Cellular Mechanisms Underlying Complete Hematological Response of Chronic Myeloid Leukemia to BRAF and MEK1/2 Inhibition in a Patient with Concomitant Metastatic Melanoma

p19INK4d inhibits proliferation and enhances imatinib efficacy through BCR-ABL signaling pathway in chronic myeloid leukemia

Chronic myeloid leukemia (CML) is a kind of myeloproliferative disorder caused by a constitutively active BCR-ABL tyrosine kinase. Tyrosine kinase inhibitors (TKIs), imatinib and its derivatives, have achieved great progress in the treatment of CML. However, many CML patients do not respond to TKIs alone. p19^INK4d, a cyclin-dependent kinase inhibitor, plays important roles in proliferation, DNA damage repair, apoptosis and cell differentiation, but its role in CML is unknown. Herein, we found that the expression of p19^INK4d in CML patients was significantly lower than that in healthy controls. p19^INK4d overexpression inhibits cell proliferation through cell cycle arrest, and cooperates with imatinib to inhibit CML more effectively in vitro and in vivo. Mechanistically, p19^INK4d decreased the expression of BCR-ABL and its downstream molecules p-Mek1/2, moreover, the expression of Gli-1, c-myc, MUC1, Shh and TC48 also reduced significantly. Collectively, p19^INK4d inhibits proliferation and enhances imatinib efficacy in the treatment of CML. These findings maybe have implications for developing potential targets to increase imatinib sensitivity for CML.

Outcomes of Immunosuppressed Patients Who Develop Melanoma: A Population-Based Propensity-Matched Cohort Study

INTRODUCTION

Few studies have examined outcomes in immunosuppressed patients who develop melanoma. The purpose of this study is to compare survival in immunosuppressed patients who developed melanoma with that in patients with melanoma who are not immunosuppressed.

METHODS

Immunosuppressed patients were defined as having solid organ transplant, lymphoma, leukemia, or human immunodeficiency virus prior to diagnosis of melanoma. Patients with cutaneous melanoma with and without immunosuppression were identified retrospectively from the Ontario Cancer Registry (2007-2015) and linked with administrative databases to identify demographics, treatment, and outcomes. Immunosuppressed patients were matched with non-immunosuppressed patients based on age at diagnosis, sex, birth year, stage at diagnosis, and propensity score. The primary outcome was overall survival. Multivariable Cox proportional hazard regression was used to identify factors associated with survival.

RESULTS

Baseline characteristics were well balanced in 218 immunosuppressed patients matched to 436 controls. Of the patients, 186 (28.4%) were female, and median age at melanoma diagnosis was 69 (interquartile range, IQR 59-78) years. Three-year overall survival (OS) was 65% for immunosuppressed patients and 79% for non-immunosuppressed patients. Melanoma was the leading cause of death for both groups. On multivariable analysis, immunosuppression was associated with increased mortality [hazard ratio (HR) 1.70, 95% confidence interval (CI) 1.30-2.23]. Adequate treatment (HR 0.36, 95% CI 0.22-0.58) and dermatologist visits either before (HR 0.52, 95% CI 0.36-0.73) or after (HR 0.61, 95% CI 0.41-0.90) melanoma diagnosis were associated with improved OS.

CONCLUSIONS

Immunosuppressed patients who develop melanoma have worse outcomes when matched to non-immunosuppressed patients. This decrease in survival appears related to the underlying condition rather than diagnosis of melanoma.

The circular RNA of peripheral blood mononuclear cells: Hsa_circ_0005836 as a new diagnostic biomarker and therapeutic target of active pulmonary tuberculosis

It has been reported that circular RNA (circRNA) is associated with human cancer. However, few studies have been reported in active pulmonary tuberculosis (APTB). The global circRNA expression was detected in the peripheral blood mononuclear cells (PBMCs) of APTB patients (n=5) and health controls (HC) (n=5) by using high-throughput sequencing. According to the systematical bioinformatics analysis, the basic content of circRNAs and their fold changes in the two groups were calculated. We selected 6 significant differentially expressed circRNAs, hsa_circ_0005836, hsa_circ_0009128, hsa_circ_0003519, hsa_circ_0023956, hsa_circ_0078768, and hsa_circ_0088452 and validated the expression in PBMCs from APTB (n=10) and HC (n=10) by real-time quantitative reverse transcription-polymerase chain reactions (qRT-PCRs). Further, the verification of these specific circRNAs (hsa_circ_0005836 and hsa_circ_0009128) between APTB (n=34) and HC (n=30) in PBMCs was also conducted by qRT-PCRs. The RNA-seq data showed the significant differential expression of the 523 circRNAs between the APTB and HC groups (199 circRNAs were significantly up-regulated and 324 circRNAs were down-regulated). Hsa_circ_0005836 and hsa_circ_0009128 expression was significantly down-regulated in the PBMCs of APTB (P<0.05) in the samples of APTB compared to HC in our study. The gene ontology based enrichment analysis of the circRNA-miRNA-mRNAs network showed that cellular catabolic process (P=7.10E-08), regulation of metabolic process (P=2.10E-06), catalytic activity (P=3.67E-08), protein binding (P=1.71E-07), cell part (P=3.46E-06), intracellular part (P=1.71E-07), and intracellular (P=3.67E-08) were recognized in the comparisons between APTB and HC. Based on KEGG analysis, HTLV-I infection, regulation of actin cytoskeleton, neurotrophin signaling pathway and mTOR signaling pathway were relevant during tuberculosis bacillus infection. We found for the first time that hsa_circ_0005836 and hsa_circ_0009128 were significantly down-regulated in the PBMCs of APTB compared with HC. Our findings indicate hsa_circ_0005836 might serve as a novel potential biomarker for TB infection.