Angiogenesis and apoptosis

SLC2A3 is a Potential Factor for Head and Neck Squamous Cancer Development through Tumor Microenvironment Alteration

INTRODUCTION

Tumor immunity has garnered increasing attention in cancer treatment and progression. However, there is still a challenge in understanding the mechanisms of specific molecules affecting the clinical prognosis and tumor microenvironment (TME).

METHODS

Here, we applied the ESTIMATE algorithm to calculate the immune and stromal scores in 504 HNSC cases from TCGA. Patients were grouped according to the median value of the immune and stromal. Clinicopathological characteristics and differentially expressed genes (DEG) were analyzed. Subsequently, LASSO, COX regression, survival analysis, and clinicopathological characteristics were conducted. Subsequently, SLC2A3 was determined as a predictive factor that high expression of SLC2A3 at the mRNA and protein levels predicted a worse clinical prognosis. GSEA25099 was utilized for external validation of immune infiltration, while tissue PCR, IHC, and Western Blot were used to confirm the expression levels of SLC2A3.

RESULTS

A series of immune-infiltration analyses showed that SLC2A3 expression was negatively correlated with CD8+ T cells, significantly affecting the survival prognosis of HNSC. In the GSEA analysis, the high expression of SLC2A3 was mainly enriched for immune-related biological processes. Meanwhile, high expression of SLC2A3 possessed higher TIDE scores and was also strongly positively correlated with a series of immune checkpoints affecting survival prognosis, thus causing greater susceptibility to immune escape.

CONCLUSION

Conclusively, SLC2A3 is a potential oncogene and factor of HNSC development, notably by an altered state of the immune microenvironment, immune-suppressive regulation, and immune escape.

Endothelial progenitor cells as an angiogenic biomarker for the diagnosis and prognosis of lung cancer

Background

Angiogenesis is mediated by endothelial progenitor cells (EPCs) derived from bone-marrow. In this prospective study, we tried to investigate the clinical utility of circulating EPCs in lung cancer (LC) patients.

Materials and methods

Flow cytometry technique was used to assess circulating EPCs according to the immuno-phenotype CD45- CD34+ CD133+ CD146+ mononuclear cells. Sixty patients and 30 controls were included in this prospective study.

Results

The mean of baseline EPC numbers was significantly higher in LC patients than in controls (p =0.003). Pretreatment EPC values were significantly correlated with primary tumor size (p = 0.05) and tumor response (p = 0.04). Receiver operating characteristics (ROC) curves were plotted to discriminate EPC numbers between patients and controls. Using ROC analysis, the optimal cutoff value was 125 cells/mL with a sensitivity and a specificity for baseline EPCs of 76.7% and 63.3%, respectively. According to this cutoff value, basal EPC values were significantly correlated with primary tumor size (p = 0.047) and response to chemotherapy (p = 0.034). High EPC levels were significantly associated with longer progression-free survival (PFS) and overall survival (OS) duration (p = 0.0043 and p = 0.02, respectively).

Conclusion

Increased baseline EPC values seem to be a useful biomarker for the prediction of prognosis and tumor response in LC patients. Furthermore, high EPC levels at diagnosis might be an indicator of tumor growth and longer survival in LC patients.

Advancements in Understanding the Hide-and-Seek Strategy of Hibernating Breast Cancer Cells and Their Implications in Oncology from a Broader Perspective: A Comprehensive Overview

Despite recent advancements in technology, breast cancer still poses a significant threat, often resulting in fatal consequences. While early detection and treatments have shown some promise, many breast cancer patients continue to struggle with the persistent fear of the disease returning. This fear is valid, as breast cancer cells can lay dormant for years before remerging, evading traditional treatments like a game of hide and seek. The biology of these dormant breast cancer cells presents a crucial yet poorly understood challenge in clinical settings. In this review, we aim to explore the mysterious world of dormant breast cancer cells and their significant impact on patient outcomes and prognosis. We shed light on the elusive role of the G9a enzyme and many other epigenetic factors in breast cancer recurrence, highlighting its potential as a target for eliminating dormant cancer cells and preventing disease relapse. Through this comprehensive review, we not only emphasise the urgency of unravelling the dynamics of dormant breast cancer cells to improve patient outcomes and advance personalised oncology but also provide a guide for fellow researchers. By clearly outlining the clinical and research gaps surrounding dormant breast cancer cells from a molecular perspective, we aim to inspire further exploration of this critical area, ultimately leading to improved patient care and treatment strategies.

The Size Differences of Breast Cancer and Benign Tumors Measured by Two-Dimensional Ultrasound and Contrast-Enhanced Ultrasound

OBJECTIVES

Ultrasound (US) imaging has been observed to underestimate tumor size in clinical practice. This study aims to compare the size measurements of breast cancer and benign tumors using two-dimensional ultrasound (2DUS) and contrast-enhanced ultrasound (CEUS).

METHODS

The study included 42 clinically confirmed breast cancer and 47 benign breast tumors. Two experienced physicians independently measured the maximal longitudinal and transverse diameters of the masses in 2DUS and CEUS. All analyses were performed in R (4.2.2) and GraphPad Prism 6.

RESULTS

The maximal longitudinal and transverse diameters of breast cancer measured by CEUS were 26.61 ± 0.21% and 26.24 ± 0.19% larger compared with 2DUS, and benign breast tumors had an 11.74 ± 0.21% and 11.06 ± 0.14% increase in size compared with 2DUS. The area under the curve (AUC) of the receiver operating characteristic curve (ROC) for the difference between 2DUS and CEUS was 0.870 for longitudinal diameters (95% CI: 0.795-0.945, sensitivity 0.842, specificity 0.783, threshold value 0.215), and 0.863 for transverse diameters (95% CI: 0.785-0.942, sensitivity 0.667, specificity 0.936, threshold value 0.203).

CONCLUSIONS

The size measurements of both breast cancer and benign tumors were larger in CEUS compared with 2DUS, with CEUS measurements of breast cancer being more pronounced than those of benign breast tumors. These findings suggest that CEUS may provide a more precise assessment of tumor size, which is crucial for determining optimal treatment strategies and improving patient outcomes in breast cancer management.

An arresten-derived anti-angiogenic peptide triggers apoptotic cell death in endothelial cells

BACKGROUND

In recent years, anti-angiogenic peptides have received considerable attention as candidates for cancer treatment. Arresten is an angiogenesis inhibitor that cleaves from the α1 chain of type IV collagen and stimulates apoptosis in endothelial cells. We have recently indicated that a peptide corresponding to the amino acid 78 to 86 of arresten, so-called Ars, prevented the migration and tube formation of HUVECs and the colon carcinoma growth in mice significantly. The current study aimed to determine whether induction of apoptotic cell death in endothelial cells is one of the biochemical mechanisms of this anti-angiogenic peptide.

METHODS AND RESULTS

This hypothesis was assessed using the MTT assay, cell cycle analysis, Annexin V-FITC/PI staining, BCL2, CASP8, CASP9, p53, and CDKN2A gene expression studies as well as evaluating apoptosis in tumor tissues by TUNEL assay. Results demonstrated that 40 µM of Ars significantly stimulated 46.2% of early and late apoptosis in HUVECs compared to 13.6% in the untreated cells and did not significantly alter the cell cycle distribution. Moreover, BCL2 and CASP8 were down-regulated, while CASP9 and p53 were up-regulated in endothelial cells. CDKN2A gene expression, the regulator of G1 cell cycle arrest, was not significantly altered.

CONCLUSIONS

It might be suggested that Ars induced apoptosis in endothelial cells through the mitochondrial pathway and had no effect on the cell cycle. Besides, Ars induced apoptosis significantly in vivo. However, further studies are required to confirm the detailed molecular mechanism of Ars, this peptide has the potential to be optimized for clinical translations.

Eriocitrin Inhibits Angiogenesis by Targeting VEGFR2-Mediated PI3K/AKT/mTOR Signaling Pathways

Eriocitrin, a flavanone found in peppermint and citrus fruits, is known to possess many physiological activities. However, the anti-angiogenic effects of eriocitrin are yet to be fully elucidated. Therefore, the objective of this research was to explore the anti-angiogenic effects of eriocitrin both in vitro and in vivo as well as its underlying mechanism. Anti-angiogenic effects of eriocitrin were evaluated utilizing in vitro models of angiogenesis, including inhibition of tube formation, and induction of apoptosis in human umbilical vein endothelial cells (HUVECs). A chorioallantoic membrane (CAM) assay in chick embryos was also performed to evaluate the in vivo effects of eriocitrin on angiogenesis. Results showed significant eriocitrin effects on proliferation, tube formation, migration, and apoptosis in HUVECs. Furthermore, in vivo analysis revealed that eriocitrin significantly suppressed the formation of new blood vessels. In particular, it regulated MAPK/ERK signaling pathway and VEGFR2, inhibited the downstream PI3K/AKT/mTOR signaling pathway, and activated apoptosis signals such as caspase cascades. In HUVECs, the expression of matrix metalloproteinases (MMP-2 and MMP-9) exhibited an inhibitory effect on angiogenesis through the suppression of the signaling pathway. Therefore, eriocitrin presents potential for development into an antiangiogenic therapeutic agent.

