[Retracted] Functional characterization of the nitrogen permease regulator­like­2 candidate tumor suppressor gene in colorectal cancer cell lines.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that certain of the microscopic images shown in Fig. 1C on p. 3489 and the invasion assay images shown in Fig. 5 on p. 3491 were strikingly similar to data appearing in different form in other articles written by different authors at different research institutes. Moreover, unexpected similarities were identified comparing between a pair of the flow cytometric assay data panels in Fig. 4 on p. 3490, considering that these data were intended to show the results from differently performed experiments. Owing to the fact that the contentious data in the above article had already been published, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 12: 3487­3493, 2015; DOI: 10.3892/mmr.2015.3881].

Individualized endoscopic management strategy for impacting jujube pits in the upper gastrointestinal tract: a 3-year single-center experience in northern China.

BACKGROUND: Impaction of jujube pits in the upper gastrointestinal (GI) tract is a special clinical condition in the northern Chinese population. Endoscopic removal is the preferred therapy, but there is no consensus on the management strategies. We reported our individualized endoscopic strategies on the jujube pits impacted in the upper GI tract. METHODS: In this retrospective study, we included 191 patients (male: 57; female: 134) who presented to our hospital with ingestion of jujube pits between January 2015 and December 2017. Demographic information, times of hospital visiting, locations of jujube pits, endoscopic procedures, post-extraction endoscopic characteristics were analyzed. Management strategies including sufficient suction, repeated irrigation, jejunal nutrition and gastrointestinal decompression were given based on post-extraction endoscopic characteristics and impacted locations. RESULTS: Peak incidence was in the second quarter of each year (85/191 cases, 44.5%). Among the 191 cases, 169 (88.5%) showed pits impaction in the esophagus, 20 (10.5%) in the prepyloric region and 2 (1.0%) in the duodenal bulb. A total of 185 patients (96.9%) had pits removed with alligator jaw forceps, and 6 (3.1%) underwent suction removal with transparent caps placed over the end of the endoscope to prevent injury on removal of these pits with two sharp painted edges. Post-extraction endoscopic manifestations included mucosal erosion (26.7%), mucosa laceration (24.6%), ulceration with a white coating (18.9%) and penetrating trauma with pus cavity formation (29.8%). All patients received individualized endoscopic and subsequent management strategies and showed good outcomes. CONCLUSIONS: Individualized endoscopic management for impacted jujube pits in the upper GI tract based on post-extraction endoscopic characteristics and impacted locations was safe, effective, and minimally invasive.

TGF-ß1 pathway affects the protein expression of many signaling pathways, markers of liver cancer stem cells, cytokeratins, and TERT in liver cancer HepG2 cells.

Liver cancer is one of the most common human malignancies, and transforming growth factor-beta (TGF-ß) pathway plays a key role in its pathogenesis. To study the relationship between TGF-ß pathway and the related protein expression of many signaling pathway, markers of stem cells, CK family, and others, liver cancer HepG2 cells were transfected with siRNA directed against TGF-ß1 or were treated with exogenous TGF-ß1. Then, these protein levels were measured by Western blotting. After siRNA transfection, TGF-ß1 protein level was decreased, indicating that the siRNA against it was effective. In exogenous TGF-ß1 group, the expression of smad4, smad2/3, and ß-catenin proteins was increased, whereas that of p-smad2/3, CD133, cleaved Notch1, and epithelial cell adhesion molecule (EpCAM) proteins at 48 h was decreased. The expression of CK8 and CK18 proteins was increased at 24 h and was decreased at 48 and 96 h. In TGF-ß1-silenced group, the expression of smad2/3, ß-catenin, cleaved-notch1, and CK18 proteins was decreased, while that of smad4, p-smad2/3, CD133, EpCAM, and CK8 proteins was increased. TERT protein expression was slightly increased in exogenous TGF-ß1 group at 48 h and in TGF-ß1-silenced group at 96 h. TGF-ß1 did not affect the protein expression of CK19 and HIF-1. Thus, TGF-ß1 pathway plays an important role in cell regulation of liver cancer through the modulation of these proteins. These data will contribute to the understanding of the pathogenesis of liver cancer and the role of TGF-ß pathway in this process.

Functional characterization of the nitrogen permease regulator-like-2 candidate tumor suppressor gene in colorectal cancer cell lines.

The nitrogen permease regulator­like­2 (NPRL2) gene is a candidate tumor suppressor gene, which has been identified in the 3p21.3 human chromosome region. Decreased expression levels of NPRL2 have been observed in colorectal cancer (CRC) tissues, however, the function of NPRL2 in CRC progression remains to be fully elucidated. The present study investigated the biological characteristics of the HCT116 and HT29 CRC cell lines overexpressing exogenous NPRL2. NPRL2 recombinant lentiviral vectors were also constructed and transfected in the present study. Cell growth was determined using a Cell Counting Kit­8 assay and a colony formation assay. The cell cycle and rate of apoptosis were assessed using flow cytometric analysis. Transwell assays were used to evaluate cell invasion. The protein expression of phosphorylated (p)­AKT and caspase 3, B­cell lymphoma 2 (Bcl2) and Bcl­2­associated X protein apoptosis­associated genes, were detected using western blotting. The results revealed that NPRL2 overexpression inhibited cell growth, induced cell cycle G1 phase arrest, promoted apoptosis and inhibited invasion in the two human CRC cell lines. Furthermore, the protein expression levels of p­AKT and Bcl2 were significantly reduced in the NPRL2­transfected HCT116 and HT29 cells, compared with the mock­transfected group and control group, while the protein expression of caspase­3 was increased. Therefore, NPRL2 acted as a functional tumor suppressor in the CRC cell lines.

