If you have ever been one of the unlucky ones waiting for a cancer diagnosis biopsy, or having a friend or a relative undergoing the process, then you must know how the wait is nerve wrecking. The standard procedure is using a biopsy needle to extract some cells of the tissue suspected for cancer, and then waiting for about a week, until the results come out. To make matters worse, results can sometimes be inconclusive or 100% correct.

Fortunately, a group of scientists at Massachusetts General Hospital (MGH) in Boston, were able to develop a new technology, that is much more rapid and almost 100% accurate in the diagnosis process. They developed a small NMR device (detects compounds by the mode of oscillation of their nuclei in a magnetic field) the size of about a coffee cup, and they were also able to synthesize magnetic Nanoparticles, which stick to certain tumor specific proteins. So now all I have to do, is head to the clinic, have the needle biopsy performed and the cells taken. Then they are mixed with the magnetic Nanoparticles and the results are taken from the small NMR device and read using a simple smartphone application.

This technique was used in the first trial on 50 patients, taking less than an hour to diagnose each. Also, as the device can detect 9 tumor associated proteins, combining the results for 4 of these gave accurate results in 48 out of the 50 patients. In another trial, the accuracy was 100% in the 20 patients tested. The conventional tests’ average accuracy is 74-84 %.

This new technology will also cut down on the cost of repeat biopsies, which can be very expensive, and scientists hope it will have many other applications as well, like patient cancer follow-up, through quantitative analysis of the tumor associated proteins. Maybe the biopsy will not be needed in the future and a simple blood test will also do….

Source: Science/AAAS

Tags: cancer, cancer diagnosis, magnetic nanoparticles, NMR, smart phones, tumor associated proteins

The target

Cancer: An abnormal uncontrolled proliferation of cells. The immune system doesn’t show any response, as the cancer cells are just some normal cells, which have gone crazy. That means that they could deceive our immune system, which recognizes them as normal.

The point of weakness

Cancer cells usually express so-called cancer-specific antigens, which are not otherwise expressed by normal cells.

The mission

Using these antigens as a method of differentiation, we have to teach our immune system to wipe out these cells without affecting the innocent normal ones.

How?

Whole cell vaccines: using tumor cells, derived from a patient or many patients or use human tumor cell lines designed in lab. This will elicit the immune response for all the antigens on cancer cells.

OR,

Antigen vaccines: using a specific antigen on the cancer cell through identifying a certain gene, then cloning the gene, which encodes for it.

Advancing

Adjuvants: using chemical substances to enhance T-cell response such as Interleukin-2 “IL2”.

Vector: using viral vectors to deliver the gene of interest to cells, which makes the cancer more visible to the immune system.

Major obstacle

One major obstacle facing cancer vaccines is that the response is not readily measurable. For chemotherapeutic drugs development, the end point is usually progression-free survival, which has shorter-term outcomes. Cancer vaccines are characterized by longer-term outcomes and increased survival rate.

For more information, Read here.

Tags: antigen, antigen vaccine, cancer, cell lines, cloning, interleukin, progression, survival rate, vaccinolgy, viral vector

Despite great advances in cancer therapy, conventional therapies are still implementing drawbacks and dilemmas that drives cancer research to consider other strategies to overcome the drawbacks implicated by conventional cancer therapy. The  cancer treatment using  anticancer agents possesses many adverse events related to bone marrow suppression and death  of other rapidly proliferating cells is resulting from the either of the two following reasons:

• The narrow therapeutic index of anticancer agents that is in many cases hard to adjust with the inter-individual Pharmacokinetic &/or pharmacogenetic variation among  cancer patients.
• The lack of specificity in most of anticancer agents systemically administered where anticancer agents kill both tumor cells and healthy cells.

Both of the above facts driven cancer therapy research in to many different aspects in the hope of optimizing the therapy & providing new techniques to get over the drawbacks of conventional therapy; The pharmacokinetics & /or pharmacogenetics, gene therapy  in addition to the targeting therapy including the nanotherapy.

Professor Mostafa El Sayed  was awarded the 2007 US National Medal of Science for his huge contribution in the field of nanotherapy in cancer  as a molecular targeting approach that overcomes side effects of conventional cancer therapy. The idea lies in two main aspects: The first is molecular targeting & the second is photothermal destruction of malignant cells. The technique encompasses injecting gold nanoparticles conjugated with anti- Epidermal Growth Factor Receptor “anti -EGFR”  monoclonal antibody , where the anti-EGFR is responsible for the the specific targeting which is molecularly based on the fact that epithelial carcinoma cells, particularly over-expresses “EGFR”. Regarding the tumor cidal effect it is mainly dependent on the  photothermal destruction which is the role of the laser beam & gold nanoparticles, where particular nano size of gold makes it able to absorb light in Near Infra Red Region , which is the region where optical penetration is optimal &  scatter laser beam and convert the light energy to thermal energy that is able to damage cell membrane and release the digestive enzymes and hence the death of cancer cells.

Image credit: www.gatech.edu

The choice of the laser light is a matter of  the cancer location , where in case of cancer under the skin,  Near Infra Red “NIR” laser light is recommended for its larger penetration depth. Gold particles are especially used because  they are easily bioconjugated & they served as photoabsorbers due to overlap of absorption band of their specific nanosize with with argon laser beam. The gold nanoparticles are having a silica core and a gold shell & their absorption in the NIR is tuned by adjusting gold layer thickness as well as the size of silica core.

The pioneering success of the technique has been proved effective upon accumulation of Anti-EGFR antibody conjugated gold nanoparticles selectively in carcinoma cells and survival of benign cells as demonstrated by microscopic pictures of both  benign & cancer cells as follows:

Gold nanoparticles are concentrated in cancer cells. “Pic 1”
Image credit: www.gatech.edu

Gold nanoparticles are not retained in benign cells. “Pic 2”
Image credit: www.gatech.edu

References:

• Ivan H. El Sayed, Xiaohua Huang, Mostafa A. El Sayed, ” Selective laser Photo-thermal therapy of epithelial carcinoma  using anti-EGFR antibody conjugated gold nanoparticles”, Cancer Letters 239 (2006) 129-135.
• Erin B. Dickerson, Erick C. Dreaden, Xiaohua Huang, Ivan H. El Sayed,Hunghao Chu, Sujatha Pushpanketh, John F. Mcdonald, Mostafa A. El Sayed, ” Gold nano assiated near-infrared Plasmonic Phototheramal Therapy (PPTT) of squamos cell carcinoma in mice”, Cancer Letters 269 ( 2008) 57- 66.

Tags: adverse events, anticancer, argon laser, bone marrow suppression, cancer, Epithelial Carcinoma, Gene Therapy, laser, Molecular targetting, monoclonal antibody, nanotherapy, narrow therapeutic index, Pharmackinetic, pharmacogenetic, Photo-Thermal Destruction, Professor Mostafa El Sayed