Expression Of Bcl-xL Research Articles

Abstract 355: BCLxL inhibition enhances copanlisib response in colorectal cancer

Abstract Background: Anti-apoptotic signaling, including through BCLxL, is a potential mechanism of resistance to PI3K inhibition in PIK3CA mutant cancers. We have previously demonstrated enhanced activity of PI3K inhibition in combination with BCLxL inhibition in PIK3CA mutated colorectal cancer (CRC) models. Here we examine the potential impact of BCLxL expression in PIK3CA mutant CRCs and the mechanism of treatment response with the combination of copanlisib and navitoclax. Methods: PIK3CA mutant CRCs were identified within TCGA colorectal adenocarcinoma data set and two cohorts were generated based on BCL2L1 (gene that encodes protein BCLxL) expression. Differentially expressed genes and gene set enrichment analysis were performed. CRC cell lines SW48 and SW48PK (Horizon Discovery, SW48 with a PIK3CAH1047R/+ mutation) were treated with copanlisib (copan) (1-100 nM) and navitoclax (250 nM). Immunoblotting was performed quantified using ImageJ to evaluate PI3K and apoptotic signaling. Flow cytometry using annexin V and propidium iodide (PI) was performed as a measure of apoptosis. Immunohistochemistry (IHC) using Ki67 was performed as a measure of cell proliferation on SW48PK xenografts and quantified as percent positive nuclei at 40x field of view (FOV). Results: Two datasets comprised of PIK3CA mutant CRC patients with either high or low BCL2L1 expression containing 39 and 47 patients, respectively, were used in the TGCA analysis. There was no difference in age, gender, or staging between these two datasets. An increase in DNA repair (false discovery rate q-value= 0.034) and interferon alpha signaling pathways (q= 0.022) was seen in PIK3CA mutant and high BCL2L1 expression compared to PIK3CA mutant and low BCL2L1 expression patients. PIK3CA mutant patients with low expression of BCL2L1 had a greater disease-free and overall survival (p= 0.037 and p= 0.042, respectively). Combination of copan and navitoclax treatment of the SW48 and SW48PK cell lines resulted in a reduction in activated ribosomal protein S6 (pRPS6) as compared with control or navitoclax alone at both 6 and 24. Cleaved PARP increased in SW48PK cells treated with 100 nM copan plus navitoclax versus control at both 6 and 24 hour timepoints (p= 0.03, p= 0.049). SW48 and SW48PK cells that were treated with copan and navitoclax for 24 hours had an increase in annexin v, a marker for apoptosis, compared to cells treated with control or single agents. In SW48PK xenografts, a significant reduction in Ki67 percent positive nuclei was seen in combination compared to control (median percent positive nuclei: 20.5, control: 33.2, p<0.001). Conclusions: High BCLxL expression is a sign of poor prognosis for PIK3CA mutant CRC. Inhibiting BCLxL can enhance the sensitivity of PI3K inhibition in PIK3CA mutant cancers and deserves further investigation clinically. Citation Format: Alexa E. Schmitz, Rebecca A. DeStefanis, Alyssa K. DeZeeuw, Autumn M. Olson, Anna L. Lippert, Kennedy J. Maduscha, Katherine A. Johnson, Sean Kraus, Cheri A. Pasch, Dustin A. Deming. BCLxL inhibition enhances copanlisib response in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 355.

Abstract 5991: Improved venetoclax therapy by a novel conjugate with artemisinin by NOXA-mediated reduction of Mcl-1 and cyclin D1 protein in myeloid leukemia cells

Abstract Evasion of apoptosis is crucial for the growth, survival and chemoresistance of myeloid leukemia. The Bcl-2 selective inhibitor venetoclax is the only apoptosis inducer approved for clinical use. Venetoclax in combination with hypomethylating agents or low-dose cytarabine has now become the standard care for elderly AML patients. However, a sizeable fraction of patients are either refractory to venetoclax combination therapy or ultimately relapse. High or induced expression of Mcl-1 and Bcl-xL mediates venetoclax resistance. Previously we reported that artemisinin enhances venetoclax apoptosis induction by degrading Mcl-1 through NOXA induction. We designed a novel conjugate A1 of venetoclax with dihydroartemisinin. A1 shows dual functions of inhibiting Bcl-2 and inducing NOXA. A1 treatment releases Bim from both Bcl-2 and Mcl-1, further degrades Mcl-1 protein, and presents ten-fold stronger apoptotic induction ability in venetoclax insensitive cells. Acquired increase of Mcl-1 protein was observed in venetoclax resistant MOLM-13/VEN cells, which are sensitive to A1-induced apoptosis. In Bcl-xL expressing venetoclax refractory leukemia cells A1 obtains a new mechanism of inhibiting cell cycling by downregulating cyclin D1 through a new NOXA/cyclin D1 cascade, mediated through the endoperoxide moiety of artemisinin and intracellular iron, independent of Bcl-2 inhibition. We reveal a new compound A1 overcoming venetoclax resistance by NOXA-mediated degradation of Mcl-1 and cyclin D1 protein. Citation Format: Jingyi Zhang, Zhenwei Zhang, Samuel Waxman, Linxiang Zhao, Yongkui Jing. Improved venetoclax therapy by a novel conjugate with artemisinin by NOXA-mediated reduction of Mcl-1 and cyclin D1 protein in myeloid leukemia cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5991.

