Mechanistic evaluation of the signaling events regulating curcumin-mediated chemosensitization of breast cancer cells to 5-fluorouracil

Involvement of Prokineticin 2-expressing Neutrophil Infiltration in 5-Fluorouracil-induced Aggravation of Breast Cancer Metastasis to Lung

Adjuvant chemotherapy is used for human breast cancer patients, even after curative surgery of primary tumor, to prevent tumor recurrence primarily as a form of metastasis. However, anticancer drugs can accelerate metastasis in several mouse metastasis models. Hence, we examined the effects of postsurgical administration with 5-fluorouracil (5-FU), doxorubicin, and cyclophosphamide, on lung metastasis process, which developed after the resection of the primary tumor arising from the orthotopic injection of a mouse triple-negative breast cancer cell line, 4T1. Only 5-FU markedly increased the numbers and sizes of lung metastasis foci, with enhanced tumor cell proliferation and angiogenesis as evidenced by increases in Ki67-positive cell numbers and CD31-positive areas, respectively. 5-FU-mediated augmented lung metastasis was associated with increases in intrapulmonary neutrophil numbers and expression of neutrophilic chemokines, Cxcl1 and Cxcl2 in tumor cells, with few effects on intrapulmonary T-cell or macrophage numbers. 5-FU enhanced Cxcl1 and Cxcl2 expression in 4T1 cells in a NFκB-dependent manner. Moreover, the administration of a neutrophil-depleting antibody or a Cxcr2 antagonist, SB225002, significantly attenuated 5-FU-mediated enhanced lung metastasis with depressed neutrophil infiltration. Furthermore, infiltrating neutrophils and 4T1 cells abundantly expressed prokineticin-2 (Prok2) and its receptor, Prokr1, respectively. Finally, the administration of 5-FU after the resection of the primary tumor failed to augment lung metastasis in the mice receiving Prokr1-deleted 4T1 cells. Collectively, 5-FU can enhance lung metastasis by inducing tumor cells to produce Cxcl1 and Cxcl2, which induced the migration of neutrophils expressing Prok2 with a capacity to enhance 4T1 cell proliferation. Mol Cancer Ther; 17(7); 1515-25. ©2018 AACR.

Heteronemin, a marine natural product, sensitizes acute myeloid leukemia cells towards cytarabine chemotherapy by regulating farnesylation of Ras

Cytarabine is a conventionally used chemotherapeutic agent for treating acute myeloid leukemia (AML). However, chemoresistance, toxic side-effects and poor patient survival rates retard the efficacy of its performance. The current study deals with the chemosensitization of AML cells using heteronemin, a marine natural product towards cytarabine chemotherapy. Heteronemin could effectively sensitize HL-60 cells towards sub-toxic concentration of cytarabine resulting in synergistic toxicity as demonstrated by MTT assay and [3H] thymidine incorporation studies, while being safe towards healthy blood cells. Flow cytometry for Annexin-V/PI and immunoblotting for caspase cleavage proved that the combination induces enhancement in apoptosis. Heteronemin being a farnesyl transferase inhibitor (FTI) suppressed cytarabine-induced, farnesyl transferase-mediated activation of Ras, as assessed by Ras pull-down assay. Upon pre-treating cells with a commercial FTI, L-744,832, the synergism was completely lost in the combination, confirming the farnesyl transferase inhibitory activity of heteronemin as assessed by thymidine incorporation assay. Heteronemin effectively down-regulated cytarabine-induced activation of MAPK, AP-1, NF-κB and c-myc, the down-stream targets of Ras signaling, which again validated the role of Ras in regulating the synergism. Hence we believe that the efficacy of cytarabine chemotherapy can be improved to a significant extent by combining sub-toxic concentrations of cytarabine and heteronemin.

Curcumin Analog Pentagamavunon-1 (PGV-1) Sensitizes Widr Cells to 5-Fluorouracil through Inhibition of NF-κB Activation

Cell cycle regulation and the NF-κB pathway in cancer cells are important in mediating resistance to 5-Fluorouracil (5-FU). Pentagamavunon-1 (PGV-1), a curcumin analog, is known to exhibit stronger growth inhibitory effects than curcumin itself in several cancer cells. In this study, we evaluated the potency of PGV-1 in combination with 5-FU in WiDr colon cancer cells. In MTT assays, PGV-1 did not only exhibit stronger growth inhibitory effects than both 5-FU and curcumin, but also enhanced the cytotoxicity of 5-FU. Flow cytometry demonstrated that single treatments with PGV-1 and 5-FU resulted in different effects on cell cycle profiles. PGV-1 induced G2/M arrest while 5-FU caused S-phase arrest at low concentration (1 μM) and G1-phase arrest at high concentration (100 μM). Interestingly, the combination of 5-FU and PGV-1 enhanced cell accumulation in S-phase. Although a single treatment with either 5-FU or PGV-1 increased cyclin D1 at the protein level, the combination treatment resulted in significant suppression. In addition, PGV-1 inhibited activation of NF-κB and suppressed the expression of cyclooxygenase-2, an NF-κB downstream protein. In conclusion, PGV-1 increased the cytotoxic effect of 5-FU on WiDr cells through inhibition of NF-κB activation.

Concentration- Dependent Effects of Curcumin on 5-Fluorouracil Efficacy in Bladder Cancer Cells

Purpose: Curcumin (Cur), a herbal ingredient with anticancer properties, has been shown to inhibit growth of malignant cells in vivo and in vitro. However, studies on combination therapy of Cur with chemotherapeutic drugs have been limited. Here, effects of Cur on the cytotoxicity of 5-Fluorouracil (FU) were investigated with epithelial bladder cancer cells (EJ138) in vitro. Methods: EJ138 cells were treated with 5 and 15 μM of Cur and/ or 100 μM of FU. Cell viability was measured by sulforhodamine B colorimetric assay. The glucose concentration as an index of cell metabolism was evaluated by an enzymatic method. Total oxidant and antioxidant capacities were estimated by the ferrous oxidation-xylenol (FOX1) method and ferric reducing antioxidant power assay (FRAP), respectively. Results: Combination of 5 μM Cur with FU significantly reduced its cytotoxicity in EJ138 cells, while 15 μM Cur caused an opposite increase. Significant increase in glucose concentration at 24 h and decrease in the FRAP value at 48 h incubation was observed in cells treated with FU in combination with Cur. There were no significant changes in total oxidant capacity with the combination therapy. Conclusion: Our findings suggest a crucial role of Cur concentration in regulating chemotherapeutic agent-induced cytotoxicity. Further investigations are needed to understand the precise mechanisms of action of Cur and determine appropriate doses with combination therapy for clinical application against human cancers.

