Study is expected to result in new clinical laboratory test biomarkers based on proteins shown to be associated with specific diseases
In January, the UK Biobank announced the launch of the “world’s most comprehensive study” of the human proteome. The study focuses on proteins circulating throughout the human body. Researchers involved in this endeavor hope the project will transform disease detection and lead to clinical laboratory blood tests that help diagnosticians identify illnesses earlier than with conventional diagnostics.
Building on the results of a 2023 pilot project that studied “the effects of common genetic variation on proteins circulating in the blood and how these associations can contribute to disease,” according to a UK Biobank news release, the 2025 UK Biobank Pharma Proteomics Project (UKB-PPP) plans to analyze up to 5,400 proteins in 600,000 samples to explore how an individual’s protein levels changes over time and how those changes may influence the existence of diseases in mid-to-late life.
The specimens being analyzed include 500,000 samples extracted from UK Biobank participants and an additional 100,000 set of second samples taken from volunteers up to 15 years later.
“The data collected in the study will allow scientists around the world to conduct health-related research, exploring how lifestyle, environment, and genetics lead through proteins to some people developing particular diseases, while others do not,” Sir Rory Collins, FMedSci FRS, professor of medicine and epidemiology at University of Oxford and principal investigator and chief executive of the UK Biobank, told The Independent.
“That will allow us to identify who it is, who’s likely to develop disease well before they do, and we can then look at ways in which to prevent those conditions before they develop,” he added.
“It really might be possible to develop simple blood tests that can detect disease much earlier than currently exists,” said Naomi Allen, MSc, DPhil (above), chief scientist for UK Biobank and professor of epidemiology at Oxford Population Health, University of Oxford, in an interview with The Independent. “So, it adds a crucial piece in the jigsaw puzzle for scientists to figure out how disease develops and gives us firm clues on what we can do to prevent and treat it.” Clinical laboratories may soon have new test biomarkers that help identify proteins associated with specific diseases. (Photo copyright: UK Biobank.)
Developing New Protein-based Biomarkers
A proteome is the entire set of proteins expressed by an organism, cell, or tissue and the study of the proteome is known as proteomics. The proteome is an expression of an organism’s genome, but it can change over time between cell types and growth conditions.
The human genome contains approximately 20,000 genes and human cells have between 80,000 and 400,000 proteins with specific cells having their own proteomes. Proteomics can help ascertain how proteins function and interact with each other and assist in the identification of biomarkers for new drug discoveries and development.
“This is hugely valuable, because it will enable researchers to see how changes in protein levels within individuals over mid- to late-life influence the development of a whole range of different diseases,” said Naomi Allen, MSc, DPhil, chief scientist for UK Biobank and professor of epidemiology at the Oxford Population Health, University of Oxford, in The Independent. “It will accelerate research into the causes of disease and the development of new treatments that target specific proteins associated with those diseases.
“The pilot data is already showing that specific proteins are elevated in those who go on to develop many different types of cancers up to seven years before a clinical diagnosis is made. And for dementia, up to 10 years before clinical diagnosis is made,” she added.
According to the project’s website, the UK Biobank’s proteomics dataset will allow researchers to:
Examine proteomic and genetic data from half a million people to provide a more detailed picture of the biological processes involved in disease progression.
Examine how and why protein levels change over time to understand age-related changes in healthy individuals.
Utilize proteomic data together with imaging data to understand disease mechanisms.
“Data from the pilot study has shown that specific proteins are substantially elevated in individuals with autoimmune conditions like multiple sclerosis and Crohn’s disease and so on,” Allen noted. “So, you can see how a simple blood test could be used to complement existing diagnostic measures in order to diagnose these types of diseases more accurately and perhaps more quickly.”
An Invaluable Resource of Knowledge
The initial UK Biobank started in 2006 and, to date, has collected biological and medical data from more than half a million individuals. The subjects of the UKB-PPP study are between the ages of 40 and 69 and reside in the UK. The database is globally accessible to approved researchers and scientists engaging in research into various diseases.
The full dataset of the latest research is expected to be added to the UK Biobank Research Analysis Platform by the year 2027. The newest study is backed by a consortium of 14 pharmaceutical firms.
Allen also noted that evidence from the research has emphasized how some drugs may be useful in treating a variety of conditions.
