Targeting EGFR-mediated autophagy as a potential strategy for cancer therapy

Enhancing Therapeutic Efficacy in Cancer Treatment: Integrating Nanomedicine with Autophagy Inhibition Strategies

The complicated stepwise lysosomal degradation process known as autophagy is in charge of destroying and eliminating damaged organelles and defective cytoplasmic components. This mechanism promotes metabolic adaptability and nutrition recycling. Autophagy functions as a quality control mechanism in cells that support homeostasis and redox balance under normal circumstances. However, the role of autophagy in cancer is controversial because, mostly depending on the stage of the tumor, it may either suppress or support the disease. While autophagy delays the onset of tumors and slows the dissemination of cancer in the early stages of tumorigenesis, numerous studies demonstrate that autophagy promotes the development and spread of tumors as well as the evolution and development of resistance to several anticancer drugs in advanced cancer stages. In this Review, we primarily emphasize the therapeutic role of autophagy inhibition in improving the treatment of multiple cancers and give a broad overview of how its inhibition modulates cancer responses. There have been various attempts to inhibit autophagy, including the use of autophagy inhibitor drugs, gene silencing therapy (RNA interference), and nanoparticles. In this Review, all these topics are thoroughly covered and illustrated by recent studies and field investigations.

A specific super-enhancer actuated by berberine regulates EGFR-mediated RAS-RAF1-MEK1/2-ERK1/2 pathway to induce nasopharyngeal carcinoma autophagy

Nasopharyngeal carcinoma (NPC), primarily found in the southern region of China, is a malignant tumor known for its highly metastatic characteristics. The high mortality rates caused by the distant metastasis and disease recurrence remain unsolved clinical problems. In clinic, the berberine (BBR) compound has widely been in NPC therapy to decrease metastasis and disease recurrence, and BBR was documented as a main component with multiple anti-NPC effects. However, the mechanism by which BBR inhibits the growth and metastasis of nasopharyngeal carcinoma remains elusive. Herein, we show that BBR effectively inhibits the growth, metastasis, and invasion of NPC via inducing a specific super enhancer (SE). From a mechanistic perspective, the RNA sequencing (RNA-seq) results suggest that the RAS-RAF1-MEK1/2-ERK1/2 signaling pathway, activated by the epidermal growth factor receptor (EGFR), plays a significant role in BBR-induced autophagy in NPC. Blockading of autophagy markedly attenuated the effect of BBR-mediated NPC cell growth and metastasis inhibition. Notably, BBR increased the expression of EGFR by transcription, and knockout of EGFR significantly inhibited BBR-induced microtubule associated protein 1 light chain 3 (LC3)-II increase and p62 inhibition, proposing that EGFR plays a pivotal role in BBR-induced autophagy in NPC. Chromatin immunoprecipitation sequencing (ChIP-seq) results found that a specific SE existed only in NPC cells treated with BBR. This SE knockdown markedly repressed the expression of EGFR and phosphorylated EGFR (EGFR-p) and reversed the inhibition of BBR on NPC proliferation, metastasis, and invasion. Furthermore, BBR-specific SE may trigger autophagy by enhancing EGFR gene transcription, thereby upregulating the RAS-RAF1-MEK1/2-ERK1/2 signaling pathway. In addition, in vivo BBR effectively inhibited NPC cells growth and metastasis, following an increase LC3 and EGFR and a decrease p62. Collectively, this study identifies a novel BBR-special SE and established a new epigenetic paradigm, by which BBR regulates autophagy, inhibits proliferation, metastasis, and invasion. It provides a rationale for BBR application as the treatment regime in NPC therapy in future.

Combination of betulinic acid and EGFR-TKIs exerts synergistic anti-tumor effects against wild-type EGFR NSCLC by inducing autophagy-related cell death via EGFR signaling pathway

BACKGROUND

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of lung cancer patients with mutated EGFR. However, the efficacy of EGFR-TKIs in wild-type EGFR tumors has been shown to be marginal. Methods that can sensitize EGFR-TKIs to EGFR wild-type NSCLC remain rare. Hence, we determined whether combination treatment can maximize the therapeutic efficacy of EGFR-TKIs.

METHODS

We established a focused drug screening system to investigate candidates for overcoming the intrinsic resistance of wild-type EGFR NSCLC to EGFR-TKIs. Molecular docking assays and western blotting were used to identify the binding mode and blocking effect of the candidate compounds. Proliferation assays, analyses of drug interactions, colony formation assays, flow cytometry and nude mice xenograft models were used to determine the effects and investigate the molecular mechanism of the combination treatment.

RESULTS

Betulinic acid (BA) is effective at targeting EGFR and synergizes with EGFR-TKIs (gefitinib and osimertinib) preferentially against wild-type EGFR. BA showed inhibitory activity due to its interaction with the ATP-binding pocket of EGFR and dramatically enhanced the suppressive effects of EGFR-TKIs by blocking EGFR and modulating the EGFR-ATK-mTOR axis. Mechanistic studies revealed that the combination strategy activated EGFR-induced autophagic cell death and that the EGFR-AKT-mTOR signaling pathway was essential for completing autophagy and cell cycle arrest. Activation of the mTOR pathway or blockade of autophagy by specific chemical agents markedly attenuated the effect of cell cycle arrest. In vivo administration of the combination treatment caused marked tumor regression in the A549 xenografts.

CONCLUSIONS

BA is a potential wild-type EGFR inhibitor that plays a critical role in sensitizing EGFR-TKI activity. BA combined with an EGFR-TKI effectively suppressed the proliferation and survival of intrinsically resistant lung cancer cells via the inhibition of EGFR as well as the induction of autophagy-related cell death, indicating that BA combined with an EGFR-TKI may be a potential therapeutic strategy for overcoming the primary resistance of wild-type EGFR-positive lung cancers.

Impact of Complex Apoptotic Signaling Pathways on Cancer Cell Sensitivity to Therapy

Anticancer drugs induce apoptotic and non-apoptotic cell death in various cancer types. The signaling pathways for anticancer drug-induced apoptotic cell death have been shown to differ between drug-sensitive and drug-resistant cells. In atypical multidrug-resistant leukemia cells, the c-Jun/activator protein 1 (AP-1)/p53 signaling pathway leading to apoptotic death is altered. Cancer cells treated with anticancer drugs undergo c-Jun/AP-1-mediated apoptotic death and are involved in c-Jun N-terminal kinase activation and growth arrest- and DNA damage-inducible gene 153 (Gadd153)/CCAAT/enhancer-binding protein homologous protein pathway induction, regardless of the p53 genotype. Gadd153 induction is associated with mitochondrial membrane permeabilization after anticancer drug treatment and involves a coupled endoplasmic reticulum stress response. The induction of apoptosis by anticancer drugs is mediated by the intrinsic pathway (cytochrome c, Cyt c) and subsequent activation of the caspase cascade via proapoptotic genes (e.g., Bax and Bcl-xS) and their interactions. Anticancer drug-induced apoptosis involves caspase-dependent and caspase-independent pathways and occurs via intrinsic and extrinsic pathways. The targeting of antiapoptotic genes such as Bcl-2 enhances anticancer drug efficacy. The modulation of apoptotic signaling by Bcl-xS transduction increases the sensitivity of multidrug resistance-related protein-overexpressing epidermoid carcinoma cells to anticancer drugs. The significance of autophagy in cancer therapy remains to be elucidated. In this review, we summarize current knowledge of cancer cell death-related signaling pathways and their alterations during anticancer drug treatment and discuss potential strategies to enhance treatment efficacy.

Targeted EGFR Nanotherapy in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality worldwide. Despite advances in treatment, the prognosis remains poor, highlighting the need for novel therapeutic strategies. The present review explores the potential of targeted epidermal growth factor receptor (EGFR) nanotherapy as an alternative treatment for NSCLC, showing that EGFR-targeted nanoparticles are efficiently taken up by NSCLC cells, leading to a significant reduction in tumor growth in mouse models. Consequently, we suggest that targeted EGFR nanotherapy could be an innovative treatment strategy for NSCLC; however, further studies are needed to optimize the nanoparticles and evaluate their safety and efficacy in clinical settings and human trials.

EGFR-T790M Mutation-Derived Interactome Rerouted EGFR Translocation Contributing to Gefitinib Resistance in Non-Small Cell Lung Cancer

Secondary mutation, T790M, conferring tyrosine kinase inhibitors (TKIs) resistance beyond oncogenic epidermal growth factor receptor (EGFR) mutations presents a challenging unmet need. Although TKI-resistant mechanisms are intensively investigated, the underlying responses of cancer cells adapting drug perturbation are largely unknown. To illuminate the molecular basis linking acquired mutation to TKI resistance, affinity purification coupled mass spectrometry was adopted to dissect EGFR interactome in TKI-sensitive and TKI-resistant non-small cell lung cancer cells. The analysis revealed TKI-resistant EGFR-mutant interactome allocated in diverse subcellular distribution and enriched in endocytic trafficking, in which gefitinib intervention activated autophagy-mediated EGFR degradation and thus autophagy inhibition elevated gefitinib susceptibility. Alternatively, gefitinib prompted TKI-sensitive EGFR translocating toward cell periphery through Rab7 ubiquitination which may favor efficacy to TKIs suppression. This study revealed that T790M mutation rewired EGFR interactome that guided EGFR to autophagy-mediated degradation to escape treatment, suggesting that combination therapy with TKI and autophagy inhibitor may overcome acquired resistance in non-small cell lung cancer.

