Apoptosis In Pancreatic Cancer Cells Research Articles

The Tanshinones (Tan) Extract From Salvia miltiorrhiza Bunge Induces ROS-Dependent Apoptosis in Pancreatic Cancer via AKT Hyperactivation-Mediated FOXO3/SOD2 Signaling.

Salvia miltiorrhiza (SM) is a commonly used herb in traditional Chinese medicine (TCM) and has been used in the treatment of pancreatic cancer to relieve the symptom of "blood stasis and toxin accumulation." Tanshinones (Tan), the main lipophilic constituents extracted from the roots and rhizomes of SM, have been reported to possess anticancer functions in several cancers. But the mechanism of how the active components work in pancreatic cancer still need to be clarified. In this study, we aimed to investigate the therapeutic potential of Tan in pancreatic cancer and elucidate the underlying mechanisms. The viabilities of PANC-1 and Bxpc-3 cells were determined by MTT assay, after treatment with various concentrations of Tan. The apoptotic cells were quantified by annexin V-FITC/PI staining and DAPI staining assays. The expression of relative proteins was used western blotting. Tumor growth was assessed by subcutaneously inoculating cells into C57BL/6 mice. Our experiments discovered that Tan effectively suppressed pancreatic cancer cell proliferation and promoted apoptosis. Mechanistically, we propose that Tan enhances intracellular ROS levels by activating the AKT/FOXO3/SOD2 signaling pathway, ultimately leading to apoptosis in pancreatic cancer cells. In vivo assay showed the antitumor effect of Tan. Tan, a natural compound from Salvia miltiorrhiza, was found to effectively suppress pancreatic cancer cell proliferation and promote apoptosis both in vitro and in vivo. Mechanistically, we propose a positive feedback loop mechanism. These findings provide valuable insights into the molecular pathways driving pancreatic cancer progression.

Corosolic acid enhances oxidative stress-induced apoptosis and senescence in pancreatic cancer cells by inhibiting the JAK2/STAT3 pathway.

Pancreatic cancer (PC) is a fatal human malignancy with a poor prognosis. Corosolic acid (CRA) is a triterpenoid, has been reported to have inhibitory effects on tumor growth. However, the role of CRA on PC has not been explored. Here, we aimed to uncover the molecular mechanisms of CRA in PC progression. Cell viability, lactate dehydrogenase (LDH) release, cell apoptosis and senescence were detected by cell counting kit-8 (CCK-8), LDH, flow cytometry and senescence associated-β-galactosidase (SA-β-gal) assay. Levels of relevant proteins and oxidative stress (OS) markers were evaluated by Western blot and enzyme-linked immunosorbent assay (ELISA). A xenograft tumor model was established to explore the in vivo effects of CRA on PC. We found that CRA inhibited PC cell viability and promoted LDH release in a dose-dependent manner, but had no significant effect on human normal pancreatic ductal epithelial cells HPDE6C7. CRA increased OS-induced cell apoptosis and senescence in HAPC and SW1990 cells. And CRA decreased the levels of anti-apoptotic protein Bcl-2, and elevated the expression of pro-apoptotic protein Bax and senescence-associated proteins P21 and P53. Besides, CRA decreased tumor growth in xenograft models. Furthermore, CRA inactivated the Janus kinase-2 (JAK2)/Signal Transducer and Activator of Transcription 3 (STAT3) signaling pathway in HAPC and SW1990 cells. Functional experiments demonstrated that activation of the JAK2/STAT3 pathway by the JAK2 activator coumermycin A1 (C-A1) or the STAT3 activator colivelin (col) reduced the contribution effect of OS, apoptosis and senescence by CRA. Taken together, our findings indicated that CRA exerted anti-cancer effects in PC by inhibiting the JAK2/STAT3 pathway.

Retracted: Apatinib Promotes Apoptosis of Pancreatic Cancer Cells through Downregulation of Hypoxia-Inducible Factor-1α and Increased Levels of Reactive Oxygen Species.

