Liyan Xue

Outcomes from a prospective trial of endoscopic radiofrequency ablation of early squamous cell neoplasia of the esophagus

BACKGROUND Radiofrequency ablation (RFA) is safe and effective for eradicating neoplasia in Barretts esophagus. OBJECTIVE To evaluate RFA for eradicating early esophageal squamous cell neoplasia (ESCN) defined as moderate-grade squamous intraepithelial neoplasia (MGIN) and high-grade squamous intraepithelial neoplasia (HGIN) and early flat-type esophageal squamous cell carcinoma (ESCC). DESIGN Prospective cohort study. SETTING Tertiary referral center. PATIENTS Esophageal unstained lesions (USLs) were identified using Lugols chromoendoscopy. Inclusion criteria were at least 1 flat (type 0-IIb) USL 3 cm or larger, USL-bearing esophagus 12 cm or less, and a consensus diagnosis of MGIN, HGIN, or ESCC by 2 expert GI pathologists. Exclusion criteria were previous endoscopic resection or ablation, stricture, or any nonflat mucosa. INTERVENTIONS Circumferential RFA creating a continuous treatment area (TA) including all USLs. At 3-month intervals thereafter, chromoendoscopy with biopsies followed by focal RFA of USLs, if present. MAIN OUTCOME MEASUREMENTS Complete response (CR) at 12 months defined as absence of MGIN, HGIN, or ESCC in the TA, CR after 1 RFA session, neoplastic progression from baseline, and adverse events. RESULTS Twenty-nine patients (14 male, mean age 60.3 years) with MGIN (n = 18), HGIN (n = 10), or ESCC (n = 1) participated. Mean USL length was 6.2 cm (TA 8.2 cm). At 3 months after 1 RFA session, 86% of patients (25/29) had a CR. At 12 months, 97% of patients (28/29) had a CR. There was no neoplastic progression. There were 4 strictures, all dilated to resolution. LIMITATIONS Single-center study with limited number of patients. CONCLUSIONS In patients with early ESCN (MGIN, HGIN, flat-type ESCC), RFA was associated with a high rate of histological complete response (97% of patients), no neoplastic progression, and an acceptable adverse event profile.

Overexpression of human pituitary tumor transforming gene (hPTTG), is regulated by β‐catenin /TCF pathway in human esophageal squamous cell carcinoma

Overexpression of human pituitary tumor transforming gene (PTTG) is wildly detected in many tumors, including esophageal cancer. Besides overexpression of PTTG in esophageal squamous cell carcinoma (ESCC) tissues and cells, we detected accumulation of cytoplasmic β‐catenin in ESCC. In our study, a putative TCF4‐binding element (TBE) was identified in PTTG promoter region. The activity of PTTG promoter containing the TBE was activated by S37Aβ‐catenin and inhibited by dominant‐negative TCF. Furthermore, the activation by S37Aβ‐catenin was mostly abrogated among PTTG promoter region without the TBE or with a mutant one. By using biotin‐streptavidin pull‐down assay, we also found that the TBE among PTTG promoter bound to TCF‐4 protein. Moreover, levels of PTTG mRNA and protein were increased by S37Aβ‐catenin. Finally, it is noticeable that we detected a correlation between β‐catenin localization and PTTG expression in 69 primary ESCC (p<0.01). In brief, our study shows that overexpression of PTTG in ESCC is likely due to the activation of β‐catenin/WNT signaling. As a target gene of β‐catenin/TCF pathway, PTTG may play an important role in tumorigenesis of human ESCC.

