High expression of BCAT1 sensitizes AML cells to PARP inhibitor by suppressing DNA damage response.

Previous evidence has confirmed that branched-chain aminotransferase-1 (BCAT1), a key enzyme governing branched-chain amino acid (BCAA) metabolism, has a role in cancer aggression partly by restricting αKG levels and inhibiting the activities of the αKG-dependent enzyme family. The oncogenic role of BCAT1, however, was not fully elucidated in acute myeloid leukemia (AML). In this study, we investigated the clinical significance and biological insight of BCAT1 in AML. Using q-PCR, we analyzed BCAT1 mRNAs in bone marrow samples from 332 patients with newly diagnosed AML. High BCAT1 expression independently predicts poor prognosis in patients with AML. We also established BCAT1 knockout (KO)/over-expressing (OE) AML cell lines to explore the underlying mechanisms. We found that BCAT1 affects cell proliferation and modulates cell cycle, cell apoptosis, and DNA damage/repair process. Additionally, we demonstrated that BCAT1 regulates histone methylation by reducing intracellular αKG levels in AML cells. Moreover, high expression of BCAT1 enhances the sensitivity of AML cells to the Poly (ADP-ribose) polymerase (PARP) inhibitor both in vivo and in vitro. Our study has demonstrated that BCAT1 expression can serve as a reliable predictor for AML patients, and PARP inhibitor BMN673 can be used as an effective treatment strategy for patients with high BCAT1 expression. KEY MESSAGES: High expression of BCAT1 is an independent risk factor for poor prognosis in patients with CN-AML. High BCAT1 expression in AML limits intracellular αKG levels, impairs αKG-dependent histone demethylase activity, and upregulates H3K9me3 levels. H3K9me3 inhibits ATM expression and blocks cellular DNA damage repair process. Increased sensitivity of BCAT1 high expression AML to PARP inhibitors may be used as an effective treatment strategy in AML patients.

Prognostic potential of nutritional risk screening and assessment tools in predicting survival of patients with pancreatic neoplasms: a systematic review.

BACKGROUNDS & AIMS: The nutritional evaluation of pancreatic cancer (PC) patients lacks a gold standard or scientific consensus, we aimed to summarize and systematically evaluate the prognostic value of nutritional screening and assessment tools used for PC patients. METHODS: Relevant studies were retrieved from major databases (PubMed, Embase, Web of Science, Cochrane Library) and searched from January 2010 to December 2023. We performed meta-analyses with STATA 14.0 when three or more studies used the same tool. RESULTS: This analysis included 27 articles involving 6,060 PC patients. According to a meta-analysis of these studies, poor nutritional status evaluated using five nutritional screening tools Prognostic Nutritional Index (PNI), Geriatric Nutritional Risk Index (GNRI), Controlling Nutritional Status Score (CONUT), Nutrition Risk Screening (NRS2002) and Glasgow Prognostic Score (GPS) was associated with all-cause mortality in PC patients. But Modified Glasgow Prognostic Score (mGPS) did not. Of all tools analyzed, CONUT had the maximum HR for mortality (HR = 1.978, 95%CI 1.345-2.907, P = 0.001). CONCLUSION: All-cause mortality in PC patients was predicted by poor nutritional status. CONUT may be the best nutritional assessment tool for PC patients. The clinical application value of Short Form Mini Nutritional Assessment (MNA-SF), Generated Subjective Global Assessment (SGA) and Patient-generated Subjective Global Assessment (PG-SGA) in PC patients need to be confirmed. In order to improve patients' nutritional status and promote their recovery, nutritional screening tools can be used. REGISTRATION: This systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) (number CRD42022376715).

Diagnosis of Benign and Malignant BI-RADS 4 Breast Masses by Contrastenhanced Ultrasound Combined with Shear Wave Elastography.

