Heat shock proteins in cancer - Known but always being rediscovered: Their perspectives in cancer immunotherapy.

Heat shock proteins (HSPs) represent cellular chaperones that are classified into several families, including HSP27, HSP40, HSP60, HSP70, and HSP90. The role of HSPs in the cell includes the facilitation of protein folding and maintaining protein structure. Both processes play crucial roles during stress conditions in the cell such as heat shock, degradation, and hypoxia. Moreover, HSPs are important modulators of cellular proliferation and differentiation, and are strongly associated with the molecular orchestration of carcinogenesis. The expression and/or activity of HSPs in cancer cells is generally abnormally high and is associated with increased metastatic potential and activity of cancer stem cells, more pronounced angiogenesis, downregulated apoptosis, and the resistance to anticancer therapy in many patients. Based on the mentioned reasons, HSPs have strong potential as valid diagnostic, prognostic, and therapeutic biomarkers in clinical oncology. In addition, numerous papers describe the role of HSPs as chaperones in the regulation of immune responses inside and outside the cell. Importantly, highly expressed/activated HSPs may be inhibited via immunotherapeutic targets in various types of cancers. The aim of this work is to provide a comprehensive overview of the relationship between HSPs and the tumor cell with the intention of highlighting the potential use of HSPs in personalized cancer management.

Ellagic Acid and Cancer Hallmarks: Insights from Experimental Evidence.

Cancer is a complex and multifaceted disease with a high global incidence and mortality rate. Although cancer therapy has evolved significantly over the years, numerous challenges persist on the path to effectively combating this multifaceted disease. Natural compounds derived from plants, fungi, or marine organisms have garnered considerable attention as potential therapeutic agents in the field of cancer research. Ellagic acid (EA), a natural polyphenolic compound found in various fruits and nuts, has emerged as a potential cancer prevention and treatment agent. This review summarizes the experimental evidence supporting the role of EA in targeting key hallmarks of cancer, including proliferation, angiogenesis, apoptosis evasion, immune evasion, inflammation, genomic instability, and more. We discuss the molecular mechanisms by which EA modulates signaling pathways and molecular targets involved in these cancer hallmarks, based on in vitro and in vivo studies. The multifaceted actions of EA make it a promising candidate for cancer prevention and therapy. Understanding its impact on cancer biology can pave the way for developing novel strategies to combat this complex disease.

Anticancer Potential of Natural Chalcones: In Vitro and In Vivo Evidence.

There is no doubt that significant progress has been made in tumor therapy in the past decades. However, the discovery of new molecules with potential antitumor properties still remains one of the most significant challenges in the field of anticancer therapy. Nature, especially plants, is a rich source of phytochemicals with pleiotropic biological activities. Among a plethora of phytochemicals, chalcones, the bioprecursors of flavonoid and isoflavonoids synthesis in higher plants, have attracted attention due to the broad spectrum of biological activities with potential clinical applications. Regarding the antiproliferative and anticancer effects of chalcones, multiple mechanisms of action including cell cycle arrest, induction of different forms of cell death and modulation of various signaling pathways have been documented. This review summarizes current knowledge related to mechanisms of antiproliferative and anticancer effects of natural chalcones in different types of malignancies including breast cancers, cancers of the gastrointestinal tract, lung cancers, renal and bladder cancers, and melanoma.

Chalcones and Gastrointestinal Cancers: Experimental Evidence.

Colorectal (CRC) and gastric cancers (GC) are the most common digestive tract cancers with a high incidence rate worldwide. The current treatment including surgery, chemotherapy or radiotherapy has several limitations such as drug toxicity, cancer recurrence or drug resistance and thus it is a great challenge to discover an effective and safe therapy for CRC and GC. In the last decade, numerous phytochemicals and their synthetic analogs have attracted attention due to their anticancer effect and low organ toxicity. Chalcones, plant-derived polyphenols, received marked attention due to their biological activities as well as for relatively easy structural manipulation and synthesis of new chalcone derivatives. In this study, we discuss the mechanisms by which chalcones in both in vitro and in vivo conditions suppress cancer cell proliferation or cancer formation.

Chalcone-Acridine Hybrid Suppresses Melanoma Cell Progression via G2/M Cell Cycle Arrest, DNA Damage, Apoptosis, and Modulation of MAP Kinases Activity.

