Lukas Chavez Archives - Sanford Burnham Prebys
Institute News

Coding clinic

AuthorGreg Calhoun
Date

August 6, 2024

Rapidly evolving computational tools may unlock vast archives of untapped clinical information—and help solve complex challenges confronting healthcare providers

The wealth of data stored in electronic medical records has long been considered a veritable treasure trove for scientists able to properly plumb its depths.  

Emerging computational techniques and data management technologies are making this more possible, while also addressing complicated clinical research challenges, such as optimizing the design of clinical trials and quickly matching eligible patients most likely to benefit.  

Scientists are also using new methods to find meaning in previously published studies and creating even larger, more accessible datasets.  

“While we are deep in the hype cycle of artificial intelligence [AI] right now, the more important topic is data,” says Sanju Sinha, PhD, an assistant professor in the Cancer Molecular Therapeutics Program at Sanford Burnham Prebys. “Integrating data together in a clear, structured format and making it accessible to everyone is crucial to new discoveries in basic and clinical biomedical research.” 

Sinha is referring to resources such as the  St. Jude-Washington University Pediatric Cancer Genome Project, which makes available to scientists whole genome sequencing data from cancerous and normal cells for more than 800 patients.

Medulloblastoma tumor cells with hundreds of circular DNA pieces

The Chavez lab uses fluorescent markers to observe circular extra-chromosomal DNA elements floating in cancer cells. Research has shown that these fragments of DNA are abundant in solid pediatric tumors and associated with poor clinical outcomes. Image courtesy of Lukas Chavez.

The Children’s Brain Tumor Network is another important repository for researchers studying pediatric brain cancer, such as Lukas Chavez, PhD, an assistant professor in the Cancer Genome and Epigenetics Program at Sanford Burnham Prebys. 

“We have analyzed thousands of whole genome sequencing datasets that we were able to access in these invaluable collections and have identified all kinds of structural rearrangements and mutations,” says Chavez. “Our focus is on a very specific type of structural rearrangement called circular extra-chromosomal DNA elements.” 

Circular extra-chromosomal DNA elements (ecDNA) are pieces of DNA that have broken off normal chromosomes and then been stitched together by DNA repair mechanisms. This phenomenon leads to circular DNA elements floating around in a cancer cell.  

Sanju Sinha, PhD

Sanju Sinha, PhD, is an assistant professor in the Cancer Molecular
Therapeutics Program at  Sanford Burnham Prebys.

“We have shown that they are much more abundant in solid pediatric tumors than we previously thought,” adds Chavez. “And we have also shown that they are associated with very poor outcomes.” 

To help translate this discovery for clinicians and their patients, Chavez is testing the use of deep learning AI algorithms to identify tumors with ecDNA by analyzing the biopsy slides that are routinely created by pathologists to diagnose brain cancer. 

“We have already done the genomic analysis, and we are now turning our attention to the histopathological images to see how much of the genomic information can be predicted from these images,” says Chavez. “Our hope is that we can identify tumors that have ecDNA by evaluating the images without having to go through the genomic sequencing process.”  

Currently, this approach serves only as a clinical biomarker of a challenging prognosis, but Chavez believes it can also be a diagnostic tool—and a game changer for patients.  

“I’m optimistic that in the future we will have drugs that target these DNA circles and improve the therapeutic outcome of patients,” says Chavez.  

“Once medicine catches up, we need to be able to find the patients and match them to the right medicine,” says Chavez. “We’re not there yet, but that’s the goal.” 

Chavez is also advancing his work as scientific director of the Pediatric Neuro-Oncology Molecular Tumor Board at Rady Children’s Hospital in San Diego.  

“Recently, it has been shown that new sequencing technologies coupled with machine learning tools make it possible to compress the time it takes to sequence and classify types of tumors from days or weeks to about 70 minutes,” says Chavez. “This is quick enough to take that technology into the operating room and use a surgical biopsy to classify a tumor.  

“Then we could get feedback to the surgeon in real time so that more or less tissue can be removed depending on if it is a high- or low-grade tumor—and this could dramatically affect patient outcomes.  

“When I talk to neurosurgeons, they are always in a pickle between trying to be aggressive to reduce recurrence risk or being conservative to preserve as much cognitive function and memory as possible for these patients.  

“If the surgeon knows during surgery that it’s a tumor type that’s resistant to treatment versus one that responds very favorably to chemotherapy, radiation or other therapies, that will help in determining how to strike that surgical balance.” 

