Lapatinib induces autophagic cell death and differentiation in acute myeloblastic leukemia

Identification and validation of a novel prognostic model based on anoikis‑related genes in acute myeloid leukemia

Acute myeloid leukemia (AML) is a hematological cancer prevalent worldwide. Anoikis-related genes (ARGs) are crucial in the progression of cancer and metastasis of tumors. However, their role in AML needs to be clarified. In the present study, differential analysis was performed on data from The Cancer Genome Atlas database to identify differentially expressed ARGs (DE-ARGs). Subsequently, a prognostic model for patients with AML was constructed using univariate Cox, Least Absolute Shrinkage and Selection Operator and multivariate Cox regression analyses. This model was based on four key DE-ARGs [lectin galactoside-binding soluble 1 (LGALS1), integrin subunit α 4 (ITGA4), hepatocyte growth factor (HGF) and Ras homolog gene family member C (RHOC)]. Independent prognostic factors for AML included prior treatment, age, risk scores and diagnosis. A nomogram was constructed based on these factors to aid clinical decision-making. Furthermore, bone marrow samples were collected from individuals diagnosed with AML and healthy donors to validate the expression of the identified ARGs using reverse transcription-quantitative PCR. The mRNA levels of LGALS1 and RHOC were significantly higher, while those of ITGA4 and HGF were significantly lower in patients with AML than in healthy donors (all P<0.05). The results of the present study expands the understanding of the function of ARGs in AML, providing a new theoretical basis for the treatment of AML.

Navigating therapeutic prospects by modulating autophagy in colorectal cancer

Colorectal cancer (CRC) remains a leading cause of death globally despite the improvements in cancer treatment. Autophagy is an evolutionarily conserved lysosomal-dependent degradation pathway that is critical in maintaining cellular homeostasis. However, in cancer, autophagy may have conflicting functions in preventing early tumour formation versus the maintenance of advanced-stage tumours. Defective autophagy has a broad and dynamic effect not just on cancer cells, but also on the tumour microenvironment which influences tumour progression and response to treatment. To add to the layer of complexity, somatic mutations in CRC including tumour protein p53 (TP53), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), Kirsten rat sarcoma viral oncogene homolog (KRAS), and phosphatase and tensin homolog (PTEN) can render chemoresistance by promoting a pro-survival advantage through autophagy. Recent studies have also reported autophagy-related cell deaths that are distinct from classical autophagy by employing parts of the autophagic machinery, which impacts strategies for autophagy regulation in cancer therapy. This review discusses the molecular processes of autophagy in the evolution of CRC and its role in the tumour microenvironment, as well as prospective therapeutic methods based on autophagy suppression or promotion. It also highlights clinical trials using autophagy modulators for treating CRC, underscoring the importance of autophagy regulation in CRC therapy.

Is Autophagy Targeting a Valid Adjuvant Strategy in Conjunction with Tyrosine Kinase Inhibitors?

Tyrosine kinase inhibitors (TKIs) represent a relatively large class of small-molecule inhibitors that compete with ATP for the catalytic binding site of tyrosine kinase proteins. While TKIs have demonstrated effectiveness in the treatment of multiple malignancies, including chronic myelogenous leukemia, gastrointestinal tumors, non-small cell lung cancers, and HER2-overexpressing breast cancers, as is almost always the case with anti-neoplastic agents, the development of resistance often imposes a limit on drug efficacy. One common survival response utilized by tumor cells to ensure their survival in response to different stressors, including anti-neoplastic drugs, is that of autophagy. The autophagic machinery in response to TKIs in multiple tumor models has largely been shown to be cytoprotective in nature, although there are a number of cases where autophagy has demonstrated a cytotoxic function. In this review, we provide an overview of the literature examining the role that autophagy plays in response to TKIs in different preclinical tumor model systems in an effort to determine whether autophagy suppression or modulation could be an effective adjuvant strategy to increase efficiency and/or overcome resistance to TKIs.

The Interplay between Autophagy and Mitochondria in Cancer

Besides producing cellular energy, mitochondria are crucial in controlling oxidative stress and modulating cellular metabolism, particularly under stressful conditions. A key aspect of this regulatory role involves the recycling process of autophagy, which helps to sustain energy homeostasis. Autophagy, a lysosome-dependent degradation pathway, plays a fundamental role in maintaining cellular homeostasis by degrading damaged organelles and misfolded proteins. In the context of tumor formation, autophagy significantly influences cancer metabolism and chemotherapy resistance, contributing to both tumor suppression and surveillance. This review focuses on the relationship between mitochondria and autophagy, specifically in the context of cancer progression. Investigating the interaction between autophagy and mitochondria reveals new possibilities for cancer treatments and may result in the development of more effective therapies targeting mitochondria, which could have significant implications for cancer treatment. Additionally, this review highlights the increasing understanding of autophagy's role in tumor development, with a focus on modulating mitochondrial function and autophagy in both pre-clinical and clinical cancer research. It also explores the potential for developing more-targeted and personalized therapies by investigating autophagy-related biomarkers.

