Good treatment-free survival of monoclonal gammopathy of undetermined significance associated pure red cell aplasia after bortezomib plus dexamethasone.

Pure red cell aplasia (PRCA) is a rare syndrome characterized by severe anemia and absence of erythroid precursors. PRCA associated to monoclonal gammopathy of undetermined significance (MGUS) is a scarce condition with less than five cases reported so far. There is no agreement on the treatment of MGUS associated PRCA and treatment- free survival (TFS) is an unmet clinical need. In this report, for the first time, we demonstrated two patients with MGUS associated PRCA obtained rapid remission and maintained TFS after accepting intensive short-term bortezomib plus dexamethasone. The first case was refractory to cyclosporine and prednisone, but achieved complete remission after ten doses of bortezomib. Moreover, he has kept TFS for 12 months. The other case initiated bortezomib plus dexamethasone as soon as making a definite diagnosis. She obtained complete remission after twelve doses of bortezomib and she has maintained a normal level of haemoglobin for 8 months.

miR-497-5p induces apoptosis in K562 cells by downregulating ROCK1.

OBJECTIVE: To validate the role of miR-497-5p in apoptosis in K562 cells by targeting Rho-associated kinase isoform 1 (ROCK1). METHODS: From January, 2017 to February, 2019, 57 patients with chronic myeloid leukemia (CML) treated in our hospital were included in patient group, and 50 healthy individuals were recruited as control group. miR-497-5p level in peripheral blood was quantitated using qRT-PCR. After transfecting with miR-497-5p overexpression vector and ROCK1 inhibitor, K562 cells were monitored in terms of proliferation (CCK8 assay), migration and invasion (Transwell), and apoptosis (flow cytometry). Binding loci between miR-497-5p and ROCK1 were predicted, and the targeting relationship was confirmed (dual-luciferase reporter (DLR) assay). RESULTS: miR-497-5p was poorly expressed in CML (P < 0.05). Forced overexpression of miR-497-5p or inhibition of ROCK1 suppressed malignant processes (proliferation, proliferation, migration and invasion) in K562 cells and induced apoptosis (P < 0.05). DLR assay revealed a decreased luciferase activity after miR-497-5p binding to ROCK1 (P < 0.05). CONCLUSION: miR-497-5p induces apoptosis in K562 cells by downregulating ROCK1.

miR-506 in patients with chronic myeloid leukemia and its effect on apoptosis of K562 cells.

OBJECTIVE: To explore the expression of miR-506 in chronic myeloid leukemia (CML) and its influence on the biological function of CML cells. METHODS: Altogether 84 CML patients from February 2012 to September 2014 were obtained as the observation group (OG), and 71 healthy people were taken as the control group (CG). miR-506 was tested using RT-qPCR, and the 5-year survival of patients with high and low expression of miR-506 was compared with the median value of miR-506 as the limit. ROC curve was applied to detect the value of miR-506 in diagnosing CML and predicting the 5-year survival of patients, and K562 cell line was transfected with miR-506 inhibitor and miR-506 mimic for observing its effects on the cell proliferation and apoptosis. RESULTS: miR-506 in CML patients was evidently lower than that in healthy people, the AUC of diagnosis of miR-506 was 0.883, the total survival of patients with low miR-506 was evidently lower than those with high miR-506, and the AUC of predicted survival of patients was 0.778. The proliferation of cells transfected with miR-506 inhibitor was promoted, the apoptosis and the survival rate reduced. CONCLUSION: miR-506 is evidently reduced in CML, and may be applied as a diagnostic and predictive treatment for CML and 5-year related survival; it can also can hinder the viability of K562 cells and promote apoptosis.