of CRs, they were not associated with improved survival. Poor outcomes were attributed to early relapses and transformation to acute myeloid leukaemia after CR. Post-DAC therapy patient gene mutation profiles showed that most CR patients exhibited fewer gene mutations after achieving a CR. It seems that suppression of these gene mutations was facilitated by DAC, resulting in a CR. In summary, TP53 mutations might predict decitabine-induced complete responses in patients with MDS. DAC-induced responses may result from partial suppression of malignant clones containing mutated TP53 genes.

High expression of the human equilibrative nucleoside transporter 1 gene predicts a good response to decitabine in patients with myelodysplastic syndrome.

BACKGROUND: Despite the efficacy of decitabine treatment in myelodysplastic syndrome (MDS), no definite predictor of response is known. In this study, we investigated whether the expression levels of human equilibrative nucleoside transporter 1 (hENT1), hENT2, deoxycytidine kinase (DCK) and cytidine deaminase (CDA) genes could predict response to decitabine in MDS. METHODS: We performed quantitative real-time PCR in marrow mononuclear cells to examine the expression of hENT1, hENT2, DCK, and CDA prior to therapy in 98 MDS patients initially treated with decitabine. Response and overall survival of patients treated with decitabine were analyzed according to gene expression levels. HENT1 knockdown was performed by shRNA in the SKM-1 cell line, and the effect of this on the demethylation ability of decitabine on long interspersed nucleotide element 1 (LINE1) was investigated. RESULTS: Patients responding to decitabine presented with significantly higher hENT1 expression levels than non-responders (p = 0.004). Overall response, complete response, and cytogenetic complete response rate in patients with high hENT1 expression (79.4, 41.3, and 43.8 %) were significantly higher than those in patients with low hENT1 expression (48.6, 20.0, and 5.9 %, respectively) (p = 0.004, 0.033, and 0.006, respectively). In higher-risk MDS, patients with high hENT1 expression showed prolonged survival compared with those with low hENT1 expression (22.0 vs 14.0 months; p = 0.027). However, the expression levels of hENT2, DCK, and CDA did not affect response rate. Knockdown of hENT1 in SKM-1 cells weakened the demethylation effect on LINE1 induced by decitabine. CONCLUSIONS: High expression of hENT1 appears to predict a good response to decitabine and a prolonged survival in higher-risk MDS patients treated with decitabine. HENT1 expression knockdown weakens the demethylation effect of decitabine.

Efficacy and toxicity of decitabine versus CHG regimen (low-dose cytarabine, homoharringtonine and granulocyte colony-stimulating factor) in patients with higher risk myelodysplastic syndrome: a retrospective study.

Decitabine and CHG regimen (low-dose cytarabine and homoharringtonine with G-CSF) have been used for treating higher risk myelodysplastic syndrome (MDS). In this study, we retrospectively compared the efficacy and toxicity of the two regimens in 132 MDS patients. Complete remission (CR) was not significantly different between the groups (27.1% with decitabine vs. 30.6% with CHG, p = 0.657). The CR rate with decitabine (58.8%) was significantly higher than that with CHG (7.7%) (p = 0.007) among the patients with poor karyotypes. Five of 23 (21.7%) patients who failed to respond to decitabine achieved CR with CHG, while one of two patients achieved CR with decitabine after failure with CHG. Overall and relapse-free survival were not different between the groups. In conclusion, both decitabine and CHG regimen are effective for higher risk MDS; there is no cross resistance between the regimens. Decitabine might be a better choice for patients with poor karyotypes.