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BACKGROUND AND AIMS Early recurrence of hepatocellular carcinoma (HCC) after surgical resection compromises patient survival. Timely detection of HCC recurrence and its clonality is required to implement salvage therapies appropriately. This study examined the feasibility of virus-host chimera DNA (vh-DNA), generated from junctions of hepatitis B virus (HBV) integration in the HCC chromosome, as a circulating biomarker for this clinical setting. APPROACH AND RESULTS HBV integration in 50 patients with HBV-related HCC was determined by the Hybridization capture-based next-generation sequencing (NGS) platform. For individual HCC, the vh-DNA was quantified by specific droplet digital PCR (ddPCR) assay in plasma samples collected before and 2 months after surgery. HBV integrations were identified in 44 out of 50 patients with HBV-related HCC. Tumor-specific ddPCR was developed to measure the corresponding vh-DNA copy number in baseline plasma from each patient immediately before surgery. vh-DNA was detected in 43 patients (97.7%), and the levels correlated with the tumor sizes (detection limit at 1.5 cm). Among the plasma collected at 2 months after surgery, 10 cases (23.3%) still contained the same signature vh-DNA detected at baseline, indicating the presence of residual tumor cells. Nine of them (90%) experienced HCC recurrence within 1 year, supporting vh-DNA as an independent risk factor in predicting early recurrence. Analysis of circulating vh-DNA at recurrence further helped identify the clonal origin. A total of 81.8% of recurrences came from original HCC clones sharing the same plasma vh-DNA, whereas 18.2% were from de novo HCC. CONCLUSIONS vh-DNA was shown to be a circulating biomarker for detecting the tumor load in majority of patients with HBV-related HCC and aided in monitoring residual tumor and recurrence clonality after tumor resection.

Shisa3 is a novel tumor suppressor identified in lung cancer. However, its antitumor activity in other human cancers and the mechanism of gene inactivation remain unknown. SHISA3 expression was measured by reverse transcription-PCR (RT-PCR) and quantitative RT-PCR (RT-qPCR). DNA methylation was determined by bisulfite sequencing and pyrosequencing. Down-regulation of SHISA3 expression was observed in all of 11 colorectal cancer (CRC) cell lines and was further confirmed in 34 (65.4 %) of 52 colorectal carcinomas by RT-qPCR. Four of six CRC cell lines could restore SHISA3 expression after treatment with 5-aza-2′-deoxycytidine. Tumor-specific methylation of five CpG sites in the first intron of SHISA3 was identified by bisulfite sequencing, and their methylation levels were quantified in 127 pairs of primary CRC tissues by bisulfite pyrosequencing. The methylation levels of SHISA3 in tumors were noticeably higher than that in their matched normal mucosae. In addition, SHISA3 hypermethylation was significantly associated with an increased risk of disease recurrence in patients with stage II and III disease (P = 0.007) and was an independent predictor of poor overall survival [hazard ratio (HR) 2.9, 95 % confidence interval (CI) 1.5–5.8; P = 0.002] and disease-free survival (HR 4.0, 95 % CI 1.6–10.2; P = 0.003) of CRC patients. SHISA3 gene is epigenetically inactivated in a substantial fraction of CRC, and its hypermethylation is of prognostic significance in predicting clinical outcome. The quantitative bisulfite pyrosequencing assay established could be a cost-effective tool for providing a potential biomarker of adverse prognosis in CRC.

4090 Background: About one-third of patients suffer tumor recurrence within the first year after surgical resection of HCC. Early recurrence compromised their overall survival. Timing detection of HCC recurrence and its clonality is required to implement therapeutic trials appropriately. This study examined the virus-host chimera DNA (vh-chimera DNA), generated from junctions of HBV integration in HCC chromosome and released into blood, as a potential circulating biomarker for this clinical setting. Methods: We established a capture-next generation sequencing (NGS) platform to identify the HBV integrations in 50 resected HBV-related HCC. For individual HCC, the major clonal HBV integration sites were chosen to design specific primers for droplet digital PCR (ddPCR) to detect and quantify the vh-chimera DNA in plasma samples, collected either just before surgery or two months after surgery. Levels of vh-chimera DNA were then correlated with baseline HCC size or recurrence in one-year follow up. Results: We succeeded in detecting HBV integrations in the HCC from 44 out of 50 HBV-related HCC patients (88%). The copy number of vh-chimera DNA in plasma at surgery from 42 patients correlated with tumor sizes, with the detection limit at 1.5-2 cm. Among the plasma collected 2 months after surgery, 26.2% of samples contained the same HCC signature vh-chimera DNA as baseline plasma, indicating a possible residual tumor. Consistently, 81.8% of them suffered HCC recurrence within one year. The signature vh-DNA in the plasma suggested the majority of recurrences coming from the original HCC clones, whereas 2 from de novo ones. Conclusions: This study supported vh-chimera DNA as a new circulation marker for detecting the existence of most HBV-related HCC. This new biomarker may complement AFP to help detect residual or recurrent HCC and their clonality after curative therapies.

