Primary Refractory and Relapsed Classical Hodgkin Lymphoma - Significance of Differential CD15 Expression in Hodgkin-Reed-Sternberg Cells

CD15 Is a Risk Predictor and a Novel Target in Clear Cell Renal Cell Carcinoma

INTRODUCTION

Tumor cells use adhesion molecules like CD15 or sialylCD15 (sCD15) for metastatic spreading. We analyzed the expression of CD15 and sCD15 in clear cell renal cell carcinoma (ccRCC) regarding prognosis.

METHODS

A tissue microarray containing tissue specimens of 763 patients with ccRCC was immunohistochemically stained for CD15 and sCD15, their expression quantified using digital image analysis, and the impact on patients' survival analyzed. The cell lines 769p and 786o were stimulated with CD15 or control antibody in vitro and the effects on pathways activating AP-1 and tumor cell migration were examined.

RESULTS

ccRCC showed a broad range of CD15 and sCD15 expression. A high CD15 expression was significantly associated with favorable outcome (p < 0.01) and low-grade tumor differentiation (p < 0.001), whereas sCD15 had no significant prognostic value. Tumors with synchronous distant metastasis had a significantly lower CD15 expression compared to tumors without any (p < 0.001) or with metachronous metastasis (p < 0.01). Tumor cell migration was significantly reduced after CD15 stimulation in vitro, but there were no major effects on the activating pathways of AP-1.

CONCLUSION

CD15, but not sCD15, qualifies as a biomarker for risk stratification and as an interesting novel target in ccRCC. Moreover, the data indicate a contribution of CD15 to metachronous metastasis. Further research is warranted to decipher the intracellular pathways of CD15 signaling in ccRCC in order to characterize the CD15 effects on ccRCC more precisely.

Apoptotic regulator BCL-2 blockade as a potential therapy in classical Hodgkin Lymphoma

The challenge in classical Hodgkin Lymphoma (cHL) management is the 30-40% of refractory/relapsed cases.

AIMS

The aim of this work was to determine whether NIK and BCL-2 could be useful as prognosis biomarkers in cHL. In addition, we evaluated BCL-2 as a directed-therapy in cHL cell lines using venetoclax.

MAIN METHODS

We evaluated NIK and BCL-2 expression in 112 untreated cHL patients' lymph-node biopsies by immunohistochemistry. cHL cell lines were treated with venetoclax alone or combined with vincristine or doxorubicin. Cell viability, metabolic activity and cell death were analyzed by trypan-blue exclusion method, MTS assay and FDA/IP staining respectively.

KEY FINDINGS

No correlation between NIK or BCL-2 expression and the majority of the clinical parameters was found. Patients with ≥60% BCL-2+ HRS-cells had a shorter disease-free survival (DFS) and overall survival (OS) (p = 0.002, p = 0.02 respectively). A decision tree analysis, in a 30 patients subgroup, showed that patients with <60% NIK+ HRS-cells but with ≥60% BCL-2+ HRS-cells had a worse outcome in terms of DFS and OS. These parameters performed better as prognosis indicators as compared to the diagnosis bone marrow status. Human cHL cell lines U-H01, KM-H2, L1236, SUPHD1, L540 showed sensitivity to venetoclax. The co-treatment effect of venetoclax and vincristine or doxorubicin on cell viability was diverse depending on the cell line evaluated.

SIGNIFICANCE

BCL-2 should be considered as a prognosis biomarker as well as a potential new therapeutic target in cHL. We report for the first time the cytotoxic effect of venetoclax in human cHL cell lines.

Prognostic value of Bcl2 and p53 in Hodgkin lymphoma: A systematic review and meta-analysis

AIMS

Several studies suggested that high expression of Bcl2 and/or p53 in Hodgkin/Reed-Sternberg cells is an unfavorable prognostic factor in Hodgkin lymphoma (HL). However, results in this field appear contrasting. We aimed to assess the prognostic value of p53 and Bcl2 in HL through a systematic review and meta-analysis.

METHODS

Electronic databases were searched from January 2000 to December 2020 for all studies assessing the prognostic value of p53 and Bcl2 in HL. The association of high p53 or Bcl2 expression with overall survival (OS), progression-free survival (PFS) and response to treatment was assessed by using hazard ratio (HR) and odds ratio (OR).

RESULTS

Eighteen studies were included. Bcl2 overexpression was significantly associated with decreased PFS (HR = 2.202; p < 0.0001), while the associations with decreased OS (HR = 1.565; p = 0.257) and refractoriness to treatment (OR = 0.482; p = 0.068) were non-significant. p53 overexpression was not significantly associated with refractoriness to treatment (OR = 0.904; p = 0.155); the analysis of OS and PFS was not feasible, but published data suggested the absence of a significant association.

CONCLUSIONS

In HL, Bcl2 overexpression is associated with decreased PFS, while a significant prognostic value could not be demonstrated for p53. Defining optimal criteria for interpreting Bcl2 and p53 immunostaining is necessary to draw definitive conclusions.

Hodgkin lymphoma cell lines bind to platelets. Incubation with platelets induces CD15 and P-selectin dependent adhesion of the cell lines to Human Umbilical Vein Endothelial cells (HUVEC)

Hodgkin's lymphoma is believed to spread in an orderly fashion within the lymphatic compartment. In a minority of cases, after reaching the spleen, the neoplasm disseminates, reminiscent of metastasis. In the spleen, the Hodgkin-Reed-Sternberg tumor cells come across platelets in the blood vessels and mainly in the splenic red pulp. Based on this knowledge, we investigated the possibility of platelets inducing cell adhesion in Hodgkin's lymphoma cell lines. We showed that L428 and KMH-2 cells strongly adhere to thrombin-activated platelets. Cell adhesion to platelets is partially dependent on CD15 antigens (Lewis(X)), mainly sialyl-CD15, and P-selectin. KMH-2, as compared to L428 cells, showed increased binding due to its differential high expression of the sialyl-CD15. As a consequence of incubation with platelets, KMH-2 cells also produced increased amounts of tumor necrosis factors α (TNFα) followed by enhanced binding to human vascular endothelial cells (HUVEC). Incubation of both cell lines with activated platelets also induced activation of AP-1 transcription complex. Our findings are consistent with the concept that platelets play a critical role in the dissemination of HRS cells in HL, predominantly in the spleen, by increasing cell adhesion and thus promoting their proliferative and migratory properties beyond the lymphatic system.

CD20 Over-Expression in Hodgkin-Reed-Sternberg Cells of Classical Hodgkin Lymphoma: the Neglected Quest

We have scrutinized a previously analyzed cohort of classical Hodgkin lymphoma patients for evidence of a CD20 over-expression. This was pursued in order to determine whether all the 24 (12.6%) CD20+++ patients had clinical and/or biological profiles which would warrant a separate consideration and treatment or would carry a different outcome from our 166 CD20 (-) classical Hodgkin lymphoma patients. Except for an older age and a significantly lower expression of non-sialyl-CD15 antigen, both previously described in classical Hodgkin lymphoma, no justification to exclude these CD20+++ patients from the cohort at large is apparent. We suggest that the generally accepted view to the contrary be revised. In addition, we propose alternative interpretations for the low expression of CD20 found in a majority of Hodgkin-Reed-Sternberg cells in classical Hodgkin lymphoma.