Targeting Hedgehog (Hh) Pathway for the Acute Myeloid Leukemia Treatment

Synthesis of pyridyl pyrimidine hedgehog signaling pathway inhibitors and their antitumor activity in human pancreatic cancer

Pancreatic cancer (PC) is an extremely lethal malignant tumor. The Hedgehog (Hh) signaling pathway is implicated in embryonic development, regulation of tumor stem cells, and modulation of the tumor microenvironment. Aberrant activation of Hh pathway leads to the development of multiple malignant tumors, especially Hh-driven PC. Targeting the molecular regulation of the Hh signaling pathway presents a promising therapeutic strategy for PC treatment. Hence, there is a high demand for novel molecules that inhibit the Hh pathway. In this study, the Hh pathway inhibitors bearing pyridyl pyrimidine skeleton were designed, synthesized, and characterized. Among them, N-(4-((dimethylamino)methyl)phenyl)-4-((4-(pyridin-3-yl)pyrimidin-2-yl)amino)benzamide (B31) emerged as the most potent analog following screening with a Gli luciferase reporter assay, competing with cyclopamine in the binding site of Smo protein. Molecular simulation revealed that B31 interacts with Smo through hydrogen bonds, hydrophobic interactions, and electrostatic forces. B31 inhibited PC cell proliferation, migration, and induced apoptosis by suppressing Gli1 expression at both the transcriptional and translational levels. Moreover, B31 significantly regressed subcutaneous tumors formed by BxPC-3 cells in nude mice without inducing toxic effects. These results underscore the enhanced efficacy of B31 in the PC model and offer a new avenue for developing effective Hh pathway inhibitors for clinical PC treatment.

Identification of Prognostic Genes in Acute Myeloid Leukemia Microenvironment: A Bioinformatic and Experimental Analysis

Acute myeloid leukemia (AML) is a lethal hematologic malignancy with a variable prognosis that is highly dependent on the bone marrow microenvironment. Consequently, a better understanding of the AML microenvironment is crucial for early diagnosis, risk stratification, and personalized therapy. In recent years, the role of bioinformatics as a powerful tool in clarifying the complexities of cancer has become more prominent. Gene expression profile and clinical data of 173 AML patients were downloaded from the TCGA database, and the xCell algorithm was applied to calculate the microenvironment score (MS). Then, the correlation of MS with FAB classification, and CALGB cytogenetic risk category was investigated. Differentially expressed genes (DEGs) were identified, and the correlation analysis of DEGs with patient survival was done using univariate cox. The prognostic value of candidate prognostic DEGs was confirmed based on the GEO database. In the last step, real-time PCR was used to compare the expression of the top three prognostic genes between patients and the control group. During TCGA data analysis, 716 DEGs were identified, and survival analysis results showed that 152 DEGs had survival-related changes. In addition, the prognostic value of 31 candidate prognostic genes was confirmed by GEO data analysis. Finally, the expression analysis of FLVCR2, SMO, and CREB5 genes, the most related genes to patients' survival, was significantly different between patients and control groups. In summary, we identified key microenvironment-related genes that influence the survival of AML patients and may serve as prognostic and therapeutic targets.

Recent advance of clinically approved small-molecule drugs for the treatment of myeloid leukemia

Myeloid leukemia denotes a hematologic malignancy characterized by aberrant proliferation and impaired differentiation of blood progenitor cells within the bone marrow. Despite the availability of several treatment options, the clinical outlook for individuals afflicted with myeloid leukemia continues to be unfavorable, making it a challenging disease to manage. Over the past, substantial endeavors have been dedicated to the identification of novel targets and the advancement of enhanced therapeutic modalities to ameliorate the management of this disease, resulting in the discovery of many clinically approved small-molecule drugs for myeloid leukemia, including histone deacetylase inhibitors, hypomethylating agents, and tyrosine kinase inhibitors. This comprehensive review succinctly presents an up-to-date assessment of the application and synthetic routes of clinically sanctioned small-molecule drugs employed in the treatment of myeloid leukemia. Additionally, it provides a concise exploration of the pertinent challenges and prospects encompassing drug resistance and toxicity. Overall, this review effectively underscores the considerable promise exhibited by clinically endorsed small-molecule drugs in the therapeutic realm of myeloid leukemia, while concurrently shedding light on the prospective avenues that may shape the future landscape of drug development within this domain.

The role of bone marrow microenvironment (BMM) cells in acute myeloid leukemia (AML) progression: immune checkpoints, metabolic checkpoints, and signaling pathways

Acute myeloid leukemia (AML) comprises a multifarious and heterogeneous array of illnesses characterized by the anomalous proliferation of myeloid cells in the bone marrow microenvironment (BMM). The BMM plays a pivotal role in promoting AML progression, angiogenesis, and metastasis. The immune checkpoints (ICs) and metabolic processes are the key players in this process. In this review, we delineate the metabolic and immune checkpoint characteristics of the AML BMM, with a focus on the roles of BMM cells e.g. tumor-associated macrophages, natural killer cells, dendritic cells, metabolic profiles and related signaling pathways. We also discuss the signaling pathways stimulated in AML cells by BMM factors that lead to AML progression. We then delve into the roles of immune checkpoints in AML angiogenesis, metastasis, and cell proliferation, including co-stimulatory and inhibitory ICs. Lastly, we discuss the potential therapeutic approaches and future directions for AML treatment, emphasizing the potential of targeting metabolic and immune checkpoints in AML BMM as prognostic and therapeutic targets. In conclusion, the modulation of these processes through the use of directed drugs opens up new promising avenues in combating AML. Thereby, a comprehensive elucidation of the significance of these AML BMM cells' metabolic and immune checkpoints and signaling pathways on leukemic cells can be undertaken in the future investigations. Additionally, these checkpoints and cells should be considered plausible multi-targeted therapies for AML in combination with other conventional treatments in AML. Video Abstract.