BACKGROUND: Breast cancer, one of the most prevalent malignant tumors in females, usually occurs in the breast epithelial tissues. OBJECTIVE: The study aimed to explore the diagnostic value of contrast-enhanced ultrasound (CEUS) combined with shear wave elastography (SWE) in the diagnosis of benign and malignant breast masses in BI-RADS (Breast Imaging Reporting and Data System) 4. METHODS: Examination outcomes and clinical information of 83 patients with BI-RADS 4 breast masses were analyzed retrospectively. These included patients who received CEUS, SWE, and pathological examinations. The difference of CEUS in determining the classification of BI-RADS 4 breast masses was evaluated using histopathological outcomes of breast masses as a reference standard. The diagnostic value of CEUS, SWE, and CEUS combined with SWE in the diagnosis of benign and malignant breast masses in BI-RADS 4 was also explored. RESULTS: Pathological biopsy results revealed 63 malignant masses and 20 benign masses among 83 BI-RADS 4 breast masses, with a 75.9% incidence of malignant masses. After the diagnosis of BI-RADS 4 breast masses with CEUS, SWE, and CEUS+SWE, the incidence of malignancy was 56.6%, 78.3%, and 73.5%, respectively. CEUS+SWE showed higher sensitivity (93.7% vs. 81% and 68.3%), specificity (90% vs. 30% and 80%), positive predictive value (96.7% vs. 78.5% and 91.5%), negative predictive value (81.8% vs. 33.3% and 44.4%), and diagnostic coincidence rate (92.8% vs. 68.7% and 71.1%) than SWE and CEUS alone in diagnosing pathological type of breast masses. Moreover, CEUS combined with SWE exhibited a larger area under the receiver operating characteristic (ROC) curve (0.918) than SWE (0.741, p = 0.028) and CEUS (0.555, p < 0.001) alone in the diagnosis of BI-RADS 4 breast masses. CONCLUSION: Overall, the diagnostic value of CEUS+SWE for the pathological type of BI-RADS is preferred over CEUS and SWE alone. CEUS+SWE showed higher values than CEUS and SWE alone in diagnosing BI-RADS 4 breast masses. Specifically, CEUS+SWE can correctly identify benign and malignant masses, reduce unnecessary trauma, and avoid misdiagnosis. In summary, CEUS combined with SWE can serve as an effective diagnostic method and avoid delaying the best treatment opportunity for some malignant lesions.

High Expression of CD300A Predicts Poor Survival in Acute Myeloid Leukemia.

INTRODUCTION: Recent studies have suggested that CD300A was an oncogene in acute myeloid leukemia (AML) development. However, the clinical relevance and biological insight into CD300A expression in AML are still not well understood. The present study aimed to examine the expression characteristics of CD300A in AML and confirmed its clinical significance for AML. METHODS: Quantification of the CD300A transcript was performed in 119 AML patients by real-time quantitative PCR in bone marrow blasts. The predictive significance of CD300A expression on the clinical outcomes of AML was assessed using overall survival (OS) and relapse-free survival (RFS). The published Cancer Genome Atlas (TCGA) data were used as an external validation for survival analysis and pathway analyses. RESULTS: In comparison with monocytes from healthy peripheral blood cells, the expression levels of CD300A in AML cells were higher. Patients in the intermediate and adverse risk categories by WHO criteria (2018) had higher CD300A expression levels than those in the favorable risk category (p < 0.001). AML patients with high expression of CD300A had a higher early death rate (p = 0.029), lower complete remission rate (p = 0.042), higher death rate (p < 0.001) and relapse rate (p = 0.002), and shorter OS (p < 0.0001) and RFS (p < 0.0001). Through multivariable analysis, high CD300A expression in AML was also an independent poor prognostic factor. The CAMP and CGMP-PKG signaling pathways may be stimulated by increased CD300A expression levels, which may be important for the development of AML. CONCLUSIONS: The expression levels of CD300A were associated with risk stratification and the clinical relevance of AML. High CD300A expression may act as an independent adverse prognostic factor for OS and RFS in AML.

Anti-PD-1 treatment-induced immediate central diabetes insipidus: a case report.

Modulating PD-1 expression can constrain tumor growth. Hodgkin's lymphoma patients commonly express PD-L1 on tumor cells. We report the case of a 60-year-old male patient with relapsed classical Hodgkin's lymphoma who suffered from immediate-onset chill, hyperthermia and polyuria following initial treatment with sintilimab, an anti-PD-1 monoclonal antibody. The results revealed central diabetes insipidus (cDI). After 3 months of treatment with glucocorticoids and desmopressin acetate, his symptoms and the results were consistent with the resolution of cDI and the treatment course was discontinued. Diabetes insipidus is a rare complication of immunotherapeutic treatment, and this is the first case report to our knowledge to have described immediate-onset cDI caused by anti-PD-1 treatment.