Abstract 7579: Dual inhibition of enhancer of zeste homolog 1 2 induces pyroptosis, modulates oncogenic signaling pathways & sensitizes hepatocellular carcinoma to valemetostat & docetaxel treatments

Abstract HCC is a global health concern, with chemotherapy resistance and patient recurrence posing significant challenges to liver cancer treatment. EZH2 is a crucial part of the polycomb repressive complex 2 (PRC2). It, along with its homolog EZH1, is a focus for cancer therapeutic targets. Dysregulation of EZH1/2 can cause cancer development due to significant changes in geneexpression. The current study aims to investigate the interaction between EZH1/2 and oncogenic signals responsible for HCC progression and pyroptosis induction. Two cell lines, HepG2 and SK-Hep1, were subjected to two FDA-approved drugs, Valemetostat (Val) and Docetaxel (Doc), to determine the impact of EZH1/2 on tumorigenicity and drug resistance. The WST-1 assay was utilized to gauge cell proliferation. The results indisputablydemonstrated a synergistic effect of the drugs after 48 h of treatment. The inhibition of viability was attributed to apoptosis induction in both tested cell lines, and the maximum effect was observed in the combined treatment as compared to either the control or each drug alone. Furthermore, our datashowed activation of caspase-3, upregulation of BAX, indicating apoptotic induction, and downregulation of Bcl-2, Bcl-XL, AKT, S6k, oncogenic β-catenin, and Stat3 protein expression levels, suggesting a modulation of oncogenic signaling pathways at the protein level. After 24 h of Val/Doc treatment, pyroptosis was observed, characterized by cell swelling and bubbles on themembrane and a significant release of lactate dehydrogenase, indicating pyroptotic cell cytotoxicity. The antitumor effects and pyroptosis were enhanced by using a dual inhibitor, UNC1999, for EZH1/2, resulting in a marked increase in the sensitivity of tested cells to the Val/Doc treatment invitro. The present study unequivocally demonstrated that dual inhibition of EZH1/2 acts as a potent sensitizer of HCC cells to Val/Doc treatment, which might be a promising therapeutic approach for inducing cellular pyroptosis in HCC cell lines. Citation Format: Asmaa Elkhder Harira, Adham Maher, Ahmed Sultan. Dual inhibition of enhancer of zeste homolog 1 2 induces pyroptosis, modulates oncogenic signaling pathways & sensitizes hepatocellular carcinoma to valemetostat & docetaxel treatments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7579.

Abstract 7589: The novel complex delivery system of C-phycocyanin-loaded klebsiella pneumoniabacterial ghost induces apoptosis and sensitizes non-small cell lung cancer cell lines to doxorubicin

Abstract Lung cancer is a significant cause of cancer-related deaths worldwide, with a high incidence rate, poor prognosis, aggressiveness, and a lack of effective treatment options. The present study has brought together two FDA-approved drugs with antineoplastic properties to create a complex that promises to revolutionize the treatment of Non-Small Cell Lung Cancer (NSCLC). By combining C-Phycocyanin extract (PCE), a pigment-protein complex synthesized by blue-green microalgae platensis, with the immunostimulatory doxorubicin (DOX) loaded Bacterial Ghosts (BGs), the present study aims to achieve enhanced dual-chemotherapy and remarkable inhibition of DOX-chemoresistance. The BG delivery system uses purified bacterial cell evacuation and safe confirmed Klebsiella pneumoniae BGs (KPBG) for safe and effective delivery, overcoming issues with resistance and poor delivery. The complex delivery system of KPBG-PCE/DOX was tested on two NSCLC cell lines, wild-P53, A549, and mutant-P53, NCI/H358, respectively. Our data showed that the loaded combined treatment significantly induced morphological changes with signs of apoptosis induction in the tested cell lines compared with the control. The WST-1 assay was used to evaluate cell proliferation. Data indicates that PCE and DOX have a synergistic effect at low concentrations when loaded on KPBGs for a constant count of BGs CFU/ml after 48 h of treatment. The viability inhibition and apoptosis induction of A549 and NCI/H358 cells were amplified in the combined treatment of 48 h compared to the control or either each drug alone. At the protein levels, our data showed activation of caspase-3, upregulation of BAX, and downregulation of Bcl-2, Bcl-XL, m-TOR, S6k, oncogenic β-catenin, and cyclin-D1 protein expression levels after treatment with (KPBG-PCE/DOX) for 48 h, indicating apoptotic induction and modulating oncogenic signaling pathways. In conclusion, the current study presents a promising outcome of a synergistic delivery system of KPBG-PCE/DOX that can inhibit lung cancer cell line proliferation, induce apoptosis, and increase cell sensitivity to DOX. The KPBG delivery system offers an appealing approach for a successful combination of targeted therapy for lung cancer. Citation Format: Basma Adel Elsayed Abdelaziz, Hoda Eid Mahmoud, Omayma Mohamed Sadek, Ahmed Samir Sultan. The novel complex delivery system of C-phycocyanin-loaded klebsiella pneumoniabacterial ghost induces apoptosis and sensitizes non-small cell lung cancer cell lines to doxorubicin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7589.

