HSP70 and mucin 5B: novel protein targets of N,N'-dinitrosopiperazine-induced nasopharyngeal tumorigenesis.

N,N'-Dinitrosopiperazine (DNP) induces nasopharyngeal carcinoma (NPC) and shows organ specificity to the nasopharyngeal epithelium. To investigate its mechanism, the rat NPC model was induced using DNP. Rat NPC and normal nasopharyngeal cells were obtained from the NPC model using laser capture. The total proteins from these cell samples were separated with two-dimension polyacrylamide gel electrophoresis techniques, and highly expressed proteins (> five-fold) were analyzed using matrix-assisted laser desorption/ionization time of flight and bioinformatics. The results showed that HSP70 and mucin 5B expression increased not only in rat NPC but also in atypical hyperplasia nasopharyngeal tissues, a precancer stage of NPC. High-expression of heat shock protein 70 (HSP70) and mucin 5B was further supported by western blot analysis. The immunofluorescence and western-blotting studies further showed that DNP induced the expression of HSP70 and mucin 5B in a dosage-dependent manner in normal nasopharyngeal epithelia cells. Our data indicate that DNP triggers over-expression of HSP70 and mucin 5B, and is involved in nasopharyngeal tumorigenesis. HSP70 and mucin 5B may be important targets in nasopharyngeal tumorigenesis induced by DNP.

[Association of CK20 expression with the progression, metastasis and prognosis of breast cancer].

AIM: To analyze the expression of CK20 in human breast cancer, and to evaluate the association between its expression and tumor's progression and prognosis. METHODS: 86 cases with breast cancer, 20 cases of benign tumor tissues were examined for the expression of CK20 by immunohistochemical staining. RESULTS: The positive rate of CK20 expression in breast cancer was 80.23% (69/86), which was significantly higher than that in benign tumor tissues of breast [20.00% (4/20), P<0.01]. CK20 expression was associated with the histologic grades (P<0.05) and the pathological types (P<0.01). The expression of CK20 was observed to correlate positively with TNM stages (r=0.86, P<0.05), lymph node status (r=0.73, P<0.05) and HER-2 status (r=0.69, P<0.05), and correlate negatively with ER status (r=-0.58, P<0.05). Moreover, Kaplan Meier curves of overall survival analysis showed a significant difference between CK20 positive groups and negative group (P<0.01). CONCLUSION: The results suggest that the expression of CK20 may be associated with the progression and prognosis of breast cancer.