Nano, Nano: Tiny Lipid Particles with Big Therapeutic Potential

cell-transfection-viafect-luciferase-assay

Getting DNA or RNA into cells can be a tricky business, and a variety of transfection reagents have been developed over the years to make the process easier. Lipid-based reagents are especially popular because they combine efficient transfection with relatively low toxicity.

When it comes to transfection, it pays to think small. Human cells range in volume from 20–40 µm3 (sperm cells) to as large as 4 million µm3 (mature egg cells, or oocytes). For several decades, transfection reagents have targeted this size range. However, breakthrough research involves leaving the “micro” realm and entering a world that was once the domain only of science fiction: nanotechnology.

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The Pan-Cancer Atlas: “The End of the Beginning”

In April 2018, a series of 27 papers representing the most comprehensive genomic analysis of human cancers to date was published in Cell Press journals.

The collection constitutes the final outputs from the Cancer Genome Atlas (TCGA) project, a collaboration between the National Cancer Institute (NCI) and the National Human Genome Research Institute (NHGRI) involving analysis of over 11,000 tumors representing 33 different cancers. The many research teams involved analyzed tumor DNA, mRNA, miRNA and chromatin, comparing them to matched normal cellular genomes to perform a complete molecular characterization of cancer-specific changes. The results have been presented with much hope that open access to this type of comprehensive analysis will build on recent advances in understanding tumor biology and spur further progress in developing new approaches to treatment. (See this news item for more detail).

The Pan-Cancer Atlas results are collected on a cell.com portal, where they are presented in three collections grouped by topic: Cell of Origin, Oncogenic Processes and Signaling Pathways. Each collection is accompanied by a “Flagship” paper introducing the topic and summarizing the findings. It seems fitting that these findings have been published in #HumanGenomeMonth. This comprehensive analysis of the genomic and metagenomic profiles of tumors illustrates one powerful application of the type of genomic analysis pioneered by the original Human Genome Project, and shows just how much has been made possible since the initial publication of the human genome fifteen years ago.

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The Free Scientific Resource: Evaluating the Accuracy of Wikipedia

Several weeks ago, I came across an article on ScienceNews.org about how Wikipedia is becoming a scientific resource, whether we like it or not. Scientists are reading Wikipedia, the article said, and it’s affecting how they write. The article cited a study by researchers from MIT and Pitt that found statistical evidence of language in peer-reviewed articles being influenced by Wikipedia articles relevant to the topic. They concluded that journal articles referenced in Wikipedia are subsequently cited more than other similar articles, and that on a semantic level, Wikipedia is influencing the language of scientific journal articles at an astounding rate.

I was intrigued by the idea that reading Wikipedia affects how we later write about a subject. When I start writing about a new topic, the first thing I do is head to Wikipedia to gather a basic understanding before I dive into journal articles. I’ll skim through the overview and most relevant subsections, then check out the references to see what I should continue reading. However, the findings of the study imply that even though I don’t directly use information or language from Wikipedia in my work, it’s still subtly influencing how I write. Continue reading “The Free Scientific Resource: Evaluating the Accuracy of Wikipedia”

The Bacteria that are Good for Us

Chains of Streptococci

Salmonella. Streptococcus. Shigella. The most well-known bacteria are those that cause disease. Our relationship with them is one of combat. With good reason, we look for ways to avoid encountering them and to eliminate them when we do meet.

But not all bacteria are bad for us. Of course we have known for years that we are colonized by harmless bacteria, but recently, studies on the human microbiome have revealed many surprising things about these bacterial tenants. Studies are showing that the teeming multitudes of organisms living in and on the human body are not just harmless bystanders, but complex, interrelated communities that can have profound effects on our health.

Three studies published in Science in 2018 add more to the growing body of microbiome surprises, showing that certain gut bacteria are not only good for us, but may even be required for the effectiveness of some anti-cancer immunotherapies.

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Vitamin D: Power in Cancer Prevention?

This and vitamin D should get your attention.
This and vitamin D should get your attention.

Have you ever noticed that after a good long day outdoors, maybe hiking, at the beach or even working in the yard, you feel really strong and healthy, maybe even more relaxed than after an indoor session in front of the telly or computer? Maybe a February trip to someplace sunny like Mexico or the Canary Islands has given you renewed zest for your normal tasks?

