Proceedings of the National Academy of Sciences of the United States of America, Oct 19, 2016
Nasopharyngeal carcinoma (NPC) is an epithelial malignancy with a unique geographical distributio... more Nasopharyngeal carcinoma (NPC) is an epithelial malignancy with a unique geographical distribution. The genomic abnormalities leading to NPC pathogenesis remain unclear. In total, 135 NPC tumors were examined to characterize the mutational landscape using whole-exome sequencing and targeted resequencing. An APOBEC cytidine deaminase mutagenesis signature was revealed in the somatic mutations. Noticeably, multiple loss-of-function mutations were identified in several NF-κB signaling negative regulators NFKBIA, CYLD, and TNFAIP3 Functional studies confirmed that inhibition of NFKBIA had a significant impact on NF-κB activity and NPC cell growth. The identified loss-of-function mutations in NFKBIA leading to protein truncation contributed to the altered NF-κB activity, which is critical for NPC tumorigenesis. In addition, somatic mutations were found in several cancer-relevant pathways, including cell cycle-phase transition, cell death, EBV infection, and viral carcinogenesis. These da...
Background: Patient-derived xenograft has been a gold standard for cancer modeling. However, low ... more Background: Patient-derived xenograft has been a gold standard for cancer modeling. However, low establishment efficiency and high maintenance cost have hindered the development in the field. In recent years, patient-derived tumor organoid culture has been developed as an efficient and economic model to mimic and recapitulate the original tumor tissue, in contrast to conventional cancer cell lines and patient-derived xenografts (Drost & Clevers, 2018). Due to the limited availability of current esophageal squamous cell carcinoma (ESCC) models, we aimed to establish a panel of ESCC patient-derived organoid (PDO) long-term cultures for ESCC study. Results: In the current project, we have established and biobanked a panel of ESCC PDO cultures in vitro from Chinese ESCC treatment-naïve patients undergoing an endoscopic examination or upfront surgery, or patients undergoing neoadjuvant chemoradiotherapy (CRT) followed by surgery in Hong Kong. We also established and maintained PDO-derive...
Esophageal squamous cell carcinoma (ESCC) is highly prevalent in Asia with a poor prognosis and a... more Esophageal squamous cell carcinoma (ESCC) is highly prevalent in Asia with a poor prognosis and a high mortality rate [1, 2]. The p63 protein, encoded by TP63, is a master regulator involved in many cell events including cell cycle, DNA damage, cell proliferation, stem cell maintenance, and cell death in different cancer types. ΔNp63α is the dominantly expressed isoform of p63 in squamous cell carcinomas, playing a critical role in tumorigenesis [3, 4]. However, the functional roles of ΔNp63α in ESCC have not been fully elucidated. Our results have revealed that ΔNp63α is highly expressed and up-regulated in ESCC. We have shown that ΔNp63α protein expression plays an oncogenic role in ESCC cells, depletion of which inhibits in vitro cell proliferation and colony formation and greatly suppresses in vivo tumor growth, in a panel of ESCC cell lines and our latest patient-derived organoid cultures, potentially in a differentiation-dependent manner. Glycolysis pathway and two novel downs...
Under stringent hybridization conditions, cDNA of segment 9 of the rotavirus genome, which codes ... more Under stringent hybridization conditions, cDNA of segment 9 of the rotavirus genome, which codes for the viral protein VP7, permitted differentiation of serotypes of culture-grown rotaviruses and natural isolates of human rotaviruses directly from clinical specimens. This was evident for the following reasons. (i) The cDNA of one serotype selectively hybridized with the RNA of the same serotype of culture-grown rotaviruses. (ii) Natural isolates of the virus thus identified as serotype 2 were also those which gave the short electrophoretic pattern characteristic of the genome of serotype 2, subgroup 1 viruses. Isolates having the long electrophoretic pattern characteristic of the genome of subgroup 2 viruses were identified as serotype 1, 3, or 4 by this method. (iii) For patients who had previously undergone serological analysis, the serotypes being excreted were the same serotypes against which there was the most marked serum neutralizing antibody response. Although the virus popu...
