p21(WAF1) modulates drug-induced apoptosis and cell cycle arrest in B-cell precursor acute lymphoblastic leukemia

Novel delivery system with a dual–trigger release of savory essential oil by mesoporous silica nanospheres and its possible targets in leukemia cancer cells: in vitro study

Introduction

Essential oils (EOs) are complex structures and possess several pharmacological effects. Nanomedicine offers a solution for their major limitations, including poor solubility, volatility, and non–controlled release, preventing their clinical use.

Methods

Here, we developed a novel delivery system by nanoformulations that were prepared by impregnating savory essential oil (SA) into mesoporous silica nanoparticles (MSNs). The nanoformulations were characterized and examined for their anticancer activities on cancer cells (HepG2 liver and HL60 leukemia cells) and MRC5 normal cells. We further tested the mechanisms of action and possible molecular targets against HL60 cells.

Results

The results demonstrated that SA was governed by nanoformulations under the dual–trigger release of pH/glutathione, and it typically fit the Korsmeyer–Peppas kinetic model. The nanoformulations enhanced the anticancer effect against HepG2 cells and HL60 cells compared to SA but were less cytotoxic to MRC5 normal cells and regulated various molecular pathways of apoptosis. Most importantly, new results were obtained on the genetic regulation principle through the high inhibition of long noncoding RNAs (HOTAIR, HULC, CCAT1, and H19) and matrix metalloproteinases (MMP–2 and MMP–9), providing a novel leukemia target.

Conclusions

These results suggest potential impacts for nanoformulations composed of SA with a sustained release pattern controlled by dual–trigger release of pH/GSH that enhanced anticancer cells. This approach may offer a new route for using EOs as new targets for cancers and open the door for deep preclinical investigations.

Co-Delivery System of Curcumin and Colchicine Using Functionalized Mesoporous Silica Nanoparticles Promotes Anticancer and Apoptosis Effects

Purpose: Many natural agents have a high anticancer potential, and their combination may be advantageous for improved anticancer effects. Such agents, however, often are not water soluble and do not efficiently target cancer cells, and the kinetics of their action is poorly controlled. One way to overcome these barriers is to combine natural agents with nanoparticles. Our aim in the current study was to fabricate an anticancer nanoformulation for co-delivery of two natural agents, curcumin (CR) and colchicine (CL), with a core-shell structure. Using cancer cell lines, we compared the anticancer efficacy between the combination and a nanoformulation with CL alone. Methods: For the single-drug nanoformulation, we used phosphonate groups to functionalize mesoporous silica nanoparticles (MSNs) and loaded the MSNs with CL. Additional loading of this nanoformulation with CR achieved the co-delivery format. To create the structure with a core shell, we selected a chitosan−cellulose mixture conjugated with targeting ligands of folic acid for the coating. For evaluating anticancer and apoptosis effects, we assessed changes in important genes and proteins in apoptosis (p53, caspase-3, Bax, Bcl-2) in several cell lines (MCF-7, breast adenocarcinoma; HCT-116, colon carcinoma; HOS, human osteosarcoma; and A-549, non−small cell lung cancer). Results: Nanoformulations were successfully synthesized and contained 10.9 wt.% for the CL single-delivery version and 18.1 wt.% for the CL+CR co-delivery nanoformulation. Anticancer effects depended on treatment, cell line, and concentration. Co-delivery nanoformulations exerted anticancer effects that were significantly superior to those of single delivery or free CL or CR. Anticancer effects by cell line were in the order of HCT-116 > A549 > HOS > MCF-7. The lowest IC50 value was obtained for the nanoformulation consisting of CL and CR coated with a polymeric shell conjugated with FA (equivalent to 4.1 ± 0.05 µg/mL). With dual delivery compared with the free agents, we detected strongly increased p53, caspase-3, and Bax expression, but inhibition of Bcl-2, suggesting promotion of apoptosis. Conclusions: Our findings, although preliminary, indicate that the proposed dual delivery nanoformulation consisting of nanocore: MSNs loaded with CL and CR and coated with a shell of chitosan−cellulose conjugated folic acid exerted strong anticancer and apoptotic effects with potent antitumor activity against HCT-116 colon cells. The effect bested CL alone. Evaluating and confirming the efficacy of co-delivery nanoformulations will require in vivo studies.