A functional polymorphism in TFF1 promoter is associated with the risk and prognosis of gastric cancer

Trefoil Factor 1 (TFF1, also named pS2), which serves as the gastrointestinal mucosal protector, is known as gastric-specific tumor suppressor gene. However, the genetic variants of TFF1 are still not well studied. In our study, we aim to explore the effects of tagging single nucleotide polymorphisms (tagSNPs) of TFF1 on risk and prognosis of gastric cancer. Seven tagSNPs of TFF1 gene were first analyzed in the discovery set, which was consisted of 753 cases and 950 cancer-free controls. Then, the validation set (940 cases and 1,042 controls) was used for further evaluation. Moreover, we also tested the relation between these tagSNPs and prognosis of gastric cancer (GC). A series of experiments were performed to investigate the underlying mechanisms. We found that rs3761376 AA in the promoter region of TFF1, could reduce the expression of TFF1 by affecting the binding affinity of estrogen receptor 1 (ESR1, ERα), and thereby increased the risk of GC (1.29, 1.08-1.53). Moreover, the rs3761376 AA genotype was also found associated with worse prognosis among patients receiving 5-FU based chemotherapy after surgery (1.71, 1.18-2.48). Further functional assays demonstrated that TFF1 could increase the chemosensitivity of 5-FU by modulating NF-κB targeted genes. These results identified the effect of rs3761376 on TFF1 expression, which accounted for the correlation with susceptibility and prognosis of GC; and this genetic variant may be a potential biomarker to predict the risk and survival of GC.

Pharmacogenetic landscape of DPYD variants in south Asian populations by integration of genome-scale data

AIM

Adverse drug reactions to 5-Fluorouracil(5-FU) is frequent and largely attributable to genetic variations in the DPYD gene, a rate limiting enzyme that clears 5-FU. The study aims at understanding the pharmacogenetic landscape of DPYD variants in south Asian populations.

MATERIALS & METHODS

Systematic analysis of population scale genome wide datasets of over 3000 south Asians was performed. Independent evaluation was performed in a small cohort of patients.

RESULTS

Our analysis revealed significant differences in the the allelic distribution of variants in different ethnicities.

CONCLUSIONS

This is the first and largest genetic map the DPYD variants associated with adverse drug reaction to 5-FU in south Asian population. Our study highlights ethnic differences in allelic frequencies.

The combination of curcumin and 5-fluorouracil in cancer therapy

5-Fluorouracil (5-FU) alone or in combination with other therapeutic drugs has been widely used for clinical treatment of various cancers. However, 5-FU-based chemotherapy has limited anticancer efficacy in clinic due to multidrug resistance and dose-limiting cytotoxicity. Some molecules and genes in cancer cells, such as nuclear factor kappa B, insulin-like growth factor-1 receptor, epidermal growth factor receptor, cyclooxygenase-2, signal transducer and activator of transcription 3, phosphatase and tensin homolog deleted on chromosome ten and Bcl-2 etc. are related to the chemoresistance and sensitivity of cancer cells to 5-FU. The activation of these molecules and genes expressions in cancer cells will be increased or decreased with long-term exposure of 5-FU. Curcumin has been found to be able to negatively regulate these processes. In order to overcome the problems of 5-FU, curcumin has been used to combine with 5-FU in cancer therapy.

Novel Doxorubicin Derivatives: Synthesis and Cytotoxicity Study in 2D and 3D in Vitro Models

Purpose: Multidrug resistance (MDR) of tumors to chemotherapeutics often leads to failure of cancer treatment. The aim of the study was to prepare novel MDR-overcoming chemotherapeutics based on doxorubicin (DOX) derivatives and to evaluate their efficacy in 2D and 3D in vitro models. Methods: To overcome MDR, we synthesized five DOX derivatives, and then obtained non-covalent complexes with human serum albumin (HSA). Drug efficacy was evaluated for two tumor cell lines, namely human breast adenocarcinoma MCF-7 cells and DOX resistant MCF-7/ADR cells. Additionally, MCF-7 cells were entrapped in alginate-oligochitosan microcapsules, and generated tumor spheroids were used as a 3D in vitro model to study cytotoxicity of the DOX derivatives. Results: Due to 3D structure, the tumor spheroids were more resistant to chemotherapy compared to monolayer culture. DOX covalently attached to palmitic acid through hydrazone linkage (DOX-N2H-Palm conjugate) was found to be the most promising derivative. Its accumulation levels within MCF-7/ADR cells was 4- and 10-fold higher than those of native DOX when the conjugate was added to cultivation medium without serum and to medium supplemented with 10% fetal bovine serum, respectively. Non-covalent complex of the conjugate with HSA was found to reduce the IC50 value from 32.9 µM (for free DOX-N2H-Palm) to 16.8 µM (for HSA-DOX-N2H-Palm) after 72 h incubation with MCF-7/ADR cells. Conclusion: Palm-N2H-DOX conjugate was found to be the most promising DOX derivative in this research. The formation of non-covalent complex of Palm-N2H-DOX conjugate with HSA allowed improving its anti-proliferative activity against both MCF-7 and MCF-7/ADR cells.

Folic acid conjugation improves the bioavailability and chemosensitizing efficacy of curcumin-encapsulated PLGA-PEG nanoparticles towards paclitaxel chemotherapy

Nanoencapsulation has emerged as a novel strategy to enhance the pharmacokinetic and therapeutic potential of conventional drugs. Recent studies from our lab have established the efficacy of curcumin in sensitizing cervical cancer cells and breast cancer cells towards paclitaxel and 5-FU chemotherapy respectively. Factors that hinder the clinical use of curcumin as a sensitizer or therapeutic agent include its poor bioavailability and retention time. Earlier reports of improvement in bioavailability and retention of drugs upon nanoencapsulation have motivated us in developing various nanoformulations of curcumin, which were found to exhibit significant enhancement in bioavailability and retention time as assessed by our previous in vitro studies. Among the various formulations tested, curcumin-entrapped in PLGA-PEG nanoparticles conjugated to folic acid (PPF-curcumin) displayed maximum cell death. In the present study, we have demonstrated the efficacy of this formulation in augmenting the bioavailability and retention time of curcumin, in vivo, in Swiss albino mice. Further, the acute and chronic toxicity studies proved that the formulation is pharmacologically safe. We have also evaluated its potential in chemosensitizing cervical cancer cells to paclitaxel and have verified the results using cervical cancer xenograft model in NOD-SCID mice. Folic acid conjugation significantly enhanced the efficacy of curcumin in down-regulating various survival signals induced by paclitaxel in cervical cancer cells and have considerably improved its potential in inhibiting the tumor growth of cervical cancer xenografts. The non-toxic nature coupled with improved chemosensitization potential makes PPF-curcumin a promising candidate formulation for clinical trials.

