Interaction between CD133 and PI3K-p85 promotes chemoresistance in gastric cancer cells.

Chemoresistance in gastric cancer is the leading cause of tumor recurrence and poses a substantial therapeutic challenge. The stem cell biomarker CD133 has been implicated in drug resistance of tumor-initiating cells in a number of cancers including gastric cancer. Therefore, we investigated the molecular mechanism of CD133-associated multidrug resistance in gastric cancer cells. Using CD133 overexpressing and knockdown gastric cancer cell lines, we demonstrated that loss of CD133 significantly increased the growth inhibition of chemotherapeutic agents; whereas, overexpression significantly reduced growth inhibition. Furthermore, CD133 knockdown significantly reduced the enzymatic activity of phosphatidylinositol-3 kinase (PI3K) and the expression of P-glycoprotein (P-gp), B-cell lymphoma 2 (BCL2), and phosphorylated-protein kinase B (p-AKT), but elevated the expression of BCL2 associated X (BAX). Conversely, overexpression of CD133 significantly increased PI3K enzymatic activity, expression of P-gp, BCL2, and p-AKT, and decreased BAX expression. The PI3K/AKT inhibitor LY294002 mirrored the effects of loss of CD133; whereas, the PI3K/AKT activator epidermal growth factor reproduced the effects of CD133 overexpression. To identify the interaction between CD133 and PI3K, we used site-directed mutagenesis to mutate individual tyrosine residues of CD133. We found that binding between CD133 and p85, the regulatory subunit of PI3K, was significantly reduced when tyrosine 852 was mutated. In summary, we have demonstrated that CD133 activates the PI3K/AKT signal transduction pathway through direct interaction with PI3K-p85, resulting in multidrug resistance of gastric cancer cells. These results suggest that the interaction between CD133 and PI3K-p85 may offer a novel therapeutic target in multidrug resistant gastric cancer.

Large Wolffian adnexal tumor of the ovary: A case report and literature review.

Female Wolffian adnexal tumor (WAT) is a rare neoplasm arising from the remnants of the mesonephric duct and <100 cases have been reported globally. The present case report describes a 73-year-old female patient with WAT in the left ovary which, to the best of our knowledge, is the largest benign WAT tumor to be reported. In addition, the present case report reviewed previous studies on the clinical characteristics and therapy for WAT and the surgery methods for female WAT of ovary were summarized. WATs are typically benign; however, a number factors may increase the risk of malignancy.

Metadherin regulates actin cytoskeletal remodeling and enhances human gastric cancer metastasis via epithelial-mesenchymal transition.

Metadherin (MTDH) can be recruited to mature tight junction complexes, and it regulates mesenchymal marker protein expression in many tumors and promote cancer metastasis. This study investigated the influence of MTDH expression on gastric cancer and to elucidate the potential mechanisms by which MTDH regulates actin cytoskeletal remodeling and enhances human gastric cancer metastasis via epithelial-mesenchymal transition (EMT). Relative MTDH mRNA expression levels were assessed by quantitative real-time PCR (Q-PCR), and MTDH protein expression levels and localization were evaluated via immunohistochemical (ICH) staining. We studied the role of MTDH in cancer cell migration and invasion by modulating MTDH expression in the gastric cancer cell lines MKN45 and AGS. We also confirmed the functions of MTDH through in vivo experiments. We found that MTDH expression levels were correlated with lymph node metastasis, TNM stages and decreased OS (P=0.002, <0.001 and 0.010, respectively) in human gastric cancer and that MTDH upregulation promoted EMT in vitro. Consistent with this finding, MTDH downregulation inhibited cell migration and invasion in vitro and suppressed tumor growth and metastasis in vivo. Furthermore, MTDH knockdown regulated actin cytoskeletal remodeling and inhibited EMT. Overall, our results provide a novel role for MTDH in regulating gastric cancer metastasis.

Bone marrow-derived mesenchymal stem cells increase drug resistance in CD133-expressing gastric cancer cells by regulating the PI3K/AKT pathway.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are recruited to primary tumours to compose the tumour microenvironment. In various cancers, CD133-positive cells have been shown to possess cancer stem cell properties that confer chemoresistance. This study aimed to investigate the role of BM-MSCs in the anti-tumour drug resistance of CD133-expressing gastric cancer cells and explore the underlying mechanisms that governing this role. We found that CD133+ gastric cancer cells displayed more resistance to chemotherapeutics than CD133- cells. In addition, BM-MSCs increased the anti-apoptotic abilities and chemoresistance of CD133+ cells via upregulation of Bcl-2 and downregulation of BAX. Mechanistically, BM-MSCs triggered activation of the PI3K/Akt signalling cascade in CD133+ cells. Blocking the PI3K/Akt pathway inhibited the promotion of chemoresistance. Furthermore, BM-MSCs enhanced the drug resistance of CD133-overexpressing cells in vitro and in vivo, but not that of CD133-knockdown cells, which demonstrated the contribution of CD133 to this process. In conclusion, we demonstrated that BM-MSCs increased the anti-apoptotic abilities and drug resistance of CD133-expressing cells via activation of the PI3K/Akt pathway following Bcl-2 upregulation and BAX downregulation, in which CD133 played a significant role. Targeting this route may help improve the efficacy of chemotherapy in gastric cancer.