Nanomicelles potentiate histone deacetylase inhibitor efficacy in vitro

Background

Amphiphilic block copolymers used as nanomicelle drug carriers can effectively overcome poor drug solubility and specificity issues. Hence, these platforms have a broad applicability in cancer treatment. In this study, Pluronic F127 was used to fabricate nanomicelles containing the histone deacetylase inhibitor SAHA, which has an epigenetic-driven anti-cancer effect in several tumor types. SAHA-loaded nanomicelles were prepared using a thin-film drying method and characterized for size, surface charge, drug content, and drug release properties. Loaded particles were tested for in vitro activity and their effect on cell cycle and markers of cancer progression.

Results

Following detailed particle characterization, cell proliferation experiments demonstrated that SAHA-loaded nanomicelles more effectively inhibited the growth of HeLa and MCF-7 cell lines compared with free drug formulations. The 30 nm SAHA containing nanoparticles were able to release up to 100% of the encapsulated drug over a 72 h time window. Moreover, gene and protein expression analyses suggested that their cytoreductive effect was achieved through the regulation of p21 and p53 expression. SAHA was also shown to up-regulate E-cadherin expression, potentially influencing tumor migration.

Conclusions

This study highlights the opportunity to exploit pluronic-based nanomicelles for the delivery of compounds that regulate epigenetic processes, thus inhibiting cancer development and progression.

Combination of ERK2 inhibitor VX-11e and voreloxin synergistically enhances anti-proliferative and pro-apoptotic effects in leukemia cells

ERK1/2 inhibitors are new promising anticancer drugs. The aim of this study was to investigate the effect of the combination of ERK2 inhibitor VX-11e and voreloxin on MOLM-14, K562, REH and MOLT-4 leukemia cell lines. We found that VX-11e alone and in combination with voreloxin significantly decreased ERK activation in all cell lines tested. To evaluate the interactions of the drugs, cells were treated for 24 h with VX-11e or voreloxin alone and in combination at fixed ratios based on IC₅₀ values. The combinatorial effects of both drugs were synergistic over a wide range of concentrations in MOLM-14, REH and MOLT-4 cell lines. In K562 cells, three effects were found to be additive, one antagonistic and only one synergistic. The results showed that incubation with both VX-11e and voreloxin inhibited the growth of leukemia cells, affected cell cycle and induced apoptosis. Furthermore, the molecular mechanism of these effects might be attributed to an increased expression of p21 and a decreased expression of survivin and NF-κB in all cell lines tested except from K562 cells. In conclusion, combination of VX-11e and voreloxin can exert a synergistic anticancer effect in leukemia cells.

Studying the ShcD and ERK interaction under acute oxidative stress conditions in melanoma cells