This study was focused on investigating the antiproliferative effects of chalcone hybrids in melanoma cancer cells. Among seven chalcone hybrids, the chalcone-acridine hybrid 1C was the most potent and was selected for further antiproliferative mechanism studies. This in vitro study revealed the potent antiproliferative effect of 1C via cell cycle arrest and apoptosis induction. Cell cycle arrest at the G2/M phase was associated with modulation of expression or phosphorylation of specific cell cycle-associated proteins (cyclin B1, p21, and ChK1), tubulins, as well as with the activation of the DNA damage response pathway. Chalcone 1C also induced apoptosis accompanied by mitochondrial dysfunction evidenced by a decrease in mitochondrial membrane potential, increase in Bax/Bcl-xL ratio and cytochrome c release followed by caspase 3/7 activation. In addition, increased phosphorylation of MAP kinases (Erk1/2, p38 and JNK) was observed in chalcone 1C-treated melanoma cells. The strong antiproliferative activities of this chalcone-acridine hybrid suggest that it may be useful as an antimelanoma agent in humans.

Programmed Cell Death Alterations Mediated by Synthetic Indole Chalcone Resulted in Cell Cycle Arrest, DNA Damage, Apoptosis and Signaling Pathway Modulations in Breast Cancer Model.

Although new chemotherapy significantly increased the survival of breast cancer (BC) patients, the use of these drugs is often associated with serious toxicity. The discovery of novel anticancer agents for BC therapy is expected. This study was conducted to explore the antiproliferative effect of newly synthesized indole chalcone derivative ZK-CH-11d on human BC cell lines. MTT screening, flow cytometry, Western blot, and fluorescence microscopy were used to evaluate the mode of cell death. ZK-CH-11d significantly suppressed the proliferation of BC cells with minimal effect against non-cancer cells. This effect was associated with cell cycle arrest at the G2/M phase and apoptosis induction. Apoptosis was associated with cytochrome c release, increased activity of caspase 3 and caspase 7, PARP cleavage, reduced mitochondrial membrane potential, and activation of the DNA damage response system. Furthermore, our study demonstrated that ZK-CH-11d increased the AMPK phosphorylation with simultaneous inhibition of the PI3K/Akt/mTOR pathway indicating autophagy initiation. However, chloroquine, an autophagy inhibitor, significantly potentiated the cytotoxic effect of ZK-CH-11d in MDA-MB-231 cells indicating that autophagy is not principally involved in the antiproliferative effect of ZK-CH-11d. Taking together the results from our experiments, we assume that autophagy was activated as a defense mechanism in treated cells trying to escape from chalcone-induced harmful effects.

Molecular Mechanisms of Antiproliferative Effects of Natural Chalcones.

Although great progress has been made in the treatment of cancer, the search for new promising molecules with antitumor activity is still one of the greatest challenges in the fight against cancer due to the increasing number of new cases each year. Chalcones (1,3-diphenyl-2-propen-1-one), the precursors of flavonoid synthesis in higher plants, possess a wide spectrum of biological activities including antimicrobial, anti-inflammatory, antioxidant, and anticancer. A plethora of molecular mechanisms of action have been documented, including induction of apoptosis, autophagy, or other types of cell death, cell cycle changes, and modulation of several signaling pathways associated with cell survival or death. In addition, blockade of several steps of angiogenesis and proteasome inhibition has also been documented. This review summarizes the basic molecular mechanisms related to the antiproliferative effects of chalcones, focusing on research articles from the years January 2015-February 2021.

Jaspine B Hydrochloride-induced Apoptosis in HeLa Cells Is Associated With Disrupted Sphingolipid Metabolism and Ceramide Overload.

BACKGROUND/AIM: A series of experiments on HeLa cells were conducted to provide new information concerning the anti-cancer properties of jaspine B hydrochloride (JBH). MATERIALS AND METHODS: HeLa cells treated with 0.5 µmol/l JBH for 24, 48, and 72 h underwent flow cytometric analysis of the cell cycle, and measurement of phosphatidylserine externalization, mitochondrial membrane potential (MMP), casp-3 activation, cleavage of PARP, ceramide levels, aSMase activity, and Bcl-2 release. nSMase activity was measured by a colorimetric assay. Gene expression was determined by qRT-PCR. Immunocytochemistry was performed to detect p21 and p27 expression. RESULTS: JBH-induced apoptosis in HeLa cells associated with externalization of phosphatidylserine, reduced MMP, activation of casp-3, and cleavage of PARP as well as up-regulation of TNF-α, FasL, and casp-8. Significant increase in nSMase activity, ceramide levels, Bcl-2 release (predominantly in the inactive form), and pro-apoptotic nuclear localization of p21 and p27 were also detected. CONCLUSION: JBH-induced apoptosis in HeLa cells is associated with disrupted sphingolipid homeostasis resulting in increased ceramide levels.

