The results suggested that PIG3 plays an oncogenic role in PTC via the regulation of the PI3K/AKT/PTEN pathway and support the exploration of PIG3 as a novel biomarker for patients with PTC.
CS/CS-like patients have elevated risks of follicular thyroid cancer due to PTEN pathogenic mutations and of papillary thyroid cancer from SDHx and KLLN alterations.
Tumors and matched normal thyroid samples were tested for RAS, for the v-raf murine sarcoma viral oncogene (BRAF) substitution of valine (V) for glutamate (E) at codon 600 (the V600E mutation), for phosphatase and tensin homolog (PTEN), for catalytic PI3k p110 subunit alpha (PIK3CA), for AKT, and for the presence of rearranged during transfection (ret) proto-oncogene/PTC (RET-PTC) and paired box-8 (PAX8)/peroxisome proliferator-activated receptor gamma (PPARgamma) fusion protein (PAX8-PPARgamma) rearrangements by direct sequencing and reverse transcriptase-polymerases chain reaction analyses, respectively.
H4-PTEN were detected in 9.6% of PTC and the frequency of the occurrence of BRAF mutation and/or RET/PTC in H4-PTEN positive tumors was extremely high (75%).
We found PIK3CA copy gain (defined as four or more copies) in nine of 31 FTC (29%), 20 of 141 PTC (14%), and five of 62 FTA (8%); PIK3CA gene mutations in four of 31 FTC (13%), one of 141 PTC (1%), and none of 62 FTA (0%); Ras mutations in three of 31 FTC (10%) and none of the 141 PTC and 62 FTA; and PTEN mutations in two of 31 FTC (6%) and none of 62 FTA (0%).
Transient expression of PTEN in seven thyroid cancer cell lines resulted in G(1) arrest in two well differentiated papillary thyroid cancer lines (PTCs) and both G(1) arrest and cell death in the remaining five lines, including three FTCs, one poorly differentiated PTC and one undifferentiated thyroid cancer.