Unexpected cell population key to blood cancer relapse

McMaster University researchers have provided evidence of new cancerous cells they have termed cancer regenerating cells, which are responsible for the return of acute myeloid leukemia after remission.

Current therapy is effective at inducing remission in adult patients with acute myeloid leukemia, but most patients later succumb after a relapse. That relapse has been thought to be caused by rare and dormant cancer stem cells that escape chemotherapy.

The study suggests that leukemia cells change in unique ways in response to the chemotherapy, allowing them to masquerade for a short time so they are able to start disease regeneration.

The research involved combined efforts from both scientists and physicians and spanned more than five years in development. The team took on the challenge of hunting down the rare leukemic cells that remain right after chemotherapy treatment. The surprise was that the most resilient cells left behind after the treatment did not fit the profile of cancer stem cells.

"Many cancer researchers, including our team, have thought it was dormant cancer stem cells that can resist chemotherapy treatment which go on to cause relapse," said Mick Bhatia, Director, McMaster Stem Cell and Cancer Research Institute.

Bhatia noted that, until now, the initial aftermath immediately after chemotherapy treatment has been largely unexplored, because leftover leukemia cells easily blend into the body and go undetected amid the chaos caused by the therapy itself."Chemotherapy is not entirely specific and destroys a lot of other tissues, making the patient's body a difficult place to do the detective work to find cells responsible for relapse," he said. He continues by saying "It's like trying to find a pen of unknown color or type in an office where a bomb went off. What we were trying to find is what causes the relapse somewhere where a bomb -- in this case chemotherapy -- had already caused so much collateral damage."

"This design allowed us to zero in on the few human leukemic cells that survived, because we could easily distinguish them from non-diseased mouse cells," said Lili Aslostovar, Postdoctoral Fellow, McMaster Stem Cell and Cancer Research Institute. "We were finally able to detail what takes place during this transient period before the storm of relapse occurs."

The key finding was to identify the point at which the disease retaliates by becoming highly regenerative, setting the stage for eventual relapse. This offered a new roadmap to identify the camouflaged cancer cells that hide out in the bone marrow of leukemia patients shortly after chemotherapy treatment. Importantly, similar patterns of leukemic regeneration could be seen across a spectrum of different patient subtypes, providing a common thread to guide the development of new therapies at the critical time point after chemotherapy.

"This is a major clinical opportunity because this type of leukemia is very diverse and responds differently across patients," said Allison Boyd, Postdoctoral Fellow, McMaster Stem Cell and Cancer Research Institute. She said, "It has been a challenge in a clinical setting to find a commonality for therapeutic targeting across the wide array of patients, and these regenerative cells provide that similarity."

The researchers hope that this new understanding of leukemic regeneration will provide physicians the opportunity to introduce additional drugs in combination with chemotherapy treatment. This will take advantage of chemotherapy's benefits while counteracting its shortcomings at the same time by targeting these altered cancer cells, said Bhatia.

"We were impressed that after chemotherapy, the disease seems to get very weak because the cancerous stem cells have been largely eliminated," said Boyd. "We think there are opportunities here because now we have a window where we can kick the cancer while it's down."

"Chemotherapy has increased the number of years cancer patients survive, but if you look at the overall death rates for people with leukemia, they are relatively unchanged," said Bhatia. "The problem is that the tumour comes back. It's the relapse, then, that kills the patients. Our goal is to prevent the relapse altogether."

We encourage researchers all around the globe to submit abstract on their latest research at our upcoming conference Cell Tissue Science 2019 which is mainly focuses on the complications the consequences of Stem Cell, Regenerative Medicine, Stem Cell Therapy, Cancer Cell Biology , Technical Advancements in cancer treatment and many more.We welcome you to the our upcoming conference “ 12th World Congress on Cell & Tissue Science” . For more info visit :Cell Tissue Science 2019

New discovery on T cell behavior has major implications for cancer immunotherapy

Scientists at the University of Colorado Anschutz Medical Campus have discovered that disease-fighting T cells, elicited from vaccines, do not require glucose for their rapid reproduction, a finding with major implications for the development of immunotherapies for cancer patients.

In this study, they examined T cells that arose in the body's immune system after they received a subunit vaccination—a vaccine that uses just part of a disease-causing virus.

They found that these critical white blood cells, which attack and kill infection, did not rely on glucose to fuel their rapid division which occurs every two to four hours. Instead, they used another cellular engine, the mitochondria, to support their expansion.

"The knowledge that this magnitude of cell division can be supported by mitochondrial function has a number of potential practical implications for the development of future vaccines," said Ross Kedl, Ph.D., Professor of Immunology and Microbiology, University of Colorado School of Medicine.

Kedl continued by saying"T cells responding to infection usually depend on glucose for fuel. So do cancerous tumors. When T cells come up against tumors, they end up competing for glucose and the T cells often lose".

But when a T cell doesn't need glucose, he noted, it has a better chance of defeating tumor cells.

"T cells generated by subunit vaccination are ideally suited for use against cancer in conjunction with drugs that block aerobic glycolysis, a metabolic pathway to which the cancer is addicted, Tumor growth can be inhibited while the T cells are free to attack the tumor instead of competing against it for access to glucose."" Kedl said. 

Jared Klarquist, Ph.D., explained that scientists have historically studied T cell responses to infection with the idea that if they could understand how the cells respond, they could create better vaccines. Kedl and colleagues had already discovered a non-infectious vaccine method that could induce the same level of T cell immunity as those using infection.

Since then, researchers in Kedl's lab have found that the rules governing T cell responses to an infectious agent are very different from the cell's response to a subunit vaccine. And the fact that T cells derived from subunit vaccines don't require glucose to reproduce is a major finding.

"Prior to these findings, it was generally thought that whereas the mitochondria are good at making energy, T cells need glucose to produce the raw materials like proteins, fats and nucleic acids (like DNA) required to turn one cell into two," said Klarquist. "Knowing how the immune response is fueled after vaccination provides potential opportunities for metabolic or nutritional interventions for boosting a vaccine-elicited immune response."

Kedl agreed and says "Perhaps most intriguing, however, is the application of this knowledge to cancer immunotherapy,"

 

We encourage researchers all around the globe to submit abstract on their latest research at our upcoming conference Cell Tissue Science 2019 which is mainly focuses on the complications the consequences of Stem Cell, Regenerative Medicine, Stem Cell Therapy, Cancer Cell Biology , Technical Advancements in cancer treatment   and many more.We welcome you to the our upcoming conference “ 12th World Congress on Cell & Tissue Science” . For more info visit :Cell Tissue Science 2019