High GLI-1 Expression is a Reliable Indicator of Bad Prognosis in Newly Diagnosed Acute Leukemia Patients

PURPOSE

To explore the expression and prognostic significance of Hedgehog signaling transcription factor GLI-1 in newly diagnosed acute myeloid leukemia (AML) patients.

METHODS

Clinical specimens were obtained from 46 recently diagnosed AML patients. Real-time qPCR was used to measure the GLI-1 mRNA expression in bone marrow mononuclear cells.Also, the relationship between GLI-1 mRNA levels and clinical variables and prognostic variables was assessed.

RESULTS

GLI-1 was overexpressed in the bone marrow samples of our patients. GLI-1mRNA expression did not differ significantly across different age groups, between both sexes, or between different FAB subtypes (P = 0.882, P = 0.246, and P = 0.890, respectively). GLI-1 expression varied significantly in different risk categories, with the greatest levels observed in 11 patients with poor risk (24.6 versus 22.7) compared to intermediate risk (5.2 versus 3.9; P = 0.006) and favorable risk (4.2 versus 3; P = 0.001). Comparing patients with the wild FLT3 allele to those with the mutant one, GLI-1 gene levels were considerably greater in those with the mutant allele of FLT3.Following induction chemotherapy, the levels of GLI-1 mRNA were significantly higher in 22 patients who did not experience complete remission (CR) diagnosed with de novo non-acute promyelocytic leukemia (APL) compared to 17 patients who did (P = 0.017). Significantly greater levels of expression were observed in each category of the patients with favorable risk; wild FLT3 allele (P = 0.033) and CR failure P = 0.005).

CONCLUSION

GLI-1 overexpression is a risk factor for poor prognosis and could be a novel therapeutic target for AML.

Acute myeloid leukemia: novel mutations and their clinical implications

Acute myeloid leukemia (AML) is a heterogenous and challenging hematological malignancy with suboptimal outcomes. The implications of advanced technologies in the genetic characterization of AML have enhanced the understanding of individualized patient risk, which has also led to the development of new therapeutic strategies. A comprehensive study of novel mutations is essential to moderate the complicacies in patient management and achieve optimal outcomes in AML. In this review, we summarized the clinical relevance of important novel mutations, including TET2, ETV6, SATB1, EZH2, PTPN11, and U2AF1, which impact the prognosis of AML. TET2 mutation can lead to DNA hypermethylation, and gene fusion, and mutation in ETV6 disrupts hematopoietic transcription machinery, SATB1 downregulation aggravates the disease, and EZH2 mutation confers resistance to chemotherapy. PTPN11 mutation influences the RAS-MAPK signaling pathway, and U2AF1 alters the splicing of downstream mRNA. The systemic influence of these mutations has adverse consequences. Therefore, extensive research on novel mutations and their mechanism of action in the pathogenesis of AML is vital. This study lays out the perspective of expanding the apprehension about AML and novel drug targets. The combination of advanced genetic techniques, risk stratification, ongoing improvements, and innovations in treatment strategy will undoubtedly lead to improved survival outcomes in AML.

Bone Marrow Mesenchymal Stem Cell (BMSC)-Derived Exosomes Regulates Growth of Breast Cancer Cells Mediated by Hedgehog Signaling Pathway

BMSCs promote breast cancer development mainly through tumor microenvironment pathway and secreting exosomes. However, the mechanism is unclear. This study mainly explores whether BMSC-derived exosomes influence breast cancer by mediating Hedgehog signaling pathway. MCF-7 and BMSC were cultured and then assigned into MCF-7 +Vehicle group, MCF-7+ Exosome group, and MCF-7+Exosome+Gant61 (Hedgehog signaling blocker) group followed by analysis of cell proliferation and migration, p-Akt and β-catenin expression. MCF-7+Exosome group had the highest OD450 value compared to other two groups (P >0.05). In addition, migration distance of MCF-7 cells was the highest in MCF-7+Exosome group without difference between other two groups (P >0.05). Gli1 and SMO expression in MCF-7+Exosome group was highest compared to other two groups (P >0.05). In conclusion, exosome from BMSC promotes breast cancer cell proliferation and migration. The mechanism may be through raising GLI1, Smo protein expression, further raising the Hedgehog signaling pathway to some extent.

Molecular targets for the treatment of AML in the forthcoming 5th World Health Organization Classification of Haematolymphoid Tumours

INTRODUCTION

Acute myeloid leukemia (AML) is a genetically heterogeneous disease for which the treatment armamentarium has been historically restricted to chemotherapy. However, genomic and epigenomic alterations that contribute to AML initiation, maintenance, and relapse have disclosed new insights to the 5th update in WHO Classification of Haematolymphoid Tumours.

AREAS COVERED

After four decades of intensive chemotherapy as a 'one-size-fits-all' concept, several targeted agents have been approved for the treatment of AML. Several compounds, directed against regulators of apoptotic, epigenetic, or micro-environmental pathways, and immune-system modulators, are currently in development and investigation in clinical trials. We review advances in target-based therapy for AML focusing on their mechanism of action, examining the intracellular events and pathways, and the results from published clinical trials.

EXPERT OPINION

To improve patient clinical outcomes, find new biomarkers for therapeutic response, and pinpoint patients who might benefit from novel targeted medicines, next-generation sequencing is being used to evaluate AML-associated mutations. In fact, the new 5th edition of WHO classification has reaffirmed the importance of genetically defined entities that have a prognostic impact, but not all have a specific treatment available. New class of target drugs are in clinical development and could be beneficial to improve the therapeutic armamentarium available.