Lukas Chavez, PhD

Lukas Chavez, PhD, is an assistant professor in the Cancer Genome and Epigenetics Program at Sanford Burnham Prebys.

Artist’s rendering X-shaped chromosomes floating in a cell

Artist’s rendering of X-shaped chromosomes floating in a cell alongside circular extra-chromosomal DNA elements.

Rady Children’s Hospital has also contributed to the future of genomic and computational medicine through BeginNGS, a pilot project to complement traditional newborn health screening with genomic sequencing that screens for approximately 400 genetic conditions. 

“The idea is that if there is a newborn baby with a rare disease, their family often faces a very long odyssey before ever reaching a diagnosis,” says Chavez. “By sequencing newborns, this program has generated success stories, such as identifying genetic variants that have allowed the placement of a child on a specific diet to treat a metabolic disorder, and a child to receive a gene therapy to restore a functional immune system.”


Programming in a Petri Dish, an 8-part series

How artificial intelligence, machine learning and emerging computational technologies are changing biomedical research and the future of health care

  • Part 1 – Using machines to personalize patient care. Artificial intelligence and other computational techniques are aiding scientists and physicians in their quest to prescribe or create treatments for individuals rather than populations.
  • Part 2 – Objective omics. Although the hypothesis is a core concept in science, unbiased omics methods may reduce attachments to incorrect hypotheses that can reduce impartiality and slow progress.
  • Part 3 – Coding clinic. Rapidly evolving computational tools may unlock vast archives of untapped clinical information—and help solve complex challenges confronting health care providers.
  • Part 4 – Scripting their own futures. At Sanford Burnham Prebys Graduate School of Biomedical Sciences, students embrace computational methods to enhance their research careers.
  • Part 5 – Dodging AI and computational biology dangers. Sanford Burnham Prebys scientists say that understanding the potential pitfalls of using AI and other computational tools to guide biomedical research helps maximize benefits while minimizing concerns.
  • Part 6 – Mapping the human body to better treat disease. Scientists synthesize supersized sets of biological and clinical data to make discoveries and find promising treatments.
  • Part 7 – Simulating science or science fiction? By harnessing artificial intelligence and modern computing, scientists are simulating more complex biological, clinical and public health phenomena to accelerate discovery.
  • Part 8 – Acceleration by automation. Increases in the scale and pace of research and drug discovery are being made possible by robotic automation of time-consuming tasks that must be repeated with exhaustive exactness.
Institute News

Using machines to personalize patient care

AuthorGreg Calhoun
Date

July 30, 2024

Artificial intelligence (AI) and other computational techniques are aiding scientists and physicians in their quest to create treatments for individuals rather than populations

The Human Genome Project captured the public’s imagination with its global quest to better understand the genetic blueprint stored on the DNA within our cells. The project succeeded in delivering the first-ever sequence of the human genome while foreshadowing a future for medicine once considered to be science fiction. The project presaged the possibility that health care could be personalized based on clues within a patient’s unique genetic code.

Chavez lab

The Chavez Lab

While many more people have undergone genetic testing through consumer genealogy and health services such as 23andMe and Ancestry than through health care systems, genomic sequencing has influenced clinical care in some specialties. Personalized medicine—also known as precision medicine or genomic medicine—has been especially helpful for people suffering from rare diseases that historically have been difficult to diagnose and treat.

Scientists at Sanford Burnham Prebys are employing new technologies and expertise to test ways to improve diagnoses and customize treatments for many diseases based on unique characteristics within tumors, blood samples and other biopsies.

AI and other computational techniques are enabling patient samples to be rapidly analyzed and compared to data from vast numbers of individuals who have been treated for the same condition. Physicians can use AI and other tools to identify subtypes of cancers and other conditions, as well as improve selection of eligible candidates for clinical trials.

“I think we’ve gotten a lot better at precision diagnostics,” says Lukas Chavez, PhD, an assistant professor in the Cancer Genome and Epigenetics Program at Sanford Burnham Prebys. “In my work at Rady Children’s Hospital in cancer, we can characterize a tumor based on mutations, including predicting how quickly different tumors will spread. What we too often lack, however, are better treatment approaches or medicines. That will be the next generation of precision medicine.”

Sanju Sinha, PhD, an assistant professor in the Cancer Molecular Therapeutics Program at Sanford Burnham Prebys, is developing projects to help bridge the gap between precision diagnostics and treatment. He is partnering with the National Cancer Institute on a first-of-its-kind computational tool to systematically predict patient response to cancer drugs at single-cell resolution.

