Modulation of cell physiology under hypoxia in pancreatic cancer

The Effect of Ethanolic Extract of Brazilian Green Propolis and Artepillin C on Cytokine Secretion by Stage IV Glioma Cells Under Hypoxic and Normoxic Conditions

Background: The majority of gliomas are astrocytic in nature. Gliomas have the lowest survival rate among all tumors of the central nervous system (CNS), characterized by high aggressiveness and poor response to treatment. The tumor microenvironment is a source of cytokines such as IL-6, IFN-γ, VEGF, and PDGF-BB, secreted mainly by tumor and immune cells. These cytokines play a significant role in angiogenesis, invasion, and metastasis formation. In vitro and in vivo studies have shown that Brazilian green propolis, derived from Baccharis dracunculifolia DC and rich in artepillin C, exhibits anti-inflammatory, antimicrobial, chemopreventive, and anticancer activities. Additionally, it can penetrate the blood-brain barrier, demonstrating neuroprotective effects. The aim of the present study was to determine the concentration of selected cytokines produced by astrocytes of the CCF-STTG1 cell line, isolated from the brain of a patient with stage IV glioma (astrocytoma). Methods: The cytotoxicity of the EEP-B was evaluated using the MTT assay. Astrocytes were stimulated with LPS at a final concentration of 200 ng/mL and/or IFN-α at 100 U/mL, followed by incubation with EEP-B (25-50 µg/mL) and artepillin C (25-50 µg/mL) under 2-h hypoxia and normoxia conditions. Cytokine concentrations were measured using the xMAP Luminex Multiplex Immunoassay and the Multiplex Bead-Based Cytokine kit. Results: The absence of cytotoxic effects of EEP-B and artepillin C on human astrocytes of the CCF-STTG1 lineage was demonstrated. Stimulation with LPS, IFN-α, and their combination (LPS + IFN-α) significantly increased the secretion of the tested cytokines compared to the control cell line. The most pronounced and statistically significant reduction in cytokine levels, particularly IL-6 and VEGF, was observed following EEP-B treatment at both tested concentrations under both hypoxic and normoxic conditions. Conclusions: Brazilian green propolis may serve as a potential immunomodulator in combination therapies for gliomas of varying malignancy grades.

Quantifying the impact of metronomic chemotherapy chemo-switch regimen and the sequencing of chemotherapy and radiotherapy on pancreatic ductal adenocarcinoma treatment

Metronomic chemotherapy (MCT) is a novel chemotherapy approach characterized by a high-frequency, low-dose administration strategy. The "chemo-switch" regimen involves the sequential use of two dosing strategies: maximum tolerated dose (MTD) chemotherapy and MCT. For patients with pancreatic ductal adenocarcinoma (PDAC), selecting novel chemotherapy regimens appropriately according to their physical conditions may help address the challenges associated with MTD chemotherapy, such as excessive toxicity, prolonged tumor recovery, and suboptimal efficacy. There is currently limited research on mathematical models related to novel chemotherapy regimens and PDAC, as well as on the impact of different drug administration strategies and the sequence of chemoradiotherapy in combined treatment. To address these gaps, we propose a two-dimensional multiscale mathematical model. Initially, we model the individual effects of MTD chemotherapy, antiangiogenic therapy, and radiotherapy. Subsequently, we analyze the anti-tumor effects of various chemotherapy regimens and their underlying mechanisms. Furthermore, we assess how different drug administration regimens and the sequencing of chemotherapy and radiotherapy affect treatment outcomes. Simulation results indicate that, compared to standard MTD chemotherapy, using the MCT regimen or introducing MCT during MTD chemotherapy (chemo-switch regimen) demonstrates better anti-tumor efficacy and sustained tumor perfusion, enhancing drug accumulation within tumor regions. Combined therapy exhibits superior efficacy compared to monotherapy. Placing radiotherapy after anti-angiogenic therapy and chemotherapy suggests more effective in suppressing tumor growth and sustaining tumor perfusion. It is noteworthy that while this study focuses on PDAC treatment, its findings can be extrapolated to other fibrotic tumors, thereby facilitating similar analyses across different tumor types.