Autophagic cell death and premature senescence: New mechanism of 5-fluorouracil and sulforaphane synergistic anticancer effect in MDA-MB-231 triple negative breast cancer cell line

In view of the need for new, more effective therapies for the triple negative breast cancer treatment, the aim of the study was to evaluate the anticancer activity and mechanism of action of the sulforaphane and 5-fluorouracil combination in the triple negative breast cancer cell line MDA-MB-231. Changes in the number of live cells after alone and sequential treatment were determined by the MTT test. The Chou and Talaly method was used to identify the type of interaction. Confocal microscopy, flow cytometry, western blot and spectrophotometry were used to examine apoptosis, autophagy and premature senescence. The western blot method was applied to measure the level of enzymes that are crucial for the 5-fluorouracil activity. Sulforaphane and 5-fluorouracil have been shown to interact synergistically in the breast cancerMDA-MB-231 cell line, resulting in a significant reduction of the number of live cells compared to alone treatments. Sulforaphane has decreased the level of thymidylate synthetase, which was also observed in the case of the sequential sulforaphane and 5-fluorouracil treatment. Studies of the interaction mechanism have revealed that sulforaphane and 5-fluorouracil act synergistically in the MDA-MB-231 cells by inducing autophagic cell death and premature senescence.

NOX4-mediated ROS production induces apoptotic cell death via down-regulation of c-FLIP and Mcl-1 expression in combined treatment with thioridazine and curcumin

Thioridazine is known to have anti-tumor effects by inhibiting PI3K/Akt signaling, which is an important signaling pathway in cell survival. However, thioridazine alone does not induce apoptosis in head and neck squamous cell carcinoma (AMC-HN4), human breast carcinoma (MDA-MB231), and human glioma (U87MG) cells. Therefore, we investigated whether combined treatment with thioridazine and curcumin induces apoptosis. Combined treatment with thioridazine and curcumin markedly induced apoptosis in cancer cells without inducing apoptosis in human normal mesangial cells and human normal umbilical vein cells (EA.hy926). We found that combined treatment with thioridazine and curcumin had synergistic effects in AMC-HN4 cells. Among apoptosis-related proteins, thioridazine plus curcumin induced down-regulation of c-FLIP and Mcl-1 expression at the post-translational levels in a proteasome-dependent manner. Augmentation of proteasome activity was related to the up-regulation of proteasome subunit alpha 5 (PSMA5) expression in curcumin plus thioridazine-treated cells. Combined treatment with curcumin and thioridazine produced intracellular ROS in a NOX4-dependent manner, and ROS-mediated activation of Nrf2/ARE signaling played a critical role in the up-regulation of PSMA5 expression. Furthermore, ectopic expression of c-FLIP and Mcl-1 inhibited apoptosis in thioridazine and curcumin-treated cells. Therefore, we demonstrated that thioridazine plus curcumin induces proteasome activity by up-regulating PSMA5 expression via NOX4-mediated ROS production and that down-regulation of c-FLIP and Mcl-1 expression post-translationally is involved in apoptosis.

Histological analysis of anti-cancer drug loaded, targeted Mn:ZnS quantum dots in metastatic lesions of 4T1 challenged mice

5-Fluororaucil (5-FU) as anti-cancer drug was reported to induce thymidine synthase (TS) overexpression and cancer cell resistance. To improve its therapeutic efficacy and selective targeting, here we developed a targeted delivery system mediated by the active ligand-folate receptor chemistry to deliver the 5-FU drug selectively into the tumor microenvironment. The preparation was achieved by exploring chitosan (CS)-biopolymer based system with folic acid (FA)-conjugation. The 5-FU@FACS-Mn:ZnS quantum dots (QDs) based on the histological assessment conducted in the 4T1 challenged mice showed an improved tumor remission in the liver, spleen and lungs. The 5-FU@FACS-Mn:ZnS composite induced anti-proliferative properties in these organs as compared to the free 5-FU drug. Unlike the 5-FU@FACS-Mn:ZnS treated groups which showed some specific morphological changes such as cell shrinkage without obvious presence of adipocytes, the excised section of the tumor in the untreated control group and the free 5-FU drug treated group showed necrotic and degenerated cells; these cells are multifocally distributed in the tumor mass with evidence of widely distributed adipocytes within the tumor mass. These findings suggest that the 5-FU@FACS-Mn:ZnS composite has a superior role during the induction of apoptosis in the 4T1 cells as compared to the free 5-FU drug treated groups. The results of the study therefore suggest that the impregnation of 5-FU anti-cancer drug within the FACS-Mn:ZnS system significantly improves its selective targeting efficacy, in addition to improving the anti-proliferative properties and attenuate possible tumor resistances to the 5-FU drug. The work discusses about the anti-metastatic effects of folic acid-bound 5-Fluororacil loaded Mn:ZnS quantum dots towards 4T1 cell line proliferation in mice based on the histological analysis.

Epigenomics alternations and dynamic transcriptional changes in responses to 5-fluorouracil stimulation reveal mechanisms of acquired drug resistance of colorectal cancer cells

A drug-induced resistant cancer cell is different from its parent cell in transcriptional response to drug treatment. The distinct transcriptional response pattern of a drug-induced resistant cancer cell to drug treatment might be introduced by acquired DNA methylation aberration in the cell exposing to sustained drug stimulation. In this study, we performed both transcriptional and DNA methylation profiles of the HCT-8 wild-type cells (HCT-8/WT) for human colorectal cancer (CRC) and the 5-fluorouracil (5-FU)-induced resistant cells (HCT-8/5-FU) after treatment with 5-FU for 0, 24 and 48 h. Integrated analysis of transcriptional and DNA methylation profiles showed that genes with promoter hypermethylation and concordant expression silencing in the HCT-8/5-FU cells are mainly involved in pathways of pyrimidine metabolism and drug metabolism-cytochrome P450. Transcriptional analysis confirmed that genes with transcriptional differences between a drug-induced resistant cell and its parent cell after drug treatment for a certain time, rather than their primary transcriptional differences, are more likely to be involved in drug resistance. Specifically, transcriptional differences between the drug-induced resistant cells and parental cells after drug treatment for 24 h were significantly consistent with the differentially expressed genes (termed as CRG_5-FU) between the tissues of nonresponders and responders of CRCs to 5-FU-based therapy and the consistence increased after drug treatment for 48 h (binomial test, P-value=1.88E−06). This study reveals a major epigenetic mechanism inducing the HCT-8/WT cells to acquire resistance to 5-FU and suggests an appropriate time interval (24–48 h) of 5-FU exposure for identifying clinically relevant drug resistance signatures from drug-induced resistant cell models.