Neratinib inhibits proliferation and promotes apoptosis of acute myeloid leukemia cells by activating autophagy-dependent ferroptosis

Acute myeloid leukemia (AML) is a hematologic malignancy with increased lethality. We focused on elucidating the role of Neratinib, a tyrosine kinase inhibitor, in the progression of AML and identify the potential mechanisms. Upon the treatment of Neratinib, autophagy suppressor 3-methyladenine (3-MA) and ferroptosis stimulator Erastin, the viability and proliferation of HL-60 cells were evaluated by cell counting kit-8 and 5-Ethynyl-20-Deoxyuridine staining assays. A flow cytometer was to observe cell cycle and apoptosis. Production of reactive oxygen species (ROS) was tested via 2,7-dichlorodihydrofluorescein diacetate  assay. Additionally, malondialdehyde (MDA) content and Fe²⁺ activity were examined with commercial kits. LC3-II expression was examined by using immunofluoresence staining. Western blot analysis ascertained the expression of proliferation, apoptosis, ferroptosis and autophagy-associated proteins. It was noted that Neratinib notably mitigated cell viability and proliferation, cut down Ki67 and proliferating cell nuclear antigen expression. Moreover, Neratinib hindered cell cycle at G0/G1 phase whereas exacerbated apoptosis. ROS, MDA and Fe²⁺ activities were elevated by Neratinib, coupled with the reduced glutathione peroxidase 4, ferritin heavy chain 1 expression and enhanced acyl-CoA synthetase long-chain family member 4 expression. Furthermore, Neratinib promoted autophagy of HL-60 cells, evidenced by raised LC3-II, ATG5, Beclin1 expression and lessened p62 expression. Importantly, 3-MA eased the impacts of Neratinib on cell ferroptosis, proliferation and apoptosis, which were offset by further administration of Erastin. To conclude, Neratinib could suppress proliferation and promote apoptosis of HL-60 cells through autophagy-dependent ferroptosis.

An Autophagy-related Long Non-coding RNA Signature for Breast Cancer

BACKGROUND

The most prevalent malignant tumor in women is breast cancer (BC). Autophagic therapies have been identified for their contribution in BC cell death. Therefore, the potential prognostic role of long non-coding RNA (lncRNA) related to autophagy in patients with BC was examined.

METHODS

The lncRNAs expression profiles were derived from The Cancer Genome Atlas (TCGA) database. Throughout univariate Cox regression and multivariate Cox regression test, lncRNA with BC prognosis have been differentially presented. We then defined the optimal cutoff point between high and low-risk groups. The receiver operating characteristic (ROC) curves were drawn to test this signature. In order to examine possible signaling mechanisms linked to these lncRNAs, the Gene Set Enrichment Analysis (GSEA) has been carried out.

RESULTS

Based on the lncRNA expression profiles for BC, a 9 lncRNA signature associated with autophagy was developed. The optimal cutoff value for high-risk and low-risk groups was used. The high-risk group had less survival time than the low-risk group. The result of this lncRNA signature was highly sensitive and precise. GSEA study found that the gene sets have been greatly enriched in many cancer pathways.

CONCLUSIONS

Our signature of 9 lncRNAs related to autophagy has prognostic value for BC, and these lncRNAs related to autophagy may play an important role in BC biology.

Selective ERBB2 and BCL2 Inhibition Is Synergistic for Mitochondrial-Mediated Apoptosis in MDS and AML Cells