Anti-Cancer Effect of Tacrine-Coumarin Derivatives on Diverse Human and Mouse Cancer Cell Lines.

Acridine derivatives were first used as antibacterial and antiparasitic agents, later as antimalarial and anti-HIV drugs, and now as potentially anti-cancer agents due to their high cytotoxic activity. Due to their serious adverse effects, new synthetic derivatives were introduced and tested based on modified naturally occurring substances, such as acridone derivatives, which also exhibit potential anti-tumor activity. Most of them are DNA-damaging substances, causing relatively strong and selective destruction of tumor cells. We have tested in vitro anti-proliferative effects of newly-synthesized tetrahydroacrid derivatives, namely tacrine-coumarin hybrid molecules, on various human and mouse cancer cell lines. Our results showed that tacrine-coumarin hybrids with seven, eight, and nine methylene groups in spacer reduce proliferation of cancer cells. A hybrid with nine methylene groups had the most significant anti-cancer effect.

Antiangiogenic Effect of Flavonoids and Chalcones: An Update.

Chalcones are precursors of flavonoid biosynthesis in plants. Both flavonoids and chalcones are intensively investigated because of a large spectrum of their biological activities. Among others, anticancer and antiangiogenic effects account for the research interest of these substances. Because of an essential role in cancer growth and metastasis, angiogenesis is considered to be a promising target for cancer treatment. Currently used antiangiogenic agents are either synthetic compounds or monoclonal antibodies. However, there are some limitations of their use including toxicity and high price, making the search for new antiangiogenic compounds very attractive. Nowadays it is well known that several natural compounds may modulate basic steps in angiogenesis. A lot of studies, also from our lab, showed that phytochemicals, including polyphenols, are potent modulators of angiogenesis. This review paper is focused on the antiangiogenic effect of flavonoids and chalcones and discusses possible underlying cellular and molecular mechanisms.

Antiproliferative effect of ß-escin - an in vitro study.

This study examined the antiproliferative effects of ß-escin (E) in cancer cells. The study showed that E inhibited cancer cells growth in a dose-dependent manner. The flow cytometric analysis revealed an escin-induced increase in the sub-G1 DNA content, which is considered to be a marker of apoptosis. Apoptosis was also confirmed by annexin V staining and DNA fragmentation assay. These effects were associated with increased generation of reactive oxygen species (ROS), caspase-3 activation and decreased mitochondrial membrane potential (MMP). Moreover, escin decreased mitochondrial protein content and mitochondrial fluorescence intensity as well as caused depletion of glutathione (GSH). However, activity of glutathione peroxidase (GPx) and glutathione reductase (GR) was not significantly changed in escin-treated cells. In conclusion, our results demonstrated that E has apoptotic effects in human cancer cells through the mechanisms involving mitochondrial perturbation. Although the exact mechanism needs to be investigated further, it can be concluded that E may be a useful candidate agent for cancer treatment.

Soy and breast cancer: focus on angiogenesis.

Epidemiological studies have revealed that high consumption of soy products is associated with low incidences of hormone-dependent cancers, including breast and prostate cancer. Soybeans contain large amounts of isoflavones, such as the genistein and daidzain. Previously, it has been demonstrated that genistein, one of the predominant soy isoflavones, can inhibit several steps involved in carcinogenesis. It is suggested that genistein possesses pleiotropic molecular mechanisms of action including inhibition of tyrosine kinases, DNA topoisomerase II, 5α-reductase, galectin-induced G2/M arrest, protein histidine kinase, and cyclin-dependent kinases, modulation of different signaling pathways associated with the growth of cancer cells (e.g., NF-κB, Akt, MAPK), etc. Moreover, genistein is also a potent inhibitor of angiogenesis. Uncontrolled angiogenesis is considered as a key step in cancer growth, invasion, and metastasis. Genistein was found to inhibit angiogenesis through regulation of multiple pathways, such as regulation of VEGF, MMPs, EGFR expressions and NF-κB, PI3-K/Akt, ERK1/2 signaling pathways, thereby causing strong antiangiogenic effects. This review focuses on the antiangiogenic properties of soy isoflavonoids and examines their possible underlying mechanisms.