Multifunctional microspherical magnetic and pH responsive carriers for combination anticancer therapy engineered by droplet-based microfluidics

Drug loaded luminescent porous silicon diatoms and magnetic bacterial nanowires were encapsulated within pH sensitive polymer forming biodegradable microcapsules using droplet-based microfluidics for targeting colorectal cancer.

MicroRNA-302a enhances 5-fluorouracil-induced cell death in human colon cancer cells

New therapeutic strategies are needed for colorectal cancer (CRC) treatment. MicroRNAs are involved in cancer‑pertinent cellular processes, including chemoresistance. As miR‑302a is an embryonic stem cell‑specific microRNA, studies on miR‑302a have focused on its role in human stem cells. Studies analyzing miR‑302 function in cancer are limited. In this study, we used two human colon cancer cell lines, HCT116 and HT29, and evaluated the influence of miR‑302a on 5‑fluorouracil (5‑FU)‑induced cell death and viability inhibition. With bioinformatics tools, we hypothesized that insulin‑like growth factor‑1 receptor (IGF‑1R) is a novel target of miR‑302a, which we confirmed using a luciferase reporter assay and immunoblotting. Then, we designed siRNA against IGF‑1R and found that si‑IGF‑1R resembled the effect of miR‑302a on 5‑FU treatment. Both miR‑302a and si‑IGF‑1R inhibited Akt signaling. In conclusion, miR‑302a targeted IGF‑1R and enhanced 5‑FU‑induced cell death and viability inhibition in human colon cancer cells. Targeting miR‑302a may offer new therapeutic interventions in CRC.

Curcumin in Treating Breast Cancer: A Review

Breast cancer is among the most common malignant tumors. It is the second leading cause of cancer mortality among women in the United States. Curcumin, an active derivative from turmeric, has been reported to have anticancer and chemoprevention effects on breast cancer. Curcumin exerts its anticancer effect through a complicated molecular signaling network, involving proliferation, estrogen receptor (ER), and human epidermal growth factor receptor 2 (HER2) pathways. Experimental evidence has shown that curcumin also regulates apoptosis and cell phase-related genes and microRNA in breast cancer cells. Herein, we review the recent research efforts in understanding the molecular targets and anticancer mechanisms of curcumin in breast cancer.

Tamoxifen-induced cytotoxicity in breast cancer cells is mediated by glucose-regulated protein 78 (GRP78) via AKT (Thr308) regulation

Glucose regulated protein 78 (GRP78) has recently been suggested to be associated with drug resistance in breast cancer patients. However, the precise role of GRP78 in drug resistance and the involved signaling pathways are not clearly understood. In the present study, we show that among a panel of drugs, namely Paclitaxel (TAX), Doxorubicin (DOX), 5-fluorouracil (5-FU), UCN-01 and Tamoxifen (TAM) used, TAM alone up-regulated the expression of GRP78 significantly and induced apoptosis in MCF-7 and MDA-MB-231 cells. Interestingly, inhibition of GRP78 by a specific pharmacological inhibitor, VER-155008 augmented TAM-induced apoptosis, and overexpression of GRP78 rendered the cells resistant to TAM-induced cell death suggesting a role for GRP78 in TAM-induced cytotoxicity. Mechanistically, the expression of phosphorylated AKT as determined by Western blot analyses revealed that TAM selectively upregulated phosphorylation of AKT at Thr308 but not at Ser473, and siRNA silencing of GRP78 resulted in inhibition of AKT phosphorylation at Thr308 but not at Ser473. Further, a GRP78 inhibitor, VER155008 inhibited TAM-induced phosphorylation of GSK3β, a downstream substrate of AKT. These results, thus suggests a role for GRP78 in TAM-induced AKT activation. Additionally, co-localization studies by immunofluorescence, and immunoprecipitation experiments demonstrated a complex formation of AKT and GRP78. Furthermore, in glucose-free medium, the cells were sensitized to TAM-induced cell death that was associated with reduced AKT phosphorylation at Thr308, thus strengthening the association of AKT regulation with drug response. Collectively, our findings identify a role of GRP78 in AKT regulation in response to TAM in breast cancer cells.

Molecular mechanisms underlying chemopreventive potential of curcumin: Current challenges and future perspectives

In recent years, natural compounds have received considerable attention in preventing and curing most dreadful diseases including cancer. The reason behind the use of natural compounds in chemoprevention is associated with fewer numbers of side effects than conventional chemotherapeutics. Curcumin (diferuloylmethane, PubMed CID: 969516), a naturally occurring polyphenol, is derived from turmeric, which is used as a common Indian spice. It governs numerous intracellular targets, including proteins involved in antioxidant response, immune response, apoptosis, cell cycle regulation and tumor progression. A huge mass of available studies strongly supports the use of Curcumin as a chemopreventive drug. However, the main challenge encountered is the low bioavailability of Curcumin. This extensive review covers various therapeutic interactions of Curcumin with its recognized cellular targets involved in cancer treatment, strategies to overcome the bioavailability issue and adverse effects associated with Curcumin consumption.

PAK6 increase chemoresistance and is a prognostic marker for stage II and III colon cancer patients undergoing 5-FU based chemotherapy

p21-Activated kinase 6 (PAK6) has been implicated in radiotherapy and docetaxel resistance. We have further evaluated PAK6 as a predictor of 5-fluorouracil (5-FU) treatment response in colon cancer. Here we report that in colon cancer PAK6 promotes tumor progression and chemoresistance both in vitro and in vivo. In the clinical analysis, PAK6 was overexpressed in 104 of 147 (70.75%) stage II and III patients who received 5-FU based chemotherapy after surgery. Multivariate Cox regression analysis indicated that PAK6 was an independent prognostic factor for overall survival (P < 0.001) and disease-free survival (P < 0.001). Colon cancer cell lines showed increased PAK6 expression upon 5-FU treatment. In PAK6-knockdown cells treated with 5-FU, cell viability and phosphorylation of BAD decreased, and the number of apoptotic cells, levels of cleaved caspase 3 and PARP increased compared to control cells. The opposite was observed in PAK6 overexpressing cells. Short hairpin RNA knockdown of PAK6 blocked cells in G2-M phase. Furthermore, Animal experiments results in vivo are consistent with outcomes in vitro. This study demonstrates that PAK6 is an independent prognostic factor for adjuvant 5-FU-based chemotherapy in patients with stage II and stage III colon cancer.