The ERBB2 proto-oncogene is associated with an aggressive phenotype in breast cancer. Its role in hematologic malignancies is incompletely defined, in part because ERBB2 is not readily detected on the surface of cancer cells. We demonstrate that truncated ERBB2, which lacks the extracellular domain, is overexpressed on primary CD34⁺ myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) cells compared with healthy hematopoietic cells. This overexpression of ERBB2 is associated with aberrant, oncogenic signaling with autophosphorylation of multiple tyrosine sites. Like in breast cancers, ERBB2 can exist as truncated isoforms p95^ERBB2 and p110^ERBB2 in MDS and AML. Neutralization of ERBB2 signaling with ERBB2 tyrosine kinase inhibitors (i.e., lapatinib, afatinib, and neratinib) increases apoptotic cell death and reduces human engraftment of MDS cells in mice at 21 weeks posttransplantation. Inhibition of ERBB2 modulates the expression of multiple pro- and anti-apoptotic mitochondrial proteins, including B-cell lymphoma 2 (BCL2). Dual blockade with ERBB2 and BCL2 inhibitors triggers additional reductions of BCL2 phosphorylation and myeloid cell leukemia-1 (MCL1) expression compared with single drug treatment. Dual therapy was synergistic at all tested doses, with a dose reduction index of up to 29 for lapatinib + venetoclax compared with venetoclax alone. Notably, these agents operated together and shifted cancer cells to a pro-apoptotic phenotype, resulting in increased mitochondrial cytochrome c release and activated caspase-3-mediated cell death. IMPLICATIONS: These findings warrant study of ERBB2 and BCL2 combination therapy in patients with MDS and AML. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/19/5/886/F1.large.jpg.

Induction of Apoptosis in the U937 Cell Line Co-cultured with Adipose-derived Stem Cells Secreting Bone Morphogenetic Protein-4

Transforming growth factor-beta (TGF-β) plays a significant role in tumorigenesis. MiR-181b is a multifunctional miRNA involved in numerous cellular processes, such as cell fate and cell invasion. This study aimed to examine whether the co-culture of adipose-derived stem cells (ADSCs), highly expressing bone morphogenetic protein-4, with the U937 cell line, which is a human myeloid leukemia cell line, is able to induce cell death in this cancer cell line, considering the potential ability of ADSCs to migrate from tumor sites. Cell surface markers, namely CD73 and CD105, were analyzed to verify the identity of mesenchymal stem cells isolated from adipose tissue. Besides, the osteogenic and adipogenic differentiation potentials of ADSCs were evaluated. The induction of cell death and apoptosis in the U937 cell line was assessed using MTT and annexin V/ PI assays, respectively. The expression levels of miR-181 and TGF-β were determined in the co-culture system using real-time PCR. The results of MTT and annexin V/ PI assays showed that BMP4-expressing ADSCs could inhibit cell viability and induce apoptosis in U937 cells in the co-culture system. The co-culture of ADSCs, highly expressing BMP-4, with the U937 cell line led to the downregulation of miR-181 and TGF-β genes in the human cancer cell line. ADSCs may further be studied as a candidate for the treatment of hematological cancers.

Combination of carbon-ion beam and dual tyrosine kinase inhibitor, lapatinib, effectively destroys HER2 positive breast cancer stem-like cells

To investigate whether carbon-ion beam alone, or in combination with lapatinib, has a beneficial effect in targeting HER2-positive breast cancer stem-like cells (CSCs) compared to that of X-rays, human breast CSCs derived from BT474 and SKBR3 cell lines were treated with a carbon-ion beam or X-rays irradiation alone or in combination with lapatinib, and then cell viability, spheroid formation assays, apoptotic analyses, gene expression analysis of related genes, and immunofluorescent γ-H2AX foci assays were performed. Spheroid formation assays confirmed that ESA+/CD24- cells have CSC properties compared to ESA-/CD24+ cells. CSCs were more highly enriched after X-ray irradiation combined with lapatinib, whereas carbon-ion beam combined with lapatinib significantly decreased the proportion of CSCs. Carbon-ion beam combined with lapatinib significantly suppressed spheroid formation compared to X-rays combined with lapatinib or carbon ion beam alone. Cell cycle analysis showed that carbon ion beam combined with lapatinib predominantly enhanced sub-G1 and G2/M arrested population compared to that of carbon-ion beam, X-ray treatments alone. Carbon-ion beam combined with lapatinib significantly enhanced apoptosis and carbon-ion beam alone dose-dependently increased autophagy-related expression of Beclin1 and in combination with lapatinib greatly enhanced ATG7 expression at protein levels. In addition, a large-sized γH2AX foci in CSCs were induced by carbon ion beam combined with lapatinib treatment in CSCs compared to cells receiving X-rays or carbon-ion beam alone. Altogether, combination of carbon-ion beam irradiation and lapatinib has a high potential to kill HER2-positive breast CSCs, causing severe irreparable DNA damage, enhanced autophagy, and apoptosis.