Oxygenated Static Preservation of Donation after Cardiac Death Liver Grafts Improves Hepatocyte Viability and Function.

BACKGROUND: Cell therapy, such as hepatocyte transplantation (HTx), is promising for the treatment of metabolic liver diseases or as a bridge to orthotopic liver transplantation in patients with fulminant liver failure. However, one of the limitations of this therapy is the shortage of donors. The present study aims to investigate whether the two-layer method (TLM) of cold preservation with oxygenation improves the viability and activity of hepatocytes from rat donation after cardiac death (DCD) donors compared with results obtained with the University of Wisconsin (UW) solution. Moreover, we evaluated the hepatocyte function after culture or transplantation into the spleen. MATERIALS AND METHODS: We used male Sprague-Dawley rats for this study. The DCD model was induced by phrenotomy after injecting heparin. We assigned rats based on warm ischemia times of 15 and 30 min to groups S and L, respectively. Each group (n = 5) was then subdivided as follows: (1) group S: not preserved (S/N), preserved by TLM for 3 h (S/TLM3) and 12 h (S/TLM12), and in the UW solution for 3 h (S/UW3) and 12 h (S/UW12), and (2) group L: not preserved (L/N), preserved by TLM for 3 h (L/TLM3) and 12 h (L/TLM12), and in the UW solution for 3 h (L/UW3) and 12 h (L/UW12). The cell viability and function of isolated DCD hepatocytes were analyzed for culture or HTx into the spleen. RESULTS: The viability and ATP levels of DCD hepatocytes significantly improved after TLM compared with the values after preservation in cold UW solution in group S/N (p < 0.059). The levels of albumin production and urea synthesis by hepatocytes after culture were significantly higher in groups S/TLM3 and S/TLM12 than in groups S/UW3 and S/UW12 (p < 0.05), respectively. Further, serum albumin levels after HTx were also markedly higher in groups S/TLM3 and S/TLM12 than in groups S/UW3 and S/UW12. The morphological features revealed that cultured and transplanted hepatocytes remained clearly viable and maintained an expression for specific hepatic function, such as the production of albumin and glycogen. CONCLUSION: This novel method of oxygenated cold preservation of DCD livers can expand the hepatocyte donor pool for HTx and establish a wider application of this developing technique.

Contactin 1: A potential therapeutic target and biomarker in gastric cancer.

Despite advances in diagnosis and treatment, gastric cancer remains one of the most common malignant tumors worldwide, and early diagnosis remains a challenge. The lack of effective methods to detect these tumors early is a major factor contributing to the high mortality in patients with gastric cancer, who are typically diagnosed at an advanced stage. Additionally, the early detection of metastases and the curative treatment of gastric cancer are difficult to achieve, and the detailed mechanisms remain to be fully elucidated. Thus, the identification of valuable predictive biomarkers and therapeutic targets to improve the prognosis of patients with gastric cancer is becoming increasingly important. Contactin 1 (CNTN1), a cell adhesion molecule, is a glycosylphosphatidylinositol-anchored neuronal membrane protein that plays an important role in cancer progression. The expression of CNTN1 is upregulated in primary lesions, and its expression level correlates with tumor metastasis in cancer patients. The current evidence reveals that the functions of CNTN1 in the development and progression of cancer likely promote the invasion and metastasis of cancer cells via the VEGFC/FLT4 axis, the RHOA-dependent pathway, the Notch signaling pathway and the epithelial-mesenchymal transition progression. Therefore, CNTN1 may be a novel biomarker and a possible therapeutic target in cancer treatment in the near future.

Significances of contactin-1 expression in human gastric cancer and knockdown of contactin-1 expression inhibits invasion and metastasis of MKN45 gastric cancer cells.

