scholarly journals RET signalling provides tumorigenic mechanism and tissue specificity for AIP-related somatotrophinomas

Oncogene ◽  
2021 ◽  
Author(s):  
Angela R. Garcia-Rendueles ◽  
Miguel Chenlo ◽  
Fernando Oroz-Gonjar ◽  
Antonia Solomou ◽  
Anisha Mistry ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Loss Of Function ◽  
Apoptotic Pathway ◽  
Apoptosis Pathway ◽  
Pituitary Hyperplasia ◽  
Tumorigenic Mechanism ◽  
Induced Apoptosis

AbstractIt is unclear how loss-of-function germline mutations in the widely-expressed co-chaperone AIP, result in young-onset growth hormone secreting pituitary tumours. The RET receptor, uniquely co-expressed in somatotrophs with PIT1, induces apoptosis when unliganded, while RET supports cell survival when it is bound to its ligand. We demonstrate that at the plasma membrane, AIP is required to form a complex with monomeric-intracellular-RET, caspase-3 and PKCδ resulting in PIT1/CDKN2A-ARF/p53-apoptosis pathway activation. AIP-deficiency blocks RET/caspase-3/PKCδ activation preventing PIT1 accumulation and apoptosis. The presence or lack of the inhibitory effect on RET-induced apoptosis separated pathogenic AIP variants from non-pathogenic ones. We used virogenomics in neonatal rats to demonstrate the effect of mutant AIP protein on the RET apoptotic pathway in vivo. In adult male rats altered AIP induces elevated IGF-1 and gigantism, with pituitary hyperplasia through blocking the RET-apoptotic pathway. In females, pituitary hyperplasia is induced but IGF-1 rise and gigantism are blunted by puberty. Somatotroph adenomas from pituitary-specific Aip-knockout mice overexpress the RET-ligand GDNF, therefore, upregulating the survival pathway. Somatotroph adenomas from patients with or without AIP mutation abundantly express GDNF, but AIP-mutated tissues have less CDKN2A-ARF expression. Our findings explain the tissue-specific mechanism of AIP-induced somatotrophinomas and provide a previously unknown tumorigenic mechanism, opening treatment avenues for AIP-related tumours.

Identification of apoptotic genes mediating TGF-β/Smad3-induced cell death in intestinal epithelial cells using a genomic approach

2007 ◽  
Vol 292 (1) ◽  
pp. G28-G38 ◽  
Author(s):  
Yanna Cao ◽  
Lu Chen ◽  
Weili Zhang ◽  
Yan Liu ◽  
Harry T. Papaconstantinou ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Target Genes ◽  
Transforming Growth Factor ◽  
Intestinal Epithelial ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
Genomic Approach ◽  
Apoptotic Genes ◽  
Induced Apoptosis

Transforming growth factor (TGF)-β-dependent apoptosis is important in the elimination of damaged or abnormal cells from normal tissues in vivo. Previously, we have shown that TGF-β inhibits the growth of rat intestinal epithelial (RIE)-1 cells. However, RIE-1 cells are relatively resistant to TGF-β-induced apoptosis due to a low endogenous Smad3-to-Akt ratio. Overexpression of Smad3 sensitizes RIE-1 cells (RIE-1/Smad3) to TGF-β-induced apoptosis by altering the Smad3-to-Akt ratio in favor of apoptosis. In this study, we utilized a genomic approach to identify potential downstream target genes that are regulated by TGF-β/Smad3. Total RNA samples were analyzed using Affymetrix oligonucleotide microarrays. We found that TGF-β regulated 518 probe sets corresponding to its target genes. Interestingly, among the known apoptotic genes included in the microarray analyses, only caspase-3 was induced, which was confirmed by real-time RT-PCR. Furthermore, TGF-β activated caspase-3 through protein cleavage. Upstream of caspase-3, TGF-β induced mitochondrial depolarization, cytochrome c release, and cleavage of caspase-9, which suggests that the intrinsic apoptotic pathway mediates TGF-β-induced apoptosis in RIE-1/Smad3 cells.

