Promote Cell Death Research Articles

LPCAT1 promotes melanoma cell proliferation via Akt signaling.

Melanoma is the most lethal type of skin cancer with an increasing cutaneous cancer‑related mortality rate worldwide. Despite therapeutic advances in targeted therapy and immunotherapy, the overall survival of patients with melanoma remains unsatisfactory. Thus, a further understanding of the pathogenesis of melanoma may aid towards the development of therapeutic strategies. Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is a key enzyme that converts lysophosphatidylcholine into phosphatidylcholine in lipid remodeling. In the present study, LPCAT1 was found to play a pro‑proliferative role in melanoma. Firstly, the expression of LPCAT1 was found to be upregulated in tissues from patients with melanoma compared with that in benign nevi. Subsequently, LPCAT1 knockdown was performed, utilizing short hairpin RNA, which induced melanoma cell cycle arrest at the G1/S transition and promoted cell death. Moreover, LPCAT1 facilitated melanoma cell growth in an Akt‑dependent manner. In summary, the results of the present study indicate that targeting LPCAT1 may impede cell proliferation by inhibiting Akt signaling, thus providing a promising therapeutic strategy for melanoma in clinical practice.

Targeting metabolic adaptive responses induced by glucose starvation inhibits cell proliferation and enhances cell death in osimertinib-resistant non-small cell lung cancer (NSCLC) cell lines

Osimertinib, a tyrosine kinase inhibitor targeting mutant EGFR, has received approval for initial treatment in patients with Non-Small Cell Lung Cancer (NSCLC). While effective in both first- and second-line treatments, patients eventually develop acquired resistance. Metabolic reprogramming represents a strategy through which cancer cells may resist and adapt to the selective pressure exerted by the drug. In the current study, we investigated the metabolic adaptations associated with osimertinib-resistance in NSCLC cells under low glucose culture conditions. We demonstrated that, unlike osimertinib-sensitive cells, osimertinib-resistant cells were able to survive under low glucose conditions by increasing the rate of glucose and glutamine uptake and by shifting towards mitochondrial metabolism. Inhibiting glucose/pyruvate contribution to mitochondrial respiration, glutamine deamination to glutamate, and oxidative phosphorylation decreased the proliferation and survival abilities of osimertinib-resistant cells to glucose starvation. Our findings underscore the remarkable adaptability of osimertinib-resistant NSCLC cells in a low glucose environment and highlight the pivotal role of mitochondrial metabolism in mediating this adaptation. Targeting the metabolic adaptive responses triggered by glucose shortage emerges as a promising strategy, effectively inhibiting cell proliferation and promoting cell death in osimertinib-resistant cells.

Abstract 393: RAS and PI3K activation promote glioblastoma progression and ischemia-associated tumor cell death

Abstract Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor in adults. Despite the association of tumor necrosis and a poor prognosis in GBM, the mechanisms underlying tumor necrosis formation remain unclear, likely due to the lack of appropriate experimental models to examine the development of tumor necrosis. In our study, we developed mouse models with tumor necrosis by intracranially injecting human GBM cells expressing KRAS or PI3K active mutants into immunodeficient mice. Surprisingly, despite all tumors displayed similar sizes, the control tumors expressing an empty vector (EV) did not exhibit tumor necrosis. This intriguing observation led us to explore the potential role of KRAS and PI3K in promoting cell death within the tumor microenvironment. Ischemia, which is characterized by insufficient nutrients and hypoxia, is often found in GBM. Under an in vitro ischemia mimetic condition, we found that the KRAS or PI3K activated GBM cells showed more cell death compared to EV cells. Mechanistically, ischemia activates the p38 MAPK-MK2 pathway to induce cell death, a process further enhanced by KRAS or PI3K. Notably, we observed elevated expression of p-MK2 in the peri-necrotic areas of GBMs harboring KRAS or PI3K mutants compared to the cellular tumor zones. Moreover, we revealed that ischemia induces the unfolded protein response (UPR) pathway. Among UPR-related molecules, KRAS and PI3K upregulate ERN1, which encodes the transmembrane protein kinase IRE1, in ischemic conditions. Inhibition of ERN1 not only prevented ischemia-induced cell death but also inhibited the p38 MAPK-MK2 pathway. Furthermore, we observed an increase in the expression of pro-inflammatory cytokine IL-8 under ischemic conditions, a response that was prevented by inhibitors of p38 MAPK or MK2. Lastly, we found that ischemia induces ATP release and calreticulin exposure, indicating the cell death possessing certain immunogenic cell death features. In summary, our findings revealed a pivotal role of KRAS and PI3K in inducing cell death in the ischemic GBM tumor microenvironment through activating the IRE1-p38 MAPK-MK2 pathway. The cell death under this circumstance displays pro-inflammatory and immunogenic properties. Therefore, the IRE1-p38 MAPK-MK2 pathway may be exploited for the treatment of GBM in which RAS or PI3K is activated. Citation Format: Soo Yeon Kim, Miaolu Tang, Stephen Chih, Jessica Thorpe, Tong Lu, Hong-Gang Wang, Wei Li. RAS and PI3K activation promote glioblastoma progression and ischemia-associated tumor cell death [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 393.

