Contributions
Abstract: EP883
Type: E-Poster Presentation
Session title: Lymphoma Biology & Translational Research
Background
Diffuse large B-cell lymphoma (DLBCL) is a clinically and genetically heterogeneous neoplasm with aggressive clinical course. The first-line treatment is chemoimmunotherapy with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone), however up to 40% of patients are refractory to treatment and have a poor clinical outcome. The available prognostic tools are not able to identify all the patients refractory to R-CHOP. Liquid biopsies, introduced with the benefit of being non-invasive, facilitate serial sampling and dynamic patients monitoring. MiRNAs, small non-coding RNAs frequently deregulated in cancer, are present in body fluids in a highly stable form, making them interesting candidates as biomarkers. In this regard, we have previously performed a pilot study on serum miRNAs profile in DLBCL patients, and found that serum miR-22-3p was significantly correlated with PFS.
Aims
In order to validate the value of circulating miR-22 as reliable non-invasive biomarker and investigate is biological function in DLBCL, we pursued the following aims: a) to analyze serum miR-22 in an independent validation cohort of DLBCL patients; b) to compare miR-22 expression in serum and matched tumor samples and c) to asses its functional role in DLBCL pathogenesis and response to R-CHOP treatment.
Methods
Multicentre prospective study on de novo DLBCL patients (n=42) uniformly treated with R-CHOP. miR-22 expression profile was evaluated by qRT-PCR in serum samples and in matched tissue samples. Survival analysis was performed by Kaplan–Meier method. miR-22 levels were further analysed by qRT-PCR in six DLBCL cell lines and related conditioned culture medium. Sensitivity to R-CHOP treatment for each cell line was evaluated determining R-CHOP IC50 by cytotoxicity MTT assays after 72h hours of treatment. HBL1 DLBCL cell line was transfected with miR-22 mimic by electroporation, 24h hours post transfection cells were plated and vital cells were counted at 24h, 48h and 72h hours.
Results
a). Our data show that patients with baseline higher serum miR-22 levels had a significant worse clinical outcome in terms of 2-year progression free survival (p = 0.015). When considering all enrolled patients (training + validation cohorts: 78 patients) serum miR-22 was differentially expressed in refractory patients compared to responders (p=0.047). b) The comparison results of miR-22 expression in serum and paired tumour samples indicate a significant and inverse correlation (Spearman’s Rho= -0.469, p=0.010). c) Assessing miR-22 expression in extracellular (conditioned medium) and intracellular fraction of DLBCL cell lines we observe that the value of extracellular to intracellular ratio of miR-22 levels is directly correlated with the cell resistance (IC50 of R-CHOP) to R-CHOP treatment (Spearman’s Rho = 0.928; value = 0.008). Moreover, a decreased proliferation rate was found upon miR-22 overexpression in HBL1 cells (a cell line with low miR-22 basal expression).
Conclusion
Altogether the results of our study suggest that miR-22 may represent a prognostic and predictive biomarker in DLBCL, and may be involved in lymphoma pathogenesis and in mechanisms of response to treatment.
Keyword(s): Diffuse large B cell lymphoma, Resistance
Abstract: EP883
Type: E-Poster Presentation
Session title: Lymphoma Biology & Translational Research
Background
Diffuse large B-cell lymphoma (DLBCL) is a clinically and genetically heterogeneous neoplasm with aggressive clinical course. The first-line treatment is chemoimmunotherapy with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone), however up to 40% of patients are refractory to treatment and have a poor clinical outcome. The available prognostic tools are not able to identify all the patients refractory to R-CHOP. Liquid biopsies, introduced with the benefit of being non-invasive, facilitate serial sampling and dynamic patients monitoring. MiRNAs, small non-coding RNAs frequently deregulated in cancer, are present in body fluids in a highly stable form, making them interesting candidates as biomarkers. In this regard, we have previously performed a pilot study on serum miRNAs profile in DLBCL patients, and found that serum miR-22-3p was significantly correlated with PFS.
Aims
In order to validate the value of circulating miR-22 as reliable non-invasive biomarker and investigate is biological function in DLBCL, we pursued the following aims: a) to analyze serum miR-22 in an independent validation cohort of DLBCL patients; b) to compare miR-22 expression in serum and matched tumor samples and c) to asses its functional role in DLBCL pathogenesis and response to R-CHOP treatment.
Methods
Multicentre prospective study on de novo DLBCL patients (n=42) uniformly treated with R-CHOP. miR-22 expression profile was evaluated by qRT-PCR in serum samples and in matched tissue samples. Survival analysis was performed by Kaplan–Meier method. miR-22 levels were further analysed by qRT-PCR in six DLBCL cell lines and related conditioned culture medium. Sensitivity to R-CHOP treatment for each cell line was evaluated determining R-CHOP IC50 by cytotoxicity MTT assays after 72h hours of treatment. HBL1 DLBCL cell line was transfected with miR-22 mimic by electroporation, 24h hours post transfection cells were plated and vital cells were counted at 24h, 48h and 72h hours.
Results
a). Our data show that patients with baseline higher serum miR-22 levels had a significant worse clinical outcome in terms of 2-year progression free survival (p = 0.015). When considering all enrolled patients (training + validation cohorts: 78 patients) serum miR-22 was differentially expressed in refractory patients compared to responders (p=0.047). b) The comparison results of miR-22 expression in serum and paired tumour samples indicate a significant and inverse correlation (Spearman’s Rho= -0.469, p=0.010). c) Assessing miR-22 expression in extracellular (conditioned medium) and intracellular fraction of DLBCL cell lines we observe that the value of extracellular to intracellular ratio of miR-22 levels is directly correlated with the cell resistance (IC50 of R-CHOP) to R-CHOP treatment (Spearman’s Rho = 0.928; value = 0.008). Moreover, a decreased proliferation rate was found upon miR-22 overexpression in HBL1 cells (a cell line with low miR-22 basal expression).
Conclusion
Altogether the results of our study suggest that miR-22 may represent a prognostic and predictive biomarker in DLBCL, and may be involved in lymphoma pathogenesis and in mechanisms of response to treatment.
Keyword(s): Diffuse large B cell lymphoma, Resistance