The emerging scenario of immunotherapy for T-cell Acute Lymphoblastic Leukemia: advances, challenges and future perspectives

Huaier inhibits autophagy and promotes apoptosis in T-cell acute lymphoblastic leukemia by down-regulating SIRT1

Objective

Due to the high drug resistance and relapse rate of T-cell acute lymphoblastic leukemia (T-ALL), the prognosis is usually poor. Therefore, there is an urgent need to find safer and more effective therapeutic drugs. Huaier and its preparations, as adjuvant drugs, have been widely used in the treatment of solid tumors and other diseases. However, the application of Huaier in leukemia is rarely reported. In this study, we investigated the anti-tumor effect of Huaier on T- ALL and its underlying mechanism.

Methods

Jurkat and MOLT-4 cells were treated with Huaier. Cell viability was evaluated by CCK-8 assay. The morphological changes of apoptotic cells were observed by Hoechst 33258 staining. Cell apoptosis was analyzed by flow cytometry. The expression levels of related proteins were assessed by Western blot.

Results

The results showed that Huaier significantly inhibited the proliferation of Jurkat and MOLT-4 cells in a dose- and time-dependent manner, with IC50 of 2.37 ± 0.10 and 1.93 ± 0.07 mg/mL at 48 h, respectively. Morphological changes and increased number of apoptotic cells were observed by Hoechst 33258 staining and flow cytometry. The apoptosis rates of Jurkat and MOLT-4 cells in 4 mg/mL group were 50.67 ± 1.36 % and 49.97 ± 5.43 %, respectively. Huaier promoted the expression of Cytochrome c, Cleaved Caspase-3, Cleaved PARP, p53, LC3-Ⅱ and p62 proteins, while inhibited the expression of SIRT1, ATG7 and Beclin 1 proteins. Treatment with SRT1720 (SIRT1 agonist) combined with Huaier rescued Huaier-induced apoptosis and increased the expression of autophagy-related proteins.

Conclusion

Huaier inhibits autophagy and promotes apoptosis of T-ALL cells by down-regulating SIRT1, which may be a potential drug for the treatment of T-ALL.

The NF-κB1/p50 Subunit Influences the Notch/IL-6-Driven Expansion of Myeloid-Derived Suppressor Cells in Murine T-Cell Acute Lymphoblastic Leukemia

T-cell acute lymphoblastic leukemia is an aggressive neoplasia due to hyper-proliferation of lymphoid progenitors and lacking a definitive cure to date. Notch-activating mutations are the most common in driving disease onset and progression, often in combination with sustained activity of NF-κB. Myeloid-derived suppressor cells represent a mixed population of immature progenitors exerting suppression of anti-cancer immune responses in the tumor microenvironment of many malignancies. We recently reported that in a transgenic murine model of Notch3-dependent T-cell acute lymphoblastic leukemia there is an accumulation of myeloid-derived suppressor cells, dependent on both Notch signaling deregulation and IL-6 production inside tumor T-cells. However, possible interaction between NF-κB and Notch in this context remains unexplored. Interestingly, we also reported that Notch3 transgenic and NF-κB1/p50 deleted double mutant mice display massive myeloproliferation. Here, we demonstrated that the absence of the p50 subunit in these mice dramatically enhances the induction and suppressive function of myeloid-derived suppressor cells. This runs in parallel with an impressive increase in IL-6 concentration in the peripheral blood serum, depending on IL-6 hyper-production by tumor T-cells from double mutant mice. Mechanistically, IL-6 increase relies on loss of the negative control exerted by the p50 subunit on the IL-6 promoter. Our results reveal the Notch/NF-κB cross-talk in regulating myeloid-derived suppressor cell biology in T-cell leukemia, highlighting the need to consider carefully the pleiotropic effects of NF-κB-based therapy on the tumor microenvironment.

The opportunities and challenges of using PD-1/PD-L1 inhibitors for leukemia treatment

Leukemia poses a significant clinical challenge due to its swift onset, rapid progression, and treatment-related complications. Tumor immune evasion, facilitated by immune checkpoints like programmed death receptor 1/programmed death receptor ligand 1 (PD-1/PD-L1), plays a critical role in leukemia pathogenesis and progression. In this review, we summarized the research progress and therapeutic potential of PD-L1 in leukemia, focusing on targeted therapy and immunotherapy. Recent clinical trials have demonstrated promising outcomes with PD-L1 inhibitors, highlighting their role in enhancing treatment efficacy. This review discusses the implications of PD-L1 expression levels on treatment response and long-term survival rates in leukemia patients. Furthermore, we address the challenges and opportunities in immunotherapy, emphasizing the need for personalized approaches and combination therapies to optimize PD-L1 inhibition in leukemia management. Future research prospects include exploring novel treatment strategies and addressing immune-related adverse events to improve clinical outcomes in leukemia. Overall, this review provides valuable insights into the role of PD-L1 in leukemia and its potential as a therapeutic target in the evolving landscape of leukemia treatment.