Bone Marrow Mesenchymal Stem Cells (BMSC)-Derived miR-134 Inhibits Cervical Cancer Metastasis

The miRNA had been brand-new hot spot for study on pathogenesis of malignant tumor and seeking prevention strategy. The occurrence and development of tumor could be regulated by Gli1/Snail signaling pathway through Hedgehog channel. Our study intends to discuss the role of miRNA derived from BMSC in HPV. The miR-134 derived from BMSC was analyzed through nano-particles and observed under fluorescence microscope along with analysis of miR-134 expression by RTPCR. The HPV rat model was established to analyze miR-134’s role in HPV metastasis in vivo. The level of miR-134 in the staging of N2–N3 was lower than that in N0–N1 staging and lower in patients with metastatic cervical cancer tissue than patients without distant metastasis. Gli1 level could be targeted by miR-134. miR-134 inhibits HPV proliferation and migration by regulating the Gli1/Snail channel through Hedgehog pathway. The inhibitory effect of miR-134 on HH signal pathway could be reversed by Gli1 overexpression. The rats’ EMT and HPV growth was significantly restrained by miR-134 through silencing of Gli1. In conclusion, the growth of HPV is restrained by miR-134 derived from BMSC by regulating Gli1/Snail pathway through Hedgehog channel.

Reduced PTCH2 expression is associated with glioma development through its regulation of the PTEN/AKT signaling pathway

Mutations in the human protein patched homolog (PTCH) gene have been demonstrated to be associated with cancer development in several types of malignancy. However, the underlying mechanism of PTCH-associated cancer development remains poorly understood, to the best of our knowledge. In the present study, the expression of PTCH2 in glioma tumor tissues from The Cancer Genome Atlas (TCGA) database and clinical patients with glioma were measured. Reduced expression levels of PTCH2 were observed in patients with glioma with poor prognose. In vitro, overexpression of PTCH2 significantly suppressed the proliferation and invasion of the glioma cell lines, LN229 and U87-MG. Mechanistically, PTCH2 upregulated the expression of tumor suppressor PTEN, thereby leading to the suppression of pro-survival AKT signals in glioma. Reduced expression of PTEN and enhanced expression of AKT promoted glioma development in vitro and in vivo. Blockade of PTCH2/AKT signals efficiently strengthened the anticancer effects of chemotherapy and prolonged the survival time in tumor-bearing mice, which provided a novel insight into potential treatment strategies for glioma in the clinic.

Canonical Hedgehog Pathway and Noncanonical GLI Transcription Factor Activation in Cancer

The Hedgehog signaling pathway is one of the fundamental pathways required for development and regulation of postnatal regeneration in a variety of tissues. The pathway has also been associated with cancers since the identification of a mutation in one of its components, PTCH, as the cause of Basal Cell Nevus Syndrome, which is associated with several cancers. Our understanding of the pathway in tumorigenesis has expanded greatly since that initial discovery over two decades ago. The pathway has tumor-suppressive and oncogenic functions depending on the context of the cancer. Furthermore, noncanonical activation of GLI transcription factors has been reported in a number of tumor types. Here, we review the roles of canonical Hedgehog signaling pathway and noncanonical GLI activation in cancers, particularly epithelial cancers, and discuss an emerging concept of the distinct outcomes that these modes have on cancer initiation and progression.

Profile of Glasdegib for the Treatment of Newly Diagnosed Acute Myeloid Leukemia (AML): Evidence to Date

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy primarily affecting older adults. Historically, the highest rates of response have been achieved with intensive induction chemotherapy; however, a significant portion of older or unfit adults with AML are unable to tolerate intensive therapy or have chemotherapy-resistant disease, creating a large need for active and less intensive treatment strategies. Glasdegib, an oral inhibitor of the transmembrane protein Smoothened (SMO) involved in the Hedgehog (Hh) signaling pathway, was approved in 2018 for older or unfit adults with AML and attained a role in clinical practice after showing an overall survival (OS) advantage when combined with the established agent low-dose cytarabine (LDAC). Since that time, however, several other highly active lower intensity therapies such as venetoclax plus a hypomethylating agent (HMA) have garnered a dominant role in the treatment of this patient population. In this review, we summarize the role of glasdegib in the current treatment landscape of newly diagnosed AML and discuss ongoing investigations into its role in novel combination therapies.

Theragnostic strategies harnessing the self-renewal pathways of stem-like cells in the acute myeloid leukemia

Acute myelogenous leukemia (AML) is a genetically heterogeneous and aggressive cancer of the Hematopoietic Stem/progenitor cells. It is distinguished by the uncontrollable clonal growth of malignant myeloid stem cells in the bone marrow, venous blood, and other body tissues. AML is the most predominant of leukemias occurring in adults (25%) and children (15-20%). The relapse after chemotherapy is a major concern in the treatment of AML. The overall 5-year survival rate in young AML patients is about 40-45% whereas in the elderly patients it is less than 10%. Leukemia stem-like cells (LSCs) having the ability to self-renew indefinitely, repopulate and persist longer in the G0/G1 phase play a crucial role in the AML relapse and refractoriness to chemotherapy. Hence, novel treatment strategies and diagnostic biomarkers targeting LSCs are being increasingly investigated. Through this review, we have explored the signaling modulations in the LSCs as the theragnostic targets. The significance of the self-renewal pathways in overcoming the treatment challenges in AML has been highlighted.

