Ivermectin and gemcitabine combination treatment induces apoptosis of pancreatic cancer cells via mitochondrial dysfunction

The FOXP1-ABCG2 axis promotes the proliferation of cancer stem cells and induces chemoresistance in pancreatic cancer

Pancreatic cancer is an aggressive disease with low survival and high recurrence rates. A major obstacle in treating pancreatic cancer is the frequent development of chemoresistance to the standard therapeutic drug, gemcitabine. One mechanism by which pancreatic cancer develops chemoresistance is through the proliferation of cancer stem cells (CSC). However, the mechanisms regulating stemness in chemoresistant tumors remain unclear. Here, we found that the expression of the transcription factor Forkhead Box P1 (FOXP1) was elevated in chemoresistant pancreatic cancer and crucial for establishing CSC characteristics. Silencing FOXP1 reduced the expressions of stemness-associated genes and diminished the formation of both spheroids and colonies, highlighting the crucial role of FOXP1 in regulating stemness in chemoresistant tumor cells. Mechanistically, we discovered that FOXP1 regulates the expression of ATP-binding cassette superfamily G member 2 (ABCG2), which induces the efflux of gemcitabine. Knockdown of FOXP1 reduced the expression of ABCG2, resulting in decreased proliferation and increased sensitivity to gemcitabine. Moreover, the inhibition of FOXP1 in orthotopic mouse models reduced tumor growth and proliferation, and enhanced sensitivity to gemcitabine. Together, our data reveal FOXP1 as a potent oncogene that promotes CSC growth in chemoresistant pancreatic cancer.

SLC5A3 depletion promotes apoptosis by inducing mitochondrial dysfunction and mitophagy in gemcitabine-resistant pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with poor prognosis, largely due to the rapid development of chemoresistance in patients. Mitochondrial dynamics play a crucial role in cancer cell survival. Currently, the specific mechanisms underlying gemcitabine resistance in PDAC remain unknown. In this study, we identified the sodium/myo-inositol co-transporter solute carrier family 5 member 3 (SLC5A3) as a key modulator promoting chemoresistance in PDAC. SLC5A3 levels were significantly upregulated in gemcitabine-resistant PDAC cells, enhancing their cell survival by stabilizing the mitochondrial functions and inhibiting apoptosis. Mitochondrial analysis showed that SLC5A3 inhibition disrupted the mitochondrial dynamics, leading to increased reactive oxygen species production, mitochondrial fission, and impaired oxidative phosphorylation. Moreover, SLC5A3 inhibition activated the PTEN-induced kinase 1/Parkin-mediated mitophagy pathway, resulting in the excessive removal of damaged and healthy mitochondria, thereby depleting the mitochondrial reserves and sensitizing the cells to apoptosis. In vivo studies revealed that targeting SLC5A3 enhanced the efficacy of gemcitabine and significantly reduced the tumor growth. Collectively, these results suggest SLC5A3-mediated mitochondrial regulation as a promising therapeutic strategy to overcome gemcitabine resistance in PDAC.

The role of mitochondrial dysfunction in the cytotoxic synergistic effect of gemcitabine and arsenic on breast cancer

