Preliminary study on the mechanism of POFUT1 in colorectal cancer.

To analyse the effect of POFUT1 (Protein O-Fucosyltransferase 1) on the proliferation, migration and apoptosis of colorectal cancer (CRC) cells and to explore its potential mechanism. The effects of POFUT1 silencing in vitro on the proliferation, migration, and apoptosis of CRC cells were investigated using the SW480 and RKO cell lines. The effect of POFUT1 expression on cell phenotype was detected by cell proliferation assay (CCK8), colony formation assay, flow cytometry, wound healing assay, transwell assay, cell apoptosis assay, etc. In vitro, silencing of POFUT1 resulted in decreased proliferation, cell cycle arrest, reduced migration and increased apoptosis of CRC cells. In CRC cells, POFUT1 plays a tumour-promoting role by promoting cell proliferation and migration and inhibiting apoptosis.

MiR-301a Promotes Cell Proliferation by Repressing PTEN in Renal Cell Carcinoma.

OBJECTIVE: Renal cell carcinoma (RCC) displays an increasing incidence and mortality rate worldwide in recent years. More and more evidence demonstrated microRNAs function as positive or negative regulatory factors in many cancers, while the role of miR-301a in RCC is still unclear. MATERIAL AND METHODS: The expression and clinical significance of miR-301a were assessed via bioinformatic software on open microarray datasets of the Cancer Genome Atlas (TCGA) and then confirmed by quantitative real-time PCR (qRT-PCR) in RCC cell lines. Loss of function assays were performed in RCC cell lines both in vitro and in vivo. Cell Counting Kit-8 (CCK-8), flow cytometry, luciferase reporter assays, Western blotting, and immunohistochemistry were employed to explore the mechanisms of the effect of miR-301a on RCC. RESULTS: By analyzing RCC clinical specimens and cell lines, we found a uniform increased miR-301a in expression in comparison with normal renal tissue or normal human proximal tubule epithelial cell line (HK-2). In addition, miR-301a upregulation correlated advanced stage and poor prognosis of clear cell RCC (ccRCC). Anti-miR-301a could inhibit growth and cell cycle G1/S transition in RCC cell lines. Moreover, we found that PTEN was identified as a direct target of miR-301a that might partially interrupt miR-301a-induced G1/S transition. Importantly, nude-mouse models revealed that knockdown of miR-301a delayed tumor growth. CONCLUSION: These results indicate that miR-301a functions as a tumor-promoting miRNA through regulating PTEN expression, representing a novel therapeutic target for RCC.

Hyperglycaemia-induced miR-301a promotes cell proliferation by repressing p21 and Smad4 in prostate cancer.

Hyperglycaemia promotes the development of Prostate cancer (PCa). However, the roles of miRNAs in this disease process and the underlying mechanisms are largely unknown. In this study, we recruited 391 PCa patients in China and found that PCa patients with high level blood glucose (≥100 mg/dL) trended to have high Gleason score (GS ≥ 7). miRNA-301a levels were significantly higher in prostate cancer than that in normal prostate tissues. Hyperglycaemia or high glucose treatment induced miR-301a expression in prostate tissues or PCa cell lines. miR-301a suppressed the expression of p21 and Smad4, and subsequently promoted G1/S cell cycle transition and cell proliferation in vitro and xenograft growth in nude mice in vivo. Furthermore, knockdown of p21 and Smad4 mimicked the effects of miR-301a overexpression. Restoration of p21 and smad4 could interrupt the effects of miR-301a overexpression. Importantly, inhibition of miR-301a severely blocked high glucose-induced PCa cell growth both in vitro and in vivo. These results revealed a novel molecular link between hyperglycaemia and PCa. The miR-301a plays an important role in the hyperglycaemia-associated cancer growth, and represents a novel therapeutic target for PCa.

Identification of endonuclease domain-containing 1 as a novel tumor suppressor in prostate cancer.

