Predictive factors for successful imatinib cessation in chronic myeloid leukemia patients treated with imatinib.

Although recent studies have suggested that cessation of imatinib (IM) in chronic myeloid leukemia patients can be associated with sustained response, further validation is needed to explore predictive factors. In a prospective, multicenter study, chronic phase patients were eligible for cessation of IM therapy after more than 3 years if they had no detectable BCR-ABL1 transcript for at least 2 years. A total of 48 patients with a median age of 47 years (19-74 years) were enrolled. Twenty patients received IM for post-transplant relapse. After a median follow-up of 15.8 months (1.4-28.2 months) after IM discontinuation, nine of the non-transplant group lost undetectable molecular residual disease (UMRD) and major molecular response (MMR), whereas none of the 20 patients in the transplant group experienced UMRD loss. Probabilities for sustained MMR and UMRD were 64.4% and 66.3% in the non-transplant group, respectively. Of nine patients re-treated with IM, eight patients re-achieved MMR at a median of 1.7 months (0.9-2.8 months). Seven of these patients re-achieved UMRD at a median of 5.6 months (2.8-12.1 months). Previous transplantation, IM duration, and UMRD duration were significantly associated with sustained molecular responses. Our data strongly suggest that immunological control contributes to sustained suppression of residual leukemia cell expansion and that IM can be safely discontinued in patients with post-transplant relapse.

Effects of a transformative learning theory based debriefing in simulation: A randomized trial.

Debriefing, based on reflection, is imperative in simulation. Mezirow's transformative learning theory (TLT) uses critical reflection in providing care to patients, which involves clinical judgment in nursing. The aim of this study was to compare the effects of TLT-versus a non-TLT-based debriefing protocol on knowledge, problem-solving process, critical thinking disposition, and clinical judgment in nursing students. A randomized controlled trial was performed. Fifty-six junior nursing students were assigned to the TLT (n = 26) and the control (n = 30) groups in South Korea. Debriefing protocols based on Mezirow's TLT for the experimental group and gather-analyze-summarize-based debriefing for the control group were used for four weeks. Scores of the TLT group were significantly higher than those of the control group in the problem-solving process, critical thinking disposition, and clinical judgment of reflection. We identified the main effects of group, time, and time-by-group interaction for clinical judgment (noticing, interpreting, and responding), except for knowledge between the two groups. The TLT debriefing approach in simulation can be tailored to improve problem-solving, critical thinking, and clinical judgment outcomes, which are vital to nursing education related to the provision of care to patients.

High-Content Analysis-Based Sensitivity Prediction and Novel Therapeutics Screening for c-Met-Addicted Glioblastoma.

(1) Background: Recent advances in precision oncology research rely on indicating specific genetic alterations associated with treatment sensitivity. Developing ex vivo systems to identify cancer patients who will respond to a specific drug remains important. (2) Methods: cells from 12 patients with glioblastoma were isolated, cultured, and subjected to high-content screening. Multi-parameter analyses assessed the c-Met level, cell viability, apoptosis, cell motility, and migration. A drug repurposing screen and large-scale drug sensitivity screening data across 59 cancer cell lines and patient-derived cells were obtained from 125 glioblastoma samples. (3) Results: High-content analysis of patient-derived cells provided robust and accurate drug responses to c-Met-targeted agents. Only the cells of one glioblastoma patient (PDC6) showed elevated c-Met level and high susceptibility to the c-Met inhibitors. Multi-parameter image analysis also reflected a decreased c-Met expression and reduced cell growth and motility by a c-Met-targeting antibody. In addition, a drug repurposing screen identified Abemaciclib as a distinct CDK4/6 inhibitor with a potent c-Met-inhibitory function. Consistent with this, we present large-scale drug sensitivity screening data showing that the Abemaciclib response correlates with the response to c-Met inhibitors. (4) Conclusions: Our study provides a new insight into high-content screening platforms supporting drug sensitivity prediction and novel therapeutics screening.

The Protein Neddylation Inhibitor MLN4924 Suppresses Patient-Derived Glioblastoma Cells via Inhibition of ERK and AKT Signaling.

