Pancreatic cancer has a reputation for being one of the deadliest cancers, and a new study helps explain why. Researchers at NYU Langone Health and its Perlmutter Cancer Center have shown that pancreatic cancer cells are not static. Instead, they continually rewrite their DNA and adjust their behavior to become more aggressive, spread more easily, and evade treatment. This deeper look at clonal heterogeneity in human pancreatic ductal adenocarcinoma helps clarify why the disease so often resists therapy and why new strategies targeting tumor evolution itself may be needed.

The study focused on pancreatic ductal adenocarcinoma, the most common type of pancreatic cancer and one that remains extremely difficult to treat. Nearly 85 percent of people diagnosed with this cancer die within five years, despite advances in surgery, chemotherapy, and radiation. Researchers have known that several genes are frequently mutated in pancreatic tumors, but the picture of how those tumors grow, adapt, and respond to therapy has been incomplete. By shifting from bulk analysis to single-cell analysis, the team was able to see the internal diversity of tumors with far greater clarity.

Instead of treating a tumor as a uniform mass, the investigators examined 443,451 individual cells from 62 tumors taken from 56 patients with pancreatic ductal adenocarcinoma. Six of these patients contributed samples both before and after chemotherapy. The researchers used transcriptomics, which measures gene activity, to see which genes each cell had turned on or off. This approach revealed that each tumor was more like an ecosystem than a single entity, with between two and eleven distinct groups of cancer cells that shared genetic traits yet behaved differently.

These genetically related cell populations, known as clones, emerged as key drivers of pancreatic cancer behavior. Some clones developed changes that allowed them to survive chemotherapy or other treatments. Others acquired traits that made them better at invading nearby tissue and metastasizing to distant organs. In other words, tumor evolution was not a single, uniform process. Different clones within the same tumor were following their own paths, shaped by the genetic rearrangements they accumulated over time.

Previous research had divided pancreatic cancer cells into two main categories known as classical and basal. Classical cells tend to be less aggressive and somewhat more treatable. Basal cells are more aggressive, more resistant to therapy, and linked with poorer outcomes. Earlier studies, which mostly analyzed large groups of mixed cells, left an important question unanswered. How do cancer cells move from a classical state to a basal state as disease progresses?

This new work helps fill that gap. By tracking gene activity and DNA copy number changes in individual cells, the researchers showed that tumors do not fall neatly into just one category. Instead, they contain mixtures of classical and basal clones. Over time, ongoing genetic reshaping enables cells to shift between these states. Certain clones gradually acquire features of the more aggressive basal type, making the cancer harder to control. I found this detail striking because it suggests that a single tumor is not locked into one identity. It is constantly experimenting at the genetic level, and some of those experiments give rise to more dangerous forms.

One of the most notable findings involved the gene MYC. The study reported that MYC was especially active in some of the most aggressive basal cancer cell populations. MYC is known in cancer biology as a powerful regulator of cell growth and metabolism. In this context, heightened MYC activity appeared to be a hallmark of highly aggressive pancreatic cancer clones. The researchers then tested what would happen if they interfered with MYC in these cells.

In laboratory experiments, blocking MYC activity in aggressive basal cells pushed them back toward a more classical, less aggressive state. This shift was more than a subtle molecular adjustment. It made the cancer cells appear more visible to the immune system, suggesting that they might be easier for immune cells to recognize and potentially attack. This is important because pancreatic cancer has historically responded poorly to immunotherapy. Anything that makes tumor cells more vulnerable to immune surveillance could open the door to new therapeutic strategies.

These results highlight MYC as a promising target in pancreatic ductal adenocarcinoma. Clinical trials evaluating drugs that inhibit MYC in various cancers are already underway, and the study suggests that such approaches may be especially relevant for tumors dominated by aggressive basal clones. While further research is clearly needed, the findings support the idea that changing the internal state of cancer cells could be just as critical as killing them outright.

The investigation also shed light on how pancreatic cancer evades the immune system, another major obstacle in treatment. The researchers found that certain clones showed increased activity of the TIGIT gene, which is linked to proteins that help tumors escape immune detection. At the same time, these clones displayed reduced activity of the PD1 gene. Many existing immunotherapies focus on blocking PD1, yet pancreatic cancer has typically shown limited benefit from PD1 inhibitors. The pattern observed in this study helps explain why. If the most relevant clones rely more on TIGIT and less on PD1 to avoid the immune system, then drugs that only target PD1 will not fully address the ways these tumors hide.

Understanding these distinct immune evasion strategies at the clonal level suggests that therapies might need to be tailored not only to a patient’s overall tumor type, but also to the specific mix of clones present. Treatments that inhibit TIGIT, for instance, are already being tested in clinical trials. Combining such approaches with agents that influence genes like MYC might help shift aggressive cancer cells into more treatable states while reducing their ability to stay invisible to immune defenses.

Beyond specific genes, the broader message from the study is that clonal diversity and genetic plasticity are central to pancreatic tumor biology. The cancer’s ability to rearrange its DNA and alter gene activity allows it to adapt to each new challenge, whether that challenge is chemotherapy, the body’s immune response, or changes in the surrounding tissue environment. The microenvironment of the tumor, including blood vessels, immune cells, and connective tissue, interacts with these diverse clones in complex ways, further shaping how the disease behaves.

Single-cell clonal analysis, as used in this work, offers a powerful way to map these dynamics over time. By examining how individual clones emerge, expand, or recede in response to treatment, researchers can identify which genetic changes matter most during each stage of disease progression. This level of detail may eventually guide more precise treatment strategies. For example, clinicians might one day use similar profiling approaches to determine whether a patient’s tumor is driven by MYC-high basal clones, TIGIT-active immune evasive clones, or other specific populations that call for particular combinations of drugs.

For now, the findings give a more granular picture of why pancreatic ductal adenocarcinoma is so challenging to treat and where new vulnerabilities might lie. Targeting the mechanisms that underlie tumor evolution, as well as the genes that enable immune escape, could help restrain the rapid progression that has long characterized this disease. The study’s emphasis on clonal heterogeneity, genetic plasticity, and tumor microenvironment interactions underscores the importance of looking beyond single mutations and considering the tumor as a diverse and changing community of cells.

Read more at https://www.sciencedaily.com/releases/2026/10/261024221849.htm