Overexpression of HOXA10 promotes gastric cancer cells proliferation and HOXA10(+)/CD44(+) is potential prognostic biomarker for gastric cancer.

Gastric cancer (GC) is a malignant cancer with poor prognosis. This study aims to investigate the roles of homeobox A10 (HOXA10) in GC and the correlations between HOXA10/CD44 expression and GC prognosis. Based on qRT-PCR and Western Blot analyses in 50 pairs of fresh GC samples and adjacent normal samples, it is identified that HOXA10 was significantly up-regulated in GC tissues at mRNA and protein levels. Cell proliferation, migration, and invasion were enhanced in GC cells with overexpressed HOXA10, while inhibited in cells with silenced HOXA10. Through IPA software, HOXA10 was predicted to interact with CD44 via MSN, which was preliminarily confirmed by using Western Blot. Through immunohistochemistry and tissue microarray (N=264), it is found that HOXA10 expression was significantly correlated with tumor size (P=0.011) and CD44 expression (P<0.001), while CD44 expression was significantly correlated with tumor size (P<0.001), depth of tumor invasion (P<0.001), lymph node metastasis (P<0.001), distant metastasis (P=0.001), UICC stage (P<0.001), histological differentiation (P<0.001), and HOXA10 expression (P<0.001). Additionally, the over-all survival and disease-free survival of HOXA10(+)/CD44(+) patients were dramatically decreased in comparison with that of HOXA10(+)/CD44(-), HOXA10(-)/CD44(+), or HOXA10(-)/CD44(-) patients (P<0.001), suggesting that the combinatory expression of HOXA10 and CD44 was correlated with poor GC prognosis. In conclusion, HOXA10 and CD44 might play roles in GC tumorigenesis, metastasis, and invasion. HOXA10(+)/CD44(+) expression might serve as a prognostic biomarker for GC, which needs more studies to validate.

Significance and prognostic value of Gli-1 and Snail/E-cadherin expression in progressive gastric cancer.

Abnormal activation of the hedgehog (Hh) signaling pathway has been found to be involved in the occurrence, invasion, and metastasis of cancers. Epithelial-mesenchymal transition (EMT) also plays an important role in the invasion and metastasis of cancers. However, the significance of the Hh signaling pathway and EMT in the invasion and metastasis of gastric cancer is still unclear. This study aimed to investigate the significance and prognostic value of the Hh signaling pathway and EMT in progressive gastric cancer. Immunohistochemistry was performed to detect the expression of the Hh-induced transcriptional factor Gli-1 and the EMT-related molecules Snail and E-cadherin in 121 patients with progressive gastric cancer. Histological type, depth of invasion, lymph node metastasis, and pTNM stage were also recorded. In progressive gastric cancer, Gli-1 expression increased markedly, and was closely associated with increased Snail expression and decreased E-cadherin expression. Diffuse type cancer, lymph node metastasis, and abnormal expression of E-cadherin were independent factors influencing the prognosis of patients with progressive gastric cancer. These findings suggest that abnormal activation of the Hh signaling pathway is closely related to the presence of EMT and is an important factor influencing the prognosis of patients with diffuse progressive gastric cancer.

Increased expression of TBX2 is a novel independent prognostic biomarker of a worse outcome in colorectal cancer patients after curative surgery and a potential therapeutic target.

T-box2 (TBX2) plays a critical role in embryonic development. Recently, deregulated expression of TBX2 has been implicated in several malignancies. However, the expression and the role of TBX2 in colorectal cancer (CRC) remain unclear. In this study, we found that TBX2 was obviously up-regulated in CRC in comparison with the corresponding normal mucosa at transcriptional and protein level. Up-expression of TBX2 was significantly associated with depth of tumor invasion (P = 0.006), distant metastasis (P = 0.038), advanced AJCC stage (P = 0.008), and relapse (P = 0.003). TBX2 was a significantly prognostic factor for decreased survival and increased disease recurrence independent of tumor stage(II, III stage) and functioned as a biomarker to identify prognosis of patients with CRC (OS: HR 2.154; 95% CI 1.019-4.551; P = 0.044, DFS: HR 2.253; 95% CI 1.109-4.575; P = 0.025). Furthermore, TBX2 could serve as a potential target of cancer drug therapy.

microRNA-148a suppresses human gastric cancer cell metastasis by reversing epithelial-to-mesenchymal transition.