COMP promotes pancreatic fibrosis by activating pancreatic stellate cells through CD36-ERK/AKT signaling pathways

BACKGROUND

Pancreatic fibrosis is one of the most important pathological features of chronic pancreatitis (CP) and pancreatic stellate cells (PSCs) are the key cells of fibrosis. As an extracellular matrix (ECM) glycoprotein, cartilage oligomeric matrix protein (COMP) is critical for collagen assembly and ECM stability and recent studies showed that COMP exert promoting fibrosis effect in the skin, lungs and liver. However, the role of COMP in activation of PSCs and pancreatic fibrosis remain unclear. We aimed to investigate the role and specific mechanisms of COMP in regulating the profibrotic phenotype of PSCs and pancreatic fibrosis.

METHODS

ELISA method was used to determine serum COMP in patients with CP. Mice model of CP was established by repeated intraperitoneal injection of cerulein and pancreatic fibrosis was evaluated by Hematoxylin-Eosin staining (H&E) and Sirius red staining. Immunohistochemical staining was used to detect the expression changes of COMP and fibrosis marker such as α-SMA and Fibronectin in pancreatic tissue of mice. Cell Counting Kit-8, Wound Healing and Transwell assessed the proliferation and migration of human pancreatic stellate cells (HPSCs). Western blotting, qRT-PCR and immunofluorescence staining were performed to detect the expression of fibrosis marker, AKT and MAPK family proteins in HPSCs. RNA-seq omics analysis as well as small interfering RNA of COMP, recombinant human COMP (rCOMP), MEK inhibitors and PI3K inhibitors were used to study the effect and mechanism of COMP on activation of HPSCs.

RESULTS

ELISA showed that the expression of COMP significantly increased in the serum of CP patients. H&E and Sirius red staining analysis showed that there was a large amount of collagen deposition in the mice in the CP model group and high expression of COMP, α-SMA, Fibronectin and Vimentin were observed in fibrotic tissues. TGF-β1 stimulates the activation of HPSCs and increases the expression of COMP. Knockdown of COMP inhibited proliferation and migration of HPSCs. Further, RNA-seq omics analysis and validation experiments in vitro showed that rCOMP could significantly promote the proliferation and activation of HPSCs, which may be due to promoting the phosphorylation of ERK and AKT through membrane protein receptor CD36. rCOMP simultaneously increased the expression of α-SMA, Fibronectin and Collagen I in HPSCs.

CONCLUSION

In conclusion, this study showed that COMP was up-regulated in CP fibrotic tissues and COMP induced the activation, proliferation and migration of PSCs through the CD36-ERK/AKT signaling pathway. COMP may be a potential therapeutic candidate for the treatment of CP. Interfering with the expression of COMP or the communication between COMP and CD36 on PSCs may be the next direction for therapeutic research.

Targeting DNA topoisomerase IIα (TOP2A) in the hypoxic tumour microenvironment using unidirectional hypoxia-activated prodrugs (uHAPs)

The hypoxic tumour microenvironment (hTME), arising from inadequate and chaotic vascularity, can present a major obstacle for the treatment of solid tumours. Hypoxic tumour cells compromise responses to treatment since they can generate resistance to radiotherapy, chemotherapy and immunotherapy. The hTME impairs the delivery of a range of anti-cancer drugs, creates routes for metastasis and exerts selection pressures for aggressive phenotypes; these changes potentially occur within an immunosuppressed environment. Therapeutic strategies aimed at the hTME include targeting the molecular changes associated with hypoxia. An alternative approach is to exploit the prevailing lack of oxygen as a principle for the selective activation of prodrugs to target cellular components within the hTME. This review focuses on the design concepts and rationale for the use of unidirectional Hypoxia-Activated Prodrugs (uHAPs) to target the hTME as exemplified by the uHAPs AQ4N and OCT1002. These agents undergo irreversible reduction in a hypoxic environment to active forms that target DNA topoisomerase IIα (TOP2A). This nuclear enzyme is essential for cell division and is a recognised chemotherapeutic target. An activated uHAP interacts with the enzyme-DNA complex to induce DNA damage, cell cycle arrest and tumour cell death. uHAPs are designed to overcome the shortcomings of conventional HAPs and offer unique pharmacodynamic properties for effective targeting of TOP2A in the hTME. uHAP therapy in combination with standard of care treatments has the potential to enhance outcomes by co-addressing the therapeutic challenge presented by the hTME.