Abstract 2873: Radiation therapy promotes polyunsaturated fatty acid mediated ferroptosis in cervical cancer: Role of AMPK/xCT/GPX4 axis

Abstract Purpose: Previously, we found that mono-and di-unsaturated fatty acids can sensitize cervical cancer to radiotherapy (RT) through a p53 dependent apoptotic mechanism that is distinct from ferroptosis (Muhammad et al., Cancer Res. 2022; 82: 4515-27). Polyunsaturated fatty acids (PUFAs) enhance therapeutic response in preclinical tumor models by increasing lipid peroxidation (L-ROS) and induction of ferroptosis. Ferroptosis is a form of cell death that requires abundant cytosolic labile iron to promote membrane lipid peroxidation. The objective of the present study is to test whether the combination of RT + PUFAs promotes cell death via increased membrane lipid peroxidation and ferroptosis in cervical cancer, and to determine the impact of RT + PUFAs on cervix tumor cell metabolism and mitochondrial function. Experimental Procedures: Cell viability and clonogenic cell survival assays were performed using 8 human cervical cancer cell lines including normal cervix epithelial controls incubated with PUFAs (EPA, DHA and AA), before and after RT. Western blotting, siRNA-mediated knockdown, pharmacologic inhibition and activation were performed to determine whether ferroptosis dependent signals were mediating PUFA-induced RT sensitivity. Oxidative stress parameters were quantified using mass spectrometry and fluorometric dyes. Flow cytometry was used to quantify total cell ROS, lipid ROS, mitochondrial ROS and labile iron pool. Mitochondrial morphology and function were characterized using microscopy and the Seahorse assay. Summary: PUFAs + RT increased total ROS and LROS accumulation followed by a ferroptotic tumor cell death, which was iron-dependent and could be prevented by the addition of iron chelator and lipophilic antioxidants, Ferrostatin-1 and Liproxstatin-1. GPX4, a thiol dependent enzyme that eliminates lipid peroxides, and the cystine-glutamate antiporter (xCT) a key source of cystine for reduced glutathione (GSH) synthesis, were downregulated in response to PUFAs + RT. PUFAs + RT induced increased mitochondrial ROS and subsequent metabolic dysfunction. Mechanistically, the expression of AMPK, a key regulator of metabolic/energy homeostasis and mitochondrial biogenesis, was upregulated by PUFAs + RT. Pharmacological activation and inhibition of AMPK further enhanced and abrogated the effect of PUFA + RT, respectively. Conclusions: PUFAs modify the RT sensitivity of cervical cancer cells by inducing cell death through ferroptosis and mitochondrial dysfunction via AMPK activation. In vivo experiments are ongoing in immunocompromised and immunodeficient mouse tumor models to confirm this finding and determine the impact of PUFAs on RT induced tumor cell death and anti-tumor immunity. Citation Format: Naoshad Muhammad, Nishanth Gabriel, Louise M. Bengtsson, Tyler McKinnish, Naomi Msengi, Kevin Cho, Gary Patti, Julie K. Schwarz. Radiation therapy promotes polyunsaturated fatty acid mediated ferroptosis in cervical cancer: Role of AMPK/xCT/GPX4 axis [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 2873.