19 Rapid Measurement of Biodegradable Substances in Water Using Novel Microbial Sensors Reinhard ... more 19 Rapid Measurement of Biodegradable Substances in Water Using Novel Microbial Sensors Reinhard Renneberg, Alex WK Kwong, Chiyui Chan, Gotthard Kunze, Maria L. Lung, and Klaus Riedel 19.1. INTRODUCTION Microbial sensors based on microorganisms in direct ...
The key genes involved in the development of esophageal squamous cell carcinoma (ESCC) remain to ... more The key genes involved in the development of esophageal squamous cell carcinoma (ESCC) remain to be elucidated. Previous studies indicate extensive genomic alterations occur on chromosome 9 in ESCC. Using a monochromosome transfer approach, this study provides functional evidence and narrows down the critical region (CR) responsible for chromosome 9 tumor suppressing activity to a 2.4 Mb region mapping to 9q33–q34 between markers D9S1798 and D9S61. Interestingly, a high prevalence of allelic loss in this CR is also observed in primary ESCC tumors by microsatellite typing. Allelic loss is found in 30/34 (88%) tumors and the loss of heterozygosity (LOH) frequency ranges from 67 to 86%. Absent to low expression of a 9q32 candidate tumor suppressor gene (TSG), DEC1 (deleted in esophageal cancer 1), is detected in four Asian ESCC cell lines. Stably expressing DEC1 transfectants provide functional evidence for inhibition of tumor growth in nude mice and DEC1 expression is decreased in tum...
In many cancers, including nasopharyngeal carcinoma (NPC), extensive and multiple regions of alle... more In many cancers, including nasopharyngeal carcinoma (NPC), extensive and multiple regions of allelic loss occur on chromosome 14. However, to date no functionally conclusive tumor suppressor genes have yet been identified on this chromosome. Through use of the monochromosome transfer technique, this study provides functional evidence for the importance of two discrete regions of chromosome 14. A newly established A9 mouse donor cell line containing an intact copy of chromosome 14 was used for transfer of this intact chromosome into the NPC HONE1 cell line. Twelve independently established microcell hybrids demonstrated uniform loss of specific chromosome 14 loci from both endogenous and exogenous alleles. By microsatellite typing and fluorescence in situ hybridization with BAC probes, the two critical regions were localized to 14q11.2–13.1 and 14q32.1. Selective elimination of these regions during hybrid selection was strongly associated with both hybrid survival and tumor growth in...
Orthotopic xenograft model recapitulates the faithful organ-specific microenvironment and facilit... more Orthotopic xenograft model recapitulates the faithful organ-specific microenvironment and facilitates analyses involving tumor-stromal interactions that are crucial for developing new-generation cancer therapy. Herein, we describe the detailed rationales and protocols of a versatile orthotopic xenograft model for esophageal squamous cell carcinoma.
Nasopharyngeal carcinoma is an Epstein-Barr Virus (EBV) associated malignancy which is highly pre... more Nasopharyngeal carcinoma is an Epstein-Barr Virus (EBV) associated malignancy which is highly prevalent in Southeast Asia. EBV-related antibodies have been widely used as screening markers for early nasopharyngeal carcinoma (NPC) detection. However, due to low positive predictive rate, it is essential to develop new biomarkers to facilitate NPC early diagnosis or triage EBV serological high-risk individuals to improve the chance of NPC early detection. BART microRNAs, which are encoded by BamHI region of EBV, were reported to be abundant in NPC and have potential value in early diagnosis of NPC. Here, we quantified the circulating level of 17 BART microRNAs in discovery stage based on previous microarray and sequencing data and, in particular, BART 2-5p, the sole candidate whose AUC was higher than 0.8, has been chosen for further study. In validation stage, the sensitivity, specificity and AUC of BART 2-5p was 93.9%, 89.8%, 0.972(95%CI: 0.954-0.989) respectively in cohort 1 constit...