The opposite role of lactate dehydrogenase a (LDHA) in cervical cancer under energy stress conditions

Due to insufficient and defective vascularization, the tumor microenvironment is often nutrient-depleted. LDHA has been demonstrated to play a tumor-promoting role by facilitating the glycolytic process. However, whether and how LDHA regulates cell survival in the nutrient-deficient tumor microenvironment is still unclear. Here, we sought to investigate the role and mechanism of LDHA in regulating cell survival and proliferation under energy stress conditions. Our results showed that the aerobic glycolysis levels, cell survival and proliferation of cervical cancer cells decreased significantly after inhibition of LDHA under normal culture condition while LDHA deficiency greatly inhibited glucose starvation-induced ferroptosis and promoted cell proliferation and tumor formation under energy stress conditions. Mechanistic studies suggested that glucose metabolism shifted from aerobic glycolysis to mitochondrial OXPHOS under energy stress conditions and LDHA knockdown increased accumulation of pyruvate in the cytosol, which entered the mitochondria and upregulated the level of oxaloacetate by phosphoenolpyruvate carboxylase (PC). Importantly, the increase in oxaloacetate production after absence of LDHA remarkably activated AMP-activated protein kinase (AMPK), which increased mitochondrial biogenesis and mitophagy, promoted mitochondrial homeostasis, thereby decreasing ROS level. Moreover, repression of lipogenesis by activation of AMPK led to elevated levels of reduced nicotinamide adenine dinucleotide phosphate (NADPH), which effectively resisted ROS-induced cell ferroptosis and enhanced cell survival under energy stress conditions. These results suggested that LDHA played an opposing role in survival and proliferation of cervical cancer cells under energy stress conditions, and inhibition of LDHA may not be a suitable treatment strategy for cervical cancer.

Targeting NEDD8-activating enzyme for cancer therapy: developments, clinical trials, challenges and future research directions

NEDDylation, a post-translational modification through three-step enzymatic cascades, plays crucial roles in the regulation of diverse biological processes. NEDD8-activating enzyme (NAE) as the only activation enzyme in the NEDDylation modification has become an attractive target to develop anticancer drugs. To date, numerous inhibitors or agonists targeting NAE have been developed. Among them, covalent NAE inhibitors such as MLN4924 and TAS4464 currently entered into clinical trials for cancer therapy, particularly for hematological tumors. This review explains the relationships between NEDDylation and cancers, structural characteristics of NAE and multistep mechanisms of NEDD8 activation by NAE. In addition, the potential approaches to discover NAE inhibitors and detailed pharmacological mechanisms of NAE inhibitors in the clinical stage are explored in depth. Importantly, we reasonably investigate the challenges of NAE inhibitors for cancer therapy and possible development directions of NAE-targeting drugs in the future.

Platelets and (Lymph)angiogenesis

The formation of new blood and lymphatic vessels is essential for both the development of multicellular organisms and (patho)physiological processes like wound repair and tumor growth. In the 1990s, circulating blood platelets were first postulated to regulate tumor angiogenesis by interacting with the endothelium and releasing angiogenic regulators from specialized α granules. Since then, many studies have validated the contributions of platelets to tumor angiogenesis, while uncovering novel roles for platelets in other angiogenic processes like wound resolution and retinal vascular disease. Although the majority of (lymph)angiogenesis occurs during development, platelets appear necessary for lymphatic but not vascular growth, implying their particular importance in pathological cases of adult angiogenesis. Future work is required to determine whether drugs targeting platelet production or function offer a clinically relevant tool to limit detrimental angiogenesis.

Chlorogenic acid promotes angiogenesis and attenuates apoptosis following cerebral ischaemia-reperfusion injury by regulating the PI3K-Akt signalling

CONTEXT

Chlorogenic acid (CGA) has good antioxidant effects, but its explicit mechanism in cerebral ischaemia-reperfusion injury is still uncertain.

OBJECTIVE

We studied the effect of CGA in human brain microvascular endothelial cells (HBMECs) under OGD/R damage.

MATERIALS AND METHODS

HBMECs in 4 groups were treated with oxygen-glucose deprivation/re-oxygenation (OGD/R) (4 + 24 h), normal no CGA treatment and different concentrations (20, 40 or 80 μM) of CGA. Male C57BL/6J mice were classified as sham, middle cerebral artery occlusion (MCAO), and MCAO + CGA (30 mg/kg/day) groups. Mice in the sham group were not subjected to MCAO. Cell viability, apoptosis, angiogenesis and related protein levels were investigated by CCK-8, flow cytometry, TUNEL staining, tube formation and western blot assays. Infarct volume of brain tissues was analyzed by TTC staining.

RESULTS

CGA curbed apoptosis (from 32.87% to 13.12% in flow cytometry; from 34.46% to 17.8% in TUNEL assay) but accelerated cell angiogenesis of HBMECs with OGD/R treatment. Moreover, CGA augmented activation of the PI3K-Akt signalling (p-PI3K/PI3K level, from 0.39 to 0.49; p-Akt/Akt level, from 0.52 to 0.81), and the effect of CGA on apoptosis and angiogenesis was abolished by an inhibitor of PI3K-Akt signalling. Furthermore, CGA attenuated infarct (from 41.26% to 22.21%) and apoptosis and promoted angiogenesis and activation of the PI3K/Akt signalling in MCAO-induced mice.

CONCLUSIONS

CGA effectively repressed apoptosis and promoted angiogenesis in OGD/R-treated HBMECs and MCAO-treated mice by modulating PI3K-Akt signalling. Our research provides a theoretical basis for the use of CGA in the treatment of ischaemic stroke.

Anticancer Activity, Mechanism, and Delivery of Allyl Isothiocyanate

Allyl isothiocyanate (AITC) is a phytochemical that is abundantly present in cruciferous vegetables of the Brassicaceae family, such as cabbage, broccoli, mustard, wasabi, and cauliflower. The pungent taste of these vegetables is mainly due to the content of AITC present in these vegetables. AITC is stored stably in the plant as its precursor sinigrin (a type of glucosinolate), which is physically separated from myrosin cells containing myrosinase. Upon tissue disruption, myrosinase gets released and hydrolyzes the sinigrin to produce AITC and by-products. AITC is an organosulfur compound, both an irritant and toxic, but it carries pharmacological properties, including anticancer, antibacterial, antifungal, and anti-inflammatory activities. Despite the promising anticancer effectiveness of AITC, its clinical application still possesses challenges due to several factors, i.e., low aqueous solubility, instability, and low bioavailability. In this review, the anticancer activity of AITC against several cancer models is summarized from the literature. Although the mechanism of action is still not fully understood, several pathways have been identified; these are discussed in this review. Not much attention has been given to the delivery of AITC, which hinders its clinical application. However, the few studies that have demonstrated the use of nanotechnology to facilitate the delivery of AITC are addressed.

ARHGEF2/EDN1 pathway participates in ER stress-related drug resistance of hepatocellular carcinoma by promoting angiogenesis and malignant proliferation

Endoplasmic reticulum (ER) stress is widely involved in the drug resistance of hepatocellular carcinoma (HCC), but the mechanism of ER stress-induced drug resistance involves multiple signaling pathways that cannot be fully explained. Exploring genes associated with ER stress could yield a novel therapeutic target for ER stress-induced drug resistance. By analyzing RNA-sequencing, ATAC-sequencing, and Chip-sequencing data of Tunicamycin (TM)-treated or untreated HCC cells, we found that Rho guanine nucleotide exchange factor 2 (ARHGEF2) is upregulated in HCC cells with ER stress. ARHGEF2 plays an active role in tumor malignant progression. Notwithstanding, no research has been done on the link between ER stress and ARHGEF2. The function of ARHGEF2 as a novel downstream effector of ER stress in the angiogenesis and treatment resistance of HCC was revealed in this work. ARHGEF2 overexpression was linked to malignant development and a poor prognosis in HCC. ER stress stimulates the expression of ARHGEF2 through upregulation of ZNF263. Elevated ARHGEF2 accelerates HCC angiogenesis via the EDN1 pathway, enhances HCC cell proliferation and tumor growth both in vitro and in vivo, and contributes to ER stress-related treatment resistance. HCC cell growth was more inhibited when ARHGEF2 knockdown was paired with targeted medicines. Collectively, we uncovered a previously hidden mechanism where ARHGEF2/EDN1 pathway promotes angiogenesis and participates in ER stress-related drug resistance in HCC.