Overexpression of EB1 in human esophageal squamous cell carcinoma (ESCC) may promote cellular growth by activating β -catenin/TCF pathway

Esophageal squamous cell carcinoma (ESCC) has a multifactorial etiology involving environmental and/or genetic factors. End-binding protein 1 (EB1), which was cloned as an interacting partner of the adenomatous polyposis coli (APC) tumor suppressor protein, was previously found overexpressed in ESCC. However, the precise role of EB1 in the development of this malignancy has not yet been elucidated. In this study, we analysed freshly resected ESCC specimens and demonstrated that EB1 was overexpressed in approximately 63% of tumor samples compared to matched normal tissue. We report that overexpression of EB1 in the ESCC line EC9706 significantly promotes cell growth, whereas suppression of EB1 protein level by RNA interference significantly inhibited growth of esophageal tumor cells. In addition, EB1 overexpression induced nuclear accumulation of β-catenin and promoted the transcriptional activity of β-catenin/T-cell factor (TCF). These effects were partially or completely abolished by coexpression of APC or ΔN TCF4, respectively. Also, we found that EB1 affected the interaction between β-catenin and APC. Furthermore, EB1 overexpression was correlated with cytoplasmic/nuclear accumulation of β-catenin in primary human ESCC. Taken together, these results support the novel hypothesis that EB1 overexpression may play a role in the development of ESCC by affecting APC function and activating the β-catenin/TCF pathway.

Reduced MTA1 Expression by RNAi Inhibits in Vitro Invasion and Migration of Esophageal Squamous Cell Carcinoma Cell Line

To distinguish aggressive esophageal squamous cell carcinoma from indolent disease is the important clinical challenge. Studies have indicated that metastasis-associated gene 1(Mta1) played a role in the process of metastasis of carcinoma. The overexpression of Mta1 gene has been found in a variety of tumors. To identify the detailed roles of MTA1 protein in the carcinogenesis of esophageal squamous cell carcinoma, this study analyzed the pathological specimens on tissue microarray derived from 72 patients using immunohistochemistry. MTA1 expression increased in the nuclear with the development of esophageal squamous cell carcinoma from normal epithelial cell, dysplasia, to invasive cancer. In biological studies with human esophageal squamous cell carcinoma cell line, MTA1 plays its roles to promote cancer cell invasion, adhesion and movement. RNA interference (RNAi) against MTA1 decreased the malignant phenotypes. Gene microarray analysis revealed some metastasis-associated genes were altered by MTA1 RNAi. This study started an effective beginning to explore metastasis mechanisms and cancer gene therapy strategy targeting MTA1.

Centrosomal Nlp is an oncogenic protein that is gene-amplified in human tumors and causes spontaneous tumorigenesis in transgenic mice

Disruption of mitotic events contributes greatly to genomic instability and results in mutator phenotypes. Indeed, abnormalities of mitotic components are closely associated with malignant transformation and tumorigenesis. Here we show that ninein-like protein (Nlp), a recently identified BRCA1-associated centrosomal protein involved in microtubule nucleation and spindle formation, is an oncogenic protein. Nlp was found to be overexpressed in approximately 80% of human breast and lung carcinomas analyzed. In human lung cancers, this deregulated expression was associated with NLP gene amplification. Further analysis revealed that Nlp exhibited strong oncogenic properties; for example, it conferred to NIH3T3 rodent fibroblasts the capacity for anchorage-independent growth in vitro and tumor formation in nude mice. Consistent with these data, transgenic mice overexpressing Nlp displayed spontaneous tumorigenesis in the breast, ovary, and testicle within 60 weeks. In addition, Nlp overexpression induced more rapid onset of radiation-induced lymphoma. Furthermore, mouse embryonic fibroblasts (MEFs) derived from Nlp transgenic mice showed centrosome amplification, suggesting that Nlp overexpression mimics BRCA1 loss. These findings demonstrate that Nlp abnormalities may contribute to genomic instability and tumorigenesis and suggest that Nlp might serve as a potential biomarker for clinical diagnosis and therapeutic target.

Aurora-A interacts with Cyclin B1 and enhances its stability

The mitotic regulator Aurora-A is an oncogenic protein that is over-expressed in many types of human tumors. However, the underlying mechanism through which Aurora-A promotes tumorigenesis remains unclear. Here, we show that overexpression of Aurora-A causes an elevation of Cyclin B1 expression. Cyclin B1 degradation is delayed in Aurora-A over-expressing cells, which depends on Aurora-A kinase activity. In contrast, Aurora-A RNAi enhances Cyclin B1 degradation. Furthermore, we found that Aurora-A interacts with Cyclin B1, and that Aurora-A overexpression reduces the interaction of Cyclin B1 with APC subunits. In human esophageal squamous cell carcinomas (ESCC), overexpression of Aurora-A was correlated with deregulated expression of Cyclin B1. Taken together, these findings suggest that overexpression of Aurora-A may stabilize Cyclin B1 through inhibiting its degradation. These results provide new insight into the mechanism of how deregulated Aurora-A contributes to genomic instability and carcinogenesis.