A study published in the journal  Nature Cancer discussed how the tool, called PERCEPTION, was successfully validated by predicting the response to individual therapies and combination treatments in three independent published clinical trials for multiple myeloma, breast and lung cancer.

Lukas Chavez, PhD

Lukas Chavez, PhD, is an assistant professor in the Cancer Genome and Epigenetics Program at Sanford Burnham Prebys.

In each case, PERCEPTION correctly stratified patients into responder and non-responder categories. In lung cancer, it even captured the development of drug resistance as the disease progressed, a notable discovery with great potential.

Sanju Sinha, PhD

Sanju Sinha, PhD, is an assistant professor in the Cancer Molecular
Therapeutics Program at Sanford Burnham Prebys.

“The ability to monitor the emergence of resistance is the most exciting part for me,” says Sinha. “It has the potential to allow us to adapt to the evolution of cancer cells and even modify our treatment strategy.”

While PERCEPTION is not yet ready for clinics, Sinha hopes that widespread adoption of this technology will generate more data, which can be used to further develop and refine the technology for use by health care providers.

In another project, Sinha is focused on patients being treated for potential cancers that may never progress into dangerous conditions warranting treatment and its accompanying side effects.

“Many women who are diagnosed with precancerous changes in the breast seek early treatment,” says Sinha. “Most precancerous cells never lead to cancer, so it may be that as many as eight of 10 women with this diagnosis are being overtreated, which is a huge issue.”

To try and counter this phenomenon, Sinha is training AI models on images of biopsied samples in conjunction with multi-omics sequencing data. His team’s goal is to develop a tool capable of predicting which patients’ cancers would progress based on the imaged samples alone.

“In the field of precancer, insurance does not cover the cost of computing this omics data,” says Sinha. “Health care systems do routinely generate histopathological slides from patient biopsies, so we feel that a tool leveraging these images could be a scalable and accessible solution.”

If Sinha’s team is successful, an AI tool integrated into clinics would predict whether precancerous cells would progress within the next 10 years to guide treatment decisions and how patients are monitored.

“With precision medicine, our hope is not to just treat patients with better drugs, but also to make sure that patients are not unnecessarily treated and made to bear needless costs and side effects that disrupt their quality of life.”


Programming in a Petri Dish, an 8-part series

How artificial intelligence, machine learning and emerging computational technologies are changing biomedical research and the future of health care

  • Part 1 – Using machines to personalize patient care. Artificial intelligence and other computational techniques are aiding scientists and physicians in their quest to prescribe or create treatments for individuals rather than populations.
  • Part 2 – Objective omics. Although the hypothesis is a core concept in science, unbiased omics methods may reduce attachments to incorrect hypotheses that can reduce impartiality and slow progress.
  • Part 3 – Coding clinic. Rapidly evolving computational tools may unlock vast archives of untapped clinical information—and help solve complex challenges confronting health care providers.
  • Part 4 – Scripting their own futures. At Sanford Burnham Prebys Graduate School of Biomedical Sciences, students embrace computational methods to enhance their research careers.
  • Part 5 – Dodging AI and computational biology dangers. Sanford Burnham Prebys scientists say that understanding the potential pitfalls of using AI and other computational tools to guide biomedical research helps maximize benefits while minimizing concerns.
  • Part 6 – Mapping the human body to better treat disease. Scientists synthesize supersized sets of biological and clinical data to make discoveries and find promising treatments.
  • Part 7 – Simulating science or science fiction? By harnessing artificial intelligence and modern computing, scientists are simulating more complex biological, clinical and public health phenomena to accelerate discovery.
  • Part 8 – Acceleration by automation. Increases in the scale and pace of research and drug discovery are being made possible by robotic automation of time-consuming tasks that must be repeated with exhaustive exactness.
Institute News

Seminar Series: extrachromosomal DNA and the metabolic circuits of cancer immune suppression

AuthorScott LaFee
Date

March 25, 2024

The ongoing Sanford Burnham Prebys seminar series will feature a pair of speakers on March 27, from noon to 1p.m., in the Fishman Auditorium. They will be presenting on two topics: extrachromosomal DNA and the tumor microenvironment.

First, Owen Chapman, PhD, a postdoctoral research scientist in the lab of Lukas Chavez, PhD, will discuss clinical and genomic features of circular extrachromosomal DNA (ecDNA) in medulloblastomas, a type of brain tumor.

