Update on histone deacetylase inhibitors in peripheral T-cell lymphoma (PTCL)

Low-dose treatment with Epirubicin, a novel histone deacetylase 1 inhibitor, exerts anti-leukemic effects by inducing ferroptosis

AIMS

Leukemia is hematopoietic stem cell malignant tumor with poor outcomes. Histone deacetylase 1 (HDAC1) is highly expressed in leukemia and current HDAC1 inhibitors have clinical limitations in leukemia therapy. Therefore, novel HDAC1 inhibitor is imperative to being found and its mechanism needs to be further explored.

MATERIALS AND METHODS

Novel HDAC1 inhibitors were discovered through drug virtual screening. CCK-8, EdU and soft agar assay were used to assess the anti-leukemic effect of the candidate HDAC1 inhibitor. ROS, lipid peroxidation, intracellular Fe2+ and LIP assay were employed to verify cell ferroptosis. Additionally, a xenograft model was performed to explore the efficacy and safety of the candidate HDAC1 inhibitor in vivo.

RESULTS

HDAC1 might be a promising therapeutic target for leukemia and Epirubicin (Epi) could be used as a potential HDAC1 inhibitor. Low-dose Epi exhibited good anti-leukemic effects by inhibiting cell proliferation, DNA synthesis and colony formation. Low-dose Epi could induce ferroptosis by triggering lipid peroxidation, which was better than that treated with current HDAC1 inhibitors Chidamide or Vorinostat, ROS generation and Fe2+ overload in leukemia cells. Mechanistically, low-dose Epi induced ferroptosis by targeting amino acid metabolism and iron metabolism. Similar results were found in a xenograft model in NOG mice with a good safety profile.

CONCLUSION

Our study demonstrated that Epi might be used as a HDAC1 inhibitor. Low-dose Epi could inhibit tumor progression by inducing cell ferroptosis in vitro and in vivo. Thus, Epi administration with lower concentration may be much more favorable and safer in the treatment with leukemia.

Lack of SMARCB1 expression characterizes a subset of human and murine peripheral T-cell lymphomas

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is a heterogeneous group of malignancies with poor outcome. Here, we identify a subgroup, PTCL-NOSSMARCB1-, which is characterized by the lack of the SMARCB1 protein and occurs more frequently in young patients. Human and murine PTCL-NOSSMARCB1- show similar DNA methylation profiles, with hypermethylation of T-cell-related genes and hypomethylation of genes involved in myeloid development. Single-cell analyses of human and murine tumors revealed a rich and complex network of interactions between tumor cells and an immunosuppressive and exhausted tumor microenvironment (TME). In a drug screen, we identified histone deacetylase inhibitors (HDACi) as a class of drugs effective against PTCL-NOSSmarcb1-. In vivo treatment of mouse tumors with SAHA, a pan-HDACi, triggered remodeling of the TME, promoting replenishment of lymphoid compartments and reversal of the exhaustion phenotype. These results provide a rationale for further exploration of HDACi combination therapies targeting PTCL-NOSSMARCB1- within the TME.

Histone Deacetylase Inhibitors for Peripheral T-Cell Lymphomas

Histone deacetylase inhibitors (HDACis) are being recognized as a potentially effective treatment approach for peripheral T-cell lymphomas (PTCLs), a heterogeneous group of aggressive malignancies with an unfavorable prognosis. Recent evidence has shown that HDACis are effective in treating PTCL, especially in cases where the disease has relapsed or is resistant to conventional treatments. Several clinical trials have demonstrated that HDACis, such as romidepsin and belinostat, can elicit long-lasting positive outcomes in individuals with PTCLs, either when used alone or in conjunction with conventional chemotherapy. They exert their anti-tumor effects by regulating gene expression through the inhibition of histone deacetylases, which leads to cell cycle arrest, induction of programmed cell death, and,the transformation of cancerous T cells, as demonstrated by gene expression profile studies. Importantly, besides clinical trials, real-world evidence indicated that the utilization of HDACis presents a significant and beneficial treatment choice for PTCLs. However, although HDACis showed potential effectiveness, they could not cure most patients. Therefore, new combinations with conventional drugs as well as new targeted agents are under investigation.

