MBNL1­AS1 attenuates tumor cell proliferation by regulating the miR­29c­3p/BVES signal in colorectal cancer.

Dysregulation of long non­coding RNAs (lncRNAs) is involved in the development of colorectal cancer (CRC). In the present study, the identification of muscle blind like splicing regulator 1 antisense RNA 1 (MBNL1­AS1) lncRNA was reported. Firstly, Cell Counting Kit­8, EdU and colony formation assays were uesed to explore the role of MBNL1­AS1 in regulating the proliferation of CRC cells. According to TCGA database, it was found that MBNL1­AS1 was correlated with microRNA (miR)­29c­3p and blood vessel epicardial substance (BVES) expression in CRC cells. Then, the regulation among MBNL1­AS1, miR­29C­3P and BVES was detected by dual luciferase reporter assay and the function of MBNL1­AS1/miR­29C­3P/BVES axis was explored by rescue assay. The results demonstrated that MBNL1­AS1 expression was decreased in CRC and was associated with the size of tumors derived from patients with CRC. Functionally, the upregulation of MBNL1­AS1 suppressed CRC cell proliferation in vitro and inhibited tumor growth in vivo, while knockdown of MBNL1­AS1 expression caused the opposite effects. MBNL1­AS1 expression correlated with BVES expression in CRC tissues and MBNL1­AS1 enhanced the stability of BVES mRNA by functioning as a competing endogenous RNA to sponge miR­29c­3p; the latter directly targeted MBNL1­AS1 and BVES mRNA 3'UTR. Collectively, the results indicated that MBNL1­AS1 suppressed CRC cell proliferation by regulating miR­29c­3p/BVES signaling, suggesting that the MBNL1­AS1/miR­29c­3p/BVES axis may be a potential therapeutic target for CRC.

CDX2 as a Predictive Biomarker Involved in Immunotherapy Response Suppresses Metastasis through EMT in Colorectal Cancer.

Background: Studies have confirmed that Caudal Type Homeobox 2 (CDX2) plays a tumor suppressor role in colorectal cancer (CRC) and as a prognostic and predictive marker for colorectal cancer. The epithelial to mesenchymal transition (EMT) is a transdifferentiation process, providing migratory and invasive properties to cancer cells during tumor progression. However, the role of CDX2 during the activation of EMT in CRC maintains controversial. Aim: To investigate whether CDX2 is associated with EMT in CRC. Methods: Forty-six CRC patients were included in the study. Expressions of CDX2, E-cadherin, and N-cadherin in all CRC patients were detected by IHC. ROC assays were applied to detect cut-off points for IHC scores to distinguish high and low expressions of CDX2 in 46 CRC samples. The prognostic value of CDX2 was statistically analyzed. MTT, Western blot, invasion, and migration assays in vitro were employed to explore the function of CDX2. Results: We observed that high expressions of CDX2 and E-cadherin as well as low expressions of N-cadherin were significantly correlated with favorable prognosis. The levels of CDX2 protein exhibited a positive associated with E-cadherin while negative correlation with N-cadherin. Then, the low expression of CDX2 and high expression of CA199 in combination are positively related with poor prognosis. Overexpression of CDX2 reduced expression of MMP-2 and diminished cell proliferation, invasion, and migration, while knockdown CDX2 enhanced MMP-2 expression and increased cell proliferation, invasion, and migration in HCT-116 cells. CDX2 was correlated with expression of EMT markers. Overexpression of CDX2 suppressed the EMT markers indicating that CDX2 suppresses CRC cell viability, invasion, and metastasis through inhibiting EMT. Finally, we found that the expression of CDX2 was negatively associated with Th1 cells, macrophages, Th2 cells, cytotoxic cells, T cells, and T helper cells. Conclusions: These results indicated CDX2 as prognostic biomarkers involved in immunotherapy response for CRC. CDX2 loss promotes metastasis in CRC through a CDX2-dependent mechanism.