Glioblastoma is a highly aggressive and lethal brain tumor, with limited treatment options. Abnormal activation of the neddylation pathway is observed in glioblastoma, and the NEDD8-activating enzyme (NAE) inhibitor, MLN4924, was previously shown to be effective in glioblastoma cell line models. However, its effect has not been tested in patient-derived glioblastoma stem cells. We first analyzed public data to determine whether NEDD8 pathway proteins are important in glioblastoma development and patient survival. NAE1 and UBA3 levels increased in glioblastoma patients; high NEDD8 levels were associated with poor clinical outcomes. Immunohistochemistry results also supported this result. The effects of MLN4924 were evaluated in 4 glioblastoma cell lines and 15 patient-derived glioblastoma stem cells using high content analysis. Glioblastoma cell lines and patient-derived stem cells were highly susceptible to MLN4924, while normal human astrocytes were resistant. In addition, there were various responses in 15 patient-derived glioblastoma stem cells upon MLN4924 treatment. Genomic analyses indicated that MLN4924 sensitive cells exhibited enrichment of Extracellular Signal Regulated Kinase (ERK) and Protein kinase B (AKT, also known as PKB) signaling. We verified that MLN4924 inhibits ERK and AKT phosphorylation in MLN4924 sensitive cells. Our findings suggest that patient-derived glioblastoma stem cells in the context of ERK and AKT activation are sensitive and highly regulated by neddylation inhibition.

Potent effect of the MDM2 inhibitor AMG232 on suppression of glioblastoma stem cells.

Testing new ways to identify untapped opportunities for glioblastoma therapies remains highly significant. Amplification and overexpression of MDM2 gene is frequent in glioblastoma and disrupting the MDM2-p53 interaction is a promising strategy to treat the cancer. RG7112 is the first-in class inhibitor and recently discovered AMG232 is the most potent MDM2 inhibitor known to date. Here, we compared the effects of these two clinical MDM2 inhibitors in six glioblastoma cell lines and ten patient-derived glioblastoma stem cells. Targeted sequencing of the TP53, MDM2 genes and whole transcriptome analysis were conducted to verify genetic status associated with sensitivity and resistance to the drugs. Although TP53 wild-type glioblastoma cell lines are similarly sensitive to AMG232 and RG7112, we found that four TP53 wild-type out of ten patient-derived glioblastoma cells are much more sensitive to AMG232 than RG7112 (average IC50 of 76 nM vs. 720 nM). Among these, 464T stem cells containing MDM2 gene amplification were most sensitive to AMG232 with IC50 of 5.3 nM. Moreover, AMG232 exhibited higher selectivity against p53 wild-type cells over p53 mutant stem cells compared to RG7112 (average selectivity of 512-fold vs. 16.5-fold). Importantly, we also found that AMG232 is highly efficacious in three-dimensional (3D) tumor spheroids growth and effectively inhibits the stemness-related factors, Nestin and ZEB1. Our data provide new evidence that glioblastoma stem cells have high susceptibility to AMG232 suggesting the potential clinical implications of MDM2 inhibition for glioblastoma treatment. These will facilitate additional preclinical and clinical studies evaluating MDM2 inhibitors in glioblastoma and direct further efforts towards developing better MDM2-targeted therapeutics.

Reversible Pulmonary Arterial Hypertension Associated with Dasatinib for Chronic Myeloid Leukemia.

We describe two cases of pulmonary arterial hypertension (PAH) that occurred under dasatinib treatment and were resolved after dasatinib discontinuation. Two patients with chronic phase chronic myeloid leukemia (CML) were switched to dasatinib therapy because of hematological progress while receiving imatinib. These patients had New York Heart Association (NYHA) functional class II dyspnea with elevated right ventricular systolic pressure (RVSP), which progressed under dasatinib treatment. After dasatinib treatment was discontinued, subjective symptoms were improved to NYHA functional class I and the follow-up transthoracic Doppler echocardiography showed improved RVSP. Treatment with an alternate tyrosine kinase inhibitor was initiated and had been continued without development of dyspnea or elevation of RVSP. This report suggests that dasatinib can cause the reversible PAH, therefore, routine cardiopulmonary evaluation before and during treatment with dasatinib may be needed in CML patients with clinical manifestations.

Distinct predictive factors influence on achievement of early molecular response by frontline imatinib in chronic phase chronic myeloid leukemia.

To explore the factors for achieving early molecular responses (EMR; BCR-ABL1 ≤10% at 3 months, ≤1% at 6 months) by imatinib (IM), baseline characteristics including individual BCR-ABL1 transcript level, dose intensity, and IM trough level on day 29 were analyzed in 286 chronic phase chronic myeloid leukemia patients. Distinct predictive factors for achieving EMR at 3 months and 6 months were noted. Blast count at diagnosis and IM trough level on day 29 were significantly associated with an achievement of 3-month EMR. Early decline of BCR-ABL1 transcript, low Sokal risk, and mean daily dose (≥350mg/day) by 6 months were associated with an achievement of 6-month EMR. Understanding the predictive factors for EMR may provide additional information to guide clinical decisions on the changing therapies at each landmark.

