by Azra Raza
Ninety percent cancers diagnosed at Stage I are cured. Ninety percent diagnosed at Stage IV are not. Early detection saves lives. Unfortunately, more than a third of the patients already have advanced disease at diagnosis. Most die. We can, and must, do better. But why be satisfied with diagnosing Stage I disease that also requires disfiguring and invasive treatments? Why not aim higher and track down the origin of cancer? The First Cell. To do so, cancer must be caught at birth. This remains a challenging problem for researchers.
Cancer is a silent killer. To sight its diverse neonatal guises and behavior, we need to get more creative. Maybe change direction and look for the earliest stages of carcinogenesis in people who don’t have cancer yet but are at high risk of developing it. But what should we be looking for? Among many possibilities, one answer is Giant cells. This installment of the series on cancer is devoted to how, when and why these weird distended, strikingly abnormal looking gigantic cells appear in tumors and in the blood of cancer patients.
Giant cells: Hiding in plain sight
First identified in 1838 by Muller, and described with beautiful accompanying illustrations by Virchow in 1858, bloated giant cancer cells with many nuclei, have been regularly seen in tumors and labeled as dying or degenerating cells, incapable of dividing, and therefore of no importance. Besides, in fully formed cancers, they are extremely rare, close to negligible. Their number increases during relapse of cancer after treatment has destroyed the majority of tumor cells. Giant cells appear when there are no other cancer cells and disappear when cancer cells reappear.
A pair of coincidental happenings led me to conclude that cancer might originate in two cells that fuse and cooperate for mutual benefit, forming a Giant cell. Most likely, an exaggerated response to stress in the organ (infection, toxic exposure?).
This is not the first-time cooperation rather than competition has carried the day in biology. After all, every single living creature that has more than one cell can trace its roots back to a fusion of two unicellular organisms. If life has existed on Earth for 3.7 billion years, it was entirely made up of one-celled creatures, like tiny bacteria, until a billion years ago, when two unicellular beings fused, resulting in multi-cellular organisms making up the millions of animal and plant species we see today. The proof of this symbiotic merger is the presence of mitochondria in our cells. When the late Lynn Margulis first proposed that mitochondria were once independently living bacteria, she was ignored and ridiculed for her theory. After her idea was finally accepted, Ernst Mayer called it “Perhaps the most important and dramatic event in the history of life.”
One of my morning routines includes jumping on a rebounder (trampoline, the small indoor kind). The high impact on a soft surface, in addition to several physical benefits, massages the soles of feet, stimulating the lymphatics, and hence the immune system. Ray Kurzweil, an avid follower of this routine, claims in his book, Fantastic Voyage: Live long enough to live forever, that 10 minutes on a trampoline is equal to half an hour of running. I listen to lectures on YouTube while trampolining, and in August of 2019, I heard one entitled ‘To the fields of Evolution and Ecology: My patients, thank you for making me a better doctor – and scientist’ by Ken Pienta, an oncologist and prostate cancer researcher at Johns Hopkins University.
In an attempt to understand metastasis and treatment resistance, Ken and his team put together an engineered microenvironment to mimic the “cancer swamp”. Prostate cancer cells in the device were subjected to chemotherapy using a gradient. “We were studying Game Theory at the same time,” Ken said, “Modeling the strategic interaction between two or more players in a situation containing set rules and outcomes. We wanted to see how cancer cells with different attributes would interact when exposed to a stress.” He was not expecting what he saw.
When prostate cancer cells were exposed to a gradient of chemotherapy, after 99% of the cells died, there emerged very large giant cells that moved very fast. “They survived and thrived even when exposed to a dose of drug that should have killed them. Then, as we watched, tiny cells expanded out of the giant cells and repopulated the space. Our movies demonstrated that these giant cells were highly motile and resistant to therapy, possibly explaining metastasis and resistance.”
So, why is no one talking about the formation of these Giant Cells that ride out the stress of chemotherapy, and when things return to normal, they literally “deliver” babies, birthing smaller cells causing relapse of cancers resistant to therapy? They were too few in number, too abnormal in structure, considered functionally impotent and therefore ignored. But not by all. “It turns out there are some 70 papers over 30 years describing multinucleated giant cells in response to stress,” Ken said.
I was deeply intrigued by Ken’s model. The First Cell could be a Giant cell because it is a hybrid. It reminded me of an ancient tale.
Two close friends, Dev and Kapila fall in love with Padmini. Dev is all mind, a poet, Kapila, all body, a farm hand. Seduced by the poems of Dev, Padmini marries him, yet, cannot help being attracted to the handsome Kapila. The triangle heats up, until, in a supreme act of self-sacrifice, the friends commit suicide by simultaneously beheading themselves. Padmini comes upon the macabre scene and begs the Goddess Kali for their lives. Kali takes pity and tells Padmini to place the heads back on the bodies and she will grant them life. In her haste, Padmini mixes up the heads. The friends come back to life. With exchanged heads and bodies.
Whose wife is Padmini? What constitutes real identity?
Originally told by a ghost to a king in the ancient collection of Sanskrit tales, Kathasaritsagara, the story has been retold in many forms, including the play Hayavadana (Horse-man) by Girish Karnad, and Transposed Heads by Thomas Mann. Fusion of the superior mind (Dev) with the superior body (Kapila) produced a perfect hybrid. The Sacred Texts ruled that among human limbs, the head is supreme, therefore, her husband is the one with Dev’s head. The best of both worlds for Padmini. She goes off with Dev.
Could The First Cell be the result of a fusion too, a case of transposed heads? The nucleus (head) of a stressed cell inside the body (cytoplasm) of a normal cell? But how and why would cancer emerge from such a hybrid? After all, stress caused by therapy results in the appearance of Giant cells at relapse. Why can’t it be the event at initiation of cancer?