A nomogram combining plasma fibrinogen and systemic immune­inflammation index predicts survival in patients with resectable gastric cancer.

Hyperfibrinogenemia and cancer-associated systemic inflammatory response are strongly associated with cancer progression and prognosis. We aimed to develop a novel prognostic score (F-SII score) on the basis of preoperative fibrinogen (F) and systemic immunoinflammatory index (SII), and evaluate its predictive value in patients with resectable gastric cancer (GC). Patients diagnosed with GC between January 2012 and December 2016 were reviewed. The F-SII score was 2 for patients with a high fibrinogen level (≥ 3.37 g/L) and a high SII (≥ 372.8), whereas that for patients with one or neither was 1 or 0, respectively. A high F-SII score was significantly associated with older patient age, a high ASA score, large tumor size, large proportion of perineural invasion, and late TNM stage. Multivariate analysis indicated that the F-SII score, histological grade, and TNM stage were independent factors for overall survival (OS). The Harrell's concordance index (C-index) of a nomogram based on the F-SII score and several clinicopathological manifestations was 0.72, which showed a better predictive ability for OS than the TNM stage alone (0.68). In conclusion, preoperative F-SII may serve as a useful predictive factor for OS and refine outcome prediction for patients with resectable GC combined with traditional clinicopathological analysis.

Obesity Potentiates Esophageal Squamous Cell Carcinoma Growth and Invasion by AMPK-YAP Pathway.

Obesity could increase the risk of esophageal squamous cell carcinoma (ESCC) and affect its growth and progression, but the mechanical links are unclear. The objective of the study was to explore the impact of obesity on ESCC growth and progression utilizing in vivo trials and cell experiments in vitro. Diet-induced obese and lean nude mice were inoculated with TE-1 cells, then studied for 4 weeks. Serum glucose, insulin, leptin, and visfatin levels were assayed. Sera of nude mice were obtained and then utilized to culture TE-1. MTT, migration and invasion assays, RT-PCR, and Western blotting were used to analyze endocrine effect of obesity on cell proliferation, migration, invasion, and related genes expression of TE-1. Obese nude mice bore larger tumor xenografts than lean animals, and were hyperglycemic and hyperinsulinemic with an elevated level of leptin and visfatin in sera, and also were accompanied by a fatty liver. As for the subcutaneous tumor xenograft model, tumors were more aggressive in obese nude mice than lean animals. Tumor weight correlated positively with mouse body weight, liver weight of mice, serum glucose, HOMA-IR, leptin, and visfatin. Obesity prompted significant TE-1 cell proliferation, migration, and invasion by endocrine mechanisms and impacted target genes. The expression of AMPK and p-AMPK protein decreased significantly (P < 0.05); MMP9, total YAP, p-YAP, and nonphosphorylated YAP protein increased significantly (P < 0.05) in the cells cultured with conditioned media and xenograft tumor from the obese group; the mRNA expression of AMPK decreased significantly (P < 0.05); YAP and MMP9 mRNA expression increased significantly (P < 0.05) in the cells exposed to conditioned media from the obese group. In conclusion, the altered adipokine milieu and metabolites in the context of obesity may promote ESCC growth in vivo; affect proliferation, migration, and invasion of ESCC cells in vitro; and regulate MMP9 and AMPK-YAP signaling pathway through complex effects including the endocrine effect.

Obesity accelerates murine gastric cancer growth by modulating the Sirt1/YAP pathway.

A previous study from our group using an in vivo model demonstrated that diet induced-obesity increases the risk of gastric cancer and may prompt its growth. However, the molecular mechanisms underlying this association remain unclear and require further investigation. The aim of the present study was to investigate the potential molecular mechanisms through which obesity affects gastric cancer growth. In a subcutaneous mouse model, tumors were significantly larger in obese mice compared with non-obese and lean mice. In addition, markedly increased levels of Sirt1 and YAP protein were observed in the nucleus of cells from subcutaneous tumors from obese mice compared with those from lean mice. Murine forestomach carcinoma (MFC) cells treated with 5% sera from obese mice exhibited significantly increased expression of Sirt1 and YAP compared with MFC cells treated with sera from lean mice. In addition, a positive correlation was observed between Sirt1 expression and YAP expression, and between Sirt1 expression and serum visfatin levels in mice. These results suggested that diet-induced obesity could promote murine gastric cancer growth by modulating the Sirt1/YAP signaling pathway.

