Molecular effects of genistein, as a potential anticancer agent, on CXCR-4 and VEGF pathway in acute lymphoblastic leukemia

BACKGROUND

Vascular endothelial growth factor (VEGF) is one of the angiogenic mediators that can be secreted by leukemic cells and plays an important role in tumor invasion and metastasis. Another important agent contributing to the relapse of ALL is C-X-C chemokine receptor type-4 (CXCR-4), expression of this receptor in cancer cells has been related to metastasis. It has been identified that genistein-a soy-derived isoflavonoid-has anti-angiogenesis functions. We aimed to show the effects of this compound on VEGF and CXCR-4 in Acute lymphoblastic leukemia (ALL) cell models.

METHODS AND RESULTS

The cytotoxicity of Genistein was measured using the MTS colorimetric assay. After being treated with Genistein, the expression of VEGF in mRNA and protein levels was measured in MOLT-4 and Jurkat cells. We also used flow cytometry assay to determine the expression of CXCR-4 in cell surfaces. We found that Genistein decreased cell viability in two cell models while was more effective on MOLT-4 cells. After Genistein-treatment, surface expression levels of CXCR-4 were decreased, while VEGF secretion and mRNA expression levels were increased in MOLT-4 and Jurkat cells.

CONCLUSIONS

The results suggest that Genistein may not be a reliable choice for the treatment of ALL; however, this different identified pattern can be useful for the recognition of VEGF and CXCR-4 modulators and thus for planning new treatments for leukemia and other VEGF related disorders.

Studies on the Antioxidant and Cytotoxic Potentials of the Peel Extract of Dacryodes rostrata

Breast cancer is one type of cancer that causes the highest death in women in Indonesia. Alternative herbal-based cancer treatments have been developed, one of which is using fruits. Dacryodes rostrata, a fruit commonly consumed by residents in Kalimantan, is rich in antioxidants such as flavonoids and phenolics. The purpose of this study was to determine the value of antioxidant and cytotoxic activity of water and ethanol extract of D. rostrata peel against T-47D breast cancer cell lines. The fruit extraction was carried out by using maceration method. Antioxidant activity test using 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and cytotoxic test using MTT method (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenitetrazolium bromide) assay. The results showed that D. rostrata water and ethanol extract had antioxidant activity with IC50 values 121.7 ppm and 59.27 ppm, respectively. While cytotoxic effect on T-47D cells with IC50 values of 322.55 ppm and 143.02 ppm, respectively. This study showed that D. rostrata peel water extract had moderate antioxidant activity and moderate cytotoxic effect against T-47D breast cancer cells in vitro which could be used as a chemo preventive to prevent and inhibit cancer cell growth.

Targeting epigenetics in cancer: therapeutic potential of flavonoids

Irrespective of sex and age, cancer is the leading cause of mortality around the globe. Therapeutic incompliance, unwanted effects, and economic burdens imparted by cancer treatments, are primary health challenges. The heritable features in gene expression that are propagated through cell division and contribute to cellular identity without a change in DNA sequence are considered epigenetic characteristics and agents that could interfere with these features and are regarded as potential therapeutic targets. The genetic modification accounts for the recurrence and uncontrolled changes in the physiology of cancer cells. This review focuses on plant-derived flavonoids as a therapeutic tool for cancer, attributed to their ability for epigenetic regulation of cancer pathogenesis. The epigenetic mechanisms of various classes of flavonoids including flavonols, flavones, isoflavones, flavanones, flavan-3-ols, and anthocyanidins, such as cyanidin, delphinidin, and pelargonidin, are discussed. The outstanding results of preclinical studies encourage researchers to design several clinical trials on various flavonoids to ascertain their clinical strength in the treatment of different cancers. The results of such studies will define the clinical fate of these agents in future.

Liposome mediated-CYP1A1 gene silencing nanomedicine prepared using lipid film-coated proliposomes as a potential treatment strategy of lung cancer

The occurrence of lung cancer is linked with tobacco smoking, mainly through the generation of polycyclic aromatic hydrocarbons (PAHs). Elevated activity of cytochrome P4501A1 (CYP1A1) plays an important role in the metabolic processing of PAHs and its carcinogenicity. The present work aimed to investigate the role of CYP1A1 gene in PAH-mediated growth and tumor development in vitro and using an in vivo animal model. RNAi strategy was utilized to inhibit the overexpression of CYP1A1 gene using cationic liposomes generated using a lipid film-coated proliposome microparticles. Treatment of PAH-induced human alveolar adenocarcinoma cell line with cationic liposomes carrying CYP1A1 siRNA resulted in down regulation of CYP1A1 mRNA, protein as well as its enzymatic activity, triggering apoptosis and inhibiting multicellular tumor spheroids formation in vitro. Furthermore, silencing of CYP1A1 gene in BALB/c nude xenografts inhibited tumor growth via down regulation of CYP1A1 expression. Altogether, our findings showed that liposome-based gene delivery technology is a viable and stable approach for targeting cancer causing genes such as CY1PA1. This technology facilitated by the use of sugar particles coated with lipid films has demonstrated ability to generate anticancer effects that might be used in the future for therapeutic intervention and treatment of lung cancer.

