Excess body sugar helps cancer tumors hide from the immune system

Cancer tumors use excess body sugar not only as fuel but to build a physical barrier that shields them from the immune system. Researchers from the Sanford Burnham Prebys Institute found that high glucose levels prompt tumor cells to develop a dense layer of carbohydrate molecules known as the glycocalyx. This "armor" renders the tumor invisible to T-killer cells and reduces the effectiveness of modern therapies.

The study identified the heat shock protein HSF1 as the molecular driver behind this mechanism. By isolating the role of HSF1, scientists have found a potential target for new drugs designed to "strip" cancer cells of their protection and restore the immune system's ability to attack the disease.

The Biochemical Shield and Tumor Microenvironment

While it was previously believed that reduced glucose oxidation in tumor zones resulted from internal defects in cancer cells, new evidence indicates that the process is dictated by the microenvironment—specifically connective tissue, blood vessels, and neighboring immune cells.

When excess sugar enters this aggressive environment, it triggers the thickening of the glycocalyx. This layer becomes sufficiently powerful to physically block antibodies and immune cells from reaching receptors on the surface of the tumor. This mechanism explains why conditions such as diabetes and prediabetes often complicate the course of oncological diseases.

Experiments demonstrated that in conditions simulating normal tissues, cells do not build this carbohydrate barrier even when sugar is abundant. The reaction occurs only in a specific "tumor broth" characterized by cell stress and oxygen deficiency.

The Role of Protein HSF1

The heat shock protein HSF1 acts as the coordinator for the construction of the "sugar shield." While previously known for protecting cells from overheating and stress, as well as its link to metastasis in breast cancer, it has now been revealed that HSF1 activates the genes responsible for glycocalyx synthesis during hyperglycemia.

Without this protein, cancer cells remain vulnerable regardless of surrounding sugar levels. This finding is critical for pharmacological development, particularly since hidden sugars in food products can maintain the activity of such proteins unnoticed.

Treatment Strategies and Metabolic Control

Researchers believe that thinning the sugar coating will restore the visibility of tumors for T-cells, which is especially relevant for aggressive cancer forms that quickly develop resistance to treatment. While scientists seek ways to safely inhibit HSF1, medical experts recommend strict control of the glycemic index.

Excessive consumption of natural honey or dried fruits can create a metabolic background favorable for the masking of cancer cells if the process has already begun. Aleksey Dorofeev, a nutritionist, noted that regulating carbohydrate intake creates less comfortable conditions for tumor defense, thereby increasing the efficiency of primary treatment.

Questions about Sugar and Cancer Defense

How does sugar help cancer hide?

Excess sugar is processed by cancer cells into complex carbohydrate chains that form a thick "crust" on the cell surface, physically blocking immune cells from accessing the tumor.

Why is the discovery of HSF1 significant?

It provides a specific molecular target. A drug that blocks HSF1 could potentially remove the protective sugar layer from the tumor without affecting healthy organs.

Does diet affect immunotherapy efficiency?

The research suggests that high blood glucose levels can hinder treatment by preventing the removal of masking barriers or encouraging their creation.

Is this mechanism present in all types of cancer?

This process is most pronounced in solid tumors with a rigid microenvironment, such as breast cancer, where HSF1 shows maximum activity.

Source: This article was adapted from an original Russian-language publication by Pravda.Ru.