Combinations of parabens at concentrations measured in human breast tissue can increase proliferation of MCF‐7 human breast cancer cells

The alkyl esters of p‐hydroxybenzoic acid (parabens), which are used as preservatives in consumer products, possess oestrogenic activity and have been measured in human breast tissue. This has raised concerns for a potential involvement in the development of human breast cancer. In this paper, we have investigated the extent to which proliferation of MCF‐7 human breast cancer cells can be increased by exposure to the five parabens either alone or in combination at concentrations as recently measured in 160 human breast tissue samples. Determination of no‐observed‐effect concentrations (NOEC), lowest‐observed‐effect concentrations (LOEC), EC₅₀ and EC₁₀₀ values for stimulation of proliferation of MCF‐7 cells by five parabens revealed that 43/160 (27%) of the human breast tissue samples contained at least one paraben at a concentration ≥ LOEC and 64/160 (40%) > NOEC. Proliferation of MCF‐7 cells could be increased by combining all five parabens at concentrations down to the 50^th percentile (median) values measured in the tissues. For the 22 tissue samples taken at the site of ER + PR + primary cancers, 12 contained a sufficient concentration of one or more paraben to stimulate proliferation of MCF‐7 cells. This demonstrates that parabens, either alone or in combination, are present in human breast tissue at concentrations sufficient to stimulate the proliferation of MCF‐7 cells in vitro, and that functional consequences of the presence of paraben in human breast tissue should be assessed on the basis of all five parabens and not single parabens individually. Copyright © 2013 John Wiley & Sons, Ltd.     

Anticancer activity of VmCT1 analogs against MCF‐7 cells

Antimicrobial peptides are considered promising drug candidates due to their broad range of activity. VmCT1 (Phe–Leu–Gly–Ala–Leu–Trp–Asn–Val–Ala–Lys–Ser–Val–Phe–NH₂) is an α‐helical antimicrobial peptide that was obtained from the Vaejovis mexicanus smithi scorpion venom. Some of its analogs showed to be as antimicrobial as the wild type, and they were designed for understanding the influence of physiochemical parameters on antimicrobial and hemolytic activity. Some cationic antimicrobial peptides exhibit anticancer activity so VmCT1 analogs were tested to verify the anticancer activity of this family of peptides. The analogs were synthesized, purified, characterized, and the conformational studies were performed. The anticancer activity was assessed against MCF‐7 mammary cancer cells. The results indicated that [Glu]⁷‐VmCT1‐NH₂, [Lys]³‐VmCT1‐NH₂, and [Lys]⁷‐VmCT1‐NH₂ analogs presented moderated helical tendency (0.23–0.61) and tendency of anticancer activity at 25 μmol/L in 24 hr of experiment; and [Trp]⁹‐VmCT1‐NH₂ analog that presented low helical tendency and moderated anticancer activity at 50 μmol/L. These results demonstrated that single substitutions on VmCT1 led to different physicochemical features and could assist on the understanding of anticancer activity of this peptide family.     

Synthesis and cytotoxic activity of certain benzothiazole derivatives against human MCF‐7 cancer cell line

A new series of benzothiazole has been synthesized as cytotoxic agents. The new derivatives were tested for their cytotoxic activity toward the human breast cancer MCF‐7 cell line against cisplatin as the reference drug. Many derivatives revealed good cytotoxic effect, whereas four of them, 4, 5c, 5d, and 6b , were more potent than cisplatin, with IC₅₀ values being 8.64, 7.39, 7.56, and 5.15 μm compared to 13.33 μm of cisplatin. The four derivatives’ cytotoxic activity was accompanied by regulating free radicals production, by increasing the activity of superoxide dismutase and depletion of intracellular reduced glutathione, catalase, and glutathione peroxidase activities, accordingly, the high production of hydrogen peroxide, nitric oxide, and other free radicals causing tumor cell death as monitored by reduction in the synthesis of protein and nucleic acids. Most of the tested compounds showed potent to moderate growth inhibitory activity; in particular, compound 6b exhibited the highest activity suggesting it is a lead compound in cytotoxic activity.     

