Circulating exosomes are extracellular vesicles released by multiple cell types and have emerged as accessible sources of cancer biomarkers. In patients with head and neck cancer (HNC), these vesicles may reflect the tumor microenvironment and carry messenger RNAs associated with disease progression. The chaperone encoded by ERP29 participates in protein folding and trafficking within the endoplasmic reticulum, contributing to cellular homeostasis. Its suppression has been associated with activation of MAPK and Akt signaling pathways involved in cell proliferation. However, the expression of ERP29 in circulating exosomes from HNC patients remains unknown. This pilot study investigated the presence and expression of ERP29 transcripts in plasma-derived exosomes from HNC patients.

Plasma samples from 13 HNC patients (mean age 62 years) and two healthy controls (mean age 22 years) were analyzed. Exosomes were isolated using the Plasma/Serum Circulating and Exosomal RNA Purification Kit (Slurry format) (Norgen Biotek). Extracted RNA was reverse transcribed using the Maxima First Strand cDNA Synthesis Kit. ERP29 expression was quantified by qPCR with TaqMan probes, using GAPDH as the endogenous control and the 2Ct method. Results were expressed in arbitrary units (AU).

ERP29 transcripts were detected in circulating exosomes from all individuals, including controls. Nine of the 13 patients showed increased expression compared to controls, with values ranging from 1.60 to 33.18 AU. Four patients presented expression levels similar to controls (0.81, 1.08, 1.11, and 1.28 AU).

The results demonstrate the feasibility of detecting ERP29 transcripts in circulating exosomes. The observed variability among patients suggests that ERP29 expression may be associated with distinct clinical and tumor characteristics.

This pilot study supports the use of exosomal RNA to evaluate ERP29 expression in HNC and encourages further investigation in larger cohorts to assess potential clinical and prognostic relevance.