Evaluation of Efficacy of Curcumin and Caffeic Acid Phenethyl Ester in Breast Cancer by Preclinical Studies.

CAPE and curcumin are a class of phenolics. While curcumin is obtained from turmeric, CAPE is found in Baccharis sarothroides and Populus deltoides. Both agents are reported to produce activities in some cancer types. The combined and comparative effects of the two agents in breast cancer have not yet reported. We evaluated the potential of CAPE and curcumin in both in vitro and in vivo breast cancer models. Human breast cancer cell lines, MDA-MB-231 and MCF-7, were exposed to CAPE and curcumin, followed by functional assays such as cell cytotoxicity, cell proliferation and colony formation, cell cycle, mitochondrial membrane potential, apoptosis, and monodansylcadaverine (MDC) staining for autophagy. Computational analyses and mouse models were also used. Employing computational analyses, both agents were found to exhibit drug-like properties. Both molecules interacted with the key molecules of the NF-κB pathway. CAPE and curcumin inhibited cell proliferation, colony formation, and invasion, triggering apoptosis in breast cancer cells. CAPE was found to be more effective than curcumin. Two agents working together were more effective than each agent working alone. Both agents suppressed the expression of survivin, Bcl-xL and GLUT-1. The level of cleaved PARP was increased by both agents. Both phenolics observed an induction in ROS generation. Further, both molecules triggered a dissipation in mitochondrial membrane potential. In mice models implanted with Ehrlich-Lettre ascites carcinoma (EAC) cells, both drugs inhibited the growth of the tumour. The phenolics also modulated the metabolic parameters in tumour-bearing mice. The observations suggest that the combination of curcumin plus CAPE may be better in comparison to individual molecules. Other: The study opens a window for analysing the efficacy of the combination of CAPE and curcumin in animal studies. This will provide a basis for examining the combined efficacy of two agents in a clinical trial.

LncRNA SNHG11 promotes malignant progression of colorectal cancer cells through the PI3K/Akt/mTOR signaling pathway

Objective: To investigate the effects of lncRNA SNHG11 on proliferation, migration, invasion and apoptosis of colorectal cancer cancer cells and possible mechanisms. Methods: qRT-PCR was performed to detect the expression level of lncRNA SNHG11 in colorectal cancer tissues and its related cell lines. The correlation between SNHG11 expression and clinical prognosis of patients was assessed by bioinformatics techniques. Cultured CRC cell lines were transfected with shCtrl (shCtrl group), shSNHG11#1 (shSNHG11#1 group), shSNHG11#2 (shSNHG11#2 group), Control cDNA (Control cDNA group), and SNHG11 cDNA (SNHG11 cDNA), respectively. Thiazolyl blue (MTT), clone formation assay, Transwell assay, cell scratch assay, and flow cytometry were used to detect the proliferation, migration, invasion, and apoptosis of CRC cells in each group. Western protein blotting was used to detect the expression of relevant proteins in each group, and the effect of lncRNA SNHG11 knockdown on the growth of tumour cells in vivo was analysed by nude mice tumouring assay. Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signalling pathway inhibitor LY294002 was used for rescue experiments. Results: The expression of lncRNA SNHG11 was significantly higher in colorectal cancer cells and tissues than in normal tissues (P<0.05). Survival analysis showed that the expression level of SNHG11 was not statistically associated with CRC survival (P>0.05). shSNHG11#2 group compared with shCtrl group. MTT OD490/570 values decreased, the number of CRC cell clones decreased, the number of Transwell cells decreased, the area of cell scratch decreased, and the apoptosis rate increased (P<0.05). The mesenchymal markers matrix metalloproteinase (MMP9), N-cadherin and vimentin were significantly reduced, and the expression of the epithelial marker E-cadherin was upregulated. The expression of anti-apoptotic proteins Bcl-2 and Bcl-xl was decreased, and the expression of pro-apoptotic protein Bax was increased (P<0.05).In vivo experiments showed that lncRNA SNHG11 knockdown inhibited the growth of colorectal cancer cells, and the expression of Ki67 was reduced in tumours (P<0.05). LncRNA SNHG11 knockdown inhibited the expression of p-PI3K, p-Akt and p-mTOR.The PI3K/Akt/mTOR signaling pathway inhibitor LY294002 was able to restore the malignant cytological progression of colorectal cancer cells induced by the overexpression of lncRNA SNHG11. Conclusions: LncRNA SNHG11 is highly expressed in colorectal cancer. lncRNA SNHG11 can promote the malignant progression of colorectal cancer cells by regulating the PI3K/Akt/mTOR signaling pathway, and this finding provides a new theoretical basis for targeted therapy of colorectal cancer.