Lay abstract For relapsed classical Hodgkin's lymphoma, anti-PD-1 monoclonal antibodies have been related to potent safety profiles and efficacy. Reported here is a case of a 60-year-old man diagnosed as having relapsed classical Hodgkin's lymphoma. He achieved a durable response over 4 months with four rounds of traditional chemotherapy, and then the disease relapsed. Sintilimab, an anti-PD-1 monoclonal antibody, was executed for salvage therapy. In spite of the patient-acquired durable response, central diabetes insipidus was detected after the first application of sintilimab. According to our knowledge this is the first case to report immediate-onset central diabetes insipidus caused by the treatment of anti-PD-1. In the present study, we discussed and analyzed the types and clinical causes of diabetes insipidus for this patient.

miR-550-1 functions as a tumor suppressor in acute myeloid leukemia via the hippo signaling pathway.

MicroRNAs (miRNAs) and N6-methyladenosine (m6A) are known to serve as key regulators of acute myeloid leukemia (AML). Our previous microarray analysis indicated miR-550-1 was significantly downregulated in AML. The specific biological roles of miR-550-1 and its indirect interactions and regulation of m6A in AML, however, remain poorly understood. At the present study, we found that miR-550-1 was significantly down-regulated in primary AML samples from human patients, likely owing to hypermethylation of the associated CpG islands. When miR-550-1 expression was induced, it impaired AML cell proliferation both in vitro and in vivo, thus suppressing tumor development. When ectopically expressed, miR-550-1 drove the G0/1 cell cycle phase arrest, differentiation, and apoptotic death of affected cells. We confirmed mechanistically that WW-domain containing transcription regulator-1 (WWTR1) gene was a downstream target of miR-550-1. Moreover, we also identified Wilms tumor 1-associated protein (WTAP), a vital component of the m6A methyltransferase complex, as a target of miR-550-1. These data indicated that miR-550-1 might mediate a decrease in m6A levels via targeting WTAP, which led to a further reduction in WWTR1 stability. Using gain- and loss-of-function approaches, we were able to determine that miR-550-1 disrupted the proliferation and tumorigenesis of AML cells at least in part via the direct targeting of WWTR1. Taken together, our results provide direct evidence that miR-550-1 acts as a tumor suppressor in the context of AML pathogenesis, suggesting that efforts to bolster miR-550-1 expression in AML patients may thus be a viable clinical strategy to improve patient outcomes.

Apigenin and Abivertinib, a novel BTK inhibitor synergize to inhibit diffuse large B-cell lymphoma in vivo and vitro.

Background: Apigenin, a flavonoid phytochemical extracted from fruits and vegetables, has shown anti-neoplastic effects in a variety of malignant tumors. DLBCL is the most common type of aggressive lymphoma in adults with a poor prognosis. Small-molecule inhibitors like BTK inhibitors have demonstrated extended period of disease control. Whereas the effects of the synergetic inhibition of the two have not been elucidated. Methods: We assessed the efficacy of Apigenin alone or combined with Abivertinib to inhibit DLBCL progression. Cell viability was examined using the cell proliferation cell proliferation assay (MTS). Apoptotic cells and cell cycle evaluation were detected by Annexin V-FITC and DNA staining solution respectively. Western blot was used to explore the potential mechanism, and the in vivo effects of the two drugs were performed by a DLBCL xenograft BALB/c nude mice model. Results: Our results demonstrated that Apigenin can inhibit the proliferation and clone forming of DLBCL cells. Apigenin also induces apoptosis by down-regulating BCL-XL and activating Caspase family. In addition, Apigenin down-regulates cell cycle proteins including CDK2/CDK4/CDK6/CDC2/p-RB to increase G2/M phase arrest. Mechanically, our data demonstrate that Apigenin leads to a significant reduction of the expression of pro-proliferative pathway PI3K/mTOR to inhibit DLBCL cells survival. Moreover, our in vitro and in vivo results show that Apigenin can synergize with Abivertinib, a novel BTK inhibitor, in treating DLBCL visa synergistically inducing apoptosis and inhibiting the p-GS3K-ß and its downstream targets. Conclusions: Collectively, our study suggests that Apigenin exerts improving anti-lymphoma effect of BTK inhibitors and provides hope to targeted therapy of those develop resistance.