Midazolam impedes lung carcinoma cell proliferation and migration via EGFR/MEK/ERK signaling pathway

Non-small-cell lung cancer (NSCLC) is a dominating type of lung cancer with high morbidity and mortality. Midazolam has been reported to promote cell apoptosis in NSCLC, but the molecular mechanism of midazolam remains to be further explored. In the current work, cell viability, proliferation, migration, and apoptosis rates of NSCLC cells treated with midazolam were measured using cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine (EdU) and colony formation assays, transwell, and flow cytometry assay, respectively, to evaluate the malignant behaviors. Western blot was applied to access EGFR/MEK/ERK pathway-related protein levels. The results demonstrated midazolam significantly declined the viability of NSCLC cells. Furthermore, midazolam restrained cell proliferation and migration and contributed to cell apoptosis in NSCLC. Midazolam exerted suppressive function to EGFR pathway during NSCLC development. Moreover, the activation of EGFR/MEK/ERK pathway abrogated the effects of midazolam on NSCLC cell proliferation, apoptosis, and migration. Taken together, midazolam exhibited anti-tumor effects hallmarked by EGFR pathway inhibition, providing a novel insight into the treatment of NSCLC.

Synthesis and Biological Properties of EGFR-Targeted Photosensitizer Based on Cationic Porphyrin

Photodynamic therapy (PDT) in oncology is characterized by low invasiveness, minimal side effects, and little tissue scarring. Increasing the selectivity of PDT agents toward a cellular target is a new approach intended to improve this method. This study is devoted to the design and synthesis of a new conjugate based on meso-arylporphyrin with a low-molecular-weight tyrosine kinase inhibitor, Erlotinib. A nano-formulation based on Pluronic F127 micelles was obtained and characterized. The photophysical and photochemical properties and biological activity of the studied compounds and their nano-formulation were studied. A significant, 20-40-fold difference between the dark and photoinduced activity was achieved for the conjugate nanomicelles. After irradiation, the studied conjugate nanomicelles were 1.8 times more toxic toward the EGFR-overexpressing cell line MDA-MB-231 compared to the conditionally normal NKE cells. The IC50 was 0.073 ± 0.014 μM for the MDA-MB-231 cell line and 0.13 ± 0.018 μM for NKE cells after irradiation for the target conjugate nanomicelles.

Histopathology images predict multi-omics aberrations and prognoses in colorectal cancer patients

Histopathologic assessment is indispensable for diagnosing colorectal cancer (CRC). However, manual evaluation of the diseased tissues under the microscope cannot reliably inform patient prognosis or genomic variations crucial for treatment selections. To address these challenges, we develop the Multi-omics Multi-cohort Assessment (MOMA) platform, an explainable machine learning approach, to systematically identify and interpret the relationship between patients' histologic patterns, multi-omics, and clinical profiles in three large patient cohorts (n = 1888). MOMA successfully predicts the overall survival, disease-free survival (log-rank test P-value<0.05), and copy number alterations of CRC patients. In addition, our approaches identify interpretable pathology patterns predictive of gene expression profiles, microsatellite instability status, and clinically actionable genetic alterations. We show that MOMA models are generalizable to multiple patient populations with different demographic compositions and pathology images collected from distinctive digitization methods. Our machine learning approaches provide clinically actionable predictions that could inform treatments for colorectal cancer patients.

EGFR, VEGF, and angiogenesis promote the development of lipoma in the oral cavity

This study aimed to detect, quantify and compare the immunohistochemical expression of EGFR and VEGF and microvessel count (MVC) in oral lipomas, and to correlate the findings with clinical and morphological characteristics of the cases studied. The sample consisted of 54 oral lipomas (33 classic and 21 non-classic) and 23 normal adipose tissue specimens. Cytoplasmic and/or nuclear immunohistochemical staining of EGFR and VEGF was analyzed. The angiogenic index was determined by MVC. Cells were counted using the Image J® software. The Statistical Package for the Social Sciences was used for data analysis, adopting a level of significance of 5% for all statistical tests. A statistically significant difference in EGFR immunoexpression (p=0.047), especially, between classic lipomas and normal adipose tissue. There was a significant difference in MVC between non-classic lipomas and normal adipose tissue (p=0.022). In non-classic lipomas, only VEGF immunoexpression showed a significant moderate positive correlation (r=0.607, p=0.01) with MVC. In classic lipomas, the number of EGFR-immunostained adipocytes was directly proportional to the number of VEGF-positive cells, demonstrating a significant moderate positive correlation (r=0.566, p=0.005). The results suggest that EGFR, VEGF, and angiogenesis participate in the development of oral lipomas but are not primarily involved in the growth of these tumors.

CircRNAs: Roles in regulating head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC), the most common head and neck malignant tumor, with only monotherapy, is characterized by poor prognosis, and low 5-year survival rate. Due to the lack of therapeutic targets, the targeted drugs for HNSCC are rare. Therefore, exploring the regulation mechanism of HNSCC and identifying effective therapeutic targets will be beneficial to its treatment of. Circular RNA (CircRNA) is a class of RNA molecules with a circular structure, which is widely expressed in human body. CircRNAs regulate gene expression by exerting the function as a miRNA sponge, thereby mediating the occurrence and development of HNSCC cell proliferation, apoptosis, migration, invasion, and other processes. In addition, circRNAs are also involved in the regulation of tumor sensitivity to chemical drugs and other biological functions. In this review, we systematically listed the functions of circRNAs and explored the regulatory mechanisms of circRNAs in HNSCC from the aspects of tumor growth, cell death, angiogenesis, tumor invasion and metastasis, tumor stem cell regulation, tumor drug resistance, immune escape, and tumor microenvironment. It will assist us in discovering new diagnostic markers and therapeutic targets, while encourage new ideas for the diagnosis and treatment of HNSCC.

Sphingosine 1-phosphate lyase facilitates cancer progression through converting sphingolipids to glycerophospholipids

BACKGROUND

In addition to potent agonist properties for sphingosine 1-phosphate (S1P) receptors, intracellularly, S1P is an intermediate in metabolic conversion pathway from sphingolipids to glycerolysophospholipids (glyceroLPLs). We hypothesized that this S1P metabolism and its products might possess some novel roles in the pathogenesis of cancer, where S1P lyase (SPL) is a key enzyme.

METHODS

The mRNA levels of sphingolipid-related and other cancer-related factors were measured in human hepatocellular carcinoma (HCC), colorectal cancer, and esophageal cancer patients' tumours and in their adjacent non-tumour tissues. Phospholipids (PL) and glyceroLPLs were measured by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In-vitro experiments were performed in Colon 26 cell line with modulation of the SPL and GPR55 expressions. Xenograft model was used for determination of the cancer progression and for pharmacological influence.

RESULTS

Besides high SPL levels in human HCC and colon cancer, SPL levels were specifically and positively linked with levels of glyceroLPLs, including lysophosphatidylinositol (LPI). Overexpression of SPL in Colon 26 cells resulted in elevated levels of LPI and lysophosphatidylglycerol (LPG), which are agonists of GPR55. SPL overexpression-enhanced cell proliferation was inhibited by GPR55 silencing. Conversely, inhibition of SPL led to the opposite outcome and reversed by adding LPI, LPG, and metabolites generated during S1P degradation, which is regulated by SPL. The xenograft model results suggested the contribution of SPL and glyceroLPLs to tumour progression depending on levels of SPL and GPR55. Moreover, the pharmacological inhibition of SPL prevented the progression of cancer. The underlying mechanisms for the SPL-mediated cancer progression are the activation of p38 and mitochondrial function through the LPI, LPG-GPR55 axis and the suppression of autophagy in a GPR55-independent manner.

CONCLUSION

A new metabolic pathway has been proposed here in HCC and colon cancer, SPL converts S1P to glyceroLPLs, mainly to LPI and LPG, and facilitates cancer development.

Regulated cell death (RCD) in cancer: key pathways and targeted therapies

Regulated cell death (RCD), also well-known as programmed cell death (PCD), refers to the form of cell death that can be regulated by a variety of biomacromolecules, which is distinctive from accidental cell death (ACD). Accumulating evidence has revealed that RCD subroutines are the key features of tumorigenesis, which may ultimately lead to the establishment of different potential therapeutic strategies. Hitherto, targeting the subroutines of RCD with pharmacological small-molecule compounds has been emerging as a promising therapeutic avenue, which has rapidly progressed in many types of human cancers. Thus, in this review, we focus on summarizing not only the key apoptotic and autophagy-dependent cell death signaling pathways, but the crucial pathways of other RCD subroutines, including necroptosis, pyroptosis, ferroptosis, parthanatos, entosis, NETosis and lysosome-dependent cell death (LCD) in cancer. Moreover, we further discuss the current situation of several small-molecule compounds targeting the different RCD subroutines to improve cancer treatment, such as single-target, dual or multiple-target small-molecule compounds, drug combinations, and some new emerging therapeutic strategies that would together shed new light on future directions to attack cancer cell vulnerabilities with small-molecule drugs targeting RCD for therapeutic purposes.