PURPOSE: Contactin-1 (CNTN-1) has been shown to promote cancer metastasis. Previously, we have reported that the expression of CNTN-1 was upregulated in gastric cancer tissues compared with adjacent normal tissues. Here, we investigated the significance of CNTN-1 expression and its underlying mechanism of metastasis mediated by epithelial-mesenchymal transition (EMT) in gastric cancer. METHODS: The expressions of CNTN-1 and EMT-related proteins were assayed through immunohistochemical staining of pathological specimens from patients with gastric cancer. Other methods including reverse transcriptase polymerase chain reaction, Western blotting, stably transfected against CNTN-1 into MKN45 cells, migration and invasion assays in vitro and nude mouse tumorigenicity in vivo were also utilized. RESULTS: The results revealed that CNTN-1 expression was elevated and positively correlated with metastasis, EMT-related markers and poor prognosis in patients with gastric cancer. Moreover, CNTN-1 expression might associate with invasive ability to some extent in gastric cancer cell lines KATO-Ш, SGC7901 and MKN45. Knockdown of CNTN-1 expression in MKN45 cells using short hairpin RNA (shRNA) had notable effects on cell migration and invasion, rather than proliferation in vitro and in vivo. Furthermore, suppression of CNTN-1 expression altered EMT through inhibition of transcription factor Slug, rather than Snail. CONCLUSION: Our study demonstrated that the elevated CNTN-1 expression closely correlated with cancer metastasis and patient survival, and its functions seemed to be important in migration and invasion of gastric cancer cells via EMT alteration probably mediated by inhibition of Slug. CNTN-1 may be a potential therapeutic target for gastric cancer.

[Experimental study of human bone marrow mesenchymal stem cells on regulating the biological characteristics of gastric cancer cells].

OBJECTIVE: To investigate the regulatory mechanism of bone marrow mesenchymal stem cells(BMSC) on the biological profiles of KATO-III( cell lines of gastric cancer. METHODS: Transwell cubicle was applied to build the co-cultured model in non-contact style. The differences of cell proliferation and the resistance of anti-tumour drug (5-fluoropyrimidinedione, 5-FU and Cisplatin, CDDP) between co-cultured group and single cultured group were evaluated by Cell Counting Kit 8-assay(CCK-8). The invasion ability was detected by Transwell assay. The expressions of stem cell makers, apoptosis-related factors and epithelium-mesenchymal transition (EMT)-related factors were detected by RT-PCR. RESULTS: The proliferation ability of KATO-III( cells in co-cultured group was significantly stronger than that in single cultured group. The growth rate of KATO-III( cells in co-cultured group was significantly higher than that in single cultured group after treatment of 5-FU and CDDP(P<0.05). The mRNA expression level of Bcl-2 was significantly higher in co-cultured group KATO-III( cells(P<0.05), while the mRNA expression level of Bax was significantly lower in co-cultured group KATO-III( cells(P<0.05) in comparison with those in single cultured group. As compared to KATO-III( cells in single cultured group, the number of infiltrating-membrane cells was significantly higher (37.33±5.22 vs 14.56±2.54, P<0.01) in co-cultured group, and the mRNA expression levels of Snail and N-cadherin were significantly higher in co-cultured group KATO-III( cells (P<0.05), while the mRNA expression level of E-cadherin was significantly lower in co-cultured group KATO-III( cells (P<0.05). The expressions of CD133, Nanog and Sox-2 mRNA in co-cultured group KATO-III( cells were significantly higher than those in single cultured group(P<0.05). CONCLUSIONS: In co-cultured model sharing non-contact style, BMSC can enhance such properties of KATO-III( gastric cancer cells as the proliferation, the invasion and the chemoresistance. Furthermore, the regulatory mechanisms may be related to the increase of the expressions of some stem cell markers in gastric cancer cells.

Overexpression of CD133 enhances chemoresistance to 5-fluorouracil by activating the PI3K/Akt/p70S6K pathway in gastric cancer cells.

CD133 has been reported to be associated with chemoresistance in various cancer cells. The efficacy of 5-fluorouracil (5-FU), an important chemotherapeutic agent for advanced gastric cancer (GC), is limited by 5-FU resistance. Hence, the present study investigated the function of CD133 in 5-FU resistance in human GC cells. We isolated CD133+ GC cells by immunomagnetic cell sorting and CD133 expression was modulated by transfection of CD133 gene or CD133 small interfering ribonucleic acid. To assess the 5-FU cytotoxicity, Cell Counting Kit-8 was used. Expression of CD133, P-glycoprotein (P-gp), B-cell lymphoma 2 (Bcl­2), Bcl-2-associated X protein (Bax), phospho-Akt (p-Akt) and phospho-p70S6 kinase (p-p70S6K) were analyzed by western blotting. CD133, P-gp, Bcl-2 and Bax messenger ribonucleic acids were evaluated using semi-quantitative reverse transcriptase-polymerase chain reaction. Cell apoptosis was assessed by Hoechst 33258 staining. CD133+ cells were more resistant to 5-FU than CD133- cells, and showed higher expression of P-gp and Bcl-2 with lower expression of Bax. Furthermore, CD133 silencing enhanced 5-FU cytotoxicity and apoptotic characteristics, whereas CD133 overexpression increased 5-FU resistance. CD133 silencing and activation directly decreased and increased the expression of P-gp, Bcl­2, p-Akt and p-p70S6K, respectively. Notably, Akt inhibition by LY294002 restored the 5-FU cytotoxicity suppressed by CD133 overexpression, while Akt activation by epidermal growth factor reversed the 5-FU cytotoxicity enhanced by CD133 silencing. Therefore, CD133 may inhibit 5-FU-induced apoptosis by regulating the expression of P-gp and Bcl-2 family mediated by phosphoinositide 3-kinase/Akt/p70S6K pathway in GC cells.