Ifosfamide metabolite chloroacetaldehyde inhibits cell proliferation and glucose metabolism without decreasing cellular ATP content in human breast cancer cells MCF‐7

Chloroacetaldehyde (CAA), a product of hepatic metabolism of the widely used anticancer drug ifosfamide (IFO), has been reported to decrease cancer cell proliferation. The basis of this effect is not completely known but has been attributed to a drop of cellular ATP content. Given the importance of glucose metabolism and of the ‘Warburg effect’ in cancer cells, we examined in the present study the ability of CAA to inhibit cancer cell proliferation by altering the glycolytic pathway. Cell proliferation, ATP content, glucose transport and metabolism as well as the activities of the main enzymes of glycolysis were determined in human breast cancer cells MCF‐7 in the presence of various CAA concentrations (5–50 μm ). Our results show that low CAA concentrations inhibited cell proliferation in a concentration‐dependent manner. This inhibition was explained by a decrease in glucose utilization. Cellular ATP content was not reduced but even increased with 25 μm CAA. The inhibition of glucose metabolism was mainly explained by the decrease in glucose transport and hexokinase activity. The activity of glyceraldehyde‐3‐phosphate dehydrogenase, but not that of phosphofructokinase, was also inhibited. Glycolysis inhibition by CAA was effective in decreasing the proliferation of MCF‐7 cells. Interestingly, this decrease was not due to ATP depletion; rather, it was linked to a drop of biosynthetic precursors from glycolytic intermediates. This CAA‐induced inhibition of cell proliferation suggests that it might play a role in the antitumor activity of IFO. Copyright © 2009 John Wiley & Sons, Ltd.     

Differences in the mechanisms of action of BDE‐47 and its metabolites on OVCAR‐3 and MCF‐7 cell apoptosis

Data concerning possible carcinogenic action of polybrominated diphenyl ethers (PBDEs) in hormone‐dependent tissues are limited. Our earlier studies showed that 2,2′,4,4′‐tetrabromodiphenyl ether (BDE‐47) stimulated OVCAR‐3 and MCF‐7 cell proliferation, while its hydroxylated metabolites (5‐OH‐BDE‐47 and 6‐OH‐BDE‐47) increased estrogen receptors protein expression and extracellular signal‐regulated kinase 1/2 and protein kinase Cα phosphorylation in these cell lines. In addition to cell proliferative disorder, a failure in the regulation of apoptosis can also lead to the formation and development of tumors. Therefore, in the present study, we investigated the effect of BDE‐47 and its metabolites (2.5–50 ng ml^–1) on the expression of apoptosis regulatory genes and proteins, caspase‐8 and ‐9 activity and DNA fragmentation induced by extracellular signal‐regulated kinase inhibitor (PD098059) and protein kinase Cα inhibitor (Gӧ 6976) in ovarian (OVCAR‐3) and breast (MCF‐7) cancer cells. In OVCAR‐3 cells, BDE‐47 upregulated expression of most of the investigated genes and increased protein expression of tumor necrosis factor (TNF)‐α, TNF receptor 1, caspase‐6, Bcl‐xl and caspase‐8 activity. Whereas in MCF‐7 cells, BDE‐47 resulted in the downregulation of most of the investigated genes, and decreased caspase‐8 and ‐9 activity. In both OVCAR‐3 and MCF‐7 cells, the expression of most of the investigated genes were downregulated by metabolites. Exposure of OVCAR‐3 cells to 5‐OH‐BDE‐47 corresponded with a decrease in the protein expression of caspase‐6, caspase‐9 and Bcl‐xl and treatment with 6‐OH‐BDE‐47 decreased Bcl‐xl and TNF receptor 1 expression in OVCAR‐3 cells and caspase‐9 expression in MCF‐7 cells. Hydroxylated metabolites of BDE‐47 have strong inhibitory effects on apoptosis in ovarian and breast tumor cells and thus should be considered potential carcinogens in hormone‐dependent cancers. Copyright © 2016 John Wiley & Sons, Ltd.     

In vitro profiling of toxicity and endocrine disrupting effects of bisphenol analogues by employing MCF‐7 cells and two‐hybrid yeast bioassay

The potentially adverse health implications of bisphenol A (BPA) have led to increasing use of alternative bisphenols (BPs). However, little is known about the toxicity of alternative BPs. In this study, the cytotoxicity, genotoxicity, intracellular ROS formation, and Ca²⁺ fluctuation effects of BPs on MCF‐7 cells were evaluated. At the same time, the estrogenic and thyroidal hormone effect potentials of six BPs were also evaluated using two‐hybrid yeast bioassay. The results showed that most BPs at 0.01–1 μM significantly increased cell viability in MCF‐7 cells and at higher exposure concentrations of 25–100 μM, they caused a significant decrease of cell viability. At the same time, these BPs also at 25–100 μM significantly increased LDH release of MCF‐7 cells. In addition, several BPs at 10–50 μM resulted in a significantly concentration‐depended increase in DNA‐damaging effect on MCF‐7 cells and elevated ROS production. Most BPs at 0.0001–10 μM significantly increased intracellular Ca²⁺ level. These results showed that bisphenol AF (BPAF) and thiodiphenol (TDP) exerted cell biological effect, estrogenic, and thyroidal effect potentials greater than those of BPA. The cytotoxicity and endocrine disrupting effects of other BPs are similar to or slightly lower than those of BPA. Therefore, as potential alternatives to BPA, endocrine disrupting effects and potential health harm of alternative BPs to human can also not be ignored. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 278–289, 2017.     

