The association between ephrin receptor-A1 expression and survival in patients with cancer: a meta-analysis.

Background: Ephrin receptor-A1 (EPHA1) participates in various developmental processes by engaging in cell adhesion, migration, and tissue boundary formation. EPHA1 is also associated with cancer progression and poor prognosis. However, the results of individual studies were inconsistent. Therefore, we aimed to systematically evaluate the association between survival and EPHA1 expression in patients with cancer. Methods: We searched electronic databases including PubMed, Embase, Scopus, and the Cochrane library until February 8, 2022. The pooled hazard ratio (HR) with 95% confidence interval (CI) was calculated to explore the relationship between EPHA1 expression and survival in patients with cancer. Funnel plots and Egger's regression tests were conducted to evaluate publication bias, and sensitivity analysis was performed to determine the reliability of the pooled results. Results: Eight studies with 1079 cancer patients were enrolled. EPHA1 expression was associated with progression-free survival (PFS) (HR 1.79, 95% CI: 1.49-2.15, P<0.001). EPHA1 expression was also associated with poor overall survival (HR 2.23, 95% CI: 1.42-3.51, P<0.001), higher tumor stage [odds ratio (OR) 1.74, 95% CI: 1.15-2.61, P=0.008], and lymph node metastasis (OR 1.88, 95% CI: 1.24-2.87, P=0.003) in patients with gastric cancer. Discussion: EPHA1 expression was significantly associated with PFS in patients with cancer.

Prognostic Value of NOX4 Expression in Cancer Patients: A Systematic Review and Meta-analysis.

Background: Recent studies have shown that nicotinamide adenosine dinucleotide phosphate oxidase 4 (NOX4) is related to cancer development, proliferation, invasion, epithelial-to-mesenchymal transition, and metastasis. The prognostic value of NOX4 expression although has been reported in various cancers, it remains unclear as several studies have reported conflicting results. Therefore, the purpose of this study was to systematically investigate the prognostic value of NOX4 expression in cancer patients. Method: Appropriate studies were collected by searching the PubMed, EMBASE, and Cochrane library databases, and the prognostic value of NOX4 expression in cancer patients was assessed through a meta-analysis. Results: Nine eligible studies involving 2675 cancer patients were included in this meta-analysis. We found that NOX4 expression is related to prognosis in cancer patients. In particular, high expression of NOX4 was significantly associated with overall survival in patients with gastrointestinal cancer (hazard ratio [HR]: 1.83, 95% confidence interval [CI]: 1.39-2.42, p < 0.001). Conclusion: NOX4 expression is significantly correlated with overall survival in patients with gastrointestinal cancer, indicating that it could be a potential prognostic marker.

SNU-333 Cells as an Appropriate Cell Line for the Orthotopic Renal Cell Carcinoma Model.

Objective: To investigate a feasible candidate for an appropriate cell line for the orthotopic renal cell carcinoma (RCC) model. Methods: Normal human proximal tubule cells (HK-2) and RCC cells were used for MTT assay, Western blotting, sphere-forming assay, and orthotopic injection of BALB/c-nude mice. Immunohistochemistry was adopted in tissue arrays and orthotopic tumors. Results: Primary RCC cells showed resistance to a GPX4 inhibitor compared to HK-2 and to metastatic RCC cells, Caki-1. Caki-2 and SNU-333 cells showed resistance to ferroptosis via increased GPX4 and FTH1, respectively. RCC cells showed increased αSMA, in which Caki-2 and SNU-333 cells exhibited different epithelial-mesenchymal transition and cancer stem cell markers. Caki-1 and SNU-333 cells formed spheres in vitro and orthotopic tumor masses in vivo. The injected SNU-333 tumor only showed high intensities of CD10 and PAX8, markers of renal origin. Conclusion: SNU-333 cell line exhibited resistance via iron metabolism and stemness, and had tumor-initiating capacities in vitro and in vivo. These results suggest that among the cells tested, SNU-333 cells were the most promising for the establishment of an orthotopic RCC model for further researches.

Increased CD9 expression predicts favorable prognosis in human cancers: a systematic review and meta-analysis.

