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| Figure 1: Dendritic cells, the initiator in our immune system (1) |
According to a recent article published by The Wistar Institute, this may be the case! The National Cancer Institute estimates that about 20,000 women will be diagnosed with ovarian cancer, with 15,500 women dying by the end of the year (2). As of now,it is hard to detect this type of cancer early on, so scientists are scrambling to understand the system in order to prevent and treat ovarian cancer more efficiently.
In this article titled, "Traitorous Immune Cells Promote Sudden Ovarian Cancer Progression," The Wistar Institute details a study on the effect of dendritic cells on ovarian cancer. Past case studies show that an aggressive form of ovarian cancer may start off as malignant (due to supression suppression from the immune system) and then suddenly turn into metastatic cancer without warning.
"According to" the Tumor Microenvironment and Metastasis Program of Wistar’s Cancer Center, the dendritic cells of the immune system might be the cause of the tumor "escaping" the immune system.
Isn't it ironic that these cells meant to protect our body can also help tumors grow?
Scientists working in the program at have created a model to work on understanding and preventing the growth of such tumors. Jose Conjeo-Carcia, one of the lead scientists said, “You can see where, if one ovary is cancerous, it is almost unrecognizable until an instantaneous moment, when it explodes into exponential growth. The key to this moment, our evidence suggests, is in the phenotypic changes taking place in the dendritic cells that are part of the tumor microenvironment” (2).
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| Figure 2: Dendritic cell signalling pathway (5) |
How exactly do dendritic cells relate to cancer?
In the normal system, dendritic cells are the initiators of the immune response. As depicted in Figure 2, they will actually set off alarms when faced with any threats such as antigens. They then stimulate white blood cells (such as B-cells and T-cells) to fight off these antigens (3).
Conejo-Garcia continued to say, "Interestingly, the tumors themselves are still immunogenic—they could still otherwise elicit an immune response—it is just that the dendritic cells are actively suppressing the involvement of other anti-tumor immune cells; primarily T cells” (2). So instead of necessarily promoting growth of tumor cells, dendritic cells have an inhibitory effect on the activity of those cells that are meant to help fight off the tumor cells.
The TMMP team believe that their findings dispute the theory of cancer immunoediting. Cancer immunoediting is the process the immune system undergoes to control tumor growth. What it draws upon is the idea that T-cell will recognize the cancer antigens and halt their growth and development (4).
So what are the implications of this study?
The findings of the TMMP team show that the dendritic cells actually suppress the activity of the T-cells, so the problem is in the immune system not being able to fight off the tumor cells efficiently after some point in the struggle. Conejo-Garcia and the rest of the team have since been looking into a way to win back dendritic cells after they defect. I think further research needs to be done on the exact time barrier for when the dendritic cells change from being beneficial to our bodies and when they decide to go rogue.
There also isn't a clear reason as to why this happens yet. What Conejo-Garcia said about the tumor cells still being immunogenic after the switch but the dendritic cells just supress other anti-tumor immune cells further proves to me that our immune system isn't fail-proof despite its important function to our sustainability and survival. If the tumor cells themselves aren't changing, but rather our immune system is changing, what elicits that change? If the cancer cells do not necessarily affect the immune system and cause them to suppress other anti-tumor cells, then this must have been caused by a different factor (or factors). There is a possibility that this behavior happens in all dendritic cells at some point when faced with any type of disease or threat to the body. I think it would be great to see if these dendritic cells also have an effect on different types of cancers as it seems that the problem occurs within the immune system that are innate in all of our bodies.
The findings of the TMMP team show that the dendritic cells actually suppress the activity of the T-cells, so the problem is in the immune system not being able to fight off the tumor cells efficiently after some point in the struggle. Conejo-Garcia and the rest of the team have since been looking into a way to win back dendritic cells after they defect. I think further research needs to be done on the exact time barrier for when the dendritic cells change from being beneficial to our bodies and when they decide to go rogue.
There also isn't a clear reason as to why this happens yet. What Conejo-Garcia said about the tumor cells still being immunogenic after the switch but the dendritic cells just supress other anti-tumor immune cells further proves to me that our immune system isn't fail-proof despite its important function to our sustainability and survival. If the tumor cells themselves aren't changing, but rather our immune system is changing, what elicits that change? If the cancer cells do not necessarily affect the immune system and cause them to suppress other anti-tumor cells, then this must have been caused by a different factor (or factors). There is a possibility that this behavior happens in all dendritic cells at some point when faced with any type of disease or threat to the body. I think it would be great to see if these dendritic cells also have an effect on different types of cancers as it seems that the problem occurs within the immune system that are innate in all of our bodies.
