scholarly journals Autophagic Inhibition via Lysosomal Integrity Dysfunction Leads to Antitumor Activity in Glioma Treatment

2020 ◽  
Author(s):  
Hui-Yun Hwang ◽  
Yoon Sun Cho ◽  
Jin Young Kim ◽  
Ki Na Yun ◽  
Jong Shin Yoo ◽  
...  
Keyword(s):  
Cell Death ◽  
Xenograft Model ◽  
Autophagic Cell Death ◽  
Drug Candidate ◽  
Label Free ◽  
Glioma Xenograft ◽  
Liquid Chromatography Tandem Mass ◽  
Clinical Drug

Manipulating autophagy is a promising strategy for treating cancer as several autophagy inhibitors shown to induce autophagic cell death. One of these, autophagonizer (APZ), induces apoptosis-independent cell death by binding an unknown target via an unknown mechanism. To identify APZ targets we used a label-free drug affinity responsive target stability (DARTS) approach with a liquid chromatography/tandem mass spectrometry (LC-MS/MS) readout. Of 35 protein interactors, we identified Hsp70 as a key target protein of unmodified APZ in autophagy. Either APZ treatment or Hsp70 inhibition attenuates integrity of lysosomes, which leads to autophagic cell death exhibiting an excellent synergism with a clinical drug, temozolomide, in vitro, in vivo, and orthotropic glioma xenograft model. These findings demonstrate the potential of APZ to induce autophagic cell death and its development to combinational chemotherapeutic agent for glioma treatment. Collectively, our study demonstrated that APZ, a new autophagy inhibitor, can be used as a potent antitumor drug candidate to get over unassailable glioma and revealed a novel function of Hsp70 in lysosomal integrity regulation of autophagy.

scholarly journals Autophagic Inhibition via Lysosomal Integrity Dysfunction Leads to Antitumor Activity in Glioma Treatment

Cancers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 543 ◽  
Author(s):  
Hui-Yun Hwang ◽  
Yoon Sun Cho ◽  
Jin Young Kim ◽  
Ki Na Yun ◽  
Jong Shin Yoo ◽  
...  
Keyword(s):  
Cell Death ◽  
Xenograft Model ◽  
Autophagic Cell Death ◽  
Drug Candidate ◽  
Label Free ◽  
Glioma Xenograft ◽  
Liquid Chromatography Tandem Mass ◽  
Clinical Drug

Manipulating autophagy is a promising strategy for treating cancer as several autophagy inhibitors are shown to induce autophagic cell death. One of these, autophagonizer (APZ), induces apoptosis-independent cell death by binding an unknown target via an unknown mechanism. To identify APZ targets, we used a label-free drug affinity responsive target stability (DARTS) approach with a liquid chromatography/tandem mass spectrometry (LC–MS/MS) readout. Of 35 protein interactors, we identified Hsp70 as a key target protein of unmodified APZ in autophagy. Either APZ treatment or Hsp70 inhibition attenuates integrity of lysosomes, which leads to autophagic cell death exhibiting an excellent synergism with a clinical drug, temozolomide, in vitro, in vivo, and orthotropic glioma xenograft model. These findings demonstrate the potential of APZ to induce autophagic cell death and its development to combinational chemotherapeutic agent for glioma treatment. Collectively, our study demonstrated that APZ, a new autophagy inhibitor, can be used as a potent antitumor drug candidate to get over unassailable glioma and revealed a novel function of Hsp70 in lysosomal integrity regulation of autophagy.

scholarly journals Etamycin as a Novel Mycobacterium abscessus Inhibitor

2020 ◽  
Vol 21 (18) ◽  
pp. 6908
Author(s):  
Bui Thi Bich Hanh ◽  
Tae Ho Kim ◽  
June-Woo Park ◽  
Da-Gyum Lee ◽  
Jae-Sung Kim ◽  
...  
Keyword(s):  
Wild Type Strain ◽  
Standard Of Care ◽  
Mycobacterium Abscessus ◽  
Drug Candidate ◽  
Infection Model ◽  
Excellent Activity ◽  
Further Development ◽  
Clinical Drug

