Gemcitabine combined with gum mastic causes potent growth inhibition and apoptosis of pancreatic cancer cells.

Aim: To investigate the antiproliferative and apoptotic effects of gemcitabine combined with gum mastic and the underlying mechanisms in human pancreatic cancer cell lines.

Methods: Cell proliferation and apoptosis were examined using the methyl thiazolyl tetrazolium (MTT) assay and propidium iodine staining, respectively. The expression of Bcl-2, Bax, NF-kappaB p65 subunit, and IkappaBalpha protein was measured using Western blotting.

Downregulation of IgG Fc binding protein (Fc gammaBP) in prostate cancer.

By means of protein expression profile, mass spectral and/or RT-PCR analyses we found for the first time IgG Fc binding protein (Fc gammaBP), distinct from Fc gamma receptors is expressed in both human and mouse prostates. There is a strong correlation between downregulation of Fc gammaBP and the progression of prostate cancer in Transgenic Adenocarcinoma Mouse Prostate (TRAMP) mice. Fc gammaBP gene expression is significantly reduced or lost in human prostate tumor tissues and prostate cell lines.

Gum mastic increases maspin expression in prostate cancer cells.

Aim: To study whether gum mastic, a natural resin, can regulate maspin expression in prostate cancer cells, and further investigate the mechanisms involved in this regulatory system.

Methods: RT-PCR and Western blotting were used to detect maspin expression at the transcriptional and translational levels. Reporter gene assay was used to investigate the effect of gum mastic on the maspin promoter.

Mechanisms of antiprostate cancer by gum mastic: NF-kappaB signal as target.

Aim: To study the effect of gum mastic, a natural resin, on the proliferation of androgen-independent prostate cancer PC-3 cells, and further investigate the mechanisms involved in this regulatory system, taking nuclear factor kappaB (NF-kappaB) signal as the target.

Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a flow cytometer were used to detect the effect of gum mastic on the proliferation of PC-3 cells. Then, reporter gene assay, RT-PCR, and Western blotting were carried out to study the effects of gum mastic on the NF-kappaB protein level and the NF-kappaB signal pathway.

[The roles of c-Jun and CBP in the inhibitory effect of quercetin on prostate cancer cells].

Aim: To further uncover the possible mechanism of quercetin-mediated inhibitory effect on prostate cancer cells.

Methods: The cell extracts treated with quercetin or without treatment were used for checking protein expression levels of c-Jun and cAMP response element binding protein (CREB)-binding protein (CBP) by Western blotting assay. Regulatory effects of c-Jun and CBP on the function of androgen receptor (AR) were examined by cotransfection experiment.

Gum mastic inhibits the expression and function of the androgen receptor in prostate cancer cells.

Accumulating evidence suggests that the androgen receptor (AR) may play an important role in the development and progression of prostate cancer. To find new, useful compounds that effectively may attenuate the function of AR in prostate cancer cells, the authors investigated the effect of gum mastic, a natural resin, on AR activity. An androgen-responsive prostate cancer cell line LNCaP was used as a model for this study.

Identification of androgen-responsive element ARE and Sp1 element in the maspin promoter.

Maspin is a serine protease inhibitor (serpin) with tumor-suppressing function in mammary gland. It is down-regulated in primary prostate cancer cells and lost in metastatic cells. To better understand the transcriptional regulation of maspin gene, the 860bp (-765 approximately +95) of its promoter sequence was amplified by PCR from the human genomic DNA.

Up-regulation of NKX3.1 expression and inhibition of LNCaP cell proliferation induced by an inhibitory element decoy.

NKX3.1 is an androgen-regulated prostate-specific homeobox gene that is thought to play an important role in prostate development and cancerogenesis. NKX3.