Retraction note to: Lentivirus-Mediated Short-Hairpin RNA Targeting Protein Phosphatase 4 Regulatory Subunit 1 Inhibits Growth in Breast Cancer.

[This retracts the article on p. 218 in vol. 18, PMID: 26472971.].

Erratum: Lentivirus-Mediated Short-Hairpin RNA Targeting Protein Phosphatase 4 Regulatory Subunit 1 Inhibits Growth in Breast Cancer.

[This corrects the article on p. 218 in vol. 18, PMID: 26472971.].

Lentivirus-Mediated Short-Hairpin RNA Targeting Protein Phosphatase 4 Regulatory Subunit 1 Inhibits Growth in Breast Cancer.

PURPOSE: Protein phosphatase 4 regulatory subunit 1 (PP4R1), as an interaction partner of the catalytic serine/threonine-protein phosphatase 4 catalytic subunit has been shown to involve in cellular processes and nuclear factor κB signaling. However, the functions of PP4R1 in human breast cancers remain unclear. This study is designed to explore the effect of PP4R1 knockdown on the biological characteristics of breast cancer cells. METHODS: A lentivirus-mediated short hairpin RNA (shRNA) was designed to knockdown the expression of PP4R1 in ZR-75-30 breast cancer cells. The efficiency of lentivirus-mediated shRNA infection was determined using fluorescence microscopy to observe lentivirus-mediated green fluorescent protein expression and confirmed to be over 80%. PP4R1 expression in infected ZR-75-30 cells was detected by quantitative real-time polymerase chain reaction and western blot analysis. Cell proliferation and colony formation ability were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and colony formation assay, respectively. Flow cytometry was used to measure cell cycle progression and cell apoptosis. In addition, apoptosis makers, including poly-ADP-ribose polymerase (PARP) and caspase-3, were investigated in PP4R1-silenced ZR-75-30 cells by western blot assay. RESULTS: We successfully constructed lentivirus-mediated shRNA to target PP4R1 in ZR-75-30 cells. MTT assay and colony formation assay showed the loss of PP4R1 suppressed the proliferation of ZR-75-30 cells. Flow cytometry analysis indicated cell cycle arrest and increased cell apoptosis in PP4R1 knockdown cells. Further, the apoptosis response in cells depleted of PP4R1 was illustrated by downregulation of PARP and upregulation of caspase-3. CONCLUSION: Our results suggest that PP4R1 could promote breast cancer cell proliferation and might play a vital role in breast cancer occurrence.

[Relationship of angiotensin-converting enzyme 2 gene polymorphisms and vulnerability to coronary heart disease in patients with type 2 diabetes mellitus].

OBJECTIVE: To investigate the association of angiotensin-converting enzyme 2 (ACE2) gene polymorphisms and coronary artery disease (CAD) in patients with type 2 diabetes mellitus (T2DM). METHODS: This study involved 121 patients with T2DM and 94 with diabetic macroangiopathy. The polymorphisms of G8790A in ACE2 gene was analyzed using PCR-restriction fragment length polymorphism analysis in these patients, and the clinical, biochemical and echocardiographic data were also analyzed. RESULTS: No obvious difference was found in the genotyping data between the two groups. Among the male patients with diabetic macroangiopathy, the interventricular septal end-diastolic thickness (IVSTd) were significantly greater in patients of GG genotypes of ACE2 gene G8790A than in those of AA genotypes (P<0.01), and the left ventricular mass (LVMI) and urine protein were also significantly higher in GG genotypes (P<0.05). No similar results were found the uncomplicated diabetic group or the female diabetic patients with CAD. CONCLUSION: The ACE2 gene G8790A polymorphism plays a role in the pathogenesis of CAD in patients with type 2 diabetes, suggesting that ACE2 genotyping is helpful to screen the susceptible patients.

Effect of estrogen and progesterone on the expression of 1, 25-dihydroxyvitamin D receptors mRNA in the liver of ovariectomized rats.

OBJECTIVE: To study the effect of estrogen and progesterone on the expression of dihydroxyvitamin D receptor (VDR) mRNA in the liver of ovariectomized rats. METHODS: Twenty-five adult female SD rats were randomly divided, with equal numbers, into sham-operated group (sham), ovariectomized group (OVX), ovariectomized group with estrogen treatment (OVX+E), ovariectomized group with progesterone treatment (OVX+P) and ovariectomized group with both estrogen and progesterone treatment (OVX+E+P). After 3 months and a half of feeding, all animals were killed to assess VDR mRNA by way of reverse transcriptase-PCR (RT-PCR). RESULTS: RT-PCR revealed marked increase in the band intensity corresponding to VDR mRNA product in Sham, OVX+E, and OVX+E+P groups. CONCLUSION: Estrogen may increase the transcription level of VDR gene in the liver of ovariectomized rats.