MicroRNAs (miRNAs) are important regulators of gastric cancer development and progression. miR-148a is one of the most frequently and highly downregulated miRNAs in gastric cancer and is associated with advanced clinical stage and poor prognosis. In this study, we investigated the role of miR-148a in gastric cancer metastasis. Levels of miR-148a were determined by qRT-PCR in 60 gastric cancer samples. Cell migration and invasion assays were performed in a stably expressing miRNA-148a gastric cancer cell line established using a lentivirus expression system. Epithelial-mesenchymal transition (EMT) was evaluated using qRT-PCR and Western Blots to detect epithelial marker E-cadherin and mesenchymal marker, vimentin. Luciferase reporter assays were used to identify downstream targets and biological function of miR-148a. Gastric cancer tissue had significantly lower expression of miR-148a compared to non-tumor tissue. Low miR-148a levels were associated with lymph node metastasis, N stage, and blood vessel invasion. miR-148a overexpression inhibited metastasis of gastric cancer cells. miR-148a overexpression also downregulated vimentin expression and upregulated E-cadherin expression, suggesting that miR-148a inhibited EMT. Finally, the SMAD2 gene was identified as the direct and functional target of miR-148a. MiR-148a suppresses gastric cancer metastasis and EMT, likely via SMAD2. Restoration of miR-148a expression could have important implications in gastric cancer therapy.

Identification and validation that up-expression of HOXA13 is a novel independent prognostic marker of a worse outcome in gastric cancer based on immunohistochemistry.

Homeobox (HOX) gene family is known to be classic examples of the intimate relationship between embryogenesis and tumorigenesis. However, less is known about the involvement of HOX gene family with gastric cancerogenesis. Here, we screened the expression of HOX gene family in gastric cancers and explored the relationships between them by cDNA microarray. We found several differentially expressed HOX genes in gastric cancers, especially HOXA10 (11/12) and HOXA13 (11/12) with significantly higher expression in the cancerous tissues. Furthermore, we validated HOXA13 as a novel prognostic marker in gastric cancer based on immunohistochemistry and statistical analysis. HOXA13 expression was significantly up-regulated in cancerous tissues compared with the corresponding non-cancerous mucosa (P < 0.001). Up-expression of HOXA13 was significantly correlated with T stage (P = 0.002), M stage (P = 0.024), advanced UICC stage (P < 0.001), histological differentiation (P = 0.005), and relapse (P = 0.001). Patients with positive HOXA13 expression had a obviously lower overall survival (OS) and disease-free survival (DFS) rate than patients with negative HOXA13 expression (HR 3.331, 95 % CI 1.722-6.442, P < 0.001; HR 3.289, 95 % CI 1.703-6.351, P < 0.001, respectively). Univariate and multivariate Cox analysis confirmed that HOXA13 could serve as a significant independent prognostic factor for DFS and OS. Therefore, our results indicated that several HOX genes might be closely involved in the process of the gastric tumorigenesis. Furthermore, up-expression of HOXA13 might be associated with highly aggressive phenotype of gastric cancer. HOXA13 was a significant independent prognostic factor and could serve as a putative biomarker for diagnosis and prognosis of gastric cancer.

Downregulation of metallothionein 1F, a putative oncosuppressor, by loss of heterozygosity in colon cancer tissue.

PURPOSE: Downregulation of metallothionein (MT) genes has been reported in several tumors with discrepant results. This study is to investigate molecular mechanism of MT gene regulation in colon cancer which is characterized by tumor suppressor gene alterations. EXPERIMENTAL DESIGN: Integral analysis of microarray data with loss of heterozygosity (LOH) information was employed. Quantitative real-time PCR and immunohistochemistry were used to validate MT isoform expression in colon cancer tissues and cell lines. The effects of MT1F expression on RKO cell survival and tumorigenesis was analyzed. Bisulphite sequencing PCR (BSP) and methylation-specific PCR were employed to detect the methylation status of the MT1F gene in colon cancer tissues and cell lines. DNA sequencing was used to examine the LOH at the MT1F locus. RESULTS: MT1F, MT1G, MT1X, and MT2A gene expression was significantly downregulated in colon cancer tissue (p<0.05). Exogenous MT1F expression increased RKO cell apoptosis and inhibited RKO cell migration, invasion and adhesion as well as in vivo tumorigenicity. Downregulation of MT1F gene in majority of human colon tumor tissues is mainly through mechanism by loss of heterozygosity (p=0.001) while CpG island methylation of MT1F gene promoter region was only observed in poorly differentiated, MSI-positive RKO and LoVo colon cancer cell lines. CONCLUSIONS: MT1F is a putative tumor suppressor gene in colon carcinogenesis that is downregulated mainly by LOH in colon cancer tissue. Further studies are required to elucidate a possible role for MT1F downregulation in colon cancer initiation and/or progression.

Upregulated INHBA expression is associated with poor survival in gastric cancer.

Expression microarrays are widely used for investigating the candidate molecular targets in human cancer. While genome-wide expression signatures screened by gene set enrichment analysis (GSEA) were not performed in Chinese gastric cancer (GC). To gain new molecular targets for GC, GSEA analysis was performed. In the present study, GSEA were used to pick out differentially expressed gene sets of our database. Total RNA of paired tissue samples (n = 48) and a tissue microarray containing 132 paired tissues were used to further validate expression levels of INHBA and its correction with clinicopathological factors. Upregulated INHBA expression in gastric cancer was screened and further confirmed by qPCR and immunostaining analysis. Increased INHBA expression was significantly correlated with the diameter of cancer and depth of tumor invasion. Patients with higher expression levels of INHBA had a shorter disease-free survival rate. It was effective to gain new molecular targets for GC by GSEA analysis. INHBA may be a poor survival indicator of GC.