“Some proteins that are known to be important for immunity are related to developing a range of psychiatric conditions like schizophrenia, depression, bipolar disorder and so on,” she told The Independent. “And given there are drugs already available that specifically target some of these proteins that are used for other conditions, it presents a real opportunity for repurposing those existing drugs for these neuropsychiatric conditions.”
This type of comprehensive study of the human proteome may have a great impact on patient diagnosis and treatment once the study is completed and the results are disclosed.
“The data will be invaluable. The value of the data is infinite,” Collins told The Independence.
Since it is clinical laboratories that will be engaged in testing for proteins that have become associated with specific diseases, this new UK Biobank study has the potential to expand knowledge about useful protein markers for both diagnosis and therapeutic solutions (prescription drugs).
Clinical laboratories and anatomic pathology groups should prepare for a marked increase in orders for liver disease testing
New research from Virginia Commonwealth University’s Institute for Liver Disease and Metabolic Health in Richmond shows that four out of every 10 Americans has fatty liver disease of some type, according to a news release. Forty percent of Americans is an astonishing number! The study’s findings will almost certainly lead to clinical laboratories performing more testing in support of diagnosis, treatment decision making, and patient monitoring for liver disease than currently ordered by physicians.
Hepatologist Juan Pablo Arab, MD, director of alcohol sciences at Virginia Commonwealth University (VCU), led the team that conducted the research. He noted that the driving force behind the numbers is obesity and type two diabetes.
“By 2018, federal data showed that 42% of adults had some form of fatty liver disease—higher than prior estimates,” Arab’s team told Newsmax, adding that “Hispanic adults were at especially high risk … with nearly half (47%) affected.”
“This study highlights a significant health issue that affects a large portion of the US population, and it shows that certain groups are at a higher risk. We hope these findings will guide more targeted health interventions to reduce the burden of liver disease, especially in high-risk communities,” said Juan Pablo Arab, MD (above), hepatologist with VCU’s Institute for Liver Disease and Metabolic Health, director of alcohol sciences, and lead researcher in the VCU study, in a VCU news release. These insights can be expected to lead to guidelines calling for more clinical laboratory testing associated with the diagnosis of fatty liver disease. (Photo copyright: Virginia Commonwealth University.)
“Groups at greater risk for MASLD include men, adults older than 40, individuals with health insurance, those with higher body mass index, and people with other health issues like diabetes, high blood pressure, high triglycerides, and low levels of good cholesterol. Interestingly, the study found that black individuals had the lowest risk of developing MASLD compared with other groups,” the VCU news release notes.
Fatty liver disease can also be caused by excessive alcohol consumption (called alcohol-associated liver disease or ALD) or a combination of both metabolic dysfunction and moderate-to-high alcohol intake, which is called MetALD, Newsmax reported.
“Although MASLD was the most common type of liver disease found in this study, the researchers also uncovered substantial rates of MetALD and alcohol-associated liver disease. For MetALD, the study showed that men and individuals with a higher BMI [body mass index] were at a greater risk, and Asians were at lower risk. Surprisingly, the only factor that appeared to lower the risk of ALD was having health insurance, though the reasons for this are not clear,” according to the VCU news release.
On its website, Mayo Clinic notes that NAFLD is often symptomless, and that doctors typically depend on routine clinical laboratory blood test results to reach a diagnosis. Additional testing helps determine whether higher than normal liver enzymes are actually from fatty liver disease or some other condition.
Medical laboratories play a key role in facilitating the final diagnoses. According to Mayo Clinic, blood tests to identify liver disease include:
Medical imaging could also be required to reach a diagnosis, beginning with an abdominal ultrasound, Mayo Clinic added. Additionally, more precise tests may be ordered to determine the stiffness of the liver and likelihood of scarring or fibrosis. Those modalities include:
Labs will often perform these tests on the same patient multiple times as the patient’s lifestyle changes. A liver biopsy may also be required to determine severity of damage, Mayo Clinic added.
abdominal pain, spider-like blood vessels, yellowing of the skin and eyes (jaundice), itching, fluid buildup and swelling of the legs (edema) and abdomen (ascites), and mental confusion,” the ALF added.