BACKGROUND: Endonuclease domain containing 1 (ENDOD1) is implicated in tumorigenesis and aggressiveness of multiple tumors. In this study, we aimed to investigate the role of ENDOD1 in prostate cancer (PCa). METHODS: Immunohistochemistry were performed in 30 cases of benign prostatic hyperplasia (BPH) and 50 cases of PCa to identify its association with clinicopathological characteristics. Real-time PCR and western blot were used to detect ENDOD1 mRNA and protein expression in normal prostatic epithelial and PCa cell lines. MTT assays were employed to determine the effect of cell proliferation. Flow cytometry was used to explore the cell cycle distribution and apoptotic effects. Transwell migration and invasion assays were done to evaluate changes in the ability of cell migration and invasion. RESULTS: Immunoreactivity scores of ENDOD1 showed no statistical difference between BPH and low-grade PCa, whereas lower immunostaining scores were observed in high-grade compared with low-grade PCa. Real-time PCR data indicated that ENDOD1 mRNA expression was markedly increased in LNCaP and 22Rv1 cells and decreased in PC3 and DU145 cells compared to the normal epithelial cells RWPE1. Western blot showed that androgen-sensitive LNCaP cells had the highest protein expression level of ENDOD1, whereas castration-resistant PCa cell lines PC3 and DU145 had significantly lower protein levels. Meanwhile, overexpression of ENDOD1 suppressed cell proliferation, induced G0/G1 cell cycle arrest and inhibited cell migration and invasion. Conversely, siRNA-mediated silencing of ENDOD1 promoted cell proliferation, migration and invasion. No apoptotic effects occurred upon manipulation of ENDOD1 expression. CONCLUSION: Our results indicate that ENDOD1 is a novel tumor suppressor in PCa, which may be employed as a new drug target of preventing progression to metastatic castration-resistant prostate cancer.

Increased expression of glycolytic enzymes in prostate cancer tissues and association with Gleason scores.

OBJECTIVE: Recent studies have shown that understanding the differences between Gleason 3+4 and Gleason 4+3 in PCa patients may improve their treatment. This study aimed to evaluate the different expression levels of glycolytic proteins for Gleason score of 4+3 and 3+4. METHODS: A total of 90 PCa patients, including 38 cases with a Gleason score of 7, were included in this study. The expression of glycolytic proteins in both prostate cancer and normal prostate tissues, in GGG2 and GGG3 as well were assessed by immunohistochemical staining. RESULTS: Compared with GGG3, the GGG2 cases displayed significantly lower expression of all proteins (P < 0.05). The correlation among all enzymes showed that the key glycolytic enzyme, HK2, was significantly positively related to another key enzyme, PKM2 (r = 0.550, P < 0.01), and the expression of PFKFB4 was correlated with the expression of HK2 (r = 0.236, P < 0.05) and PKM2 (r = 0.392, P < 0.01). Additionally, neither GLUT1 nor PFKFB3 was correlated with PFKFB4, HK2 or PKM2. Further analysis showed that HK2 (r = 0.297, P < 0.01) and PKM2 (r = 0.431, P < 0.01) were significantly positively related to the Gleason score in PCa tissues. CONCLUSIONS: Glycolytic proteins expression levels were upregulated in PCa tissues. Furthermore, GGG3 exhibits a higher level of glycolysis compared with GGG2 in PCa tissues. Additionally, the key glycolytic enzymes, HK2 and PKM2, are overexpressed simultaneously in PCa and significantly correlate with PCa progression as represented by the GS.

Silencing of CDC20 suppresses metastatic castration-resistant prostate cancer growth and enhances chemosensitivity to docetaxel.

The role of cell division cycle 20 (CDC20) was investigated in chemoresistance to decetaxel and the underlying mechanisms in metastatic castration-resistant prostate cancer (mCRPC). MTT assays were performed to determine effects of siRNA-mediated CDC20 knockdown on cell proliferation and anticancer activity of docetaxel. Western blot analyses were conducted to detect changes of Akt and Wnt signaling. Furthermore, in vivo growth of PCa was examined in nude mice treated with siCDC20 or docetaxel alone or in combination. CDC20 was overexpressed in mCRPC cells. Knockdown of CDC20 suppressed cell proliferation and enhanced anticancer effect of docetaxel with IC50 reducing from 0.358 to 0.188 µg/ml in PC3 cells and 0.307 to 0.162 µg/ml in DU145 cells (P<0.01). While no change of Akt signaling was observed, inhibition of Wnt/ß-catenin signaling was detected upon CDC20 silencing. Xenograft tumor growth was significantly reduced in nude mice by CDC20 inhibition. The additional treatment of siCDC20 achieved better anticancer effects than that of docetaxel alone. Silencing of CDC20 may be a new strategy to improve chemosensitization to docetaxel in mCRPC.