Effect of lncRNA00511 on Non-Small Cell Lung Cancer by Regulating miR-29b-3p

This study assessed the effect of LINC00511 on NSCLC cells through regulating miR-29b-3p/DRAM1 axis. LINC00511 expression in NSCLC tissue and para-carcinoma tissue was analyzed and its correlation with TNM stage was assessed. Lung carcinoma cells as A549 cells were cultivated in vitro and transfected with LINC00511 siRNA or plasmid with DRAM1 overexpression followed by analysis of LINC00511 and miR-184 expression by RT-PCR, cell proliferation and invasion, Bcl-2, Bax and DRAM1 expression by Western Blot. LINC00511 was significantly upregulated in NSCLC tissue and positively correlated with the TNM staging. However, miR-29b-3p was significantly downregulated in NSCLC tissue. The miR-29b-3p was a target of LINC00511. The DRAM1 was a target of miR-29b-3p. Downregulation of LINC00511 restrained proliferation and invasion of A549 cells and promoted cell apoptosis. The development of NSCLC could be prompted by increasing the presentation of LINC00511 through increasing presentation of DRAM1 and being targeted with miR-29b-3p. It could be restrained through reducing the presentation of LINC00511.

Hypoxia-driven metabolic heterogeneity and immune evasive behaviour of gastrointestinal cancers: Elements of a recipe for disaster

Gastrointestinal (GI) cancers refer to a group of malignancies associated with the GI tract (GIT). Like other solid tumors, hypoxic regions consistently feature inside the GI tumor microenvironment (TME) and contribute towards metabolic reprogramming of tumor-resident cells by modulating hypoxia-induced factors. We highlight here how the metabolic crosstalk between cancer cells and immune cells generate immunosuppressive environment inside hypoxic tumors. Given the fluctuating nature of tumor hypoxia, the metabolic fluxes between immune cells and cancer cells change dynamically. These changes alter cellular phenotypes and functions, resulting in the acceleration of cancer progression. These evolved properties of hypoxic tumors make metabolism-targeting monotherapy approaches or immunotherapy-measures unsuccessful. The current review highlights the advantages of combined immunometabolic treatment strategies to target hypoxic GI cancers and also identifies research areas to develop better combinational therapeutics for future.

Small extracellular vesicles (exosomes) and their cargo in pancreatic cancer: Key roles in the hallmarks of cancer

Pancreatic cancer (PC) is a devastating disease, offering poor mortality rates for patients. The current challenge being faced is the inability to diagnose patients in a timely manner, where potentially curative resection provides the best chance of survival. Recently, small/nanosized extracellular vesicles (sEVs), including exosomes, have gained significant preclinical and clinical attention due to their emerging roles in cancer progression and diagnosis. Extracellular vesicles (EVs) possess endogenous properties that offer stability and facilitate crossing of biological barriers for delivery of molecular cargo to cells, acting as a form of intercellular communication to regulate function and phenotype of recipient cells. This review provides an overview of the role of EVs, their subtypes and their oncogenic cargo (as characterised by targeted studies as well as agnostic '-omics' analyses) in the pathobiology of pancreatic cancer. The discussion covers the progress of 'omics technology' that has enabled elucidation of the molecular mechanisms that mediate the role of EVs and their cargo in pancreatic cancer progression.