Apprentice cancer immunologist

We've been long aware about the possible harm that high-fat-diet could do for our cardiovascular system. Taking greasy fries out of our meals is a way to help us stay away from heart disease, high blood pressure and diabetes, but it may sound unusual to associate it to doing any good to our immune system. Recent studies suggested that high fat diet could cause more severe diseases in autoimmune diseases. The study published in Immunity ( Haghikia and Jo¨rg et al. ) studied the role of two types of fatty acids, short-chain and long-chain fatty acid, on autoimmune diseases. Short chain fatty acids (SCFAs) role are solely metabolized by gut bacteria from otherwise indigestible carbohydrates (e.g. dietary fiber); on the other hand, long-chain FAs (LCFAs) come from regular dietary fat. They kept mice that had neural autoimmune disease (autoimmune encephalomyelitis/EAE) with food enriched with SCFAs, LCFAs or control food to compare disease progression. As a result, mice treated with L...

Continuing the huge trend of discovering more into the magical "immune checkpoint blockade" therapy (as the hottest field that shed hope to cancer treatment), more is to be discussed about them. As is designed to battle against body's own mechanisms that suppress immune cells, those drugs as Ipilimumab and Nivolumab potentiate patients' own immune systems so that they are able to do their jobs and to control tumor growth. Despite the exciting efficacy of these drugs in melanoma, one of the puzzles is the different reponsiveness among patients. Two papers just came out about the topic. While  Ipilimumab (CTLA-4 inhibitor) and Nivolumab (PD-1 inhibitor) were individually discussed in each paper, similar correlation of the responsiveness of immune checkpoint blockade therapy with genomic alteration in melanoma patients were found. High mutation loads tend to correlate with a favorable clinical response of both Ipilimumab and Nivolumab. However as suggested in the S...

For one time I was very into studies on skin cancer, especially melanoma. They are among the most responsive cancer types to immunotherapies because they carry distinctive antigens for immune system to recognize (the first thing that drew me into the subject). They are highly-associated with UV light; the association is also determined by individual genetic background. As asian, for example, I never worried too much about being sun-sensitive or getting skin cancer from a little bit too much sun bath. (Sidenote: my previous post touched upon some related mechanisms. ) However, "my whole world"/my skin changed since this past September- I've been constantly experiencing rashes, swell, and flaking on my face. That was really abnormal to me because my skin was never sensitive. For as long as 2 months, I had 4 reactions in total, and each time it got worse! That was how my story began- How I finally figured out my "photo-allergy" to my sunscreen. Stage 1: Im...

As it is summertime now, I must not be the only one who can’t wait to jump into the pool and give myself a tan. Bronzy cheeks and bodies are currently the big trend in the fashion industry. It also seems to be everyone of my friends’ dream and ultimate goal. However, have you noticed the fact that some people can easily get tan s wh en some only get sunburn s ? If you happen to belong to the latter group, stop trying so hard to bathe in more sun, because you are also at higher risk of getting melanoma. Melanoma is a type of skin cancer that develops from melanocytes - the cells that produce pigment in the skin . Melanoma only contributes a small proportion of all skin cancer s but counts for the large majority of skin cancer deaths. In fact, it is highly associated with ultraviolet (UV) radiation, of which most exposure is due to direct sunlight and tanning beds. So before you get ready to dive into the sun, here is something you should know about the science behind the t...

We have been long conceived that cancer cells are formed from developing oncogenic mutations during proliferation. On the other hand, it is very natural to think that normal tissue cells should have no or maybe very few (just to make it not too absolute) mutations. However, the latest Science paper by Martincorena et al . suggests that normal skin tissues do carry oncogenic mutations, in an amount that may be higher than you thought. The group of scientists collected 234 biopsies of normal eyelid skin tissues from 4 individuals and sequenced 74 known cancer genes in them. What they've found is that the mutation rate of these genes in the sequenced skin tissues is actually as high as in many type of cancer tissues! It is comparable to the mutation rates of breast cancer and is only a factor of 10 less than that in a type of skin carcinoma! How do healthy people, including us, have so many mutations in normal skin tissues? The answer is: sunlight. The study looked into specific ...

Immune checkpoint system stands for the inhibitory receptors that appear on our immune cells (and their ligands on normal tissue cells) that work as "immunological brakes". In physiological condition, such mechanism ensures that the functions of immune cells will get buffered and thus will not impair normal cells surrounding them. The best-known inhibitory receptors are Program Death-1 (PD-1) and Cytotoxic-T lymphocyte-associated protein 4 (CTLA-4) that are expressed on most immune cell types. However, when it comes to cancer condition, immune checkpoints can also be hijacked by cancer cells to protect themselves from immune surveillance. Notably, some cancer cells highly express the ligands of these inhibitory receptors. So imagine in optimal condition, a immune cell can recognize a tumor cell, get activated and can eventually kill it. But when cancer cells trigger the inhibitory pathways of immune cells by directly binding to the PD-1 and CTLA-4 receptors on them, can...