BACKGROUND: CD9 is implicated in cancer progression and metastasis by its role in suppressing cancer cell proliferation and survival. However, the prognostic and clinicopathological significance of CD9 expression is controversial. Therefore, the current meta-analysis was conducted to determine the prognostic and clinicopathological significance of CD9 expression in cancer patients. METHODS: Eligible studies were selected through database search of PubMed, Embase and Cochrane library up to April 5 2020. The necessary data were extracted from the included studies. Pooled hazard ratio (HR) and odds ratio (OR) with 95% confidence interval (CI) were calculated to evaluate the prognostic and clinicopathological significance of CD9 expression in cancer patients. RESULTS: A total of 17 studies consisting of 3456 cancer patients were included in this meta-analysis. An increased CD9 expression was significantly associated with a more favorable overall survival (OS) (HR 0.47, 95% CI 0.31-0.73, p = 0.001) and disease-free survival (DFS) (HR 0.48, 95% CI 0.30-0.79, p = 0.003). In subgroup analysis of cancer type, an increased CD9 expression was associated with increased OS in breast cancer and digestive system cancer, and with increased DFS in head and neck cancer and leukemia/lymphoma. Additionally, an increased CD9 expression significantly correlated with lower overall stage (OR 0.45, 95% CI 0.29-0.72, p = 0.001). CONCLUSION: An increased CD9 expression was associated with favorable survival in cancer patients suggesting that CD9 expression could be a valuable survival factor in cancer patients.

Expression profile of intestinal stem cell and cancer stem cell markers in gastric cancers with submucosal invasion.

Cancer stem cells (CSCs) are believed to be responsible for tumor growth, invasion, and metastasis. Submucosal invasion, which greatly enhances metastasis risk, is a critical step in gastric cancer (GC) progression. To identify stem cell-related markers associated with submucosal invasion and lymph node (LN) metastasis in GCs, we investigated the expression of candidate CSC markers (CD133, CD44, and ALDH1A) and intestinal stem cell (ISC) markers (EPHB2, OLFM4, and LGR5) in early GCs that manifested submucosal invasion. We discovered that EPHB2 and LGR5 expression was frequently confined to the basal area of the lamina propria (basal pattern) in mucosal cancer, and the proportion of stem cell marker-positive cells substantially increased during submucosal invasion. CD44 expression showed a focal pattern, ALDH1A was predominantly expressed diffusely, and there was no expansion of CD44 or ALDH1A expression in the submucosal cancer cells. Unexpectedly, no CSC markers showed any associations with LN metastasis, and only loss of EPHB2 expression was associated with increased LN metastasis. Treatment of RSPO2, a niche factor, along with Wnt 3a, to GC cells led to increased EPHB2 and LGR5 mRNA levels. RNA in situ hybridization confirmed specific RSPO2 expression in the smooth muscle cells of the muscularis mucosa, suggesting that RSPO2 is responsible for the increased expression of ISC markers in GC cells at the basal areas. In summary, no stem cell markers were associated with increased LN metastasis in early GCs. Conversely, isolated EPHB2 expression was associated with lower LN metastasis. EPHB2 and LGR5 showed a basal distribution pattern along with enhanced expression in submucosal invading cells in early GCs, which was induced by a niche factor, RSPO2, from the muscularis mucosa.

A Prospective Validation and Observer Performance Study of a Deep Learning Algorithm for Pathologic Diagnosis of Gastric Tumors in Endoscopic Biopsies.

PURPOSE: Gastric cancer remains the leading cause of cancer-related deaths in Northeast Asia. Population-based endoscopic screenings in the region have yielded successful results in early detection of gastric tumors. Endoscopic screening rates are continuously increasing, and there is a need for an automatic computerized diagnostic system to reduce the diagnostic burden. In this study, we developed an algorithm to classify gastric epithelial tumors automatically and assessed its performance in a large series of gastric biopsies and its benefits as an assistance tool. EXPERIMENTAL DESIGN: Using 2,434 whole-slide images, we developed an algorithm based on convolutional neural networks to classify a gastric biopsy image into one of three categories: negative for dysplasia (NFD), tubular adenoma, or carcinoma. The performance of the algorithm was evaluated by using 7,440 biopsy specimens collected prospectively. The impact of algorithm-assisted diagnosis was assessed by six pathologists using 150 gastric biopsy cases. RESULTS: Diagnostic performance evaluated by the AUROC curve in the prospective study was 0.9790 for two-tier classification: negative (NFD) versus positive (all cases except NFD). When limited to epithelial tumors, the sensitivity and specificity were 1.000 and 0.9749. Algorithm-assisted digital image viewer (DV) resulted in 47% reduction in review time per image compared with DV only and 58% decrease to microscopy. CONCLUSIONS: Our algorithm has demonstrated high accuracy in classifying epithelial tumors and its benefits as an assistance tool, which can serve as a potential screening aid system in diagnosing gastric biopsy specimens.

