Caspase mediated enhanced apoptotic action of cyclophosphamide- and resveratrol-treated MCF-7 cells

Combining Chemotherapy Agents and Autophagy Modulators for Enhanced Breast Cancer Cell Death

Purpose

Autophagy, governed by genes with dual roles in cell death and survival, plays a crucial role in cancer persistence. Arsenic trioxide (ATO), carboplatin (CP), and cyclophosphamide (CY) are used to treat various cancers. ATO impedes cell proliferation and triggers apoptosis in cancer cells. CP, a platinum-based drug, damages cancer cell DNA, while CY acts as an alkylating agent, disrupting cell proliferation. This study investigates the combined effects of ATO, CP, and CY on inducing apoptosis and modulating autophagy in triple-negative breast cancer (TNBC) cell lines, BT-20 and MDA-MB-231.

Methods

The cytotoxic effects of ATO, CP, and CY, alone and in combination, were evaluated using the MTT assay on BT-20 and MDA-MB-231 cells. Apoptosis and cell cycle progression were analyzed by annexin-V FITC/PI staining and flow cytometry. Gene expression of autophagy-and apoptosis-related markers, including Beclin 1, LC3, caspase 3, and BCL2, was quantified using RT-PCR. Data were analyzed using GraphPad Prism 4.0 with one-way ANOVA followed by Dunnett's test.

Results

The combination of ATO, CP, and CY significantly reduced cell viability and enhanced apoptosis, evidenced by increased caspase-3 activity and reduced BCL2 expression. Cell cycle arrest in the G1 phase was observed, alongside elevated autophagy markers Beclin 1 and LC3.

Conclusion

The combination of ATO, CP, and CY induces synergistic effects in promoting apoptosis and autophagy in TNBC cell lines. These findings suggest that this combination therapy could be a promising approach to enhancing treatment efficacy in aggressive breast cancers, offering new insights into potential therapeutic strategies.

Unleashing the antitumor power of cyclophosphamide by arabinogalactan and aptamer conjugation

Cyclophosphamide (CPA) (2-oxo-2-di(β-chloroethyl)amino tetrahydro-2,1,3-phosphoxazine) is an alkylating cytostatic compound with a broad spectrum of antitumor activity. Despite its efficacy, the clinical application of CPA is hindered by the significant occurrence of adverse side effects. To address these limitations, a promising approach involves the mechanochemical treatment of CPA with arabinogalactan (AG) to facilitate the dispersion of the drug within the AG matrix. AG stands out from other polymers due to its uniformity, low molecular weight, water solubility, and ability to form drug conjugates, thereby enhancing their therapeutic potency. Moreover, AG possesses immune-modulating properties that have the potential to counteract the immunosuppressive effects induced by CPA. By means of mechanical treatment, we successfully obtained CPA-AG complexes with a CPA:AG ratio of 1:10. These complexes were further modified with As42 aptamers that specifically target Erlich ascites cells. Aptamers, a novel class of oligonucleotide ligands obtained through SELEX technology, possess high affinity and specificity for binding to various receptors. An ascitic form of Ehrlich carcinoma was chosen as an in vitro and in vivo tumor model due to its notable drug resistance. In vitro and in vivo evaluations were conducted to compare the antitumor activity of both the CPA-AG and CPA-AG-As42 complexes with pure CPA. In vitro experiments revealed that the CPA-AG complex displayed superior antitumor activity compared to pure CPA, leading to complete tumor cell death primarily through necrosis. Notably, no toxic effects were observed with the CPA-AG and CPA-AG-As42 complexes, and they significantly prolonged the lifespan of tumor-bearing mice by more than 3.5 times. Histological studies further supported the antitumor efficacy of these complexes. These results underscore the potential of utilizing CPA-AG mechanocomposites, functionalized with aptamers, for the targeted delivery of CPA to tumors.

The bovine dialyzable leukocyte extract, immunepotent CRP, synergically enhances cyclophosphamide-induced breast cancer cell death, through a caspase-independent mechanism

Breast cancer (BC) is one of the leading causes of cancer death worldwide. Cyclophosphamide (CTX) remains a mainstay in cancer therapy despite harmful adverse effects and cell death-resistances. To face this, combinational therapy of chemotherapies and immunotherapies has been proposed. IMMUNEPOTENT CRP (ICRP) is an immunotherapy that has cytotoxic effects in several cancer cells without affecting peripheral blood mononuclear cells (PBMC) and CD3+ cells. The aim of this study was to evaluate cytotoxicity, the type of cytotoxic effect, and several features involved in cell death induced by the combination of CTX with ICRP (ICRP+CTX) in breast cancer cells as well as their effect on healthy cells. For this purpose, human and murine breast cancer cells, MCF-7, MDA-MB-231 and 4T1, or PBMC were treated for 24 hours with ICRP, CTX or ICRP+CTX in different combination ratios for the assessment of cell death. Flow cytometry and microscopy were used to determine biochemical and morphological characteristics of cell death. Assays showed that ICRP in combination with CTX induce potentiated cell death manifested with morphological changes, loss of mitochondrial membrane potential, reactive oxygen species (ROS) production, and caspase activation. In addition, it was determined that ICRP+CTX-cell death is caspase-independent in all the breast cancer cells assessed. On the other hand, ICRP did not affect CTX-cytotoxicity in PBMC. For all the above, we can propose that the combination of ICRP with CTX an effective combination therapy, promoting their use even in tumoral cells with defects on proteins implicated in the apoptotic pathway.