As more healthcare providers focus their attention on diagnosing and treating this potentially deadly disease, clinical laboratories and anatomical pathology groups will likely see an uptick in tests ordered by doctors moving from initial diagnoses to more detailed testing and eventually to treatment follow ups.
Microbiologists and clinical laboratory professionals should play a key role in the ordering and use of microbiome testing
International experts in the field of microbiome testing recently published a consensus document that establishes guidelines for the use and distribution of microbiota diagnostics they claim are long overdue. Companies offering direct-to-consumer (DTC) microbiome test kits continue to increase in number and popularity. But some experts in the human microbiome field—including microbiologists and clinical laboratory professionals—remain apprehensive regarding the science behind this type of home testing.
A Gemelli University news release states, “The intestinal microbiota could perhaps one day become a routine tool for the early diagnosis of many diseases and treatment guidance, but at the moment there is a lack of solid scientific evidence to support these indications. Yet, day by day, the offers of commercial kits are multiplying to carry out do-it-yourself tests, at the moment completely devoid of scientific significance and solidity.”
It continues, “To put a stop to this drift, a panel of international experts, coordinated by Dr. Gianluca Ianiro, has drafted the ‘instructions for use’ for best practices related to microbiota testing and recommendations for its indications, analysis methods, presentation of results and potential clinical applications.”
“This document marks a decisive step towards a standardization that has become indispensable making the microbiota an increasingly integrated element in personalized medicine,” said gastroenterologist Antonio Gasbarrini, MD (above), dean of the faculty of medicine and surgery and full professor of internal medicine at Catholic University of the Sacred Heart. “In the clinical context, these guidelines will be essential to translate research progress into concrete applications, improving the management of many gastroenterological and systemic diseases related to the microbiota,” he added. Microbiologists and clinical laboratory managers may want to follow efforts to promote these guidelines, both within healthcare and as they relate to consumers ordering their own microbiome tests. (Photo copyright: Agostino Gemelli University.)
Our Second Brain
The gut microbiome consists of the microorganisms that reside in the human gut and the small and large intestines. This ecosystem plays a major role in an individual’s health as it aids in digestion and metabolism. It also helps control inflammation and can strengthen the immune system.
“[The gut microbiome] contains all the microbes that reside within our intestinal tract. And those microbes are comprised of bacteria, fungi, yeast and viruses,” said Gail Cresci, PhD, RD, Director, Nutrition Research Center for Human Nutrition at the Cleveland Clinic in a Health Essentials article.
“What we’ve learned over the years is that there’s a lot of crosstalk between your gut microbiome and your body,” she added.
A healthy gut microbiome is imperative for good human health. An unhealthy gut microbiome can lead to certain diseases and even have a negative effect on mental health and mood.
“Your gut health is so important because studies really do indicate that our gut health plays a huge role in our overall health,” stated Kristin Kirkpatrick, MS, RDN, a dietician at the Cleveland Clinic Department of Wellness and Preventative Medicine, in the article. “It impacts our risk of chronic conditions, our ability to manage our weight, even our immune system. … There is so much attention and research on the microbiome and gut health now that experts often refer to it as the ‘second brain.’”
Future of Microbiome Testing
In their consensus document, the scientists wrote, “We convened an international multidisciplinary expert panel to standardize best practices of microbiome testing for clinical implementation, including recommendations on general principles and minimum requirements for their provision, indications, pre-testing protocols, method of analyses, reporting of results, and potential clinical value. We also evaluated current knowledge gaps and future directions in this field.”
The team’s intent is to provide guidelines and define quality standards and accuracy for microbiome testing to ensure consumers are receiving factual information.
“In recent years, the intestinal microbiota has taken on a key role as a diagnostic, prognostic and therapeutic tool,” said gastroenterology surgeon Serena Porcari, MD, of Gemelli University Hospital in Italy, in the Gemelli news release. “From this point of view, the first step, for a targeted modulation of the microbiota itself, is to obtain a standardization of its analysis, regulated according to the definition of minimum criteria for performing the test.”
The team also evaluated disparities between various tests and anticipated what lies ahead for the future of microbiome testing. In addition, they assessed ways to minimize inappropriate testing and established a framework for the development of evidence-based testing and the use of human microbiota diagnostics in clinical medicine.