Study on the Biological Characteristics of CD133 (+) Cells Interfered by RNA Interference in Gastric Cancer.

Background. To detect the changes of biological characteristics in gastric cancer cells interfered by CD133-specific small interfering RNA (siRNA). Methods. First to select the siRNA which has the strongest interference effect among 3 siRNAs (i.e., siRNA1, siRNA2, and siRNA3) in KATO-III cells by RT-PCR and Western blotting assays. Then, CD133(+) cells were sorted out from KATO-III cells using an immunomagnetic bead sorting method and transfected with the selected siRNA. Furthermore, the proliferating characteristics, the antichemotherapeutic assessment, Transwell invasion assay, monoclonal sphere formation assay, and subcutaneous transplanted tumor formation assay in nude mice were investigated. Results. siRNA3 showed the strongest interference effect in KATO-III cells. As compared to the uninterfered control group, the CD133(+) cells treated by siRNA3 showed significant decreases in the abilities of proliferation, invasion, clone sphere formation, and resistance to antitumour drugs as well as the weight and size of the transplanted tumor, which was nearly similar to that of CD133(-) cells. Additionally, the protein expression level of the EMT factor E-cadherin increased while those of EMT-related Snail and N-cadherin decreased in CD133(+) cells interfered by siRNA3. Conclusion. Inhibition of CD133 gene expression reduces the abilities of gastric cancer cells in proliferation, invasion, clonal sphere formation, and chemoresistance as well as tumor formation in nude mice.

[Relationship between CD133 and chemoresistance in human gastric cancer and its associated mechanism].

OBJECTIVE: To explore the relationship between CD133(+) subsets cells in human gastric cancer (GC) and molecules of drug resistance and their sensitivity to 5-FU. METHODS: Three gastric cancer cell lines therein KATO-III(, SGC7901 and MKN45 were sorted by immunomagnetic beads cell sorting method. Then above cell lines were further divided into un-sorted GC cells, CD133(+) subgroup and CD133(-) subgroup. The expressions of CD133, P-gp, Bax and Bcl-2 were determined by RT-PCR, Western blot and immunoflurescence. Meanwhile, the sensitivity to 5-FU of three subgroups was detected by CCK-8 Kit. The apoptosis induced by 5-FU in three subgroups was determined by Hoechst 33258. RESULTS: Expressions of CD133 in three CD133(+) subgroups were significantly higher than those in un-sorted GC cells and CD133(-) subgroup (all P<0.05). Expressions of P-gp and Bcl-2 in the three GC cell lines were different (all P<0.05). There were significant differences of expressions of P-gp, Bcl-2 and Bax among CD133(+) cells, un-sorted GC cells and CD133(-) cells (all P<0.05). CCK-8 detection showed that CD133(-) subgroup of MKN45 GC cell line was more sensitive than CD133(+) cells to 5-FU (P<0.05). Hoechst 33258 staining showed that there were more apoptotic cells in CD133(-) subgroup as compared to other two subgroups, and the least apoptotic cells were observed in CD133(+) subgroup of MKN45 GC cell line (P<0.05). CD133 sirna was transfected into MKN45 GC cell line and could down-regulate the expressions of CD133, P-gp, Bcl-2 and p-Akt, while the expression of Bax increased (all P<0.05). CONCLUSIONS: CD133 may contribute to the resistance of GC cells to chemotherapy drug through P-gp, Bcl-2 and Bax. PI3K/Akt signal pathway may be involved in this process.

Preliminary Study on the Expression and the Clinical Significance of CD133 in Peripheral Blood of Patients with Gastric Adenocarcinoma.