Abstract 3369: Dual inhibition of ATR and PI3K pathways promotes cell death in platinum-resistant endometrial cancer cells by increasing DNA damage

Abstract Background: Endometrial cancer (EC) is the most common gynecologic malignancy with increasing incidence and mortality in the U.S. Among the four subtypes characterized by the Cancer Genome Atlas, the serous-like copy number high (CNH) subtype which occurs in 15-25% of EC is associated with poor prognosis and platinum resistance, requiring alternative treatment options. ~85% CNH EC cases have impaired G1/S checkpoint regulation, making cells rely on ATR-mediated G2/M cell cycle checkpoints for optimal DNA replication and repair. Additionally, over 80% of ECs exhibit PI3K pathway activation (e.g., PIK3CA mutations), linked to enhanced DNA repair and drug resistance. Therefore, we hypothesized that dual ATR and PI3Kα inhibition would enhance DNA damage, increasing cell death in EC. Methods: CNH EC cell lines included platinum-resistant (KLE, MFE280, HEC1A, ARK2) as well as platinum-sensitive (ARK1) lines used to evaluate the activity of ATR inhibitor (ATRi) camonsertib and PI3Kα inhibitor (PI3Kαi) inavolisib. Cell growth was assessed by 3-day XTT and 9-12-day colony-forming assays. The degree of combination synergy, additivity, or antagonism was calculated using SynergyFinder with a reference highest single agent (HSA) model. An HSA synergy score > 10 indicates synergy, -10 to 10 suggests additivity and < -10 represents antagonism. DNA damage endpoints were measured by alkaline comet assay and immunoblotting for γ-H2AX. Data were repeated in triplicate, analyzed using one-way ANOVA test, and shown as mean ± SD. P < 0.05 was statistically significant. Results: All tested EC cell lines showed sensitivity to clinically attainable doses of ATRi monotherapy (IC50 0.09 - 0.98 μM), but varying sensitivity to PI3Kαi monotherapy (IC50 0.03 - 67.01 μM) unrelated to their PIK3CA mutation status. Combination treatment using clinically attainable concentrations (camonsertib < 6 μM; inavolisib < 10 μM) yielded additivity in all cell lines independent of platinum sensitivity (HSA synergy scores -0.8-10.0). Notably, increased cytotoxic effects were observed in both PIK3CA wild-type (KLE) and PIK3CA-mutant (MFE280 and HEC1A) platinum-resistant lines by colony-forming assays (4.8- to 15.4-fold decrease in colony-forming ability relative to ATRi; 1.5- to 3.5-fold decrease relative to PI3Kαi). ATRi and PI3Kαi combination induced greater DNA damage, evidenced by elevated mean comet tail moment relative to ATRi (increased 2.5- to 6.7-fold; P < 0.01) or PI3Kαi (increased 2.1- to 5.6-fold; P < 0.01) regardless of PIK3CA mutation status. Increased γ-H2AX levels were found in HEC1A cells with combination treatment (3.2-fold increase relative to ATRi; 16-fold increase relative to PI3Kαi). Conclusion: Our results suggest that dual inhibition of ATR and PI3K pathways induces greater cell death by increasing DNA damage in platinum-resistant EC cells independent of PIK3CA mutation status. Citation Format: Kristen R. Ibanez, Tzu-Ting Huang, Sotirios Sotiriou, Yvonne G. Lin, Jung-Min Lee. Dual inhibition of ATR and PI3K pathways promotes cell death in platinum-resistant endometrial cancer cells by increasing DNA damage [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 3369.

Mechanism of regulation of KIF23 on endometrial cancer cell growth and apoptosis

ObjectiveThe global incidence of endometrial cancer, a malignant tumor in females, is on the rise. It is one of the most common gynecological cancers. Early-stage endometrial cancers can often be treated successfully with uterine extirpation. However, those diagnosed at a later stage have a poor prognosis and encounter treatment challenges. Therefore, additional research is necessary to develop primary prevention strategies for high-risk women and improve survival rates among patients with endometrial cancer. Hence, gene therapy targeting KIF23 shows promise as an advanced strategy for the treatment of endometrial cancer.MethodsImmunohistochemistry, Western blotting, and PCR were used to examine the expression of KIF23 and its associated pathway factors in endometrial cancer tissue (specifically Ishikawa and SNGM cells, respectively). We investigated the functional roles of KIF23 using CCK-8, colony-forming proliferation assays, Transwell migration assays, and xenotransplantation in mice.ResultsImmunohistochemistry analysis showed variations in the expression levels of KIF23 between endometrial cancer tissue and normal endometrium tissue. KIF23 downregulated BAX and caspase-3 protein expression while upregulating BCL-2 protein expression. Additionally, knocking out KIF23 inhibits endometrial cancer cell proliferation and migration while promoting cell death. Mechanistically, our study provides evidence that KIF23 promotes endometrial cancer cell proliferation by activating the ERK and AKT/PI3K pathways, while simultaneously inhibiting programmed cell death in endometrial cancer.ConclusionOur study provides evidence to support the inhibition of endometrial cancer by KIF23 knockdown. This offers valuable insights for future research on potential therapeutic strategies for this type of cancer.Graphical

