Distance-Dependent Distribution of Biomarkers in Colorectal Cancer Tissues: In Vivo Study

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Colorectal cancer (CRC) is a leading cause of cancer-related deaths globally.
• Metastasis and aggressive tumor progression in CRC present significant clinical challenges.
• Understanding the spatial distribution of biomarkers is crucial for elucidating CRC invasion mechanisms.

Purpose of the Study:

• To investigate the location-dependent expression of cathepsins B and D, and actin isoforms in colorectal cancer tissues.
• To correlate spatial biomarker expression patterns with colorectal cancer progression and invasion.

Main Methods:

• Tissue samples were collected from 37 CRC patients at the tumor center and at 2 cm and 5 cm from the margin.
• Biochemical and spectrophotometric assays were used to measure cathepsin B and D activity, anti-papain activity, and actin fractions (G-actin, F-actin, T-actin).
• Statistical analyses included ANOVA, MANOVA, and non-parametric tests to assess significance (p < 0.05).

Main Results:

• Cathepsin B activity was significantly higher in the tumor center, decreasing with distance (p < 0.001).
• Filamentous actin (F-actin) and total actin (T-actin) levels were also elevated near the tumor core (p < 0.05).
• Significant alterations in actin polymerization states were observed based on proximity to the tumor, while cathepsin D and anti-papain activity showed no significant spatial variation.

Conclusions:

• Spatial heterogeneity in biomarker expression exists within colorectal cancer tissues.
• Elevated cathepsin B and altered actin dynamics in tumor regions suggest their critical role in local invasion and CRC progression.