Hedgehog Autoprocessing: From Structural Mechanisms to Drug Discovery

Hedgehog (Hh) signaling plays pivotal roles in embryonic development. In adults, Hh signaling is mostly turned off but its abnormal activation is involved in many types of cancer. Hh signaling is initiated by the Hh ligand, generated from the Hh precursor by a specialized autocatalytic process called Hh autoprocessing. The Hh precursor consists of an N-terminal signaling domain (HhN) and a C-terminal autoprocessing domain (HhC). During Hh autoprocessing, the precursor is cleaved between N- and C-terminal domain followed by the covalent ligation of cholesterol to the last residue of HhN, which subsequently leads to the generation of Hh ligand for Hh signaling. Hh autoprocessing is at the origin of canonical Hh signaling and precedes all downstream signaling events. Mutations in the catalytic residues in HhC can lead to congenital defects such as holoprosencephaly (HPE). The aim of this review is to provide an in-depth summary of the progresses and challenges towards an atomic level understanding of the structural mechanisms of Hh autoprocessing. We also discuss drug discovery efforts to inhibit Hh autoprocessing as a new direction in cancer therapy.

Transcriptomic analysis reveals proinflammatory signatures associated with acute myeloid leukemia progression

Numerous studies have been performed over the last decade to exploit the complexity of genomic and transcriptomic lesions driving the initiation of acute myeloid leukemia (AML). These studies have helped improve risk classification and treatment options. Detailed molecular characterization of longitudinal AML samples is sparse, however; meanwhile, relapse and therapy resistance represent the main challenges in AML care. To this end, we performed transcriptome-wide RNA sequencing of longitudinal diagnosis, relapse, and/or primary resistant samples from 47 adult and 23 pediatric AML patients with known mutational background. Gene expression analysis revealed the association of short event-free survival with overexpression of GLI2 and IL1R1, as well as downregulation of ST18. Moreover, CR1 downregulation and DPEP1 upregulation were associated with AML relapse both in adults and children. Finally, machine learning-based and network-based analysis identified overexpressed CD6 and downregulated INSR as highly copredictive genes depicting important relapse-associated characteristics among adult patients with AML. Our findings highlight the importance of a tumor-promoting inflammatory environment in leukemia progression, as indicated by several of the herein identified differentially expressed genes. Together, this knowledge provides the foundation for novel personalized drug targets and has the potential to maximize the benefit of current treatments to improve cure rates in AML.

SPRY1 promotes cell proliferation and inhibits apoptosis by activating Hedgehog pathway in acute myeloid leukemia

OBJECTIVE

The aim of this study was to determine the biological function of Sprouty 1 (SPRY1) on acute myeloid leukemia (AML), and to investigate the potential mechanism.

METHODS

The expression of SPRY1 and the prognostic values of SPRY1 were assessed through the analysis of the Cancer Genome Atlas. Meanwhile, the expression of SPRY1 in AML cells was determined by qRT-PCR and western blot. Then, the biological function of SPRY1 on the proliferation, cell cycle and apoptosis in K-562 and HL-60 cells were tested using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, colony-formation assay, 5-ethynyl-20-deoxyuridine assay and flow cytometry. Additionally, the protein expressions were measured by western blot.

RESULTS

We found that SPRY1 was markedly overexpressed in the cells of the patients with AML, and the patients with AML having a high SPRY1 expression has a bad prognosis. The proliferation and cell cycle progression in K-562 and HL-60 cells were notably promoted by SPRY1 overexpression, but inhibited by SPRY1 knockdown. Meanwhile, the apoptosis of K-562 and HL-60 cells was significantly repressed by SPRY1 overexpression and facilitated by SPRY1 knockdown. In addition, we found that SPRY1 overexpression significantly activated the Hedgehog pathway in AML cells. The function of SPRY1 on the proliferation, cell cycle and apoptosis was reversed by Gli1 in K-562 and HL-60 cells.

DISCUSSION

Identifying new biomarkers and exploring the pathogenesis of AML is urgent to improve the disease surveillance for patients with AML.

CONCLUSIONS

SPRY1 could facilitate cell proliferation and cell cycle progression, and suppress cell apoptosis via activating the Hedgehog pathway in AML.

The BET bromodomain inhibitor ZEN-3365 targets the Hedgehog signaling pathway in acute myeloid leukemia

Modern cancer therapies increased the survival rates of acute myeloid leukemia (AML) patients tremendously. However, the complexity of the disease and the identification of new targets require the adaptation of treatment protocols to reduce side effects and increase benefit for the patients. One key regulator of leukemogenesis and chemotherapy resistance in AML is the Hedgehog (HH) signaling pathway. It is deregulated in numerous cancer entities and inhibition of its downstream transcription factors GLI translates into anti-leukemic effects. One major regulator of GLI is BRD4, a BET family member with epigenetic functions. We investigated the effect of ZEN-3365, a novel BRD4 inhibitor, on AML cells in regard to the HH pathway. We show that ZEN-3365 alone or in combination with GANT-61 reduced GLI promoter activity, cell proliferation and colony formation in AML cell lines and primary cells. Our findings strongly support the evaluation of the BRD4 inhibitor ZEN-3365 as a new therapeutic option in AML.

A Role for the Bone Marrow Microenvironment in Drug Resistance of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease with a poor prognosis and remarkable resistance to chemotherapeutic agents. Understanding resistance mechanisms against currently available drugs helps to recognize the therapeutic obstacles. Various mechanisms of resistance to chemotherapy or targeted inhibitors have been described for AML cells, including a role for the bone marrow niche in both the initiation and persistence of the disease, and in drug resistance of the leukemic stem cell (LSC) population. The BM niche supports LSC survival through direct and indirect interactions among the stromal cells, hematopoietic stem/progenitor cells, and leukemic cells. Additionally, the BM niche mediates changes in metabolic and signal pathway activation due to the acquisition of new mutations or selection and expansion of a minor clone. This review briefly discusses the role of the BM microenvironment and metabolic pathways in resistance to therapy, as discovered through AML clinical studies or cell line and animal models.