Combination MEG3 lncRNA and Ciprofloxacin dramatically decreases cell migration and viability as well as induces apoptosis in GC cells in vitro.

Gastric cancer (GC) is a prominent cause of cancer-related mortality worldwide. Long noncoding RNA (lncRNA) maternal expression gene3 (MEG3) participates in numerous signaling pathways by targeting the miRNA-mRNA axis. Studies on human tumors have demonstrated that the antibiotic Ciprofloxacin induces cell cycle changes, programmed cell death, and growth suppression. In this study, we transfected MEG3 lncRNA and Ciprofloxacin into the MKN-45 GC cell line. qRT-PCR was employed to evaluate the effects on the specific microRNA and mRNA. The wound healing test, MTT assay, and flow cytometry were used to assess the impact of their administration on cell migration, viability, and apoptosis, respectively. Research showed that miR-147 expression fell even more after MEG3 lncRNA transfection, leading to an increase in B-cell lymphoma 2 (BCL-2) levels. Ciprofloxacin transfection did not significantly affect the axis, except for MEG3, which led to its slight upregulation. MEG3 lncRNA inhibited the migration of MKN-45 cells compared to the control group. When MEG3 lncRNA was coupled with Ciprofloxacin, there was a significant reduction in cell migration compared to untreated groups and controls. MTT assay and flow cytometry demonstrated that MEG3 lncRNA decreased cell viability and triggered apoptosis. Simultaneous administration of MEG3 lncRNA and Ciprofloxacin revealed a significant reduction in cell viability caused by increased apoptosis obtained from MTT or flow cytometry assays. Modulating the miR-147-BCL-2 axis decreases cell migration and survival while promoting cell death. In conclusion, combining MEG3 lncRNA with Ciprofloxacin may be an effective therapeutic approach for GC treatment by influencing the miR-14-BCl-2 axis, resulting in reduced cell viability, migration, and increased apoptosis.

Effect on Endoplasmic Reticulum Stress of the Combined Oral Contraceptives in the Liver

Objective: We aimed to evaluate the effects of combined oral contraceptive active ingredients ethinylestradiol, drospirenone, and ethinylestradiol+drospirenone for histopathological changes, and endoplasmic reticulum stress levels in the liver.
 
 Methods: In the study, 37 to 8-week-old Balb/c female mice were used. Mice were randomly divided into the control, sham, ethinylestradiol, drospirenone, and ethinylestradiol+drospirenone groups. Experimental groups were administered ethinylestradiol, drospirenone, and ethinylestradiol+drospirenone with gavage for 35 days. In liver tissue sections, histopathological changes were detected with hematoxylin&eosin, orcein, Mallory's Azan, and periodic acid-Schiff, and the presence of endoplasmic reticulum stress was detected by Chop and Grp78 immunostaining.
 
 Results: The ethinylestradiol+drospirenone group showed significant histopathological changes compared to the control group. Some degenerative changes were noted such as swelling and size differences in hepatocytes in the ethinylestradiol+drospirenone group. When compared to the control group, an increased collagen and elastic fibers density around the vena centralis was observed in the ethinylestradiol+drospirenone group. The expression level of Grp78 protein in female mice given ethinylestradiol+drospirenone was statistically significantly increased compared to the control group. The expression level of Chop protein was significantly increased in the ethinylestradiol, drospirenone, and ethinylestradiol+drospirenone groups. 
 
 Conclusion: We concluded that the use of combined oral contraceptives increases endoplasmic reticulum stress in mouse liver tissue, and as a result, it may cause liver histopathological disorders by promoting cell death.

