β-Carotene Induces Apoptosis in Human Esophageal Squamous Cell Carcinoma Cell Lines via the Cav-1/AKT/NF-κB Signaling Pathway

The role of dietary carotenoids in preventing the development of esophageal squamous cell carcinoma

Background and aims: Experimental studies showed that carotenoids had anti-carcinogenic properties, but epidemiological studies on the association between dietary carotenoids and esophageal squamous cell carcinoma (ESCC) risk were limited, and the findings were inconsistent. This study aimed to investigate the roles of intake of dietary carotenoids in the development of ESCC among a rural Chinese population. Methods: A population-based case-control study was conducted in Southwest China. A total of 915 incident ESCC cases and 925 community-based controls were included. A validated food frequency questionnaire with 76-item was adopted to collect information about dietary consumption. Intake of dietary calories and each carotenoid was calculated according to the China food composition tables. Odds ratios (OR) with 95% confidence intervals (CI) were calculated by a logistic regression model, with adjustments for age, gender, body mass index, family cancer history, cigarette smoking, alcohol drinking, education, marital status, prudent pattern score, and total calories. Results: In comparison to the highest with lowest intake quartiles, intake of total carotenes (OR: 0.70, 95% CI: 0.52-0.96, Ptrend: 0.024), α-carotene (OR: 0.62, 95% CI: 0.46-0.83, Ptrend: 0.014), β-carotene (OR: 0.63, 95% CI: 0.46-0.86, P-trend: 0.005), and the sum of lutein and zeaxanthin (OR: 0.41, 95% CI: 0.29-0.56, Ptrend<0.001) was significantly associated with a decreased risk of ESCC after adjustment for confounders. Conclusions: The results indicated that a higher intake of total carotene, α-carotene, β-carotene, and the sum of lutein and zeaxanthin was associated with a lower risk of ESCC.

Exploring the Phytochemicals and Anti-Cancer Potential of the Members of Fabaceae Family: A Comprehensive Review

Cancer is the second-ranked disease and a cause of death for millions of people around the world despite many kinds of available treatments. Phytochemicals are considered a vital source of cancer-inhibiting drugs and utilize specific mechanisms including carcinogen inactivation, the induction of cell cycle arrest, anti-oxidant stress, apoptosis, and regulation of the immune system. Family Fabaceae is the second most diverse family in the plant kingdom, and species of the family are widely distributed across the world. The species of the Fabaceae family are rich in phytochemicals (flavonoids, lectins, saponins, alkaloids, carotenoids, and phenolic acids), which exhibit a variety of health benefits, especially anti-cancer properties; therefore, exploration of the phytochemicals present in various members of this family is crucial. These phytochemicals of the Fabaceae family have not been explored in a better way yet; therefore, this review is an effort to summarize all the possible information related to the phytochemical status of the Fabaceae family and their anti-cancer properties. Moreover, various research gaps have been identified with directions for future research.

Beta-carotene exerted anti-proliferative and apoptotic effect on malignant mesothelioma cells

High blood levels of β-carotene and increased intake in the diets are inversely proportional to incidence of many cancer types. Antioxidant activity of β-carotene was proposed to be related with its antitumor effect. Despite this plant derivative substance being sought in many cancer types, the effectiveness of β-carotene against malignant mesothelioma remained unclear. Therefore, the present study aims to explore the impact of β-carotene on cell viability, apoptosis, and oxidative stress in mesothelioma cells. Human mesothelioma cell SPC212 were treated with β-carotene (3.125-200 μM) for 24, 48, 72, and 96 h. Cytotoxicity was measured with the MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide). Annexin-V/propidium iodide (PI) and caspase 3/7 biomarkers were used to identify apoptotic cells. Finally, the oxidative stress was evaluated with flow cytometry. The results of the measurements indicated a significant decline in viable mesothelioma cancer cell numbers upon β-carotene treatment in time- and concentration-dependent manner when compared to control cells. Furthermore, β-carotene treatment led to apoptosis induction according to both annexin V/PI and caspase 3/7 assays. Furthermore, β-carotene increased oxidative stress in SPC212 cells. These results show how β-carotene affects proliferative, apoptotic, and oxidative properties in SPC212 malignant pleural mesothelioma cells and provide useful insights into future studies.