Penehyclidine ameliorates acute lung injury by inhibiting Toll-like receptor 2/4 expression and nuclear factor-κB activation.

The aim of the present study was to investigate the effect of penehyclidine (PHC) on endotoxin-induced acute lung injury (ALI), as well as to examine the mechanism underlying this effect. A total of 60 rats were randomly divided into five groups, including the control (saline), LPS and three LPS + PHC groups. ALI was induced in the rats by injection of 8 mg lipopolysaccharide (LPS)/kg body weight. The rats were then treated with or without PHC at 0.3, 1 or 3 mg/kg body weight 1 min following LPS injection. After 6 h, serum levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 were determined by ELISA. In addition, the mRNA expression levels of toll-like receptor (TLR)2 and TLR4 were examined by reverse transcription-quantitative polymerase chain reaction in the lung tissue samples, and nuclear factor (NF)-κB p65 protein expression levels were examined by western blot analysis. The results demonstrated that lung injury was ameliorated by treatment with PHC (1 and 3 mg/kg body weight) as compared with treatment with LPS alone. Injection of LPS significantly increased the mRNA expression levels of TLR2 and TLR4, as well as the protein expression levels of NF-κB p65 in the lung tissue samples. Serum levels of TNF-α and IL-6 were also upregulated by LPS injection. Treatment of the rats with PHC following LPS injection suppressed the LPS-induced increase in TLR2/4 mRNA and NF-κB p65 protein expression levels. PHC also inhibited the increase in TNF-α and IL-6 serum levels. In addition, PHC reduced LPS-induced ALI and decreased the serum levels of TNF-α and IL-6, possibly by downregulating TLR2/4 mRNA expression and inhibiting NF-κB activity, and consequently alleviating the inflammatory response.

Ligation of Intersphincteric Fistula Tract vs Ligation of the Intersphincteric Fistula Tract Plus a Bioprosthetic Anal Fistula Plug Procedure in Patients With Transsphincteric Anal Fistula: Early Results of a Multicenter Prospective Randomized Trial.

OBJECTIVE: The purpose of this study was to compare the ligation of intersphincteric fistula tract (LIFT) with an additional plug (LIFT-plug) in the treatment of transsphincteric anal fistula. SUMMARY BACKGROUND DATA: Both LIFT and LIFT-plug are recently reported effective alternatives of transsphincteric anal fistula. METHODS: This multicenter prospective randomized study (NCT01478139) was conducted at 5 university hospitals throughout China. A total of 235 patients were randomly assigned to undergo LIFT (118 patients) or LIFT-plug (117 patients) between March 2011 and April 2013. The primary outcome measured was primary healing rate at 6 months postoperatively and healing time. Secondary outcomes included recurrence rate, postoperative pain, and incontinence rate. RESULTS: The LIFT procedure showed shorter operative time than the LIFT-plug procedure (26.7 min vs 28.5 min, P = 0.03). Median healing time was 22 days in LIFT-plug group vs 30 days in LIFT group (P < 0.001). The difference in visual analog scale scores across all time points was not statistically significant between the groups (P = 0.13). The primary healing rate was higher in LIFT-plug group than in LIFT group [94.0% (95% confidence interval 89.7%-98.3%) vs 83.9% (95% confidence interval 77.2%-90.6%), P < 0.001]. There were no reported incontinence and recurrence within the follow-up period of 6 months. CONCLUSIONS: In patients with transsphincteric anal fistulas, both LIFT-plug and LIFT are simple, safe, and effective procedures. LIFT-plug has the advantage of a higher healing rate, less healing time, and a lower early postoperative pain score.