Application of Nanoparticles for Magnetic Hyperthermia for Cancer Treatment-The Current State of Knowledge.

Hyperthermia (HT) is an anti-cancer therapy commonly used with radio and chemotherapies based on applying heat (39-45 °C) to inhibit tumor growth. However, controlling heat towards tumors and not normal tissues is challenging. Therefore, nanoparticles (NPs) are used in HT to apply heat only to tumor tissues to induce DNA damage and the expression of heat shock proteins, which eventually result in apoptosis. The aim of this review article is to summarize recent advancements in HT with the use of magnetic NPs to locally increase temperature and promote cell death. In addition, the recent development of nanocarriers as NP-based drug delivery systems is discussed. Finally, the efficacy of HT combined with chemotherapy, radiotherapy, gene therapy, photothermal therapy, and immunotherapy is explored.

Bisphenol A promotes cell death in healthy respiratory system cells through inhibition of cell proliferation and induction of G2/M cell cycle arrest.

Bisphenol A (BPA) is a substance that can harm the environment and human health by interfering with the normal functioning of the body's hormonal system. It is commonly found in various plastic-based products such as cosmetics, canned foods, beverage containers, and medical equipment and as well as it can also be absorbed by inhalation. There have been limited studies on the effects of BPA on lung fibroblasts, and it is still unclear how high levels of BPA can impact respiratory system cells, particularly the lungs and trachea. In this research, we aimed to investigate the cell cycle disruption potential of BPA on respiratory system cells by examining healthy trachea and lung cells together for the first time. The findings indicated that BPA exposure can alter the healthy cells' morphology, leading to reduced cellular viability that has been assessed by MTT and SRB assays. BPA treatment was able to activate caspase3 as expected, which could cause apoptosis in treated cells. Although the highest dose of BPA did not increase the apoptotic rate of rat trachea cells, it remarkably caused them to become necrotic (52.12%). In addition to quantifying the induction of apoptosis and necrosis by BPA, cell cycle profiles were also determined using flow cytometry. Thereby, BPA treatment unexpectedly inhibited the cell cycle's progression by causing G2/M cell cycle arrest in both lung and tracheal cells, which hindered cell proliferation. The findings of the study suggested that exposure to BPA could lead to serious respiratory problems, even respiratory tract cancers via alterations in the cell cycle.

Ginsenoside Rk1 induces autophagy-dependent apoptosis in hepatocellular carcinoma by AMPK/mTOR signaling pathway

Hepatocellular carcinoma (HCC) is the third most lethal cancer in the world. Recent studies have shown that suppression of autophagy plays an important role in the development of HCC. Ginsenoside Rk1 is a protopanaxadiol saponin isolated from ginseng and has a significant anti-tumor effect, but its role and mechanism in HCC are still unclear. In this study, a mouse liver cancer model induced by diethylnitrosamine and carbon tetrachloride (DEN + CCl4) was employed to investigate the inhibitory effect of Rk1 on HCC. The results demonstrate that ginsenoside Rk1 effectively inhibits liver injury, liver fibrosis, and cirrhosis during HCC progression. Transcriptome data analysis of mouse liver tissue reveals that ginsenoside Rk1 significantly regulates the AMPK/mTOR signaling pathway, autophagy pathway, and apoptosis pathway. Subsequent studies show that ginsenoside Rk1 induces AMPK protein activation, upregulates the expression of autophagy marker LC3-II protein to promote autophagy, and then downregulates the expression of Bcl2 protein to trigger a caspase cascade reaction, activating AMPK/mTOR-induced toxic autophagy to promote cells death. Importantly, co-treatment of ginsenoside Rk1 with autophagy inhibitors can inhibit apoptosis of HCC cells, once again demonstrating the ability of ginsenoside Rk1 to promote autophagy-dependent apoptosis. In conclusion, our study demonstrates that ginsenoside Rk1 inhibits the development of primary HCC by activating toxic autophagy to promote apoptosis through the AMPK/mTOR pathway. These findings confirm that ginsenoside Rk1 is a promising new strategy for the treatment of HCC.