The Anti-Cancer Effects of Red-Pigmented Foods: Biomarker Modulation and Mechanisms Underlying Cancer Progression

Cancer is one the most malignant diseases that is a leading cause of death worldwide. Vegetables and fruits contain beneficial nutrients such as vitamins, minerals, folates, dietary fibers, and various natural bioactive compounds. These can prevent the pathological processes of many cancers and reduce cancer related mortality. Specifically, the anti-cancer effect of vegetables and fruits is largely attributable to the natural bioactive compounds present within them. A lot of bioactive compounds have very specific colors with pigments and the action of them in the human body varies by their color. Red-pigmented foods, such as apples, oranges, tomatoes, cherries, grapes, berries, and red wine, have been widely reported to elicit beneficial effects and have been investigated for their anti-tumor, anti-inflammatory, and antioxidative properties, as well as anti-cancer effect. Most of the anti-cancer effects of bioactive compounds in red-pigmented foods arise from the suppression of cancer cell invasion and metastasis, as well as the induction of apoptosis and cell cycle arrest. In this review, we assessed publications from the last 10 years and identified 10 bioactive compounds commonly studied in red-pigmented foods: lycopene, anthocyanin, β-carotene, pectin, betaine, rutin, ursolic acid, kaempferol, quercetin, and myricetin. We focused on the mechanisms and targets underlying the anti-cancer effect of the compounds and provided rationale for further investigation of the compounds to develop more potent anti-cancer treatment methods.

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

Acute inflammation is a key component of the immune system’s response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as α- and β-carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, α- and β-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.

Blood plasma resonance Raman spectroscopy combined with multivariate analysis for esophageal cancer detection

We herein report a novel, reliable and inexpensive method for detecting esophageal cancer using blood plasma resonance Raman spectroscopy combined with multivariate analysis methods. The blood plasma samples were divided into late stage cancer group (n = 164), early stage cancer group (n = 35) and normal group (n = 135) based on clinical pathological diagnosis. Using a specially designed quartz capillary tube as sample holder, we obtained higher quality resonance Raman spectra of blood plasma than existing method. The study demonstrated that the carotenoids levels in blood plasma were reduced in esophageal cancer patients. The area under the receiver operating characteristic curve (and 95% confidence interval) calculated by wavenumber selection and principal component analysis combined with linear discriminant analysis (PC-LDA) algorithm were 0.894 (0.858-0.929), 0.901 (0.841-0.960) and 0.871 (0.799-0.942) for differentiating late cancer from normal, late cancer from early cancer, and early cancer from normal respectively. The contribution from the two carotenoids wavenumber regions of 1155 and 1515 cm^-1 were more than 84.2%. The results show that the plasma carotenoids could be a potential biomarker for screening esophageal cancer using resonance Raman spectroscopy combined with wavenumber selection and PC-LDA algorithms.

Role of caveolin-1 in human organ function and disease: friend or foe?

Caveolin-1 (Cav-1) is a structural protein component of caveolae, which are invaginations of the plasma membrane involved in various cellular processes, including endocytosis, extracellular matrix organization, cholesterol distribution, cell migration, and signaling. Mounting evidence over the last 10-15 years has demonstrated a central role of Cav-1 in many diseases, such as cancer, diabetes, and fibrosis. Cav-1 plays positive and negative roles in various diseases through its different regulation pathways. Here, we review the current knowledge on Cav-1 in different diseases and discuss the role of this protein in human organs and diseases.

Glycyrrhizic Acid Alleviates Lipopolysaccharide (LPS)-Induced Acute Lung Injury by Regulating Angiotensin-Converting Enzyme-2 (ACE2) and Caveolin-1 Signaling Pathway

Acute lung injury (ALI) is mainly caused by severe infection, shock, trauma, and burn, which causes the extensive release of inflammatory factors and other mediators. As a major bioactive constituent of traditional Chinese herb licorice, glycyrrhizic acid (GA) plays an important effect on inflammatory regulation. Nevertheless, the exact mechanism of this effect remains unclear. The present study aims to explore the potential protective effect of GA on LPS-induced ALI. Our results showed that GA significantly attenuated LPS-induced ALI and decreased the production of inflammatory factors, including IL-1β, MCP-1, COX2, HMGB1, and adhesion molecules, such as E-selectin, VCAM-1, and modulated expression of angiotensin-converting enzyme 2 (ACE2). Moreover, treatment of ACE2 inhibitor (MLN-4760) reversed the effects of GA on the secretion of pro-inflammatory factors in ALI. Additionally, GA exerts its protective effect by regulating the ACE2 and caveolin-1/NF-κB signaling pathway. In conclusion, this study showed that GA alleviated LPS-induced ALI by upregulating ACE2 and inhibiting the caveolin-1/NF-κB signaling pathway.