ß-elemene enhances the radiosensitivity of gastric cancer cells by inhibiting Pak1 activation.

AIM: To explore the potential of ß-elemene as a radiosensitizer for gastric cancer cells and the underlying mechanisms. METHODS: SGC7901, MKN45, MKN28, N87, and AGS human gastric cancer cell lines were used to screen for radioresistant gastric cancer cell lines. A 3-(4,5-dimeth-ylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay was used to determine the effects of ß-elemene and IPA-3 on cell viability in MKN45 and SGC7901 gastric cancer cell lines. A clonogenic survival assay and annexin V-FITC/PI apoptosis detection assay were used to evaluate cellular radiosensitivity and radiation-induced cell death, respectively. A proteomic method, isobaric tags for relative and absolute quantitation (iTRAQ), was employed to screen the proteins regulated by ß-elemene pretreatment prior to ionizing radiation (IR) in SGC7901 gastric cancer cell line. IPA-3 was used as a specific small molecule inhibitor of p21-activated protein kinase 1 (Pak1) to target Pak1 signaling. Protein levels of PAK1IP1 (p21-activated protein kinase-interacting protein 1), total Pak1 (t-Pak1), phospho-Pak1 (T423), phospho-ERK1/2 (Thr202/Tyr204), and cleaved caspase-3 (17 kDa) were assessed by western blotting. RESULTS: MKN45 and SGC7901 gastric cancer cell lines were relatively more resistant to IR. ß-elemene pretreatment decreased clonogenic survival following IR in MKN45 and SGC7901 gastric cancer cell lines. Additionally, ß-elemene pretreatment prior to IR increased radiation-induced cell death compared with IR alone in MKN45 (10.4% ± 0.9% vs 34.8% ± 2.8%, P < 0.05) and SGC7901 (11.6% ± 0.9% vs 46.7% ± 5.2%, P < 0.05) human gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Through iTRAQ analysis and western blot validation, we found that ß-elemene upregulated PAK1IP1 and downregulated phospho-Pak1 (T423) and phospho-ERK1/2 in SGC7901 gastric cancer cells. IR increased the level of phospho-Pak1 (T423). Pretreatment with ß-elemene decreased radiation-induced Pak1 and ERK1/2 phosphorylation. Inhibition of Pak1 using IPA-3 decreased clonogenic survival following IR. In addition, IPA-3 increased radiation-induced cell death in MKN45 (13.4% ± 0.3% vs 26.6% ± 1.0%, P < 0.05) and SGC7901 (16.0% ± 0.6% vs 37.3% ± 1.7%, P < 0.05) gastric cancer cell lines, respectively, consistent with the level of cleaved caspase-3 (17 kDa). Western blotting showed that IPA-3 decreased radiation-induced Pak1 and ERK1/2 phosphorylation. CONCLUSION: This is the first demonstration that ß-elemene enhances radiosensitivity of gastric cancer cells, and that the mechanism involves inhibition of Pak1 signaling.

High glucose promotes gastric cancer chemoresistance in vivo and in vitro.

