What is the method by which cancer tumors intercept nutrients from blood vessels and grow and spread to the whole body?

ByPolygon Medical Animation

Although the theory that "cancer cells build pipelines by themselves and incorporate nutrients and oxygen from the blood" had caused a major controversy since being announced in 1999, it has not settled to the present It was. However, new clinical trials have started and attention is drawn as there is a possibility that a new approach to cancer treatment may be born.

Tumors have found a bloody new way to grow and spread | Science | AAAS
http://www.sciencemag.org/news/2016/06/tumors-have-found-bloody-new-way-grow-and-spread

A new method by which cancer cells can intercept nutrients and oxygen from blood in 1999 was reported by a team of professors such as Marie Hendricks, cancer biology at the Iowa Cancer Center and caused a major controversy.

Cancer tumor is a blood vessel to incorporate nutrition and oxygenEndothelial cellsAs a pipeline for its own nutrition supply, which isAngiogenesis of malignant tumorsIt is called.

Professors Hendriks et al. Claimed to be different from angiogenesis, what is called "simulated angiogenesis". This is a phenomenon that cancer tumor "creates" a new supply pipeline to supply nutrition to itself. At that time, Professor Hendriks strongly insisted that it confirmed that a small circulation system was produced by the tumor, Professor Donald McDonald's of the University of California said, "The research team observed the overlapping of connective tissues, blood It is not a tube that carries the ball, "he refuted that the team misread the data.

The upper part of the figure below shows angiogenesis by malignant tumor and the lower part shows simulated angiogenesis. While angiogenesis induces blood vessels to grow towards itself, you can see that pseudo-angiogenesis creates a new pipeline on its own.


Angiogenesis of malignant tumors was asserted by Professor Judah Falkman of Harvard University in the 1970s. Normally, "angiogenesis" in which new blood vessels are attracted to cells when injury is healed or during endometrium during menstruation usually occurs. However, cancer cells release a large amount of vascular endothelial growth factor, divide blood vessels collected around themselves at an inevitable speed, and deliver oxygen and nutrients to themselves. From this, Professor Falkman thought that cancer cells that nutrients could not reach would die if they could inhibit the blood vessels gathered to the tumor. At that time many scientists were skeptical of Professor Falkman's thought, but in the late 1990s cancer drugs to inhibit angiogenesis were developed, "Can treat cancer within 2 years" It is until it is said that. Professor Hendricks and others' alleged "simulated angiogenesis" can overturn common sense of cancer treatment so controversy is occurring in the field of cancer treatment.

Professor Hendricks' research team did not intentionally discovered pseudo-angiogenesis. At that time, the research team, along with Professor Robert Fauberg, who is a pathologist at the University of Iowa, and whyMalignant melanomaI was studying whether it was deadly poisonous enough to kill a patient and that it spread quickly and there was something less dangerous. Then,Extracellular matrixIn an experiment that human malignant melanoma was planted on a gel imitating gastric cancer, he found that cancer cells moved around the extracellular matrix and made something like a tube on the surface.

Professor Fauberg, who participated in the study, observed in the past that similar phenomena occurred in the patient's eyes, initially thought that this tube was "a blood vessel". However, as the research progressed, it turned out that there was no endothelial cell that should be present in normal vessels, although red blood cells could be confirmed in the duct just like blood vessels. This means that cancer cells themselves made tubes.

However, in a paper by Professor McDonald 's and others announced several months later, it was pointed out that there was no proof that there was blood flow in the paper published by Professor Hendrix. Professor McDonald 's point of view, for example, was that he was commented by Professor Hendricks et al. As being "an extremely important discovery" from scientists in the same field, There was no power ".

ByWellcome Images

Professor Hendriks and others acknowledged that there was similar discovery in the past and not all evidence but said that evidence showing the existence of false angiogenesis is increasing and how the tumor is growing We are also disclosing a picture of whether blood vessels are formed in the brain and affect cancer treatment and prognosis. In meta-analysis conducted in China in 2016, it was also shown that survival rate sharply decreases for patients who have confirmed phenomena which seems to be simulated angiogenesis.

Researchers have not yet figured out how cancer cells connect to blood vessels. However, it is known how blood vessels are made from cancer cells. Among the tumor, it is only some cells that can make blood pipeline, which means that this tube acts on intracellular genes and tube is made like normal angiogenesis. Cells that undergo simulated angiogenesisCancer stem cellsIt has also been reported that it has similar properties and has drug resistance and the ability to differentiate into various cells, Professor George Murphy, a skin pathologist, said, "A very wise cancer cell sub It is like a group. " Besides, blood vessels constructed of cancer cells not only take away nutrients and oxygen from the blood, but also the possibility of promoting metastasis is regarded as dangerous.

In addition, research results that standard angiogenesis inhibitors can not stop pseudo-angiogenesis have also been published. Rather, when interfering with angiogenesis with a standard medicine, there was also seen a phenomenon that cancer cells whose nutrition and oxygen could not be obtained begin false vascularization.

And new clinical trials of therapeutic drugs that limit the growth of tumors have started in the US and Taiwan. The results of clinical trials have so far affirmed Professor Hendricks' theory and it seems that cancer cells have secured "a different means from angiogenesis" to incorporate nutrition and oxygen It is done.

TaiRx, a biotechnology company based in Taiwan, developed a medicine based on a compound of a plant called "CVM - 1118" that inhibits the growth of cancer cells, but this is based on Professor Hendriks et al. I heard that they showed an effect on pseudoangiogenesis. In CVM - 1118, phase 1 of the clinical trial is expected to be carried out in 2016 to confirm safety to people. In addition to CVM - 1118, drugs to inhibit pseudo - angiogenesis are currently being developed by American pharmaceutical companies.

ByKevin Morris

If these clinical trials succeed, it will greatly support the theory which Professor Hendricks' team and others have asserted for 17 years, and why is there a case where the effect is hard to be born for administration of medicine that inhibits angiogenesis? To be able to explain. Professor McDonald's argued that the research team greatly exhausted the research team, "We are satisfied if we can show people the possibility of a new approach to cancer," Hendricks said.