How Tumors Use Meat to Grow: Xeno-Autoantibodies

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We are now finally able to understand how tumors are able to trick our immune system to feed them with inflammation. When we’re born and grow up, we have immune cells that attack everything but us, because the ones that recognized us were eliminated. Cancer cells may be mutated, but they’re still our cells. So, how do they get the immune system’s attention?

Presumably, any B cell that would recognize us was killed off before birth. That’s where xeno-autoantibodies come in. Xeno means foreign, as in xenophobia. Auto come from the Greek autos, meaning self—as in automobile; a self-moving vehicle, no horse required. But, how can something be both xeno and auto, foreign and self?

Though many tumors, like breast cancer, thrive on inflammation, thrive on this low-grade immune-response, the problem for the tumor is that since it originated from normal breast tissue, it doesn’t look foreign to the immune system. So, the tumor isn’t able to evoke the response it needs and wants.

That’s where NeuGc can come in. “Evidence for a human-specific mechanism for diet and antibody-mediated inflammation in carcinoma [cancer] progression.” See, “Neu5Gc incorporation [by the cancer] confers a selective advantage to tumor cells that are best at accumulating Neu5Gc…” By actively accumulating this foreign meat and dairy molecule coming from our diet into the tumor, the cancer may use it to trick our immune system into producing autoimmune antibodies—anti-Neu5GC autoantibodies, which leads to the release of inflammatory compounds that enable the cancer to grow faster.

“[T]he combination of tumor-associated Neu5Gc and [our] circulating anti-Neu5Gc autoantibodies promotes tumor growth, by inducing weak inflammation, causing infiltration of inflammatory cells and [enhancing] angiogenesis [enhanced blood flow to the tumor].” Our own tumors use what we feed on to get what they feed on.

So, as I talked about before, since cancer, in a sense, may be now considered an autoimmune disease, what are the dietary implications—given the fact that most animals produce this tumor promoter?

Well, we don’t make Neu5Gc—at least we haven’t for a few million years—and, neither do plants. So, to undermine our tumor’s sneaky strategy, I guess it comes down to either cannibalism, or a plant-based diet—or both, I guess. “Importantly, these data are congruent with the decreased cancer risk associated with veganism.”

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Images thanks to Pulmonary Pathology via flickr, and Ilmari Karonen via Wikimedia