Preadipocytes potentiate melanoma progression and M2 macrophage polarization in the tumor microenvironment.

Melanoma, the deadliest skin cancer, originates from epidermal melanocytes. The influence of preadipocytes on melanoma is less understood. We co-cultured mouse melanoma B16 cells with 3T3L1 preadipocytes to form mixed spheroids and observed increased melanoma proliferation and growth compared to B16-only spheroids. Metastasis-related proteins YAP, TAZ, and PD-L1 levels were also higher in mixed spheroids. Treatment with exosome inhibitor GW4869 halted melanoma growth and reduced expression of these proteins, suggesting exosomal crosstalk between B16 and 3T3L1 cells. MiR-155 expression was significantly higher in mixed spheroids, and GW4869 reduced its levels. Additionally, co-culturing with Raw264.7 macrophage cells increased M2 markers IL-4 and CD206 in Raw264.7 cells, effects that were diminished by GW4869. These results indicate that preadipocytes may enhance melanoma progression and metastasis via exosomal interactions.

Microtubule acetylation induced by oxidative stress regulates subcellular distribution of lysosomal vesicles for amyloid-beta secretion.

Excessive production and accumulation of amyloid-beta (Aß) in the brain are one of the hallmarks of Alzheimer's disease (AD). Although oxidative stress is known to trigger and promote the progression of AD, the molecular relationship between oxidative stress and Aß production is not yet fully understood. In this study, we demonstrate that microtubule acetylation induced by oxidative stress plays a critical role in Aß production and secretion by altering the subcellular distribution of Aß precursor protein (APP)-containing lysosomal vesicles. Under oxidative stress, both H4-APPSwe/Ind and HEK293T-APPSwe/Ind cell lines showed increased microtubule acetylation and Aß secretion. Knockdown (KD) of alpha-tubulin N-acetyltransferase 1 (ATAT1) by using a lentiviral shRNA not only inhibited the generation of intermediate APP fragments, such as ß-CTF and AICD, but also suppressed Aß secretion. Oxidative stress promoted the dispersion of LAMP1-positive vesicles to the periphery of the cell through microtubule acetylation, leading to the formation of neutralized lysosomal vesicles (NLVs), which was inhibited by ATAT1 KD. Treatment of the cells with the dynein ATPase inhibitor EHNA or downregulation of LIS1, a regulator of dynein-mediated intracellular transport, increased the peripheral localization of NLVs and promoted Aß secretion, whereas KD of ADP ribosylation factor like GTPase 8B showed the opposite result. ATAT1 KD in the hippocampal region of the 5×FAD AD mouse model also showed significant reductions in Aß plaque accumulation and memory loss. Taken together, these findings suggest that oxidative stress-induced microtubule acetylation promotes the peripheral localization of lysosomal vesicles to form NLVs, thereby enhancing Aß secretion.

Applications of Bioinspired Platforms for Enhancing Immunomodulatory Function of Mesenchymal Stromal Cells.

Mesenchymal stromal cells (MSCs) have attracted scientific and medical interest due to their self-renewing properties, pluripotency, and paracrine function. However, one of the main limitations to the clinical application of MSCs is their loss of efficacy after transplantation in vivo. Various bioengineering technologies to provide stem cell niche-like conditions have the potential to overcome this limitation. Here, focusing on the stem cell niche microenvironment, studies to maximize the immunomodulatory potential of MSCs by controlling biomechanical stimuli, including shear stress, hydrostatic pressure, stretch, and biophysical cues, such as extracellular matrix mimetic substrates, are discussed. The application of biomechanical forces or biophysical cues to the stem cell microenvironment will be beneficial for enhancing the immunomodulatory function of MSCs during cultivation and overcoming the current limitations of MSC therapy.

Role of extrinsic physical cues in cancer progression.

