Experimental Hematology & Oncology最新文献

Pancreatic ductal adenocarcinoma (PDAC) is highly resistant to chemotherapy. However, PDAC with germline BRCA mutations, which lead to homologous recombination (HR) deficiency (HRD), demonstrated an increased sensitivity to platinum-based chemotherapy regimens. This increased chemosensitivity was also seen in PDACs with germline or somatic mutations in the DNA double-strand damage response (DDR) genes beyond canonical HR genes such as BRCA1, BRCA2, and PALB2. However, there are no consensus methods to determine HRD status; and neither is there a well-defined list of HR-DDR genes. In addition, how HRD and/or HR-DDR gene mutation status impacts the tumor immune microenvironment including tumor mutation burden (TMB), neoantigen load, T cell receptor (TCR) repertoire, and effector T cell infiltration is unknown. Thus, in this study, we developed a new method to categorize PDACs into HRD-positive and HRD-negative subgroups by using results from whole exome sequencing, whole genome sequencing, or both into consideration. We classified a cohort of 89 PDACs into HRD-positive (n = 18) and HRD-negative (n = 69) tumors. HR-DDR gene variants were identified more frequently in HRD-positive PDACs than HRD-negative PDACs, with RAD51B, BRCA2 and ATM alterations most frequently identified in HRD-positive PDACs. Notably, TMB and neoantigen load was significantly higher in HRD-positive PDACs compared to HRD-negative tumors. Interestingly, HRD-positive PDACs, PDACs with high tumor mutational burden, and PDAC with high neoantigen load were all associated with lower CD8 + T lymphocyte infiltration and T cell clonal diversity, suggesting a mechanism of resistance to immune checkpoint inhibitors (ICIs). Therefore, this study suggests that treatments to enhance effector T cell infiltration and T cell clonal diversity may overcome resistance to ICI-based immunotherapy in HRD-positive PDACs.

Myelodysplastic syndromes (MDS) is a heterogeneous group of pre-leukemic diseases characterized by peripheral blood cytopenia, morphologic dysplasia, and an increased risk of transformation to leukemia. MDS develop from genetically mutant clonal hematopoietic stem and progenitor cells (HSPCs) which have defects in generating mature functional blood cells due to impaired differentiation and/or survival activities. In addition, mutant HSPCs also inhibit the generation of new blood cells from remaining healthy HSPCs. Thus, the complete elimination of mutant HSPCs is the optimal goal for MDS treatment. However, most current therapies for MDS are little more than palliative, primarily addressing cytopenia-related symptoms and improving the quality of life. Only the hypomethylating agents (HMA) lenalidomide and imetelstat reduced the mutational burden, and then only in a small subset of cases. Many HMA-based combination therapies failed to show benefits superior to single-agent HMA treatment in clinical trials. At the present time, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is still the only cure for the minority of qualified patients who have HLA-matched donors. Novel effective treatments are urgently needed. Here we summarize the current standard therapeutic approaches for MDS patients and discuss major advances in MDS research and treatments. We also discuss major challenges and potential solutions to overcome these challenges for future MDS research and drug development.

Background: Triple-negative breast cancer (TNBC) is commonly characterized by high-grade and aggressive features, resulting in an augmented likelihood of distant metastasis and inferior prognosis for patients. Tumor immune microenvironment (TME) has been recently considered to be tightly correlated with tumor progression and immunotherapy response. However, the actual heterogenous TME within TNBC remains more explorations.

Methods: The thorough analyses of different cell types within TME were conducted on the self-tested single-cell RNA sequencing dataset which contained nine TNBC treatment-naïve patients, including subclusters classification, CellChat algorithm, transcription factors (TFs) expression, pseudotime analysis and functional enrichment assay. The malignant epithelial cluster was confirmed by copy number variations analysis, and subsequently LASSO-Cox regression was carried out to establish a Malignant Cell Index (MCI) model on the basis of five crucial genes (BGN, SDC1, IMPDH2, SPINT1, and UQCRFS1), which was validated in several TNBC cohorts through Kaplan-Meier survival and immunotherapy response analyses. The public spatial transcriptome, proteome data and qRT-PCR, western blotting experiments were exploited to corroborate UQCRFS1 expression in RNA and protein levels. Additionally, functional experiments were implemented to unravel the impacts of UQCRFS1 on TNBC cells.

Results: The diverse subclusters of TME cells within TNBC were clarified to display distinct characteristics in cell-cell interactions, TFs expression, differentiation trajectory and functional pathways. Particularly, IL32^high Treg imparted an essential effect on tumor evasion and predicted a worsened prognosis of TNBC patients. Furthermore, MCI model enabled to notify the inferior prognosis and immunotherapy resistance in TNBC. Ultimately, UQCRFS1 knockdown dampened the proliferative and migratory competence in vitro as well as tumor growth in vivo of TNBC cells.