Apoptotic activity of 5-fluorouracil in breast cancer cells transformed by low doses of ionizing α-particle radiation

Globally, breast cancer in women is the leading cause of cancer death. This fact has generated an interest to obtain insight into breast tumorigenesis and also to develop drugs to control the disease. Ras is a proto-oncogene that is activated as a response to extracellular signals. As a member of the Ras GTPase superfamily, Rho-A is an oncogenic and a critical component of signaling pathways leading to downstream gene regulation. In chemotherapy, apoptosis is the predominant mechanism by which cancer cells die. However, even when the apoptotic machinery remains intact, survival signaling may antagonize the cell death by signals. The aim of this study was to evaluate 5-fluorouracil (5-FU) in cells transformed by low doses of ionizing α-particle radiation, in breast cancer cell lines on these genes, as well as apoptotic activity. We used two cell lines from an in vitro experimental breast cancer model. The MCF-10F and Tumor2 cell lines. MCF-10F was exposed to low doses of high linear energy transfer (LET) α-particles radiation (150 keV/µm). Tumor2, is a malignant and tumorigenic cell line obtained from Alpha5 (60cGy+E/60cGy+E) injected into the nude mice. Results indicated that 5-FU decreased H-ras, Rho-A, p53, Stat1 and increased Bax gene expression in Tumor2 and decreased Rac1, Rho-A, NF-κB and increased Bax and caspase-3 protein expression in Tumor2. 5-FU decreased H-ras, Bcl-xL and NF-κB and increased Bax gene expression. 5-FU decreased Rac1, Rho-A protein expression and increased Bax and caspase-3 protein expression in MDA-MB-231. Flow cytometry indicated 21.5% of cell death in the control MCF-10F and 80% in Tumor2 cell lines. It can be concluded that 5-FU may exert apoptotic activity in breast cancer cells transformed by low doses of ionizing α-particles in vitro regulating genes of Ras family and related to apoptosis such as Bax, Bcl-xL and NF-κB expression.

Resveratrol chemosensitizes HER-2-overexpressing breast cancer cells to docetaxel chemoresistance by inhibiting docetaxel-mediated activation of HER-2-Akt axis

As breast cancer cells often develop chemoresistance, better therapeutic options are in search to circumvent it. Here we demonstrate that human epidermal growth factor receptor-2 (HER-2)-overexpressing breast cancer cells resist docetaxel-induced cytotoxicity by upregulating HER-2 and its activity downstream, through Akt and mitogen-activated protein kinase (MAPK) pathways. We observed that introducing resveratrol as a chemosensitizer in docetaxel chemotherapy blocks upregulation and activation of HER-2 in addition to blocking downstream signaling pathways such as Akt. Resveratrol and docetaxel combination results in the synergistic induction of cell death in HER-2-overexpressing SK-BR-3 cells, whereas introduction of wild-type HER-2 in MDA-MD-231 cells increased the resistance to docetaxel. Dominant-negative HER-2 sensitizes SK-BR-3 cells to docetaxel. Our study identified a new synergistic therapeutic combination that targets HER-2-induced breast cancer resistance and might help to overcome therapeutic resistance during breast cancer therapy. The synergism of docetaxel and resveratrol was maximum in SK-BR-3, which is unique among the cell lines studied, due to its high expression status of HER-2, a receptor known to dictate the signaling environment of breast cancer cells. Docetaxel could further induce HER-2 activity in these cells, which was downregulated on resveratrol treatment. Transfection of DN-HER-2 in SK-BR-3 cells inhibits the synergism as the transfection itself sensitizes these cells to docetaxel, leaving no role for resveratrol, whereas ectopic expression of HER-2 introduces the synergism in MDA-MB-231, the triple-negative cell line, in which the synergism was minimum, attesting the crucial role of HER-2 in suppressing the sensitivity to docetaxel. Single-agent docetaxel induced HER-2-mediated resistance to cell death, which was blocked by resveratrol. Resveratrol also downregulated docetaxel-induced activation of MAPK and Akt, survival signaling pathways downstream of HER-2. In short, this study, for the first time, establishes the role of HER-2–Akt signaling axis in regulating the synergistic effect of docetaxel and resveratrol in breast cancer cells overexpressing HER-2.

Gonadotropin-mediated chemoresistance: Delineation of molecular pathways and targets

Background

Human chorionic gonadotropin (hCG) has essential roles in pregnancy. Reports linking hCG in non-trophoblastic tumors with poor patient prognosis has spurred interest in patho-physiological roles the hormone might play.

Methods

The ability of hCG to prevent tumor cell death and sustain viability in the presence of chemotherapeutic drugs was assessed and potential synergies with TLR ligands explored. hCG-induced up-modulation of genes involved in chemoresistance was documented and targets validated by siRNA knock-down. Whether hCG could drive collaboration between tumor cells and macrophages in the production of IL-6 and consequent chemoresistance was assessed. The effects of concurrent anti-hCG immunization and chemotherapy on the growth of syngeneic murine tumors were evaluated.

Results

hCG maintained basal levels of cytokine secretion by tumor cells exposed to chemotherapeutic drugs, and enhanced viability and proliferation; pre-treatment with hCG also decreased apoptosis, as assessed by Annexin-V binding and the cleavage of caspase 3. While co-incubation with hCG along with several TLR ligands mediated heightened chemo-resistance, TLR-2/6 and TLR-9 ligands increased the phosphorylation of JNK, and TLR-2 and TLR-8 ligands the phosphorylation of ERK in presence of hCG and curcumin, providing evidence of tri-molecular synergy. The hormone increased the transcription and/or expression of molecular intermediates (SURVIVIN, HIF-1α, PARP-1, Bcl-2, c-FLIP, KLK-10, XIAP, c-IAP-1) associated with chemo-resistance and increased levels of stress modulators (PON2, HO-1, HSP27 and NRF-2). siRNAs to SURVIVIN, NRF-2, HO-1 and HIF-1α attenuated hCG-mediated chemo-resistance. hCG-conditioned tumor cell supernatants induced heightened secretion of IL-6 and TNF-α from peripheral blood adherent cells and secreted IL-6 imparted chemo-resistance to naïve tumor cells. Co-administration of curcumin along with an anti-hCG vaccine (hCGβ conjugated to Tetanus Toxoid (TT)) to mice carrying syngeneic tumors resulted in significantly enhanced benefits on animal survival; synergy was demonstrated between anti-hCG antibodies and curcumin in the reduction of tumor cell viability.