(275) IGFBP5 Short Hairpin RNA (shRNA) Constructs Improve Erectile Function in a Mouse Model of Cavernous Nerve Injury

Abstract Introduction Radical prostatectomy for prostate cancer not only induces cavernous nerve injury but also causes cavernous angiopathy, which is responsible for poor responsiveness to phosphodiesterase-5 inhibitors. Insulin-like growth factor-binding protein 5 (IGFBP5) promotes cell death and induces apoptosis in various cell types. Objective To investigate the effectiveness of IGFBP5 knockdown at improving erectile function in a mouse model of cavernous nerve injury. Methods Eight-week-old C57BL/6 mice were used to prepare cavernous nerve injury model. Mice were divided into 4 groups: a sham operation group and three cavernous nerve injury (CNI) groups, which were administered intracavernous injections of phosphate buffered saline, scrambled control shRNA, or shRNA targeting mouse IGFBP5 (shIGFBP5) lentivirus particles. One week later, we measured erectile function by electrically stimulating the bilateral cavernous nerve. Results IGFBP5 expression in cavernous tissues were significantly increased in CNI mice compare to sham mice. CNI mice had reduced erectile function, but shIGFBP5 treatment resulted in significant improvements. Furthermore, in CNI mice, numbers of cavernous endothelial cells, pericytes, and neuronal cells were increased by shIGFBP5 treatment. Conclusions Knockdown of IGFBP5 improved erectile function in CNI mice by enhancing neurovascular regeneration. Local inhibition of IGFBP5 expression may provide a new treatment strategy for the treatment of neurovascular diseases. Disclosure No.

Engineering Escherichia coli for increased Und-P availability leads to material improvements in glycan expression technology

BackgroundBacterial surface glycans are assembled by glycosyltransferases (GTs) that transfer sugar monomers to long-chained lipid carriers. Most bacteria employ the 55-carbon chain undecaprenyl phosphate (Und-P) to scaffold glycan assembly. The amount of Und-P available for glycan synthesis is thought to be limited by the rate of Und-P synthesis and by competition for Und-P between phosphoglycosyl transferases (PGTs) and GTs that prime glycan assembly (which we collectively refer to as PGT/GTs). While decreasing Und-P availability disrupts glycan synthesis and promotes cell death, less is known about the effects of increased Und-P availability.ResultsTo determine if cells can maintain higher Und-P levels, we first reduced intracellular competition for Und-P by deleting all known non-essential PGT/GTs in the Gram-negative bacterium Escherichia coli (hereafter called ΔPGT/GT cells). We then increased the rate of Und-P synthesis in ΔPGT/GT cells by overexpressing the Und-P(P) synthase uppS from a plasmid (puppS). Und-P quantitation revealed that ΔPGT/GT/puppS cells can be induced to maintain 3-fold more Und-P than wild type cells. Next, we determined how increasing Und-P availability affects glycan expression. Interestingly, increasing Und-P availability increased endogenous and recombinant glycan expression. In particular, ΔPGT/GT/puppS cells could be induced to express 7-fold more capsule from Streptococcus pneumoniae serotype 4 than traditional E. coli cells used to express recombinant glycans.ConclusionsWe demonstrate that the biotechnology standard bacterium E. coli can be engineered to maintain higher levels of Und-P. The results also strongly suggest that Und-P pathways can be engineered to increase the expression of potentially any Und-P-dependent polymer. Given that many bacterial glycans are central to the production of vaccines, diagnostics, and therapeutics, increasing Und-P availability should be a foremost consideration when designing bacterial glycan expression systems.

TRIB3 promotes malignancy of head and neck squamous cell carcinoma via inhibiting ferroptosis

Tribbles pseudokinase 3 (TRIB3) has been identified recently as a novel oncogene in several cancers. Still, further extensive research is imperative to elucidate its function and the molecular mechanisms underlying its involvement in the progression of head and neck squamous cell carcinoma (HNSCC). In our study, we found that TRIB3 silencing significantly promoted cell death by inducing ferroptosis. The interaction of TRIB3 with Transcription Factor 4 (TCF4) and β-catenin created a heterotrimeric complex, which directly interacts with the ALOXE3 promoter, detrimentally impacting its activation. The consequential partial neutralization of ferroptosis induced by TRIB3 deficiency is observed through the implementation of ALOXE3 knockdown. Furthermore, the study demonstrated that the molecular inhibitor hesperidin, targeting TRIB3, not only reduced cell malignancy but also induced ferroptosis, thereby suppressing tumor growth. Overall, our findings unequivocally validate the proposition that TRIB3 deficiency precipitates the iron death mechanism, thereby indicating that the strategic targeting of TRIB3 could emerge as an innovative therapeutic strategy for HNSCC.