The relationship between consumption of nitrite or nitrate and risk of non-Hodgkin lymphoma.

Epidemiologic studies of the relationship between nitrite or nitrate consumption and risk of non-Hodgkin lymphoma (NHL) remain controversial. The current meta-analysis aimed to reexamine the evidence and quantitatively evaluate that relationship. Manuscripts were retrieved from the Web of Science, Chinese National Knowledge Infrastructure and PubMed databases up to May 2019. From the studies included in the review, results were combined and presented as odds ratios (OR). To conduct a dose-response (DR) analysis, studies presenting risk estimates over a series of categories of exposure were selected. Our data indicate that the consumption of nitrite was linked to a significantly increased hazard of NHL (OR: 1.37; 95% CI: 1.14-1.65), rather than nitrate (OR: 1.02; 95% CI: 0.94-1.10). According to Egger's and Begg's tests (P > 0.05), there was no evidence of significant publication bias. Moreover, our DR analysis indicated that the risk of NHL grew by 26% for each additional microgram of nitrite consumed in the diet per day (OR: 1.26; 95% CI: 1.09-1.42). Through subset analysis of the nitrite studies, data from the high-quality studies indicated that consumption was positively associated with carcinogenicity, leading to NHL (OR: 1.44; 95% CI: 1.17-1.77) and positively correlated with the development of diffuse large B-cell lymphoma (OR: 1.55; 95% CI: 1.07-2.26), but not other NHL subtypes. In addition, the data suggested that females (OR: 1.50; 95% CI: 1.15-1.95) and high levels of nitrite intake (OR: 1.64; 95% CI: 1.28-2.09) had a higher risk of NHL. Our meta-analysis supports the hypothesis that nitrite intake, but not that of nitrate, raises the risk of developing NHL. In the future, better designed prospective research studies should be conducted to confirm our findings, clarify potential biological mechanisms and instruct clinicians about NHL prophylaxis.

Homoharringtonine exhibits potent anti-tumor effect and modulates DNA epigenome in acute myeloid leukemia by targeting SP1/TET1/5hmC.

Homoharringtonine, a plant alkaloid, has been reported to suppress protein synthesis and has been approved by the US Food and Drug Administration for the treatment of chronic myeloid leukemia. Here we show that in acute myeloid leukemia (AML), homoharringtonine potently inhibits cell growth/viability and induces cell cycle arrest and apoptosis, significantly inhibits disease progression in vivo, and substantially prolongs survival of mice bearing murine or human AML. Strikingly, homoharringtonine treatment dramatically decreases global DNA 5-hydroxymethylcytosine abundance through targeting the SP1/TET1 axis, and TET1 depletion mimics homoharringtonine's therapeutic effects in AML. Our further 5hmC-seq and RNA-seq analyses, followed by a series of validation and functional studies, suggest that FLT3 is a critical down-stream target of homoharringtonine/SP1/TET1/5hmC signaling, and suppression of FLT3 and its downstream targets (e.g. MYC) contributes to the high sensitivity of FLT3-mutated AML cells to homoharringtonine. Collectively, our studies uncover a previously unappreciated DNA epigenome-related mechanism underlying the potent antileukemic effect of homoharringtonine, which involves suppression of the SP1/TET1/5hmC/FLT3/MYC signaling pathways in AML. Our work also highlights the particular promise of clinical application of homoharringtonine to treat human AML with FLT3 mutations, which accounts for more than 30% of total cases of AML.

Correction: The combination effect of homoharringtonine and ibrutinib on FLT3-ITD mutant acute myeloid leukemia.

[This corrects the article DOI: 10.18632/oncotarget.14463.].

A novel alkylating deacetylase inhibitor molecule EDO-S101 in combination with cytarabine synergistically enhances apoptosis of acute myeloid leukemia cells.