The aim of the present study was to determine whether gastric cancer chemoresistance was increased under high glucose conditions by means of a clinical case study and experimental cytology. The expression of nicotinamide phosphoribosyltransferase (Nampt), silent information regulator 1 (sirt1), p53, p-glycoprotein (P-gp) and topoisomerase (topo)-IIα was evaluated in gastric cancer tissues and gastric cancer with diabetes tissues by immunohistochemistry. Subsequently, the survival time of the patients was assessed. For further investigation, the human gastric cancer cell line SGC7901 was subjected to different glucose concentrations and the aforementioned proteins were detected using reverse transcription-quantitative polymerase chain reaction and western blot analysis. Finally, cell sensitivity to chemotherapy treatment was examined in order to elucidate the role of high glucose in MDR. Positive expression of Nampt, Sirt1, p53, P-gp and Topo-IIα was observed to be higher in gastric cancer with diabetes patients compared with gastric cancer patients (P=0.01, 0.003, 0.0025, 0.016 and 0.336, respectively) with reduced survival time. Similar results were observed in SGC7901 cells. Additionally, cell proliferation rates of SGC7901 cells increased at glucose concentrations of 4,500 and 9,000 mg/l. Notably, the inhibition rates of 5-fluorouracil on cells decreased over 48 h when treated with 4,500 and 9,000 mg/l glucose compared with 1,000 mg/l. In conclusion, patients suffering from gastric cancer and diabetes exhibited greater negative effects, such as a poorer response to chemotherapy and had a lower survival time. High glucose conditions promoted gastric cancer cell proliferation and reduced susceptibility to chemotherapy drugs. These data provided a potential diagnostic and therapeutic strategy for gastric cancer chemoresistance.

Anticancer effects of ß-elemene in gastric cancer cells and its potential underlying proteins: a proteomic study.

Gastric cancer is a common malignancy with a poor prognosis. ß-elemene is a broad-spectrum anticancer drug extracted from the traditional Chinese medicinal herb Curcuma wenyujin. In the present study, we investigated the anticancer effects of ß-elemene in gastric cancer cells and the potential proteins involved. Human SGC7901 and MKN45 gastric cancer cells were treated with different concentrations of ß-elemene. Cell viability, clonogenic survival and apoptotic cell death were assessed. ß-elemene inhibited viability and decreased clonogenic survival of gastric cancer cells in a dose-dependent manner. Apoptosis induction contributed to the anticancer effects. We then employed a proteomic method, isobaric tags for relative and absolute quantitation (iTRAQ), to detect the proteins altered by ß-elemene. In total, 147 upregulated proteins and 86 downregulated proteins were identified in response to ß-elemene treatment in SGC7901 gastric cancer cells. Among them, expression of p21-activated protein kinase­interacting protein 1 (PAK1IP1), Bcl-2-associated transcription factor 1 (BTF) and topoisomerase 2-α (TOPIIα) were validated by western blot analyses and the trends were consistent with iTRAQ results. Top pathways involved in ß-elemene treatment in SGC7901 gastric cancer cells included ribosome signaling, peroxisome proliferator-activated receptors (PPARs) signaling pathway, regulation of actin cytoskeleton, phagosome, biosynthesis and metabolism of some amino acids. Collectively, our results suggest a promising therapeutic role of ß-elemene in gastric cancer. The differentially expressed proteins provide further insight into the potential mechanisms involved in gastric cancer treatment using ß-elemene.

Diet-induced obesity promotes murine gastric cancer growth through a nampt/sirt1/c-myc positive feedback loop.

Obesity increases the risk of gastric cancer and may promote its growth, as was recently demonstrated by our novel in vivo mouse model. However, the underlying mechanisms of this correlation remain unclear. The purpose of this study was to investigate the precise effects of obesity on gastric cancer growth and to elucidate the potential molecular mechanisms. Diet-induced obese mice were insulin-resistant, glucose-intolerant and had high serum visfatin concentration. In the subcutaneous mouse model, tumors were more aggressive in diet-induced obese mice compared with lean mice. Tumor weights showed a significant positive correlation with mouse body weights, as well as serum insulin and visfatin concentrations. Immunohistochemical staining showed that the expression levels of iNampt, Sirt1 and c-MYC proteins were upregulated in the subcutaneous tumors from obese mice compared to those from lean animals. Furthermore, obesity not only prompted significantly murine forestomach carcinoma cell migration, proliferation, but also affected cellular apoptosis and cell cycle by endocrine mechanisms. These were associated with increased expression of the pro-survival nampt/sirt1/c-myc positive feedback loop confirmed by RT-PCR and western blotting. These results suggested that diet-induced obesity could promote murine gastric cancer growth by upregulating the expression of the nampt, sirt1 and c-myc genes.