CXCR3 expression as a prognostic factor in gastric cancer: a meta-analysis.

BACKGROUND: CXC chemokine receptor 3 (CXCR3) plays a critical role in tumorigenesis, and CXCR3 expression is associated with prognosis in many cancers. Recently, CXCR3 expression is recognized as a potential prognostic factor for patients with gastric cancer. In this study, we analyzed the prognostic significance of CXCR3 expression in gastric cancer. METHODS: We conducted a meta-analysis after selecting eligible studies through a literature search. We calculated pooled results to assess the associations between CXCR3 expression and overall survival (OS) and clinicopathological factors for gastric cancer. RESULTS: The pooled hazard ratio (HR) with 95% confidence interval (CI) between high expression of CXCR3 and OS was 0.46 (95% CI 0.30-0.71, P<0.001), suggesting that high expression of CXCR3 was associated with a favorable OS. High expression of CXCR3 was significantly correlated with younger age [odds ratio (OR) 0.67, 95% CI: 0.49-0.91, P=0.011], lower tumor grade (OR 0.46, 95% CI: 0.29-0.73, P=0.001), absence of lymph node metastasis (OR 0.47, 95% CI: 0.31-0.71, P<0.001), and lower Tumor-Node-Metastasis stage (OR 0.51, 95% CI: 0.35-0.74, P<0.001). CONCLUSIONS: High expression of CXCR3 was associated with better survival and may be a potential prognostic factor for patients with gastric cancer patients.

The relationship between hepatoma-derived growth factor and prognosis in non-small cell lung cancer: A systematic review and meta-analysis.

BACKGROUND: Hepatoma-derived growth factor (HDGF) promotes cancer progression and metastasis by interacting with vascular endothelial growth factor, thereby inducing epithelial-to-mesenchymal transition and angiogenesis. Recent studies have correlated increased HDGF levels with poor prognosis in various malignancies, including lung cancer. This meta-analysis systematically assessed the prognostic significance of HDGF expression in patients with non-small cell lung cancer (NSCLC). METHODS: Eligible studies were identified by searching literature in PubMed, Embase, Scopus, and the Cochrane library until June 2020. The pooled hazard ratio (HR) or odds ratio (OR) with 95% confidence interval (CI) was determined to assess the relationship between HDGF expression and clinical outcome in patients with NSCLC. RESULTS: The pooled HRs between high HDGF expression and clinical outcome were 2.20 (95% CI 1.75-2.76, P < .001) and 2.77 (95% CI 1.79-4.29, P < .001) for overall survival and disease-free survival, respectively. High HDGF expression was significantly correlated with a larger tumor size (OR 1.59, 95% CI 1.02-2.46, P = .040). CONCLUSION: HDGF expression is related to clinical outcome and may be a prognostic marker in patients with NSCLC.

Prognostic Value of CD63 Expression in Solid Tumors: A Meta-analysis of the Literature.

BACKGROUND: CD63 has been described as a key factor in extracellular vesicle production and endosomal cargo sorting, and there have been certain reports suggesting an association between CD63 expression and survival in patients with tumors including gastric, colon and lung cancer. However, the prognostic value of CD63 expression remains contradictory. Hence, we performed this meta-analysis to assess the prognostic value of CD63 expression in solid tumors. MATERIALS AND METHODS: Eligible studies were collected by searching the PubMed, Embase and Cochrane libraries. The hazard ratio (HR) with 95% confidence interval (CI) were evaluated to reveal the association between CD63 expression and survival in solid tumors. RESULTS: Five studies with a total of 1,454 patients were included. The HR evaluating CD63 expression on survival was 1.34 (95%CI=0.92-1.97, p=0.129). In subgroup analysis, the HRs of lung cancer and other tumors were 0.50 (95% CI=0.32-0.77, p=0.002) and 2.16 (95% CI=1.93-2.42, p<0.001) respectively. CD63 expression was significantly associated with poor disease-specific survival (HR=1.69, 95% CI=1.15-2.49, p=0.008), but not with disease-free survival and overall survival. Also, there was a significant association between CD63 expression with poor survival in the group of sample size more than 150 patients (HR=2.15, 95% CI=2.92-2.41, p<0.001), but not in the group of sample size with fewer than 150 patients. CONCLUSION: This meta-analysis suggested that CD63 expression may be a potential prognostic marker in solid tumors.