Simultaneous silencing of ß-catenin and signal transducer and activator of transcription 3 synergistically induces apoptosis and inhibits cell proliferation in HepG2 liver cancer cells.

The tumorigenesis and maintenance of a cancer cells is dependent upon the collaboration of multiple signaling pathways. Signal transducer and activator of transcription 3 (STAT3) and ß-catenin are at the center of multiple cancer-associated signaling pathways; therefore, simultaneously targeting STAT3 and ß-catenin may be a potential cancer treatment, leading to induced lethality of cancer cells. In the present study, HepG2 liver cancer cells were transfected with small interfering RNA (siRNA) against ß-catenin and STAT3 alone or in combination. The cell growth was assessed using an MTT assay and the levels of cell apoptosis were detected using flow cytometry. Protein levels of caspase-3, cleaved caspase-3, poly(ADP-ribose) polymerase (PARP) and cleaved PARP were determined using western blot analysis. Following siRNA transfection, ß-catenin and STAT3 protein levels decreased at 72 h. HepG2 cell growth inhibition and early apoptosis in the ß-catenin and STAT3 siRNA co-transfection group were significantly greater than those in the groups transfected with ß-catenin or STAT3 siRNA alone. Decreased caspase-3 and PARP levels, as well as enhanced cleavage of caspase-3 and PARP were observed in the ß-catenin and STAT3 co-transfection group. Simultaneous silencing of ß-catenin and STAT3 using siRNAs resulted in an enhanced loss of cell viability and induction of apoptosis in HepG2 liver cancer cells, suggesting that these genes are promising targets for the further preclinical and clinical development of anti-cancer therapeutic strategies, which target several cancer signaling pathways simultaneously.

Nitrogen permease regulator-like 2 enhances sensitivity to oxaliplatin in colon cancer cells.

Colorectal cancer (CRC) is the third most common cancer worldwide. Chemotherapeutic compounds used for the treatment of CRC include oxaliplatin (L-OHP). While L-OHP improves CRC survival, certain patients are resistant. The nitrogen permease regulator like-2 (NPRL2) gene is a candidate tumor suppressor gene that resides in a 120-kb homozygous deletion region on chromosome 3p21.3. In the present study, it was demonstrated that NPRL2 overexpression increases the sensitivity of HCT116 cells to L-OHP. The IC50 of L-OHP was decreased in cells transduced with NPRL2 compared with negative control (NC) cells and the effect of NPRL2 on L-OHP sensitivity was time dependent. Following NPRL2 transduction in HCT116 cells, the cell cycle was arrested in the G1 phase and a partial decrease in the S phase population was observed. Flow cytometric analysis revealed that NPRL2 transduction and L-OHP treatment increased apoptosis compared with NC cells. The mechanism through which NPRL2 overexpression enhances L-OHP sensitivity involves downregulation of the functions of the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin network. Furthermore, L-OHP upregulated caspase-3 and caspase-9 to promote apoptosis in NPRL2-overexpressing cells compared with cells that were transduced with NPRL2 or treated with L-OHP and NC cells (P<0.01). NPRL2 overexpression led to the downregulation of CD24, which could significantly reduce tumor invasiveness and decrease the metastatic capacity of HCT116 cells. These mechanisms are likely active in other types of cancer and may be exploited for the development of novel cancer therapies.

Protection of cultured human hepatocytes from hydrogen peroxide­induced apoptosis by relaxin­3.

Previous studies have suggested that hepatocyte apoptosis may be a fundamental underlying mechanism of liver injury and diseases, such as liver fibrosis. Relaxin­3 has been reported to have anti­fibrotic actions in the heart and to attenuate isoproterenol­induced myocardial injury; however, the beneficial role of relaxin­3 on hepatocyte apoptosis remains to be elucidated. The aim of the present study was to explore the role and possible mechanisms of relaxin­3 through hydrogen peroxide (H2O2)­induced apoptosis in primary human hepatocytes. Cells were treated with relaxin­3 and then cell viability, morphological features, the presence of cleaved caspases as well as the levels of endoplasmic reticulum stress (ERS) protein markers and autophagy markers were evaluated. The H2O2 group showed significantly decreased cell viability, increased apoptosis as well as upregulation of caspases (cleaved caspase­3, ­8 and ­9) and ERS protein markers compared with those of the control group. However, cells treated with relaxin­3 (10 ng/ml) demonstrated improved cell viability, reduced apoptosis and decreased expression of cleaved caspases and ERS markers. However, the expression of autophagy markers remained unchanged following H2O2­induced apoptosis and relaxin­3 treatment. In conclusion, relaxin­3 was shown to protect hepatocytes from H2O2­induced apoptosis via downregulation of cleaved caspase­8 and ­9, as well as inhibition of the ERS pathway.

