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The twofold role of autophagy in cancer is often the therapeutic target. Numerous regulatory pathways are shared between autophagy and other molecular processes needed in tumorigenesis, such as translation or survival signaling. Thus, we have assumed that ILK knockdown should promote autophagy, and used together with chloroquine, an autophagy inhibitor, it could generate a better anticancer effect by dysregulation of common signaling pathways. Expression at the protein level was analyzed using Western Blot; siRNA transfection was done for ILK. Analysis of cell signaling pathways was monitored with phospho-specific antibodies. Melanoma cell proliferation was assessed with the crystal violet test, and migration was evaluated by scratch wound healing assays. Autophagy was monitored by the accumulation of its marker, LC3-II. Our data show that ILK knockdown by siRNA suppresses melanoma cell growth by inducing autophagy through AMPK activation, and simultaneously initiates apoptosis. We demonstrated that combinatorial treatment of melanoma cells with CQ and siILK has a stronger antitumor effect than monotherapy with either of these. It generates the synergistic antitumor effects by the decrease of translation of both global and oncogenic proteins synthesis. In our work, we point to the crosstalk between translation and autophagy regulation. [ABSTRACT FROM AUTHOR]

Background: Melanoma cells form monolayers in serum-containing media, however, in serum-free media they form anchorage-independent spheroids. We investigated miRNAs differentially expressed between these culture types and identified those that possibly control the plasticity of melanoma cells., Materials and Methods: The expression of miRNAs in melanoma cells was evaluated with microarrays, and certain miRNAs were validated with real-time PCR. Several bioinformatic tools were used to assess the involvement of identified miRNAs in cancer-related pathways, and to compile the results of mRNA microarray data from the same melanoma cells., Results: A total of 19 miRNAs were differentially expressed between monolayers and spheroids. miRNAs up-regulated in spheroids modulated cell motility and migration, whereas those up-regulated in monolayers suppressed melanogenesis., Conclusion: The present study identified those miRNAs that participate in the regulation of melanoma cell plasticity., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Background: Melanoma is characterized by high resistance to chemotherapy. The aim of this study was to investigate combined effects of doxorubicin and parthenolide on melanoma cells., Materials and Methods: Thiazolyl blue tetrazolium bromide (MTT) assay and flow cytometry were used to evaluate viability. The p53 levels and Poly-ADP ribose polymerase (PARP) cleavage were assessed by western blot. Electrophoretic mobility shift assay (EMSA) and quantitative real-time polymerase chain reaction (qRT-PCR) were used to evaluate changes in nuclear factor-κB (NF-κB) activity and gene expression, respectively., Results: Both drugs reduced the viability of melanoma cells and induced apoptosis. Expression of the ATP-binding cassette sub-family B member-5 (ABCB5) transporter was enhanced by doxorubicin. Doxorubicin induced activity of p53 and NF-κB. Parthenolide markedly reduced the constitutive and doxorubicin-induced NF-κB activity measured as the nuclear NF-κB, and expression of matrix metalloproteinase-9 (MMP9) and it had no effect on p53., Discussion: Doxorubicin and parthenolide affected distinct pathways in melanoma, and parthenolide was capable of combating some pro-survival effects of doxorubicin in the combined treatment. This provides a rationale for in vivo investigation of this drug combination.

The evasion of cancer cells from the induction of cell death pathways results in the resistance of tumor to current treatment modalities. Therefore, the resistance to cell death, one of the hallmarks of cancer, is a major target in the development of new approaches to selectively affect cancer cells. The complex interplay between individual members of Bcl-2 family regulates both cell survival and the mitochondrial pathway of apoptosis by maintaining mitochondrial membrane integrity (anti-apoptotic Bcl-2 subfamily) and by triggering its disruption in response to stress stimuli (Bax-like subfamily). BH3-only proteins, another Bcl-2 subfamily, act either by direct stimulation of pro-apoptotic proteins of the Bax subfamily or by interfering with anti-apoptotic proteins of the Bcl-2 subfamily. Thus, pro-apoptotic BH3 mimetics, thought to function as BH3-only proteins, are expected to improve the effectiveness of cancer treatment. BH3 mimetics could be either natural or synthetic, peptidic or only based on a helical peptide-like scaffold. Experimental and clinical evidence indicates that BH3 mimetics may not be sufficient to cure cancer patients when used as a single agent. BH3 profiling of cancer cells was introduced to better predict the in vivo responsiveness of tumor to BH3 mimetics combined with conventional therapies. In summary, targeting the Bcl-2 proteins is a promising tool with potential to generate new treatment modalities and to complement existing anti-cancer therapies. This review presents the current knowledge on BH3-only proteins and the spectrum of strategies employing BH3 mimetics in preclinical and clinical studies that aim at tumor targeting.

Proteomics is now widely employed in the study of cancer. Many laboratories are applying the rapidly emerging technologies to elucidate the underlying mechanisms associated with cancer development, progression, and severity in addition to developing drugs and identifying patients who will benefit most from molecular targeted compounds. Various proteomic approaches are now available for protein separation and identification, and for characterization of the function and structure of candidate proteins. In spite of significant challenges that still exist, proteomics has rapidly expanded to include the discovery of novel biomarkers for early detection, diagnosis and prognostication (clinical application), and for the identification of novel drug targets (pharmaceutical application). To achieve these goals, several innovative technologies including 2-D-difference gel electrophoresis, SELDI, multidimensional protein identification technology, isotope-coded affinity tag, solid-state and suspension protein array technologies, X-ray crystallography, NMR spectroscopy, and computational methods such as comparative and de novo structure prediction and molecular dynamics simulation have evolved, and are being used in different combinations. This review provides an overview of the field of proteomics and discusses the key proteomic technologies available to researchers. It also describes some of the important challenges and highlights the current pharmaceutical and clinical applications of proteomics in human cancer research., (Copyright © 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)