Suppression of Ribose-5-Phosphate Isomerase a Induces ROS to Activate Autophagy, Apoptosis, and Cellular Senescence in Lung Cancer

Ribose-5-phosphate isomerase A (RPIA) regulates tumorigenesis in liver and colorectal cancer. However, the role of RPIA in lung cancer remains obscure. Here we report that the suppression of RPIA diminishes cellular proliferation and activates autophagy, apoptosis, and cellular senescence in lung cancer cells. First, we detected that RPIA protein was increased in the human lung cancer versus adjust normal tissue via tissue array. Next, the knockdown of RPIA in lung cancer cells displayed autophagic vacuoles, enhanced acridine orange staining, GFP-LC3 punctae, accumulated autophagosomes, and showed elevated levels of LC3-II and reduced levels of p62, together suggesting that the suppression of RPIA stimulates autophagy in lung cancer cells. In addition, decreased RPIA expression induced apoptosis by increasing levels of Bax, cleaved PARP and caspase-3 and apoptotic cells. Moreover, RPIA knockdown triggered cellular senescence and increased p53 and p21 levels in lung cancer cells. Importantly, RPIA knockdown elevated reactive oxygen species (ROS) levels. Treatment of ROS scavenger N-acetyl-L-cysteine (NAC) reverts the activation of autophagy, apoptosis and cellular senescence by RPIA knockdown in lung cancer cells. In conclusion, RPIA knockdown induces ROS levels to activate autophagy, apoptosis, and cellular senescence in lung cancer cells. Our study sheds new light on RPIA suppression in lung cancer therapy.

FIP-nha, a fungal immunomodulatory protein from Nectria haematococca, induces apoptosis and autophagy in human gastric cancer cells via blocking the EGFR-mediated STAT3/Akt signaling pathway

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FIP-nha, a new FIP discovered beyond Basidiomycota, has been demonstrated a broad spectrum of antitumor activity and cell selectivity against human cancers.

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FIP-nha inhibited the growth, induced apoptosis and autophagy of gastric cancer cells through competitively binding to EGFR with EGF to blocking the EGFR-mediated STAT3/Akt pathway.

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FIP-nha may be a potential chemotherapy drug that targeted EGFR to treat human gastric cancer.

FIP-nha, a fungal immunomodulatory protein from Nectria haematococca, has been demonstrated a broad spectrum of antitumor activity and cell selectivity against human cancers in our previous study. However, the effect and mechanism of FIP-nha on gastric cancer remains unclear. In this study, we systematically observed the cytotoxicity, biological effect, regulatory mechanism and interaction target of FIP-nha on human gastric cancer cell lines, AGS and SGC7901. Our results demonstrated that FIP-nha inhibited the growth of AGS and SGC7901 cells in a dose-dependent manner and exerted proapoptotic effects on both cells as confirmed by flow cytometry, DAPI staining and western blot analysis. Additionally, the exposure of AGS and SGC7901 to FIP-nha induced autophagy as indicated by western blot analysis, GFP-LC3 and mCherry-GFP-LC3 transfection and acridine orange staining. Furthermore, we found that FIP-nha decreased the phosphorylation of EGFR, STAT3 and Akt and inhibited activation effect of ligand factor EGF to EGFR and its downstream signal molecule STAT3 and Akt. Finally, we proved that FIP-nha located on the surface of gastric cancer cells and bound directly to the transmembrane protein of EGFR by immunoprecipitation, cellular localization, molecular docking, microscale thermophoresis assay. The above findings indicated that FIP-nha inhibited the growth of gastric cancer and induced apoptosis and autophagy through competitively binding to EGFR with EGF to blocking the EGFR-mediated STAT3/Akt pathway. In summary, our study provided novel insights regarding the activity of FIP-nha against gastric cancer and contributed to the clinical application of FIP-nha as a potential chemotherapy drugs that targeted EGFR for human gastric cancer.

Inhibitory role of proguanil on the growth of bladder cancer via enhancing EGFR degradation and inhibiting its downstream signaling pathway to induce autophagy

A major reason for the high mortality of patients with bladder cancer (BC) is that chemotherapy and surgery are only effective for very limited patients. Thus, developing novel treatment options becomes an urgent need for improving clinical outcomes and the quality of life for BC patients. Here, we demonstrated that proguanil significantly inhibited the growth of BC in vitro and in vivo. Importantly, our results indicated that the sensitivity of BC cells to proguanil is positively correlated with the expression of epidermal growth factor receptor (EGFR). Mechanistically, proguanil specifically targeted EGFR and promoted EGFR binding to Caveolin-1, enhanced its endocytosis in a Clathrin-independent manner, and then recruited c-Cbl to promote EGFR ubiquitination and degradation through the lysosomal pathway. Further studies suggested that proguanil induced autophagy by destabilizing EGFR and inhibiting its downstream signaling pathway. Thus, this study reveals the novel mechanism of proguanil on anticancer activity and implies the potential benefits of this drug in the treatment of BC.

PI3K inhibitor 3-MA promotes the antiproliferative activity of esomeprazole in gastric cancer cells by downregulating EGFR via the PI3K/FOXO3a pathway

Gastric cancer is a common gastrointestinal malignancy worldwide, with a high mortality rate and poor prognosis. Esomeprazole (ESO) has been shown to have anticancer activity by affecting cell growth and autophagy and its mechanism in gastric cancer cells is evident. The PI3K/AKT/FOXO3a pathway is central in cancers. 3-Methyladenine (3-MA), a dual inhibitor of PI3K and autophagy, plays a synergistic role in combination with antitumor agents. In this study, we assessed the role of ESO on the PI3K/AKT/FOXO3a pathway and the beneficial effects of ESO combined with 3-MA in gastric cancer cells. Cell viability, proliferation, invasion, migration, apoptosis, autophagy, and protein expression were detected by CCK-8, EdU, Transwell, flow cytometry, immunofluorescence assay, and western blot. ESO decreased cell viability in a concentration- and time-dependent manner and increased autophagy with upregulation of LC3II and P62. Additionally, ESO inhibited the proliferation, migration, and invasion and induced the apoptosis of gastric cancer cells in a concentration-dependent manner. ESO inhibited PI3K/AKT/FOXO3a signaling and EGFR and SKP2 expression concentration-dependent. 3-MA enhanced the antiproliferative activity of ESO and synergistically inhibited PI3K/FOXO3a signaling and the expression of EGFR but not SKP2. Furthermore, pretreatment with the EGFR inhibitor AG1478 enhanced the antiproliferative activity of ESO in gastric cancer cells. In conclusion, our results suggested that the PI3K inhibitor 3-MA promotes the antiproliferative activity of ESO in gastric cancer cells by synergistically downregulating EGFR via the PI3K/FOXO3a pathway.

Regulation of Cell-Signaling Pathways by Berbamine in Different Cancers

Natural product research is a cornerstone of the architectural framework of clinical medicine. Berbamine is a natural, potent, pharmacologically active biomolecule isolated from Berberis amurensis. Berbamine has been shown to modulate different oncogenic cell-signaling pathways in different cancers. In this review, we comprehensively analyze how berbamine modulates deregulated pathways (JAK/STAT, CAMKII/c-Myc) in various cancers. We systematically analyze how berbamine induces activation of the TGF/SMAD pathway for the effective inhibition of cancer progression. We also summarize different nanotechnological strategies currently being used for proficient delivery of berbamine to the target sites. Berbamine has also been reported to demonstrate potent anti-cancer and anti-metastatic effects in tumor-bearing mice. The regulation of non-coding RNAs by berbamine is insufficiently studied, and future studies must converge on the identification of target non-coding RNAs. A better understanding of the regulatory role of berbamine in the modulation of non-coding RNAs and cell-signaling pathways will be advantageous in the effective translation of laboratory findings to clinically effective therapeutics.

Synergistic inhibitory effect of berberine and icotinib on non-small cell lung cancer cells via inducing autophagic cell death and apoptosis

Resistance to epidermal growth factor receptor-tyrosin kinase inhibitors (TKIs, e.g. icotinib) remains a major clinical challenge. Non-small cell lung cancer patients with wild-type EGFR and/or K-RAS mutation are primary resistance to EGFR-TKIs. Berberine has been found to have potent anticancer activities via distinct molecular mechanism. In this study, we sought to investigate the therapeutic utility of BBR in combination with icotinib to overcome icotinib resistance in NSCLC cells, and explore the molecular mechanism of synergism of icotinib and BBR to EGFR-resistant NSCLC cells. We used the two EGFR-resistant NSCLC cell lines H460 and H1299 for testing the inhibitory effect of icotinib and/or BBR on them. Moreover, xenograft mouse model was applied for assessing the anti-tumor activities of BBR and icotinib in combination. Results showed that BBR and icotinib have a synergistic inhibitory effect on H460 and H1299 cells through induction of autophagic cell death and apoptosis. Accordingly, the anti-cancer effect of BBR plus icotinib was further confirmed in the NSCLC xenograft mouse models. Combination of BBR and icotinib significantly inhibited the protein expression and the activity of EGFR by inducing autophagic EGFR degradation. BBR plus icotinib resulted in intracellular ROS accumulation, which could mediated autophagy and apoptosis and involved in the suppression of cell migration and invasion. In conclusions, combination application of BBR and icotinib could be an effective strategy to overcome icotinib resistance in the treatment of NSCLC.