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

Synergistic inhibitory effect of Smo inhibitor jervine and its combination with decitabine can target Hedgehog signaling pathway to inhibit myelodysplastic syndrome cell line

OBJECTIVE

Hypomethylating agents (HMAs) have been reported to target the Sonic Hedgehog (Shh) signaling pathway in myelodysplastic syndrome (MDS). However, the synergistic inhibitory effect of Smo inhibitor jervine and its combination with decitabine in MUTZ-1 cell lines remains lacking.

METHODS

We used a CCK-8 assay to detect the in-vitro proliferation rate of MUTZ-1 cell lines. Besides, the Annexin V-FITC/PI double staining flow cytometry was utilized to detect the apoptosis rate and cell cycle changes. The expression levels of mRNA were quantified by using qRT-PCR, and the western blot was employed to detect the expression of proteins.

RESULTS

We found that the single-agent jervine or decitabine can significantly inhibit the proliferation rate of MUTZ-1 cell lines, and this inhibitory effect is time-dependent and concentration-dependent. The combined intervention of the jervine and decitabine can more significantly inhibit cell proliferation, induce cell apoptosis, and block the G1 phase of the cell cycle. The combined intervention of the two drugs significantly reduced Smo and G1i-1 mRNA expression in MUTZ-1 cells. Furthermore, after combining both of the drug treatments, the proteins levels of Smo, G1i-1, PI3K, p-AKT, Bcl2, and Cyclin Dl were significantly downregulated, and Caspase-3 is upregulated, indicating that jervine with its combination of decitabine might be effective for controlling the proliferation, apoptosis, and cell cycle.

CONCLUSION

The Smo inhibitor jervine and its combination with decitabine have a synergistic effect on the proliferation, cell cycle, and apoptosis of MUTZ-1 cells, and its mechanism may be achieved by interfering with the Shh signaling pathway.

Inhibition of EZH2 by chidamide exerts antileukemia activity and increases chemosensitivity through Smo/Gli-1 pathway in acute myeloid leukemia

Background

Epigenetic dysregulation plays important roles in leukemogenesis and the progression of acute myeloid leukemia (AML). Histone acetyltransferases (HATs) and histone deacetylases (HDACs) reciprocally regulate the acetylation and deacetylation of nuclear histones. Aberrant activation of HDACs results in uncontrolled proliferation and blockade of differentiation, and HDAC inhibition has been investigated as epigenetic therapeutic strategy against AML.

Methods

Cell growth was assessed with CCK-8 assay, and apoptosis was evaluated by flow cytometry in AML cell lines and CD45 + and CD34 + CD38- cells from patient samples after staining with Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI). EZH2 was silenced with short hairpin RNA (shRNA) or overexpressed by lentiviral transfection. Changes in signaling pathways were detected by western blotting. The effect of chidamide or EZH2-specific shRNA (shEZH2) in combination with adriamycin was studied in vivo in leukemia-bearing nude mouse models.

Results

In this study, we investigated the antileukemia effects of HDAC inhibitor chidamide and its combinatorial activity with cytotoxic agent adriamycin in AML cells. We demonstrated that chidamide suppressed the levels of EZH2, H3K27me3 and DNMT3A, exerted potential antileukemia activity and increased the sensitivity to adriamycin through disruption of Smo/Gli-1 pathway and downstream signaling target p-AKT in AML cells and stem/progenitor cells. In addition to decreasing the levels of H3K27me3 and DNMT3A, inhibition of EZH2 either pharmacologically by chidamide or genetically by shEZH2 suppressed the activity of Smo/Gli-1 pathway and increased the antileukemia activity of adriamycin against AML in vitro and in vivo.

Conclusions

Inhibition of EZH2 by chidamide has antileukemia activity and increases the chemosensitivity to adriamycin through Smo/Gli-1 pathway in AML cells (Fig. 5). These findings support the rational combination of HDAC inhibitors and chemotherapy for the treatment of AML.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02789-3.

The application effect analysis of personalized health education in acute leukemia nursing

OBJECTIVE

To analyze the effectiveness of personalized health education care in the nursing of patients with acute leukemia.

METHODS

A total of 108 patients with leukemia who were admitted to our hospital were randomly selected as research subjects. A random number table was used to allocate the patients into the observation group and the control group, with 54 patients in each group. The control group had routine health education care and the observation group received personalized health education care in addition to treatment given to the control group. The knowledge of leukemia, bad moods, adverse reaction and nursing satisfaction were compared between the two groups.

RESULTS

The observation group had better knowledge of leukemia and nursing satisfaction than the control group, and the incidence of bad moods (anxiety, depression) and adverse reactions were lower than that in the control group (all P<0.05).

CONCLUSION

The application of personalized health education in the nursing of acute leukemia patients was significant, which improved the knowledge of acute leukemia, reduced the incidence of bad moods and adverse reactions, and improved nursing satisfaction.

Glasdegib in combination with low-dose Cytarabine for the outpatient treatment of relapsed or refractory acute myeloid leukemia in unfit patients

We retrospectively collected clinical data on 31 relapsed or refractory acute myeloid leukemia (R/R AML) patients who were treated with outpatient glasdegib and low-dose Cytarabine (LDAraC) at our institution. The median age was 67 years (45–86). The median Eastern Cooperative Oncology Group performance status was 2 (1–3). The patients had previously received a median number of 2 (1–4) treatment lines, 61% (19/31) had been treated with intensive chemotherapy, 29% (9/31) had relapsed after allogeneic stem cell transplantation, and 45% (14/31) had had venetoclax exposure. Adverse cytogenetics were identified in 45% (14/31) of the cases. The CR + CRp rate was 21% (6/29) among evaluable patients. The median overall survival was 3.9 months for all patients. Different median overall survival times were observed in responders, patients achieving stable disease and those diagnosed with progressive disease: not reached vs 3.9 months vs 0.8 months, respectively (p < 0.001). The most common adverse events were pneumonia (29%, 9/31), sepsis (23%, 7/31), and febrile neutropenia (16%, 5/31). Glasdegib + LDAraC is a fairly safe, non-intensive, outpatient regimen inducing complete remission and resulting in prolonged survival in some R/R AML patients.