Downregulation of microRNA-23a suppresses prostate cancer metastasis by targeting the PAK6-LIMK1 signaling pathway.

Here we found that levels of miR-23a were decreased in prostate cancer cell lines and tumor tissues. These low levels were associated with poor patients' prognosis. MiR-23a inhibited migration and invasion of prostate cancer in vivo and in orthotopic prostate cancer mice model. MiR-23a decreased levels of p21-activated kinase 6 (PAK6). Expression of miR-23a inhibited phosphorylation of LIM kinase 1 (LIMK1) and cofilin, in turn suppressing formation of stress fibers and actin filaments, which was required for cell motility and invasion. PAK6 bound to LIMK1 and activated it via phosphorylation at Thr-508. Also, PAK6 and LIMK1 were colocalized in the cytoplasma. Thus, miR-23a regulated cytoskeleton by affecting LIMK1 and cofilin. In summary, we have identified the miR-23a-PAK6-LIMK1 pathway of prostate cancer metastasis. Potential therapeutic approach by targeting miR-23 is suggested.

[Transcriptional regulation of breast cancer resistance protein].

Breast cancer resistance protein (BCRP), also known as ABCG2, is a member of the ATP-binding cassette (ABC) transporter superfamily, and is known to play important roles in cancer multidrug resistance. The BCRP promoter lacks a TATA-box and contains a CAAT-box, lots of AP1, AP2 sites and several putative Sp1 sites which are downstream of a putative CpG island. Several transcription factors, such as progesterone receptor (PR), estrogen receptor (ER), nuclear factor-κB (NF-κB), hypoxia-inducible factors (HIFs), nuclear factor erythroid 2-related factor 2 (Nrf2), aryl hydrocarbon receptor (AhR), peroxisome proliferator-activated receptors (PPARs) and Krüppel-like factor 5 (KLF5), have been recently shown to bind to their response elements in the promoter/enhancer to activate the transcription of BCRP. BCRP transcription can be influenced by proinflammatory cytokines, growth factors, and homeobox protein MSX2. Signaling pathways, such as Sonic hedgehog (Shh), Notch and RAR/RXR pathways, may also involve in the transcriptional regulation of BCRP. In addition, promoter methylation and histone acetylation are essential for the BCRP transcription, especially for the drug-induced BCRP expression. This paper reviews the recent research progresses in this field with an emphasis on the roles of transcription factors and epigenetics in the transcriptional regulation of BCRP.

[Association study between PPARGC1A Thr394Thr/ Gly482Ser polymorphisms and type 2 diabetes].

To investigate the association between single nucleotide polymorphisms (SNPs) rs2970847(Thr394Thr) and rs8192678(Gly482Ser) of peroxisome proliferators activated receptor gamma coactivator-1(PPARGC1A)gene and type 2 diabetes in Chinese Han population in Hubei. The Thr394Thr and Gly482Ser polymorphisms of the PPARGC1A gene were genotyped in 307 controls and 344 type 2 diabetes patients. Single marker/haplotype association analyses and logistic re-gression analysis were performed. Significant differences in genotypic and allelic frequencies were observed between cases and controls for the Thr394Thr polymorphism (genotype, P=0.006; allele, Plt;0.001). The genotype AA of the Thr394Thr polymorphism and the haplotype Thr394(ACA)- Ser482 were significantly associated with type 2 diabetes. No differences in the genotypic and allelic frequencies between cases and controls were found for the Gly482Ser polymorphism. PPARGC1A is a susceptibility gene for type 2 diabetes in Chinese Han population in Hubei.