[This retracts the article DOI: 10.1155/2019/5152072.].

Natural products as inhibitors against pancreatic cancer cell proliferation and invasion: possible mechanisms.

Pancreatic cancer is one of the gastrointestinal tumors with the lowest survival rate and the worst prognosis. At the time of diagnosis, the majority of patients have missed the opportunity for radical surgical resection and opt for chemotherapy as their primary treatment choice. And drug resistance emerges during the application of the most widely used chemotherapeutic regimens such as modified FOLFIRINOX regimen, gemcitabine monotherapy or 5-Fluorouracil combination therapy, which further reduces the therapeutic efficacy. Therefore, it is urgent to explore better treatment strategies for pancreatic cancer. In recent years, more and more studies have found that natural products have significant anti-pancreatic cancer properties. In this paper, we reviewed the possible mechanisms by which natural products inhibit the proliferation and invasion of pancreatic cancer cells, including the possible mechanisms of targeting the inhibition of the growth and proliferation regulatory pathways of pancreatic cancer cells, inducing apoptosis and autophagy of pancreatic cancer cells, inhibiting the EMT process of pancreatic cancer cells, and inhibiting the angiogenesis of pancreatic cancer. Meanwhile, natural products have also hindered the progress of their basic and clinical research due to the complexity of their composition and the limitation of biological extraction technology. Further exploration of the specific molecular mechanisms of natural products to inhibit the proliferation and invasion of pancreatic cancer cells, optimization of purification and preparation techniques, and enrichment of basic and clinical trials to verify their efficacy and safety may be the future direction of natural products in the field of anti-pancreatic cancer research.

Unlocking the Therapeutic Potential: Harnessing miR-125a-5p To Enhance Autophagy and Apoptosis in Pancreatic Cancer through Targeting STAT3.

Objectives: miR-125a-5p's role in various cancers has been recognized, yet its specific function in pancreatic cancer (PCa) demands further exploration. This study aimed to reveal the potential function of miR-125a-5p in PCa. Methods: With publicly available databases, we explored the expression pattern and prognostic relevance of miR-125a-5p and STAT3 in PCa. We measured miR-125a-5p levels in PCa tissues, plasma and cell lines using RT-qPCR. To assess functional effects, PANC-1 cells were transfected with miR-125a-5p mimics and inhibitors, as well as siRNA-STAT3 and STAT3 vectors. Cell proliferation was estimated using Cell Counting Kit-8, while autophagy and apoptosis were examined by transmission electron microscopy and TUNEL assay, respectively. Western blot analysis was also performed to detect proteins associated with autophagy and apoptosis. The regulatory relationship of miR-125a-5p on STAT3 was verified using a dual luciferase reporter assay. The influence of miR-125a-5p on tumor development was evaluated in xenograft models. Results: Decreased expression of miR-125a-5p was found in PCa samples, and low expression of miR-125a-5p was associated with a poorer prognosis in PCa patients. Functional assays indicated miR-125a-5p suppressed cell growth while enhancing apoptosis and autophagy in PCa cells. STAT3 represents a specific target of miR-125a-5p, inhibiting STAT3 reversed the inhibitory effect of overexposed miR-125a-5p. Additionally, miR-125a-5p significantly restrained tumor development in mice. Conclusions: miR-125a-5p functions as a tumor suppressor in PCa by targeting STAT3, thereby inducing autophagy and apoptosis. Its regulatory role underscores its potential as a valuable biomarker for PCa diagnosis and therapy, warranting further clinical investigation.

Therapeutic potential of SHCBP1 inhibitor AZD5582 in pancreatic cancer treatment.