FRAT1 overexpression leads to aberrant activation of β-catenin/TCF pathway in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor with a poor prognosis. Although aberrant activation of β‐catenin/T‐cell factor (TCF) pathway has been observed in ESCC, mechanisms underlying this phenomenon remain unknown. Frequently rearranged in advanced T‐cell lymphomas‐1 (FRAT1), overexpressed in some ESCC lines, is a positive regulator of β‐catenin/TCF pathway. However, little is known about the molecular relationship between FRAT1 and β‐catenin/TCF in ESCC. In this study, we analyzed freshly resected ESCC specimens and demonstrated that FRAT1 was overexpressed in approximately 74% of tumor samples compared with matched normal tissue. Overexpression of FRAT1 significantly promoted esophageal cancer cells growth, whereas suppression of FRAT1 level by RNAi markedly inhibited their growth. In addition, FRAT1 overexpression induced the nuclear accumulation of β‐catenin and promoted the transcriptional activity of β‐catenin/TCF. These effects were reversed by coexpression of GSK 3β or ΔN TCF4. Furthermore, accumulation of β‐catenin was correlated with FRAT1 overexpression in ESCC and the basal layer of normal esophageal epithelium. Finally, continued expression of c‐Myc is necessary and sufficient for maintenance of the growth state in cells expressing FRAT1. Taken together, these results support the novel hypothesis that aberrant activation of β‐catenin/TCF pathway in esophageal cancer appears to be due to upstream events such as FRAT1 overexpression, and c‐Myc may be an important element in oncogenesis of human ESCC induced by FRAT1.

Superficial primary small cell carcinoma of the esophagus: clinicopathological and immunohistochemical analysis of 15 cases

Primary esophageal small cell carcinoma (PESCC) is a relatively rare and aggressive tumor with poor prognosis. Systemic spreading and metastasis often occur at diagnosis. Although 5-year survival rate of superficial squamous cell carcinoma of the esophagus can be 86.1%, 5-year survival rate of superficial PESCC is still relatively low. This study mainly retrospectively analyzed clinicopathological and immunohistochemical features of 15 cases of superficial PESCC in our hospital from 1990 to 2004, in order to find suitable diagnostic markers and applicable therapies for this disease. The records mainly included presenting symptoms, demographics, diagnostic method, histopathology, follow-up, and therapy. Immunohistochemical staining of chromogranin A (CgA), neuron-specific enolase (NSE), synaptophysin (Syn), neuronal cell adhesion molecules (CD56), thyroid transcription factor-1 (TTF-1), cytokeration 34betaE12 (CK34betaE12), cytokeratin (AE1/AE3), and cytokeratin 10/13 was performed. Incidence of superficial PESCC accounted for 4.8% of that of superficial carcinoma of the esophagus during the same period. Initial symptoms of all patients were dysphagia or accompanied with retrosternal pain and upper abdominal pain, and duration of these symptoms was 75 days averagely. Mean age of patients was 58.8 years old, and the male-to-female ratio was 2.75 : 1. Lesions were mainly located at middle thoracic esophagus. One, 2, and 5-year survival rates were 66.7, 33.3, and 6.7%, respectively. The median survival time was 19 months and mean survival time was 23.7 months after diagnosis. The percentages of PESCC samples with positive immunoreactivity were NSE 100%, Syn 100%, AE1/AE3 100%, CD56 93.3%, TTF-1 60%, CgA 53.3%, CK34betaE12 6.7%, and cytokeratin 10/13 0%, respectively. Our study suggested that PESCC was a rare and aggressive tumor with high malignancy. Superficial PESCC had rapid progression and poor prognosis compared with superficial squamous cell carcinoma of the esophagus at the same stage. The systemic therapy based on combination of postoperative chemotherapy and radiotherapy might be an effective approach for the treatment of superficial PESCC as a systemic disease. Higher proportion of positive labeling of NSE, Syn, AE1/AE3, CD56, TTF-1, and CgA in PESCC was valuably applied in diagnosis and differential diagnosis.