Clinical trial: Chidamide plus CHOP improve the survival of newly diagnosed angioimmunoblastic T-cell lymphoma

Background

Angioimmunoblastic T-cell lymphoma (AITL) is known for its unfavorable survival prognosis. Chidamide has shown efficacy in relapsed/refractory AITL, but its efficacy in newly diagnosed AITL is uncertain.

Objective

This retrospective research aimed to evaluate the effectiveness and safety of chidamide when used with doxorubicin, cyclophosphamide, prednisone, and vincristine (CHOP) in comparison to CHOP by itself for individuals newly diagnosed with AITL, and to examine the impact of transplantation.

Method

This was an analysis that compared outcomes among patients who received chidamide + CHOP on a clinical trial vs. historical controls who received CHOP alone, enrolling a total of sixty-six treatment-naive AITL patients between April 2014 and November 2022. Among them, thirty-three received chidamide in addition to CHOP (chidamide group), while thirty-three received CHOP alone (control group). The clinical characteristics were balanced between the two groups. All patients were scheduled to undergo up to six courses of treatment before transplantation.

Results

The chidamide group had a significantly longer median overall survival (OS) compared to the control group, with a median OS that was not reached, as opposed to 20 months in the control group (p = 0.002). In the control group, the median progression-free survival (PFS) was 11 months, while in the chidamide group, it was 22 months (p = 0.080). In the high-risk group (IPI ≥ 3), the chidamide group demonstrated notably superior complete response (CR) and overall response rate (ORR) compared to the control cohort (p = 0.002, p = 0.034). The PFS and OS in the chidamide group were not reached, and there were significant differences compared to the control group (p = 0.007, p = 0.003). The median OS of the transplanted group was longer than the non-transplanted group (p = 0.004). On multivariate analysis, chidamide group reduced the hazards of death in the total cohort.

Conclusion

As the study was non-random and retrospective, Chidamide combined with chemotherapy should be tested in randomized trials given its potential to improve prognosis in treatment-naive AITL patients. Furthermore, autologous hematopoietic stem cell transplantation (auto-HSCT) has demonstrated enhanced overall survival in individuals with AITL.

Clinical trial registration

https://clinicaltrials.gov/, NCT03268889.

Complete hematologic response in a patient with multiple pretreated angioimmunoblastic T-cell lymphoma after belinostat therapy followed by allogeneic stem cell transplantation: A case report

Key Clinical Message

Belinostat therapy followed by hematopoietic stem cell transplantation is a promising salvage strategy for heavily pretreated patients with peripheral T-cell lymphoma.

Abstract

Effective treatments for peripheral T-cell lymphoma in the relapsed and refractory (r/r) setting are limited. However, with the development and approval of innovative therapies, effective therapeutic options are becoming available for this patient population. This case report describes the treatment course of a patient with multiple r/r nodal follicular T-helper cell lymphoma of angioimmunoblastic type. Treatment with the histone deacetylase inhibitor belinostat as bridging, enabled allogeneic stem cell transplantation and resulted in a durable complete hematologic response for at least 21 months post-transplantation.

Navigating the Immune Maze: Pioneering Strategies for Unshackling Cancer Immunotherapy Resistance

Cancer immunotherapy has ushered in a transformative era in oncology, offering unprecedented promise and opportunities. Despite its remarkable breakthroughs, the field continues to grapple with the persistent challenge of treatment resistance. This resistance not only undermines the widespread efficacy of these pioneering treatments, but also underscores the pressing need for further research. Our exploration into the intricate realm of cancer immunotherapy resistance reveals various mechanisms at play, from primary and secondary resistance to the significant impact of genetic and epigenetic factors, as well as the crucial role of the tumor microenvironment (TME). Furthermore, we stress the importance of devising innovative strategies to counteract this resistance, such as employing combination therapies, tailoring immune checkpoints, and implementing real-time monitoring. By championing these state-of-the-art methods, we anticipate a paradigm that blends personalized healthcare with improved treatment options and is firmly committed to patient welfare. Through a comprehensive and multifaceted approach, we strive to tackle the challenges of resistance, aspiring to elevate cancer immunotherapy as a beacon of hope for patients around the world.