Pancreatic cancer (PC) is a highly aggressive and deadly malignancy with limited treatment options and poor prognosis. Identifying new therapeutic targets and developing effective strategies for PC treatment is of utmost importance. Here, we revealed that SHCBP1 is significantly overexpressed in PC and negatively correlated with patient prognosis. Knockout of SHCBP1 inhibits the proliferation and migration of PC cells invitro, and suppresses the tumor growth invivo. In addition, we identified AZD5582 as a novel inhibitor of SHCBP1, which efficiently restrains the growth of PC in cell lines, organoids, and patient-derived xenografts. Mechanistically, we found that AZD5582 induced the apoptosis of PC cells by inhibiting the activity of PI3K/AKT signaling and preventing the degradation of TP53. Collectively, our study highlights SHCBP1 as a potential therapeutic target and its inhibitor AZD5582 as a viable agent for PC treatment strategies.

Celastrol suppresses human pancreatic cancer via m6A-YTHDF3-mediated downregulation of Claspin and Bcl-2

BackgroundCelastrol has been revealed to exhibit anticancer pharmacological activity, however, the molecular mechanisms of celastrol involved in pancreatic cancer remain to be further elucidated. The present study was to illustrate whether celastrol suppresses pancreatic cancer through modulating RNA m6A modification.MethodsEffect of celastrol treatment on the malignant phenotypes of pancreatic cancer cells was evaluated by CCK-8 assay, EdU assay, colony formation assay, flow cytometry analysis and subcutaneous xenograft experiments. RNA sequencing (RNA-seq) analysis was carried out to analyze the genes differentially expressed in celastrol-treated pancreatic cancer cells. RT-qPCR, Western blotting and immunohistochemistry were employed to evaluate the expression of the indicated genes. RNA dot blot and quantification of total RNA m6A modification assays, MeRIP-qPCR assay, RIP-qPCR assay, RNA stability and protein stability assays were applied to evaluate the regulatory mechanism of celastrol treatment in pancreatic cancer cells.ResultsWe demonstrated that celastrol suppressed cell proliferation and induced cell cycle arrest and apoptosis of pancreatic cancer cells in vitro, and decreased tumor growth in vivo. Specifically, Bcl-2, Claspin, METTL3 and YTHDF3 were identified as the potential targets of celastrol treatment in pancreatic cancer cells. Moreover, our results indicated that celastrol treatment downregulated METTL3 and decreased m6A levels of Claspin and Bcl-2 mRNA, leading to the degradation of Claspin and Bcl-2 mRNA in pancreatic cancer cells. Furthermore, we revealed that celastrol treatment downregulated Claspin and Bcl-2, at least in part, in an m6A-YTHDF3-mediated manner in pancreatic cancer cells.ConclusionOur study highlighted a novel mechanism underlying celastrol-induced cellular proliferation inhibition and apoptosis in pancreatic cancer cells via m6A-YTHDF3-mediated downregulation of Claspin and Bcl-2.

Synergistic effects of resveratrol with gemcitabine in pancreatic cancer chemotherapy by inhibiting the c-Met/PARP1 axis

Objective: Pancreatic cancer is a highly malignant tumor of the digestive tract with a dismal prognosis. A key challenge of pancreatic cancer is its resistance to chemotherapy. The c-Met/PARP1 axis plays an important role in the therapeutic resistance of breast cancer and hepatocellular carcinoma. Therefore, this study aims to explore potential therapeutic targets for improving chemotherapy for pancreatic cancer and the underlying mechanisms. Methods: Gemcitabine-resistant pancreatic cancer cell lines were constructed by our laboratory using a continuous low-concentration gemcitabine induction method. The proliferation and apoptosis of combination therapy were examined using flow cytometry and comet assay. Synergistic effects of two drugs were determined by Chou-Talalay's combination index (CI). The interactions between proteins were predicted using the AutoDock model and detected through Coimmunoprecipitation assays. Results: The combination of resveratrol and gemcitabine inhibited proliferation and promoted apoptosis of pancreatic cancer cells. We found that c-Met and PARP1 were highly expressed in gemcitabine-resistant pancreatic cancer cells. However, resveratrol inhibited their expression and improved the effectiveness of gemcitabine-induced DNA damage. In addition, our data demonstrated that resveratrol and gemcitabine had synergistic effects (CI < 1). Furthermore, the protein interactions between c-Met and PARP1 were attenuated after the early stage of resveratrol intervention. Using AutoDock models, we predicted the potential binding sites where resveratrol could impact the protein interaction between c-Met (tyrosine kinase domain) and PARP1 (CAT domain). Conclusion: Our results suggested that the synergistic effects of resveratrol with gemcitabine depend on the c-Met/PAPR1 axis. Using resveratrol as a combined chemotherapy agent may have clinical benefits for patients with refractory pancreatic cancer.