Diet-induced obesity potentiates the growth of gastric cancer in mice.

Obesity increases the risk of gastric cancer and may affect its development and progression, however, the mechanisms underlying this association are completely unknown. The purpose of the current study was to investigate the effect of obesity on gastric cancer growth by adopting a novel in vivo model. Diet-induced obese and lean mice were inoculated with murine forestomach carcinoma cells, and studied for 2 weeks. Tumor histology, cellular proliferation and apoptosis were evaluated. Serum glucose, insulin, visfatin levels and peripheral CD3(+), CD4(+/-), CD8(+/-) lymphocytes were assayed. All mice were alive and developed no metastasis, a greater number of obese mice developed palpable tumors than lean mice. The tumors from obese mice had a larger volume, greater intratumoral adipocyte mass, and exhibited a higher proliferation and reduced apoptosis rate compared to those of lean animals. Both serum insulin and visfatin concentrations correlated positively with tumor proliferation and negatively with tumor apoptosis. Obese mice had a significantly lower level of CD3(+), CD3(+)CD4(+) T lymphocytes, and a lower level of CD4(+)/CD8(+) in peripheral blood compared to these lymphocyte levels in the lean mice. In conclusion, the altered adipocytokine milieu and insulin resistance observed in obesity may lead directly to alterations in the tumor microenvironment and cell immunity for avoiding cancer, thereby, promoting gastric cancer survival and growth.

[The expression of nicotinamide phosphoribosyl transferase and vascular endothelial growth factor-A in gastric carcinoma and their clinical significance].

OBJECTIVES: To study the expression of nicotinamide phosphoribosyl transferase (Nampt) and vascular endothelial growth factor-A (VEGF-A) in gastric carcinoma and investigate their correlations to clinicopathologic features and prognostic significance. METHODS: The proteins of Nampt and VEGF-A in 68 specimens of gastric carcinoma and 59 specimens normal gastric tissue were detected by immunohistochemistry during January 2000 to December 2004, and the 68 patients were followed up. RESULTS: Nampt protein was detected in the cytoplasm of both tissues, and Nampt in gastric carcinoma (13 ± 5) were significantly higher than that in normal gastric tissue (6 ± 3) (t = 7.46, P < 0.01). The expression of Nampt was correlated to invasive depth (F = 4.693, P = 0.034), lymph node metastasis (F = 4.027, P = 0.049), clinical TNM stage (F = 9.979, P = 0.002), but not to gender, age, tumor location, tumor size, differentiation (P > 0.05). The expression of Nampt is correlated with survival of patients that underwent surgical resection for gastric cancer. The survival rate of patients in negative of Nampt was very higher than that of the positive patients, and its co-expression with VEGF-A showed a trend towards poorer survival. The positive correlation was found between the expression of Nampt and VEGF-A in gastric carcinoma (r = 0.293, P = 0.015). CONCLUSIONS: The expression of Nampt is positively correlated to that of VEGF-A in gastric carcinoma. The correlation between the expression of Nampt and VEGF-A in gastric carcinoma plays an important role cooperatively in carcinogenesis, development and metastasis of gastric carcinoma.

Side population cells isolated from KATO III human gastric cancer cell line have cancer stem cell-like characteristics.

AIM: To investigate whether the side population (SP) cells possess cancer stem cell-like characteristics in vitro and the role of SP cells in tumorigenic process in gastric cancer. METHODS: We analyzed the presence of SP cells in different human gastric carcinoma cell lines, and then isolated and identified the SP cells from the KATO III human gastric cancer cell line by flow cytometry. The clonogenic ability and self-renewal were evaluated by clone and sphere formation assays. The related genes were determined by reverse transcription polymerase chain reaction. To compare tumorigenic ability, SP and non-side population (NSP) cells from the KATO III human gastric cancer cell line were subcutaneously injected into nude mice. RESULTS: SP cells from the total population accounted for 0.57% in KATO III, 1.04% in Hs-746T, and 0.02% in AGS (CRL-1739). SP cells could grow clonally and have self-renewal capability in conditioned media. The expression of ABCG2, MDRI, Bmi-1 and Oct-4 was different between SP and NSP cells. However, there was no apparent difference between SP and NSP cells when they were injected into nude mice. CONCLUSION: SP cells have some cancer stem cell-like characteristics in vitro and can be used for studying the tumorigenic process in gastric cancer.

