Ommoleila Molavi

Sustained release of melatonin: A novel approach in elevating efficacy of tamoxifen in breast cancer treatment.

BACKGROUND Finding advanced anti-cancer agents with selective toxicity in tumor tissues is the goal of anticancer delivery systems. This study investigated potential application of nanostructured lipid carriers (NLCs) in increasing melatonin induced cytotoxicity and apoptosis in MCF-7 breast cancer cells. METHODS Melatonin-loaded NLCs were characterized for particle size, zeta potential, Fourier transforms infrared spectroscopy, differential scanning calorimetry, cellular uptake, and scanning electron microscope (SEM). Anti-proliferative and apoptotic effects of new formulation were evaluated by MTT and flow cytometric assays, respectively. Gene expression of apoptotic markers including survivin, Bcl-2 and Bid were examined by Real time quantitative PCR. RESULTS The optimized formulation of NLCs revealed mean particle size of 71±5nm with nearly narrow size distribution. The formulation exhibited an acceptable stability during four months in terms of size and lack of drug release. The IC50 values for melatonin and tamoxifen were 1.3±0.4mM and 30.7±5.2μM, respectively. Melatonin loaded NLCs decreased percentage of cell proliferation from 55±7.2% to 40±4.1% (p<0.05). Co-treatment of the cells with melatonin loaded nanoparticles and tamoxifen caused two fold increase in the percentage of apoptosis (p<0.05). Evaluation of gene expression profile demonstrated a marked decrease in anti-apoptotic survivin with increase in pro-apoptotic Bid mRNA levels. CONCLUSION Taken together, our results suggest NLC technology as a promising delivery system, which elevates the efficacy of chemotherapeutics in breast cancer cells.

Silibinin sensitizes chemo-resistant breast cancer cells to chemotherapy.

Abstract Context: Multiple drug resistance is the major obstacle to conventional chemotherapy. Silibinin, a nontoxic naturally occurring compound, has anticancer activity and can increase the cytotoxic effects of chemotherapy in various cancer models. Objective: To evaluate the effects of silibinin on enhancing the sensitivity of chemo-resistant human breast cell lines to doxorubicin (DOX) and paclitaxel (PAC). Materials and methods: The cells were treated with silibinin (at 50 to 600 μM concentrations) and/or chemo drugs for 24 and 48 h, then cell viability and changes in oncogenic proteins were determined by MTT assay and Western blotting/RT-PCR, respectively. Flow cytometry was used to study apoptosis in the cells receiving different treatments. The antitumorigenic effects of silibinin (at 200 to 400 μM concentration) were evaluated by mammosphere assay. Results: Silibinin exerted significant growth inhibitory effects with IC50 ranging from 200 to 570 μM in different cell lines. Treatment of DOX-resistant MDA-MB-435 cells with silibinin at 200 μM reduced DOX IC50 from 71 to 10 μg/mL and significantly suppressed the key oncogenic pathways including STAT3, AKT, and ERK in these cells. Interestingly treatment of DOX-resistant MDA-MB-435 cells with silibinin at 400 μM concentration for 48 h induced a 50% decrease in the numbers of colonies as compared with DMSO-treated cells. Treatment of PAC-resistant MCF-7 cells with silibinin at 400 μM concentration generated synergistic effects when it was used in combination with PAC at 250 nM concentration (CI = 0.81). Conclusion: Silibinin sensitizes chemo-resistant cells to chemotherapeutic agents and can be useful in treating breast cancers.

The role of Six1 signaling in paclitaxel-dependent apoptosis in MCF-7 cell line.