“This consensus document represents a crucial step towards bringing order to the current panorama of diagnostic tests on the intestinal microbiota,” said Maurizio Sanguinetti, MD, director of the department of laboratory and hematological sciences at Gemelli Polyclinic Foundation, in the news release. “The diagnostic characterization of the intestinal microbiota must be based on rigorous standards, in order to guarantee reliable and clinically useful results. It is not a simple laboratory test, but a complex tool that requires a deep understanding of microbial dynamics and their impact on human health.
“This is why these analyses must be conducted by highly qualified personnel with specific expertise in clinical microbiology and bioinformatics,” he emphasized. “In our microbiology laboratory at the Fondazione Policlinico Gemelli, we already apply diagnostic tests on the intestinal microbiota following the principles and best practices outlined in the document.
“It is essential to invest in the training of future physicians and microbiologists so that they acquire the necessary skills to correctly interpret the results of these tests and apply them effectively in clinical practice. This document provides a valuable basis to guide not only the current use of the tests, but also their future development, always with a view to evidence-based and personalized medicine,” Sanguinetti concluded.
With popularity of microbiome testing on the rise, it’s important that microbiologists and clinical laboratory professionals stay informed on the latest developments in the field of microbiome diagnostics to protect healthcare consumers and their patients.
Managers of pathology groups and clinical laboratories can learn from the challenges confronting the radiology profession
Members of the Intersociety Committee of the American Society of Radiology (ACR) recently met in Coronado, Calif., to discuss the “most pressing” challenges to their profession and investigate possible solutions, according to Radiology Business. Many of these challenges mimic similar challenges faced by anatomic pathology professionals.
The radiology leaders identified seven of the “most important challenges facing radiology today.” They include: declining reimbursement, corporatization and consolidation, inadequate labor force, imaging appropriateness, burnout, turf wars with nonphysicians, and workflow efficiency, according to a report on the meeting published in the Journal of the American College of Radiology (JACR).
“Solving these issues will not be easy,” said Bettina Siewert, MD, diagnostic radiologist at Beth Israel Deaconess Medical Center (BIDMC) in Boston, Mass., professor of radiology at Harvard, and lead author of the JACR report, in the JACR. “This is a collection of ‘wicked’ problems defined as having (1) no stoppable rule, (2) no enumerable set of solutions or well-described set of permissible operations, and (3) stakeholders with very different worldviews and frameworks for understanding the problem,” she added.
“The Intersociety Committee is a freestanding committee of the ACR established to promote collegiality and improve communication among national radiology organizations,” JACR noted.
“Taken together, a ‘perfect storm’ of pressures on radiologists and their institutions is brewing,” said Bettina Siewert, MD (above), diagnostic radiologist at Beth Israel Deaconess Medical Center in Boston, Mass., professor of radiology at Harvard, and lead author of the JACR report. Wise pathology and clinical laboratory leaders will see the similarities between their industry’s challenges and those facing radiology. (Photo copyright: Beth Israel Deaconess Medical Center.)
How Radiology Challenges Correlate to Pathology Practices
Here are the seven biggest challenges facing radiology practices today as identified by the Intersociety Committee of the ACR.
Declining Reimbursement: According to the ACR report, radiologists in 2021 performed 13% more relative value units (RVUs) per Medicare beneficiary compared to 2005. However, the inflation-adjusted conversion factor fell by almost 34%––this led to a 25% decline in reimbursements.
This issue has plagued the pathology industry as well. According to an article published in the American Journal of Clinical Pathology (AJCP), prior to adjusting for inflation, the average physician reimbursement increased by 9.7% from 2004 to 2024 for all included anatomic pathology CPT codes. After adjusting for inflation, the average physician reimbursement decreased by 34.2% for included CPT codes. The greatest decrease in reimbursement observed from 2004 to 2024 was for outside slide consultation at 60.5% ($330.12 to $130.49), followed by pathology consultation during surgery at 59.0% ($83.54 to $34.29). The average CAGR was -2.19%,” the authors wrote.
“Our study demonstrates that Medicare physician reimbursement for common anatomic pathology procedures is declining annually at an unsustainable rate,” the AJCP authors added.
The radiologists who identified this trend in their own field suggest that medical societies could lead the push to minimize the reimbursement cuts. Pathologists could also adopt this ‘strength in numbers’ mentality to advocate for one another.
