Acidic pH derived from cancer cells as a double-edged knife modulates wound healing through DNA repair genes and autophagy

Exosomes Derived from Mouse Breast Carcinoma Cells Facilitate Diabetic Wound Healing

BACKGROUND

Exosomes derived from breast cancer have been reported to play a role in promoting cell proliferation, migration, and angiogenesis, which has the potential to accelerate the healing process of diabetic wounds. The aim of this investigation was to examine the function of exosomes originating from 4T1 mouse breast carcinoma cells (TEXs) in the process of diabetic wound healing.

METHODS

The assessment of primary mouse skin fibroblasts cell proliferation and migration was conducted through the utilization of CCK-8 and wound healing assays, while the tube formation of HUVECs was evaluated by tube formation assay. High-throughput sequencing, RT-qPCR and cell experiments were used to detect the roles of miR-126a-3p in HUVECs functions in vitro. The in vivo study employed a model of full-thickness excisional wounds in diabetic subjects to explore the potential therapeutic benefits of TEXs. Immunohistochemical and immunofluorescent techniques were utilized to evaluate histological changes in skin tissues.

RESULTS

The findings suggested that TEXs facilitate diabetic wound healing through the activation of cell migration, proliferation, and angiogenesis. An upregulation of miR-126a-3p has been observed in TEXs, and it has demonstrated efficient transferability from 4T1 cells to HUVEC cells. The activation of the PI3K/Akt pathway has been attributed to miR-126a-3p derived from TEXs.

CONCLUSIONS

The promotion of chronic wound healing can be facilitated by TEXs through the activation of cellular migration, proliferation, and angiogenesis. The activation of the PI3K/Akt pathway by miR-126a-3p originating from TEXs has been discovered, indicating a potential avenue for enhancing the regenerative capabilities of wounds treated with TEXs.

Cancer cells same as zombies reprogram normal cells via the secreted microenvironment

The cancer microenvironment plays a crucial role in promoting metastasis and malignancy even in normal cells. In the present study, the effect of acidic and conditioned media of cancer cells (MDA-MB-231), separately and in combination, was studied for the first time on the cell death mechanisms and DNA methylation of normal fibroblasts (NIH/3T3). Cell survival of conditioned media was rescued by the addition of acidic media to conditioned media, as shown by the results. Cell metabolic activity is deviated in a direction other than the Krebs cycle by acidic media The mitochondrial metabolic activity of all groups was enhanced over time, except for acidic media. Unlike the highest amount of ROS in conditioned media, its level decreased to the level of acidic media in the combination group. Furthermore, cells were deviated towards autophagy, rather than apoptosis, by the addition of acidic media to the conditioned media, unlike the conditioned media. Global DNA methylation analysis revealed significantly higher DNA hypomethylation in acidic media than in normal and combination media. Not only were cells treated with conditioned media rescued by acidic media, but also DNA hypomethylation and apoptosis in the combination group were decreased through epigenetic modifications. The acidic and conditioned media produced by cancer cells can remotely activate malignant signaling pathways, much like zombies, which can cause metabolic and epigenetic changes in normal cells.

Acidic Growth Conditions Promote Epithelial-to-Mesenchymal Transition to Select More Aggressive PDAC Cell Phenotypes In Vitro

Pancreatic Ductal Adenocarcinoma (PDAC) is characterized by an acidic microenvironment, which contributes to therapeutic failure. So far there is a lack of knowledge with respect to the role of the acidic microenvironment in the invasive process. This work aimed to study the phenotypic and genetic response of PDAC cells to acidic stress along the different stages of selection. To this end, we subjected the cells to short- and long-term acidic pressure and recovery to pH_e 7.4. This treatment aimed at mimicking PDAC edges and consequent cancer cell escape from the tumor. The impact of acidosis was assessed for cell morphology, proliferation, adhesion, migration, invasion, and epithelial-mesenchymal transition (EMT) via functional in vitro assays and RNA sequencing. Our results indicate that short acidic treatment limits growth, adhesion, invasion, and viability of PDAC cells. As the acid treatment progresses, it selects cancer cells with enhanced migration and invasion abilities induced by EMT, potentiating their metastatic potential when re-exposed to pH_e 7.4. The RNA-seq analysis of PANC-1 cells exposed to short-term acidosis and pH_e-selected recovered to pH_e 7.4 revealed distinct transcriptome rewiring. We describe an enrichment of genes relevant to proliferation, migration, EMT, and invasion in acid-selected cells. Our work clearly demonstrates that upon acidosis stress, PDAC cells acquire more invasive cell phenotypes by promoting EMT and thus paving the way for more aggressive cell phenotypes.