Prognostic factors for outcomes of allogeneic stem cell transplantation in chronic phase chronic myeloid leukemia in the era of tyrosine kinase inhibitors.

The aim of this study was to estimate the prognostic factors for the outcomes of chronic myeloid leukemia (CML) patients receiving allogeneic stem cell transplantation (SCT) in chronic phase (CP) in the era of tyrosine kinase inhibitors (TKIs). Ninety-seven patients who underwent allogeneic SCT in CP were analyzed. Forty-seven were TKI-naïve at the time of transplant, and 50 received TKI(s) treatment before transplantation. After a median follow-up of 115.8 months, the 4-year overall survival and event-free survival were 80.4 and 58.8%, respectively. Multivariate analysis showed that there were no differences in survival outcomes based on prior TKI therapy. Older age was a prognostic factor for higher treatment-related mortality (TRM), and the type of graft source and younger age were associated with relapse, but prior TKI therapy and disease status at the time of transplant were not associated with either TRM or relapse. Additionally, a major molecular response at 1 month and an MR(4.5) at 3 months were important predictors of favorable long-term outcomes. This study demonstrates the prognostic factors for the outcomes of allogeneic SCT in CP CML and shows that survival outcomes were not affected by the administration of long-term multi-TKI treatment prior to transplantation.

The long-term clinical implications of clonal chromosomal abnormalities in newly diagnosed chronic phase chronic myeloid leukemia patients treated with imatinib mesylate.

The aim of this study was to evaluate the long-term clinical significance of an additional chromosomal abnormality (ACA), variant Philadelphia chromosome (vPh) at diagnosis, and newly developed other chromosomal abnormalities (OCA) in patients with chronic myeloid leukemia (CML) on imatinib (IM) therapy. Sequential cytogenetic data from 281 consecutive new chronic phase CML patients were analyzed. With a median follow-up of 78.6 months, the 22 patients with vPh (P = 0.034) or ACA (P = 0.034) at diagnosis had more events of IM failure than did the patients with a standard Ph. The 5-year overall survival (OS), event-free survival (EFS), and failure-free survival (FFS) rates for patients with vPh at diagnosis were 77.8%, 75.0%, and 53.3%, respectively; for patients with ACA at diagnosis, 100%, 66.3%, and 52.1%, respectively; and for patients with a standard Ph, 96.0%, 91.3%, and 83.7%, respectively. During IM therapy, eight patients developed an OCA, which had no impact on outcomes as a time-dependent covariate in our Cox proportional hazards regression models. This study showed that vPh was associated with poor OS and FFS and that ACA had adverse effects on EFS and FFS. In addition, no OCA, except monosomy 7, had any prognostic impact, suggesting that the development of OCA may not require a change in treatment strategy.

c-Myc stimulates cell invasion by inhibiting FBX8 function.

c-Myc is a cellular onco-protein and a transcriptional activator important for cell growth, cell division, and tumorigenesis. Despite all that is known of its function, the mechanism of how c-Myc contributes to tumorigenesis is unclear. To gain insight into the mechanism through which c-Myc protein exerts its oncogenic activity, we performed large-scale, tandem repeat affinity purification and identified the F box only protein 8 (FBX8), an F-box- and Sec7 domain-containing protein, as a novel Myc-binding protein. The c-Myc/FBX8 interaction was mediated by the c-Myc box II (MBII) region. We also confirmed that Myc protein overexpression in 293T cells affected FBX8 cellular translocation and led to recovery from FBX8-mediated inhibition of ADP-ribosylation factor 6 (ARF6) function during cell invasion. Together, these results suggest that FBX8 is a novel c-Myc binding protein and that c-Myc induces cell invasive activity through the inhibition of FBX8 effects on ARF6 function during cell invasion.

Microcatheter placement through a side hole created in a 5-F catheter into proximal subclavian arterial branches causing hemoptysis.

Five patients with moderate to massive hemoptysis who had a bronchial artery of anomalous origin or a nonbronchial systemic artery originating from the proximal subclavian artery underwent microcatheter placement through a created side hole of a 5-F catheter. All patients had pulmonary tuberculosis and had undergone bronchial artery embolization for hemoptysis. The side holes were made in the lesser (n = 2) or greater curvature sides (n = 3) of 5-F nonbraided Headhunter catheters. A microcatheter was passed through the side hole of the 5-F catheter into the target artery for embolization. Polyvinyl alcohol particles were used as the embolic material. The technical success rate was 100%, and immediate control of hemoptysis was achieved in all patients without complication.