Relationship between VEGF Family Members, Their Receptors and Cell Death in the Neoplastic Transformation of Colorectal Cancer

Colorectal cancer (CRC) is the second most common cause of cancer death in the world. Both modifiable and nonmodifiable risk factors play a significant role in the pathogenesis of this tumor. The diagnosis is usually made late due to limitations of screening tests; therefore, the scientists are looking for new diagnostic tools such as gene or miRNA expression or different proteins’ concentrations, e.g., vascular endothelial growth factor (VEGF) family members. The VEGF family (VEGF-A, VEGF-B, VEGF-C, VEGF-D and PlGF) plays a key role in the processes of blood vessel formation in embryonic development as well as in pathological angiogenesis and lymphangiogenesis, which allow the tumor to grow exponentially. Blockage of VEGF-related pathways seems to be a valid therapeutic target. It was suggested in recent studies, that besides already used drugs, e.g., bevacizumab, there are other agents with potential usefulness in anticancer activity such as miRNAs, TMEA, granzyme K, baicalein and arginine. Moreover, VEGF proteins were assessed to induce the expression of anti-apoptotic proteins such as BCL-2 and BAX. Therefore, investigations concerning the usefulness of VEGF family members, not only in the development but also in the therapy of CRC, in order to fully elucidate their role in carcinogenesis, are extremely important.

Incorporation of Functionalized Calcium Phosphate Nanoparticles in Living Cells

Intracellular calcium (Ca2+) is a key signaling element that is involved in a great variety of fundamental biological processes. Thus, Ca2+ deregulation would be involved in the cancer cell progression and damage of mitochondrial membrane and DNA, which lead to apoptosis and necrosis. In this study, we have prepared amorphous calcium phosphate nanoparticles (ACP NPs) for studied their incorporation by endocytosis or electroporation to epithelial, endothelial and fibroblast cells (MCF-7, HUVEC and COS-1 cells, respectively). Our results showed that internalized ACP NPs have cytotoxic effects as a consequence of the increase of the intracellular calcium content. The endocytosis pathways showed a greater cytotoxic effect since calcium ions could easily be released from the nanoparticles and be accumulated in the lysosomes and mitochondria. In addition, the cytotoxic effect could be reversed when calcium ion was chelated with ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA). Modification of ACP NPs by coating with different compounds based on phosphates was also evaluated. The results indicated a reduction of the cytotoxic effect, in the order polyphosphate < phosphonic acid < orthophosphate. A differential cytotoxic effect of ACP-NPs was observed in function of the cell type; the cytotoxic effect can be ordered as i.e., HUVEC > COS-1 > MCF-7. The greater cytotoxic effect caused by the increase of intracellular calcium that is observed in normal cells and the greater resistance of cancer cells suggests new perspectives for cancer research.

β-Caryophyllene Induces Apoptosis and Inhibits Angiogenesis in Colorectal Cancer Models

Beta-Caryophyllene (BCP), a naturally occurring sesquiterpene abundantly found in cloves, hops, and cannabis, is the active candidate of a relatively new group of vascular-inhibiting compounds that aim to block existing tumor blood vessels. Previously, we have reported the anti-cancer properties of BCP by utilizing a series of in-vitro anti-tumor-related assays using human colorectal carcinoma cells. The present study aimed to investigate the effects of BCP on in-vitro, ex-vivo, and in-vivo models of anti-angiogenic assays and evaluate its anti-cancer activity in xenograft tumor (both ectopic and orthotopic) mice models of human colorectal cancer. Computational structural analysis and an apoptosis antibody array were also performed to understand the molecular players underlying this effect. BCP exhibited strong anti-angiogenic activity by blocking the migration of endothelial cells, tube-like network formation, suppression of vascular endothelial growth factor (VEGF) secretion from human umbilical vein endothelial cells and sprouting of rat aorta microvessels. BCP has a probable binding at Site#0 on the surface of VEGFR2. Moreover, BCP significantly deformed the vascularization architecture compared to the negative control in a chick embryo chorioallantoic membrane assay. BCP showed a remarkable reduction in tumor size and fluorescence molecular tomography signal intensity in all the mice treated with BCP, in a dose-dependent relationship, in ectopic and orthotopic tumor xenograft models, respectively. The histological analysis of the tumor from BCP-treated mice revealed a clear reduction of the density of vascularization. In addition, BCP induced apoptosis through downregulation of HSP60, HTRA, survivin, and XIAP, along with the upregulation of p21 expressions. These results suggest that BCP acts at multiple stages of angiogenesis and could be used as a promising therapeutic candidate to halt the growth of colorectal tumor cells.

Cancer-Associated Fibroblasts Facilitate Squamous Cell Carcinoma Lung Metastasis in Mice by Providing TGFβ-Mediated Cancer Stem Cell Niche

Cancer-associated fibroblasts (CAFs) have been shown to enhance squamous cell carcinoma (SCC) growth, but it is unclear whether they promote SCC lung metastasis. We generated CAFs from K15.KrasG12D.Smad4-/- mouse SCCs. RNA expression analyses demonstrated that CAFs had enriched transforming growth factor-beta (TGFβ) signaling compared to normal tissue-associated fibroblasts (NAFs), therefore we assessed how TGFβ-enriched CAFs impact SCC metastasis. We co-injected SCC cells with CAFs to the skin, tail vein, or the lung to mimic sequential steps of lung metastasis. CAFs increased SCC volume only in lung co-transplantations, characterized with increased proliferation and angiogenesis and decreased apoptosis compared to NAF co-transplanted SCCs. These CAF effects were attenuated by a clinically relevant TGFβ receptor inhibitor, suggesting that CAFs facilitated TGFβ-dependent SCC cell seeding and survival in the lung. CAFs also increased tumor volume when co-transplanted to the lung with limiting numbers of SCC cancer stem cells (CSCs). In vitro, CSC sphere formation and invasion were increased either with co-cultured CAFs or with CAF conditioned media (which contains the highest TGFβ1 concentration) and these CAF effects were blocked by TGFβ inhibition. Further, TGFβ activation was higher in primary human oral SCCs with lung metastasis than SCCs without lung metastasis. Similarly, TGFβ activation was detected in the lungs of mice with micrometastasis. Our data suggest that TGFβ-enriched CAFs play a causal role in CSC seeding and expansion in the lung during SCC metastasis, providing a prognostic marker and therapeutic target for SCC lung metastasis.

Anti-angiogenesis Function of Ononin via Suppressing the MEK/Erk Signaling Pathway

Angiogenesis is a complicated pathological process and plays an important role in modulating tumor development. Flavonoids, sharing the basic functional group with estrogen, have been utilized as chemopreventive agents to inhibit endothelial cell angiogenesis and also suppress tumor cell proliferation. Ononin, also referred to as formononetin-7-O-β-d-glucoside, is one of the bioactive chemicals found within many functional food or plants. The anticancer functions of ononin have been reported both in vitro and in vivo. However, the anti-angiogenetic properties of ononin have not been reported. The possible efficacies of ononin against angiogenesis was verified in cultured endothelial cells. Ononin suppressed vascular endothelial growth factor (VEGF)-induced HUVEC migration, invasion. and tube formation activity after 48 h. The apoptosis rate and specific markers, i.e., Bax/Bc-2 ratio, cleaved caspase 3/9 (Cl-caspase 3/9), and cytochrome c (Cyto c), were enhanced in the ononin-treated group. On the other hand, the protein expressions levels of hypoxia-inducible factor 1α (HIF-1α), mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK), and vascular endothelial growth factor receptor 2 (VEGFR2) were restricted after ononin treatment for 2 days in VEGF-pretreated endothelial cells. In summary, ononin acts as a candidate for angiogenetic-related disease prevention and treatment.