A parallelized, perfused 3D triculture model of leukemia for in vitro drug testing of chemotherapeutics

Leukemia patients undergo chemotherapy to combat the leukemic cells (LCs) in the bone marrow. During therapy not only the LCs, but also the blood-producing hematopoietic stem and progenitor cells (HSPCs) may be destroyed. Chemotherapeutics targeting only the LCs are urgently needed to overcome this problem and minimize life-threatening side-effects. Predictive in vitro drug testing systems allowing simultaneous comparison of various experimental settings would enhance the efficiency of drug development. Here, we present a 3D human leukemic bone marrow model perfused using a magnetic, parallelized culture system to ensure media exchange. Chemotherapeutic treatment of the acute myeloid leukemia cell line KG-1a in 3D magnetic hydrogels seeded with mesenchymal stem/stromal cells (MSCs) revealed a greater resistance of KG-1a compared to 2D culture. In 3D tricultures with HSPCs, MSCs and KG-1a, imitating leukemic bone marrow, HSPC proliferation decreased while KG-1a cells remained unaffected post treatment. Non-invasive metabolic profiling enabled continuous monitoring of the system. Our results highlight the importance of using biomimetic 3D platforms with proper media exchange and co-cultures for creating in vivo-like conditions to enable in vitro drug testing. This system is a step towards drug testing in biomimetic, parallelized in vitro approaches, facilitating the discovery of new anti-leukemic drugs.

Effects of Green cardamom (Elettaria cardamomum Maton) and its combination with cyclophosphamide on Ehrlich solid tumors

Background

Cardamom (Elettaria cardamomum) is a spice and exhibits potent antioxidant and biological activities through distinct molecular mechanisms. However, the anticancer effect of cardamom was not explored yet in Ehrlich solid tumor (EST)-bearing mice.

Objectives

This investigation was aimed to evaluate the anti-cancer effects of green cardamom (GCar) alone or combined with the anti-cancer drug cyclophosphamide in an in vivo model to explore its mechanistic role in tumor cell death in EST-bearing mice.

Methods

Ehrlich ascites tumor cells were injected in the mice and 5 days later the animals treated with GCar and/or cyclophosphamide for 10 days. Twenty-four hours from the last treatment, animals were sacrificed for the different measurements.

Results

Data recorded for tumor size, percentage of tumor growth inhibition, tumor growth delay and mean survival time of EST-bearing mice demonstrated the effective role of GCar alone or combined with CPO as a promising anti-cancer agent because it reduced tumor size. GCar elevated the mean survival time of EST-bearing mice compared to that of untreated EST and EST + CPO groups. Analysis of qPCR mRNA gene and protein expression revealed that GCar alone or combined with CPO were promising anticancer agents. After the treatment of EST with GCar, the apoptotic-related genes and proteins were significantly modulated. GCar induced markedly significant decreases in oxidative stress biomarkers and a significant increment in glutathione levels and that of antioxidant enzymes. With a marked diminish in liver and kidney function biomarkers.

Conclusion

The results revealed that GCar could serve as an apoptotic stimulator agent, presenting a novel and potentially curative approach for cancer treatment, inducing fewer side effects than those of the commercially used anti-cancer drugs, such as CPO.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03305-2.

Marine anticancer drugs and their relevant targets: a treasure from the ocean

Marine organisms comprising animals and plants are wealthiest sources of bioactive compounds possessing various pharmacological properties specifically: free radical scavenging, antitumor, antimicrobial, analgesic, neuroprotective and immunomodulatory. Marine drugs provide an alternative source to meet the demand of effective, safe and low-cost drugs that are rising with the continuously growing world population. Cancer is one of the leading reasons of mortality in western nations in contrast to communicable diseases of developing nations. In spite of outstanding developments in cancer therapy in past three decades, there is still an insistent necessity for innovative drugs in the area of cancer biology, especially in the unexplored area of marine anticancer compounds. However, recent technological innovations in structure revelation, synthetic creation of new compounds and biological assays have made possible the isolation and clinical assessment of innumerable unique anticancer compounds from marine environment. This review provides an insight into the anticancer research so far conducted in the area of the marine natural products/synthetic derivatives, their possible molecular targets and the current challenges in the drug development. Graphical abstract.