Conclusions: Our study offers innovative perspectives on comprehending the heterogeneity within TME of TNBC, thereby facilitating the elucidation of TNBC biology and providing clinical recommendations for TNBC patients' prognosis, such as IL32^high Treg infiltration, MCI evaluation, and UQCRFS1 expression.

Platelets play a critical role in tumor immunity, particularly in promoting cancer progression. Numerous studies suggest that platelets could serve as a novel target for cancer immunotherapy, however, no comprehensive reviews have yet summarized and discussed this potential. Our review provides an in-depth discussion of the roles and mechanisms of platelets within both the immunosuppressive tumor microenvironment and the anti-tumor immune microenvironment. Additionally, we summarize the key therapeutic targets and approaches for clinical translation. This work offers essential insights for reprogramming platelets to shift their function from tumor promotion to tumor suppression, providing a foundation for the development of novel immunotherapeutic strategies and related research.

Neutrophil extracellular traps (NETs) are complex, web-like structures consisting of DNA intertwined with antimicrobial proteins, which neutrophils release upon immune activation. These structures play a crucial role in pathogen elimination, particularly in infectious diseases. However, their involvement in various pathological conditions is multifaceted and context-dependent, while NETs contribute to host defense against infections, they can also exacerbate sterile inflammation, autoimmune disorders, and tumor progression. This review provides a comprehensive analysis of the molecular mechanisms governing NET formation and examines their interactions with immune cells, emphasizing how these interactions shape immune responses and drive disease dynamics. Furthermore, it explores ongoing clinical trials and emerging therapeutic strategies targeting NETs, offering critical insights into their potential translational applications in clinical practice.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating malignancy with a 5-year overall survival (OS) rate of approximately 12%. More than 90% of PDAC patients harbor oncogenic mutations in the Kirsten rat sarcoma viral homolog (KRAS) gene. MRTX1133 (MRTX), a novel inhibitor of KRAS^G12D (the most common KRAS mutation found in pancreatic and colon cancers) has shown promise as a therapeutic agent. To address reported resistance to MRTX, we adapted our anti-leukemia co-targeting strategy and evaluated a combination of MRTX and Bedaquiline (BED), an FDA-approved inhibitor of mitochondrial ATP production, in in vitro human PDAC models. The combination of MRTX and BED demonstrated enhanced cytotoxic effects by disrupting all 11 genes within the DNA helicase family (CMG complex: CDC45-MCM-GINS), which are essential for initiating DNA replication and regulating cell cycle progression. Notably, real-world data analysis from Caris Life Sciences and NCI-TCGA database revealed that low transcriptomic expression of the DNA helicase CMG complex was significantly associated with prolonged survival (e.g., low CDC45 expression and low GINS2 expression with greater than 8 months longer overall survival) in PDAC patients with KRAS^G12 mutations (N = 9,717; P < 0.00001). However, this combination therapy also triggered strong pro-survival nuclear reprogramming. This effect was mediated by significant genetic activation of an NFκB2-DDIT (DNA damage-induced transcript) axis, which supported tumor chromosomal integrity and DNA repair mechanisms. To overcome NFκB2-driven resistance mechanisms, we explored a triple-targeting strategy that addresses metabolic and genomic plasticity in addition to actively intercepting cell division. This approach combines MRTX1133, Bedaquiline, and the NFκB2 inhibitor SN52, offering a novel therapeutic avenue to treat aggressive pancreatic cancer and potentially improve patient outcomes.

Menin inhibitors (MENINis) represent a novel and promising class of therapeutic agents for acute leukemia (AL). AL subtypes driven by overexpressed HOXA9/MEIS1, such as those characterized by KMT2A-rearranged (KMT2Ar) or NPM1-mutated (NPM1m) AL, display sensitivity to MENINi. Consequently, approximately 40-50% of acute myeloid leukemia (AML) and 5-15% of acute lymphoblastic leukemia (ALL) patients may potentially benefit from MENINi-based therapy. At the 2024 ASH annual meeting, updated clinical data regarding monotherapy with MENINis in AL, including revumenib, bleximenib, enzomenib and BN104, were presented. Moreover, combination therapies based on MENINis were also reported to be highly effective in refractory/relapsed, or newly diagnosed KMT2Ar- and NPM1m-AML patients. Evidently, MENINis have demonstrated a considerable efficacy in KMT2Ar- and NPM1m-AML patients with a well-tolerance. Furthermore, the therapeutic effects of venetoclax plus azacitidine or "3 + 7" regimens were further enhanced by the addition of MENINis in KMT2Ar- and NPM1m-AML patients. Therefore, MENINis offer new therapeutic prospects for AML patients, particularly for those with high-risky and poor-prognostic on-target subtypes.