Although the expression level of claudin-1 based on immunohistochemistry was not associated with TSCC progression, within the high claudin-1 expression group, the incidence of the intracellular localization of claudin-1 was correlated with cervical lymph node metastasis.
Whereas, low expression of claudin-1 is not associated with gender (OR: 1.259, 95%CI: 0.957-1.657, P = 0.100), tumors' differentiation (OR: 1.317, 95%CI: 0.916-1.892, P = 0.137), depth of invasion (OR: 1.016, 95 %CI: 0.701-1.472, P = 0.935) and lymph node metastasis group (OR: 1.286, 95% CI: 0.982-1.684, P = 0.06) of CRC.
Negative PAR-3 protein expression, but not negative ZO-1 or claudin-1 expression, was significantly associated with deeper tumor invasion (P<.01), positive lymph node metastasis (P=.03), and advanced tumor stage (P=.01).
CLAUDIN-1 function was further investigated in two different follicular thyroid carcinoma cell lines: FTC-133 isolated from a regional lymph node metastasis and FTC-238 derived from a lung metastasis.
Claudin-1 expression was high in HSCC and was related to tumor differentiation and lymph node metastasis; Kaplan-Meier analysis showed that claudin-1 expression was related to patient survival rate (P = 0.012).
Stage N0 cancer tissues had higher levels of CLDN7 than did stages N1 and N2, suggesting that CLDN7 expression was closely related to the extent of lymph node metastasis.