Klotho as Potential Autophagy Regulator and Therapeutic Target

The protein Klotho can significantly delay aging, so it has attracted widespread attention. Abnormal downregulation of Klotho has been detected in several aging-related diseases, such as Alzheimer’s disease, kidney injury, cancer, chronic obstructive pulmonary disease (COPD), vascular disease, muscular dystrophy and diabetes. Conversely, many exogenous and endogenous factors, several drugs, lifestyle changes and genetic manipulations were reported to exert therapeutic effects through increasing Klotho expression. In recent years, Klotho has been identified as a potential autophagy regulator. How Klotho may contribute to reversing the effects of aging and disease became clearer when it was linked to autophagy, the process in which eukaryotic cells clear away dysfunctional proteins and damaged organelles: the abovementioned diseases involve abnormal autophagy. Interestingly, growing evidence indicates that Klotho plays a dual role as inducer or inhibitor of autophagy in different physiological or pathological conditions through its influence on IGF-1/PI3K/Akt/mTOR signaling pathway, Beclin 1 expression and activity, as well as aldosterone level, which can help restore autophagy to beneficial levels. The present review examines the role of Klotho in regulating autophagy in Alzheimer’s disease, kidney injury, cancer, COPD, vascular disease, muscular dystrophy and diabetes. Targeting Klotho may provide a new perspective for preventing and treating aging-related diseases.

Long non-coding RNA HLA complex group 18 promotes gastric cancer progression by targeting microRNA-370-3p expression

OBJECTIVES

Our research was aimed at investigating the biological character of human leukocyte antigen complex group 18 (HCG18) on gastric cancer (GC) progression and its potential mechanisms.

METHODS

The expression characteristics and prognostic values of HCG18 in GC were evaluated through the GEPIA database and Kaplan-Meier plotter database. Quantitative real-time PCR and Western blot were used for quantification of messenger RNA expression, microRNA (miRNA) expression and protein expression. Cell proliferation, migration and invasion were detected by cell counting kit-8 assay, 5'-bromo-2'-deoxyuridine assay and Transwell assay, respectively. Dual-luciferase reporter gene assay and RNA immunoprecipitation assay were used for examination of the interactions among HCG18, miR-370-3p and epidermal growth factor receptor (EGFR) 3'UTR.

KEY FINDINGS

HCG18 expression was up-regulated in GC tissues, and its high expression was closely associated with increased tumour size, advanced TNM stage, poor differentiation of tumour tissues and unfavourable prognosis of patients with GC. Additionally, HCG18 overexpression promoted the proliferation, migration and invasion of GC cells, and its knockdown suppressed the malignant phenotypes of GC cells. Furthermore, HCG18 served as a miRNA sponge to repress miR-370-3p and indirectly up-regulated EGFR expression in GC cells.

CONCLUSIONS

HCG18 served as a tumour-promoting factor in GC progression by modulating the miR-370-3p/EGFR axis.

G protein pathway suppressor 2 suppresses gastric cancer by destabilizing epidermal growth factor receptor

G protein pathway suppressor 2 (GPS2) is expressed in most human tissues, including the stomach. However, the biological functions of GPS2 in cancer, as well as the underlying molecular mechanisms, remain poorly understood. Here, we report that GPS2 expression was aberrantly downregulated in gastric cancer (GC) tissues compared with control tissues. Clinicopathologic analysis showed that low GPS2 expression was significantly correlated with pathological grade, lymph node stage, and invasive depth. Kaplan‐Meier analysis indicated that patients with low GPS2 expression showed poorer overall survival rates than those with high GPS2 expression. Moreover, GPS2 overexpression decreased GC cell proliferation, colony formation, tumorigenesis, and invasion. Overexpression of GPS2 reduced the protein expression of epidermal growth factor receptor (EGFR) and inhibited its downstream signaling in GC cells. Interestingly, GPS2 decreased EGFR protein expression, which was reversed by a lysosome inhibitor. Furthermore, GPS2 reduced EGFR protein stability by enhancing the binding of EGFR and an E3 ligase, c‐Cbl, which promoted the ubiquitination of EGFR, ultimately leading to its degradation through the lysosomal pathway. Further analysis indicated that GPS2 activated autophagy and promoted the autophagic flux by destabilizing EGFR. Taken together, these results suggest that low GPS2 expression is associated with GC progression and provide insights into the applicability of the GPS2‐EGFR axis as a potential therapeutic target in GC.

Targeted disruption of GAK stagnates autophagic flux by disturbing lysosomal dynamics

The autophagy-lysosome system allows cells to adapt to environmental changes by regulating the degradation and recycling of cellular components, and to maintain homeostasis by removing aggregated proteins and defective organelles. Cyclin G-associated kinase (GAK) is involved in the regulation of clathrin-dependent endocytosis and cell cycle progression. In addition, a single nucleotide polymorphism at the GAK locus has been reported as a risk factor for Parkinson's disease. However, the roles of GAK in the autophagy-lysosome system are not completely understood, thus the present study aimed to clarify this. In the present study, under genetic disruption or chemical inhibition of GAK, analyzing autophagic flux and observing morphological changes of autophagosomes and autolysosomes revealed that GAK controlled lysosomal dynamics via actomyosin regulation, resulting in a steady progression of autophagy. GAK knockout (KO) in A549 cells impaired autophagosome-lysosome fusion and autophagic lysosome reformation, which resulted in the accumulation of enlarged autophagosomes and autolysosomes during prolonged starvation. The stagnation of autophagic flux accompanied by these phenomena was also observed with the addition of a GAK inhibitor. Furthermore, the addition of Rho-associated protein kinase (ROCK) inhibitor or ROCK1 knockdown mitigated GAK KO-mediated effects. The results suggested a vital role of GAK in controlling lysosomal dynamics via maintaining lysosomal homeostasis during autophagy.

Advances in autophagy as a target in the treatment of tumours

Autophagy is a multi-step lysosomal degradation process, which regulates energy and material metabolism and has been used to maintain homeostasis. Autophagy has been shown to be involved in the regulation of health and disease. But at present, there is no consensus on the relationship between autophagy and tumour, and we consider that it plays a dual role in the occurrence and development of tumour. That is to say, under certain conditions, it can inhibit the occurrence of tumour, but it can also promote the process of tumour. Therefore, autophagy could be used as a target for tumour treatment. The regulation of autophagy plays a synergistic role in the radiotherapy, chemotherapy, phototherapy and immunotherapy of tumour, and nano drug delivery system provides a promising strategy for improving the efficacy of autophagy regulation. This review summarised the progress in the regulatory pathways and factors of autophagy as well as nanoformulations as carriers for the delivery of autophagy modulators.

Identification of an autophagy-related prognostic signature in head and neck squamous cell carcinoma

BACKGROUND

Autophagy-related genes (ARGs) have been significantly implicated in tumorigenesis and served as promising prognostic biomarkers for human cancer. Hence, this study was aimed to develop an ARGs-based prognostic signature for Head and neck squamous cell carcinoma (HNSCC).

METHODS

Prognostic ARG candidates were identified by univariate and multivariate Cox regression analysis in the training dataset (TCGA-HNSC) and incorporated into a 3-ARGs (EGFR, FADD, and PARK2) prognostic signature which was further verified in two independent validation cohorts (GSE41613 and GSE42743). Kaplan-Meier plots, Cox regression analyses, and receiver operating characteristics curves (ROC) were employed to evaluate the prognostic prediction of 3-ARGs signature. Differential expression of these 3 ARG between cancer and normal counterparts as well as their associations with autophagy markers were assessed in 60 pairs of freshly collected HNSCC and adjacent non-tumor samples and datasets from Human Protein Atlas, respectively.

RESULTS

Patients with high-risk score had significantly inferior overall survival. Multivariate regression analyses revealed that 3-ARGs signature could be an independent prognostic factor after adjusting various clinicopathological parameters. ROC analyses revealed high predictive accuracy and sensitivity of the 3-ARGs signature. Increased mRNA and protein expression of EGFR, FADD, and PARK2 were found in HNSCC samples, and their expression significantly correlated with the abundances of ATG5, Beclin1, and LC3.

CONCLUSION

Our results reveal that 3-ARGs signature is a powerful prognostic biomarker for HNSCC, which could be integrated into the current prognostic regime to realize individualized outcome prediction. EGFR, FADD, and PARK2 likely contributed to autophagy during HNSCC tumorigenesis.

A mechanistic review of the anticancer potential of hesperidin, a natural flavonoid from citrus fruits

Hesperidin, a phytoactive compound, is an abundant and economical dietary bioflavonoid possessing numerous biological and medicinal benefits. Several studies have strongly proven the significant chemotherapeutic potential of hesperidin. Therefore, this review aims to bring together the existing studies demonstrating hesperidin as a potential anticancer agent with its mode of action reported in the therapeutic strategies for numerous cancer types. Hesperidin acts via modulating multiple pathways involving cell cycle arrest, apoptosis, antiangiogenic, antimetastatic and DNA repair in various cancer cells. Hesperidin has been reported to alter several molecular targets related to carcinogenesis, such as reactive nitrogen species, cellular kinases, transcription factors, reactive oxygen species, drug transporters, cell cycle mediators and inflammatory cytokines. Collectively, this review provides significant insights for the potential of hesperidin to be a strong and promising candidate for pharmaceuticals, functional foods, dietary supplements, nutraceuticals and geared toward the better management of carcinoma.