Overexpression of Nampt in gastric cancer and chemopotentiating effects of the Nampt inhibitor FK866 in combination with fluorouracil.

Nicotinamide phosphoribosyltransferase (Nampt), an enzyme involved in the NAD⁺ salvage pathway, is over-expressed and important in the carcinogenesis in several types of cancers. The expression of Nampt and its role in gastric cancer remain largely unknown. In this study, using real-time PCR and Western blotting we found that Nampt was overexpressed at the mRNA and protein levels, respectively, in established gastric cancer cells and human gastric cancer tissues. The specific Nampt inhibitor FK866 repressed gastric cancer cell proliferation, as assessed by MTT assay. Using transwell and soft agar clonogenic assays, we also found that FK866 suppressed gastric cancer cell migration and anchorage-independent growth, respectively. These inhibitory effects of FK866 were accompanied by significantly decreased expression of VEGF, MMP2, MMP9 and NF-κB. As determined by MTT assay and flow cytometry, FK866 also increased the chemo-sensitivity of gastric cancer cells to fluorouracil by greater inhibition of cell proliferation and the induction of apoptosis. Our findings indicate that Nampt may be a new therapeutic target for gastric cancer.

Side population cells from HXO-Rb44 retinoblastoma cell line have cancer-initiating property.

AIM: To ascertain whether side population (SP) cells in HXO-Rb44 retinoblastoma cell line have cancer stem cell-like property in vitro and in vivo. METHODS: We analyzed and sorted SP from HXO-Rb44 retinoblastoma cell line by Hoechst 33342 staining on flow cytometry. SP and NSP cells were determined their ability of proliferation and self-renewal by SP reanalysis, soft agar assay and tumor sphere assay in vitro. Clone formation was detected by seeding HXO-Rb44 and HXO-Rb44 -RFP cells into soft agar. The expression of ABCG2, MDRI, Bmi-1 and Oct-4 was determined by RT-PCR between SP and non-SP (NSP) cells. Moreover, they were injected into nude mice to determine their tumorigency in vivo. RESULTS: SP from HXO-Rb44 retinoblastoma cell line could grow clonally in soft agar assays and form tumor spheres from single cells in conditioned media. The expressions of ABCG2, MDRI, Bmi-1 and Oct-4 were significantly higher in SP than NSP cells. As few as SP cells resulted in tumor formation in 6 of 12 injected sites, however, the injection of NSP cells failed to form new tumor. CONCLUSION: SP cells isolated by Hoechst 33342 from the HXO-Rb44 retinoblastoma cell line had property of high tumorigency in vivo and in vitro. Therefore, SP might be a target while developing retinoblastoma therapies.

Nampt/PBEF/visfatin and cancer.

Nampt/PBEF/visfatin is the rate-limiting enzyme that catalyzes the first step in NAD biosynthesis from nicotinamide and regulates growth, apoptosis and angiogenesis of mammalian cells. This enzyme was originally cloned as a putative cytokine shown to enhance the B cell precursor maturation in the presence of IL-7 and stem cell factor. A number of cancers have increased expression of Nampt/PBEF/visfatin, which regulates a variety of different signaling pathways such as PI3K/Akt, ERK1/2 and STAT3. FK866/APO866 and CHS828/GMX1777 are two known inhibitors of Nampt/PBEF/visfatin and have been evaluated as anticancer agents in the clinic. This review will focus on its role in carcinogenesis and cancer progression and its inhibitors as therapeutic target for cancer treatment.