// Tzu-Ming Jao 1 , Ya-Lin Li 1 , Shu-Wha Lin 1, 2 , Sheng-Tai Tzeng 1 , I-Shing Yu 3 , Sou-Jhy Yen 4 , Ming-Hong Tsai 4, 5 , Ya-Chien Yang 1, 2 1 Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan 2 Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan 3 Laboratory Animal Center, National Taiwan University College of Medicine, Taipei, Taiwan 4 Department of Surgery, Cardinal Tien Hospital, New Taipei City, Taiwan 5 School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan Correspondence to: Ming-Hong Tsai, email: tsai110008@yahoo.com.tw Ya-Chien Yang, email: ycyangntu@ntu.edu.tw Keywords: NDST4, tumor suppressor gene, heparan sulfate proteoglycan, Ndst4 knockout mouse Received: July 29, 2016 Accepted: October 14, 2016 Published: October 26, 2016 ABSTRACT Glucosaminyl N -deacetylase/ N -sulfotransferases (NDSTs) are the first enzymes that mediate the initiation of heparan sulfate sulfation. We previously identified NDST4 as a putative tumor suppressor in human colorectal cancer. In the study, we generated an Ndst4 knockout ( Ndst4 −/− ) mouse strain and explored its phenotypic characteristics, particularly in the development of colonic epithelial homeostasis. The Ndst4-deficient mice were viable and fertile, and their life spans were similar to those of wild-type littermates. No gross behavioral or morphological differences were observed between the Ndst4 −/− and wild-type mice, and no significant changes were determined in the hematological or serum biochemical parameters of the Ndst4 −/− mice. Ndst4 RNA transcripts were expressed in the brain, lung, gastrointestinal tract, pancreas, and ovary. However, Ndst4-null mice exhibited no gross or histological abnormalities in the studied organs, except for the colon. Although no alterations were observed in the crypt length or number of proliferating cells, the Ndst4 −/− mice exhibited an increased number of goblet cells and a decreased number of colonocytes in the proximal colon compared with the wild-type mice. Moreover, Ndst4 deficiency increased the basal level of apoptosis in the colonic epithelium. Taken together, we established, for the first time, an Ndst4 −/− mouse strain and revealed the involvement of Ndst4 in the development and homeostasis of colonic epithelium. Accordingly, NDST4 in human colon might direct the biosynthesis of specific heparan sulfate proteoglycans that are essential for the maintenance of colonic epithelial homeostasis. Thus, the loss of its function may result in the tumorigenesis and progression of colorectal cancer.

Colorectal cancer (CRC) is one of the most common causes of cancer deaths in the world, and most of CRC arise sporadically by the emergence of multiple chromosomal aberrations. Allelic losses in the long arm of chromosome 4 are commonly encountered in many human malignancies, but few tumor suppressor genes (TSGs) are identified. By loss of heterozygosity study at chromosome 4 in 114 colorectal carcinomas, we identified N-deacetylase/N-sulfotransferase (heparan glucosaminyl) 4 (NDST4) as a novel TSG that had been published recently. We demonstrated for the first time that the genetic loss of NDST4 was significantly associated with advanced pathological stage and poorer overall survival of patients. Meanwhile, gene expression of NDST4 was obviously decreased in 30 (57.7%) of 52 CRC tumors when compared with their matched normal mucosae. In the present study, tumor suppressor activity of NDST4 was identified by in vitro cell models and mouse xenograft tumor models. Ectopic expression of NDST4 in the human CRC cells induced a significant suppression in cell proliferation, anchorage-independent growth and invasion in vitro. Subcutaneous injection of NDST4-inducible CRC cells in nude mice showed alleviated tumor growth in doxycycline treated mice when compared with doxycycline untreated mice. More importantly, via intrasplenic implantation, re-expression of NDST4 in silenced cells restrained liver metastasis, and also improved survival in nude mice. Taken together, these results indicate that NDST4 is a tumor suppressor gene associated with CRC, and its downregulation might promote tumor progression and distant metastasis. In addition, allelic loss of NDST4 gene could serve as a molecular predictor of metastasis and poor prognosis in patients with CRC. Citation Format: Tzu-Ming Jao, Ming-Hong Tsai, Sheng-Tai Tzeng, Ya-Chien Yang. N-deacetylase/N-sulfotransferase (heparan glucosaminyl) 4, a novel tumor suppressor, suppresses tumorigenesis and liver metastasis of colorectal cancer cells in mice. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2149. doi:10.1158/1538-7445.AM2015-2149

e14532 Background: Shisa3, a newly identified tumor suppressor, inhibits tumorigenesis and metastasis via counter-regulation of β-catenin in non-small cell lung cancer. However, its tumor suppresso...

NDST4 is one member of N-deacetylase/N-sulfotransferase (heparan glucosaminyl) (NDST) family, which are responsible for heparan sulfate (HS) biosynthesis on a core protein to form heparan sulfate proteoglycans (HSPGs). The HS chains of HSPGs bind to and regulate their functions of various growth factors, cytokines and chemokines. HSPGs ubiquitously reside on cell surface, inside the cell, and in the extracellular matrix. Importantly, the content and distribution of HSPGs are altered during tumorigenesis. In the study, 30 (57.7%) of 52 primary colorectal carcinomas showed a dramatic reduction in NDST4 RNA transcripts, and genetic loss of NDST4 was significantly associated with poor survival of patients with colorectal cancer. We further generated an Ndst4-knockout mouse strain, which could develop and reproduce normally. Notably, using the dextran sodium sulfate mouse model of acute colitis, Ndst4 deficiency resulted in a significantly higher disease activity index and obviously hyperemic appearance in the cecum. In the development of colitis-associated cancer, the size of colonic tumors induced by azoxymethane/dextran sodium sulfate was significantly increased in Ndst4-deficient mice compared with wild-type mice. Taken together, loss-of-function of NDST4 might impair the modification of HS chains of specific HSPGs leading to tumor-promoting inflammation in the colon. The full spectrum of signaling pathways contributed by NDST4 to colitis and tumor progression remains to be elucidated. Citation Format: Tzu-Ming Jao, Ming-Hong Tsai, Chi-Yen Huang, Sheng-Tai Tzeng, Jing-Xing Lee, Wei-Chen Lo, Che-Wei Chang, Ya-Chien Yang. Acute colitis and colitis-associated cancer are exacerbated in mice deficient N-deacetylase/N-sulfotransferase-4. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2472. doi:10.1158/1538-7445.AM2014-2472