PRDX1, PRDX6 levels may be related to BRAF V600 mutation, tumor progression in PTCs

The dichotomous peroxiredoxin proteins PRDX1 and PRDX6 appear to be significantly inhibited in papillary thyroid carcinomas, a hypoexpression that may be related to the BRAF V600E gene mutation, according to study results.

Researchers evaluated the expression of PRDX1 and PRDX6 in a group of 32 thyroid tissue samples encompassing different thyroid diseases; of the samples, 13 were papillary thyroid carcinomas (PTCs).  The researchers analyzed the expression of PRDX1 and PRDX6 in the tissues via quantitative reverse transcriptase polymerase chain reaction (qRT-PCR).

Although all tissues showed levels of PRDX1 and PRDX6, PRDX1 expression in the PTC group showed a statistically significant 14-fold reduction compared with normal tissue and 26-fold reduction compared with follicular adenoma tissues (P<.05). The significant decrease also was apparent when comparing PTC with other samples, such as non-neoplastic multinodular goiter (16-fold decrease) and to follicular carcinomas (18-fold decrease).

Similarly, PRDX6 expression showed a statistically significant decrease compared with normal tissue, multinodular goiter and follicular neoplasms (P<.05).

Additionally, the researchers found that the reduced expression of PRDX1 and PRDX6 was particularly pronounced in BRAF V600E-mutated samples compared with non-mutated samples (roughly four- and threefold, respectively). The results also showed a correlation — regardless of BRAF status — between the lowest PRDX1 and PRDX6 levels and tumor size and nodal metastases.

These findings suggest that PRDX1 and PRDX6 are potential targets of BRAF V600E and indicators of tumor growth, the researchers concluded.

“These data indicate that PRDX1 and PRDX6 expression not only may play a key role in papillary thyroid  carcinogenesis via a BRAF V600E-dependent mechanism, but their determination could be considered as potential tumor marker for indicating tumor progression in PTCs, independently of BRAF status,” the researchers wrote.

Disclosure: The study was supported in part by grants from ASI-Italian Space Agency.