Archivi del mese: novembre 2013

Modelli di cocoltura 3D per studiare crescita, progressione e metastasi del cancro della prostata all’osso

[Wang R, Xu J, Juliette L, Castilleja A, Love J, Sung SY, Zhau HE, Goodwin TJ, Chung LW. Three-dimensional co-culture models to study prostate cancer growth, progression, and metastasis to bone. Semin Cancer Biol. 2005 Oct;15(5):353-64.]

Abstract:

Cancer-stromal interaction results in the co-evolution of both the cancer cells and the surrounding host stromal cells. As a consequence of this interaction, cancer cells acquire increased malignant potential and stromal cells become more inductive. In this review we suggest that cancer-stromal interaction can best be investigated by three-dimensional (3D) co-culture models with the results validated by clinical specimens. We showed that 3D culture promoted bone formation in vitro, and explored for the first time, with the help of the astronauts of the Space Shuttle Columbia, the co-culture of human prostate cancer and bone cells to further understand the interactions between these cells. Continued exploration of cancer growth under 3D conditions will rapidly lead to new discoveries and ultimately to improvements in the treatment of men with hormonal refractory prostate cancer.

Organs-on-chips: modelli di malattie umane e metastasi su chip

[van de Stolpe A, den Toonder J. Workshop meeting report Organs-on-Chips: human disease models. Lab Chip. 2013 Sep 21;13(18):3449-70. doi: 10.1039/c3lc50248a.]

Abstract:

The concept of “Organs-on-Chips” has recently evolved and has been described as 3D (mini-) organs or tissues consisting of multiple and different cell types interacting with each other under closely controlled conditions, grown in a microfluidic chip, and mimicking the complex structures and cellular interactions in and between different cell types and organs in vivo, enabling the real time monitoring of cellular processes. In combination with the emerging iPSC (induced pluripotent stem cell) field this development offers unprecedented opportunities to develop human in vitro models for healthy and diseased organ tissues, enabling the investigation of fundamental mechanisms in disease development, drug toxicity screening, drug target discovery and drug development, and the replacement of animal testing. Capturing the genetic background of the iPSC donor in the organ or disease model carries the promise to move towards “in vitro clinical trials”, reducing costs for drug development and furthering the concept of personalized medicine and companion diagnostics. During the Lorentz workshop (Leiden, September 2012) an international multidisciplinary group of experts discussed the current state of the art, available and emerging technologies, applications and how to proceed in the field. Organ-on-a-chip platform technologies are expected to revolutionize cell biology in general and drug development in particular.

Questo video spiega come sia possibile studiare e capire lo sviluppo del cancro e delle metastasi su chip:

Tumori su chip: l’oncologia incontra la microfluidica

[Wlodkowic D, Cooper JM. Tumors on chips: oncology meets microfluidics. Curr Opin Chem Biol. 2010 Oct;14(5):556-67. doi: 10.1016/j.cbpa.2010.08.016. Epub 2010 Sep 9.]

Abstract:

Despite over 2 million papers published on cancer so far, malignancy still remains a puzzlingly complex disease with overall low survival rates. Expanding our knowledge of the molecular mechanisms of malignancy and of resistance to therapy is crucial in guiding the successful design of anti-cancer drugs and new point-of-care diagnostics. The up-and-coming microfluidic Lab-on-a-Chip (LOC) technology and micro-total analysis systems (μTAS) are arguably the most promising platforms to address the inherent complexity of cellular systems with massive experimental parallelization and 4D analysis on a single cell level. This review discusses the emerging applications of microfluidic technologies and their advantages for cancer biology and experimental oncology. We also summarize the recent advances in miniaturized systems to study cancer cell microenvironment, cancer cytomics, and real-time (4D) pharmacological screening. Microfabricated systems, such as cell microarrays, together with on-chip label-less cytometry, and micro-sorting technologies, are all highlighted with the view of describing their potential applications in pharmacological screening, drug discovery, and clinical oncology. It is envisaged that microfluidic solutions may well represent the platform of choice for next generation in vitro cancer models.

Sistema di coltura cellulare in 3D “AlgiMatrix” come modello in vitro di tumore per studi sul cancro

[Godugu C, Patel AR, Desai U, Andey T, Sams A, Singh M. AlgiMatrix™ based 3D cell culture system as an in-vitro tumor model for anticancer studies. PLoS One. 2013;8(1):e53708. doi: 10.1371/journal.pone.0053708. Epub 2013 Jan 18.]

