Overexpression of annexin A5 might guide the gemtuzumab ozogamicin treatment choice in patients with pediatric acute myeloid leukemia

Higher expression of programmed cell death 4 (PDCD4) in acute myeloid leukemia is associated with better prognosis after chemotherapy

Acute myeloid leukemia (AML) is a common heterogeneous malignancy. Novel molecular markers aid diagnosis, patient sub-categorization, and optimal clinical decisions. Here, we explored the prognostic implications associated with the expression of the programmed cell death (PDCD) family of molecules in AML patients. Based on the findings from the TCGA and OHSU cohorts, we observed that the mRNA abundance of PDCD4 is significantly higher compared to other molecules within the PDCD family. Furthermore, high expression of PDCD4 was associated with predicted long-term patient survival in diagnosed AML patients. In the chemotherapy group, patients with high PDCD4 expression showed a tendency toward longer overall survival (OS) (P = 0.0266) and event-free survival (EFS) (P = 0.0008). High PDCD4 levels served as a favorable independent predictor for both OS and EFS in AML patients. However, subgroup analyses in the hematopoietic stem cell transplantation (HSCT) group revealed no significant difference in OS or EFS between individuals with high and low PDCD4 expression. Furthermore, in the low PDCD4 expression group, AML patients who underwent HSCT experienced improved survival outcomes (P = 0.0015), helping to mitigate the unfavorable prognosis associated with PDCD4 downregulation. Conversely, in the high PDCD4 expression group, HSCT offered a notable short-term survival advantage, while patients with high PDCD4 expression responded favorably to long-term survival through chemotherapy. Biological function enrichment showed that the expression of PDCD4 was correlated with complement and coagulation cascades, cell receptor signaling pathways, and cholesterol metabolism. The findings from this study will aid in better categorizing heterogeneous AML patients and guiding more appropriate clinical decision-making.

Treating CD33-Positive de novo Acute Myeloid Leukemia in Pediatric Patients: Focus on the Clinical Value of Gemtuzumab Ozogamicin

Although survival in pediatric acute myeloid leukemia (AML) has increased considerably over the past decades, refractory disease and relapse rates remain high. Refractory and relapsed disease are difficult to treat, with overall survival rates less than 40-50%. Preventing relapse should, therefore, be one of the highest priorities. Current conventional chemotherapy regimens are hard to intensify due to associated toxic complications, hence more effective therapies that do not increase toxicity are needed. A promising targeted agent is the CD33-directed antibody-drug conjugate gemtuzumab ozogamicin (GO). Because CD33 is highly expressed on leukemic cells in the majority of AML patients, GO can be useful for a broad range of patients. Better relapse-free survival (RFS) after therapy including GO has been reported in several pediatric clinical trials; however, ambiguity about the clinical value of GO in newly diagnosed children remains. Treatment with GO in de novo AML patients aged ≥1 month, in combination with standard chemotherapy is approved in the United States, whereas in Europe, GO is only approved for newly diagnosed patients aged ≥15 years. In this review, we aimed to clarify the clinical value of GO for treatment of newly diagnosed pediatric AML patients. Based on current literature, GO seems to have additional value, in terms of RFS, and acceptable toxicity when used in addition to chemotherapy during initial treatment. Moreover, in KMT2A-rearranged patients, the clinical value of GO was even more evident. Also, we addressed predictors of response, being CD33 expression and SNPs, PgP-1 and Annexin A5. The near finalized intent-to-file clinical trial in the MyeChild consortium investigates whether fractionated dosing has additional value for pediatric AML, which may pave the way for a broader application of GO in pediatric AML.