Poly-l-Lysine inhibits VEGF and c-Myc mediated tumor-angiogenesis and induces apoptosis in 2D and 3D tumor microenvironment of both MDA-MB-231 and B16F10 induced mice model

Cancer is a widespread disease that has shown promising mortality worldwide. Our previous study has been shown the efficacy of Poly-l-lysine (PLL) as a promising cytotoxic effect against cancer cells. However, exact-mechanism of PLL in 3D physiological relevant tumor-microenvironment and against tumor-angiogenesis has never been analysed. In this study, we have investigated apoptotic efficacy of PLL, if any in opposition to proliferative aggressive cancer cell MDA-MB-231 both 2D and-3D cell culture conditions. Furthermore, PLL was administered in B16F10 murine melanoma cells induced BALB/c mice model. The study has been designed through transcription and translation level of PLL-induced tumor-angiogenesis and apoptotic gene-expression modulation level and various relevant histological studies in comparison with untreated control. Studies have shown anti-proliferative and anti-tumor angiogenic efficacy of PLL better in in-vitro 3D tumor-microenvironment against MDA-MB-231 breast cancer cells. Furthermore, in-vivo model, PLL was found to suppress tumorigenesis process at minimum dose. PLL found to induce apoptosis through-upregulation of cytosolic-cytochrome-C, caspase-3 and PARP activations when administered in B16F10 induced in-vivo tumor. In blocking proliferation and tumor-angiogenesis, PLL was found to be effective as it significantly downregulated activity of VEGF, VEGFR2, Ki-67 and c-Myc expression. As PLL blocked tumor progression and induced DNA-break, also upregulated apoptotic process and recovered tissue architecture as revealed from histological study in comparison with untreated control. Overall PLL was found to be a promising anti-tumor angiogenic and anti-proliferative drug that was effective both in in-vitro breast cancer 3D tumor-microenvironment and in-vivo metastatic-mice-model.

Cell death pathways and viruses: Role of microRNAs

Viral infections lead to the death of more than a million people each year around the world, both directly and indirectly. Viruses interfere with many cell functions, particularly critical pathways for cell death, by affecting various intracellular mediators. MicroRNAs (miRNAs) are a major example of these mediators because they are involved in many (if not most) cellular mechanisms. Virus-regulated miRNAs have been implicated in three cell death pathways, namely, apoptosis, autophagy, and anoikis. Several molecules (e.g., BECN1 and B cell lymphoma 2 [BCL2] family members) are involved in both apoptosis and autophagy, while activation of anoikis leads to cell death similar to apoptosis. These mechanistic similarities suggest that common regulators, including some miRNAs (e.g., miR-21 and miR-192), are involved in different cell death pathways. Because the balance between cell proliferation and cell death is pivotal to the homeostasis of the human body, miRNAs that regulate cell death pathways have drawn much attention from researchers. miR-21 is regulated by several viruses and can affect both apoptosis and anoikis via modulating various targets, such as PDCD4, PTEN, interleukin (IL)-12, Maspin, and Fas-L. miR-34 can be downregulated by viral infection and has different effects on apoptosis, depending on the type of virus and/or host cell. The present review summarizes the existing knowledge on virus-regulated miRNAs involved in the modulation of cell death pathways. Understanding the mechanisms for virus-mediated regulation of cell death pathways could provide valuable information to improve the diagnosis and treatment of many viral diseases.

Size measurements of hepatocellular carcinoma: comparisons between contrast and two-dimensional ultrasound

Background

Ultrasound (US) imaging is known to underestimate tumor size in clinical. This study is aimed to compare the size measurements of hepatocellular carcinoma (HCC) in three US imaging modalities, i.e. two-dimensional (2D) imaging, the arterial phase (AP) and the late phase (LP) imaging of contrast-enhanced US (CEUS).

Methods

Fifty-eight clinically proved HCC patients were included. The 2D and CEUS imaging were performed with Siemens S2000, Philips iu22 and BioSound Twice. 2.5 mL of SonoVue® was injected for every CEUS performance. Two physicians measured the maximal longitudinal and the transverse diameters of the tumors in 2D, the AP and the LP of CEUS from one image section. The three measurements were compared by paired t test.

Results

The mean longitudinal diameter of HCC appeared to be maximal in the AP (4.73 ± 2.04 cm) of CEUS and minimal in the LP (3.98 ± 1.99 cm) of CEUS. The 2D diameter (4.26 ± 2.07 cm) was in the middle between two CEUS measurements. There were significant differences between any two measurements.

Conclusion

There is size difference between the three kinds of HCC measurement. It appeared to be maximal in the AP of CEUS and minimal in the LP. The 2D diameter was in the middle.

Construction of biomimetic silver nanoparticles in the treatment of lymphoma

Lymphoma is a well-known malignant tumor in the human body. Although many anticancer drugs have been developed to improve the survival rate of patients, about 40% of patients continue to be recurrent or refractory, a key issue needing remedy. Therefore, it is necessary to identify alternative treatments to reduce the disease's mortality. To this effect, a new type of anti-lymphoma nanocomplex FA@RBCm-AgNPs was prepared using AgNPs as the core of nanoparticles along with the targeting molecule folic acid inserted erythrocyte membrane as the shell. The biomimetic properties of red blood cell membrane (RBCm) endow F-RAN with good biocompatibility as well as the ability to evade clearance of the reticuloendothelial system. In addition, F-RAN was modified with folic acid to actively and selectively identify tumor cells. In vivo and in vitro experiments demonstrate that F-RAN can inhibit lymphoma cells and induce apoptosis of stem cells while promoting apoptosis of lymphoma with no obvious side effects. Hence, F-RAN may serve as a new treatment for lymphoma.

Perfluorocarbons-Based 19F Magnetic Resonance Imaging in Biomedicine

Fluorine-19 (¹⁹F) magnetic resonance (MR) molecular imaging is a promising noninvasive and quantitative molecular imaging approach with intensive research due to the high sensitivity and low endogenous background signal of the ¹⁹F atom in vivo. Perfluorocarbons (PFCs) have been used as blood substitutes since 1970s. More recently, a variety of PFC nanoparticles have been designed for the detection and imaging of physiological and pathological changes. These molecular imaging probes have been developed to label cells, target specific epitopes in tumors, monitor the prognosis and therapy efficacy and quantitate characterization of tumors and changes in tumor microenvironment noninvasively, therefore, significantly improving the prognosis and therapy efficacy. Herein, we discuss the recent development and applications of ¹⁹F MR techniques with PFC nanoparticles in biomedicine, with particular emphasis on ligand-targeted and quantitative ¹⁹F MR imaging approaches for tumor detection, oxygenation measurement, smart stimulus response and therapy efficacy monitoring, et al.

Chronic exposure of human glioblastoma tumors to low concentrations of a pesticide mixture induced multidrug resistance against chemotherapy agents

Recent evidence indicates that chronic, low-dose exposure to mixtures of pesticides can cause adverse responses in a variety of cells, tissues and organs, although interactions between pesticides circulating in the blood and cancer cells remain largely unexplored. The aim of this study was to investigate the potential of a mixture of four pesticides to induce multidrug resistance against the chemotherapeutic agents cisplatin, 5-fluorouracil and temozolomide in the human U87 glioblastoma cell line, and to explore the molecular mechanisms underlying this resistance. We found that the repeated administration of the pesticide mixture (containing the insecticides chlorpyrifos-ethyl and deltamethrin, the fungicide metiram, and the herbicide glyphosate) induced a strong drug resistance in U87 cells. The resistance was durable and transferred to subsequent cell generations. In addition, we detected a significant over-expression of the ATP-binding cassette (ABC) membrane transporters P-gp/ABCB1 and BRCP/ABCG2 as well as a glutathione-S-transferase (GST)/M1-type cellular detoxification function, known to have important roles in multidrug resistance, thus providing molecular support for the acquired multidrug resistance phenotype and shedding light on the mechanism of resistance. We further determined that there was lower mortality in the resistant brain tumor cells and that the mitochondrial apoptosis pathway was activated at a lower rate after chemotherapy compared to non-resistant control cells. In addition, multidrug-resistant cells were found to have both higher motility and wound-healing properties, suggesting a greater metastatic potential. Our results suggest that the investigation of P-gp, BRCP and GST/M1 multidrug resistance gene expression and/or protein levels in biopsy specimens of brain tumor patients who were at risk of pesticide exposure could be beneficial in determining chemotherapy dose and prolonging patient survival.

RENISUS Plants and Their Potential Antitumor Effects in Clinical Trials and Registered Patents

Cancer is a significant cause of morbidity and mortality. Scientific advances, coupled with potential flaws in current treatments, are driving research into the discovery of new bioactive molecules. This systematic review focused on scientific studies with clinical trials and patents registered on the National Relation of Medicinal Plants of Interest to the Unified Health System (RENISUS) plants (or derivative compounds) with antitumor potential. Studies with 19 different forms of cancer were found, the prostate being the organ with the highest research incidence and the species Glycine max, Curcuma longa, and Zingiber officinale, beside the phytochemicals curcumin and soy isoflavone were the most tested in clinical trials/patents.