The increase in drug-resistant Mycobacterium abscessus, which has become resistant to existing standard-of-care agents, is a major concern, and new antibacterial agents are strongly needed. In this study, we introduced etamycin that showed an excellent activity against M. abscessus. We found that etamycin significantly inhibited the growth of M. abscessus wild-type strain, three subspecies, and clinical isolates in vitro and inhibited the growth of M. abscessus that resides in macrophages without cytotoxicity. Furthermore, the in vivo efficacy of etamycin in the zebrafish (Danio rerio) infection model was greater than that of clarithromycin, which is recommended as the core agent for treating M. abscessus infections. Thus, we concluded that etamycin is a potential anti-M. abscessus candidate for further development as a clinical drug candidate.

scholarly journals Targeting Positive Cofactor 4 induces autophagic cell death in MYC-expressing diffuse large B cell lymphoma

2021 ◽  
Author(s):  
Le Ma ◽  
Qiang Gong ◽  
Zelin Chen ◽  
Yu Wang ◽  
Xu Tan ◽  
...  
Keyword(s):  
Cell Death ◽  
B Cell ◽  
Molecular Mechanisms ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Autophagic Cell Death ◽  
Large B Cell Lymphoma ◽  
Large B Cell

Abstract Background: The MYC-expressing diffuse large B-cell lymphoma (DLBCL) is one of the refractory lymphomas. The pathogenesis of MYC-expressing DLBCL is still unclear, and there is a lack of effective therapy. In this study, we have explored the clinical significance and the molecular mechanisms of transcription co-activator 4 (PC4) in MYC-expressing DLBCL.Methods: We investigated PC4 expression in 54 cases of DLBCL patients’ tissues and matched normal specimens, and studied the molecular mechanisms of PC4 in MYC-expressing DLBCL both in vitro and in vivo.Results: We reported for the first time that targeting c-Myc could induce autophagic cell death in MYC-expressing DLBCL cell lines. We next characterized that PC4 was an upstream regulator of c-Myc, and PC4 was overexpressed in DLBCL and was closely related to clinical staging, prognosis and c-Myc expression. Further, our in vivo and in vitro studies revealed that PC4 knockdown could induce autophagic cell death of MYC-expressing DLBCL. And inhibition of c-Myc mediated aerobic glycolysis and activation of AMPK / mTOR signaling pathway were responsible for the autophagic cell death induced by PC4 knockdown in MYC-expressing DLBCL. Through the CHIP, DLRTM and EMSA assay, we also found that PC4 exerted its oncogenic functions by directly binding to c-Myc promoters.Conclusions: PC4 exerts its oncogenic functions by directly binding to c-Myc promoters. Inhibition of PC4 can induce autophagic cell death of MYC-expressing DLBCL. Our study provides novel insights into the functions and mechanisms of PC4 in MYC-expressing DLBCL, and suggests that PC4 might be a promising therapeutic target for MYC-expressing DLBCL.

DUSP4 inhibits autophagic cell death in PTC by inhibiting JNK-BCL2-Beclin1 signaling

2021 ◽  
Author(s):  
Huixiang He ◽  
zhenshuang Du ◽  
Jianqing Lin ◽  
Wenyi Wu ◽  
Yihuang Yu
Keyword(s):  
Cell Death ◽  
Specific Inhibitor ◽  
Autophagic Cell Death ◽  
Negative Regulator ◽  
Loss Of Function ◽  
In Vivo Assays ◽  
Prevention And Cure ◽  
The Relationship

DUSP4 is a prognostic marker and potential target of papillary thyroid carcinoma (PTC). However, the molecular mechanism underlying DUSP4-regulated PTC carcinogenesis is unclear. DUSP4 is a negative regulator of the autophagy promoter, JNK. This study aimed to explore the relationship between DUSP4 and JNK-mediated autophagic cell death in PTC. In this study, we explored the roles of DUSP4 in PTC using gain-of-function and loss-of-function assays. In addition, we further identified the significance of JNK-BCL2-Beclin1-autophagy signaling on DUSP4-regulated PTC carcinogenesis by combining DUSP4 silencing with JNK specific inhibitor (SP600125). We found that DUSP4 silencing promoted the phosphorylation of JNK and BCL2 in PTC cells and enhanced the release of Beclin1 from BCL2-Beclin1 complex. DUSP4 silencing promoted autophagy and death in PTC cells.The death and autophagy enhanced by DUSP4 silencing was reversed by JNK inhibitor. We further extended the in vitro experiments by injecting K1 cells transduced with DUSP4-silencing vector subcutaneously into nude mice. In vivo assays showed that DUSP4 silencing not only inhibited tumor growth, but also promoted JNK and BCL2 phosphorylation and LC3II expression.Overall, DUSP4 inhibits BCL2-Beclin1- autophagy signaling through negatively regulating JNK activity, thus inhibiting PTC oncogenesis.This study provides more potential clues for the prevention and cure of PTC.