Acute myeloid leukemia (AML) is a devastating disease. Hybrid agents with dual activity, which have been shown to possess anti-cancer effect, are expected to potentially improve the prognosis of AML patients. EDO-S101 is a novel alkylating deacetylase inhibitor molecule synthesized by the addition of the hydroxamic acid of histone deacetylases inhibitor vorinostat into bendamustine, a DNA-damaging agent. However, the effect of EDO-S101 in combination with traditional chemotherapy drugs has not been studied in AML. In this study, we investigated the effect of EDO-S101 in combination with cytarabine in treating AML cells. The synergic activity against AML was identified by remarkable reduction of cell viability, significant apoptosis enhancement and the upregulation of the cleaved PARP, Casepase-3 and -7 proteins compared with monotherapy. To explain the drivers, we detected the DNA damage pathway including DNA double-strand breaks marker γ-H2AX and DNA damage checkpoint proteins, which was supposed to be responsible for the enhanced apoptosis activity. In summary, our data demonstrated that EDO-S101 in combination with cytarabine could synergistically induce the apoptosis of AML cells and it might be a potential regimen for treating leukemia.

Abivertinib, a novel BTK inhibitor: Anti-Leukemia effects and synergistic efficacy with homoharringtonine in acute myeloid leukemia.

Ibrutinib, an inhibitor of Bruton tyrosine kinase (BTK), has shown promising pharmacologic effects in acute myeloid leukemia (AML). In this study, we report that abivertinib or AC0010, a novel BTK inhibitor, inhibits cell proliferation, reduces colony-forming capacity, and induces apoptosis and cell cycle arrest in AML cells, especially those harboring FLT3-ITD mutations. Abivertinib was also found to be more sensitive than ibrutinib in treating AML. We demonstrate that in addition to targeting the phosphorylation of BTK, abivertinib also targeted the crucial PI3K survival pathway. Furthermore, abivertinib suppressed the expression of p-FLT3 and the downstream target p-STAT5 in AML cells harboring FLT3-ITD mutations. Moreover, in vitro and in vivo data revealed synergistic activity between abivertinib and homoharringtonine (HHT), a natural plant alkaloid commonly used in China, in treating AML cells with or without FLT3-ITD mutations. Collectively, these preclinical data suggest that abivertinib may be a promising novel agent for AML, with potential for combination treatment with HHT. Clinical studies on abivertinib-involved therapy are planned.

High PARP-1 expression predicts poor survival in acute myeloid leukemia and PARP-1 inhibitor and SAHA-bendamustine hybrid inhibitor combination treatment synergistically enhances anti-tumor effects.

BACKGROUND: PARP-1 plays a critical role in DNA damage repair and contributes to progression of cancer. To explore the role of PARP-1 in acute myeloid leukemia (AML), we analyzed the expression of PARP-1 in AML and its relation to the clinical prognosis. Then, we investigated the efficacy and mechanism of PARP inhibitor BMN673 (Talazoparib) combined with NL101, a novel SAHA-bendamustine hybrid in vitro and in vivo. METHODS: The expression of PARP-1 in 339 cytogenetically normal AML (CN-AML) cases was evaluated using RT-PCR. According to the expression of PARP-1, the clinical characteristics and prognosis of the patients were grouped and compared. The combination effects of BMN673 and NL101 were studied in AML cells and B-NSG mice xenograft model of MV4-11. FINDINGS: We found patients in high PARP-1 expression group had higher levels of blast cells in bone marrow (P = .003) and white blood cells (WBC) in peripheral blood (P = .008), and were associated with a more frequent FLT3-ITD mutation (28.2% vs 17.3%, P = .031). The overall survival (OS) and event free survival (EFS) of the high expression group were significantly shorter than those in the low expression group (OS, P = .005 and EFS, P = .004). BMN673 combined with NL101 had a strong synergistic effect in treating AML. The combination significantly induced cell apoptosis and arrested cell cycle in G2/M phase. Mechanistically, BMN673 and NL101 combinatorial treatment promoted DNA damage. In vivo, the combination effectively delayed the development of AML and prolonged survival. INTERPRETATION: High PARP-1 expression predicts poor survival in CN-AML patients. The synergistic effects of PARP inhibitor BMN673 in combination with SAHA-bendamustine hybrid, NL101, provide a new therapeutic strategy against AML. FUND: National Natural Science Foundation of China and Zhejiang Provincial Key Innovation Team.