Breast cancer is the most common type of cancer in women worldwide. A common approach to cancer treatment in clinical practice is to use a combination of drugs to enhance the anticancer activity of drugs while reducing their side effects. In this regard, we evaluated the effectiveness of combined treatment with gemcitabine (GCB) and arsenic (ATO) and how they affect the cell death pathway in cancer cells. Cytotoxic activity of drugs individually or combined against MDA-MB-231 and MCF-7 was performed by MTT method and isobolographic analysis was used to determine the interaction between these factors. The combination of ATO and GCB showed synergistic anti-cancer activity (CI < 1) in both cancer cell lines. The combination of ATO and GCB induced sub-G1 phase arrest, apoptosis and death rates in MCF-7 and MDA-MB-231 cells. The apoptotic response induced by the combination of GCB and ATO was dependent on caspase 3/7. Combined treatment with mitochondrial membrane potential (MMP) reduction and increased reactive oxygen species (ROS) production caused mitochondrial dysfunction. Co-treatment significantly reduced catalase (CAT) activity in both cancer cells compared to the control group and cells treated with each monotherapy. A significant decrease in cellular GSH was observed in cancer cells treated with ATO and GCB. In addition, migration and invasion were significantly reduced in breast cancer cells treated with the combination of ATO and GCB compared to cells treated with ATO and GCB. In conclusion, the combined treatment of ATO and GCB synergistically increased the anti-cancer activity, and these findings provide an effective approach for the treatment of breast cancer. To the best of our knowledge, this is the first study showing promising results for combination therapy with ATO and GCB in breast cancer.

Doramectin Induces Apoptosis in B16 Melanoma Cells

INTRODUCTION/OBJECTIVE

Metastatic melanoma resists current pharmacological regimens that act through apoptosis. This indicates that therapies acting via non-apoptotic cell-death pathways could be pursued. Doramectin has shown promising results in another cancer of neural crest origin, neuroblastoma, through the inhibition of growth via autophagy. Our research hypothesis is that doramectin induces autophagy in B16F10 melanoma cells.

METHODS

Cells were treated with doramectin (15 uM) or a combination of both doramectin and a cell-death inhibitor, compared to untreated control cells (media), and then analyzed with MTT analysis. Likewise, MDC analysis was completed to detect autophagy involvement with doramectin treatment. Flow cytometry and TUNEL Assay were conducted to observe cell death-related effects.

RESULTS

MTT analysis of doramectin-treated cells displayed a decrease in cell growth compared to control. Apoptotic morphology was prominent in melanoma cells treated with doramectin. Increased autophagy was not detected by fluorometric microscopic analysis. Flow cytometry analysis of doramectin-treated cells showed apoptosis as a major mode of cell death with some necrosis.

CONCLUSION

Doramectin induces a novel cell-death mechanism in melanoma compared to other forms of cancer and should be studied as an effective anti-cancer agent for melanoma treatment.

Selenium protects mouse spermatogonia against ivermectin-induced apoptosis by alleviating endoplasmic reticulum stress in vitro

Ivermectin (IVM) is a widely used anthelmintic in human and veterinary medicine. However, the increasing use of IVM raises concerns about its potential harm against non-targeted organisms. This study demonstrates a novel mechanism where IVM triggers apoptosis via endoplasmic reticulum (ER) stress in GC-1 spg in vitro. The inhibitory effects of selenium (Se) against the toxicological mechanism were also explored. IVM dose-dependently induces oxidative stress, dysregulated Ca2+ levels, and intracellular protein aggregation. Increased mitochondria-associated ER membrane (MAM) activity through Glucose-regulated Protein 75 (Grp75) overloads the mitochondria with Ca2+, causing mitochondrial dysfunction. These simultaneous stressors lead to unfolded protein response and apoptosis. Se reverses all these subcellular events by promoting the expression of selenoprotein-encoding genes to maintain the ER and redox homeostasis. The testis-enriched Glutathione Peroxidase 4 (Gpx4) and the testis-specific Selenoprotein V (Selenov) are only upregulated in the IVM and Se co-treatment group, suggesting their potential role in stress response. These findings confirm that toxic doses of IVM lead to programmed cell death in type B spermatogonia through redox imbalance-associated ER stress. This study provides valuable insights into refining male reproductive toxicity evaluation, targeting of ER stress to protect male germ cells, and maintaining male fertility from IVM-induced toxicity.

