Friday, September 5, 2014

Tweets about cancer stem cells

I've had a long-term interest in research on cancer in general, and cancer stem cells (CSCs) in particular. See, for example, "A stem cell model of human tumor growth: implications for tumor cell clonogenic assays", J Natl Cancer Inst. 1983 Jan;70(1):9-16 [PubMed]. I've been trying to keep up with the current literature about CSCs, and have found the task to be a challenging one.

Effective ways to filter the voluminous academic literature are badly needed. Social media have provided a possible route to this goal. I've been exploring a few such media, and especially Twitter.

I've been a member of Twitter since December 2008. I've posted over 3000 tweets since then. Almost all of them have been about either CSCs or open access (OA).

My tweets about CSCs have included the hashtag #cancerSC. I usually post about 15-25 tweets with this hashtag per month. Previous tweets can be accessed by searching within Twitter for the #cancerSC hashtag. A Google search for the same hashtag will provide access to the same archive of tweets.

As sources of information for recent news and publications about CSCs, I've used the following:

a) Google Alerts, to monitor the web for interesting new content about the keywords "cancer stem".

b) PubMed searches for "cancer stem", with the results sent via PubMed RSS to the RSS reader Feedly. My main focus is on articles published within the last month. PubMed is my main source of relevant information.

c) Other contributors to Twitter, such as @cancerscnews.

These sources (especially PubMed) provide a cornucopia of information about what's new in stem cell research and development. My major challenge has been an editorial one: which aspects of all this information should be selected and tweeted about?

Screening Step 1: A useful screening tool has been the Altmetric Bookmarklet. At present, this Bookmarklet only works on PubMed, the arXiv repository, or pages containing a digital object identifier (DOI).

Using the bookmarklet, I screen the results sent by the PubMed RSS, and select for further examination those articles that have non-zero article level metrics. Whether or not Altmetric has picked up sharing activity around an article, I proceed to Screening Step 2. (For those not familiar with Altmetric.com, it's a start-up that attempts to assess article level metrics or altmetrics).

Screening Step 2: The next screening step is to put the title of each article into Topsy, which allows one to search for tweets that have included this title. If a search using Topsy reveals at least a two tweets about the article, I go the 3rd Screening Step. Sometimes, secondary sources (such as 7thSpace Interactive) are identified in multiple tweets. If so, I again go to Screening Step 3.

Screening Step 3: I'm a supporter of the Open Access movement. So, I next check whether or not the article is freely accessible (no paywalls). If there are no paywalls, I prepare a tweet about the article. If I do run into a paywall, I only prepare a tweet if either the Altmetric, or the results from Topsy, or my own reading of the article, yields a very positive impression. I indicate in the tweet that the article is "not OA".

The targeted viewers for my tweets are anyone interested in current research on CSCs. The tweets are not targeted only at those active in research on CSCs. Hence the somewhat higher priority given to articles that have no paywalls.

Of course. there's no way to avoid some subjectivity in an editorial process of this kind. So, I occasionally ignore the results of the screening process and tweet about articles that I especially liked. And, no doubt, some interesting articles will be missed. The greater the sensitivity and specificity of the screening process, the more likely it is that all of the relevant articles will be found and the irrelevant articles rejected.

For an example of a positive view about tweets, see: Can tweets predict citations? Metrics of social impact based on twitter and correlation with traditional metrics of scientific impact by Gunther Eysenbach (2011).

Examples of positive views about altmetrics are: Altmetrics in the Wild: Using Social Media to Explore Scholarly Impact by Jason Priem, Heather Piwowar & Bradley Hemminger (2012); Value all research products by Heather Piwowar (2013).

I'm aware of criticisms of a screening process which relies heavily on altmetrics and tweets. For examples of such criticisms, see: Twitter buzz about papers does not mean citations later by Richard Van Noorden (2013); Why you should ignore altmetrics and other bibliometric nightmares by David Colquhoun & Andrew Plested (2014); Article-level metrics: An ill-conceived and meretricious idea by Jeffrey Beall (2013).