CD99 tumor associated antigen is a potential target for antibody therapy of T-cell acute lymphoblastic leukemia

Monoclonal antibodies (mAbs) are an effective drug for targeted immunotherapy in several cancer types. However, so far, no antibody has been successfully developed for certain types of cancer, including T-cell acute lymphoblastic leukemia (T-ALL). T-ALL is an aggressive hematologic malignancy. T-ALL patients who are treated with chemotherapeutic drugs frequently relapse and become drug resistant. Therefore, antibody-based therapy is promising for T-ALL treatment. To successfully develop an antibody-based therapy for T-ALL, antibodies that induce death in malignant T cells but not in nonmalignant T cells are required to avoid the induction of secondary T-cell immunodeficiency. In this review, CD99 tumor associated antigen, which is highly expressed on malignant T cells and lowly expressed on nonmalignant T cells, is proposed to be a potential target for antibody therapy of T-ALL. Since certain clones of anti-CD99 mAbs induce apoptosis only in malignant T cells, these anti-CD99 mAbs might be a promising antibody drug for the treatment of T-ALL with high efficiency and low adverse effects. Moreover, over the past 25 years, many clones of anti-CD99 mAbs have been studied for their direct effects on T-ALL. These outcomes are gathered here.

Experience of Care Among Adults With Acute Leukemia Near the End of Life: A Scoping Review

Background: Acute leukemia is a cancer of the blood and bone marrow with a high symptom burden and a high mortality rate in adults. The quality of end-of-life care among this patient population is deemed to be low based on health care administrative data, though the patient experience is not included in this evaluation. Objective: This scoping review aims at exploring and mapping the current research literature on the experience of care among adults with incurable acute leukemia near the end of life. Design: The JBI framework guided our scoping review, and the protocol was prospectively registered in the Open Science Forum. Results: A total of 5661 unique articles were screened for title and abstract, and 44 were selected for full text. After a manual search, five studies published in seven articles were selected for data extraction, including three qualitative and two quantitative studies. Two studies used family caregivers as patient proxies, two studies engaged patients directly, whereas one study obtained data from patients and family caregivers. Patient care in acute settings was reported in all studies, with most patients dying in acute care settings. Patients and family caregivers often valued an open and honest approach, with sufficient time for dialogue with their providers. Discussions about prognosis, palliative care, and hospice care were often late or incomplete. The medicalization of end-of-life care, including intensive care unit admissions and invasive medical procedures, were viewed as the norm by some providers, though perceived as distressing for both patients and their loved ones. Conclusions: Adults with acute leukemia face significant challenges in accessing high-quality end-of-life care brought about by the complex nature of their disease and its treatment. A systematic exploration of the end-of-life experience among these patients through direct patient engagement or by way of patient reporting proxies is needed.

Novel Biomarkers and Molecular Targets in ALL

PURPOSE OF REVIEW

Acute lymphoblastic leukemia (ALL) is a widely heterogeneous disease in terms of genomic alterations, treatment options, and prognosis. While ALL is considered largely curable in children, adults tend to have higher risk disease subtypes and do not respond as favorably to conventional chemotherapy. Identifying genomic drivers of leukemogenesis and applying targeted therapies in an effort to improve disease outcomes is an exciting focus of current ALL research. Here, we review recent updates in ALL targeted therapy and present promising opportunities for future research.

RECENT FINDINGS

With the utilization of next-generation sequencing techniques, the genomic landscape of ALL has greatly expanded to encompass novel subtypes characterized by recurrent chromosomal rearrangements, gene fusions, sequence mutations, and distinct gene expression profiles. The evolution of small molecule inhibitors and immunotherapies, and the exploration of unique therapy combinations are some examples of recent advancements in the field. Targeted therapies are becoming increasingly important in the treatment landscape of ALL to improve outcomes and minimize toxicity. Significant recent advancements have been made in the detection of susceptible genomic drivers and the use of novel therapies to target them.

Targeted treatment of T-cell acute lymphoblastic leukemia: latest updates from the 2022 ASH Annual Meeting

T-cell acute lymphoblastic leukemia (T-ALL) occurs in approximately 25-30% of adult ALL. Currently, treatment approaches for adult patients with T-ALL remain quite limited, with intensive multiagent chemotherapy serving as the backbone; however, the cure rate remains unsatisfactory. Thus, the discovery of novel therapeutic strategies, especially targeted therapies, is crucial. Clinical research efforts are now focused on adding targeted therapy that has selective activity for T-ALL to the backbone chemotherapy regimen. To date, nelarabine remains the only targeted agent specifically approved for relapsed T-ALL, and the use of nelarabine in the first-line regimen is still being studied. Meanwhile, a number of novel targeted therapies with low toxicity, such as immunotherapies, are being actively investigated. Chimeric antigen receptor (CAR) T-cell therapy for the treatment of T-cell malignancies has not been as successful as in treating B-ALL due to fratricide. Numerous approaches are now being designed to address this challenge. Novel therapies targeting molecular aberrations in T-ALL are also actively investigated. T-ALL lymphoblasts overexpress BCL2 protein, which makes it an intriguing therapeutic target. This review summarizes the latest updates on targeted treatment of T-ALL from the 2022 ASH annual meeting.