Treating Solid Tumors: Combining CAR-T Cell Therapy with Probiotics

Chimeric Antigen Recepter (CAR)-T cell therapy is a personalized immunotherapy that harnesses the patient’s own immune system to combat cancer. It is done by engineering the patient’s T cells to specifically target and attack cancer cells in their body, and it has shown great success in treating various blood cancers such as leukemia.

Treating solid tumors with CAR-T cells, however, has proved much more challenging. This is mainly because solid tumors contain a heterogeneous population of cells, expressing a variety of antigens—many of which are also expressed in healthy cells. Therefore, T cells targeting solid tumors could potentially attack healthy tissue, resulting in serious side effects. In addition, solid tumors create a hostile microenvironment that is difficult for CAR-T cells to infiltrate.

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Three Reasons You Should Test Your CRC Patients’ MSI Status

Oncologists, do you know your colorectal cancer patients’ MSI status?

High-frequency microsatellite instability (MSI-H) in tumors is a form of genomic instability where mismatch repair (MMR) proteins fail to properly correct errors in microsatellite regions of the genome. When a patient’s tumor tissue is determined to have MSI-H markers, it’s strongly recommended that they be further tested for Lynch syndrome, a hereditary condition that puts them and their family at a higher risk of developing colorectal and other cancers (1).

Though as many as 1 in 279 people might be carriers for the mutations associated with Lynch syndrome (2), 95% of them don’t know it (3). Furthermore, people with Lynch syndrome have an approximately 80% increased lifetime risk of developing colorectal cancer, compared to a risk of only ~4% for the general population (4, 5).  

On Lynch Syndrome Awareness Day, here are three key reasons why you should test all your colorectal cancer patients’ MSI status.

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Conversations: Nerve-Tumor Crosstalk in the Tumor Microenvironment

Cancer cells are characterized by features such as metabolic reprogramming and uncontrolled proliferation all of which are supported by underlying genomic instability, inflammation and the tumor microenvironment.

Cancer cells can be distinguished from normal cells by a variety of features including their ability to inappropriately activate signals for cell proliferation, evade growth suppression from contact inhibition or tumor suppressor activity, evade cell death signals, replicate DNA continually, induce angiogenesis, invade new tissues, reprogram their metabolism to provide energy for rapid proliferation, and evade immune detection (1) . Several biological processes are responsible for these features including genomic instability, inflammation, and the creation of a tumor microenvironment.

The tumor microenvironment is the network of non-malignant cells, connective tissue and blood vessels that surround and infiltrate the tumor. These surrounding “normal” cells interact with each other and the cancer cells and are important players in tumorigenesis. One cell type that is often found in the tumor microenvironment are nerve cells. In fact, cancer cells often express proteins that encourage nerve growth into the tumor microenvironment such as growth factors and axon-guidance molecules (2). Crosstalk between nerve cells and tumor cells can facilitate development of several cancer types (2) including pancreatic, head and neck, oral, prostate, and colorectal cancers.

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Finding Signs of Cancer in Dinosaur Fossils

Centrosaurus is a herbivorous Ceratopsian dinosaur that lived in Canada in the Cretaceous Period. A recent report describes the characterization of cancer in a Centrosaurus dinosaur fossil.
Centrosaurus is a herbivorous Ceratopsian dinosaur that lived in Canada in the Cretaceous Period.

Did dinosaurs get cancer? That isn’t an easy question to answer. Finding and diagnosing cancer in dinosaur fossils has proven difficult. Any soft tissue, the typical location of tumors, has degraded over the millennia. Fossilized bones millions of years old are subject to wear and tear, making it hard to distinguish bone damage from possible pathology. By using the knowledge and expertise gained from diagnosing cancer in humans, a team reported in The Lancet Oncology that they found the first known case of osteosarcoma in a lower leg bone from a horned dinosaur found in southern Alberta, Canada.