Mechanistic aspects of carotenoid health benefits - where are we now?

Dietary intake and tissue levels of carotenoids have been associated with a reduced risk of several chronic diseases, including cardiovascular diseases, type 2 diabetes, obesity, brain-related diseases and some types of cancer. However, intervention trials with isolated carotenoid supplements have mostly failed to confirm the postulated health benefits. It has thereby been speculated that dosing, matrix and synergistic effects, as well as underlying health and the individual nutritional status plus genetic background do play a role. It appears that our knowledge on carotenoid-mediated health benefits may still be incomplete, as the underlying mechanisms of action are poorly understood in relation to human relevance. Antioxidant mechanisms - direct or via transcription factors such as NRF2 and NF-κB - and activation of nuclear hormone receptor pathways such as of RAR, RXR or also PPARs, via carotenoid metabolites, are the basic principles which we try to connect with carotenoid-transmitted health benefits as exemplified with described common diseases including obesity/diabetes and cancer. Depending on the targeted diseases, single or multiple mechanisms of actions may play a role. In this review and position paper, we try to highlight our present knowledge on carotenoid metabolism and mechanisms translatable into health benefits related to several chronic diseases.

The comparison of pegylated liposomal doxorubicin and beta-carotene effects on JAR and JEG-3 choriocarcinoma human cell culture models

Objective:

The aim was to investigate the effectiveness of pegylated liposomal doxorubicin (PLD), beta-carotene, and a combination of PLD and beta-carotene on JAR and JEG-3 human choriocarcinoma (CC) cell lines for the treatment of CC.

Material and Methods:

JAR and JEG-3 cells were cultured. PLD and beta-carotene trial groups were determined with different doses (for single drug trial; PLD 1, 2, 5 μg/mL and beta-carotene 1, 5, 10 μg/mL, and for combined drug trial; all PLD doses combined with beta-carotene 5 μg/mL). Drugs were administered to cultures simultaneously, and 72 hours later the cells were detached using trypsin-ethylenediamine tetraacetic acid solution. The percentage of apoptotic cells was determined by flow cytometry after annexin V staining. One set of the supernatant was collected before trypsin application to investigate beta-human chorionic gonadotropin (β-hCG) and hyperglycosylated hCG (H-hCG) levels. Statistical analyses of the apoptotic ratios were performed using Shapiro-Wilk, Kruskal-Wallis and Mann-Whitney U tests.

Results:

Apoptosis increased in JAR and JEG-3 cultures after treatment with all doses of PLD (p<0.05). A single application of each beta-carotene dose increased apoptosis in JAR cells (p<0.05) but had no apoptotic effects on JEG-3 cells. In the PLD and beta-carotene combination group, apoptosis increased in both JAR and JEG-3 cells (p<0.05).

Conclusion:

To our knowledge, this is the first investigation of the effectiveness of PLD, beta-carotene, and PLD + beta-carotene combination therapy in two different CC cell lines. PLD is a promising chemotherapeutic drug, and beta-carotene can be used as a novel non-chemotherapeutic agent for treatment of CC. Based on the results of this study, vitamin A supplementation may have promise as a preventive measure. However, these data need support from animal experiments and clinical trials.

Carotenoids in Cancer Apoptosis-The Road from Bench to Bedside and Back

An incidence and mortality of cancer are rapidly growing worldwide, especially due to heterogeneous character of the disease that is associated with irreversible impairment of cellular homeostasis and function. Targeting apoptosis, one of cancer hallmarks, represents a potent cancer treatment strategy. Carotenoids are phytochemicals represented by carotenes, xanthophylls, and derived compounds such as apocarotenoids that demonstrate a broad spectrum of anti-cancer effects involving pro-apoptotic signaling through extrinsic and intrinsic pathways. As demonstrated in preclinical oncology research, the apoptotic modulation is performed at post-genomic levels. Further, carotenoids demonstrate additive/synergistic action in combination with conventional oncostatic agents. In addition, a sensitization of tumor cells to anti-cancer conventional treatment can be achieved by carotenoids. The disadvantage of anti-cancer application of carotenoids is associated with their low solubility and, therefore, poor bioavailability. However, this deficiency can be improved by using nanotechnological approaches, solid dispersions, microemulsions or biofortification that significantly increase the anti-cancer and pro-apoptotic efficacy of carotenoids. Only limited number of studies dealing with apoptotic potential of carotenoids has been published in clinical sphere. Pro-apoptotic effects of carotenoids should be beneficial for individuals at high risk of cancer development. The article considers the utility of carotenoids in the framework of 3P medicine.

