Xiaoya Guan

Expression of SATB1 Promotes the Growth and Metastasis of Colorectal Cancer

Special AT-rich sequence-binding protein-1 (SATB1) has been identified as a genome organizer that reprograms chromatin organization and transcription profiles. SATB1 promotes tumor growth and metastasis in breast cancer and is associated with poor prognosis in several cancer types. The association between SATB1 and colorectal cancer (CRC) has not been studied intensively. Therefore, this study aimed to investigate the effect of SATB1 on CRC growth and metastasis in vitro and in vivo and its correlation with overall survival and clinicopathological factors in CRC patients. Stable SATB1 knockdown and SATB1-overexpressing cell lines were established. SATB1 knockdown decreased cell growth, colony formation, migration, and invasion and increased apoptosis in CRC cells in vitro (p<0.05), whereas SATB1 overexpression had the opposite effect. SATB1 overexpression increased tumor growth and metastasis to lung and liver in vivo by using xenograft animal models (p<0.05). Thus, SATB1 promoted an aggressive CRC phenotype in vitro and in vivo. Immunohistochemical analysis of 560 CRC specimens showed that SATB1 expression was significantly higher in CRC tissues than in matched non-tumor mucosa (p<0.001). In addition, SATB1 expression was significantly higher in patients with poorly differentiated tumors, higher invasion depth, distant metastasis, and advanced TNM stage. SATB1-positive patients had a poorer prognosis than SATB1-negative patients, and SATB1 was identified as an independent prognostic factor for CRC (p = 0.009). Strikingly, we also evaluated SATB2 expression in CRC and found that SATB2 was more abundantly expressed in non-cancerous mucosa compared to colorectal cancer tissues (p<0.001). However, SATB2 expression had no influence on prognosis of CRC patients (p = 0.836). SATB1 expression was significantly associated with shorter survival time either in SATB2-positive patients or in SATB2-negative patients (p<0.001). In conclusion, our findings indicated an important role for SATB1 in CRC tumorigenesis and metastasis. Therefore, SATB1 may represent an important prognostic biomarker and therapeutic target for CRC.

SKP2 High Expression, KIT Exon 11 Deletions, and Gastrointestinal Bleeding as Predictors of Poor Prognosis in Primary Gastrointestinal Stromal Tumors

Background and Aims Considering the indication of adjuvant therapy, the recurrence risk for primary gastrointestinal stromal tumor (GIST) after surgery needs to be accurately estimated. However, current risk stratification schemes may still have room for improvement. This study seeks to analyze prognostic factors for primary GISTs from 3 aspects, including clinicopathological parameters, immunohistochemical biomarkers, and gene mutational status, and attempts to find novel valuable factors predicting the malignancy potential of GISTs. Methods Retrospective data from 114 primary GIST patients after R0 resection were collected. Clinicopathological data was obtained from medical records and re-evaluated. Immunohistochemical analysis was performed using the Tissue Microarray method for Ki67, p16, p27, p53, SKP2, CD133, and actin. KIT gene exons 9, 11, 13, and 17 and PDGFRα gene exons 12 and 18 were tested for mutations using PCR. Results Univariate analysis revealed the following factors as poor prognostic indicators for relapse-free survival with a median follow-up of 50 months: male gender, gastrointestinal bleeding, mitotic index >5/50HPFs, tumor size >5 cm, non-gastric site, necrosis, epithelioid or mixed cell type, surrounding tissue invasion, Ki67>5%, p16>20%, p53 index >10, SKP2>10%, and KIT exon 11 deletion. Besides mitotic index, tumor size and site, SKP2 high expression (RR = 2.91, 95% CI: 1.41–5.99, P = 0.004) and KIT exon 11 deletion (RR = 2.73, 95% CI: 1.04–7.16, P = 0.041) were also independent risk factors in multivariate analysis, with gastrointestinal bleeding also showing a trend towards significance (RR = 1.88, 95% CI: 0.98–3.64, P = 0.059). In addition, gastrointestinal bleeding and SKP2 high expression showed a good ability to stratify high-risk patients further. Conclusion Our results show that gastrointestinal bleeding, SKP2 high expression, and KIT exon 11 deletions may be useful indicators of high recurrence risk for primary GIST patients.