EcDNA is DNA found off chromosomes, either inside or outside the nucleus of a cell. In a study published last year, Chavez (senior author), Chapman (first author) and colleagues reported that patients with medulloblastomas containing ecDNA are twice as likely to relapse after treatment and three times as likely to die within five years of diagnosis.

The second presentation will be by Kevin Tharp, PhD assistant professor in the Cancer Metabolism and Microenvironment Program. Tharp, who joined Sanford Burnham Prebys in December 2023, studies how tumors manipulate their mitochondria to improve survivability and how those cellular mechanics can be leveraged to create more effective therapies.

Institute News

Padres Pedal the Cause 2023: Team Sanford Burnham Prebys raises $50,000 for cancer research

AuthorMiles Martin
Date

March 20, 2023

Team Sanford Burnham Prebys hit the pavement this weekend for Padres Pedal the Cause, an annual fundraising event that invites participants to cycle, spin, run or walk to support local cancer research. The funds raised through each year’s race go to seed grants that fund collaborative cancer research projects in San Diego.

“Padres Pedal the Cause is a chance for the cancer community to come together and remember why collaboration is so important in cancer research,” says bike rider Ze’ev Ronai, PhD, director of the Institute’s NCI-designated Cancer Center. “Virtually all of us know somebody who has been impacted by cancer, including me. This is my fifth Padres Pedal the Cause, and every year I’m so proud to be part of our Institute’s team and help contribute to cancer research outside the lab.”

This year’s team was formidable: 56 employees and friends of the Institute signed up to either ride, run, or walk in the event. Team members came from all areas of the Institute, including faculty, staff scientists, administrative staff, postdocs, and even current and former members of the Institute’s Board of Trustees, such as Bill Gerhart and Steve Williams. Other notable names on this year’s team included longtime participants such as Professor Nicholas Cosford, PhD and James Short, associate director of Digital Communications and Design. 

“I’ve been with Padres Pedal the Cause since the very beginning, and it’s one of the highlights of my year,” says Short, who has helped lead the Institute’s team for the last 10 years.

The team also included some new members this year, such as Assistant Professor Lukas Chavez, PhD, and Director of Experimental Pharmacology Raghu Ramachandra, PhD, who both joined the Institute late last year. 

While Institute employees were well represented on this year’s team, there were also current some of the team’s top fundraisers had a different reason to join team Sanford Burnham Prebys. Kim McKewon is a longtime donor to the Institute and has been participating in Padres Pedal the Cause since its inception in 2013. This year she raised more than $6,000; and to date, she has raised more than $30,000. 

“I pedal for my husband, Ray, who is in remission from leukemia because of science and research, the very focus of the grants that are given from the fundraising that comes out of this event,” she writes in her website bio.

It’s not too late to support Team Sanford Burnham Prebys
To date, team Sanford Burnham Prebys has raised more than $300,000 through Padres Pedal the Cause since its inception in 2013. And while this year’s ride is over, there is always time to support local cancer research. The fundraising deadline for this year’s Padre’s Pedal the Cause is April 18, and 100% of every dollar raised goes toward lifesaving cancer research. Help team Sanford Burnham Prebys create a world without cancer.

Support Team Sanford Burnham Prebys

 

 

Institute News

Sanford Burnham Prebys researchers awarded Curebound grants

AuthorMiles Martin
Date

March 20, 2023

Each year, Sanford Burnham Prebys joins Padres Pedal the Cause, an annual fundraising event that raises money for Curebound which awards collaborative cancer grants in the San Diego area.

These grants include Discovery Grants, which provide seed funds for high-risk/high-reward research in the earliest phases, and Targeted Grants, which are larger awards ($500K) that help translate promising discoveries into treatments for the clinic.

In the 2022-2023 Curebound Research portfolio, five researchers from Sanford Burnham Prebys were awarded grants: Associate Professor Anindya Bagchi, PhD, Professor Linda Bradley, PhD, Assistant Professor Lukas Chavez, PhD, Professor Nicholas Cosford, PhD, and Professor Michael Jackson, PhD

2022 Discovery Grant: Treating incurable pediatric brain tumors 
Bagchi and Chavez will collaborate to advance a new therapeutic approach for medulloblastoma, the most common childhood brain tumor. They will be focusing on a gene called MYC, found only in the deadliest forms of medulloblastoma. This form of brain cancer is currently untreatable, but Bagchi and Chavez recently discovered a molecule that can help control the activity of the MYC gene and potentially inhibit the growth of medulloblastoma tumors. The researcher holds promise to reveal a new treatment approach for this incurable cancer. 