 

Abstract:

 

BACKGROUND:

Three-dimensional (3D) in-vitro cultures are recognized for recapitulating the physiological microenvironment and exhibiting high concordance with in-vivo conditions. Taking the advantages of 3D culture, we have developed the in-vitro tumor model for anticancer drug screening.

METHODS:

Cancer cells grown in 6 and 96 well AlgiMatrix™ scaffolds resulted in the formation of multicellular spheroids in the size range of 100-300 µm. Spheroids were grown in two weeks in cultures without compromising the growth characteristics. Different marketed anticancer drugs were screened by incubating them for 24 h at 7, 9 and 11 days in 3D cultures and cytotoxicity was measured by AlamarBlue® assay. Effectiveness of anticancer drug treatments were measured based on spheroid number and size distribution. Evaluation of apoptotic and anti-apoptotic markers was done by immunohistochemistry and RT-PCR. The 3D results were compared with the conventional 2D monolayer cultures. Cellular uptake studies for drug (Doxorubicin) and nanoparticle (NLC) were done using spheroids.

RESULTS:

IC(50) values for anticancer drugs were significantly higher in AlgiMatrix™ systems compared to 2D culture models. The cleaved caspase-3 expression was significantly decreased (2.09 and 2.47 folds respectively for 5-Fluorouracil and Camptothecin) in H460 spheroid cultures compared to 2D culture system. The cytotoxicity, spheroid size distribution, immunohistochemistry, RT-PCR and nanoparticle penetration data suggested that in vitro tumor models show higher resistance to anticancer drugs and supporting the fact that 3D culture is a better model for the cytotoxic evaluation of anticancer drugs in vitro.

CONCLUSION:

The results from our studies are useful to develop a high throughput in vitro tumor model to study the effect of various anticancer agents and various molecular pathways affected by the anticancer drugs and formulations.

Metodi in silico nella scoperta di farmaci (drug discovery) e modelli tridimensionali

[Vedani A, Smiesko M. In silico toxicology in drug discovery – concepts based on three-dimensional models. Altern Lab Anim. 2009 Nov;37(5):477-96.]

Abstract:

Animal testing is still compulsory worldwide, for the approval of drugs and chemicals produced in large quantities. Computer-assisted (in silico) technologies are considered to be efficient alternatives to in vivo experiments, and are therefore endorsed by many regulatory agencies, e.g. for use in the European REACH initiative. Advantages of in silico methods include: the possible study of hypothetical compounds; their low cost; and the fact that such virtual experiments are typically based on human data, thus making the question of interspecies transferability obsolete. Since the mid-1990s, computer-based technologies have become an indispensable tool in drug discovery – used primarily to identify small molecules displaying a stereospecific and selective binding to a regulatory macromolecule. Since toxic effects are still responsible for some 20% of the late-stage failures, there is a continuing need for in silico concepts which can be used to estimate a compound’s ADMET (adsorption, distribution, metabolism, elimination, toxicity) properties – in particular, toxicity. The aim of this paper is to provide an insight into computational technologies that allow for the prediction of toxic effects triggered by pharmaceuticals. As most adverse and toxic effects are mediated by unwanted interactions with macromolecules involved in biological regulatory systems, we have focused on methodologies that are based on three-dimensional models of small molecules binding to such entities, and discuss the results at the molecular level.

Affare Biogenic Amines: Claude Reiss risponde sul TheScientist alle accuse di Parvez

Immagine

Nell’articolo Scientists call for retractions del TheScientist, Claude Reiss viene accusato di aver procurato parecchi danni alla rivista Biogenic Amines, cui ha sottoposto più di un paper, da Hasan Parvez, il fondatore della rivista.

Trovate l’articolo intero qui.

Le affermazioni di Parvez sono state allegramente accolte da pro-SA strumentalizzatori, i quali le ripropongono spesso, nel tentativo di diffamare Reiss e il suo operato, senza interrogarsi sulla loro veridicità e senza interessarsi ai retroscena.   