The resistance of cancer cells to chemotherapeutic agents represents the main problem in cancer treatment. Despite intensive research, mechanisms of resistance have not yet been fully elucidated. Six1 signaling has an important role in the expansion of progenitor cell populations during early embryogenesis. Six1 gene overexpression has been strongly associated with aggressiveness, invasiveness, and poor prognosis of different cancers. In this study, we investigated the role of Six1 signaling in resistance of MCF-7 breast cancer cells to taxanes. We first established in vitro paclitaxel-resistant MCF-7 breast cancer cells. Morphological modifications in paclitaxel-resistant cells were examined via light microscopic images and fluorescence-activated cell sorting analysis. Applying quantitative real-time polymerase chain reaction, we measured Six1, B-cell lymphoma/leukemia(BCL-2), BAX, and P53 mRNA expression levels in both non-resistant and resistant cells. Resistant cells were developed from the parent MCF-7 cells by applying increasing concentrations of paclitaxel up to 64 nM. The inhibitory concentration 50% value in resistant cells increased from 3.5 ± 0.03 to 511 ± 10.22 nM (p = 0.015). In paclitaxel-resistant cells, there was a significant increase in Six1 and BCL-2 mRNA levels (p = 0.0007) with a marked decrease in pro-apoptotic Bax mRNA expression level (p = 0.03); however, there was no significant change in P53 expression (p = 0.025). Our results suggest that identifying cancer patients with high Six1 expression and then inhibition of Six1 signaling can improve the efficiency of chemotherapeutic agents in the induction of apoptosis.

Silibinin suppresses NPM-ALK, potently induces apoptosis and enhances chemosensitivity in ALK-positive anaplastic large cell lymphoma

Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), an oncogenic fusion protein carrying constitutively active tyrosine kinase, is known to be central to the pathogenesis of ALK-positive anaplastic large cell lymphoma (ALK+ALCL). Here, it is reported that silibinin, a non-toxic naturally-occurring compound, potently suppressed NPM-ALK and effectively inhibited the growth and soft agar colony formation of ALK+ALCL cells. By western blots, it was found that silibinin efficiently suppressed the phosphorylation/activation of NPM-ALK and its key substrates/downstream mediators (including STAT3, MEK/ERK and Akt) in a time- and dose-dependent manner. Correlating with these observations, silibinin suppressed the expression of Bcl-2, survivin and JunB, all of which are found to be upregulated by NPM-ALK and pathogenetically important in ALK+ALCL. Lastly, silibinin augmented the chemosensitivity of ALK+ALCL cells to doxorubicin, particularly the small cell sub-set expressing the transcriptional activity of Sox2, an embryonic stem cell marker. To conclude, the findings suggest that silibinin might be useful in treating ALK+ALCL.

Combined Treatment with Stattic and Docetaxel Alters the Bax/Bcl-2 Gene Expression Ratio in Human Prostate Cancer Cells

Docetaxel, recognized as a stabilizing microtubule agent, is frequently administrated as a first line treatment for prostate cancers. Due to high side effects of monotherapy, however, combinations with novel adjuvants have emerged as an alternative strategy in cancer therapy protocols. Here, we investigated the combined effects of stattic and docetaxel on the DU145 prostate cancer cell line. Cytotoxicity was evaluated by MTT assay. To understand molecular mechanisms of stattic action, apoptotic related genes including Bcl-2, Mcl-1, Survivin and Bax were evaluated by real-time RT-PCR. Alteration in the expression of pro-apoptotic Bax and anti-apoptotic Bcl-2 genes and Bax/Bcl-2 ratio were investigated via the 2ΔΔCT method. The IC50 values for docetaxel and stattic were 3.7 ± 0.9 nM and 4.6±0.8 µM, respectively. Evaluation of key gene expression levels revealed a noticeable decrease in antiapoptotic Bcl-2 and Mcl-1 along with an increase in pro-apoptotic Bax mRNA levels (p<0.05). Our results suggest that combination of a STAT3 inhibitor with doctaxel can be considered as a potent strategy for induction of apoptosis via increasing Bax mRNA expression.

Six family of homeobox genes and related mechanisms in tumorigenesis protocols.