Targeting Autophagy for Cancer Treatment and Tumor Chemosensitization

Autophagy is a tightly regulated catabolic process that facilitates nutrient recycling from damaged organelles and other cellular components through lysosomal degradation. Deregulation of this process has been associated with the development of several pathophysiological processes, such as cancer and neurodegenerative diseases. In cancer, autophagy has opposing roles, being either cytoprotective or cytotoxic. Thus, deciphering the role of autophagy in each tumor context is crucial. Moreover, autophagy has been shown to contribute to chemoresistance in some patients. In this regard, autophagy modulation has recently emerged as a promising therapeutic strategy for the treatment and chemosensitization of tumors, and has already demonstrated positive clinical results in patients. In this review, the dual role of autophagy during carcinogenesis is discussed and current therapeutic strategies aimed at targeting autophagy for the treatment of cancer, both under preclinical and clinical development, are presented. The use of autophagy modulators in combination therapies, in order to overcome drug resistance during cancer treatment, is also discussed as well as the potential challenges and limitations for the use of these novel therapeutic strategies in the clinic.

Blast vacuolization in AML patients indicates adverse-risk AML and is associated with impaired survival after intensive induction chemotherapy

Introduction

Vacuolization is a frequently found morphological feature in acute myeloid leukemia (AML) blasts. Subcellular origin and biological function as well as prognostic impact are currently unknown. The aim of this study was to evaluate whether vacuolization correlates with clinically relevant AML features.

Materials & methods

Bone marrow smears of patients diagnosed with AML at the University Hospital Frankfurt between January 2011 and August 2013 were analyzed for blast vacuolization and correlated with clinically relevant AML features. Patients undergoing standard induction chemotherapy were further analyzed for molecular and cytogenetic features as well as treatment response and survival.

Results

14 of 100 patients diagnosed with AML receiving standard induction chemotherapy had evidence of blast vacuolization. Positivity for vacuolization correlated with a CD15 positive immunophenotype and with a higher incidence of high-risk AML according to the European LeukemiaNet risk stratification. AML patients with blast vacuolization had a poor blast clearance after standard induction chemotherapy and poor survival.

Discussion

In conclusion, our findings demonstrate that vacuolization can easily be determined in myeloid leukemia blasts and may be a useful biomarker to predict AML risk groups as well as early treatment response rates and survival.

Induction of Autophagic Death of Human Hepatocellular Carcinoma Cells by Armillaridin from Armillaria mellea

The honey mushroom, Armillaria mellea, is known to have medicinal qualities and has been used in recent years as a health food and dietary supplement worldwide. In Asia, it is commonly consumed as an herbal medicine, being a key component of the Chinese preparation “Tien-ma”. Here, we examined the antitumor effects of armillaridin, a bioactive compound isolated from A. mellea, on human hepatocellular carcinoma (HCC) cells. Armillaridin inhibited the growth of human Huh7, HepG2, and HA22T HCC cells, and its cytotoxicity was confirmed by observations of its induction of mitochondrial transmembrane potential collapse. However, armillaridin treatment did not result in large numbers of cells with fragmented chromosomal DNA, suggesting that apoptosis was not responsible for these effects. We therefore tested for signs of autophagic cell death following armillaridin administration. Armillaridin induced LC3 aggregation in green fluorescent protein-LC3-overexpressing cells. Moreover, flow cytometry and immunoblotting revealed that it increased the number of acridine orange-positive cells and upregulated autophagy-related proteins, respectively. Furthermore, armillaridin cytotoxicity was suppressed by the autophagy inhibitor 3-methyladenine. In summary, our results indicated that armillaridin induces HCC cell death by autophagy, and demonstrated the potential of armillaridin as an antihepatoma agent.

Autophagy-dependent cell death – where, how and why a cell eats itself to death

Autophagy as a means of cell killing was first advanced by Clark's phenotypic description of ‘Type II autophagic cell death’ in 1990. However, this phenomenon later came into question, because the presence of autophagosomes in dying cells does not necessarily signify that autophagy is the cause of demise, but rather may reflect the efforts of the cell to prevent it. Resolution of this issue comes from a more careful definition of autophagy-dependent cell death (ADCD) as a regulated cell death that is shown experimentally to require different components of the autophagy machinery without involvement of alternative cell death pathways. Following these strict criteria, ADCD has been validated in both lower model organisms and mammalian cells, highlighting its importance for developmental and pathophysiological cell death. Recently, researchers have defined additional morphological criteria that characterize ADCD and begun to explore how the established, well-studied autophagy pathway is subverted from a survival to a death function. This Review explores validated models of ADCD and focuses on the current understanding of the mechanisms by which autophagy can kill a cell.