Vi lasciamo dunque alla risposta integrale del diretto interessato, Reiss:

Nell’articolo “Scientists call for retractions”, in cui vengo citato, sono riportate delle dichiarazioni del dottor Parvez che danneggiano la mia reputazione professionale, e pertanto necessitano di essere corrette. Sono entrato a far parte del comitato di redazione di Biogenic Amines su insistente invito del suo capo redattore, il dottor Parvez, ma non ho mai preso parte alle attività editoriali della rivista. Avevo notato che un gran numero di papers pubblicati in questa rivista aveva avuto il dottor Parvez come co-autore. Ho sottoposto 4 papers a questa rivista e sono stato, per ognuno di loro, invitato dal dottor Parvez ad aggiungere il suo nome fra i co-autori, nonostante ciò non fosse legittimo. Per l’ultimo dei 4 papers, che ho sottoposto nel Marzo del 2005, venne accettata una versione rivista a Maggio e le bozze mi vennero rimandate dalla casa editrice (Brill) a Luglio. Quando fui invitato a presentare il lavoro a un meeting alle Hawaii nel mese di agosto, il dottor Parvez insistette per ottenere finanziamenti per poter partecipare anche lui. Mi rifiutai di fornirglieli. Prese provvedimenti immediati, ritirò il paper sostenendo che avessi violato l’accordo sul copyright. Ciò non era ovviamente vero, come confermato personalmente dall’editore (dottor Van der Linde), che si è scusato per l’ira e l’ingiustificato gesto di Parvez. Mi ha inoltre informato che Brill smetterà di pubblicare Biogenic Amines, siccome il numero delle sottoscrizioni alla rivista si sono ridotte a 32. È dunque chiaro che il fatale “danno alla rivista” è stato fatto principalmente dalle “prassi” editoriali del dottor Parvez. Nessuno ha dovuto “costringere (me) a lasciare l’incarico”, siccome la rivista si è eclissata prima. Quanto alle affermazioni sul mio essere “antivivisezionista” del dottor Parvez, potrebbe trovarmi anche una sola mia frase, scritta o detta, nella quale contesto la sperimentazione sui modelli animali basandomi su agomenti filosofici o etici? Il mio unico obiettivo nel contestare con argomenti scientifici il concetto di “modello animale” è quello di evitare, per questioni di salute umana, potenziali effetti avversi. Basta solo considerare il fatto che nei paesi sviluppati la quarta causa di morte è rappresentata dagli effetti collaterali dei farmaci da prescrizione, nonostante ognuno di essi avesse superato con successo migliaia di test su animali.

[Readers respond – The Scientist | March 23, 2006]

Riportiamo il testo completo dell’articolo di risposta pubblicato su TheScientist, visionabile qui, che include anche altre testimonianze:

To the Editor: We were deeply disturbed to hear in your March 2nd article “Scientists call for retractions” that the Research Defence Society (RDS) is now challenging even the publication of papers by scientists who are opposed to animal experimentation. The motivations or beliefs of a paper’s author or authors should not be relevant to its publication — only the quality and relevance of the science. The journal has made clear that the original paper by Dr Bailey was peer-reviewed. Those who have concerns about its scientific qualities should address them in the usual way, and those who don’t like the perceived attitudes of its author should not try to censor a vital scientific debate. Indeed, if the RDS are so confident they are right, why should they even want to do so? Katy Taylor Science Co-ordinator The British Union for the Abolition of Vivisection, 16a Crane Grove London, UK Katy.taylor@buav.org To the Editor: I wish to counter the absurd publicity stunt by Simon Festing and RDS, in the article “Scientists call for retractions” published this month, wherein they ask for retraction of perfectly valid scientific studies published by Jarrod Bailey in Biogenic Amines. I have read both studies, and they are carefully prepared and appropriately referenced discussions validating and supporting non-animal alternatives to animal research in specific areas of medicine. Dr. Festing’s unstated issue is that these papers represent a strong pro-research viewpoint that counters the animal research interests of his employers at the RDS. In attempting to bully the journal’s editors to retract scientifically solid papers for political and economic interests, Dr. Festing shames the commitment to open scientific debate demanded of our shared profession. He and RDS may disagree with Dr. Bailey’s work, but the appropriate response is debate and documentation, not censorship. Unwilling or unable to rebut Dr. Bailey’s scholarship, they have resorted to personal attacks. When I read Dr. Festing’s feeble accusations of extremism against Dr. Bailey, I was reminded that character assassination is the last cowardly refuge of those unable to engage in the debate. One final point regarding Mr. Pincock’s piece. Perhaps the title should be re-thought, because although Dr. Bailey is an acknowledged scientific researcher and academician, Dr. Festing to my knowledge has never done scientific research. He apparently prefers to make his living speaking on behalf of special interests regarding topics outside his personal experience. May I suggest this title: “Special Interests Call for Suppression of Scientific Inquiry?” John J. Pippin Senior Medical and Research Advisor Physicians Committee for Responsible Medicine Dallas, Texas, USAjjpippin@sbcglobal.net To the Editor: The article “Scientists call for retractions,” in which I am quoted, includes statements from Dr. Parvez that harm my professional reputation and are therefore in need of correction. I joined the editorial board of Biogenic Amines at the insistent invitation of its Chief editor, Dr. Parvez, but I took never part in the editorial tasks of the journal. I had observed that a large number of the papers published in this journal had Dr. Parvez as co-author. I submitted 4 papers to this journal, and was, for each of them, invited by Dr. Parvez to add his name as a co-author, although this was not justified. For the last of the 4 papers, which I submitted in March 2005, a revised version was accepted in May and the proofs were sent back to me by the publisher (Brill) in July. As I was invited to present the work at a meeting in Hawaii in August, Dr. Parvez insisted to get funding to attend this meeting also, which I refused to provide. He took immediate action in withdrawing the paper, alleging that I had breached the copyright agreement. This was obviously not the case, as confirmed personally by the publisher (Dr. Van der Linde), who apologized for Dr. Parvez’s angry and unjustified move. He also informed me that Brill will stop publishing Biogenic Amines, since subscriptions had merely dwindled to a total of 32. It is clear that the de
adly “harm to the journal” was mainly made by Dr. Parvez’s editorial “practices”. Nobody had to “force (me) to resign” since the journal had disappeared before. As to Dr. Parvez’s claim that I am an “antivivisectionist,” could he find a single sentence that I said or wrote, challenging animal model experimentation based on ethical or philosophical arguments? My exclusive goal in challenging the “animal model” concept with scientific arguments is to avoid its potential adverse effects in human health issues. Consider only the fact that in developed countries, the fourth cause of death is side effects of prescription drugs, despite each had successfully passed thousands of animal tests. Claude Reiss cjreiss@yahoo.com Links within this article S. Pincock, “Scientists call for retractions,”The Scientist, March 2, 2006. http://www.the-scientist.com/news/display/23184/

