Many efforts have been made to standardize the interpretation of 18 f-fDG pet/ct in multiple myeloma (MM) with qualitative visual analysis or with quantitative metabolic parameters using various methods for lesion segmentation of PET images. The aim of this study was to propose a quantitative method for bone and bone marrow evaluation of 18 F-FDG PET/CT considering the extent and intensity of bone 18 F-FDG uptake: Intensity of Bone Involvement (IBI). Whole body 18 F-FDG PET/CT of 59 consecutive MM patients were evaluated. Compact bone tissue was segmented in PET images using a global threshold for HU of the registered CT image. A whole skeleton mask was created and the percentage of its volume with 18 F-FDG uptake above hepatic uptake was calculated (Percentage of Bone Involvement -PBI). IBI was defined by multiplying PBI by mean SUV above hepatic uptake. IBI was compared with visual analysis performed by two experienced nuclear medicine physicians. IBI calculation was feasible in all images (range:0.00-1.35). Visual analysis categorized PET exams into three groups (negative/ mild, moderate and marked bone involvement), that had different ranges of IBI (multi comparison analysis, p < 0.0001). There was an inverse correlation between the patients' hemoglobin values and IBI (r = −0.248;p = 0.02). IBI score is an objective measure of bone and bone marrow involvement in MM, allowing the categorization of patients in different degrees of aggressiveness of the bone disease. The next step is to validate IBI in a larger group of patients, before and after treatment and in a multicentre setting.Lytic bone lesions are reported in approximately 80% of myeloma multiple (MM) patients 1,2 . Early and precise evaluation of bone involvement is crucial for staging and correct disease management.Hybrid image of positron emission tomography with 18 F-fluordeoxyglucose and computed tomography ( 18 F-FDG PET/CT) is one of the main methods for the evaluation of MM patients. It allows whole-body images, intra and extramedullary lesion detection, distinction between active lesions and scar or necrotic tissue and has been more sensitive than MRI in treatment assessment 3-5 .Many efforts have been attempted to standardize the interpretation of 18 F-FDG PET/CT in MM, using qualitative visual analysis or quantitative metabolic parameters, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG) 6-9 . However, none of these methods have been extensively used in clinical practice or research projects, probably because of the complexity of the visual quantification 6,7 or due to the lack of standardization of MTV and TLG calculations 8-10 . Also, MTV and TLG only consider areas visually defined as lesions and ignore diffuse uptake of the bone marrow.

New drug development for neoplasm treatment is nowadays based on molecular targets that participate in the disease pathogenesis and tumor phenotype. Herein, we describe a new specific pharmacological hematopoietic cell kinase (HCK) inhibitor (iHCK-37) that was able to reduce PI3K/AKT and MAPK/ERK pathways activation after erythropoietin induction in cells with high HCK expression: iHCK-37 treatment increased leukemic cells death and, very importantly, did not affect normal hematopoietic stem cells. We also present evidence that HCK, one of Src kinase family (SFK) member, regulates early-stage erythroid cell differentiation by acting as an upstream target of a frequently deregulated pathway in hematologic neoplasms, PI3K/AKT and MAPK/ERK. Notably, HCK levels were highly increased in stem cells from patients with some diseases, as Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML), that are associated with ineffective erythropoiesis These discoveries support the exploration of the new pharmacological iHCK-37 in future preclinical and clinical studies.

Myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell-based disorders characterized by ineffective hematopoiesis, increased genomic instability and a tendency to progress toward acute myeloid leukemia (AML). MDS and AML cells present genetic and epigenetic abnormalities and, due to the heterogeneity of these molecular alterations, the current treatment options remain unsatisfactory. Hypomethylating agents (HMA), especially azacitidine, are the mainstay of treatment for high-risk MDS patients and HMA are used in treating elderly AML. The aim of this study was to investigate the potential role of the epigenetic reader bromodomain-containing protein-4 (BRD4) in MDS and AML patients. We identified the upregulation of the short variant BRD4 in MDS and AML patients, which was associated with a worse outcome of MDS. Furthermore, the inhibition of BRD4 in vitro with JQ1 or shRNA induced leukemia cell apoptosis, especially when combined to azacitidine, and triggered the activation of the DNA damage response pathway. JQ1 and AZD6738 (a specific ATR inhibitor) also synergized to induce apoptosis in leukemia cells. Our results indicate that the BRD4-dependent transcriptional program is a defective pathway in MDS and AML pathogenesis and its inhibition induces apoptosis of leukemia cells, which is enhanced in combination with HMA or an ATR inhibitor.

Type 2 diabetes mellitus and cancer are correlated with changes in insulin signaling, a pathway that is frequently upregulated in neoplastic tissue but impaired in tissues that are classically targeted by insulin in type 2 diabetes mellitus. Many antidiabetes treatments, particularly metformin, enhance insulin signaling, but this pathway can be inhibited by specific cancer treatments. The modulation of cancer growth by metformin and of insulin sensitivity by anticancer drugs is so common that this phenomenon is being studied in hundreds of clinical trials on cancer.Many meta-analyses have consistently shown a moderate but direct effect of body mass index on the incidence of multiple myeloma and lymphoma and the elevated risk of leukemia in adults. Moreover, new epidemiological and preclinical studies indicate metformin as a therapeutic agent in patients with leukemia, lymphomas, and multiple myeloma. In this article, we review current findings on the anticancer activities of metformin and the underlying mechanisms from preclinical and ongoing studies in hematologic malignancies.

Vasodilator-stimulated phosphoprotein (VASP) and Zyxin are interacting proteins involved in cellular adhesion and motility. PKA phosphorylates VASP at serine 157, regulating VASP cellular functions. VASP interacts with ABL and is a substrate of the BCR-ABL oncoprotein. The presence of BCR-ABL protein drives oncogenesis in patients with chronic myeloid leukemia (CML) due to a constitutive activation of tyrosine kinase activity. However, the function of VASP and Zyxin in BCR-ABL pathway and the role of VASP in CML cells remain unknown. In vitro experiments using K562 cells showed the involvement of VASP in BCR-ABL signaling. VASP and Zyxin inhibition decreased the expression of anti-apoptotic proteins, BCL2 and BCL-XL. Imatinib induced an increase in phosphorylation at Ser157 of VASP and decreased VASP and BCR-ABL interaction. VASP did not interact with Zyxin in K562 cells; however, after Imatinib treatment, this interaction was restored. Corroborating our data, we demonstrated the absence of phosphorylation at Ser157 in VASP in the bone marrow of CML patients, in contrast to healthy donors. Phosphorylation of VASP on Ser157 was restored in Imatinib responsive patients though not in the resistant patients. Therefore, we herein identified a possible role of VASP in CML pathogenesis, through the regulation of BCR-ABL effector proteins or the absence of phosphorylation at Ser157 in VASP.