Two human tongue squamous cell carcinoma cell lines, SQUU-A and SQUU-B, were established from the same patient. Cervical lymph node metastasis was detected in the mice orthotopically implanted with SQUU-B (86.7%, 13/15), but not in those with SQUU-A (0/13). Histologically, SQUU-B showed invasive growth and intravasation in the tongue, whereas SQUU-A simply demonstrated expansive growth without intravasation. By Western blot analysis, nonmetastatic clone SQUU-A expressed cytokeratin (CK)13/4, 14, 16/6, 18/8, and 19, whereas a high metastatic clone SQUU-B expressed CK18/8 and 19. The reverse transcription-polymerase chain reaction technique showed that CK13/4 mRNA was expressed in both cell lines, but CK14 and 16 mRNA was expressed only in SQUU-A. CK13 was immunohistochemically expressed in both SQUU-A and SQUU-B transplanted into the tongues of nude mice; CK14 and 16 were detected in SQUU-A of the tongues, but not in SQUU-B. As seen in SQUU-B cell line, SQUU-B of the cervical lymph node metastasis did not exhibit CK13, 14, or 16. These results suggest that the loss or down-regulation of CK13, 14, or 16 is related to the invasive and metastatic ability of cancer. The cytoskeletal system is thus considered to be closely related to the malignant phenotype.
All Science Journal Classification (ASJC) codes
- Pathology and Forensic Medicine