scholarly journals SLC25A21 Suppresses Cell Growth in Bladder Cancer Via The Reactive Oxygen Species-Mediated Mitochondrion-Dependent Apoptosis Pathway

2021 ◽  
Author(s):  
Yong Wang ◽  
Jiawen Gao ◽  
Shasha Hu ◽  
Weiting Zeng ◽  
Hongjun Yang ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Treatment Strategies ◽  
Migration And Invasion ◽  
Loss Of Function ◽  
Apoptosis Pathway ◽  
Normal Tissues ◽  
Induced Apoptosis ◽  
New Diagnosis

Abstract Background: Bladder cancer (BCa) is a commonly diagnosed malignancy worldwide that has poor survival depending on its intrinsic biologic aggressiveness and a peculiar radio- and chemoresistance features. Gaining a better understanding of tumorigenesis and developing new diagnosis and treatment strategies for BCa is important for improving BCa clinical outcome. SLC25 family member 21 (SLC25A21), a carrier transporting C5-C7 oxodicarboxylates, has been reported to contribute to oxoadipate acidemia. However, the potential role of SLC25A21 in cancer remains absolutely unknown. Methods: The expression levels of SLC25A21 in BCa and normal tissues were examined by real-time PCR and immunohistochemistry. Gain-of- and loss-of-function experiments were performed to detect the biological functions of SLC25A21 in vitro and in vivo by CCK-8 assay, plate colony formation assay, cell migration, invasion assay and experimental animal models. The subcellular distribution of substrate mediated by SLC25A21, mitochondrial membrane potential and ROS production were assessed to explore the potential mechanism of SLC25A21 in BCa.Results: We found that the expression of SLC25A21 was downregulated in BCa tissues compared to normal tissues. A significant positive correlation between decreased SLC25A21 expression and poor prognosis was observed in BCa patients. Overexpression of SLC25A21 significantly inhibited cell proliferation, migration and invasion and induced apoptosis in vitro. Moreover, the enhanced SLC25A21 expression significantly suppressed tumor growth in a xenograft mouse model. Furthermore, we revealed that SLC25A21 suppressed BCa growth by inducing the efflux of mitochondrial α-KG to the cytosol, decreasing to against oxidative stress, and activating the ROS-mediated mitochondrion-dependent apoptosis pathway. Conclusions: Our findings provide the first link between SLC25A21 expression and BCa and demonstrate that SLC25A21 acts as a crucial suppressor in BCa progression, which may help to provide new targets for BCa intervention.

scholarly journals 12-Epi-Napelline Inhibits Leukemia Cell Proliferation via the PI3K/AKT Signaling Pathway In Vitro and In Vivo

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jia Han ◽  
Wei Hou ◽  
Bi-qing Cai ◽  
Fan Zhang ◽  
Jian-cai Tang
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Caspase 3 ◽  
Animal Experiments ◽  
Leukemia Cell ◽  
Tumor Model ◽  
Inhibitory Effect ◽  
Induced Apoptosis

This study aimed to investigate the inhibitory effect of 12-epi-napelline on leukemia cells and its possible mechanisms. The inhibitory effects of 12-epi-napelline on K-562 and HL-60 cells were evaluated using the CCK-8 assay, cell cycle arrest and apoptosis were detected by flow cytometry, and the expression of related proteins was measured by western blot. A K-562 tumor model was established to evaluate the antitumor effect of 12-epi-napelline in vivo. A reduction in leukemia cell viability was observed after treatment with 12-epi-napelline. It was determined that the cell cycle was arrested in the G0/G1 phase, and the cell apoptosis rate was increased. Moreover, caspase-3 and Bcl-2 were downregulated, whereas cleaved caspase-3 and caspase-9 were upregulated. Further study revealed that 12-epi-napelline could suppress the expression of PI3K, AKT, p-AKT, and mTOR. Insulin-like growth factor 1 (IGF-1) attenuated 12-epi-napelline-induced apoptosis and ameliorated the repression of PI3K, AKT, p-AKT, and mTOR by 12-epi-napelline. Animal experiments clearly showed that 12-epi-napelline inhibited tumor growth. In conclusion, 12-epi-napelline restrained leukemia cell proliferation by suppressing the PI3K/AKT/mTOR pathway in vitro and in vivo.

