Effective salvage therapy for high-risk relapsed or refractory acute myeloid leukaemia with cisplatin in combination with high-dose cytarabine and etoposide

Single-cell analysis of AIMP2 splice variants informs on drug sensitivity and prognosis in hematologic cancer

Aminoacyl-tRNA synthetase-interacting multifunctional protein 2 (AIMP2) is a non-enzymatic component required for the multi-tRNA synthetase complex. While exon 2 skipping alternatively spliced variant of AIMP2 (AIMP2-DX2) compromises AIMP2 activity and is associated with carcinogenesis, its clinical potential awaits further validation. Here, we found that AIMP2-DX2/AIMP2 expression ratio is strongly correlated with major cancer signaling pathways and poor prognosis, particularly in acute myeloid leukemia (AML). Analysis of a clinical patient cohort revealed that AIMP2-DX2 positive AML patients show decreased overall survival and progression-free survival. We also developed targeted RNA-sequencing and single-molecule RNA-FISH tools to quantitatively analyze AIMP2-DX2/AIMP2 ratios at the single-cell level. By subclassifying hematologic cancer cells based on their AIMP2-DX2/AIMP2 ratios, we found that downregulating AIMP2-DX2 sensitizes cells to anticancer drugs only for a subgroup of cells while it has adverse effects on others. Collectively, our study establishes AIMP2-DX2 as a potential biomarker and a therapeutic target for hematologic cancer.

Ku, Kim et al develop a method to analyse the ratio of the alternatively spliced variant of AIMP2 to full length AIMP via single-molecule RNA-FISH. They can subclassify hematologic cancer based on AIMP2-DX2/AIMP2 ratio and find that cells with high AIMP2-DX2 ratio can be sensitized to chemotherapy drugs by depleting AIMP2-DX2.

Etoposide Combined with FLAG Salvage Therapy Is Effective in Multiple Relapsed/Refractory Acute Myeloid leukemia

Managing acute myeloid leukemia (AML) is often hampered by repeated failure to achieve complete remission as well as recurrent relapse that causes an emergent need for alternative salvage therapies. The efficacy of most salvage therapies is based on anthracycline combinations. In highly pretreated patients who are not eligible for anthracycline-based protocols therapeutic alternatives are limited. For this particular group we evaluated the efficacy and safety of fludarabine, cytarabine, granulocyte colony-stimulating factor (FLAG) in combination with etoposide (FLAG-Eto) in 36 patients. The complete remission rate (CR) was 25.7% with a median overall survival of 6 months (95% CI 4.5-7.7). The median disease-free survival for CR/CRi/MLFS (CR/CR with incomplete he-matological recovery/morphologic leukemia-free state) patients was 8 months (95% CI 0.6-15.5). The mortality rate on day 30 was 8% and increased on day 60 to 17%. Our results show meaningful anti-leukemic activity of the FLAG-Eto regimen with a moderate toxicity profile in heavily pretreated relapsed/refractory AML patients enabling consolidating allogeneic stem cell transplantation.

FLAG salvage therapy combined with idarubicin in relapsed/refractory acute myeloid leukemia

Acute myeloid leukemia (AML) is characterized by a high failure rate to achieve complete remission as well as high relapse rates that cause an emergent need for efficient and tolerable salvage therapies. The combination of FLAG with idarubicin (FLAG-Ida) is a widely used protocol. However, its efficacy has been analyzed in only a limited number of studies with majorly small patient cohorts. Here, we analyzed 132 patients with largely primary refractory or first-time relapsed AML treated according to the FLAG-Ida protocol. The overall complete remission rate (CR + CRi) was 56% with a median overall survival of 15 months (95% CI, 5.7-25.1). The median disease-free survival for CR/CRi-patients was not reached. The mortality rate on day 30 was 9% and increased on day 60 to 16%. Our results show in relapsed/refractory AML patients a high efficacy and compatibility for the FLAG-Ida regimen.