Robustaflavone induces G0/G1 cell cycle arrest and apoptosis in human umbilical vein endothelial cells and exhibits anti-angiogenic effects in vivo

We investigated the anti-angiogenic and pro-apoptotic effects of robustaflavone (RF), a naturally occurring biflavonoid, on human umbilical vein endothelial cells (HUVECs). RF inhibited HUVEC proliferation and showed cytotoxicity that inhibited HUVEC viability. RF-induced apoptosis was characterized by flow cytometry and caspase 3 analysis. We found that RF increased the number of sub-G1 cells and terminal deoxynucleotidyl transferase dUTP nick end-labeled cells. Additionally, RF induced caspase 3 and poly (ADP-ribose) polymerase activation. Potential molecular targets were identified using a human apoptosis antibody array. RF upregulated Bax, Bad, cleaved caspase 3, p21, and phosphorylated p53 levels. RF induced mitochondrial membrane potential loss and the release of cytochrome c and apoptosis-inducing factor. Cell cycle arrest at G0/G1 phase and the downregulation of Cdk4, Cdk6, and cyclin D1 expression were induced by RF. In vivo anti-angiogenic effects were investigated using a tumor allograft animal model and a Matrigel plug assay. RF reduced the volumes and weights of CT-26 cell-derived tumors. The blood vessel density was significantly decreased in RF-treated tumors. RF also inhibited VEGF-A-stimulated blood vessel formation in vivo in Matrigel plugs. These results suggest that RF can potentially inhibit angiogenesis-dependent tumor growth and metastasis.

Resistance Mechanisms to Anti-angiogenic Therapies in Cancer

Tumor growth and metastasis rely on tumor vascular network for the adequate supply of oxygen and nutrients. Tumor angiogenesis relies on a highly complex program of growth factor signaling, endothelial cell (EC) proliferation, extracellular matrix (ECM) remodeling, and stromal cell interactions. Numerous pro-angiogenic drivers have been identified, the most important of which is the vascular endothelial growth factor (VEGF). The importance of pro-angiogenic inducers in tumor growth, invasion and extravasation make them an excellent therapeutic target in several types of cancers. Hence, the number of anti-angiogenic agents developed for cancer treatment has risen over the past decade, with at least eighty drugs being investigated in preclinical studies and phase I-III clinical trials. To date, the most common approaches to the inhibition of the VEGF axis include the blockade of VEGF receptors (VEGFRs) or ligands by neutralizing antibodies, as well as the inhibition of receptor tyrosine kinase (RTK) enzymes. Despite promising preclinical results, anti-angiogenic monotherapies led only to mild clinical benefits. The minimal benefits could be secondary to primary or acquired resistance, through the activation of alternative mechanisms that sustain tumor vascularization and growth. Mechanisms of resistance are categorized into VEGF-dependent alterations, non-VEGF pathways and stromal cell interactions. Thus, complementary approaches such as the combination of these inhibitors with agents targeting alternative mechanisms of blood vessel formation are urgently needed. This review provides an updated overview on the pathophysiology of angiogenesis during tumor growth. It also sheds light on the different pro-angiogenic and anti-angiogenic agents that have been developed to date. Finally, it highlights the preclinical evidence for mechanisms of angiogenic resistance and suggests novel therapeutic approaches that might be exploited with the ultimate aim of overcoming resistance and improving clinical outcomes for patients with cancer.

The Outcomes of Switching from Short- to Long-Term Intravitreal Corticosteroid Implant Therapy in Patients with Diabetic Macular Edema

BACKGROUND

First-line treatment for diabetic macular edema (DME) is usually with antivascular endothelial growth factor agents, followed by intravitreal corticosteroids as a second-line treatment option. Long-term corticosteroids may offer quality of life and effectiveness benefits over short-term implants.

OBJECTIVES

To evaluate outcomes of patients with persistent or recurrent DME who switched from a short-term (dexamethasone) to a long-term (fluocinolone acetonide, FAc) corticosteroid intravitreal implant in a real-world setting.

METHODS

This is a retrospective study in 9 Portuguese centers. An FAc intravitreal implant was administered according to product labeling. Effectiveness outcomes were mean change in visual acuity (VA; ETDRS letters), central retinal thickness (CRT; µm), and macular volume (MV; mm3). The safety outcome was mean change in intraocular pressure (IOP; mm Hg). All were analyzed at months 1 and 3, and then quarterly until month 24 after implantation.

RESULTS

Forty-four eyes from 36 patients were analyzed. Mean duration of DME was 3.3 ± 1.9 years, and mean follow-up was 8 months. From baseline following FAc implantation, VA increased significantly at months 1 and 6 (mean +6.82 and +13.02 letters, respectively; p = 0.005), and last observation carried forward (LOCF; mean +8.3 letters; p = 0.002). CRT improved significantly at months 1 and 6 (mean -71.81 and -170.77 µm, respectively; p = 0.001), and LOCF (mean -121.46 µm; p = 0.001). MV was consistently, but not significantly, decreased from baseline to LOCF (mean -0.69 mm3; p = 0.062). The mean change in IOP was -0.25 and +0.88 mm Hg at months 1 and 6, respectively (p = 0.268), and +1.86 mm Hg at LOCF (p = 0.036). Increases were controlled with topical medication in most cases.

CONCLUSIONS

The FAc intravitreal implant is effective in patients previously treated with short-term corticosteroid implants. Thus, after a suboptimal response to antiangiogenics or a short-term corticosteroid, a single FAc implant may be considered an effective and tolerable treatment that can improve long-term outcomes for patients with sight-threatening DME.

The pro-tumorigenic host response to cancer therapies

Resistance to cancer therapy remains a major challenge in clinical oncology. Although the initial treatment phase is often successful, eventual resistance, characterized by tumour relapse or spread, is discouraging. The majority of studies devoted to investigating the basis of resistance have focused on tumour-related changes that contribute to therapy resistance and tumour aggressiveness. However, over the last decade, the diverse roles of various host cells in promoting therapy resistance have become more appreciated. A growing body of evidence demonstrates that cancer therapy can induce host-mediated local and systemic responses, many of which shift the delicate balance within the tumour microenvironment, ultimately facilitating or supporting tumour progression. In this Review, recent advances in understanding how the host response to different cancer therapies may promote therapy resistance are discussed, with a focus on therapy-induced immunological, angiogenic and metastatic effects. Also summarized is the potential of evaluating the host response to cancer therapy in an era of precision medicine in oncology.

Antiangiogenic Effects of Coumarins against Cancer: From Chemistry to Medicine

Angiogenesis, the process of formation and recruitment of new blood vessels from pre-existing vessels, plays an important role in the development of cancer. Therefore, the use of antiangiogenic agents is one of the most critical strategies for the treatment of cancer. In addition, the complexity of cancer pathogenicity raises the need for multi-targeting agents. Coumarins are multi-targeting natural agents belonging to the class of benzopyrones. Coumarins have several biological and pharmacological effects, including antimicrobial, antioxidant, anti-inflammation, anticoagulant, anxiolytic, analgesic, and anticancer properties. Several reports have shown that the anticancer effect of coumarins and their derivatives are mediated through targeting angiogenesis by modulating the functions of vascular endothelial growth factor as well as vascular endothelial growth factor receptor 2, which are involved in cancer pathogenesis. In the present review, we focus on the antiangiogenic effects of coumarins and related structure-activity relationships with particular emphasis on cancer.

Zileuton, a 5-Lipoxygenase Inhibitor, Exerts Anti-Angiogenic Effect by Inducing Apoptosis of HUVEC via BK Channel Activation

The arachidonic acid metabolism through 5-lipoxygenase (5-LO) pathways is involved in modulating both tumorigenesis and angiogenesis. Although anti-carcinogenic activities of certain 5-LO inhibitors have been reported, the role of zileuton, a well known 5-LO inhibitor, on the endothelial cell proliferation and angiogenesis has not been fully elucidated. Here, we report that zileuton has an anti-angiogenic effect, and the underlying mechanisms involved activation of the large-conductance Ca²⁺-activated K⁺ (BK) channel. Our results show that zileuton significantly prevented vascular endothelial growth factor (VEGF)-induced proliferation of human umbilical vein endothelial cells (HUVECs) in vitro, as well as in vivo. However, such anti-angiogenic effect of zileuton was abolished by iberiotoxin (IBTX), a BK channel blocker, suggesting zileuton-induced activation of BK channel was critical for the observed anti-angiogenic effect of zileuton. Furthermore, the anti-angiogenic effect of zileuton was, at least, due to the activation of pro-apoptotic signaling cascades which was also abolished by IBTX. Additionally, zileuton suppressed the expression of VCAM-1, ICAM-1, ETS related gene (Erg) and the production of nitric oxide (NO). Taken together, our results show that zileuton prevents angiogenesis by activating the BK channel dependent-apoptotic pathway, thus highlighting its therapeutic capacity in angiogenesis-related diseases, such as cancer.