This case of bone cancer discovered in a specimen of Centrosaurus apertus found in the Canadian Dinosaur Park Formation was confirmed by examining the bone surface along with radiographic and histological analysis. The 77–75.5-million-year-old case was compared to both a normal C. apertus fibula from the Oldman formation also in southern Alberta, Canada, as well as a human fibula with an osteosarcoma.

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In Vitro Transcription and the Use of Modified Nucleotides

In vitro transcription
RNA polymerase unwinds DNA strands for transcription.

Transcription is the production of RNA from a DNA sequence. It’s a necessary life process in most cells. Transcription performed in vitro is also a valuable technique for research applications—from gene expression studies to the development of RNA virus vaccines.

During transcription, the DNA sequence is read by RNA polymerase to produce a complimentary, antiparallel RNA strand. This RNA strand is called a primary transcript, often referred to as an RNA transcript. In vitro transcription is a convenient method for generating RNA in a controlled environment outside of a cell.

In vitro transcription offers flexibility when choosing a DNA template, with a few requirements. The template must be purified, linear, and include a double stranded promoter region. Acceptable template types are plasmids or cloning vectors, PCR products, synthetic oligos (oligonucleotides), and cDNA (complimentary DNA). 

In vitro transcription is used for production of large amounts of RNA transcripts for use in many applications including gene expression studies, RNA interference studies (RNAi), generation of guide RNA (gRNA) for use in CRISPR, creation of RNA standards for quantification of results in reverse-transcription quantitative PCR (RT-qPCR), studies of RNA structure and function, labeling of RNA probes for blotting and hybridization or for RNA:protein interaction studies, and preparation of specific cDNA libraries, just to name a few!

In vitro transcription can also be applied in general virology to study the effects of an RNA virus on a cell or an organism, and in development and production of RNA therapeutics and RNA virus vaccines. The large quantity of viral RNA produced through in vitro transcription can be used as inoculation material for viral infection studies. Viral mRNA transcripts, typically coding for a disease-specific antigen, can be quickly created through in vitro transcription, and used in the production of vaccines and therapeutics.

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Targeting IL-6: How A Drug That Helped a 6-Year-Old Beat Cancer Can Save COVID-19 Patients

In 2012, a 6-year-old girl named Emily Whitehead was battling acute lymphoblastic leukemia (ALL), one of the most common cancers in children. Her cancer was stubborn. After 16 months of chemotherapy, the cancer still would not go into remission. There was nothing else the doctors could do, and she was sent home. She was expected to survive only a few more months. Her parents would not give up and enrolled her into a clinical trial of a new immunotherapy treatment called chimeric antigen receptor (CAR) T cell therapy. She was the first pediatric patient in the program.

Doctors took T cells from Emily’s blood and reprogrammed them in a lab. They essentially sent her T cells to boot camp where they are trained to find cancer cells and destroy them. The reprogrammed T cells were then injected back into her body. A week into treatment, she started getting a fever, the first sign that the treatment was working and her reprogrammed T cells were fighting the cancer. But soon, she got very sick. All of the indicators suggested that she had cytokine release syndrome (CRS)—also known as the cytokine storm. This happens when cytokines are released in response to an infection but the process cannot be turned off. The cytokines continue to attract immune cells to the infection site, causing damage to the patient’s own cells and eventually resulting in acute respiratory distress syndrome (ARDS). (Learn more about the cytokine storm in this blog.)

Emily was soon on a ventilator. Tests showed that she had extremely high levels of one particular cytokine: interleukin-6 (IL-6). Desperate to keep her alive, her doctors gave her a known drug that specifically targets IL-6. The results were dramatic. After one single dose, her fever subsided within hours, and she was taken off the ventilator. On May 2nd, 2012, she woke up from an induced coma—it was her 7th birthday. Her doctors said they have never seen a patient that sick get better that quickly.

The drug that saved her life was tocilizumab.

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Out-FOXOing High-Stage Neuroblastoma

Fluorescence microscopy of neuroblastoma cells.