海绵来源的smenospongine诱导乳腺癌MCF7细胞凋亡机制研究

目的 研究海绵Spongia pertusa Esper来源的smenospongine（Sme）诱导乳腺癌细胞MCF7凋亡的作用机制。方法 使用CCK-8法检测Sme对MCF7细胞活力的影响;DAPI染色检测凋亡细胞的细胞核形态;使用流式细胞术检测细胞凋亡率和线粒体膜电位;Western blotting检测Sme对Bax、Bcl2、细胞色素C（cytochorome C）、p-p38和p38蛋白水平表达的影响。结果 CCK-8法检测结果表明,Sme抑制MCF7增殖,IC₅₀值为（16.46 ±0.88）μmol/L;DAPI染色结果和Annexin V-FITC/PI染色结果显示Sme诱导细胞凋亡。随着加药浓度的增加,细胞凋亡率从4.18%逐渐升至21.49%;流式细胞仪检测结果表明Sme引发MCF7细胞内线粒体膜电位下降;Western blotting结果显示Sme激活了内源性凋亡途径和p38丝裂源活化蛋白激酶（MAPK）信号通路。结论 Sme可能通过激活p38 MAPK通路,诱导细胞内源性凋亡发挥抗乳腺癌作用。     

Parabens enable suspension growth of MCF‐10A immortalized,non‐transformed human breast epithelial cells

Parabens (alkyl esters of p‐hydroxybenzoic acid) are used extensively as preservatives in consumer products, and intact esters have been measured in several human tissues. Concerns of a potential link between parabens and breast cancer have been raised, but mechanistic studies have centred on their oestrogenic activity and little attention has been paid to any carcinogenic properties. In the present study, we report that parabens can induce anchorage‐independent growth of MCF‐10A immortalized but non‐transformed human breast epithelial cells, a property closely related to transformation and a predictor of tumour growth in vivo. In semi‐solid methocel suspension culture, MCF‐10A cells produced very few colonies and only of a small size but the addition of 5 × 10^‐4 M methylparaben, 10^–5 M n‐propylparaben or 10^–5 M n‐butylparaben resulted in a greater number of colonies per dish (P < 0.05 in each case) and an increased average colony size (P < 0.001 in each case). Dose‐responses showed that concentrations as low as 10^–6 M methylparaben, 10^–7 M n‐propylparaben and 10^–7 M n‐butylparaben could increase colony numbers (P = 0.016, P = 0.010, P = 0.008, respectively): comparison with a recent measurement of paraben concentrations in human breast tissue samples from 40 mastectomies (Barr et al., 2012) showed that 22/40 of the patients had at least one of the parabens at the site of the primary tumour at or above these concentrations. To our knowledge, this is the first study to report that parabens can induce a transformed phenotype in human breast epithelial cells in vitro, and further investigation is now justified into a potential link between parabens and breast carcinogenesis. Copyright © 2012 John Wiley & Sons, Ltd.     

The estrogenic proliferative effects of two alkylphenols and a preliminary mechanism exploration in MCF‐7 breast cancer cells