Differentiation of Vascular Characteristics Using Contrast-Enhanced Ultrasound Imaging

Ultrasound contrast imaging has been used to assess tumour growth and regression by assessing the flow through the macro- and micro-vasculature. Our aim was to differentiate the blood kinetics of vessels such as veins, arteries and microvasculature within the limits of the spatial resolution of contrast-enhanced ultrasound imaging. The highly vascularised ovine ovary was used as a biological model. Perfusion of the ovary with SonoVue was recorded with a Philips iU22 scanner in contrast imaging mode. One ewe was treated with prostaglandin to induce vascular regression. Time-intensity curves (TIC) for different regions of interest were obtained, a lognormal model was fitted and flow parameters calculated. Parametric maps of the whole imaging plane were generated for 2 × 2 pixel regions of interest. Further analysis of TICs from selected locations helped specify parameters associated with differentiation into four categories of vessels (arteries, veins, medium-sized vessels and micro-vessels). Time-dependent parameters were associated with large veins, whereas intensity-dependent parameters were associated with large arteries. Further development may enable automation of the technique as an efficient way of monitoring vessel distributions in a clinical setting using currently available scanners.

Differentially Expressed Proteins in Primary Endothelial Cells Derived From Patients With Acute Myocardial Infarction

Endothelial dysfunction is one of the primary factors in the onset and progression of atherothrombosis resulting in acute myocardial infarction (AMI). However, the pathological and cellular mechanisms of endothelial dysfunction in AMI have not been systematically studied. Protein expression profiling in combination with a protein network analysis was used by the mass spectrometry-based label-free quantification approach. This identified and quantified 2246 proteins, of which 335 were differentially regulated in coronary arterial endothelial cells from patients with AMI compared with controls. The differentially regulated protein profiles reveal the alteration of (1) metabolism of RNA, (2) platelet activation, signaling, and aggregation, (3) neutrophil degranulation, (4) metabolism of amino acids and derivatives, (5) cellular responses to stress, and (6) response to elevated platelet cytosolic Ca²⁺ pathways. Increased production of oxidants and decreased production of antioxidant biomarkers as well as downregulation of proteins with antioxidant properties suggests a role for oxidative stress in mediating endothelial dysfunction during AMI. In conclusion, this is the first quantitative proteomics study to evaluate the cellular mechanisms of endothelial dysfunction in patients with AMI. A better understanding of the endothelial proteome and pathophysiology of AMI may lead to the identification of new drug targets.

Ardisia crispa root hexane fraction suppressed angiogenesis in human umbilical vein endothelial cells (HUVECs) and in vivo zebrafish embryo model

Ardisia crispa Thunb. A. DC. (Primulaceae) has been used extensively as folk-lore medicine in South East Asia including China and Japan to treat various inflammatory related diseases. Ardisia crispa root hexane fraction (ACRH) has been thoroughly studied by our group and it has been shown to exhibit anti-inflammatory, anti-hyperalgesic, anti-arthritic, anti-ulcer, chemoprevention and suppression against inflammation-induced angiogenesis in various animal model. Nevertheless, its effect against human endothelial cells in vitro has not been reported yet. Hence, the aim of the study is to investigate the potential antiangiogenic property of ACRH in human umbilical vein endothelial cells (HUVECs) and zebrafish embryo model. ACRH was separated from the crude ethanolic extract of the plant's root in prior to experimental studies. MTT assay revealed that ACRH exerted a concentration-dependent antiproliferative effect on HUVEC with the IC₅₀ of 2.49 ± 0.04 μg/mL. At higher concentration (10 μg/mL), apoptosis was induced without affecting the cell cycle distribution. Angiogenic properties including migration, invasion and differentiation of HUVECs, evaluated via wound healing, trans-well invasion and tube formation assay respectively, were significantly suppressed by ACRH in a concentration-dependent manner. Noteworthily, significant antiangiogenic effects were observed even at the lowest concentration used (0.1 μg/mL). Expression of proMMP-2, vascular endothelial growth factor (VEGF)-C, VEGF-D, Angiopoietin-2, fibroblast growth factor (FGF)-1, FGF-2, Follistatin, and hepatocyte growth factor (HGF) were significantly reduced in various degrees by ACRH. The ISV formation in zebrafish embryo was significantly suppressed by ACRH at the concentration of 5 μg/mL. These findings revealed the potential of ACRH as antiangiogenic agent by suppressing multiple proangiogenic proteins. Thus, it can be further verified via the transcription of these proteins from their respective DNA, in elucidating their exact pathways.

Antitumor Effects and Related Mechanisms of Ethyl Acetate Extracts of Polygonum perfoliatum L

Polygonum perfoliatum L. belongs to the genus Polygonaceae and has a long history to be used as a Chinese medicinal herb to reduce swelling, control body temperature, and promote detoxification. However, its anticancer activity and mechanisms of action have not been evaluated yet. In the present study, we used several cell lines and xenograft models from different cancers to demonstrate the broad-spectrum anticancer activity of P. perfoliatum L as well as its underlying mechanisms of action in vitro and in vivo. The ethyl acetate extract of P. perfoliatum L showed good anticancer activity and was further fractioned to obtain five active components, including PEA to PEE. Among these fractions, PEC showed the strongest cytotoxicities against various cancer cell lines. It was further observed that PEC inhibited cancer cell growth, arrested cells at G2 phase, and induced apoptosis in vitro and suppressed tumor growth and angiogenesis in vivo in a dose- and time-dependent manner. Furthermore, PEC decreased the expression of vascular endothelial growth factor (VEGF) and micro-vascular density (MVD) in tumor tissues in vivo. It also promoted the proliferation of T and B lymphocytes, increased the activities of natural killer (NK) cells and cytotoxic T lymphocytes (CTLs), enhanced the secretion of interleukin 2 (IL-2) by spleen cells, and raised the levels of IgG, IgG2a, and IgG2b antibodies in tumor-bearing mice in vivo, which were at least partially responsible for the anticancer activity of PEC. In summary, PEC has shown broad-spectrum anticancer activities without causing any host toxicity in vitro and in vivo and may be developed as a preventive and therapeutic agent against human cancer. Further studies are urgently needed to determine the anticancer compounds in PEC and their detailed molecular mechanisms.

CircACC1 Regulates Assembly and Activation of AMPK Complex under Metabolic Stress

We report that circACC1, a circular RNA derived from human ACC1, plays a critical role in cellular responses to metabolic stress. CircACC1 is preferentially produced over ACC1 in response to serum deprivation by the transcription factor c-Jun. It functions to stabilize and promote the enzymatic activity of the AMPK holoenzyme by forming a ternary complex with the regulatory β and γ subunits. The cellular levels of circACC1 modulate both fatty acid β-oxidation and glycolysis, resulting in profound changes in cellular lipid storage. In a tumor xenograft model, silencing or enforced expression of circACC1 resulted in growth inhibition and enhancement, respectively. Moreover, increased AMPK activation in colorectal cancer tissues was frequently associated with elevated circACC1 expression. We conclude that circACC1 serves as an economic means to elicit AMPK activation and moreover propose that cancer cells exploit circACC1 during metabolic reprogramming.

