Role of laminin 332 in lymph node metastasis of papillary thyroid carcinoma.

OBJECTIVE: The invasiveness of papillary thyroid carcinoma (PTC), including the occurrence of cervical lymph node metastasis, is the main determining factors contributing to recurrence and poor prognosis. Laminin 332 is a glycoprotein involved in cell migration and cancer cell invasion into surrounding tissues and is therefore related to poor prognosis in many cancers. Here, we investigated the expression and role of laminin 332 in PTC and examine the possibility that laminin 332 could be involved in the invasiveness of PTC.

METHODS: Laminin 332 expression was determined by immunohistochemical staining in all 40 patients. The correlations between laminin 332 expression and clinical factors were investigated. We examined the expression of the laminin 332 γ2 chain using reverse transcription polymerase chain reaction and western blotting in PTC cells and determined the relationship between the expression of laminin 332 and the invasiveness of these cell lines using cell invasion assays.

RESULTS: Laminin 332 was expressed specifically within tumor tissue. The frequency of laminin 332 γ2 chain expression was significantly correlated with cervical lymph node metastasis (​p=0.003). Invasiveness increased as the expression of laminin 332 γ2 increased in the tested PTC cell lines.

CONCLUSION: Laminin 332 expression may be a useful marker for predicting lymph node metastasis in papillary thyroid carcinoma, and could increase the ability of cancer cells to invade, which would influence the prognosis of patients with PTC.