YES1 as a potential target to overcome drug resistance in EGFR-deregulated non-small cell lung cancer.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) such as gefitinib and osimertinib have primarily been used as first-line treatments for patients with EGFR-activating mutations in non-small cell lung cancer (NSCLC). Novel biomarkers are required to distinguish patients with lung cancer who are resistant to EGFR-TKIs. The aim of the study is to investigate the expression and functional role of YES1, one of the Src-family kinases, in EGFR-TKI-resistant NSCLC. YES1 expression was elevated in gefitinib-resistant HCC827 (HCC827/GR) cells, harboring EGFR mutations. Moreover, HCC827/GR cells exhibited increased reactive oxygen species (ROS) levels compared to those of the parent cells, resulting in the phosphorylation/activation of YES1 due to oxidation of the cysteine residue. HCC827/GR cells showed elevated expression levels of YES1-associated protein 1 (YAP1), NF-E2-related factor 2 (Nrf2), cancer stemness-related markers, and antioxidant proteins compared to those of the parent cells. Knockdown of YES1 in HCC827/GR cells suppressed YAP1 phosphorylation, leading to the inhibition of Bcl-2, Bcl-xL, and Cyclin D1 expression. Silencing YES1 markedly attenuated the proliferation, migration, and tumorigenicity of HCC827/GR cells. Dasatinib inhibited the proliferation of HCC827/GR cells by targeting YES1-mediated signaling pathways. Furthermore, the combination of gefitinib and dasatinib demonstrated a synergistic effect in suppressing the proliferation of HCC827/GR cells. Notably, YES1- and Nrf2-regulated genes showed a positive regulatory relationship in patients with lung cancer and in TKI-resistant NSCLC cell lines. Taken together, these findings suggest that modulation of YES1 expression and activity may be an attractive therapeutic strategy for the treatment of drug-resistant NSCLC.

Fucoxanthin induces human melanoma cytotoxicity by thwarting the JAK2/STAT3/BCL-xL signaling axis.

Melanoma is the most lethal skin malignancy. Fucoxanthin is a marine carotenoid with significant anticancer activities. Intriguingly, Fucoxanthin's impact on human melanoma remains elusive. Signal Transducer and Activator of Transcription 3 (STAT3) represents a promising target in cancer therapy due to its persistent activation in various cancers, including melanoma. Herein, we revealed that Fucoxanthin is cytotoxic to human melanoma cell lines A2758 and A375 while showing limited cytotoxicity to normal human melanocytes. Apoptosis is a primary reason for Fucoxanthin's melanoma cytotoxicity, as the pan-caspase inhibitor z-VAD-fmk drastically abrogated Fucoxanthin-elicited clonogenicity blockage. Besides, Fucoxanthin downregulated tyrosine 705-phosphorylated STAT3 (p-STAT3 (Y705)), either inherently present in melanoma cells or inducible by interleukin 6 (IL-6) stimulation. Notably, ectopic expression of STAT3-C, a dominant-active STAT3 mutant, abolished Fucoxanthin-elicited melanoma cell apoptosis and clonogenicity inhibition, supporting the pivotal role of STAT3 blockage in Fucoxanthin's melanoma cytotoxicity. Moreover, Fucoxanthin lowered BCL-xL levels by blocking STAT3 activation, while ectopic BCL-xL expression rescued melanoma cells from Fucoxanthin-induced killing. Lastly, Fucoxanthin was found to diminish the levels of JAK2 with dual phosphorylation at tyrosine residues 1007 and 1008 in melanoma cells, suggesting that Fucoxanthin impairs STAT3 signaling by blocking JAK2 activation. Collectively, we present the first evidence that Fucoxanthin is cytotoxic selectively against human melanoma cells while sparing normal melanocytes. Mechanistically, Fucoxanthin targets the JAK2/STAT3/BCL-xL antiapoptotic axis to provoke melanoma cell death. This discovery implicates the potential application of Fucoxanthin as a chemopreventive or therapeutic strategy for melanoma management.

Kojic acid inhibits pig sperm apoptosis and improves capacitated sperm state during liquid preservation at 17°C.

The parameters of sperm apoptosis and capacitation during liquid storage at 17°C can indicate the quality of pig sperm and the potential development of early embryos. However, the effect of kojic acid (KA) on semen preservation and its mechanism has not been fully understood. In this study, we discovered that adding KA to the diluent improved the antioxidant capacity of sperm mitochondria, maintained the normal structure of sperm mitochondria, and reduced sperm apoptosis. Western blot analysis revealed that KA prevented the release of Cytochrome c from mitochondria to the cytoplasm, reduced the expression of pro-apoptosis proteins cleaved Caspase-3 and cleaved Caspase-9, and increased the expression of the antiapoptosis protein Bcl-XL. Furthermore, KA also enhanced the motility parameters, oxidative phosphorylation level, adenosine triphosphate level, and protein tyrosine phosphorylation of capacitated sperm, while preserving the acrosome integrity and plasma membrane integrity of capacitated sperm. In conclusion, this study offers new insights into the molecular mechanism of how KA inhibits porcine sperm apoptosis and improves capacitated sperm parameters. Additionally, it suggests that KA can serve as an alternative to antibiotics.