The tumor microenvironment (TME) is a complex system composed of many cell types and an extracellular matrix (ECM). During tumorigenesis, cancer cells constantly interact with cellular components, biochemical cues, and the ECM in the TME, all of which make the environment favorable for cancer growth. Emerging evidence has revealed the importance of substrate elasticity and biomechanical forces in tumor progression and metastasis. However, the mechanisms underlying the cell response to mechanical signals-such as extrinsic mechanical forces and forces generated within the TME-are still relatively unknown. Moreover, having a deeper understanding of the mechanisms by which cancer cells sense mechanical forces and transmit signals to the cytoplasm would substantially help develop effective strategies for cancer treatment. This review provides an overview of biomechanical forces in the TME and the intracellular signaling pathways activated by mechanical cues as well as highlights the role of mechanotransductive pathways through mechanosensors that detect the altering biomechanical forces in the TME. as an adjuvant for cancer immunotherapy.[BMB Reports 2023; 56(5): 287-295].

Polypropylene microplastics promote metastatic features in human breast cancer.

Microplastics (MPs) are now a global issue due to increased plastic production and use. Recently, various studies have been performed in response to the human health risk assessment. However, these studies have focused on spherical MPs, which have smooth edges and a spherical shape and account for less than 1% of MPs in nature. Unfortunately, studies on fragment-type MPs are very limited and remain in the initial stages. In this study, we studied the effect that 16.4 µm fragment type polypropylene (PP) MPs, which have an irregular shape and sharp edges and form naturally in the environment, had on breast cancer. The detrimental effects of PPMPs on breast cancer metastasis were examined. Here, 1.6 mg/ml of PPMP, which does not induce cytotoxicity in MDA-MB-231, was used, and at this concentration, PPMP did not induce morphological changes or cellular migrating in the MDA-MB-231 and MCF-7 cells. However, PPMP incubation for 24 hours in the MDA-MB-231 cells significantly altered the level of cell cycle-related transcripts in an RNA-seq analysis. When confirmed by qRT-PCR, the gene expression of TMBIM6, AP2M1, and PTP4A2 was increased, while the transcript level of FTH1 was decreased. Further, secretion of the pro-inflammatory cytokine IL-6 from cancer cells was elevated with the incubation of PPMP for 12 hours. These results suggest that PPMP enhances metastasis-related gene expression and cytokines in breast cancer cells, exacerbating breast cancer metastasis.

Biomechanical forces in the aged brain: Relationship to AD.

The pathogenesis of neurodegenerative disorders, including Alzheimer's disease, has been studied with a focus on biochemical mechanisms, such as the amyloid-ß plaque deposition and removal. Recently, the importance of brain microenvironmental cues, which comprise the sophisticated cellular and fluid system, has been emphasized in the aged brain or in pathological conditions. Especially, substrate rigidity and biomechanical forces of the brain microenvironment determine the function of glial cells and neurons; furthermore, these microenvironmental cues change with age. However, our understanding of role of the biomechanical cues on glial cells and neurons is relatively poor. In this review, we briefly introduce an overview of biomechanical forces that present in the aged brain and its sensations, and then examine the brain in Alzheimer's disease, which constitutes a representative neurodegenerative disorder, with regard to changes in the biomechanical forces associated with disease and aging.

Fluid shear stress facilitates prostate cancer metastasis through Piezo1-Src-YAP axis.

AIMS: Mechanical forces surrounding solid tumors are pervasive in the tumor microenvironment (TME) and abnormally altered as solid tumors progress. Although it has been reported that biomechanical forces, including wall shear stress (WSS), enhance the metastatic features of cancer cells, its mechanism remains unknown. Here, we investigate how cancer cells sense mechanical stress and propagate signals in the TME. MAIN METHODS: Using a microfluidic device, interstitial fluid-mimicking flow (0.05 dyne cm-2) was applied to the human prostate cancer cell line PC3. Piezo1 siRNA and shRNA lentivirus were applied to PC3 cells to ablate Piezo1 expression. PC3-Luc2 cells expressing control shRNA or shPiezo1 lentivirus were administered into the prostate of BALB/c mice for orthotopic injection. KEY FINDING: Here, we show that Piezo1, a mechanosensitive ion channel, is activated by WSS in microfluidic channels. Moreover, Yoda1, a Piezo1 agonist, synergistically potentiates cancer cell motility and nuclear retention of YAP/TAZ via WSS. Also, Piezo1 increases Src phosphorylation, which activates YAP. Conversely, silencing Piezo1 significantly reduces cell motility and YAP/TAZ activity induced by WSS, and finally retards tumor growth and metastasis of administered PC3 cells in BALB/c mice. SIGNIFICANCE: Taken together, these results demonstrate that Piezo1 allows cancer cells to sense mechanical stimuli by altering the microenvironment during tumor progression and is a critical player in modulating cancer metastasis through the Piezo1-Src-YAP axis.