scholarly journals CASK Silence Enhances Chemosensitivity of Hepatocellular Carcinoma Through activating Apoptosis, Inducing JNK/c-Jun-Mediated Autophagic Cell Death and Decreasing ABCG2

2021 ◽  
Author(s):  
BiSha Ding ◽  
Chang Bao ◽  
Luqi Jin ◽  
Liang Xu ◽  
Zhijun Dai ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Drug Resistance ◽  
Cell Death ◽  
Molecular Mechanisms ◽  
Autophagic Cell Death ◽  
Cell Counting ◽  
Advanced Hepatocellular Carcinoma ◽  
Sorafenib Treatment

Abstract Background: Advanced hepatocellular carcinoma (HCC) patients usually fail to be treated because of drug resistance, including sorafenib. Methods: The expression and prognostic role of calcium/calmodulin-dependent serine protein kinase (CASK) in HCC were assessed by combination of bioinformatic analysis and experimental validation. The effects of CASK in regulating proliferation, apoptosis and drug resistance of HCC cells in vitro and in vivo were investigated using gain- or loss-of-function strategies by performing lots of specific methods including Cell Counting kit-8 (CCK8), colony formation assay, flow cytometry, transmission electron microscopy, immunofluorescent confocal laser microscopy and tumor xenograft experiments, immunohistochemistry staining. Moreover, the underlying molecular mechanisms responsible for CASK’s functions in HCC were also explored. Results: Currently, we discovered that CASK was positively associated with sorafenib resistance of HCC in vitro and in vivo, and was significantly related with poor prognosis in HCC. Moreover, inhibition of CASK can increase the effect of sorafenib partially by promoting apoptosis and autophagy, while CASK overexpression presented the opposite results. Besides, all the pan-caspase inhibitor Z-VAD-FMK, autophagy inhibitor 3-Methyladenine (3-MA) and small interfering RNA (siRNA) of LC3B reversed CASK knockout-induced effects with sorafenib treatment, suggesting that both apoptosis and autophagy were involved in CASK-mediated above functions and autophagy played a pro-death role in this research. Intriguingly, similar results were observed in vivo. In molecular level, CASK knockout activated the c-Jun N-terminal kinase (JNK) pathway, and treatment with JNK inhibitor SP600125 or transiently transfected with si-JNK significantly attenuated CASK knockout-mediated autophagic cell death. Besides, knockout of CASK dramatically inhibited the expression of ATP binding cassette subfamily G member 2 (ABCG2) and reversed of multidrug-resistance (MDR) of HCC. Conclusions: Collectively, all these results together indicated that CASK might be a promising biomarker for HCC patients and a potential therapeutic target for relieving drug resistance of HCC.

STEM-15. SerpinB3 DRIVES CANCER STEM CELL SURVIVAL IN GLIOBLASTOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi24-vi24
Author(s):  
Adam Lauko ◽  
Soumya M Turaga ◽  
Josephine Volovetz ◽  
Defne Bayik ◽  
Shideng Bao ◽  
...  
Keyword(s):  
Cell Death ◽  
Protease Inhibitor ◽  
Cysteine Protease ◽  
Xenograft Model ◽  
Standard Of Care ◽  
Therapeutic Interventions ◽  
Cysteine Protease Inhibitor ◽  
Orthotopic Xenograft Model