My own view is that tweets and altmetrics merit further exploration, as indicators of "attention". Of course, one needs to watch out for "gaming" (see: Gaming altmetrics). However, my own examination of tweets and altmetrics related to CSCs has yielded no unequivocal evidence of "gaming". Instead, the tweets I've seen (the coverage of all the altmetrics except for Twitter seems to be low) appear to be the result of authentic-looking attention from real people.

I do not believe that Impact Factors should be regarded as the unquestioned gold standard for indicators used to assess impact (see, for example, Impact Factors: A Broken System by Carly Strasser, 2013). Of course, the gold standard for oneself is one's own opinion upon reading a publication. But, no one can read everything.

An article, How to tame the flood of literature by Elizabeth Gibney in Nature (03 September 2014), provides comments about emerging literature-recommendation engines. I haven't yet used any of these, but they clearly merit attention.

I'd be very grateful for any suggestions about ways to improve the efficiency, sensitivity and specificity of a screening process of the kind outlined in this post.

Wednesday, June 19, 2013

International team submits IND application

On 18 June 2013, there was an announcement at the Princess Margaret Cancer Centre, Toronto. There was also a post on the California stem cell agency blog entitled: Clinical trial to thwart cancer stem cells may begin soon. An excerpt from the post:
The Prince Margaret Center announced the FDA filing, called an Investigational New Drug application (IND), at an event in Toronto recognizing the private donors. A press release about the announcement was picked up at this biotech news site.
The Principal Investigators present for the announcement were Dr. Tak Mak of the Princess Margaret Cancer Centre and Dr. Dennis Slamon of the University of California, Los Angeles (UCLA). What they have done is summarized in another excerpt from the blog post:
By working first to understand the various proteins that drive cells to divide, particularly in cancer, they were able to pinpoint an enzyme, that if blocked, could be the key to keeping cancer in check. They then discovered that this enzyme, called PLK4, can be derailed by a new drug they developed. In the lab, it has been shown to inhibit the growth of breast, ovarian, colorectal, lung, pancreatic and prostate cancer, as well as melanoma.

Information about the human PLK4 protein is available here.

Some background: In June 2008, it was announced that a partnership had been formed between Canada’s Cancer Stem Cell Consortium (CSCC) and the California Institute for Regenerative Medicine (CIRM) for international collaboration to advance cancer stem cell research. An excerpt from the CSCC's announcement:
It is proposed that one of the first initiatives to be launched by the CSCC will be a collaboration between Canadian and Californian scientists through CIRM's upcoming Disease Team Research Awards Competition, which will support multi-disciplinary teams of scientists in pursuit of therapies for specific diseases.The goal is to fund teams that will develop therapy or diagnostics for a particular disease or serious injury.Successful proposals will likely include a description of a path to an Investigational New Drug filing at the end of the four-to-five year grant.

Note the intent to file an IND by the end of the term of the grant.

The results of the Disease Team Research Awards Competition were announced on October 28, 2009. The award to Drs. Slamon and Mak is Grant number DR1-01477. See: Therapeutic Opportunities to Target Tumor Initiating Cells in Solid Tumors. As was stated in a page about Cancer Stem Cells on the website of the Canadian Institutes for Health Research (CIHR), this award was to one of two multi-disciplinary research teams co-led by Canadian and Californian scientists. The other team is co-led by Dr. John Dick of the University Health Network and Dr. Dennis Carson of the University of California, San Diego. My blog post (October 29, 2009) about the awards is entitled: Disease Team awards announced. The post ends with this Disclosure:
I'm a member of the Board of the CSCC, but also a staff member (emeritus) at the University Health Network. So, I was in conflict of interest, and was absent during all of the discussions, by the CSCC Board, about which Canadian applications should be considered for the Disease Team awards.

Wednesday, March 27, 2013

More about Funding for Personalized Medicine Research

A post entitled Funding for Personalized Medicine Research, dated January 31, 2012, provided information about the participation of the Cancer Stem Cell Consortium (CSCC) in the Large-Scale Applied Research Project Competition of Genome Canada, in collaboration with the first phase of the Personalized Medicine Signature Initiative of the Canadian Institutes of Health Research (CIHR).