La temperatura dei laboratori altera i risultati su animali nella ricerca sul cancro

Questo recentissimo studio pubblicato sul PNAS (Proceedings of the National Academy of Sciences), rivela che la temperatura ambiente all’interno dei laboratori causerebbe stress nei modelli murini utilizzati nella ricerca sul cancro umano, sopprimendone le risposte immunitarie ed influenzando di conseguenza i risultati dei test sperimentali che ”spesso costituiscono la base per lo sviluppo dei farmaci anticancro”.

[Kathleen M. Kokolus, Maegan L. Capitano, Chen-Ting Lee, Jason W.-L. Eng, Jeremy D. Waight, Bonnie L. Hylander, Sandra Sexton, Chi-Chen Hong, Christopher J. Gordon, Scott I. Abrams, and Elizabeth A. Repasky. Baseline tumor growth and immune control in laboratory mice are significantly influenced by subthermoneutral housing temperature. Published online before print November 18, 2013, doi:10.1073/pnas.1304291110 PNAS November 18, 2013]

Full Text: http://www.pnas.org/content/early/2013/11/12/1304291110.full.pdf

Abstract:

We show here that fundamental aspects of antitumor immunity in mice are significantly influenced by ambient housing temperature. Standard housing temperature for laboratory mice in research facilities is mandated to be between 20–26 °C; however, these subthermoneutral temperatures cause mild chronic cold stress, activating thermogenesis to maintain normal body temperature. When stress is alleviated by housing at thermoneutral ambient temperature (30–31 °C), we observe a striking reduction in tumor formation, growth rate and metastasis. This improved control of tumor growth is dependent upon the adaptive immune system. We observe significantly increased numbers of antigen-specific CD8+ T lymphocytes and CD8+ T cells with an activated phenotype in the tumor microenvironment at thermoneutrality. At the same time there is a significant reduction in numbers of immunosuppressive MDSCs and regulatory T lymphocytes. Notably, in temperature preference studies, tumor-bearing mice select a higher ambient temperature than non-tumor-bearing mice, suggesting that tumor-bearing mice experience a greater degree of cold-stress. Overall, our data raise the hypothesis that suppression of antitumor immunity is an outcome of cold stress-induced thermogenesis. Therefore, the common approach of studying immunity against tumors in mice housed only at standard room temperature may be limiting our understanding of the full potential of the antitumor immune response.