Leveraging the Cardio-Protective and Anticancer Properties of Resveratrol in Cardio-Oncology

Cardio-oncology is a clinical/scientific discipline which aims to prevent and/or treat cardiovascular diseases in cancer patients. Although a large number of cancer treatments are known to cause cardiovascular toxicity, they are still widely used because they are highly effective. Unfortunately, therapeutic interventions to prevent and/or treat cancer treatment-induced cardiovascular toxicity have not been established yet. A major challenge for such interventions is to protect the cardiovascular system without compromising the therapeutic benefit of anticancer medications. Intriguingly, the polyphenolic natural compound resveratrol and its analogs have been shown in preclinical studies to protect against cancer treatment-induced cardiovascular toxicity. They have also been shown to possess significant anticancer properties on their own, and to enhance the anticancer effect of other cancer treatments. Thus, they hold significant promise to protect the cardiovascular system and fight the cancer at the same time. In this review, we will discuss the current knowledge regarding the cardio-protective and the anticancer properties of resveratrol and its analogs. Thereafter, we will discuss the challenges that face the clinical application of these agents. To conclude, we will highlight important gaps of knowledge and future research directions to accelerate the translation of these exciting preclinical findings to cancer patient care.

Programmed Cell Death, from a Cancer Perspective: An Overview

Programmed cell death (PCD) is probably the most widely discussed subject among the topics of cancer therapy. Over the last 2 decades an astonishing boost in our perception of cell death has been seen, and its role in cancer and cancer therapy has been thoroughly investigated. A number of discoveries have clarified the molecular mechanism of PCD, thus expounding the link between PCD and therapeutic tools. Even though PCD is assumed to play a major role in anticancer therapy, the clinical relevance of its induction remains uncertain. Since PCD involves multiple death programs including programmed necrosis and autophagic cell death, it has contributed to our better understanding of cancer pathogenesis and therapeutics. In this review, we discuss a brief outline of PCD types as well as their role in cancer therapeutics. Since irregularities in the cell death process are frequently found in various cancers, key proteins governing cell death type could be used as therapeutic targets for a wide range of cancer.

Apoptosis induction in human breast cancer cell lines by synergic effect of raloxifene and resveratrol through increasing proapoptotic genes

AIMS

Breast cancer is the most common cancer of women. The aim of this study was to investigate the synergic effect of raloxifene (Ral) and resveratrol (Res) on apoptosis of breast cancer cell lines (MCF7 and MDA-MB-231).

MAIN METHODS

Cells were treated with Ral and Res alone and in combination. Cell viability (MTT assay), apoptosis (TUNEL assay) and nitric oxide (NO) production (Griess method) were investigated. Expression of proapoptotic gene (Bax and p53), anti-apoptotic gene (Bcl2) and caspases-3, caspase -8 were evaluated. One-way ANOVA test was used for data analysis.

KEY FINDINGS

The viabilities of MCF7 and MDA-MB-231 cells treated by Ral (1 μM) and Res (20 μM) decreased significantly (p = 0.000) and their synergic use showed more reduction. Nitric oxide production by MCF7 and MDA-MB-231 cells exposed upon each drug alone and in combination showing a significant reduction (p = 0.000). There was also an increase in apoptosis in the cells treated with combination use of Ral and Res in both cell lines. Moreover, reduced expression of Bcl2 and increased expression of Bax and p53 genes were observed.

SIGNIFICANCE

The synergic effects of Ral and Res through increased ratio of Bcl2/Bax and expressions of p53, caspase-3 and caspase-8 genes indicating a better therapeutic effect on breast cancer cells relative to each drug alone. Combination of Res and Ral via increased expression of apoptotic genes including Bax, p53 and caspase-3 and caspase-8 is able to promote apoptosis as a mitochondrial dependent pathway in MCF7 and MDA-MB-231. The synergic effect was more potent in MCF7 estrogen receptor positive cell line.

Resveratrol induces mitochondria-mediated, caspase-independent apoptosis in murine prostate cancer cells

Found in the skins of red fruits, including grapes, resveratrol (RES) is a polyphenolic compound with cancer chemopreventive activity. Because of this activity, it has gained interest for scientific investigations. RES inhibits tumor growth and progression by targeting mitochondria-dependent or -independent pathways. However, further investigations are needed to explore the underlying mechanisms.

The present study is focused on examining the role of RES-induced, mitochondria-mediated, caspase-independent apoptosis of prostate cancer cells, namely transgenic adenocarcinoma of mouse prostate (TRAMP) cells. These cells were exposed to RES for various times, and cell killing, cell morphology, mitochondrial membrane potential (Δψm), expression of Bax and Bcl2 proteins, the role of caspase-3, and DNA fragmentation were analyzed.

TRAMP cells exposed to RES showed decreased cell viability, altered cell morphology, and disrupted Δψm, which led to aberrant expression of Bax and Bcl2 proteins. Furthermore, since the caspase-3 inhibitor, z-VAD-fmk (benzyloxycarbonyl-valine-alanine-aspartic acid-fluoromethyl ketone), had no appreciable impact on RES-induced cell killing, the killing was evidently caspase-independent. In addition, RES treatment of TRAMP-C1, TRAMP-C2, and TRAMP-C3 cells caused an appreciable breakage of genomic DNA into low-molecular-weight fragments.

These findings show that, in inhibition of proliferation of TRAMP cells, RES induces mitochondria-mediated, caspase-independent apoptosis. Therefore, RES may be utilized as a therapeutic agent to control the proliferation and growth of cancer cells.