Circular RNA GRB10 as a competitive endogenous RNA regulating nucleus pulposus cells death in degenerative intervertebral disk

Intervertebral disc degeneration (IDD) is an important factor leading to low back pain, but the underlying mechanisms remain poorly understood. Compared with normal nucleus pulposus (NP) tissues, the expression of circ-GRB10 was downregulated in IDD. Furthermore, overexpression of circ-GRB10 inhibited NP cell apoptosis. circ-GRB10 could sequester miR-328-5p, which could potentially lead to the upregulation of target genes related to cell proliferation via the ErbB pathway. In conclusion, the present study revealed that circ-GRB10/miR-328-5p/ERBB2 signaling pathway is involved in IDD development, suggesting that circ-GRB10 might be a novel therapeutic target for IDD.

Cell death-based treatment of lung adenocarcinoma

The most common type of lung cancer is adenocarcinoma (ADC), comprising around 40% of all lung cancer cases. In spite of achievements in understanding the pathogenesis of this disease and the development of new approaches in its treatment, unfortunately, lung ADC is still one of the most aggressive and rapidly fatal tumor types with overall survival less than 5 years. Lung ADC is often diagnosed at advanced stages involving disseminated metastatic tumors. This is particularly important for the successful development of new approaches in cancer therapy. The high resistance of lung ADC to conventional radiotherapies and chemotherapies represents a major challenge for treatment effectiveness. Here we discuss recent advances in understanding the molecular pathways driving tumor progression and related targeted therapies in lung ADCs. In addition, the cell death mechanisms induced by different treatment strategies and their contribution to therapy resistance are analyzed. The focus is on approaches to overcoming drug resistance in order to improve future treatment decisions.

Effects of lapatinib on cell proliferation and apoptosis in NB4 cells

Acute promyelocytic leukemia (APL), characterized by the presence of the promyelocytic leukemia (PML)-retinoic acid α receptor (RARα) fusion protein, responds to treatment with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). However, drug resistance and side effects restrict the application of these reagents. Hence, the development of novel therapeutic drugs for APL treatment is critical. Lapatinib, a small-molecule tyrosine kinase inhibitor, has been used in the treatment of different tumors. However, it is unclear whether lapatinib exerts antitumor effects on APL. The present study investigated the antitumor effects and potential mechanisms of lapatinib on NB4 cells derived from APL. Cell Counting Kit-8 assay and colony forming analysis indicated that lapatinib inhibited NB4 cell proliferation in a dose-dependent manner. Flow cytometry analysis revealed that lapatinib induced cell cycle arrest at the S phase and promoted cell apoptosis. Furthermore, Liu's staining and Hoechst 33258 staining revelaed that lapatinib treatment induced an apoptotic nuclear phenomenon. Furthermore, lapatinib induced apoptosis by decreasing Bcl-2 and PML-RARα levels, and by increasing the levels of Bax, cleaved PARP, cleaved caspase-3 and cleaved caspase-9. In addition, lapatinib increased the levels of phospho-p38 MAPK and phospho-JNK, and decreased the levels of phospho-Akt. The p38 inhibitor PD169316 partially blocked lapatinib-induced proliferation inhibition and apoptosis, whereas the JNK inhibitor SP600125 had no such effects. Therefore, treatment with lapatinib may be a promising strategy for APL therapy.

EGFR Family Members' Regulation of Autophagy Is at a Crossroads of Cell Survival and Death in Cancer

The epidermal growth factor receptor (EGFR) signaling pathways are altered in many cancers contributing to increased cell survival. These alterations are caused mainly through increased expression or mutation of EGFR family members EGFR, ErbB2, ErbB3, and ErbB4. These receptors have been successfully targeted for cancer therapy. Specifically, a monoclonal antibody against ErbB2, trastuzumab, and a tyrosine kinase inhibitor against EGFR, gefitinib, have improved the survival of breast and lung cancer patients. Unfortunately, cancer patients frequently become resistant to these inhibitors. This has led to investigating how EGFR can contribute to cell survival and how cancer cells can overcome inhibition of its signaling. Indeed, it is coming into focus that EGFR signaling goes beyond a single signal triggering cell proliferation and survival and is a sensor that regulates the cell’s response to microenvironmental stresses such as hypoxia. It acts as a switch that modulates the ability of cancer cells to survive. Autophagy is a process of self-digestion that is inhibited by EGFR allowing cancer cells to survive under stresses that would normally cause death and become resistant to chemotherapy. Inhibiting EGFR signaling allows autophagy to contribute to cell death. This gives new opportunities to develop novel therapeutic strategies to treat cancers that rely on EGFR signaling networks and autophagy. In this review, we summarize the current understanding of EGFR family member regulation of autophagy in cancer cells and how new therapeutic strategies could be developed to overcome drug resistance.