Characterization of TGFβ-associated molecular features and drug responses in gastrointestinal adenocarcinoma

Background

Gastrointestinal adenocarcinoma (GIAD) has caused a serious disease burden globally. Targeted therapy for the transforming growth factor beta (TGF-β) signaling pathway is becoming a reality. However, the molecular characterization of TGF-β associated signatures in GIAD requires further exploration.

Methods

Multi-omics data were collected from TCGA and GEO database. A pivotal unsupervised clustering for TGF-β level was performed by distinguish status of TGF-β associated genes. We analyzed differential mRNAs, miRNAs, proteins gene mutations and copy number variations in both clusters for comparison. Enrichment of pathways and gene sets were identified in each type of GIAD. Then we performed differential mRNA related drug response by collecting data from GDSC. At last, a summarized deep neural network for TGF-β status and GIADs was constracted.

Results

The TGF-β^high group had a worse prognosis in overall GIAD patients, and had a worse prognosis trend in gastric cancer and colon cancer specifically. Signatures (including mRNA and proteins) of the TGF-β^high group is highly correlated with EMT. According to miRNA analysis, miR-215-3p, miR-378a-5p, and miR-194-3p may block the effect of TGF-β. Further genomic analysis showed that TGF-β^low group had more genomic changes in gastric cancer, such as TP53 mutation, EGFR amplification, and SMAD4 deletion. And drug response dataset revealed tumor-sensitive or tumor-resistant drugs corresponding to TGF-β associated mRNAs. Finally, the DNN model showed an excellent predictive effect in predicting TGF-β status in different GIAD datasets.

Conclusions

We provide molecular signatures associated with different levels of TGF-β to deepen the understanding of the role of TGF-β in GIAD and provide potential drug possibilities for therapeutic targets in different levels of TGF-β in GIAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01869-4.

Mini review: The FDA-approved prescription drugs that target the MAPK signaling pathway in women with breast cancer

Breast cancer (BC) is the most common cancer and the prevalent type of malignancy among women. Multiple risk factors, including genetic changes, biological age, dense breast tissue, and obesity are associated with BC. The mitogen-activated protein kinases (MAPK) signaling pathway has a pivotal role in regulating biological functions such as cell proliferation, differentiation, apoptosis, and survival. It has become evident that the MAPK pathway is associated with tumorigenesis and may promote breast cancer development. The MAPK/RAS/RAF cascade is closely associated with breast cancer. RAS signaling can enhance BC cell growth and progression. B-Raf is an important kinase and a potent RAF isoform involved in breast tumor initiation and differentiation. Depending on the reasons for cancer, there are different strategies for treatment of women with BC. Till now, several FDA-approved treatments have been investigated that inhibit the MAPK pathway and reduce metastatic progression in breast cancer. The most common breast cancer drugs that regulate or inhibit the MAPK pathway may include Farnesyltransferase inhibitors (FTIs), Sorafenib, Vemurafenib, PLX8394, Dabrafenib, Ulixertinib, Simvastatin, Alisertib, and Teriflunomide. In this review, we will discuss the roles of the MAPK/RAS/RAF/MEK/ERK pathway in BC and summarize the FDA-approved prescription drugs that target the MAPK signaling pathway in women with BC.

Blue LED causes autophagic cell death in human osteosarcoma by increasing ROS generation and dephosphorylating EGFR

Osteosarcoma (OS) is the most common primary malignant bone tumour in adolescence. Lately, light‐emitting diodes (LED)‐based therapy has emerged as a new promising approach for several diseases. However, it remains unknown in human OS. Here, we found that the blue LED irradiation significantly suppressed the proliferation, migration and invasion of human OS cells, while we observed blue LED irradiation increased ROS production through increased NADPH oxidase enzymes NOX2 and NOX4, as well as decreased Catalase (CAT) expression levels. Furthermore, we revealed blue LED irradiation‐induced autophagy characterized by alterations in autophagy protein markers including Beclin‐1, LC3‐II/LC3‐I and P62. Moreover, we demonstrated an enhanced autophagic flux. The blockage of autophagy displayed a remarkable attenuation of anti‐tumour activities of blue LED irradiation. Next, ROS scavenger N‐acetyl‐L‐cysteine (NAC) and NOX inhibitor diphenyleneiodonium (DPI) blocked suppression of OS cell growth, indicating that ROS accumulation might play an essential role in blue LED‐induced autophagic OS cell death. Additionally, we observed blue LED irradiation decreased EGFR activation (phosphorylation), which in turn led to Beclin‐1 release and subsequent autophagy activation in OS cells. Analysis of EGFR colocalization with Beclin‐1 and EGFR‐immunoprecipitation (IP) assay further revealed the decreased interaction of EGFR and Beclin‐1 upon blue LED irradiation in OS cells. In addition, Beclin‐1 down‐regulation abolished the effects of blue LED irradiation on OS cells. Collectively, we concluded that blue LED irradiation exhibited anti‐tumour effects on OS by triggering ROS and EGFR/Beclin‐1‐mediated autophagy signalling pathway, representing a potential approach for human OS treatment.

Racially Disparate Expression of mTOR/ERK-1/2 Allied Proteins in Cancer

Recent studies revealed that ethnic differences in mechanistic target of rapamycin (mTOR) and extracellular signal-regulated kinase (ERK-1/2) signaling pathways might be associated with the development and progression of different human malignancies. The African American (AA) population has an increased rate of cancer incidence and mortality compared to the Caucasian American (CA) population. Although the socioeconomic differences across different ethnic groups contribute to the disparity in developing different cancers, recent scientific evidence indicates the association of molecular and genetic variations in racial disparities of different human malignancies. The mTOR and ERK-1/2 signaling pathways are one of the well-known oncogenic signaling mechanisms that regulate diverse molecular and phenotypic aspects of normal as well as cancer cells in response to different external or internal stimuli. To date, very few studies have been carried out to explore the significance of racial disparity with abnormal mTOR and ERK-1/2 kinase signaling pathways, which may contribute to the development of aggressive human cancers. In this review, we discuss the differential regulation of mTOR and ERK-1/2 kinase signaling pathways across different ethnic groups, especially between AA and CA populations. Notably, we observed that key signaling proteins associated with mTOR and ERK-1/2 pathway including transforming growth factor-beta (TGF-β), Akt, and VEGFR showed racially disparate expression in cancer patients. Overall, this review article encompasses the significance of racially disparate signaling molecules related to mTOR/ERK1/2 and their potential in developing tailor-made anti-cancer therapies.

Gefitinib Results in Robust Host-Directed Immunity Against Salmonella Infection Through Proteo-Metabolomic Reprogramming

The global rise of antibiotic-resistant strains of Salmonella has necessitated the development of alternative therapeutic strategies. Recent studies have shown that targeting host factors may provide an alternative approach for the treatment of intracellular pathogens. Host-directed therapy (HDT) modulates host cellular factors that are essential to support the replication of the intracellular pathogens. In the current study, we identified Gefitinib as a potential host directed therapeutic drug against Salmonella. Further, using the proteome analysis of Salmonella-infected macrophages, we identified EGFR, a host factor, promoting intracellular survival of Salmonella via mTOR-HIF-1α axis. Blocking of EGFR, mTOR or HIF-1α inhibits the intracellular survival of Salmonella within the macrophages and in mice. Global proteo-metabolomics profiling indicated the upregulation of host factors predominantly associated with ATP turn over, glycolysis, urea cycle, which ultimately promote the activation of EGFR-HIF1α signaling upon infection. Importantly, inhibition of EGFR and HIF1α restored both proteomics and metabolomics changes caused by Salmonella infection. Taken together, this study identifies Gefitinib as a host directed drug that holds potential translational values against Salmonella infection and might be useful for the treatment of other intracellular infections.