FLIPLong(L) and FLIPShort(S) Overexpression in the Human Myeloid Leukemia Cell Line ML-1 and Its Role in TRAIL [Tumor Necrosis Factor(TNF)-Related Apoptosis-Inducing Ligand] and TNFa Induced Apoptosis.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4378-4378
Author(s):  
Sudeshna Seal ◽  
Daniella B. Kerbauy ◽  
Vladimir Lesnikov ◽  
Nissa Abbasi-Shafer ◽  
H. Joachim Deeg
Keyword(s):  
Caspase 3 ◽  
Leukemia Cell ◽  
Leukemia Cell Line ◽  
Caspase 8 ◽  
Slight Reduction ◽  
Western Blots ◽  
Apoptosis Pathway ◽  
Induced Apoptosis ◽  
Active Caspase

Abstract TRAIL initiates activation of Caspase-8, which is blocked by the FLICE inhibitory protein (FLIP), resulting in resistance to apoptosis. Here we show that overexpression of FLIPL and FLIPS in ML1 cells, with low constitutive levels of FLIP, protects these cells against apoptosis induced by TRAIL, not only via Caspase-8 inhibition, but also via upregulation of anti-apoptotic molecules. Methods: 1) Apoptosis was determined by Annexin V/ 7-AAD following treatment with TRAIL (100–500ng/ml), or TNFa (20–100ng/ml) in ML1 cells transduced with FLIPL.GFP (green fluorescent protein), FLIPS.GFP or Neo.GFP (control). 2) Caspase-8, Caspase-3, Bid, Bcl-xL, XIAP, phosphorylated (P)-IKBa and P-Akt were determined by western blots. 3) Active Caspase-3 was determined using EnzChek Caspase-3 assay kit. Results: Both FLIPL and FLIPS transduction protected ML1 cells against apoptosis induced by TRAIL (300ng/ml), while no protection was observed in Neo.GFP cells. FLIPL had a more profound protective effect than FLIPS (Fig.1A). Both FLIPL and FLIPS, but not Neo.GFP, blocked Caspase-8 and Caspase-3 activation (Fig.1B); FLIPS cells showed two-fold higher levels of active Caspase-3 than FLIPL cells, consistent with higher apoptosis in FLIPS cells. Caspase-3 can be activated through Caspase-8 (extrinsic pathway) or via Caspase-8/Bid (intrinsic pathway). The latter was responsible for high active Caspase-3 levels in FLIPS cells as shown by the presence of cleaved Bid (t-Bid) (Fig.1B); cleavage of Bid was inhibited by combination of TRAIL and Z-IETD-FMK (Caspase-8 inhibitor). Anti-apoptotic molecules, including Bcl-xL, XIAP and FLIP are regulated by NF-kB and FLIP participates in an NF-kB auto-amplification loop. While Neo.GFP cells showed little Bcl-xL after 4h of TRAIL exposure and there was a twofold reduction in FLIPS cells, only a slight reduction of Bcl-xL was noted in FLIPL cells. FLIPL cells showed the lowest rates of apoptosis when exposed to TNFa and BMS543541, a specific inhibitor of IkB kinase (Fig. 1C). In the presence of BMS543541, phosphorylation of IkBa and levels of Bcl-xL and XIAP decreased in Neo.GFP and FLIPS but not in FLIPL cells. Additional data suggest that the PI3-kinase/Akt pathway is involved in constitutive NF-kB activation and differentially affected by FLIPL and FLIPS (Fig. 1D). Preliminary results in immunodeficient mice transplanted with transduced ML1 cells indicated the in vivo relevance of the differences between FLIPL and FLIPS with FLIPL cells engrafting earlier and showing earlier signs of sickness. Conclusions: FLIPL and FLIPS conferred resistance to TRAIL induced apoptosis but showed differential effects: Caspase-8/Bid was involved in the apoptosis pathway in FLIPS, but not in FLIPL cells. FLIPL cells’ resistance was due not only to caspase inhibition but to the recruitment of downstream anti-apoptotic pathways such as NF-kB and PI3K/Akt. In vivo data further substantiated the antiapoptotic/pro-survival behavior of FLIPL cells. Figure Figure

scholarly journals SLC25A21 Suppresses Cell Growth in Bladder Cancer via an Oxidative Stress-Mediated Mechanism