Background. Significances of CD133 mRNA in peripheral blood mononuclear cells (PBMCs) of gastric adenocarcinoma (GC) patients were investigated. Methods. Correlations of CD133 mRNA expression in PBMCs on clinicopathological parameters or CD133 protein expression were analyzed. Receiver operating characteristic curve according to bright scale value (BSV) of CD133 mRNA was used to group patients for prognosis analysis. Results. BSV of preoperative CD133 mRNA in PBMCs in GC was significantly higher than that in volunteers or in GU. Invasive depth or metastatic lymph node number for higher BSV of preoperative CD133 mRNA and invasive depth or lymphatic vessel invasion for higher BSV of postoperative CD133 mRNA in the PBMCs were identified. Patients with CD133(+) expression in primary lesion had a significantly higher expression of preoperative CD133 mRNA in the PBMCs. The expression of preoperative or postoperative CD133 mRNA in PBMCs related positively to CD133 mRNA expression in primary lesion. Patients with higher expression of preoperative or postoperative CD133 mRNA shared significantly shorter survival compared with that in lower expression group. Conclusion. Higher levels of preoperative or postoperative CD133 mRNA in PBMCs of GC correlated positively to the lymphatic metastasis and the BSV of CD133 mRNA in primary lesion, indicating the poorer survival.

Expressions and clinical significances of c-MET, p-MET and E2f-1 in human gastric carcinoma.

BACKGROUND: To investigate on the expressions and the clinical significances of hepatocyte growth factor receptor (c-MET), phosphorylated c-MET (p-MET) and e2f-1 transcription factor in primary lesion of gastric adenocarcinoma (GC). METHOD: Tissue samples from the primary lesion of GC in patients who accepted D2/D3 radical gastrectomy with R0/R1 resection were stained by immunohistochemistry of c-MET, p-MET, e2f-1 and Ki-67. The univariate and the multivariate analyses involving in clinicopathological parameters and prognostic factors were evaluated. RESULTS: The positivity rates for c-MET (66.12%, 80 cases/121 cases), p-MET (59.50%, 72 cases/121 cases), e2f-1 (38.84%, 47 cases/121 cases) and Ki-67 (72.73%, 88 cases/121 cases) in primary lesion of GC was significantly higher than that in non-cancerous tissue at 5 cm places far from the margin of primary lesion (P < 0.05, respectively). The deeper tumor invasion, the severer lymph node metastasis, the later stage of TNM and the higher expression of Ki-67 was respectively an independent risk factor for the higher expression of c-MET or p-MET, but the younger age and the shorter survival time was an independent risk factor for the higher expression of e2f-1 respectively. Survival analysis showed that the worse prognosis could be observed in the patients with the combination of both c-MET-positive and e2f-1-negative (P = 0.038) or both p-MET-positive and e2f-1-negative (P = 0.042). Cox analysis demonstrated that the severer lymphatic node metastasis and the higher positivity rate of c-MET, p-MET or e2f-1 were an independent prognosis factor respectively. The higher expression of e2f-1 was identified in patients with Stage I-II, which correlated with a shorter survival time. Survival analysis also revealed that the prognosis of patients with positive expression of e2f-1 at Stage I-II was significantly worse than that in patients with negative expression of e2f-1 (χ2 = 13.437, P = 0.001). However, in the cases with Stage III-IV, no significant difference could be identified in the prognostic comparison between positive and negative expressions of e2f-1. CONCLUSIONS: The expression of c-MET or p-MET is an independent prognosis factor. It has been observed that the higher expression of e2f-1 occurred in the early stages while the lower expression of it in the later stages in GC.

[Effect of RNA interference inhibition to expression of CD133 on tumor cell biological characteristics in KATO-III CD133(+) cells of human gastric cancer].

OBJECTIVE: To investigate the changes in proliferation, invasiveness, clone sphere formation and chemosensitivity of human gastric cancer cell lines of KATO-III CD133(+) cells transfected with small interfering RNA (siRNA) against CD133 gene. METHODS: CD133(+) cells of KATO-III cell lines were isolated by magnetic activated cell sorting (MACS). CD133 siRNA was designed and synthesized, and then transfected into KATO-III CD133(+) cells. Cell fluorescence counting under confocal laser scanning microscope was used to determine the transfection efficiency after transfection with the CD133 FITC-siRNA. The knock-down effect of the CD133 gene and expression of epithelial-mesenchymal transition (EMT)-related factors were detected by RT-PCR and Western blotting. Cell counting kit-8 assay (CCK-8), transwell chamber and colony sphere forming assay were performed to measure the variation of cell proliferative, invasive, colony formation viability and chemosensitivity to 5-FU after the above-mentioned treatment. RESULTS: The transfection efficiency was (87.7±8.1)%. The CD133 mRNA and protein expression levels in the interference group were lower than those in negative control group. Twenty-four, 48 and 72 hours after transfection, cells proliferation activity was significantly inhibited in the interference group compared with negative control group, (all P<0.01). Seventy-two hours after transfection, compared with negative control group, cells proliferation activity was reduced by (52.1±8.0)%. The invasive cell number reduced (41.7±6.0 vs. 130.3±11.0, P<0.05) and clone formation rate decreased significantly [(24.3±4.3)% vs. (45.1±6.4)%, P<0.01] in the interference group. EMT-related gene E-cadherin protein expression increased, while the Snail and N-cadherin protein expression reduced in the interference group (all P<0.01). The cells sensitivity to 5-FU was significantly enhanced in the interference group, and the cell inhibition rate of 5-Fu was (62.4±3.3)%, higher than that in negative control group [(21.5±2.2)%, P<0.01]. CONCLUSIONS: The expression of CD133 gene plays an important role in cell proliferation, invasiveness, colony formation and resistance to chemotherapy of KATO-III CD133(+) gastric cancer cells. It suggests that CD133 can be used as one of surface markers for detection of gastric cancer stem cells. Inhibition of CD133 expression may be a promising way for gastric cancer biotherapy.