Treatment of Brain Metastases of Non-Small Cell Lung Carcinoma

Lung cancer is one of the most common malignant neoplasms. As a result of the disease's progression, patients may develop metastases to the central nervous system. The prognosis in this location is unfavorable; untreated metastatic lesions may lead to death within one to two months. Existing therapies-neurosurgery and radiation therapy-do not improve the prognosis for every patient. The discovery of Epidermal Growth Factor Receptor (EGFR)-activating mutations and Anaplastic Lymphoma Kinase (ALK) rearrangements in patients with non-small cell lung adenocarcinoma has allowed for the introduction of small-molecule tyrosine kinase inhibitors to the treatment of advanced-stage patients. The Epidermal Growth Factor Receptor (EGFR) is a transmembrane protein with tyrosine kinase-dependent activity. EGFR is present in membranes of all epithelial cells. In physiological conditions, it plays an important role in the process of cell growth and proliferation. Binding the ligand to the EGFR causes its dimerization and the activation of the intracellular signaling cascade. Signal transduction involves the activation of MAPK, AKT, and JNK, resulting in DNA synthesis and cell proliferation. In cancer cells, binding the ligand to the EGFR also leads to its dimerization and transduction of the signal to the cell interior. It has been demonstrated that activating mutations in the gene for EGFR-exon19 (deletion), L858R point mutation in exon 21, and mutation in exon 20 results in cancer cell proliferation. Continuous stimulation of the receptor inhibits apoptosis, stimulates invasion, intensifies angiogenesis, and facilitates the formation of distant metastases. As a consequence, the cancer progresses. These activating gene mutations for the EGFR are present in 10-20% of lung adenocarcinomas. Approximately 3-7% of patients with lung adenocarcinoma have the echinoderm microtubule-associated protein-like 4 (EML4)/ALK fusion gene. The fusion of the two genes EML4 and ALK results in a fusion gene that activates the intracellular signaling pathway, stimulates the proliferation of tumor cells, and inhibits apoptosis. A new group of drugs-small-molecule tyrosine kinase inhibitors-has been developed; the first generation includes gefitinib and erlotinib and the ALK inhibitor crizotinib. These drugs reversibly block the EGFR by stopping the signal transmission to the cell. The second-generation tyrosine kinase inhibitor (TKI) afatinib or ALK inhibitor alectinib block the receptor irreversibly. Clinical trials with TKI in patients with non-small cell lung adenocarcinoma with central nervous system (CNS) metastases have shown prolonged, progression-free survival, a high percentage of objective responses, and improved quality of life. Resistance to treatment with this group of drugs emerging during TKI therapy is the basis for the detection of resistance mutations. The T790M mutation, present in exon 20 of the EGFR gene, is detected in patients treated with first- and second-generation TKI and is overcome by Osimertinib, a third-generation TKI. The I117N resistance mutation in patients with the ALK mutation treated with alectinib is overcome by ceritinib. In this way, sequential therapy ensures the continuity of treatment. In patients with CNS metastases, attempts are made to simultaneously administer radiation therapy and tyrosine kinase inhibitors. Patients with lung adenocarcinoma with CNS metastases, without activating EGFR mutation and without ALK rearrangement, benefit from immunotherapy. This therapeutic option blocks the PD-1 receptor on the surface of T or B lymphocytes or PD-L1 located on cancer cells with an applicable antibody. Based on clinical trials, pembrolizumab and all antibodies are included in the treatment of non-small cell lung carcinoma with CNS metastases.

Activation of mitochondrial TUFM ameliorates metabolic dysregulation through coordinating autophagy induction

Disorders of autophagy, a key regulator of cellular homeostasis, cause a number of human diseases. Due to the role of autophagy in metabolic dysregulation, there is a need to identify autophagy regulators as therapeutic targets. To address this need, we conducted an autophagy phenotype-based screen and identified the natural compound kaempferide (Kaem) as an autophagy enhancer. Kaem promoted autophagy through translocation of transcription factor EB (TFEB) without MTOR perturbation, suggesting it is safe for administration. Moreover, Kaem accelerated lipid droplet degradation in a lysosomal activity-dependent manner in vitro and ameliorated metabolic dysregulation in a diet-induced obesity mouse model. To elucidate the mechanism underlying Kaem’s biological activity, the target protein was identified via combined drug affinity responsive target stability and LC–MS/MS analyses. Kaem directly interacted with the mitochondrial elongation factor TUFM, and TUFM absence reversed Kaem-induced autophagy and lipid degradation. Kaem also induced mitochondrial reactive oxygen species (mtROS) to sequentially promote lysosomal Ca²⁺ efflux, TFEB translocation and autophagy induction, suggesting a role of TUFM in mtROS regulation. Collectively, these results demonstrate that Kaem is a potential therapeutic candidate/chemical tool for treating metabolic dysregulation and reveal a role for TUFM in autophagy for metabolic regulation with lipid overload.

Kim, Hwang et al. use in vitro and in vivo models of autophagy disorder/metabolic dysfunction to show that in this context, the natural compound kaempferide is an autophagy enhancer and reveal that one of the underlying mechanisms governing this is mediated by the mitochondrial elongation factor TUFM. This insight may have therapeutic value in the treatment of metabolic disorders.

ATG7-dependent and independent autophagy determine the type of treatment in lung cancer

Based on the role of ATG7 in the initiation of autophagy, autophagy can be divided into ATG7-dependent selective autophagy and ATG7-independent alternative autophagy. However, the detailed roles of two different types of autophagy in antitumor therapy have not been fully elucidated so far. Here, we for the first time demonstrated an investigational inducer, w09, could induce both selective autophagy and alternative autophagy in NSCLC, but the phenotypes of these two kinds of autophagy are different：(1) w09-induced selective autophagy mainly promoted cell apoptosis, while w09-triggered alternative autophagy markedly induced autophagic cell death in NSCLC；(2) w09-induced ATG7 dependent autophagy mainly promoted the accumulation of SQSTM1/p62, while w09-triggered ATG7 independent autophagy markedly accelerated the degradation of SQSTM1/p62. These above results were further confirmed by knockout ATG7 gene in A549 cells or restoration of ATG7 function in H1650 cells. Deletion of ATG7 gene markedly attenuated the effect of w09-induced autophagy or apoptosis on A549 cells, while restoration of functional ATG7 markedly enhanced the effect of w09-induced autophagy and apoptosis on H1650 cells. Mechanistically, we further revealed that w09 induced two different types of autophagy through inhibiting PI3K/AKT/mTOR signaling pathway. Notably, compared with A549WT xenograft model, the in vivo antitumor effect of w09 or Taxel on the ATG7-deficient A549 xenograft model was significantly attenuated. Therefore, a special attention must be paid to distinguish which kinds of autophagy have been induced by autophagy inducers with antitumor agents by targeting PI3K/AKT/mTOR signaling pathway.

Proteoglycans in the Pathogenesis of Hormone-Dependent Cancers: Mediators and Effectors

Hormone-dependent cancers exhibit high morbidity and mortality. In spite of advances in therapy, the treatment of hormone-dependent cancers remains an unmet health need. The tumor microenvironment (TME) exhibits unique characteristics that differ among various tumor types. It is composed of cancerous, non-cancerous, stromal, and immune cells that are surrounded and supported by components of the extracellular matrix (ECM). Therefore, the interactions among cancer cells, stromal cells, and components of the ECM determine cancer progression and response to therapy. Proteoglycans (PGs), hybrid molecules consisting of a protein core to which sulfated glycosaminoglycan chains are bound, are significant components of the ECM that are implicated in all phases of tumorigenesis. These molecules, secreted by both the stroma and cancer cells, are crucial signaling mediators that modulate the vital cellular pathways implicated in gene expression, phenotypic versatility, and response to therapy in specific tumor types. A plethora of deregulated signaling pathways contributes to the growth, dissemination, and angiogenesis of hormone-dependent cancers. Specific inputs from the endocrine and immune systems are some of the characteristics of hormone-dependent cancer pathogenesis. Importantly, the mechanisms involved in various aspects of cancer progression are executed in the ECM niche of the TME, and the PG components crucially mediate these processes. Here, we comprehensively discuss the mechanisms through which PGs affect the multifaceted aspects of hormone-dependent cancer development and progression, including cancer metastasis, angiogenesis, immunobiology, autophagy, and response to therapy.

Doxazosin, a Classic Alpha 1-Adrenoceptor Antagonist, Overcomes Osimertinib Resistance in Cancer Cells via the Upregulation of Autophagy as Drug Repurposing

Osimertinib, which is a third-generation epidermal growth factor receptor tyrosine kinase inhibitor, is an important anticancer drug because of its high efficacy and excellent safety profile. However, resistance against osimertinib is inevitable; therefore, therapeutic strategies to overcome the resistance are needed. Doxazosin, a classic quinazoline-based alpha 1-adrenoceptor antagonist is used to treat hypertension and benign prostatic hyperplasia with a known safety profile. The anticancer effects of doxazosin have been examined in various types of malignancies from the viewpoint of drug repositioning or repurposing. However, it currently remains unclear whether doxazosin sensitizes cancer cells to osimertinib. Herein, we demonstrated that doxazosin induced autophagy and enhanced the anticancer effects of osimertinib on the cancer cells and cancer stem cells of non-small cell lung cancer, pancreatic cancer, and glioblastoma at a concentration at which the growth of non-tumor cells was not affected. The osimertinib-sensitizing effects of doxazosin were suppressed by 3-methyladenine, an inhibitor of autophagy, which suggested that the effects of doxazosin were mediated by autophagy. The present study provides evidence for the efficacy of doxazosin as a combination therapy with osimertinib to overcome resistance against osimertinib.

Exosomal cargos modulate autophagy in recipient cells via different signaling pathways

Vesicular system of mammalian cells is composed of two intracellular and extracellular vesicles systems, which contributes to the intra/intercellular communication and cellular homeostasis. These systems mediate transferring of biological molecules like proteins, nucleic acids, and lipids inside the cytoplasm, and between the cells. By the present study, authors describe molecular crosslink between exosome biogenesis and autophagy and take a certain focus on the autophagic cargos of exosomes and signaling pathways involved in exosome-induced autophagy in target cells and vice versa. Autophagy the generation of double-phospholipid vesicles, is a process that engulfs damaged proteins and organelles, share molecular similarity and function synergy with exosomes biogenesis for degradation or exocytosis of certain cargo. Exosomes, the smallest subtype of extracellular vesicles, originating from the membrane of the multivesicular body located inside cells demonstrate key roles in the intracellular and intercellular communication. Growing evidence demonstrates the interaction between exosome biogenesis and autophagy both at intertwined molecular pathways and crossbred vesicles known as amphisomes. Crosstalk between exosome biogenesis and autophagy contributes to maintain cellular homeostasis under external and internal stresses. Moreover, these processes can modulate each other via different signaling pathways. Exosomes contain autophagic cargos that induce autophagy via the cascade of molecular events in target cells, which called here exosome-induced autophagy. Taken together, crosstalk between exosome biogenesis and autophagy plays pivotal roles in cell homeostasis. Shedding light on the interaction between endomembrane systems may promote our knowledge about the relation between exosome and autophagy pathways in lysosome-related disorders against treatments; proposing a theoretical approach for therapy.