Prognostic and clinicopathological roles of programmed death-ligand 1 (PD-L1) expression in thymic epithelial tumors: A meta-analysis.

BACKGROUND: Programmed death-ligand 1 (PD-L1) is one of the immune checkpoint proteins, and plays an important role in the progression and microenvironment of cancer. PD-L1 expression has been associated with poor survival in many cancers. Several studies have also shown an association between PD-L1 expression and the prognosis of patients with thymic epithelial tumors (TETs). In this study, we systematically evaluated the prognostic and clinicopathological roles of PD-L1 expression in TETs. METHODS: We searched the literature through PubMed, Embase and Cochrane library and chose the eligible studies, and subsequently performed a meta-analysis to evaluate the prognostic and clinicopathological roles of PD-L1 expression in TETs. RESULTS: Six of the 75 articles found in the literature were selected. PD-L1 expression was significantly related to unfavorable overall survival (hazard ratio 1.52, 95% confidence interval [CI]: 1.01-2.30, P = 0.046) in TETs. PD-L1 expression was significantly associated with male gender (odds ratio [OR] 1.55, 95% CI: 1.08-2.22, P = 0.017) and higher Masaoka stage (OR 3.93, 95% CI: 2.44-6.32, P < 0.001). CONCLUSIONS: PD-L1 expression was correlated with unfavorable prognosis in TETs, indicating PD-L1 expression could help determine the prognosis of TET patients.

SMOC2, an intestinal stem cell marker, is an independent prognostic marker associated with better survival in colorectal cancers.

We aimed to investigate the expression profile of SPARC-related modular calcium-binding protein 2 (SMOC2) during colorectal cancer (CRC) progression and assess its prognostic impact in CRC patients. In our study, we showed that SMOC2 transcript level was higher in CRC samples than in normal mucosa (P = 0.017); this level was not associated with candidate cancer stem cell markers (CD44, CD166, CD133, and CD24) or intestinal stem cell markers (LGR5, ASCL2, and EPHB2) except for OLFM4 (P = 0.04). Immunohistochemical analysis showed that SMOC2-positive cells were confined to the crypt bases in the normal intestinal mucosa, hyperplastic polyps, and sessile serrated adenomas, whereas traditional serrated adenomas and conventional adenomas exhibited focal or diffuse distribution patterns. In total, 28% of 591 CRCs were positive for SMOC2, but SMOC2 positivity had negative correlations with lymphatic invasion (P = 0.002), venous invasion (P = 0.002), and tumor stage (P < 0.001). However, a positive association with nuclear ß-catenin expression was seen. Furthermore, while upregulated SMOC2 expression was maintained during the adenoma-carcinoma transition, it decreased in cancer cells at the invasive front but did not decline further during lymph node metastasis. SMOC2 positivity showed no correlations with molecular abnormalities, including microsatellite instability, CpG island methylator phenotype, and mutations of KRAS and BRAF. In addition, we showed comprehensively that SMOC2 positivity is an independent prognostic marker for better clinical outcomes in a large cohort of CRC patients (P = 0.006). In vitro studies also demonstrated that induced SMOC2 expression in DLD1 cells exerts a suppressive role in tumor growth as well as in migration, colony, and sphere formation abilities. Taken together, our results suggest SMOC2 as a candidate tumor suppressor in CRC progression.

Prognostic significance of Rab27 expression in solid cancer: a systematic review and meta-analysis.

Rab27 is an essential molecule of vesicle fusion and trafficking in exosome secretion process, which plays important roles in cancer progression and metastasis. Recent studies reported that Rab27 expression is also associated with cancer prognosis. Therefore, we performed a meta-analysis to reveal the prognostic significance of Rab27 expression in solid cancer. Data were extracted by searching on PubMed, Embase and Cochrane library until February 15 2020. Pooled hazard ratio (HR) with confidence interval (CI) was calculated to evaluate the association between Rab27 expression and survival in solid cancer. Ten studies with 1434 cancer patients were including for this meta-analysis. High expression of Rab27 was associated with poor survival (HR 2.67, 95% CI 1.52-4.69, p = 0.001). High expression of Rab27A was significantly associated with lymph node metastasis (HR 1.53, 95% CI 1.00-2.34, p = 0.048). High expression of Rab27B was significantly correlated with lymph node and distant metastasis (HR 2.15, 95% CI 1.56-2.95, p < 0.001; HR 6.80, 95% CI 3.12-14.85, p < 0.001), and higher TNM stage (HR 2.55, 95% CI 1.78-3.65, p < 0.001). This meta-analysis revealed that Rab27 expression could be a potential prognostic marker in solid cancer.