PTK7 overexpression in colorectal tumors: Clinicopathological correlation and prognosis relevance

Colorectal cancer (CRC) has one of the highest mortality rates in the worldwide and its incidence has been increasing in recent years. Protein tyrosine kinase-7 (PTK7) is an inactive member of receptor protein tyrosine kinase (RPTK)-like molecules, which is involved in tumorigenesis of a variety of cancers. Our study aimed to investigate expression of PTK7 in colorectal tumors (including benign adenomas and malignant carcinomas), and its potential function in tumorigenesis and prognosis. A total of 209 CRC patients and 28 colonic adenoma patients were included in this study. Reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR were performed in 14 pairs of fresh frozen tissues to evaluate mRNA expression of PTK7. Expression of PTK7 protein in 209 CRC tissues with paired non-cancerous mucosa and 28 adenoma specimens were tested using immunohistochemistry. The expression difference and its correlation with clinicopathological features and overall survival were assessed by SPSS statistics (version 22). P<0.05 was considered significant. RT-PCR and quantitative real-time PCR showed a higher expression of PTK7 mRNA in CRC compared with non-tumorous mucosa (4.87±3.71 vs. 1.33±1.05; P<0.001). PTK7 expression was significantly higher in adenoma (75%) and CRC (68.3%) than in non-tumorous mucosa (P<0.001). PTK7 expression was correlated with tumor differentiation (P=0.027), lymph node metastasis (P=0.005), distant metastasis (P=0.001) and TNM stage (P=0.028) of CRC patients. Significant correlation between PTK7 overexpression and favorable overall survival of CRC patients was observed (P=0.005). Therefore, it may act as a candidate biomarker to predict the occurrence and prognosis of colorectal tumor.

Superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic adenocarcinoma

The aim of this study is trying to describe more details of superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic ductal adenocarcinoma, to evaluate biological and prognostic implications of tumor budding in this margin, and to provide more evidence for evaluation of R0 surgery in pancreaticoduodenectomy. 46 patients in 5-years period are included in this study. Immunochemistry and immunofluorescence are used to analyze tumor budding and epithelial–mesenchymal transition. Superior mesenteric artery margin might be described from four aspects including location, gross appearance, microscopic appearance and tumor budding. We find that 1mm rule for R1 surgery is more appropriate to predict prognosis (P = 0.009) than 0mm rule (P = 0.141). Expression of cytokeratin in tumor budding is significantly lower than primary tumor (P = 0.001), and it suggests that tumor budding may participate the procedure of epithelial–mesenchymal transition. High-grade tumor budding and decreasing cytokeratin of tumor budding correlate with distant metastasis and has negative influence on prognosis. So superior mesenteric artery margin might be not only an area that tumor cells may invade, but also a pathway for distant metastasis. It is necessary to evaluate superior mesenteric artery margin in pancreaticoduodenectomy for pancreatic cancer.

Suppression of CD26 inhibits growth and metastasis of pancreatic cancer

CD26/DPPIV is a glycosylated transmembrane type II protein and has a multitude of biological functions, while its impact on the malignant phenotypes of cancer cells has not been fully understood. This study aimed to investigate the effect of CD26 on growth and metastasis of pancreatic cancer cells in vitro and in vivo. We found in this study that CD26 expression was higher in cell lines that derived from the metastatic sites than those from the primary tumor sites. In specimens of pancreatic cancer patients, CD26 expression was higher in cancerous tissues than in paired normal tissues. In in vitro experiments, knockdown of CD26 expression inhibited cell growth, migration, invasion, colony formation, and increased cell apoptosis of pancreatic cancer cells. Knockdown of CD26 also decreased tumor growth and liver metastasis in vivo by using xenograft animal models. Suppression of CD26 could inhibit expression of epithelial-mesenchymal transition (EMT) regulatory genes. Our results indicated that CD26 may represent a new therapeutic target for pancreatic cancer.

Elevated serum CD26 level is associated with metastasis and post-operation survival in pancreatic cancer patients

Background: It has been proved that soluble CD26 (sCD26) has a close relationship with several types of cancers, while its level in pancreatic cancer has not been well established. Methods: In this study, enzyme-linked immunosorbent assay (ELISA) was applied to test the serum concentration of sCD26 in a total of 148 patients with different pancreatic diseases, including 92 pancreatic ductal adenocarcinoma (PDAC) patients. The correlation between sCD26 level and the clinicopathological features as well as post-operation survival of PDAC patients was also analyzed. Results: In this cohort, the average sCD26 concentration in healthy donors was 361.30±154.64 µg/L, while it varied in different types of pancreatic diseases. The preoperative sCD26 concentration of PDAC patients was 426.36±207.62 µg/L, which was higher than that in healthy donors (P=0.048) and closely related with tumor location, size, distant metastasis, tumor stage and post-operation survival time. But after operation, the serum concentration decreased to 243.44±113.90 µg/L in PDAC patients. Conclusions: The findings of this study have unveiled the concentrations of sCD26 in pancreatic diseases, and correlations between increased sCD26 level and favorable clinicopathological features as well as post-operation survival in PDAC patients were also detected.