Integrative Network Analysis of Differentially Methylated and Expressed Genes for Biomarker Identification in Leukemia

Genome-wide DNA methylation and gene expression are commonly altered in pediatric acute lymphoblastic leukemia (PALL). Integrated network analysis of cytosine methylation and expression datasets has the potential to provide deeper insights into the complex disease states and their causes than individual disconnected analyses. With the purpose of identifying reliable cancer-associated methylation signal in gene regions from leukemia patients, we present an integrative network analysis of differentially methylated (DMGs) and differentially expressed genes (DEGs). The application of a novel signal detection-machine learning approach to methylation analysis of whole genome bisulfite sequencing (WGBS) data permitted a high level of methylation signal resolution in cancer-associated genes and pathways. This integrative network analysis approach revealed that gene expression and methylation consistently targeted the same gene pathways relevant to cancer: Pathways in cancer, Ras signaling pathway, PI3K-Akt signaling pathway, and Rap1 signaling pathway, among others. Detected gene hubs and hub sub-networks were integrated by signature loci associated with cancer that include, for example, NOTCH1, RAC1, PIK3CD, BCL2, and EGFR. Statistical analysis disclosed a stochastic deterministic relationship between methylation and gene expression within the set of genes simultaneously identified as DEGs and DMGs, where larger values of gene expression changes were probabilistically associated with larger values of methylation changes. Concordance analysis of the overlap between enriched pathways in DEG and DMG datasets revealed statistically significant agreement between gene expression and methylation changes. These results support the potential identification of reliable and stable methylation biomarkers at genes for cancer diagnosis and prognosis.

EGFR Signaling Stimulates Autophagy to Regulate Stem Cell Maintenance and Lipid Homeostasis in the Drosophila Testis

Although typically upregulated upon cellular stress, autophagy can also be utilized under homeostatic conditions as a quality control mechanism or in response to developmental cues. Here, we report that autophagy is required for the maintenance of somatic cyst stem cells (CySCs) in the Drosophila testis. Disruption of autophagy in CySCs and early cyst cells (CCs) by the depletion of autophagy-related (Atg) genes reduced early CC numbers and affected CC function, resembling decreased epidermal growth factor receptor (EGFR) signaling. Indeed, our data indicate that EGFR acts to stimulate autophagy to preserve early CC function, whereas target of rapamycin (TOR) negatively regulates autophagy in the differentiating CCs. Finally, we show that the EGFR-mediated stimulation of autophagy regulates lipid levels in CySCs and CCs. These results demonstrate a key role for autophagy in regulating somatic stem cell behavior and tissue homeostasis by integrating cues from both the EGFR and TOR signaling pathways to control lipid metabolism.

Over-expression of EGFR regulated by RARA contributes to 5-FU resistance in colon cancer

A promising new strategy for cancer therapy is to target the autophagic pathway. However, comprehensive characterization of autophagy genes and their clinical relevance in cancer is still lacking. Here, we systematically characterized alterations of autophagy genes in multiple cancer lines by analyzing data from The Cancer Genome Atlas and CellMiner database. Interactions between autophagy genes and clinically actionable genes (CAGs) were identified by analyzing co-expression, protein-protein interactions (PPIs) and transcription factor (TF) data. A key subnetwork was identified that included 18 autophagy genes and 22 CAGs linked by 28 PPI pairs and 1 TF-target pair, which was EGFR targeted by RARA. Alterations in the expression of autophagy genes were associated with patient survival in multiple cancer types. RARA and EGFR were associated with worse survival in colorectal cancer patients. The regulatory role of EGFR in 5-FU resistance was validated in colon cancer cells in vivo and in vitro. EGFR contributed to 5-FU resistance in colon cancer cells through autophagy induction, and EGFR overexpression in 5-FU resistant colon cancer was regulated by RARA. The present study provides a comprehensive analysis of autophagy in different cancer cell lines and highlights the potential clinical utility of targeting autophagy genes.

Not the comfy chair! Cancer drugs that act against multiple active sites

Introduction: Discoveries of novel signal transduction pathways in the 1990s stimulated drug companies to develop small molecule tyrosine kinase and serine / threonine kinase inhibitors which were based on catalytic site inhibition. All kinases bind ATP and catalyze phosphate transfer and, therefore, inhibitors that block ATP binding and its metabolism would be predicted to have a known on-target specificity but were also likely to have many unknown or unrecognized targets due to similarities in all ATP binding pockets. This on-target off-target biology of kinase inhibitors, which exhibit a "signal" in the clinic, means that therapeutically valuable agents are acting through unknown biological processes to mediate their anti-tumor effects.Areas covered: This perspective discusses drug therapies whose actions cannot be explained by their actions on the original targeted kinase; it concludes with a methodology to screen for changes in cell signaling via in-cell western immunoblotting.Expert opinion: Most malignancies do not depend on survival signaling from one specific mutated proto-oncogene, especially for previously treated malignancies where multiple clonal variants of the primary tumor have evolved. Hence, the concept of a highly "personalized medicine" approach fails because it is unlikely that a specific therapy will kill all clonal variants of the tumor.

RCE‑4, a potential anti‑cervical cancer drug isolated from Reineckia carnea, induces autophagy via the dual blockade of PI3K and ERK pathways in cervical cancer CaSki cells

The steroidal saponin RCE‑4 (1β, 3β, 5β, 25S)‑spirostan‑1, 3‑diol 1‑[α‑L‑rhamnopyranosyl‑(1→2)‑β‑D‑xylopyranoside], isolated from Reineckia carnea, exerts significant anti‑cervical cancer activity by inducing apoptosis. The potential effect of RCE‑4 on proliferation inhibition and autophagy induction has rarely been studied. Therefore, the focus of the present study was to investigate the effects of RCE‑4 on proliferation, and to elucidate the detailed mechanisms involved in autophagy induction in cervical cancer cells. CaSki cells were treated with RCE‑4 or/and autophagy inhibitors, and the effect of RCE‑4 on cellular proliferation was assessed by MTT assay. The pro‑autophagic properties of RCE‑4 were subsequently confirmed using monomeric red fluorescent protein‑green fluorescent protein‑microtubule‑associated proteins 1A/1B light chain 3B (LC3) adenoviruses and CYTO‑ID autophagy assays, and by assessing the accumulation of lipid‑modified LC3 (LC3II). The mechanisms of RCE‑4‑induced autophagy were investigated by western blot analysis. The results demonstrated that inhibiting autophagy significantly promoted RCE‑4‑induced cell death, indicating that autophagy served a protective role following RCE‑4 treatment. In addition, RCE‑4‑induced autophagy was reflected by increased expression levels of the serine/threonine‑protein kinase ULK1, phosphorylated (p)‑ULK1, p‑Beclin‑1 and LC3II, the formation of autophagosomes and autolysosomes, and sequestosome 1 (p62) degradation. Subsequent analysis indicated that RCE‑4 activated the AMP‑activated protein kinase (AMPK) pathway by upregulating AMPK and p‑AMPK, and also inhibited the PI3K and extracellular signal‑regulated kinase (ERK) signaling pathways by downregulating p‑PI3K, p‑Akt, p‑mTOR, Ras, c‑Raf, p‑c‑Raf, dual specificity mitogen‑activated protein kinase kinase (MEK)1/2, p‑MEK1/2 and p‑Erk1/2. Additionally, with increased treatment times RCE‑4 may impair lysosomal cathepsin activity and inhibit autophagy flux by suppressing the expression of AMPK, p‑AMPK, ULK1, p‑ULK1 and p‑Beclin‑1, and upregulating that of p62. These results indicated that the dual RCE‑4‑induced inhibition of the PI3K and ERK pathways may result in a more significant anti‑tumor effect and prevent chemoresistance, compared with the inhibition of either single pathway; furthermore, dual blockade of PI3K and ERK, and the AMPK pathway may be involved in the regulation of autophagy caused by RCE‑4. Taken together, RCE‑4 induced autophagy to protect cancer cells against apoptosis, but AMPK‑mediated autophagy was inhibited in the later stages of RCE‑4 treatment. In addition, autophagy inhibition improved the therapeutic effect of RCE‑4. These data highlight RCE‑4 as a potential candidate for cervical cancer treatment.