Reprogramming tumor immune microenvironment by milbemycin oxime results in pancreatic tumor growth suppression and enhanced anti-PD-1 efficacy

Pancreatic ductal adenocarcinoma (PDAC) has a survival rate of 12%, and multiple clinical trials testing anti-PD-1 therapies against PDAC have failed, suggesting a need for a novel therapeutic strategy. In this study, we evaluated the potential of milbemycin oxime (MBO), an antiparasitic compound, as an immunomodulatory agent in PDAC. Our results show that MBO inhibited the growth of multiple PDAC cell lines by inducing apoptosis. In vivo studies showed that the oral administration of 5 mg/kg MBO inhibited PDAC tumor growth in both subcutaneous and orthotopic models by 49% and 56%, respectively. Additionally, MBO treatment significantly increased the survival of tumor-bearing mice by 27 days as compared to the control group. Interestingly, tumors from MBO-treated mice had increased infiltration of CD8+ T cells. Notably, depletion of CD8+ T cells significantly reduced the anti-tumor efficacy of MBO in mice. Furthermore, MBO significantly augmented the efficacy of anti-PD-1 therapy, and the combination treatment resulted in a greater proportion of active cytotoxic T cells within the tumor microenvironment. MBO was safe and well tolerated in all our preclinical toxicological studies. Overall, our study provides a new direction for the use of MBO against PDAC and highlights the potential of repurposing MBO for enhancing anti-PD-1 immunotherapy.

Ivermectin Synergizes with Modulated Electro-hyperthermia and Improves Its Anticancer Effects in a Triple-Negative Breast Cancer Mouse Model

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype, with limited treatment options. Modulated electro-hyperthermia (mEHT) is a novel adjuvant cancer therapy that induces selective cancer damage. However, mEHT upregulates heat shock protein beta 1 (HSPB1), a cancer-promoting stress chaperone molecule. Thus, we investigated whether ivermectin (IVM), an anthelmintic drug, may synergize with mEHT and enhance its anticancer effects by inhibiting HSPB1 phosphorylation. Isogenic 4T1 TNBC cells were inoculated into BALB/c mice and treated with mEHT, IVM, or a combination of both. IVM synergistically improved the tumor growth inhibition achieved by mEHT. Moreover, IVM downregulated mEHT-induced HSPB1 phosphorylation. Thus, the strongest cancer tissue damage was observed in the mEHT + IVM-treated tumors, coupled with the strongest apoptosis induction and proliferation inhibition. In addition, there was no significant body weight loss in mice treated with mEHT and IVM, indicating that this combination was well-tolerated. In conclusion, mEHT combined with IVM is a new, effective, and safe option for the treatment of TNBC.

Fundamental insights and molecular interactions in pancreatic cancer: Pathways to therapeutic approaches

The gastrointestinal tract can be affected by a number of diseases that pancreatic cancer (PC) is a malignant manifestation of them. The prognosis of PC patients is unfavorable and because of their diagnosis at advanced stage, the treatment of this tumor is problematic. Owing to low survival rate, there is much interest towards understanding the molecular profile of PC in an attempt in developing more effective therapeutics. The conventional therapeutics for PC include surgery, chemotherapy and radiotherapy as well as emerging immunotherapy. However, PC is still incurable and more effort should be performed. The molecular landscape of PC is an underlying factor involved in increase in progression of tumor cells. In the presence review, the newest advances in understanding the molecular and biological events in PC are discussed. The dysregulation of molecular pathways including AMPK, MAPK, STAT3, Wnt/β-catenin and non-coding RNA transcripts has been suggested as a factor in development of tumorigenesis in PC. Moreover, cell death mechanisms such as apoptosis, autophagy, ferroptosis and necroptosis demonstrate abnormal levels. The EMT and glycolysis in PC cells enhance to ensure their metastasis and proliferation. Furthermore, such abnormal changes have been used to develop corresponding pharmacological and nanotechnological therapeutics for PC.