2021 ◽  
Vol 11 ◽  
Author(s):  
Yong Wang ◽  
Jiawen Gao ◽  
Shasha Hu ◽  
Weiting Zeng ◽  
Hongjun Yang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Bladder Cancer ◽  
Treatment Strategies ◽  
Migration And Invasion ◽  
Loss Of Function ◽  
Apoptosis Pathway ◽  
Normal Tissues ◽  
Induced Apoptosis

BackgroundBladder cancer (BCa) is a commonly diagnosed malignancy worldwide that has poor survival depending on its intrinsic biologic aggressiveness and a peculiar radio- and chemoresistance features. Gaining a better understanding of tumorigenesis and developing new diagnosis and treatment strategies for BCa is important for improving BCa clinical outcome. SLC25 family member 21 (SLC25A21), a carrier transporting C5-C7 oxodicarboxylates, has been reported to contribute to oxoadipate acidemia. However, the potential role of SLC25A21 in cancer remains absolutely unknown.MethodsThe expression levels of SLC25A21 in BCa and normal tissues were examined by real-time PCR and immunohistochemistry. Gain-of- and loss-of-function experiments were performed to detect the biological functions of SLC25A21 in vitro and in vivo by CCK-8 assay, plate colony formation assay, cell migration, invasion assay and experimental animal models. The subcellular distribution of substrate mediated by SLC25A21, mitochondrial membrane potential and ROS production were assessed to explore the potential mechanism of SLC25A21 in BCa.ResultsWe found that the expression of SLC25A21 was downregulated in BCa tissues compared to normal tissues. A significant positive correlation between decreased SLC25A21 expression and poor prognosis was observed in BCa patients. Overexpression of SLC25A21 significantly inhibited cell proliferation, migration and invasion and induced apoptosis in vitro. Moreover, the enhanced SLC25A21 expression significantly suppressed tumor growth in a xenograft mouse model. Furthermore, we revealed that SLC25A21 suppressed BCa growth by inducing the efflux of mitochondrial α-KG to the cytosol, decreasing to against oxidative stress, and activating the ROS-mediated mitochondrion-dependent apoptosis pathway.ConclusionsOur findings provide the first link between SLC25A21 expression and BCa and demonstrate that SLC25A21 acts as a crucial suppressor in BCa progression, which may help to provide new targets for BCa intervention.

scholarly journals Glutathione peroxidase-1 regulates ASK1-dependent apoptosis via interaction with TRAF2 in RIPK3-negative cancer cells

2021 ◽  
Author(s):  
Sunmi Lee ◽  
Eun-Kyung Lee ◽  
Dong Hoon Kang ◽  
Jiyoung Lee ◽  
Soo Hyun Hong ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Cancer Cells ◽  
Mammalian Cells ◽  
Apoptosis Pathway ◽  
Glutathione Peroxidase 1 ◽  
Peroxidase Enzyme ◽  
Thioredoxin 1 ◽  
Sequential Activation ◽  
Induced Apoptosis