Post-Transplant Maintenance Therapy for Patients with Acute Myeloid Leukemia: Current Approaches and the Need for More Trials

Relapse rates following allogeneic stem cell transplantation for acute myeloid leukemia remain unacceptably high and a major cause of death. Maintenance therapies post-transplant administered either to patients with impending relapse or at high risk of relapse could present a strategy to improve survival and overall outcomes. With the increasing use of molecular and genomic characterization of the disease, more novel therapies became available as maintenance strategies. These options were, however, hindered by excessive toxicities, mostly hematologic, especially with the use of myeloablative conditioning regimens. Several key questions have also emerged including the efficacy of these therapies, the duration of maintenance, as well as the potential modulation of the graft and the immune microenvironment. These issues are further complicated by the paucity of well-designed prospective randomized clinical trials evaluating these agents. Future directions in this field should include better risk stratification and patient selection based on assays of minimal residual disease, as well as the incorporation of novel targets and pathways of leukemogenesis. In this article, we highlight the current evidence behind the use of post-transplant maintenance therapy, the optimal patient and disease selection, as well as the challenges faced by these strategies in an area that remains quite controversial. We will focus on therapies targeting leukemia stem cells that directly or indirectly modulate the allografted immune microenvironment and augment the graft-versus-leukemia impact.

Natural small molecule triptonide inhibits lethal acute myeloid leukemia with FLT3-ITD mutation by targeting Hedgehog/FLT3 signaling

Acute myeloid leukemia harboring internal tandem duplication of FMS-like tyrosine kinase 3 (FLT3-ITD AML) is a subset of highly aggressive malignancies with poor clinical outcome. Despite some advances in the development of FLT3 tyrosine kinase inhibitors (FLT3 inhibitors), most of FLT3-ITD AML patients suffer from lethal disease relapse, suggesting the requirement of novel targets and agents. Here we describe a natural small molecule, triptonide that can efficiently inhibit FLT3-ITD-driven AML in vitro and in vivo. Mechanistically, triptonide targeted Hedgehog/FLT3 signaling by inhibiting its critical effectors, which are GLI2, c-Myc and FLT3 and induced apoptosis of FLT3-ITD-driven leukemia cells. In addition, we also observed that triptonide activated tumor suppressor p53. In vivo, triptonide treatment markedly suppressed lethal FLT3-ITD-driven AML with good tolerance and prolonged survival time in orthotopic mouse model. Our studies identify Hedgehog/FLT3 axis as a novel target for treating FLT3-ITD-driven leukemia and demonstrate that triptonide is an active lead compound that can kill FLT3-ITD-driven leukemia cells.

Targeting multiple signaling pathways: the new approach to acute myeloid leukemia therapy

Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults and the second most common form of acute leukemia in children. Despite this, very little improvement in survival rates has been achieved over the past few decades. This is partially due to the heterogeneity of AML and the need for more targeted therapeutics than the traditional cytotoxic chemotherapies that have been a mainstay in therapy for the past 50 years. In the past 20 years, research has been diversifying the approach to treating AML by investigating molecular pathways uniquely relevant to AML cell proliferation and survival. Here we review the development of novel therapeutics in targeting apoptosis, receptor tyrosine kinase (RTK) signaling, hedgehog (HH) pathway, mitochondrial function, DNA repair, and c-Myc signaling. There has been an impressive effort into better understanding the diversity of AML cell characteristics and here we highlight important preclinical studies that have supported therapeutic development and continue to promote new ways to target AML cells. In addition, we describe clinical investigations that have led to FDA approval of new targeted AML therapies and ongoing clinical trials of novel therapies targeting AML survival pathways. We also describe the complexity of targeting leukemia stem cells (LSCs) as an approach to addressing relapse and remission in AML and targetable pathways that are unique to LSC survival. This comprehensive review details what we currently understand about the signaling pathways that support AML cell survival and the exceptional ways in which we disrupt them.

Acute Myeloid Leukemia: From Biology to Clinical Practices Through Development and Pre-Clinical Therapeutics

Recent studies have provided several insights into acute myeloid leukemia. Studies based on molecular biology have identified eight functional mutations involved in leukemogenesis, including driver and passenger mutations. Insight into Leukemia stem cells (LSCs) and assessment of cell surface markers have enabled characterization of LSCs from hematopoietic stem and progenitor cells. Clonal evolution has been described as having an effect similar to that of microenvironment alterations. Such biological findings have enabled the development of new targeted drugs, including drug inhibitors and monoclonal antibodies with blockage functions. Some recently approved targeted drugs have resulted in new therapeutic strategies that enhance standard intensive chemotherapy regimens as well as supportive care regimens. Besides the progress made in adoptive immunotherapy, since allogenic hematopoietic stem cell transplantation enabled the development of new T-cell transfer therapies, such as chimeric antigen receptor T-cell and transgenic TCR T-cell engineering, new promising strategies that are investigated.

