Tumor-stroma interaction increases CD147 expression in neoplastic B lymphocytes in chronic lymphocytic leukemia.

BACKGROUND: Chronic lymphocytic leukemia (CLL) microenvironment plays a critical role in disease pathogenesis. Matrix metalloproteinases (MMPs) are involved in CLL-B cell migration and survival. CD147 is associated with MMPs production by tumor and stromal cells. AIM: To analyze CD147, MMP2 and MMP9 expression in CLL-B cells and its modulation by fibroblasts (Fb)-CLL-B cell interaction. METHODS: CLL-B cells were co-cultured with Fb, as a simulation of CLL microenvironment. CD147 was evaluated in healthy donor (HD)-B cells and CLL-B cells by flow cytometry. MMP2 and MMP9 activity in CLL-plasma samples and conditioned media (CMs) was studied by zymography. RESULTS: MMP9/MMP2 plasma levels were significantly higher in CLL patients than in HD. CD147 expression (median fluorescence intensity) in CLL patients characterized 3 groups: low- (19.1 ± 3.2; n=3), middle- (42.7 ± 12.8; n=18) and high- (76.5 ± 9.6; n=5) related to CD147 expression in HD-B cells. CD147 expression significantly increased in CLL-B cells after Fb-CLL-B cell co-culture. A significant increase in proMMP2 activity was observed in CMs obtained from Fb-CLL-B cell co-cultures in comparison with isolated CLL-B cells. CONCLUSIONS: CD147 expression in CLL-B cells and MMPs secretion was induced by Fb-CLL-B cell contact, suggesting CD147 participation in the CLL pathophysiology.

Increased Expression of Autophagy Protein LC3 in Two Patients With Progressing Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia (CLL) is the most common type of adult leukemia in the western hemisphere. It is characterized by a clonal proliferation of a population of CD5+ B lymphocytes that accumulate in the secondary lymphoid tissues, bone marrow, and blood. Some CLL patients remain free of symptoms for decades, whereas others rapidly become symptomatic or develop high-risk disease. Studying autophagy, which may modulate key protein expression and cell survival, may be important to the search for novel prognostic factors and molecules. Here, we applied flow cytometry technology to simultaneously detect autophagy protein LC3B with classical phenotypical markers used for the identification of tumoral CLL B cell clones. We found that two patients with progressing CLL showed increased expression of the autophagy protein LC3B, in addition to positive expression of CD38 and ZAP70 and unmutated status of IGHV. Our data suggest that activation of autophagy flux may correlate with CLL progression even before Ibrutinib treatment.

An analysis of multiplex-PCR in the detection of BCR-ABL transcripts in hematological disorders

In this work, we describe the advantages of multiplex-PCR in the specific detection of BCR-ABL transcripts in different hematological disorders and its sensitivity compared to nested PCR. Fifty-three patients were studied for the presence of BCR-ABL transcripts: 24 patients with chronic myeloid leukemia (CML), 20 with acute leukemia (AL), and 9 patients with other hematological disorders. A variant rearrangement (b3a3) was found in a single case of CML (4.2 percent). Four out of the 20 patients with AL (20.0 percent) (14 adults, 6 children) were bcr-abl(+), and in this group three cases were classified as B-acute lymphoblastic leukemia (B-ALL), and one as acute myeloblastic leukemia (AML). Two of the three patients with B-ALL were positive for b2a2 and the other one for e1a2, while in the BCR-ABL(+)AML patients a b3a2 rearrangement was observed. In conclusion, multiplex-PCR allows rapid, specific and simultaneous detection of different types of BCR-ABL transcripts in CML and ABL-BCR(+)AL. A full correlation was observed when multiplex-PCR was compared with nested PCR.