Conclusions

The data suggest that hCG, via direct as well as collaborative effects with TLR ligands and accessory cell-secreted cytokines, mediates chemo-resistance in gonadotropin-sensitive tumors and outlines the potential benefits of combination therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1938-x) contains supplementary material, which is available to authorized users.

Pleiotropic Role of Dietary Phytochemicals in Cancer: Emerging Perspectives for Combinational Therapy

Cancer is considered a complicated health issue worldwide. The mean cancer survival through standard therapeutic strategies has not been significantly improved over the past few decades. Hence, alternate remedies are needed to treat or prevent this dreadful disease being explored. Currently, it has been recognized that repeated treatment with chemotherapeutic agents has been largely ineffective due to multidrug resistance and further conventional treatment possesses limited drug accessibility to cancerous tissues, which in turn necessitates a higher dose resulting in increased cytotoxicity. Drug combinations have been practiced to address the problems associated with conventional single drug treatment. Recently, natural dietary agents have attracted much attention in cancer therapy because of their synergistic effects with anticancer drugs against different types of cancer. Natural phytochemicals may execute their anticancer activity through targeting diverse cancer cell signaling pathways, promoting cell cycle arrest and apoptosis, regulating antioxidant status and detoxification. This review focuses mainly on the anticancer efficacy of dietary phytochemicals in combination with standard therapeutic drugs reported from various in vitro and in vivo experimental studies apart from clinical trials. This review adds knowledge to the field of intervention studies using combinational modalities that opens a new window for cancer treatment/chemoprevention.

Recent Advances of Curcumin and its Analogues in Breast Cancer Prevention and Treatment

More than 230,000 diagnosed cases of invasive breast cancer in women was estimated in 2014 and an expected 40,000 deaths attributed to the aggressive carcinoma. An effective approach to diminish the morbidity and mortality of breast cancer is the development of chemopreventive and chemotherapeutic agents. Nutraceuticals have demonstrated their ability to proficiently halt carcinogenesis. The administration of natural compounds able to effectively serve as chemoprevention and chemotherapeutics without causing harm or adverse effects is imperative. Curcumin derived from the rhizome of Curcuma longa L., is a common spice of India, used for centuries because of its medicinal properties. The main component of curcumin possesses a wide range of biological activities; anti-proliferative, anti-inflammatory, and apoptotic characteristics modulated through the inactivation of pathways such as EGK and Akt/mTOR. In addition, curcumin alters the expression of cytokines, transcription factors, and enzymes involved in cell vitality. The in vivo application of curcumin in breast cancer is hindered by its limited bioavailabiity. The synthesis of curcumin analogues and delivery via nanoparticles has demonstrated enhanced bioavailability of curcumin in the malignancy. This review focuses on recent developments in the use of curcumin, curcumin analogues, and novel delivery systems as a preventive and therapeutic method for breast cancer.

Gossypol sensitizes the antitumor activity of 5-FU through down-regulation of thymidylate synthase in human colon carcinoma cells

PURPOSE

5-Fluorouracil (5-FU) is the basic chemotherapeutic agent used to treat colon cancer. However, the sensitivity of colon cancer cells to 5-FU is limited. Gossypol is a polyphenolic extract of cottonseeds. The purpose of this study was to investigate the activities and related mechanism of gossypol alone or in combination with 5-FU against human colon carcinoma cells.

METHODS

The IC50 of gossypol or/and 5-FU in vitro was tested by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and the drug interaction was analyzed using the CalcuSyn method. Cell apoptosis was determined using presidium iodide staining and flow cytometric analysis. Western blotting was used to determine the expression of proteins. Transient transfection method was used to silence protein.

RESULTS

The IC₅₀ at 48 h of gossypol in colon cancer cells was 26.11 ± 1.04 μmol/L in HT-29 cells, 14.11 ± 1.08 μmol/L in HCT116 cells, and 21.83 ± 1.05 μmol/L in RKO cells. When gossypol was combined with 5-FU, a synergistic cytotoxic effect was observed in HT-29 cells, HCT116 cells, and RKO cells compared with treatment with gossypol or 5-FU alone. The Western blotting results indicated that gossypol down-regulated thymidylate synthase (TS) rather than thymidine phosphorylase protein expression. Furthermore, the mTOR/p70S6K1 signaling pathway was inhibited in gossypol-treated colon cancer cells, and consequently, cyclin D1 expression was decreased, suggesting an additional mechanism of the observed antiproliferative synergistic interactions. All the observation was confirmed by silencing TS and inactivating the mTOR/p70S6K1 signaling pathway by rapamycin, both of which increased the chemo-sensitizing efficacy of 5-FU.

CONCLUSIONS

These findings suggest that gossypol-mediated down-regulation of TS, cyclin D1, and the mTOR/p70S6K1 signaling pathways enhances the anti-tumor effect of 5-FU. Ultimately, our data exposed a new action for gossypol as an enhancer of 5-FU-induced cell growth suppression.

The multifaceted role of curcumin in cancer prevention and treatment

Despite significant advances in treatment modalities over the last decade, neither the incidence of the disease nor the mortality due to cancer has altered in the last thirty years. Available anti-cancer drugs exhibit limited efficacy, associated with severe side effects, and are also expensive. Thus identification of pharmacological agents that do not have these disadvantages is required. Curcumin, a polyphenolic compound derived from turmeric (Curcumin longa), is one such agent that has been extensively studied over the last three to four decades for its potential anti-inflammatory and/or anti-cancer effects. Curcumin has been found to suppress initiation, progression, and metastasis of a variety of tumors. These anti-cancer effects are predominantly mediated through its negative regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other oncogenic molecules. It also abrogates proliferation of cancer cells by arresting them at different phases of the cell cycle and/or by inducing their apoptosis. The current review focuses on the diverse molecular targets modulated by curcumin that contribute to its efficacy against various human cancers.