Biomechanical forces enhance directed migration and activation of bone marrow-derived dendritic cells.

Mechanical forces are pervasive in the inflammatory site where dendritic cells (DCs) are activated to migrate into draining lymph nodes. For example, fluid shear stress modulates the movement patterns of DCs, including directness and forward migration indices (FMIs), without chemokine effects. However, little is known about the effects of biomechanical forces on the activation of DCs. Accordingly, here we fabricated a microfluidics system to assess how biomechanical forces affect the migration and activity of DCs during inflammation. Based on the structure of edema, we proposed and experimentally analyzed a novel concept for a microchip model that mimicked such vascular architecture. The intensity of shear stress generated in our engineered chip was found as 0.2-0.6 dyne/cm2 by computational simulation; this value corresponded to inflammation in tissues. In this platform, the directness and FMIs of DCs were significantly increased, whereas the migration velocity of DCs was not altered by shear stress, indicating that mechanical stimuli influenced DC migration. Moreover, DCs with shear stress showed increased expression of the DC activation markers MHC class I and CD86 compared with DCs under static conditions. Taken together, these data suggest that the biomechanical forces are important to regulate the migration and activity of DCs.

Bone Marrow Mesenchymal Stromal Cells on Silk Fibroin Scaffolds to Attenuate Polymicrobial Sepsis Induced by Cecal Ligation and Puncture.

Suitable scaffolds with appropriate mechanical and biological properties can improve mesenchymal stromal cell (MSC) therapy. Because silk fibroins (SFs) are biocompatible materials, they were electrospun and applied as scaffolds for MSC therapy. Consequently, interferon (IFN)-primed human bone marrow MSCs on SF nanofibers were administered into a polymicrobial sepsis murine model. The IL-6 level gradually decreased from 40 ng/mL at 6 h after sepsis to 35 ng/mL at 24 h after sepsis. The IL-6 level was significantly low as 5 ng/mL in primed MSCs on SF nanofibers, and 15 ng/mL in primed MSCs on the control surface. In contrast to the acute response, inflammation-related factors, including HO-1 and COX-2 in chronic liver tissue, were effectively inhibited by MSCs on both SF nanofibers and the control surface at the 5-day mark after sepsis. An in vitro study indicated that the anti-inflammatory function of MSCs on SF nanofibers was mediated through enhanced COX-2-PGE2 production, as indomethacin completely abrogated PGE2 production and decreased the survival rate of septic mice. Thus, SF nanofiber scaffolds potentiated the anti-inflammatory and immunomodulatory functions of MSCs, and were beneficial as a culture platform for the cell therapy of inflammatory disorders.

Both Intracranial and Intravenous Administration of Functionalized Carbon Nanotubes Protect Dopaminergic Neuronal Death from 6-Hydroxydopamine.