Novel naphthoquinone-1H-1,2,3-triazole hybrids: Design, synthesis and evaluation as inductors of ROS-mediated apoptosis in the MCF-7 cells

The search for novel anticancer drugs is essential to expand treatment options, overcome drug resistance, reduce toxicity, promote innovation, and tackle the economic impact. The importance of these studies lies in their contribution to advancing cancer research and enhancing patient outcomes in the battle against cancer. Here, we developed new asymmetric hybrids containing two different naphthoquinones linked by a 1,2,3-1H-triazole nucleus, which are potential new drugs for cancer treatment. The antitumor activity of the novel compounds was tested using the breast cancer cell lines MCF-7 and MDA-MB-231, using the non-cancer cell line MCF10A as control. Our results showed that two out of twenty-two substances tested presented potential antitumor activity against the breast cancer cell lines. These potential drugs, named here 12g and 12h were effective in reducing cell viability and promoting cell death of the tumor cell lines, exhibiting minimal effects on the control cell line. The mechanism of action of the novel drugs was assessed revealing that both drugs increased reactive oxygen species production with consequent activation of the AMPK pathway. Therefore, we concluded that 12g and 12h are novel AMPK activators presenting selective antitumor effects.

Adavosertib-encapsulated metal-organic frameworks for p53-mutated gallbladder cancer treatment via synthetic lethality

Adavosertib (ADA) is a WEE1 inhibitor that exhibits a synthetic lethal effect on p53-mutated gallbladder cancer (GBC). However, drug resistance due to DNA damage response compensation pathways and high toxicity limits further applications. Herein, estrone-targeted ADA-encapsulated metal–organic frameworks (ADA@MOF-EPL) for GBC synthetic lethal treatment by inducing conditional factors are developed. The high expression of estrogen receptors in GBC enables ADA@MOF-EPL to quickly enter and accumulate near the cell nucleus through estrone-mediated endocytosis and release ADA to inhibit WEE1 upon entering the acidic tumor microenvironment. Ultrasound irradiation induces ADA@MOF-EPL to generate reactive oxygen species (ROS), which leads to a further increase in DNA damage, resulting in a higher sensitivity of p53-mutated cancer cells to WEE1 inhibitor and promoting cell death via conditional synthetic lethality. The conditional factor induced by ADA@MOF-EPL further enhances the antitumor efficacy while significantly reducing systemic toxicity. Moreover, ADA@MOF-EPL demonstrates similar antitumor abilities in other p53-mutated solid tumors, revealing its potential as a broad-spectrum antitumor drug.

Retracted] miR‑133b induces chemoresistance of osteosarcoma cells to cisplatin treatment by promoting cell death, migration and invasion.

[This retracts the article DOI: 10.3892/ol.2017.7432.].

Exposure to Ozone Downregulates Bcl-2 and Increases Executing Caspases-3 and -8 in the Hippocampus, Frontal Cortex, and Cerebellum of Rats.

