[Expression analysis of NOTCH1/HES1/PTEN signaling pathway in invasive bladder transitional cell carcinoma].

OBJECTIVE: To explore the role of NOTCH1/HES1/PTEN signaling pathway in invasive TCCB (bladder transitional cell carcinoma).

METHODS: The expressions of NOTCH1, HES1 and PTEN were detected in 36 cases of invasive TCCB tissues and 10 cases of normal bladder samples by real-time q-polymerase chain reaction (q-PCR) and Western blot. Then NOTCH1-ORF plasmid and its blank vector pCMV6-Entry were transfected into T24 cell respectively. And the expressions of three above-mentioned target genes were measured by real-time q-PCR and Western blot. Furthermore, cell proliferation, cell apoptosis and cell cycle were analyzed respectively by MTS assay and flow cytometry.

RESULTS: Compared with normal bladder samples, the higher levels of both mRNA and protein of NOTCH1 and HES1 were detected in invasive TCCB tissues while there was a lower expression of PTEN (P < 0.05). The mRNA expression levels of NOTCH1 and HES1 were 4.22 and 3.75 folds respectively higher than those of normal tissues. In NOTCH1-overexpressed T24 cell, the expression of HES1 was 5.43 folds higher than that of the blank vector control group while the expression of PTEN declined to 41.76% (P < 0.01). MTS assay showed that the NOTCH1-ORF transfection obviously promoted cell proliferation in T24 cell (P < 0.01).

CONCLUSION: NOTCH1 gene may function as an oncogene by regulating HES1/PTEN in invasive TCCB and its aberrant activation promotes cell proliferation.