PURPOSE: Although single-walled nanotubes (SWNTs) with functional groups have been suggested as a potential nanomedicine to treat neuronal disorders, effective routes to administer SWNTs have not been compared thus far. The blood-brain barrier is a considerable challenge for the development of brain-targeting drugs, and therefore functionalized SWNT routes of administration have been needed for testing Parkinson's disease (PD) treatment. Here, effective administration routes of functionalized SWNTs were evaluated in PD mouse model. METHODS: Three different administration routes were tested in PD mouse model. Functionalized SWNTs were injected directly into the lateral ventricle three days before (Method 1) or after (Method 2) 6-hydroxydopamine (6-OHDA) injection to compare the protective effects of SWNTs against dopaminergic neuronal death or functionalized SWNTs were injected intravenously at three and four days after 6-OHDA injection (Method 3). Asymmetric behaviors and histological assessment from all animals were performed at two weeks after 6-OHDA injection. RESULTS: Ventricular injections of SWNTs both before or after 6-OHDA exposure protected dopaminergic neurons both in the substantia nigra and striatum and alleviated rotational asymmetry behavior in PD mice. Moreover, intravenous administration of SWNTs three and four days after 6-OHDA injection also prevented neuronal death and PD mice behavioral impairment without apparent cytotoxicity after six months post-treatment. CONCLUSION: Our study demonstrates that functionalized SWNTs could effectively protect dopaminergic neurons through all administration routes examined herein. Therefore, SWNTs are promising nanomedicine agents by themselves or as therapeutic carriers to treat neuronal disorders such as PD.

Erratum to: Milk Containing BF-7 Enhances the Learning and Memory, Attention, and Mathematical Ability of Normal Persons.

[This corrects the article DOI: 10.5851/kosfa.2009.29.2.278.].

HS­146, a novel phosphoinositide 3­kinase α inhibitor, induces the apoptosis and inhibits the metastatic ability of human breast cancer cells.

The phosphoinositide 3­kinase (PI3K) signaling pathway plays an important role in human cancer as it regulates critical cellular functions, such as survival, proliferation and metabolism. In the present study, a novel PI3Kα inhibitor (HS­146) was synthesized and its anticancer effects on MCF­7, MDA­MB­231, SKBR3 and BT­474 human breast cancer cell lines were confirmed. HS­146 was found to be most effective in inhibiting the proliferation of MCF­7 cells and in inducing cell cycle arrest in the G0/G1 phase by downregulating cyclin D1, cyclin E, cyclin­dependent kinase (Cdk)2 and Cdk4, and upregulating p21Waf1/Cip1 protein levels in this cell line. The induction of apoptosis by HS­146 was confirmed by DAPI staining and western blot analysis. Cell shrinkage and nuclear condensation, which are typical morphological markers of apoptosis, were increased by HS­146 in the MCF­7 cells in a concentration­dependent manner, and HS­146 also increased the protein expression levels of cleaved poly(ADP­ribose) polymerase (PARP) and decreased the protein expression levels of Mcl­1 and caspase­7. In addition, HS­146 effectively decreased the phosphorylation levels of downstream PI3K effectors, such as Akt, mammalian target of rapamycin (mTOR), glycogen synthase kinase 3ß (GSK3ß), p70S6K1 and eukaryotic translation initiation factor 4E­binding protein 1 (4E­BP1). Hypoxia­inducible factor (HIF)­1α and vascular endothelial growth factor (VEGF) expression were also suppressed by HS­146 under hypoxic conditions, and HS­146 inhibited the migration and invasion of MCF­7 cells in a concentration­dependent manner. On the whole, the findings of the present study suggest that HS­146, a novel PI3Kα inhibitor, may be an effective novel therapeutic candidate that suppresses breast cancer proliferation and metastasis by inhibiting the PI3K/Akt/mTOR pathway.

Anti-tumor effects of the ethanolic extract of Trichosanthes kirilowii seeds in colorectal cancer.