[CD133 promotes the invasion and metastasis of gastric cancer via epithelial-mesenchymal transition].

OBJECTIVE: To examine the association between CD133 expression and invasion of gastric cancer, and to elucidate whether CD133 can promote the invasion and metastasis of gastric cancer via epithelial-mesenchymal transition (EMT). METHODS: The CD133(+) and CD133(-) KATO-III( cells were sorted by magnetic activated cell sorting (MACS). The invasion ability was detected by Transwell method. RT-PCR and Western blot were used to detect the expression of EMT-related factors in KATO-III( cells before and after CD133 was knocked out by siRNA method. The expressions of CD133 and EMT-related proteins of cancer and adjacent normal tissues in 50 patients with gastric cancer were detected by Western blot, and correlations among protein expressions were also analyzed. RESULTS: As compared to CD133(-) cells, the number of broken-membrane cells was significantly higher (67.7±10.5 vs. 13.3±6.8, P=0.001) and the invasion ability was stronger (P<0.05) in CD133(+) cells, while the mRNA expression levels of Snail and N-cadherin were significantly higher in CD133(+) cells (0.311±0.015 vs. 0.223±0.016, P=0.040; 0.581±0.020 vs. 0.270±0.018,P=0.004), and the protein expression levels of Snail and N-cadherin were significantly higher in CD133(+) cells as well (0.513±0.015 vs. 0.179±0.023, P=0.030; 0.538±0.028 vs. 0.202±0.032, P=0.020), but E-cadherin mRNA and protein levels were significantly lower in CD133(+) cells (0.231±0.009 vs. 0.460±0.015, P=0.040; 0.426±0.030 vs. 0.748±0.027, P=0.040). After CD133 knock-out, the expressions of Snail and N-cadherin were down-regulated (P<0.05) and the expression of E-cadherin was up-regulated (P<0.05). As compared to normal mucosal tissues, the protein expression levels of Snail, N-cadherin and CD133 in gastric cancer tissues were significantly higher(0.635±0.119 vs. 0.485±0.116, P=0.029; 0.599±0.114 vs. 0.259±0.108, P=0.020; 0.754±0.154 vs. 0.329±0.134, P=0.001), while the protein expression of E-cadherin in gastric cancer tissues was lower (0.378±0.123 vs. 0.752±0.156, P=0.003). The protein expressions of Snail and N-cadherin were positively correlated with CD133 expression (r=0.278, P=0.048; r=0.406, P=0.003) and the protein expression of E-cadherin was negatively correlated with CD133 expression (r=-0.504, P=0.000). CONCLUSION: CD133(+) cells in primary lesion of gastric cancer have relatively higher invasion ability, which may promote the metastasis of gastric cancer via up-regulation of EMT-related factors.

Expression and significances of contactin-1 in human gastric cancer.