Bisphenol A (BPA) and 4‐cumylphenol (4‐CP), as estrogen‐like chemicals, are ubiquitous in the environment media and associated with the occurrence and development of hormone‐dependent tumors. However, the combinatorial effects of these two structurally similar alkylphenols are not well informed. In the present study, the classic breast cancer cell line MCF‐7 was used as in vitro model to estimate the estrogenic proliferative effects of BPA and 4‐CP. MTT assay, reactive oxygen species, cell apoptosis, cell cycle, and real‐time fluorescent quantitative Step One Plus Real‐time PCR System (Applied Biosystems, CA, USA) were applied to explore their proliferative mechanisms. MTT results showed that both BPA and 4‐CP ranging from 10^?9 to 10^?5 M stimulated cell proliferation in a nonmonotonic dose‐response manner. Along with the proliferative effects, cell cycle was progressed from G0/G1 to S and G2/M phase. Meanwhile, the expression levels of ERα, pS2, and Bcl‐2 mRNA were also upregulated. In contrast, 4‐CP and BPA at high dose (10^?4 M) obviously displayed antiproliferative effects in MCF‐7 cells via inducing cell apoptosis and blocking cell cycle in G0/G1 phase. As expected, the relative expression levels of ERα, pS2, and Bcl‐2 mRNA were decreased, whereas Bax mRNA was increased. Interestingly, the proliferative or antiproliferative effects of 4‐CP were higher than that of BPA. Moreover, coexposure of lower concentrations BPA and 4‐CP significantly induced cell proliferation in a synergistic manner. These findings indicated that the potential environmental risks of coexposure of BPA and 4‐CP were greater than either of them.     

Different mechanisms of action of 2, 2’, 4, 4’‐tetrabromodiphenyl ether (BDE‐47) and its metabolites (5‐OH‐BDE‐47 and 6‐OH‐BDE‐47) on cell proliferation in OVCAR‐3 ovarian cancer cells and MCF‐7 breast cancer cells

Data concerning the possible action of polybrominated diphenyl ethers (PBDEs) in hormone‐dependent cancer are scarce. Some data showed that PBDEs may directly affect breast cancer cells formation and only one research showed increased proliferation of the OVCAR‐3 cells, but the results are ambiguous and the mechanisms are not clear. There is growing evidence that not only parent compounds but also its metabolites may be involved in cancer development. The present study was, therefore, designed to determine the effect of BDE‐47 and its metabolites (2.5 to 50 ng ml^–1) on proliferation (BrdU), cell‐cycle genes (real‐time PCR) and protein expression (Western blot), protein expression of oestrogen receptors (α β), extracellular signal‐regulated kinases 1 and 2 (ERK1/2) and protein kinase Cα (PKCα) in OVCAR‐3 ovarian and MCF‐7 breast cancer cells. In OVCAR‐3 cells, the parent compound stimulated cell proliferation by activating CDK1, CDK7, E2F1 and E2F2. Independent of time of exposure, BDE‐47 had no effect on ERα and ERβ protein expression and ERK1/2 and PKCα phosphorylation. Metabolites had no effect on cell proliferation but increased both ERs protein expression and ERK1/2 and PKCα phosphorylation. In MCF‐7 cells, the parent compound displayed no effect on cell proliferation but decreased ERα and increased ERβ protein expression with concomitant induction of PKCα phosphorylation. Both metabolites increased MCF‐7 cell proliferation, ERK1/2 and PKCα phosphorylation and decreased ERα and ERβ protein expression.We suggest that studies concerning PBDEs with fewer bromine atoms should be continued to understand environmental links to different hormone‐dependent cancers. Copyright © 2016 John Wiley & Sons, Ltd.     

MCF‐7 human mammary adenocarcinoma cells exhibit augmented responses to human insulin on a collagen IV surface

Human mammary cell lines are extensively used for preclinical safety assessment of insulin analogs. However, it is essentially unknown how mitogenic responses can be optimized in mammary cell‐based systems. We developed an insulin mitogenicity assay in MCF‐7 human mammary adenocarcinoma cells, under low serum (0.1% FCS) and phenol red‐free conditions, with 3H thymidine incorporation as endpoint. Based on EC50 values determined from 10‐fold dilution series, β‐estradiol was the most potent mitogen, followed by human IGF‐1, human AspB10 insulin and native human insulin. AspB10 insulin was significantly more mitogenic than native insulin, validating the ability of the assay to identify hypermitogenic human insulin analogs. With MCF‐7 cells on a collagen IV surface, the ranking of mitogens was maintained, but fold mitogenic responses and dynamic range and steepness of dose–response curves were increased. Also, PI3K pathway activation by insulin was enhanced on a collagen IV surface. This study provided the first determination and ranking of the mitogenic potencies of standard reference compounds in an optimized MCF‐7 assay. The optimized MCF‐7 assay described here is of relevance for in vitro toxicological testing and carcinogenicity safety assessment of new insulin compounds. Copyright © 2009 John Wiley & Sons, Ltd.     

