A Novel Plant Homeodomain Finger 10–Mediated Antiapoptotic Mechanism Involving Repression of Caspase-3 in Gastric Cancer Cells

Abstract

The mechanisms governing tumorigenesis of gastric cancer have been an area of intense investigation. Currently, plant homeodomain (PHD) finger (PHF) proteins have been implicated in both tumor suppression and progression. However, the function of PHF10 has not been well characterized. Here, we show that various levels of PHF10 protein were observed in gastric cancer cell lines. Alteration of PHF10 expression, which is associated with tumor cell growth, may result in apoptosis in gastric cancer cells both in vitro and in vivo. Knockdown of PHF10 expression in gastric cancer cells led to significant induction of caspase-3 expression at both the RNA and protein levels and thus induced alteration of caspase-3 substrates in a time-dependent manner. Moreover, results from luciferase assays indicated that PHF10 acted as a transcriptional repressor when the two PHD domains contained in PHF10 were intact. Combined with previous findings, our data suggest that PHF10 transcriptionally regulates the expression of caspase-3. Finally, by using systematic reporter deletion and chromatin immunoprecipitation assays, we localized a region between nucleotides −270 and −170 in the caspase-3 promoter that was required for the efficient inhibition of caspase-3 promoter activity by PHF10. Collectively, our findings show that PHF10 repressed caspase-3 expression and impaired the programmed cell death pathway in human gastric cancer at the transcriptional level.

PKB-mediated PHF20 phosphorylation on Ser291 is required for p53 function in DNA damage

“…Similar to PHF20, other members of PHD finger family are well documented as transcriptional regulators [7]. Notably, PHD finger family proteins (e.g., PHF1, PHF6, PHF3, PHF10 and PHF11) have been implicated in cancer and autoimmune diseases due to their transcriptional and immunogenic function on targeted proteins [7][8][9][10]11 ].…”

Integrity of the LXXLL motif in Stat6 is required for the inhibition of breast cancer cell growth and enhancement of differentiation in the context of progesterone

“…Cellular DNA content and flow cytometry profiles were determined, respectively, by the staining of nuclear DNA using the fluorochrome 3,5-diaminobenzoic acid (free acid) and propidium iodide as described previously [27]. Transient transfections were performed with Lipo2000 (Invitrogen, Carlsbad, USA) as previously described [28]. Chromatin immunoprecipitation assays were performed as described elsewhere [28] using 40 μg of anti-Stat6 (Abcam), anti-Progesterone Receptor, (anti-PR, specific for the β-form of PR) (Abcam), and anti-p300 (Santa Cruz) and anti-Sp1 (Santa Cruz) antibodies for the immunoprecipitation of cell lysates.…”

“…Transient transfections were performed with Lipo2000 (Invitrogen, Carlsbad, USA) as previously described [28]. Chromatin immunoprecipitation assays were performed as described elsewhere [28] using 40 μg of anti-Stat6 (Abcam), anti-Progesterone Receptor, (anti-PR, specific for the β-form of PR) (Abcam), and anti-p300 (Santa Cruz) and anti-Sp1 (Santa Cruz) antibodies for the immunoprecipitation of cell lysates. Briefly, T47D cells were subjected to chromatin immunoprecipitation (ChIP) with the ChIP Assay kit (Upstate Cell Signaling Solutions).…”

PHF21B overexpression promotes cancer stem cell-like traits in prostate cancer cells by activating the Wnt/β-catenin signaling pathway

“…Previous study has shown that proteins of the PHD zinc finger superfamily are capable of translocating to the nucleus and regulating transcription of genes, and involve in tumor progression in various types of cancers, including PCa [26–29]. High levels of PHF8 were associated with high Gleason grade and poor prognosis in PCa, and strengthened PCa cell migration and invasion in vitro [28].…”