Fusobacterium nucleatum infection is correlated with tumor metastasis and postoperative survival of colorectal cancer patients in China

Background: In western patients, the association of Fusobacterium nucleatum ( F. nucleatum ) with colorectal carcinoma (CRC) has been established, but the underlying mechanism remains unclear. There is no report about F. nucleatum infection status and its potential role in CRC patients in China. This study aimed to evaluate infection status and infection load of F. nucleatum and its correlation with clinicopathological features and prognosis of CRC patients in China. Methods: Fresh tumor and adjacent normal mucosa tissues were obtained at surgery from 152 CRC patients, and then DNA was assayed for infection of F. nucleatum by quantitative PCR. Then the association of infection with clinicopathological features and prognosis was evaluated. In addition, MMP9, MMP11, CD45RO and FOXP3 expression levels was assessed by immunohistochemistry to explore the potential role of F. nucleatum . Results: The infection rate of F. nucleatum in CRC tissues was significantly higher than that in adjacent normal tissues (77.6% vs . 57.2%, P<0.001), and median F. nucleatum copy number was also significantly higher in CRC tissues than in adjacent normal tissues (87 vs . 37, P<0.001). F. nucleatum infection of tumor tissues was related with poorer tumor differentiation (P<0.001), deeper tumor invasion (P<0.001), lymph node metastasis (P=0.01), distant metastasis (P=0.001) and advanced TNM stage (P=0.034). Specimens with higher infection load contained fewer CD45RO + T lymphocytes and more FOXP3 + regulatory T lymphocytes than those with lower infection load. And high-copy group had a poorer postoperative survival than the low-copy group (P=0.027). In the subset of CRC patients with F. nucleatum infection, tumor stage and F. nucleatum infection were independent prognostic factors. Advanced tumor stage and high-load infection were correlated poorer prognosis (P=0.023 and 0.032, respectively). Conclusions: Infection rate and load of F. nucleatum are higher in carcinoma tissues than in adjacent normal tissues from CRC patients in Chian. F. nucleatum infection was correlated with tumor metastasis and overall postoperative survival of colorectal cancer patients, so it can help to improve prevention, diagnosis and treatment of CRC in China.

Diagnostic and prognostic value of KRAS mutations in circulating pancreatic ductal adenocarcinoma tumor DNA

Background: Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic tumor and one of the most malignant tumors worldwide. Circulating tumor DNA (ctDNA) has significant diagnostic and prognostic value for cancer patients. Methods: Surgical specimens and plasma samples were obtained from a total of 35 patients with PDAC at the Peking University Cancer Hospital between June 2016 and May 2017. To investigate KRAS mutations (G12R, G12V or G12D) in plasma ctDNA, digital polymerase chain reaction (PCR) was performed on samples obtained from PDAC patients before and after surgical resection. Results: KRAS mutations (G12R, G12V or G12D) between surgical tissue DNA (tDNA) and preoperative plasma ctDNA (pre-ctDNA) were consistent in 27 of 35 samples (77.1%, kappa index =0.397, P=0.003). Moreover, pre-ctDNA and postoperative plasma ctDNA (post-ctDNA) showed statistically significant associations with CA19-9 levels before surgery (P=0.027 and P=0.003, respectively). In addition, the Kaplan-Meier univariate and Cox multivariate analysis revealed that pre-ctDNA (G12V), post-ctDNA (G12V), or pre-post ctDNA (G12V, G12D) might be independent prognostic factors for overall survival (OS) and progression-free survival (PFS). Conclusions: Analysis of pre-ctDNA, post-ctDNA, and pre-post ctDNA showed high PDAC diagnostic and prognostic potential in patients.

LAPTM4B-35 expression was correlated with favorable postoperation survival in pancreatic cancer patients

Background: Pancreatic cancer (PC) is malignant and lethal with its invasiveness and metastasis. Till now, it’s still very difficult to diagnose PC at its early stage due to lack of obvious symptoms. Therefore, there is an urgent need to find an efficient biomarker to help diagnose PC as early as possible. Lysosome-associated protein transmembrane 4 beta-35 (LAPTM4B-35) is a kind of transmembrane oncoprotein which has been proved to be overexpressed in a variety of solid tumors. Few studies have focused on the expression of LAPTM4B-35 and its function in PC patients. This study aimed to assess LAPTM4B-35 expression in PC and to investigate the relationship between LAPTM4B-35 expression with clinicopathological features and post-operation survival of PC patients. Methods: We collected tumor tissues and paired non-cancerous tissues from 93 PC patients and evaluated LAPTM4B-35 expression through immunohistochemistry assay. And we also explored LAPTM4B-35 expression of mRNA and protein by means of reverse transcription-polymerase chain reaction (RT-PCR), real-time PCR and Western blotting in PC cell lines and frozen tumor tissues. We used chi-squared test and Fisher’s exact test to evaluate the relationship between LAPTM4B-35 expression and clinicopathological factors. Kaplan-Meier survival analysis and Cox regression were used for survival analysis. A two-sided P value less than 0.05 was considered to be statistically significant. Results: LAPTM4B-35 was found to be expressed in 60 of 93 (64.5%) tumor tissues and 7 of 93 (7.5%) paired non-cancerous tissues (P Conclusions: LAPTM4B-35 expression was correlated with favorable post-operation survival in PC patients. LAPTM4B-35 might act as a candidate biomarker for PC at its early stage.