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. 2017 Nov 9;130(19):2073-2083.
doi: 10.1182/blood-2017-06-792150. Epub 2017 Oct 2.

Synergy of BCL2 and histone deacetylase inhibition against leukemic cells from cutaneous T-cell lymphoma patients

Benoit M Cyrenne  1 , Julia M Lewis  1 , Jason G Weed  1 , Kacie R Carlson  1 , Fatima N Mirza  1 , Francine M Foss  2 , Michael Girardi  1
Affiliations

Synergy of BCL2 and histone deacetylase inhibition against leukemic cells from cutaneous T-cell lymphoma patients

Benoit M Cyrenne et al. Blood. .

Abstract

The presence and degree of peripheral blood involvement in patients with cutaneous T-cell lymphoma (CTCL) portend a worse clinical outcome. Available systemic therapies for CTCL may variably decrease tumor burden and improve quality of life, but offer limited effects on survival; thus, novel approaches to the treatment of advanced stages of this non-Hodgkin lymphoma are clearly warranted. Mutational analyses of CTCL patient peripheral blood malignant cell samples suggested the antiapoptotic mediator B-cell lymphoma 2 (BCL2) as a potential therapeutic target. To test this, we developed a screening assay for evaluating the sensitivity of CTCL cells to targeted molecular agents, and compared a novel BCL2 inhibitor, venetoclax, alone and in combination with a histone deacetylase (HDAC) inhibitor, vorinostat or romidepsin. Peripheral blood CTCL malignant cells were isolated from 25 patients and exposed ex vivo to the 3 drugs alone and in combination, and comparisons were made to 4 CTCL cell lines (Hut78, Sez4, HH, MyLa). The majority of CTCL patient samples were sensitive to venetoclax, and BCL2 expression levels were negatively correlated (r = -0.52; P =018) to 50% inhibitory concentration values. Furthermore, this anti-BCL2 effect was markedly potentiated by concurrent HDAC inhibition with 93% of samples treated with venetoclax and vorinostat and 73% of samples treated with venetoclax and romidepsin showing synergistic effects. These data strongly suggest that concurrent BCL2 and HDAC inhibition may offer synergy in the treatment of patients with advanced CTCL. By using combination therapies and correlating response to gene expression in this way, we hope to achieve more effective and personalized treatments for CTCL.

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Figures

Figure 1.
Figure 1.
Cell line and patient samples demonstrate variable sensitivity to venetoclax. Isolated malignant cells from patient samples and 4 human-derived CTCL cell lines were incubated with a range of concentrations of venetoclax for 72 hours from which IC50s and Hill slopes were calculated. The median and mean IC50 for patient samples were 102 nM and 833 nM, respectively. (A) Patient samples in order of IC50. Patients were grouped into high responders and low responders using hierarchical cluster analysis. (B) Representative dose-response curves for patient samples (i) and CTCL cell lines (ii). (C) Comparison of Hill slopes between patient samples and cell lines. The difference between them would suggest distinct methods of actions. (D) Patient samples are most likely to be sensitive to venetoclax in more advanced disease. Stage based on ISCL classification. (E) Patient samples classified as Sézary syndrome (SS) are more likely than mycosis fungoides (MF) patients to be sensitive to venetoclax.
Figure 2.
Figure 2.
Baseline gene expression of BCL2 family members and correlation to IC50. BCL2, BCL2L1, MCL1, and BCL2L11 were measured in 20 patient samples, 4 cell lines, and 3 healthy controls. Results are expressed as a fraction of the mean of the healthy controls. (A) Baseline expression of BCL2 was found to differ significantly between high responders and low responders. No difference was found between low responders and cell lines. BCL2L1 was expressed similarly among all 4 groups. Decreased MCL1 expression was noted in cell lines compared with patient samples. (B) BCL2 mRNA expression may predict response to venetoclax in vitro, with higher expression correlating to increased sensitivity. (C) Increased ratios of expression of BCL2 to BCL2L1 predicts higher sensitivity to venetoclax.
Figure 3.
Figure 3.
Combinations of venetoclax with either romidepsin or vorinostat demonstrate synergy in patient-derived cultures. (A) Viability curves for venetoclax, vorinostat, and their combination for patient 11. After 72 hours of incubation, the viability curves and the CI were calculated using the Chou-Talalay median-effect equation. Means of the quadruplicates are shown with standard deviations. (B) Viability curves for venetoclax, romidepsin, and their combination for patient 11. (C) CI and fitted curves for the combination of venetoclax and vorinostat for patient 11. (D) CI and fitted curves for the combination of venetoclax and romidepsin for patient 11. (E) Caspase-3/7 activation after 24 hours of incubation of the cell culture derived from patient 11 with venetoclax, vorinostat, romidepsin, and their combinations. All concentrations were studied in quadruplicate and plotted are the means with their respective standard deviations. (F) A significant increase in activation of caspase is seen in higher concentration combinations. Effects are similar for combinations of venetoclax with either vorinostat and romidepsin.
Figure 4.
Figure 4.
Searching for synergy in CTCL cell lines. (A-D) Four CTCL cell lines were tested for synergy between venetoclax and vorinostat, and between venetoclax and romidepsin. Cell lines were first incubated with incremental increase of each of the 3 drugs individually to calculate IC50 values. Next, cell lines were incubated with combinations of each drug in an approximate 1:1 ratio of the calculated IC50 values. Synergy was noted between venetoclax and vorinostat in the MyLa cell line and between venetoclax and with high doses of romidepsin in the HH cell line.
Figure 5.
Figure 5.
Changes in genetic expression of BCL2 family members following incubation with vorinostat or romidepsin. (A) Significant changes include the increased expression of BCL2L11, BMF, and MCL1. Notable is the 2.7-fold increase in BCL2 expression in the MyLa cell line with vorinostat. (B) The amount of calculated synergy, represented by the CI at 0.9 fraction affected (10% viability), was correlated to change in expression of venetoclax after 24 hours of incubation with 5 µM vorinostat, a strong correlation was noted, but only limited conclusions can be drawn, due to the small sample size.
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References

    1. Girardi M, Heald PW, Wilson LD. The pathogenesis of mycosis fungoides. N Engl J Med. 2004;350(19):1978-1988. - PubMed
    1. Arulogun SO, Prince HM, Ng J, et al. . Long-term outcomes of patients with advanced-stage cutaneous T-cell lymphoma and large cell transformation. Blood. 2008;112(8):3082-3087. - PubMed
    1. Agar NS, Wedgeworth E, Crichton S, et al. . Survival outcomes and prognostic factors in mycosis fungoides/Sézary syndrome: validation of the revised International Society for Cutaneous Lymphomas/European Organisation for Research and Treatment of Cancer staging proposal. J Clin Oncol. 2010;28(31):4730-4739. - PubMed
    1. Lechowicz MJ, Lazarus HM, Carreras J, et al. . Allogeneic hematopoietic cell transplantation for mycosis fungoides and Sezary syndrome. Bone Marrow Transplant. 2014;49(11):1360-1365. - PMC - PubMed
    1. Rozati S, Cheng PF, Widmer DS, Fujii K, Levesque MP, Dummer R. Romidepsin and azacitidine synergize in their epigenetic modulatory effects to induce apoptosis in CTCL. Clin Cancer Res. 2016;22(8):2020-2031. - PubMed

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