Structural Insights into the Interaction between the C-Terminal-Deleted BH3-like Motif Peptide of Hepatitis B Virus X Protein and Bcl-xL.

Hepatitis B virus X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma (HCC) associated with hepatitis B virus (HBV) infection. The full-length HBx protein interacts with Bcl-xL and is involved in the HBV replication and cell death processes. The three hydrophobic residues Trp120, Leu123, and Ile127 of the HBx BH3-like motif are essential for the Bcl-xL-binding. On the other hand, various lengths of C-terminal-truncated HBx mutants are frequently detected in HCC tissues, and these mutants, rather than the full-length HBx, appear to be responsible for HCC development. Notably, the region spanning residues 1-120 of HBx [HBx(1 and 120)] has been strongly associated with an increased risk of HCC development. However, the mode of interaction between HBx(1-120) and Bcl-xL remains unclear. HBx(1-120) possesses only Trp120 among the three hydrophobic residues essential for the Bcl-xL-binding. To elucidate this interaction mode, we employed a C-terminal-deleted HBx BH3-like motif peptide composed of residues 101-120. Here, we present the NMR complex structure of Bcl-xL and HBx(101-120). Our results demonstrate that HBx(101-120) binds to Bcl-xL in a weaker manner. Considering the high expression of Bcl-xL in HCC cells, this weak interaction, in conjunction with the overexpression of Bcl-xL in HCC cells, may potentially contribute to HCC development through the interaction between C-terminal-truncated HBx and Bcl-xL.

Protection from cisplatin-induced hearing loss with lentiviral vector-mediated ectopic expression of the anti-apoptotic protein BCL-XL

Cisplatin is a highly effective chemotherapeutic agent, but it can cause sensorineural hearing loss (SNHL) in patients. Cisplatin-induced ototoxicity is closely related to the accumulation of reactive oxygen species (ROS) and subsequent death of hair cells (HCs) and spiral ganglion neurons (SGNs). Despite various strategies to combat ototoxicity, only one therapeutic agent has thus far been clinically approved. Therefore, we have developed a gene therapy concept to protect cochlear cells from cisplatin-induced toxicity. Self-inactivating lentiviral (LV) vectors were used to ectopically express various antioxidant enzymes or anti-apoptotic proteins to enhance the cellular ROS scavenging or prevent apoptosis in affected cell types. In direct comparison, anti-apoptotic proteins mediated a stronger reduction in cytotoxicity than antioxidant enzymes. Importantly, overexpression of the most promising candidate, Bcl-xl, achieved an up to 2.5-fold reduction in cisplatin-induced cytotoxicity in HEI-OC1 cells, phoenix auditory neurons, and primary SGN cultures. BCL-XL protected against cisplatin-mediated tissue destruction in cochlear explants. Strikingly, invivo application of the LV BCL-XL vector improved hearing and increased HC survival in cisplatin-treated mice. In conclusion, we have established a preclinical gene therapy approach to protect mice from cisplatin-induced ototoxicity that has the potential to be translated to clinical use in cancer patients.

GZ17-6.02 interacts with bexarotene to kill mycosis fungoides cells.

GZ17-6.02, composed of curcumin, harmine and isovanillin, has undergone phase I evaluation in patients with solid tumors (NCT03775525) with an RP2D of 375 mg PO BID. The biology of GZ17-6.02 in malignant T cells and in particular those derived from mycosis fungoides (MF) patients, has not been studied. GZ17-6.02 alone and in combination with standard-of-care agents was effective in killing MF cells. All three components are necessary for optimal killing of MF cells. GZ17-6.02 activated ATM, the AMPK, NFκB and PERK and inactivated ERK1/2, AKT, ULK1, mTORC1, eIF2α, and reduced the expression of BCL-XL and MCL1. GZ17-6.02 increased ATG13 S318 phosphorylation and the expression of Beclin1, ATG5, BAK and BIM. GZ17-6.02 in a dose-dependent fashion enhanced autophagosome formation and autophagic flux, and tumor cell killing. Signaling by ATM and AMPK were both required for efficient killing but not for the dose-response effect whereas ER stress (eIF2α) and macroautophagy (Beclin1, ATG5) were required for both efficient killing and the dose-response. Knock down of the death receptor CD95 reduced killing by ~20% and interacted with autophagy inhibition to further reduce killing, collectively, by ~70%. Inhibition of autophagy and knock down of death-mediators downstream of the mitochondrion, AIF and caspase 3, almost abolished tumor cell killing. Hence in MF cells, GZ17-6.02 is a multi-factorial killer, utilizing ER stress, macroautophagy, death receptor signaling and directly causing mitochondrial dysfunction.