Silencing of CPNE1-TRAF2 Axis Restrains the Development of Pancreatic Cancer.

Copine 1 (CPNE1) acts as a promoter in the progression of many kinds of cancers with the exception of pancreatic cancer (PC). This research is designed to probe the function of the CPNE1-tumor necrosis factor receptor-associated factor 2 (TRAF2) axis in PC. In vivo and in vitro models of PC were constructed, and a series of biological function tests, including MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide], colony formation, flow cytometry, and immunohistochemistry, were performed. The level of CPNE1 elevated dramatically in PC cells. Downregulation of CPNE1in PC cells resulted in the inhibition of colony formation and proliferation. In addition, the silencing of CPNE1 induced the G1/S arrest and apoptosis in PC cells. Additionally, TRAF2 positively interacted with CPNE1 in PANC cells. CPNE1 silencing also inhibited the growth of tumors in in vivo mouse models. Functional experiments revealed that the anti-tumor effect of CPNE1 silencing was counteracted by TRAF2 overexpression, and the tumor-promoting effect of TRAF2 overexpression was reversed by CPNE1 silencing. In summary, our findings indicate that the silencing of the CPNE1-TRAF2 axis restrains PC development.

Lovastatin Treatment Inducing Apoptosis in Human Pancreatic Cancer Cells by Inhibiting Cholesterol Rafts in Plasma Membrane and Mitochondria

Resistance to anticancer drugs is a problem in the treatment of pancreatic ductal carcinoma (PDAC) and overcoming it is an important issue. Recently, it has been reported that statins induce apoptosis in cancer cells but the mechanism has not been completely elucidated. We investigated the antitumor mechanisms of statins against PDAC and their impact on resistance to gemcitabine (GEM). Lovastatin (LOVA) increased mitochondrial oxidative stress in PDAC cells, leading to apoptosis. LOVA reduced lipid rafts in the plasma membrane and mitochondria, suppressed the activation of epithelial growth factor receptor (EGFR) and AKT in plasma membrane rafts, and reduced B-cell lymphoma 2 (BCL2)-Bcl-2-associated X protein (BAX) binding and the translocation of F1F0 ATPase in mitochondrial rafts. In the three GEM-resistant cell lines derived from MIA and PANC1, the lipid rafts in the cell membrane and the mitochondria were increased to activate EGFR and AKT and to increase BCL2-BAX binding, which suppressed apoptosis. LOVA abrogated these anti-apoptotic effects by reducing the rafts in the resistant cells. By treating the resistant cells with LOVA, GEM sensitivity improved to the level of the parental cells. Therefore, cholesterol rafts contribute to drug resistance in PDAC. Further clinical research is warranted on overcoming anticancer drug resistance by statin-mediated intracellular cholesterol regulation.

Targeting protein methylation in pancreatic cancer cells results in KRAS signaling imbalance and inhibition of autophagy