In recent years, scientists have been hot on the trail of transcription factor FOXO3, tracing its involvement in various tumor-centric activities comprising the many trademarks of cancer, from drug resistance to metastasis to tumor angiogenesis.

FOXO3 is a member of the O sub-class of the forkhead box family of transcription factors. The forkhead box (FOX) family is characterized by a fork head DNA-binding domain (DBD), comprised of around 100 amino acids. They have also proven themselves to be a family of many hats, functioning in diverse roles ranging from metabolism, immunology, cell-cycle control, development, as well as cancer (1). The forkhead box O (FOXO) sub-class alone has demonstrated involvement in a variety of cellular outcomes, from drug resistance and longevity to apoptosis induction.

Due to its pro-apoptotic and anti-proliferative proclivity, FOXO3 has been previously identified as a tumor suppressor gene. However, more and more studies have begun to flip the narrative on FOXO3, portraying it more as a devoted henchman, due to its roles in drug and radiotherapy resistance, cell-cycle arrest and long-term maintenance of leukemia-initiating stem cells in a variety of cancer types, including breast cancer, pancreatic cancer, glioblastoma, and both acute and chronic myeloid leukemia.

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Immunotherapy—Don’t Forget the Microbiome

Bacteria make you sick. The idea that bacteria cause illness has become ingrained in modern society, made evident by every sign requiring employees to wash their hands before leaving a restroom and the frequent food recalls resulting from pathogens like E. coli. But a parallel idea has also taken hold. As microbiome research continues to reveal the important role that bacteria play in human health, we’re starting to see the ways that the microbiota of the human body may be as important as our genes or environment.

The story of how our microbiome affects our health continues to get more complex. For example, researchers are now beginning to understand that the composition of bacteria residing in your body can significantly impact the effects of therapeutic drugs. This is a new factor for optimizing drug response, compared to other considerations such as diet, interaction with other drugs, administration time and comorbidity, which have been understood much longer.

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The Randomness of Cancer

A major scientific study grabbed headlines recently, and the implications of its findings may affect many of us, if not all of us. In a paper published in Science by Cristian Tomasetti, Lu Li and Bert Vogelstein of Johns Hopkins University, the authors report that nearly two-thirds of known cancer-causing mutations can be attributed to random mistakes that occur during DNA replication. In other words, the vast majority of these mutations occur in a spontaneous, uncontrollable way— it may not matter how you live your life, or what measures you take to decrease your chance of developing cancer. As the authors and the press put it, it really just comes down to luck.

gene-mutation

Disturbing? For many, yes. It’s not easy to accept that one’s luck in activities such as winning the lottery may also apply to whether or not you will be touched by cancer. That is partly why this study is gaining so much attention.

As the authors explain in their publication, until now most cancer-causing mutations had been attributed to two major sources: inherited and environmental factors. But they found that a third kind of mutation, replicative (R) mutations that arise from unavoidable errors associated with DNA replication, account for 66 percent of cancer-causing mutations.

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Shooting for the Moon: Better Assays to Hit Our Cancer Research Targets

3239CA02_1AIn his address to the clinicians, researchers, and patients at the American Association for Cancer Research meeting in April, US Vice President Joe Biden, revealed that the goal of the #cancermoonshot initiative is to accomplish 10 years of cancer research in just five years, effectively doubling the pace of cancer research (1).

Treatments developed from cancer research have come a long way with dramatic differences in the experiences and prognoses for patients, just looking back over the last 25 years. How can we double the pace of cancer research? The #cancermoonshot will one, encourage data sharing among researchers, particularly data from clinical trials. Second, it seeks to increase collaboration across industry, academic and government scientists—each community being positioned to make unique contributions to the field. And third, the initiative looks to change the current grants award process that encourages scientists to keep data and results “quiet” until they can be published or protected legally as intellectual property.

Immunotherapy is an especially hot field in cancer research (2) that relies on the immune system to better fight cancer. Continue reading “Shooting for the Moon: Better Assays to Hit Our Cancer Research Targets”