Introduction Ozone (O3) is one of the most prevalent atmospheric pollutants, arising from a photochemical reaction between volatile organic compounds (VOC), nitrogen oxides (NOx), and sunlight.O3 triggers oxidative stress, resulting in lipid oxidation, inflammation, alterations in metabolic and cellular signaling, and potentially initiating cell death in vulnerable brain regions.Inflammation and oxidative stress are recognized for their ability to induce cell death, primarily through the apoptosis pathway, involving various proteins that participate in this process via two pathways: intrinsic and extrinsic. Objective This study aims to identify the expression of pro-apoptotic proteins and Bcl-2 in the frontal cortex, cerebellum, and hippocampus of rats exposed to O3 acutely. Methods Two groups of 20 Wistar rodents (250-300 g) were established. The control group (n=10) was exposed to unrestricted polluted air for 12 hours, while the experimental group (n=10) was exposed to 1 ppm of O3. After exposure, the animals were sacrificed for immunofluorescence and Western blot analysis. Using a t-test, the arbitrary units of pro-apoptotic proteins and Bcl-2 were compared between the two groups. Results Significant increases in caspase-8 and caspase-3 activation were found in the O3-exposedgroup compared to the control group, specifically in the frontal cortex, cerebellum, and hippocampus. Additionally, notable changes in Bcl-2 expression were observed in these brain regions. The TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay further indicated significant differences in immunopositivity between the groups in the same areas. However, intrinsic apoptotic proteins such as Bax, VDAC1, and cytochrome-c did not show significant differences between the groups within these structures. Western blotanalyses aligned with the immunofluorescence results, showing statistically significant concentrations of caspase-8 in the cerebellum, caspase-3 in the hippocampus, and Bcl-2 in the frontal cortex in the O3exposed group. Conversely, proteins like Bax, cytochrome-c, and VDAC1 did not exhibit significant differences in all analyzed structures. Conclusions This study demonstrates that acute exposure to 1 ppm of ozone can trigger neuronal apoptosis in the frontal cortex, hippocampus, and cerebellum of rats, primarily through the activation of the extrinsic apoptosis pathway via caspase-8 and caspase-3. Additionally, it causes a reduction in Bcl-2 expression, an essential antiapoptotic protein. Despite not observing the activation of intrinsic pathway proteins like BAX, VDAC, or cytochrome-c, the study suggests that chronic O3 exposure might promote cell death by activating this pathway, requiring further long-term research.

Novel plasma-polymerized coating facilitates HeLa cell spheroid formation, exerting necroptosis via β-cyclodextrin-encapsulated resveratrol

Beta-cyclodextrins (β-CDs) comprise a pore for accommodating resveratrol (Res), thereby boosting its bioavailability. Res-incorporated β -CD (Res/CD) may be cytotoxic against both normal and cancer cells. Herein, we examined whether Res/CD exhibits anticancer activity against tumor spheroids, similar to in vivo tumor mass. To prepare three-dimensional spheroids, 1,1,1,3,5,7,7,7 octamethyl-3,5-bis(trimethylsiloxyl) tetrasiloxane (OMBTSTS) was deposited to the surface of the culture dish via plasma polymerization. We observed that HeLa cells grew as spheroids on the OMBTSTS-deposited surface at 20 W plasma power. Res/CD was delivered to the hypoxic core of the spheroid, inducing necrosis, whereas Res was not. Consistently, 10 μM Res alone was not cytotoxic to two-dimensional HeLa cells grown on a culture dish and three-dimensional spheroids. However, Res/CD promoted the necroptosis of spheroids, which were split into small fragments, ultimately inducing cell spheroid death. Collectively, our data suggest that nontoxic levels of Res/CD were efficiently delivered to the hypoxic core of tumor spheroids, promoting cell death. Therefore, Res/CD can be used as an effective anticancer drug. Moreover, the plasma-polymerized OMBTSTS modification technique provides insights into the efficient formation of spheroids in various cancer cell lines.

Oxaliplatin(IV) Prodrugs Functionalized with Gemcitabine and Capecitabine Induce Blockage of Colorectal Cancer Cell Growth-An Investigation of the Activation Mechanism and Their Nanoformulation.

The use of platinum-based anticancer drugs, such as cisplatin, oxaliplatin, and carboplatin, is a common frontline option in cancer management, but they have debilitating side effects and can lead to drug resistance. Combination therapy with other chemotherapeutic agents, such as capecitabine and gemcitabine, has been explored. One approach to overcome these limitations is the modification of traditional Pt(II) drugs to obtain new molecules with an improved pharmacological profile, such as Pt(IV) prodrugs. The design, synthesis, and characterization of two novel Pt(IV) prodrugs based on oxaliplatin bearing the anticancer drugs gemcitabine or capecitabine in the axial positions have been reported. These complexes were able to dissociate into their constituents to promote cell death and induce apoptosis and cell cycle blockade in a representative colorectal cancer cell model. Specifically, the complex bearing gemcitabine resulted in being the most active on the HCT116 colorectal cancer cell line with an IC50 value of 0.49 ± 0.04. A pilot study on the encapsulation of these complexes in biocompatible PLGA-PEG nanoparticles is also included to confirm the retention of the pharmacological properties and cellular drug uptake, opening up to the possible delivery of the studied complexes through their nanoformulation.