While rest and a change of scenery is never a bad thing, time outdoors and in the sunshine might have gained for you something more than rest and relaxation. If it included a little UVB irradiation, your time outdoors may have increased your serum vitamin D level. And though it’s been presumed for years, we now have proof that higher serum vitamin D3 levels correlate with a decreased incidence of certain cancers. Continue reading “Vitamin D: Power in Cancer Prevention?”

Zika Virus: Another RNA Virus Emerges

no mosquito

Zika virus has been in the news recently due to growing concerns about its global spread. If you have never heard of Zika virus before, you are not alone. Although first discovered in the 1940s, Zika has not been the subject of much study as infection is considered rare and the symptoms mild. However, all this has changed in recent months due to the rapid spread of the virus in Latin America, where it has been associated with an increased incidence of microcephaly, a severe birth defect where babies are born with underdeveloped brains. Although the connection of Zika with microcephaly is not yet proven, the circumstantial evidence is strong, leading the World Health Organization to declare the spread of Zika virus an international public health emergency earlier this week.

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Basic Biology Matters

crop image2Every scientific paper is the story of a journey from an initial hypothesis to a final conclusion. It may take months or years and consists of many steps taken carefully one at a time. The experiments are repeated, the controls verified, the negative and positive results analyzed until the story finally makes sense. Sometimes the end of the story confirms the hypothesis, sometimes it is a surprise. A paper published last week in Cell describes a study where a team of researchers investigating one problem in basic biology (how one component of a signaling complex works), found an unexpected and potentially significant application in a different field (cancer research).

The paper, published in the June 6 issue of Cell, describes a previously unknown interaction between two cellular proteins—the transcription factor HIF1A and the cyclin-dependent kinase CDK8—in the regulation of genes associated with cellular survival under low-oxygen conditions. An accompanying press release describes how the discovery of a role for CDK8 in this process may have implications for cancer research, as CDK8 may be a potential target for drugs to combat “hypoxic” tumors. Continue reading “Basic Biology Matters”

Sonnets in DNA

William ShakespeareFor sixty years now, scientists have studied the role of DNA as a vehicle for the storage and transmission of genetic information from generation to generation. We have marveled at the capacity of DNA to store all the information required to describe a human being using only a 4-letter code, and to pack that information into a space the size of the nucleus of a single cell. A letter published last week in Nature exploits this phenomenal storage capacity of DNA to archive a quite different kind of information. Forget CDs, hard drives and chips, the sum of human knowledge can now be stored in synthetic DNA strands. The Nature letter, authored by scientists from the European Bioinformatics Institute in Cambridge, UK, and Agilent Technologies in California, describes a proof-of-concept experiment where synthetic DNA was used to encode Shakespeare’s Sonnets, Martin Luther King’s “I Have a Dream” speech, a picture of the Bioinformatics Institute, and the original Crick and Watson paper on the double-helical nature of DNA. Continue reading “Sonnets in DNA”

My Microbiome Made Me Do It

When I was in school I learned that there were two different kinds of bacteria, the nasty ones (pathogens) that could make you sick and the nice ones (commensals), which simply colonized you and did nothing much except occupy a spot that could otherwise be taken up by a pathogen. Any role for those commensal bacteria in health and disease was assumed to be no more than that of a harmless squatter. In recent years, studies of this benign microbial population (microbiome studies) have begun to reveal many more intriguing details about how they affect our health and wellbeing. Maybe it’s not so surprising that “good” bacteria could be good for our health—but could they actually affect how we behave? A review in Science summarized findings that indicate that this is indeed the case—at least for certain animal populations. Could it be true for humans as well? Could our colonizing organisms actually influence how we feel and what we do?

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Seeing the Potential

neuronal signalingI had never heard of Halorubrum sodomense until a few days ago. It’s name describes it pretty well, it is a salt-tolerant (Halophilic) organism that contains the red-colored photosynthetic pigment archaerhodopsin, and it was originally isolated from the region of Sodom near the Dead Sea. It’s an organism that is well-known only to those with reason to study it. Many of the rest of us will never have cause to say its name, or to even remember it, and may even occasionally wonder why it is studied at all.

Halorubrum sodomense was in the news recently because a genetically engineered form of its rhodopsin was used to create a method that lights up mammalian neurons as they fire. This exciting development was reported in a paper by Kralj et al, published in the Nov 27 issue of Nature Methods. Continue reading “Seeing the Potential”