Abstract Despite therapeutic interventions for glioblastoma (GBM), self-renewing, therapy-resistant populations of cells referred to as cancer stem cells (CSCs) drive recurrence. Previously, we identified the unique expression of junctional adhesion molecule-A (JAM-A) on CSCs and demonstrated that JAM-A is both necessary and sufficient for self-renewal and tumor growth. Moreover, we determined that JAM-A signals via Akt in GBM CSCs to sustain pluripotency transcription factor activity; however, the entire signaling network has yet to be fully elucidated. To further delineate this pathway, we immunoprecipitated JAM-A from patient-derived GBM CSCs and performed mass spectrometry to determine JAM-A binding proteins. This led to the identification of the cysteine protease inhibitor SerpinB3 as a putative JAM-A binding partner. Using in vitro CSC functional assays, we show that SerpinB3 is necessary for CSC maintenance and survival. In an in vivo orthotopic xenograft model, knockdown of SerpinB3 extended survival. Mechanistically, knockdown of SerpinB3 led to decreased expression of TGF-β, Myc, WNT, and Notch signaling, known regulators of the CSC state. Additionally, knockdown of SerpinB3 increases susceptibility to radiation therapy. SerpinB3 is essential for buffering cells against cathepsin-mediated cell death, and we found that elevated lysosomal membrane permeability after radiation leads to cathepsin release into the cytoplasm. As a result, SerpinB3 knockdown cells have a diminished capacity to inhibit cathepsin-driven cell death after radiation. The addition of the cathepsin inhibitor E64D partially rescues the SerpinB3 knockdown, however, SerpinB3 mutants that are unable to inhibit cathepsins fail to do the same. Taken together, our findings, identify a novel GBM CSC-specific survival mechanism involving a previously uninvestigated cysteine protease inhibitor, SerpinB3, and provide a potential target to increase the efficacy of standard of care GBM therapies against therapy-resistant CSCs.

Ophiopogonin D Attenuates Doxorubicin-Induced Autophagic Cell Death by Relieving Mitochondrial Damage In Vitro and In Vivo

2014 ◽  
Vol 352 (1) ◽  
pp. 166-174 ◽  
Author(s):  
Ying-Yu Zhang ◽  
Chen Meng ◽  
Xin-Mu Zhang ◽  
Cai-Hua Yuan ◽  
Ming-Da Wen ◽  
...  
Keyword(s):  
Cell Death ◽  
Mitochondrial Damage ◽  
Autophagic Cell Death

scholarly journals Fusobacterium nucleatum Promotes the Development of Ulcerative Colitis by Inducing the Autophagic Cell Death of Intestinal Epithelial

2020 ◽  
Vol 10 ◽  
Author(s):  
Wenhao Su ◽  
Yongyu Chen ◽  
Pan Cao ◽  
Yan Chen ◽  
Yuanmei Guo ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Cell Death ◽  
Epithelial Cell ◽  
Clinical Characteristics ◽  
Intestinal Epithelial Cell ◽  
Fusobacterium Nucleatum ◽  
Autophagic Cell Death ◽  
Intestinal Epithelial

There is a growing body of evidence which suggests that intestinal microbiota, especially Fusobacterium nucleatum (F. nucleatum), are associated with intestinal immune disease such as ulcerative colitis (UC). The mechanism by which F. nucleatum promotes intestinal epithelial cell (IEC) death remained undefined. Here, we investigated the potential mechanisms about how F. nucleatum aggravates IEC death in UC. We first detected the abundance of F. nucleatum in UC tissues and analyzed its relationship with the clinical characteristics of UC. Next, we explored whether F. nucleatum promotes intestinal epithelial cell death in vitro and in vivo. Furthermore, we extracted lipopolysaccharide (LPS) of the F. nucleatum and examined whether F. nucleatum exacerbates UC via LPS. Our results indicated that F. nucleatum was abundant in UC tissues and was correlated with clinical characteristics. In addition, we demonstrated that F. nucleatum and its LPS aggravated IEC death by promoted IEC autophagy. Furthermore, autophagy inhibitors, chloroquine (CQ), 3-methyladenine (3-MA) or Atg5 silencing prevented IEC death mediated by F. nucleatum, which suggests F. nucleatum may contribute to UC by activating autophagic cell death. All our results uncover a vital role of F. nucleatum in autophagic cell death and UC, giving rise to a new sight for UC therapy by inhibiting excessive IEC autophagy and autophagic cell death.

scholarly journals The In Vitro and In Vivo Anticancer Properties of Chalcone Flavokawain B through Induction of ROS-Mediated Apoptotic and Autophagic Cell Death in Human Melanoma Cells

Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2936
Author(s):  
You-Cheng Hseu ◽  
Yu-Chi Chiang ◽  
Yugandhar Vudhya Gowrisankar ◽  
Kai-Yuan Lin ◽  
Sheng-Teng Huang ◽  
...  
Keyword(s):  
Cell Death ◽  
Nude Mice ◽  
Melanoma Cell Line ◽  
Caspase 3 ◽  
Melanoma Cells ◽  
Human Melanoma ◽  
Autophagic Cell Death ◽  
Anticancer Properties

