Researchers found that people with colorectal cancer have higher levels of a natural body protein called LL-37 in their colon tissue compared to healthy people. The study looked at 25 cancer tissue samples and found that patients with more advanced cancer had even higher levels of this protein. The protein appears to work with other molecules in the body that might help tumors grow and spread. While this discovery is interesting, scientists say they need more research to fully understand how this protein works and whether it could become a target for new cancer treatments.

The Quick Take

  • What they studied: Whether a natural body protein called LL-37 is present in higher amounts in colorectal cancer tissue and if it’s connected to cancer spreading
  • Who participated: 25 people with colorectal cancer whose tumor tissue was compared to healthy colon tissue from the same patients
  • Key finding: Cancer tissue had significantly more LL-37 protein than healthy tissue (p<0.001), and patients with advanced cancer or cancer that spread to lymph nodes had even higher levels
  • What it means for you: This research suggests LL-37 may play a role in helping colorectal cancer progress, but it’s too early to use this information for treatment decisions. Talk to your doctor about colorectal cancer screening and prevention based on current guidelines

The Research Details

Scientists collected colon tissue samples from 25 colorectal cancer patients and compared them to healthy tissue from the same patients. They used a laboratory technique called quantitative real-time PCR to measure how much LL-37 protein was present in each sample. They also measured several other proteins that might work together with LL-37. Finally, they looked at whether the amount of LL-37 was connected to how advanced the cancer was and whether it had spread to nearby lymph nodes.

This type of study is called a tissue analysis study. Researchers examine actual human tissue to understand what’s happening at the molecular level in disease. It’s an important first step in understanding how cancer develops, but it doesn’t tell us whether changing LL-37 levels would actually help treat cancer.

The researchers focused on understanding the connections between LL-37 and other molecules in the body, particularly ones that help cells communicate with each other. This approach helps scientists figure out the biological pathways involved in cancer growth.

Understanding which proteins are involved in cancer progression is crucial for developing new treatments. By identifying that LL-37 is elevated in colorectal cancer, researchers can investigate whether blocking this protein might slow cancer growth. This type of foundational research helps scientists decide which new drug targets are worth pursuing.

This study has both strengths and limitations. The strength is that researchers used a precise laboratory method to measure protein levels and found clear differences between cancer and healthy tissue. However, the sample size of 25 patients is relatively small, which means the findings need to be confirmed in larger studies. The study shows association (that LL-37 is higher in cancer) but doesn’t prove that LL-37 actually causes cancer to grow. More research is needed to understand the cause-and-effect relationship.

What the Results Show

The main finding was that LL-37 protein levels were significantly higher in colorectal cancer tissue compared to normal colon tissue. This difference was very clear statistically (p<0.001, meaning there’s less than a 0.1% chance this happened by random chance).

When researchers looked at cancer stage, they found that patients with more advanced cancer (stage III) had even higher LL-37 levels than those with earlier-stage cancer. Similarly, patients whose cancer had spread to lymph nodes had higher LL-37 levels than those without lymph node involvement (p=0.006).

The researchers also discovered changes in other proteins that work with LL-37. Specifically, a protein called FPR2 was increased in cancer tissue, while another protein called TLR3 was decreased. These changes suggest that LL-37 might be communicating with cancer cells through FPR2 and that the loss of TLR3 might remove a natural brake on tumor growth.

The study examined several other proteins that could interact with LL-37, including TLR4, CXCR2, and MrgX2. While the main focus was on FPR2 and TLR3, these other proteins may also play roles in how LL-37 affects cancer cells. The researchers noted that understanding these multiple pathways is important because LL-37 appears to have complex effects that depend on which proteins it interacts with.

Previous research on LL-37 has shown conflicting results—sometimes it appears to protect against cancer, and other times it seems to promote cancer growth. This study adds to the evidence that in colorectal cancer specifically, LL-37 may promote tumor progression. The researchers acknowledge that LL-37’s role varies depending on the type of cancer and the specific biological context, which explains why earlier studies reached different conclusions.

The study is limited by its small sample size of 25 patients, which means the findings need to be confirmed in larger groups. The research only shows that LL-37 levels are associated with cancer progression, not that LL-37 actually causes cancer to grow—this would require additional experiments. The study examined tissue samples at one point in time rather than following patients over time to see how LL-37 levels change. Additionally, the research was conducted in laboratory conditions, and results in living patients might differ. Finally, the study doesn’t explain the exact mechanisms by which LL-37 promotes cancer, only that it appears to be involved.

The Bottom Line

Based on this research alone, there are no new recommendations for colorectal cancer prevention or treatment. However, this finding supports the importance of following standard colorectal cancer screening guidelines (colonoscopy starting at age 45-50 for average-risk adults). If you have a family history of colorectal cancer or other risk factors, discuss screening with your doctor. This research may eventually lead to new treatments, but that’s years away.

This research is most relevant to colorectal cancer researchers and oncologists who are developing new treatments. People with colorectal cancer or a family history of colorectal cancer should be aware that scientists are actively investigating new targets for treatment. The general public should focus on proven prevention strategies like screening, healthy diet, exercise, and avoiding smoking.

This is early-stage research. Even if LL-37 becomes a treatment target, it typically takes 10-15 years from basic research discovery to a new drug being available to patients. This study is an important first step, but many more studies are needed before any clinical applications.

Want to Apply This Research?

  • Track colorectal cancer risk factors: record family history updates, screening dates, and any digestive symptoms. Note dates of colonoscopies or other cancer screenings to ensure you stay current with recommended intervals.
  • Use the app to set reminders for colorectal cancer screening appointments based on your age and risk factors. Create a log of lifestyle factors associated with colorectal cancer prevention: weekly servings of vegetables, fiber intake, exercise minutes, and smoking status.
  • Maintain a long-term record of all cancer screenings and results. If you have colorectal cancer, track any new research findings about LL-37 and discuss them with your oncologist at regular appointments. Monitor digestive health symptoms and report changes to your healthcare provider.

This research is preliminary and does not provide guidance for cancer treatment or prevention. If you have been diagnosed with colorectal cancer or have concerns about your risk, consult with an oncologist or gastroenterologist. Do not make any changes to cancer treatment based on this research. Current colorectal cancer screening and prevention recommendations should be followed as advised by your healthcare provider. This article is for educational purposes only and should not be considered medical advice.