MDR1 polymorphisms and idiopathic nephrotic syndrome in Slovak children: preliminary results.

BACKGROUND: The role of the multidrug resistance-1 (MDR1 or ABCB1) gene polymorphisms 1236T>C, 2677T>G, and 3435T>C was studied in relation to susceptibility, demographics, and pathological characteristics, as well as their role in the therapeutic response (TR) to prednisone treatment in children with idiopathic nephrotic syndrome (INS). MATERIAL/METHODS: The polymorphisms were analyzed using the polymerase chain reaction-restriction fragment length polymorphism method in 46 children with INS and in 100 healthy controls. Different genetic models (codominant, dominant, recessive, and overdominant) were used for testing of associations between polymorphisms and phenotypes. RESULTS: Statistical analysis showed a significantly increased chance of TR in children carrying 3435TC genotype (OR=5.13, 95% CI=1.18-22.25; overdominant model). Moreover, INS patients under 6 years of age had significantly decreased frequencies of MDR1 1236CC (7.7% vs. 35%, p=0.029) or 2677GG (3.8% vs. 30.0%, p=0.033) genotypes. We also observed that patients with minimal change in disease and patients under 6 years of age at the onset of INS were initial responders more frequently when compared with children with focal segmental glomerulosclerosis and patients ≥6 years old at the onset (p=0.0001, p=0.027, respectively). CONCLUSIONS: These data suggest that prednisone TR may be influenced by histology, age at the onset of INS, and MDR1 3435T>C polymorphism. The MDR1 1236T>C and 2677T>G polymorphisms were significantly associated with age at onset. Larger multicenter studies and studies across other ethnic groups are needed to elucidate the contradictory implications of MDR1 polymorphisms with INS in children.

MRP1 and GSTp1 expression in non-small cell lung cancer does not correlate with clinicopathological parameters: A Slovakian population study.

We detected MRP1 (multidrug resistance-associated protein 1) and GSTp1 (glutathione-S-transferase p1) protein expression in samples of non-small cell lung cancer (NSCLC) and our results were compared to basic clinicopathological parameters. The indirect immunohistochemical method was used for localization of monitored proteins. A total of 135 tissue samples of NSCLC were characterized according to histopathological type of tumor. Next, we compared our results with basic clinicopathological parameters (histopathological type of tumor, tumor grade and TNM stage of disease). In MRP1 and GSTp1 positive tumor cells, strong brown cytoplasmic immunostaining was visible. In our set of samples 71% showed MRP1 positivity, while according to histopathological type the squamous cell carcinoma reached the highest level of positivity (76%). Our GSTp1 results showed that similarly to MRP1, 70% of samples were GSTp1 positive. According to histopathological type the adenocarcinoma samples showed the highest GSTp1 expression (77%). For precise statistical evaluation the Kruskal-Wallis, Chi-square and Mann-Whitney tests were used. We did not find any statistically significant correlations between MRP1 and clinicopathological parameters. In the group of GSTp1, by Mann-Whitney test we found a statistically significant correlation between GSTp1 and histological grade (p=0.025) in adenocarcinoma samples. As this was only one group of statistically significant correlation we wanted to confirm this finding. For this we applied also Chi-square test which revealed no statistically significant dependence (p=0.077). No statistically significant relation was seen in the coexpression of both proteins (p=0.753). Despite this, the majority of samples simultaneously expressed MRP1 and GSTp1 proteins. In conclusion, our results show that MRP1 and GSTp1 proteins represent independent prognostic features in NSCLC. Nevertheless, the clinical outcome in individual patients is often difficult to predict. Identification of the factors that characterize the resistant cases would permit immediate treatment of the patients with alternative therapeutic approaches.

Brassinin and its derivatives as potential anticancer agents.