Corporatization Consolidation: The authors of the ACR report identified this issue as limiting job opportunities for radiologists particularly in private practice. Pathology professionals have seen the same trend in their field as well. Increasingly, small pathology groups have been consolidated into larger regional groups. Some of those larger regional pathology groups will then be acquired by public laboratory corporations.
The authors of the ACR report suggest radiologists should be educated on the pros and cons of consolidation. They also suggest pursuing unionization.
Inadequate Labor Force: In both radiology and pathology there is a supply-and-demand issue when it comes to labor. Staffing shortages have been felt across all of healthcare, but particularly among pathology groups and clinical laboratories. Siewert and her co-authors suggest a three-pronged approach to address this issue:
Creating residency positions in private practice.
Recruiting international medical graduates.
Increasing job flexibility.
Pathology professionals could apply these same ideas to help close the gap between the open positions in the field and the number of professionals to fill them.
Imaging Appropriateness: A gap between service capacity and service demand for radiology imaging has created a frustrating mismatch between radiologists and clinicians. Radiology experts point to overutilization of the service causing the supply-and-demand crisis. Comparatively, pathologists see a similar issue in complex cases requiring more pathologist time to come to an appropriate diagnosis and identify a care plan.
“To facilitate this reduction, better data on imaging outcomes for specific clinical questions are urgently needed,” the authors of the ACR report wrote as a possible solution. “Considering the magnitude of the mismatch crisis, radiologists may also need to consider expanding their consultative role to include that of a gatekeeper, as is done in other more resource-controlled countries.”
Burnout: Perhaps one of the most talked about subjects in the medical field has been burnout. The issue has been thrust to the forefront with the COVID-19 pandemic; however, the burnout crisis began before the pandemic. About 78% of radiologists surveyed for this report claimed to be exceeding their personal work capacity.
The authors of the ACR report suggest a structured approach to air grievances without descending into despair. “Using a team approach based on the concept of listen-sort-empower, burnout can be combatted by fostering free discussion between frontline workers and radiologists,” they said. “Facilitators unaffiliated with the radiology department can help to maintain focus on gratitude for positive attributes of the work and the institution as well as to keep the sessions on task and prevent them from devolving into complaint sessions with a subsequent loss of hope.”
A similar approach could be applied to pathology groups and clinical laboratory to combat worker burnout as well.
Turf Wars with Nonphysicians: Over the last five years the number of imaging exams being interpreted by nonphysician providers has increased by 30%, according to the ACR report. The writers emphasized the need for increased understanding and awareness about the importance of physician-led care. They suggest solidarity among hospital medical staff to provide a united front in addressing this issue in hospital bylaws.
In pathology, the counterpart is how large physician groups are bringing anatomic pathology in-house. This has been an ongoing trend for the past 20 years. It means that the pathologist is now an employee of the physician group (or a partner/shareholder in some cases).
Increase Workflow Efficiency: Image interpretation accounts for only 36% of the work radiologists perform, the ACR report noted. This issue has a direct counterpart in pathology where compliance requirements and various tasks take time away from pathologist diagnosis. These issues could be solved by working AI into tasks, delegating non-interpretive tasks to other workers, and improving the design of reading rooms. All of these possible solutions could also be applied to clinical pathologists.
These issues being faced by radiologists compare directly to similar issues in the clinical pathology world. Pathologists and pathology group managers would be wise to learn from the experience of their imaging colleagues and possibly adopt some of the ACR’s suggested solutions.
Anatomic pathologists understand that, along with breast cancer, diagnostic testing for prostate cancer accounts for a high volume of clinical laboratory tests. Thus, a recent study indicating that a new artificial intelligence (AI)-based software tool can dramatically improve physicians’ ability to identify the extent of these cancers will be of interest.
“The study found that Unfold AI’s patient-specific encapsulation confidence score (ECS), which is generated based on multiple patient data points, including MRI scans, biopsy results, PSA [prostate-specific antigen] data, and Gleason scores, is critical for predicting treatment success,” an Avenda press release states. “These findings emphasize the importance of Unfold AI’s assessment of tumor margins in predicting treatment outcomes, surpassing the predictive capability of conventional parameters.”
