FUBP3 regulates chronic myeloid leukaemia progression through PRC2 complex regulated PAK1-ERK signalling

The development of resistance and heterogeneity in differential response towards tyrosine kinase inhibitors (TKI) in chronic myeloid leukaemia (CML) treatment has led to the exploration of factors independent of the Philadelphia chromosome. Among these are the association of deletions of genes on derivative (der) 9 chromosome with adverse outcomes in CML patients. However, the functional role of genes near the breakpoint on der (9) in CML prognosis and progression remains largely unexplored. Copy number variation and mRNA expression were evaluated for five genes located near the breakpoint on der (9). Our data showed a significant association between microdeletions of the FUBP3 gene and its reduced expression with poor prognostic markers and adverse response outcomes in CML patients. Further investigation using K562 cells showed that the decrease in FUBP3 protein was associated with an increase in proliferation and survival due to activation of the MAPK-ERK pathway. We have established a novel direct interaction of FUBP3 protein and PRC2 complex in the regulation of ERK signalling via PAK1. Our findings demonstrate the role of the FUBP3 gene located on der (9) in poor response and progression in CML with the identification of additional druggable targets such as PAK1 in improving response outcomes in CML patients.

Validation of the EUTOS Long-Term Survival Score in Chinese Chronic Myeloid Leukemia Patients Treated with Imatinib: A Multicenter Real-World Study

Purpose

To validate the clinical efficacy of the recently developed EUTOS long-term survival (ELTS) score in a real-world setting.

Patients and Methods

A total of 479 chronic myeloid leukemia (CML) patients treated with frontline imatinib between January 2010 and December 2017 were enrolled in this retrospective study. The ELTS score was evaluated on the end-points including complete cytogenetic response (CCyR), progression-free survival (PFS), overall survival (OS) and CML-related death, and the efficiency of the ELTS score was further compared with the historical Sokal, Hasford, EUTOS scores.

Results

With a median follow-up of 69 months (range, 9–112 months), 462 evaluable patients were stratified into the ELTS low-risk (n = 230), ELTS intermediate-risk (n = 168) and ELTS high-risk (n = 64) groups. For the regular assessment indicators like CCyR, PFS and OS, the ELTS scoring system could effectively identify the corresponding risk groups, similarly with the results provided by previous scoring systems. With respect to the CML-related death, the ELTS score could accurately identify a high-risk group with a significantly higher risk of dying of CML, and the 5-year cumulative incidence occurred in the ELTS high-, intermediate-, and low-risk groups was 11% (95% CI: 3–19%), 5% (95% CI: 1–9%) and 2% (95% CI: 0–4%), respectively. Most notably, the ELTS score outperformed the Sokal, Hasford and EUTOS scores without statistical difference among different risk groups.

Conclusion

The ELTS score could effectively predict the prognosis of imatinib-treated CML patients in real-life settings.

Immunological monitoring of newly diagnosed CML patients treated with bosutinib or imatinib first-line

Changes in the immune system induced by tyrosine kinase inhibitors (TKI) have been shown to positively correlate with therapy responses in chronic myeloid leukemia (CML). However, only a few longitudinal studies exist and no randomized comparisons between two TKIs have been reported. Therefore, we prospectively analyzed the immune system of newly diagnosed CML patients treated with imatinib (n = 20) or bosutinib (n = 13), that participated in the randomized BFORE trial (NCT02130557). Comprehensive immunophenotyping, plasma protein profiling, and functional assays to determine activation levels of T and NK cells were performed at diagnosis, 3, and 12 months after therapy start. All results were correlated with clinical parameters such as Sokal risk and BCR-ABL load measured according to IS%. At diagnosis, low Sokal risk CML patients had a higher frequency of cytotoxic cells (CD8 + T and NK cells), increased cytotoxic potential of NK cells and lower frequency of naïve and central memory CD4 + T cells. Further, soluble plasma protein profile divided patients into two distinct clusters with different disease burden at diagnosis. During treatment, BCR-ABL IS% correlated with immunological parameters such as plasma proteins, together with different memory subsets of CD4+ and CD8 + T cells. Interestingly, the proportion and cytotoxic potential of NK cells together with several soluble proteins increased during imatinib treatment. In contrast, no major immunological changes were observed during bosutinib treatment. In conclusion, imatinib and bosutinib were shown to have differential effects on the immune system in this randomized clinical trial. Increased number and function of NK cells were especially observed during imatinib therapy.

A unique case of chronic myeloid leukemia presenting as monocular vision loss with unilateral retinopathy

Purpose

To report a case of unilateral leukemic retinopathy secondary to chronic myeloid leukemia (CML).

Observations

Patient presented to clinic with a visual acuity (VA) of 20/200 in the right eye (OD) after several months of progressive monocular vision loss and was found to have dense pre-retinal hemorrhage. Patient underwent 23-gauge pars plana vitrectomy to clear the preretinal hemorrhage along with a complex macula-off retinal detachment repair to address retinal tear and multilayer retinal hemorrhage. The patient was subsequently diagnosed with CML as she was found to be positive for the fusion protein of break point cluster gene (BCR) with Abelson tyrosine kinase (ABL1), BCR-ABL1, upon systemic work-up. Imatinib therapy resulted in complete hematologic and cytogenetic resolution after one month, however, the patient's vision remained unchanged six months after surgery.