Background. This study aimed at determining the relationship between vascular endothelial growth factor-C (VEGF-C), vascular endothelial growth factor receptor-3 (VEGFR-3), and contactin-1 (CNTN-1) expression in gastric cancer (GC). Methods. The expression level of CNTN-1 mRNA and CNTN-1 protein of 33 cases was determined using RT-PCR and Western Blot. And 105 cases were immunohistochemically examined for VEGF-C, VEGFR-3, and CNTN-1 expressions. Assessment of lymphatic vessel density (LVD) was also performed by D2-40 immunostaining. Then we analyzed the relationships between VEGF-C, VEGFR-3, and CNTN-1, as well as their correlations with clinicopathologic features, LVD, and survival time. Results. The positivity rate of VEGF-C, VEGFR-3, and CNTN-1 in primary tumor was 56.19%, 64.76%, and 58.09%. The expression of CNTN-1 significantly correlated with VEGF-C (P < 0.001) and VEGFR-3 (P < 0.001). All of them were closely related to TNM stage, lymphatic invasion, and lymph node involvement (P < 0.05). LVD was significantly correlated with VEGF-C (P = 0.001), VEGFR-3 (P = 0.011), and CNTN-1 expression (P < 0.001). VEGF-C, VEGFR-3, and CNTN-1 expression significantly associated with poorer prognosis (P < 0.001, P = 0.034, P = 0.012, resp.). Conclusion. CNTN-1 associated with VEGF-C and VEGFR-3 expression in GC. All of them correlated with lymphatic metastasis, which might play an important role in the lymphatic invasion via lymphangiogenesis pathway in GC.

[Sorting of CD133(+) subset cells in human gastric cancer and the identification of their tumor initiating cell-like properties].

OBJECTIVE: To sort CD133(+) subset cells in human gastric cancer (GC) and to identify their tumor initiating cell-like properties. METHODS: The tissues of GC and normal tissues adjacent to GC were obtained from 50 patients. Samples were stained for CD133 by immunohistochemistry. Likewise, assessments of CD133 were undertaken by Western blot. Flow cytometry was used to determine the proportion of CD133(+) cells in four GC cell lines therein the KATO-III was sorted by magnetic activated cell sorting (MACS) method. The growing characteristics and the tumorigenic ability of CD133(+) cells were evaluated in vitro and in vivo. Meanwhile, the growth of single cells in suspension culture was observed and expression of stem cell-specific marker were determined using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The expression of CD133 was demonstrated on the cell membranes in the mucosa and submucosa of primary GC, which were higher than those in the normal gastric tissues adjacent to cancer (P<0.05). Four GC cell lines including KATO-III, SGC-7901, AGS and MKN-45 were found to contain (28 ± 2)%, (17 ± 2)%, (6 ± 2)%, and (4 ± 2)% of CD133(+) cells respectively. In addition, the purity of CD133(+) cells isolated from KATO-III by MACS was (91 ± 3)% and up to(95 ± 2)% after 1-week culture. CCK-8 detection showed that population doubling time of the CD133(+) cells was (21 ± 3)h, significantly shorter than that of the CD133(-) cells[(40 ± 8)h, P<0.05]. Notably, there was a remarkable difference of tumor formation rate between CD133(+) cells (100%), non-sorted cells (80%), and CD133(-) cells(0). The average mass and volume of tumor in group of CD133(+) cells was larger and heavier than those in non-sorted cells (P<0.05, P<0.05). Furthermore, the single cell proliferated well, formed the big sphere and semi-quantitative RT-PCR showed expression of stem cell markers such as Oct-4, Nanog, Sox-2, Musashi-1 and EGFR. CONCLUSIONS: CD133 protein expression in primary lesions is higher than those in the normal gastric tissues. CD133(+) subset cells can be isolated, purified, and amplified in human GC, and possess some properties including the ability of self-renewal, proliferation, and higher tumorigenic ability in vivo and can express some stem cell markers.

Study on lymph node metastasis correlated to lymphangiogenesis, lymphatic vessel invasion, and lymph node micrometastasis in gastric cancer.

BACKGROUND: This study aimed to evaluate the clinical significance of lymphangiogenesis, lymph vessel invasion (LVI), and lymph node (LN) micrometastasis (LNMM) in patients with gastric cancer. METHODS: The influences of the expression levels of LVI, lymph vessel density (LVD) by D2-40 immunohistochemical (IHC) staining (n=68), LNMM (including CK 20 and CK pan immunostainings, n=51) on the clinicopathologic profiles and the prognosis were analyzed. RESULTS: The higher positive rate of LVI-IHC was related to deeper invasion (P=0.044), later TNM stage (P=0.003), and more extensive LN metastasis (LNM, P=0.000). The level of LVD was significantly associated with venous invasion (P=0.037), later TNM stage (P=0.020), positive LVI-HE (P=0.040), positive LVI-IHC status (P=0.001), and severer LNM (P=0.001). Better prognosis in LVI negative group than LVI positive group has been identified. The survival rate of the group with LVD≥15/field was significantly lower than that in the group with LVD≤14/field (P=0.032). Invasion depth, N stage, LNM, blood vessel invasion, or LVI was respectively an independent prognostic factor to 3-y survival rate. The incidence of patients with LNM and metastasized LNs increased respectively from 74.5% (38/51) by HE staining to 88.2% (45/51) by CK immunostaining and from 32.0% (253/791) to 41.5% (328/791) (P=0.001). The increment of LNMM was correlated to larger tumor diameter (P=0.001), deeper invasion (P=0.018), LNM (P=0.001) and later TNM stage (P=0.012), positive LVI (P=0.04). Meanwhile, the evaluation on LNMM revealed the migration of LN stage (N(0)→N(1) in seven patients, N(1)→N(2) in six patients, and N(2)→N(3) in one patient), and TNM stage (I(b)→II in four patients, II→III(a) in 4 patients, III(a)→III(b) in 3 patients, and III(b)→IV in one patient). Survival analysis demonstrated that better prognosis in patients without LNM and/or LNMM. CONCLUSION: Our immunohistochemical analyses using antibodies of D2-40 and CK, including both CK 20 and CK pan, detected a higher incidence of LVIs and LNMs in gastric cancer specimens. This study shows close correlations among lymphangiogenesis related factors, such as LVI, LVD, and LNMM, and patients' prognosis after surgery. Therefore, immunohistochemical evaluations of these factors could be used for the accurate determination of tumor aggressiveness.