Alpinoid c analog inhibits angiogenesis and induces apoptosis in COLO205 cell line

Diarylheptanoids display an array of biological and pharmacological properties. We previously reported the synthesis of a diarylheptanoid Alpinoid c and a series of its derivatives, evaluated their cytotoxicity against various human cancer cells. We found some of these derivatives were significantly more potent than Alpinoid c in preventing the proliferation of various cancer cell lines. Among these, (S, E)-1-(3, 4 dimethoxyphenyl)-6-hydroxy-7-phenylhept-4-en-3-one (DPHP) showed most potent cytotoxicity against COLO205 cells, however, the mechanism by which DPHP prevents the growth of these colon cancer cells remains unknown. In the current study, we investigated the molecular mechanism of DPHP on colon cancer cells. DPHP inhibited the proliferation of COLO205 (IC₅₀ 7.01 ± 0.62 μM) and A549 (IC₅₀ 20.03 ± 3.11 μM) cells more specifically than normal human colon epithelial cell line NCM460 (IC₅₀ 55.6 ± 4.02 μM). In COLO205 cells, DPHP induced cell shrinkage, membrane blebbing, chromatin condensation, phosphatidylserine externalization, and an accumulation of cells at sub-G1 phase. Further analysis these cells treated with DPHP revealed a decrease in mitochondrial membrane potential, an increase in Bax/Bcl2 ratio, the release of cytochrome c, activation of caspases -9, -3/7, and cleavage of the poly-ADP-ribose polymerase. DPHP treatment resulted in inhibition of hypoxia induced VEGF downstream signaling pathway in COLO205 cells is concurrent with inhibition of angiogenesis in CAM. Based on these data we suggest that DPHP significantly induced apoptosis possibly via intrinsic mitochondrial apoptosis pathway and inhibited angiogenesis. Our study suggests DPHP could be a therapeutic agent in treating colon cancer.

Mineralocorticoid receptor negatively regulates angiogenesis through repression of STAT3 activity in endothelial cells

The mineralocorticoid receptor (MR) plays important roles in cardiovascular pathogenesis. The function of MR in angiogenesis is still controversial. This study aimed to explore the role of endothelial MR in angiogenesis and to delineate the underlying mechanism. Endothelial-hematopoietic MR knockout (EMRKO) mice were generated and subjected to hindlimb ischemia and injection of melanoma cells. Laser Doppler measurements showed that EMRKO mice had improved blood flow recovery and increased vessel density in ischemic limbs. In addition, EMRKO accelerated growth and increased the vessel density of tumors. Matrigel implantation, aortic ring assays, and tube formation assays demonstrated that MRKO endothelial cells (ECs) manifested increased angiogenic potential. MRKO ECs also displayed increased migration ability and proliferation. MRKO and MR knockdown both upregulated gene expression, protein level, and phosphorylation of signal transducer and activator of transcription 3 (STAT3). Stattic, a selective STAT3 inhibitor, attenuated the effects of MRKO on tube formation, migration, and proliferation of ECs. At the molecular level, MR interacted with CCAAT enhancer-binding protein beta (C/EBPβ) to suppress the transcription of STAT3. Furthermore, interactions between MR and STAT3 blocked the phosphorylation of STAT3. Finally, stattic abolished the pro-angiogenic phenotype of EMRKO mice. Taken together, endothelial MR is a negative regulator of angiogenesis, likely in a ligand-independent manner. Mechanistically, MR downregulates STAT3 that mediates the impacts of MR deficiency on the angiogenic activity of ECs and angiogenesis. Targeting endothelial MR may be a potential pro-angiogenic strategy for ischemic diseases. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Microcystin-LR induces angiodysplasia and vascular dysfunction through promoting cell apoptosis by the mitochondrial signaling pathway

The harmful algal blooms are becoming increasingly problematic in the regions that drinking water production depends on surface waters. With a global occurrence, microcystins are toxic peptides produced by multiple cyanobacterial genera in the harmful algal blooms. In this study, we examined the effects of microcystin-LR (MC-LR), a representative toxin of the microcystin family, on vascular development in zebrafish and the apoptosis of human umbilical vein endothelial cells (HUVECs). In zebrafish larvae, MC-LR induced angiodysplasia, damaged vascular structures and reduced lumen size at 0.1 μM and 1 μM, leading to the decrease of the blood flow area in the blood vessels and brain hemorrhage, which showed that MC-LR could dose-dependently inhibit vascular development and cause vascular dysfunction. In MC-LR treated HUVECs, the proportion of early apoptosis and late apoptosis cells increased in a concentration-dependent manner. Different concentrations of MC-LR could also activate caspase 3/9 in HUVECs, increase the level of mitochondrial ROS and reduce mitochondrial membrane potential. Additionally, MC-LR could promote the expression of p53 and inhibit the expression of PCNA. The findings showed that MC-LR could promote apoptosis of HUVECs through the mitochondrial signaling pathway. Combined with these results, MC-LR may promote vascular endothelial cell apoptosis through mitochondrial signaling pathway, leading to angiodysplasia and vascular dysfunction.

Effect of Disulfide Bond Incorporation on the Structure and Activity of Endostatin Peptide

The structure and function of a 27-a.a. fragment of the N-terminal sequence of human endostatin (ES-Zn) were compared to those of the mutant peptide (ES-SSZn) obtained by adding Cys-Pro-Ala to the endostatin N-terminus and substituting Asn16 for Cys ensuring formation of a disulfide bond. Structural comparison of ES-Zn and ES-SSZn by far-UV circular dichroism (CD), intrinsic fluorescence, and molecular dynamics simulation methods revealed significant structural perturbations in ES-SSZn, such as elimination of the β-sheet conformer, modification of the N-terminal loop structure, and reorganization of dynamic properties of the entire peptide backbone. ES-SSZn was approximately 2 and 3 times less efficient than ES-Zn and the full-length human endostatin, respectively, in the induction of caspase-3-dependent apoptosis in human umbilical vein endothelial cells (HUVECs) in vitro (p < 0.05). In contrast, treatment of metastatic 4T1 breast tumors in mice with ES-Zn and ES-SSZn (5 mg/kg body weight daily) for 14 days resulted in similar regression of tumor size, comparable downregulation of angiogenesis (CD31 and CD34) and cell proliferation (Ki67), and therefore, the same extent of apoptosis induction (TUNEL, p53, and Bcl-2) for both peptides (as compared to the untreated controls). Western blot analysis of HUVEC and 4T1 tumor lysates revealed the same levels of suppression of key signaling mediators Akt and ERK1/2 by ES-Zn and ES-SSZn. Contrary to the earlier studies, our results showed that the function of the 1-27 endostatin fragment is independent of its overall structure. Stabilization of the N-terminal loop structure by the disulfide bond incorporation causes relief from structural deviations.

Tailor-made PL-UC-C3 nanoparticles for fluorescence/computed tomography imaging-guided cascade amplified photothermal therapy

BACKGROUND

Development of the burgeoning number of photothermal therapy (PTT) agents has drawn a huge amount of interest, since PTT treatment is a powerful and effective alternative to traditional treatments. Optimal PTT agents should integrate some essential preconditions including negligible systemic toxicity, deep penetration into tumor tissues, and maximum laser energy absorbance. Unfortunately, only few of the PTT agents reported could meet all of the above mentioned conditions.

METHODS

Here, we report a brand new PTT agent through the encapsulation of NaGdF4:Yb,Tm@ NaGdF4:Yb (UCNPs) and an organic compound (C3) into poly-e-caprolactone-polyethylene-polyglycol (PCL-PEG) (PL-UC-C3 NPs).

RESULTS

UCNPs as an up-conversion material and C3 as a PTT agent both feature low cytotoxicity, and most importantly, UCNPs with superior conversion efficiency could efficiently absorb the energy of a 980 nm laser, transform the near-infrared laser light into visible light, and translate the palingenetic visible light to C3. The usage of a 980 nm laser ensures a deeper penetration and lower energy, while the highly efficient absorption and transformation process confers a cascade amplified hyperthermia for tumor treatment.

CONCLUSION

In this regard, our research provides a powerful and robust breakthrough for florescence/computed tomography imaging-guided PTT treatment, lighting up the clinical application in cancer treatment.