Exploring the Cytotoxic Potential of Triterpenoids-enriched Fraction of Bacopa monnieri by Implementing In vitro, In vivo, and In silico Approaches

Background:

Bacopa monnieri (BM) is a herbaceous plant traditionally used from time immemorial in Ayurvedic and folklore medicines. We hypothesized that the extract of the whole plant might contain numerous molecules with having antitumor activities that could be very effective in killing of human cancer cells.

Objectives:

This work investigated anticancer activity of bioactive fraction of BM.

Materials and Methods:

The hydroalcoholic extract of BM was fractionated with different solvent, namely, hexane, dichloromethane (DCM), acetone, methanol, and water. The in vitro anticancer activity was performed against various Human Cancer Cell lines, namely, Colon (HT29, Colo320, and Caco2), Lung (A549), Cervix (HeLa, SiHa), and Breast (MCF-7, MDAMB-231). Further, DCM fraction was evaluated in vivo for anticancer activity against Ehrlich ascites carcinoma (EAC) tumor-bearing mice since it showed the best cytotoxicity at 72 h (IC₅₀ 41.0–60.0 µg/mL). The metabolic fingerprinting of these extract were carried out using high-performance thin-layer chromatography along with quantification of bacoside A, bacoside B, cucurbitacin B, cucurbitacin E, and bittulinic acid.

Results:

Oral administration of DCM fraction at a dose of 40 mg/kg rendered prominent reduction of tumor regression parameters such as tumor weight, packed cell volume, tumor volume and viable tumor cell count as compared to the untreated mice of the EAC control group. The anticancer activity of DCM fraction may be due to the presence of large amount of bacoside A, B and cucurbitacins. The molecular docking studies of major metabolites with targeted proteins predicted the anticancer activity of DCM fraction which was in support of in vivo activity.

Conclusion:

The in vitro, in vivo, analytical and in silico studies on DCM fraction of Bacopa monieri has proved its great potential for development of anticancer phytopharmaceuticals.

SUMMARY

A new HPTLC method has been developed and validated for the qualitative and quantitative analysis of bacoside A, B, cucurbitacin B, D, E and bittulinic acid in Bacopa monnieri extract. Enrichment of active anticancer metabolites was done by polarity based fractionations of hydroalcoholic extract of Bacopa. DCM fraction of a hydroalcoholic extract of Bacopa showed anticancer potential against human cancer cell line (IC50 41.0-60.0 µg/mL) and in EAC treated mice (at a dose of 40 mg/kg body weight). The anticancer activity of Bacopa may be due to the presence of bacosides and cucurbitacin and it was confirmed by in silico screening.

Abbreviations used: DBM: DCM fraction of Bacopa monnieri; DCM: Dichloromethane; EAC: Ehrlich ascites carcinoma; HCT: Hematocrit; HGB: Hemoglobin; HPTLC: High performance thin layer chromatography; ICH: International council for Harmonisation; LOD: Limit of detection; LOQ: Limit of quantification; LYM: Lymphocytes; MCH: Mean corpuscular hemoglobin; MCHC: Mean corpuscular haemoglobin concentration (MCHC); MCV: Mean corpuscular volume; MTT: 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; PLT: Platelet; RBC: Red blood cell; RDW: Red blood cell distribution width; RSD: Relative standard deviation; WBC: White blood cells.

Both p62/SQSTM1-HDAC6-dependent autophagy and the aggresome pathway mediate CDK1 degradation in human breast cancer

Cyclin-dependent kinase 1 (CDK1) is the central mammalian regulator of cell proliferation and a promising therapeutic target for breast cancer. In fact, CDK1 inhibition downregulates survival and induces apoptosis. Due to its essential role, CDK1 expression and activity are strictly controlled at various levels. We previously described that CDK1 stability is also regulated and that SCF(βTrCP) ubiquitinates CDK1, which is degraded via the lysosomal pathway. In addition, in breast tumors from patients, we found a negative correlation between CDK1 accumulation and βTrCP levels, and a positive correlation with the degree of tumor malignancy. This prompted us to study the molecular mechanism involved in CDK1 clearance. In this report, we determine that both chemotherapeutic agents and proteolytic stress induce CDK1 degradation in human breast cancer MCF7 cells through p62/HDAC6-mediated selective autophagy. On the one hand, CDK1 binds to p62/SQSTM1-LC3 and, on the other hand, it interacts with HDAC6. Both complexes are dependent on the presence of an intact βTrCP-binding motif on CDK1. Furthermore, we also show that CDK1 is recruited to aggresomes in response to proteasome inhibition for an extended period. We propose CDK1 clearance as a potential predictive biomarker of antitumor treatment efficacy.

