Down-regulating Effect of a Standardized Extract of Cultured Lentinula edodes mycelia on Cortactin in Prostate Cancer Cells Is Dependent on Malignant Potential.

BACKGROUND/AIM: The incidence and mortality rates of prostate cancer have been increasing worldwide. Although prostate cancer cells grow slowly in the local original site, once the cancer cells spread to distant organs they grow rapidly and show very aggressive features. Cortactin is a protein that regulates the actin cytoskeleton and plays crucial roles in cancer metastasis. Up-regulated cortactin is correlated with the metastatic capacity of prostate cancer cells. AHCC®, a standardized extract of cultured Lentinula edodes mycelia, has been previously reported to have cortactin-down-regulating effects on human pancreatic cancer cells. In the present study, the effects of AHCC® treatment on cortactin levels in prostate cancer cells was evaluated. MATERIALS AND METHODS: LNCaP.FGC, DU145, and PC-3 are human prostate cancer cell lines. LNCaP.FGC is well differentiated, androgen-dependent, and poorly metastatic. DU145 is less differentiated, androgen-independent, and moderate metastatic. PC-3 is less differentiated, androgen-independent, and highly metastatic. The effects of AHCC® treatment on cortactin levels in prostate cancer cells was evaluated by western blot. RESULTS: In vitro AHCC® treatment decreased cortactin levels in LNCaP.FGC and DU145 cells but did not change those in PC-3 cells. CONCLUSION: AHCC® treatment down-regulated cortactin expression in poor and moderate metastatic LNCaP.FGC and DU145 cells but showed no effect on cortactin expression in the highly metastatic PC-3 cells. Further studies are required to elucidate the mechanism of the resistance to AHCC® treatment in highly metastatic PC-3 cells.

Enzyme-treated Asparagus Extract Down-regulates Heat Shock Protein 27 of Pancreatic Cancer Cells.

BACKGROUND/AIM: From the standpoint of cancer therapy, it is valuable to enhance the anticancer effects of chemotherapy. Our previous reports revealed that up-regulation of heat-shock protein 27 (HSP27) has been linked to gemcitabine resistance of pancreatic cancer cells. Enzyme-treated asparagus extract (ETAS) is an extract that is produced from asparagus. The purpose of this study was to investigate the effect of ETAS on the expression of HSP27 and other HSPs in the gemcitabine-resistant pancreatic cancer cell line KLM1-R. MATERIALS AND METHODS: KLM1-R cells were treated with ETAS, and expression levels of HSPs, including HSP27, were investigated by western blotting. RESULTS: ETAS down-regulated HSP27 and pHSP27 (serine 78) in KLM1-R cells, but, HSP70 and GRP78 levels were not altered. CONCLUSION: This study suggests the potential therapeutic benefit of ETAS in enhancing anticancer effects by its combination with gemcitabine for patients with pancreatic cancer.