Proceedings of the National Academy of Sciences of the United States of America, Oct 19, 2016
Nasopharyngeal carcinoma (NPC) is an epithelial malignancy with a unique geographical distributio... more Nasopharyngeal carcinoma (NPC) is an epithelial malignancy with a unique geographical distribution. The genomic abnormalities leading to NPC pathogenesis remain unclear. In total, 135 NPC tumors were examined to characterize the mutational landscape using whole-exome sequencing and targeted resequencing. An APOBEC cytidine deaminase mutagenesis signature was revealed in the somatic mutations. Noticeably, multiple loss-of-function mutations were identified in several NF-κB signaling negative regulators NFKBIA, CYLD, and TNFAIP3 Functional studies confirmed that inhibition of NFKBIA had a significant impact on NF-κB activity and NPC cell growth. The identified loss-of-function mutations in NFKBIA leading to protein truncation contributed to the altered NF-κB activity, which is critical for NPC tumorigenesis. In addition, somatic mutations were found in several cancer-relevant pathways, including cell cycle-phase transition, cell death, EBV infection, and viral carcinogenesis. These da...
Background: Patient-derived xenograft has been a gold standard for cancer modeling. However, low ... more Background: Patient-derived xenograft has been a gold standard for cancer modeling. However, low establishment efficiency and high maintenance cost have hindered the development in the field. In recent years, patient-derived tumor organoid culture has been developed as an efficient and economic model to mimic and recapitulate the original tumor tissue, in contrast to conventional cancer cell lines and patient-derived xenografts (Drost & Clevers, 2018). Due to the limited availability of current esophageal squamous cell carcinoma (ESCC) models, we aimed to establish a panel of ESCC patient-derived organoid (PDO) long-term cultures for ESCC study. Results: In the current project, we have established and biobanked a panel of ESCC PDO cultures in vitro from Chinese ESCC treatment-naïve patients undergoing an endoscopic examination or upfront surgery, or patients undergoing neoadjuvant chemoradiotherapy (CRT) followed by surgery in Hong Kong. We also established and maintained PDO-derive...
Esophageal squamous cell carcinoma (ESCC) is highly prevalent in Asia with a poor prognosis and a... more Esophageal squamous cell carcinoma (ESCC) is highly prevalent in Asia with a poor prognosis and a high mortality rate [1, 2]. The p63 protein, encoded by TP63, is a master regulator involved in many cell events including cell cycle, DNA damage, cell proliferation, stem cell maintenance, and cell death in different cancer types. ΔNp63α is the dominantly expressed isoform of p63 in squamous cell carcinomas, playing a critical role in tumorigenesis [3, 4]. However, the functional roles of ΔNp63α in ESCC have not been fully elucidated. Our results have revealed that ΔNp63α is highly expressed and up-regulated in ESCC. We have shown that ΔNp63α protein expression plays an oncogenic role in ESCC cells, depletion of which inhibits in vitro cell proliferation and colony formation and greatly suppresses in vivo tumor growth, in a panel of ESCC cell lines and our latest patient-derived organoid cultures, potentially in a differentiation-dependent manner. Glycolysis pathway and two novel downs...
Under stringent hybridization conditions, cDNA of segment 9 of the rotavirus genome, which codes ... more Under stringent hybridization conditions, cDNA of segment 9 of the rotavirus genome, which codes for the viral protein VP7, permitted differentiation of serotypes of culture-grown rotaviruses and natural isolates of human rotaviruses directly from clinical specimens. This was evident for the following reasons. (i) The cDNA of one serotype selectively hybridized with the RNA of the same serotype of culture-grown rotaviruses. (ii) Natural isolates of the virus thus identified as serotype 2 were also those which gave the short electrophoretic pattern characteristic of the genome of serotype 2, subgroup 1 viruses. Isolates having the long electrophoretic pattern characteristic of the genome of subgroup 2 viruses were identified as serotype 1, 3, or 4 by this method. (iii) For patients who had previously undergone serological analysis, the serotypes being excreted were the same serotypes against which there was the most marked serum neutralizing antibody response. Although the virus popu...