Biglycan expression correlates with aggressiveness and poor prognosis of gastric cancer.

Biglycan, a member of the small leucine-rich proteoglycan family, has been implicated in the development and progression of human cancers. However, the clinical significance of biglycan expression in gastric cancer has not been determined. In the present study, biglycan mRNA and protein concentrations were analyzed using quantitative realtime reverse transcription polymerase chain reaction and Western blot in 69 gastric cancer and adjacent non-tumorous tissues, respectively. Biglycan expression was further assessed using immunohistochemistry in tissue microarrays that contained 264 cases of gastric cancer, and others containing normal or metastasized lymph node tumor tissues. Biglycan was upregulated at the transcriptional and translational levels and there was a correlation between the expression of biglycan mRNA and protein (P = 0.000, κ = 0.769). Over-expression of biglycan was strongly associated with lymph node metastasis, tumor (T) classification, metastasis (M) classification, vascular invasion and Union for International Cancer Control (UICC) stage. Patients with biglycan-positive tumors had a significantly higher disease recurrence rate and poorer survival than patients with biglycan-negative tumors after the radical surgery. Multivariate analysis revealed that biglycan expression is an independent prognostic indicator for survival of patients with gastric cancer. The data from the current study demonstrate that elevated expression of biglycan may play an important role in the development and progression of gastric cancer, and could be further evaluated as a biomarker for predication of a poor clinical outcome.

Identification and validation of Kallikrein-ralated peptidase 11 as a novel prognostic marker of gastric cancer based on immunohistochemistry.

BACKGROUND AND OBJECTIVES: It is important to identify and validate the differentially expressed genes in gastric cancer to screen diagnostic and/or prognostic tumor markers. METHODS: cDNA expression microarray, gene set enrichment analysis, and bioinformatics approaches were used to screen the differentially expressed genes between gastric cancer tissues and adjacent non-cancerous mucosa. A novel candidate prognostic marker, Kallikrein-related peptidase 11 (KLK11), was validated in 400 Chinese gastric cancer patients. KLK11 expression in gastric cancer tissues was detected using real-time PCR and Western blot. KLK11 protein expression was further analyzed by immunostaining on tissue microarray, followed with clinicopathological significance and survival analysis. RESULTS: KLK11 expression was significantly decreased in gastric cancer compared with that in normal gastric mucosa (P<0.001). Furthermore, KLK11 expression was much lower in poorly differentiated cancer samples than that in well-differentiated group (P<0.01). Survival analysis showed that negative KLK11 expression was associated with nearly fivefold increased risk of distant metastasis after curative gastrectomy (HR 4.65, P<0.01). Multivariate Cox regression analysis showed that KLK11 expression emerged as a significant independent prognostic factor for disease-free survival and overall survival (P<0.05). CONCLUSIONS: The results indicated that KLK11 expression was decreased in gastric cancer and might serve as a novel independent prognostic marker.

Mutation analysis of tumor suppressor gene PTEN in patients with gastric carcinomas and its impact on PI3K/AKT pathway.

The aim of this study was to clarify the participation of PTEN mutation in gastric carcinogenesis and its impact on PI3K/AKT pathway. All nine exons of PTEN were screened for mutations by direct sequencing in 144 patients with pathologically proven gastric carcinoma and their corresponding normal mucosae, followed by Western blotting to detect the changes in PI3K/AKT pathway. Direct sequencing indicated there were 27 cases with mutations among 144 patients consisting of 15 cases (55.6%) of missense mutation, nine nonsense mutations (33.3%), two 1-bp deletion (7.4%), and a mutation within intron 6 (3.7%). The mutation hot spots at codons 36, 75, 232 and 393 had not been observed previously, and the mutation sites in exons 3, 5, 6 and 8 were not found, suggesting that there might be some unique characteristic of PTEN inactivation mechanism in the Shanghai population. The PTEN mutation rate was significantly higher at pTMN stages III and IV than that at stages I and II (P<0.005), and it was higher in poorly differentiated gastric cancer than in well or moderately differentiated types (P<0.05). PTEN and E-cadherin protein expression in gastric cancer was significantly down-regulated comparing with that in paracancerous tissues, while the PI3K, AKT, MMP-2, MMP-9 and NF-kappaBp65 protein were overexpressed in cancer tissues. Our results implicated that the mutations of PTEN did not occur at a significant rate in gastric carcinoma in Shanghai, but might play a role in tumorigenesis. The mutation status of PTEN was significantly relevant to pTNM staging and degree of cell differentiation, hinting that PTEN might be a prognostic biomarker of gastric cancer. The decreased expression of PTEN and E-cadherin, together with the overexpression of PI3K, AKT, MMP-2, MMP-9 and NF-kappaBp65, contributed cooperatively to the accelerated progress of gastric cancer.