“Unfold AI’s ability to identify tumor margins and provide the ECS will improve treatment recommendations and allow for less-invasive interventions,” said study co-author Wayne Brisbane, MD, a urologic oncologist and UCLA medical professor, in another press release. “This more comprehensive approach enhances our ability to predict treatment outcomes and tailor interventions effectively to individual patient needs.”
“This study is important because it shows the ability of AI to not only replicate expert physicians, but to go beyond human ability,” said study co-author Wayne Brisbane, MD (above), a urologic oncologist and UCLA medical professor, in a press release. “By increasing the accuracy of cancer identification in the prostate, more precise and effective treatment methods can be prescribed for patients.” Clinical laboratories that work with anatomic pathologists to diagnose prostate and other cancers may soon have a new AI testing tool. (Photo copyright: UCLA.)
How Unfold AI Works
To gauge the extent of prostate tumors, surgeons typically evaluate results from multiple diagnostic methods such as PSA tests and imaging scans such as MRIs, according to a UCLA press release. However some portions of a tumor may be invisible to an MRI, causing doctors to underestimate the size.
Unfold AI, originally known as iQuest, was designed to analyze data from PSA, MRI, fusion biopsy, and pathology testing, according to a company brochure. From there, it generates a 3D map of the cancer. Avenda’s website says the technology provides a more accurate representation of the tumor’s extent than conventional methods.
“Accurately determining the extent of prostate cancer is crucial for treatment planning, as different stages may require different approaches such as active surveillance, surgery, focal therapy, radiation therapy, hormone therapy, chemotherapy, or a combination of these treatments,” Brisbane said in the UCLA press release.
Putting AI to the Test
In the new study, the UCLA researchers enlisted seven urologists and three radiologists to review 50 prostate cancer cases. Each patient had undergone prostatectomy—surgical removal of all or part of the prostate—but might have been eligible for focal therapy, a less-aggressive approach that uses heat, cryotherapy, or electric shocks to attack cancer cells more selectively.
The physicians came from five hospitals and had a wide range of clinical experience from two to 23 years, the researchers noted in The Journal of Urology.
They reviewed clinical data and examined MRI scans of each patient, then “manually drew outlines around the suspected cancerous areas, aiming to encapsulate all significant disease,” the press release states. “Then, after waiting for at least four weeks, they reexamined the same cases, this time using AI software to assist them in identifying the cancerous areas.”
The researchers analyzed the physicians’ work, evaluating the accuracy of the cancer margins and the “negative margin rate,” indicating whether the clinicians had identified all of the cancerous tissue. Using conventional approaches, “doctors only achieved a negative margin 1.6% of the time,” the press release states. “When assisted by AI the number increased to 72.8%.”
The clinicians’ accuracy was 84.7% when assisted by AI versus 67.2% to 75.9% for conventional techniques.
They also found that clinicians who used the AI software were more likely to recommend focal therapy over more aggressive forms of treatment.
“We saw the use of AI assistance made doctors both more accurate and more consistent, meaning doctors tended to agree more when using AI assistance,” said Avenda Health co-founder and CEO Shyam Natarajan, PhD, who was senior author of the study.
“These results demonstrate a marked change in how physicians will be able to diagnose and recommend treatment for prostate cancer patients,” said Natarajan in a company press release. “By increasing the confidence in which we can predict a tumor’s margins, patients and their doctors will have increased certainty that their entire tumor is treated and with the appropriate intervention in correlation to the severity of their case.”
UCLA’s study found that AI can outperform doctors both in sensitivity (a higher detection rate of positive cancers) and specificity (correctly detecting the sample as negative). That’s relevant and worth watching for further developments.
Pathologists and clinical laboratory managers should consider this use of AI as one more example of how artificial intelligence can be incorporated into diagnostic tests in ways that allow medical laboratory professionals to diagnose disease earlier and more accurately. This will improve patient care because early intervention for most diseases leads to better outcomes.
Discovery could lead to new treatments for cancer and tumors, but probably not to any new diagnostic assays for clinical laboratories
Researchers at the University of Texas Southwestern (UTSW) Medical Center have reported discovery of “acid walls” that appear to protect various types of cancer tumors from attack by the body’s immune system cells. Though the discovery is not directly related to a biomarker for a clinical laboratory diagnostic test, the basic research will help scientists develop ways to address the tumor’s acid wall strategy for defeating the immune system.