Directing fibroblast self-assembly to fabricate highly-aligned, collagen-rich matrices

Extracellular matrix composition and organization play a crucial role in numerous biological processes ranging from cell migration, differentiation, survival and metastasis. Consequently, there have been significant efforts towards the development of biomaterials and in vitro models that recapitulate the complexity of native tissue architecture. Here, we demonstrate an approach to fabricating highly aligned cell-derived tissue constructs via the self-assembly of human dermal fibroblasts. By optimizing mold geometry, cell seeding density, and media composition we can direct human dermal fibroblasts to adhere to one another around a non-adhesive agarose peg to facilitate the development of cell-mediated circumferential tension. By removing serum and adding ascorbic acid and l-proline, we tempered fibroblast contractility to enable the formation of stable tissue constructs. Similarly, we show that the alignment of cells and the ECM they synthesize can be modulated by changes to seeding density and that constructs seeded with the lowest number of cells have the highest degree of fibrillar collagen alignment. Finally, we show that this highly aligned, tissue engineered construct can be decellularized and that when re-seeded with fibroblasts, it provides instructive cues which enable cells to adhere to and align in the direction of the remaining collagen fiber network. STATEMENT OF SIGNIFICANCE: Cell and extracellular matrix organization is directly related to biological function including cell signaling and tissue mechanics. Changes to this organization are often associated with injury or disease. The majority of in vitro tissue engineering models investigating cell and matrix organization rely on the addition of stress-shielding exogenous proteins and polymers and, or the application of external forces to promote alignment. Here we present a completely cell-based approach that relies on the development of cell-mediated tension to direct anisotropic cellular alignment and matrix synthesis using human dermal fibroblasts. A major challenge with this approach is excessive cellular contractility that results in necking and failure of the tissue construct. While other groups have tried to overcome this challenge by simply adding more cells, here we show that matrix alignment is inversely related to cell seeding density. To engineer tissue constructs with the highest degree of alignment, we optimized media components to reduce cellular contractility and promote collagen synthesis such that fibroblast toroids remained stable for at least 28 days in culture. We subsequently showed that these collagen-rich tissue constructs could be decellularized while maintaining their collagen microstructure and that cells adhered to and responded to the decellularized cell-derived matrix by aligning and elongating along the collagen fibers. The complexity of cell-derived matrices has been shown to better recapitulate in vivo tissue architecture and composition. This study provides a straight-forward approach to fabricating instructive cell-derived matrices with a high degree of uniaxial alignment generated purely by cell-mediated tension.

Nitroxide radical-modified CuS nanoparticles for CT/MRI imaging-guided NIR-II laser responsive photothermal cancer therapy

Herein, we reported nitroxide radical-modified CuS nanoparticles (CuS-NO˙ NPs), and they exhibited a typical absorption peak at 1182 nm. Due to such a long wavelength absorbance, CuS-NO˙ NPs exhibited excellent therapeutic outcome and low damage to normal tissues. Besides, we simultaneously achieved CuS-NO˙ NPs for MRI and CT dual-modal imaging, which successfully provided a new strategy for imaging-guided tumor treatment, thus increasing potential clinical applications for cancer treatment.

Tailor-made PEG-DA-CuS nanoparticles enriched in tumor with the aid of retro Diels-Alder reaction triggered by their intrinsic photothermal property

Introduction

In recent years, near-infrared laser-induced photothermal therapy is being considered as a promising approach to kill tumors owing to its noninvasive nature and excellent antitumor efficiency. However, the lack of ideal photothermal agents hinders further development of this technology.

Materials and methods

Aiming at solving this long-standing obstacle, we report here about the polyethylene glycol (PEG)-DA modified copper sulfide (CuS) nanoparticles (NPs) (PEG-DA-CuS NPs), a kind of semiconductor photothermal agents that show excellent photothermal stability and high heat conversion efficiency.

Results and discussion

Owing to the surrounding PEG, the water solubility of CuS NPs was significantly improved when circulating in blood in the body. When the NPs reached the tumors and were irradiated by a 1,064 nm laser (1 W/cm², 10 minutes), the local temperature increased above 90°C, triggering the retro Diels–Alder reaction. After the release of PEG chain, CuS NPs soon formed aggregates and enriched the tumor via the enhanced permeability and retention effect, promoting the efficacy of photothermal therapy.

Conclusion

Therefore, we believe PEG-DA-CuS NPs are able to serve as a kind of cytotoxic and efficient photothermal agent to kill cancer.

Functionalization of Halloysite Nanotubes via Grafting of Dendrimer for Efficient Intracellular Delivery of siRNA

Here, polyamidoamine grafted halloysite nanotubes (PAMAM- g-HNTs) were synthesized for loading of siRNA in order to intracellular delivery of siRNA and treat of breast cancer via gene therapy. The successful grafting of PAMAM on HNTs was confirmed by various analytical methods. The size, zeta potential, and grafting ratio of PAMAM- g-HNTs is ∼206.2 nm, +19.8 mV, and 3.04%, respectively. PAMAM- g-HNTs showed good cytocompatibility toward HUVECs (84.7%) and MCF-7 cells (82.3%) even at high concentration of 100 μg/mL. PAMAM- g-HNTs/siRNA exhibited enhanced cellular uptake efficiency of 94.3% compared with Lipofectamine 2000 (Lipo2000)/siRNA (83.6%). PAMAM- g-HNTs/small interfering RNA-vascular endothelial growth factor (siVEGF) led to 78.0% knockdown of cellular VEGF mRNA and induced 33.6% apoptosis in the MCF-7 cells, which is also much higher than that of Lipo2000/siVEGF. In vivo anti-cancer results demonstrated that PAMAM- g-HNTs/siVEGF treated 4T1-bearing mice showed enhanced anti-cancer efficacy than Lipo2000/siVEGF group. Also, the nanocarrier system showed negligible toxic effects toward the major organs of mice. In vivo fluorescence imaging studies showed that there is a slight decrease in the fluorescence signal of PAMAM- g-HNTs/cy5-siVEGF after 72 h post-injection. Therefore, PAMAM- g-HNTs show promising application as novel nanovectors for siRNA delivery and gene therapy of cancer.

Perfluorooctylbromide nanoparticles for ultrasound imaging and drug delivery

Perfluorooctylbromide nanoparticles (PFOB NPs) are a type of multifunctional nanotechnology that has been studied for various medical applications. Commercial ultrasound contrast agents (UCAs) suffer from the following limitations: short half-lives in vivo, high background signal and restricted distribution in the vascular circulation due to their micrometer dimensions. PFOB NPs are new potential UCAs that persist for long periods in the circulatory system, possess a relatively stable echogenic response without increasing the background signal and exhibit lower acoustic attenuation than commercial UCAs. Furthermore, PFOB NPs may also serve as drug delivery vehicles in which drugs are dissolved in the outer lipid or polymer layer for subsequent delivery to target sites in site-targeted therapy. The use of PFOB NPs as carriers has the potential advantage of selectively delivering payloads to the target site while improving visualization of the site using ultrasound (US) imaging. Unfortunately, the application of PFOB NPs to the field of ultrasonography has been limited because of the low intensity of US reflection. Numerous researchers have realized the potential use of PFOB NPs as UCAs and thus have developed alternative approaches to apply PFOB NPs in ultrasonography. In this article, we review the latest approaches for using PFOB NPs to enhance US imaging in vivo. In addition, this article emphasizes the application of PFOB NPs as promising drug delivery carriers for cancer and atherosclerosis treatments, as PFOB NPs can transport different drug payloads for various applications with good efficacy. We also note the challenges and future study directions for the application of PFOB NPs as both a delivery system for therapeutic agents and a diagnostic agent for ultrasonography.

Biomimetic microfluidic platform for the quantification of transient endothelial monolayer permeability and therapeutic transport under mimicked cancerous conditions

Therapeutic delivery from microvasculature to cancerous sites is influenced by many factors including endothelial permeability, vascular flow rates/pressures, cancer secretion of cytokines and permeabilizing agents, and characteristics of the chosen therapeutics. This work uses bi-layer microfluidics capable of studying dye and therapeutic transport from a simulated vessel to a cancerous region while allowing for direct visualization and quantification of endothelial permeability. 2.5 to 13 times greater dye transport was observed when utilizing small dye sizes (FITC) when compared to larger molecules (FITC-Dextran 4 kDa and FITC-Dextran 70 kDa), respectively. The use of lower flow rates/pressures is shown to improve dye transport by factors ranging from 2.5 to 5 times, which result from increased dye diffusion times within the system. Furthermore, subjecting confluent endothelial monolayers to cancerous cells resulted in increased levels of vascular permeability. Situations of cancer induced increases in vascular permeability are shown to facilitate enhanced dye transport when compared to non-diseased endothelial monolayers. Subsequent introduction of paclitaxel or doxorubicin into the system was shown to kill cancerous cells resulting in the recovery of endothelial confluency overtime. The response of endothelial cells to paclitaxel and doxorubicin is quantified to understand the direct influence of anti-cancer therapeutics on endothelial growth and permeability. Introduction of therapeutics into the system showed the recovery of endothelial confluency and dye transport back to conditions experienced prior to cancer cell introduction after 120 h of continuous treatment. Overall, the system has been utilized to show that therapeutic transport to cancerous sites depends on the size of the chosen therapeutic, the flow rate/pressure established within the vasculature, and the degree of cancer induced endothelial permeability. In addition, treatment of the cancerous region has been demonstrated with anti-cancer therapeutics, which are shown to influence vascular permeability in direct (therapeutics themselves) and indirect (death of cancer cells) manners. Lastly, the system presented in this work is believed to function as a versatile testing platform for future anti-cancer therapeutic testing and development.