Pancreatic cancer cells with mutant KRAS require strong basal autophagy for viability and growth. Here, we observed that some processes that allow the maintenance of basal autophagy in pancreatic cancer cells are controlled by protein methylation. Thus, by maintaining the methylation status of proteins such as PP2A and MRAS, these cells can sustain their autophagic activity. Protein methylation disruption by a hypomethylating treatment (HMT), which depletes cellular S-adenosylmethionine levels while inducing S-adenosylhomocysteine accumulation, resulted in autophagy inhibition and endoplasmic reticulum stress-induced apoptosis in pancreatic cancer cells. We observed that by reducing the membrane localization of MRAS, hypomethylation conditions produced an imbalance in KRAS signaling, resulting in the partial inactivation of ERK and hyperactivation of the PI3K/AKT–mTORC1 pathway. Interestingly, HMT impeded CRAF activation by disrupting the ternary SHOC2 complex (SHOC2/MRAS/PP1), which functions as a CRAF-S259 holophosphatase. The demethylation events that resulted in PP2A inactivation also favored autophagy inhibition by preventing ULK1 activation while restoring the cytoplasmic retention of the MiT/TFE transcription factors. Since autophagy provides pancreatic cancer cells with metabolic plasticity to cope with various metabolic stress conditions, while at the same time promoting their pathogenesis and resistance to KRAS pathway inhibitors, this hypomethylating treatment could represent a therapeutic opportunity for pancreatic adenocarcinomas.

Overexpression of ZNF488 supports pancreatic cancer cell proliferation and tumorigenesis through inhibition of ferroptosis via regulating SCD1-mediated unsaturated fatty acid metabolism

BackgroundPancreatic cancer is a malignancy with high mortality. Once diagnosed, effective treatment strategies are limited and the five-year survival is extremely poor. Recent studies have shown that zinc finger proteins play important roles in tumorigenesis, including pancreatic cancer. However, it remains unknown on the clinical significance, function and underlying mechanisms of zinc finger protein 488 (ZNF488) during the development of pancreatic cancer.MethodsThe clinical relevance of ZNF488 and stearoyl-CoA desaturase 1 (SCD1) was examined by analyzing the data from The Cancer Genome Atlas (TCGA) and immunohistochemical staining of the tissue microarray. Gain-of-function and loss-of-function experiments were performed by transfecting the cells with overexpressing lentivirus and siRNAs or shRNA lentivirus, respectively. The function of ZNF488 in pancreatic cancer was assessed by CCK8, colony formation, EdU staining, PI/Annexin V staining and xenografted tumorigenesis. Chip-qPCR assay was conducted to examine the interaction between ZNF488 and the promoter sequence of SCD1. Transcription activity was measured by dual luciferase reporter assay. mRNA and protein expression was detected by qRT-PCR and immunoblotting experiment, respectively. Fatty acid was quantified by gas chromatography mass spectrometry.ResultsZNF488 was overexpressed in pancreatic cancer samples compared with normal tissues. High expression of ZNF488 predicted the poor prognosis of the patients. In vitro, ZNF488 upregulation contributed to the EuU cooperation, proliferation and colony formation of MIAPaCa-2 and PANC-1 cells. Based on PI/Annexin V and trypan blue staining results, we showed that ZNF488 suppressed the ferroptosis and apoptosis of pancreatic cancer cells. Mechanistically, ZNF488 directly interacted with the promoter sequence of SCD1 gene and promoted its transcription activity, which resulted in enhanced palmitoleic and oleic acid production, as well as the peroxidation of fatty acid. In vivo, ZNF488 overexpression promoted the xenograted tumorigenesis of PANC-1, which was reversed by SCD1 knockdown. Importantly, combination of erastin and SCD1 inhibitors A939572 completely blunted the growth of ZNF488 overexpressed MIAPaCa-2 and PANC-1 cells. Usage of A939572 or erastin recovered the sensitivity of pancreatic cancer cells to the treatment of gemcitabine. Lastly, we found a positive correlation between ZNF488 and SCD1 in pancreatic cancer patients based on TCGA and immunohistochemical staining results.ConclusionOverexpression of ZNF488 suppresses the ferroptosis and apoptosis to support the growth and tumorigenesis of pancreatic cancer through augmentation of SCD1-mediated unsaturated fatty acid metabolism. Combination of SCD1 inhibitors, ferroptosis inducers or gemcitabine could be applied for the treatment of pancreatic cancer with overexpression of ZNF488.