The newly identified melanoma-associated adaptor ShcD was found to translocate to the nucleus upon hydrogen peroxide treatment. Therefore, the aim of this study was to identify the ShcD network in melanoma cells under oxidative stress. LC-MS/MS and GFP-trap were performed to study the ShcD phosphorylation status during acute severe oxidative stress. ShcD was found to be phosphorylated at threonine-159 (Thr159) in response to 5 mM H₂O₂ treatment. The GPS 2.1 phosphorylation prediction program predicted that the Thr159Pro motif, housed in the N-terminus of the ShcD-CH2 domain, is a potential phosphorylation site for MAPKs (ERK, JNK or p38). Co-immunoprecipitation experiments revealed that ShcD mainly interacts with ERK in B16 and MM138 melanoma cells under both hydrogen peroxide-untreated and -treated conditions. Moreover, ShcD interacts with both phosphorylated and un-phosphorylated ERK, although the interaction between ShcD and phospho-ERK was primarily observed after H₂O₂ treatment. A MEK inhibitor (U0126) enhanced the interaction between ShcD and unphosphorylated ERK under oxidative stress conditions. Furthermore, Thr159 was mutated to either alanine (A) or glutamic acid (E) to study whether the threonine phosphorylation state influences the ShcD/ERK interaction. Introducing the T159E mutation obliterated the ShcD/ERK interaction. To identify the functional impact of the ShcD/ERK interaction on cell survival signalling under oxidative stress conditions, caspase 3/7 assays and 7AAD cell death assays were used. The ShcD/ERK interaction promoted anti-survival signalling upon exposure to hydrogen peroxide, while U0126 treatment reduced death signalling. Our data also showed that the death signalling initiated by the ShcD/ERK interaction was accompanied by p21 phosphorylation. In summary, these data identified ShcD, via its interaction with ERK, as a proapoptotic protein under oxidative stress conditions.

NDGA-P21, a novel derivative of nordihydroguaiaretic acid, inhibits glioma cell proliferation and stemness

Nordihydroguaiaretic acid (NDGA) and its synthetic chiral analog dl-nordihydroguaiaretic acid (Nordy) show collective benefits in anti-tumor, and defending against viral and bacterial infections. Here, we synthetized a new derivative-NDGA-P21 based on NDGA structure. Regardless of the structural similarity, NDGA-P21 exhibited stronger capability in suppression of glioblastoma (GBM) cell growth as compared to Nordy. Mechanically, NDGA-P21 is able to arrest cell cycle of GBM cells in G0/G1 phase, and to block cell proliferation sequentially. It is important to note that NDGA-P21 is able to impair the stemness of glioma stem-like cells (GSLCs) via measurement of colony formation and sphere formation. Taken together, the novel NDGA-based compound NDGA-P21 exhibits potential therty -20 apeutic implications through inhibiting proliferation of glioma cells and self-renewal capability of GSLCs.

AKT is indispensable for coordinating Par-4/JNK cross talk in p21 downmodulation during ER stress

The double-edged role of p21 to command survival and apoptosis is emerging. The current investigation highlights ER stress-mediated JNK activation that plausibly triggers cell death by attenuating endogenous p21 level. Here, we demonstrated that ER stress activator 3-AWA diminishes the p21 levels in cancer cells by averting the senescent phenotype to commence G2/M arrest. In essence, the deceleration in p21 level occurs through ER stress/JNK/Caspase-3 axis via activation/induction of proapoptotic Par-4 and inhibition of AKT. The molecular dynamics studies identified important interactions, which may be responsible for the AKT inhibition and efficacy of 3-AWA towards AKT binding pocket. Interestingly, the p21 deceleration was rescued by incubating the cells with 3-AWA in the presence of an ER stress inhibitor, Salubrinal. Furthermore, we demonstrated that p21 expression decreases solitarily in Par-4^+/+ MEFs; albeit, ER stress-induced JNK activation was observed in both Par-4^+/+ and Par-4^−/− MEFs. Par-4 knockdown or overexpression studies established that ectopic Par-4 along with ER stress are not sufficient to downregulate p21 in PC-3 cells but are adequate for DU-145 cells and that the ER stress inflicted activation of JNK, inhibition of AKT and Par-4 induction are all crucial to p21 downmodulation by 3-AWA. By using isogenic cell lines, such as HCT-116 p53^+/+ and HCT-116 p53^−/−, we found that deceleration in p21 expression due to ER stress is p53 independent. Moreover, in orthotopic carcinogen-induced rat colorectal carcinoma model, we found that 3-AWA inhibits colorectal tumor growth and formation of colorectal polyps at a tolerable dose, similar to the first-line drug for colorectal cancer-5-fluorouracil.