On March 26, 2013, it was announced that 17 projects will be supported. A list of these project is available (PDF). One of the 17 projects is entitled "Innovative chemogenomic tools to improve outcome in acute myeloid leukemia". The Project leader is Guy Sauvageau of the Institute for Research in Immunology and Cancer (IRIC) at the Université de Montréal. The Project co-leader is Josée Hébert of the Centre de Recherche Hôpital Maisonneuve-Rosemont, Montréal. One of the aims of this project is to develop new models for tracking cancer stem cells that are left behind after a patient is treated.

Tuesday, July 17, 2012

Companies selectively targeting cancer stem cells

Today, I posted this to Twitter: The article is about three companies that are working on treatments designed to target cancer stem cells (CSCs). The companies are OncoMed, Verastem and ImmunoCellular Therapeutics. The article is interesting.

Tuesday, January 31, 2012

Funding for Personalized Medicine Research

The Cancer Stem Cell Consortium (CSCC) is a partner in the 2012 Large-Scale Applied Research Project Competition of Genome Canada, in collaboration with the first phase of the Personalized Medicine Signature Initiative of the Canadian Institutes of Health Research (CIHR). Genome Canada is leading the research competition. An excerpt from Fact Sheet: The Potential of Personalized Medicine:
Funding of $67.5M will come from Genome Canada ($40 million), CIHR ($22.5 million) and the Cancer Stem Cell Consortium ($5 million). Projects will be funded for a maximum of four years. To qualify for funding, researchers must obtain matching funding that at is least equal to that provided through the competition, which will bring the total investment in this research area to close to $140 million. Matching funding is typically derived from provincial, academic, private sector or international sources.

Details about the competition are available here.

Press releases, dated January 31, 2012, about the federal government's support for personalized medicine, are available here and here.

Wednesday, September 14, 2011

Cancer Stem Cell Chronicle

About 3 months ago, as an experiment, I launched the Cancer Stem Cell Chronicle, an online daily newspaper that's based on excerpts from 3 streams of content: 1) Twitter content tagged #cancerSC, 2) Twitter content that includes the keywords "cancer stem", and, 3) content derived from a PubMed RSS feed for the search term "cancer stem".

The experiment looks promising. The CSC Chronicle is beginning to provide a convenient way to monitor recent research news about cancer stem cells. Archives are available. The section headings in the CSC Chronicle aren't very meaningful, and should be ignored.

The CSC Chronicle is hosted by Paper.li.

Thursday, January 6, 2011

A difference between normal and cancer SC biology in the nervous system

Neural Tumor-Initiating Cells Have Distinct Telomere Maintenance and Can be Safely Targeted for Telomerase Inhibition by Pedro Castelo-Branco and 12 co-authors, including Uri Tabori, Clin Cancer Res 2011(Jan 1); 17(1): 111-121 [Full text]. Translational Relevance:
Pediatric neural tumors (brain tumors and neuroblastoma) are the leading cause of morbidity and mortality in childhood cancer. This is due to their ability to recur after minimal disease is achieved. Telomerase is active in most malignant pediatric neural tumors. Therefore, telomerase inhibition may offer an effective treatment option for such patients. Because normal stem cells may require telomerase for continuous self-renewal, this therapy may have devastating effects on normal nervous system development and maintenance.
This study reveals that telomerase activation exists only in the tumor-initiating cancer subpopulation and is critical to sustain their survival and self-renewal potential. Importantly, normal neural or neural crest stem cells do not require telomerase for their self-renewal. Furthermore, as opposed to conventional chemoradiation therapies, telomerase inhibition results in irreversible loss of self-renewal capacity of tumor initiating cells in vitro and in vivo.
These observations uncover a difference between normal and cancer stem cell biology in the nervous system and suggest that telomerase inhibition may offer a specific and safe therapeutic approach for these devastating tumors.
For a commentary on this article, see: Anita B Hjelmeland and Jeremy N Rich, Clin Cancer Res 2011(Jan 1); 17(1): 3-5 (unlike the article, the commentary is not publicly accessible). Abstract:
Telomerase is an important mechanism by which cancers escape replicative senescence. In neural tumors, cancer stem cells express telomerase, suggesting that this may explain their preferential tumorigenesis. Oligonucleotide telomerase targeting selectively disrupts cancer stem cell growth through the induction of differentiation, adding to the armamentarium of anticancer stem cell therapies.