Resveratrol inhibits adventitial fibroblast proliferation and induces cell apoptosis through the SIRT1 pathway

Atherosclerosis is one of the most important causes of cardiovascular disease and studies have showed that adventitial fibroblasts, which are considered to be the most common cell type of the vascular adventitia, are involved in the development of early atherosclerotic plaques. Resveratrol is a plant polyphenolic compound confirmed to have anti‑atherosclerotic and cardioprotective effects. The aim of the present study was to investigate the effects of resveratrol on adventitial fibroblasts in vitro and to clarify the underlying mechanism. Adventitial fibroblasts were isolated from the thoracic aorta of 8‑week‑old SPF Sprague‑Dawley rats. Following pre‑treatment with different concentrations of resveratrol, cell viability, DNA synthesis ability, cell apoptosis and cell migration ability were assessed in vitro. Through transfection with small interfering (si)RNA targeting sirtuin 1 (SIRT1), the role of the SIRT1 pathway in these processes was evaluated. Western blot analysis was used to assess the protein expression of SIRT1. It was demonstrated that resveratrol inhibited the cell viability, DNA synthesis and migratory ability of the adventitial fibroblasts, and induced cell apoptosis in a concentration‑dependent manner in vitro. These effects were partly through the SIRT1 pathways. siRNA targeting SIRT1 successfully reversed the antiproliferative, antimigratory and pro‑apoptotic effects of resveratrol on adventitial fibroblasts. In conclusion, the data showed that resveratrol inhibited cell viability, DNA synthesis and cell migration, and induced cell apoptosis in the rat adventitial fibroblasts in vitro through the SIRT1 signaling pathway. As the activation and migration of adventitial fibroblasts contributes to the early development of atherosclerosis, this may be a mechanism underlying the anti‑atherosclerotic effect of resveratrol.

Inhibition of cancer cell growth by ruthenium complexes

Background

Previous studies suggest that certain transition metal complexes, such as cisplatin, are efficacious for treating various cancer types, including ovarian, lung, and breast.

Methods

In order to further evaluate ruthenium (Ru) complexes as potential anti-cancer agents, we synthesized and evaluated Ru-arene complexes. Two complexes with the general formula [Ru (η⁶-p-cym) (N–N) Cl]⁺ were tested for their abilities to inhibit cancer cells.

Results

The complex with o-phenylenediamine as the N–N ligand (o-PDA) significantly inhibited growth of breast (MDA-MB-231, MCF-7, SKBR-3, and SUM149), lymphoma (Raji), melanoma (Bowes), and osteosarcoma (HT1080); however, the complex with o-benzoquinonediimine (o-BQDI) was ineffective except for SUM149. In contrast, o-PDA failed to inhibit growth of human breast epithelial cells, MCF-10A. Treatment of MDA-MBA-231 cells with o-PDA resulted in a significant reduction of productions of PDGF-AA, GM-CSF, and VEGF-A proteins at the transcriptional levels. Finally, we demonstrated that o-PDA synergistically inhibited MDA-MB-231 cell growth with cyclophosphamide but not doxorubicin or paclitaxel.

Conclusion

These results suggest that Ru-arene complexes are promising anti-cancer drugs that inhibit progression and metastasis by blocking multiple processes for breast and other types of cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0797-9) contains supplementary material, which is available to authorized users.

Resveratrol for breast cancer prevention and therapy: Preclinical evidence and molecular mechanisms

Globally, breast cancer is the most frequently diagnosed cancer among women. The major unresolved problems with metastatic breast cancer is recurrence after receiving objective response to chemotherapy, drug-induced side effects of first line chemotherapy and delayed response to second line of treatment. Unfortunately, very few options are available as third line treatment. It is clear that under such circumstances there is an urgent need for new and effective drugs. Phytochemicals are among the most promising chemopreventive treatment options for the management of cancer. Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a non-flavonoid polyphenol present in several dietary sources, including grapes, berries, soy beans, pomegranate and peanuts, has been shown to possess a wide range of health benefits through its effect on a plethora of molecular targets.The present review encompasses the role of resveratrol and its natural/synthetic analogue in the light of their efficacy against tumor cell proliferation, metastasis, epigenetic alterations and for induction of apoptosis as well as sensitization toward chemotherapeutic drugs in various in vitro and in vivo models of breast cancer. The roles of resveratrol as a phytoestrogen, an aromatase inhibitor and in stem cell therapy as well as adjuvent treatment are also discussed. This review explores the full potential of resveratrol in breast cancer prevention and treatment with current limitations, challenges and future directions of research.

Role of Natural Stilbenes in the Prevention of Cancer

Natural stilbenes are an important group of nonflavonoid phytochemicals of polyphenolic structure characterized by the presence of a 1,2-diphenylethylene nucleus. Stilbenes have an extraordinary potential for the prevention and treatment of different diseases, including cancer, due to their antioxidant, cell death activation, and anti-inflammatory properties which associate with low toxicity under in vivo conditions. This review aims to discuss various approaches related to their mechanisms of action, pharmacological activities in animal models and humans, and potential chemoprevention in clinical studies. The biological activity of natural stilbenes is still incompletely understood. Furthermore, after administration to animals or humans, these molecules are rapidly metabolized. Thus pharmacokinetics and/or activities of the natural structures and their metabolites may be very different. Novel drug formulations have been postulated in order to improve stability and bioavailability, to minimize side effects, and to facilitate interaction with their domains in target proteins. These pharmacological improvements should lead stilbenes to become effective candidates as anticancer drugs.