Different concentrations of betaxolol switch cell fate between necroptosis, apoptosis, and senescence in human corneal stromal cells

Betaxolol is commonly used to manage glaucoma in clinical practice. However, its long-term use may damage the cornea. Thus, the cytotoxicity and mechanisms of betaxolol in human corneal stromal cells (HCSCs) warrant further study. In this study, we used in vitro HCSCs and in vivo rabbit corneal models to investigate betaxolol cytotoxic effects and mechanism of action. At near-clinical concentrations (0.28% and 0.14%), betaxolol inhibited caspase-8 activity, activated receptor-interacting protein kinase (RIPK)1, RIPK3, and mixed-spectrum kinase-like domain (MLKL), and phosphorylated MLKL to induce necroptosis in HCSCs. Similarly, moderate concentrations of betaxolol (0.07%–0.0175%) activated caspase-8 to trigger the exogenous apoptotic pathway. Through the intrinsic apoptotic pathway, betaxolol upregulated the expression of Bcl-2 family apoptotic proteins Bax and Bad and downregulated that of anti-apoptotic proteins Bcl-2 and Bcl-xL. This subsequently disrupted the mitochondrial membrane potential and cytoplasmic transfer of cytochrome c and apoptosis-inducing factor, activated caspase-9, and induced apoptosis in HCSCs. Furthermore, continuous treatment with low betaxolol concentrations (0.00875%) for three generations of HCSCs prevented apoptosis by promoting the expression of Bcl-xL and suppressing that of Bax. However, its toxic effects initiated cellular senescence by increasing reactive oxygen species, leading to the disruption of energy metabolism and DNA damage. Finally, clinical concentrations of betaxolol had a pro-apoptotic effect on rabbit corneal stromal cells in vivo. These results suggest that betaxolol induces cytotoxicity in a concentration-dependent manner in HCSCs, and that caspase-8 and Bcl-2 family proteins may be critical switches in the conversion of different HCSC death mechanisms.

PTEN hinders the formation of scars by regulating the levels of proteins in the extracellular matrix and promoting the apoptosis of dermal fibroblasts through Bcl-xL

Hypertrophic scar (HS) is a dermatological condition characterized by an excessive accumulation of proteins in the extracellular matrix (ECM) and an elevated cell count. The development of HS is thought to be linked to the disruption of dermal fibroblast proliferation and apoptosis. The processes of cell proliferation and apoptosis are notably influenced by PTEN. However, the precise mechanisms by which PTEN regulates hypertrophic scar fibroblasts (HSFs) and its overall role in scar formation are still not fully understood. The objective of this study was to investigate the influence of PTEN on hypertrophic scars(HS) and its function in the regulation of scar formation, with the aim of identifying a pivotal molecular target for scar treatment. Our results demonstrate that the overexpression of PTEN (AdPTEN) significantly suppressed the expression of type I collagen (Col I), type III collagen (Col III), and alpha smooth muscle actin (α-SMA) in HSFs. Furthermore, it was observed that the introduction of AdPTEN resulted in the suppression of Bcl-xL expression, which consequently led to an increase in the apoptosis of HSFs. Similarly, in the inhibition of collagens expression and subsequent increase in HSF apoptosis were also observed upon silencing Bcl-xL (sibcl-xL). Additionally, the in vitro model demonstrated that both AdPTEN and sibcl-xL were effective in reducing the contraction of FPCL. The findings of our study provide validation for the role of PTEN in inhibiting the development of hypertrophic scars (HS) by modulating the expression of extracellular matrix (ECM) proteins and promoting apoptosis in hypertrophic scar fibroblasts (HSFs) via Bcl-xL. These results indicate that PTEN and Bcl-xL may hold promise as potential molecular targets for therapeutic interventions aimed at managing hypertrophic scars.

Acetylmelodorinol isolated from Sphaerocoryne affinis seeds inhibits cell proliferation and activates apoptosis on HeLa cells

BackgroundCervical cancer is a major global health concern with a high prevalence in low- and middle-income countries. Natural products, particularly plant-derived compounds, have shown immense potential for developing anticancer drugs. In this study, we aimed to investigate the anticancer properties of the pericarp and seeds of Sphaerocoryne affinis fruit on human cervical carcinoma cells (HeLa) and isolate the bioactive compound from the active fraction.MethodsWe prepared solvent fractions from the ethanol extracts of the pericarp and the seed portion by partitioning and assessing their cytotoxicity on HeLa cells. Subsequently, we collected acetylmelodorinol (AM), an anticancer compound, from the ethyl acetate fraction of seeds and determined its structure using nuclear magnetic resonance. We employed cytotoxicity assay, western blotting, Annexin V apoptosis assay, measurement of intracellular reactive oxygen species (ROS) levels, 4′,6-diamidino-2-phenylindole (DAPI) staining, and a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, to evaluate the anticancer properties of AM on HeLa.ResultsThe solvent fractions from the seed displayed considerably higher cytotoxic activity against HeLa cells than those of the pericarp. We isolated and identified acetylmelodorinol as an anticancer compound from the ethyl acetate fraction from S. affinis seed extract. Treatment with acetylmelodorinol inhibited HeLa cell proliferation with an IC50 value of 2.62 ± 0.57 µg/mL. Furthermore, this study demonstrated that acetylmelodorinol treatment disrupted cell cycle progression by reducing the expression of cyclin E, CDK1/2, and AKT/mTOR pathways, increasing the intracellular ROS levels, reducing BCL-2/BCL-XL expression, causing DNA fragmentation and nuclear shrinkage, and triggering apoptosis through caspase 3 and 9 activation in a dose-and time-dependent manner.ConclusionIn contrast to previous reports, this study focuses on the inhibitory effects of AM on the AKT/mTOR pathway, leading to a reduction in cell proliferation in cervical cancer cells. Our findings highlight the promising potential of acetylmelodorinol as an effective treatment for cervical cancer. Additionally, this study establishes a foundation for investigating the molecular mechanisms underlying AM’s properties, fostering further exploration into plant-based cancer therapies.