Expressions and clinical significances of CD133 protein and CD133 mRNA in primary lesion of gastric adenocacinoma.

BACKGROUND: To study on expressions and clinical significances of CD133 protein and CD133 mRNA in primary lesion of gastric adenocarcinoma (GC). METHODS: Expressions of CD133 protein by immunostaining (99 cases) and CD133 mRNA by semi-quantitative RT-PCR (31 cases) were detected in primary lesion and in noncancerous gastric mucosa tissue (NCGT). Correlations of CD133 protein expression with clinicopathological parameters and post-operative survival were analyzed. Relations of CD133 mRNA level with Ki-67 labeling index (LI), and lymphatic metastasis were assessed too. RESULTS: Brown particles indicating CD133 protein positivity occurred in some parts of tumor cells and epithelium. Expressive percentage of CD133 protein positivity was significantly higher in subgroups with >5 cm diameter (P = 0.041), later TNM stage (P = 0.044), severer lymph node metastasis (P = 0.017), occurrences of lymphatic invasion (P = 0.000) and vascular invasion (P = 0.000) respectively. Severer invasion depth (P = 0.011), lymph node metastasis occurrence (P = 0.043) and later TNM stage (P = 0.049) were the independent risk factors for CD133 protein expression. Average brightness scale value (BSV) of CD133 mRNA was significantly higher in subgroups with >5 cm diameter (P = 0.041), lymph node metastasis occurrence (P = 0.004) and in lower Ki-67 LI (P = 0.02). Relative analysis revealed that BSV of CD133 mRNA related positively to metastatic lymphatic nodes ratio (P = 0.008) and metastatic lymph node number (P = 0.009), but negatively to Ki-67 LI (P = 0.009). Survival of positive subgroup of CD 133 protein was significantly poorer (P = 0.047). Lymph node metastasis occurrence (P = 0.042), later TNM stage (P = 0.046) and CD 133 protein positive expression (P = 0.046) were respectively the independent risk factors to survival. CONCLUSION: Higher expressive level of CD133 mRNA is associated to lower Ki-67 LI and severer lymphatic metastasis. Therefore, the expressive level of CD133 mRNA can play an appropriate role to reflect the status of lymph node metastasis and proliferation of GC. CD133 protein expression is closely related with larger tumor, later TNM stage, lymphtic metastasis and survival of GC.

Effects of bone marrow and hepatocyte transplantation on liver injury.

BACKGROUND: The therapeutic effects of bone marrow and hepatocyte transplantation were investigated regarding the treatment of retrorsine-partial hepatectomy-induced liver injury. METHODS: Analbuminemic F344alb rats were given two doses of retrorsine 2 wk apart, followed 4 wk later by transplantation with F344 rat bone marrow cells or hepatocytes immediately after a two-thirds hepatectomy. The survival rate, liver regeneration rate, liver functions, albumin-positive hepatocytes, and normal albumin gene sequences in the liver and serum albumin levels were investigated in the recipients. RESULTS: Although 65% retrorsine/partial hepatectomy-treated F344alb died between 1 and 11 d after the partial hepatectomy, only 27.5% of the animals died following bone marrow transplantation, and 50% with hepatocyte transplantation. Both bone marrow and hepatocyte transplantation ameliorated acute liver injury after a partial hepatectomy. Bone marrow transplantation yielded a very small increase in the number of albumin-positive hepatocytes in the liver, while hepatocyte transplantation resulted in massive replacement of the liver tissues by the donor hepatocytes associated with an elevation of serum albumin after an extended time. CONCLUSIONS: Both bone marrow and hepatocyte transplantation could prevent acute hepatic injury, conceivably due to a paracrine mechanism.