Novel agents targeting leukemia cells and immune microenvironment for prevention and treatment of relapse of acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation

Relapse remains the worst life-threatening complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with acute myeloid leukemia (AML), whose prognosis has been historically dismal. Given the rapid development of genomics and immunotherapies, the interference strategies for AML recurrence have been changing these years. More and more novel targeting agents that have received the U.S. Food and Drug Administration (FDA) approval for de novo AML treatment have been administrated in the salvage or maintenance therapy of post-HSCT relapse. Targeted strategies that regulate the immune microenvironment of and optimize the graft versus leukemia (GVL) effect of immune cells are gradually improved. Such agents not only have been proven to achieve clinical benefits from a single drug, but if combined with classic therapies, can significantly improve the poor prognosis of AML patients who relapse after allo-HSCT. This review will focus on currently available and promising upcoming agents and also discuss the challenges and limitations of targeted therapies in the allogeneic hematopoietic stem cell transplantation community.

The Role of Smoothened in Cancer

Smoothened (SMO) belongs to the Hedgehog (HH) signaling pathway, which regulates cell growth, migration, invasion and stem cells in cancer. The HH signaling pathway includes both canonical and noncanonical pathways. The canonical HH pathway functions through major HH molecules such as HH ligands, PTCH, SMO and GLI, whereas the noncanonical HH pathway involves the activation of SMO or GLI through other pathways. The role of SMO has been discussed in different types of cancer, including breast, liver, pancreatic and colon cancers. SMO expression correlates with tumor size, invasiveness, metastasis and recurrence. In addition, SMO inhibitors can suppress cancer formation, reduce the proliferation of cancer cells, trigger apoptosis and suppress cancer stem cell activity. A better understanding of the role of SMO in cancer could contribute to the development of novel therapeutic approaches.

New agents in acute myeloid leukemia (AML)

Despite expanding knowledge in the molecular landscape of acute myeloid leukemia (AML) and an increasing understanding of leukemogenic pathways, little has changed in the treatment of AML in the last 40 years. Since introduction in the 1970s, combination chemotherapy consisting of anthracycline and cytarabine has been the mainstay of treatment, with major therapeutic advances based on improving supportive care rather than the introduction of novel therapeutics. Over the last decades, there have been extensive efforts to identify specific target mutations or pathways with the aim of improving clinical outcomes. Finally, after a prolonged wait, we are witnessing the next wave of AML treatment, characterized by a more “precise” and “personalized” understanding of the unique molecular or genetic mapping of individual patients. This new trend has since been further facilitated, with four new FDA approvals granted in 2017 in AML therapeutics. Currently, a total of eight targeted agents have been approved since 2017 (as of Jan. 2020). In this review, we will briefly discuss these newer agents in the context of their indication and the basis of their approval.

Cutting Edge Molecular Therapy for Acute Myeloid Leukemia

Recently, whole exome sequencing for acute myeloid leukemia (AML) has been performed by a next-generation sequencer in several studies. It has been revealed that a few gene mutations are identified per AML patient. Some of these mutations are actionable mutations that affect the response to an approved targeted treatment that is available for off-label treatment or that is available in clinical trials. The era of precision medicine for AML has arrived, and it is extremely important to detect actionable mutations relevant to treatment decision-making. However, the percentage of actionable mutations found in AML is about 50% at present, and therapeutic development is also needed for AML patients without actionable mutations. In contrast, the newly approved drugs are less toxic than conventional intensive chemotherapy and can be combined with low-intensity treatments. These combination therapies can contribute to the improvement of prognosis, especially in elderly AML patients who account for more than half of all AML patients. Thus, the treatment strategy for leukemia is changing drastically and showing rapid progress. In this review, we present the latest information regarding the recent development of treatment for AML.

＜Editors' Choice＞ How to improve outcomes of elderly patients with acute myeloid leukemia: era of excitement

Among elderly patients with acute myeloid leukemia (AML), especially those who are unfit for intensive chemotherapy, a policy of reduced-intensity chemotherapy or conservative observation has been chosen, resulting in unmet medical needs. Clinical trials using anticancer drugs including antimetabolites or drugs targeted to cell cycle-related molecules failed to show superiority over conventional treatments. Recently, drugs targeted to Bcl-2, SMO, FLT3, and IDH1/2 have been shown to prolong overall survival alone or in combination with reduced-intensity chemotherapy. These treatments are likely to reshape the therapeutic landscape of AML, which will be personalized for individual patients based on leukemia genetics.

Genetic biomarkers of drug resistance: A compass of prognosis and targeted therapy in acute myeloid leukemia

Acute myeloid leukemia (AML) is a highly aggressive hematological malignancy with complex heterogenous genetic and biological nature. Thus, prognostic prediction and targeted therapies might contribute to better chemotherapeutic response. However, the emergence of multidrug resistance (MDR) markedly impedes chemotherapeutic efficacy and dictates poor prognosis. Therefore, prior evaluation of chemoresistance is of great importance in therapeutic decision making and prognosis. In recent years, preclinical studies on chemoresistance have unveiled a compendium of underlying molecular basis, which facilitated the development of targetable small molecules. Furthermore, routing genomic sequencing has identified various genomic aberrations driving cellular response during the course of therapeutic treatment through adaptive mechanisms of drug resistance, some of which serve as prognostic biomarkers in risk stratification. However, the underlying mechanisms of MDR have challenged the certainty of the prognostic significance of some mutations. This review aims to provide a comprehensive understanding of the role of MDR in therapeutic decision making and prognostic prediction in AML. We present an updated genetic landscape of the predominant mechanisms of drug resistance with novel targeted therapies and potential prognostic biomarkers from preclinical and clinical chemoresistance studies in AML. We particularly highlight the unfolded protein response (UPR) that has emerged as a critical regulatory pathway in chemoresistance of AML with promising therapeutic horizon. Futhermore, we outline the most prevalent mutations associated with mechanisms of chemoresistance and delineate the future directions to improve the current prognostic tools. The molecular analysis of chemoresistance integrated with genetic profiling will facilitate decision making towards personalized prognostic prediction and enhanced therapeutic efficacy.