Ephrin Receptor B2 Expression May Be a Prognostic Marker for Patients With Cancer: A Meta-analysis.

BACKGROUND: Recent studies have revealed that ephrin receptor (EPH) is implicated in important signal transduction of cancer development and progression. EPHB2 is expressed in human cancer, and reported to be related to the prognosis of colorectal, gastric and breast cancer. This meta-analysis was systematically assessed the prognostic roles of EPHB2 expression in patients with cancer. PATIENTS AND METHODS: PubMed, Embase and Cochrane library were searched for eligible studies up to May 2020. Pooled hazard ratio (HR) and 95% confidence interval (CI) were calculated to evaluate the relationship of EPHB2 expression with overall and disease-free survival in patients with cancer. RESULTS: The pooled HRs for low expression of EPHB2 were 1.65 (95% CI=1.30-2.09, p<0.001) and 1.63 (95% CI=1.33-1.99, p<0.001) for overall and disease-free survival, respectively. Low expression of EPHB2 was significantly correlated with higher tumor grade and stage [odds ratio (OR)=3.04, 95% CI=1.70-5.42, p<0.001; and OR=1.82, 95% CI=1.11-2.99, p=0.018], lymph node metastasis (OR=2.13, 95% CI=1.64-2.77, p<0.001), and higher overall stage (OR=2.14, 95% CI=1.71-2.69, p<0.001). CONCLUSION: EPHB2 expression may be a valuable prognostic marker for patients with cancer.

Expression Profile and Prognostic Significance of EPHB3 in Colorectal Cancer.

The protein tyrosine kinase Ephrin type-B receptor 3 (EPHB3) is expressed in cells at the base of intestinal crypts, acting as a cellular guide in the maintenance of intestinal crypt architecture. We aimed to investigate the expression profile of EPHB3 in colorectal precancerous lesions and colorectal cancers (CRCs), and assess its prognostic value. EPHB3 expression was higher in CRCs than in normal mucosa and was associated with the intestinal stem cell markers EPHB2, OLFM4, LRIG1, and a proposed cancer stem cell marker, CD44. Enhanced EPHB3 expression significantly declined during the transformation from adenoma to carcinoma and as the tumor invaded into deeper tissue layers. Namely, a substantial reduction of EPHB3 expression was observed in the budding cancer cells at the invasive tumor fronts, which was more extensive than E-cadherin downregulation. In an azoxymethane/dextran sulfate sodium-induced, colitis-associated, CRC model, EPHB3 expression increased along with tumor development. In a large cohort of CRC patients, EPHB3 positivity was observed in 24% of 610 CRCs and was negatively correlated with tumor differentiation, lympho-vascular invasion, and tumor, node, and metastasis stages. EPHB3 was positively associated with microsatellite instability but was associated with neither CpG island methylation, nor with KRAS and BRAF mutations. Notably, EPHB3 positivity was associated with better clinical outcomes, although it was not an independent prognostic marker. Overexpression of EPHB3 in the colon cancer cell line, DLD1, led to decreased cell growth and migration and reduced mitogen-activated protein kinase signaling. Taken together, our data demonstrate the suppressive role of EPHB3 in CRC progression.

Downregulation of SMOC2 expression in papillary thyroid carcinoma and its prognostic significance.