The aim of the study was to investigate the anti-proliferative activity of brassinin and its derivatives on human cancer cell lines. We found that among twenty-one tested compounds, 1- methoxybrassinin exerted the most potent anti-proliferative activity in Caco-2 cells with IC50 8.2 (±1.2)µmoll(-1). The flow cytometric analysis revealed a 1-methoxybrassinin-induced increase in the sub-G1 DNA content fraction which is considered to be a marker of apoptotic cell death. Apoptosis was also confirmed by DNA fragmentation assay. Moreover, quantitative real-time PCR showed that 1-methoxybrassinin upregulated the expression of pro-apoptotic Bax and downregulated the expression of anti-apoptotic genes Bcl-2 and Bcl-xL. The compound also increased activity of caspase-3, -7, cleaved PARP and decreased intracellular GSH content. The present study has assessed the in vitro anti-proliferative potential of 1-methoxybrassinin. The results generate a rationale for in vivo efficacy studies with this compound in preclinical cancer models.

In vitro toxicity of camalexin derivatives in human cancer and non-cancer cells.

The aim of the study was to investigate the cytotoxic activity of camalexin and its five synthetic derivatives in cancer and non-cancer cells. In cancer cells the benzocamalexin (BC) displayed the most potent activity with an IC value of 23.3-30.1 µmol/L. On the other hand, minimal toxicity (IC>100.0 µmol/L) in non-cancer cells was observed. Based on these results, BC was selected for further studies. Flow cytometric analysis revealed a BC-induced arrest of the cell cycle in the G2 phase associated with downregulation of α-tubulin, α1-tubulin, ß5-tubulin expression. These findings suggest that the inhibitory effect of BC is mediated via inhibition of microtubule formation. Moreover, BC downregulated the expression of microtubule-related protein indicating the effect of this compound on microtubule assembly. After treatment with BC increase of the sub-G DNA content fraction was noted which is considered to be a marker of apoptotic cell death. Apoptosis was also confirmed by DNA fragmentation assay. Moreover, quantitative real-time PCR showed that BC downregulated the expression of antiapoptotic genes Bcl-2 and Bcl-xL and upregulated the expression of proapoptotic Bax. Taken together, our study suggests that the blockade of cell cycle progression and initiation of apoptosis may play an important role in the antiproliferative activity of BC in human cancer cells.

Association between polymorphisms of XRCC1, p53 and MDR1 genes, the expression of their protein products and prognostic significance in human breast cancer.

BACKGROUND: This study aimed to examine the relationship between XRCC1, p53 and MDR1 protein, along with polymorphisms of their genes and their prognostic values in breast cancer. The following clinical and pathological parameters were evaluated: histopathological type of tumor, grade, stage, Her2/neu expression, ER, PR positivity and involvement of regional lymph nodes. MATERIAL/METHODS: Expression of proteins was determined in 39 samples of breast cancer by immunohistochemistry. Nucleotide polymorphisms were analyzed by PCR-RFLP. For statistical analysis, chi-square test (Yates), Fisher's exact test, and correlation test were used to analyze the data. RESULTS: The highest protein expression was immunohistochemically found in MDR1 protein, with 54% of samples testing positive. In addition, the evaluation of MDR1 expression revealed higher positive immunoreactivity in lobular (LIC) and other types of tumor in comparison to ductal (DIC) type. The expression of p53 and XRCC1 protein was equal, but lower compared to MDR1, both testing positive in 36% of all tissue samples. Comparison of XRCC1 protein and histopathological type of tumor revealed that DIC and LIC types were mostly XRCC1-negative, while other types, papillary and mucinous were more likely to be XRCC1-positive. Interestingly, when evaluating LIC samples separately, a negative correlation between the Her2/neu and expression of XRCC1 was detected. Apparently, all Her2/neu-positive samples were XRCC1-negative (6/86%). The correlation test indicated a negative correlation between Her2/neu-positive samples and XRCC1-negative specimens (r = 1, p < 0.05). Statistical analysis did not reveal a correlation of p53 expression with clinical and pathological parameters. Similarly, no statistically significant difference was found between the tested polymorphisms and protein expression. CONCLUSIONS: We did not find statistically significant correlation between tested polymorphisms and their protein expression.

Prognostic significance of p53 protein and X-ray repair cross-complementing protein 1 in non-small cell lung cancer.