AbstractGlutathione peroxidase (GPx) is a selenocysteine-containing peroxidase enzyme that defends mammalian cells against oxidative stress, but the role of GPx signaling is poorly characterized. Here, we show that GPx type 1 (GPx1) plays a key regulatory role in the apoptosis signaling pathway. The absence of GPx1 augmented TNF-α-induced apoptosis in various RIPK3-negative cancer cells by markedly elevating the level of cytosolic H2O2, which is derived from mitochondria. At the molecular level, the absence of GPx1 led to the strengthened sequential activation of sustained JNK and caspase-8 expression. Two signaling mechanisms are involved in the GPx1-dependent regulation of the apoptosis pathway: (1) GPx1 regulates the level of cytosolic H2O2 that oxidizes the redox protein thioredoxin 1, blocking ASK1 activation, and (2) GPx1 interacts with TRAF2 and interferes with the formation of the active ASK1 complex. Inducible knockdown of GPx1 expression impaired the tumorigenic growth of MDA-MB-231 cells (>70% reduction, P = 0.0034) implanted in mice by promoting apoptosis in vivo. Overall, this study reveals the apoptosis-related signaling function of a GPx family enzyme highly conserved in aerobic organisms.

scholarly journals Salmonella-Induced Caspase-2 Activation in Macrophages

2000 ◽  
Vol 192 (7) ◽  
pp. 1035-1046 ◽  
Author(s):  
Veronika Jesenberger ◽  
Katarzyna J. Procyk ◽  
Junying Yuan ◽  
Siegfried Reipert ◽  
Manuela Baccarini
Keyword(s):  
Type Iii Secretion ◽  
Caspase 3 ◽  
Secretion System ◽  
Caspase 1 ◽  
Chemical Inhibition ◽  
Induction Of Apoptosis ◽  
Caspase 2 ◽  
Induced Apoptosis

The enterobacterial pathogen Salmonella induces phagocyte apoptosis in vitro and in vivo. These bacteria use a specialized type III secretion system to export a virulence factor, SipB, which directly activates the host's apoptotic machinery by targeting caspase-1. Caspase-1 is not involved in most apoptotic processes but plays a major role in cytokine maturation. We show that caspase-1–deficient macrophages undergo apoptosis within 4–6 h of infection with invasive bacteria. This process requires SipB, implying that this protein can initiate the apoptotic machinery by regulating components distinct from caspase-1. Invasive Salmonella typhimurium targets caspase-2 simultaneously with, but independently of, caspase-1. Besides caspase-2, the caspase-1–independent pathway involves the activation of caspase-3, -6, and -8 and the release of cytochrome c from mitochondria, none of which occurs during caspase-1–dependent apoptosis. By using caspase-2 knockout macrophages and chemical inhibition, we establish a role for caspase-2 in both caspase-1–dependent and –independent apoptosis. Particularly, activation of caspase-1 during fast Salmonella-induced apoptosis partially relies on caspase-2. The ability of Salmonella to induce caspase-1–independent macrophage apoptosis may play a role in situations in which activation of this protease is either prevented or uncoupled from the induction of apoptosis.

Chemo-Preventive Potential of Falcarindiol-Enriched Fraction from Oplopanax elatus on Colorectal Cancer Interfered by Human Gut Microbiota

2019 ◽  
Vol 47 (06) ◽  
pp. 1381-1404 ◽  
Author(s):  
Jin Wang ◽  
Li Shao ◽  
Tai Rao ◽  
Wei Zhang ◽  
Wei-Hua Huang
Keyword(s):  
Gut Microbiota ◽  
Caspase 3 ◽  
Human Gut ◽  
Antiproliferative Effects ◽  
Human Gut Microbiota ◽  
Hct 116 ◽  
Oplopanax Elatus ◽  
Induced Apoptosis ◽  
Ht 29

Oplopanax elatus (Nakai) Nakai is an oriental herb, the polyyne-enriched fraction of which (PEFO) showed anticolorectal cancer (anti-CRC) effects. Other concomitant components, which are inevitably bio-transformed by gut microbiota after oral administration, might be interfere with the pharmacodynamics of polyynes. However, the influence of human gut microbiota on molecules from O. elatus possessing anticancer activity are yet unknown. In this study, the compounds in PEFO and PEFO incubated with human gut microbiota were analyzed and tentatively identified by HPLC-DAD-QTOF-MS. Two main polyynes ((3[Formula: see text]8[Formula: see text]-falcarindiol and oplopandiol) were not significantly decomposed, but some new unknown molecules were discovered during incubation. However, the antiproliferative effects of PEFO incubated with human gut microbiota for 72 h (PEFO I) were much lower than that of PEFO on HCT-116, SW-480, and HT-29 cells. Furthermore, PEFO possessed better anti-CRC activity in vivo, and significantly induced apoptosis of the CRC cells, which was associated with activation of caspase-3 according to the Western-blot results ([Formula: see text]). These results suggest anticolorectal cancer activity of polyynes might be antagonized by some bio-converted metabolites after incubation with human gut microbiota. Therefore, it might be better for CRC prevention if the polyynes could be orally administrated as purified compounds.