High Expression of TET1 Predicts Poor Survival in Cytogenetically Normal Acute Myeloid Leukemia From Two Cohorts.

Ten-Eleven-Translocation 1 (TET1) plays a role in the DNA methylation process and gene activation. Recent reports suggest TET1 acts as an oncogene in leukemia development. However, the clinical relevance and biological insight of TET1 expression in cytogenetically normal acute myeloid leukemia (CN-AML) is unknown. In this study, quantification of TET1 transcript by real-time quantitative PCR in bone marrow blasts was performed in 360 CN-AML patients. As a result, high TET1 expression was more common in M0/M1 morphology and genes of NPM1 mutations, and underrepresented in CEBPA double allele mutations in our AML patients. In addition, we found overexpression of TET1 was associated with an inferior overall survival and event free survival in the two independent cohorts. Notably, mRNA and miRNA integrative analyses showed aberrant expression of several hub oncogenes appear to be regulated by some miRNAs like miR-127-5p, miR-494, miR-21 and miR-616 in high TET1 expressers. In conclusion, the TET1 gene expression might serve as a reliable predictor for patients survival in AML.

Promising efficacy of novel BTK inhibitor AC0010 in mantle cell lymphoma.

PURPOSE: We researched into the effect and mechanism of AC0010, a novel BTK inhibitor, in MCL, and compared its efficacy and safety with Ibrutinib to develop a preclinical study for the future therapy of MCL. METHODS: MTS assay was used to detect the growth inhibition caused by AC0010 and Ibrutinib, respectively, in MCL cell lines (Jeko-1 and JVM-2), primary MCL cells, and normal peripheral lymphocytes. Apoptosis of Jeko-1 and JVM-2 after exposure into AC0010 and Ibrutinib was conducted by flow cytometry; the expression of apoptosis-related proteins was checked by Western blot. q-PCR and Western blot were applied to examine the expression of BTK and p-BTK at mRNA and protein level as well as the BTK-ralated signaling pathways. MCL xenograft was developed to testify the efficacy and safety of AC0010 in vivo. RESULTS: In contrast with Ibrutinib, AC0010 proved to be more toxic to MCL cells in vitro (p < 0.01) with no augment in cytotoxicity to normal peripheral lymphocytes, and it can induce obvious apoptosis in MCL cell lines (p < 0.01) through caspase family and Bcl-2 family. AC0010 at 300 mg/kg can prolong the survival rate in MCL xenograft (p < 0.01). The phosphorylation of BTK is inhibited by AC0010 following simultaneously inhibition of BCR-BTK and PI3K/AKT signaling pathway in MCL cells. CONCLUSION: AC0010 is a novel BTK inhibitor of great efficacy and safety in MCL.

R-2HG Exhibits Anti-tumor Activity by Targeting FTO/m6A/MYC/CEBPA Signaling.

R-2-hydroxyglutarate (R-2HG), produced at high levels by mutant isocitrate dehydrogenase 1/2 (IDH1/2) enzymes, was reported as an oncometabolite. We show here that R-2HG also exerts a broad anti-leukemic activity in vitro and in vivo by inhibiting leukemia cell proliferation/viability and by promoting cell-cycle arrest and apoptosis. Mechanistically, R-2HG inhibits fat mass and obesity-associated protein (FTO) activity, thereby increasing global N6-methyladenosine (m6A) RNA modification in R-2HG-sensitive leukemia cells, which in turn decreases the stability of MYC/CEBPA transcripts, leading to the suppression of relevant pathways. Ectopically expressed mutant IDH1 and S-2HG recapitulate the effects of R-2HG. High levels of FTO sensitize leukemic cells to R-2HG, whereas hyperactivation of MYC signaling confers resistance that can be reversed by the inhibition of MYC signaling. R-2HG also displays anti-tumor activity in glioma. Collectively, while R-2HG accumulated in IDH1/2 mutant cancers contributes to cancer initiation, our work demonstrates anti-tumor effects of 2HG in inhibiting proliferation/survival of FTO-high cancer cells via targeting FTO/m6A/MYC/CEBPA signaling.