Silica nanoparticles induce male reproductive toxicity via Crem hypermethylation mediated spermatocyte apoptosis and sperm flagella damage.

Exposure to silica nanoparticles (SiNPs) could causally contribute to malfunctioning of the spermatogenesis, but the underlying mechanism is rarely known. This study was designed to explore the mechanism of Crem hypermethylation in SiNP-induced reproductive toxicity. The male mice were exposure to SiNPs (0 and 20mg/kg·bw) once every 5days via intratracheal instillation for 35days. After exposure stopped, half of each group was killed, and the rest were sacrificed after another 15-day feeding. GC-2 cells were treated with 0 and 20μg/mL SiNPs. The results showed that SiNPs led to structure damage of spermatocyte and sperm, caused spermatocyte apoptosis, and decreased sperm quantity and quality. After 15days of the withdrawal, the testicular tissue damage gradually recovered. Mechanistic study showed that SiNPs induced hypermethylation of the gene of cAMP responsive element modulator (Crem) in the promoter region. Downregulation of Crem inhibited the expression of outer dense fiber 1 (Odf1), resulting in abnormal sperm flagella structure; at the same time, Crem inhibited the expression of Bcl-xl, causing upregulation of cytochrome-C, cleaved-caspase-9/caspase-9, cleaved-caspase-3/caspase-3, resulting in mitochondrial dependent apoptotic pathway. However, 5-aza, DNA methylation inhibitor, could reverse the SiNP-induced downregulation of Crem and reverse the Crem/Bcl-xl-mediated mitochondrial dependent apoptotic pathway. These results suggested SiNPs could disrupt spermatogenesis by causing Crem hypermethylation to regulate the Odf1 and Bcl-xl in spermatocytes resulting in the sperm flagella structure and spermatocyte apoptosis. Our study provided new insights into the male reproductive toxicity mechanism of SiNPs; Crem demethylation may be a potential way to prevent reproductive dysfunction from SiNP exposure.

Celecoxib alleviates the DSS-induced ulcerative colitis in mice by enhancing intestinal barrier function, inhibiting ferroptosis and suppressing apoptosis

Introduction Ulcerative colitis (UC) is an inflammatory intestine disease characterized by dysfunction of the intestinal mucosal barrier, ferroptosis, and apoptosis. Previous researches suggest that celecoxib, a nonsteroidal anti-inflammatory drug, holds promise in alleviating inflammation in UC. Therefore, this study aims to investigate the effects and mechanisms of celecoxib in UC. Methods To identify ferroptosis-related drugs and genes associated with UC, we utilized the Gene Expression Omnibus (GEO), FerrDb databases, and DGIdb database. Subsequently, we established a 2.5% DSS (Dextran sulfate sodium)-induced colitis model in mice and treated them with 10 mg/kg of celecoxib to validate the bioinformatics results. We evaluated histological pathologies, inflammatory response, intestinal barrier function, ferroptosis markers, and apoptosis regulators. Results Celecoxib treatment significantly ameliorated DSS-induced UC in mice, as evidenced by the body weight change curve, colon length change curve, disease activity index (DAI) score, and histological index score. Celecoxib treatment reduced the level of pro-inflammatory factors and promoted the expressions of intestinal tight junction proteins such as Claudin-1 and Occludin, thereby restoring the integrity of the intestinal mucosal barrier. Furthermore, celecoxib treatment reversed the ferroptosis characteristics in DSS-induced mice by increasing glutathione (GSH), decreasing malondialdehyde (MDA), and increasing the expression of GPX-4 and xCT. Additionally, apoptosis was induced in mice with UC, as evidenced by increased Caspase3, BAD, P53, BAX, Caspase9 and Aifm1 production, and decreased expression of BCL-XL and BCL2. Celecoxib treatment significantly reversed the apoptotic changes in DSS-induced mice. Conclusion Our findings suggest that celecoxib effectively treats DSS-induced UC in mice by inhibiting ferroptosis and apoptosis.