MiR-124-3p.1 Sensitizes Ovarian Cancer Cells to Mitochondrial Apoptosis Induced by Carboplatin

Background

Carboplatin is a platinum-based chemotherapeutic drug that is commonly used as a treatment for ovarian cancer. However, high doses and repeated use of carboplatin usually reduce the sensitivity of cancer cells to the drug. There is an urgent need to develop strategies to increase the sensitivity of ovarian cancer cells to carboplatin.

Materials and Methods

Quantitative reverse-transcriptase real-time PCR was used to detect miR-124-3p.1 levels in ovarian cancer tissues and cell lines. Transfection with miR-124-3p.1 and caveolin-1 (CAV1) was used for gain-of-function experiments. Western blot and immunoprecipitation assays were performed to evaluate the expression and function of CAV1, AKT, Bad, and Bcl-xl. Flow cytometry analysis was used to measure the apoptosis rates of SKOV3 and A2780 cells.

Results

Expression levels of miR-124-3p.1 were decreased in ovarian cancer tissues and cell lines. Furthermore, overexpression of miR-124-3p.1 enhanced carboplatin-induced apoptotic cell death of ovarian cancer cell lines. Regarding the mechanism of this effect, we showed that CAV1 was the target of miR-124-3p.1 in ovarian cancer. Overexpression of miR-124-3p.1 suppressed the expression of CAV1, thereby reducing the activation of AKT and phosphorylation of Bad. As a result, the function of Bcl-xl was inhibited and carboplatin-induced mitochondrial apoptosis was enhanced.

Conclusion

miR-124-3p.1 sensitizes carboplatin-induced mitochondrial apoptosis through suppression of CAV1 in ovarian cancer. Increasing miR-124-3p.1 expression may represent a novel strategy to improve carboplatin sensitivity in ovarian cancer.

Metformin Inhibits Propofol-Induced Apoptosis of Mouse Hippocampal Neurons HT-22 Through Downregulating Cav-1

Objective

To elucidate the neuroprotective function of metformin in suppressing propofol-induced apoptosis of HT-22 cells.

Methods

HT-22 cells were treated with 0, 10 or 100 μmol/L propofol, followed by determination of their proliferative ability. Subsequently, changes in proliferation and apoptosis of propofol-treated HT-22 cells induced with metformin were assessed. Apoptosis-associated genes in HT-22 cells were detected by Western blot. At last, regulatory effects of Cav-1 on propofol and metformin-treated HT-22 cells were examined.

Results

Propofol treatment dose-dependently decreased proliferative ability and increased apoptosis ability in HT-22 cells, which were partially blocked by metformin administration. Upregulated Bcl-2 and downregulated Bax were observed in propofol-treated HT-22 cells following metformin administration. In addition, Cav-1 level in HT-22 cells was regulated by metformin treatment. Notably, metformin reversed propofol-induced apoptosis stimulation and proliferation decline in HT-22 cells via downregulating Cav-1.

Conclusion

In our study, we found that propofol could induce apoptosis of HT-22 cells and metformin could rescue the apoptosis effect regulated by propofol. Then, we found that metformin protects propofol-induced neuronal apoptosis via downregulating Cav-1.

Caveolin-1 and MLRs: A potential target for neuronal growth and neuroplasticity after ischemic stroke

Ischemic stroke is a leading cause of morbidity and mortality worldwide. Thrombolytic therapy, the only established treatment to reduce the neurological deficits caused by ischemic stroke, is limited by time window and potential complications. Therefore, it is necessary to develop new therapeutic strategies to improve neuronal growth and neurological function following ischemic stroke. Membrane lipid rafts (MLRs) are crucial structures for neuron survival and growth signaling pathways. Caveolin-1 (Cav-1), the main scaffold protein present in MLRs, targets many neural growth proteins and promotes growth of neurons and dendrites. Targeting Cav-1 may be a promising therapeutic strategy to enhance neuroplasticity after cerebral ischemia. This review addresses the role of Cav-1 and MLRs in neuronal growth after ischemic stroke, with an emphasis on the mechanisms by which Cav-1/MLRs modulate neuroplasticity via related receptors, signaling pathways, and gene expression. We further discuss how Cav-1/MLRs may be exploited as a potential therapeutic target to restore neuroplasticity after ischemic stroke. Finally, several representative pharmacological agents known to enhance neuroplasticity are discussed in this review.