Outcomes of Six-Dose High-Dose Cytarabine as a Salvage Regimen for Patients with Relapsed/Refractory Acute Myeloid Leukemia

Relapsed/refractory acute myeloid leukemia (RR-AML) is associated with poor prognosis and long-term disease-free survival requires allogeneic hematopoietic cell transplantation (allo-HCT). Limited data exists, regarding the optimal regimen to obtain remission prior to allo-HCT. Single agent high-dose cytarabine (10-12 doses administered every 12 hours) has been previously used as induction therapy. Six-dose high-dose cytarabine (HiDAC-6), commonly used as a consolidation regimen, has never been evaluated as induction therapy. We present a retrospective review of 26 consecutive patients with RR-AML receiving single agent cytarabine 3 g/m² intravenously every 12 hours on days 1, 3, and 5 for a total of six doses (HiDAC-6). Median follow-up for surviving patients was 10.4 months (range 1.6-112.2 months). Complete remission was obtained in 62% (54% CR and 8% CRi) of the patients. The median relapse-free survival (RFS) was 22.3 months (range 0.7-112 months), event-free survival (EFS) was 4.7 months (range 0.5-112 months), and the overall survival (OS) was 9.6 months (range 1-112 months). Thirty-five percent of patients were able to subsequently proceed to allo-HCT. Treatment-related toxicities included neutropenic fever (38%), infection (35%), neurotoxicity (8%), and skin toxicity (8%). This is the first study to demonstrate HiDAC-6 as an active treatment option for younger patients with RR-AML which can effectively serve as a bridge to allo-HCT without significant toxicity.

Oridonin effectively reverses the drug resistance of cisplatin involving induction of cell apoptosis and inhibition of MMP expression in human acute myeloid leukemia cells

Cisplatin is the first generation platinum-based chemotherapy agent. However, the extensive application of cisplatin inevitably causes drug resistance, which is a major obstacle to cancer chemotherapy. Oridonin is a diterpenoid isolated from Rabdosia rubescens with potent anticancer activity. The aim of our study is to investigate the role of oridonin to reverse the cisplatin-resistance in human acute myeloid leukemia (AML) cells. The effect of oridonin on human AML cell proliferation was evaluated by MTT assay, cell migration and invasion were evaluated by transwell migration and invasion assays in cisplatin-resistant human AML cells. Furthermore, cell apoptosis was examined by flow cytometry. The inhibitive effect of oridonin in vivo was determined using xenografted nude mice. In addition, the expressions of MMP2 and MMP9 were detected by Western blot. There was a synergistic antitumor effect between cisplatin and oridonin on cisplatin-resistant human AML cells in vitro and in vivo. In addition, the combination of cisplatin and oridonin synergistically induced cell apoptosis. Furthermore, the combination treatment not only inhibited AML cell migration and invasion, but more significantly, decreased the expressions of MMP2 and MMP9 proteins. Our results suggest that the synergistic effect between both agents is likely to be driven by the inhibition of MMP expression and the resulting increased apoptosis.

Complete Remission of Acute Myeloid Leukemia following Cisplatin Based Concurrent Therapy with Radiation for Squamous Cell Laryngeal Cancer

Acute myeloid leukemia (AML) is a myeloid disorder with several established treatment regimens depending on patient and leukemic factors. Cisplatin is known to have strong leukemogenic potential and is rarely used even as salvage therapy in relapsed or refractory AML. We present a patient simultaneously diagnosed with AML and squamous cell carcinoma of the larynx, who was found to be in complete remission from AML following treatment with cisplatin based chemoradiotherapy for his laryngeal cancer.

Functional and genetic screening of acute myeloid leukemia associated with mediastinal germ cell tumor identifies MEK inhibitor as an active clinical agent

Background

Hematologic malignancies arising in the setting of established germ cell tumors have been previously described and have a dismal prognosis. Identification of targetable mutations and pathway dysregulation through massively parallel sequencing and functional assays provides new approaches to disease management.

Case Presentation

Herein, we report the case of a 23-year-old male who was diagnosed with a mediastinal germ cell tumor and subsequent acute myeloid leukemia. A shared clonal origin was demonstrated through identification of identical NRAS and TP53 somatic mutations in both malignancies. The patient’s leukemia was refractory to standard therapies with short interval relapse. Functional assays demonstrated the patient’s blasts to be sensitive to the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib, correlating with the activating NRAS mutation. The patient experienced a sustained partial remission while on trametinib therapy but ultimately suffered relapse of the germ cell tumor. The leukemic clone remained stable and sensitive to trametinib at that time.

Conclusions

This case highlights the potential power of combining genetic sequencing and in vitro functional assays with targeted therapies in the treatment of rare diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-016-0258-1) contains supplementary material, which is available to authorized users.