The UT scientists made their discovery using an internally developed imaging technique that employs nanoparticle probes to detect levels of acidity in cells. The research, they suggest, “could pave the way for new cancer treatment approaches that alter the acidic environment around tumors,” according to a UTSW press release.
“This study revealed a previously unrecognized polarized extracellular acidity that is prevalent around cancer cells,” said lead study author Jinming Gao, PhD (above), Professor in the Harold C. Simmons Comprehensive Cancer Center and head of the Gao Lab at UT Southwestern Medical Center, in a press release. Gao believes the study “will lead to several new lines of research, such as studies to better understand how cancer cells polarize their acid excretion, how those cells can withstand the acidity level that kills CD8+ T cells, and how to inhibit acid excretion to allow T cells to better kill cancer cells,” the press release notes. (Photo copyright: University of Texas.)
Developing Acid Walls
As explained in the press release, scientists have long known that cancer cells are slightly more acidic than most healthy tissue. Gao and his team designed a nanoparticle known as pegsitacianine—a pH-sensitive fluorescent nanoprobe for image-guided cancer surgery—that disassembles and lights up when exposed to the acidic conditions in tumors.
However, “it was unclear why these nanoparticles fluoresced since a tumor’s acidity was thought to be too mild to trigger their activation,” the press release note.
To learn more, they used nanoparticle probes to illuminate a variety of individual cancer cells sampled from humans and mice, including lung, breast, melanoma, and glioblastoma, as well as tumor tissue. They discovered that the cancer cells secreted lactic acid—a waste product of digested glucose—at higher levels than previously known. The cells “pumped” the acid away from their malignant neighbors to form a protective “acid wall” around the tumor, the researchers noted in Nature Biomedical Engineering.
“Samples from human tumors showed that this acid wall was practically devoid of CD8+ T cells within the tumors, an immune cell type known to fight cancer,” the press release states. “When the researchers grew cancer cells and CD8+ T cells together in petri dishes that had been acidified to a 5.3 pH, the cancer cells were spared while the CD8+ T cells perished within three hours, suggesting that this severe acidity might thwart immune cell attack without harming the cancer cells.”
Gao’s team previously discovered that sodium lactate, the “conjugate base of lactic acid” as they describe it, increases the longevity of T cells and thus enhances their cancer-fighting capabilities. The researchers described the two molecules—lactate and lactic acid—as “Dr. Jekyll and Mr. Hyde,” and suggested that future therapies could seek to convert lactic acid to lactate.
“Gao noted that this discovery will lead to several new lines of research, such as studies to better understand how cancer cells polarize their acid excretion, how those cells can withstand the acidity level that kills CD8+ T cells, and how to inhibit acid excretion to allow T cells to better kill cancer cells,” the press release states.
Commercializing the Technology
Pegsitacianine was designed to aid cancer surgeons by illuminating the edges of solid metastatic tumors in real time during surgery, a 2023 UTSW Medical Center press release explains. About 24 hours prior to surgery, nanoprobes are delivered via IV. Then, the surgeon uses a near-infrared camera to visualize the cells.
UTSW has licensed pegsitacianine to OncoNano Medicine, a Dallas-area biotech startup launched to commercialize technologies from Gao Lab. Gao and his colleague Baran Sumer, MD, Professor and Chief of the Division of Head and Neck Oncology in UT Southwestern Medical Center’s Department of Otolaryngology and co-author on the study, both sit on OncoNano’s advisory board.
In January 2023, OncoNano announced that pegsitacianine had received Breakthrough Therapy Designation for Real-Time Surgical Imaging from the US Food and Drug Administration (FDA), which will fast-track the technology for development and regulatory review.
In a Phase II clinical trial published in the Annals of Surgical Oncology, the researchers tested the technology as part of cytoreductive surgery in patients with peritoneal metastases. However, a November 2023 UTSW press release noted that the technology is “tumor-agnostic and could potentially be used in other forms of cancer.” It is currently ready for Phase 3 trials, according to the OncoNano website.
More research and studies are needed to better understand this dynamic of cancer cells. Collectively, this research into cancer by different scientific teams is adding new insights into the way tumors originate and spread. At this time, these insights are not expected to lead to any new diagnostics tests that pathologists and clinical laboratories could use to detect cancer.