scholarly journals Apigenin Suppresses Angiogenesis by Inhibiting Tube Formation and Inducing Apoptosis

2016 ◽  
Vol 11 (10) ◽  
pp. 1934578X1601101
Author(s):  
Hyun Ju Kim ◽  
Mok-Ryeon Ahn
Keyword(s):  
Umbilical Vein ◽  
Chorioallantoic Membrane ◽  
Tube Formation ◽  
Anticancer Activities ◽  
Apoptotic Pathway ◽  
Inhibition Of Angiogenesis ◽  
Induced Apoptosis ◽  
Umbilical Vein Endothelial Cells

Apigenin has been reported to exert angiogenic and anticancer activities in vitro. The mechanism of inhibition of angiogenesis by apigenin, however, has not been well-established. In this study, we investigated whether apigenin not only inhibited tube formation but also induced apoptosis in human umbilical vein endothelial cells (HUVECs). Furthermore, strong antiangiogenic activity of apigenin was observed in the in vivo assay using chick embryo chorioallantoic membrane (CAM). We also analyzed changes in survival signals and the apoptotic pathway through Western blotting. The results indicate that apigenin exerts its antiangiogenic effects through induction of endothelial apoptosis.

scholarly journals L-securinine inhibits cell growth and metastasis of human androgen-independent prostate cancer DU145 cells via regulating mitochondrial and AGTR1/MEK/ERK/STAT3/PAX2 apoptotic pathways

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Dongxu Zhang ◽  
Houxian Liu ◽  
Binbin Yang ◽  
Jiasheng Hu ◽  
Yue Cheng
Keyword(s):  
Prostate Cancer ◽  
Protein Expression ◽  
Annexin V ◽  
Inhibitory Effect ◽  
Apoptotic Pathway ◽  
Growth Inhibitory ◽  
Du145 Cells ◽  
Apoptotic Pathways ◽  
Induced Apoptosis ◽  
Androgen Independent

Abstract The present study aims to evaluate the anticancer effect of L-securinine on androgen-independent prostate cancer (AIPC) DU145 cells. L-securinine (2.5, 5, and 10 μM) treatment for 24, 48 and 72 h displayed strong growth inhibitory effect on DU145 cells in a concentration and time-dependent fashion but has less toxicity toward normal androgen-dependent LNCaP cells. Hoechst 332582 staining of DU145 cells and Annexin V-FITC/ PI dual-labeling followed by flow cytometry assay identified that this growth inhibition by L-securinine would be due to the induction of apoptosis. Moreover Transwell assay revealed that L-securinine significantly inhibited the cell migration/invasion ability of DU145 cells. Furthermore, results of western blotting showed that the involvement of mitochondrial apoptotic pathway in the L-securinine-induced apoptosis of DU145 cell, as evidenced by an increase in the protein expression of Bax, cleaved caspase-9, cleaved caspase-3, cytosolic cytochrome c, and cleaved PARP, together with a unchanged cleaved caspase-8 and decreased Bcl-2 protein expression. Also, L-securinine-induced antimetastatic activity in DU145 cells was associated with decreased protein expression of MMP-2 and MMP-9 and concurrent reduction of VEGF. In addition, further studies revealed that L-securinine may inhibit the protein expression of AGTR1, p-MEK1/2, p-ERK1/2, p-STAT3, PAX2, and p-PAX2, while the expression of ERK1/2, MEK1/2, and STAT3 protein retains intact. These findings suggest that L-securinine may be a promising chemopreventive agent against AIPC.

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