Mea Culpa: Giant Cells ignored in my lab for five years
In the next lab meeting, I described Ken’s findings, and Abdullah Ali, Director of the Translational Research program said, “But Dr. Raza, don’t you remember we saw Giant cells in our very first CRISPR experiments?” Yes, of course! Some five years prior, Abdullah designed a strategy and helped create a hot-spot mutation in the SF3B1 gene in a leukemia cell line (K562). A striking observation made simultaneously by Abdullah, and our colleague and lab partner, Siddhartha Mukherjee (Emperor of All Maladies fame), was the abundance of distended Giant cells with many many nuclei.
At the time, we thought the Giant cells must be megakaryocytes, platelet forming cells, that are naturally huge with many nuclei. It was conceivable that the myeloid leukemia cell line K562 was differentiating toward the megakaryocytic lineage. Abdullah performed special stains to identify the cells, and while some of them tested faintly positive for the expected markers, no definite identity was established. Like others before us, we also ignored the Giant cells and continued with our planned experiments on the mutant cells. Shockingly stupid in retrospect. A perfect example of Confirmation Bias.
Then I heard Ken’s lecture.
We thawed out the CRISPR’d cells sitting in the freezers for five years, and Abdullah, along with our junior scientific colleague, Sanjay, performed a series of elaborate experiments to replicate precisely what Ken had shown. Stress caused by chemotherapy induced the appearance of Giant cells with lots of nuclei. Time lapse video from my lab following a single Giant cell in the picture below shows that after an initial three days of quiescence, it started birthing a large number of smaller cells (73 and 74 hours).
Jinsong Liu, a top researcher in the field whose work I will discuss in a subsequent article, aptly named it ‘Somatic Cell Pregnancy’.
There is no remembrance of men of old, and even those who are yet to come will not be remembered by those who follow
What has been will be again,
What has been done will be done again;
There is nothing new under the sun
In reviewing the literature, I became aware of an age-old hypothesis that suggests a startlingly similar idea back in 1911 that cancers become invasive when a tumor cell fuses with a white blood cell immediately solving two problems for the cancer cell. The normal blood cell can travel everywhere in the body but ages and dies. The cancer call can live forever but is immobile. By fusing together, the hybrid cell can travel everywhere and live forever, evading detection by the immune system. Hiding in plain sight.
Some say that the protagonist, Otto Aichel, a German gynecologist, conjured this simple explanation because his entire laboratory consisted of a microscope. I think he came up with the genius solution precisely because he had only a microscope to rely on. In today’s world, biology plays second fiddle to molecular biology. My niece, Zee Beams, teased me, “Achi, molecular biology is to biology what baking is to cooking.” To cure cancer, Aichel would be expected to use the tools of molecular biology to sort out the inner happenings of a cell containing a trillion molecules. It is a fine goal, but one that may take a hundred years to realize. In the meantime, millions are dying of cancer, waiting for a solution. Obsession with a technique has set the field back by decades, because, as Ken quoted D W Smithers, “You cannot learn much about what causes a traffic jam by studying the fine structure of the internal combustion engine of a car.”
Cellula prima fit duobus de cellulis: The First Cell is Two Cells
The elegant work of Ken Pienta and many others in the last several decades showing proof of cell fusion in cancer have concentrated on its importance in metastatic, resistant disease. I propose that the same could be happening at cancer initiation. With current techniques, we can only diagnose cancer at the late stage when only the small cells are predominant, while those responsible for the early stages of carcinogenesis, the Giant cells, The First Cells, have long gone. We have been missing the drama of cancer’s birth entirely.
When treatment causes stress, killing off most of the small cells, Giant cells reappear and provide sanctuary for some of the surviving stressed cells, releasing them once the stress is gone. The newly-rebirthed cells come with a re-engineered DNA that makes them more aggressive, more invasive, more rapidly proliferative, and more resistant to future treatments. The killer machines we know and dread.
I have proposed that The First Cell is two cells. What existing date support this possibility? I will describe this in more detail in the next installment. I end now by recounting the unexpected conclusion of the Transposed Heads story. Padmini and Dev (armed with Kapila’s superb body), discover surprising new pleasures. With time though, Dev becomes engrossed in his intellectual activities once again, neglecting the body that slowly reverts back to its old soft, plump, sagging self. Meantime, Kapila, living in the dense forest, used to manual labor, transforms the weak body of Dev into a brawny, robust, muscular physique, regaining his strength even as Dev gradually lost his. The transposed heads, forcing back the bodies to their original forms; the intellectual with the weak body and the farmhand with the strong one.
Can the earliest fused cells, the Giant cells, be forced to revert to their benign selves before they nurse and birth the malignant clone of smaller cells? If the Giant cells are important as The First Cells, what strategies can be envisioned to eliminate them?
The culprit may not even be the Giant cell. It could just as well be a handful of genes (somatic mutation theory) in a stressed cell or thousands of them (aneuploidy), or it could be the tissue organization gone awry, or all of the above or none of the above. I remain agnostic. I am happy to be proved wrong. What I am certain about is that we need to look. To prevent cancer, we need to examine the earliest stage of cancer. The work ahead is enormous. Science does not function on faith. Data are what we need. Emily Dickinson’s advice is spot on:
“Faith” is a fine invention
For Gentlemen who see!
But Microscopes are prudent
In an Emergency!
The next part in this series of articles is here.
Source of the first Giant Cell picture: https://www.westend61.de/en/imageView/CUF06157/microscopic-image-of-polyploid-giant-cancer-cell