Camptothecin loaded casein nanosystem for tuning the therapeutic efficacy against highly metastatic triple-negative breast cancer cells

The heterogenic of TNBC and the side effects of chemo drugs lead to the failure of therapy. Protein-based nanoplatforms have emerged as an important domain in protein-engineered biomedicine for delivering anticancer therapeutics. Protein-based nanosystems are biocompatible and biodegradable, with a long half-life and high purity. TNBC is sensitive to DNA-damaging chemo drugs. In this study, we used 10-hydroxy camptothecin, which causes DNA damage in cancer cells. However, the inappropriate solubility and toxic side effects limit its application in cancer therapy. We encapsulated 10-Hydroxycamptothecin in biocompatible casein by synthesizing nanoparticles from it. The synthesized CS and CCS NPs showed excellent biocompatibility in fibroblast cell lines L929, NIH-3T3, and zebrafish embryos. Enhanced uptake of CCS NPs in zebrafish embryos and 4T1 cells, cancer cell toxicity of nearly 80-85%, sub-cellular mitochondrial localization, alterations of mitochondrial membrane potential, lysosomal localization, and reactive oxygen species generation that causes cancer cell apoptosis have been observed. Growth inhibition of 4T1 cell colonies and antimetastatic activity were also noted. Further upregulation of γ-H2AX which causes DNA damage, downregulation of the PARP protein related to DNA repair, and increased level of the CHOP protein marker for endoplasmic reticulum stress-mediated cell death were observed. The 3-D model of 4T1 cells exhibited deep tumor penetration with significant therapeutic efficacy for CCS NPs. These results imply that casein-based nanoformulation could open a new scope for safe and affordable cancer therapy in TNBC.

Anti-inflammatory ethosomal nanoformulation in combination with iontophoresis in chronic wound healing: An ex vivo study

Prescription of anti-inflammatory drugs may be considered as a promising strategy in chronic wound healing where the inflammatory disturbance has delayed the healing process. It seems that hydrocortisone 17-butyrate (HB17) would be promising in the form of a nano-formulation to enhance drug delivery efficacy. In the present study, transdermal delivery of nano-HB17 in combination with iontophoresis was investigated ex vivo. Ethosomal-HB17 was synthesised using lecithin, ethanol and cholesterol with a different ratio by hot method. The negative ethosomal-HB17 particle size was around 244 ± 4.3 nm with high stability of up to 30 days. Additionally, evaluated entrapment efficiency of HB17 in ethosomes by high performance liquid chromatography was 40.6 ± 2.21%. Moreover, the permeation speed and amount of H17B in complete-thickness rat skin in the presence and absence of iontophoresis showed that the penetration of free H17B and ethosomal-H17B formulations were zero and 7.98 μg/cm² in 120 min, respectively. Whereas in the case of applying iontophoresis, permeation amount obtained was zero and 19.69 μg/cm² in 30 min in free H17B and ethosomal-H17B formulations, respectively. It has been concluded that transdermal delivery of ethosomal-H17B is an effective strategy to enhance drug delivery and it will be improved when it is combined with iontophoresis.

Zwitterionic Hydrogel Activates Autophagy to Promote Extracellular Matrix Remodeling for Improved Pressure Ulcer Healing

Pressure ulcer (PU) is a worldwide problem that is hard to heal because of its prolonged inflammatory response and impaired ECM deposition caused by local hypoxia and repeated ischemia/reperfusion. Our previous study discovered that the non-fouling zwitterionic sulfated poly (sulfobetaine methacrylate) (SBMA) hydrogel can improve PU healing with rapid ECM rebuilding. However, the mechanism of the SBMA hydrogel in promoting ECM rebuilding is unclear. Therefore, in this work, the impact of the SBMA hydrogel on ECM reconstruction is comprehensively studied, and the underlying mechanism is intensively investigated in a rat PU model. The in vivo data demonstrate that compared to the PEG hydrogel, the SBMA hydrogel enhances the ECM remolding by the upregulation of fibronectin and laminin expression as well as the inhibition of MMP-2. Further investigation reveals that the decreased MMP-2 expression of zwitterionic SBMA hydrogel treatment is due to the activation of autophagy through the inhibited PI3K/Akt/mTOR signaling pathway and reduced inflammation. The association of autophagy with ECM remodeling may provide a way in guiding the design of biomaterial-based wound dressing for chronic wound repair.

Acidic pH derived from cancer cells as a double-edged knife modulates wound healing through DNA repair genes and autophagy

Wound healing is a sequester program that involves diverse cell signalling cascades. Notwithstanding, complete signal transduction pathways underpinning acidic milieu derived from cancer cells is not clear, yet. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, fluorescein diacetate/propidium iodide staining, and cell cycle flow cytometry revealed that acidic media decreased cell viability and cell number along with enhanced dead cells and S-phase arrest in normal fibroblasts. Notably, the trends of intracellular reactive oxygen species production and lactate dehydrogenase release significantly increased with time. It seems the downregulation of Klf4 is in part due to acidosis-induced DNA damage. It promoted cells towards S-phase arrest and diminished cell proliferation. Klf4 downregulation had a direct correlation with the P53 level while acidic microenvironment promotes cells towards cell death mechanisms including apoptosis and autophagy. Noteworthily, the unchanged levels of Rb and Mlh1 indicated in those genes had no dominant role in the repairing of DNA damage in fibroblasts treated with the acidic microenvironment. Therefore, cells owing to not entering to mitosis and accumulation of DNA damage were undergone cell death to preserve cell homeostasis. Since acidic media decreased the level of tumour suppressor and DNA repair genes and altered the normal survival pathways in fibroblasts, caution should be exercised to not lead to cancer rather than wound healing.