The m6A reader IGF2BP3 promotes acute myeloid leukemia progression by enhancing RCC2 stability

N6-methyladenosine (m6A) is the most abundant posttranscriptional modification of mRNA in eukaryotes. Recent evidence suggests that dysregulated m6A-associated proteins and m6A modifications play a pivotal role in the initiation and progression of diseases such as cancer. Here, we identified that IGF2BP3 is specifically overexpressed in acute myeloid leukemia (AML), a subtype of leukemia associated with poor prognosis and high genetic risk. IGF2BP3 is required for maintaining AML cell survival in an m6A-dependent manner, and knockdown of IGF2BP3 dramatically suppresses the apoptosis, reduces the proliferation, and impairs the leukemic capacity of AML cells in vitro and in vivo. Mechanistically, IGF2BP3 interacts with RCC2 mRNA and stabilizes the expression of m6A-modified RNA. Thus, we provided compelling evidence demonstrating that the m6A reader IGF2BP3 contributes to tumorigenesis and poor prognosis in AML and can serve as a target for the development of cancer therapeutics.

Inhibiting a protein that is overexpressed in the bone marrow of acute myeloid leukemia patients may prove valuable in treating the disease. Recent research has demonstrated the important role played by epigenetics in cancers – for example, disruption to a common mRNA modification known as m6A can result in cancer initiation and progression. Jianchuan Deng and co-workers at Chongqing Medical Universit0y, China, examined the role of an m6A-related protein called IGF2BP3 in mice models and samples from leukemia patients. IGF2BP3 was overexpressed in patients’ bone marrows, the levels of the protein correlating with extent of proliferation of leukemia cells and poor prognosis. IGF2BP3 stabilises the activity of a known cancer-related protein, promoting leukemia progression. Blocking IGF2BP3 expression reduced cell proliferation and impaired activity of leukemic cells, suggesting the protein may be a useful therapeutic target.

Copy number variation analysis of m6 A regulators identified METTL3 as a prognostic and immune-related biomarker in bladder cancer

PURPOSE

Growing evidence has demonstrated an indispensable role for N⁶ -methyladenosine (m⁶ A) in human diseases, but the copy number variations (CNVs) of m⁶ A regulatory genes in bladder cancer (BLCA) remains largely unknown.

METHODS

We investigated the CNVs on all known m⁶ A regulatory genes using the Cancer Genome Atlas (TCGA) database. The association between CNV events and clinicopathological as well as molecular characteristics of BLCA patients were explored. Gene set enrichment analysis (GSEA) was implemented to reveal relative cellular processes. Association between m⁶ A regulatory genes and immune infiltrates was analyzed by The Tumor Immune Estimation Resource (TIMER) database.

RESULTS

CNV events of m⁶ A regulatory genes were frequently observed in BLCA. CNVs of METTL3, METTL14, and METTL16 correlated with molecular characteristics of BLCA patients including TP53 mutation. CNVs of METTL3 associated with the overall survival (OS) of BLCA patients. METTL3 was also associated with several cancer-related cellular processes, including mitotic spindle assembly, G2/M checkpoint, and E2F targets signaling pathway. Besides, the CNVs of m⁶ A regulatory genes were correlated with specific kinds of immune infiltrates.

CONCLUSIONS

There are significant correlations between m⁶ A regulatory genes with CNVs and clinicopathological characteristics. METTL3 with CNVs were associated with the immune infiltrates and performed as a prognostic marker in BLCA.

Therapeutic Targeting of Acute Myeloid Leukemia by Gemtuzumab Ozogamicin

Acute myeloid leukemia (AML) is a complex hematological malignancy characterized by genetic and clinical heterogeneity and high mortality. Despite the recent introduction of novel pharmaceutical agents in hemato-oncology, few advancements have been made in AML for decades. In the last years, the therapeutic options have rapidly changed, with the approval of innovative compounds that provide new opportunities, together with new challenges for clinicians: among them, on 1 September, 2017 the Food and Drug Administration granted approval for Gemtuzumab Ozogamicin (GO) in combination with daunorubicin and cytarabine for the treatment of adult patients affected by newly diagnosed CD33⁺ AML. Benefits of GO-based regimens were also reported in the pre- and post-transplantation settings. Moreover, several biomarkers of GO response have been suggested, including expression of CD33 and multidrug resistance genes, cytogenetic and molecular profiles, minimal residual disease and stemness signatures. Among them, elevated CD33 expression on blast cells and non-adverse cytogenetic or molecular risk represent largely validated predictors of good response.