Gene signatures to therapeutics: Assessing the potential of ivermectin against t(4;14) multiple myeloma

BACKGROUND

Multiple myeloma (MM) is a terminal differentiated B-cell tumor disease characterized by clonal proliferation of malignant plasma cells and excessive levels of monoclonal immunoglobulins in the bone marrow. The translocation, (t)(4;14), results in high-risk MM with limited treatment alternatives. Thus, there is an urgent need for identification and validation of potential treatments for this MM subtype. Microarray data and sequencing information from public databases could offer opportunities for the discovery of new diagnostic or therapeutic targets.

AIM

To elucidate the molecular basis and search for potential effective drugs of t(4;14) MM subtype by employing a comprehensive approach.

METHODS

The transcriptional signature of t(4;14) MM was sourced from the Gene Expression Omnibus. Two datasets, GSE16558 and GSE116294, which included 17 and 15 t(4;14) MM bone marrow samples, and five and four normal bone marrow samples, respectively. After the differentially expressed genes were identified, the Cytohubba tool was used to screen for hub genes. Then, the hub genes were analyzed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. Using the STRING database and Cytoscape, protein-protein interaction networks and core targets were identified. Potential small-molecule drugs were identified and validated using the Connectivity Map database and molecular docking analysis, respectively.

RESULTS

In this study, a total of 258 differentially expressed genes with enriched functions in cancer pathways, namely cytokine receptor interactions, nuclear factor (NF)-κB signaling pathway, lipid metabolism, atherosclerosis, and Hippo signaling pathway, were identified. Ten hub genes (cd45, vcam1, ccl3, cd56, app, cd48, btk, ccr2, cybb, and cxcl12) were identified. Nine drugs, including ivermectin, deforolimus, and isoliquiritigenin, were predicted by the Connectivity Map database to have potential therapeutic effects on t (4;14) MM. In molecular docking, ivermectin showed strong binding affinity to all 10 identified targets, especially cd45 and cybb. Ivermectin inhibited t(4;14) MM cell growth via the NF-κB pathway and induced MM cell apoptosis in vitro. Furthermore, ivermectin increased reactive oxygen species accumulation and altered the mitochondrial membrane potential in t(4;14) MM cells.

CONCLUSION

Collectively, the findings offer valuable molecular insights for biomarker validation and potential drug development in t(4;14) MM diagnosis and treatment, with ivermectin emerging as a potential therapeutic alternative.

Acquired and intrinsic gemcitabine resistance in pancreatic cancer therapy: Environmental factors, molecular profile and drug/nanotherapeutic approaches

A high number of cancer patients around the world rely on gemcitabine (GEM) for chemotherapy. During local metastasis of cancers, surgery is beneficial for therapy, but dissemination in distant organs leads to using chemotherapy alone or in combination with surgery to prevent cancer recurrence. Therapy failure can be observed as a result of GEM resistance, threatening life of pancreatic cancer (PC) patients. The mortality and morbidity of PC in contrast to other tumors are increasing. GEM chemotherapy is widely utilized for PC suppression, but resistance has encountered its therapeutic impacts. The purpose of current review is to bring a broad concept about role of biological mechanisms and pathways in the development of GEM resistance in PC and then, therapeutic strategies based on using drugs or nanostructures for overcoming chemoresistance. Dysregulation of the epigenetic factors especially non-coding RNA transcripts can cause development of GEM resistance in PC and miRNA transfection or using genetic tools such as siRNA for modulating expression level of these factors for changing GEM resistance are suggested. The overexpression of anti-apoptotic proteins and survival genes can contribute to GEM resistance in PC. Moreover, supportive autophagy inhibits apoptosis and stimulates GEM resistance in PC cells. Increase in metabolism, glycolysis induction and epithelial-mesenchymal transition (EMT) stimulation are considered as other factors participating in GEM resistance in PC. Drugs can suppress tumorigenesis in PC and inhibit survival factors and pathways in increasing GEM sensitivity in PC. More importantly, nanoparticles can increase pharmacokinetic profile of GEM and promote its blood circulation and accumulation in cancer site. Nanoparticles mediate delivery of GEM with genes and drugs to suppress tumorigenesis in PC and increase drug sensitivity. The basic research displays significant connection among dysregulated pathways and GEM resistance, but the lack of clinical application is a drawback that can be responded in future.