Targeting the NFκB signaling pathways for breast cancer prevention and therapy

The activation of nuclear factor-kappaB (NFκB), a proinflammatory transcription factor, is a commonly observed phenomenon in breast cancer. It facilitates the development of a hormone-independent, invasive, high-grade, and late-stage tumor phenotype. Moreover, the commonly used cancer chemotherapy and radiotherapy approaches activate NFκB, leading to the development of invasive breast cancers that show resistance to chemotherapy, radiotherapy, and endocrine therapy. Inhibition of NFκB results in an increase in the sensitivity of cancer cells to the apoptotic effects of chemotherapeutic agents and radiation and restoring hormone sensitivity, which is correlated with increased disease-free survival in patients with breast cancer. In this review article, we focus on the role of the NFκB signaling pathways in the development and progression of breast cancer and the validity of NFκB as a potential target for breast cancer prevention and therapy. We also discuss the recent findings that NFκB may have tumor suppressing activity in certain cancer types. Finally, this review also covers the state-of-the-art development of NFκB inhibitors for cancer therapy and prevention, the challenges in targeting validation, and pharmacology and toxicology evaluations of these agents from the bench to the bedside.

Natural compounds to overcome cancer chemoresistance: toxicological and clinical issues

INTRODUCTION

Defects in initiating or executing cell death programs are responsible for cancer chemoresistance. The growing understanding of apoptotic programs suggests that compounds simultaneously inhibiting multiple signaling pathways might provide a better therapeutic outcome than that of individual inhibitors.

AREAS COVERED

Natural compounds can modulate different survival pathways, thus enhancing the therapeutic effects of anticancer treatments. This review provides an overview of the preclinical and clinical relevance of chemosensitization, giving special reference to curcumin (CUR) and sulforaphane (SFN) as agents to overcome apoptosis resistance against chemotherapy.

EXPERT OPINION

Even if CUR and SFN are common dietary constituents, they are characterized by several problems still unresolved and hampering their development as anticancer drugs. For a drug to be safe, it must be devoid of toxicity, and some studies conducted to date raises concern about CUR and SFN safety. Moreover, the efficacy of a drug, alone or in association, is usually determined by randomized, placebo-controlled, double-blind clinical trials. No such trials have shown CUR and SFN to be effective so far. Thus, caution should be exercised when suggesting the use of CUR or SFN for cancer-related therapeutic purpose, especially for very early stage of malignancy, or in patients who are undergoing chemotherapy.

Curcumin restores sensitivity to retinoic acid in triple negative breast cancer cells

Background

A major obstacle in the use of retinoid therapy in cancer is the resistance to this agent in tumors. Retinoic acid facilitates the growth of mammary carcinoma cells which express high levels of fatty acid-binding protein 5 (FABP5). This protein delivers retinoic acid to peroxisome proliferator-activated receptor β/δ (PPARβ/δ) that targets genes involved in cell proliferation and survival. One approach to overcome resistance of mammary carcinoma cells to retinoic acid is to target and suppress the FABP5/ PPARβ/δ pathway. The objective of this research was to investigate the effect of curcumin, a polyphenol extract from the plant Curcuma longa, on the FABP5/ PPARβ/δ pathway in retinoic acid resistant triple negative breast cancer cells.

Methods

Cell viability and proliferation of triple negative breast cancer cell lines (MDA-MB-231 and MD-MB-468) treated with curcumin and/or retinoic was analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-bromo-2’-deoxyuridine (BrdU). Expression level of FABP5 and PPARβ/δ in these cells treated with curcumin was examined by Western Blotting analysis and Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Effect of curcumin and retinoic acid on PPARβ/δ target genes, PDK1and VEGF-A were also examined using qRT-PCR. Western Blotting was utilized to examine the protein expression level of the p65 subunit of NF-κB.

Results

Treatment of retinoic acid resistant triple negative breast cancer cells with curcumin sensitized these cells to retinoic acid mediated growth suppression, as well as suppressed incorporation of BrdU. Further studies demonstrated that curcumin showed a marked reduction in the expression level of FABP5 and PPARβ/δ. We provide evidence that curcumin suppresses p65, a transcription factor known to regulate FABP5. The combination of curcumin with retinoic acid suppressed PPARβ/δ target genes, VEGF-A and PDK1.

Conclusions

Curcumin suppresses the expression level of FABP5 and PPARβ/δ in triple negative mammary carcinoma cells. By targeting the FABP5/PPARβ/δ pathway, curcumin prevents the delivery of retinoic acid to PPARβ/δ and suppresses retinoic acid-induced PPARβ/δ target gene, VEGF-A. Our data demonstrates that suppression of the FABP5/ PPARβ/δ pathway by curcumin sensitizes retinoic acid resistant triple negative breast cancer cells to retinoic acid mediated growth suppression.

Chemotherapy-enhanced inflammation may lead to the failure of therapy and metastasis

The lack of therapy and the failure of existing therapy has been a challenge for clinicians in treating various cancers. Doxorubicin, 5-fluorouracil, cisplatin, and paclitaxel are the first-line therapy in various cancers; however, toxicity, resistance, and treatment failure limit their clinical use. Their status leads us to discover and investigate more targeted therapy with more efficacy. In this article, we dissect literature from the patient perspective, the tumor biology perspective, therapy-induced metastasis, and cell data generated in the laboratory.

Curcumin significantly enhances dual PI3K/Akt and mTOR inhibitor NVP-BEZ235-induced apoptosis in human renal carcinoma Caki cells through down-regulation of p53-dependent Bcl-2 expression and inhibition of Mcl-1 protein stability

The PI3K/Akt and mTOR signaling pathways are important for cell survival and growth, and they are highly activated in cancer cells compared with normal cells. Therefore, these signaling pathways are targets for inducing cancer cell death. The dual PI3K/Akt and mTOR inhibitor NVP-BEZ235 completely inhibited both signaling pathways. However, NVP-BEZ235 had no effect on cell death in human renal carcinoma Caki cells. We tested whether combined treatment with natural compounds and NVP-BEZ235 could induce cell death. Among several chemopreventive agents, curcumin, a natural biologically active compound that is extracted from the rhizomes of Curcuma species, markedly induced apoptosis in NVP-BEZ235-treated cells. Co-treatment with curcumin and NVP-BEZ235 led to the down-regulation of Mcl-1 protein expression but not mRNA expression. Ectopic expression of Mcl-1 completely inhibited curcumin plus NVP-NEZ235-induced apoptosis. Furthermore, the down-regulation of Bcl-2 was involved in curcumin plus NVP-BEZ235-induced apoptosis. Curcumin or NVP-BEZ235 alone did not change Bcl-2 mRNA or protein expression, but co-treatment reduced Bcl-2 mRNA and protein expression. Combined treatment with NVP-BEZ235 and curcumin reduced Bcl-2 expression in wild-type p53 HCT116 human colon carcinoma cells but not p53-null HCT116 cells. Moreover, Bcl-2 expression was completely reversed by treatment with pifithrin-α, a p53-specific inhibitor. Ectopic expression of Bcl-2 also inhibited apoptosis in NVP-BE235 plus curcumin-treated cells. In contrast, NVP-BEZ235 combined with curcumin did not have a synergistic effect on normal human skin fibroblasts and normal human mesangial cells. Taken together, combined treatment with NVP-BEZ235 and curcumin induces apoptosis through p53-dependent Bcl-2 mRNA down-regulation at the transcriptional level and Mcl-1 protein down-regulation at the post-transcriptional level.