Secreted Protein Acidic and Rich in Cysteine (SPARC)-related modular calcium-binding protein-2 (SMOC2), a secreted matricellular protein, is reported to be involved in various processes related to cancer progression such as regulating the cell cycle, angiogenesis, and invasion. However, its expression and prognostic significance in papillary thyroid carcinomas (PTCs) remains unknown. Using immunohistochemistry, we evaluated the expression profile of SMOC2 and its prognostic value in a large cohort of PTCs. Real time-PCR analysis with fresh-frozen tissues showed that SMOC2 mRNA expression in PTCs was substantially lower than the expression in matched non-cancerous thyroid tissues, consistent with the results from thyroid cancer cell lines. Immunohistochemical analysis demonstrated that SMOC2 was normally present in thyroid follicular epithelial cells and the expression level was maintained in nodular hyperplasia. However, SMOC2 expression was significantly lower in lymphocytic thyroiditis and follicular tumors including follicular adenomas and carcinomas. In particular, 38% of PTCs exhibited a complete loss of SMOC2 expression, which was associated with the presence of BRAF (V600E) mutation. Moreover, SMOC2 further declined during lymph node metastasis in PTCs. DNA methylation chip analysis revealed one hypermethylated CpG site in the promoter region of SMOC2 gene, suggesting an epigenetic regulation of SMOC2 in PTCs. Remarkably SMOC2 positivity was associated with improved recurrence-free survival along with female sex, tumor size, and the N stage. However, SMOC2 was not identified as an independent prognostic marker in multivariate analyses. Taken together, SMOC2 expression is significantly down-regulated in PTCs and SMOC2 positivity is closely associated with better clinical outcomes, suggesting that SMOC2 can be a prognostic marker in PTC patients.

Expression profile of sonic hedgehog signaling-related molecules in basal cell carcinoma.

Basal cell carcinoma (BCC) is the most common human cancer, characterized by aberrant activation of the hedgehog (HH) signaling pathway resulting from mutations in the patched 1 (PTCH1) or smoothened (SMO) genes. In the present study, to uncover the expression profile of HH signaling-related molecules, we thoroughly examined the mRNA and protein expression levels of six molecules including GLI1, GLI2, PTCH1, PTCH2, SHH, and SMO in BCC and various other cutaneous tumors. Real-time PCR analysis demonstrated that BCC showed remarkably enhanced mRNA expression of all HH molecules, except SMO compared to other skin tumors. However, immunohistochemical analysis revealed that only GLI1 protein was specifically upregulated in BCC, while the other HH-related proteins did not show any significant differences between the tumors. Notably, other skin malignancies such as squamous cell carcinoma, sebaceous carcinoma, and malignant melanoma showed no GLI1 expression and there was no difference in GLI1 expression between the BCC subtypes. In addition, GLI1 and GLI2 expression were strongly associated with the hair follicle stem cell markers, LGR4 and LGR5, which are known target genes of the Wnt pathway. Our results suggest that GLI1 has the potential to be a diagnostically useful marker for differentiating BCC from other skin malignancies and an interaction between the HH and Wnt signaling pathways may be involved in the development of BCCs.

Prognostic Significance of EPHB2 Expression in Colorectal Cancer Progression.

BACKGROUND: A receptor tyrosine kinase for ephrin ligands, EPHB2, is expressed in normal colorectal tissues and colorectal cancers (CRCs). The aim of this study was to investigate EPHB2 expression over CRC progression and determine its prognostic significance in CRC. METHODS: To measure EPHB2 mRNA and protein expression, real-time polymerase chain reaction and immunohistochemistry were performed in 32 fresh-frozen and 567 formalin-fixed paraffin-embedded CRC samples, respectively. We further investigated clinicopathological features and overall and recurrence-free survival according to EPHB2 protein expression. RESULTS: The EPHB2 level was upregulated in CRC samples compared to non-cancerous tissue in most samples and showed a strong positive correlation with AXIN2. Notably, CD44 had a positive association with both mRNA and protein levels of EPHB2. Immunohistochemical analysis revealed no difference in EPHB2 expression between adenoma and carcinoma areas. Although EPHB2 expression was slightly lower in invasive fronts compared to surface area (p < .05), there was no difference between superficial and metastatic areas. EPHB2 positivity was associated with lymphatic (p < .001) and venous (p = .001) invasion, TNM stage (p < .001), and microsatellite instability (p = .036). Kaplan-Meier analysis demonstrated that CRC patients with EPHB2 positivity showed better clinical outcomes in both overall (p = .049) and recurrence-free survival (p = .015). However, multivariate analysis failed to show that EPHB2 is an independent prognostic marker in CRCs (hazard ratio, 0.692; p = .692). CONCLUSIONS: Our results suggest that EPHB2 is overexpressed in a subset of CRCs and is a significant prognostic marker.

Expression Profile of LGR5 and Its Prognostic Significance in Colorectal Cancer Progression.