Semilicoisoflavone B induces oral cancer cell apoptosis by targeting claspin and ATR-Chk1 signaling pathways.

The prevalence of oral squamous cell carcinoma (OSCC) is increasing worldwide mainly due to poor oral hygiene and unrestricted lifestyle. Advanced-stage OSCC is associated with poor prognosis and a 5-year survival rate of only 30%-50%. The present study was designed to investigate the anticancer effect and mode of action of Glycyrrhiza-derived semilicoisoflavone B (SFB) in 5-fluorourasil (5FU)-resistant human OSCC cell lines. The study findings revealed that SFB significantly reduces OSCC cell viability and colony formation ability by arresting cell cycle at the G2/M and S phases and reducing the expressions of key cell cycle regulators including cyclin A, cyclin B, CDC2, and CDK2. The compound caused a significant induction in the percentage of nuclear condensation and apoptotic cells in OSCC. Regarding pro-apoptotic mode of action, SFB was found to increase Fas-associated death domain and death receptor 5 expressions and reduce decoy receptor 2 expression, indicating involvement of extrinsic pathway. Moreover, SFB was found to increase pro-apoptotic Bim expression and reduce anti-apoptotic Bcl-2 and Bcl-xL expressions, indicating involvement of intrinsic pathway. Moreover, SFB-mediated induction in cleaved caspases 3, 8, and 9 and cleaved poly(ADP-ribose) polymerase confirmed the induction of caspase-mediated apoptotic pathways. Regarding upstream signaling pathway, SFB was found to reduce extracellular signal regulated kinase 1/2 (ERK) phosphorylation to execute its pro-apoptotic activity. The Human Apoptotic Array findings revealed that SFB suppresses claspin expression, which in turn caused reduced phosphorylation of ATR, checkpoint kinase 1 (Chk1), Wee1, and CDC25C, indicating disruption of ATR-Chk1 signaling pathway by SFB. Taken together, these findings indicate that SFB acts as a potent anticancer compound against 5FU-resistant OSCC by modulating mitogen-activated protein kinase (MAPK) and ATR-Chk1 signaling pathways.

SIVA-1 interaction with PCBP1 serves as a predictive biomarker for cisplatin sensitivity in gastric cancer and its inhibitory effect on tumor growth in vivo.

Background: SIVA-1 has been reported to play a key role in cell apoptosis and gastric cancer (GC) chemoresistance in vitro. Nevertheless, the clinical significance of SIVA-1 in GC chemotherapy remains unclear. Methods and results: Immunohistochemistry and histoculture drug response assays were used to determine SIVA-1 expression and the inhibition rate (IR) of agents to GC and to further analyze the relationship between these two phenomena. Additionally, cisplatin (DDP)-resistant GC cells were used to elucidate the role and mechanism of SIVA-1 in vivo. The results demonstrated that SIVA-1 expression was positively correlated with the IR of DDP to GC but not with those of 5-fluorouracil (5-FU) or adriamycin (ADM). Furthermore, SIVA-1 overexpression with DDP treatment synergistically inhibited tumor growth in vivo by increasing PCBP1 and decreasing Bcl-2 and Bcl-xL expression. Conclusions: Our study demonstrated that SIVA-1 may serve as an indicator of the GC sensitivity to DDP, and the mechanism of SIVA-1 in GC resistance to DDP was preliminarily revealed.

Blueberry extract attenuates DSS-induced inflammatory bowel disease in mice through inhibiting ER stress-mediated colonic apoptosis in mice.

Inflammatory bowel disease (IBD) is a chronic, debilitating condition with limited therapeutic options. Dietary components like blueberries have emerged as potential modulators of inflammation and tissue repair in gastrointestinal diseases. This study investigated endoplasmic reticulum (ER) stress-mediated apoptosis mediated protective effects of blueberries in ameliorating dextran sulfate sodium (DSS)-induced IBD. Firstly, a total of 86 anthocyanin compounds were identified in blueberry extract by LC-MS spectroscopy, including 35 cyanidin, 9 delphinidin, 14 malvidin, 10 peonidin, and 9 petunidin. Then, the animal study showed that blueberry supplementation notably ameliorated DSS-induced IBD symptoms, as evidenced by improved histopathological scores and a reduced disease activity index (DAI) score. Additionally, blueberries attenuated ER stress by inhibiting the colonic PERK/eIF2α/ATF4/CHOP signaling pathway. Furthermore, blueberries inhibited the expression of the pro-apoptotic protein, caspase-3, and decreased colonic apoptosis, as evidenced by TUNEL assay results. However, it did not affect the expression of anti-apoptotic proteins, bcl-2 and bcl-xl. Finally, blueberries enhanced the intestinal barrier by upregulating ZO-1, claudin-1, occludin, and E-cadherin. In conclusion, blueberries demonstrate therapeutic potential against DSS-induced IBD-like symptoms in mice, possibly by regulating ER stress-mediated apoptosis pathways. These findings suggest that blueberries might be an effective dietary intervention for IBD management.