SIRT3-dependent mitochondrial redox homeostasis mitigates CHK1 inhibition combined with gemcitabine treatment induced cardiotoxicity in hiPSC-CMs and mice

Administration of CHK1-targeted anticancer therapies is associated with an increased cumulative risk of cardiac complications, which is further amplified when combined with gemcitabine. However, the underlying mechanisms remain elusive. In this study, we generated hiPSC-CMs and murine models to elucidate the mechanisms underlying CHK1 inhibition combined with gemcitabine-induced cardiotoxicity and identify potential targets for cardioprotection. Mice were intraperitoneally injected with 25 mg/kg CHK1 inhibitor AZD7762 and 20 mg/kg gemcitabine for 3 weeks. hiPSC-CMs and NMCMs were incubated with 0.5 uM AZD7762 and 0.1 uM gemcitabine for 24 h. Both pharmacological inhibition or genetic deletion of CHK1 and administration of gemcitabine induced mtROS overproduction and pyroptosis in cardiomyocytes by disrupting mitochondrial respiration, ultimately causing heart atrophy and cardiac dysfunction in mice. These toxic effects were further exacerbated with combination administration. Using mitochondria-targeting sequence-directed vectors to overexpress CHK1 in cardiomyocyte (CM) mitochondria, we identified the localization of CHK1 in CM mitochondria and its crucial role in maintaining mitochondrial redox homeostasis for the first time. Mitochondrial CHK1 function loss mediated the cardiotoxicity induced by AZD7762 and CHK1-knockout. Mechanistically, mitochondrial CHK1 directly phosphorylates SIRT3 and promotes its expression within mitochondria. On the contrary, both AZD7762 or CHK1-knockout and gemcitabine decreased mitochondrial SIRT3 abundance, thus resulting in respiration dysfunction. Further hiPSC-CMs and mice experiments demonstrated that SIRT3 overexpression maintained mitochondrial function while alleviating CM pyroptosis, and thereby improving mice cardiac function. In summary, our results suggest that targeting SIRT3 could represent a novel therapeutic approach for clinical prevention and treatment of cardiotoxicity induced by CHK1 inhibition and gemcitabine.

SLC38A5 Modulates Ferroptosis to Overcome Gemcitabine Resistance in Pancreatic Cancer

Pancreatic cancer is characterized by a poor prognosis, with its five-year survival rate lower than that of any other cancer type. Gemcitabine, a standard treatment for pancreatic cancer, often has poor outcomes for patients as a result of chemoresistance. Therefore, novel therapeutic targets must be identified to overcome gemcitabine resistance. Here, we found that SLC38A5, a glutamine transporter, is more highly overexpressed in gemcitabine-resistant patients than in gemcitabine-sensitive patients. Furthermore, the deletion of SLC38A5 decreased the proliferation and migration of gemcitabine-resistant PDAC cells. We also found that the inhibition of SLC38A5 triggered the ferroptosis signaling pathway via RNA sequencing. Also, silencing SLC38A5 induced mitochondrial dysfunction and reduced glutamine uptake and glutathione (GSH) levels, and downregulated the expressions of GSH-related genes NRF2 and GPX4. The blockade of glutamine uptake negatively modulated the mTOR-SREBP1-SCD1 signaling pathway. Therefore, suppression of SLC38A5 triggers ferroptosis via two pathways that regulate lipid ROS levels. Similarly, we observed that knockdown of SLC38A5 restored gemcitabine sensitivity by hindering tumor growth and metastasis in the orthotopic mouse model. Altogether, our results demonstrate that SLC38A5 could be a novel target to overcome gemcitabine resistance in PDAC therapy.