3316

HSPB2

heat shock 27kDa protein 2;HSPB2;heat shock 27kDa protein 2

DMPK-binding protein|heat shock protein beta-2|heat-shock protein beta-2

11q22-q23

protein-coding

OBJECTIVE: To investigate the expression of 14-3-3 sigma and heat shock protein 27 (HSP27) in colorectal carcinoma(CRC) tissue and its clinical significance. METHODS: The expression of 14-3-3 sigma and HSP27 was detected by immunohistochemical staining in 50 pathologically verified CRC cases. The association of clinical data with 14-3-3 sigma and HSP27 expression was examined. RESULTS: The positive expression rate of 14-3-3 sigma was 10% in normal control mucosa and 58% in CRC tissue (P<0.01). The positive expression rate of HSP27 was 16% in normal control mucosa and 54% in CRC tissue (P<0.01). No correlation between 14-3-3 sigma and HSP27 expression was found in CRC tissue (P>0.05). The expression of 14-3-3 sigma was associated with patient age, tumor diameter and lymph node metastasis (LNM) (P<0.05), but not with gender, tumor differentiation or serous membrane invasion (P>0.05). The expression of HSP27 was associated with LNM (P<0.05), but not with gender, age, differentiation, tumor diameter or serous membrane invasion (P>0.05). CONCLUSION: The abnormal expression of 14-3-3 sigma and HSP27 is significantly associated with LNM in CRC.

BACKGROUND: During the process of metastasis, cells are subjected to various apoptotic stimuli. Aberrant expression of apoptotic regulators often contribute to cell metastasis. Heat shock protein 27(HSP27) is confirmed as an apoptosis regulator, but its antiapoptotic mechanism in metastatic hepatocellular carcinoma (HCC) cells remains unclear. METHODS: Levels of HSP27 protein and its phosphorylation in Hep3B, MHCC97L to MHCC97H cells with different metastatic potentials were determined by western blot analysis. MHCC97H cells were transfected with specific small interference RNA (siRNA) against HSP27. The in vitro migration and invasion potentials of cells were evaluated by Transwell assay. The apoptosis ratio of MHCC97H cells was analyzed by TUNEL staining and Flow Cytometry. Alteration of signal transduction pathway after HSP27 knockdown in MHCC97H cells was evaluated through a Human Q Series Signal Transduction in cancer Gene Array analysis. Nuclear NF-kappaB contentration and endogenous IKK activity were demonstrated by ELISA assay. The association of IKKalpha, IKKbeta, IkappaBalpha with HSP27 and the association between IKKbeta and IKKalpha in MHCC97H cells were determined by co-immunoprecipitation assay followed by western blot analysis. RESULTS: HSP27 protein and its phosphorylation increased in parallel with enhanced metastatic potentials of HCC cells. siRNA-mediated HSP27 knockdown in MHCC97H significantly suppressed cells migration and invasion in vitro and induced cell apoptosis; the prominently altered signal transduction pathway was NF-kappaB pathway after HSP27 knockdown in MHCC97H cells. Furthermore, inhibition of HSP27 expression led to a significant decrease of nuclear NF-kappaB contentration and endogenous IKK activity. In addition, HSP27 was associated with IKKalpha, IKKbeta, IkappaBalpha in three HCC cells above. ELISA assay and western blot analysis also showed a decrease of the association between IKKbeta and IKKalpha, the association between phosphor-HSP27 and IKK complex, and an increase of total IkappaBalpha but reducing tendency of phosphor-IkappaBalpha when HSP27 expression was efficiently knocked down in MHCC97H cells. CONCLUSION: Altogether, these findings revealed a possible effect of HSP27 on apoptosis in metastatic HCC cells, in which HSP27 may regulate NF-kB pathway activation.