Melanoma is the most prevalent type of skin cancer with high mortality rates. This study demonstrates the in vitro and in vivo anticancer properties of chalcone flavokawain B (FKB) induced ROS-mediated apoptosis and autophagy in human melanoma (human epithelial melanoma cell line A375 and/or human skin lymph node derived melanoma cell line A2058) cells. Cell viability was calculated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the expression patterns of various apoptosis, autophagy-associated proteins were determined by Western blot methods. Annexin V was detected by flow cytometry, whereas acidic vesicular organelles (AVOs) and intracellular ROS levels were measured by fluorescence microscopy. The in vivo anticancer properties of FKB were evaluated by xenografting the A375 cells into nude mice. The results convey that FKB inhibited cell viability, B-Raf proto-oncogene, serine/threonine kinase (BRAF)/extracellular signal-regulated kinase (ERK) expression in human melanoma cells. Caspase-3 activation, poly (ADP-ribose) polymerase (PARP) cleavage pathway, and Bcl2 associated X (Bax)/B-cell lymphoma 2 (Bcl-2) dysregulation were involved in the execution of apoptosis. Moreover, FKB-induced autophagy was observed through increased microtubule-associated protein 1A/1B-light chain 3B (LC3-II) accumulation and AVOs formation, which was also associated with an increase in sequestosome 1 (SQSTM1/p62), decreased protein kinase B (AKT)/mammalian target of rapamycin (mTOR) expressions, and dysregulated Beclin-1/Bcl-2 levels. Autophagy inhibitors [3-methyladenine (3-MA)/chloroquine (CQ)] and LC3 silencing suppressed FKB-induced apoptosis by decreasing caspase-3 in melanoma cells. The antioxidant N-acetylcysteine (NAC) diminished FKB-induced apoptotic and autophagic cell death. However, the inhibition of apoptosis decreased FKB-induced autophagy (LC3-I/II). The in vivo study confirmed that FKB inhibited melanoma growth in A375-xenografted nude mice. This study concluded that FKB is critically associated with the execution and generation of ROS-modulated apoptotic and autophagic cell death of melanoma cells. FKB also repressed tumor growth in xenografted nude mice. Therefore, flavokawain B might be a potential anti-tumor agent in human melanoma treatment.

scholarly journals PCDH17 increases the sensitivity of colorectal cancer to 5-fluorouracil treatment by inducing apoptosis and autophagic cell death

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Shuiping Liu ◽  
Haoming Lin ◽  
Da Wang ◽  
Qiang Li ◽  
Hong Luo ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Death ◽  
Clinical Success ◽  
Dominant Role ◽  
Autophagic Cell Death ◽  
Jnk Activation ◽  
First Time ◽  
The Relationship

Abstract5-Fluorouracil (5-FU) is known as a first-line chemotherapeutic agent against colorectal cancer (CRC), but drug resistance occurs frequently and significantly limits its clinical success. Our previous study showed that the protocadherin 17 (PCDH17) gene was frequently methylated and functioned as a tumor suppressor in CRC. However, the relationship between PCDH17 and 5-FU resistance in CRC remains unclear. Here, we revealed that PCDH17 was more highly expressed in 5-FU-sensitive CRC tissues than in 5-FU-resistant CRC tissues, and high expression of PCDH17 was correlated with high BECN1 expression. Moreover, this expression profile contributed to superior prognosis and increased survival in CRC patients. Restoring PCDH17 expression augmented the 5-FU sensitivity of CRC in vitro and in vivo by promoting apoptosis and autophagic cell death. Furthermore, autophagy played a dominant role in PCDH17-induced cell death, as an autophagy inhibitor blocked cell death to a greater extent than the pancaspase inhibitor Z-VAD-FMK. PCDH17 inhibition by siRNA decreased the autophagy response and 5-FU sensitivity. Mechanistically, we showed that c-Jun NH2-terminal kinase (JNK) activation was a key determinant in PCDH17-induced autophagy. The compound SP600125, an inhibitor of JNK, suppressed autophagy and 5-FU-induced cell death in PCDH17-reexpressing CRC cells. Taken together, our findings suggest for the first time that PCDH17 increases the sensitivity of CRC to 5-FU treatment by inducing apoptosis and JNK-dependent autophagic cell death. PCDH17 may be a potential prognostic marker for predicting 5-FU sensitivity in CRC patients.

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