Functional mechanism of the enhancement of 5-fluorouracil sensitivity by TUSC4 in colon cancer cells.

5-Fluorouracil (5-FU) is the chemotherapeutic drug of choice for the treatment of metastatic colorectal cancer (CRC). Tumor suppressor candidate 4 (TUSC4), also referred to as nitrogen permease regulator-like 2 (NPRL2), is located at chromosome 3p21.3 and expressed in numerous normal tissues, including the heart, liver, skeletal muscle, kidney, and pancreas. The aim of the present study was to investigate the functional mechanism by which TUSC4 affects sensitivity to 5-FU and to determine its clinical significance in CRC. The results of the present study demonstrated that TUSC4 overexpression increases the sensitivity of HCT116 cells to 5-FU. The IC50 of 5-FU was reduced in cells transduced with TUSC4 compared with negative control (NC) cells, and the effect of TUSC4 on 5-FU sensitivity was time dependent. Following TUSC4 transduction in HCT116 cells, a proportion of the cells were arrested in the G1 phase of the cell cycle, and a reduction in the S phase population was observed. Flow cytometry analysis revealed that TUSC4 transduction and 5-FU treatment increased apoptosis compared with NC cells. The mechanism through which TUSC4 overexpression enhances 5-FU sensitivity involves the downregulation of the function of the PI3K/Akt/mTOR network. Furthermore, 5-FU upregulated caspase-3 and caspase-9, promoting apoptosis in TUSC4-overexpressing cells compared with cells that were transduced with TUSC4 or treated with 5-FU and NC cells. The findings of the present study indicate that TUSC4 has potential as a biomarker for the prediction of the response to 5-FU and prognosis in patients with colorectal cancer and other types of human cancer. TUSC4 may also act as a molecular therapeutic agent for enhancing the patient's response to 5-FU treatment.

[Relationship between corneal neovascularization and various relevant biological factors in surrounding cornea stroma of rats].

OBJECTIVE: To study the relationship between corneal neovascularization and various biological factors in corneal stroma of rats. METHODS: It was an experimental study. Corneal neovascularization was induced by alkali burn in 40 rats. Transforming growth factor-beta1 (TGF-beta1), alpha-smooth muscle actin (alpha-SMA) and fibroblast activation protein (FAP) in the stroma surrounding corneal neovascularization were detected by immunohistochemical studies on day 1, 3 and 7 after chemical burn. Platelet-endothelial cell adhesion molecule-1 (CD31) was used to identify the vascular endothelial cells. RT-PCR was used to identify FAP in the cornea 3 and 7 days after chemical burn. Picrosirius staining and polarization microscopy were used to detect changes of collagen types I and III in the cornea. RESULTS: After alkali burn, TGF-beta1 was first expressed in the cornea stroma. Then, some stroma cells expressed both alpha-SMA and FAP. The FAP(+) keratocytes were found surrounding the CD31(+) endothelium of angiogenesis. RT-PCR study showed that FAP mRNA was only present in neovascularized cornea and not in normal cornea. Polarization microscopy revealed that the collagen types I and III were rearranged in neovascularized cornea. CONCLUSIONS: Various biological factors in corneal stroma are changed when the cornea shows neovascularization. FAP(+) keratocytes are present in the stroma, and the appearance of these cells parallels the growth of vascular endothelial cells. Collagen types I and III are rearranged during the process of angiogenesis.

[The value of aetiology in the diagnosis of infectious keratitis].

Microbial keratitis is one of the major causes of blindness in China. The rapid and unequivocal identification of the causative organism is the key point for the rational antimicrobial therapy and restoration of the vision. It is difficult for the physician to choice the first step in the management of microbial keratitis: starting antimicrobial therapy after the identification of the causative organism, or starting therapy even there is no organism identification. The authors thought that it is urgent to start the antimicrobial therapy for microbial keratitis, however, the causative organism identification should be performed in time. This steps are necessary for the high diagnostic rate and cure rate of microbial keratitis, also for improving physician's consciousness of causative organism diagnosis.

Structural and functional analysis of natrin, a venom protein that targets various ion channels.

Cysteine-rich secretory proteins (CRISPs) are secreted single-chain proteins found in different sources. Natrin is a member of the CRISP family purified from the snake venom of Naja naja atra, which has been reported as a BKca channel blocker. In our study, crystals of natrin were obtained in two different crystal forms and the structure of one of them was solved at a resolution of 1.68A. Our electrophysiological experiments indicated that natrin can block the ion channel currents of the voltage-gated potassium channel Kv1.3. Docking analyses of the interaction between natrin and Kv1.3 revealed a novel interaction pattern different from the two previously reported K(+) channel inhibition models termed "functional dyad" and "basic ring". These findings offered new insights into the function of natrin and how the specific interactions between CRISPs and different ion channels can be achieved.