Marked Inhibition of Cellular Proliferation in the Normal Human Esophageal Epithelial Cells and Human Esophageal Squamous Cancer Cells in Culture by Carotenoids: Role for Prevention and Early Treatment of Esophageal Cancer

Background:

Globally Esophageal cancer is a common cancer arising from human esophageal mucosal tissue. Epidemiological studies suggest inverse correlation between carotenoid intake and incident risk of this devastating malignancy.

Methods:

In an effort to examine the modulatory role of carotenoids in human esophageal carcinogenesis at a cellular level, we examined the effects of α-carotene and β-carotenes, on cell proliferation and DNA synthesis in human esophageal epithelial (HEE) cells and human esophageal squamous cancer (HESC) cells in in-vitro cultures. HEE and HESC cells were incubated with different concentrations of α- and β-carotenes both individually and in combination.

Results:

Both Carotenes significantly inhibited (p<0.05) cellular proliferation and decreased DNA synthesis in HEE and HESC cells. The effect of α- and β-carotene together on DNA synthesis in HEE and HESC cells was significantly greater than either carotenoid alone, suggesting a synergistic effect. Greater magnitude of cellular inhibition of DNA synthesis was observed on HEE cells than HESC cells.

Conclusion:

Our results suggest that a combination of α-and β-carotene may provide a novel strategy for prevention and treatment of esophageal and upper aero digestive tract cancer in humans.

β-carotene suppresses Porphyromonas gingivalis lipopolysaccharide-mediated cytokine production in THP-1 monocytes cultured with high glucose condition

Periodontitis is associated with development of diabetes mellitus. Although lipopolysaccharide (LPS) of Porphyromonas gingivalis (Pg), a major pathogen of periodontitis, may lead the progression of diabetes complications, the precise mechanisms are unclear. We, therefore, investigated the effects of β-carotene on production of Pg LPS-induced inflammatory cytokines in human monocytes cultured high glucose (HG) condition. THP-1 cells were cultured under 5.5 mM or 25 mM glucose conditions, and cells were stimulated with Pg LPS. To investigate the productivity of TNF-α, IL-6, and MCP-1, cell supernatants were collected for ELISA. To examine the effects of NF-kB signals on cytokine production, Bay11-7082 was used. HG enhanced Pg LPS-induced production of TNF-α, IL-6, and MCP-1 via NF-kB signals in THP-1. β-carotene suppressed the enhancement of the Pg LPS-induced cytokine production in THP-1 via NF-κB inactivation. Our results suggest that β-carotene might be a potential anti-inflammatory nutrient for circulating Pg LPS-mediated cytokine production in diabetic patients with periodontitis.

The different functions and clinical significances of caveolin-1 in human adenocarcinoma and squamous cell carcinoma

Caveolin-1 (Cav-1), a major structural protein of caveolae, is an integral membrane protein which plays an important role in the progression of carcinoma. However, whether Cav-1 acts as a tumor promoter or a tumor suppressor still remains controversial. For example, the tumor-promoting function of Cav-1 has been found in renal cancer, prostate cancer, tongue squamous cell carcinoma (SCC), lung SCC and bladder SCC. In contrast, Cav-1 also plays an inhibitory role in esophagus adenocarcinoma, lung adenocarcinoma and cutaneous SCC. The role of Cav-1 is still controversial in thyroid cancer, hepatocellular carcinoma, gastric adenocarcinoma, colon adenocarcinoma, breast cancer, pancreas cancer, oral SCC, laryngeal SCC, head and neck SCC, esophageal SCC and cervical SCC. Besides, it has been reported that the loss of stromal Cav-1 might predict poor prognosis in breast cancer, gastric cancer, pancreas cancer, prostate cancer, oral SCC and esophageal SCC. However, the accumulation of stromal Cav-1 has been found to be promoted by the progression of tongue SCC. Taken together, Cav-1 seems playing a different role in different cancer subtypes even of the same organ, as well as acting differently in the same cancer subtype of different organs. Thus, we hereby explore the functions of Cav-1 in human adenocarcinoma and SCC from the perspective of clinical significances and pathogenesis. We envision that novel targets may come with the further investigation of Cav-1 in carcinogenesis.