TROP2-directed nanobody-drug conjugate elicited potent antitumor effect in pancreatic cancer

BackgroundPancreatic cancer is a highly aggressive malignancy with limited treatment options and a poor prognosis. Trophoblast cell surface antigen 2 (TROP2), a cell surface antigen overexpressed in the tumors of more than half of pancreatic cancer patients, has been identified as a potential target for antibody–drug conjugates (ADCs). Almost all reported TROP2-targeted ADCs are of the IgG type and have been poorly studied in pancreatic cancer. Here, we aimed to develop a novel nanobody-drug conjugate (NDC) targeting TROP2 for the treatment of pancreatic cancer.ResultsIn this study, we developed a novel TROP2-targeted NDC, HuNbTROP2-HSA-MMAE, for the treatment of TROP2-positive pancreatic cancer. HuNbTROP2-HSA-MMAE is characterized by the use of nanobodies against TROP2 and human serum albumin (HSA) and has a drug-antibody ratio of 1. HuNbTROP2-HSA-MMAE exhibited specific binding to TROP2 and was internalized into tumor cells with high endocytosis efficiency within 5 h, followed by intracellular translocation to lysosomes and release of MMAE to induce cell apoptosis in TROP2-positive pancreatic cancer cells through the caspase-3/9 pathway. In a xenograft model of pancreatic cancer, doses of 0.2 mg/kg and 1 mg/kg HuNbTROP2-HSA-MMAE demonstrated significant antitumor effects, and a dose of 5 mg/kg even eradicated the tumor.ConclusionHuNbTROP2-HSA-MMAE has desirable affinity, internalization efficiency and antitumor activity. It holds significant promise as a potential therapeutic option for the treatment of TROP2-positive pancreatic cancer.Graphical

A benzochalcone derivative synchronously induces apoptosis and ferroptosis in pancreatic cancer cells

Background Pancreatic cancer is a highly aggressive and lethal disease with limited treatment options. In this study, we investigated the potential therapeutic effects of compound KL-6 on pancreatic cancer cells. Methods The study involved assessing the inhibitory effects of KL-6 on cell proliferation, clonogenic potential, cell cycle progression, apoptosis, migration, and invasion. Additionally, we examined the action mechanism of KL-6 by RNA-seq and bioinformatic analysis and validated by qRT-PCR and western blot in pancreatic cancer cells. Results Our results demonstrated that KL-6 effectively inhibited the growth of pancreatic cancer cells in a dose-dependent manner. It induced G2/M phase cell cycle arrest and apoptosis, disrupting the cell cycle progression and promoting cell death. KL-6 also exhibited inhibitory effects on cell migration and invasion, suggesting its potential to suppress the metastatic properties of pancreatic cancer cells. Furthermore, KL-6 modulated the expression of genes involved in various cancer-related pathways including apoptosis and ferroptosis. Conclusion These findings collectively support the potential of KL-6 as a promising therapeutic option for pancreatic cancer treatment. Further research is needed to fully understand the underlying mechanisms and evaluate the clinical efficacy of KL-6 in pancreatic cancer patients.

Mechanisms of ginseng in pancreatic cancer metastasis

It has been shown that ginsenosides can inhibit proliferation, migration, and invasion of pancreatic cancer (PC) cells, and promote apoptosis of PC cells. However, the potential mechanisms of ginseng in treating PC metastasis (PCM) have not been fully elucidated. In this study, we employed an integrated bioinformatics approach of network pharmacology analysis. By selecting common targets of diseases and drugs, a drug-component-target-disease network was constructed to analyze the biological functions and signaling pathways involved in the targets. A total of 6 PC samples were includedd, which were divided into primary PC group (PANC-1, n=3) and metastatic PC group. A total of 9263 differentially expressed genes (DEGs) and 14 PC target genes were identified. According to the network pharmacology analysis, we found that ginsenoside Rg3 was associated with the treatment of PCM and identified 6 potential targets. Among them, CD44, EGFR, KRAS, and PRNP were the main DEGs related to the treatment of PC by ginsenoside Rg3. These genes were mainly enriched in the Proteoglycans in Cancer pathway, and KRAS, EGFR, and CD44 were upregulated in the pathway, which may be affected by the ginsenoside Rg3. This provides a new direction for further research on the mechanisms of ginseng in PCM.