OBJECTIVES: p53 and XRCC1 protein expression were evaluated in 54 samples of nonsmall cell lung cancer. PATIENTS AND METHODS: The immunohistochemical method was used for detection of the monitored proteins. Tissue samples were divided according to histopathological tumor type. The results were then compared with basic clinical and histopathological parameters (histopathological type, nuclear grade and TNM tumor stage IA, IB). RESULTS: Statistically significant correlations were found between histopathological type and p53 expression, since P < 0.05 (P = 0.015). Comparing p53 expression with grade resulted in a strong positive correlation (P < 0.0396, R2 = 0.9223). The percentage of p53-positive tumors progressively increased from 0% in grade 1 to 75% in grade 4. No correlation was found between p53 expression and tumor stage. In case of XRCC1, the highest level was found in squamous cell lung carcinoma, where 71% of samples was positive. In case of large cell carcinoma samples, it was 67%, and in adenocarcinoma 52% of samples showed XRCC1 immunoreactivity. No statistically significant correlation was found between histopathological type, grade or early stage (IA, IB) of non-small cell lung cancer and expression of XRCC1 protein profile without neoadjuvant therapy. CONCLUSIONS: We found a statistically significant correlation between p53 expression and histopathological tumor type. It is possible that stabilized p53 protein plays an important role in the development of squamous and large cell carcinoma. Our findings also suggest that p53 expression cumulates with the dedifferentiation of cancer cells. It is possible that the expression of XRCC1 is not fixed and could be changed by the status of cancer cells and in relation to therapy. Relevant data about pre- versus post-chemotherapy and XRCC1 expression are needed to evaluate the influence of XRCC1 on drug resistance.

Effect of selected flavones on cancer and endothelial cells.

In our study we used quercetin (3,3 ,4 ,5,7-pentahydroxyflavone) as the reference standard to compare antiproliferative and antiangiogenic effects of chrysin (5,7-dihydroxyflavone) and 3-hydroxyflavone. Our data indicates that chrysin and 3-hydroxyflavone showed significantly higher cytotoxic effect than reference standard quercetin. These tested agents significantly decreased cell survival with the efficacy of 65-85% at the concentration 100 micromol/l for HUVEC, lung carcinoma and leukemic cells being the most sensitive. Cell cycle analysis indicates that quercetin and 3-hydroxyflavone might affect the cell cycle of Jurkat cells by a similar or the same mechanism of action which lead to G2/M arrest as well as to an increase in sub-G0/G1 fraction. Treatment of Jurkat cells with chrysin resulted only increase in the fraction of cells with sub-G0/G1 DNA content, which is considered to be a marker of apoptotic cell death. Apoptosis was confirmed by DNA fragmentation and by staining with annexin V. All three tested flavones inhibited endothelial cell migration after 24 h of incubation at a concentration 100 micromol/l. At a lower concentration (10 micromol/l) only quercetin significantly inhibited migration of endothelial cells. Furthermore, in our experiments decreased secretion of matrix metalloproteinases (MMP-2 and MMP-9) was observed after a 72 h treatment with quercetin. No decrease in secretion of MMP-2 and MMP-9 was seen after chrysin and 3-hydroxyflavone treatment. On the other hand, our results showed that none of three flavonoids blocked microcapillary tube formation. Further studies are necessary to investigate the mechanism of action and to find out the relationship between the structure, character and position of substituents of natural substances and their biological activities.

In vitro antiproliferative and antiangiogenic effects of synthetic chalcone analogues.

As flavonoids, chalcones possess a wide variety of biological activities including anticancer properties. In the present study we have investigated the in vitro antiproliferative and antiangiogenic effects of four synthetic chalcones. E-2-(4'-methoxybenzylidene)-1-benzosuberone (3) was the most active compound with IC(50)=10(-7)mol l(-1) in Jurkat cells. In both Jurkat and HeLa chalcone 3-treated cells we found a significant increase in the proportion of cancer cells in the G(2)/M phase of the cell cycle as well as an increase in cells having sub-G(0)/G(1) DNA content which is considered to be a marker of apoptotic cell death. Apoptosis was also confirmed by annexin V staining and DNA fragmentation. These effects were associated with reduced expression of the anti-apoptotic gene, Bcl-2, and increased expression of the pro-apoptotic gene, Bax. Furthermore, chalcone 3 was selected to evaluate its effect on some angiogenic events. In non-toxic concentrations, chalcone 3 inhibited VEGF-induced migration of human umbilical vein endothelial cells. Moreover, it also decreased secretion of matrix metalloproteinase (mainly MMP-9) and vascular endothelial growth factor (VEGF). In conclusion, the present study has assessed the in vitro antiproliferative/antiangiogenic potential of chalcone 3. This results generate a rationale for in vivo efficacy studies with this compound in preclinical cancer models.