We investigated the expression profile of leucine-rich, repeat-containing, G-protein-coupled receptor 5 (LGR5) during colorectal cancer (CRC) progression and determined the prognostic impact of LGR5 in a large cohort of CRC samples. LGR5 expression was higher in CRCs than in normal mucosa, and was not associated with other cancer stem cell markers. LGR5 positivity was observed in 68% of 788 CRCs and was positively correlated with older age, moderately to well-differentiated cells, and nuclear ß-catenin expression. Enhanced LGR5 expression remained persistent during the adenoma-carcinoma transition, but markedly declined in the budding cancer cells at the invasive fronts, which was not due to altered wingless-type mouse mammary tumor virus integration site family (Wnt) or epithelial-mesenchymal transition signaling. LGR5 showed negative correlations with microsatellite instability and CpG island methylator phenotype, and was not associated with KRAS or BRAF mutation. Notably, LGR5 positivity was an independent prognostic marker for better clinical outcomes in CRC patients. LGR5 overexpression attenuated tumor growth by decreasing ERK phosphorylation along with decreased colony formation and migration abilities in DLD1 cells. Likewise, knockdown of LGR5 expression resulted in a decline in the colony-forming and migration capacities in LoVo cells. Taken together, our data suggest a suppressive role of LGR5 in CRC progression.

FOXO1 Suppression is a Determinant of Acquired Lapatinib-Resistance in HER2-Positive Gastric Cancer Cells Through MET Upregulation.

PURPOSE: Lapatinib is a candidate drug for treatment of trastuzumab-resistant, human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC). Unfortunately, lapatinib resistance renders this drug ineffective. The present study investigated the implication of forkhead box O1 (FOXO1) signaling in the acquired lapatinib resistance in HER2-positive GC cells. MATERIALS AND METHODS: Lapatinib-resistant GC cell lines (SNU-216 LR2-8) were generated in vitro by chronic exposure of lapatinib-sensitive, HER2-positive SNU-216 cells to lapatinib. SNU-216 LR cells with FOXO1 overexpression were generated by stable transfection of a constitutively active FOXO1 mutant (FOXO1A3). HER2 and MET in SNU-216 LR cells were downregulated using RNA interference. The sensitivity of GC cells to lapatinib and/or cisplatin was determined by crystal violet assay. In addition, Western blot analysis, luciferase reporter assay and reverse transcription-polymerase chain reaction were performed. RESULTS: SNU-216 LR cells showed upregulations of HER2 and MET, but downregulation of FOXO1 compared to parental SNU-216 cells. FOXO1 overexpression in SNU-216 LR cells significantly suppressed resistance to lapatinib and/or cisplatin. In addition, FOXO1 negatively controlled HER2 and MET at the transcriptional level and was negatively controlled by these molecules at the post-transcriptional level. A positive crosstalk was shown between HER2 and MET, each of which increased resistance to lapatinib and/or cisplatin. CONCLUSION: FOXO1 serves as an important linker between HER2 and MET signaling pathways through negative crosstalks and is a key regulator of the acquired lapatinib resistance in HER2-positive GC cells. These findings provide a rationale for establishing a novel treatment strategy to overcome lapatinib resistance in a subtype of GC patients.

FOXO1 reduces tumorsphere formation capacity and has crosstalk with LGR5 signaling in gastric cancer cells.

Gastric cancer (GC) is a major of cause of cancer-related death and is characterized by its heterogeneity and molecular complexity. FOXO1 is a transcription factor that plays a key role in GC growth and metastasis. However, the implication of FOXO1 in GC cell stemness has been elusive. This study, for the first time, demonstrates that FOXO1 regulates GC cell stemness in association with LGR5. FOXO1 expression was significantly lower in GC tumorsphere cells than in adherent GC cells. FOXO1 silencing and overexpression promoted and inhibited the tumorsphere formation capacity of GC cells, respectively. Additionally, there was an inverse correlation between FOXO1 and GC stem cell marker LGR5 in human GC specimens. Further in vitro and in vivo experiments showed that negative crosstalk between these two molecules exists and that LGR5 silencing reversed the FOXO1 shRNA-induced tumorsphere formation even without FOXO1 restoration. Taken together, our results suggest that FOXO1 inhibits the self-renewal capacity of GC cells through interaction with LGR5. Thus, FOXO1/LGR5 signaling pathway may provide a novel targeted therapy for GC.