Pyridine‐substituted thiazolylphenol derivatives: Synthesis,modeling studies,aromatase inhibition,and antiproliferative activity evaluation

Drugs used in breast cancer treatments target the suppression of estrogen biosynthesis. During this suppression, the main goal is to inhibit the aromatase enzyme that is responsible for the cyclization and structuring of estrogens either with steroid or non‐steroidal‐type inhibitors. Non‐steroidal derivatives generally have a planar aromatic structure attached to the triazole ring system in their structures, which inhibits hydroxylation reactions during aromatization by coordinating the heme group. Bioisosteric replacement of the triazole ring system and development of aromatic/cyclic structures of the side chain can increase the selectivity for aromatase enzyme inhibition. In this study, pyridine‐substituted thiazolylphenol derivatives, which are non‐steroidal triazole bioisosteres, were synthesized using the Hantzsch method, and physical analysis and structural determination studies were performed. The IC₅₀ values of the compounds were determined by a fluorescence‐based aromatase inhibition assay. Then, their antiproliferative activities on the MCF7 and HEK 293 cell lines were evaluated with the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay. Furthermore, the crystal structure of human placental aromatase was subjected to a series of docking experiments to identify the possible interactions between the most active structure and the active site. Lastly, an in silico technique was performed to analyze and predict the drug‐likeness, molecular and ADME properties of the synthesized molecules.

     

Estrogenic effects of fluorinated diiodine alkanes in MCF‐7 cells,H295R cells and zebrafish embryo assays

Fluorinated diiodine alkanes (FDIAs), important industrial intermediates in the synthesis of various perfluorinated compounds, which are distributed widely in wildlife and humans. Recent studies showed that FDIAs had in vitro estrogenic effects. However, to date, little information is available regarding the in vivo estrogenic effects of FDIAs and the mechanisms are unclear. In this study, a combination of in vitro and in vivo assays was used to investigate the estrogenic effects of FDIAs. We tested the in vitro estrogenic effects and estrogen receptor‐related gene expression via MCF‐7 cell assay. The hormone level of estradiol and the expression of estrogenic synthesis genes were measured in the H295R cell assay. Finally, the in vivo effects of FDIAs on development and estrogen‐related gene expression were assessed in the zebrafish embryos assay. The results demonstrated that FDIAs could exhibit estrogenic activity through inducing cell proliferation (1.6‐6.7‐fold of the control) and estrogen receptor alpha gene expression (1.07‐1.39‐fold of the control), altering estradiol production (1.14‐1.22‐fold of the control) and the major estrogenic synthesis gene expression of CYP19 (1.22‐1.31‐fold of the control), disrupting the estrogen‐related genes (esr1 and cyp19b) levels in zebrafish (1.52‐2.99‐fold and 2.95‐5.00‐fold of the control for esr1 and cyp19b, respectively). The current findings indicated the potential estrogenic effects of FDIAs and provided novel information for human risk assessment.     

Oestrogenic activity of mimosine on MCF‐7 breast cancer cell line through the ERα‐mediated pathway

Hormone replacement therapy has been a conventional treatment for postmenopausal symptoms in women. However, it has potential risks of breast and endometrial cancers. The aim of this study was to evaluate the oestrogenicity of a plant‐based compound, mimosine, in MCF‐7 cells by in silico model. Cell viability and proliferation, ERα‐SRC1 coactivator activity and expression of specific ERα‐dependent marker TFF1 and PGR genes were evaluated. Binding modes of 17β‐oestradiol and mimosine at the ERα ligand binding domain were compared using docking and molecular dynamics simulation experiments followed by binding interaction free energy calculation with molecular mechanics/Poisson–Boltzmann surface area. Mimosine showed increased cellular viability (64,450 cells/ml) at 0.1 μM with significant cell proliferation (120.5%) compared to 17β‐oestradiol (135.2%). ER antagonist tamoxifen significantly reduced proliferative activity mediated by mimosine (49.9%). Mimosine at 1 μM showed the highest ERα binding activity through increased SRC1 recruitment at 186.9%. It expressed TFF1 (11.1‐fold at 0.1 μM) and PGR (13.9‐fold at 0.01 μM) genes. ERα‐mimosine binding energy was ?49.9 kJ/mol, and it interacted with Thr347, Gly521 and His524 of ERα‐LBD. The results suggested that mimosine has oestrogenic activity.     