Mechanisms of ginseng in pancreatic cancer metastasis

It has been shown that ginsenosides can inhibit proliferation, migration, and invasion of pancreatic cancer (PC) cells, and promote apoptosis of PC cells. However, the potential mechanisms of ginseng in treating PC metastasis (PCM) have not been fully elucidated. In this study, we employed an integrated bioinformatics approach of network pharmacology analysis. By selecting common targets of diseases and drugs, a drug-component-target-disease network was constructed to analyze the biological functions and signaling pathways involved in the targets. A total of 6 PC samples were includedd, which were divided into primary PC group (PANC-1, n=3) and metastatic PC group. A total of 9263 differentially expressed genes (DEGs) and 14 PC target genes were identified. According to the network pharmacology analysis, we found that ginsenoside Rg3 was associated with the treatment of PCM and identified 6 potential targets. Among them, CD44, EGFR, KRAS, and PRNP were the main DEGs related to the treatment of PC by ginsenoside Rg3. These genes were mainly enriched in the Proteoglycans in Cancer pathway, and KRAS, EGFR, and CD44 were upregulated in the pathway, which may be affected by the ginsenoside Rg3. This provides a new direction for further research on the mechanisms of ginseng in PCM.

Lithium chloride induces apoptosis by activating endoplasmic reticulum stress in pancreatic cancer

Lithium compounds, a classic class of metal complex medicine that target GSK 3β and are widely known as mood-stabilizer, have recently been reported as potential anti-tumor drugs. The objective of this investigation was to explore the anticancer potential of lithium chloride (LiCl) and elucidate its mode of action in pancreatic cancer cells. The MTT, colony formation, and Edu assay were used to evaluate the impact of LiCl on pancreatic cancer cell proliferation. Various methods were employed to investigate the anti-tumor activity of LiCl and its underlying mechanisms. Cell cycle analysis and apoptosis detection assays were utilized for in vitro experiments, while the orthotopic pancreatic cancer mouse model was employed to evaluate the effectiveness of LiCl treatment in vivo. Furthermore, the impact of LiCl on the proliferation of patient-derived organoids was also studied. The results demonstrated that LiCl inhibited the proliferation of pancreatic cancer (PC) cells, induced G2/M phase arrest, and activated apoptosis. Notably, the triggering of endoplasmic reticulum (ER) stress by LiCl was observed, leading to the activation of the PERK/CHOP/GADD34 pathway, which subsequently promoted apoptosis in PC cells. In the future, Lithium compounds could become an essential adjunct in the treatment of human pancreatic cancer.

Inhibition of autophagy promotes sonodynamic therapy-induced apoptosis of pancreatic cancer cells.

Sonodynamic therapy (SDT), a promising non-invasive therapeutic modality, has attracted increasing attention in the treatment of pancreatic cancer (PC). At present, the role of autophagy in SDT of PC remains unclear. This study aims to explore the role of autophagy in SDT of PC and its effect on apoptosis of PC cells. PC cells (Capan-1 and BxPC-3) underwent incubation with 5-aminolevulinic acid (5-ALA) or/and ultrasound (US) exposure (control, 5-ALA, US, and SDT groups), followed by measurement of cell apoptosis and autophagy. Specifically, cell viability, apoptosis, and the expression of apoptosis-related proteins (cleaved Caspase-3, Bax, and Bcl-2) were measured using CCK-8 assay, flow cytometry, and western blot analysis, respectively. The mitochondrial morphology was observed with the transmission electron microscopy, accompanied by the detection of autophagosome marker (LC3) co-located with Mito and the protein expression of LC3II/I. Before SDT treatment, the autophagy inhibitor 3-MA and the apoptosis inhibitor z-VAD were respectively added to PC cell cultures to evaluate the effects of autophagy inhibition on apoptosis and apoptosis inhibition on autophagy in PC cells. Compared with the control group, cell viability was inhibited and cell apoptosis and autophagy were enhanced in the SDT group, while cell viability, autophagy, and apoptosis in the 5-ALA and US groups were not significantly changed. Moreover, 3-MA treatment inhibited autophagy and accelerated apoptosis, whereas z-VAD treatment reduced apoptosis but did not affect autophagy in PC cells. Autophagy was activated in SDT-treated PC cells, and inhibition of autophagy promoted cell apoptosis in PC cells.