Cylophosphamide elicited intracranial hemorrhage via mitochondrial ROS-hif-1α-ATP depleting pathway—preventive trials with folic acid, resveratrol and vitamin E

Hepatic CYP2B metabolizes cyclophosphamide (CP) into acrolein and phosphoramide mustard, which are the ultimate toxic teratogenic compounds.

Insulin catalyzes the curcumin-induced wound healing: an in vitro model for gingival repair

OBJECTIVES

Human gingival fibroblasts (hGFs) play a major role in the maintenance and repair of gingival connective tissue. The mitogen insulin with IGFs etc. synergizes in facilitating wound repair. Although curcumin (CUR) and insulin regulate apoptosis, their impact as a combination on hGF in wound repair remains unknown. Our study consists of: 1) analysis of insulin-mediated mitogenesis on CUR-treated hGF cells, and 2) development of an in vitro model of wound healing.

MATERIALS AND METHODS

Apoptotic rate in CUR-treated hGF cells with and without insulin was observed by AnnexinV/PI staining, nuclear morphological analysis, FACS and DNA fragmentation studies. Using hGF confluent cultures, wounds were mechanically created in vitro and incubated with the ligands for 48 h in 0.2% fetal bovine serum DMEM.

RESULTS

CUR alone showed dose-dependent (1-50 μM) effects on hGF. Insulin (1 μg/ml) supplementation substantially enhanced cell survival through up-regulation of mitogenesis/anti-apoptotic elements.

CONCLUSIONS

The in vitro model for gingival wound healing establishes that insulin significantly enhanced wound filling faster than CUR-treated hGF cells over 48 h. This reinforces the pivotal role of insulin in supporting CUR-mediated wound repair. The findings have significant bearing in metabolic dysfunctions, e.g. diabetes, atherosclerosis, etc., especially under Indian situations.

Resveratrol sensitizes tamoxifen in antiestrogen-resistant breast cancer cells with epithelial-mesenchymal transition features

Tamoxifen resistance remains to be a huge obstacle in the treatment of hormone-dependent breast cancer, and this therefore highlights the dire need to explore the underlying mechanisms. The epithelial-mesenchymal transition (EMT) is a molecular process through which an epithelial cell transfers into a mesenchymal phenotype. Roles of EMT in embryo development, cancer invasion and metastasis have been extensively reported. Herein, we established tamoxifen-resistant MCF-7/TR breast cancer cells and showed that MCF-7/TR cells underwent EMT driven by enhanced endogenous TGF-β/Smad signaling. Ectopic supplement of TGF-β promoted in MCF-7 cells a mesenchymal and resistant phenotype. In parallel, we demonstrated that resveratrol was capable of synergizing with tamoxifen and triggering apoptosis in MCF-7/TR cells. Further Western blot analysis indicated that the chemosensitizing effects of resveratrol were conferred with its modulation on endogenous TGF-β production and Smad phosphorylation. In particular, 50 μM resveratrol had minor effects on MCF-7/TR cell proliferation, but could significantly attenuate endogenous TGF-β production and the Smad pathway, ultimately leading to reversion of EMT. Collectively, our study highlighted distinct roles of EMT in tamoxifen resistance and resveratrol as a potential agent to overcome acquired tamoxifen resistance. The molecular mechanism of resveratrol chemosensitizing effects is, at least in part, TGF-β/Smad-dependent.

Cytotoxic effect of natural trans-resveratrol obtained from elicited Vitis vinifera cell cultures on three cancer cell lines

trans-Resveratrol (trans-R) has been reported to be a potential cancer chemopreventive agent. Although its cytotoxic activity against different cancer cell lines has been tested, its effect on human acute leukemia cell lines has scarcely been investigated, and only a few in vitro studies were performed using human breast epithelial cell lines. Due to its potential value for human health, demand for trans-R has rapidly increased, and new biotechnological strategies to obtain it from natural edible sources have been developed. Thus, grapevine cell cultures represent a reliable system of trans-R production since they biosynthesize trans-R constitutively or in response to elicitation. In addition, there are no studies deepen on the inhibitory effect of trans-R, produced by elicited grapevine cell cultures, on growth of human tumor cell lines. In this work, the effect of trans-R extracted from the culture medium, after elicitation of grapevine cell cultures, was tested on two human acute lymphocytic and monocytic leukemia cell lines, and one human breast cancer cell line. The effect of trans-R on cell proliferation was not only dose- and time-dependent but also cell type-dependent, as seen from the different degrees of susceptibility of cancer cell lines tested. As regards the effect of trans-R on cell cycle distribution, low trans-R concentrations increased cells in the S phase whereas a high trans-R concentration increased G₀/G₁ phase in all cell lines. Perturbation of the cell cycle at low trans-R concentrations did not correlate with the induction of cell death, whereas a high trans-R concentration, cell proliferation decreased as a result of increasing apoptosis in the three cell lines. In leukemia cells, trans-R up-regulated the expression of caspase-3 while trans-R-induced apoptosis in breast cells occur through a caspase-3-independent mechanism mediated by a down-regulation of Bcl-2.