In vitro safety assessment of the strawberry tree (Arbutus unedo L.) water leaf extract and arbutin in human peripheral blood lymphocytes

Strawberry tree (Arbutus unedo L.) leaves have long been used in the traditional medicine of the Mediterranean region. One of their most bioactive constituents is the glycoside arbutin, whose presence makes A. unedo suitable as a potential substitute for bearberry [Arctostaphylos uva ursi (L.) Spreng] leaves, an herbal preparation widely used for treating urinary tract infections. The safety and biocompatibility of strawberry tree water leaf extract have not yet been documented well. This study estimated arbutin content in strawberry tree water leaf extract (STE) using high performance liquid chromatography. Furthermore, we performed an in vitro safety assessment of the 24 h exposure to three presumably non-toxic concentrations of standardized STE and arbutin in human peripheral blood lymphocytes using the apoptosis/necrosis assay, the alkaline comet assay, and the cytokinesis-block micronucleus cytome assay. The STE was also tested for total antioxidant capacity and lipid peroxidation. At a concentration corresponding to the maximum allowable daily intake of arbutin, the tested extract was not cytotoxic, had a negligible potential for causing primary DNA damage and even hindered micronuclei formation in lymphocytes. It also showed a valuable antioxidant capacity, and did not exert marked lipid peroxidation. These promising results represent a solid frame for further development of STE-based herbal preparations. Although arbutin generally had a low DNA damaging potential, the slowing down of lymphocyte proliferation observed after 24 h of exposure points to a cytostatic effect, which merits further research.

Established Human Cell Lines as Models to Study Anti-leukemic Effects of Flavonoids

Despite the extensive work on pathological mechanisms and some recent advances in the treatment of different hematological malignancies, leukemia continues to present a significant challenge being frequently considered as incurable disease. Therefore, the development of novel therapeutic agents with high efficacy and low toxicity is urgently needed to improve the overall survival rate of patients. In this comprehensive review article, the current knowledge about the anticancer activities of flavonoids as plant secondary polyphenolic metabolites in the most commonly used human established leukemia cell lines (HL-60, NB4, KG1a, U937, THP-1, K562, Jurkat, CCRF- CEM, MOLT-3, and MOLT-4) is compiled, revealing clear anti-proliferative, pro-apoptotic, cell cycle arresting, and differentiation inducing effects for certain compounds. Considering the low toxicity of these substances in normal blood cells, the presented data show a great potential of flavonoids to be developed into novel anti-leukemia agents applicable also in the malignant cells resistant to the current conventional chemotherapeutic drugs.

Potentiation of luteolin cytotoxicity by flavonols fisetin and quercetin in human chronic lymphocytic leukemia cell lines

Despite numerous studies chronic lymphocytic leukemia (CLL) still remains an incurable disease. Therefore, all new compounds and novel strategies which are able to eradicate CLL cells should be considered as valuable clues for a potential future remedy against this malignancy. In the present study, the cytotoxic profiles of natural flavonoids were described in two human CLL cell lines, HG-3 and EHEB, indicating the flavone luteolin as the most potent flavonoid with half-maximal inhibitory constants (IC50) of 37 μM and 26 μM, respectively. Luteolin significantly increased the apoptotic cell population in both cell lines by increasing the activities of caspases-3 and -9 and triggering the intrinsic apoptotic pathway. Two flavonols, fisetin and quercetin, were somewhat less efficient in suppressing cellular viability, whereas baicalein, chrysin, (+)-catechin and hesperetin exerted only a small or no response at doses as high as 100 μM. Both fisetin and quercetin were able to augment the cytotoxic activity of luteolin in both cell lines by reducing the IC50 values up to four fold. As a result of this, luteolin displayed cytotoxicity activity already at low micromolar concentrations that could potentially be physiologically achievable through oral ingestion. No other tested flavonoids were capable of sensitizing CLL cells to luteolin pointing to a specific binding of fisetin and quercetin to the cellular targets which interfere with the signaling pathways induced by luteolin. Although further molecular studies to unravel this potentiating mechanism are certainly needed, this phenomenon could contribute to future remedies for prevention and treatment of chronic lymphocytic leukemia.