Gene expression profile of 5-fluorouracil metabolic enzymes in laryngeal cancer cell line: predictive parameters for response to 5-fluorouracil-based chemotherapy

BACKGROUND

5-fluorouracil (5-FU) is an antifolate chemotherapeutic that has become established in many therapeutic regimes, but sensitivity variations and development of resistance are common problems that limit the efficiency of the treatments. Inter-individual variations to 5-FU outcome have been attributed to different expression profiles of genes related to folate metabolism.

METHODS

To elucidate the mechanisms of variations to 5-FU outcome, the authors investigated MTHFR, DHFR, TYMS and SLC19A1 folate genes expression for 5-FU response in laryngeal cancer cell line (Hep-2). Concentrations of 10, 50, and 100 ng/mL of 5-FU chemotherapeutic were added separately in Hep-2 cell line for 24 hours at 37 °C. Cell sensibility was evaluated with fluorescein isothiocyanate (FITC) label Bcl-2 by flow cytometry. The real-time quantitative PCR (qPCR) technique was performed for quantification of gene expression using TaqMan(®) Gene Expression Assay. ANOVA and Bonferroni's post hoc tests were utilized to statistical analysis.

RESULTS

The numbers of viable Hep-2 cells with 10, 50, and 100 ng/mL concentrations of 5-FU chemotherapy were 15.87, 28.3 and 68.9%, respectively. Statistical analysis showed significant association between control group and increased expression for TYMS gene in cells treated with 100 ng/mL/5-FU chemotherapy (P<0.05).

CONCLUSIONS

The authors found association between the highest 5-FU dose chemotherapy and increased expression levels for TYMS folate gene in laryngeal cancer cell line. Although these experiments were performed in vitro, the results suggest that genetic factors are thought to play an important role in drug metabolism and may be useful for predicting treatment outcomes.

Id1-induced IGF-II and its autocrine/endocrine promotion of esophageal cancer progression and chemoresistance--implications for IGF-II and IGF-IR-targeted therapy

PURPOSE

To investigate the autocrine/endocrine role of Id1-induced insulin-like growth factor-II (IGF-II) in esophageal cancer, and evaluate the potential of IGF-II- and IGF-type I receptor (IGF-IR)-targeted therapies.

EXPERIMENTAL DESIGN

Antibody array-based screening was used to identify differentially secreted growth factors from Id1-overexpressing esophageal cancer cells. In vitro and in vivo assays were performed to confirm the induction of IGF-II by Id1, and to study the autocrine and endocrine effects of IGF-II in promoting esophageal cancer progression. Human esophageal cancer tissue microarray was analyzed for overexpression of IGF-II and its correlation with that of Id1 and phosphorylated AKT (p-AKT). The efficacy of intratumorally injected IGF-II antibody and intraperitoneally injected cixutumumab (fully human monoclonal IGF-IR antibody) was evaluated using in vivo tumor xenograft and experimental metastasis models.

RESULTS

Id1 overexpression induced IGF-II secretion, which promoted cancer cell proliferation, survival, and invasion by activating AKT in an autocrine manner. Overexpression of IGF-II was found in 21 of 35 (60%) esophageal cancer tissues and was associated with upregulation of Id1 and p-AKT. IGF-II secreted by Id1-overexpressing esophageal cancer xenograft could instigate the growth of distant esophageal tumors, as well as promote metastasis of circulating cancer cells. Targeting IGF-II and IGF-IR had significant suppressive effects on tumor growth and metastasis in mice. Cixutumumab treatment enhanced the chemosensitivity of tumor xenografts to fluorouracil and cisplatin.

CONCLUSIONS

The Id1-IGF-II-IGF-IR-AKT signaling cascade plays an important role in esophageal cancer progression. Blockade of IGF-II/IGF-IR signaling has therapeutic potential in the management of esophageal cancer.

The formulation and delivery of curcumin with solid lipid nanoparticles for the treatment of on non-small cell lung cancer both in vitro and in vivo

Curcumin was determined to have anticancer potency on several kinds of carcinoma. However, its medical application was limited because of its poor bioavailability, unsatisfying dispersity and rapid metabolism in vivo. In this study, curcumin was delivered by solid lipid nanoparticles (SLN) for lung cancer treatment. The physiochemical characters of SLN-curcumin were detected by HPLC, TEM, Zeta potential analysis and FTIR, and the anticancer efficiency on lung cancer was determined both in vitro and in vivo. SLN-curcumin was synthesized by sol-gel method with the size ranged from 20 to 80 nm. After being loaded in SLN, the IC50 of SLN-curcumin on A549 cells was 4 μM, only 1/20 of plain drug. The plasmid concentration of curcumin was highly increased in mice via i.p. after loaded with SLN. Furthermore, SLN-curcumin enhanced the targeting of curcumin to lung and tumor, which finally increased the inhibition efficiency of curcumin from 19.5% to 69.3%. The Flow Cytometry (FCM) analysis and immuno staining confirmed that the inhibition effect mostly came from apoptosis, but not necrosis. The tumor targeting and profound tumor inhibition effect of SLN-curcumin indicated its medical application on lung cancer treatment, and also provided a novel method for new anticancer agents' development.

Curcuma Contra Cancer? Curcumin and Hodgkin's Lymphoma

Curcumin, a phytochemical isolated from curcuma plants which are used as coloring ingredient for the preparation of curry powder, has several activities which suggest that it might be an interesting drug for the treatment or prevention of cancer. Curcumin targets different pathways which are involved in the malignant phenotype of tumor cells, including the nuclear factor kappa B (NFKB) pathway. This pathway is deregulated in multiple tumor entities, including Hodgkin’s lymphoma (HL). Indeed, curcumin can inhibit growth of HL cell lines and increases the sensitivity of these cells for cisplatin. In this review we summarize curcumin activities with special focus on possible activities against HL cells.