Cell-cycle analysis and micronuclei frequency reveals G0/G1 blockers as weak micronuclei inducers

Micronuclei (MN) formation is generally attributed to error in DNA synthesis or mitosis, which are represented by the S or G(2)/M phase respectively, in the cell-cycle histogram. Interestingly, many of the known anticancer drugs target these cell-cycle phases to elicit cytotoxicity. Here, we attempted to identify whether any correlation exists between the cell-cycle effect and MN induction potential using various treatments. In addition, we tracked down MN in cycling cells to assess its final fate. We treated SiHa cells with various known drugs and correlated their effects on cell-cycle and MN frequency. MN-tracking studies were performed in peripheral mononuclear and siHa cells upon staining with Giemsa and ethidium bromide respectively. We observed MN induction by all the tested drugs irrespective of their basic effect on cell cycle. However, MN induction was more with drugs which interfere with the S or G(2)/M than the G(0)/G(1) phase. Our results indicate G(0)/G(1) blockers to be comparatively safer drugs. Additionally, our results show that expulsion out of cells may be one of the main fates of drug-induced MN.

Polyphenols sensitization potentiates susceptibility of MCF-7 and MDA MB-231 cells to Centchroman

Polyphenols as “sensitizers” together with cytotoxic drugs as “inducers” cooperate to trigger apoptosis in various cancer cells. Hence, their combination having similar mode of mechanism may be a novel approach to enhance the efficacy of inducers. Additionally, this will also enable to achieve the physiological concentrations facilitating significant increase in the activity at concentrations which the compound can individually provide. Here we propose that polyphenols (Resveratrol (RES) and Curcumin (CUR)) pre-treatment may sensitize MCF-7/MDA MB-231 (Human Breast Cancer Cells, HBCCs) to Centchroman (CC, antineoplastic agent). 6 h pre-treated cells with 10 µM RES/CUR and 100 µM RES/30 µM CUR doses, followed by 10 µM CC for 18 h were investigated for Ser-167 ER-phosphorylation, cell cycle arrest, redox homeostasis, stress activated protein kinase (SAPKs: JNK and p38 MAPK) pathways and downstream apoptosis effectors. Low dose RES/CUR enhances the CC action through ROS mediated JNK/p38 as well as mitochondrial pathway in MCF-7 cells. However, RES/CUR sensitization enhanced apoptosis in p53 mutant MDA MB-231 cells without/with involvement of ROS mediated JNK/p38 adjunct to Caspase-9. Contrarily, through high dose sensitization in CC treated cells, the parameters remained unaltered as in polyphenols alone. We conclude that differential sensitization of HBCCs with low dose polyphenol augments apoptotic efficacy of CC. This may offer a novel approach to achieve enhanced action of CC with concomitant reduction of side effects enabling improved management of hormone-dependent breast cancer.

The anticancer effects of resveratrol: modulation of transcription factors

Resveratrol (3, 4', 5-trihydroxystilbene), a naturally occurring phytoalexin readily available in the diet, is reported to possess both chemopreventive and chemotherapeutic activities in several cancers. However, despite the identification of numerous molecular targets, the underlying mechanisms involved in the anticancer activities of resveratrol are not completely understood. Resveratrol is postulated to function as a potential signaling pathway modulator and, as such, is demonstrated to affect a multitude of signal transduction pathways associated with tumorigenesis and/or carcinogenesis; it is likely that this collective activity, rather than just a single effect, may play an important role in the anticancer properties of resveratrol. Since transcription factors control the expression of many genes, the elucidation of molecular targets of resveratrol involved in transcriptional regulation is necessary to better understand how this dietary phytochemical affects chemopreventive and chemotherapeutic processes. As a result, investigators have increasingly searched for and examined possible targets of resveratrol. In this review, we summarize the current knowledge on molecular targets, specifically transcription factors, that contribute to the observed anticancer effects of resveratrol related to 1) inhibition of carcinogenic activation and induction of carcinogen detoxification, 2) induction of growth arrest and apoptosis, and 3) suppression of proinflammatory signaling pathways related to cancer progression.

The role of nutraceuticals in chemoprevention and chemotherapy and their clinical outcomes

The genesis of cancer is often a slow process and the risk of developing cancer increases with age. Altering a diet that includes consumption of beneficial phytochemicals can influence the balance and availability of dietary chemopreventive agents. In chemopreventive approaches, foods containing chemicals that have anticancer properties can be supplemented in diets to prevent precancerous lesions from occurring. This necessitates further understanding of how phytochemicals can potently maintain healthy cells. Fortunately there is a plethora of plant-based phytochemicals although few of them are well studied in terms of their application as cancer chemopreventive and therapeutic agents. In this analysis we will examine phytochemicals that have strong chemopreventive and therapeutic properties in vitro as well as the design and modification of these bioactive compounds for preclinical and clinical applications. The increasing potential of combinational approaches using more than one bioactive dietary compound in chemoprevention or cancer therapy will also be evaluated. Many novel approaches to cancer prevention are on the horizon, several of which are showing great promise in saving lives in a cost-effective manner.