XIAOPI formula promotes breast cancer chemosensitivity via inhibiting CXCL1/HMGB1-mediated autophagy

XIAOPI formula is a national approved drug prescribed to patients with high breast cancer risk. Previously we demonstrated that XIAOPI formula could inhibit breast cancer metastasis via suppressing CXCL1 expression, and postulated that "autophagy in cancer" might be one of its most core anti-cancer mechanisms. However, whether XIAOPI formula could be simultaneously applied with chemodrugs and their synergistic mechanisms are still remained unknown. In the present study, XIAOPI formula at non-cytotoxic doses could synergistically enhance the chemosensitivity of breast cancer cells MDA-MB-231 and MCF-7. We found that rapamycin-induced autophagy could reduce the chemosensitivity of breast cancer cells to XIAOPI formula, and the autophagy suppression and chemosensitizing activity of this formula was CXCL1-dependent. The evidence came from that XIAOPI formula was associated with a lower expression of CXCL1 combined with either rapamycin or taxol alone. Besides, the inhibitory effect of XIAOPI formula on the LC3-II and ABCG2 signals was weakened following CXCL1 over-expression, whereas P62 upregulation induced by XIAOPI formula was re-declined. A high throughput - qPCR (HT-qPCR) assay identified HMGB1 as the main autophagic target of XIAOPI formula in chemosensitizing breast cancer. and furhter validation suggested XIAOPI formula exerted chemosensitivity mainly via CXCL1/HMGB1 autophagic axis. Finally, we generated both mice and zebrafish xenotransplantation models bearing MDA-MB-231 breast cancer cells, and found that XIAOPI formula safely enhanced in vivo taxol chemosensitivity on breast cancer. Taken together, XIAOPI formula is a potential adjuvant drug via inhibiting CXCL1/HMGB1-mediated autophagy for breast cancer treatment with good safety.

The emergence of drug resistance to targeted cancer therapies: Clinical evidence

For many decades classical anti-tumor therapies included chemotherapy, radiation and surgery; however, in the last two decades, following the identification of the genomic drivers and main hallmarks of cancer, the introduction of therapies that target specific tumor-promoting oncogenic or non-oncogenic pathways, has revolutionized cancer therapeutics. Despite the significant progress in cancer therapy, clinical oncologists are often facing the primary impediment of anticancer drug resistance, as many cancer patients display either intrinsic chemoresistance from the very beginning of the therapy or after initial responses and upon repeated drug treatment cycles, acquired drug resistance develops and thus relapse emerges, resulting in increased mortality. Our attempts to understand the molecular basis underlying these drug resistance phenotypes in pre-clinical models and patient specimens revealed the extreme plasticity and adaptive pathways employed by tumor cells, being under sustained stress and extensive genomic/proteomic instability due to the applied therapeutic regimens. Subsequent efforts have yielded more effective inhibitors and combinatorial approaches (e.g. the use of specific pharmacologic inhibitors with immunotherapy) that exhibit synergistic effects against tumor cells, hence enhancing therapeutic indices. Furthermore, new advanced methodologies that allow for the early detection of genetic/epigenetic alterations that lead to drug chemoresistance and prospective validation of biomarkers which identify patients that will benefit from certain drug classes, have started to improve the clinical outcome. This review discusses emerging principles of drug resistance to cancer therapies targeting a wide array of oncogenic kinases, along with hedgehog pathway and the proteasome and apoptotic inducers, as well as epigenetic and metabolic modulators. We further discuss mechanisms of resistance to monoclonal antibodies, immunomodulators and immune checkpoint inhibitors, potential biomarkers of drug response/drug resistance, along with possible new therapeutic avenues for the clinicians to combat devastating drug resistant malignancies. It is foreseen that these topics will be major areas of focused multidisciplinary translational research in the years to come.

Mechanism of miR-107-targeting of regulator of G-protein signaling 4 in hepatocellular carcinoma

The aim of the present study was to investigate the mechanism of microRNA (miR)-107 in targeting regulator of G-protein signaling 4 (RGS4) in hepatic carcinoma. SK-HEP-1 cells were transfected with miR-107 mimics and control mimics. Reverse transcription-quantitative PCR was performed to determine the miR-107 expression levels, and following miR-107 upregulation, MTT, colony formation, transwell and wound-healing assays were performed to assess cell proliferation, colony-forming ability, invasion and migration, respectively. In addition, the effect of miR-107 upregulation on the cell cycle and apoptosis in SK-HEP-1 cells was evaluated using flow cytometry. Western blot analysis was performed to measure the protein expression levels of RGS4, epidermal growth factor receptor (EGFR), CXC chemokine receptor type 4 (CXCR4) and matrix metalloproteinase (MMP)-2 and −9. Expression level changes and the association between miR-107 and RGS4 in HCC cells were assessed using dual luciferase analysis. The results indicated that the overexpression of miR-107 in HCC cells suppressed cellular proliferation, invasion, migration and colony-forming ability, but promoted apoptosis and G₁ phase arrest. Furthermore, miR-107 mimics notably increased the protein expression level of RGS4, but significantly downregulated that of EGFR, CXCR4 and MMP-2 and −9. Together, these findings suggest that targeting this potential mechanism of miR-107 may be beneficial in the treatment of patients with HCC.

Targeting the complexity of Src signalling in the tumour microenvironment of pancreatic cancer: from mechanism to therapy

Pancreatic cancer, a disease with extremely poor prognosis, has been notoriously resistant to virtually all forms of treatment. The dynamic crosstalk that occurs between tumour cells and the surrounding stroma, frequently mediated by intricate Src/FAK signalling, is increasingly recognised as a key player in pancreatic tumourigenesis, disease progression and therapeutic resistance. These important cues are fundamental for defining the invasive potential of pancreatic tumours, and several components of the Src and downstream effector signalling have been proposed as potent anticancer therapeutic targets. Consequently, numerous agents that block this complex network are being extensively investigated as potential antiinvasive and antimetastatic therapeutic agents for this disease. In this review, we will discuss the latest evidence of Src signalling in PDAC progression, fibrotic response and resistance to therapy. We will examine future opportunities for the development and implementation of more effective combination regimens, targeting key components of the oncogenic Src signalling axis, and in the context of a precision medicine-guided approach.

What sustains the multidrug resistance phenotype beyond ABC efflux transporters? Looking beyond the tip of the iceberg

Identification of multidrug (MDR) efflux transporters that belong to the ATP-Binding Cassette (ABC) superfamily, represented an important breakthrough for understanding cancer multidrug resistance (MDR) and its possible overcoming. However, recent data indicate that drug resistant cells have a complex intracellular physiology that involves constant changes in energetic and oxidative-reductive metabolic pathways, as well as in the molecular circuitries connecting mitochondria, endoplasmic reticulum (ER) and lysosomes. The aim of this review is to discuss the key molecular mechanisms of cellular reprogramming that induce and maintain MDR, beyond the presence of MDR efflux transporters. We specifically highlight how cancer cells characterized by high metabolic plasticity - i.e. cells able to shift the energy metabolism between glycolysis and oxidative phosphorylation, to survive both the normoxic and hypoxic conditions, to modify the cytosolic and mitochondrial oxidative-reductive metabolism, are more prone to adapt to exogenous stressors such as anti-cancer drugs and acquire a MDR phenotype. Similarly, we discuss how changes in mitochondria dynamics and mitophagy rates, changes in proteome stability ensuring non-oncogenic proteostatic mechanisms, changes in ubiquitin/proteasome- and autophagy/lysosome-related pathways, promote the cellular survival under stress conditions, along with the acquisition or maintenance of MDR. After dissecting the complex intracellular crosstalk that takes place during the development of MDR, we suggest that mapping the specific adaptation pathways underlying cell survival in response to stress and targeting these pathways with potent pharmacologic agents may be a new approach to enhance therapeutic efficacy against MDR tumors.

Geniposide alleviates lipopolysaccharide-caused apoptosis of murine kidney podocytes by activating Ras/Raf/MEK/ERK-mediated cell autophagy

Proteinuria is one of the most important clinical features of nephrotic syndrome (NS). Injury of podocyte has been proved to contribute to the occurrence of proteinuria. This study explored the effects of geniposide (GEN) on lipopolysaccharide (LPS)-caused murine kidney podocyte MPC5 apoptosis and autophagy. Viability and apoptosis of MPC5 cells were respectively detected with the help of CCK-8 assay and Guava Nexin assay. 3-Methyladenine (3-MA) was used as an autophagy inhibitor, while rapamycin as autophagy activator. Si-Beclin-1 was transfected in MPC5 cells to down-regulate the expression of Beclin-1. We found that LPS stimulation significantly caused MPC5 cell viability reduction, apoptosis and autophagy (P < .05 or P < .01). GEN treatment remarkably alleviated the LPS-caused MPC5 cell viability reduction and apoptosis, but promoted cell autophagy (P < .05). Moreover, 3-MA incubation or si-Beclin-1 transfection notably weakened the effects of GEN on LPS-caused MPC5 cell apoptosis and autophagy (P < .05), while rapamycin had opposite effects (P < .05). Furthermore, GEN activated Ras/Raf/MEK/ERK pathway in LPS-treated MPC5 cells (P < .05). In conclusion, this research verified the protective effects of GEN on podocytes damage. GEN alleviates LPS-caused apoptosis of murine kidney podocytes by activating Ras/Raf/MEK/ERK-mediated cell autophagy. Highlights: LPS causes podocyte MPC5 apoptosis and autophagy. GEN alleviates LPS-caused MPC5 cell apoptosis, but promotes cell autophagy. 3-MA or si-Beclin-1 weakens the effects of GEN on LPS-treated MPC5 cells. Rapamycin strengthens the effects of GEN on LPS-treated MPC5 cells. GEN activates Ras/Raf/MEK/ERK pathway in LPS-treated MPC5 cells.