Upregulation of human DNA binding protein A (dbpA) in gastric cancer cells.

AIM: To determine the effect of human DNA binding protein (dbpA) on the biology of gastric cancer cells. METHODS: DbpA expression was analyzed by Western blot analysis and immunofluorescence staining in gastric cancer tissues and cell lines. A dbpA-specific small interference (si) RNA was designed and synthesized. Suppressive effect of siRNA on dbpA expression was assessed by real-time RT-PCR. Transwell migration and colony formation assays were used to assess the inhibitory effects of dbpA siRNA on cell invasion and tumorigenesis in vitro. Drug-sensitivity was evaluated using a conventional 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The expression of dbpA was upregulated in gastric cancer tissues and cell lines as compared to adjacent normal tissues or gastric epithelial cells. siRNA treatment successfully silenced dbpA expression. Silencing of dbpA increased expression of E-cadherin, decreased expression of adenomatous polyposis coli (APC), beta-catenin and cyclin D1, but had no effect on expression of NF-kappaB. Silencing of dbpA also suppressed cell invasion and colony formation of SGC7901 cells, and enhanced their chemosensitivity to 5-fluorouracil. CONCLUSION: DbpA plays an important role in the pathogenesis and development of gastric cancer, and the process involves E-cadherin, APC, beta-catenin and cyclin D1. Silencing of dbpA might be a novel therapeutic strategy for increasing chemosensitivity to 5-fluorouracil in gastric cancer.

[Expression of heparin-binding epidermal growth factor-like growth factor in patients with gastric carcinoma].

OBJECTIVE: To investigate the expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in patients with gastric carcinoma in different stages. METHODS: The expressions of HB-EGF protein and mRNA in normal gastric tissues, metaplasic intestinal mucosa, early-stage gastric cancer and advanced-stage gastric cancer tissues were detected by immunohistochemistry and in situ hybridization. RESULTS: HB-EGF expression was only detected in the parietal cells of the gastric fundic glands and in gastrin cells of the pyloric glands in normal gastric tissues. Weak HB-EGF expression was detected in the epithelial cells of the gastric mucosa in intestinal metaplasic mucosa, and the expression increased in all layers of the gastric mucosa in early-stage gastric cancer. Intense HB-EGF expression was observed in advanced gastric cancer. CONCLUSION: Increased HB-EGF expression may be implicated in the pathogenesis and development of gastric carcinoma.

Identification of side population cells from bladder cancer cells by DyeCycle Violet staining.

Side population (SP) cells can be used to identify putative cancer stem cells (CSC), but this technique is hampered by the requirement for an ultraviolet (UV) laser source. DyeCycle Violet reagent (DCV) is a DNA-binding dye that can be used in the common violet laser diode (VLD)-equipped flow cytometer. In this paper, we analyzed SP cells from several bladder cancer cell lines using either Hoechst 33342 or DCV staining. The Hoechst 33342-stained SP cells were identified with a UV-equipped flow cytometer, while the DCV-stained SP cells were identified with a VLD-equipped flow cytometer. DCV staining was also used to sort SP and non-SP (NSP) cells from SW780 cells. Further analysis revealed that SP cells could give rise to both SP and NSP cells. The colony-forming ability of SP cells was significant greater than that of NSP cells. When injected into nude mice, as few as 1 x 10(3) SP cells could initiate tumors in eight of twelve injection sites. In contrast, the injection of NSP cells into nude mice failed to initiate tumors. RT-PCR data showed that the expression of ABCG2, MDRI, Bmi-1 and Oct-4 differed between SP and NSP cells, suggesting that SP cells possess some stem cell characteristics. We conclude that SP cells identified by DCV staining are capable of asymmetric division, self-renewal and tumor initiation. Our study also indicates that DCV is a useful reagent for the identification of SP cells.