19 Rapid Measurement of Biodegradable Substances in Water Using Novel Microbial Sensors Reinhard ... more 19 Rapid Measurement of Biodegradable Substances in Water Using Novel Microbial Sensors Reinhard Renneberg, Alex WK Kwong, Chiyui Chan, Gotthard Kunze, Maria L. Lung, and Klaus Riedel 19.1. INTRODUCTION Microbial sensors based on microorganisms in direct ...
The key genes involved in the development of esophageal squamous cell carcinoma (ESCC) remain to ... more The key genes involved in the development of esophageal squamous cell carcinoma (ESCC) remain to be elucidated. Previous studies indicate extensive genomic alterations occur on chromosome 9 in ESCC. Using a monochromosome transfer approach, this study provides functional evidence and narrows down the critical region (CR) responsible for chromosome 9 tumor suppressing activity to a 2.4 Mb region mapping to 9q33–q34 between markers D9S1798 and D9S61. Interestingly, a high prevalence of allelic loss in this CR is also observed in primary ESCC tumors by microsatellite typing. Allelic loss is found in 30/34 (88%) tumors and the loss of heterozygosity (LOH) frequency ranges from 67 to 86%. Absent to low expression of a 9q32 candidate tumor suppressor gene (TSG), DEC1 (deleted in esophageal cancer 1), is detected in four Asian ESCC cell lines. Stably expressing DEC1 transfectants provide functional evidence for inhibition of tumor growth in nude mice and DEC1 expression is decreased in tum...
In many cancers, including nasopharyngeal carcinoma (NPC), extensive and multiple regions of alle... more In many cancers, including nasopharyngeal carcinoma (NPC), extensive and multiple regions of allelic loss occur on chromosome 14. However, to date no functionally conclusive tumor suppressor genes have yet been identified on this chromosome. Through use of the monochromosome transfer technique, this study provides functional evidence for the importance of two discrete regions of chromosome 14. A newly established A9 mouse donor cell line containing an intact copy of chromosome 14 was used for transfer of this intact chromosome into the NPC HONE1 cell line. Twelve independently established microcell hybrids demonstrated uniform loss of specific chromosome 14 loci from both endogenous and exogenous alleles. By microsatellite typing and fluorescence in situ hybridization with BAC probes, the two critical regions were localized to 14q11.2–13.1 and 14q32.1. Selective elimination of these regions during hybrid selection was strongly associated with both hybrid survival and tumor growth in...
Orthotopic xenograft model recapitulates the faithful organ-specific microenvironment and facilit... more Orthotopic xenograft model recapitulates the faithful organ-specific microenvironment and facilitates analyses involving tumor-stromal interactions that are crucial for developing new-generation cancer therapy. Herein, we describe the detailed rationales and protocols of a versatile orthotopic xenograft model for esophageal squamous cell carcinoma.
Nasopharyngeal carcinoma is an Epstein-Barr Virus (EBV) associated malignancy which is highly pre... more Nasopharyngeal carcinoma is an Epstein-Barr Virus (EBV) associated malignancy which is highly prevalent in Southeast Asia. EBV-related antibodies have been widely used as screening markers for early nasopharyngeal carcinoma (NPC) detection. However, due to low positive predictive rate, it is essential to develop new biomarkers to facilitate NPC early diagnosis or triage EBV serological high-risk individuals to improve the chance of NPC early detection. BART microRNAs, which are encoded by BamHI region of EBV, were reported to be abundant in NPC and have potential value in early diagnosis of NPC. Here, we quantified the circulating level of 17 BART microRNAs in discovery stage based on previous microarray and sequencing data and, in particular, BART 2-5p, the sole candidate whose AUC was higher than 0.8, has been chosen for further study. In validation stage, the sensitivity, specificity and AUC of BART 2-5p was 93.9%, 89.8%, 0.972(95%CI: 0.954-0.989) respectively in cohort 1 constit...
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