Metformin enhances doxorubicin sensitivity via inhibition of doxorubicin efflux in P‐gp‐overexpressing MCF‐7 cells

Resistance against chemotherapy is still a major problem in successful cancer treatment in the clinic. Therefore, identifying new compounds with lower side‐effects and higher efficacy is an important approach to overcome multidrug resistance (MDR). Here, we investigated the activity and possible mechanism of the antidiabetic drug, metformin, in human doxorubicin (DOX)‐resistant breast cancer (MCF‐7/DOX) cells. The effect of metformin on the cytotoxicity of DOX was evaluated by MTT assay. The P‐gp mRNA/protein expression levels following treatment with metformin were determined using real‐time polymerase chain reaction and Western blot analysis, respectively. Intracellular rhodamine 123 accumulation assay was performed to evaluate the P‐gp function. Cellular ATP content was determined using ATP assay kit. The effect of metformin on DOX‐induced apoptosis was evaluated by annexin V/FITC assay. Exposure to metformin considerably enhanced the cytotoxicity of DOX. Metformin had no substantial effect on P‐gp expression, while the activity of P‐gp and intracellular ATP content decreased with metformin treatment in a dose‐dependent manner. Furthermore, metformin significantly increased the DOX‐induced apoptosis. These results indicate that metformin could reverse MDR in breast cancer cells by reducing P‐gp activity. Therefore, metformin can be suggested as a potent adjuvant in breast cancer chemotherapy.     

Differential effect of methyl‐, butyl‐ and propylparaben and 17β‐estradiol on selected cell cycle and apoptosis gene and protein expression in MCF‐7 breast cancer cells and MCF‐10A non‐malignant cells

Parabens are alkyl esters of p‐hydroxybenzoic acid used widely as antimicrobial preservatives in consumer products, including pharmaceuticals, foods and cosmetics. We showed previously that methyl‐, butyl‐ and propylparaben parabens, even at low doses, stimulate the proliferation of MCF‐7 breast cancer cells and non‐transformed MCF‐10A breast epithelial cells. The present study was undertaken to determine whether this represents a direct effect on cell cycle and apoptotic gene expression. MCF‐7 and MCF‐10A cells were exposed to methyl, butyl‐ and propylparaben (20 nm ) or 17β‐estradiol (10 nm ). Cell cycle and apoptotic gene expression were evaluated by real‐time polymerase chain reaction and protein expression by Western blot. 17β‐estradiol upregulated G₁/S phase genes and downregulated cell cycle progression inhibitors in both MCF‐7 and MCF‐10A. Upregulation of Bcl‐xL and downregulation of caspase 9 was observed in MCF‐7, while upregulation of Bcl‐xL, BCL2L2 and caspase 9 was noted in MCF‐10A. Cyclins in MCF‐7 cells were not affected by any of the parabens. Methyl‐ and butylparaben had no effect on the expression of selected apoptotic genes in MCF‐7. In MCF‐10A, all parabens tested increased the expression of G₁/S phase genes, and downregulated cell cycle inhibitors. Methylparaben increased pro‐survival gene. Butylparaben increased BCL2L1 gene, as did 17β‐estradiol, while propylparaben upregulated both the extrinsic and intrinsic apoptotic pathways. There are differences in cell cycle and apoptosis gene expression between parabens and 17β‐estradiol in MCF‐7 cells. In MCF‐10A cells, most of the genes activated by parabens were comparable to those activated by 17β‐estradiol. Copyright © 2014 John Wiley & Sons, Ltd.     

Apoptotic and antiproliferative properties of 3β‐hydroxy‐Δ5‐steroidal congeners from a partially purified column fraction of Dendronephthya gigantea against HL‐60 and MCF‐7 cancer cells

Organisms belonging to the genus Dendronephthya are among a group of marine invertebrates that produce a variety of terpenoids with biofunctional properties. Many of these terpenoids have been proven effective as anticancer drugs. Here, we report the antiproliferative effect of 3β‐hydroxy‐Δ5‐steroidal congeners against the proliferation of HL‐60 human leukemia cells and MCF‐7 human breast cancer cells. The sterol‐rich fraction (DGEHF2‐1) inhibited the growth of HL‐60 and MCF‐7 cells with IC₅₀ values of 13.59 ± 1.40 and 29.41 ± 0.87 μg ml^–1 respectively. Treatment with DGEHF2‐1 caused a dose‐dependent increase in apoptotic body formation, DNA damage and the sub‐G₁ apoptotic cell population. Moreover, DGEHF2‐1 downregulated the expression of Bcl‐xL while upregulating Bax, caspase‐9, and PARP cleavage in both HL‐60 and MCF‐7 cells. The steroid fraction was found to act via the mitochondria‐mediated apoptosis pathway. Identification of the sterols was performed via gas chromatography–tandem mass spectrometry analysis. Studying the mechanism of the anticancer effect caused by these sterol derivatives could lead to the identification of other natural products with anticancer properties.