Publisher Correction: PP2A inhibition from LB100 therapy enhances daunorubicin cytotoxicity in secondary acute myeloid leukemia via miR-181b-1 upregulation.

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.

PP2A inhibition from LB100 therapy enhances daunorubicin cytotoxicity in secondary acute myeloid leukemia via miR-181b-1 upregulation.

Patients with secondary acute myeloid leukemia (sAML) arising from myelodysplastic syndromes have a poor prognosis marked by an increased resistance to chemotherapy. An urgent need exists for adjuvant treatments that can enhance or replace current therapeutic options. Here we show the potential of LB100, a small-molecule protein phosphatase 2 A (PP2A) inhibitor, as a monotherapy and chemosensitizing agent for sAML using an in-vitro and in-vivo approach. We demonstrate that LB100 decreases cell viability through caspase activation and G2/M cell-cycle arrest. LB100 enhances daunorubicin (DNR) cytotoxicity resulting in decreased xenograft volumes and improved overall survival. LB100 profoundly upregulates miR-181b-1, which we show directly binds to the 3' untranslated region of Bcl-2 mRNA leading to its translational inhibition. MiR-181b-1 ectopic overexpression further diminishes Bcl-2 expression leading to suppression of sAML cell growth, and enhancement of DNR cytotoxicity. Our research highlights the therapeutic potential of LB100, and provides new insights into the mechanism of LB100 chemosensitization.

Homoharringtonine targets Smad3 and TGF-ß pathway to inhibit the proliferation of acute myeloid leukemia cells.

Homoharringtonine (HHT) has long and widely been used in China for the treatment of acute myeloid leukemia (AML), the clinical therapeutic effect is significant but the working mechanism is poorly understood. The purpose of this study is to screen the possible target for HHT with virtual screening and verify the findings by cell experiments. Software including Autodock, Python, and MGL tools were used, with HHT being the ligand and proteins from PI3K-Akt pathway, Jak-stat pathway, TGF-ß pathway and NK-κB pathway as the receptors. Human AML cell lines including U937, KG-1, THP-1 were cultured and used as the experiment cell lines. MTT assay was used for proliferation detection, flowcytometry was used to detect apoptosis and cell cycle arrest upon HHT functioning, western blotting was used to detect the protein level changes, viral shRNA transfection was used to suppress the expression level of the target protein candidate, and viral mRNA transfection was used for over-expression. Virtual screening revealed that smad3 from TGF-ß pathway might be the candidate for HHT binding. In AML cell line U937 and KG-1, HHT can induce the Ser423/425 phosphorylation of smad3, and this phosphorylation can subsequently activate the TGF-ß pathway, causing cell cycle arrest at G1 phase in U937 cells and apoptosis in KG-1 cells, knockdown of smad3 can impair the sensitivity of U937 cell to HHT, and over-expression of smad3 can re-establish the sensitivity in both cell lines. We conclude that smad3 is the probable target protein of HHT and plays an important role in the functioning mechanism of HHT.

Prognostic significance of huntingtin interacting protein 1 expression on patients with acute myeloid leukemia.

Huntingtin interacting protein 1 (HIP1) is an endocytic protein which is overexpressed in a variety of human cancers and involved in cancer-causing translocation in leukemia. However, the prognostic impact of HIP1 expression on AML remains unclear. In this study, quantification of HIP1 transcript by real-time quantitative PCR in bone marrow blasts was performed in 270 AML patients. As a result, high HIP1 expression was seen more frequently in older patients, M4/M5 morphology and genes of NPM1 and DNMT3A mutations, and underrepresented in favorable karyotype subgroups and CEBPA double allele mutations in our AML patients. We also found high HIP1 expressers showed lower levels of hemoglobin. In addition, overexpression of HIP1 was associated with an inferior overall survival. The prognostic value of HIP1 expression was validated in patients from an independent TCGA cohort. Notably, up-regulation of miR-16, miR-15a, miR-28 and miR-660 were seen in high HIP1 expressers from the two independent cohorts. In vitro, interfereing of HIP1 expression by siRNA suppressed the proliferation of leukemic cells, and downregulation of these miRNAs were seen in THP-1 and Kasumi cell lines after silencing HIP1 expression. In conclusion, the HIP1 gene expression might serve as a reliable predictor for overall survival in AML patients.