Binding studies and biological evaluation of β-carotene as a potential inhibitor of human calcium/calmodulin-dependent protein kinase IV

Human calcium/calmodulin-dependent protein kinase IV (CAMKIV), a member of Ser/Thr kinase family, is associated with cancer, cerebral hypoxia and neurodegenerative diseases. β-carotene is a colored organic compound, abundant in plants and fruits and is used in cancer prevention. Here, we report a strong binding affinity of β-carotene with CAMKIV using molecular docking, fluorescence binding and isothermal titration calorimetry methods. Furthermore, β-carotene also reduces the enzyme activity of CAMKIV moderately as observed during ATPase assay. To see the role of β-carotene on cell proliferation and apoptosis, cancerous cells (HeLa, HuH7and MCF-7) and normal (HEK-293-T) cell lines were used. Admirable anticancer activity of β-carotene was observed. We further performed propidium iodide and DAPI (4',6-diamidino-2-phenylindole) assays to understand the mechanism of anticancer activity of β-carotene at molecular level. Our findings provide a newer insight into the use of β-carotene in cancer prevention and protection via inhibition of CAMKIV by regulating the signaling pathways.

β-Carotene synergistically enhances the anti-tumor effect of 5-fluorouracil on esophageal squamous cell carcinoma in vivo and in vitro

Recently, we reported that β-carotene exhibited anticancer activity against human esophageal squamous cell carcinoma cells in vitro. In the present study, we examined a novel therapeutic strategy by combining β-carotene with 5-fluorouracil (5-FU) in human esophageal cancer in vitro and in vivo, and elucidated the underlying mechanisms. We found that the combination of 5-FU and β-carotene displayed greater growth inhibitory effects than did either compound alone in esophageal squamous cell carcinoma (ESCC) cells. In addition, the combination of 5-FU and β-carotene displayed greater tumor growth inhibition in an Eca109 xenograft mouse model than did a single agent with low systemic toxicity. β-Carotene enhanced 5-FU-induced apoptosis. TUNEL staining revealed that the rate of TUNEL-positive cells was markedly increased in tumor tissues after treatment with 5-FU and β-carotene. Western blotting and immunohistochemistry revealed the down-regulation of Bcl-2 and PCNA and the up-regulation of Bax and caspase-3 in tumor tissues. Further studies demonstrated that the combined administration of 5-FU and β-carotene significantly down-regulated the protein levels of Cav-1, p-AKT, p-NF-κB, p-mTOR and p-p70S6K in Eca109 cells more effectively than did 5-FU alone. These data suggested that the combined therapy of 5-FU and β-carotene exerted synergistic antitumor effects in vivo and in vitro and could constitute a novel therapeutic treatment for ESCC.

Resveratrol Exerts Dosage-Dependent Effects on the Self-Renewal and Neural Differentiation of hUC-MSCs

Resveratrol (RES) plays a critical role in the fate of cells and longevity of animals via activation of the sirtuins1 (SIRT1) gene. In the present study, we intend to investigate whether RES could promote the self-renewal and neural-lineage differentiation in human umbilical cord derived MSCs (hUC-MSCs) in vitro at concentrations ranging from 0.1 to 10 μM, and whether it exerts the effects by modulating the SIRT1 signaling. Herein, we demonstrated that RES at the concentrations of 0.1, 1 and 2.5 μM could promote cell viability and proliferation, mitigate senescence and induce expression of SIRT1 and Proliferating Cell Nuclear Antigen (PCNA) while inhibit the expression of p53 and p16. However, the effects were reversed by 5 and 10 μM of RES. Furthermore, RES could promote neural differentiation in a dose-dependent manner as evidenced by morphological changes and expression of neural markers (Nestin, βIII-tubulin and NSE), as well as pro-neural transcription factors Neurogenin (Ngn)1, Ngn2 and Mash1. Taken together, RES exerts a dosage-dependent effect on the self-renewal and neural differentiation of hUC-MSCs via SIRT1 signaling. The current study provides a new strategy to regulate the fate of hUC-MSCs and suggests a more favorable in vitro cell culture conditions for hUC-MSCs-based therapies for some intractable neurological disorders.