The grant is titled “Decoding the Role of the Long Non-Coding RNA PVT1 in Medulloblastoma.”

2023 Targeted Grant: Discovering a new immunotherapy drug for melanoma
Bradley will be working with Soo Jin Park, MD, from UC San Diego Health to advance a new immunotherapy approach for malignant melanoma. Despite recent advances, this type of skin cancer still causes thousands of deaths in the U.S. each year. The goal of their project is to develop a new drug for melanoma that can reactivate the tumor-killing properties of the patient’s own immune system. This therapeutic approach has the potential to destroy tumors that are resistant to existing therapies, which could help save lives.

The grant is titled, “Advancing Immune Checkpoint Inhibition of PSGL-1 for Treatment of Malignant Melanoma.
 

2022 Discovery Grant: Developing drugs for bone-metastatic prostate cancer
Cosford will work with Christina Jamieson, PhD, from the University of California, San Diego, to advance a new treatment approach for prostate cancer that has spread to the bones. Bone is the most common place for prostate cancer to metastasize, and this form of cancer is currently incurable. The researchers will look for drugs that can kill tumor cells by inhibiting autophagy, a process that promotes tumor progression. The results of the study could identify a new drug ready for clinical trials.

The grant is titled “Pre-Clinical Development of New Autophagy Targeting Drugs for Bone Metastatic Prostate Cancer.”

2022 Discovery Grant: Repurposing drugs for deadly childhood brain cancer
Jackson and Chavez will collaborate to identify new treatment options for ependymoma, an aggressive pediatric brain tumor and leading cause of death among childhood cancer patients. The researchers will screen patient tumor cells against drugs already approved by the FDA for other conditions, looking for drugs that could be repurposed to fight these tumors. Because FDA-approved drugs are known to be safe for humans, this may prove to be the quickest way to help patients currently living with this cancer. 

The grant is titled “High Throughput-Screen for Inhibitors of Pediatric Ependymoma.”

Institute News

Is cloud computing a game changer in cancer research? Three big questions for Lukas Chavez

AuthorMiles Martin
Date

February 22, 2023

As an assistant professor at Sanford Burnham Prebys and director of the Neuro-Oncology Molecular Tumor Board at Rady Children’s Hospital, Lukas Chavez, PhD, leverages modern technology for precision diagnostics and for uncovering new treatment options for the most aggressive childhood brain cancers.

We spoke to Chavez about his work and asked him how modern technology—particularly cloud computing—is shifting the approach to cancer research.

How are you using new technologies to advance your research?

New technologies are helping us generate a huge amount of data as well as many new types of data. All this new information at our disposal has created a pressing need for tools to make sense of it and maximize their benefits. That’s where computational biology and bioinformatics come into play. The childhood brain cancers I work on are very rare, which has historically made it difficult to study large numbers of cases and identify patterns.

Now, data for thousands of cases can be stored in the cloud. By creating data analysis tools, we can reveal insights that we would never have seen otherwise. For example, we’ve developed tools that can use patient data in the cloud to categorize brain cancers into subtypes we’ve never identified before, and we’re learning that there are many more types of brain tumors than we’ve previously understood. We’re basically transforming the classic histo-pathological approach that people have studied for decades by looking at tumor tissues under the microscope and turning that into data science.

How is cloud computing improving cancer research in general?

Assembling big datasets delays everything, so I believe the main idea of cloud computing is really to store data in the cloud, then bring the computational tools to the data, not the other way around.

My team did one study where we assembled publicly available data, and basically downloaded everything locally. The data assembly process alone took at least two to three years because of all the data access agreements and legal offices that were involved.

And that is the burden that cloud computing infrastructures remove. All of this personalized cancer data can be centrally stored in the cloud, which makes it available to more researchers while keeping it secure to protect patient privacy. Researchers can get access without downloading the data, so they are not responsible for data protection anymore. It’s both faster and more secure to just bring your tools to the data.

Are there any risks we need to be aware of?

Like any new technology, we need to be clear about how we use it. The technology is another tool in the toolbox of patient care. It will never entirely replace physicians and researchers, but it can complement and assist them.

Also, because we use costly and sophisticated tools that are being built and trained on very specific patient groups, we need to be careful that these tools are not only helping wealthier segments of society. Ideally, these tools will be expanded worldwide to help everybody affected by cancer.