Aberrant TRPM4 expression in MLL-rearranged acute myeloid leukemia and its blockade induces cell cycle arrest via AKT/GLI1/Cyclin D1 pathway

Transient Receptor Potential Melastatin Subfamily Member 4 (TRPM4) has been demonstrated to be aberrantly expressed in several cancers but seldom reported in acute leukemia. Based on database mining and validated experiments, our present data show that TRPM4 is selectively overexpressed in AML patients and cell lines with the MLL gene rearrangement. We analyzed the correlation between TRPM4 expression and clinical parameters in a validated cohort of AML patients. Increased TRPM4 expression was associated with significant leukocytosis (p = .028), M4/M5 subtype (p = .000), FLT3-ITD mutation (p = .034), MLL status (p = .007) and a higher risk stratification (p = .001). Knockdown of TRPM4 mediated by siRNA impaired proliferation and arrested the cell cycle at the G0/G1 phase in MLL-rearranged leukemia cells. We suggested that TRPM4 may be involved in the pathogenesis of MLL-rearranged leukemia through regulating the AKT/GLI1/Cyclin D1 pathway. The transcription factor HOXA9 was found to be responsible for upregulation of TRPM4 expression by binding to its promoter. In conclusion, TRPM4 is overexpressed in MLL-rearranged AML and blockade of TRPM4 may be an alternative therapeutic approach in AML patients with high TRPM4 expression.

The bone marrow stromal niche: a therapeutic target of hematological myeloid malignancies

Introduction: Myeloid malignancies are caused by uncontrolled proliferation of neoplastic cells and lack of mature hematopoietic cells. Beside intrinsic genetic and epigenetic alterations within the neoplastic population, abnormal function of the bone marrow stroma promotes the neoplastic process. To overcome the supportive action of the microenvironment, recent research focuses on the development of targeted therapies, inhibiting the interaction of malignant cells and niche cells.Areas covered: This review covers regulatory networks and potential druggable pathways within the hematopoietic stem cell niche. Recent insights into the cell-to-cell interactions in the bone marrow microenvironment are presented. We performed literature searches using PubMed Database from 2000 to the present.Expert opinion: Future therapy of myeloid malignancies must focus on targeted, personalized treatment addressing specific alterations within the malignant and the supporting niche cells. This includes treatments to overcome resistance mechanisms against chemotherapeutic agents mediated by supporting microenvironment. Novel techniques employing sequencing approaches, Crisp/Cas9, or transgenic mouse models are required to elucidate specific interactions between components of the bone marrow niche to identify new therapeutic targets.

Eupatilin regulates proliferation and cell cycle of cervical cancer by regulating hedgehog signalling pathway

Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is a natural active substance found in génépi group plants, and its pharmacological activities has been proven to be useful in the treatment of various cancers. However, whether eupatilin demonstrates anti-cancer activity in cervical cancer is still under evaluation. To clarify this, cancer cell lines and nude mouse model were used in this study. The results indicated that eupatilin could inhibit the occurrence of cervical cancer both in vivo and in vitro. Cervical cancer cell lines (C4-1, HeLa, Caski, and Siha) and Ect1/E6E7 cells were incubated with eupatilin (40μM) for 48 hours. Compared with the control group, the viability of cervical cancer cells decreased significantly, while the apoptotic cells increased significantly. Cell cycle analysis showed that eupatilin treatment of HeLa and Caski cells reduced the proliferation index. Eupatilin at 40 mg/kg also inhibited tumour growth in tumour-bearing mice. Interestingly, weakened hedgehog signalling was observed in cervical cancer cells and tumours from tumour-bearing mice after eupatilin treatment. Our results reveal the inhibitory effect of eupatilin on cervical cancer and shed new light on the molecular mechanism of its therapeutic effect. SIGNIFICANCE OF THE STUDY: Eupatilin inhibited proliferation via promoting apoptosis and cell cycle arrest in HeLa and Caski cervical cancer cell lines. In addition, nude mouse tumourigenicity assay proved that eupatilin can suppress tumour growth in vivo. Dramatically, these activities might be involved in hedgehog signal pathway.

Bone marrow oxidative stress and specific antioxidant signatures in myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal stem cell disorders with an inherent tendency for transformation in secondary acute myeloid leukemia. This study focused on the redox metabolism of bone marrow (BM) cells from 97 patients compared with 25 healthy controls. The level of reactive oxygen species (ROS) was quantified by flow cytometry in BM cell subsets as well as the expression level of 28 transcripts encoding for major enzymes involved in the antioxidant cellular response. Our results highlight increased ROS levels in BM nonlymphoid cells and especially in primitive CD34posCD38low progenitor cells. Moreover, we identified a specific antioxidant signature, dubbed "antioxidogram," for the different MDS subgroups or secondary acute myeloblastic leukemia (sAML). Our results suggest that progression from MDS toward sAML could be characterized by 3 successive molecular steps: (1) overexpression of enzymes reducing proteic disulfide bonds (MDS with <5% BM blasts [GLRX family]); (2) increased expression of enzymes detoxifying H2O2 (MDS with 5% to 19% BM blasts [PRDX and GPX families]); and finally (3) decreased expression of these enzymes in sAML. The antioxidant score (AO-Score) defined by logistic regression from the expression levels of transcripts made it possible to stage disease progression and, interestingly, this AO-Score was independent of the revised International Scoring System. Altogether, this study demonstrates that MDS and sAML present an important disturbance of redox metabolism, especially in BM stem and progenitor cells and that the specific molecular antioxidant response parameters (antioxidogram, AO-Score) could be considered as useful biomarkers for disease diagnosis and follow-up.