Antiproliferative effect of resveratrol in pancreatic cancer cells

To investigate resveratrol, one of the food derived polyphenols that might be partially responsible for the beneficial effect on cancer, the in vitro antitumor activity of resveratrol against pancreatic cancer cell lines (PANC-1, BxPC-3 and AsPC-1) was examined, together with the mechanisms involved. The effects of resveratrol on the growth inhibition, apoptosis and cell cycle were assayed. The activity of caspases and the expression of Bcl-2, Bcl-xL, XIAP and Bax protein were detected. The results showed that resveratrol inhibited the proliferation of pancreatic cancer cells in a dose- and time-dependent manner. Resveratrol inhibited the cell growth of PANC-1, BxPC-3 and AsPC-1 cells with IC(50) values of 78.3 ± 9.6 μmol/L, 76.1 ± 7.8 μmol/L and 123.1 ± 6.5 μmol/L at 48 h, respectively. Incubation of pancreatic cancer cells with resveratrol resulted in cell apoptosis and cell cycle arrests. Resveratrol induced activation of caspases. Simultaneously, resveratrol regulated the expression of the antiapoptotic proteins Bcl-2, Bcl-xL and XIAP and the proapoptotic protein Bax. PANC-1 and BxPC-3 cells were more chemosensitive to resveratrol than AsPC-1 cells. In conclusion, resveratrol inhibited the proliferation of pancreatic cancer cells by inducing apoptotic cell death. There was different sensitivity to resveratrol in different pancreatic cancer cell lines.

Protection against severe intestinal ischemia/reperfusion injury in rats by intravenous resveratrol

BACKGROUND

Repetitive enteral or intraperitoneal administration of resveratrol at high doses has recently been found to protect the small intestine against acute ischemia/reperfusion (I/R) injury. In the present work, the protective potential of solvent-free continuous intravenous infusions of small amounts of resveratrol was studied in a model of severe intestinal I/R injury.

MATERIALS AND METHODS

Mesenteric ischemia was induced in male Wistar rats (six animals/group) by superior mesenteric artery occlusion (SMAO, 90 min) and reperfusion (120 min) by reopening of the microvascular clamp. Resveratrol (0.056 or 0.28 mg/kg) was continuously perfused into the jugular vein (0.014 or 0.07 mg/kg × h) starting 30 min before SMAO; an SMAO control group and sham groups (no SMAO) receiving either 0.9% NaCl solution or resveratrol (0.28 mg/kg) were included. During the experimental procedure, isotonic saline was given at a systolic blood pressure below 90 mmHg, and several parameters including those of biomonitoring and blood gas analysis were measured. Small intestine injury was assessed macroscopically, from released plasma enzyme activities, from the tissue contents of thiobarbituric acid-reactive substances and hemoglobin, from the tissue myeloperoxidase activity, and histopathologically.

RESULTS

Resveratrol at only 0.056 mg/kg significantly decreased the macroscopic damage score, the tissue myeloperoxidase activity, the hemoglobin content, the histopathologic score, and the plasma glutamate-pyruvate transaminase activity, but it did not improve the systemic and metabolic parameters. Instead, during reperfusion, significantly higher volumes of saline were administered to animals receiving the polyphenol, although resveratrol did not significantly affect any parameters in sham-operated animals.

CONCLUSIONS

Low doses of intravenously administered resveratrol considerably protected the rat small intestine against severe I/R injury, despite some adverse effects on blood pressure under these conditions.

Stability of cyclophosphamide in extemporaneous oral suspensions

BACKGROUND

Cyclophosphamide, an alkylating agent, is widely used for the treatment of many adult and pediatric malignancies. The stability of cyclophosphamide in aqueous- and methylcellulose-based oral suspending vehicles is currently unknown.

OBJECTIVE

To develop and validate a stability-indicating high-performance liquid chromatography (HPLC) method to measure cyclophosphamide concentrations in simple syrup and Ora-Plus, and assess the 56-day chemical stability and physical appearance of cyclophosphamide in these suspensions at both room temperature (22 degrees C) and 4 degrees C.

METHODS

The intravenous formulation of cyclophosphamide was diluted to 20 mg/mL in NaCl 0.9%, compounded 1:1 with either suspending vehicle, and stored in the dark in 3-mL amber polypropylene oral syringes at 4 degrees C and 22 degrees C. Aliquots from each syringe were obtained on days 0, 3, 7, 14, 21, 28, 35, 42, 49, and 56 and assayed using the validated stability-indicating HPLC-UV method. A C18 analytical column was used to separate cyclophosphamide from the internal standard, ifosfamide, with a mobile phase of 21% acetonitrile in 79% sodium phosphate buffer. The suspension was examined for odor change, visually examined under normal fluorescent light for color change, and examined under a light microscope for evidence of microbial growth.

RESULTS

Samples of cyclophosphamide in both simple syrup and Ora-Plus were stable when kept at 4 degrees C for at least 56 days. At room temperature, cyclophosphamide in simple syrup and Ora-Plus had a shelf life of 8 and 3 days, respectively. No changes in color or odor or evidence of microbial growth were observed.

CONCLUSIONS

Cyclophosphamide can be extemporaneously prepared in simple syrup or Ora-Plus and stored for at least 2 months under refrigeration without significant degradation.