Endoscopic radiofrequency ablation for early esophageal squamous cell neoplasia: report of safety and effectiveness from a large prospective trial

BACKGROUND AND STUDY AIMS Endoscopic radiofrequency ablation (RFA) is an established therapy for Barretts esophagus. Preliminary reports, limited by low patient numbers, also suggest a possible role for RFA in early esophageal squamous cell neoplasia (ESCN). The aim of this study was to evaluate the safety and effectiveness of RFA for early ESCN (moderate/high grade intraepithelial neoplasia [MGIN/HGIN] and early flat-type esophageal squamous cell carcinoma [ESCC]). PATIENTS AND METHODS This prospective cohort study included patients with at least one flat (type 0-IIb) unstained lesion (USL) on Lugols chromoendoscopy and a consensus diagnosis of MGIN, HGIN, or early ESCC. RFA was used at baseline to treat all USLs, and then biopsy (and focal RFA if USL persisted) was performed every 3 months until all biopsies were negative for MGIN, HGIN, and ESCC. The main outcome measurements were complete response at 3 and 12 months (absence of MGIN, HGIN, and ESCC), neoplastic progression, and adverse events. RESULTS A total of 96 patients participated (MGIN 45, HGIN 42, early ESCC 9). At 3 and 12 months, 73 % (70/96) and 84 % (81/96), respectively, showed a complete response. Two patients (2 %) progressed (MGIN to HGIN; HGIN to T1m2 ESCC); both were treated endoscopically and achieved complete response. Stricture occurred in 20 patients (21 %), all after circumferential RFA. Lugols + RFA 12 J/cm(2) (single application, no cleaning) was the favored baseline circumferential RFA technique (82 % 12-month complete response [14/17], 6 % stricture [6/17]). CONCLUSION In patients with early ESCN, RFA was associated with a high complete response rate and an acceptable safety profile.

Low-Cost High-Resolution Microendoscopy for the Detection of Esophageal Squamous Cell Neoplasia: An International Trial

BACKGROUND & AIMS Esophageal squamous cell neoplasia has a high mortality rate as a result of late detection. In high-risk regions such as China, screening is performed by Lugols chromoendoscopy (LCE). LCE has low specificity, resulting in unnecessary tissue biopsy with a subsequent increase in procedure cost and risk. The purpose of this study was to evaluate the accuracy of a novel, low-cost, high-resolution microendoscope (HRME) as an adjunct to LCE. METHODS In this prospective trial, 147 consecutive high-risk patients were enrolled from 2 US and 2 Chinese tertiary centers. Three expert and 4 novice endoscopists performed white-light endoscopy followed by LCE and HRME. All optical images were compared with the gold standard of histopathology. RESULTS By using a per-biopsy analysis, the sensitivity of LCE vs LCE + HRME was 96% vs 91% (P = .0832), specificity was 48% vs 88% (P < .001), positive predictive value was 22% vs 45% (P < .0001), negative predictive value was 98% vs 98% (P = .3551), and overall accuracy was 57% vs 90% (P < .001), respectively. By using a per-patient analysis, the sensitivity of LCE vs LCE + HRME was 100% vs 95% (P = .16), specificity was 29% vs 79% (P < .001), positive predictive value was 32% vs 60%, 100% vs 98%, and accuracy was 47% vs 83% (P < .001). With the use of HRME, 136 biopsies (60%; 95% confidence interval, 53%-66%) could have been spared, and 55 patients (48%; 95% confidence interval, 38%-57%) could have been spared any biopsy. CONCLUSIONS In this trial, HRME improved the accuracy of LCE for esophageal squamous cell neoplasia screening and surveillance. HRME may be a cost-effective optical biopsy adjunct to LCE, potentially reducing unnecessary biopsies and facilitating real-time decision making in globally underserved regions. ClinicalTrials.gov, NCT 01384708.