In recent years, the homeobox gene superfamily has been introduced as a master regulator in downstream target genes related to cell development and proliferation. An indispensable role of this family involved in organogenesis development has been widely demonstrated since expression of Six family led to a distinct increase in development of various organs. These functions of Six family genes are primarily based on structure as well as regulatory role in response to external or internal stimuli. In addition to these roles, mutation or aberrant expression of Six family plays a fundamental role in initiation of carcinogenesis, a multistep process including transformation, proliferation, angiogenesis, migration, and metastasis. This suggests that the Six superfamily members can be considered as novel target molecules to inhibit tumor growth and progression. This review focuses on the structure, function, and mechanisms of the Six family in cancer processes and possible strategies to apply these family members for diagnostic, prognostic, and therapeutic purposes.

Synthesis and characterization of novel P(HEMA-LA-MADQUAT) micelles for co-delivery of methotrexate and Chrysin in combination cancer chemotherapy

Abstract A Novel poly [2-hydroxyethyl methacrylate-Lactide-dimethylaminoethyl methacrylate quaternary ammonium alkyl halide] [P(HEMA-LA-MADQUAT)] copolymer was synthesized through combination of ring opening polymerization (ROP) and ‘free’ radical initiated polymerization methods. This newly developed copolymer was fully characterized by FT-IR, 1HNMR and 13CNMR spectroscopy. Micellization of the copolymer was performed by dialysis membrane method and obtained micelles were characterized by FESEM, dynamic light scattering (DLS), zeta potential (ξ), and critical micelle concentration (CMC) measurements. This copolymer was developed with the aim of co-delivering two different anticancer drugs: methotrexate (MTX) and chrysin. In vitro cytotoxicity effect of MTX@Chrysin-loaded P(HEMA-LA-MADQUAT) was also studied through assessing the survival rate of breast cancer cell line (MCF-7) and DAPI staining assays. Cationic micelle (and surface charge of + 7.6) with spherical morphology and an average diameter of 55 nm and CMC of 0.023 gL−1 was successfully obtained. Micelles showed the drug loaded capacity around 87.6 and 86.5% for MTX and Chrysin, respectively. The cytotoxicity assay of a drug-free nanocarrier on MCF-7 cell lines indicated that this developed micelles were suitable nanocarriers for anticancer drugs. Furthermore, the MTX@Chrysin-loaded micelle had more efficient anticancer performance than free dual anticancer drugs (MTX @ chrysin), confirmed by MTT assay and DAPI stainingmethods. Therefore, we envision that this recently developed novel micelle can enhance the efficacy of chemotherapeutic agents, MTX and Chrysin, combination chemotherapy and has the potential to be used as an anticancer drug delivery system for in vivo studies. Therefore, this recently developed novel micelle can enhance the efficacy of chemotherapeutic agents, MTX and Chrysin, combination chemotherapy and has the potential to be used as an anticancer drug delivery system for in vivo studies.

CDK9 regulates apoptosis of myoblast cells by modulation of microRNA-1 expression†

Cdk9 is the catalytic core of the positive transcription elongation factor b (P‐TEFb) and regulates transcriptional elongation factors by phosphorylation of RNA pol II. Apart from its role on myogenic gene expression, Cdk9 regulation of muscle‐specific microRNAs in the early stage of cardiomyogenesis is poorly understood. Here we demonstrate that Cdk9 not only regulates myogenic transcription factors, but also controls muscle‐specific microRNAs. During cardiac differentiation of mouse embryonic stem cells, high Cdk9 expression preceded up‐regulation of miR‐1. To investigate potential regulatory roles of Cdk9 on cardiac microRNAs and myogenesis genes, we overexpressed Cdk9 in myoblast C2C12 cells, which resulted in significant induction of miR‐1 and miR‐206, while miR‐133 was downregulated. Moreover, expression levels of MyoD and Srf, key regulators of myogenesis, also increased in cells with overexpression of Cdk9. We further observed Cdk9‐mediated apoptosis in C2C12 cells corresponding to induction of miR‐1 expression levels. Thus, Cdk9 plays a complex role in myocyte progenitor differentiation and apoptosis by regulating myogenic protein and muscle‐specific microRNA expression. J. Cell. Biochem. 119: 547–554, 2018.