BACKGROUND: Trichosanthis semen, the seeds of Trichosanthes kirilowii Maxim. or Trichosanthes rosthornii Harms, has long been used in Korean medicine to loosen bowels and relieve chronic constipation. Although the fruits and radixes of this medicinal herb and their constituents have been reported to exhibit therapeutic effects in various cancers, the anti-cancer effects of its seeds have been relatively less studied. In this study, we investigated the effects of an ethanolic extract of T. kirilowii seeds (TKSE) against colorectal cancer and its mechanism. METHODS: The anti-tumor effects of the TKSE were evaluated in HT-29 and CT-26 colorectal cancer cells and in a CT-26 tumor-bearing mouse model. RESULTS: TKSE suppressed the growth of HT-29 and CT-26 cells (both colorectal cancer cell lines) and the cytotoxic effect of TKSE was greater than that of 5-fluorouracil (5-Fu) in HT-29 cells. TKSE significantly induced mitochondrial membrane potential loss in HT-29 and CT-26 cells and dose-dependently inhibited Bcl-2 expression and induced the cleavages of caspase-3 and PARP. In particular, TKSE at 300 µg/mL induced nuclear condensation and fragmentation in HT-29 cells. Furthermore, TKSE dose-dependently inhibited activations of the Akt/mTOR and ERK pathways, and markedly induced the phosphorylation of AMPK. An AMPKα inhibitor (compound C) effectively blocked the TKSE-induced mitochondrial dysfunction. In addition, TKSE attenuated the hypoxia-inducible factor-1α/vascular endothelial growth factor signaling pathway in HT-29 cells under hypoxic-mimic conditions and inhibited migration and invasion. Oral administration of TKSE (100 or 300 mg/kg) inhibited tumor growth in a mouse CT-26 allograft model but was not as effective as 5-Fu (the positive control), which was administered intraperitoneally. In the same model, 5-Fu caused significant body weight loss, but no such loss was observed in TKSE-treated mice. CONCLUSION: Taken together, these results suggest TKSE has potent anti-tumor effects which might be partly due to the activation of AMPK, and the induction mitochondrial-mediated apoptosis in colorectal cancer cells. These findings provide scientific evidence supporting the potential use of TKSE as a complementary and alternative medicine for the treatment of colorectal cancer.

Silk fibroin scaffolds potentiate immunomodulatory function of human mesenchymal stromal cells.

Although mesenchymal stromal cells (MSCs) show great potential for use in regenerative medicine, their therapeutic efficacy remains limited because of their low adaptation efficiency and viability observed in clinical trials. To potentiate the adaptation and survival efficiency of MSCs after administration in vivo, silk fibroin nanofibers (SFNs) were applied as a scaffold. SFNs are biocompatible, biodegradable polymers with tunable architectures and mechanical properties. Treatment with interferon (IFN)-γ for 18 h increased the expression of immunomodulatory functional cytokines, IDO and COX2 in MSCs. Further, the MSCs grown on SFN sheets showed enhanced IDO1 and COX2 expression following IFN-γ treatment. MSCs showed significantly greater migratory ability on SFN sheets than on glass surfaces or PLGA control sheets. Though IFN-γ treatment slightly reduced the migration ability of MSCs cultured on glass or poly(lactic-co-glycolic acid) (PLGA) nanofiber sheets, it did not alter MSC motility on SFN sheets. Furthermore, MSCs cultured on SFN sheets dramatically suppressed TNF-α secretion from lipopolysaccharide-activated murine splenocytes, suggesting that the immunomodulatory function of MSCs was enhanced by the SFN sheets. Taken together, these data demonstrate that SFN sheets potentiate the reparative and regenerative properties of MSCs.

Improvement of andropause symptoms by dandelion and rooibos extract complex CRS-10 in aging male.

Many aging male suffer various andropause symptoms including loss of physical and mental activities. This study evaluated the putative alleviative effects of CRS-10 dandelion and rooibos extract complex (CRS-10) on the symptoms of andropause. The survival rate of TM3 Leydig cells (TM3 cells) treated with CRS-10 was measured based on typical physiological stress. After daily intake of CRS-10 for 4 weeks, the level of testosterone, physical activity and both the number and activity of sperm in older rats (18 weeks) were measured. Furthermore, thirty males were surveyed with AMS (Aging Males' Symptoms) questionnaire after intake of 400 mg of CRS-10. Overall, CRS-10 protected TM3 cells from serum restriction and oxidative stress via activation of ERK and Akt pathways. The level of testosterone and activation of spermatogenesis in rats were significantly enhanced. In addition, physical locomotion was markedly improved. Daily intake of 400 mg of CRS-10 improved the quality of life among agingmale respondents, according to a clinical survey using the AMS. The results indicate the potential of CRS-10 as a safe and efficacious natural substance for reducing or alleviating andropause symptoms.