Conclusion and importance

To the authors' knowledge, this is the first reported case of unilateral leukemic retinopathy secondary to low risk CML, as determined by the Sokal and Hasford prognostic scoring systems. CML should be included in the differential diagnosis of patients with progressive monocular vision loss with suspicious multi-layer retinal compromise.

Comparative analysis of the Sokal, Euro and European Treatment and Outcome Study score in prognostication of Indian chronic myeloid leukemia-chronic phase patients on imatinib

Introduction:

The ultimate goal for CML management is risk stratification of the patients to design the appropriate treatment approach. The Sokal, Euro and EUTOS risk scores were established to prognosticate the patients on therapy.

Aim:

To perform a comparative assessment of the Sokal, Euro and EUTOS prognostic score in Indian CML-CP patients on imatinib.

Methods:

This is a retrospective study performed in 260 Ph+ CML-CP patients who were administered oral imatinib (400 mg/day).

Results:

166/260 were males and 94/260 were females (M: F::1.6:1) with median age 35 years (range 20-70). 92 (35.38%), 125 (48.07%) and 43 (16.5%) patients were divided into low, intermediate and high risk Sokal score respectively. 102 (39.23%), 106 (40.76%) and 52 (20%) patients were discriminated into low, intermediate and high risk Euro score respectively. 210 (80.7%) and 50 (19.2%) patients were divided into low and high risk EUTOS score. Cumulative incidence of MMR for low, intermediate and high-risk Sokal score was 87%, 76% and 84% respectively (P = 0.016). Incidence of MMR in low, intermediate and high-risk Euro score was 93%, 85% and 68% respectively (P = 0.001). Incidence of MMR was 80 % and 81% for low and high risk EUTOS score (P = 0.764). Both EFS and OS are significantly correlated with Sokal score (P = 0.004, P = 0.007) and Euro score (P = 0.009, P = 0.001) but not with EUTOS score (P = 0.581, P = 0.927).

Conclusion:

The present study highlights the significant prognostic role of Sokal and Euro score in predicting the treatment outcome of the CML- CP patients on imatinib.

Predictive value of serum cytokine levels in chronic myeloid leukemia patients

Serum samples taken at diagnosis in 28 chronic myeloid leukemia patients were tested for the presence of 20 cytokines by a magnetic bead-based Bio-plex immunoassay. According to complete cytogenetic remission achieved at 12 months of treatment, patients were divided into groups with either optimal or non-optimal outcome. Patients with increased cytokine levels tended to react optimally to the therapy more frequently than those others. TGF-β3 was a notable exception; its levels were significantly higher in patients with non-optimal outcomes. Further analysis enabled us to define two combinations of cytokine cut-off levels - namely low TGF-β3 and either high IL-8 or high MCP-1-each of which corresponded to therapy outcome better than either Sokal or EUTOS scores.

Comparison of the utility and applicability of the Sokal, Hasford, and EUTOS scores in a population of Chinese patients with chronic-phase chronic myeloid leukemia undergoing imatinib therapy

BACKGROUND

Tyrosine kinase inhibitors are increasingly used to treat chronic myeloid leukemia (CML), but loss of complete cytogenetic response (CCyR) indicates treatment failure.

AIM

To compare the efficacy of Sokal, European Treatment Outcome Study (EUTOS), and Hasford prognostic scores with 3-month and 12-month CCyR, event-free survival (EFS) and progression-free survival (PFS) in patients with chronic-phase CML (CP-CML) undergoing imatinib therapy.

METHODS

We retrospectively analyzed the outcome of 210 patients with CP-CML treated at the First Affiliated Hospital of Anhui Medical University treated between January 2006 and December 2013. Sokal, EUTOS, and Hasford scores were compared with 3-month and 12-month CCyR, EFS, and PFS.

RESULTS

Kaplan-Meier analyses revealed that 3-month and 12-month CCyR and PFS were lower in patients with high EUTOS scores, and intermediate or high Sokal and Hasford scores (all P<0.05). Furthermore, EFS was lower in patients with intermediate or high Sokal and Hasford scores (both P<0.05). Hasford score (hazard ratio =2.608, 95% confidence interval: 1.473-4.617, P=0.001) was independently associated with 3-month CCyR.

CONCLUSION

Although all three scoring systems were associated with EFS, PFS, and 3-month and 12-month CCyR in the Kaplan-Meier analyses (except EFS with EUTOS), only the Hasford score was independently associated with 3m-CCyR, while EUTOS score and Sokal score were not independently associated with any of these outcomes.

Biology of CML stem cells: the basis for clinical heterogeneity?

Although chronic myeloid leukemia (CML) is now defined on the basis of the presence of the BCR-ABL1 fusion gene, which may or may not be the initial genetic event that triggers the inappropriate expansion of the myeloid cell mass, CML, similar to other leukemias, is in fact clinically heterogeneous. The biological basis for this heterogeneity is unknown. Here, we summarize some of the data illustrating this heterogeneity and speculate about possible mechanisms that may cause it. It could, for example, be intrinsic in the leukemia stem cell or could be related to some aspect of the patient's response to the leukemia.