Saikosaponin d modulates the polarization of tumor-associated macrophages by deactivating the PI3K/AKT/mTOR pathway in murine models of pancreatic cancer.

The tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) poses a major obstacle to traditional and immunomodulatory cancer therapies and is closely associated with macrophage polarization. Saikosaponin d (SSd), a major active component of triterpene saponins derived from Bupleurum falcatum, has anti-inflammatory and antitumor activities. However, whether SSd can regulate immune cells during the development of the TME in PDAC remains unknown. In the present study, we aimed to analyze the role of SSd in regulating immune cells in the PDAC TME, especially the polarization of macrophages, and examine the related mechanisms. An orthotopic PDAC cancer model was used to investigate the antitumor activities and the regulation of immune cells in vivo. In vitro, bone marrow mononuclear (BM-MNC) cells and RAW 264.7 cells were used to induce the M2 macrophage phenotype and examine the effects and molecular mechanism of SSd on M2 macrophage polarization. The results revealed that SSd could directly inhibit the apoptosis and invasion of pancreatic cancer cells, modulate the immunosuppressive microenvironment and reactivate the local immune response, especially by decreasing the shift toward M2 macrophage polarization by downregulating phosphorylated STAT6 levels and the PI3K/AKT/mTOR signaling pathway. Furthermore, 740-Y-P (PI3K activator) was used to verify that SSd inhibited M2 polarization in RAW264.7 cells via the PI3K/AKT/mTOR signaling pathway. In conclusion, this study provided experimental evidence of the antitumor effect of SSd, especially in the regulation of M2 macrophage polarization, and demonstrated that SSd may be a promising therapeutic agent in PDAC.

Discovery of a pyrrole-pyridinimidazole derivative as novel SIRT6 inhibitor for sensitizing pancreatic cancer to gemcitabine

Pancreatic cancer is a highly aggressive cancer, and is primarily treated with gemcitabine, with increasing resistance. SIRT6 as a member of sirtuin family plays important roles in lifespan and diverse diseases, such as cancer, diabetes, inflammation and neurodegenerative diseases. Considering the role of SIRT6 in the cytoprotective effect, it might be a potential anticancer drug target, and is associated with resistance to anticancer therapy. However, very few SIRT6 inhibitors have been reported. Here, we reported the discovery of a pyrrole-pyridinimidazole derivative, 8a, as a new non-competitive SIRT6 inhibitor, and studied its roles and mechanisms in the antitumor activity and sensitization of pancreatic cancer to gemcitabine. Firstly, we found a potent SIRT6 inhibitor compound 8a by virtual screening and identified by molecular and cellular SIRT6 activity assays. 8a could effectively inhibit SIRT6 deacetylation activity with IC50 values of 7.46 ± 0.79 μM in FLUOR DE LYS assay, and 8a significantly increased the acetylation levels of H3 in cells. Then, we found that 8a could inhibit the cell proliferation and induce cell apoptosis in pancreatic cancer cells. We further demonstrate that 8a sensitize pancreatic cancer cells to gemcitabine via reversing the activation of PI3K/AKT/mTOR and ERK signaling pathways induced by gemcitabine and blocking the DNA damage repair pathway. Moreover, combination of 8a and gemcitabine induces cooperative antitumor activity in pancreatic cancer xenograft model in vivo. Overall, we demonstrate that 8a, a novel SIRT6 inhibitor, could be a promising potential drug candidate for pancreatic cancer treatment.